Bimodal polyethylene copolymer and film thereof
AssigneeDow Global Technologies LLC
InventorsBo Liu, John F. Szul, Chuan C. He, Roger L. Kuhlman, Timothy R. Lynn
Life of this patent
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Abstract
A bimodal copolymer comprises on average at least 90 weight-percent units derived from ethylene and at least 0.05 weight percent units derived from an α-olefin comonomer having from 4 to 10 carbon atoms, wherein the copolymer has the properties described herein.
Claims15
A bimodal copolymer comprising on average at least 90 weight-percent units derived from ethylene monomer and at least 0.05 weight percent units derived from an α-olefin comonomer having from 4 to 10 carbon atoms, based on total weight of the bimodal copolymer, wherein:
- (a) the bimodal copolymer comprises at least 45 weight percent of a higher molecular weight fraction having a weight-average molecular weight (Mw) of at least 400,000, measured by “a gel permeation chromatography (GPC) test method described in the description;
- and
- (b) the bimodal copolymer comprises at least 35 weight percent of a lower molecular weight fraction having a weight-average molecular weight (Mw) of at most 50,000, measured by the GPC test method;
- and
- (c) the weight average molecular weight (Mw) of the higher molecular weight fraction is 30 to 50 times the weight average molecular weight (Mw) of the lower molecular weight fraction;
- and
- (d) the bimodal copolymer has an overall melt flow ratio (I21/I2) of at least 90, measured according to ASTM D1238-13(190° C., 21.6 kg or 2.16 kg);
- and
- (e) the bimodal copolymer has an overall z-average molecular weight/weight-average molecular weight (Mz/Mw) ratio of at least 8, measured by the GPC test method;
- and
- (f) an oligomer content of the bimodal copolymer is no more than 1000 parts per million by weight (ppm), based on 1,000,000 weight parts of the bimodal copolymer, measured using the gas chromatography test method;
- and
- (g) the bimodal copolymer further comprises at least 20 ppb of a dimethyl-1H-indenyl compound.
A bimodal copolymer comprising on average at least 90 weight-percent units derived from ethylene monomer and 1 to 5 weight percent units of repeating units in the bimodal copolymer are derived from 1-hexene, based on total weight of the bimodal copolymer, wherein:
- (a) the bimodal copolymer comprises at least 45 weight percent of a higher molecular weight fraction having a weight-average molecular weight (Mw) of at least 400,000, measured by “a gel permeation chromatography (GPC) test method described in the description;
- and
- (b) the bimodal copolymer comprises at least 35 weight percent of a lower molecular weight fraction having a weight-average molecular weight (Mw) of at most 50,000, measured by the GPC test method;
- and
- (c) the weight average molecular weight (Mw) of the higher molecular weight fraction is 30 to 50 times the weight average molecular weight (Mw) of the lower molecular weight fraction;
- and
- (d) the bimodal copolymer has an overall melt flow ratio (b I21/I2) of at least 90, measured according to ASTM D1238-13 (190° C., 21.6 kg or 2.16 kg);
- and
- (e) the bimodal copolymer has an overall z-average molecular weight/weight-average molecular weight (Mz/Mw) ratio of at least 8, measured by the GPC test method;
- and
- (f) an oligomer content of the bimodal copolymer is no more than 1000 parts per million by weight (ppm), based on 1,000,000 weight parts of the bimodal copolymer, measured using the gas chromatography test method.
Dependencies are inferred from the claim text.