Crosslinked product, method for producing the same and the use thereof, and ethylene copolymer
The present method for producing a crosslinked product include the steps of: melt molding an ethylene copolymer (A) or a resin composition containing the ethylene copolymer (A); and carrying out crosslinking; wherein the ethylene copolymer (A) contains a constitutional unit derived from ethylene and a constitutional unit derived from an α-olefin having 3 to 20 carbon atoms, and satisfies the following requirements (1), (2) and (3): (1) a vinyl group content per 1,000 carbon atoms as measured by 1 H-NMR is from 0.06 to 1; (2) a ratio MFR 10 /MFR 2.16 is from 8.5 to 50; and (3) a density d is from 850 kg/m 3 to 920 kg/m 3 . The present method for producing a crosslinked product is capable of providing a crosslinked product having a good moldability and an excellent mechanical strength. Further, the present method is capable of providing a foamed product which is light weight and excellent in mechanical strength, with an excellent productivity; as well as providing crosslinked molded articles whose dimensional variations between individual products are small.
1. A method for producing a crosslinked product, comprising the steps of:
melt molding an ethylene copolymer (A) or a resin composition containing the ethylene copolymer (A); and
carrying out crosslinking;
wherein the ethylene copolymer (A) contains a constitutional unit derived from ethylene and a constitutional unit derived from an α-olefin having from 3 to 20 carbon atoms, and satisfies all of the following requirements (1), (2) and (3):
(1) a vinyl group content per 1,000 carbon atoms as measured by 1 H-NMR is 0.09 or more and one or less;
(2) a ratio MFR 10 /MFR 2.16 is 8.6 or more and 50 or less; and
(3) a density d is 850 kg/m 3 or more and 920 kg/m 3 or less
(wherein, MFR 10 represents a melt flow rate (g/10 min) as measured in accordance with ASTM D1238 at a load of 10 kg and at a temperature of 190° C.; and MFR 2.16 represents a melt flow rate (g/10 min) as measured in accordance with ASTM D1238 at a load of 2.16 kg and at a temperature of 190° C.).
2. The method for producing a crosslinked product according to claim 1 , wherein the ethylene copolymer (A) further satisfies the following requirement (4):
(4) MFR 2.16 is within the range of from 0.01 to 200 g/10 min.
3. The method for producing a crosslinked product according to claim 1 or 2 , wherein the ethylene copolymer (A) is an ethylene copolymer (A1) comprising ethylene-derived structural units and α-olefin-derived structural units alone as structural units.
4. The method for producing a crosslinked product according to claim 1 , further comprising the step of carrying out foaming.
5. The method for producing a crosslinked product according to claim 1 , wherein the step of melt molding is carried out by injection molding or transfer molding, and wherein the method further comprises the step of carrying out foaming.
6. A laminated molded article comprising a layer composed of one or more kinds of raw materials selected from the group consisting of polyolefin, polyurethane, rubber, leather and artificial leather, and the crosslinked product according to claim 1 , wherein the layer composed of one or more kinds of raw materials and the crosslinked product are laminated together.
7. The laminated molded article according to claim 6 , wherein the laminated molded article is a footwear part.
8. The laminated molded article according to claim 7 , wherein the footwear part is a midsole, an inner sole, or a sole.
9. An ethylene copolymer (A) which contains a constitutional unit derived from ethylene and a constitutional unit derived from an α-olefin having from 3 to 20 carbon atoms, and which satisfies all of the following requirements (1), (2) and (3):
(1) a vinyl group content per 1,000 carbon atoms as measured by 1 H-NMR is 0.09 or more and one or less;
(2) a ratio MFR 10 /MFR 2.16 is 8.6 or more and 50 or less; and
(3) a density d is 850 kg/m 3 or more and 920 kg/m 3 or less
(wherein, MFR 10 represents a melt flow rate (g/10 min) as measured in accordance with ASTM D1238 at a load of 10 kg and at a temperature of 190° C.; and MFR 2.16 represents a melt flow rate (g/10 min) as measured in accordance with ASTM D1238 at a load of 2.16 kg and at a temperature of 190° C.).
10. The ethylene copolymer (A) according to claim 9 , wherein the ethylene copolymer (A) further satisfies the following requirement (4):
(4) MFR 2.16 is within the range of from 0.01 to 200 g/10 min.
11. The ethylene copolymer (A) according to claim 9 or 10 , wherein the ethylene copolymer (A) is an ethylene copolymer (A1) comprising ethylene-derived structural units and α-olefin-derived structural units alone as structural units.
12. An ethylene copolymer composition comprising the ethylene copolymer (A) according to claim 9 and a crosslinking agent (C).
13. The ethylene copolymer composition according to claim 12 , further comprising a foaming agent (D).