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:
May. 18, 2021
Filed:
Jul. 06, 2016
Mitsubishi Chemical Corporation, Chiyoda-ku, JP;
Mitsubishi Chemical Corporation, Chiyoda-ku, JP;
Abstract
The present invention provides a copolymer containing 80 mol % or more of a methyl (metl)acrylate unit (A), wherein the Vicat softening temperature thereof is 115° C. or higher, the saturated water absorption rate thereof at 60° C. is 4 % by weight or less, and the yellow index thereof is 1 or less. The process for producing the copolymer includes suspension polymerizing a monomer mixture containing 80 mol % or more of methyl (meth)acrylate (a) and 0.7 mol % to 7 mol % of (meth)acrylic acid (b), followed by melting and kneading the resulting precursor with an extruder to obtain a copolymer containing 80 mol % or more of a methyl (meth)acrylate unit (A), 0.45 mol % to 7 mol % of a (meth)acrylic acid unit (B), and 0.001 mol % to 0.25 mol % of a glutaric anhydride unit (C) wherein a conversion rate to the glutaric anhydride unit (C) is 0.1 % to 5 %.