JP2020052153A - Toner binder and toner - Google Patents

Abstract

To provide a toner binder and toner that satisfy all of the crushability, heat-resistant storability, charging characteristic, and durability, while keeping the low temperature fixability and hot offset resistance.SOLUTION: The toner binder includes a polyester resin (A) and a vinyl resin (B). (A) is a polyester resin obtained by poly-condensing the component including an alcohol component (x) and a carboxylic acid component (y), and (x) includes an ethylene oxide addition product of an aromatic diol. (B) includes a polyfunctional vinyl monomer (a) as a constituting monomer. The weight ratio of (a) in the monomer constituting (B) is 0.1-10 wt.% using a total weight of the monomer as the reference.SELECTED DRAWING: None

Description

  The present invention relates to a toner binder and a toner.

2. Description of the Related Art In recent years, with the development of electrophotographic systems, demand for electrophotographic apparatuses such as copying machines and laser printers has been rapidly increasing, and the demand for their performance has also become more sophisticated.
Conventionally, for full-color electrophotography, a latent image based on color image information is formed on a latent image carrier such as an electrophotographic photosensitive member, the latent image is developed with a toner of a corresponding color, and then the toner image is transferred. A method and an apparatus for obtaining a multicolor image by heating and fixing a toner image on a transfer material after repeating an image forming process of transferring the image on a material are known.

  In order to pass these processes without any problems, the toner must first maintain a stable charge amount, and then need to have good fixability to paper. Further, since the apparatus has a heating element in the fixing unit, the temperature rises in the apparatus. Therefore, it is required that the toner does not block in the apparatus.

Further, there is a strong demand for improvement in the low-temperature fixing property of the toner from the viewpoint of energy saving such as reduction in energy consumption in the fixing step as well as promotion of miniaturization, high speed, and high image quality of the electrophotographic apparatus.
Further, recently, many types of paper such as recycled paper having large surface irregularities and coated paper having a smooth surface are used as a transfer material. In order to cope with the surface properties of these transfer materials, a fixing device having a wide nip such as a soft roller or a belt roller is preferably used. However, when the nip width is increased, the contact area between the toner and the fixing roller increases, and a so-called high-temperature offset phenomenon in which the molten toner adheres to the fixing roller occurs. Therefore, it is premised that offset resistance is required.
In addition to the above, a multi-color image (full color) requires much higher gloss than a black-and-white image (monochrome) because of reproduction of a photographic image and the like, and it is necessary to make the toner layer of the obtained image smooth. is there.
Therefore, it is necessary to develop low-temperature fixability while maintaining offset resistance while having high gloss, and a high-gloss toner image is required in a wide working range.

  The toner binder has a large effect on the above-mentioned toner characteristics, and polystyrene resins, styrene-acryl resins, polyester resins, epoxy resins, polyurethane resins, polyamide resins, and the like are known. Polyester resins have attracted particular attention because they easily balance the properties with the fixing properties.

As a method of expanding the fixing temperature range, a toner using a polyester resin containing an unsaturated carboxylic acid as a component has been proposed (Patent Document 1).
However, although this method can prevent the offset phenomenon at a high temperature to some extent, the fixing lower limit temperature is insufficient, and the demands for higher speed and energy saving have not yet been sufficiently answered.

On the other hand, many toners using a hybrid resin in which a polyester component and a styrene acrylic component are chemically bonded have been proposed (Patent Documents 2 to 6).
However, this method improves hot offset resistance, charging characteristics and pulverizability, but still has insufficient low-temperature fixability.

  As described above, there has been no toner binder or toner that satisfies all of pulverizability, heat-resistant storage stability, charging characteristics, and durability while maintaining low-temperature fixability and hot offset resistance.

JP 2017-003985 A JP 2007-286562 A JP 2014-235362 A JP 2008-009071 A JP 2010-128466 A JP-A-2006-047585

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner binder and toner satisfying all of pulverizability, heat-resistant storage stability, charging characteristics and durability while maintaining low-temperature fixability and hot offset resistance.

The present inventors have intensively studied to solve these problems, and as a result, have reached the present invention.
That is, the present invention relates to a toner binder containing a polyester resin (A) and a vinyl resin (B), wherein (A) is a polycondensation of a component containing an alcohol component (x) and a carboxylic acid component (y). (X) contains an ethylene oxide adduct of an aromatic diol, (B) contains a polyfunctional vinyl monomer (a) as a monomer, and (B) And (b) a toner binder containing 0.1 to 10% by weight based on the total weight of the monomers, and a toner containing the toner binder.

  According to the present invention, it is possible to provide a toner binder and toner excellent in pulverizability, heat-resistant storage stability, charging characteristics and durability while maintaining low-temperature fixability and hot offset resistance.

The toner binder of the present invention is a toner binder containing a polyester resin (A) and a vinyl resin (B), wherein (A) is a component containing an alcohol component (x) and a carboxylic acid component (y). A polyester resin obtained by polycondensation, wherein (x) contains an ethylene oxide adduct of an aromatic diol, and (B) contains a polyfunctional vinyl monomer (a) as a monomer, A toner binder wherein the weight ratio of (a) in the monomers constituting (B) is 0.1 to 10% by weight based on the total weight of the monomers.
Hereinafter, the toner binder of the present invention will be sequentially described.

  The toner binder of the present invention contains a polyester resin (A), wherein (A) is a polyester resin obtained by polycondensing a component containing an alcohol component (x) and a carboxylic acid component (y), (X) contains, as an essential component, an ethylene oxide (hereinafter sometimes referred to as “ethylene oxide” may be abbreviated as EO) adduct of an aromatic diol.

The polyester resin (A) may be either an amorphous polyester resin or a crystalline polyester resin, and is preferably an amorphous polyester resin from the viewpoint of pulverizability. The polyester resin (A) may be an unsaturated polyester or a saturated polyester resin, and is preferably a saturated polyester from the viewpoint of low-temperature fixability and pulverizability.
These may be used alone or in combination of two or more.
“Crystallinity” in the present invention means that the DSC curve has a clear endothermic peak top temperature (Tm) in the differential scanning calorimetry (also referred to as DSC measurement) described below. The term “amorphous” means that the peak temperature of the endothermic peak does not exist when the transition temperature of the sample is measured using the differential scanning calorimeter described below.
The measurement is performed using a differential scanning calorimeter {for example, “DSC210” (manufactured by Seiko Instruments Inc.)}. The first time the temperature of the crystalline resin is raised from 20 ° C. to 150 ° C. under the condition of 10 ° C./min, then cooled from 150 ° C. to 0 ° C. under the condition of 10 ° C./min. The temperature at the top of the endothermic peak in the second heating process when the second heating is performed to 150 ° C. under the condition of ° C./min is defined as the peak top temperature of the endothermic peak of the crystalline resin.
In addition, the unsaturated polyester resin in the present invention is a polyester resin having a radically reactive carbon-carbon double bond. In determining whether the resin is an unsaturated polyester resin or a saturated polyester resin, a double bond of an aromatic ring or a heterocyclic ring is not considered.

Examples of the alcohol component (x) include a monool (x1), a diol (x2), and a polyol having three or more valences (x3).
These may be used alone or in combination of two or more.

Examples of the monol (x1) include linear or branched alkyl alcohols having 1 to 30 carbon atoms (methanol, ethanol, isopropanol, 1-decanol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and ligno alcohol). Seryl alcohol, etc.).
Among these saturated monols, from the viewpoints of image strength and heat storage stability, preferred are linear or branched alkyl alcohols having 8 to 24 carbon atoms, more preferably linear alkyl alcohols having 8 to 24 carbon atoms, More preferred are dodecyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol and lignoceryl alcohol.

  The diol (x2) includes an ethylene oxide adduct of an aromatic diol (x21) as an essential component.

By containing an ethylene oxide adduct of an aromatic diol (x21) as an essential component, low-temperature fixability and heat-resistant storage stability are improved.
Examples of the ethylene oxide adduct of an aromatic diol (x21) include ethylene oxide adducts of monocyclic dihydric phenols (eg, hydroquinone) (preferably having an average number of moles of 2 to 30) (x211) and bisphenols of ethylene Oxide adducts (preferably 2 to 30 average addition moles) (x212) and the like.

Other diols (x2) include alkylene glycols having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 3-methyl- 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol and 1 , 12-dodecanediol, etc.) (x22), alkylene ether glycols having 4 to 36 carbon atoms (such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol and polytetramethylene ether glycol) (x23), carbon number To 36 alicyclic diols (such as 1,4-cyclohexane dimethanol and hydrogenated bisphenol A) (x24), and (poly) alkylene oxide adducts of the above alicyclic diols (preferably having an average number of moles of 1 to 30) (X25), aromatic diols [monocyclic dihydric phenols (for example, hydroquinone, etc.) and bisphenols, etc.] (x26) and propylene oxides of the aromatic diols (meaning "1,2-propylene oxide", hereinafter referred to as PO May be abbreviated.) Adducts (preferably an average number of moles of 2 to 30) (x27).
Among these diols (x2), alkylene glycols having 2 to 36 carbon atoms (x22) and propylene oxide adducts of aromatic diols (x27) are preferable from the viewpoint of low-temperature fixability and heat-resistant storage stability. Oxide adducts are more preferred.

  An alkylene oxide adduct that is an ethylene oxide adduct of bisphenols and a propylene oxide adduct is obtained by adding ethylene oxide or propylene oxide to bisphenols. Examples of the bisphenols include those represented by the following general formula (1).

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

  Bisphenols include, for example, bisphenol A, bisphenol F, bisphenol B, bisphenol AD, bisphenol S, trichlorobisphenol A, tetrachlorobisphenol A, dibromobisphenol F, 2-methylbisphenol A, 2,6-dimethylbisphenol A, and 2 , 2'-diethylbisphenol F, and the like, and two or more of these can be used in combination.

  From the viewpoint of low-temperature fixability and heat-resistant storage stability, the average addition mole number of the aromatic diol ethylene oxide adduct and the aromatic diol propylene oxide adduct is preferably 2 to 30 mol, more preferably 2 to 10 mol, It is more preferably 2 to 5 mol, particularly preferably 2 to 4 mol, most preferably 2 to 3.

  Examples of the trivalent or higher valent polyol (x3) include trivalent or higher valent aliphatic polyhydric alcohols having 3 to 36 carbon atoms (x31), saccharides and derivatives thereof (x32), and aliphatic polyhydric alcohols. AO adduct (average addition mole number is preferably 1 to 30) (x33), AO adduct of trisphenols (trisphenol PA or the like) (average addition mole number is preferably 2 to 30) (x34), novolak resin (Including phenol novolak and cresol novolak, and the average degree of polymerization is preferably 3 to 60), and an AO adduct (the average addition mole number is preferably 2 to 30) (x35).

  Examples of the aliphatic polyhydric alcohol having 3 to 36 carbon atoms and a valence of 3 or more (x31) include alkane polyols and intramolecular or intermolecular dehydrates thereof, such as glycerin, trimethylolethane, trimethylolpropane, and the like. Examples include pentaerythritol, sorbitol, sorbitan, polyglycerin, dipentaerythritol and the like.

  Examples of the saccharide and its derivative (x32) include sucrose and methyl glucoside.

  Among the trivalent or higher valent polyols (x3), the trivalent or higher valent aliphatic polyhydric alcohols having 3 to 36 carbon atoms (x31) from the viewpoint of compatibility between low-temperature fixing property and hot offset resistance. And an AO adduct (average degree of addition is preferably 2 to 30) (x35) of a novolak resin (including phenol novolak and cresol novolak, preferably having an average degree of polymerization of preferably 3 to 60).

  Among the ethylene oxide adducts of aromatic diols which are essential components, those which are preferable from the viewpoint of compatibility between low-temperature fixability, hot offset resistance and heat-resistant storage stability are ethylene oxide adducts of bisphenols (preferably having an average addition mole number of 2 to 2). 30) (x212), more preferably an ethylene oxide adduct of bisphenol A (average addition mole number is 2 to 5), and still more preferably an ethylene oxide adduct of bisphenol A (average addition mole number is 2 to 3). ).

  Of the alcohol components (x) other than the ethylene oxide adduct of the aromatic diol, which is an essential component, those which are preferable from the viewpoint of compatibility between low-temperature fixability, hot offset resistance and heat-resistant storage stability are bisphenol propylene oxide adducts. (The average number of moles is preferably 2 to 30), alkylene glycol having 2 to 36 carbon atoms (x22), aliphatic polyhydric alcohol having 3 to 36 or more valences having 3 to 36 carbon atoms (x31), and novolak resin ( It contains phenol novolak, cresol novolak, etc., and preferably has an average degree of polymerization of 3 to 60 AO adduct (average addition mole number is preferably 2 to 30) (x35).

As the alcohol component (x) other than the ethylene oxide adduct of the aromatic diol, which is an essential component, those more preferable from the viewpoint of heat-resistant storage stability are alkylene glycols having 2 to 10 carbon atoms and propylene oxide adducts of bisphenols (average). The number of moles of addition is preferably 2 to 5), a C3 to C36 trivalent to polyvalent aliphatic polyhydric alcohol and a novolak resin (phenol novolak, cresol novolak, etc. are included. 60) (the average number of moles of addition is preferably 2 to 30).
More preferably, it is an alkylene glycol having 2 to 6 carbon atoms, a propylene oxide adduct of bisphenol A (the average addition mole number is preferably 2 to 5) and a trivalent aliphatic polyhydric alcohol having 3 to 36 carbon atoms, Particularly preferred are ethylene glycol, propylene glycol, a propylene oxide adduct of bisphenol A (the average addition mole number is preferably 2-3) and trimethylolpropane.

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

  Examples of the carboxylic acid component (y) include an aromatic carboxylic acid (y1) and an aliphatic carboxylic acid (y2). As the carboxylic acid component (y), one type may be used, or two or more types may be used in combination.

Examples of the aromatic carboxylic acid (y1) include an aromatic dicarboxylic acid having 8 to 36 carbon atoms (such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid) and a trivalent or higher aromatic compound having 9 to 20 carbon atoms. And polycarboxylic acids (such as trimellitic acid and pyromellitic acid).
Examples of the aliphatic carboxylic acid (y2) include aliphatic dicarboxylic acids having 2 to 50 carbon atoms (such as oxalic acid, malonic acid, succinic acid, adipic acid, reparginic acid and sebacic acid), and fatty acids having 6 to 36 carbon atoms. Vinyl polymer [Mn: 450 to 10,000] of aromatic tricarboxylic acid (hexanetricarboxylic acid, etc.) and unsaturated carboxylic acid (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, and styrene / fumaric acid copolymer) And the like).

  As the carboxylic acid component (y), anhydrides and lower alkyl (C1 to C4) esters (such as methyl ester, ethyl ester and isopropyl ester) of these carboxylic acids may be used, or may be used in combination with these carboxylic acids. May be.

Among these carboxylic acid components (y), adipic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, and a combination thereof are preferable from the viewpoint of compatibility between low-temperature fixing property and hot offset resistance. .
Particularly preferred are adipic acid, terephthalic acid, trimellitic acid, and combinations thereof. Anhydrides and lower alkyl esters of these acids are likewise preferred.

  In the toner binder of the present invention, the peak top molecular weight (Mp) of the polyester resin (A) in gel permeation chromatography (GPC) is from 3,000 to 3,000 from the viewpoints of low-temperature fixability, hot offset resistance, and heat storage stability. It is preferably 10,000.

In the present invention, the peak top molecular weight (Mp), the number average molecular weight (hereinafter sometimes abbreviated as Mn), and the weight average molecular weight (hereinafter sometimes abbreviated as Mw) of the polyester resin (A) are as follows. It can be measured under the following conditions using GPC.
Apparatus (example): HLC-8120 manufactured by Tosoh Corporation
Column (example): 2 TSK GEL GMH6 [manufactured by Tosoh Corporation]
Measurement temperature: 40 ° C
Sample solution: 0.25% by weight THF solution Solution injection volume: 100 μL
Detector: Refractive index detector Reference substance: Standard polystyrene (TSK standard POLYSTYRENE) manufactured by Tosoh Corporation 12 points (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)
In the measurement of the molecular weight, a sample was dissolved in THF so as to have a concentration of 0.25% by weight, and the insoluble matter was filtered off with a glass filter to obtain a sample solution.

In the toner binder of the present invention, the polyester resin (A) can be produced in the same manner as a known polyester.
For example, the reaction can be performed by reacting the components in an inert gas (nitrogen gas or the like) atmosphere at a reaction temperature of preferably 150 to 280 ° C, more preferably 160 to 250 ° C, and still more preferably 170 to 235 ° C. it can. The reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours, from the viewpoint of reliably performing the polycondensation reaction.

At this time, an esterification catalyst can be used if necessary.
Examples of the esterification catalyst include a tin-containing catalyst (eg, dibutyltin oxide), antimony trioxide, and a titanium-containing catalyst [eg, titanium alkoxide, potassium oxalate, titanium terephthalate, titanium terephthalate alkoxide, JP-A-2006-243715. Patent No. 1993, Titanium diisopropoxy bis (triethanol aminate), titanium dihydroxy bis (triethanol aminate), titanium monohydroxy tris (triethanol aminate), titanyl bis (triethanol aminate) and the like Intramolecular polycondensates etc. and catalysts described in JP-A-2007-11307 (titanium tributoxy terephthalate, titanium triisopropoxy terephthalate, titanium diisopropoxy diterephthalate, etc.) ], Zirconium-containing catalysts (e.g. zirconyl acetate, etc.), and zinc acetate, and the like. Among these, a titanium-containing catalyst is preferred. It is also effective to reduce the pressure in order to increase the reaction rate at the end of the reaction.

  The total charging ratio of the alcohol component (x) and the carboxylic acid component (y) of the polyester resin (A) used in the reaction is preferably an equivalent ratio of hydroxyl group to carboxyl group ([OH] / [COOH]), preferably 2 / The ratio is from 1 to 1/2, more preferably from 1.5 / 1 to 1 / 1.3, even more preferably from 1.4 / 1 to 1 / 1.2.

In the toner binder of the present invention, the glass transition temperature (Tg _A ) of the polyester resin (A) is preferably from 50 to 70 ° C.
When the Tg _A is 70 ° C. or less, the low-temperature fixability is good, and when the Tg _A is 50 ° C. or more, the heat-resistant storage stability is good. In addition, the glass transition temperature (Tg _A ) of the polyester resin (A) is measured by a method (DSC method) specified in ASTM D3418-82 using, for example, DSC Q20 manufactured by TA Instruments.

  The acid value of the polyester resin (A) is preferably from 10 to 30 mgKOH / g from the viewpoints of charging stability and heat-resistant storage stability. The acid value of the polyester resin (A) can be measured by a method specified in JIS K0070 (1992).

  The toner binder of the present invention contains a vinyl resin (B) and a polyfunctional vinyl monomer (a) as an essential component as a monomer constituting (B). The weight ratio of (a) in the monomers constituting (B) is 0.1 to 10% by weight based on the total weight of the monomers. The vinyl resin contains the polyfunctional vinyl monomer (a) as an essential component, and the above weight ratio improves hot offset resistance while maintaining pulverizability.

Examples of the polyfunctional vinyl monomer (a) include a divalent vinyl monomer and a trivalent or higher vinyl monomer.
These may be used alone or in combination of two or more.

  Examples of the divalent vinyl monomer include divinylbenzene, 1,5-hexadiene, di (meth) acrylate of glycerin, di (meth) acrylate of trimethylolpropane, and di (meth) acrylate of 3-hydroxy-1,5-pentanediol. And di (meth) acrylate of 2-hydroxy-2-ethyl-1,3-propanediol.

  Examples of the trivalent or higher-valent vinyl monomer include trimethylolpropane tri (meth) acrylate, triallyl 1,3,5-benzenetricarboxylate, glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate; and trimethylolpropane Tri (meth) acrylate of ethylene oxide adduct, tetra (meth) acrylate of pentaerythritol, penta (meth) acrylate of dipentaerythritol and hexa (meth) acrylate of dipentaerythritol; tetra of ethylene oxide adduct of dipentaerythritol Penta (meth) acrylate of ethylene oxide adduct of (meth) acrylate and dipentaerythritol, penta (meth) acrylate of propylene oxide adduct of dipentaerythritol ) Acrylate, and the like.

  Among these polyfunctional vinyl monomers (a), divinylbenzene and trimethylolpropane triacrylate are preferred from the viewpoints of low-temperature fixability, hot offset resistance and pulverizability.

  The vinyl resin (B) is a monomer constituting the monomer (b) other than the polyfunctional vinyl monomer (a) as a constituent monomer from the viewpoints of hot offset resistance, heat storage stability, pulverizability and charge stability of the toner. It may be contained as a monomer. Examples of the monomer (b) include a styrene monomer (b1), a (meth) acrylic monomer (b2), a vinyl ester monomer (b3), a monomer having a nitrile group (b4), and the like. Are preferred. As the monomer (b), one type may be used alone, or two or more types may be used in combination.

  Examples of the styrene-based monomer (b1) include styrene and alkylstyrenes having 1 to 3 carbon atoms in an alkyl group (for example, α-methylstyrene and p-methylstyrene).

  Examples of the (meth) acrylic monomer (b2) include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl (meth) acrylate, and ethyl-2- ( (Hydroxymethyl) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and the like.

  Examples of the vinyl ester monomer (b3) include vinyl acetate, vinyl propionate, and isopropenyl acetate.

  Examples of the monomer (b4) having a nitrile group include acrylonitrile.

  Among these monomers (b), styrene, acrylic acid, butyl acrylate, ethyl acrylate and acrylonitrile are preferred.

  As described above, the weight ratio of the polyfunctional vinyl monomer (a) in the monomer constituting the vinyl resin (B) is 0.1 to 10% by weight based on the total weight of the monomers. If it is less than 0.1% by weight, the hot offset resistance deteriorates, and if it is more than 10% by weight, the pulverizability deteriorates.

  The monomer constituting the vinyl resin (B) preferably further contains the monomer (b), and the monomer (b) is 90 to 99.9% by weight based on the total weight of the monomers. % Is more preferable.

The vinyl resin (B) in the toner binder of the present invention can be obtained by subjecting a monomer composition containing a polyfunctional vinyl monomer (a) and optionally a monomer (b) to a known method (JP-A-5-117330). Can be produced by polymerization according to the method described in Japanese Patent Application Laid-Open Publication No. H10-207, etc.). For example, it can be synthesized by a solution polymerization method in which the above monomer is reacted with a radical reaction initiator (such as azobisisobutyronitrile) in a solvent (such as toluene).
In the solution polymerization method, producing the vinyl resin (B) in the presence of the polyester resin (A) instead of the solvent can uniformly crosslink the vinyl resin (B) in the polyester resin (A), It is preferable from the viewpoint of achieving both pulverizability and hot offset resistance.

  The radical reaction initiator (c) is not particularly limited, and examples thereof include an inorganic peroxide (c1), an organic peroxide (c2), and an azo compound (c3). Further, these radical reaction initiators may be used in combination.

  Examples of the inorganic peroxide (c1) include, but are not particularly limited to, hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

  The organic peroxide (c2) is not particularly restricted but includes, for example, benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butyl) Peroxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di-t- Butylperoxyhexine-3, acetyl peroxide, isobutyryl peroxide, octanolol peroxide, decanolyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t -Butyl peroxyisobutyrate, t-butyl peroxy neodecanoate, cumyl peroxy Neodecanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, t-butyl Examples include peroxyisopropyl monocarbonate and t-butyl peroxyacetate.

  The azo compound and diazo compound (c3) are not particularly restricted but include, for example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 '-Azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and the like.

  Among these, organic peroxide (c2) is preferable because it has a high initiator efficiency and does not produce toxic by-products such as cyanide, and t-butylperoxy-2-ethylhexanoate and di-t are preferable. -Butyl peroxide is more preferred.

In the toner binder of the present invention, the glass transition temperature (Tg _B ) of the vinyl resin (B) is preferably −35 to 47 ° C.
When Tg _B is 47 ° C. or less, low-temperature fixability becomes good, and when Tg _B is −35 ° C. or more, heat-resistant storage stability becomes good. The glass transition temperature (Tg _B ) of the vinyl resin (B) is a value calculated by the Fox-Flory equation, 1 / Tg12 = φ (1) / Tg1 + φ (2) / Tg2. Tg12 corresponds to Tg of the vinyl resin (B) at an absolute temperature (unit K), and Tg1 and Tg2 are glass transition temperatures (units K) of respective homopolymers of the monomers constituting the vinyl resin (B). , Φ (1) and φ (2) are weight percentages of the monomers constituting the vinyl resin (B).

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

The acid value of the vinyl resin (B) is preferably 55 mgKOH / g or less from the viewpoint of low-temperature fixability.
The acid value of the vinyl resin (B) is calculated by weight percentage using the acid value of each monomer used in the polymerization of the vinyl resin (B) and the weight of the monomer.

The toner binder of the present invention can be obtained, for example, by mixing the polyester resin (A) and the vinyl resin (B) by a method described below, and the vinyl resin (B) is produced in the presence of the polyester resin (A). This is preferable from the viewpoint that the vinyl resin (B) can be uniformly crosslinked in the polyester resin (A), and the pulverizability and the hot offset property are compatible.
The toner binder of the present invention may contain a resin other than the polyester resin (A) and the vinyl resin (B) and a known additive (such as a release agent).

  The weight ratio [(A) / (B)] of the polyester resin (A) and the vinyl resin (B) of the toner binder of the present invention is determined from the viewpoint of compatibility between low-temperature fixability, hot offset resistance, and heat-resistant storage stability. 50/50 to 90/10 is preferred.

The toner binder of the present invention preferably satisfies the following relational expression (1) from the viewpoint of low-temperature fixability and hot offset resistance. By satisfying the relational expression (1), the compatibility between the polyester resin (A) and the vinyl resin (B) is improved, and a sufficient fixing area is secured. In order to satisfy the relational expression (1), the SP values of the polyester resin (A) and the vinyl resin (B) should be close to each other. In particular, the weight ratio of the monomer (b) used in the vinyl resin (B) should be It needs to be considered. Specifically, acrylonitrile (SP value: 14.4) and acrylic acid (SP value: 14.0), which are monomers (b) having a higher SP value than the polyester resin (A), and the polyester resin (A) The weight ratio of styrene (SP value: 10.6), butyl acrylate (SP value: 9.8) and ethyl acrylate (SP value: 10.2), which are monomers (b) having lower SP values, Take into account.
Relational expression (1): | SP (A) -SP (B) | ≦ 1.3 (cal / cm ³ ) ^0.5

In the relational expression (1), SP (A) is a solubility parameter (SP value) of the polyester resin (A), and SP (B) is an SP value of the vinyl resin (B).
The SP value (cal / cm ³ ) ^0.5 of the toner binder of the present invention was calculated by the method described in Polymer engineering and science, Vol. 14, pages 151 to 154 by Robert F Fedors et al. It is a value at ° C.

The glass transition temperature (Tg) of the toner binder of the present invention is preferably 50 to 70 ° C.
When the Tg of the toner binder is 70 ° C. or less, the low-temperature fixability becomes good, and when it is 50 ° C. or more, the heat-resistant storage stability becomes good. The glass transition temperature (Tg) is measured by a method (DSC method) specified in ASTM D3418-82 using, for example, DSC Q20 manufactured by TA Instruments.

The toner binder of the present invention, the difference in the glass transition temperature of the glass transition temperature of the polyester resin _(A) (Tg A) and the vinyl resin _{(B) (Tg B) [} (Tg A) - (Tg B)] is 15 ℃ It is preferable from the viewpoint of the low-temperature fixability that the above-mentioned value is satisfied. The greater the difference in the glass transition temperature, the more easily the effect on the low-temperature fixability is obtained. The reason will be described below.
Low-temperature fixability is governed by the viscosity of the toner binder. On the other hand, when the viscosities of the polyester resin (A) and the vinyl resin (B) are compared, the viscosity of the vinyl resin (B) is higher. By lowering the glass transition temperature (Tg _B ) of the vinyl resin (B), the viscosity of the vinyl resin (B) in the fixing temperature range can be reduced, and the viscosity of the toner binder can be lowered. Further, since the vinyl resin (B) contains the polyfunctional vinyl monomer (a), it has a crosslinked structure, and satisfies the heat-resistant storage stability even at a low glass transition temperature.
In order to satisfy this range, it is particularly preferable to lower the glass transition temperature of the vinyl resin (B), and trimethylolpropane triacrylate (monomer having a lower glass transition temperature than the polyester resin (A)) Glass transition temperature of a homopolymer of the above: 10 ° C.), butyl acrylate (glass transition temperature of a monomer homopolymer: −17 ° C.) and ethyl acrylate (glass transition temperature of a monomer homopolymer: 11 ° C.) Can be controlled.

The acid value of the toner binder of the present invention is preferably 10 to 30 mgKOH / g or less.
The acid value of the toner binder can be measured by a method specified in JIS K0070 (1992).

The toner binder of the present invention may contain a THF-insoluble component in some cases.
The content (% by weight) of the THF-insoluble component in the toner binder of the present invention is preferably 50% by weight or less, more preferably 5 to 5%, from the viewpoint of achieving both hot offset resistance and low-temperature fixability. 30% by weight.

The content (% by weight) of the THF-insoluble component in the toner binder of the present invention is determined by the following method.
50 mL of THF is added to 0.5 g of the sample and the mixture is stirred and refluxed for 3 hours. After cooling, insoluble matter is filtered off with a glass filter, and the resin content on the glass filter is dried under reduced pressure at 80 ° C. for 3 hours. The weight of the dried resin on the glass filter is the weight of the THF-insoluble matter, and the weight obtained by subtracting the weight of the THF-insoluble matter from the weight of the sample is the weight of the THF-soluble matter. Calculate the weight% of the minute.

The method for producing the toner binder will be described.
The toner binder is not particularly limited as long as it contains the polyester resin (A) and the vinyl resin (B). For example, the mixing method for mixing the polyester resin (A), the vinyl resin (B), and the additives is as follows. A known method generally used may be used, and examples of the mixing method include powder mixing, melt mixing, and solvent mixing. Further, the polyester resin (A), the vinyl resin (B) and the additives used as required may be mixed at the same time when the toner is manufactured. Among these methods, a melt-mixing method that mixes uniformly and does not require solvent removal is preferred.

Examples of a mixing device for mixing powder include a Henschel mixer, a Nauta mixer, and a Banbury mixer. Preferably, it is a Henschel mixer.
Examples of the mixing device in the case of melt mixing include a batch type mixing device such as a reaction tank and a continuous type mixing device. In order to mix uniformly at an appropriate temperature in a short time, a continuous mixing apparatus is preferable. Examples of the continuous mixing device include a static mixer, an extruder, a continuous kneader, and a three-roll mixer.

  As a method of mixing the solvent, a method of dissolving the polyester resin (A) and the vinyl resin (B) in a solvent (ethyl acetate, THF, acetone, or the like) and homogenizing the mixture, and then removing the solvent and pulverizing, A method of dissolving a polyester resin (A) and the above vinyl resin (B) in a solvent (ethyl acetate, THF, acetone, etc.), dispersing in water, granulating and removing a solvent, and constituting the vinyl resin (B) And a method of mixing the monomer to be formed with the polyester resin (A) to produce the vinyl resin (B) and mixing with the (A).

  Among them, a method of producing a vinyl resin (B) in the presence of a polyester resin (A), that is, a method of producing a vinyl resin (B) by mixing a monomer constituting the vinyl resin (B) and the polyester resin (A) The method of mixing with the polyester resin (A) while mixing is preferable. As a specific method for performing the melt mixing, a mixture of the polyester resin (A) and the monomer constituting the vinyl resin (B) is charged into an autoclave. A method in which the solution is heated to a temperature at which a solution is formed, and simultaneously, a radical reaction initiator (c) is injected at a constant rate, and the reaction is carried out at a temperature of 50 to 200 ° C.

  The toner of the present invention contains the toner binder of the present invention.

  The toner of the present invention may contain one or more known additives selected from a colorant, a release agent, a charge control agent, a fluidizing agent, and the like, if necessary, in addition to the toner binder of the present invention.

As the colorant, any of dyes and pigments used as colorants for toner can be used. For example, carbon black, iron black, Sudan Black SM, Fast Yellow G, Benzidine Yellow, Pigment Yellow, India First 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, Oil Pink OP, and the like. Or a mixture of two or more. If necessary, a magnetic powder (a powder of a ferromagnetic metal such as iron, cobalt, or nickel or a compound such as magnetite, hematite, or ferrite) can be contained 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 using magnetic powder, the amount is preferably 20 to 150 parts by weight, more preferably 40 to 120 parts by weight.

  As the release agent, those having a flow softening point (T1 / 2) of 50 to 170 ° C. by a flow tester are preferable, and low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene polyethylene copolymer, polyolefin wax, microcrystalline wax, Aliphatic hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax and their oxides, carnauba wax, montan wax, sasol wax and their deoxidizing waxes, ester waxes such as fatty acid ester waxes, fatty acid amides, fatty acids , Higher alcohols, metal salts of fatty acids, and mixtures thereof.

The flow softening point (T1 / 2) of the release agent was measured under the following conditions.
<Method of measuring flow softening point (T1 / 2)>
Using a descending flow tester [for example, CFT-500D, manufactured by Shimadzu Corporation], a load of 1.96 MPa was applied by a plunger while heating 1 g of the measurement sample at a heating rate of 6 ° C./min. Extrude from a nozzle with a diameter of 1 mm and a length of 1 mm, draw a graph of "Plunger descent (flow value)" and "Temperature", and graph the temperature corresponding to 1/2 of the maximum value of the plunger descent. And this value (the temperature at which half of the measurement sample flows out) is defined as the flow softening point (T1 / 2).

  Examples of the polyolefin wax include (co) polymers of olefins (e.g., ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene, and mixtures thereof) obtained by (co) polymerization. And heat-reduced polyolefins], oxides of olefin (co) polymers with oxygen and / or ozone, maleic acid-modified olefin (co) polymers [e.g., maleic acid and its derivatives (maleic anhydride, Modified products of monomethyl maleate, monobutyl maleate and dimethyl maleate), olefins and unsaturated carboxylic acids [(meth) acrylic acid, itaconic acid, maleic anhydride, etc.] and / or alkyl esters of unsaturated carboxylic acids [(meta A) alkyl acrylate (alkyl having 1 to 18 carbon atoms) ester; Maleic acid alkyl (C1-18 alkyl) copolymers of an ester, etc.] or the like, and Sasol wax.

  Examples of the higher alcohol include aliphatic alcohols having 30 to 50 carbon atoms, such as triacontanol. Fatty acids include fatty acids having 30 to 50 carbon atoms, such as triacontancarboxylic acid.

  Examples of the charge control agent include a nigrosine dye, a triphenylmethane dye containing a tertiary amine as a side chain, a quaternary ammonium salt, a polyamine resin, an imidazole derivative, a quaternary ammonium base-containing polymer, a metal-containing azo dye, a copper phthalocyanine dye, Examples include salicylic acid metal salts, boron complexes of benzylic acid, sulfonic acid group-containing polymers, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers.

Examples of the fluidizing agent include colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.

The content of the toner binder in the toner is preferably 45 to 92% by weight based on the weight of the toner.
The content of the colorant is preferably 0.5 to 50% by weight based on the weight of the toner.
The content of the release agent is preferably 1 to 10% by weight based on the weight of the toner.
The content of the charge control agent is preferably 0.5 to 7.5% by weight based on the weight of the toner.
The content of the fluidizing agent is preferably 0.1 to 4% by weight based on the weight of the toner.
The total amount of the additives is preferably 5 to 50% by weight based on the weight of the toner.
When the composition ratio of the toner is in the above range, a toner having good hot offset resistance, heat-resistant storage stability, and charging stability can be easily obtained.

The toner of the present invention may be obtained by any known method such as a kneading and pulverizing method, an emulsification phase inversion method, and a polymerization method.
For example, when a toner is obtained by a kneading and pulverizing method, after dry blending components constituting the toner excluding a fluidizing agent, they are melt-kneaded, then coarsely pulverized, and finally pulverized using a jet mill pulverizer or the like. By further classifying, the fine particles having a volume average particle size (D50) of preferably 5 to 20 μm can be produced by mixing with a fluidizing agent.
The volume average particle size (D50) is measured using a Coulter counter (for example, trade name: Multisizer III [manufactured by Beckman Coulter, Inc.]).

  When the toner is obtained by the emulsification phase inversion method, it is possible to dissolve or disperse the components constituting the toner excluding the fluidizing agent in an organic solvent, emulsify the mixture by adding water, and then separate and classify the emulsion. it can. The volume average particle diameter of the toner is preferably 3 to 15 μm.

The toner of the present invention is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite whose surface is coated with a resin (acrylic resin, silicone resin, etc.) as necessary, to form an electric latent image. Used as a developer. When carrier particles are used, the weight ratio between the toner and the carrier particles is preferably from 1/99 to 99/1. Also, instead of the carrier particles, it can rub against a member such as a charging blade to form an electric latent image.
In addition, the toner of the present invention may not include carrier particles.

  The toner of the present invention is fixed on a support (paper, polyester film, or the like) by a copying machine, a printer, or the like to form a recording material. As a method of fixing to a support, a known hot roll fixing method, a flash fixing method and the like can be applied.

  The toner and toner binder of the present invention are used for developing an electrostatic image or a magnetic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like. More specifically, it is used for developing an electrostatic image or a magnetic latent image particularly suitable for full color.

  Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, “parts” means “parts by weight” unless otherwise specified.

<Production Example 1> [Production of polyester resin (A-1)]
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introducing pipe, 322 parts of a 2-mol adduct of bisphenol A, 419 parts of a 2-mol adduct of bisphenol A, 274 parts of terephthalic acid, and titanium diisopropoxy as a catalyst were used. 2.5 parts of bis (triethanolaminate) was added, and the mixture was reacted at 230 ° C. under a nitrogen stream while distilling off generated water for 3 hours. Next, after reacting for 6 hours under reduced pressure of 0.5 to 2.5 kPa, the temperature was lowered to 180 ° C. After adding 42 parts of trimellitic anhydride and reacting under normal pressure for 1 hour, it was taken out to obtain a polyester resin (A-1).

<Production Examples 2 to 4> [Production of polyester resins (A-2) to (A-4)]
An alcohol component (x) and a carboxylic acid component (y) described in Table 1 were charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and the reaction was carried out in the same manner as in Production Example 1 except for the above. Polyester resins (A-2) to (A-4) were obtained.

<Comparative Production Example 1> [Production of polyester resin (A'-1)]
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introducing pipe, 620 parts of a PO2 mole adduct of bisphenol A, 163 parts of a PO3 mole adduct of bisphenol A, 245 parts of terephthalic acid, and titanium diisopropoxy as a catalyst were used. 2.5 parts of bis (triethanolaminate) was added, and the mixture was reacted at 230 ° C. under a nitrogen stream while distilling off generated water for 3 hours. Next, after reacting for 5 hours under reduced pressure of 0.5 to 2.5 kPa, the temperature was lowered to 180 ° C. 1 part of tert-butylcatechol is added as a polymerization inhibitor, and 19 parts of fumaric acid is further added. After reacting for 8 hours under reduced pressure of 0.5 to 2.5 kPa, 9 parts of trimellitic anhydride is added, and the mixture is added under normal pressure. The reaction was carried out for 1 hour, and then taken out to obtain a polyester resin (A'-1) having no ethylene oxide adduct of an aromatic diol.

  Table 1 shows the composition and physical properties of the polyester resin.

<Example 1> [Production of toner binder (C-1)]
700 parts of a polyester resin (A-1) in an autoclave, 103 parts of styrene as a monomer constituting the vinyl resin (B-1) [manufactured by Idemitsu Kosan Co., Ltd .; the same applies hereinafter], butyl acrylate [Mitsubishi Chemical Corporation ), Acrylonitrile [manufactured by Nacalai Tex Co., Ltd., the same applies] 88 parts, trimethylolpropane triacrylate [manufactured by Shin-Nakamura Chemical Co., Ltd., the same applies] 5.4 parts, radical polymerization started 3 parts of t-butylperoxy-2-ethylhexanoate [Perbutyl I, manufactured by NOF CORPORATION, the same applies hereinafter] as an agent (c), and after purging with nitrogen, the mixture is uniformly stirred at 70 ° C. and sealed. To 120 ° C. Further, after keeping the temperature at the same temperature for 3 hours to complete the polymerization, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C-C) containing the polyester resin (A-1) and the vinyl resin (B-1) was removed. 1) was obtained.
Table 2 shows the composition and physical properties of the vinyl resin, and Table 3 shows the composition and physical properties of the toner binder.

<Example 2> [Production of toner binder (C-2)]
In an autoclave, 600 parts of the polyester resin (A-1), 251 parts of butyl acrylate as a monomer constituting the vinyl resin (B-2), 146 parts of acrylonitrile, 3.6 parts of trimethylolpropane triacrylate, radical polymerization start After 4 parts of t-butylperoxy-2-ethylhexanoate was charged as the agent (c), the atmosphere was replaced with nitrogen, and the mixture was uniformly stirred at 70 ° C and heated to 120 ° C in a sealed state. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder containing the polyester resin (A-1) and the vinyl resin (B-2) (C- 2) was obtained.

<Example 3> [Production of toner binder (C-3)]
800 parts of a polyester resin (A-2), 11 parts of styrene as a monomer constituting the vinyl resin (B-3), 94 parts of butyl acrylate, 62 parts of acrylonitrile, acrylic acid [manufactured by Mitsubishi Chemical Corporation] in an autoclave. 14 parts, divinylbenzene [manufactured by Tokyo Kasei Kogyo Co., Ltd., the same as below], 20 parts, and 1.5 parts of t-butylperoxy-2-ethylhexanoate as a radical polymerization initiator (c) were charged. After purging with nitrogen, the mixture was uniformly stirred at 70 ° C., and heated to 120 ° C. in a sealed state. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C-C) containing the polyester resin (A-2) and the vinyl resin (B-3) was removed. 3) was obtained.

<Example 4> [Production of toner binder (C-4)]
In an autoclave, 750 parts of the polyester resin (A-3), 92 parts of styrene as a monomer constituting the vinyl resin (B-4), 104 parts of butyl acrylate, 46 parts of acrylonitrile, 9 parts of divinylbenzene, a radical polymerization initiator As (c), 1.5 parts of t-butylperoxy-2-ethylhexanoate was charged, and after substituting with nitrogen, the mixture was uniformly stirred at 70 ° C and heated to 120 ° C in a sealed state. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced to 0.5 to 2.5 kPa for 3 hours, and the toner binder (C-C) containing the polyester resin (A-3) and the vinyl resin (B-4) was removed. 4) was obtained.

<Example 5> [Production of toner binder (C-5)]
In an autoclave, 500 parts of the polyester resin (A-4), 299 parts of butyl acrylate as a monomer constituting the vinyl resin (B-5), and 199 parts of ethyl acrylate [manufactured by Tokyo Chemical Industry Co., Ltd .; , 2 parts of trimethylolpropane triacrylate and 5 parts of t-butylperoxy-2-ethylhexanoate as a radical polymerization initiator (c) were purged with nitrogen, and then uniformly stirred at 70 ° C. and sealed. The temperature was raised to ° C. After the polymerization was completed by keeping the temperature at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C-C) containing the polyester resin (A-4) and the vinyl resin (B-5) was removed. 5) was obtained.

<Example 6> [Production of toner binder (C-6)]
900 parts of a polyester resin (A-3) in an autoclave, 5.4 parts of styrene as a monomer constituting the vinyl resin (B-3), 47 parts of butyl acrylate, 31 parts of acrylonitrile, 7 parts of acrylic acid, divinylbenzene 9.8 parts, 1 part of t-butyl peroxy-2-ethylhexanoate as a radical polymerization initiator (c) was charged, and after substituting with nitrogen, the mixture was uniformly stirred at 70 ° C, and then heated to 120 ° C in a closed state. did. After the polymerization was completed by keeping the temperature at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C-C) containing the polyester resin (A-3) and the vinyl resin (B-3) was removed. 6) was obtained.

<Example 7> [Production of toner binder (C-7)]
700 parts of a polyester resin (A-4) in an autoclave, 103 parts of styrene, 103 parts of butyl acrylate, 88 parts of acrylonitrile, 5.4 parts of trimethylolpropane triacrylate as monomers constituting the vinyl resin (B-1) Then, 2 parts of t-butylperoxy-2-ethylhexanoate was charged as a radical polymerization initiator (c), and after substituting with nitrogen, the mixture was uniformly stirred at 70 ° C and heated to 120 ° C in a sealed state. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder containing the polyester resin (A-4) and the vinyl resin (B-1) (C- 7) was obtained.

<Example 8> [Production of toner binder (C-8)]
800 parts of a polyester resin (A-3) in an autoclave, 73 parts of styrene as a monomer constituting the vinyl resin (B-4), 83 parts of butyl acrylate, 37 parts of acrylonitrile, 7.2 parts of divinylbenzene, radical polymerization As an initiator (c), 2 parts of di-t-butyl peroxide [Perbutyl D, manufactured by NOF CORPORATION, the same applies hereinafter] are charged, and after purging with nitrogen, the mixture is uniformly stirred at 70 ° C, and sealed up to 120 ° C. The temperature rose. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced to 0.5 to 2.5 kPa for 3 hours, and the toner binder (C-C) containing the polyester resin (A-3) and the vinyl resin (B-4) was removed. 8) was obtained.

<Comparative Example 1> [Production of toner binder (C'-1)]
700 parts of a polyester resin (A'-1) in an autoclave, 188 parts of butyl acrylate as a monomer constituting the vinyl resin (B-2), 109 parts of acrylonitrile, 2.7 parts of trimethylolpropane triacrylate, radical polymerization After 3 parts of t-butylperoxy-2-ethylhexanoate was charged as an initiator (c), the atmosphere was replaced with nitrogen, and the mixture was uniformly stirred at 70 ° C and heated to 120 ° C in a closed state. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C) containing the polyester resin (A'-1) and the vinyl resin (B-2) was removed. '-1) was obtained.

<Comparative Example 2> [Production of toner binder (C'-2)]
700 parts of a polyester resin (A-1) in an autoclave, 105 parts of styrene as a monomer constituting the vinyl resin (B'-1), 105 parts of butyl acrylate, 90 parts of acrylonitrile, and as a radical polymerization initiator (c) After 3 parts of t-butylperoxy-2-ethylhexanoate were charged and the atmosphere was replaced with nitrogen, the mixture was uniformly stirred at 70 ° C, and the temperature was raised to 120 ° C in a sealed state. After the polymerization was completed by keeping the temperature at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C) containing the polyester resin (A-1) and the vinyl resin (B'-1) was removed. '-2) was obtained.

<Comparative Example 3> [Production of toner binder (C'-3)]
In an autoclave, 700 parts of the polyester resin (A-1), 93 parts of styrene as a monomer constituting the vinyl resin (B'-2), 93 parts of butyl acrylate, 81 parts of acrylonitrile, 33 parts of trimethylolpropane triacrylate, As a radical polymerization initiator (c), 3 parts of t-butylperoxy-2-ethylhexanoate were charged, and after substituting with nitrogen, the mixture was uniformly stirred at 70 ° C, and heated to 120 ° C in a sealed state. After the polymerization was completed at the same temperature for 3 hours, the pressure was reduced from 0.5 to 2.5 kPa for 3 hours, and the toner binder (C) containing the polyester resin (A-1) and the vinyl resin (B'-2) was removed. '-3) was obtained.

  The toner binder (C′-1) does not contain an ethylene oxide adduct of an aromatic diol as the alcohol component (x) of the polyester resin, and (C′-2) and (C′-3) constitute the vinyl resin. The weight ratio of the monomer (a) is out of the range.

<Example 9> [Production of toner (T-1)]
For 85 parts of toner binder (C-1) according to Example 1, 8 parts of pigment carbon black [MA-100, manufactured by Mitsubishi Chemical Corporation], paraffin wax of release agent [Nippon Seiro Co., Ltd.] , HNP-9] and 2 parts of a charge control agent [T-77, manufactured by Hodogaya Chemical Industry Co., Ltd.], and formed into a toner by the following method.
First, the mixture was preliminarily mixed using a Henschel mixer [FM10B, manufactured by Nippon Coke Industry Co., Ltd.], and then kneaded with a twin-screw kneader [PCM-30, manufactured by Ikegai Co., Ltd.]. Then, after crushing finely using a supersonic jet crusher LabJet [KJ-25, manufactured by Kurimoto Iron Works, Ltd.], an elbow jet classifier [EJ-L-3 (LABO) type, manufactured by Matsubo Co., Ltd.] ] To obtain toner particles having a volume average particle diameter D50 of 6 μm.
Next, 1 part of colloidal silica [Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.] as a fluidizing agent was mixed with 100 parts of the toner particles in a sample mill to obtain a toner (T-1) according to Example 9.

<Examples 10 to 16> [Production of toners (T-2) to (T-8)]
Toners were manufactured in the same manner as in Example 9 using the number of parts of the raw materials described in Table 4, and toners (T-2) to (T-8) according to Examples 10 to 16 were obtained.

<Comparative Examples 4 to 6> [Production of Toners (T'-1) to (T'-3)]
Toners were manufactured in the same manner as in Example 9 with the number of parts of the raw materials described in Table 4, and toners (T′-1) to (T′-3) according to Comparative Examples 4 to 6 were obtained.

[Evaluation methods]
Hereinafter, the obtained toners (T-1) to (T-8) and (T'-1) to (T'-3) have low-temperature fixability, hot offset resistance, pulverizability, heat-resistant storage stability, and charging. A method for measuring and evaluating characteristics and durability will be described, including a criterion.

<Low temperature fixability>
The toner was uniformly placed on the paper surface at 1.00 mg / cm 2. At this time, as a method of placing the powder on the paper, a printer without a heat fixing machine was used.
This paper was passed through a soft roller at a fixing speed (peripheral speed of a heating roller) of 213 mm / sec and a temperature range of 100 to 200 ° C. of the heating roller at intervals of 5 ° C.
Next, the occurrence temperature of the cold offset (MFT) was measured by visually checking the presence or absence of a cold offset to the fixed image.
The lower the temperature at which the cold offset occurs, the better the low-temperature fixability.
Under these evaluation conditions, the MFT is generally preferably 135 ° C. or lower.

<Hot offset resistance>
In the same manner as the method described in the above low-temperature fixing property, the toner is placed on a paper surface, and the paper is fixed on a soft roller at a fixing speed (peripheral speed of a heating roller) of 213 mm / sec. The solution was passed at 5 ° C intervals.
Next, the occurrence of hot offset was measured by visually observing the presence or absence of hot offset to the fixed image.
The higher the temperature at which hot offset occurs, the better the hot offset resistance. Under these evaluation conditions, the temperature is preferably 180 ° C. or higher.

<Pulverizability>
For 85 parts of each toner binder used for toners (T-1) to (T-8) and (T'-1) to (T'-3), pigment carbon black [manufactured by Mitsubishi Chemical Corporation] , MA-100], 4 parts of carnauba wax as a release agent and 2 parts of a charge control agent [T-77, manufactured by Hodogaya Chemical Industry Co., Ltd.], Henschel mixer manufactured by Nippon Coke Industry Co., Ltd., FM10B , And the mixture obtained by kneading with a twin-screw kneader [Ikegai Co., Ltd., PCM-30] was cooled and then crushed and classified to a size of 8.6 mesh pass to 30 mesh on. The particles were used as particles for evaluation of crushability, and the particles for evaluation of crushability were finely pulverized by a supersonic jet crusher Labjet [KJ-25, manufactured by Kurimoto Iron Works, Ltd.] under the following conditions.
Grinding pressure: 0.64MPa
Grinding time: 15 minutes Separator frequency: 150 Hz
Adjuster ring: 15mm
Louver size: Medium As the particles for evaluating the pulverizability, finely pulverized materials were used without classification, and the volume average particle diameter (μm) was measured using a Coulter counter [trade name: Multisizer III (Beckman Coulter, Inc.) ))].
The smaller the volume average particle size, the better the pulverizability. Under these evaluation conditions, the thickness is preferably 8.0 μm or less.

<Heat-resistant storage stability>
1 g of the toner was placed in an airtight container, allowed to stand for 24 hours in an atmosphere at a temperature of 50 ° C. and a humidity of 50%, the degree of blocking was visually determined, and the heat resistance storage stability was evaluated according to the following criteria.

[Judgment criteria]
：: no blocking occurred at all, and excellent in heat-resistant storage stability.
Δ: Blocking occurred partly, and heat storage stability was poor.
×: Blocking occurred on the whole, and the heat storage stability was significantly poor.

<Charging characteristics>
0.5 g of the toner and 20 g of a ferrite carrier (F-150, manufactured by Powder Tech) were placed in a 50 mL glass bottle, and this was conditioned for 8 hours or more at 23 ° C. and 50% relative humidity. Thereafter, the mixture was friction-stirred with a Turbula shaker mixer at 50 rpm for 10 minutes and for 60 minutes, and the charge amount at each time was measured.
For the measurement, a blow-off charge amount measuring device [manufactured by Kyocera Chemical Co., Ltd.] was used.
(1) Charge amount after 10 minutes The “charge amount after 10 minutes of friction time” is defined as the charge amount after 10 minutes. A smaller value means that the negative chargeability is stronger and the initial charge amount is superior. Under these evaluation conditions, it is preferable that the value be −10 μC / g or less.
(2) Charging stability “Charging amount after 60 minutes of friction time / Charging amount after 10 minutes of friction time” was calculated, and this was defined as a charging stability index. The larger the charge stability index, the better the charge stability. Under this evaluation condition, it is preferable that it is 0.7 or more.

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

[Criteria]
A: There is no change in image quality even after copying 10,000 sheets, and no fogging occurs.
○: Fogging has occurred after 10,000 copies.
Δ: Fog occurred after 6,000 copies.
×: Fog occurred after 2,000 sheets were copied.

As is clear from the evaluation results in Table 4, all of the toners (T-1) to (T-8) according to Examples 9 to 16 exhibited excellent performance evaluation results.
On the other hand, the toners (T′-1) to (T′-3) according to Comparative Examples 4 to 6 had some poor performance items.

The toner binder and toner of the present invention are excellent in pulverizability, heat-resistant storage stability, charging characteristics and durability while maintaining low-temperature fixability and hot offset resistance, and are used for electrophotography, electrostatic recording, electrostatic printing, and the like. And can be suitably used as a toner binder and toner for developing an electrostatic image.
Further, it is suitable for use as an additive for paints, an additive for adhesives, and particles for electronic paper.

Claims (8)

  A toner binder containing a polyester resin (A) and a vinyl resin (B), wherein (A) is obtained by polycondensing a component containing an alcohol component (x) and a carboxylic acid component (y). A polyester resin, wherein (x) contains an ethylene oxide adduct of an aromatic diol, (B) contains a polyfunctional vinyl monomer (a) as a monomer, A toner binder wherein the weight ratio of (a) in the monomer is 0.1 to 10% by weight based on the total weight of the monomers.   The toner binder according to claim 1, wherein the polyester resin (A) is an amorphous saturated polyester resin. The toner binder according to claim 1, wherein the following relational expression (1) is satisfied.
Relational expression (1): | SP (A) -SP (B) | ≦ 1.3 (cal / cm ³ ) ^0.5
[In the relational expression (1), SP (A) is the solubility parameter (SP value) of the polyester resin (A), and SP (B) is the SP value of the vinyl resin (B). ] 4. The toner binder according to claim 1, wherein the vinyl resin (B) has a glass transition temperature (Tg _B ) of −35 to 47 ° C. 5. Difference in glass transition temperature (Tg _B) of the glass transition temperature of the polyester resin _(A) (Tg A) and the vinyl resin _{(B) [(Tg A)} - (Tg B)] is claim 1 is 15 ℃ or higher 5. The toner binder according to any one of 4.   The toner binder according to any one of claims 1 to 5, wherein the polyester resin (A) has a peak top molecular weight (Mp) of 3,000 to 10,000 in gel permeation chromatography (GPC).   The toner binder according to any one of claims 1 to 6, wherein the weight ratio [(A) / (B)] of the polyester resin (A) and the vinyl resin (B) is 50/50 to 90/10. A toner containing the toner binder according to claim 1.