JP2935271B2 - 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. If a hydrocarbon solvent is used as the carrier liquid and this fixing method is adopted, the amount of solvent gas emitted per unit number will slightly decrease compared to the conventionally used atmosphere fixing method, but it will be possible to copy many sheets at high speed. When this occurs, a large amount of solvent gas is generated. Further, in order to enhance the releasability between the toner layer and the fixing roller, it was necessary to apply silicone oil. An object of the present invention is to improve the above-mentioned drawbacks by using a silicone-based solvent as a carrier liquid, increase the cohesive force 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. In addition, as an aliphatic hydrocarbon solution, petroleum hydrocarbons such as cyclohexane, n-hexane, n-heptane, n-octane, n-nonane, isooctane, isododecane, ligroin, and a mixture thereof (as commercial products, Isopar manufactured by Exxon Chemical Co., Ltd.) E, G, H, L, K, V
And Shell Petrochemical Shellsol 71, Solbesso 15
0, etc.) are used as appropriate. In order to reduce the transfer solvent, the carrier liquid is 10 cst or less,
Preferably, it is 3 cst or less. As means for increasing the cohesive force of the toner, a styrene monomer (a), an acrylic acid or methacrylic ester monomer (b), and an acrylic or methacrylic acid derivative having a hydroxyl group and a dicarboxylic acid are used as toner resin components. It is possible to use a polymer crosslinked via zinc obtained by reacting a copolymer having a structural unit of a half-ester compound (c) having a structure obtained by an esterification reaction with an acid and a zinc compound. No. In the present invention, the ratio of the copolymer to the zinc compound is about 0.1 to 10 mol, preferably about 0.3 to 5 mol, per 1 mol of the ester compound. Specific examples of the styrene monomer (a) used in the present invention include, in addition to styrene, for example, o-methylstyrene, m-methylstyrene, p-methylstyrene, a-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, p -N-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,
4-dichlorostyrene and the like can be mentioned. Specific examples of the acrylic acid or methacrylate monomer (b) used in the present invention include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, and n-acrylate. Octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid In addition to alkyl esters of acrylic acid or methacrylic acid such as stearyl, 2-chloroethyl acrylate,
Phenyl acrylate, α-methyl methyl acrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like, ethyl acrylate, propyl acrylate,
Butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like are particularly preferably used. The carboxyl group-containing compound as the half ester compound (c) used in the present invention includes, for example, malonic acid,
It is obtained by an esterification reaction of an aliphatic dicarboxylic acid such as succinic acid or glutaric acid or an aromatic dicarboxylic acid such as phthalic acid with a derivative of acrylic acid or methacrylic acid containing a hydrogen group. The dicarboxylic acid may be substituted with a hydrogen atom by a halogen element, a lower alkyl group, an alkoxy group, or the like, or may be an acid anhydride. As the derivative of the hydroxyl group-containing acrylic acid or methacrylic acid, one obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to the acrylic acid or methacrylic acid in an amount of 1 mol or 2 mol or more may be used. It may be a vidroxyalkyl ester obtained by subjecting a dihydric alcohol such as propylene glycol to an esterification reaction. The half ester compound (c) is represented, for example, by the following general formulas (1) to (4). (R ₁ and R ₂ are H or CH ₃ , m is 1 to 14, and n is 0 to 8.) (R ₁ , R ₂ , and m are the same as those in the general formula (1), and X represents H, a halogen group element, a lower alkyl group, or an alkoxy group.) (R ₁ represents H or CH ₃ , h represents 3 to 6, and j represents 0 to 8.) (R ₁ is H or CH ₃ , k is 3 to 6, Y is H, a halogen element, a lower alkyl group or an alkoxy group.) A preferred specific example of the half-ester compound (c) is monosuccinic acid. (Meth) acryloyloxyethyl ester, mono (meth) acryloyloxypropyl succinate, mono (meth) acryloyloxyethyl glutarate, mono (meth) acryloyloxyethyl phthalate, mono (meth) acryloyloxypropyl phthalate Esters and the like. 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
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 Bordeaux 10B. . 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) Synthetic polyesters such as polypropylene, modified polyesters thereof, carnauba wax, montan wax, candelilla wax, sugar cane wax, oculy wax, beeswax, wood wax, natural wax such as wax, ester gum, hardened rosin, etc. 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, [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. Silicon material with acroyl group to improve dispersibility in silicon solvent, LS4080 manufactured by Shin-Etsu Silicon
And the like, or similarly, AK-5 manufactured by Toa Gosei Chemical Co., Ltd., TM0701, FM0711, FM0721, FM07 manufactured by Chisso Corporation.
25 may be used. The coloring material, the resin, and the carrier liquid are put into a dispersing machine such as a ball mill, a kitty mill, a disc mill, and a pin mill, and dispersed and kneaded to prepare a concentrated toner, which is dispersed in the carrier liquid of the present invention. To obtain a kneading agent.

EXAMPLES In the following examples, "parts" all mean "parts by weight". Production Example 1 2 400 g of toluene was placed in a separable flask, the air was replaced with nitrogen gas, the system was heated to the boiling point of toluene, and while stirring, 750 g of styrene, 200 g of n-butyl acrylate, and monoacryloyl succinate were stirred. Solution polymerization was performed while a mixture of 50 g of oxyethyl ester and 10 g of benzoyl peroxide as a polymerization initiator was added dropwise over 2.5 hours. After the addition of the mixture was completed, the mixture was aged for 1 hour while stirring at the boiling point of toluene, and 14.1 g of zinc oxide was added. Next, while gradually raising the temperature of the system to 180 ° C., the solvent was removed from the toluene under reduced pressure, and styrene-acrylic acid n
A reaction polymer of -butyl-succinic acid monoacryloyloxyethyl ester copolymer and zinc oxide was obtained. Production Example 2 38 g of zinc acetate in place of 14.1 g of zinc oxide in Production Example 1
A reaction polymer was obtained in exactly the same manner except that was used. Example 1 70 parts of the resin of Production Example 1 30 parts of carbon black (Printex V manufactured by Degussa) were kneaded with a two-roll mill at 90 ° C. for 30 minutes and 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 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 (Shin-Etsu Silicone Co., Ltd., viscosity
3cst) Diluted in 1 to obtain a developer. Example 2 57 parts of resin of Production Example 2 250 parts (polyethylene manufactured by Sanyo Chemical Co., Ltd.) 8 parts 35 parts of MA60 (carbon black manufactured by Mitsubishi Kasei Co., Ltd.) 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) 200 parts of Isopar H 10% solution of copolymer 100 parts of Isopar H was placed in a ball mill and dispersed for 24 hours, and then 300 parts of Isopar H was added and dispersed for 1 hour to obtain a concentrated toner. In the same manner as in Example 1, a developer was prepared. Example 3 60 parts of resin of Production Example 2 AC400A (manufactured by Allied Chemical) 10 parts Regal 400 (manufactured by Cabot) 30 parts were kneaded and pulverized with a flasher at 90 ° C. for 30 minutes. Thereafter, a developer was prepared in the same manner as in Example 1. 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 provides a temperature range within a range in which 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.The result was 300 to 360 ppm for the developer using only Isopar H as the carrier liquid, whereas the development according to the present invention Each of the preparations was halved to 80 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 Kazuhiko Umemura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-64-50063 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/13

Claims (1)

(57) [Claims] A liquid developer for an electrostatic image, 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. Styrene monomer as a part of the resin, acrylic acid or methacrylic acid ester monomer, and a half ester having a structure obtained by an esterification reaction of a styrene acid or methacrylic acid derivative containing a hydroxyl group with a dicarboxylic acid A liquid developer for an electrostatic image, comprising a polymer crosslinked via zinc obtained by reacting a copolymer having a compound as a constitutional unit with a zinc compound.