US 7,514,522 B2
Method for producing polycarbonate copolymer
Yasuhiro Ishikawa, Chiba (Japan); Koichi Suga, Chiba (Japan); Yoshio Ikeda, Chiba (Japan); and Masatoshi Saitou, Chiba (Japan)
Assigned to Idemitsu Kosan Co., Ltd., Tokyo (Japan)
Appl. No. 10/587,974
PCT Filed Feb. 17, 2005, PCT No. PCT/JP2005/002421
§ 371(c)(1), (2), (4) Date Aug. 03, 2006,
PCT Pub. No. WO2005/080468, PCT Pub. Date Sep. 01, 2005.
Claims priority of application No. 2004-042493 (JP), filed on Feb. 19, 2004; and application No. 2004-042494 (JP), filed on Feb. 19, 2004.
Prior Publication US 2008/0221295 A1, Sep. 11, 2008
Int. Cl. C08G 64/00 (2006.01); C08G 63/02 (2006.01)
U.S. Cl. 528—196  [525/67; 525/436; 525/464; 528/176; 528/198] 10 Claims
 
1. A method for producing a polycarbonate copolymer comprising structural repeating units represented by formulas (I) and (II):

OG Complex Work Unit Drawing
wherein each of R1 and R2 independently represents a C1 to C6 alkyl group; X represents a single bond, a C1 to C8 alkylene group, a C2 to C8 alkylidene group, a C5 to C15 cycloalkylene group, a C5 to C15 cycloalkylidene group, —S—, —SO—, —SO2—, —O—, —CO—, or a group represented by formula (III-1) or (III-2):

OG Complex Work Unit Drawing
each of R3 and R4 independently represents a C1 to C3 alkyl group; Y represents a C2 to C15 linear-chain or branched alkylene group; a to d are independently integers of 0 to 4; and n is an integer of 2 to 450, by reacting (A) a dihydric phenol, (B) a phenol-modified diol and (C) a carbonate precursor, wherein the phenol-modified diol (B) is represented by formula (IIa) and comprises 500 ppm by mass or less of a hydroxybenzoic acid:

OG Complex Work Unit Drawing
where R3, R4, Y, c, d and n are as defined above.