| 摘要 |
<p>PURPOSE:To provide a foam which has a thin skin and exhibits an elestic cusioning ability under a high load, by extrusion-expanding a mixture of a polyolefin and a polystyrene in the presence of a hydrogenated styrene/butadiene block copolymer having a specified composition. CONSTITUTION:A styrene/butadiene block copolymer having a styrene content of 10-38wt% and a 1,2-bonded butadiene unit content of 20-50wt% is hydrogeneated. A resin mixture compsn. contg. a polyolefin resin and a polystyrene resin is extrusion-expanded in the presence of said hydrogenated styrene/ butadiene block copolymer. In this way, the title foam having a this skin layer wherein the structural index S of the foam surface represented by the formula (wherein t is the total light transmittance of the skin layer; T is the total light transmittance of the inner layer) is 0.65 or above can be obtd. The term 'skin layer' as used herein refers to a layer obtd. by cutting a layer having a thickness of three times the average cell diameter of the foam from the surface of the foam toward the inside thereof.</p> |
