GB359147A - Improvements in the manufacture and production of artificial masses - Google Patents

Abstract

For the manufacture of solutions of condensation products useful as lacquers, urea (or thiourea) and formaldehyde (or a polymer thereof), or the mono-or di-methylol derivatives of urea or thiourea or the anhydrides obtainable therefrom, or mixtures of these, are heated under pressure in an hydroxylated organic solvent to a temperature above 100 DEG C., preferably between 120 DEG and 160 DEG C. The pressure is applied by effecting the reaction in a closed vessel, and depends on the solvent selected. Solvents boiling above 100 DEG C. are preferred such as n- or iso-butyl alcohol, benzyl alcohol, or ethylene glycol monoacetate, but methyl, ethyl, or propyl alcohol may also be used. The condensation is preferably effected in the absence of water and in the presence of a condensing agent, which may be of acid, neutral, or alkaline reaction. The solutions of condensation products may be used as lacquers, directly or after addition of esters, ketones, hydrocarbons, cellulose carboxylates or ethers, nitrocellulose, blown animal or vegetable oils, softeners such as triaryl phosphates or phthalic esters, or fillers, &c. In the examples, (1) a suspension of trioxymethylene in n-butyl alcohol is treated with aqueous caustic soda until the trioxymethylene has dissolved, and then neutralized with sulphuric acid; urea is then added, and the mixture is heated in an autoclave to 135 DEG C., yielding a solution useful as a varnish; (2) dimethylol urea in iso-butyl alcohol is heated in an autoclave to 135 DEG C., yielding a solution which is steam-distilled to recover the solid condensation product; the latter may be worked up into a lacquer by dissolving it in a mixture of butyl alcohol, butyl acetate, ethyl alcohol, and toluene, together with nitrocellulose and blown castor oil; (3) dimethylol urea and dimethylol thiourea in iso-butyl alcohol are treated in an autoclave to 120 DEG C., in the presence of a little formic acid, yielding a solution of a condensation product. Specifications 262,148, [Class 2 (iii), Dyes &c.], 266,752 and 296,361, [both in Class 95, Paints &c.], are referred to.ALSO:Urea (or thiourea) and formaldehyde (or a polymer thereof), or the mono- or di-methylol derivatives of urea of thiourea or the anhydrides obtainable therefrom, or mixtures of these, are heated under pressure in an hydroxylated organic solvent to a temperature above 100 DEG C., preferably between 120 and 160 DEG C., the amount of solvent being such that the initial materials and/or the final products are completed dissolved. The pressure is applied by effecting the reaction in a closed vessel, and depends on the solvent selected. Solvents boiling above 100 DEG C. are preferred, such as n- or iso-butyl alcohol, benzyl alcohol, or ethylene glycol monoacetate, but methyl, ethyl, or propyl alcohol may also be used. The condensation is preferably effected in the absence of water and in the presence of a condensing agent, which may be p of acid, neutral, or alkaline reaction. Generally, the process yields solutions of condensation products, which may be used directly as lacquers, if desired after addition of esters, ketones, hydrocarbons, cellulose carboxylates or ethers, nitrocellulose, blown animal or vegetable oils, softeners such as triaryl phosphates or phthalic esters, or fillers, &c. Alternatively, the solutions obtained may be steam-distilled, or treated with organic precipitants such as ether or benzene, to recover solid condensation products, which may be moulded under heat. In the examples, (1) a suspension of trioxymethylene in n-butyl alcohol is treated with aqueous caustic soda until the trioxymethylene has dissolved, and then neutralized with sulphuric acid; urea is then added, and the mixture is heated in an autoclave to 135 DEG C., yielding a solution useful as a varnish: (2) dimethylol urea in iso-butyl alcohol is heated in an autoclave to 135 DEG C., yielding a solution which is steam-distilled to recover the solid condensation product; the latter may be moulded, alone or with a filler such as cellulose, or may be worked up into a lacquer by dissolving it in a mixture of butyl alcohol, butyl acetate, ethyl alcohol, and toluene, together with nitrocellulose and blown castor oil; (3) dimethylol urea and dimethylol thiourea in isobutyl alcohol are heated in an autoclave to 120 DEG C. in the presence of a little formic acid, yielding a solution of a condensation product. Specifications 262,148, 266,752, and 296,361, [all in Class 2 (iii), Dyes &c.], are referred to.