JP5584443B2 - Binder resin for electrophotographic toner - Google Patents

Description

  The present invention relates to a binder resin for an electrophotographic toner used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, a method for producing the same, and an electrophotographic toner containing the binder resin.

In recent years, from the pursuit of higher image quality, development of toners having excellent low-temperature fixability has been desired.
Patent Document 1 discloses an electrostatic latent image developing toner containing a binder resin including an amorphous polyester resin and a crystalline polyester resin, and includes a volume average particle size distribution index GSDv and a number average particle size distribution index GSDp. Ratio (GSDv / GSDp), weight average molecular weight (Mw) of the binder resin, ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn), shape factor SF1 and average shape distribution index An electrostatic latent image developing toner manufactured by an emulsion aggregation method in which (S ₈₄ / S ₁₆ ) ^1/2 is in a specific range is disclosed.
Patent Document 2 discloses a toner production method including a first step of producing a polyester dispersion by dispersing polyester in water and a second step of aggregating the polyester in the polyester dispersion.
In Patent Document 3, 3 to 50 parts by weight of crystalline polyester and 97 to 50 parts by weight of ion-crosslinked amorphous vinyl polymer are chemically bonded, and the chloroform-insoluble content is within a specific range. An electrostatic charge developing toner comprising a block copolymer or a graft copolymer as a binder resin is disclosed.

JP 2008-158197 A JP 2005-128176 A Japanese Patent Laid-Open No. 04-081770

However, since the emulsion aggregation method generally has less shear due to mixing, the conventional binder resin for an electrophotographic toner obtained by the emulsion aggregation method includes a crystalline resin and an amorphous resin. Is not uniformly and finely dispersed in an amorphous resin, and an electrophotographic toner having excellent low-temperature fixability, low image fogging, and high image glossiness is obtained using the binder resin. It was difficult to get.
An object of the present invention is to provide a binder resin for an electrophotographic toner having excellent low-temperature fixability, low image fogging and high image gloss, a method for producing the same, and an electrophotographic toner containing the binder resin. It is to be.

In the toner obtained by using an aqueous dispersion containing a crystalline resin composed of a composite resin containing a specific polycondensation resin and a styrene resin, the present inventors in an amorphous resin of the crystalline resin. It has been found that the toner can be uniformly and finely dispersed in the toner, and a toner excellent in image fog and image glossiness can be obtained while maintaining low-temperature fixability, and the above-mentioned problems can be solved.
Furthermore, the present inventors have disclosed a core shell in which the core portion includes a crystalline resin and an amorphous resin made of a composite resin including a specific condensation polymerization resin and a styrene resin, and the shell portion is an amorphous resin. It has been found that by using the particles as a binder resin, a toner excellent in image fog and image gloss can be obtained while maintaining low-temperature fixability, and the above problems can be solved.

The present invention provides the following [1] to [4].
[1] A binder resin for toner comprising a resin obtained by subjecting an aqueous dispersion containing a crystalline resin and an aqueous dispersion containing an amorphous resin to an aggregating step and a coalescing step. An electrophotographic toner in which the resin is a composite resin comprising a condensation polymerization resin component and a styrene resin component obtained by condensation polymerization of an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component Binder resin.
[2] A binder resin for toner comprising core-shell particles having a core part and a shell part, wherein the core part includes a crystalline resin and an amorphous resin, and the crystalline resin has 2 to 10 carbon atoms. A composite resin comprising a polycondensation resin component and a styrene resin component obtained by polycondensing an alcohol component containing an aliphatic diol and a carboxylic acid component, and an electron whose shell portion is an amorphous resin. Binder resin for photographic toner.
[3] An electrophotographic toner comprising the above [1] or [2].
[4] A method for producing a binder resin for an electrophotographic toner, comprising the following steps 1 to 3.
Step 1: Aqueous system containing a crystalline resin composed of a composite resin containing a condensation polymerization resin and a styrene resin obtained by condensation polymerization of an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component The process of obtaining the aqueous dispersion containing a dispersion liquid and an amorphous resin.
Step 2: The aqueous dispersion containing the crystalline resin obtained in Step 1 and the aqueous dispersion containing the amorphous resin are mixed and then subjected to an aggregation step to obtain an aqueous dispersion of resin particles (aggregated particles). Process.
Step 3: A step of obtaining an aqueous dispersion of resin particles (unified particles) by subjecting the aqueous dispersion of aggregated particles obtained in Step 2 to an unifying step.

  The electrophotographic toner containing the binder resin of the present invention has excellent low-temperature fixability, little image fogging, and high image gloss.

The toner for electrophotography of the present invention (hereinafter also simply referred to as “toner”) comprises an agglomeration step and a coalescence of an aqueous dispersion containing a crystalline resin made of a specific composite resin and an aqueous dispersion containing an amorphous resin. Resin obtained by being subjected to the process is contained as a binder resin, or "core shell particles" in which the core part contains a crystalline resin and an amorphous resin and the shell part is an amorphous resin Contained as.
By using a specific composite resin as the crystalline resin, in the toner obtained, the dispersion of the crystalline resin in the amorphous resin becomes uniform and fine, and while maintaining the low-temperature fixability, the image fog and image A toner having excellent glossiness can be obtained. This is presumably because the use of a specific composite resin as the crystalline resin improved the water dispersibility of the crystalline resin and controlled the dispersion diameter of the crystalline resin.

The crystallinity of the resin is represented by the ratio between the softening point and the maximum endothermic peak temperature measured by a differential scanning calorimeter, that is, the crystallinity index defined by “(softening point) / (maximum endothermic peak temperature)”. In general, when the crystallinity index exceeds 1.4, the resin is amorphous, and when it is less than 0.6, the crystallinity is low and there are many amorphous parts. In the present invention, the “crystalline resin” refers to a resin having a crystallinity index of 0.6 to 1.4, preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. “Amorphous resin” refers to a resin having a crystallinity index greater than 1.4 or less than 0.6.
Here, the highest endothermic peak temperature refers to the temperature of the peak on the highest temperature side among the endothermic peaks observed under the conditions of the measurement methods described in the examples. When the maximum peak temperature is within 20 ° C. from the softening point, the melting point of the crystalline resin is taken, and the peak with a difference from the softening point exceeding 20 ° C. is a peak due to the glass transition of the amorphous resin.
The crystallinity of the resin can be adjusted by the type and ratio of the raw material monomers, production conditions (for example, reaction temperature, reaction time, cooling rate) and the like.
In the present invention, the term “resin” means both a crystalline resin and an amorphous resin.

[Crystalline resin]
Examples of the crystalline resin include an alcohol component and a carboxylic acid containing an aliphatic diol having 2 to 10 carbon atoms from the viewpoints of improving the dispersibility of the crystalline resin, low-temperature fixability of the toner, image fogging, and image glossiness. A composite resin containing a condensation polymerization resin component and a styrene resin component obtained by condensation polymerization of the components is used.
(Condensation polymerization resin component)
The polycondensation resin component constituting the crystalline resin includes an alcohol component and a carboxylic acid component containing an aliphatic diol having 2 to 10 carbon atoms from the viewpoint of low-temperature fixability of the toner, image fogging, and image glossiness. Is a resin obtained by condensation polymerization.
Examples of the condensation polymerization resin component include polyester, polyester / polyamide, and the like. From the viewpoint of low-temperature fixability of the toner, polyester is preferable.

-Alcohol component-
The alcohol component, which is a raw material monomer of the condensation polymerization resin component, is an aliphatic diol having 2 to 10 carbon atoms, preferably 4 to 8 carbon atoms, more preferably 4 to 6 carbon atoms, from the viewpoint of enhancing the crystallinity of the resin. contains.
Examples of the aliphatic diol having 2 to 10 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, Examples include 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, and 1,4-butenediol. In particular, from the viewpoint of crystallinity, α, ω-linear alkanediol having 2 to 10 carbon atoms is preferable, 1,4-butanediol and 1,6-hexanediol are more preferable, and 1,6-hexanediol is more preferable. .

  From the viewpoint of enhancing the crystallinity of the crystalline resin, the content of the aliphatic diol is preferably 70 mol% or more, more preferably 80 to 100 mol%, and still more preferably 90 to 100 mol%, in the alcohol component. . In particular, the proportion of the aliphatic diol in the above examples in the alcohol component is preferably 70 mol% or more, more preferably 80 to 95 mol%. The content of one kind of α, ω-linear alkanediol in the alcohol component is preferably 70 mol% or more, more preferably 70 to 100 mol%, still more preferably 90 to 100 mol%.

  Examples of the polyhydric alcohol component other than the aliphatic diol having 2 to 10 carbon atoms that can be used as the alcohol component include, for example, a polyoxypropylene adduct of 2,2-bis (4-hydroxyphenyl) propane, 2,2- Aromatic diols such as alkylene oxide adducts of bisphenol A represented by the following formula (I) including polyoxyethylene adducts of bis (4-hydroxyphenyl) propane; 3 such as glycerin, pentaerythritol, trimethylolpropane, etc. Alcohols having a value higher than that are listed.

（式中、Ｒは、炭素数２又は３のアルキレン基を示す。ｘ及びｙは、正の数を示し、ｘとｙの和は、１〜１６、好ましくは１．５〜５である。）

(In formula, R shows a C2-C3 alkylene group. X and y show a positive number, and the sum of x and y is 1-16, Preferably it is 1.5-5. )

Furthermore, the use of a monovalent aliphatic alcohol as the alcohol component controls the terminal carboxy group of the condensation polymerization resin component, improves the water dispersibility of the crystalline resin, and reduces the fogging of the toner image. In addition, it is preferable from the viewpoint of obtaining high glossiness of an image.
The monovalent aliphatic alcohol preferably has 12 to 22 carbon atoms, more preferably 14 to 18 carbon atoms.
In the case where a monovalent aliphatic alcohol is used in combination, the amount used thereof is preferably 2 to 20 mol%, more preferably 4 to 15 mol%, from the same viewpoint as described above.
Two or more alcohol components can be used in combination.

-Carboxylic acid component-
The carboxylic acid component which is a raw material monomer of the condensation polymerization resin component is preferably an aromatic dicarboxylic acid compound from the viewpoint of low-temperature fixability of the toner, image fogging and image glossiness.
The aromatic dicarboxylic acid compound also includes an aromatic dicarboxylic acid derivative that can become the same structural unit as the structural unit derived from the aromatic dicarboxylic acid by a condensation reaction. Specific examples of the aromatic dicarboxylic acid compound preferably include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid, anhydrides of these acids, and alkyl (C1 to C3) esters thereof. Examples of the alkyl group in the alkyl ester include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Among these, terephthalic acid or its alkyl (C1-C3) ester is preferable from the viewpoints of low-temperature fixability of the toner, fogging of the image, and glossiness of the image.
The content of the aromatic dicarboxylic acid compound is preferably 60 to 99 mol%, more preferably 70 to 99 mol% in the carboxylic acid component, from the viewpoints of low-temperature fixability of the toner, image fogging and image gloss. More preferably, it is 90-99 mol%.

  In the present invention, a divalent carboxylic acid other than those described above or a trivalent or higher polyvalent carboxylic acid can be used as the carboxylic acid component. As the divalent carboxylic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid and the like are preferable, and the carbon number is 4 to 10, more preferably 4 carbon atoms. An aliphatic dicarboxylic acid having ˜8; succinic acid substituted with an alkyl group having 1 to 8 or 15 carbon atoms or an alkenyl group having 2 to 8 or 15 carbon atoms; anhydrides of those acids and those acids Alkyl (C1-C3) ester etc. are mentioned.

Examples of the trivalent or higher polyvalent carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid and other aromatic carboxylic acids, and acids thereof. Derivatives such as anhydrides and alkyl (1 to 3 carbon atoms) esters may be mentioned. Among the trivalent or higher polyvalent carboxylic acids, trimellitic acid and acid anhydrides thereof are preferable from the viewpoint of inexpensiveness and easy reaction control.
When a trivalent or higher polyvalent carboxylic acid is used as the carboxylic acid component, the amount used is from 0.1 to 30 in the carboxylic acid component from the viewpoint of low-temperature fixability of the toner, image fogging and image gloss. Mol% is preferable, 1 to 25 mol% is more preferable, and 5 to 25 mol% is more preferable.

Furthermore, using a monovalent aliphatic carboxylic acid as a raw material monomer for the condensation polymerization resin component controls the hydroxyl group at the terminal of the condensation polymerization resin component and improves the water dispersibility of the crystalline resin, This is preferable from the viewpoint of reducing the fog of the toner image and obtaining high glossiness of the image.
The monovalent aliphatic carboxylic acid preferably has 12 to 22 carbon atoms, more preferably 14 to 18 carbon atoms.
In the case of using a monovalent aliphatic carboxylic acid in combination, the amount used thereof is preferably 2 to 20 mol%, more preferably 4 to 15 mol%, respectively, from the same viewpoint as described above in the carboxylic acid component.
A carboxylic acid component can also be used in combination of 2 or more types.
In addition, in this specification, the both reactive monomers mentioned later shall not be included in calculation of content of an alcohol component or a carboxylic acid component.

The total number of moles of the aromatic dicarboxylic acid compound and the aliphatic diol having 2 to 10 carbon atoms in the total number of moles of the carboxylic acid component and the alcohol component, which are raw material monomers for constituting the condensation polymerization resin component, From the viewpoint of low-temperature fixability of toner, image fogging and image glossiness, it is preferably 75 to 100 mol%, more preferably 80 to 95 mol%.
The molar ratio of the carboxylic acid component to the alcohol component (carboxylic acid component / alcohol component) is preferably higher in the alcohol component than the carboxylic acid component when the crystalline resin is made to have a high molecular weight. In the reaction, from the viewpoint that the molecular weight of the resin can be easily adjusted by distilling off the alcohol component, it is preferably 0.9 or more and less than 1, and more preferably 0.95 or more and less than 1.

(Styrene resin component)
As a raw material monomer for the styrene resin component, styrene or styrene derivatives such as α-methylstyrene and vinyltoluene (hereinafter, styrene and styrene derivatives are collectively referred to as “styrene derivatives”) is used.
The content of the styrene derivative is preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 90% by weight or more in the raw material monomer of the styrene resin component, from the viewpoint of fogging and glossiness of the toner image. .

Raw material monomers for styrene resin components used in addition to styrene derivatives include (meth) acrylic acid alkyl esters; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; and halovinyls such as vinyl chloride. Vinyl esters such as vinyl acetate and vinyl propionate; unsaturated monomers containing amino groups such as dimethylaminoethyl (meth) acrylate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N- Examples thereof include N-vinyl compounds such as vinyl pyrrolidone.
The raw material monomer of the styrene resin component can be used in combination of two or more. In the present specification, “(meth) acrylic acid” means acrylic acid and / or methacrylic acid.

Among the raw material monomers for the styrene resin component used in addition to the styrene derivative, (meth) acrylic acid alkyl ester is preferable from the viewpoint of low-temperature fixability of the toner, image fogging and image glossiness. 1-22 are preferable from said viewpoint, and, as for carbon number of the alkyl group in (meth) acrylic-acid alkylester, 8-18 are more preferable. In addition, carbon number of this alkyl ester says carbon number derived from the alcohol component which comprises ester.
Specific examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (iso or tertiary). ) Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) decyl (meth) acrylate, (iso) stearyl (meth) acrylate, and the like. Here, “(iso or tertiary)” and “(iso)” mean that both of these groups are present and not present, and these groups are not present. Indicates normal. In addition, “(meth) acrylate” indicates that both acrylate and methacrylate are included.

The content of the (meth) acrylic acid alkyl ester is preferably 30% by weight or less, and preferably 20% by weight or less, in the raw material monomer of the styrene resin component, from the viewpoint of low-temperature fixability of the toner, image fog and image gloss. Is more preferable, and 10% by weight or less is more preferable.
A resin obtained by addition polymerization of a raw material monomer containing a styrene derivative and a (meth) acrylic acid alkyl ester is also referred to as a styrene- (meth) acrylic resin.

The addition polymerization reaction of the raw material monomer of the styrenic resin component can be carried out in the usual manner, for example, in the presence of a polymerization initiator, a crosslinking agent, etc., in the presence of an organic solvent or in the absence of a solvent. 120 degreeC or more and less than 180 degreeC are preferable, and 165 degreeC or more and less than 180 degreeC are more preferable.
Examples of the polymerization initiator include benzoyl peroxide; tertiary butyl peroxybenzoate; diisopropyl peroxide; dicumyl peroxide; tertiary butyl peroxydiisopropyl carbonate; 1,3-bis (tertiary butyl peroxyisopropyl) benzene; Known organic oxides such as 2,2-ditertiary butyl peroxybutane can be used. You may use these individually or in combination of 2 or more types.
An organic solvent can be used in the addition polymerization reaction. As the organic solvent, xylene, toluene, methyl ethyl ketone, acetone or the like can be used. When the organic solvent is used, the amount used is preferably about 10 to 50 parts by weight with respect to 100 parts by weight of the raw material monomer of the styrene resin component.
The number average molecular weight of the styrenic resin component is preferably 400 to 7000, more preferably 1000 to 4000 from the viewpoint of improving dispersibility in the crystalline resin that is a composite resin, reducing the fog of the image, and increasing the gloss. Preferably, 1500 to 3000 is more preferable. The number average molecular weight can be adjusted by the amount of radical polymerization initiator used, the reaction temperature, the monomer dropping time, etc. Specifically, the amount used can be increased, the reaction temperature can be increased, the monomer dropped The longer the time, the smaller. In the present invention, the number average molecular weight of the styrene resin refers to a value obtained by measuring a tetrahydrofuran (THF) soluble content.

(Composite resin)
The crystalline resin used in the present invention is composed of a composite resin containing the condensation polymerization resin component and the styrene resin component, and each resin component is bonded directly or via a linking group. Examples of the linking group include a compound derived from an amphoteric monomer and a chain transfer agent described later, other resins, and the like.
The composite resin is a resin in which the condensation polymerization resin component and the styrene resin component are mutually dispersed, and the dispersion state is a glass transition temperature derived from the styrene resin component in the composite resin as follows. It can be evaluated by the difference between the measured value (hereinafter referred to as Tg) and the measured value of Tg derived from the condensation polymerization resin component.

That is, the composite resin used in the present invention is a crystalline resin but has an amorphous part derived from a styrene resin component and a condensation polymerization resin component, and Tg is measured in the composite resin. Can do.
The Tg of the styrene resin component and the Tg of the condensation polymerization resin component in the composite resin are values measured separately. As the dispersion of the condensation polymerization resin component and the styrene resin component becomes more uniform, Of Tg approach each other. Therefore, when the condensation polymerization resin component and the styrene resin component are in a substantially uniform dispersion state, it is considered that both Tg's overlap and the measured value becomes almost one.
Therefore, in the measurement method described later, from the viewpoint of image glossiness and fogging, the composite resin preferably has one Tg, and the Tg temperature in that case is preferably 3 to 50 ° C, and 5 to 40 ° C. More preferably, 10-30 degreeC is still more preferable.

The composite resin can be obtained, for example, by the following method (1) or (2).
(1) A method in which a raw material monomer of a condensation polymerization resin component is subjected to condensation polymerization in the presence of a styrene resin component having a carboxy group or a hydroxyl group. In addition, as said carboxy group and a hydroxyl group, the thing derived from the both reactive monomer mentioned later and a chain transfer agent is mentioned.
(2) A method in which a raw material monomer of a styrene resin component is subjected to addition polymerization in the presence of a condensation polymerization resin having a reactive unsaturated bond.

From the viewpoints of low-temperature fixability of the toner and fog and glossiness of the toner, the above composite resin is used in addition to the raw material monomer of the condensation polymerization resin component and the raw material monomer of the styrene resin component, and further, the raw material monomer of the condensation polymerization resin component And a resin (hybrid resin) obtained by using both reactive monomers capable of reacting with any of the raw material monomers of the styrene resin component. Therefore, when polymerizing the raw material monomer of the condensation polymerization resin component and the raw material monomer of the styrene resin component to obtain a composite resin, the condensation polymerization reaction and / or the addition polymerization reaction should be performed in the presence of both reactive monomers. Is preferred. As a result, the composite resin becomes a resin (hybrid resin) in which a condensation polymerization resin component and a styrene resin component are bonded via a structural unit derived from both reactive monomers, and the condensation polymerization resin component and the styrene resin component Becomes more finely and uniformly dispersed.
From these, the composite resin is (a) a raw material monomer of a polycondensation-based resin component containing an alcohol component containing a C2-C10 aliphatic diol and a carboxylic acid component, and (b) a raw material of a styrene-based resin component. It is a resin obtained by polymerizing monomers, and (c) both reactive monomers capable of reacting with either the raw material monomer of the condensation polymerization resin component and the raw material monomer of the styrene resin component, preferably in the same container. It is preferable.

Examples of the both reactive monomers include compounds having at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Among these, a compound having a hydroxyl group and / or a carboxyl group is preferable, and a compound having a carboxyl group and an ethylenically unsaturated bond is more preferable. By using such a bireactive monomer, the dispersibility of the resin that becomes the dispersed phase can be further improved.
As the both reactive monomers, at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride is more preferable. From the viewpoint of the reactivity of the polycondensation reaction and the addition polymerization reaction, acrylic acid is preferable. Even more preferred are acids, methacrylic acid or fumaric acid. However, when used together with a polymerization inhibitor, a polyvalent carboxylic acid such as fumaric acid may function as a condensation polymerization monomer.

  The amount of both reactive monomers used increases the dispersibility of the styrene resin component and the condensation polymerization resin component, and from the viewpoint of low-temperature fixability of the toner, image fogging and image gloss, 2 to 25 mol is preferable, 3 to 20 mol is more preferable, 5 to 18 mol is more preferable, 8 to 15 mol is even more preferable, and a raw material for the styrenic resin component, relative to a total of 100 mol of alcohol components. 2-25 mol is preferable with respect to a total of 100 mol of monomers, 3-20 mol is more preferable, 5-18 mol is more preferable, and 6-13 mol is still more preferable.

  Specifically, the composite resin is preferably produced by the following methods (i) to (iii). In addition, from the viewpoints of low-temperature fixability of the toner, image fogging, and image glossiness, in any of the methods (i) to (iii), both reactive monomers together with the raw material monomer of the styrene resin component are addition polymerization reaction systems. Is preferably supplied.

(I) A method of performing a step (B) of an addition polymerization reaction using a raw material monomer of a styrenic resin component and an amphoteric monomer after the step (A) of the condensation polymerization reaction using the raw material monomer of the condensation polymerization resin component.
In this method, the step (A) is performed under a reaction temperature condition suitable for the condensation polymerization reaction, the reaction temperature is lowered, and the step (B) is performed under a temperature condition suitable for the addition polymerization reaction. It is preferable to add the raw material monomer of the styrene resin component and the both reactive monomers to the reaction system at a temperature suitable for the addition polymerization reaction. Both reactive monomers undergo an addition polymerization reaction and also a condensation polymerization resin component.
After the step (B), the reaction temperature is raised again, and if necessary, a tri- or higher-valent raw material monomer of the condensation polymerization resin component is added to the polymerization system as a crosslinking agent, and the condensation polymerization reaction in the step (A). And the reaction with both reactive monomers can be further advanced.

(Ii) A method in which the step (A) of the condensation polymerization reaction with the raw material monomer of the condensation polymerization resin component is performed after the step (B) of the addition polymerization reaction with the raw material monomer of the styrene resin component and the both reactive monomers.
In this method, the step (B) is performed under a reaction temperature condition suitable for the addition polymerization reaction, the reaction temperature is increased, and the condensation polymerization reaction of the step (A) is performed under a temperature condition suitable for the condensation polymerization reaction. Both reactive monomers are involved in the condensation polymerization reaction as well as the addition polymerization reaction.
The raw material monomer of the condensation polymerization resin component may be present in the reaction system during the addition polymerization reaction, or may be added to the reaction system under temperature conditions suitable for the condensation polymerization reaction. In the former case, it can be adjusted by adding an esterification catalyst at a temperature suitable for the condensation polymerization reaction.

(Iii) A method in which the step (A) of the condensation polymerization reaction using the raw material monomer of the condensation polymerization resin component and the step (B) of the addition polymerization reaction using the raw material monomer and both reactive monomers of the styrene resin component are performed in parallel.
In this method, step (A) and step (B) are performed under reaction temperature conditions suitable for addition polymerization reaction, the reaction temperature is increased, and under temperature conditions suitable for condensation polymerization reaction, if necessary, It is preferable to add a trivalent or higher-valent raw material monomer or the like of the condensation polymerization resin component to the polymerization system as a crosslinking agent, and further perform the condensation polymerization reaction in step (A). At that time, under a temperature condition suitable for the condensation polymerization reaction, a radical polymerization inhibitor can be added to advance only the condensation polymerization reaction. Both reactive monomers are involved in the condensation polymerization reaction as well as the addition polymerization reaction.

In the method (i), a prepolymerized polycondensation resin may be used in place of the step (A) of performing the polycondensation reaction. In the method (iii), when the step (A) and the step (B) are performed in parallel, the raw material monomer of the styrene resin component is contained in the mixture containing the raw material monomer of the condensation polymerization resin component. It is also possible to carry out the reaction by dropping the prepared mixture.
The temperature suitable for the addition polymerization reaction is preferably 120 ° C. or more and less than 180 ° C., more preferably 165 ° C. or more and less than 180 ° C. from the viewpoint of increasing the fog and glossiness of the image with the number average molecular weight of the styrene resin within the above range. preferable. The temperature suitable for the condensation polymerization reaction is preferably 180 to 250 ° C, and more preferably 180 to 230 ° C.
The methods (i) to (iii) are preferably performed in the same container.

  The crystalline resin used in the present invention is composed of the above composite resin. The weight ratio of the condensation polymerization resin component to the styrene resin component (the total amount of the raw material monomer of the condensation polymerization resin component / the total amount of the raw material monomer of the styrene resin component) is the low-temperature fixability of the toner, image fogging and image 60/40 to 95/5 is preferable, and 60/40 to 90/10 is more preferable because the continuous phase is preferably a condensation polymerization resin and the dispersed phase is preferably a styrene resin. 70/30 to 88/12 are more preferable. In the above calculation, the amount of both reactive monomers is included in the raw material monomer of the condensation polymerization resin component.

(Physical properties of crystalline resin)
The number average molecular weight of the crystalline resin used in the present invention is preferably 1000 or more, and more preferably 1500 or more, from the viewpoints of low-temperature fixability of the toner, image fog and image gloss. However, considering the productivity of the crystalline resin, the number average molecular weight is preferably 5000 or less, more preferably 4000 or less, further preferably 3000 or less, preferably 1000 to 5000, more preferably 1000 to 4000, and 1500 to 3000. Even more preferred.
Further, the weight average molecular weight is preferably 3000 or more, more preferably 5000 or more, further preferably 8000 or more, preferably 100,000 or less, more preferably 50000 or less, and further preferably 30000 from the same viewpoint as the number average molecular weight. Hereinafter, it is particularly preferably 20000 or less, preferably 3000-100000, more preferably 5000-50000, still more preferably 5000-30000, and still more preferably 8000-20000.
In the present invention, the number average molecular weight and the weight average molecular weight of the crystalline resin are both values obtained by measuring the chloroform-soluble content.
The storage elastic modulus (G ′) at 160 ° C. of the crystalline resin is preferably from 0.01 to 1000, more preferably from 0.1 to 100, still more preferably from 1 to 50, from the viewpoint of image fog and gloss. Is even more preferable.

In order to obtain a high molecular weight crystalline resin, as described above, the molar ratio of the carboxylic acid component and the alcohol component is adjusted, the reaction temperature is increased, the amount of the catalyst is increased, and the dehydration reaction is performed for a long time under reduced pressure. The reaction conditions such as these may be selected. Although a high-power motor can be used to produce a high molecular weight crystalline resin, the raw material monomer can be used as a non-reactive low-viscosity resin or solvent when producing without particularly selecting production equipment A method of reacting together is also an effective means.
The softening point of the crystalline resin is preferably from 80 to 160 ° C., more preferably from 80 to 140 ° C., still more preferably from 90 to 130 ° C., from the viewpoints of low-temperature fixability of the toner, image fogging, and image gloss. More preferably, ˜120 ° C.
The melting point of the crystalline resin is preferably 60 to 130 ° C., more preferably 75 to 120 ° C., and still more preferably 90 to 110 ° C., from the viewpoints of low-temperature fixability of the toner, image fog and image gloss. is there.
The softening point and melting point can be easily adjusted by adjusting the raw material monomer composition, the polymerization initiator, the molecular weight, the catalyst amount, etc., or selecting the reaction conditions.

[Amorphous resin]
The amorphous resin is preferably a condensation polymerization resin obtained by condensation polymerization of an alcohol component and a carboxylic acid component. In the present invention, the amorphous resin comprises an alcohol component containing 70 mol% or more of an alkylene oxide adduct of bisphenol A represented by the above formula (I) and / or an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid. A polyester resin obtained by polycondensation with an acid component is preferred.
-Alcohol component-
The total content of the alkylene oxide adduct of bisphenol A and / or the aliphatic diol having 2 to 10 carbon atoms is preferably 70 mol% or more, more preferably 80 to 100 mol%, still more preferably 90% in the alcohol component. ˜100 mol%. As the aliphatic diol having 2 to 10 carbon atoms, an aliphatic diol having 2 to 5 carbon atoms is preferable, and 1,2-propanediol is more preferable. The use of an alkylene oxide adduct of bisphenol A improves environmental stability.
Examples of the alcohol other than the alkylene oxide adduct of bisphenol A that can be contained in the alcohol component include trivalent or higher alcohols similar to those used for the crystalline resin.

-Carboxylic acid component-
The carboxylic acid component of the amorphous resin is described as the carboxylic acid component used in the crystalline resin from the viewpoint of enhancing the compatibility between the amorphous resin and the crystalline resin, and from the viewpoint of image fogging and image gloss. It is preferable to contain the same aromatic dicarboxylic acid compound as described above, and it is more preferable to contain a terephthalic acid compound.
The content of the aromatic dicarboxylic acid compound is preferably 30 to 95 mol%, more preferably 40 to 90 mol%, still more preferably 50 to 85 mol% in the carboxylic acid component.
Examples of the divalent carboxylic acid and trivalent or higher polyvalent carboxylic acid other than the aromatic dicarboxylic acid compound that can be used include the same as those used for the crystalline resin.

(Physical properties of amorphous resin)
The softening point of the amorphous resin is preferably 70 to 180 ° C, more preferably 90 to 150 ° C, from the viewpoint of low-temperature fixability. The amorphous resin used in the present invention is superior in terms of low-temperature fixability of the toner, image fogging and image glossiness by using a resin having a high softening point and a low resin in combination. Specifically, the softening point of the high softening point resin is preferably 110 to 150 ° C, the softening point of the low softening point resin is preferably 90 to 105 ° C, and the softening point is preferably 10 ° C or higher. More preferably, two types different from 15 to 30 ° C. are used. The weight ratio of the high softening point resin to the low softening point resin (high softening point resin / low softening point resin) is preferably 1/3 to 3/1, more preferably 1/3 to 2/1, and more preferably 1/2 to 2/1 is more preferable.

The Tg of the amorphous resin is preferably 45 to 80 ° C., more preferably 55 to 75 ° C. from the viewpoint of low-temperature fixability. Tg is distinguished from the highest peak temperature of heat of fusion.
The number average molecular weight of the amorphous resin is preferably 1,000 to 6,000, and more preferably 2,000 to 5,000. The weight average molecular weight is preferably 10,000 or more, more preferably 30,000 or more, and preferably 1,000,000 or less. The number average molecular weight and the weight average molecular weight of the amorphous resin are both values obtained by measuring the tetrahydrofuran soluble content.

(Modified amorphous resin)
The amorphous resin used in the present invention includes a modified amorphous resin.
Examples of the modified amorphous resin include a urethane-modified polyester in which the resin is modified with a urethane bond, an epoxy-modified polyester in which the polyester is modified with an epoxy bond, and a hybrid resin having two or more resins including a polyester component. Can be mentioned.
As the amorphous resin, either one of the polyester resin and the modified amorphous resin may be used in combination. Specifically, the polyester and / or a hybrid having a polyester and a styrene resin may be used. Resin may be used.

(Method for producing crystalline resin and amorphous resin)
In any of the crystalline resin and the amorphous resin, the condensation polymerization of the alcohol component and the carboxylic acid component is preferably performed in the presence of an esterification catalyst, from the viewpoint of obtaining a resin having a high storage elastic modulus. More preferably, it is carried out in the presence of an esterification catalyst and a pyrogallol compound.
Examples of the esterification catalyst suitably used for the polycondensation include a titanium compound and a tin (II) compound having no Sn—C bond, and these can be used alone or in combination.
As a titanium compound, the titanium compound which has a Ti-O bond is preferable, and the compound which has a C1-28 total carbon number alkoxy group, an alkenyloxy group, or an acyloxy group is more preferable.

Specific examples of titanium compounds include titanium diisopropylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₃ H ₇ O) ₂ ], titanium diisopropylate bisdiethanolamate [Ti (C _{4 H 10 O 2 N) 2 (} C 3 H 7 O) 2 ], titanium dipentylate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (C 5 H 11 O) 2 ], Chitanjiechi rate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (C 2 H 5 O) 2 ], titanium dihydroxy octylate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (OHC 8 H ₁₆ O) ₂ ], titanium distearate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₁₈ H ₃₇ O) ₂ ], titanium triisopropylate triethanolamate [Ti (C _{6 H 14 O 3 N) 1 (} C 3 ₇ O) _3], and titanium monopropylate tris (triethanolaminate) _{[Ti (C 6 H 14 O 3} N) 3 (C 3 H 7 O) 1 ], and the like. Among these, titanium diisopropylate bistriethanolamate, titanium diisopropylate bisdiethanolamate, and titanium dipentylate bistriethanolaminate are preferable, and these are also available as, for example, commercial products of Matsumoto Trading Co., Ltd. It is.

Specific examples of other preferable titanium compounds include tetra-n-butyl titanate [Ti (C ₄ H ₉ O) ₄ ], tetrapropyl titanate [Ti (C ₃ H ₇ O) ₄ ], tetrastearyl titanate [Ti ( C ₁₈ H ₃₇ O) ₄ ], tetramyristyl titanate [Ti (C ₁₄ H ₂₉ O) ₄ ], tetraoctyl titanate [Ti (C ₈ H ₁₇ O) ₄ ], dioctyl dihydroxyoctyl titanate [Ti (C ₈ H ₁₇ O) ₂ (OHC ₈ H ₁₆ O) ₂ ], dimyristyl dioctyl titanate [Ti (C ₁₄ H ₂₉ O) ₂ (C ₈ H ₁₇ O) ₂ ] and the like. Among these, tetrastearyl titanate, tetramyristyl titanate, tetraoctyl titanate, and dioctyl dihydroxyoctyl titanate are preferable, and these can be obtained by reacting, for example, titanium halide with a corresponding alcohol. It is also available as a commercial product such as

Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having a Sn—O bond, a tin (II) compound having a Sn—X (X represents a halogen atom) bond, and the like. Preferred examples include tin (II) compounds having a Sn-O bond.
Examples of tin (II) compounds having a Sn-O bond include tin (II) oxalate, tin (II) diacetate, tin (II) dioctanoate, tin (II) dilaurate, tin (II) distearate, and Tin (II) carboxylate having a carboxylic acid group having 2 to 28 carbon atoms such as tin (II) dioleate; dioctyloxytin (II), dilauroxytin (II), distearoxytin (II), and dioleoxytin (II) Dialkoxytin (II) having an alkoxy group having 2 to 28 carbon atoms, such as tin oxide (II) and tin sulfate (II).

Examples of the compound having a Sn-X (X represents a halogen atom) bond include tin (II) halides such as tin (II) chloride and tin (II) bromide. Among them, fatty acid tin represented by (R ¹ COO) ₂ Sn (wherein R ¹ represents an alkyl group or alkenyl group having 5 to 19 carbon atoms) from the standpoint of charge rising effect and catalytic ability. (II), represented by (R ² O) ₂ Sn (wherein R ² represents an alkyl group or alkenyl group having 6 to 20 carbon atoms) and represented by SnO Tin (II) oxide is preferred, fatty acid tin (II) and tin (II) oxide represented by (R ¹ COO) ₂ Sn are more preferred, tin (II) dioctanoate, tin (II) distearate, and oxidation More preferred is tin (II).
The said titanium compound and a tin (II) compound can be used 1 type or in combination of 2 or more types.
The amount of the esterification catalyst present is preferably 0.01 to 1.0 part by weight and more preferably 0.1 to 0.6 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  The pyrogallol compound has a benzene ring in which three hydrogen atoms adjacent to each other are substituted with a hydroxyl group, and pyrogallol, gallic acid, gallic acid ester, 2,3,4-trihydroxybenzophenone, 2,2 Examples include benzophenone derivatives such as', 3,4-tetrahydroxybenzophenone, and catechin derivatives such as epigallocatechin and epigallocatechin gallate.

The abundance of the pyrogallol compound in the condensation polymerization reaction is preferably 0.001 to 1.0 part by weight and more preferably 0.005 to 0.4 part by weight with respect to 100 parts by weight of the raw material monomer to be subjected to the condensation polymerization reaction. Preferably, 0.01-0.2 weight part is further more preferable. Here, the abundance of the pyrogallol compound means the total amount of the pyrogallol compound subjected to the condensation polymerization reaction.
The weight ratio of the pyrogallol compound and the esterification catalyst (pyrogallol compound / esterification catalyst) is preferably 0.01 to 0.5, more preferably 0.03 to 0.3, from the viewpoint of the durability of the resin. 05 to 0.2 are more preferable.

In both the polycondensation resin component and the amorphous resin of the crystalline resin, the polycondensation reaction between the alcohol component and the carboxylic acid component is performed by, for example, an esterification catalyst such as a tin compound or a titanium compound, or a polymerization inhibitor. In the presence of an inert gas atmosphere, the temperature condition is preferably 180 to 250 ° C., more preferably 180 to 230 ° C. for both the polycondensation resin component of the crystalline resin and the amorphous resin. preferable.
Specifically, for example, all monomers are charged at once in order to increase the strength of the resin, or divalent raw material monomers are first reacted to reduce low molecular weight components, and then trivalent or higher raw material monomers are added. The method of making it react may be used. Further, the reaction may be accelerated by reducing the pressure of the reaction system in the latter half of the polymerization.

[Binder resin]
The binder resin for electrophotographic toner of the present invention is:
Aspect 1: A resin obtained by subjecting an aqueous dispersion containing the crystalline resin and an aqueous dispersion containing the amorphous resin to an aggregation step and a coalescence step, or an aspect 2: the core portion is The “core-shell particles”, which include the crystalline resin and the amorphous resin, and the shell portion is the amorphous resin, preferably the aqueous dispersion containing the crystalline resin and the amorphous The “core-shell particles” are made of a resin obtained by subjecting an aqueous dispersion containing a resin to the aggregation step and the coalescence step, and the shell portion is the amorphous resin.
The acid value of the crystalline resin, the amorphous resin, and the binder resin containing them is preferably 1 to 40 mgKOH / g, and preferably 2 to 35 mgKOH / g from the viewpoint of good chargeability and hydrolysis resistance of the toner. g is more preferable, and 3 to 30 mgKOH / g is more preferable.
Furthermore, the crystalline resin, the amorphous resin, and the binder resin containing these are preferably excellent in solubility in an organic solvent.
The weight ratio of the crystalline resin to the amorphous resin (crystalline resin / amorphous resin) in the binder resin is the same as in Embodiments 1 and 2 in terms of low-temperature fixability of the toner, image fog, and image gloss. From this viewpoint, 5/95 to 50/50 are preferable, 10/90 to 40/60 are more preferable, and 15/85 to 35/65 are even more preferable.

The electrophotographic toner of the present invention is a known toner binder resin different from the electrophotographic toner binder resin of the present invention, for example, polyester, styrene-acrylic resin, etc., as long as the effects of the present invention are not impaired. These resins such as styrenic resin, epoxy resin, polycarbonate, and polyurethane may be used in combination.
The content of the binder resin of the present invention in the electrophotographic toner of the present invention is preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, based on the total binder resin. More preferably, it is more preferably 100% by weight or more.

[Method for producing toner for electrophotography]
The method for producing the electrophotographic toner of the present invention is not particularly limited, and can be obtained, for example, by subjecting an aqueous dispersion containing a crystalline resin and an aqueous dispersion containing an amorphous resin to an aggregation step and a coalescence step. It is done. Specifically, it can be obtained by a production method including the following steps 1 to 3.
Step 1: Aqueous system containing a crystalline resin composed of a composite resin containing a condensation polymerization resin and a styrene resin obtained by condensation polymerization of an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component The process of obtaining the aqueous dispersion containing a dispersion liquid and an amorphous resin.
Step 2: The aqueous dispersion containing the crystalline resin obtained in Step 1 and the aqueous dispersion containing the amorphous resin, and further, if necessary, the colorant dispersion, the release agent dispersion, and the charge control agent dispersion. A step of obtaining an aqueous dispersion of resin particles (aggregated particles) by mixing and then subjecting to an aggregation step.
Step 3: A step of obtaining an aqueous dispersion of resin particles (unified particles) by subjecting the aqueous dispersion of aggregated particles obtained in Step 2 to an unifying step.

The steps 1 to 3 will be described in detail.
In the present specification, the aqueous system may contain a solvent such as an organic solvent, but water is preferably 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. Preferably it contains 99% by weight or more.
The aqueous dispersion containing a resin means an aqueous dispersion containing a crystalline resin and / or an aqueous dispersion containing an amorphous resin.

<Process 1>
Step 1 is a step of separately producing an aqueous dispersion containing a crystalline resin and an aqueous dispersion containing an amorphous resin.
An aqueous dispersion containing a crystalline resin or an aqueous dispersion containing an amorphous resin is prepared by mixing a crystalline resin or an amorphous resin, an organic solvent and water, and, if necessary, a neutralizing agent or a surfactant. After stirring, it can be obtained by removing the organic solvent from the obtained dispersion.
Preferably, after a crystalline resin or an amorphous resin is dissolved in an organic solvent, water and, if necessary, a neutralizing agent and a surfactant are mixed.
The weight ratio of the crystalline resin or amorphous resin to the organic solvent is preferably 100 to 1000 parts by weight with respect to 100 parts by weight of the crystalline resin or amorphous resin. The weight ratio of the organic solvent to water is preferably 100 to 1000 parts by weight with respect to 100 parts by weight of the organic solvent. The amount of the aqueous medium used is preferably 100 to 3000 parts by weight with respect to 100 parts by weight of the total amount of the crystalline resin and the amorphous resin from the viewpoint of obtaining uniform aggregated particles in the aggregation step in Step 2 described later. 400 to 3000 parts by weight is more preferable, and 800 to 3000 parts by weight is more preferable. A preferred weight ratio between the crystalline resin and the amorphous resin is the same as the weight ratio between the crystalline resin and the amorphous resin in the binder resin.
30-90 degreeC is preferable and the temperature at the time of melt | dissolving crystalline resin or an amorphous resin in an organic solvent has more preferable 40-80 degreeC. The temperature at which the crystalline resin is dissolved in the organic solvent is preferably higher than the temperature at which the amorphous resin is dissolved in the organic solvent from the viewpoints of solubility, image fogging, and glossiness.

Examples of the organic solvent include alcohol solvents such as ethanol, isopropanol, and isobutanol; ketone solvents such as acetone, 2-butanone, methyl ethyl ketone, methyl isobutyl ketone, and diethyl ketone; ether solvents such as dibutyl ether, tetrahydrofuran, and dioxane. Solvent; ethyl acetate is mentioned. Of these, ethyl acetate and 2-butanone are preferred from the viewpoints of dispersibility of the crystalline resin, fogging of the image, and glossiness of the image.
Examples of the neutralizing agent include alkali metals such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; organic bases such as ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, triethanolamine, and tributylamine.
Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate ester, and soap (such as alkyl ether carboxylate); amine salt type, quaternary ammonium salt Examples include cationic surfactants such as molds; nonionic surfactants described later. When the surfactant is used, the amount used is preferably 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.
When stirring the mixture, a commonly used mixing and stirring device such as an anchor blade can be used.
The solid content concentration of the obtained aqueous dispersion containing the resin is preferably 3 to 50%, more preferably 5 to 30%, and still more preferably 7 to 15%.

Moreover, it can also be set as a dispersion liquid, without using an organic solvent. This is because when the resin is mixed with a nonionic surfactant, the viscosity of the resulting mixture decreases, and the decrease in the viscosity of the mixture is compatible with the nonionic surfactant, This is because the softening point of the resin apparently decreases. By utilizing this phenomenon, the apparent softening point of a resin compatible with a nonionic surfactant can be lowered to the boiling point of water or less, and even a resin having a melting point or softening point of 100 ° C. or higher by itself. By dropping water at normal pressure, a dispersion in which the resin is dispersed in water can be obtained.
This method requires at least water and a nonionic surfactant, so it can be applied to resins that are insoluble in organic solvents, and does not require the burden of equipment for recovering organic solvents and maintaining the work environment. Since a special device required when using mechanical means is not required, there is an advantage that a resin particle dispersion can be produced economically.

  Examples of the nonionic surfactant include polyoxyethylene alkylaryl ethers such as polyoxyethylene nonylphenyl ether; polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene lauryl ether; polyoxy Polyoxyethylene sorbitan esters such as ethylene sorbitan monolaurate and polyoxyethylene sorbitan monostearate; polyoxyethylene fatty acids such as polyethylene glycol monolaurate, polyethylene glycol monostearate, and polyethylene glycol monooleate Examples of esters include oxyethylene / oxypropylene block copolymers. In addition, an anionic surfactant or a cationic surfactant may be used in combination with the nonionic surfactant.

  As the nonionic surfactant, it is preferable to select a nonionic surfactant having good compatibility with the resin. In order to obtain a stable resin dispersion, the HLB of the nonionic surfactant is preferably 12 to 18, and two or more different HLB nonionic surfactants are used depending on the type of resin. It is more preferable. For example, in the case of a highly hydrophilic resin, at least one nonionic surfactant having an HLB of 12 to 18 may be used. In the case of a highly hydrophobic resin, a low HLB, for example, 7 to 10 is used. It is preferable to adjust the weighted average of both HLBs to 12 to 18 by using those having the same level and those having a high HLB, for example, 14 to 20 in combination. In this case, it is presumed that those having an HLB of about 7 to 10 can compatibilize the resin, and those having a high HLB can stabilize the dispersion of the resin in water.

The clouding point of the nonionic surfactant is preferably 70 to 105 ° C, more preferably 80 to 105 ° C when the resin is atomized under normal pressure and water.
The amount of the nonionic surfactant used is preferably 5 parts by weight or more with respect to 100 parts by weight of the crystalline resin or amorphous resin from the viewpoint of lowering the melting point of the resin, and the nonionic surfactant remaining in the toner. From the viewpoint of controlling the agent, 80 parts by weight or less is preferable. Therefore, from the viewpoint of making these compatible, the amount of the nonionic surfactant used is preferably 5 to 80 parts by weight and more preferably 10 to 70 parts by weight with respect to 100 parts by weight of the crystalline resin or amorphous resin. It is preferably 20 to 60 parts by weight.
The average particle diameter of the crystalline resin particles in the aqueous dispersion containing the crystalline resin and the volume median particle diameter of the amorphous resin particles in the aqueous dispersion containing the amorphous resin are uniformly aggregated in Step 2 From a viewpoint of making it, 0.05-2 micrometers is preferable, 0.05-1 micrometer is more preferable, 0.05-0.8 micrometer is further more preferable.
The coefficient of variation (CV value) in the particle size distribution of the crystalline resin particles in the aqueous dispersion is preferably 50% or less, more preferably from the viewpoint of low-temperature fixability of the toner, image fogging, and image glossiness. It is 35% or less, more preferably 28% or less. The variation coefficient (CV value) of the particle size distribution of the amorphous resin particles in the aqueous dispersion is preferably 50% or less, more preferably 35% or less, and still more preferably 28% or less, from the same viewpoint as described above. The lower limit is preferably 5% or more from the viewpoint of ease of production.

<Process 2>
In step 2, the aqueous dispersion containing the crystalline resin obtained in step 1 and the aqueous dispersion containing the amorphous resin are mixed and then subjected to an agglomeration step to aggregate the binder resin in the aqueous dispersion. This is a step of obtaining an aqueous dispersion of resin particles, that is, aggregated particles. Further, in step 2, for example, additives such as a colorant, a charge control agent, a release agent, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, and an anti-aging agent are added. May be. The additive can also be used as an aqueous dispersion.

  There is no restriction | limiting in particular as a coloring agent, A well-known coloring agent is mentioned, According to the objective, it can select suitably. Specifically, carbon black, inorganic composite oxide, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, Brilliantamine 6B, DuPont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, etc. Various pigments: acridine, xanthene, azo, benzoquinone, azine, anthraquinone, indico, Indigo dyes, phthalocyanine, aniline black, can be polymethine dyes, triphenylmethane dyes, diphenylmethane dyes, used singly or in combination of two or more of the thiazine, and various dyes thiazole like. The content of the colorant is preferably 0.1 to 20 parts by weight and more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  Examples of charge control agents include chromium azo dyes, iron azo dyes, aluminum azo dyes, and salicylic acid metal complexes. Various charge control agents may be used alone or in combination of two or more. The content of the charge control agent is preferably 0.1 to 8 parts by weight and more preferably 0.5 to 7 parts by weight with respect to 100 parts by weight of the binder resin.

As release agents, fatty acid amides such as oleic amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide; plant waxes such as carnauba wax, rice wax, candelilla wax, wood wax, and jojoba oil; Animal waxes such as beeswax; Waxes of mineral and petroleum waxes such as montan wax, ozokerite, ceresin, microcrystalline wax, and Fischer-Tropsch wax; polyolefin wax, paraffin wax, silicones, etc. Good. The melting point of the release agent is preferably 60 to 140 ° C., more preferably 60 to 100 ° C., from the viewpoints of low-temperature fixability and offset resistance. You may use a mold release agent 1 type or in combination of 2 or more types.
The content of the release agent is preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of dispersibility in the binder resin. More preferably, it is 5 to 7 parts by weight.
A preferable mixing weight ratio of the crystalline resin and the amorphous resin obtained in step 1 is the same as the weight ratio shown in the above description regarding the binder resin for toner.
In the aggregation step, the solid content concentration in the system is preferably 5 to 50% by weight, more preferably 5 to 30% by weight, and further preferably 5 to 20% by weight in order to cause uniform aggregation.

The pH in the system in the aggregation step is preferably 2 to 10, more preferably 2 to 9, and even more preferably 3 to 8, from the viewpoint of achieving both the dispersion stability of the mixed solution and the aggregation property of the resin particles.
From the same viewpoint, the temperature in the system in the aggregation step is preferably “softening point of binder resin−60 ° C.” (temperature lower by 60 ° C. than the softening point, the same shall apply hereinafter) or more and softening point or less. In the present invention, since a crystalline resin and an amorphous resin are used as the binder resin, the softening point of the mixed resin obtained by mixing and melting them is defined as the softening point of the binder resin (hereinafter the same). Is). Moreover, when using a masterbatch, it is set as the softening point of mixed resin including the resin used for it.

In addition, additives such as a colorant and a charge control agent may be mixed in advance with a crystalline resin or an amorphous resin when preparing resin particles, and each additive is separately dispersed in a dispersion medium such as water. A dispersion liquid prepared may be prepared, mixed with resin particles, and subjected to an aggregation step. When the additive is added to the crystalline resin or amorphous resin in advance when preparing the resin particles, it is preferable to melt and knead the crystalline resin or amorphous resin and the additive in advance.
For melt kneading, it is preferable to use an open roll type biaxial kneader. The open roll type twin-screw kneader is a kneader in which two rolls are arranged close to each other in parallel, and a heating function or a cooling function can be imparted by passing a heat medium through each roll. Therefore, the open roll type twin screw kneader is an open type part to be melt kneaded, and is provided with a heating roll and a cooling roll. The heat of kneading generated can be easily dissipated.

In the aggregation process, an aggregating agent can be added in order to effectively perform aggregation. As the flocculant, a quaternary salt cationic surfactant, polyethyleneimine, and the like are used in the organic system, and an inorganic metal salt, an inorganic ammonium salt, a divalent or higher metal complex, and the like are used in the inorganic system. Examples of the inorganic metal salt include metal salts such as sodium sulfate, sodium chloride, calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; polyaluminum chloride, polyaluminum hydroxide, and Examples thereof include inorganic metal salt polymers such as calcium polysulfide. Examples of the inorganic ammonium salt include ammonium sulfate, ammonium chloride, and ammonium nitrate.
The amount of the flocculant used is preferably 60 parts by weight or less, more preferably 55 parts by weight or less, and even more preferably 50 parts by weight or less with respect to 100 parts by weight of the binder resin from the viewpoint of environmental resistance characteristics of the toner.
The flocculant is preferably added after being dissolved in an aqueous medium, and is preferably sufficiently stirred at the time of addition of the flocculant and after completion of the addition.

In step 2, from the viewpoint of uniformly dispersing a mixture of the crystalline resin aqueous dispersion and the amorphous resin aqueous dispersion and various additives used as necessary, it is preferably less than the softening point of the binder resin. Dispersion processing is performed at the temperature. A uniform resin dispersion can be prepared by a dispersion treatment preferably at a temperature lower than the softening point of the binder resin, more preferably at a temperature of “the softening point −50 ° C.” or lower. The lower limit temperature of the dispersion treatment is preferably higher than 0 ° C., more preferably 10 ° C. or higher, from the viewpoint of fluidity of the medium and production energy of the resin emulsion.
Specifically, in a basic aqueous medium containing a surfactant, for example, resin particles having an acid group such as a resin, together with additives such as a colorant, are below the softening point of the resin particles, for example, about 10 to 50 ° C. A uniform resin dispersion can be prepared by an ordinary method such as stirring at a temperature of 5 ° C. for dispersion treatment.

As a dispersion method, ultra disperser (made by Asada Tekko Co., Ltd., trade name), Ebara Milder (made by Ebara Seisakusho Co., Ltd., trade name), and TK homomixer (trade name, made by Primix Co., Ltd.) High pressure homogenizer (product name, manufactured by Izumi Food Machinery Co., Ltd.), homovalve type high pressure homogenizer represented by Minilab 8.3H type (product name, Rannie); microfluidizer (product name, manufactured by Microfluidics), And a chamber type high pressure homogenizer such as Nanomizer (trade name, manufactured by Nanomizer Co., Ltd.).
The total amount of the aqueous medium in the step 2 is preferably 100 to 3000 parts by weight with respect to 100 parts by weight of the total amount of the crystalline resin and the amorphous resin, from the viewpoint of obtaining uniform aggregated particles in the subsequent steps, 3000 parts by weight are more preferable, and 800 to 3000 parts by weight are more preferable.

The volume-median particle size of the aggregated particles is preferably 1 to 10 μm, more preferably 2 to 8 μm, and even more preferably 3 to 7 μm from the viewpoint of uniformly uniting in the subsequent steps to produce toner particles.
In the present invention, the volume-median particle size of each particle can be measured with a laser diffraction particle size analyzer or the like.

<Process 3>
Step 3 adds the aggregation terminator to the aqueous dispersion of aggregated particles obtained in Step 2 as necessary, and then applies the coalescing step to unite the aggregated particles in the aqueous dispersion, This is a step of obtaining an aqueous dispersion of resin particles, that is, coalesced particles.
In the coalescence step of step 3, the aggregated particles obtained in step 2 are heated and coalesced.
The temperature in the system in the coalescence process is not less than “softening point of binder resin—30 ° C.” or more from the viewpoint of the target toner particle size, particle size distribution, shape control, and particle fusing property. Point + 10 ° C "or lower, more preferably" the softening point -25 ° C "or higher, more preferably" softening point + 10 ° C "or lower," the softening point -20 ° C "or higher, and" the softening point + 10 ° C "or lower. preferable. The stirring speed is preferably a speed at which the aggregated particles do not settle.
In addition, when using an aggregation terminator, it is preferable to use a surfactant as the aggregation terminator, and it is more preferable to use an anionic surfactant. Of the anionic surfactants, it is more preferable to use at least one selected from the group consisting of alkyl ether sulfates, alkyl sulfates, and linear alkylbenzene sulfonates.

(Manufacture of core-shell particles)
In the present invention, an electrophotographic toner including a “core-shell particle” as a binder resin in which the core portion includes the crystalline resin and the amorphous resin and the shell portion is the amorphous resin is also preferable. The core part is preferably a resin obtained by subjecting an aqueous dispersion containing an aqueous dispersion containing the crystalline resin and an aqueous dispersion containing the amorphous resin to an aggregation step.
The electrophotographic toner including the core-shell particles is provided with a step of mixing and aggregating an aqueous dispersion containing an amorphous resin to the aqueous dispersion of aggregated particles obtained in Step 2 before Step 3 described above. Can be obtained. Specifically, it can be obtained by a production method including the following steps 1 ′ to 3 ′.

Step 1 ′: A crystalline resin comprising a composite resin containing a condensation polymerization resin obtained by condensation polymerization of an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component and a styrene resin. A step of obtaining an aqueous dispersion of aggregated particles A by mixing an aqueous dispersion containing an aqueous dispersion containing an amorphous resin and subjecting to an aggregation step.
Step 2 ′: A step of obtaining an aqueous dispersion of aggregated particles B by mixing the aqueous dispersion of aggregated particles A obtained in Step 1 ′ with an aqueous dispersion containing an amorphous resin and subjecting to an aggregation step. .
Step 3 ′: A step of obtaining an aqueous dispersion of coalesced particles by subjecting the aqueous dispersion of aggregated particles B obtained in Step 2 ′ to the coalescence step.
By this method, core-shell particles in which the core part is made of a resin containing a crystalline resin and an amorphous resin and the shell part is an amorphous resin can be produced. By using an amorphous resin for the shell portion, it is possible to reduce the fog of the image and obtain a high glossiness while further improving the low-temperature fixability of the toner. In addition, as long as the effect of this invention is not lost, other resin, such as said crystalline resin, may be contained in the shell part.

Step 1 ′ is the same as Step 1 and Step 2 described above. The coefficient of variation (CV value) in the particle size distribution of the crystalline resin particles used in step 1 ′ is preferably 50% or less, more preferably 35 from the viewpoints of low-temperature fixability of the toner, image fog and image gloss. % Or less, more preferably 28% or less. The preferred range of the coefficient of variation (CV value) in the particle size distribution of the amorphous resin particles is the same as described above. From the same viewpoint as described above, it is preferably 50% or less, more preferably 35% or less, and still more preferably 28% or less. The lower limit is preferably 5% or more from the viewpoint of ease of production.
The volume-median particle size of the aggregated particles A obtained in step 1 ′ is preferably 0.8 to 9.8 μm, more preferably 1.8 to 7.8 μm, from the viewpoint of uniformly forming the shell portion in the subsequent step. Preferably, 2.8 to 6.8 μm is more preferable.
In step 2 ′, the aqueous dispersion of the aggregated particles A obtained in step 1 ′ and the aqueous dispersion containing the amorphous resin are mixed, and the amorphous resin is aggregated on the outer periphery of the aggregated particles A. In this step, an aqueous dispersion of particles B is obtained. The aqueous dispersion containing the amorphous resin to be mixed may be the same as or different from that used for the core part. From the viewpoint of producing uniform core-shell particles, the volume-median particle size of the amorphous resin particles is preferably 0.8 to 9.8 μm, more preferably 1.8 to 7.8 μm, and 2.8 to 6 More preferably, it is 8 μm.

The amorphous resin to be mixed is preferably 10 to 300 parts by weight and more preferably 20 to 100 parts by weight with respect to 100 parts by weight of the crystalline resin in the aggregated particles A obtained in step 1 ′. Moreover, 5-100 weight part is preferable with respect to 100 weight part of amorphous resin in the aggregated particle A obtained by process 1 ', and 10-80 weight part is preferable.
The volume median particle size of the aggregated particles B obtained in step 2 ′ is preferably 1 to 10 μm, more preferably 2 to 8 μm, from the viewpoint of producing toner particles by uniformly uniting them in the subsequent step 3 ′. More preferably, it is ˜7 μm.
Aggregation conditions are the same as in step 2 described above. Step 3 ′ is the same as Step 3 described above.
The preferred weight ratio between the crystalline resin and the amorphous resin in the core part of the core-shell particle and in the core-shell particle (core part + shell part) is the same as the crystalline resin and the amorphous resin in the binder resin described above. It is the same as the weight ratio with the quality resin. The weight of the shell part relative to 100 parts by weight of the core-shell particles (core part + shell part) is preferably 10 to 70 parts by weight, more preferably 15 to 50 parts by weight, from the viewpoint of low-temperature fixability of the toner and image fogging. More preferably, it is 20 to 40 parts by weight.

(Manufacture of toner)
The electrophotographic toner of the present invention can be obtained by subjecting the coalesced particles obtained in step 3 or step 3 ′ to a solid-liquid separation step such as filtration, a washing step, and a drying step as appropriate.
In the washing step, it is preferable to use an acid in order to remove metal ions on the surface of the toner in order to ensure sufficient charging characteristics and reliability as the toner. Further, it is preferable to completely remove the added nonionic surfactant by washing, and washing with an aqueous solution below the cloud point of the nonionic surfactant is preferred. The washing is preferably performed a plurality of times.
In the drying step, any method such as a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like can be employed. The water content after drying of the toner is preferably adjusted to 1.5% by weight or less, more preferably 1.0% by weight or less, from the viewpoint of chargeability.

[Electrophotographic toner]
The volume median particle size of the electrophotographic toner of the present invention is preferably from 1 to 10 μm, more preferably from 2 to 8 μm, and even more preferably from 3 to 7 μm, from the viewpoint of high image quality and productivity of the toner.
Further, the softening point of the toner is preferably 80 to 160 ° C., more preferably 80 to 150 ° C., and further preferably 90 to 140 ° C. from the viewpoint of low-temperature fixability. Further, the glass transition temperature of the toner is preferably 45 to 80 ° C., more preferably 50 to 70 ° C. from the same viewpoint as described above.

An auxiliary agent such as a fluidizing agent may be added to the toner particle surface as an external additive to the toner obtained by the present invention. Examples of the external additive include silica fine particles whose surface is hydrophobized, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, and inorganic fine particles such as carbon black; polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin, and the like. Fine particles can be used.
The number average particle diameter of the external additive is preferably 4 to 200 nm, more preferably 8 to 30 nm. The number average particle diameter of the external additive is determined using a scanning electron microscope or a transmission electron microscope.

When the external additive is added, the addition amount is 0.8 to 100 parts by weight with respect to 100 parts by weight of the toner before the processing with the external additive, from the viewpoint of low-temperature fixability of the toner, image fogging and image gloss. 5 parts by weight is preferred, 1 to 5 parts by weight is more preferred, and 1.5 to 3.5 parts by weight is even more preferred. However, when hydrophobic silica is used as the external additive, 0.8 to 3.5 parts by weight, preferably 1 to 3 parts by weight of hydrophobic silica is used with respect to 100 parts by weight of the toner before processing with the external additive. By using this, the desired effect can be obtained.
The electrophotographic toner of the present invention can be used as a one-component developer or a two-component developer mixed with a carrier.

[Measurement of resin]
Softening point of resin obtained by each production example, maximum endothermic peak temperature, melting point, crystallinity index, glass transition temperature and acid value, number average molecular weight, number average molecular weight of styrene resin component, volume of each particle The measurement of the unit particle size (D ₅₀ ) and the calculation of the CV value were performed as follows.
(Softening point of resin)
Using a flow tester (manufactured by Shimadzu Corporation, “CFT-500D”), a 1 g sample was heated at a rate of temperature increase of 6 ° C./min. Extruded from a 1 mm nozzle. The amount of plunger drop of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.
(Maximum endothermic peak temperature, melting point, crystallinity index)
Using a differential scanning calorimeter (manufactured by TA Instruments Japan, “Q-100”), the sample cooled from room temperature to 0 ° C. at a temperature lowering rate of 10 ° C./min is allowed to stand still for 1 minute. The temperature was measured up to 150 ° C. at a temperature rising rate of 10 ° C./min. Among the observed endothermic peaks, the temperature of the peak at the highest temperature side was defined as the highest endothermic peak temperature, and if the maximum peak temperature was within 20 ° C. from the softening point, the crystalline resin was defined as its melting point.
The crystallinity index was calculated by dividing the softening point by the maximum endothermic peak temperature.

(Glass transition temperature of crystalline resin (composite resin))
Using a differential scanning calorimeter (manufactured by TA Instruments Japan, "Q-100"), 0.01 to 0.02 g of the sample was weighed into an aluminum pan, and the temperature was raised to 200 ° C. A sample cooled from that temperature to −80 ° C. at a rate of temperature decrease of 100 ° C./min is heated in a modulated mode at a rate of temperature increase of 1 ° C./min. The temperature at the intersection with the tangent indicating the maximum slope from the portion to the peak apex was defined as the glass transition temperature.

(Glass transition temperature of amorphous resin)
Using a differential scanning calorimeter (manufactured by TA Instruments Japan, "Q-100"), 0.01 to 0.02 g of the sample was weighed into an aluminum pan, and the temperature was raised to 200 ° C. The sample cooled from the temperature to 0 ° C. at a rate of temperature decrease of 10 ° C./min is heated at a rate of temperature increase of 10 ° C./min. The temperature at the point of intersection with the tangent indicating the maximum slope until was taken as the glass transition temperature.
(Resin acid value)
It measured based on the method of JISK0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K 0070 to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

(Number average molecular weight of amorphous resin)
The molecular weight distribution was measured by the gel permeation chromatography (GPC) method according to the following method to determine the number average molecular weight of the resin.
(1) Preparation of sample solution Polyester is dissolved in tetrahydrofuran (THF) so that the concentration is 0.04 g / 10 ml. Subsequently, this solution was filtered using a fluororesin filter having a mesh of 0.45 μm (manufactured by Advantech Co., Ltd., “DISMIC-25JP”) to remove insoluble components to obtain a sample solution.
(2) Molecular weight measurement Using the following apparatus, THF was flowed at a flow rate of 1 ml / min, and the column was stabilized in a constant temperature bath at 40 ° C. Measurement was performed by injecting 100 μl of the sample solution. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. For the calibration curve at this time, several types of monodisperse polystyrene prepared as standard samples were used.
Measuring device: HLC-8220 GPC (manufactured by Tosoh Corporation)
Analytical column: GMH _XL + G3000H _XL (manufactured by Tosoh Corporation)
(Number average molecular weight of crystalline resin)
The measurement was performed in the same manner as for the amorphous resin except that the solvent was changed from THF to chloroform.

(Number average molecular weight of styrene resin component)
The molecular weight distribution was measured by the gel permeation chromatography (GPC) method according to the following method to determine the number average molecular weight of the styrene resin component.
(1) Preparation of sample solution The resin is dissolved in tetrahydrofuran (THF) so that the concentration is 0.04 g / 10 mL. Next, this solution was filtered using a fluororesin filter having a mesh of 0.45 μm (manufactured by Advantech Co., Ltd., “DISMIC-25JP”) to remove insoluble components to obtain a sample solution.
(2) Molecular weight measurement Using the following apparatus and analytical column, THF was flowed as an eluent at a flow rate of 1 mL per minute, and the column was stabilized in a constant temperature bath at 40 ° C. Measurement was performed by injecting 100 μL of the sample solution. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. There are several types of monodisperse polystyrene (A-500 (5.0 × 10 ² ), A-1000 (1.01 × 10 ³ ), A-2500 (2.63 × 10 ³ ), A -5000 (5.97 × 10 ³ ), F-1 (1.02 × 10 ⁴ ), F-2 (1.81 × 10 ⁴ ), F-4 (3.97 × 10 ⁴ ), F-10 (9.64 × 10 ⁴ ), F -20 (1.90 × 10 ⁵ ), F-40 (4.27 × 10 ⁵ ), F-80 (7.06 × 10 ⁵ ), F-128 (1.09 × 10 ⁶ )) prepared as standard samples were used.
Measuring device: HLC-8220 GPC (manufactured by Tosoh Corporation)
Analytical column: GMH _XL + G3000H _XL (manufactured by Tosoh Corporation)
The GPC analysis of the styrene resin component in the resin production example used a sample of the reaction solution after aging for 1 hour after completion of the addition of the addition polymerization resin monomer during preparation of the composite resin. For the GPC analysis of the styrene resin component in the obtained composite resin, a product hydrolyzed under the following conditions can be used.
In any of the above methods, since the raw material monomer of the condensation polymerization resin is included during the GPC measurement of the styrene resin component, when the number average molecular weight of the addition polymerization resin is obtained, the condensation polymerization resin is used. This is obtained by cutting the peak of the raw material monomer.

-Hydrolysis conditions-
1 g of composite resin, 20 g of 0.5N ethanolic potassium hydroxide and 20 g of ion-exchanged water are placed in an eggplant flask equipped with a 100 mL air-cooled condenser, and hydrolyzed in an oil bath at 95 to 99 ° C. for 24 hours. Subsequently, a small amount of phenolphthalein is added, and then neutralized with 0.5N hydrochloric acid until the liquid becomes transparent. Finally, the neutralized solution is removed using an evaporator under conditions of 60 ° C. under reduced pressure (40 kPa), and only the precipitate is dried to obtain a mixture of a hydrolyzate of a styrene resin and a condensation polymerization resin.

(Volume Median Particle Size (D ₅₀ ) of Resin Particles, Colorant Fine Particles, Release Agent Fine Particles, and Charge Control Agent Fine Particles)
Laser diffraction-type particle size measuring instrument (Horiba Ltd., Ltd., "LA-920") using a distilled water was added to the measuring cell, a volume-median particle size in a concentration at which the absorbance is within a proper range (D ₅₀₎ Was measured. The CV value was calculated according to the following formula. A lower CV value of the resin particles in the aqueous dispersion indicates that the particle diameters are uniform.
CV value (%) = (standard deviation of particle size distribution / volume median particle size (D ₅₀ )) × 100

Production Examples 1 to 6 and 8 (Production of crystalline resins A to F and H)
The raw material monomer of the condensation polymerization resin component other than trimellitic anhydride in the blending amount shown in Table 1 is put into a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and 170 ° C. The mixture obtained by stirring and mixing the raw material monomer of styrene resin component, dicumyl peroxide and acrylic acid shown in Table 1 was added dropwise over 1 hour with a feed pump. After aging the addition polymerization reaction for 1 hour while maintaining at 170 ° C., the raw material monomer of the styrene resin component was removed at 8.3 kPa for 1 hour.
Thereafter, 40 g of tin octylate and 4 g of gallic acid were added, the temperature was raised to 180 ° C., the reaction was performed for 4 hours, and the temperature was further raised to 210 ° C. over 8 hours. Next, after the temperature was lowered to 180 ° C., trimellitic anhydride was added and reacted until the acid value reached about 24 to produce crystalline resins A to F and H.

Production Example 7 (Production of crystalline resin G)
Production Example 1 except that the temperature at which the mixed liquid obtained by stirring and mixing the raw material monomer of the styrenic resin component, dicumyl peroxide and acrylic acid was dropped and the aging temperature after dropping was 160 ° C. In the same manner as in Example 1, a crystalline resin G was produced.

Production Example 9 (Production of crystalline resin I)
The raw material monomer of the condensation polymerization resin component other than trimellitic anhydride in the blending amount shown in Table 2 was placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirring device and a thermocouple, and 170 ° C. The mixture obtained by stirring and mixing raw material monomers of styrene-based resin components shown in Table 2, dicumyl peroxide and acrylic acid was added dropwise over a period of 1 hour by a feed pump. After aging the addition polymerization reaction for 1 hour while maintaining at 170 ° C., the raw material monomer of the styrene resin component was removed at 8.3 kPa for 1 hour.
Thereafter, 40 g of tin octylate and 4 g of gallic acid were added, the temperature was raised to 175 ° C., the reaction was carried out for 10 hours, and the temperature was further raised to 200 ° C. over 10 hours. Next, after the temperature was lowered to 180 ° C., trimellitic anhydride was added and reacted until the acid value reached about 24 to produce crystalline resin I.

Production Example 10 (Production of crystalline resin J)
The raw material monomers of the polycondensation resin components other than trimellitic anhydride and terephthalic acid shown in Table 2 are placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. , Heated to 180 ° C. and allowed to react for 8 hours. Thereafter, terephthalic acid is added, and after adjusting the heating, the mixture is obtained by stirring and mixing the raw material monomer of styrene resin component, dicumyl peroxide and acrylic acid shown in Table 2 at 170 ° C. Was added dropwise over 1 hour. After aging the addition polymerization reaction for 1 hour while maintaining at 170 ° C., the raw material monomer of the styrene resin component was removed at 8.3 kPa for 1 hour.
Thereafter, 40 g of tin octylate and 4 g of gallic acid were added, the temperature was raised to 180 ° C., the reaction was performed for 4 hours, and the temperature was further raised to 210 ° C. over 8 hours. Next, after the temperature was lowered to 180 ° C., trimellitic anhydride was added and reacted until the acid value reached about 24 to produce crystalline resin J.

Production Examples 11 and 12 (Production of crystalline resins K and L)
The alcohol component of the blending amount shown in Table 2 is put into a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, heated to 170 ° C., and the styrenic resin component shown in Table 2 A mixture obtained by stirring and mixing the raw material monomer, dicumyl peroxide and acrylic acid was added dropwise over a period of 1 hour using a liquid feed pump. While maintaining at 170 ° C., the addition polymerization reaction was aged for 1 hour. Thereafter, the temperature is lowered to 140 ° C., fumaric acid or sebacic acid and 4 g of tertiary butyl catechol are added, the reaction is carried out at 180 ° C. for 10 hours, and trimellitic anhydride is further added, so that the acid value becomes about 24. To produce crystalline resins K and L.

Comparative Production Examples 1 and 2 (Production of crystalline resins M and N)
Raw materials other than trimellitic anhydride shown in Table 2, 40 g of tin octylate and 4 g of gallic acid were placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple at 180 ° C. After making it react over 4 hours, it heated up to 210 degreeC over 8 hours. The temperature was lowered to 180 ° C., trimellitic anhydride was added, and the reaction was continued until the acid value reached about 24 to produce crystalline resins M and N.

  In Table 1, the number average molecular weight of the crystalline resin may be smaller than the number average molecular weight of the styrene resin component because there is a low molecular weight crystalline resin not containing the styrene resin component. .

Production Example 13 (Production of Amorphous Resin AA)
Raw materials other than trimellitic anhydride shown in Table 3, 40 g of tin octylate and 2 g of gallic acid were placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple at 230 ° C. After making it react over 8 hours, it was made to react at 8.3 kPa for 1 hour. Furthermore, trimellitic anhydride was added at 210 ° C. and reacted at 210 ° C. at 8 kPa until the softening point was reached to produce amorphous resin AA.

Production Example 14 (Production of amorphous resin AB)
Raw materials other than trimellitic anhydride and fumaric acid shown in Table 3 and 40 g of tin octylate were placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and 8 ° C. at 230 ° C. After reacting over time, it was reacted at 8.3 kPa for 1 hour. Further, fumaric acid, tertiary butyl catechol 3 g and trimellitic anhydride were added at 180 ° C., the temperature was raised to 210 ° C. over 4 hours, and the reaction was continued until the softening point was reached, thereby producing amorphous resin AB.

Production Example 15 (Production of amorphous resin AC)
A raw material other than trimellitic anhydride shown in Table 3, 40 g of tin octylate and 2 g of gallic acid, a dehydration tube equipped with a rectifying tower through which hot water of 100 ° C. was passed, a nitrogen introduction tube, a stirring device, and a thermocouple It put into the equipped 5 L four-necked flask, was made to react from 180 degreeC to 230 degreeC over 8 hours, Then, it was made to react at 8.3 kPa for 1 hour. Further, trimellitic anhydride was added and reacted at 220 ° C. at 40 kPa until the softening point was reached to produce amorphous resin AC.

[Production example of dispersion]
Production Examples 16 to 27, Comparative Production Examples 3 and 4 (Preparation of aqueous dispersion of crystalline resin)
In a 5 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer and nitrogen introduction tube, 600 g of ethyl acetate, “Kao Akypo RLM-100” as an anionic surfactant (component: polyoxyethylene lauryl ether acetic acid, 6 g of Kao Corporation), 0.5 g of potassium hydroxide and 28 g of ion-exchanged water were added, and 200 g of the crystalline resin produced in Production Examples 1-12 or Comparative Production Examples 1 and 2 was added at 70 ° C., Dissolved.
The resulting solution was neutralized by adding 21.6 g (about 0.9 equivalent) of a 20% aqueous potassium hydroxide solution, followed by addition of 2000 g of ion-exchanged water, followed by reducing the pressure at a stirring speed of 250 r / min. Then, ethyl acetate was distilled off at a temperature of 50 ° C. or lower to obtain an aqueous dispersion of a self-dispersing crystalline resin (crystalline resin content: 9.6% by weight (in terms of solid content)).
Tables 4 and 5 show the volume-median particle size and CV value of the crystalline resin particles in the obtained aqueous dispersion.

Production Examples 28 to 30 (Preparation of aqueous dispersion of amorphous resin)
In a 5 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer and nitrogen introduction tube, 600 g of ethyl acetate and “Kao Akypo RLM-100” as an anionic surfactant (component: polyoxyethylene lauryl ether acetic acid, 6 g of Kao Corporation) was added, and 200 g of the amorphous resin produced in Production Examples 13 to 15 was added at 50 ° C. and dissolved.
The resulting solution was neutralized by adding 0.9 equivalent of potassium hydroxide, followed by addition of 2000 g of ion-exchanged water, followed by acetic acid at a temperature of 50 ° C. or lower under reduced pressure at a stirring speed of 250 r / min. Ethyl was distilled off to obtain an aqueous dispersion of a self-dispersing amorphous resin (amorphous resin content: 9.6% by weight (in terms of solid content)).
Table 6 shows the volume median particle size and CV value of the amorphous resin particles in the obtained aqueous dispersion.

(Preparation of colorant dispersion)
50 g of copper phthalocyanine (manufactured by Dainichi Seika Kogyo Co., Ltd., model number: ECB-301), 5 g of nonionic surfactant (Emulgen (registered trademark) 150, manufactured by Kao Corporation) and 200 g of ion-exchanged water are mixed, and copper phthalocyanine is mixed. Dissolved and dispersed for 10 minutes using a homogenizer to obtain a colorant dispersion containing fine colorant particles. The volume median particle size of the colorant fine particles was 120 nm.

(Preparation of release agent dispersion)
Paraffin wax (HNP0190, manufactured by Nippon Seiwa Co., Ltd., melting point: 85 ° C.) 50 g, cationic surfactant (Sanisol (registered trademark) B50, manufactured by Kao Corporation) 5 g and ion-exchanged water 200 g were heated to 95 ° C. Then, the paraffin wax was dispersed using a homogenizer and then dispersed with a pressure discharge type homogenizer to obtain a release agent dispersion liquid containing release agent fine particles. The volume median particle size of the release agent fine particles was 550 nm.

(Preparation of charge control agent dispersion)
Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) 50 g, nonionic surfactant (Emulgen (registered trademark) 150, manufactured by Kao Corporation) 5 g and ion-exchanged water 200 g are mixed, and glass beads are used. Then, the mixture was dispersed for 10 minutes using a sand grinder to obtain a charge control agent dispersion liquid containing charge control agent fine particles. The volume median particle size of the charge control agent fine particles was 500 nm.

[Measurement and evaluation of toner]
Measurement of the volume median particle size (D ₅₀ ) of the toners obtained in the following Examples and Comparative Examples and evaluation of the low-temperature fixability of the toner, the fogging of the image and the glossiness of the image were performed as follows. .

(Volume-median particle diameter of toner (D ₅₀ ))
(1) Preparation of dispersion: 10 mg of a measurement sample was added to 5 ml of a surfactant ["Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) 5 wt% aqueous solution]. Disperse for 1 minute with an ultrasonic disperser, and then add 25 ml of electrolyte [“Isoton II” (manufactured by Beckman Coulter, Inc.)] and further disperse for 1 minute with an ultrasonic disperser. Obtained.
(2) Measuring device: “Coulter Multisizer II” (manufactured by Beckman Coulter, Inc.)
Aperture diameter: 100 μm
Measurement particle size range: 2-40 μm
Analysis software: “Coulter Multisizer AccuComp Version 1.19” (Beckman Coulter, Inc.)
(3) Measurement conditions: 100 ml of electrolyte solution and the above dispersion were added to a beaker, and the volume-median particle size (D ₅₀ ) of 30,000 particles was measured at a concentration at which the particle size of 30,000 particles could be measured in 20 seconds. )

Examples 1 to 14 and Comparative Examples 1 and 2 (Production Method of Toners a to p)
210 g of the resin dispersion prepared according to the above Production Examples 16 to 30 and Comparative Production Examples 3 and 4 were prepared at a ratio shown in Table 7 or 8, 8 g of the colorant dispersion, 6 g of the release agent dispersion, and the charge control agent. 2 g of the dispersion and 52 g of deionized water were placed in a 2 L container, and then 146 g of a 6.2 wt% aqueous ammonium sulfate solution was added dropwise at room temperature with stirring at 100 r / min with a chi-type stirrer over 30 minutes. Then, it heated up, stirring, when it became 50 degreeC, it fixed to 50 degreeC and hold | maintained for 3 hours. After forming aggregated particles in this manner, except for Example 2, 90 g of an aqueous dispersion of an amorphous resin for a shell part described in Table 7 or 8 was dropped over 1 hour, and then at 50 ° C. Hold for 1 hour. Thereafter, a dilute solution obtained by diluting 4.2 g of a polyoxyethylene dodecyl ether sodium sulfate aqueous solution (solid content 28% by weight) with 37 g of deionized water was added as an aggregation terminator.
Subsequently, the temperature was raised to 80 ° C. at 0.16 ° C./min, and after maintaining at 80 ° C. for 1 hour from the time when the temperature reached 80 ° C., the heating was terminated. Thus, coalesced particles were formed, and then gradually cooled to room temperature, and toner particles were obtained through a suction filtration step, a washing step, and a drying step.
0.3 parts by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., R972, number average particle size 16 nm) is added to the toner particles using a Henschel mixer, and cyan toner (toner a to p, volume median particle size: about 5.1 μm).

(Low-temperature fixability of toner)
The toners a to p manufactured in Examples 1 to 14 or Comparative Examples 1 and 2 were mounted on a copying machine “AR-505” (manufactured by Sharp Corporation), and images were printed without fixing (printing area). : 2 cm × 12 cm, adhesion amount: 0.5 mg / cm ² ).
The unfixed image was placed in a constant temperature bath at a specific temperature for 60 seconds, and then the fixing strength was measured. The temperature of the thermostatic chamber was examined by increasing the temperature from 70 ° C by 5 ° C. For the fixing paper, “CopyBond SF-70NA” (manufactured by Sharp Corporation, 75 g / m ² ) was used.
The fixing strength was measured by attaching “UNICEF Cellophane” (Mitsubishi Pencil Co., Ltd., width: 18 mm, JIS Z 1522) to the fixed image, passing it through a fixing roller set at 30 ° C., and then removing the tape. The optical reflection density before and after the tape was peeled was measured using a reflection densitometer “RD-915” (manufactured by Gretag Macbeth), and the ratio between the two (after peeling / before sticking) first exceeded 90%. The temperature of the thermostatic bath was set as the minimum fixing temperature, and the low temperature fixing property was evaluated according to the following evaluation criteria. The lower the minimum fixing temperature, the better the low temperature fixing property. The results are shown in Tables 7 and 8.
1: The minimum fixing temperature is less than 80 ° C.
2: The minimum fixing temperature is 80 ° C. or higher and lower than 90 ° C.
3: The minimum fixing temperature is 90 ° C. or higher and lower than 95 ° C.
4: The minimum fixing temperature is 95 ° C. or higher and lower than 100 ° C.
5: The minimum fixing temperature is 100 ° C. or higher.

(Image gloss)
The toners a to p manufactured in Examples 1 to 14 or Comparative Examples 1 and 2 were mounted on a copying machine “AR-505” (manufactured by Sharp Corporation), and images were printed without fixing (printing area). : 2 cm × 12 cm, adhesion amount: 0.5 mg / cm ² ). J paper (manufactured by Fuji Xerox) as the print medium. The fixing machine of the copying machine was fixed on paper at 160 ° C. and 400 mm / sec offline.
Using a gloss meter (“IG-330” manufactured by Horiba, Ltd.), a cardboard is laid under the image, and the glossiness is measured at a light irradiation condition of 60 °. The higher the value obtained, the higher the glossiness. The results are shown in Tables 7 and 8.

(Evaluation of image fog)
60 g of each of the toners a to p manufactured in Examples 1 to 14 or Comparative Examples 1 and 2 was mounted on a cyan toner cartridge of a machine from which a fixing device of “MicroLine 5400” (manufactured by Oki Data Co., Ltd.) was removed, and “Copy Bond” After printing 20 images with a printing rate of 5% against “SF-70NA” (manufactured by Sharp Corporation, 75 g / m ² ), ^two images with a printing rate of 0% were continuously printed.
After the printing of the second sheet is 10 cm to 20 cm above the paper, the machine is stopped, and “UNICEF cellophane” (manufactured by Mitsubishi Pencil Co., Ltd., width: 18 mm, JIS Z 1522) is attached to the photosensitive member part. The cellophane tape was peeled off and affixed to the surface of a new “CopyBond SF-70NA” (manufactured by Sharp Corporation, 75 g / m ² ).
Separately, a new UNICEF cellophane was attached to the paper surface.
L ^* a ^* b ^* was measured using a color difference meter “GRETAG-MCBETH AG CH-8105” (manufactured by Gretag Macbeth), and the fogging of the image on the photoreceptor was evaluated based on the amount of hue change of the following formula. The lower the hue change amount, the more the image fog is reduced. The results are shown in Tables 7 and 8.
Hue variation _{^{= √ ((a * 1 -a}} * 2) 2 + (b * 1 -b * 2) 2 + (L * 1 -L * 2) 2)
L ^* a ^* b ^* value of new UNICEF cellophane: L ^* ₁ , a ^* ₁ , b ^* ₁
L ^* a ^* b ^* values of UNICEF cellophane peeled from the photoconductor: L ^* ₂ , a ^* ₂ , b ^* ₂

  Toners a to n obtained by using an aqueous dispersion having excellent dispersibility of the crystalline resin are excellent in low-temperature fixability, have little image fogging, and are excellent in gloss. This is probably because the dispersion of the crystalline resin into the amorphous resin was excellent.

  The toner containing the binder resin of the present invention is excellent in low-temperature fixability, has little image fogging, and is excellent in gloss, and therefore can be suitably used as an electrophotographic toner.

Claims (11)

A binder resin for toner composed of a resin obtained by subjecting an aqueous dispersion containing a crystalline resin and an aqueous dispersion containing an amorphous resin to an aggregation step and a coalescence step, the crystalline resin comprising: A composite resin comprising a condensation polymerization resin component and a styrene resin component obtained by condensation polymerization of an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component,
The composite resin comprises (a) a raw material monomer of a polycondensation-based resin component containing an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component, (b) a raw material monomer of a styrene-based resin component, And (c) a binder resin for an electrophotographic toner, which is a resin obtained by polymerizing both reactive monomers capable of reacting with either a raw material monomer of a condensation polymerization resin component or a raw material monomer of a styrene resin component.   An electrophotographic toner binder resin comprising core-shell particles, wherein the binder resin according to claim 1 is a core portion and an amorphous resin is a shell portion. A binder resin for toner comprising core-shell particles having a core part and a shell part, wherein the core part includes a crystalline resin and an amorphous resin, and the crystalline resin is an aliphatic having 2 to 10 carbon atoms a composite resin containing a polycondensation resin component and the styrenic resin component obtained an alcohol component and a carboxylic acid component containing a diol by polycondensing, shell part I amorphous resin der,
The composite resin comprises (a) a raw material monomer of a polycondensation-based resin component containing an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component, (b) a raw material monomer of a styrene-based resin component, and (iii) the condensation polymerization with any resin der obtained by polymerizing a dually reactive monomer capable of reacting of the raw material monomer of the raw material monomer and styrenic resin component of the resin component Ru, electrophotographic toner binder resin.   The binder resin for electrophotographic toner according to claim 1, wherein a monovalent aliphatic alcohol or a monovalent aliphatic carboxylic acid is used in combination as a raw material monomer for the polycondensation resin component.   The binder resin for an electrophotographic toner according to any one of claims 1 to 4, wherein the amount of the both reactive monomers used is 2 to 25 moles with respect to a total of 100 moles of raw material monomers of the styrene resin component. .   The binder resin for an electrophotographic toner according to claim 5, wherein the amount of the both reactive monomers used is 6 to 13 mol with respect to 100 mol of the total amount of raw material monomers of the styrene resin component.   In the composite resin, the weight ratio of the condensation polymerization resin component to the styrene resin component (total amount of raw material monomers of the condensation polymerization resin component / total amount of raw material monomers of the styrene resin component) is 60/40 to 95/5. The binder resin for an electrophotographic toner according to any one of claims 1 to 6.   The binder resin for electrophotographic toner according to any one of claims 1 to 7, wherein an aliphatic diol having 2 to 10 carbon atoms is 70 mol% or more in an alcohol component which is a raw material of the condensation polymerization resin component.   The binder resin for an electrophotographic toner according to any one of claims 1 to 8, wherein the carboxylic acid component which is a raw material of the condensation polymerization resin component contains 60 to 99 mol% of an aromatic dicarboxylic acid compound.   An electrophotographic toner comprising the binder resin according to claim 1. The manufacturing method of the binder resin for electrophotographic toners which has the following processes 1-3.
Step 1: A composite resin comprising a condensation polymerization resin obtained by condensation polymerization of an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component, and a styrene resin , wherein the composite resin is (A) a raw material monomer of a polycondensation-based resin component comprising an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component, (b) a raw material monomer of a styrene-based resin component, and (c) An aqueous dispersion containing a crystalline resin comprising a resin obtained by polymerizing both reactive monomers capable of reacting with either a raw material monomer of a condensation polymerization resin component and a raw material monomer of a styrene resin component , and an amorphous resin A step of obtaining an aqueous dispersion containing
Step 2: The aqueous dispersion containing the crystalline resin obtained in Step 1 and the aqueous dispersion containing the amorphous resin are mixed and then subjected to an aggregation step to obtain an aqueous dispersion of resin particles (aggregated particles). Process.
Step 3: A step of obtaining an aqueous dispersion of resin particles (unified particles) by subjecting the aqueous dispersion of aggregated particles obtained in Step 2 to an unifying step.