Abstract: Copolyamides are described comprising: (1) 0.22-0.28 mole fraction units derived from terephthalic acid; (2) 0.2-0.28 mole fraction units derived from paraphenylene diamine; (3) 0.22-0.28 mole fraction units derived from isophthalic acid; and (4) 0.22-0.28 mole fraction units derived from a 3,3'- or 4,4'-diamine of diphenyl methane, diphenylpropane-2,2, diphenyl cyclohexane-1,1, diphenyl ether, diphenyl sulfide, diphenyl sulphone, or benzophenone.

Abstract: Polyurethanes having high hyperpolarizability densities and other favorable properties can be easily prepared from nonlinear optical active diols (NLO-diols) of a certain general formula, which have a delocalized .pi. electron system to which both an electron donor group and an electron acceptor group are coupled directly (D.pi.A system). The polyurethanes may be used in optical waveguides.

Abstract: A combination of 10-80% by volume of reinforcing fibres and 20-90% by volume of thermoplastic fibres or films suitable to be formed into a composite structure, the thermoplastic fibres or films essentially consisting of an amorphous copolyamide built up of units derived from at least two different dicarboxylic acids and at least two different diamines, of which the divalent aromatic radicals are linked together by amid bonds selected from the groups P1, P2, Q1 and Q2,P1: 1,4-phenylene, 1,5-naphthylene, 2,6-naphthylene and 4,4'-diphenylene;P2: radicals of the formula: ##STR1## where X=--C(Y) (Y')--, --O--, --S--, --SO.sub.2 -- or --CO--, and Y,Y' , are the same or different and represent hydrogen or C.sub.1-4 alkyl, or together cyclohexyl;Q1: 1,3-phenylene, 1,6-naphthylene, 2,7-naphthylene and 3,4'-diphenylene;Q2: radicals of the formula: ##STR2## where X=--C(Y)(Y')--, --O--, --S--, --SO.sub.2 -- or --CO-- and Y,Y' are the same or different and represent hydrogen or C.sub.

Abstract: An amorphous, injection-moldable copolyamide comprising linear chains of each of the units having the formulae:(I) --CO--Ar--CO--,(II) --NH--Ar--CO--, and(III) --NH--Ar--CO--,wherein Ar represents one or more optionally substituted arylene radicals selected from the group consisting of(1) para oriented arylene,(2) meta oriented arylene,(3) arylene-X-arylene, wherein X is --C(Y)(H)--, --O--, --S--, --SO.sub.2 -- or --CO--, with Y is H or C.sub.1-43 -alkyl, and(4) arylene-CZZ'-arylene, wherein Z,Z' are alkyl or cycloalkyl,provided that at least one of the units of the formulae (I), (II) or (III) are arylene radicals from more than one of the groups (1), (2), (3) and (4). Said units are preferably present in a molar ratio of 17-41.5% of (I), 17-41.5% of (II) and 17-66% of (III).

Abstract: Flexible layered product for use in waterproof garments or tents of a textile material covered with a waterproof material having a water vapor transmission rate of at least 1000 g/m.sup.2 day, the textile material being covered with a film of a copolyether ester consisting of a plurality of recurrent intralinear long-chain ester units and short-chain ester units which are randomly joined head-to-tail through ester bonds.

Abstract: A filament-forming polyester or copolyester and fibers thereof composed of at least 80% of ethylene terephthalate units containing a tertiary amine as an additive to improve the receptivity for acid dyes. The invention provides novel additives comprising 1,8-diamino-naphthalenes in which the two amino groups have four alkyl substituents with 1-4 carbon atoms and the nucleus may have H, alkyl or aralkyl substituents. The preferred additive is N,N,N',N'-tetramethyl-1,8-diamino-naphthalene. A preferred copolyester contains 1-10% ethylene azelate units. The novel additives improve the exhaustion of the dye bath and the wash fastness of the dyed filaments.