JP2003207932A - Toner, image forming method, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner by which a high definition image can be obtained without generating fine discontinuous stripes in spite of long-term usage. <P>SOLUTION: The toner of the present invention is the one for forming the image by using a nonmagnetic one-component developing system. The toner is adopted in an image forming method which includes at least a toner layer forming process for abutting a toner restricting member onto the front surface of a toner carrier body and restricting a toner layer on the toner carrier body and a developing process for bringing the toner layer carried on the surface of the toner carrier body into contact with the front surface of an electrostatic latent image carrier body and, then, developing an electrostatic latent image to form the toner image onto the electrostatic latent image carrier body. The toner restricting member is provided with universal hardness of ≥9.5 N/mm<SP>2</SP>and <100 N/mm<SP>2</SP>. The toner contains at least a colorant and a binding resin and has average particle diameter of ≥4 μm and <12 μm. At least silica fine powder is provided on the front surface of each toner particle and also inorganic fine powder A with a particle diameter being larger than the primary particle diameter of the silica fine powder is provided on the front surface of the toner particle. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic charge image used in an electrostatic copying machine, a laser printer, etc., and an image forming method and a process cartridge using the toner. Is.

[0002]

2. Description of the Related Art In recent years, with the spread of copying machines and printers using electrophotography, further speeding up, downsizing, full color, and high image quality of these machines are required. Further, due to the expansion of the user base, cost reduction and free maintenance of copying machines and printers are required, and as a result, it is also necessary to reduce the number of parts of the machine body and simplify the machine configuration.

As a result, the technical requirements for the consumer members such as toner and drums are increasing year by year.

As a developing method which achieves these requirements,
A contact developing method using a non-magnetic one-component developer (non-magnetic one-component contact developing method) is known.

In the non-magnetic one-component developer, the toner body is excellent in low-temperature fixability as compared with the magnetic toner. Further, since it does not contain an opaque magnetic material, it is also a preferable developer for obtaining a full-color or multi-color image. Furthermore, since the consumed developer and the developing device have a simple structure, it is easy to reduce the size of the machine and achieve free maintenance.

In the contact developing method, the toner layer carried on the surface of the toner carrying member is brought into contact with the surface of the electrostatic latent image carrying member to develop the electrostatic latent image to develop the toner image into the electrostatic latent image. This is a developing method in which it is formed on a carrier. Compared to the non-contact development method in which the toner layer carried on the surface of the toner carrier does not contact the surface of the electrostatic latent image carrier, fine line (or dot) reproducibility is excellent, and toner scattering is strong. There are merits.

On the other hand, styrene-acrylic resins, polyester resins, epoxy resins and the like are known as binder resins used for toners. Among them, the polyester resin is a binder resin because of its excellent charging characteristics and offset resistance, excellent image transparency when an overhead projector (OHP) film is used as a transfer material, and relatively low cost. Is preferably used as.

As described above, in order to achieve various requirements such as downsizing of machines, free maintenance, high definition of images, and full color, a method of combining a polyester toner with a non-magnetic one-component contact developing system. Is a very preferred development method.

However, as a result of various investigations by the present inventors using the above-mentioned image forming method, discontinuous fine streaks appear on a uniform halftone image in long-term use in a low humidity environment. , It became clear that the image quality was degraded.

FIG. 1 shows a schematic view of discontinuous minute stripes. FIG. 1 shows discontinuous continuous fine stripes appearing when a 15% density halftone image (size is A4) is printed.
It is a model enlarged view which emphasized the minute stripe part.

On a uniform halftone image, there are intermittently high density portions in the same direction as the rotation direction of the toner carrier. This portion is a discontinuous minute stripe which is a problem in the present invention. The length of the streak is about 0.5 to 2 cm,
Since it does not appear continuously and continuously in the image portion, it is distinguished from the so-called "image stripe". Further, the fine stripes had no pattern periodicity, and even when the fine stripes appeared, detailed observation of the surfaces of various members such as the photoconductor did not reveal any deposits corresponding to the fine stripe positions. From this, the minute stripes are also distinguished from "image stains" caused by the contamination of various members.

The appearance of the fine stripes is confirmed in a halftone image having a relatively light density. Immediately after the appearance of microscopic streaks, using a developing device in which microscopic streaks appeared, we printed all solid black, all solid white, and character images with a low printing rate, but no microscopic streaks could be confirmed in these images. .

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner capable of obtaining a high quality image without causing discontinuous fine stripes even when used for a long period of time.

Further, an object of the present invention is to provide an image forming method and a process cartridge in which discontinuous fine stripes do not occur even when used for a long period of time and a high quality image can be obtained.

[0015]

The present invention relates to a toner for forming an image by using a non-magnetic one-component developing system, wherein a toner regulating member is brought into contact with the surface of the toner carrying member. Toner layer forming step of controlling the upper toner layer; developing the electrostatic latent image by bringing the toner layer carried on the surface of the toner carrier into contact with the surface of the electrostatic latent image carrier to form a toner image. A developing step of forming on the electrostatic latent image carrier;
And the toner regulating member is 9.5 N / mm ² or more and 100 N / mm ² or more.
The toner has a universal hardness of less than mm ² , the toner contains at least a colorant and a binder resin, the toner has a number average particle diameter of 4 μm or more and less than 12 μm, and the toner particles have at least silica fine particles. In addition, the present invention relates to a toner characterized in that it has at least an inorganic fine powder A having a particle size larger than the primary particle size of the silica fine powder on the surface of the toner particles.

The present invention also relates to an image forming method using the toner described above and the toner layer regulating member described above, and to a process cartridge using these as constituent materials.

[0017]

DETAILED DESCRIPTION OF THE INVENTION As a result of intensive investigations by the present inventors, the universal hardness of a toner regulating member is defined, and the number average particle diameter of toner and the kind of external additive used are made suitable. Therefore, we found that discontinuous micro streaks were effectively suppressed under low humidity conditions.

The mechanism of the generation of discontinuous fine lines and the reason why the contents of the present invention are effective for the fine lines are not clear, but it is presumed to be as follows.

The inventors of the present invention first made detailed observations and examinations on the state of occurrence of discontinuous minute stripes and the state of the image forming apparatus when the minute stripes were generated. As a result, experimental results were obtained in which the appearance of discontinuous fine stripes was different when different toner layer regulating members were used. This experimental result suggests the relationship between the cause of the fine stripes and the toner layer regulating member.

The toner layer restriction member will be described with reference to FIG.

In FIG. 2, reference numeral 5 denotes a toner container containing a non-magnetic toner 4 as a one-component developer, and an electrostatic latent image bearing member is held in an opening extending in the longitudinal direction in the toner container 5. A developing roller 2 as a toner carrier, which is arranged to face the photosensitive drum 1 as a body, is rotatably arranged. Further, the developing roller 2 is horizontally installed so that the right half peripheral surface shown in the drawing projects into the toner container 5 at the opening of the toner container 5 and the left half peripheral surface is exposed to the outside of the toner container 5.

Regulation blade 3 as a toner regulation member
Is provided above the developing roller 2 by being supported by a pressing metal plate 6, and the vicinity of the free end side of the regulating blade 3 is in contact with the outer peripheral surface of the developing roller 2 in a surface contact state. Incidentally, the contact direction of the regulation blade 3 with the developing roller 2 is a so-called counter (reverse) direction in which the tip end side is located on the upstream side in the rotation direction of the developing roller 2 with respect to the contact portion.

The present inventors have made a more detailed observation of the state of the toner layer regulating member when the fine stripes are generated, especially the so-called nip surface where the toner layer regulating member and the toner carrier are in contact. It was As a result, for all the observed ones, free external additives (mainly silica) were added to the nip part.
Adhesion was observed. Most of the external additives are aggregated, and there are many agglomerates on the regulation member where a large number of fine lines are generated. There were few. Further, all the adhered substances were easily separated from the surface of the regulating member by applying a very small amount of force. Therefore, it was confirmed that a strong force such as a fusion phenomenon does not act between the deposit and the regulating member.

Based on the above experimental results, the present inventors have come to the idea that the mechanism of generation of discontinuous fine stripes is as follows.

That is, the aggregate of the free external additive stays and accumulates in the nip portion between the regulating member and the carrier (at this point, it does not affect the image characteristics), and when the aggregate exceeds a certain critical point. Peeling from the surface of the regulation member, peeling of the aggregate causes a temporary change in the charging ability of the regulation member in that portion, and a temporary change in the amount of toner on the peeling portion,
Just when printing a halftone image at that timing, discontinuous micro streaks occur.Since the charging ability of the portion where silica was staying immediately becomes the same charging performance as the periphery, it does not become a continuous streak. It is what

Based on the above idea, first, a policy was established that "the free external additive should not stay in the nip portion", and various studies were conducted. Specifically, studies were conducted such as 1) firmly fixing the external additive to the surface layer of the toner to eliminate the free external additive, and 2) changing the pressing pressure at the nip portion to prevent retention. . However, in 1), if the external addition is performed so strongly as to eliminate the free external additive, the developability is significantly impaired, and in 2), the free external additive stays in the nip portion at any pressing pressure. As a result of the experiment, favorable results were not obtained with this policy.

At this point, the present inventors have left the idea that "the free external additive is not retained in the nip portion" and "control the amount and the retention time of the free external additive in the nip portion".
It was decided to change to the way of thinking that, and based on this, a thorough study was conducted.

As a result, the present inventors set the universal hardness of the toner layer regulating member in a preferable range, set the average particle diameter of the toner in a preferable range, and added it to the toner particle surface layer. It has been found that the generation of discontinuous fine stripes can be suppressed by appropriately selecting the type of external additive.

That is, the essence of the present invention is to find out a technique for controlling the free external additive, which is always present in the nip portion, within a suitable range for a long period of time.

Here, the "universal hardness" in the present invention is measured according to the following measuring method.

(Universal hardness measuring method) The hardness was measured by using a hardness scale Fisher Scope H100 manufactured by Fisher, Germany. This device uses a diamond indenter whose shape is a quadrangular pyramid and the face-to-face angle is regulated to 136 °, and when a set load is gradually pushed into an object, the indentation search with the load applied. Is electrically detected and read. The hardness value H is displayed as a ratio of the test load divided by the surface area of the indentation generated by the test load. Further, the universal hardness value HU is represented by the hardness value at the set maximum indentation search.

In the present invention, the universal hardness value H
Setting when measuring U The maximum indentation depth was set to 15 μm and measurement was performed.

The reason why the universal hardness is an effective parameter in the present invention is presumed as follows.

The Fischer scope H100 is not a method in which an indenter is pushed into the surface of a test piece like the conventional microbiccus method and the residual dent after unloading is measured with a microscope to obtain hardness, and the indenter is continuously loaded. It is a measuring method in which the continuous hardness is obtained by directly reading the indentation depth under load. Therefore, it is possible to measure the hardness of the thin film elastic body, which has been difficult to measure conventionally.

Generally, as a method for measuring the hardness of the elastic body, it is a widely known method to use a Shore hardness tester or the like. However, the thickness of the test piece required in these measuring methods is several mm, which is thicker than the thickness of the toner layer regulating member actually used.

On the other hand, the universal hardness obtained by using the Fisher scope H100 can set the indentation depth in the unit of micron. The reason why the universal hardness is an effective parameter in the present invention is presumed to be that the surface hardness is measured in a state in which it is in conformity with the actual usage pattern.

In the present invention, the silica fine particles have the function of improving the fluidity of the toner particles and at the same time imparting a suitable charge to the toner particles, as in the prior art.

On the other hand, the inorganic fine powder A has a function of removing the silica agglomerates from the nip portion before the silica agglomerates are in a critical state. If the silica agglomerates are removed at this point, the deterioration of the charging ability of the blade is extremely small, and therefore no fine stripes are generated.

In the present invention, the inorganic fine powder A is
The silica fine powder has a shape in which particles larger than the primary particle diameter are aggregated. It is presumed that this shape effectively removes the silica aggregate accumulated in the vicinity of the nip portion.

Universal hardness of regulating member (N / m
m ² ) needs to be 9.5 or more and less than 100. If it is less than 9.5 (soft), not only the silica particles will accumulate, but also the differential body A will accumulate. As a result, the generation of fine streaks can be suitably suppressed immediately after the start of use of the apparatus, but with long-term use, fine streaks derived from the fine powder A will be generated. Therefore, rather, the fine streak level becomes worse than when fine powder A is not added,
Not preferable.

Universal hardness of 100 or more (hard)
Then, since the accumulation amount of silica particles is controlled by A, good results are obtained at first. However, since the surface layer of the regulating member is hard, A will be embedded in the surface of the toner particles with long-term use. Since the embedded A loses the silica control effect, the same state as when the actual A is not added occurs. As a result, the amount of silica cannot be controlled, and accumulation starts to occur, and fine streaks are generated, which rapidly deteriorates, which is not preferable.

Further, the toner used in the present invention is required to have a number average particle diameter of 4 μm or more and less than 12 μm. If the particle size is smaller than 4 μm, it becomes difficult to control the charging of each toner particle, and the halftone image used for confirming the generation of fine stripes becomes unpleasant and undesired. On the other hand, when the particle size exceeds 12 μm, the toner particles themselves stay in the nip, which causes fusion streaks, which is not preferable.

Incidentally, various proposals have been made in the past for a method of obtaining a preferable image by defining the state of the toner layer regulating member in the non-magnetic one-component developing device. For example, JP-A-11-149175 and JP-A-2
No. 001-147586. However,
These proposals have no description of discontinuous micro streaks, and it is unclear whether this problem can be solved only by using such a conventionally known technique. In fact, the present inventors tried to solve this problem by using these known techniques, but the effect was insufficient.

The differences between the prior art and the present invention will be described in more detail below.

In Japanese Unexamined Patent Publication No. 11-149175, a polyamide-containing elastomer having a Shore hardness of 25 degrees or more and 65 degrees or less is used for the surface layer of a regulating member to stabilize the formation of a thin toner layer on a toner carrier. A method for preventing fogging, streaks, and unevenness under high temperature and high humidity conditions has been proposed. However, the Shore hardness does not uniquely define the universal hardness. The universal hardness specified in the present invention is defined as the hardness at a minute portion and a minute displacement in a state in conformity with the actual usage pattern, and depends not only on the type of resin layer used but also on the thickness. The value changes.

The generation of discontinuous fine stripes can be suppressed only when the conditions of the toner layer regulating member, including the type of external additive used and the Shore hardness, are made appropriate. The present invention is distinguished in this respect from the prior art.

Further, in Japanese Unexamined Patent Publication No. 2001-147586, instead of a blade as a toner layer regulating member, a roller having a specified Asker C hardness is used, and foreign matter caught in a nip portion between the roller and the toner carrier is prevented from being transferred to the roller. It proposes a method of eliminating development unevenness on fine stripes by forcibly removing it by rotational movement.

This prior art is similar to the present invention in that the toner layer on the toner carrier is made preferable by controlling the foreign matter in the nip portion. However, what the prior art intends to remove as foreign matter is dust such as paper scraps, and a developer lump formed by a deteriorated developer, and is not a free external additive which is a control target of the present invention. The free external additive in the nip portion is preferably controlled for the first time by a combination with the toner layer regulating member selected according to its type and universal hardness, so that it can be controlled even by using the prior art. The idea is clearly denied.

Other constituent elements for further enhancing the operation and effect of the present invention will be described below in order.

The binder resin used in the toner of the present invention is
It preferably contains a crosslinked polyester. When the toner particles in the contact development system contain the crosslinked polyester, fine streaks do not occur even when the toner particles are used for a longer period of time. Although the detailed reason for this is not clear, it is considered that the effect of preventing the external additive from being embedded appears due to the elasticity of the crosslinked polyester.

In the toner of the present invention, the number of particles having a particle size of 0.6 to 2.0 μm measured by a flow type particle image measuring device is 50.0% or more and less than 70.0% by number of the whole particles. preferable. The content of less than 2.0 μm substantially represents the particle size and the addition amount of the inorganic fine powder A.

When the amount of particles having a particle size of 0.6 to 2.0 μm is less than 50.0% by number of all particles, the working effect of the fine powder A cannot be maintained favorably for a long period of time. Also, 7
If it exceeds 0.0% by number, the fine powder A is significantly embedded in the surface layer of the toner particles during long-term use, the charging characteristics of the toner are changed, and the image quality is affected.

Further, in the present invention, the silica fine powder is contained in the toner particles in an amount of 0.01% by mass or more and less than 2.0% by mass, and the inorganic fine powder A is 0.0 in the toner particles.
It is more preferable that the content is 1% by mass or more and less than 2.0% by mass. With the above addition amount, it becomes easy to set the number% of particles of less than 2.0 μm in a preferable range, and in addition, image characteristics other than minute stripes such as image density stability are good for a long time. Will be things.

In the present invention, an elastic layer containing a nitrogen-containing compound is preferably provided on the surface layer of the toner layer regulating member. When the surface layer material is a nitrogen-containing compound, the time during which the silica particles stay in the nip portion can be shortened. Although the detailed reason for this is unknown, it seems that there is some correlation with the charging characteristics when the silica particles and the resin rub against each other.

Specific examples of the nitrogen-containing compound include polyurethane, polyamide elastomer, and various nylons. Among them, the polyamide elastomer is excellent in moldability and charging characteristics and can be suitably used.

In the present invention, the inorganic fine powder A preferably has a particle size larger than the primary particle size of the silica fine powder. In a more preferable form, the inorganic fine powder A is
The silica fine powder is present as an aggregate of particles larger than the primary particle size, and is preferably a fine powder selected from the following compound group B. Compound group B: calcium titanate, strontium titanate, barium titanate

When these particles are used, the particle size distribution of the toner, which is the preferred form of the present invention, can be easily achieved, and the generation of discontinuous fine stripes can be suppressed for a long period of time. become. Although the detailed reason for this is unknown, it is considered that the hardness of the fine particles, the order of charging with various materials, and the like have an influence.

The shapes and particle sizes of various external additives were determined by using a scanning electron microscope (SEM). Specifically, Hitachi's FE-SEM is used to randomly sample fine particles on the toner that have been magnified 50,000 times, and the arithmetic mean value of the major axis diameter and the minor axis diameter of the fine particles is calculated. The average particle size was used. The same operation was performed over 100 fine particles, and the arithmetic average was used to obtain the number average particle diameter of the fine particles.

Regarding the measurement of the number average particle diameter of the toner in the present invention and the number% of the particles having a particle diameter of 0.6 to 2.0 μm, the flow type particle image measuring apparatus “FPIA-” is used.
1000 "(manufactured by Toa Medical Electronics Co., Ltd.).

For the measurement, fine dust was removed through a filter, and as a result, the measurement range (for example, circle equivalent diameter of 0.60 μm or more and 159.21 μm) was measured in 10 ⁻³ cm ³ of water.
The surface-active agent (preferably Contaminone manufactured by Wako Pure Chemical Industries, Ltd.) is added to ion-exchanged water having a particle number of less than 20 (m.
About 10 ml of solution prepared by adding 0.5% by mass (20 ° C)
Then, about 0.02 g of the measurement sample is added and uniformly dispersed to prepare a sample dispersion liquid. As a means for dispersing, an ultrasonic disperser “UH-50” manufactured by SMT Co., Ltd.
mm titanium alloy chip) is used. The dispersion time is 5 minutes or more, and at this time, the dispersion medium is appropriately cooled so that the temperature of the dispersion medium does not exceed 40 ° C. The particle size of particles having a circle equivalent diameter of 0.60 μm or more and less than 159.21 μm is measured using the above-mentioned flow type particle image analyzer.

The outline of the measurement is “F” issued by Toa Medical Electronics Co., Ltd.
PIA-1000 ”catalog (June 1995 version),
Operation manual for measuring device and JP-A-8-136439
Although it is described in Japanese Patent Publication No. JP-A-2003-242, it is as follows.

The sample dispersion is passed through a flat and flat transparent flow cell (thickness of about 200 μm) (spreading along the flow direction). A strobe and a CCD camera are mounted on opposite sides of the flow cell so as to form an optical path that intersects and passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is illuminated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Two
It is taken as a three-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.

As shown in Table 1, the results (frequency% and cumulative%) can be obtained by dividing the range of 0.06 to 400 μm into 226 channels (divided into 30 channels for one octave). In the actual measurement, the equivalent circle diameter is 0.
Particles are measured in the range of 60 μm or more and less than 159.21 μm.

[0064]

[Table 1]

In the toner used in the present invention, various resins can be used as the binder resin in addition to the crosslinked polyester. In the present invention, the affinity for the crosslinked polyester and the charge when the toner is used are obtained. From the viewpoint of stability, etc.
It is preferable to use a crosslinked polyester and a non-crosslinked polyester together. As the polyester used, it is preferable to use a polyester resin obtained by polycondensing a polyhydric alcohol component and a polyvalent carboxylic acid component, and a polyester resin obtained by polycondensing a divalent alcohol component and a divalent carboxylic acid component is preferably used. The crosslinked polyester can be obtained by using a trivalent or higher valent alcohol component and / or a trivalent or higher valent carboxylic acid component in combination therewith.

Among the polyhydric alcohol components, examples of the dihydric alcohol component include polyoxypropylene (2,
2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2
Bisphenol A alkylene oxide adduct such as bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl Glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A Etc.

Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,
2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3.
5-trihydroxymethylbenzene etc. are mentioned.

Examples of the divalent carboxylic acid component among the polyvalent carboxylic acid components include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid. , Succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, isooctenylsuccinic acid, n- Examples thereof include octyl succinic acid, isooctyl succinic acid, and anhydrides or lower alkyl esters of these acids.

Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,
5,7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 1,3-
Dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,
7,8-octanetetracarboxylic acid, pyromellitic acid,
Examples thereof include empol trimer acids, anhydrides of these acids, and lower alkyl esters.

The toner of the present invention contains a colorant for imparting coloring power. The organic pigments or dyes preferably used in the present invention include the following.

As the organic pigment or organic dye as the cyan colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I. Pigment Blue 1, C.I. I. Pigment Blue 7, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 1, C.I.
I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4
C. I. Pigment Blue 60, C.I. I. Pigment Blue 62, C.I. I. Pigment Blue 66 and the like.

Examples of organic pigments or organic dyes as magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds. Is used. Specifically, C.I. I. Pigment Red 2,
C. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Violet 19,
C. I. Pigment Red 23, C.I. I. Pigment Red 48: 2, C.I. I. Pigment Red 48: 3
C. I. Pigment Red 48: 4, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 81:
1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 144, C.I. I. Pigment Red 146,
C. I. Pigment Red 166, C.I. I. Pigment Red 169, C.I. I. Pigment Red 177, C.I.
I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 202, C.I. I.
Pigment Red 206, C.I. I. Pigment Red 2
20, C.I. I. Pigment Red 221, C.I. I. Pigment Red 254 and the like.

As the organic pigment or organic dye as the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I.
I. Pigment Yellow 17, C.I. I. Pigment Yellow 62, C.I. I. Pigment Yellow 74, C.I. I.
Pigment Yellow 83, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 9
7, C.I. I. Pigment Yellow 109, C.I. I. Pigment Yellow 110, C.I. I. Pigment Yellow 1
11, C.I. I. Pigment Yellow 120, C.I. I. Pigment Yellow 127, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 129, C.I. I.
Pigment Yellow 147, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 154, C.I.
I. Pigment Yellow 168, C.I. I. Pigment Yellow 174, C.I. I. Pigment Yellow 175,
C. I. Pigment Yellow 176, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 18
1, C.I. I. Pigment Yellow 191, C.I. I. Pigment Yellow 194 and the like.

As the black colorant, carbon black,
A color tone adjusted to black using the yellow / magenta / cyan colorant is used.

These colorants can be used alone or in combination, and can be used in the form of solid solution. The colorant used in the toner of the present invention includes hue angle, saturation, lightness, light resistance,
It is selected from the viewpoints of OHP transparency and dispersibility in toner.

The colorant is added in an amount of 1 to 20 parts by mass based on 100 parts by mass of the binder resin. A low melting point compound, so-called wax, can be added to the toner in the present invention, if necessary.

Examples of waxes usable in the toner according to the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, petroleum lactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax by the Fischer-Tropsch method and the wax thereof. Derivatives, polyolefin waxes represented by polyethylene and polypropylene and their derivatives, natural waxes such as carnauba wax and candelilla wax and their derivatives, which are oxides, block copolymers with vinyl monomers, and graft modified products. including. Moreover,
Higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide wax, ester wax, ketone, hydrogenated castor oil and its derivatives, plant wax, animal wax and the like can also be used.

In the toner relating to the image forming method of the present invention, the content of these wax components is preferably less than 20% by mass, more preferably less than 10% by mass with respect to the toner. That is. If the wax component content exceeds 20% by mass, the long-term storage stability and durability will be slightly inferior. Further, when toner particles are obtained by a pulverization method, if an excessive amount of wax is contained, the pulverizability becomes poor, and it becomes difficult to manufacture the toner.

The toner relating to the image forming method of the present invention may be blended with a charge control agent in order to stabilize the charging characteristics. Known charge control agents can be used,
In particular, a charge control agent having a high charging speed and capable of stably maintaining a constant charge amount is preferable.

Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid and dicarboxylic acids, metal salts or metals of azo dyes or azo pigments. Examples thereof include a complex, a polymer type compound having a sulfonic acid or carboxylic acid group as a side chain, a boron compound, a urea compound, a silicon compound, and calixarene. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer type compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, an imidazole compound, and the like. The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin. However, in the toner relating to the image forming method of the present invention, it is not essential to add the charge control agent, and it is not always necessary to positively utilize the triboelectric charge between the toner layer thickness regulating member and the developer carrying member. It is not necessary to include a charge control agent.

In the present invention, it is possible to add a small amount of resin other than polyester resin. For example, epoxy resin, styrene resin, acrylic resin, olefin resin, diene resin, polyamide resin, silicone resin, phenol resin, petroleum resin, urethane resin, etc. may be mentioned.

When using these resins, it is necessary to pay attention to the compatibility with the polyester resin. In order to improve the compatibility, those having various functional groups introduced at the polymer terminals can be preferably used.

The addition amount of these resins is preferably less than 15% by mass with respect to the mass of the toner.

In the present invention, the glass transition temperature (Tg) of the toner particles is preferably 50 to 65 ° C. If the Tg is less than 50 ° C, problems tend to occur from the viewpoint of storage stability and durability stability of the toner, and if it exceeds 65 ° C, the fixing point of the toner increases. Particularly, in the case of a color toner for forming a full-color image, the color mixing property of each color toner at the time of fixing is deteriorated, the color reproducibility is poor, and the transparency of the OHP image is deteriorated, which is not preferable.

In the present invention, for the measurement of Tg, for example, "DSC-7" manufactured by Perkin Elmer Co. is used. The melting point of indium and zinc is used to correct the temperature of the device detection unit, and the heat of fusion of indium is used to correct the amount of heat. An aluminum pan was used as a sample and an empty pan was set as a control, and the temperature rising rate was 10 ° C./min. Measure with.

In the toner of the present invention, in addition to silica and the inorganic fine powder A, it is possible to add organic or inorganic fine particles generally widely known as an external additive. Specific examples of the inorganic fine particles include metal oxides (aluminum oxide, titanium oxide, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.), nitrides (silicon nitride, etc.), metal salts (calcium sulfate, Barium sulfate, calcium carbonate, etc., fatty acid metal salts (zinc stearate, calcium stearate, etc.), carbon black, etc. can be used. Examples of the organic fine particles include homopolymers or copolymers of monomer components used in the binder resin for toner, such as styrene, acrylic acid, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, which are obtained by emulsion polymerization or spray drying. Polymers can be used. Moreover, it is also possible to use a plurality of types of these fine particles in combination, if necessary.

These fine particles are contained in the toner in an amount of 0.1 to 0.1
With the addition amount of 3.0% by mass, it can be used without hindering various effects described in the present invention.

The method for producing the toner according to the present invention is not particularly limited, and the toner constituent materials such as the colorant and the charge control agent are uniformly mixed with the binder, melt-kneaded, and the resulting kneaded product is cooled and then jet-milled. A so-called pulverization method in which a fluidity modifier and the like are externally added can be used. In addition, when a compound such as a metal complex that causes crosslinking during kneading is added at the same time when the resin is melt-kneaded, a crosslinked polyester can be produced during toner production.

As another method of the toner manufacturing method, a colorant, a charge control agent and the like are mixed and dispersed in a solution consisting of a solvent and a binder, and then the solution is introduced into a water system to be suspended or roughly emulsified.
It is possible to use a toner forming method by a wet process such as classification drying. In the present invention, particularly when the polyester resin contains an ionic group, the polyester resin exhibits water dispersibility (self-emulsifying property).
In this case, it is possible to exemplify a method in which a polyester resin is emulsified and dispersed in an aqueous system, and the polyester resin fine particles contained in the obtained dispersion are slowly aggregated to grow the coalescence into a size suitable for the toner to obtain the toner.

The polyester resin is dissolved in a water-soluble solvent such as ketones, alcohols, tetrahydrofuran, cellosolves, dioxane and the like, and then water is added and the solvent is removed by azeotropic distillation to give an aqueous dispersion of the polyester resin. Obtainable. Slow coagulation can be achieved by adding an appropriate amount of electrolyte into the water dispersion system and controlling the temperature. In particular, a method of adding an amino group-containing ester consisting of amino alcohols and carboxylic acids, and hydrolyzing the ester in the system by raising the temperature, adjusting the pH, or the like to produce an amine salt of a carboxylic acid leads to a slow aggregation region. Preferred as a method. Particles containing a pigment (carbon black) can be produced if water-dispersed fine particles such as a pigment and carbon black coexist in the slow aggregation region. Further, it is possible to obtain toner particles colored with a dye by allowing a dye to coexist at the time of emulsification, and it is also possible to post-color the colorless particles obtained by a high temperature dispersion dyeing method.

As the toner particles according to the present invention, surface-modified particles can be used. Particularly, when the toner particles are obtained by a pulverization method, the surface modification effect is suitably exhibited, which is preferable.

As a device for surface modification treatment, a high-speed air impact method such as a hybridization system (manufactured by Nara Machinery Co., Ltd.), a klyptron system (manufactured by Kawasaki Heavy Industries, Ltd.), an inomizer system (manufactured by Hosokawa Micron Co., Ltd.), etc. Surface reformer applying MechanoFusion Systel (manufactured by Hosokawa Micron), MechanoMill (manufactured by Okada Seiko Co., Ltd.), etc., surface modifier applied by dry mechanochemical method, Tispercoat (manufactured by Nisshin Engineering Co., Ltd.), Momentary heat treatment for instantaneous heat treatment of toner particles such as surface reforming equipment applying wet coating method such as Coatmizer (made by Freund Industrial Co., Ltd.) and surffusion system (made by Nippon Pneumatic Mfg. Co., Ltd.) The devices can be appropriately used alone or in combination.

Next, the image forming method of the present invention and the image forming apparatus for carrying out the method will be described.

An elastic roller is used as the toner carrier,
A method may be used in which the surface of the elastic roller or the like is coated with toner and the surface of the photosensitive member is brought into contact with the toner. In this case, development is performed by an electric field acting between the photoconductor and the elastic roller facing the photoconductor surface via the toner. Therefore, it is necessary that the surface of the elastic roller or the vicinity of the surface has an electric potential, and the electric field is present in a narrow gap between the surface of the photoconductor and the surface of the toner carrier. Therefore, it is possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in a medium resistance region to prevent electric conduction with the surface of the photoconductor and maintain an electric field, or a thin insulating layer is provided on the surface layer of the conductive roller. . Further, it is possible to adopt a configuration in which a conductive resin sleeve in which the side facing the surface of the photoconductor is coated with an insulating material is provided on the conductive roller, or a conductive layer is provided on the side not facing the photoconductor with the insulating sleeve. . Also,
It is also possible to use a rigid roller as the toner carrier and make the photoconductor flexible such as a belt. The roller as a toner carrier has a resistance value of 10 ² to 10 ⁹
The range of Ω · cm is preferable.

If the surface roughness Ra (μm) of the toner carrier is set to 0.2 to 3.0, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability.
When the surface roughness Ra of the toner carrier exceeds 3.0, not only is it difficult to thin the toner layer on the toner carrier, but also the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. . When it is 3.0 or less, the toner carrying ability on the surface of the toner carrier is suppressed, the toner layer on the toner carrier is thinned, and the number of times of contact between the toner carrier and the toner increases, Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, the surface roughness Ra is 0.2
If it is smaller than this, it becomes difficult to control the toner coat amount.

In the present invention, the surface roughness Ra of the toner carrier is based on JIS surface roughness "JISB 0601", and a surface roughness measuring device ("Surfcoder S" manufactured by Kosaka Laboratory Ltd.) is used.
E-30H "). Specifically, a 2.5 mm portion having a measurement length a in the direction of the center line is extracted from the roughness curve, the center line of this extracted portion is the X axis, the direction of longitudinal magnification is the Y axis, and the roughness curve is When represented by y = f (x), the value obtained by the following equation is expressed in micrometers (μm).

[0097]

[Equation 1]

In the image forming method of the present invention, the toner carrier may rotate in the same direction as the peripheral speed of the photoconductor,
It may rotate in the opposite direction. When the rotation is in the same direction, the peripheral speed of the toner carrier is 1.0 with respect to the peripheral speed of the photoconductor.
It is preferable to set it to be 5 to 3.0 times.

When the peripheral speed of the toner carrying member is less than 1.05 times the peripheral speed of the photosensitive member, the stirring effect of the toner on the photosensitive member is insufficient, and good image quality cannot be expected.
If the peripheral speed ratio exceeds 3.0, deterioration of the toner due to mechanical stress and toner sticking to the toner carrier occur and are promoted, which is not preferable.

Examples of the photoconductor include a-Se, CdS,
A photosensitive drum or photosensitive belt having a photoconductive insulating material layer such as ZnO ₂ , OPC, or a-Si is preferably used. Further, the binder resin of the organic photosensitive layer in the OPC photosensitive member is not particularly limited. Of these, polycarbonate resins, polyester resins, and acrylic resins are particularly preferable because they are excellent in transferability and are less likely to cause fusion of the toner to the photosensitive member and filming of the external additive.

Next, the image forming method of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 is a schematic configuration diagram of an example of an apparatus for carrying out the image forming method of the present invention. In FIG. 3, reference numeral 10 is a primary charging member that is in direct contact with the photosensitive drum 1 to perform direct charging. Rollers 11 to 13 are bias power sources, 15 is a transfer material such as paper, 16 is a transfer member, 17 is a fixing pressure roller, 18 is a fixing heating roller, and 19 is a cleaner. The same reference numerals are attached.

A bias power source 11 is connected to the charging roller 10 so as to uniformly charge the surface of the photosensitive drum 1. The developing device 7 accommodates the toner 4 in a toner container 5 and includes a developing roller 2 that is a toner carrier that rotates in the arrow direction. Further, a regulating blade 3 and a toner 4, which are toner regulating members for regulating toner and imparting electric charge, are attached to the developing roller 2 and rotated in an arrow direction in order to impart electric charge to the toner by friction with the developing roller 2. A coating roller 9 is also provided. A developing bias power source 13 is connected to the developing roller 2. A bias power source (not shown) is also connected to the coating roller 9, and a voltage is applied to the negative side of the developing bias when the negative charging toner is used, and to the positive side of the developing bias when the positive charging toner is used. Is set.

A transfer bias power source 12 having a polarity opposite to that of the photosensitive drum 1 is connected to the transfer member 16.

As the developing roller 2 which is a toner carrier, a so-called elastic roller having an elastic layer on its surface is preferably used. The hardness of the material of the elastic layer used for the elastic roller is preferably 30 to 60 degrees (asker-C / load 1 kg).

The toner coating amount is controlled by the regulating blade 3, which is in contact with the developing roller 2 via the toner layer. Regulation blade 3 at this time
The contact pressure between the developing roller 2 and the developing roller 2 is preferably 0.05 N / cm or more and 0.5 N / cm or less as a linear pressure in the generatrix direction of the developing roller 2.

The linear pressure is a load applied per length of the blade 3. For example, a load of 1.2 N is applied to the blade 3 having a contact length of 1 m to bring it into contact with the developing roller 2. In that case, the linear pressure is 1.2 N / m. 0.
If it is less than 05 N / cm, uniform triboelectric charging becomes difficult in addition to the control of the toner coat amount, which causes deterioration of fog. On the other hand, if it is higher than 0.5 N / cm, the toner particles are excessively loaded, and the deformation of the particles and the fusion of the toner to the regulation blade 3 or the developing roller 2 are likely to occur, which is not preferable.

The free end portion of the regulating blade 3 may have any shape, for example, other than a linear cross section,
An L-shaped one bent near the tip, a bulged part near the tip in a spherical shape, or the like is preferably used.

As the toner regulating member, it is preferable to use a metal elastic body such as stainless steel, steel or phosphor bronze as a base material, and to which a resin is adhered or coated on a portion corresponding to a sleeve contact portion.

Furthermore, by applying a DC electric field and / or an AC electric field to the toner regulating member, the uniform thin layer coating property and the uniform charging property are further improved due to the loosening effect on the toner, and a sufficient image density is obtained. Can be achieved and good quality images can be obtained.

In FIG. 3, the photosensitive drum 1 rotating in the direction of the arrow is uniformly charged by the primary charging member. In the present example, the primary charging member is a charging roller 10 having a central core metal 10b and a conductive elastic layer 10a forming the outer periphery thereof as a basic configuration. The charging roller 10 is brought into contact with one surface of the photosensitive drum 1, which is an electrostatic latent image carrier, with a suppression force, and is driven to rotate as the photosensitive drum 1 rotates.

A preferable process condition when the charging roller 10 is used is that the contact pressure of the roller is 0.05 to 5 N /
The applied voltage may be a DC voltage or a DC voltage superimposed with an AC voltage, and is not particularly limited. However, when a DC voltage superimposed with an AC voltage is used, the AC voltage is 0.5. ~ 5dVpp, AC frequency = 5
0 Hz to 5 kHz, DC voltage = ± 0.2 to ± 1.5 kV
Therefore, when a DC voltage is used, the DC voltage = ± 0.2
Is ± 5 kV. In the present invention, the applied voltage of only the DC voltage is preferably used.

As charging means other than the charging roller 10,
There are a method using a charging blade and a method using a conductive brush. These contact charging means have an effect that a high voltage becomes unnecessary and ozone generation is reduced as compared with non-contact corona charging. As a material of the charging roller and the charging blade as the contact charging means, conductive rubber is preferable, and a releasing film may be provided on the surface thereof.
As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride)
Are applicable.

After the electrostatic latent image carrier charging step, an electrostatic latent image corresponding to an information signal is formed on the photosensitive drum 1 by, for example, exposure 14 from a light emitting element, and the developing roller 2
The toner develops the electrostatic latent image into a visible image at a position where the electrostatic latent image comes into contact with. Further, in the image forming method of the present invention, particularly by combining with a developing system in which a digital latent image is formed on the photosensitive drum 1, it is possible to faithfully develop a dot latent image without disturbing the latent image. Becomes The visible image is transferred to the transfer material 15 by the transfer member 16 and passes between the heating roller 18 and the pressure roller 17 to be fixed to obtain a permanent image. The heating / pressurizing fixing means is basically a heating roller 18 having a built-in heating element such as a halogen heater and an elastic pressing roller 17 pressed against the heating roller 18 as a basic structure. In addition, a method of heating and fixing with a heater through a film is also used.

On the other hand, the untransferred toner remaining on the photosensitive drum 1 without being transferred is collected by the cleaner 19 having a cleaning blade which is in contact with the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned. It

FIG. 4 is a schematic block diagram of an example of an image forming apparatus for collectively transferring multiple toner images onto a recording material by using an intermediate transfer member in the image forming method of the present invention.

In FIG. 4, 7a to 7d are developing devices for respective colors of black, yellow, magenta, and cyan, 21 is a light source device, 22 is a laser beam, 23 is a fixing device, 24 is a developing unit, and 25 is an intermediate transfer. An intermediate transfer drum, which is a body, 25a is a conductive support, 25b is an elastic layer,
Reference numeral 26 is a bias power source, 27 is a transfer material tray, and 28 is a secondary transfer device. The same members as those in FIGS. 2 and 3 are denoted by the same reference numerals.

The surface of the photosensitive drum 1 serving as the electrostatic latent image carrier is brought into contact with the surface of the photosensitive drum 1 while rotating the rotatable charging roller 10 as a charging member to which a charging bias voltage is applied to rotate the surface of the photosensitive drum 1. A first electrostatic latent image is formed on the photoconductor drum 1 by the laser light 22 emitted from the light source device 21 as the exposure means, which is uniformly primary charged.
The formed first electrostatic latent image is developed with the black toner in the black developing device 7a as the first developing device provided in the rotatable developing unit 24 to form a black toner image. The black toner image formed on the photoconductor drum 1 is electrostatically primarily transferred onto the intermediate transfer drum 25 by the action of the transfer bias voltage applied to the conductive support 25 a of the intermediate transfer drum 25.
Next, in the same manner as described above, a second electrostatic latent image is formed on the surface of the photosensitive drum 1, the developing unit 24 is rotated, and the second electrostatic latent image is formed.
Of the yellow developing device 7b as a developing device for developing the yellow toner image to form a yellow toner image, and the black toner image is primarily transferred to the intermediate transfer drum 25.
The yellow toner image is electrostatically primary-transferred thereon. Similarly, the developing unit 24 is rotated to generate the third electrostatic latent image and the fourth electrostatic latent image, and the magenta toner in the magenta developing device 7c as the third developing device and the fourth developing device are used as the fourth developing device. The cyan toner in the cyan developing device 7d performs sequential development and primary transfer, and the toner images of the respective colors are primarily transferred onto the intermediate transfer drum 25. Intermediate transfer drum 2
The multiple toner image primarily transferred onto the transfer material 5 is electrostatically and collectively transferred onto the transfer material 15 by the operation of the transfer bias voltage from the secondary transfer device 28 located on the opposite side through the transfer material 15. Next is transcribed. The multiple toner image secondarily transferred onto the transfer material 15 is heat-fixed on the transfer material 15 by a fixing device 23 having a heating roller 17 and a pressure roller 18. The transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer is collected by the cleaner 19 having a cleaning blade that contacts the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

The primary transfer from the photosensitive drum 1 to the intermediate transfer drum 25 is performed by the intermediate transfer drum 2 as a primary transfer device.
A transfer current is obtained by applying a bias from the bias power supply 26 to the conductive support 25a of No. 5 to transfer the toner image.

The intermediate transfer drum 25 comprises a rigid conductive support 25a and an elastic layer 25b covering the surface. As the conductive support 25a, a metal or alloy such as aluminum, iron, copper and stainless, and a conductive resin in which carbon or metal particles are dispersed can be used, and the shape thereof is cylindrical or cylindrical. Examples thereof include those having a shaft penetrating through the center and those having reinforcement inside the cylinder.

The elastic layer 25b is not particularly limited, but styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-
Propylene copolymer, nitrile butadiene rubber (NB
R), chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber, norbornene rubber, and other elastomer rubbers are preferably used. A resin such as a polyolefin resin, a silicone resin, a fluorine resin, a polycarbonate, or a copolymer or mixture thereof may be used.

Further, on the surface of the elastic layer 25b, a surface layer in which lubricant powder having high lubricity and water repellency is dispersed in an arbitrary binder may be provided.

The lubricant is not particularly limited, but various fluororubbers, fluoroelastomers, graphite or fluorocarbons having fluorine bonded to graphite and polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene. Copolymer (ETFE)
And fluorine compounds such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), silicone-based particles such as silicone resin particles, silicone rubber and silicone elastomer, polyethylene (P
E), polypropylene (PP), polystyrene (P
S), acrylic resin, polyamide resin, phenol resin, epoxy resin and the like are preferably used.

A conductive agent may be added to the binder of the surface layer in order to control the resistance. Examples of the conductive agent include various conductive inorganic particles and carbon black, ionic conductive agents, conductive resins and conductive particle dispersed resins.

The multiple toner image on the intermediate transfer drum 25 is
Secondary transfer is collectively secondary-transferred onto the transfer material 15 by the secondary transfer device 28. As the transfer device 28, a non-contact electrostatic transfer means using a corona charger or a contact electrostatic transfer means using a transfer roller and a transfer belt is used. It can be used.

The fixing device 23 is replaced with a heat roller fixing device having a heating roller 18 and a pressure roller 17, and the film in contact with the toner image on the transfer material 15 is heated, thereby the toner image on the transfer material 15 is heated. And transfer material 15
It is also possible to use a film heat fixing device that heat-fixes the multiple toner images.

Instead of the intermediate transfer drum 25 as an intermediate transfer member used in the image forming apparatus shown in FIG. 4, it is also possible to use an intermediate transfer belt to collectively transfer multiple toner particles onto a recording material. A schematic configuration diagram of an apparatus using the intermediate transfer belt is shown in FIG.

In FIG. 5, 30 is an intermediate transfer belt, and 3 is
1, 1 is a roller for passing the intermediate transfer belt 30, 32 is a primary transfer roller, 33a is a secondary transfer counter roller, 33b is a secondary transfer roller, 34 to 36 are bias power sources, 39 is a cleaning charging member, and FIG. The same members as those in FIG. 4 are designated by the same reference numerals.

In the structure of FIG. 5, the toner image formed and carried on the photosensitive drum 1 passes from the primary transfer roller 32 to the intermediate transfer belt while passing through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 30. By the electric field formed by the primary transfer bias applied to 30, the primary transfer is sequentially performed on the outer peripheral surface of the intermediate transfer belt 30.

The primary transfer bias for sequentially superposing and transferring the toner images of the first to fourth colors from the photoconductor drum 1 to the intermediate transfer belt 30 has a polarity opposite to that of the toner and is applied from the bias power source 34.

In the primary transfer process of the toner images of the first to fourth colors from the photosensitive drum 1 to the intermediate transfer belt 30,
Secondary transfer roller 33b and cleaning charging member 39
Can be separated from the intermediate transfer belt 30.

Reference numeral 33b denotes a secondary transfer roller, which corresponds to the secondary transfer counter roller 33a and is supported in parallel to the lower surface portion of the intermediate transfer belt 30 so as to be separated therefrom.

The transfer of the composite color toner image transferred on the intermediate transfer belt 30 to the transfer material 15 is performed by the secondary transfer roller 33b contacting the intermediate transfer belt 30 and the intermediate transfer belt 30 and the secondary transfer. The transfer material 15 is fed to the contact nip with the roller 33b at a predetermined timing, and the secondary transfer bias is applied from the bias power source 36 to the secondary transfer roller 33.
applied to b. By this secondary transfer bias, the composite color toner image is secondarily transferred from the intermediate transfer belt 30 to the transfer material 15.

After the image transfer onto the transfer material 15, the cleaning charging member 39 is brought into contact with the intermediate transfer belt 30, and a bias having a polarity opposite to that of the photosensitive drum 1 is applied from the bias power source 35 to transfer the image. Toner remaining on the intermediate transfer belt 30 without being transferred to the material 15 (transfer residual toner) is charged with an electric charge having a polarity opposite to that of the photosensitive drum 1. Next, the transfer residual toner is transferred to the photosensitive drum 1 in the nip portion with the photosensitive drum 1 and in the vicinity thereof, whereby the intermediate transfer belt 30 is cleaned.

The intermediate transfer belt 30 comprises a belt-shaped base layer and a surface treatment layer provided on the base layer. The surface treatment layer may be composed of a plurality of layers.

For the base layer and the surface treatment layer, rubber, elastomer or resin can be used. For example, as rubber and elastomer, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, acrylonitrile butadiene rubber, Urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluororubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber and thermoplastic elastomer (for example, polystyrene type, polyolefin type,
One kind or two or more kinds selected from the group consisting of polyvinyl chloride type, polyurethane type, polyamide type, polyester type, fluororesin type and the like) can be used. However, the material is not limited to the above materials. Also,
As the resin, a resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate can be used. You may use the copolymer or mixture of these resins.

As the base layer, the above-mentioned rubber, elastomer,
The resin can be used in the form of a film. Also,
A woven fabric-shaped, non-woven fabric-shaped, thread-shaped, or film-shaped core body layer may be coated with, dipped, or sprayed with the above-mentioned rubber, elastomer, or resin.

The material constituting the core layer is, for example, cotton, silk,
Natural fibers such as hemp and wool; regenerated fibers such as chitin fibers, alginic acid fibers and regenerated cellulose fibers; semi-synthetic fibers such as acetate fibers; polyester fibers, nylon fibers, acrylic fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers Synthetic fibers such as polyvinylidene chloride fiber, polyurethane fiber, polyalkylparaoxybenzoate fiber, polyacetal fiber, aramid fiber, polyfluoroethylene fiber and phenol fiber;
One or more selected from the group consisting of inorganic fibers such as carbon fibers, glass fibers and boron fibers; metal fibers such as iron fibers and copper fibers can be used. Of course, the material is not limited to the above.

Further, a conductive agent may be added to the base layer and the surface treatment layer in order to adjust the low resistance value of the intermediate transfer belt 30. Although the conductive agent is not particularly limited, for example, carbon, metal powders such as aluminum and nickel, metal oxides such as titanium oxide, and quaternary ammonium salt-containing polymethylmethacrylate, polyvinylaniline, polyvinylpyrrole, One or more selected from the group consisting of conductive polymer compounds such as polydiacetylene, polyethyleneimine, boron-containing polymer compounds and polypyrrole can be used. However, the conductive agent is not limited to the above.

Further, a lubricant may be added if necessary in order to improve the slipperiness of the surface of the intermediate transfer belt 30 and improve the transferability. The lubricant is not particularly limited, but various fluororubbers, fluoroelastomers, graphite and fluorocarbons obtained by binding fluorine to graphite, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVD).
F), ethylene-tetrafluoroethylene copolymer (E
Fluorine compounds such as TFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), silicone compounds such as silicone resin, silicone rubber and silicone elastomer, polyethylene (P
E), polypropylene (PP), polystyrene (P
S), acrylic resin, polyamide resin, phenol resin, epoxy resin and the like are preferably used.

Next, a schematic configuration diagram of an apparatus in which toner images of respective colors are respectively formed in a plurality of image forming sections and which are successively superposed and transferred onto the same transfer material will be described with reference to FIG.

In FIG. 6, 1a to 1d are photosensitive drums, 19a to 19d are cleaners, 41a to 41d are image forming portions, 42a to 42d are latent image forming means, and 43a to 4d.
3d is a transfer discharge part, 44a to 44d are primary charging parts, 4
Reference numeral 5 is a static eliminator, 46 is a conveyor belt, 7a to 7d are developing devices, 48 is an adsorption charger, 49a to 49d are separate static eliminators and discharge parts, and 50 is a discharge port. Numbers are attached.

In the structure of FIG. 6, first to fourth image forming portions 41a to 41d are arranged in parallel, and each image forming portion is a photosensitive drum 1a to 1a which is a dedicated electrostatic latent image carrier.
It has d. The photosensitive drums 1a to 1d are provided with latent image forming means 42a to 42d and developing devices 7a to 7 on the outer peripheral side thereof.
d, transfer discharge parts 43a to 43d, cleaner 19a to
19d and primary charging units 44a to 44d are arranged.

With such a structure, first, a latent image of a yellow component color in the original image is formed on the photosensitive drum 1a of the first image forming section 41a by the latent image forming means 42a. The latent image is made a visible image with the yellow toner of the developing device 7a, and is transferred to the transfer material 15 at the transfer discharge unit 43a.
Is transcribed to.

While the yellow image is being transferred onto the transfer material 15 as described above, a latent image of a magenta component color is formed on the photosensitive drum 1b in the second image forming section 41b, and then the developing device 7b is operated. It is a visible image with magenta toner.
This visible image (magenta toner image) is transferred onto a predetermined position of the transfer material 15 when the transfer material 15 which has been transferred by the first image forming section 41a is carried into the transfer discharge section 42b. To be done.

The third and fourth steps are performed in the same manner as described above.
In the image forming portions 41c and 41d of the above, cyan and black images are formed, and the same transfer material 15 is formed.
Then, the cyan color and the black color are superimposed and transferred.
When such an image forming process is completed, the transfer material 15 is conveyed to the fixing device 23 and the image on the transfer material 15 is fixed. As a result, a multicolor image can be obtained on the transfer material 15. Each photoconductor drum 1a after the transfer is completed
The residual toner 1d is removed by the cleaners 19a to 19d and is used for the subsequent latent image formation.

In the image forming apparatus, the conveyor belt 46 is used to convey the transfer material 15, as shown in FIG.
In, the transfer material 5 is conveyed from the right side to the left side, and in the conveying process, the transfer material 5 passes through each of the transfer discharge sections 43a to 43d in each of the image forming sections 41a to 41d to be transferred.

In this image forming method, a transfer belt using a mesh of tetron fiber and a polyethylene terephthalate resin, a polyimide resin, as a transfer means for transferring the transfer material 15 from the viewpoint of ease of processing and durability.
A conveyor belt using a thin dielectric sheet such as urethane resin is used.

When the transfer material 15 passes through the fourth image forming portion 41d, a DC voltage is applied to the static eliminator 45, and the transfer material 15 is transferred.
Is discharged from the conveyor belt 46, then enters the fixing device 23, the image is fixed, and the sheet is discharged from the discharge port 50.

In this apparatus, each of the plurality of image forming sections is provided with an independent electrostatic latent image bearing member, and the transfer material is a belt type conveying means, and the electrostatic latent image bearing members are sequentially transferred. The electrostatic latent image carrier, which is configured to be sent to the transfer unit, is provided in common with the image forming unit, and the transfer material is a drum type conveying unit, and the transfer unit of the electrostatic latent image carrier is used. May be repeatedly sent to each color to receive the transfer of each color.

In the conveyor belt system of FIG. 6, since the volume resistance is high, the conveyor belt increases the charge amount in the process of repeating transfer several times as in the color image forming apparatus. For this reason, uniform transfer cannot be maintained unless the transfer current is sequentially increased for each transfer, but the toner of the present invention has excellent transferability, and therefore even if the charge on the conveyor belt increases each time transfer is repeated. With the same transfer current, the transferability of toner in each transfer can be made uniform, and a high-quality image of high quality can be obtained.

Further, FIG. 7 shows a schematic configuration diagram of another apparatus example for carrying out the image forming method of the present invention, which will be described below.

In FIG. 7, 44 is a primary charging section, 60 is a transfer drum, 61 is a gripper, 62 is a transfer charger, and 6
3a and 63b are separation chargers, 64 is a separation guide,
The same members as those in FIGS. 2 to 6 are denoted by the same reference numerals.

In the structure shown in FIG. 7, the electrostatic latent image formed on the photosensitive drum 1 by an appropriate means has developing devices 7a to 7a attached to the developing unit 24 which rotates in the direction of the arrow.
In the first developing device 7a in 7d, it is visualized by the toner. The color toner image on the photosensitive drum 1 is
It is transferred by the transfer charger 62 onto the transfer material 15 held on the transfer drum 60 by the gripper 61.
The transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer is collected by the cleaner 19 having a cleaning blade that contacts the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

A corona charger or a contact charger is used as the transfer charger 62. When a corona charger is used as the transfer charger 62, a voltage of −10 kV to +10 kV is applied and the transfer current is − It is 500 μA to +500 μA. A holding member is stretched on the outer peripheral surface of the transfer drum 60,
This holding member is composed of a film-like dielectric sheet such as a polyvinylidene fluoride resin film or polyethylene terephthalate. For example, a thickness of 100 μm to 20
A sheet having 0 μm and a volume resistance of 10 ¹² to 10 ¹⁴ Ω · cm is used.

Next, as the second color, the developing unit 24 rotates and the developing device 7b faces the photosensitive drum 1. Then, it is developed with the second toner in the developing device 7b, and this toner image is also transferred onto the same transfer material 15 as described above.

Further, the third and fourth colors are similarly processed. In this way, the transfer drum 60 is rotated a predetermined number of times while carrying the transfer material 15, and the toner images of a predetermined number of colors are transferred in multiple. The transfer current for electrostatic transfer is 1st color <2
It is preferable to increase the order of the color <third color <4th color in order to reduce the transfer residual toner remaining on the photosensitive drum 1.

The multi-transferred transfer material 15 is separated from the transfer drum 60 by the separation chargers 63a and 63b, fixed by the heating / pressurizing roller fixing device 23, and color-mixed at the time of fixing, whereby a full-color copy image is obtained. Becomes

FIG. 8 shows another example of an apparatus for carrying out the image forming method of the present invention, in which the four color toner images primarily transferred onto the intermediate transfer drum are secondarily transferred onto a transfer material all together. A schematic configuration diagram of an image forming apparatus using a transfer belt as a secondary transfer means is shown.

In the apparatus shown in FIG. 8, the developing devices 7a ...
Toners of respective colors of black, yellow, cyan, and magenta are introduced into 7d to develop the electrostatic latent image formed on the photosensitive drum 1, and the toner images of respective colors are transferred to the photosensitive drum 1.
Formed on. The photosensitive drum 1 is made of a-Se, Cds,
Photoconductive insulating material layer 7 such as ZnO ₂ , OPC, a-Si
It has 1b and is rotated in the direction of the arrow by a driving device (not shown). A photosensitive body having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used for the photosensitive layer 71a.

As the organic photosensitive layer, the photosensitive layer contains a charge generating substance and a substance having a charge transporting property in the same layer.
It may be a single layer type or a function-separated type photosensitive layer in which the charge transport layer contains a charge generation layer as a component. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one of preferred examples.

Polycarbonate resin, polyester resin, and acrylic resin are particularly preferable as the binder resin of the organic photosensitive layer because of good transferability and cleaning property, poor cleaning, toner fusion to the photoconductor, and filming of external additives. Hard to happen.

In the charging step, there are a method of non-contact with the photosensitive drum 1 using a corona charger and a contact type method using a roller or the like. In order to reduce the amount of ozone and generate ozone, a contact type as shown in FIG. 8 is preferably used.

The charging roller 10 has a basic core metal 10b and a conductive elastic layer 10a formed on the outer periphery thereof. The charging roller 10 is pressed against the surface of the photosensitive drum 1 with a pressing force and is driven to rotate as the photosensitive drum 1 rotates.

Preferred process conditions when the charging roller 10 is used are the same as those in the apparatus shown in FIG.

The toner image on the photosensitive drum 1 is transferred to the intermediate transfer drum 25 to which a voltage (for example, ± 0.1 ± 5 kV) is applied. The surface of the photosensitive drum 1 after the transfer is cleaned by a cleaner 19 having a cleaning blade.

The intermediate transfer drum 25 is arranged in parallel with the photosensitive drum 1 so as to be in contact with the lower surface of the photosensitive drum 1, and is arranged at the same peripheral speed as the photosensitive drum 1 in the counterclockwise direction indicated by the arrow. Rotate in the direction.

The first formed and carried on the surface of the photosensitive drum 1.
Color toner images are transferred to the photosensitive drum 1 and the intermediate transfer drum 25.
The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer drum 25 by the electric field formed in the transfer nip area by the applied transfer bias to the intermediate transfer drum 25 while passing through the transfer nip portion where the and are in contact with each other.

If necessary, the removable cleaning means 72 cleans the surface of the intermediate transfer drum 25 after the toner image is transferred to the transfer material 15. When there is a toner image on the intermediate transfer drum 25, the cleaning unit 72 uses the intermediate transfer drum 25 so as not to disturb the toner image.
Separated from the surface.

A transfer means is arranged in parallel with the intermediate transfer drum 25 so as to be in contact with the lower surface of the intermediate transfer drum 25. The transfer unit is, for example, a transfer roller or a transfer belt, and rotates in the clockwise direction indicated by an arrow at the same peripheral speed as the intermediate transfer drum 25. The transfer means 73 may be arranged so as to be in direct contact with the intermediate transfer drum 25, or a belt or the like may be arranged so as to be in contact between the intermediate transfer drum 25 and the transfer means.

When the transfer means is a transfer roller, the core metal at the center and the conductive elastic layer forming the outer periphery thereof are the basic components.

As the intermediate transfer drum and transfer roller,
Common materials can be used. By setting the volume specific resistance value of the elastic layer of the transfer roller to be smaller than the volume specific resistance value of the elastic layer 25b of the intermediate transfer drum 25, the voltage applied to the transfer roller can be reduced, and the transfer material 15 can be satisfactorily formed. It is possible to form a toner image and prevent the transfer material 15 from being wound around the intermediate transfer drum 25. Particularly, it is particularly preferable that the volume specific resistance value of the elastic layer 25b of the intermediate transfer drum 25 is 10 times or more than the volume specific resistance value of the elastic layer of the transfer roller.

The hardness of the intermediate transfer drum and transfer roller is
It is measured according to JIS K-6301. The intermediate transfer drum 25 used in the present invention is preferably composed of an elastic layer 25b belonging to the range of 10 to 40 degrees, while the hardness of the elastic layer of the transfer roller is the intermediate transfer drum 25.
It is preferable that the elastic layer 25b is harder than the elastic layer 25b and has a value of 41 to 80 degrees in order to prevent the transfer material 15 from being wound around the intermediate transfer drum 25. When the hardness of the intermediate transfer drum 25 and the transfer roller are opposite, a recess is formed on the transfer roller side, and the transfer material 15 is likely to be wound around the intermediate transfer drum 25.

In FIG. 8, below the intermediate transfer drum 25,
A transfer belt 73 is arranged. The transfer belt 73 is
It is wound around two rollers, that is, a bias roller 74 and a tension roller 75, arranged in parallel to the axis of the intermediate transfer drum 25, and is driven by a driving means (not shown). The transfer belt 73 is a tension roller 75.
Since the bias roller 74 side is configured to be movable in the arrow direction with the side being the center, the intermediate transfer drum 25
Can be contacted and separated from below in the direction of the arrow. The bias roller 74 includes a bias power supply 76 for secondary transfer.
Is applied with a desired secondary transfer bias, while the tension roller 75 is grounded.

Next, as the transfer belt 73, for example,
Carbon is dispersed in a thermosetting urethane elastomer to a thickness of about 300 μm and a volume resistivity of 10 ⁸ to 10 ¹² Ω · cm.
Fluorine rubber 20μ after controlling to (1kV applied)
A rubber belt whose m and volume resistivity are controlled to 10 ¹⁵ Ω · cm (when 1 kV is applied) is used. The outer diameter is 80
× A tube shape with a width of 300 mm.

A tension of about 5% is applied to the transfer belt 73 by the bias roller 74 and the tension roller 75 described above.

The transfer belt 73 is rotated at a constant speed or a peripheral speed different from that of the intermediate transfer drum 25. The transfer material 15 is conveyed between the intermediate transfer drum 25 and the transfer belt 73, and at the same time, the bias power source 76 applies a bias having a polarity opposite to that of the frictional charge of the toner to the transfer belt 73. The upper toner image is transferred to the surface side of the transfer material 15.

The same material as that of the charging roller can be used as the material of the transfer rotary member, and the preferable transfer process condition is that the contact pressure of the roller is 4.9 to 490 N.
/ M (5 to 500 g / cm), DC voltage is ± 0.2 to
± 10 kV.

For example, the conductive elastic layer 74b of the bias roller 74 is made of polyurethane or ethylene-propylene-diene terpolymer (E) in which a conductive material such as carbon is dispersed.
It is made of an elastic body having a volume resistance of about 10 ⁶ to 10 ¹⁰ Ωcm such as PDM). A bias is applied to the cored bar 74a by a constant voltage bias power source. The bias condition is preferably ± 0.2 to ± 10 kV.

Next, the transfer material 15 is conveyed to a fixing device 23 having a heating roller 18 containing a heating element such as a halogen heater and an elastic pressure roller 17 pressed against this with a pressing force. The toner image is transferred to the transfer material 1 by passing between the heating roller 18 and the pressure roller 17.
5 is fixed under heat and pressure. A method of fixing with a heater through a film may be used.

In the present invention, the peak top molecular weight (Mp), the number average molecular weight (Mn), and the weight average molecular weight (Mw) of the chromatogram obtained by GPC (gel permeation chromatography) of the toluene soluble content are as follows. Measured at.

First, as a sample preparation, the resin component in the sample was dissolved in toluene at room temperature so that the resin component was 0.4 to 0.6 mg / ml, and the resulting solution had a pore size of 0.2.
Filter with a μm solvent resistant membrane filter.

Next, the column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (TH
F) at a flow rate of 1 ml / min, and the THF sample solution is added to about 1
Inject 00 μl and measure. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of the calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, TSK standard polystyrene F-850, F-450, F-28 manufactured by Tosoh Corporation
8, F-128, F-80, F-40, F-20, F-
10, F-4, F-2, F-1, A-5000, A-2
The calibration curve was created using 500, A-1000, and A-500. The detectors are RI (refractive index) detector and UV.
The (ultraviolet) detector was used by being arranged in series. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns, and in the present invention, sh manufactured by Showa Denko KK is used.
odex GPC KF-801, 802, 803, 8
The measurement was performed using a combination of 04, 805, 806, 807 and 800P.

The apparatus is a high speed GPC HPLC8120.
GPC (manufactured by Tosoh Corporation) was used.

[0185]

EXAMPLES The present invention will be described in detail below, but the present invention is not limited thereto.

Polyester Resin Synthesis Example Various materials were weighed so that the molar ratios shown in Table 2 were obtained, and these were placed in a 2-liter four-necked flask, and a reflux condenser and a water separator were placed in this four-necked flask. An apparatus, a nitrogen gas introducing pipe, a thermometer and a stirrer were attached, and nitrogen was introduced into the flask from the nitrogen gas introducing pipe and heated by a mantle heater while stirring and reacting them. The reaction temperature at this time is 180 ° C to 240 ° C.
Met. Then, during this reaction, the reaction state was traced while measuring the acid value, and when the predetermined acid value was reached, the reaction was terminated to synthesize polyester resins (1) to (3). The reaction time at this time was 5 to 10 hours. The abbreviations in the table are as follows. EG: ethylene glycol PG: propylene glycol BPA-PO: polyoxypropylene (2,2) -2,
2-bis (4-hydroxyphenyl) propane BPA-EO: polyoxyethylene (2,2) -2,2
-Bis (4-hydroxyphenyl) propane TPA: terephthalic acid IPA: isophthalic acid FA: fumaric acid TMA: trimellitic acid

Table 2 shows the acid value, glass transition temperature and peak top molecular weight measured by GPC of the obtained polyester resin.

[0188]

[Table 2]

(Toner Production Example) Toner Production Example 1 (Binder Resin) Polyester Resin (1) 100 parts by mass (colorant) C.I. I. Pigment Blue 15:38 8 parts by mass (charge control agent) 5% by mass negative charge control agent (zinc compound of dialkyl salicylic acid) The above materials are sufficiently premixed by a Henschel mixer, and melt-kneaded by a twin-screw extruder, After cooling, it was roughly pulverized to about 1 to 2 mm using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. Further, the obtained finely pulverized product was classified to obtain toner particles (1) having a weight average particle diameter of 8.1 μm.

To 100 parts by mass of this toner particle (1), B
1.2 parts by mass of hydrophobized silica fine particles having an ET value of 350 m ² / g, a primary particle size of 7 nm, and a primary particle size of 3
Toner (1) was obtained by adding 0.6 parts by mass of calcium titanate having a particle size of 60 nm and a secondary particle size of 1.9 μm and mixing the mixture with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.).

Table 3 shows the physical properties of Toner (1).

Toner Production Example 2 Toner particles (2) having a weight average particle diameter of 9.4 μm were obtained in the same manner as in Toner Production Example 1 except that the polyester resin (2) was used as the binder resin.

To 100 parts by mass of the toner particles (2), B
0.1 parts by mass of hydrophobized silica fine particles having an ET value of 350 m ² / g, a primary particle size of 7 nm, and a primary particle size of 9
2.4 parts by mass of strontium titanate having a particle size of 50 nm and a secondary particle size of 2.1 μm was added and mixed with a Henschel mixer to obtain a toner (2).

Table 3 shows the physical properties of Toner (2).

Toner Production Example 3 Toner particles (3) having a weight average particle diameter of 6.4 μm were obtained in the same manner as in Toner Production Example 1 except that the polyester resin (3) was used as the binder resin.

To 100 parts by mass of this toner particle (3), B
3.0 parts by mass of untreated silica fine particles having an ET value of 50 m ² / g, a primary particle size of 40 nm, and a primary particle size of 410
nm, and 1.8 parts by mass of barium titanate having a secondary particle size of 2.0 μm were added and mixed with a Henschel mixer to obtain a toner (3).

Table 3 shows the physical properties of Toner (3).

Toner Production Example 4 (Binder resin A) Polyester resin (1) 80 parts by mass (Binder resin B) Styrene / n-butyl acrylate copolymer (mass ratio 84/16) (Mn = 34100 Mw / Mn = 3.0) 20 parts by mass (colorant) C.I. I. Pigment Blue 15: 3 10 parts by mass (charge control agent) Negatively charged property control agent (aluminum compound of dialkyl salicylic acid) 5 parts by mass The above materials are sufficiently premixed by a Henschel mixer, and melt-kneaded by a twin-screw extruder, After cooling, it was roughly pulverized to about 1 to 2 mm using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. Further, the obtained finely pulverized product was classified to obtain toner particles (4) having a weight average particle diameter of 4.3 μm.

To 100 parts by mass of this toner particle (4), B
0.9 parts by mass of hydrophobized silica fine particles having an ET value of 350 m ² / g, a primary particle size of 7 nm, and a primary particle size of 1
Toner (4) was obtained by adding 6.2 parts by mass of silicon carbide having a particle diameter of 500 nm and existing as primary particles on the surface of the toner particles, and mixing with a Henschel mixer.

Table 3 shows the physical properties of Toner (4).

Toner Production Example 5 Toner (5) was obtained in the same manner as in Toner Production Example 1 except that the fine particles to be externally added were only hydrophobic silica fine particles.

Table 3 shows the physical properties of Toner (5).

Toner Production Example 6 A weight average particle diameter of 1 was obtained in the same manner as in Toner Production Example 1 except that the pulverization conditions and classification conditions of the toner were changed.
Toner particles (6) of 3.3 μm were obtained.

To 100 parts by mass of the obtained toner particles (6), 2.1 parts by mass of only strontium titanate having a primary particle size of 950 nm and a secondary particle size of 2.1 μm was added and mixed with a Henschel mixer. Toner (6) was obtained. )
Got

Table 3 shows the physical properties of Toner (6).

Toner Production Example 7 100 parts by weight of the toner particles (1) obtained in Toner Production Example 1 had a BET value of 50 m ² / g and a primary particle diameter of 40 nm.
1.2 parts by mass of untreated silica fine particles, and 1.0 part by mass of titanium oxide having a primary particle diameter of 15 nm and existing as primary particles on the surface of the toner particles are mixed with a Henschel mixer to obtain a toner (7 ) Got.

Table 3 shows the physical properties of Toner (7).

[0208]

[Table 3]

<Example 1> Using the obtained toner (1), image evaluation was performed according to the following methods.

Evaluation of Discontinuous Micro Streaks An A4 CLC paper (manufactured by Canon; 80; temperature 23 ° C., humidity 10% RH) was used using an image forming apparatus as shown in FIG.
g / m ² ) to continuously create a character image with an image density of 2% 15
000 sheets were printed. Immediately after printing the 1st, 50th, 5000th, and 15000th images, one halftone image with a 15% image density was printed, and the images were used as evaluation images.

The image forming apparatus will be described below.

FIG. 9 is a schematic view of a modified laser beam printer (“LBP-840” manufactured by Canon Inc.) which utilizes a non-magnetic one-component system contact development type electrophotographic process. In this example, an apparatus obtained by modifying the following parts (a) to (h) was used. The reference numerals in the figure are the same as those in FIGS. (A) Change the process speed to 150 mm / s. (B) The charging method of the apparatus was direct charging by contacting a rubber roller, and the applied voltage was a DC component (-1200V). (C) A medium resistance rubber roller (diameter 16 mm, hardness ASKER-C 45 degrees, resistance 1) made of a silicone rubber in which carbon black is dispersed is used as a toner carrier (developing roller) 2.
0 ⁵ Ω · cm) and abutted on the photoconductor drum 1. (D) The rotational peripheral speed of the toner bearing member was in the same direction at the contact portion with the photosensitive drum 1, and was driven so as to be 155% of the rotational peripheral speed of the photosensitive drum 1. (E) The photoconductor was changed to the following.

As the photosensitive drum 1 used here, Al
A cylinder was used as a base body, and layers having the following constitution were sequentially laminated by dip coating to prepare a photosensitive drum. (1) Conductive coating layer: Mainly composed of a powder of tin oxide and titanium oxide dispersed in a phenol resin. Film thickness 15μ
m. (2) Undercoat layer: Mainly composed of modified nylon and copolymer nylon. The film thickness is 0.6 μm. (3) Charge generation layer: Mainly composed of a butyral resin in which a titanyl phthalocyanine pigment having absorption in a long wavelength region is dispersed. The film thickness is 0.6 μm. (4) Charge transport layer: Mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20000 according to Ostwald viscosity method) at a mass ratio of 8:10. Film thickness 20 μm. (F) As a means for applying toner to the toner carrier, an application roller 9 made of urethane foam rubber is provided in the developing device 7 and brought into contact with the toner carrier. A voltage of about −550V is applied to the coating roller 9. (G) In order to control the coat layer of the toner on the toner carrier, a stainless steel blade (blade (1)) laminated with polyamide elastomer (film thickness 50 μm) was used. When the universal hardness of the blade (1) was measured using a hardness scale Fischer Scope H100 manufactured by Fischer GmbH, Germany, it was 15.3 N / mm.
^{Was 2} . (H) The applied voltage at the time of development was only the DC component (-450V).

The electrophotographic apparatus was modified and the process conditions were set as follows so as to be compatible with the modification of these process cartridges.

The modified device uses a roller charger (only DC is applied) and uses the photosensitive drum 1 which is an electrostatic latent image carrier.
To be uniformly charged. After charging, an electrostatic latent image is formed by exposing the image portion with a laser beam 22 to form a visible image with toner, and then the toner image is transferred to the transfer material 15 by the roller 16 to which a voltage of +700 V is applied. To have.

Regarding the charging potential of the photosensitive drum 1, the dark portion potential was -580V and the light portion potential was -150V.

The evaluation was performed based on the following criteria. a: Very good (no discontinuous micro streaks are observed) b: Good (discontinuous micro streaks are present at 1 location) c: Practical use (Discontinuous micro streaks are observed at 1 to 5 locations, but practical Is not a problem) d: Not practical (discontinuous micro streaks are observed at 5 or more locations)

<Examples 2 to 4> Images were evaluated in the same manner as in Example 1 except that Toners (1) were replaced with Toners (2) to (4).

The evaluation results are shown in Table 4.

<Example 5> Image evaluation was performed in the same manner as in Example 1 except that the blade (2) (surface layer resin: nylon 6 (film thickness 20 μm)) was used as the toner layer regulating member.

The evaluation results are shown in Table 4.

Example 6 A blade layer (3) (surface layer resin: polypropylene (film thickness 90 μm)) was used as a toner layer regulating member.
Image evaluation was performed in the same manner as in Example 1 except that

Table 4 shows the evaluation results.

Comparative Examples 1 and 2 Using toner (5) and toner (6) instead of toner (1), image evaluation was performed in the same manner as in Example 1.

The evaluation results are shown in Table 4.

<Comparative Example 3> The toner layer regulating member is the blade (4) (surface layer resin: polyurethane (film thickness 100 μm)).
The image evaluation was performed in the same manner as in Example 1 except that the toner (7) was used instead of the toner (1).

The evaluation results are shown in Table 4.

<Comparative Example 4> The toner layer regulating member is the blade (5) (surface layer resin: phenol resin (thickness 30 μm)).
Image evaluation was performed in the same manner as in Example 1 except that

The evaluation results are shown in Table 4.

[0230]

[Table 4]

[0231]

As described above, according to the present invention,
In the non-magnetic one-component contact developing method, discontinuous fine lines do not occur, and high-quality image formation is realized for a long period of time.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing discontinuous minute stripes.

FIG. 2 is an explanatory diagram of a toner layer restriction member in the image forming method of the present invention.

FIG. 3 is a schematic configuration diagram of an example of an apparatus for performing the image forming method of the present invention.

FIG. 4 is a schematic configuration diagram of another example of an apparatus for carrying out the image forming method of the present invention.

FIG. 5 is a schematic configuration diagram of another example of an apparatus for carrying out the image forming method of the present invention.

FIG. 6 is a schematic configuration diagram of another example of an apparatus for carrying out the image forming method of the present invention.

FIG. 7 is a schematic configuration diagram of another example of an apparatus for carrying out the image forming method of the present invention.

FIG. 8 is a schematic configuration diagram of another example of an apparatus for carrying out the image forming method of the present invention.

FIG. 9 is a schematic configuration diagram of an image forming apparatus used in an embodiment of the present invention.

[Explanation of symbols]

1, 1a to 1d Photosensitive drum 2 Development sleeve 3 Elasticity regulation blade 4 toner 5 Toner container 6 Presser plate 7, 7a to 7d Developing device 9 Application roller 10 charging roller 10a conductive elastic layer 10b core metal 11-13 Bias power supply 14 exposure 15 Transfer material 16 Transfer member 17 Pressure roller 18 Heating roller 19, 19a-19d cleaner 21 Light source device 22 Laser light 23 Fixing device 24, 51 Development unit 25 Intermediate transfer drum 25a conductive support 25b elastic layer 26 Bias power supply 27 Transfer material tray 28 Secondary transfer device 30 Intermediate transfer belt 31 Laura 32 Primary transfer roller 33a Secondary transfer opposing roller 33b Secondary transfer roller 34-36 Bias power supply 39 Charging member for cleaning 41a to 41d Image forming unit 42a-42d latent image forming means 43a to 43d Transfer discharging unit 44, 44a to 44d Primary charging unit 45 Static eliminator 46 conveyor belt 48 Adsorption charger 49a to 49d Separating and discharging unit 50 outlet 60 transfer drum 61 gripper 62 Transfer charger 63a, 63b Separation charger 64 Separation guide 71a Photosensitive layer 71b Photoconductive insulating material layer 72 Cleaning means 73 Transfer belt 74 Bias roller 74a core 74b Conductive elastic layer 75 Tension roller 76 bias power supply

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 507 G03G 15/08 507L (72) Inventor Satoshi Handa 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc. (72) Inventor Yasuhiro Hashimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H005 AA01 AA08 CA08 CA17 CB07 CB13 EA05 EA07 2H030 AB02 AD01 BB23 BB24 BB33 2H077 AD06 AD13 AD23 BA10 DB14 EA14 EA24 FA21 GA13

Claims (21)

[Claims] 1. A toner for forming an image using a non-magnetic one-component developing method, wherein a toner regulating member is brought into contact with the surface of a toner carrier to regulate a toner layer on the toner carrier. Layer forming step: The toner layer carried on the surface of the toner carrying member is brought into contact with the surface of the electrostatic latent image carrying member to develop the electrostatic latent image to form the toner image on the electrostatic latent image carrying member. Developing step to form;
And the toner regulating member is 9.5 N / mm ² or more and 100 N / mm ² or more.
The toner has a universal hardness of less than mm ² , the toner contains at least a colorant and a binder resin, the toner has a number average particle diameter of 4 μm or more and less than 12 μm, and the toner particles have at least silica fine particles. And a toner having at least the inorganic fine powder A having a particle size larger than the primary particle size of the silica fine powder on the surface of the toner particles. 2. Particles having a particle size of 0.6 to 2.0 μm as measured by a flow-type particle image measuring device are 50.
The toner according to claim 1, which is 0% by number or more and less than 70.0% by number. 3. The toner according to claim 1, wherein the binder resin contains a crosslinked polyester resin. 4. The toner according to claim 1, wherein the toner layer regulating member has an elastic layer containing a nitrogen-containing compound on its surface layer. 5. The toner according to claim 1, wherein the inorganic fine powder A has a shape in which particles larger than the primary particle diameter of the silica fine powder are aggregated. 6. The inorganic fine powder A is a fine powder selected from the following compound group B: 1.
The toner according to any one of 1. Compound group B: calcium titanate, strontium titanate, barium titanate 7. The silica fine powder is contained in the toner particles in an amount of 0.01.
7. The inorganic fine powder A is contained in an amount of from 0.01% by mass to less than 2.0% by mass, and the inorganic fine powder A is contained in the toner particles in an amount of from 0.01% by mass to less than 2.0% by mass.
The toner according to any one of 1. 8. An image forming method using a non-magnetic one-component developing method, wherein a toner layer forming step of bringing a toner regulating member into contact with the surface of the toner carrier to regulate the toner layer on the toner carrier. A developing step of developing the electrostatic latent image to form a toner image on the electrostatic latent image bearing member by bringing the toner layer carried on the surface of the toner bearing member into contact with the surface of the electrostatic latent image bearing member. ;
At least 9.5 N / mm ^{2 and} more than 100 N /
The toner has a universal hardness of less than mm ² , the toner contains at least a colorant and a binder resin, the toner has a number average particle diameter of 4 μm or more and less than 12 μm, and the toner particles have at least silica fine particles. And at least the inorganic fine powder A having a particle diameter larger than the primary particle diameter of the silica fine powder on the surface of the toner particles. 9. A toner having a particle size of 0.6 to 2.0 μm measured by a flow type particle image measuring device is 50.0% by number or more and less than 70.0% by number. The image forming method according to claim 8. 10. The image forming method according to claim 8, wherein the binder resin contains a crosslinked polyester resin. 11. The image forming method according to claim 8, wherein the toner layer regulating member has an elastic layer containing a nitrogen-containing compound as a surface layer thereof. 12. The image forming method according to claim 8, wherein the inorganic fine powder A has a shape in which particles larger than the primary particle diameter of the silica fine powder are aggregated. 13. The image forming method according to claim 8, wherein the inorganic fine powder A is a fine powder selected from the following compound group B. Compound group B: calcium titanate, strontium titanate, barium titanate 14. Silica fine powder in toner particles is 0.0
9. The content of the inorganic fine powder A is 1% by mass or more and less than 2.0% by mass, and the inorganic fine powder A is contained in the toner particles by 0.01% by mass or more and less than 2.0% by mass. 14. The image forming method according to any one of 13 above. 15. A process cartridge used in a non-magnetic one-component developing method, comprising a toner layer forming step of bringing a toner regulating member into contact with the surface of the toner carrier to regulate the toner layer on the toner carrier; A developing step of developing the electrostatic latent image to form a toner image on the electrostatic latent image carrier by bringing the toner layer carried on the surface of the carrier into contact with the surface of the electrostatic latent image carrier;
At least 9.5 N / mm ^{2 and} more than 100 N /
The toner has a universal hardness of less than mm ² , the toner contains at least a colorant and a binder resin, the toner has a number average particle diameter of 4 μm or more and less than 12 μm, and the toner particles have at least silica fine particles. And a process cartridge comprising at least an inorganic fine powder A having a particle size larger than the primary particle size of the silica fine powder on the surface of the toner particles. 16. A toner having a particle size of 0.6 to 2.0 μm as measured by a flow particle image measuring device of toner is 50.0% by number or more and less than 70.0% by number of the total particles. The process cartridge according to claim 15. 17. The process cartridge according to claim 15, wherein the binder resin contains a crosslinked polyester resin. 18. The process cartridge according to claim 15, wherein the toner layer regulating member has an elastic layer containing a nitrogen-containing compound on its surface layer. 19. The process cartridge according to claim 15, wherein the inorganic fine powder A has a shape in which particles larger than the primary particle diameter of the silica fine powder are aggregated. 20. The process cartridge according to claim 15, wherein the inorganic fine powder A is a fine powder selected from the following compound group B. Compound group B: calcium titanate, strontium titanate, barium titanate 21. The silica fine powder is 0.0 in the toner particles.
16. The content of the inorganic fine powder A is 1% by mass or more and less than 2.0% by mass, and the inorganic fine powder A is contained in the toner particles by 0.01% by mass or more and less than 2.0% by mass. 21. The process cartridge according to any one of 20.