| 摘要 |
PURPOSE:To obtain an unsaturated polyester laminated sheet for electrical use, having low hygroscopicity and excellent punchability, by adding a melamine compound having double bond in the molecule to an unsaturated polyester, and impregnating and curing the obtained composition in a substrate. CONSTITUTION:The objective laminated sheet is produced by compounding (A) an unsaturated polyester obtained by reacting an alpha, beta-unsaturated dibasic acid (e.g. maleic anhydride), a polyhydric alcohol (e.g. ethylene glycol) and if necessary a saturated polybasic acid (e.g. phthalic anhydride, adipic acid, etc.) with (B) a melamine compound having one or more double bonds in the molecule (e.g. a compound obtained by heating melamine, formaldehyde and an alcohol having double bond in the presence of an acid catalyst such as nitric acid) and if necessary (C) a polymerizable monomer (e.g. styrene), and impregnating and curing the obtained unsaturated polyester resin composition in a substrate. |
