Binder for image forming materials

Abstract

To provide a binder for image forming materials that satisfies all requirements of heat resistance, hydrolysis resistance, and gloss, while maintaining low-temperature fixability and hot offset resistance. [Solution] A binder for image forming materials comprising an amorphous polyester resin (A) and a crystalline resin (C) obtained by polycondensation of an alcohol component and a carboxylic acid component, wherein the binder contains 20 to 60 mol% of ethylene glycol based on the total number of moles of the alcohol component, and 70 to 90 mol% of terephthalic acid based on the total number of moles of the carboxylic acid component, and the solubility parameter (SP value) of the amorphous polyester resin (A) is 10.5 to 11.5 (cal / cm³). 3 ) 1 / 2 A binder for image forming materials, wherein the peak top temperature (Tm) of the endothermic peak derived from the crystalline resin (C) is 50 to 90°C.

Description

[Technical Field]

[0001] This invention relates to a binder for image forming materials. [Background technology]

[0002] In recent years, with the development of electrophotographic systems, the demand for electrophotographic devices such as photocopiers and laser printers has increased rapidly, and the requirements for their performance have also become more sophisticated. For full-color electrophotography, conventional methods and apparatus are known that involve forming a latent image based on color image information on a latent image carrier such as an electrophotographic photoreceptor, developing the latent image with a toner of the corresponding color, then transferring the toner image onto a transfer material, repeating this image formation process, and finally heating and fixing the toner image on the transfer material to obtain a multi-color image.

[0003] For these processes to proceed smoothly, the toner must first maintain a stable charge level, and then have good adhesion to the paper. Furthermore, since the device has a heating element in the fixing section, the temperature rises within the device, so the toner must not block within the device.

[0004] Furthermore, in addition to promoting miniaturization, increased speed, and higher image quality of electrophotographic equipment, there is a strong demand for improved low-temperature fixing properties of toner from an energy-saving perspective, specifically by reducing energy consumption in the fixing process. Furthermore, many types of paper are now used as transfer materials, including recycled paper with large surface irregularities and coated paper with a smooth surface. To accommodate the surface properties of these transfer materials, fusers with wide nip widths, such as soft rollers and belt rollers, are preferred. However, widening the nip width increases the contact area between the toner and the fuser roller, causing a phenomenon known as high-temperature offset, where molten toner adheres to the fuser roller. Therefore, resistance to offset is a prerequisite. In addition to the above, multi-color images (full color) require a much higher gloss than black and white images (monochrome) for purposes such as reproducing photographs, and the toner layer of the resulting image must be smooth. Therefore, it is necessary to achieve high gloss while maintaining offset resistance and exhibiting low-temperature fixability, and there is a growing demand for high-gloss toner images across a wide working range.

[0005] Binders for image forming materials significantly affect the toner properties described above. While polystyrene resins, styrene-acrylic resins, polyester resins, epoxy resins, polyurethane resins, and polyamide resins are known, polyester resins have recently attracted particular attention due to their ease of balancing preservation and fixation properties.

[0006] As a method to broaden the fixing temperature range, a toner using a polyester resin containing an unsaturated carboxylic acid as a component has been proposed (Patent Document 1). However, while this method can prevent offset phenomena at high and low temperatures to some extent, it still does not fully meet the demands for stable image quality, high speed, and energy saving during continuous printing.

[0007] On the other hand, numerous toners using hybrid resins in which polyester and styrene-acrylic components are chemically bonded have been proposed (Patent Documents 2-6). However, while this method improves resistance to hot offset, electrostatic properties, and pulverization, its low-temperature fixation properties remain insufficient.

[0008] As described above, until now, there has been no binder for image forming materials that satisfies all requirements of heat resistance, image quality stability, and gloss while maintaining low-temperature fixability and hot offset resistance. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-003985 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-286562 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-235362 [Patent Document 4] Japanese Patent Application Laid-Open No. 2008-009171 [Patent Document 5] Japanese Patent Application Laid-Open No. 2010-128466 [Patent Document 6] Japanese Patent Application Laid-Open No. 2006-047585 [Summary of the Invention] [Problems to be Solved by the Invention]

[0010] An object of the present invention is to provide a binder for an image forming material that satisfies all of heat storage stability, image quality stability, and glossiness while maintaining low-temperature fixing property and hot offset resistance. [Means for Solving the Problems]

[0011] As a result of intensive studies to solve these problems, the present inventors have reached the present invention. That is, the present invention is a binder for an image forming material containing an amorphous polyester resin (A) obtained by polycondensing an alcohol component and a carboxylic acid component and a crystalline resin (C), containing 20 to 60 mol% of ethylene glycol based on the total number of moles of the alcohol component, and containing 70 to 90 mol% of terephthalic acid based on the total number of moles of the carboxylic acid component, the solubility parameter (SP value) of the amorphous polyester resin (A) being 10.5 to 11.5 (cal / cm 3 ) 1 / 2 and the peak top temperature (Tm) of the endothermic peak derived from the crystalline resin (C) being 50 to 90°C, and the acid value of the polyester resin (A) being 25.0 mgKOH / g or less. [Effects of the Invention]

[0012] The present invention makes it possible to provide a binder for image forming materials that satisfies all requirements of heat resistance, image quality stability, and gloss, while maintaining low-temperature fixability and hot offset resistance. [Modes for carrying out the invention]

[0013] The binder for image-forming materials of the present invention comprises an amorphous polyester resin (A) and a crystalline resin (C) obtained by polycondensation of an alcohol component and a carboxylic acid component, wherein the binder contains 20 to 60 mol% of ethylene glycol based on the total number of moles of the alcohol component, and 70 to 90 mol% of terephthalic acid based on the total number of moles of the carboxylic acid component, and the solubility parameter (SP value) of the amorphous polyester resin (A) is 10.5 to 11.5 (cal / cm³). 3 ) 1 / 2 The binder for image forming materials is such that the peak top temperature (Tm) of the endothermic peak derived from the crystalline resin (C) is 50 to 90°C, and the acid value of the polyester resin (A) is 25.0 mg KOH / g or less. The binder for image forming materials of the present invention will be described below in order.

[0014] The binder for image-forming materials of the present invention comprises an amorphous polyester resin (A) and a crystalline resin (C) obtained by polycondensation of an alcohol component and a carboxylic acid component.

[0015] The amorphous polyester resin (A) may be either an unsaturated polyester resin or a saturated polyester resin, but a saturated polyester resin is preferable from the viewpoint of low-temperature fixation properties. These may be a single type or a combination of two or more types. In this invention, "amorphous" means that when the transition temperature of a sample is measured using the differential scanning calorimeter described below, there is no peak top temperature of the endothermic peak. Furthermore, "crystalline" means that in the differential scanning calorimeter (also called DSC measurement) described below, the DSC curve has a clear peak top temperature (Tm) of the endothermic peak. The peak top temperature of the endothermic peak of the crystalline resin is measured using a differential scanning calorimeter (e.g., "DSC210" [manufactured by Seiko Instruments Inc.]). The crystalline resin is heated from 20°C to 150°C at a rate of 10°C / min for the first heating, then cooled from 150°C to 0°C at a rate of 10°C / min, and then heated from 0°C to 150°C at a rate of 10°C / min for the second heating. The temperature at the top of the endothermic peak during the second heating process is defined as the peak top temperature of the endothermic peak of the crystalline resin. Furthermore, in this invention, an unsaturated polyester resin refers to a polyester resin having a radically reactive carbon-carbon double bond. Aromatic rings and heterocyclic double bonds are not considered when determining whether a polyester resin is unsaturated or saturated.

[0016] Amorphous polyester resin (A) contains ethylene glycol as its alcohol component. The amorphous polyester resin (A) may contain an alcohol component (x) in addition to ethylene glycol. Examples of alcohol components (x) include monools (x1), diols other than ethylene glycol (x2), and polyols with a valency of 3 or higher (x3). These may be a single type or a combination of two or more types.

[0017] Examples of monools (x1) include linear or branched alkyl alcohols having 1 to 30 carbon atoms (methanol, ethanol, isopropanol, 1-decanol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and lignoceryl alcohol, etc.). Of these saturated monools, preferred from the viewpoint of image intensity and heat resistance for storage are linear or branched alkyl alcohols having 8 to 24 carbon atoms, more preferably linear alkyl alcohols having 8 to 24 carbon atoms, and even more preferably dodecyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and lignoceryl alcohol.

[0018] Examples of diols (x2) include alkylene glycols with 3 to 36 carbon atoms (propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol, etc.) (x22), and alkylene ether glycols with 4 to 36 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol) Examples include polypropylene glycol and polytetramethylene ether glycol (x23), alicyclic diols having 6 to 36 carbon atoms (such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A) (x24), (poly)alkylene oxide adducts of the above alicyclic diols (preferably with an average number of added moles of 1 to 30) (x25), aromatic diols [monocyclic divalent phenols (e.g., hydroquinone) and bisphenols, etc.] (x26), and alkylene oxide (hereinafter sometimes abbreviated as AO) adducts of the above aromatic diols (preferably with an average number of added moles of 2 to 30) (x27).

[0019] The alkylene oxide adducts of the above-mentioned bisphenols are obtained by adding alkylene oxide to bisphenols. Examples of bisphenols include those represented by the following general formula (1).

[0020] HO-Ar-P-Ar-OH (1) [In the formula, P represents an alkylene group having 1 to 3 carbon atoms, -SO2-, -O-, -S-, or a direct bond, and Ar represents a phenylene group in which a hydrogen atom may be substituted with a halogen atom or an alkyl group having 1 to 30 carbon atoms.]

[0021] Specific examples of bisphenols include, for example, 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, and two or more of these can be used in combination.

[0022] Examples of alkylene oxides to be added to bisphenols include alkylene oxides having 2 to 5 carbon atoms, such as ethylene oxide (hereinafter, "ethylene oxide" may be abbreviated as EO), propylene oxide ("propylene oxide" may be abbreviated as PO), butylene oxide, tetrahydrofuran, and combinations of two or more of these.

[0023] Of these diols (x2), alkylene glycols having 3 to 36 carbon atoms (x22) and alkylene oxide adducts of aromatic diols (x27) are preferred from the viewpoint of low-temperature fixability and heat-resistant storage, alkylene oxide adducts of bisphenols (average number of added moles is preferably 2 to 30) are more preferred, alkylene oxide adducts of bisphenol A (average number of added moles is preferably 2 to 5) are even more preferred, and ethylene oxide adducts and / or propylene oxide adducts of bisphenol A (average number of added moles is preferably 2 to 3) are particularly preferred.

[0024] Examples of polyols with a valency of 3 or higher (x3) include aliphatic polyhydric alcohols with 3 to 36 carbon atoms and a valency of 3 or higher (x31), sugars and their derivatives (x32), AO adducts of aliphatic polyhydric alcohols (average number of added moles preferably 1 to 30) (x33), AO adducts of trisphenols (such as trisphenol PA) (average number of added moles preferably 2 to 30) (x34), and AO adducts of novolac resins (which include phenol novolac and cresol novolac, and have an average degree of polymerization preferably 3 to 60) (average number of added moles preferably 2 to 30) (x35).

[0025] Examples of aliphatic polyhydric alcohols (x31) with 3 to 36 carbon atoms and a valency of 3 or higher include alkane polyols and their intramolecular or intermolecular dehydrated products, such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, polyglycerin, and dipentaerythritol.

[0026] Examples of sugars and their derivatives (x32) include sucrose and methyl glucoside.

[0027] Among polyols with a valency of 3 or higher (x3), from the viewpoint of achieving both low-temperature fixability and resistance to hot offset, an AO adduct (average number of added moles is preferably 2 to 30) (x35) of an aliphatic polyhydric alcohol (x31) having 3 to 36 carbon atoms with a valency of 3 or higher and a novolac resin (which includes phenol novolac and cresol novolac, and the average degree of polymerization is preferably 3 to 60) is preferred.

[0028] As the alcohol component (x), a diol (x2) and a polyol (x3) with a valency of 3 or higher can be used in combination. When used in combination, the molar ratio of ethylene glycol and diol (x2) to polyol (x3) with a valency of 3 or higher [(EG+(x2)) / (x3)] is preferably 99 / 1 to 80 / 20, more preferably 98 / 2 to 85 / 15, and particularly preferably 97 / 3 to 90 / 10 from the viewpoint of low-temperature fixability and resistance to hot offset.

[0029] Amorphous polyester resin (A) contains terephthalic acid as its carboxylic acid component. The amorphous polyester resin (A) may contain a carboxylic acid component (y) in addition to terephthalic acid. Examples of the carboxylic acid component (y) include aromatic carboxylic acids other than terephthalic acid (y1) and aliphatic carboxylic acids (y2). One type of carboxylic acid component (y) may be used, or two or more types may be used in combination.

[0030] Examples of aromatic carboxylic acids (y1) include aromatic dicarboxylic acids with 8 to 36 carbon atoms (phthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, etc.) and aromatic polycarboxylic acids with 9 to 20 carbon atoms and a valency of 3 or higher (trimellitic acid and pyromellitic acid, etc.). Examples of aliphatic carboxylic acids (y2) include aliphatic dicarboxylic acids with 2 to 50 carbon atoms (oxalic acid, malonic acid, succinic acid, adipic acid, suberic acid, and sebacic acid, etc.), alicyclic dicarboxylic acids with 6 to 40 carbon atoms (dimeric acid (dimerized linoleic acid), etc.), and alkene dicarboxylic acids with 4 to 36 carbon atoms (alkenyl succinic acids such as dodecenyl succinic acid, maleic acid, fumaric acid, citraconic acid, and mesaconic acid, etc.).

[0031] As the carboxylic acid component (y), anhydrides of these carboxylic acids, lower alkyl (1-4 carbon atoms) esters (methyl esters, ethyl esters, isopropyl esters, etc.) may be used, or these carboxylic acids may be used in combination with other carboxylic acids.

[0032] Of these carboxylic acid components (y), from the viewpoint of achieving both low-temperature fixability and resistance to hot offset, preferred are trivalent or higher aromatic polycarboxylic acids having 9 to 20 carbon atoms, aliphatic dicarboxylic acids having 2 to 50 carbon atoms, and alkene dicarboxylic acids having 4 to 36 carbon atoms; more preferably are aliphatic dicarboxylic acids having 4 to 10 carbon atoms, alkenyl succinic acid, isophthalic acid, trimellitic acid, pyromellitic acid, and combinations thereof. Particularly preferred are adipic acid, dodecenyl succinic acid, trimellitic acid, and combinations thereof. Anhydrides and lower alkyl esters of these acids are equally preferred.

[0033] Amorphous polyester resin (A) may use polyester resins such as polyethylene terephthalate (hereinafter also referred to as PET) resin or their depolymers as raw materials. For example, recycled PET resin may be used, and PET resin recovered from the market (hereinafter referred to as recovered PET resin) may be used. Examples of recovered PET resin include PET bottles and PET films.

[0034] The total charging ratio of alcohol components and carboxylic acid components in amorphous polyester resin (A) is preferably 1 / 2 to 2 / 1, more preferably 1 / 1.3 to 1.5 / 1, and even more preferably 1 / 1.2 to 1.4 / 1, in terms of the equivalent ratio (molar ratio) of hydroxyl groups to carboxyl groups ([OH] / [COOH]).

[0035] The ethylene glycol content of the alcohol component of amorphous polyester resin (A) is 20 to 60 mol%, preferably 30 to 50 mol%, and more preferably 35 to 45 mol%, based on the total number of moles of alcohol components. If the ethylene glycol content is less than 20 mol%, the hot offset resistance deteriorates, and if it exceeds 60 mol%, the low-temperature fixability and hydrolysis resistance deteriorate.

[0036] In amorphous polyester resin (A), the content of alcohol components other than ethylene glycol is preferably 40 to 80 mol%, more preferably 50 to 70 mol%, and even more preferably 55 to 65 mol%, based on the total number of moles of alcohol components.

[0037] In amorphous polyester resin (A), the terephthalic acid content among the carboxylic acid components is 70 to 90 mol%, preferably 74 to 86 mol%, and more preferably 77 to 83 mol%, based on the total number of moles of carboxylic acid components. If the terephthalic acid content is less than 70 mol%, the heat resistance to storage deteriorates, and if it exceeds 90 mol%, the hydrolysis resistance deteriorates.

[0038] In amorphous polyester resin (A), the content of carboxylic acid components other than terephthalic acid is preferably 10 to 30 mol%, more preferably 14 to 26 mol%, and even more preferably 17 to 23 mol%, based on the total number of moles of carboxylic acid components.

[0039] In the binder for image-forming materials of the present invention, the peak top molecular weight (Mp) of the amorphous polyester resin (A) in gel permeation chromatography (GPC) is preferably 3,000 to 10,000, and more preferably 4,000 to 8,000, from the viewpoint of low-temperature fixability, hot offset resistance, and heat-resistant storage.

[0040] In the present invention, the peak-top molecular weight (Mp), number-average molecular weight (hereinafter sometimes abbreviated as Mn), and weight-average molecular weight (hereinafter sometimes abbreviated as Mw) of the amorphous polyester resin (A) can be measured using GPC under the following conditions. Equipment (example): HLC-8120 manufactured by Tosoh Corporation Column (example): TSK GEL GMH6 (2 pieces) [Manufactured by Tosoh Corporation] Measurement temperature: 40℃ Sample solution: 0.25% by weight THF solution Solution injection volume: 100μL Detection device: Refractive index detector Reference material: 12 samples of standard polystyrene (TSKstandard POLYSTYRENE) manufactured by Tosoh Corporation (molecular weights: 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) To measure the molecular weight, the sample is dissolved in THF to a concentration of 0.25% by weight, and the undissolved portion is filtered out using a glass filter to obtain the sample solution.

[0041] In the binder for image forming materials of the present invention, the glass transition temperature (Tg) of the amorphous polyester resin (A) is A The temperature is preferably between 50 and 70°C. Tg A If the temperature is 70°C or below, the low-temperature fixing properties will be good, and if it is 50°C or above, the heat-resistant storage properties will be good. Note that the glass transition temperature (Tg) of amorphous polyester resin (A) A) can be measured by the method specified in ASTM D3418-82 (DSC method) using, for example, a DSC Q20 manufactured by TA Instruments Co., Ltd.

[0042] The acid value of the amorphous polyester resin (A) is 25.0 mgKOH / g or less, preferably 5 to 25 mgKOH / g, more preferably 5 to 15 mgKOH / g. When it exceeds 25 mgKOH / g, the heat resistance during storage and the image quality stability deteriorate. The acid value of the amorphous polyester resin (A) can be measured by the method specified in JIS K0070:1992.

[0043] From the viewpoints of low-temperature fixing property and hydrolysis resistance, the hydroxyl value of the amorphous polyester resin (A) is preferably 60 mgKOH / g or less, more preferably 20 to 55 mgKOH / g, still more preferably 30 to 50 mgKOH / g. The hydroxyl value of the amorphous polyester resin (A) can be measured by the method specified in JIS K0070:1992.

[0044] The solubility parameter (SP value) of the amorphous polyester resin (A) is 10.5 to 11.5 (cal / cm 3 ) 1 / 2 and preferably 10.7 to 11.4, more preferably 10.8 to 11.2. (A)'s SP value is less than 10.5 (cal / cm 3 ) 1 / 2 , the hot offset resistance deteriorates, and when it exceeds 11.5 (cal / cm 3 ) 1 / 2 , the low-temperature fixing property and hydrolysis resistance deteriorate. Examples of the method for adjusting the SP value of (A) include methods such as reducing the acid value of (A), reducing the hydroxyl value of (A), lowering the ester group concentration of (A), and increasing the weight average molecular weight of (A). The SP value of (A) can be reduced by the above methods. The SP value in this invention is the value at 25°C calculated using the method described on pages 151-154 of Volume 14 of Polymer Engineering and Science by Robert F Fedors et al.

[0045] The flow softening point (°C) of amorphous polyester resin (A) is preferably 120°C or lower, more preferably 90°C to 110°C, and even more preferably 95°C to 105°C, from the viewpoint of low-temperature fixability. The flow softening point of polyester resin (A) can be adjusted by controlling the molecular weight and glass transition temperature of the polyester resin, and by changing the ratio of trivalent or higher constituent components to increase or decrease the number of crosslinking points. Specifically, the flow softening point can be increased by increasing the molecular weight and glass transition temperature (Tg) of the polyester resin. In addition, the flow softening point can be increased by increasing the number of crosslinking points.

[0046] The flow softening point (°C) of amorphous polyester resin (A) was measured under the following conditions. <Method for measuring the flow softening point> Using a constant test force extrusion type capillary rheometer [for example, Shimadzu Corporation, Flow Tester CFT-500D], a 1g 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. A graph of the "plunger drop (flow value)" and "temperature" is drawn, and the temperature corresponding to half of the maximum value of the plunger drop is read from the graph. This value (the temperature when half of the sample has flowed out) is defined as the flow softening point (°C).

[0047] In the binder for image-forming materials of the present invention, the amorphous polyester resin (A) can be manufactured in the same manner as known polyesters. For example, the reaction can be carried out by reacting the constituent components in an inert gas (such as nitrogen gas) atmosphere at a reaction temperature of preferably 150 to 280°C, more preferably 160 to 250°C, and even more preferably 170 to 235°C. The reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours, from the viewpoint of ensuring a polycondensation reaction. Reducing the pressure is also effective in improving the reaction rate at the end of the reaction.

[0048] An esterification catalyst can be used as needed at this time. Examples of esterification catalysts include tin-containing catalysts (e.g., dibutyltin oxide), antimony trioxide, titanium-containing catalysts [e.g., titanium alkoxide, potassium titanate oxalate, titanium terephthalate, titanium alkoxide terephthalate, catalysts described in Japanese Patent Publication No. 2006-243715 {titanium diisopropoxybis(triethanolamine), titanium dihydroxybis(triethanolamine), titanium monohydroxytris(triethanolamine), titanylbis(triethanolamine) and their intramolecular polycondensates, etc.} and catalysts described in Japanese Patent Publication No. 2007-11307 (titanium tributoxyterephthalate, titanium triisopropoxyterephthalate and titanium diisopropoxyditeterephthalate, etc.)], zirconium-containing catalysts (e.g., zirconyl acetate), and zinc acetate. Among these, titanium-containing catalysts are preferred.

[0049] The binder for image forming materials of the present invention may further contain amorphous polyester resin (B) other than amorphous polyester resin (A). The alcohol component and carboxylic acid component constituting the polyester resin (B) other than amorphous polyester resin (A) are the same components as the alcohol component and carboxylic acid component listed as components of amorphous polyester resin (A).

[0050] As for the alcohol components constituting the polyester resin other than amorphous polyester resin (A), from among the alcohol components listed as components of amorphous polyester resin (A), alkylene glycols (x22) having 3 to 36 carbon atoms and alkylene oxide adducts (x27) of aromatic diols are preferred from the viewpoint of low-temperature fixability and heat-resistant storage, alkylene oxide adducts of bisphenols (average number of added moles is preferably 2 to 30) are more preferred, alkylene oxide adducts of bisphenol A (average number of added moles is preferably 2 to 5) are even more preferred, and ethylene oxide adducts and / or propylene oxide adducts of bisphenol A (average number of added moles is preferably 2 to 3) are particularly preferred.

[0051] The carboxylic acid components constituting the polyester resin other than amorphous polyester resin (A) are, from the viewpoint of achieving both low-temperature fixability and hot offset resistance, aromatic dicarboxylic acids having 8 to 36 carbon atoms, trivalent or higher aromatic polycarboxylic acids having 9 to 20 carbon atoms, aliphatic dicarboxylic acids having 2 to 50 carbon atoms, and alkene dicarboxylic acids having 4 to 36 carbon atoms. More preferably, these are aliphatic dicarboxylic acids having 4 to 10 carbon atoms, alkenyl succinic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, and combinations thereof. Particularly preferred are adipic acid, dodecenylsuccinic acid, terephthalic acid, trimellitic acid, and combinations thereof. Anhydrides and lower alkyl esters of these acids are equally preferred.

[0052] The peak-top molecular weight (Mp) of amorphous polyester resin (B) in gel permeation chromatography (GPC) is preferably 1,000 to 100,000, from the viewpoint of low-temperature fixability, hot offset resistance, and heat-resistant storage. The Mp, Mn, and Mw of amorphous polyester resin (B) can be measured under the same conditions as those for amorphous polyester resin (A).

[0053] The flow softening point (°C) of amorphous polyester resin (B) is preferably 120°C to 160°C, more preferably 130°C to 155°C, and even more preferably 140°C to 150°C, from the viewpoint of resistance to hot offset. The flow softening point of amorphous polyester resin (B) can be measured in the same way as that of amorphous polyester resin (A), and the method for adjusting the flow softening point is also the same as that for (A).

[0054] The acid value of amorphous polyester resin (B) is preferably 40 mg KOH / g or less, more preferably 30 mg KOH / g or less, and even more preferably 5 to 30 mg KOH / g, from the viewpoint of low-temperature fixability and hydrolysis resistance. The acid value of amorphous polyester resin (B) can be measured by the method specified in JIS K0070:1992.

[0055] Glass transition temperature (Tg) of amorphous polyester resin (B) B From the viewpoint of low-temperature fixation and heat-resistant storage, the temperature is preferably 50 to 70°C. Furthermore, the glass transition temperature (Tg) of amorphous polyester resin (B) B This can be measured, for example, using a DSC Q20 manufactured by TA Instruments Co., Ltd., by the method specified in ASTM D3418-82 (DSC method).

[0056] The solubility parameter (SP value) of amorphous polyester resin (B) is 10.5 to 11.5 (cal / cm³). 3 ) 1 / 2 It is preferable that the SP value is 10.6 to 11.0, and even more preferably 10.7 to 10.9. The SP value of amorphous polyester resin (B) can be calculated in the same way as the SP value of amorphous polyester resin (A), and the method for adjusting the SP value is also the same as for (A).

[0057] When the binder for image forming materials of the present invention contains amorphous polyester resin (B), the weight ratio of amorphous polyester resin (A) to amorphous polyester resin (B) [(A) / (B)] is preferably 50 / 50 to 90 / 10, from the viewpoint of achieving both low-temperature fixability, hot offset resistance, and heat-resistant storage.

[0058] From the viewpoint of compatibility, the binder for image-forming materials of the present invention preferably has an absolute difference of 1.3 (cal / cm²) between the SP value of amorphous polyester resin (A) and the SP value of amorphous polyester resin (B). 3 ) 1 / 2 The following applies:

[0059] In the binder for image-forming materials of the present invention, the amorphous polyester resin (B) can be manufactured in the same manner as known polyesters. An esterification catalyst can be used as needed. The same esterification catalyst as that used for amorphous polyester resin (A) can be used.

[0060] The binder for image-forming materials of the present invention comprises a crystalline resin (C). The crystalline resin (C) is not limited as long as it is a crystalline resin. Examples of crystalline resin (C) include crystalline polyester resin (C1) and crystalline vinyl resin (C2).

[0061] Crystalline polyester resin (C1) is a crystalline polyester resin obtained by polycondensation of components containing an alcohol component and a carboxylic acid component. From the viewpoint of low-temperature fixability and heat-resistant storage, it is preferable that the crystalline polyester is obtained from two or more alcohol components and / or two or more carboxylic acid components. Furthermore, examples of alcohol components include diols and polyols with a valentity of three or higher, and examples of carboxylic acid components include dicarboxylic acids and polycarboxylic acids with a valentity of three or higher.

[0062] Examples of diols include linear aliphatic diols with 2 to 20 carbon atoms (ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,18-octadecanediol, 1,19-nonadecanediol, and 1,20-eicosanediol, etc.) and alicyclic diols with 6 to 36 carbon atoms (1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol) Examples include [5-norbornene-2,3-dimethanol, hydrogenated bisphenol A, spiroglycol, isosorbide and alkylene oxide adducts of the above alicyclic diols, etc.], and aromatic diols (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 and alkylene oxide adducts of the above aromatic diols, etc.).

[0063] Examples of polyols with a valency of 3 or higher include polyhydric aliphatic alcohols (alkane polyols and their intramolecular or intermolecular dehydrated products, e.g., glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, and polyglycerin), sugars and their esterified products, e.g., sucrose and methyl glucoside), AO adducts of trisphenols (trisphenol PA, etc.) (2 to 30 moles added), AO adducts of novolac resins (phenol novolac, cresol novolac, etc.) (2 to 30 moles added), and acrylic polyols [such as copolymers of hydroxyethyl (meth)acrylate and other vinyl monomers].

[0064] Of the above alcohol components, a linear aliphatic diol having 2 to 20 carbon atoms is preferred from the viewpoint of low-temperature fixability and heat-resistant storage, a linear aliphatic diol having 2 to 12 carbon atoms is more preferred, and a linear aliphatic diol having 6 to 12 carbon atoms is particularly preferred.

[0065] Examples of dicarboxylic acids include linear aliphatic dicarboxylic acids having 2 to 50 carbon atoms (such as succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, and 1,18-octadecanedicarboxylic acid), alicyclic dicarboxylic acids having 8 to 36 carbon atoms (such as 1,4-cyclohexanedicarboxylic acid), and aromatic dicarboxylic acids having 8 to 36 carbon atoms (such as phthalic acid, isophthalic acid, and terephthalic acid).

[0066] Examples of polycarboxylic acids with a valency of 3 or more include aromatic polycarboxylic acids with 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid).

[0067] Of the above carboxylic acid components, from the viewpoint of low-temperature fixability and heat-resistant storage, linear aliphatic dicarboxylic acids having 2 to 50 carbon atoms and aromatic dicarboxylic acids having 8 to 36 carbon atoms are preferred, more preferably linear aliphatic dicarboxylic acids having 2 to 12 carbon atoms and aromatic dicarboxylic acids having 8 to 10 carbon atoms are preferred, and particularly preferably linear aliphatic dicarboxylic acids having 2 to 12 carbon atoms are preferred.

[0068] In the present invention, it is preferable that 50 mol% or more of the total alcohol component used in the crystalline polyester resin (C1) is a linear aliphatic diol having 2 to 20 carbon atoms, more preferably 75 mol% or more, and more preferably 95 mol% or more.

[0069] In the present invention, it is preferable that 50 mol% or more of the total carboxylic acid components used in the crystalline polyester resin (C1) are linear aliphatic dicarboxylic acids having 2 to 50 carbon atoms, more preferably 75 mol% or more, and more preferably 95 mol% or more.

[0070] The reaction ratio between the alcohol component and the carboxylic acid component is preferably 1 / 2 to 2 / 1, more preferably 1 / 1.3 to 1.5 / 1, and even more preferably 1 / 1.2 to 1.4 / 1, in terms of the molar ratio of hydroxyl groups to carboxyl groups {[OH] / [COOH]}. The hydroxyl groups are derived from the alcohol component.

[0071] In the present invention, the crystalline polyester resin (C1) can be manufactured in the same manner as known polyester manufacturing methods. An esterification catalyst can be used as needed. The same type of esterification catalyst as the amorphous polyester resin (A) can be used.

[0072] Crystalline vinyl resin (C2) is a polymer containing (meth)acrylate (a) having 21 to 40 carbon atoms and a chain-like hydrocarbon group as a constituent monomer. The carbon number is the sum of the carbon number of the chain-like hydrocarbon group and the carbon number (3 or 4) constituting the (meth)acrylic acid ester. One type of (meth)acrylate (a) having 21 to 40 carbon atoms and a chain-like hydrocarbon group may be used alone, or two or more types may be used in combination. In this specification, (meth)acrylate means acrylate and / or methacrylate.

[0073] Examples of the (meth)acrylate (a) having a chain-like hydrocarbon group with 21 to 40 carbon atoms include (meth)acrylates having a straight-chain alkyl group (18 to 36 carbon atoms) [such as octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, montanyl (meth)acrylate, triacontyl (meth)acrylate, and dotriacontyl (meth)acrylate] and (meth)acrylates having a branched alkyl group (18 to 36 carbon atoms) [such as 2-decyltetradecyl (meth)acrylate]. Of these, from the viewpoint of achieving both heat resistance for storage, low-temperature fixing, and hot offset resistance of the toner, (meth)acrylate having a linear alkyl group (18 to 36 carbon atoms) is preferred, more preferably (meth)acrylate having a linear alkyl group (18 to 30 carbon atoms) is preferred, even more preferably octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, and triacontyl (meth)acrylate is preferred, and particularly preferred octadecyl acrylate, eicosyl acrylate, behenyl acrylate, and lignoceryl acrylate is preferred.

[0074] From the viewpoint of the toner's hot offset resistance and heat storage resistance, the crystalline vinyl resin (C2) may contain monomer (b) as a constituent monomer in addition to the (meth)acrylate (a) having 21 to 40 carbon atoms and having the chain-like hydrocarbon group described above. Monomer (b) may be used alone or in combination of two or more types.

[0075] Examples of monomer (b) include styrene monomers (b1), (meth)acrylic monomers (b2) excluding (meth)acrylates (a) having a chain-like hydrocarbon group and having 21 to 40 carbon atoms, vinyl ester monomers (b3), and monomers (b4) having at least one functional group selected from the group consisting of a nitrile group, a urethane group, a urea group, an amide group, an imide group, an allophanate group, and a biuret group, and an ethylenically unsaturated bond.

[0076] Examples of styrene monomers (b1) include styrene and alkylstyrenes with 1 to 3 carbon atoms in the alkyl group (e.g., α-methylstyrene and p-methylstyrene). Of these, styrene is preferred.

[0077] Examples of (meth)acrylic monomers (b2) include (meth)acrylic acid, alkyl (meth)acrylates with 1 to 16 carbon atoms in the alkyl group [methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate, etc.], hydroxyalkyl (meth)acrylates with 4 to 20 carbon atoms in the alkyl group [2-hydroxypropyl acrylate, 2-hydroxyethyl (meth)acrylate, and ethyl-2-(hydroxymethyl)acrylate, etc.], and 4 carbon atoms. Examples include (meth)acrylates containing up to 20 aminoalkyl groups [such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate], and esters of unsaturated carboxylic acids with 8 to 20 carbon atoms and polyhydric alcohols [such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate and polyethylene glycol di(meth)acrylate]. Of these, methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, and mixtures of two or more of these are preferred. In this specification, (meth)acrylic acid means acrylic acid and / or methacrylic acid.

[0078] Examples of vinyl ester monomers (b3) include aliphatic vinyl esters having 3 to 15 carbon atoms [such as vinyl acetate, vinyl propionate, and isopropenyl acetate] and aromatic vinyl esters having 9 to 15 carbon atoms [such as methyl-4-vinylbenzoate].

[0079] Monomers (b4) having at least one functional group selected from the group consisting of nitrile groups, urethane groups, urea groups, amide groups, imide groups, allophanate groups, and biuret groups, and an ethylenically unsaturated bond include monomers with nitrile groups and 6 or fewer carbon atoms (b41) [(meth)acrylonitrile, etc.], monomers with urethane groups (b42) [2-isocyanatoethyl (meth)acrylate, (meth)acrylic acid 2-[0-(1'-methylpropyl Examples include [(lydenamino)carboxyamino]ethyl, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate and 1,1-(bis(meth)acryloyloxymethyl)ethyl isocyanate, etc.], monomers having a urea group (b43), monomers having an amide group (b44), monomers having an imide group (b45), monomers having an allophanate group (b46), and monomers having a biuret group (b47). In this specification, the term "(meth)acrylonitrile" means "acrylonitrile" and / or "methacrylonitrile". Of these monomers (b4), the preferred monomer is a monomer (b41) having nitrile groups and 6 or fewer carbon atoms.

[0080] The crystalline vinyl resin (C2) may contain other monomers as constituent monomers other than the above-mentioned (meth)acrylate (a) and monomer (b) having chain-like hydrocarbon groups and having 21 to 40 carbon atoms, such as divinylbenzene and sodium alkylallyl sulfosuccinate.

[0081] From the viewpoint of crystallinity, the weight percentage of the (meth)acrylate (a) having chain hydrocarbon groups with 21 to 40 carbon atoms in the monomer constituting the crystalline vinyl resin (C2) is preferably 15 to 93% by weight, more preferably 20 to 90% by weight, and even more preferably 30 to 90% by weight, based on the weight of the crystalline vinyl resin (C2), in order to achieve a balance between low-temperature fixability, hot offset resistance, and heat storage resistance.

[0082] From the viewpoint of heat resistance and hot offset resistance, the weight ratio of monomer (b) in the monomer constituting the crystalline vinyl resin (C2) is preferably 7 to 85% by weight, more preferably 10 to 80% by weight, and even more preferably 10 to 70% by weight, based on the weight of the crystalline vinyl resin (C2).

[0083] In the binder for image forming materials of the present invention, the glass transition temperature (Tg) of the crystalline vinyl resin (C2) is... C2 The temperature is preferably between -35 and 47°C. Tg C2 If the temperature is 47°C or below, the low-temperature fixing properties will be good, and if it is -35°C or above, the heat-resistant storage properties will be good. Note that the glass transition temperature (Tg) of crystalline vinyl resin (C2) is... C2 ) is the Fox-Flory equation, 1 / Tg 12 This value is calculated by =φ(1) / Tg1 + φ(2) / Tg2. 12 φ(1) corresponds to the Tg in absolute temperature (unit K) of the crystalline vinyl resin (C2), Tg1 and Tg2 are the glass transition temperatures (unit K) of the homopolymers of the monomers constituting the crystalline vinyl resin (C2), and φ(2) are the weight percentages of the monomers constituting the crystalline vinyl resin (C2).

[0084] The glass transition temperature of the monomer homopolymer constituting crystalline vinyl resin (C2) is calculated using Polymer Design Tools software (DTW Associates, Inc., version 1.1).

[0085] The acid value of the crystalline vinyl resin (C2) is preferably 55 mg KOH / g or less from the viewpoint of low-temperature fixation. The acid value of crystalline vinyl resin (C2) is calculated by using the acid value of each monomer used in the polymerization of crystalline vinyl resin (C2) and the weight of each monomer, and then expressing the result as a weight percentage.

[0086] The crystalline vinyl resin (C2) in the binder for image-forming materials of the present invention can be produced by polymerizing a monomer composition containing a (meth)acrylate (a) having 21 to 40 carbon atoms and a chain-like hydrocarbon group, and a monomer (b) used as needed, by a known method (such as the method described in Japanese Patent Application Publication No. 5-117330). For example, it can be synthesized by a solution polymerization method in which the monomer is reacted with a radical reaction initiator (such as azobisisobutyronitrile) in a solvent (such as toluene). Furthermore, in the above solution polymerization method, producing the crystalline vinyl resin (C2) in the presence of an amorphous polyester resin (A) instead of a solvent is preferable from the viewpoint of achieving both pulverability and resistance to hot offset, as the crystalline vinyl resin (C2) can be uniformly crosslinked within the amorphous polyester resin (A).

[0087] The radical initiator (c) is not particularly limited and includes inorganic peroxides (c1), organic peroxides (c2), and azo compounds (c3). These radical initiators may also be used in combination.

[0088] The inorganic peroxide (c1) is not particularly limited, but examples include hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

[0089] The organic peroxide (C2) is not particularly limited, but examples include benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α,α-bis(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexine-3, acetyl peroxide, isobutyryl peroxide, octaninol peroxide, and decanolyl peroxide. Examples include lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, cumyl peroxyneodecanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl monocarbonate, and t-butyl peroxyacetate.

[0090] The azo compound (c3) is not particularly limited, but examples include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitride), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

[0091] Among these, organic peroxides (C2) are preferred because they have high initiator efficiency and do not produce toxic by-products such as cyanide compounds, and t-butylperoxy-2-ethylhexanoate and di-t-butyl peroxide are more preferred.

[0092] In the binder for image-forming materials of the present invention, the weight ratio [(A) / (C)] of amorphous polyester resin (A) to crystalline resin (C) is preferably 50 / 50 to 90 / 10, from the viewpoint of achieving both low-temperature fixability, hot offset resistance, and heat-resistant storage.

[0093] In the binder for image-forming materials of the present invention, it is preferable that the calcium element content is 10 to 4000 ppm based on the weight of the binder for image-forming materials, as measured by X-ray fluorescence. The calcium content in binders for image forming materials can be adjusted by the amount of calcium-containing compounds added during binder preparation. Examples of calcium-containing compounds include calcium carbonate, calcium bicarbonate, calcium chloride, calcium sulfate, calcium oxide, calcium phosphate, calcium hydroxide, calcium hydride, calcium acetate, aliphatic carboxylates of calcium, and aromatic carboxylates of calcium. Using polyester resin containing calcium reduces the amount of cyclic compounds. Reducing cyclic compounds improves the durability of the toner.

[0094] In this specification, a method for determining the calcium element content by fluorescent X-ray is described below. <Sample adjustment> A pressure molding method can be used to compress powders such as binders and toners for image forming materials into pellets. For example, a 5mm thick ring made of polyvinyl chloride resin can be filled with enough powder to form a small mound in the center, and then pressed with a press machine under a load of 10t to form pellets. Care should be taken to avoid contamination by other components, especially calcium. In particular, toner may contain calcium as an external additive. Therefore, by first ultrasonically cleaning the toner with methanol or similar to remove the external additive from the surface, and then performing surface analysis using STEM or similar methods to confirm that the external additive has been removed, the calcium content can be accurately measured. <Measurement Method> A calibration curve can be prepared using standard samples with known calcium element concentrations, and the analytical value can be determined from the X-ray intensity of the analytical sample. Alternatively, if the majority of the resin composition is known, the approximate content can be determined using the fundamental parameter method (FP method). However, except in cases where the contents of toner, etc., are unknown, the FP method is relatively inaccurate, so it is preferable to use a calibration curve method that can measure the calcium element concentration more accurately. <Measuring device> For example, it can be measured using an X-ray fluorescence analyzer (such as the Rigaku Supermini200).

[0095] The binder for image-forming materials preferably contains phosphorus in the range of 2 to 500 ppm based on the weight of the binder, as measured by X-ray fluorescence. The phosphorus content in binders for image forming materials can be adjusted by the amount of phosphorus-containing compounds added during the manufacturing of polyester resins. Furthermore, using polyester resin in a state containing phosphorus reduces thermal decomposition products and improves the toner charge retention rate, which is preferable. In this specification, the quantification of phosphorus content by X-ray fluorescence can be measured in the same manner as the quantification of calcium content.

[0096] The glass transition temperature (Tg) of the binder for image forming materials of the present invention is preferably 50 to 70°C from the viewpoint of low-temperature fixability and heat-resistant storage. When two or more types of resins are used, preferably at least one of the resins has a glass transition temperature (Tg) of 50 to 70°C. If the Tg of the binder for image forming materials is 70°C or lower, it exhibits good low-temperature fixation properties, and if it is 50°C or higher, it exhibits good heat resistance for storage. The glass transition temperature (Tg) is measured using the method specified in ASTM D3418-82 (DSC method) with a DSC Q20, for example, manufactured by TA Instruments Co., Ltd.

[0097] The acid value of the binder for image-forming materials of the present invention is preferably 10 to 30 mg KOH / g or less. The acid value of binders for image forming materials can be measured by the method specified in JIS K0070:1992.

[0098] The binder for image-forming materials of the present invention may contain THF-insoluble components. The content (by weight) of THF-insoluble components in the binder for image forming materials of the present invention is preferably 50% by weight or less, and more preferably 5 to 30% by weight, from the viewpoint of achieving both resistance to hot offset and low-temperature fixing properties.

[0099] The content (by weight) of THF-insoluble components in the binder for image forming materials of the present invention was determined by the following method. Add 50 mL of THF to 0.5 g of the sample and stir under reflux for 3 hours. After cooling, filter off the insoluble components using a glass filter, and dry the resin on the glass filter under reduced pressure at 80°C for 3 hours. The weight of the dried resin on the glass filter is taken as the weight of the THF-insoluble components, and the weight of the THF-soluble components is obtained by subtracting the weight of the THF-insoluble components from the weight of the sample, and the weight percentages of the THF-insoluble and THF-soluble components are calculated.

[0100] A method for manufacturing binders for image forming materials will be described. The binder for image forming materials is not particularly limited as long as it contains an amorphous polyester resin (A) and a crystalline resin (C). For example, when mixing the amorphous polyester resin (A), crystalline resin (C), amorphous polyester resin (B) if necessary, other resins and additives, the mixing method can be a generally known method, such as powder mixing, melt mixing and solvent mixing. In addition, the amorphous polyester resin (A), crystalline resin (C), amorphous polyester resin (B) used if necessary, other resins and additives may be mixed simultaneously when manufacturing the binder for image forming materials. Among these methods, melt mixing, which provides uniform mixing and does not require solvent removal, is preferred.

[0101] Examples of mixing equipment for powder mixing include Henschel mixers, Nauter mixers, and Banbury mixers. A Henschel mixer is preferred. Mixing equipment for melt-mixing includes batch-type mixing equipment such as reaction vessels and continuous-type mixing equipment. Continuous-type mixing equipment is preferred for uniform mixing at the appropriate temperature in a short time. Examples of continuous-type mixing equipment include static mixers, extruders, continuous kneaders, and three-roll mixers.

[0102] Methods for solvent mixing include dissolving the amorphous polyester resin (A) and crystalline resin (C) in a solvent (ethyl acetate, THF, acetone, etc.), homogenizing them, then desolventing and pulverizing them; or dissolving the amorphous polyester resin (A) and crystalline resin (C) in a solvent (ethyl acetate, THF, acetone, etc.), dispersing them in water, then granulating and desolventing them.

[0103] The binder for image forming materials of the present invention can be used in toner.

[0104] In addition to the binder for image forming materials of the present invention, the toner may optionally contain one or more known additives selected from colorants, release agents, charge control agents, and fluidizing agents.

[0105] As a coloring agent, all dyes and pigments used as coloring agents for toners can be used. For example, carbon black, iron black, Sudan black SM, First Yellow G, benzidine yellow, pigment yellow, India First Orange, Irgasine red, paranitroaniline red, toluidine red, carmine FB, pigment orange R, lake red 2G, rhodamine FB, rhodamine B lake, methyl violet B lake, phthalocyanine blue, pigment blue, brilliant green, phthalocyanine green, oil yellow GG, kayaset YG, orazole brown B, and oil pink OP are examples. The coloring agent may be any one of these alone, or a mixture of two or more. In addition, if necessary, magnetic powder (powder of ferromagnetic metals such as iron, cobalt, and nickel, or compounds such as magnetite, hematite, and ferrite) may be included, also serving as a coloring agent.

[0106] Preferred release agents have a flow softening point (T1 / 2) of 50 to 170°C as measured by a flow tester. Examples include low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene polyethylene copolymer, polyolefin wax, microcrystalline wax, paraffin wax, aliphatic hydrocarbon waxes such as Fischer-Tropsch wax and their oxides, carnauba wax, montane wax, sazole wax and their deoxidizing waxes, ester waxes such as fatty acid ester wax, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and mixtures thereof.

[0107] The flow softening point (T1 / 2) of the release agent was measured under the following conditions. <Method for measuring the flow softening point (T1 / 2)> Using a constant force extrusion capillary rheometer [for example, Shimadzu Corporation, Flow Tester CFT-500D], a 1g 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. A graph of the "plunger drop (flow value)" and "temperature" is drawn, and the temperature corresponding to half of the maximum value of the plunger drop is read from the graph. This value (the temperature when half of the sample has flowed out) is defined as the flow softening point (T1 / 2).

[0108] Examples of polyolefin waxes include (co)polymers of olefins (e.g., ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene, and mixtures thereof) [including those obtained by (co)polymerization and thermodeformable polyolefins], oxides of olefin (co)polymers by oxygen and / or ozone, maleic acid modified products of olefin (co)polymers [e.g., maleic acid and its derivatives (maleic anhydride, monomethyl maleate, monobutyl maleate, and dimethyl maleate, etc.) modified products], copolymers of olefins with unsaturated carboxylic acids [(meth)acrylic acid, itaconic acid, and maleic anhydride, etc.] and / or unsaturated carboxylic acid alkyl esters [(meth)acrylate (alkyl with 1 to 18 carbon atoms) esters and alkyl maleate (alkyl with 1 to 18 carbon atoms) esters, etc.], and sazole waxes.

[0109] Examples of higher alcohols include aliphatic alcohols with 30 to 50 carbon atoms, such as triacontanol. Examples of fatty acids include fatty acids with 30 to 50 carbon atoms, such as triacontanecarboxylic acid.

[0110] Examples of charge control agents include nigrosine dyes, triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salts, polyamine resins, imidazole derivatives, quaternary ammonium base-containing polymers, metal-containing azo dyes, copper phthalocyanine dyes, metal salicylate salts, boron complexes of benzyl acid, sulfonic acid group-containing polymers, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers.

[0111] Examples of fluidizing agents include colloidal silica, alumina powder, titanium dioxide powder, and calcium carbonate powder.

[0112] The content of the binder for image-forming materials in the toner is preferably 68.4 to 97.4% by weight, based on the weight of the toner. The colorant content is preferably 1 to 30% by weight, more preferably 3 to 10% by weight, based on the toner weight. The release agent content is based on the toner weight and is preferably 1 to 10% by weight. The charge control agent content is preferably 0.5 to 7.5% by weight, based on the toner weight. The fluidizing agent content is based on the toner weight and is preferably 0.1 to 4% by weight. Furthermore, the total amount of additives is preferably 2.6 to 31.6% by weight, based on the toner weight. By setting the toner composition ratio within the above range, it is possible to easily obtain a toner with good hot offset resistance, heat storage resistance, and image stability.

[0113] The toner may be obtained by any of the known methods, such as the kneading and grinding method, the emulsification and phase inversion method, and the polymerization method. For example, when obtaining toner by a kneading and grinding method, the components constituting the toner, excluding the fluidizer, are dry-blended, then melt-kneaded, coarsely ground, and finally micronized using a jet mill or the like, and further classified to obtain fine particles with a volume-average particle size (D50) of preferably 5 to 20 μm, after which the fluidizer is mixed in to produce the toner. The volume-average particle size (D50) is measured using a Coulter counter [for example, product name: Multisizer III [manufactured by Beckman Coulter, Inc.]].

[0114] Furthermore, when obtaining toner by the emulsification phase inversion method, the components constituting the toner, excluding the fluidizing agent, are dissolved or dispersed in an organic solvent, then emulsified by adding water, and subsequently separated and classified for production. The volume-average particle size of the toner is preferably 3 to 15 μm.

[0115] Toner is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and resin (acrylic resin, silicone resin, etc.) as needed, and used as a developer for electrical latent images. When carrier particles are used, the weight ratio of toner to carrier particles is preferably 1 / 99 to 99 / 1. Alternatively, electrical latent images can be formed by friction with a component such as a charged blade instead of using carrier particles. Furthermore, the toner does not need to contain carrier particles.

[0116] Toner is fixed to a support material (paper, polyester film, etc.) by a copier, printer, etc., to become a recording material. Methods for fixing to the support material include the known thermal roll fixing method and flash fixing method.

[0117] The toner using the binder for image forming materials of the present invention is used for developing electrostatic images or magnetic latent images in electrophotography, electrostatic recording, electrostatic printing, and the like. More specifically, it is used for developing electrostatic images or magnetic latent images that are particularly suitable for full color.

[0118] This specification discloses the following:

[0119] (1) The present disclosure relates to a binder for image forming materials comprising an amorphous polyester resin (A) and a crystalline resin (C) obtained by polycondensation of an alcohol component and a carboxylic acid component, wherein the binder contains 20 to 60 mol% of ethylene glycol based on the total number of moles of the alcohol component and 70 to 90 mol% of terephthalic acid based on the total number of moles of the carboxylic acid component, and the solubility parameter (SP value) of the amorphous polyester resin (A) is 10.5 to 11.5 (cal / cm³). 3 ) 1 / 2 The binder for image forming materials is such that the peak top temperature (Tm) of the endothermic peak derived from the crystalline resin (C) is 50 to 90°C, and the acid value of the polyester resin (A) is 25.0 mg KOH / g or less.

[0120] The present disclosure (2) is an image forming material binder according to the present disclosure (1), wherein the content of crystalline resin (C) in the image forming material binder is 1 to 15% by weight.

[0121] Disclosure (3) is an image-forming material binder according to Disclosure (1) or (2), wherein the calcium element content in the image-forming material binder is 10 to 4000 ppm as measured by X-ray fluorescence.

[0122] The present disclosure (4) is a binder for image forming materials according to any one of the present disclosures (1) to (3), wherein the flow softening point (°C) of the amorphous polyester resin (A) is 120°C or less. [Examples]

[0123] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0124] <Manufacturing Example 1> [Manufacturing of Amorphous Polyester Resin (A1)] In a pressurized reaction vessel, 68 parts by weight (40.7 mol%) of ethylene glycol and 412 parts by weight of recovered PET resin (equivalent to 71.5 mol% of ethylene glycol and 83.0 mol% of terephthalic acid) were added, and a depolymerization reaction (closed transesterification reaction) was carried out at 220°C for 2 hours with stirring to obtain the depolymer product. Next, the depolymer was cooled to 180°C, and 531 parts by weight (56.6 mol%) of bisphenol A·PO2 molar adduct, 97 parts by weight (15.0 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The temperature was raised to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 115 parts by weight (68.7 mol%) of ethylene glycol, and when the peak top molecular weight reached 6200, it was cooled to 175°C. Next, 11 parts by weight (2.0 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A1) was obtained. Note that the mol% represents the content of each alcohol component or each carboxylic acid component based on the total number of moles of the alcohol component or carboxylic acid component, and the same applies to the following production examples.

[0125] <Manufacturing Example 2> [Manufacturing of Amorphous Polyester Resin (A2)] In a pressurized reaction vessel, 308 parts by weight of recovered PET resin (equivalent to 60.5 mol% ethylene glycol and 71.4 mol% terephthalic acid), 591 parts by weight (71.3 mol%) of bisphenol A·PO2 molar adduct, 145 parts by weight (26.5 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The mixture was heated to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 47 parts by weight (31.8 mol%) of ethylene glycol, and the mixture was cooled to 175°C when the peak top molecular weight reached 6600. Next, 9 parts by weight (2.1 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A2) was obtained.

[0126] <Manufacturing Example 3> [Manufacturing of Amorphous Polyester Resin (A3)] In a pressurized reaction vessel, 91 parts by weight (47.6 mol%) of ethylene glycol and 520 parts by weight of recovered PET resin (equivalent to 79.0 mol% of ethylene glycol and 89.2 mol% of terephthalic acid) were added, and a depolymerization reaction (closed transesterification reaction) was carried out at 220°C for 2 hours with stirring to obtain the depolymer product. Next, the depolymer was cooled to 180°C, and 444 parts by weight (41.4 mol%) of bisphenol A·PO2 molar adduct, 67 parts by weight (9.0 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The temperature was raised to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 130 parts by weight (68.0 mol%) of ethylene glycol, and when the peak top molecular weight reached 6600, it was cooled to 175°C. Next, 9 parts by weight (1.8 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A3) was obtained.

[0127] <Manufacturing Example 4> [Manufacturing of Amorphous Polyester Resin (A4)] In a pressurized reaction vessel, 67 parts by weight (40.6 mol%) of ethylene glycol and 412 parts by weight of recovered PET resin (equivalent to 71.8 mol% of ethylene glycol and 77.1 mol% of terephthalic acid) were added, and a depolymerization reaction (closed transesterification reaction) was carried out at 220°C for 2 hours with stirring to obtain the depolymer product. Next, the depolymer was cooled to 180°C, and 531 parts by weight (56.9 mol%) of bisphenol A·PO2 molar adduct, 97 parts by weight (14.2 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The temperature was raised to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 115 parts by weight (69.2 mol%) of ethylene glycol, and when the peak top molecular weight reached 6200, it was cooled to 175°C. Next, 48 parts by weight (8.7 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A4) was obtained.

[0128] <Manufacturing Example 5> [Manufacturing of Amorphous Polyester Resin (A5)] In a pressurized reaction vessel, 100 parts by weight (59.7 mol%) of ethylene glycol, 326 parts by weight (83.0 mol%) of terephthalic acid, 531 parts by weight (56.4 mol%) of bisphenol A·PO2 molar adduct, 97 parts by weight (15.0 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The mixture was heated to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 27 parts by weight (16.1 mol%) of ethylene glycol, and when the peak top molecular weight reached 6300, it was cooled to 175°C. Next, 11 parts by weight (2.0 mol%) of trimellitic anhydride was added, and esterification was carried out at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A5) was obtained.

[0129] <Comparative Manufacturing Example 1> [Manufacturing of Amorphous Polyester Resin (A'1)] In a pressurized reaction vessel, 84 parts by weight (48.5 mol%) of ethylene glycol and 512 parts by weight of recovered PET resin (equivalent to 85.9 mol% of ethylene glycol and 97.6 mol% of terephthalic acid) were added, and a depolymerization reaction (closed transesterification reaction) was carried out at 220°C for 2 hours with stirring to obtain the depolymer product. Next, the depolymer was cooled to 180°C, and 547 parts by weight (56.3 mol%) of bisphenol A·PO2 molar adduct and 2 parts by weight of titanium diisopropoxybis(triethanolaminate) as a condensation catalyst were added. The temperature was raised to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 157 parts by weight (90.7 mol%) of ethylene glycol, and when the peak top molecular weight reached 6200, it was cooled to 175°C. Next, 11 parts by weight (2.4 mol%) of trimellitic anhydride was added, and esterification was carried out at atmospheric pressure at 175°C for 1 hour, after which it was removed to obtain amorphous polyester resin (A'1).

[0130] <Comparative Manufacturing Example 2> [Manufacturing of Amorphous Polyester Resin (A'2)] In a pressurized reaction vessel, 244 parts by weight of recovered PET resin (equivalent to 53.3 mol% ethylene glycol and 64.0 mol% terephthalic acid), 646 parts by weight (86.6 mol%) of bisphenol A·PO2 molar adduct, 162 parts by weight (33.0 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The mixture was heated to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 53 parts by weight (39.9 mol%) of ethylene glycol, and the mixture was cooled to 175°C when the peak top molecular weight reached 6500. Next, 9 parts by weight (3.0 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A'2) was obtained.

[0131] <Comparative Manufacturing Example 3> [Manufacturing of Amorphous Polyester Resin (A'3)] In a pressurized reaction vessel, 106 parts by weight (53.7 mol%) of ethylene glycol and 559 parts by weight of recovered PET resin (equivalent to 82.2 mol% of ethylene glycol and 92.0 mol% of terephthalic acid) were added, and a depolymerization reaction (closed transesterification reaction) was carried out at 220°C for 2 hours with stirring to obtain the depolymer product. Next, the depolymer was cooled to 180°C, and 427 parts by weight (38.5 mol%) of bisphenol A·PO2 molar adduct, 46 parts by weight (6.0 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The temperature was raised to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 147 parts by weight (74.4 mol%) of ethylene glycol, and when the peak top molecular weight reached 6600, it was cooled to 175°C. Next, 9 parts by weight (2.0 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A'3) was obtained.

[0132] <Comparative Manufacturing Example 4> [Manufacturing of Amorphous Polyester Resin (A'4)] In a pressurized reaction vessel, 67 parts by weight (40.3 mol%) of ethylene glycol and 412 parts by weight of recovered PET resin (equivalent to 72.0 mol% of ethylene glycol and 75.5 mol% of terephthalic acid) were added, and a depolymerization reaction (closed transesterification reaction) was carried out at 220°C for 2 hours with stirring to obtain the depolymer product. Next, the depolymer was cooled to 180°C, and 531 parts by weight (56.9 mol%) of bisphenol A·PO2 molar adduct, 97 parts by weight (13.9 mol%) of dodecenyl succinic anhydride, and 2 parts by weight of titanium diisopropoxybis(triethanol aminate) as a condensation catalyst were added. The temperature was raised to 220°C while the pressure was reduced to 0.5-2.5 kPa to remove 115 parts by weight (69.2 mol%) of ethylene glycol, and when the peak top molecular weight reached 6300, it was cooled to 175°C. Next, 58 parts by weight (10.6 mol%) of trimellitic anhydride was added, and the mixture was esterified at atmospheric pressure at 175°C for 1 hour. After removal, amorphous polyester resin (A'4) was obtained.

[0133] Table 1 shows the composition and physical properties of amorphous polyester resin (A) and a comparative amorphous polyester resin (A').

[0134] [Table 1]

[0135] <Manufacturing Example 6> [Manufacturing of Amorphous Polyester Resin (B1)] In a pressurized reaction vessel equipped with a stirrer, heating / cooling device, thermometer, air inlet tube, vacuum device, and water reduction device, 199 parts by weight of bisphenol A·PO2 molar adduct, 534 parts by weight of bisphenol A·PO3 molar adduct, 172 parts by weight of terephthalic acid, 67 parts by weight of adipic acid, and 6 parts by weight of trimellitic anhydride were added and stirred to homogenize. Then, 2 parts by weight of titanium diisopropoxybistriethanol laminate was added at 120°C and homogenized for 30 minutes. Esterilization under reduced pressure was carried out while increasing the temperature toward 227°C, and esterification under reduced pressure was carried out at 227°C for 5 hours while maintaining a pressure of 4 kPa or less, and it was confirmed that the acid value was 1 mg KOH / g or less. Then, it was cooled to 180°C, 79 parts by weight of trimellitic anhydride was charged, and the esterification reaction was carried out at atmospheric pressure for 1 hour, after which the temperature was increased under reduced pressure toward 205°C, and esterification under reduced pressure was carried out at 205°C. The material was removed when the flow softening point reached 140°C, yielding amorphous polyester resin (B1).

[0136] Table 2 shows the composition and physical properties of amorphous polyester resin (B).

[0137] [Table 2]

[0138] <Manufacturing Example 7> [Synthesis of Crystalline Polyester Resin (C1-1)] In a reaction vessel equipped with a condenser, heating and cooling device, thermometer, stirrer, and nitrogen inlet tube, 472 parts by weight of 1,12-dodecanediol, 529 parts by weight of dodecanedioic acid, and 1.5 parts by weight of titanium dihydroxybis(triethanolamine) as a condensation catalyst were added and the reaction was carried out at 170°C under a nitrogen stream for 8 hours while distilling off the water produced. Then, the reaction was carried out for 4 hours under a nitrogen stream while gradually increasing the temperature to 220°C and distilling off the water produced, and further under reduced pressure of 0.5 to 2.5 kPa, and the mixture was removed when the acid value reached 0.4 mg KOH / g. After the removed resin was cooled to room temperature, it was pulverized to form particles to obtain a crystalline resin (crystalline polyester resin) (C1-1). The peak top temperature of the endothermic peak, the amount of heat absorbed at the endothermic peak, the weight-average molecular weight, and the acid value of the obtained crystalline resin are shown in Table 3.

[0139] <Manufacturing Examples 8-11> [Synthesis of Crystalline Polyester Resins (C1-2)-(C1-5)] Crystalline resins (crystalline polyester resins) (C1-2) to (C1-5) were obtained in the same manner as in Production Example 7, except that the raw materials listed in Table 3 were used. The peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline polyester resins are shown in Table 3.

[0140] <Comparative Manufacturing Example 5> [Synthesis of Crystalline Polyester Resin (C'1-1)] Crystalline resin (crystalline polyester resin) (C'1-1) was obtained in the same manner as in Production Example 7, except that the raw materials listed in Table 3 were used. The peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline polyester resin are shown in Table 3.

[0141] [Table 3]

[0142] <Manufacturing Example 12> [Manufacturing of Crystalline Vinyl Resin (C2-1)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 30.0 parts by weight of behenyl acrylate [manufactured by NOF Corporation, hereafter the same], 3.0 parts by weight of styrene [manufactured by Idemitsu Kosan Co., Ltd., hereafter the same], 67.0 parts by weight of vinyl acetate [manufactured by Nippon Vinegar & Polyvinyl Acetate Co., Ltd., hereafter the same], 0.4 parts by weight of t-butyl peroxy-2-ethylhexanoate [Perbutyl O, manufactured by NOF Corporation, hereafter the same], and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C to carry out polymerization. After addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 95% or higher. Then, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain crystalline resin (crystalline vinyl resin) (C2-1). The peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C2-1) are shown in Table 4.

[0143] <Manufacturing Example 13> [Manufacturing of Crystalline Vinyl Resin (C2-2)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 60.0 parts by weight of behenyl acrylate, 3.0 parts by weight of acrylic acid, 18.0 parts by weight of styrene, 19.0 parts by weight of 2-hydroxyethyl acrylate [manufactured by NOF Corporation, hereafter the same], 0.5 parts by weight of di-t-butyl peroxide [Perbutyl D, manufactured by NOF Corporation, hereafter the same], and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C, and polymerization was carried out. After dropwise addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and an additional 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 95% or higher. Subsequently, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain a crystalline resin (crystalline vinyl resin) (C2-2). The peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C2-2) are shown in Table 4.

[0144] <Manufacturing Example 14> [Manufacturing of Crystalline Vinyl Resin (C2-3)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 90.0 parts by weight of behenyl acrylate, 6.0 parts by weight of vinyl acetate, 4.0 parts by weight of styrene, 0.3 parts by weight of di-t-butyl peroxide [perbutyl D], and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C, and polymerization was carried out. After addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and an additional 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 95% or higher. Then, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain a crystalline resin (crystalline vinyl resin) (C2-3). Table 4 shows the peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C2-3).

[0145] <Manufacturing Example 15> [Manufacturing of Crystalline Vinyl Resin (C2-4)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 86.0 parts by weight of stearyl acrylate [manufactured by Kyoei Co., Ltd., hereafter the same], 14.0 parts by weight of vinyl acetate, and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C, and polymerization was carried out. After addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 95% or more. Then, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain a crystalline resin (crystalline vinyl resin) (C2-4). Table 4 shows the peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C2-4).

[0146] <Manufacturing Example 16> [Manufacturing of Crystalline Vinyl Resin (C2-5)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 70.0 parts by weight of triacontyl acrylate, 14.0 parts by weight of 2-hydroxypropyl acrylate, 16.0 parts by weight of styrene, and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C, and polymerization was carried out. After addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 95% or higher. Then, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain a crystalline resin (crystalline vinyl resin) (C2-5). Table 4 shows the peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C2-5).

[0147] <Comparative Manufacturing Example 6> [Manufacturing of Crystalline Vinyl Resin (C'2-1)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 74.0 parts by weight of stearyl acrylate [manufactured by Kyoei Co., Ltd., hereafter the same], 14.0 parts by weight of vinyl acetate, 12.0 parts by weight of styrene, and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C, and polymerization was carried out. After addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 95% or more. Then, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain a crystalline resin (crystalline vinyl resin) (C'2-1). Table 4 shows the peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C'2-1).

[0148] <Comparative Manufacturing Example 7> [Manufacturing of Crystalline Vinyl Resin (C'2-2)] 113 parts by weight of xylene was placed in an autoclave, purged with nitrogen, and then heated to 170°C under stirring and in a sealed state. A mixed solution of 70.0 parts by weight of triacontyl acrylate, 16.0 parts by weight of vinyl acetate, 14.0 parts by weight of 2-hydroxypropyl acrylate, and 130 parts by weight of xylene was added dropwise over 3 hours while controlling the autoclave temperature to 170°C, and polymerization was carried out. After addition, the dropping line was washed with 8 parts by weight of xylene. After holding at the same temperature for another 0.5 hours, the reaction rate was checked after cooling to 70°C. Since the reaction rate was less than 95%, the temperature was raised again to 170°C, and 1.6 parts by weight of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate was 95% or higher. Then, desolvation was carried out at 170°C under reduced pressure of 0.5-2.5 kPa for 5 hours to obtain a crystalline resin (crystalline vinyl resin) (C'2-2). Table 4 shows the peak top temperature of the endothermic peak, weight-average molecular weight, and acid value of the obtained crystalline resin (C'2-2).

[0149] [Table 4]

[0150] <Example 1> [Manufacturing of Toner (T1)] Using a Henschel mixer [FM10B, manufactured by Mitsui Miike Chemical Machinery Co., Ltd.], amorphous polyester resin (A1), amorphous polyester resin (B1), and polyester resin (C1) were added according to the mixing ratio (parts by weight) shown in Table 5, and 0.06 parts by weight of calcium acetate (calcium element content of 152 ppm based on the weight of the binder for image forming materials) was pre-mixed to obtain a binder for image forming materials. Next, the binder for image forming materials was pre-mixed with a colorant, release agent, and charge control agent, and then kneaded in a twin-screw kneader [PCM-30, manufactured by Ikegai Co., Ltd.]. Then, after fine grinding using a supersonic jet pulverizer LabJet [manufactured by Nippon Pneumatic Mfg. Co., Ltd.], the material was classified using an airflow classifier [MDS-I, manufactured by Nippon Pneumatic Mfg. Co., Ltd.] to obtain toner particles with a particle size D50 of 7 μm. Next, 0.5 parts by weight of colloidal silica [Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.] was mixed with 100 parts by weight of toner particles in a sample mill to obtain toner (T1).

[0151] The colorants, release agents, and charge control agents listed in Tables 5-6 are as follows: Coloring agent: Carbon Black MA-100 [Manufactured by Mitsubishi Chemical Corporation] Release agent: Carnauba wax [manufactured by Toyo Adore Co., Ltd.] Charge control agent: T-77 [Manufactured by Hodogaya Chemical Co., Ltd.]

[0152] <Examples 2-17> [Manufacturing of toner (T2)-(T17)] Except for following the mixing ratio (parts by weight) in Table 5 or 6, a binder and toner for image forming materials were prepared in the same manner as in Example 1 to obtain toners (T2) to (T17).

[0153] <Examples 18-20> [Manufacturing of toner (T18)-(T20)] Except for changing the amount of calcium acetate added to 0 parts by weight, 0.004 parts by weight, and 1.5 parts by weight respectively, binders and toners for image forming materials were prepared in the same manner as in Example 3 to obtain toners (T18) to (T20).

[0154] <Comparative Examples 1-8> [Manufacturing of Toner (T'1)-(T'8)] Except for following the mixing ratio (parts by weight) in Table 6, the binder and toner for image forming material were prepared in the same manner as in Example 1 to obtain toners (T'1) to (T'8).

[0155] [Evaluation Method] The following describes the measurement and evaluation methods, including the criteria, for the low-temperature fixability, hot offset resistance, heat storage resistance, image quality stability, hydrolysis resistance, gloss, and tape peelability of the obtained toners (T1) to (T20) and (T'1) to (T'8). The evaluation results are shown in Tables 5 and 6.

[0156] <Low temperature retention> Toner is applied to the paper surface at a rate of 1.00 mg / cm². 2 The powder was spread evenly to achieve this. The method used to apply the powder to the paper involved using a printer with the heat fuser removed. This paper was passed through a soft roller at a fixing speed (heating roller peripheral speed) of 213 mm / second, with the heating roller temperature ranging from 100 to 200°C in 5°C increments. Next, the presence or absence of cold offset in the fixed image was visually inspected, and the temperature at which cold offset occurs (MFT) was measured. A lower cold offset generation temperature indicates superior low-temperature fixing performance. Under these evaluation conditions, the MFT temperature is generally preferably 125°C or lower.

[0157] <Hot offset resistance> Using the same method as described above for low-temperature fixing, toner was placed on the paper, and this paper was passed through a soft roller at a fixing speed (peripheral speed of the heating roller) of 213 mm / second, with the heating roller temperature ranging from 100 to 200°C in 5°C increments. Next, we visually inspected the fixed image for the presence or absence of hot offset and measured the temperature at which hot offset occurred. A higher temperature at which hot offset occurs indicates superior resistance to hot offset. Under these evaluation conditions, a temperature of 180°C or higher is preferable.

[0158] <Heat-resistant storage stability> 1 g of toner and 0.013 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed in a shaker for 1 hour. The mixture was placed in a sealed container and left to stand for 24 hours in an atmosphere of 50°C and 80% relative humidity. The coagulation properties were measured using a powder tester to evaluate the heat resistance and storage properties. A lower cohesion test value, determined by the method described below, indicates superior heat resistance and storage properties. Under these evaluation conditions, a cohesion level of 5% or less is preferable. Equipment: POWDER TESTER model PT-X (manufactured by Hosokawa Micron) Sieve mesh sizes: 355μm, 250μm, 150μm Vibration width: 1mm Vibration time: 30 seconds Operating procedure: Place the sieves on the powder tester's vibrating platform in the following order: top 355μm, middle 250μm, and bottom 150μm. Place 1g of toner on the top sieve and vibrate for 30 seconds with a vibration amplitude of 1mm. Measure the weight of the toner remaining on each sieve. Cohesiveness: Calculated from the weight of toner used for measurement and the weight of remaining toner after sieving. Cohesion degree (%)=(U / N+M / N×3 / 5+L / N×1 / 5)×100 U: Weight of the top layer, M: Weight of the middle layer, L: Weight of the bottom layer, N: Weight of the sample (1g)

[0159] <Image quality stability> 30g of toner and 800g of ferrite carrier (Powdertec Co., Ltd., f-150) were uniformly mixed to create a two-component developer. Using this developer, unfixed images developed with a commercially available copier [AR5030, Sharp Corporation] were fixed using the fixing unit of a commercially available full-color copier [LBP-2160, Canon Inc.] at a process speed of 80mm / sec. [Evaluation Criteria] ◎: Images remain in good condition even after 8,000 consecutive copies. ○: After 8,000 consecutive copies, slight degradation in image quality (white background smudges) is observed. △: After 8,000 consecutive copies, a clear deterioration in image quality is observed, including white streaks in addition to white stains on the background. Under these conditions, a score of ○ or higher is considered good.

[0160] <Hydrolysis resistance> One g of toner was placed in an open glass container and left to stand for 10 days in an atmosphere of 95°C and 95% relative humidity. The weight-average molecular weight and storage modulus (Pa) at 100°C were measured before and after the test using GPC (Glycerin-Proprietary Coherence) measurements to check for changes in weight-average molecular weight and storage modulus, and to evaluate whether hydrolysis had occurred. The GPC measurement and storage modulus (Pa) at 100°C were measured using the same method as for polymer (A). ◎: Changes in both weight-average molecular weight and storage modulus are less than ±5%. ○: The change in weight-average molecular weight is ±5% or more, but the change in storage elasticity is less than ±5%. △: Change of ±5% or more in both weight-average molecular weight and elastic modulus. Under these evaluation criteria, a score of ○ or higher is considered good.

[0161] <Glossiness> Using the same method as described above for low-temperature fixing, toner was placed on the paper and fixed. Next, a white cardboard sheet was placed under the toner-fixed paper, and the glossiness (%) of the printed image was measured at an incident angle of 60 degrees using a gloss meter (Horiba, Ltd., "IG-330") at 5°C intervals from temperatures above the cold offset occurrence temperature (MFT) to the temperature at which hot offset occurred. The highest glossiness (%) within that range was used as an indicator of the toner's glossiness. For example, if the glossiness is 10% at 120°C, 15% at 125°C, 20% at 130°C, and 18% at 135°C, then 20% at 130°C is the highest value, so 20% is adopted. The glossiness values ​​are shown in Tables 5-6 as indicators of glossiness. A higher gloss level indicates superior glossiness. Under these evaluation conditions, a gloss level of 10% or higher is considered good.

[0162] <Tape release properties> <Adhesion Strength> (Tape Peel Test) The fixing strength of the MFT-fixed image, created using the low-temperature adhesion evaluation described above, was evaluated by a tape peel test. After applying tape (3M's "Scotch Mending Tape") to the fixed image, the tape was peeled off, and the image density (ID) of the image attached to the tape was measured using a reflectance densitometer (product name "X-Rite model 404," manufactured by X-Rite). A smaller image density (numerical value) of the attached image indicates higher fixing strength. Under these evaluation conditions, a value of 0.2 or less is preferable.

[0163] [Table 5]

[0164] [Table 6]

[0165] As is clear from the evaluation results in Tables 5-6, the toners (T1) to (T20) in the examples all showed excellent results in all performance evaluations. On the other hand, the toners (T'1) to (T'8) in the comparative examples were poor in several performance items. [Industrial applicability]

[0166] The binder for image forming materials of the present invention maintains low-temperature fixability and hot offset resistance while exhibiting excellent heat resistance, image quality stability, hydrolysis resistance, and gloss, making it suitable for use as a toner for electrostatic image development in electrophotography, electrostatic recording, electrostatic printing, and the like. Furthermore, it is suitable for applications such as inkjet binders, paint additives, adhesive additives, and particles for electronic paper.

Claims

1. A binder for image forming materials comprising an amorphous polyester resin (A) and a crystalline resin (C) obtained by polycondensation of an alcohol component and a carboxylic acid component, wherein the binder contains 20 to 60 mol% of ethylene glycol based on the total number of moles of the alcohol component, and 70 to 90 mol% of terephthalic acid based on the total number of moles of the carboxylic acid component, and the solubility parameter (SP value) of the amorphous polyester resin (A) is 10.5 to 11.5 (cal / cm³). ３ ) １／２ A binder for image forming materials, wherein the peak top temperature (Tm) of the endothermic peak derived from the crystalline resin (C) is 50 to 90°C, and the acid value of the polyester resin (A) is 25.0 mg KOH / g or less.

2. The binder for image forming materials according to claim 1, wherein the content of crystalline resin (C) in the binder for image forming materials is 1 to 15% by weight.

3. The binder for image forming materials according to claim 1 or 2, wherein the calcium element content in the binder for image forming materials is 10 to 4000 ppm as measured by X-ray fluorescence.

4. The binder for image forming materials according to claim 1 or 2, wherein the flow softening point (°C) of the amorphous polyester resin (A) is 120°C or lower.

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