JP6358777B2 - Image forming method, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to an image forming method, an image forming apparatus, and a process cartridge using an electrophotographic image forming toner.

In recent years, there has been a demand for low-temperature fixing of toner in electrophotography. This is due not only to energy saving by reducing the energy required for fixing, but also to the demand for higher speed and higher image quality of the electrophotographic image forming apparatus.
In general, the image quality decreases as the speed of an electrophotographic image forming apparatus increases. There are various factors related to this, but among them, the greatest contribution is the influence of fixing defects in the fixing process.

  In the fixing process, an unfixed toner image on a recording medium typified by paper is fixed on the recording medium by heat and pressure to become a fixed image. However, when the system speed is increased, an unfixed toner image is formed in the fixing process. However, a sufficient amount of heat cannot be obtained. As a result, a fixing failure occurs in the fixing process, the surface of the final toner image becomes rough, or an afterimage phenomenon called cold offset occurs, resulting in a defective image. Therefore, when the system speed is increased, it is conceivable to raise the fixing temperature in order to prevent the image quality from being lowered. However, from the viewpoint of side effects on other processes in the image forming apparatus at a temperature leaking from the fixing device, acceleration of the consumption speed of the fixing member, and increase in energy consumption, increasing the fixing temperature is not necessarily the best countermeasure.

  Therefore, particularly in a high-speed image forming apparatus, improvement in the fixing performance of the toner itself is required. More specifically, in the fixing process, a toner having a sufficient fixing property at a lower temperature is required.

  Conventionally, various studies have been made in order to improve toner fixability. For example, in order to improve the toner fixing performance, a method of controlling the thermal characteristics of the resin itself, represented by the glass transition temperature (Tg) and the softening temperature (T1 / 2), is known. However, lowering the Tg of the resin deteriorates the heat resistant storage stability, and lowering the T1 / 2 temperature due to lowering the molecular weight of the resin causes problems such as the occurrence of hot offset. Therefore, by controlling the thermal characteristics of the resin itself, it has not been possible to obtain a toner having all of low-temperature fixability, heat-resistant storage stability, and hot offset resistance.

In order to cope with the low-temperature fixing, an attempt has been made to use a polyester resin having excellent low-temperature fixability and relatively good heat storage stability, instead of the conventionally used styrene-acrylic resin. (Patent Documents 1 to 6)
In addition, there is an attempt to add a specific non-olefinic crystalline polymer having a sharp melt property at a glass transition temperature to a binder for the purpose of improving low-temperature fixability (Patent Document 7). However, these cannot be said to have been optimized for molecular structure and molecular weight.

Patent Documents 8 and 9 disclose a technique for improving fixability by using a crystalline polyester having a sharp melt property as in the above-described specific non-olefinic crystalline polymer for a toner.
However, the toner using the crystalline polyester described in Patent Document 8 has a low acid value and a hydroxyl value of 5 or less and 20 or less, respectively, and has a low affinity for paper and the crystalline polyester. I don't have it.
Further, the toner using the crystalline polyester described in Patent Document 9 is not optimized with respect to the molecular weight of the finally obtained toner and the presence state of the crystalline polyester. Therefore, the toner using the crystalline polyester described in Patent Document 9 does not always exhibit the excellent low-temperature fixability and heat-resistant storage stability caused by the crystalline polyester after the toner is actually made into a toner. In addition, no countermeasure against hot offset is taken, and a temperature range in which a good image can be fixed is not always secured.

  Patent Document 10 proposes a technique in which an incompatible crystalline polyester resin and an amorphous polyester resin have a sea-island phase separation structure. However, the toner described in Patent Document 10 uses three types of resins including a crystalline polyester resin as a resin. If an attempt is made to maintain the sea-island structure of the crystalline polyester resin with this technique, the crystalline polyester resin is used. The dispersion diameter of the toner may become too large, which may hinder heat-resistant storage stability, or the electrical resistance may be too low, resulting in a transfer failure in the transfer process, which may cause a rough image.

  In Patent Document 11, the endothermic amount of a peak appearing on the endothermic side is defined in a DSC curve measured by a differential scanning calorimeter. Thus, a technique has been proposed in which the presence of the crystalline polyester resin is controlled, the effects of the crystalline polyester resin are significantly exhibited, and the toner is imparted with low-temperature fixability and heat-resistant storage stability. However, in Patent Document 11, it is assumed that a resin having a relatively high softening temperature is used as the non-crystalline polyester resin used in combination with the crystalline polyester resin, and the role of the low-temperature fixability is guaranteed by the crystalline polyester resin. Therefore, the amount of the crystalline polyester resin used is inevitably increased, and the risk of deterioration in heat resistant storage stability due to the compatibility with the amorphous resin is increased.

  Patent Document 12 proposes a technique in which a toner contains a large amount of crystalline polyester resin. However, since the amount of crystalline polyester resin is very large, there is a risk that heat-resistant storage stability is deteriorated due to compatibility with the amorphous resin. high.

  Patent Document 13 proposes a technique for defining the peak and half width of the toner molecular weight distribution and the amount of chloroform insoluble, and using two or more resins having different softening temperatures as the binder resin. However, since no crystalline polyester resin is used, the low-temperature fixability is insufficient as compared with the case where a crystalline polyester resin is used.

  In Patent Document 14, a toner using a crystalline polyester resin is stored in a constant temperature bath at 45 ° C. for 12 hours, and the spectral height of the crystalline polyester resin and the amorphous resin using a Fourier transform infrared spectroscopy analyzer is measured. A technique that specifies the ratio of the thickness has been proposed. However, since the molecular weight of the resin is not specified, it depends on crystalline polyester resin for low-temperature fixability, and it is difficult to say that sufficient low-temperature fixability can be secured, and technology for ensuring hot offset resistance Since it is not mentioned, the fixing temperature range cannot be secured.

  When a toner for solving the above problems is obtained, an image forming method for forming a high-quality image is required.

  The present invention has been made in view of the above-described prior art, that is, an image that has both excellent low-temperature fixability, high hot offset resistance, and good storage stability, and high-quality images over the long term. It is an object of the present invention to provide an image forming method capable of forming the image.

  As a result of intensive studies, the present inventors have found that, in an image forming method using a specific electrophotographic image forming toner as a developer, a supply conveyance path for supplying the developer to the developer carrying member, and not being used for development. A recovery agitation conveyance path that conveys the excess developer conveyed to the most downstream side in the conveyance direction of the supply conveyance path and the developer collected after development while stirring and supplies the mixed developer to the supply conveyance path; It has been found that the above-mentioned problems can be solved by making.

  That is, the present invention transports and supplies a two-component developer comprising an electrophotographic image forming toner and a magnetic carrier to a developer carrying member, and carries the developer on the surface to form a latent image carrying member. An image forming method comprising developing means for supplying toner to a latent image to be developed, wherein the electrophotographic image forming toner comprises a crystalline polyester resin (A), an amorphous resin (B), and And a composite resin (C) containing a condensation polymerization resin unit and an addition polymerization resin unit, containing chloroform insolubles, and stored in a thermostatic bath at 45 ° C. for 12 hours, followed by Fourier transform infrared spectroscopy A characteristic peak derived from the amorphous resin (B) is defined as C, which is a characteristic peak height derived from the crystalline polyester resin (A) when measured by a total reflection method using an analytical measurement apparatus. Spectacular The peak height ratio (C / R) is 0.03 to 0.55, where R is the peak height, and the THF soluble content of the toner for electrophotographic image formation has a molecular weight distribution by GPC. The main peak has a main peak between 1000 and 10000, the half width of the main peak is 15000 or less, the developing means has a supply conveyance path and a recovery stirring conveyance path, and the supply conveyance path is The developer is transported to and supplied to the developer carrier, and the recovery agitation transport path is not used for development, and the developer is transported to the most downstream side in the transport direction of the supply transport path and after development. The collected developer is conveyed while stirring and supplied to the supply conveyance path, and the supply conveyance path and the recovery agitation conveyance path have a structure that is independent from each other at least at portions excluding both ends in the longitudinal direction. Image formation characterized by It is the law.

  According to the present invention, there is provided an image forming method capable of forming a high-quality image even in the long term while achieving both excellent low-temperature fixability, high hot offset resistance, and good storage stability. can do.

It is a graph which shows the peak height C (1183 cm < ^-1 >, baseline: 1158-1120 cm < ^-1 >) of the characteristic spectrum in the crystalline state of crystalline polyester resin (A). It is a graph which shows the peak height R (829 cm < ^-1 >, baseline: 784-889 cm < ^-1 >) of the characteristic spectrum in case an amorphous resin (B) is amorphous polyester. It is a graph which shows the peak height R (699 cm < ^-1 >, baseline: 670-714 cm < ^-1 >) of the characteristic spectrum in case an amorphous resin (B) is an amorphous styrene-acrylic resin. It is a graph showing the X-ray-diffraction result of crystalline polyester resin a-6 used in the Example. 6 is a graph showing an X-ray diffraction result of the toner of Example 30. 1 is a schematic diagram illustrating a configuration in an embodiment of an image forming apparatus capable of performing an image forming method according to the present invention. FIG. 6 is an enlarged schematic view showing another image forming apparatus shown as a reference for explaining the image forming method according to the present invention. FIG. 6 is a schematic diagram illustrating a configuration of another image forming apparatus shown as a reference for explaining an image forming method according to the present invention. It is the schematic which shows the further another structure of the other image forming apparatus shown as reference in order to demonstrate the image forming method which concerns on this invention. 1 is a schematic diagram illustrating a configuration in an embodiment of a developing device according to the present invention. FIG. 3 is a schematic diagram illustrating a developer flow in a developer conveyance path according to the present invention. It is the schematic which shows the flow of the developer of the image development apparatus concerning this invention. FIG. 2 is a diagram showing an outline around a photosensitive member when the developing device according to the present invention is used. FIG. 3 is a schematic diagram illustrating a configuration of a developer supply / conveyance member and a developer agitation / conveyance member of the developing device according to the present invention. FIG. 4 is a schematic diagram illustrating a developer flow in a developer supply / conveyance member and a developer agitation / conveyance member of the developing device according to the present invention. It is the schematic which shows the structure in one Embodiment of the process cartridge which concerns on this invention.

  In the image forming method according to the present invention, a two-component developer composed of an electrophotographic image forming toner and a magnetic carrier is conveyed and supplied to a developer carrier, the developer is carried on the surface, and a latent image is formed. An image forming method having a developing means for supplying toner to a latent image formed on a carrier and performing development, the electrophotographic image forming toner comprising a crystalline polyester resin (A) and an amorphous resin (B) and a composite resin (C) containing a condensation polymerization resin unit and an addition polymerization resin unit, containing chloroform insoluble matter, and Fourier-saved for 12 hours in a 45 ° C. constant temperature bath The peak height of the characteristic spectrum derived from the crystalline polyester resin (A) when measured by a total reflection method using a conversion infrared spectroscopic analyzer is C, and the amorphous resin (B) Originating characteristic When the peak height of the spectrum is R, the peak height ratio (C / R) is 0.03 to 0.55, and the THF soluble content of the electrophotographic image forming toner is a molecular weight distribution by GPC. Has a main peak between 1000 and 10000, the half width of the main peak is 15000 or less, the developing means has a supply conveyance path and a recovery agitation conveyance path, and the supply conveyance path is The developer is transported to and supplied to the developer carrying member, and the recovery stirring and transporting path is not used for development, and the developer and the surplus developer transported to the most downstream side in the transporting direction of the supply transporting path are developed. The developer collected later is conveyed while being agitated and supplied to the supply conveyance path, and the supply conveyance path and the recovery agitation conveyance path have a structure independent from each other at least at portions excluding both ends in the longitudinal direction. It is characterized by .

The present invention is described in further detail below.
Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are attached thereto, but the scope of the present invention is intended to limit the present invention in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

  In recent years, there has been a demand for low-temperature fixing of electrophotographic image forming toner (hereinafter sometimes simply referred to as toner) in electrophotography. This is due not only to energy saving by reducing the energy required for fixing, but also to the demand for higher speed and higher image quality of the electrophotographic image forming apparatus, and the purpose of use of the electrophotographic image forming apparatus is diversified. The demand is also increasing.

  In order to simply fix the toner at a low temperature, the softening temperature (T1 / 2) of the toner may be lowered. However, when the softening temperature is lowered, the glass transition temperature is also lowered, and the heat resistant storage stability is deteriorated. In addition, since the lower limit of the fixable temperature (fixing lower limit temperature) at which no problem occurs in image quality is lowered, the upper limit of fixing temperature (fixing upper limit temperature) is also lowered, so that the hot offset resistance is also impaired. Therefore, it has been a very difficult proposition for designers of electrophotographic image forming toners to achieve both low-temperature fixability, heat-resistant storage stability, and hot offset resistance.

Therefore, the use of a crystalline resin has sharp melt properties and excellent low-temperature fixability, while the amount of crystalline resin on the toner surface can be kept within a certain value to achieve both heat-resistant storage stability. The present inventor found out in the past examination. When a toner configuration based on this technical concept is used, it is excellent in low-temperature fixability, hot offset resistance and heat-resistant storage stability.
However, when it is used in a state where the toner / carrier ratio in the developing machine is low, such as when developing an image with a high printing rate when actually used in an MFP (multifunctional printer) or copying machine, The frictional force and shearing force applied to the toner increase, toner particle cracking, chipping of the toner particle size distribution due to chipping, decrease in chargeability, detachment of external additives, deterioration of powder characteristics due to embedding, etc. As a result, adhesion, accumulation, and solidification (spent) of the toner component on the carrier surface occurred, and the problems of a decrease in charge amount, background contamination, and toner scattering became apparent.

  As a result of intensive studies on the proposition, the present inventors have found the following technical concept and have solved the above problems.

<Image forming method>
A two-component developer composed of an electrophotographic image forming toner and a magnetic carrier is conveyed and supplied to a developer carrier, the developer is carried on the surface, and the toner is supplied to a latent image formed on the latent image carrier. Then, in the image forming method having a developing means for performing development, the developing means has a supply transport path and a recovery stirring transport path, and the supply transport path causes the developer to adhere to the developer carrier. The recovered agitation transport path is not used for development and stirs the excess developer transported to the most downstream side in the transport direction of the supply transport path and the developer recovered after development. It conveys and supplies to a supply conveyance path, It is characterized by the above-mentioned.

  The developer on the developer carrying member is conveyed along the axial direction of the developer carrying member. This conveyance is performed by a supply conveyance path provided with a developer supply conveyance member that supplies the developer to the developer carrying member. The developer is recovered from the developer carrying member after toner is supplied to the latent image at a location facing the latent image carrying member to develop the latent image.

  This recovery is performed in a recovery stirring and conveying path provided with a developer stirring and conveying member that conveys the developer along the axial direction of the developer carrying member and in the direction opposite to the developer supply and conveying member. In this recovery agitation transport path, surplus developer transported to the most downstream side in the transport direction of the supply transport path without being used for development is transported, and further the developer recovered from the developer carrier is supplied. Therefore, by providing a member that stirs both, the excess developer and the recovered developer are conveyed while being stirred.

  As a result, the recovered developer after development is stirred with the surplus developer that circulates in the developing machine without being developed, so that it does not exist in a state where the toner ratio is low. A state where a rubbing force or a shearing force is applied can be avoided.

  Further, by providing a partition member or the like between the supply conveyance path and the recovery agitation conveyance path, if both conveyance paths are made independent, the developer is supplied again to the developer carrying member with insufficient stirring. The situation that is done is also avoided. As a result, it is possible to provide an image with low density unevenness on the recording medium while having both low-temperature fixability, hot offset resistance, and heat-resistant storage stability of the toner, and at the same time, with respect to fluctuations in toner density due to toner supply. A quick response is possible, and the life of the developer can be extended.

In the present invention, the recovery stirring and conveying path can be different.
That is, the recovery agitation conveyance path, a recovery conveyance path for agitating and conveying the developer collected after development, and an excess developer conveyed to the most downstream side in the conveyance direction of the supply conveyance path without being used for development; It can be set as the stirring conveyance path which conveys the developer collect | recovered after image development, stirring. In addition, both need to have a mutually independent structure at the part except a longitudinal direction both ends.

That is, the developer transport path includes: (i) a supply transport path including a developer supply transport member that transports the developer along the axial direction of the developer carrier and supplies the developer to the developer carrier; ,
(Ii) The developer recovered from the developer carrying member after passing through the portion facing the latent image carrying member along the axial direction of the developer carrying member, and the developer supply / conveying member A recovery transport path including a developer recovery transport member that transports in the same direction as
(Iii) Excess developer transported to the most downstream side in the transport direction of the supply transport path without being used for development, and the most downstream side in the transport direction of the developer recovery transport path recovered from the developer carrier Is supplied to the recovered developer transported up to, and is opposite to the developer supply transport member while stirring the excess developer and the recovered developer along the axial direction of the developer carrier. A developer agitating and conveying member that conveys the developer in the direction, and a stirring and conveying path for supplying the developer to the supply and conveying path;
It can be set as the structure which has these.
The three developer transport paths composed of the supply transport path, the recovery transport path, and the agitation transport path are independent from each other by the partition members, which is more sufficient than the above-described configuration (the configuration for the recovery agitation transport path). In addition, the recovered developer and excess developer can be agitated.

That is, the image forming method of the present invention includes a supply conveyance path by a developer supply conveyance member (first axis), an agitation conveyance path by a developer agitation conveyance member (second axis), and a developer recovery conveyance member (third axis). Or a recovery conveyance path by a developer supply conveyance member (first axis) and a recovery agitation conveyance path by a developer agitation conveyance member (second axis). It is preferable to use one conveyance path as a requirement, and in any case, an independent conveyance path is formed by a partition member because an image with little density unevenness can be provided on the recording medium.
Hereinafter, the former development method may be referred to as triaxial circulation development, and the latter development method may be referred to as biaxial circulation development.

  What is common to both is that the developer supplied to the development region by the developer supply and transport member does not return to the supply transport path as it is, but is sent directly or via the recovery transport path to the stirring transport path. After passing through the stirring step, it is sent again to the supply conveyance path.

  In the former three-axis development method, the developer that has passed through the development region is once collected in the collection conveyance path (third axis) and sent to the agitation conveyance path (three-axis circulation development method). On the other hand, in the latter two-axis development method, there is no collection conveyance path by the developer collection conveyance member, and the developer that has passed through the development area is sent directly to the stirring conveyance path (biaxial circulation development method). ).

  In any of the development methods, the developer that has passed through the supply conveyance path without being supplied to the development area, and the developer that has passed through the development area and has been collected in the agitation conveyance path or the collection conveyance path, And are fed to the supply conveyance path.

  For this reason, the developer having a reduced toner concentration because it is used for development does not enter the supply conveyance path, so that uneven toner adhesion due to uneven toner concentration is less likely to occur during development. Therefore, it is possible to provide an image with a stable density in any part on the recording medium.

The configuration of the image forming apparatus can be achieved by either the triaxial cyclic development system or the biaxial cyclic development system. However, the developer may be used when the image forming apparatus is used at a high speed or when printing is continued at a high density. However, the triaxial development method is preferable because the developer after use in development and the surplus developer can be sufficiently stirred and uniformized.
However, it is also possible to use a biaxial circulating development system, such as when using at medium speed or low speed, or when the size of the developing machine is limited.

<Toner>
When the crystalline polyester resin (A) is used as the binder resin used in the electrophotographic image forming toner, the toner can be provided with low-temperature fixability and heat-resistant storage stability due to its sharp melt property.

However, when the crystalline polyester resin (A) is used alone as the binder resin, the hot offset resistance is very poor, and the fixing temperature range becomes very narrow and cannot be practically used.
Therefore, the present inventors use a non-crystalline resin (B) containing a chloroform-insoluble content together with the crystalline polyester resin (A), thereby improving hot offset resistance and having a wide range of fixing temperatures. I thought I could make it.

  However, in the case where only the crystalline polyester resin (A) and the amorphous resin (B) are formulated, if the amount of the amorphous resin (B) is too much, the low-temperature fixability is reduced. When there is much crystalline polyester resin (A), when melt-kneading is performed in a manufacturing process, it will be compatible with components other than the chloroform insoluble part of non-crystalline resin (B), and non-crystalline resin (B) Since the glass transition temperature is remarkably lowered, the heat resistant storage stability is extremely deteriorated.

  As a result of intensive studies by the inventor, the molecular weight distribution of the toner by GPC (gel permeation chromatography) determined by THF (tetrahydrofuran) soluble content has a main peak between 1000 and 10,000. And by setting the half width of the molecular weight distribution to 15000 or less, the absolute amount of the low molecular weight is large and the molecular weight distribution becomes sharp, and the distribution of the crystalline polyester resin (A) is reduced to suppress the compatibility. The present inventors have found that the hot offset resistance of an amorphous resin containing a chloroform-insoluble component is not inhibited while assisting the low-temperature fixability of the crystalline polyester resin (A).

However, even in this case, the risk to heat-resistant storage is not completely eliminated. Even if the compatibility of the crystalline polyester resin (A) is suppressed and the decrease in the glass transition temperature of the binder resin is suppressed, if the crystalline polyester resin (A) exists with a large dispersion diameter, the crystalline polyester resin (A A) tends to appear excessively on the toner surface. Since the crystalline polyester resin (A) is a sharp melt material, when it is present inside the toner particles, it exhibits excellent heat-resistant storage stability as described above, but it melts slightly even at temperatures below the glass transition temperature. When present on the surface of the toner particles, the slightly melted crystalline polyester resin (A) acts as a binder between the toner particles, and as a result, the heat resistant storage stability of the toner is deteriorated. This phenomenon is particularly remarkable in a crystalline polyester resin having a low crystallinity.
In addition, if the crystalline polyester resin (A) is excessively present on the toner surface, filming on an OPC (Organic Photo Conductor) is likely to occur during image formation, resulting in a high risk of image quality. Become.

  Further, from the viewpoint of the electrical characteristics of the toner, there is a concern with the toner having a prescription combining the crystalline polyester resin (A) and the amorphous resin. Since the polyester resin having crystallinity has a relatively low electric resistance, if it exists in the toner with a large dispersion diameter, the electric resistance of the toner tends to decrease. If the electrical resistance is low and exceeds the allowable range, it may cause transfer failure in the transfer process during image formation. In particular, when the compatibility of the crystalline polyester resin (A) is suppressed for the purpose of maintaining the low-temperature fixability as described above, the crystalline polyester resin (A) can easily maintain a state with a large dispersion diameter, and the crystalline Since the electrical characteristics of the polyester resin (A) tend to be dominant in the toner, the electrical resistance tends to decrease.

  In addition, when a resistance adjusting agent is contained as described later, the resistance adjusting agent cannot enter the domain of the crystalline polyester resin (A). Means a binder resin excluding the crystalline polyester resin (A).) In a relatively high concentration state. For this reason, the aggregate is easily confined in the toner, and the resistance is likely to be excessively reduced. If the resistance adjuster is used only for the purpose of reducing the resistance, it may be solved by adjusting the prescription amount of the resistance adjuster. When serving also as an agent, the prescription amount may not be reduced from the viewpoint of coloring power, and may not be adjusted to an optimum electrical resistance.

  The present inventors have intensively studied to solve these technical problems. As a result, with respect to the combination of the crystalline polyester resin (A) and the amorphous resin (B), a composite resin (C) including a condensation polymerization resin unit and an addition polymerization resin unit is further formulated. The effect that it is possible to simultaneously solve the concern about the decrease in heat storage stability and the concern about the decrease in electrical resistance, which are characteristically expressed when the crystalline polyester resin (A) and the amorphous resin (B) are combined. I found it.

  It has been conventionally known that when the composite resin (C) is formulated, the dispersion of the release agent is improved. However, the molecular weight distribution of the toner by GPC obtained from the crystalline polyester resin (A) and the THF-soluble matter. When the melt kneading is performed in combination with a low molecular weight amorphous resin (B) having a main peak between 1000 and 10000 and a half-value width of molecular weight distribution of 15000 or less, the viscosity of the resin Since it significantly decreases, the raw material is less likely to be sheared and the dispersion diameter of the crystalline polyester resin (A) tends to be larger. Therefore, when the composite resin (C) is added together with the crystalline polyester resin (A) and the amorphous resin (B) and melt-kneaded, a moderate share is applied. Decentralization is encouraged.

  When the crystalline polyester resin (A) is in a finely dispersed state, the frequency of the crystalline polyester resin (A) appearing on the toner surface during pulverization decreases, and the heat resistant storage stability is dramatically improved. Moreover, since the crystalline polyester resin (A) is finely dispersed, it is possible to maintain an appropriate electrical resistance.

Furthermore, since the composite resin (C) is harder than the amorphous resin (B) having a peak of molecular weight distribution in a relatively low molecular weight region, it tends to be an interface at the time of pulverization. Therefore, the non-crystalline resin (B-2), which is relatively easily present on the toner surface and has a low softening temperature, has an effect of reducing the probability of appearing on the toner surface, which contributes to improvement in heat resistant storage stability.
In addition, although mentioned later, it is preferable that an amorphous resin (B) contains an amorphous resin (B-1) and an amorphous resin (B-2).

  In addition, since the hardness of the toner surface can be increased, there is little toner deterioration when physical stress is applied to the toner. In particular, since the phenomenon in which the external additive is excessively embedded is improved, the change in charging characteristics before and after the application of stress is reduced, and stable image quality can be provided over a long period of time.

  However, even if the crystalline polyester resin (A), the amorphous resin (B), and the composite resin (C) are used in combination, the melted kneading in the pulverized toner manufacturing process results from the thermal characteristics of the raw material resin. The advantages of doing this may not be demonstrated. This is mainly due to the fact that in the melt-kneading step, the molecular chains of the resin are broken and the molecular weight changes. In particular, when the chain of molecules insoluble in chloroform contained in the amorphous resin is broken, the molecular weight distribution of the entire toner becomes broad and the low-temperature fixability is impaired.

  As a result of extensive studies by the present inventors, for example, as will be described later, the crystalline polyester resin (A) is obtained while optimizing the share of the raw material resin by performing melt kneading while appropriately applying temperature. By adopting a technique such as recrystallization in the cooling step, the molecular weight distribution of the toner by GPC determined by the THF soluble content has a main peak between 1000 and 10,000, and the half width of the molecular weight distribution is reduced. By setting it to 15000 or less, a low molecular weight has a large absolute amount and a sharp molecular weight distribution, and the characteristics of the crystalline polyester resin (A), the amorphous resin (B), and the composite resin (C), respectively. We have found that it is possible to provide a toner having excellent low-temperature fixing, heat-resistant storage stability, and hot offset resistance, utilizing

  In particular, the effects and side effects of the crystalline polyester resin (A) are greatly influenced by the amount of the crystalline polyester resin (A) present on the toner surface, so the amount of the crystalline polyester resin (A) formulated and the composite resin (C) Low-temperature fixing by optimizing the proportion of crystalline polyester resin (A) present on the toner surface by balancing the dispersity of the crystalline polyester resin (A) caused by toner and the method used in the kneading process. In addition, the heat-resistant storage stability can be kept very good while securing the properties, and in addition, filming to OPC during image formation can be suppressed.

  The abundance ratio of the crystalline polyester resin (A) on the toner surface can be represented by a peak height ratio of a spectrum by a total reflection method (ATR method) using a Fourier transform infrared spectroscopic analyzer (FT-IR). . As a result of examination by the present inventors in consideration of heat-resistant storage stability, the peak height of the spectrum after storage for 12 hours in a 45 ° C. environment is a state after high-temperature storage (high-temperature storage) assuming ship transportation. The characteristic spectral peak height C of the crystalline polyester resin (A) after storage at 45 ° C. for 12 hours and the characteristic spectral peak height R of the amorphous resin (B) By making the ratio (C / R) in the range of 0.03 to 0.55, it is possible to keep the heat-resistant storage stability very well while ensuring the low-temperature fixability. The present inventors have found that filming to OPC at the time of image can also be suppressed.

  When the peak height ratio (C / R) is higher than 0.55, the crystalline polyester resin (A) on the toner surface becomes excessive, resulting in poor heat storage stability and filming resistance. On the other hand, if it is less than 0.03, the amount of the crystalline polyester resin (A) on the toner surface is too small, and the efficiency for low-temperature fixing deteriorates.

  As described above, the ratio of the crystalline polyester resin (A) present on the toner surface: the peak height ratio (C / R) depends on the prescription amount, dispersity, and kneading step of the crystalline polyester resin (A). It can be controlled by the construction method. For example, increasing the prescription amount of the crystalline polyester resin (A) increases C / R. When the amount of the composite resin (C) is increased to improve dispersibility, the C / R is lowered. Further, if the cooling time is lengthened in the kneading step, recrystallization is promoted, so C / R increases. The control method of C / R is not limited to these, and any method may be used as long as C / R is in the range of 0.03 to 0.55.

  The peak height ratio (C / R) between the characteristic peak height C of the crystalline polyester resin and the characteristic peak height R of the amorphous polyester resin is FT-IR (Fourier transform). It was determined from the ATR spectrum by the ATR method (total reflection method) using an infrared spectroscopic analyzer “Avatar 370 (manufactured by Thermo Electron)”. In addition, since the ATR method requires measurement on a smooth surface, the measurement was performed by pressure molding the toner into pellets. In the pressure molding, 1000 kg of toner was applied to 0.6 g of toner for 30 seconds to produce a pellet having a diameter of 20 mm.

FIG. 1 shows an example of an infrared absorption spectrum of a crystalline polyester resin.
As shown in FIG. 1, the infrared absorption spectrum of the crystalline polyester resin has a falling peak point (hereinafter “first falling peak point”) at which the absorbance becomes the smallest between wave numbers 1130 cm ^{−1 to} 1220 cm ^−1. There is a maximum rising peak point Mp at which the absorbance is maximum between the falling peak point where the absorbance is the second smallest (hereinafter referred to as “second falling peak point Fp2”). A line segment connecting the first falling peak point Fp1 and the second falling peak point Fp2 is defined as a base line. Then, a perpendicular line is drawn from the maximum rising peak point Mp toward the horizontal axis, and the absolute value of the difference between the absorbance at the intersection with the baseline and the absorbance at the maximum rising peak point Mp is expressed as the height C of the maximum rising peak point Mp. And
In the example shown in FIG. 1, Fp1 is 1158 cm ⁻¹ , Fp2 is 1201 cm ⁻¹ (that is, the baseline is 1158 cm ^{−1 to} 1201 cm ⁻¹ ), and Mp is 1183 cm ⁻¹ .

FIG. 2 shows an example of an infrared absorption spectrum of an amorphous polyester resin.
As shown in FIG. 2, the infrared absorption spectrum of the non-crystalline polyester resin has a maximum rising peak point Mp and a first falling peak point Fp1 at which the absorbance is minimum between wave numbers 780 cm ^{−1 to} 900 cm ^−1. The second falling peak point Fp2 has the second lowest absorbance, and the maximum rising peak point Mp is located between the first falling peak point Fp1 and the second falling peak point Fp2. A line segment connecting the first falling peak point Fp1 and the second falling peak point Fp2 is defined as a base line. Then, a vertical line is drawn from the maximum rising peak point Mp toward the horizontal axis, and the absolute value of the difference between the absorbance at the intersection with the baseline and the absorbance at the maximum rising peak point Mp is expressed as the height of the maximum rising peak point Mp. Let R be. Further, C / R is a peak ratio (C / R value).
In the example shown in FIG. 2, Fp1 is 784 cm ⁻¹ , Fp2 is 889 cm ⁻¹ (that is, the baseline is 784 cm ^{−1 to} 889 cm ⁻¹ ), and Mp is 829 cm ⁻¹ .

FIG. 3 shows an example of an infrared absorption spectrum of an amorphous styrene-acrylic resin.
As shown in FIG. 3, the infrared absorption spectrum of the amorphous styrene-acrylic resin has a maximum rising peak point Mp and a first falling edge at which the absorbance is minimum between wave numbers 660 cm ^{−1 to} 720 cm ^−1. There is a peak point Fp1 and a second falling peak point Fp2 with the second smallest absorbance, and the maximum rising peak point Mp is located between the first falling peak point Fp1 and the second falling peak point Fp2. Yes. A line segment connecting the first falling peak point Fp1 and the second falling peak point Fp2 is defined as a base line. Then, a vertical line is drawn from the maximum rising peak point Mp toward the horizontal axis, and the absolute value of the difference between the absorbance at the intersection with the baseline and the absorbance at the maximum rising peak point Mp is expressed as the height of the maximum rising peak point Mp. Let R be. Further, C / R is a peak ratio (C / R value).
In the example shown in FIG. 3, Fp1 is 670 cm ⁻¹ , Fp2 is 714 cm ⁻¹ (that is, the baseline is 670 m ^{−1 to} 714 cm ⁻¹ ), and Mp is 699 cm ⁻¹ .

When both an amorphous polyester resin and an amorphous styrene-acrylic resin are used as the amorphous resin, the R value obtained from the maximum rising peak point Mp between wave numbers 780 cm ^{−1 to} 900 cm ^−1. The R value obtained from the maximum rising peak point Mp between wave numbers 660 cm ^{−1 to} 720 cm ⁻¹ is compared, and the stronger one is adopted to obtain the peak ratio (C / R value).

  The content of the crystalline polyester resin (A) in the toner is preferably 1 to 15% by mass, more preferably 1 to 10% by mass. The content of the amorphous resin (B-1) is preferably 10 to 40% by mass, the content of the amorphous resin (B-2) is preferably 50 to 90% by mass, and the composite resin (C) The content of is preferably 3 to 20% by mass.

GPC (gel permeation chromatography) is measured as follows.
Stabilize the column in a heat chamber at 40 ° C., flow THF at a flow rate of 1 ml / min through the column at this temperature, and prepare a THF sample solution of resin prepared at a sample concentration of 0.05 to 0.6% by weight. Is measured by injecting 50 to 200 μl.
In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the prepared calibration curve and the count using several types of monodisperse polystyrene standard samples.
As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Alternatively Toyo Soda Kogyo Co., Ltd. having a molecular weight of ^{6 × 10 2, 2.1 × 10} 3, 4 × 10 3, 1.75 × 10 4, 5.1 × 10 4, 1.1 × 10 5, 3.9 It is suitable to use x10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

  As an amorphous resin (B), an amorphous resin (B-1) and an amorphous resin (B-) whose softening temperature (T1 / 2) is 25 ° C. or lower lower than that of the amorphous resin (B-1) And 2) are preferably used. By using two types of the non-crystalline resin (B-1) and the non-crystalline resin (B-2), the distribution of the crystalline polyester resin (A) is reduced to suppress compatibility, and In addition, the non-crystalline resin (B-2) assists the low-temperature fixability of the crystalline polyester resin (A), and also inhibits hot offset resistance due to the chloroform-insoluble matter of the non-crystalline resin (B-1). This is preferable.

The softening temperature (T1 / 2) of the binder resin is as follows: an elevated flow tester CFT-500 (manufactured by Shimadzu Corporation), a die hole diameter of 1 mm, a pressure of 20 kg / cm ² , and a temperature increase rate of 6 ° C./min. The temperature is measured at a temperature corresponding to ½ from the outflow start point to the outflow end point when a 1 cm ³ sample is melted out.

  As the crystalline polyester resin (A) in the present invention, a conventionally known one can be used, but more preferably, it contains an ester bond represented by the following general formula (1) in its molecular main chain. preferable.

[-OCO-R-COO- (CH 2) n -] Formula (1)
(In the formula, R represents a linear unsaturated aliphatic divalent carboxylic acid residue having 2 to 20 carbon atoms, and n represents an integer of 2 to 20).

The presence of the structure of the general formula (1) can be confirmed by solid C ¹³ NMR.

  Specific examples of the linear unsaturated aliphatic group include linear unsaturated divalent carboxylic acids such as maleic acid, fumaric acid, 1,3-n-propene dicarboxylic acid, and 1,4-n-butene dicarboxylic acid. Examples include acid-derived linear unsaturated aliphatic groups.

In the general formula (1), (CH ₂ ) _n represents a linear aliphatic dihydric alcohol residue. Specific examples of the linear aliphatic dihydric alcohol residue in this case include linear aliphatic 2 such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol. Those derived from a monohydric alcohol.

  The crystalline polyester resin (A) has an advantage that a linear unsaturated aliphatic dicarboxylic acid is used as its acid component, so that a crystalline structure can be formed more easily than when an aromatic dicarboxylic acid is used. The function of the conductive polyester resin can be exhibited more effectively.

  The crystalline polyester resin (A) is, for example, from (i) a linear unsaturated aliphatic divalent carboxylic acid or a reactive derivative thereof (an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, an acid halide, etc.). And (ii) a polyhydric alcohol component comprising a linear aliphatic diol can be produced by a polycondensation reaction. In this case, a small amount of other polyvalent carboxylic acid may be added to the polyvalent carboxylic acid component as necessary.

  In this case, the polyvalent carboxylic acid includes (i) an unsaturated aliphatic divalent carboxylic acid having a branched chain, (ii) a saturated aliphatic divalent carboxylic acid, a saturated aliphatic trivalent carboxylic acid, and the like. Examples include polyvalent carboxylic acids, (iii) aromatic polyvalent carboxylic acids such as aromatic divalent carboxylic acids and aromatic trivalent carboxylic acids.

  The addition amount of these polyvalent carboxylic acids is usually 30 mol% or less, preferably 10 mol% or less, based on the total carboxylic acid, and is appropriately added within the range where the resulting polyester has crystallinity.

  Specific examples of polyvalent carboxylic acids that can be added as needed include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. Divalent carboxylic acid; trimetic anhydride, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1 , 2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, trivalent or higher polyvalent carboxylic acid such as 1,2,7,8-octanetetracarboxylic acid, and the like.

A trivalent or higher polyhydric alcohol may be added to the polyhydric alcohol component, if necessary, in addition to a small amount of an aliphatic branched dihydric alcohol or cyclic dihydric alcohol.
The addition amount is 30 mol% or less, preferably 10 mol% or less, based on the total alcohol, and is appropriately added within the range in which the resulting polyester has crystallinity.

  Examples of polyhydric alcohol added as needed include 1,4-bis (hydroxymethyl) cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin and the like.

In the crystalline polyester resin (A), the molecular weight distribution is preferably sharp from the viewpoint of low-temperature fixability, and the molecular weight is preferably a relatively low molecular weight.
As for the molecular weight of the crystalline polyester resin (A), the weight average molecular weight (Mw) is 5500-6500, the number average molecular weight (Mn) is 1300-1500 and Mw / It is preferable that Mn ratio is 2-5.

  The molecular weight distribution of the crystalline polyester resin (A) is based on a molecular weight distribution chart in which the horizontal axis is log (M: molecular weight) and the vertical axis is weight%. In the case of the crystalline polyester resin (A) used in the present invention, in this molecular weight distribution diagram, it is preferable to have a molecular weight peak in the range of 3.5 to 4.0 (wt%), and the half width of the peak is It is preferable that it is 1.5 or less.

  In the crystalline polyester resin (A), the glass transition temperature (Tg) and the softening temperature (T1 / 2) are desirably low as long as the heat-resistant storage stability of the toner is not deteriorated. It is 80-130 degreeC, Preferably it is 80-125 degreeC, The T1 / 2 is 80-130 degreeC, Preferably it is 80-125 degreeC. When Tg and T1 / 2 are higher than the above ranges, the toner fixing lower limit temperature is increased, and the low-temperature fixability is deteriorated. When Tg and T1 / 2 are lower than the above ranges, the heat resistant storage stability of the toner is deteriorated.

  Whether or not the crystalline polyester resin (A) in the present invention has crystallinity can be confirmed by whether or not a peak exists in the X-ray diffraction pattern by the powder X-ray diffractometer.

  The crystalline polyester resin (A) used in the present invention has at least one diffraction peak at a position where 2θ is 19 ° to 25 ° in the diffraction pattern, and more preferably 2θ is (i) 19 ° to 20 °. It is preferable that diffraction peaks exist at positions of °, (ii) 21 ° to 22 °, (iii) 23 ° to 25 °, and (iv) 29 ° to 31 °. Even after toner formation, a diffraction peak exists at a position of 2θ = 19 ° to 25 °, that is, it indicates that the crystalline polyester resin (A) maintains the crystallinity, and the crystalline polyester resin ( This is preferable because the function A) can be surely exhibited.

  The powder X-ray diffraction measurement was performed using a Rigaku Electric RINT1100, using a wide-angle goniometer under the conditions of a tube ball of Cu and a tube voltage-current of 50 kV to 30 mA.

  FIG. 4 shows an X-ray diffraction result of the crystalline polyester resin a-6 (details will be described later) used in the example, and FIG. 5 shows an X-ray diffraction result of the toner of Example 30.

  The amorphous resin (B) used in the present invention preferably contains a chloroform-insoluble component, and the amorphous resin (B) comprises an amorphous resin (B-1) and an amorphous resin (B-2). More preferably, the amorphous resin (B-1) contains a chloroform-insoluble component. In particular, it is preferable that the non-crystalline resin (B-1) contains 5 to 40% by weight of a chloroform-insoluble component because hot offset resistance is easily exhibited. Further, when the amount of insoluble chloroform in the toner is 1 to 30% by weight after the toner is formed, distribution of resins other than the non-crystalline resin (B-1) can be secured while maintaining hot offset resistance. Therefore, it is preferable. When the amount of insoluble chloroform in the toner is less than 1% by weight, the hot offset resistance due to the insoluble matter in chloroform is diluted, and when the amount is more than 30% by weight, the amount of binder resin that contributes to low-temperature fixability is distributed. Therefore, the low-temperature fixability deteriorates.

The chloroform insoluble matter is measured as follows.
About 1.0 g of toner (or binder resin) is weighed, and about 50 g of chloroform is added thereto. The sufficiently dissolved solution is separated by centrifugation, and filtered at room temperature using JIS standard (P3801) type 5 C qualitative filter paper. The filter paper residue is insoluble, and the ratio of the weight of toner used to the weight of the filter paper residue (% by weight) represents the content of chloroform insoluble matter.
When measuring the insoluble matter in chloroform when the toner is used, about 1.0 g of the toner is weighed out in the same manner as the binder resin, but solid matter such as pigment is present in the filter paper residue. Therefore, it is obtained separately by thermal analysis.

  The amorphous resin (B-2) used in the present invention preferably has a softening temperature (T1 / 2) lower by 25 ° C. or more than the amorphous resin (B-1). This is because the non-crystalline resin (B-2) contributes to the lower limit of fixing to assist the low-temperature fixability of the crystalline polyester resin (A), and the non-crystalline resin (B-1) is insoluble in chloroform. The role of the non-crystalline resin (B-1) and the non-crystalline resin (B-2) is divided and the functions are separated, such as the hot offset resistance resulting from the above, that is, the function contributing to the upper limit of fixing. It is.

  The amorphous resin (B-2) preferably has a main peak between 1000 to 10,000 in the molecular weight distribution by GPC determined by the THF soluble content, and the half width of the molecular weight distribution is preferably 15000 or less. . Since such an amorphous resin (B-2) exhibits very good low-temperature fixability, even when the amount of the crystalline polyester resin (A) is reduced when formulated into a toner, the low-temperature fixability is sufficiently assisted. be able to. Further, paradoxically, even when the amorphous resin (B-2) having the molecular weight distribution described above is used, the toner has a main peak between 1000 and 10,000 in the molecular weight distribution, and the half-value width is 15000 or less. If so, the proportion of the non-crystalline resin (B-2) in the binder resin constituting the toner becomes high. As a result of repeated studies by the present inventors, a toner having a combination of a crystalline polyester resin (A), an amorphous resin (B-1), an amorphous resin (B-2), and a composite resin (C) When the ratio of the amorphous resin (B-2) is increased, the balance is the best, and the side effects due to excessive crystalline polyester resin and excessive THF insoluble matter and the lower limit of fixing due to the composite resin (C) are achieved. It has been found that the adverse effects of the resin are not manifested, the functions of the respective resins are effectively exhibited, and the low-temperature fixability, heat-resistant storage stability, and hot-offset resistance are improved.

  Therefore, the toner for electrophotographic image formation according to the present invention has a main peak in which the molecular weight distribution by GPC determined by the THF soluble content is 1000 to 10,000, and the half-value width of the molecular weight distribution is 15000 or less. It is preferable.

  In the present invention, as described above, the amorphous resin (B-1) and the amorphous resin (B-2) include the insoluble matter of chloroform in the amorphous resin (B-1) and the amorphous resin. It is preferable that the appropriate molecular weight distribution of the resin (B-2) and the magnitude relationship between the softening temperatures of the amorphous resin (B-1) and the amorphous resin (B-2) are satisfied. Conventionally known materials can be used. For example, the following resins can be used. These resins are not limited to single use but can be used in combination of two or more.

Polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / Maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer) Styrene / phenyl acrylate copolymer), styrene / methacrylic acid ester copolymer (styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene) / Phenyl methacrylate copolymer, etc.) Styrene resins (homopolymers or copolymers containing styrene or styrene-substituted products) such as styrene / α-chloromethyl acrylate copolymer, styrene / acrylonitrile / acrylate ester copolymer, vinyl chloride resin, styrene / Vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin Examples include petroleum resins, hydrogenated petroleum resins, and the like.
The method for producing these resins is not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.

  The amorphous resin (B) used in the present invention is more preferably a polyester resin from the viewpoint of low-temperature fixability. For example, those usually obtained by condensation polymerization of alcohol and carboxylic acid can be used.

Examples of the alcohol include glycols such as ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, ethylated bisphenols such as 1,4-bis (hydroxymethyl) cyclohexane and bisphenol A, and other dihydric alcohols. Mention may be made of monomers and trihydric or higher polyhydric alcohol monomers.
Examples of the carboxylic acid include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid, 1,2,4-benzenetricarboxylic acid, 1 , 2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxy Mention may be made of trivalent or higher polyvalent carboxylic acid monomers such as propane and 1,2,7,8-octanetetracarboxylic acid.
In particular, the polyester resin preferably has a glass transition temperature Tg of 55 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of heat storage stability.

The composite resin (C) is a resin (also referred to as a hybrid resin) in which a condensation polymerization monomer and an addition polymerization monomer are chemically bonded.
That is, the composite resin (C) has a condensation polymerization resin unit and an addition polymerization resin unit.

  The composite resin (C) is obtained by performing a polycondensation monomer and an addition polymerization monomer as a raw material in the same reaction vessel by simultaneously performing a polycondensation reaction and an addition polymerization reaction in parallel, It can be obtained by sequentially performing an addition polymerization reaction, or an addition polymerization reaction and a condensation polymerization reaction. That is, the composite resin (C) is a resin including a condensation polymerization unit and an addition polymerization unit.

  Polycondensation monomers in the composite resin (C) include polyhydric alcohols and polycarboxylic acids that form polyester resin units, polyhydric carboxylic acids and amines that form polyamide resin units or polyester-polyamide resin units, and amino acids. Is mentioned.

  Examples of the divalent alcohol component include 1,2-propanediol, 1,3-propanediol, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, Diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, or bisphenol A with ethylene oxide, propylene oxide A diol obtained by polymerization of a cyclic ether such as

  Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Is mentioned.

  Among these, hydrogenated bisphenol A or alcohol components having a bisphenol A skeleton such as diol obtained by polymerizing cyclic ethers such as ethylene oxide and propylene oxide to bisphenol A impart heat-resistant storage stability and mechanical strength to the resin. Therefore, it can be suitably used.

Examples of the carboxylic acid component include benzene dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; and maleic acid. Unsaturated dibasic acids such as citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; unsaturated dibasic acids such as maleic anhydride, citraconic acid anhydride, itaconic acid anhydride, alkenyl succinic acid anhydride And acid anhydrides.
Examples of the trivalent or higher polyvalent carboxylic acid component include trimetic acid, pyrometic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1 , 2,4-Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxy ) Methane, 1,2,7,8-octanetetracarboxylic acid, emporic trimer acid, or their anhydrides, partially lower alkyl esters, and the like.
Among these, aromatic polyvalent carboxylic acid compounds such as phthalic acid, isophthalic acid, terephthalic acid, and trimellitic acid are preferably used from the viewpoints of heat resistant storage stability and mechanical strength of the resin.
As the amine component or amino acid component, for example, the diamine (B1), trivalent or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of B1 to B5 are blocked. (B6) etc. are mentioned.

  Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.) and alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexylmethane). , Diaminocyclohexane, isophoronediamine, etc.), aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.

  Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.

  Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline.

  Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.

  Examples of the amino acid (B5) include aminopropionic acid, aminocaproic acid, and ε-caprolactam.

  (B6) obtained by blocking the amino group of (B1) to (B5) (K6) obtained from the amines of (B1) to (B5) and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) And oxazolidine compounds.

The molar ratio of the condensation polymerization monomer component in the composite resin (C) is preferably 5 mol% to 40 mol%, more preferably 10 mol% to 25 mol%.
When the molar ratio is less than 5 mol%, the dispersibility with the polyester-based resin deteriorates, and when it exceeds 50 mol%, the dispersion of the release agent tends to deteriorate.
Moreover, when performing a condensation polymerization reaction, an esterification catalyst etc. may be used and it is possible to use all the well-known and usual catalysts.

  There is no restriction | limiting in particular as an addition polymerization type monomer in the said composite resin (C), Although it can select suitably according to the objective, A vinyl type monomer is typical.

  Examples of the vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-amyl styrene, Styrenic vinyl monomers such as p-tert-butylstyrene, pn-hexylstyrene, pn-4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; acrylic acid, acrylic acid Methyl, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, n-dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, Acrylic monomers such as acrylic acid such as phenyl acrylate Methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacryl Methacrylic acid vinyl monomers such as phenyl acid, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; other vinyl monomers or other monomers that form copolymers.

  Examples of other vinyl monomers or other monomers that form a copolymer include monoolefins such as ethylene, propylene, butylene, and isobutylene; polyenes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, vinyl bromide, Vinyl halides such as vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone, Vinyl ketones such as methyl isopropenyl ketone; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; Vinyl naphthalenes; Acrylonitrile, methacrylonitrile Acrylic acid or methacrylic acid derivatives such as acrylamide; unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride Unsaturated dibasic acid anhydrides such as alkenyl succinic anhydride; maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid monobutyl ester, citraconic acid monomethyl ester, citraconic acid monoethyl ester, citraconic acid monobutyl ester, Monoesters of unsaturated dibasic acids such as itaconic acid monomethyl ester, alkenyl succinic acid monomethyl ester, fumaric acid monomethyl ester, and mesaconic acid monomethyl ester; unsaturated dibasic acid esters such as dimethylmaleic acid and dimethylfumaric acid An α, β-unsaturated acid such as crotonic acid and cinnamic acid; an α, β-unsaturated acid anhydride such as crotonic acid anhydride and cinnamic anhydride; and the α, β-unsaturated acid and a lower fatty acid Monomers having a carboxyl group such as anhydrides, alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, these acid anhydrides or monoesters thereof; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate Acrylic acid or methacrylic acid hydroxyalkyl esters such as 4- (1-hydroxy-1-methylbutyl) styrene, monomers having a hydroxy group such as 4- (1-hydroxy-1-methylhexyl) styrene, and the like. It is done.

  Among these, styrene, acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, n-butyl methacrylate, 2-ethylhexyl methacrylate and the like are preferably used, and a combination containing at least styrene and acrylic acid Is particularly preferable because the dispersibility of the release agent is extremely good.

Furthermore, a crosslinking agent for addition polymerization monomers can be added as necessary.
Examples of the cross-linking agent include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene.

Examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, and 1,6. And xanthdiol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylates of these compounds with methacrylate.
Examples of diacrylate compounds linked by an alkyl chain containing an ether bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, and dipropylene. Examples include glycol diacrylate and those obtained by replacing acrylate of these compounds with methacrylate.
Other examples include diacrylate compounds and dimethacrylate compounds linked by a chain containing an aromatic group and an ether bond.
Examples of polyester diacrylates include trade name MANDA (manufactured by Nippon Kayaku Co., Ltd.).

  Examples of the polyfunctional crosslinking agent include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds in place of methacrylate, triallyl cyanide. Examples include nurate and triallyl trimellitate.

  The addition amount of the crosslinking agent is preferably 0.01 parts by mass to 10 parts by mass, and more preferably 0.03 parts by mass to 5 parts by mass with respect to 100 parts by mass of the addition polymerization monomer used.

There is no restriction | limiting in particular as a polymerization initiator used when superposing | polymerizing an addition polymerization type monomer, According to the objective, it can select suitably, For example, 2,2'- azobisisobutyronitrile, 2,2 Azo polymerization initiators such as' -azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile); methyl ethyl ketone peroxide, acetylacetone peroxide, 2, Peroxide polymerization initiators such as 2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, benzoyl peroxide, n-butyl-4,4-di- (tert-butylperoxy) valerate Is mentioned.
These may be used in combination of two or more for the purpose of adjusting the molecular weight and molecular weight distribution of the resin.
The addition amount of the polymerization initiator is preferably 0.01 parts by mass to 15 parts by mass, and more preferably 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the addition polymerization monomer used.

In order to chemically bond the condensation polymerization resin unit and the addition polymerization resin unit, for example, a monomer (both reactive monomers) capable of reacting in either condensation polymerization or addition polymerization is used.
Examples of such bireactive monomers include unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof; and hydroxy groups. Examples thereof include vinyl monomers.
The addition amount of the both reactive monomers is preferably 1 part by mass to 25 parts by mass, and more preferably 2 parts by mass to 20 parts by mass with respect to 100 parts by mass of the addition polymerization monomer used.

  As long as the composite resin (C) is in the same reaction vessel, both the condensation polymerization reaction and the addition polymerization reaction proceed and / or complete at the same time, and each reaction temperature and time are selected independently. The progress of the reaction can be completed.

  For example, a mixture of an addition polymerization monomer and a polymerization initiator is added dropwise to a mixture of condensation polymerization monomers in a reaction vessel in advance, and the addition polymerization is first completed by a radical polymerization reaction, and then the reaction temperature is increased. There is a method of performing condensation polymerization by raising the temperature. In this way, it is possible to effectively disperse and combine two types of resin units by advancing two independent reactions in the reaction vessel.

  The composite resin (C) is preferably a composite resin having a polyester condensation polymerization resin unit and a vinyl resin addition polymerization unit, and the function of the composite resin (C) can be exhibited more effectively. .

As a softening temperature (T1 / 2) of the said composite resin (C), 90 to 130 degreeC is preferable and 100 to 120 degreeC is more preferable.
When the softening temperature (T1 / 2) is lower than 90 ° C., heat resistant storage stability and offset resistance may be deteriorated, and when it is higher than 130 ° C., low temperature fixability may be deteriorated.
In addition, the glass transition temperature of the composite resin (C) is preferably 45 ° C. to 80 ° C., more preferably 50 ° C. to 70 ° C., and further 53 ° C. to 65 ° C. from the viewpoints of fixability, storage stability and durability. preferable.

  The acid value of the composite resin (C) is preferably 5 mgKOH / g to 80 mgKOH / g, more preferably 15 mgKOH / g to 40 mgKOH / g, from the viewpoints of chargeability and environmental stability.

The toner of the present invention can be blended with a charge control agent as required.
Examples of charge control agents include modified products of nigrosine and fatty acid metal salts, onium salts such as phosphonium salts and lake lakes thereof, triphenylmethane dyes and lake lake pigments, metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide Diorganotin oxides such as dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, organometallic complexes, chelate compounds, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, Examples include aromatic dicarboxylic acid metal complexes, quaternary ammonium salts, and salicylic acid metal compounds. In addition, there are aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, phenol derivatives such as bisphenol, etc., and any of these conventionally known charge control agents (polarity control agents). ) Can also be used alone or in combination.
The amount of these charge control agents used is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on the toner resin component.

Among these charge control agents, the inclusion of a metal salicylic acid compound is preferable because it can improve hot offset resistance at the same time. In particular, a complex having a tri- or higher-valent metal capable of a hexacoordinate configuration reacts with a highly reactive part of the resin and wax to form a light cross-linked structure, and thus has a large effect on hot offset resistance. Moreover, dispersibility improves by using together with composite resin (C), and the function of charge polarity control can be exhibited more effectively.
Here, examples of the trivalent or higher metal include Al, Fe, Cr, and Zr.
As the salicylic acid metal compound, a compound represented by the following formula can be used, and examples of the metal complex in which M is zinc include Bontron E-84 manufactured by Orient Chemical Industry Co., Ltd.

(Wherein R ² , R ³ and R ⁴ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, M is chromium, Zinc, calcium, zirconium or aluminum, m is an integer of 2 or more, and n is an integer of 1 or more)

  The electrophotographic image forming toner in the present invention has an endothermic peak attributed to the crystalline polyester resin (A) in the range of 90 to 130 ° C. in the endothermic peak measurement of the toner by DSC (Differential Scanning Calorimetry). It is preferable to have. When the endothermic peak due to the crystalline polyester resin (A) is in the range of 90 to 130 ° C., the crystalline polyester resin does not melt at room temperature, and the toner melts in a relatively low fixing temperature range, and recording is performed. Since it can be fixed on a medium, heat storage stability and low-temperature fixability can be expressed more effectively.

Also, the endothermic amount of the endothermic peak is preferably 1 J / g or more and 15 J / g or less.
When the endothermic amount is less than 1 J / g, the amount of the crystalline polyester resin that works effectively in the toner is too small, so that the function of the crystalline polyester resin is not sufficiently exhibited. If the endothermic amount is more than 15 J / g, the amount of crystalline polyester resin effective in the toner is excessive, so that the absolute amount compatible with the amorphous polyester resin increases and the glass transition temperature of the toner decreases. , Resulting in a decrease in heat resistant storage stability.

  The DSC measurement (endothermic peak, glass transition temperature Tg) in the present invention is measured by using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation) and increasing the temperature to 20 to 150 ° C. at 10 ° C./min. .

  In the present invention, the endothermic peak derived from the crystalline polyester is present in the vicinity of 80 to 130 ° C., which is the melting point of the crystalline polyester, and the endothermic amount is determined from the area surrounded by the baseline and the endothermic curve. In general, the endothermic amount in DSC measurement is often measured by increasing the temperature twice, but the endothermic peak and glass transition temperature in the present invention are measured using the endothermic curve at the first temperature increase. derive.

  When the endothermic peak derived from the crystalline polyester resin (A) overlaps with the endothermic peak of the wax, the endothermic amount of the wax is subtracted from the endothermic amount of the overlapped peak. The endothermic amount of the wax is calculated from the endothermic amount of the wax alone and the wax content in the toner.

The toner of the present invention preferably contains a fatty acid amide compound.
When the fatty acid amide compound is blended together with the crystalline polyester resin (A) to the pulverized toner including the melt-kneading step at the time of toner production, the kneaded product is cooled when the crystalline polyester resin (A) melted at the time of kneading is cooled. Since the recrystallization in the toner is promoted, the compatibility with the resin is reduced, and the decrease in the glass transition temperature of the toner can be suppressed, so that the heat resistant storage stability can be improved. Further, when used in combination with a release agent, it becomes possible to keep the release agent on the surface of the fixed image, and therefore it is resistant to rubbing (improved smear resistance).
The content of the fatty acid amide compound in the toner is preferably 0.5 to 10% by mass.

As the fatty acid amide compound, a compound represented by R ¹⁰ —CO—NR ¹² R ¹³ is used.
R ¹⁰ is an aliphatic hydrocarbon group having 10 to 30 carbon atoms, and R ¹² and R ¹³ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or carbon. It is an aralkyl group of several 7 to 10. Here, the alkyl group, aryl group, and aralkyl group of R ¹² and R ¹³ may be substituted with a generally inactive substituent such as a fluorine atom, a chlorine atom, a cyano group, an alkoxy group, or an alkylthio group. More preferably, it is unsubstituted.

  Preferable compounds include stearic acid amide, stearic acid methylamide, stearic acid diethylamide, stearic acid benzylamide, stearic acid phenylamide, behenic acid amide, behenic acid dimethylamide, myristic acid amide, palmitic acid amide and the like.

In the present invention, as the fatty acid amide compound, an alkylene bis fatty acid amide is particularly preferably used.
The alkylene bis fatty acid amide is a compound represented by the following general formula (2).

(Wherein R ²¹ and R ²³ represent an alkyl group or alkenyl group having 5 to ²¹ carbon atoms, and R ²² represents an alkylene group having 1 to 20 carbon atoms.)

Examples of the alkylene bis saturated fatty acid amide represented by the general formula (2) include methylene bis stearic acid amide, ethylene bis stearic acid amide, methylene bis palmitic acid amide, ethylene bis palmitic acid amide, methylene bis behenic acid amide, and ethylene. Examples thereof include bisbehenic acid amide, hexamethylene bisstearic acid amide, hexaethylene bispalmitic acid amide, hexamethylene bisbehenic acid amide, and the like. Of these, ethylene bis stearamide is most preferred.
These fatty acid amide compounds can also serve as a release agent on the surface of the fixing member when the softening temperature (T1 / 2) is lower than the temperature of the surface of the fixing member at the time of fixing.

  Specific examples of alkylene bis fatty acid amide compounds that can be used in addition to the above include propylene bis stearic acid amide, butylene bis stearic acid amide, methylene bis oleic acid amide, ethylene bis oleic acid amide, propylene bis oleic acid amide, Butylene bis oleic acid amide, methylene bis lauric acid amide, ethylene bis lauric acid amide, propylene bis lauric acid amide, butylene bis lauric acid amide, methylene bis myristic acid amide, ethylene bis myristic acid amide, propylene bis myristic acid amide, butylene bis Myristic acid amide, Propylene bispalmitic acid amide, Butylene bispalmitic acid amide, Methylene bispalmitoleic acid amide, Ethylene bispalmitoleic acid amide, Propylene vinyl Palmitoleic acid amide, butylene bispalmitoleic acid amide, methylene bisarachidic acid amide, ethylene bisarachidic acid amide, propylene bisarachidic acid amide, butylene bisarachidic acid amide, methylene biseicosenoic acid amide, ethylene biseicosenoic acid Amide, Propylene biseicosenoic acid amide, Butylene biseicosenoic acid amide, Methylene bis behenic acid amide, Ethylene bis behenic acid amide, Propylene bis behenic acid amide, Butylene bis behenic acid amide, Methylene bis Mention may be made of alkylene bis fatty acid amide compounds of saturated or monovalent unsaturated fatty acids such as erucic acid amide, ethylene biserucic acid amide, propylene biserucic acid amide, butylene biserucic acid amide.

  Examples of the colorant used in the toner of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, Any conventionally known dyes and pigments such as rose bengal and triallylmethane dyes can be used alone or as a mixture, and can be used as a black toner or a full color toner.

  In particular, carbon black has a good black coloring power. However, at the same time, since it is also a good conductive material, if it is used in a large amount or if it is present in an aggregated state in the toner, the electrical resistance is lowered, causing a transfer failure in the transfer process. In particular, when used in combination with the crystalline polyester resin (A), the carbon black particles cannot enter the domain of the crystalline polyester resin (A), so the crystalline polyester resin (A) exists in the toner with a large dispersion diameter. When it does, it will exist in resin other than crystalline polyester resin (A) in a state with comparatively high density | concentration. For this reason, the aggregate is easily confined in the toner, and the resistance is likely to be excessively reduced.

  In the case of this invention, since it uses together with composite resin (C), dispersion | distribution of carbon also becomes favorable and said risk can be reduced. Further, when carbon black is contained, the viscosity of the melted toner can be increased when the toner is fixed to the recording medium. Therefore, when a large amount of the amorphous resin (B-1) is formulated, the viscosity is increased. The effect that the hot offset which arises resulting from a fall can be suppressed can also be provided.

  The amount of these colorants to be used is usually 1 to 30% by weight, preferably 3 to 20% by weight, based on the toner resin component.

  A conventionally known release agent for the toner of the present invention can be used. For example, low molecular weight polyethylene wax, low molecular weight polyolefin wax such as low molecular weight polypropylene, synthetic hydrocarbon wax such as Fischer-Tropsch wax, natural waxes such as beeswax, carnauba wax, candelilla wax, rice wax, montan wax, Examples include petroleum waxes such as paraffin wax and microcrystalline wax, higher fatty acids such as stearic acid, palmitic acid, and myristic acid, metal salts of higher fatty acids, higher fatty acid amides, synthetic ester waxes, and various modified waxes thereof.

  Among these release agents, carnauba wax and its modified wax, polyethylene wax, and synthetic ester wax are preferably used. In particular, carnauba wax is very suitable because it is easily finely dispersed in a polyester resin or polyol resin, and can easily be a toner excellent in hot offset resistance, transferability and durability. Further, when used in combination with a fatty acid amide compound, the effect of staying on the fixed image surface becomes very strong, and smear resistance is further improved.

  These release agents can be used alone or in combination of two or more. The amount of these release agents used is preferably 2 to 15% by weight based on the toner. If it is less than 2% by weight, the effect of preventing hot offset is insufficient, and if it exceeds 15% by weight, transferability and durability are deteriorated.

  The melting point of the release agent is preferably 70 to 150 ° C. When the temperature is lower than 70 ° C., the heat resistant storage stability of the toner is lowered. If it is higher than 150 ° C., the releasability cannot be sufficiently achieved.

As for the particle size of the toner of the present invention, the volume average particle size is preferably 4 to 10 μm in order to obtain a high image quality excellent in fine line reproducibility and the like.
If it is smaller than 4 μm, the cleaning property in the development process and the transfer efficiency in the transfer process are hindered, and the image quality is deteriorated. When it is larger than 10 μm, the fine line reproducibility of the image is lowered.
Here, the volume average particle diameter of the toner can be measured by various methods. In the present invention, Coulter Counter TAII manufactured by Coulter Electronics, USA is used.

  The toner of the present invention is preferably a pulverized toner produced by using a so-called pulverization method including at least a melt-kneading step in the production process because the peak ratio C / R can be controlled.

  In the pulverization method, a toner material containing at least a crystalline polyester resin (A), an amorphous resin (B), and a composite resin (C), and containing a colorant and a release agent as needed is dry-mixed and kneaded. This is a method of obtaining a pulverized toner by melt-kneading and pulverizing with a machine.

First, in the melt kneading step, the toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial continuous kneader, a biaxial continuous kneader, or a batch kneader using a roll mill can be used. Specific examples include KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay, PCM type twin screw extruder manufactured by Ikekai Iron Works, A Kneader manufactured by KK is preferably used.
The melt-kneading is preferably performed under appropriate conditions that do not cause the molecular chain of the binder resin (binder resin) to be broken. Specifically, the melt kneading temperature is determined with reference to the softening point of the binder resin, and if the temperature is too high, the cutting is severe, and if the temperature is too low, the dispersion may not proceed.

  In the pulverization step, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.

In the classification step, the pulverized product obtained in the pulverization step is classified and adjusted to particles having a predetermined particle size. Classification can be performed, for example, by removing fine particle portions by a cyclone, a decanter, centrifugation, or the like.
After the pulverization and classification are completed, the pulverized product is classified in an air current by centrifugal force or the like to produce a toner (toner base particle) having a predetermined particle size.

  The toner of the present invention is preferably a pulverized toner that undergoes a melt-kneading step in the production process. However, if the thickness of the kneaded product is 2.5 mm or more in the cooling step after the raw material is melt-kneaded, the toner is kneaded. The cooling rate of the product becomes slow, and the time for recrystallization of the crystalline polyester resin (A) melted in the kneaded product becomes long, so that recrystallization is promoted and the function of the crystalline polyester resin (A) Can be exhibited more effectively. In order to promote recrystallization, it is an effective means to add a fatty acid amide as described above, but the effect can also be obtained by adjusting the production process in this way. There is no upper limit to the thickness of the kneaded product, but if it is thicker than 8 mm, the efficiency is significantly reduced in the pulverization step, and the peak ratio C / R is increased, so it is preferable to keep the thickness at 8 mm or less.

  The kneaded product after the melt-kneading process is discharged as a lump as it is, and it takes a very excessive time for cooling, and the efficiency is remarkably lowered in the pulverizing process. Use a plate. In the present invention, the thickness of the kneaded material (such as a thin plate obtained by a rolling process) is 2.5 mm or more, so that it can be cooled gradually without being rapidly cooled. It is preferable because recrystallization of the resin (A) can be promoted.

  In order to enhance the fluidity, storage stability, developability, and transferability of the toner, inorganic fine particles such as hydrophobic silica fine powder may be further added to and mixed with the toner base particles produced as described above.

For mixing such additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the additive, for example, the additive may be added in the middle or gradually.
You may change suitably the rotation speed, rolling speed, time, temperature, etc. of a mixer. Further, a strong load may be applied first, and then a relatively weak load may be applied, or vice versa.
Examples of mixing equipment that can be used in the external additive mixing step include a V-type mixer, a rocking mixer, a Roedige mixer, a Nauter mixer, and a Henschel mixer.

  After performing the mixing step, coarse particles and aggregated particles may be removed by passing through a sieve of 250 mesh or more.

  When the toner of the present invention is used as a developer, it may be used as a one-component developer composed only of toner, or may be mixed with a carrier and used as a two-component developer. When used in a high-speed printer or the like corresponding to the recent improvement in information processing speed, it is preferably used as a two-component developer from the viewpoint of improving the service life.

1 shows an example of an electrophotographic developing apparatus according to the present invention.
7 to 9 are not included in the present invention, but are illustrated and described as a reference for explaining the present invention.

  6, reference numeral 101A denotes a driving roller, 101B denotes a driven roller, 102 denotes a photosensitive belt (image carrier), 103 denotes a charger (charging means), 104 denotes a laser writing system unit (exposure means), and 105A to 105D respectively. Developing units (developing means) for accommodating toners of yellow, magenta, cyan, and black, 106 is a paper feed cassette, 107 is an intermediate transfer belt, 107A is a driving shaft roller for driving the intermediate transfer belt, and 107B is an intermediate transfer belt. , A driven shaft roller (107, 107A, 107B, intermediate transfer means), 108 a cleaning device (cleaning means), 109 a fixing roller (fixing means), 109A a pressure roller (fixing means), 110 A paper discharge tray 113 is a paper transfer roller (transfer means).

  In this color image forming apparatus, a flexible intermediate transfer belt 107 is used, and the intermediate transfer belt 107 as an intermediate transfer member is stretched around a driving shaft roller 107A and a pair of driven shaft rollers 107B in a clockwise direction. The belt is circulated and the belt surface between the pair of driven shaft rollers 107B is in contact with the photosensitive belt 102 on the outer periphery of the driving roller 101A from the horizontal direction.

  During normal color image output, each color toner image formed on the photoreceptor belt 102 is transferred to the intermediate transfer belt 107 each time it is formed, and the color toner images are combined, and this is fed into the paper feed cassette 106. The transfer sheet is transferred onto the transfer sheet by the paper transfer roller 113, and the transferred transfer sheet is transferred between the fixing roller 109 and the pressure roller 109A of the fixing device, and is fixed by the fixing roller 109 and the pressure roller 109A. After fixing, the paper is discharged onto the paper discharge tray 110.

  When the developing units 105A to 105D develop the toner, the toner concentration of the developer stored in the developing unit decreases. A decrease in the toner density of the developer is detected by a toner density sensor (not shown). When a decrease in toner density is detected, a toner replenishing device (not shown) connected to each developing unit operates to replenish the toner and increase the toner density. At this time, the replenished toner may be a so-called trickle developing system developer in which a carrier and toner are mixed as long as the developing unit has a developer discharging mechanism.

  In FIG. 6, an image is formed by superimposing a toner image on the intermediate transfer belt. However, in the system for transferring directly from the image carrier to the recording medium without using the intermediate transfer belt, the electronic of the present invention is similarly applied. A photographic image forming apparatus can be obtained.

  FIG. 7 relates to a uniaxial circulation development system and is not included in the present invention, but is shown as a comparative example for explaining the present invention.

  In FIG. 7, a developing device 40, which is a developing means disposed opposite to the photoreceptor 20 which is a latent image carrier, includes a developing sleeve 41 as a developer carrier, a developer accommodating member 42, and a regulating member. It is mainly composed of a doctor blade 43, a support case 44 and the like.

  To a support case 44 having an opening on the side of the photoconductor 20, a toner hopper 45 serving as a toner storage unit that stores the toner 21 is joined. A developer containing portion 46 containing toner 21 and a carrier 23 adjacent to the toner hopper 45 is used to stir the toner 21 and the carrier 23 to impart friction / release charge to the toner 21. A developer stirring mechanism 47 is provided.

  Inside the toner hopper 45, a toner agitator 48 and a toner replenishing mechanism 49 are disposed as toner supplying means rotated by a driving means (not shown). The toner agitator 48 and the toner replenishing mechanism 49 send out the toner 21 in the toner hopper 45 toward the developer accommodating portion 46 while stirring.

  A developing sleeve 41 is disposed in a space between the photoconductor 20 and the toner hopper 45. The developing sleeve 41, which is rotationally driven in the direction of the arrow in the figure by a driving means (not shown), is disposed in the interior thereof so as to be in a relative position with respect to the developing device 40 in order to form a magnetic brush by the carrier 23. It has a magnet (not shown) as means.

  A doctor blade 43 is integrally attached to the developer accommodating member 42 on the side facing the side attached to the support case 44. In this example, the doctor blade 43 is disposed in a state where a certain gap is maintained between the tip of the doctor blade 43 and the outer peripheral surface of the developing sleeve 41.

  The image forming method of FIG. 7 is performed as follows. That is, with the above configuration, the toner 21 sent out from the inside of the toner hopper 45 by the toner agitator 48 and the toner replenishing mechanism 49 is conveyed to the developer accommodating portion 46 and agitated by the developer agitating mechanism 47, so The friction / peeling charge is applied, and is carried on the developing sleeve 41 as a developer together with the carrier 23 and conveyed to a position facing the outer peripheral surface of the photoconductor 20, and only the toner 21 is formed on the photoconductor 20. A toner image is formed on the photoreceptor 20 by electrostatically coupling with the electrostatic latent image.

  FIG. 8 is a diagram illustrating an example of an image forming apparatus having the developing device of FIG. Around the drum-shaped photoreceptor 20, a charging member 32, an image exposure system 33, a developing device 40, a transfer device 50, a cleaning device 60, and a charge removal lamp 70 are arranged. In the case of this example, the surface of the charging member 32 is in a non-contact state with a gap of about 0.2 mm from the surface of the photoconductor 20, and the charging member 32 is charged when the charging member 32 charges the photoconductor 20. The charging unevenness can be reduced by charging the photoconductor 20 with an electric field in which an AC component is superimposed on a DC component by a voltage applying means (not shown), which is effective. The image forming method including the developing method is performed by the following operation.

  A series of image forming processes can be described as a negative-positive process. A photoconductor 20 typified by a photoconductor (OPC) having an organic photoconductive layer is neutralized by a static elimination lamp 70 and is uniformly negatively charged by a charging member 32 such as a charging charger or a charging roller. A latent image is formed by laser light emitted from the image exposure system 33 (in this example, the absolute value of the exposed portion potential is lower than the absolute value of the non-exposed portion potential).

  Laser light is emitted from a semiconductor laser and scans the surface of the photoconductor 20 in the direction of the rotation axis of the photoconductor 20 by a polygonal polygonal mirror (polygon) that rotates at high speed. The latent image formed in this manner is developed with a developer composed of a mixture of toner and carrier supplied onto a developing sleeve 41 which is a developer carrying member in the developing device 40, and a toner image is formed. At the time of developing the latent image, a DC voltage having an appropriate magnitude or an AC voltage is superimposed on the developing sleeve 41 from a voltage application mechanism (not shown) between the exposed portion and the non-exposed portion of the photoreceptor 20. A development bias is applied.

  On the other hand, a transfer medium 80 (for example, paper) is fed from a paper feed mechanism (not shown), and is synchronized with the leading edge of the image by a pair of upper and lower registration rollers (not shown), and the photoconductor 20 and the transfer device 50. And the toner image is transferred. At this time, it is preferable that a potential having a polarity opposite to that of toner charging is applied to the transfer device 50 as a transfer bias. Thereafter, the transfer medium 80 is separated from the photoreceptor 20, and a transfer image is obtained.

Further, the toner remaining on the photoreceptor 20 is collected in a toner collecting chamber 62 in the cleaning device 60 by a cleaning blade 61 as a cleaning member.
The collected toner may be transported to the developer container 46 and / or the toner hopper 45 by a toner recycling means (not shown) and reused.
The image forming apparatus may be a device in which a plurality of the developing devices described above are arranged, the toner images are sequentially transferred onto a recording medium (transfer medium), and then sent to a fixing mechanism to fix the toner by heat or the like. An apparatus may be used in which a plurality of toner images are transferred onto an intermediate transfer medium, and the toner images are collectively transferred to a recording medium and then fixed in the same manner.

  FIG. 9 shows another example of the image forming apparatus. The photosensitive member 20 is provided with at least a photosensitive layer on a conductive support, and is driven by driving rollers 24a and 24b to be charged by a charging member 32, image exposure by an image exposure system 33, development and transfer by a developing device 40. Transfer using the apparatus 50, pre-cleaning exposure by the pre-cleaning exposure light source 26, cleaning by the brush-like cleaning means 64 and the cleaning blade 61, and static elimination by the static elimination lamp 70 are repeatedly performed. In FIG. 9, pre-cleaning exposure is performed on the photoconductor 20 (of course, in this case, the support is translucent) from the support side.

  Next, the configuration of the circulating developing device of the present invention will be described. 10 to 12 illustrate a developing system having a supply conveyance path, a recovery conveyance path, and a stirring conveyance path partitioned by a partition member. 10 to 12 are diagrams illustrating an example of the triaxial circulation development method, and FIGS. 13 to 15 are diagrams illustrating an example of the biaxial circulation development method.

FIG. 10 is an enlarged configuration diagram illustrating the developing device and the photosensitive member.
As shown in FIG. 10, the surface of the photoreceptor 1 is charged by a charging device (not shown) while rotating in the direction of arrow G in the drawing. The charged surface of the photoreceptor 1 is supplied with toner from the developing device 4 to a latent image on which an electrostatic latent image is formed by laser light emitted from an exposure device (not shown), thereby forming a toner image.

The developing device 4 has a developing roller 5 as a developer carrying member for supplying the developer to the latent image on the surface of the photoreceptor 1 while moving the surface in the direction of arrow I in the drawing. Further, a supply screw 8 is provided as a developer supply / conveying member that conveys the developer in the depth direction of FIG. 10 while supplying the developer to the developing roller 5.
A developing doctor 12 as a developer regulating member that regulates the developer supplied to the developing roller 5 to a thickness suitable for development is provided on the downstream side of the surface moving direction from the portion facing the supply screw 8 of the developing roller 5. ing.

  The developed developer that has passed through the developing unit is collected downstream from the developing unit, which is the part of the developing roller 5 facing the photoconductor 1, and the collected developer is collected in the same direction as the supply screw 8. A recovery screw 6 is provided as a developer recovery / conveying member that is transported to the surface. A supply conveyance path 9, which is a supply conveyance path provided with a supply screw 8, is provided in the lateral direction of the developing roller 5, and a collection conveyance path 7 as a collection conveyance path provided with a collection screw 6 is provided below the development roller 5. ing.

  The developing device 4 is provided with an agitation conveyance path 10 that is a developer agitation conveyance path in parallel with the recovery conveyance path 7 below the supply conveyance path 9. The agitating and conveying path 10 includes an agitating screw 11 as a developer agitating and conveying member that conveys the developer to the near side in the figure, which is in the opposite direction to the supply screw 8 while agitating the developer.

The supply conveyance path 9 and the stirring conveyance path 10 are partitioned by a first partition wall 133 as a partition member. In the first partition wall 133, the supply conveyance path 9 and the agitation conveyance path 10 are partitioned at both ends on the front side and the back side in the drawing, and the supply conveyance path 9 and the agitation conveyance path 10 communicate with each other. doing.
The supply conveyance path 9 and the recovery conveyance path 7 are both partitioned by the first partition wall 133, but an opening is provided at a location where the supply conveyance path 9 and the recovery conveyance path 7 of the first partition wall 133 are partitioned. Absent.

Further, the two conveyance paths of the stirring conveyance path 10 and the collection conveyance path 7 are partitioned by a second partition wall 134 as a partition member. The second partition wall 134 has an opening on the front side in the figure, and the agitation transport path 10 and the collection transport path 7 communicate with each other.
In the apparatus of this example, the supply screw 8, the recovery screw 6 and the agitation screw 11 which are developer conveying members are resin screws. For example, each screw diameter is φ18 mm, screw pitch is 25 mm, and rotation is performed. The number is about 600 rpm.

  The developer thinned by the developing doctor 12 made of stainless steel on the developing roller 5 is transported to a developing region which is a portion facing the photosensitive member 1 for development. The surface of the developing roller 5 is V-groove or sandblasted. As an example of the configuration, a φ25 mm Al (aluminum) tube is used, and the gap between the developing doctor 12 and the photosensitive member 1 is about 0.3 mm. Is mentioned.

  The developer after development is collected in the collection conveyance path 7 and conveyed to the front side of the cross section in FIG. 10, and to the agitation conveyance path 10 through the opening of the first partition wall 133 provided in the non-image area portion. Developer is transferred. In addition, toner is supplied to the stirring and conveying path 10 from a toner replenishing port provided on the upper side of the stirring and conveying path 10 in the vicinity of the opening of the first partition wall 133 on the upstream side in the developer conveying direction in the stirring and conveying path 10.

Next, the circulation of the developer in the three developer conveyance paths will be described.
FIG. 11 is a perspective sectional view of the developing device 4 for explaining the flow of the developer in the developer transport path. Each arrow in the figure indicates the moving direction of the developer.
FIG. 12 is a schematic diagram of the developer flow in the developing device 4. Like FIG. 11, each arrow in the drawing indicates the direction of movement of the developer.

  In the supply conveyance path 9 that has been supplied with the developer from the agitation conveyance path 10, the developer is conveyed downstream in the conveyance direction of the supply screw 8 while supplying the developer to the developing roller 5. Then, the excess developer that is supplied to the developing roller 5 and is not used for development and is transported to the downstream end in the transport direction of the supply transport path 9 is supplied to the stirring transport path 10 from the opening of the first partition wall 133 (FIG. 12). Middle arrow (E).

The collected developer that is sent from the developing roller 5 to the collection conveyance path 7 and conveyed to the downstream end in the conveyance direction of the collection conveyance path 7 by the collection screw 6 is supplied to the stirring conveyance path 10 from the opening of the second partition wall 134. (Arrow (F) in FIG. 12).
The agitating and conveying path 10 agitates the supplied surplus developer and the recovered developer, conveys them to the downstream side in the conveying direction of the agitating screw 11, and conveys them to the upstream side in the conveying direction of the supplying screw 8, and the first partition wall. It is supplied to the supply conveyance path 9 from the opening part 133 (arrow (D) in FIG. 12).

  In the agitating and conveying path 10, the agitating screw 11 agitates and conveys the collected developer, the surplus developer, and the toner replenished as necessary in the transfer unit in the direction opposite to the developer in the collecting and conveying path 7 and the supply conveying path 9. . Then, the agitated developer is transferred to the upstream side in the conveyance direction of the supply conveyance path 9 communicating with the downstream side in the conveyance direction. A toner concentration sensor (not shown) is provided below the agitation transport path 10, and a toner supply control device (not shown) is operated by the sensor output to supply toner from a toner container (not shown).

In the developing device 4 shown in FIG. 11, a supply conveyance path 9 and a recovery conveyance path 7 are provided, and developer supply and collection are performed in different developer conveyance paths, so that the developed developer is supplied to the supply conveyance path 9. There is no contamination. Accordingly, it is possible to prevent the toner density of the developer supplied to the developing roller 5 from decreasing toward the downstream side of the supply conveyance path 9 in the conveyance direction.
Further, since the recovery conveyance path 7 and the agitation conveyance path 10 are provided and the developer recovery and agitation are performed in different developer conveyance paths, the developed developer does not fall during the agitation. Therefore, since the sufficiently agitated developer is supplied to the supply conveyance path 9, it is possible to prevent the developer supplied to the supply conveyance path 9 from being insufficiently agitated.
In this way, the toner density of the developer in the supply conveyance path 9 can be prevented from decreasing, and the developer in the supply conveyance path 9 can be prevented from being insufficiently stirred. Can be constant.

FIG. 13 is a diagram showing the arrangement of the members around the photoreceptor 1 when the developing device 3 of the present invention is used in the image forming apparatus using the photoreceptor 1.
The developing device 3 includes a developer supply / conveying member 304 that stirs and conveys the developer 320 through the supply / conveying path, a developer stirring / conveying member 305 that stirs and conveys the developer 320 through the supply / conveying path, and a rotating member such as the developing roller 302. Other members are provided. The developing roller 302 has a length in the longitudinal direction substantially the same as the length of the photoreceptor 1.
The developing roller 302 is disposed close to the photosensitive member 1 so as to form the developing nip region A by facing the photosensitive member 1 in proximity. A portion of the casing 301 corresponding to the portion facing the photoconductor 1 is opened to expose the developing roller 302.
The developer 320 in the casing 301 is conveyed to the development nip region A by the developing roller 302. The toner in the developer 320 adheres to the electrostatic latent image formed on the surface of the photoreceptor 1 in the development nip region A, and is visualized as a toner image.

The developing device 3 includes a developing roller 302, a developer supply / conveying member 304, a developer agitating / conveying member 305, and a developer regulating member 303 inside the casing 301, and the developer 320 is agitated and conveyed to circulate.
A sleeve 302c positioned in a cylindrical shape around the developing roller is formed of a nonmagnetic metal such as aluminum. The magnet roller 302d is fixed to a stationary member such as the casing 301 so that each magnet faces a predetermined direction, and the circumference of the magnet roller 302d provided inside the developing roller rotates around the sleeve 302c. The developer 320 attracted by a plurality of magnets arranged in the direction is conveyed.
The developing roller 302 and the photosensitive member 1 are not in direct contact with each other in the developing nip region A but are opposed to each other while maintaining a developing gap GP1 at a constant interval suitable for development.

By developing the developer 320 on the developing roller 302 and bringing the developer 320 into contact with the photoreceptor 1, toner is attached to the electrostatic latent image on the surface of the photoreceptor 1 to be visualized.
In the developing device 3, a grounding bias power source (not shown) is connected to the fixed shaft 302a. The voltage of the power source connected to the fixed shaft 302a is applied to the sleeve 302c. On the other hand, the lowermost conductive support (not shown) constituting the photoreceptor 1 is grounded.

  Thus, an electric field for moving the toner separated from the carrier to the photosensitive member 1 side is formed in the developing nip region A, and the toner is generated by the potential difference between the sleeve 302c and the electrostatic latent image formed on the surface of the photosensitive member 1. Is moved toward the photosensitive member 1 side.

  Note that the developing device of this example is combined with an image forming apparatus of a writing method using light for exposure. The charging device 2 uniformly applies a negative charge on the photosensitive member 1 and exposes the character portion with exposure light to reduce the writing amount, thereby reducing the character portion (electrostatic latent image) having a reduced potential. ) Employs a so-called reversal development method in which development is performed with negative polarity toner. This is merely an example, and the polarity of the charged charge placed on the photoreceptor 1 is not a major problem in the developing method of the present invention.

After the development, the developed developer 320 carried on the developing roller 302 is conveyed downstream as the developing roller 302 rotates, and is drawn into the casing 301. A part of the casing 301 has a curved shape close to the peripheral surface of the sleeve 302c, and fulfills a so-called toner scattering prevention function by a sealing effect.
The drawn-in developer has an “agent separation” action that separates the developer 320 that has been drawn around the developing roller 302 from the developing roller 302, and has an agent separation region (indicated by reference numeral 9 in FIG. 13). It is formed.

  The developer 320 having the toner adhered to the photosensitive member 1 has a lower toner concentration in the developer. Therefore, the developer having the lowered toner concentration is conveyed again to the developing nip region A without leaving the developing roller 302. If supplied to the development, there arises a problem that a target image density cannot be obtained.

  In order to prevent this, in this example, the developer is separated from the developing roller 302 in the agent separation region 9 after development. Thereafter, the developer separated from the developing roller 302 is sufficiently agitated and mixed in the casing 301 so as to obtain a target toner concentration and toner charge amount.

In this way, the developer having the target toner concentration and charge amount is pumped up to the developing roller 302 in the agent pumping area (denoted by reference numeral 10 in FIG. 13) on the developing roller.
The so-called pumped-up developer attracted to the developing roller 302 passes through the developer regulating member 303, is adjusted to a predetermined thickness, and is conveyed to the developing nip region A while forming a magnetic brush.

  Hereinafter, as necessary, the arrangement of each member will be described with reference to FIG. 14 showing the internal configuration of the developing device in an assembled state, FIG. 15 showing the disassembled state, and the like. FIG. 14 is a schematic diagram showing the configuration of the developer supply / conveyance member and developer agitation / conveyance member of the developing device according to the present invention, and FIG. 15 shows the developer supply / conveyance member and developer of the development device according to the present invention. It is the schematic which shows the flow of the developer in a stirring conveyance member.

  As shown in FIG. 13, the developer supply / conveyance member 304 is disposed in the vicinity of the agent scooping region 10 at a position around the developing roller 302. This position is also on the upstream side of the developer regulating member 303. As shown in FIGS. 14 and 15, the developer supply / conveyance member 304 has a screw shape with a spiral around the rotation axis, and is parallel to a center line O-302 a passing through the center O-302 of the developing roller 302. The center line O-304a is rotated around the center line O-304a, and the developer is conveyed while stirring as indicated by an arrow 11 from the longitudinal direction rear side to the front side of the center line O-304a. That is, the developer supply transport member 304 transports the developer in the axial direction by the rotation of the rotation shaft.

  The developer agitating / conveying member 305 is disposed in the vicinity of the agent separating area 9 at a position around the developing roller 302. As shown in FIG. 14, the developer agitating / conveying member 305 has a screw shape with a spiral around the rotation axis, and a center line parallel to the center line O-302 a passing through the center O-302 of the developing roller 302. The developer rotates with O-305a as the center, and conveys the developer while stirring as indicated by an arrow 12 from the front side in the longitudinal direction of the center line O-305a to the back side. That is, the developer agitating / conveying member 305 conveys the developer in the direction opposite to the conveying direction by the developer supply / conveying member 304 by the rotation of the rotation shaft.

The developer stirring / conveying member 305 is preferably positioned obliquely above the developer supply / conveying member 304, and the space around the developer supply / conveying member 304 and the developer stirring / conveying member 305 in the casing 301. Adjacent to the surrounding space.
The rear end portions of the developer supply / conveying member 304 and the developer agitating / conveying member 305 are set so as to be located slightly behind the rear end portion of the developing roller 302, and the rear end portions of the developing roller 302 are arranged. The supply of developer is secured. Further, the front end portions of the developer supply transport member 304 and the developer agitation transport member 305 are positioned in front of the front end portion of the developing roller 302 so as to secure a space for toner replenishment described later. ing. The developer regulating member 303 is installed according to the length of the developing roller 302.

  Between the developer supply / conveying member 304 and the developer agitating / conveying member 305, in the central portion excluding both ends in the longitudinal direction of the developing roller 302, the space around the developer supply / conveying member 304 and the periphery of the developer agitating / conveying member 305 A partition plate 306 is formed in a cantilevered manner integrally with the inner wall of the casing 301 on the side away from the developing roller 302.

The partition plate 306 is located at the center of the developing roller 302 except for both ends in the longitudinal direction, and is not located at a portion corresponding to both ends in the longitudinal direction of the developing roller 302. On the other hand, the longitudinal ends of the developer supply / conveyance member 304 and the developer agitation / conveyance member 305 extend to both longitudinal ends of the developing roller 302.
The developer conveyed in the direction of the arrow 12 by the developer agitating / conveying member 305 is cut off at the end of the conveyance direction at the side wall of the casing 301 and moves to the supply conveyance path along the side wall. The developer supply / conveyance member 304 moves the supply / conveyance path.
Similarly, the developer transported in the direction of the arrow 11 by the developer supply transport member 304 moves along the side wall in order to cut off the path at the side wall of the casing 301 at the end in the transport direction. Then, the developer agitating and conveying member 305 moves the agitating and conveying path.

The partition plate 306 is positioned at the center of the developing roller 302 except for both ends in the longitudinal direction, so that the developer flows in the direction of the arrows 13 and 14 at the ends in the longitudinal direction. In order to form a circulation conveyance path along the arrows 11, 14, 12, and 13 as a whole.
In the illustrated example, the partition plate 306 has an opening 307 in the vicinity of the end on the back side, and the developer is moved from the stirring conveyance path to the supply conveyance path through the opening 307. Therefore, the partition plate 306 can be extended to the end in the longitudinal direction of the developing roller 302.

  Thus, the developing device 3 of the present invention includes (i) a developing roller 302 that carries and rotates the developer and visualizes the electrostatic latent image formed on the photosensitive member 1, and (ii) the developing roller 302. The developer is pumped up in the vicinity of the agent pumping area 10 and rotates around a center line O-304a parallel to the center line O-302a of the developing roller 302, and the developer in the longitudinal direction of the center line O-304a. And (iii) a center line 305a parallel to the center line 302a of the developing roller 302, which is disposed in the vicinity of the developer separating area 9 for separating the developer from the developing roller 302. A developer agitating and conveying member 305 that conveys the developer in a direction opposite to the direction in which the developer supplying and conveying member 304 conveys the developer, and (iv) a developer supplying and conveying member 304 Developer stirrer In this configuration, between the agitating and conveying member 305, the partition plate 306 that shields the supply conveying path and the agitating and conveying path in the developing device 3, that is, in the central portion excluding both ends of the casing and the developing roller 302 in the longitudinal direction, Have. With this configuration, two developer supplying / conveying members 304 and developer agitating / conveying members 305 in 301 that form a circulation conveying path along arrows 11, 14, 12, and 13 are arranged side by side on the developing roller 302. Therefore, the horizontal (horizontal) size of the developing device can be reduced as compared with the technique shown in FIG. 11 in which two developer agitating / conveying members are arranged in a direction away from the developing roller (in the horizontal direction). .

  Further, in this way, in the developing device 3 designed to be compact in the horizontal direction, the periphery of the developer supply / conveyance member 304 and the periphery of the developer agitating / conveyance member 305 at the central portion excluding both ends in the longitudinal direction of the developing roller 302 by the partition plate 306. Therefore, only the developer 320 in which the toner and the carrier are sufficiently stirred and mixed is supplied to the developing roller 302 by the developer supply / conveying member 304, and the toner density immediately after the development is lowered. The developer is merely agitated and conveyed by the developer agitating / conveying member 305, and is not immediately supplied to the developing roller 320. Therefore, only the toner having a target charge amount is used for the developing roller 320 for development. As a result, high image quality can be obtained.

  The partition plate 306 supports the developer 320 that is agitated and transported by the developer supply transport member 304 to form a developer transport path, and is separated from the developing roller 302 at the upstream side of the partition plate 306 in the agent separation region 9 and developed. The developer stirred and conveyed by the agent stirring and conveying member 305 is attracted again to the developing roller 302 and is prevented from moving to the space stirred by the developer supply and conveying member 304.

  In order to make this function more reliable, it is preferable to maintain the gap between the outer peripheral portion of the developing roller 302 and the partition plate 306 and the partition plate gap GP2 in a gap of about 0.2 to 1 mm. If it is less than 0.2 mm, the partition plate 306 may collide with the developing roller due to eccentricity when the developing roller 302 rotates, and if it exceeds 1 mm, the trimming performance becomes incomplete. Thereby, a sufficient function can be obtained even when the setting position of the partition plate 306 is set to an arbitrary position in the agent separation region 9. That is, the degree of freedom of the partition plate setting position increases.

Furthermore, it is possible to obtain a function as a partition plate even if the arrangement is shifted from the agent separation region 9. However, when the arrangement is shifted from the agent separation area 9, there is a possibility that the partition plate restricts a large amount of developer, which is not preferable because the stress received by the developer becomes large.
In that case, the agent separation region 9 is located around the development roller 302 opposite to the photoreceptor 1 with the developing roller 302 in between, and the agent is adjacent to the downstream side of the agent separation region 9 in the rotation direction of the development roller. The pumping area 10 is located, and the space between the supply transport path and the agitation transport are located between the agent separation area 9 and the agent pumping area 10 at a position where the amount of developer adhering around the developing roller 302 is the smallest. It is preferable that the partition plate 306 is provided so as to shield the space of the road, and the end of the partition plate 306 on the developing roller 302 side is opposed to the developing roller 302.

  With such a configuration, even if the partition plate gap GP2 is not set to 0.2 to 1 mm, the position where the developer adheres to the periphery of the developing roller 302 is the smallest at the portion where the partition plate is provided. Therefore, the function of the partition plate 306 can be exhibited. Further, the stress applied to the developer can be minimized by being regulated by the partition plate. That is, gap management at the time of setting the partition plate can be relaxed. However, if the configuration is further added with the condition that the partition plate gap GP2 is set to 0.2 to 1 mm, the stress applied to the developer can be further reduced.

  As shown in FIGS. 14 and 15, the developer agitating / conveying member 305 conveys the developer 320 separated from the developing roller 302 to the back side of the developing device in the direction of the arrow 12 while agitating. As shown in FIGS. 14 and 15, an opening 307 is provided in a part of the partition plate 306 at the downstream side in the transport direction of the developer stirring transport path and at the back end of the developing device, and the developer stirring transport member 305. The developer 320 transported in this way moves in the direction of the opening 307 along the arrow to the supply transport path.

As shown in FIG. 15, in the downstream portion in the developer conveyance direction by the developer stirring and conveying member 305, an impeller 308 may be configured instead of the screw portion in a range corresponding to the opening 307.
This impeller 308 has a configuration in which a plurality of blade-like members extending in a plate shape in the normal direction from the axis (center line O-305a) is provided for the shaft portion 305J of the developer agitating and conveying member 305. Along with this, the developer 320 has a function of jumping.

  The center O-304 of the developer supply / conveyance member 304 and the center O-305 of the developer agitation / conveyance member 305 are substantially on the same vertical line, and the developer is moved along the inner wall of the casing 301 as the impeller 308 rotates. Bounce 320. The opening 307 is formed so as to extend from a position slightly closer to the inner wall of the casing to a position closer to the inner wall of the casing than a substantially vertical line connecting the centers O-304 and O-305 so as not to hinder the path of the developer due to the splash. preferable.

  The rotation direction of the developer supply / conveyance member 304 is preferably opposite to the development roller 302. In general, since the screw has an action of moving the conveyed object in the axial direction and moving it in the rotational direction, the developer supply / conveying member 304 conveys the developer 320 while approaching the developing roller 302 in the supply / conveyance path. . Accordingly, continuous developer supply to the developing roller 302 becomes possible.

  When the developer stirring and conveying member 305 is rotated in the same direction as the developing roller 302, the developer 320 is conveyed while being moved away from the developing roller 302. The developer once separated from the developing roller 302 by 306 or the like is prevented from adhering to the developing roller 302 again. Therefore, it is possible to prevent the developer having a lowered toner density after development from being transported to the region of the developer supply transport member 304.

  Since the developer 320 in the developing device 3 consumes toner while repeating the developing operation, it is necessary to supply toner to the developer in the device from the outside of the developing device. From the upstream end of the agitation transport path disposed in the vicinity of the agent separation area 9 where the developer 320 is separated from the developing roller 302, that is, from the developer replenishment section provided near the end on the near side of the developing device, etc. When the toner is replenished, the replenished toner is not immediately used for development, but is agitated by the developer agitating / conveying member 305 and is subjected to development at a stable predetermined toner concentration.

  The agitating / conveying path only collects the developer 320 away from the developing roller 302, and does not supply toner to the developing roller 302. A developer that is not stirred and has a non-uniform toner concentration is not subjected to development.

  The replenishment toner is transported to the back side of the developing device 3 while being agitated and mixed with the developer 320 having a lowered toner density, which is away from the developing roller 302. Until then, the toner density is normalized, and is supplied to the developing roller 302 and used for development while being conveyed to the near side by the developer supply conveying member 304.

  In the developing device 3 according to this example, the developer 320 transported by the developer supply transport member 304 is pumped up to the developing roller 302 while being transported toward the front side. The developer 320 pumped up by the developing roller 302 is brought into contact with the photosensitive member 1 via the magnetic brush and used for development, and then separated from the developing roller 302 in the agent separating area 9 in the developing device 3. It is conveyed toward the back side by the agitating and conveying member 305.

  Such a developer circulation path is as described with reference to arrows 11, 14, 12, and 13 in FIGS. 14 and 15, and is used for development before being transported to the near side by the developer supply transport member 304. For this reason, the developer returned to the back side by the developer stirring and conveying member 305 increases, and the developer 320 tends to accumulate on the back side. If this is left unattended, smooth circulation of the agent may be hindered.

  This is because the developer supply and conveyance member 304 has a developer conveyance capacity larger than that of the developer agitation and conveyance member 305, so that the developer conveyance amount per unit time by the developer supply and conveyance member 304 is reduced to the developer agitation and conveyance member 305. This can be solved by making the developer transport amount per unit time larger than the above and balancing the transport of the developer in the depth direction. Thereby, smooth circulation of the developer can be maintained over a long period of time.

  The developer conveying ability of the developer agitating and conveying member 305 can be increased by increasing the outer diameter of the screw of the developer supplying and conveying member 304 with respect to the developer agitating and conveying member 305. The same benefits can be obtained by increasing the spiral pitch of the screw of the developer supply / conveyance member 304, increasing the number of rotations, and increasing the space of the developer supply path by the developer supply / conveyance member 304. be able to.

  FIG. 16 shows an example of the process cartridge of the present invention. This process cartridge uses the developer containing the toner of the present invention, the photosensitive member 20, the proximity brush-like charging means 32, the developing means 40 for storing the developer containing the toner of the present invention, and the cleaning means. This is a process cartridge that integrally supports at least a cleaning unit having the cleaning blade 61 and is detachable from the main body of the image forming apparatus. In the present invention, the above-described components can be integrally combined as a process cartridge, and the process cartridge can be configured to be detachable from a main body of an image forming apparatus such as a copying machine or a printer.

  Hereinafter, the present invention will be described with reference to examples and comparative examples. In addition, this invention is not limited to the Example illustrated here. In the following, “parts” represents parts by weight.

Example 1
[Preparation of pulverized toner]
<Preparation of pulverized toner 1>
Crystalline polyester resin: a-1 4 parts by weight Amorphous resin: b1-1 35 parts by weight Amorphous resin: b2-1 55 parts by weight Composite resin: c-1 10 parts by weight Colorant: p-1 14 parts by weight Part Release agent: Carnauba wax (melting point: 81 ° C.) 6 parts by weight Charge control agent: 2 parts by weight of monoazo metal complex (chromium complex salt dye (Bontron S-34, manufactured by Orient Chemical Co., Ltd.)

  After premixing the raw materials shown in Tables 1 to 5 below and the toner raw materials by the release agent and the charge control agent using a Henschel mixer (FM20B, manufactured by Mitsui Miike Chemical Co., Ltd.) according to the above prescription The mixture was melted and kneaded at a temperature of 100 to 130 ° C. with a twin-screw kneader (Ikegai Co., Ltd., PCM-30). The obtained kneaded material was rolled to a thickness of 2.7 mm with a roller, cooled to room temperature with a belt cooler, and coarsely pulverized to 200 to 300 μm with a hammer mill. Next, the mixture was finely pulverized using a supersonic jet crusher lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), and then the weight average particle diameter was 6. by an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). Classification was performed while appropriately adjusting the louver opening so as to be 9 ± 0.2 μm to obtain toner base particles. Next, 1.0 part by weight of an additive (HDK-2000, manufactured by Clariant Co., Ltd.) was stirred and mixed with a Henschel mixer with respect to 100 parts by mass of the toner base particles, whereby a pulverized toner 1 was produced.

  Table 7 shows the molecular weight main peak, half-value width of the molecular weight distribution, DSC peak temperature / endothermic amount and volume average particle diameter in the range of 90 to 130 ° C. attributable to the crystalline polyester resin (A).

  The pulverized toner developer 1 was prepared by uniformly mixing 5% by mass of the pulverized toner 1 and 95% by mass of the coated ferrite carrier with a tumbler mixer (manufactured by Willy et Bacchofen (WAB)) for 5 minutes at 48 rpm. Was made.

  The developer 1 was evaluated by the triaxial circulation development developer shown in FIG. 10 as Example 1-1, and the developer 1 was evaluated by the biaxial circulation development developer shown in FIG. What was performed was made into Example 1-2. Further, Comparative Example 0 was evaluated for the developer 1 using the developing machine shown in FIG.

(Examples 2 to 30, Comparative Examples 1 to 8)
Hereinafter, the raw materials described in Tables 1 to 5 below, the release agent described in Table 6, the charge control agent, the rolling thickness, and depending on the production examples, fatty acid amides in parts by weight described in Table 6 were used in Example 1. In the same manner as above, mixing, kneading, pulverization, and additive mixing were performed to prepare toners 2-38, and a developer was prepared.

However, in the toner 34, since the dispersion of the pigment in the resin is poor, before mixing with other raw materials, preliminary mixing is performed using the amorphous resin b2-3 and pure water to form a master batch. Thus, a toner using the colorant p-2 was prepared. In forming the toner, the amount of the amorphous resin b2-3 contained in the masterbatch was calculated backward, and the final raw material ratio was adjusted to the amount shown in Table 6. Each developer was evaluated with a triaxial developing machine shown in FIG.
In Comparative Example 1, what was evaluated with the triaxial developing developer shown in FIG. 10 was evaluated with Comparative Example 1-1, and the biaxial circulating developing developer shown in FIG. Was evaluated in Comparative Example 1-2 and the developing machine shown in FIG. (See the developer configuration in Table 8 below)

<Preparation of master batch of pulverized toner 31>
Non-crystalline resin: b2-3 100 parts by weight Colorant: p-2 50 parts by weight Pure water 50 parts by weight

Of course, in the present invention, the method for producing the masterbatch is not limited to the above.
In addition, the metal complex (Bontron E-84 Orient Chemical Industry Co., Ltd.) which is a salicylic acid zinc compound was used for the salicylic acid metal compound of the charge control agent used in Examples 37 to 39.
Table 1 shows the glass transition temperature Tg and softening temperature of the crystalline polyester resins a-1 to a-6.

The crystalline polyester resins a-1 to a-6 include a compound selected from 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol as an alcohol component, and fumaric acid as a carboxylic acid component. , A resin obtained using a compound selected from succinic acid, trimellitic acid and terephthalic acid.
The crystalline polyester resins a-1 to a-6 have at least one diffraction peak at a position of 2θ = 19 ° to 25 ° in the X-ray diffraction pattern by the powder X-ray diffractometer. It was confirmed that. The X-ray diffraction result of the crystalline polyester resin a-6 is shown in FIG.
Next, Tables 2 to 4 show the compositions and evaluations of the amorphous resins b1-1 to b1-6, b2-1 to b2-3, the composite resins c-1 and c-2.

The non-crystalline resins b1-1 to b1-6, b2-1 to b2-3 and the composite resins c-1 and c-2 are resins obtained as follows.
A monomer selected from an aromatic diol component, ethylene glycol, glycerin, adipic acid, terephthalic acid, isophthalic acid and itaconic acid is subjected to an esterification reaction under normal pressure at 170 to 260 ° C. under non-catalytic conditions. 400 ppm of antimony trioxide was added to the total carboxylic acid component in the reaction system, and polycondensation was carried out at 250 ° C. while removing glycol out of the system under a vacuum of 3 Torr to obtain a resin. The crosslinking reaction was carried out until the stirring torque reached 10 kg · cm (100 ppm), and the reaction was stopped by releasing the reduced pressure state of the reaction system.

  The non-crystalline resins b1-1 to b1-6, b2-1 to b2-3 and the composite resins c-1 and c-2 are non-crystalline due to the absence of diffraction peaks due to the X-ray diffraction pattern. It was confirmed.

Composite resin c-1: softening temperature 115 ° C., glass transition temperature 58 ° C., acid value 25 mgKOH / g
Polycondensation monomers: terephthalic acid, fumaric acid, trimetic anhydride, bisphenol A (2,2) propylene oxide, bisphenol A (2,2) ethylene oxide Addition polymerization monomers: styrene, acrylic acid, 2-ethylhexyl acrylate composite resin c-2:
Polycondensation monomer: hexamethylenediamine, ε-caprolactam addition polymerization monomer: styrene, acrylic acid, 2-ethylhexyl acrylate Next, Table 5 shows the colorants used in Examples and Comparative Examples, and Table 6 shows the raw material ratios. Table 7 shows the measurement results.

  The pulverized toner developers 1 to 38 were accommodated by modifying the development unit 105D portion of FIG. The developing units 105A to 105C were not used.

<Low temperature fixability, hot offset resistance, fine line reproducibility (initial)>
Using the image forming apparatus, an image of the pulverized toner developers 1 to 38 was output. A solid image having an adhesion amount of 0.4 mg / cm ² was output on paper (Type 6200 manufactured by Ricoh) through the exposure, development, and transfer processes. The linear speed of fixing was 180 mm / second. The fixing temperature was sequentially output in increments of 5 ° C., and the lower limit temperature at which no cold offset occurred (fixing lower limit temperature: low temperature fixability) and the upper limit temperature at which hot offset did not occur (fixing upper limit temperature: hot offset resistance) were measured. The NIP width of the fixing device was 11 mm. Separately, a character chart (image size of about 2 mm × 2 mm) with an image area ratio of 5% by pulverized toner is output at a fixing lower limit temperature + 20 ° C., and fine lines are reproduced by visual judgment. The sex was evaluated.

◆ Low-temperature fixability evaluation criteria ◎: Less than 130 ° C ○: 130 ° C or more and less than 140 ° C □: 140 ° C or more and less than 150 ° C △: 150 ° C or more and less than 160 ° C ×: 160 ° C or more

◆ Hot offset resistance evaluation criteria ◎: 200 ° C or higher ○: 190 ° C or higher and lower than 200 ° C □: 180 ° C or higher and lower than 190 ° C △: 170 ° C or higher and lower than 180 ° C ×: Less than 170 ° C

◆ Thin line reproducibility evaluation criteria ◎: Very good ○: Good □: General level △: No problem in practical use ×: Unacceptable

<Smear resistance>
At the minimum fixing temperature, a halftone image with a toner coverage of 0.40 ± 0.1 mg / cm ² and an image area ratio of 60% is output on paper (Ricoh Type 6200 paper), and the fixed image portion is clocked. Using a meter, rubbing with a white cotton cloth (JIS L0803 cotton No. 3) 10 times, and the ID of dirt adhering to the cloth (hereinafter referred to as smear ID) was measured. The smear ID was measured with a colorimeter (X-Rite 938). The pulverized toner 31 was measured with cyan, and the other toners were measured with black.

◆ Smear resistance evaluation criteria ◎: Smear ID is 0.20 or less ○: Smear ID is greater than 0.20 and less than or equal to 0.35 Δ: Smear ID is greater than 0.35 and less than or equal to 0.55 ×: Smear ID is 0. Greater than 55

<Reproducibility of fine lines (over time)>
After evaluating the initial fine line reproducibility, a chart with an image area ratio of 5% was continuously output while replenishing the toner, and 100k sheets were output continuously, and then the image area ratio with the pulverized toner was again fixed at the fixing temperature of fixing lower limit temperature + 20 ° C. A 5% character chart (the size of one character is about 2 mm × 2 mm) is output, and visual judgment is performed to evaluate reproducibility of fine lines over time. The criterion was the same as the initial thin line reproducibility evaluation.

<Heat resistant storage stability>
10 g of each toner is put into a 30 ml screw vial, tapped 100 times with a tapping machine, stored in a constant temperature bath at 50 ° C. for 24 hours, returned to room temperature, and then penetrated with a penetration testing machine. It measured and it was set as the heat-resistant preservation | save evaluation.

◆ Evaluation criteria for heat resistant storage stability ◎: Penetrating ○: 20 mm or more □: 15 mm or more and less than 20 mm △: 10 mm or more and less than 15 mm ×: Less than 10 mm

<Chargeability after low printing rate run>
Using the image forming apparatus described in each condition, a character chart (the size of one character is about 2 mm × 2 mm) with an image area ratio of 2% for each toner is output at the fixing temperature of each toner at a fixing temperature of + 20 ° C. did. While supplying toner, 100 k sheets were continuously output, and the charge amount of the developer was measured.

◆ Evaluation criteria for low printing rate after run ◎: 21μC / g or more ○: 18 or more and less than 21μC / g △: 15 or more and less than 18μC / g ×: Less than 15μC / g

<Density unevenness>
After the above-described fine reproducibility (aging) evaluation, three solid images were continuously output, and the density unevenness of the output image was visually evaluated for rank.

◆ Density unevenness evaluation standard ◎: State in which no unevenness exists on the image ○: State in which density unevenness at a level that does not cause a problem is slightly observed Δ: State in which density unevenness at a level that does not cause a problem is observed ×: When the density unevenness is very noticeable outside the allowable range

  The results of each evaluation are shown in Table 8.

  As described above, according to the present invention, it is possible to form a high-quality image even in the long term by combining extremely excellent low-temperature fixability, high hot offset resistance, and good storage stability. It has been found that an image forming method can be provided.

(About Figure 6)
DESCRIPTION OF SYMBOLS 101A Drive roller 101B Follower roller 102 Photosensitive belt 103 Charger 104 Laser writing system unit 105A, 105B, 105C, 105D Developing unit for storing toner of each color of yellow, magenta, cyan, and black 106 Paper feed cassette 107 Intermediate transfer belt 107A Drive shaft roller for driving the intermediate transfer belt 107B Driven shaft roller for supporting the intermediate transfer belt 108 Cleaning device 109 Fixing roller 109A Pressure roller 110 Paper discharge tray 113 Paper transfer roller (about FIG. 7)
DESCRIPTION OF SYMBOLS 20 Photoconductor 21 Toner 23 Carrier 41 Developing sleeve 42 Developer accommodating member 43 Developer supply regulating member 44 Support case 45 Toner hopper 46 Developer accommodating portion 47 Developer agitating mechanism 48 Toner agitator 49 Toner replenishing mechanism (FIG. 8)
DESCRIPTION OF SYMBOLS 20 Photoconductor 32 Charging member 33 Image exposure system 40 Developing device 41 Developing sleeve 45 Toner hopper 47 Developer stirring mechanism 50 Transfer device 60 Cleaning device 61 Cleaning blade 62 Toner recovery chamber 70 Static elimination lamp 80 Transfer medium (about FIG. 9)
DESCRIPTION OF SYMBOLS 20 Photoconductor 24a Drive roller 24b Drive roller 26 Exposure light source before cleaning 32 Charging member 33 Image exposure system 40 Developing device 50 Transfer device 61 Cleaning blade 64 Brush-like cleaning means 70 Static elimination lamp (about FIGS. 10-12)
DESCRIPTION OF SYMBOLS 1 Photoconductor 4 Developing apparatus 5 Developing roller 6 Collection screw 7 Collection conveyance path 8 Supply screw 9 Supply conveyance path 10 Stirring conveyance path 11 Stirring screw 12 Developing doctor 133 First partition wall 134 Second partition wall (FIGS. 13 to 15) )
DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Developing device 9 Agent separation area 10 Agent pumping area 11, 12, 13, 14 Developer circulation path 301 Casing 302 Developing roller 302a Fixed shaft 302c Sleeve 302d Magnet roller 303 Developer regulating member 304 Developer supply Conveying member 305 Developer stirring and conveying member 305J Shaft 306 Partition plate 307 Opening 308 Impeller 310 Replenishment opening 320 Developer O-302 center O-302a, O-304a, O-305a Center line A Development nip area A
GP1 Development gap GP2 Partition gap (About Fig. 16)
20 Photosensitive member 32 Charging unit 40 Developing unit 61 Cleaning unit

JP 60-90344 A JP-A 64-15755 Japanese Patent Laid-Open No. 2-82267 JP-A-3-229264 JP-A-3-41470 JP-A-11-305486 JP 62-63940 A Japanese Patent No. 2931899 JP 2001-222138 A JP 2004-46095 A JP 2007-33773 A JP 2005-338814 A Japanese Patent No. 4118498 JP 2007-206097 A

Claims (13)

A two-component developer composed of an electrophotographic image forming toner and a magnetic carrier is conveyed and supplied to a developer carrier, and the developer is carried on the surface to form a latent image formed on the latent image carrier. An image forming method having a developing means for supplying toner and developing,
The electrophotographic image forming toner includes a crystalline polyester resin (A), an amorphous resin (B), and a composite resin (C) including a condensation polymerization resin unit and an addition polymerization resin unit, Derived from the crystalline polyester resin (A), which contains chloroform insoluble matter and is measured by a total reflection method using a Fourier transform infrared spectroscopic measurement apparatus after being stored in a constant temperature bath at 45 ° C. for 12 hours. The peak height ratio (C / R) is 0, where C is the peak height of the characteristic spectrum and R is the peak height of the characteristic spectrum derived from the amorphous resin (B). 0.03 to 0.55,
The THF soluble content of the electrophotographic image forming toner has a main peak with a molecular weight distribution by GPC between 1000 and 10,000, and the half width of the main peak is 15000 or less,
The developing means has a supply conveyance path and a recovery stirring conveyance path,
The supply conveyance path conveys and supplies the developer to the developer carrying member,
The recovery agitation transport path transports the excess developer transported to the most downstream side in the transport direction of the supply transport path and the developer recovered after development while being stirred without being used for development, and a supply transport path To supply
The image forming method, wherein the supply conveyance path and the recovery agitation conveyance path have structures that are independent from each other at least in a portion excluding both ends in the longitudinal direction. The recovery agitation conveyance path is a collection conveyance path for agitating and conveying the developer collected after development, and the excess developer conveyed to the most downstream side in the conveyance direction of the supply conveyance path without being used for development and after development A stirring conveyance path for conveying the collected developer while stirring,
The image forming method according to claim 1, wherein the recovery conveyance path and the agitation conveyance path have a structure independent from each other at least in a portion excluding both ends in the longitudinal direction.   The image forming method according to claim 1, wherein the toner contains 1 to 30% by weight of a chloroform-insoluble component.   The endothermic peak of the toner has an endothermic peak in a range of 90 to 130 ° C in an endothermic peak measurement by a suggestive scanning calorimeter, and the endothermic amount of the endothermic peak is 1 to 15 J / g. 4. The image forming method according to any one of 3 above. The amorphous resin (B) contains two types of an amorphous resin (B-1) and an amorphous resin (B-2),
The image forming method according to claim 1, wherein the amorphous resin (B-1) contains a chloroform-insoluble component. The amorphous resin (B) contains two types of an amorphous resin (B-1) and an amorphous resin (B-2),
The softening temperature (T1 / 2) of the non-crystalline resin (B-1) is 25 ° C. or more higher than that of the non-crystalline resin (B-2). Image forming method.   The image forming method according to claim 5, wherein the non-crystalline resin (B-1) contains 5 to 40% of chloroform insoluble matter.   The non-crystalline resin (B-2) has a main peak having a molecular weight distribution by GPC determined by THF-soluble content of 1000 to 10,000, and the half width of the main peak is 15000 or less. The image forming method according to claim 5, wherein the image forming method is an image forming method.   The image forming method according to claim 1, wherein the toner contains a fatty acid amide compound. The image forming method according to claim 1, wherein the crystalline polyester resin (A) contains an ester bond represented by the following general formula (1) in a molecular main chain.
_{[-OCO-R-COO- (CH} 2) n -] ··· formula (1)
(In general formula (1), R represents a C2-C20 linear unsaturated aliphatic divalent carboxylic acid residue, and n represents an integer of 2-20.)   The image according to any one of claims 1 to 10, wherein the composite resin (C) is a composite resin having a polyester condensation polymerization resin unit and a vinyl resin addition polymerization unit. Forming method.   2. An image carrier and a developing means for making an electrostatic latent image formed on the image carrier a visible image with a developer containing toner for electrophotographic image formation and a carrier are integrally supported. A process cartridge which is detachably provided in an image forming apparatus main body which forms an image using the image forming method according to any one of claims 11 to 11. A two-component developer composed of an electrophotographic image forming toner and a magnetic carrier is conveyed and supplied to a developer carrier, and the developer is carried on the surface to form a latent image formed on the latent image carrier. An image forming apparatus having a developing unit that supplies toner and performs development,
The electrophotographic image forming toner includes a crystalline polyester resin (A), an amorphous resin (B), and a composite resin (C) including a condensation polymerization resin unit and an addition polymerization resin unit, Derived from the crystalline polyester resin (A), which contains chloroform insoluble matter and is measured by a total reflection method using a Fourier transform infrared spectroscopic measurement apparatus after being stored in a constant temperature bath at 45 ° C. for 12 hours. The peak height ratio (C / R) is 0, where C is the peak height of the characteristic spectrum and R is the peak height of the characteristic spectrum derived from the amorphous resin (B). 0.03 to 0.55,
The THF soluble content of the electrophotographic image forming toner has a main peak with a molecular weight distribution by GPC between 1000 and 10,000, and the half width of the main peak is 15000 or less,
The developing means has a supply conveyance path and a recovery stirring conveyance path,
The supply conveyance path conveys and supplies the developer to the developer carrying member,
The recovery agitation transport path transports the excess developer transported to the most downstream side in the transport direction of the supply transport path and the developer recovered after development while being stirred without being used for development, and a supply transport path To supply
The image forming apparatus, wherein the supply conveyance path and the recovery agitation conveyance path have a structure independent from each other at least in a portion excluding both ends in the longitudinal direction.