Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2011-07-26
2011-07-26
Boykin, Terressa M (Department: 1765)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S198000
Reexamination Certificate
active
07985823
ABSTRACT:
The invention aims at providing a process for the production of polycarbonate resin which is suppressed in discoloration and reduced in the content of crystalline foreign substance, gel, and so on. The invention relates to a process for the production of polycarbonate resin from raw materials, namely, an aromatic dihydroxyl compound and a carbonic diester through continuous transesterification by the use of a production unit provided with plural reactors, which comprises producing continuously an aromatic polycarbonate resin having a viscosity-average molecular weight of 10,000 to 20,000 for a prescribed time before the termination of the continuous transesterification, discharging the polymerization fluid, cleaning the insides of the reactors with a mixture of the raw materials and then with an aromatic monohydroxy compound, feeding the raw materials and a catalyst to the reactors after the internal temperatures and degrees of vacuum of the reactors have reached respectively to levels falling within −5% to +5% of the levels preset for manufacturing operation, and then initiating manufacturing operation again.
REFERENCES:
patent: 5601768 (1997-02-01), Kurihara et al.
patent: 6323302 (2001-11-01), Sasaki et al.
patent: 2008/0234445 (2008-09-01), Hamano et al.
patent: 1194656 (1998-09-01), None
patent: 1266443 (2000-09-01), None
patent: 0 992 522 (2000-04-01), None
patent: 6 56984 (1994-03-01), None
patent: 2000 63507 (2000-02-01), None
patent: 2002 363276 (2002-12-01), None
patent: 2003 138001 (2003-05-01), None
patent: 2004 197004 (2004-07-01), None
patent: 2006-335867 (2006-12-01), None
patent: 99 55764 (1999-11-01), None
Office Action issued Dec. 7, 2010, in China Patent Application No. 200780043073.7 (with English-language Translation).
Singaporean Office Action issued Sep. 30, 2010, in Singaporean Patent Application No. 2009034273.
Office Action issued Oct. 1, 2010, in Russian Patent Application No. 2009127771 with English language translation.
Korean Office Action issued May 16, 2011, in Korean Patent Application No. 2008-7027537, filed Sep. 25, 2007 (with English-language Translation).
Iwaki Kouji
Takahashi Kazuyuki
Uchimura Ryuuji
Boykin Terressa M
Mitsubishi Chemical Corporation
Oblon, Spivak McClelland, Maier & Neustadt, L.L.P.
LandOfFree
Production method of polycarbonate resin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Production method of polycarbonate resin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Production method of polycarbonate resin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2702809