| 摘要 |
1,229,591. Resin-impregnated glass cloth laminates. TORAY INDUSTRIES Inc. 10 April, 1968 [11 April, 1967; 17 April, 1967], No. 17361/68. Heading B5N. [Also in Divisions B2 and C3] The production of heat resistant polymers by reacting in a solvent butane 1,2,3,4-tetracarboxylic acid or an ester thereof with a di-, tri- or tetra-primary amine (the third and fourth NH 2 groups being adjacent to the others) is effected by heating in two stages (i) to produce an intermediate composition containing the solvent and an oligomer of inherent viscosity 0À01 to 0À3 and (ii) (optionally after adding further solvent) with progressive evaporation of solvent until cyclization is substantially complete. Shaping may be effected between the two steps. Cyclizing catalysts may be present. Numerous esters of the tetra-acid, polyamines, cyclizing catalysts and solvents are mentioned. Fillers such as electroconductive powders, e.g. carbon black, or milled glass fibres, rockwool, asbestos fibres or boronitride fibres may be incorporated in the oligomer solution. Applications.-The polymers may be used to make self-supporting films, optionally rendered conductive by incorporating conductive particles; for coatings especially on metal, e.g. copper or aluminium, wires or sheets; to impregnate glass cloth which may be used as a varnish cloth or to form laminates with further such sheets or between metals, minerals, glass, porcelain or polymers; and to produce fibrereinforced thermoset articles. The examples describe the application of the polymers for films (Examples 1, 4, 5, 8, 13, 15 to 17, 21, 22, 27 and 28), coatings (Examples 2, 9 to 11, 14, 18 to 20, 24, 25 and 27), laminates (Examples 3, 6, 7, 12, 26 and 29) and a moulded plate (Example 23). |
