| 摘要 |
<p>1427057 Polyester resins GENERAL ELECTRIC CO 4 Oct 1973 [29 Nov 1972] 46288/73 Heading C3R A high molecular weight linear or substantially linear polyester resin is prepared by subjecting a bis ester of a glycol and terephthalic acid to self-condensation in the presence of a minor amount of a fatty acid of the formula C n H 2n+1 COOH where n = 8-30. The preferred amount of fatty acid used is from 0À20 to 2À5% wt. based on the bis ester. Suitable fatty acids include caprylic, capric, lauric, palmitic and stearic acid. Suitable glycols are ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-dimethylol cyclohexane, 2,2-bis[4-(#- hydroxyethyl)phenyl]propane or a mixture thereof. The bis ester may comprise up to 15 mol. per cent of groups derived from other polyols, such as glycerol, and/or up to 15 mol. per cent of groups derived from other dicarboxylic acids, such as, isophthalic acid, succinic acid and napththalene dicarboxylic acid. The intrinsic viscosity of the product ranges from 0À6-2À0 dl./g. measured for example on a solution in a 60 : 40 mixture of phenol and tetrachloroethane at 30‹ C. The self-condensation may be carried out in 3 stages by (i) heating the bis ester under reduced pressure at a temperature of 250-300‹ C. preferably until the partially condensed polyester produced has an intrinsic viscosity of 0À3-1À0 dl./g., (ii) adding the fatty acid to the partially condensed polyester, (iii) continuing heating under reduced pressure. In the examples polyesters are produced by the 3-stage process using (a) a bis ester prepared by heating dimethylterephthalate and 1,4-butanediol in the presence of tetra-2-ethylhexyl o-titanate and (b) stearic acid as the fatty acid. Uses.-Moulding powders either alone or mixed with other polymers and fillers, e.g. glass filaments, wood flour, cloth fibres and clays and other conventional additives.</p> |
