| 摘要 |
<p>Use of a composition comprising at least a polyamide matrix and optionally additives, in or for preparing microcellular polyamide particle by injection molding using a fluid in supercritical state, is claimed. Use of a composition comprising at least a polyamide matrix and optionally additives, in or for preparing microcellular polyamide particle by injection molding using a fluid in supercritical state, is claimed, where the polyamide composition has an apparent viscosity in molten phase according to the relation (eta 100= 12.82(X)+239) and (eta 1000= 3.62(X)+139), where eta is the apparent viscosity in molten phase of the polyamide composition measured at a temperature of 15[deg] C higher than the melting temperature of the polyamide composition or at a shearing rate of 100 s -> 1>, eta 100 or at a shearing rate of 1000 s -> 1>, eta 1000 and where X is the weight proportion of heterogeneous dispersed additives in the polyamide matrix, compared to the total weight of the composition. Independent claims are included for: (1) a formulation in the molten state, comprising the composition and a fluid in the supercritical state; and (2) a process for preparing a microcellular polyamide article by injection molding comprising making a formulation in the molten state by mixing the composition with fluid in the supercritical state so as to dissolve the fluid in the supercritical state in the matrix, injecting the formulation obtained in molding chamber of injection molding equipment by subjecting the composition to low pressure to provoke a nucleation and cell growth, and leaving the obtained mixture for solidifying as microcellular polyamide article in the molding chamber.</p> |
