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:
Mar. 04, 1997
Filed:
Dec. 18, 1995
Chung M Kuo, Kingsport, TN (US);
Richard T Bogan, Kingsport, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
Abstract
The specification discloses a process for the manufacture of cellulose acetate. The process reacts, at a temperature suitable for acetylation, an acetic acid activated pretreated cellulose raw material containing 100 parts cellulose by dry weight, and 0.5 to 40 parts of a bisulfate catalyst by dry weight of the cellulose. The bisulfate catalyst is selected from lithium bisulfate, sodium bisulfate, and potassium bisulfate. To enhance mixing with the activated and pretreated cellulose, the catalyst may be mixed with 2 to 4 parts of acetic anhydride by dry weight of the cellulose, and 4 to 6 parts of acetic acid by dry weight of the cellulose. In a further embodiment, 0.05 to 10 parts of a strong Bronsted acid by weight of the dry cellulose may be added as a co-catalyst.