| 摘要 |
<p>1,159,636. Epoxy resin-bonded laminates. RHONE POULENC S.A. 20 Feb., 1968 [24 Feb., 1967], No. 8280/68. Heading B5N. [Also in Division C3] Epoxy resin compositions, preferably comprising epoxy resins containing more than 3 epoxy groups per molecule, and as hardener a dianhydride of formula in which A represents an azo or azoxy group are used in the preparation of laminates, especially from glass-fibre materials. In an example, 100 g. of a tetraglycidyl ether resin (EPON 1031, Shell Chemicals) is cured with 18.3 g. of azophthalic anhydride. The curing agent is added to an acetone solution of the resin and the resultant mixture used to impregnate glass cloth. The impregnated cloth is dried at 40‹ C. Then 16 portions of equal dimensions are stacked to form a laminate. Curing takes place in a press at 32 kg./cm.<SP>2</SP> for 40 minutes at 154‹ C., followed by an oven cure at 230‹ C. for 15 hours.</p> |
