| 摘要 |
PURPOSE:To obtain the title copolymer excellent in hue stability upon heating and low in double refraction, by copolymerizing 2,2-bis(4-hydroxy-3-tert- butylphenyl)propane with propane with a specified compound through carbonate bonds. CONSTITUTION:A mixture (A) of 99-1mol.% 2,2-bis(4-hydroxy-3-tert-butylphenyl) propane (a) with 1-99mol.% at least one compound (b) selected from among 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, etc., is reacted with diphenyl carbonate (B) in an amount slightly excess over the stoichiometric amount of component A at 160-180 deg.C and normal pressure for about 30min in the presence of catalyst. The product is precondensed at 180-220 deg.C while the pressure is being decreased to about 10Torr over a period of about 2-3h4 and then postcondensed at a temperature of 220-270 deg.C and a pressure of about 10Torr for 30min, then at a pressure of 5Torr for about 30min, and finally at pressure <=0.5Torr for 1.5-1.0hr to form carbonate bonds. |
