JPS58209752A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic toner having good dispersibility by dispersing a vinyl monomer which can radical-polymerize or co-polymerize with graphite fluoride in a water-org. solvent mixed system or water-surfactant mixed system, effecting polymn. in the presence of a water soluble polymn. initiator, and coating the graphite fluoride with the polymer graft-bound with the graphite fluoride. CONSTITUTION:1g an aq. dispersion of polytetrafluoroethylene (PTFE) as a solid component, 1g (C2F)n microcapsuled with 10% methyl methacrylate, 0.1g a surfactant [fluorine surfactant (''Surfron'')], and 10ml methyl alcohol are mixed and dispersed with a colloid mill and the mixture is mixed with a toner consisting of 2 parts styrene oligomer and 0.1 part carbon black. The mixture is sprayed and dried with a spray dryer, whereby an improved toner is formed. Such toner is added by 30% to a magnetic carrier to prepare a developer. When the developer is used to copy 1,000 sheets continuously in a copying machine and the sticking of the toner on the photoconductive body is investigated, substantially no sticking is observed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for a dry or wet type developer used in electrophotography. 〇 Even when various dyes and/or pigments are used in the toner, the toner is uniform and sufficient. As an electrophotographic toner that exhibits high chargeability, a toner containing a dye and/or pigment and an inorganic polymer fluorocarbon in a resin has been proposed (Japanese Patent Application Laid-open No. 104255/1983). 5 Inorganic polymer Carbon fluoride, or graphite fluoride, is a white to gray circular powder obtained by reacting carbon or graphite with fluorine, and is known to be represented by (CF)n, where (CF)n is (CF)n. Due to its special lubricity, water and oil repellency, and poor chemical resistance, it is widely used as a solid lubricant, battery active material, etc.However, fluorinated graphite has low Due to its surface energy, it has strong water repellency, does not disperse in water, and has poor compatibility with resins, and when used in the above-mentioned electrophotographic toners, has low dispersibility in resins and is uniform and sufficient. There were disadvantages in that charging properties were still not obtained and toner fusion to the electrophotographic photosensitive plate occurred.

The present invention improves the drawbacks of the above-mentioned fluorocarbon-containing electrophotographic toner, and relates to an electrophotographic toner prepared by adding and dispersing fluorinated graphite after being coated with a vinyl polymer that has high dispersibility in resins, etc. In other words, the electrophotographic toner of the present invention is composed of a dye and/or pigment in a resin and fluorinated graphite coated with a vinyl polymer. Approximately 0.0% per 100 parts by weight of pigment. Generally, about 1 to 10 parts by weight of OO is blended.

The fluorinated graphite coated with a vinyl polymer used in the present invention is a vinyl monomer capable of radical polymerization or radical copolymerization with fluorinated graphite in a water-common solvent mixture system or a water-surfactant mixture system. Polymerization is performed in the presence of a water-soluble polymerization initiator, and the fluorinated graphite is coated with a polymer graft-bonded to the fluorinated graphite.

What is the fluorinated graphite used in the present invention? (CF)nz(02
F) In addition to those represented by n, it also includes mixtures thereof in different proportions.

Any organic solvent can be used as long as it is soluble in water, and examples include various alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone, ethers, and amines. , cationic, and nonionic surfactants may be used, or a mixture may be used.

On the other hand, the vinyl monomer for forming the polymer that coats the fluorinated graphite may be one that can be radically polymerized, - or radically copolymerized, such as acrylic acid, methacrylic acid, acrylate, methacrylic acid, etc. Acid acid, acrylate ester, meth! Monomers having a vinyl group such as lylic acid ester\acrylonitrile, N-methylolacrylamide, vinyl chloride, vinyl acetate, styrene, and divinylbenzene are used.

Examples of water-soluble polymerization initiators include sulfur dioxide, aqueous nitrous acid solution, bisulfite solution, potassium persulfate, azobiscyanovaleric acid, and V-50 (2,2-azobis-(2-amidinoprono')-dihydrochloride). Chloride, manufactured by Wako Tsumugi Pharmaceutical]
In order to suitably carry out the above production, 1 to 100 parts by weight of an organic solvent or 1 to 5 parts by weight of a surfactant, 1 to 100 parts by weight of fluorinated graphite and Sexual monomer 0.
Add 1 to 100 parts by weight and stir and disperse well. Add the polymerization initiator to the suspension obtained in this way and stir well. 1) The amount of polymerization initiator used is based on the amount of vinyl monomer. A range of 001 to 20 weight ratio is sufficient for the body.

By adjusting the pH during the polymerization reaction to 15 to 9, the grafting rate can be greatly increased. The polymerization reaction can be carried out at room temperature, but if it is desired to shorten the total polymerization time, it is sufficient to heat it to about 70 u, and a high polymerization rate can be obtained with a short polymerization time of about 1 to 5 hours.

After the polymerization reaction is completed, the streaky IJ-shaped fluorinated graphite is separated, thoroughly washed with water, and the residue is dried.

The fluorinated graphite polymer coating composition obtained by the method described above can be coated with any amount of resin, and the reaction conditions can be easily controlled. The resin content can take any value, but in order to improve dispersibility, it is necessary to have a content of at least 0.5% by weight, and there is no upper limit, but in order to exhibit the physical properties of fluorinated graphite, it is necessary to have a content of at least 0.5% by weight. Preferably it is up to the weight factor.

In this way, fluorinated graphite can be made into microgapcells using a very small amount of resin v (= microgapcells, and the resulting product can be freely molded. It is possible to form something close to a continuous adhesive film (layer) due to the coating, and even when dispersing into other materials, the surrounding area is covered with a compatible affinity polymer film, making it easy to disperse. It has extremely good performance, and therefore its performance can be effectively utilized.

The resin used in the present invention can be any of the many natural or synthetic resins conventionally used in electrophotographic toners, such as shellfish, giltonite, copal, rosin, polyester, styrene, ethylene, and globylene. , vinyl chloride 1. vinylidene chloride, acrylic acid,
(xylene) butadiene, coumaron, vinegar, vinyl acid, diallyl phthalate, butene, vinyl pyridine, vinyl formal, vinyl formal, ethyl cellulose, and polymers of these derivatives or copolymers thereof.

In addition, dyes and pigments can be used for all conventionally known dyes and pigments.
: However, as pigments, -bon black, furnace plano, li, iron black (magnetite), etc.
Examples of dyes include nigrosine dye, aniline blue, chrome yellow, ultramarine blue, methylene blue chloride, phthalocyanine blue, alcohol blue, and malachite green oxalate.

Example 1 Toner obtained by uniformly mixing polystyrene resin 50f and carbon black 1y1 polyvinyl butyral resin 22, and then uniformly blending fluorinated graphite (CF) n12 coated with 5 parts styrene (microencapsulated 2MC). was added to the magnetic carrier at 2%, continuous copying was carried out using a dry copying machine, and the amount of toner adhering to the surface of the photoconductive rod was measured after 18,000 copies were made. However, the amount of toner adhering was extremely small and practically impossible. There was no problem.

On the other hand, when we conducted an upward test on a product in which fluorinated graphite (JFI) which does not convert into MC was added and blended uniformly, a considerable amount of salmon toner was found to adhere to the surface of the photoconductive rod, resulting in ``stains on copies''. was also noticeable.

Aqueous dispersion of polytetrafluoroethylene (PTFHj) e,? Solid content: 12, methyl methacrylate: 10
% microencapsulated (C2F)n1t, surfactant [fluorosurfactant (Surflon, )) 0.1-
f. Mix and disperse 10-methyl alcohol in a colloid mill, add 2 parts of styrene oligomer and 0.1 part of carbon black.
15 parts of the toner were spray dried in a spray dryer to produce an improved toner.

Add 50 parts of this toner to a magnetic carrier to make a developer, and after making continuous +oooo copies with a copying machine,
When the toner adhesion on the photoconductor was examined, almost no adhesion was observed.

Example 5 100 parts of polystyrene resin, 10 parts of ultramarine blue dye, and 1 part of (02F) n microencapsulated with 5qb of polystyrene were heated and kneaded in a roll mill, cooled,
100 parts of carrier iron powder was mixed with 15 parts of toner that was pulverized to 5 to 10 microns using an air jet mill. The results of measuring the tripo charge of this toner are shown in the table below. For comparison, when MC is not used (02F) n k is used, the tube metal is shown at the same time when fluorinated graphite is not used. (Method) % Formula %) 3. Name with -4 supplement = Relationship with JG's death Patent applicant 1i< +i+i 52 Okiube, Ube City, Yamaguchi Prefecture
55 No. 4, Agent I Subject of amendment (1) Contents of amendment to page 9 a of the specification (1) Page 9 of the specification is corrected as shown in the attached sheet.

(No change in content) All 00 costumes are mixed. The results of measuring the triboelectric Tr of which toner are shown in the table below.
Do not convert to C' (CtF) n 't'' 7 When used with friends,
The values when fluorinated graphite is not used are also shown.

Agent Uchida: Makoto Agent Ryo Hagi Hara -

Claims (1)

[Claims] An electrophotographic toner prepared by dispersing dye/pigment and fluorinated graphite coated with a vinyl polymer in a resin.