| 摘要 |
1515585 Polysiloxane - polyester - polycarbonate block copolymers BAXTER TRAVENOL LABORATORIES Inc 19 Feb 1976 [10 March 1975] 6490/76 Heading C3T A linear thermoplastic alternating block copolymer comprising polydiorganosiloxane blocks, polyester blocks which are condensation products of a difunctional organo-diacid or a derivative thereof with an aromatic diol, and polycarbonate blocks which are condensation products of an organocarbonate precursor and an aromatic diol may be prepared by reacting under esterification conditions a difunctional polydiorganosiloxane, preferably an alpha,#-dichloropolydimethylsiloxane, an aromatic diol, a difunctional organo-diacid or derivative thereof and an organocarbonate precursor. Preferably the aromatic diol and polydiorganosiloxane are reacted together in a first step and the resulting product is reacted with the organodiacid or derivative thereof in a second step, and the resulting product is reacted with the organocarbonate precursor. Suitable organocarbonate precursors are carbonyl dihalides, e.g. phosgene, and bishaloformates of dihydric phenols or glycols. Suitable aromatic diols are 4,4<1> - isopropylidene diphenol, resorcinol, 2- methylresorcinol and hydroquinone. Suitable diacid derivatives are terephthaloyl chloride, isophthaloyl chloride, succinoyl chloride and adipoyl chloride. The block copolymer may be represented by the average formula wherein R is a divalent aromatic group and R<1> is a divalent organic group, R<11> is O, S, a divalent organic group attached to the adjacent Si atom by a C-Si or a C-O-Si bond, or a -NR<111> group, where R<111> is hydrogen or R<0> or R<0> attached to the nitrogen atom by a divalent carbonyl or thiocarbonyl group; R‹ is a monovalent organic group, e is greater than 0 and less than 1, x, y and z are positive numbers such that the molecular weight of each polyester, polycarbonate and polydiorganosiloxane segment is 100 to 100,000, the polyester and polycarbonate segments constituting 10 to 90% wt. of the copolymer. In an embodiment the diol is 4,4<1>-isopropylidene diphenol and the polyorganosiloxane segments are linked by Si to 1,3-propylene groups to aliphatic polyether linkages, particularly polyethylene ether, the polydiorganosiloxane comprising at least 50% by wt. of the combined polydiorganosiloxanepolyether. In Examples 1, 2 and 4 copolymers are prepared by reacting bisphenol A or a mixture thereof with resorcinol first with an alpha,#-dichloropolydimethylsiloxane and then with terephthaloyl chloride in the presence of an organic solvent and pyridine or trimethylamine as catalyst, followed by phosgenation. In Example 5 a copolymer is similarly prepared from bisphenol A, an alpha,# - dichloro - polydimethylsiloxane, terephthaloyl chloride and 1,4-butane diol, followed by phosgenation. Uses.-Medical devices. |
