GB390000A - Manufacture of resinous condensation products from aromatic amines and formaldehyde - Google Patents

Abstract

In a modification of the process of Specification 266,358, [Class 2 (iii), Dyes &c.], for the production of condensation products useful as substitutes for bone or horn, &c., an aromatic amine or a salt thereof is condensed in an acid medium with about an equivalent amount of formaldehyde, (i.e. with about 1 mol. of formaldehyde for each primary amino group in the amine), and after cooling the mixture to about atmospheric temperature a further amount of formaldehyde is added, and the reaction is allowed to proceed until the mixture gelatinizes; the gel is then treated with an acid-binding agent and dried. Mixtures of aromatic amines or their salts may be used, and a solvent or diluent may be present. Substances yielding formaldehyde may be used instead of formaldehyde. To either or both of the components, or to the reaction mixture at any stage, there may be added other substances such as softeners or fillers; specified additional substances are glycerine, ethylglycol, cellulose, paper pulp, sawdust, ground leather, powdered cork, heavy spars, asbestos, and talc; a dyestuff such as nigrosine, indigo or eosin may also be included. The final products may be treated with impregnating agents such as linseed oil. In the examples, (1) a solution of aniline (1 mol.) in aqueous hydrochloric acid (1 mol.) is treated with formaldehyde (1 mol.), and after cooling the solution formaldehyde (0,75 mol.) is added and the mixture is poured into moulds; after gelatinization, the product is immersed in caustic soda solution and then washed and dried; homologues of aniline, such as m-toluidine, or a - or b -naphthylamine, or mixtures thereof, advantageously with aniline, may be used instead of aniline; (2) a solution of m-toluidine (1 mol.) in aqueous alcoholic hydrochloric acid (1 mol.) is treated with formaldehyde (1 mol.) and the mixture treated after cooling with formaldehyde (0,75 mol.); the gel obtained is pressed, immersed in caustic soda solution, washed, and dried; (3) a mixture of m-toluidine (0,5 mol.) and aniline (0,5 mol.), or (4) a mixture of aniline (0,9 mol.) and benzidine (0,05 mol.) is used instead of toluidine as in example (2); (5) a solution of aniline (0,9 mol.) and a -naphthylamine (0,1 mol.) in aqueous alcoholic hydrochloric acid is used instead of aniline as in example (1); (6) glycerine and alcohol, or (7) ethyl glycol, are included in the reaction mixture of example (1). Reference is made to the use of sulphuric, acetic, or formic acid instead of hydrochloric acid.ALSO:In a modification of the process of Specification 266,358, [Class 22, Cements &c.], for the production of condensation products useful as substitutes for bone or horn, &c., an aromatic amine or a salt thereof is condensed in an acid medium with about an equivalent amount of formaldehyde, (i.e. with about 1 mol. of formaldehyde for each primary amino group in the amine), and after cooling the mixture to about atmospheric temperature a further amount of formaldehyde is added, and the reaction is allowed to proceed until the mixture gelatinizes; the gell is then treated with an acidbinding agent and dried. Mixtures of aromatic amines or their salts may be used, and a solvent or diluent may be present. Substances yielding formaldehyde may be used instead of formaldehyde, To either or both of the components, or to the reaction mixture at any stage, there may be added other substances such as softeners, or fillers; specified additional substances are glycerine, ethylglycol, cellulose, paper pulp, sawdust, ground leather, powdered cork, heavy spars, asbestos, and talc; a dyestuff such as nigrosine, indigo or eosin may also be included. The final products may be treated with impregnating agents such as linseed oil. Examples of the manufacture of the condensation products are given.