Foams, foaming compositions and applications thereof

摘要

[Objects] It is an object to provide a foam having a low specific gravity and a small compression set, more preferably a foam having a low specific gravity, a small compression set and uniform quality, a foaming composition, and applications of the foam.;[Means for Solution] The foam is obtained by foaming an olefin polymer, wherein the foam has a specific gravity (d) in the range of 0.03 to 0.30, and a compression set (CS, %) and the specific gravity (d) satisfy the formula of CS≦−279×(d)+95. The foam is preferably obtained from a foaming composition that includes an ethylene polymer (A) including a specific ethylene/α-olefin copolymer (A1) and an ethylene/polar monomer copolymer (A2) in a specific mass ratio, and a specific ethylene/C3-20 α-olefin/non-conjugated polyene copolymer (B).

主权项

1. A foam obtained by foaming an olefin polmer wherein the foam has a specific gravity (d) in the range of 0.03 to 0.30, and a compression sct (CS, %) and the specific gravity (d) satisfies the following formula:
CS≦−279×(d)+95;and
wherein the foam is obtained by heating an ethylene polymer composition comprising an ethylene polymer (A) in an amount of 85 mass % to 93 mass % and an ethylene/propylene/non-conjugated polyene copolymer (13) in an amount of 7 mass % to 15 mass % (the sum of (A) and (B) is 100 mass %) and a azodicarbonamide (C) in an amount of 5 to 6 parts by mass relative to the total 100 parts by mass of the olefin polymers, wherein the non-conjugated polyene is 5-ethylidene-2-norbornene and/or 5-vinyl-2-norbornene: the component (A) comprising (A1) an ethylene/1-butene copolymer in which (a1) a density (ASTM D1505, 23° C.) is in the range of 0.857 to 0.910 g/cm3 and (a2) a melt flow rate (MFR2) (ASTM D1238, a load of 2.16 kg, 190° C.) is in the range of 0.1 to 40 g/10 minutes at a load of 2.16 kg and at 190° C.; and the component (B) satisfying the conditions in which (b1) a ratio (Et/α) of a content (Et, mole %) of constitutional units derived from ethylene and a content (α, mole %) of constitutional units derived from propylene is in the range of 50/50 to 80/20, (b2) an iodine value is in the range of 0.5 to 50 (g/100 g), and (b3) a Mooney viscosity (ML1+4 (100° C.)) (JIS K6395) is in the range of 1 to 100.