JP2021021036A5 - - Google Patents

Claims (15)

It is a foamed sheet obtained by foaming a foamable composition containing at least a polyolefin resin, has a 25% compressive strength of 50 to 750 kPa, and has a stress retention rate of 70% or more when 25% compression is repeated 30 times. Foam sheet. The foamed sheet according to claim 1, wherein the 10% compressive strength is 30 to 150 kPa. The foamed sheet according to claim 1 or 2, wherein the ratio of 10% compressive strength to 25% compressive strength [100 × (10% compressive strength / 25% compressive strength)] is 20 to 95%. The foamed sheet according to any one of claims 1 to 3, wherein the foaming ratio is 2 to 20 cc / g. The foamed sheet according to any one of claims 1 to 4, which has a thickness of 0.1 to 1.0 mm. The foamed sheet according to any one of claims 1 to 5, wherein the bubble flatness represented by the following formula (1) is 50 to 1000%.
100 × average cell diameter in MD direction × average cell diameter in TD direction / (average cell diameter in ZD direction) ² ... (1) The foamed sheet according to any one of claims 1 to 6, which has an average cell diameter of 30 to 200 μm. The foamed sheet according to any one of claims 1 to 7, wherein the closed cell ratio is 75% or more. The foamed sheet according to any one of claims 1 to 8, wherein the gel fraction is 20 to 70% by mass. The foamed sheet according to any one of claims 1 to 9, wherein the hysteresis loss at the time of 25% compression is less than 30%. It is a foamed sheet obtained by foaming a foamable composition containing at least a polyolefin resin, has a 25% compressive strength of 100 to 300 kPa, and has a stress retention rate of 90% or more when 25% compression is repeated 30 times. The 10% compressive strength is 50 to 90 kPa, the ratio of the 10% compressive strength to the 25% compressive strength [100 × (10% compressive strength / 25% compressive strength)] is 30 to 95%, and at the time of 25% compression. Foam sheet having a hysteresis loss of 1% or more and less than 20%. The foam sheet according to any one of claims 1 to 11 , which is used as a cushioning material for a printing roll. A laminate comprising the foamed sheet according to any one of claims 1 to 12 and adhesive layers provided on both sides of the foamed sheet. A laminate comprising the foamed sheet according to any one of claims 1 to 12 and a support provided on at least one surface of the foamed sheet. The laminate according to claim 14 , further comprising an adhesive layer or an adhesive layer on both sides.