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. 13, 1982
Filed:
Dec. 13, 1979
Applicant:
Inventors:
Roberto Biaggi, Bergamo, IT;
Massimo Quintini, Bergamo, IT;
Assignee:
Sigma Italiana Prodotti Chimici S.p.A., Bergamo, IT;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08F / ;
U.S. Cl.
CPC ...
526200 ; 526202 ; 526203 ; 5263442 ;
Abstract
A process for producing vinyl chloride polymer which comprises polymerizing vinyl chloride monomer in aqueous suspension, in the presence of a free radical catalyst, a primary suspending agent apt to control the granulometric distribution of the particles of PVC obtained, as well as a secondary suspending agent consisting of partially hydrolyzed polyvinyl acetate having a saponification number between 520 and 600 and a viscosity, measured in a 4% methanol solution at 20.degree. C., between 0.5 and 2 cps.