GB865196A - Polymers derived from phenols and unsaturated acetals - Google Patents

Abstract

Polymers are prepared by heating (1) a phenol in which the phenolic hydroxyl groups are all attached to the same aromatic ring and which has at least two active hydrogens ortho or para to the phenolic hydroxyl group, with (2) an unsaturated acetal of general formula:- <FORM:0865196/IV (a)/1> where R1 is H, Cl or methyl and R11 is H or methyl, in the presence of (3) an acid or acid-reacting catalyst. The reaction may be carried out in solution (e.g. xylene or di-n-butyl- or di-isopropyl-ether) or in bulk, and the catalyst may be neutralized for storage purposes (e.g. with Na or Ca carbonate or Na acetate). As the catalyst also functions as a curing agent the preparation and curing of the resins may be carried out in one or two stages. Phenols (1) specified are phenol, mixed cresols, m-xylenol, p-phenyl phenol, p-t-butyl phenol, b -naphthol, coal tar or coal hydrogenation phenols, chlorophenols, resorcinol, hydroquinone, phloroglucinol and, in Example (5), a commercial mixture containing cresols, xylenols, ethyl phenols and higher monophenols. Acetals (2) specified are those in which the unsaturated group is vinyl, propenyl, isopropenyl and 1-chlorovinyl; they may be prepared from pentaecrythritol and the appropriate unsaturated aldehyde. Catalysts (3) specified are sulphonic acids (benzene, toluene and mixed ethyl, methyl and propyl) sulphuric or phosphoric acid, chlorides of Al, Sn, Fe, Zn or Ti, and, particularly when metals are present, dialkyl sulphates of C1-4; in Example (13) a mixture of phosphoric and mixed ethyl, methyl and propyl sulphonic acids are used. Optional additives are Fe, Al, wood flour, asbestos and diatomaceous earth. Uses: shell moulds; grinding wheels; glass fibre laminates; potting; encapsulating; casting; coating; and moulding. Specification 865,197 is referred to.