| 摘要 |
<p>Nylon plates are produced from a thermoplastic polyamide with a mol. wt. above 10,000 and a Vicat softening point of 150-300 degrees C contg. monomer units of formula I or II: -NH-R-NH-CO-R1-CO- (I) -CO-R2-NH- (II) (where R and R1 are each 4-13C alkylene, m-or p-phenylene or 1,4-cyclohexene; R1 can be a direct bond; and R2 is 3-5C alkylene or 1,4-cyclohexene), and consist of a core of foamed nylon material and a covering skin of nylon material forming a unit with the core, the foam having an average pore diameter below 1.5 mm and being almost free of pores with a diameter above 3mm, the thickness of the covering skin being 0.2-3 mm, the total thickness of the plate being 2.5-25 mm, the average density of the plate being 0.2-0.9 g/cm3, and the relation between the impact strength (S) in Jonkes, and the weight per surface unit (w) in g/cm2 being such that: 1010gS / W 2.</p> |
