JP2011186206A - Polyester resin composition for electrophotographic toner and electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for an electrophotographic toner excellent in low temperature fixability and hot offset resistance and capable of giving an image with favorable glossiness, and to provide an electrophotographic toner using the composition. <P>SOLUTION: A polyester resin composition for an electrophotographic toner is provided containing a polyester resin (A) which is obtained by making a polybasic acid (a1), a polyhydric alcohol (a2), an epoxy compound (a3) having one epoxy group, a polyepoxy compound (a4) having 2 to 4 epoxy groups, a polyepoxy compound (a5) having 5 or more epoxy groups, and an epoxy compound (a6) having a fatty acid ester structure but excluding the above compounds (a3) to (a5) react with one another, and the epoxy compound (a6) is used by 0.1 to 10 pts.mass with respect to 100 pts.mass of the sum of (a1) to (a6). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin composition for an electrophotographic toner that is excellent in low-temperature fixability and hot offset resistance, and provides an image with good gloss, and an electrophotographic toner using the composition.

  In recent years, in order to reduce the power consumption of laser printers and copiers, electrophotographic toners are required to have improved fixing performance (low temperature fixability) at lower temperatures. In order to improve the low-temperature fixability, a polyester-based resin is generally used as a binder resin in the toner, and the low-temperature fixability is improved by lowering the softening point of the resin. However, when the low temperature fixability of the electrophotographic toner is improved by lowering the softening point of the binder resin, the hot offset resistance is remarkably lowered.

  For this reason, a technique in which wax is included in the electrophotographic toner is generally used. However, in general, the compatibility between the wax and the polyester-based binder resin is extremely poor, and the wax can be contained in the binder resin, for example, only about 2 to 3% by weight. Even if the wax can be contained in the binder resin in an amount of 2 to 3% by weight or more, the wax dispersion in the toner becomes non-uniform and hot offset occurs. Thus, it has been difficult to obtain an electrophotographic toner excellent in low-temperature fixability and hot offset resistance. In addition, non-uniform wax dispersion in the toner results in an electrophotographic toner having poor fluidity. As a result, there is a problem that the glossiness of the obtained image is not sufficient.

  In order to obtain an electrophotographic toner that is excellent in low-temperature fixability and hot offset resistance, improvement in the dispersibility of wax in the electrophotographic toner has been attempted. Examples of the resin composition having improved wax dispersibility include, for example, a multi-branched polyester structure as a main skeleton, and an alkyl group having 20 to 80 carbon atoms or 20 to 80 carbon atoms at the molecular end thereof. A toner resin composition containing a highly branched polyester resin having an alkenyl group in a proportion of 25 to 95% by weight is disclosed (for example, see Patent Document 1).

  However, the electrophotographic toner obtained by using the resin composition containing the highly branched polyester resin is brittle and image degradation such as background occurs. In addition, the dispersion diameter of the wax is difficult to be reduced, so that a difference in the amount of wax in each toner particle occurs and charging abnormality occurs. If the toner charge amount is low, the image density decreases and the image sharpness deteriorates, and the amount of toner consumption increases, which is economically inefficient.

  Further, it is disclosed that a vinyl polymer composition containing a fatty acid ester having a branched structure and a resin composition containing a polyester resin can provide an electrophotographic toner excellent in low-temperature fixability and hot offset resistance (for example, , See Patent Document 2). However, although the vinyl polymer composition in the resin composition has good dispersibility with the wax, the compatibility with the polyester resin is not sufficient, and the amount of the vinyl polymer composition in each toner particle, the amount of the polyester resin, Further, a difference occurs in the amount of wax and the like, and it is difficult to obtain an electrophotographic toner satisfying the low-temperature fixability and hot offset resistance at levels required by the market.

International Publication No. 2009/093592 Pamphlet JP 2006-301177 A

  An object of the present invention is to provide a resin composition capable of obtaining an electrophotographic toner that is excellent in low-temperature fixability and hot offset resistance, has an excellent glossiness, has a high charge amount, and has excellent charge stability. And providing an electrophotographic toner using the composition.

  As a result of intensive studies, the present inventors have found that a polyester resin having a specific amount of fatty acid ester structure is useful as a binder resin by itself, the polyester resin is excellent in wax dispersibility, and wax is electrophotographic toner. By adding about 5% by mass, it is possible to obtain an electrophotographic toner with low temperature fixing property, hot offset resistance, charging stability, excellent gloss, and high charge amount, and if necessary, a larger amount The present inventors have found that wax can be dispersed in the polyester resin and have completed the present invention.

  That is, the present invention includes polybasic acid (a1), polyhydric alcohol (a2), epoxy compound (a3) having one epoxy group, polyepoxy compound (a4) having 2 to 4 epoxy groups, and 5 It is a polyester resin obtained by reacting the above epoxy group-containing polyepoxy compound (a5) and an epoxy compound (a6) other than the above (a3) to (a5) having a fatty acid ester structure, and an epoxy compound (a6) A polyester resin composition for an electrophotographic toner, comprising a polyester resin (A) obtained by using 0.1 to 10 parts by mass of 100 to 100 parts by mass of (a1) to (a6) To do.

  The present invention also provides an electrophotographic toner comprising the resin composition for an electrophotographic toner.

  According to the present invention, it is possible to obtain an electrophotographic toner that is excellent in low-temperature fixability and hot offset resistance and that can provide an image with good gloss. The electrophotographic toner has a high charge amount and excellent charge stability. The resin composition for an electrophotographic toner of the present invention also has good pulverization properties, and an electrophotographic toner can be efficiently obtained by using the composition.

  The polyester resin (A) used in the present invention includes a polybasic acid (a1), a polyhydric alcohol (a2), an epoxy compound (a3) having one epoxy group, and a polyepoxy compound (a4) having 2 to 4 epoxy groups. ) A polyester resin obtained by reacting a polyepoxy compound (a5) having 5 or more epoxy groups and an epoxy compound (a6) other than the above (a3) to (a5) having a fatty acid ester structure. The compound (a6) is obtained using 0.1 to 10 parts by mass with respect to 100 parts by mass in total of (a1) to (a6). As said polybasic acid (a1), the acid anhydride of this polybasic acid and these lower alkyl esters can also be used as a polybasic acid, for example. Examples of the polybasic acid (a1) include saturated polybasic acids and unsaturated polybasic acids.

  Examples of the saturated polybasic acid, saturated polybasic acid and lower alkyl ester of saturated polybasic acid include, for example, adipic acid, sebacic acid, orthophthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, succinic anhydride, Dibasic acids such as alkyl succinic acid having 8 to 18 carbon atoms, alkyl succinic anhydride, alkenyl succinic acid, alkenyl succinic anhydride; trimellitic acid, trimellitic anhydride, cyanuric acid, pyromellitic acid, pyromellitic anhydride And polybasic acids. Examples of the alkyl mentioned here include alkyl esters having 8 to 18 carbon atoms.

  Examples of the unsaturated polybasic acid include maleic acid, maleic anhydride, and fumaric acid.

  The polybasic acid (a1) may be used alone or in combination of two or more. Moreover, you may use monobasic acids, such as benzoic acid and p-tert- butylbenzoic acid, as needed.

  Among the polybasic acids (a1) used in the present invention, a toner excellent in offset resistance and low-temperature fixability can be obtained, so that one kind selected from the group consisting of divalent basic acids, their anhydrides and their lower alkyl esters Polybasic acids containing the above compounds are preferred, and isophthalic acid and terephthalic acid are more preferred among one or more compounds selected from the group consisting of the divalent basic acids, their anhydrides and their lower alkyl esters.

  Furthermore, as the above-mentioned polybasic acid (a1), those in which part or all of the carboxy group is alkenyl ester or allyl ester can also be used.

  Examples of the polyhydric alcohol (a2) used in the present invention include divalent alcohols and trivalent or higher alcohols.

  Examples of the divalent alcohols include aliphatic diols such as linear aliphatic diols and cycloaliphatic diols, and aromatic diols. Examples of the linear aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, polyethylene glycol, polypropylene glycol, and ethylene oxide-propylene. Examples thereof include an oxide random copolymer diol, an ethylene oxide-propylene oxide block copolymer diol, an ethylene oxide-tetrahydrofuran copolymer diol, and a polycaprolactone diol.

  Examples of the cycloaliphatic diol include 1,4-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, and the like.

  Examples of the aromatic diols include diols having a bisphenol skeleton. Examples of the diol having a bisphenol skeleton include bisphenols such as bisphenol A and bisphenol F; bisphenols such as an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A. A-alkylene oxide adduct and the like.

  Examples of the trivalent or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, 2-methylpropanetriol, and the like.

  The polyhydric alcohol (a2) used in the present invention is preferably a polyhydric alcohol having an alkyl group having 2 to 12 carbon atoms in the side chain because an electrophotographic toner having good grindability can be obtained. Examples of such polyhydric alcohols include 2-ethyl 4-butylhexanediol, butylethylpropanediol, 2,4-diethyl 3,5-pentadiol, and the like.

  Further, the polyhydric alcohol (a2) used in the present invention is preferably a diol having a bisphenol skeleton because an electrophotographic toner having good charge stability can be obtained. Among diols having a bisphenol skeleton, an alkylene oxide adduct of bisphenols is more preferable.

  Furthermore, the polyhydric alcohol used in the present invention is preferably a mixture of a diol having a bisphenol skeleton and an aliphatic diol because an electrophotographic toner resin composition having good grindability can be obtained. Among the aliphatic diols, one or more alcohols selected from the group consisting of ethylene glycol, propylene glycol and neopentyl glycol are preferable.

  A polyhydric alcohol (a2) may be used independently and may use 2 or more types together. Moreover, you may use monoalcohols, such as a stearyl alcohol, as needed within the range which does not impair the effect of this invention.

  Examples of the epoxy compound (a3) used in the present invention include phenyl glycidyl ether, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, glycidyl ether of alkylphenol alkylene oxide adduct, α-olefin oxide, monoepoxy fatty acid alkyl ester. Etc. are preferable.

  Examples of the alkylphenyl glycidyl ether include cresyl glycidyl ether, butyl glycidyl ether, and nonyl glycidyl ether. Examples of the alkyl glycidyl ether include butyl glycidyl ether and 2-ethylhexyl glycidyl ether.

  Examples of the alkyl glycidyl ester include the following general formula (1):

  (Wherein R is an alkyl group having 1 to 25 carbon atoms, preferably an alkyl group having 10 to 15 carbon atoms), and the like.

  Furthermore, examples of the glycidyl ether of the alkylphenol alkylene oxide adduct include a glycidyl ether of a compound obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to a lower alkylphenol such as butylphenol, and specific examples include ethylene glycol monophenyl. Glycidyl ether of ether, glycidyl ether of polyethylene glycol monophenyl ether, glycidyl ether of propylene glycol monophenyl ether, glycidyl ether of polypropylene glycol monophenyl ether, glycidyl ether of propylene glycol mono (pt-butyl) phenyl ether, ethylene glycol And glycidyl ether of monononylphenyl ether.

  Examples of the α-olefin oxide include compounds obtained by oxidizing olefins such as alpha olefin oxide-168 [Adeka Gas Chemical Co., Ltd. product] and alpha olefin oxide-124 [Adeka Argus Chemical Co., Ltd. product]. Can be mentioned.

  The monoepoxy fatty acid alkyl ester is, for example, a compound obtained by epoxidizing an unsaturated group of an alcohol ester of an unsaturated fatty acid, such as an epoxidized oleic acid butyl ester, the following structural formula (2)

And epoxidized oleic acid octyl ester and the like. These monoepoxy compounds may be used alone or in combination of two or more.

  Among the epoxy compounds (a3) used in the present invention, the monoepoxy compound represented by the general formula (1) is more preferable because the obtained polyester resin (A) has good affinity with wax.

  Examples of the epoxy compound (a4) having 2 to 4 epoxy groups used in the present invention include bisphenol type epoxy resins such as bisphenol A type epoxy resins, novolak type epoxy resins, naphthalene type epoxy resins, and dicyclopentadiene. Type epoxy resin, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, hydroquinone diglycidyl ether, and the like.

  Among the epoxy compounds (a4) used in the present invention, a divalent epoxy compound is preferable because an electrophotographic toner having good charging stability is obtained, and among the divalent epoxy compounds, plasticizer resistance is good. Bisphenol type epoxy resin is preferable, and bisphenol A type epoxy resin is more preferable.

  The epoxy compound (a4) having 2 to 4 epoxy groups may be used in combination of two or more.

  Among the polyester resins (A) used in the present invention, the (a4) having 2 to 4 epoxy groups is converted into a polyvalent epoxy compound (a5), a polyhydric alcohol (a2), and a polybasic acid (a1). A polyester resin composition obtained by using 0.1 to 30 parts by weight of the polyester resin with respect to 100 parts by weight in total provides a polyester resin composition for a toner having good pulverizability, and an electrophotographic toner having good charging stability and gloss. Therefore, a polyester resin obtained by using 0.5 to 10 parts by weight is more preferable.

  Examples of the polyepoxy compound (a5) having 5 or more epoxy groups used in the present invention include novolac type epoxy resins, dicyclopentadiene type epoxy resins, bisphenol A type novolac type epoxy resins, and vinyl compounds having an epoxy group. Examples thereof include a polymer or copolymer, an epoxidized resorcinol-acetone condensate, and a partially epoxidized polybutadiene.

  Among the polyepoxy compounds (a5) used in the present invention, a novolac type epoxy resin is preferable because a resin composition for an electrophotographic toner having good grindability can be obtained. Among the novolac type epoxy resins, for example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol A alkylene oxide adduct type novolac type epoxy resin, bisphenol F alkylene oxide adduct type One or more novolac epoxy resins selected from the group consisting of novolac epoxy resins, naphthalene type novolac epoxy resins and dicyclopentadiene type novolac epoxy resins are preferred. Further, a cresol novolac type epoxy resin, a bisphenol A novolak type epoxy resin, and a phenol novolak type epoxy resin are more desirable.

  Moreover, as a polyepoxy compound (a5) used by this invention, the compound which has 5-15 epoxy groups is preferable.

  Furthermore, among the polyepoxy compounds (a5), in order to obtain a polyester resin for an electrophotographic toner excellent in charging characteristics, low-temperature fixability and hot offset resistance, a weight average molecular weight (Mw) and a number average molecular weight (Mn) described later are obtained. Since the ratio [(Mw) / (Mn)] is easily in the range of 5 to 70, a cresol novolac epoxy resin is preferable.

  The polyepoxy compound (a5) may be used in combination of two or more.

  The compound (a6) used in the present invention is an epoxy compound other than the above (a3) to (a5) and has a fatty acid ester structure. Examples of such compounds include those obtained by epoxidizing a reaction product (esterified product) of an unsaturated fatty acid having a carbon-carbon double bond and an alcohol, and an unsaturated fatty acid having a carbon-carbon double bond. Preferable examples include those obtained by reacting an epoxidized reaction product with alcohol and esterified, those obtained by epoxidizing vegetable oil, those obtained by epoxidizing a reaction product (esterified product) of vegetable oil and alcohol, etc. Can do.

  Examples of the epoxidizing agent include hydrogen peroxide, peracetic acid, perbenzoic acid, and the like.

  Examples of the unsaturated fatty acid include monounsaturated fatty acids such as crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, and nervonic acid; linoleic acid, eicosadiene Diunsaturated fatty acids such as acid, docosadienoic acid; triunsaturated fatty acids such as linolenic acid, pinolenic acid, eleostearic acid, mead acid, dihomo-γ-linolenic acid, eicosatrienoic acid; stearidonic acid, arachidonic acid, eico Tetraunsaturated fatty acids such as satetraenoic acid and adrenic acid: pentaunsaturated fatty acids such as boseopentaenoic acid, eicosapentaenoic acid, ozbond acid, sardine acid, tetracosapentaenoic acid; hexaunsaturated acids such as docosahexaenoic acid and nisic acid Examples include fatty acids. Among unsaturated fatty acids, unsaturated fatty acids having 2 to 30 carbon atoms are preferable because they have good WAX dispersibility and do not deteriorate the performance of the resin itself, and unsaturated fatty acids having 2 to 25 carbon atoms are more preferable.

  Examples of the alcohol include methyl alcohol, ethyl alcohol, butyl alcohol, and isopropanol.

  Among the compounds obtained by epoxidizing the reaction product (esterified product) of the unsaturated fatty acid and alcohol, epoxidized oleic butyl ester is more preferable.

  Examples of the vegetable oil include coconut oil, corn oil, cottonseed oil, olive oil, palm oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, nut oil, almond oil, cashew oil. , Hazelnut oil, macadamia nut oil, mongongo oil, pecan oil, pine nut oil, pistachio oil, walnut oil, gourd seed oil, buffalo pumpkin oil, pumpkin seed oil, watermelon seed oil, cassis oil, borage seed oil, evening primrose oil, Apricot oil, apple oil, argan oil, artichoke oil, avocado oil, babas oil, moringa oil, cape chestnut oil and the like.

  A compound obtained by allowing an epoxidizing agent such as hydrogen peroxide, peracetic acid or perbenzoic acid to act on an ester of an unsaturated fatty acid and an alcohol as described above and epoxidizing a carbon-carbon double bond is a plasticity of the resin. Commercially available agents and stabilizers can be used.

  Among those obtained by epoxidizing vegetable oil, epoxidized soybean oil and epoxidized linseed oil are more preferable because a resin composition having good compatibility with WAX can be obtained.

  The polyester resin (A) used in the present invention includes a polybasic acid (a1), a polyhydric alcohol (a2), an epoxy compound (a3), an epoxy compound (a4), an epoxy compound (a5), and an epoxy compound (a6). 20 to 70 parts by mass, 30 to 70 parts by mass, 0.1 to 5 parts by mass, 0.1 to 10 parts by mass, 0.1 to 10 parts by mass with respect to 100 parts by mass in total of (a1) to (a6). The polyester resin obtained by using 10 parts by mass and 0.1 to 10 parts by mass is preferable because it provides an electrophotographic polyester resin having excellent wax dispersibility and excellent low-temperature fixability and hot offset resistance. A polyester resin obtained by using 65 parts by mass, 30-50 parts by mass, 0.1-2 parts by mass, 0.1-5 parts by mass, 0.5-5 parts by mass and 0.5-5 parts by mass is more preferable. Better Yes.

  In this invention, when obtaining a polyester resin (A), compounds other than said (a1)-(a6) can be used as a raw material as needed. As such a compound, for example, it has a functional group capable of reacting with the functional group of any one of the compounds (a1) to (a6), and one carbon atom has 2 to 22 carbon atoms. Preferred examples include compounds in which two or more alkyl groups are directly bonded. Examples of such a compound (a6) include a compound having a carboxyl group and two or more alkyl groups directly bonded to one carbon atom, a hydroxyl group, and one carbon. A compound having two or more alkyl groups directly bonded to an atom, an epoxy group, and a compound having two or more alkyl groups directly bonded to one carbon atom, having an amine group A compound in which two or more alkyl groups are directly bonded to one carbon atom, a compound having an isocyanate group and two or more alkyl groups directly bonded to one carbon atom A compound having a vinyl group and two or more alkyl groups directly bonded to one carbon atom, a compound having a carboxyl group and a hydroxyl group, and two or more alkyl groups on one carbon atom The group is directly Combined compounds, and the like are.

  Examples of the compound having the carboxyl group and having two or more alkyl groups directly bonded to one carbon atom include monocarboxylic acids such as 2-ethylhexanoic acid and 2-ethylbutyric acid; 2 -Butyl-2-ethylpropanedicarboxylic acid, 2,2-ethylpropanedicarboxylic acid, 2-butyl-2-ethylpentanedicarboxylic acid, 2,2-dioctadecylpropanedicarboxylic acid, 2-ethyl-2-octadecylpropanedicarboxylic acid And dicarboxylic acid.

  Examples of the compound having the hydroxyl group and two or more alkyl groups directly bonded to one carbon atom include 2-ethylhexanol and monoalcohol of ethylene glycol mono-2-ethylhexyl ether; Aliphatic diols such as 2,2-ethylpropanediol, 2-butyl-2-ethylpropanediol, 2-butyl-2-ethylpentanediol, 2,2-dioctadecylpropanediol, and 2-ethyl-2-octadecylpropanediol And aromatic diols such as 4,4 ′-(2-ethylhexylidene) diphenol.

  Examples of the compound having the epoxy group and two or more alkyl groups directly bonded to one carbon atom include 2-ethylhexyl = 3,4-epoxycyclohexanecarboxylate, 2- (2 -Ethoxyhexyl) epoxide, monoepoxy compounds; 2-butyl-2-ethylpropane diepoxide, 2,2-ethylpropane diepoxide, 2-butyl-2-ethylpentane diepoxide, 2,2-dioctadecylpropanedioxide Examples include epoxides and diepoxides such as 2-ethyl-2-octadecylpropane diepoxide.

  Examples of the compound having the amine group and two or more alkyl groups directly bonded to one carbon atom include 2-ethylhexylamine, di-2-ethylhexylamine, 3- (2 -Monoamine compounds such as -ethylhexyloxy) -propylamine; 2-butyl-2-ethylpropanediamine, 2,2-ethylpropanediamine, 2-butyl-2-ethylpentanediamine, 2,2-dioctadecylpropanediamine, 2 Examples include diamine compounds such as -ethyl-2-octadecylpropanediamine.

  Examples of the compound having the isocyanate group and two or more alkyl groups directly bonded to one carbon atom include monoisocyanate compounds such as 2-ethylhexyl isocyanate; 2-butyl-2 -Diisocyanate compounds such as -ethylpropane diisocyanate, 2,2-ethylpropane diisocyanate, 2-butyl-2-ethylpentane diisocyanate, 2,2-dioctadecylpropane diisocyanate, and 2-ethyl-2-octadecylpropane diisocyanate.

  Examples of the compound having the vinyl group and two or more alkyl groups directly bonded to one carbon atom include 2-ethylhexyl acrylate, 2-butylhexyl acrylate, 2-acrylate acrylate, and the like. Butyldecyl, 3-ethyl-3-propylhexyl acrylate, 2-ethylhexyl methacrylate, 2-butylhexyl methacrylate, 2-butyldecyl methacrylate, 3-ethyl-3-propylhexyl methacrylate, oleic acid-2-octyldodecyl, 2 -Monovinyl compounds such as ethylhexyl vinyl ether; 2-ethyl-2-butyl-1,3-propanezyl diacrylate, 2-ethyl-2-ethyl-1,3-propanezyl diacrylate, 2-ethyl-2-butyl-1,6-hexanezyl Diacrylate, 3-ethyl-3-bu Divinyl compounds such as Lou 1,6 Jill diacrylate and the like.

  Examples of the compound having a carboxyl group and a hydroxyl group, and two or more alkyl groups directly bonded to one carbon atom include 2-ethyl-2-hydroxymethylbutanoic acid, 2-ethyl-2 -Hydroxymethylhexanoic acid, 2-ethyl-2-hydroxymethyldecanoic acid, 14-ethyl-12-hydroxystearic acid and the like.

  The alkyl group in the compound is preferably an alkyl group having 2 to 8 carbon atoms because a polyester resin with improved wax dispersibility is obtained. The compound is preferably an aliphatic diol because a polyester resin having good compatibility with the wax can be obtained. Among the compounds, 2-butyl-2-ethylpropanediol is particularly preferable.

  The polyester resin (A) used in the present invention is optionally produced by a known polycondensation reaction method. For example, in the presence of an esterification catalyst (tin compound, titanium compound, zirconium compound, etc.) or in the presence of a transesterification catalyst (lead compound, tin compound, zinc compound, titanium compound, etc.), lower alkyl such as dicarboxylic acid methyl ester The transesterification reaction using an ester, normal pressure dehydration reaction, reduced pressure and vacuum dehydration reaction, solution polycondensation method, solid phase polycondensation reaction and any other production method may be used. The polyesterification reaction at this time can be traced by measuring the acid value, hydroxyl value, viscosity or softening point.

  As an apparatus used at this time, for example, a batch-type production apparatus such as a reaction vessel equipped with a nitrogen inlet, a thermometer, a stirring device, a rectifying tower, etc. can be preferably used, or a deaeration port is provided. Extruders, continuous reactors, kneaders and the like can also be used. In the dehydration condensation, the esterification reaction can be promoted by reducing the pressure of the reaction system as necessary.

  When the polyester resin (A) used in the present invention is produced, polycondensation is performed in the presence of a titanium compound in which a phosphorus compound is covalently bonded and / or a titanium compound in which a phosphorus compound is coordinated as a titanium compound. ) Is preferable because it becomes a transparent polyester resin with suppressed coloring.

  The titanium compound is a titanium compound in which a phosphorus compound is covalently bonded and a titanium compound in which a phosphorus compound is coordinated. Examples of the titanium compound to which the phosphorus compound is covalently bonded include a titanium compound having a structure in which the phosphorus compound is bonded to the titanium compound through an ether bond of the phosphorus compound. Examples of the titanium compound in which the phosphorus compound is coordinate-bonded include a titanium compound having a structure bonded to the titanium compound via an unshared electron pair of the phosphorus compound. Examples of such compounds include phosphate titanium compounds, phosphite titanium compounds, phosphonic acid titanium compounds, phosphonic acid titanium compounds, phosphinic acid titanium compounds, phosphinic acid titanium compounds, Examples include phosphine oxide acid titanium compounds and phosphine titanium compounds.

  Examples of the phosphate titanium compound include a monophosphate titanium compound, a bisphosphate titanium compound, and a trisphosphate titanium compound. Examples of the monophosphate titanium compound include triisopropoxy titanium / dioctyl phosphate, triisopropoxy titanium / dioctyl pyrophosphate, tributoxy titanium / dioctyl phosphate, tributoxy titanium / dioctyl pyrophosphate, tri-2-ethylhexyloxytitanium / Examples include dioctyl phosphate, tri-2-ethylhexyloxytitanium / dioctylpyrophosphate, tristearoxytitanium / dioctylphosphate, tristearoxytitanium / dioctylpyrophosphate, and the like.

  Examples of the bisphosphate titanium compound include diisopropoxy titanium / bisdioctyl phosphate, diisopropoxy titanium / bisdioctyl pyrophosphate, dibutoxy titanium / bisdioctyl phosphate, dibutoxy titanium / bisdioctyl pyrophosphate, Ethylhexyloxytitanium / bisdioctylphosphate, G-2-ethylhexyloxytitanium / bisdioctylpyrophosphate, distearoxytitanium / bisdioctylphosphate, distearoxytitanium / bisdioctylpyrophosphate, bisdioctylphosphate ethylene glycolatotitanium, bisdioctylpyro Phosphate / ethylene glycolato titanium, titanium / bisdioctyl pyrophosphate oxyacetate, titanium Um bis dioctylphosphate oxyacetate like.

  Examples of the trisphosphate titanium compound include isopropoxy titanium / trisoctyl phosphate, isopropoxy titanium / tris dioctyl pyrophosphate, butoxy titanium / tris dioctyl phosphate, butoxy titanium / tris dioctyl pyrophosphate, 2-ethylhexyloxy titanium / tris dioctyl phosphate. 2-ethylhexyloxytitanium / trisdioctylpyrophosphate, stearoxytitanium / trisdioctylphosphate, stearoxytitanium / trisdioctylpyrophosphate, and the like.

  Examples of the phosphite-based titanium compounds include monophosphite-based titanium compounds, bisphosphite-based titanium compounds, and trisphosphite-based titanium compounds. Examples of the monophosphite-based titanium compound include triisopropoxy titanium / dioctyl phosphite, tributoxy titanium / dioctyl phosphite, tri-2-ethylhexyloxy titanium / dioctyl phosphite, tristeoxy titanium / dioctyl phosphite, and the like. It is done.

  Examples of the bisphosphite-based titanium compound include diisopropoxy titanium / bisdioctyl phosphite, dibutoxy titanium / bisdioctyl phosphite, di-2-ethylhexyloxytitanium / bisdioctyl phosphite, distearoxy titanium / bisdioctyl. Examples thereof include phosphite, bisdioctyl phosphite ethylene glycolate titanium, titanium / bisdioctyl phosphite oxyacetate, and tetraisopropoxytitanium / bisdioctyl phosphite.

  Examples of the trisphosphite-based titanium compound include isopropoxy titanium / trisoctyl phosphite, butoxy titanium / tris dioctyl phosphite, 2-ethylhexyloxy titanium / tris dioctyl phosphite, stearoxy titanium / tris dioctyl phosphite, Examples include propoxy titanium and trisdioctyl phosphite.

  Examples of the phosphonic acid-based titanium compound include isopropoxytitanium / trisdioctylphosphonic acid, bisdioctylphosphonic acid ethylene glycolatotitanium, isopropoxytitanium / bisdioctylphosphonic acid, and the like.

  Examples of the phosphonous titanium compound include isopropoxytitanium / trisdioctylphosphonous acid, bisdioctylphosphonic acid ethylene glycolatotitanium, isopropoxytitanium / bisdioctylphosphonous acid, and the like.

  Examples of the phosphinic acid-based titanium compound include isopropoxytitanium / trisoctylphosphinic acid, bisoctylphosphinic acid ethylene glycolatotitanium, isopropoxytitanium / bisoctylphosphinic acid, and the like.

  Examples of the phosphinic acid titanium compound include isopropoxy titanium / trisoctyl phosphinic acid, bisoctyl phosphinic acid ethylene glycolato titanium, isopropoxy titanium / bisoctyl phosphinic acid, and the like.

  Examples of the phosphine oxide acid-based titanium compound include isopropoxy titanium / trisdioctyl phosphine oxide, isopropoxy titanium / trisdioctyl phosphine oxide, bisdioctyl phosphine oxide ethylene glycolato titanium, bisdioctyl phosphine oxide ethylene glycolato titanium, isopropoxy. Examples include titanium / bisdioctylphosphine oxide, isopropoxytitanium / bisdioctylphosphine oxide, and the like.

  Examples of the phosphinic acid titanium compound include isopropoxy titanium / trisdioctyl phosphine, isopropoxy titanium / tris dioctyl phosphine, bisdioctyl phosphine ethylene glycolato titanium, bis dioctyl phosphine ethylene glycolato titanium, isopropoxy titanium / bis dioctyl. Examples include phosphine, isopropoxytitanium / bisdioctylphosphine, and the like.

  As the titanium compound, a polyester resin obtained by using a phosphate-based titanium compound and a phosphite-based titanium compound because an electrophotographic toner having excellent glossiness can be obtained by suppressing coloration more and becoming a highly transparent polyester resin. Resins are preferred, polyester resins obtained using bisphosphate titanium compounds and bisphosphite titanium compounds are more preferred, and polyester resins obtained using pyrophosphate titanium compounds are even more preferred.

  Further, as the polyester resin (A) used in the present invention, a polyester resin obtained by using a titanium compound having an alkylene oxide chain as a titanium compound covalently bonded to a phosphorus compound and / or a titanium compound coordinated to a phosphorus compound. However, it is preferable because it becomes an electrophotographic toner from which a printed matter with good gloss can be obtained. Among the alkylene oxide chains, an alkylene oxide chain having 2 to 22 carbon atoms is preferable.

  Among these titanium compounds, titanium / bisdioctyl pyrophosphate oxyacetate and diisopropoxy titanium / bisdioctyl pyrophosphate are more preferable.

  The amount of the titanium compound covalently bonded to the phosphorus compound and / or the titanium compound coordinated to the phosphorus compound is such that the weight of the titanium atom in the titanium compound is relative to the total weight of the raw materials constituting the polyester resin (A). 0.1 to 100 ppm is preferable because the reaction efficiency is good and the polyester resin is less colored, more preferably 1 to 50 ppm, and more preferably 5 to 30 ppm. More preferably, it is used.

  The polyester resin (A) used in the present invention is a polyester having a glass transition temperature (Tg) of 45 to 90 ° C. because an electrophotographic toner having better low-temperature fixability and good gloss on the printed surface can be obtained. A resin is preferable, and a polyester resin at 55 to 85 ° C. is more preferable. In addition, a polyester resin having a softening point of 90 to 210 ° C. is preferable, and a polyester resin having a softening point of 100 to 180 ° C. is more preferable because better hot offset properties can be obtained.

  Accordingly, a polyester resin having a glass transition temperature (Tg) of 50 to 90 ° C. and a softening point of 90 to 210 ° C. is preferable, and a glass transition temperature (Tg) of 55 to 85 ° C. and softening. A polyester resin having a point of 100 to 180 ° C. is more preferable.

The glass transition temperature is a value measured under the following conditions.
Measuring device: Seiko Electronics Co., Ltd. DSC220C
Measurement conditions: 10 ° C./min, Sample: About 10 mg of sample is put in an aluminum container and the lid is closed.
Measuring method: DSC (Suggested scanning calorimetry) method

The softening point was measured under the following conditions.
Measuring equipment: CFT-500D manufactured by Shimadzu Corporation
Measurement conditions: temperature rising rate 6 ° C./min, nozzle 1.0 mmΦ × 1 mm, load 10 kgf, sample amount 1.5 g, measurement start temperature 50 ° C.
Here, the softening point is the temperature (T1) when the plunger (piston) comes to an intermediate point in the process from the start of the outflow to the end of the outflow in the Koka-type flow tester [CFT-500D manufactured by Shimadzu Corporation]. / 2).

  The polyester resin (A) used in the present invention is preferably a polyester having a weight average molecular weight (Mw) of 8,000 to 700,000 because a toner having excellent low-temperature fixability and hot offset resistance is obtained. 10,000 to 500 1,000 polyesters are more preferred. Further, the polyester resin used in the present invention preferably has a number average molecular weight (Mn) of 1,500 to 8,000 because it maintains a good glass transition temperature and, as a result, a good storage-stable toner is obtained. 2,000 to 7,500 polyesters are more preferred.

  Furthermore, the polyester resin (A) used in the present invention has a ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC). The polyester resin is preferably 3 to 100, and more preferably 3 to 70 in terms of (Mw / Mn).

  The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyester resin in the present invention are values measured by the GPC method under the conditions shown below for components dissolved in tetrahydrofuran.

Molecular weight measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Guard column H _XL- H manufactured by Tosoh Corporation
+ Tosoh Corporation TSKgel G5000H _XL
+ Tosoh Corporation TSKgel G4000H _XL
+ Tosoh Corporation TSKgel G3000H _XL
+ Tosoh Corporation TSKgel G2000H _XL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate 1.0 ml / min Standard; polystyrene sample; 0.4% by weight tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

  The softening point of the polyester resin of the present invention is preferably 90 ° C. to 210 ° C., more preferably 100 ° C. to 180 ° C., because it is excellent in low-temperature fixing, offset resistance and charging stability.

  The resin composition for an electrophotographic toner of the present invention may contain the polyester resin (A), but a release agent, a colorant, a charge control agent and the like can be added as necessary.

  Examples of the mold release agent include various waxes. For example, natural waxes such as montan wax, carnauba wax, candelilla wax and rice wax, synthetic waxes such as polypropylene wax and polyethylene wax can be used.

  In particular, in heat roller fixing applications, a release agent can be used for the purpose of preventing troubles due to toner contamination on the heat roller (offset). Examples of such a release agent include various waxes. For example, natural waxes such as montan wax, carnauba wax, candelilla wax and rice wax; synthetic waxes such as polypropylene wax and polyethylene wax can be used. Suitable waxes include, for example, carnauba wax.

  The weight ratio of the release agent in the electrophotographic toner resin composition of the present invention is not particularly limited, but is usually 0.3 to 15 parts by weight, preferably 1 per 100 parts by weight of the toner resin composition. ~ 5 parts by weight.

  Examples of the colorant include various non-magnetic organic pigments and inorganic pigments, such as carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, phthalocyanine blue, lamp black, rose bengara, quinacridone red, A watching red etc. can be mentioned, It can use by 1 type, or 2 or more types of combination.

  The weight ratio with the colorant in the electrophotographic toner resin composition of the present invention is not particularly limited, but usually 1 to 60 parts by weight, preferably 3 to 30 parts by weight of the colorant per 100 parts by weight of the resin composition for toner. Part.

  Examples of the charge control agent include known conventional charges such as nigrosine dyes, quaternary ammonium salts, trimethylethane dyes, copper phthalocyanine, perylene, quinacridone, azo pigments, heavy metal-containing acid dyes such as metal complex azo dyes. A control agent can be mentioned and it can use 1 type or in combination of 2 or more types.

  The weight ratio with the charge control agent in the resin composition for an electrophotographic toner of the present invention is not particularly limited, but is preferably 0.5 to 3 per 100 parts by weight of the toner resin composition. Part by weight is desirable.

  Further, the resin composition for an electrophotographic toner of the present invention is a conventionally known resin such as a styrene resin, a styrene-acrylic copolymer resin, an epoxy resin, or a polyester other than those described above, as long as the effects of the present invention are not lost. An appropriate amount of resin, silicone resin, polyurethane resin, or the like can be blended. The compounding quantity is about 1-30 weight part normally with respect to 100 weight part of this polyester resin.

  The electrophotographic toner obtained using the resin composition for an electrophotographic toner of the present invention can be obtained by any known and commonly used production method. For example, it can be obtained by melt-kneading a binder resin and a colorant at a temperature equal to or higher than the melting point of the binder resin, pulverizing, and classifying. Of course, you may manufacture by a method other than this.

  In obtaining the electrophotographic toner of the present invention, various auxiliary agents such as a fluidity improver can be further added in any step of the production. It is effective to attach the fluidity improver to the surface of the electrophotographic toner.

  The electrophotographic toner obtained by using the electrophotographic toner resin composition of the present invention can be obtained by any known and commonly used production method. For example, it can be obtained by melt-kneading the polyester resin and the colorant at a temperature equal to or higher than the melting point of the polyester resin, pulverizing and classifying. Of course, you may manufacture by a method other than this.

  The toner powder obtained in the present invention can be used as it is as it is, but by adding silica externally, the powder fluidity can be further improved, which is practically preferable.

  Silica includes those having a relatively large average particle diameter and those having a relatively small average particle diameter, and these may be used alone or in combination. As the external addition amount of silica, the charge amount is necessary and sufficient, and the photosensitive drum is not damaged and the environmental characteristics of the toner are not deteriorated. Therefore, 0.1 to 5 parts by weight with respect to 100 parts by weight of the toner particles. 0.0 part by weight is practically favorable.

  Hereinafter, the present invention will be described in detail with reference to synthesis examples, examples and comparative examples. In the examples, “part” and “%” are based on mass unless otherwise specified.

Synthesis Example 1 [Synthesis of polyester resin (A)]
83.4 g of ethylene glycol, 437.8 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average number of epoxies per molecule: 4), Cresol novolac type epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g and epoxidized fatty acid ester (epoxy Chemical linseed oil) Average number of epoxies per molecule: 7) Place 3.0 g in a 2 liter 4-necked flask and dissolve with heating, then add 440 g of terephthalic acid, and add titanium bisdioctyl pyrophosphate oxyacetate. Add 5g and gradually under nitrogen flow It was warm take-out by 20 hours at 255 ° C., to obtain a polyester resin (A1). The weight average molecular weight (Mw) of the polyester resin (A1) was 150,000, the number average molecular weight was 3,800, the glass transition temperature was 65 ° C., and the softening point was 131 ° C.

Synthesis example 2 (same as above)
83.7 g of ethylene glycol, 439.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average number of epoxies per molecule: 4), Cresol novolac epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g, epoxidized fatty acid ester (epoxy Soybean oil: Average number of epoxies per molecule: 5) Place 9.0 g in a 2 liter four-necked flask, dissolve with heating, add 434 g of terephthalic acid, and add titanium bisdioctyl pyrophosphate oxyacetate. Add 5g and gradually raise the temperature under nitrogen flow Extraction reacted for 18 hours at 255 ° C. so to obtain a polyester resin (A2). The weight average molecular weight (Mw) of the polyester resin (A2) was 240000, the number average molecular weight was 4300, the glass transition temperature was 65 ° C., and the softening point was 138 ° C.

Synthesis example 3 (same as above)
84.1 g of ethylene glycol, 441.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average epoxy number per molecule: 4), Cresol novolac epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g, epoxidized fatty acid ester (epoxy Oleic acid butyl ester, average number of epoxies per molecule: 1) 9.0 g was put into a 2 liter 4-necked flask and dissolved by heating. Then, 432.0 g of terephthalic acid was added, and titanium bisdioctyl pyrophosphate was added. Add 1.5g of oxyacetate and nitrogen Extraction gradually react 22 hours at 255 ° C. then warmed under stream to obtain a polyester resin (A3). The weight average molecular weight (Mw) of the polyester resin (A3) was 150,000, the number average molecular weight was 3700, the glass transition temperature was 65 ° C., and the softening point was 132 ° C.

Synthesis example 4 (same as above)
84.5 g of ethylene glycol, 443.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average epoxy number per molecule: 4), Cresol novolac epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g, epoxidized fatty acid ester (epoxy Linoleic acid butyl ester). Average number of epoxies per molecule: 2) Put 3.8 g in a 2 liter four-necked flask, dissolve with heating, add 435.0 g of terephthalic acid, and add 1.5 g of titanium bisdioctyl pyrophosphate oxyacetate. The polyester resin (A4) was obtained by gradually increasing the temperature in a nitrogen stream and reacting at 255 ° C. for 22 hours. The weight average molecular weight (Mw) of the polyester resin (A4) was 140000, the number average molecular weight was 4000, the glass transition temperature was 66 ° C., and the softening point was 133 ° C.

Synthesis example 5 (same as above)
75.0 g of ethylene glycol, 393.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average number of epoxies per molecule: 4), Cresol novolac epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g, epoxidized fatty acid ester (epoxy Oleic acid butyl ester, average number of epoxies per molecule: 1) Put 100.0 g in a 2 liter four-necked flask, dissolve with heating, add 400.0 g of terephthalic acid, and add titanium bisdioctyl pyrophosphate. Add 1.5g of oxyacetate Gradually warmed under a nitrogen stream taken out for 18 hours at 255 ° C., to obtain a polyester resin (A5). The weight average molecular weight (Mw) of the polyester resin (A5) was 130,000, the number average molecular weight was 4000, the glass transition temperature was 60 ° C., and the softening point was 130 ° C.

Synthesis example 6 (same as above)
75.2 g of ethylene glycol, 19.2 g of 2-butyl-2-ethyl-1,3-propanediol, 430.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, cresol novolak Type epoxy resin (average number of epoxies per molecule: 4) 14.5 g, cresol novolak type epoxy resin (average number of epoxies per molecule: 7.6), neodecanoic acid glycidyl ester (epoxy per molecule) Average number of groups: 1) 1.0 g, epoxidized fatty acid ester (epoxidized oleic acid butyl ester, average number of epoxies per molecule: 1) 9.0 g was placed in a 2 liter 4-necked flask and dissolved by heating. After adding 430.0 g of terephthalic acid, titanium Extraction gradually react 18 hours at 255 ° C. then warmed under a stream of nitrogen was charged with Le pyrophosphate oxyacetate 1.5g, to obtain a polyester resin (A6). The weight average molecular weight (Mw) of the polyester resin (A6) was 160000, the number average molecular weight was 3,300, the glass transition temperature was 64 ° C., and the softening point was 134 ° C.

Synthesis Example 7 [Synthesis of polyester resin for comparison (a1)]
Ethylene glycol 44.0 g, bisphenol A ethylene oxide 2 mol adduct 539 g, bisphenol A propylene oxide 2,2 mol adduct 20 g, cresol novolac type epoxy resin (average epoxy number per molecule: 4) 20 g, cresol novolak type epoxy 5.0 g of resin (average number of epoxies per molecule: 7.6) and 1.0 g of neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) are placed in a 2 liter four-necked flask, After heating and dissolving, 380 g of terephthalic acid is added, 0.05 g of titanium bisdioctyl pyrophosphate oxyacetate is added, the temperature is gradually raised under a nitrogen stream, and the reaction is carried out at 255 ° C. for 20 hours. (A1) was obtained. The weight average molecular weight (Mw) of the polyester resin (a1) was 150,000, the number average molecular weight was 3,500, the glass transition temperature was 65, and the softening point was 130.

Synthesis example 8 (same as above)
44.1 g of ethylene glycol, 540 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 2.5 g of cresol novolac type epoxy resin (average epoxy number per molecule: 7.6), Add 4.0 g of neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) to a 2 liter four-necked flask, dissolve with heating, add 380 g of terephthalic acid, and add titanium bisdioctyl pyrophosphate. 0.05 g of oxyacetate was added, the temperature was gradually raised under a nitrogen stream, the reaction was conducted at 255 ° C. for 20 hours, and the polyester resin (a2) for comparison was obtained. The weight average molecular weight (Mw) of the polyester resin (a2) was 200000, the number average molecular weight was 3100, the glass transition temperature was 64, and the softening point was 130.

Synthesis example 9 (same as above)
84.9 g of ethylene glycol, 445.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average number of epoxies per molecule: 4), Cresol novolac epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g, epoxidized fatty acid ester (epoxy Oleic acid butyl ester, average number of epoxies per molecule: 1) 0.5 g in a 2 liter four-necked flask and dissolved by heating, 400.0 g of terephthalic acid was added, and titanium bisdioctyl pyrophosphate was added. Add 1.5g of oxyacetate and nitrogen Extraction gradually react 21 hours at 255 ° C. then warmed under stream to obtain a binder resin (a3). The weight average molecular weight (Mw) of the polyester resin (a3) was 140000, the number average molecular weight was 3800, the glass transition temperature was 65 ° C., and the softening point was 132 ° C.

Synthesis example 10 (same as above)
65.0 g of ethylene glycol, 340.0 g of bisphenol A ethylene oxide 2 mol adduct, 20 g of bisphenol A propylene oxide 2,2 mol adduct, 11.5 g of cresol novolac type epoxy resin (average number of epoxies per molecule: 4), Cresol novolac epoxy resin (average number of epoxy per molecule: 7.6) 1.0 g, neodecanoic acid glycidyl ester (average number of epoxy groups per molecule: 1) 1.0 g, epoxidized fatty acid ester (epoxy Oleic acid butyl ester, average number of epoxies per molecule: 1) Add 200.0 g into a 2 liter 4-necked flask, dissolve with heating, add 361 g terephthalic acid, and add titanium bisdioctyl pyrophosphate oxyacetate Add 1.5g and nitrify Extraction gradually react 18 hours at 255 ° C. then warmed under stream to obtain a binder resin (a4). The weight average molecular weight (Mw) of the polyester resin (a4) was 200000, the number average molecular weight was 4000, the glass transition temperature was 56 ° C, and the softening point was 134 ° C.

Example 1
91 parts of polyester resin (A1), 4 parts of carbon black MA-11 (manufactured by Mitsubishi Chemical Corporation), 4 parts of carbana wax (manufactured by Nippon Seiki Co., Ltd.) and E-84 (charge control agent manufactured by Orient Chemical Industry Co., Ltd.) ) 1 part was mixed with a Henschel mixer and then melt-kneaded with a biaxial extruder to obtain a kneaded product (polyester resin composition for electrophotographic toner). The kneaded material thus obtained is cooled to room temperature, coarsely pulverized with a hammer mill, further finely pulverized with a jet mill, classified with an air classifier, and a 50% volume Coulter Counter D50 (BECKMAN COULTER) To obtain toner particles having a diameter of 7.5 μm. Next, 0.5 parts of silica RX200 (manufactured by Nippon Aerosil Co., Ltd.) was uniformly mixed with a Henschel mixer to prepare an electrophotographic toner 1.

  The electrophotographic toner 1 was evaluated for low-temperature fixability, hot offset resistance, and glossiness according to the following evaluation methods. In addition, the charge amount and charge stability of the polyester resin (A1) used in the production of the electrophotographic toner 1 and the evaluation of the dispersibility of the wax when producing the electrophotographic toner 1 were also evaluated according to the following evaluation methods. The evaluation results are shown in Table 1.

<Evaluation of low-temperature fixability>
The set temperature of the heat roll was changed from 120 ° C. to 140 ° C. in steps of 5 ° C., and solid printing was performed. When a solidity test is performed on a solid print portion and the image density before and after the test is measured with a Macbeth densitometer (RD-918), the ratio of the density value after peeling to the value before the test is displayed in%. The temperature at which the ratio becomes 80% or more was determined as the fixing start temperature. The lower this temperature, the better the low-temperature fixability of the electrophotographic toner. Evaluation criteria for low-temperature fixability were as follows. The fastness test was conducted using a Gakushin type friction fastness tester (load: 200 g, rubbing operation: 5 strokes).
A: When the fixing start temperature is less than 125 ° C. ○: When the fixing start temperature is 125 ° C. or more and less than 130 ° C. Δ: When the fixing start temperature is 130 ° C. or more and less than 135 ° C. ×: The fixing start temperature is 135 ° C. or more When the temperature is below 140 ° C

<Method for evaluating hot offset resistance>
When the set temperature of the hot roll was changed from 190 ° C. to 220 ° C. in increments of 5 ° C., the solid print part was offset again on the same paper and displayed at the lowest temperature that could be visually confirmed. The higher this temperature, the better the offset resistance.

◎: When the offset start temperature is 220 ° C or higher ○: When the offset start temperature is 210 ° C or higher and lower than 220 ° C △: When the offset start temperature is 200 ° C or higher and lower than 210 ° C ×: The offset start temperature is 190 ° C or higher When the temperature is less than 200 ° C. However, even when the offset does not occur at a high temperature, the resin itself acts as a wax and has poor fixability to a print medium, and is evaluated as x.

The low temperature fixability and hot offset resistance were evaluated under the following heat roller fixing machine conditions.
Roll material: Upper; Polytetrafluoroethylene, Lower; Silicone Upper roll load: 7Kg / 350mm
Nip width: 4mm
Paper threading speed: 90mm / sec

<Evaluation of glossiness>
Solid printing was performed with a commercially available printing machine to obtain a printed matter. The gloss of the printed surface was measured using a gloss meter manufactured by Nippon Denshoku Industries Co., Ltd. at a light projection / reception angle of 75 ° and evaluated according to the following criteria.
◎: Numerical value is 9 or more ○: Numerical value is 7 or more and less than 9 △: Numerical value is 5 or more and less than 7 ×: Numerical value is 3 or more and less than 5

<Evaluation of wax dispersibility>
A toner chip (before being coarsely pulverized and finely pulverized by a hammer mill in the toner production process) is pulverized by a sample mill, and then the chip is placed on the slide glass and sandwiched between the slide glasses. It is hot pressed at the temperature of the melt viscosity of the toner. The pressed sample was observed with an optical microscope. Evaluation was visual evaluation and evaluated as (circle), (triangle | delta), and x by the content rate whose WAX diameter is 10 micrometers or less.
90% ≦ ○
70% ≦ Δ <90% 50% ≦ × <70%.

<Evaluation of charge amount and charge stability>
Using a 210HS-2A blow-off charge measuring instrument manufactured by Trek Japan Co., Ltd., a mixture of 1.5 g of polyester resin (A1) and 48.5 g of ferrite carrier MF-100 (manufactured by Nippon Iron Flour Co., Ltd.) in a 50 ml plastic container The mixture was mixed for 1 minute, 10 minutes, 30 minutes, and 60 minutes with a tumbler shaker mixer and measured with a charge amount measuring instrument. The average of these values was taken as the charge amount. In addition, the difference between the maximum charge amount and the minimum charge amount is obtained for the charge amount measured by a charge amount measuring device after mixing for 10 minutes, 30 minutes and 60 minutes with a tumbler shaker mixer, and this value is evaluated for charge stability. It was. It represents that it is excellent in charging stability, so that this value is small.
Evaluation criteria for charge amount A: −35 μC / g or more ○: −30 μC / g or more, less than −35 μC / g Δ: −25 μC / g or more, less than −30 μC / g ×: −20 μC / g or more, −25 μC / g Less than

Evaluation criteria for charge stability ○: Difference between maximum charge amount and minimum charge amount is −1 μC / g or more and less than −5 μC / g Δ: Difference between maximum charge amount and minimum charge amount is −5 μC / g or more, −10 μC / g Less than g ×: The difference between the maximum charge amount and the minimum charge amount is −10 μC / g or more and less than −15 μC / g

Examples 2-5 and Comparative Examples 1-4
Electrophotographic toners 2 to 6 and comparative electrophotographic toners 1 'to 4' were obtained in the same manner as in Example 1 except that the polyester resin shown in Table 1 was used instead of the polyester resin (A1). Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1.

Claims (18)

  Polybasic acid (a1), polyhydric alcohol (a2), epoxy compound (a3) having one epoxy group, polyepoxy compound (a4) having 2 to 4 epoxy groups, having 5 or more epoxy groups A polyester resin obtained by reacting a polyepoxy compound (a5) and an epoxy compound (a6) other than the above (a3) to (a5) having a fatty acid ester structure, and the epoxy compound (a6) is converted into (a1) to ( A polyester resin composition for an electrophotographic toner, comprising a polyester resin (A) obtained by using 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of a6).   2. The polyester resin composition for electrophotographic toner according to claim 1, wherein the epoxy compound (a6) is obtained by epoxidizing a reaction product obtained by reacting an unsaturated fatty acid with an alcohol.   The polyester resin composition for electrophotographic toner according to claim 2, wherein the unsaturated fatty acid is an unsaturated fatty acid having 2 to 30 carbon atoms.   The polyester resin composition for electrophotographic toner according to claim 1, wherein the epoxy compound (a6) is epoxidized butyl oleate.   The polyester resin composition for electrophotographic toner according to claim 1, wherein the epoxy compound (a6) is obtained by epoxidizing vegetable oil. 6. The polyester resin composition for electrophotographic toner according to claim 5, wherein the epoxy compound (a6) is obtained by reacting a transesterified oil obtained by a reaction between a vegetable oil and an alcohol with a compound having an epoxy group.   The polyester resin composition for electrophotographic toner according to claim 6, wherein the epoxy compound (a6) is epoxidized soybean oil or epoxidized linseed oil.   2. The polyester resin composition for electrophotographic toner according to claim 1, wherein the polyepoxy compound (a5) having 5 or more epoxy groups is a novolak type epoxy resin having 5 to 15 epoxy groups.   The novolak type epoxy resin is a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, an alkylene oxide adduct type novolak type epoxy resin of bisphenol A, an alkylene oxide adduct type novolak type epoxy resin of bisphenol F, or a naphthalene type novolak type epoxy resin. 2. The polyester resin composition for electrophotographic toner according to claim 1, wherein the polyester resin composition is one or more novolak type epoxy resins selected from the group consisting of dicyclopentadiene type novolac type epoxy resins.   The epoxy compound (a3) is selected from the group consisting of phenyl glycidyl ether, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, glycidyl ether of alkylphenol alkylene oxide adduct, α-olefin oxide, and monoepoxy fatty acid alkyl ester. 2. The polyester resin composition for electrophotographic toner according to claim 1, wherein the polyester resin composition is one or more monoepoxy compounds.   The polyester resin composition for electrophotographic toner according to claim 1, wherein the epoxy compound (a4) is a bisphenol type epoxy resin.   The polyester resin composition for electrophotographic toner according to claim 1, wherein the polyhydric alcohol (a2) is a diol having a bisphenol skeleton.   The polyester resin composition for electrophotographic toner according to claim 8, wherein the diol having a bisphenol skeleton is an alkylene oxide adduct of bisphenols.   2. The polyester resin composition for electrophotographic toner according to claim 1, wherein the polyhydric alcohol (a2) is a mixture of a diol having a bisphenol skeleton and an aliphatic diol.   The polyester resin (A) is a polybasic acid (a1), a polyhydric alcohol (a2), an epoxy compound (a3), an epoxy compound (a4), an epoxy compound (a5), and an epoxy compound (a6) (a1). To (a6) in total of 100 parts by mass, 20 to 70 parts by mass, 30 to 70 parts by mass, 0.1 to 5 parts by mass, 0.1 to 10 parts by mass, 0.1 to 10 parts by mass, and The polyester resin composition for electrophotographic toner according to any one of claims 1 to 14, which is a polyester resin obtained by using 0.1 to 10 parts by mass.   The electron according to any one of claims 1 to 15, wherein a ratio [(Mw) / (Mn)] of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyester resin (A) is 3 to 70. Polyester resin composition for photographic toner.   The polyester resin composition for electrophotographic toner according to claim 16, wherein the polyester resin (A) has a weight average molecular weight (Mw) of 10,000 to 500,000. An electrophotographic toner comprising the polyester resin composition for an electrophotographic toner according to claim 1.