GB287177A - Moulding compositions - Google Patents

Abstract

287,177. Ripper, K. March 18, 1927, [Convention date]. Samples furnished. Dicyandiamide-aldehyde condensation products. - Dicyandiamide is condensed with formaldehyde or a polymer thereof, in the presence or absence of other substances capable of combining with formaldehyde to give resins, to form hydrophobe products which are converted by cold water into fine powders which can be moulded by heat and/or pressure. Of the other substances capable of combining with formaldehyde, urea, thiourea and phenols are mentioned. Prior to moulding, the powders may be mixed with fillers such as asbestos, cellulose, cotton flock, wood pulp, sawdust, wood flour, cork, flax, wool, silk, leather, or with softening agents, plasticizers or fluxes. The products are useful as insulating material and glass substitutes, and for the manufacture of porcelain, trinkets, &c. Examples are given of the preparation of condensation products from (1) dicyandiamide (1 mol.) and aqueous formaldehyde (1 mol.) ; (2) dicyandiamide (1 mol.), urea (1 mol.), and aqueous formaldehyde (2 mols.) ; (3) dicyandiamide (1 mol.), thiourea (1 mol.), and aqueous formaldehyde (2 mols.); (4) dicyandiamide (1 mol.), phenol (1 mol.), and aqueous formaldehyde (2 mols.); (5) dicyandiamide (1 mol.), phenol (2 mols.), aqueous formaldehyde (3 mols.); (6) dicyandiamide (1 mol.), cresol (1 mol.), and aqueous formaldehyde (2 mols.). In each case, the product is poured into cold water, when a hydrophobe resin separates out and is transformed into a fine powder. Specification 208,761 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the use of any aldehyde and of derivatives of dicyandiamide. The initial condensation products of formaldehyde with urea, thiourea, phenols &c., such as methylolurea, methylolthiourea, phenol- or cresolalcohols may also be employed. This subjectmatter does not appear in the Specification as accepted.