GB1461127A - Epoxy resins - Google Patents

Abstract

1461127 Modified epoxy resins DOW CHEMICAL CO 12 March 1974 [12 March 1973] 10965/74 Headings C3B and C3P A modified curable epoxy resin is made by (1) reacting an epoxy resin (E) with, by wt. 0À03- 0À2 parts, based on (E), of (M) a modifying copolymer of 70-90% butadiene and 30-10% acrylonitrile and/or methacrylonitrile, (M) having pendant reactive COOH, OH, or SH groups, and thereafter (2) vulcanizing the polymer with an organic peroxide or S. The vulcanization may be performed at 120-160‹ C. (M) may have av. MW 2000-20,000 and reactive-group functionality 1À2-5. (E) may be an epoxynovolac resin, a liquid epoxy resin (L); or the reaction product of (L) with (H) a dihydroxylic compound; or (L) may be mixed with (M) and (H) and heated with a catalyst; or (L) may first be reacted with (M), and the product reacted with (H). In examples, (L) is a glycidyl ether of bisphenol A or F, and (H) is bisphenol A or S. The reaction between epoxy resin (E) and copolymer (M) may be performed at 80-150‹ C. with a catalyst, e.g. (tetrabutyl phosphonium acetate/acetic acid) complex in methanol; or the catalyst may be a tertiary amino or quaternary ammonium compound. The modified epoxy resin may be cured with usual curing catalysts or curing agents, and usual modifiers or additives may be included: in examples these include Al powder, colloidal silica, dicyandiamide, dichlorodiphenyl-dimethylurea, melamine, and polyethylene polyamines. Unmodified epoxy resin may additionally be present. The modified resin and the curing agents may be put up in separate parts of a two-part pack. Use.-Adhesive; coatings, e.g. on stainless steel or optionally chromate-etched Al; laminates.