Fuji Photo Film Company, Limited

Hiroshi Onishi

Tadahisa Sato

Katsuyoshi Yamakawa

Tadahiro Tsujimoto

Naoyasu Deguchi

Nobuaki Miyasaka

Masayuki Kuroishi

Kazutoshi Inada

A method of making cellulose polymer solution comprises dissolving a cellulose polymer raw material in a chlorine-free organic solvent system under a high temperature and a high pressure condition belonging to the nearcritical or the supercritical region of the system. By removing the solvent from the thus obtained cellulose polymer solution, cellulose polymer powders are also produced.

Method of producing cellulose polymers

A producing method of a cellulose polymer powder is provided, which comprises dissolving a cellulose polymer by exposure to an organic solvent containing, as the main component, an ester-based solvent having from 2 to 8 carbon atoms, a ketone-based solvent having from 4 to 10 carbon atoms, or an alcohol-based solvent having from 3 to 6 carbon atoms, and carbon dioxide, and then removing the carbon dioxide and the organic solvent from the solution. A producing method of an organic solvent solution of a cellulose polymer is also provided.

Producing method of cellulose polymer

A method for producing a photographic emulsion is disclosed. The method includes the process of adding a dispersion of a substantially water-insoluble photographic additive to a photographic emulsion. The dispersion being prepared merely by mechanically grinding and dispersing the photographic additive in a form of fine grain having a size of 1.mu. or less in an aqueous system adjusted to a pH value of 6 to 8 and controlled to a temperature of 60.degree. to 80.degree. C. The additive is included in the photographic emulsion without the need of an organic solvent. The emulsion of the invention can be easily and quickly coated to form a uniform layer.

Method for producing photographic emulsion

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Kanagawa, Japan

Hiroshi Onishi