GB794647A - Modified aromatic-hydrocarbon-aldehyde resins - Google Patents

Abstract

Resinous products suitable for use in moulding or of coating compositions, as binders for laminates, and for casting are obtained by reacting aromatic hydrocarbon-aldehyde resins with epoxide resin. The aromatic hydrocarbon-aldehyde resins have the general formula <FORM:0794647/IV (a)/1> where Ar represents aromatic hydrocarbon radicals and Z is hydrogen, alkyl, alkaryl, aralkyl, and heterocyclic oxygen containing radicals (i.e. furfuryl when the aldehyde employed is furfural), and m is 2-20 with an epoxide resin containing more than one epoxy group per mol. and obtained by reacting epihalohydrin with polyhydric phenols or alcohols, e.g. as described in Specifications 518,057 and 579,698, [both in Group IV]. The aromatic hydrocarbon-aldehyde resin may be phenol-modified. The aldehyde resins may be 30-70 per cent by weight of the epoxide resin. The reaction is carried out at 100-180 DEG C. in presence of phosphoric acid as catalyst. In examples: (1) 795 parts m-xylene are reacted in presence of 2500 parts 50 per cent H2SO4 and 450 parts paraformaldehyde at 80-85 DEG C. The upper layer was steam distilled to remove excess xylenes and dissolved in benzene, washed and recovered by distilling off the benzene; (2) a similar resin was prepared from commercial xylene; (3) 62.5 parts of the resin (1) were reacted with 125 parts epoxy resin solution in diacetone alcohol-xylol in presence of 1 part 85 per cent phosphoric acid; (4) the resin of Example 1 was modified by reaction with phenol and the product reacted with an epoxy resin.