Hydrous polyolefin resin composition, pre-expanded particles, their preparation and foamed molded article comprising the same

摘要

A hydrous resin composition suitable for the preparation of a polyolefin resin preliminary foamed particle containing a polyolefin resin and a hydrophilic polymer and having a water content of 1 to 50% by weight is preliminarily foamed and the hydrous resin composition is preliminarily foamed, and the foaming factor of 5 to Polyolefin resin preliminary foam particles with an independent bubble rate of 80 to 100% and an average bubble diameter of 50 to 500. Mu. M. The preliminary foamed particles are formed by dispersing resin particles comprising polyolefin resin and hydrophilic polymer in a closed container in a closed container to form a dispersion solution, and heating them to a temperature above the softening temperature of the polyolefin resin, and water content. As the water-soluble resin particles having a rate of 1 to 50% by weight, and the aqueous dispersion of the aqueous dispersion is released from the closed container into an atmosphere of less pressure than the internal pressure of the closed container to foster the water containing resin particles, it is possible to manufacture without using the volatile blowing agent. The release of the dispersion from the closed vessel is carried out in the closed vessel.When the internal pressure is applied to 25 to 75 kg / cm. Sup. 2 g, the preliminary foaming particles capable of providing a high foaming magnification foam having good physical properties can be obtained.