JP2008224961A - Electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic toner which obtains stable image density even under high temperature and high humidity, and is excellent in low-temperature fixing performance, hot-offset resistance and durability. <P>SOLUTION: The electrophotographic toner contains a binder resin including a composite resin having a condensation polymerization type resin portion and an addition polymerization type resin portion and is obtained by a fusion crushing method, wherein the condensation polymerization type resin portion has a constitutional unit originated from a carboxylic acid component containing at least two kinds of alkyl succinic acid which has alkyl group of the number of carbon of 9 to 14, having branched chain and/or at least two kinds of alkenyl succinic acid which has alkenyl group of the number of carbon of 9 to 14, having branched chain. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic toner used for electrophotography, electrostatic recording, electrostatic printing, and the like.

In recent years, from the pursuit of high image quality, development of a small particle size toner excellent in fixability has been desired.
As the binder resin used for the toner, styrene-acrylic resin, polyester, and the like are known, but polyester is used because of its excellent durability and fixability. As a toner using such a polyester, in particular, from the viewpoint of fixability, a toner by a melt-kneading pulverization method using a polyester containing an alkyl succinic acid or alkenyl succinic acid having 10 or more carbon atoms as a carboxylic acid component as a binder resin is used. It is disclosed (for example, Patent Document 1 and Patent Document 2).

JP-A-57-109825 JP 2000-35695 A

However, the above toner has not been sufficient from the viewpoint of image stability under high temperature and high humidity, low temperature fixability, offset resistance, durability, and the like.
The present invention provides a toner for electrophotography which can obtain a stable image density under high temperature and high humidity, and is excellent in low temperature fixing property, offset resistance and durability.

The present invention relates to an electrophotographic toner containing a binder resin including a composite resin having a condensation polymerization resin unit and an addition polymerization resin unit, and obtained by a melt pulverization method, wherein the condensation polymerization resin unit comprises: , Containing at least two kinds of alkyl succinic acid having a branched chain alkyl group having 9 to 14 carbon atoms and / or at least two kinds of alkenyl succinic acid having a branched chain alkyl group having 9 to 14 carbon atoms. An electrophotographic toner having a structural unit derived from a carboxylic acid component;
About.

  According to the present invention, a stable image density can be obtained even under high temperature and high humidity, and an electrophotographic toner excellent in low temperature fixability, hot offset resistance and durability can be provided.

  The toner for electrophotography of the present invention contains a binder resin containing a composite resin having a condensation polymerization resin unit and an addition polymerization resin unit (hereinafter sometimes referred to as “binder resin of the present invention”), An electrophotographic toner obtained by a melt pulverization method, wherein the condensation polymerization resin unit comprises at least two kinds of alkyl succinic acid having a branched chain alkyl group having 9 to 14 carbon atoms and / or a branched chain. It has a structural unit derived from a carboxylic acid component containing at least two alkenyl succinic acids having an alkenyl group having 9 to 14 carbon atoms. The toner for electrophotography of the present invention is excellent in low temperature fixability, hot offset resistance, durability, stability of image density under high temperature and high humidity, etc. due to the above configuration, and all the above characteristics. Is excellent.

Binder Resin of the Present Invention The binder resin of the present invention includes a composite resin having a condensation polymerization resin unit and an addition polymerization resin unit. In particular, there are many types of condensation polymerization resin units in terms of molecular structure. It has a structural unit derived from a carboxylic acid component containing alkyl succinic acid and / or alkenyl succinic acid composed of structural isomers of By having such a structural unit, the steric hindrance in the vicinity of the ester bond increases, thereby increasing the hydrophobicity of the resin, and a stable image density can be obtained even under high temperature and high humidity. Further, by having an alkyl distribution, the molecular weight distribution of the polyester is widened, and a low molecular weight component effective for low-temperature fixing, a hot offset, and a high molecular weight component effective for durability can be simultaneously contained in the polymer.

  From the viewpoint of the hydrophobicity and molecular weight distribution of the resin, the alkyl succinic acid is composed of at least two types of alkyl succinic acid having a branched chain alkyl group having 9 to 14 carbon atoms, and the alkenyl succinic acid is a carbon having a branched chain. It consists of at least two, preferably at least three, alkenyl succinic acids having several 9 to 14 alkenyl groups. In the present invention, the carboxylic acid component contains the alkyl succinic acid and alkenyl succinic acid, but preferably contains at least two alkyl succinic acids and / or at least two alkenyl succinic acids. Specific examples of the alkyl group or alkenyl group having 9 to 14 carbon atoms having a branched chain include isododecenyl group and isododecyl group. By using such a carboxylic acid component containing an alkyl succinic acid having an alkyl group having a different carbon number and / or an alkenyl succinic acid having an alkenyl group having a different carbon number, the molecular weight of the resulting polyester is expanded, and the polyester For example, since the endothermic peak in the vicinity of the glass transition point in differential scanning calorimetry (DSC) is broad, the toner containing the toner exhibits the effect of having a very wide fixing region, low temperature fixing, offset resistance, and durability. There is a surprising effect that the opposite characteristics of sex can be achieved.

From the viewpoint of the hydrophobicity and molecular weight distribution of the resin, the alkyl succinic acid preferably contains a structural isomer of alkyl succinic acid derived from an alkyl group having a branched chain having 9 to 14 carbon atoms. It is preferable to contain a structural isomer of alkenyl succinic acid derived from an alkenyl group having a branched chain having 9 to 14 carbon atoms. From the same viewpoint, the alkyl succinic acid and / or alkenyl succinic acid preferably contains 20 or more structural isomers, more preferably 25 or more, and still more preferably 30 or more.
In the present invention, the structural isomers of alkyl succinic acid and alkenyl succinic acid derived from the above alkyl group or alkenyl group are treated as different alkyl succinic acids or alkenyl succinic acids.

  From the viewpoint of the hydrophobicity and molecular weight distribution of the resin, the alkyl succinic acid and / or alkenyl succinic acid is preferably obtained from a compound having an alkylene group (an alkylene compound) and maleic acid and / or fumaric acid. More preferably, it is obtained from an alkylene compound and maleic acid. As the alkylene compound, those having 9 to 14 carbon atoms are preferable. Specifically, alkylene compounds obtained from ethylene, propylene, isobutylene, normal butylene and the like, for example, trimers and tetramers such as ethylene, propylene, isobutylene and normal butylene, etc. Etc. are preferably used. In addition, in the gas chromatography mass spectrometry, the alkylene compound preferably has 20 or more peaks corresponding to the alkylene compound having 9 to 14 carbon atoms, more preferably 25 or more, and even more preferably 30 under the measurement conditions described later. Have more.

These peaks observed in gas chromatography mass spectrometry are considered to be derived from structural isomers of alkylene compounds. Alkyl succinic acid and alkenyl succinic acid produced from raw materials of alkylene compounds having a certain number of structural isomers. Are also found to have similar structural isomers. Polyesters obtained from alkyl succinic acid and / or alkenyl succinic acid having a certain number or more of these structural isomers are highly hydrophobic due to their extremely high steric hindrance, and toners containing this polyester can be used under high temperature and high humidity. The image density stability is further improved. Moreover, since the molecular weight distribution of the obtained resin is expanded by containing a plurality of types of isomers, the low-temperature fixability and the hot offset resistance are further improved. In addition, from the viewpoint of the object of the present invention, it is preferable that the number of peaks is large, but the upper limit is naturally limited due to limitations of mathematical combinations.

Alkyl succinic acid and / or alkenyl succinic acid can be obtained by using the ene reaction by mixing the known alkylene compound with maleic acid and / or fumaric acid and heating, but is easy to manufacture. From the viewpoint of the above, a method obtained by mixing the known alkylene compound and maleic acid and heating to utilize the ene reaction is preferable. In order to obtain an alkyl succinic acid having a C 9-14 alkyl group having a branched chain and / or an alkenyl succinic acid having a C 9-14 alkenyl group having a branched chain, any known method may be used. it can. For example, selection of the raw material or catalyst type of the alkylene compound used in the synthesis of the alkylene compound, a method of adjusting the reaction rate, reaction time, reaction pressure, solvent, etc., and production of alkyl succinic acid and / or alkenyl succinic acid Any of the methods for adjusting the distillation conditions can be used (see JP-A-48-23405, JP-A-48-23404, US Pat. No. 3,374,285, etc.).

Suitable raw materials used for the synthesis of the alkylene compound include propylene and isobutylene which are alkylene compounds having a branched chain, and propylene having a small molecular weight is more preferable from the viewpoint of increasing the number of structural isomers.
Suitable catalysts used for the synthesis of the alkylene compound include liquid phosphoric acid, solid phosphoric acid, tungsten, boron trifluoride complex and the like. In addition, from the viewpoint of easy control of the number of structural isomers, a method of adjusting by distillation conditions (for example, temperature) after random polymerization is preferable.

  The binder resin of the present invention includes a composite resin having a condensation polymerization resin unit and an addition polymerization resin unit. Here, “a composite resin having a condensation polymerization resin unit and an addition polymerization resin unit”. The term “resin” means a resin obtained by polymerizing at least a raw material monomer of a condensation polymerization resin and a raw material monomer of an addition polymerization resin. Specifically, the resin is selected from an alcohol component, alkyl succinic acid and alkenyl succinic acid. It is obtained by polymerizing a raw material monomer of a condensation polymerization resin containing a carboxylic acid component containing at least one kind and a raw material monomer of an addition polymerization resin.

  The polycondensation resin generally refers to a resin obtained by removing low molecular components such as water and alcohol during the reaction. In the present invention, the polycondensation resin is a group consisting of polyester, polyester / polyamide and polyamide. At least one selected from these is preferred, and among these, polyester is more preferred from the viewpoint of low-temperature fixability and durability. The raw material monomer of the condensation polymerization resin is a monomer used as a raw material for the polymerization of the condensation polymerization resin, and constitutes at least a part of the structural unit of the resin.

When the condensation polymerization resin unit contains polyester, the content of the polyester is preferably 60% by weight or more, more preferably 70% by weight or more in the condensation polymerization resin unit, from the viewpoints of fixability and durability. The polyester is preferably an alcohol component as a raw material monomer, and a carboxylic acid component containing at least one selected from alkyl succinic acid and alkenyl succinic acid. It can be obtained by condensation polymerization.
Examples of the alcohol component include polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane, alkylene oxide adducts of bisphenol A such as polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane, ethylene glycol Diols such as 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, bisphenol A, hydrogenated bisphenol A; Examples include trihydric or higher polyhydric alcohols such as sorbitol, pentaerythritol, glycerol, and trimethylolpropane. Among these, an alkylene oxide adduct of bisphenol A which is an aromatic alcohol is preferable from the viewpoint of chargeability.

  The total content of alkyl succinic acid and alkenyl succinic acid in the carboxylic acid component, which is a raw material monomer of polyester obtained by condensation polymerization of the alcohol component and the carboxylic acid component, is the hydrophobicity of the resin, that is, the high temperature of the toner. From the viewpoints of image stability under humidity, toner fixability, and storage stability, 3 to 50 mol% is preferable, and 4 to 45 mol% is more preferable. 5-43 mol% is still more preferable.

In the present invention, a divalent or trivalent or higher carboxylic acid component other than alkyl succinic acid and alkenyl succinic acid can be used as the carboxylic acid component. Examples of the divalent carboxylic acid include phthalic acid, isophthalic acid, Aromatic dicarboxylic acids such as terephthalic acid; oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, alkyl groups having 1 to 7 or more carbon atoms or carbon Examples thereof include aliphatic dicarboxylic acids such as succinic acid substituted with alkenyl groups of 2 to 7 or 15; their acid anhydrides and alkyl (carbon number of 1 to 3) esters of these acids. Among these, aromatic dicarboxylic acid compounds are preferable from the viewpoints of toner durability, fixability, and dispersibility of colorants. Among the aromatic dicarboxylic acid compounds, terephthalic acid and isophthalic acid are preferable from the viewpoints of chargeability and fixability of the toner.

Examples of the trivalent or higher polyvalent carboxylic acid compounds include aromatic carboxylic acids such as 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, and Derivatives such as these acid anhydrides and alkyl (C1-C3) esters are mentioned. Of these, trimellitic acid and its acid anhydride are preferred from the viewpoint of being inexpensive and easy to control the reaction.
In addition, carboxylic acid, anhydride of carboxylic acid, and alkyl ester of carboxylic acid may be collectively referred to as a carboxylic acid compound in the present specification.

The condensation polymerization of the alcohol component and the carboxylic acid component is preferably performed in the presence of an esterification catalyst. Examples of the esterification catalyst suitably used for the condensation polymerization include dioctyltin oxide, dibutyltin oxide, titanium compound, tin (II) compound having no Sn-C bond, and the like. Of these, titanium compounds that exhibit the above effect more significantly, and tin (II) compounds having no Sn—C bond are preferred. These can be used alone or in combination of two or more.
As a titanium compound, the titanium compound which has a Ti-O bond is preferable, and the compound which has a C1-28 total carbon number alkoxy group, an alkenyloxy group, or an acyloxy group is more preferable.

Specific examples of titanium compounds include titanium diisopropylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₃ H ₇ O) ₂ ], titanium diisopropylate bisdiethanolamate [Ti (C ₄ H ₁₀ O ₂ N) ₂ (C ₃ H ₇ O) ₂ ], titanium dipentylate 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) 1 (} C 3 ₇ O) _3], titanium monopropylate tris (triethanolaminate) _{[Ti (C 6 H 14 O 3} N) 3 (C 3 H 7 O) 1 ], and the like, titanium diisopropylate Among these Preferred are rate bistriethanolamate, titanium diisopropylate bisdiethanolamate, and titanium dipentylate bistriethanolamate, which are also commercially available, for example, from Matsumoto Trading Co., Ltd.

Specific examples of other preferred titanium compounds include tetra-n-butyl titanate [Ti (C ₄ H ₉ O) ₄ ], tetrapropyl titanate [Ti (C ₃ H ₇ O) ₄ ], tetratearyl titanate [Ti (C ₁₈ H ₃₇ O) ₄ ], tetramyristyl titanate [Ti (C ₁₄ H ₂₉ O) ₄ ], tetraoctyl titanate [Ti (C ₈ H ₁₇ O) ₄ ], dioctyl dihydroxyoctyl titanate [Ti (C ₈ H ₁₇ O) ₂ (OHC ₈ H ₁₆ O) ₂ ], dimyristyl dioctyl titanate [Ti (C ₁₄ H ₂₉ O) ₂ (C ₈ H ₁₇ O) ₂ ] and the like. Among these, tetrastearyl titanate, Tetramyristyl titanate, tetraoctyl titanate and dioctyl dihydroxy octyl titanate are preferred, such as reacting a titanium halide with the corresponding alcohol. However, it is also available as a commercial product such as Nisso.

Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having a Sn—O bond, a tin (II) compound having a Sn—X (X represents a halogen atom) bond, and the like. Preferred examples include tin (II) compounds having Sn-O bonds.
Examples of the tin (II) compound having a Sn-O bond include tin (II) oxalate, tin (II) acetate, tin (II) octoate, tin (II) laurate, tin (II) stearate, and oleic acid. Tin (II) carboxylate having a carboxylic acid group having 2 to 28 carbon atoms such as tin (II); carbon such as octyloxytin (II), lauroxytin (II), stearoxytin (II), dioleoxytin (II), etc. Dialkoxytin (II) having an alkoxy group of 2 to 28; tin (II) oxide; tin (II) sulfate and the like having Sn—X (X represents a halogen atom) bond includes tin chloride. (II), tin (II) halides such as tin (II) bromide, and the like. Among these, (R ¹ COO) ₂ Sn (where R ¹ fatty acid tin is represented by an alkyl or alkenyl group 5 to 19 carbon ^{atoms) (II), (R 2} O) 2 Sn ( wherein R ² is also alkyl group having 6 to 20 carbon atoms Alkoxy tin (II) and tin oxide represented by SnO (II) is preferably represented by an alkenyl group), (R ¹ COO) fatty tin represented by ₂ Sn (II) and tin oxide (II) Are more preferred, and tin (II) octoate, tin (II) stearate and tin (II) oxide are more preferably used.
The titanium compound and tin (II) compound can be used in combination of two or more thereof.

The amount of the esterification catalyst present is preferably 0.01 to 1.0 part by weight, more preferably 0.1 to 0.6 part by weight based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.
The polycondensation of the alcohol component and the carboxylic acid component can be performed, for example, at a temperature of 180 to 250 ° C. in an inert gas atmosphere in the presence of the esterification catalyst.

  In the present invention, polyester includes not only polyester but also polyester modified to such an extent that its properties are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. And a composite resin having two or more kinds of resin units including a polyester unit.

Polyester and polyamide listed as polycondensation resin, using the raw material monomer for forming the amide component in addition to the alcohol component and carboxylic acid component mentioned as the raw material monomer of the above ester, polycondensation these raw material monomers Can be obtained. Further, the polyamide can be obtained by using a raw material monomer for forming an amide component in addition to the carboxylic acid component mentioned as the raw material monomer for the ester, and subjecting these raw material monomers to condensation polymerization.
Examples of the raw material monomer used to form the amide component include various known polyamines, aminocarboxylic acids, aminoalcohols, etc., preferably hexamethylenediamine and ε-caprolactam.

The polycondensation reaction conditions for each of the above polycondensation resins can be appropriately determined based on the conventionally known polycondensation reaction conditions according to the raw material monomers, the type of the target resin, and the like.
The above-mentioned raw material monomers include those normally classified as ring-opening polymerization monomers, but these are hydrolyzed by condensation in the presence of water or the like produced by the condensation polymerization reaction of other monomers. Therefore, in the present invention, it can be included in the raw material monomer of the condensation polymerization resin.

The addition polymerization resin generally means a resin obtained by a reaction in which an addition reaction is repeated and a new active site is generated at the same time as the formation of a covalent bond. The addition polymerization resin is a vinyl resin obtained by a radical polymerization reaction. Based resins and the like. Moreover, the raw material monomer of the addition polymerization resin is a monomer used as a raw material for the polymerization of the addition polymerization resin, and constitutes at least a part of the structural unit of the resin.
As raw material monomers for vinyl resins, styrenes 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) esters of (meth) acrylic acid, esters of ethylenic monocarboxylic acids such as dimethylaminoethyl (meth) acrylate; vinyl ethers such as vinyl methyl ether Vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinylpyrrolidone, and the like. Among these, styrene is used from the viewpoint of chargeability, and from the viewpoint of adjustment of fixing property and glass transition point ( Alkyl (carbon number 1-18) esters of (meth) acrylic acid are preferred, More preferred is at least one selected from styrene, 2-ethylhexyl acrylate, butyl acrylate, and long-chain alkyl (carbon number 12 to 18) esters of acrylic acid. In this specification, “(meth) acrylic acid” includes both acrylic acid and methacrylic acid.

When the raw material monomer of the vinyl resin contains styrene and an alkyl ester of (meth) acrylic acid, the content of styrene is preferably 50 to 90% by weight, and 75 to 85% by weight in the raw material monomer of the vinyl resin. Is more preferable. The monomer ratio of styrene to the alkyl ester of (meth) acrylic acid (styrene / (meth) acrylic acid alkyl ester) is preferably 50/50 to 95/5, more preferably 70/30 to 95/5 in weight ratio. .
In addition, a polymerization initiator, a crosslinking agent, or the like may be used as necessary for the addition polymerization of the raw material monomer of the vinyl resin. The addition polymerization conditions for the addition polymerization resin can be appropriately determined based on conventionally known addition polymerization reaction conditions depending on the raw material monomer, the type of the target resin, and the like.

  In the present invention, the weight ratio of the condensation polymerization resin unit to the addition polymerization resin unit (condensation polymerization resin unit / addition polymerization resin unit) is approximately the raw material monomer of the addition polymerization resin of the condensation polymerization resin raw material monomer. Is equivalent to the weight ratio. In the present invention, the weight ratio of the raw material monomer of the polymerization resin to the raw material monomer of the addition polymerization resin (the raw material monomer of the condensation polymerization resin / the raw material monomer of the addition polymerization resin) is determined by the low temperature fixability and storage stability of the toner In this respect, since the continuous phase is preferably a condensation polymerization resin and the dispersed phase is an addition polymerization resin, 50/50 to 95/5 is preferable, and 60/40 to 95/5 is more preferable.

In addition to the condensation polymerization resin raw material monomer and the addition polymerization resin raw material monomer, the composite resin having the above condensation polymerization resin unit and the addition polymerization resin unit further includes the above condensation polymerization resin raw material monomer and addition polymerization. A resin (hybrid resin) obtained by using a compound (both reactive monomers) capable of reacting with any of the raw material monomers of the resin is preferable.
As the both reactive monomers, at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group and a secondary amino group in the molecule, and an ethylenically unsaturated bond A compound having the above formula is preferred, and by using such a bireactive monomer, the dispersibility of the resin to be the dispersed phase can be further improved. Specific examples of both reactive monomers include acrylic acid, fumaric acid, methacrylic acid, citraconic acid, maleic acid, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, or anhydrides of these carboxylic acids. Derivatives such as alkyl (1 to 2 carbon atoms) esters and the like are mentioned, and among these, acrylic acid, fumaric acid, methacrylic acid, maleic acid or derivatives of these carboxylic acids are preferable from the viewpoint of reactivity. The above-mentioned both reactive monomers can be used alone or in combination of two or more.
The amount of both reactive monomers used is preferably from 0.1 to 10 mol%, more preferably from 1 to 8 mol%, based on the total amount of the carboxylic acid component, from the viewpoint of compatibility between the condensation polymerization resin unit and the addition polymerization resin unit. . In addition, a carboxylic acid component contains this, when the said both reactive monomer is a carboxylic acid compound.

  In the present invention, the progress and completion of the polycondensation reaction and the addition polymerization reaction may be appropriately selected in accordance with the respective reaction mechanisms, and the reaction may proceed and be completed, and are not necessarily simultaneous in time. There is no need. For example, the raw material monomer of the condensation polymerization resin, the raw material monomer of the addition polymerization resin, the bireactive monomer, etc. are mixed, and the addition is first performed mainly at a temperature condition suitable for the addition polymerization reaction, for example, 50 to 180 ° C. After forming an addition polymerization resin having a functional group capable of condensation polymerization by polymerization reaction, the reaction temperature is then raised to a temperature condition suitable for the condensation polymerization reaction, for example, 190 to 270 ° C. A method of forming a polycondensation resin by reaction is mentioned.

In addition, the raw material monomer of the polycondensation resin is subjected to a polycondensation reaction at a temperature condition suitable for the polycondensation reaction, for example, 190 to 270 ° C., and then the addition monomer of the addition polymerization resin, the bireactive monomer, and the polymerization initiator A method of adding a mixed solution such as the above and reacting at a temperature suitable for the addition polymerization reaction, for example, at 50 to 180 ° C. is also included. In this case, after the addition polymerization reaction, the condensation polymerization reaction can also be performed under a temperature condition suitable for the above condensation polymerization reaction.
The reaction time for obtaining the binder resin of the present invention is usually 20 to 40 hours in total.
The binder resin of the present invention comprises a polycondensation resin raw material monomer and an addition polymerization resin raw material monomer, and if necessary, in addition to these, both reactive monomers are mixed in advance, so that a polycondensation reaction and an addition polymerization reaction are performed. Can also be obtained in parallel in the same reaction vessel.

Further, the binder resin of the present invention may contain a release agent from the viewpoint of toner fixability. As release agents, low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene / polyethylene copolymer, aliphatic hydrocarbon waxes such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and oxide fatty acid amides thereof, Fatty acids, higher alcohols, fatty acid metal salts and the like can be mentioned, and among these, aliphatic hydrocarbon waxes are preferable from the viewpoint of releasability and stability.
Examples of the method of incorporating a release agent in the binder resin include a method of polymerizing the raw material monomer of the condensation polymerization resin and the raw material monomer of the addition polymerization resin in the presence of the release agent.
From the viewpoint of toner durability, the binder resin of the present invention preferably contains 50% by weight or more of the composite resin, more preferably 80% by weight or more, and still more preferably 100% by weight.

The molecular weight of the binder resin of the present invention is not particularly limited as long as it can be used as a binder resin for toner, but is usually 1,000 to 10,000, preferably 1,500 to 8, in terms of number average molecular weight. 000, more preferably 2,000 to 4,000.
The softening point and glass transition point should be easily adjusted by adjusting the raw material monomer composition and ratio, polymerization initiator, molecular weight, catalyst amount, etc., or by selecting reaction conditions such as increasing the reaction time to increase the softening point. 70 to 165 ° C. is preferable, and the glass transition point is preferably 40 to 85 ° C., more preferably 45 to 75 ° C., and still more preferably 50 to 70 ° C. from the viewpoints of fixability and durability.
The acid value is preferably 6 to 35 mgKOH / g. The desired softening point and acid value can be obtained by adjusting the charging ratio of alcohol and carboxylic acid, the temperature of condensation polymerization, and the reaction time.

Electrophotographic Toner The electrophotographic toner of the present invention contains a binder resin containing a composite resin having the condensation polymerization resin unit and the addition polymerization resin unit, and is obtained by a melt pulverization method.
In the present invention, the carboxylic acid component derived from the branched chain alkyl succinic acid having 9 to 14 carbon atoms and / or the branched chain alkenyl succinic acid having 9 to 14 carbon atoms. Is preferably contained in the toner of the present invention in an amount of 1 to 30% by weight, more preferably 3 to 20% by weight, from the viewpoint of image density stability under high temperature and high humidity.
In the electrophotographic toner of the present invention, the binder resin of the present invention is further filled with a release agent, a colorant, a charge control agent, a conductivity adjusting agent, an extender pigment, a fibrous substance, etc., if necessary. Additives such as agents, antioxidants, and anti-aging agents may be added as appropriate.

The release agent is preferably contained from the viewpoint of offset resistance, and examples of the release agent include carnauba wax, rice wax, and candelilla wax in addition to the release agent that can be contained in the binder resin described above. Plant waxes such as tree wax and jojoba oil; animal waxes such as beeswax; montan wax and the like. These can be used alone or in combination of two or more. The melting point of the release agent is preferably 60 to 140 ° C., more preferably 60 to 100 ° C., from the viewpoints of toner fixing properties and offset resistance.
The content of the release agent is preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of dispersibility in the binder resin. More preferably, it is 5 to 7 parts by weight.

Moreover, there is no restriction | limiting in particular as a coloring agent, A well-known coloring agent is mentioned, According to the objective, it can select suitably. Specifically, carbon black, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, balkan orange, watch young red, permanent red, brilliantamine 3B, brilliantamine 6B, dupont oil Various pigments and acridines such as red, pyrazolone red, resol red, rhodamine B lake, lake red C, bengal, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate , Xanthene, azo, benzoquinone, azine, anthraquinone, indico, thioindico, phthalose Nin-based, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazine, various dyes thiazole, etc. may be used in conjunction with one or more kinds.
The content of the colorant is preferably 25 parts by weight or less, more preferably 0.01 to 10 parts by weight, with respect to 100 parts by weight of the binder resin, from the viewpoint of coloring power and image transparency. Preferably it is 3-10 weight part.

Examples of charge control agents include benzoic acid metal salts, salicylic acid metal salts, alkyl salicylic acid metal salts, catechol metal salts, metal-containing bisazo dyes, tetraphenylborate derivatives, quaternary ammonium salts, alkylpyridinium salts, and the like. Can be mentioned.
The content of the charge control agent is preferably 10 parts by weight or less, and more preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the binder resin.

The volume median particle size (D ₅₀ ) of the electrophotographic toner of the present invention is preferably from 3 to 15 μm, more preferably from 4 to 9 μm, from the viewpoints of high image quality and productivity. 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.
Further, the softening point of the toner is preferably from 80 to 160 ° C., more preferably from 80 to 150 ° C., and further preferably from 90 to 140 ° C. from the viewpoint of low-temperature fixability. Moreover, 45-80 degreeC is preferable from the same viewpoint, and, as for a glass transition point, 50-70 degreeC is more preferable.
The toner of the present invention is obtained by a melt pulverization method, which will be described later.

  The method for producing an electrophotographic toner of the present invention includes a step of melt-kneading a binder resin including a composite resin having at least a condensation polymerization resin unit and an addition polymerization resin unit, and (b) the obtained kneaded product. The polycondensation-based resin unit has at least two kinds of alkyl succinic acid having a branched chain alkyl group having 9 to 14 carbon atoms and / or 9 to 14 carbon atoms having a branched chain. It has a structural unit derived from a carboxylic acid component containing at least two alkenyl succinic acids having an alkenyl group. The binder resin including the composite resin having the condensation polymerization resin unit and the addition polymerization resin unit is the same as that described in the description of the electrophotographic toner. The other raw material components are also as described above.

The electrophotographic toner of the present invention is obtained by a melt pulverization method. Although there is no restriction | limiting in particular as a method of manufacturing a toner by a melt-pulverization method, Preferably, it has the said process (a) and process (b). Specifically, for example, after the binder resin and a release agent, a colorant, a charge control agent, and the like used as necessary are uniformly mixed with a mixer such as a ball mill, a sealed kneader, a single screw or A step of melt-kneading with a twin-screw extruder or the like, and a step of pulverizing the melt-kneaded product with a jet-type pulverizer such as a fluidized bed jet mill or an air-flow type jet mill, or a mechanical pulverizer such as a turbo mill. Further, it has a step of cooling if necessary before the pulverization and classifying as necessary after the pulverization. Any of the methods usually used in the melt pulverization method can be adopted for the cooling, pulverization and classification.
Commercially available extrusion kneaders used in the present invention include a KTK type twin screw extruder (manufactured by Kobe Steel), a TEM type twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), and a PCM twin screw extruder (manufactured by Ikekai Tekko Co., Ltd.). Among these, a PCM twin screw extruder (manufactured by Ikekai Tekko Co., Ltd.) is preferable from the viewpoint of the dispersibility of the raw materials.
In the present invention, an airflow jet mill is suitably used as the pulverizer, and commercially available products include “IDS” series manufactured by Nippon Pneumatic Co., Ltd. from the viewpoint of reducing the toner particle size.

Furthermore, a fluidity improver such as hydrophobic silica may be added as an external additive to the coarsely pulverized product in the production process or the surface of the obtained toner, if necessary. External additives include known fine particles such as silica fine particles, titanium fine particles, alumina fine particles, cerium oxide fine particles, carbon black and other inorganic fine particles, and polymer fine particles such as polycarbonate, polymethyl methacrylate and silicone resin. Can be used.
The number average particle diameter of the external additive is preferably 4 to 200 nm, more preferably 8 to 30 nm. The number average particle diameter of the external additive is determined using a scanning electron microscope or a transmission electron microscope.
The amount of the external additive is preferably 0.8 to 5.0 parts by weight, more preferably 1.0 to 5.0 parts by weight, with respect to 100 parts by weight of the toner before processing with the external additive. 5 to 3.5 parts by weight are more preferable.
The electrophotographic toner of the present invention can be used as a one-component developer or a two-component developer mixed with a carrier.

Hereinafter, the present invention will be described more specifically with reference to examples and the like. In the following examples and the like, each property value was measured and evaluated by the following method.
1. Acid value of resin Measured based on the method of JIS K0070. However, only the measurement solvent was changed to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)) from a mixed solvent of ethanol and ether specified in JIS K0070.

2. 1. Softening point and glass transition point of resin (1) Softening point Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample was heated at a heating rate of 6 ° C./min and a load of 1.96 MPa was applied by a plunger. And extruded from a nozzle having 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.
(2) Glass transition point Using a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.), 0.01 to 0.02 g of the sample was weighed into an aluminum pan, heated to 200 ° C., and the temperature decreased from that temperature. A sample cooled to 0 ° C. at a rate of 10 ° C./min is heated at a rate of temperature increase of 10 ° C./min. Is the temperature at the intersection with the tangent line.

3. Toner particle size analyzer: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 50 μm
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) is dissolved in the electrolytic solution to a concentration of 5% by weight to obtain a dispersion.
Dispersion conditions: 10 mg of a measurement sample is added to 5 ml of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 ml of an electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare a dispersion.
Measurement conditions: By adding the sample dispersion to 100 ml of the electrolyte solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured. Determine the volume median particle size (D ₅₀ ).

4). Melting point of mold release agent A sample was heated to 200 ° C. using a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.), and the sample was cooled to 0 ° C. at a temperature lowering rate of 10 ° C./min. The maximum peak temperature of heat of fusion is taken as the melting point.

5. Analysis by mass spectrometry gas chromatography A CI ion source and the following analysis column are attached to a mass spectrometry gas chromatograph (GC / MS), and the system is started up. In addition, CI reaction gas (methane) is flowed, and tuning is performed after 24 hours from the evacuation work of the MS section.

(1) GC
Gas chromatograph: Agilent HP6890N
Analysis column: Ultra 1 manufactured by HP (column length 50 m, inner diameter 0.
2mm, film thickness 0.33μm)
GC oven temperature rising condition: Initial temperature 100 ° C. (0 min)
First stage heating rate 1 ° C / min (up to 150 ° C)
Second stage heating rate 10 ° C / min (up to 300 ° C)
Final temperature 300 ℃ (10min)
Sample injection volume: 1 μL
Inlet condition: Injection mode Split method
Split ratio 50: 1
Inlet temperature 300 ° C
Carrier gas: gas helium
Flow rate 1ml / min (constant flow mode)

(2) Detector Mass spectrometer: 5973N MSD manufactured by Agilent
Ionization method: Chemical ionization method Reaction gas: Isobutane Temperature setting: Quadrupole 150 ° C
Ion source 250 ℃
Detection condition: Scan Scan range: m / z 75-300
Detector ON time: 5 min
Calibration (mass calibration and sensitivity adjustment)
: Reaction gas Methane
Calibrant PFDTD (Perfluoro-
5,8-dimethyl-3,6,9-trioxidedecane)
Tuning method Auto tuning

(3) Sample preparation Propylene tetramer was dissolved in isopropyl alcohol to 5%.
(Data processing method)
For the alkene component of each carbon number in the range of C9 to C14, a mass chromatogram based on the mass number corresponding to the molecular ion is extracted, and under the condition of S / N (signal / noise ratio)> 3, Perform integration according to the integration conditions. From the detection results shown in Tables 1 to 5, the ratio of the specific alkyl chain length component is calculated by the following formula.
Ratio of specific alkyl chain length component = [(total of integrated values of specific alkyl chain length) / (total of integrated values of C9 to C14)] × 100 (%)

（４）積分条件

(4) Integration conditions

C ₉ H ₁₈

C ₁₀ H ₂₀

C ₁₁ H ₂₂ , C ₁₂ H ₂₄ and C ₁₃ H ₂₆

C ₁₄ H ₂₈

  In the present invention, an alkylene compound having 9 to 14 carbon atoms refers to a peak corresponding to a molecular ion in gas chromatography mass spectrometry.

Production of alkylene compound A Using propylene tetramer (trade name: light tetramer) manufactured by Nippon Oil Corporation, fractionation was carried out under heating conditions of 183 to 208 ° C. to obtain alkylene compound A. The obtained alkylene compound A had 40 peaks in gas chromatography mass spectrometry.

Production of alkylene compound B An alkylene compound B was obtained in the same manner except that the fractionation conditions in the production example of the alkylene compound A were changed to 171 to 175 ° C. The resulting alkylene compound B had 25 peaks in gas chromatography mass spectrometry.

Production of alkenyl succinic anhydride A Into a 1 L autoclave manufactured by Nitto High Pressure Co., Ltd. 542.4 g of alkylene compound A, 157.2 g of maleic anhydride, 0.4 g of Chelex-O (manufactured by Sakai Chemical Industry Co., Ltd.), butyl hydroquinone , BHQ (abbreviated) 0.1 g was charged, and pressurized nitrogen substitution (0.2 MPaG) was repeated three times. After stirring was started at 60 ° C., the temperature was raised to 230 ° C. over 1 hour and the reaction was performed for 6 hours. The pressure when the reaction temperature was reached was 0.3 MPaG. After completion of the reaction, the reaction mixture was cooled to 80 ° C., returned to normal pressure (101.3 kPa), and transferred to a 1 L four-necked flask. The temperature was increased while stirring to 180 ° C., and the remaining alkylene compound was distilled off at 1.3 kPa over 1 hour. Subsequently, after cooling to room temperature (25 ° C.), the pressure was returned to normal pressure (101.3 kPa) to obtain the target product, alkenyl succinic anhydride A (406.1 g).

Production of alkenyl succinic anhydride B An alkenyl succinic anhydride B was obtained in the same manner as in the production of alkenyl succinic anhydride A except that alkylene compound B was used in place of alkylene compound A as a raw material.

Production Examples 1, 2, 4 to 6 and 8 (Production of resins A, B, D, E, F and H)
The raw material monomer of polyester excluding trimellitic anhydride shown in Table 6 and the esterification catalyst were put into a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring bar, a flow-down condenser and a nitrogen inlet tube, and nitrogen was added. The reaction was carried out at 230 ° C. and normal pressure (101.3 kPa) for 10 hours in a mantle heater in an atmosphere, and further reacted at 8 kPa for 1 hour. Then, it cooled to 160 degreeC and dripped the mixed solution of the raw material monomer of vinyl-type resin, a bireactive monomer, and a polymerization initiator over 1 hour. Then, after maintaining at 160 ° C. for 30 minutes, the temperature was raised to 210 ° C., and the reaction was performed at 8 kPa for 1 hour. Thereafter, the amount of trimellitic anhydride shown in Table 6 was added and allowed to react. The degree of polymerization is JIS standard “Ring and ball softening point test method” (Ring and ball automatic softening point tester 25D5-ASP-MG type, manufactured by Meitec Co., Ltd., measurement heating medium: glycerin, heating rate: 5 ° C./min, temperature. Total: Followed by the softening point according to JIS B7410 SP34 (for high softening point), SP33 (for low softening point), the reaction was terminated when the softening point reached a predetermined temperature, and resin A, B, D, E, F and H were obtained, respectively.

Production Example 3 (Production of Resin C)
The polyester raw material monomer and the esterification catalyst shown in Table 6 were placed in a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen inlet tube, and in a mantle heater in a nitrogen atmosphere. Then, the temperature was raised to 160 ° C., and a mixed solution of the raw material monomer of the vinyl resin, the bireactive monomer, and the polymerization initiator was added dropwise over 1 hour. Then, after maintaining at 160 ° C. for 30 minutes, the temperature was raised to 230 ° C., the reaction was carried out at normal pressure (101.3 kPa) for 10 hours, and further the reaction was carried out at 8 kPa to the desired softening point. The degree of polymerization is JIS standard “Ring and ball softening point test method” (Ring and ball automatic softening point tester 25D5-ASP-MG type, manufactured by Meitec Co., Ltd., measurement heating medium: glycerin, heating rate: 5 ° C./min, temperature. Total: Following the softening point according to JIS B7410 SP34 (for high softening point) and SP33 (for low softening point), the reaction was terminated when the softening point reached a predetermined temperature, and resin C was obtained.

Production Example 7 (Production of Resin G)
The raw material monomer of polyester excluding trimellitic anhydride shown in Table 6 and the esterification catalyst were put into a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring bar, a flow-down condenser and a nitrogen inlet tube, and nitrogen was added. The reaction was carried out at 230 ° C. and normal pressure (101.3 kPa) for 10 hours in a mantle heater in an atmosphere, and further reacted at 8 kPa for 1 hour. Thereafter, a release agent HNP-9 (manufactured by Nippon Seiki Co., Ltd., melting point: 70 ° C.) was added and cooled to 160 ° C., and a mixed solution of the vinyl resin raw material monomer, the bireactive monomer and the polymerization initiator was added for 1 hour. It was dripped over. Then, after maintaining at 160 ° C. for 30 minutes, the temperature was raised to 210 ° C., and the reaction was performed at 8 kPa for 1 hour. Thereafter, trimellitic anhydride shown in Table 6 was added and reacted. The degree of polymerization is JIS standard “Ring and ball softening point test method” (Ring and ball automatic softening point tester 25D5-ASP-MG type, manufactured by Meitec Co., Ltd., measurement heating medium: glycerin, heating rate: 5 ° C./min, temperature. Total: Following the softening point according to JIS B7410 SP34 (for high softening point) and SP33 (for low softening point), the reaction was terminated when the softening point reached a predetermined temperature, and resin G was obtained.

Production Example 9 (Production of Resin I)
The raw material monomer of polyester excluding trimellitic anhydride shown in Table 6 and the esterification catalyst were put into a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring bar, a flow-down condenser and a nitrogen inlet tube, and nitrogen was added. The reaction was carried out at 230 ° C. and normal pressure (101.3 kPa) for 10 hours in a mantle heater in an atmosphere, and further reacted at 8 kPa for 1 hour. Then, it cooled to 210 degreeC and added the trimellitic anhydride shown in Table 6 and made it react. The degree of polymerization is JIS standard “Ring and ball softening point test method” (Ring and ball automatic softening point tester 25D5-ASP-MG type, manufactured by Meitec Co., Ltd., measurement heating medium: glycerin, heating rate: 5 ° C./min, temperature. Total: Pursuant to the softening point according to JIS B7410 SP34 (for high softening point) and SP33 (for low softening point), the reaction was terminated when the softening point reached a predetermined temperature, and Resin I was obtained.

Example 1
Resin A 100 parts by weight, carbon black “MOGUL L” (Cabot Corporation) 4 parts by weight, negative charge control agent “Bontron S-34” (Orient Chemical Industries) 1 part by weight and polypropylene wax “NP-105” ”(Mitsui Chemicals Co., Ltd., melting point: 140 ° C.) 1 part by weight was sufficiently mixed with a Henschel mixer, and then using a co-rotating twin screw extruder (Ikegai Iron Works Co., Ltd. PCM-30), a roll rotation speed of 200 r / min, It was melt-kneaded at a heating temperature of 80 ° C. in the roll. The obtained melt-kneaded product is cooled and coarsely pulverized, then pulverized and classified by a jet mill (IDS-5 manufactured by Nippon Pneumatic Co., Ltd.), and powder having a volume-median particle size (D ₅₀ ) of 8.0 μm. A body toner was obtained.

Examples 2 to 7 and Comparative Examples 1 and 2
Each toner was obtained in the same manner as in Example 1 except that the resin A was replaced with the resin shown in Table 7.

The toner obtained in each of Examples 1 to 7 and Comparative Examples 1 and 2 was evaluated for low temperature fixability, offset resistance, developability under high temperature and high humidity, and durability by the following methods. The results are shown in Table 7.

[Evaluation of low-temperature fixability and offset resistance]
The toner is mounted on the printer “Page Presto N-4” (Casio Computer Co., Ltd., fixing: contact fixing method, developing method: non-magnetic one-component developing method, developing roll diameter: 2.3 cm), and the toner adhesion amount is set to 0.3. An unfixed image was obtained by adjusting to 8 mg / cm ² . A fixing machine (fixing speed: 350 mm / s) in which the fixing machine of the contact fixing type copying machine “AR-505” (manufactured by Sharp) is improved so that fixing can be performed outside the apparatus is obtained. Using the fixing roll, the unfixed image was fixed while increasing the temperature of the fixing roll from 100 ° C. to 240 ° C. by 10 ° C., and a fixing test was performed.
The image obtained at each fixing temperature was pasted with “UNICEF Cellophane” (Mitsubishi Pencil Co., Ltd., width 18 mm, JISZ-1522), passed through the fixing roll of the fixing machine set to 30 ° C., and then the tape was attached. The optical reflection density before and after peeling and tape peeling was measured using a reflection densitometer “RD-915” (manufactured by Macbeth). The fixing roller temperature at which the concentration ratio between the two before and after peeling (after peeling / before peeling) first exceeded 98% was defined as the lowest fixing temperature, and the low-temperature fixing property was evaluated according to the following evaluation criteria. At the same time, the occurrence of hot offset was visually observed, and the offset resistance was evaluated according to the following evaluation criteria.

Evaluation criteria (low temperature fixability)
A: Minimum fixing temperature is less than 160 ° C. ○: Minimum fixing temperature is 160 ° C. or more and less than 170 ° C. Δ: Minimum fixing temperature is 170 ° C. or more and less than 180 ° C. ×: Minimum fixing temperature is 180 ° C. or more.

(Offset resistance)
A: Hot offset does not occur even at 2100C.
○: Hot offset occurs at 180 ° C or higher and lower than 210 ° C.
×: Hot offset occurs at less than 180 ° C.

[Evaluation of developability in high temperature and high humidity (H / H) environment]
As a non-magnetic one-component developing device, toner is mounted on “Page Presto N-4” (manufactured by Casio Computer Co., Ltd.) equipped with a stainless steel developing roll, and 500 images are printed in an environment of 40 ° C. and 90% relative humidity. Got. The image density of the 50th and 500th images was measured using a transmission Macbeth densitometer “TR-927”, and the H / H environmental charge stability (the image density value of the 500th image / 50th image) The image density was evaluated according to the following criteria.
Evaluation criteria A : H / H environmental charging stability 0.90 or more O: H / H environmental charging stability 0.80 or more and less than 0.90 x: H / H environmental charging stability less than 0.80

[Durability evaluation]
Toner is mounted on a non-magnetic one-component development system "OKI Microline 18" (Oki Data Co., Ltd.), and a diagonal stripe pattern with a blackening rate of 5.5% under conditions of 32 ° C and 85%. Printing durability was performed. In the middle, a black solid image was printed every 500 sheets, and streaks on the image were confirmed. The number of printed sheets up to the time when the streak was visually observed on the image was defined as the number of printed sheets, and the durability was evaluated according to the following criteria.
Evaluation Criteria ◎: Printing durability is 5000 or more ○: Printing durability is 2000 or more to less than 5000 ×: Printing durability is less than 2000

  The toner of the present invention can obtain a stable image density even under high temperature and high humidity, and is excellent in low temperature fixability, hot offset resistance and durability. It can be suitably used as an electrophotographic toner used in a printing method or the like.

Claims (6)

  An electrophotographic toner containing a binder resin including a composite resin having a condensation polymerization resin unit and an addition polymerization resin unit, and obtained by a melt pulverization method, wherein the condensation polymerization resin unit has a branched chain. Derived from a carboxylic acid component containing at least two kinds of alkyl succinic acid having an alkyl group having 9 to 14 carbon atoms and / or at least two kinds of alkenyl succinic acid having a branched chain alkenyl group having 9 to 14 carbon atoms An electrophotographic toner having the following structural unit:   The carboxylic acid component is a structural isomer of an alkyl succinic acid having a branched C 9-14 alkyl group and / or an alkenyl succinic acid having a branched C 9-14 alkenyl group. The toner for electrophotography according to claim 1, comprising at least 20 types of body.   The alkyl succinic acid and / or alkenyl succinic acid is obtained from an alkylene compound and at least one selected from maleic acid and fumaric acid, and the alkylene compound has a carbon number in the range of 9 to 14 in gas chromatography mass spectrometry. The toner for electrophotography according to claim 1, which has at least 20 peaks corresponding to the alkylene compound therein.   The electrophotographic toner according to claim 1, wherein the total content of alkyl succinic acid and alkenyl succinic acid in the carboxylic acid component is 3 to 50 mol%.   A polycondensation resin unit polycondenses the raw material monomers for forming (a) a polyester obtained by polycondensing an alcohol component and a carboxylic acid component, and (b) an alcohol component, a carboxylic acid component, and an amide component. The polyester / polyamide obtained and (c) at least one selected from the group consisting of polyamides obtained by polycondensing raw material monomers for forming a carboxylic acid component and an amide component. The toner for electrophotography according to any one of the above.   A composite resin having a condensation polymerization resin unit and an addition polymerization resin unit is obtained by polymerizing a raw material monomer of a condensation polymerization resin, a raw material monomer of the addition polymerization resin, and a compound that can react with any of these. The toner for electrophotography according to any one of claims 1 to 5, which is a resin to be obtained.