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. 23, 2000
Filed:
Jul. 09, 1999
Applicant:
Inventors:
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08F / ;
U.S. Cl.
CPC ...
525464 ; 528 26 ; 528 13 ; 528 23 ;
Abstract
A process for the production of polysiloxane/polycarbonate block cocondensation products is disclosed. The process comprises reacting in the melt at temperatures of 250 to 320.degree. C. and pressures of 0.01 to 100 mbar (a) a hydroxyaryloxy-terminated dimethylsiloxane with (b) an oligocarbonate. The oligocarbonate is characterized in that its weight average molecular weight is 3000 to 24000 and the molar ratio of its OH end groups to aryl end groups is 10:90 to 70:30. The weight ratio of said (a) to said (b) in the inventive process is between 1:99 and 40:60. Also disclosed are the products prepared by the process.