GB472228A - Process for the manufacture and use of liquid self-hardening compositions derived from synthetic resins - Google Patents

Abstract

Solutions of hardenable synthetic resins, e.g. phenol-, urea-, or thiourea-formaldehyde condensation products, are ripened to syrupy semi-liquids by means of acid hardening accelerators, alone or mixed with known catalytic hardening agents, and are then dispersed in organic liquid solvents of the unripened resin whereby further ripening is prevented until use, e.g. as paints or binders for plastic masses. The product may be neutralized, e.g. by ammonia, hydrazine, or hydroxylamine; it may be mixed with solutions of hardenable or unhardenable resins, linseed oil varnish, linseed oil artificial resin solutions, e.g. phthalic acid-glycerine condensation products with linseed oil varnishes, or urea-, thiourea-, or phenol-formaldehyde-condensation products condensed with linseed oil, or with wax-like compositions which dissolve or are dispersable in the solvents of the resin; it makes self-hardening other hardenable resins in solution. The ripening may be effected at 5--15 per cent concentration and further ripening broken off by neutralization, or at 40--50 per cent concentration followed by dilution to 5--15 per cent resin content and breaking off of the ripening. Especially suitable catalysts are mixtures of acids with organic oxychlorides, alkyl sulphates, halogenated ethers or esters, acetyl chlorides or trichlorhydrocarbons such as benzotrichloride. Acids specified are boric, boric anhydride, phosphoric, hypophosphoric, phthalic, oxalic, lactic, nitric, and sulphuric. Solvents specified are alcohol, ketones, e.g. acetone, and ethyl acetate. The products p may be used as glazes, alone or mixed with starch; 0,1--2,0 per cent of organic hardening agents may be added at the time of use. The products also form binding agents for mineral powder, cellulose dust or fibres, starches, and fat-free carcin; the plastic masses produced may be pressed cold or warm or extruded. The Specification as open to inspection under Sect. 91 describes the preparation of ripened self-hardening liquid organic glazes, mixed or not with glaze-improving substances, by action or dissolved hardenable resins in the b -condition of about 0,1--3,0 per cent of inorganic or organic mono- or poly-valent acids or acid salts soluble in alcohol, acetone, or artificial-resin solvent hydrocarbons, or mixtures thereof. This subject-matter does not appear in the Specification as accepted.