| 摘要 |
A method for making cast precision epoxy resin bodies and an epoxy resin formulation for use therein, the epoxy resin formulation having Component A consisting essentially of from 40 to 70% by weight epoxy novolac polymer, from 30 to 50% by weight vinyl -3-cyclohexene diepoxide and from 0 to 20% by weight 3,4 epoxy cyclohexylmethyl -3,4-epoxy cyclohexane carboxylate and Component B consisting essentially of partially hydrolyzed aryl tetracarboxylic acid dianhydride, preferably partially hydrolyzed pyromellitic acid dianhydride. In the preferred embodiments a tertiary amine catalyst is also included. These components are mixed, just before use, in a ratio of from 20 to 50 parts by weight Component B to each 100 parts by weight Component A. To make the cast precision bodies such mixture is cast in a mold of the shape desired, allowed to cure to a solid body while in the mold, and thereafter heated to cause permanent expansion thereof at least sufficient to compensate for any shrinkage occurring during the casting and hardening thereof while in the mold.
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