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. 24, 2014
Filed:
Mar. 23, 2012
Shinji Ohtomo, Tsukuba, JP;
Yusaku Kohinata, Tsukuba, JP;
Hidehiro Kotaka, Tsukuba, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Abstract
Disclosed is a method for producing a liquid crystal polyester, which includes the steps of: (1) polycondensing a mixture of 70.5 to 71.5 mol % of a compound represented by the defined formula (I) (for example, 4-acetoxybenzoic acid) with 28.5 to 29.5 mol % of a compound represented by the defined formula (II) (for example, 6-acetoxy-2-naphthoic acid) to form a prepolymer, wherein the prepolymer has a flow initiation temperature of 200° C. or higher, and the mixture is polycondensed until reaching the temperature which is at least 30° C. lower than the polycondensation temperature; (2) removing the prepolymer in a molten state, followed by solidification and further grinding to produce prepolymer particles; and (3) subjecting the prepolymer particles to a heat treatment at 200 to 310° C. under circulation of an inert gas while remaining in a solid phase state.