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, 1979
Filed:
Jul. 12, 1977
Applicant:
Inventor:
Hugo Illy, Reinach, CH;
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08J / ;
U.S. Cl.
CPC ...
521 95 ; 2603 / ; 521142 ; 521146 ; 521147 ; 521149 ; 521180 ; 521182 ; 521189 ;
Abstract
Bis-tetrazoles wherein the two tetrazole rings are bridged by a direct bond or a divalent organic residue in 5,5'-position or in 1,1'-position have been found to be suitable as blowing agents for thermoplastic resins. They decompose at temperatures of about 230 to 300.degree. C. and therefore can be used for the expansion of resins which are processed at such temperatures, for instance polypropylene, polycarbonates, polyphenyleneoxides or polyamides. Preferred are bis-tetrazoles bridges by aliphatic or araliphatic residues. The expansion can be carried out in an extruder or an injection moulding device.