Resin composition for foam molding, foam, and process for producing foam

Abstract

A resin composition for foams which comprises a branched rubbery olefin-based flexible resin (C) obtained by reacting an organic-peroxide-crosslinkable olefin copolymer rubber (A) with an organic-peroxide-decomposable crystalline olefin resin (B) through kneading, the resin (C) having a microcoagulated structure in which the organic-peroxide-crosslinkable olefin copolymer rubber (A) is present as a continuous phase and the organic-peroxide-decomposable crystalline olefin resin (B) is present as a discontinuous phase in the continuous phase. Use of this resin composition can provide foamed articles which are usable as, e.g., interior automotive parts, can have expansion ratios ranging from a high to a low value, are flexible, are excellent in cushioning properties, heat-insulating properties, and in-mold foamability, and have suitability for recycling.

Description

technical field [0001] The present invention relates to a resin composition for foam molding, a foam, and a method for producing the foam. Specifically, the present invention relates to an olefin-based resin composition capable of obtaining a foamed molded body that can be used in automobiles, a foam obtained by using the resin composition, and a method for producing the foamed body. Used for interior material parts, etc., the degree of freedom of expansion ratio is high, and it can be a low-foaming to high-foaming body, which is soft and has excellent cushioning, heat insulation, and recyclability. Background technique [0002] Conventionally, in in-mold foam molding, polyurethane foam has been used as a foaming material with a high expansion ratio, excellent in-mold molding processability, and soft touch or cushioning properties. However, polyurethane foam is a thermosetting resin. In terms of material recycling, although it can be reused as foam scraps, there are still m...

AI Technical Summary

Problems solved by technology

That is, the inventors of the present invention have found that when the techniques disclosed in JP-A-54-112967 and JP-9-143297 are used, (i) it is necessary to add a foaming agent to the base material before foam molding. Dispersion, dissolution, and dissolution, so when the crosslinking density (gel fraction) of the matrix material increases, the foaming agent cannot be uniformly dispersed, dissolved, and dissolved in the matrix material; (ii) thus, the foaming agent that has been formulated The agent cannot effectively promote foaming; (iii) the result is that the foaming ratio does not increase

Furthermore, the inventors of the present invention have also found out through their own studies that when these disclosed techniques are used, (iv) due to the increase in viscosity, the shearing to the matrix resin becomes significant, and when the blowing agent is dispersed, the matrix material will be dissipated. Changes in the microcohesive structure, accompanied by decomposition of the matrix resin due to shear; (v) resulting in an extreme drop in flow viscosity, high foaming in the forming die and mold, or unstable control of the formed shape

[0009] As described above, none of the proposals proposed so far have been able to provide an in-mold foam with soft cushioning properties that is excellent in recyclability or in-mold molding processability, and has a high expansion ratio of the cushion layer and excellent texture. Foam products

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