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:
Jun. 21, 1983
Filed:
Nov. 25, 1981
Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
A cellulose sulfate salt having a heparinic action is provided, which satisfies requirements of 0.8.ltoreq.<<F>>.ltoreq.2.6, <<f.sub.2 >>.gtoreq.<<f.sub.3 >> and <<f.sub.2 >>.gtoreq.<<f.sub.6 >> wherein <<f.sub.2 >>, <<f.sub.3 >> and <<f.sub.6 >> stand for probability of substitution of atoms H in the OH groups bonded to the C.sub.2, C.sub.3 and C.sub.6 positions of the glucopyranose ring unit by sulfuric acid radicals, respectively, and <<F>> stands for the total substitution degree which is the sum of <<f.sub.2 >>, <<f.sub.3 >> and <<f.sub.6 >>. The cellulose sulfate salt is prepared by reacting a cellulose having a crystal form I with an SO.sub.3 /amine or SO.sub.3 /amide complex in an amount of 2 to 4 mole equivalents per glucose unit of the cellulose at -10.degree. C. to 40.degree. C. to form a gelatinous product; adding water to the gelatinous product in an amount 0.1 to 5 times the amount of the starting cellulose used for the reaction; treating the mixture at a high temperature to relatively reduce the values of <<f.sub.6 >> and <<f.sub.3 >> among the values of <<f.sub.2 >>, <<F.sub.3 >> and <<f.sub.6 >>; neutralizing, precipitating and drying the so obtained crude cellulose sulfate; dissolving the crude cellulose sulfate in water again; treating the solution with an adsorbent; and subjecting the treated cellulose sulfate to precipitation, drying, re-dissolution, dialysis, precipitation and then drying.