JPH05323664A - Toner for developing electrostatic latent image - Google Patents

Abstract

PURPOSE:To obtain a toner having a low fixing temp., blocking resistance and anti-offsetting property and giving a clear fine image. CONSTITUTION:This toner contains styrene resin, polyester resin and a pectinate graft copolymer consisting of segments compatible with the styrene resin and segments compatible with the polyester resin as the components of a resin binder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic latent image in an electrophotographic process, and more particularly to a toner for developing an electrostatic latent image for fixing on a heat roller having a low fixing temperature.

[0002]

BACKGROUND OF THE INVENTION In electrophotographic processes, a photoconductive photoreceptor is charged and exposed to form an electrostatic latent image, which is then developed with a developer and thus obtained. The obtained toner image is transferred to a paper base material or the like and is fixed by heating and / or pressing to obtain an image. Conventionally, various methods have been proposed and put to practical use for fixing such a toner image, but among them, a fixing method using a heat roller is widely adopted from the viewpoint of safety, thermal efficiency, and the like.

On the other hand, in recent years, in order to speed up the electrophotographic process, downsize the apparatus, and save energy, it is necessary to reduce the diameter of the roller and the capacity of the heater even in the fixing method using a heat roller. Therefore, there is a demand for a toner that can be fixed at a lower temperature than before. To impart low-temperature fixability to the toner, a resin having a low glass transition point or a resin having a low softening point may simply be used as the binder resin. However, according to such a method,
During storage of toner, toner particles adhere to each other and agglomerate to cause blocking, or so-called filming occurs in which toner is fused to a carrier or a photoconductor.

Therefore, for example, Japanese Patent Laid-Open No. 59-18534.
No. 8 and Japanese Patent Application Laid-Open No. 61-56352 propose a method of coating the surface of such toner particles with a polymer film using a microencapsulation technique. 54-28630, JP-A-61-56
No. 353, JP-A-61-56353, etc.
It has been proposed to fix inorganic or organic fine particles to the toner surface. However, in such a method, the processing is complicated, and the charge control of the obtained toner is insufficient and uncertain, so that a clear and beautiful copied image cannot be obtained.

As another method for obtaining a low-temperature fixing toner, a resin having a molecular weight distribution consisting of a high molecular weight component and a low molecular weight component, of which a low molecular weight component is abundant, is used as a binder resin for the toner. It can be used, for example, in JP-A-59-223453 and JP-A-60-2.
No. 52361, JP-A-60-252362, and the like. According to this method, the so-called sharpness / melting property of the toner is improved, but the toner is apt to cause blocking, and there is a limit as a measure for improving the low temperature fixing property.

Further, use of a linear polyester resin which is a crystalline polymer in order to impart a sharp melt property to the toner has been proposed in, for example, Japanese Patent Laid-Open No. 54-86342. There is a problem with the hot / offset property. As a measure for improving the offset resistance, a method of introducing a cross-linking component into a binder resin has been generally known, but this method has a harmful effect on the sharpness and meltability of the toner.

As described above, conventionally, it is difficult to simultaneously satisfy the blocking resistance and the low-temperature fixing property by the method using a single resin as the binder resin. In order to solve this problem, recently, a method of using various graft copolymers, block copolymers, or a mixture of various resins as a binder resin of toner has been proposed. However, according to a method of using a conventionally known ordinary copolymer alone, or a method of using a compatible resin mixture, although the blocking resistance is improved, the low temperature fixing property is not sufficient, On the other hand, in the method using the incompatible resin mixture, the toner is easily pulverized when the toner is pulverized or mixed with the carrier. Therefore, the combined use of a compatibilizing agent composed of a graft copolymer with an incompatible resin mixture has been proposed, for example, in JP-A-63-60456 and JP-A-63-60457. However, such a conventional compatibilizer requires a large amount of compounding, which increases the manufacturing cost.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in low-temperature fixing toners, and has a low fixing temperature, blocking resistance, and offset resistance. An object is to provide a toner that gives a clear and beautiful image.

[0009]

The first of the toner for developing an electrostatic latent image according to the present invention is, as a binder resin, (a) a styrene resin, (b) a polyester resin, and (c) the styrene resin. It is characterized by containing a comb-type graft copolymer comprising a segment compatible with the above and a segment compatible with the above polyester resin. Hereinafter, the comb-type graft copolymer will be referred to as a first comb-type graft copolymer.

The styrene resin used in the present invention is
Aromatic vinyl monomer is copolymerized with α, β-unsaturated carboxylic acid ester and, if necessary, carboxyl group-containing vinyl monomer or crosslinkable monomer such as α, β-unsaturated carboxylic acid. Can be obtained. Examples of the aromatic vinyl monomer include styrene and o-
Methyl styrene, p-methyl styrene, p-ethyl styrene, α-methyl styrene, 2,4-dimethyl styrene,
pt-butyl styrene, pn-octyl styrene,
pn-dodecylstyrene, p-methoxystyrene, p
Examples thereof include styrene derivatives such as -phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene.

Examples of the α, β-unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, propyl acrylate, n-octyl acrylate. , Dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate , Propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacrylic acid. Phenyl, dimethylaminoethyl methacrylate, mention may be made of diethylaminoethyl methacrylate and the like.

Examples of the crosslinkable monomer include aromatic divinyl compounds, (poly) alkylene glycol poly (meth) acrylate, polyhydric alcohol poly (meth) acrylate and the like. Specifically, as the aromatic divinyl compound, for example, divinylbenzene, divinylnaphthalene, etc. are preferably used. Further, as the (poly) alkylene glycol poly (meth) acrylate,
For example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, etc. are preferably used as the polyhydric alcohol poly (meth) acrylate, for example, trimethylolpropane trimethylolpropane acrylate, etc.

Therefore, as the styrene resin which can be preferably used in the present invention, for example, a styrene-n-butyl acrylate-divinylbenzene copolymer, a styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, Styrene-n-butyl methacrylate-acrylic acid copolymer, styrene-n-butyl methacrylate-
Examples thereof include a methacrylic acid copolymer and a styrene-n-butyl methacrylate-n-butyl acrylate copolymer.

The polyester resin used in the present invention is a linear polyester obtained by polycondensing a dihydric alcohol and a divalent carboxylic acid, or a trivalent or higher polyhydric alcohol together with a dihydric alcohol and a divalent carboxylic acid. It is a non-linear polyester obtained by using a polyhydric alcohol or a polycarboxylic acid. Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol and the like. Diols,
Examples include etherified bisphenols such as 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropyleneated bisphenol A, and the like.

Examples of the divalent carboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, succinic acid, fumaric acid, adipic acid,
Maleic acid, sebacic acid, decamethylene dicarboxylic acid,
Aliphatic dicarboxylic acids such as mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, malonic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, etc. Examples thereof include dicarboxylic acids, their acid anhydrides, dimers of lower alkyl esters and linoleic acid, and the like.

Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexanetetrol, 1,
4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,
4-butanetriol, 1,2,5-pentanetriol,
Examples thereof include glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolbutane, trimethylolpropane and 1,3.5-trihydroxymethylbenzene.

Examples of the trivalent or higher polyvalent carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5, 7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Carboxylpropane, tetra (methylenecarboxyl) methane, 1,2,7,8
Examples thereof include octane tetracarboxylic acid, embol trimer, acid anhydrides or lower alkyl esters thereof.

However, in the present invention, a linear polyester resin is preferably used. Examples of such a linear polyester resin include (poly) alkylene glycol and a divalent carboxylic acid, and particularly 4 to 4 carbon atoms.
Resins obtained by polycondensation of 20 with aliphatic dibasic acids, such as polyethylene sebacate, polyethylene adipate, polyethylene succinate, polyethylene-
p- (Carbophenoxy) undecaate, Polyethylene-p- (Carbophenoxy) butyrate, Polyethylene-p-phenylenediacetate, Polyhexamethylene carbonate, Polyhexamethylene-p- (Carbophenoxy) undecaate, Polyhexamethylene oxalate, Polyhexa Methylene sebacate, polyhexamethylene decandioate, polyoctamethylene dodecanedioate, polynonamethylene azelate, polynonamethylene terephthalate, polydecamethylene adipate, polydecamethylene azelate, polydecamethylene oxalate, polydecamethylene Sebacate, polydecamethylene succinate, polydecamethylene dodecanedioate,
Polydecamethylene octadecanedioate, polytetramethylene sebacate, polytetramethylene-p-phenylene diacetate, polytrimethylene dodecanedioate, polytrimethylene octadecanedioate, polytrimethylene oxalate, poly-p-xylene Adipate, poly-p-xylene sebacate, poly-4,4'-isopropylidene diphenylene adipate, poly-4,4'-isopropylidene phenylene malonate, polyhexamethylene decamethylene sebacate, polydecamethylene sebacate Cate terephthalate, polydecamethylene-2-methyl-
1,3-propanediol dodecanedioate and the like can be mentioned.

The styrene resin and the polyester resin used in the present invention are mutually incompatible. The first comb-type graft polymer used in the present invention is a graft copolymer composed of a segment compatible with the styrene resin and a segment compatible with the polyester resin, and usually has a trunk portion. It consists of an eggplant segment and a segment that forms a branch portion.

A toner in which these resins are uniformly mixed cannot be obtained only by using the above-mentioned styrene resin and polyester resin which are incompatible with each other as the binder resin. However, according to the present invention, since the first comb-type graft copolymer as described above is used as a compatibilizing agent for the styrene resin and the polyester resin, the first comb-type graft copolymer is The trunk portion is compatible with the dispersed phase, the branch portion is compatible with the continuous phase, and thus is coordinated at the interface between the styrene resin and the polyester resin as a surfactant, so that in the toner, the styrene resin And the polyester resin can be dispersed microscopically and uniformly.

In the present invention, either the styrene resin or the polyester resin may be the continuous phase or the dispersed phase, but the resin forming the dispersed phase is more preferable than the resin forming the continuous phase. It has a low glass transition point, and the glass transition point is preferably 60 ° C. or lower, and particularly preferably 55 ° C. or lower. Particularly, in the present invention, it is preferable that a continuous phase is formed in the styrene resin and the linear polyester resin is uniformly dispersed in this continuous phase to form the dispersed phase.

Generally, the comb-type graft polymer is, for example,
"Polymer Alloy" edited by The Society of Polymer Science, Japan (1981)
As described in Tokyo Kagaku Dojin), it is already known, for example, a polymer having a polymerizable double bond at the molecular end, that is, a high molecular weight monomer (macromer (CPC I
nternational Inc.). ) With an appropriate comonomer,
A comb-type graft copolymer can be obtained.

The first comb-type graft copolymer used in the present invention comprises, for example, a vinyl monomer having a functional group capable of reacting with a carboxyl group and a monomer capable of forming the styrene resin. It can be obtained by radical polymerization and then polycondensation with the monomers constituting the polyester resin. Also, by radical copolymerizing an unsaturated polyester having at least two vinyl groups in the main chain or side chains with a monomer (or macromer) capable of forming the styrene resin, Can be obtained.

The second electrostatic latent image developing toner according to the present invention comprises (a) a styrene resin and (b) a binder resin.
A polyester resin, and (c) a comb-shaped graft copolymer consisting of a trunk portion and a branch portion, the trunk portion or the branch portion constituting a segment compatible with the styrene resin or a segment compatible with the polyester resin. Containing a polymer, one of the styrene resin and the polyester resin constitutes a dispersed phase, the other forms a continuous phase,
The comb-shaped graft copolymer has a functional group in the trunk portion, and is chemically bonded to the resin constituting the dispersed phase by the functional group.

That is, the second electrostatic latent image developing toner according to the present invention uses the second comb-type graft copolymer as described above. The second comb-shaped graft polymer is composed of a trunk portion and a branch portion, and the trunk portion or the branch portion constitutes a segment compatible with the styrene resin or a segment compatible with the polyester resin. Further, the comb-type graft copolymer has a functional group in the trunk portion, and the functional group is chemically bonded to the resin constituting the dispersed phase.

In particular, in the present invention, the second comb-type graft copolymer has a trunk portion composed of a segment compatible with the resin constituting the dispersed phase and a branch portion of the resin constituting the continuous phase. It is preferably composed of compatible segments. In the second electrostatic latent image developing toner according to the present invention, the functional group in the resin forming the dispersed phase may include, for example, a carboxyl group, a hydroxyl group, an amino group, and the like. It is not limited. Examples of the functional group contained in the trunk portion of the second comb graft copolymer that can be chemically bonded to the functional group in the resin forming the dispersed phase include, for example, an epoxy group and an isocyanate group. However, the present invention is not limited to these.

As described above, a toner in which these resins are uniformly mixed can be obtained only by using the above-mentioned styrene resin and polyester resin which are incompatible with each other as the binder resin in the toner. Can not. However, according to the present invention, by using the second comb-type graft copolymer as described above as a compatibilizing agent for the styrene resin and the polyester resin, the comb-type graft copolymer is The trunk part is compatible with the dispersed phase in the form of being chemically bonded to the dispersed phase, and the branch part is compatible with the continuous phase,
Thus, the toner is coordinated at the interface between the styrene resin and the polyester resin as if it were a surfactant,
The styrene resin and the polyester resin are dispersed microscopically and uniformly.

The second comb-type graft copolymer used in the present invention is, for example, an unsaturated polyester having an epoxy group or an isocyanate group as a functional group as described above together with a vinyl group and the styrene resin. It can be obtained by radical copolymerization with a monomer or macromer capable of forming Further, by combinating the polyester resin having a carboxyl group, a hydroxyl group or an amino group at the terminal with the styrene resin having an epoxy group or an isocyanate group in the side chain, a comb graft copolymer can be obtained. be able to.

The third electrostatic latent image developing toner according to the present invention comprises (a) a styrene resin and (b) a binder resin.
A polyester resin, and (c) a comb-shaped graft copolymer consisting of a trunk portion and a branch portion, the trunk portion or the branch portion constituting a segment compatible with the styrene resin or a segment compatible with the polyester resin. Containing a polymer, one of the styrene resin and the polyester resin constitutes a continuous phase, the other constitutes a dispersed phase,
While any of the above segments has compatibility with the continuous phase, the comb-shaped graft copolymer has a functional group in the trunk portion, by this functional group, chemically to the resin constituting the dispersed phase It is characterized by being combined.

That is, the third electrostatic latent image developing toner according to the present invention uses the above-mentioned third comb graft copolymer. The third comb-shaped graft polymer is composed of a trunk portion and a branch portion, and these trunk portions or branch portions constitute a segment compatible with the styrene resin or a segment compatible with the polyester resin. In addition, both of the above segments have compatibility with the continuous phase, and further,
This comb-shaped graft copolymer has a functional group in the trunk portion, and is chemically bonded to the resin constituting the dispersed phase by this functional group.

In the electrostatic latent image developing toner according to the present invention as described above, examples of the functional group in the resin constituting the dispersed phase include a carboxyl group, a hydroxyl group and an amino group. It is not limited to. The functional group contained in the trunk portion of the third comb-shaped graft copolymer that can be chemically bonded to the functional group in the resin forming the dispersed phase is, for example, an epoxy group as described above. , Isocyanate groups and the like, but are not limited thereto.

As described above, a toner in which these resins are uniformly mixed can be obtained only by using the above-mentioned styrene resin and polyester resin which are incompatible with each other as the binder resin in the toner. Can not. However, according to the present invention, by using the above-mentioned third comb-shaped graft copolymer as a compatibilizing agent for the styrene resin and the polyester resin, a part of the trunk portion thereof becomes a dispersed phase. Since it is compatible with the dispersed phase and the continuous phase in a chemically bonded form, the adhesiveness at the interface between the styrene-based resin and the polyester-based resin is further enhanced, and the styrene-based resin and the polyester-based resin are mixed in the toner. Can be uniformly and stably dispersed.

Such a third comb-type graft copolymer used in the present invention comprises, for example, a high molecular weight monomer composed of a monomer constituting a styrene resin and a reactive functional group such as an epoxy group. It can be obtained by radically copolymerizing the monomer which it has with the monomer which comprises styrene resin. According to the present invention, in any of the toners for developing an electrostatic latent image as described above in any one of the above-mentioned toners, a continuous phase is contained in a resin mixture composed of a styrene resin, a polyester resin and a comb-type graft copolymer. 50 to 95% by weight, based on the toner, of the resin constituting the dispersed phase is preferably in the range of 5 to 50% by weight, and the comb-type graft copolymer is 1 to 50% by weight. , Especially 2-1
The range of 0% by weight is preferred.

For example, when the styrene resin is the continuous phase and the polyester resin is the dispersed phase, the styrene resin is in the range of 50 to 95% by weight based on the toner, and the polyester resin is It is preferably in the range of 5 to 50% by weight. When the styrene resin is the continuous phase and the polyester resin is the dispersed phase, the polyester resin is in the range of 50 to 95 wt% and the polystyrene resin is 5 to 50 wt% based on the toner. It is preferably in the range of.

The toner for developing an electrostatic latent image according to the present invention comprises a styrene resin, a polyester resin, a comb-type graft copolymer, a colorant, and if necessary, a wax as a charge control agent and an offset preventing agent. It can be obtained by mixing magnetic powder and the like, kneading, pulverizing and classifying. As the colorant, any of those conventionally used in toners for developing electrostatic latent images can be used. Examples of such colorants include, for example, carbon black, nigrosine dye (CI No. 50415), aniline blue (CI N
o. 50405), Calco Oil Blue (CI No. azoic Blu
e 3), Chrome Yellow (CI No. 14090), Ultramarine Blue (CI No. 77103), DuPont Oil Red (CI No. 26105), Quinoline Yellow (CI No. 470).
05), methylene blue chloride (CI No. 52015),
Phthalocyanine Blue (CI No. 74160), Malachite Green Oxalate (CI No. 42000), Lamp Black (CI No. 77266), Rose Bengal (CI No. 4)
5435) and the like.

In addition to these, various organic or inorganic chromatic color dyes and chromatic pigments can be used as the coloring agent, but in particular, the organic color is clear and has excellent light resistance and hiding power. Chromatic pigments are preferably used. Examples of such chromatic color pigments include CI pigment red 5 (Permanent Carmine FB, Hoechst Japan Corp.), CI pigment red 48: 1 (Sumika Print Red C, Sumitomo Chemical Co., Ltd.), CI pigment red 53:
1 (Chromoftal Magenta G, Ciba Geigy),
CI Pigment Red 57: 1 (Sumika Print Carmine 6BC, Sumitomo Chemical Co., Ltd.), CI Pigment Red 123
(Kayasetutredo EB, Nippon Kayaku), CI Pigment Red 139 (Kayasetutredo E-GR, Nippon Kayaku), CI Pigment Red 144 (Chromoftal Red BRN, Ciba Geigy), CI Pigment Red 149 (PV Hua Stred B, Hoechst Japan), CI Pigment Red 166 (Chromoftal Scarlet R, Ciba Geigy), CI Pigment Red 177 (Chromoftal Red A38, Chiba Geigy) , CI Pigment Red 178 (Kayasettsu E-GG, Nippon Kayaku Co., Ltd.), CI Pigment Red 2
22 (Chromoftal Red Magenta G, Ciba Geigy), CI Pigment Orange 31 (Chromoftal Orange 4R, Ciba Geigy), CI Pigment Orange 43 (Hosta Palm Orange GR, Hoechst), CI Pigment Yellow 17 (Fast Yellow GBFN, Sumitomo Chemical Co., Ltd.), CI Pigment Yellow 14
(Benzidine Yellow OT, Deupon), CI Pigment Yellow 138 (Variotor Yellow L0960
HD, Basuf), CI Pigment Yellow 93 (Chromoftal Yellow 3G, Ciba Geigy), CI Pigment Green 7 (Chromoftal Green GF, Ciba Geigy), CI Pigment Green 36 (Cyanine Green S537-2Y) , Dainichi Seika Co., Ltd., CI Pigment Blue 15: 3 (Cyanine Blue A330, Sanyo Pigment Co., Ltd.), CI Pigment Blue 60 (Chromoftal Blue A3R, Ciba Geigy), CI Pigment Biolett 23 (Sumika Print Forst Bio) Lett RLN, Sumitomo Chemical Co., Ltd.) and the like.

If necessary, red iron oxide, titanium oxide, carbon black and the like may be used in combination with the above-mentioned coloring agent. Examples of chromatic dyes include azo dyes, anthraquinone dyes, indigoid dyes, quinone imine dyes and phthalocyanine dyes. These colorants may be used alone, or
You may use 2 or more types together. The colorant is usually used in the range of 1 to 20 parts by weight with respect to 100 parts by weight of the binder resin. Further, when a magnetic toner is obtained, coloring magnetic powder can be used as a coloring agent.

As the charge control agent, any charge control agent conventionally used in toners for developing electrostatic latent images can be used.
As a negatively chargeable charge control agent, JP-A-57-1414 is known.
52, JP-A-58-7645, JP-A-58
-1111049, JP-A-58-185653, JP-A-57-167033, JP-B-44-6.
2: 1 type metal-containing azo dyes such as those described in JP-A No. 397 and the like, for example, JP-A-57-104940, JP-A-57-111541 and JP-A-57-12435.
No. 7, JP-A-53-127726, and other metal complexes of aromatic oxycarboxylic acids and aromatic dicarboxylic acids, such as those described in JP-A-52-45931. Examples thereof include sulfonylamine derivatives of copper phthalocyanine dyes and sulfonamide derivative dyes of copper phthalocyanine.

Examples of the positively chargeable charge control agent include, for example, JP-A-49-51951 and JP-A-52-1.
Quaternary ammonium compounds such as those described in JP-A-0141 and the like, for example, JP-A-56-11461, JP-A-54-158932, and US Pat.
54,205 alkylpyridinium compounds such as those described in the specification, alkylpicolinium compounds,
Various nigrosine dyes and the like can be mentioned.

Such a charge control agent is used in an amount of 0.1 to 10 parts by weight, particularly 0.3, based on 100 parts by weight of the binder resin.
It is preferable that the range is from 5 to 5 parts by weight. As the offset preventing agent, for example, various waxes having a melting point in the range of 50 to 150 ° C. can be preferably used. Specifically, for example, liquid or solid paraffin, polyethylene, polyolefin wax such as polypropylene, aliphatic metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, silicone varnish, amide wax, fat Examples thereof include group fluorocarbons and modified products thereof.

Such an anti-offset agent is usually used in an amount of 0.1 to 30 parts by weight, particularly 0.2 to 10 parts by weight, based on 100 parts by weight of the binder resin.

[0042]

As described above, according to the toner for developing an electrostatic latent image of the present invention, as a binder resin, a styrene resin and a polyester resin which are mutually incompatible,
Since it contains a comb-shaped graft copolymer having a segment compatible with the styrene resin and a segment compatible with the polyester resin, the styrene resin and the polyester resin are microscopically uniformly dispersed, Moreover, since the styrene-based resin and the polyester-based resin have excellent adhesion at the interface, the polymer particles constituting the dispersed phase do not separate from the toner during pulverization or mixing with the carrier, and Does not cause filming.

In particular, when the second graft copolymer is used, the styrene resin and the polyester resin are different from each other because the trunk portion of the comb graft copolymer is chemically bonded to the dispersed phase. Excellent adhesion at the interface, as well as
When the third graft copolymer is used, a part of the trunk portion of the comb-shaped graft copolymer is chemically bonded to the dispersed phase and is compatible with the dispersed phase and the continuous phase. The adhesiveness at the interface between the polyester resin and the polyester resin is further enhanced.

Thus, according to the toner of the present invention,
The styrene resin and the polyester resin can be dispersed microscopically uniformly and stably, the polymer particles forming the dispersed phase do not separate from the toner during pulverization or mixing with the carrier, and Does not cause filming on the body. Further, according to the electrostatic latent image developing toner of the present invention, the polymer constituting the dispersed phase is hard to be exposed on the surface of the toner, so that the blocking does not occur during storage of the toner.

As described above, according to the present invention, the comb-type graft copolymer is excellent in the action as the compatibilizing agent.
Conventionally, using a polymer having a low melting point or a low glass transition point which has been difficult to use, the fixing temperature is low, and
It is possible to obtain a low-temperature fixing toner having a blocking resistance and an offset resistance and giving a clear and beautiful image.

[0046]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Example 1 A styrene-n-butyl methacrylate-n-butyl acrylate copolymer having a glass transition point of 60 ° C. was used as the styrene resin, and polyhexamethylene having a glass transition point of 47 ° C. was used as the polyester resin. Sebacate was used. As the comb-shaped graft copolymer, polyhexamethylene sebacate forming the trunk portion and styrene-n-butyl acrylate copolymer having an epoxy group at the terminal forming the branch portion are heated at 150 ° C. for 30 minutes. The one prepared by stirring was used.

Along with the above resin, carbon black (Diablack MA-100, manufactured by Mitsubishi Kasei Co., Ltd.) as a colorant, and Spyron Black TRH as a charge control agent.
(Hodogaya Chemical Co., Ltd. Chromium-containing azo pigment) and polyethylene wax as an offset inhibitor (Sanyo Kasei Co., Ltd., Viscole 400P) were used to prepare toners with the formulations shown in Table 1.

Example 2 In Example 1, a styrene-n-butyl methacrylate-n-butyl acrylate copolymer having a glass transition point of 45 ° C. was used as the styrene resin, and a glass transition point of 72 as the polyester resin. In addition to using polydecamethylene adipate at 60 ° C., as the comb-type graft copolymer, styrene-n-butyl acrylate-acrylic acid copolymer forming the trunk portion and polydecamethylene adipate forming the branch portion were formed at 160 ° C. A toner having the composition shown in Table 1 was prepared in the same manner as in Example 1 except that the toner prepared by heating and stirring for 20 minutes was used.

Comparative Example 1 A toner was prepared in the same manner as in Example 1 except that the comb-type graft copolymer was not used.

Comparative Examples 2 and 3 In Example 1, instead of the comb-shaped graft copolymer, a graft copolymer obtained by binding polypropylene isophthalate and polyhexamethylene sebacate with hexamethylene diisocyanate was used. A toner was prepared in the same manner as in Example 1 except for the above.

Next, for 100 parts by weight of each of the above-mentioned toners, hydrophobic silica fine powder Aerosil R972
(Nippon Aerosil Co., Ltd.) 0.4 part by weight was mixed and mixed with a Henschel mixer to obtain a toner having an average particle diameter of 12.5 μm. This toner was mixed with a carrier using a V-type blender so that the toner concentration was 5% to prepare a developer.

Example 3 A styrene-n-butyl methacrylate-n-butyl acrylate copolymer having a glass transition point of 60 ° C. was used as a styrene resin, and polyhexamethylene having a glass transition point of 47 ° C. was used as a polyester resin. Sebacate was used. Further, as the comb-shaped graft copolymer, an epoxy-modified polyester forming the trunk portion and a terminal dihydroxylated styrene-n-butyl acrylate copolymer forming the branch portion are heated and stirred at 150 ° C. for 30 minutes. The prepared one was used.

Along with the above resin, carbon black (Diabrak MA-100, manufactured by Mitsubishi Kasei Co., Ltd.) as a colorant, and Spylon black TRH as a charge control agent.
(Hodogaya Chemical Co., Ltd. Chromium-containing azo pigment) and polyethylene wax as an offset inhibitor (Sanyo Kasei Co., Ltd., Viscole 400P) were used to prepare toners with the formulations shown in Table 1.

Example 4 In Example 1, a styrene-n-butyl methacrylate-n-butyl acrylate copolymer having a glass transition point of 45 ° C. was used as the styrene resin, and a glass transition point of 72 as the polyester resin. In addition to using polydecamethylene adipate at ℃, as a comb-shaped graft copolymer, epoxy-modified styrene-acrylic acid n-
The composition shown in Table 1 was obtained in the same manner as in Example 3 except that a butyl-acrylic acid copolymer and polyhexamethylene sebacate constituting the branch portion were prepared by heating and stirring at 165 ° C. for 25 minutes. To prepare a toner.

Next, for 100 parts by weight of each of the above-mentioned toners, hydrophobic silica fine powder Aerosil R972
(Nippon Aerosil Co., Ltd.) 0.4 part by weight was mixed and mixed with a Henschel mixer to obtain a toner having an average particle diameter of 12.3 μm. This toner is mixed with V so that the carrier density becomes 5%.
A developer was prepared by mixing with a toner using a mold blender.

Example 5 Epoxy-modified styrene, styrene and a high-molecular weight monomer of styrene having a double bond at the terminal were radical-polymerized with azoisobutyronitrile, and a comb-type graft copolymer was used. Carbon black as a colorant together with the above resin (Diabrak MA-100, Mitsubishi Kasei Co., Ltd.)
Table) using Spylon Black TRH (Hodogaya Chemical Co., Ltd., chromium-containing azo pigment) as a charge control agent, and Polyethylene wax (Sanyo Kasei Co., Ltd., Viscole 400P) as an offset inhibitor. 1
A toner was prepared with the formulation shown in.

Example 6 In Example 1, a high molecular weight monomer of epoxy-modified styrene, styrene and n-butyl acrylate having a double bond at the end was used as azoisobutyronitrile as a comb-type graft copolymer. A toner was prepared in the same manner as in Example 5, except that the toner prepared by radical polymerization was used.

Next, with respect to 100 parts by weight of each of the above-mentioned toners, hydrophobic silica fine powder Aerosil R972
(Nippon Aerosil Co., Ltd.) 0.4 part by weight was mixed and mixed with a Henschel mixer to obtain a toner having an average particle diameter of 12.7 μm. This toner is mixed with V so that the carrier density becomes 5%.
A developer was prepared by mixing with a carrier using a mold blender.

With respect to the toner or developer, the minimum fixing temperature, anti-blocking property, blow-off charge amount, desired image and quality of image after copying 30,000 sheets were examined. The results are shown in Table 1. The test method is as follows. Minimum fixing temperature An unfixed image is formed using a commercially available copying machine, and this is fixed using a fixing tester set under the following conditions, and the temperature at which cold offset (fixing strength is less than 90%) occurs is set. The minimum fixing temperature was set.

Fixing test condition setting temperature Hot offset: 210 ° C. Cold offset: 160 ° C. Heater roller diameter: 24.4 mm Back roller diameter: 20.0 mm Rubber hardness: 24 (JIS A) Linear velocity: 64 mm / second Back roller Pressing force: 2.2Kg Nip width: 2mm

100 g of the anti-blocking toner was placed in a beaker, allowed to stand in a gear oven at 50 ° C. for 8 hours, then returned to room temperature, the toner was spread on a paper, and the state was visually observed and evaluated. ○ indicates no change in appearance, △ indicates aggregation of a part of the toner,
X indicates that the toner is completely solidified and does not flow. 142.5 g of a commercially available iron powder carrier and 7.5 g of toner were put in a polyethylene container having a toner charge amount of 500 ml and mixed at 50 rpm for 60 minutes to prepare a sample. This sample was measured using a blow-off charge amount measuring device (TB-500, manufactured by Toshiba Chemical Co.).

Measurement conditions Blow pressure: 1 ± 0.04 Kg / cm ² Blow time: 30 seconds Blow mesh: SUS JIS-400 mesh Actual running evaluation Black / white under normal temperature and normal humidity environment using Ricopy FT-5740 manufactured by Ricoh. An image having a ratio of 5% was continuously copied on 30,000 sheets, and the image density after the continuous copy was measured by a Macbeth densitometer. The fog was measured with a white densitometer. Fogging level is 0.002 or less for ○, 0.00 for △
2 to 0.01, and x is 0.01 or more.

[0064]

[Table 1]

As is clear from the results shown in Table 1, according to the toner of the present invention, the minimum fixing temperature is 90 to 95 ° C., the blocking resistance is excellent, and even after continuous use for a long period of time, The obtained copied image has the same density as the initial one, and no fog occurs. On the other hand, the toner which does not use the comb-shaped graft copolymer as the compatibilizing agent has a high fixing temperature and has a remarkable fogging in the copied image. When a conventionally known ordinary graft copolymer is used as a compatibilizer, the same properties and performances as those according to the present invention can be obtained only when a large amount is blended.

Claims (7)

[Claims] 1. A comb comprising (a) a styrene resin, (b) a polyester resin, and (c) a segment compatible with the styrene resin and a segment compatible with the polyester resin as the binder resin. A toner for developing an electrostatic latent image, which comprises a type graft copolymer. 2. A styrene resin or a polyester resin, one of which constitutes a continuous phase and the other of which constitutes a dispersed phase, and the resin constituting this dispersed phase has a glass transition point of 60 ° C. or lower. The toner for developing an electrostatic latent image according to claim 1, which is characterized in that. 3. A styrene-based resin or a polyester-based resin, one of which constitutes a continuous phase and the other of which constitutes a dispersed phase. Based on the toner, five resins constitute this continuous phase.
The electrostatic latent image development according to claim 1, wherein 0 to 95% by weight, the resin constituting the dispersed phase is 1 to 50% by weight, and the comb graft copolymer is 1 to 50% by weight. For toner. 4. A binder resin comprising (a) a styrene resin, (b) a polyester resin, and (c) a trunk portion and a branch portion, and these trunk portions or branch portions are compatible with the styrene resin. Containing a comb graft copolymer constituting a segment or a segment compatible with the polyester resin, one of the styrene resin and the polyester resin constitutes a dispersed phase, the other is a continuous phase Formed, the comb-shaped graft copolymer has a functional group in the trunk portion, and the functional group is chemically bonded to the resin constituting the dispersed phase. Toner for latent image development. 5. A styrene resin or a polyester resin, one of which constitutes a continuous phase and the other of which constitutes a dispersed phase, and the resin constituting this dispersed phase has a glass transition point of 60 ° C. or lower. The toner for developing an electrostatic latent image according to claim 4, which is characterized in that. 6. A binder resin comprising (a) a styrene resin, (b) a polyester resin, and (c) a trunk portion and a branch portion, and the trunk portion or the branch portion is compatible with the styrene resin. Containing a comb graft copolymer constituting a segment or a segment compatible with the polyester resin, one of the styrene resin and the polyester resin constitutes a continuous phase, the other is a dispersed phase Consists of any of the above segments having compatibility with the continuous phase, the comb graft copolymer has a functional group in the trunk portion, by this functional group, in the resin constituting the dispersed phase A toner for developing an electrostatic latent image, which is chemically bonded. 7. A styrene resin or a polyester resin, one of which constitutes a continuous phase and the other of which constitutes a dispersed phase, and the resin constituting this dispersed phase has a glass transition point of 60 ° C. or lower. The toner for developing an electrostatic latent image according to claim 6, which is characterized in that.