GB957915A - Treatment of fabrics made from glass, asbestos or metallic fibres - Google Patents

Abstract

According to the Provisional Specification sheet materials for use as vehicle panels, machinery guards, radar scanner reflectors, and casings and linings for refrigerators &c., are made by coating woven or unwoven fabrics of glass, asbestos or metal fibres with a molten monomeric polyamide-forming cyclic lactam containing at least 6 carbon atoms in the ring and containing an alkaline polymerization catalyst and heating and pressing to convert the lactam to a polyamide solid or ordinary temperatures. The lactam which may be applied by dipping or spraying, is preferably caprolactam but may be a higher lactam such as enantholactam or capryl-lactam. The sheets may be flat or shaped. Catalysts usable include alkali or alkaline earth metals or their hydrides, oxides, alkoxides, hydroxides, carbonates, or alkyl or aryl componuds (e.g. lithium butyl or phenyl), or Girgnard reagents such as ethyl magnesium chloride or methyl or phenyl magnesium bromide. Polymerization promoting agents may also be included in the lactam composition, e.g. N-alkyl-imides, organic isocyanates, cyanamides, carbodiimides, N,N1-disubstituted ureas (1,3-dimethyl or diphenyl urea), or dialkyl carbonates (diethyl or di-n-butyl carbonate). Reference has been directed by the Comptroller to Specification 900,152.ALSO:According to the Provisional Specification sheet materials for use as vehicle panels, machinery guards, radar scanner reflectors, and casings and linings for refrigerators &c., are made by impregnating fabrics of asbestos fibres with a molten monomeric polyamide-forming cyclic lactam containing at least 6 carbon atoms in the ring and containing an alkaline polymerization catalyst, and heating to convert the lactam to a polyamide solid or ordinary temperatures. The lactam which may be applied by dipping or spraying, is preferably caprolactam but may be a higher lactam such as enantholactam or capryllactam. The sheets may be flat or shaped. Catalysts usable include alkali or alkaline earth metals or their hydrides, oxides, alkoxides, hydroxides, carbonates, or alkyl or aryl compounds (e.g. lithium butyl or phenyl), or Grignard reagents such as ethyl magnesium chloride or methyl or phenyl magnesium bromide. Polymerization promoting agents may also be included in the lactam composition, e.g. N-alkyl-imides organic isocyanates, cyanamides, carbodiimides, N, N1 disubstituted ureas (1, 3 dimethyl or diphenyl urea), or dialkyl carbonates (diethyl or di-n-butyl carbonate). Reference has been directed by the Comptroller to Specification 900,152.