| 摘要 |
<p>1378480 Polyesters BAYER AG 25 May 1973 [26 May 1972] 25138/73 Heading C3R A polyester having an acid number greater than 35 is derived from a polyhydric alcohol and at least three dicarboxylic acids, the acids comprising (a) from 1À1 to 55 mole per cent of maleic acid and tetrahydrophthalic acid and (b) from 98À9 to 45 mole per cent of at least one other dicarboxylic acid, the molar ratio of maleic acid to tetrahydrophthalic acid being equal to or greater than 1. The examples describe polyesters prepared from maleic anhydride, tetrahydrophthalic anhydride and (a) 1,2-propanediol, trimethylolpropane, adipic acid and isophthalic acid, or (b) phthalic anhydride, 1,6-hexanediol, 1,2-propanediol and trimethylolpropane. The amine salt of the polyester may be mixed with titanium dioxide and a melamine resin to give a water-dilutable lacquer which may be coated on an iron sheet.</p> |
