PROCESS FOR PREPARING IMPROVED EPOXY RESIN ADHESIVES CONTAINING MINOR AMOUNT OF A URETHANE MODIFIER AND A BISPHENOL TYPE COUPLING AGENT

摘要

1328853 Modified epoxy resins DOW CHEMICAL CO 30 Oct 1970 [31 Oct 1969] 51733/70 Heading C3B An epoxy resin which is a polyglycidyl ether of a polyhydric phenol, a glycol, glycerol or a polyoxyalkylene glycol is first reacted with a polyurethane prepolymer to yield a "methane modified" epoxy resin which is then reacted with a bisphenol coupling agent of formula in which A is a C 1-4 alkylene group, S, S 2 , SO, SO 2 , CO, O.CO.O or O and X is H, Cl or Br, in the presence of a catalyst. The first stage of reaction with the polyurethane prepolymer may take place at 80-90‹ C. for a time sufficient to ensure the complete reaction of the -NCO groups. The bisphenol may then be added and reaction continued until the desired epoxide content is reached. The initial resin may be a diglycidyl ether of bisphenol A and the coupling agent may be bisphenol A. The product may be cured by conventional epoxy resin curing agents. Fillers and conventional extenders may be used. Uses.-Adhesives, especially for metals.