Toner binder resin composition

Abstract

The present invention relates to a binder resin composition for toners that has excellent abrasion resistance and bending resistance, and toner for electrostatic image development containing the binder resin composition. [Solution] A binder resin composition for toner containing a polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the alcohol component contains a bisphenol A alkylene oxide adduct in which the average number of added alkylene oxide moles is 2.6 or more and 4.5 or less, and contains 40 mol% or more of a bisphenol A alkylene oxide adduct in which 3 moles or more of alkylene oxide are added, the content of the bisphenol A alkylene oxide adduct in which 3 moles or more of alkylene oxide are added in the total amount of ethylene glycol derived from the alcohol component and the polyethylene terephthalate is 3.0 mol% or more, and the content of the polyethylene terephthalate is 15% by mass or more and 80% by mass or less in the total amount of the alcohol component, carboxylic acid component, and polyethylene terephthalate, a binder resin composition for toner, and a toner for electrostatic image development containing the binder resin composition.

Description

[Technical Field]

[0001] The present invention relates to a binder resin composition for toner used for developing latent images formed in methods such as electrophotography, electrostatic recording, and electrostatic printing, and toner for developing electrostatic images containing the binder resin composition. [Background technology]

[0002] Patent Document 1 discloses a polyester resin that yields a toner with excellent storage properties, fixability, and fixability strength in high-temperature environments. This polyester resin is obtained using polyethylene terephthalate, a polyhydric carboxylic acid component, and a polyhydric alcohol component, and contains a total of 1 mole or more of at least one selected from the group consisting of trihydric or higher carboxylic acid-derived component and trihydric or higher alcohol-derived component, per 100 moles of component units derived from the acid component, and has an endothermic value of 0.1 to 10 J / g when heated at 150°C for 30 minutes.

[0003] On the other hand, Patent Document 2 discloses a toner binder resin that has good low-temperature fixing properties regardless of the pressure during fixing, comprising a polyester obtained by condensation polymerization of an alcohol component containing 30 mol% or more of a bisphenol A propylene oxide adduct and a carboxylic acid component, having a softening point of 70°C or more and less than 120°C, and a glass transition point of 45 to 70°C, wherein the content of the bisphenol A propylene oxide adduct, in which 3 moles or more of propylene oxide are added, is 40 mol% or more. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2022 / 009397 [Patent Document 2] Japanese Patent Publication No. 2006-301128 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, from an environmental protection standpoint, there has been an increase in printed materials that are not laminated, and abrasion resistance, which demonstrates robustness against external forces, is increasingly required. Furthermore, from a design perspective, there are occasions when printed materials are folded for use, and to prevent the printed area from peeling off and becoming damaged, printed materials also require excellent bending resistance.

[0006] The present invention relates to a binder resin composition for toner that has excellent abrasion resistance and bending resistance, and toner for electrostatic image development containing the binder resin composition. [Means for solving the problem]

[0007] The present invention [1] A binder resin composition for toner containing a polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the alcohol component contains a bisphenol A alkylene oxide adduct in which the average number of added alkylene oxide moles is 2.6 or more and 4.5 or less, and contains 40 mol% or more of a bisphenol A alkylene oxide adduct in which 3 moles or more of alkylene oxide are added, the content of the bisphenol A alkylene oxide adduct in which 3 moles or more of alkylene oxide are added in the total amount of ethylene glycol derived from the alcohol component and the polyethylene terephthalate is 3.0 mol% or more, and the content of the polyethylene terephthalate is 15% by mass or more and 80% by mass or less in the total amount of the alcohol component, carboxylic acid component, and polyethylene terephthalate, and [2] Toner for electrostatic image development containing the toner binder resin composition described in [1] above. Regarding. [Effects of the Invention]

[0008] The toner binder resin composition of the present invention exhibits excellent effects in terms of abrasion resistance and bending resistance. [Modes for carrying out the invention]

[0009] The toner binder resin composition of the present invention is a polycondensate of an alcohol component, a carboxylic acid component, and a predetermined amount of polyethylene terephthalate (PET), and is characterized in that the alcohol component contains a polyester resin (polyester resin A) which contains a predetermined amount of an alkylene oxide adduct of bisphenol A with 3 moles or more of alkylene oxide added. The reason why the toner binder resin composition of the present invention has excellent abrasion resistance and bending resistance is not clear, but it is presumed to be as follows.

[0010] To ensure abrasion resistance, the polyester resin used as a binder for toner needs to be sufficiently rigid. However, simply increasing the molecular weight or using rigid monomers reduces bending resistance. However, in this invention, by using a predetermined amount of PET, the PET-derived domains remaining in the resulting polyester resin provide hard areas with excellent abrasion resistance. On the other hand, by coexisting highly tough areas derived from alkylene oxide adducts of bisphenol A, which have alkylene oxide chains that contribute to flexibility, with the PET-derived domains, it is believed that both abrasion resistance and bending resistance can be achieved.

[0011] Polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component, and PET.

[0012] The alcohol component contains an alkylene oxide adduct of bisphenol A.

[0013] The alkylene oxide adduct of bisphenol A is given by formula (I):

[0014] [ka]

[0015] (In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y represent the average number of moles of alkylene oxide added, and are each a positive number) The compound represented by is preferred.

[0016] From the viewpoint of flexibility, the average number of moles of alkylene oxide added in the alkylene oxide adduct of bisphenol A (the value of the sum of x and y in formula (I)) is 2.6 or more, preferably 2.8 or more, more preferably 3.0 or more, and is 4.5 or less, preferably 4.0 or less, more preferably 3.5 or less.

[0017] From the viewpoint of flexibility, it contains an alkylene oxide adduct of bisphenol A to which 3 or more moles of alkylene oxide are added, and the content thereof is 40 mol% or more, preferably 45 mol% or more, more preferably 50 mol% or more, still more preferably 55 mol% or more in the alkylene oxide adduct of bisphenol A, and is 100 mol% or less, preferably 95 mol% or less, more preferably 90 mol% or less.

[0018] Also, the content of the alkylene oxide adduct of bisphenol A to which 3 or more moles of alkylene oxide are added in the total amount of the alcohol component and ethylene glycol derived from PET is 3.0 mol% or more, preferably 5.0 mol% or more, more preferably 10.0 mol% or more, and is preferably 55.0 mol% or less, more preferably 40.0 mol% or less, still more preferably 30.0 mol% or less.

[0019] Examples of the alkylene oxide adduct of bisphenol A include an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, etc. In the present invention, from the viewpoint of scratch resistance, a propylene oxide adduct of bisphenol A is preferred.

[0020] The alkylene oxide adduct of bisphenol A preferably contains two or more types selected from the group consisting of a 3-mol alkylene oxide adduct, a 4-mol alkylene oxide adduct, a 5-mol alkylene oxide adduct, and a 6-mol alkylene oxide adduct.

[0021] The content of the bisphenol A alkylene oxide adduct is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component.

[0022] Examples of alcohol components other than the alkylene oxide adduct of bisphenol A include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-butenediol, 1,3-butanediol, and neopentyl glycol, as well as trivalent or higher alcohols such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0023] Examples of carboxylic acid components include aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and trivalent or higher carboxylic acid compounds.

[0024] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0025] Examples of aliphatic dicarboxylic acid compounds include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0026] Examples of carboxylic acid compounds with a valency of 3 or higher include trimellitic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0027] The alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0028] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol and carboxylic acid components.

[0029] PET is an equimolar polycondensate of ethylene glycol and terephthalic acid. The ethylene glycol and terephthalic acid produced by the polycondensation reaction of an alcohol component and a carboxylic acid component, and / or by the depolymerization of a portion of PET, are used as raw material monomers in the polycondensation reaction and incorporated into the polyester resin.

[0030] The PET can be either new virgin PET or recycled PET. Recycled PET refers to material obtained by collecting used PET, washing it as needed, separating it from other materials, crushing it, depolymerizing the crushed material to monomer units, and then resynthesizing it using these monomers as raw materials.

[0031] In this invention, it is preferable that the PET has a relatively low IV value, i.e., a low molecular weight, compared to conventionally used PET. By introducing low IV value (low molecular weight) PET into the polyester resin, the depolymerization of PET proceeds more uniformly.

[0032] From the viewpoint of the above, the IV value of PET is preferably 0.40 or higher, more preferably 0.45 or higher, even more preferably 0.50 or higher, and still more preferably 0.55 or higher. From the viewpoint of low-temperature fixability and homogenization of depolymerization, it is preferably 0.85 or lower, more preferably 0.80 or lower, even more preferably 0.75 or lower, even more preferably 0.70 or lower, and still more preferably 0.65 or lower. The IV value is the intrinsic viscosity and serves as an indicator of molecular weight. The IV value of PET can be adjusted by the polycondensation time, etc.

[0033] Commercially available PET products with an IV value between 0.40 and 0.85 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), RAMAPET R1 / Reheat Grade (manufactured by Indorama Ventures, IV value: 0.84), and UK-31 (manufactured by Utsumi Recycle Systems Co., Ltd., IV value: 0.67).

[0034] The content of low-IV PET is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and 100% by mass or less, of the total amount of PET subjected to polycondensation.

[0035] The PET content is 15% by mass or more, preferably 25% by mass or more, more preferably 35% by mass or more, and 80% by mass or less, preferably 70% by mass or less, and more preferably 60% by mass or less, based on the total amount of alcohol component, carboxylic acid component, and PET.

[0036] The equivalent ratio (COOH group / OH group) of the carboxylic acid component (including terephthalic acid derived from PET) to the alcohol component (including ethylene glycol derived from PET) is preferably 0.6 or higher, more preferably 0.7 or higher, even more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0037] Polyester resins can be produced, for example, by polycondensing an alcohol component, a carboxylic acid component, and PET in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and optionally in the presence of a co-catalyst, polymerization inhibitor, etc., at a temperature preferably 130°C or higher, more preferably 170°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0038] Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolamine) and titanium dihydroxybis(triethanolamine). The amount of esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, and more preferably 1 part by mass or less, per 100 parts by mass of the total amount of alcohol component, carboxylic acid component, and PET. Examples of co-catalysts for the esterification catalyst include gallic acid. The amount of co-catalyst used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the total amount of alcohol component, carboxylic acid component, and PET. Examples of polymerization inhibitors include tert-butylcatechol. The amount of polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and 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 the total amount of alcohol component, carboxylic acid component, and PET.

[0039] In this invention, the polyester resin may be a polyester resin that has been modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins that have been grafted or blocked with phenol, urethane, epoxy, etc., by methods described in Japanese Patent Publication No. 11-133668, Japanese Patent Publication No. 10-239903, Japanese Patent Publication No. 8-20636, etc. Among modified polyester resins, urethane-modified polyester resins obtained by urethane elongation of polyester resin with a polyisocyanate compound are preferred.

[0040] The softening point of polyester resin A is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, from the viewpoint of static stability, and preferably 170°C or lower, more preferably 160°C or lower, even more preferably 155°C or lower, even more preferably 130°C or lower, even more preferably 120°C or lower, and even more preferably 110°C or lower.

[0041] The glass transition temperature of polyester resin A is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of toner storage properties, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of electrostatic stability.

[0042] The acid value of polyester resin A is preferably 3 mg KOH / g or more, more preferably 5 mg KOH / g or more, from the viewpoint of electrostatic stability, and preferably 60 mg KOH / g or less, more preferably 45 mg KOH / g or less, from the viewpoint of hygroscopic resistance.

[0043] The content of polyester resin A in the toner binder resin composition is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and 100% by mass or less, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less.

[0044] The toner binder resin composition of the present invention is preferably composed of two resins with different softening points, from the viewpoint of low-temperature fixability and fixation width. The difference in softening points of the two resins is preferably 10°C or more, more preferably 20°C or more, and preferably 60°C or less, more preferably 50°C or less.

[0045] The softening point of the resin with the higher softening point (resin AH) is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher, from the viewpoint of fixing width, and preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 155°C or lower, from the viewpoint of low-temperature fixing properties.

[0046] Furthermore, the softening point of the resin with the lower softening point (resin AL) is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, from the viewpoint of electrostatic stability, and preferably 130°C or lower, more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixation.

[0047] The mass ratio of resin AL to resin AH (resin AL / resin AH) is preferably 20 / 80 or more, more preferably 30 / 70 or more, even more preferably 40 / 60 or more, and preferably 90 / 10 or less, more preferably 85 / 15 or less, and even more preferably 80 / 20 or less.

[0048] In the toner binder resin composition of the present invention, either resin AH or resin AL may be polyester resin A, or both may be polyester resin A. However, from the viewpoint of abrasion resistance, it is preferable that resin AL is polyester resin A.

[0049] Therefore, if the toner binder resin composition of the present invention contains a polyester resin other than polyester resin A (hereinafter referred to as polyester resin B), it is preferable that polyester resin B is resin AH.

[0050] The polyester resin B is preferably a polycondensate of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component.

[0051] Examples of alkylene oxide adducts of bisphenol A include ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A.

[0052] The average number of moles of alkylene oxide added is preferably 1.9 or more, more preferably 2.0 or more, even more preferably 2.1 or more, and preferably 3.0 or less, more preferably 2.9 or less, and even more preferably 2.8 or less.

[0053] The content of the bisphenol A alkylene oxide adduct is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component.

[0054] From the viewpoint of electrostatic stability, the carboxylic acid component preferably includes an aromatic dicarboxylic acid compound.

[0055] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0056] The content of aromatic dicarboxylic acid compounds is preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 50 mol% or more, and 100 mol% or less, preferably 95 mol% or less, and more preferably 90 mol% or less, in the carboxylic acid component.

[0057] Examples of carboxylic acid components other than aromatic dicarboxylic acid compounds include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups, aliphatic dicarboxylic acids such as glutaric acid, adipic acid, and sebacic acid, trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0058] The alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0059] Polyester resin B can be manufactured in the same manner as polyester resin A, except that PET is not used.

[0060] The softening point of polyester resin B is preferably 80°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, even more preferably 110°C or higher, and even more preferably 120°C or higher. Furthermore, from the viewpoint of low-temperature fixation, it is preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 155°C or lower.

[0061] The glass transition temperature of polyester resin B is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of toner storage properties, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of electrostatic stability.

[0062] The acid value of polyester resin B is preferably 1 mg KOH / g or more, more preferably 3 mg KOH / g or more, from the viewpoint of electrostatic stability, and preferably 20 mg KOH / g or less, more preferably 18 mg KOH / g or less, from the viewpoint of hygroscopic resistance.

[0063] The content of polyester resin B in the toner binder resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

[0064] The mass ratio of polyester resin A to polyester resin B (polyester resin A / polyester resin B) is preferably 20 / 80 or more, more preferably 30 / 70 or more, even more preferably 40 / 60 or more, and preferably 90 / 10 or less, more preferably 85 / 15 or less, and even more preferably 80 / 20 or less.

[0065] The total content of polyester resin A and polyester resin B in the toner binder resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, and 100% by mass or less.

[0066] Other resins include vinyl resins such as styrene-acrylic resin, polyamide resin, epoxy resin, polycarbonate resin, polyurethane resin, and composite resins containing two or more of these resins.

[0067] Furthermore, the present invention provides a toner for electrostatic image development that contains the toner binder resin composition of the present invention as the binder resin.

[0068] The content of the toner binder resin composition is preferably 60% by mass or more, more preferably 70% by mass or more, and preferably less than 100% by mass, more preferably 95% by mass or less, and even more preferably 93% by mass or less, in the toner.

[0069] The toner of the present invention may contain additives other than the binder resin (binder resin composition), such as colorants, release agents, charge control agents, magnetic powders, flowability improvers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, and cleaning properties improvers.

[0070] As colorants, dyes, pigments, magnetic materials, etc., used as colorants for toners can be used. Examples include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, etc. In this invention, the toner may be either black toner or color toner.

[0071] From the viewpoint of improving the toner's image density and low-temperature fixability, the colorant content is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and 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, per 100 parts by mass of the binder resin composition.

[0072] Examples of mold release agents include hydrocarbon waxes and their oxides, such as polypropylene wax, polyethylene wax, ethylene propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; ester waxes such as carnauba wax, montane wax and their deoxidizing waxes, and fatty acid ester waxes; and fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., which can be used individually or in combination of two or more.

[0073] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of toner transferability, and preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixation.

[0074] The release agent content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.5 parts by mass or more, and 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 viewpoint of low-temperature fixation and offset resistance of the toner and dispersibility in the binder resin composition, per 100 parts by mass of the binder resin composition.

[0075] The charge control agent is not particularly limited and may contain either a positively charged charge control agent or a negatively charged charge control agent.

[0076] Positively charged charge control agents include nigrosine dyes, such as "Nigrosine Base EX," "Oil Black BS," "Oil Black SO," "Bontron N-01," "Bontron N-04," "Bontron N-07," "Bontron N-09," "Bontron N-11," and "Bontron N-79" (all manufactured by Orient Chemical Industries, Ltd.); triphenylmethane-based dyes containing tertiary amines as side chains; quaternary ammonium salt compounds, such as "Bontron P-51" (manufactured by Orient Chemical Industries, Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX." Examples include VP435 (manufactured by Clariant), polyamine resins such as AFP-B (manufactured by Orient Chemical Industries, Ltd.), imidazole derivatives such as PLZ-2001 and PLZ-8001 (both manufactured by Shikoku Chemicals, Ltd.), and styrene-acrylic resins such as FCA-701PT and FCA-201-PS (manufactured by Fujikura Chemicals, Ltd.).

[0077] Furthermore, as negative charge control agents, metal-containing azo dyes, such as "Barifast Black 3804," "Bontron S-31," "Bontron S-32," "Bontron S-34," and "Bontron S-36" (all manufactured by Orient Chemical Industries, Ltd.), "Eisenspiron Black TRH," and "T-77" (manufactured by Hodogaya Chemical Co., Ltd.); metal compounds of benzyl acid compounds, such as "LR-147" and "LR-297" (both manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds, such as "Bontron E-81," "Bontron E-84," "Bontron E-88," and "Bontron E-304" (all manufactured by Orient Chemical Industries, Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dyes; and quaternary ammonium salts, such as "COPY CHARGE NX" Examples include VP434 (manufactured by Clariant), nitroimidazole derivatives, organometallic compounds, etc.

[0078] From the viewpoint of the charge control stability of the toner, the content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and 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, per 100 parts by mass of the binder resin composition.

[0079] The toner of the present invention may be obtained by any of the conventionally known methods, such as the melt-kneading method, the emulsification-coagulation method, or the suspension polymerization method, and may also be a toner having a core-shell structure. However, from the viewpoint of the miscibility of the toner components, a pulverized toner obtained by the melt-kneading method, that is, a pulverized toner obtained by a method including the steps of melt-kneading raw materials and pulverizing the resulting mixture, is preferred. Specifically, for example, polyester resin A and, if necessary, polyester resin B, colorants, release agents, charge control agents, and other raw materials can be uniformly mixed in a mixer such as a Henschel mixer, then melt-kneaded in a closed-type kneader, a single-screw or twin-screw extruder, an open-roll type kneader, etc., and then cooled, pulverized, and classified to produce the toner. The polyester resin A and polyester resin B constituting the binder resin composition for toner of the present invention may be used pre-mixed, or they may be used directly or mixed with other raw materials.

[0080] In the toner of the present invention, it is preferable to use an external additive to improve fluidity. Examples of external additives include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more may be used in combination. Among these, silica is preferred, and from the viewpoint of toner fluidity, hydrophobic silica that has been hydrophobicized is more preferred.

[0081] Examples of hydrophobic agents used to hydrophobize the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0082] The average particle size of the external additive is preferably 10 nm or larger, more preferably 250 nm or smaller, more preferably 200 nm or smaller, and even more preferably 90 nm or smaller, from the viewpoint of the toner's chargeability, fluidity, and transferability.

[0083] External additive treatment, which involves mixing toner particles with external additives, can be carried out according to conventional methods, and a mixer such as a Henschel mixer can be used.

[0084] From the viewpoint of the toner's electrostatic properties, fluidity, and transferability, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, and more preferably 4 parts by mass or less, per 100 parts by mass of toner particles before treatment with the external additive.

[0085] The volume-intermediate particle size (D) of the toner of the present invention 50 The volume median particle size (D) is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. 50 ) refers to the particle size at which the cumulative volume frequency calculated using volume fractions accounts for 50% when calculated from the smallest particle size. Furthermore, if the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is taken as the volume median particle size of the toner.

[0086] The toner of the present invention can be used as is as a one-component developing toner, or as a two-component developing toner used in combination with a carrier, in image forming apparatuses using either a one-component developing method or a two-component developing method, respectively. [Examples]

[0087] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The physical properties of resins, etc., can be measured by the following methods.

[0088] [PET IV value] The phenol / tetrachloroethane is dissolved at a concentration of 4 g / L in a 60 / 40 (mass ratio) mixed solvent, and the concentration is measured using an Ubbelohde viscometer and calculated using the following formula. IV = (-1 + √(1 + 4kη)) / (2kC) [In the formula, k = 0.33, C = 0.004 g / mL, and η = (t1 / t0) - 1 (t0: number of seconds for the solvent to fall, t1: number of seconds for the sample solution to fall).]

[0089] [Softening point of resin] Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample is heated at a heating rate of 6°C / min while a load of 1.96 MPa is applied by a plunger, and the sample is extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The amount of plunger descent of the flow tester is plotted against temperature, and the temperature at which half of the sample has flowed out is defined as the softening point.

[0090] [Glass transition temperature of resins] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan, heated to 200°C, and then cooled to 0°C at a rate of 10°C / min. Next, the sample is heated again at a rate of 10°C / min, and the endothermic peak is measured. The temperature at the intersection of the baseline extension below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rise of the peak to the peak apex is defined as the glass transition temperature.

[0091] [Acid value of resins] The measurement will be performed according to the method of JIS K 0070:1992. However, the measurement solvent will be changed from the ethanol and ether mixture specified in JIS K 0070 to an acetone and toluene mixture (acetone:toluene = 1:1 (volume ratio)).

[0092] [Melting point of release agent] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample is weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. Next, the sample is heated again at a rate of 10°C / min, the amount of heat is measured, and the maximum peak temperature of endothermic heating is defined as the melting point.

[0093] [Average particle size of external additives] The average particle diameter refers to the number-average particle diameter, which is calculated by measuring the particle size (average of the major and minor axes) of 500 particles from scanning electron microscope (SEM) images and using the number-average value of these measurements.

[0094] [Toner volume medium particle size (D 50 )〕 • Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 50 μm • Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Dispersion: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] in the electrolyte to adjust the concentration to 5% by mass. • Dispersion conditions: Add 10 mg of the sample to 5 mL of the dispersion and disperse for 1 minute using an ultrasonic disperser (machine name: US-1 manufactured by SND Corporation, output: 80W). Then, add 25 mL of electrolyte and disperse for another minute using the ultrasonic disperser to prepare the sample dispersion. • Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, the 30,000 particles are measured, and the volume median particle size (D) is determined from the particle size distribution. 50 )

[0095] Production Example 1 of an alkylene oxide adduct of bisphenol A In an autoclave equipped with stirring and temperature control functions, 228 g (1 mole) of bisphenol A and 2 g of potassium hydroxide were placed, and 174 g (3.0 mole) of propylene oxide was introduced at 135°C under a pressure in the range of 0.1 to 0.4 MPa, followed by an addition reaction for 3 hours. 16 g of the adsorbent "Kyoward 600" (manufactured by Kyowa Chemical Industry Co., Ltd., 2MgO·6SiO2·XH2O) was added to the reaction product, and the mixture was stirred and aged at 90°C for 30 minutes. The mixture was then filtered to obtain the bisphenol A propylene oxide adduct (BPA-PO1).

[0096] Production Example 2 of an Alkylene Oxide Adduct of Bisphenol A Except for changing the amount of propylene oxide used as shown below, bisphenol A propylene oxide adducts (BPA-PO2, BPA-PO3, BPA-PO5~BPA-PO7) were obtained in the same manner as in Production Example 1.

[0097] BPA-PO2: Propylene oxide 168g (2.9 mol) BPA-PO3: Propylene oxide 226g (3.9 mol) BPA-PO5: Propylene oxide 128g (2.2 moles) BPA-PO6: Propylene oxide 916g (15.8 mol) BPA-PO7: Propylene oxide 307g (5.3 mol)

[0098] Production Example 3 of an alkylene oxide adduct of bisphenol A In an autoclave equipped with stirring and temperature control functions, 228 g (1 mol) of bisphenol A and 1.5 g of potassium hydroxide were placed, and 168 g (2.9 mol) of propylene oxide was introduced at 135°C under a pressure in the range of 0.1 to 0.4 MPa, followed by an addition reaction for 5 hours. 16 g of the adsorbent "Kyoward 600" (manufactured by Kyowa Chemical Industry Co., Ltd., 2MgO·6SiO2·XH2O) was added to the reaction product, and the mixture was stirred and aged at 90°C for 30 minutes. The mixture was then filtered to obtain the bisphenol A propylene oxide adduct (BPA-PO4).

[0099] Production Example 4 of an alkylene oxide adduct of bisphenol A In an autoclave equipped with stirring and temperature control functions, 228 g (1 mole) of bisphenol A and 2 g of potassium hydroxide were placed, and 132 g (3.0 mole) of ethylene oxide was introduced at 135°C under a pressure in the range of 0.1 to 0.4 MPa, followed by an addition reaction for 3 hours. 16 g of the adsorbent "Kyoward 600" (manufactured by Kyowa Chemical Industry Co., Ltd., 2MgO·6SiO2·XH2O) was added to the reaction product, and the mixture was stirred and aged at 90°C for 30 minutes. The mixture was then filtered to obtain the ethylene oxide adduct of bisphenol A (BPA-EO1).

[0100] Production Example 5 of an alkylene oxide adduct of bisphenol A Except for changing the amount of ethylene oxide used to 97 g (2.2 moles), the ethylene oxide adduct of bisphenol A (BPA-EO2) was obtained in the same manner as in Production Example 4.

[0101] Table 1 shows the breakdown of the number of moles of alkylene oxide added to the obtained bisphenol A alkylene oxide adduct. The breakdown of the number of moles of alkylene oxide added was determined by calculating the mass ratio from the peak area ratio of gas chromatography, and then converting the mass ratio to molecular weight to determine the molar ratio.

[0102] [Table 1]

[0103] Resin manufacturing example 1 In a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube, the alcohol components shown in Tables 2 and 3, terephthalic acid, PET, esterification catalyst, and co-catalyst were added. The mixture was reacted at 235°C for 6 hours under a nitrogen atmosphere using a mantle heater, and then cooled to 200°C. After that, adipic acid shown in Tables 2 and 3 was added, and the temperature was raised to 210°C to continue the reaction until the softening point shown in Tables 2 and 3 was reached, yielding polyester resins (resins AL1-AL13, AL16, AL17). The physical properties of the obtained resins are shown in Tables 2 and 3.

[0104] Resin manufacturing example 2 In a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, fractionation column, dehydration tube, condenser, and nitrogen inlet tube, the alcohol components, terephthalic acid, PET, esterification catalyst, and co-catalyst shown in Table 3 were added. The mixture was heated to 185°C in a mantle heater under a nitrogen atmosphere and reacted for 5 hours. After that, the temperature was gradually increased to 235°C at a rate of 5°C / h. Polycondensation was carried out at 235°C for 4 hours, and then the mixture was cooled to 200°C. Subsequently, adipic acid shown in Table 3 was added, and the temperature was raised to 210°C to continue the reaction until the softening point shown in Table 3 was reached, yielding polyester resins (resins AL14, AL15). The physical properties of the obtained resins are shown in Table 3.

[0105] Resin manufacturing example 3 In a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube, the alcohol components, terephthalic acid, esterification catalyst, and co-catalyst shown in Table 3 were added. The mixture was reacted at 235°C for 6 hours under a nitrogen atmosphere using a mantle heater, and then cooled to 200°C. After that, adipic acid shown in Table 3 was added, and the temperature was raised to 210°C to continue the reaction until the softening point shown in Table 3 was reached, yielding a polyester resin (resin BL1). The physical properties of the obtained resin are shown in Table 3.

[0106] [Table 2]

[0107] [Table 3]

[0108] Resin manufacturing example 4 In a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube, the alcohol components, terephthalic acid, esterification catalyst, and co-catalyst shown in Table 4 were added. The mixture was reacted at 235°C for 6 hours under a nitrogen atmosphere using a mantle heater, and then cooled to 200°C. Subsequently, adipic acid and trimellitic anhydride shown in Table 4 were added, and the temperature was raised to 210°C to continue the reaction until the softening point shown in Table 4 was reached, yielding a polyester resin (resin BH1). The physical properties of the obtained resin are shown in Table 4.

[0109] Resin manufacturing example 5 A 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube contained the alcohol components, PET, adipic acid, esterification catalyst, and co-catalyst shown in Table 4. The mixture was reacted at 235°C for 5 hours under a nitrogen atmosphere using a mantle heater, and then cooled to 200°C. Subsequently, trimellitic anhydride shown in Table 4 was added, and the temperature was raised to 210°C to continue the reaction until the softening point shown in Table 4 was reached, yielding a polyester resin (resin AH1). The physical properties of the obtained resin are shown in Table 4.

[0110] [Table 4]

[0111] Examples 1-13, Comparative Examples 1-6 A total of 100 parts by mass of the binder resin composition shown in Table 5, 1 part by mass of the negative charge control agent "Bontron E-81" (manufactured by Orient Chemical Industry Co., Ltd.), 5 parts by mass of the coloring agent "Pigment blue 15:3" (manufactured by Dainichi Seika Kogyo Co., Ltd., phthalocyanine blue), and 2 parts by mass of the release agent "HNP-9" (manufactured by Nippon Seiro Co., Ltd., paraffin wax, melting point: 80°C) were thoroughly mixed in a Henschel mixer. Then, using a twin-screw extruder with a total length of 1560 mm in the mixing section, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm, the mixture was melt-kneaded at a roll rotation speed of 200 r / min and a heating temperature in the rolls of 100°C. The feed rate of the mixture was 20 kg / h, and the average residence time was approximately 18 seconds. The obtained molten mixture was cooled and coarsely ground, then ground in a jet mill and classified to obtain the medium volume particle size (D 50 ) yielded toner particles with a diameter of 8 μm.

[0112] Toner was obtained by adding 1.0 part by mass of hydrophobic silica "AEROSIL NAX 50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: HMDS, average particle size: approximately 30 nm) as an external additive to 100 parts by mass of the obtained toner particles and mixing them in a Henschel mixer.

[0113] Test Example 1 [Abrasion Resistance] Each toner was installed in a Sharp AR-505 copier, and Business4200 paper (weighing 105g / m²) was used as the evaluation paper. 2 Using a Xerox printer, the toner application rate was 0.50 mg / cm². 2 The solid image was fixed by passing it through a fuser machine heated to 180°C. The resulting fixed image was left for one month in an environment of 40°C and 80% relative humidity. The fixed image after the period of time was rubbed five times back and forth with a 15mm x 7.5mm sand eraser with a 500g load applied. The optical reflectance density before and after rubbing was measured using a reflectance densitometer "RD-915" (Macbeth Corporation), and the percentage decrease in optical reflectance density was calculated using the following formula to evaluate the abrasion resistance of the fixed image. The results are shown in Table 5. Percentage decrease in optical reflectance = [1 - (Optical reflectance after rubbing / Optical reflectance before rubbing)] × 100

[0114] Test Example 2 [Flexural Fatigue Resistance] Toner was installed in a color printer "C612dnw" (manufactured by Oki Electric Industry Co., Ltd.), and two types of images were printed without fixing (printing area: 4 cm in length × 12 cm in width (common), adhesion amount: 1.5 mg / cm 2 and 0.7 mg / cm 2 ). The unfixed image was fixed at 150 °C and 200 mm / sec by using the fixing unit of the printer offline. J paper (manufactured by Fujifilm Business Innovation Co., Ltd., basis weight: 82 g / m 2 , paper thickness: 97 μm) was used as the fixing paper. With a 2-cm vertical line of the fixed image as the fold line, the fixed image was folded in half with the image inside, and after a cylindrical weight "M1CSB-1KA" of 1 kg (manufactured by Ikeda Rika Co., Ltd., bottom diameter: 5 cm) was reciprocated twice on the fold line, it was opened and the fold line was observed. The flexural fatigue resistance was evaluated according to the following evaluation criteria. The results are shown in Table 5.

[0115] <Evaluation Criteria> A: No white spots are observed in either the 1.5 mg / cm 2 or 0.7 mg / cm 2 image. B: White spot dropout is observed in one or more places in the 1.5 mg / cm 2 image, but not in the 0.7 mg / cm 2 image. C: White spot dropout is observed in one or more places in the 0.7 mg / cm 2 image. D: A white line of more than 5 mm and less than 1 cm is observed in the 0.7 mg / cm 2 image. E: A white line of more than 1 cm and less than 5 cm is observed in the 0.7 mg / cm 2 image.

[0116]

Table 5

[0117] From the results above, it can be seen that Examples 1 to 13 exhibit good resistance to both abrasion and bending. In contrast, Comparative Examples 1-3 and 6, in which the average number of added moles of alkylene oxide used in the polyester resin was small, or in which the amount of bisphenol A alkylene oxide adduct, in which 3 moles or more of alkylene oxide were added to the alcohol component and PET-derived ethylene glycol, was small, lacked bending resistance. Comparative Example 4, in which the average number of added moles of alkylene oxide used in the polyester resin was large, and Comparative Example 5, in which the amount of PET was small, lacked abrasion resistance. [Industrial applicability]

[0118] The toner for electrostatic image development containing the toner binder resin composition of the present invention is suitably used for developing latent images formed in electrostatic image development methods, electrostatic recording methods, electrostatic printing methods, and the like.

Claims

1. A binder resin composition for toner containing a polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the alcohol component contains a bisphenol A alkylene oxide adduct in which the average number of added alkylene oxide moles is 2.6 or more and 4.5 or less, and contains 40 mol% or more of a bisphenol A alkylene oxide adduct in which 3 moles or more of alkylene oxide are added, the content of the bisphenol A alkylene oxide adduct in which 3 moles or more of alkylene oxide are added in the total amount of ethylene glycol derived from the alcohol component and the polyethylene terephthalate is 3.0 mol% or more, and the content of the polyethylene terephthalate is 15% by mass or more and 80% by mass or less in the total amount of the alcohol component, carboxylic acid component, and polyethylene terephthalate.

2. The toner binder resin composition according to claim 1, wherein the alkylene oxide adduct of bisphenol A contains two or more selected from the group consisting of a 3-mol alkylene oxide adduct, a 4-mol alkylene oxide adduct, a 5-mol alkylene oxide adduct, and a 6-mol alkylene oxide adduct.

3. The toner binder resin composition according to claim 1 or 2, wherein the softening point of polyester resin A is 80°C or higher and 120°C or lower.

4. The toner binder resin composition according to claim 1 or 2, wherein the IV value of polyethylene terephthalate is 0.50 or more and 0.80 or less.

5. A toner for developing electrostatic images containing the toner binder resin composition according to claim 1 or 2.

Images