JP2826852B2 - Liquid developer for electrostatic image - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial fields]

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

[Prior art]

As a liquid developer for heat roll fixing roll,
-301966 to 301969, JP-A-5-50062 to 50067, JP-A-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 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. 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, a crosslinked rosin-modified polyester is used as a means for increasing the cohesive strength of the toner. (I) rosin glycidyl ester, (II) as a resin
At least one crosslinking agent selected from the group consisting of dicarboxylic acids or dicarboxylic anhydrides, (III) polyfunctional epoxy compounds, tribasic or higher polybasic acids or their anhydrides and trihydric or higher polyhydric alcohols , And (IV) a dihydric alcohol having a softening point of 50 to 190.
The present invention relates to a toner composition for electrophotography, comprising a rosin-based polymer compound having a glass transition point of 10 to 170 ° C. and a molecular weight of 2,000 to 40,000. The rosin glycidyl ester (I) used in the present invention can be adjusted by heating and reacting rosin and shrimp halohydrin in the presence of an alkaline substance such as an organic amine. Examples of the rosin to be used include natural rosins such as gum rosin, wood rosin, tall oil rosin, hydrogenated rosins obtained by modifying these rosins, and disproportionated rosins. Naturally, abietic acid, dehydroabietic acid, dihydroabietic acid, dihydroabietic acid, hymalic acid, isohimic acid and the like, which are organic components of rosin, can also be used. The organic amines are preferably tertiary amines or onium salts thereof. Specific examples of the tertiary amines include triethylamine, dimethylbenzylamine, methyldibenzylamine, tribenzylamine, dimethylaniline, and dimethyldicyclohexylamine. , Methyldicyclohexylamine, tripropylamine, dolibutylamine, N-phenylmorpholine, N-merylpiperidine, pyridine and the like. Specific examples of onium salts of tertiary amines include tetramethylammonium chloride, tetramethylammonium bromide, benzyltriethylammonium chloride, allyltriethylammonium bromide, tetrabutylammonium chloride, methyltrioctylammonium chloride, and trimethylamine hydrochloride. Salts, triethylamine hydrochloride, pyridine hydrochloride and the like can be mentioned. Examples of the dicarboxylic acid or dicarboxylic anhydride (II) (II) used in the present invention include orthophthalic acid, isophthalic acid, terephthalic acid, endomethylenetetrahydrophthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid. Acid, hexahydrophthalic acid, methylhexahydrophthalic acid, maleic acid, fumaric acid, succinic acid, adipic acid, azelaic acid, sebacic acid, alkenyl succinic acid having 8 to 10 hydrocarbons, alkyl having 6 to 18 carbon atoms And succinic acid and acid anhydrides thereof. Examples of the crosslinking agent (III) used in the present invention include the following compounds. Bifunctional epoxy compounds include bisphenol A
And epoxy resin which is a blend of epihalohydrin and rosin epoxide or rosin triepoxide which is a reaction product of acrylated rosin or fumarated rosin and epihalohydrin. The rosin used for the polyepoxide of the rosin is the same as that used for the rosin glycidyl ester. Examples of the tribasic or higher polybasic salt or anhydride thereof include trimellitic acid, pyromellitic acid and acid anhydrides corresponding thereto. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. The dihydric alcohol is used for adjusting the glass transition point of the rosin-based polymer obtained by reacting the other components (I), (II) and (III), and improving the low-temperature fixability. The dihydric alcohol (IV) used in the present invention is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol triethylene glycol, propylene glycol, and 1,2-butanediol 1,3-.
Butanediol, 11,4-butanediol, bisphenol, hydrogenated bisphenol A, ethoxylated bisphenol A, propoxylated bisphenol A, bishydroxyethyl terephthalate, and the like. The amount of the dihydric alcohol used is appropriately determined in consideration of the glass transition point of the obtained rosin-based polymer compound.
The rosin glycidyl ester is used by replacing 1 to 70 mol% of the rosin glycidyl ester with a dihydric alcohol. As a method for producing the rosin-based polymer compound used in the present invention, for example, rosin diglycidyl ester, the dicarboxylic acid, the cross-linking agent and the dihydric alcohol are simultaneously charged, and in the presence of the organic amine as a reaction catalyst. Or a method of heat reaction in the absence, rosin glycidyl estyl, dicarboxylic acids and dihydric alcohols are heated and reacted in the presence or absence of organic amines, and charged with a crosslinking agent during or after the reaction,
Further, a method of proceeding the reaction by heating may be employed. In this case, the molar ratio of rosin glycidyl ester to dicarboxylic acids is preferably set to 1: 1.
It can be in the range of 1.0 to 1.5. On the other hand, the amount of the cross-linking agent used has a significant effect on the properties of the obtained binder resin for toner, especially on the molecular weight and the molecular weight distribution, and therefore it must be determined carefully as appropriate. The amount of the polyfunctional epoxy compound used in the cross-linking agent may be determined in consideration of the number of functional groups of the compound, that is, the epoxy equivalent.When the total number of moles of the rosin glycidyl ester and the dicarboxylic acid is usually 1 mol, For example, 0.005 to 0.07 for fumarated rosin triglycidyl ester
Mol, preferably 0.05 to 0.04 mol. In the case of a commercially available bisphenol type epoxy resin, 0.005 to 0.14 mol,
Preferably, it is 0.005 to 0.07 mol. Similarly, polyhydric carboxylic acids or polyhydric alcohols are also usually considered in consideration of the number of their functional groups, for example, 3 moles per mole of rosin glycidyl ester and dicarboxylic acids in total.
If the value is 0.005 to 0.3 mol, preferably 0.005 to 0.15
Use within the mole range. Organic amines are not necessarily required in the reaction, but may be used to shorten the reaction time depending on the type of dicarboxylic acid used. In this case, rosin glycidyl ester is usually used.
It is good to be in the range of 0.01 to 5% by weight, preferably 0.05 to 1% 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. MR-100 (Mitsubishi Kasei), Raven 1035, Raven 1252, Newspect II (Colombia Carbon), Legal 400, 660, Black Pearl 900, 110
0, 1300, inorganic pigments such as Mogar L (manufactured by Cabot Corporation) 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, Risor Fast Yellow 2G, Permanent Red 4R, 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
And other organic pigments. 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, ocully wax, natural wax such as beeswax, wood wax, nuka wax, ester gum, cured 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, 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. Silicon material with acroyl group to improve dispersibility in silicon solvent, LS4080 manufactured by Shin-Etsu Silicon
Or 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. 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】

Production Example 1 (Production of Disproportionated Rosin Glycidyl Ester) Disproportionated rosin (acid value 162, softening point 79) having a linearity of 0.7% (13% unsaponifiable) was added to 500 ml of lorbene equipped with a stirrer and a reflux condenser. ℃) 100g, shrimp chlorohydrin 200
g and 0.1 g of benzyltrimethylammonium chloride were added and reacted at 60 ° C. for 4 hours. Then, 16 g of granular sodium hydroxide was added in portions at the same temperature, the temperature was raised to 100 ° C., and the reaction was further performed for 2 hours. After filtering the precipitated salt, unreacted epichlorohydrin was distilled off from the filtrate with a rotary evaporator, and further the volatile matter was completely removed under the conditions of 2 mmHg and 120 ° C. to give the title pale yellow substance (yield 97.2%) I got Disproportionated rosin glycidyl ester 450 parts Phthalic anhydride 250 parts Triethylene glycol 90 parts The reaction was examined at 240 ° C. for 4 hours under N ₂ atmosphere. Further, 5 parts of trimetic anhydride was added and the reaction was continued until a predetermined molecular weight was obtained, to obtain a resin. After dissolving 450 parts of disproportionated rosin glycidyl ester at 120 ° C. for 2 hours at 180 ° C., add 135 parts of dodecenyl succinic anhydride, react at 240 ° C. for 3 hours, and further add 20 parts of fumarated rosin triglycidyl ester to react. And a resin was obtained. Example 1 70 parts of the resin of Production Example 1 30 parts of carbon black (Printex manufactured by Degussa) 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 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 200 parts of this, KF96 (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 parts (polyethylene manufactured by Sanyo Chemical Co., Ltd.) 8 parts MA60 (Mitsubishi Kasei carbon black) 35 parts were kneaded with a flasher and then ground. 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. Take 200g of this, KF96 (Shin-Etsu Silicon, viscosity 3cs
t) Diluted in 1 to obtain a developer. Example 3 60 parts of resin of Production Example 3 AC400A (Allied Chemical Co.) 10 parts Regal 400 (Cabot Co.) 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 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, 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.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hidemi Uematsu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-50-80136 (JP, A) JP-A Sho 63-4249 (JP, A) JP-A-63-301969 (JP, A) Japanese Patent Publication No. 41-6396 (JP, B1) Japanese Utility Model Publication No. 40-26990 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/13 G03G 9/125

Claims (1)

(57) [Claims] 1. A liquid developer for electrophotography comprising toner particles comprising a colorant and a resin dispersed in a carrier liquid having a high resistance and a low dielectric constant containing a silicon-based solvent as a main component. A group consisting of (I) rosin glycidyl ester, (II) dicarboxylic acid or dicarboxylic anhydride, (III) a polyfunctional epoxy compound, a tribasic or higher polybasic acid or an acid anhydride thereof, and a trihydric or higher polyhydric alcohol. A softening point obtained by reacting at least one type of crosslinking agent selected from
50-190 ° C, glass transition point 10-170 ° C, molecular weight 2000-40
A liquid developer for an electrostatic image, comprising a rosin-based polymer compound of 000.