Abstract: The present invention relates to a light-sensitive resin composition that has resistance to heat and chemicals, is particularly adapted for use in the formation of a protective film for chemical plating and which is also improved in resistance to the heat of soldering. This light-sensitive resin composition contains (a) a polyurethane (meth)acrylate, (aa) a bisphenol type epoxy (meth)acrylate, (b) a linear high-molecular weight compound, and (c) a polymerization initiator which generates free radicals upon exposure to light. This resin composition is applicable to the manufacture of printed circuit boards by the additive process.

Abstract: In a process for fabricating a printed circuit board, a positive resist layer is electrodeposited on a copper clad laminate to ensure that the walls of through-holes in the substrate are completely coated with the resist, or alternatively, a film having a positive resist layer coated thereon is thermocompressed onto the copper clad laminate with the film being in contract with the latter, so as to cover both top and bottom of each through-hole. By subsequent treatments including resist exposure, development, copper foil etching and resist stripping, a high-density wiring pattern can be formed on the substrate in a uniform and consistent way even if through-holes exist in the substrate.

Abstract: A flame retardant liquid rubber composition comprises a hydrogenated polyhydroxybutadiene polymer and castor oil, which are modified with an isocyanate having the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 respectively represent a lower alkyl group or hydrogen atom and n is an integer of 1 to 4, and alumina hydrate and magnesium hydroxide. The castor oil can be incorporated before adding said isocyanate or can be converted into an isocyanate prepolymer by reacting with said isocyanate before the addition.