JP7463481B2 - Toner Binder - Google Patents

Description

The present invention relates to a toner binder.

2. Description of the Related Art In recent years, with the development of electrophotographic systems, the demand for electrophotographic apparatuses such as copying machines and laser printers has increased rapidly, and the requirements for their performance have also become more sophisticated.
For full-color electrophotography, there have been known methods and apparatuses in which an image forming process is repeated 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 the toner image is then transferred onto a transfer material, and the toner image on the transfer material is then heated and fixed to obtain a multi-color image.

To pass through these processes without any problems, the toner needs to have good fixability to the paper. In addition, since the device has a heater in the fixing section and the temperature rises inside the device, the toner needs to not block inside the device.

Furthermore, in order to promote the miniaturization, high speed and high image quality of electrophotographic devices, as well as to conserve energy by reducing the energy consumed in the fixing process, there is a strong demand for improved low-temperature fixing properties of toner.

Recently, many types of paper are used as transfer materials, including recycled paper with a rough surface and coated paper with a smooth surface. To accommodate the surface properties of these transfer materials, fixing devices with a wide nip width, such as soft rollers or belt rollers, are preferably used. However, widening the nip width increases the contact area between the toner and the fixing roller, causing the so-called high-temperature offset phenomenon in which molten toner adheres to the fixing roller, so offset resistance is required.

In addition to the above, multi-color images (full color) require a much higher gloss than black-and-white images (monochrome) in order to reproduce photographic images, etc., and it is necessary to ensure that the toner layer of the resulting image is smooth.
Therefore, it is necessary to develop low-temperature fixability while maintaining high gloss and offset resistance, and there is a demand for toner images with high gloss over a wide working range.

In order to realize the above-mentioned properties, a toner binder has been proposed that uses a crystalline vinyl resin having excellent sharp melting properties in combination with a polyester resin crosslinked by carbon-carbon bonds (Patent Document 1).
However, when the particle size of the toner is reduced to meet the demand for even higher image quality, the toner using the above-mentioned toner binder does not have sufficient charge rise property and gloss due to the dispersibility of the polyester resin in the toner, and improvements in these areas are desired.

International Publication No. 2019/073731

The present invention aims to provide a toner binder and toner that are excellent in heat resistance, gloss, and charge rise while maintaining low-temperature fixing properties and hot offset resistance.

The present inventors conducted extensive research to solve these problems and arrived at the present invention.
That is, the present invention provides a toner binder containing a polyester resin (A), a crystalline vinyl resin (B) and a polyethylene glycol fatty acid ester (C), wherein the polyester resin (A) is a resin in which a polyester (A1) is crosslinked by a carbon-carbon bond, the crystalline vinyl resin (B) is a polymer containing a monomer (a) as an essential constituent monomer, the monomer (a) is a (meth)acrylate having 21 to 40 carbon atoms and a chain-like hydrocarbon group, the polyester resin (A) is dispersed in the toner binder as particles, and the number average particle diameter of the polyester resin (A) in the toner binder is 0.1 to 7.5 μm.

The present invention makes it possible to provide a toner binder and toner that are excellent in heat resistance, gloss, and charge rise while maintaining low-temperature fixing properties and hot offset resistance.

The toner binder of the present invention contains a polyester resin (A), a crystalline vinyl resin (B) and a polyethylene glycol fatty acid ester (C), wherein the polyester resin (A) is a resin in which a polyester (A1) is crosslinked by a carbon-carbon bond, the crystalline vinyl resin (B) is a polymer containing a monomer (a) as an essential constituent monomer, the monomer (a) is a (meth)acrylate having 21 to 40 carbon atoms and a chain hydrocarbon group, the polyester resin (A) is dispersed in the toner binder as particles, and the number average particle diameter of the polyester resin (A) in the toner binder is 0.1 to 7.5 μm.
The toner binder of the present invention will be described below in order.

The toner binder of the present invention contains, as an essential component, a polyester resin (A) which is a resin in which a polyester (A1) is crosslinked by a carbon-carbon bond.
The polyester resin (A) is a resin having a structure in which the polyester (A1) is crosslinked by a carbon-carbon bond. The crosslink by the carbon-carbon bond is formed by directly bonding at least one of the carbon atoms contained in the polyester (A1) molecule to another carbon atom contained in the polyester (A1).
The polyester (A1) referred to here is not particularly limited, and may be any polyester that can be crosslinked by carbon-carbon bonds.
Among these, from the viewpoint of easiness in forming a crosslinked structure, polyester (A11) having a carbon-carbon double bond is preferred.
It is also preferred that at least a part of the crosslinks due to carbon-carbon bonds in the polyester resin (A) is a carbon-carbon bond formed by bonding a carbon atom that constituted one carbon-carbon double bond present in the polyester (A11) molecule to a carbon atom that constituted another carbon-carbon double bond present in the polyester (A11) molecule.
The one carbon-carbon double bond and the other carbon-carbon double bond may be present in the same polyester (A11) molecule or may be present in different polyester (A11) molecules.
The polyester resin (A) can be obtained by reacting the carbon-carbon double bonds of the polyester (A11) or by a method in which hydrogen atoms bonded to carbon atoms contained in the polyester (A1) are abstracted by a hydrogen abstraction reaction due to heating or the like to cause crosslinking (also referred to as hydrogen atom abstraction reaction).

Examples of the form of the crosslinking reaction that forms a carbon-carbon bond include a reaction in which an unsaturated double bond is introduced into the main chain or side chain of a polyester resin, and reacted by a radical addition reaction, a cation addition reaction, an anion addition reaction, or the like to form an intermolecular carbon-carbon bond, and a reaction in which an intermolecular carbon-carbon bond is formed by a hydrogen atom abstraction reaction using a peroxide or the like.
In addition, since the polyester resin in which a network has been formed by the above-mentioned crosslinking reaction cannot be dissolved in tetrahydrofuran (hereinafter, "tetrahydrofuran" may be abbreviated as THF), whether the polyester resin is a polyester resin in which a network has been formed by a crosslinking reaction can be confirmed by dissolving the polyester resin in THF and finding that it has a component insoluble in THF (THF-insoluble portion).

The polyester resin (A) used in the toner binder of the present invention is a resin obtained by crosslinking a polyester (A1) through a crosslinking reaction that generates a carbon-carbon bond. Among these crosslinking reaction forms, the crosslinking reaction that generates a carbon-carbon bond is preferably a method in which a polyester (A11) having a carbon-carbon double bond is reacted through a radical addition reaction, a cationic addition reaction, an anionic addition reaction, or the like to generate an intermolecular carbon-carbon bond, from the viewpoint of grindability and low-temperature fixability.
The polyester resin (A) may have crosslinks due to carbon-carbon bonds, and may also have crosslinks due to ester bonds, crosslinks due to polyaddition reactions, or crosslinks due to both.

The polyester resin (A) may consist of one type of polyester resin or may be a mixture of two or more types of polyester resins.

In the toner binder of the present invention, the polyester (A11) having a carbon-carbon double bond preferably contains an unsaturated carboxylic acid component (y) and/or an unsaturated alcohol component (z) and is a polyester resin obtained by polycondensation of a component having either the unsaturated carboxylic acid component (y) or the unsaturated alcohol component (z) as an essential component.
Furthermore, the polyester (A11) having a carbon-carbon double bond may contain, in addition to the above essential components, a saturated alcohol component (x) and a saturated carboxylic acid component (w) as constituents.
The polyester (A11) may be obtained by polycondensation of one of these components, or by polycondensation of a plurality of components.
In this specification, when determining whether a component is an unsaturated carboxylic acid component (y) or a saturated carboxylic acid component (w), bonds to aromatic rings and heterocyclic rings are not taken into consideration.
Similarly, the bonds of the aromatic ring and the heterocyclic ring are not taken into consideration in determining whether the alcohol component is an unsaturated alcohol component (z) or a saturated alcohol component (x).

Examples of the unsaturated alcohol component (z) include an unsaturated monol (z1) and an unsaturated diol (z2).
These may be used alone or in combination of two or more.

The unsaturated monool (z1) may be an unsaturated monool having 2 to 30 carbon atoms, and preferred examples include 2-propen-1-ol, palmitoleic alcohol, elaidyl alcohol, oleyl alcohol, erucyl alcohol, and 2-hydroxyethyl methacrylate.

The unsaturated diol (z2) may be an unsaturated diol having 2 to 30 carbon atoms, and a preferred example is ricinoleyl alcohol.

Examples of the saturated alcohol component (x) include saturated monools (x1), saturated diols (x2), and trihydric or higher saturated polyols (x3).
These may be used alone or in combination of two or more.

Examples of the saturated monool (x1) include linear or branched alkyl alcohols having 1 to 30 carbon atoms (e.g., methanol, ethanol, isopropanol, 1-decanol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and lignoceryl alcohol).
Among these saturated monools, from the viewpoint of heat resistance storage stability, preferred are linear or branched alkyl alcohols having 8 to 24 carbon atoms, more preferred are linear alkyl alcohols having 8 to 24 carbon atoms, and even more preferred are dodecyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol and lignoceryl alcohol.

Examples of the saturated diol (x2) include alkylene glycols having 2 to 36 carbon atoms (ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol, etc.) (x21), alkylene ether glycols having 4 to 36 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, glycol, polypropylene glycol, polytetramethylene ether glycol, etc.) (x22), alicyclic diols having 6 to 36 carbon atoms (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.) (x23), alkylene oxide (hereinafter, "alkylene oxide" may be abbreviated as AO) adducts of the above alicyclic diols (preferably, the average number of moles added is 1 to 30) (x24), aromatic diols [monocyclic dihydric phenols (e.g., hydroquinone, etc.) and bisphenols, etc.] (x25), and AO adducts of the above aromatic diols (preferably, the average number of moles added is 2 to 30) (x26).
Among these saturated diols (x2), from the viewpoints of low-temperature fixability and heat-resistant storage stability, alkylene glycols having 2 to 36 carbon atoms (x21) and AO adducts of aromatic diols (x26) are preferred, and AO adducts of bisphenols are more preferred.
The AO is preferably an alkylene group having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, 1,2-, 2,3- or iso-butylene oxide, and tetrahydrofuran). One type of AO may be used alone, or two or more types may be used in combination.

The bisphenols include those represented by the following general formula (1).
HO-Ar-P-Ar-OH (1)
In general formula (1), 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 represented by general formula (1) 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 these may be used alone or in combination of two or more.

From the viewpoints of heat-resistant storage stability and low-temperature fixability, EO and/or PO are preferred as the AO constituting the AO adduct of a bisphenol.
The average number of moles of AO added is preferably 2 to 30 moles, more preferably 2 to 10 moles, and further preferably 2 to 5 moles.
Among the AO adducts of bisphenols, preferred from the viewpoints of the fixing property, pulverizability and heat-resistant storage stability of the toner are EO adducts of bisphenol A (average number of moles added is preferably 2 to 4, more preferably 2 to 3) and/or PO adducts (average number of moles added is preferably 2 to 4, more preferably 2 to 3).

Examples of trivalent or higher saturated polyols (x3) include aliphatic polyhydric alcohols having 3 to 36 carbon atoms and trivalent or higher (x31), sugars and their derivatives (x32), AO adducts of aliphatic polyhydric alcohols (average number of moles added is preferably 1 to 30) (x33), AO adducts of trisphenols (trisphenol PA, etc.) (average number of moles added is preferably 2 to 30) (x34), and AO adducts of novolak resins (including phenol novolak and cresol novolak, etc., with an average degree of polymerization preferably 3 to 60) (average number of moles added is preferably 2 to 30) (x35).

Examples of the aliphatic polyhydric alcohol (x31) having 3 to 36 carbon atoms and having a valence of 3 or more include alkane polyols and their intramolecular or intermolecular dehydration products, such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, polyglycerin, and dipentaerythritol.
Examples of sugars and their derivatives (x32) include sucrose and methyl glucoside.

Of the trivalent or higher saturated polyols (x3), from the viewpoint of achieving both low-temperature fixing properties and hot offset resistance, trivalent or higher aliphatic polyhydric alcohols having 3 to 36 carbon atoms (x31) and AO adducts (average number of moles added is preferably 2 to 30) (x35) of novolak resins (including phenol novolak and cresol novolak, etc., with an average degree of polymerization preferably being 3 to 60).

Among the saturated alcohol components (x), from the viewpoint of achieving both low-temperature fixing property, hot offset resistance, and heat-resistant storage stability, preferred are alkylene glycols having 2 to 36 carbon atoms (x21), AO adducts of bisphenols (average number of moles added is preferably 2 to 30), aliphatic polyhydric alcohols having 3 to 36 carbon atoms and having a valence of 3 or more (x31), and AO adducts of novolak resins (including phenol novolak and cresol novolak, etc., with an average degree of polymerization preferably being 3 to 60) (average number of moles added is preferably 2 to 30) (x35).

From the viewpoint of heat-resistant storage stability, the saturated alcohol component (x) is preferably an alkylene glycol having 2 to 10 carbon atoms, an AO adduct of a bisphenol (average number of moles added is preferably 2 to 5), an aliphatic polyhydric alcohol having 3 to 36 carbon atoms with 3 to 8 valences, and an AO adduct of a novolak resin (including phenol novolak and cresol novolak, etc., with an average degree of polymerization preferably being 3 to 60) (average number of moles added is preferably 2 to 30), and more preferably an alkylene glycol having 2 to 6 carbon atoms, an AO adduct of bisphenol A (average number of moles added is preferably 2 to 5), and a trihydric aliphatic polyhydric alcohol having 3 to 36 carbon atoms, and particularly preferably ethylene glycol, propylene glycol, neopentyl glycol, an AO adduct of bisphenol A (average number of moles added is preferably 2 to 3), and trimethylolpropane.

As the saturated alcohol component (x), from the viewpoint of charge rise property, preferred are AO adducts of bisphenols (average number of moles added is preferably 2 to 5), AO adducts of trihydric to octahydric aliphatic polyhydric alcohols and novolak resins (including phenol novolak and cresol novolak, etc., with an average degree of polymerization preferably of 3 to 60) (average number of moles added is preferably 2 to 30), more preferred are AO adducts of bisphenol A (average number of moles added is 2 to 5), and even more preferred are AO adducts of bisphenol A (average number of moles added is 2 to 3).

As the saturated alcohol component (x), a saturated diol (x2) and a trihydric or higher saturated polyol (x3) can be used in combination. When used in combination, the molar ratio [(x2)/(x3)] of the saturated diol (x2) and the trihydric or higher saturated polyol (x3) is preferably 99/1 to 80/20, more preferably 98/2 to 90/10, from the viewpoint of hot offset resistance.

Examples of the unsaturated carboxylic acid component (y) include unsaturated monocarboxylic acids (y1), unsaturated dicarboxylic acids (y2), trivalent or higher unsaturated polycarboxylic acids (y3), and anhydrides and lower alkyl esters of these acids. These may be used alone or in combination of two or more.

The unsaturated monocarboxylic acid (y1) includes unsaturated monocarboxylic acids having 3 to 30 carbon atoms, such as acrylic acid, methacrylic acid, propiolic acid, 2-butenoic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, angelic acid, tiglic acid, 4-pentenoic acid, 2-ethyl-2-butenoic acid, 10-undecenoic acid, 2,4-hexadienoic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, erucic acid, and nervonic acid.

The unsaturated dicarboxylic acid (y2) includes alkene dicarboxylic acids having 4 to 50 carbon atoms, such as alkenylsuccinic acids such as dodecenylsuccinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and glutaconic acid.

Examples of the trivalent or higher unsaturated polycarboxylic acid (y3) include trivalent or higher alkene polycarboxylic acids having 6 to 50 carbon atoms (specifically, alkene tricarboxylic acids such as aconitic acid, 3-butene-1,2,3-tricarboxylic acid, and 4-pentene-1,2,4-tricarboxylic acid; alkene tetracarboxylic acids such as 1-pentene-1,1,4,4-tetracarboxylic acid, 4-pentene-1,2,3,4-tetracarboxylic acid, and 3-hexene-1,1,6,6-tetracarboxylic acid).

Among these unsaturated carboxylic acid components (y), from the viewpoint of achieving both low-temperature fixability and hot offset resistance, preferred are unsaturated monocarboxylic acids having 3 to 10 carbon atoms and alkene dicarboxylic acids having 4 to 18 carbon atoms, more preferred are acrylic acid, methacrylic acid, alkenylsuccinic acids such as dodecenylsuccinic acid, maleic acid and fumaric acid, and even more preferred are acrylic acid, methacrylic acid, maleic acid, fumaric acid and combinations of these. Similarly, anhydrides and lower alkyl esters of these acids are also preferred.

Examples of the saturated carboxylic acid component (w) include aromatic carboxylic acids and aliphatic carboxylic acids. The saturated carboxylic acid component (w) may be used alone or in combination of two or more.

Examples of aromatic carboxylic acids include aromatic monocarboxylic acids having 7 to 37 carbon atoms (benzoic acid, toluic acid, 4-ethylbenzoic acid, 4-propylbenzoic acid, etc.), aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.), and aromatic polycarboxylic acids having 9 to 20 carbon atoms and having a valence of 3 or more (trimellitic acid, pyromellitic acid, etc.).
Examples of aliphatic carboxylic acids include aliphatic 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.), aliphatic dicarboxylic acids having 2 to 50 carbon atoms (oxalic acid, malonic acid, succinic acid, adipic acid, oleaginic acid, sebacic acid, etc.), and aliphatic tricarboxylic acids having 6 to 36 carbon atoms (hexanetricarboxylic acid, etc.).
As the saturated carboxylic acid component (w), anhydrides and lower alkyl (having 1 to 4 carbon atoms) esters (methyl ester, ethyl ester, isopropyl ester, etc.) of these carboxylic acids may be used, or may be used in combination with these carboxylic acids.

Among these saturated carboxylic acid components (w), from the viewpoint of achieving both low-temperature fixability, hot offset resistance, and heat-resistant storage stability, preferred are aromatic monocarboxylic acids having 7 to 37 carbon atoms, aliphatic monocarboxylic acids having 2 to 50 carbon atoms, aliphatic dicarboxylic acids having 2 to 50 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and aromatic polycarboxylic acids having 3 or more valences having 9 to 20 carbon atoms. From the viewpoint of heat-resistant storage stability and charge rise property, more preferred are benzoic acid, behenic acid, adipic acid, alkyl succinic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, and combinations thereof, and even more preferred are adipic acid, behenic acid, terephthalic acid, trimellitic acid, and combinations thereof. In addition, anhydrides or lower alkyl esters of these acids may be used.

The method for producing the polyester (A11) of the present invention is not particularly limited, but a method of polycondensing components containing one or more types of unsaturated carboxylic acid components (y) and/or unsaturated alcohol components (z) as described above is preferred.

The polyester (A11) having a carbon-carbon double bond in the present invention is not particularly limited, but is preferably a nonlinear polyester from the viewpoint of improving elasticity at high temperatures. When the polyester (A11) is a nonlinear polyester, the heat resistance storage property and hot offset resistance are improved. The nonlinear polyester can be obtained, for example, by using a saturated diol (x2) and a trivalent or higher saturated polyol (x3) in the above ratio as the saturated alcohol component (x).

In the present invention, the polyester (A1) including the polyester (A11) can be produced in the same manner as in the production of known polyesters.
For example, the reaction can be carried out by reacting the constituent components 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 if 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 their intramolecular polycondensates, 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.

In addition, a stabilizer may be added to obtain polyester polymerization stability. Examples of stabilizers include hydroquinone, methylhydroquinone, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-isopropylphenol, 2,4,6-tri-tert-butylphenol, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, and the like. Examples of the phenol include 2,6-di-tert-butyl-4-methoxyphenol and hindered phenol compounds, and from the viewpoint of low-temperature fixing properties, preferred are 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-isopropylphenol, 2,4,6-tri-tert-butylphenol, tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone.

When producing polyester (A1), the total charge ratio of saturated alcohol component (x) and unsaturated alcohol component (z) to unsaturated carboxylic acid component (y) and saturated carboxylic acid component (w) is, in terms of the molar ratio of hydroxyl groups to carboxyl groups ([OH]/[COOH]), preferably 1/2 to 2/1, more preferably 1/1.3 to 1.5/1, and even more preferably 1/1.2 to 1.4/1. When polyester (A1) is polyester (A11), it is sufficient that it contains either one or both of unsaturated carboxylic acid component (y) and unsaturated alcohol component (z).

In the present invention, the glass transition temperature (Tg _A1 ) of the polyester (A1) is preferably from -35 to 49°C.
When Tg _A1 is 49° C. or lower, low-temperature fixability is good, and when it is −35° C. or higher, heat-resistant storage stability is good. The glass transition temperature (Tg _A1 ) of the polyester (A1) is more preferably −30 to 42° C., further preferably −25 to 40° C., and particularly preferably −25 to 37° C.
The glass transition temperature (Tg) can be measured, for example, by using a DSC Q20 manufactured by TA Instruments Co., Ltd., according to the method (DSC method) specified in ASTM D3418-82.

In the present invention, the peak top molecular weight Mp of the polyester (A1) in gel permeation chromatography (GPC) is preferably from 2,000 to 30,000, more preferably from 3,000 to 20,000, and even more preferably from 4,000 to 15,000.
When the peak top molecular weight Mp of the polyester (A1) is from 2,000 to 30,000, the gloss, low-temperature fixability and hot offset resistance become favorable.

Here, a method for calculating the peak top molecular weight Mp will be described.
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 a resin such as a polyester can be measured using GPC under the following conditions.
Equipment (example): HLC-8120 [manufactured by Tosoh Corporation]
Column (example): 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) manufactured by Tosoh Corporation (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000)
For the measurement of molecular weight, a sample is dissolved in 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.

The acid value of the polyester (A1) is preferably 0 to 30 mgKOH/g, more preferably 0 to 25 mgKOH/g, even more preferably 0 to 10 mgKOH/g, and particularly preferably 0.1 to 10 mgKOH/g, from the viewpoints of charge rise and heat-resistant storage stability. The hydroxyl value of the polyester (A1) is preferably 5 to 30 mgKOH/g, more preferably 10 to 25 mgKOH/g, and even more preferably 15 to 25 mgKOH/g, from the viewpoints of charge rise and heat-resistant storage stability.
The acid value and hydroxyl value of the polyester (A1) can be measured by the method specified in JIS K0070 (1992 edition).

When the polyester (A1) is a polyester (A11) having a carbon-carbon double bond, the content of the carbon-carbon double bond in the polyester (A11) is not particularly limited, but is preferably 0.02 to 2.0 mmol/g, more preferably 0.06 to 1.9 mmol/g, still more preferably 0.10 to 1.5 mmol/g, and particularly preferably 0.15 to 1.0 mmol/g, based on the weight of the polyester (A11).
When the content of the carbon-carbon double bond is 0.02 to 2.0 mmol/g based on the weight of the polyester (A11), the crosslinking reaction occurs favorably, and the toner has good hot offset resistance.

The method for measuring the content of carbon-carbon double bonds in polyester (A11) is not particularly limited, and can be measured by ¹ H-NMR, ¹³ C-NMR, bromine number test method (JIS K2605), etc. The content of carbon-carbon double bonds in the examples was measured by the following method.
<Sample Preparation>
In a ¹³ C-NMR tube, 100 mg of sample, 10 mg of sodium trimethylsilylpropanesulfonate as an internal standard substance, and 10 mg of Cr(AcAc) ₃ as a relaxation reagent are weighed out, and 0.45 ml of a deuterated solvent (deuterated pyridine) is added to dissolve the resin.
<Measurement conditions>
Apparatus: Bruker Biospin "AVANCE III HD400"
Number of times of accumulation: 24,000 times <Analysis and calculation>
For example, when the carbon-carbon double bond is an unsaturated carboxylic acid component (z) such as maleic acid or fumaric acid, the double bond content (mmol/g) is calculated from the area ratio of the carbon peak (164.6 ppm) of the double bond derived from the unsaturated carboxylic acid component (z) to the area ratio of the carbon peak (0 ppm) of the internal standard substance.

As a method for producing the polyester resin (A), the following method can be mentioned as a preferred method.
First, at least one of the unsaturated carboxylic acid component (y) and the unsaturated alcohol component (z) is condensed with a saturated carboxylic acid component (w) and/or a saturated alcohol component (x) as necessary to obtain a polyester (A11) having a carbon-carbon double bond in the molecule. Next, a radical reaction initiator (d) is reacted with the polyester (A11), and the carbon-carbon double bonds originating from the unsaturated carboxylic acid component (y) and/or the unsaturated alcohol component (z) in the polyester (A11) are crosslinked with the radicals generated from the radical reaction initiator (d). This allows the polyester resin (A) to be produced. This method is preferred because it allows the crosslinking reaction to occur uniformly in a short time.

The radical reaction initiator (d) used for the crosslinking reaction of polyester (A11) is not particularly limited, and examples thereof include inorganic peroxides (d1), organic peroxides (d2), and azo compounds (d3). These radical reaction initiators may also be used in combination.

The inorganic peroxide (d1) is not particularly limited, but examples thereof include hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

The organic peroxide (d2) 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 (d3) is not particularly limited, but examples thereof include 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

Among these, the organic peroxides (d2) are preferred because they have high initiator efficiency and do not produce by-products such as cyanide compounds.
Furthermore, a reaction initiator having a high hydrogen abstraction ability is more preferred because the crosslinking reaction proceeds efficiently and a small amount can be used, and a radical reaction initiator having a high hydrogen abstraction ability, such as benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, t-butylperoxy-2-ethylhexanoate, dicumyl peroxide, α,α-bis(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and di-t-hexyl peroxide, is even more preferred.

The amount of the radical reaction initiator (d) used is not particularly limited, but is preferably 0.1 to 50% by weight based on the total weight of the unsaturated carboxylic acid component (y) and the unsaturated alcohol component (z) used in the polymerization reaction to obtain the polyester (A11).
When the amount of the radical reaction initiator used is 0.1% by weight or more, the crosslinking reaction tends to proceed easily, and when it is 50% by weight or less, the odor tends to be good. The amount used is more preferably 30% by weight or less, even more preferably 20% by weight or less, and particularly preferably 10% by weight or less.

When radical polymerization is carried out using the above-mentioned type of radical reaction initiator (d) in the above-mentioned amount, a crosslinking reaction between the carbon-carbon double bonds in the polyester (A11) occurs favorably, which is preferable because it improves the heat-resistant storage stability and hot offset resistance of the toner.

The toner binder of the present invention contains a crystalline vinyl resin (B) as an essential component. The crystalline vinyl resin (B) may be used alone or in combination of two or more kinds.
In the present invention, "crystalline" means that in differential scanning calorimetry (also referred to as DSC measurement) described below, the DSC curve has a peak top temperature of an endothermic peak.

The method for measuring the peak top temperature (Tm _B ) of the endothermic peak of the crystalline vinyl resin (B) will be described.
The measurement is performed using a differential scanning calorimeter (e.g., "DSCQ20" [manufactured by TA Instruments, Inc.]). The crystalline vinyl resin (B) is heated for the first time from 20°C to 150°C at 10°C/min, then cooled from 150°C to 0°C at 10°C/min, and then heated for the second time from 0°C to 150°C at 10°C/min. The temperature showing the top of the endothermic peak during the second heating process is defined as the peak top temperature (TmB) of the endothermic peak of the crystalline vinyl resin ( _B ).

The crystalline vinyl resin (B) in the present invention is a polymer containing a monomer (a) as an essential constituent monomer, and the monomer (a) is a (meth)acrylate having a chain hydrocarbon group and 21 to 40 carbon atoms. The number of carbon atoms in the monomer (a) is the sum of the number of carbon atoms in the chain hydrocarbon group and the number of carbon atoms (3 or 4) constituting the (meth)acrylic acid ester. The (meth)acrylate (a) having a chain hydrocarbon group and 21 to 40 carbon atoms may be used alone or in combination of two or more kinds.
In this specification, (meth)acrylate means acrylate and/or methacrylate.

Examples of (a) include (meth)acrylates having a linear alkyl group (having 18 to 36 carbon atoms) [octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, seryl (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].
Among these, from the viewpoint of achieving a balance between the heat-resistant storage stability, low-temperature fixing property, and hot offset resistance of the toner, preferred are (meth)acrylates 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), still more preferred are octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, seryl (meth)acrylate, and triacontyl (meth)acrylate, and particularly preferred are octadecyl acrylate, eicosyl acrylate, behenyl acrylate, and lignoceryl acrylate.

In view of the hot offset resistance and heat-resistant storage stability of the toner, the vinyl resin (B) may contain, as a constituent monomer, the monomer (b) in addition to the monomer (a) described above. The monomer (b) may be used alone or in combination of two or more kinds.

Examples of the monomer (b) include styrene-based monomers (b1), (meth)acrylic monomers other than monomer (a) (b2), vinyl ester monomers (b3), and monomers (b4) having at least one functional group selected from the group consisting of a nitrile group, a urethane group, a urea group, an amide group, an imide group, an allophanate group, and a biuret group, and an ethylenically unsaturated bond.

Examples of the styrene-based monomer (b1) include styrene and alkylstyrenes having an alkyl group with 1 to 3 carbon atoms (eg, α-methylstyrene and p-methylstyrene).
Of these, styrene is preferred.

Examples of the (meth)acrylic monomer (b2) include (meth)acrylic acid, 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 4 to 20 carbon atoms [2-hydroxypropyl acrylate, 2-hydroxyethyl (meth)acrylate, ethyl-2-(hydroxymethyl)acrylate, etc.], and hydroxyalkyl (meth)acrylates having 4 to 20 carbon atoms [2-hydroxypropyl acrylate, 2-hydroxyethyl (meth)acrylate, ethyl-2-(hydroxymethyl)acrylate, etc.]. to 20 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.], and the like.
Of these, preferred are methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, and mixtures of two or more of these.
In this specification, (meth)acrylic acid means acrylic acid and/or methacrylic acid.

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

Examples of the monomer (b4) having at least one functional group selected from the group consisting of a nitrile group, a urethane group, a urea group, an amide group, an imide group, an allophanate group, and a biuret group and an ethylenically unsaturated bond include a monomer (b41) having a nitrile group and a carbon number of 6 or less [(meth)acrylonitrile, etc.], a monomer (b42) having a urethane group [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, etc.], a monomer (b43) having a urea group, a monomer (b44) having an amide group, a monomer (b45) having an imide group, a monomer (b46) having an allophanate group, and a monomer (b47) having a biuret group.
As used herein, the term "(meth)acrylonitrile" means "acrylonitrile" and/or "methacrylonitrile".
Among these monomers (b4), preferred are monomers (b41) having a nitrile group and having 6 or less carbon atoms.

Vinyl resin (B) may contain other monomers as constituent monomers in addition to the above-mentioned monomers (a) and (b), such as divinylbenzene and sodium alkylarylsulfosuccinate.

From the viewpoint of crystallinity, the weight ratio of the monomer (a) in the monomers constituting the crystalline vinyl resin (B) is preferably 15 to 93% by weight based on the weight of the crystalline vinyl resin (B). If it is 15% by weight or more, the low-temperature fixing property is good, and if it is 93% by weight or less, the hot offset resistance is good. Furthermore, from the viewpoint of achieving both low-temperature fixing property, hot offset resistance, and heat-resistant storage stability, it is preferably 20 to 90% by weight, and more preferably 45 to 80% by weight.

From the viewpoint of heat resistance storage property and hot offset resistance, the weight ratio of the monomer (b) in the monomers constituting the crystalline vinyl resin (B) is preferably 7 to 85% by weight, more preferably 10 to 80% by weight, and even more preferably 20 to 55% by weight, based on the weight of the crystalline vinyl resin (B).

From the viewpoints of achieving both heat-resistant storage stability and low-temperature fixability, and of glossiness, the peak top temperature (Tm _B ) of the endothermic peak of the crystalline vinyl resin (B) is preferably 40 to 100° C. When _{Tm B} is 40° C. or higher, the heat-resistant storage stability is good, and when it is 100° C. or lower, the low-temperature fixability and glossiness are good.
The peak top temperature (Tm _B ) of the endothermic peak of the crystalline vinyl resin (B) is more preferably 45 to 95°C, further preferably 50 to 90°C, and particularly preferably 52 to 88°C.
The peak top temperature (Tm _B ) of the endothermic peak of the crystalline vinyl resin (B) can be adjusted by the types and composition ratios of the monomers constituting the crystalline vinyl resin (B), the weight average molecular weight, etc.

The half-width of the endothermic peak indicating the peak top temperature (Tm _B ) of the endothermic peak of the crystalline vinyl resin (B) is preferably 6° C. or less, more preferably 3° C. or less, from the viewpoints of low-temperature fixability and heat-resistant storage stability.
The half-width of the endothermic peak indicating the peak top temperature (Tm _B ) of the crystalline vinyl resin (B) refers to the temperature width of the peak at half the height from the baseline of the endothermic peak to the maximum height of the peak, based on a DSC curve obtained by measuring the peak top temperature of the endothermic peak.

From the viewpoint of heat-resistant storage stability and charge build-up property, the hydroxyl value of the crystalline vinyl resin (B) is preferably 40 mgKOH/g or less, and more preferably 0 to 24 mgKOH/g.
In addition, when the hydroxyl value is 5 mgKOH/g or more, low-temperature fixing property is good. From the viewpoint of low-temperature fixing property, the hydroxyl value of the crystalline vinyl resin (B) is more preferably 7 mgKOH/g or more, further preferably 10 mgKOH/g or more, and particularly preferably 15 to 35 mgKOH/g.
The hydroxyl value of the crystalline vinyl resin (B) can be adjusted by the hydroxyl value of the monomer and the content of the monomer having a hydroxyl value. The hydroxyl value of (B) can be measured, for example, by a method such as JIS K0070.

The Mn of the crystalline vinyl resin (B) in gel permeation chromatography (GPC) is preferably 1,000 to 300,000 from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability of the toner.

The Mw of the crystalline vinyl resin (B) as determined by gel permeation chromatography (GPC) is preferably from 1,000 to 300,000 from the viewpoints of hot offset resistance, heat-resistant storage stability and low-temperature fixability of the toner.
The Mn and Mw of the crystalline vinyl resin (B) can be measured in the same manner as for the polyester resin.

The crystalline vinyl resin (B) in the present invention can be produced by polymerizing a monomer composition containing a (meth)acrylate (a) having a chain hydrocarbon group and 21 to 40 carbon atoms and a monomer (b) used as needed, by a known method (e.g., radical polymerization, anionic polymerization, cationic polymerization, living radical polymerization, living anionic polymerization, living cationic polymerization, etc.). For example, it can be produced by a solution polymerization method (JP Patent Publication No. 5-117330, etc.) in which the above monomer is reacted with a radical reaction initiator (d) in a solvent (toluene, etc.).

The radical reaction initiator may be the radical reaction initiator (d) described above. The preferred radical reaction initiator (d) is also the same as described above.
The toner binder obtained by the method of the present invention may contain the compound used in the polymerization of the above-mentioned crystalline vinyl resin (B) and its residue, within the range not impairing the effects of the present invention.

The toner binder of the present invention contains a polyethylene glycol fatty acid ester (C) as an essential component. The polyethylene glycol fatty acid ester (C) may be used alone or in combination of two or more kinds. Examples of the polyethylene glycol fatty acid ester (C) include esters composed of fatty acids and polyethylene glycol, and ethylene oxide adducts of fatty acids, and from the viewpoint of gloss, ethylene oxide adducts of fatty acids are preferred.

Fatty acids include saturated fatty acids (c1) and unsaturated fatty acids (c2). One type of fatty acid may be used alone, or two or more types may be used in combination to form a mixed fatty acid of saturated fatty acids (c1) and unsaturated fatty acids (c2).

Examples of saturated fatty acids (c1) include saturated fatty acids having 4 to 50 carbon atoms (such as butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and melissic acid). Among the above, from the viewpoint of heat resistance and storage stability, saturated fatty acids having 14 to 18 carbon atoms (such as myristic acid, palmitic acid, and stearic acid) are preferred.

Examples of unsaturated fatty acids (c2) include unsaturated fatty acids having 4 to 50 carbon atoms (methacrylic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, mead acid, etc.). Among the above, from the viewpoint of heat resistance and storage stability, saturated fatty acids having 14 to 18 carbon atoms (palmitoleic acid, oleic acid, linoleic acid, linolenic acid, etc.) are preferred.

In the ester composed of fatty acid and polyethylene glycol, examples of the polyethylene glycol include polyethylene glycols having a number average molecular weight of 100 to 10,000 (diethylene glycol, triethylene glycol, tetraethylene glycol, and ethylene oxide adducts of the above glycols, etc.). Among the above, polyethylene glycols having a number average molecular weight of 100 to 2,000 are preferred from the viewpoint of heat resistance storage stability.

In the ethylene oxide adduct of a fatty acid, the average number of moles of ethylene oxide added that constitutes the ethylene oxide adduct of a fatty acid is not particularly limited, but from the viewpoints of heat-resistant storage stability and gloss, it is preferably 5 to 25, more preferably 5 to 20, and even more preferably 5 to 15.

From the viewpoint of heat-resistant storage stability, the polyethylene glycol fatty acid ester (C) in the present invention is preferably an ethylene oxide adduct of a mixed fatty acid containing a saturated fatty acid (c1) having 14 to 18 carbon atoms and an unsaturated fatty acid (c2) having 14 to 18 carbon atoms.

The toner binder of the present invention may contain other resins (such as the polymers described in JP-A-06-194876) that are known as resins for toner binders other than the polyester resin (A), the crystalline vinyl resin (B), and the polyethylene glycol fatty acid ester (C). The other resins may be one type of resin or a mixture of two or more types of resins.

In the present invention, the content of polyester resin (A) is preferably 27 to 60% by weight, more preferably 28 to 60% by weight, based on the weight of the toner binder, from the viewpoint of hot offset resistance.

In the present invention, the content of the crystalline vinyl resin (B) is preferably 37 to 70% by weight, more preferably 38 to 70% by weight, based on the weight of the toner binder, from the viewpoints of low-temperature fixing ability and hot offset resistance.

In the present invention, the content of the polyethylene glycol fatty acid ester (C) is preferably 0.02 to 3.00% by weight, more preferably 0.06 to 2.00% by weight, based on the weight of the toner binder, from the viewpoints of charge build-up property, glossiness, and heat-resistant storage stability.

In the toner binder of the present invention, from the viewpoints of charge build-up property, glossiness, and heat-resistant storage stability, the weight ratio [(B)/(C)] of the crystalline vinyl resin (B) to the polyethylene glycol fatty acid ester (C) is preferably 20 to 1,000, and more preferably 30 to 600.

In the toner binder of the present invention, the polyester resin (A) is dispersed as particles in the toner binder, and the number average particle diameter of the polyester resin (A) in the toner binder is 0.1 to 7.5 μm. By satisfying these ranges, the charge rise property and glossiness are improved. Furthermore, from the viewpoint of the charge rise property and glossiness, it is preferable that the number average particle diameter of the polyester resin (A) in the toner binder is 0.1 to 5.0 μm.
The number average particle diameter of the polyester resin (A) in the toner binder can be measured by observing the cross section of the toner binder or toner with a transmission electron microscope (TEM). The number average particle diameter of the polyester resin (A) in the toner binder can be adjusted by the weight ratio of the polyester (A) to the crystalline vinyl resin (B), the composition ratio of the polyester resin (A) to the crystalline vinyl resin (B), the weight of the polyethylene glycol fatty acid ester (C) in the toner binder, the weight ratio of the crystalline vinyl resin (B) to the polyethylene glycol fatty acid ester (C), the number of moles added of the polyethylene glycol fatty acid ester (C), and when the polyester (A1) is polymerized in the presence of the crystalline vinyl resin (B), the polymerization conditions of the polyester (A1) in the presence of the crystalline vinyl resin (B) and the constituent components of the polyester (A1).
For example, the number average particle diameter of the polyester resin (A) in the toner binder can be reduced by increasing the weight of the polyethylene glycol fatty acid ester (C) in the toner binder, increasing the weight ratio of the crystalline vinyl resin (B) to the polyethylene glycol fatty acid ester (C), or using an aliphatic monocarboxylic acid having 2 to 50 carbon atoms or a linear or branched alkyl alcohol having 1 to 30 carbon atoms as a constituent of the polyester (A1). Also, the number average particle diameter of the polyester resin (A) in the toner binder can be increased by increasing the number of moles added of the polyethylene glycol fatty acid ester (C).

The glass transition temperature (Tg) of the toner binder of the present invention is preferably from 25 to 80°C, more preferably from 30 to 65°C, from the viewpoints of low-temperature fixability and heat-resistant storage stability.
When the Tg is 80° C. or lower, the low-temperature fixability is good, and when it is 25° C. or higher, the heat-resistant storage stability is good.
The glass transition temperature (Tg) of the toner binder can be measured, like the glass transition temperature of the polyester (A1), by the method (DSC method) specified in ASTM D3418-82 using, for example, DSCQ20 manufactured by TA Instruments.

The toner binder of the present invention preferably has at least one endothermic peak top temperature (Tm) in the range of 40 to 100°C.
The peak top temperature (Tm) of the endothermic peak of the toner binder can be measured in the same manner as the peak top temperature (Tm _B ) of the endothermic peak of the crystalline vinyl resin (B).

The endothermic peak peak top temperature (Tm) is preferably the endothermic peak peak top temperature derived from the crystalline vinyl resin (B). In one embodiment, the toner binder of the present invention has an endothermic peak top temperature derived from the crystalline vinyl resin (B) of preferably 43 to 95°C, more preferably 45 to 90°C, even more preferably 50 to 90°C, and particularly preferably 51 to 88°C. When the endothermic peak peak top temperature (Tm) derived from the crystalline vinyl resin (B) is in the above range, the balance between the low-temperature fixability and the heat-resistant storage stability of the toner binder is improved. This is because the crystalline vinyl resin (B) becomes sharply melted at the temperature showing (Tm) when the toner using the toner binder is thermally fixed, and the viscosity of the toner binder is reduced, and also because the crystalline vinyl resin (B) melts to prevent the fusion of toner particles with each other when the toner is stored, thereby satisfying storage stability.

The hydroxyl value of the toner binder of the present invention is preferably 3 mgKOH/g or more from the viewpoint of separability from the fixing roller. When the hydroxyl value is 3 mgKOH/g or more, the separability from the fixing roller becomes good. The hydroxyl value of the toner binder is more preferably 7 mgKOH/g or more, and further preferably 10 to 30 mgKOH/g. The hydroxyl value of the toner binder may be 0 mgKOH/g.
The hydroxyl value of the toner binder can be adjusted by the hydroxyl value of the polyester (A1) and the hydroxyl value of the monomer constituting the crystalline vinyl resin (B) or the content of the monomer having a hydroxyl value. The hydroxyl value of the toner binder is measured by a method such as JIS K 0070.

The weight average molecular weight (Mw) of the toner binder of the present invention is preferably from 5,000 to 200,000, more preferably from 10,000 to 180,000, further preferably from 50,000 to 180,000, and particularly preferably from 50,000 to 70,000, from the viewpoint of achieving both hot offset resistance and low-temperature fixability of the toner.
The weight average molecular weight of the toner binder can be measured under the same conditions as those for the polyester (A1).

A method for producing the toner binder will now be described.
The toner binder is not particularly limited as long as it contains polyester resin (A), crystalline vinyl resin (B) and polyethylene glycol fatty acid ester (C), and for example, the mixing method for mixing the polyester resin (A), crystalline vinyl resin (B) and polyethylene glycol fatty acid ester (C) and additives may be a commonly used known method, and examples of the mixing method include powder mixing, melt mixing and solvent mixing. In addition, the polyester resin (A), crystalline vinyl resin (B), polyethylene glycol fatty acid ester (C) and additives used as necessary may be mixed at the same time when the toner is produced. Among these methods, melt mixing is preferred, which allows uniform mixing and does not require solvent removal.

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 twin-screw extruders, twin-screw kneaders, static mixers, extruders, continuous kneaders, and three-roll mills.

Methods for solvent mixing include dissolving the polyester resin (A), crystalline vinyl resin (B) and polyethylene glycol fatty acid ester (C) in a solvent (ethyl acetate, THF, acetone, etc.), homogenizing, and then removing the solvent and pulverizing; dissolving the polyester resin (A), crystalline vinyl resin (B) and polyethylene glycol fatty acid ester (C) in a solvent (ethyl acetate, THF, acetone, etc.), dispersing in water, granulating, and removing the solvent; and crosslinking the polyester (A11) while melt-mixing the crystalline vinyl resin (B), polyethylene glycol fatty acid ester (C) and polyester (A11).

Among them, a method of crosslinking polyester (A11) while melt-mixing crystalline vinyl resin (B), polyethylene glycol fatty acid ester (C), and polyester (A11) is preferred, and a specific method for performing this melt-mixing is to inject a mixture of polyester (A11), (B), and (C) into a continuous mixer at a constant speed, simultaneously inject radical reaction initiator (d) at a constant speed, and react while kneading and conveying at a temperature of 100 to 200°C. In addition, the melt-mixing method is not limited to these specific exemplified methods, and it can be performed by any appropriate method, such as, for example, charging the raw materials into a reaction vessel, heating them to a temperature at which they become a solution, and mixing them.

The toner containing the toner binder of the present invention may contain colorants, release agents, charge control agents, and flow agents, etc., 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, nickel, etc., 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 of the present invention. When a magnetic powder is used as the colorant, the content is preferably 20 to 150 parts by weight, more preferably 40 to 120 parts by weight.

The release agent preferably has a flow softening point [T1 _/2 ] of 50 to 170°C as measured by a constant test force extrusion type capillary rheometer flow tester. Examples of the release agent include aliphatic hydrocarbon waxes such as polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, as well as oxides thereof, carnauba wax, montan wax, and deacidified waxes thereof, ester wax, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, and mixtures thereof.

The method for measuring the flow softening point [T _1/2 ] will be described.
Using a constant test force 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 the plunger and extruding it from a nozzle of 1 mm diameter and 1 mm length. A graph of "plunger depression amount (flow value)" vs. "temperature" is plotted, and the temperature corresponding to 1/2 of the maximum value of the plunger depression amount is taken as the flow softening point [T _1/2 ].

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 and FT-0070 manufactured by Nippon Seiro Co., Ltd.

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 the fluidizing agent 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, the silica is preferably hydrophobic silica. From the viewpoint of the transferability of the toner, the silica is preferably hydrophobic silica.

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 even more preferably 0.1 to 4% by weight, based on the weight of the toner.
The total content of additives (colorants, releasing agents, charge control agents, fluidizing agents, etc.) 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 toner weight.

The method for producing the toner containing the toner binder of the present invention is not particularly limited, and the toner may be obtained by any known method such as a kneading and pulverizing method, an emulsion phase inversion method, an emulsion polymerization method, a suspension polymerization method, a dissolution suspension method, or an emulsion aggregation 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 using a Henschel mixer, a Nauter mixer, a Banbury mixer, or the like, and then melt-kneaded using a continuous mixer such as a twin-screw kneader, an extruder, a continuous kneader, or a three-roll mill, and then coarsely pulverized using a mill or the like, and finally micronized using an air flow type micropulverizer or the like, and further the particle size distribution is adjusted using a classifier such as an elbow jet to form toner particles [preferably particles having a volume average particle size (D50) of 5 to 20 μm], and then the fluidizing agent can be mixed therein to produce the toner.

The volume average particle size (D50) of the toner particles (toner) can be measured using a Coulter counter [for example, trade name: Multisizer III (manufactured by Beckman Coulter, Inc.)].
Specifically, 0.1 to 5 mL of a surfactant (alkylbenzene sulfonate) is added as a dispersant to 100 to 150 mL of an electrolyte solution of ISOTON-II (manufactured by Beckman Coulter, Inc.). 2 to 20 mg of a measurement sample is then added, and the electrolyte solution in which the sample is suspended is subjected to a dispersion process for about 1 to 3 minutes using an ultrasonic disperser. The volume and number of toner particles are measured using a 50 μm aperture with the measurement device, and the volume distribution and number distribution are calculated. From the distribution obtained, the volume average particle diameter (D50) (μm), number average particle diameter (μm), and particle size distribution (volume average particle diameter/number average particle diameter) of the toner particles are obtained.

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 containing the toner binder of the present invention is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite coated with a 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 containing the toner binder of the present invention may not contain carrier particles.

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

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

The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited thereto. In the following, "parts" refers to parts by weight unless otherwise specified.
In addition, the molar ratio (parts by mole) of ethylene oxide in Production Examples 6 to 10 is a molar ratio (parts by mole) when the amount of acid is 1 mole (1 part by mole).

<Production Example 1> [Production of Polyester (A1-1)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 730 parts of bisphenol A·EO 2 mole adduct as the saturated alcohol component (x), 12 parts of trimethylolpropane, 151 parts of terephthalic acid as the saturated carboxylic acid component (w) and 162 parts of adipic acid, and 2.5 parts of titanium diisopropoxybis(triethanolamine) as a 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 then the temperature was lowered to 180°C. 1 part of 2,6-di-tert-butyl-4-methylphenol was placed as a polymerization inhibitor, and 20 parts of fumaric acid as the unsaturated carboxylic acid component (y) was placed, and the reaction was carried out for 8 hours under a reduced pressure of 0.5 to 2.5 kPa, followed by removal to obtain polyester (A1-1).
The polyester (A1-1) had a glass transition temperature of 37° C., a peak top molecular weight of 13,700, an acid value of 1 mgKOH/g, a hydroxyl value of 15 mgKOH/g, and an amount of double bonds of 0.2 mmol/g, all of which were measured by the above-mentioned methods.

<Production Example 2> [Production of Polyester (A1-2)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 334 parts of propylene glycol and 251 parts of neopentyl glycol as the saturated alcohol component (x), 633 parts of terephthalic acid and 31 parts of behenic acid as the saturated carboxylic acid component (w), and 2.5 parts of titanium diisopropoxybis(triethanolamine) as a catalyst were placed, and pressurized esterification was carried out at 227°C and 0.45 MPa for 5 hours, and it was confirmed that the acid value was 10 mgKOH/g. Thereafter, reduced pressure esterification was carried out at 2.5 kPa or less, 162 parts of propylene glycol was recovered, and the temperature was lowered to 180°C. 1 part of 2,6-di-tert-butyl-4-methylphenol was placed as a polymerization inhibitor, and 68 parts of fumaric acid as the unsaturated carboxylic acid component (y) was placed, and the mixture was reacted under a reduced pressure of 0.5 to 2.5 kPa for 8 hours, and then removed to obtain polyester (A1-2).
The polyester (A1-2) had a glass transition temperature of 49° C., a peak top molecular weight of 7,500, an acid value of 2 mg KOH/g, a hydroxyl value of 25 mg KOH/g, and a double bond amount of 0.5 mmol/g, all of which were measured by the above-mentioned methods.

The compositions and physical properties of polyesters (A1-1) and (A1-2) are shown in Table 1.

<Production Example 3> [Production of Crystalline Vinyl Resin (B-1)]
An autoclave was charged with 113 parts of xylene, and the air was replaced with nitrogen, and the temperature was raised to 170° C. in a sealed state with stirring. A mixed solution of 450 parts of behenyl acrylate [abbreviated as C22 acrylate hereinafter, manufactured by NOF Corp., the same applies below], 75 parts of styrene [manufactured by Idemitsu Kosan Co., Ltd., the same applies below], 69 parts of methyl acrylate [manufactured by Toagosei Co., Ltd., the same applies below], 113 parts of acrylonitrile [manufactured by Nacalai Tesque Inc., the same applies below], 38 parts of 2-hydroxyethyl acrylate [manufactured by NOF Corp., the same applies below], 6 parts of 1,6-hexanediol acrylate [manufactured by Tokyo Chemical Industry Co., Ltd., the same applies below], 0.8 parts of di-t-butyl peroxide [Perbutyl D, manufactured by NOF Corp., the same applies below], and 130 parts of xylene was added dropwise over 3 hours while controlling the temperature inside the autoclave to 170° C., to carry out polymerization. After dripping, the drip line was washed with 8 parts of xylene. After further holding at the same temperature for 0.5 hours, the reaction rate of the monomer (a) was confirmed after cooling to 70°C. Since the reaction rate of the monomer (a) was less than 95%, the temperature was raised again to 170°C, and 1.6 parts of di-t-butyl peroxide were further added, and the reaction was continued until the reaction rate reached 95% or more. Thereafter, the solvent was removed at 170°C under reduced pressure of 0.5 to 2.5 kPa for 5 hours, to obtain a crystalline vinyl resin (B-1).
The crystalline vinyl resin (B-1) had an endothermic peak top temperature of 61° C., an endothermic peak half width of 2° C., a hydroxyl value of 24 mgKOH/g, and a weight average molecular weight of 65,000, as measured by the above-mentioned method.

<Production Example 4> [Production of Crystalline Vinyl Resin (B-2)]
138 parts of xylene was charged into the autoclave, and after replacing with nitrogen, the temperature was raised to 140 ° C. in a sealed state under stirring. A mixed solution of 675 parts of C22 acrylate, 38 parts of styrene, 19 parts of acrylonitrile, 19 parts of 2-hydroxyethyl acrylate, 0.8 parts of di-t-butyl peroxide, and 100 parts of xylene was dropped over 3 hours while controlling the temperature inside the autoclave to 140 ° C., and polymerization was carried out. After dropping, the dropping line was washed with 13 parts of xylene, and the temperature was held at the same temperature for 1 hour, and then the temperature was raised to 170 ° C. over 1 hour. After further holding at the same temperature for 0.5 hours, the reaction rate of the monomer (a) was confirmed after cooling to 70 ° C., since the reaction rate of the monomer (a) was less than 95%, the temperature was raised again to 170 ° C., and 1.6 parts of di-t-butyl peroxide was further added, and the reaction was carried out until the reaction rate was 95% or more. Thereafter, the solvent was removed at 170° C. under reduced pressure of 0.5 to 2.5 kPa for 5 hours to obtain a crystalline vinyl resin (B-2).
The crystalline vinyl resin (B-2) had an endothermic peak top temperature of 65° C., an endothermic peak half width of 2° C., a hydroxyl value of 12 mgKOH/g, and a weight average molecular weight of 50,000, as measured by the above method.

<Production Example 5> [Production of Crystalline Vinyl Resin (B-3)]
130 parts of C22 acrylate and 210 parts of xylene were charged into an autoclave, and the atmosphere was replaced with nitrogen. The temperature was raised to 170°C in a sealed state under stirring, and the temperature was controlled at 170°C for 2 hours. A mixed solution of 254 parts of styrene, 169 parts of methyl acrylate, 52 parts of acrylonitrile, 46 parts of 2-hydroxyethyl acrylate, 2.6 parts of di-t-butyl peroxide, and 123 parts of xylene was dropped over 2 hours while controlling the temperature inside the autoclave to 170°C, and polymerization was carried out. After dropping, the dropping line was washed with 18 parts of xylene. After further holding at the same temperature for 0.5 hours, the reaction rate of monomer (a) was confirmed after cooling to 70°C. Since the reaction rate of monomer (a) was 95% or more, the temperature was raised again to 170°C, and the solvent was removed under a reduced pressure of 0.5 to 2.5 kPa for 5 hours, to obtain a crystalline vinyl resin (B-3).
The crystalline vinyl resin (B-3) had an endothermic peak top temperature of 59° C., an endothermic peak half width of 3° C., a hydroxyl value of 34 mgKOH/g, and a weight average molecular weight of 45,000, as measured by the above-mentioned method.

The compositions and physical properties of crystalline vinyl resins (B-1) to (B-3) are shown in Table 2.

<Production Example 6> [Production of polyethylene glycol fatty acid ester (C-1)]
561 parts of TFA-120 [manufactured by Tsuno Foods Industries Co., Ltd., the same applies below], which is a mixed fatty acid containing (c1) and (c2), and 0.5 parts of potassium hydroxide were charged into an autoclave, and the inside of the mixed system was replaced with nitrogen, and then dehydration was performed at 120°C under reduced pressure (2.7 kPa) for 1 hour. Next, 438 parts (5 molar parts) of ethylene oxide were added dropwise at 150°C while adjusting the pressure to 0.01 to 0.03 MPa. Thereafter, the mixture was neutralized with 0.5 parts of acetic acid, and a polyethylene glycol fatty acid ester (C-1) was obtained by filtration.

<Production Example 7> [Production of polyethylene glycol fatty acid ester (C-2)]
416 parts of TFA-120 and 0.5 parts of potassium hydroxide were charged into an autoclave, and the inside of the mixed system was replaced with nitrogen, and then dehydration was carried out at 120° C. under reduced pressure (2.7 kPa) for 1 hour. Next, 583 parts (9 molar parts) of ethylene oxide were added dropwise at 150° C. while adjusting the pressure to 0.01 to 0.03 MPa. Thereafter, the mixture was neutralized with 0.5 parts of acetic acid, and a polyethylene glycol fatty acid ester (C-2) was obtained by filtration.

<Production Example 8> [Production of polyethylene glycol fatty acid ester (C-3)]
314 parts of TFA-120 and 0.5 parts of potassium hydroxide were charged into an autoclave, and the inside of the mixed system was replaced with nitrogen, and then dehydration was carried out at 120° C. under reduced pressure (2.7 kPa) for 1 hour. Then, 685 parts (14 molar parts) of ethylene oxide were added dropwise at 150° C. while adjusting the pressure to 0.01 to 0.03 MPa. Thereafter, the mixture was neutralized with 0.5 parts of acetic acid, and a polyethylene glycol fatty acid ester (C-3) was obtained by filtration.

<Production Example 9> [Production of polyethylene glycol fatty acid ester (C-4)]
243 parts of TFA-120 and 0.5 parts of potassium hydroxide were charged into an autoclave, and the inside of the mixed system was replaced with nitrogen, and then dehydration was carried out at 120° C. under reduced pressure (2.7 kPa) for 1 hour. Next, 756 parts (20 parts by mole) of ethylene oxide were added dropwise at 150° C. while adjusting the pressure to 0.01 to 0.03 MPa. Thereafter, the mixture was neutralized with 0.5 parts of acetic acid, and a polyethylene glycol fatty acid ester (C-4) was obtained by filtration.

<Production Example 10> [Production of polyethylene glycol fatty acid ester (C-5)]
234 parts of TFA-120 and 0.5 parts of potassium hydroxide were charged into an autoclave, and the inside of the mixed system was replaced with nitrogen, and then dehydration was carried out at 120° C. under reduced pressure (2.7 kPa) for 1 hour. Next, 765 parts (21 molar parts) of ethylene oxide were added dropwise at 150° C. while adjusting the pressure to 0.01 to 0.03 MPa. Thereafter, the mixture was neutralized with 0.5 parts of acetic acid, and a polyethylene glycol fatty acid ester (C-5) was obtained by filtration.

Example 1: Production of toner binder (E-1)
12.4 parts of toluene, 60 parts of crystalline vinyl resin (B-1), 1 part of polyethylene glycol fatty acid ester (C-1), and 40 parts of polyester (A1-1) were charged into an autoclave, and after replacing with nitrogen, the temperature was raised to 115°C in a sealed state under stirring. A mixed solution of 0.64 parts of t-butylperoxy-2-ethylhexanoate and 2.7 parts of toluene as a radical reaction initiator (d) was dropped over 0.3 hours while controlling the temperature inside the autoclave to 115°C, and polymerization was carried out. After dropping, the dropping line was washed with 2.7 parts of toluene. After further holding at the same temperature for 0.7 hours, the solvent was removed at 110°C and under a reduced pressure of 0.5 to 2.5 kPa for 2 hours to obtain a toner binder (E-1) containing polyester resin (A-1) in which polyester (A1-1) is crosslinked by a carbon-carbon bond, crystalline vinyl resin (B-1), and polyethylene glycol fatty acid ester (C-1).
The toner binder (E-1) had a glass transition temperature of 37° C., an endothermic peak top temperature of 60° C., a hydroxyl value of 20 mgKOH/g, a weight average molecular weight of 66,000, and a number average particle size of the polyester resin (A-1) in the toner binder (E-1) of 2.0 μm.

<Examples 2 to 15> [Production of toner binders (E-2) to (E-15)]
The crosslinking reaction and removal of the organic solvent were carried out in the same manner as in Example 1, except that the crystalline vinyl resin (B), polyethylene glycol fatty acid ester (C), and polyester resin (A1) were used in the amounts by weight shown in Table 3, thereby obtaining toner binders (E-2) to (E-15) according to Examples 2 to 15.

Comparative Examples 1 and 2 [Production of Toner Binders (E'-1) and (E'-2)]
The crosslinking reaction and removal of the organic solvent were carried out in the same manner as in Example 1, except that the crystalline vinyl resin (B), polyethylene glycol fatty acid ester (C), and polyester resin (A1) were used in the amounts by weight shown in Table 3, thereby obtaining toner binders (E'-1) to (E'-2) according to comparative examples 1 and 2.

The blended parts and physical properties of the toner binder obtained in each example and comparative example are shown in Table 3.

The number average particle diameter of the polyester resin (A) in the toner binder was measured by the following measurement method using the obtained toner binder.
The toner binders obtained in the examples and comparative examples were sliced into ultrathin slices of about 100 μm, and the polyester resin (A) dispersed in the crystalline vinyl resin (B) was dyed with ruthenium tetroxide for 3 minutes using a vacuum electron dyeing device (VSC1R1H manufactured by Filgen Co., Ltd.), and the dispersion state of the polyester resin (A) displayed in gray or black by ruthenium tetroxide dyeing was observed at a magnification of 10,000 times using a transmission electron microscope (TEM) on the cross section of the toner binder, and the particle diameter of the polyester resin (A) in the toner binder was calculated by image analysis using an image processing device (digital microscope VHX-700F manufactured by Keyence Corporation). Measurement was performed at the distance between two points, and when the amorphous vinyl resin (A) was a perfect circle, the diameter was measured, and when it was an ellipse, the major axis was measured. The results of randomly measuring 30 points were calculated as a number average, and the number average dispersed particle diameter of the polyester resin (A) in the toner binder was calculated.

Example 16: Production of toner (T-1)
To 86 parts of the toner binder (E-1) according to Example 1, 7 parts of a pigment carbon black [MA-100, manufactured by Mitsubishi Chemical Corporation], 1 part of a charge control agent [T-77, manufactured by Hodogaya Chemical Co., Ltd.], and 5 parts of a release agent Fischer-Tropsch wax [FT-0070, manufactured by Nippon Seiro 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 Corp.]. 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 Corp.] 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 (T-1) according to Example 16.

<Examples 17 to 30> [Production of Toners (T-2) to (T-15)]
Toners were produced in the same manner as in Example 16 using the blending amounts of the raw materials shown in Table 4, and toners (T-2) to (T-15) according to Examples 17 to 30 were obtained.

Comparative Examples 3 and 4 [Production of Toners (T'-1) and (T'-2)]
Toners were produced in the same manner as in Example 16 using the blending amounts of raw materials shown in Table 4, and toners (T'-1) and (T'-2) according to Comparative Examples 3 and 4 were obtained.

The compositions and evaluation results of the toners obtained in each example and comparative example are shown in Table 4.

[Evaluation method]
The measurement and evaluation methods for the low temperature fixing property, hot offset resistance, heat resistance storage property, glossiness, and charge rise property of the obtained toners (T-1) to (T-15) and (T'-1) to (T'-2) will be described below, including the criteria for judgment.

<Low temperature fixability>
The toner was uniformly placed on the paper surface to a concentration of 1.00 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 property.
Under these evaluation conditions, it is generally preferable that the MFT be 125° C. or less.

<Hot offset resistance>
In the same manner 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 (circumferential speed of the heating roller) of 213 mm/sec, and at heating roller temperatures ranging from 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 obtained in each example and 0.01 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed for 1 hour using a shaker. The mixture obtained after mixing 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 cohesiveness was measured using a powder tester.
The lower the value in the cohesion test determined by the method described below, the more excellent the heat resistance storage property.
Equipment: POWDER TESTER model PT-X (manufactured by Hosokawa Micron)
Sieve openings: 355 μm, 250 μm, 150 μm
Vibration amplitude: 1 mm
Vibration time: 30 seconds Operation method: Set the sieves on the vibration table of the powder tester in the following order: upper sieve 355 μm, middle sieve 250 μm, lower sieve 150 μm. Place 1 g of toner on the upper sieve and vibrate with a vibration amplitude of 1 mm for 30 seconds. Measure the weight of the toner remaining on each sieve.
Cohesion degree: Calculated from the weight of the toner used in the measurement and the weight of the toner remaining after sieving.
Cohesion (%) = (U/N + M/N x 3/5 + L/N x 1/5) x 100
U: weight of upper section, M: weight of middle section, L: weight of lower section, N: weight of sample (1g)
The heat-resistant storage stability was evaluated according to the following criteria, with A being the most excellent, followed by B, C, D, and E, and the heat-resistant storage stability being excellent if the evaluation result was A, B, C, or D.
[Judgment criteria]
A: Less than 5% B: 5% to less than 6% C: 6% to less than 7% D: 7% to less than 8% E: 8% or more

<Glossiness>
The toner was placed on the paper surface and fixed in the same manner as described above for low temperature fixability.
Next, a white cardboard is placed under the paper surface on which the toner has been fixed, and the glossiness (%) of the printed image is measured at an incidence angle of 60 degrees using a glossmeter (IG-330, manufactured by Horiba, Ltd.) at 5°C intervals from a temperature equal to or higher than the temperature at which cold offset occurs (MFT) to the temperature at which hot offset occurs, and the highest glossiness (maximum glossiness) (%) within that range is used as an index of the glossiness of the toner.
For example, if the value is 10% at 120° C., 15% at 125° C., 20% at 130° C., and 18% at 135° C., then 20% at 130° C. is the highest value and so 20% is adopted.
The higher the gloss level, the more excellent the gloss is, and the gloss was evaluated according to the following criteria: A, B, C, and D are the order of superiority, and if the evaluation result is A, B, or C, the gloss is excellent.
[Judgment criteria]
A: 13% or more B: 10% or more but less than 13% C: 9% or more but less than 10% D: Less than 9%

<Charge build-up>
0.5 g of the toner and 20 g of ferrite carrier (F-150, manufactured by Powder Tech Co., Ltd.) were placed in a 50 mL glass bottle and conditioned at 23° C. and 50% relative humidity for 8 hours or more. Next, the mixture was subjected to friction stirring at 50 rpm for 6 seconds and 600 seconds using a Turbula shaker mixer, and the charge amount at each time was measured.
A blow-off charge amount measuring device [manufactured by Toshiba Chemical Co., Ltd.] was used for the measurement. "Charge amount at 6 seconds of friction time/charge amount at 600 seconds of friction time" was calculated, and this was used as an index of charge rise property, and charge rise property was evaluated according to the following criteria. The following criteria are A, B, C, and D in order of superiority, and if the evaluation result is A, B, or C, the charge rise property is excellent.
[Judgment criteria]
A: 0.65 or more B: 0.60 or more and less than 0.65 C: 0.55 or more and less than 0.60 D: Less than 0.55

As is clear from the evaluation results in Table 4, the toners (T-1) to (T-15) according to Examples 16 to 30 all achieved excellent results in all performance evaluations.
On the other hand, the toners (T'-1) and (T'-2) according to Comparative Examples 3 and 4 were poor in some performance items.

The toner binder of the present invention has excellent heat resistance storage stability, gloss and charge rise property while maintaining low temperature fixing property and hot offset resistance, and can be suitably used as a toner binder for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing and the like.
Further, the composition is suitable for use as an additive for paints, an additive for adhesives, particles for electronic paper, and the like.

Claims (5)

A toner binder containing polyester resin (A), crystalline vinyl resin (B) and polyethylene glycol fatty acid ester (C), wherein the polyester resin (A) is a resin in which polyester (A1) is crosslinked by carbon-carbon bonds, the crystalline vinyl resin (B) is a polymer containing monomer (a) as an essential constituent monomer, the monomer (a) is a (meth)acrylate having 21 to 40 carbon atoms and a chain hydrocarbon group, the polyester resin (A) is dispersed as particles in the toner binder, and the number average particle size of the polyester resin (A) in the toner binder is 0.1 to 7.5 μm. The toner binder according to claim 1, wherein the polyethylene glycol fatty acid ester (C) is an ethylene oxide adduct of a mixed fatty acid containing a saturated fatty acid (c1) having 14 to 18 carbon atoms and an unsaturated fatty acid (c2) having 14 to 18 carbon atoms. The toner binder according to claim 1 or 2, wherein the weight ratio of the polyethylene glycol fatty acid ester (C) is 0.02 to 3.00% by weight based on the weight of the toner binder. The toner binder according to claim 1 or 2, wherein the weight ratio of the monomer (a) among the monomers constituting the crystalline vinyl resin (B) is 15 to 93% by weight based on the weight of the crystalline vinyl resin (B). 3. The toner binder according to claim 1, wherein a weight ratio of the crystalline vinyl resin (B) to the polyethylene glycol fatty acid ester (C) [(B)/(C)] is 20 to 1,000.