Shaped polyethylene articles of intermediate molecular weight and high modulus
First Claim
1. A film or fiber consisting essentially of polyethylene having a weight average molecular weight between about 200,000 and less than 800,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/denier, a crystalline orientation function of at least 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and a traverse microfibrillar spacing of less than 150 Å
.
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Accused Products
Abstract
Solutions of intermediate molecular weight polymers from about 200,000 to about 4,000,000, such as polyethylene, in a relatively non-volatile solvent are extruded through an aperature at constant concentration and thereafter stretched at a ratio of at least about 3:1 prior to cooling to form a first gel. The first gels are extracted with a volatile solvent to form a second gel, and the second gel is dried to form a low porosity xerogel. Stretching occurs with any one or more of the first gel, second gel or xerogel. The polyethylene products produced by our process include products having a molecular weight between about 200,000 and about 4,000,000 a tenacity of at least about 13 grams/denier, a modulus of at least about 350 gram/denier, a porosity of less than 10% by volume, a crystalline orientation function of at least about 0.95, and a main melting temperature of at least about 140° C.
80 Citations
13 Claims
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1. A film or fiber consisting essentially of polyethylene having a weight average molecular weight between about 200,000 and less than 800,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/denier, a crystalline orientation function of at least 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and a traverse microfibrillar spacing of less than 150 Å
. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- C. (measured at 10°
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9. A film or fiber consisting essentially of polyethylene having a weight average molecular weight between 200,000 and 800,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/denier, a crystalline orientation function of at least 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and said fiber or film having been produced by a solution spinning process in which a solution of the polyethylene is subjected to stretching at a ratio of at least 3;
1.
- C. (measured at 10°
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10. Yarn comprising polyethylene fiber having a weight average molecular weight between 200,000 and 800,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/-denier, a crystalline orientation function of at least 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and a traverse microfibrillar spacing of less than 150 Å
.
- C. (measured at 10°
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11. A film or fiber consisting essentially of polyethylene having a weight average molecular weight between 200,000 and 500,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/denier, a crystalline orientation function of at least about 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and said fiber or film having been produced by a solution spinning process in which a solution of the polyethylene is subjected to stretching at a ratio of at least 3;
1.
- C. (measured at 10°
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12. A film or fiber consisting essentially of polyethylene having a weight average molecular weight between 200,000 and 4,000,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/denier, a crystalline orientation function of at least 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and a traverse microfibrillar spacing of less than 150 Å
.
- C. (measured at 10°
-
13. A film or fiber consisting essentially of polyethylene having a weight average molecular weight between 200,000 and less than 4,000,000 kg/kg mole, said fiber or film having a tensile modulus of at least 350 grams/denier, a tenacity of at least 13 grams/denier, a crystalline orientation function of at least 0.95, a main melting temperature of at least 140°
- C. (measured at 10°
C./minute heating rate by differential scanning calorimetry), an ultimate elongation of not more than 5%, and said fiber or film having been produced by a solution spinning process in which a solution of the polyethylene is subjected to stretching at a ratio of at least 3;
1.
- C. (measured at 10°
Specification