GB794646A - Improvements in aromatic-hydrocarbon-aldehyde resins - Google Patents

Abstract

Resinous products suitable for spray coating steel panels, for use as varnishes, as binders for laminates and for moulding are obtained by reacting an aromatic hydrocarbon-aldehyde resin with (a) an ether derivative of a methylol phenol having the general formula <FORM:0794646/IV (a)/1> where R is a saturated or unsaturated aliphatic hydrocarbon radical, or (b) a methylol phenol ether as in (a) in admixture with ethers of formula <FORM:0794646/IV (a)/2> where n=1 or 2. An epoxide resin may be mixed with (a) or (b). The aromatic hydrocarbon-aldehyde resin may be of the general formula <FORM:0794646/IV (a)/3> where Ar may be xylyl-, naphthyl-, anthracyl-, or mesityl and Z is H or alkyl, aryl, araryl or a heterocyclic O containing radical, i.e. furfuryl, and m is greater than 1. Aromatic hydrocarbon-aldehyde resins specified are xylene-formaldehyde and phenol-modified xylene-formaldehyde resins. The epoxide resins are phenolic or polyhydric ethers obtained by reaction of epoxy compounds or epihalohydrins with polyhydric phenols or alcohols as described in Specifications 518,057 and 579,698, [both in Group IV]. The ether derivatives of methylol phenols are obtained as described in Specification 712,588 and mixed allyl ethers are preferably employed. Suitable aromatic hydrocarbon-aldehyde resins are obtained (1) by reacting 795 parts m-xylene with 450 parts paraformaldehyde in presence of 2500 parts 50 per cent H2SO4 at 65 DEG C. for half an hour, separating the acid layer and steam distilling the resinous layer to remove unreacted xylene. Example 2 describes a similar resin obtained from commercial xylene. (3) 62.5 parts of an 80 per cent solution of the xylene formaldehyde resin of Example (1) are reacted with 100 parts of a 50 per cent solution in butanol of mixed allyl ethers of polymethylol phenols prepared as described in Specification 712,588. In Example 6 the use of a phenol-modified aromatic hydrocarbon-formaldehyde is described. Comparative tables illustrating the chemical and physical properties of the following resins are given: (1) epoxide resin; (2) 50/50 mixture of allyl polymethyl phenol ethers and an epoxide resin; (3) 50/50 mixture of allyl polymethylol phenol ethers and xylene-formaldehyde resin; (4) 50/50 mixture of allyl polymethylol phenol ethers and a bisphenol modified xylene formaldehyde resin; (5) xylene-formaldehyde-epoxide resin; (6) phenol modified xylene-formaldehyde resin and epoxide resin; (7) phenol modified xylene-formaldehyde resin and allylpolymethylol phenol ethers; (8) commercial phenol-aldehyde resin - epoxide resin mixture. Specification 794,647 also is referred to.