Patent ID: 8889793

Claim:
A multimodal polyethylene copolymer resin composition consisting of a lower molecular weight (LMW) ethylene polymer fraction (a) having a weight average molecular weight (Mw) of from 50,000 to 100,000 grams per mole and a higher molecular weight (HMW) ethylene copolymer fraction (b) having a higher Mw than the LMW fraction (a), wherein the higher molecular weight (HMW) ethylene copolymer fraction (b) comprises a higher molecular weight (HMW) ethylene copolymer subfraction (b1) and a very high molecular weight (VHMW) ethylene copolymer subfraction (b2), wherein the HMW ethylene copolymer subfraction (b1) consists of ethylene copolymers having a weight average molecular weight between 500,000 and 1,000,000 grams per mole and at least 2 times the weight average molecular weight (Mw) of said multimodal polyethylene copolymer resin composition, which HMW ethylene copolymer subfraction (b1) amounts from 1-30 wt % of the total amount of the multimodal polyethylene copolymer resin composition and comprises a comonomers content of between 3-25 wt % of the total amount of comonomer content used in said multimodal polyethylene copolymer resin composition; wherein the very high molecular weight (VHMW) ethylene copolymer subfraction (b2) consists of ethylene copolymers having a weight average molecular weight greater than 1,000,000 grams per mole and at least 3 times of the weight average molecular weight (Mw) of said multimodal polyethylene copolymer resin composition, which VHMW ethylene copolymer subfraction (b2) amounts of from 0.5-15 wt % of said multimodal polyethylene copolymer resin composition and has a comonomer content of 3-20 wt % of the total amount of comonomer content used in said multimodal polyethylene copolymer resin composition; wherein 1-hexene is used as the comonomer and the total amount of comonomer used in said polyethylene copolymer resin composition is from 6.5 wt % to 10 wt %.