| 摘要 |
PURPOSE:To obtain the title foam which can give a composite laminate excellent in adhesiveness and does not cause discoloration of its base, by molding and expanding a polyolefin resin containing a specified amount of a petroleum resin. CONSTITUTION:A polyolefin resin (A) (e.g., ethylene/alpha-olefin copolymer) is mixed with at least 0.5wt.%, preferably, 5-25wt.% natural or synthetic petroleum resin (B) preferably having no polar groups (e.g., hydrogenated alicyclic petro leum resin based on a component of the formula), a blowing agent (e.g., azodicarbonamide) and, optionally, other additives (D). The obtained mixture is molded into a sheet of a uniform thickness and crosslinkages are introduced into this sheet. The resulting sheet is expanded by heating to a temperature higher than the decomposition temperature of component C to obtain the title foam having an apparent density of 0.500-0.020g/cc, a gel fraction of 5-70%, and a closed cell content >=70%. This foam is heat-bonded with, if necessary, a colored iron sheet to obtain a composite laminated.
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