| 摘要 |
1,241,344. Polyalkylene foams. FURUKAWA ELECTRIC CO. Ltd. 12 June, 1969 [13 June, 1968], No. 29840/69. Headings C3C and C3P. A composition adapted for foaming comprises a foaming agent, 99.5 to 70% by weight of a polymer or copolymer of an alkylene and 0À5- 30% by weight of a polymer or copolymer of .butadiene, the butadiene polymer being dispersed in a continuous phase of alkylene polymer. Suitable chemical foaming agents are organic nitroso, aromatic hydrazide or azo compounds, alkali metal or ammonium carbonate, bicarbonate, nitrate or chloride, and physical foaming agents include an alkane, a haloalkane or an " inert " gas. In the examples: (1) mixtures of polybutadiene with polyethylene, isotactic polypropylene or an ethylene/ vinylacetate copolymer are mixed with azodicarbonamide and foamed by the action of heat; (2) mixtures of polybutadiene and polyethylene are mixed with dichlorodifluoromethane or 1,2-dichlorotetrafluoroethane and foamed by heating; (3) a mixture of chlorosulphonated polyethylene and polybutadiene is mixed with sodium bicarbonate and foamed by heating; (4) mixtures of polypropylene and butadiene are mixed with dinitrosopentamethylenetetramine or 1,2-dichlorotetrafluoroethane, and (5) polyethylene, polybutadiene, diatomaceous earth and water are mixed and propane gas is added as foaming agent during heating.
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