JPH03200265A - Liquid developer for electrostatic charge image - Google Patents

Abstract

PURPOSE:To decrease the gaseous solvent of a hydrocarbon system generated from a copying machine by incorporating a self-crosslinking type polymer and crosslinked high-molecular polymer as a resin component into the above liquid developer. CONSTITUTION:The self-crosslinking type polymer and the crosslinked high- molecular polymer are used for the toner resin component of the liquid developer formed by dispersing toner particles consisting of a coloring agent and resin into a carrier liquid essentially consisting of a silicone solvent and having a high resistance and low dielectric constant. The self-crosslinking type polymer is preferably a copolymer contg. a diene compd. having conjugated double bonds or the modified matter thereof and is more particularly preferably a copolymer of a compd. having a vinyl group, such as, for example, a styrene/ butadiene compd. and a diene compd. having conjugated double bonds. The already crosslinked high-molecular polymer is preferably the high-molecular polymer, etc., of arom. vinyl compds., such as, for example, styrene. Thus, the amt. of the gaseous hydrocarbon to be generated from the copying machine is decreased and the heat roll fixing is executed without generating offsetting even if a fixing roll is not coated with oil.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field) The present invention relates to a liquid developer for hot roll fixing used in electrophotography, electrostatic recording, electrostatic printing, and the like.

(Prior art 1) As a liquid developer for heat roll fixing roll, JP-A-63
-301966 to 301969, 64-500
No. 62-50067, No. 64-52167, No. 64-
142560-142561, etc. Since these are carrier liquids mainly composed of aliphatic hydrocarbons, the aliphatic hydrocarbon gas is discharged outside the copying machine, and it is necessary to supply silicone oil to be applied to the fixing roll. There were problems such as the copying machine becoming more complex and the number of consumables increasing.

[Objective 1 of the present invention] An object of the present invention is to reduce hydrocarbon solvent gas generated from a copying machine.

To make it possible to remove an oil application device to a fixing roll in a hot roll fixing device using a liquid developer, and to save the trouble of oil supply.

By mixing in a certain proportion of nonflammable liquid, the risk of ignition is reduced.

(Structure 1 of the Invention In recent years, hot roll fixing has been proposed as a fixing method for liquid developers that has high thermal efficiency and is capable of high-speed fixing.If a hydrocarbon-based solvent is used as the carrier liquid and this fixing method is adopted,
Compared to conventional atmospheric fixing, the amount of solvent gas emitted per unit number of sheets is slightly reduced, but a large amount of solvent gas is generated when copying a large number of sheets at high speed. Also,
It was necessary to apply silicone oil to improve the releasability between the toner layer and the fixing roll. The present invention uses a silicone solvent as a carrier liquid to improve the above-mentioned drawbacks, increase the cohesive force of the toner, and prevent so-called "hot offset".

The silicone solvent used in the present invention includes KF
96 (Shin-Etsu Silicon), 5H200, 5H344 (Toshi Silicon), TSF451 (Toshiba Silicon), etc. In addition, decamethyltetrasiloxane, octamethyltrisiloxane, etc. may be used. In addition, as aliphatic hydrocarbon solutions, cyclohexane, n-hexane, n-
Hebutane, n-octane, n-nonane, isooctane,
Petroleum hydrocarbons such as isododecane, ligroin, and mixtures thereof (commercially available products include Isopar E, G, H, L, and V manufactured by Exxon Chemical Co., Ltd., and Shellzol 71 and Solupesso 150 manufactured by Shell Oil Company). These can be mixed and used as appropriate. To reduce transfer agent, the carrier liquid should be less than 10 cst, preferably 3 cst.
The following is good.

In the present invention, as a means for increasing the cohesive force of toner,
Examples include using a self-crosslinking polymer and a crosslinked high molecular weight polymer in the toner resin component.

The self-crosslinking polymer used in the present invention is preferably a copolymer or modified product containing a diene compound having a conjugated double bond. For example, compounds with vinyl groups and conjugated double bonds such as styrene-butadiene copolymer, styrene-glolobrene copolymer, styrene-isoprene copolymer, styrene-piperylene copolymer, acrylonitrile-butadiene copolymer, etc. A copolymer with a diene compound having the following is particularly preferred.

Yet another feature of the present invention is that the self-crosslinking type polymer described above is used in combination with a high molecular weight polymer that is already crosslinked without self-crosslinking.

Already crosslinked polymers that can be used in the present invention include aromatic vinyl compounds such as styrene, esters of unsaturated aliphatic monocarboxylic acids such as acrylic esters, or esters of unsaturated aliphatic monocarboxylic acids such as maleic esters. Homopolymer copolymers of esters of unsaturated aliphatic polycarboxylic acids, high molecular polymers made by crosslinking terpolymers with compounds having polyfunctionality of dihydric or higher valence, or dihydric alcohols and dibasic acids and trihydric acids. Non-linear polyester resins made of the above alcohols or carboxylic acids are preferred.

Generally, polymers having a weight average molecular weight/number average molecular weight of greater than 40 and a weight average molecular weight of 100,000 or more are preferred. In addition, self-crosslinking type coalescence/crosslinking type coalescence is 0.5
/9.5 to 715 is preferable.

As a coloring material that can be used in the present invention, Printex V
, Printex U1 Printex G, Special Black 15, Special Black 4, Special Black 4-B (manufactured by Degussa), Mitsubishi = 44, #30%M
R-11, MA-1'OO (manufactured by Mitsubishi Chemical Corporation), Raben 1o35, Raben 1252, New Spect ■ (
(manufactured by Columbia Carbon), Regal 400.66
Inorganic pigments such as 0, Black Burl 900.110011300, Mogul Shikori (manufactured by 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 Yellow S, Naphthol Red, Linole Fast Yellow 2G, Permanent Red 4R, Brilliant First Scarlet, Hansa Yellow, Benzidine Yellow, Lysol Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Permanent Red F5R, Pigment Scarlet 3B Indigo,
Examples include organic pigments such as Thioindigo Oil Pink and Bordeaux 108.

The pigment can be treated by mixing and crushing the above pigment with the resin using a two-roll machine, a kneader flasher, or the like. Further, the following resins may be used together with the above resins.

Eastman Chemical
al) manufactured by (N-1o, N-11, N-12, N-14
, N-34, N-45, C-1o, C-13°C-15
, C-16, E-10, E-11, E-12, E-14
, E-15) Manufactured by Kochu Petrochemical Co., Ltd. (l IOP, 220P, 220MP, 820M
P, 410MP, 210MP, 310MP.

405MP, 200P, 4202E, 4053E
) Manufactured by Kochu Kasei Co., Ltd. (131P, +5IP, +6IP, +7IP, E
300. E250P) manufactured by Sasol (formerly, H2, At, A2.A3.A4) BASF (BAS
Manufactured by F) (OA WAX, A WAX) Manufactured by Petrolite (Valeco (B)
ARECO) 500. Same 2000. E-730,E-
2018, E-2020, E-1040, Betronaba (
Petronaba) C, C-36゜C-400,
C-7500) Manufactured by Hoechst (PE580. PE130. PED121. PE
D136. PED153. PED521. PED
522. PED534) Made by Union Carbide (DYNI, DYNF, DYNH, DYNJ, D
YNK) Monsando (OR1lZON) 805,705.50)
DuPont (ALATHON) 3. to, +2.1
4.16.20.22.23) Allied Chemical Company (AC polyethylene 6.6A, 615) Kou Polychemical Company (Evaflex 150, 210, 220, 250, 2
60,310,360°410.420,450,46
Synthetic polyesters such as 0,550,560), polypropylene and their modified products, natural waxes such as carnauba wax, montan wax, candelilla wax, sugar cane wax, oculie wax, rice bran, wood wax, bran wax, ester gum, Natural resins such as hardened rosin, natural resin-modified maleic acid resins, natural resin-modified phenol resins, natural resin-modified polyester resins, natural resin-modified pentaerythtol resins, and natural resin-modified hardened resins such as epoxy resins can be used in combination.

The dispersing resin preferably used in combination with the present invention includes a vinyl monomer A having the general formula % (R, represents H or CH, and n represents an integer from 6 to 20) and the general formula %. Vinyl monomers represented by the formula %) and vinylpyridine, vinylpyrrolidone, ethylene glycol dimethacrylate,
Examples include copolymers and graft copolymers of each type of monomer B selected from styrene, divinylbenzene, and vinyltoluene, or several types of monomers.

In addition, in order to improve dispersibility in silicone solvents, silicone materials with acroyl groups, LS, 4 manufactured by Shin-Etsu Silicon Co., Ltd.
080, etc. may be copolymerized, and similarly, AK-5 manufactured by Toagosei Kagaku Co., Ltd., (7) 7MO701, F manufactured by Chisso Co., Ltd.
MO711, FMO721, and FMO725 may also be used.

These coloring materials, resins, and carrier liquids are put into a dispersing machine such as a ball mill, kitty mill, disk mill, and bottle mill, and then dispersed and mixed to prepare a concentrated toner, which is then dispersed in the carrier liquid of the present invention for development. liquid can be obtained.

(Example 1 All "parts" in the following examples represent "parts by weight."

Combination example! Styrene-butadiene copolymer (self-crosslinking type) 50 parts by weight Blending example 2 Blending example 3 Example 1 Resin of Blending example 1 70 parts Carbon black (Pr1ntex V manufactured by Degussa),
30 parts were mixed with two rolls at 90° C. for 30 minutes and then ground.

50 parts of the pulverized product 200 parts of Isopar H (product name of EXXSON) were placed in a ball mill and dispersed for 24 hours, and then 300 parts of Isopar H was further added and dispersed for 1 hour to obtain a concentrated toner. 200 g of this was taken and diluted in KF96 (manufactured by Ikoshi Silicon Co., Ltd., viscosity ACSTlQ) to prepare a developer.

Example 2 Resin of Formulation Example 2 57 parts 250
8 parts of P (polyethylene made by Kochu Kasei Co., Ltd.) and 35 parts of A60 (carbon black made by Mitsubishi Kasei Co., Ltd.) were mixed with a flasher and then pulverized.

A developer was obtained in the same manner as in Example 1, except that 60 parts of the pulverized material and 100 parts of Isopar 8 were used.

Example 3 Naimeen 3202 0.2 parts AC400A (manufactured by Allied Chemical Co., Ltd.) Regal 40
0 (manufactured by Cabot Corporation) 10 parts and 30 parts were cross-milled at 140° C. for 60 minutes using a flasher.

A developer was prepared in the same manner as in Example 1.

Comparative Example Comparative developers 1 to 3 were obtained in the same manner as in Examples 1 to 3, except that Isopar H was used as the diluent.

An oil-less fixing test was carried out using a test machine, CT5085 manufactured by Ricoh, whose fixing unit was improved to a hot roll fixer. The results are shown in the table below.

It can be seen that a temperature within a possible range was obtained, and hot roller fixing was possible.

Continuous copying was carried out using a test copying machine in a closed room, and the solvent gas concentration was measured. When using the comparative developer, the concentration of solvent gas was 300 to 360 ppm, whereas with the developer of the present invention, it was 80 to 360 ppm. The concentration had been halved to 150 ppm.

(Effect 1) By using the developer of the present invention, it is possible to perform hot roll fixing without applying oil to the fixing roll and without causing an offset phenomenon, allowing a compact copying machine to achieve high speed and constant fixation with low energy. The amount of hydrocarbon gas generated by copying machines has also been reduced.

Claims (1)

[Claims] In an electrostatographic liquid developer in which toner particles made of a colorant and a resin are dispersed in a high-resistance, low-permittivity carrier liquid containing a silicone solvent as a main component, a self-crosslinking polymer is used as the resin component. A liquid developer for electrostatic images, characterized by containing a combined and crosslinked high molecular weight polymer.