| 摘要 |
1284146 Hollow polyamide foamed articles FARBENFABRIKEN BAYER AG 15 April 1970 [19 April 1969] 17947/70 Headings C3C and C3R Hollow articles of polyamide foam are made by foaming a molten anionically polymerizable and foamable mixture comprising one or more lactams, a basic catalyst and an activator, the mixture being fed into a heated mould which is rotatable about two mutually perpendicular axes, the speeds of rotation about the axes being such that the centrifugal force remains smaller than the gravitational force, the mixture being foamed and polymerized at 120-200‹ C. In the examples, mixtures of caprolactam, sodium formate or borohydride as catalyst, and hexamethylene-1,6-diisocyanate or adduct thereof with caprolactam as activator, together with a silicone stabilizer and aluminium powder as nucleating agent were fed into heated rotatory casting moulds (in the form of a truncated cone) which were rotated about two mutually perpendicular axes, to form closed, hollow articles. |
