GB662007A - Improvements in aminoplastic resin compositions containing latent curing catalysts - Google Patents

Abstract

A urea-formaldehyde or melamine-formaldehyde resin contains as a latent curing catalyst tetrachlorophthalic acid or anhydride in an amount of 0.05 to 0.5 per cent based on the weight of the resin or on the weight of the resin plus filler if a filler is present. Inhibitors, e.g. hexamethylene tetramine, other curing catalysts, e.g. paratoluene sulphonamide, and lubricants, e.g. calcium or zinc stearate, may also be present. Specified fillers are alpha-cellulose, wood flour, asbestos fibres, glass fibres, threads and woven cloth. In examples: (1) a master batch catalyst is prepared by ball-milling alpha-cellulose filled urea-formaldehyde resin, para-toluene sulphonamide, tetrachlorophthalic anhydride and zinc stearate and this is ball-milled in examples (A) to (H) with various proportions of alpha-cellulose filled urea-formaldehyde resin, hexamethylene tetramine and zinc stearate and the mixtures moulded; (3) in examples (A)-(J) moulding compositions are prepared by mixing alpha-cellulose filled urea-formaldehyde resin, tetrachlorophthalic anhydride, hexamethylene tetramine and zinc stearate; (4) pigmented moulding compositions are prepared using the ingredients of example (3) and non-ferrous pink, white, blue and ivory pigments. The resin compositions of the invention also find application as adhesives and laminating and coating compositions. The Specification as open to inspection under Sect. 91 states that "unsaturated polyester alkyd resins" may be employed with the aminoplasts in providing surface finishing compositions. This subject-matter does not appear in the Specification as accepted.