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:
Sep. 10, 2002
Filed:
Oct. 27, 2000
Shin-ichi Hieda, Kanagawa-ken, JP;
Tadashi Kawabata, Kanagawa-ken, JP;
Shojiro Kuwabara, Kanagawa-ken, JP;
Masahiro Kurokawa, Kanagawa-ken, JP;
Mitsubishi Gas Chemical, Chiyoda-ku, JP;
Abstract
A methyl methacrylate syrup is produced by the steps of (1) preparing a starting material comprising methyl methacrylate or a monomer mixture mainly comprising methyl methacrylate, and dividing the starting material into 20 to 70% by weight of an initial charge and 30 to 80% by weight of an after-charge; (2) heating the initial charge in a reactor; (3) adding a whole protion of a chain transfer agent at the time when the initial charge reaches a reaction temperature; (4) adding the after-charge over 0.1 to 10 hours together with a polymerization initiator having a half-life of 10 to 300 seconds at the reaction temperature; (5) continuing the heating after the addition of the after-charge and the polymerization initiator is complete; and (6) adding a hindered phenol polymerization inhibitor at the time the heating is finished. The methyl methacrylate syrup thus produced is excellent in storage stability.