Toner binder manufacturing method

Abstract

To provide a toner binder with superior dispersibility, low-temperature fixability, changeability, heat-resistant storage stability, and image intensity.SOLUTION: A toner binder manufacturing method is provided, comprising transesterifying an amorphous vinyl resin (A) containing an alkyl (meth)acrylate having 4 to 9 carbon atoms as a constituent monomer and a monovalent alcohol (B) having 18 to 30 carbon atoms. Preferably the toner binder manufacturing method also comprises reducing the pressure inside a reaction system during and / or after the transesterification.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a toner binder. [Background technology]

[0002] In recent years, along with the promotion of miniaturization, speedup, and higher image quality of electrophotographic devices, there has been a strong demand for improving the low-temperature fixability of toners from the viewpoint of energy conservation, i.e., reducing energy consumption in the fixing process. However, generally, when an attempt is made to improve low-temperature fixability, heat-resistant storage stability is reduced, and vice versa. Therefore, there is a trade-off between low-temperature fixability and heat-resistant storage stability, and there is a demand for the development of a toner binder that can achieve both low-temperature fixability and heat-resistant storage stability. For example, in order to achieve both low-temperature fixability and heat-resistant storage stability, a toner composition containing a toner binder has been proposed that uses a combination of an amorphous resin and a crystalline resin as a binder resin, thereby improving low-temperature fixability while maintaining heat-resistant storage stability due to the melting properties of the crystalline resin (see Patent Documents 1 and 2). However, in the method for producing a toner binder using the above-mentioned crystalline resin, the crystalline monomer or the synthetic raw material of the crystalline monomer remains in the toner binder at a certain concentration range, and therefore the long-term stability and document offset resistance after continuous printing are not sufficient, and improvements in these areas are desired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-77930 [Patent Document 2] Japanese Patent Application Publication No. 2019-211763 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a toner binder that is excellent in low-temperature fixability, heat-resistant storage stability under high-temperature and high-humidity conditions, long-term stability, document offset resistance after continuous printing, and charging stability.

[0005] The present inventors have conducted extensive research to solve these problems and have arrived at the present invention. That is, the present invention provides a method for producing a toner binder, which comprises a step of transesterifying an amorphous vinyl resin (A) containing an alkyl(meth)acrylate having 4 to 9 carbon atoms as a constituent monomer with a monohydric alcohol (B) having 18 to 30 carbon atoms. [Effects of the Invention]

[0006] The present invention makes it possible to provide a toner binder that is excellent in low-temperature fixability, heat-resistant storage stability under high temperature and humidity conditions, long-term stability, document offset resistance after continuous printing, and charging stability. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention will be described in detail below.

[0008] The method for producing a toner binder of the present invention includes a step of transesterifying an amorphous vinyl resin (A) containing an alkyl(meth)acrylate having 4 to 9 carbon atoms as a constituent monomer with a monohydric alcohol (B) having 18 to 30 carbon atoms. The method for producing the toner binder of the present invention will be explained below in order.

[0009] The toner binder manufacturing method of the present invention includes a step of transesterifying an amorphous vinyl resin (A) with a monohydric alcohol (B) having 18 to 30 carbon atoms, thereby producing a toner binder in which an alkyl group having 18 to 30 carbon atoms is bonded to the side chain of the amorphous vinyl resin (A). Compared to when a crystalline vinyl resin containing a monomer having an alkyl group having 18 to 30 carbon atoms is used as a constituent monomer, the toner binder can reduce the amount of unreacted monomer remaining and incorporate the alkyl group having 18 to 30 carbon atoms relatively uniformly into the side chain, thereby improving the performance (particularly long-term stability and document offset resistance after continuous printing) of a toner using the toner binder obtained by this manufacturing method. In the present invention, "crystalline" means that in differential scanning calorimetry (also referred to as DSC measurement), the DSC curve has an endothermic peak top temperature (Tm). In addition, in the present invention, "amorphous" means that when the transition temperature of a sample is measured using a differential scanning calorimeter, there is no endothermic peak top temperature. The method for measuring the peak top temperature (Tm) of the endothermic peak is described below. Measurement is performed using a differential scanning calorimeter (e.g., DSC Q20, manufactured by TA Instruments, Inc.). The sample is first heated from 30°C to 180°C at 10°C / min, then cooled from 180°C to 0°C at 10°C / min, and then heated a second time from 0°C to 180°C at 10°C / min. The top temperature of the endothermic peak during the second heating process is taken as the peak top temperature (Tm) of the endothermic peak.

[0010] [Amorphous vinyl resin (A)] The amorphous vinyl resin (A) is a polymer containing an alkyl (meth)acrylate having 4 to 9 carbon atoms as a constituent monomer, and is an amorphous vinyl resin. In the present invention, "(meth)acrylate" means acrylate and / or methacrylate.

[0011] Examples of alkyl(meth)acrylates having 4 to 9 carbon atoms include alkyl(meth)acrylates having a linear alkyl group and alkyl(meth)acrylates having a branched alkyl group. One type of alkyl(meth)acrylate having 4 to 9 carbon atoms may be used alone, or two or more types may be used in combination. Examples of alkyl (meth)acrylates having a linear alkyl group include methyl (meth)acrylate [methyl (meth)acrylate], ethyl (meth)acrylate [ethyl (meth)acrylate], propyl (meth)acrylate [propyl (meth)acrylate], butyl (meth)acrylate [butyl (meth)acrylate], pentyl (meth)acrylate [pentyl (meth)acrylate], and hexyl acrylate [hexyl acrylate]. Examples of alkyl(meth)acrylates having a branched alkyl group include isopropyl(meth)acrylate and isobutyl(meth)acrylate. In the present invention, "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid".

[0012] Of these, from the viewpoint of ease of progression of the transesterification reaction, preferred are alkyl (meth)acrylates having a linear alkyl group, more preferred are methyl (meth)acrylate [methyl (meth)acrylate], ethyl (meth)acrylate [ethyl (meth)acrylate], propyl (meth)acrylate [propyl (meth)acrylate], and butyl (meth)acrylate [butyl (meth)acrylate], and even more preferred is butyl (meth)acrylate [butyl (meth)acrylate].

[0013] The amorphous vinyl resin (A) may be used in combination with other monomers as needed, and examples thereof include monomers (c) other than alkyl (meth)acrylates having 4 to 9 carbon atoms. The monomer (c) may be used alone or in combination of two or more kinds. Examples of the monomer (c) include vinyl hydrocarbons (c1), carboxyl group-containing vinyl monomers (c2), hydroxyl group-containing vinyl monomers (c3), nitrogen-containing vinyl monomers (c4), epoxy group-containing vinyl monomers (c5), halogen-containing vinyl monomers (c6), and other ester monomers (c7).

[0014] Examples of the vinyl hydrocarbon (c1) include aliphatic vinyl hydrocarbons, alicyclic vinyl hydrocarbons, and aromatic vinyl hydrocarbons. Aliphatic vinyl hydrocarbons include alkenes and alkadienes. Specific examples of alkenes include ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, and α-olefins other than those mentioned above. Specific examples of alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene, and 1,7-octadiene. Alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, and specific examples thereof include cyclohexene, (di)cyclopentadiene, vinylcyclohexene, ethylidenebicycloheptene, and terpenes (pinene, limonene, indene, etc.). Examples of aromatic vinyl hydrocarbons include styrene and its hydrocarbyl (alkyl, cycloalkyl, aralkyl and / or alkenyl) substituted derivatives, and specific examples include α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, benzylstyrene, crotylbenzene, divinylbenzene, divinyltoluene, divinylxylene, trivinylbenzene, and vinylnaphthalene.

[0015] Examples of the carboxyl group-containing vinyl monomer (c2) include unsaturated monocarboxylic acids and unsaturated dicarboxylic acids having 3 to 20 carbon atoms, and anhydrides thereof. Specific examples include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, (anhydride) maleic acid, maleic acid monoalkyl esters, fumaric acid, fumaric acid monoalkyl esters, crotonic acid, itaconic acid, itaconic acid monoalkyl esters, itaconic acid glycol monoether, citraconic acid, citraconic acid monoalkyl esters, and cinnamic acid.

[0016] Examples of the hydroxyl group-containing vinyl monomer (c3) include hydroxystyrene, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylate (e.g., 2-hydroxyethyl acrylate), hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethyl propenyl ether, and sucrose allyl ether.

[0017] Examples of the nitrogen-containing vinyl monomer (c4) include amino group-containing vinyl monomers, amide group-containing vinyl monomers, nitrile group-containing vinyl monomers, quaternary ammonium cation group-containing vinyl monomers, and nitro group-containing vinyl monomers. Examples of amino group-containing vinyl monomers include aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, t-butylaminoethyl methacrylate, N-aminoethyl (meth)acrylamide, (meth)allylamine, morpholinoethyl (meth)acrylate, 4-vinylpyridine, 2-vinylpyridine, crotylamine, N,N-dimethylaminostyrene, methyl α-acetaminoacrylate, vinylimidazole, N-vinylpyrrole, N-vinylthiopyrrolidone, N-arylphenylenediamine, aminocarbazole, aminothiazole, aminoindole, aminopyrrole, aminoimidazole, aminomercaptothiazole, and salts thereof. Examples of the amide group-containing vinyl monomer include (meth)acrylamide, N-methyl(meth)acrylamide, N-butylacrylamide, diacetone acrylamide, N-methylol(meth)acrylamide, N,N'-methylene-bis(meth)acrylamide, N,N-dimethylacrylamide, methacrylformamide, N-methyl-N-vinylacetamide, N-vinyl-2-pyrrolidone, N-vinylpiperidone, and N-vinylcaprolactam. Examples of the nitrile group-containing vinyl monomer include acrylonitrile, methacrylonitrile, cyanostyrene, and cyanoacrylate. Examples of the quaternary ammonium cation group-containing vinyl monomer include quaternized products of tertiary amine group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and diallylamine (which are quaternized using a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, or dimethyl carbonate). Nitro group-containing vinyl monomers include nitrostyrene.

[0018] Examples of the epoxy group-containing vinyl monomer (c5) include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenyl phenyl oxide.

[0019] Examples of the halogen-containing vinyl monomer (c6) include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

[0020] Examples of other ester monomers (c7) include alkyl (meth)acrylates having 10 to 40 carbon atoms [heptyl (meth)acrylate [heptyl (meth)acrylate], octyl (meth)acrylate [octyl (meth)acrylate], 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate [docosyl (meth)acrylate], lignoceryl (meth)acrylate, ceryl (meth)acrylate, montanyl (meth)acrylate, triacontyl (meth)acrylate, and dotriacontyl (meth)acrylate, etc.], alkylene ether (meth)acrylates having 5 to 30 carbon atoms, vinyl esters [methoxy-triethylene glycol acrylate, ethoxy-diethylene glycol acrylate, methoxy-polyethylene glycol acrylate, methoxydipropylene glycol acrylate, and the like], polyfunctional (meth)acrylates [poly(meth)acrylates of polyhydric alcohols such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and polyethylene glycol di(meth)acrylate, and the like], aliphatic vinyl esters having 4 to 15 carbon atoms and aromatic vinyl esters having 9 to 15 carbon atoms [vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, methyl-4-vinylbenzoate, and the like].

[0021] Among these monomers (c), vinyl hydrocarbons (c1) and nitrogen-containing vinyl monomers (c4) are preferred from the viewpoint of long-term stability and charging stability, and aromatic vinyl hydrocarbons, nitrile group-containing vinyl monomers, and amide group-containing vinyl monomers are more preferred.

[0022] From the viewpoints of low-temperature fixability, heat-resistant storage stability under high temperature and high humidity conditions, long-term stability, and document offset resistance after continuous printing, the amorphous vinyl resin (A) preferably contains 30 to 95 wt % of alkyl (meth)acrylate having 4 to 9 carbon atoms as a constituent monomer, based on the weight of all constituent monomers of the amorphous vinyl resin (A), and more preferably 45 to 65 wt %. When the weight proportion of alkyl (meth)acrylate having 4 to 9 carbon atoms is 30 wt % or more, low-temperature fixability and heat-resistant storage stability under high temperature and high humidity conditions are improved. On the other hand, when the weight proportion of alkyl (meth)acrylate having 4 to 9 carbon atoms is 95 wt % or less, long-term stability and document offset resistance after continuous printing are improved.

[0023] When the amorphous vinyl resin (A) contains other monomers as constituent monomers, the content thereof is preferably 5 to 70% by weight, more preferably 35 to 55% by weight, based on the weight of all constituent monomers of the amorphous vinyl resin (A).

[0024] The amorphous vinyl resin (A) can be produced by polymerizing a monomer composition by a known method (e.g., radical polymerization, anionic polymerization, cationic polymerization, living radical polymerization, living anionic polymerization, living cationic polymerization, etc.). In the case of radical polymerization, the resin can be synthesized by, for example, a solution polymerization method (e.g., JP-A-5-117330) in which the monomer is reacted with a radical reaction initiator (d) in a solvent (e.g., toluene). The radical reaction initiator may be a known radical reaction initiator (d). The radical reaction initiator (d) 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.

[0025] The inorganic peroxide (d1) is not particularly limited, but examples thereof include hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

[0026] The organic peroxide (d2) is not particularly limited, and 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, octaninol peroxide, decanolyl peroxide, Examples of peroxyalkylene compounds include lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, cumyl peroxyneodecanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl monocarbonate, and t-butyl peroxyacetate.

[0027] 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, 2,2'-azobis(2-methylbutyronitrile), and azobisisobutyronitrile.

[0028] The weight average molecular weight of the amorphous vinyl resin (A) in the present invention, as measured by gel permeation chromatography (GPC), is preferably 2,000 to 200,000, more preferably 5,000 to 100,000, even more preferably 10,000 to 70,000, and particularly preferably 18,000 to 52,000, from the viewpoints of low-temperature fixability and document offset resistance after continuous printing.

[0029] In the present invention, the number average molecular weight (hereinafter sometimes abbreviated as Mn) and weight average molecular weight (hereinafter sometimes abbreviated as Mw) of the crystalline vinyl resin (A) can be measured using GPC under the following conditions. Device (example): HLC-8120 [manufactured by Tosoh Corporation] Column (example): 2 TSK GEL GMH6 [Tosoh Corporation] Measurement temperature: 40℃ Sample solution: 0.25 wt% THF solution Mobile phase: Tetrahydrofuran (containing no polymerization inhibitor) Solution injection volume: 100μL Detector: Refractive index detector Reference material: 12 standard polystyrenes (TSK standard POLYSTYRENE) (molecular weights: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation] For measuring the molecular weight, a sample is dissolved in tetrahydrofuran (hereinafter abbreviated as THF) to a concentration of 0.25% by weight, and the insoluble matter is filtered off using a glass filter to obtain a sample solution. It should be noted that for the toner binder described later, Mn and Mw can be determined in the same manner as above.

[0030] The glass transition temperature (Tg) of the amorphous vinyl resin (A) in the present invention, from the viewpoints of low-temperature fixability and heat-resistant storage stability under high-temperature and high-humidity conditions, is preferably −20 to 80° C., more preferably −10 to 70° C., and even more preferably −5 to 60° C. The glass transition temperature can be measured by the method specified in ASTM D3418-82 (DSC method) using, for example, a DSC Q20 manufactured by TA Instruments Corporation.

[0031] [Monohydric alcohols (B) with 18 to 30 carbon atoms] The monohydric alcohol (B) having 18 to 30 carbon atoms is not particularly limited as long as it has 18 to 30 carbon atoms and one hydroxyl group. The alcohol may be any of primary, secondary, and tertiary alcohols, but from the viewpoint of reactivity, primary alcohols are preferred. The monohydric alcohol (B) having 18 to 30 carbon atoms may be used alone or in combination of two or more kinds.

[0032] Examples of the monohydric alcohol (B) having 18 to 30 carbon atoms include monohydric alcohols having a linear alkyl group and monohydric alcohols having a branched alkyl group. Examples of monohydric alcohols having a linear alkyl group include 1-octadecanol (stearyl alcohol), 1-nonadecanol, 1-icosanol, 1-heneicosanol, 1-docosanol (behenyl alcohol), 1-tetracosanol, and 1-triacontanol. Examples of monohydric alcohols having a branched alkyl group include 2-decyl-1-tetradecanol.

[0033] Of these monohydric alcohols (B) having 18 to 30 carbon atoms, preferred are monohydric alcohols having a linear alkyl group, more preferred are monohydric alcohols having a linear alkyl group having 18 to 24 carbon atoms, and even more preferred is 1-docosanol (behenyl alcohol). If a monohydric alcohol having less than 18 carbon atoms is used, the heat-resistant storage stability under high temperature and humidity conditions may be deteriorated, and if a monohydric alcohol having more than 30 carbon atoms is used, the long-term stability may be deteriorated.

[0034] [Transesterification] The transesterification reaction in the production method of the present invention is not particularly limited as long as it is a reaction in which an ester group moiety of an amorphous vinyl resin (A) containing an alkyl(meth)acrylate having 4 to 9 carbon atoms as a constituent monomer is exchanged with a hydroxyl group moiety of a monohydric alcohol (B) having 18 to 30 carbon atoms. Examples of the transesterification reaction include a method in which a monomer composition (A0) containing an alkyl(meth)acrylate having 4 to 9 carbon atoms, which is a constituent monomer of the amorphous vinyl resin (A), is mixed in advance with the monohydric alcohol (B) having 18 to 30 carbon atoms, and the transesterification reaction is carried out while obtaining the amorphous vinyl resin (A) in the presence of the monohydric alcohol (B) having 18 to 30 carbon atoms; and a method in which a monomer composition (A0) containing an alkyl(meth)acrylate having 4 to 9 carbon atoms is polymerized to obtain the amorphous vinyl resin (A), and then the amorphous vinyl resin (A) is mixed with the monohydric alcohol (B) having 18 to 30 carbon atoms to perform the transesterification.

[0035] The transesterification reaction can be carried out in a sealed vessel at a temperature of preferably 120 to 280° C., more preferably 130 to 230° C., and even more preferably 140 to 180° C. The reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours, from the viewpoint of ensuring that the transesterification reaction is carried out reliably. From the viewpoint of reactivity, it is also preferable to have a step of reducing the pressure in the reaction system during and / or after the transesterification reaction, and the degree of reduction is preferably 20 kPa or less, more preferably 15 kPa or less, even more preferably 10 kPa or less, and particularly preferably 5 kPa or less. From the viewpoints of low-temperature fixability and heat-resistant storage stability under high temperature and high humidity, the transesterification reaction rate is preferably 90% or more, more preferably 95%, and particularly preferably 97% or more. The transesterification reaction rate can be determined by measuring the content of the monohydric alcohol (B) having 18 to 30 carbon atoms before and after the reaction.

[0036] In this case, an esterification catalyst can be used if necessary. Examples of the esterification catalyst include tin-containing catalysts (e.g., dibutyltin oxide), antimony trioxide, titanium-containing catalysts (e.g., titanium alkoxide, potassium oxalate titanate, titanium terephthalate, titanium terephthalate alkoxide, the catalysts described in JP-A-2006-243715 (titanium diisopropoxybistriethanolaminate, titanium dihydroxybistriethanolaminate, titanium monohydroxytristriethanolaminate, titanyl bistriethanolaminate, and intramolecular polycondensates thereof), and the catalysts described in JP-A-2007-11307 (titanium tributoxyterephthalate, titanium triisopropoxyterephthalate, titanium diisopropoxyditerephthalate), etc.), zirconium-containing catalysts (e.g., zirconyl acetate), and zinc acetate. Among the esterification catalysts, titanium-containing catalysts are preferred from the viewpoint of reaction efficiency, and titanium alkoxides are more preferred.

[0037] The weight ratio of the amorphous vinyl resin (A) to the monohydric alcohol (B) having 18 to 30 carbon atoms [(A):(B)] before the transesterification reaction is preferably 35:65 to 70:30, more preferably 40:60 to 60:40, from the viewpoints of low-temperature fixability, heat-resistant storage stability under high-temperature and high-humidity conditions, long-term stability, and charging stability. The weight ratio of the alkyl (meth)acrylate having 4 to 9 carbon atoms, which is a constituent of the amorphous vinyl resin (A), to the monohydric alcohol (B) having 18 to 30 carbon atoms [(meth)acrylate):(B)] before the transesterification reaction is preferably 25:75 to 45:55, more preferably 30:70 to 40:60, from the viewpoints of low-temperature fixability, heat-resistant storage stability under high-temperature and high-humidity conditions, long-term stability, and charging stability.

[0038] [Toner binder] The toner binder obtained by the present invention preferably has at least one endothermic peak top temperature (Tm) in the range of 45 to 100°C. When Tm is in this range, the toner binder has a good balance between low-temperature fixability and heat-resistant storage stability under high-temperature and high-humidity conditions. Tm is more preferably 50 to 90°C. The endothermic peak top temperature (Tm) of the toner binder can be adjusted by the type and composition ratio of the monomers constituting the crystalline vinyl resin (for example, by adjusting the carbon number of the alcohol (B) substituting the alkyl group of the alkyl (meth)acrylate having 4 to 9 carbon atoms constituting the crystalline vinyl resin, or by adjusting the weight ratio of the alcohol (B) constituting the crystalline vinyl resin), weight average molecular weight, etc. For example, the endothermic peak top temperature of the toner binder can be increased by increasing the carbon number of the alcohol (B) or increasing the weight ratio of the alcohol (B) having a high carbon number. The peak top temperature (Tm) of the endothermic peak is measured using a differential scanning calorimeter (e.g., DSC Q20 manufactured by TA Instruments), and is the peak top temperature of the endothermic peak during the second heating process when the toner binder is first heated from 20°C to 150°C at 10°C / min, then cooled to 0°C at 10°C / min, and then heated a second time from 0°C to 150°C at 10°C / min.

[0039] The weight average molecular weight (Mw) of the toner binder obtained by the present invention is preferably 5,000 to 200,000, more preferably 10,000 to 200,000, even more preferably 30,000 to 200,000, and particularly preferably 35,000 to 150,000, from the viewpoint of achieving both hot offset resistance of the toner and document offset resistance after continuous printing. The weight average molecular weight of the toner binder can be measured by the same method and conditions as those for the crystalline vinyl resin (A).

[0040] The content of the unreacted monohydric alcohol (B) having 18 to 30 carbon atoms and the alcohol having 4 to 9 carbon atoms generated by the reaction in the toner binder is preferably 6% by weight or less, more preferably 3% by weight or less, and even more preferably 2% by weight or less, from the viewpoints of low-temperature fixability and heat-resistant storage stability under high-temperature and high-humidity conditions.

[0041] [toner] The toner binder obtained by the production method of the present invention can be used as a material for toner. When producing a toner using the toner binder obtained by the production method of the present invention, one or more known additives selected from colorants, release agents, charge control agents, fluidizing agents, etc. may be used as needed in addition to the toner binder.

[0042] As the colorant, all dyes and pigments used as toner colorants can be used. Examples include 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, and Oil Pink OP. These colorants may be used alone or in combination of two or more. If necessary, magnetic powder (powder of ferromagnetic metals such as iron, cobalt, and nickel, or compounds such as magnetite, hematite, and ferrite) can be added to function as a colorant.

[0043] For the release agent, the flow softening point (T 1 / 2] is preferably 50 to 170°C, and examples thereof include aliphatic hydrocarbon waxes such as polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and 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.

[0044] Flow softening point (T 1 / 2 The measurement method for [ is described below. Using a constant test force extrusion capillary rheometer flow tester (e.g., CFT-500D, manufactured by Shimadzu Corporation), 1 g of the test sample is heated at a temperature increase rate of 6°C / min. At this time, a load of 1.96 MPa is applied by the plunger, and the sample is extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. A graph of "plunger depression (flow value)" versus "temperature" is plotted, and the temperature corresponding to half of the maximum plunger depression is taken as the flow softening point (T 1 / 2 〕

[0045] Examples of polyolefin waxes include (co)polymers of olefins (such as 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 thereof] (such as low-molecular-weight polypropylene, low-molecular-weight polyethylene, and low-molecular-weight polypropylene-polyethylene copolymers), oxides of olefin (co)polymers with oxygen and / or ozone, maleic acid-modified olefin (co)polymers [for example, modified products of maleic acid and its derivatives (maleic anhydride, monomethyl maleate, monobutyl maleate, dimethyl maleate, etc.)], and copolymers of olefins with unsaturated carboxylic acids [(meth)acrylic acid, itaconic acid, maleic anhydride, etc.] and / or unsaturated carboxylic acid alkyl esters [(meth)acrylic acid alkyl (C1 to C18) esters and alkyl maleate (C1 to C18) esters, etc.].

[0046] 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.

[0047] 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, all manufactured by Nippon Seiro Co., Ltd.

[0048] Examples of Fischer-Tropsch wax include Sasolwax C80 manufactured by Sasol Corporation and FT-0070 manufactured by Nippon Seiro Co., Ltd.

[0049] Examples of carnauba wax include refined carnauba wax special No. 1 manufactured by Kato Yoko Co., Ltd.

[0050] Examples of ester waxes include fatty acid ester waxes (for example, Nissan Electol WEP-2, WEP-3, WEP-4, WEP-5, and WEP-8 manufactured by NOF Corporation).

[0051] The higher alcohols include aliphatic alcohols having 30 to 50 carbon atoms, such as triacontanol, and the fatty acids include fatty acids having 30 to 50 carbon atoms, such as triacontancarboxylic acid.

[0052] Examples of fatty acid amides include Diamid Y and Diamid 200 manufactured by Mitsubishi Chemical Corporation.

[0053] The charge control agent may be either a positively chargeable charge control agent or a negatively chargeable charge control agent, and examples thereof include nigrosine dyes, triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salts, polyamine resins, imidazole derivatives, quaternary ammonium base-containing polymers, metal-containing azo dyes, copper phthalocyanine dyes, salicylic acid metal salts, boron complexes of benzilic acid, sulfonic acid group-containing polymers, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers.

[0054] 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.

[0055] The content of the toner binder in the toner is preferably 30 to 97% by weight, more preferably 40 to 95% by weight, and even more preferably 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 release agent is preferably 0 to 30% by weight, more preferably 0.5 to 20% by weight, and even more 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 the additives is preferably 3 to 70% by weight, more preferably 4 to 58% by weight, and even more preferably 5 to 50% by weight, based on the toner weight.

[0056] The toner containing the toner binder obtained by the present invention may be obtained by any known method such as a kneading and pulverization method, an emulsion phase inversion method, an emulsion polymerization method, a suspension polymerization method, a solution 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, excluding the fluidizing agent, are dry-blended using a Henschel mixer, Nauta mixer, Banbury mixer, or the like, and then melt-kneaded using a continuous mixing device such as a twin-screw kneader, extruder, continuous kneader, or three-roll mill, and then coarsely pulverized using a mill or the like, and finally micronized using an airflow 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 with a volume average particle size (D50) of 5 to 20 μm], and then the fluidizing agent can be mixed to produce the toner.

[0057] 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 aqueous electrolyte solution, ISOTON-II (Beckman Coulter). 2 to 20 mg of the sample to be measured is then added, and the suspended electrolyte is dispersed in an ultrasonic disperser for approximately 1 to 3 minutes. The volume and number of toner particles are measured using a 50 μm aperture, and the volume and number distributions are calculated. From the resulting distributions, 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 determined.

[0058] In addition, when a toner is obtained by an emulsion phase inversion method, the components constituting the toner except for the fluidizing agent are dissolved or dispersed in an organic solvent, and then emulsified by adding water or the like, followed by separation and classification. The volume average particle size of the toner is preferably 3 to 15 μm. The toner containing the toner binder obtained by the production method of the present invention is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite coated with resin (acrylic resin, silicone resin, etc.) as needed, and used as a developer for electric latent images. When carrier particles are used, the weight ratio of toner to carrier particles is preferably 1 / 99 to 99 / 1. Alternatively, an electric latent image can be formed by friction with a member such as a charging blade instead of carrier particles. The toner containing the toner binder obtained by the production method of the present invention may be in an embodiment that does not contain carrier particles.

[0059] The toner containing the toner binder obtained by the production method of the present invention is fixed to a support (paper, polyester film, etc.) by a copier, printer, etc. to form a recording material. As a method for fixing to a support, a known heat roll fixing method, flash fixing method, etc. can be applied.

[0060] The toner produced using the toner binder obtained by the production method 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 particularly suitable for full color applications. [Example]

[0061] The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, "parts" below refer to parts by weight.

[0062] <Production Example 1> [Production of amorphous vinyl resin (A-1)] 235.0 parts of xylene was charged into an autoclave, which was then heated to 135°C under a sealed condition with stirring. The pressure was released, and the temperature was then raised to 155°C under a sealed condition with stirring. A mixed solution of 150.0 parts of styrene, 450.0 parts of butyl acrylate, 150.0 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 155°C, allowing polymerization to occur. After the dropwise addition, the drip line was washed with 15.0 parts of xylene. The mixture was then maintained at the same temperature for 2.2 hours, cooled to 70°C, and the reaction rate of the butyl acrylate was confirmed. Since the reaction rate of the butyl acrylate was less than 98%, an additional 1.9 parts of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, yielding vinyl resin (A-1).

[0063] <Production Example 2> [Production of amorphous vinyl resin (A-2)] 235.0 parts of xylene were charged into an autoclave, which was then heated to 135°C while sealed and stirred. The pressure was released, and the temperature was then raised to 170°C while sealed and stirred. A mixed solution of 62.3 parts of styrene, 375.0 parts of butyl acrylate, 187.5 parts of N-vinyl-2-pyrrolidone, 125.3 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 170°C, allowing polymerization to occur. After the addition, the drip line was washed with 15.0 parts of xylene. After maintaining the same temperature for another 0.5 hours, the mixture was cooled to 70°C and the reaction rate of butyl acrylate was confirmed. Since the reaction rate of butyl acrylate was less than 98%, 1.9 parts of di-t-butyl peroxide was added and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170° C. for 3 hours under a reduced pressure of 0.5 to 2.5 kPa to obtain a vinyl resin (A-2).

[0064] <Production Example 3> [Production of amorphous vinyl resin (A-3)] An autoclave was charged with 235.0 parts of xylene and heated to 135°C under agitation in a sealed container. The pressure was released, and the temperature was then increased to 170°C under agitation in a sealed container. A mixed solution of 300.0 parts of styrene, 450.0 parts of butyl acrylate, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 150°C, allowing polymerization to occur. After the addition, the drip line was washed with 15.0 parts of xylene. The mixture was then maintained at the same temperature for 2.6 hours, cooled to 70°C, and the reaction rate of the butyl acrylate was confirmed. Since the reaction rate of the butyl acrylate was less than 98%, an additional 1.9 parts of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, yielding vinyl resin (A-3).

[0065] <Production Example 4> [Production of amorphous vinyl resin (A-4)] An autoclave was charged with 235.0 parts of xylene and heated to 135°C under agitation in a sealed container. The pressure was released, and the temperature was then increased to 170°C under agitation in a sealed container. A mixed solution of 172.5 parts of styrene, 337.5 parts of methyl acrylate, 240.0 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 170°C, allowing polymerization to occur. After the dropwise addition, the drip line was washed with 15.0 parts of xylene. The mixture was then held at the same temperature for another 0.5 hours, cooled to 70°C, and the reaction rate of methyl acrylate was confirmed. Since the reaction rate of methyl acrylate was less than 98%, an additional 1.9 parts of di-t-butyl peroxide was added and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, yielding vinyl resin (A-4).

[0066] <Production Example 5> [Production of amorphous vinyl resin (A-5)] 235.0 parts of xylene was charged into an autoclave, which was then heated to 135°C under agitation and sealed. The pressure was released, and the temperature was then raised to 170°C under agitation and sealed. A mixed solution of 157.9 parts of styrene, 434.2 parts of butyl acrylate, 157.9 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 170°C, allowing polymerization to occur. After the dropwise addition, the drip line was washed with 15.0 parts of xylene. The mixture was then held at the same temperature for another 0.5 hours, cooled to 70°C, and the reaction rate of the butyl acrylate was confirmed. Since the reaction rate of the butyl acrylate was less than 98%, an additional 1.9 parts of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, yielding vinyl resin (A-5).

[0067] <Production Example 6> [Production of amorphous vinyl resin (A-6)] 235.0 parts of xylene was charged into an autoclave, which was then heated to 135°C under agitation and sealed. The pressure was released, and the temperature was then raised to 170°C under agitation and sealed. A mixed solution of 100.0 parts of styrene, 500.0 parts of hexyl acrylate, 150.0 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 170°C, allowing polymerization to occur. After the dropwise addition, the drip line was washed with 15.0 parts of xylene. The mixture was then held at the same temperature for another 0.5 hours, cooled to 70°C, and the reaction rate of the hexyl acrylate was confirmed. Since the reaction rate of the hexyl acrylate was less than 98%, 1.9 parts of di-t-butyl peroxide was added and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, yielding vinyl resin (A-6).

[0068] <Comparative Production Example 1> [Production of Amorphous Vinyl Resin (A'-1)] An autoclave was charged with 235.0 parts of xylene and heated to 135°C under a sealed condition with stirring. The pressure was released, and the temperature was then raised to 170°C under a sealed condition with stirring. A mixed solution of 120.0 parts of styrene, 520.0 parts of octyl acrylate, 110.0 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was added dropwise over 3 hours while controlling the temperature inside the autoclave to 170°C, allowing polymerization to occur. After the dropwise addition, the drip line was washed with 15.0 parts of xylene. The mixture was then held at the same temperature for another 0.5 hours, cooled to 70°C, and the reaction rate of the octyl acrylate was confirmed. Since the reaction rate of the octyl acrylate was less than 98%, an additional 1.9 parts of di-t-butyl peroxide was added, and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa, yielding vinyl resin (A'-1).

[0069] <Comparative Production Example 2> [Production of Crystalline Vinyl Resin (A'-2)] 235.0 parts of xylene were charged into an autoclave, and the temperature was increased to 135°C while stirring and sealed. The pressure was released, and the temperature was then increased to 150°C while stirring and sealed. A mixed solution of 534.0 parts of docosyl acrylate, 83.3 parts of styrene, 49.5 parts of butyl acrylate, 83.3 parts of acrylonitrile, and 1.5 parts of di-t-butyl peroxide was adjusted to 60°C. The autoclave temperature was controlled to 150°C, and the mixture was added dropwise over 3 hours to polymerize. After addition, the drip line was washed with 15.0 parts of xylene. The mixture was then maintained at the same temperature for 3.7 hours, cooled to 70°C, and the reaction rate of butyl acrylate was confirmed. Since the reaction rate of butyl acrylate was less than 98%, 1.5 parts of di-t-butyl peroxide was added and the reaction was continued until the reaction rate reached 98% or higher. The solvent was removed at 170°C for 3 hours under a reduced pressure of 0.5 to 2.5 kPa to obtain crystalline vinyl resin (A'-2). The endothermic peak top temperature (Tm) of the crystalline vinyl resin (A'-2) was 61°C and the weight average molecular weight (Mw) was 70,000.

[0070] The compositions and physical properties of the amorphous vinyl resins (A-1) to (A-6) obtained in Production Examples 1 to 6, the amorphous vinyl resin (A'-1) obtained in Comparative Production Example 1, and the crystalline vinyl resin (A'-2) obtained in Comparative Production Example 2 are shown in Table 1. None of the amorphous vinyl resins (A-1) to (A-6) and (A'-1) had a peak top temperature (Tm) of the endothermic peak.

[0071] [Table 1]

[0072] Example 1 [Production of Toner Binder (C-1)] A pressurized reaction vessel equipped with a stirrer, heating / cooling device, thermometer, air inlet tube, pressure reducer, and water reducer was charged with 48.0 parts of amorphous vinyl resin (A-1), 52.0 parts of 1-docosanol, and 0.2 parts of titanium tetrabutoxide, and then the mixture was heated to 150°C in a sealed state with stirring. The reaction was carried out for 3 hours while maintaining the temperature inside the reaction vessel at 150°C. Subsequently, transesterification was carried out for 15 hours at 150°C under a reduced pressure of 0.5 to 2.5 kPa while distilling off the distillate. It was confirmed that at least 97% of the 1-docosanol had reacted, yielding toner binder (C-1).

[0073] The reaction rate of the monohydric alcohol (B) having 18 to 30 carbon atoms can be calculated by a method for identifying the amount of remaining monomer, such as NMR or GC, but here it was calculated by NMR. <Measurement conditions> Equipment: Bruker BioSpin "AVANCE III HD400" Number of times accumulated: 4 times Relaxation time: 1 second <Sample preparation> 100 mg of the sample was placed in an NMR tube, and 0.8 ml of a deuterated solvent (for example, deuterated chloroform) was added to dissolve the resin. <Analysis and Calculation> The reaction rate was calculated by the following formula based on the area of ​​the protons of the alcohol before the reaction, the area of ​​the protons of the remaining alcohol, and the area of ​​the protons of the terminal methyl groups of the chain hydrocarbon groups of the alcohol and the toner binder (C). Reaction rate: [{area of ​​protons bonded to methylene adjacent to the hydroxyl group of the alcohol before the reaction / area of ​​protons of terminal methyl groups of the chain hydrocarbon groups of the alcohol and toner binder (C)} - {area of ​​protons bonded to methylene adjacent to the hydroxyl group of the remaining alcohol / area of ​​protons of terminal methyl groups of the chain hydrocarbon groups of the alcohol and toner binder (C)}] / {area of ​​protons bonded to methylene adjacent to the hydroxyl group of the alcohol before the reaction / area of ​​protons of terminal methyl groups of the chain hydrocarbon groups of the alcohol and toner binder (C)} × 100 For example, if the alcohol is 1-docosanol, the proton bonded to the methylene adjacent to the hydroxyl group (approximately 3.7 ppm) and the proton of the terminal methyl group of the chain hydrocarbon group (approximately 0.9 ppm) were used.

[0074] <Examples 2 to 8> [Production of Toner Binders (C-2) to (C-8)] Toner binders were produced in the same manner as in Example 1, except that amorphous vinyl resin (A) and monohydric alcohol (B) having 18 to 30 carbon atoms were added in the blending parts of the raw materials shown in Table 2, and it was confirmed that 97% or more of the alcohol (B) had reacted during the transesterification, thereby obtaining toner binders (C-2) to (C-8) according to Examples 2 to 8.

[0075] Comparative Examples 1 and 2 [Production of Toner Binders (C'-1) and (C'-2)] Toner binders were produced in the same manner as in Example 1, except that amorphous vinyl resin (A), amorphous or crystalline vinyl resin (A'), monohydric alcohol (B) having 18 to 30 carbon atoms, and monohydric alcohol (B') having 16 carbon atoms were added in the blending parts of the raw materials shown in Table 2, and that 97% or more of the alcohol (B) or alcohol (B') was confirmed to have reacted during the ester exchange. Toner binders (C'-1) to (C'-2) according to Comparative Examples 1 and 2 were obtained.

[0076] Comparative Example 3 [Production of Toner Binder (C'-3)] 48.0 parts of amorphous vinyl resin (A-1) and 52.0 parts of 1-docosanol were added to a pressure reactor equipped with a stirrer, heating / cooling device, thermometer, air inlet tube, pressure reducing device, and water reducing device, and then the temperature was raised to 80°C in a sealed state with stirring. The temperature inside the reactor was maintained at 80°C and the mixture was stirred for 1 hour. It was confirmed that at least 99% of the 1-docosanol remained, yielding toner binder (C'-3).

[0077] Comparative Example 4 [Production of Toner Binder (C'-4)] The crystalline vinyl resin (A'-2) produced in Comparative Production Example 2 was used as a toner binder (C'-4).

[0078] Table 2 shows the compositions and physical properties of the toner binders (C-1) to (C-8) obtained in Examples 1 to 8 and the toner binders (C'-1) to (C'-4) obtained in Comparative Examples 1 to 4.

[0079] [Table 2]

[0080] Example 9 [Production of Toner (T-1)] To 86 parts of the toner binder (C-1) according to Example 1, 7 parts of a pigment carbon black (MA-100, manufactured by Mitsubishi Chemical Corporation) as a colorant, 5 parts of a release agent Fischer-Tropsch wax (FT-0070, manufactured by Nippon Seiro Co., Ltd.), and 1 part of a charge control agent (T-77, manufactured by Hodogaya Chemical Co., Ltd.) were added, and a toner was prepared by the following method. First, the mixture was premixed using a Henschel mixer [FM10B, manufactured by Nippon Coke and Engineering Co., Ltd.], and then kneaded using a twin-screw kneader [PCM-30, manufactured by Ikegai Corporation]. Next, the mixture was finely pulverized using a supersonic jet mill, Labojet [KJ-25, manufactured by Kurimoto Iron Works Co., Ltd.], and then classified using an elbow jet classifier [EJ-L-3 (LABO) model, manufactured by Matsubo Corporation] to obtain toner particles with 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 9.

[0081] <Examples 10 to 16> [Production of Toners (T-2) to (T-8)] Toners (T-2) to (T-8) were obtained in the same manner as in Example 9, except that the toner binder (C-1) in Example 9 was replaced with (C-2) to (C-8).

[0082] Comparative Examples 5 to 8 [Production of Toners (T'-1) to (T'-4)] Toners (T'-1) to (T'-4) were obtained in the same manner as in Example 9, except that the toner binder (C-1) in Example 9 was replaced with (C'-1) to (C'-4).

[0083] [Evaluation method] The following describes the methods for evaluating the low-temperature fixability, heat-resistant storage stability under high temperature and humidity conditions, long-term stability, document offset resistance after continuous printing, and charging stability of the obtained toners (T-1) to (T-8) and (T'-1) to (T'-4), including the criteria for evaluation.

[0084] <Low temperature fixability> Toner is applied to the paper at 1.00 mg / cm 2 The powder was applied evenly to the paper surface using a printer with the thermal fixing unit removed. 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 ranging from 80 to 180°C in 5°C increments. The fixed image was then visually inspected for cold offset, and the temperature at which cold offset occurs (MFT) was measured. The lower the temperature at which cold offset occurs, the better the low-temperature fixability, and under these evaluation conditions, the MFT is generally preferably 110° C. or less. Note that for (T'-3) of Comparative Example 7, defects occurred over the entire range of 80 to 180° C., so it was marked as "-".

[0085] <Heat resistance under high temperature and humidity conditions> 1 g of toner and 0.013 g of Aerosil R8200 (manufactured by Evonik Japan Co., Ltd.) were mixed in a shaker for 1 hour, the mixture was placed in an airtight container, and left to stand for 48 hours in an atmosphere of 47°C and 90% humidity. The cohesion was measured using a powder tester, and the heat-resistant storage stability under high temperature and high humidity conditions was evaluated. The lower the value in the cohesion test determined by the following method, the better the heat-resistant storage stability under high temperature and high humidity conditions. Under these evaluation conditions, a cohesion of 4% or less is preferred. Equipment: Powder Tester model PT-X (manufactured by Hosokawa Micron) Sieve openings: 355μm, 250μm, 150μm Vibration width: 1mm Vibration duration: 30 seconds Operation method: Place sieves on the vibration table of the powder tester in the following order: top 355μm, middle 250μm, bottom 150μm. Place 1g of toner on the top sieve and vibrate at a vibration amplitude of 1mm for 30 seconds, then measure the weight of toner remaining on each sieve. Cohesion: Calculated from the weight of the toner used for measurement and the weight of the toner remaining after sieving. Cohesion degree (%)=(U / N+M / N×3 / 5+L / N×1 / 5)×100 U: Weight of the top row, M: Weight of the middle row, L: Weight of the bottom row, N: Weight of the sample (1g)

[0086] <Long-term stability> 1 g of toner was placed in an open container and left to stand for 30 days in a constant temperature dryer at 47°C. The toner after standing for 30 days and the toner that had been left to stand for 30 days in an environment of 25°C and 50% humidity without being placed in the 47°C dryer were subjected to elemental analysis using an X-ray photoelectron spectrometer (AXIS NOVA, manufactured by Shimadzu Corporation), and the long-term stability was evaluated by comparing the carbon atom concentration on the toner surface. [Judgment criteria] The carbon atom concentration (%) of the toner left standing at 47°C for 30 days was divided by the carbon atom concentration (%) of the toner left standing at 25°C and 50% humidity for 30 days, and the result was calculated as follows: × 100 (%). In this evaluation, 10% or less is preferable.

[0087] <Document offset resistance after continuous printing> The toner was used to make 10,000 continuous copies using a commercially available monochrome copier [AR5030, manufactured by Sharp Corporation]. Using the fixed image at 120°C after 10,000 continuous copies, the image area was stacked facing the non-image area and the image area so that they overlapped, and a load of 80 g / cm was applied to the overlapping area. 2 A weight was placed on the sheet to provide a suitable weight, and the sheet was left in a high-temperature, high-humidity chamber at 50°C and 50% humidity for 24 hours. After leaving the sheet, the degree of image defects on the two overlapping fixed images was visually judged, and the document offset resistance (paper blocking resistance during continuous printing) was evaluated according to the following criteria. The evaluation criteria were ◯ and ⊚, which were deemed to be acceptable for practical use, and △ and × were deemed to be unacceptable. [Evaluation criteria] ⊚: No image transfer was observed in either the image or non-image areas. ◯: No white spots are observed in the image area. Slight image transfer is observed in the non-image area. △: White spots are observed in the image area, and image transfer is also observed in the non-image area. ×: Two overlapping prints are stuck together and cannot be peeled off, and when forcibly peeled off, the entire surface of the paper comes off, causing severe image loss.

[0088] <Charging stability> 0.5 g of 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 at least 8 hours. Next, the mixture was subjected to friction stirring at 50 rpm in a Turbula shaker mixer for 10 minutes and 60 minutes, and the charge amount at each time was measured using a blow-off charge amount measuring device (manufactured by Kyocera Chemical Corporation). Using the obtained values, "charge amount after 60 minutes of friction / charge amount after 10 minutes of friction x 100 (%)" was calculated, and this was taken as the charge stability index. A larger charge stability index indicates a better charge retention rate. Under these evaluation conditions, a charge stability index of 80% or more is preferable.

[0089] The evaluation results are shown in Table 3.

[0090] [Table 3]

[0091] As is clear from the evaluation results in Table 3, all of the toners (T-1) to (T-8) containing the toner binders (C-1) to (C-8) of Examples 1 to 8 produced by the production method of the present invention achieved excellent results in all performance evaluations. On the other hand, the toners (T'-1) to (T'-4) containing the toner binders (C'-1) to (C'-4) according to Comparative Examples 1 to 4 were poor in some performance items. [Industrial Applicability]

[0092] The toner binder of the present invention can be suitably used as an electrophotographic toner used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like. Furthermore, it is suitable for use as an additive for paints, an additive for adhesives, particles for electronic paper, and the like.

Claims

1. A method for producing a toner binder, comprising a step of transesterifying an amorphous vinyl resin (A) containing an alkyl(meth)acrylate having 4 to 9 carbon atoms as a constituent monomer with a monohydric alcohol (B) having 18 to 30 carbon atoms, wherein the amorphous vinyl resin (A) contains the alkyl(meth)acrylate having 4 to 9 carbon atoms as a constituent monomer in an amount of 30 to 95% by weight based on the weight of all constituent monomers of the amorphous vinyl resin (A).

2. 2. The method for producing a toner binder according to claim 1, further comprising a step of reducing the pressure in the reaction system during and / or after the transesterification reaction.

3. 3. The method for producing a toner binder according to claim 1, wherein a weight ratio [(A):(B)] of the amorphous vinyl resin (A) to the monohydric alcohol having 18 to 30 carbon atoms before the transesterification reaction is 35:65 to 70:

30.

4. The method for producing a toner binder according to claim 1 or 2, wherein the toner binder has at least one endothermic peak top temperature (Tm) in the range of 45 to 100° C. The endothermic peak top temperature (Tm) is measured using a differential scanning calorimeter, and is the peak top temperature of the endothermic peak during a second heating process when the toner binder is first heated from 20° C. to 150° C. at a rate of 10° C. / min, then cooled to 0° C. at a rate of 10° C. / min, and then heated a second time from 0° C. to 150° C. at a rate of 10° C. / min.

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