Molecularly oriented molded body of ultra-high-molecular-weight ethylene/alpha-olefin copolymer

Claim 2

A molecularly oriented molded body of an ultra-high-molecular weight ethylene/α-olefin copolymer having an intrinsic viscosity (η) of at least 5dl/g and such a content of an α-olefin having at least 3 carbon atoms that the number of molecules of the α-olefin is 0.1 to 15 on the average per 1000 carbon atoms, wherein the molded body shows at least two crystal fusion endothermic peaks when the measurement is conducted in the restraint state by using a differential scanning calorimeter, the molded body has at least one crystal fusion endothermic peak (Tp) at a temperature higher by at least 20°C than the inherent crystal fusion temperature (Tm) of the ultra-high--­molecular-weight ethylene/α-olefin copolymer determined as the main fusion endothermic peak at the time of the second elevation of the temperature, and the quantity of heat based on crystal fusion endothermic peak (Tp) is at least 15% based on the total fusion heat quality.

Claim 3

A molded body according to claim 1, wherein the α-olefin is butene-1 or propylene or an α-olefin having at least 5 carbon atoms.

Claim 4

A molded body according to claim 1, wherein the copolymer comprises a mixture of a first α-olefin selected from propylene and butene-1 and a second α-olefin different from the first/α-olefin and selected from α-olefins having at least 4 carbon atoms.

Claim 5

A molded body according to any one of claims 1 to 3 wherein the α-olefin content is 0.5 to 10 -olefin molecules per 1000 carbon atoms.

Claim 6

A molded body according to any one of claims 1 to 4 wherein the heat quantity based on the crystal fusion endothermic peak (Tp) is at least 30% based on the total fusion heat quantity.

Claim 7

A molded body according to any one of claims 1 to 5 which is in the form of a filament.

Claim 8

A molded body according to claim 6 which is obtained by melt-kneading a composition comprising the ultra-high-molecular-weight ethylene/α-olefin copolymer and a diluent, extruding the melt in the form of a filament and drawing the obtained filament.

Claim 9

A molecularly oriented and drawn filament according to any one of claims 1 to 7 having an elastic modulus of at least 20 GPa and a tensile strength of at least 1.2 GPa, the elastic modulus retention ratio is at least 90% and the tensile straight retention ratio is at least 90% after heating at 170°C for 5 mins.

Claim 10

A drawn filament according to any one of claims 6 to 8 which has an orientation degree (F) of at least 0.90.

Claim 11

A molecularly oriented and drawn filament according to any one of claims 1 to 9 comprising an ultra-high-molecular-weight ethylene/α-olefin copolymer having an intrinsic viscosity (η) of at least 5 dℓ/g and such a content of an α-olefin having at least 5 carbon atoms that the number of molecules of the α-olefin is 0.1 to 15 on the average per 1000 carbon atoms, wherein the filament shows at least two crystal fusion endothermic peaks when the measurement is conducted in the restraint state by using a differential scanning calorimeter, the filament has at least two crystal fusion endothermic peaks (Tp) at a temperature higher by at least 20°C than the inherent crystal fusion temperature (Tm) of the ultra-high-molecular-weight ethylene/α-olefin copolymer determined as the main fusion endothermic peak at the time of the second elevation of the temperature, the crystal fusion endothermic peaks (Tp) comprise a high-temperature fusion peak (Tp1) in a temperature range of from Tm + 35°C to Tm + 100°C and a low-temperature fusion peak (Tp2) in a temperature range of from Tm + 20°C to Tm + 35°C the heat quantity based on the crystal fusion endothermic peaks (Tp) is at least 30% based on the total fusion heat quantity, the heat quantity based on the high-temperature fusion peak (Tp1) is at least 3% based on the total fusion heat quantity, the filament has an elastic modulus of at least 30 GPa and a tensile strength of at least 1.5 GPa, after a heat history at 170°C for 5 minutes, the filament has a strength retention ratio of at least 95% and an elastic modulus retention ratio of at least 95%, and the creep (CR₉₀) determined as the elongation after the filament has been

Claim 12

A drawn filament according to claim 10 wherein the α-olefins is 4-methylpentene-1, hexene-1 or octene-1.

Claim 13

A drawn filament according to claim 10 or claim 11 having a rupture time (T, hours) under a load (F, MPa) of 750 to 1500 Mpa at room temperature which satisfies the following requirement:

Claim 14

A drawn filament according to claim 8 wherein the α-olefin is butene-1 and having a rupture time (T, hours) under a load (F, MPa) of 750 to 1500 MPa at room temperature, which satisfies the following requirement: