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. 16, 1982
Filed:
Jun. 18, 1980
Fumio Fujita, Takatsuki, JP;
Shuji Kitamura, Ibaraki, JP;
Toshifumi Tamura, Takatsuki, JP;
Tsuneyuki Nagase, Takatsuki, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
A method for producing a hydrophilic gel comprising polymerizing acrylic acid and/or methacrylic acid in the presence of polyvinyl alcohol to obtain a polymer (A) which is then subjected to neutralization followed by heat treatment or to heat treatment followed by neutralization, or polymerizing a neutralized product of acrylic acid and/or methacrylic acid in the presence of polyvinyl alcohol to obtain a polymer (B) which is then subjected to heat treatment, wherein said polymerization is carried out in an aqueous solution having a total concentration of acrylic acid and/or methacrylic acid or its neutralized product (the weight of the neutralized product is converted to the acid basis) and polyvinyl alcohol of 10 to 60% by weight, said heat treatment temperature is 50.degree. to 150.degree. C., and the weight ratio of polyvinylalcohol is acrylic acid and/or methacrylic acid or its salt (the weight of the neutralized product is converted to the acid basis) is 5 to 95: 95 to 5.