Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Post imaging process – finishing – or perfecting composition...
Patent
1988-07-07
1990-03-20
Michl, Paul R.
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Post imaging process, finishing, or perfecting composition...
430137, 430138, 428407, 42840224, 264 41, G03G 908, B32B 516, B01J 1302
Patent
active
049101137
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to colored microfine globular particles, a method for the production thereof, and uses thereof. More particularly, it relates to colored microfine globular particles which have carbon black uniformly dispersed therein and are usable as a toner for the development of images of electro static charge, as a filler for thermoplastic resin compositions and coating compositions, as a coating agent for thermosensitive transfer ink ribbons, as a coloring agent for thermosensitive transfer ink ribbons, as a coloring agent for thermosensitive transfer ink, thermosetting resin compositions, and backcoats in magnetic recording media, and as a charge control agent, a method for the production of the colored microfine globular particles, and uses of the colored microfine globular particles.
2. Background Art
The electrophotography is a process of producing an image by forming an electric latent image on a photosensitive element formed with a photoconductive material such as selenium, zinc oxide, or cadmium sulfide, developing the latent image with a developing powder, transferring the image of the developing powder as onto a sheet of paper, and fixing the transferred image on the paper.
Heretofore, the toner used for the development of images of electro static charge has been generally produced by melting and mixing for thorough dispersion a coloring agent and other additives (such as a charge control agent, an offset preventing agent, and a lubricant) in a thermoplastic resin, then finely crushing the resultant solid mixture, classifying the produced particles, and selecting those of desired particle diameters as colored microfine particles.
The method which produces the toner by the aforementioned crushing, however, possesses various drawbacks of its own. Firstly, it involves many steps of operation such as the step of producing a resin, the step of mixing the resin with a coloring agent and other additives, the step of crushing the resultant solid mixture, and the step of classifying the particles resulting from the crushing and obtaining particles of desired diameters as colored microfine particles and, necessitates use of various devices adapted to perform these steps. The toner produced by this method is very expensive as an inevitable consequence. Particularly for the purpose of obtaining a toner the particles of which have diameters falling in the range optimum for the production of an image clear and sparingly liable to fog, the step of classifying the particles constitutes itself an essential requirement. It is, however, difficult to obtain perfect removal of extremely fine particles and coarse particles by-produced during the step of crushing. Moreover, the by-produced rejectable particles raise a problem from the standpoint of yield. Secondly, it is extremely difficult to obtain uniform dispersion of the coloring agent and other additives in the resin during the step of mixing. Thirdly, since the particles of the toner produced by this method have no fixed shape and consequently possess no uniform triboelectric property, no uniform charging property is exhibited between the adjacent particles and, as the result, the resolution of the image obtained with the toner is inferior. Further, owing to the lack of uniform shape, the particles of the toner exhibit poor flowability and the extremely fine fragments produced when the particles are crushed during the course of triboelectrification induce the phenomenon of fogging of the developed image. Thus, the method under discussion is problematic in numerous ways.
For the purpose of eliminating the various drawbacks suffered by the toner produced by the crushing method, various methods have been proposed for the production of the toner by the emulsion polymerization or suspension polymerization technique (Japanese Patent Publication SHO 36(1961)-10,231, Japanese Patent Publication SHO 43(1968)-10,799, U.S. Pat. No. 3,959,153, and U.S. Pat. No. 3,634,251). These methods are meant to provide speedy s
REFERENCES:
patent: 3544507 (1970-12-01), Lloyd
patent: 3883440 (1975-05-01), Tamai et al.
patent: 3959153 (1976-01-01), Sadamatsu et al.
patent: 4506002 (1985-03-01), Takaki et al.
patent: 4797340 (1989-01-01), Tanaka et al.
Fujikawa Iwao
Ikeda Hayato
Kushino Mitsuo
Minami Kenji
Mori Yoshikuni
Lindeman Jeffery A.
Michl Paul R.
Nippon Shokubai Kagaku Kogyo Kabushiki Kaisha
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