The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 1999
Filed:
Oct. 09, 1998
Ko Murakami, Hyogo, JP;
Toshinori Okano, Hyogo, JP;
Hiroki Taniguchi, Hyogo, JP;
Atsunobu Kiyose, Hyogo, JP;
Shu Shimamoto, Hyogo, JP;
Daicel Chemical Industries, LTD., Osaka, JP;
Fuji Photo Film Co., LTD., Minamiashigara, JP;
Abstract
Cellulose acetate having a high moldability and low solution viscosity in spite of having a high average degree of polymerization is obtained. The low molecular weight components of cellulose acetate (e.g., CTA having average degree of acetylation of 59.0 to 62.5%) are eluted with a washing solvent to produce a cellulose acetate having a molecular weight distribution Mw/Mn of 1 to 1.7. As the washing solvent, those swell or partially dissolve the cellulose acetate, for example, those which dissolve 0.1 to 30% by weight of cellulose acetate can be used. This solvent includes, for example, a solvent having a solubility parameter .delta. of 7 to 12.5 (ketones, ethers, organic acid, esters, etc.).