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:
Feb. 27, 1990
Filed:
Dec. 16, 1988
Phyllis L Brusky, Columbus, OH (US);
Richard A Markle, Columbus, OH (US);
Marion Laboratories, Inc., Kansas City, MO (US);
Abstract
Disclosed is a method for preparing poly(2-hydroxyethyl methacrylate) polymers (PHEMA) by a precipitation/suspension polymerization technique wherein a reaction mixture comprising hydroxyethyl methacrylate monomer (HEMA), solvent, and a free-radical initiator is subjected to heating for a time adequate for said PHEMA to be formed. The improvement in process of the present invention comprises restricting said HEMA to contain less than about 0.5 wt-% polyfunctional acrylate content, incorporating a suspending agent in said reaction mixture, agitating said reaction mixture during said heating, and restricting said solvent to one having a solubility parameter of between about 7.5 and 9, to produce PHEMA polymer particles ranging in size from about 30 to 1,000 microns and having a molecular weight ranging from about 500,000 to 2,000,000.