JP2002278160A - Electrophotographic toner, developer and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic color developing toner excellent in safety, free of the deterioration of a charged state, not causing filming on a photoreceptor, a developer layer thickness regulating member and a developing sleeve after continuous printing and capable of stabilizing the electrostatic charge and conveyance of the toner and to provide two-component and one- component developers. SOLUTION: In the electrophotographic toner obtained by using at least a bonding resin, an electrostatic charge controlling agent and a masterbatch treated colorant as principal components, mixing these with additives if necessary and carrying out toner formation, (I) the bonding resin is a polyester resin and/or a polyol resin, (II) a masterbatch pigment is so prepared as to ensure 0.01-5.0% drying loss at 110 deg.C and <=0.5% drying loss at 70 deg.C after kneading when the pigment is mixed with the bonding resin while adding water and this mixture is heated, kneaded and freed of the water and (III) the electrostatic charge controlling agent is a plastic electrostatic charge controlling agent having a sulfonate-containing monomer, an aromatic monomer having an electron withdrawing group and a (meth)acrylic ester monomer as constitutional units.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to electrophotography, electrostatic recording,
The present invention relates to an electrophotographic toner used as a developer for developing an electrostatic image in electrostatic printing and the like, a developer using the toner, and an image forming method.

[0002]

2. Description of the Related Art A developer used in electrophotography, electrostatic recording, electrostatic printing, and the like is, for example, once applied to an image carrier such as a photosensitive member on which an electrostatic image is formed in a developing process. After being adhered and then transferred from the photoreceptor to a transfer medium such as transfer paper in a transfer step, it is fixed on the paper surface in a fixing step. At this time, as a developer for developing the electrostatic charge image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer (a magnetic toner, a non-magnetic Toner) is known. In the two-component development method, the developer deteriorates due to toner particles adhering to the carrier surface, and the toner concentration in the developer decreases because only the toner is consumed. Therefore, there is a disadvantage that the developing device becomes large. on the other hand,
The one-component developing method has no such drawbacks and has advantages such as downsizing of the apparatus, so that the developing method is becoming mainstream.

In recent years, office automation and colorization in offices have been further advanced, and not only copying of conventional manuscripts consisting only of characters, but also manuscripts including graphs and the like created by a personal computer are output by a printer and used for presentation. Opportunities to copy a large number of documents as materials are increasing. Many of printer output images are solid images, line images, and halftone images, and accordingly, the market demand for image quality is changing, and demands for high reliability and the like are further increasing.

Conventionally, electrophotographic processes using a one-component developer are classified into a magnetic one-component developing system using a magnetic toner and a non-magnetic one-component developing system using a non-magnetic toner. The magnetic one-component developing method uses a developer carrier provided with a magnetic field generating means such as a magnet inside, holds a magnetic toner containing a magnetic substance such as magnetite, and develops a thin layer by a layer thickness regulating member. In recent years, many of them have been put to practical use in small printers and the like. On the contrary,
In the non-magnetic one-component developing method, since the toner does not have a magnetic force, a toner supply roller or the like is pressed against the developer carrier to supply the toner onto the developer carrier and electrostatically hold the toner.
The layer is regulated and developed by the layer thickness regulating member.
It has the advantage of being able to cope with color because it does not contain a colored magnetic material.Because it does not use a magnet for the developer carrier, it is possible to reduce the weight and cost, and in recent years, it has been practically used in small full-color printers etc. It is starting to be done.

However, there are still many problems to be improved in the one-component developing system. In the two-component developing method, a carrier is used as a means for charging and conveying toner,
After the toner and the carrier are sufficiently stirred and mixed in the developing device, the toner and the carrier are conveyed to the developer carrier and developed, so that even when used for a relatively long time, stable charging and conveyance can be maintained, and It is easy to cope with high-speed developing devices. On the other hand, in the one-component developing method, since there is no stable charging and conveying means such as a carrier, charging and conveying failure due to long-time use or high speed are likely to occur. That is, in the one-component developing method, after the toner is conveyed onto the developer carrying member, the toner is thinned and developed by the layer thickness regulating member, but the toner and the developer carrying member, the layer thickness regulating member and the like are charged by friction. Since the contact and frictional charging time with the member is very short, the amount of low-charge and reverse-charge toner tends to increase more than in the two-component developing method using a carrier. In particular, in a non-magnetic one-component developing method, a means for conveying toner (developer) by at least one toner conveying member and developing an electrostatic latent image formed on a latent image carrier by the conveyed toner is usually used. However, at that time, the thickness of the toner layer on the surface of the toner conveying member must be reduced as much as possible. This is true even when a two-component developer having a very small carrier diameter is used, and particularly when a one-component developer is used and a toner having a high electric resistance is used as the toner. Since the toner must be charged by the developing device, the layer thickness of the toner must be significantly reduced. This is because if the toner layer is thick, only the vicinity of the surface of the toner layer is charged, and it is difficult to uniformly charge the entire toner layer. For this reason, the toner is required to maintain a more rapid charging speed and an appropriate charging amount.

For this reason, conventionally, a charge control agent has been added to stabilize the charge of the toner. The charge control agent functions to control the frictional charge amount of the toner and maintain the frictional charge amount. Typical examples of the negatively chargeable charge control agent include monoazo dyes, salicylic acid, naphthoic acid, metal salts and complex salts of dicarboxylic acids, diazo compounds, and complex compounds with boron. Examples of the control agent include a quaternary ammonium salt compound, an imidazole compound, nigrosine, and an azine dye. However, since these charge control agents are colored, there is a problem that the hue changes when used in a color toner. In addition, since such a charge controlling agent has poor compatibility with the binder resin, those present on the surface of the toner, which are greatly involved in the charging, are likely to be detached, causing variations in the charging of the toner, the development sleeve, and the photosensitive drum. There are drawbacks such as body filming that easily contaminates. For this reason, in the past, good images were obtained at the initial stage,
The phenomenon that the image quality gradually changes and the background fog and bleeding occur occurs.In particular, when applied to color copying and used continuously while replenishing toner, the charge amount of the toner is reduced, and the initial copy image is reduced. The image had a remarkably different color tone, and had a drawback that the image forming unit called a process cartridge had to be replaced at an early stage with about several thousand sheets because it could not withstand long-term use. As a result, the burden on the environment was large, and the user was also troublesome.
Furthermore, since many of them contain heavy metals such as chromium, they have recently become a problem in terms of safety.

[0007] To solve the above problems, Japanese Patent Application Laid-Open Nos. 63-88564 and 63-18476 disclose the following.
No. 2, JP-A-3-56974, JP-A-6-2
No. 30609 discloses a resin charge control agent having improved compatibility with a binder resin, transparency of a toner-fixed image, and safety. Since these resin charge control agents have good compatibility with the binder resin, they are excellent in stable chargeability and transparency. However, these resin charge control agents are monoazo dyes,
Compared with a toner using a metal salt or a metal complex salt of salicylic acid, naphthoic acid, or dicarboxylic acid, there is a defect that the charge amount and the charge speed are inferior. Although the chargeability is improved by increasing the amount of the resin charge control agent added, the toner fixability (low-temperature fixability, anti-offset property) is adversely affected. Further, these compounds have high environmental stability (humidity resistance) of the charge amount. Therefore, there is also a problem that background fog (ground stain) is easily generated.

Therefore, Japanese Patent Application Laid-Open Nos. Hei 8-30017, Hei 9-171271, Hei 9-221
896, JP-A-11-218965,
Copolymers of a monomer containing an organic acid salt such as a sulfonate group and an aromatic monomer having an electron withdrawing group have been proposed. However, due to the hygroscopicity and adhesiveness that are considered to be caused by the monomer containing an organic acid salt such as a sulfonate group, a sufficient charge amount is secured, but the dispersion in the binder resin is not sufficient,
The effect of suppressing the variation in the charge of the toner over a long period of time and the effect of preventing the filming of the developing sleeve and the photoconductor are not sufficient. Further, in order to further improve the compatibility with a styrene-based resin or a polyester-based resin as a binder resin, a monomer containing an organic acid salt such as a sulfonate group, an aromatic monomer having an electron-withdrawing group, and a styrene-based monomer. Copolymers with polyester monomers have also been proposed,
The effects of maintaining the charge amount over a long period of time and preventing filming of the developing sleeve and the photoconductor are not sufficient. In particular, as a binder resin for a full-color toner, a polyester resin or a polyol resin, which is suitable in terms of color development and image strength, is insufficient.

In recent years, the demand for printers has been expanding, and miniaturization, high-speed operation, and low cost of the apparatus have been progressing, and higher reliability and longer life of the apparatus have been demanded. It is required to be able to maintain,
These resin charge control agents cannot maintain the charge control effect, and contaminate the developing sleeve and the layer thickness regulating members (blades and rollers), resulting in a problem that the charging performance of the toner is reduced and the photoconductor is filmed. .

On the other hand, an electrophotographic color toner used for forming a color image is generally constituted by dispersing various chromatic dyes or pigments in a binder resin.
In this case, the performance required for the toner to be used is stricter than that for obtaining a black image. That is, as a toner, in addition to mechanical and electrical stability against external factors such as impact and humidity, proper color development (coloring degree) and light transmittance (transparency) when used in an overhead projector (OHP) are used. )Is required.

[0011] As a colorant using a pigment,
JP-A-49-46951, JP-A-52-1702
There is one described in Japanese Patent Publication No. However, although pigment-based color toners are excellent in light resistance, on the other hand, there is a problem that the degree of coloring (color-forming property) and the transparency are inferior due to poor dispersibility of the pigment in the binder resin.

Therefore, as a method for improving the dispersibility of the pigment in the binder resin, a first-stage kneading of a mixture of the binder resin and the pigment together with an organic solvent is carried out at a temperature lower than the melting temperature of the binder resin in advance. A technique of obtaining a color toner by adding a binder resin and a charge controlling agent and then heating and kneading the second stage (JP-A-9-101632); a binder resin having a weight average molecular weight of 40,000 or less; A toner comprising a coloring agent comprising a flushing pigment using a coloring resin (JP-A-4-39671); a solvent; a first binder resin soluble in the solvent; and a solvent insoluble in the solvent. After mixing the colorant particles and dispersing the colorant particles in the binder resin while applying a shearing force at a temperature of 50 to 100 ° C. under pressure, the solvent is removed to remove the colorant. Colored binder resin composition in which particles are dispersed It has been proposed to add a binder resin and a charge control agent, and heat-knead and knead the second stage to obtain a toner (JP-A-4-230770). ing.

However, although the methods disclosed in the above three publications improve the dispersion of the pigment, any of the methods uses a solvent. This reduces the charge amount of the toner in a special environment such as use in a high-temperature environment, and causes problems such as toner scattering in a developing unit in the two-component developing system, and toner drop due to poor thin layer formation in the one-component developing system. It has recently become clear from the study by the present inventors that it causes the background fog to increase during toner replenishment.

[0014]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention solves the compatibility of a charge control agent in a binder resin,
It is excellent in coloring degree and transparency, has a stable charge amount even during long-term use, has little background fog, has no charge deterioration under high temperature environment, and has excellent stability in electrophotographic toner, developer and image formation. It provides a method. In particular, in a one-component developing method in which a thin layer of toner is formed on a toner conveying member (developing sleeve) by a layer thickness regulating member and development is performed, there is no change in toner chargeability after continuous printing, which is equivalent to an initial image. Toner for electrophotography that can achieve image quality of
It is an object to provide a developer and an image forming method.

[0015]

Means for Achieving the Object In order to solve the above-mentioned problems, the present inventors have focused on a method of processing a masterbatch of a colorant subjected to a masterbatch treatment, and a component and a composition ratio of a charge control agent, and have studied diligently. . As a result, the charge amount is stable even during long-term use, and toner scattering and poor thin layer formation in the developing section in a high-temperature environment, and contamination and filming of the developing roll and the layer regulating member in the non-magnetic one-component system. It has been found that an electrophotographic toner, a developer, and an image forming method without the above can be obtained.

That is, according to the present invention, at least a binder resin, a charge controlling agent, and a masterbatch-treated colorant are used as main components, and these are melt-kneaded and pulverized, and an external additive is used as necessary. The toner for electrophotography is a toner for electrophotography, wherein the binder resin, the charge controlling agent, and the colorant subjected to master batch processing are as follows. (I) a binder resin is a polyester and / or a polyol resin; (II) a master batch pigment is a master batch kneading in which a pigment is dispersed in a binder resin, and a dry powder pigment is used as the pigment; Water is added when the binder resin is mixed, the mixture is heated and kneaded to remove the water added at the time of mixing, and the loss on drying at 110 ° C. after kneading is from 0.01 to
(III) a charge control agent containing a sulfonate group-containing monomer, an aromatic monomer having an electron withdrawing group, and an acrylic acid ester monomer and / or Or a resin charge control agent containing a methacrylic acid ester monomer as a constituent unit The electrophotographic toner to which the present invention is applied is applicable to all toners (color toner, black toner) manufactured by a usual melt-kneading and pulverizing method. It is possible.

Examples of the sulfonic acid group-containing monomer constituting the resin charge control agent of the present invention include an aromatic sulfonic acid group-containing monomer and an aliphatic sulfonic acid group-containing monomer. Examples of the aromatic sulfonic acid group-containing monomer include vinyl sulfonic acid, allyl vinyl sulfonic acid,
Alkali metal salts such as acrylamide-2-methylpropanesulfonic acid and methacryloyloxyethylsulfonic acid, alkaline earth metal salts, amine salts and quaternary ammonium salts. Examples of the aliphatic sulfonic acid group-containing monomer include alkali metal salts such as styrenesulfonic acid, sulfophenylacrylamide, sulfophenylmaleimide, and sulfophenylitaconimide, alkaline earth metal salts, amine salts, and quaternary ammonium salts. . Salts of heavy metals (nickel, copper, zinc, mercury, chromium, etc.) are not preferred in terms of safety.

Examples of the aromatic monomer having an electron-withdrawing group include styrene-substituted products such as chlorostyrene, dichlorostyrene, bromostyrene, fluorostyrene, nitrostyrene, and cyanostyrene; chlorophenyl (meth) acrylate; bromophenyl (meth) acrylate; Substituted phenyl (meth) acrylate such as nitrophenyl (meth) acrylate and chlorophenyloxyethyl (meth) acrylate, and phenyl (meth) acrylamide such as chlorophenyl (meth) acrylamide, bromophenyl (meth) acrylamide and nitrophenyl (meth) acrylamide Substituent, chlorophenylmaleimide, dichlorophenylmaleimide, nitrophenylmaleimide,
Substituted phenylmaleimides such as nitrochlorophenylmaleimide; substituted phenylitaconimides such as chlorophenylitaconimide, dichlorophenylitaconimide, nitrophenylitaconimide, and nitrochlorophenylitaconimide; and substituted phenylvinyl ethers such as chlorophenylvinylether and nitrophenylvinylether. . In particular, substituted phenylmaleimide and substituted phenylitaconimide substituted with a chlorine atom or a nitro group are preferable in terms of charging properties and filming resistance.

The acrylate and / or methacrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate and (meth) acrylate. Isobutyl acrylate, stearyl (meth) acrylate,
Dodecyl (meth) acrylate, 2- (meth) acrylate
Ethylhexyl and the like.

Examples of the aromatic vinyl monomer include styrene, vinyl toluene, α-methylstyrene and the like.

The addition of a sulfonic acid group-containing monomer as a monomer constituting the resin charge control agent of the present invention improves the negative charge imparting effect of the resin charge control agent. (Temperature and humidity stability)
It is known to be used as a copolymer of an aromatic monomer or the like having an electron-withdrawing group, but it may be used in the order of several thousand sheets. However, there is a problem that contamination of the developing sleeve and the layer thickness regulating members (blades and rollers) and filming of the photoreceptor occur, so that the charging stability and high image quality of the toner are not sufficiently maintained, and the productivity is reduced. . In order to compensate for such disadvantages, as a binder resin for a full-color toner, a coloring resin, a polyester resin or a polyol resin suitable from the viewpoint of image strength,
By using a copolymer containing three kinds of monomers of a sulfonate group-containing monomer, an aromatic monomer having an electron-withdrawing group, and an acrylate and / or methacrylate ester monomer as a resin charge control agent, it can be used for a long time. Excellent in charging and environmental stability, no contamination of the developing sleeve and layer thickness regulating members (blades and rollers), good thin layer formation, prevention of photoreceptor filming, high image quality, high productivity A photographic toner is obtained.

It is presumed that these effects are due to the following reasons. That is, the combined use of a sulfonic acid group-containing monomer and an aromatic monomer having an electron withdrawing group enhances the effect of imparting a negative charge, and the use of acrylate and / or methacrylate monomers further enhances the environmental stability of charging. In addition to improving the resin properties, the resin hardness is increased and the pulverizability is improved, and there is no contamination of the developing sleeve and the layer thickness regulating members (blades and rollers). By combining the resin with a polyester resin or a polyol resin which is suitable from the viewpoints of color development and image strength, an appropriate dispersibility can be obtained and an electrophotographic toner having a sharp charge distribution can be obtained.

The composition ratio of the monomer in the resin charge control agent of the present invention is such that the sulfonic acid group-containing monomer is 1 to 30% by weight, more preferably 2 to 20% by weight. When the amount of the sulfonic acid group-containing monomer is less than 1% by weight, the rise of charge and the amount of charge are not sufficient, and the image is likely to be affected.
If the content exceeds 30% by weight, the environmental stability of charging deteriorates,
The charge amount at high temperature and high humidity is low, and the charge amount at low temperature and low humidity is high, and the charge stability and high image quality of the toner are not sufficiently maintained. Further, there is a problem that contamination of the developing sleeve and the layer thickness regulating members (blades and rollers) and filming of the photoreceptor are liable to occur, and the productivity at the time of toner production by the kneading / pulverizing method is reduced.

The aromatic monomer having an electron withdrawing group is 1 to
It is 80% by weight, more preferably 20 to 70% by weight.
When the amount of the aromatic monomer having an electron-withdrawing group is less than 1% by weight, the charge amount is not sufficient, and background contamination and toner scattering are likely to occur. On the other hand, if the content exceeds 80% by weight, the toner is poorly dispersed in the toner, the charge distribution of the toner is widened, the background is easily scattered, and the toner is scattered.

The content of the acrylate and / or methacrylate monomer is 10 to 80% by weight, more preferably 20 to 70% by weight. 10% by weight of acrylate and / or methacrylate monomer
If it is less than 3, sufficient environmental stability of charging cannot be obtained, the pulverizability at the time of toner production by the kneading / pulverization method is not sufficient, and the developing sleeve and layer thickness regulating members (blades and rollers) are contaminated. Also, filming of the photoconductor cannot be sufficiently prevented. If it exceeds 80% by weight, the rise of the charge and the amount of charge are not sufficient, and the image is likely to be affected.

0 to 30% by weight of an aromatic vinyl monomer,
More preferably, it is 3 to 20% by weight. When the amount of the aromatic vinyl monomer exceeds 30% by weight, the resin becomes hard, the dispersibility in the toner is reduced, the charge distribution is widened, and the background smear and the toner scattering in the machine are easily generated. Further, the fixability of the toner, particularly the color developability at the time of color mixing of the color toner, becomes poor.

The resin charge control agent of these combinations can provide a suitable dispersibility by combining with a polyester resin or a polyol resin which is suitable as a binder resin for a full-color toner in terms of color development and image strength. An electrophotographic toner having a sharp distribution can be obtained, and long-term charging stability and high image quality can be obtained.

The resin charge control agent of the present invention has better compatibility with the binder resin and is better in the resin than the charge control agents having poor industrial properties such as chromium complex or salt of salicylic acid and chromium complex or salt of alkyl salicylic acid. Although dispersed, the apparent viscosity of the resin charge controlling agent measured by a flow tester is 10 ⁴ P (10 ⁴ P).
P = 10 ⁴ g / cm · s) at a temperature of 85 to 110 ° C.
It is preferred that If the temperature is lower than 85 ° C., since the viscosity with the binder resin is different, appropriate dispersibility in the toner cannot be obtained, and not only the charge is reduced, but also the storage stability is poor and the solidification (aggregation) occurs. Cheap. In the method obtained from the production process of kneading, pulverizing and classifying, sticking in the pulverizing process is likely to occur, and the productivity is deteriorated. On the other hand, when the temperature is higher than 110 ° C., sufficient dispersibility in the toner cannot be secured, the charge distribution is widened, and background contamination and toner scattering in the machine are likely to occur. Further, the fixability of the toner, particularly the color developability at the time of color mixing of the color toner, becomes poor.

The apparent viscosity is 10 ⁴ P (10 ⁴ P = 10 ⁴ g)
/ Cm · s), the viscosity was measured using a flow tester at a load of 10 kg / cm ² , an orifice of 1 mm × 1 mm, and a temperature rising rate of 5 ° C./min, and the apparent viscosity was 10 ⁴ P (1
0 ⁴ P = 10 ⁴ g / cm · s). Shimadzu CFT-5 as a flow tester
Type 00 can be used.

The dispersion particle size of these resin negative charge control agents is
When observed with a transmission electron microscope, the major axis is 0.05 to
1.50 μm and a minor axis of 0.02 to 1.00 μm are preferred. If the major axis is greater than 1.50 μm and the minor axis is greater than 1.00 μm, the charge distribution of the toner is widened, and background contamination and toner scattering in the machine are likely to occur. When the major axis is less than 0.05 μm and the minor axis is less than 0.02 μm, the rise of charge and the amount of charge are not sufficient, and the image is likely to be affected. The weight average diameter of the toner at this time is 6.0 to 8.0 μm.

The addition amount of the resin charge control agent is preferably 0.1 to 20% by weight, and
-10% by weight is more preferred. If the amount is less than 0.1% by weight, the rising of the charge and the amount of charge are not sufficient, and the image is likely to be affected. If the content is more than 20% by weight, the dispersion is poor, the charge distribution is widened, and the background is liable to be scattered and the toner is scattered in the machine. In addition, at least one selected from the group consisting of a chromium complex or salt of salicylic acid and a chromium complex or salt of alkyl salicylic acid may be used in combination as the charge control agent.

The masterbatch pigment in the present invention uses a dry powder pigment as a pigment, adds water when mixing it with a binder resin, and heat-kneads this mixture to remove water added during mixing. The loss on drying at 110 ° C after kneading is 0.01 to 5.0%, and the loss on drying at 70 ° C is 0.5%.
% Or less, more preferably 0.01 to 1.0% at 110 ° C, and 0.1% at 70 ° C.
The greatest feature is that the kneading is performed so as to be not more than 05%.

The reason is considered to be the mechanism described below, but not all of them are clear.
However, it is presumed that the electrophotographic toner and the non-magnetic one-component developing system according to the present invention solve the above-mentioned problems without any doubt.

The primary particles of the pigment are 0.001 to 0.1 μm
However, in the state of the dry powder of the raw material, a large aggregate having a size of several μm is formed. The ideal dispersion of the pigment is to disintegrate the aggregates and break them down to primary particles. Such a kneading method by ordinary mechanical repetitive shearing is a limit. That is, poor dispersion of the pigment is nothing other than the inability to break up the aggregate.

The prerequisite for the disaggregation of the aggregates is that the surrounding resin enters the voids inside the aggregates and efficiently wets the surfaces of all the primary particles. Therefore, the point of pigment dispersion, even to the void inside the aggregate,
It depends on whether the surrounding resin can enter. However, the binder resin used for normal toner has a high melt viscosity,
In order to penetrate into the inside of the aggregate, a large amount of energy is required, and at present, the pigment is not yet the intended primary particle.

The present invention is characterized in that water is used as a method for wetting the dry powder pigment. Organic pigments generally used as colorants are hydrophobic, but the manufacturing process involves washing and drying, so that if some force is applied, water will penetrate into the pigment aggregates. It is possible.

A mixture of the pigment and resin impregnated with water in the aggregate is mixed with an open kneader so that the temperature of the kneaded material in a portion where the maximum shearing force of the kneaded material is applied becomes 100 ° C. or more. When water is kneaded in water, the water inside the aggregate reaches the boiling point instantaneously and almost explosively expands in volume, so that a force for breaking the aggregate from inside the aggregate is applied. The force from the inside of the aggregate can disintegrate the aggregate very efficiently compared to the force applied from the outside.
Further, at this time, since the resin is heated to a temperature equal to or higher than the softening point, the viscosity is reduced, and the aggregates are efficiently wetted, and at the same time, similar to the so-called flushing with water near the boiling point inside the aggregates. By being replaced with an effect,
A master batch pigment in which the pigment is dispersed in a state close to the primary particles can be obtained.

Further, the absorption of water by the pigment aggregates in the pigment mixing step prior to kneading is an exothermic reaction process, ie, a process of releasing the internal latent heat of the pigment. At this stage, heat is generated and the energy becomes more stable, and Also, in the process of evaporating water, the heat of vaporization accompanying the evaporation of water is removed from the kneaded material, so that the temperature of the kneaded material is maintained at a relatively low temperature and high viscosity, so that the shearing force is effectively applied to the pigment aggregate. It also has the effect of being added to

Further, in the present invention, the reason why water having low affinity for the pigment or the resin is used is that it is not preferable that a large amount of components such as solvent and water remain in the master batch pigment after the dispersion treatment. is there. Therefore, it is necessary to remove the added water or solvent when heating and kneading with the open kneader, but at this time, even if the boiling point is higher than when using a solvent having a high affinity for the resin or pigment. The use of water having a low affinity for the resin or the pigment can facilitate the removal. In addition, since the solvent commonly used here has a high affinity with the charge control agent used in the toner, the solvent in the toner moves under special conditions such as a high temperature environment even when a trace amount is present in the toner. / Diffusion / evaporation causes a problem that the charge amount is reduced.

In the present invention, the kneading method using water is as follows.
This is a technique clearly different from the flushing method using a surfactant which is often used in the ink field. In the masterbatch process required in the toner field, not only the dispersibility of the pigment but also all the qualities of the final toner must be maintained in a well-balanced manner. In many cases, there is a problem in charging stability when a copying machine is used continuously for a long time, and the present invention is an effective method for solving such a problem.

The measurement of the saturated water supply rate in the present invention is based on JIS
Performed according to K5101. However, water was used instead of linseed oil, and it was difficult to treat on a glass plate, so the method was performed in a sealed plastic bag. The saturated water supply rate here is the amount of water that can be supplied in 10 g of the pigment,
A saturated water supply rate of 100% indicates a state where 10 g of water is supplied.

As the kneader used in the present invention, an open kneader is desirable. In the closed kneader, water removal intended by the present invention cannot be efficiently performed. As the open-type kneader, a method using a Banbury mixer as an open type, a continuous two-roll kneader manufactured by Mitsui Mining Co., Ltd. or the like can be used in addition to the usual two-roll or three-roll.

The pigment used in the present invention preferably has a saturated water supply rate of water of 20 to 100%. If the saturated water supply rate is 20% or less, the primary particle diameter of the pigment is too large to be suitable as a toner, or water cannot enter the inside of the pigment aggregate, and the effect of the present invention is not achieved. I can't achieve it. If it is 100% or more, the amount of water becomes too large, and therefore it is not preferable for the same reason as when the amount of water is 50% by weight or more.

Examples of specific pigments include the following. Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.

As the yellow pigment, cadmium yellow,
Mineral fast yellow, nickel titanium yellow,
Navels Yellow, Naphthol Yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG and Tartrazine Lake.

Examples of orange pigments include molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.

Examples of red pigments include red, red, cadmium red, permanent red 4R, lithol red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, and brilliant carmine 3B. No.

Examples of purple pigments include Fast Violet B and Methyl Violet Lake.

Examples of the blue pigment include cobalt blue, alkali blue, Victoria Blue Lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, fast sky blue, and indanthrene blue BC.

The green pigment includes chrome green, chromium oxide, pigment green B, and malachite green lake.

These are all dry powder pigments, and one or more of them can be used.

Further, the masterbatch pigment obtained according to the present invention has a loss on drying at 110 ° C. of 0.01 to 5.
0%, more preferably, the loss on drying at 110 ° C is 0.01 to 1.0%, and the loss on drying at 70 ° C is desirably 0.05% or less. If the loss on drying at 110 ° C. is 5.0% or more, not only does the water present in the masterbatch affect the quality, but also the dispersion of the pigment becomes poor due to insufficient shearing during kneading the masterbatch. . On the other hand, in order to reduce the loss on drying at 110 ° C. to 0.01% or less, excessive shearing and heating must be applied at the time of kneading the master batch, so that a part of the binder resin is sheared and low molecular weight components are reduced. There is a problem that it increases, which is not preferable. In addition, 70 ° C
If the loss on drying of the toner is 0.05% or more, when the toner is prepared using the present master batch pigment, there is a problem that the charge amount is reduced when used in a high temperature environment, which is not preferable.

In the present invention, the loss on drying is determined by first sieving with a sieve having an opening of 0.15 to 2.0 mm in order to adjust the particle size of the sample. After leaving it to stand at the temperature for 2 hours, it was cooled in a desiccator for 0.5 hour, and the weight loss was determined.

As the binder resin used in the present invention, a polyester resin or a polyol resin which is suitable as a binder resin for a full-color toner in terms of color development and image strength is used.
In a color image, several types of toner layers are superimposed one upon another, so that the toner layer becomes thicker, and the image may be cracked or defective due to insufficient strength of the toner layer, or an appropriate gloss may be lost. For this reason, a polyester resin or a polyol resin is used to maintain appropriate gloss and excellent strength.

The polyester resin can be generally obtained by an esterification reaction between a polyhydric alcohol and a polycarboxylic acid. Among the monomers constituting the polyester resin in the present invention, examples of the alcohol monomer including tri- or higher-valent polyfunctional monomers include ethylene glycol, diethylene glycol triethylene glycol, 1,2-propylene glycol, and 1,3-propylene. Glycols such as glycol, 1,4-butadieneol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, polyoxypropylene Bisphenol A alkylene oxide adducts such as bisphenol A, other dihydric alcohols, or sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol , Tripentaerythritol, 1,2,4-butane triol, 1,2,5
Pentanetriol, glycerol, diglycerol,
2-methylpropanetriol, 2-methyl-1,2,2
Examples thereof include 4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, and other trihydric or higher polyhydric alcohols.

Among these monomers, those using bisphenol A alkylene oxide adduct as a main component monomer are particularly preferably used. Bisphenol A
When an alkylene oxide adduct is used as a constituent monomer, a polyester having a relatively high glass transition point can be obtained due to the nature of the bisphenol A skeleton, and the copy blocking resistance and the heat storage stability are improved. In addition, the presence of the alkyl groups on both sides of the bisphenol A skeleton functions as a soft segment in the polymer, and improves color developability and image strength during toner fixing. In particular, among the bisphenol A alkylene oxide adducts, those having an ethylene group or a propylene group are preferably used.

Among the monomers constituting the polyester resin in the present invention, examples of the acid monomer include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, and phthalic acid, including trifunctional or higher polyfunctional monomers. , Isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, or n-dodecenyl succinic acid, n
Alkenyl succinic acids or alkyl succinic acids such as dodecyl succinic acid, anhydrides, alkyl esters, other divalent carboxylic acids of these acids and 1,2,2
4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,2
4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid And empole trimer acids, and their anhydrides, alkyl esters, alkenyl esters, aryl esters, and other trivalent or higher carboxylic acids.

Specific examples of the alkyl group, alkenyl group or aryl ester described herein include 1, 2, 4
-Benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid trimethyl, 1,2,4-benzenetricarboxylic acid triethyl, 1,2,4-benzenetricarboxylic acid tri-n-butyl, 1,2,4-benzenetricarboxylic acid Isobutyl, tri-n-octyl 1,2,4-benzenetricarboxylate, tri-2-ethylhexyl 1,2,4-benzenetricarboxylate, tribenzyl 1,2,4-benzenetricarboxylate, 1,2,4-benzenetricarboxylic acid Tris (4-isopropylbenzyl) and the like can be mentioned.

It is known that the relationship between the chargeability of a polyester resin and the acid value is almost proportional, and it is known that the higher the acid value, the greater the negative chargeability of the resin. Also affect. That is, when the acid value is high, the charge amount becomes high under low temperature and low humidity, and the charge amount becomes low under high temperature and high humidity, the background fog, the image density, the change in color reproducibility become large, and it is difficult to maintain high image quality. . Therefore, the acid value of the polyester resin is preferably 20 KOHmg / g or less,
Further, the amount is preferably 5 KOHmg / g or less.

As the polyol resin used in the present invention, the end of the epoxy resin is capped from the viewpoints of environmental stability of charging, fixing stability, color reproducibility, gloss stability, curling prevention after fixing, and the like. Further, those having a polyoxyalkylene moiety in the main chain are preferred. For example, the epoxy resin of both terminal glycidyl groups and the two
It can be obtained by reacting an alkylene oxide adduct of a divalent phenol with a dihalide, isocyanate, diamine, diol, polyhydric phenol, or dicarboxylic acid. Of these, the reaction with a dihydric phenol is most preferable in terms of reaction stability. It is also preferable to use a polyhydric phenol or a polycarboxylic acid together with a dihydric phenol within a range not causing gelation.

The following are examples of alkylene oxide adducts of dihydric phenols at both terminal glycidyl groups used in the present invention. Examples include ethylene oxide, propylene oxide, butylene oxide, and reaction products of these mixtures with bisphenols such as bisphenol A and bisphenol F. The obtained adduct may be used after glycidylation with epichlorohydrin or β-methylepichlorohydrin. In particular, a glycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following general formula (1) is preferable.

[0062]

Embedded image (In the above formula, R is a group represented by the following formula 2, and
n and m are the number of repeating units, each being 1 or more and n
+ M = 2 to 6. )

Embedded image

As a developer, in order to impart releasability,
It is preferable to include a wax in the produced developer. The wax has a melting point of 40 to 120 ° C., preferably 50 to 110 ° C. When the melting point of the wax is too high, the fixability at low temperatures may be insufficient, while when the melting point is too low, the offset resistance and durability may decrease. The melting point of the wax is determined by a differential scanning calorimetry ( DSC). That is, the melting peak value when a few mg of a sample is heated at a constant heating rate, for example (10 ° C./min), is defined as the melting point.

Examples of the wax usable in the present invention include solid paraffin wax, micro wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketones, fatty acid metal salt wax, and fatty acid ester wax. And partially saponified fatty acid ester waxes, silicone varnishes, higher alcohols, and carnauba wax. Polyolefins such as low molecular weight polyethylene and polypropylene can also be used. In particular, a polyolefin having a softening point of 70 to 150 ° C by a ring and ball method is preferable,
Further, a polyolefin having a softening point of 120 to 150 ° C is preferable.

A method has been proposed in which toner particles and inorganic powders such as various metal oxides are mixed and used for the purpose of improving the flow characteristics, charging characteristics and the like of the toner, and are called external additives. In addition, if necessary, a method of treating with a specific silane coupling agent, a titanate coupling agent, a silicone oil, an organic acid, or the like, for the purpose of modifying the hydrophobicity, charging characteristics, etc. of the surface of the inorganic powder, coating with a specific resin A method of doing so has also been proposed. As the inorganic powder, for example, silicon dioxide (silica), titanium dioxide (titania), aluminum oxide, zinc oxide, magnesium oxide, cerium oxide, iron oxide, copper oxide, tin oxide and the like are known. Especially silica and titanium oxide fine particles and dimethyldichlorosilane,
Silica fine particles obtained by reacting with an organosilicon compound such as hexamethyldisilazane or silicone oil and replacing the silanol groups on the surface of the silica fine particles with organic groups to make them hydrophobic are used.

Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor and the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, for example, fine particles of polymethyl methacrylate, Examples include polymer fine particles produced by soap-free emulsion polymerization of polystyrene fine particles and the like. Polymer fine particles have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.
Are preferred.

As an example of the method for producing the toner according to the present invention, first, the above-mentioned dry powder pigment, binder resin, and water are sufficiently mixed by a mixer such as a Henschel mixer, and then a conventional two-roll mill is used. A master batch pigment is obtained by heating and kneading with an open kneader such as a method using a Banbury mixer as an open type in addition to the three rolls or a continuous two roll kneader manufactured by Mitsui Mining Co., Ltd. Further, the masterbatch pigment, the binder resin, the charge control agent, and the magnetic material, when used as a magnetic toner, and other additives are sufficiently mixed by a mixer such as a Henschel mixer. Mixer or continuous twin-screw extruder, for example, KTK twin-screw extruder manufactured by Kobe Steel, TEM twin-screw extruder manufactured by Toshiba Machine Co., Ltd., TEX twin-screw extruder manufactured by Japan Steel Works, Ikegai Iron Works The components are kneaded well using a PCM type twin screw extruder, a KEX type twin screw extruder manufactured by Kurimoto Tekkosho Co., Ltd., or a continuous single screw kneader such as a bus kneader such as a co-kneader. After cooling, the mixture is roughly pulverized using a hammer mill or the like, further pulverized using a fine pulverizer using a jet stream or a mechanical pulverizer, and then subjected to predetermined classification using a classifier using a swirling stream or a classifier using the Coanda effect. Classify to particle size Next, the inorganic fine powder and the toner were sufficiently mixed by a mixer such as a Henschel mixer, and then passed through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.
There is a method for obtaining the toner of the present invention.

[0068]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, parts and percentages are by weight unless otherwise specified.

Examples of Binder Resin Synthesis Example 1 Stirrer, thermometer, nitrogen inlet, falling condenser,
In a four-necked separable flask with a cooling tube, 740 g of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2,
2) 300 g of 2,2-bis (4-hydroxyphenyl) propane, 466 g of dimethyl terephthalate, 80 g of isododecenyl succinic anhydride, and 114 g of tri-n-butyl 1,2,4-benzenetricarboxylate were added together with the esterification catalyst. Under a nitrogen atmosphere, the temperature was raised to normal temperature to 210 ° C. in the first half, and the reaction was performed while stirring at 210 ° C. under reduced pressure in the latter half. Acid value 10.3 KOHmg / g, hydroxyl value 28.0 KOHm
A polyester resin (R-1) having a g / g, a softening point of 106 ° C and a Tg of 62 ° C was obtained.

Synthesis Example 2 Polyoxypropylene (2,2) -2,2-bis (4-
(Hydroxyphenyl) propane 725 g, polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 165 g, terephthalic acid 500 g, isododecenyl succinic anhydride 130 g, 1,2,4-benzenetricarboxylic acid triisopropyl 170 g were added to the flask along with the esterification catalyst. These were reacted with the same apparatus and the same recipe as in Synthesis Example 1 to obtain an acid value of 5.5 KO.
A polyester resin (R-2) having an Hmg / g, a hydroxyl value of 25.0 KOHmg / g, a softening point of 109 ° C, and a Tg of 63 ° C was obtained.

Synthesis Example 3 378.4 g of a low-molecular bisphenol A type epoxy resin (number average molecular weight: about 360) and 378.4 g of a high molecular bisphenol A type epoxy resin were placed in a separable flask equipped with a stirrer, a thermometer, a nitrogen inlet, and a condenser. (Number average molecular weight: about 270
0) 86.0 g, glycidylated bisphenol A-type propylene oxide adduct (n + m in the above general formula (1): about 2.1) 191.0 g, bisphenol F
274.5 g, 70.1 g of p-cumylphenol, and 200 g of xylene were added. 70-100 ° C under nitrogen atmosphere
, And 0.1839 g of lithium chloride was added. The temperature was further raised to 160 ° C., and xylene was distilled off under reduced pressure.
Polymerization is carried out at a reaction temperature of 0 ° C. for 6 to 9 hours to obtain an acid value of 0.0K.
A polyol resin (R-3) having an OH mg / g, a hydroxyl value of 70.0 KOH mg / g, a softening point of 109 ° C, and a Tg of 58 ° C was obtained.

Synthesis Example 4 200 parts by weight of cumene were placed in a reactor, the temperature was raised to the reflux temperature, 75 parts by weight of styrene monomer and 25 parts by weight of n-butyl acrylate were added, and 4 parts of diethylene butyl peroxide were used as an initiator. Polymerized for hours. Thereafter, cumene was removed and the acid value was 20 KOHmg / g, the softening point was 110 ° C., and the Tg
A styrene acrylic resin (R-4) at 64 ° C. was obtained.

Examples of Charge Control Agents Synthesis Example 1 600 parts of 3,4-dichlorophenylmaleimide and 100 parts of perfluorooctanesulfonic acid were copolymerized in dimethylformaldehyde (DMF) at a boiling point of 8 hours using ditertiary butyl peroxide as an initiator. did. Next, 300 parts of n-butyl acrylate was added, and graft polymerization was carried out for 4 hours using ditertiary butyl peroxide as an initiator. Then, DMF was distilled off with a reduced-pressure drier to give an apparent viscosity of 10 ⁴ Pa (= 10 ⁴ g / cm). A charge control resin C-1 having a temperature of 95 ° C. was obtained.

Synthesis Example 2 The procedure of Synthesis Example 1 was repeated except that the graft polymerization time was changed to 6 hours. Charge control resin C- whose apparent viscosity is 115 ° C
2 was obtained.

Synthesis Example 3 m-Nitrophenylmaleimide (600 parts) and 2-acrylamido-2-methylpropanesulfonic acid (100 parts) were copolymerized in dimethylformaldehyde (DMF) at a boiling point of 8 hours using ditertiary butyl peroxide as an initiator. . Then 2-ethylhexyl acrylate was added to 250
In addition, after graft polymerization for 4 hours using ditertiary butyl peroxide as an initiator, DMF was distilled off by a reduced-pressure drier to obtain a charge control resin C-3 having an apparent viscosity of 82 ° C.

Synthesis Example 4 400 parts of 3,4-dichlorophenylmaleimide and
Acrylamide-2-methylpropanesulfonic acid (100 parts) was copolymerized in dimethylformaldehyde (DMF) at a boiling point for 8 hours using ditertiary butyl peroxide as an initiator. Then, 2-ethylhexyl acrylate 20
0 parts and 50 parts of styrene were added, and graft polymerization was performed for 4 hours using di-tert-butyl peroxide as an initiator.
DMF was distilled off with a vacuum dryer, and the apparent viscosity was 110
° C was obtained.

Synthesis Example 3 400 parts of 3,4-dichlorophenylmaleimide and 2-part
Acrylamide-2-methylpropanesulfonic acid 100
The copolymer was copolymerized for 8 hours with ditertiary butyl peroxide as an initiator under a boiling point of dimethylformaldehyde (DMF), and then DMF was distilled off under reduced pressure to obtain a charge control resin C-5 having a number average molecular weight of 7,000. Was.

Synthesis Example 4 2-acrylamido-2-methylpropanesulfonic acid 1
00 parts, 250 parts of 2-ethylhexyl acrylate, and 700 parts of a styrene monomer were added, and graft polymerization was performed for 4 hours using ditertiary butyl peroxide as an initiator. Then, DMF was distilled off with a reduced pressure drier to give an apparent viscosity of 9 parts.
A charge control resin C-6 at 5 ° C. was obtained. In addition, Bontron E-84 manufactured by Orient was used as a charge control agent (C
-7)

Examples of Master Batch Preparation Example 1 Pigment: quinacridone-based magenta pigment (CI Pigment Red 122): 50 parts Binder resin: polyester resin (R-1): 50 parts Auxiliary agent: 30 parts The mixture was mixed with a mixer to obtain a mixture in which water was permeated into the pigment aggregate. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. to obtain a master batch pigment (M-1). The loss on drying was measured to be 0.02% at 110 ° C., 7
At 0 ° C, it was 0.00%.

Preparation Example 2 The same raw materials as in Preparation Example 1 were mixed with a Henschel mixer to obtain a mixture in which water was permeated into the pigment aggregates. This was kneaded for 30 minutes with two rolls set at a roll surface temperature of 110 ° C. to obtain a master batch pigment (M-2).
I got When the loss on drying was measured, it was 1.00% at 110 ° C and 0.02% at 70 ° C.

Preparation Example 3 The same raw materials as in Preparation Example 1 were mixed with a Henschel mixer to obtain a mixture in which water was permeated into the pigment aggregate. This is rolled by two rolls set at a roll surface temperature of 75 ° C.
The mixture was kneaded for 0 minutes to obtain a master batch pigment (M-3). When the loss on drying was measured, it was 5.00% at 110 ° C and 0.10% at 70 ° C.

Preparation Example 4 Pigment: copper phthalocyanine blue pigment (CI Pigment Blue 15): 50 parts Binder resin: polyester resin (R-1): 50 parts Auxiliary agent: water: 25 parts Preparation Example 1 of the above raw materials To obtain a master batch pigment (M-4). The loss on drying was measured to be 0.01% at 110 ° C and 0.00% at 70 ° C.
%Met.

Preparation Example 5 A mixture in which water was soaked in the pigment aggregate was obtained in the same manner as in Preparation Example 4. Using a continuous two-roll kneader manufactured by Mitsui Mining Co., Ltd., the front roll rotation speed is 75 rpm, the rear roll rotation speed is 50 rpm, the inlet side front roll set temperature is 90 ° C., the outlet side front roll set temperature is 50 ° C., and the residence time is 10 minutes. Kneading was carried out under the conditions to obtain a master batch pigment (M-5). The loss on drying was measured to be 0.02% at 110 ° C,
At 70 ° C, it was 0.00%.

Preparation Example 6 The same raw materials as in Preparation Example 1 were mixed with a Henschel mixer to obtain a mixture in which water was soaked in the pigment aggregate. This was kneaded for 90 minutes with two rolls set at a roll surface temperature of 130 ° C. to obtain a master batch pigment (M-6).
I got When the loss on drying was measured, it was 0.005% at 110 ° C and 0.000% at 70 ° C. In this method, not only the productivity was extremely low, but also filming occurred in the running evaluation, and running of 10K sheets or more was practically impossible.

Preparation Example 7 The same raw materials as in Preparation Example 1 were mixed with a Henschel mixer to obtain a mixture in which water was soaked in the pigment aggregates. This is kneaded for 10 minutes by two rolls set at a roll surface temperature of 110 ° C. to obtain a master batch pigment (M-7).
I got The loss on drying was measured and found to be 5.50% at 110 ° C and 0.05% at 70 ° C.

Preparation Example 8 Pigment: quinacridone-based magenta pigment (CI Pigment Red 122): 50 parts Binder resin: polyester resin (R-1): 50 parts The above raw materials were mixed with a Henschel mixer to obtain a mixture. Was. This was kneaded with two rolls set at a roll surface temperature of 130 ° C. for 45 minutes to obtain a master batch pigment (M-8). When this loss on drying was measured, 1
It was 0.00% at 10 ° C and 0.00% at 70 ° C.

Production Example 9 Pigment: quinacridone-based magenta pigment (CI Pigment Red 122): 50 parts Binder resin: polyol resin (Tr = 92 ° C.): 50 parts Water / acetone (= 50/50): 30 parts The above raw materials were mixed with a Henschel mixer to obtain a mixture in which water / acetone was permeated into the pigment aggregate. This is rolled by two rolls set at a roll surface temperature of 130 ° C.
The mixture was kneaded for 5 minutes to obtain a master batch pigment (M-9). The loss on drying was measured to be 2.00% at 110 ° C and 0.60% at 70 ° C.

Toner Production Example 100 parts of polyester resin R-1 5 parts of masterbatch pigment (M-1) 3 parts of charge control resin C-1 3 parts of the above materials were mixed by a mixer, and then melt-kneaded by a two-roll mill to obtain a kneaded material. Rolled and cooled. Thereafter, a jet plate mill (I-2 type mill; manufactured by Nippon Pneumatic Industries Co., Ltd.) using a jet mill and a wind classifier (DS classifier;
(Manufactured by Nippon Pneumatic Industries Co., Ltd.) to obtain magenta colored particles having a weight average diameter of 6.8 μm. Further, 100 parts by weight of the obtained colored particles and 1.0 part by weight of hydrophobic silica (HDK H2000, manufactured by Wacker Inc.) and hydrophobic silica (Aerosil RX-5, manufactured by Nippon Aerosil Co., Ltd.) as external additives.
0) 1.0 part by weight, hydrophobic titanium oxide (MT
-150AI) 0.5 parts by weight of a toner for electrophotography (T) by mixing 0.5 parts by weight with a Henschel mixer and passing through a mesh having an opening of 36 μm to remove coarse particles and aggregates.
-1) was obtained. Hereinafter, a toner was prepared by the same manufacturing method. Combinations of the binder resin, the masterbatch pigment, and the charge control agent are as shown below.

[0089]

[Table 1]

(Toner Evaluation Machine) A one-component developer was used as a full-color laser printer (Epsio Color 5000, manufactured by Ricoh Company, OPC belt, intermediate transfer belt, evaluation machine A), and a two-component developer was used as a full-color laser. The evaluation was performed using a copier Imagio Color 2800 (manufactured by Ricoh Company, intermediate transfer drum, intermediate transfer belt, evaluation machine B). The evaluation machine A is equipped with a developing sleeve made of an elastic body and a non-magnetic one-component developing unit made of a stainless steel blade whose thickness is regulated. Further, these evaluation machines are of a reversal development type in which the polarity of the electrostatic latent image on the photoconductor and the polarity of the developer are the same. Further, for the two-component evaluation machine B, a ferrite carrier coated with a silicone resin at an average thickness of 0.3 μm and having an average particle diameter of 50 μm was used as a carrier, and the container was rolled with 5 parts by weight of toner per 100 parts by weight of carrier. The mixture was uniformly mixed and charged using a turbuler mixer of a stirring type to prepare a developer.

(Evaluation Items) Coloring degree: A solid image having a density of 1.0 mg / cm ² was output on white paper, and the coloring degree was determined by X-write 938.
(Manufactured by X-Rite). Measure this at 5 points,
The average was determined. 2. Haze degree: Output a solid image of 1.0 mg / cm ² on an OHP sheet (OHP film PPC-FC manufactured by Ricoh Co., Ltd.) (OHP mode) using a direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd. It was measured. The smaller the value, the better the transparency. 3. Running Evaluation At 40 ° C. and (30% RH), 10,000 single-color image charts with an image area of 5% were performed. The following items were measured at the beginning and at the end. 3-1. Charge amount: In the case of a two-component developer; 6 g of the developer is weighed, charged into a sealable metal cylinder, and blown to determine the charge amount. In the case of a one-component toner, the toner was conveyed onto a developing roller (sleeve) and measured by a suction tribo measurement method under each environment. 3-2. Background stain: The white paper image was stopped during development, the developer on the photoreceptor after development was transferred to a tape, and the difference from the image density of the untransferred tape was measured by X-Rite 938. 3-3. Filming: The occurrence of toner filming on the developing roller and the photoconductor was observed. ○ indicates no filming, △ indicates filming on the streaks, ×
Is generated as a whole, and streaks appear in the image. 3-4. Toner scattering and thin layer forming property: For those using a two-component developer using the evaluator B, the toner scattering state around the developing section was confirmed. ○ means no toner scattering, △
Is not noticeable, but x is a state in which toner scattering is noticeable. In addition, for one component, the thin-layer forming property was confirmed, and those that were not different from the initial stage were evaluated as ○, those that were different from the initial stage, but whose thin-layer property was maintained, were evaluated as Δ, and those that did not form a thin layer were evaluated as ×. did.

[0092]

[Table 2]

[0093]

According to the present invention, excellent safety can be obtained in both the two-component and one-component color developing systems.
And there is no charge deterioration, and after continuous printing, there is no filming on the photoconductor, developer layer thickness regulating member or developing sleeve,
An electrophotographic toner capable of stabilizing charging and transport of the toner is obtained. In addition, since the dispersibility of the masterbatch pigment can be improved without using a low-boiling organic solvent, it is possible to achieve both transparency and improvement in the degree of coloring and stability in a special environment such as high temperature. Become.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/01 G03G 9/08 331 113 346 15/08 505 381 507 9/10 351 15/08 507X (72 Inventor Noboru Kuroda 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Hiroyuki Fushimi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Yagi Shinichiro 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Mitsuteru Kato 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. 2H005 AA01 AA06 AA08 AA21 AB04 BA06 CA02 CA03 CA08 CA21 CB07 CB13 DA02 EA03 EA05 EA07 FA07 2H030 AB02 AD01 BB23 BB63 2H077 AD06 AD13 AD14 CA11 EA03 EA14 EA15 EA16 GA02 GA13

Claims (16)

[Claims] 1. An electrophotographic toner comprising at least a binder resin, a charge controlling agent, and a masterbatch-treated colorant as a main component, and optionally adding an external additive thereto to form a toner. The toner for electrophotography, wherein the charge controlling agent and the colorant subjected to the master batch processing are as follows. (I) a binder resin is a polyester and / or a polyol resin; (II) a master batch pigment is a master batch kneading in which a pigment is dispersed in a binder resin, and a dry powder pigment is used as the pigment; Water is added when the binder resin is mixed, the mixture is heated and kneaded to remove the water added at the time of mixing, and the loss on drying at 110 ° C. after kneading is from 0.01 to
(III) a charge control agent containing a sulfonate group-containing monomer, an aromatic monomer having an electron withdrawing group, and an acrylic acid ester monomer and / or Or a resin charge control agent having a methacrylate monomer as a structural unit 2. The dispersion particle size of the resin negative charge control agent is as follows:
Major axis 0.05-1.50 μm, minor axis 0.02-1.00
2. The electrophotographic toner according to claim 1, wherein the particle diameter is .mu.m. 3. An apparent viscosity of the resin negative charge control agent measured by a flow tester is 10 ⁴ P (10 ⁴ P = 10 ⁴ g / cm).
3. The toner for electrophotography according to claim 1, wherein the temperature at which s) is 85 to 110 [deg.] C. 4. The resin charge control agent is a resin negative charge control agent, and the repeating unit of the sulfonic acid group-containing monomer is 1 to 30% by weight based on the weight of the resin negative charge control agent.
The repeating unit of the aromatic monomer having an electron-withdrawing group is 1 to 80% by weight based on the weight of the resin negative charge control agent, and the repeating unit of the acrylate monomer and / or the methacrylate ester monomer is the resin negative charge control agent. 10 to 80% by weight based on the weight, and the repeating unit of the aromatic vinyl monomer is 0 to 30% based on the weight of the resin negative charge control agent.
4. The composition according to claim 1, wherein the composition is contained in a percentage by weight.
The toner for electrophotography according to any one of the above. 5. The aromatic monomer having an electron-withdrawing group is a phenylmaleimide-substituted or phenylitaconimide-substituted compound substituted by a chlorine atom or a nitro group. A toner for electrophotography according to the above item. 6. At least a binder resin, a charge control agent, and a masterbatch-treated colorant as main components, which are melt-kneaded, pulverized, and mixed with an external additive as needed to form a toner. A method for producing an electrophotographic toner, wherein the binder resin, the charge control agent, and the colorant subjected to the master batch treatment are as follows. (I) a binder resin is a polyester and / or a polyol resin; (II) a master batch pigment is a master batch kneading in which a pigment is dispersed in a binder resin, and a dry powder pigment is used as the pigment; Water is added when the binder resin is mixed, the mixture is heated and kneaded to remove the water added at the time of mixing, and the loss on drying at 110 ° C. after kneading is from 0.01 to
(III) a charge control agent containing a sulfonate group-containing monomer, an aromatic monomer having an electron withdrawing group, and an acrylic acid ester monomer and / or Or a resin charge control agent having a methacrylate monomer as a structural unit 7. A one-component developer using the toner for electrophotography according to claim 1. 8. A two-component developer using the toner for electrophotography according to claim 1. 9. The two-component developer according to claim 8, wherein the carrier is coated with a resin. 10. A container containing the one-component developer according to claim 7. 11. A container containing the two-component developer according to claim 8. 12. An image forming apparatus having the container according to claim 10 mounted thereon. 13. A latent image forming step of forming a latent image on a latent image holding member, a developing step of developing the latent image using a developer on a developer carrying member, and transferring the developed toner image. A transfer step of transferring onto a body, and at least a fixing step of heating and fixing the toner image on the transfer body, and, as the developer,
An image forming method using the one-component developer according to claim 7. 14. A latent image forming step of forming a latent image on a latent image holding member, a developing step of developing the latent image using a developer on a developer carrying member, and transferring the developed toner image A transfer step of transferring onto a body, and at least a fixing step of heating and fixing the toner image on the transfer body, and, as the developer,
An image forming method using the two-component developer according to claim 8. 15. The method according to claim 13, wherein in the developing step, a thin layer of the developer is formed on the developer carrier, and development is performed in contact with or non-contact with the latent image holding member. Image forming method. 16. The latent image forming step, wherein the latent image formed is an electrostatic latent image divided into multiple colors, and the latent image holders correspond to the colors of the electrostatic latent image, respectively. A plurality of latent image holders, wherein in the developing step, the developer is a plurality of developers corresponding to the colors of the electrostatic latent image, and the electrostatic latent images are respectively applied to the plurality of developers. Developing on the corresponding plurality of latent image holders using a plurality of multicolor developing devices including a developing roll and a developing blade for uniformly regulating the layer thickness of the developer supplied on the developing roll, and transferring the image. 14. The method according to claim 13, wherein in the step, the transfer member is brought into contact with a plurality of latent image holding member surfaces, and the developed toner images are sequentially electrostatically transferred to the transfer member by a transfer unit.
15. The image forming method according to any one of items 15.