| 摘要 |
1,254,265. Polyester compositions. TORAY INDUSTRIES Inc. 16 Feb., 1970 [18 Feb., 1969; 21 Feb., 1969], No. 7253/70. Heading C3R. A polyester composition comprises a mixture of (a) a linear polyester, at least 80% by weight of the units of which have the general formula in which G is an aliphatic hydrocarbon group having from 2 to 15 carbon atoms or an alicyclic hydrocarbon group having from 4 to 15 carbon atoms and (b) a polyether-polyester block copolymer in which the polyether blocks have the general formula -(RO-) n in which R stands for an alkylene group and n is an integer from 100 to 1000, the total weight of polyether units being from 10 to 97-5% by weight of the block copolymer and from 0-1 to 10% by weight of the total mixture. The relative viscosity of the block copolymer is preferably at least 2-5 and the melt viscosity of the block copolymer at 290‹ C. is preferably from 0-1 to 10 times that of the linear polyester. The composition may contain a surface active agent. A compound having at least three ester forming groups may be added during the preparation of the block copolymer to increase its relative viscosity. In the examples the linear polyesters used are polyethylene terephthalate or an ethylene terephthalate/ethylene isophthalate copolymer and the block copolymer used was that of polyethylene terephthalate and polyethylene glycol or ethylene oxide/propylene oxide block copolymer, which may also contain residue of 1,2,4,tri(2- hydroxyethyl)trimellitic ester, l,2,4,5-tetra-(hydroxyethyl) pyromellitic ester or pyromellitic anhydride as a viscosity increasing agent. In Examples 23 and 24, dodecyl-benzene sodium sulphate was added as a surface active agent.
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