JP7638730B2 - Toner binder manufacturing method - Google Patents

Description

The present invention relates to a method for producing a toner binder.

In recent years, with the development of electrophotographic systems, the demand for electrophotographic devices such as copying machines and laser printers has increased rapidly, and the requirements for their performance have also become more sophisticated.

Conventionally, for full-color electrophotography, a method and apparatus have been known in which a latent image based on color image information is formed on a latent image carrier such as an electrophotographic photosensitive member, the latent image is developed with a toner of a corresponding color, and then the toner image is transferred onto a transfer material. After repeating such image forming steps, the toner image on the transfer material is heated and fixed to obtain a multi-color image.
To pass through these processes without any problems, the toner must first maintain a stable charge, and then must have good fixability to paper. In addition, the toner must not block in the device because the fixing section of the device has a heater, causing the temperature to rise inside the device.

Furthermore, in order to promote miniaturization, speedup, and image quality improvement of electrophotographic apparatuses, as well as to save energy by reducing the energy consumption in the fixing step, there is a strong demand for improving the low-temperature fixing property of toner.
Recently, many kinds of paper are used as transfer materials, such as recycled paper with large surface irregularities and coated paper with a smooth surface. To deal with the surface properties of these transfer materials, a fixing device with a wide nip width, such as a soft roller or a belt roller, is preferably used. However, when the nip width is widened, the contact area between the toner and the fixing roller increases, and the melted toner adheres to the fixing roller, which is called a high-temperature offset phenomenon, occurs, so hot offset resistance is required.

The toner binder has a significant effect on the toner characteristics described above. Known examples of toner binders include polystyrene resin, styrene-acrylic resin, polyester resin, epoxy resin, polyurethane resin, and polyamide resin. Recently, however, polyester resin has been attracting particular attention because it is easy to balance heat resistance and fixability.

As a method for expanding the fixing temperature range, a toner using a polyester resin containing an unsaturated carboxylic acid as a constituent has been proposed (Patent Document 1). Also, a polyester-vinyl composite resin in which a polyester resin containing an unsaturated carboxylic acid as a constituent is combined with a vinyl resin has been proposed (Patent Documents 2 and 3).
However, although these methods can prevent the offset phenomenon at high temperatures to some extent, the minimum fixing temperature is insufficient, and the demand for high speed and energy saving is not yet fully met. In addition, blocking occurs due to water absorption under high temperature and high humidity, so the water resistance is insufficient.

On the other hand, a toner using a crystalline vinyl resin as a material for lowering the minimum fixing temperature has been proposed (Patent Documents 4 and 5).
Although this method improves the low-temperature fixing property, the hot offset resistance at high temperatures is insufficient.

As a method for improving the minimum fixing temperature while maintaining hot offset resistance, a toner binder has been proposed in which a long-chain alkyl acrylate is polymerized to reduce the melt viscosity, and a polyester resin containing an unsaturated carboxylic acid as a constituent component is combined (Patent Document 6). However, with this method, decomposition products such as initiators generated when crosslinking the unsaturated carboxylic acid remain, resulting in odor generation and insufficient charge retention rate under high temperature and high humidity conditions.

As mentioned above, there has not been an excellent toner binder that satisfies all of the following requirements: image strength, heat resistance, water resistance, charge retention rate, durability, and odor, while maintaining low-temperature fixing ability and hot offset resistance.

JP 2017-003985 A JP 2015-135485 A JP 2018-054888 A JP 2007-193069 A International Publication No. 2018/110593 International Publication No. 2019/073731

The present invention aims to provide a toner binder that satisfies all of the following requirements: image strength, heat resistance, water resistance, charge retention rate, durability, and odor, while maintaining low-temperature fixing ability and hot offset resistance.

［一般式（１）中、Ｒ^１～Ｒ^３はそれぞれ独立に水素原子、アルキル基又はアリール基である。］
The present inventors have made extensive investigations and have arrived at the present invention. That is, the present invention is a method for producing a toner binder, comprising a step of reacting a polyester resin (A1) having an acid value of 1 mgKOH/g or more with an epoxy compound (E) in the presence of a resin (B) having an acid value of less than 1 mgKOH/g and a catalyst (F), in which the resin (B) is a polyester resin (B1) and/or a vinyl resin (B2), the vinyl resin (B2) is a crystalline vinyl resin that is a polymer containing, as a constituent monomer, a monomer (a) that is a (meth)acrylate having a chain hydrocarbon group and having 21 to 40 carbon atoms and/or a vinyl ester having a chain hydrocarbon group and having 21 to 40 carbon atoms, and the catalyst (F) is a compound represented by the following general formula (1):

[In general formula (1), R ¹ to R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group.]

The present invention makes it possible to provide a toner binder that is excellent in image strength, heat-resistant storage stability, water resistance, charge retention rate, durability, and odor while maintaining low-temperature fixing properties and hot offset resistance. In addition, it is possible to shorten the reaction time between the polyester resin (A1) and the epoxy compound (E), resulting in excellent manufacturability of the toner binder.

The method for producing a toner binder of the present invention includes a step of reacting a polyester resin (A1) having an acid value of 1 mgKOH/g or more with an epoxy compound (E) in the presence of a resin (B) having an acid value of less than 1 mgKOH/g and a catalyst (F).
Since the polyester resin (A1) and the epoxy compound (E) are reacted in the presence of the resin (B), the reaction product of the polyester resin (A1) and the resin (B), which generally have viscosity differences and composition differences that cannot be mixed uniformly, can be made into a uniform mixture, and a toner binder having a wide fixing temperature range can be obtained. In addition, since the polyester resin (A1) and the epoxy compound (E) are reacted in the presence of the catalyst (F), the reaction time is shortened, and side reactions such as the ester exchange reaction between the reaction product of the polyester resin (A1) and the resin (B) can be reduced, and the functional separation of low temperature fixing property and hot offset resistance is less hindered.

The polyester resin (A1) in the present invention is a polyester resin obtained by polycondensation of an alcohol component (x) and a carboxylic acid component (y), and the composition of the resin is not particularly limited as long as it has an acid value of 1 mgKOH/g or more and reacts with an epoxy compound (E).
The polyester resin (A1) may be a single type alone or a combination of two or more types.

The polyester resin (A1) is a resin obtained by polycondensation of an alcohol component (x) and a carboxylic acid component (y).

The alcohol component (x) of the polyester resin (A1) may be a diol (x1) or a trihydric or higher polyol (x2). These may be used alone or in combination of two or more.

Diols (x1) include alkylene glycols having 2 to 36 carbon atoms (ethylene glycol, 1,2-propanediol, 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, 1,12-dodecanediol, etc.), alkylene ether glycols having 4 to 36 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diols having 6 to 36 carbon atoms (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), (poly)alkylene oxide adducts of the above alicyclic diols (preferably 1 to 30 average molar additions), aromatic diols [monocyclic dihydric phenols (e.g. hydroquinone, etc.) and bisphenols, etc.] and alkylene oxide adducts of the above aromatic diols (preferably 2 to 30 average molar additions).

The alkylene oxide adducts of the above bisphenols are obtained by adding alkylene oxide (hereinafter, "alkylene oxide" may be abbreviated as AO) to bisphenols.

The bisphenols include those represented by the following general formula (2).
HO-Ar-P-Ar-OH (2)
[In the formula, P represents an alkylene group having 1 to 3 carbon atoms, -SO ₂ -, -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.]

Specific examples of bisphenols include 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.

Examples of alkylene oxides added to bisphenols include alkylene oxides having 2 to 30 carbon atoms, such as ethylene oxide (hereinafter, "ethylene oxide" may be abbreviated as EO), 1,2- or 1,3-propylene oxide (hereinafter, "1,2-propylene oxide" may be abbreviated as PO), 1,2-, 2,3-, 1,3- or iso-butylene oxide, tetrahydrofuran, and combinations of two or more of these.

Examples of trivalent or higher polyols (x2) include aliphatic polyhydric alcohols having 3 to 36 carbon atoms and a valence of trivalent or higher, sugars and derivatives thereof, AO adducts of aliphatic polyhydric alcohols (average number of moles added is preferably 1 to 30), AO adducts of trisphenols (trisphenol PA, etc.) (average number of moles added is preferably 2 to 30), and AO adducts of novolak resins (including phenol novolak and cresol novolak, etc., with an average degree of polymerization of preferably 3 to 60) (average number of moles added is preferably 2 to 30).

Examples of the aliphatic polyhydric alcohol having 3 to 36 carbon atoms and a valence of three or more include alkane polyols and their intramolecular or intermolecular dehydration products, such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, polyglycerin, and dipentaerythritol.
Furthermore, examples of sugars and their derivatives include sucrose and methyl glucoside.

Of these alcohol components (x), from the viewpoint of dispersibility, diols (x1) are preferred, alkylene oxide adducts of aromatic diols are more preferred, alkylene oxide adducts of bisphenols (average number of moles added is preferably 2 to 5) are even more preferred, alkylene oxide adducts of bisphenol A (average number of moles added is preferably 2 to 5) are particularly preferred, and EO and/or PO adducts of bisphenol A (average number of moles added is preferably 2 to 3) are most preferred.

The diol (x1) in the alcohol component (x) of the polyester resin (A1) is preferably 80 to 100 mol %. When the diol (x1) is used in combination with a trihydric or higher polyol (x2), the molar ratio of the diol (x1) to the trihydric or higher polyol (x2) [(x1)/(x2)] is preferably 99/1 to 80/20, more preferably 98/2 to 85/15, from the viewpoint of charge retention rate (charge retention rate under high temperature and high humidity conditions).

In addition to the alcohol component (x), the polyester resin (A1) may contain a mono-ol component as an alcohol component, if necessary. Examples of mono-ols 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).

The carboxylic acid component (y) of the polyester resin (A1) may be a dicarboxylic acid (y1) or a trivalent or higher polycarboxylic acid (y2). These may be used alone or in combination of two or more.

Examples of dicarboxylic acids (y1) include aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.), aliphatic dicarboxylic acids having 2 to 50 carbon atoms (oxalic acid, malonic acid, succinic acid, adipic acid, leuparic acid, sebacic acid, etc.), alicyclic dicarboxylic acids having 6 to 40 carbon atoms (dimer acid (dimerized linoleic acid), etc.), alkene dicarboxylic acids having 4 to 36 carbon atoms (alkenyl succinic acids such as dodecenyl succinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, etc.), and ester-forming derivatives thereof. Here, the ester-forming derivatives refer to carboxylic acid anhydrides, alkyl (methyl, ethyl, butyl, stearyl, etc. having 1 to 24 carbon atoms, preferably those having 1 to 4 carbon atoms) esters, and partial alkyl esters.

Examples of trivalent or higher polycarboxylic acids (y2) include trivalent or higher aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), aliphatic (including alicyclic) tricarboxylic acids having 6 to 36 carbon atoms (such as hexanetricarboxylic acid and decanetricarboxylic acid), and ester-forming derivatives thereof.

Among these carboxylic acid components (y), from the viewpoint of charge retention rate (charge retention rate under high temperature and high humidity conditions), aromatic dicarboxylic acids having 8 to 36 carbon atoms, aliphatic dicarboxylic acids having 2 to 50 carbon atoms, aromatic polycarboxylic acids having 9 to 20 carbon atoms, and alkene dicarboxylic acids having 4 to 36 carbon atoms are preferred, and terephthalic acid, isophthalic acid, adipic acid, succinic acid, maleic acid, fumaric acid, trimellitic acid, and pyromellitic acid are more preferred, and terephthalic acid, isophthalic acid, adipic acid, and trimellitic acid are even more preferred. In addition, anhydrides and lower alkyl esters of these acids may be used.

The dicarboxylic acid (y1) in the carboxylic acid component (y) of the polyester resin (A1) is preferably 60 to 100 mol %. When the dicarboxylic acid (y1) is used in combination with a trivalent or higher polycarboxylic acid (y2), the molar ratio [(y1)/(y2)] of the dicarboxylic acid (y1) to the trivalent or higher polycarboxylic acid (y2) is preferably 99/1 to 65/35, more preferably 98/2 to 69/31, from the viewpoint of charge retention rate (charge retention rate under high temperature and high humidity conditions).

In addition to the carboxylic acid component (y), the polyester resin (A1) may contain a monocarboxylic acid component as the carboxylic acid component, if necessary. Examples of the monocarboxylic acid include aromatic monocarboxylic acids having 7 to 37 carbon atoms (benzoic acid, toluic acid, 4-ethylbenzoic acid, 4-propylbenzoic acid, etc.), and aliphatic (including alicyclic) monocarboxylic acids having 2 to 50 carbon atoms (acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, behenic acid, etc.).

The polyester resin (A1) of the present invention can be produced in the same manner as known polyester resin production methods. For example, the polycondensation reaction can be carried out by polycondensing the alcohol component (x) and the carboxylic acid component (y) in an inert gas (nitrogen gas, etc.) atmosphere at a reaction temperature of preferably 150 to 280°C, more preferably 160 to 250°C, and even more preferably 170 to 235°C. The reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours, from the viewpoint of ensuring that the polycondensation reaction is carried out. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.

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

A stabilizer may be added to facilitate stable polymerization of the polyester. Examples of stabilizers include hydroquinone, methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,6-di-tert-butyl-4-methoxyphenol, and hindered phenol compounds.

The weight ratio of the alcohol component (x) and the carboxylic acid component (y) used in the polycondensation reaction is preferably 1/2 to 2/1, more preferably 1/1.5 to 1.5/1, and even more preferably 1/1.3 to 1.3/1, in terms of the equivalent ratio of hydroxyl groups to carboxyl groups ([OH]/[COOH]). The above hydroxyl groups are hydroxyl groups derived from the alcohol component (x), and the carboxyl groups are the sum of the carboxyl groups derived from the carboxylic acid component (y).

There is no particular restriction on whether the polyester resin (A1) is crystalline or not, but from the viewpoint of heat-resistant storage stability, it is preferable that the polyester resin is an amorphous polyester resin. The amorphous polyester resin can be obtained by increasing the content of a branched monomer, for example, an alkylene oxide adduct of a bisphenol, in the alcohol component (x) and the carboxylic acid component (y) used.

The polyester resin (A1) may be any of a linear polyester resin, a crosslinked polyester resin, or a mixture of a linear polyester resin and a crosslinked polyester resin, but from the viewpoint of charge retention, it is preferably a crosslinked polyester resin or a mixture of a linear polyester resin and a crosslinked polyester resin, and more preferably a crosslinked polyester resin. The crosslinked polyester resin can be produced by using a trivalent or higher polyol (x2) and/or a trivalent or higher polycarboxylic acid (y2) as the alcohol component (x) and the carboxylic acid component (y) of the polyester resin (A1).

The glass transition temperature (Tg _A1 ) of the polyester resin (A1) is preferably −35 to 55° C., more preferably −15 to 55° C., even more preferably 15 to 55° C., and particularly preferably 35 to 55° C., from the viewpoints of low-temperature fixability, heat-resistant storage stability, water resistance, and durability.
The Tg is measured by a differential scanning calorimeter (DSC) according to the method (DSC method) specified in ASTM D3418-82.

The peak top molecular weight (hereinafter sometimes abbreviated as Mp) of the polyester resin (A1) is preferably from 2,000 to 200,000, more preferably from 2,500 to 100,000, still more preferably from 3,000 to 60,000, and particularly preferably from 5,000 to 30,000, from the viewpoints of low-temperature fixability and heat-resistant storage stability.
The Mp of the polyester resin (A1) is measured by gel permeation chromatography (GPC) under the following conditions.

First, a calibration curve is prepared by gel permeation chromatography (GPC) using standard polystyrene samples.
Next, the sample is separated by GPC, and the count number of the separated sample at each retention time is measured.
Next, a molecular weight distribution chart of the sample is prepared from the logarithmic values of the calibration curve and the obtained counts. The maximum value of the peak in the molecular weight distribution chart is the peak top molecular weight Mp.
When there are multiple peaks in the molecular weight distribution chart, the maximum value among the peaks is taken as the peak top molecular weight (Mp). The measurement conditions for the GPC measurement are as follows:

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 polyester resin (A1) can be measured using GPC under the following conditions.
Apparatus: HLC-8120 [manufactured by Tosoh Corporation]
Column: 2 TSK GEL GMH6 columns (manufactured by Tosoh Corporation)
Measurement temperature: 40°C
Sample solution: 0.25 wt% THF solution Solution injection amount: 100 μL
Detector: Refractive index detector Reference material: 12 standard polystyrenes (TSKstandard POLYSTYRENE) (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) [manufactured by Tosoh Corporation]
For measuring the molecular weight, a sample is dissolved in tetrahydrofuran (THF) to a concentration of 0.25% by weight, and the insoluble matter is filtered off using a glass filter to obtain a sample solution.
It should be noted that for the resin (B) and toner binder described below, Mp, Mn and Mw can be determined in the same manner as above.

The polyester resin (A1) has an acid value of 1 mgKOH/g or more. An acid value of 1 mgKOH/g or more means that the polyester resin (A1) has a carboxyl group or the like necessary for reacting with the epoxy compound (E). From the viewpoints of water resistance, hot offset resistance, heat resistance storage stability, and charge retention, the acid value of the polyester resin (A1) is preferably 7.0 to 50.0 mgKOH/g, more preferably 10.0 to 49.0 mgKOH/g, and even more preferably 20.0 to 49.0 mgKOH/g.

The acid value of the polyester resin (A1) can be measured under the following conditions by the method specified in JIS K0070.
1) Accurately weigh the sample and let its weight be S (g).
2) Place the sample in a 200 mL Erlenmeyer flask, add 50 mL of a mixed solvent of acetone, methanol, and toluene (acetone:methanol:toluene = 12.5:12.5:75), add a few drops of phenolphthalein indicator, and titrate using a 0.1 N KOH-methanol solution. The amount of KOH solution used at this time is designated as A (ml). At the same time, a blank test is performed, and the amount of KOH solution used at this time is designated as B (ml).
3) Calculate the acid value using the following formula.
Acid value = (A - B) x f x 5.61 ÷ S (f: titer of KOH solution)
The acid value of the resin (B) and the toner binder described below can also be determined in the same manner as above.

The epoxy compound (E) is not particularly limited as long as it has an epoxy group in the molecule, but from the viewpoint of charge retention rate (charge retention rate under high temperature and high humidity conditions), a polyfunctional epoxy compound having two or more epoxy groups in the molecule is preferred. Examples of polyfunctional epoxy compounds include aromatic polyepoxy compounds, heterocyclic polyepoxy compounds, alicyclic polyepoxy compounds, and aliphatic polyepoxy compounds. The epoxy compound (E) may be used alone or in combination of two or more types.

Aromatic polyepoxy compounds include glycidyl ethers of polyhydric phenols, glycidyl esters of aromatic polycarboxylic acids, glycidyl aromatic polyamines, and other aromatic polyepoxy compounds.

Glycidyl ethers of polyhydric phenols include bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, bisphenol B diglycidyl ether, bisphenol AD diglycidyl ether, bisphenol S diglycidyl ether, halogenated bisphenol A diglycidyl ether, tetrachloro bisphenol A diglycidyl ether, catechin diglycidyl ether, resorcinol diglycidyl ether, hydroquinone diglycidyl ether, pyrogallol triglycidyl ether, 1,5-dihydroxynaphthalene diglycidyl ether, dihydroxybiphenyl diglycidyl ether, octachloro-4,4'-dihydroxybiphenyl diglycidyl ether, tetramethylbiphenyl diglycidyl ether, dihydroxynaphthyl cresol triglycidyl ether, tris(hydroxyphenyl)methane triglycidyl ether, dinaphthyltriol triglycidyl ether, and tetrakis(4-hydroxyphenyl)ethane tetraglycidyl ether. ter, p-glycidylphenyldimethyltriyl bisphenol A glycidyl ether, trismethyl-t-butyl-butylhydroxymethane triglycidyl ether, 9,9'-bis(4-hydroxyphenyl)fluoroenyl glycidyl ether, 4,4'-oxybis(1,4-phenylethyl)tetracresol glycidyl ether, 4,4'-oxybis(1,4-phenylethyl)phenyl glycidyl ether, bis(dihydroxynaphthalene)tetraglycidyl ether, novolac type epoxy resins (phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, limonene phenol novolac type epoxy resins, etc.), bisphenol A type epoxy resins, polyglycidyl ethers of polyphenols obtained by condensation reaction of polyhydric phenols with glyoxal, glutaraldehyde or formaldehyde, and polyglycidyl ethers of polyphenols obtained by condensation reaction of resorcinol with acetone, etc.

Examples of glycidyl esters of aromatic polycarboxylic acids include diglycidyl ester of phthalic acid, diglycidyl ester of isophthalic acid, and diglycidyl ester of terephthalic acid.

Glycidyl aromatic polyamines include N,N-diglycidyl aniline, N,N,N',N'-tetraglycidyl xylylenediamine, and N,N,N',N'-tetraglycidyl diphenylmethanediamine.

Other aromatic polyepoxy compounds include triglycidyl ethers of p-aminophenol, diglycidyl urethane compounds obtained by the addition reaction of tolylene diisocyanate or diphenylmethane diisocyanate with glycidol, glycidyl group-containing polyurethane (pre)polymers obtained by reacting the above two reactants with polyols, and diglycidyl ethers of AO adducts of bisphenol A.

An example of a heterocyclic polyepoxy compound is trisglycidylmelamine.

Examples of alicyclic polyepoxy compounds include vinylcyclohexene dioxide, limonene dioxide, dicyclopentadiene dioxide, bis(2,3-epoxycyclopentyl)ether, ethylene glycol bisepoxydicyclopentyl ether, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-6'-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)butylamine, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, and dimer acid diglycidyl ester. Examples of alicyclic polyepoxy compounds include hydrogenated products of the aromatic polyepoxy compounds.

Examples of aliphatic polyepoxy compounds include polyglycidyl ethers of aliphatic polyhydric alcohols, polyglycidyl esters of aliphatic polycarboxylic acids, and glycidyl aliphatic amines.

Examples of polyglycidyl ethers of aliphatic polyhydric alcohols include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, and polyglycerol polyglycidyl ether.

Examples of polyglycidyl esters of aliphatic polycarboxylic acids include diglycidyl oxalate, diglycidyl malate, diglycidyl succinate, diglycidyl glutarate, diglycidyl adipate, and diglycidyl pimelate.

Examples of the glycidyl aliphatic amines include N,N,N',N'-tetraglycidylhexamethylenediamine.
The aliphatic polyepoxy compounds also include (co)polymers of diglycidyl ether and glycidyl (meth)acrylate.

Among these polyfunctional epoxy compounds, from the viewpoint of durability and charge retention rate (charge retention rate under high temperature and high humidity), aromatic polyepoxy compounds, alicyclic polyepoxy compounds, and aliphatic polyepoxy compounds are preferred, aromatic polyepoxy compounds are more preferred, and novolac epoxy resins and bisphenol A epoxy resins are even more preferred. The above-mentioned epoxy compounds (E) may be used alone or in combination.

The epoxy compound (E) in the present invention is preferably a polyfunctional epoxy compound having an epoxy equivalent of 170 to 900 (g/eq, the same applies below), more preferably 180 to 900, and even more preferably 190 to 900. If the epoxy equivalent of the epoxy compound (E) is 170 or more, the low-temperature fixing property is good, and if it is 900 or less, the charge retention rate (charge retention rate under high temperature and high humidity conditions) is good.

The weight ratio of the polyester resin (A1) to the epoxy compound (E) [(A1):(E)] is 65:35 to 98:2, preferably 67:33 to 98:2% by weight, and more preferably 68:32 to 98:2% by weight, from the viewpoints of dispersibility and charge retention rate (charge retention rate under high temperature and high humidity conditions).

In the present invention, the reaction product of polyester resin (A1) and epoxy compound (E) can be obtained by reacting polyester resin (A1) with epoxy compound (E) in the presence of resin (B) and catalyst (F). From the viewpoint of hot offset resistance, the reaction product is preferably a crosslinked resin, and can be obtained by using the above-mentioned polyfunctional epoxy compound having an epoxy equivalent of 170 to 900 as epoxy compound (E).
The reaction is preferably carried out in an inert gas (nitrogen gas, etc.) atmosphere. From the viewpoint of ensuring the reaction, the reaction temperature is preferably 100 to 200° C., more preferably 130 to 190° C., and even more preferably 150 to 180° C. The reaction time is preferably 1 to 180 minutes, more preferably 2 to 18 minutes, from the viewpoints of low-temperature fixability, hot offset resistance, and odor.

上記一般式（１）中、Ｒ^１～Ｒ^３はそれぞれ独立に水素原子、アルキル基又はアリール基であり、アルキル基としては、例えば、炭素数１～４のアルキル基（メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基及びｔｅｒｔ－ブチル等）が挙げられる。また、アリール基としては、炭素数６～１０のアリール基（フェニル基、ベンジル基、トリル基及びキシリル基等）が挙げられる。
一般式（１）中、Ｒ^１～Ｒ^３は、画像強度、耐久性、耐水性及び製造性の観点から、好ましくは水素、炭素数１～４のアルキル基及び炭素数６～１０のアリール基が好ましく、より好ましくは水素、メチル基、エチル基及びフェニル基である。
The production method of the present invention includes a step of reacting a polyester resin (A1) with an epoxy compound (E) in the presence of a catalyst (F). The catalyst (F) is a compound represented by general formula (1), and may be a single type or a combination of two or more types.

In the above general formula (1), R ¹ to R ³ are each independently a hydrogen atom, an alkyl group, or an aryl group, and examples of the alkyl group include alkyl groups having 1 to 4 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl), and examples of the aryl group include aryl groups having 6 to 10 carbon atoms (such as phenyl, benzyl, tolyl, and xylyl).
In general formula (1), from the viewpoints of image strength, durability, water resistance and manufacturability, R ¹ to R ³ are preferably hydrogen, an alkyl group having 1 to 4 carbon atoms and an aryl group having 6 to 10 carbon atoms, and more preferably hydrogen, a methyl group, an ethyl group and a phenyl group.

Specific examples of the catalyst (F) satisfying the above general formula (1) include imidazole, 2-methylimidazole, 4-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-phenylimidazole, 2,4-methylimidazole, 2-ethyl-4-methylimidazole, and 2,4,5-triphenylimidazole.

In the reaction of the polyester resin (A1) with the epoxy compound (E), known catalysts other than those mentioned above (such as tertiary amines, imidazoles, and quaternary ammonium salts) can also be added.

The manufacturing method of the present invention includes a step of reacting polyester resin (A1) with epoxy compound (E) in the presence of resin (B).

The resin (B) is not particularly limited in composition as long as it has an acid value of less than 1 mgKOH/g, and examples thereof include polyester resin (B1), vinyl resin (B2), polyurethane resin (B3), epoxy resin (B4), polyamide resin (B5), etc., and may be used alone or in combination of two or more. Of the above resins, polyester resin (B1) and vinyl resin (B2) are preferred from the viewpoint of low-temperature fixability. The acid value of resin (B) is preferably 0.3 mgKOH/g or less, and more preferably 0 mgKOH/g.

The polyester resin (B1) is a polyester resin obtained by polycondensation of an alcohol component (x) and a carboxylic acid component (y), and is not particularly limited as long as the acid value is less than 1 mgKOH/g.

The alcohol component (x) of polyester resin (B1) may be the same as that of polyester resin (A1).

Of the above alcohol components (x), from the viewpoint of low-temperature fixability, diols (x1) are preferred, alkylene oxide adducts of aromatic diols are more preferred, alkylene oxide adducts of bisphenols (average number of moles added is preferably 2 to 5) are even more preferred, alkylene oxide adducts of bisphenol A (average number of moles added is preferably 2 to 5) are particularly preferred, and EO and/or PO adducts of bisphenol A (average number of moles added is preferably 2 to 3) are most preferred.

The carboxylic acid component (y) of polyester resin (B1) may be the same as that of polyester resin (A1).

Of the above carboxylic acid components (y), from the viewpoint of charge retention rate (charge retention rate under high temperature and high humidity conditions), aromatic dicarboxylic acids having 8 to 36 carbon atoms, aliphatic dicarboxylic acids having 2 to 50 carbon atoms, and aromatic polycarboxylic acids having 9 to 20 carbon atoms are preferred, aromatic dicarboxylic acids having 8 to 36 carbon atoms, and aliphatic dicarboxylic acids having 2 to 50 carbon atoms are more preferred, and terephthalic acid, isophthalic acid, adipic acid, succinic acid, maleic acid, and fumaric acid are even more preferred. In addition, anhydrides and lower alkyl esters of these acids may also be used.

The weight ratio of the alcohol component (x) and the carboxylic acid component (y) used in the polycondensation reaction is preferably 1/1 to 2/1, more preferably 1/1 to 1.5/1, and even more preferably 1.05/1 to 1.3/1, in terms of the equivalent ratio of hydroxyl groups to carboxyl groups ([OH]/[COOH]). The above hydroxyl groups are hydroxyl groups derived from the alcohol component (x), and the carboxyl groups are the sum of the carboxyl groups derived from the carboxylic acid component (y).

The polyester resin (B1) of the present invention can be produced in the same manner as the production method of the polyester resin (A1) described above.

There is no particular restriction on whether the polyester resin (B1) is crystalline or not, but from the viewpoint of heat-resistant storage stability, it is preferable that the polyester resin is an amorphous polyester resin. The amorphous polyester resin can be obtained by increasing the content of a branched monomer, for example, an alkylene oxide adduct of a bisphenol, in the alcohol component (x) and the carboxylic acid component (y) used.

The polyester resin (B1) may be a linear polyester resin, a crosslinked polyester resin, or a mixture of a linear polyester resin and a crosslinked polyester resin, but from the viewpoint of low-temperature fixability, a linear polyester resin is preferred.

The glass transition temperature (Tg _B1 ) of the polyester resin (B1) is preferably from 50 to 80°C, more preferably from 50 to 70°C, and even more preferably from 55 to 65°C, from the viewpoints of low-temperature fixability, water resistance and durability.
The Tg is measured by using a DSC according to the method (DSC method) specified in ASTM D3418-82.

The peak top molecular weight (hereinafter sometimes abbreviated as Mp) of the polyester resin (B1) is preferably from 2,000 to 200,000, more preferably from 2,500 to 100,000, even more preferably from 3,000 to 30,000, and particularly preferably from 5,000 to 10,000, from the viewpoints of low-temperature fixability and heat-resistant storage stability.
The Mp of (B1) is measured by GPC under the same conditions as above.

The vinyl resin (B2) is a polymer having a monomer having a double bond as a constituent monomer, and is not particularly limited as long as the acid value is less than 1 mgKOH/g. Examples of vinyl resins include crystalline vinyl resins and amorphous vinyl resins, and crystalline vinyl resins are preferred from the viewpoint of low-temperature fixability and water resistance. The "crystalline" of a crystalline vinyl resin means that there is a maximum in the differential scanning calorimetry curve (DSC curve) obtained by differential scanning calorimetry during the temperature rise process of the DSC curve, and there is an endothermic peak. On the other hand, "amorphous" means that there is no endothermic peak in the DSC curve.

From the viewpoints of crystallinity and low-temperature fixability, the crystalline vinyl resin is preferably a polymer having, as a constituent monomer, a monomer (a) which is a (meth)acrylate having a chain hydrocarbon group and having 21 to 40 carbon atoms and/or a vinyl ester having a chain hydrocarbon group and having 21 to 40 carbon atoms. If the monomer (a) has 21 or more carbon atoms, the heat-resistant storage stability may be good, and if the monomer (a) has 40 or less carbon atoms, the low-temperature fixability may be good.
In the present invention, "(meth)acrylic" means methacrylic acid or acrylic acid, and "(meth)acrylate" means methacrylate or acrylate.

Examples of the monomer (a) include (meth)acrylates having a chain hydrocarbon group and having 21 to 40 carbon atoms and/or vinyl esters having a chain hydrocarbon group and having 21 to 40 carbon atoms. Examples of the (meth)acrylates having a chain hydrocarbon group and having 21 to 40 carbon atoms include (meth)acrylates having a linear alkyl group (having 18 to 36 carbon atoms) [octadecyl (meth)acrylate (stearyl (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, dotriacontyl (meth)acrylate, and the like] and (meth)acrylates having a branched alkyl group (having 18 to 36 carbon atoms) [2-decyltetradecyl (meth)acrylate, and the like].
Examples of vinyl esters having a chain hydrocarbon group and having 21 to 40 carbon atoms include vinyl esters having a linear alkyl group (having 18 to 36 carbon atoms) [e.g., vinyl stearate, vinyl behenate, vinyl triacontanoate, vinyl hexatriacontanoate, etc.] and vinyl esters having a branched alkyl group (having 18 to 36 carbon atoms).
Among these, from the viewpoint of crystallinity, preferred are (meth)acrylates having a linear alkyl group (having 18 to 36 carbon atoms) and vinyl esters having a linear alkyl group (having 18 to 36 carbon atoms), more preferred are (meth)acrylates having a linear alkyl group (having 18 to 30 carbon atoms), even more preferred are octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, seryl (meth)acrylate and triacontyl (meth)acrylate, particularly preferred are octadecyl acrylate (stearyl acrylate), eicosyl acrylate, behenyl acrylate and lignoceryl acrylate, and most preferred is behenyl acrylate.
The monomer (a) may be used alone or in combination of two or more kinds.

The crystalline vinyl resin may contain a monomer (b) other than the monomer (a) as a constituent monomer. As the monomer (b), a styrene-based monomer (b1), a (meth)acrylic-based monomer (b2) other than the monomer (a), a vinyl ester monomer (b3) other than the monomer (a), an aliphatic hydrocarbon-based vinyl monomer (b4), and a monomer (b5) 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 are preferable as the constituent monomer.
The monomer (b) may be used alone or in combination of two or more kinds.

Examples of styrene-based monomers (b1) include styrene and alkylstyrenes having an alkyl group with 1 to 3 carbon atoms (e.g., α-methylstyrene and p-methylstyrene, etc.).

Examples of (meth)acrylic monomers (b2) include alkyl (meth)acrylates having an alkyl group with 1 to 17 carbon atoms [methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, etc.], hydroxyalkyl (meth)acrylates having an alkyl group with 1 to 17 carbon atoms [2-hydroxypropyl acrylate, 2-hydroxyethyl (meth)acrylate, ethyl-2-(hydroxymethyl)acrylate, etc.], and hydroxyalkyl (meth)acrylates having an alkyl group with 1 to 17 carbon atoms [2-hydroxypropyl acrylate, 2-hydroxyethyl (meth)acrylate, ethyl-2-(hydroxymethyl)acrylate, etc.]. 7, aminoalkyl group-containing (meth)acrylates [dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc.], esters of unsaturated carboxylic acids having 8 to 20 carbon atoms and polyhydric alcohols [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, polyethylene glycol di(meth)acrylate, etc.], etc.

Examples of vinyl ester monomers (b3) include aliphatic vinyl esters having 4 to 15 carbon atoms (e.g., vinyl acetate, vinyl propionate, isopropenyl acetate, etc.) and aromatic vinyl esters having 9 to 15 carbon atoms (e.g., methyl-4-vinylbenzoate, etc.).

Aliphatic hydrocarbon vinyl monomers (b4) include ethylene, propylene, butene, butadiene, isoprene, and 1,5-hexadiene.

Examples of the monomer (b5) 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 include a monomer (b51) having a nitrile group, a monomer (b52) having a urethane group, a monomer (b53) having a urea group, a monomer (b54) having an amide group, a monomer (b55) having an imide group, a monomer (b56) having an allophanate group, and a monomer (b57) having a biuret group.

Examples of monomers (b51) having a nitrile group include acrylonitrile and methacrylonitrile.

Examples of the monomer (b52) having a urethane group include a monomer obtained by reacting an alcohol having 2 to 22 carbon atoms (2-hydroxyethyl methacrylate, vinyl alcohol, etc.) having an ethylenically unsaturated bond with an isocyanate having 1 to 30 carbon atoms by a known method, and a monomer obtained by reacting an alcohol having 1 to 26 carbon atoms with an isocyanate having 2 to 30 carbon atoms by a known method. Note that in this specification, the number of carbon atoms in a compound and structure having an isocyanate group does not include the number of carbon atoms contained in the isocyanate (NCO).
Examples of isocyanates having 1 to 30 carbon atoms include monoisocyanate compounds (benzenesulfonyl isocyanate, tosyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, butyl isocyanate, hexyl isocyanate, t-butyl isocyanate, cyclohexyl isocyanate, octyl isocyanate, 2-ethylhexyl isocyanate, dodecyl isocyanate, adamantyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, and 2,6-dipropylphenyl isocyanate, etc.), aliphatic diisocyanate compounds (trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylethylene diisocyanate, etc.), and cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated tetramethylxylylene diisocyanate, etc.) and aromatic diisocyanates. diisocyanate compounds (phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, and the like).
Examples of alcohols having 1 to 26 carbon atoms include methanol, ethanol, propanol, isopropyl alcohol, butanol, t-butyl alcohol, pentanol, heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecyl alcohol, lauryl alcohol, dodecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetanol, heptadecanol, stearyl alcohol, isostearyl alcohol, elaidyl alcohol, oleyl alcohol, linoleyl alcohol, linolenyl alcohol, nonadecyl alcohol, heneicosanol, behenyl alcohol, and erucyl alcohol.
Examples of the isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond include 2-isocyanatoethyl (meth)acrylate, 2-[0-(1'-methylpropylideneamino)carboxyamino]ethyl (meth)acrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, and 1,1-(bis(meth)acryloyloxymethyl)ethyl isocyanate.

Examples of monomers (b53) having a urea group include monomers obtained by reacting an amine having 3 to 22 carbon atoms [monovalent amines include, for example, primary amines (normal butylamine, t-butylamine, propylamine, isopropylamine, etc.), secondary amines (diethylamine, dinormal propylamine, dinormal butylamine, etc.), aniline, cyclohexylamine, etc.] with an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond by a known method.

Examples of the monomer (b54) having an amide group include monomers obtained by reacting an amine having 1 to 30 carbon atoms with a carboxylic acid having 3 to 30 carbon atoms (such as acrylic acid and methacrylic acid) having an ethylenically unsaturated bond by a known method.

Examples of monomers (b55) having an imide group include monomers obtained by reacting ammonia with an ethylenically unsaturated bond-containing carboxylic acid anhydride having 4 to 10 carbon atoms (maleic anhydride, diacrylic anhydride, etc.) by a known method, and monomers obtained by reacting a primary amine having 1 to 30 carbon atoms with an ethylenically unsaturated bond-containing carboxylic acid anhydride having 4 to 10 carbon atoms by a known method.

Examples of the monomer (b56) having an allophanate group include a monomer obtained by reacting a monomer (b52) having a urethane group with an isocyanate having 1 to 30 carbon atoms by a known method.

Examples of the monomer (b57) having a buret group include a monomer obtained by reacting a monomer (b53) having a urea group with an isocyanate having 1 to 30 carbon atoms by a known method.

Among these monomers (b), preferred from the viewpoint of charge retention rate and heat-resistant storage stability are styrene-based monomers (b1), (meth)acrylic monomers other than monomer (a) (b2), and monomers (b5) 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, more preferably styrene, an alkyl (meth)acrylate having an alkyl group of 1 to 17 carbon atoms, and a monomer (b51) having a nitrile group, and even more preferably styrene, methyl (meth)acrylate, butyl (meth)acrylate, acrylonitrile, and methacrylonitrile.

The weight ratio of monomer (a) among the monomers constituting the crystalline vinyl resin is preferably 30% by weight or more, more preferably 40% by weight or more, and even more preferably 60% by weight, based on the total weight of the monomers constituting the crystalline vinyl resin. When the weight ratio of monomer (a) is 30% by weight or more, the crystallinity and water resistance are good. On the other hand, the upper limit is preferably 99% by weight or less, more preferably 95% by weight or less, and even more preferably 80% by weight or less, from the viewpoint of achieving both low-temperature fixability, hot offset resistance, and heat-resistant storage stability.

From the viewpoint of heat-resistant storage stability, it is preferable that the monomers constituting the crystalline vinyl resin contain monomer (b). The weight ratio of monomer (b) in the monomers constituting the crystalline vinyl resin is preferably 1 to 70% by weight, more preferably 1 to 60% by weight, even more preferably 5 to 60% by weight, and particularly preferably 5 to 40% by weight, based on the total weight of the monomers constituting (B).

The vinyl resin (B2) can be produced by polymerizing a monomer composition by a known method (such as the method described in JP-A-5-117330). For example, it can be synthesized by a solution polymerization method in which the above-mentioned monomers are reacted with a radical reaction initiator (such as azobisisobutyronitrile) in a solvent (such as toluene).
The radical reaction initiator may be a known radical reaction initiator (c). The radical reaction initiator (c) is not particularly limited, and examples thereof include inorganic peroxides (c1), organic peroxides (c2), and azo compounds (c3). These radical reaction initiators may also be used in combination.

Inorganic peroxides (c1) are not particularly limited, but examples include hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

The organic peroxide (c2) is not particularly limited, but examples thereof 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-butylperoxyhexyne-3, acetyl peroxide, isobutyryl peroxide, octanyl peroxide, decanolyl peroxide, Examples include lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t-butyl peroxy isobutyrate, t-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxy laurate, t-butyl peroxy benzoate, t-butyl peroxy isopropyl monocarbonate, and t-butyl peroxy acetate.

The azo compound (c3) is not particularly limited, but examples thereof include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

From the viewpoints of heat-resistant storage stability and low-temperature fixability, the endothermic peak top temperature (Tm _B2 ) of the vinyl resin (B2) is preferably 40 to 100° C., more preferably 45 to 90° C. When the endothermic peak top temperature is 40° C. or higher, the heat-resistant storage stability is good, and when it is 100° C. or lower, the low-temperature fixability is good.
Here, the endothermic peak top temperature (Tm _B2 ) of the vinyl resin (B2) refers to the peak top temperature of the endothermic peak of the vinyl resin (B2) in the second heating process in which the crystalline vinyl resin (B) is heated for the first time using DSC from 20° C. to 150° C. at a rate of 10° C./min, then cooled from 150° C. to 0° C. at a rate of 10° C./min, and subsequently heated from 0° C. to 150° C. at a rate of 10° C./min.

The endothermic peak top temperature (Tm _B2 ) is a value measured using a DSC under the following conditions: As a differential scanning calorimeter, for example, DSC Q20 manufactured by TA Instruments Co., Ltd. can be used.
<Measurement conditions>
(1) Heat from 20° C. to 150° C. at 10° C./min. (2) Cool to 0° C. at 10° C./min. (3) Heat to 150° C. at 10° C./min. (4) Analyze each endothermic peak of the differential scanning calorimetry curve measured during the process of (3).

The number average molecular weight of the vinyl resin (B2) is preferably 1,000 to 300,000 from the viewpoints of heat resistance storage stability and low-temperature fixability.

The weight average molecular weight of the vinyl resin (B2) is preferably from 1,000 to 300,000, and more preferably from 17,000 to 60,000, from the viewpoints of heat-resistant storage stability and low-temperature fixability.
The Mn and Mw of the vinyl resin (B2) can be measured by the method described above.

The method for producing the toner binder of the present invention is not particularly limited as long as it includes a step of reacting the polyester resin (A1) with the epoxy compound (E) in the presence of the resin (B) and the catalyst (F), and examples of known mixing methods include powder mixing, melt mixing, and solvent mixing. The polyester resin (A1), the epoxy compound (E), the resin (B), and the catalyst (F) may be mixed together with other necessary toner raw materials at the same time when the toner is produced. Examples of the solvent used for the solvent mixing include ethyl acetate, tetrahydrofuran, methyl ethyl ketone, and acetone.

Examples of a mixer for powder mixing include a Henschel mixer, a Nauta mixer, and a Banbury mixer, with a Henschel mixer being preferred.
Examples of mixing devices for melt mixing include batch mixing devices such as reaction tanks and continuous mixing devices. Continuous mixing devices are preferred for uniform mixing in a short time at an appropriate temperature. Examples of continuous mixing devices include static mixers, extruders, continuous kneaders, and three-roll machines.
Examples of the solvent mixing method include a method in which the polyester resin (A1) and the resin (B) are dissolved in a solvent (ethyl acetate, tetrahydrofuran, acetone, etc.), homogenized, then the solvent is removed and pulverized, and a method in which the polyester resin (A1) and the resin (B) are dissolved in a solvent (ethyl acetate, tetrahydrofuran, acetone, etc.), dispersed in water, then granulated and the solvent is removed.

Of the melt mixing and solvent mixing, the melt mixing is preferred since it allows uniform mixing and does not require solvent removal.
Among these, the method of melt-mixing the resin (B) and the polyester resin (A1) while reacting the polyester resin (A1) with the epoxy compound (E) is preferred.

Examples of the method of reacting polyester (A1) with epoxy compound (E) while melt-mixing resin (B) with polyester resin (A1) include a method of injecting a mixture of polyester resin (A1) and resin (B) into a twin-screw extruder at a constant speed, simultaneously injecting catalyst (F) and epoxy compound (E) at a constant speed, and reacting while kneading and conveying at a temperature of 100 to 200° C., and a method of charging polyester resin (A1) and resin (B) into a batch-type mixer such as a reaction vessel, melting and uniformly mixing, and then charging catalyst (F) and epoxy compound (E) and crosslinking at a temperature of 100 to 200° C. In this case, the polyester resin (A1) and resin (B) as reaction raw materials to be charged or injected into the twin-screw extruder or reaction vessel may be directly injected into the extruder or reaction vessel as they are without cooling the reacted resins from the molten state, or the resins may be cooled and crushed once produced and then fed to the twin-screw extruder or reaction vessel.

In the toner binder production method of the present invention (before the reaction of polyester resin (A1) with epoxy compound (E)), the weight ratio of polyester resin (A1) to resin (B) [(A1):(B)] is preferably 20:80 to 80:20, more preferably 40:60 to 70:30, from the viewpoints of water resistance, durability, and low-temperature fixability.

From the viewpoint of uniformity of crosslinking and productivity, the temperature at which the polyester resin (A1) and the epoxy compound (E) are reacted is preferably 100 to 200°C, more preferably 130 to 190°C, and even more preferably 150 to 180°C. If the crosslinking temperature is 200°C or lower, decomposition of the vinyl resin is unlikely to occur and heat resistance storage properties are good, while if the crosslinking temperature is 100°C or higher, the resin viscosity is low and uniformity is good.

The time for reacting the polyester resin (A1) with the epoxy compound (E) using a continuous mixer such as a twin-screw extruder is preferably 1 to 20 minutes, more preferably 2 to 18 minutes, from the viewpoints of uniformity of crosslinking and productivity.
The time for reacting the polyester resin (A1) with the epoxy compound (E) using a batch-type mixing device such as a reaction tank is, from the viewpoints of uniformity of crosslinking and productivity, preferably 30 to 600 minutes, more preferably 60 to 540 minutes, even more preferably 90 to 480 minutes, and particularly preferably 120 to 420 minutes.

From the viewpoints of low-temperature fixability, hot offset resistance, and durability, the reaction rate of the polyester resin (A1) and the epoxy compound (E) is preferably 90% or more, and more preferably 95% or more.

In the present invention, the steps other than the step of reacting the polyester resin (A1) with the epoxy compound (E) in the presence of the catalyst (F) are not particularly limited, and a general toner binder production step can be adopted.
For example, when the above-mentioned process is carried out by melt mixing, a process of taking out the toner binder can be provided, and when the above-mentioned crosslinking process is carried out by solvent mixing, a process of taking out the toner binder after removing the solvent and pulverizing it can be provided. When the above-mentioned process is carried out by solvent mixing, a process of dispersing in water, granulating and removing the solvent can be provided. Furthermore, a process of mixing additives with the obtained granular toner binder by a known method can also be provided.

From the viewpoints of low-temperature fixability and heat-resistant storage stability, the endothermic peak top temperature (Tm _C ) of the toner binder of the present invention is preferably 40 to 100° C., more preferably 45 to 90° C. When the endothermic peak top temperature is 40° C. or higher, the heat-resistant storage stability is good, and when it is 100° C. or lower, the low-temperature fixability is good.
Here, the endothermic peak top temperature (Tm _C ) of the toner binder refers to the endothermic peak top temperature of the toner binder in a second heating process in which the toner binder is heated using a differential scanning calorimeter (DSC) for the first time from 20° C. to 150° C. at a rate of 10° C./min, 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. The endothermic peak top temperature (Tm _C ) of the toner binder can be measured in the same manner as the endothermic peak top temperature (Tm _B2 ) of the vinyl resin (B2) described above.
The endothermic peak top temperature (Tm _C ) of the toner binder can be adjusted to the above-mentioned preferred range by adjusting the carbon number of the monomer (a) constituting the vinyl resin (B2), adjusting the weight ratio of the monomer (a) constituting the vinyl resin (B2), etc. In general, the endothermic peak top temperature (Tm _C ) tends to increase by increasing the carbon number of the monomer (a), increasing the weight ratio of the monomer (a), and increasing the weight average molecular weight of the vinyl resin (B2).

The glass transition temperature (Tg _C ) of the toner binder is preferably from -35 to 60°C, more preferably from -15 to 58°C, further preferably from 15 to 55°C, and particularly preferably from 35 to 55°C, from the viewpoints of water resistance and low-temperature fixability.
The Tg is measured by using a DSC according to the method specified in ASTM D3418-82 (DSC method). For the glass transition temperature (Tg _C ), for example, a DSC Q20 manufactured by TA Instruments Co., Ltd. can be used. The glass transition temperature (Tg _C ) can be measured under the following conditions.
<Measurement conditions>
(1) Heat from 30°C to 150°C at 20°C/min. (2) Hold at 150°C for 10 minutes. (3) Cool to -35°C at 20°C/min. (4) Hold at -35°C for 10 minutes. (5) Heat to 150°C at 20°C/min. (6) The differential scanning calorimetry curve measured during (5) is analyzed.

The acid value of the toner binder is preferably 4.0 to 50.0 mgKOH/g, more preferably 4.0 to 30.0 mgKOH/g, and even more preferably 4.0 to 20.0 mgKOH/g, from the viewpoints of heat-resistant storage stability, durability, water resistance, and charge retention rate.
The acid value of the toner binder can be determined in the same manner as in the polyester resin (A1).

When producing a toner using the toner binder obtained by the method of the present invention, in addition to the toner binder of the present invention, one or more known additives selected from colorants, release agents, charge control agents, and flow agents, etc., can be used as necessary.

As the colorant, all of the dyes and pigments used as toner colorants can be used. For example, carbon black, iron black, Sudan Black SM, Fast Yellow G, Benzidine Yellow, Pigment Yellow, India Fast Orange, Irgasin 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, Orazol Brown B, and Oil Pink OP can be mentioned, and the colorant may be a single one or a mixture of two or more kinds. In addition, if necessary, magnetic powder (powder of ferromagnetic metals such as iron, cobalt, and nickel, or compounds such as magnetite, hematite, and ferrite) can be contained to function as a colorant.
The content of the colorant is preferably 1 to 40 parts by weight, more preferably 3 to 10 parts by weight, based on 100 parts by weight of the toner binder. When a magnetic powder is used, the content is preferably 20 to 150 parts by weight, more preferably 40 to 120 parts by weight, based on 100 parts by weight of the toner binder.

The release agent preferably has a flow softening point (T1/2) of 50 to 170°C as measured by a flow tester, and examples of such agents include aliphatic hydrocarbon waxes such as polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, as well as their oxides, carnauba wax, montan wax, and their deacidified waxes, ester wax, fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts.

The flow softening point (T1/2) of the release agent is a value measured under the following conditions.
<Method for measuring flow softening point (T1/2)>
Test force: Using an extrusion-type capillary rheometer flow tester [e.g., CFT-500D, manufactured by Shimadzu Corporation], 1 g of a measurement sample is heated at a temperature increase rate of 6°C/min while applying a load of 1.96 MPa with a plunger and extruding the sample from a nozzle having a diameter of 1 mm and a length of 1 mm. A graph of "plunger depression amount (flow value)" versus "temperature" is drawn, and the temperature corresponding to 1/2 of the maximum value of the plunger depression amount is read from the graph, and this value (the temperature when half of the measurement sample has flowed out) is taken as the flow softening point (T1/2).

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 those obtained by further thermal degradation] (e.g., low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene-polyethylene copolymer), oxides of olefin (co)polymers with 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, dimethyl maleate, etc.) modified products], copolymers of olefins and unsaturated carboxylic acids [(meth)acrylic acid, itaconic acid, maleic anhydride, etc.] and/or unsaturated carboxylic acid alkyl esters [(meth)acrylic acid alkyl esters (alkyl having 1 to 18 carbon atoms) and maleic acid alkyl esters (alkyl having 1 to 18 carbon atoms), etc.], etc.

Examples of microcrystalline waxes include Hi-Mic-2095, Hi-Mic-1090, Hi-Mic-1080, Hi-Mic-1070, Hi-Mic-2065, Hi-Mic-1045, and Hi-Mic-2045 manufactured by Nippon Seiro Co., Ltd.

Examples of paraffin waxes include Paraffin WAX-155, Paraffin WAX-150, Paraffin WAX-145, Paraffin WAX-140, Paraffin WAX-135, HNP-3, HNP-5, HNP-9, HNP-10, HNP-11, HNP-12, and HNP-51 manufactured by Nippon Seiro Co., Ltd.

Examples of Fischer-Tropsch wax include Sasolwax C80 manufactured by Sasol.

Examples of carnauba wax include Refined Carnauba Wax Special No. 1 manufactured by Kato Yoko Co., Ltd.

Examples of ester waxes include fatty acid ester waxes (e.g., Nissan Electol WEP-2, WEP-3, WEP-4, WEP-5, and WEP-8 manufactured by NOF Corp.).

Examples of higher alcohols include aliphatic alcohols having 30 to 50 carbon atoms, such as triacontanol. Examples of fatty acids include fatty acids having 30 to 50 carbon atoms, such as triacontanol.

Examples of fatty acid amides include Diamid Y and Diamid 200 manufactured by Mitsubishi Chemical Corporation.

The charge control agent may be either a positively charged charge control agent or a negatively charged charge control agent, and examples of the charge control agent include nigrosine dyes, triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salts, polyamine resins, imidazole derivatives, polymers containing quaternary ammonium bases, metal-containing azo dyes, copper phthalocyanine dyes, metal salts of salicylic acid, boron complexes of benzilic acid, polymers containing sulfonic acid groups, fluorine-containing polymers, and polymers containing halogen-substituted aromatic rings.

Examples of fluidizing agents include silica, titania, alumina, calcium carbonate, fatty acid metal salts, silicone resin particles, and fluororesin particles, and two or more of them may be used in combination. From the viewpoint of the chargeability of the toner, silica is preferred. From the viewpoint of the transferability of the toner, it is also preferred that the silica is hydrophobic.

The content of the toner binder in the toner is preferably from 30 to 97% by weight, more preferably from 40 to 95% by weight, and even more preferably from 45 to 92% by weight, based on the weight of the toner.
The content of the colorant is preferably 0.05 to 60% by weight, more preferably 0.1 to 55% by weight, and even more preferably 0.5 to 50% by weight, based on the weight of the toner.
The content of the releasing agent is preferably 0 to 30% by weight, more preferably 0.5 to 20% by weight, and further preferably 1 to 10% by weight, based on the weight of the toner.
The content of the charge control agent is preferably 0 to 20% by weight, more preferably 0.1 to 10% by weight, and even more preferably 0.5 to 7.5% by weight, based on the weight of the toner.
The content of the fluidizing agent is preferably 0 to 10% by weight, more preferably 0 to 5% by weight, and further preferably 0.1 to 4% by weight, based on the weight of the toner.
The total content of the additives is preferably 3 to 70% by weight, more preferably 4 to 58% by weight, and even more preferably 5 to 50% by weight, based on the weight of the toner.
By setting the composition ratio of the toner in the above range, it is possible to easily obtain a toner having good charge retention rate (particularly charge retention rate under high temperature and high humidity conditions) and heat-resistant storage stability.

The toner may be obtained by any of the known methods such as a kneading and pulverizing method, an emulsion phase inversion method, and a polymerization method.
For example, when a toner is obtained by a kneading and pulverizing method, the components constituting the toner except for the fluidizing agent are dry-blended, melt-kneaded, then coarsely pulverized, and finally, the toner is pulverized using a jet mill pulverizer or the like, and further classified to obtain fine particles having a volume average particle size (D50) of preferably 5 to 20 μm, and then the fluidizing agent is mixed therein to produce the toner.
The volume average particle size (D50) is measured using a Coulter counter (for example, trade name: Multisizer III [manufactured by Beckman Coulter, Inc.]).

When obtaining toner by the emulsion phase inversion method, the components constituting the toner, excluding the fluidizing agent, are dissolved or dispersed in an organic solvent, and then emulsified by adding water, etc., and then separated and classified to produce the toner. The volume average particle size of the toner is preferably 3 to 15 μm.

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

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

The toner and toner binder of the present invention are used for developing electrostatic images or magnetic latent images in electrophotography, electrostatic recording, electrostatic printing, etc. More specifically, they are used for developing electrostatic images or magnetic latent images that are particularly suitable for full color.

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

<Production Example 1>
[Production of Polyester Resin (A1-1)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 721 parts of bisphenol A.PO 2 mole adduct, 101 parts of terephthalic acid, 53 parts of trimellitic anhydride, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and the mixture was reacted for 2 hours under a nitrogen stream at 230 ° C. while distilling off the water produced. Next, the mixture was reacted for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH / g, the temperature was lowered to 180 ° C. Further, 205 parts of adipic acid was added and reacted for 2 hours, and then the mixture was reacted for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value was 49 mgKOH / g, the mixture was taken out to obtain a polyester resin (A1-1).

<Production Example 2>
[Production of polyester resin (A1-2)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 695 parts of bisphenol A·EO 2 mole adduct, 182 parts of terephthalic acid, 12 parts of trimethylolpropane, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and the mixture was reacted for 2 hours under a nitrogen stream at 230°C while distilling off the water produced. Next, the mixture was reacted for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the temperature was lowered to 180°C. Further, 195 parts of adipic acid was added and reacted for 2 hours, and then reacted for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value was 28 mgKOH/g, the mixture was taken out to obtain a polyester resin (A1-2).

<Production Example 3>
[Production of polyester resin (A1-3)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 135 parts of bisphenol A PO 2 mole adduct, 604 parts of bisphenol A PO 3 mole adduct, 130 parts of terephthalic acid, 76 parts of adipic acid, 28 parts of trimellitic anhydride were added, and 2.5 parts of titanium diisopropoxy bistriethanol aminate was added as a condensation catalyst, and the mixture was reacted for 2 hours under a nitrogen stream at 230 ° C. while distilling off the water produced. Next, the mixture was reacted for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mg KOH / g, the temperature was lowered to 180 ° C. Further, 77 parts of trimellitic anhydride was added, and the mixture was reacted for 1 hour under normal pressure, and then removed to obtain a polyester resin (A1-3).

<Production Example 4>
[Production of polyester resin (A1-4)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 708 parts of bisphenol A·EO 2 mole adduct, 146 parts of terephthalic acid, 85 parts of adipic acid, 31 parts of trimellitic anhydride, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and reacted for 2 hours under a nitrogen stream at 230°C while distilling off the water produced. Next, the reaction was carried out for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the temperature was lowered to 180°C. 85 parts of trimellitic anhydride was placed, reacted for 1 hour under normal pressure, and then removed to obtain polyester resin (A1-4).

<Production Example 5>
[Production of polyester resin (A1-5)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 763 parts of bisphenol A·EO 2 mole adduct, 157 parts of terephthalic acid, 92 parts of adipic acid, 33 parts of trimellitic anhydride, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and reacted for 2 hours under a nitrogen stream at 230°C while distilling off the water produced. Next, the reaction was carried out for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the temperature was lowered to 180°C. Further, 13 parts of trimellitic anhydride was placed, and the reaction was carried out for 1 hour under normal pressure, followed by removal to obtain polyester resin (A1-5).

<Production Example 6>
[Production of polyester resin (A1-6)]
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 553 parts of 3-methyl-1,5-pentanediol, 19 parts of trimethylolpropane, 374 parts of terephthalic acid, 300 parts of adipic acid, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed and subjected to an esterification reaction under normal pressure at 220° C. After confirming that the acid value of the reaction product was less than 40 mgKOH/g, the reaction was carried out at 220° C. under a reduced pressure of 0.5 to 2.5 kPa for 5 hours, and 93 parts of 3-methyl-1,5-pentanediol and 155 parts of condensation water were recovered. Since the acid value confirmed at that point was less than 21 mgKOH/g, the reaction product was taken out, and a polyester resin (A1-6) was obtained.

<Production Example 7>
[Production of polyester resin (A1-7)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 703 parts of bisphenol A·EO 2 mole adduct, 145 parts of terephthalic acid, 85 parts of adipic acid, 31 parts of trimellitic anhydride, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and reacted for 2 hours under a nitrogen stream at 230°C while distilling off the water produced. Next, the reaction was carried out for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the temperature was lowered to 180°C. Further, 90 parts of trimellitic anhydride was placed, and the reaction was carried out for 1 hour under normal pressure, followed by removal to obtain polyester resin (A1-7).

The composition and physical properties of the polyester resin (A1) obtained in Production Examples 1 to 7 are shown in Table 1.

<Production Example 8>
[Production of polyester resin (B1-1)]
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 193 parts of bisphenol A·PO 2-mol adduct, 559 parts of bisphenol A·EO 2-mol adduct, 312 parts of terephthalic acid, and 2.5 parts of titanium diisopropoxy bistriethanol aminate as a condensation catalyst were placed and reacted for 2 hours under a nitrogen stream at 230° C. while distilling off the water produced. Next, the reaction was carried out for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the reaction product was taken out to obtain a polyester resin (B1-1).

<Production Example 9>
[Production of polyester resin (B1-2)]
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 684 parts of bisphenol A·PO 2-mol adduct, 85 parts of bisphenol A·PO 3-mol adduct, 261 parts of terephthalic acid, 29 parts of isophthalic acid, and 2.5 parts of titanium diisopropoxy bistriethanol aminate as a condensation catalyst were placed and reacted for 2 hours under a nitrogen stream at 230° C. while distilling off the water produced. Next, the reaction was carried out for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the reaction product was taken out to obtain a polyester resin (B1-2).

<Comparative Production Example 1>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 672 parts of bisphenol A·PO 2-mol adduct, 84 parts of bisphenol A·PO 3-mol adduct, 257 parts of terephthalic acid, 29 parts of isophthalic acid, and 2.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed and reacted for 2 hours under a nitrogen stream at 230°C while distilling off the water produced. Next, the reaction was carried out for 5 hours under a reduced pressure of 0.5 to 2.5 kPa, and after confirming that the acid value of the reaction product was less than 1 mgKOH/g, the temperature was lowered to 180°C. Further, 17 parts of trimellitic anhydride was placed and reacted for 1 hour under normal pressure, and then removed to obtain polyester resin (B1'-1).

The compositions and physical properties of polyester resin (B1) and polyester resin (B1') obtained in Production Examples 8 and 9 and Comparative Production Example 1 are shown in Table 2.

<Production Example 10>
[Production of vinyl resin (B2-1)]
138 parts of xylene was charged into an autoclave, and after replacing with nitrogen, the temperature was raised to 165°C in a sealed state with stirring. A mixed solution of 450 parts of behenyl acrylate [manufactured by NOF Corp., the same applies below], 150 parts of styrene [manufactured by Idemitsu Kosan Co., Ltd., the same applies below], 150 parts of acrylonitrile [manufactured by Nacalai Tesque Co., Ltd., the same applies below], 1.0 part of di-t-butyl peroxide [Perbutyl D, manufactured by NOF Corp., the same applies below], and 100 parts of xylene was adjusted to 60°C, and while controlling the temperature inside the autoclave to 165°C, polymerization was performed by dropping it over 3 hours. After dropping, the dropping line was washed with 12 parts of xylene. The temperature was further maintained at the same temperature for 0.5 hours, and the reaction rate of monomer (a) was confirmed. Since the reaction rate of the monomer (a) was less than 95%, 0.5 parts of di-t-butyl peroxide was further added to react until the reaction rate reached 95% or more. The solvent was removed at 165° C. for 5 hours under reduced pressure of 0.5 to 2.5 kPa to obtain a crystalline vinyl resin (B2-1).

<Production Example 11>
[Production of vinyl resin (B2-2)]
138 parts of xylene was charged into the autoclave, and after replacing with nitrogen, the temperature was raised to 165°C in a sealed state with stirring. A mixed solution of 525 parts of stearyl acrylate [manufactured by NOF Corp., the same applies below], 150 parts of styrene, 75 parts of acrylonitrile, 0.2 parts of di-t-butyl peroxide, and 100 parts of xylene was adjusted to 60°C, and while controlling the temperature inside the autoclave to 165°C, it was dropped over 3 hours to polymerize. After dropping, the dropping line was washed with 12 parts of xylene. The same temperature was maintained for another 0.5 hours, and the reaction rate of monomer (a) was confirmed. Since the reaction rate of monomer (a) was less than 95%, 0.1 parts of di-t-butyl peroxide was further added and reacted until the reaction rate reached 95% or more. The solvent was removed at 165°C for 5 hours under reduced pressure of 0.5 to 2.5 kPa to obtain a crystalline vinyl resin (B2-2).

<Production Example 12>
[Synthesis of triacontyl acrylate]
A reaction vessel equipped with a stirring device, a heating/cooling device, a thermometer, an air inlet tube, a pressure reducing device, and a water reducing device was charged with 50 parts of 1-triacontanol, 50 parts of toluene, 12 parts of acrylic acid, and 0.05 parts of hydroquinone, and stirred to homogenize. Then, 2 parts of paratoluenesulfonic acid was added, and after stirring for 30 minutes, the mixture was reacted for 5 hours while removing water generated at 100 ° C. while blowing air at a flow rate of 30 mL / min. Thereafter, the pressure in the reaction vessel was adjusted to 300 mmHg, and the reaction was continued for another 3 hours while removing water generated. After cooling the reaction solution to room temperature, 30 parts of a 10 wt% aqueous sodium hydroxide solution was added, and the mixture was stirred for 1 hour, and then allowed to stand to separate the organic phase and the aqueous phase. The organic phase was collected by liquid separation and centrifugation, and 0.01 parts of hydroquinone was added, and the solvent was removed under reduced pressure while blowing air, to obtain triacontyl acrylate.

<Production Example 13>
[Production of vinyl resin (B2-3)]
138 parts of xylene was charged into the autoclave, and after replacing with nitrogen, the temperature was raised to 165 ° C. in a sealed state under stirring. A mixed solution of 600 parts of triacontyl acrylate obtained in Production Example 12, 75 parts of styrene, 75 parts of butyl acrylate [manufactured by Mitsubishi Chemical Corporation, the same applies below], 1.5 parts of di-t-butyl peroxide, and 100 parts of xylene was adjusted to 60 ° C., and while controlling the temperature inside the autoclave to 165 ° C., it was dropped over 3 hours to carry out polymerization. After dropping, the dropping line was washed with 12 parts of xylene. The temperature was further maintained at the same temperature for 0.5 hours, and the reaction rate of monomer (a) was confirmed. Since the reaction rate of monomer (a) was less than 95%, 0.5 parts of di-t-butyl peroxide was further added and reacted until the reaction rate reached 95% or more. The solvent was removed at 165° C. for 5 hours under a reduced pressure of 0.5 to 2.5 kPa to obtain a crystalline vinyl resin (B2-3).

<Production Example 14>
[Production of vinyl resin (B2-4)]
138 parts of xylene was charged into the autoclave, and after replacing with nitrogen, the temperature was raised to 165°C in a sealed state with stirring. A mixed solution of 300 parts of behenyl acrylate, 150 parts of stearyl acrylate, 125 parts of acrylonitrile, 75 parts of butyl acrylate, 100 parts of methyl methacrylate [manufactured by Sumitomo Chemical Co., Ltd., the same applies below], 0.5 parts of di-t-butyl peroxide, and 100 parts of xylene was adjusted to 60°C, and while controlling the temperature inside the autoclave to 165°C, it was dropped over 3 hours to carry out polymerization. After dropping, the dropping line was washed with 12 parts of xylene. The temperature was further maintained for 0.5 hours, and the reaction rate of monomer (a) was confirmed. Since the reaction rate of monomer (a) was less than 95%, 0.2 parts of di-t-butyl peroxide was further added and reacted until the reaction rate reached 95% or more. The solvent was removed at 165° C. for 5 hours under a reduced pressure of 0.5 to 2.5 kPa to obtain a crystalline vinyl resin (B2-4).

<Production Example 15>
[Production of vinyl resin (B2-5)]
138 parts of xylene was charged into the autoclave, and after replacing with nitrogen, the temperature was raised to 165°C in a sealed state with stirring. A mixed solution of 450 parts of behenyl acrylate, 75 parts of styrene, 225 parts of acrylonitrile, 0.5 parts of di-t-butyl peroxide, and 100 parts of xylene was adjusted to 60°C, and while controlling the temperature inside the autoclave to 165°C, it was dropped over 3 hours to polymerize. After dropping, the dropping line was washed with 12 parts of xylene. The same temperature was maintained for another 0.5 hours, and the reaction rate of monomer (a) was confirmed. Since the reaction rate of monomer (a) was less than 95%, 2.0 parts of di-t-butyl peroxide was further added, and the reaction was continued until the reaction rate reached 95% or more. The solvent was removed at 165°C for 5 hours under reduced pressure of 0.5 to 2.5 kPa to obtain a crystalline vinyl resin (B2-5).

The composition and physical properties of the vinyl resin (B2) obtained in Production Examples 10 to 15 are shown in Table 3.

Example 1: Production of toner binder (C-1)
50 parts of polyester resin (A1-1), 50 parts of polyester resin (B1-1), 2.2 parts of jER157S70 [bisphenol A novolac type epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 209, the same below] (E-1) and 0.1 parts of imidazole [manufactured by Fujifilm Wako Pure Chemical Industries, the same below] (F-1) were mixed, fed to a twin-screw kneader [Kurimoto Iron Works, Ltd., S5KRC kneader] at 80 kg/hour, and kneaded and extruded at 180°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-1). The glass transition temperature Tg _C of (C-1) was 49.9°C, the acid value was 17.9 mgKOH/g, and the reaction rate was 99%.

Example 2: Production of toner binder (C-2)
50 parts of polyester resin (A1-2), 50 parts of polyester resin (B1-2), 2.1 parts of jER157S70 (E-1) and 0.1 parts of 2-ethyl-4-methylimidazole [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., the same applies below] (F-3) were mixed, fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 180°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-2). The glass transition temperature Tg _C of (C-2) was 46.1°C, the acid value was 8.5 mgKOH/g, and the reaction rate was 98%.

Example 3: Production of toner binder (C-3)
70 parts of polyester resin (A1-3), 30 parts of polyester resin (B1-1), 5.5 parts of jER157S70 (E-1) and 0.2 parts of 2-phenylimidazole [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., the same applies below] (F-2) were mixed, fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 160°C and 90 rpm for 2 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-3). The glass transition temperature Tg _C of (C-3) was 53.0°C, the acid value was 14.4 mgKOH/g, and the reaction rate was 97%.

Example 4: Production of toner binder (C-4)
70 parts of polyester resin (A1-4), 30 parts of polyester resin (B1-1), 6.0 parts of jER157S70 (E-1) and 0.2 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 150°C and 90 rpm for 2 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-4). The glass transition temperature Tg _C of (C-4) was 54.9°C, the acid value was 15.9 mgKOH/g, and the reaction rate was 95%.

Example 5: Production of toner binder (C-5)
70 parts of polyester resin (A1-4), 30 parts of polyester resin (B1-1), 5.5 parts of EPPN-201 [phenol novolac type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 193, the same applies below] (E-2) and 0.2 parts of imidazole (F-1) were mixed, fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 150°C and 90 rpm for 2 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-5). The glass transition temperature Tg _C of (C-5) was 55.0°C, the acid value was 15.5 mgKOH/g, and the reaction rate was 99%.

Example 6: Production of toner binder (C-6)
70 parts of polyester resin (A1-3), 30 parts of polyester resin (B1-1), 5.5 parts of jER157S70 (E-1) and 0.4 parts of 2-phenylimidazole (F-2) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 160°C and 90 rpm for 3 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-6). The glass transition temperature Tg _C of (C-6) was 53.3°C, the acid value was 14.5 mgKOH/g, and the reaction rate was 96%.

Example 7: Production of toner binder (C-7)
40 parts of polyester resin (A1-4), 60 parts of polyester resin (B1-2), 17.6 parts of jER1004 [bisphenol A type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 897, the same applies below] (E-3) and 0.2 parts of 2-ethyl-4-methylimidazole (F-3) were mixed, fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 150°C and 90 rpm for 15 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-7). The glass transition temperature Tg _C of (C-7) was 54.5°C, the acid value was 6.7 mgKOH/g, and the reaction rate was 96%.

Example 8: Production of toner binder (C-8)
50 parts of polyester resin (A1-1), 50 parts of crystalline vinyl resin (B2-1), 4.7 parts of jER157S70 (E-1) and 0.1 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hr, and kneaded and extruded at 180°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-8). The endothermic peak top temperature Tm of (C-8) was 58.1°C, the glass transition temperature Tg _C was 38.2°C, the acid value was 11.4 mgKOH/g, and the reaction rate was 96%.

Example 9: Production of toner binder (C-9)
70 parts of polyester resin (A1-2), 30 parts of crystalline vinyl resin (B2-2), 5.1 parts of jER157S70 (E-1) and 0.2 parts of 2-phenylimidazole (F-2) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 180°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-9). The endothermic peak top temperature Tm _C of (C-9) was 46.2°C, the glass transition temperature Tg _C was 34.6°C, the acid value was 6.3 mgKOH/g, and the reaction rate was 96%.

Example 10: Production of toner binder (C-10)
70 parts of polyester resin (A1-2), 30 parts of crystalline vinyl resin (B2-3), 5.1 parts of jER157S70 (E-1) and 0.2 parts of 2-ethyl-4-methylimidazole (F-3) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 180°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-10). The endothermic peak top temperature Tm _C of (C-10) was 88.8°C, the glass transition temperature Tg _C was 34.8°C, the acid value was 6.4 mgKOH/g, and the reaction rate was 95%.

Example 11: Production of toner binder (C-11)
50 parts of polyester resin (A1-3), 50 parts of crystalline vinyl resin (B2-4), 3.7 parts of EPPN-201 (E-2) and 0.2 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hr, and kneaded and extruded at 150°C and 90 rpm for 2 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-11). The endothermic peak top temperature Tm _C of (C-11) was 57.1°C, the glass transition temperature Tg _C was 50.8°C, the acid value was 10.4 mgKOH/g, and the reaction rate was 96%.

Example 12: Production of toner binder (C-12)
40 parts of polyester resin (A1-2), 60 parts of crystalline vinyl resin (B2-5), 10.8 parts of jER1004 (E-3) and 0.1 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 160°C and 90 rpm for 6 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-12). The endothermic peak top temperature Tm _C of (C-12) was 59.2°C, the glass transition temperature Tg _C was 34.2°C, the acid value was 4.4 mgKOH/g, and the reaction rate was 95%.

Example 13: Production of toner binder (C-13)
30 parts of polyester resin (A1-4), 70 parts of crystalline vinyl resin (B2-1), 4.3 parts of jER157S70 (E-1) and 0.2 parts of 2-ethyl-4-methylimidazole (F-3) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 150°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-13). The endothermic peak top temperature Tm _C of (C-13) was 59.3°C, the glass transition temperature Tg _C was 54.1°C, the acid value was 10.7 mgKOH/g, and the reaction rate was 95%.

Example 14: Production of toner binder (C-14)
In a reaction tank equipped with a stirrer, 70 parts of polyester resin (A1-4), 30 parts of polyester resin (B1-1), 5.5 parts of EPPN-201 (E-2) and 0.4 parts of imidazole (F-1) were respectively charged and reacted while stirring at 104°C for 180 minutes, and then the mixture was taken out and cooled to obtain toner binder (C-14). The glass transition temperature Tg _C of (C-14) was 55.6°C, the acid value was 16.6 mgKOH/g and the reaction rate was 91%.

Example 15: Production of toner binder (C-15)
70 parts of polyester resin (A1-5), 30 parts of polyester resin (B1-1), 1.4 parts of EHPE-3150 [1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, manufactured by Daicel Corporation, epoxy equivalent 174, the same applies below] (E-4) and 0.2 parts of imidazole (F-1) were mixed, fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 199°C and 90 rpm for 15 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-15). The glass transition temperature Tg _C of (C-15) was 44.2°C, the acid value was 1.4 mgKOH/g, and the reaction rate was 92%.

Example 16: Production of toner binder (C-16)
40 parts of polyester resin (A1-6), 60 parts of crystalline vinyl resin (B2-5), 2.1 parts of jER157S70 (E-1) and 0.2 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hr, and kneaded and extruded at 185°C and 90 rpm for 16 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-16). The endothermic peak top temperature Tm _C of (C-16) was 59.1°C, the glass transition temperature Tg _C was -34.6°C, the acid value was 2.2 mgKOH/g, and the reaction rate was 95%.

Example 17: Production of toner binder (C-17)
70 parts of polyester resin (A1-7), 30 parts of polyester resin (B1-1), 6.5 parts of jER157S70 (E-1) and 0.2 parts of 2-phenylimidazole (F-2) were mixed and fed to a twin-screw kneader at 80 kg/hr, and kneaded and extruded at 150°C and 90 rpm for 3 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C-17). The glass transition temperature Tg _C of (C-17) was 57.2°C, the acid value was 15.9 mgKOH/g, and the reaction rate was 95%.

Comparative Example 1: Production of Toner Binder (C'-1)
50 parts of polyester resin (A1-2), 50 parts of polyester resin (B1'-1), 3.0 parts of jER157S70 (E-1) and 0.1 parts of 2-ethyl-4-methylimidazole (F-3) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 180°C and 90 rpm for 5 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C'-1). The glass transition temperature Tg _C of (C'-1) was 48.3°C, the acid value was 10.8 mgKOH/g, and the reaction rate was 96%.

Comparative Example 2 [Production of Toner Binder (C'-2)]
50 parts of polyester resin (A1-1), 50 parts of polyester resin (B1-1), and 2.4 parts of jER157S70 (E-1) were mixed and fed to a twin-screw kneader at 80 kg/hour, and kneaded and extruded at 180°C and 90 rpm for 60 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C'-2). The glass transition temperature Tg _C of (C'-2) was 49.7°C, the acid value was 17.9 mgKOH/g, and the reaction rate was 90%.

Comparative Example 3: Production of Toner Binder (C'-3)
100 parts of polyester resin (B1-1), 2.4 parts of jER157S70 (E-1) and 0.1 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hr, and kneaded and extruded at 180°C and 90 rpm for 60 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C'-3). The glass transition temperature Tg _C of (C'-3) was 61.0°C, the acid value was 0.2 mgKOH/g, and the reaction rate was 0%.

Comparative Example 4: [Production of Toner Binder (C'-4)]
50 parts of polyester resin (A1-1), 50 parts of crystalline vinyl resin (B2-1) and 0.1 parts of imidazole (F-1) were mixed and fed to a twin-screw kneader at 80 kg/hr, and kneaded and extruded at 180°C and 90 rpm for 60 minutes to carry out a crosslinking reaction. The mixture was cooled to obtain a toner binder (C'-4). The endothermic peak top temperature Tm _C of (C'-4) was 59.8°C, the glass transition temperature Tg _C was 38.8°C, the acid value was 24.1 mgKOH/g, and the reaction rate was 0%.

Comparative Example 5 [Production of Toner Binder (C'-5)]
In a reaction tank equipped with a stirrer, 70 parts of polyester resin (A1-4), 30 parts of polyester resin (B1-1), and 5.5 parts of EPPN-201 (E-2) were each charged and reacted while stirring at 104°C for 180 minutes, after which the mixture was taken out and cooled to obtain toner binder (C'-5). (C'-5) had a glass transition temperature Tg _C of 55.4°C, an acid value of 27.4 mgKOH/g, and a reaction rate of 20%.

The compositions and physical properties of the toner binders (C) and (C') obtained in Examples 1 to 17 and Comparative Examples 1 to 5 are shown in Table 4.

The reaction rate of the toner binder was calculated by the following formula.
Reaction rate = (AV _ini - AV _C ) / (AV _ini - AV _fin ) x 100 (%),
AV _ini = (AV _A1 ×W _A1 +AV _B ×W _B )/W _tot
AV _fin = [AV _A1 × W _A1 + AV _B × W _B - (56100/E _Q ) × W _E ]/W _tot
AV _A1 : Acid value of polyester resin (A1),
AV _C : acid value of the toner binder (C),
W _A1 : parts by weight of polyester resin (A1),
W _B : weight part of resin (B),
W _E : weight part of epoxy resin (E),
W _tot : Total weight parts of polyester resin (A1), resin (B), epoxy compound (E), and catalyst (F) E _Q : Epoxy equivalent of (E)

<Toner Production>
To 88 parts of the toner binder [the toner binder obtained in each of the Examples and Comparative Examples], 7 parts of a pigment carbon black [MA-100, manufactured by Mitsubishi Chemical Corporation], 3 parts of a release agent carnauba wax, and 1 part of a charge control agent [T-77, manufactured by Hodogaya Chemical Co., Ltd.] were added, and a toner was prepared by the following method.
First, the mixture was premixed using a Henschel mixer [FM10B, manufactured by Nippon Coke & Engineering Co., Ltd.], and then kneaded using a twin-screw kneader [PCM-30, manufactured by Ikegai Co., Ltd.]. Then, the mixture was finely pulverized using a supersonic jet pulverizer, Labojet [KJ-25, manufactured by Kurimoto Iron Works Ltd.], and then classified using an elbow jet classifier [EJ-L-3 (LABO) type, manufactured by Matsubo Co., Ltd.] to obtain toner particles having a volume average particle size D50 of 7 μm.
Next, 100 parts of the toner particles were mixed with 1 part of hydrophobic silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) as a fluidizing agent in a sample mill to obtain a toner.

The composition and evaluation results of the toners using the toner binders obtained in each Example and Comparative Example are shown in Table 5. In addition, in Table 5, the toners obtained using the toner binders (C-1) to (C-17) of Examples 1 to 17 are shown as (T-1) to (T-17), and the toners obtained using the toner binders (C'-1) to (C'-5) of Comparative Examples 1 to 5 are shown as (T'-1) to (T'-5), respectively.

[Toner Performance Evaluation]
The methods for evaluating the low temperature fixing property, hot offset resistance, heat resistance storage stability, charge retention rate (low temperature and low humidity conditions and high temperature and high humidity conditions), water resistance, image strength, odor and durability of the obtained toners (T-1) to (T-17) and (T'-1) to (T'-5) will be described below, along with the criteria for evaluation.

<Low temperature fixability>
The toner was uniformly placed on the paper surface to a concentration of 1.0 mg/ ^cm2 . The powder was placed on the paper surface using a printer without a thermal fixing device. The paper was passed through a soft roller at a fixing speed (heating roller peripheral speed) of 213 mm/sec and at a heating roller temperature range of 90 to 200°C in 5°C increments. The fixed image was then visually inspected for the presence or absence of cold offset, and the cold offset occurrence temperature (MFT) was measured.
The lower the temperature at which cold offset occurs, the better the low-temperature fixing ability. Under these evaluation conditions, it is generally preferable that the MFT is 120° C. or less.

<Hot offset resistance>
Using the same method as described above for low-temperature fixability, the toner was placed on the paper surface, and the paper was passed through a soft roller at a fixing speed (heating roller peripheral speed) of 213 mm/sec, and at a heating roller temperature range of 90 to 200° C. in increments of 5° C. Next, the presence or absence of hot offset on the fixed image was visually observed, and the temperature at which hot offset occurred was measured.
A higher hot offset occurrence temperature means better hot offset resistance. In this evaluation condition, a temperature of 180° C. or higher is preferable.

<Heat-resistant storage stability>
1 g of the toner and 0.01 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed for 1 hour using a shaker. The mixture was placed in a sealed container and allowed to stand for 48 hours in an atmosphere at a temperature of 40° C. and a humidity of 80%, and the cohesion was measured using a powder tester to evaluate the heat resistance storage stability.
The lower the value in the cohesion test obtained by the following method, the more excellent the heat-resistant storage stability. Under these evaluation conditions, a value of 5% or less is preferable.
Equipment: POWDER TESTER model PT-X (manufactured by Hosokawa Micron)
Sieve openings: 355 μm, 250 μm, 150 μm
Vibration amplitude: 1mm
Vibration time: 30 seconds Operation method: Sieves were set on the vibration table of the powder tester in the following order: upper sieve 355 μm, middle sieve 250 μm, lower sieve 150 μm. 1 g of toner was placed on the upper sieve and vibrated with a vibration amplitude of 1 mm for 30 seconds. The weight of the toner remaining on each sieve was measured.
Cohesion degree: Calculated from the weight of the toner used in the measurement and the weight of the toner remaining after sieving.
Cohesion degree (%) = (U/N + M/N x 3/5 + L/N x 1/5) x 100
U: weight of upper stage, M: weight of middle stage, L: weight of lower stage, N: weight of sample (1g)

<Charge retention rate (low temperature and low humidity conditions and high temperature and high humidity conditions)>
(1) 1 g of toner and 0.01 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed for 1 hour using a shaker. 0.5 g of this mixture and 20 g of ferrite carrier (F-150, manufactured by Powder Tech Co., Ltd.) were placed in a 50 mL glass bottle, which was then conditioned at 23°C and 50% relative humidity for 8 hours (referred to as low temperature and low humidity conditions). Similarly, the bottle was conditioned at 50°C and 95% relative humidity for 24 hours (referred to as high temperature and high humidity conditions).
(2) The mixture was subjected to friction stirring at 50 rpm for 10 minutes and 60 minutes using a Turbulent shaker mixer, and the charge amount after each time was measured using a blow-off charge amount measuring device (manufactured by Kyocera Chemical Corporation).
Using the obtained values, "charge amount after 60 minutes of friction/charge amount after 10 minutes of friction" was calculated, and this was taken as the charge stability index.
A larger charge stability index indicates a more excellent charge retention rate. Under these evaluation conditions, a charge stability index of 0.8 or more is preferable.

<Water resistance>
(1) 1 g of toner and 0.01 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed for 1 hour using a shaker. 0.5 g of this mixture and 20 g of ferrite carrier (F-150, manufactured by Powder Tech Co., Ltd.) were placed in a 50 mL glass bottle, and this was conditioned at 50° C. and a relative humidity of 95% for 24 hours.
(2) The degree of blocking was visually determined, and the water resistance was evaluated according to the following criteria.

[Judgment criteria]
◯: No blocking occurred at all, and water resistance was excellent.
△: Blocking occurred in some areas, but water resistance was excellent.
×: Blocking occurred throughout the entire surface, and water resistance was poor.

<Image Intensity>
Among the images fixed in the above-mentioned evaluation of low-temperature fixability, the image with the lowest fixing temperature was subjected to a scratch hardness test in accordance with JIS K5600-5-4 (1999) by applying a load of 10 g from directly above a pencil fixed at an angle of 45 degrees by hand scratching, and the image strength was evaluated from the pencil hardness at which the image was not scratched.
A higher pencil hardness means better image strength. Generally, a pencil hardness of HB or higher is preferred.

<Odor>
1.0 g of the toner was placed in a glass test tube with a lid (φ15 mm×150 mm), sealed, and heated for 5 minutes at 210° C. Thereafter, the lid was removed, and 10 monitors checked the odor and evaluated it according to the following criteria.
[Judgment criteria]
○: 0-1 person answered that it smells bad △: 2-6 people answered that it smells bad ×: 7 or more people answered that it smells bad

<Durability>
Using the toner as a two-component developer, continuous copies were made using a commercially available monochrome copying machine [AR5030, manufactured by Sharp Corporation], and durability was evaluated according to the following criteria.

[Judgment criteria]
.circle.: No change in image quality or occurrence of fogging even after 10,000 copies.
A: Fog occurred on the 10,000th copy.
Δ: Fog occurred on the 6,000th copy.
x: Fog occurred on the 2,000th copy.

As is clear from the evaluation results in Table 5, the toners (T-1) to (T-17) using the toner binders produced in each Example obtained excellent results in all performance evaluations. On the other hand, the toners (T'-1) to (T'-5) using the toner binders produced in each Comparative Example were poor in some performance items. Specifically, Comparative Example 1 used a toner binder in which polyester resin (A1) was epoxy-crosslinked in polyester resin (B1) having an acid value, and the epoxy crosslinking reduced the low viscosity component, resulting in poor low-temperature fixability. Comparative Example 2 did not use catalyst (F), and had poor performance in both charge retention rate and odor. Comparative Example 3 did not use polyester resin (A1), and had poor performance in each of hot offset resistance, charge retention rate, water resistance, image strength, and durability. Comparative Example 4 did not use epoxy compound (E), and had poor performance in each of hot offset resistance, heat resistance storage stability, charge retention rate, water resistance, image strength, and durability. In Comparative Example 5, no catalyst (F) was used, and the performance was poor in each of hot offset resistance, heat resistance storage stability, charge retention rate, water resistance, image strength, and durability.

The toner binder of the present invention is excellent in heat resistance storage stability, charge retention rate (particularly charge retention rate under high temperature and high humidity conditions), water resistance, image strength, odor and durability while maintaining low temperature fixing property and hot offset resistance, and can be suitably used as a toner for developing electrostatic images used in electrophotography, electrostatic recording, electrostatic printing, etc.
Further, it is suitable for use as an additive for paints, an additive for adhesives, particles for electronic paper, and the like.

Claims (6)

1. A method for producing a toner binder, comprising the step of reacting a polyester resin (A1) having an acid value of 1 mgKOH/g or more, measured by a method specified in JIS K0070 , with an epoxy compound (E) in the presence of a resin (B) having an acid value of less than 1 mgKOH/g, measured by a method specified in JIS K0070, and a catalyst (F), wherein the resin (B) is a polyester resin (B1) and/or a vinyl resin (B2), the vinyl resin (B2) is a crystalline vinyl resin that is a polymer having, as a constituent monomer, a monomer (a) which is a (meth)acrylate having 21 to 40 carbon atoms and a chain hydrocarbon group and/or a vinyl ester having 21 to 40 carbon atoms, and the catalyst (F) is a compound represented by the following general formula (1):

[In general formula (1), R ¹ to R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group.] The method for producing a toner binder according to claim 1, wherein the reaction temperature of the polyester resin (A1) and the epoxy compound (E) is 100 to 200°C. The method for producing a toner binder according to claim 1 or 2, wherein the epoxy compound (E) is a multifunctional epoxy compound having an epoxy equivalent of 170 to 900. The method for producing a toner binder according to any one of claims 1 to 3, wherein the acid value of the polyester resin (A1) is 7.0 to 50.0 mg KOH/g. The method for producing a toner binder according to any one of claims 1 to 4, wherein the glass transition temperature of the polyester resin (A1) is -35 to 55°C. The method for producing a toner binder according to any one of claims 1 to 5, wherein the weight ratio of the polyester resin (A1) to the epoxy compound (E) [(A1):(E)] is 65:35 to 98:2.