JP2895547B2 - Liquid developer for electrostatic image - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

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 solvent 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 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 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 is preferably 10 cst or less, and more preferably 3 cst or less. In the present invention, an alkali salt of a polyolefin or a polyolefin copolymer is used as a means for increasing the cohesive strength of the toner. The liquid developer, especially the toner, contains an alkali salt of a polyolefin or a polyolefin copolymer, and the polyolefin or a copolymer thereof contains at least a carboxyl group or a basic group. For example, as the carboxyl group, acrylic acid, methacrylic acid,
Maleic acid, maleic anhydride, itaconic acid, fumaric acid, and the like, and basic groups include vinylpyridine, vinylpyrrolidone, and the like. Examples of the alkali salt include amine salts such as dimethylamine, diethylamine, triethylamine, and ethanolamine, and pyridine, quinoline, morpholine, and ammonium salts. Thus, a polyolefin or a copolymer thereof is used as an alkali salt. In the case where the copolymer itself contains a basic group as described above, it is not necessary to dare to use an alkali salt. However, in this specification, a copolymer containing such a basic salt as a monomer is also treated as an alkali salt of a polyolefin copolymer. Some examples of the alkali salt of the polyolefin or polyolefin copolymer according to the present invention are as follows. In addition, the numerical value described in parentheses after the polymer or the copolymer here is the weight ratio (wt%) of those copolymer structures. (1) Triethylamine salt of ethylene-maleic acid copolymer (95/5) (2) Pyridine salt of ethylene-ethyl acrylate-acrylic acid copolymer (60/30/10) (3) Ethylene-glycidyl acrylate-acryl Dimethylamine salt of acid copolymer (50/40/10) (4) Monoethanolamine salt of propylene-methacrylic acid copolymer (95/5) (5) Propylene-vinylpyridine copolymer (90/10) (6) Ethylene-vinylpyridine-methacrylic acid copolymer (80/10/10) (7) Ethylene-vinylpyrrolidone-methacrylic acid copolymer (90/5/5) (8) Triethylamine salt of polyethylene oxide (9) ) Pyridine salt of polyarene oxide (10) Triethylamine salt of ethylene-divinylbenzene-maleic acid copolymer (80/2/18) (11) Ethylene-methacrylic acid copolymer (90/10) Pyridine salt (12) Propylene-glycidyl methacrylate-methacrylic acid (80/10/10) pyridine salt (13) Ethanolamine salt of ethylene-methacrylic acid copolymer (95/5) (14) Propylene-ethyl acrylate-maleic Morpholine salt of acid copolymer (60/30/10) (15) Ammonium salt of ethylene-ethyl acrylate-methacrylic acid copolymer (70/25/5) Examples of inorganic pigments used as colorants include: , Furnace black, acetylene black as carbon black,
Channel Black, PRINTEX G as a commercial product,
PRINTEX V, Special Black 15, Special Black 4, Special Black 4-B (made by Degussa), Mitsubishi # 44, # 30, MA-11, MA-100 (Mitsubishi Carbon), Raven 30, Raven 40, Conductex SC
(Manufactured by Columbia Carbon), Regal 400, 660, 800
Black Pearl L (manufactured by Cabot Corporation) and the like. Further, inorganic white pigments such as zinc oxide, titanium oxide and silicon oxide can also be exemplified. Organic pigments include phthalocyanine blue, phthalocyanine green, rhodamine lake, malachite green lake, methyl violet lake, peacock blue lake, nattole green B, permanent red 4
R, Hansa Yellow, Benzidine Yellow, Thioindigolet and the like. In the present invention, an organic pigment alone, an inorganic pigment alone may be used, or a mixture thereof may be used. As the resin to be covered with the pigment, the above-mentioned alkali salts of the above-mentioned polyolefin or a copolymer thereof are used. All of the binder resin is made of the above-mentioned alkali salt of polyolefin and / or
Alternatively, a polyolefin copolymer and an alkali salt can be used, but 10 to 90% by weight of the entire binder resin, preferably 40 to 90% by weight.
It is desirable that the alkali salt is used in such an amount that it accounts for 80% by weight. As resins other than the alkali salt, polyolefin, acrylic resin, rosin-modified resin,
Examples include styrene butadiene resin, epoxy resin, polyester resin, natural resin, paraffin wax, and other resins. For example, paraffin wax and polyolefin include the following. Manufacturer Brand Softening point Allied Chemical AC polyethylene 1702 85 ° C AC polyethylene 617,616A 102 AC polyethylene 9.9A 117 AC polyethylene 430 60 AC polyethylene 405 95 AC polyethylene 401 102 AC polyethylene 540 108 AC polyethylene 580 108 Kodak Epolen N-14 105 Epolen N- 15 96 Sanyo Chemical Sunwax 131-P108 Sunwax 151-P107 Sunwax 161-P111 Sunwax 165-P107 Sunwax 171-P105 Sunwax E-250P 102 Sunwax E-300P 98 Genuine chemical paraffin wax 40 to 90 Hoechst PED 521 104 PED 543 110 PED 153 98 Yasuhara Yushi Neowax L 105 Neowax E 100 The dispersing resin used in the present invention is 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, Alternatively, it represents 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,
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 used as the carrier liquid, a silicon material having an acroyl group, LS4080 manufactured by Shin-Etsu Silicon Co., Ltd. may be copolymerized to increase dispersibility, and similarly, AK manufactured by Toa Gosei Chemical -5, manufactured by Chisso
TM0701, FM0711, FM0721, and FM0725 may be used. As the colorant, ordinary inorganic or organic pigments may be used as described above, but it is particularly preferable to disperse the pigment particles into primary particles in particular, and to further improve gradation, resolution, image density, and the like. The flushing method is effective. In the flushing method, a pigment or a water-containing paste of a pigment is put into a kneader called a flasher together with a resin solution or a resin and mixed well (in this process, water present around the pigment is replaced by the resin solution or the resin). This is taken out from the kneader, the aqueous phase is discarded, and the pigment obtained by kneading and dispersing the pigment in the resin solution or resin at room temperature is dried to remove the solvent, and then the resulting mass is pulverized. This is referred to as "flushing pigment" in the present invention. In addition, an allowance for removing water and the solvent under reduced pressure while kneading with a kneader may be adopted. In the flushing process, not only the pigment but also the dye is kneaded with water in a muddy state, so that almost the same result as the pigment can be obtained. Therefore, in the present invention, the paint to be flushed can be used as a toner component. It is. The ratio of the dye to the resin at the time of flushing is suitably from 10 to 60 parts by weight of the dye to 100 parts by weight of the resin. It is particularly advantageous to carry out the flushing treatment in the presence of humic acid, humates (Na salt, NH ₄ salt, etc.) or humic acid derivatives. The amount of the humic acids to be added is suitably about 0.1 to 30% by weight of the aqueous solution of the dye and pigment. As the resin used for flushing, any resin which has been conventionally used as a binder resin for a wet toner can be applied. In particular, in the present invention, an alkali salt of a polyolefin and / or a polyolefin copolymer and an alkali are used. It is preferred to use salts. The following are some examples of manufacturing in the case where the flashing process is performed. Colorant Production Example-1 200 g of water in a gallon kneader, ammonium humate 20
250 g of carbon black (manufactured by Mitsubishi Kasei Corporation, Mitsubishi # 44) was put into the well-dissolved g, and mixed and dispersed well in a kneader. Next, 750 g of the ethylene-maleic acid copolymer triethylamine salt of the above (1) was added, and the mixture was heated and mixed at about 100 ° C. to separate water. After further kneading at about 120 ° C. for 4 hours, vacuum drying, cooling and pulverization were performed to obtain a flushing colorant. Colorant Production Example-2 200 g of water and 250 g of carbon black (Mogal A, manufactured by Columbia Carbon Co., Ltd.) were placed in a gallon kneader, and mixed and dispersed well in the kneader. Next, sun wax 151P 300
g and 300 g of the pyridine salt of the ethylene-ethyl acrylate-acrylic acid copolymer of (2) above, and the mixture was heated and kneaded at about 150 ° C. to separate water. Furthermore, after kneading at about 120 ° C. for 2 hours, vacuum drying, cooling,
Pulverized to obtain a flushing colorant. 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". Example 1 Flushing colorant (colorant production example-1) 50 parts lauryl methacrylate / methyl methacrylate /
Methacrylic acid / glycidyl methacrylate (80/10/5 /
5) 100% Isopar H solution of copolymer 100 parts Isopar H (trade name of EXXSON) 200 parts 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. And Take 200 g of this, 50% Florinert FC-72 (Sumitomo 3M) and 50% KF96 (Shin-Etsu Silicone, viscosity 3cst)
To prepare a developer. Example 2 60 parts of pyridine salt of ethylene-ethyl acrylate-acrylic acid copolymer of the above (2) 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. 200 g of this was diluted in a mixed solvent 1 of 50% Florinert FC-72 (manufactured by Sumitomo 3M) and 50% Isopar H to prepare a developer. Example 3 A liquid developer was prepared in exactly the same manner as in Example 1 except that the colorant was changed to that of Colorant Production Example-4. Example 4 Ammonium salt of ethylene-ethyl acrylate-methacrylic acid copolymer (72/25/5) of (15) 100 parts Carbon black (manufactured by Degussa, Printex) 50 parts Isopar H 300 parts A liquid developer was prepared in the same manner as in Example 1 except that the liquid developer was dispersed for 10 hours. 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 concentration of the solvent gas was measured.
m, whereas in the developer of the present invention, 80 to 150
It was halved to 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-1-142561 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/125 G03G 9/13

Claims (2)

(57) [Claims] 1. A toner solution comprising a colorant and a resin dispersed 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. A liquid developer for an electrostatic image, comprising a resin component containing an alkali salt of polyolefin or a polyolefin copolymer as the resin component. 2. The liquid developer for an electrostatic image according to claim 1, wherein the colorant is produced by a flushing method using the alkali salt of the polyolefin or the polyolefin copolymer.