| 摘要 |
<p>Polyamide copolymers are derived from hexamethylene diamine and a mixture of (a) terephthalic and (b) beta-methyl or -ethyl adipic acid in a molar ratio of (a):(b) between 1:9 and 6:4, optionally with the addition of a viscosity stabilizer which may be an excess of one of the specified reactants. Minor amounts of other acids, e.g. isophthalic or adipic may also be used. Polymerization is preferably effected in the presence of water, a thermostabilizer (e.g. phosphoric acid, p-toluene sulphonic acid, tannin, or copper, manganese or alkali halides) and a photostabilizer (e.g. hydroquinone or organic or inorganic copper or manganese salts). The polymers are primarily suitable for melt spinning, with or without pigments such as titania, but may also be moulded. The preferred polymers have an intrinsic viscosity of 0.6 to 1.5.</p> |
