GB758236A - Improvements relating to modified aminoplastic resinous compositions - Google Patents

Abstract

A modified aminoplast composition, particularly suitable for impregnating and laminating fibrous sheet materials, and as moulding material, comprises the uncured reaction product of an aldehyde and a monomeric compound containing at least two amidogen groups each having at least one hydrogen atom attached to the amidogen nitrogen, and an alpha-alkyl-d-glucoside, the alkyl group having 1 to 4 carbon atoms. Specific examples are a -methyl-, a -ethyl-, and a -butyl-d-glucoside. The preferred amidogen compounds are urea and melamine; others specified are methylmelamine, acetoguanamines, methyl-, phenyl-, allyl- and guanyl-urea, dimethylol urea and polymethylol melamines and their alkyl ethers, thiourea, phenyl- and guanyl-thiourea, dicyandiamide, guanidine, biguanide, diaminodiazines and guanazole. The preferred aldehyde is formaldehyde; others include para-formaldehyde, hexamethylene tetramine, acetaldehyde, propionaldehyde, butyraldehyde, furfural and benzaldehyde. The glucoside may constitute about 1 to 35 per cent by weight of the composition which is then water-dilutable. Fillers which may be incorporated in the moulding compositions include alpha-cellulose, wood flour, walnut shell flour, calcine or natural asbestos, silicon carbide, carbon black, graphite, diatomaceous earth, slate dust, and ground cuttings, e.g. of silk, rayon, nylon, glass cloth and ground cork. Curing agents may sometimes be used, e.g., phthalic acid and anhydride, p-toluene sulphonic acid and benzoyl peroxide, as well as mould lubricants such as zinc-, calcium- and glyceryl monostearate. For impregnation, the solutions may be aqueous, aqueous-alcoholic or aqueous-acetone. Suitable alcohols are methanol, ethanol, isopropanol and tert-butanol.