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:
Aug. 20, 1991
Filed:
Dec. 26, 1989
Applicant:
Inventors:
Assignee:
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08J / ; C08J / ; C08J / ;
U.S. Cl.
CPC ...
521 65 ; 521 57 ; 521 59 ; 521 64 ;
Abstract
A process for preparing polymer emulsion particles having pores therein, an outside diameter D of 0.1 to 5.0[ , an inside diameter d of 0.05 to 4.0.mu. , and a ratio (d/D) of 0.1 to 0.9 in dry condition, comprising the steps of forming core-shell emulsion particles from specific monomers by two-emulsion polymerizations, and swelling the core of the particles with water by hydrolyzing the vinyl acetate part of polymer (A), thereby inducing the hydroxyl groups therein, e.g., using an acidic material or a basic material at 50.degree. to 100.degree. C. The particles when use as a pigment in coating compositions provide excellent converage rate, brightness, gloss and water resistance.