GB783764A - - Google Patents

Abstract

783,764. Curing epoxide resins. CHEMISCHE WERKE ALBERT. April 30, 1956 [April 28, 1955], No. 13266/56. Class 2 (5). [Also in Group IV (b)] Epoxide resins having on the average more than one epoxide group per molecule are hardened by addition thereto of an organo-tin compound having the general formula where n is an integer, R 1 and R 2 , which may be the same or different, are monoacyl groups where n=1 or alternatively where n is greater than 1 are alkyl, aryl or alkaryl groups or residues of maleic acid and R 3 and R 4 are alkyl, aryl or aralkyl. R 1 and R 2 are preferably acyl groups containing 2-22 atoms. Examples of hardening agents are dibutyl tin diacetate and dibutyl tin dilaurate. The hardening agent may contain the recurring unit e.g. compounds such as dibutyl tin maleate obtained by reacting a dialkyl tin dichloride and maleic acid dibutyl tin di-ethylhexoxide polymer may also be used. The polymeric compounds may be produced by reacting a dialkyl, diaryl or diaralkyl tin halide in an anhydrous solvent with alkalimetal alkoxides or with alcohols in the presence of ammonia or tertiary amines. The hardening agent and the epoxide resin may be mixed by melting together or by solution in a mutual solvent, e.g. dichlorethylene, carbon tetrachloride, dichlorethylene ethers, monochlorbenzene. In examples: (1) 100 parts epoxide resin produced from bisphenol and epichlorhydrin are dissolved in ethylene glycol containing 1 part of dibutyl tin laurate. Films of high gloss and good chemical resistance are produced by stoving the solution on metal panels at 200‹ C.; (2) dibutyl tin maleate is used to cure the resin of (1); (3) the hardener was obtained by reacting a dispersion of metallic sodium with 2-ethylhexyl alcohol in toluene with dibutyl tin dichloride. Specification 729,258 is referred to.