JP2670468B2 - Developer for developing electrostatic image, image forming method and heat fixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer for developing an electrostatic latent image in an image forming method such as electrophotography,
The present invention relates to an image forming method and a method of heating and fixing a toner image.

[0002]

2. Description of the Related Art The electrophotographic method is described in US Pat.
As described in US Pat. No. 7,691 and the like, a number of methods are known. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. In this method, a latent image is developed with toner, and the toner image is transferred to a recording material such as paper, if necessary, and then fixed by heating, pressure, heating / pressurizing or solvent vapor to obtain a copy. Conventionally, various methods have been proposed as a method of developing using toner or a method of fixing a toner image, and a method suitable for each image forming process is adopted. In recent years, high speed copying and high image quality have been required for such electrophotography.

In general, as a method for producing a toner, a thermoplastic resin is melt-mixed with a colorant such as a dye or a pigment and / or an additive such as a charge control agent, and the mixture is uniformly dispersed and then finely pulverized. A method for producing a toner having a desired particle size by classification is known.

Since the toner produced by the pulverization method generally has an indefinite shape, there is a limit in faithful reproduction of the latent image. In order to improve the image quality in the pulverization method, it is necessary to pulverize the particles to a smaller particle size. However, reducing the particle size requires more energy and tends to lower the toner yield.

Further, in the toner obtained by the pulverization method,
There are restrictions when adding a releasing material such as wax. That is, in order to obtain a sufficient level of dispersibility of the release material, it must be dissolved and not in a liquid state at the kneading temperature with the resin, and the content of the release material should be a certain amount or less. And so on. Due to such restrictions, there is a limit to the fixability of the toner by the pulverization method.

In contrast to these irregular toners, spherical toners have been proposed. For example, Japanese Patent Publication No. 56-13945 proposes a method of obtaining a spherical toner by a melt spray method. In Japanese Patent Publication No. 57-51676,
A method has been proposed in which a small amount of an organic solvent is added to an amorphous toner and a stirring process is performed under cooling to obtain a spherical toner. Further, JP-B-36-10231 and JP-A-59-231 are disclosed.
JP-A-53856, JP-A-59-61842 and the like disclose a method of obtaining a spherical toner by using a suspension polymerization method.

Since these spherical toners have a uniform shape, they tend to adhere faithfully to a latent image. In particular, in the edge portion of the latent image, minute disturbance disappears and the image quality becomes high.
Furthermore, when a spherical toner is obtained by the suspension polymerization method, it is easy to reduce the toner particle size, and it becomes suitable for higher image quality.

Further, the toner produced by the suspension polymerization method (hereinafter referred to as a polymerized toner) is more likely to have a capsule structure function than the amorphous toner obtained by the pulverization method, and many waxes are encapsulated therein. And good fixability and offset resistance can be expected.

On the other hand, the spherical toner tends to deteriorate in its characteristics even if various additives are added, and it is difficult to obtain a toner having sufficient durability. There are some reports that the subsequent toner cleaning tends to be insufficient.

Further, in the suspension polymerization method, a substantially incompatible polymerizable monomer system is dispersed in a dispersion medium typified by water and polymerized to form toner particles. . To obtain toner particles with a sharp particle size distribution,
It is a very important issue how to keep the droplets (polymerizable monomer composition particles) of the polymerizable monomer composition suspended in the liquid dispersion medium stable to a certain diameter during the polymerization process. Becomes

In order to solve this problem, a suitable interfacial tension between the droplets of the polymerizable monomer composition and the interface of the dispersion medium is provided without adversely affecting the environmental characteristics (for example, moisture resistance) of the toner. The search for a dispersion stabilizer and its processing step are extremely important.

In recent years, copying machines or printers have begun to be used not only in office processing copiers for simply copying original documents, but also in the field of printers as computer outputs or personal copies for individuals.

For this reason, specifications such as small size, light weight, and low power consumption are being pursued, and machines are now being configured with simple elements. For example, as a method for developing an electrostatic latent image, there are a two-component developing method in which a toner and a carrier are mixed and used, and a one-component developing method in which only a magnetic toner is used.

JP-A-58-116559, JP-A-60-120368, JP-A-63-271371
The non-magnetic one-component developing method disclosed in Japanese Unexamined Patent Publication (Kokai) No. HEI 7-123 is noted as a developing method for solving the above-mentioned problems.

In such a non-magnetic one-component developing method,
The developer is coated on the developer carrier using a blade or the like. The developer is charged by friction with the blade or the surface of the developer carrying member. If the coat layer is thick, there are developers that cannot be sufficiently charged, which causes fog and scattering. Therefore, the developer must be coated in a thin layer. Therefore, the blade must be pressed against the developer carrier with sufficient pressure, and the force applied to the developer at this time is applied to the developer in the two-component developing method or the one-component developing method using the magnetic toner. Greater than power. For this reason, the developer is likely to deteriorate, and image deterioration such as fog and a decrease in density is likely to occur.

The developer used in the non-magnetic one-component developing method is required to have high mechanical strength and thermal strength. However, simply increasing these strengths
This leads to an increase in the thermal energy required for fixing, which violates the demand for low power consumption. As described above, in the non-magnetic one-component developing method, high performance is required for both developability and fixability.

As a conventional method for fixing a visible image of a toner to a recording material, an unfixed toner is fixed by using a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and pressing against the heating roller. A hot roll fixing system in which a recording material holding a visible image is heated while being nipped and conveyed is often used. Further, a belt fixing system described in US Pat. No. 3,578,797 is known.

However, in such heat roll fixing, there is a time (so-called wait time) during which the image forming operation is prohibited until the heat roller reaches a predetermined temperature. It is necessary to maintain the heating roller at an optimum temperature in order to prevent improper fixing due to the temperature of the heating roller fluctuating due to passage of the recording material or other external factors, and transfer of toner to the heating roller, so-called offset phenomenon. There is
For this purpose, it is necessary to increase the heat capacity of the heating roller or the heating body, which requires a large amount of electric power and causes a temperature rise inside the image forming apparatus. Since the roller has a constant temperature, when the recording material passes through the heating roller and is discharged, the recording material and the toner on the recording material are slowly cooled, so that the toner has a high adhesiveness and the curvature of the roller is also increased. In some cases, a paper jam may occur due to an offset or winding of a recording material. The high temperature heating roller is in direct contact with the hand, which may cause a safety problem or require a protective member.

Even in the belt fixing method described in US Pat. No. 3,578,797, the above-mentioned problem of heat roll fixing has not been fundamentally solved.

In Japanese Patent Laid-Open No. 63-313182, a fixing device for heating a toner image to a recording material through a heat-resistant sheet which is moved by a heating element of a low heat capacity which is energized and heated in a pulsed manner is described. An image forming apparatus having a short wait time and low power consumption has been proposed.
Further, in JP-A-1-187582, in a fixing device that heat-fixes a visible image of a toner on a recording material via a heat resistant sheet, the heat resistant sheet has a heat resistant layer and a release layer or a low resistance layer. Therefore, a fixing device that effectively prevents the offset phenomenon has been proposed.

However, in order to realize a fixing method that has a short wait time and low power consumption while achieving excellent fixability of a toner-visible image to a recording material and prevention of offset, it is necessary to use a fixing device as described above. In addition, there is a long-awaited demand for a suitable toner because of the characteristics of the toner.

[0022]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic charge image, an image forming method and a heat fixing method which solve the above problems.

An object of the present invention is to provide a long-term durability.
An object of the present invention is to provide a developer for developing an electrostatic charge image, which contains a toner with little deterioration of an external additive and little change in performance and excellent durability.

A further object of the present invention is to provide a developer for developing an electrostatic charge image containing a toner excellent in fixing property and blocking resistance.

A further object of the present invention is to provide a developer for developing an electrostatic charge image containing a toner excellent in charge stability and storage stability.

A further object of the present invention is to provide an electrostatic charge image developing developer containing a toner having high image density, excellent fine line reproducibility and excellent highlight reproducibility.

A further object of the present invention is to provide a developer for developing an electrostatic charge image, which can preferably cope with high speed.

A further object of the present invention is to provide a developer for developing an electrostatic charge image, which is preferably used in a full-color image forming method or a multi-color image forming method.

Further, it is an object of the present invention to provide a developer for developing an electrostatic charge image in which spent of a carrier is less likely to occur.

An object of the present invention is to provide an image forming method which has a high image density even when used for a long time, does not cause image deterioration such as fog, and has excellent fixability in a non-magnetic one-component developing method. Especially.

An object of the present invention is to provide a heating and fixing method in which the wait time is substantially short or the time is extremely short, the power consumption is low, the offset phenomenon does not occur, and the toner image is well fixed on the recording material. Is to provide.

It is an object of the present invention to provide a heat fixing method which does not require a heat resistant special bearing by not using a high temperature rotating roller.

An object of the present invention is to provide a heat fixing method which is excellent in safety or does not require a protective member by having a fixing device structure which does not directly touch the high temperature body.

[0034]

According to the present invention, there is provided a developer for developing an electrostatic charge image containing a toner produced by a suspension polymerization method, wherein the toner contains 5 to 30% by weight of a material having a low softening point. The toner contains 0.005 to 0.2% by weight of calcium phosphate based on the toner, and the toner particles have a maximum inscribed circle having a radius r and a minimum circumscribed circle having a radius R with respect to a projection surface. It is a toner that satisfies the relationship of 1.00 <R / r <1.20 with respect to the circle, and between the peripheral length L of the projection surface and the circumferential length of 2πr of the inscribed circle. The present invention relates to a developer for developing an electrostatic charge image, wherein irregularities satisfying a relation of 01 <L / 2πr <2.00 are formed on toner particles.

[0035]

Further, according to the present invention, a magnetic brush formed of toner and magnetic particles is provided on a developer carrier, and a bias electric field formed of an AC component and a DC component is applied to the developer carrier. And the volume ratio of the magnetic particles is 1 in the developing area defined by the latent image carrier and the developer carrying member.
In an image forming method in which a magnetic brush is formed so as to be 0 to 40% and a latent image is developed, the toner has toner particles produced by a suspension polymerization method and has a low softening point substance of 5 to 30%. The toner contains 0.005 to 0.2% by weight of calcium phosphate based on the toner, and the toner particles have a maximum inscribed circle with a radius r and a radius R with respect to the projection surface. The toner satisfies the relationship of 1.00 <R / r <1.20 between the minimum circumscribed circle and the peripheral length L of the projection surface and the circumferential length 2πr of the inscribed circle. The present invention relates to an image forming method, wherein irregularities satisfying a relationship of 1.01 <L / 2πr <2.00 are formed on toner particles.

Further, the present invention provides an image forming method for developing a latent image with a non-magnetic one-component toner in a developing area between a latent image carrier and a developer carrier facing the latent image carrier. A supply roller for supplying the toner and a developer coating blade provided on the downstream side of the supply roller are in pressure contact with the developer carrier, and the toner produced by a suspension polymerization method Wherein the toner contains 5 to 30% by weight of a low softening point substance, and the toner has 0.005 to 0.2% by weight of calcium phosphate based on the toner; A toner satisfying the relationship of 1.00 <R / r <1.20 between the maximum inscribed circle of radius r and the minimum circumscribed circle of radius R with respect to the projection surface, and the periphery of the projection surface. Between the length L and the circumference length 2πr of the inscribed circle, 1 The present invention relates to an image forming method, wherein irregularities satisfying the relationship of 0.01 <L / 2πr <2.00 are formed on the toner particles.

Further, the present invention comprises a heating element and a pressing member for bringing a recording material into close contact with the heating element via a film,
In the method of heating and fixing the visible image of the toner on the recording material,
The toner is a toner produced by a suspension polymerization method, the toner contains 5 to 30% by weight of a low softening point substance, and the toner is 0.005 to 0.
It has 2% by weight of calcium phosphate, and the toner particles are 1.00 <R / r <1.20 between the maximum inscribed circle of radius r and the minimum circumscribed circle of radius R with respect to the projection surface. a toner satisfying the relationships, and, between the circumferential length 2.pi.r inscribed circle with peripheral length L of the projection surface, irregularities satisfying the relation of 1.01 <L / 2πr <2.00 toner The present invention relates to a heat fixing method characterized by being formed on particles.

The present inventors improved the fixability by providing the toner produced by the suspension polymerization method with concave portions on the surface of the toner particles and further having a capsule structure encapsulating a wax having a low melting point. By improving the blocking resistance and the durability of many sheets, and controlling the remaining amount of the dispersion stabilizer adhering to the surface of the toner particles, it is possible to obtain a toner with excellent charging stability and storage stability. It has been found.

The present inventors have found that the deterioration in durability and poor cleaning when various additives are used in combination with the spherical toner are mainly caused by the shape of the toner.

That is, if the shape of the toner particles is spherical,
For example, between toner and toner, between toner and carrier, between toner and sleeve, it is more easily rubbed than irregular toner, and as a result, an additive that adheres to the surface of toner particles and can move freely is embedded in the surface of toner particles. It tends to be adhered and adhered, its function is apt to be impaired, and durability and cleaning property are likely to be deteriorated.

Based on the above findings, the present invention was obtained by further studies. That is, it has been found that by forming a plurality of appropriate concave portions on the surface of the toner particles, the durability of various external additives is prevented from deteriorating, and cleaning can be efficiently performed by counter blade cleaning. Further, with the toner of the present invention, a high quality image can be obtained.

In the present invention, as the external additive, a fluidity-imparting agent,
It is preferable to use at least one of a lubricant and an abrasive.

When the fluidity-imparting agent is used, the van der Waals force acting on the toner is weakened, and the toner behaves faithfully to the Coulomb force. As a result, the toner easily moves from the developer carrying member such as the developing sleeve to the latent image on the photosensitive member, and a high image density can be obtained. Moreover, since the latent image can be faithfully developed, a developed image without fog can be obtained. Further, the use of the fluidity imparting agent facilitates toner replenishment. In the case of a two-component developer, the mixing property with the magnetic particles is improved, so
The charging of the toner also becomes good.

In general, the smaller the particle size of these fluidity imparting agents, the higher the fluidity imparting ability. The fluidity-imparting agent is
When used in a conventional spherical toner, since it has a small particle size, it is easily embedded in the toner and the effect of imparting fluidity is easily lost.

On the other hand, the present inventors have found that the toner produced by the suspension polymerization method, in which the fluidity imparting effect is less likely to deteriorate by combining the toner having the concave portion and the fluidity imparting agent. I found that it became toner.

Further, if the toner is made to have a small particle size in order to obtain a high quality toner image, it becomes difficult to clean the toner, and the toner tends to appear as a cleaning failure on the image. In the present invention, since the additive is not easily deteriorated by providing the toner with the concave portion and the adhesion to the surface of the photoconductor is reduced for a long period of time, cleaning is easy even when the toner has a small particle size. is there.

As described above, the toner particles in the present invention preferably have a plurality of concave portions partially on the surface. Further, the maximum inscribed circle of radius r and the minimum circumscribed circle of radius R with respect to the projection surface of the toner particles preferably satisfy 1.00 <R / r ≦ 1.20. More preferably, 1.02 <R / r ≦ 1.15 is preferable.

If R / r is large, the shape is in a direction away from the sphere, and if it exceeds 1.20, it is too far from the sphere, which is not preferable. The weight average particle diameter of these toners is preferably 3 to 12 μm.

Further, in the present invention, it is preferable that the peripheral length L of the projection surface and the circumferential length 2πr of the inscribed surface satisfy the relationship of 1.01 <L / 2πr <2.00. More preferably, 1.02 <L / 2πr <1.50 is preferable.

When L / 2πr is less than 1.01, there are almost no recesses, while when it is greater than 2.00, there are many fine micro recesses or recesses with a large drop. , Not preferable. Of these, in the former case, the concave portions are too small, and it is difficult to exert the effects. In the latter case, the actual shape approaches an irregular shape,
It becomes difficult to obtain high image quality, and pulverization easily occurs in the developing device.

The projection surface of the toner particles in the present invention means
It means an image obtained by using an electron microscope and focusing on the outline of the toner particles at least 2000 times or more (preferably 5000 times). Further, using Luzex 5000, the radius r of the inscribed circle and the radius R of the circumscribed circle are obtained as shown in FIG. 3, and the peripheral length L is obtained as shown in FIG.

At least 5 such toner particle images are
It is preferable that R, r, and L are measured for 0, preferably 100 or more, and the average value thereof satisfies the above relationship.

The toner of the present invention has a concave portion on the surface. An example of the surface shape is shown in FIG. Such recesses increase the number of contact points between the toner particles, but reduce the pressure at each contact, suppress the embedding of the additive in the toner particles, and improve the blocking resistance.

Generally, by adding a fluidity-imparting agent to the toner, the fluidity-imparting agent serves as a spacer, and the blocking resistance may be improved. However, as described above, various additives such as a fluidity imparting agent, when used in a spherical toner produced by a usual suspension polymerization method,
Additives tend to stick to the toner surface due to stress such as stirring, and a phenomenon that the function of the additives is hindered tends to occur.

On the other hand, in the present invention, the depressions on the toner surface prevent deterioration of the additive, so that good blocking resistance can be maintained for a long time.

Further, the toner of the present invention preferably has a surface layer portion 1 (A phase) and a central portion 2 (B phase) as shown in FIG. 2, and is divided into two phases by a clear interface. preferable. By having such a capsule-like structure and functionally separating the surface layer portion 1 and the central portion 2, a suitable toner design is possible. Specifically, a high-softening point resin is used for the surface layer to obtain a toner having blocking properties and strong resistance to a stirring force in a developing device. At the same time, an excellent toner can be obtained. Further, if a releasing material having a low melting point is contained in the central portion, it can be exuded by the pressure applied during fixing, and the offset property can be remarkably improved. The charge controllability may be mainly given to the surface layer.

Since the present invention has a firmer two-layer structure than the pseudocapsule proposed in Japanese Patent Publication No. 1-53786, etc., the substance inside oozes out to the surface layer in a normal state. Hateful. Therefore, the phenomenon that the low softening point substance inside contaminates the carrier and the developing sleeve is remarkably improved. In particular, when the low softening point substance is contained in a large amount, it functions effectively.

Specifically, at least two resin components of component A and component B are contained in the range of A: B = 50: 50 to 95: 5, and the phase mainly composed of component A and the component B mainly composed. It has a structure separated from the phase to be. The phase mainly composed of the component A is the surface layer, and the phase mainly composed of the component B is present in the central part. As described above, a preferable combination is obtained when the phase mainly composed of the component A has a high softening point and the phase mainly composed of the component B has a low softening point. A combination in which the phase mainly containing A and the phase mainly containing B are phase-separated as the suspension polymerization proceeds is preferable.

The preferred molecular weight of the component A is 5,000 to 200,000 in terms of weight average molecular weight (Mw) by gel permeation chromatography (GPC), and the melting characteristic of the component A is 65 at the outflow starting point by a flow tester. -100 ° C is preferred.

The component A constituting the surface layer of the toner is produced from, for example, the following polymerizable monomers. For example, styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-methylstyrene
Styrene-based monomers such as ethylstyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-acrylate
Ethylhexyl, stearyl acrylate, acrylic acid 2
-Acrylic acid esters such as chloroethyl, phenyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid 2 -Methacrylic acid esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate;
And monomers such as acrylonitrile, methacrylonitrile, and acrylamide.

These polymerizable monomers may be used alone or in combination. Among the above-mentioned polymerizable monomers, it is preferable to use styrene or a styrene derivative alone, or to use a mixture of styrene or a styrene derivative with another monomer to improve the developing characteristics and durability of the toner. It is preferable from the point.

The low softening point substance (component B) used in the present invention has a weight average molecular weight (Mw) of 300 to 10 by GPC.
000 is preferable, and the melting point is preferably 30 to 130 ° C (more preferably 60 to 100 ° C). When the melting point is lower than 30 ° C., low temperature offset or the like tends to be promoted during fixing. Further, if the temperature is higher than 130 ° C., the component B is added during toner production.
Is easily solidified and the granulation property is likely to deteriorate.

When wax is used as the low softening point substance,
The effect of the present invention is further exerted. Examples of the waxes used in the present invention include paraffin, polyolefin-based waxes, and modified products thereof (for example, oxides and graft-treated products), higher fatty acids and metal salts thereof, and amide waxes.

The low softening point substance is 5 to 5 based on the toner.
It is preferably contained in an amount of 30% by weight.

The ratio of the components A and B is A: B
= 50: 50 to 95: 5, more preferably A: B = 70: 30 to 90:10. 5
When the amount of component B is more than 0:50, it becomes difficult to maintain the capsule structure, and when the amount of component B is less than 95: 5, the action and effect of component B are difficult to be exhibited.

The main part of the phase B mainly composed of the low softening point substance is present in the central part of the toner particle, and the area of the phase B in the cross section of the toner particle is 10 to 45%.
It is preferable in terms of fixability and offset resistance.

In the toner of the present invention, it is preferable that no phase mainly composed of the component B exists in the vicinity of the surface from the surface of the toner particles to a depth of 0.15 times the particle diameter of the toner. That is, conceptually, the surface layer has a toner particle size of 0.1.
It means that the thickness is 5 times or more. For example, even if there is a surface layer portion having a crack and not having a thickness of 0.15 times, it is included in the scope of the present invention as long as the phase mainly containing the component B does not exist in the crack. If a phase mainly composed of the component B is present in the vicinity of the surface from the toner surface to a depth of 0.15 times the toner particle size, the capsule structure becomes unstable and, for example, the blocking property tends to deteriorate.

The concave portion on the surface, which is one of the features of the present invention,
This can be preferably achieved by dissolving a specific polar resin soluble in a monomer that produces component A mainly constituting the surface layer in a predetermined amount in the monomer, followed by a granulation step and a suspension polymerization step. it can.

Examples of the polar resin include, for example, cationic polymers such as polymers of nitrogen-containing polymerizable monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, or styrene and unsaturated carboxylic acid esters. Copolymers with nitrogen-polymerizable monomers; examples of anionic polymers include nitrile monomers such as acrylonitrile, halogen monomers such as vinyl chloride, acrylic acid,
Examples include unsaturated carboxylic acids such as methacrylic acid, unsaturated dibasic acids, unsaturated dibasic acid anhydrides, polymers of nitro monomers or copolymers with styrene or styrene monomers. It is not limited to those listed here.

Among these polar resins, in particular, the ratio (Mw / M) of the weight average molecular weight and the number average molecular weight in GPC.
n) is preferably 10 or less, more preferably 5 or less. When such a polar resin is added to a monomer and granulated and suspension polymerized, phase separation between a phase mainly containing component A (phase A) and a phase mainly containing component B (phase B) is promoted. . That is, the interface between the A phase and the B phase becomes clear, and the concentration of the component B contained in the A phase is significantly reduced. As a result, the capsule structure of the toner particles themselves becomes more remarkable, and it is possible to achieve both an improvement in blocking resistance and an improvement in fixing property.

Further, the above tendency becomes more remarkable as the acid value of the polar resin is higher, and when the acid value is 20 or more, preferably 30 or more, the phase separation is promoted. In addition, the polar resin having a high acid value is likely to be unevenly distributed in the vicinity of the toner surface even in the A phase, and as a result, the shape of the surface of the toner is greatly affected, and a toner having a depressed portion on the surface can be produced. Although the details are unknown, the polar resin with a high acid value gathers near the toner particle surface in the granulation step and the initial stage of the suspension polymerization reaction, and as the polymerization reaction of the monomer proceeds, as a kind of aggregate in which the polar resin gathers. It comes to exist near the surface. When the volume contraction of the suspended particles due to the polymerization of the monomer begins to occur, the degree of the contraction varies depending on the uneven distribution of the polar resin, and eventually the atypical toner having a shape in which the surface is partially depressed is generated. Guessed. With an acid value of less than 20, such effects are unlikely to be exhibited.

On the contrary, since the polar resin having too high an acid value disturbs the surface condition of the toner and deteriorates the granulation property, the acid value of the polar resin is 20 to 100, more preferably 30 to 80. Is preferred. Further, if Mw / Mn is 10 or more even when the acid value is 30 to 80, uniform dispersion in the monomer is difficult, and a toner having a target particle size distribution tends to be hardly obtained. A polar resin having an extremely large Mw that does not uniformly dissolve in the monomer is not preferable.

Further, even if the polymerization is carried out using a polar monomer having a polar group instead of the polar resin, unevenness does not occur, and if a large amount of the polar monomer is used for polymerization, the granulation property tends to be remarkably reduced. It is in.

It is preferable to use a polar resin having a weight average molecular weight of 10,000 to 200,000.

The amount of the polar resin used is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the polymerizable monomer.
If the amount of the polar resin used is too small, the degree of toner irregularity decreases, which is not preferable. On the other hand, if the amount of the polar resin used is too large, it becomes difficult to granulate the polymerizable monomer composition in the aqueous dispersion medium, and it becomes difficult to obtain a toner having a sharp particle size distribution.

In general, in the suspension polymerization method, a polymerizable monomer composition substantially incompatible with a dispersion medium such as water is dispersed and polymerized to form toner particles. In order to obtain toner particles having a sharp particle size distribution, the droplets of the polymerizable monomer composition (monomer composition particles) suspended in the liquid dispersion medium are made to have a constant diameter during the polymerization process. How to keep it stable is a very important issue.

In order to solve this problem, dispersion stability which gives a suitable interfacial tension to the interface between the droplets of the monomer composition and the dispersion medium without adversely affecting the environmental characteristics of the toner (for example, moisture resistance). Finding agents is extremely important. Regarding the dispersion stabilizer, the present applicant has previously used a method using a dispersion stabilizer that sharpens the toner particle size distribution and has little influence on the development characteristics, using a poorly water-soluble inorganic dispersant, and (Japanese Patent Application Laid-Open No. 63-1980075) has been proposed.

The dispersion medium used in the present invention includes:
Any suitable dispersion stabilizer can be used. For example, as a dispersion stabilizer of a poorly water-soluble inorganic compound, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, sulfuric acid. There are calcium, barium sulfate, etc.

Such a poorly water-soluble inorganic compound preferably has a primary particle size of 3 μm or less, more preferably 2 μm or less.

As these inorganic compounds, powdery inorganic compounds may be used as they are, but a method of producing a poorly water-soluble inorganic compound in water using a substance such as sodium phosphate and calcium chloride and using it as is is It is preferable because an inorganic compound in a fine particle state and having good dispersibility can be easily obtained.

Generally, the powdery poorly water-soluble inorganic compound generally has a strong agglomeration state, and the particle size of this agglomerate is also nonuniform. Therefore, when such a powder is used, Dispersion often needs to be done carefully. However, if the method of producing a poorly water-soluble inorganic compound in water as described above is used, a good dispersed state of the inorganic compound can be easily obtained.

Further, when the poorly water-soluble compound is formed in water, the water-soluble neutral salts obtained together with the poorly water-soluble compound have the effect of preventing the polymerizable monomer from dissolving in water and the aqueous medium. It also has the effect of increasing the specific gravity of.

The following is an example of a reaction for producing a poorly water-soluble inorganic compound. It is not limited to this. (1) 2Na ₃ PO ₄ + 3CaCl ₂ → Ca ₃ (PO ₄ ) ₂ + 6NaCl (2) 2Na ₃ PO ₄ + Al ₂ (SO ₄ ) ₃ → 2AlPO ₄ + 3Na ₂ SO ₄ (3) 2Na ₃ PO ₄ + 3ZnSO ₄ → Zn ₃ (PO ₄ ) ₂ + 3Na ₂ SO ₄ (4) Na ₂ CO ₃ + ZnCl ₂ → ZnCO ₃ + 2NaCl (5) Na ₂ CO ₃ + ZnSO ₄ → ZnCO ₃ + Na ₂ SO ₄

Furthermore, in the above method, two or more kinds of poorly water-soluble inorganic compounds may be used in combination, if necessary. These hardly water-soluble inorganic dispersants are preferably used in an amount of 1 to 20% by weight (more preferably 1 to 10% by weight) based on the polymerizable monomer composition.

When calcium phosphate is used as the dispersion stabilizer, those having satisfactory particle size distribution, toner shape, and toner internal structure can be obtained, and the effects of the present invention can be further exerted.

Although powdery calcium phosphate may be used as it is, it is preferable to use calcium phosphate in water using a substance such as sodium phosphate and calcium chloride as described above, and use the method.

By using this method, a very fine salt is obtained, and a stable suspension state is obtained, so that the granulating property is good. Also, regarding the toner shape, the size and number of the concave portions on the surface are preferable. Further, since the particles of the polymerizable monomer composition are stable, the phase separation between the component A and the component B is promoted, and greatly contributes to the formation of the internal structure and the promotion of the two-phase structure of the toner as in the present invention. To do.

In the present invention, after confirming that the formed monomer composition particles have a predetermined particle size, the liquid temperature of the aqueous dispersion medium containing the particles (for example, 55 to 70 ° C.)
And a method of advancing the polymerization reaction, or a method of adjusting the liquid temperature of the aqueous dispersion medium and advancing the polymerization simultaneously with granulation / dispersion, and the like are used.

After the completion of the polymerization reaction of the monomer composition, a post-treatment is carried out by a usual method (for example, using HCl),
A toner (polymerized toner) produced by the suspension polymerization method is obtained. For example, Bronsted acid is added to the system containing the produced polymer particles to remove the poorly water-soluble inorganic dispersant powder, and then the polymer particles are recovered by an appropriate method such as filtration, decantation or centrifugation. The toner can be obtained by drying.

The sparingly water-soluble inorganic dispersant soluble in the Bronsted acid used in the present invention can be relatively easily removed from the toner particle surface by the above-mentioned acid (or alkali) treatment.

The fact is that the correlation between the hydrophilicity of the toner particle surface due to the residual dispersion stabilizer and the charging property of the toner has not been studied so far.

In the present invention, as a result of earnest studies on this point, the above-mentioned poorly water-soluble inorganic dispersant can be removed by dropping Bronsted acid into the dispersion medium and lowering the pH of the solution. The amount of the acid to be dropped is insufficient, or the removal is not sufficient in a short post-treatment step. As a result, the chargeability is reduced, and the chargeability particularly under high temperature and high humidity tends to be unstable.

Especially when a polar resin is used,
The effect of residual dispersion stabilizer is significant. Although details are unknown, when the amount of the remaining inorganic dispersant was changed by changing various pHs, the amount of the inorganic dispersant exceeding 0.2% by weight based on the polymerizable monomer composition was present. The triboelectrification property of the toner decreases during charging, and the charging stability especially under high temperature and high humidity decreases. In addition, when various additives are externally added to control fluidity and chargeability, the runout tends to increase. Further, this tendency is more remarkable in a system in which a large amount of an inorganic dispersant is added in an attempt to reduce the toner particle size. This is considered to be due to the water absorption of the residual inorganic dispersant.

On the other hand, if no inorganic dispersant is present on the surface of the toner particles, the amount of triboelectric charge of the toner becomes excessive during development in a low-humidity environment, and charge-up tends to occur.

In the present invention, the pH in the dispersion medium is set to 3
An acid such as HCl is dropped so that the amount becomes less than or equal to (preferably 2.5 or less), and the amount of the remaining inorganic dispersion stabilizer is 0.005 wt% to 0.2 wt% (more preferably, based on the toner). 0.01 to 0.2% by weight) is preferable.

The toner used in the present invention is obtained, for example, by the following method. Release agent in the polymerizable monomer,
A colorant, a charge control agent, a polymerization initiator, and other additives are added, and a homogenizer, an ultrasonic disperser or the like is used to uniformly dissolve or disperse the prepared polymerizable monomer composition.
It is dispersed in an aqueous medium containing a dispersion stabilizer by a usual stirrer or a high shear mixer such as a homomixer or a homogenizer. Preferably, the stirring speed and time are adjusted so that the droplets of the monomer composition have a desired toner particle size, generally 30 μm or less (for example, 1 to 20 μm, preferably 4 to 10 μm). Grain. After that, the action of the dispersion stabilizer is sufficient to maintain the particle state and perform stirring to such an extent that the particles are prevented from settling and floating. After completion of the reaction, the dispersion stabilizer is removed, the produced toner particles are washed, collected by filtration and dried. In the suspension polymerization method, 300 parts of water is usually added to 100 parts by weight of the monomer composition.
It is preferred to use ˜3000 parts by weight as the dispersing medium.

In the above suspension polymerization method, the polymerization temperature is 40.
Polymerization is carried out at a temperature of not lower than 0 ° C, preferably 50 to 90 ° C.

At this time, as a method of controlling the polymerization temperature, the polymerization temperature is further increased by 5 to 50% during the progress of the polymerization.
A method of raising the temperature by 30 ° C. is preferable. The present inventors can increase the degree of depressions on the toner surface by raising the temperature during the polymerization. Further, it is considered that increasing the temperature also promotes phase separation between the A phase and the B phase.

As the polymerization initiator, for example, 2,2'-
Azobis- (2,4-dimethylvaleronitrile), 2,
2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2 '
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4- Peroxide-based polymerization initiators such as dichlorobenzoyl peroxide and lauroyl peroxide are exemplified. These polymerization initiators are preferably used in an amount of 0.5 to 20% by weight based on the polymerizable monomer.

In the present invention, a crosslinking agent may be added to the monomer composition. The preferable addition amount is 0.001 to 15% by weight based on the polymerizable monomer.

In the present invention, it is preferable to add a charge control agent to the toner for the purpose of controlling the chargeability of the toner. As these charge control agents, among the known ones, those having almost no polymerization inhibitory property / water phase transfer property are used. Examples of positive charge control agents include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, amine and polyamine compounds, and negative charge control agents include metal-containing salicylic acid compounds and metal-containing monoazo dye compounds. , Styrene-acrylic acid copolymer, styrene-
Examples thereof include methacrylic acid copolymers.

As the colorant used in the present invention, known colorants can be used, and examples thereof include carbon black and C.I.
I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modant Red 30, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I.
I. Acid Blue 9, C.I. I. Acid Blue 15,
C. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modant Blue 7, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I.
I. Dyes such as Basic Green 6, Yellow Lead, Cadmium Yellow, Mineral Fast Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Tartrazine Lake, Molybdenum Orange, Permanent Orange GTR, Benzidine Orange G, Cadmium Red, Permanent red 4
R, Watching Red Calcium Salt, Brilliant Carmine 3B, Fast Violet B, Methyl Violet Lake, Navy Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, Malachite Green. There are pigments such as lake and final yellow green G.

In the present invention, since the toner is obtained by the suspension polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant. Preferably, the surface modification of the colorant, for example, a hydrophobic treatment with a substance that does not inhibit polymerization is performed. In particular, attention must be paid to the use of dyes and carbon blacks because many of them have polymerization inhibitory properties. As a preferred method of surface-treating the dye, a method of polymerizing a polymerizable monomer in the presence of these dyes in advance is mentioned, and it is preferable to add the obtained colored polymer to the monomer composition. Further, the carbon black may be subjected to the same treatment as that of the above dye, or to a graft treatment with a substance that reacts with the surface functional group of the carbon black, such as polyorganosiloxane.

In the present invention, a magnetic substance may be added to the toner particles, but it is preferable to use a magnetic substance after surface treatment.

The additives used for the purpose of imparting various characteristics in the present invention are, from the viewpoint of durability when added to the toner,
The particle diameter is preferably 1/10 or less of the weight average diameter of the toner particles. The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As the additives for the purpose of imparting these characteristics, for example, the followings are used, but are not particularly limited.

1) As the fluidity-imparting agent: metal oxide (silica, hydrophobic silica, silicon oxide, aluminum oxide, titanium oxide, etc.), carbon black, carbon fluoride, etc. Those subjected to a hydrophobic treatment are more preferable. 2) As abrasives: metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, Barium sulfate, calcium carbonate, etc.) are preferred. 3) As the lubricant, it is preferable to use: a fluorine-based resin powder (vinylidene fluoride, polytetrafluoroethylene, etc.), a fatty acid metal salt (zinc stearate, calcium stearate, etc.) and the like. 4) As the charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.), carbon black and the like are preferable.

These additives may be used in an amount of 0.1 to 10 parts by weight (preferably 0.1 to 5 parts by weight) based on 100 parts by weight of the toner. These additives may be used alone or in combination.

FIG. 1 shows an example of the surface shape of a toner particle having a plurality of concave portions on the surface of the toner of the present invention. Such multiple recesses improve carrier and sleeve contamination. Furthermore, the presence of the concave portions on the surface of the toner particles also improves the cleaning property. Further, since the toner is almost spherical, a high quality toner image can be obtained. Further, since fine pulverization due to stirring of the developing device is unlikely to occur, fogging and scattering of fine powder do not occur.

The image forming method according to the present invention can be carried out using, for example, a developing device shown in FIG. In the developing device shown in FIG. 5, a bias electric field composed of an AC component and a DC component is applied between the developer carrier (sleeve) and the latent image carrier (photoconductor). This causes the magnetic particles to violently fly. The vibration and flight of the toner and magnetic particles produce the following effects.

In other words, the developing efficiency becomes extremely high because the toner flies from the surface of the magnetic brush and the developer carrying member for development. Therefore, the coating amount of the developer is relatively small and the resolution of the developed image is enhanced. Further, since the developing efficiency is high, it is possible to make the relative speeds of the developer carrying member and the photosensitive member substantially the same, and it is difficult for the solid developing portion to be swept up due to the relative speed. Further, even if the relative speed is increased, there is an effect of reducing sweeping.

Further, since the magnetic particles are vibrated by the alternating electric field, traces of individual magnetic brushes are not generated, and an extremely high quality developed image can be obtained. Furthermore, by applying an alternating electric field that causes the magnetic particles to move in the space defined by the developing carrier and the photoconductor, the magnetic particles behave in the image area together with the toner to promote development when the magnetic particles fly as described above. In the background, however, the toner behaves in the opposite manner, and has the effect of separating the toner adhering to the photoreceptor surface, thus preventing fog. Further, the magnetic particles attached to the surface of the photoconductor are finally pulled back toward the developer carrier by the magnetic force and the moving force of this electric field, and the amount of the magnetic particles attached to the photoconductor can be reduced. In addition, even when the ears of the magnetic particles are unevenly distributed, the ears partly collapse when the magnetic particles fly, and the magnetic particles are smoothed.

The volume ratio of magnetic particles in the developing section will be described with reference to FIGS. 6 and 7. "Development part"
Is a portion where the toner 5 is transferred or supplied from the developer carrying member (sleeve) 3 to the photosensitive drum (latent image holding member) 4. The “volume ratio” is a percentage of the volume of the magnetic particles 6 present therein relative to the volume of the developing section.
As a result of various experiments and considerations, it was found that this volume ratio has an important effect in the developing device,
It has been found that it is extremely preferable to set the content to 45%, particularly 15 to 28%. If it is less than 10%, a reduction in developed image density is observed, sleeve ghost occurs,
It is not preferable because a remarkable density difference is generated between the portion where the ears are present and the portion where the ears are not present, and the thickness of the developer layer formed on the surface of the sleeve is not uniform as a whole. On the other hand, if it exceeds 45%, the degree to which the sleeve surface is closed increases, and fogging occurs, which is not preferable.

In particular, in the present invention, the image quality does not monotonically deteriorate or increase as the volume ratio increases or decreases, but a sufficient image density is obtained in the range of 10 to 45%, and 45% even if less than 10%. This is based on the fact that, even if the value exceeds the limit, the image quality is deteriorated, and neither sleeve ghost nor fog occurs in the range of the above numerical value where the image quality is sufficient. The former image quality deterioration is considered to be due to the negative characteristic, and the latter is considered to result from the fact that the amount of magnetic particles present becomes large and the sleeve surface cannot be opened, and the toner supply amount from the sleeve surface is greatly reduced.

On the other hand, if it is less than 10%, the reproducibility of the line image is inferior and the image density is significantly lowered. On the other hand, when it exceeds 45%, there are problems that the magnetic particles damage the surface of the photosensitive drum, and there is a problem of transfer and fixing that occurs because they adhere as a part of the image.

When the presence of magnetic particles is close to 10%, a large area uniform high-density image (solid black) is reproduced.
Since there is a case where partial development unevenness occurs (under a special environment, etc.), it is preferable that the volume ratio is such that these are less likely to occur.

This value is more preferable because the volume ratio of the magnetic particles to the developing area is 15% or more. If the presence of magnetic particles is close to 45%, the toner supply from the sleeve surface may be delayed around the part where the magnetic particles are in contact with each other (when the developing speed is high, etc.), and scales may be observed during solid black reproduction. Uneven density may occur. As a certain range for preventing this, the above volume ratio of the magnetic particles is more preferably 28% or less.

If the volume ratio is in the range of 10 to 45%,
In FIG. 6, the ears 9 are formed on the surface of the sleeve 3 in a sparse manner to a preferable degree, the toners on both the sleeve 3 and the ears 9 are sufficiently opened to the photosensitive drum 4, and the toners on the sleeves also alternate. Since the toner is fly-transferred by the electric field, almost all of the toner is ready for consumption for development, and therefore high development efficiency (ratio of toner that can be consumed for development in the toner existing in the development section) and high image density can be obtained. .

The volume ratio (%) of the magnetic particles existing in the developing section is (M / h) × (1 / ρ) × [(C / (T + C)] × σ ×
100. Here, M is a coating amount (g / g) of the developer (mixture...
cm ² ), h is the height of the developing space (cm), ρ is the true density of magnetic particles g / cm ³ , C / (T + C) is the weight ratio of the magnetic particles in the developer on the sleeve, and σ is the photosensitivity. The peripheral speed ratio of the drum and the sleeve (sleeve peripheral speed / photosensitive drum peripheral speed). In the developing section defined above, the ratio of the toner to the magnetic particles is preferably 3 to 40% by weight.

The magnetic particles used in the present invention preferably have a narrow particle size distribution and are sharply cut. A phenomenon in which magnetic particles 6 adhere to the photosensitive drum 4 and adversely affect an image or a copying machine, so-called carrier adhesion, is likely to occur in the presence of ultrafine magnetic particles, but the magnetic particles used in the present invention are 400 mesh. Since the following fine powder amount is sharply cut to 20% by weight or less, carrier adhesion is preferably prevented. More preferably 15% by weight
The following is good.

In the present invention, the amount of coarse powder of 250 mesh or more is 20% by weight or less (more preferably 10% by weight).
The following) It is preferable to use magnetic particles having a uniform particle size. As a result, the fluidity of the developer is increased, and the toner and the magnetic particles are quickly mixed when the toner is supplied. As a result, the charge distribution of the toner becomes sharp, a high-quality image without fog is obtained, and there is no toner scattering. Further, since the developing rate and the transfer rate of the toner are improved, the waste toner rate is reduced and the toner is efficiently consumed. However, magnetic particles of uniform particle size have a better packing and promote the carrier spent.

In the case of a two-component developer, it is possible to preferably prepare a developer in which carrier spent is less likely to occur by combining with a toner particle having a thick surface layer capsule structure and having a plurality of recesses.

Next, an example of another developing device used in the present invention will be described. In FIG. 8, reference numeral 21 is a latent image holder (photosensitive drum), and latent image formation is performed by electrophotographic process means or electrostatic recording means (not shown). Reference numeral 2 denotes a development carrier (developer sleeve), which is composed of a non-magnetic sleeve of aluminum or stainless steel. Such a developer carrier 22 may be a crude tube of aluminum or stainless steel as it is, but is preferably made of a material whose surface is uniformly roughened by spraying glass beads or the like, a material whose surface is mirror-finished, or a resin. Coated is good. The developer is stored in a hopper 23 and is supplied onto the developer carrier 2 by a supply roller 24. Supply roller 2
4 is made of foam material such as polyurethane foam,
The developer carrier 22 is rotated in a forward or reverse direction at a relative speed which is not 0, and the developer is supplied and the developer (undeveloped developer) on the developer carrier 22 after development is peeled off. ing.

The developer supplied onto the developer carrier 22 is uniformly and thinly coated by the developer coating blade 25. Developer coating blade 25 and developer carrier 22
The contact pressure with is 3 to 2 as the linear pressure in the sleeve generatrix direction.
50 / cm, preferably 10-120 g / cm is effective. If the contact pressure is less than 3 g / cm, it becomes difficult to apply the toner uniformly, and the charge amount distribution of the toner becomes broad, causing fog and scattering. Also, the contact pressure is 2
If it exceeds 50 g / cm, a large pressure is applied to the developer, and the external additive of the developer is deteriorated, so that the developer is agglomerated, which is not preferable. In addition, a large torque is required to drive the developer carrier 22, which is not preferable.

The developer coating blade 25 is preferably made of a triboelectric material suitable for charging the developer to a desired polarity. For example, in order to positively charge the developer, silicone rubber, polyurethane, fluororubber, polychlorobutadiene rubber, etc., and to charge it negatively, use styrene-butadiene rubber, nylon, etc. as a blade. The charging efficiency is higher.
Further, by blending silica, resin fine particles, and the like, it is also possible to adjust the triboelectric charging property of the blade to the developer. Further, by blending a conductive powder such as carbon or titanium oxide to give the blade proper conductivity, it is possible to prevent the developer from being excessively charged.

As a method for fixing a toner by heating according to the present invention, for example, a fixing device shown in FIG. 9 or FIG. 10 is used. In the fixing device shown in FIG. 9 or FIG. 10, the heating body has a smaller heat capacity than a conventional heat roll and has a linear heating unit, and the maximum temperature of the heating unit is 100.
It is preferably ˜300 ° C. Furthermore, the film located between the heating element and the pressing member has a thickness of 1 to 100 μm.
It is preferable to use heat-resistant sheets such as polyester, PET and the like.
(Polyethylene terephthalate), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene),
In addition to polymer sheets such as polyimide and polyamide, a metal sheet such as aluminum and a laminated sheet composed of a metal sheet and a polymer sheet are used.

The structure of the film according to the present invention is that these heat-resistant sheets have a release layer and / or a low-resistance layer. The surface characteristics of the surface of the film that is pressed against the recording material preferably have a critical surface tension of 30 dyne / cm or less and a surface electric resistance of 10 ¹⁰ Ω / cm ² or less.

As the film applied to the present invention, a heat-resistant material such as polyimide, polyetherimide, PES, PFA or the like is used as a heating body pressure contact surface, and a critical surface tension of 30 dyne such as PTFE or PAF is provided on at least the image contact surface side. / C
A multi-layer coat film having a low resistance release layer having a surface electric resistance of 10 ¹⁰ Ω / cm ² or less in which a conductive material is added and dispersed in a binder resin of m or less is more preferably used. . Examples of the conductive material preferably used in the present invention for controlling surface electric resistance include carbon black, graphite, and inorganic oxides.

The critical surface tension of the surface of the film used in the heat fixing method of the present invention, which is brought into pressure contact with the recording material, is 30 dyne / c.
If it exceeds m, a so-called offset phenomenon that toner adheres to the film surface becomes remarkable. Further, when the surface electric resistance exceeds 10 ¹⁰ Ω / cm, the electrostatic offset phenomenon in which the toner electrostatically adheres to the film surface becomes remarkable. The method for measuring the surface electric resistance in the present invention is described in J
According to IS standard K6911.

The critical surface of the surface of the present invention that comes into pressure contact with the recording material is measured by measuring the contact angle θ of various organic liquids (hydrocarbon series or the like) having different surface tensions γ on the film surface, and
It was determined by performing an isman plot.

Hereinafter, a preferred heat fixing device of the present invention will be described with reference to the accompanying drawings. This does not limit the invention in any way. FIG. 9 shows a structural diagram of the fixing device of this embodiment.

Reference numeral 36 denotes a low heat capacity linear heating element which is fixedly supported by the apparatus, and has a thickness of 1.0 mm and a width of 10 m as an example.
m, a length of 240 mm, and an alumina substrate 37 with a resistance material 3
8 is applied to have a width of 1.0 mm, and electricity is applied to both ends in the longitudinal direction. The energization is a pulsed waveform with a cycle of 20 msec of DC 100 V and is given by varying the pulse width according to a desired temperature and energy release amount controlled by the temperature measuring element 39. Approximate pulse width is 0.5 mse
c to 5 msec. The fixing film 30 moves in the direction of the arrow in the figure by coming into contact with the heating body 36 whose energy and temperature are controlled in this way. The fixing film is, for example, a heat-resistant film having a thickness of 20 μm, for example, an endless film in which a release layer in which carbon black as a conductive material is added to polyimide and imide on the heating body contacting side and PTFE on the image contacting side is coated to 10 μm is coated. is there. The critical surface tension of the surface of the film pressed against the recording material is 20 dyne / cm.
And the surface electric resistance was 1 × 10 ⁶ Ω / cm ² .
Generally, the total thickness is more than 100 μm, preferably less than 40 μm.

The film drive moves in the direction of the arrow without wrinkles due to the drive and tension of the drive roller 31 and the driven roller 32. Reference numeral 33 is a pressure roller having a rubber elastic layer having a good releasability such as silicone rubber and having a total pressure of 4 to 2
The heating element is pressed through the film at 0 Kg, and is rotated in pressure contact with the film. The unfixed toner 35 on the transfer material 34 is guided to the fixing portion by the entrance guide 36, and a fixed image is obtained by the above heating.

The endless belt has been described above. However, as shown in FIG. 10, a sheet feed shaft 47 and a take-up shaft 48 may be used, and the fixing film 40 may be an edged film. Further, the image forming apparatus is applicable to a fixing device for an apparatus that forms an image using toner such as a copying machine, a printer, a facsimile, and the like.

[0135] In the low heat capacity linear heating member 36, when the temperature detected by the temperature detection element 39 is T _1, the surface temperature T ₂ is about 10 than T ₁ of the film 30 opposed to the resistance material 38
~ 30 ° C lower. Further, the film surface temperature T _{3 at} the portion where the film 30 is peeled off from the toner fixing surface is substantially equal to the temperature T ₂ .

Next, the particle size distribution measurement in the present invention will be described.

As a measuring device, a Coulter counter T
A-II type (manufactured by Coulter, Inc.)
Interface to output volume average distribution (made by Nikkaki)
And CX-1 personal computer (made by Canon) are connected, and the electrolyte is 1% NaC using primary sodium chloride.
Prepare an aqueous solution.

As a measuring method, the electrolytic aqueous solution 100 to 1 is used.
In 50 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 0.5 to 50 mg of a measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and was subjected to a dispersion treatment using the Coulter Counter TA-II using a 100 μm aperture as an aperture.
The volume average distribution and the number average distribution are determined by measuring the particle size distribution of the μm particles.

The weight average particle diameter (D4) is obtained from the thus obtained volume average distribution and number average distribution.

Next, the melting point of the low softening point substance such as wax in the present invention is measured at a temperature rising rate of 10 ° C./min using DSC-7 (manufactured by Perkin Elmer), and the temperature at the time of the first heating is measured. In the DSC curve, the temperature at the apex of the peak showing the maximum endotherm is the melting point of the wax.

The toner melting behavior in the present invention is measured by an elevated flow tester (Shimadzu flow tester CFT).
-500 type) is used. A sample of 1.0 g in weight molded using a pressure molding machine is pushed out from a nozzle of 1 mm in diameter and 1 mm in length by applying a load of 20 kgf with a plunger at a heating rate of 5.0 ° C./min. The plunger drop of the tester was measured. At this time,
The temperature at the sample outflow start point of the plunger drop-temperature curve of the flow tester is defined as the flow start temperature.

The molecular weight measuring method in the present invention is shown below.

(1) Sample Preparation i) Standard Sample As a standard sample, the following commercially available standard polystyrene is used.

[0144]

[Outside 1]

These twelve standard polystyrenes are divided into 3 groups as follows. 8.42 × 10 ⁶ , 7.75 × 10 ⁵ , 3.5 × 1
0 ⁴ , 3.6 × 10 ^3, 2.7 × 10 ⁶ , 4.7 × 10 ⁵ , 1.5 × 10 ⁴ ,
2.35 × 10 ³ 1.2 × 10 ⁶ , 2.0 × 10 ⁵ , 1.02 × 10 ⁴ ,
5.0 × 10 ²

About 3 mg of each of the 4 samples in the group (1 cup per microspatel) was placed in a 30 ml sample bottle, and 1
Add 5 ml of THF and leave at room temperature for 4 hrs (during this, shake vigorously every 30 minutes for 1 minute). Then, it is filtered using a membrane filter (regenerated cellulose, 0.45 μm: manufactured by Toyo Roshi Kaisha, Ltd.) to obtain a standard sample.

Ii) Unknown sample Weigh 60 mg of the sample into a sample bottle, and further add THF1
Add 5 ml. The extraction conditions are left at room temperature for 24 hours while shaking every 30 minutes for the initial 3 hours. In addition, 15
Apply ultrasonic waves for a minute to sufficiently extract. After insoluble matter was sedimented by centrifugation (5000 rpm / 20 min),
The supernatant is filtered using a membrane filter (regenerated cellulose, 0.45 μm: manufactured by Toyo Roshi Kaisha, Ltd.),
Make a sample.

(2) Waters, 150C ALC / GPC as a GPC device
Was measured under the following conditions.

I) Solvent THF (special grade manufactured by Kishida Chemical Co., Ltd.) ii) Column Shoredex A-802, A-80
3, A-804, A-805 four connections (manufactured by Showa Denko) iii) Temperature 28 ° C iv) Flow rate 1.0 ml / min v) Injection amount 0.5 ml vi) Detector RI (3) GPC data processing method i ) Calibration curve Take the chromatogram of the standard sample and read the retention time at the peak. When the peaks are divided, it is the time of the main peak.

A calibration curve is drawn from the molecular weight of the standard sample and the retention time of the peak.

Ii) Unknown sample A molecular weight is calculated from a retention time of a chromatogram of an unknown sample using a calibration curve.

Next, the method for measuring the particle size distribution of magnetic particles will be described. 1. Weigh about 100 g of sample to the nearest 0.1 g. 2. As the sieve, a standard sieve of 100 mesh to 400 mesh (hereinafter referred to as a sieve) is used.
The pans are stacked in the order of 0, 250, 350, and 400, and a saucer is placed on the bottom, and the sample is put on the top sieve and covered. 3. This is 285 ± 6 per minute with horizontal vibration
15 times for 15 minutes at 150 ± 10 times per minute. 4. After sieving, weigh the iron powder in each sieve and tray to the nearest 0.1 g. 5. Calculated to the second decimal place as a percentage by weight, JIS-Z8
Round up to the first decimal place by 401.

However, the size of the frame of the sieve should be such that the inner diameter above the sieve surface is 200 mm and the depth from the upper surface to the sieve surface is 45 mm.

The total weight of the iron powder in each part must not be less than 99% of the mass of the sample taken at the beginning. The average particle size is determined from the above measured particle size distribution according to the following equation. Average particle size (μm) = 1/100 × {(remaining amount of 100 mesh sieve) × 140 + (remaining amount of 145 mesh sieve) × 12
2+ (remaining amount of 200 mesh sieve) × 90 + (remaining amount of 250 mesh sieve) × 68 + (remaining amount of 350 mesh sieve) ×
52+ (remaining amount of 400 mesh sieve) × 38 + (total sieve passing amount) × 17}

[0155]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 To 709 parts by weight of ion-exchanged water was added 451 parts by weight of 0.1 M Na ₃ PO ₄ aqueous solution, and the mixture was heated to 60 ° C., and then using a TK homomixer (made by Tokushu Kika Kogyo). 12000 rp
m. A 1.0 M CaCl ₂ aqueous solution 6
7.7 parts by weight was gradually added to obtain a dispersion medium containing Ca ₃ (PO ₄ ) ₂ . -Styrene 170 parts by weight-2 Ethylhexyl acrylate 30 parts by weight-Paraffin wax (mp 75 ° C) 60 parts by weight-C. I. Pigment Blue 15: 3 10 parts by weight ・ Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 51,000, Mw / Nw = 3.0, acid value 70)
10 parts by weight ・ Di-tert-butylsalicylate metal compound 3 parts by weight

Of the above materials, C.I. I. Pigment Blue 15: 3, di-tert-butylsalicylic acid metal compound and styrene only Ebara Milder (Ebara Corporation)
Was used for premixing. Then add all 6 of the above materials
The mixture was heated to 0 ° C., dissolved and dispersed to prepare a monomer mixture. Further, while maintaining the temperature at 60 ° C., 10 parts by weight of a polymerizable initiator dimethyl 2,2′-azobisisobutyrate was added and dissolved to prepare a polymerizable monomer composition.

The above monomer composition was put into a dispersion medium prepared in a flask of a TK homomixer. Using a TK homomixer in a nitrogen atmosphere at 60 ° C, 10,000
It stirred at rpm for 20 minutes, and granulated the monomer composition. Then, the mixture was reacted at 60 ° C. for 3 hours while stirring with a paddle stirring blade, and then polymerized at 80 ° C. for 10 hours.

After completion of the polymerization reaction, the reaction system was cooled, 27 parts by weight of 5N hydrochloric acid was added, and the mixture was stirred with a paddle stirring blade for another 2 hours to dissolve Ca ₃ (PO ₄ ) ₂ and then filtered and washed with water several times. By repeating the operation repeatedly and finally drying, a toner produced by the suspension polymerization method was obtained.

Ca ₃ remaining on the toner surface by fluorescent X-rays
When the amount of (PO ₄ ) ₂ was quantified, it was found that the amount of 0.
It was 1% by weight.

The particle diameter of the obtained toner was measured with a Coulter counter to find that the weight average diameter was 8.2 μm.
Further, it had a sharp particle size distribution. It was confirmed by observation with an electron microscope that the surface of the toner particles had a plurality of recesses as shown in FIG. R / r of toner particles
Was 1.10 and L / 2πr was 1.20. Furthermore, when the cross section of the toner particles was observed by a transmission electron microscope by a dyeing ultra-thin section method, it was divided into a surface layer part mainly composed of styrene-acrylic resin and a central part mainly composed of wax, and 0.1 of the particle size of the particles
It was confirmed that there was no phase mainly composed of wax near the surface up to five times the depth, and it was within the range of 10 to 45% of the cross-sectional area of the particles.

B was added to 100 parts by weight of the obtained toner.
0.7 parts by weight of a hydrophobic silica having a specific surface area of 200 m ² / g by the ET method was externally added. 7 parts by weight of the toner to which hydrophobic silica was externally added and 93 parts by weight of a Cu-Zn-Fe based ferrite carrier surface-coated with a styrene-methyl methacrylate copolymer were mixed to prepare a two-component developer. .

Using this developer, images were printed with a modified color copying machine (CLC-500 Canon) modified so that the fixing roller was not coated with silicone oil. Table 1 shows the results.

Examples 2 to 11 and 29 In the same manner as in Example 1, the formulations were changed as shown in Table 1, and various toners were produced and evaluated. Table 1 shows the results
Shown in

Example 12 A toner was manufactured in the same manner as in Example 1 except that the polymerization reaction temperature was kept constant at 60 ° C. Table 1 shows the results.

Comparative Example 1 A toner was manufactured in the same manner as in Example 1 except that the amount of paraffin wax was changed. When the cross section of the toner particles was observed, the phase mainly composed of wax was 45% of the particle cross-sectional area.
Was over. Table 2 shows the results.

Comparative Examples 3 to 6, 8 and 9 Various toners were produced according to the formulations shown in Table 2 and evaluated. Table 2 shows the results.

Comparative Example 7 A toner was manufactured in the same manner as in Example 1 except that the amount of paraffin wax was changed. When the cross section of the toner particles was observed, the phase mainly composed of wax was less than 10% of the cross sectional area of the toner particles. Table 2 shows the results.

Comparative Example 10 Toner particles were obtained in the same manner as in Example 1 except that the post-treatment using the HC1 aqueous solution was not carried out. The quantitative result of Ca ₃ (PO ₄ ) ₂ by fluorescent X-ray was 2.
It was 5% by weight.

When an image was formed using the above toner, the flowability of the developer was extremely poor under high temperature and high humidity, and the image formation was interrupted halfway. Further, the triboelectrification amount was low even at low temperature and low humidity, and the obtained toner image was fogged with many fogs.

Example 30 10 parts by weight of amino-modified colloidal silica (200 m ² / g) instead of Ca ₃ (PO ₄ ) ₂ was used as a dispersion stabilizer, and this was added to 1200 parts by weight of water to prepare an aqueous dispersion medium. Obtained. Except for using the resulting aqueous dispersion medium,
Suspension polymerization was carried out in the same manner as in Example 1, and after removing colloidal silica with an aqueous NaOH solution, filtration and washing with water were repeated several times and dried to obtain a toner. Table 2 shows the results.

[0172]

[Table 1]

[0173]

[Table 2]

Example 13 To 709 g of ion-exchanged water, 0.1 M Na ₃ PO ₄ aqueous solution 4 was added.
After charging 51 g and heating to 60 ° C., the mixture was stirred at 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). 6M of 1.0M-CaCl ₂ aqueous solution
Was gradually added to obtain a dispersion medium containing Ca ₃ (PO ₄ ) ₂ . -Styrene 170 parts by weight-2 Ethylhexyl acrylate 30 parts by weight-Paraffin wax (mp 75 ° C) 60 parts by weight-C. I. Pigment Blue 15: 3 10 g parts by weight-Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 50,000, Mw / Mn = 2.5, acid value 50) 5
3 parts by weight of di-tert-butylsalicylate metal compound

Of the above materials, C.I. I. Pigment Blue 15: 3, di-tert-butylsalicylic acid metal compound and styrene only Ebara Milder (Ebara Corporation)
Was used for premixing. Next, add 60
The mixture was heated to ℃, dissolved and dispersed to obtain a monomer mixture. Further, while maintaining the temperature at 60 ° C, the initiator dimethyl 2,2'-
10 g of azobisisobutyrate was added and dissolved to prepare a monomer composition.

The above monomer composition was added to the dispersion medium prepared in the 21 flask of the homomixer. Using a TK homomixer in a nitrogen atmosphere at 60 ° C., 1000
It stirred at 0 rpm for 20 minutes, and granulated the monomer composition.
Then, the mixture was reacted at 60 ° C. for 3 hours while stirring with a paddle stirring blade, and then polymerized at 80 ° C. for 10 hours.

After completion of the weight reaction, the reaction product was cooled and cooled to 5
After adding 27 g of N hydrochloric acid and stirring with a paddle stirring blade for another 2 hours to dissolve Ca ₃ (PO ₄ ) ₂ , filtration, washing with water are repeated several times, and finally drying is performed to produce a suspension polymerization method. The obtained toner is obtained.

Here, when the amount of Ca ₃ (PO ₄ ) ₂ remaining on the toner surface was determined by fluorescent X-ray, it was 0.1% by weight based on the toner.

The particle size of the obtained toner was measured with a Coulter counter to find that the toner had a weight average particle size of 8.2 μm and a sharp particle size distribution. In addition, it was confirmed by observation with an electron microscope that the surface of the particles had an irregular shape and a shape of depression. R / r of the toner was 1.07, and L / 2πr was 1.07. Furthermore, when the cross section of the toner particles was observed by a transmission electron microscope by a dyeing ultra-thin section method, it was divided into a surface layer part mainly composed of styrene-acrylic resin and a central part mainly composed of wax, and the surface of the particle It was confirmed that the wax-based phase did not exist near the surface up to a depth of 0.15 times the particle size.

For 100 parts by weight of the obtained toner, B
0.7 parts by weight of a hydrophobic silica having a specific surface area of 200 m ² / g by the ET method was externally added. 7 parts by weight of the toner to which hydrophobic silica was externally added and 93 parts by weight of a Cu-Zn-Fe based ferrite carrier surface-coated with a styrene-methyl methacrylate copolymer were mixed to prepare a two-component developer. .

Using this developer, an image was printed with a commercially available color copying machine (CLC-500 Canon).

The development conditions were a development contrast of 430 V under 20 ° C./10%, a development contrast of 320 V under 23 ° C./65%, and a development contrast of 270 V under 30 ° C./80%.

As a result, no cleaning failure occurred and the image density was 1.4 to 1.6, which was very stable.
A very clear image with no roughness was obtained. Further, in any environment, the toner was excellent in charging stability with the charge amount hardly changing before and after the endurance.

Comparative Example 12 In Example 13, toner particles were obtained without the HC1 treatment. The quantitative results of Ca ₃ (PO ₄ ) ₂ by fluorescent X-ray are
It was 2.5% by weight with respect to the toner.

When the image was formed using the above toner, the fluidity of the agent was extremely poor under high temperature and high humidity, and the image formation was interrupted halfway. Further, the charge amount was low even under low temperature and low humidity, and the resulting image had a lot of fog but was rough.

Comparative Example 13 In Example 13, 13.5 g of 5N HC1 was added, and the mixture was stirred for 24 hours with a paddle stirring blade to obtain Ca ₃ (PO ₄ ).
_A toner was obtained in the same manner except that ₂ was dissolved.
The quantitative result of Ca ₃ (PO ₄ ) ₂ by fluorescent X-ray was 0.33% by weight based on the toner.

When an image was formed using the above toner, no particular problem occurred under low temperature and low humidity.
During the durability test under high temperature and high humidity, scattering started to occur gradually, and the obtained image was foggy with a lot of fog.

Comparative Example 14 The polar resin used in Example 13 was (Mw = 300).
00, Mw / Nw = 3.8, acid value = 0.2), except that a styrene-butyl acrylate copolymer was used.
Similarly, a cyan toner having a weight average diameter of 8.6 μm was obtained. The amount of residual Ca ₃ (PO ₄ ) ₂ is 0.12 with respect to the toner.
% By weight.

The surface of this toner was not spherical and was a true spherical toner. As a result of carrying out durability using this toner, the density was drastically lowered, and the obtained image was rough.

Comparative Example 15 A 8.3 μm cyan toner was obtained in the same manner as in Example 13 except that the polar resin was not used.

In the same manner, when a developer was prepared and an image was formed, the image density decreased with the endurance, and a cleaning failure occurred at about 3000 μm. When the toner at the start of the durability was observed by FE-SEM, it was a spherical toner with no surface irregularities.

Comparative Example 16 In Example 13, except that polyvinyl alcohol was used as a dispersant instead of Ca ₃ (PO ₄ ) ₂ .
Polymerization was carried out in the same manner, cooling and washing with water were repeated several times to remove polyvinyl alcohol.

The toner thus obtained has a weight average diameter of 8.2 μm.
However, the particle size distribution was considerably broad, and a two-layer structure containing wax, which is a feature of the present invention, could not be obtained.

This means that the stability of the toner particle interface is Ca ₃
It was considered that the reason for this was that the particles fell off compared to (PO ₄ ) ₂ and the granulation property was reduced.

The above toner has poor blocking resistance,
The storage stability was poor.

Example 14 The polar resin used in Example 13 was changed to a styrene-methacrylic acid-methyl methacrylate copolymer having Mw of 100,000, Mw / Nn of 3.5 and an acid value of 70. A cyan toner having a weight average particle diameter of 8.0 μm was obtained in the same manner as in Example 13 except that the toner was replaced. R / r of the toner was 1.08 and L / 2πr was 1.08. The amount of Ca ₃ (PO ₄ ) ₂ remaining is 0.06
% By weight.

A developer was prepared in the same manner as in Example 13,
After running 10,000 sheets, there was little variation in image density, a stable image was always obtained, and cleaning failure was not observed at all. Further, the toner after the endurance is replaced with FE-S
When observed by EM, it was confirmed that the toner had a plurality of concave portions on the surface, which was almost the same as before the durability, and that silica adhered to the surface was confirmed.

Example 15 In Example 13, 498 g of ion-exchanged water was charged with 645 g of an aqueous solution of 0.1 M Na ₃ PO _{4 and} the mixture was heated to 80 ° C. and then stirred at 10,000 rpm using a TK homomixer. Add 1.0M CaCl ₂ solution 96.7
g was gradually added to obtain a dispersion medium containing Ca ₃ (PO ₄ ) ₂ .

The polymerization step was terminated in the same manner as in Example 13 except that the same polymerizable monomer composition as in Example 13 was added, and granulation and polymerization were carried out at 80 ° C. Hydrochloric acid 38.5 g was added to remove Ca ₃ (PO ₄ ) ₂ to obtain a toner.

The particle size of the obtained toner was measured by a Coulter counter to find that the weight average particle size was 5.5 μm and the particle size distribution was sharp. The R / r of the toner is 1.
And L / 2πr was 1.09. Further, the amount of Ca ₃ (PO ₄ ) ₂ remaining on the toner surface was measured by fluorescent X-ray, and it was 0.08% by weight based on the toner.

Example 17 A developer was prepared in the same manner as in Example 13 except that the amount of silica was changed to 1.0 part by weight and the carrier was changed to 94 parts by weight.

Image development was carried out in the same manner with the development contrast slightly higher than in Example 13, and fine line reproducibility
An image excellent in highlight gradation was obtained. In particular, the charging was stable even under high temperature and high humidity, and no problem occurred even in the image forming experiment after leaving for a long time.

Example 17 A 0.1 M Na ₃ PO ₄ aqueous solution and a 1 M CaCl ₂ aqueous solution were prepared. 451 0.1M Na ₃ PO ₄ in a 2 liter flask of TK type homomixer (manufactured by Tokushu Kika Kogyo)
g and ion-exchanged water 709 g, 12000 rpm
And stirred. 67.7 g of ₁ MCaCl ₂ aqueous solution was added to 60
Gradually add to the above homomixer with heating to ℃ under stirring and add C
An aqueous dispersion medium containing a ₃ (PO ₄ ) ₂ was obtained. -Styrene 180g-2 Ethylhexyl acrylate 20g-Paraffin wax (mp 75 ° C) 60g-C.I. I. Pigment Blue 15: 3 10 g ・ Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 488,000; Mw / Mn = 3.1, acid value 70)
5 g-di-tert-butylsalicylic acid metal compound 2 g

Of the above materials, C.I. I. Pigment Blue 15: 3, di-tert-butylsalicylic acid metal compound and styrene only Ebara Milder (Ebara Corporation)
Was used for premixing. Next, add all of the above materials to 60
The mixture was heated to ℃, dissolved and dispersed to obtain a monomer mixture. Further, while maintaining the temperature at 60 ° C., 10 g of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) and 1 g of dimethyl 2,2′-azobisisobutyrate were added and dissolved to obtain a polymerizable monomer. A monomer composition was prepared.

The above monomer composition was added to the aqueous dispersion medium prepared in the 2 liter flask of the homomixer. The monomer composition was granulated by stirring at 60 rpm for 20 minutes at 10,000 rpm using a TK homomixer in a nitrogen atmosphere. Then, while stirring with a paddle stirring blade, 6
After reacting at 0 ° C for 3 hours, polymerization was performed at 80 ° C for 10 hours.

After completion of the polymerization reaction, the reaction system was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , and the mixture was filtered, washed with water and dried to obtain a toner.

The particle size of the obtained toner was measured by a Coulter counter to find that the weight average particle size was 8.6 μm and the particle size distribution was sharp. Also, the presence of a plurality of recesses on the surface of the toner particles was confirmed by an electron microscope. The R / r of the toner is 1.07 and the L / L _o is 1.
05.

Furthermore, when the cross section of the particles was observed by a transmission electron microscope by the dyeing ultrathin section method, it was divided into a surface layer part mainly composed of styrene-acrylic resin and a central part mainly composed of wax, and the particles were separated from the surface. It was confirmed that there was no phase composed mainly of wax in the vicinity of the surface up to a depth of 0.15 times the particle size of.

B was added to 100 parts by weight of the obtained toner.
0.7 parts by weight of a hydrophobic silica having a specific surface area of 200 m ² / g by the ET method was externally added.

7 parts by weight of this toner to which hydrophobic silica is externally added, an average particle size of 50 μm, a fine powder amount of 400 mesh or less is 12% by weight, and a coarse powder amount of 250 mesh or more is 3% by weight. %, And 93 parts by weight of an acrylic resin-coated ferrite carrier were mixed to prepare a developer.

Using the developer thus obtained,
As a result of performing a running test on 20,000 sheets using a CLC-500 manufactured by Canon Inc., an image having an image density of 1.4 or more, no fog, and a very high resolution image was stably obtained. When the surface of the carrier particles after the running test was observed with an electron microscope, the carrier spent was at a level without problems.

Example 18 A 0.1 M Na ₃ PO ₄ aqueous solution and a 1 M CaCl ₂ aqueous solution were prepared. 451 0.1M Na ₃ PO ₄ in a 2 liter flask of TK type homomixer (manufactured by Tokushu Kika Kogyo)
g and ion-exchanged water 709 g, 12000 rpm
And stirred. 67.7 g of ₁ MCaCl ₂ aqueous solution was added to 60
Gradually add to the above homomixer with heating to ℃ under stirring and add C
A dispersion medium containing a ₃ (PO ₄ ) ₂ was obtained. -Styrene 175g-2 Ethylhexyl acrylate 25g-Paraffin wax (mp 75 ° C) 60g-C.I. I. Pigment Blue 15: 3 10 g ・ Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 58,000; Mw / Mn = 3.1, acid value 70)
5 g-di-tert-butylsalicylic acid metal compound 3 g

Among the above materials, C.I. I. Pigment Blue 15: 3, di-tert-butylsalicylic acid metal compound and styrene only Ebara Milder (Ebara Corporation)
Was used for premixing. Next, all of the above materials were heated to 60 ° C., dissolved and dispersed to obtain a monomer mixture.
Further, while maintaining the temperature at 60 ° C, the polymerization initiator 2,2'-
10 g of azobis (2,4-dimethylvaleronitrile) and 1 g of dimethyl 2,2'-azobisisobutyrate were added and dissolved to prepare a monomer composition.

The above monomer composition was added to the aqueous dispersion medium prepared in the 2 liter flask of the homomixer. The monomer composition was granulated by stirring at 60 rpm for 20 minutes at 10,000 rpm using a TK homomixer in a nitrogen atmosphere. Then, while stirring with a paddle stirring blade, 6
After reacting at 0 ° C for 3 hours, polymerization was performed at 80 ° C for 10 hours.

After the polymerization reaction was completed, the reaction product was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) _2, and the mixture was filtered, washed with water and dried to obtain a toner.

The particle size of the obtained toner was measured with a Coulter counter to find that the weight average particle size was 8.5 μm and the particle size distribution was sharp. Moreover, it was confirmed by an electron microscope that the surface of the particles had a plurality of concave portions. The R / r of the toner is 1.07 and the L / L _o is 1.
05.

Further, when the cross section of the toner particles was observed by a transmission electron microscope by a dyeing ultrathin section method, it was divided into a surface layer portion mainly composed of styrene-acrylic resin and a central portion mainly composed of wax, and from the surface The particle size of 0.
It was confirmed that a wax-based phase did not exist near the surface up to a depth of 15 times.

B was added to 100 parts by weight of the obtained toner.
0.7 parts by weight of a hydrophobic silica having a specific surface area of 200 m ² / g by the ET method was externally added. 7 parts by weight of this toner,
93 parts by weight of an acrylic resin-coated ferrite carrier were mixed to prepare a developer.

Using this developer, image formation was performed with a remodeled machine obtained by remodeling a full-color copying machine (manufactured by Color Laser Copier 1 Canon). On the surface of the photoconductor 4 facing the developing sleeve 3, a dark portion (laser power M
IN) -550V, bright part (laser power MAX, (latent image part))-100V latent image was formed, and the gap between the sleeve and the surface of the photoconductor was set to 400 m. Here, the DC component of the bias power supply is -420 V, the frequency of the AC component is 1.8 KHz, and the peak-peak voltage is 1.8.
KVpp was applied for development. At this time, the volume ratio of the magnetic particles in the development area was 20%.

As a result of a running test of 20,000 sheets under the above conditions, an image density of 1.4 or more, no fog, a very high-resolution image is stably obtained, and toner cleaning failure occurs. In addition, the toner scattering in the copying machine was not noticeable.

Example 19 A toner having a weight average particle size of 8.8 μm was obtained in the same manner as in Example 17, except that the formulation of the monomer mixture was as follows.・ Styrene 180 g ・ 2-Ethylhexyl acrylate 20 g ・ Paraffin wax (mp 65 ° C.) 80 g ・ C. I. Pigment Blue 15: 3 10 g ・ Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 61,000; Mw / Mn = 6.6, acid value 70)
5 g-di-tert-butylsalicylic acid metal compound 3 g

It was confirmed that the obtained toner particles had a plurality of recesses on the surface of the toner particles. R / of toner
The r was 1.04 and the L / L _o was 1.03. When the cross section of the particles was observed, it was confirmed that there was no wax-based phase near the surface from the surface to a depth of 0.15 times the particle size of the particles.

After externally adding hydrophobic silica to this toner in the same manner as in Example 17, 5 parts by weight of this toner and an average particle size of 4
Acrylic resin-coated ferrite carrier 95 having a size of 5 μm, a fine powder amount of 400 mesh or less is 16% by weight, and a coarse powder amount of 250 mesh or more is 1.0% by weight.
Parts by weight were mixed to obtain a developer.

A running test was conducted in the same manner as in Example 17 using the obtained developer. As a result, fog was not noticeable and an image having a very high resolution was stably obtained. When the surface of the carrier was observed, the spent was a little worse than that in Example 17, but was at a practical level.

Example 20 A toner having a weight average particle diameter of 8.2 μm was obtained in the same manner as in Example 18, except that the monomer mixture was formulated as follows.・ Styrene 180 g ・ 2-Ethylhexyl acrylate 20 g ・ Paraffin wax (mp 65 ° C.) 80 g ・ C. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 62,000; Mw / Mn = 5.5, acid value 70)
5 g-di-tert-butylsalicylic acid metal compound 3 g

It was confirmed that the obtained toner particles had a plurality of concave portions on the surface. The R / r of the toner is 1.
And L / _Lo was 1.04. Also, when the cross section of the particle was observed, it was found that the particle diameter of 0.1
It was confirmed that the wax-based phase did not exist in the vicinity of the surface up to the depth of 5 times.

Hydrophobic silica was externally added to this toner in the same manner as in Example 17, and then a developer was obtained in the same manner as in Example 18.

Using the developer thus obtained,
As a result of carrying out a running test on 20,000 sheets in the same manner as in Example 18, as a result, an image having an image density of 1.4 or more, no fog and a very high resolution was stably obtained.

Comparative Example 16 0.25 g of γ-aminopropyltrimethoxysilane was added to 1200 ml of ion-exchanged water, 5 g of hydrophilic colloidal silica was added, and the mixture was heated to 60 ° C. and 10,000 rpm at TK homomixer. Dispersed for 15 minutes. Further, a 1 / 10N aqueous HCl solution was added to adjust the pH in the system to 6.・ Styrene 180 g ・ 2-Ethylhexyl acrylate 20 g ・ Paraffin wax (mp 75 ° C) 80 g ・ C. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 55,000; Mw / Mn = 10.2, acid value 7
0) 2g-di-tert-butylsalicylic acid metal compound 3g

The above formulation was heated to 60 ° C. in a container and TK
Using a homomixer, the mixture was dissolved and dispersed to obtain a monomer mixture. Further, the polymerization initiators dimethyl 2,2′-azobisisobutyrate 1 g and 2, while maintaining the temperature at 60 ° C.
2'-azobis (2,4-dimethylvaleronitrile) 1
0 g was added and dissolved to prepare a monomer composition.

The above monomer composition was placed in a 2 liter flask containing an aqueous dispersion medium, and the mixture was placed in a nitrogen atmosphere and charged at 6
6 at 9,000 rpm using TK homomixer at 0 ° C
The mixture was stirred for 0 minutes to granulate the monomer composition. Thereafter, polymerization was carried out at 60 ° C. for 20 hours while stirring with a paddle stirring blade. After the completion of the polymerization reaction, the reaction product was cooled, NaOH was added to dissolve the colloidal silica, and the polymerized toner was obtained by filtering, washing with water and drying.

The weight average particle diameter of the obtained toner is 8.9 μm.
And had a sharp particle size distribution. In addition, it was confirmed that the particles were somewhat irregular. R / r of toner
Was 1.02 and L / L _o was 1.03. However, when observing the cross section of the particles, a phase mainly composed of wax was present near the surface layer, and in the region where the thickness to the surface was thinner than 0.15 times the particle size, there were 10 wax particles 1 and the interface was not clear as compared with Example 18.

Hydrophobic silica was externally added to this toner in the same manner as in Example 18, and then a developer was obtained in the same manner as in Example 18.
Using the developer thus obtained, a running test was carried out in the same manner as in Example 18. As a result, especially in a high temperature and high humidity environment, the inside of the machine became soiled due to toner scattering as the running progressed, and the image density was also increased. It was too high to adjust. At this time, when the surface of the carrier and the surface of the developing sleeve were observed, the contamination with the toner composition was remarkable.

Example 21 A toner having a weight average particle size of 8.7 μm was obtained in the same manner as in Example 17, except that the monomer mixture was formulated as follows. -Styrene 175g-2-Ethylhexyl acrylate 25g-Paraffin wax (mp 75 ° C) 10g-C.I. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 45,000; Mw / Mn = 3.0, acid value 50)
5 g-di-tert-butylsalicylic acid metal compound 3 g

It was confirmed that the obtained toner particles had a plurality of concave portions on the surface. R / r of toner is 1.0
3 and L / L _o was 1.03. Also, when the cross section of the particle was observed, it was found that the particle diameter of 0.15
It was confirmed that the wax-based phase did not exist in the vicinity of the surface up to the double depth.

Hydrophobic silica was externally added to this toner in the same manner as in Example 17, and then the same carrier as that used in Example 17 was mixed to obtain a developer. Using the developer thus obtained, a running test was carried out in the same manner as in Example 17, and as a result, no fog was observed and an image having a very high resolution was stably obtained. When the surface of the carrier was observed, the spent was about the same as in Example 18, which was at a practical level.

Comparative Example 17 0.25 g of γ-aminopropyltrimethoxysilane was added to 1200 ml of ion-exchanged water, 5 g of hydrophilic colloidal silica was added, and the mixture was heated to 60 ° C. and 10,000 rpm at TK homomixer. Dispersed for 15 minutes. Further, a 1 / 10N aqueous HCl solution was added to adjust the pH in the system to 6.・ Styrene 180 g ・ 2-Ethylhexyl acrylate 20 g ・ Paraffin wax (mp 75 ° C) 80 g ・ C. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 610,000; Mw / Mn = 10.2, acid value 7
0) 2g-di-tert-butylsalicylic acid metal compound 3g

The above materials were heated to 60 ° C. in a container and TK
It was dissolved and dispersed by using a formula homomixer to obtain a monomer mixture. Further, the polymerization initiators dimethyl 2,2′-azobisisobutyrate 1 g and 2, while maintaining the temperature at 60 ° C.
2'-azobis (2,4-dimethylvaleronitrile) 1
0 g was added and dissolved to prepare a monomer composition.

The above monomer composition was placed in a 2 liter flask containing the above aqueous dispersion medium, and the mixture was placed in a nitrogen atmosphere at 60 ° C. using a TK homomixer at 9,000 r.
It stirred at pm for 60 minutes, and granulated the monomer composition. Thereafter, polymerization was carried out at 60 ° C. for 20 hours while stirring with a paddle stirring blade. After the completion of the polymerization reaction, the reaction product was cooled, NaOH was added to dissolve the colloidal silica, and the toner was obtained by filtering, washing with water and drying.

The weight average particle diameter of the obtained toner is 9.2 μm.
And had a sharp particle size distribution. In addition, it was confirmed that the particles were somewhat irregular. R / r of toner
Was 1.02 and L / L _o was 1.03. However, when observing the cross section of the particles, a phase mainly composed of wax also exists near the surface layer, and in the region where the thickness to the surface is thinner than 0.15 times the particle size, there are 20 wax particles among the 20 particles. 3 and the interface was not clear as compared with Example 17.

Hydrophobic silica was externally added to this toner in the same manner as in Example 17, and then the same carrier as that used in Example 17 was mixed to obtain a developer. A running test was performed in the same manner as in Example 17 using the developer thus obtained. Especially in high temperature and high humidity environment, as the running progresses, the toner scattering becomes dirty inside the machine,
Since the influence on the image also came out, running 8,000
I canceled it with 0 sheets. At this time, when the carrier surface was observed, the carrier spent was remarkable.

Example 22 A toner having a weight average particle size of 8.3 μm was obtained in the same manner as in Example 18, except that the monomer mixture was formulated as follows. -Styrene 175g-2-Ethylhexyl acrylate 25g-Paraffin wax (mp 75 ° C) 10g-C.I. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate copolymer (Mw = 577,000; Mw / Mn = 3.3, acid value 50)
5 g-di-tert-butylsalicylic acid metal compound 3 g

It was confirmed that the obtained toner particles had a plurality of concave portions on the surface. R / r of toner is 1.0
3 and L / L _o was 1.03. Further, when the cross section of the toner particles was observed, it was confirmed that there was no phase mainly composed of wax in the vicinity of the surface from the surface to a depth of 0.15 times the particle diameter of the particles.

Hydrophobic silica was externally added to this toner in the same manner as in Example 18 to obtain a toner. 6 parts by weight of this toner,
94 parts by weight of a ferrite carrier coated with a silicone resin was mixed to prepare a developer.

Using this developer, image formation was carried out by a modified machine obtained by modifying a commercially available full-color copying machine (Color Laser Copier 1 made by Canon). On the surface of the photoconductor 4 facing the developing sleeve 3, a latent image of −610V dark area and −190V bright area is formed as an electrostatic latent image, and the gap between the sleeve and the surface of the photoconductor is set to 400 μm. Here, the DC component of the bias power supply is -500 V, the frequency of the AC component is 1.2 KHz, and the peak-peak voltage is 1.2 KVp.
It was applied as p and developed. At this time, the volume ratio of the magnetic particles in the developing area was 20%.

As a result of a running test of 20,000 sheets under the above conditions, an image having an image density of 1.35 or more, almost no fog, and an image having a very high resolution was stably obtained.

Example 23 A 0.1 M Na ₃ PO ₄ aqueous solution and a 1 M CaCl ₂ aqueous solution were prepared, and a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) was prepared.
(Manufactured by Mitsui Chemical Co., Ltd.), 451 g of 0.1 M Na ₃ PO ₄ and 709 g of ion-exchanged water were added, and the mixture was stirred at 12000 rpm. 1M
67.7 g of an aqueous CaCl ₂ solution was heated to 70 ° C. and gradually added while stirring with the homomixer to obtain a Ca ₃ (PO ₄ ) ₂ dispersion liquid. Styrene 170 parts by weight Butyl acrylate 30 parts by weight Paraffin wax (mp 65 ° C.) 35 parts by weight Styrene-methacrylic acid copolymer 6 parts by weight Phthalocyanine blue 12 parts by weight Di-tert-butylsalicylate metal Compound 3 parts by weight

The above composition was heated to 60 ° C. and premixed using an Ebara Milder (manufactured by Ebara Corporation). Further, while maintaining at 60 ° C., 10 parts by weight of a polymerization initiator dimethyl 2,2′-azobisisobutyrate was added and dissolved to prepare a monomer composition. 2 monomer compositions
It was put into a Ca ₃ (PO ₄ ) ₂ dispersion liquid in a liter flask. The bath temperature at this time was 60 ° C., the TK homomixer rotation speed was 10,000 rpm, and a granulated product of the monomer composition was obtained 20 minutes after the addition. Then, while stirring with paddle stirring, the reaction was carried out at 60 ° C. for 3 hours, the temperature was further raised to 80 ° C., and the reaction was carried out for 10 hours to complete the polymerization. After the polymerization reaction,
The reaction product was cooled, and 54 g of 5N hydrochloric acid was added to the mixture to produce Ca ₃
(PO ₄ ) ₂ was dissolved, filtered, washed with water, and dried to obtain Toner A.

The particle diameter of the obtained toner A was measured with a Coulter counter to find that the weight average particle diameter (D4) was 8.1.
It had a sharp particle size distribution in μm. In addition, it was confirmed by an electron microscope that the surface of the toner particles had a plurality of recesses. R / r of toner is 1.08
And L / _Lo was 1.26. Furthermore, when the cross section of the toner particles was observed by a transmission electron microscope by a dyeing ultrathin section method, it had a capsule structure divided into a surface layer part mainly composed of styrene-acrylic resin and a central part mainly composed of wax. 0.15 of the particle size from the surface
It was confirmed that the wax-based phase did not exist in the vicinity of the surface up to the double depth.

To 100 parts by weight of the obtained toner A,
0.8 part of hydrophobic silicone was externally added to obtain a toner A to which hydrophobic silica was externally added.

The toner A was evaluated using a copying machine in which the developing device of a Canon copying machine FC-2 was modified to that shown in FIG.

As a result, no fusion was observed on the developer bearing member, on the photosensitive member, etc., and no image deterioration such as fog or reduction in density was observed even after 5,000 sheets were passed. Also, the offset property was good, and no back stain was observed. The temperature of the fixing device was set at 140 ° C.

Example 24 The coloring agent of Example 23 was replaced with the graft-modified carbon black 5
Example 23, except that the amount of the metal compound di-tert-butylsalicylate was changed to 3.5 parts by weight, instead of the amount of the metal compound of Example 23.
In the same manner as in the above, a toner B was obtained. The average particle size of the toner is 8.
It was 3 μm.

0.7 parts by weight of hydrophobic silica was externally added to 100 parts by weight of toner B to obtain toner B to which hydrophobic silica was externally added. Using Toner B, Example 23
Images and durability evaluations were performed using the same developing device as described above.

As a result, a good image was obtained as in Example 23.

Example 25 Except that 4 parts by weight of styrene-methacrylic acid copolymer was used and the colorant was changed to permanent yellow NCG.
Toner C was obtained in the same manner as in Example 23. The average particle diameter of the toner was 8.7 μm. R / r of toner is 1.05
And L / L _o was 1.10.

To 100 parts by weight of the toner C, 0.65 parts by weight of hydrophobic silica was externally added to obtain a toner C to which hydrophobic silica was externally added. Using this toner C, the same developing device as in Example 23 was used, and images and durability were evaluated.

As a result, a good image was obtained as in Example 23.

Comparative Example 19 Styrene-butyl acrylate copolymer 200 parts by weight Paraffin wax (mp 65 ° C.) 35 parts by weight Styrene-methacrylic acid copolymer 6 parts by weight Phthalocyanine blue 12 parts by weight Di -Tert-butylsalicylic acid metal compound 3 parts by weight

A kneaded product having the above composition was prepared to prepare a pulverized toner. Fusing to the inside of the crusher occurred, and the crushing efficiency deteriorated. Further, the obtained pulverized product had poor fluidity and caused blocking, and it was difficult to form a toner.

Comparative Example 20 The paraffin wax of Comparative Example 19 was changed to 13 parts by weight,
Kneading, pulverizing, classifying and coloring finely pulverized product (average particle size 8.3μ
m). Toner D was obtained by externally adding 0.8 parts of hydrophobic silica to 100 parts of the blue finely pulverized product. Using this pulverized toner D and using the same developing device as in Example 23, images and durability evaluation were performed.

As a result, the image was fogged and deteriorated.
Further, fusion occurred on the developer bearing member after the durability of 3,000 sheets. Also, the fixing temperature increased by 15 ° C.

Example 26 A 0.1M aqueous solution of Na ₃ PO ₄ and a 1M aqueous solution of CaCl ₂ were prepared, and a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.)
(Manufactured by Mitsui Chemical Co., Ltd.), 451 g of 0.1 M Na ₃ PO ₄ and 709 g of ion-exchanged water were added, and the mixture was stirred at 12000 rpm. 1M
67.7 g of an aqueous CaCl ₂ solution was heated to 70 ° C. and gradually added while stirring with the homomixer to obtain a Ca ₃ (PO ₄ ) ₂ dispersion liquid. Styrene 170 parts by weight Butyl acrylate 30 parts by weight Paraffin wax (mp 70 ° C.) 50 parts by weight Styrene-methacrylic acid-methyl methacrylate copolymer (Mw / Mn = 3.1) 6 parts by weight Phthalocyanine blue 12 parts by weight Di-tert-butylsalicylic acid metal compound 3 parts by weight

The above composition was heated to 60 ° C. and premixed with an Ebara Milder (manufactured by Ebara Corporation). Further, while maintaining at 60 ° C., 10 parts by weight of a polymerization initiator dimethyl 2,2′-azobisisobutyrate was added and dissolved to prepare a monomer composition. The monomer composition was put into the Ca ₃ (PO ₄ ) ₂ dispersion liquid in the flask. At this time, the bath temperature was 60 ° C and the TK homomixer rotation speed was 1000.
It was 0 rpm, and a granulated product of the monomer composition was obtained 20 minutes after the addition. Then, while stirring with paddle stirring, the reaction was carried out at 60 ° C. for 3 hours, the temperature was further raised to 80 ° C., and the reaction was carried out for 10 hours to complete the polymerization. After the completion of the polymerization reaction, the reaction product was cooled, 54 g of 5N hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , and the resultant was filtered, washed with water, and dried to obtain a toner E.

The particle size of the obtained toner E was measured with a Coulter counter to find that the weight average particle size was 8.0 μm and the particle size was sharp. In addition, it was confirmed by an electron microscope that the surface of the toner particles had a plurality of recesses. R / r of the toner is 1.10,
L / L _o was 1.18. Furthermore, when a cross section of the toner particles was observed by a transmission electron microscope by a dyeing ultrathin section method, it was divided into a surface layer part mainly composed of styrene-acrylic resin and a central part mainly composed of wax, and the surface of the particles was It was confirmed that the wax-based phase did not exist near the surface up to a depth of 0.15 times the particle size.

To 100 parts by weight of the obtained toner E,
0.8 part by weight of hydrophobic silica having a specific surface area of 200 m ² / g according to the BET method was externally added. 7 parts by weight of this toner E to which hydrophobic silica was externally added and 93 parts by weight of a ferrite carrier coated with an acrylic resin were mixed to prepare a developer. Using this developer toner, an unfixed image was obtained with a Canon full-color copying machine CLC-500.

An unfixed image is recorded using the fixing device shown in FIG.
Has become established. Pressing against the recording material of the film of this fixing device
Surface has a critical surface tension of 20 dyne / cm,
Electric resistance is 1 × 10⁶Was Ω / cm. This fixing device
In, the temperature sensor surface temperature T of the heating element₁Is 130 ℃,
Power consumption of the resistance material of the heating part is 150W, pressure roller
The total pressure is 5 kg, and the nip between the pressure roller and the film is 4
mm, fixing processing speed set to 45 mm / sec, heat resistance
As a sheet, PTFE is a conductive material on the contact surface with the recording material.
Has a low-resistance release layer with added quality (carbon black)
A polyimide film having a thickness of 20 μm was used. This
When, the temperature T of the temperature sensor of the heating element₁Reaches 130 ° C
It took about 0.5 seconds to complete. Further at this time
Temperature T _TwoIs 126 ° C and temperature T_ThreeWas 126 ° C.

The obtained fixed image was free from toner penetration or set-off into paper, had good fixability, and had a good image without offset to the film. Further, when a continuous fixing test of 2,000 sheets was conducted under the identified fixing condition, the fixing property was good, and a good fixed image was obtained without causing an offset phenomenon to the film.

Example 27 The colorant was changed to Permant Yellow NCG and di-ter
Toner F was obtained in the same manner as in Example 26 except that the amount of t-butyl salicylate metal compound was changed to 4 parts. The average particle size of Toner F was 8.4 μm. The R / r of the toner was 1.07 and the L / L _o was 1.17.

0.7 parts by weight of hydrophobic silica was externally added to 100 parts by weight of toner F to obtain toner F to which hydrophobic silica was externally added. 7.5 parts by weight of this toner F and 93 parts by weight of an acrylic resin-coated ferrite carrier were mixed to prepare a developer. As a result of performing the fixing test in the same manner as in Example 26, a good image having no offset was obtained as in Example 26.

Example 28 A dispersion was prepared in the same manner as in Example 26. Styrene 170 parts by weight 2-Ethylhexyl acrylate 30 parts by weight Paraffin wax 40 parts by weight Styrene-methacrylic acid (Mw / Mn = 3.0)
6.5 parts by weight-Magnetic substance (titanium coupling agent 4% treatment) 140 parts by weight-Metal compound of di-tert-butylsalicylic acid 3 parts by weight

The above composition was heated to 60 ° C. and premixed using Ebara Milder (manufactured by Ebara Corporation). Further, while maintaining the temperature at 60 ° C., 10 parts by weight of a polymerization initiator dimethyl 2,2′-azobisisobutyrate was added and dissolved to prepare a monomer composition. The monomer composition was put into the Ca ₃ (PO ₄ ) ₂ dispersion liquid in the flask. At this time, the bath temperature was 60 ° C, and the rotation speed of the TK homomixer was 10,000.
It was rpm, and a granulated product of the monomer composition was obtained 20 minutes after the addition. Then, while stirring with paddle stirring,
The reaction was carried out for an hour, the temperature was further raised to 80 ° C., and the reaction was continued for 10 hours to complete the polymerization. After the completion of the polymerization reaction, the reaction product was cooled, 54 g of 5N hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) _2, and the mixture was filtered, washed with water, and dried to obtain a toner G.

The average particle diameter of the obtained toner G was measured with a Coulter counter to find that the weight average particle diameter was 9.0 μm.
And had a sharp particle size distribution. In addition, it was confirmed by an electron microscope that the surface of the toner particles had a plurality of recesses. The R / r of the toner was 1.07 and the L / L _o was 1.15. Further, when the cross section of the toner particles was observed with a transmission electron microscope by a dyed ultrathin section method, it was divided into a surface layer mainly composed of styrene-acrylic resin and a central part mainly composed of wax. It was confirmed that the wax-based phase did not exist near the surface up to a depth of 0.15 times the particle size.

To 100 parts by weight of the obtained toner G,
0.8 part by weight of hydrophobic silica having a specific surface area of 200 m ² / g according to the BET method was externally added. A developer was prepared by mixing 7 parts by weight of toner G to which hydrophobic silica was externally added and 93 parts by weight of a ferrite carrier coated with an acrylic resin. By using this developer, Canon copier N
An unfixed image was obtained with P-1215.

The unfixed image was fixed by the fixing device shown in FIG. The critical surface tension of the surface of the film of this fixing device which is pressed against the recording material was 20 dyne / cm, and the surface electric resistance was 1 × 10 ⁶ Ω / cm. In this fixing device, the temperature measuring element surface temperature T ₁ of the heating element is 140 ° C., the power consumption of the resistance material of the heating unit is 150 W, the total pressure of the pressure roller is 5 kg, the nip between the pressure roller and the film is 4 mm,
The fixing processing speed is set to 45 mm / sec, and a 20 μm thick polyimide film having a low-resistance release layer obtained by adding a conductive substance (carbon black) to PTFE on the contact surface with the recording material is used as the heat-resistant sheet. did. At this time,
The time required for the temperature measuring element surface temperature T _{1 of the} heating element to reach 140 ° C. was about 0.5 seconds. Further, the temperature T ₂ at this time was 136 ° C., and the temperature T ₃ was 136 ° C.

The obtained fixed image was free from toner infiltration and set-off into paper, and had a good fixability and a good image with no offset to the film. Further, when a continuous fixing test of 5,000 sheets was conducted under the identified fixing condition, the fixing property was good, and a good fixed image was obtained without causing an offset phenomenon to the film.

Comparative Example 20 Styrene-Butadiene Copolymer (17: 3) 200
50 parts by weight of paraffin wax (mp 70 ° C.) 6 parts by weight of styrene-methacrylic acid-methyl methacrylate copolymer 12 parts by weight of phthalocyanine blue 3 parts by weight of metal di-tert-butylsalicylate

The kneaded product having the above composition (equivalent composition to toner E) was pulverized to form a toner, but fusion and blocking occurred during pulverization, and the toner could not be formed. In the crushing method, a large amount of release agent could not be contained.

Comparative Example 21 A pulverized toner was prepared by using 15 parts as the releasing agent in Comparative Example 20. When a fixing test was conducted on this toner in the same manner as in Example 4, an offset phenomenon occurred. Moreover, the blocking resistance was also deteriorated.

[0280]

As described above, according to the toner of the present invention, a toner excellent in durability without deterioration with time is obtained,
Further, since it has excellent fixing properties, blocking resistance, charging stability, storage stability, etc., it is possible to obtain a very clear image with high image density and no roughness.

According to the image forming method of the present invention, an image having a high image density and excellent resolution can be obtained, and a stable image can be formed with no change in toner performance even when used for a long time.

Further, according to the image forming method and the heat fixing method of the present invention, an image having a high image density and free from image deterioration such as fog can be obtained.
The wait time is substantially short or short, the power consumption is low, and the offset phenomenon can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining outer shape conditions of a toner of the present invention.

FIG. 2 is a diagram illustrating a cross section of the toner of the present invention.

FIG. 3 is a diagram for explaining a maximum inscribed circle and a minimum circumscribed circle of toner.

FIG. 4 is a diagram for explaining a peripheral length of toner.

FIG. 5 is a schematic partially enlarged view of the developing device according to the present invention.

FIG. 6 is an enlarged view between a photosensitive member and a sleeve of the developing device according to the present invention.

FIG. 7 is an enlarged view between a photosensitive member and a sleeve of the developing device according to the present invention.

FIG. 8 is a schematic partial enlarged view of the developing device according to the present invention.

FIG. 9 is a schematic explanatory diagram of a heat fixing device according to the present invention.

FIG. 10 is a schematic explanatory view of another heat fixing device according to the present invention.

[Explanation of symbols]

 1 A phase (high softening point resin) 2 B phase (low softening point substance) 3 Developer carrier (sleeve) 4 Photoconductor drum 5 Toner 6 Magnetic particles 7 Bias power supply 8 Fixed magnet 9 Ear 10 Power supply

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication G03G 15/20 101 G03G 9/08 381 368 (72) Inventor Tatehiko Chiba 3-chome Shimomaruko, Ota-ku, Tokyo 30-2 Canon Inc. (72) Inventor Makoto Kambayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-61-279864 (JP, A)

Claims (26)

(57) [Claims] 1. A developer for electrostatic image development containing a toner produced by a suspension polymerization method, wherein the toner is
The toner contains 5 to 30% by weight of a low softening point substance, the toner has 0.005 to 0.2% by weight of calcium phosphate based on the toner, and the toner particles have a radius r with respect to the projection surface. The toner satisfies the relationship of 1.00 <R / r <1.20 between the maximum inscribed circle and the minimum circumscribed circle having a radius R, and the circumference L of the projection surface and the inscribed circle A developer for electrostatic charge image development, characterized in that irregularities satisfying the relation of 1.01 <L / 2πr <2.00 are formed on the toner particles between the peripheral length and 2πr. 2. The method according to claim 1, wherein the main part of the phase B mainly composed of the low softening point substance is present in the central part of the toner particle, and the area of the phase B in the cross section of the toner particle is 10 to 45%. Developer for developing electrostatic images. 3. A structure having at least two components, a high softening point resin (A) and a low softening point substance (B), separated into a phase A containing A as a main component and a phase B containing B as a main component. 3. The electrostatic charge image according to claim 1, wherein a B-based phase does not exist near the surface from the surface of the toner particle to a depth of 0.15 times the toner particle size. 4. Developer for development. 4. The dispersant used in the suspension polymerization method is Ca
₃ (PO ₄ ) ₂ and Ca ₃ (PO ₄ ) ₂ is a Ca produced by the reaction of at least two compounds in a dispersion medium.
_The developer for developing an electrostatic image according to claim 1, which is ₃ (PO ₄ ) ₃ . 5. The developer for developing an electrostatic charge image according to claim 1, wherein the low softening point substance is a low melting point wax. 6. The melting point of the low softening point substance is 30 to 130 ° C.
6. The developer for developing an electrostatic charge image according to claim 1, which is within the range. 7. A developer carrier having a magnetic brush formed of toner and magnetic particles, and applying a bias electric field formed of an AC component and a DC component to the developer carrier, and In an image forming method, a magnetic brush is formed in a developing region defined by a latent image carrier and the developer carrying member so that the volume ratio of magnetic particles is 10 to 40%, and a latent image is developed. The toner has toner particles produced by a suspension polymerization method, contains 5 to 30% by weight of a low softening point substance, and the toner has 0.005 to 0.2% by weight based on the toner. It has calcium phosphate, and the toner particles satisfy a relationship of 1.00 <R / r <1.20 between a maximum inscribed circle having a radius r and a minimum circumscribed circle having a radius R with respect to a projection surface. Is the toner that is used, and the circumference length L of the projection surface and the circumference length of the inscribed circle Between πr, 1.01 <L / 2πr <irregularities satisfying the relation of 2.00 is formed on the toner particles, the image forming method characterized by. 8. The magnetic particles have an average diameter of 20 to 80 μm, a fine powder content of 400 mesh or less is 20% by weight or less, and a coarse powder content of 250 mesh or more is 20% by weight or less. Item 10. The image forming method according to Item 8. 9. The main part of the phase B mainly composed of the low softening point substance is present in the central part of the toner particle, and the area of the phase B in the cross section of the toner particle is 10 to 45%.
2. The image forming method according to 1., 10. A structure having at least two components, a high softening point resin (A) and a low softening point substance (B), separated into a phase A containing A as a main component and a phase B containing B as a main component. The phase according to any one of claims 7 to 9, wherein a phase mainly composed of B does not exist near the surface from the surface of the toner particle to a depth of 0.15 times the toner particle diameter. Image forming method. 11. The dispersant used in the suspension polymerization method is C
a ₃ (PO ₄₎ is _{2, Ca 3 (PO 4)} 2 is Ca ₃ generated by reaction of at least two compounds in the dispersing medium
The image forming method according to claim 7, wherein the image forming method is (PO ₄ ) ₃ . 12. The image forming method according to claim 7, wherein the low softening point substance is a low melting point wax. 13. The low softening point substance has a melting point of 30 to 130.
The image forming method according to any one of claims 7 to 12, which is in the range of ° C. 14. An image forming method for developing a latent image with a non-magnetic one-component toner in a developing area between a latent image holding member and a developer bearing member facing the latent image holding member, wherein toner is supplied to the developer bearing member. And a developer coating blade provided on the downstream side of the supply roller are in pressure contact with the developer carrier, and the toner is a toner produced by a suspension polymerization method. The toner contains 5 to 30% by weight of a low softening point substance, the toner has 0.005 to 0.2% by weight of calcium phosphate based on the toner, and the toner particles are On the other hand, the toner satisfies the relationship of 1.00 <R / r <1.20 between the maximum inscribed circle of the radius r and the minimum circumscribed circle of the radius R, and the peripheral length L of the projection surface is Between the circumference of the inscribed circle and 2πr, 1.01 <L Unevenness satisfying the relationship 2.pi.r <2.00 is formed on the toner particles, the image forming method characterized by. 15. The image forming method according to claim 14, wherein the surface of the developer carrying member has a resin layer containing at least fine particles having solid lubricity. 16. The image forming method according to claim 14, wherein an alternating electric field is applied to the developer carrying member. 17. The main part of the phase B mainly composed of the low softening point substance is present in the central part of the toner particle, and the area of the phase B in the cross section of the toner particle is 10 to 45%. The image forming method according to any one of 1. 18. A structure comprising at least two components, a high softening point resin (A) and a low softening point substance (B), separated into a phase A containing A as a main component and a phase B containing B as a main component. 16. The phase having B as a main component does not exist in the vicinity of the surface of the toner particles having a depth of 0.15 times the toner particle diameter from the surface of the toner particles. Image forming method. 19. The dispersant used in the suspension polymerization method is C
a ₃ (PO ₄₎ is _{2, Ca 3 (PO 4)} 2 is Ca ₃ generated by reaction of at least two compounds in the dispersing medium
19. The image forming method according to claim 14, which is (PO ₄ ) ₃ . 20. The image forming method according to claim 14, wherein the low softening point substance is a low melting point wax. 21. The melting point of the low softening point substance is 30 to 130.
The image forming method according to any one of claims 14 to 20, which is in the range of ° C. 22. A method of heating and fixing a visible image of a toner to a recording material by using a heating member and a pressing member for bringing the recording material into close contact with the heating member via a film, wherein the toner comprises:
A toner produced by a suspension polymerization method, wherein the toner contains a low softening point substance in an amount of 5 to 30% by weight, and the toner contains 0.005 to 0.2% by weight of calcium phosphate based on the toner. The toner particles satisfy a relationship of 1.00 <R / r <1.20 between a maximum inscribed circle having a radius r and a minimum circumscribed circle having a radius R with respect to the projection surface. In addition, unevenness that satisfies the relationship of 1.01 <L / 2πr <2.00 is formed on the toner particles between the peripheral length L of the projection surface and the circumferential length 2πr of the inscribed circle. The heat fixing method is characterized in that 23. The main part of the phase B mainly composed of the low softening point substance is present in the central part of the toner particle, and the area of the phase B in the cross section of the toner particle is 10 to 45%. Heat fixing method. 24. A structure having at least two components of a high softening point resin (A) and a low softening point substance (B), which is separated into a phase A containing A as a main component and a phase B containing B as a main component. 24. The heat fixing method according to claim 22 or 23, wherein a phase having B as a main component does not exist near the surface of the toner particles from the surface to a depth of 0.15 times the toner particle diameter. . 25. The heat fixing method according to claim 22, wherein the low softening point substance is a low melting point wax. 26. The low softening point substance has a melting point of 30 to 130.
The heat fixing method according to any one of claims 22 to 25, which is in the range of ° C.