JPH1010774A - Production of powdery toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a powdery toner excellent in low-temp. fixability and anti- hot offsetting property. SOLUTION: Particles contg. a colorant in a resin having more than one crosslinkable functional group per one molecule on average and a wt. average mol.wt. of 50,000-400,000, a resin having a wt. average mol.wt. of 5,000 to <500,000 and a crosslinking agent for the resins as resin components are dispersed in a liq. medium, part of the resin components is converted into a bonding resin by crosslinking and the resultant partially crosslinked particles are separated from the liq. medium and dried to produce the objective toner for developing an electrostatic charge image. Since the particle diameter of this toner is easily reduced, a sharp image can be formed, and since hot offsetting causing temp. can be increased while maintaining low-temp. fixability, a wide fixing temp. region can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner used for developing an electrostatic latent image in an electrophotographic method and an electrostatic printing method, and more particularly, to a method for producing a powder toner suitable for fixing by a hot roll. About the method.

[0002]

2. Description of the Related Art As a fixing method for developing an electrostatic latent image, a method of fixing by a hot roll is generally used, and a toner used there is one capable of obtaining a clear image, and
What can fix at high speed and low temperature is strongly demanded.
In order to obtain a clear image, a small particle size toner is required.

On the other hand, fixing at a low temperature is made possible by lowering the molecular weight of the binder resin of the toner or lowering the glass transition temperature. However, on the other hand,
If the molecular weight of the binder resin is reduced, the phenomenon of hot offset, in which toner adheres to the heat fixing roll and soils the paper, becomes significant. Further, from the viewpoint of storage stability, there is a limit in lowering the glass transition temperature of the binder resin.

Therefore, in order to secure a wide fixing temperature range while achieving both low-temperature fixing property and hot offset resistance,
The binder resin requires both low molecular weight components and high molecular weight or partially crosslinked ultra-high molecular weight components.

Conventionally, a powder toner for developing an electrostatic image has been produced by a pulverization method and a polymerization method. Such a conventional technology,
Evaluation will be made from the viewpoints of reduction in particle size, low-temperature fixability, and hot offset resistance.

At present, the most common pulverization method is a method of using a combination of a low molecular weight component and a high molecular weight component as a binder resin for a toner (Japanese Patent Publication Nos. 63-32180 and 55-55).
6895), a method in which a low molecular weight component and a partially crosslinked ultra-high molecular weight component are used in combination (Japanese Patent Publication No. 60-36582,
1-2219765), and a method of crosslinking during melt kneading (Japanese Patent Publication No. 59-33907, Japanese Patent Application Laid-Open No. 06-222612, Japanese Patent Publication No. 60-38700), and the like, which are compatible with low-temperature fixability and hot offset resistance.

However, in either technique,
The high-molecular weight or partially crosslinked resin is hot-melt-kneaded, then cooled and pulverized, so that the power must be extremely enormous.

Further, the pulverization method is inherently difficult to reduce the particle size, and more difficult to produce a small particle size toner using a high molecular weight or partially crosslinked resin which is difficult to pulverize. There is also the disadvantage of doubling. In addition, if the particle size is forced to be reduced, a large amount of non-standardized fine powder is generated, and a considerable loss occurs in classification.

That is, in the pulverization method, there is a limit in reducing the particle size from the viewpoint of productivity, and in order to meet the latest demands in the market, such as the current average particle size of 10 μm, 7 μm, and 5 μm. Is not an appropriate method.

On the other hand, the polymerization method is a method in which a radical polymerizable monomer is polymerized in an aqueous medium in the presence of a colorant. Therefore, by using a crosslinkable monomer such as divinylbenzene, the molecular weight and crosslinking are relatively easy. Can be controlled. In addition, it is possible to cope with a reduction in particle size.

However, in the polymerization method toner, in order to stabilize the dispersion of particles, a compound having extremely high hydrophilicity such as a surfactant and a protective colloid must be used.
Therefore, if it is dried as it is to obtain toner particles,
Moisture absorption results in extremely poor charging stability and environmental stability.

In order to eliminate the drawback, it is necessary to wash, but it is practically impossible to completely remove it. That is, in the production by the polymerization method, there is a disadvantage that it is problematic in terms of productivity to sufficiently solve the charging stability and the environmental stability.

Incidentally, the method for producing a toner by the phase inversion emulsification method is a new technique whose basic technique has been disclosed for the first time in JP-A-05-66600 and JP-A-05-265247. An outline of the production method is a method of dispersing an organic solvent solution of a resin having a hydrophilic group and having self-water dispersing ability and a colorant in an aqueous medium to form particles.

The feature is that particles can be easily produced without consuming a large amount of energy such as pulverization, and small-sized particles can be produced very easily. A true spherical particle shape can be obtained. Further, those having a sharp particle size distribution can be easily produced. Furthermore, since neither a surfactant nor a protective colloid is used, there is no problem in charge stability and environmental stability which are disadvantages of the polymerization method.

However, according to conventional knowledge, the phase inversion emulsification method without using a surfactant or a protective colloid uses a solution of a resin in an organic solvent, so that a crosslinked resin cannot be used, and furthermore, a high molecular weight If the resin is too high in molecular weight, phase inversion emulsification is difficult. In the case of a vinyl copolymer, in order to achieve good phase inversion emulsification, the limit of the weight average molecular weight is about 200,000.

Therefore, in order to improve the hot offset resistance, a technique in which low-molecular-weight resin and high-molecular-weight resin are applied in combination and filed in Japanese Patent Application No. 07-119799,
A technique disclosed in Japanese Patent Application Laid-Open No. 06-258869, in which a toner containing a crosslinking agent produced by a phase inversion emulsification method is crosslinked at the time of fixing with a hot roll, has been proposed, but the hot offset resistance is still insufficient. . That is, the toner produced by the conventional phase inversion emulsification method has a disadvantage that the hot offset resistance is insufficient.

Therefore, as long as the prior art as described above is followed, there are no problems such as charging stability and environmental stability, it is easy to reduce the particle size, and the heat fixing properties, especially low-temperature fixing property and hot offset resistance. It is not possible to produce a toner having both excellent properties.

[0018]

The problems to be solved by the present invention are excellent in charge stability and environmental stability, easy to reduce the particle size of the particles, and heat fixing properties, especially low-temperature fixability. And a toner having excellent hot offset resistance. In particular, in the conventional phase inversion emulsification method, by improving the hot offset resistance, which is the most problem to be solved,
An object is to provide a powder toner having a wide fixing temperature range.

[0019]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have found that a high molecular weight resin having a specific weight average molecular weight, a low molecular weight resin having a specific weight average molecular weight, After preparing a liquid medium dispersion of particles containing a cross-linking agent and a resin component, preferably, after preparing an aqueous medium dispersion of particles by phase inversion emulsification, the crosslinking reaction in the particles is carried out under mild conditions. As a result, the present inventors have found that a technique which can be performed by the above method can be used to maintain the low-temperature fixing property and remarkably improve the hot offset resistance, thereby solving the problem.

That is, a specific means of the present invention is to provide a resin having a cross-linkable functional group having at least one molecule average of 1 and having a weight average molecular weight of 50,000 to 400,000, and a resin having a weight average molecular weight of 5,000. After preparing a liquid medium dispersion of particles containing a colorant therein, using a resin of less than 50,000 and a crosslinking agent of the resin as a resin component, a part of the resin component is crosslinked. This is a method for producing a powder toner in which a binder resin is used, and the obtained partially crosslinked particles are separated from a liquid medium and dried.

[0021]

Next, the present invention will be described in detail. The present invention does not carry out crosslinking by a crosslinking agent at the time of fixing, but in the state of a toner particle liquid medium dispersion liquid, and
The greatest feature is that a high molecular weight resin having a specific weight average molecular weight and a low molecular weight resin having a specific weight average molecular weight are used in combination.

The manufacturing method of the present invention basically includes the following steps. 1) a resin having a weight average molecular weight in the range of 50,000 to 400,000 having a crosslinkable functional group exceeding at least one molecular average of 1;
A step of preparing a liquid medium dispersion of particles containing a colorant therein, using a resin of less than 000 and a crosslinking agent for the resin as a resin component. 2) a step of crosslinking a part of the resin component in the particles dispersed in the liquid medium; 3) Next, a step of separating and drying the partially crosslinked particles from the liquid medium.

In the present invention, a resin having a weight average molecular weight in the range of 50,000 to 400,000 having at least a crosslinkable functional group having an average molecular weight of more than 1 is referred to as a high molecular weight resin (A1). Average molecular weight of 5,000
A resin having a molecular weight of 0 or more and less than 50,000 is converted to a low molecular weight resin (A
2), and a mixture of the high molecular weight resin (A1) and the low molecular weight resin (A2) is referred to as a mixed resin (A).

In the present invention, for the first step of preparing a liquid medium dispersion of particles, specifically, for example, the following method can be employed.

(A) A mixed resin (A) of a high molecular weight resin (A1) and a low molecular weight resin (A2) which can be made water-dispersible by neutralization, and a crosslinking agent (B) of the mixed resin (A) , A colorant (C), an organic solvent (D), and the mixed resin (A)
Of a mixture containing a neutralizing agent (E) sufficient to make the polymer water-dispersible.

(B) A method of dispersing an organic solvent solution comprising the mixed resin (A), a crosslinking agent and a colorant in a poor solvent which does not dissolve the mixed resin to produce particles.

(C) A mixture of a radical polymerizable monomer and a crosslinking agent is mixed with an aqueous medium in which a colorant is dispersed to form a high molecular weight resin (A1) and a low molecular weight resin (A2). A method of performing suspension polymerization or emulsion polymerization under the conditions.

(D) A method of dispersing an organic solvent solution comprising the mixed resin (A), a crosslinking agent and a colorant in an aqueous medium using a surfactant and / or a protective colloid.

Among the above methods (a) to (d), the methods (a) and (d) relating to the phase inversion emulsification method are preferable in that particles can be easily formed. In particular, the first method (a) is advantageous in that it does not require a separate new washing step, or requires only relatively simple and short-time washing, and has little problem in charge stability and environmental stability. Since the present invention is preferable, the configuration will be mainly described below.

In the method (a), the high molecular weight resin (A
The relationship between 1), the low molecular weight resin (A2) and the crosslinking agent (B) will be described in more detail.

The high molecular weight resin (A1) has a molecular weight of more than 1 and preferably a molecular weight of 2 in order to effect crosslinking.
It is necessary to have the above-mentioned crosslinkable functional group (a1).
Furthermore, in order to produce particles by a phase inversion emulsification method, which is a preferred method, a functional group (a
Those having both 2) are preferable. In particular, the functional group (a
Most preferably, both 1) and the functional group (a2) are carboxyl groups.

The low molecular weight resin (A2) has a cross-linkable functional group and a functional group which increases hydrophilicity by neutralization, one having no cross-linkable functional group, and one having no functional group. It does not matter which one you do. When the low-molecular-weight resin (A2) does not have a functional group that increases hydrophilicity by neutralization, the low-molecular-weight resin (A2) is mixed with a high-molecular-weight resin (A1) that can be made water-dispersible by neutralization to undergo phase inversion emulsification. By this, it is encapsulated and taken in the particles.

As the low molecular weight resin (A2) to be combined with the high molecular weight resin (A1), those having a crosslinkable functional group and a functional group which increases hydrophilicity by neutralization, or those having only a crosslinkable functional group In the case of using those having a cross-linkable functional group and a functional group that does not have a functional group that increases hydrophilicity by neutralization, it is possible to further increase the hot offset resistance more than in the case of using a compound having no functional group. it can.

However, in order to achieve good phase inversion emulsification, especially when phase inversion emulsification is performed using a large proportion of the low molecular weight resin (A2), the low molecular weight resin (A2) is also neutralized. Those having a functional group that increases hydrophilicity are preferred. At this time, the polarity of the functional group of the low molecular weight resin (A2) that increases hydrophilicity by neutralization must be the same as that of the functional group (a2) of the high molecular weight resin (A1) that increases hydrophilicity by neutralization. is there. Further, the same functional group is preferable.

The low molecular weight resin (A2) does not have to have a crosslinkable functional group, but if it has, the same one as the high molecular weight resin (A1) has. preferable.

The crosslinking agent (B) is used in combination with a crosslinking agent capable of reacting with the crosslinking functional group of the high molecular weight resin (A1) and when the low molecular weight resin (A2) has a crosslinking functional group. May be a different kind of crosslinking agent capable of reacting with the crosslinking functional group of the low molecular weight resin (A2),
Preferably they are identical. Further, it is most preferable that the high molecular weight resin (A1) and the low molecular weight resin (A2) have the same crosslinkable functional group and that only one type of crosslinker (B) is used.

That is, the functional group (a1) and the crosslinkable functional group (a) of the high molecular weight resin (A1), which increase hydrophilicity by neutralization,
2) are both carboxyl groups, and the low molecular weight resin (A2) further comprises a functional group (a
Those having a carboxyl group as both 1) and the crosslinkable functional group (a2) are most preferred.

In the present invention, the effect of cross-linking in particles by using a high molecular weight resin and a low molecular weight resin in combination is as follows.

The low-molecular-weight resin alone does not sufficiently improve the hot offset resistance, not only when the crosslinking is not performed but also when the crosslinking is performed within the particles.

Further, in the case of a single high molecular weight resin, there is a limit in the molecular weight of the resin that can be used from the viewpoint of phase inversion emulsification, and thus there is also a limit in hot offset resistance. When crosslinked in a particle using a high molecular weight resin, although the hot offset resistance is improved, the low-temperature fixability becomes insufficient because there is no low molecular weight component.

Furthermore, even when a high molecular weight resin and a low molecular weight resin are used in combination, the molecular weight of the high molecular weight resin is limited from the viewpoint of phase inversion emulsification, and the molecular weight that can be produced by solution polymerization is limited. is there. Therefore, hot offset resistance is not satisfactory.

On the other hand, as in the present invention, a method of using a high molecular weight resin and a low molecular weight resin in combination and cross-linking in the particles is performed when only the high molecular weight resin has a crosslinkable functional group. Since only the resin is crosslinked, the hot offset resistance is significantly improved. Low-temperature fixability is ensured by low molecular weight components.

Further, even if the low molecular weight resin also has a crosslinkable functional group, if the amount of the crosslinkable functional group per unit weight is substantially the same (when the crosslinkable functional group is a carboxyl group, It can be rephrased that the acid value is almost the same.) However, the number of crosslinkable functional groups in one molecule is larger in the high molecular weight resin. Therefore, the crosslinking reaction with the crosslinking agent proceeds preferentially with the high molecular weight resin. The low molecular weight resin also reacts with the cross-linking agent, but does not adversely affect the low-temperature fixability.

Further, the larger the difference in molecular weight between the high molecular weight resin and the low molecular weight resin, and the larger the difference in crosslinkable functional groups (when the crosslinkable functional group is a carboxyl group, the acid value of the high molecular weight resin). Is higher than the acid value of the low molecular weight resin.), The effect is remarkable.

That is, the toner prepared by the phase inversion emulsification method for the first time by the method of the present invention in which the high molecular weight resin and the low molecular weight resin are used in combination and cross-linking in the particles is remarkable while maintaining the low-temperature fixability. In addition, the offset resistance can be improved.

Incidentally, the resin which can eventually become the binding resin is composed of a resin having a crosslinkable functional group having at least one molecular molecule and an average of more than 1, and a crosslinking agent for the resin, and a part of the resin is crosslinked. Resin. Low molecular weight resin (A
When 2) does not have a crosslinkable functional group, it is taken into the particles without being crosslinked.

As the high molecular weight resin (A1) and the low molecular weight resin (A2) in the present invention, for example, polyester resins, epoxy resins, polyurethane resins, vinyl copolymers and the like are representative. Among them, vinyl copolymers are preferred, and aromatic vinyl copolymers are more preferred.

The high molecular weight resin (A1) and the low molecular weight resin (A
In 2), different resin types may be used, but it is preferable that the resin types be the same in terms of phase inversion emulsification, pigment dispersibility, compatibility and the like. In particular, it is most preferable that both are aromatic vinyl copolymers.

Examples of the vinyl copolymer in the present invention include copolymers obtained by copolymerizing an aromatic vinyl monomer as a preferable component and other copolymerizable monomers. Representative examples of the aromatic vinyl-based monomer include styrene, vinyltoluene, and α-methylstyrene.

As other copolymerizable monomers, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, butoxymethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, S- (meth) acrylates such as benzyl (meth) acrylate, cetyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate and isobornyl (meth) acrylate Vinyl esters such as vinyl acetate, vinyl benzoate, vinyl versatate and vinyl propionate; polymerizable nitriles such as (meth) acrylonitrile; vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, Vinyl monomers having a fluorine atom such as chlorotrifluoroethylene and (meth) acrylates having a fluorine-containing alkyl group; diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, N-vinylimidazole and N-
Tertiary amino group-containing monomers such as vinyl carbazole; 2- (2′-hydroxy-5-methacryloyloxyethylphenyl) -2H-benzotriazole,
Hydroxy-4- (2-methacryloyloxyethoxy)
UV-absorbing or antioxidant monomers such as benzophenone and 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate; N-vinylpyrrolidone, diacetone acrylamide, N-methylol acrylamide, N-butoxymethyl Functional group-containing monomers such as N-alkoxymethyl (meth) acrylamides such as (meth) acrylamide; phosphoric acid group-containing monomers such as 2-phosphoxyoxy (meth) acrylate and 4-phosphoxyoxy (meth) acrylate;
Macromonomers having one polymerizable unsaturated group at one terminal of the molecule are exemplified.

As the polymerization initiator, known peroxides and azo compounds can be used.

In the vinyl copolymer, to adjust the molecular weight of the resin so as to meet the purpose of the present invention, the amount of the polymerization initiator, the type of the polymerization initiator, the polymerization temperature, the type and the amount of the solvent to be used, and the like are described. For example, a known method can be adopted. Also, polyfunctional radically polymerizable monomers such as divinylbenzene and ethylene glycol di (meth) acrylate, polyfunctional polymerization initiators having two or more peroxy groups and two or more azo groups, The molecular weight can also be adjusted by using chain transfer agents and the like.

In the production method by the phase inversion emulsification method which can be suitably employed in the present invention, the high molecular weight resin (A1) and the low molecular weight resin (A2) are separately produced and then mixed after use. Alternatively, for example, as in an in-situ method, in a system in which a high molecular weight resin (A1) is prepared in advance,
The monomers that form the low-molecular-weight resin (A2) are reacted, or the monomers that form the low-molecular-weight resin (A2) are charged into a system in which the low-molecular-weight resin (A2) is prepared in advance and reacted to be charged. The resin (A2) is further converted into a resin (A1) to further increase the molecular weight, and the reaction of the monomers charged later is simultaneously performed. As a result, the high molecular weight resin (A
A mixture of 1) and the low molecular weight resin (A2) may be used.

A functional group (a1) that increases hydrophilicity by neutralization and a crosslinkable functional group (a) are added to the vinyl copolymer.
The method of introducing 2) will be described later.

As the polyester resin in the present invention, a compound having a carboxyl group or an ester-forming functional group such as a monobasic acid, a dibasic acid or a polybasic acid and a compound having a hydroxyl group such as a diol or a polyol are appropriately selected. And dehydration-condensed.

Examples of the dibasic acid or polybasic acid include (phthalic anhydride), isophthalic acid, terephthalic acid,
Tetrahydro (anhydride) phthalic acid, hexahydro (anhydride)
Phthalic acid, hexahydroterephthalic acid, 2,6-naphthalenedicarboxylic acid, trimellitic acid (anhydride), (anhydrous)
Hard acids such as pyromellitic acid are typical, but other soft acids such as adipic acid, succinic acid (anhydride), sebacic acid, dimer acid, and maleic acid (anhydrous) are also partially used. can do. Also, for example, dimethylolpropionic acid, p-hydroxybenzoic acid and ε-
Compounds having a hydroxyl group and a carboxyl group such as caprolactone can also be used.

Compounds having a carboxyl group that can be used other than dibasic acids or polybasic acids include lower alkyl esters of acids such as dimethyl terephthalate;
Monobasic acids such as benzoic acid, p-tert-butylbenzoic acid, rosin and hydrogenated rosin;
Macromonomers having one carboxyl group; 5-sodium sulfoisophthalic acid and dimethyl esters thereof.

As the compound having a hydroxyl group, for example,
Alkylene oxide adducts of bisphenol A, hydrogenated bisphenol A, alkylene oxide adducts of hydrogenated bisphenol A and rigid ones such as 1,4-cyclohexanedimethanol are typical, but in addition, ethylene glycol, Neopentyl glycol, propylene glycol, diethylene glycol, dipropylene glycol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol,
1,4-butanediol, 1,3-propanediol,
Diols such as 1,6-hexanediol, 1,5-pentanediol, polyethylene glycol, polypropylene glycol and polytetramethylene glycol; glycerin, trimethylolpropane, trimethylolethane, diglycerin, pentaerythritol and trishydroxyethyl isocyanurate Monoglycidyl compounds such as "Kajura E-10" (glycidyl ester of a synthetic fatty acid manufactured by Shell Chemical Industry Co., Ltd.); macromonomers having one or two hydroxyl groups at molecular terminals; and the like. Can be Part of the dibasic acid can be replaced with a diisocyanate compound.

The polyester resin in the present invention may be various modified polyester resins, for example, a vinyl-modified polyester resin grafted with vinyl monomers, a silicon-modified polyester resin, and the like.

The polyurethane resin of the present invention can be produced by reacting a polyol component with a polyisocyanate component.

As the polyol component, in addition to the diol components listed in the method for producing a polyester resin, high-molecular diols such as polyester diol, polycaprolactone diol, polycarbonate diol, and polysiloxane diol; Polyol compounds can also be used.

The polyisocyanate component includes, for example, 2,
4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate, metaxylylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, In addition to diisocyanate compounds such as hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated meta-xylylene diisocyanate and crude 4,4'-diphenylmethane diisocyanate, polyisocyanate compounds such as polymethylene polyphenyl isocyanate can also be used.

The production of the polyurethane resin may be carried out according to a conventional method. For example, a method in which the addition reaction is performed at room temperature or at a temperature of about 40 to 100 ° C. in an inert organic solvent that does not react with the isocyanate group is preferable. At that time, a known catalyst such as dibutyltin dilaurate may be used.

The epoxy resin in the present invention is typically a bisphenol A type epoxy resin. Also,
A modified epoxy resin grafted with a vinyl monomer can also be used.

The high molecular weight resin (A1) and the low molecular weight resin (A2) used in the present invention include a functional group (a1) which increases hydrophilicity by neutralization and a crosslinkable functional group having an average molecular weight of at least one. (A2) is preferable, and the type and introduction method will be described.

Examples of the functional group (a1) that increases hydrophilicity by neutralization include an amino group, particularly preferably a tertiary amino group, as a cationic group, and a phosphate group as an anionic group. , A sulfonic acid, a sulfate group, and particularly preferably a carboxyl group.

In order to introduce a preferred tertiary amino group as a cationic group into the resin, for example, in the case of a vinyl copolymer, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, vinylpyridine A method of copolymerizing a radical polymerizable monomer having a tertiary amino group such as glycidyl (meth) acrylate and a method of adding a secondary monoamine such as dibutylamine to a copolymer of a polymerizable monomer having a glycidyl group such as glycidyl (meth) acrylate And the like.

In the case of introduction into an epoxy resin, a method of adding a secondary monoamine such as dibutylamine to a glycidyl group can be used. When introduced into a polyester resin or a polyurethane resin, a tertiary amine compound having a hydroxyl group such as triethanolamine, N-methyldiethanolamine, N, N-dimethylethanolamine may be used as a part of the alcohol component during resin synthesis. I just need.

Next, an example of a method for introducing a carboxyl group, which is preferable as an anionic group, into a resin will be described.

The vinyl copolymer having a carboxyl group can be easily produced by a method of copolymerizing a polymerizable monomer composition containing a polymerizable monomer having a carboxyl group.

Examples of the polymerizable monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, monoalkyl maleates such as maleic acid monobutyl, and itaconic acids such as monobutyl itaconate. Monoalkyl acid and the like.

Other methods include adding a monoalcohol such as butyl alcohol to an acid anhydride group-containing copolymer obtained by copolymerizing a polymerizable monomer having an acid anhydride group such as maleic anhydride; It is also possible to introduce a carboxyl group into a hydroxyl group-containing vinyl copolymer obtained by copolymerizing a monomer, for example, by adding an acid anhydride group-containing compound such as maleic anhydride, phthalic anhydride or trimellitic anhydride. it can.

As the polyester resin having a carboxyl group, a compound having a carboxyl group such as a monobasic acid, a dibasic acid or a tribasic or higher polybasic acid and a compound having a hydroxyl group such as a diol or a polyol are appropriately selected. When a polyester resin is produced by dehydration condensation by a known method such as a melting method and a solvent method, the reaction may be carried out so that a carboxyl group remains. The carboxyl group is mainly
It is an unreacted carboxyl group derived from dibasic acid or polybasic acid constituting the polyester resin.

Another method for introducing a carboxyl group into a polyester resin is to add a compound containing an acid anhydride group such as maleic anhydride, phthalic anhydride or trimellitic anhydride to a linear or branched polyester resin having a hydroxyl group. Method, a polyester resin having a hydroxyl group,
Preferably, a linear polyester resin is reacted with a tetracarboxylic dianhydride such as, for example, pyrimellitic anhydride,
A method of introducing a carboxyl group and elongating a chain at the same time can be adopted.

Further, a carboxyl group can be introduced into the polyester resin by a method of graft-polymerizing a polymerizable monomer containing a polymerizable monomer having a carboxyl group as described above.

The polyurethane resin having a carboxyl group is prepared by reacting a polyol component containing a compound having both a carboxyl group and a hydroxyl group such as dimethylolpropionic acid as a component for introducing a carboxyl group with a polyisocyanate component. It can be easily manufactured.

The high molecular weight resin (A1) in the present invention comprises
For example, it is necessary to have a crosslinkable functional group (a2) in addition to a functional group (a1) that increases hydrophilicity by neutralization, such as a carboxyl group. The low molecular weight resin (A2) includes a functional group (a1) that increases hydrophilicity by neutralization, such as a carboxyl group,
And those having a crosslinkable functional group (a2) are preferred.

The resin having at least one crosslinkable functional group having an average molecular weight of 1 is used in combination with a crosslinking agent for the resin for crosslinking a part of the resin to form a binder resin. These are selected and used so that the crosslinkable functional group of the resin and the functional group involved in the crosslinking of the crosslinking agent chemically react with each other and crosslink.

The resin having at least one crosslinkable functional group having an average molecular weight of at least 1 is preferably a resin having a functional group (a1) which increases hydrophilicity by neutralization and a crosslinkable functional group (a2), and a water dispersion by neutralization. In the case of a resin that can be
With respect to the crosslinkable functional group and the crosslinker in the resin, for example, the following combinations can be employed in the present invention.

1) When the crosslinkable functional group is a carboxyl group, examples of the crosslinking agent include aminoplast resins, compounds having an average of two or more glycidyl groups in one molecule, and 1,3-dioxolane-one in one molecule. Compounds having an average of two or more 2-one-4yl groups, compounds having an average of two or more carbodiimide groups in one molecule, compounds having an average of two or more oxazoline groups in one molecule, and metal chelate compounds No.

2) When the crosslinkable functional group is a hydroxyl group, examples of the crosslinking agent include aminoplast resins, polyisocyanate compounds and blocked polyisocyanate resins.

3) When the crosslinkable functional group is a tertiary amino group, examples of the crosslinking agent include compounds having an average of two or more glycidyl groups in one molecule and 1,3-
Compounds having an average of two or more dioxolan-2-one-4-yl groups are exemplified. 4) When the crosslinkable functional group is a glycidyl group or a 1,3-dioxolan-2-one-4-yl group, examples of the crosslinking agent include compounds having an average of two or more carboxyl groups in one molecule, polyamine compounds and Polymercapto compounds and the like.

Next, a method for introducing a crosslinkable functional group into a resin will be described. When the crosslinkable functional group is a carboxyl group or a tertiary amino group, the same method as described in the section for introducing a functional group that increases hydrophilicity by neutralization may be used.

The vinyl copolymer having a hydroxyl group as a crosslinkable functional group can be easily produced by copolymerizing with a polymerizable monomer having a hydroxyl group.
Examples of the polymerizable monomer having a hydroxyl group include, for example, 2-
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, represented by "Placcel FM-2" and "Placcel FA-2" (manufactured by Daicel Chemical Industries, Ltd.) (Meth) acrylic monomers to which a lactone compound has been added; and polyethylene glycol mono (meth) acrylate monomers, polypropylene glycol mono (meth) acrylate monomers, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, and the like, are typical examples. Can be

The polyester resin having a hydroxyl group as a crosslinkable functional group can be easily produced by a dehydration condensation reaction of the polyester resin according to a known method so that the hydroxyl group remains.

The vinyl copolymer having a glycidyl group as a crosslinkable functional group can be easily produced by copolymerizing a polymerizable monomer having a glycidyl group such as glycidyl (meth) acrylate.

The vinyl copolymer having a 1,3-dioxolan-2-one-4-yl group as a crosslinkable functional group is:
It can be easily produced by copolymerizing a polymerizable monomer having a 1,3-dioxolan-2-one-4-yl group in combination. Examples of the polymerizable monomer having a 1,3-dioxolan-2-one-4-yl group include 1,3-dioxolan-2-one-4-ylmethyl (meth) acrylate and 1,3-dioxolan-2-yl. On-4-ylmethyl vinyl ether and the like can be mentioned.

In the present invention, the functional group (a1) and the cross-linkable functional group (a1), which increase hydrophilicity by neutralization, because of the ease of synthesis, handling, and design of the resin, and the ease of increasing the molecular weight or the cross-linking reaction. Preferably, both a2) are carboxyl groups and the crosslinking agent (B) is a compound having at least two glycidyl groups per molecule on average.

As typical examples of the preferable cross-linking agent (B), a compound having two or more glycidyl groups in one molecule on average, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated Glycidyl ethers of phenols such as bisphenol A epoxy resin; neopentyl glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane diglycidyl ether, sorbitol polyglycidyl ether Glycidyl ethers of various glycols and polyols; glycidyl esters such as adipic acid diglycidyl ester and phthalic acid diglycidyl ester;
A vinyl copolymer obtained by copolymerizing a polymerizable monomer having a glycidyl group such as glycidyl (meth) acrylate;
Epoxidized polybutadiene; and the like.

In the present invention, the high molecular weight resin (A1) and the crosslinking agent (B) or the high molecular weight resin (A
The reaction of 1) and the low molecular weight resin (A2) with the crosslinking agent (B) is carried out in a liquid medium, preferably in an aqueous medium, so that the temperature is preferably equal to or lower than the boiling point of water. In order to avoid this, it is preferable to carry out at a temperature not much higher than the glass transition temperature of the particles.

Compounds having two or more glycidyl groups on average per molecule, which are preferable to react under such mild conditions at a relatively low temperature, include, for example, diglycidylaniline, triglycidylparaaminophenol, triglycidylmethaminophenol, and tetraglycidylmethaminophenol. Glycidylamine compounds such as glycidylaminodiphenylmethane are preferable, and glycidylamine compounds having a glycidyl group represented by the following general formulas (1) and (2) are most preferable.

[0092]

Embedded image

(Provided that R ¹ and R ² in the formula represent an aromatic or alicyclic ring having or without a substituent, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms; and R ³ represents an alkyl group having 1 to 4 carbon atoms.)

Examples of such most preferred crosslinking agents include:
For example, N, N, N ', N'-tetraglycidyl-m-
Xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylbenzylamine, N, N-diglycidyl-α-phenylethylamine, N, N, N ′, N′- Tetraglycidyl isophorone diamine and the like are typical examples.

Of course, the compound containing a glycidyl group in the present invention is not limited only to these.

The glycidyl group contained in the crosslinking agent is preferably one having an average of 2 to 6 glycidyl groups in one molecule.
Those having 2 to 4 are more preferable. If the number of glycidyl groups is less than 2, the high molecular weight or cross-linking reaction will not proceed sufficiently, and if it is more than 6, some of the cross-linking density will be too high. Not preferred.

When the functional group (a1), which increases hydrophilicity by neutralization, and the crosslinkable functional group (a2) of the high molecular weight resin (A1) are both carboxyl groups, the amount of the carboxyl group is determined by the acid value (solid resin). KOH required to neutralize 1g per minute
In mg. Hereinafter, the same applies. ) Is 10 to 150
The range of mg (KOH) / g is preferable.

When the acid value is less than 10, the phase inversion emulsifying property in an aqueous medium is lowered, and further, the increase in the molecular weight or the crosslinking reaction does not proceed sufficiently. When the acid value is too high, the toner Are both unpreferable, because the hygroscopicity of the product becomes high.

The low molecular weight resin (A2) preferably has a functional group (a1) that increases hydrophilicity by neutralization, and may have a crosslinkable functional group (a2). When both are carboxyl groups, the amount of the carboxyl group is preferably in the range of an acid value of 10 to 150.

Further, in order to preferentially promote the crosslinking of the high molecular weight resin, it is preferable that the acid value of the high molecular weight resin (A1) is higher than that of the low molecular weight resin (A2) in the range of 0 to 100. preferable.

The high molecular weight resin (A1) and the low molecular weight resin (A
The use ratio of 2) is 5/95 to 90 /
A range of 10 is appropriate, and a range of 10/90 to 60/40 is more preferable. 10% by weight of low molecular weight resin (A2)
If it is less than this, the fixing start temperature cannot be lowered, and if the low molecular weight resin (A2) is more than 95% by weight, the hot offset resistance cannot be increased even if the crosslinking is advanced. Both are not preferred.

The weight average molecular weight of the high molecular weight resin (A1) (hereinafter, the molecular weight is represented by a value measured by gel permeation chromatography in terms of polystyrene) is 50,0.
The range of 00 to 400,000 is preferable, and
The range of 0 to 200,000 is more preferable. If the weight-average molecular weight is too low than 50,000, the hot offset resistance cannot be sufficiently increased even by crosslinking, and it is difficult to produce a product having a weight-average molecular weight higher than 400,000 by solution polymerization. Both are not preferred.

The weight average molecular weight of the low molecular weight resin (A2) is preferably from 5,000 to less than 50,000, more preferably from 20,000 to 40,000. If the weight average molecular weight is lower than 5,000, the hot offset resistance does not improve even if cross-linking is performed in combination with the high molecular weight component, and if it is higher than 50,000, the low temperature fixability cannot be secured. Both are not preferred.

The weight average molecular weight of the high molecular weight resin (A1) is more than that of the low molecular weight resin (A2) by 1%.
It is preferably at least 000 or more, more preferably 20,000 or more.
Those which are higher by 0 or more are more preferable. If the difference is less than 10,000, it is difficult to achieve both low-temperature fixability and hot offset resistance, even if a crosslinking reaction is performed.

The glass transition temperature of the high molecular weight resin (A1) measured by DSC (differential scanning calorimeter) (hereinafter, the glass transition temperature is represented by a value measured by DSC) is 40 to 80.
Those in the range of ° C are preferred.

In the case of the low molecular weight resin (A2), the glass transition temperature of the crosslinked toner particles varies depending on the glass transition temperature of the high molecular weight resin (A1) and the usage ratio.
The glass transition temperature of the low molecular weight resin (A2) may be any value as long as 80 ° C. can be secured. Generally, a range of 20 to 60 ° C. is appropriate.

The ratio of the resin having a crosslinkable functional group having an average of at least 1 in one molecule to the crosslinker is not particularly limited, but the former is a crosslinkable functional group (a
For example, in the case of a resin in which both 1) and the functional group (a2) that increases hydrophilicity by neutralization are carboxyl groups, the former (a)
The glycidyl group-containing compound is preferably used in an amount of 0.001 to 0.5 equivalent of glycidyl group to 1 equivalent of the total carboxyl group of 1) and (a2). An amount in the range of 0.01 to 0.3 equivalent is more preferable.

When the low molecular weight resin (A2) also has a crosslinkable functional group, the proportion of the crosslinking agent used is determined by the proportion of the high molecular weight resin (A2).
It is preferable to use the crosslinkable functional group of 1) and the crosslinkable functional group of the low-molecular-weight resin (A2) in the above-described ratio with respect to the total.

If the amount of the glycidyl group is less than 0.001 equivalent, the molecular weight or crosslinking becomes insufficient, and if the amount is more than 0.5 equivalent, the crosslinking proceeds excessively and the fixability of the toner becomes poor. Both are not preferred because they will decrease.

Colorant (C) used in the present invention
Any of dyes, pigments, and the like, which have been conventionally used as toner materials, can be used. Particularly representative examples include zinc white, yellow iron oxide, Hansa Yellow, Disazo Yellow, Quinoline Yellow, Permanent Yellow, Permanent Red, Bengala, Lisor Red, Pyrazolone Red, Lake Red C, Lake Red D, and Brilliant Carmine. 6B, Brilliant Carmine 3B, navy blue, phthalocyanine blue, metal-free phthalocyanine, acid value titanium, carbon black or various powders such as magnetic powder or oil-soluble dyes.

[0111] These pigments may be used in advance of a resin treatment or a coupling agent treatment in order to improve the functionality. Further, extenders such as calcium carbonate, barium sulfate, clay and kaolin may be used in combination with the above-mentioned coloring agents.

The materials constituting the toner according to the present invention have been described above. Next, a liquid medium dispersion of particles containing a colorant, which is the first production step of the present invention, is prepared. In the process, a preferred method is
The high molecular weight resin (A
1), a low-molecular-weight resin, preferably a low-molecular-weight resin (A2) that can be made water-dispersible by the neutralization, a crosslinking agent (B), a coloring agent (C), an organic solvent (D), The high molecular weight resin (A1) or the high molecular weight resin (A
A mixture containing 1) and a neutralizing agent (E) sufficient to make the mixed resin (A) of the low molecular weight resin (A2) water-dispersible,
A method of phase inversion emulsification in an aqueous medium will be described.

First, the resin (A1) and the resin (A
2) and a solution of at least one organic solvent (D) of the crosslinking agent (B) and the colorant (C) are sufficiently kneaded by a known method, and then the resin (A1) and the resin ( A2) and the crosslinking agent (B) are blended in a predetermined ratio, and phase-inversion emulsification is carried out in an aqueous medium to produce dispersed particles. At this time,
The colorant (C) may be blended after being dispersed with another resin.

Examples of the organic solvent (D) include various hydrocarbons such as toluene, xylene, benzene, n-hexane, cyclohexane and n-heptane; methanol,
Isopropanol, n-propanol, ethanol, n
-Butanol, isobutanol, sec-butanol,
alcohols such as t-butanol; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether Ether alcohols such as ethylene glycol mono-n-butyl ether; various ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; butyl acetate, ethyl acetate;
Various esters such as isopropyl acetate; various ether esters such as propylene glycol monoethyl ether acetate and ethylene glycol monoethyl ether acetate; ethers such as tetrahydrofuran;
Halogen-containing hydrocarbons such as methylene chloride; and the like.

Of these, a so-called low-boiling solvent such as acetone, methyl ethyl ketone, ethyl acetate, isopropanol and n-propanol, which can be easily removed in a step described below, is suitable. Of course, two or more solvents may be used in combination.

The solvent used for synthesizing and dissolving the high molecular weight resin (A1) and the low molecular weight resin (A2) may be different from the solvent (D) used for phase inversion emulsification in an aqueous medium. However, in order to simplify the process, it is preferable that the same solvent is used.

In order to perform phase inversion emulsification in an aqueous medium, the emulsion may be dispersed in the aqueous medium using an emulsifier or a dispersion stabilizer such as a protective colloid. It is preferable to impart a functional group that increases hydrophilicity by neutralization to the high molecular weight resin (A1) and the low molecular weight resin (A2) to form a salt structure and disperse the salt in an aqueous medium.

Above all, a resin having a carboxyl group, which is a functional group that increases hydrophilicity by neutralization, is neutralized with a basic compound so that the resin has such a hydrophilicity that the resin can be stably dispersed in an aqueous medium. The method of applying is preferable in that there are few problems in charge stability and environmental stability, and it is not necessary to separately provide a new cleaning step, or relatively simple and short-time cleaning is sufficient.

In the case where the high molecular weight resin (A1) and the low molecular weight resin (A2) use a resin which does not have water dispersibility even if it is not neutralized, a dispersion stabilizer such as an emulsifier or a protective colloid is used. It becomes an essential component, and for example, it is necessary to separately provide a new washing step.

Examples of the high molecular weight resin (A1), wherein the functional group (a1) which increases hydrophilicity by neutralization and the crosslinkable functional group (a2) having an average molecular weight of at least 1 are carboxyl groups, A resin having a carboxyl group which can be made water-dispersible by summing, and a low molecular weight resin, preferably a low molecular weight resin (A2) having a carboxyl group;
As a method for dispersing a mixture of the crosslinking agent (B), the colorant (C) and the organic solvent (D) in an aqueous medium by phase inversion emulsification, for example, the following method is appropriate.

1) After adding a neutralizing agent (E) to the mixture, it is dispersed in an aqueous medium. 2) Add neutralizing agent (E) to the mixture and then add aqueous medium to it. 3) Disperse the mixture in an aqueous medium containing a neutralizing agent (E). 4) To the mixture is added an aqueous medium containing a neutralizing agent (E).

The resin having a functional group (a1) which increases hydrophilicity by neutralization forms a salt structure by neutralizing with a necessary amount of a neutralizing agent (E) having a polarity opposite to that of the functional group (a1). However, the resin becomes a resin that can be dispersed in an aqueous medium without using an emulsifier or a dispersion stabilizer (this resin is a self-dispersing resin).

Of the above methods 1) to 4), the method 2) can make the particle size distribution of the finally obtained particles including the partially crosslinked colorant narrower. It is preferred in that respect.

As the neutralizing agent (E) used here to form a salt structure, the functional group (a1) of the high molecular weight resin (A1) which increases hydrophilicity by neutralization is an acid group. In this case, when the basic compound is the same as the functional group (a1), an acidic compound is used.

As typical examples of the basic compound that can be used, only representative ones may be mentioned, for example, volatile amines such as ammonia, triethylamine, tributylamine and dimethylethanolamine; and volatile amines such as sodium hydroxide and potassium hydroxide. Inorganic bases; and the like.
Examples of the acidic compound include organic acids such as formic acid, acetic acid, and toluenesulfonic acid, and inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid.

When an acid group is added to the low molecular weight resin (A2) as a functional group (a1) that increases hydrophilicity by neutralization, it may be handled in the same manner as the high molecular weight resin (A1).

When phase inversion emulsification is carried out in an aqueous medium, a surfactant or a dispersant such as a protective colloid may be used within a range that does not adversely affect the performance of the toner and the subsequent steps.

[0128] No special measures need to be taken as long as the shear is applied so that the mixture is homogeneously stirred when the phase inversion emulsification is carried out in the aqueous medium. In some cases, a high shear dispersion such as a homogenizer or the use of ultrasonic waves may be used.

By the way, the aqueous medium in the present invention is
Water as a main component, other as necessary, water-soluble solvent,
Represents those containing a dispersion stabilizer, a neutralizing agent, and other additives.

In controlling the particle size, which is important in the production of the toner, for example, in the case of using a carboxyl group as the functional group (a1), the preferred method of the present invention mainly uses a basic compound which neutralizes the carboxyl group. Controlled by quantity. The amount of neutralization by the basic compound
By varying from 5 to 100 mol% of carboxyl groups, preferably from 8 to 50 mol%, particles having a particle size from submicron (less than 1 μm) to about 30 μm can be easily and easily obtained. , Can be obtained arbitrarily.

The ease of controlling the particle size is one of the features of the toner production method by the phase inversion emulsification method, and the particle size of 5 μm, which is recently considered as a high resolution toner, or smaller than that required in the future. To
We can respond immediately.

The liquid dispersion of particles is subjected to a crosslinking reaction as the second step of the present invention. The crosslinking of the present invention occurs within the formed particles. The reaction at this time occurs between a resin having a crosslinkable functional group exceeding at least one molecule average and uniformly dispersed in the particles in an unreacted state, and a crosslinking agent thereof.

It is preferable that the liquid medium is an aqueous medium because the crosslinking reaction can be performed mildly. The resin in which the liquid medium of the particle dispersion is an aqueous medium and has a crosslinkable functional group exceeding at least one molecular average of 1 has a salt structure in which the functional group (a1) is neutralized with a neutralizing agent. In this case, only the other functional group (a2) substantially participates in the crosslinking, and the dispersion stability of the particle dispersion can be ensured by the crosslinking.

The crosslinking reaction is preferably carried out at a temperature not higher than the boiling point of the aqueous medium and at a temperature not much higher than the glass transition temperature of the particles in order to avoid fusion of the particles.
Generally, in the range of 40 to 100 ° C, more preferably 50 to 100 ° C.
It is preferable to carry out at a temperature in the range of 90 ° C. The crosslinking time may be any time required for the completion of the crosslinking reaction.
It is 0 minute to 24 hours, preferably 1 to 10 hours. Specifically, there is a method of maintaining the particle dispersion at a predetermined temperature for a time required for the crosslinking reaction to be completed.

As the high molecular weight resin (A1) or the high molecular weight resin (A1) and the low molecular weight resin (A2), those having at least one crosslinkable functional group (a2) having an average molecular weight of more than 1 are used. Crosslinking agent (B) for resin (A)
However, in order to react the carboxyl group with the glycidyl group under mild conditions at a relatively low temperature, as represented by the case of using a compound having at least two or more glycidyl groups on the average of one molecule, it is necessary to use glycidyl as described above. Preferably, an amine compound is used.

Also, for glycidylamine compounds and other glycidyl group-containing compounds, known catalysts such as 2-methylimidazole may be used, or secondary monoamines such as dibutylamine may be added to some of the glycidyl groups. Then, a method of imparting an autocatalytic ability to the glycidyl group-containing compound can be employed.

In the cross-linking reaction, after preparing an aqueous medium dispersion of the particles, performing various post-treatments as necessary, separating the particles from the aqueous medium and drying, the aqueous medium dispersion of the particles is removed. It may be performed at any stage after the preparation, and before the step of separating and drying the particles from the aqueous medium, but is preferably performed after the solvent is removed in order to prevent fusion of the particles. .

The preferred method of the present invention is to have a functional group (a1) that increases hydrophilicity by neutralization and a crosslinkable functional group (a2) having an average molecular weight of at least one, and the water dispersibility by neutralization. A high molecular weight resin (A1),
Having a functional group (a1) that increases hydrophilicity by neutralization and a crosslinkable functional group (a2) exceeding at least one molecular average;
Low molecular weight resin (A2) that can be made water dispersible by neutralization
And a crosslinking agent (B) for the resin (A1) and the resin (A2), a colorant (C), an organic solvent (D), and a water-dispersible resin (A1) and the resin (A2). A mixture containing a neutralizing agent (E) sufficient to obtain a resin having a crosslinkable functional group exceeding at least one molecule average obtained by phase inversion emulsification in an aqueous medium, and a crosslinking agent for the resin. After preparing an aqueous medium dispersion of particles in which a colorant is dispersed therein as a resin component, a part of the resin component is crosslinked to form a binder resin, and then the obtained part is crosslinked. This is a method for producing a powder toner in which separated particles are separated from an aqueous medium and dried.

Further, the resin (A1) and the resin (A2)
The functional group (a1) which increases hydrophilicity by neutralization and the crosslinkable functional group (a2) having an average molecular weight of at least 1 are both carboxyl groups, and the resin (A1) and the resin (A2)
Is more preferable, wherein the crosslinking agent (B) is a compound having at least one glycidyl group having an average of at least two glycidyl groups. Further, the compound having at least one glycidyl group having an average of two or more molecules is a glycidylamine,
Most preferred is a production method which is a glycidylamine having an average of 2 to 4 glycidyl groups represented by the following general formula (1) or (2) per molecule.

[0140]

Embedded image

(Provided that R ¹ and R ² in the formula represent an aromatic or alicyclic ring having or without a substituent, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms; and R ³ represents an alkyl group having 1 to 4 carbon atoms.)

Examples of post-treatment steps performed before or after the above-mentioned crosslinking step, if necessary, include a solvent removal step by distillation under reduced pressure, a filtration and washing step, and a functional group (a1) which can be made hydrophilic by neutralization. Is a step of reverse neutralizing a salt-formed functional group formed by neutralization with a neutralizing agent (E) having the opposite polarity with an acid or base having the same polarity as the functional group (a1) (for example, A step of returning a carboxyl group neutralized with a base to a carboxyl group with an acid).

Above all, in order to improve the moisture resistance of the toner to improve the charging stability and the environmental stability, a step of reverse neutralization (for example, a carboxyl group neutralized with a base is converted into a carboxyl group with an acid) The step of returning) is preferably performed. The salt formed can be easily removed by washing with water.

In the above step, for example, when the functional group (a1) is a carboxyl group, the salt-formed functional group formed by neutralization with a basic compound can be replaced with the original carboxyl group by adding an acidic compound. It can be.

After the cross-linking step and, if necessary, the post-processing step, finally, the particles are separated from the aqueous medium and dried to obtain powdery spherical toner particles. Drying may be performed by a known method, and for example, hot air drying, spray drying, freeze drying and the like can be employed.

In the present invention, the fact that the binder resin is crosslinked means that the insoluble component after Soxhlet extraction using tetrahydrofuran has a value of 0.1% by weight or more (only the resin component is used). The molecular weight of the component soluble in tetrahydrofuran and / or the molecular weight of the component soluble in tetrahydrofuran is cross-linked by the cross-linking agent, so that the used high-molecular-weight resin and low-molecular-weight resin are mixed in the same ratio. At least higher than the weight-average molecular weight measured.

The spherical toner particles thus obtained are 40
Those having a glass transition temperature in the range of -80 ° C are preferred. Further, the insoluble component obtained by Soxhlet extraction using tetrahydrofuran is preferably in the range of 0.5 to 70% by weight.

Further, regarding the molecular weight, the weight-average molecular weight of the component soluble in tetrahydrofuran is at least higher than the weight-average molecular weight measured by mixing the used high-molecular-weight resin and low-molecular-weight resin in the same ratio. There is a need.

Particularly preferred are 10 to 150 mg (K
OH) / g, the acid value based on the carboxyl group,
A weight average molecular weight ranging from 000 to 400,000;
A high molecular weight resin having a glass transition temperature in a range of 40 to 80 ° C., an acid value based on a carboxyl group of 10 to 150 mg (KOH) / g, and 5,000 to 50,000
Phase inversion emulsification and cross-linking using a low molecular weight resin having a weight average molecular weight of less than 0 and a glass transition temperature of 20 to 60 ° C. and a compound having at least one glycidyl group in one molecule on average. To obtain toner particles, the binder resin in the toner particles has a glass transition temperature in the range of 40 to 80 ° C., and the insoluble component obtained by Soxhlet extraction using tetrahydrofuran is 0.5 to 70.
% By weight, and the weight average molecular weight should be at least higher than the value measured by mixing the used high molecular weight resin and low molecular weight resin in the same ratio.

The powdery toner particles thus obtained are, if necessary, externally added with silica or the like to form a final product.

The powder toner thus obtained can be used as a powder toner for developing an electrostatic image. A powder toner mainly containing magnetic powder as a colorant is used as it is as a magnetic one-component powder toner for developing an electrostatic image, and a powder toner containing only a colorant other than magnetic powder or mainly containing it is It can be used as a non-magnetic one-component type powder toner for developing a charge image, or can be used as a two-component type developer for developing an electrostatic image by combining a carrier and each of these powder toners.

[0152]

Next, the present invention will be described more specifically with reference to comparative examples and examples. In the following, all parts and percentages are by weight.

<Reference Example> The following is a synthesis example of the resin and the crosslinking agent used.

Reference Example 1 Synthesis Example of High-Molecular-Weight Aromatic Vinyl Copolymer Having Carboxyl Group A 3-liter flask equipped with a vinyl monomer dropping device, a thermometer, a nitrogen gas inlet tube, a stirring device, and a reflux condenser. After charging 430 parts of methyl ethyl ketone, a mixed solution comprising the following polymerizable monomer and polymerization initiator was added dropwise at 80 ° C. over 3 hours.

Styrene 633 parts n-butyl acrylate 290 parts Acrylic acid 77 parts “Perbutyl O” 4 parts (radical polymerization initiator tertiary butyl peroxy-2-ethylhexanate manufactured by NOF Corporation)

Next, 3 hours and 6 hours after the completion of the dropping, 1 part of “perbutyl O” was added, respectively.
Further, after 12 hours, 15 hours and 18 hours, 2 parts of "Perbutyl O" were added. Finally, after dropping “Perbutyl O”, the reaction was further performed at 80 ° C. for 3 hours.
The reaction was terminated for a period of time. Finally, a resin solution was obtained by adjusting the non-volatile content to 50% with methyl ethyl ketone. Hereinafter, this resin is referred to as a high molecular weight resin (A1-
Abbreviated as solution 1).

Reference Example 2 Synthesis Example of High Molecular Weight Aromatic Vinyl Copolymer Having Carboxyl Group In the same manner as in Reference Example 1, 250 parts of methyl ethyl ketone were charged, and then the following polymerizable monomer and polymerization initiator Was added dropwise at 80 ° C. over 1 hour.

Styrene 648 parts n-butyl acrylate 262 parts acrylic acid 90 parts “Perbutyl O” 1 part

Next, three hours after the completion of dropping, 6
After the hour, 0.3 parts of "perbutyl O" were added in each case, and after 12 hours, 15 hours and 18 hours, 0.5 part of each "perbutyl O" was added. Nine hours after the completion of the dropwise addition, 30 minutes of methyl ethyl ketone was added.
0 parts were added. Finally, after adding “perbutyl O”, the reaction was further continued at 80 ° C. for 3 hours to complete the reaction. Finally, the non-volatile content was 4 with methyl ethyl ketone.
It was adjusted to 0% to obtain a resin solution. Hereinafter, this resin is abbreviated as a solution of the high molecular weight resin (A1-2).

Reference Example 3 Synthesis Example of Low-Molecular-Weight Aromatic Vinyl-Based Copolymer Having No Carboxyl Group
After charging 0 parts, a mixed solution comprising the following polymerizable monomer and polymerization initiator was added dropwise at 80 ° C. over 3 hours.

Styrene 600 parts Methyl methacrylate 105 parts n-butyl acrylate 295 parts “Perbutyl O” 30 parts

Next, 3 hours and 6 hours after the completion of the dropwise addition, 5 parts of “perbutyl O” was added, and the reaction was further continued at 80 ° C. for 3 hours to complete the reaction. . Finally, the non-volatile content was reduced to 5 with methyl ethyl ketone.
It was adjusted to 0% to obtain a resin solution. Hereinafter, this resin is abbreviated as a solution of the low molecular weight resin (A2-1).

Reference Example 4 Synthesis Example of Low-Molecular-Weight Aromatic Vinyl Copolymer Having Carboxyl Group
After charging 0 parts, a mixed solution comprising the following polymerizable monomer and polymerization initiator was added dropwise at 80 ° C. over 3 hours.

Styrene 621 parts n-butyl acrylate 302 parts acrylic acid 77 parts “Perbutyl O” 30 parts

Next, 3 hours and 6 hours after the completion of the dropwise addition, 5 parts of “perbutyl O” was added, and the reaction was further continued at 80 ° C. for 3 hours to complete the reaction. . Finally, the non-volatile content was reduced to 5 with methyl ethyl ketone.
It was adjusted to 0% to obtain a resin solution. Hereinafter, this resin is abbreviated as a solution of the low molecular weight resin (A2-2).

The acid values, molecular weights and glass transition temperatures of the resins prepared in Reference Examples 1 to 4 are summarized in Table 1.

[0167]

[Table 1]

Acid value: mg of KOH required to neutralize 1 g of resin solids. -Mw: weight average molecular weight measured by gel permeation chromatography. Tg: glass transition temperature measured by DSC.

Reference Example 5 Preparation Example of Crosslinking Agent A solution prepared by dissolving 63.6 parts of “TECHMORE VG3101” (phenol type trifunctional epoxy resin manufactured by Mitsui Petrochemical Industry Co., Ltd.) in 70 parts of methyl ethyl ketone was used. 6.46 parts of dibutylamine was added and reacted at 70 ° C. for 2 hours. This crosslinking agent is replaced with a crosslinking agent (B-
Abbreviated as solution 1). The average number of functional groups of the glycidyl group is 2.5.

The glycidyl group-containing crosslinking agents used in Examples and Comparative Examples of the present invention are shown in Table 2.

[0171]

[Table 2]

Description of the crosslinking agents in Table 2. B-1: a glycidyl group-containing crosslinking agent prepared in Reference Example 5.・ "TETRAD-X": N, manufactured by Mitsubishi Gas Chemical Industry Co., Ltd.
Trade name of N, N ', N'-tetraglycidyl-m-xylenediamine. BZA: Abbreviation for N, N-diglycidylbenzylamine.

<Method of Preparing Toner> Next, methods of preparing toners of Comparative Examples and Examples will be described.

(1) Production method of mill base using solution of resin synthesized in Reference Examples 1 to 4 Resin (A1-1), resin (A2-1), and resin (A
2-2) 900 parts of a methyl ethyl ketone solution having a non-volatile content of 50%, and “ELFTEX”
8 "(Carbon Black manufactured by Cabot Corporation, USA)
The parts were kneaded for 1 hour using "Eiger motor mill M-250" (pigment disperser manufactured by Eiger Japan Co., Ltd.). Next, the non-volatile content was adjusted to 50% with methyl ethyl ketone to prepare a mill base. The ratio of resin solids / pigment on this mill base is 90/10.

In the case of the solution of the resin (A1-2), using 1,125 parts of a methyl ethyl ketone solution having a nonvolatile content of 40%, the dispersion was carried out in the same manner as described above to reduce the nonvolatile content to 40%.
To prepare a mill base.

(2) Phase inversion emulsification method of Comparative Example and Example (Description of phase inversion emulsification method taking Comparative Example 1 as an example) A mill-based emulsification method prepared using a solution of high molecular weight resin (A1-1) 200 parts, 24 parts of isopropanol, and 12.5 parts of a 1N aqueous sodium hydroxide solution (to an extent of neutralizing 13% of the carboxyl groups) were added thereto, and stirred with a three-one motor. , 80 cc of ion-exchanged water was gradually added dropwise over 10 minutes to effect phase inversion emulsification. Next, 600 parts of ion-exchanged water was added. Hereinafter, the non-crosslinked toner particles of Comparative Example 1 were produced through the following post-treatment steps. Comparative Example 1 is a comparative example of a toner that uses only a high molecular weight resin having a carboxyl group and has not been crosslinked.

The solvent is removed by distillation under reduced pressure. Filter. To the cake after filtration, add 500 parts of ion-exchanged water,
Further, the pH is adjusted to 2-3 with 1N hydrochloric acid while stirring. Filter and wash with 500 parts of deionized water. The wet cake after filtration is freeze-dried.

(Description of phase inversion emulsification method taking Example 1 as an example) A mill base prepared using a solution of a high molecular weight resin (A1-1) and a solution of a low molecular weight resin (A2-2) were used. Example 1 in which cross-linking was performed using a mill base manufactured using the method described above was performed in the following procedure.

100 parts of a mill base prepared using a solution of the high molecular weight resin (A1-1), a low molecular weight resin (A2
-2) Mill-based 100 prepared using the solution of
Parts, 24 parts of isopropanol, and 12.5 parts of 1N aqueous sodium hydroxide solution (13 parts of carboxyl group).
% To neutralize. ) And as a crosslinking agent, “TET
0.27 parts of "RAD-X" was added thereto, and 80 cc of ion-exchanged water was gradually added dropwise over 10 minutes while stirring using a three-one motor to emulsify phase inversion. Next, 600 parts of ion-exchanged water was added. Less than,
Through the post-treatment steps described above, the crosslinked toner particles of Example 1 were produced.

At this time, the amount of the crosslinking agent used was 1
0.3 parts by weight with respect to 00 parts by weight, and glycidyl group is about 0.02 parts per equivalent of carboxyl group.
Eight equivalents. Hereinafter, the crosslinked toner particles of Example 1 were produced through the following post-treatment steps. Example 1 is an example of a toner in which a high-molecular weight resin having a carboxyl group and a low-molecular weight resin having a carboxyl group are used in a 50/50 solid content weight ratio to perform a cross-linking reaction.

The solvent is removed by distillation under reduced pressure. Add 400 cc of ion-exchanged water and stir with 6
The crosslinking reaction is performed at 0 ° C. for 8 hours. To the cake after filtration, add 500 parts of ion-exchanged water,
Further, the pH is adjusted to 2-3 with 1N hydrochloric acid while stirring. Filter and wash with 500 parts of deionized water. The wet cake after filtration is freeze-dried.

(Phase inversion emulsification method of other comparative examples and examples) 100 parts of mill base solids (200 parts of mill base is weighed if the non-volatile content of the mill base is 50%. Comparison of using high molecular weight resin and low molecular weight resin together) Examples and examples are
Weigh so that the total of the mill base solids of the high molecular weight resin and the low molecular weight resin is 100 parts. ), The powder toners of Comparative Example 2 and Examples 1 to 6 were prepared in the same manner as in Comparative Example 7 when no crosslinking was performed, and in the same manner as in Example 1 when crosslinking was performed. .

Since the phase inversion emulsification was performed so that the volume average particle diameter became 6 to 9 μm, the amount of the 1N aqueous sodium hydroxide solution for neutralizing the carboxyl group was different in each of the comparative examples and examples. . However, the difference is not large, and is generally 10 to 10
The amount was 15% neutralized.

All of the powder toners of Comparative Examples and Examples of the present invention were subjected to phase inversion emulsification so that the volume average particle diameter was in the range of 6 to 9 μm.

(Summary of toner production conditions) The mixing ratio of the high molecular weight resin and the low molecular weight resin in the solid content, the type of the crosslinking agent, and the amount of the crosslinking agent used (the solid content of the high molecular weight resin and the low molecular weight resin is 1)
Usage for 00 parts. ), The number of equivalents of the glycidyl group of the crosslinking agent with respect to 1 equivalent of the carboxyl group, crosslinking conditions, and the like are shown in Tables 3 to 5.

(3) Fixing Test of Toner “R-972” (silica fine particles manufactured by Nippon Aerosil Co., Ltd.) was added in an amount of 0.5% to the freeze-dried powder toners prepared in Comparative Examples and Examples. After the addition, the powder toner 2
Using a mixture of 2.5 parts and 427.5 parts of a commercially available ferrite carrier, an image was formed on paper so that the ID value became 1.5 or more.

The ID value is “Macbeth RD-918”
(Printing reflection densitometer manufactured by Macbeth, USA).

The image output and fixing test are described in "Imagio D
A250 "(copier made by Ricoh Co., Ltd.) was disassembled into an image output section and a fixing section, and a test was conducted using a modified one.

(Evaluation Criteria for Fixing Property) Fixing start temperature: 130 mm /
Fixing was performed at a speed of 2 seconds by passing through a heated roll whose surface temperature was controlled. Apply cellophane tape to the image after heat fixing,
This was applied under a load of 100 g / cm ² and then peeled off, and its ID value was measured. The fixing start temperature is an ID value after performing a cellophane tape peeling test.
It refers to the surface temperature of the hot roll when it becomes 90% or more of the ID value before performing the cellophane tape peeling test.

Hot offset resistance: The paper on which an image is output is passed through a heat roll (silicon oil non-coating type) whose surface temperature is controlled at a speed of 130 mm / sec. The hot offset resistance temperature refers to a temperature immediately before hot offset occurs. Hot offset refers to a phenomenon in which toner adheres to a heat fixing roll, and the toner re-transfers to the next adhered paper to stain the paper.

The evaluation of the fixing start temperature and the hot offset resistance was carried out by setting the fixing temperature in increments of 5 ° C.
° C.

[0192]

Table 3 (Comparative example in the case of cross-linking or non-cross-linking with low molecular weight resin or high molecular weight resin alone)

[0193]

[Table 4]

[0194]

[Table 5]

(Explanation of Test Conditions, etc.) Resin compounding ratio: The resin solid content ratio of high molecular weight resin (A1) / low molecular weight resin (A2). -Crosslinking agent amount: The solid content of the curing agent is 100 parts by weight of the total solid content of the high molecular weight resin (A1) and the low molecular weight resin (A2).

Crosslinking agent ratio: The number of equivalents of the glycidyl group of the compounded crosslinking agent to the total of 1 equivalent of the carboxyl group of the high molecular weight resin (A1) and the low molecular weight resin (A2). When the low molecular weight resin (A2) does not have a carboxyl group, the amount is based on the carboxyl group of the high molecular weight resin (A1).

Insolubles: The weight percentage of insolubles after 24 hours of Soxhlet extraction using tetrahydrofuran. Tg: the glass transition temperature of the toner particles measured using DSC.

(Explanation of Results Obtained in Tables 3 to 5) In all Examples, a high molecular weight resin and a low molecular weight resin were used in combination, and a partial crosslinking was carried out in the particles using a crosslinking agent. High-molecular-weight resin and low-molecular-weight resin used in combination but not cross-linked, those with and without cross-linking using only high-molecular-weight resin, those with and without cross-linking using only low-molecular-weight resin In comparison with none, the fixing start temperature was low, the hot offset resistance was high, and excellent fixing characteristics were observed. Especially,
As a crosslinking agent, “TETRAD-X” (N, N, N ′,
When N′-tetraglycidyl-m-xylenediamine) and N, N-diglycidylbenzylamine were used, the effect was remarkable.

In all the examples, the aqueous medium dispersion of the toner particles after the crosslinking reaction had excellent dispersibility.

The present invention includes the following embodiments. 1. A resin having a weight-average molecular weight in the range of 50,000 to 400,000 having at least one crosslinkable functional group having a molecular average of more than 1;
After preparing a liquid medium dispersion of particles containing a colorant in a resin containing less than 000 resin and a crosslinking agent of the resin as a resin component, a part of the resin component is crosslinked and bound. A method for producing a powder toner in which a resin is formed, and the obtained partially crosslinked particles are separated from a liquid medium and dried.

[0220] 2. The binder resin is obtained by partially cross-linking a resin having a cross-linkable functional group exceeding at least one molecule average of 1 with a cross-linking agent until the content of an insoluble component in tetrahydrofuran becomes 0.5 to 70% by weight. The manufacturing method according to 1 above, wherein

3. The liquid medium dispersion of particles has a functional group (a1) that increases hydrophilicity by neutralization and at least one molecular average of 1
Having a weight average molecular weight of 50,000 to 40 which can be made water dispersible by neutralization having a crosslinkable functional group (a2) exceeding
A mixed resin (A) of a resin (A1) in the range of 0000, a resin (A2) having a weight average molecular weight of 5,000 or more and less than 50,000, and a crosslinking agent (B) of the mixed resin (A). ), A colorant (C), an organic solvent (D), and a neutralizing agent (E) sufficient to make the mixed resin (A) water-dispersible. Can be obtained by
The weight average molecular weight which can be water-dispersible by neutralization having at least one crosslinkable functional group exceeding 1 in molecular weight is 50,
As a resin component, a mixed resin of a resin in a range of 000 to 400,000, a resin having a weight average molecular weight of 5,000 or more and less than 50,000, and a crosslinking agent of the mixed resin,
3. The method according to 1 or 2 above, wherein the aqueous medium dispersion of particles in which a colorant is dispersed is contained.

4. The above resin (A2), wherein the resin (A2) has a functional group (a1) that increases hydrophilicity by neutralization and a crosslinkable functional group (a2) having an average molecular weight of at least 1 per molecule.
Manufacturing method.

5. In the resin (A1) and the resin (A2), the functional group (a1) that increases hydrophilicity by neutralization and the crosslinkable functional group (a2) having at least one molecular average of more than 1 are both carboxyl groups, and the resin (A1) 5. The method according to the above item 4, wherein the crosslinking agent (B) of the resin (A2) is a compound having at least one glycidyl group in one molecule on average.

6. The method according to the above item 5, wherein the compound having at least two or more glycidyl groups on average per molecule is glycidylamine.

7. A compound having at least two or more glycidyl groups on average per molecule is represented by the following general formula (1)
Or the glycidylamine having an average of 2 to 4 functional groups represented by (2) per molecule.

[0207]

Embedded image

(Provided that R ¹ and R ² in the formula represent an aromatic or alicyclic ring having or without a substituent, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms; and R ³ represents an alkyl group having 1 to 4 carbon atoms.)

[0209] 8. The above-mentioned 5, 6 wherein the crosslinking agent (B) is used in an amount within the range of 0.001 to 0.5 equivalent as glycidyl group per 1 equivalent of the total carboxyl groups of the resin (A1) and the resin (A2). Or the manufacturing method of 7.

[0210] 9. Resin having carboxyl group (A1)
And the resin (A2) having a carboxyl group are both 1
(5) The above vinyl copolymer having an acid value based on a carboxyl group in the range of 0 to 150 mg (KOH) / g.
Manufacturing method.

10. The resin is selected and combined such that the difference in weight average molecular weight between the high molecular weight resin (A1) and the low molecular weight resin (A2) is 10,000 or more. , 6, 7, 8, or 9.

[0212]

According to the present invention, in the state of the particle dispersion, the high molecular weight resin and the low molecular weight resin in the dispersed particles are crosslinked with a crosslinking agent to obtain a powder toner. It was possible to improve the hot offset resistance while maintaining the low-temperature fixability, which could not be solved by any of the methods of resin mixing, crosslinking using only a high molecular weight resin, and crosslinking using only a low molecular weight resin. It has a particularly remarkable effect that it can be done.

Claims (9)

[Claims] (1) a weight average molecular weight having a crosslinkable functional group exceeding at least one molecule average of 1 is 50,000 to 40;
And a weight average molecular weight of 5,000.
After preparing a liquid medium dispersion of particles containing a colorant therein, using a resin of not less than 00 and less than 50,000 and a crosslinking agent of the resin as a resin component, a part of the resin component is crosslinked. A method for producing a powdery toner, wherein a binder resin is obtained as a binder resin, and the obtained partially crosslinked particles are separated from a liquid medium and dried. 2. A binder resin comprising a resin having a crosslinkable functional group exceeding at least one molecule average of 1 with a crosslinking agent until the content of an insoluble component in tetrahydrofuran becomes 0.5 to 70% by weight. 2. The method according to claim 1, wherein 3. A dispersion of particles in a liquid medium can be made water-dispersible by neutralization having a functional group (a1) which increases hydrophilicity by neutralization and a crosslinkable functional group (a2) having an average molecular weight of at least 1 per molecule. Weight average molecular weight of 50,000 to 400,
000, a mixed resin (A) of a resin (A2) having a weight average molecular weight of 5,000 or more and less than 50,000, and a crosslinking agent (B) for the mixed resin (A)
A mixture containing a colorant (C), an organic solvent (D), and a neutralizing agent (E) sufficient to make the mixed resin (A) water-dispersible is subjected to phase inversion emulsification in an aqueous medium. Has a weight average molecular weight of 50,000 which can be made water-dispersible by neutralization having at least one crosslinkable functional group having an average molecular weight of more than 1.
A mixed resin of a resin having a weight average molecular weight of 5,000 or more and less than 50,000, and a crosslinking agent of the mixed resin as a resin component, and a colorant dispersed therein. 3. The method according to claim 1, which is an aqueous dispersion of the particles obtained. 4. The resin (A2) has a functional group (a1) which increases hydrophilicity by neutralization and a crosslinkable functional group (a2) having an average molecular weight of at least one.
Manufacturing method. 5. A resin (A1) and a functional group (a1) which increases hydrophilicity by neutralization of the resin (A2) and a crosslinkable functional group (a2) exceeding at least one molecule average of 1 are both carboxyl groups, 5. The method according to claim 4, wherein the crosslinking agent (B) of the resin (A1) and the resin (A2) is a compound having at least two or more glycidyl groups on average per molecule. 6. The method according to claim 5, wherein the compound having at least two or more glycidyl groups on an average of one molecule is glycidylamine. 7. A compound having at least two or more glycidyl groups on average per molecule has a glycidylamine having an average of 2 to 4 functional groups represented by the following general formula (1) or (2) per molecule. The manufacturing method according to claim 5, wherein Embedded image (However, R ¹ and R ² in the formula represent an aromatic or alicyclic ring having or not having a substituent, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, and R ³ represents It represents an alkyl group having 1 to 4 carbon atoms.) 8. Use of the crosslinking agent (B) in an amount within the range of 0.001 to 0.5 equivalent as glycidyl group per 1 equivalent of the total of carboxyl groups of the resin (A1) and the resin (A2). The method according to claim 5, 6, or 7. 9. The resin (A1) having a carboxyl group and the resin (A2) having a carboxyl group are both 10
6. A vinyl copolymer having an acid value based on a carboxyl group in the range of from 150 to 150 mg (KOH) / g.
Manufacturing method.