| 摘要 |
1,259,155. Expanding polybutene-1. CHEMISCHE WERKE HULS A.G. 29 May, 1969 [30 May, 1968], No. 27180/69. Headings C3C and C3P. Expanded polybutene-1 is made by heating under pressure a foamable mixture containing polybutene-1 and thereafter releasing the pressure on the mixture, the mixture containing in addition to the polybutene-1, 0À1 to 5% of an expanding agent which on heating splits off nitrogen, 0À03 to 2% of an organic peroxide having a decomposition temperature of at least 170‹ C., 0À01 to 1% of sulphur and 0À5 to 3% of a compound having a plurality of allyl groups, all the percentages being by weight based on the weight of the polybutene-1. The heating may be carried out in a mould or extruder. In the examples the foamable mixture consisted of polybutene-1, cyclic perketals of 2,5-dimethyl- 2,5-hexane dihydroperoxide and acetone, sulphur, triallyl cyanurate and azodicarbonamide. |
