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:
Apr. 24, 1990
Filed:
Feb. 21, 1989
Karl Zabrocki, Buettgen, DE;
Christian Lindner, Cologne, DE;
Otto Koch, Cologne, DE;
Hans-Eberhard Braese, Cologne, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
An .alpha.-methylstyrene/acrylonitrile copolymer obtainable by emulsion polymerization which, in combination with other polymers, particularly PVC, enables alloys of outstanding thermal stability and color stability to be produced and, in addition, has a high heat distortion temperature and shows good fogging behavior and which is obtained by radically initiated inflow copolymerization of a mixture of 30 to 32 parts by weight acrylonitrile and 68 to 70 parts by weight .alpha.-methylstyrene in the presence of an emulsifier containing carboxyl groups. The polymerization is conducted in such a way that a seed latex of the same copolymer or of an analogous copolymer is introduced before addition of the monomers is commenced, the reaction temperature is kept between 75.degree. and 82.degree. C. and the molar ratio of emulsifier to initiator is between 4 and 6.