| 摘要 |
PROBLEM TO BE SOLVED: To provide a thick polyolefin resin block-shaped foam having foams oriented vertically long in its thickness direction, and a method for producing the same. SOLUTION: A foamable resin mixture consisting of a foaming agent, a crosslinking agent and a polyolefin resin is supplied into a mold constituted of opposed operable molds and a piston to be hermitically sealed therein (1) and the resin mixture hermetically sealed in the mold is pressed and shaped by the piston and heated to the decomposition temp. of the foaming agent or more to generate gas (2). Subsequently, the molten resin is cooled within a range from softening temp. to an m.p. and the piston is set to a speed equal to or lower than the expansion speed of the resin to open the mold and resin foam is cooled and solidified to take out a molded product from the mold (3). In such a state that the slide part of the mold and the piston in the mold is held to temp. lower than the m.p. of the resin by 30 deg.C, the processes 2, 3 are performed and, further, the gel ratio in the resin foam is set to 0-50%. |
