Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Process of making developer composition
Reexamination Certificate
1998-06-01
2001-07-10
Dote, Janis L. (Department: 1753)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Process of making developer composition
C430S114000, C430S109500, C264S141000, C264S143000
Reexamination Certificate
active
06258503
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for producing a colored image-recording composition for electrophotography, electronic printing, electrostatic recording or the like or a colored composition for fluidized bed coating, electrostatic powder coating, powder coating or fine-powdery-resin-type coating, and also to a colored fine particulate composition obtained by the process.
2. Description of the Background
To obtain a colored image-recording composition, especially a colored image-recording composition capable of producing a picture having uniform tone and color density, it has been the conventional practice to first produce a natural resin (feedstock resin) through a polymerization process and, subsequent to cooling of the resin into flakes, to subject the resulting resin to processing such as coarse grinding, fine grinding, sacking, storage and shipping. Further, upon production of a toner for electrophotography or the like, materials required for the production—such as the thus-stored fine powder of the natural resin for the toner and a coloring matter and, if necessary, a charge control agent—are weighed based on a predetermined formula. Subsequent to their mixing in a mixer such as a tumbling mixer or Henschel mixer, the resultant mixture is fed to a resin kneader such as a twin-roll mill, triple-roll mill or kneader, where the mixture is heated to a temperature at least equal to a melting temperature of the resin, for example, to 130 to 180° C. to melt the resin so that the coloring matter and, if any, the charge control agent are kneaded and dispersed in the resin. This conventional process requires such irksome and time-consuming processing, and consumes enormous heat energy is enormous.
SUMMARY OF THE INVENTION
The present inventors have proceeded with an extensive investigation to develop a production process for the economical and rational mass production of a colored fine particulate composition of excellent quality while overcoming the above-described problems about the production of conventional colored fine particulate compositions, for example, colored image-recording compositions, an economical problem of distribution of the natural resin upon its production, sacking, storage and shipping, and problems such as the irksomeness of the production steps of the colored fine particulate composition and the substantial consumption of energy due to overlapping in the steps. As a result, it has been found that a colored fine particulate composition, which is excellent in the dispersion of a coloring matter and the like and can produce a picture having uniform tone and color density, can be economically furnished by simultaneously conducting the production of a resin and the production of the colored fine particulate resin composition. Based on this finding, the present inventors proceeded with a further investigation, leading to the completion of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one aspect oaf the present invention, there is thus provided a process for producing a colored fine particulate composition by dissolving or dispersing a coloring matter or a coloring matter and charge control agent in a condensation-polymerized resin component and forming the resultant resin composition into fine particles, wherein the coloring matter or the coloring matter and charge control agent are added to a raw material component for the production of the resin component, or to the resin component in a period from initiation to completion of polymerization of the resin component or while the resin component is in a molten state subsequent to the completion of the polymerization, whereby the coloring matter or the coloring matter and charge control agent are dissolved or dispersed in the resulting resin component; a colored composition obtained subsequent to the dissolution or the dispersion is cooled; and the colored composition so cooled is then formed into fine particles. In another aspect of the present invention, there is also provided a colored fine particulate composition obtained by the process.
To use the above-described colored fine particulate composition as a dry or wet image-recording, colored composition, the colored fine particulate composition is classified as needed, and known additives such as a fluidizing agent, a ferromagnetic carrier material and a liquid dispersion medium are mixed.
According to the present invention as described above, it is possible to provide an image-recording, colored composition useful for electrophotography, electronic printing or electrostatic recording and also a colored fine particulate composition useful as a fluidized bed coating formulation, electrostatic powder coating formulation, power coating formulation or fine-powdery-resin-type coating formulation.
Further, the rationalized production steps of excellent economy that the production of the resin and the production of the colored fine particulate composition, especially the image-recording, colored composition are conducted at the same time have made it possible to overcome the conventional drawbacks such as the irksomeness and the substantial consumption of heat energy in the production and distribution of the natural resin and the production steps of the image-recording, colored composition and further to achieve the economical and rational mass-production of a colored fine particulate composition which is excellent in quality, especially is superb in the dispersion of the coloring matter and can produce a picture having uniform tone and color density.
According to the process of the present invention as applied for the production of an image-recording, colored composition, a coloring matter, such as a pigment, and a charge control agent, which have been finely dispersed in advance, are added and mixed concurrently with the polymerization reaction of a resin component as a binder, whereby the image-recording, colored composition is obtained with excellent dispersion of the coloring matter in a form free of coarse particles of the coloring matter. Therefore, a picture formed with the colored composition is excellent in vividness and transparency. The image-recording, colored composition according to the present invention is hence suited for copying an image not only on a paper sheet but also on an overhead projector film.
On top of the quality, the process according to the present invention has also been found to bring about significant merits from the standpoints of production steps and economy. Taking the resin component as an example, all the conventional steps subsequent to the polymerization reaction, that is, cooling, coarse grinding, fine grinding, sacking, storage, shipping and the like are no longer needed. Upon production of the image-recording, colored composition as a developer, the premixing step of powders—such as the resin component, the coloring matter and the charge control agent—and its subsequent melting and kneading steps are no longer needed. The production process is substantially simplified, thereby saving heat energy and also making a substantial economical contribution to the reduction of the production cost.
The present invention will hereinafter be described in further detail on the basis of preferred embodiments.
In the process according to the present invention, it is necessary to dissolve or finely disperse the coloring matter and, if any, the charge control agent (hereinafter called “the coloring matter and the like”) in the resin upon production of the colored fine particulate composition. By conducting this dissolution or dispersion step during the condensation polymerization step of the resin, the production steps of the colored fine particulate composition are rationalized. A description will hereinafter be made about specific examples of a method for conducting this dissolution or dispersion step during the condensation polymerization step of the resin.
(1) The coloring matter and the like are dissolved or finely dispersed beforehand in the raw mater
Kanbara Yukio
Kanou Kazuo
Kinnou Masayuki
Nakajima Keiji
Nakamura Chikamasa
Dainichiseika Color & Chemicals Mfg. Co. Ltd.
Dote Janis L.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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