One-step impregnation of glass fibre fabric with epoxy! resin - using resin compsn. contg. dicyan-di:amide hardener, di:acetone-alcohol, water and adhesion-improver

摘要

Pre-pregs contg. an epoxy resin-impregnated glass fibre fabric are prepd. by (i) coating the glass fibre fabric with an adhesion-improver; (ii) steeping in a compsn., (A) consisting of dissolved epoxy resin, dicyandiamide, (I), as crosslinking agent, and a solvent for (I), and (iii) hardening under heat and pressure. Improvement comprises (a) using a diacetone-alcohol and water mixt. as solvent for (I); (b) admixing the adhesion-improver to compsn. (A) and (c) impregnating the glass fibre fabric in one step, by soaking in or with the resulting compsn. Pref. the impregnating compsn. is prepd. by using a mixt. of 65 pts. wt. diacetone-alcohol and 13.3 pts. wt. water to dissolve 3 pts. wt. (I) and adding 0.5-1.5 (1) pts. wt. adhesion-improver and 100 pts. wt. epoxy resin. The pre-pregs are used in prodn. of laminated circuits; addn. of adhesion-improver to solvent obviating first wetting and drying step.