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:
Jul. 10, 1989
Applicant:
Inventors:
Gerald K Chip, Scarborough, CA;
Alfred Rudin, Waterloo, CA;
Assignee:
Tioxide Group PLC, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08J / ; C08F / ;
U.S. Cl.
CPC ...
523201 ; 524 54 ; 524 57 ; 524 64 ; 524134 ; 521139 ; 525301 ; 525902 ;
Abstract
Swollen core/sheath polymeric particles are disclosed having one or more voids in the core formed by reaction with a base such as sodium hydroxide. The sheath contains styrene or similar monomer polymerized in an amount greater than 25 mole percent and the polymer is free of acid groups. The core contains acid groups. Swelling is effected at an elevated temperature and in the absence of an organic solvent. The swollen particles on drying in a paint or other composition have air in the voids and act then as opacifying agents.