JP7522251B2 - Toner Binder - Google Patents

Description

The present invention relates to a toner binder.

In recent years, along with the promotion of miniaturization, speedup, higher image quality and higher reliability of electrophotographic apparatuses, there has been a strong demand for improving the low-temperature fixability of toners from the viewpoint of energy saving, ie, reducing energy consumption in the fixing process.
The toner binder has a large effect on the above-mentioned toner characteristics. Known examples of the toner binder include polystyrene resin, styrene-acrylic resin, polyester resin, epoxy resin, polyurethane resin, and polyamide resin. Recently, polyester resin has been attracting particular attention because it is easy to balance storage stability and fixability.
For example, a toner using a crystalline polyester resin with excellent melting properties and an amorphous resin has been proposed for the purpose of low-temperature fixing property (see Patent Document 1). Also, a toner composition containing a hybrid polyester of a crystalline polyester and an amorphous polyester has been proposed for the purpose of improving low-temperature fixing property and chargeability (see Patent Document 2).
However, when the particle size of the toner is reduced to meet the demand for even higher image quality, the dispersibility of the crystalline polyester resin in the toner using the above-mentioned crystalline polyester resin is not sufficient, and improvements in this respect are desired.

JP 2002-287426 A Patent No. 6485155

The present invention aims to provide a toner binder that has excellent dispersibility of crystalline polyester resin in amorphous polyester resin.

The present inventors have conducted extensive research and have arrived at the present invention.
That is, the present invention provides a toner binder containing a crystalline polyester resin (A), an amorphous polyester resin (B) and a graft polymer (C), in which the crystalline polyester resin (A) is a polyester resin obtained by reacting an alcohol component (x) and a carboxylic acid component (y) as raw materials, the alcohol component (x) contains an aliphatic diol (x1) having 2 to 36 carbon atoms, the content of (x1) in (x) being 20 to 80 mol % based on the total number of moles of (x), and the carboxylic acid component (y) is an aliphatic diol (x2) having 4 to 36 carbon atoms. the content of (y1) in (y) is 20 to 80 mol % based on the total number of moles of (y); the crystalline polyester resin (A) has an endothermic peak top temperature (Tm) of 50° C. to 85° C. as measured by a differential scanning calorimeter (DSC), and the half width of the endothermic peak of the crystalline polyester resin (A) is 7° C. or less; and the graft polymer (C) is a polymer having a side chain branched from a polyolefin containing ethylene and/or propylene as an essential constituent monomer.

The toner binder of the present invention has the effect of providing excellent dispersibility of crystalline polyester resin in amorphous polyester resin.

The present invention relates to a toner binder containing a crystalline polyester resin (A), an amorphous polyester resin (B), and a graft polymer (C), in which the crystalline polyester resin (A) is a polyester resin obtained by reacting an alcohol component (x) and a carboxylic acid component (y) as raw materials, the alcohol component (x) contains an aliphatic diol (x1) having 2 to 36 carbon atoms, the content of (x1) in (x) being 20 to 80 mol% based on the total number of moles of (x), and the carboxylic acid component (y) is an aliphatic dicarbohydrazide having 4 to 36 carbon atoms. The toner binder contains carboxylic acid (y1), the content of (y1) in (y) is 20 to 80 mol% based on the total number of moles of (y), the crystalline polyester resin (A) has an endothermic peak top temperature (Tm) of 50°C to 85°C measured by a differential scanning calorimeter (DSC), the half-width of the endothermic peak of the crystalline polyester resin (A) is 7°C or less, and the graft polymer (C) is a polymer having a side chain branched from a polyolefin having ethylene and/or propylene as essential constituent monomers.

The present invention is a toner binder containing a crystalline polyester resin (A), an amorphous polyester resin (B) and a graft polymer (C).
In the present invention, "crystalline" means that in differential scanning calorimetry (also referred to as DSC measurement), the DSC curve has a peak top temperature (Tm) of an endothermic peak.
The method for measuring the peak top temperature (Tm) of the endothermic peak will be described below.
The measurement is performed using a differential scanning calorimeter (e.g., DSC Q20, manufactured by TA Instruments, Inc.). The sample is first heated from 30° C. to 180° C. at 10° C./min, then cooled from 180° C. to 0° C. at 10° C./min, and then heated a second time from 0° C. to 180° C. at 10° C./min. The top temperature of the endothermic peak during the second heating process is taken as the peak top temperature (Tm) of the endothermic peak.

The crystalline polyester resin (A) in the present invention is a polyester resin obtained by reacting an alcohol component (x) and a carboxylic acid component (y) as raw materials, the alcohol component (x) contains an aliphatic diol (x1) having 2 to 36 carbon atoms, the content of (x1) in (x) is 20 to 80 mol% based on the total number of moles of (x), and the carboxylic acid component (y) contains an aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms, the content of (y1) in (y) is 20 to 80 mol% based on the total number of moles of (y). The alcohol component (x) and the carboxylic acid component (y) may be used alone or in combination of two or more kinds.

The alcohol component (x) of the crystalline polyester resin (A) in the present invention includes the essential component aliphatic diol (x1) having 2 to 36 carbon atoms, as well as diols other than the aliphatic diol (x1) having 2 to 36 carbon atoms and/or polyols having a valence of 3 or more, which will be described later. In addition, monoalcohols may be used as the alcohol component (x) if necessary.

Examples of aliphatic diols (x1) having 2 to 36 carbon atoms include linear aliphatic diols having 2 to 36 carbon atoms (ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,18-octadecanediol, 1,19-nonadecanediol, diol and 1,20-eicosanediol, etc.), branched aliphatic diols having 3 to 36 carbon atoms (propylene glycol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, etc.), and alicyclic diols having 4 to 36 carbon atoms (for example, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.).

Among the above aliphatic diols (x1) having 2 to 36 carbon atoms, linear aliphatic diols having 2 to 36 carbon atoms are preferred from the viewpoint of crystallinity.

Examples of diols other than the aliphatic diol (x1) having 2 to 36 carbon atoms include alkylene ether glycols having 4 to 36 carbon atoms (e.g., diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alkylene oxide adducts of the above alicyclic diols (preferably 1 to 30 moles added), alkylene oxide adducts of bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) (preferably 2 to 30 moles added), polylactone diols (poly ε-caprolactone diol, etc.), and polybutadiene diols.

In the alkylene oxide adducts of alicyclic diols or bisphenols, examples of the alkylene oxide (hereinafter, "alkylene oxide" may be abbreviated as AO) include ethylene oxide (hereinafter, "ethylene oxide" will be abbreviated as EO) adducts, propylene oxide (hereinafter, "propylene oxide" will be abbreviated as PO) adducts, and butylene oxide (hereinafter, "butylene oxide" will be abbreviated as BO) adducts.

Examples of polyols with a valence of three or more include alkane polyols and their intramolecular or intermolecular dehydration products (e.g., glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, polyglycerin, etc.), sugars and their derivatives (e.g., sucrose and methyl glucoside, etc.), alkylene oxide adducts of trisphenols (trisphenol PA, etc.) (the number of moles added is preferably 2 to 30), alkylene oxide adducts of novolac resins (including phenol novolac and cresol novolac, etc., with an average degree of polymerization of preferably 3 to 60) (the number of moles added is preferably 2 to 30), and acrylic polyols [copolymers of hydroxyethyl (meth)acrylate and other vinyl monomers, etc.].

Examples of monoalcohols include linear or branched alkyl alcohols having 1 to 30 carbon atoms (methanol, ethanol, isopropanol, 1-decanol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and lignoceryl alcohol, etc.).

As components other than the aliphatic diol (x1) having 2 to 36 carbon atoms, from the viewpoint of dispersibility, diols other than the aliphatic diol (x1) having 2 to 36 carbon atoms and monoalcohols are preferred, and alkylene oxide adducts of bisphenol A and linear alkyl alcohols having 1 to 30 carbon atoms are more preferred.

The carboxylic acid component (y) of the crystalline polyester resin (A) in the present invention includes, in addition to the essential component aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms, aromatic dicarboxylic acids and/or polycarboxylic acids having a valence of 3 or more, as well as anhydrides and lower alkyl (having 1 to 4 carbon atoms) esters (methyl esters, ethyl esters, isopropyl esters, etc.) of these acids, which will be described later. In addition, monocarboxylic acids may be used as the carboxylic acid component (y) if necessary.

Examples of the aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms include alkanedicarboxylic acids having 4 to 36 carbon atoms (alkanedicarboxylic acids having carboxyl groups at both ends of a chain-like saturated hydrocarbon group (adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,18-octadecanedicarboxylic acid, etc.), alkanedicarboxylic acids having a carboxyl group other than at the end of a chain-like saturated hydrocarbon group (decylsuccinic acid, etc.)), and alkenedicarboxylic acids having 4 to 36 carbon atoms (alkenylsuccinic acids such as dodecenylsuccinic acid, pentadecenylsuccinic acid, octadecenylsuccinic acid, maleic acid, fumaric acid, citraconic acid, etc.).

Among the above aliphatic dicarboxylic acids (y1) having 4 to 36 carbon atoms, alkanedicarboxylic acids having carboxyl groups at both ends of a chain saturated hydrocarbon group are preferred from the viewpoint of crystallinity.

The aromatic dicarboxylic acid is not particularly limited as long as it is a carboxylic acid having two carboxyl groups bonded to a conjugated unsaturated ring structure such as a benzene ring or a naphthalene ring, and examples thereof include aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, isophthalic acid, terephthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, etc.).

Examples of polycarboxylic acids with a valence of three or more include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), aliphatic tricarboxylic acids having 6 to 36 carbon atoms (such as hexanetricarboxylic acid), and vinyl polymers of unsaturated carboxylic acids [number average molecular weight (Mn): 450 to 10,000] (styrene/maleic acid copolymer, styrene/acrylic acid copolymer, styrene/fumaric acid copolymer, etc.).

Examples of monocarboxylic acids include aromatic monocarboxylic acids having 7 to 37 carbon atoms (including the carbonyl group carbon) (benzoic acid, toluic acid, 4-ethylbenzoic acid, 4-propylbenzoic acid, etc.), and aliphatic monocarboxylic acids having 2 to 50 carbon atoms (acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, behenic acid, (meth)acrylic acid ("(meth)acrylic" means acrylic or methacrylic), crotonic acid, isocrotonic acid, cinnamic acid, etc.).

As components other than the aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms, from the viewpoint of dispersibility, aromatic dicarboxylic acids and polycarboxylic acids having a valence of 3 or more are preferred, and aromatic dicarboxylic acids having 8 to 36 carbon atoms and aromatic polycarboxylic acids having 9 to 20 carbon atoms are more preferred.

The content of the aliphatic diol (x1) having 2 to 36 carbon atoms in the alcohol component (x) is 20 to 80 mol % based on the total number of moles of (x) from the viewpoint of crystallinity and dispersibility, and is preferably 40 to 60 mol %.

The content of the aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms in the carboxylic acid component (y) is 20 to 80 mol % based on the total number of moles of (y) from the viewpoint of crystallinity and dispersibility, and preferably 40 to 60 mol %.

The reaction ratio of the alcohol component (x) to the carboxylic acid component (y) is preferably 1/2 to 2/1, more preferably 1/1.3 to 1.5/1, and even more preferably 1/1.2 to 1.4/1, in terms of the molar ratio of hydroxyl groups to carboxyl groups {[OH]/[COOH]}.

In the present invention, the crystalline polyester resin (A) can be produced by polycondensation reaction, transesterification reaction, etc., but from the viewpoint of crystallinity, it is preferable to produce it by combining polycondensation reaction and transesterification reaction. For example, there is a method of producing it by transesterification reaction between the crystalline part (a1) obtained by polycondensation reaction and the amorphous part (a2).
The crystalline portion (a1) is a polyester having an endothermic peak top temperature (Tm) measured by a differential scanning calorimeter (DSC) and obtained by reacting an alcohol component and a carboxylic acid component as raw materials. The amorphous portion (a2) is a polyester having no endothermic peak top temperature (Tm) measured by a differential scanning calorimeter (DSC) and obtained by reacting an alcohol component and a carboxylic acid component as raw materials.

In the production of the crystalline polyester resin (A) of the present invention, when the crystalline polyester resin (A) is obtained by a transesterification reaction between the crystalline portion (a1) and the amorphous portion (a2), the reaction can be carried out in an inert gas (nitrogen gas, etc.) atmosphere at a reaction temperature of preferably 120 to 280°C, more preferably 130 to 250°C, and even more preferably 140 to 235°C. In order to ensure that the transesterification reaction is carried out, the reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.

In this case, an esterification catalyst can be used as necessary.
Examples of the esterification catalyst include tin-containing catalysts (e.g., dibutyltin oxide, etc.), antimony trioxide, titanium-containing catalysts [e.g., titanium alkoxide, potassium oxalate titanate, titanium terephthalate, titanium alkoxide terephthalate, catalysts described in JP-A-2006-243715 (titanium diisopropoxybistriethanolaminate, titanium dihydroxybistriethanolaminate, titanium monohydroxytriethanolaminate, titanyl bistriethanolaminate, and intramolecular polycondensates thereof, etc.), and catalysts described in JP-A-2007-11307 (titanium tributoxyterephthalate, titanium triisopropoxyterephthalate, titanium diisopropoxyditerephthalate, etc.)], zirconium-containing catalysts (e.g., zirconyl acetate, etc.), and zinc acetate.
Of the esterification catalysts, titanium-containing catalysts are preferred from the viewpoint of low-temperature fixability, and the catalysts described in JP-A-2006-243715 and JP-A-2007-11307 are more preferred.

The peak top temperature (Tm) of the endothermic peak of the crystalline polyester resin (A) in the present invention measured by a differential scanning calorimeter (DSC) is 50 to 85°C, preferably 60 to 80°C, and more preferably 70 to 80°C.
When Tm is 50° C. or higher, the crystallinity is good, and when Tm is 85° C. or lower, the dispersibility is good. Tm can be adjusted by the content and carbon number of the aliphatic diol (x1) having 2 to 36 carbon atoms and the content and carbon number of the aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms.
For example, as the content and carbon number of the aliphatic diol (x1) and the aliphatic dicarboxylic acid (y1) increase, the peak top temperature (Tm) becomes higher.
Furthermore, when the crystalline polyester resin (A) is a resin obtained by a transesterification reaction between a crystalline portion (a1) and an amorphous portion (a2), the crystallinity is easily maintained even when the contents and carbon numbers of the aliphatic diol (x1) and the aliphatic dicarboxylic acid (y1) are small, so that the peak top temperature (Tm) of the endothermic peak can be easily achieved.

The half-width of the endothermic peak showing the peak top temperature (Tm) of the crystalline polyester resin (A) in the present invention is 7° C. or less, preferably 6° C. or less, and particularly preferably 2 to 6° C. The half-width of the endothermic peak showing the peak top temperature (Tm) is the temperature width of the peak at half the height of the maximum peak height from the baseline of the endothermic peak based on the DSC curve obtained by measuring the peak top temperature (Tm) of the endothermic peak. The half-width of the endothermic peak can be adjusted by the content and carbon number of the aliphatic diol (x1) having 2 to 36 carbon atoms and the content and carbon number of the aliphatic dicarboxylic acid (y1) having 4 to 36 carbon atoms, and reaction conditions such as polycondensation reaction and ester exchange reaction.
For example, as the content and carbon number of the aliphatic diol (x1) and the aliphatic dicarboxylic acid (y1) increase, the half-width of the endothermic peak decreases. In addition, if the crystalline polyester resin (A) is a resin obtained by transesterification between the crystalline portion (a1) and the amorphous portion (a2), the crystallinity is easily maintained even when the content and carbon number of the aliphatic diol (x1) and the aliphatic dicarboxylic acid (y1) are small, so that the half-width of the endothermic peak can be easily achieved.
For example, if the crystalline polyester resin (A) is a resin obtained by a transesterification reaction between a crystalline portion (a1) and an amorphous portion (a2), and the weight ratio (a1/a2) of the crystalline portion (a1) to the amorphous portion (a2) is 20/80 to 70/30, the above half width can be easily achieved.

From the viewpoint of crystallinity, it is preferable that the endothermic amount based on the endothermic peak of the crystalline polyester resin (A) measured by a differential scanning calorimeter (DSC) is 20 to 90 J/g.

From the viewpoint of crystallinity, the acid value of the crystalline polyester resin (A) is preferably 0 to 30 mgKOH/g, and more preferably 0 to 10 mgKOH/g.

From the viewpoint of crystallinity, the hydroxyl value of the crystalline polyester resin (A) is preferably 0 to 100 mgKOH/g, and more preferably 20 to 50 mgKOH/g.

The number average molecular weight (hereinafter sometimes abbreviated as Mn) of the crystalline polyester resin (A) is preferably 1,000 to 1,000,000, more preferably 3,000 to 10,000, from the viewpoint of crystallinity.

The weight average molecular weight (hereinafter sometimes abbreviated as Mw) of the crystalline polyester resin (A) is preferably 2,000 to 2,000,000, more preferably 6,000 to 20,000, from the viewpoint of crystallinity.

The amorphous polyester resin (B) in the present invention is a polyester resin obtained by reacting an alcohol component (X) and a dicarboxylic acid component (Y) as raw materials, and it is preferable from the viewpoint of chargeability and storage stability that the alcohol component (X) contains an alkylene oxide adduct (X1) of bisphenol A. The alcohol component (X) and the carboxylic acid component (Y) may be used alone or in combination of two or more kinds.

The alcohol component (X) of the amorphous polyester resin (B) in the present invention may be an alkylene oxide adduct (X1) of bisphenol A, as well as a diol other than (X1) described below and/or a polyol having a valence of three or more. In addition, a monoalcohol may be used as the alcohol component (X) if necessary.

The alkylene oxide adduct of bisphenol A (X1) is a compound obtained by adding an alkylene oxide to bisphenol A, and examples thereof include an EO adduct of bisphenol A, a PO adduct of bisphenol A, and a BO adduct of bisphenol A.

Among the alkylene oxide adducts of bisphenol A (X1) described above, EO adducts of bisphenol A and PO adducts of bisphenol A are preferred from the viewpoints of chargeability and storage stability.

From the viewpoints of chargeability and storage stability, the number of moles of alkylene oxide added in the alkylene oxide adduct of bisphenol A (X1) is preferably 2 to 30, more preferably 2 to 10, and even more preferably 2 to 5.

Diols other than the alkylene oxide adduct of bisphenol A (X1) include linear aliphatic diols having 2 to 36 carbon atoms (ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,18-octadecanediol, 1,19-nonadecanediol, and 1,20-eicosanediol, etc.), branched aliphatic diols having 3 to 36 carbon atoms (propylene glycol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, etc.), alicyclic diols having 4 to 36 carbon atoms (e.g., 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), alkylene ether glycols having 4 to 36 carbon atoms (e.g., diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alkylene oxide (EO, PO, BO, etc.) adducts of the above alicyclic diols (preferably 1 to 30 moles added), alkylene oxide (EO, PO, BO, etc.) adducts of bisphenols (bisphenol F, bisphenol S, etc.) (preferably 2 to 30 moles added), polylactone diols (poly ε-caprolactone diol, etc.), and polybutadiene diols.

As the polyol having a valence of three or more, the same ones as those exemplified for the crystalline polyester resin (A) can be used.

As the monoalcohol, the same ones as those exemplified for the crystalline polyester resin (A) can be used.

When the alcohol component (X) contains a component other than the alkylene oxide adduct of bisphenol A (X1), from the viewpoint of low-temperature fixability, a diol is preferred, and a linear aliphatic diol having 2 to 36 carbon atoms and a branched aliphatic diol having 3 to 36 carbon atoms are more preferred.

The carboxylic acid component (Y) of the amorphous polyester resin (B) in the present invention can be the same as the carboxylic acid component (y) exemplified for the crystalline polyester resin (A). Preferred carboxylic acid components (Y) are aromatic dicarboxylic acids having 8 to 36 carbon atoms, alkane dicarboxylic acids having 4 to 36 carbon atoms, and aromatic polycarboxylic acids having 9 to 20 carbon atoms.

From the viewpoints of electrostatic chargeability and storage stability, the content of the alkylene oxide adduct (X1) of bisphenol A in the alcohol component (X) is preferably 90 to 100 mol % based on the total number of moles of the alcohol component (X), which is a constituent of the polyester resin, more preferably 95 to 100 mol %, and even more preferably 100 mol %.

From the viewpoints of chargeability and storage stability, the content of aromatic dicarboxylic acid in the carboxylic acid component (Y) is preferably 70 to 100 mol % based on the total number of moles of the carboxylic acid component (Y), which is a constituent of the polyester resin.

The reaction ratio of the alcohol component (X) to the carboxylic acid component (Y) is preferably 1/2 to 2/1, more preferably 1/1.3 to 1.5/1, and even more preferably 1/1.2 to 1.4/1, in terms of the molar ratio of hydroxyl groups to carboxyl groups {[OH]/[COOH]}.

In the present invention, the amorphous polyester resin (B) can be produced in the same manner as known polyester production methods. For example, the components including the alcohol component (X) and the carboxylic acid component (Y) can be reacted in an inert gas (nitrogen gas, etc.) atmosphere at a reaction temperature of preferably 150 to 280°C, more preferably 160 to 250°C, and even more preferably 170 to 235°C. The reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours, from the viewpoint of ensuring that the polycondensation reaction is carried out. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.

In this case, an esterification catalyst can be used if necessary. The esterification catalyst can be the same as the esterification catalyst exemplified for the crystalline polyester resin (A), and the preferred catalysts are also the same.

The glass transition temperature (hereinafter abbreviated as Tg) of the amorphous polyester resin (B) is preferably 20 to 90°C, and more preferably 40 to 80°C. If it is 20°C or higher, it has excellent heat resistance storage properties, and if it is 90°C or lower, there is little inhibition of low-temperature fixability.

From the viewpoints of electrostatic chargeability and heat-resistant storage stability, the acid value of the amorphous polyester resin (B) is preferably 0 to 75 mgKOH/g, and more preferably 8 to 23 mgKOH/g.

The hydroxyl value of the amorphous polyester resin (B) is preferably 0 to 120 mgKOH/g, more preferably 1 to 55 mgKOH/g, from the viewpoints of electrostatic chargeability and heat-resistant storage stability.

The number average molecular weight (hereinafter sometimes abbreviated as Mn) of the amorphous polyester resin (B) is preferably 1,000 to 100,000, more preferably 2,500 to 65,000, from the viewpoints of heat-resistant storage stability and low-temperature fixability.

The weight average molecular weight (hereinafter sometimes abbreviated as Mw) of the amorphous polyester resin (B) is preferably 2,000 to 200,000, more preferably 5,000 to 130,000, from the viewpoints of heat-resistant storage stability and low-temperature fixability.

The 1/2 drop temperature of the amorphous polyester resin (B) is preferably 80 to 170°C from the viewpoint of heat resistance storage stability and low-temperature fixability, and more preferably 97 to 150°C.

Two or more types of amorphous polyester resin (B) with different 1/2 drop temperatures may be used in combination. From the viewpoint of low-temperature fixability, a combination of a resin with a 1/2 drop temperature of 80°C or more and less than 110°C and a resin with a 1/2 drop temperature of 110°C or more and 170°C or less is preferred, and a combination of a resin with a 1/2 drop temperature of 85°C to 105°C and a resin with a 1/2 drop temperature of 115°C to 160°C is more preferred.

The graft polymer (C) in the present invention is a polymer having a side chain branched from a polyolefin having ethylene and/or propylene as essential constituent monomers. Examples of polyolefins having ethylene and/or propylene as essential constituent monomers include polyethylene and polypropylene.

The side chain branched from the polyolefin is a polymer having a monomer having a vinyl group as a constituent monomer. The monomer having a vinyl group is not particularly limited as long as it forms a side chain branched from the polyolefin, and can be appropriately selected from known monomers depending on the purpose, and examples thereof include the following (1) to (10).
(1) Vinyl Hydrocarbons Examples of the vinyl hydrocarbons include (1-1) aliphatic vinyl hydrocarbons, (1-2) alicyclic vinyl hydrocarbons, and (1-3) aromatic vinyl hydrocarbons.
(1-1) Aliphatic Vinyl Hydrocarbons Examples of the aliphatic vinyl hydrocarbons include alkenes and alkadienes.
Specific examples of alkenes include propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, and α-olefins other than those mentioned above.
Specific examples of alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-heptadiene, and 1,7-octadiene.
(1-2) Alicyclic Vinyl Hydrocarbons Examples of alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, and specific examples thereof include cyclohexene, (di)cyclopentadiene, vinylcyclohexene, ethylidenebicycloheptene, and terpenes (pinene, limonene, indene, etc.).
(1-3) Aromatic Vinyl Hydrocarbons Examples of aromatic vinyl hydrocarbons include styrene and its hydrocarbyl (alkyl, cycloalkyl, aralkyl and/or alkenyl) substituted products, and specific examples thereof include α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, benzylstyrene, crotylbenzene, divinylbenzene, divinyltoluene, divinylxylene, trivinylbenzene, and vinylnaphthalene.

(2) Carboxyl Group-Containing Vinyl Monomer and Salts Thereof Examples of the carboxyl group-containing vinyl monomer and salts thereof include unsaturated monocarboxylic acids (salts), unsaturated dicarboxylic acids (salts), and anhydrides thereof, and monoalkyl (C1-24) esters thereof, or salts thereof, each having 3 to 30 carbon atoms.
Specific examples thereof include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, (anhydride) maleic acid, maleic acid monoalkyl esters, fumaric acid, fumaric acid monoalkyl esters, crotonic acid, itaconic acid, itaconic acid monoalkyl esters, itaconic acid glycol monoether, citraconic acid, citraconic acid monoalkyl esters, and cinnamic acid, and metal salts thereof.

In the present invention, the term "(salt)" refers to a salt of a compound.
For example, an unsaturated monocarboxylic acid (salt) having 3 to 30 carbon atoms means an unsaturated monocarboxylic acid or a salt thereof.

(3) Sulfone Group-Containing Vinyl Monomers, Vinyl Sulfate Monoesters, and Salts Thereof Examples of sulfone group-containing vinyl monomers, vinyl sulfate monoesters, and salts thereof include C2-14 alkene sulfonic acids (salts), styrene sulfonic acid (salts), C2-24 alkyl derivatives of styrene sulfonic acid (salts), sulfo(hydroxy)alkyl-(meth)acrylates (salts), sulfo(hydroxy)alkyl-(meth)acrylamides (salts), alkylarylsulfosuccinic acids, and sulfates of polyoxyalkylene mono(meth)acrylates.
Specifically, vinyl sulfonic acid, (meth)allyl sulfonic acid, methyl vinyl sulfonic acid, styrene sulfonic acid, α-methyl styrene sulfonic acid, sulfopropyl (meth)acrylate, 2-hydroxy-3-(meth)acryloxypropyl sulfonic acid, 2-(meth)acryloylamino-2,2-dimethylethanesulfonic acid, 2-(meth)acryloyloxyethanesulfonic acid, 3-(meth)acryloyloxy-2-hydroxypropanesulfonic acid, 2-(meth)acryla amido-2-methylpropanesulfonic acid, 3-(meth)acrylamide-2-hydroxypropanesulfonic acid, alkyl (having 3 to 18 carbon atoms) allylsulfosuccinic acid, sulfate esters of poly(n=2 to 30)oxyalkylene (ethylene, propylene, butylene: may be single, random or block) mono(meth)acrylates [poly(n=5 to 15)oxypropylene monomethacrylate sulfate ester, etc.], and polyoxyethylene polycyclic phenyl ether sulfate esters.

(4) Phosphate-containing vinyl monomers and their salts:
Examples of the phosphoric acid group-containing vinyl monomer and its salt include (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphoric acid monoester (salt) and (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphonic acid (salt).
Specific examples include 2-hydroxyethyl (meth)acryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate, and 2-acryloyloxyethyl phosphonic acid.

Examples of the salts of (2) to (4) above include alkali metal salts (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), ammonium salts, amine salts, and quaternary ammonium salts.

(5) Hydroxyl Group-Containing Vinyl Monomers Examples of hydroxyl group-containing vinyl monomers include hydroxystyrene, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethyl propenyl ether, and sucrose allyl ether.

(6) Nitrogen-Containing Vinyl Monomers Examples of the nitrogen-containing vinyl monomers include (6-1) amino group-containing vinyl monomers, (6-2) amide group-containing vinyl monomers, (6-3) nitrile group-containing vinyl monomers, (6-4) quaternary ammonium cation group-containing vinyl monomers, and (6-5) nitro group-containing vinyl monomers.
(6-1) Examples of amino group-containing vinyl monomers include aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, t-butylaminoethyl methacrylate, N-aminoethyl (meth)acrylamide, (meth)allylamine, morpholinoethyl (meth)acrylate, 4-vinylpyridine, 2-vinylpyridine, crotylamine, N,N-dimethylaminostyrene, methyl α-acetaminoacrylate, vinylimidazole, N-vinylpyrrole, N-vinylthiopyrrolidone, N-arylphenylenediamine, aminocarbazole, aminothiazole, aminoindole, aminopyrrole, aminoimidazole, aminomercaptothiazole, and salts thereof.
(6-2) Examples of amide group-containing vinyl monomers include (meth)acrylamide, N-methyl(meth)acrylamide, N-butylacrylamide, diacetone acrylamide, N-methylol(meth)acrylamide, N,N'-methylene-bis(meth)acrylamide, cinnamic acid amide, N,N-dimethylacrylamide, N,N-dibenzyl acrylamide, methacrylformamide, N-methyl-N-vinylacetamide, and N-vinylpyrrolidone.
(6-3) Examples of nitrile group-containing vinyl monomers include (meth)acrylonitrile, cyanostyrene, and cyanoacrylate.
(6-4) Examples of the quaternary ammonium cation group-containing vinyl monomer include quaternized products of tertiary amine group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and diallylamine (which are quaternized with a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, or dimethyl carbonate).
(6-5) Nitro group-containing vinyl monomers include nitrostyrene and the like.

(7) Epoxy Group-Containing Vinyl Monomers Examples of epoxy group-containing vinyl monomers include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenylpropylene oxide.

(8) Halogen-Containing Vinyl Monomers Examples of halogen-containing vinyl monomers include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluoroethylene, fluoroacrylate, tetrafluorostyrene, and chloroprene.

(9) Alkyl esters of (meth)acrylic acid, vinyl esters, vinyl (thio) ethers, vinyl ketones (9-1) Examples of alkyl esters of (meth)acrylic acid include alkyl (meth)acrylates having an alkyl group having 1 to 50 carbon atoms [methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, etc.)].
(9-2) Examples of vinyl esters include vinyl butyrate, vinyl propionate, and vinyl butyrate.
(9-3) Examples of vinyl (thio)ethers include vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl butyl ether, vinyl 2-ethylhexyl ether, vinyl phenyl ether, vinyl 2-methoxyethyl ether, methoxybutadiene, vinyl 2-butoxyethyl ether, 3,4-dihydro-1,2-pyran, 2-butoxy-2'-vinyloxydiethyl ether, vinyl 2-ethylmercaptoethyl ether, acetoxystyrene, and phenoxystyrene.
(9-4) Examples of vinyl ketones include vinyl methyl ketone, vinyl ethyl ketone, and vinyl phenyl ketone.

(10) Other Vinyl Monomers Examples of other vinyl monomers include isocyanatoethyl (meth)acrylate and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

In the synthesis of the graft polymer (C), one of the vinyl monomers (1) to (10) above may be used alone or in combination of two or more. From the viewpoint of dispersibility, vinyl hydrocarbons, carboxyl group-containing vinyl monomers and their salts, nitrogen-containing vinyl monomers, and alkyl esters of (meth)acrylic acid are preferred, and aromatic vinyl hydrocarbons, unsaturated monocarboxylic acids (salts) having 3 to 30 carbon atoms, nitrile group-containing vinyl monomers, and alkyl (meth)acrylates having an alkyl group having 1 to 50 carbon atoms are more preferred, and styrene, acrylic acid, acrylonitrile, methyl methacrylate, and n-butyl acrylate are even more preferred.

The average value based on the molar fraction of the SP value (solubility parameter) of the monomer constituting the side chain branched from the polyolefin is preferably 10.3 to 12.3 (cal/cm ³ ) ^1/2 . More preferably, it is 10.5 to 11.8 (cal/cm ³ ) ^1/2 . If the average value based on the molar fraction of the SP value is 10.3 to 12.3, the graft polymer (C) has an appropriate polarity, and the dispersibility of the release agent and the crystalline polyester resin (A) in the toner is good. The SP value in the present invention can be calculated by the method by Fedors [Polym. Eng. Sci. 14(2)152, (1974)].

From the viewpoint of dispersibility, the weight ratio of the polyolefin in the graft polymer (C) is preferably 5 to 15% by weight based on the weight of (C). If it is 5% by weight or more, the dispersibility of the release agent and the crystalline polyester resin (A) is excellent, and if it is 15% by weight or less, there is little inhibition of low-temperature fixability.

The graft polymer (C) can be produced, for example, by dissolving or dispersing polyolefin in a solvent such as toluene or xylene, heating to 100°C to 200°C, then adding dropwise a mixture of monomers having vinyl groups together with a peroxide initiator (benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxide benzoate, etc.) to polymerize the mixture, and then distilling off the solvent.

The acid value of the graft polymer (C) is preferably 80 mgKOH/g or less, more preferably 63 mgKOH/g or less, and even more preferably 0.5 mgKOH/g or less. If the acid value is 80 mgKOH/g or less, the graft polymer (C) becomes hydrophobic and has excellent heat resistance and storage stability.

The number average molecular weight (hereinafter abbreviated as Mn) of the graft polymer (C) is preferably 1000 to 4000, and more preferably 1500 to 3000. If it is 1000 or more, it has excellent heat resistance storage properties, and if it is 4000 or less, there is little inhibition of low-temperature fixability.

The weight average molecular weight (hereinafter abbreviated as Mw) of the graft polymer (C) is preferably 8,000 to 40,000, and more preferably 8,000 to 39,400. If it is 8,000 or more, it has excellent heat resistance storage properties, and if it is 40,000 or less, there is little inhibition of low-temperature fixability.

The 1/2 drop temperature of the graft polymer (C) is preferably 90 to 140°C, more preferably 110 to 130°C.

From the viewpoint of low-temperature fixing property and fixing strength, the weight ratio of the crystalline polyester resin (A) in the toner binder of the present invention is preferably 5 to 50% by weight.

From the viewpoint of heat-resistant storage stability, the weight ratio of the amorphous polyester resin (B) in the toner binder of the present invention is preferably 47 to 92% by weight.

From the viewpoint of dispersibility, the weight ratio of the graft polymer (C) in the toner binder of the present invention is preferably 3 to 15% by weight.

From the viewpoints of low-temperature fixability and storage stability, the weight ratio (A/B) of the crystalline polyester resin (A) to the amorphous polyester resin (B) in the toner binder of the present invention is preferably 10/90 to 40/60.

Next, a method for producing the toner binder of the present invention will be described.
The method for producing the toner binder is not particularly limited as long as the crystalline polyester resin (A), the amorphous polyester resin (B) and the graft polymer (C) are uniformly mixed, and known mixing methods include, for example, powder mixing, melt mixing, solvent mixing, etc. The crystalline polyester resin (A), the amorphous polyester resin (B) and the graft polymer (C) may be mixed together with other necessary toner raw materials when producing the toner.

Examples of a mixer for powder mixing include a Henschel mixer, a Nauta mixer, and a Banbury mixer, with a Henschel mixer being preferred.
Examples of mixing devices for melt mixing include batch mixing devices such as reaction tanks and continuous mixing devices. Continuous mixing devices are preferred for uniform mixing in a short time at an appropriate temperature. Examples of continuous mixing devices include static mixers, extruders, continuous kneaders, and three-roll machines.
Examples of the solvent mixing method include a method in which the crystalline polyester resin (A), the amorphous polyester resin (B), and the graft polymer (C) are dissolved or dispersed in an organic solvent (ethyl acetate, THF, acetone, etc.), homogenized, then the solvent is removed and pulverized; and a method in which the crystalline polyester resin (A), the amorphous polyester resin (B), and the graft polymer (C) are dissolved or dispersed in an organic solvent (ethyl acetate, THF, acetone, etc.), dispersed in water, then granulated and the solvent is removed.

The toner binder obtained by the above-mentioned production method may be used to obtain resin particles for toner.
The content of the toner binder in the resin particles is preferably 30 to 97% by weight, more preferably 42 to 96% by weight, and further preferably 50 to 95% by weight, based on the weight of the resin particles.

The resin particles can be mixed with various known additives such as colorants, release agents, charge control agents, and fluidizing agents, if necessary.

The colorant preferably contains at least one selected from the group consisting of a black colorant, a blue colorant, a red colorant and a yellow colorant. As the colorant, any dye, pigment or the like that is used as a toner colorant can be used.
Specific examples thereof include carbon black, iron black, Sudan Black SM, Fast Yellow G, Benzidine Yellow, Solvent Yellow (21, 77, 114, etc.), Pigment Yellow (12, 14, 17, 83, etc.), India Fast Orange, Irgasin Red, Paranitoaniline Red, Toluidine Red, Solvent Red (17, 49, 128, 5, 13, 22, 48.2, etc.), Disperse Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Solvent Blue (25, 94, 60, 15.3, etc.), Pigment Blue, Brilliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orasol Brown B, and Oil Pink OP. If necessary, magnetic powder (powders of ferromagnetic metals such as iron, cobalt and nickel, and compounds such as magnetite, hematite and ferrite) may be contained to function as a colorant.
The content of the colorant is preferably 1 to 40 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the toner binder of the present invention. When a magnetic powder is used, the content of the magnetic powder is preferably 20 to 150 parts by weight, more preferably 30 to 120 parts by weight, based on 100 parts by weight of the toner binder.

Examples of the release agent include natural waxes (beeswax, carnauba wax, montan wax, etc.), petroleum waxes (paraffin wax, microcrystalline wax, petrolatum, etc.), synthetic waxes (Fischer-Tropsch wax, polyethylene wax, polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax, etc.), and synthetic ester waxes (fatty acid esters synthesized from fatty acids having 10 to 30 carbon atoms and alcohols having 10 to 30 carbon atoms, etc.), and it is preferable to contain one or more types selected from the group consisting of these release agents. The content of the release agent is preferably 0 to 30% by weight, more preferably 0.5 to 20% by weight, and even more preferably 1 to 10% by weight, based on 100 parts by weight of the toner binder of the present invention in total.

The charge control agent may be either a positively charged charge control agent or a negatively charged charge control agent, and examples thereof include nigrosine dyes, triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salts, polyamine resins, imidazole derivatives, polymers containing a quaternary ammonium base, metal-containing azo dyes, copper phthalocyanine dyes, metal salicylic acid salts, boron complexes of benzilic acid, polymers containing sulfonic acid groups, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers. The content of the charge control agent may be 0 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 0.5 to 7.5% by weight, based on 100 parts by weight of the total of the toner binder of the present invention.

Examples of the fluidizing agent include silica, titania, alumina, fatty acid metal salts, silicone resin particles, and fluororesin particles, and two or more of them may be used in combination. From the viewpoint of the chargeability of the toner, silica is preferred. From the viewpoint of the transferability of the toner, the silica is preferably hydrophobic. The content of the fluidizing agent may be 0 to 10% by weight, preferably 0 to 5% by weight, and more preferably 0.1 to 4% by weight, based on 100 parts by weight of the total of the toner binder of the present invention.

The total weight of additives such as colorants, release agents, charge control agents, and flow agents may be 3 to 70% by weight, preferably 4 to 58% by weight, and more preferably 5 to 50% by weight, based on the weight of the resin particles.

The volume average particle size (D50) of the resin particles is preferably 1 to 15 μm, more preferably 2 to 10 μm, and particularly preferably 3 to 7 μm. By keeping it within the above range, low-temperature fixability is improved.

There are no particular limitations on the method for producing the resin particles, and they may be obtained by a known kneading and grinding method, a suspension polymerization method described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842, an emulsion polymerization method represented by a soap-free polymerization method in which a toner is produced by directly polymerizing a monomer in the presence of a water-soluble polymerization initiator that is soluble in the monomer, an interfacial polymerization method such as a microcapsule manufacturing method, an in-site polymerization method, a coacervation method, an emulsion aggregation method in which at least one type of fine particles are aggregated to obtain a desired particle size as disclosed in JP-A-62-106473 and JP-A-63-186253, a dispersion polymerization method characterized by monodispersion, a dissolution suspension method in which the necessary resins are dissolved in a non-water-soluble organic solvent and then turned into resin particles in water, or an ester elongation polymerization method, or a method in which the resins are dispersed in carbon dioxide in a supercritical state.

When resin particles are used as a toner, they are mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite coated with a resin (acrylic resin, silicone resin, etc.) as necessary, and used as a developer for an electric latent image. When carrier particles are used, the weight ratio of the toner to the carrier particles is preferably 1/99 to 99/1. Alternatively, an electric latent image can be formed by rubbing against a member such as a charging blade instead of the carrier particles.
The toner does not necessarily have to contain carrier particles.

The toner is fixed to a support (paper, polyester film, etc.) by a copier, printer, etc. to form a recording material. The method of fixing to the support can be a known hot roll fixing method or flash fixing method, etc.

The toner is used to develop electrostatic images or magnetic latent images in electrophotography, electrostatic recording, electrostatic printing, etc. More specifically, it is used to develop electrostatic images or magnetic latent images that are particularly suitable for full color.

The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited to these. In the following, "parts" refers to parts by weight unless otherwise specified.

The physical properties of the crystalline polyester resin, amorphous polyester resin, graft polymer, toner, etc. were measured using the following methods.

<Peak Top Temperature of Endothermic Peak of Crystalline Polyester Resin>
The measurement was performed using a differential scanning calorimeter {e.g., "DSCQ20" [manufactured by TA Instruments, Inc.]}. The crystalline polyester resin was heated for the first time from 30°C to 180°C at 10°C/min, then cooled from 180°C to 0°C at 10°C/min, and then heated for the second time from 0°C to 180°C at 10°C/min. The temperature showing the top of the endothermic peak during the second heating process was determined as the peak top temperature of the endothermic peak of the crystalline polyester resin.

<Amount of heat absorbed at endothermic peak of crystalline polyester resin>
In the DSC curve during the second heating process observed under the same measurement conditions as in the measurement of the peak top temperature of the endothermic peak, a straight line was drawn connecting the point closest to the peak on the baseline below the endothermic peak endothermic onset temperature (T0) and the point closest to the peak on the baseline above the endothermic peak end point temperature, thereby calculating the amount of endotherm at the endothermic peak having the peak top temperature of the endothermic peak.

<Half-width of endothermic peak of crystalline polyester resin>
The temperature width of the peak at half the height of the maximum height of the peak from the baseline of the endothermic peak was defined as the half-width of the endothermic peak.

<Weight average molecular weight (Mw)>
The weight average molecular weight (Mw) was measured by dissolving a sample in tetrahydrofuran (THF) and filtering off the insoluble matter using a glass filter to obtain a sample solution, and measuring the molecular weight under the following conditions.
Equipment: Tosoh Corporation HLC-8120
Column: TSK GEL GMH6 x 2 (Tosoh Corporation)
Measurement temperature: 40°C
Sample solution: 0.25% by weight THF solution Injection amount: 100 μl
Detector: Refractive index detector Reference material: 12 standard polystyrenes (TSKstandard POLYSTYRENE) manufactured by Tosoh Corporation (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000) 355,000 1,090,000 2,890,000)

<Acid value and hydroxyl value>
The measurement was performed according to the method specified in JIS K0070, except that the measurement solvent for the acid value was a mixed solvent of acetone, methanol, and toluene (weight ratio of acetone:methanol:toluene=12.5:12.5:75), and the measurement solvent for the hydroxyl value was THF.

<1/2 drop in temperature>
Using a constant test force extrusion-type capillary rheometer flow tester (Shimadzu Corporation, CFT-500D), 1 g of a measurement sample was heated at a temperature increase rate of 6° C./min while applying a load of 1.96 MPa with a plunger and extruding the sample from a nozzle having a diameter of 1 mm and a length of 1 mm. A graph of "plunger drop amount (flow value)" versus "temperature" was then drawn, and the temperature corresponding to 1/2 of the maximum value of the plunger drop amount was read from the graph. This value (the temperature at which half of the measurement sample had flowed out) was defined as the 1/2 drop temperature.

<Method of measuring glass transition temperature (Tg)>
The measurement was performed using a differential scanning calorimeter (DSC Q20, manufactured by TA Instruments) according to the method (DSC method) specified in ASTM D3418-82 under the following conditions.
(1) Heat from 30°C to 150°C at 20°C/min. (2) Hold at 150°C for 10 minutes. (3) Cool to -35°C at 20°C/min. (4) Hold at -35°C for 10 minutes. (5) Heat to 150°C at 20°C/min. (6) The differential scanning calorimetry curve measured during (5) was analyzed to determine the glass transition temperature.

<Toner volume average particle size (D50) (μm), number average particle size (μm), particle size distribution (volume average particle size/number average particle size)>
The measurement was carried out using a Coulter counter [product name: Multisizer III (manufactured by Beckman Coulter, Inc.)].
First, 0.1 to 5 mL of a surfactant (alkylbenzene sulfonate) was added as a dispersant to 100 to 150 mL of ISOTON-II (manufactured by Beckman Coulter), which is an aqueous electrolyte solution. The electrolyte solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of toner particles were measured using the measuring device with a 50 μm aperture to obtain a volume distribution. From the distribution obtained, the volume average particle diameter (D50) (μm), number average particle diameter (μm), and particle size distribution (volume average particle diameter/number average particle diameter) of the toner were obtained. .

<Production Example 1> [Synthesis of Crystalline Polyester Resin (A-1)]
<Synthesis of Crystalline Part (a1)>
In a reaction vessel equipped with a cooling tube, a heating/cooling device, a thermometer, a stirrer, and a nitrogen inlet tube, 231 parts (50 mol%) of 1,12-dodecanediol, 259 parts (58 mol%) of dodecanedioic acid, 10 parts (1 mol%) of behenyl alcohol, and 1.5 parts of titanium dihydroxybis(triethanolamine) as a condensation catalyst were placed, and reacted for 8 hours under a nitrogen stream at 170°C while distilling off the water produced. The temperature was then gradually raised to 220°C, and the reaction was continued for 4 hours under a nitrogen stream while distilling off the water produced, and the reaction was continued under a reduced pressure of 0.5 to 2.5 kPa, and the resin was taken out when the acid value reached 1 mgKOH/g. The resin taken out was cooled to room temperature, pulverized, and granulated to obtain a crystal portion (a1). The weight average molecular weight (Mw) of the crystalline portion (a1) was 39,000, the peak top temperature (Tm) of the endothermic peak was 84° C., the endothermic amount at the endothermic peak was 116 J/g, the acid value was 1 mg KOH/g, and the hydroxyl value was 6 mg KOH/g.

<Synthesis of non-crystalline portion (a2)>
In another reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 153 parts (19 mol%) of bisphenol A·PO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-2P"), 209 parts (29 mol%) of bisphenol A·EO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BPE-20"), 132 parts (41 mol%) of terephthalic acid, and 3.0 parts of titanium dihydroxybis(triethanol aminate) as a condensation catalyst were placed, and the temperature was raised to 230°C under a reduced pressure of 0.5 to 2.5 kPa while distilling off the water produced, and the reaction was continued until the acid value was less than 2 mgKOH/g. Next, the mixture was cooled to 180°C, and 6 parts (2 mol%) of trimellitic anhydride was added, and the mixture was reacted under normal pressure for 1 hour and then taken out. The taken-out resin was cooled to room temperature, and then pulverized to form particles, to obtain the amorphous portion (a2). The non-crystalline portion (a2) had a 1/2 drop temperature of 97° C., a glass transition temperature (Tg) of 58° C., an acid value of 8 mg KOH/g, a hydroxyl value of 55 mg KOH/g, and a weight average molecular weight (Mw) of 5,000.

<Synthesis of Crystalline Polyester Resin (A-1)>
In a reaction vessel equipped with a cooling tube, a heating/cooling device, a thermometer, a stirrer and a nitrogen inlet tube, 500 parts of the crystalline portion (a1) and 500 parts of the non-crystalline portion (a2) were placed and subjected to an ester exchange reaction for 30 hours under a nitrogen stream at 150°C. The removed resin was cooled to room temperature and then crushed into particles to obtain a crystalline polyester resin (A-1). The weight average molecular weight (Mw) of the crystalline polyester resin (A-1) was 11,400, the peak top temperature (Tm) of the endothermic peak was 78°C, the endothermic amount at the endothermic peak was 56 J/g, the half-width at the endothermic peak was 5°C, the acid value was 2 mgKOH/g, and the hydroxyl value was 27 mgKOH/g.

<Production Example 2> [Synthesis of Crystalline Polyester Resin (A-2)]
Except for using the raw materials described in Production Example 2 in Table 1, the crystalline portion (a1) and the amorphous portion (a2) were obtained in the same manner as in Production Example 1, and then 500 parts of the crystalline portion (a1) and 500 parts of the amorphous portion (a2) were placed in a reaction vessel equipped with a cooling tube, a heating and cooling device, a thermometer, a stirrer and a nitrogen inlet tube, and subjected to an ester exchange reaction at 150 ° C. under a nitrogen stream for 30 hours. The removed resin was cooled to room temperature, then pulverized and granulated to obtain a crystalline polyester resin (A-2). The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half-width at the endothermic peak, acid value, and hydroxyl value of the obtained crystalline polyester resin are described in Table 1.

<Production Example 3> [Synthesis of Crystalline Polyester Resin (A-3)]
Except for using the raw materials described in Production Example 3 in Table 1, the crystalline portion (a1) and the amorphous portion (a2) were obtained in the same manner as in Production Example 1, and then 200 parts of the crystalline portion (a1) and 800 parts of the amorphous portion (a2) were placed in a reaction vessel equipped with a cooling tube, a heating and cooling device, a thermometer, a stirrer and a nitrogen inlet tube, and subjected to an ester exchange reaction at 150 ° C. under a nitrogen stream for 30 hours. The removed resin was cooled to room temperature, and then crushed and granulated to obtain a crystalline polyester resin (A-3). The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half-width at the endothermic peak, acid value, and hydroxyl value of the obtained crystalline polyester resin are described in Table 1.

<Production Example 4> [Synthesis of Crystalline Polyester Resin (A-4)]
Except for using the raw materials described in Production Example 4 in Table 1, the crystalline portion (a1) and the amorphous portion (a2) were obtained in the same manner as in Production Example 1, and then 700 parts of the crystalline portion (a1) and 300 parts of the amorphous portion (a2) were placed in a reaction vessel equipped with a cooling tube, a heating and cooling device, a thermometer, a stirrer and a nitrogen inlet tube, and subjected to an ester exchange reaction at 150 ° C. under a nitrogen stream for 30 hours. The removed resin was cooled to room temperature, and then crushed and granulated to obtain a crystalline polyester resin (A-4). The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half-width at the endothermic peak, acid value, and hydroxyl value of the obtained crystalline polyester resin are described in Table 1.

<Production Example 5> [Synthesis of Crystalline Polyester Resin (A-5)]
Except for using the raw materials described in Production Example 5 in Table 1, the crystalline portion (a1) and the amorphous portion (a2) were obtained in the same manner as in Production Example 1, and then 700 parts of the crystalline portion (a1) and 300 parts of the amorphous portion (a2) were placed in a reaction vessel equipped with a cooling tube, a heating and cooling device, a thermometer, a stirrer and a nitrogen inlet tube, and subjected to an ester exchange reaction at 150 ° C. under a nitrogen stream for 30 hours. The removed resin was cooled to room temperature, and then crushed and granulated to obtain a crystalline polyester resin (A-5). The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half-width at the endothermic peak, acid value, and hydroxyl value of the obtained crystalline polyester resin are described in Table 1.

Comparative Production Example 1 Synthesis of Polyester Resin (AR-1)
A polyester resin (AR-1) was obtained in the same manner as in <Synthesis of crystal portion (a1)> of Production Example 1, except that the raw materials described in Comparative Production Example 1 in Table 1 were used. The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half width at the endothermic peak, acid value, and hydroxyl value of the obtained polyester resin are shown in Table 1.

Comparative Production Example 2 Synthesis of Polyester Resin (AR-2)
A polyester resin (AR-2) was obtained in the same manner as in <Synthesis of amorphous portion (a2)> in Production Example 1, except that the raw materials described in Comparative Production Example 2 in Table 1 were used. The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half width at the endothermic peak, acid value, and hydroxyl value of the obtained polyester resin are shown in Table 1. Note that (AR-2) did not have an endothermic peak.

Comparative Production Example 3 Synthesis of Polyester Resin (AR-3)
A polyester resin (AR-3) was obtained in the same manner as in <Synthesis of amorphous portion (a2)> in Production Example 1, except that the raw materials described in Comparative Production Example 3 in Table 1 were used. The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half width at the endothermic peak, acid value, and hydroxyl value of the obtained polyester resin are shown in Table 1. Note that (AR-3) did not have an endothermic peak.

Comparative Production Example 4 Synthesis of Polyester Resin (AR-4)
A polyester resin (AR-4) was obtained in the same manner as in <Synthesis of crystal portion (a1)> of Production Example 1, except that the raw materials described in Comparative Production Example 4 in Table 1 were used. The weight average molecular weight (Mw), peak top temperature (Tm) of the endothermic peak, endothermic amount at the endothermic peak, half width at the endothermic peak, acid value, and hydroxyl value of the obtained polyester resin are shown in Table 1.

The compositions and resin properties of the crystalline polyester resins (A) obtained in Production Examples 1 to 5 and the polyester resins (AR) obtained in Comparative Production Examples 1 to 4 are shown in Table 1.

<Production Example 6> [Synthesis of amorphous polyester resin (B-1)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 193 parts (14.6 mol%) of bisphenol A·PO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-2P"), 539 parts (35.4 mol%) of bisphenol A·PO 3-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-3P"), 173 parts (26.7 mol%) of terephthalic acid, 67 parts (11.8 mol%) of adipic acid, 86 parts (11.5 mol%) of trimellitic anhydride, and 3.6 parts of titanium dihydroxybis(triethanolamine) as a condensation catalyst were placed and reacted at 220°C for 20 hours while distilling off the water produced. The reaction was further carried out under a reduced pressure of 0.5 to 2.5 kPa, and when the temperature had dropped by half to 150°C, the mixture was taken out using a steel belt cooler. The extracted resin was pulverized into particles to obtain amorphous polyester resin (B-1). The amorphous polyester resin (B-1) had a half drop temperature of 150° C., a glass transition temperature Tg of 60° C., an acid value of 23 mg KOH/g, a hydroxyl value of 1 mg KOH/g, and a weight average molecular weight Mw of 130,000.

<Production Example 7> [Synthesis of amorphous polyester resin (B-2)]
In another reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 324 parts (20.0 mol%) of bisphenol A·PO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-2P"), 443 parts (30.0 mol%) of bisphenol A·EO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BPE-20"), 280 parts (47.7 mol%) of terephthalic acid, and 3.0 parts of titanium dihydroxybis(triethanol aminate) as a condensation catalyst were added, and the mixture was heated to 230°C under a reduced pressure of 0.5 to 2.5 kPa while distilling off the water produced, and reacted until the acid value was less than 2 mgKOH/g. The mixture was then cooled to 180°C, and 14 parts (2.3 mol%) of trimellitic anhydride was added, reacted under normal pressure for 1 hour and taken out. The extracted resin was cooled to room temperature and then pulverized into particles to obtain amorphous polyester resin (B-2). The amorphous polyester resin (B-2) had a half drop temperature of 97° C., a glass transition temperature (Tg) of 58° C., an acid value of 8 mg KOH/g, a hydroxyl value of 55 mg KOH/g, and a weight average molecular weight (Mw) of 5,000.

The composition and resin properties of the amorphous polyester resin (B) obtained in Production Examples 6 and 7 are shown in Table 2.

<Production Example 8> [Synthesis of Graft Polymer (C-1)]
300 parts of xylene and 100 parts of low molecular weight polyethylene (Sanyo Chemical Industries, Ltd., Sanwax 151P: softening point 107 ° C.) were charged into an autoclave, and after replacing with nitrogen, the temperature was raised to 165 ° C. in a sealed state with stirring. A mixed solution of 100 parts of acrylonitrile [manufactured by Nacalai Tesque, Inc.], 850 parts of styrene [manufactured by Idemitsu Kosan Co., Ltd.], 50 parts of butyl acrylate, 37 parts of di-t-butyl peroxide [Perbutyl D, manufactured by NOF Corp., the same applies below], and 80 parts of xylene was dropped at 165 ° C. over 3 hours to polymerize, and the temperature was further maintained for 30 minutes. The solvent was then removed to obtain a graft polymer (C-1). The graft polymer (C-1) had a ½ drop temperature of 112° C., a glass transition temperature (Tg) of 65° C., an acid value of 0 mgKOH/g, a weight average molecular weight (Mw) of 19,200, and an average value based on the molar fraction of the SP values of the monomers constituting the side chains of 10.9 (cal/cm ³ ) ^½ .

<Production Examples 9 to 13> [Synthesis of Graft Polymers (C-2) to (C-6)]
Graft polymers (C-2) to (C-6) were obtained in the same manner as in Production Example 8, except that the raw materials shown in Production Examples 9 to 13 in Table 3 were used. The 1/2 drop temperature, glass transition temperature (Tg), acid value, weight average molecular weight (Mw), and average values based on the molar fraction of the SP values of the monomers constituting the side chains of the obtained graft polymers are shown in Table 3.

Example 1 Preparation of Toner Binder (D-1)
20 parts of crystalline polyester resin (A-1), 30 parts of amorphous polyester resin (B-1), 70 parts of amorphous polyester resin (B-2), and 5 parts of graft polymer (C-1) were premixed using a Henschel mixer [FM10B, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.], and then kneaded in a twin-screw kneader [PCM-30, manufactured by Ikegai Corporation] to obtain a toner binder (D-1).

<Examples 2 to 10> [Preparation of toner binders (D-2) to (D-10)]
Toner binders (D-2) to (D-10) were obtained in the same manner as in Example 1, except that the raw materials shown in Examples 2 to 10 in Table 4 were used.

Comparative Examples 1 to 6 [Preparation of Toner Binders (D'-1) to (D'-6)]
Toner binders (D'-1) to (D'-6) were obtained in the same manner as in Example 1, except that the raw materials shown in Comparative Examples 1 to 6 in Table 4 were used.

The compositions and evaluation results of the toner binders (D) obtained in Examples 1 to 10 and the toner binders (D') obtained in Comparative Examples 1 to 6 are shown in Table 4.

[Evaluation method]
Toners were prepared by the following method using the toner binders obtained in Examples 1 to 10 and Comparative Examples 1 to 6, and the dispersibility, low-temperature fixing property, chargeability, heat-resistant storage stability, and fixing strength were evaluated.
[Toner Production]
100 parts of toner binder, 8 parts of carbon black pigment "MA-100" [manufactured by Mitsubishi Chemical Corporation] as a colorant, 4 parts of paraffin wax "HNP-9" [manufactured by Nippon Seiro Co., Ltd.] as a release agent, and 1 part by weight of charge control agent "T-77" [manufactured by Hodogaya Chemical Co., Ltd.] were added and premixed using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Engineering Co., Ltd.], and then kneaded with a twin-screw kneader [PCM-30 manufactured by Ikegai Corporation].
The resulting resin particles were then finely pulverized using a supersonic jet mill, Labojet (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and classified using an air classifier (MDS-I, manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain resin particles having a volume average particle size of 5 μm and a particle size distribution of 1.2. The obtained resin particles (99 parts) were mixed with 1 part of a hydrophobic silica fluidizing agent, Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.), using a sample mill to obtain a toner.

<Dispersibility> (Maximum particle size of crystalline polyester resin, average particle size of crystalline polyester resin)
A cross section of the toner observed by a transmission electron microscope (TEM) was prepared as follows. The obtained toner was embedded in a visible light curable embedding resin (D-800, manufactured by Nisshin EM Co., Ltd.), cut to a thickness of 60 nm by an ultrasonic ultramicrotome (EM5, manufactured by Leica), and ruthenium stained by a vacuum staining device (manufactured by Filgen Co., Ltd.). Thereafter, the dispersion state of the crystalline polyester resin was observed from the cross section of the obtained toner using a transmission electron microscope (H7500, manufactured by Hitachi High-Technologies Corporation) at an acceleration voltage of 120 kV. The long diameter of the crystalline polyester resin with the largest long diameter in the entire observed image was taken as the maximum particle size. In addition, image processing was performed on randomly selected enlarged images (×1000) using the free software “image J” according to the following procedure, and the calculated “mean ferret” was taken as the average particle size of the crystalline polyester resin. Under these evaluation conditions, it is preferable that the maximum particle size of the crystalline polyester resin is 1.0 μm or less, and the maximum particle size of the crystalline polyester resin is 0.5 μm or less. In the toner binders of Comparative Examples 4 and 5, dispersion of the crystalline polyester resin was not confirmed.

1. image type → 8bit
2. line → analyze → set scale
→ known distance 5.0
3. process → binary → median filter 10
4. image → adjust → threshold
5. process → binary → fill hole
6. analyze particle
(set mesearements → feret diameter)

<Low temperature fixability> (MFT)
The toner was uniformly placed on the paper surface to a density of 0.6 mg/ ^cm2 . The powder was placed on the paper surface using a printer without a thermal fixing device. Other methods may be used as long as the powder can be uniformly placed at the above weight density. The paper was passed through a pressure roller at a fixing speed (heating roller peripheral speed) of 213 mm/sec and a fixing pressure (pressure roller pressure) of 10 kg/ ^cm2 , and the heating roller temperature range was changed from 90 to 230°C in 5°C increments, to create fixed images at each temperature. Next, the presence or absence of cold offset in each fixed image was visually confirmed in ascending order of heating roller temperature, and the temperature at which cold offset no longer occurred was shown in Table 4 as MFT (°C).
The lower the temperature at which cold offset does not occur, the better the low-temperature fixing property. Under these evaluation conditions, it is generally preferable that the MFT is 125° C. or less.

<Chargeability> (charge amount)
0.5 g of toner and 10 g of ferrite carrier (F-150, manufactured by Powder Tech Co., Ltd.) were placed in a 50 ml glass bottle, which was then conditioned for 8 hours at 23° C. and a relative humidity of 50%. The glass bottle containing the conditioned toner was sealed and set in a Turbula shaker mixer and subjected to friction stirring at 90 rpm for 2 minutes. 0.2 g of the mixed powder after stirring was loaded into a blow-off powder charge amount measuring device equipped with a stainless steel wire mesh with a mesh size of 20 μm. The charge amount of the remaining ferrite carrier was measured under conditions of a blow pressure of 10 KPa and a suction pressure of 5 KPa, and the charge amount (μC/g) of the toner was calculated by a standard method.
For toner, the higher the negative charge amount, the better the charging characteristics are, and it is preferable that the negative charge amount is -15 μC/g or less.
The charge amount was measured using a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co., Ltd.).

<Heat-resistant storage stability> (degree of agglomeration)
1 g of toner and 0.013 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed for 1 hour using a shaker, the mixture was placed in a sealed container, and left to stand for 48 hours in an atmosphere at a temperature of 45° C. and a humidity of 80%. The degree of aggregation was measured and the heat resistance storage stability was evaluated.
The lower the value in the cohesion test determined by the following method, the more excellent the heat-resistant storage stability. Under these evaluation conditions, a value of 3% or less is preferable.
Equipment: POWDER TESTER model PT-X (manufactured by Hosokawa Micron)
Sieve openings: 355 μm, 250 μm, 150 μm
Vibration amplitude: 1mm
Vibration time: 30 seconds Operation method: Set the sieves on the vibration table of the powder tester in the following order: upper 355 μm, middle 250 μm, and lower 150 μm. Place 1 g of toner on the upper sieve and vibrate with a vibration amplitude of 1 mm for 30 seconds. The weight of the toner remaining on each sieve was measured.
Cohesion degree: Calculated from the weight of the toner used in the measurement and the weight of the toner remaining after sieving.
Cohesion degree (%) = (U/N + M/N x 3/5 + L/N x 1/5) x 100
U: weight of upper stage, M: weight of middle stage, L: weight of lower stage, N: weight of sample (1g)

<Fixing strength> (Tape peeling)
The fixing strength of the fixed image in the MFT prepared for the evaluation of low-temperature low-adhesion property was evaluated by a tape peeling test. After attaching a tape ("Scotch Mending Tape" manufactured by 3M) to the fixed image, the tape was peeled off, and the image density (ID) of the image attached to the tape was measured by a reflection densitometer (product name "X-Rite model 404", manufactured by X-Rite). The smaller the image density (numerical value) of the attached image, the higher the fixing strength. Under these evaluation conditions, it is preferable that it is 0.2 or less.

<Fixing strength> (pencil hardness)
The MFT fixed image prepared in the evaluation of low-temperature adhesion was subjected to a scratch hardness test in accordance with JIS K5600-5-4 (1999) by applying a load of 10 g from directly above a pencil fixed at a 45-degree angle by hand scratching, and the image strength was evaluated based on the pencil hardness at which the image was not scratched. The higher the pencil hardness, the better the image strength. Generally, it is preferable that the pencil hardness is HB or higher.

As is clear from the evaluation results in Table 4, the toner binders (D-1) to (D-10) had good dispersibility, and all of them obtained excellent results in all performance evaluations.
On the other hand, the toner binders (D'-1) to (D'-6) did not have sufficient dispersibility, and were poor in other performance items.

The toner binder of the present invention can be suitably used as an electrophotographic toner used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing and the like.
Further, it is suitable for use as an additive for paints, an additive for adhesives, particles for electronic paper, and the like.

Claims (6)

A toner binder containing a crystalline polyester resin (A), an amorphous polyester resin (B), and a graft polymer (C), in which the crystalline polyester resin (A) is a polyester resin obtained by reacting an alcohol component (x) and a carboxylic acid component (y) as raw materials, the alcohol component (x) contains an aliphatic diol (x1) having 2 to 36 carbon atoms, the content of (x1) in (x) being 20 to 80 mol% based on the total number of moles of (x), and the carboxylic acid component (y) is an aliphatic dicarboxylic acid having 4 to 36 carbon atoms. A toner binder comprising an acid (y1), the content of (y1) in (y) being 20 to 80 mol% based on the total number of moles of (y), the crystalline polyester resin (A) having an endothermic peak top temperature (Tm) of 50°C to 85°C as measured by a differential scanning calorimeter (DSC), the endothermic peak width of the crystalline polyester resin (A) being 7°C or less, and the graft polymer (C) being a polymer having a side chain branched from a polyolefin having ethylene and/or propylene as essential constituent monomers. The toner binder according to claim 1, wherein the crystalline polyester resin (A) has an endothermic amount of 20 to 90 J/g based on an endothermic peak measured by a differential scanning calorimeter (DSC). The toner binder according to claim 1, wherein the crystalline polyester resin (A) is a resin obtained by an ester exchange reaction between a crystalline portion (a1) and an amorphous portion (a2), and the weight ratio (a1/a2) of the crystalline portion (a1) to the amorphous portion (a2) is 20/80 to 70/30. The toner binder according to claim 1, wherein the weight ratio (A/B) of the crystalline polyester resin (A) to the amorphous polyester resin (B) is 10/90 to 40/60. 2. The toner binder according to claim ^1, wherein the graft polymer (C) is a polymer of a monomer having a vinyl group in a side chain, and the average SP value based on the molar fraction of the monomer is 10.3 to 12.3 (cal/cm ³ ) 1/2. The toner binder according to claim 1, wherein the amorphous polyester resin (B) is a polyester resin obtained by reacting an alcohol component (X) and a dicarboxylic acid component (Y) as raw materials, and the alcohol component (X) contains an alkylene oxide adduct of bisphenol A (X1).