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:
Feb. 26, 2013
Filed:
Mar. 26, 2012
Shinji Ohtomo, Tsukuba, JP;
Tadashi Fukunaka, Niihama, JP;
Yi Zhang, Niihama, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Abstract
A method is provided for producing a liquid crystal polyester including: (1) polycondensing a mixture of a compound of formula (I) with a compound of formula (II) in a polymerization tank at 260 to 350° C. to form a prepolymer, wherein a ratio of by-products to be distilled off to the theoretical amount of by-products formed when the compound of formula (I) is polycondensed with the compound of formula (II) in a stoichiometric relation is 95% or more; (2) continuously discharging the prepolymer from the polymerization tank in a molten state, solidifying the prepolymer while transferring, and continuously grinding the solidified prepolymer by a grinder provided downstream in a transfer direction to produce prepolymer particles; and (3) heat-treating the prepolymer particles in their solid state under an inert gas atmosphere, thereby subjecting them to solid phase polymerization.