JP2826851B2 - Liquid developer for electrostatic image - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial fields]

The present invention relates to a hot roll fixing liquid developer used for electrophotography, electrostatic recording, electrostatic printing, and the like.

[Prior art]

As a liquid developer for heat roll fixing roll,
Nos. 301966 to 301969 and 64-50062 to 50067 and 64
-52167 and 64-142560 to 142561.
Since these are carrier liquids mainly composed of aliphatic hydrocarbons, the oil of the aliphatic hydrocarbons is discharged out of the copying machine, and silicone oil must be supplied for application to a fixing roll. There have been problems such as a complicated copying machine and an increase in the number of consumables.

[Object of the present invention]

An object of the present invention is to reduce a hydrocarbon solvent gas generated from a copying machine. In a hot roll fixing device using a liquid developer, an oil applying device can be removed from the fixing roll, and the trouble of oil supply can be eliminated. By mixing incombustible liquids at a certain ratio, danger such as ignition is reduced.

Configuration of the Invention

In recent years, a hot roll fixing method has been proposed as a fixing method of a liquid developer having high thermal efficiency and capable of high-speed fixing. When a hydrocarbon solvent is used as the carrier liquid and this fixing method is employed, the amount of solvent gas discharged per unit number is slightly reduced as compared with the conventionally used atmosphere fixing method, but a large number of copies were made at high speed. Sometimes a large amount of solvent gas is generated. Further, in order to increase the releasability between the toner layer and the fixing roll, it was necessary to apply silicone oil. An object of the present invention is to use a silicone-based solvent as a carrier liquid, improve the above-mentioned drawbacks, increase the cohesive strength of the toner, and prevent so-called "hot offset". As the silicone solvent used in the present invention, KF
96 (Shin-Etsu Silicon), SH200, SH344 (Toray Silicon),
TSF451 (Toshiba Silicon) and the like, and decamethyltetrasiloxane, octamethyltrisiloxane and the like may be used. As the aliphatic hydrocarbon solution, petroleum hydrocarbons such as cyclohexane, n-hexane, n-heptane, n-octane, n-nonane, isooctane, isododecane, ligroin, and mixtures thereof (as commercial products, Isopar manufactured by Exxon Chemical Co., Ltd.) E, G, H, L, K, V
Shell Shell 71, Solbesso 150, and Shell Oil
And the like are used as appropriate.
In order to reduce the amount of the transfer agent, the carrier liquid should be 10 cst or less, preferably 3 cst or less. In the present invention, as a means for increasing the cohesive strength of the toner, a resin made of a polymer of a vinyl monomer containing a crosslinking agent monomer is used. Examples of the vinyl monomer for obtaining a weight used as a binder resin in the present invention include, for example, styrene,
o-methylstyrene, m-methylstyrene, p-methylstyrene, a-methylstyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene, p
-Tert-butylstyrene, pn-hexylstyrene,
pn-octyl styrene, pn-nonyl styrene,
pn-decylstyrene, pn-dodecylstyrene,
Styrene monomers such as p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene are preferred. In addition, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl acetate, vinyl propionate, and vinyl benzoate And vinyl esters such as vinyl butyrate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate , Stearyl acrylate, 2-butyl acrylate, phenyl acrylate, methyl a-chloroacrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate , A-methylene aliphatic monocarboxylic esters such as lauryl taacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, and dimethylaminoethyl methacrylate; acrylic acids such as acrylonitrile, methacrylonitrile, and acrylamide Or methacrylic acid derivatives; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; N-vinyl pyrrole;
N-vinyl carbazole, N-vinyl indole, N-
N-vinyl compounds such as vinylpyrrolidone; vinylnaphthalenes and others. These monomers may be used alone or in combination of two or more, or may be used in combination to give a copolymer by polymerization. The crosslinking agent monomer used together with the monomer as described above,
Compounds mainly containing two or more polymerizable double bonds, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof, for example, diethylene glycol, diethylene glycol methacrylate, triethylene glycol methacrylate , Trimethylolpropane triacrylate, acrylic methacrylate, t-butylaminoethyl methacrylate, tetramethylene glycol dimethacrylate, 1,
All divinyl compounds such as diethylenic carboxylic acid esters such as 3-butanediol dimethacrylate, ethylene glycol dimethacrylate and tetramethylolmethane tetraacrylate, N, N-divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone And compounds having three or more vinyl acids can be used alone or in combination. The ratio of these crosslinking agent monomers to all monomers is 0.005% by weight or more, usually 20% by weight or less, and preferably in the range of 0.1 to 5% by weight. When this proportion is less than 0.005% by weight, the molecular weight of the obtained polymer does not increase, and the toner has a low offset generation temperature. When this ratio increases, the minimum fixing temperature increases, but the limit is not limited to 20% by weight. For example, if a chain transfer agent or the like is used, the above ratio can be increased to more than 20% by weight. Colorants that can be used in the present invention include Printex V, Printex U, Printex G, Special Black 15, Special Black 4, Special Black 4-B (manufactured by Degussa), Mitsubishi # 44, # 30, MR -1
1. MA-100 (Mitsubishi Kasei), Raven 1035, Raven 1252, Newspect II (Colombia Carbon), Legal 400, 600, Black Pearl 900, 110
Inorganic pigments such as 0, 1300, Mogar L (from Cabot) and phthalocyanine blue, phthalocyanine green, sky blue, rhodamine lake, malachite green lake, methyl violet lake, peacock blue lake, naphthol green B, naphthol green Y, naphthol green Yellow S, naphthol red,
Lisor First Yellow 2G, Permanent Red 4
Organic pigments such as R, Brilliant First Scarlet, Hansa Yellow, Benzidine Yellow, Lisor Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Permanent Red F5R, Pigment Scarlet 3B Indigo, Thioindigo Oil Pink and Bold-10B. Can be The pigment can be processed by kneading and pulverizing the above pigment with the resin by using a two-roll mill, a kneader flasher or the like. Further, the following resin may be used together with the above resin. Eastman Chemical (N-10, N-11, N-12, N-14, N-34, N-45, C-10, C-1
3, C-15, C-16, E-10, E-11, E-12, E-14, E-15) manufactured by Mitsui Petrochemical Co., Ltd. (110P, 220P, 220MP, 820MP, 410MP, 210MP, 310MP, 405MP, 20
0P, 4202E, 4053E) Sanyo Chemical (131P, 151P, 161P, 171P, E300, E250P) Sasol (H1, H2, A1, A2, A3, A4) BASF (OA WAX, A WAX) manufactured by Petrolite (BARECO 500, 2000, E-730, E-2018, E-202
0, E-1040, Petronaba C, C-36, C-
400, same C-7500) Hoechst (PE580, PE130, PED121, PED136, PED153, PED521, PED522, P
ED534) manufactured by Union Carbide (DYNI, DYNF, DYNH, DYNJ, DYNK) Monsanto (ORUZON 805,705,50) Dupont (ALATHON 3,10,12,14,16,20,22,23) Allied Chemical Company (AC polyethylene 6,6A, 615) Mitsui Polychemical Company (Evaflex 150,210,220,250,260,310,360,410,42
0,450,460,550,560), natural polyesters such as carnauba wax, montane wax, candelilla wax, sugar cane wax, ocully wax, beeswax, wood wax, nuka wax, ester gum, and cured rosin. Such as natural resin, natural resin modified maleic resin, natural resin modified phenolic resin,
A modified natural resin such as a modified natural resin polyester resin, a modified natural resin pentaerythritol resin, or an epoxy resin can be used in combination. The dispersing resin preferably used in combination in the present invention includes (R ₁ represents H or CH ₃ , n represents an integer of 6 to 20) and a vinyl monomer A represented by the following formula: (R ₁ is H or CH ₃ , R ₂ is H, C _n H _{2n + 1} [n = 1 to 5], C ₂ H ₄ OH, Or C ₂ H ₄ N (C _m H _{2m + 1} ) ₂ [m = 1 to 4]. A) a vinyl monomer represented by the formula: vinyl pyridine, vinyl pyrrolidone, ethylene glycol dimethacrylate,
Styrene, divinylbenze, one kind of each of the monomers B selected from vinyltoluene, or several kinds of copolymers,
A graft copolymer. In addition, LS4080 manufactured by Shin-Etsu Silicon Co., Ltd.
Or the like, or similarly, AK-5 manufactured by Toa Gosei Chemical Co., Ltd., TM0701, FM0711, FM0721, FM07 manufactured by Chisso Corporation.
25 may work. Put these coloring materials, resin and carrier liquid into dispersing machines such as ball mill, kitty mill, disk mill, pin mill, etc.
A developer can be obtained by dispersing and kneading to prepare a concentrated toner and dispersing the same in the carrier liquid of the present invention.

【Example】

In the following examples, "parts" all mean "parts by weight". Production Example 1 Starting from 2,2-azobis- (2,4-dimethylvaleronitrile) a polymerizable composition in which the weight ratio of styrene, n-butyl acrylate, and ethylene glycol dimethacrylate was 80: 20: 1. A crosslinked copolymer having a softening point of 135 ° C., usually obtained by polymerization by a suspension polymerization method. Production Example 2 A polymerizable composition obtained by polymerizing styrene, n-butyl acrylate, and ethylene glycol dimethacrylate at a polymerization ratio of 85: 15: 0.5 was converted to 2,2-azobis- (2,4-dimethylvaleronitrile). A crosslinked copolymer having a softening point of 134 ° C. obtained by polymerization by an ordinary suspension polymerization method as an initiator. Production Example 3 A polymerizable composition having a weight ratio of styrene, n-butyl acrylate, ethylene glycol dimethacrylate, and a-methylstyrene of 80: 20: 5: 7 was obtained in the same manner as the resin of Production Example 1. Crosslinked copolymer having a softening point of 140 ° C. Production Example 4 A polymerizable composition containing styrene, n-butyl acrylate, and trimethylolpropane triacrylate in a polymerization ratio of 80: 20: 0.5 was 2,2-
A crosslinked copolymer having a softening point of 138 ° C., obtained by polymerizing azobis- (2,4-dimethylvaleronitrile) by an ordinary suspension polymerization method. Example 1 70 parts of the resin of Production Example 1 carbon black (Printex manufactured by Dexa Corporation) 30 parts The mixture was kneaded with two rolls and then ground. 50 parts of the pulverized product lauryl methacrylate / methyl methacrylate / methacrylic acid / glycidyl methacrylate (80/10 /
5/5) 100 parts of Isopar H 20% solution of copolymer 100 parts of Isopar H (trade name of EXXSON) was put in a ball mill and dispersed for 24 hours. Then, 300 parts of Isopar H was further added and dispersed for 1 hour. This was a concentrated toner. Take 200g of this, KF96 (made by Shin-Etsu Silicon, viscosity 3cs
t) Diluted in 1 to obtain a developer. Example 2 57 parts of the resin of Production Example 2 250 P (polyethylene manufactured by Sanyo Chemical Co., Ltd.) 8 parts MA60 (carbon black manufactured by Mitsubishi Kasei Co., Ltd.) 35 parts were kneaded with a flasher and then pulverized. 60 parts of the pulverized product stearyl methacrylate / methyl methacrylate /
Methacrylic acid / hydroxymethyl methacrylate (85/7
/ 4/4) Isopar H 10% solution of copolymer 200 parts Isopar H 100 parts A developer was obtained in the same manner as in Example 1. Example 3 60 parts of resin of Production Example 3 AC400A (manufactured by Allied Chemical) 10 parts Regal 400 (manufactured by Cabot) 30 parts were kneaded and pulverized with a flasher. Thereafter, a developer was prepared in the same manner as in Example 1. Comparative Examples Comparative Examples 1 to 3 were obtained in the same manner as in Examples 1 to 3, except that the diluent was ISOPAR H. An oil-less fixing test was performed using a testing machine in which the fixing unit of Ricoh CT5085 was modified to a hot roll fixing. The results are as shown in the following table. From the above results, it is apparent that the developer of the present invention has a temperature range within a range in which the heat roller can be fixed without showing the offset phenomenon, and the hot roll can be fixed. In a closed room, continuous copying was performed using a test copying machine, and the solvent gas concentration was measured.When the comparative developer was used, the concentration was 300 to 360 ppm, and in the case of the developer of the present invention, 80 to 300 ppm. It was halved to 150 ppm.

【effect】

By using the developer of the present invention, hot roll fixing can be performed without causing an offset phenomenon without applying oil to the fixing roll, and high-speed, low-energy fixing can be performed with a compact copying machine. . Also, the amount of hydrocarbon-based gas generated from the copying machine was reduced.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hidemi Uematsu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (56) References JP-A-50-80136 (JP, A) JP-A Sho 63-4249 (JP, A) JP-A-63-301967 (JP, A) JP-B-41-6396 (JP, B1) JP-B-40-26990 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/13 G03G 9/125

Claims (1)

(57) [Claims] An electrophotographic liquid developer comprising toner particles comprising a colorant and a resin dispersed in a high-resistance low-dielectric-constant carrier liquid containing a silicon-based solvent as a main component. Liquid developer for electrostatic images, characterized by containing a vinyl polymer containing 0.005% by weight or more of a crosslinking agent monomer based on all monomers.