JPH083653B2 - Toner for developing electrostatic latent image - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrostatic latent image developing toner used for developing an electrostatic latent image in electrophotography, electrostatic recording and the like.

(Prior Art) In electrophotography, electrostatic recording, etc., an electrostatic latent image is developed with toner, and then the developed toner image is transferred to paper or the like to be a semi-permanent visible image and then fixed. . As a fixing method, a heat roll fixing method in which a toner image carried on paper or the like is passed between pressurized heat rolls and the toner is fused to the paper by heat and pressure is generally widely used. This fixing method naturally requires a toner that can obtain good fixing properties at a temperature as low as possible and at a high speed.

A toner (Japanese Patent Publication No. 46-12679) characterized by adding an ester of o-phthalic acid or m-phthalic acid has been known for the purpose of low-temperature fixing and high-speed fixing.

(Problems to be Solved by the Invention) However, in this toner, o-phthalic acid or m-
As the ester of phthalic acid increases, the fixability improves, but the storage stability of the toner becomes extremely poor. That is, with this toner, it was difficult to improve the fixability without sacrificing the storage stability of the toner.

The present invention solves the above problems and provides a toner for developing an electrostatic latent image which exhibits good fixability without deteriorating storage stability.

(Means for Solving Problems) The present invention relates to an electrostatic latent image developing toner containing 3 to 20% by weight of crosslinked polymer particles.

First, the crosslinked polymer fine particles used in the present invention will be described in detail.

In the present invention, the crosslinked polymer fine particles refer to spherical gel particles having a three-dimensional network molecular structure. The weight average particle diameter of the crosslinked polymer fine particles is preferably 40 to 150 nm. The crosslinkable polymer fine particles having a weight average particle diameter of less than 40 nm and the crosslinked polymer fine particles having a weight average particle diameter of more than 150 nm tend to lower the toner fixability.

The crosslinked polymer fine particles used in the present invention are obtained by polymerizing one or more kinds of monofunctional monomers and one or more kinds of crosslinking agents.

Examples of the monofunctional monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene and p-tert-butyl. Styrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, p
Styrene-based monofunctional monomers such as -n-decylstyrene, pn-dodecylstyrene, n-methoxystyrene, p-phenylstyrene, n-chlorostyrene and 3,4-dichlorostyrene, ethylene, propylene, Ethylene unsaturated monoolefins such as butylene and isobutylene, vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate. , Methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n acrylate
-Octyl; dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate,
Α-Methylene aliphatic monocarboxylic acid esters such as stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, and in some cases acrylic acid , Vinyl ethers such as methacrylic acid, maleic acid, fumaric acid, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
2-hydroxyethyl methacrylate, 2-methacrylic acid
Acrylic acid or methacrylic acid derivatives such as hydroxypropyl, vinyl methyl ketones, vinyl hexyl ketone, vinyl ketones such as methyl isopropenyl ketone, N
-N-vinyl compounds such as vinylpyrrole, N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone,
Examples thereof include vinyl naphthalene salt.

As the crosslinking agent, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and their derivatives, allyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate,
2 or more of triethylene glycol triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, N, N-divinylaniline, divinyl ether, divinyl sulphite, etc. The polyfunctional crosslinking agent having a polymerizable unsaturated bond of is mentioned.

As the monofunctional monomer, a styrene monofunctional monomer, an acrylic acid derivative, a methacrylic acid derivative, or the like is used.
It is preferable to use an aromatic divinyl compound or the like as the cross-linking agent. In particular, when a styrenic monofunctional monomer is used as the monofunctional monomer and divinylbenzene is used as the cross-linking agent, a toner containing crosslinked polymer fine particles is obtained. The fixing property is particularly good, and the storage stability of the toner is also good, which is preferable.

The monofunctional monomer and the cross-linking agent constituting the cross-linked polymer particles are 0.1 to 50% by weight of the mono-functional monomer and 50 to 99 of the cross-linking agent.
It is preferable to add 9% by weight so that the total amount becomes 100% by weight. If the amount of the cross-linking agent is less than 0.1% by weight or more than 50% by weight, the fixability of the toner containing the obtained crosslinked polymer fine particles tends to be lowered.

The monofunctional monomer and the crosslinking agent are polymerized by aqueous suspension polymerization, emulsion polymerization or the like in the presence of a polymerization initiator or the like to obtain crosslinked polymer fine particles.

Among the crosslinked polymer fine particles, the microgel obtained by emulsion polymerization is particularly preferable because it is relatively easy to produce and various properties of the toner containing the microgel are excellent.

A monofunctional monomer and a cross-linking agent, as well as a surfactant and a polymerization initiator are used for producing the microgel.

Surfactants include anionic surfactants, cationic surfactants, nonionic surfactants and zwitterionic surfactants, but anionic surfactants can be used because emulsion polymerization can be performed stably. Agents are preferred.

Anionic surfactants include sodium lauryl sulfate, dodecylbenzene, sodium sulfonate, aerosol OT (trade name, manufactured by Wako Pure Chemical Industries, Ltd.), aerosol
MA-80 (trade name, manufactured by American Cyana Mitt Company, the same applies below), Surfactant 501, Aerosol 18, Aerosol AY-65 and the like.

Surfactants are used in order to stably continue emulsion polymerization.
8 to 15% by weight based on the total amount of monofunctional monomer and crosslinking agent
It is preferred to use.

As the polymerization initiator, it is preferable to use a water-soluble polymerization initiator. Water-soluble polymerization initiators include hydrogen peroxide water, sodium persulfate, potassium persulfate, ammonium persulfate, 2,2'-azobis (isobutyramide) dihydrate, 2,2'-azobis [2-methyl-N- (2 -Hydroxyethyl) propionamide], 2,2'-azobis {2
-Methyl-N- [1,1-bis (hydroxymethyl) ethyl] propionamide}, 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] Propionamide or the like can be used.

The polymerization initiator is preferably used in an amount of 0.3 to 5% by weight based on the total amount of the monofunctional monomer and the crosslinking agent from the viewpoint of the polymerization rate and economy.

Emulsion polymerization is performed by weighing the above materials, adding them to ion-exchanged water, stirring and heating. The weight ratio of the ion-exchanged water to the total amount of the monofunctional monomer and the cross-linking agent is from the viewpoint of heat generation removal during polymerization and prevention of aggregation and coalescence of microgels during polymerization.
Ion-exchanged water / total amount of monofunctional monomer and crosslinking agent is 3/1
It is preferably within the range of -20/1, and more preferably within the range of 5 / 1-10 / 1. Emulsion polymerization is 20 to 90
It is preferably carried out at 40 to 70 ° C. The surfactant is repeatedly removed by washing with water, alcohol, dimethylformamide or the like after the polymerization of the microgel.

The crosslinked polymer fine particles used in the present invention are contained in the toner in an amount of 3 to 20% by weight based on all toner components. If it is less than 3% by weight, the effect of improving the fixing property of the toner is hardly recognized, and if it exceeds 20% by weight, the effect of improving the fixing property of the toner is hardly recognized.

In the present invention, in order to include the crosslinked polymer fine particles in the toner, a method for producing the binder resin by dispersing the crosslinked polymer fine particles in the monomer which is the binder resin component, the binder resin and the crosslinked polymer fine particles Are mixed in a solution, or the binder resin and the crosslinked polymer fine particles are melt-kneaded in advance, and then mixed with the binder resin in advance, and then mixed with other toner components and melt-kneaded. It can be carried out by a method in which it is mixed with other toner components all at once and melt-kneaded.

Among these, it is preferable to preliminarily mix the crosslinked polymer fine particles with the binder resin from the viewpoint that the obtained toner has a particularly good fixing property. In particular, the crosslinked polymer fine particles are preferably mixed in the monomer as the binder resin component. It is preferable to disperse the above to produce a binder resin.

The binder resin used in the toner for developing an electrostatic latent image of the present invention includes the following.

(1) Monofunctional styrene derivatives such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate , Octyl acrylate, stearyl acrylate, lauryl acrylate, oleyl acrylate, cetyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, furfuryl acrylate,
Tetrahydrofurfuryl acrylate, glycidyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, (N, N-dimethylamino) ethyl acrylate, acrylic acid (N, N-
Monofunctional acrylic acid derivatives such as diethylamino) ethyl, morpholinoethyl acrylate, piperazinoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, stearyl methacrylate, methacrylic acid Lauryl, oleyl methacrylate, cetyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate. , (N, N-dimethylamino) ethyl methacrylate, (N, N-diethylamino) ethyl methacrylate, molybdenum methacrylate Monofunctional methacrylic acid derivatives such as holinoethyl, piperazinoethyl methacrylate and maleic anhydride, maleic acid, methyl maleate, dimethyl maleate, ethyl maleate, diethyl maleate, butyl maleate, dibutyl maleate, octyl maleate, maleic acid Dioctyl, glycidyl maleate, diglycidyl maleate, N-methyl maleic imide, N-ethyl maleic imide, N-propyl maleic imide, N-butyl maleic imide, N-hexyl maleic imide, N-octyl maleic acid Maleic acid derivatives such as imides, and one or more monofunctional vinyl monomers such as vinyl acetate and vinyl chloride, and in some cases, divinylbenzene, ethylene glycol diacrylate, ethylene Glycol dimethacrylate , Propylene glycol diacrylate, propylene glycol dimethacrylate, butylene glycol diacrylate, butylene glycol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate, Polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, 2,2
Bifunctional vinyl monomers such as bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate,
One or more trifunctional or higher vinyl monomers such as pentaerythritol tetramethacrylate are preferably blended in an amount of 0 to 1% by weight, and suspension polymerization, emulsion polymerization, using a known polymerization initiator, A vinyl polymer obtained by polymerization by a known polymerization method such as solution polymerization or bulk polymerization.

(2) Polyglycidyl ether or hexahydrophthalic acid obtained by reacting polychlorophenol such as bisphenol A, bisphenol F, phenol novolac, cresol novolac or polyhydric alcohol such as polyethylene glycol or hexanediol with epichlorohydrin , Epoxy resin such as polyglycidyl ester obtained from polycarboxylic acid such as terephthalic acid.

As commercially available products, Epicoat 1004 (trade name, manufactured by Ciel), Epicoat 1007 (trade name, manufactured by Ciel), Epicoat 1009 (trade name, manufactured by Ciel), Araldite GY6084
(Trade name, manufactured by Ciba Geigy, the same applies below), Araldite GY6097, Araldite GY6099, etc.

(3) Ethylene glycol, glycerin, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, propylene oxide adduct of bisphenol A, trimethylolethane, trimethylolpropane, pentaerythritol, etc. Polyester resin obtained by appropriately combining the polyhydric alcohol component and polybasic acid such as maleic acid, fumaric acid, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, trimellitic acid and pyromellitic acid.

The binder resin of the present invention is not limited to these, and other conventionally known resins can be used. Further, the binder resin can be used alone or in combination of two or more kinds. In the case of a two-component toner, the binder resin is 30 for all toner components.
It is preferable that the content of the magnetic toner is 96 to 96% by weight, and that of the magnetic toner is 20 to 67% by weight.

The binder resin is preferably a vinyl-based polymer because the molecular design can be manipulated in a wide range and various properties of the toner are good, and polystyrene, methyl methacrylate-butyl methacrylate copolymer, methyl methacrylate-acrylic is particularly preferable. Butyl acid copolymer, methyl methacrylate-methyl acrylate copolymer, styrene-methyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-butyl methacrylate copolymer and the like are preferable. Further, it is preferable that the glass transition temperature of the binder resin is adjusted to 40 ° C to 100 ° C because various characteristics of the toner are good.

The toner for developing an electrostatic latent image according to the present invention contains a colorant and / or magnetic powder. Coloring agents include carbon black, acetylene black, lamp black, graphite,
Black colorants such as iron black, aniline black, cyanine black, yellow lead, cadmium yellow, yellow iron oxide, titanium yellow, naphthol yellow, Hansa yellow, pigment yellow, benzidine yellow, permanent yellow, quinoline yellow lake, anthra pyrimidine yellow, etc. Yellow colorants, orange colorants such as permanent orange, balkanfurast orange, benzidine orange, indanthrene brilliant orange, iron oxide, amber, brown colorants such as permanent brown, red iron oxide, antimon red, permanent red, fire red, Brilliant Carmine, Lighthearted Toner, Permanent Carmine, Pyrazolone Red, Bordeaux, Helio Bordeaux, Rhodamine Lake, Thioindigo Red, Thioindi Red colorants such as maroon, cobalt violet, Fuasuto bio row de, purple colorants such as dioxazine bio-bract, cobalt blue, cerulean blue, metal-free phthalocyanine blue, phthalocyanine blue, indanthrene blue, blue colorants such as indigo,
There are green colorants such as chrome green, cobalt green, green gold, phthalocyanine green, polychrome brom copper phthalocyanine, etc. If heat decomposition resistance is required, carbon black, iron black, cyanine black, yellow iron oxide, titanium Yellow, Hansa Yellow, Benzidine Yellow, Permanent Orange, Balkan Huast Orange, Iron Oxide, Bengala, Fire Red, Light Hustled Toner, Permanent Carmine, Pyrazolone Red, Bordeaux, Thioindigo Marul, Cobalt Purple, Cobalt Blue, Cerulean Blue, Phthalocyanine blue, cobalt green, phthalocyanine green, polychrome bromide copper phthalocyanine and the like are particularly preferable. 1 to 60% by weight of these colorants in all toner components
It is preferably blended. If it is less than 1% by weight, coloring is insufficient, and if it exceeds 60% by weight, the fixing strength of the toner tends to decrease.

The magnetic powder is blended when the usage pattern is a one-component toner. Magnetic powders include metal powders of iron, manganese, nickel, cobalt, etc., aluminum, cobalt, steel, lead,
Alloys of metals such as magnesium, nickel, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and their mixtures, aluminum oxide, iron oxide, copper oxide, nickel oxide, oxidation Metal compounds containing metal oxides such as zinc, titanium oxide, magnesium oxide, and chromium oxide, or alloys that exhibit ferromagnetism when subjected to heat treatment, such as manganese-copper-aluminum and manganese-copper-tin whiskers. Can be used. The particle size of the magnetic powder is preferably 10 μm or less, and particularly preferably 1 μm or less. These magnetic powders are contained in the toner in an amount of 30 to 70% by weight. When magnetic powder is used, the above colorant may be further added, and the amount thereof is preferably 0 to 10% by weight in the toner.

Further, additives such as a charge control agent, a fluidity improving agent, a cleaning property improving agent, and an offset preventing agent can be used in the toner according to the present invention, if necessary.

Examples of charge control agents include chromium complexes of salicylic acid derivatives, spirone dyes, nigrosine dyes, fatty acid-modified nigrosine dyes, dibutyltin oxide, tetraalkylammonium halides, trialkylammonium halides, etc. It is preferably added in an amount of 0 to 10% by weight.

As fluidity improvers, Aerosil R972, silica D-17,
R-812, RA200H, RX-C (above, Nippon Aerosil Co., Ltd.,
Trade name), TARANOX 500 (manufactured by Tarco Co., Ltd.) and the like, and these are preferably added in an amount of 0 to 15% by weight based on all toner components.

As the cleaning property improver, zinc stearate,
Examples thereof include fatty acid metal salts such as calcium stearate and magnesium stearate, and these are preferably added in an amount of 0 to 10% by weight based on all toner components.

As anti-offset agents, low molecular weight polyolefins such as polyethylene and polypropylene, Casta Wax (manufactured by Ito Oil Co., Ltd.), Diamond Wax (manufactured by Shin Nippon Rika Co., Ltd.), Palm Asethi (manufactured by Nippon Oil & Fats Co., Ltd.)
Hoechstwax E, Hoechstwax-OP (above, manufactured by Hoxtactien Gezershyaft), ester wax such as Karnauba Wax, amide wax such as Hoechstwax C (manufactured by Hoxtactien Gezershaft), fatty acid metal salt Etc., and these are preferably added in an amount of 0 to 30% by weight based on all toner components.

In addition, any conventionally known additive can be blended.

In the present invention, the above various additives may be added alone or in combination.

Each of the above toner components is used so that the total amount becomes 100% by weight.

The materials described above can be mixed, for example, by the following method to produce a toner for developing an electrostatic latent image.

After preliminarily mixing the weighed materials with a W cone, a V blender, a Hensiel mixer, etc., they are kneaded with a pressure kneader, a Banbury mixer, a heat roll, an extruder, etc. at a temperature at which the resin melts. After cooling, feather mill,
Coarsely crush with a pin mill, pullerizer, hammer mill, etc. Then, it is sieved with an Akiyukatsu and Alpine classifier to adjust the particle size to preferably 5 to 30 μm.

When the crosslinked polymer particles are not previously mixed with the binder resin, they are mixed at the time of manufacturing the toner.

When the toner according to the present invention is used in two components, the toner and the carrier are combined to prepare a developer.

Carriers include flat shape, sponge shape, coin shape,
A coagulated or spherical iron powder, a surface of the iron powder coated with a thermoplastic or thermosetting resin such as Teflon, silicon, or vinyl, or a one-component toner according to the present invention is preferable. Furthermore, the carrier is adjusted in particle size, electric resistance, specific surface area, etc. according to the purpose of use.

The toner concentration of the two-component developer generally depends on the specific surface area of the carrier, and is 3 to 10% by weight when the carrier used has an irregular shape or a fine particle size, and 1 to 1 when the carrier has a spherical or coarse particle size. It is preferably 5% by weight.

(Function) In the toner for developing an electrostatic latent image of the present invention, by containing the crosslinked polymer fine particles, the fixability of the toner can be significantly improved without substantially lowering the storage stability of the toner. .

(Examples) Hereinafter, the present invention will be described in detail with reference to Examples.

Synthesis Example 1 (Preparation of styrene dispersion I of poly (styrene / divinylbenzene) -based microgel) Ion-exchanged water 300 g, sodium lauryl sulfate 3.5 g, and
2,2'-Azobis (isobutyramide) dihydrate 0.5
g was charged into a reaction vessel equipped with a stirrer, a nitrogen blowing tube, a thermocouple for temperature control, and a cooling tube, and dissolved well while stirring. Then, 29,7 g of styrene and 0.3 g of divinylbenzene (purity 55% by weight, ethylvinylbenzene about 40% by weight, unreacted mixture about 5% by weight, the same below) were added thereto, and the mixture was stirred at 80 ° C. for 4.5 hours. It was made to react. Then, the whole amount of this reaction solution was poured into 3,000 g of methanol to aggregate the microgel, and the mixture was stirred at 50 ° C. for 2 hours and then allowed to pass. The polymerization rate of this microgel is almost 100.
% By weight. Furthermore, after adding this vortex residue to 3,000 g of methanol and stirring at 50 ° C for 2 hours,
I made a mistake. The excess obtained in a wet state with methanol was put into 900 g of styrene, the mixed methanol was azeotropically distilled with styrene, and the styrene dispersion I of microgel (microgel content 12.5% by weight) was added. Obtained. The amount of methanol mixed in the styrene dispersion liquid I (measured by gas chromatography, the same applies hereinafter) was 0.05% by weight. The weight average particle diameter of the microgel (the sample is a styrene diluted product of Dispersion I) measured with a Submicron Sizer BI-90 (manufactured by Block Haven Instruments Corporation) was 93 nm.

Synthesis Example 2 (Preparation of Poly (styrene / divinylbenzene) -based Microgel Styrene Dispersion II) Microgel Styrene Dispersion I except that 27 g of styrene and 3 g of divinylbenzene were used instead of 29.7 g of styrene and 0.3 g of divinylbenzene. A styrene dispersion liquid II (microgel content: 20% by weight) of microgel was obtained in the same manner as in the preparation method of 1. The polymerization rate of this microgel is almost 10
It was 0% by weight. The amount of methanol mixed in Dispersion II is 0.0
It was 4% by weight. The weight average particle size of the microgel measured by the same apparatus as in Synthesis Example 1 (the sample is a dispersion liquid II diluted with styrene) was 49 nm.

Synthesis Example 3 (Preparation of Styrene / Acrylic Resin a) 10 g of a 5% by weight aqueous solution of polyvinyl alcohol and 300 g of ion-exchanged water were charged into a reaction vessel equipped with a stirrer, a nitrogen blowing tube, a thermocouple for temperature control, and a cooling tube. . Then, a mixture of 80 g of styrene in which 5 g of benzoyl peroxide was dissolved and 20 g of butyl acrylate was added, and the mixture was stirred with stirring.
The reaction was carried out at 0 ° C. for 5 hours. Polymerization rate is almost 100
% By weight. After cooling, draining, drying and crushing, styrene / acrylic resin a (hereinafter abbreviated as resin a)
I got The glass transition temperature of Resin a was 70 ° C. The glass transition temperature was measured using the thermo-mechanical analysis method under the conditions of penetration mode, load 70 gf, and heating rate 10 ° C / min.

Synthesis Example 4 (Preparation of styrene / acrylic resin b containing microgel) Resin a except that styrene dispersion I 80 g of microgel was used instead of 80 g of styrene in the method of preparing resin a
A styrene / acrylic resin b (hereinafter abbreviated as resin b) containing a microgel and having a polymerization rate of about 100% by weight was prepared in exactly the same manner as in (1) above. The glass transition temperature of resin b is 7
It was 2 ° C.

Synthesis Example 5 (Preparation of styrene / acrylic resin c containing microgel) Resin a except that 80 g of styrene dispersion liquid II of microgel was used in place of 80 g of styrene in the method of preparing resin a
Styrene / acrylic resin c containing microgel (hereinafter abbreviated as resin c) was prepared in exactly the same manner as in (1) above. The glass transition temperature of resin c was 75 ° C.

Synthesis Example 6 (Preparation of Styrene / Acrylic Resin d Containing Microgel) The preparation method of resin a is completely the same as the preparation method of resin a except that 50 g of styrene dispersion II of microgel and 30 g of styrene are used instead of 80 g of styrene. Similarly, a styrene / acrylic resin d (hereinafter abbreviated as resin d) containing a microgel and having a polymerization rate of about 100% by weight was prepared. The glass transition temperature of resin d was 71 ° C.

Synthesis Example 7 (Preparation of Styrene / Acrylic Resin e Containing Microgel) In the method of preparing resin a, except that 25 g of styrene dispersion II of microgel and 55 g of styrene were used instead of 80 g of styrene Similarly, a styrene / acrylic resin e (hereinafter abbreviated as resin e) containing a microgel and having a polymerization rate of about 100% by weight was prepared. The glass transition temperature of resin e was 70 ° C.

Synthesis Example 8 (Preparation of styrene / acrylic resin f containing dioctyl phthalate) The same as the method of preparing resin a except that 1.5 g of dioctyl phthalate and 78.5 g of styrene were used instead of 80 g of styrene in the method of preparing resin a. And the polymerization rate is almost 100
A styrene / acrylic resin f (hereinafter abbreviated as resin f) containing dioctyl phthalate by weight was prepared. Resin f
Had a glass transition temperature of 52 ° C.

Example 1 90% by weight of resin b and carbon black # 44 (trade name,
10% by weight of carbon black manufactured by Mitsubishi Kasei Co., Ltd. was dry-mixed and then melt-kneaded. Then, it was crushed using a jet mill and further classified to obtain a toner B having an average particle size of 14 μm.

A developer is prepared from 4% by weight of toner B and 96% by weight of EFV200 / 300 (trade name, iron oxide powder carrier manufactured by Nippon Iron & Powder Co., Ltd.), and a SELEX 1200 (trade name, copier manufactured by Copier) is prepared. ) Was used to prepare a solid image of unfixed 3 cm × 4 cm square toner on plain paper. Then, the toner image can be changed in roll temperature, the upper side is a Teflon coated roll, the lower side is a silicone rubber coated roll, and the pressure between the upper and lower rolls is 0.8 kgf.
Table 1 summarizes the results of examining the fixability of the toner image with respect to the temperature of the roll by passing it through a fixing device of / cm ² at a speed of 13 cm / s. The fixability was expressed by the image density retention rate obtained from the following formula.

D ₀ : Reflection density of fixed image D: Reflection density measured after peeling tape of fixed image part and measured after peeling Also, accelerated test of storage stability of toner B (when temperature and humidity are applied The test is conducted by visually observing whether or not the powder state can be maintained) at a temperature of 50 ° C and a humidity of
It was left standing for 27 hours at 27%, 43%, 66% and 91%, and the results are summarized in Table 1.

Example 2 Toner C was prepared in the same manner as in Example 1 except that Resin C was used instead of Resin b, and the fixing property and storage stability of Toner C were prepared in the same manner as in Example 1. Was evaluated and summarized in Table 1.

Example 3 Toner D was prepared in the same manner as in Example 1 except that resin d was used in place of resin b in Example 1, and fixing performance and storage stability of toner D were performed in the same manner as in Example 1. Was evaluated and summarized in Table 1.

Example 4 Toner E was prepared in the same manner as in Example 1 except that resin e was used in place of resin b, and the fixing property and storage stability of toner E were measured in the same manner as in Example 1. Was evaluated and summarized in Table 1.

Comparative Example 1 Toner A was prepared in exactly the same manner as in Example 1 except that resin a was used in place of resin b in Example 1, and fixing and storage stability of toner A were performed in exactly the same manner as in Example 1. Was evaluated and summarized in Table 1.

Comparative Example 2 A toner F was prepared in the same manner as in Example 1 except that the resin f was used in place of the resin b, and the fixing property and storage stability of the toner F were measured in the same manner as in Example 1. Was evaluated and summarized in Table 1.

Stability: Images with an image density retention rate of 90% or more were rated as O, and those with less than 90% were rated as X.

Storage stability: Leave for 18 hours at a temperature of 50 ° C. ○ indicates a good powder state without lumps, and × indicates many lumps.

(Effect of the Invention) The toner for developing an electrostatic latent image according to the present invention has good fixability without impairing storage stability.

Claims (5)

[Claims] 1. A toner for developing an electrostatic latent image, which comprises 3 to 20% by weight of crosslinked polymer particles. 2. A crosslinked polymer fine particle having a weight average particle diameter of 40 to
The toner for developing an electrostatic latent image according to claim 1, which has a particle size of 150 nm. 3. Crosslinked polymer fine particles are composed of 50 to 50 monofunctional monomers.
100% by weight of 99.9% by weight and 0.1-50% by weight of crosslinking agent
The toner for developing an electrostatic latent image according to claim 1 or 2, which is obtained by blending and polymerizing so that 4. The crosslinked polymer fine particles are composed of a styrenic monofunctional monomer as a monofunctional monomer and divinylbenzene as a crosslinking agent.
Item 4. The toner for developing an electrostatic latent image according to item. 5. The cross-linked polymer fine particles are microgels obtained by emulsion polymerization of a monofunctional monomer and a cross-linking agent, as claimed in claim 1, claim 2, claim 3 or claim 4. Toner for developing electrostatic latent images.