JP2011138000A - Electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin for toner, binder resin for toner containing the polyester resin and electrophotographic toner containing the binder resin, which can improve charge buildup performance while maintaining low-temperature fixability, preservability and hot offset resistance of toner. <P>SOLUTION: The polyester resin for toner, binder resin for toner containing the polyester resin and electrophotographic toner containing the binder resin are achieved by condensation polymerization of at least any one of a reaction product of one or a plurality of aromatic compounds, carboxylic acid component and alcohol component, expressed by equation (I), where R<SP>1</SP>is a hydrogen atom, hydroxyl group or methoxy group and X is a hydroxyl group or carboxyl group that may contain a linking group. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyester resin for electrophotographic toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, a binder resin for toner containing the polyester resin, and The present invention relates to an electrophotographic toner containing the binder resin.

  In recent years, with an increase in machine speed and energy saving, a toner having excellent low-temperature fixability has been demanded. Therefore, many polyesters having excellent low-temperature fixability have been studied as binder resins for toners, and among them, a carboxyl having an aromatic ring that can improve the glass transition point while maintaining a low softening point. Polyester obtained by using an acid as a raw material monomer is used. However, a toner using such a polyester has a problem that the charge rising property is slow.

  In Patent Document 1, in an electrostatic charge image developing toner containing at least a binder resin, a wax, a colorant and a charge control agent, a metal complex of an aromatic oxycarboxylic acid is used as the charge control agent, and a third substance A toner for developing an electrostatic image is disclosed, which contains a hydroxylated aromatic oxycarboxylic acid compound.

  In Patent Document 2, an organic solvent is removed from a dispersion in which a solution or dispersion in which a toner material containing at least a binder resin and a charge control agent is dissolved or dispersed in an organic solvent is dispersed in an aqueous medium. The toner obtained by the above, wherein the binder resin has at least a functional group capable of ionic bonding, and the charge control agent is ionically bonded to the binder resin inside the toner. It is disclosed.

JP 2006-71970 A JP 2008-51873 A

  However, it is desired to further improve the charge rising property of the toner corresponding to the high-speed machine.

  An object of the present invention is to provide a polyester resin for toner capable of improving the charge rising property while maintaining low-temperature fixability, storage stability and hot offset resistance of the toner, and a binder for toner containing the polyester resin. An object of the present invention is to provide a resin and an electrophotographic toner containing the binder resin.

The present invention
[1] Formula (I):

(In the formula, R ¹ represents a hydrogen atom, a hydroxyl group or a methoxy group, and X represents a hydroxyl group or a carboxyl group which may have a linking group.)
A polyester-based resin for toner obtained by polycondensation of at least one of a reaction product of one or more aromatic compounds and a carboxylic acid component and an alcohol component represented by:
[2] A toner binder resin comprising the toner polyester resin according to [1], and [3] an electrophotographic toner comprising the toner binder resin according to [2]. It relates to toner.

  The electrophotographic toner containing the polyester-based resin for toner of the present invention has an excellent effect that the charge rising property can be improved while maintaining low-temperature fixability, storage stability, and hot offset resistance. It is.

  The polyester-based resin for toner of the present invention has a formula (I) in which a hydroxyl group and a methoxy group are bonded to an adjacent carbon atom and at least one of a carboxylic acid component and an alcohol component:

(In the formula, R ¹ represents a hydrogen atom, a hydroxyl group or a methoxy group, and X represents a hydroxyl group or a carboxyl group which may have a linking group.)
It is characterized in that it is a resin obtained by subjecting a reaction product of one or a plurality of aromatic compounds represented by

  The polyester-based resin for toner of the present invention is excellent in charge rising property while maintaining the low-temperature fixability, storage stability, and hot offset resistance of the toner, but the details of the reason are unclear but are used in the present invention. Since the reaction product of aromatic compounds has an aromatic ring, when used as a raw material for polyester, it is possible to increase the glass transition point while lowering the softening point. Furthermore, compared to conventional terephthalic acid and isophthalic acid, a methoxy group having an electron donating property and a hydroxyl group are bonded to adjacent carbon atoms in the aromatic ring, so that it has a high pKa (isoelectric point). It becomes a raw material having a hydroxyl group, and as a result of increasing the electron density in the aromatic ring, it is considered that the rising property of charging is improved. If the number of methoxy groups on the carbon atom adjacent to the carbon atom to which the hydroxyl group is bonded is at least one, the rising property of charging of the toner is improved, but two may be used. Further, the resin of the present invention also maintains hot offset resistance. This is because, by using a reaction product of the aromatic compounds, the reactivity of the polycondensation reaction of the aromatic compound is higher than that of the polycondensation reaction of the aromatic compound, and the polyester resin has a high molecular weight. It is presumed that the

In the present invention, the reaction between the aromatic compounds represented by the formula (I),
(i) a condensation reaction that occurs when the aromatic compound has a carboxyl group and a hydroxyl group;
(ii) an ether reaction that occurs when the aromatic compound has two or more hydroxyl groups;
(iii) An addition reaction that occurs when the aromatic compound has an unsaturated hydrocarbon group is included. In addition, a dicarboxylic acid compound or a trihydric or higher polyhydric alcohol compound can also be generated in the addition reaction. The aromatic compound may be reacted with only one kind of compound, or two or more kinds of compounds may be reacted simultaneously. Therefore, the reactions (i) to (iii) may occur simultaneously.

The linking group in X is preferably a divalent unsaturated hydrocarbon group having preferably 2 to 4, more preferably 2 or 3, carbon atoms. Specific examples of X include groups represented by —CH═CH—COOH, —CH═CH—CH ₂ OH, —COOH, and —OH.

As the aromatic compound represented by the formula (I), ferulic acid (X: —CH═CH—COOH, R ¹ : hydrogen atom), 5-hydroxyferulic acid (X: —CH) is used from the viewpoint of charge rising property. = CH-COOH, R ¹ : hydroxyl group, sinapinic acid (X: -CH = CH-COOH, R ¹ : methoxy group), syringic acid (X: -COOH, R ¹ : methoxy group), and vanillic acid (X At least one hydroxycarboxylic acid selected from the group consisting of: —COOH, R ¹ : hydroxyl group; coniferyl alcohol (X: —CH═CH—CH ₂ OH, R ¹ : hydrogen atom), 5-hydroxyconi And diols such as ferryl alcohol (X: —CH═CH—CH ₂ OH, R ¹ : hydroxyl group), and sinapyl alcohol (X: —CH═CH—CH ₂ OH, R ¹ : methoxy group). From the viewpoint of reactivity, Phosphate is preferable.

The molecular weight of the aromatic compound represented by the formula (I) is preferably 800 or less, more preferably 500 or less, further preferably 300 or less, and further preferably 250 or less, from the viewpoint of condensation polymerization reactivity. The lower limit is 140 when R ¹ is a hydrogen atom and X is a hydroxyl group.

  The reaction temperature when the aromatic compounds represented by the formula (I) are reacted with each other is preferably 140 ° C. to 210 ° C. from the viewpoint of the reactivity and the thermal stability of the aromatic compound represented by the formula (I). 150 to 180 ° C. is more preferable. As described above, when the aromatic compound represented by formula (I) has a carboxy group, the reaction is considered to cause a condensation reaction, and the aromatic compound represented by formula (I) has a carboxyl group. If not, etherification is considered to occur due to the reaction between the hydroxyl groups. Moreover, when it has an unsaturated hydrocarbon group as a coupling group in X, it is thought that addition reaction also arises.

  From the viewpoint of reactivity, in the aromatic compound represented by the formula (I), X preferably has an unsaturated hydrocarbon group as a linking group, and the functional group preferably has a carboxyl group.

  You may use a solvent suitably. The reaction time is preferably 2 to 20 hours, more preferably 5 to 13 hours.

  As the catalyst, an acid, an alkali, a metal catalyst described later, or the like may be appropriately used depending on the target reaction.

  The end point of the reaction can be determined based on the molecular weight measurement by GPC, which will be described later, having a weight average molecular weight equal to or higher than the molecular weight of the dehydrated polycondensation product (dimer) of the aromatic compound used. The weight average molecular weight of the reaction product obtained is preferably 350 to 2000, more preferably 400 to 1500, still more preferably 450 to 1000, and more preferably 450 to 800, from the viewpoint of the charge rising property and hot offset resistance of the toner. Further preferred.

  When the reaction product has an unsaturated hydrocarbon group as a condensation reaction or etherification of aromatic compounds represented by the formula (I) or a linking group, the reaction product contains those obtained by addition reaction as a main component it is conceivable that. In the present invention, by using the reaction product of the aromatic compounds represented by the formula (I), the reactivity in the polycondensation reaction with at least one of the carboxylic acid component and the alcohol component is increased. It is considered that the aromatic compound represented by I) can be efficiently incorporated into the molecular chain of the polyester.

  The polyester-based resin for toner of the present invention is obtained by polycondensation of the reaction product of the one or more aromatic compounds with at least one of a carboxylic acid component and an alcohol component. For example, when the reaction product of the aromatic compounds in which X is a carboxyl group is used, only the alcohol component may be used, and in the case of using the reaction product of the aromatic compounds in which X is a hydroxyl group, Only the carboxylic acid component may be used. From the viewpoint of improving the condensation polymerization reactivity and improving the storage stability of the toner, a toner obtained by condensation polymerization of the reaction product of the one or more aromatic compounds, the carboxylic acid component, and the alcohol component Polyester resins for use are preferred.

  As the alcohol component, the formula (II):

(Wherein R ² O and OR ² are oxyalkylene groups, R ² is an ethylene and / or propylene group, x and y indicate the number of moles of alkylene oxide added, each being a positive number, The average value of the sum of y and y is preferably 1 to 16, more preferably 1 to 8, and even more preferably 1.5 to 4)
An alkylene oxide adduct or aliphatic diol of bisphenol A represented by

  The alkylene oxide adduct of bisphenol A is preferable from the viewpoint of toner storage stability.

  Specific examples of the alkylene oxide adduct of bisphenol A represented by the formula (II) include 2,2-bis (4-hydroxyphenyl) propane polyoxypropylene adduct and 2,2-bis (4-hydroxy). And an alkylene oxide adduct of bisphenol A such as a polyoxyethylene adduct of phenyl) propane.

  The content of the alkylene oxide adduct of bisphenol A is preferably 20 to 100 mol%, more preferably 30 to 100 mol%, and still more preferably 50 to 100 mol% in the alcohol component from the viewpoint of toner storage stability. It is.

  An aliphatic diol, preferably an aliphatic diol having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, is preferable from the viewpoint of low-temperature fixability of the toner.

  Aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 1,4-butenediol, neopentyl glycol, 2,3-butanediol, 2,3-pentanediol, 2,4-pentanediol, 2,3-hexanediol, 3,4- Examples include hexanediol, 2,4-hexanediol, and 2,5-hexanediol.

  Among these, an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferable from the viewpoint of excellent low-temperature fixability and storage stability of the toner. Such aliphatic diols preferably have 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms, from the viewpoint of low-temperature fixability and storage stability. Specific preferred examples include 1,2-propanediol, 1, Examples include 2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 2,3-pentanediol, and 2,4-pentanediol. .

  The content of the aliphatic diol is preferably 20 to 100 mol%, more preferably 30 to 100 mol%, and still more preferably 50 to 100 mol% in the alcohol component from the viewpoint of low-temperature fixability of the toner.

  As other alcohols, trivalent or higher alcohols such as glycerin, pentaerythritol, and trimethylolpropane may be used.

  As the carboxylic acid component, an aromatic dicarboxylic acid compound or an aliphatic dicarboxylic acid compound having 2 to 8 carbon atoms is preferable. In the present invention, the term “carboxylic acid compound” is used generically, including derivatives such as carboxylic acids, acid anhydrides, and alkyl (C 1 -C 3) esters.

  Aromatic dicarboxylic acid compounds such as phthalic acid, isophthalic acid, and terephthalic acid are preferred from the viewpoint of the balance between low-temperature fixability, storage stability, and charge riseability of the toner.

  In the carboxylic acid component, the aromatic dicarboxylic acid compound is preferably 20 to 100 mol%, more preferably 30 to 90 mol%, and still more preferably 40 to 80 mol%, from the viewpoint of low-temperature fixability and storage stability of the toner. is there.

  Aliphatic dicarboxylic acid compounds such as oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid and azelaic acid are preferred from the viewpoint of low-temperature fixability.

  Other carboxylic acid compounds such as cycloaliphatic dicarboxylic acid, cycloaliphatic dicarboxylic acids; trimellitic acid, pyromellitic acid and other polyvalent carboxylic acids; rosin; modified with fumaric acid, maleic acid, acrylic acid, etc. Rosin and the like.

  In the present invention, the carboxylic acid component is a trivalent or higher polyvalent carboxylic acid compound, preferably a trimellitic acid compound, more preferably trimellitic anhydride, from the viewpoint of increasing the molecular weight and improving low-temperature fixability and storage stability of the toner. It is desirable to contain. The content of the trivalent or higher polyvalent carboxylic acid compound is preferably 0.1 to 50 mol%, more preferably 1 to 30 mol%, and still more preferably 5 to 25 mol% in the carboxylic acid component.

  The alcohol component may contain a monovalent alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid compound as appropriate from the viewpoint of adjusting the molecular weight and improving offset resistance.

  The molar ratio of the carboxylic acid component to the alcohol component (carboxylic acid component / alcohol component) is preferably 0.5 to 1.3, more preferably 0.6 to 1.1.

  The polyester resin for toner of the present invention can be obtained by polycondensation of the reaction product of the aromatic compounds represented by the formula (I), the alcohol component, and the carboxylic acid component.

  The amount of the reaction product to be subjected to the polycondensation reaction is 2.5 to 160 parts by weight with respect to 100 parts by weight of the total amount of the carboxylic acid component and the alcohol component from the viewpoints of storage stability, charge rising property, and hot offset resistance. Preferably, 2.5 to 80 parts by weight is more preferable, 10 to 70 parts by weight is further preferable, and 15 to 60 parts by weight is still more preferable.

  The polycondensation reaction is preferably performed at a temperature of 160 to 250 ° C. in an inert gas atmosphere in the presence of an esterification catalyst such as a tin compound or a titanium compound. More preferably, from the viewpoint of improving the reactivity of the reaction product, improving the charge rising property and hot offset resistance and improving the decomposition stability, the carboxylic acid component and the alcohol component are preferably 200 to A step of performing a condensation polymerization reaction at 250 ° C., more preferably 210 to 240 ° C., and then adding the reaction product, and preferably a step of a condensation polymerization reaction at 160 to 210 ° C., more preferably 170 to 200 ° C. The method is desirable.

  As the tin compound, for example, dibutyltin oxide is known, but in the present invention, a tin (II) compound having no Sn—C bond is preferable from the viewpoint of good dispersibility in the polyester. .

  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. Preferably, a tin (II) compound having a Sn—O bond is more preferable.

Examples of tin (II) compounds having Sn-O bonds include tin (II) oxalate, tin (II) acetate, tin (II) octoate, tin (II) 2-ethylhexanoate, and tin (II) laurate. , Tin (II) carboxylate having a carboxylic acid group having 2 to 28 carbon atoms such as tin (II) stearate, tin (II) oleate; octyloxy tin (II), lauroxy tin (II), stearoxy tin (II) ), Alkoxytin (II) having an alkoxy group having 2 to 28 carbon atoms such as oleyloxytin (II); tin (II) oxide; tin (II) sulfate, Sn—X (X represents a halogen atom) Examples of the tin (II) compound having a bond include tin (II) halides such as tin (II) chloride and tin (II) bromide, and among these, from the standpoint of charge rising effect and catalytic ability , (R ³ COO) ₂ Sn (where R ³ represents an alkyl group or alkenyl group having 5 to 19 carbon atoms), (R ⁴ O) ₂ Sn (where R ⁴ Is C 6-20 alk Alkoxy tin (II) and tin oxide represented by SnO (II) is preferably represented by a group or an alkenyl group), (R ³ COO) fatty tin represented by ₂ Sn (II) and tin oxide ( II) is more preferable, and tin (II) octoate, tin (II) 2-ethylhexanoate, tin (II) stearate and tin (II) oxide are 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 bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₅ H ₁₁ O) ₂ ], titanium diety 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) (C ₃ H ₇ O) ₃ ], titanium monopropylate tris (triethanolaminate) [Ti (C ₆ H ₁₄ O ₃ N) ₃ (C ₃ H ₇ O)] and the like, among these, titanium diisopropylate bistri Ethanolaminate, titanium diisopropylate bisdiethanolamate and titanium dipentylate bistriethanolamate are preferred, and these are also available as commercial products of Matsumoto Trading Co., Ltd., for example.

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, tetra Myristyl titanate, tetraoctyl titanate and dioctyl dihydroxy octyl titanate are preferred. These can be obtained, for example, by reacting a titanium halide with a corresponding alcohol, or can be obtained as a commercial product such as Nisso.

  The abundance of the esterification catalyst is preferably 0.01 to 2.0 parts by weight, more preferably 0.1 to 1.5 parts by weight, and more preferably 0.2 to 1.0 parts by weight based on 100 parts by weight of the total amount of the reaction product, alcohol component and carboxylic acid component. Part is more preferred. Here, the abundance of the esterification catalyst means the total amount of the catalyst subjected to the condensation polymerization reaction.

  In the present invention, it is possible to use a pyrogallol compound having a benzene ring in which hydrogen atoms bonded to three carbon atoms adjacent to each other are substituted with a hydroxyl group as an auxiliary catalyst together with an esterification catalyst. This is preferable from the viewpoint of increasing the reactivity and improving the storage stability of the toner.

  Examples of pyrogallol compounds include pyrogallol, gallic acid, gallic acid esters, 2,3,4-trihydroxybenzophenone, benzophenone derivatives such as 2,2 ', 3,4-tetrahydroxybenzophenone, epigallocatechin, epigallocatechin gallate, etc. Among these, from the viewpoint of hot offset resistance of the obtained resin, the formula (III):

Wherein R ^{5 to} R ⁷ are each independently a hydrogen atom or —COOR ⁸ (R ⁸ is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group or carbon having 1 to 12 carbon atoms. Represents an alkenyl group of 2 to 12)
The compound represented by these is preferable. In the formula, the hydrocarbon group of R ⁸ preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms from the viewpoint of reaction activity. Among the compounds represented by the formula (III), a compound in which R ⁵ and R ⁷ are hydrogen atoms and R ⁶ is a hydrogen atom or —COOR ⁸ is more preferable. Specific examples include pyrogallol (R ^{5 to} R ⁷ : hydrogen atom), gallic acid (R ⁵ and R ⁷ : hydrogen atom, R ⁶ : —COOH), ethyl gallate (R ⁵ and R ⁷ : hydrogen atom, R ^6: -COOC ₂ H _5), propyl gallate (R ⁵ and R ^7: a hydrogen _{^{atom, R 6: -COOC 3 H 7}} ), butyl gallate (R ⁵ and R ^7: a hydrogen atom, R ^6: -COOC ₄ H _9), octyl gallate (R ⁵ and R ^7: a hydrogen _{^{atom, R 6: -COOC 8 H 17}} ), lauryl gallate (R ⁵ and R ^7: a hydrogen _{^{atom, R 6: -COOC 12 H 25}} ) And gallic acid esters. From the viewpoint of toner storage stability, gallic acid and gallic acid esters are preferred.

  The amount of the pyrogallol compound in the condensation polymerization reaction is 0.001 to 1.0 weight from the viewpoint of storage stability of the toner with respect to a total of 100 parts by weight of the reaction product, alcohol component and carboxylic acid component subjected to the condensation polymerization reaction. Part is preferable, 0.005 to 0.4 part by weight is more preferable, and 0.01 to 0.2 part by weight is further preferable. Here, the abundance of the pyrogallol compound means the total amount of the pyrogallol compound subjected to the condensation polymerization reaction.

  The esterification catalyst used together with the pyrogallol compound is preferably at least one metal catalyst selected from the group consisting of tin compounds, titanium compounds, antimony trioxide, zinc acetate, and germanium dioxide.

  The weight ratio of the pyrogallol compound to the esterification catalyst (pyrogallol compound / esterification catalyst) is preferably from 0.01 to 0.5, more preferably from 0.03 to 0.3, and even more preferably from 0.05 to 0.2, from the viewpoint of storage stability of the toner.

  The polyester-based resin for toner of the present invention refers to a resin containing a polyester unit obtained by condensation polymerization of a reaction product, an alcohol component, and a carboxylic acid component.

  The polyester may be a polyester modified to such an extent that the properties are not substantially impaired.

  Examples of the polyester-modified resin include polyester / polyamide, urethane-modified polyester in which polyester is modified with a urethane bond, epoxy-modified polyester in which polyester is modified with an epoxy bond, and two or more kinds including a polyester component and a vinyl resin component. Examples thereof include a composite resin having a resin component.

  A composite resin having a polyester component and a vinyl resin component is prepared by a method of melt-kneading each resin in the presence of an initiator or the like, a method of dissolving and mixing each resin in a solvent, It may be produced by any method such as a method of polymerizing the raw material monomer mixture. A resin obtained by a method of performing a condensation polymerization reaction and an addition polymerization reaction using a raw material monomer for the polyester component and a raw material monomer for the vinyl resin component is preferable (Japanese Patent Laid-Open No. 7-98518). Specifically, in addition to the raw material monomer of the condensation polymerization resin and the raw material monomer of the addition polymerization resin, a compound capable of reacting with both the raw material monomer of the condensation polymerization resin and the raw material monomer of the addition polymerization resin (both reactions) It is preferable that the resin be a hybrid resin (resin in which a condensation polymerization resin and an addition polymerization resin are partially bonded via an both-reactive monomer). As the both reactive monomers, in the molecule, 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, preferably a hydroxyl group and / or A compound having a carboxyl group, more preferably a carboxyl group and an ethylenically unsaturated bond is preferred, and acrylic acid, methacrylic acid and fumaric acid are more preferred.

  Raw material monomers for vinyl resin components include styrene compounds such as styrene and α-methylstyrene; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyls such as vinyl chloride; vinyl acetate Vinyl esters such as vinyl propionate; alkyl (1 to 18 carbon atoms) esters of (meth) acrylic acid; esters of ethylenic monocarboxylic acids such as dimethylaminoethyl (meth) acrylate; vinyl ethers such as vinyl methyl ether And vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinylpyrrolidone and the like. Styrene, butyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate are preferable from the viewpoints of reactivity, grindability, and charge stability, and an alkyl ester of styrene and / or (meth) acrylic acid is a vinyl resin component. The content is preferably 50% by weight or more, more preferably 80 to 100% by weight.

  In addition, when polymerizing the raw material monomer of a vinyl-type resin component, you may use a polymerization initiator, a crosslinking agent, etc. as needed.

  The weight ratio of the polyester component raw material monomer (including the reaction product) to the vinyl resin component raw material monomer (polyester component raw material monomer / vinyl resin component raw material monomer) is determined from the viewpoint of forming a continuous phase with the polyester component. , Preferably 55/45 to 95/5, more preferably 60/40 to 95/5, and even more preferably 70/30 to 90/10. The bireactive monomer is a raw material monomer for the polyester component.

  The softening point of the polyester-based resin for toner of the present invention is preferably 90 to 160 ° C, more preferably 100 to 150 ° C, and further preferably 105 to 145 ° C, from the viewpoint of toner fixability, storage stability and hot offset resistance. preferable.

  When the polyester resin of the present invention is used as a binder resin, it is preferable to use both a resin having a high softening point and a resin having a low softening point from the viewpoint of low-temperature fixability, storage stability, and charge rising property of the toner. Preferably, it is composed of a high softening point resin and a low softening point resin that are different by 10 ° C. or more, more preferably 20 to 60 ° C. The softening point of the high softening point resin is preferably more than 125 ° C and not more than 160 ° C, more preferably 130 to 150 ° C, and the softening point of the low softening point resin is preferably 90 to 125 ° C, more preferably 90 ° C. ~ 110 ° C. 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, and more preferably 1/3 to 2/1.

  The glass transition point is preferably 45 to 85 ° C., more preferably 50 to 80 ° C., from the viewpoint of toner fixability, storage stability and hot offset resistance.

  From the standpoint of charge rise, the acid value is preferably 5 to 90 mgKOH / g, more preferably 10 to 80 mgKOH / g, further preferably 10 to 70 mgKOH / g, and the hydroxyl value is preferably 1 to 80 mgKOH / g, 8 -60 mgKOH / g is more preferable, and 8-55 mgKOH / g is more preferable.

  By using the polyester resin of the present invention as a binder resin, it is possible to obtain an electrophotographic toner excellent in charge rising property and hot offset resistance while maintaining low-temperature fixability and storage stability of the toner.

  In the toner of the present invention, a known binder resin, for example, a vinyl resin such as styrene-acrylic resin, an epoxy resin, a polycarbonate, a polyurethane, or the like is used in combination as long as the effects of the present invention are not impaired. However, the content of the polyester resin of the present invention is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and substantially 100% by weight in the binder resin. More preferably.

  The toner of the present invention further includes a colorant, a release agent, a charge control agent, a charge control resin, a magnetic powder, a fluidity improver, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an oxidation Additives such as an inhibitor, an anti-aging agent, and a cleaning property improver may be appropriately contained.

  As the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow and the like can be used, and the toner of the present invention may be either a black toner or a color toner. The content of the colorant is preferably 1 to 40 parts by weight and more preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  Release agents include polyolefin wax, paraffin wax, silicones; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide; carnauba wax, rice wax, candelilla wax, wood wax, jojoba Plant waxes such as oils; animal waxes such as beeswax; waxes such as mineral and petroleum waxes such as montan wax, ozokerite, ceresin, microcrystalline wax, and Fischer-Tropsch wax, which are used alone or in combination of two or more Can be mixed and used.

  The melting point of the release agent is preferably 60 to 160 ° C., more preferably 60 to 150 ° C., from the viewpoints of low-temperature fixability and offset resistance of the toner.

  The content of the release agent is preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight, and more preferably 1.5 to 7 parts by weight from the viewpoint of dispersibility in the binder resin with respect to 100 parts by weight of the binder resin. Part by weight is more preferred.

  The charge control agent is not particularly limited, and may contain either a positively chargeable charge control agent or a negatively chargeable charge control agent.

  Examples of positively chargeable charge control agents include nigrosine dyes such as “Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO”, “Bontron N-01”, “Bontron N-07”, “Bontron N-09” ”,“ Bontron N-11 ”(manufactured by Orient Chemical Co., Ltd.), etc .; triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds such as“ Bontron P-51 ”(Orient Chemical) Manufactured by Kogyo Co., Ltd.), cetyltrimethylammonium bromide, “COPY CHARGE PX VP435” (manufactured by Hoechst), etc .; polyamine resin such as “AFP-B” (manufactured by Orient Chemical Industries), etc .; imidazole derivative such as “PLZ-2001” , “PLZ-8001” (manufactured by Shikoku Kasei Co., Ltd.) and the like.

  In addition, as a negatively chargeable charge control agent, metal-containing azo dyes such as “Varifirst Black 3804”, “Bontron S-31” (above, manufactured by Orient Chemical Industries), “T-77” (Hodogaya Chemical) Manufactured by Kogyo Co., Ltd.), Bontron S-32, Bontron S-34, Bontron S-36 (above, Orient Chemical Co., Ltd.), Eisenspiron Black TRH (Hodogaya Chemical Co., Ltd.) A metal compound of a benzylic acid compound, such as “LR-147”, “LR-297” (manufactured by Nippon Carlit Co., Ltd.); a metal compound of a salicylic acid compound, such as “Bontron E-81”, “Bontron E- 84, “Bontron E-88”, “E-304” (manufactured by Orient Chemical Co., Ltd.), “TN-105” (manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dye; quaternary ammonium salt such as “ COPY CHARGE NX VP434 "(Hoechst), nitroimidazole derivative; organometallic compound , For example, "TN105" (commercially available from Hodogaya Chemical Co., Ltd.), and the like.

  The content of the charge control agent is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, and more preferably 0.3 to 3 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of the charge rising property of the toner. More preferably, 0.5 to 3 parts by weight is even more preferable, and 1 to 2 parts by weight is even more preferable.

  The toner of the present invention preferably contains a charge control resin in order to improve chargeability. As the charge control resin, a styrene resin is preferable, and from the viewpoint of developing positive chargeability of the toner, a quaternary ammonium base-containing styrene resin is preferable, and from the viewpoint of developing negative chargeability of the toner, a sulfonic acid group-containing styrene. Based resins are preferred.

  As the quaternary ammonium base-containing styrene resin, the formula (IVa):

(Wherein R ⁹ represents a hydrogen atom or a methyl group)
A monomer represented by the formula (IVb):

(Wherein R ¹⁰ represents a hydrogen atom or a methyl group, and R ¹¹ represents an alkyl group having 1 to 12 carbon atoms)
And a monomer represented by formula (IVc):

(Wherein R ¹² represents a hydrogen atom or a methyl group, and R ¹³ and R ¹⁴ each independently represents an alkyl group having 1 to 4 carbon atoms)
A quaternary ammonium base-containing styrene acrylic resin obtained by polymerizing a monomer mixture containing the monomer represented by the formula (1) or a quaternized product thereof is more preferable. The monomer may be quaternized in advance, or may be quaternized after polymerization. Examples of the quaternizing agent include alkyl halides such as methyl chloride and methyl iodide, diethyl sulfate, and di-n-propyl sulfate.

As the monomer represented by the formula (IVa), styrene in which R ⁹ is preferably a hydrogen atom is preferable, and as the monomer represented by the formula (IVb), R ¹⁰ is preferably a hydrogen atom, and R ¹¹ is preferably an alkyl group having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Specific examples of the monomer represented by the formula (IVb) include butyl acrylate and 2-ethylhexyl acrylate. The monomer represented by the formula (IVc) is preferably a monomer in which R ¹² is a methyl group, and R ¹³ and R ¹⁴ are a methyl group or an ethyl group, and more preferably R ¹² , R ¹³ and R ^14. Each is preferably dimethylaminoethyl methacrylate where is a methyl group.

  In the quaternary ammonium base-containing styrene resin, the content of the monomer represented by the formula (IVa) in the monomer mixture is preferably 60 to 97% by weight, more preferably 70 to 90% by weight. The content of the monomer represented by the formula (IVb) is preferably 1 to 33% by weight, more preferably 5 to 20% by weight, and the monomer represented by the formula (IVc) or 4 thereof The content of the graded product is preferably 2 to 35% by weight, more preferably 5 to 20% by weight.

  Specific examples of the quaternary ammonium base-containing styrenic resin obtained using the monomers represented by the formulas (IVa) to (IVc) include butyl acrylate, N, N-diethyl-N-methyl-2- And (methacryloyloxy) ethylammonium / styrene copolymer.

  As the sulfonic acid group-containing styrene resin, the monomer represented by the above formula (IVa), the monomer represented by the formula (IVb), and the monomer containing the sulfonic acid group-containing monomer A sulfonic acid group-containing styrene resin obtained by polymerizing the mixture is preferred.

  Examples of the sulfonic acid group-containing monomer include (meth) allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, and styrenesulfonic acid. Specific examples include 2-ethylhexyl acrylate, 2-acrylamido-2-methyl-1-propanesulfonic acid, styrene copolymer, and the like.

  In the sulfonic acid group-containing styrenic resin, the content of the monomer represented by the formula (IVa) in the monomer mixture is preferably 60 to 97 wt%, more preferably 70 to 90 wt%, The content of the monomer represented by the formula (IVb) is preferably 1 to 33% by weight, more preferably 5 to 20% by weight, and the content of the sulfonic acid group-containing monomer is preferably 2 to 35%. It is desirable that the amount be 5% by weight, more preferably 5 to 20% by weight.

  In both the quaternary ammonium group-containing styrene resin and the sulfonic acid group-containing styrene resin, the polymerization of the monomer mixture is performed, for example, in the presence of a polymerization initiator such as azobisdimethylvaleronitrile. It can carry out by heating to 50-100 degreeC in inert gas atmosphere. The polymerization method may be any of solution polymerization, suspension polymerization or bulk polymerization, but is preferably solution polymerization.

  The softening point of the styrenic resin is preferably from 100 to 140 ° C, more preferably from 110 to 130 ° C, from the viewpoint of low-temperature fixability of the toner.

  The amount of the styrenic resin contained as the charge control resin is preferably 3 to 40 parts by weight, more preferably 4 to 30 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of developing the chargeability of the toner. 5 to 20 parts by weight is more preferable.

  The toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion phase inversion method, or a polymerization method, but from the viewpoint of productivity and dispersibility of the colorant, A pulverized toner obtained by a melt kneading method is preferred. In the case of pulverized toner by the melt-kneading method, for example, a raw material such as a binder resin, a colorant, and a charge control agent is uniformly mixed with a mixer such as a Henschel mixer, and then a hermetically sealed kneader, a single or twin screw extruder It can be produced by melt-kneading with an open roll kneader or the like, cooling, pulverizing and classifying. On the other hand, from the viewpoint of reducing the particle size of the toner, a toner by a polymerization method is preferable.

The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably 3 to 15 μm, more preferably 3 to 10 μm. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size.

  In the toner of the present invention, it is preferable to use inorganic fine particles as an external additive in order to improve transferability. Specifically, at least one selected from the group consisting of silica, alumina, titania, zirconia, tin oxide, and zinc oxide is preferable. Among these, silica is preferable, and from the viewpoint of preventing embedding, the specific gravity is More preferably, small silica is contained.

  Silica is preferably hydrophobic silica that has been subjected to a hydrophobic treatment, from the viewpoint of toner transferability.

  As a method for hydrophobizing silica, silanol groups on the surface of silica particles are preferably modified with a hydrophobic group such as an alkylsilyl group having 1 to 12 carbon atoms (for example, methylsilyl group, hexylsilyl group, etc.), or It is preferable to coat the surface with a hydrophobic resin.

  Examples of the hydrophobizing agent for hydrophobizing the surface of silica particles include organochlorosilane, organoalkoxysilane, organodisilazane, cyclic organopolysilazane, linear organopolysiloxane, and the like. Examples thereof include silazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), methyltriethoxysilane, and the like. Among these, hexamethyldisilazane is preferable.

  The average particle diameter of the external additive is from 10 to 250 nm, preferably from 10 to 200 nm, more preferably from 15 to 90 nm, from the viewpoint of chargeability, fluidity, and transferability of the toner.

  The content of the external additive is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, and still more preferably 0.3 to 100 parts by weight of toner particles before being processed with the external additive. ~ 3 parts by weight.

  The toner of the present invention can be used as a one-component developing toner or as a two-component developer mixed with a carrier.

(Weight average molecular weight of reaction product)
The molecular weight distribution is measured by the gel permeation chromatography (GPC) method according to the following method to determine the weight average molecular weight.
(1) Preparation of sample solution The reaction product is dissolved in tetrahydrofuran so that the concentration is 0.5 g / 100 ml. Next, this solution is filtered using a fluororesin filter having a pore size of 2 μm (FP-200, manufactured by Sumitomo Electric Industries, Ltd.) to remove insoluble components, thereby obtaining a sample solution.
(2) Molecular weight measurement Using the following measuring device and analytical column, tetrahydrofuran is flowed as an eluent at a flow rate of 1 ml / min, and the column is stabilized in a constant temperature bath at 40 ° C. Measurement is performed by injecting 100 μl of the sample solution. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. At this time, 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 are used.
Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation)
Analytical column: GMHXL + G3000HXL (manufactured by Tosoh Corporation)

[Softening point of resin]
Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample is heated at a heating rate of 6 ° C / min, and a 1.96 MPa load is applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. . The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Glass transition point of resin]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), weigh 0.01 to 0.02 g of the sample into an aluminum pan, raise the temperature to 200 ° C, and from that temperature to 0 ° C at a rate of 10 ° C / min. The temperature of the cooled sample is raised at a heating rate of 10 ° C / min, and the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent that indicates the maximum slope from the peak rise to the peak apex To do.

[Acid value of the resin]
Measured according to the method of JIS K0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Hydroxyl value of the resin]
Measured according to the method of JIS K0070.

[Melting point of release agent]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature was raised to 200 ° C, and the sample was cooled to 0 ° C at a temperature drop rate of 10 ° C / min. The maximum peak temperature of heat of fusion is taken as the melting point.

[Average particle size of external additives]
The average particle diameter refers to the number average particle diameter, which is the average value of the particle diameters of 500 particles measured from a scanning electron microscope (SEM) photograph of the external additive. When there is a major axis and a minor axis, the major axis is indicated.

[Volume-median particle diameter of toner (D ₅₀ )]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 50μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) 5% electrolyte dispersion condition: 10 mg of measurement sample is added to 5 ml of dispersion, and dispersed for 1 minute with an ultrasonic disperser. Then, 25 ml of the electrolytic solution is added, and further dispersed with an ultrasonic disperser for 1 minute.
Measurement conditions: Add 100 ml of electrolyte and dispersion in a beaker, measure 30,000 particles at a concentration that can measure the particle size of 30,000 particles in 20 seconds, and determine the volume-median particle size ( determine the D _50).

Reaction product production example [reaction products A to H]
The aromatic compounds shown in Table 1 were put into a 5-liter four-necked flask equipped with a dehydration tube equipped with a nitrogen introduction tube, a stirrer and a thermocouple, and melted at 180 ° C. in a nitrogen atmosphere. The reaction was performed at 180 ° C. for 8 hours. Thereafter, it was confirmed that the obtained reaction product had a weight average molecular weight of 350 or more.

Resin Production Example 1 [Resin 1 to 3, 5 to 11, 13]
Table 2-4 alcohol components, carboxylic acid components other than trimellitic anhydride, reaction products, and esterification catalyst, nitrogen introduction tube, dehydration tube equipped with a fractionation tube through which hot water of 98 ° C was passed, stirring Put in a 5 liter four-necked flask equipped with a vacuum vessel and thermocouple, raise the temperature from 180 ° C to 210 ° C at 10 ° C / hr under a nitrogen atmosphere, and then at 210 ° C until the reaction rate reaches 90% A condensation polymerization reaction was performed. Thereafter, trimellitic anhydride was added and reacted at 210 ° C. for 1 hour at normal pressure, and then reacted at 20 kPa until the softening points shown in Tables 2 to 4 were reached to obtain a polyester. Here, the reaction rate is a value converted to 100% when the theoretical reaction water is completely discharged, calculated from the alcohol component, the carboxylic acid component, and the carboxy group and hydroxyl group of the reaction product.

Resin Production Example 2 [Resin 4]
The alcohol component, carboxylic acid component and esterification catalyst shown in Table 2 are put into a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and reacted at 235 ° C. in a nitrogen atmosphere. The condensation polymerization reaction was continued until the rate reached 90%. Then, it cooled to 200 degreeC, the reaction product was added, and it was made to react at a normal pressure for 3 hours. Thereafter, trimellitic anhydride was added and reacted at 210 ° C. for 1 hour at normal pressure, and then reacted at 20 kPa until the softening point shown in Table 2 was reached to obtain a polyester.

Resin Production Example 3 [Resin 12]
The alcohol component shown in Table 5, the carboxylic acid component other than trimellitic anhydride, and the esterification catalyst were put into a 5-liter four-necked flask equipped with a dehydration tube equipped with a nitrogen introduction tube, a stirrer and a thermocouple, The temperature was raised to 160 ° C. in a nitrogen atmosphere. Thereafter, a mixture of the amphoteric monomer (acrylic acid), the raw material monomer of the vinyl resin, and the polymerization initiator shown in Table 5 was added dropwise over 1 hour using a dropping funnel. After dropping, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C. Thereafter, the reaction product shown in Table 5 was added, the temperature was raised to 180 ° C., and the reaction was conducted for 2 hours. Then, the temperature was raised to 210 ° C. at 5 ° C./h, and the reaction rate reached 90% at 210 ° C. The reaction was allowed to reach. Thereafter, trimellitic anhydride was added, the mixture was reacted at 200 ° C. under normal pressure for 1 hour, and reacted at 10 kPa until the softening point shown in Table 5 was reached, to obtain a hybrid resin.

Resin Production Example 4 [Resin 14, 15]
Dehydration tube, stirrer, and thermocouple equipped with alcohol components, carboxylic acid components other than trimellitic anhydride and esterification catalysts shown in Tables 2 to 4, and a fractionation tube through which hot water of 98 ° C. was passed. In a 5 liter four-necked flask equipped with, raise the temperature from 180 ° C to 210 ° C at 10 ° C / hr in a nitrogen atmosphere, and then subject the polycondensation reaction to a reaction rate of 90% at 210 ° C. It was. Thereafter, trimellitic anhydride was added and reacted at 210 ° C. for 1 hour at normal pressure, and then reacted at 20 kPa until the softening points shown in Tables 2 to 4 were reached to obtain a polyester.

Resin Production Example 5 [Resin 16]
Put the alcohol component, carboxylic acid component other than trimellitic anhydride and esterification catalyst shown in Table 4 into a 5 liter four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple, and a nitrogen atmosphere. The polycondensation reaction was continued at 235 ° C. until the reaction rate reached 90%. Thereafter, trimellitic anhydride was added and reacted at 210 ° C. for 1 hour at normal pressure, and then reacted at 20 kPa until the softening point shown in Table 4 was reached to obtain a polyester.

Examples 1 to 21 and Comparative Examples 1 and 2
100 parts by weight of a binder resin shown in Table 6, 1.0 part by weight of a negatively chargeable charge control agent, 5.0 parts by weight of a colorant, and 2.0 parts by weight of polypropylene wax were mixed using a Henschel mixer. The obtained mixture was melt-kneaded by a twin screw extruder, cooled, and then roughly pulverized to about 1 mm using a hammer mill. The resulting coarsely pulverized product is finely pulverized by an air jet type pulverizer (IDS-2 type, manufactured by Nippon Pneumatic Co., Ltd.), classified, and toner particles having a volume median particle size (D ₅₀ ) of 7.5 μm. Got.

  To 100 parts by weight of the obtained toner particles, 1.0 part by weight of an external additive was added and mixed with a Henschel mixer to obtain a toner.

  The colorant, charge control agent, release agent, and charge control resin used in each example and comparative example are as follows.

[Colorant]
Black pigment: “Mogul-L” (Cabot), carbon black cyan pigment: “ECB-301” (Daiichi Seika), Pigment Blue 15: 3
Magenta pigment: “Super Magenta R” (Dainippon Ink Chemical Co., Ltd.), Pigment Red 122
Yellow pigment: “Paliotol Yellow D1155” (manufactured by BASF), Pigment Yellow 185

[Charge control agent]
CCA-A: "Bontron S-34" (manufactured by Orient Chemical Industries), negatively chargeable charge control agent
CCA-B: “Bontron N-04” (manufactured by Orient Chemical Industries), positively chargeable charge control agent
CCA-C: “LR-147” (manufactured by Nippon Carlit), negatively chargeable charge control agent
CCA-D: “Bontron E-84” (manufactured by Orient Chemical Industries), negatively chargeable charge control agent

〔Release agent〕
Wax-A: “High Wax NP-056” (Mitsui Chemicals), polypropylene wax, melting point 125 ° C.
Wax-B: “HNP-9” (Nippon Seiki Co., Ltd.), paraffin wax, melting point 75 ° C.
Wax-C: “Carnauba wax C1” (manufactured by Kato Yoko), melting point 80 ° C.

[Charge control resin]
CCR-A: "FCA-701PT" (Fujikura Kasei Co., Ltd.), positively chargeable charge control resin, quaternary ammonium base-containing styrene acrylic copolymer, softening point: 123 ° C

(External additive)
Silica-A: “R-972” (manufactured by Nippon Aerosil Co., Ltd.), negatively charged hydrophobic silica, average particle size 16 nm, hydrophobizing agent DMDS (dimethyldichlorosilane)
Silica-B: “HDK H3050VP” (manufactured by Clariant), positively charged hydrophobic silica, average particle size 8 nm, hydrophobizing agent aminosilane silica-C: “SI-Y” (manufactured by Nippon Aerosil Co., Ltd.), negatively chargeable Hydrophobic silica, average particle size 40nm, hydrophobizing agent dimethyl silicone oil

Test Example 1 [low temperature fixability]
An apparatus in which a fixing machine of a copying machine “AR-505” (manufactured by Sharp Corporation) is improved so that fixing can be performed outside the apparatus (however, for evaluation of Example 15, a non-magnetic single-component developing printer “ The toner was mounted on “HL-2040” (manufactured by Brother Industries, Ltd.) and an unfixed image was obtained. After that, with a fixing machine (fixing speed 390mm / sec) adjusted so that the total fixing pressure is 40kgf, the fixing test of unfixed images was performed at each temperature while increasing the temperature gradually from 100 ° C to 240 ° C by 10 ° C. It was. “UNICEF Cellophane” (Mitsubishi Pencil Co., Ltd., width: 18 mm, JISZ-1522) was pasted on the fixed image, passed through a fixing roller set at 30 ° C., and then the tape was peeled off. The optical reflection density before and after applying the tape was measured using a reflection densitometer “RD-915” (manufactured by Macbeth Co., Ltd.). The fixing roller temperature exceeding 100% was set as the minimum fixing temperature, and the low-temperature fixing property was evaluated according to the following evaluation criteria. The results are shown in Table 6. The paper used for the fixing test is CopyBond SF-70NA (75 g / m ² ) manufactured by Sharp Corporation.

〔Evaluation criteria〕
A: The minimum fixing temperature is less than 150 ° C.
B: The minimum fixing temperature is 150 ° C. or higher and lower than 170 ° C.
C: The minimum fixing temperature is 170 ° C. or higher.

Test example 2 [preservability] (all common)
4 g of toner was placed in a 20 ml cylindrical container (diameter: about 3 cm) and left for 72 hours in an environment at a temperature of 55 ° C. and a relative humidity of 60%. After standing, the degree of toner aggregation occurrence was visually observed, and storage stability was evaluated according to the following evaluation criteria. The results are shown in Table 6.

〔Evaluation criteria〕
A: No aggregation is observed even after 72 hours.
B: Aggregation is not observed after 48 hours, but aggregation is observed after 72 hours.
C: Aggregation is observed at 48 hours.

Test Example 3 [Charge rising property]
0.6 g of toner and 19.4 g of silicone ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size 90 μm) (However, in Example 15, the carrier is “P-01” (ferrite carrier: Japan Imaging Society standard product, average particle size) : 70μm)) in a 50mL plastic bottle, mix for 10 minutes at 250r / min using a ball mill, and use a q / m meter (EPPING) to charge for 1 minute and 10 minutes. Measured.

  After a predetermined mixing time, a specified amount of developer is put into the cell attached to the q / m meter, and the above-mentioned measuring machine is used for 90 seconds through only a 32 μm mesh sieve (stainless steel, twill weave, wire diameter: 0.0035 mm). Sucked in. The voltage change on the carrier generated at that time was monitored, and the charge rising property was evaluated according to the following evaluation criteria. The results are shown in Table 6.

〔Evaluation criteria〕
The value of (Charge amount at 1 minute of mixing time) / (Charge amount at 10 minutes of mixing time) is A: 0.95 or more B: 0.9 or more and less than 0.95 C: Less than 0.9

Test Example 4 [Hot offset resistance]
In Test Example 1, when the temperature of the fixing roll is sequentially increased from 100 ° C. to 240 ° C., the temperature at which the offset is first confirmed is visually determined, and the hot offset resistance is evaluated according to the following evaluation criteria. did. The results are shown in Table 6.
〔Evaluation criteria〕
A: Hot offset generation temperature is 210 ° C or higher B: Hot offset generation temperature is 180 ° C or higher and lower than 210 ° C C: Hot offset generation temperature is lower than 180 ° C

  From the above results, the toners of Examples 1 to 21 containing the polyester resin obtained by using the reaction product of the aromatic compounds represented by the formula (I) as the binder resin are Comparative Example 1, Compared with the toner No. 2, it can be seen that both the low-temperature fixability and the storage stability of the toner are good, and that the charge rising property and the hot offset resistance are also excellent.

  The electrophotographic toner containing the polyester resin for toner of the present invention as a binder resin is suitably used for developing a latent image formed by electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims (9)

Formula (I):

(In the formula, R ¹ represents a hydrogen atom, a hydroxyl group or a methoxy group, and X represents a hydroxyl group or a carboxyl group which may have a linking group.)
A polyester-based resin for toner obtained by polycondensation of a reaction product of one or a plurality of aromatic compounds represented by the formula (I) and at least one of a carboxylic acid component and an alcohol component.   The polyester resin for toner according to claim 1, wherein the reaction product has a weight average molecular weight of 350 to 2,000.   The polyester-based resin for toner according to claim 1 or 2, wherein the linking group at X in formula (I) is a divalent unsaturated hydrocarbon group having 2 to 4 carbon atoms.   The polyester-based resin for toner according to any one of claims 1 to 3, wherein the amount of the reaction product subjected to the condensation polymerization reaction is 2.5 to 160 parts by weight with respect to 100 parts by weight of the total amount of the carboxylic acid component and the alcohol component. .   The polyester-based resin for toner according to any one of claims 1 to 4, wherein the alcohol component contains an aliphatic diol having 2 to 8 carbon atoms.   The aromatic compound represented by the formula (I) is at least one hydroxycarboxylic acid selected from the group consisting of ferulic acid, 5-hydroxyferulic acid, sinapinic acid, syringic acid and vanillic acid. ~ 5 polyester resin for toner according to any one of.   The aromatic compound represented by the formula (I) is at least one diol selected from the group consisting of coniferyl alcohol, 5-hydroxyconiferyl alcohol and sinapyr alcohol. Polyester resin for toner.   A binder resin for toner, comprising the polyester resin for toner according to any one of claims 1 to 7.   An electrophotographic toner comprising the toner binder resin according to claim 8.