JP2829758B2 - 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 gas of the aliphatic hydrocarbons is discharged out of the copying machine, and it is necessary to supply silicone oil for coating on a fixing roll. However, 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, the oil applying device can be removed from the fixing roll, and the trouble of oil supply can be saved. By mixing incombustible liquids at a certain ratio, danger such as ignition is reduced.

In recent years, heat roll fixing 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 for the carrier liquid and this fixing method is adopted,
Although the amount of solvent gas discharged per unit number is slightly reduced as compared with conventionally used atmosphere fixing, a large amount of solvent gas is generated when a large number of copies are made at high speed. Also,
In order to improve 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 improve the above-mentioned drawbacks by adding a fluorine-based solvent as a carrier liquid, increase the cohesive force of the toner, and prevent so-called "hot offset". Fluorinated solvents used in the present invention include Fluorinert FC-77, FC-43, FC-70 (manufactured by Sumitomo 3M), Aflude, E-10, E-16, and E-18 (manufactured by Asahi Glass Co., Ltd.) Made)
And the like. KF96 (Shin-Etsu Silicon), SH20
0, SH344 (Toray Silicon), TSF451 (Toshiba Silicon) and the like, and decamethyltetrasiloxane, octamethyltrisiloxane and the like may be used. Also,
Petroleum hydrocarbons such as cyclohexane, n-hexane, n-heptane, n-octane, n-nonane, isooctane, isododecane, ligroin, and a mixture thereof as an aliphatic hydrocarbon solution (Exoper Chemical Co., Ltd. G, H, L, K, V, Shell Sole 71, Solvesso 150, etc., manufactured by Shell Petroleum Co., Ltd.). 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, for example, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide vinyl fluoride; vinyl acetate, vinyl propionate, vinyl benzoate, Vinyl esters such as butyric vinyl; 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 , Lauryl acrylate, methacrylic acid 2
-A-methylene aliphatic monocarboxylic esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate;
Acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide; 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 compounds such as -vinylpyrrole, N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinylnaphthalenes and others. These monomers may be used alone or in combination of two or more, or may be used in a combination to be polymerized to give a copolymer. 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. However, the limit is not limited to 20% by weight.
It is also possible to make it higher than% 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 (Columbia Carbon), Legal 400, 660, Black Pearl 900, 110
0, 1300, inorganic pigments such as Mogar L (from Cabot Corporation) and phthalocyanine blue, phthalocyanine green, sky blue, rotamin lake, malachite green lake, methyl violet lake, peacock blue lake, naphthol green B, naphthol green Y, Naphthol 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 KASEI (131P, 151P, 161P, 171P, E300, E250P) CERSOL (H1, H2, A1, A2, A3, A4) BASF (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) Synthetic polyester, polypropylene and its modified products, carnauba wax, montan wax, candelilla wax, sugar cane wax, ocully wax, natural wax such as beeswax, wood wax, nuka wax, ester gum, cured rosin, etc. Natural resin, natural resin modified maleic acid resin, natural resin modified phenolic resin,
A modified natural resin such as a natural resin-modified polyester resin, a natural resin-modified pentaerythritol resin, or an epoxy resin can be used in combination. Further, the dispersing resin preferably used in combination in the present invention is represented by a general formula (R ₁ represents H or CH ₃ , n represents an integer of 6 to 20) and a vinyl monomer A represented by the following general 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, [M = 1 to 4]. A) a vinyl monomer represented by the formula: vinyl pyridine, vinyl pyrrolidone, ethylene glycol dimethacrylate,
Each of the monomers B selected from styrene, divinylbenzene, and vinyltoluene may be used alone, or several types of copolymers and graft copolymers may be used. When a silicone solvent is contained as a carrier liquid, an acroyl group-containing silicon material such as LS4080 manufactured by Shin-Etsu Silicon Co., Ltd. may be copolymerized in order to increase dispersibility, and similarly, AK-5 manufactured by Toa Gosei Chemical Co., Ltd. Made by Chisso
TM0701, FMO711, FM0721, and FM0725 may be used. 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" represents all "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 containing styrene, n-butyl acrylate, and ethylene glycol dimethacrylate in a weight ratio of 85:15; 0.5 was prepared using 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 polymer 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-acrylic acid acrylate, butyl and trimethylolpropane triacrylate in a weight ratio of 80: 20: 0.5 is 2,2-azobis- (2,4-dimethylvaleronitrile). A cross-linked copolymer having a softening point of 138 ° C., obtained by polymerizing a polymer by an ordinary suspension polymerization method, using as an initiator. Example 1 70 parts of the resin of Production Example 1 30 parts of carbon black (Printex manufactured by Degussa Co.) 30 parts were kneaded with two rolls and then pulverized. 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 200 parts of Isopar H (trade name of EXXSON) is placed in a ball mill and dispersed for 24 hours. Then, 300 parts of Isopar H is further added and dispersed for 1 hour. And Take 200g of this, 50% FC-72 (Sumitomo 3M) and KF96
(Shin-Etsu Silicon, viscosity 3cst) Diluted in mixed solvent 1 with 50% 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. As is clear from the above results, the developer of the present invention has a temperature range within a range where the heat roller can be fixed without showing an offset phenomenon, and it can be seen that the heat roller 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, it is possible to perform hot roll fixing without causing offset development without applying oil to the fixing roll, and high-speed, low-energy fixing is possible with a compact copying machine. . Also, the amount of hydrocarbon-based gas generated from the copying machine was reduced.

Continuation of the front page (72) Inventor Hidemi Uematsu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-63-301967 (JP, A) JP-A-59-114549 (JP, A) JP-A-59-114550 (JP, A) JP-A-60-254055 (JP, A) JP-A-59-100115 (JP, A) JP-A-61-112161 (JP, A) Kaisho 50-80136 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03G 9/125 G03G 9/13

Claims (1)

(57) [Claims] A toner liquid comprising a colorant and a resin is dispersed in a high-resistance low-dielectric-constant carrier liquid comprising a mixed liquid of a fluorine-based solvent, an aliphatic hydrocarbon solvent and / or a silicone-based solvent. Liquid developer for electrostatography,
A liquid developer for an electrostatic image, comprising a vinyl polymer containing 0.005% by weight or more of a crosslinking agent monomer based on all monomers as the resin component.