Toner for development of electrostatic charge images

Abstract

A toner for electrostatic image development containing a crystalline polyester resin C and an amorphous polyester resin A, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing ethylene glycol in an amount of 70% by mol or more and a carboxylic acid component containing an aliphatic dicarboxylic acid compound, the alcohol component and / or the carboxylic acid component contains a monofunctional monomer, the amorphous polyester resin A is a polycondensate of an alcohol component and a carboxylic acid component and a polyethylene terephthalate. The toner for electrostatic image development of the present invention is suitably used in the development and the like of latent images formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Description

TECHNICAL FIELD

[0001] The present invention relates to a toner for electrostatic image development used in development of latent images formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.BACKGROUND ART

[0002] A toner for electrostatic image development has been proposed that contains a binder resin containing both of an amorphous polyester resin introduced with a polyethylene terephthalate and a crystalline polyester resin prepared by using ethylene glycol as an alcohol component, exhibiting high affinity between the two (see, Patent Publication 1).

[0003] On the other hand, a polyester resin in which a monovalent longchain aliphatic monomer is used as a raw material monomer effective for reduction of hygroscopicity has been proposed (see, Patent Publication 2).

[0004] Patent Publication 1: Japanese Patent Laid-Open No.2019-66536 Patent Publication 2: Japanese Patent Laid-Open No.2021-189196 SUMMARY OF THE INVENTION

[0005] The present invention relates to a toner for electrostatic image development containing a crystalline polyester resin C and an amorphous polyester resin A, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing ethylene glycol in an amount of 70% by mol or more and a carboxylic acid component containing an aliphatic dicarboxylic acid compound, the alcohol component and / or the carboxylic acid component contains a monofunctional monomer, and the amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component and a polyethylene terephthalate.DETAILED DESCRIPTION OF THE INVENTION

[0006] Although a crystalline polyester resin is used for improving low-temperature fusing ability of a toner, if the control of the dispersing condition in the toner is insufficient, charge stability is likely affected. Further, recently, a situation where more stringent thermal resistance is required demands concurrently securing pressurized storage property.

[0007] The present invention relates to a toner for electrostatic image development having excellent charge stability and pressurized storage property.

[0008] The toner for electrostatic image development of the present invention exhibits excellent effects in charge stability and pressurized storage property.

[0009] The toner for electrostatic image development of the present invention is characterized by containing a crystalline polyester resin (crystalline polyester resin C) prepared by using ethylene glycol and a monofunctional monomer, and an amorphous polyester resin (amorphous polyester resin A) prepared by using a polyethylene terephthalate (PET). Although the reason why the toner for electrostatic image development of the present invention has excellent charge stability and pressurized storage property is not clear, the reason is assumed as follows.

[0010] In a crystalline polyester resin containing ethylene glycol as a main component of an alcohol component, and a component derived from a monofunctional monomer, the component derived from the monofunctional monomer is a terminal structure of a resin, and is more hydrophobic as compared to terminus of a carboxylic group or a hydroxide group. On the other hand, a PET of an amorphous polyester resin obtained by using the PET is incorporated into a polyester resin chain by a transesterification reaction in a polycondensation reaction of an alcohol component, a carboxylic acid component and the PET while the PET being subjected to depolymerization. However, the PET is not completely randomized, and the PET presents as a unit having a certain extent of length called as a PET segment in a resin. Since the affinity of the PET segment and a crystalline polyester resin containing ethylene glycol as a main component of an alcohol component is high, the dispersibility of the crystalline polyester resin to the amorphous polyester resin is improved, and crystallization is promoted. Consequently, the toner exhibits good storage stability even under a pressurized condition, and additionally, a hydrophobic terminus derived from a monofunctional monomer is oriented toward outside from a domain of a crystalline polyester resin with improved dispersibility near the surface of a toner particle. Therefore, it is thought that hygroscopicity of the toner is reduced and the toner has excellent charge stability.

[0011] The crystalline polyester resin C is a polycondensate of an alcohol component containing ethylene glycol as a main component and a carboxylic acid component containing an aliphatic dicarboxylic acid compound.

[0012] The content of the ethylene glycol is 70% by mol or more, preferably 80% by mol or more, more preferably 90% by mol or more, and even more preferably 95% by mol or more, and the content is 100% by mol or less in the alcohol component, and in the case where the alcohol component contains monoalcohol, the content is preferably 98% by mol or less, and more preferably 95% by mol or less in the alcohol component.

[0013] Other alcohol components include aliphatic diols other than the ethylene glycol, such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediaol, 1,10-decanedioal, 1,11 -undecanediol, and 1,12-dodecanediol, aromatic diols such as an alkylene oxide adduct of a bisphenol A and bisphenol A, hydrogenated bisphenol A, trihydric or higher polyhydric alcohol such as sorbitol, pentaerythritol, glycerol, and trimethylolpropane, and the like.

[0014] The aliphatic dicarboxylic acid compound includes succinic acid (number of carbon atoms: 4), fumaric acid (number of carbon atoms: 4), adipic acid (number of carbon atoms: 6), suberic acid (number of carbon atoms: 8), azelaic acid (number of carbon atoms: 9), sebacic acid (number of carbon atoms: 10), dodecanedioic acid (number of carbon atoms: 12), tetradecanedioic acid (number of carbon atoms: 14), succinic aid having an alkyl group or an alkenyl group at a side chain, anhydrides of these acids, alkyl esters of which alkyl has 1 or more carbon atoms and 3 or less carbon atoms of these acids, and the like. Here, when the aliphatic dicarboxylic acid compound is an alkyl ester, the number of carbon atoms of the alkyl group is not included in the carbon atoms mentioned above.

[0015] The number of carbon atoms of the aliphatic dicarboxylic acid compound is preferably 4 or more, more preferably 8 or more, even more preferably 10 or more, and even more preferably 12 or more, from the viewpoint of hydrophobicity, and the number of carbon atoms is preferably 16 or less, and more preferably 14 or less, from the viewpoint of low-temperature fusing ability.

[0016] The aliphatic dicarboxylic acid compound may be a saturated aliphatic dicarboxylic acid compound or a unsaturated aliphatic dicarboxylic acid compound, and the aliphatic dicarboxylic acid compound is preferably a saturated aliphatic dicarboxylic acid compound, from the viewpoint of pressurized storage property.

[0017] The content of the aliphatic dicarboxylic acid compound is preferably 80% by mol or more, more preferably 90% by mol or more, and even more preferably 95% by mol or more, and the content is 100% by mol or less in the carboxylic acid component, from the viewpoint of pressurized storage property. In a case where the carboxylic acid component contains a monocarboxylic acid compound, the content is preferably 98% by mol or less, and more preferably 95% by mol or less in the carboxylic acid component.

[0018] Other carboxylic acid components include an aromatic dicarboxylic acid compound such as phthalic acid, isophthalic acid and terephthalic acid, tricarboxylic or higher polycarboxylic acid compound such as trimellitic acid and pyromellitic acid, and the like.

[0019] Further, the alcohol component and / or the carboxylic acid component of the crystalline polyester resin C contains a monofunctional monomer.

[0020] The monofunctional monomer contained in the alcohol component includes aliphatic monoalcohol such as capryl alcohol, capric alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, and behenyl alcohol, and the like.

[0021] The monofunctional monomer contained in the carboxylic acid component includes an aliphatic monocarboxylic acid compound such as an aliphatic monocarboxylic acid such as caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid, alkyl esters of which alkyl has 1 or more carbon atoms and 3 or less carbon atoms of an alkyl group of these acids, and the like.

[0022] The monofunctional monomer preferably contains an aliphatic monocarboxylic acid compound and / or an aliphatic monoalcohol, from the viewpoint of improving hydrophobicity.

[0023] The number of carbon atoms of the aliphatic monoalcohol is preferably 6 or more, more preferably 9 or more, even more preferably 10 or more, and even more preferably 12 or more, from the viewpoint of hydrophobicity, and the number of carbon atoms is preferably 24 or less, more preferably 23 or less, and even more preferably 22 or less, from the viewpoint of low-temperature fusing ability.

[0024] The number of carbon atoms of the aliphatic monocarboxylic acid compound is preferably 6 or more, more preferably 9 or more, and even more preferably 10 or more, from the viewpoint of hydrophobicity, and the number of carbon atoms is preferably 24 or less, more preferably 23 or less, and even more preferably 22 or less, from the viewpoint of low-temperature fusing ability. Here, in a case where aliphatic monocarboxylic acid compound is alkyl ester, the number of carbon atoms of an alkyl group is not contained in the above-mentioned number of carbon atoms.

[0025] The content of the monofunctional monomer is preferably 2% by mol or more, more preferably 3% by mol or more, and even more preferably 5% by mol or more, and the content is preferably 30% by mol or less, more preferably 25% by mol or less, and even more preferably 20% by mol or less, from the viewpoint of pressurized storage property, in a total amount of the alcohol component and the carboxylic acid component.

[0026] Here, in the present specification, a macromonomer or a hydroxy carboxylic acid is not contained in the alcohol component and the carboxylic acid component.

[0027] Equivalent molar ratio of a carboxylic group of the carboxylic acid component to a hydroxylic group of the alcohol component, COOH group or groups / OH group or groups is preferably 0.8 or more, and more preferably 0.9 or more, from the viewpoint of pressurized storage property, and the equivalent molar ratio is preferably 1.2 or less, and more preferably 1.1 or less, from the viewpoint of low-temperature fusing ability.

[0028] The crystalline polyester resin C can be produced by, for example, polycondensing the alcohol component and the carboxylic acid component in an atmosphere of inert gas, in the presence of preferably an esterification catalyst, and further optionally in the presence of a promoter, a polymerization inhibitor and the like, at a temperature of preferably 120°C or more and 230°C or less.

[0029] The esterification catalyst includes tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate; titanium compounds such as titanium diisopropoxy bis(triethanolaminate) and titanium dihydroxy bis(triethanolaminate); and the like. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, and more preferably 0.1 parts by mass or more, and the amount is preferably 1.5 parts by mass or less, and more preferably 1 part by mass or less, based on 100 parts by mass of a total amount of the alcohol component and the carboxylic acid component. The promoter for the esterification catalyst includes gallic acid and the like. The amount of the promoter used is preferably 0.001 parts by mass or more, and more preferably 0.01 parts by mass or more, and the amount is preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, based on 100 parts by mass of a total amount of the alcohol component and the carboxylic acid component. The polymerization inhibitor includes tert-butyl catechol and the like. The amount of the polymerization inhibitor used is preferably 0.001 parts by mass or more, and more preferably 0.01 parts by mass or more, and the amount is preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, based on 100 parts by mass of a total amount of the alcohol component and the carboxylic acid component.

[0030] Here, in the present invention, the polyester resin may be a polyester resin that is modified to an extent that the properties thereof are not substantially impaired. The modified polyester resin includes, for example, a polyester resin grafted or blocked with a phenol, a urethane, an epoxy or the like according to a method described in Japanese Patent Laid-Open No. Hei-11-133668, Japanese Patent Laid-Open Hei-10-239903, Japanese Patent Laid-Open Hei-8-20636, or the like. Among the modified polyester resins, urethane-modified polyester resins in which polyester resins are urethane-extended with a polyisocyanate compound are preferred.

[0031] The softening point of the crystalline polyester resin C is preferably 50°C or more, more preferably 65°C or more, and even more preferably 70°C or more, from the viewpoint of pressurized storage property, and the softening point is preferably 120°C or less, and more preferably 110°C or less, from the viewpoint of low-temperature fusing ability.

[0032] Here, the crystallinity of a resin is expressed by a crystallinity index, which is defined by a ratio of a softening point to a temperature of the maximum endothermic peak as determined by a differential scanning calorimeter, i.e. a value of [softening point / temperature of the maximum endothermic peak].

[0033] The crystalline resin is a resin having a crystallinity index of 0.6 or more, preferably 0.7 or more, and more preferably 0.9 or more, and a resin having a crystallinity index of 1.4 or less, preferably 1.2 or less, and more preferably 1.1 or less.

[0034] On the other hand, the amorphous resin is a resin in which no endothermic peak is observed, or if the endothermic peak is observed, the amorphous resin is a resin having a crystallinity index exceeding 1.4, and preferably exceeding 1.5, and more preferably 1.6 or more, or a resin having a crystallinity index of less than 0.6, and preferably 0.5 or less.

[0035] The crystallinity of the resin can be adjusted by the kinds and the ratios of the raw material monomers, and the production conditions (for example, reaction temperatures, reaction time, cooling rate) or the like. Here, the temperature of the maximum endothermic peak refers to a temperature of the peak having the largest peak area, among the observed endothermic peaks. In a crystalline resin, the temperature of the maximum endothermic peak is defined as a melting point.

[0036] The melting point of the crystalline polyester resin C is preferably 60°C or more, and more preferably 70°C or more, from the viewpoint of pressurized storage property, and the melting point is preferably 130°C or less, and more preferably 120°C or less, from the viewpoint of low-temperature fusing ability.

[0037] The acid value of the crystalline polyester resin C is preferably 1 mgKOH / g or more, and more preferably 3 mgKOH / g or more, from the viewpoint of charge stability, and the acid value is preferably 20 mgKOH / g or less, and more preferably 15 mgKOH / g or less, from the viewpoint of pressurized storage property.

[0038] The content of the crystalline polyester resin C is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, from the viewpoints of low-temperature fusing ability and the pressurized storage property, and the content is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of pressurized storage property, in a total amount of the crystalline polyester resin C and the amorphous polyester resin A.

[0039] The amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component and a PET.

[0040] The alcohol component preferably contains an aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms, from the viewpoints of pressurized storage property and charge stability.

[0041] The aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms includes 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol and the like. Among them, a neopentyl glycol is preferred from the viewpoint of pressurized storage property.

[0042] The content of the aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms is preferably 30% by mol or more, more preferably 40% by mol or more, and even more preferably 50% by mol or more in the alcohol component, from the viewpoint of pressurized storage property, and the content is 100% by mol or less in the alcohol component. In a case where the alcohol component contains trihydric or higher polyhydric alcohol, the content is preferably 98% by mol or less, and more preferably 90% by mol or less in the alcohol component. However, the alcohol component, as used herein, does not contain ethylene glycol unit of the PET.

[0043] Other alcohol components include a trihydric or higher polyhydric alcohol, including an aliphatic diol having carbon atoms of 7 or more, an aromatic diol such as an alkylene oxide adduct of bisphenol A and bisphenol A, a hydrogenated bisphenol A, trihydric or higher polyhydric alcohol such as a sorbitol, a pentaerythritol, glycerol, and trimethylolpropane, and the like.

[0044] The carboxylic acid component preferably contains an aromatic dicarboxylic acid compound, from the viewpoint of charge stability.

[0045] The aromatic dicarboxylic acid compound includes phthalic acid, isophthalic acid, terephthalic acid, anhydride of these acids, alkyl esters of which alkyl has 1 or more carbon atoms and 3 or less carbon atoms of these acids, and the like.

[0046] The content of the aromatic dicarboxylic acid compound is preferably 70% by mol or more, more preferably 80% by mol or more, even more preferably 90% by mol or more, and even more preferably 95% by mol or more, and the content is 100% by mol or less in the carboxylic acid component. In a case where the carboxylic acid component contains a tricarboxylic or higher polycarboxylic acid compound, the content is preferably 98% by mol or less, and more preferably 90% by mol or less in the carboxylic acid component. However, the carboxylic acid component, as used herein, does not include a terephthalic acid unit contained in the PET.

[0047] The carboxylic acid component other than the aromatic dicarboxylic acid compound includes aliphatic dicarboxylic acid such as fumaric acid, maleic acid, succinic acid, a succinate derivative substituted with a hydrocarbon group, glutaric acid, adipic acid, and sebacic acid, tricarboxylic or higher polycarboxylic acid, such as trimellitic acid, and pyromellitic acid, anhydrides of these acids, alkyl esters of which alkyl has 1 or more carbon atoms and 3 or less carbon atoms of these acids, and the like.

[0048] A trivalent or higher polyvalent raw material monomer may be used as the alcohol component and / or the carboxylic acid component of an amorphous polyester resin A, from the viewpoint of adjusting softening point. In that case, it is preferred that a trihydric or higher polyhydric alcohol, preferably glycerol or trimethylol propane, and more preferably glycerol is used, from the viewpoint of charge stability. The content of the trivalent or higher polyvalent raw material monomer is preferably 2% by mol or more, and more preferably 4% by mol or more, and the content is preferably 25% by mol or less, and more preferably 20% by mol or less in a total amount of the alcohol component, the carboxylic acid component and the PET.

[0049] The alcohol component may properly contain a monohydric alcohol and the carboxylic acid component may properly contain a monocarboxylic carboxylic acid compound.

[0050] A PET is incorporated into a polyester resin by polycondensation reaction of the alcohol component and the carboxylic acid component, and / or by subjecting ethylene glycol and terephthalic acid generated by depolymerization of a part of a PET to polycondensation reaction as a raw material monomer. A PET is an equimolar polycondensate of ethylene glycol and terephthalic acid, and the ethylene glycol and the terephthalic acid constituting a PET are considered as the alcohol component and the carboxylic acid component, respectively.

[0051] The PET may be a new Virgin PET or a recycled PET. The recycled PET is obtained by collecting a used PET, pulverizing the collected PET optionally after washing or selecting from other materials, degrading the pulverized PET into a monomer unit by depolymerization, and subjecting the degraded PET to resynthesis as a raw material.

[0052] In the present invention, the PET is preferably a PET having relatively lower IV value than ones of a conventionally used PET, i.e. a low molecular weight PET. Depolymerization of the PET more evenly proceeds by introducing the PET having a low IV value (low molecular weight) into a polyester resin.

[0053] The IV value of the PET is preferably 0.40 or more, more preferably 0.45 or more, even more preferably 0.50 or more, and even more preferably 0.55 or more, from the viewpoint described above, and the IV value is preferably 0.85 or less, more preferably 0.80 or less, even more preferably 0.75 or less, even more preferably 0.70 or less, and even more preferably 0.65 or less, from the viewpoints of low-temperature fusing ability and evenness of depolymerization. IV value is an intrinsic viscosity, which is used as an index of a molecular weight. The IV value of the PET can be adjusted by polycondensation time and the like.

[0054] Commercially available products of the PET having an IV value of 0.40 or more and 0.85 or less include RAMAPET L1 (manufactured by Indorama Ventures, IV value: 0.60), RAMAPET BF3067 (manufactured by Indorama Ventures, IV value: 0.65), RAMAPET N2G (manufactured by Indorama Ventures, IV value: 0.75), TRN-NTJ (manufactured by TEIJIN LIMITED, IV value: 0.53), TRN-RTJC (manufactured by TEIJIN LIMITED, IV value: 0.64), RAMAPET S1 (manufactured by Indorama Ventures, IV value: 0.84), UK-31 (manufactured by Utsumi Recycle Systems Inc, IV value: 0.67) and the like.

[0055] The content of the PET having a low IV value is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 100% by mass in a total amount of the PET subjected to the polycondensation.

[0056] The content of the PET is preferably 5% by mol or more, more preferably 10% by mol or more, even more preferably 15% by mol or more, and even more preferably 20% by mol or more, and the content is preferably 75% by mol or less, more preferably 70% by mol or less, and even more preferably 65% by mol or less in a total amount of the alcohol component, the carboxylic acid component and the PET, from the viewpoint of pressurized storage property. In a case where the amorphous polyester resin A is composed of two or more kinds of resins, a weighted mean value of the PET content of each resin is regarded as a PET content of an amorphous polyester resin A. Here, since the PET is a polycondensate of ethylene glycol and terephthalic acid, dimethyl terephthalate or the like, a unit of terephthalic acid-ethylene glycol (Mw: 192) is converted as one mole. Accordingly, the number of moles of the PET equals the number of moles of ethylene glycol unit equals the number of moles of terephthalic acid unit.

[0057] Equivalent molar ratio of the carboxylic acid component (including terephthalic acid units in the PET) to the alcohol component (including ethylene glycol units in the PET), COOH group or groups / OH group or groups is preferably 0.6 or more, more preferably 0.7 or more, and even more preferably 0.8 or more, and equivalent molar ratio is preferably 1.3 or less, and more preferably 1.2 or less.

[0058] The polycondensation reaction condition of the alcohol component, the carboxylic acid component and the PET of an amorphous polyester resin is similar to the reaction condition of the crystalline polyester resin, except that the suitable reaction temperature is preferably 130°C or more and more preferably 170°C or more, and preferably 250°C or less and more preferably 240°C or less.

[0059] The softening point of the amorphous polyester resin A is preferably 70°C or more, more preferably 90°C or more, and even more preferably 100°C or more, from the viewpoint of charge stability, and the softening point is preferably 170°C or less, more preferably 160°C or less, and even more preferably 150°C or less, from the viewpoint of low-temperature fusing ability.

[0060] Here, the amorphous polyester resin A may be composed of resins having different softening points, from the viewpoints of low-temperature fusing ability and fusing range. The difference of softening points of two kinds of resins is preferably 10°C or more, and more preferably 20°C or more, and the difference is preferably 60°C or less, and more preferably 40°C or less.

[0061] The softening point of the amorphous resin having a higher softening point, resin AH, is preferably 100°C or more, more preferably 110°C or more, and even more preferably 120°C or more, from the viewpoint of fusing range, and the softening point is preferably 170°C or less, more preferably 160°C or less, and even more preferably 150°C or less, from the viewpoint of low-temperature fusing ability.

[0062] In addition, the softening point of the amorphous resin having lower softening point, resin AL, is preferably 70°C or more, more preferably 90°C or more, and even more preferably 100°C or more, from the viewpoint of charge stability, and the softening point is preferably 130°C or less, more preferably 125°C or less, and even more preferably 120°C or less from the viewpoint of low-temperature fusing ability.

[0063] The mass ratio of the resin AH to the resin AL, i.e. resin AH / resin AL is preferably 10 / 90 or more, more preferably 20 / 80 or more, and even more preferably 30 / 70 or more, and the mass ratio is preferably 90 / 10 or less, more preferably 80 / 20 or less, and even more preferably 75 / 25 or less.

[0064] The glass transition temperature of the amorphous polyester resin A is preferably 40°C or more, and more preferably 50°C or more, from the viewpoint of pressurized storage property, and the glass transition temperature is preferably 80°C or less, and more preferably 70°C or less, from the viewpoint of charge stability.

[0065] The acid value of the amorphous polyester resin A is preferably 1 mgKOH / g or more, and more preferably 3 mgKOH / g or more, from the viewpoint of charge stability, and the acid value is preferably 20 mgKOH / g or less, and more preferably 18 mgKOH / g or less, from the viewpoint of pressurized storage property.

[0066] The content of the amorphous polyester resin A is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, and the content is preferably 97% by mass or less, more preferably 95% by mass or less, and even more preferably 92% by mass or less, in a total amount of the crystalline polyester resin C and the amorphous polyester resin A, from the viewpoints of charge stability and pressurized storage property.

[0067] The mass ratio of a crystalline polyester resin C to an amorphous polyester resin A, i.e. crystalline polyester resin C / amorphous polyester resin A is preferably 3 / 97 or more, more preferably 5 / 95 or more, and even more preferably 8 / 92 or more, and the mass ratio is preferably 30 / 70 or less, more preferably 25 / 75 or less, and even more preferably 20 / 80 or less, from the viewpoints of charge stability and pressurized storage property.

[0068] A crystalline polyester resin C and an amorphous polyester resin A are contained as a resin binder in a toner.

[0069] Other resin binders include a vinyl-based resin such as a styrene-acrylic resin, an epoxy resin, a polycarbonate, a polyurethane, a composite resin containing two or more kinds of these resins, and the like.

[0070] The total content of the crystalline polyester resin C and the amorphous polyester resin A is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass, in the resin binder.

[0071] In addition, the content of the resin binder is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, and the content is preferably less than 100% by mass, more preferably 98% by mass or less, and even more preferably 95% by mass or less, in the toner.

[0072] The toner for electrostatic image development of the present invention may contain, besides the resin binder, an additive such as a colorant, a releasing agent, a charge control agent, a magnetic powder, a flowability improver, an electric conductivity modifier, a reinforcing filler such as a fibrous material, an antioxidant, or a cleanability improver.

[0073] As the colorant, dyes, pigments, magnetic powder, and the like which are used as colorants for toners can be used. Examples include carbon blacks, Phthalocyanine Blue, Permanent Brown FG, Brilliant Fast Scarlet, Pigment Red 122, Pigment Green B, Rhodamine-B Base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, and the like. Here, in the present invention, the toners may be any one of black toners and color toners.

[0074] The content of the colorant is, based on 100 parts by mass of the resin binder, preferably 1 part by mass or more, and more preferably 2 parts by mass or more, and the content is preferably 40 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, from the viewpoints of improving optical density and low-temperature fusing ability of a toner.

[0075] The releasing agent includes hydrocarbon waxes such as polypropylene wax, polyethylene wax, ethylene-propylene copolymer wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and oxides thereof; ester-based waxes such as carnauba wax, montan wax and deacidified waxes thereof, and fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, metal salts of fatty acids, and the like. These releasing agents can be used alone or in a mixture of two or more kinds.

[0076] The melting point of the releasing agent is preferably 60°C or more, and more preferably 70°C or more, from the viewpoint of pressurized storage property of the toner, and the melting point is preferably 160°C or less, more preferably 140°C or less, even more preferably 120°C or less, and even more preferably 110°C or less, from the viewpoint of low-temperature fusing ability.

[0077] The content of the releasing agent is, based on 100 parts by mass of the resin binder, preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 1.5 parts by mass or more, and the content is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less, from the viewpoints of charge stability and pressurized storage property of the toner and the viewpoint of dispersibility into the resin binder.

[0078] The charge control agent may contain, but not particularly limited to, any of positively chargeable charge control agents and negatively chargeable charge control agents.

[0079] The positively chargeable charge control agent includes Nigrosine dyes, for example, "Nigrosine Base EX," "OIL BLACK BS," "OIL BLACK SO," "BONTRON N-01," "BONTRON N-04," "BONTRON N-07," "BONTRON N-09," "BONTRON N-11" (hereinabove manufactured by Orient Chemical Industries Co., Ltd.), and the like; triphenylmethanebased dyes containing a tertiary amine as a side chain; quaternary ammonium salt compounds, for example, "BONTRON P-51" (manufactured by Orient Chemical Industries Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (manufactured by Clariant, Ltd.), and the like; polyamine resins, for example, "AFP-B" (manufactured by Orient Chemical Industries Co., Ltd.), and the like; imidazole derivatives, for example, "PLZ-2001," "PLZ-8001" (hereinabove manufactured by SHIKOKU CHEMICALS CORPORATION), and the like; styrene-acrylic resins, for example, "FCA-701PT," "FCA-201-PS" (manufactured by Fujikura Kasei Co., Ltd.), and the like.

[0080] In addition, the negatively chargeable charge control agent includes metal-containing azo dyes, for example, "VARIFAST BLACK 3804," "BONTRON S-31, "BONTRON S-32," "BONTRON S-34," "BONTRON S-36" (hereinabove manufactured by Orient Chemical Industries Co., Ltd.), "AIZEN SPILON BLACK TRH," "T-77" (manufactured by Hodogaya Chemical Co., Ltd.), and the like; metal compounds of benzilic acid compounds, for example, "LR-147," "LR-297" (hereinabove manufactured by Japan Carlit Co., Ltd.), and the like; metal compounds of salicylic acid compounds, for example, "BONTRON E-81," "BONTRON E-84," "BONTRON E-88," "BONTRON E-304" (hereinabove manufactured by Orient Chemical Industries Co., Ltd.), "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.), and the like; copper phthalocyanine dyes; quaternary ammonium salts, for example, "COPY CHARGE NX VP434" (manufactured by Clariant, Ltd.), nitroimidazole derivatives, and the like; organometallic compounds and the like.

[0081] The content of the charge control agent is, based on 100 parts by mass of the resin binder, preferably 0.01 parts by mass or more, and more preferably 0.2 parts by mass or more, and the content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, from the viewpoint of charge stability of the toner.

[0082] The toner may be a toner obtained by any of the conventionally known methods such as a melt-kneading method, an emulsion aggregation method, and a suspension polymerization method, or a toner having a core-shell structure, and a pulverized toner produced by the melt-kneading method is preferred, from the viewpoint of charge stability. In a case of a pulverized toner produced by a melt-kneading method, for example, a resin binder containing the crystalline polyester resin C and the amorphous polyester resin A can be homogeneously mixed with a mixer such as a Henschel mixer optionally together with a raw material such as a colorant, a releasing agent, and a charge control agent, thereafter melt-kneading the mixture with a closed kneader, a single-screw or twin-screw extruder, an open-roller type kneader or the like, cooling, pulverizing, and classifying the product, to produce a toner.

[0083] In the toner of the present invention, an external additive is preferably used, for the purpose of improving transferability. The external additive includes fine inorganic particles of silica, alumina, titania, zirconia, tin oxide, zinc oxide, and the like, and fine organic particles of resin particles such as fine melamine resin particles and fine polytetrafluoroethylene resin particles. Two or more kinds of the external additives may be used in combination. Among them, silica is preferred, and a hydrophobic silica that is hydrophobically treated is more preferred, from the viewpoint of transferability of the toner.

[0084] The hydrophobically treating agent for hydrophobically treating the surface of silica particles includes hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), a cyclic silazane, a silicone oil, an aminosilane, octyltriethoxysilane (OTES), methyltriethoxysilane, and the like.

[0085] The average particle size of the external additive is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 15 nm or more, and the average particle size is preferably 250 nm or less, more preferably 200 nm or less, and even more preferably 90 nm or less, from the viewpoints of chargeability, flowability, and transferability of the toner.

[0086] The externally adding treatment by mixing the toner particle and the external additive can be carried out according to a conventional method, and the treatment can use a mixer such as a Henschel mixer.

[0087] The content of the external additive is, based on 100 parts by mass of the toner particle before the treatment with the external additive, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, and the content is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less, from the viewpoints of chargeability, flowability, and transferability of the toner.

[0088] The volume-median particle size D 50 of the toner of the present invention is preferably 3 µm or more, and more preferably 4 µm or more, and the volume-median particle size D 50 is preferably 15 µm or less, and more preferably 10 µm or less. Here, the volume-median particle size D 50 as used herein means a particle size of which cumulative volume frequency calculated on a volume percentage is 50% counted from the smaller particle sizes. Also, in a case where the toner is treated with the external additive, the volume-median particle size of the toner is regarded as a volume-median particle size of the toner particles before the treatment with the external additive.

[0089] The toner of the present invention can be directly used as a toner for monocomponent development, or mixed with a carrier to be used as a two-component developer, and the toner can be used in an image-forming device in a monocomponent development manner or a two-component development manner, respectively.

[0090] With respect to the embodiments described above, the present invention further discloses the following toners for electrostatic image development. <1> A toner for electrostatic image development containing a crystalline polyester resin C and an amorphous polyester resin A, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing ethylene glycol in an amount of 70% by mol or more and a carboxylic acid component containing an aliphatic dicarboxylic acid compound, the alcohol component and / or the carboxylic acid component contains a monofunctional monomer, and the amorphous polyester resin A is a polycondensate of an alcohol component and a carboxylic acid component and a polyethylene terephthalate. <2> The toner for electrostatic image development according to the above <1>, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing ethylene glycol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound. <3> The toner for electrostatic image development according to the above <2>, wherein the content of the ethylene glycol is preferably 80% by mol or more, more preferably 90% by mol or more, and even more preferably 95% by mol or more, and 100% by mol or less in the alcohol component, and in a case where the alcohol component contains monoalcohol, the content is preferably 98% by mol or less, and more preferably 95% by mol or less in the alcohol component. <4> The toner for electrostatic image development according to any one of the above <1> to <3>, wherein in the crystalline polyester resin C, the number of carbon atoms of the aliphatic dicarboxylic acid compound is 4 or more, preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more, and 16 or less, and preferably 14 or less. <5> The toner for electrostatic image development according to any one of the above <1> to <4>, wherein in the crystalline polyester resin C, the content of the aliphatic dicarboxylic acid compound is 80% by mol or more, preferably 90% by mol or more, and more preferably 95% by mol or more, and 100% by mol or less in the carboxylic acid component, and in a case where the carboxylic acid component contains monocarboxylic acid compound, the content is preferably 98% by mol or less, and more preferably 95% by mol or less in the carboxylic acid component. <6> The toner for electrostatic image development according to any one of the above <1> to <5>, wherein in the crystalline polyester resin C, the monofunctional monomer contains an aliphatic monocarboxylic acid compound and / or an aliphatic monoalcohol. <7> The toner for electrostatic image development according to the above <6>, wherein the number of carbon atoms of the aliphatic monoalcohol is 6 or more, preferably 9 or more, more preferably 10 or more, and even more preferably 12 or more, and 24 or less, preferably 23 or less, and more preferably 22 or less. <8> The toner for electrostatic image development according to the above <6> or <7>, wherein the number of carbon atoms of the aliphatic monocarboxylic acid compound is 6 or more, preferably 9 or more, and more preferably 10 or more, and 24 or less, preferably 23 or less, and more preferably 22 or less. <9> The toner for electrostatic image development according to any one of the above <1> to <5>, wherein in the crystalline polyester resin C, the monofunctional monomer contains an aliphatic monocarboxylic acid compound having 9 or more carbon atoms and 24 or less carbon atoms and / or an aliphatic monoalcohol having carbon atoms of 9 or more carbon atoms and 24 or less carbon atoms. <10> The toner for electrostatic image development according to any one of the above <1> to <9>, wherein in the crystalline polyester resin C, the content of the monofunctional monomer is 2% by mol or more, preferably 3% by mol or more, and more preferably 5% by mol or more, and 30% by mol or less, preferably 25% by mol or less, and more preferably 20% by mol or less in a total amount of the alcohol component and the carboxylic acid component. <11> The toner for electrostatic image development according to any one of the above <1> to <10>, wherein the softening point of the crystalline polyester resin C is 50°C or more, preferably 65°C or more, and more preferably 70°C or more, and 120°C or less, and preferably 110°C or less. <12> The toner for electrostatic image development according to any one of the above <1> to <11>, wherein the melting point of the crystalline polyester resin C is 60°C or more, and preferably 70°C or more, and 130°C or less, and preferably 120°C or less. <13> The toner for electrostatic image development according to any one of the above <1> to <12>, wherein the content of the crystalline polyester resin C is 3% by mass or more, preferably 5% by mass or more, and more preferably 8% by mass or more, and 30% by mass or less, preferably 25% by mass or less, and more preferably 20% by mass or less in a total amount of the crystalline polyester resin C and the amorphous polyester resin A. <14> The toner for electrostatic image development according to any one of the above <1> to <13>, wherein in an amorphous polyester resin A, the alcohol component contains an aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms. <15> The toner for electrostatic image development according to the above <14>, wherein the aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms contains at least one kind selected from the group consisting of 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol, and preferably contains neopentyl glycol. <16> The toner for electrostatic image development according to the above <14> or <15>, wherein the content of the aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms is 30% by mol or more, preferably 40% by mol or more, and more preferably 50% by mol or more, and 100% by mol or less in the alcohol component, and in a case where the alcohol component contains trihydric or higher polyhydric alcohol, the content is preferably 98% by mol or less, and more preferably 90% by mol or less in the alcohol component. <17> The toner for electrostatic image development according to any one of the above <1> to <16>, wherein the polyethylene terephthalate is a polyethylene terephthalate having a low IV value, the IV value of the polyethylene terephthalate is 0.40 or more, preferably 0.45 or more, more preferably 0.50 or more, and even more preferably 0.55 or more, and 0.85 or less, preferably 0.80 or less, more preferably 0.75 or less, even more preferably 0.70 or less, and even more preferably 0.65 or less. <18> The toner for electrostatic image development according to the above <17>, wherein the content of the polyethylene terephthalate having a low IV value is 90% by mass or more, preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably 100% by mass in a total amount of the polyethylene terephthalate subjected to the polycondensation. <19> The toner for electrostatic image development according to any one of the above <1> to <18>, wherein in the amorphous polyester resin A, the content of the polyethylene terephthalate is 5% by mol or more, preferably 10% by mol or more, more preferably 15% by mol or more, and even more preferably 20% by mol or more, and 75% by mol or less, preferably 70% by mol or less, and more preferably 65% by mol or less in a total amount of the alcohol component, the carboxylic acid component and the polyethylene terephthalate as one mole of a unit of terephthalic acid-ethylene glycol. <20> The toner for electrostatic image development according to any one of the above <1> to <19>, wherein the softening point of the amorphous polyester resin A is 70°C or more, preferably 90°C or more, and more preferably 100°C or more, and 170°C or less, preferably 160°C or less, and more preferably 150°C or less. <21> The toner for electrostatic image development according to any one of the above <1> to <20>, wherein the amorphous polyester resin A contains amorphous resins having different softening points, the difference of the softening points of the amorphous resins is 10°C or more, and preferably 20°C or more, and 60°C or less, and preferably 40°C or less. <22> The toner for electrostatic image development according to the above <21>, wherein the softening point of the amorphous resin having higher softening point is 100°C or more, preferably 110°C or more, and more preferably 120°C or more, and 170°C or less, preferably 160°C or less, and more preferably 150°C or less. <23> The toner for electrostatic image development according to the above <21> or <22>, wherein the softening point of the amorphous resin having lower softening point is 70°C or more, preferably 90°C or more, and more preferably 100°C or more, and 130°C or less, preferably 125°C or less, and more preferably 120°C or less. <24> The toner for electrostatic image development according to any one of the above <21> to <23>, wherein the mass ratio of an amorphous resin having higher softening point (rein AH) to an amorphous resin having lower softening point (resin AL), resin AH / resin AL is 10 / 90 or more, preferably 20 / 80 or more, and more preferably 30 / 70 or more, and 90 / 10 or less, preferably 80 / 20 or less, and more preferably 75 / 25 or less. <25> The toner for electrostatic image development according to any one of the above <1> to <24>, wherein the glass transition temperature of the amorphous polyester resin A is 40°C or more, and preferably 50°C or more, and 80°C or less, and preferably 70°C or less. <26> The toner for electrostatic image development according to any one of the above <1> to <25>, wherein the content of the amorphous polyester resin A is 70% by mass or more, preferably 75% by mass or more, and more preferably 80% by mass or more, and 97% by mass or less, preferably 95% by mass or less, and more preferably 92% by mass or less in a total amount of the crystalline polyester resin C and the amorphous polyester resin A. <27> The toner for electrostatic image development according to any one of the above <1> to <26>, wherein the mass ratio of the crystalline polyester resin C to the amorphous polyester resin A, crystalline polyester resin C / amorphous polyester resin A is 3 / 97 or more, preferably 5 / 95 or more, and more preferably 8 / 92 or more, and 30 / 70 or less, preferably 25 / 75 or less, and more preferably 20 / 80 or less. <28> The toner for electrostatic image development according to any one of the above <1> to <27>, wherein the toner contains a crystalline polyester resin C and an amorphous polyester resin A as a resin binder, a total content of the crystalline polyester resin C and the amorphous polyester resin A is 70% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass in the resin binder. <29> The toner for electrostatic image development according to the above <28>, wherein the content of the resin binder is 60% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, and less than 100% by mass, preferably 98% by mass or less, and more preferably 95% by mass or less in the toner. <30> The toner for electrostatic image development any one of the above <1> to <29>, wherein the toner is a pulverized toner.

[0091] Hereinafter, the present invention will be described hereinbelow more specifically by showing Examples, without intending to limit the scope of the present invention to the following Examples. The physical properties of resins and the like can be measured according to the following methods.[IV value of PET]

[0092] A sample is dissolved in a 60 / 40 mass ratio mixed solvent of phenol / tetrachloroethane at a concentration of 4 g / L, and the solution is subjected to a measurement with Ubbelohde viscometer, and the value can be obtained by the following formula. IV = − 1 + 1 + 4 kη / 2 kC , wherein k = 0.33, and C = 0.004 g / mL, and η = (t 1 / t 0 ) - 1, wherein t 0 is the number of seconds of dropping only the solvent, and t 1 is the number of seconds of a dropping sample solution.[Softening Point of Resin]

[0093] Using a flow tester "CFT-500D," manufactured by Shimadzu Corporation, a 1 g of sample is extruded through a nozzle having a diameter of 1 mm and a length of 1 mm with applying a load of 1.96 MPa thereto with a plunger, while heating the sample at a heating rate of 6°C / min. The softening point refers to a temperature at which half of the sample flows out, when plotting a downward movement of the plunger of the flow tester against temperature.[Temperature of Maximum Endothermic Peak of Resin]

[0094] Using a differential scanning calorimeter "Q-100," manufactured by TA Instruments Japan Inc., 0.01 to 0.02 g of sample is weighed out in an aluminum pan, and cooled from room temperature (25°C) to 0°C at a cooling rate of 10°C / min, and kept at 0°C for one minute. Thereafter, the temperature of the sample is raised at a heating rate of 10°C / min to take measurements. Of the endothermic peaks observed, a temperature of the peak having the largest peak area is defined as a temperature of the maximum endothermic peak. In a crystalline resin, the temperature of the maximum endothermic peak is defined as a melting point.[Glass Transition Temperature of Resin]

[0095] Using a differential scanning calorimeter "Q-100," manufactured by TA Instruments Japan Inc., 0.01 to 0.02 g of sample is weighed out in an aluminum pan, heated to 200°C, and cooled from that temperature to 0°C at a cooling rate of 10°C / min. Next, the sample is heated at a rate of 10°C / min to take measurements of endothermic peaks. A temperature at an intersection of the extension of the baseline of equal to or lower than the temperature of the maximum endothermic peak and the tangential line showing the maximum inclination between the kick-off of the peak and the top of the peak in the above measurement is defined as a glass transition temperature.

[0096] [Acid Value of Resin]

[0097] The acid value is determined by a method according to JIS K0070:1992 except that only a determination solvent is changed from a mixed solvent of ethanol and ether as prescribed in JIS K0070 to a mixed solvent of acetone and toluene in a volume ratio of acetone : toluene = 1:1 in an amorphous resin, and to a mixed solvent of chloroform and dimethyl formamide in a volume ratio of chloroform : dimethyl formamide = 7:3 in a crystalline resin, respectively.[Melting Point of Releasing Agent]

[0098] Using a differential scanning calorimeter "Q-100," manufactured by TA Instruments Japan Inc., 0.02 g of sample is weighed out in an aluminum pan, heated to 200°C, and cooled from 200°C to 0°C at a cooling rate of 10°C / min. Next, the temperature of the sample is raised at a heating rate of 10°C / min to measure calory. A temperature of the maximum endothermic peak is defined as a melting point.[Volume-Median Particle Size and CV Value of Resin Particles, Colorant Particles and Releasing Agent Particles]

[0099] (1) Measuring Apparatus: Laser Diffraction Particle Size Analyzer, LA-920, manufactured by HORIBA, Ltd. (2) Measurement Conditions: Sample dispersion is taken in a cell for measurement, distilled water is added thereto, and volume-median particle size D 50 and volume-mean particle size are measured at a temperature in which an absorbance is within a proper range. In addition, the CV value is calculated according to the following formula. [Solid Content Concentration of Resin Dispersion, Colorant Dispersion and Releasing Agent Dispersion]

[0100] Five grams of measurement sample is dried at 150°C of a drytemperature, under a condition of measurement mode 96 (monitoring time: 2.5 minutes, fluctuation range: 0.05%) using Infrared Moisture Tester, "FD-230," manufactured by Kett Electric Laboratory Co. Ltd., and the water content (% by mass) of a dispersion is measured. The solid content concentration is calculated according to the following formula. [Volume-Median Particle Size of Aggregated Particles]

[0101] Measuring Apparatus: "Coulter Multisizer (registered trademark) III," manufactured by Beckman Coulter, Inc. Aperture Diameter: 50 µm Analyzing Software: "Multisizer (registered trademark) III Ver. 3.51," manufactured by Beckman Coulter, Inc. Electrolytic Solution: "Isotone (registered trademark) II," manufactured by Beckman Coulter, Inc. Measurement Conditions: The sample dispersion is added to 100 mL of the above electrolytic solution to adjust to a concentration at which particle sizes of 30,000 particles can be measured in 20 seconds, and thereafter the 30,000 particles are measured, and a volume-median particle size D 50 is obtained from the particle size distribution. [Average Particle Size of External Additive]

[0102] The average particle size refers to a number-average particle size, which is defined as a number-average of particle sizes (average of length and breadth) determined for 500 particles from a photograph taken with a scanning electron microscope (SEM).[Volume-Median Particle Size D 50 of Toner]

[0103] Measuring Apparatus: "Coulter Multisizer (registered trademark) III," manufactured by Beckman Coulter, Inc. Aperture Diameter: 50 µm Analyzing Software: "Multisizer (registered trademark) III Ver. 3.51," manufactured by Beckman Coulter, Inc. Electrolytic Solution: "Isotone (registered trademark) II," manufactured by Beckman Coulter, Inc. Dispersion: polyoxyethylene lauryl ether, "EMULGEN (registered trademark) 109P," manufactured by Kao Corporation, HLB (Griffin) = 13.6, is dissolved in the electrolytic solution to adjust to a concentration of 5% by mass to provide a dispersion. Dispersion Conditions: Ten milligrams of a measurement sample is added to 5 mL of the above dispersion, and the mixture is dispersed for 1 minute with an ultrasonic disperser (name of machine: US-1, manufactured by SND Co., Ltd., output: 80 W). Thereafter, 25 mL of the above electrolytic solution is added to the dispersion, and further dispersed with the ultrasonic disperser for 1 minute, to prepare a sample dispersion. Measurement Conditions: The above sample dispersion is added to 100 mL of the above electrolytic solution to adjust to a concentration at which particle sizes of 30,000 particles can be measured in 20 seconds, and thereafter the 30,000 particles are measured, and a volume-median particle size D 50 is obtained from the particle size distribution. [Circularity of Toner]

[0104] A circularity of toner particles is measured according to the following condition. Measuring Apparatus: Flow Particle Image Analyzer "FPIA-3000," manufactured by SYSMEX CORPORATION Preparation of Dispersion: A dispersion of toner particles is diluted with deionized water to have a solid content concentration of from 0.001 to 0.05% by mass, to prepare a dispersion. Measuring Mode: HPF measuring mode Production Example 1 of Resin

[0105] A 10-L four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple was charged with an alcohol component, a carboxylic acid component, PET, an esterification catalyst and a promoter, as listed in Tables 1 to 6, and the content was maintained for one hour at 180°C under nitrogen atmosphere. Then, the content was heated from 180°C to 235°C at a rate of 10°C / h, and further subjected to polycondensation for 5 hours at 235°C. Thereafter, the contents were cooled to 210°C, and reaction was carried out under a reduced pressure of 10 kPa until softening points as listed in Tables 1 to 6 were reached, to provide amorphous polyester resins (Resins AH1 to AH7, AH12, AH13, Resins AL1 to AL6, AL11, and AL12). The physical properties are shown in Tables 1 to 6.Production Example 2 of Resin

[0106] A 10-L four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple was charged with an alcohol component, a carboxylic acid component other than trimellitic anhydride, PET, an esterification catalyst and a promoter, as listed in Tables 2 and 3, and the content was heated to 235°C under a nitrogen atmosphere. Then the content was subjected to polycondensation for 6 hours at 235°C. Thereafter, the content was cooled to 210°C, and trimellitic anhydride listed in Tables 2 and 3 was added thereto, and the mixture was allowed to react for one hour at 210°C. Further, the mixture was reacted under a reduced pressure of 10 kPa at 210°C until the softening points as listed in Tables 2 and 3 were reached, to provide amorphous polyester resins (Resins AH8, AH11, Resin AH14). The physical properties are shown in Tables 2 and 3.Production Example 3 of Resin

[0107] A 5-L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube provided with a fractionating column through which water heated at 98°C was flowed, a stirrer and a thermocouple was charged with an alcohol component, a carboxylic acid component, and an esterification catalyst, and a promoter, as listed in Tables 2 and 5, and the content was maintained for one hour at 180°C under nitrogen atmosphere. Then the content was heated from 180°C to 235°C at a rate of 10°C / h, and the content was subjected to polycondensation for 5 hours at 235°C. Thereafter, the content was cooled to 210°C, and reaction was carried out under a reduced pressure of 10 kPa at 210°C until the softening points as listed in Tables 2 and 5 were reached, to provide amorphous polyester resins (Resins AH9 to AH10, AL8 to AL9). The physical properties are shown in Tables 2 and 5.Production Example 4 of Resin

[0108] A 10-L four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple was charged with an alcohol component, a carboxylic acid component, PET, an esterification catalyst, and a promoter, as listed in Tables 5 and 6, and the content was heated to 235°C under nitrogen atmosphere, and then the content was subjected to polycondensation for 6 hours at 235°C. Thereafter, the content was cooled to 210°C, and reaction was carried out under a reduced pressure of 10 kPa until the softening points as listed in Tables 5 and 6 were reached, to provide amorphous polyester resins (Resins AL7, AL10 and AL13). The physical properties are shown in Tables 5 and 6.

[0109] [Table 1] Table 1Resin AH 1Resin AH2Resin AH3Resin AH4Resin AH5ratiogratiogratiogratiogratiogAlcohol componentNeopentyl glycol36.9117836.9117873.7209258172916551Glycerol10.529810.529810.526410.527710.5320Carboxylic acid componentTerephthalic acid47.4241747.4241784.2381668.5326026.51456PETVirgin PET 1)< 52.63107----15.882831.5173473.54673Recycled PET 2)< ----52.63107------------Esterification catalystTin(II) 2-ethylhexanoate0.5350.5350.5350.5350.535PromoterGallic acid0.053.50.053.50.053.50.053.50.053.5PET content, % by mol363691958Physical propertiesSoftening point, °C132133134133137Temperature of the maximum endothermic peak, °C5960636157Crystallinity index2.22.22.12.22.4Glass transition temperature, °C5758615955Acid value, mgKOH / g1716161713Note 1) The ratio of the alcohol component, the carboxylic acid component and the PET shows a molar ratio, based on 100 moles of the alcohol component (including an ethylene glycol unit contained in PET). However, the PET is defined as 1 mole of (Ethylene glycol-Terephthalic acid) unit. Note 2) The ratio of the esterification catalyst and the promoter shows a mass ratio, based on 100 parts by mass of a total of the alcohol component, the carboxylic acid component and the PET. Note 3) PET content shows a content, % by mole in a total amount of the alcohol component, the carboxylic acid component and the PET. 1) Virgin PET: RAMAPET L1, manufactured by Indorama Ventures, IV value: 0.60 2) Recycled PET: UK-31, manufactured by Utsumi Recycle Systems Inc, IV value: 0.67

[0110] [Table 2] Table 2Resin AH6Resin AH7Resin AH8Resin AH9Resin AH10ratiogratiogratio gratio gratiogAlcohol componentBPA-PO(2.2) 1)< --------251784--------BPA-EO 2)< --------251657--------1,2-Propanediol36.9903--------89.51954----Neopentyl glycol----36.91157--------36.91089Ethylene glycol----------------52.6926Glycerol10.5311--------10.527810.5274Trimethylolpropane----10.5424------------Carboxylic acid componentTerephthalic acid47.4253447.4237330101510047681004711Trimellitic anhydride--------15587--------PETVirgin PET 3)< 52.6325252.63046501957--------Esterification catalystTin(II) 2-ethylhexanoate0.5350.5350.5350.5350.535PromoterGallic acid0.053.50.053.50.053.50.053.50.053.5PET content, % by mol36363400Physical propertiesSoftening point, °C134135134132133Temperature of the maximum endothermic peak, °C6058616460Crystallinity index2.22.32.22.12.2Glass transition temperature, °C5856606258Acid value, mgKOH / g1615161717Note 1) The ratio of the alcohol component, the carboxylic acid component and the PET shows a molar ratio, based on 100 moles of the alcohol component (including an ethylene glycol unit contained in PET). However, the PET is defined as 1 mole of (Ethylene glycol-Terephthalic acid) unit. Note 2) The ratio of the esterification catalyst and the promoter shows a mass ratio, based on 100 parts by mass of a total of the alcohol component, the carboxylic acid component and the PET. Note 3) The PET content shows a content, % by mole in a total amount of the alcohol component, the carboxylic acid component and the PET. 1) Polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 2) Polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 3) Virgin PET: RAMAPET L1, manufactured by Indorama Ventures, IV value: 0.60

[0111] [Table 3] Table 3Resin AH11Resin AH12Resin AH13Resin AH14ratiogratiogratiogratio gAlcohol componentBPA-PO(3.0) 1)< 503746--------503746Neopentyl glycol----36.9117836.91178----Glycerol----10.529810.5298----Carboxylic acid componentTerephthalic acid3092847.4241747.4241730928Trimellitic anhydride15537--------15537PETVirgin PET 2])< 50178952.6310752.63107----Recycled PET 3)< ------------501789Esterification catalystTin(II) 2-ethylhexanoate0.535------------Titanium diisopropoxy bis(triethanolaminate)----0.535----0.535Titanium dihydroxy bis(triethanolaminate)--------0.535----PromoterGallic acid0.053.50.053.50.053.50.053.5PET content, % by mol34363634Physical propertiesSoftening point, °C139131133140Temperature of the maximum endothermic peak, °C55596055Crystallinity index2.52.22.22.5Glass transition temperature, °C53575853Acid value, mgKOH / g1018169Note 1) The ratio of the alcohol component, the carboxylic acid component and the PET shows a molar ratio based on 100 moles of the alcohol component (including an ethylene glycol unit contained in PET). However, the PET is defined as 1 mole of (Ethylene glycol-Terephthalic acid) unit. Note 2) The ratio of the esterification catalyst and the promoter shows a mass ratio, based on 100 parts by mass of a total of the alcohol component, the carboxylic acid component and the PET. Note 3) The PET content shows a content, % by mole in a total amount of the alcohol component, the carboxylic acid component and the PET. 1) Polyoxypropylene(3.0)-2,2-bis(4-hydroxyphenyl)propane 2) Virgin PET: RAMAPET L1, manufactured by Indorama Ventures, IV value: 0.60 3) Recycled PET: UK-31, manufactured by Utsumi Recycle Systems Inc, IV value: 0.67

[0112] [Table 4] Table 4Resin AL1Resin AL2Resin AL3Resin AL4Resin AL5ratiogratiogratiogratiogratiogAlcohol componentNeopentyl glycol50169850169885256070221620762Carboxylic acid componentTerephthalic acid40216840216875360660303110608PETVirgin PET 1)< 503134----15834301753805629Recycled PET 2)< ----503134----------Esterification catalystTin(II) 2-ethylhexanoate0.5350.5350.5350.5350.535PromoterGallic acid0.053.50.053.50.053.50.053.50.053.5PET content, % by mol363691973Physical propertiesSoftening point, °C105104104105109Temperature of the maximum endothermic peak, °C5857616057Crystallinity index1.81.81.71.81.9Glass transition temperature, °C5554595855Acid value, mgKOH / g111213129Note 1) The ratio of the alcohol component, the carboxylic acid component and the PET shows a molar ratio based on 100 moles of the alcohol component (including an ethylene glycol unit contained in PET). However, the PET is defined as 1 mole of (Ethylene glycol-Terephthalic acid) unit. Note 2) The ratio of the esterification catalyst and the promoter shows a mass ratio, based on 100 parts by mass of a total of the alcohol component, the carboxylic acid component and the PET. Note 3) The PET content shows a content, % by mole in a total amount of the alcohol component, the carboxylic acid component and the PET. 1) Virgin PET: RAMAPET L1, manufactured by Indorama Ventures, IV value: 0.60 2) Recycled PET: UK-31, manufactured by Utsumi Recycle Systems Inc, IV value: 0.67

[0113] [Table 5] Table 5Resin AL6Resin AL7Resin AL8Resin AL9ratiogratio gratio gratio gAlcohol componentBPA-PO(2.2) 1)< ----251850--------BPA-EO 2)< ----251716--------1,2-Propanediol501327----1002360----Neopentyl glycol------------501566Ethylene glycol------------50934Carboxylic acid componentTerephthalic acid402320401404904640904500PETVirgin PET 3)< 503353502030--------Esterification catalystTin(II) 2-ethylhexanoate0.5350.5350.5350.535PromoterGallic acid0.053.50.053.50.053.50.053.5PET content, % by mol363600Physical propertiesSoftening point, °C103105103105Temperature of the maximum endothermic peak, °C56576059Crystallinity index1.81.81.71.8Glass transition temperature, °C54555757Acid value, mgKOH / g9101210Note 1) The ratio of the alcohol component, the carboxylic acid component and the PET shows a molar ratio, based on 100 moles of the alcohol component (including an ethylene glycol unit contained in PET). However, the PET is defined as 1 mole of (Ethylene glycol-Terephthalic acid) unit. Note 2) The ratio of the esterification catalyst and the promoter shows a mass ratio, based on 100 parts by mass of a total of the alcohol component, the carboxylic acid component and the PET. Note 3) The PET content shows a content, % by mole in a total amount of the alcohol component, the carboxylic acid component and the PET. 1) Polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 2) Polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 3) Virgin PET: RAMAPET L1, manufactured by Indorama Ventures, IV value: 0.60

[0114] [Table 6] Table 6Resin AL10Resin AL11Resin AL12Resin AL13ratio gratio | gratio gratiogAlcohol componentBPA-PO(3.0) 1)< 503872--------503872Neopentyl glycol----501698501698----Carboxylic acid componentTerephthalic acid401279402168402168401279PETVirgin PET 2)< 501849503134503134----Recycled PET 3)< ------------501849Esterificatio n catalystTin(II) 2-ethylhexanoate0.535------------Titanium diisopropoxy bis(triethanolaminate)----0.535----0.535Titanium dihydroxy bis(triethanolaminate)--------0.535----PromoterGallic acid0.053.50.053.50.053.50.053.5PET content, % by mol36363636Physical propertiesSoftening point, °C109104106108Temperature of the maximum endothermic peak, °C52585952Crystallinity index2.11.81.82.1Glass transition temperature, °C50555650Acid value, mgKOH / g61097Note 1) The ratio of the alcohol component, the carboxylic acid component and the PET shows a molar ratio, based on 100 moles of the alcohol component (including an ethylene glycol unit contained in PET). However, the PET is defined as 1 mole of (Ethylene glycol-Terephthalic acid) unit. Note 2) The ratio of the esterification catalyst and the promoter shows a mass ratio, based on 100 parts by mass of a total of the alcohol component, the carboxylic acid component and the PET. Note 3) The PET content shows a content, % by mole in a total amount of the alcohol component, the carboxylic acid component and the PET. 1) Polyoxypropylene(3.0)-2,2-bis(4-hydroxyphenyl)propane 2) Virgin PET: RAMAPET L1, manufactured by Indorama Ventures, IV value: 0.60 3) Recycled PET: UK-31, manufactured by Utsumi Recycle Systems Inc, IV value: 0.67 Production Example 5 of Resin

[0115] A 10-L four-necked flask equipped with a thermometer, a stainless stirrer bar, a flow condenser and a nitrogen inlet tube was charged with an alcohol component and a carboxylic acid component as listed in Tables 7 and 8, the content was heated to 200°C, over 8 hours in a mantle heater under nitrogen atmosphere. Thereafter, an esterification catalyst, as listed in Table 7 and 8 was added thereto, and reaction was carried out at 8.0 kPa until the softening points as listed in Tables 7 and 8 were reached, to provide crystalline polyester resins (resins C1 to C11). The physical properties are shown in Tables 7 and 8.

[0116] [Table 7] Table 7Resin C1Resin C2Resin C3Resin C4Resin C5Resin C6molar ratiogmolar ratiogmolar ratiogmolar ratiogmolar ratiogmolar ratiogAlcohol componentEthylene glycol (EG)10014591001595100134595135410015471001502Stearyl alcohol------------10621--------Carboxylic acid componentSebacic acid----904675----------------Dodecanedioic acid904872--------955025905164905014Tetradecanedioic acid--------905039------------Caproic acid----------------10289----Lauric acid--------------------10484Stearic acid106691073010616------------Esterification catalystTin(II) 2-ethylhexanoate14g14g14g14g14g14gPhysical propertiesSoftening point, °C847589838484Melting point, °C837488828283Crystallinity index1.01.01.01.01.01.0Acid value, mgKOH / g777776

[0117] [Table 8] Table 8Resin C7Resin C8Resin C9Resin C10Resin C11molar ratiogmolar ratiogmolar ratiogmolar ratiogmolar ratiogAlcohol componentEthylene glycol (EG)1001432----1001547100145910014181,6-Hexanediol (1,6HD)----1002337------------Carboxylic acid componentDodecanedioic acid92.54781904100955453854600804210Lauric acid------------20941301372Stearic acid----10563------------Behenic acid5787----------------Esterification catalystTin(II) 2-ethylhexanoate14g14g14g14g14gPhysical propertiesSoftening point, °C8471868279Melting point, °C8370848178Crystallinity index1.01.01.01.01.0Acid value, mgKOH / g77788 Examples 1 to 17 and 20 to 25, and Comparative Examples 1 to 4[Melt-Kneading Method]

[0118] One hundred parts by mass of a resin binder as listed in Table 9, 5 parts by mass of a colorant "ECB-301," manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., Phthalocyanine Blue, P.B. 15:3, 3 parts by mass of a releasing agent "Carnauba Wax C1," manufactured by S. KATO & CO., melting point: 83°C, and 0.5 parts by mass of a negatively chargeable charge control agent "BONTRON E-304," manufactured by Orient Chemical Industries Co., Ltd. were mixed with a Henschel mixer.

[0119] The resulting mixture was melt-kneaded at a screw rotational speed of 200 r / min, at a barrel setting temperature of 100°C with a same direction revolution twin-screw extruder having a full length of kneading portion of 1560 mm, a screw diameter of 42 mm and a barrel inner diameter of 43 mm, to provide a melt-kneaded mixture. The feeding rate of the mixture was 20 kg / h, and the average residence time was about 18 seconds.

[0120] The resulting melt-kneaded mixture was cooled and roughly pulverized, and then pulverized with a jet mill, and classified with an air flow type classifier, manufactured by Nippon Pneumatic Mfg. Co., Ltd., to provide toner particles having a volume-median particle size D 50 of 7.0 µm.

[0121] One hundred parts by mass of the resulting toner particles were mixed with 1.0 parts by mass of a hydrophobic silica "R972," manufactured by NIPPON AEROSIL CO., LTD., hydrophobically treating agent: DMDS, average particle size: 16 nm, and 1.0 parts by mass of a hydrophobic silica "RY-50," manufactured by NIPPON AEROSIL CO., LTD., hydrophobically treating agent: silicone oil, average particle size: 40 nm as external additives with a Henschel mixer, manufactured by NIPPON COKE & ENGINEERING CO.,LTD., at a rotational speed of 3000 r / min (peripheral speed of 32 m / sec) for 3 minutes, to provide each of the toners.Example 18

[0122] A toner was obtained in the same manner as Example 1, except that melt-kneading was carried out using a continuous open-roller type twin-screw kneader "Kneadex," manufactured by NIPPON COKE & ENGINEERING CO.,LTD.. in place of same direction revolution twin-screw extruder. The continuous open-roller type twin-screw kneader had outer diameter of roller: 0.14 m and effective length of roller: 0.8 m, and an operational condition of a rotational speed of a high-rotation roller (front roller) of 75 r / min (a peripheral speed of 33 m / min), a rotational speed of a low-rotation roller (back roller) of 50 r / min (a peripheral speed of 22 m / min), and a gap between the rollers of 0.1 mm. The temperatures of the heating medium and the cooling medium inside the rollers are as follows. The temperature of the high-rotation roller was set at the raw material supplying side to 140°C, and at the kneaded mixture discharging side to 110°C, and a temperature at the low-rotation roller was set at the raw material supplying side to 65°C, and at the kneaded mixture discharging side to 30°C. In addition, the feeding rate of the raw material mixture was 10 kg / h, and the average residence time was about 5 minutes.Example 19 [Emulsion Aggregation Method]<Preparation of Resin Dispersion for Core>

[0123] A 5-L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube was supplied with 600 g of methyl ethyl ketone, and 129 g of Resin AH1 and 21 g of Resin C1 were added thereto at 60°C, and the mixture was dissolved. To the resulting solution, 5% by mass of aqueous sodium hydroxide solution was added such that the solution had a degree of neutralization of 60% by mol against an acid value of a resin, and the solution was stirred for 30 minutes, to provide a mixture. Subsequently, 675 g of deionized water was added to the mixture over 77 minutes. Next, methyl ethyl ketone was distilled off at a temperature of 50°C or less under a reduced pressure while stirring the mixture at 250 r / min, and thereafter, the solid content concentration of the water-based dispersion was measured, the solid content concentration of the water-based dispersion was adjusted to 20% by mass with deionized water, to provide a resin dispersion for a core. Volume-median particle size D 50 of resin particles in the dispersion was 200 nm, and CV value was 24%.<Preparation of Resin Dispersion for Shell>

[0124] A 5-L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube was supplied with 600 g of methyl ethyl ketone, and 150 g of Resin AL1 was added thereto at 60°C, and the mixture was dissolved. To the resulting solution, 5% by mass of aqueous sodium hydroxide solution was added such that the solution had a degree of neutralization of 60% by mol against an acid value of a resin, and the solution was stirred for 30 minutes, to provide a mixture. Subsequently, 675 g of deionized water was added to the mixture over 77 minutes. Next, methyl ethyl ketone and a part of water were distilled off at a temperature of 50°C or less under a reduced pressure while stirring the mixture at 250 r / min, and thereafter, the solid content concentration of the water-based dispersion was measured, the solid content concentration of the water-based dispersion was adjusted to 20% by mass with deionized water, to provide a resin dispersion for a shell. Volume-median particle size D 50 of resin particles in the dispersion was 110 nm, and CV value was 20%.<Preparation of Colorant Dispersion>

[0125] In a 1-L beaker, 116.2 g of a colorant "ECB-301," manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., Phthalocyanine Blue, P.B. 15:3, 154.9 g of anionic surfactant "NEOPELEX (registered trademark) G-15," manufactured by Kao Corporation, 15% by mass of aqueous solution of sodium dodecylbenzenesulfonate and 260 g of deionized water were mixed, and the mixture was dispersed for 3 hours under room temperature with a homogenizer, and thereafter deionized water was added thereto such that the mixture had a solid content concentration of 24% by mass, thereby providing a colorant dispersion. Volume-median particle size D 50 of colorant particles in the dispersion was 118 nm, and CV value was 27%.<Preparation of Releasing Agent Dispersion>

[0126] Fifty grams of Fischer-Tropsch wax, manufactured by NIPPON SEIRO CO., LTD., trade name: FNP0090, melting point: 90°C, 5 g of cationic surfactant, manufactured by Kao Corporation, trade name: SANISOL B50 and 200 g of deionized water were heated to 95°C, and the wax was dispersed using a homogenizer, and thereafter, the dispersed wax was subjected to a dispersion treatment with a pressurized dischargingtype homogenizer, to provide a releasing agent dispersion having a solid content concentration of 20% by mass. Volume-median particle size D 50 of releasing agent particles in the dispersion was 550 nm, and CV value was 26%.<Preparation of Toner Particle>

[0127] In a 3-L four-necked flask equipped with a dehydration tube, a stirrer and a thermocouple, 500 g of the above resin dispersion for a core, 36 g of the above colorant dispersion, 33 g of the above releasing agent dispersion and 3.3 g of 15% by mass of aqueous solution of sodium dodecylbenzenesulfonate, "NEOPELEX G-15," manufactured by Kao Corporation, anionic surfactant, were mixed at 25°C. Next, a solution of which a pH was adjusted to 8.2 by adding 4.8% by mass of aqueous potassium hydroxide solution to an aqueous solution in which 40 g of ammonium sulfate was dissolved in 570 g of deionized water was added dropwise to the resulting mixture over 10 minutes at 25°C, while stirring. Thereafter, the mixture was heated to 62°C, over 2 hours, and the mixture was maintained at 62°C until the volume-median particle size D 50 of the aggregated particles reached 6.9 µm, to provide a dispersion of aggregated particles (I).

[0128] To the resulting dispersion of aggregated particles (1), 215 g of the above resin dispersion for a shell was added dropwise at a rate of 0.6 mL / min (0.6 g / min), while keeping temperature of the dispersion at 62°C, to provide a dispersion of aggregated particles (II). Volume-median particle size D 50 of the aggregated particles (II) was 7.0 µm.

[0129] To the resulting dispersion of aggregated particles (II), an aqueous solution in which 20 g of sodium polyoxyethylene laurylether sulfate, "EMAL E-27C," manufactured by Kao Corporation, anionic surfactant, effective concentration: 27% by mass, 280 g of deionized water and 40 g of aqueous sulfuric acid solution having a concentration of 0.1 mol / L were mixed was added. Thereafter, the mixture was heated to 80°C over 1 hour, and maintained for 30 minutes at 80°C, and then 10 g of aqueous sulfuric acid solution having a concentration of 0.1 mol / L was added thereto, and the mixture was further maintained for 15 minutes at 80°C. Next, 15 g of aqueous sulfuric acid solution having a concentration of 0.1 mol / L was added thereto again, and the mixture was maintained at 80°C until the circularity reached 0.970, thereby providing a dispersion of coalesced particles (core-shell particles) in which aggregated particles were coalesced.

[0130] The resulting dispersion of core-shell particles was cooled to 30°C, the dispersion was subjected to a suction filtration to separate a solid content, and thereafter, the solid content was washed with deionized water at 25°C, and the washed content was subjected to a suction filtration for 2 hours at 25°C. Thereafter, the filtrate was subjected to vacuum drying for 24 hours at 33°C using a vacuum drying oven "DRV622DA," manufactured by ADVANTEC, to provide toner particles. The resulting toner particles had a particle size of 7.0 µm, and circularity of 0.970. Here, the composition ratio (mass ratio) in a resin binder in the resulting toner particles is Resin AHl / Resin AL1 / Resin C1 = 60 / 30 / 10.

[0131] One hundred parts by mass of the resulting toner particles, 1.0 parts by mass of hydrophobic silica "R972," manufactured by NIPPON AEROSIL CO., LTD., hydrophobically treating agent: DMDS, average particle size: 16 nm, and and 1.0 parts by mass of a hydrophobic silica "RY-50," manufactured by NIPPON AEROSIL CO., LTD., hydrophobically treating agent: silicone oil, average particle size: 40 nm as external additives, are mixed for 3 minutes with a Henschel mixer, manufactured by NIPPON COKE & ENGINEERING CO.,LTD., at a rotational speed of 3000 r / min (peripheral speed of 32 m / sec), to provide toners.Test Example 1 [Charge Stability of Toner]

[0132] Under a condition of a temperature of 25°C and relative humidity of 50%, 0.6 g of a toner and 19.4 g of a silicone ferrite carrier, manufactured by KANTO DENKA KOGYO CO., LTD., an average particle size: 90 µm were placed in a 50 mL of polyethylene container, and the content was mixed with a ball mill at 250 r / min, and electric charges of the toner were measured using a Q / M meter, manufactured by EPPING GmbH according to the following method.

[0133] After mixing time of 60 seconds or 600 seconds, a defined amount of a mixture of the toner and the carrier was injected into a cell attached to the Q / M meter, the mixture was allowed to pass through a sieving (formed of stainless steel, twill, wire diameter: 0.0035 mm) having an opening of 32 µm, and only toners were aspirated for 90 seconds. The change of voltage on the carrier which occurred at that time was monitored, and the value of [total electric charge (µC) after 90 seconds / amount (g) of toners aspirated] was defined as electric charges (µC / g). The ratio of the electric charges after 60 seconds of mixing time to the electric charges after 600 seconds of mixing time, i.e. electric charges after 60 seconds of mixing time / electric charges after 600 seconds of mixing time was calculated and the charge stability was evaluated. The result is shown in Table 9. It is shown that the larger the numerical value is, the more excellent the charge stability is.Test Example 2 [Pressurized Storage Property of Toner]

[0134] In a cylindrical container having a radius of 12 mm, 10 g of the toner was placed, a 100 g of weight was loaded thereon from the top side, and the container was pressurized and stored for 24 hours under an environment of 50°C and a relative humidity of 60%. Three of sieve A (opening: 250 µm), sieve B (opening: 150 µm) and sieve C (opening: 75 µm) were overlapped and placed on a powder tester, manufactured by HOSOKAWA MICRON CORPORATION, in this order from the top, and 10 g of the pressurized and stored toner was loaded on the sieve A, and the sieve was vibrated for 60 seconds. Each of the weight WA (g) of toner remaining on the sieve A, the weight WB (g) of toner remaining on the sieve B, and the weight WC (g) of toner remaining on the sieve C was measured, and pressurized storage property was evaluated according to the following evaluation criteria, based on the value (α) calculated according to the following formula. The results are shown in Table 9. It is shown that the closer to 100 the value (α) is, the more excellent the pressurized storage property is. α = 100 − WA + WB × 0.6 + WC × 0.2 / 10 × 100

[0135] [Table 9] Table 9Resin binderProduction methodToner evaluationAmorphous polyester resinCrystalline polyester resinAH / AL / C, mass ratioCharge stabilityPressurized storage abilityHPET Content HLPET Content LPET Content ACAlcohol componentMonofunctional monomerEx. 1Resin AH136Resin AL13636Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8891.8Ex. 2Resin AH136Resin AL13636Resin C2EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8285.6Ex. 3Resin AH136Resin AL13636Resin C3EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8790.2Ex. 4Resin AH136Resin AL13636Resin C4EGStearyl alcohol60 / 30 / 10Melt-kneading (twin screw)0.8790.5Ex. 5Resin AH136Resin AL13636Resin C1EGStearic acid62.5 / 32.5 / 5Melt-kneading (twin screw)0.7988.7Ex. 6Resin AH 136Resin AL13636Resin C 1EGStearic acid57.5 / 27.5 / 15Melt-kneading (twin screw)0.8790.5Ex. 7Resin AH 136Resin AL13636Resin C1EGStearic acid52.5 / 22.5 / 25Melt-kneading (twin screw)0.8588.5Ex. 8Resin AH136Resin AL13636Resin C5EGCaproic acid60 / 30 / 10Melt-kneading (twin screw)0.7785.8Ex. 9Resin AH 136Resin AL13636Resin C6EGLauric acid60 / 30 / 10Melt-kneading (twin screw)0.8486.7Ex. 10Resin AHI36Resin AL13636Resin C7EGBehenic acid60 / 30 / 10Melt-kneading (twin screw)0.8889.5Ex. 11Resin AH236Resin AL23636Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8791.1Ex. 12Resin AH39Resin AL399Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8580.5Ex. 13Resin AH419Resin AL41919Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8685.6Ex. 14Resin AH558Resin AL57363Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8687.4Ex. 15Resin AH636Resin AL63636Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8787.7Ex. 16Resin AH736Resin AL13636Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8490.5Ex. 17Resin AH834Resin AL73635Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8180.6Ex. 18Resin AH136Resin AL13636Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (open roll)0.8389.6Ex. 19Resin AH 136Resin AL 13636Resin C 1EGStearic acid60 / 30 / 10Emulsification aggregation0.8485.5Ex. 20Resin AH 136Resin AL13636Resin C10EGLauric acid60 / 30 / 10Melt-kneading (twin screw)0.8688.8Ex. 21Resin AH136Resin AL13636Resin C11EGLauric acid60 / 30 / 10Melt-kneading (twin screw)0.8286.5Ex. 22Resin AH1134Resin AL103635Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8080.8Ex. 23Resin AH1236Resin AL113636Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8691.2Ex. 24Resin AH1336Resin AL123636Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8790.9Ex. 25Resin AH1434Resin AL133635Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8180.2Comp Ex. 1Resin AH90Resin AL800Resin C 1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.7252.4Comp Ex. 2Resin AH100Resin AL900Resin C1EGStearic acid60 / 30 / 10Melt-kneading (twin screw)0.7455.6Comp Ex. 3Resin AH136Resin AL13636Resin C81,6HDStearic acid60 / 30 / 10Melt-kneading (twin screw)0.8043.2Comp Ex. 4Resin AH136Resin AL13636Resin C9EG--60 / 30 / 10Melt-kneading (twin screw)0.6674.5Note) PET content A is a weighted mean value of PET content H (% by mol) and PET content L (% by mol).

[0136] From the above results, it is found that both of charge stability and pressurized storage property are good in Examples 1 to 25.

[0137] On the other hand, toners of Comparative Examples 1 and 2 containing the amorphous polyester resin without using a PET are insufficient in both of charge stability and pressurized storage property, and particularly, it is found from Comparative Example 2 that the use of ethylene glycol and terephthalic acid which are monomer components of the PET is not effective, and the use of a PET is important. In addition, as to the crystalline polyester resin, the decrease of the pressurized storage property in Comparative Example 3 not using ethylene glycol and the decrease of charge stability in Comparative Example 4 not using a monofunctional monomer are respectively remarkable.

[0138] The toner for electrostatic image development of the present invention is suitably used in the development and the like of latent images formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims

1. A toner for electrostatic image development comprising a crystalline polyester resin C and an amorphous polyester resin A, wherein the crystalline polyester resin C is a polycondensate of an alcohol component comprising ethylene glycol in an amount of 70% by mol or more and a carboxylic acid component comprising an aliphatic dicarboxylic acid compound, the alcohol component and / or the carboxylic acid component comprises a monofunctional monomer, and the amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component and a polyethylene terephthalate.

2. The toner for electrostatic image development according to claim 1, wherein the content of the polyethylene terephthalate is 5% by mol or more and 75% by mol or less in a total amount of the alcohol component, the carboxylic acid component and the polyethylene terephthalate as one mole of a unit of terephthalic acid-ethylene glycol in the amorphous polyester resin A.

3. The toner for electrostatic image development according to claim 1, wherein the content of the polyethylene terephthalate is 15% by mol or more and 65% by mol or less in a total amount of the alcohol component, the carboxylic acid component and the polyethylene terephthalate as one mole of a unit of terephthalic acid-ethylene glycol in the amorphous polyester resin A.

4. The toner for electrostatic image development according to any one of claims 1 to 3, wherein an IV value of the polyethylene terephthalate is 0.40 or more and 0.80 or less.

5. The toner for electrostatic image development according to any one of claims 1 to 4, wherein the content of the crystalline polyester resin C is 3% by mass or more and 30% by mass or less in a total amount of the crystalline polyester resin C and the amorphous polyester resin A.

6. The toner for electrostatic image development according to any one of claims 1 to 5, wherein the monofunctional monomer comprises an aliphatic monocarboxylic acid compound having 9 or more carbon atoms and 24 or less carbon atoms and / or an aliphatic monoalcohol having 9 or more carbon atoms and 24 or less carbon atoms in the crystalline polyester resin C.

7. The toner for electrostatic image development according to any one of claims 1 to 6, wherein the content of the monofunctional monomer is 2% by mol or more and 30% by mol or less in a total amount of the alcohol component and the carboxylic acid component in the crystalline polyester resin C.

8. The toner for electrostatic image development according to any one of claims 1 to 7, wherein the alcohol component comprises an aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms in the amorphous polyester resin A.

9. The toner for electrostatic image development according to claim 8, wherein the content of the aliphatic diol having 3 or more carbon atoms and 6 or less carbon atoms is 30% by mol or more and 100% by mol or less in the alcohol component.

10. The toner for electrostatic image development according to any one of claims 1 to 9, wherein the number of carbon atoms of the aliphatic dicarboxylic acid compound is 10 or more and 16 or less in the crystalline polyester resin C.

11. The toner for electrostatic image development according to any one of claims 1 to 10, wherein the amorphous polyester resin A comprises amorphous resins having softening points different by 10°C or more.

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