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:
Nov. 20, 1990
Filed:
Feb. 24, 1989
Japan Synthetic Rubber Co., Ltd., Tokyo, JP;
Abstract
Hollow polymer particles having at least two polymer layers, wherein (1) the particles have an average particle diameter in the range of 0.15 to 20 micrometers, (2) each of the particles has an average equivalent hollow diameter/equivalent particle diameter in the range of 0.2 to 0.8, (3) the proportion of a toluene-insoluble portion of the particles is 20 to 90% by weight, (4) the polymer particles have a melt flow rate at 180.degree. C. under 10 kgf/cm.sup.2 of 0.1 to 1 g/10 min., (5) the inside layer of the two polymer layers is composed of a crosslinked polymer and (6) the outside layer of the two polymer layers is composd of a non-crosslinked polymer. This invention also provides hollow crosslinked polymer particles wherein the proportion of a toluene-insoluble portion of the particles exceeds 85% by weight, the melt flow rate of the polymer particles at 180.degree. C. under 10 kgf/cm.sup.2 is less than 0.2 g/10 min., and the outside layer is composed of a crosslinked polymer. The hollow polymer particles are useful, for example, as a pigment, and for a paper coating composition and a general-purpose coating composition.