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:
May. 12, 1992
Filed:
Dec. 05, 1988
Director-General of the Agency of Industrial Science and Technology, Tokyo, JP;
Kashima Oil Co., Ltd., Tokyo, JP;
Abstract
The invention provides an aqueous thickener composition useful in the pros of enhanced oil recovery in petroleum technology. The thickener composition is prepared by the reaction of a xanthan gum or a similar high molecular weight polysaccharide with a low molecular weight aliphatic aldehyde such as formaldehyde in an aqueous medium in the presence of an inorganic salt such as sodium chloride in a concentration of 0.5 to 10% by weight so that an intramolecular crosslinked fine structure of superhelix is formed in the polysaccharide molecules and the aqueous solution of thus chemically modified polysaccharide is imparted with remarkably improved thermal stability as compared to the aqueous solutions of a similar polysaccharide which has been treated under the same conditions but in the absence of any inorganic salt in the reaction medium.