JP2826873B2 - 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 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. In addition, it was necessary to apply silicone oil to improve the releasability between the toner layer and the fixing roll. 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-40, FC-43, FC-70 (all manufactured by Sumitomo 3M), Aflud, E-10, E-16 and E-18. (Manufactured by Asahi Glass Co., Ltd.). Silicone solvents that may be used at the same time include KF96 (Shin-Etsu Silicon), SH200, SH344 (Toray Silicon), TSF451 (Toshiba Silicon), and other decamethyltetrasiloxane, octamethyltrisiloxane, etc. May be used. Also, cyclohexane as an aliphatic hydrocarbon solution,
Petroleum hydrocarbons such as n-hexane, n-heptane, n-octane, n-nonane, isooctane, isododecane, ligroin, and mixtures thereof (as commercial products, Isopar E, G, H, L, K, manufactured by Exxon Chemical Co., Ltd.) V, Shell Sole 71, Solbesso 150, etc., manufactured by Shell Sekiyu KK). 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, the toner resin component contains a vinyl-based weight body having a weight average molecular weight (Mw) / number average molecular weight (Mn)> 4. Preferably, a toner having good fixing properties can be obtained by using a weight body having Mw / Mn> 10 and Mw ≧ 100,000 as a toner resin, and further, the polymer is reacted with a decomposable metal compound. When lightly crosslinked, the molecular weight distribution becomes wider, and the toner can have offset resistance while keeping the minimum fixing temperature low. As the decomposable metal compound used in the present invention, those containing the following metal ions can be used. Examples of the metal ion include metal ions having a valence of 1 or more. Suitable one
Na + in the valence metal ions, Li +, Cs +, Ag +, Hg +, include Cu +, suitable divalent metal ions ^{Ba 2 +, Mg 2 +,} Ca 2 +, Hg
² +, Sr ² +, Pb ² +, Fe ² +, Co ² +, Ni ² +, Zn ² + and the like. Suitable trivalent metal ions include Al ³ +, Se ³ +, Fe
³ +, Co ³ +, Ni ³ +, Cr ³ +, Y ³ + and the like. Among the metal ion compounds as described above, the more decomposable, the better the effect. Polymers that react with the decomposable metal compound of the present invention generally include carboxyl groups, carbonyl groups, ether groups, thioether groups, amino groups, amide groups, and the like.
Among these, a polymer containing a carboxyl group shows the best reactivity. Examples of the carboxyl group-containing monomer for synthesizing a vinyl group polymer include acrylic acid,
Acrylic acid such as methacrylic acid, α-ethylacrylic acid, crotonic acid and α- or β-alkyl derivatives thereof,
Unsaturated dicarboxylic acids such as fumaric acid, maleic acid and ditraconic acid and monoester derivatives thereof, and the like, and the monomer copolymerizable with the carboxyl group-containing monomer include monocarboxylic acid derivatives having a double bond;
For example, diester derivatives of dicarboxylic acids having a double bond such as dibutyl maleate, dimethyl maleate and the like; vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate and the like; for example, ethylene, propylene, butylene and the like Ethylene-based olefinic acids; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; and vinyl benzene, divinyl naphthalene, etc. Aromatic divinyl compounds such as carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butanedimethyl dimethacrylate, etc. There divinyl aniline, divinyl ether, divinyl sulfide, and compounds having divinyl compound and three or more vinyl groups such as divinyl sulfone. 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, Risor 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, C1-13, C-1
5, 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 polyester, polypropylene and its modified products, carnauba wax, montan wax, candelilla wax, natural waxes such as sugar cane wax, ocully wax, beeswax, wood wax, nuka 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 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: Represented by a vinyl monomer and 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 silicon solvent is contained as a carrier liquid, a silicon material having an acroyl group to increase dispersibility,
Shin-Etsu Silicon Co., Ltd. LS4080 etc. may be copolymerized. Similarly, Toagosei Chemical Co., Ltd. AK-5, Chisso Co., Ltd.
0701, FM0711, 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" all mean "parts by weight". Production Example 1 40 parts of toluene were placed in a separable flask, and 75 parts of styrene, 20 parts of butyl methacrylate, and 5 parts of maleic acid were added.
And 0.5 parts of divinylbenzene, and the gas phase was replaced with nitrogen gas.Then, the temperature was maintained at 80 ° C. The mixture was added dropwise and stirred at 80 ° C. for another 10 hours. Subsequently, 5 parts of a toluene solution containing 0.3 parts of benzoyl peroxide was added dropwise, the temperature was further raised to 90 ° C., and the temperature was maintained for 5 hours to complete the polymerization. After cooling, the polymer was precipitated in a large amount of methanol, and the precipitate was filtered off and dried at 60 ° C.
Collected. Mw / Mn of this polymer was 24 and Mw was 216,000. Production Example 2 80 parts of styrene and 13 parts of butyl acrylate as monomers
Parts, 2 parts of acrylic acid and 0.3 parts of divinylbenzene were used in the same manner as in Production Example 1. Mw / Mn is 19
And Mw was 138,000. Production Example 3 60 parts of styrene and methyl methacrylate as monomers
The same procedures as in Production Example 1 were carried out except that 10 parts, 20 parts of butyl acrylate, 10 parts of methacrylic acid and 0.7 part of divinylbenzene were used. Mw / Mn was 40 and Mw was 324,000. Next, the reaction between the polymer and the decomposable metal compound was performed as follows. Production Example 4 100 parts of the polymer synthesized in Production Example 1 and 0.5 parts of iron (III) acetylacetone (decomposition temperature: 340 ° C.) were kneaded at 150 ° C. for 30 minutes using a roll mill. The gel content of the crosslinked polymer was determined by extraction using toluene as a solvent. Gel content was 24%. Production Example 5 100 parts of the polymer synthesized in Production Example 2 was added to 100 parts of xylene, dissolved while increasing the temperature, and heated to 130 ° C. In this polymer solvent, acetylacetone cobalt (II
I) One part (decomposition temperature 210 ° C.) was added and reacted at 120 ° C. for 5 hours. After the reaction, xylene was removed to obtain a polymer. The gel content of the heated polymer was less than 1%. Production Example 6 The reaction was carried out in the same manner as in Production Example 4, except that 100 parts of the polymer synthesized in Production Example 3 was used as the polymer, and 2 parts of chromium (III) salt of salicylic acid was used as the metal compound.
Gel content was 32%. Example 1 70 parts of the resin of Production Example 1 30 parts of carbon black (Printex manufactured by Degussa) were kneaded with a two-roll mill at 120 ° 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, 50% FC-72 (Sumitomo 3M) and KF96
(Shin-Etsu Silicon Co., Ltd., viscosity 3cst) Mixed solvent 1 with 50%
And diluted to give 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 at 140 ° C. for 60 minutes. Thereafter, a developer was prepared in the same manner as in Example 1. Example 4 A developer was prepared in the same manner as in Example 1 except that the resin obtained in Production Example 4 was used instead of the resin of Production Example. 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 apparent 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 exhibiting offset development, 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.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidemi Uematsu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (56) References JP-A-63-301966 (JP, A) JP-A Sho 50-80136 (JP, A) JP-A-62-59967 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/13 G03G 9/125

Claims (2)

(57) [Claims] 1. A method for dispersing toner particles comprising a colorant and a resin in a high-resistance low-dielectric-constant carrier liquid comprising a mixture of a fluorine-based solvent, an aliphatic hydrocarbon solvent and / or a silicon-based solvent. In the liquid developer for electrostatography, the resin component has a weight average molecular weight / number average molecular weight ratio of 4
A liquid developer for an electrostatic image, comprising a larger vinyl polymer. 2. A method of dispersing toner particles comprising a colorant and a resin 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 silicon-based solvent. In the liquid developer for electrostatography, the resin component has a weight average molecular weight / number average molecular weight ratio of 4
A liquid developer for electrostatic images, comprising a polymer obtained by reacting a larger vinyl polymer with a decomposable metal compound.