JP5574529B2 - Toner for electrophotography - Google Patents

Description

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

  In recent years, with an increase in machine speed and energy saving, a toner having excellent low-temperature fixability has been demanded. Many polyesters having excellent low-temperature fixability have been studied as binder resins for toners. Among them, carboxylic acids having an aromatic ring that can improve the glass transition point while maintaining a low softening point are used as raw materials. Polyester obtained by using as a monomer is used.

  In Patent Document 1, there is a problem of a toner for developing an electrostatic charge image in which a small amount of fine particle particles generated as a by-product at the time of toner polymerization is further reduced, and a residual amount of a decomposition product of a polymerization initiator remaining in the toner is reduced. A polymerizable monomer composition containing at least a polymerizable monomer and a colorant is suspended in an aqueous dispersion medium containing a dispersion stabilizer, and droplets of the polymerizable monomer composition are dispersed. A method for producing a toner for developing electrostatic images, comprising a suspension step for obtaining a dispersed suspension, and a polymerization step for subjecting the suspension to suspension polymerization in the presence of a polymerization initiator to obtain colored resin particles. In the suspending step for obtaining the suspension, a production method is disclosed in which the small particle size inhibitor is contained in an aqueous dispersion medium in an amount of 0.01 to 1 part by weight with respect to 100 parts by weight of the polymerizable monomer. Caffeic acid is described as a small particle size fine particle inhibitor.

  Patent Document 2 discloses a core material having at least a reversibly colorable and erasable colorant for the purpose of providing a method for deinking and reproducing an image receiving sheet used in an image forming method such as electrophotography. And a shell material made of a shell-forming resin that coats the core material, and discloses a microencapsulated toner, in which coumaric acid is described as a colorant.

JP 2008-107759 A JP-A-7-199518

  However, a toner using a polyester obtained by using a carboxylic acid having an aromatic ring as a raw material monomer has a problem that charging stability is lowered under high temperature and high humidity, and in a toner corresponding to speeding up of a machine, Improvement in charging stability under high temperature and high humidity is desired.

  An object of the present invention is to provide a polyester resin for toner that can improve the charging stability under high temperature and high humidity while maintaining the low temperature fixability and storage stability of the toner, and a binder resin containing the polyester resin. And providing an electrophotographic toner containing the binder resin.

The present invention
[1] A polyester resin for toner obtained by polycondensation of a carboxylic acid component and an alcohol component, which is represented by the formula (I):

(Wherein, R ¹ and R ² each independently represent a hydrogen atom or a hydroxyl group, and X is —COOR ³ (R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) or —CH _2. OH, except that R ¹ and R ² are both hydrogen atoms.)
A polyester-based resin for toner obtained by using an aromatic compound represented by the carboxylic acid component and / or the alcohol component,
[2] A toner binder resin comprising the polyester resin for toner according to [1], and [3] an electrophotographic toner comprising the binder resin according to [2]. .

  The polyester resin for toner of the present invention is an excellent binder resin for electrophotographic toner that can improve the charging stability under high temperature and high humidity while maintaining the low temperature fixability and storage stability of the toner. It is effective.

  The polyester-based resin for toner of the present invention is greatly characterized in that it is a resin obtained by using a specific aromatic compound having a vinylene group in an aromatic ring as a carboxylic acid component and / or an alcohol component.

  The polyester-based resin for toner of the present invention is excellent in charging stability under high temperature and high humidity while maintaining the low-temperature fixability and storage stability of the toner. Since the aromatic compound has a vinylene group in the aromatic ring, when used as a polyester monomer, the glass transition point can be increased while lowering the softening point, and conventional terephthalic acid can be used. And aromatic carboxylic acid compounds such as isophthalic acid, the aromatic ring is more easily resonance-stabilized and electrons are stored in the aromatic ring. As a result, charging stability, especially charging at high temperature and high humidity It is considered that the stability is remarkably improved.

  The aromatic compound in the present invention has the formula (I):

(Wherein, R ¹ and R ² each independently represent a hydrogen atom or a hydroxyl group, and X is —COOR ³ (R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) or —CH _2. OH, except that R ¹ and R ² are both hydrogen atoms.)
It is represented by

In the formula (I), R ¹ represents a hydrogen atom or a hydroxyl group, and a hydroxyl group is preferred from the viewpoint of resonance stability of the aromatic ring. In general, the reactivity of the hydroxyl group directly bonded to the aromatic ring is low, but the aromatic compound represented by the formula (I) is easily stabilized by resonance, so that the reactivity of the hydroxyl group of R ¹ and R ² is increased. Conceivable.

Depending on the type of functional group, the aromatic compound represented by the formula (I) acts as either a carboxylic acid component or an alcohol component during the condensation polymerization as a raw material monomer for polyester. Since hydroxycarboxylic acid is mainly polycondensed as a carboxylic acid component, in the present invention, for convenience, the aromatic compound is a hydroxycarboxylic acid in which X has a carboxyl group, that is, X is —COOR ^3. In the case where X is an alcohol having no carboxyl group, that is, X is —CH ₂ OH, it is regarded as an alcohol component and used for calculation of the content and molar ratio.

In the aromatic compound represented by the formula (I), as the aromatic compound used as the carboxylic acid component, caffeic acid (X: —COOH, R ¹ : hydroxyl group, R ² : from the viewpoint of charging stability of the toner. At least one of hydroxyl group) and coumaric acid (X: —COOH, R ¹ : hydroxyl group, R ² : hydrogen atom) is more preferable.

As the aromatic compound used as the alcohol component, from the viewpoint of charging stability of the toner, coumaryl alcohol (X: —CH ₂ OH, R ¹ : hydroxyl group, R ² : hydrogen atom) and caffeyl alcohol (X : -CH ₂ OH, R ¹ : hydroxyl group, R ² : hydroxyl group) is preferred.

  In the polyester-based resin for toner of the present invention, the aromatic compound represented by the formula (I) may be contained in either or both of the carboxylic acid component and the alcohol component. From the viewpoint of charging stability of the toner, the aromatic compound represented by the formula (I) includes at least one selected from coumaric acid and caffeic acid and at least one selected from coumaryl alcohol and caffeyl alcohol. It is preferable.

  The content of the aromatic compound represented by the formula (I) is the total amount of the carboxylic acid component and the alcohol component constituting the polyester resin (that is, the carboxylic acid used in the polycondensation reaction) from the viewpoint of toner charging stability. The total amount of the component and the alcohol component) is preferably 0.5 to 80 mol%, more preferably 2.5 to 80 mol%, still more preferably 2.5 to 60 mol%, still more preferably 5 to 50 mol%, and still more preferably Is 7 to 25 mol%, more preferably 7 to 15 mol%.

  In addition, the content of the aromatic compound represented by the formula (I) in the carboxylic acid component constituting the polyester resin (that is, the carboxylic acid component used in the polycondensation reaction) is determined from the viewpoint of charging stability of the toner. , Preferably 0.5 to 80 mol%, more preferably 2.5 to 80 mol%, still more preferably 2.5 to 60 mol%, still more preferably 5 to 50 mol%, still more preferably 7 to 40 mol%. More preferably, it is 7 to 25 mol%. The content of the aromatic compound represented by the formula (I) in the alcohol component constituting the polyester resin (that is, the alcohol component used in the polycondensation reaction) is preferably 0.5 from the viewpoint of charging stability of the toner. -80 mol%, more preferably 2.5-80 mol%, still more preferably 2.5-60 mol%, even more preferably 5-50 mol%, still more preferably 7-40 mol%, even more preferably Is 7 to 25 mol%.

  The carboxylic acid component and the alcohol component used in the polyester resin for toner of the present invention may contain a carboxylic acid compound and / or alcohol other than the aromatic compound.

  Examples of the alcohol component other than the aromatic compound include formula (II):

(Wherein R ⁴ O and OR ⁴ are oxyalkylene groups, R ⁴ 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.

  When the aromatic compound is used as the carboxylic acid component, the content of the alkylene oxide adduct of bisphenol A is preferably 30 to 100 mol%, more preferably 50 to 50% in the alcohol component from the viewpoint of toner storage stability. It is 100 mol%, More preferably, it is 80-100 mol%.

  When the aromatic compound is used as an alcohol component, or when the aromatic compound is used as both an alcohol component and a carboxylic acid component, the content of the alkylene oxide adduct of bisphenol A is determined from the viewpoint of toner storage stability. In an alcohol component, Preferably it is 0-90 mol%, More preferably, it is 20-90 mol%, More preferably, it is 30-85 mol%.

  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.

  When the aromatic compound is used as the carboxylic acid component, the content of the aliphatic diol is preferably 30 to 100 mol%, more preferably 50 to 90 mol% in the alcohol component from the viewpoint of low-temperature fixability of the toner. More preferably, it is 80-100 mol%.

  When the aromatic compound is used as an alcohol component, or when the aromatic compound is used as both an alcohol component and a carboxylic acid component, the content of the aliphatic diol is determined in the alcohol component from the viewpoint of low-temperature fixability of the toner. The amount is preferably 0 to 90 mol%, more preferably 20 to 90 mol%, still more preferably 30 to 85 mol%.

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

  As the carboxylic acid component other than the aromatic compound, 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 low-temperature fixability and storage stability 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.

  When the aromatic compound is used as a carboxylic acid component, or when the aromatic compound is used as both an alcohol component and a carboxylic acid component, the content of the aromatic dicarboxylic acid compound is low-temperature fixability and storage stability of the toner. From the viewpoint, it is preferably 20 to 90 mol%, more preferably 30 to 90 mol%, still more preferably 30 to 80 mol% in the carboxylic acid component.

  When the aromatic compound is used as an alcohol component, the content of the aromatic dicarboxylic acid compound is preferably 20 to 100 mol%, more preferably in the carboxylic acid component, from the viewpoint of low-temperature fixability and storage stability of the toner. It is 30-90 mol%, More preferably, it is 40-80 mol%.

  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. The aliphatic dicarboxylic acid compound preferably has 2 to 10 carbon atoms, more preferably 3 to 9 carbon atoms.

  When the aromatic compound is used as a carboxylic acid component, or when the aromatic compound is used as both an alcohol component and a carboxylic acid component, the content of the aliphatic dicarboxylic acid compound is from the viewpoint of low-temperature fixability of the toner. In a carboxylic acid component, Preferably it is 20-90 mol%, More preferably, it is 30-90 mol%, More preferably, it is 30-80 mol%.

  When the aromatic compound is used as an alcohol component, the content of the aliphatic dicarboxylic acid compound is preferably 20 to 100 mol%, more preferably 30 to 90% in the carboxylic acid component from the viewpoint of low-temperature fixability of the toner. It is mol%, More preferably, it is 40-80 mol%.

  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 contains 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 the fixability and storage stability. It is desirable that The content of the trivalent or higher polyvalent carboxylic acid compound is preferably 0.1 to 30 mol%, more preferably 1 to 25 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 0.75 to 1.3, and more preferably 0.8 to 1.3.

  The condensation polymerization of the alcohol component and the carboxylic acid component 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. The polycondensation reaction of the compound is preferably from 160 to 210 ° C, more preferably from 170 to 200 ° C, from the viewpoint of reactivity and thermal decomposability. More preferably, after the polycondensation reaction of the divalent alcohol component and the divalent carboxylic acid component other than the aromatic compound, the aromatic compound is added, and the polycondensation reaction is performed at the above temperature. From the viewpoint of reactivity and thermal decomposability, it is preferable.

  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 ⁵ COO) ₂ Sn (wherein R ⁵ represents an alkyl group or alkenyl group having ⁵ to 19 carbon atoms), (R ⁶ O) ₂ Sn (where R ⁶ 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 ⁵ 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 amount 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 still more preferably 0.2 to 1.0 parts by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component. Here, the abundance of the esterification catalyst means the total amount of the catalyst subjected to the condensation polymerization reaction.

  In the present invention, using a pyrogallol compound having a benzene ring in which hydrogen atoms bonded to three adjacent carbon atoms are substituted with a hydroxyl group together with an esterification catalyst, the reactivity of the aromatic compound used in the present invention is reduced. It is preferable from the viewpoint of enhancing the toner storage stability.

  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 the durability of the resulting resin, the formula (III):

Wherein R ^{7 to} R ⁹ are each independently a hydrogen atom or —COOR ¹⁰ (R ¹⁰ 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 ¹⁰ 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 ⁷ and R ⁹ are hydrogen atoms and R ⁸ is a hydrogen atom or —COOR ¹⁰ is more preferable. Specific examples include pyrogallol (R ^{7 to} R ⁹ : hydrogen atom), gallic acid (R ⁷ and R ⁹ : hydrogen atom, R ⁸ : —COOH), ethyl gallate (R ⁷ and R ⁹ : hydrogen atom, R ^8: -COOC ₂ H _5), propyl gallate (R ⁷ and R ^9: a hydrogen _{^{atom, R 8: -COOC 3 H 7}} ), butyl gallate (R ⁷ and R ^9: a hydrogen atom, R ^8: -COOC ₄ H _9), octyl gallate (R ⁷ and R ^9: a hydrogen _{^{atom, R 8: -COOC 8 H 17}} ), lauryl gallate (R ⁷ and R ^9: a hydrogen _{^{atom, R 8: -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 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, from the viewpoint of storage stability of the toner. Preferably, 0.01 to 0.2 parts by weight is more preferable. Here, the abundance of the pyrogallol compound means the total amount of the pyrogallol compound subjected to the condensation polymerization reaction.

  The pyrogallol compound is considered to function as a promoter for the esterification catalyst. 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 of the present invention refers to a resin containing a polyester unit by condensation polymerization of an alcohol component and a carboxylic acid component, and includes not only polyester but also polyester / polyamide. Among these, durability and charge stability From the viewpoint of properties, polyester is preferred.

  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 a urethane-modified polyester obtained by modifying a polyester with a urethane bond, an epoxy-modified polyester obtained by modifying a polyester with an epoxy bond, and two or more resin components including a polyester component and a vinyl resin component. Examples include composite resins.

  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 raw material monomer of the polyester component to the raw material monomer of the vinyl resin component (the raw material monomer of the polyester component / the raw material monomer of the vinyl resin component) is preferably 55/45 to from the viewpoint of forming a continuous phase with the polyester component. It is 95/5, More preferably, it is 60 / 40-95 / 5, More preferably, it is 70 / 30-90 / 10. The bireactive monomer is a raw material monomer for the polyester component.

  The softening point of the polyester resin of the present invention is preferably from 90 to 160 ° C, more preferably from 100 to 150 ° C, and even more preferably from 105 to 145 ° C, from the viewpoint of toner fixability, storage stability and durability.

  It is preferable to use both a high softening point resin (high softening point resin) and a low resin (low softening point resin) for the polyester resin of the present invention from the viewpoint of low-temperature fixability, storage stability, and charging stability of the toner. .

  The difference in softening point between the high softening point resin and the low softening point resin is preferably 10 ° C or higher, more preferably 20 to 60 ° C.

  The softening point of the high softening point resin is preferably 125 to 160 ° C, more preferably 130 to 150 ° C, and the softening point of the low softening point resin is preferably 90 ° C or higher and lower than 125 ° C, more preferably 90 to 150 ° 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 1/2 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 durability.

  From the viewpoint of charging stability, the acid value is preferably 5 to 90 mgKOH / g, more preferably 10 to 80 mgKOH / g, still more 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, an electrophotographic toner excellent in charging stability can be obtained while maintaining the 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-04”, “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 "(manufactured by Orient Chemical Industries), cetyltrimethylammonium bromide," COPY CHARGE PX VP435 "(manufactured by Hoechst), etc .; polyamine resins such as" AFP-B "(manufactured by Orient Chemical Industries), etc .; imidazole derivatives For example, “PLZ-2001”, “PLZ-8001” (manufactured by Shikoku Kasei Co., Ltd.) and the like can be mentioned.

  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 charging stability 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 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 the positive chargeability of the toner, a quaternary ammonium base-containing styrene resin is preferable. Based resins are preferred.

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

(Wherein R ¹¹ represents a hydrogen atom or a methyl group)
A monomer represented by the formula (IVb):

(Wherein R ¹² represents a hydrogen atom or a methyl group, and R ¹³ represents an alkyl group having 1 to 12 carbon atoms)
And a monomer represented by formula (IVc):

(Wherein R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ and R ¹⁶ 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 ¹¹ is preferably a hydrogen atom is preferable, and as the monomer represented by the formula (IVb), R ¹² is preferably a hydrogen atom, and R ¹³ 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 ¹⁴ is a methyl group, and R ¹⁵ and R ¹⁶ are a methyl group or an ethyl group, more preferably R ¹⁴ , R ¹⁵ and R ^16. 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.

  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.

[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).

Resin production example 1 [resins A1 to A10]
Alcohol components other than the aromatic compound (I) shown in Tables 1 and 2, terephthalic acid and esterification catalyst, nitrogen introduction pipe, dehydration pipe equipped with a fractionation pipe through which 100 ° C hot water was passed, a stirrer and thermoelectric Place in a 5 liter four-necked flask equipped with a pair, keep it at 180 ° C for 1 hour in a nitrogen atmosphere, then increase the temperature from 180 ° C to 230 ° C at 10 ° C / hr, then condensation polymerization at 230 ° C for 10 hours Reacted. Furthermore, after adding aromatic compound (I) shown in Tables 1 and 2 at 180 ° C. and reacting for 5 hours, adding trimellitic anhydride shown in Tables 1 and 2 and reacting at 200 ° C., 10 kPa The reaction was carried out until the desired softening point was reached, to obtain a polyester.

Resin Production Example 2 [Resin A11, A12]
Place alcohol components other than the aromatic compound (I) shown in Table 2, terephthalic acid and esterification catalyst into a 5-liter four-necked flask equipped with a dehydration tube equipped with a nitrogen introduction tube, a stirrer and a thermocouple. Then, a condensation polymerization reaction was carried out at 230 ° C. for 10 hours under a nitrogen atmosphere, and the reaction was further carried out at 230 ° C. and 8.0 kPa for 1 hour. Furthermore, after adding aromatic compound (I) shown in Table 2 at 180 ° C. and reacting for 5 hours, adding trimellitic anhydride shown in Table 2 and reacting at 200 ° C., the desired compound at 10 kPa The reaction was carried out until the softening point was reached to obtain a polyester.

Resin Production Example 3 [Resin A13, A14]
Four alcohol components, terephthalic acid and esterification catalyst shown in Table 3 in 5 liters equipped with a nitrogen introduction tube, a dehydration tube equipped with a fractionation tube through which hot water of 100 ° C. was passed, a stirrer and a thermocouple The flask was placed in a neck flask, kept at 180 ° C. for 1 hour in a nitrogen atmosphere, then heated from 180 ° C. to 230 ° C. at 10 ° C./hr, and then subjected to a condensation polymerization reaction at 230 ° C. for 10 hours. Furthermore, trimellitic anhydride shown in Table 3 was added, reacted at 200 ° C., and reacted at 10 kPa until a desired softening point was reached, thereby obtaining a polyester.

Resin Production Example 4 [Resin A15, A16]
The alcohol component, terephthalic acid and esterification catalyst shown in Table 3 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 at 230 ° C. under a nitrogen atmosphere. The polycondensation reaction was performed for 10 hours, and the reaction was further performed at 230 ° C. and 8.0 kPa for 1 hour. Furthermore, trimellitic anhydride shown in Table 3 was added, reacted at 200 ° C., and reacted at 10 kPa until a desired softening point was reached, thereby obtaining a polyester.

Resin Production Example 5 [Resin H1]
Polyester raw material monomers other than trimellitic anhydride and aromatic compound (I) and esterification catalyst shown in Table 4 are equipped with a nitrogen introduction pipe, a dehydration pipe equipped with a fractionation pipe through which hot water of 100 ° C is passed, and a stirrer. And a 5 liter four-necked flask equipped with a thermocouple, and heated to 160 ° C. in a nitrogen atmosphere. Thereafter, a mixture of the both reactive monomers shown in Table 4, the raw material monomer of the vinyl resin, and the polymerization initiator was added dropwise over 1 hour with a dropping funnel. After the dropwise addition, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C., followed by condensation polymerization reaction at 230 ° C. for 10 hours, and further reaction at 230 ° C. and 8.0 kPa for 1 hour. After cooling to 180 ° C., the aromatic compound (I) shown in Table 4 was added at 180 ° C. and reacted for 5 hours. Finally, trimellitic anhydride shown in Table 4 was added, and 200 ° C., 10 kPa. The reaction was carried out until the desired softening point was reached, to obtain a hybrid resin.

Resin Production Example 6 [Resin H2]
The raw material monomers of polyester other than trimellitic anhydride and aromatic compound (I) and the esterification catalyst shown in Table 4 are divided into four 5 liters equipped with a dehydration tube equipped with a nitrogen introduction tube, a stirrer and a thermocouple. The flask was placed in a neck flask and heated to 160 ° C. under a nitrogen atmosphere. Thereafter, a mixture of the both reactive monomers shown in Table 4, the raw material monomer of the vinyl resin, and the polymerization initiator was added dropwise over 1 hour with a dropping funnel. After the dropwise addition, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C., followed by condensation polymerization reaction at 230 ° C. for 10 hours, and further reaction at 230 ° C. and 8.0 kPa for 1 hour. Further, the aromatic compound (I) shown in Table 4 was added at 180 ° C. and reacted for 5 hours, and then trimellitic anhydride shown in Table 4 was added and reacted at 200 ° C., and desired at 10 kPa. The reaction was conducted until the softening point was reached to obtain a hybrid resin.

Examples 1 to 21 and Comparative Examples 1 and 2
100 parts by weight of a binder resin, a colorant, a charge control agent, a release agent, and a charge control resin (only in Example 19) shown in Table 5 were mixed with 2.0 parts by weight 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.

  External additives shown in Table 5 were added to 100 parts by weight of the obtained toner particles and mixed with a Henschel mixer to obtain a toner.

  The raw materials listed in Table 5 are as follows.

[Colorant]
A: Black pigment “Regal 330R” (manufactured by Cabot), carbon black B: Cyan pigment “ECB-301” (manufactured by Dainichi Seika), Pigment Blue 15: 3
C: Magenta pigment “Super Magenta R” (Dainippon Ink Chemical Co., Ltd.), Pigment Red 122
D: Yellow pigment “Paliotol Yellow D1155” (manufactured by BASF), Pigment Yellow 185

[Charge control agent]
A: Negatively chargeable charge control agent “Bontron S-34” (azo chemical compound, manufactured by Orient Chemical Co., Ltd.)
B: Positively chargeable charge control agent “Bontron N-04” (manufactured by Orient Chemical Co., Ltd.)
C: Negatively chargeable charge control agent “LR-147” (manufactured by Nippon Carlit)

〔Release agent〕
A: Polypropylene wax “NP-105” (manufactured by Mitsui Chemicals), melting point: 140 ° C.

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

(External additive)
A: “Aerosil R-972” (manufactured by Nippon Aerosil Co., Ltd.), average particle size: 16 nm, hydrophobizing agent: DMDS
B: Hydrophobic silica “TG-C243” (manufactured by Cabot), average particle size: 100 nm, hydrophobizing agent: OTES + HMDS)

Test Example 1 [low temperature fixability]
An apparatus in which the fixing machine of the copying machine “AR-505” (manufactured by Sharp Corporation) is improved so that fixing can be performed outside the apparatus (however, only in the evaluation of Example 19, the non-magnetic one-component developing system printer “HL” -2040 "(manufactured by Brother Kogyo Co., Ltd.) was changed to a modified device), and toner was mounted to obtain an unfixed image. 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 5. 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 [Preservation]
4 g of toner was 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 5.

〔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 [Charging stability under high temperature and high humidity]
Under conditions of a temperature of 32 ° C. and a relative humidity of 85%, 0.6 g of toner and a silicone ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size: 90 μm) (however, only in the evaluation of Example 19, the carrier is a ferrite carrier (P -01: Japan Imaging Society standard product, average particle size: 70μm) 19.4g was placed in a 50ml plastic bottle and mixed at 250r / min using a ball mill. Measurement was performed using a Q / M meter (EPPING).

  After a specified mixing time, a specified amount of toner and carrier mixture is put into the cell attached to the Q / M meter, and only the toner is sucked for 90 seconds through a 32 μm sieve (stainless steel, twill, wire diameter: 0.0035 mm). did. The change in voltage on the carrier generated at that time was monitored, and the value of [total amount of electricity after 90 seconds (μC) / amount of attracted toner (g)] was defined as the charge amount (μC / g). Calculate the ratio of charge amount after mixing time of 180 seconds and charge amount after mixing time of 1200 seconds (charge amount after mixing time of 1200 seconds / charge amount after mixing time of 180 seconds) and charge stability according to the following evaluation criteria Was evaluated. The results are shown in Table 5.

〔Evaluation criteria〕
A: 0.8 or more B: 0.6 or more, less than 0.8 C: less than 0.6

  From the above results, the toners of Examples 1 to 21 containing the binder resin obtained by using a specific aromatic compound were compared with the toners of Comparative Examples 1 and 2, and the low-temperature fixability and storage of the toner were compared. It can be seen that the property is good and the charging stability under high temperature and high humidity is also excellent.

  The polyester resin for toner of the present invention is suitably used as a binder resin for toners used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like.

Claims (4)

An electrophotographic toner comprising a polyester-based binder resin for toner obtained by condensation polymerization of a carboxylic acid component and an alcohol component, wherein the toner is represented by the formula (I):

(Wherein, R ¹ and R ² each independently represent a hydrogen atom or a hydroxyl group, and X is —COOR ³ (R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) or —CH _2. OH, except that R ¹ and R ² are both hydrogen atoms.)
The in aromatic compounds represented, as the carboxylic acid component and / or the alcohol component, the total amount of the acid component and alcohol component, obtained using 2.5 to 25 mol%, it contains a polyester-based binder resin for toner An electrophotographic toner. Aromatic compound represented by the formula (I) comprises at least one of coumaric acid and caffeic acid, claim 1 Symbol placement electrophotographic toner over the. Aromatic compound represented by the formula (I) comprises the door at least any one selected from at least one and coumaryltryptophan alcohol and café-yl alcohol selected from coumaric acid and caffeic acid, claim 1 Symbol placement electrophotography use toner over. Alcohol component containing an aliphatic diol, claim 1-3 electrophotographic toner over according any.