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:
Jun. 07, 1994
Filed:
Nov. 23, 1992
Kao Corporation, Tokyo, JP;
Abstract
Fine particles of a crosslinked vinyl polymer having a very high compressive modulus of elasticity, i.e., above 550 kg/mm.sup.2 but not higher than 800 kg/mm.sup.2, and being able to be effectively employed as a material capable of maintaining a minute gap constant, and a process for producing the same which comprises polymerizing 100 parts by weight of a vinyl monomer mixture consisting essentially of 20 to 90 parts by weight of m-divinylbenzene, 10 to 60 parts by weight of a vinyl monomer having a nitrile group and 0 to 50 by weight of a vinyl monomer other than m-divinylbenzene and vinyl monomers having a nitrile group in the presence of 3 to 10 parts by weight of a radical polymerization initiator belonging to the organic peroxides, in an aqueous medium.