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US 12,734,740 B2Granted
Biaxially oriented film
AssigneeNOVA Chemicals (International) S.A.
InventorsMaryam Fereydoon, Shivendra Goyal, Sepideh Kasiri, Owen Lightbody, Norman Aubee, Bronwyn Gillon, Christian Carello
Life of this patent
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Abstract
A biaxially oriented polyethylene film structure comprises at least three layers, at least one layer comprising a polyethylene composition, the polyethylene composition having a density of from 0.941 to 0.962 g/cm3; a melt index, I2 of from 0.5 to 5.0 g/10 min; and a molecular weight distribution Mw/Mn, of from 3.0 to 8.0. The biaxially oriented film has good optical properties.
Claims41
A biaxially oriented polyethylene film structure comprising at least three layers, wherein three adjacent layers each comprise a polyethylene composition, the polyethylene composition comprising:
- (i) from 15 to 50 weight % of first ethylene copolymer;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- and
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- and a melt index, I2 of from 0.5 to 5.0 g/10min.
5 more elements
A biaxially oriented polyethylene film structure comprising at least three layers, wherein three adjacent layers each comprise:
- A) at least 75 weight percent of a polyethylene composition;
- and
- B) 25 weight percent or less of a polymer selected from the group consisting of LLDPE, VLDPE, MDPE, HDPE and mixtures thereof;
- wherein the polyethylene composition comprises:
- (i) from 15 to 50 weight % of first ethylene copolymer;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- and
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- and a melt index, I2 of from 0.5 to 5.0 g/10 min.
9 more elements
A biaxially oriented polyethylene film structure comprising:
- a core layer;
- a first skin layer adjacent to a first side of the core layer;
- and
- a second skin layer adjacent to a second side of the core layer;
- wherein each of the core layer, the first skin layer, and the second skin layer comprise a polyethylene composition;
- the polyethylene composition comprising:
- (i) from 15 to 50 weight % of first ethylene copolymer;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- and
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- and a melt index, I2 of from 0.5 to 5.0 g/10 min.
11 more elements
A process to prepare a biaxially oriented polyethylene film structure, the process comprising:
- (a) coextruding a polyethylene composition into a base film structure comprising at least three adjacent layers;
- (b) stretching the base film structure to a stretch ratio of from 3:1 to 10:1 in the machine direction;
- and
- (c) stretching the base film structure to a stretch ratio of from 3:1 to 12:1 in the transverse direction;
- wherein (a) and (b) are carried out in any order or are performed simultaneously;
- and
- wherein the polyethylene composition comprises:
- (i) from 15 to 50 weight % of first ethylene copolymer;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- and
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- and a melt index, I2 of from 0.5 to 5.0 g/10 min.
12 more elements
A process to prepare a biaxially oriented polyethylene film structure, the process comprising:
- (a) coextruding a polymer blend comprising at least 75 weight percent of a polyethylene composition into a base film structure comprising at least three adjacent layers;
- (b) stretching the base film structure to a stretch ratio of from 3:1 to 10:1 in the machine direction;
- and
- (c) stretching the base film structure to a stretch ratio of from 3:1 to 12:1 in the transverse direction;
- wherein (b) and (c) are carried out in any order or are performed simultaneously;
- and
- wherein the polyethylene composition comprises:
- (i) from 15 to 50 weight % of first ethylene copolymer;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- and a melt index, I2 of from 0.5 to 5.0 g/10 min;
- and
- wherein the balance of the polymer blend by weight is a polymer selected from the group consisting of LLDPE, VLDPE, MDPE, HDPE and mixtures thereof.
13 more elements
A biaxially oriented polyethylene film structure comprising at least three layers, wherein each layer comprises a polyethylene composition, the polyethylene composition comprising:
- from 15 to 50 weight % of first ethylene copolymer having a weight average molecular weight, Mw of from 170,000 g/mol to 470,000 g/mol;
- and
- 11 from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- a melt index, I2 of from 0.5 to 5.0 g/10 min;
- a melt flow ratio, I21/I2 of ≥35;
- a Z-average molecular weight distribution, Mz/Mw of ≥ 2.5;
- a comonomer distribution breadth index, CDBI50 of >50 wt %;
- a long chain branching factor, LCBF of >0.0010;
- and
- wherein in a temperature rising elution fractionation (CTREF) analysis, the polyethylene composition has greater than 70 weight percent of material eluting at a temperature of greater than 90° C.
10 more elements
A biaxially oriented polyethylene film structure comprising at least three layers, wherein three adjacent layers each comprise a polyethylene composition, the polyethylene composition comprising:
- (i) from 15 to 50 weight % of first ethylene copolymer having a weight average molecular weight, Mw of from 170,000 g/mol to 470,000 g/mol;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- a melt index, I2 of from 0.5 to 5.0 g/10 min;
- a melt flow ratio, I21/I2 of ≥35;
- a Z-average molecular weight distribution, Mz/Mw of ≥2.5;
- a comonomer distribution breadth index, CDBI50 of >50 wt %;
- a long chain branching factor, LCBF of >0.0010;
- and
- wherein in a temperature rising elution fractionation (CTREF) analysis, the polyethylene composition has greater than 70 weight percent of material eluting at a temperature of greater than 90° C.
10 more elements
A biaxially oriented polyethylene film structure comprising:
- a core layer;
- a first skin layer adjacent to a first side of the core layer;
- and
- a second skin layer adjacent to a second side of the core layer;
- wherein each of the core layer, the first skin layer, and the second skin layer comprise a polyethylene composition;
- the polyethylene composition comprising:
- (i) from 15 to 50 weight % of first ethylene copolymer having a weight average molecular weight, Mw of from 170,000 g/mol to 470,000 g/mol;
- and
- (ii) from 85 to 50 weight % of a second ethylene copolymer;
- wherein the first ethylene copolymer has a higher weight average molecular weight, Mw than the second ethylene copolymer;
- wherein the ratio (SCB1/SCB2) of the number of short chain branches per thousand carbon atoms in said first ethylene copolymer (SCB1) to the number of short chain branches per thousand carbon atoms in said second ethylene copolymer (SCB2) is from 0.8 to 3.5;
- wherein the polyethylene composition has a density of from 0.941 to 0.962 g/cm3;
- a melt index, I2 of from 0.5 to 5.0 g/10 min;
- a melt flow ratio, I21/I2 of ≥35;
- a Z-average molecular weight distribution, Mz/Mw of ≥2.5;
- a comonomer distribution breadth index, CDBI50 of >50 wt %;
- a long chain branching factor, LCBF of >0.0010;
- and
- wherein in a temperature rising elution fractionation (CTREF) analysis, the polyethylene composition has greater than 70 weight percent of material eluting at a temperature of greater than 90° C.
16 more elements
Dependencies are inferred from the claim text.