GB578229A - New resinous condensation products - Google Patents

Abstract

Resinous condensation products are produced by a process which comprises heating together in the presence of acid condensing agents an etherified melamine-formaldehyde condensation product and an etherified phenolformaldehyde condensation product obtainable by etherification of a product obtained by condensing in presence of alkaline condensing agents formaldehyde and a phenol in which two of the positions o, o and p to the hydroxyl group are unsubstituted. The etherified melamine-formaldehyde condensation product may be made by reacting a methylol melamine or a methylated methylol melamine with a suitable alcohol, e.g. methanol, ethanol, propanol, n-butanol, amyl alcohol, benzyl alcohol, cyclohexanol, or b -ethoxyethanol. Suitable phenols are o-cresol, p-cresol, p-ethylphenol, p-tert.-butyl phenol, p-cyclohexylphenol, or p-phenylphenol. Suitable alcohols for etherifying the phenolic condensation product are propanol, n-butanol, amyl alcohol, benzyl alcohol, cyclohexanol or b -ethoxyethanol. Suitable acidic condensing agents are phosphoric acid, hydrogen halides, sulphuric acid, camphor sulphonic acid, phthalic acid or stannic chloride. The reaction may be performed in a suitable liquid medium, e.g. excess of one of the alcohols used for etherification. It may be performed in two stages, the first below the boiling point of any liquid present, but preferably as high as 100 DEG C. and lasting for a few minutes to several hours. In the second stage, the liquid reaction medium is distilled off, if desired with the aid of reduced pressure or a current of inert gas, e.g. carbon dioxide or nitrogen. The products may be soluble in drying oils, giving varnishes, or may be used, preferably together with a plasticiser, e.g. a castor oil-modified alkyd resin, in solution in lacquer solvents, e.g. xylene or butanol. Examples describe a number of ways of carrying the invention into effect. In each case, a solution of methoxymethyl melamine in n-butanol is employed with phosphoric acid as the catalyst. The times and temperatures of the two stages of the heating treatment and the proportions of catalyst are varied and products of varying solubilities are obtained. Example 1 employs as phenolic material a product obtained by condensing in alkaline solution p-tertiary butyl phenol and formaldehyde, removing the upper aqueous layer and distilling the product with butanol, xylene and phosphoric acid to yield a butanol-xylene solution of the butyl ether. Examples 4 and 5 use a butanol solution of the similarly obtained product from butanol, p-hydroxydiphenyl and formaldehyde. Example 6 employs p-cresol dialcohol as starting material; example 7 p-cyclohexylphenol dialcohol; example 8 p-ethylphenol dialcohol; example 9 o-cresol dialcohol; examples 2, 3, 10, 11, 12 and 13 a p-tertiary butyl - phenol - dialcohol. In each case the phenolic condensates are etherified with n-butanol. Samples have been furnished under Sect. 2 (5) of the Acts. In one case, a butanol-xylene solution of a butylated p-tert.-butyl phenolformaldehyde condensation product is heated for 1 hour at 100 DEG C. with a butanol solution of hexamethoxy-methylmelamine and phthalic acid. The temperature is then raised to 170 DEG C. and solvents distilled off. A light brown resin soluble in tung oil or tung oil-linseed oil results. In the second case, sulphuric acid is used as the acid catalyst. In the third case, p-tertiary butyl phenol dialcohol is etherified with n-propanol and a butanol-xylene solution of the product is heated with hexaethoxymethyl melamine in presence of oxalic acid.