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:
Jul. 05, 1994
Filed:
Oct. 04, 1993
Dennis P Lorah, Lansdale, PA (US);
Thomas G Madle, Flourtown, PA (US);
Rohm and Haas Company, Philadelphia, PA (US);
Abstract
An emulsion polymerization process for making a low molecular weight alkali-soluble copolymer of a water insoluble monoethylenically unsaturated aromatic monomer and methacrylic acid, includes heating an aqueous reaction mixture, said reaction mixture having a pH of less than or equal to about 4.5 and including from about 25 parts by weight to about 75 parts by weight of the water insoluble monoethylenically unsaturated aromatic monomer; from about 25 parts by weight to about 75 parts by weight methacrylic acid; a polymerization initiator; a reducing agent; a catalyst effective for promoting decomposition of the polymerization initiator in the presence of the reducing agent; and an amount of a chain transfer agent effective to limit copolymer weight average molecular weight to a range of about 2,000 to about 40,000; to a temperature greater than or equal to about 75.degree. C.; and maintaining the reaction mixture at a temperature greater than or equal to about 75.degree. C. for a period of time effective to allow formation of the copolymer.