| 摘要 |
PURPOSE:To enable the cast object to which the casting face of the copolymer resin of methylmethacrylate, styrene and maleianhydride containing inorganic filler is surely transferred, to be produced by using a specified amount of alkyl ester of a specified oxypolycorboxylic acid as an inner mold release agent. CONSTITUTION:The composition for casting is the monomer mixture composed methylmethacrylate, styrene and maleicanhydride. In said composition for casting, while total amount is set as standard, 20-80 pts.wt. of monomer mixture composed of 20-80wt.% of methlymethacrylate, 20-80wt.% of styrene and 1-25wt.% of maleicanhydride is mixed with 80-20 pts.wt. of inorganic filler so that the total amount is 100 pts.wt. When this composition for casting is cast, 0.05-5 pts.wt. of the alkylester of oxypolycarboxylic acid having 5-34 carbon atoms contained in one alkyl group constituting ester group, is added to 100 pts.wt. of said composition for casting. When said added amount is less than 0.05 pts.wt., the improving effect of mold release characteristics is reduced, and when said added amount exceeds 5 pts.wt., its physical property is lowered. |
