Binder resin composition for toner, toner particle, toner for electrostatic charge image development, and electrostatic charge image developer

Abstract

To provide a binder resin for toner having excellent low-temperature fixability.SOLUTION: A binder resin composition for toner contains an amorphous polyester resin, a crystalline polyester resin, and a crystallization accelerator. The crystallization accelerator is a compound having two or more ester linkages and a cyclic structure.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a binder resin composition for toner, toner particles, an electrostatic charge image developing toner, and an electrostatic charge image developer.

Background Art

[0002] In an image forming method through an electrostatic latent image (electrostatic charge image), generally, a two-component developer (toner) containing toner particles including a binder resin and a colorant and carrier particles for stirring and transporting the toner particles is used. In the above image forming method, for the purpose of speeding up image formation and reducing the load on the environment, etc., reduction of thermal energy (low-temperature fixing) at the time of fixing toner particles is required.

[0003] As a means for low-temperature fixing of toner particles, the use of a binder resin having both a crystalline resin part and an amorphous resin part has been proposed. In a binder resin having both a crystalline resin part and an amorphous resin part, when the melting point of the crystalline resin part in the binder resin is exceeded by heating during fixing, the crystalline resin part in the binder resin melts, and as a result, the crystalline resin part and the amorphous resin part are compatible, and low-temperature fixing of toner particles can be realized.

[0004] For further low-temperature fixing, toners to which a crystal nucleating agent that promotes crystallization is externally added have been proposed (for example, Patent Document 1). By externally adding a crystal nucleating agent to the surface of toner mother particles, crystallization of the crystalline polyester resin in the toner mother particles is promoted, and low-temperature fixing is realized.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved by the present invention is to provide a binder resin for toner excellent in low-temperature fixability.

Means for Solving the Problem

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that a toner having excellent low-temperature fixability can be obtained by using a binder resin composition for toner containing a crystallization accelerator having a specific structure, and have completed the present invention.

[0008] That is, the present invention relates to the following binder resin composition for toner and the like. 1. A binder resin composition for toner containing an amorphous polyester resin, a crystalline polyester resin, and a crystallization accelerator, wherein the crystallization accelerator is a compound having two or more ester bonds and a cyclic structure. 2. The binder resin composition for toner according to 1, wherein the crystallization accelerator is an aliphatic ester compound having a cyclic ether and two or more ester bonds, or an aliphatic diester compound having at least one terminal blocked with an aromatic ring. 3. The binder resin composition for toner according to 1 or 2, wherein the crystallization accelerator is a compound represented by the following general formula (1-1) and / or a compound represented by the following general formula (1-2).

Chemical formula

Advantages of the Invention

[0009] According to the present invention, a toner binder resin excellent in low-temperature fixability can be provided.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications without impairing the effects of the present invention. In the present application, when expressed as "in the range of XX to XX", it means XX or more and XX or less. Also, the compounds in this specification may be derived from fossil resources or may be derived from biological resources.

[0011] [Binder resin composition for toner] The binder resin composition for toner of the present invention contains an amorphous polyester resin, a crystalline polyester resin, and a crystallization accelerator, and the crystallization accelerator is a compound having two or more ester bonds and a cyclic structure. By containing a crystallization accelerator having a specific structure, the toner particles obtained using the binder resin composition for toner of the present invention can achieve low-temperature fixing. Hereinafter, each component of the binder resin composition for toner of the present invention will be described.

[0012] (Crystalline polyester resin) The crystalline polyester resin is a crystalline polyester resin. Here, "crystalline" means that in differential scanning calorimetry (DSC), the polyester resin shows a distinct endothermic peak rather than a stepwise change in the amount of heat absorption. Specifically, when the differential scanning calorimetry described in the examples is performed, a polyester resin that shows a distinct endothermic peak is a crystalline polyester resin.

[0013] The acid value of the crystalline polyester resin is, for example, in the range of 4.0 to 16.0, preferably in the range of 5.0 to 15.0, and more preferably in the range of 7.5 to 15.0. The acid value of the crystalline polyester resin is measured by the method described in the examples.

[0014] The melting point of the crystalline polyester resin is preferably 55 to 90°C, more preferably 61 to 88°C, and even more preferably 64 to 85°C. The melting point of the crystalline polyester resin is measured by the method described in the examples.

[0015] The weight average molecular weight (Mw) of the crystalline polyester resin is, for example, in the range of 5,000 to 100,000, preferably in the range of 10,000 to 60,000, more preferably in the range of 15,000 to 40,000, and even more preferably in the range of 19,000 to 39,000. The number average molecular weight (Mn) of the crystalline polyester resin is, for example, in the range of 1,000 to 50,000, preferably in the range of 2,000 to 10,000, more preferably in the range of 3,000 to 10,000, and even more preferably in the range of 4,000 to 9,900. The weight average molecular weight and the number average molecular weight of the crystalline polyester are measured by the method described in the examples.

[0016] Examples of the crystalline polyester resin include a crystalline polyester resin obtained by using at least an aliphatic dibasic acid (c1) and an aliphatic diol (c2) as reaction components. The polyester resin is usually obtained as an amorphous polyester resin, but a crystalline polyester resin can be obtained by using a combination of an aliphatic dibasic acid (c1) and an aliphatic diol (c2) as reaction components. It is more preferable that both the aliphatic dibasic acid (c1) and the aliphatic diol (c2) have high symmetry and / or a long hydrocarbon chain.

[0017] Examples of the aliphatic dibasic acid (c1) include aliphatic dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, etc. Among these, aliphatic dibasic acids having 6 to 18 carbon atoms are preferable, and adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid are more preferable. These aliphatic dibasic acids may be used alone or in combination of two or more.

[0018] Examples of the aliphatic diol (C2) include linear alkylene diols such as ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol; ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol; modified polyether polyols obtained by ring-opening polymerization of the linear alkylene diol and various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether; lactone-based polyester polyols obtained by polycondensation reaction of the linear alkylene diol and various lactones such as ε-caprolactone, and the like. These aliphatic diols (C2) may be used alone or in combination of two or more.

[0019] As the aliphatic diol (C2), linear alkylene diols having 4 to 18 carbon atoms are preferred, and 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol are more preferred. All of these are aliphatic diols with high symmetry.

[0020] The crystalline polyester resin may use an aliphatic monobasic acid (c3) having 8 to 32 carbon atoms as a reactive component. The crystalline polyester resin is a crystalline polyester resin obtained using at least an aliphatic dibasic acid (c1), an aliphatic diol (c2), and an aliphatic monobasic acid (c3) having 8 to 32 carbon atoms as reactive components, and the terminals of the crystalline polyester resin are blocked with the aliphatic monobasic acid having 8 to 32 carbon atoms, thereby increasing the crystallinity of the crystalline polyester resin.

[0021] The aliphatic monobasic acid (c3) having 8 to 32 carbon atoms is preferably an aliphatic monobasic acid having 22 to 32 carbon atoms, and more preferably one or more selected from behenic acid, tricosylic acid, lignoceric acid, cerotic acid, montanic acid, and melissic acid. The aliphatic monobasic acids (c3) may be used singly or in combination of two or more.

[0022] The crystalline polyester resin may use a polyfunctional epoxy compound (c4) as a reaction component. Examples of the polyfunctional epoxy compound (C4) include aliphatic diglycidyl ethers such as ethylene glycol diglycidyl ether, 2,2'-(2,6-dioxaheptane-1,7-diyl) bisoxirane, 1,4-bis(glycidyloxy) butane, 2,3-butylene glycol diglycidyl ether, 1,5-pentylene glycol diglycidyl ether, 1,6-bis(glycidyloxy) hexane, 1,7-heptylene glycol diglycidyl ether, and 1,8-octylene glycol diglycidyl ether; aliphatic polyglycidyl ethers having three or more epoxy groups in the molecular structure such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether; epoxy group-containing vinyl polymers obtained by polymerizing glycidyl group-containing compounds such as glycidyl (meth)acrylate and glycidyl α-ethyl (meth)acrylate with aliphatic compounds containing vinyl groups such as butadiene, methyl (meth)acrylate, ethyl (meth)acrylate, and dimethyl fumarate; aromatic diglycidyl ethers such as bisphenol A diglycidyl ether, bisphenol B diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, 1,4-naphthalenediol diglycidyl ether, 1,5-naphthalenediol diglycidyl ether, 2,6-naphthalenediol diglycidyl ether, and naphthalene-2,6-dimethanol diglycidyl ether; aromatic polyglycidyl ethers having three or more epoxy groups in the molecular structure such as 4,4',4''-methylidynetrisphenol triglycidyl ether; novolak-type epoxy resins such as phenol novolak-type epoxy resins, cresol novolak-type epoxy resins, and novolak-type epoxy resins of bisphenols; epoxy group- and aromatic ring-containing vinyl polymers obtained by polymerizing glycidyl group-containing compounds such as glycidyl (meth)acrylate and glycidyl α-ethyl (meth)acrylate with aromatic compounds containing vinyl groups such as styrene and, if necessary, aliphatic compounds containing vinyl groups such as butadiene, methyl (meth)acrylate, ethyl (meth)acrylate, and dimethyl fumarate. Among these, novolak-type epoxy resins are preferred. These polyfunctional epoxy compounds (c4) may be used alone or in combination of two or more.

[0023] The crystalline polyester resin may, if necessary, use aliphatic monocarboxylic acids having 1 to 7 carbon atoms such as methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, etc.; aromatic dicarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, etc. as reaction components. These acid components other than the aliphatic dibasic acid (c1) and the aliphatic monobasic acid (c3) having 8 to 32 carbon atoms may be used alone or in combination of two or more. By using acid components other than the aliphatic dibasic acid (c1) and the aliphatic monobasic acid (c3) having 8 to 32 carbon atoms, the melting point of the crystalline polyester resin can be adjusted.

[0024] The crystalline polyester resin may, if necessary, use monoalcohols such as hexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-heptadecanol, n-octadecanol, n-nonadecanol, eicosanol, etc.; polyfunctional aliphatic polyols having 3 or more functions such as trimethylolethane, trimethylolpropane, 2,2,4-trimethyl-1,3-pentanediol, glycerin, hexanetriol, pentaerythritol, etc.; bisphenols such as bisphenol A, bisphenol B, bisphenol F, bisphenol S, etc.; alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc. to the bisphenols, etc. as reaction components. These alcohol components other than the aliphatic diol (c2) may be used alone or in combination of two or more. By using alcohol components other than the aliphatic diol (c2), the melting point of the crystalline polyester resin can be adjusted.

[0025] The crystalline polyester resin may use a monoepoxy compound as a reaction component as necessary. Examples of the monoepoxy compound include aliphatic monoglycidyl ethers such as butyl glycidyl ether, 2-ethoxyethyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, 2-ethylhexyl glycidyl ether, nonyl glycidyl ether, decyl glycidyl ether; monoglycidyl ethers having an aromatic ring in the molecular structure such as phenyl glycidyl ether, cresyl glycidyl ether, 4-butylphenyl glycidyl ether, glycidyl-2-naphthyl ether; aliphatic monoglycidyl esters such as cyclopropylmethyl 2,2-dimethylpropionate, glycidyl neodecanoate, glycidyl stearate; aromatic α-olefin oxides such as styrene oxide, and the like. These monoepoxy compounds may be used alone or in combination of two or more.

[0026] When the crystalline polyester resin is a crystalline polyester resin obtained using at least an aliphatic dibasic acid (c1) and an aliphatic diol (c2) as reaction components, in the crystalline polyester resin, the molar ratio [(N COOH ) / (N OH )] of the number of moles (N COOH ) of carboxyl groups contained in the aliphatic dibasic acid (c1) to the number of moles (N OH ) of hydroxyl groups contained in the aliphatic diol (c2) is in the range of 1.00 / 0.95 to 1.00 / 1.00, and it is preferably a crystalline polyester resin obtained by reacting at a temperature of 180 to 260°C in the presence of an esterification catalyst such as dibutyltin oxide.

[0027] When the crystalline polyester resin further uses an aliphatic monobasic acid (C3) as a reaction component, the usage amount of the aliphatic monobasic acid (C3) is in the range of, for example, 1 to 10% by mass of the total reaction components (the total of the aliphatic dibasic acid (C1), the aliphatic diol (C2) and the aliphatic monobasic acid (C3)), preferably in the range of 2 to 8% by mass, more preferably in the range of 2.5 to 7.5% by mass.

[0028] The content of the crystalline polyester resin is in the range of, for example, 5 to 30% by mass of the total of the crystalline polyester resin, the amorphous polyester resin and the crystallization accelerator, preferably in the range of 7 to 25% by mass, more preferably in the range of 10 to 25% by mass, and still more preferably in the range of 10 to 20% by mass.

[0029] (Amorphous polyester resin) The amorphous polyester resin is an amorphous polyester resin. Here, "amorphous" means not showing a distinct endothermic peak in differential scanning calorimetry (DSC). Specifically, when performing the differential scanning calorimetry described in the examples, a polyester resin that does not show a distinct endothermic peak is an amorphous polyester resin.

[0030] The acid value of the amorphous polyester resin is in the range of, for example, 4.0 to 16.0, preferably in the range of 5.0 to 15.0, more preferably in the range of 8.1 to 15.0. In order to maintain the emulsifiability of the block copolymer, it is more preferable that the lower limit of the acid value of the amorphous polyester is more than 10.0. The acid value of the amorphous polyester is measured by the method described in the examples.

[0031] The amorphous polyester resin is in a glassy state with low molecular mobility and no fluidity under low-temperature environments. However, when the temperature rises, its molecular mobility increases, and it has the property of changing to a rubbery state with reduced rigidity and viscosity and increased fluidity. At this time, the temperature at which the transition occurs from the glassy state to the rubbery state is called the glass transition temperature (Tg). The glass transition temperature of the amorphous polyester resin is, for example, 45 to 100 °C, preferably 50 to 90 °C, more preferably 50 to 80 °C, and still more preferably 50 to 70 °C. The glass transition temperature of the amorphous polyester resin is measured by the method described in the examples.

[0032] The weight average molecular weight (Mw) of the amorphous polyester resin is, for example, 3,000 to 150,000, preferably 4,000 to 80,000, more preferably 10,000 to 60,000, and still more preferably 10,500 to 44,000. The number average molecular weight (Mn) of the amorphous polyester resin is, for example, 1,000 to 50,000, preferably 2,000 to 10,000, more preferably 2,500 to 8,000, and still more preferably 2,500 to 6,000. The weight average molecular weight and the number average molecular weight of the amorphous polyester are measured by the method described in the examples.

[0033] Examples of the amorphous polyester resin include an amorphous polyester resin obtained using at least dibasic acid (a1) and diol (a2) as reaction components. The reaction components of the amorphous polyester resin are preferably a combination of a dibasic acid and a diol other than the combination of the aliphatic dibasic acid (c1) and the aliphatic diol (c2) which are the reaction components of the crystalline polyester.

[0034] Examples of the dibasic acid (a1) include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, dodecylsuccinic acid, dodecylsuccinic anhydride, dodecenylsuccinic acid, dodecenylsuccinic anhydride, octenylsuccinic acid, and octenylsuccinic anhydride; aliphatic unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, citraconic acid, dimethylmaleic acid, cyclopentene-1,2-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, fumaric acid, mesaconic acid, itaconic acid, and glutaconic acid; and aromatic dicarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, and orthophthalic acid. Among these, the dibasic acid (a1) preferably contains the aromatic dicarboxylic acid, and more preferably contains terephthalic acid and / or isophthalic acid. These dibasic acids may be used alone or in combination of two or more.

[0035] Examples of the diol (a2) include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3 - propanediol, 1,2,2 - trimethyl - 1,3 - propanediol, 2,2 - dimethyl - 3 - isopropyl - 1,3 - propanediol, 1,4 - butanediol, 1,3 - butanediol, 3 - methyl - 1,3 - butanediol, 1,5 - pentanediol, 3 - methyl 1,5 - pentanediol, neopentyl glycol, 1,6 - hexanediol, 1,4 - bis(hydroxymethyl)cyclohexane; ether glycols such as polyoxyethylene glycol, polyoxypropylene glycol; modified polyether polyols obtained by ring - opening polymerization of the above - mentioned aliphatic diols and various cyclic ether - bond - containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether; lactone - based polyester polyols obtained by polycondensation reaction of the above - mentioned aliphatic diols and various lactones such as ε - caprolactone; bisphenols such as bisphenol A, bisphenol B, bisphenol F, bisphenol S; and alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc. to the above - mentioned bisphenols. Among these, the diol (a2) preferably contains an alkylene oxide adduct of the bisphenol. These diols may be used alone or in combination of two or more.

[0036] The amorphous polyester resin may, if necessary, use, as reaction components, monocarboxylic acids such as methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, benzoic acid, para-t-butylbenzoic acid, etc.; polycarboxylic acids having three or more functional groups such as 1,2,5-hexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, trimellitic acid, trimellitic anhydride, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, pyromellitic anhydride, etc. These acid components other than the dibasic acid (a1) may be used alone or in combination of two or more. By using an acid component other than the dibasic acid (a1), the glass transition point of the amorphous polyester resin can be adjusted.

[0037] The amorphous polyester resin may, if necessary, use, as reaction components, monoalcohols such as hexanol, 2-ethylhexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-heptadecanol, n-octadecanol, n-nonadecanol, eicosanol, 5-ethyl-2-nonanol, trimethylnonyl alcohol, 2-hexyldecanol, 3,9-diethyl-6-tridecanol, 2-isooctylisoundecanol, 2-octyldodecanol, 2-decyltetradecanol, etc.; polyols having three or more functional groups such as trimethylolethane, trimethylolpropane, 2,2,4-trimethyl-1,3-pentanediol, glycerin, hexanetriol, pentaerythritol, etc. These alcohol components of the diol (a2) may be used alone or in combination of two or more. By using an alcohol component other than the diol (a2), the glass transition point of the amorphous polyester resin can be adjusted.

[0038] The amorphous polyester resin may, if necessary, use a polyfunctional epoxy compound as a reaction component. As the polyfunctional epoxy compound that can be used in the amorphous polyester resin, the same compounds as those that can be used in the crystalline polyester resin (c3) can be used.

[0039] The amorphous polyester resin may, if necessary, use a monoepoxy compound as a reaction component. Examples of the monoepoxy compound include aliphatic monoglycidyl ethers such as butyl glycidyl ether, 2-ethoxyethyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, 2-ethylhexyl glycidyl ether, nonyl glycidyl ether, and decyl glycidyl ether; monoglycidyl ethers having an aromatic ring in the molecular structure such as phenyl glycidyl ether, cresyl glycidyl ether, 4-butylphenyl glycidyl ether, and glycidyl-2-naphthyl ether; aliphatic monoglycidyl esters such as cyclopropylmethyl 2,2-dimethylpropionate, glycidyl neodecanoate, and glycidyl stearate; and aromatic α-olefin oxides such as styrene oxide. These monoepoxy compounds may be used alone or in combination of two or more.

[0040] When the amorphous polyester resin is an amorphous polyester resin obtained using at least a dibasic acid (a1) and a diol (a2) as reaction components, in the amorphous polyester resin, the ratio [(N COOH ) / (N OH )] of the number of moles (N COOH ) of the carboxyl groups contained in the dibasic acid (a1) to the number of moles (N OH ) of the hydroxyl groups contained in the diol (a2) is in the range of 1.00 / 0.96 to 1.00 / 1.04, and it is preferably an amorphous polyester resin obtained by reacting at a temperature of 180 to 260°C in the presence of an esterification catalyst such as dibutyltin oxide.

[0041] The content of the amorphous polyester resin is in the range of, for example, 50 to 90% by mass, preferably 55 to 90% by mass, and more preferably 60 to 90% by mass of the total of the crystalline polyester resin, the amorphous polyester resin, and the crystallization accelerator.

[0042] (Crystallization accelerator) The crystallization accelerator is a compound having two or more ester bonds and a cyclic structure. Here, the "cyclic structure" means any of an aromatic ring structure, an alicyclic structure, an aliphatic heterocyclic structure, and an aromatic heterocyclic structure. It is presumed that the movement of the polymer (amorphous polyester resin and crystalline polyester resin) is activated by the crystallization accelerator having the above structure, and the polymer is easily folded regularly, thereby promoting crystallization.

[0043] The crystallization accelerator is preferably a cyclic ether and an aliphatic ester compound having two or more ester bonds, or an aliphatic diester compound in which at least one end is blocked by an aromatic ring, and more preferably an aliphatic diester compound in which one end is blocked by an aromatic ring.

[0044] Regarding the above "cyclic ether and aliphatic ester compound having two or more ester bonds", examples of the cyclic ether include an epoxy ring and an oxetanyl ring. Further, the aliphatic ester compound means a compound in which a portion other than the cyclic ether and the ester bond (-C(=O)-O-) is composed of a carbon-carbon bond and an arbitrary ether bond (-O-).

[0045] Regarding the above "aliphatic diester compound in which at least one end is blocked by an aromatic ring", examples of the aromatic ring include a benzene ring, a naphthalene ring, and an anthracene ring. Further, the aliphatic diester compound means a compound in which a portion other than the terminal aromatic ring and the ester bond (-C(=O)-O-) is composed of a carbon-carbon bond and an arbitrary ether bond (-O-).

[0046] The crystallization accelerator is preferably a compound represented by the following general formula (1-1) and / or a compound represented by the following general formula (1-2).

[0047]

Chemical formula

[0048] L 1 The n1-valent aliphatic hydrocarbon group of L, for example, when n1 is 2, the divalent aliphatic hydrocarbon group is preferably an alkylene group having 1 to 50 carbon atoms or an alkyleneoxy group having 1 to 50 carbon atoms.

[0049] L 1Examples of the alkylene group having 1 to 50 carbon atoms include a methylene group, an ethylene group, an n-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, an n-octylene group, an n-nonylene group, an n-decylene group, an n-dodecylene group, an isopropylene group, a 2-methylpropylene group, a 2-methylhexylene group, a tetramethylethylene group, and the like.

[0050] L 1 The alkylene group having 1 to 50 carbon atoms is preferably an alkylene group having 1 to 15 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and still more preferably a methylene group, an ethylene group, an n-propylene group or an isopropylene group.

[0051] L 1 The alkyleneoxy group having 1 to 50 carbon atoms is, for example, a group in which one or more -CH2- in the above alkylene group are substituted with an ether bond (-O-). L 1 The alkyleneoxy group having 1 to 50 carbon atoms is preferably an alkyleneoxy group having 1 to 15 carbon atoms, more preferably an alkyleneoxy group having 1 to 8 carbon atoms, and still more preferably a methyleneoxy group, an ethyleneoxy group, a propyleneoxy group, an oxytrimethylene group, a butyleneoxy group, an oxytetramethylene group, a pentyleneoxy group, a heptyleneoxy group or an octyleneoxy group.

[0052] L 1 When the n1-valent aliphatic hydrocarbon group is a trivalent or higher aliphatic hydrocarbon group, the trivalent or higher aliphatic hydrocarbon group is, for example, an aliphatic hydrocarbon group in which a hydrogen atom bonded to a carbon atom of the divalent aliphatic hydrocarbon group described above is replaced with a bond so as to have a corresponding valence.

[0053] R 1The alkyl group having 1 to 24 carbon atoms may be any of a linear alkyl group, a branched alkyl group, and a cyclic alkyl group, and specific examples include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-hexyl group, a cyclohexyl group, an n-octyl group, and a hexadecyl group. R 1 The alkyl group having 1 to 24 carbon atoms is preferably an alkyl group having 6 to 24 carbon atoms.

[0054] R 1 The alkyl group having 1 to 24 carbon atoms may have an ether bond (-O-), or may be a group in which one or more -CH2- in the alkyl group is substituted with an ether bond (-O-).

[0055] R 1 The alkyl group having 2 to 24 carbon atoms and an epoxy ring is R 1 In the alkyl group having 2 to 24 carbon atoms, two adjacent carbon atoms form an epoxy ring. R 1 The number of epoxy rings in the alkyl group having 2 to 24 carbon atoms and having an epoxy ring is not particularly limited as long as it is 1 or more, and may be, for example, 1 to 3 epoxy rings. R 1 The alkyl group having 2 to 24 carbon atoms and an epoxy ring is preferably an alkyl group having 6 to 24 carbon atoms and an epoxy ring.

[0056] L 21 , L 22 and L 23 The alkylene group having 1 to 12 carbon atoms and the alkyleneoxy group having 1 to 12 carbon atoms are respectively represented by L 1 The alkylene group and alkyleneoxy group are the same as those in the above.

[0057] R 21 and R 22 Examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a naphthyl group, an anthracen-1-yl group, and a phenanthrene-1-yl group. The aryl group having 6 to 18 carbon atoms may be further substituted with an alkyl group having 1 to 6 carbon atoms.

[0058] R 21 and R 22 The alkyl group having 1 to 12 carbon atoms is the same as the alkyl group of R 1 is the same.

[0059] R 21 and R 22 are preferably such that one is an aryl group having 6 to 18 carbon atoms and the other is an alkyl group having 1 to 12 carbon atoms.

[0060] Specific examples of the crystallization accelerator are shown below.

[0061]

Chemical formula

[0062] The crystallization accelerator can be produced by a known method, and a commercially available product may be used.

[0063] The content of the crystallization accelerator is in the range of, for example, 0.5 to 15% by mass of the total of the crystalline polyester resin, the amorphous polyester resin, and the crystallization accelerator, preferably in the range of 0.5 to 12% by mass, and more preferably in the range of 1 to 10% by mass.

[0064] In addition, when the crystallization accelerator is "an aliphatic diester compound having one end sealed with an aromatic ring", the content of the aliphatic diester compound is preferably in the range of 0.5 to 5% by mass of the total of the crystalline polyester resin, the amorphous polyester resin, and the crystallization accelerator, and more preferably in the range of 0.5 to 3% by mass. On the other hand, when the crystallization accelerator is "a compound other than the aliphatic diester compound having one end sealed with an aromatic ring", the content of the compound is preferably in the range of 1 to 12% by mass of the total of the crystalline polyester resin, the amorphous polyester resin, and the crystallization accelerator, and more preferably in the range of 1 to 10% by mass or 3 to 12% by mass.

[0065] [Toner for electrostatic charge image development] The toner for electrostatic charge image development of the present invention contains the binder resin composition for toner of the present invention. The toner for electrostatic charge image development of the present invention (hereinafter sometimes simply referred to as "the toner of the present invention") contains the binder resin composition for toner of the present invention, and thus is excellent in both low-temperature fixability and charging performance.

[0066] The content of the binder resin composition of the present invention in the toner of the present invention is not particularly limited, but is preferably 10 to 95% by mass, more preferably 25 to 90% by mass, and even more preferably 45 to 85% by mass of the total solid mass of the toner. When the content of the binder resin composition of the present invention is within the above range, excellent low-temperature fixability and charging performance can be obtained.

[0067] (Other binder resins) The toner of the present invention only needs to contain the binder resin composition of the present invention, and may also contain other binder resins other than the binder resin composition of the present invention. The other binder resins are not particularly limited, and examples thereof include polystyrene, styrene-butadiene polymers, styrene-acrylic polymers, polyester resins, etc. These other binder resins may be further modified with urethane, urea, epoxy, etc.

[0068] (Colorant) The toner of the present invention preferably contains a colorant for the purpose of coloring the obtained image. The colorant may be appropriately selected from known colorants according to the purpose, and pigments and dyes of various colors can be used.

[0069] Examples of the pigment include black pigments such as carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, non-magnetic ferrite, and magnetite; yellow pigments such as lead yellow, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, threne yellow, quinoline yellow, and permanent yellow NCG; orange pigments such as red lead yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, Balkan orange, benzidine orange G, indanthrene brilliant orange RK, and indanthrene brilliant orange GK; red pigments such as red lead, cadmium red, red lead oxide, mercury sulfide, watching red, permanent red 4R, resorcin red, brilliant carmine 3B, brilliant carmine 6B, pyrazolone red, rhodamine lake B, lake red C, rose bengal, eosin red, and alizarin lake; blue pigments such as ultramarine, cobalt blue, alkali blue lake, Victoria blue lake, fast sky blue, indanthrene blue BC, ultramarine blue, phthalocyanine blue, and phthalocyanine green; purple pigments such as manganese violet, fast violet B, and methyl violet lake; green pigments such as chromium oxide, chrome green, pigment green B, malachite green lake, and fanal yellow green G; white pigments such as zinc white, titanium oxide, antimony white, and zinc sulfide; and extender pigments such as barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white, etc. These pigments may be used alone or in combination of two or more.

[0070] Examples of the dye include various dyes such as basic dyes, acidic dyes, disperse dyes, and direct dyes. Specific examples of the dye include nigrosine, methylene blue, rose bengal, and quinoline yellow, etc. These dyes may be used alone or in combination of two or more.

[0071] The colorant may be used, for example, as a dispersion of colorant particles. As a method for preparing a dispersion of colorant particles, there are media type dispersers such as rotary shear homogenizers, ball mills, sand mills, attritors, etc.; high-pressure opposed collision type dispersers, etc. are used to form a dispersion of colorant particles, or a polar surfactant is added and the colorant particles are dispersed with a homogenizer, etc.

[0072] The content of the colorant in the toner of the present invention is preferably 0.1 to 40% by mass, more preferably 0.5 to 20% by mass, of the total solid mass of the toner in order to ensure color development during fixing. However, when a magnetic material is used as the black colorant, the content of the black colorant is preferably 12 to 48% by mass, more preferably 15 to 40% by mass, of the total solid mass of the toner.

[0073] By appropriately selecting the type of the colorant, various color toners such as yellow toner, magenta toner, cyan toner, black toner, etc. can be obtained.

[0074] (Release agent) The toner of the present invention preferably contains a release agent for the purpose of improving releasability. Examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene, polybutene, etc.; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide, etc.; plant waxes such as carnauba wax, rice wax, candelilla wax, wood wax, jojoba oil, etc.; animal waxes such as beeswax, etc.; mineral and petroleum waxes such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc.; ester waxes such as fatty acid esters, montanic acid esters, carboxylic acid esters, etc. These release agents may be used alone or in combination of two or more.

[0075] The addition amount of the release agent is preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 15% by mass, based on the total amount of toner particles.

[0076] The toner of the present invention may contain other components other than the binder resin, colorant, and release agent, as long as the effects of the present invention are not impaired. Examples of the other components include known additives such as inorganic particles, organic particles, charge control agents, and internal additives.

[0077] The inorganic particles are generally used for the purpose of improving the fluidity of the toner. Examples of the inorganic particles include particles such as silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride, red iron oxide, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among these, silica particles are preferred, and hydrophobized silica particles are particularly preferred.

[0078] The organic particles are used for the purpose of improving cleaning properties, transfer properties, chargeability, etc. Examples of the organic particles include particles such as polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and polystyrene-acrylic copolymer.

[0079] Examples of the charge control agent include metal salicylates, metal-containing azo compounds, nigrosine, and quaternary ammonium salts.

[0080] Examples of the internal additive include magnetic materials such as metals, alloys, or compounds containing these metals, such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese.

[0081] The toner of the present invention can be manufactured by known methods, for example, kneading and pulverizing method, emulsion aggregation method, suspension polymerization method, dissolution suspension method, and the emulsion aggregation method is preferred. The kneading and pulverizing method is a method of kneading a binder resin, a colorant, a release agent, a charge control agent, etc., and pulverizing and classifying the obtained kneaded product to produce toner mother particles. The obtained toner mother particles may further be subjected to mechanical impact force or thermal energy to change the shape. The emulsion aggregation method is a method of mixing a dispersion liquid in which a binder resin is emulsified and dispersed with a dispersion liquid of a colorant, a release agent, a charge control agent, etc., aggregating and heat-fusing them to produce toner mother particles. The suspension polymerization method is a method of suspending a polymerizable monomer for obtaining a binder resin and a solution of a colorant, a release agent, a charge control agent, etc. in an aqueous solvent to produce toner mother particles. The dissolution suspension method is a method of suspending a binder resin and a solution of a colorant, a release agent, a charge control agent, etc. in an aqueous solvent to granulate toner mother particles.

[0082] Using the toner mother particles obtained by the above method as a core, aggregating particles may be attached to the core surface and heat-fused to obtain a toner having a core-shell structure. The toner of the present invention preferably has a structure in which toner mother particles and external additives (for example, inorganic particles and / or organic particles) are attached to the surface of the toner mother particles, and the toner mother particles contain the binder resin composition for the toner of the present invention.

[0083] [Electrostatic charge image developer] The toner of the present invention is suitably used as an electrostatic charge image developer. The electrostatic charge image developer of the present invention may include the toner of the present invention. For example, when the toner of the present invention is used alone as an electrostatic charge image developer, the electrostatic charge image developer of the present invention becomes a one-component electrostatic charge image developer, and when the toner of the present invention is used in combination with a known carrier as an electrostatic charge image developer, it becomes a two-component electrostatic charge image developer.

[0084] Examples of the core material of the carrier include magnetic metals such as iron, steel, nickel, and cobalt; alloys of the magnetic metals with manganese, chromium, rare earths, etc.; and magnetic oxides such as ferrite and magnetite.

[0085] The surface of the core material of the carrier may be coated with a resin. Examples of the resin for coating the core material surface include polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, and polyvinyl ketone; vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of organosiloxane bonds or modified products thereof; fluorine-based resins such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and polychlorotrifluoroethylene; silicone resin; polyester; polyurethane; polycarbonate; phenol resin; amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, and polyamide resin; and epoxy resin. These resins may be used alone or in combination of two or more.

[0086] When the carrier is a carrier composed of a core material coated with a resin, it is preferable that resin particles and / or conductive particles are dispersed in the resin coating layer. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. These resin particles may be used alone or in combination of two or more. Examples of the conductive particles include metal particles such as gold, silver, and copper; carbon black particles; and particles whose surfaces such as titanium oxide, zinc oxide, barium sulfate, aluminum borate, and potassium titanate are coated with carbon black or metal. These conductive particles may be used alone or in combination of two or more.

[0087] The toner of the present invention or the electrostatic charge image developer of the present invention is used, for example, in a state of being housed in a cartridge. By housing the toner of the present invention or the electrostatic charge image developer of the present invention in a cartridge, it becomes detachable from the image forming apparatus, and the supply of the toner or the electrostatic charge image developer to the image forming apparatus can be facilitated.

Examples

[0088] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Note that the present invention is not limited to the following Examples.

[0089] (Acid value and hydroxyl value) The acid value and hydroxyl value of the resin were measured in accordance with JIS K0070-1992 (neutralization titration method).

[0090] (Number average molecular weight and weight average molecular weight) The number average molecular weight (Mn) and weight average molecular weight (Mw) of the resin were evaluated under the following conditions using gel permeation chromatography (GPC) method. Measuring device: HLC-8120GPC manufactured by Tosoh Corporation Column: TSK-GUARDCOLUMN HXL-H manufactured by Tosoh Corporation + TSK-GEL G5000HXL manufactured by Tosoh Corporation + TSK-GEL G4000HXL manufactured by Tosoh Corporation + TSK-GEL G3000HXL manufactured by Tosoh Corporation + TSK-GEL G2000HXL manufactured by Tosoh Corporation Detector: RI (differential refractometer) Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation Column temperature: 40 °C Solvent: Tetrahydrofuran Flow rate: 1.0 ml / min Standard: Monodisperse polystyrene Sample: A 0.5 mass% tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

[0091] (Melting point) The melting point of the resin was determined under the following conditions using the differential scanning calorimetry (DSC) method. Measuring device: DSC-220C manufactured by Seiko Instruments Inc. Data processing: EXSTAR6000 PC station Measurement conditions: (1) Heating from 20°C to 150°C (10°C / min) (2) Holding at 150°C for 10 minutes (3) Cooling from 150°C to 0°C (10°C / min) (4) Holding at 0°C for 10 minutes (5) Heating from 0°C to 150°C (10°C / min) Analysis: In (5), the maximum endothermic peak temperature of the heat of fusion was defined as the melting point.

[0092] (Glass transition temperature) The glass transition temperature of the resin was determined under the following conditions using the differential scanning calorimetry (DSC) method. Measuring device: DSC-220C manufactured by Seiko Instruments Inc. Data processing: EXSTAR6000 PC station Measurement conditions: (1) Heating from 20°C to 150°C (10°C / min) (2) Holding at 150°C for 10 minutes (3) Cooling from 150°C to 0°C (10°C / min) (4) Holding at 0°C for 10 minutes (5) Heating from 0°C to 150°C (10°C / min) Analysis: In (5), the intersection point of the extension line of the baseline on the low temperature side and the tangent line drawn at the point where the slope of the stepwise change part of the glass transition becomes maximum was defined as the glass transition point.

[0093] (Synthesis Examples 1-3: Synthesis of amorphous polyester resin and crystalline polyester resin) Into a four-necked 3 L stainless steel flask equipped with a stirrer, a nitrogen gas inlet, and a thermometer, the raw materials shown in Table 1 were charged. After charging the raw materials, while removing the generated water, the temperature was raised to 240 °C over 6 hours under a nitrogen stream, and the reaction was carried out at 240 °C until the target acid value and molecular weight were obtained, to obtain amorphous polyester resin A-1 and crystalline polyester resins C-1 to C-2. Regarding the obtained amorphous polyester resin A-1 and crystalline polyester resins C-1 to C-2, the acid value, hydroxyl value, number average molecular weight, weight average molecular weight, and melting point were evaluated respectively. The results are shown in Table 1.

[0094]

Table 1

[0095] In Table 1, each abbreviation of the composition represents the following respectively. BPAEO: Bisphenol A ethylene oxide adduct BPAPO: Bisphenol A propylene oxide adduct 1,6HD: 1,6-Hexanediol DSA: Dodecenyl succinic anhydride TPA: Terephthalic acid DDDA: Dodecanedioic acid

[0096] (Examples 1-11 and Comparative Examples 1-8: Production of Toner) (Synthesis of Dispersion Resin) Into a four-necked 3 L stainless steel flask equipped with a stirrer, a nitrogen gas inlet, and a thermometer, 281.7 parts by mass of bisphenol A ethylene oxide adduct, 828.6 parts by mass of bisphenol A propylene oxide adduct, 400.6 parts by mass of terephthalic acid, 72.4 parts by mass of adipic acid, and 23.8 parts by mass of trimellitic anhydride were charged, and 0.8 parts by mass of titanium tetraisopropoxide was added as a catalyst. After charging the raw materials, the reaction was carried out at 240 °C for 7 hours under a nitrogen stream while removing the generated water, to obtain a dispersion resin.

[0097] (Preparation of Pigment Dispersion) 200 parts by mass of First Gen Blue TGR (β-type copper phthalocyanine pigment, C.I. Pigment Blue 15:3, manufactured by DIC Corporation) and 200 parts by mass of the dispersion resin were kneaded with a two-roll mill. The obtained kneaded product and 740 parts by mass of methyl ethyl ketone were charged into a ball mill and stirred for 6 hours, and the solid content was adjusted to 20% by mass with methyl ethyl ketone to obtain a pigment dispersion.

[0098] (Preparation of release agent dispersion) 200 parts by mass of carnauba wax No. 1 (melting point 83.1 °C, manufactured by Kato Yoko Co., Ltd., plant-based wax) and 200 parts by mass of the dispersion resin were kneaded with a pressure kneader. The obtained kneaded product and 740 parts by mass of methyl ethyl ketone were charged into a ball mill and stirred for 6 hours, and the solid content was adjusted to 20% by mass with methyl ethyl ketone to obtain a release agent dispersion.

[0099] (Preparation of wet kneading mill base) An amorphous polyester resin, a crystalline polyester resin, an additive, the pigment dispersion, and the release agent dispersion were mixed with a disper at the amounts shown in Table 2-3, and methyl ethyl ketone was added to the obtained mixture to adjust the solid content to 55% by mass, thereby obtaining mill bases MB-1 to MB-11 and mill bases MB'-1 to MB'-8.

[0100] (Manufacture of toner) To a 2L separable flask equipped with a max blend blade, 545.5 parts by mass of each of mill bases MB-1 to MB-11 and mill bases MB'-1 to MB'-8, and 23.8 parts by mass of 1N aqueous ammonia were added, and after sufficiently stirring at 350 rpm with a three-one motor, the temperature was adjusted to 30 °C, and 266 parts by mass of deionized water was added dropwise for phase inversion emulsification. After phase inversion emulsification, 333 parts by mass of deionized water was added to prepare a fine particle dispersion. Next, 4.1 parts by mass of polyoxyethylene polyoxypropylene glycol (Epane 450, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), a nonionic emulsifier, was added, the rotation speed was adjusted to 250 rpm while maintaining the temperature at 30 °C, 410 parts by mass of a 3% aqueous ammonium sulfate solution was added dropwise, and stirring was carried out for 5 minutes for coalescence to obtain a slurry. The obtained slurry was subjected to solid-liquid separation using a centrifuge, washed, and dried using a vacuum dryer to obtain toner particles. Using a Henschel mixer, 0.5 parts by mass of hydrophobic silica (H-2018, manufactured by Clariant Corporation) and 0.5 parts by mass of titanium oxide (JMT-150AO, manufactured by Teika Corporation) were externally added to 100 parts by mass of the toner particles to obtain toners T-1 to T-11 and toners T'-1 to T'-8, respectively. The following evaluations were performed on the obtained toner. The results are shown in Table 2-3.

[0101] (Crystallization ratio) The crystallization ratio of a mixture of an amorphous polyester resin, a crystalline polyester resin, and a crystallization accelerator contained in the toner was separately evaluated. Specifically, the melting heat quantity (J / g) of the mixture of the amorphous polyester resin, the crystalline polyester resin, and the crystallization accelerator, and that of the crystalline polyester resin were measured using a differential scanning calorimeter (DSC-220C, manufactured by Seiko Instruments Inc.). The melting heat quantity of the mixture was divided by the value obtained by multiplying the melting heat quantity of the crystalline polyester resin by the content ratio (mixture melting heat quantity / (crystalline polyester melting heat quantity × weight ratio in the mixture of the crystalline polyester)) to calculate the crystallization ratio of the mixture, and it was evaluated according to the following criteria. ◎: When it is 50% or more ○: When it is 40% or more and less than 50% △: When it is 30% or more and less than 40% ×: When it is less than 30%

[0102] The higher the crystallization ratio, the higher the sharp meltability of the mixture of the amorphous polyester resin, the crystalline polyester resin, and the crystallization accelerator, and an improvement in the low-temperature fixability of the toner can be expected.

[0103] (Low-temperature fixability) The copier was filled with toner, the set temperature of the heating roller was changed from 80°C to 140°C in 5°C increments, and solid printing was performed. A fastness test was conducted on the solid printed portion, the image density before and after the test was measured with a Macbeth densitometer (RD-918), and the temperature at which the ratio of the density value after peeling to the value before the test, expressed as a percentage, was 80% or more was defined as the fixing start temperature. The lower this temperature, the better the low-temperature fixability. The evaluation criteria for the low-temperature fixability of the toner were as follows. The fastness test was performed using a Kagaku-Shinkou friction fastness tester (load: 200 g, rubbing operation: 5 strokes). ◎: When the fixing start temperature is less than 110°C ○: When the fixing start temperature is 110°C or more and less than 115°C △: When the fixing start temperature is 115°C or more and less than 120°C ×: When the fixing start temperature is 120°C or more

[0104] (Heat resistance and storage stability) Toner left standing for 48 hours with a load of 66 g / cm² under an environment of 40°C and 50% RH was used as a sample. 400 g of this sample was vibrated for 30 seconds with an amplitude of 1 mm using a vibrating sieve apparatus equipped with a sieve having an opening of 45 μm. The ratio of the aggregates remaining on the sieve was evaluated according to the following criteria. The smaller the ratio of the aggregates, the better the heat resistance and storage stability. 2 ◎: When less than 10 mass% ◎: When less than 10 mass% ○: When 10 to less than 20 mass% △: When 20 to less than 30 mass% ×: When 30 mass% or more

[0105] (Charge amount and charge stability) Using an attracting blow-off type charge measuring device (210HS-2A, manufactured by Trek Japan Co., Ltd.), a mixture of 1.5 g of toner and 48.5 g of ferrite carrier (MF-1008, manufactured by Nippon Iron Powder Co., Ltd.) was mixed in a 50 ml plastic container for 1 minute, 10 minutes, 30 minutes, and 60 minutes respectively using a turboshaker mixer, and the charge amount of each of the resulting mixtures was measured using the said charge measuring device. The average value of the measured charge amounts was taken as the charge amount of the toner. The evaluation criteria for the charge amount were as follows. ◎: -45 μC / g or more ○: -40 μC / g or more and less than -45 μC / g △: -35 μC / g or more and less than -40 μC / g ×: -30 μC / g or more and less than -35 μC / g ××: less than -30 μC / g Also, regarding the charge amounts of the mixtures mixed for 10 minutes, 30 minutes, and 60 minutes, the difference between the maximum charge amount and the minimum charge amount was determined, and this value was used as the evaluation of charge stability. The smaller this value, the better the charge stability. The evaluation criteria for the charge stability were as follows. ◎: The difference between the maximum charge amount and the minimum charge amount is less than -3 μC / g ○: The difference between the maximum charge amount and the minimum charge amount is -3 μC / g or more and less than -6 μC / g △: The difference between the maximum charge amount and the minimum charge amount is -6 μC / g or more and less than -9 μC / g ×: The difference between the maximum charge amount and the minimum charge amount is -9 μC / g or more and less than -12 μC / g

[0106]

Table 2

[0107]

Table 3

[0108] In Table 2-3, additives CP-1 to CP-3 and CP'-2 to CP'-3 are compounds with the following structures. Additive CP'-1 is soybean oil (a mixture of linoleic acid, oleic acid, palmitic acid, linolenic acid, and stearic acid). Among the following compounds, additives CP-1 to CP-3 are all "compounds having two or more ester bonds and a cyclic structure".

[0109]

Chemical formula

[0110]

Chemical formula

[0111] From the results in Table 2-3, it can be seen that the low-temperature fixability is improved by using a crystallization accelerator with a specific structure.

Claims

1. A binder resin composition for toner containing an amorphous polyester resin, a crystalline polyester resin, and a crystallization accelerator, wherein the crystallization accelerator is a compound having two or more ester bonds and a cyclic structure.

2. The binder resin composition for toner according to claim 1, wherein the crystallization accelerator is an aliphatic ester compound having a cyclic ether and two or more ester bonds, or an aliphatic diester compound in which at least one end is blocked with an aromatic ring.

3. The binder resin composition for toner according to claim 1, wherein the crystallization accelerator is a compound represented by the following general formula (1-1) and / or a compound represented by the following general formula (1-2). 【化1】 (In the general formulas (1-1) and (1-2), L １ is an n1-valent aliphatic hydrocarbon group, R １ are each independently an alkyl group having 1 to 24 carbon atoms or an alkyl group having 2 to 24 carbon atoms and an epoxy ring, and R １ at least one of is an alkyl group having 2 to 24 carbon atoms and an epoxy ring; n1 is an integer in the range of 2 to 4, L ２１ , L ２２ and L ２３ is, independently of one another, a single bond, an alkylene group having 1 to 12 carbon atoms, or an alkyleneoxy group having 1 to 12 carbon atoms, R ２１ and R ２２ are each independently an aryl group having 6 to 18 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and at least one of R ２１ and R ２２ is an aryl group having 6 to 18 carbon atoms.)

4. The binder resin composition for toner according to claim 1, wherein the content of the crystalline polyester resin is in the range of 5 to 30% by mass of the total of the amorphous polyester resin, the crystalline polyester resin, and the crystallization accelerator.

5. The binder resin composition for toner according to claim 1, wherein the content of the crystallization accelerator is in the range of 0.5 to 15% by mass of the total of the amorphous polyester resin, the crystalline polyester resin, and the crystallization accelerator.

6. The binder resin composition for toner according to claim 1, wherein the crystalline polyester resin has a structure derived from an aliphatic monobasic acid having 8 to 32 carbon atoms.

7. An electrostatic charge image developing toner containing the binder resin composition for toner according to any one of claims 1 to 6.

8. An electrostatic charge image developer containing the electrostatic charge image developing toner according to claim 7 and a carrier.

Images