| 摘要 |
PURPOSE:To obtain the titled particles which can consistently give a molding excellent in appearance, mechanical properties, etc., by using an olefin resin which has a specified relationship between the logarithm of its melt tension measured at varied temperatures and the resiprocal of the absolute temperature as a base. CONSTITUTION:In-mold expansion-modable particles prepared by usng, as a base, a polyolefin resin which gives a line of a gradient <=1,500 when the logarithm of its melt tension measured at varied temperature is plotted as an ordinate and the reciprocal of the absolute temperature as an abscissa. When the gradient of the melt tension against the temperature is 1,500 or larger, it is difficult to control, for example, a cell diameter or an expansion ratio in the production of pre- expanded particles. As the olefin resins used, low-density polyethylene, medium- density polyethylene, linear low-density polyethylene, ethylene/propylene random copolymers, etc., are preferable, because the production of pre-expanded particles can be easily performed. An uncrosslinked olefin resin is economical as said olefin resin if it can provide a temperature gradient of 1,500 or smaller.
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