| 摘要 |
PURPOSE:To obtain an MMA-type SMC free from stickiness, handleable easily, and giving a molded article free from white spots even by compounding a filler, by irradiating a sheet molding compound (SMC) with radiation to effect the polymerization of the MMA monomer near the surface of the SMC. CONSTITUTION:100pts.wt. of methyl methacrylate (MMA) [<=20wt% of the MMA may be substituted with a monomer copolymerizable with MMA (e.g. acrylic acid, methacrylic acid)] is mixed with 1-10pts. of a photosensitizer (e.g. benzoin), a radical polymerization initiator (preferably having a half-life time of 10hr at >=70 deg.C), an MMA polymer, a polymerization accelerator, a filler (e.g. aluminum hydroxide), etc. The objective MMA-type SMC can be produced by covering the obtained SMC with a transparent film, and irradiating with ultraviolet radiation to cause the radiation polymerization of the MMA monomer at the surface layer of the SMC to the depth of 5-200mum, preferably 10-100mum.
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