| 摘要 |
Cellular polylactam articles comprising a solids content of 10 to 80% by volume, 5 to 50% of such solids being short fibres of inert material, of modulus 5 to 30 x 106 p.s.i. and of cross-sectional dimension D' 0.1 to 1 mil. and length at least 3D to 125 mils and wherein such fibres are dispersed in the cell walls of the article, the long dimension being parallel to the walls of the cell, are prepared by forming a mixture of a molten monomeric o -lactam, an anionic polymerization catalyst and cocatalyst, a blowing agent and short fibres of inert material as described above and forming the article by polymerizing and foaming the mixture in a suitably-shaped mould. The preferred lactam is e -caprolactam, but lactams having 7 to 16 carbon atoms, methyl cyclohexanone isoximes and cyclic hexamethylene adipamide are also specified. The exemplied catalyst comprises sodium caprolactam and potassium stearate and the cocatalyst comprises the polycarbonate of 2,2-bis-(4-hydroxyphenyl) propane and 2,2,4 - trimethyl - 3 - hydroxy - 3 - pentenoic acid b -lactone. Specified fibres are calcium silicate, glass, slag wool, fibrous potassium titanate and aluminium, steel and copper fibres. A non-fibrous filler may also be present in an amount such that the total wt. of filler does not exceed 60% of the weight of the foam, specified non-fibrous fillers being alumina, aluminium, or calcium silicate, Portland cement or titanium dioxide. The exemplified blowing agents are hexane and dodecenyl azide. The foamed material nay be used as a substitute for wood. |
