JPH0798517A - Binder resin manufacturing method and electrophotographic toner - Google Patents

Abstract

(57) [Summary] [Structure] (a) A mixture of two raw material monomers of a polymerization system each having an independent reaction path in one reaction vessel, and (b)
A compound capable of reacting with any of the two raw material monomers of the polymerization system and (c) a carboxylic acid having a valence of 3 or more or a derivative thereof are mixed in advance, and the two polymerization reactions are carried out in parallel in the same reaction vessel. A method for producing a binder resin,
Also, an electrophotographic toner containing a binder resin obtained by the production method. According to the present invention, the charge amount and the image quality are excellent in environmental stability, the pulverizability and the transparency are good, and moreover, in the heat roller fixing method, fixing can be performed at a low temperature without using the offset preventing liquid. A binder resin can be manufactured. Further, by using such a binder resin, it is possible to obtain an electrophotographic toner and a developer having excellent performance.

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 binder resin having good charge quantity and environmental stability in image quality, and a toner for electrophotography.

[0002]

2. Description of the Related Art Conventional electrophotographic methods include US Pat. Nos. 2,297,691 and 235780.
As described in, for example, No. 9, the photoconductive insulating layer is uniformly charged, and then the layer is exposed to light to dissipate the charge on the exposed portion to form an electrical latent image. After being formed, and further visualized by adhering a fine powder having a colored charge called a toner to the latent image (developing step), after transferring the obtained visible image to a transfer material such as transfer paper (Transfer step), permanent fixing by heating, pressure or other suitable fixing method (fixing step). Therefore, the toner must have the functions required not only in the developing process but also in the transferring process and the fixing process.

Generally, toner is subjected to a mechanical frictional force due to a shearing force and an impact force received during mechanical operation in a developing device,
It deteriorates while copying several thousand to tens of thousands. Such deterioration of the toner can be prevented by using a tough resin having a large molecular weight capable of withstanding mechanical frictional force. However, such a resin generally has a high softening point and is a non-contact fixing type oven. Fixing and radiant fixing using infrared rays do not sufficiently fix due to poor thermal efficiency. In addition, even in the heat roller fixing method which is widely used due to its good thermal efficiency in the contact fixing method, it is necessary to raise the temperature of the heat roller in order to sufficiently fix the fixing roller. In addition to causing harmful effects such as increase in energy, when such a resin is used, the pulverizability is poor, so that the production efficiency is significantly reduced when producing a toner. Therefore, a binder resin having a too high degree of polymerization and a softening point cannot be used.

On the other hand, the heat roller fixing system has a remarkably good thermal efficiency because the surface of the heating roller and the toner image surface of the sheet to be fixed are in pressure contact with each other, and is widely used from low speed to high speed. When the image surfaces come into contact with each other, the toner adheres to the surface of the heating roller and is transferred to the subsequent transfer paper or the like, which is a drawback that a so-called offset phenomenon easily occurs. In order to prevent this phenomenon, the surface of the heating roller is processed with a material having excellent releasing property such as a fluorine-based resin, or a releasing agent such as silicone oil is applied to the surface of the heating roller. However, the method of applying silicone oil or the like is not preferable because not only the fixing device becomes large and the cost becomes high, but also the device becomes complicated, which may cause troubles.

Also, a method of improving the offset phenomenon by making the resin asymmetric and cross-linked (Japanese Patent Publication No. 57-493).
Nos. 50-44836 and 57-37353), but the fixing point has not been improved.

Generally, since the minimum fixing temperature is between the low temperature offset and the high temperature offset, the usable temperature range is
Between the minimum fixing temperature and the high temperature offset, the minimum fixing temperature can be lowered as much as possible, and the high temperature offset generation temperature can be increased as much as possible to reduce the fixing temperature in use and widen the usable temperature range, thereby saving energy. High-speed fixing and paper curl can be prevented. Therefore, there is always a demand for resins and toners having good fixability and offset resistance.

In order to achieve such a requirement, when a styrene-based binder resin is used, a method of adding paraffin wax, low molecular weight polyolefin or the like as an offset preventing agent (Japanese Patent Application Laid-Open No. Sho 49-65232, Kaisho 5
No. 0-28840 and JP-A No. 50-81342) are known, but in this case, the effect cannot be obtained if the addition amount is small, and if it is too large, there is a problem that the deterioration of the developer is rapid. .

Polyester resins are inherently well-fixed and, as described in US Pat. No. 3,590,000,
It can be sufficiently fixed even in the non-contact fixing method, but it is difficult to use in the heat roller fixing method because the offset phenomenon easily occurs. Polyester resin with improved offset resistance using polycarboxylic acid (JP-A-50-4
4836, JP-A-57-37353, JP-A-57-
No. 109875) does not have sufficient offset resistance to be used or has not only sacrificed the low temperature fixing property originally possessed by the polyester resin, but also the resin itself or There is also a problem that the pulverizability is extremely poor even in the toner forming step.

To reduce the particle size of the toner in order to obtain high resolution in the electrophotographic system, there has been a problem of how to efficiently and inexpensively secure the small particle size toner.

When the polyester resin has an acid value and a hydroxyl value in order to improve the dispersion of the colorant, styrene / acrylic resin is used to maintain the charge amount after toner formation and the environmental stability of image quality. As compared with the case of using a resin of a type, there is a limitation in the compounding when forming a toner. Therefore, in order to solve the above problem, the following method is known in which a polyester resin and a styrene acrylic resin are mixed and used. For example, the following methods have been proposed.

A method of mixing a polyester resin and a styrene acrylic resin (JP-A-49-6931, JP-A-SHO-5).
4-114245, JP-A-57-70523, JP-A-2-161464); A method of chemically bonding a polyester resin and a styrene-acrylic resin (JP-A-56-116043); vinyl-based unsaturated polyester Method of copolymerizing monomers (JP-A-57-60339 and JP-A-63-2)
79265, JP-A-1-156759, JP-A-2-
No. 5073); A method of copolymerizing a vinyl monomer with a polyester resin having a (meth) acryloyl group (JP-A-59-59).
45453); a method of copolymerizing a reactive polyester and a vinyl monomer in the presence of a polyester resin (JP-A-2-2966).
No. 4); and a method of blocking a polyester resin and a vinyl resin with an ester bond (JP-A-2-881).

However, since the polyester resin and the styrene-acrylic resin are inherently poor in compatibility, when mechanically mixing, depending on the mixing ratio, background stain may occur in the image evaluation after toner formation, or reaction may occur. In the case of polymerizing a vinyl monomer with a polymerizable polyester, the composition ratio is limited in order to prevent gelation.

Furthermore, the present inventors have developed a technique in which a resin obtained by simultaneously advancing addition polymerization and polycondensation in the same reaction vessel is used as a binder for toner (JP-A-4-142301). A binder having a sea-island structure in which a styrene acrylic resin is dispersed is disclosed as the binder for the toner, but the dispersed particle size is larger than 2 μm. Therefore, although this method can lower the fixing temperature, it is not sufficiently satisfactory in terms of improving the life of the toner. Therefore, there has been a demand for a binder resin for electrophotography which is excellent in low-temperature fixability and anti-offset property, has good charge stability and environmental stability of image quality, and is also excellent in durability of a developer.

Accordingly, one object of the present invention is to provide a method for producing a binder resin having a good amount of charge and environmental stability of image quality. Another object of the present invention is to provide an electrophotographic toner using such a binder resin.

[0015]

Under the above circumstances, the present inventors have conducted diligent research and as a result, when premixing two raw material monomer mixtures of the polymerization system and carrying out the two polymerization reactions in parallel. In addition, when a compound capable of reacting with any of the two raw material monomers of the two polymerization systems and a carboxylic acid having a valence of 3 or more are used as a crosslinking agent, a binder resin having good charge stability and environmental stability in image quality is produced. Find out what you can do,
The present invention has been completed.

That is, the gist of the present invention is (1)
(A) a mixture of two polymerization system raw material monomers each having an independent reaction path in one reaction vessel, (b) a compound capable of reacting with any of the two polymerization system raw material monomers, and (c) a trivalent A method for producing a binder resin, characterized in that the above carboxylic acids or derivatives thereof are mixed in advance and the two polymerization reactions are carried out in parallel in the same reaction vessel, (2)
The production method according to (1) above, wherein the binder resin is a condensation polymerization resin and an addition polymerization resin, and (3) the weight ratio of the condensation polymerization resin to the addition polymerization resin is 50/50 to 95/5. (4) The production method according to (2) above, wherein (4) polycondensation is to obtain polyester, polyester-polyamide or polyamide, and addition polymerization is to obtain vinyl resin by radical polymerization. (5) The average number molecular weight of the addition polymerization resin is 1
The production method according to any one of the above (2) to (4), which is 1,000 or less, (6) A compound capable of reacting with any of the two raw material monomers of the polymerization system is represented by the general formula (I) or (II).

[0017]

[Chemical 6]

[In the formula, R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group, an alkoxy group, an aryl group or a vinyl group or a halogen atom. As shown, these may together form a ring. A and B are the same or different and each represents an alkylene group represented by the general formula (III) or a general formula (IV).
A phenylene group represented by

[0019]

[Chemical 7]

(R ⁴ , R ⁵ and R ⁶ are the same or different and represent a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group, an alkoxy group, an aryl group or a vinyl group or a halogen atom, May together form a ring, m represents 0 to 5, n represents an integer of 0 to 2), X and Y are the same or different, and -COOR
⁷ or —OR ⁸ (R ⁷ and R ⁸ represent a hydrogen atom or a lower alkyl group which may have a substituent)], or (7) )
The production method according to (6) above, wherein the compound capable of reacting with any of the two raw material monomers of the polymerization system is one or more selected from the group consisting of compounds (1) to (36),

[0021]

[Chemical 8]

[0022]

[Chemical 9]

[0023]

[Chemical 10]

(8) The production method according to any one of (1) to (7) above, wherein the trivalent or higher carboxylic acid is trimellitic acid, (9) a compound capable of reacting with any of the two raw material monomers of the polymerization system. Is added in an amount of 0.5 to 10% by weight with respect to the polycondensation raw material monomer.
(8) The production method according to any one of (1) to (9), wherein the addition amount of the trivalent or higher carboxylic acid is 0.2 to 30% by weight with respect to the raw material monomer of the polycondensation system. ) Any one of the above-mentioned (1) to (1), wherein the binder resin obtained has an acid value of 20 KOHmg / g or less.
0) The manufacturing method according to any one of the above items, (12) The softening point of the obtained binder resin is 70 to 150 ° C., and the glass transition temperature is 50 to 80 ° C., which is the above (1) to (11). Manufacturing method, and (13) above (1) to (12)
The present invention relates to an electrophotographic toner containing a binder resin obtained by any one of the methods.

In the present invention, the two polymerization systems are those in which the polymerization reactions are carried out by independent reaction paths. Of the two polymerization systems, one is preferably a condensation polymerization type and the other is an addition polymerization type.

Typical polycondensation type polymerization systems are those which obtain polyesters, polyester-polyamides and polyamides by polycondensation, and addition polymerization type polymerization systems are typically those which obtain vinyl resins by radical polymerization. .

Among these, the polyester can be obtained by using alcohol and carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, or the like as raw material monomers.

Here, examples of the dihydric alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene.
(3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.
0) -Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene
(6) alkylene oxide adduct of bisphenol A such as -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, poly Examples thereof include tetramethylene glycol, bisphenol A, hydrogenated bisphenol A and the like.

Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, and 1,4.
-Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,
4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like can be mentioned.

Of these alcohol components, alkylene oxide adducts of bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,3-
Propylene glycol and neopentyl glycol are used. In the present invention, these dihydric alcohol monomers and trihydric or higher polyhydric alcohol monomers can be used alone or in combination.

Examples of the acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n
-Octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, and anhydrides or lower alkyl esters of these acids. Preferably, maleic acid, fumaric acid, terephthalic acid and alkenylsuccinic acid are used.

Of the raw material monomers forming the amide component in the polyester polyamide or polyamide obtained by polycondensation, the raw material monomers include, for example, ethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, iminobispropylamine, phenylene. Polyamines such as diamine, xylylenediamine and triethylenetetramine, aminocarboxylic acids such as 6-aminocaproic acid and ε-caprolactam,
Examples thereof include amino alcohols such as propanolamine. Hexamethylenediamine and ε-caprolactam are preferably used.

Typical monomers used to form the vinyl resin obtained by addition polymerization include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene. , Styrene or styrene derivatives such as p-ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene; vinyl chloride, odor, etc. Vinyl esters such as vinyl chloride, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate and vinyl caproate; for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate. , Isobutyl acrylate, te acrylate t-butyl, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, 2-hydroxy acrylate Ethyl, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-
Methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n methacrylate -Octyl, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, methacrylic acid 2
-Ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate,
Ethylenic esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride;
Examples thereof include N-vinyl compounds such as vinylpyrrole and N-vinylpyrrolidone. In the present invention, preferably α
-Methylstyrene, propylene, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate are used.

A polymerization initiator is used in the production of the vinyl resin, and examples of such a polymerization initiator include:
2,2'-azobis (2,4-dimethylvaleronitrile), 2,
2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, other azo compounds or diazo Type polymerization initiator or peroxide type polymerization initiator such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxy carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, dicumyl peroxide Is mentioned.

Two or more kinds of polymerization initiators may be mixed and used for the purpose of controlling the molecular weight and the molecular weight distribution of the polymer, the reaction time or the like. The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerized monomer.

In the present invention, if the molecular weight of the resin produced in one of the reaction paths is lowered, the pulverizability of the binder resin can be improved. In particular, when the number average molecular weight of the addition-polymerized resin portion is 11,000 or less, it is effective in improving the pulverizability of the binder resin, which is preferable. In order to reduce the number average molecular weight to 11,000 or less, a polymerization initiator may be frequently used or a chain transfer agent may be used.

In the present invention, the compound capable of reacting with any of the two raw material monomers of the polymerization system and the carboxylic acid having a valence of 3 or more or its derivative are used as a crosslinking agent. Examples of the compound capable of reacting with any of the raw material monomers of the system include those represented by the following general formulas (I) and (II).

[0038]

[Chemical 11]

[In the formula, R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group, an alkoxy group, an aryl group or a vinyl group or a halogen atom. As shown, these may together form a ring. A and B are the same or different and each represents an alkylene group represented by the general formula (III) or a general formula (IV).
A phenylene group represented by

[0040]

[Chemical 12]

(R ⁴ , R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group, an aryl group or a vinyl group or a halogen atom. May together form a ring. M represents a number from 0 to 5 and n represents a number from 0 to 2.)
And X and Y are the same or different and each represents -COOR ⁷ or -OR ⁸ (R ⁷ and R ⁸ represent a hydrogen atom or a lower alkyl group which may have a substituent).

Here, these compounds are required to be able to react with both of the two raw material monomers of the polymerization system, but when there are two or more kinds of the raw material monomers of the one polymerization system, at least one of them is used. It only needs to be able to react with one.

Among the groups represented by R ^{1 to} R ⁶ in the general formulas (I) and (II), the alkyl group is a straight or branched chain having 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms. Are preferred, for example, methyl group, ethyl group, n-propyl group, i-
Examples thereof include a propyl group, an n-butyl group and a tert-butyl group. These alkyl groups may be substituted with a phenyl group, a naphthyl group, a hydroxyl group or the like. Examples of the alkoxy group include methoxy group, ethoxy group, n-
Examples thereof include a propoxy group, an i-propoxy group, a t-butoxy group and the like, and these groups may be substituted with a hydroxyl group, a carboxyl group or the like. Examples of the aryl group include a phenyl group, a naphthyl group and a benzyl group, and these groups may be substituted with a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxyl group, a hydroxyl group or the like. Moreover, the vinyl group may be substituted with a hydroxyl group, a phenyl group, an alkyl group, an alkoxy group, a carboxyl group, or the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a chlorine atom and a bromine atom are particularly preferable. Further, the lower alkyl group represented by R ⁷ and R ⁸ has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group and the like, and these groups are substituted with a hydroxyl group or the like. Good.

Typical compounds represented by the general formulas (I) and (II) are the following compounds (1) to (3).
There is 6).

[0045]

[Chemical 13]

[0046]

[Chemical 14]

[0047]

[Chemical 15]

Further, the lower alkyl ester of the above-mentioned ethylenic monocarboxylic acid and the anhydride of the above-mentioned ethylenic dicarboxylic acid can be mentioned. On the other hand, examples of the trivalent or higher carboxylic acid or its derivative used as the crosslinking agent in the present invention include 1,2,4-benzenetricarboxylic acid, 2,5,
7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5
-Hexanetricarboxylic acid, 1,3-dicarboxyl-2
-Methyl-2-methylenecarboxypropane, 1,2,4-
Examples thereof include cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, their acid anhydrides and lower alkyl esters. Of these, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof, is preferable because it is inexpensive and the reaction control is easy.

Of these cross-linking agents, compounds capable of reacting with any of the two raw material monomers of the polymerization system are effective for reducing the dispersed particle size of the resin after the reaction is completed. It is preferable to use 0.5 to 10% by weight, especially 0.5 to 5% by weight.

The trivalent or higher carboxylic acid or its derivative is effective in controlling the degree of polymerization of the resin, and is 0.2 to 30% by weight, particularly 0.5 to 30% by weight based on the polycondensation raw material monomer.
It is preferred to use wt%.

In the present invention, when these cross-linking agents are used within the above range, the obtained binder resin becomes completely uniform and has no sea-island structure, or has a sea-island structure. The average particle size of the resin dispersed phase corresponding to the island structure is as small as 2 μm or less.

If the amount of these crosslinking agents used is too large, gelation occurs during the polymerization reaction, and if the amount used is too small, part of the toner does not completely adhere to the paper during heat roll fixing. It is not preferable because it is difficult to prevent the offset phenomenon of adhering to the roller surface and transferring to the next paper.

In particular, when the amount of the compound capable of reacting with either of the two raw materials of the polymerization system is small, the two polymerization systems become incompatible with each other to form a resin having a large sea-island structure, and the colorant is dispersed. It is not preferable because it deteriorates and causes scumming and uneven printing.

In the parallel reaction, the progress and completion of the two polymerization reactions do not have to be simultaneous in time, and the reaction temperature and time are appropriately selected according to the respective reaction mechanisms to proceed the reaction. , Just complete it.

In the polymerization reaction, for example, a mixture of a raw material monomer of vinyl resin, a crosslinking agent and a polymerization initiator is added to a mixture of raw material monomers of polyester, polyester-polyamide or polyamide under a temperature condition suitable for addition polymerization reaction. A step of dropping to carry out a partial polycondensation reaction in parallel with the addition polymerization reaction, a step of maintaining the temperature of the obtained mixture under the above conditions to complete only the addition polymerization reaction, and then raising the reaction temperature. And a step of increasing the degree of polymerization of the polycondensation reaction.

Here, the temperature condition suitable for the addition polymerization reaction depends on the kind of the polymerization initiator used, but it is 50 to 1
It is usually carried out in the temperature range of 80 ° C. The optimum temperature range for increasing the polymerization degree of the polycondensation reaction is usually 190 to
270 ° C. As described above, a binder resin in which two kinds of resins are effectively mixed and dispersed can be obtained by a method of allowing two independent reactions to proceed in parallel in a reaction vessel.

In the present invention, the weight ratio of the condensation polymerization resin and the addition polymerization resin or the condensation polymerization resin monomer to the addition polymerization resin monomer is 50/50 to 95 / in order to disperse the addition polymerization resin. 5, especially from 70/30
It is preferably 90/10.

The binder resin thus obtained has a softening point of 70 to 150 ° C., particularly preferably 95 to 150 ° C.,
Glass transition temperature is 50 to 80 ° C, particularly preferably 52 to
70 ° C, acid value less than 20KOHmg / g, especially 15KO
It is preferable to set it to Hmg / g or less. The softening point, the glass transition temperature and the acid value of the binder resin can be easily adjusted within these ranges by adjusting the polymerization initiator and the amount of catalyst in the raw material monomer mixture or selecting the reaction conditions.

To produce a toner using the binder resin obtained by the present invention, for example, the binder resin, a colorant, and if necessary, a charge control agent, a magnetic material and the like are added.

As the colorant used in the present invention, various carbon blacks produced by the thermal black method, acetylene black method, channel black method, lamp black method and the like, and grafts obtained by coating the surface of carbon black with a resin. Carbon Black, Nigrosine Dye, Phthalocyanine Blue, Permanent Brown FG,
Brilliant First Scarlet, Pigment Green B, Rhodamine-B Base, Solvent Red 49,
Solvent Red 146, Solvent Blue 35 and the like and mixtures thereof can be mentioned, and it is usually preferable to use about 1 to 15 parts by weight per 100 parts by weight of the binder resin.

As the charge control agent used as necessary, either positive or negative charge control agents can be used. The specific examples of the positive charge control agent are not particularly limited, and examples thereof include a nigrosine dye "Nigrosine Base E".
"X", "Oil Black BS", "Oil Black S"
O "," Bontron N-01 "," Bontron N-0 "
7 "," Bontron N-11 "(above, manufactured by Orient Chemical Co., Ltd.); triphenylmethane dye containing a tertiary amine as a side chain, quaternary ammonium salt compound, for example," Bontron P-51 "(Orient Chem. ), Cetyl trimethyl ammonium bromide, "COPY CHARGE PX
VP435 "(manufactured by Hoechst) and the like; polyamine resins such as" AFP-B "(manufactured by Orient Chemical Co.), imidazole derivatives such as" PLZ-2001 "and" PLZ-80 ".
01 ”(above, manufactured by Shikoku Kasei) and the like. Preferably, Bontron N-07 can be used.

Specific examples of the negative charge control agent include:
Without being particularly limited, for example, metal-containing azo dyes such as “Varifast Black 3804” and “Bontron S
-31 "(above, manufactured by Orient Chemical Co., Ltd.)," T-77 "
(Manufactured by Hodogaya Chemical Co., Ltd.), "Bontron S-32", "Bontron S-34", "Bontron S-36" (above,
Orient Chemical Co., Ltd.), "Aizen Spyron Black T
RH "(manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dye, metal complex of alkyl derivative of salicylic acid, for example," Bontron E-81 "," Bontron E-82 ",
Examples thereof include “Bontron E-84” and “Bontron E-85” (all manufactured by Orient Chemical Co., Ltd.); quaternary ammonium salts such as “COPY CHARGE NX VP434” (manufactured by Hoechst) and nitroimidazole derivatives. Preferably, Bontron S-34, T-77, and Eisenspiron Black TRH can be used. The above charge control agent is 0.1 to 8.0% by weight, preferably 0.1% to the binder resin.
Use 2 to 5.0% by weight.

Further, it is preferable to use wax such as polyolefin as the offset preventing agent, and the binder resin 1
It is preferable to use 1 to 5 parts by weight with respect to 00 parts by weight.
Here, examples of the polyolefin include polyethylene, polypropylene and the like, and those having a relatively low molecular weight, particularly those having a molecular weight of 3,000 to 1,500 by a vapor permeation method.
0 is preferable. The softening point by the ring and ball method is 70
˜150 ° C., especially 120 to 150 ° C. is preferable.

In conventional toners, it was difficult to blend these waxes because of poor compatibility,
In the present invention, they can be easily blended, and by blending them, the low temperature fixing property becomes more excellent.

Further, when the toner is manufactured, a property improving agent such as a fluidity improving agent such as hydrophobic silica may be added, but when the binder resin of the present invention is used, these properties improving agents may be added. It is not necessary to add the property improving agent, and even when it is added, the addition amount may be small.

The binder resin obtained by the present invention, the colorant, and optionally the property improving agent are uniformly dispersed, and then melt-kneaded, cooled, pulverized and classified by a known method to give an average particle diameter of 5 to 5. 15 μm toner can be obtained. The toner may be a non-magnetic one-component developer, or by mixing a magnetic powder, that is, an iron oxide-based carrier, a spherical iron oxide-based carrier or a ferrite-based carrier as it is, or by mixing it with a resin or the like. , A dry two-component developer can be used.

To produce a magnetic toner, magnetic particles may be added to the binder resin obtained by the present invention. As the magnetic particles, for example, ferrite, magnetite and other iron, cobalt, nickel and other ferromagnets or alloys showing ferromagnetism, compounds containing these elements, or containing no ferromagnetism elements, an appropriate heat treatment is applied. Examples thereof include alloys that exhibit ferromagnetism, such as manganese-copper-aluminum, manganese-copper-tin, and other types of alloys called Heusler alloys containing manganese and copper, or chromium dioxide. A compound containing a ferromagnetic element is preferably used, and magnetite is particularly preferably used. These magnetic materials are uniformly dispersed in the core material in the form of fine powder having an average particle size of 0.1 to 1 μm. And its content is 20 per 100 parts by weight of binder resin.
˜70 parts by weight, preferably 30 to 70 parts by weight.

[0068]

EXAMPLES Next, the present invention will be further described with reference to examples, but the present invention is not limited to these examples.

The acid value and glass transition temperature of the obtained binder resin were measured by the following methods. [Acid Value] The acid value was measured according to the method described in JIS K0070. [Glass Transition Temperature (Tg)] Using a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.), the temperature was raised to 100 ° C., allowed to stand for 3 minutes at that temperature, and then cooled to room temperature at a temperature lowering rate of 10 ° C./min. When the sample was measured at a heating rate of 10 ° C / min., The intersection of the extension line of the baseline below the glass transition temperature and the tangent line showing the maximum slope from the rising portion of the peak to the peak apex The temperature was taken as the glass transition temperature (Tg).

Example 1 410 g of styrene (3.
94 mol), 2-ethylhexyl acrylate 90 g
(0.49 mol), 30 g of acrylic acid (0.
42 mol) and 20 g (0.12 mol) of azobisisobutyronitrile as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 780 g (2.23 mol), isododecenyl succinic anhydride 76 g (0.28 mol), terephthalic acid 180 g (1.09 mol), crosslinking agent As 1,
2,4-benzenetricarboxylic acid 30 g (0.16 mol)
And 2 g (8.0 mmol) of dibutyltin oxide were placed in a 3 liter 4-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube, and 135 ° C. under a nitrogen atmosphere in a mantle heater. While stirring at the above temperature, the vinyl resin monomer, the cross-linking agent and the polymerization initiator were added dropwise from the above dropping funnel over 4 hours. 1
Aging was carried out for 5 hours while maintaining the temperature at 35 ° C, and the temperature was raised to 230 ° C for reaction. The degree of polymerization was traced from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 120 ° C.

The glass transition temperature (Tg) of the obtained resin was 60 ° C. with one peak. Further, a resin having a diameter of 0.2 mm was cut with a microtome to a thickness of 150 nm, and the obtained thin piece was observed with a transmission scanning electron microscope (“JEM-2000” manufactured by JEOL (JEOL Ltd.)). However, it was a completely uniform resin having no sea-island structure.
The acid value was 8.0 KOHmg / g. The obtained resin is referred to as Binder Resin A.

Example 2 Styrene 400 g (3.
85 mol), 77 g of 2-ethylhexyl acrylate
(0.42 mol), fumaric acid 39.1 g as a crosslinking agent
(0.34 mol), 15 g (0.06 mol) of a dimer of α-methylstyrene as a chain transfer agent, and 25 g (0.09 mol) of dicumyl peroxide as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2
-Bis (4-hydroxyphenyl) propane 756 g
(2.16 mol), hexamethylenediamine 40.3 g
(0.34mol), 210g of isophthalic acid (1.26mo
l), 63 g (0.34 mol) of 1,2,4-benzenetricarboxylic acid as a cross-linking agent and 3 g of dibutyltin oxide (1
2.0 mmol), 3 liters of 4 equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube.
Place in a neck flask. The following operations were performed under the same polymerization conditions as in Example 1.

The resin thus obtained was evaluated in the same manner as in Example 1. As a result, the glass transition temperature of the resin was 6 with one peak.
It showed 3 ° C. The average dispersed particle diameter of vinyl resin is 0.5μ
m was highly dispersed. Acid value is 5.5 KOHmg / g
Met. The obtained resin is referred to as Binder Resin B.

Example 3 350 g of styrene (3.
37 mol, butyl methacrylate 150 g (1.29 mo)
l), 55 g (0.38 mol) of methacrylic acid as a cross-linking agent, and 25 g of dicumyl peroxide as a polymerization initiator.
(0.09 mol) is added to the dropping funnel. Neopentyl glycol 328.8 g (3.15 mol), isophthalic acid 3
28.8 g (1.97 mol), 1,2,4-as a crosslinking agent
104 g (0.55 mol) of benzenetricarboxylic acid and 3 g (12.0 mmol) of dibutyltin oxide were placed in a 3 liter four-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube. The following operations were performed under the same polymerization conditions as in Example 1.

The resin thus obtained was evaluated in the same manner as in Example 1. As a result, the glass transition temperature of the resin was 6 with one peak.
It showed 3 ° C. It was uniform with no sea-island structure. The acid value was 9.0 KOHmg / g. The obtained resin is referred to as a binder resin C.

Comparative Example 1 850 g of xylene was placed in a 2-liter glass four-necked flask equipped with a thermometer, a stainless stir bar, a flow-down condenser, and a nitrogen introducing tube, and the temperature was raised to 135 ° C. after purging with nitrogen. 700 g (6.73 mol) of styrene, 300 g (2.58 mol) of butyl methacrylate, and 50 g (0.19 mol) of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel and added dropwise over 4 hours. Aged for hours. Then, the temperature was raised to 200 ° C., xylene was distilled off under reduced pressure, the mixture was extracted into a vat, cooled, and then pulverized. The softening point of the obtained resin according to ASTM E28-67 was 105 ° C, and the glass transition temperature was 64 ° C.

Polyoxypropylene (2.2) -2,2
650 g of bis (4-hydroxyphenyl) propane
(1.86 mol), 300 g of isophthalic acid (1.81 mol)
And 2 g (8.0 mmol) of dibutyltin oxide were placed in a 5 liter 4-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube.
Homogeneous polycondensation was carried out at 30 ° C. The acid value of the obtained resin is 1
It was 2.6 KOH mg / g. 400 g of the vinyl resin obtained above and 600 g of polyester resin were kneaded at 100 ° C. by a biaxial extrusion type kneader.

The resin thus obtained was evaluated in the same manner as in Example 1. As a result, the softening point of the resin showed 121 ° C., and the glass transition temperatures showed two peaks at 60 ° C. and 64 ° C. The vinyl resin had an average dispersed particle diameter of 12.8 μm, and was a resin having a large sea-island structure. The acid value is 9.8KOH
It was mg / g. The obtained resin is referred to as Binder Resin D.

Comparative Example 2 410 g of styrene (3.
94 mol), 2-ethylhexyl acrylate 90 g
(0.49 mol) and 20 g (0.12 mol) of azobisisobutyronitrile as a polymerization initiator are placed in a dropping funnel. 780 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (2.2
3 mol), isododecenyl succinic anhydride 76 g (0.28
mol), terephthalic acid 220 g (1.33 mol), and 1,2,4-benzenetricarboxylic acid 30 g (0.
16 mol) and 2 g of dibutyltin oxide (8.0 mmol)
Was placed in a 3 liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser and a nitrogen introducing tube, and was heated to 135 ° C. in a nitrogen atmosphere in a mantle heater.
While stirring at the above temperature, the vinyl resin monomer, the cross-linking agent and the polymerization initiator were added dropwise from the above dropping funnel over 4 hours. While maintaining the temperature at 135 ° C, the mixture was aged for 5 hours, heated to 230 ° C and reacted. The degree of polymerization is ASTM E28-
The softening point according to 67 is followed, and the softening point is 120
The reaction was terminated when it reached ° C.

The resin thus obtained was evaluated in the same manner as in Example 1. As a result, the glass transition temperature of the resin showed one peak at 63 ° C. The average dispersed particle diameter of vinyl resin is 7.0μ
m was a resin having a large sea-island structure. The acid value was 8.0 KOHmg / g. The obtained resin is referred to as Binder Resin E.

Comparative Example 3 400 g of styrene (3.
85 mol), 77 g of 2-ethylhexyl acrylate
(0.42 mol), 15 g (0.06 mol) of a dimer of α-methylstyrene as a chain transfer agent, and 25 g (0.09 mol) of dicumyl peroxide as a polymerization initiator are placed in a dropping funnel. Polyoxypropylene (2.2) -2,2
-Bis (4-hydroxyphenyl) propane 396g
(1.13 mol), 166 g of isophthalic acid (1.00 mo
l), 14.8 g (0.16 mol) of glycerin as a crosslinking agent
And 2 g (8.0 mmol) of dibutyltin oxide were placed in a 3 liter 4-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen inlet tube.
The following operations were performed under the same polymerization conditions as in Example 1. The degree of polymerization was traced from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 120 ° C.

The resin thus obtained was evaluated in the same manner as in Example 1. As a result, although the glass transition temperature of the resin showed one peak at 64 ° C., the average dispersed particle diameter of the vinyl resin was 7.9 μm, and a large sea-island structure was observed. The acid value was 9.7 KOHmg / g. The obtained resin is referred to as a binder resin F.

Comparative Example 4 810 g of styrene (7.
79 mol), 359 g of 2-ethylhexyl acrylate
(1.95 mol), 20 g (0.12 mol) of azobisisobutyronitrile as a polymerization initiator, and 10 g (0.09 mol) of fumaric acid as a crosslinking agent are put in a dropping funnel. 380 g (1.09 mol) of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 36 g (0.13 mol) of isododecenyl succinic anhydride, 130 g (0.78 mol) of terephthalic acid and dibutyltin. 1 g (4.0 mmol) of oxide was placed in a 3 liter 4-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser and a nitrogen introducing tube, and in a mantle heater,
While stirring at a temperature of 135 ° C. in a nitrogen atmosphere, the vinyl resin monomer, the cross-linking agent and the polymerization initiator were dropped from the dropping funnel over 4 hours. Keeping at 135 ℃ 5
Aging was carried out for an hour, and the temperature was raised to 230 ° C. for reaction. The degree of polymerization was traced from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 120 ° C.

The resin thus obtained was evaluated in the same manner as in Example 1. As a result, although the glass transition temperature of the resin showed one peak at 60 ° C., the average dispersed particle diameter of the polyester resin was 8.0 μm, and a large sea-island structure was observed. The acid value was 6.0 KOHmg / g. The obtained resin is referred to as a binder resin G.

Test Example 1 Materials having the compositions shown in Table 1 were premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, cooled, and then subjected to normal grinding.
An untreated toner having an average particle size of 11 μm was manufactured through a classification process.

[0086]

[Table 1]

The untreated toners 1 to 4 thus obtained were each mixed with 100 parts by weight of hydrophobic silica "H-2000".
Toners 1 to 4 were obtained by mixing and adhering 0.1 part by weight (manufactured by Wacker Chemical Co., Ltd.) using a Henschel mixer. Similarly, silica was attached to untreated toners 5 to 8 to make comparative toners 1 to 4, respectively.

39 parts by weight of each of the above toners and 1261 parts by weight of styrene-methylmethacrylate resin-coated ferrite powder (average particle size 100 μm) were mixed to prepare a developer, and a commercially available electrophotographic copying machine (photosensitive The body is toner 1, 2, and 3, comparative toners 1, 2, 3, and 4 are amorphous selenium, toner 4 is an organic photoconductor, and the rotation speed of the fixing roller is set to 255 mm / sec. The heat roller temperature was varied and the oil coating device was removed) to form an image, and the fixability, pulverizability, transparency, offset resistance and printing durability were evaluated by the following methods.

(1) Toner fixability: The toner fixability was evaluated by the minimum fixing temperature. Here, the minimum fixing temperature is a reflection densitometer of Macbeth Inc. before and after rubbing 5 times on the image fixed through a fixing machine, placing a load of 500 g on a sand eraser having a bottom surface of 15 mm x 7.5 mm, and rubbing. The optical reflection density is measured according to the following, and it means the temperature of the fixing roller when the fixing rate exceeds 70% according to the following definition.

Fixing rate (%) = [(image density after rubbing)
/ (Image density before rubbing)] × 100

The fixing roller temperature was controlled between 100 and 240 ° C. to evaluate the fixing property. The results are shown in Table 2.

(2) Resin pulverizability: Resin which has undergone the usual pulverization process is sieved and passed through 16 mesh, but 20
A resin powder that does not pass through the mesh is obtained. 30.00 g of the resin powder classified in this way was precisely weighed and the coffee mill (P
After crushing for 15 seconds with HILIPS company type, HR-2170 type), it is passed through a 32 mesh sieve, and the weight (A) g of the resin that does not pass is precisely weighed. From this weight, the residual rate is calculated by the following formula, and this operation is performed three times and averaged. The average residual rate is 0 to 15.0%, and 15.1 to 30.0% is ◯,
30.1 to 45.0% was evaluated as Δ, and 45.1 or more was evaluated as x. The results are shown in Table 2. Residual rate (%) = [A (g) /
Resin weight (30.00g) before grinding in coffee mill] x 100

(3) Transparency of resin: Immediately after completion of the reaction, the resin is placed in a disk-shaped mold having a thickness of 10 mm and a diameter of 60 mm and allowed to cool. It was taken out from the mold, a paper with 1 cm x 1 cm letters was placed under the resin plate, and it was seen through the resin from above. Characters with which the above-mentioned resin plates can be read even if three sheets are piled up are evaluated as ⊚, ones which can read up to two sheets are marked as ○, one that can be read only through one sheet is evaluated as △, and one that cannot be read at the first sheet is evaluated as ×. The results are shown in Table 2.

(4) Offset resistance: The offset resistance was evaluated by measuring the low temperature offset disappearance temperature and the high temperature offset generation temperature. That is, the temperature of the surface of the heat roller was raised in the range of 70 to 220 ° C. by 5 ° C., and a copy test was performed. At each temperature, the adhesion of the toner on the surface of the heat roller was visually evaluated. The results are shown in Table 2.

(5) Printing durability: The charge amount was measured by a blow-off type charge amount measuring device described below, that is, a specific charge measuring device equipped with a Faraday cage, a condenser and an electrometer. The measuring method is as follows. First, the developer prepared above is used for W (g) (0.15 to 0.20).
g) is put into a brass measuring cell equipped with a 500-mesh stainless steel mesh (which can be appropriately changed to a size that does not allow carrier particles to pass). Next, after suctioning for 5 seconds from the suction port, the air pressure is blown for 5 seconds at an air pressure of 0.6 kg / cm ² to remove only the toner from the cell.

At this time, the voltage of the electrometer 2 seconds after the start of the blow is V (volt). If the electric capacity of the condenser is C (μF), the specific charge of this toner is Q /
m is calculated by the following equation. Q / m (μC / g) = C × V / m

Here, m is the weight of the toner contained in the developer in W (g), where T (g) is the weight of the toner in the developer and D (g) is the weight of the developer. In that case, the toner density of the sample is expressed as T / D × 100 (%), and m is calculated by the following equation. m (g) = W × (T / D)

The developer was used in the copying machine and 100,000 continuous copies of each were made under normal environment (23 ° C., 50% R).
H), high temperature, high humidity (35 ° C, 85% RH)
The change in charge amount and the occurrence of background stain during the printing durability test were evaluated. The results are shown in Table 3.

[0099]

[Table 2]

[0100]

[Table 3]

From the results of Table 2, toners 1 to 4 of the present invention
Has a low minimum fixing temperature and low offset extinction temperature,
The image fixability, offset resistance and thermal efficiency were good. Further, the pulverizability of the resin used for these toners 1 to 4 was good, the productivity of the toner was high, and the transparency of the resin was also excellent. Further, from the results of Table 3, the toners 1 to 4 are more than those of the comparative toners 1 to 4 under normal environment (23 ° C., 50% RH) and high temperature and high humidity (35 ° C., 80%).
Since the change in the amount of charge in (% RH) is small and the image quality is good, it can be used under severe environmental conditions.

[0102]

According to the present invention, the amount of charge and the environmental stability of image quality are excellent, the pulverizability and the transparency are good, and in the heat roller fixing system, fixing is performed at a low temperature without using the offset preventing liquid. A possible binder resin can be manufactured. Further, by using such a binder resin, it is possible to obtain an electrophotographic toner and a developer having excellent performance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuhiro Semura 5- 1-4, Fukiage, Wakayama City, Wakayama Prefecture (72) Inventor Kuniyasu Kawabe 6-55 Komatsubara, Wakayama City, Wakayama Prefecture

Claims (13)

[Claims] 1. (a) A mixture of two raw material monomers of a polymerization system each having an independent reaction path in one reaction vessel,
(B) A compound capable of reacting with any of the two raw material monomers of the polymerization system and (c) a carboxylic acid having a valence of 3 or more or its derivative are mixed in advance, and the two polymerization reactions are carried out in parallel in the same reaction vessel. A method for producing a binder resin, which comprises: 2. The method according to claim 1, wherein the binder resin is a polycondensation resin and an addition polymerization resin. 3. The production method according to claim 2, wherein the weight ratio of the polycondensation resin to the addition polymerization resin is 50/50 to 95/5. 4. Polycondensation of polyester, polyester
The production method according to claim 2 or 3, wherein a polyamide or a polyamide is obtained, and the addition polymerization is a vinyl resin obtained by radical polymerization. 5. The average number molecular weight of the addition polymerization resin is 11,
It is 000 or less, The manufacturing method in any one of Claims 2-4. 6. A compound capable of reacting with any of two raw material monomers of a polymerization system is represented by the general formula (I) or (II): [In the formula, R ¹ , R ² and R ³ are the same or different and each is a hydrogen atom, a hydroxyl group or an optionally substituted alkyl group,
It represents an alkoxy group, an aryl group or a vinyl group or a halogen atom, which may be taken together to form a ring. A and B are the same or different and each represents an alkylene group represented by the general formula (III) or a phenylene group represented by the general formula (IV): (R ⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom,
It represents a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group, an aryl group or a vinyl group, or a halogen atom, which may together form a ring. m represents 0 to 5 and n represents an integer of 0 to 2), and X
And Y are the same or different and are —COOR ⁷ or —OR ⁸
(Wherein R ⁷ and R ⁸ represent a hydrogen atom or a lower alkyl group which may have a substituent)]. 7. The method according to claim 6, wherein the compound capable of reacting with any of the two raw material monomers of the polymerization system is at least one selected from the group consisting of compounds (1) to (36). [Chemical 3] [Chemical 4] [Chemical 5] 8. The production method according to claim 1, wherein the trivalent or higher carboxylic acid is trimellitic acid. 9. The addition amount of the compound capable of reacting with any of the two polymerization raw material monomers is 0.5 to 10% by weight based on the polycondensation raw material monomer. The manufacturing method described. 10. The method according to claim 1, wherein the amount of the trivalent or higher carboxylic acid added is 0.2 to 30% by weight based on the polycondensation raw material monomer. 11. The binder resin obtained has an acid value of 20 KOH.
It is below mg / g, The manufacturing method in any one of Claims 1-10. 12. The softening point of the obtained binder resin is 70 to 1.
It is 50 degreeC and the glass transition temperature is 50-80 degreeC, The manufacturing method in any one of Claims 1-11. 13. An electrophotographic toner containing a binder resin obtained by the method according to claim 1.