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:
Aug. 07, 1990
Filed:
Oct. 13, 1987
Shigeru Okuma, Hofu, JP;
Kanji Yamagishi, Hofu, JP;
Masami Hara, Hofu, JP;
Keizo Suzuki, Osaka, JP;
Toshihiro Yamamoto, Hofu, JP;
Hideo Yoshidome, Kishiwada, JP;
Kanebo, Ltd., Tokyo, JP;
Kanebo Rayon, Ltd., Osaka, JP;
Abstract
Fine crosslinked cellulose particles, wherein (1) said cellulose particles are composed substantially of a II-type cellulose crystalline phase and a non-crystalline cellulose phase, (2) said cellulose particles have a crystallinity, determined by X-ray diffractometry, of 5 to 35%, (3) said cellulose particles consist substantially of spherical to elongated spherical particles having an average particle diameter of not more than 300 .mu.m, and (4) said cellulose particles having an exclusion limit molecular weight by polyethylene glycol of not more than 4,000. The particles may have crosslinkage among the cellulose molecular chains in the non-crystalline phase. The fine crosslinked cellulose particles are prepared by (1) preparing fine particles of a coagulated viscose of cellulose xanthate, (2) subjecting the fine particles of coagulated viscose to crosslinking reaction and then neutralizing them with an acid, or first neutralizing said fine particles with an acid and then subjecting the neutralized particles to crosslinking reaction, and (3) separating the resulting fine crosslinked cellulose particles from the mother liquor, and heat-treating them after optionally subjecting them to desulfurization or to washing with an acid, water or methanol.