Toner binder

Abstract

To provide a toner binder that is excellent in low-temperature fixability, hot offset resistance, pulverizability, and chargeability. [Solution] A toner binder comprising a polyester resin (A) obtained by polycondensation of an alcohol component (x) and a carboxylic acid component (y), and a terpene phenol resin (B), wherein the alcohol component (x) contains ethylene glycol and propylene glycol, the carboxylic acid component (y) contains terephthalic acid, the molar ratio of ethylene glycol to propylene glycol (EG / PG) is 0.4 to 1.0, the total number of moles of ethylene glycol and propylene glycol is 75 mol% or more based on the total number of moles of (x), the glass transition temperature of the terpene phenol resin (B) is 75 to 100°C, and the weight ratio of the polyester resin (A) to the terpene phenol resin (B) [(A) / (B)]] is 90 / 10 to 70 / 30.

Description

[Technical Field]

[0001] The present invention relates to toner binders. [Background technology]

[0002] In recent years, along with the promotion of miniaturization, speedup and high image quality of electrophotographic apparatuses, there has been a strong demand for improved low-temperature fixability of toners from the viewpoint of energy conservation, namely, reducing energy consumption in the fixing process. The toner binder has a significant effect on the above-mentioned toner characteristics, and known examples include polystyrene resin, styrene-acrylic resin, polyester resin, epoxy resin, polyurethane resin, and polyamide resin. Recently, polyester resin has been attracting particular attention because it is easy to achieve a balance between storage stability and fixability. For example, a toner using a crystalline polyester resin with excellent melting properties and an amorphous resin has been proposed for the purpose of achieving low-temperature fixability (see Patent Document 1). Furthermore, toners containing amorphous bioplastics such as amorphous polylactic acid, terpene phenol resins, and styrene acrylic resins have been proposed as toners with excellent grindability, fixability, and durability (see Patent Document 2). However, when the particle size of the toner is reduced to meet the demand for even higher image quality, the dispersibility of the crystalline polyester resin in the toner using the above-mentioned crystalline polyester resin is not sufficient, and improvements in this respect are desired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-287426 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-1216 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a toner binder that is excellent in low-temperature fixability, hot offset resistance, pulverizability, and chargeability. [Means for solving the problem]

[0005] The present inventors have conducted extensive research and have arrived at the present invention. That is, the present invention provides a toner binder comprising a polyester resin (A) obtained by polycondensing an alcohol component (x) and a carboxylic acid component (y), and a terpene phenol resin (B), wherein the alcohol component (x) contains ethylene glycol and propylene glycol, the carboxylic acid component (y) contains terephthalic acid, the molar ratio of the ethylene glycol to the propylene glycol (EG / PG) is 0.4 to 1.0, the total number of moles of ethylene glycol and propylene glycol is 75 mol % or more based on the total number of moles of the alcohol component (x), the glass transition temperature of the terpene phenol resin (B) is 75 to 100°C, and the weight ratio of the polyester resin (A) to the terpene phenol resin (B) [(A) / (B)]] is 90 / 10 to 70 / 30. [Effects of the Invention]

[0006] The toner binder of the present invention is excellent in low-temperature fixability, hot offset resistance, pulverizability and chargeability. DETAILED DESCRIPTION OF THE INVENTION

[0007] The toner binder of the present invention is A toner binder comprising a polyester resin (A) obtained by polycondensing an alcohol component (x) and a carboxylic acid component (y) and a terpene phenol resin (B), the alcohol component (x) comprises ethylene glycol and propylene glycol; the carboxylic acid component (y) comprises terephthalic acid, the molar ratio of the ethylene glycol to the propylene glycol (EG / PG) is 0.4 to 1.0; the total number of moles of ethylene glycol and propylene glycol is 75 mol% or more based on the total number of moles of the alcohol component (x); The terpene phenol resin (B) has a glass transition temperature of 75 to 100°C, The weight ratio of the polyester resin (A) to the terpene phenol resin (B) [(A) / (B)] is 90 / 10 to 70 / 30 in the toner binder.

[0008] <Polyester resin (A)> The toner binder of the present invention contains a polyester resin (A) obtained by polycondensing an alcohol component (x) and a carboxylic acid component (y).

[0009] The polyester resin (A) in the present invention is a polyester resin obtained by polycondensation of an alcohol component (x) and a carboxylic acid component (y). The alcohol component (x) contains ethylene glycol and propylene glycol as essential components, and the carboxylic acid component (y) contains terephthalic acid as an essential component. Furthermore, the ethylene glycol as the alcohol component (x) and the terephthalic acid as the carboxylic acid component (y) may be ethylene glycol and terephthalic acid derived from PET (polyethylene terephthalate). Using PET as the raw material is preferred because the metal (catalyst residue) contained in the PET causes salt crosslinking with the carboxylic acid groups of the polyester, further improving hot offset resistance.

[0010] The alcohol component (x) may contain, in addition to the essential components ethylene glycol and propylene glycol, a diol other than ethylene glycol and propylene glycol, and a trihydric or higher polyol.

[0011] Diols other than ethylene glycol and propylene glycol include aliphatic diols, alicyclic diols and aromatic diols.

[0012] Examples of aliphatic diols include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,18-octadecanediol, 1,19-nonadecanediol, and 1,20-eicosanediol. From the viewpoint of low-temperature fixability, aliphatic diols having 6 to 12 carbon atoms are preferred.

[0013] Examples of the alicyclic diol include 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 5-norbornene-2,3-dimethanol, hydrogenated bisphenol A, spiroglycol, isosorbide, and alkylene oxide (hereinafter, "alkylene oxide" may be abbreviated as AO) adducts of the above alicyclic diols.

[0014] Examples of the alkylene oxide adduct of the alicyclic diol include an ethylene oxide (hereinafter, "ethylene oxide" may be abbreviated as EO) adduct, a propylene oxide (hereinafter, "propylene oxide" may be abbreviated as PO) adduct, and a butylene oxide (hereinafter, "butylene oxide" may be abbreviated as BO) adduct of the alicyclic diol. The average number of moles of the alkylene oxide added is preferably 1 to 30, and more preferably 2 to 5.

[0015] Examples of aromatic diols include 1,3-benzenedimethanol, 1,4-benzenedimethanol, bisphenol A, bisphenol F, bisphenol B, bisphenol AD, bisphenol S, trichlorobisphenol A, tetrachlorobisphenol A, dibromobisphenol F, 2-methylbisphenol A, 2,6-dimethylbisphenol A, and 2,2'-diethylbisphenol F, as well as alkylene oxide adducts of the above aromatic diols.

[0016] Examples of the alkylene oxide adducts of the aromatic diols include EO adducts, PO adducts, and BO adducts of the aromatic diols. The average number of moles of the alkylene oxide added is preferably 1 to 15, and more preferably 2 to 5. Among these aromatic diols, from the viewpoint of low-temperature fixability, alkylene oxide adducts of bisphenol A are preferred, and alkylene oxide adducts of bisphenol A with 2 to 5 moles are more preferred.

[0017] Examples of trihydric or higher polyols include polyhydric aliphatic alcohols (alkane polyols and their intramolecular or intermolecular dehydration products, such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, and polyglycerin; sugars and their partial esters, such as sucrose and methyl glucoside); alkylene oxide adducts of trisphenols (trisphenol PA, etc.) (the number of moles added is preferably 2 to 30); alkylene oxide adducts of novolak resins (including phenol novolak and cresol novolak, the average degree of polymerization of which is preferably 3 to 60) (the number of moles added is preferably 2 to 30); and acrylic polyols [copolymers of hydroxyethyl (meth)acrylate and other vinyl monomers, etc.]. Of these trivalent or higher polyols, trivalent polyols are preferred from the viewpoint of low-temperature fixability, and glycerin and trimethylolpropane are more preferred, with glycerin being particularly preferred.

[0018] The molar ratio (EG / PG) of ethylene glycol to propylene glycol in the alcohol component (x) is 0.4 to 1.0, preferably 0.45 to 1.0, and more preferably 0.5 to 1.0. If it is less than 0.4, hot offset resistance deteriorates, and if it exceeds 1.0, charging properties deteriorate.

[0019] The total number of moles of ethylene glycol and propylene glycol in the alcohol component (x) is 75 mol % or more, preferably 75 to 100 mol %, and more preferably 75 to 98 mol %, based on the number of moles of the alcohol component (x). If it is less than 75 mol %, the chargeability or heat-resistant storage stability may be poor.

[0020] Examples of the carboxylic acid component (y) include terephthalic acid, which is an essential component, as well as aliphatic dicarboxylic acids, aromatic dicarboxylic acids having 8 to 20 carbon atoms other than terephthalic acid, trivalent or higher polycarboxylic acids, and anhydrides and lower alkyl (having 1 to 4 carbon atoms) esters (methyl ester, ethyl ester, isopropyl ester, etc.) of these acids.

[0021] Examples of the aliphatic dicarboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, and 1,18-octadecanedicarboxylic acid.

[0022] Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sulfoisophthalate (sodium and potassium salts), and 4,4'-biphenyldicarboxylic acid. These acids may also be used as anhydrides or lower alkyl esters. The lower alkyl esters may be either monoesters or diesters. The lower alkyl is preferably an alkyl having 1 to 4 carbon atoms, more preferably methyl or ethyl, and particularly preferably ethyl.

[0023] Examples of trivalent or higher polycarboxylic acids include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), aliphatic tricarboxylic acids having 6 to 36 carbon atoms (such as hexanetricarboxylic acid), and vinyl polymers of unsaturated carboxylic acids [number average molecular weight (Mn): 450 to 10,000] (such as styrene / maleic acid copolymer, styrene / acrylic acid copolymer, and styrene / fumaric acid copolymer). Anhydrides or lower alkyl esters of these acids may also be used. The lower alkyl esters may be monoesters, diesters, or triesters. The lower alkyl is preferably an alkyl having 1 to 4 carbon atoms, more preferably methyl or ethyl, and particularly preferably ethyl.

[0024] Of the carboxylic acid components (y) other than terephthalic acid, from the viewpoint of low-temperature fixability, aliphatic dicarboxylic acids, 5-dimethyl sulfoisophthalate, and trimellitic acid are preferred, and aliphatic dicarboxylic acids having 4 to 10 carbon atoms, 5-dimethyl sulfoisophthalate, and trimellitic acid are more preferred.

[0025] The content of 5-sulfoisophthalic acid salt and / or its lower alkyl ester in the carboxylic acid component (y) is preferably 1 to 5 mol %, more preferably 1 to 3 mol %, based on the total number of moles of the carboxylic acid component (y).

[0026] From the viewpoint of chargeability, the number of moles of terephthalic acid in the carboxylic acid component (y) is preferably 70 mol % or more, more preferably 73 to 95 mol %, and even more preferably 75 to 93 mol %, based on the number of moles of the carboxylic acid component (y).

[0027] The reaction ratio of the alcohol component (x) to the carboxylic acid component (y), expressed as the molar ratio of hydroxyl groups to carboxyl groups {[OH] / [COOH]}, is preferably 1 / 2 to 2 / 1, more preferably 1 / 1.3 to 1.5 / 1, and even more preferably 1 / 1.2 to 1.4 / 1.

[0028] In the present invention, the polyester resin (A) can be produced in the same manner as known polyester production methods, for example, by reacting components containing an alcohol component (x) and a carboxylic acid component (y) in an inert gas (such as nitrogen gas) atmosphere. The ethylene glycol component contained in the alcohol component (x) may be an ethylene glycol component derived from PET (polyethylene terephthalate). The terephthalic acid component contained in the carboxylic acid component (y) may be a terephthalic acid component derived from PET (polyethylene terephthalate). In this case, the polyester resin (A) can be obtained by mixing the alcohol component (x), the carboxylic acid component (y), and PET, and carrying out a polycondensation reaction in the presence of a polymerization catalyst. The reaction temperature is preferably 100 to 280°C, more preferably 120 to 250°C, and even more preferably 140 to 235°C, from the viewpoint of ensuring that the polycondensation reaction is carried out. The reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours, from the viewpoint of ensuring that the polycondensation reaction is carried out reliably.

[0029] In this case, an esterification catalyst can be used if necessary. Examples of the esterification catalyst include tin-containing catalysts (e.g., dibutyltin oxide), antimony trioxide, titanium-containing catalysts (e.g., titanium alkoxides, potassium oxalate titanate, titanium terephthalate, titanium terephthalate alkoxides, catalysts described in JP-A-2006-243715 {titanium diisopropoxybis(triethanolaminate), titanium dihydroxybis(triethanolaminate), titanium monohydroxytris(triethanolaminate), titanyl bis(triethanolaminate), and intramolecular polycondensates thereof}, and catalysts described in JP-A-2007-11307 (titanium tributoxyterephthalate, titanium triisopropoxyterephthalate, titanium diisopropoxyditerephthalate, etc.), zirconium-containing catalysts (e.g., zirconyl acetate), and zinc acetate. Among the esterification catalysts, titanium-containing catalysts are preferred from the viewpoint of low-temperature fixability, and the catalysts described in JP-A Nos. 2006-243715 and 2007-11307 are more preferred.

[0030] In the present invention, the acid value of the polyester resin (A) is preferably from 10 to 25 mgKOH / g, more preferably from 15 to 23 mgKOH / g, from the viewpoints of chargeability and heat-resistant storage stability.

[0031] In the present invention, the glass transition temperature (Tg) of the polyester resin (A) is preferably from 40 to 70°C, more preferably from 50 to 60°C.

[0032] In the present invention, the weight average molecular weight (Mw) of the polyester resin (A) measured by gel permeation chromatography (GPC) is preferably 7,500 to 100,000, more preferably 7,500 to 50,000, and particularly preferably 7,500 to 10,000, from the viewpoints of low-temperature fixability and image strength.

[0033] <Terpene phenol resin (B)> The toner binder of the present invention contains a terpene phenol resin (B). In the present invention, the terpene phenol resin refers to a resin obtained by copolymerizing a terpene with a phenol. Examples of the terpene phenol resin (B) include YS Polyster G150, YS Polyster G125, YS Polyster U130, YS Polyster U-115, YS Polyster TH130, YS Polyster S145, YS Polyster T130, YS Polyster T145, and YS Polyster T160 (all manufactured by Yasuhara Chemical Co., Ltd.).

[0034] The glass transition temperature (Tg) of the terpene phenol resin (B) is 75 to 100°C, preferably 78 to 97°C, and more preferably 80 to 95°C. If the glass transition temperature of the terpene phenol resin (B) is lower than 75°C, the hot offset resistance may be poor, and if it exceeds 100°C, the low-temperature fixability may be poor.

[0035] <Toner binder> The toner binder of the present invention contains a polyester resin (A) and a terpene phenol resin (B).

[0036] The weight ratio of the polyester resin (A) to the terpene phenol resin (B) [(A) / (B)] is 90 / 10 to 70 / 30, preferably 90 / 10 to 75 / 25, and more preferably 90 / 10 to 80 / 20. If the weight ratio [(A) / (B)] is greater than 90 / 10, grindability becomes a problem, and if it is less than 70 / 30, charging becomes a problem.

[0037] The content of the polyester resin (A) is preferably 70 to 90% by weight, more preferably 75 to 90% by weight, based on the weight of the toner binder, from the viewpoint of grindability and chargeability. The content of the terpene phenol resin (B) is preferably 10 to 30% by weight, more preferably 10 to 25% by weight, based on the weight of the toner binder, from the viewpoint of grindability and chargeability.

[0038] The toner binder of the present invention may be produced in any manner as long as it contains the polyester resin (A) and the terpene phenol resin (B). For example, the toner binder can be produced by reacting components containing the alcohol component (x) and the carboxylic acid component (y) in an inert gas (nitrogen gas, etc.) atmosphere to produce the polyester resin (A), and then mixing the polyester resin (A) with the terpene phenol resin (B).

[0039] The toner binder of the present invention may be mixed with various additives such as other known binder resins for toners, colorants, release agents, charge control agents, and fluidizing agents, and used as a toner.

[0040] As the other binder resin for toner, amorphous resins are preferred, and examples thereof include amorphous vinyl resins, amorphous epoxy resins, amorphous polycarbonate resins, and amorphous polyurethane resins. In the present invention, "amorphous" means that when the transition temperature of a sample is measured using a differential scanning calorimeter, there is no peak top temperature of the endothermic peak.

[0041] The colorant preferably contains one or more selected from the group consisting of black colorants, blue colorants, red colorants, and yellow colorants. As the colorant, any dye, pigment, etc. used as a colorant for toner can be used. Specific examples include carbon black, iron black, Sudan Black SM, Fast Yellow G, Benzidine Yellow, Solvent Yellow (e.g., 21, 77, and 114), Pigment Yellow (e.g., 12, 14, 17, and 83), India First Orange, Irgasin Red, Paranitoaniline Red, Toluidine Red, Solvent Red (e.g., 17, 49, 128, 5, 13, 22, and 48·2), Disperse Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Solvent Blue (e.g., 25, 94, 60, and 15·3), Pigment Blue, Brilliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orasol Brown B, and Oil Pink OP. If necessary, magnetic powder (powder of ferromagnetic metals such as iron, cobalt and nickel, and compounds such as magnetite, hematite and ferrite) may be contained to also function as a colorant. The content of the colorant is preferably 1 to 40 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the total of the toner binder of the present invention and other toner binder resins. When a magnetic powder is used, the content of the magnetic powder is preferably 20 to 150 parts by weight, more preferably 30 to 120 parts by weight, based on 100 parts by weight of the total of the toner binder of the present invention and other toner binder resins.

[0042] Examples of the release agent include natural waxes (beeswax, carnauba wax, montan wax, etc.), petroleum waxes (paraffin wax, microcrystalline wax, petrolatum, etc.), synthetic waxes (Fischer-Tropsch wax, polyethylene wax, polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax, etc.), and synthetic ester waxes (fatty acid esters synthesized from fatty acids having 10 to 30 carbon atoms and alcohols having 10 to 30 carbon atoms), and it is preferable to contain one or more types selected from the group consisting of these release agents. The content of the release agent is preferably 30 parts by weight or less, more preferably 0.5 to 20 parts by weight, and even more preferably 1 to 10 parts by weight, relative to 100 parts by weight of the total of the toner binder of the present invention and other toner binder resins.

[0043] The melting point of the release agent is preferably 40 to 90°C, more preferably 45 to 85°C, and particularly preferably 50 to 80°C, from the viewpoint of low-temperature fixability.

[0044] The kinematic viscosity of the release agent at 100°C is preferably 3 to 20 mm from the viewpoint of low-temperature fixability. 2 / s, and more preferably 4 to 19 mm 2 / s, particularly preferably 5 to 18 mm 2 / s. The kinematic viscosity at 100°C can be measured by the method of JIS K2283:2000.

[0045] The charge control agent may be either a positively chargeable charge control agent or a negatively chargeable charge control agent, and examples thereof include nigrosine dyes, triphenylmethane dyes having a tertiary amine as a side chain, quaternary ammonium salts, polyamine resins, imidazole derivatives, quaternary ammonium base-containing polymers, metal-containing azo dyes, copper phthalocyanine dyes, salicylic acid metal salts, boron complexes of benzilic acid, sulfonic acid group-containing polymers, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers. The content of the charge control agent is preferably 0 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 0.5 to 7.5 parts by weight, relative to 100 parts by weight of the total of the toner binder and binder resin of the present invention.

[0046] Examples of the fluidizing agent include silica, titania, alumina, fatty acid metal salts, silicone resin particles, and fluororesin particles, and two or more of them may be used in combination. Silica is preferred from the viewpoint of toner charging properties. Furthermore, the silica is preferably hydrophobic from the viewpoint of toner transfer properties. The content of the fluidizing agent may be preferably 0 to 10 parts by weight, more preferably 0 to 5 parts by weight, and even more preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the total of the toner binder of the present invention and other toner binder resins.

[0047] The total weight of additives such as colorants, release agents, charge control agents, and fluidizing agents may be 3 to 70% by weight, preferably 4 to 58% by weight, and more preferably 5 to 50% by weight, based on the toner weight. By ensuring that the composition ratio of the toner is within the above range, it is possible to easily obtain toner with good charging properties.

[0048] The volume average particle size (D50) of the toner is preferably from 1 to 15 μm, more preferably from 2 to 10 μm, and particularly preferably from 3 to 7 μm.

[0049] The method for producing the toner is not particularly limited, and the toner may be obtained by a known kneading and pulverization method, a suspension polymerization method described in JP-B No. 10231 / 1961, JP-A No. 53856 / 1984, and JP-A No. 61842 / 1984, an emulsion polymerization method typified by a soap-free polymerization method in which a toner is produced by directly polymerizing a monomer in the presence of a water-soluble polymerization initiator that is soluble in the monomer, an interfacial polymerization method such as a microcapsule production method, an in-situ polymerization method, a coacervation method, an association polymerization method in which at least one type of fine particles are aggregated to obtain particles of a desired particle size as disclosed in JP-A Nos. 106473 / 1987 and 186253 / 1988, a dispersion polymerization method characterized by monodispersity, a solution suspension method in which necessary resins are dissolved in a water-insoluble organic solvent and then converted into a toner in water, or a method in which the toner is dispersed in carbon dioxide in a supercritical state.

[0050] For example, when a toner is obtained by a kneading and pulverizing method, the components constituting the toner, excluding the fluidizing agent, are dry-blended using a Henschel mixer, Nauta mixer, Banbury mixer, or the like, and then melt-kneaded using a continuous mixing device such as a twin-screw kneader, extruder, continuous kneader, or three-roll mill, and then coarsely pulverized using a mill or the like, and finally atomized using an airflow pulverizer, or the like, and further the particle size distribution is adjusted using a classifier such as an elbow jet to produce fine particles with a volume average particle size (D50) of 4 to 12 μm, and then the fluidizing agent can be mixed in a mill or the like to produce the toner.

[0051] For example, when a toner is obtained by a solution suspension method, the components constituting the toner except for the fluidizing agent are dissolved or dispersed in an organic solvent to form an oil phase, and then the oil phase is mixed with an aqueous phase containing a surfactant to form fine particles, and the organic solvent is then removed from the mixture of the oil phase and the aqueous phase, and the toner particles are then separated and classified, and finally the fluidizing agent is mixed to produce the toner.

[0052] The toner using the toner binder of the present invention is fixed to a support (paper, polyester film, etc.) by a copier, printer, etc. to form a recording material. As a method for fixing to a support, a known heat roll fixing method, flash fixing method, etc. can be applied.

[0053] The toner using the toner binder of the present invention can be preferably used for developing electrostatic images or magnetic latent images in electrophotography, electrostatic recording, electrostatic printing, etc. It can be more preferably used for developing full-color electrostatic images or magnetic latent images. [Example]

[0054] The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[0055] The physical properties of the polyester resin, amorphous polyester resin, toner, etc. were measured by the following methods.

[0056] <Weight average molecular weight (Mw)> The weight average molecular weight (Mw) was measured under the following conditions using a sample solution obtained by dissolving the polyester resin (A) in tetrahydrofuran (THF) and filtering off the insoluble matter with a glass filter. Equipment: Tosoh Corporation HLC-8120 Column: TSK GEL GMH6 (2 columns) (Tosoh Corporation) Measurement temperature: 40℃ Sample solution: 0.25 wt% THF solution Solution injection volume: 100μl Detector: Refractive index detector Standard substance: 12 standard polystyrenes (TSK standard POLYSTYRENE) manufactured by Tosoh Corporation (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000)

[0057] <Acid value> The acid value was measured according to the method specified in JIS K0070: 1992. However, the solvent used for measuring the acid value was a mixed solvent of acetone, methanol, and toluene (weight ratio of acetone:methanol:toluene=12.5:12.5:75).

[0058] <Glass transition temperature (Tg)> Measurement was carried out using a differential scanning calorimeter (DSC Q20, manufactured by TA Instruments) according to the method (DSC method) specified in ASTM D3418-82 under the following conditions. (1) Heat from 30°C to 150°C at 20°C / min (2) Hold at 150°C for 10 minutes (3) Cool to -35°C at 20°C / min (4) Keep at -35°C for 10 minutes (5) Heat up to 150°C at 20°C / min (6) The differential scanning calorimetric curve measured in the process of (5) was analyzed to determine the glass transition temperature.

[0059] <Production Example 1> [Synthesis of Polyester Resin (A1)] A reactor equipped with a condenser, stirrer, and nitrogen inlet was charged with 70 parts by weight of ethylene glycol, 171 parts by weight of propylene glycol, 236 parts by weight of bisphenol A·PO 3-mol adduct (Sanyo Chemical Industries, Ltd., "Hymer BP-3P"), 544 parts by weight of terephthalic acid, 25 parts by weight of sodium dimethyl isophthalate-5-sulfonate, and 2 parts by weight of tetrabutoxy titanate as a condensation catalyst. The mixture was heated to 220°C under a reduced pressure of 0.5 to 2.5 kPa and reacted for 20 hours while distilling off the resulting water and methanol. The temperature was then cooled to 180°C, and 91 parts by weight of succinic acid was added. The mixture was reacted under a reduced pressure of 0.5 to 2.5 kPa. When the acid value reached 20 mg KOH / g, the mixture was removed using a steel belt cooler. The removed resin was pulverized into particles to obtain polyester resin (A1). The polyester resin (A1) had a glass transition temperature (Tg) of 52.5°C, a weight average molecular weight (Mw) of 7500, and an acid value of 20 mgKOH / g.

[0060] <Production Example 2> [Synthesis of Polyester Resin (A2)] A reactor equipped with a condenser, stirrer, and nitrogen inlet was charged with 73 parts by weight of ethylene glycol, 180 parts by weight of propylene glycol, 13 parts by weight of glycerin, 182 parts by weight of bisphenol A·PO 2-mol adduct (Sanyo Chemical Industries, Ltd., "Hymer BP-2P"), 660 parts by weight of terephthalic acid, and 2 parts by weight of tetrabutoxy titanate as a condensation catalyst. The mixture was heated to 220°C under a reduced pressure of 0.5 to 2.5 kPa and reacted for 20 hours while distilling off the resulting water. The temperature was then cooled to 180°C, and 36 parts by weight of succinic acid was added. The mixture was reacted under a reduced pressure of 0.5 to 2.5 kPa. When the acid value reached 18 mg KOH / g, the mixture was removed using a steel belt cooler. The removed resin was pulverized into particles to obtain polyester resin (A2). The glass transition temperature (Tg), weight average molecular weight (Mw), and acid value of the resulting polyester resin are shown in Table 1.

[0061] <Production Example 3> [Synthesis of Polyester Resin (A3)] A pressurizable reactor was charged with 473 parts by weight of propylene glycol, 7 parts by weight of glycerin, 598 parts by weight of flake-form PET resin, 26 parts by weight of sodium 5-sulfoisophthalate dimethyl ester, 288 parts by weight of bisphenol A·PO 3-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-3P"), and 2 parts by weight of tetrabutoxy titanate, and the mixture was stirred at 220°C and 0.1 to 0.3 MPaG for 5 hours to carry out a depolymerization reaction (closed transesterification reaction). The mixture was then cooled to 180°C, 88 parts by weight of succinic acid was added, and the temperature was raised to 220°C while the pressure was reduced to 0.5 to 2.5 kPa to remove ethylene glycol, propylene glycol, methanol, and water. When the acid value reached 23 mg KOH / g, the mixture was removed using a steel belt cooler to obtain polyester resin (A3). The amounts of ethylene glycol, propylene glycol, methanol, and water recovered by distillation were 133 parts by weight, 325 parts by weight, 6 parts by weight, and 14 parts by weight, respectively. The glass transition temperature (Tg), weight-average molecular weight (Mw), and acid value of the resulting polyester resin are shown in Table 1.

[0062] <Production Example 4> [Synthesis of Polyester Resin (A4)] A polyester resin (A4) was obtained in the same manner as in Production Example 1, except that the raw materials shown in Table 1 were used. The glass transition temperature (Tg), weight average molecular weight (Mw), and acid value of the obtained polyester resin are shown in Table 1.

[0063] <Production Example 5> [Synthesis of Polyester Resin (A5)] A polyester resin (A5) was obtained in the same manner as in Production Example 1, except that the raw materials shown in Table 1 were used. The glass transition temperature (Tg), weight average molecular weight (Mw), and acid value of the obtained polyester resin are shown in Table 1.

[0064] Comparative Production Example 1 [Synthesis of Polyester Resin (RA1)] A reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube was charged with 10 parts by weight of glycerin, 260 parts by weight of bisphenol A·PO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-2P"), 200 parts by weight of bisphenol A·PO 3-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BP-3P"), 270 parts by weight of bisphenol A·EO 2-mol adduct (manufactured by Sanyo Chemical Industries, Ltd., "Hymer BPE-20"), 252 parts by weight of terephthalic acid, 45 parts by weight of adipic acid, and 2 parts by weight of tetrabutoxy titanate as a condensation catalyst. The mixture was reacted while being heated to 220°C under a reduced pressure of 0.5 to 2.5 kPa, and the reaction was continued for 20 hours while the produced water was distilled off. The temperature was cooled to 180°C, and 31 parts by weight of trimellitic anhydride was added. The mixture was reacted under a reduced pressure of 0.5 to 2.5 kPa. When the acid value reached 19 mgKOH / g, the mixture was removed using a steel belt cooler. The removed resin was pulverized into particles to obtain polyester resin (RA1). The glass transition temperature (Tg), weight average molecular weight (Mw), and acid value of the obtained polyester resin are shown in Table 1.

[0065] Comparative Production Example 2 [Synthesis of Polyester Resin (RA2)] A reactor equipped with a condenser, stirrer, and nitrogen inlet was charged with 170 parts by weight of propylene glycol, 29 parts by weight of ethylene glycol, 150 parts by weight of bisphenol A·PO 2-mol adduct (Sanyo Chemical Industries, Ltd., "Hymer BP-2P"), 178 parts by weight of bisphenol A·PO 3-mol adduct (Sanyo Chemical Industries, Ltd., "Hymer BP-3P"), 470 parts by weight of terephthalic acid, 67 parts by weight of trimellitic anhydride, and 2 parts by weight of tetrabutoxy titanate as a condensation catalyst. The mixture was heated to 220 °C under reduced pressure of 0.5 to 2.5 kPa and reacted for 20 hours while distilling off the resulting water. The mixture was then cooled to 180 °C, and 53 parts by weight of succinic acid was added. The mixture was reacted under reduced pressure of 0.5 to 2.5 kPa until the acid value reached 23 mg KOH / g, at which point the mixture was removed using a steel belt cooler. The extracted resin was pulverized into particles to obtain a polyester resin (RA2). The glass transition temperature (Tg), weight average molecular weight (Mw), and acid value of the obtained polyester resin are shown in Table 1.

[0066] Comparative Production Example 3 [Synthesis of Polyester Resin (RA3)] A polyester resin (RA3) was obtained in the same manner as in Production Example 1, except that the raw materials shown in Table 1 were used. The glass transition temperature (Tg), weight average molecular weight (Mw), and acid value of the obtained polyester resin are shown in Table 1.

[0067] [Table 1]

[0068] Example 1 [Production of Toner (TC1)] To 100 parts by weight of toner binder (TB1) containing 85 parts by weight of polyester resin (A) and 15 parts by weight of terpene phenol resin (B), 8 parts by weight of the pigment carbon black "MA-100" [manufactured by Mitsubishi Chemical Corporation] as a colorant, 5 parts by weight of paraffin wax "HNP-9" [manufactured by Nippon Seiro Co., Ltd.] as a release agent, and 1 part by weight of charge control agent "T-77" [manufactured by Hodogaya Chemical Co., Ltd.] were added, and the mixture was premixed using a Henschel mixer [manufactured by Mitsui Miike Chemical Engineering Co., Ltd., FM10B], and then kneaded in a twin-screw kneader [manufactured by Imoto Machinery Co., Ltd., IMC-9B20]. The resin particles were then finely pulverized using a supersonic jet mill, Labojet (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and classified using an air classifier (MDS-I, manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain resin particles with a volume average particle size of 5 μm and a particle size distribution of 1.2. The obtained resin particles (99 parts by weight) were mixed with 1 part by weight of a hydrophobic silica fluidizer, "Aerosil R972" (manufactured by Nippon Aerosil), in a sample mill to obtain toner (TC1).

[0069] <Examples 2 to 8, Comparative Examples 1 to 7> [Production of Toners (TC2) to (TC8) and Comparative Toners (RTC1) to (RTC7)] Toners (TC2) to (TC8) containing the toner binders (TB2) to (TB8) and comparative toners (RTB1) to (RTB7), respectively, and comparative toners (RTC1) to (RTC7), were obtained in the same manner as in Example 1, except that the formulations were as shown in Table 2.

[0070] The terpene phenol resins (B) listed in Table 2 are as follows: (B1): YS Polyster T145 (Yasuhara Chemical Co., Ltd., glass transition temperature: 83.0°C) (B2): YS Polyster G150 (Yasuhara Chemical Co., Ltd., glass transition temperature: 95.0°C) (B3): YS Polyster TH130 (Yasuhara Chemical Co., Ltd., glass transition temperature: 78.0°C) (RB1): YS Polyster T130 (Yasuhara Chemical Co., Ltd., glass transition temperature: 65.1°C) (RB2): YS Polyster T160 (Yasuhara Chemical Co., Ltd., glass transition temperature: 103.1°C)

[0071] The toners using the toner binders obtained in Examples 1 to 8 and Comparative Examples 1 to 7 were evaluated for low temperature fixability, hot offset resistance, pulverizability, and chargeability.

[0072] <Low temperature fixability> (MFT) Toner is applied to the paper at 0.6 mg / cm 2 The powder was evenly applied to the paper surface using a printer with the heat fixing unit removed. Other methods may be used as long as the powder can be evenly applied at the above weight density. The paper was then placed on a pressure roller at a fixing speed (heat roller peripheral speed) of 213 mm / sec and a fixing pressure (pressure roller pressure) of 10 kg / cm. 2 Under these conditions, the heating roller temperature was changed in 5°C increments over a range of 90 to 230°C, and fixed images were created at each temperature. Next, the presence or absence of cold offset in each fixed image was visually confirmed in ascending order of heating roller temperature, and the temperature at which cold offset no longer occurred is shown in Table 2 as low-temperature fixability (°C). The lower the temperature at which cold offset does not occur, the better the low-temperature fixability, and under these evaluation conditions, a temperature of 125° C. or less is generally preferred.

[0073] <Hot offset resistance> The presence or absence of hot offset on the fixed image was visually evaluated in the same manner as in the above-mentioned low-temperature fixing property evaluation method. The fixing roll temperature at which hot offset occurred was expressed as hot offset resistance (°C). The higher the temperature at which hot offset occurs, the better the hot offset resistance is, and under these evaluation conditions, a temperature of 200° C. or higher is generally preferred.

[0074] <Fixing width> The fixation width (°C) obtained by subtracting the low temperature fixability (°C) from the hot offset resistance (°C) is shown in Table 2. A larger fixation width indicates a better balance between low temperature fixability and hot offset resistance.

[0075] <Crushability> In the production of the toner, a mixture obtained by kneading in a twin-screw kneader was cooled and then pulverized and classified to a size of 8.6 mesh pass to 30 mesh on, and the resulting particles were used as particles for evaluating pulverizability. These particles for evaluating pulverizability were then finely pulverized using a supersonic jet pulverizer, Labo Jet, under the following conditions. Crushing pressure: 0.64 MPa Grinding time: 15 minutes Separator frequency: 150Hz Adjuster ring: 15mm Louver size: Medium The finely pulverized particles for evaluating grindability were not classified, and the volume average particle size (μm) was measured using a Coulter counter (trade name: Multisizer III (manufactured by Coulter)) to evaluate grindability. The volume average particle size (μm) is shown in Table 2 as the evaluation result of grindability. A smaller particle size means better grindability. Under these evaluation conditions, a volume average particle size of 8.0 μm or less is preferred.

[0076] <Chargeability (charge retention rate)> (1) 1 g of toner and 0.01 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed for 1 hour in a shaker. 0.5 g of this mixture and 20 g of ferrite carrier (F-150, manufactured by Powder Tech Co., Ltd.) were placed in a 50 mL glass bottle and conditioned at 23°C and 50% relative humidity for 8 hours. (2) The mixture was stirred by friction at 50 rpm for 10 minutes and 60 minutes using a Turbula shaker mixer, and the amount of charge after each time was measured using a blow-off charge amount measuring device (manufactured by Kyocera Corporation). Using the obtained values, "charge amount after 60 minutes of friction / charge amount after 10 minutes of friction" was calculated and used as the charge stability index. The charge stability index is shown in Table 2 as an evaluation result of the charge retention rate. A larger charge stability index indicates a better charge retention rate. Under these evaluation conditions, a charge stability index of 0.8 or more is preferred.

[0077] [Table 2]

[0078] As is clear from the evaluation results in Table 2, the toners (TC1) to (TC8) containing the toner binders (TB1) to (TB8) of Examples 1 to 8 were evaluated to have excellent low-temperature fixing properties, hot offset resistance, pulverizability, and charging properties. On the other hand, the toner binders (RTB1) to (RTB7) according to Comparative Examples 1 to 7 were poor in at least one of the performance items of low-temperature fixability, hot offset resistance, pulverizability, and chargeability. [Industrial Applicability]

[0079] The toner binder of the present invention can be suitably used as a toner binder for electrophotographic toners used in developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like. Furthermore, it is suitable for use as an additive for paints, an additive for adhesives, particles for electronic paper, and the like.

Claims

1. A toner binder comprising a polyester resin (A) obtained by polycondensing an alcohol component (x) and a carboxylic acid component (y), and a terpene phenol resin (B), the alcohol component (x) comprises ethylene glycol and propylene glycol; the carboxylic acid component (y) comprises terephthalic acid, the molar ratio of the ethylene glycol to the propylene glycol (EG / PG) is 0.4 to 1.0; the total number of moles of ethylene glycol and propylene glycol is 75 mol% or more based on the total number of moles of the alcohol component (x); The glass transition temperature of the terpene phenol resin (B) is 75 to 100°C, A toner binder in which the weight ratio [(A) / (B)] of the polyester resin (A) to the terpene phenol resin (B) is 90 / 10 to 70 / 30.

2. 2. The toner binder according to claim 1, wherein the carboxylic acid component (y) of the polyester resin (A) further comprises 5-sulfoisophthalic acid salt and / or a lower alkyl ester thereof.

3. 3. The toner binder according to claim 1, wherein the alcohol component (x) of the polyester resin (A) further contains an alkylene oxide adduct of bisphenol A.

4. A toner comprising the toner binder according to claim 1 or 2.

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