Patent GB-372076-A (GB)
Title: Manufacture of artificial resins
IPC: C08G12/08
Filed: 1931-04-20
Abstract: The resins prepared by condensing an aromatic amine with more than an equimolecular amount of formaldehyde in the presence of about an equimolecular amount of an acid, are united with an additional amount of an aldehyde and/or of a substance yielding aldehyde, sufficient to bring the aldehyde content of the final resin to substantially more than 1,1 mol. for each mol. of amine.  The moulding properties of the resins and the chemical resistance of the moulded products are thus modified.  Suitable aldehydes are paraformaldehyde, furfurol, crotonic aldehyde, paraldehyde, oenanthic aldehyde, benzaldehyde, and salicyl aldehyde and its p-toluenesulphonic ester; as substances yielding aldehyde there may be used furfuramide, hexamethylene-tetramine and phenol polyalcohols.  The aldehyde or substance yielding aldehyde may be added before the drying and comminution of the resin (cf. Specification 372,075), or the dry components may be ground or melted together, with or without the aid of a solvent. At any stage of the process, the resin may be mixed with a flux, e.g. an aldehyde condensation product which does not split off aldehyde (cf. Specification 342,730); a filler may also be present, e.g. paper pulp, wood meal, asbestos, paper, or textile fabric.  The speed of hardening of the products may also be influenced by addition of acids or of basic substances such as furfuramide or triethanolamine.  According to examples 1-6 and 9, resins prepared from aniline and more than an equimolecular amount of formaldehyde in the presence of hydrochloric acid are mixed with crotonic aldehyde, furfurol, paraformaldehyde and hexamethylene-tetramine, p-cresoldimethylol and furfurol, p-cresoldimethylol and salicylic acid, furfurol and furfuramide, and a condensation product from urea (1 mol.) and formaldehyde (2 mols.) respectively.  In the other examples, (7) a solution obtained by condensing aniline with more than an equimolecular amount of formaldehyde in the presence of hydrochloric acid, is poured into a mixture of phenol-poly-alcohols prepared by condensing an alkaline solution of phenol with an excess of formaldehyde in the cold; the mixture is neutralized with sodium carbonate, heated and filtered; instead of phenol, its homologues or p-dioxydiphenylpropane may be used for the preparation of the phenol-alcohols; (8) minor variations in the procedure of example 7 are described; (10) a solution obtained by treating aqueous anhydroformaldehyde aniline with hydrochloric acid and formaldehyde is treated as in example 7, and the product is poured into a magma of paper pulp, neutralized, filtered and washed; the filter residue can be worked up in a hollander and made into paper in the usual manner.  The purposes for which the products may be used include the manufacture of loud-speakers and other acoustic appliances.  Specifications 284,589, [Class 2 (iii), Dyes &c.], 342,325, 342,326, 342,723, 342,767, and 343,882 also are referred to.ALSO:The resins prepared by condensing an aromatic amine with more than an equimolecular amount of formaldehyde in the presence of about an equimolecular amount of an acid, are united with an additional amount of an aldehyde and/or of a substance yielding aldehyde, sufficient to bring the aldehyde content of the final resin to substantially more than 1,1 mol. for each mol. of amine.  The moulding properties of the resins and the chemical resistance of the moulded products are thus modified.  Suitable aldehydes are paraformaldehyde, furfurol, crotonic aldehyde, paraldehyde, oenanthic aldehyde, benzaldehyde, and salicyl aldehyde and its p-toluenesulphonic ester; as substances yielding aldehyde there may be used furfuramide, hexamethylenetetramine and phenol-polyalcohols. The aldehyde or substance yielding aldehyde may be added before the drying and comminution of the resin (cf. Specification 372,075), or the dry components may be ground or melted together, with or without the aid of a solvent. At any stage of the process the resin may be mixed with a flux, e.g. an aldehyde condensation product which does not split off aldehyde (cf. Specification 342,730); a filler may also be present, e.g. paper pulp, wood meal, asbestos, paper, or textile fabric.  The speed of hardening of the products may also be influenced by addition of acids or of basic substances such as furfuramide or triethanolamine.  According to Examples 1-6 and 9, resins prepared from aniline and more than an equimolecular amount of formaldehyde in the presence of hydrochloric acid are mixed with crotonic aldehyde, furfurol, paraformaldehyde and hexamethylenetetramine, p-cresoldimethylol and furfurol, p-cresoldimethylol and salycylic acid, furfurol and furfuramide, and a condensation product from urea (1 mol.) and formaldehyde (2 mols.) respectively.  In the other examples, (7) a solution obtained by condensing aniline with more than an equimolecular amount of formaldehyde in the presence of hydrochloric acid, is poured into a mixture of phenol-polyalcohols prepared by condensing an alkaline solution of phenol with an excess of formaldehyde in the cold; the mixture is neutralized with sodium carbonate, heated and filtered; instead of phenol, its homologue or p-dioxydiphenylpropane may be used for the preparation of the phenol-alcohols; (8) minor variations in the procedure of Example 7 are described; (10) a solution obtained by treating aqueous anhydroformaldehyde aniline with hydrochloric acid and formaldehyde is treated as in Example 7, and the product is poured into a magma of paper pulp, neutralized, filtered and washed; the filter residue can be worked up in a hollander and made into paper in the usual manner.  Specifications 284,589, [Class 22, Cements &c.], 342,325, [Group IV], 342,326, 342,723, 342,767, and 343,882 also are referred to.