Propylene ethylene polymers
AssigneeExxonMobile Chemical Patents Inc.
InventorsCharles Cozewith, Sudhin Datta, Weiguo Hu
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Abstract
Ethylene propylene copolymers, substantially free of diene, are described. The copolymers will have a uniform distribution of both tacticity and comonomer between copolymer chains. Further, the copolymers will exhibit a statistically insignificant intramolecular difference of tacticity. The copolymers are made in the presence of a metallocene catalyst.
Claims61
A copolymer comprising 5 to 25% by weight of ethylene-derived units and 95 to 75% by weight of propylene-derived units, the copolymer having:
- (a) a melting point of less than 90° C.;
- (b) a relationship of elasticity to 500% tensile modulus such that
- Elasticity≦0.935M+12,
- where elasticity is in percent and M is the 500% tensile modulus in MPa;
- and
- (c) a relationship of flexural modulus to 500% tensile modulus such that
- Flexural Modulus≦4.2e0.27M+50,
- where flexural modulus is in MPa and M is the 500% tensile modulus in MPa.
A copolymer prepared by Metallocene-catalyzed polymerization comprising 5 to 25% by weight of ethylene-derived units and 95 to 75% by weight of propylene-derived units and substantially free of diene-derived units, the copolymer having:
- (a) a melting point of less than 90° C.;
- (b) a relationship of elasticity to 500% tensile modulus such that
- Elasticity≦0.935M+12,
- where elasticity is in percent and is less than 30% and M is the 500% tensile modulus in MPa;
- (c) a relationship of flexural modulus to 500% tensile modulus such that
- Flexural Modulus≦4.2e,0.27M+50,
- where flexural modulus is in MPa and M is the 500% tensile modulus in MPa;
- (d) a heat of fusion of from 1.0 J/g to 40 J/g;
- and
- (e) a molecular weight distribution Mw/Mn of 1.5-5.
Dependencies are inferred from the claim text.