| 摘要 |
PURPOSE:To obtain a composition for a resin mold which does not deteriorate a silicone resin matrix, excels in releas-ability from film and is useful for the production of a Fresnel lens by mixing an epoxy resin with an acid anhydride curing agent and a thixotropic agent. CONSTITUTION:An epoxy resin composition for a resin mold is prepared by mixing an epoxy resin (A) (e.g. desirably a bisphenol A epoxy resin which is liquid at room temperature to 70 deg.C) with an acid anhydride curing agent (B) (e.g. methylnadic anhydride) and a thixotropic agent (C) (e.g. colloidal silica of an average particle size of 1-20mum). The mixing ratio among the respective components is such that 0.2-0.7 chemical equivalent, desirably 0.2-0.5 chemical equivalent of component B is used per equivalent of component A, and component C is used in an amount of 0.5-5wt.%, desirably 0.5-3wt.% based on the total weight. |
