| 摘要 |
<p>New branched polycarbonate (A) has a branch nucleus structure derived from one of the following cpds.: (1) alpha,alpha',alpha''-tris (4-hydroxyphenyl)-1,3,5-tri isopropyl benzene, (2) 1-alpha-methyl-alpha- (4'-hydroxyphenyl) ethyl)-4-(alpha,alpha-bis (4''-hydroxyphenyl) ethyl) benzene, (3) phloroglucinol and (4) trimellitic acid. The viscosity average mol. wt. of (A) is 15000-40000. (A) contains 3.5wt.% or less of acetone-solubles. The starting materials for the process for producing (A) comprise (i) a polycarbonate oligomer based on an aromatic divalent phenol deriv., tri- or higher-valent cpds. and phosgene, (ii) an aromatic divalent phenol deriv., and (iii) a terminating agent. The process comprises (1) reacting a soln. contg. the starting materials in a turbulent flow state, (2) adding to the mixt., when its viscosity increases, an alkali soln. while changing the flow condition to a laminar flow state.</p> |
