Polyethylene homopolymer compositions with good barrier properties

文档序号：74382 发布日期：2021-10-01 浏览：48次中文

阅读说明：本技术 具有良好的阻隔性质的聚乙烯均聚物组合物 (Polyethylene homopolymer compositions with good barrier properties ) 是由 X·王于 2019-11-28 设计创作，主要内容包括：聚乙烯均聚物组合物包含：具有0.943至0.975 g/cm～(3)的密度d～(1)、0.01至10 g/10min的熔体指数I-2～(1)和小于3.0的分子量分布M-w/M-n的第一乙烯均聚物；和具有0.950至0.985 g/cm～(3)的密度d～(2)、至少500 g/10min的熔体指数I-2～(2)和小于3.0的分子量分布M-w/M-n的第二乙烯均聚物；其中第二乙烯均聚物的熔体指数I-2～(2)对第一乙烯均聚物的熔体指数I-2～(1)的比为至少50。可成核的聚乙烯均聚物组合物具有≤75,000的重均分子量M-w、至少200 g/10min的高负荷熔体指数I-(21)和4.0至12.0的分子量分布M-w/M-n,并可用于模塑应用,如例如用于压塑密封件。(The polyethylene homopolymer composition comprises: has a density of 0.943 to 0.975g/cm 3 Density d of 1 Melt index I of 0.01 to 10 g/10min 2 1 And a molecular weight distribution M of less than 3.0 w /M n A first ethylene homopolymer of (a); and has a density of 0.950 to 0.985 g/cm 3 Density d of 2 A melt index I of at least 500g/10min 2 2 And a molecular weight distribution M of less than 3.0 w /M n A second ethylene homopolymer of (a); wherein the second ethylene homopolymer has a melt index I 2 2 To the first ethyleneMelt index I of the homopolymer 2 1 Is at least 50. The nucleated polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less w A high load melt index I of at least 200g/10 min 21 And a molecular weight distribution M of 4.0 to 12.0 w /M n And may be used in molding applications such as, for example, for compression molding seals.)

1. A polyethylene homopolymer composition comprising:

(1) 10 to 90% by weight of a binder having a viscosity of 0.943 to 0.975g/cm³Density d of¹Melt index I of 0.01 to 10 g/10min₂ ¹And a molecular weight distribution M of less than 3.0_w/M_nA first ethylene homopolymer of (a); and

(2) 90 to 10% by weight of a binder having a viscosity of 0.950 to 0.985 g/cm³Density d of²A melt index I of at least 500g/10min₂ ²And a molecular weight distribution M of less than 3.0_w/M_nA second ethylene homopolymer of (a);

wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50, and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index of at least 200g/10 min and a molecular weight distribution M of from 4.0 to 12.0_w/M_n。

2. According to claim1, wherein the second ethylene homopolymer has a melt index, I₂ ²Melt index I for said first ethylene homopolymer₂ ¹Is at least 100.

3. The polyethylene homopolymer composition of claim 1, wherein the second ethylene homopolymer has a melt index, I₂ ²Melt index I for said first ethylene homopolymer₂ ¹Is at least 1000.

4. The polyethylene homopolymer composition of claim 1, wherein the second ethylene homopolymer has a melt index, I₂ ²Melt index I for said first ethylene homopolymer₂ ¹Is at least 5000.

5. The polyethylene homopolymer composition of claim 1, wherein the second ethylene homopolymer has a density d²A density d higher than that of the first ethylene homopolymer¹。

6. The polyethylene homopolymer composition of claim 5, wherein the second ethylene homopolymer has a density d²Density d of said first ethylene homopolymer¹Less than 0.035 g/cm³。

7. The polyethylene homopolymer composition of claim 5, wherein the second ethylene homopolymer has a density d²Density d of said first ethylene homopolymer¹Less than 0.030 g/cm³。

8. The polyethylene homopolymer composition of claim 1, wherein the first ethylene homopolymer has from 0.946 to 0.965 g/cm³Density d of¹。

9. The polyethylene homopolymer composition of claim 1, which isThe second ethylene homopolymer of (1) has a density of 0.955 to 0.980 g/cm³Density d of²。

10. The polyethylene homopolymer composition of claim 1, wherein the first and the second ethylene homopolymers each have a molecular weight distribution, M, of less than 2.5_w/M_n。

11. The polyethylene homopolymer composition of claim 1, wherein said first and second ethylene homopolymers are made with a single site catalyst.

12. The polyethylene homopolymer composition of claim 1, wherein the polyethylene homopolymer composition has from 0.950 to 0.980 g/cm³The density of (c).

13. The polyethylene homopolymer composition of claim 1, wherein the polyethylene homopolymer composition has from 0.961 to 0.975g/cm³The density of (c).

14. The polyethylene homopolymer composition of claim 1, wherein the polyethylene homopolymer composition has a high load melt index I, greater than 300₂₁。

15. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene homopolymer composition has a melt index I ≥ 3g/10min₂。

16. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene homopolymer composition has a melt index I of from 5 to 40 g/10min₂。

17. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene homopolymer composition has a molecular weight distribution M from 4.0 to 10.0_w/M_n。

18. The polyethylene homopolymer composition of claim 1, wherein the polyethylene homopolymer composition has a bimodal profile in a GPC chromatogram.

19. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene composition has a weight average molecular weight, M, of less than 70,000_w。

20. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene homopolymer composition has a weight average molecular weight M of 65,000 or less_w。

21. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene homopolymer composition has a number average molecular weight M of less than 20,000_n。

22. The polyethylene homopolymer composition according to claim 1, wherein the polyethylene homopolymer composition has a melt flow ratio I, of less than 45₂₁/I₂。

23. The polyethylene homopolymer composition of claim 1, wherein the polyethylene homopolymer composition has a hexane extractables value of less than 2 wt.%.

24. The polyethylene homopolymer composition of claim 1, wherein the polyethylene homopolymer composition further comprises a nucleating agent.

25. The polyethylene homopolymer composition of claim 25, wherein the nucleating agent is a salt of a dicarboxylic acid compound.

26. The polyethylene homopolymer composition of claim 26, wherein the polyethylene homopolymer composition comprises 20 to 4000 ppm of a nucleating agent, based on the combined weight of the first ethylene homopolymer and the second ethylene homopolymer.

27. An injection molded article comprising the polyethylene homopolymer composition of claim 1,2, 3, 4, 5,6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26.

28. A compression molded article comprising the polyethylene homopolymer composition of claim 1,2, 3, 4, 5,6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26.

29. A seal comprising the polyethylene homopolymer composition of claim 1,2, 3, 4, 5,6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26.

30. A film comprising the polyethylene homopolymer composition of claim 1,2, 3, 4, 5,6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26.

31. A cast film comprising the polyethylene homopolymer composition of claim 1,2, 3, 4, 5,6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26.

32. A polyethylene homopolymer composition comprising:

Wherein the polyethylene homopolymer composition is prepared by a process comprising contacting at least one single-site polymerization catalyst system with ethylene in at least two polymerization reactors under solution polymerization conditions.

33. A process for preparing a polyethylene homopolymer composition comprising:

wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50, and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index I of at least 200g/10 min₂₁And a molecular weight distribution M of 4.0 to 12.0_w/M_n；

The process comprises contacting at least one single-site polymerization catalyst system with ethylene under solution polymerization conditions in at least two polymerization reactors.

34. The method of claim 33, wherein the at least two polymerization reactors comprise a first reactor and a second reactor configured in series.

35. A polymer composition comprising from 1 to 100 wt% of a polyethylene homopolymer composition comprising:

wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50, and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index I of at least 200g/10 min₂₁And a molecular weight distribution M of 4.0 to 12.0_w/M_n。

36. The polymer composition of claim 35, wherein the polyethylene homopolymer composition further comprises a nucleating agent.

37. The polymer composition of claim 36, wherein the nucleating agent is a salt of a dicarboxylic acid compound.

38. The polymer composition of claim 37, wherein the polyethylene homopolymer composition comprises 20 to 4000 ppm of a nucleating agent, based on the combined weight of the first ethylene homopolymer and the second ethylene homopolymer.

39. The polyethylene homopolymer composition of claim 24, having less than 0 when made into a PCO 1881 CSD seal.0025 cm³Seal/day OTR.

40. Comprising the polyethylene homopolymer composition of claim 24 and having a thickness of 80cm or less³/100 in²Film of normalized OTR/day.

41. Comprising the polyethylene homopolymer composition of claim 24 and having a viscosity of 0.250 g/100 in²Films of normalized WVTR per day.

Technical Field

The present disclosure describes polyethylene homopolymer compositions that provide good barrier properties when used in, for example, films or seals. The nucleated polyethylene homopolymer composition comprises a first ethylene homopolymer component and a second ethylene homopolymer component, each made with a single site polymerization catalyst to have different melt indices, I₂. The polyethylene homopolymer composition has a relatively low weight average molecular weight.

Background of the field

Much work has been done to develop polyethylene compositions comprising both ethylene copolymers and ethylene homopolymers (or ethylene copolymers with less short chain branching). When the ethylene copolymer component has a higher molecular weight than the ethylene homopolymer component (or ethylene copolymer with fewer short chain branches), the resulting polyethylene composition is useful in end-use applications where a high degree of environmental resistance is desired (see, e.g., U.S. patent No. 6,809,154). Such end-use applications include, for example, molded articles such as all-polyethylene seals for bottles (see, e.g., WO 2016/135590, and U.S. Pat. Nos. 9,758,653; 9,074,082; 9,475,927; 9,783,663; 9,783,664; 8,962,755; 9,221,966; 9,371,442 and 8,022,143). Work has also been conducted to develop polyethylene compositions comprising two ethylene homopolymer components, wherein the selected components have relatively low and relatively high molecular weights. These ethylene homopolymer compositions, which may have bimodal molecular weight distribution curves, have been effectively applied to form films with good barrier properties (see, e.g., U.S. patent nos. 7,737,220 and 9,587,093, and U.S. patent application publication nos. 2008/0118749, 2009/0029182, and 2011/0143155).

Summary of The Invention

We now report a novel ethylene homopolymer composition comprising a first ethylene homopolymer component and a second ethylene homopolymer component. The novel ethylene homopolymer compositions, which can be nucleated, can be effectively used as such in various end-use applications. Alternatively, the novel ethylene homopolymer compositions may be used as a polymer blend component in a polymer composition.

One embodiment of the present disclosure is a polyethylene homopolymer composition comprising: (1) 10 to 90% by weight of a binder having a viscosity of 0.943 to 0.975g/cm³Density d of¹Melt index I of 0.01 to 10 g/10min₂ ¹And a molecular weight distribution M of less than 3.0_w/M_nA first ethylene homopolymer of (a); and (2) 90 to 10% by weight of a binder having a viscosity of 0.950 to 0.985 g/cm³Density d of²A melt index I of at least 500g/10min₂ ²And a molecular weight distribution M of less than 3.0_w/M_nA second ethylene homopolymer of (a); wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50, and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index I of at least 200g/10 min₂₁And a molecular weight distribution M of 4.0 to 12.0_w/M_n。

In one embodiment of the present disclosure, the polyethylene homopolymer composition further comprises a nucleating agent, or a mixture of nucleating agents.

In one embodiment of the present disclosure, the polyethylene homopolymer composition comprises a nucleating agent which is a salt of a dicarboxylic acid compound.

In one embodiment of the present disclosure, the polyethylene homopolymer composition comprises from 20 to 4000 ppm of a nucleating agent or mixture of nucleating agents.

One embodiment of the present disclosure is an injection molded article comprising a polyethylene homopolymer composition.

One embodiment of the present disclosure is a compression molded article comprising the polyethylene homopolymer composition.

One embodiment of the present disclosure is a seal (e.g., a seal for a bottle) comprising a polyethylene homopolymer composition.

One embodiment of the present disclosure is a film comprising a polyethylene homopolymer composition.

One embodiment of the present disclosure is a polyethylene homopolymer composition comprising: (1) 10 to 90% by weight of a binder having a viscosity of 0.943 to 0.975g/cm³Density d of¹Melt index I of 0.01 to 10 g/10min₂ ¹And a molecular weight distribution M of less than 3.0_w/M_nA first ethylene homopolymer of (a); and (2) 90 to 10% by weight of a binder having a viscosity of 0.950 to 0.985 g/cm³Density d of²A melt index I of at least 500g/10min₂ ²And a molecular weight distribution M of less than 3.0_w/M_nA second ethylene homopolymer of (a); wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50 and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index I of at least 200g/10 min₂₁And a molecular weight distribution M of 4.0 to 12.0_w/M_n(ii) a And wherein the polyethylene homopolymer composition is prepared by a process comprising contacting at least one single-site polymerization catalyst system with ethylene in at least two polymerization reactors under solution polymerization conditions.

One embodiment of the present disclosure is a method of making a polyethylene homopolymer composition comprising: (1) 10 to 90% by weight of a binder having a viscosity of 0.943 to 0.975g/cm³Density d of¹Melt index I of 0.01 to 10 g/10min₂ ¹And a molecular weight distribution M of less than 3.0_w/M_nA first ethylene homopolymer of (a); and (2) 90 to 10% by weight of a binder having a viscosity of 0.950 to 0.985 g/cm³Density d of²A melt index I of at least 500g/10min₂ ²And a molecular weight distribution M of less than 3.0_w/M_nA second ethylene homopolymer of (a); wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50, and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index I of at least 200g/10 min₂₁And a molecular weight distribution M of 4.0 to 12.0_w/M_n(ii) a The process comprises contacting at least one single-site polymerization catalyst system with ethylene under solution polymerization conditions in at least two polymerization reactors.

In one embodiment of the present disclosure, the at least two polymerization reactors comprise a first reactor and a second reactor configured in series.

One embodiment of the present disclosure is a polymer composition comprising 1 to 100 wt% of a polyethylene homopolymer composition comprising: (1) 10 to 90% by weight of a binder having a viscosity of 0.943 to 0.975g/cm³Density d of¹Melt index I of 0.01 to 10 g/10min₂ ¹And a molecular weight distribution M of less than 3.0_w/M_nA first ethylene homopolymer of (a); and (2) 90 to 10% by weight of a binder having a viscosity of 0.950 to 0.985 g/cm³Density d of²A melt index I of at least 500g/10min₂ ²And a molecular weight distribution M of less than 3.0_w/M_nA second ethylene homopolymer of (a); wherein the second ethylene homopolymer has a melt index I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Has a ratio of at least 50, and wherein the polyethylene homopolymer composition has a weight average molecular weight M of 75,000 or less_wA high load melt index I of at least 200g/10 min₂₁And a molecular weight distribution M of 4.0 to 12.0_w/M_n。

Brief description of the drawings

Fig. 1 shows Gel Permeation Chromatograms (GPC) with refractive index measurements for polyethylene compositions made according to the present disclosure (examples 1 and 2) and two comparative polyethylene compositions (examples 3 and 4).

Fig. 2 shows the Oxygen Transmission Rate (OTR) vs. the weight average molecular weight (M) of the nucleated polyethylene compositions (examples 1 and 2) of compression molded films made from the nucleated polyethylene compositions according to the present disclosure (examples 1 and 2)_w). FIG. 2 also shows the Oxygen Transmission Rate (OTR) vs. weight average molecular weight (M) of the comparative nucleated polyethylene compositions (examples 3 and 4) for the compression molded films made from the comparative nucleated polyethylene compositions (examples 3 and 4)_w）。

Fig. 3 shows the Water Vapor Transmission Rate (WVTR) vs. the weight average molecular weight (M) of the nucleated polyethylene compositions (examples 1 and 2) made from the nucleated polyethylene compositions (examples 1 and 2) according to the present disclosure_w). FIG. 3 also shows the Water Vapor Transmission Rate (WVTR) vs. weight average molecular weight (M) of compression molded films made from the comparative nucleated polyethylene compositions (examples 3 and 4)_w）。

Fig. 4 shows the Oxygen Transmission Rate (OTR) vs. the weight average molecular weight (M) of the injection molded seals made from nucleated polyethylene compositions (examples 1 and 2) according to the present disclosure_w). FIG. 4 also shows the Oxygen Transmission Rate (OTR) vs. the weight average molecular weight (M) of injection molded seals made from the comparative nucleated polyethylene compositions (examples 3 and 4)_w）。

Description of the preferred embodiments

The term "ethylene homopolymer" or "polyethylene homopolymer" or "ethylene homopolymer composition" means that the polymer referred to is the product of a polymerization process in which ethylene is intentionally added as the only polymerizable olefin. In contrast, the term "ethylene copolymer" or "polyethylene copolymer composition" means that the polymer referred to is the product of a polymerization process in which ethylene and one or more than one alpha olefin comonomer are intentionally added as polymerizable olefins.

The term "unimodal" is defined herein to mean that there will be only one distinct peak or maximum in the GPC curve. A unimodal curve includes a broad unimodal curve. Alternatively, the term "unimodal" means that there is a single maximum in the molecular weight distribution curve generated according to the method of ASTM D6474-99. In contrast, the term "bimodal" means that there will be a distinct secondary distribution peak or shoulder in the GPC curve, which represents a higher or lower molecular weight component (i.e. the molecular weight distribution can be said to have two maxima in the molecular weight distribution curve). Alternatively, the term "bimodal" means that there are two maxima in the molecular weight distribution curve generated according to the method of ASTM D6474-99. The term "multimodal" means that there are two or more maxima in the molecular weight distribution curve generated according to the method of ASTM D6474-99.

In one embodiment of the present disclosure, the polymer composition comprises from 1 to 100 wt% of the polyethylene homopolymer composition.

In one embodiment of the present disclosure, the polyethylene homopolymer composition comprises two components: (1) a first ethylene homopolymer; and (2) a second ethylene homopolymer different from the first homopolymer.

In one embodiment of the present disclosure, the polyethylene homopolymer composition comprises only two polymer components: (1) a first ethylene homopolymer; and (2) a second ethylene homopolymer different from the first homopolymer.

In one embodiment of the present disclosure, the polyethylene homopolymer composition further comprises a nucleating agent.

The first and second ethylene homopolymers are further defined below.

A first ethylene homopolymer

In one embodiment of the present disclosure, the first ethylene homopolymer is made using a single-site polymerization catalyst.

In one embodiment of the present disclosure, the first ethylene homopolymer is made in a solution phase polymerization process using a single-site polymerization catalyst.

In one embodiment of the present disclosure, the first ethylene homopolymer is made as follows: a single site polymerization catalyst is used to polymerize ethylene as the only monomer intentionally added in a solution phase polymerization process.

In one embodiment of the present disclosure, the first ethylene homopolymer has a melt index, I₂ ¹Melt index I less than that of the second ethylene homopolymer₂ ²。

In embodiments of the present disclosure, the first ethylene homopolymer has a melt index I ≦ 20.0 g/10min, or ≦ 15.0 g/10min, or ≦ 10.0 g/10min₂ ¹. In another embodiment of the present disclosure, the first ethylene homopolymer has a melt index I of from 0.01 to 15.0 g/10min₂ ¹Including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the first ethylene homopolymer has a melt index, I₂ ¹Can be 0.01 to 10.0 g/10min, or 0.01 to 7.5 g/10min, or 0.01 to 5.0 g/10min, or 0.01 to 3.0 g/10min, or 0.1 to 15.0 g/10min, or 0.1 to 10.0 g/10min, or 0.1 to 5.0 g/10min, or 0.1 to 3.0 g/10 min.

In one embodiment of the present disclosure, the first ethylene homopolymer has a melt flow ratio, I, of less than 25, or less than 23, or less than 20₂₁/I₂。

In one embodiment of the present disclosure, the first ethylene homopolymer has a weight average molecular weight, M, of from 40,000 to 250,000 g/mol_wIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the first ethylene homopolymer has a weight average molecular weight, M, of from 50,000 to 200,000 g/mol, or from 60,000 to 175,000 g/mol, or from 60,000 to 150,000 g/mol, or from 50,000 to 130,000 g/mol, or from 60,000 to 130,000 g/mol_w。

In embodiments of the present disclosure, the first ethylene homopolymer has ≦ 3.0, or<3.0 or less than or equal to 2.7 or<2.7, or less than or equal to 2.5, or<2.5, or less than or equal to 2.3, or<2.3, or less than or equal to 2.1, or<Molecular weight distribution M of 2.1 or about 2_w/M_n. In another embodiment of the present disclosure, the first ethylene homopolymer has a molecular weight distribution, M, of from 1.7 to 3.0_w/M_nIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the first ethylene homopolymer has a molecular weight distribution, M, of from 1.8 to 2.7, or from 1.8 to 2.5, or from 1.8 to 2.3, or from 1.9 to 2.1_w/M_n。

In one embodiment of the present disclosure, the density d of the first homopolymer¹Density d less than that of the second ethylene homopolymer²。

In one embodiment of the present disclosure, the first ethylene homopolymer has from 0.930 to 0.985 g/cm³Density d of¹Including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the first ethylene homopolymer has from 0.930 to 0.980 g/cm³Or 0.930 to 0.975g/cm³Or 0.935 to 0.980 g/cm³Or 0.940 to 0.980 g/cm³Or 0.940 to 0.975g/cm³Or 0.943 to 0.980 g/cm³Or 0.943 to 0.975g/cm³Or 0.943 to 0.970 g/cm³Or 0.943 to 0.965 g/cm³Or 0.945 to 0.980 g/cm³Or 0.945 to 0.975g/cm³Or 0.945 to 0.970 g/cm³Or 0.945 to 0.965 g/cm³Or 0.946 to 0.980 g/cm³Or 0.946 to 0.975g/cm³Or 0.946 to 0.970 g/cm³Or 0.946 to 0.965 g/cm³Or 0.940 to 0.962 g/cm³Or 0.940 to 0.960 g/cm³Or 0.943 to 0.962 g/cm³Density d of¹。

In embodiments of the present disclosure, the weight percent (wt%) of the first ethylene homopolymer in the polyethylene homopolymer composition (i.e., the weight percent of the first ethylene homopolymer based on the total weight of the first and second ethylene homopolymers) can be from about 5 wt% to about 95 wt%, including any narrower ranges within this range and any values encompassed by these ranges. For example, in embodiments of the present disclosure, the weight percent (wt%) of the first ethylene homopolymer in the polyethylene homopolymer composition can be from about 5 wt% to about 90 wt%, or from about 10 wt% to about 90 wt%, or from about 15 to about 80 wt%, or from about 20 wt% to about 80 wt%, or from about 25 wt% to about 75 wt%, or from about 30 wt% to about 70 wt%, or from about 35 wt% to about 65 wt%, or from about 40 wt% to about 70 wt%, or from about 45 wt% to about 65 wt%, or from about 50 wt% to about 60 wt%.

Second ethylene homopolymer

In one embodiment of the present disclosure, the second ethylene homopolymer is made using a single site polymerization catalyst.

In one embodiment of the disclosure, the second ethylene homopolymer is made in a solution phase polymerization process using a single site polymerization catalyst.

In one embodiment of the disclosure, the second ethylene homopolymer is made by: a single site polymerization catalyst is used to polymerize ethylene as the only monomer intentionally added in a solution phase polymerization process.

In one embodiment of the disclosure, the second ethylene homopolymer has a melt index, I₂ ²Greater than the melt index I of the first ethylene homopolymer₂ ¹。

In one embodiment of the disclosure, the second ethylene homopolymer has a melt index, I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Is at least 25, or at least 50, or at least 100, or at least 1,000, or at least 5,000, or at least 7,500.

In one embodiment of the disclosure, the second ethylene homopolymer has a melt index, I₂ ²Melt index I for the first ethylene homopolymer₂ ¹Is from 25 to 30,000, including any narrower ranges within the range and any values encompassed within the ranges. For example, in embodiments of the present disclosure, the melt index, I, of the second ethylene homopolymer₂ ²Melt index I for the first ethylene homopolymer₂ ¹The ratio of (a) may be 50 to 30,000, or 100 to 30,000, or 1000 to 30,000, or 5,000 to 30,000, or 50 to 25,000, or 100 to 25,000, or 1,000 to 25,000, or 5,000 to 25,000, or 7,500 to 30,000, or 7,500 to 25,000.

In embodiments of the present disclosure, the second ethylene homopolymer has a melt index I of at least 250g/10min, or at least 500g/10min, or at least 1,000 g/10min, or at least 5,000 g/10min, or at least 75,000 g/10min, or at least 10,000 g/10min₂ ². In another embodiment of the present disclosure, the second ethylene homopolymer has a melt index I of 250 to 20,000 g/10min₂ ²Including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the melt index, I, of the second ethylene homopolymer₂ ²May be 500 to 15,000 g/10min, or 1000 to 17,500 g/10min, or 2,500 to 20,000 g/10min, or 5,000 to 17,500 g/10min, or 1000 to 20,000 g/10min, or 2,500 to 17,500 g/10min, or 7,500 to 20,000 g/10min, or 7,500 to 17,500 g/10min, or 7,500 to 15,000 g/10min, or 5,000 to 15,000 g/10 min.

In one embodiment of the disclosure, the second ethylene homopolymer has a melt flow ratio, I, of less than 25, or less than 23, or less than 20₂₁/I₂。

In one embodiment of the present disclosure, the second ethylene homopolymer has a weight average molecular weight M of 65,000 g/mol or less, or 55,000 g/mol or less, or 45,000 g/mol or less, or 35,000 g/mol or less, or 25,000 g/mol or less, or 15,000 g/mol or less, or 10,000 g/mol or less_w. In another embodiment, the second ethylene homopolymer has a weight average molecular weight M of from 2,500 to 70,000 g/mol_wIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the second ethylene homopolymer has a weight average molecular weight, M, of from 2,500 to 60,000 g/mol, or from 2,500 to 50,000 g/mol, or from 2,500 to 40,000 g/mol, or from 2,500 to 30,000 g/mol, or from 2,500 to 20,000 g/mol, or from 2,500 to 15,000 g/mol, or from 5,000 to 30,000 g/mol, or from 5,000 to 20,000 g/mol, or from 5,000 to 25,000 g/mol, or from 2,500 to 25,000 g/mol_w。

In embodiments of the present disclosure, the second ethylene homopolymer has ≦ 3.0, or<3.0 or less than or equal to 2.7 or<2.7, or less than or equal to 2.5, or<2.5, or less than or equal to 2.3, or<2.3, or less than or equal to 2.1, or<Molecular weight distribution M of 2.1 or about 2_w/M_n. In another embodiment of the present disclosure, the second ethylene homopolymer has a molecular weight distribution, M, of from 1.7 to 3.0_w/M_nIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the second ethylene homopolymer has a molecular weight distribution, M, of 1.8 to 2.7, or 1.8 to 2.5, or 1.8 to 2.3, or 1.9 to 2.1_w/M_n。

In one embodiment of the present disclosure, the density d of the second homopolymer²Greater than the density d of the first ethylene homopolymer¹。

In one embodiment of the disclosure, the density d of the second ethylene homopolymer²Density d of the first ethylene homopolymer¹Less than 0.035 g/cm³. In one embodiment of the disclosure, the density d of the second ethylene homopolymer²Less than 0.030 g/cm³. In one embodiment of the disclosure, the density d of the second ethylene homopolymer²Density d of the first ethylene homopolymer¹Less than 0.025 g/cm³。

In one embodiment of the disclosure, the second ethylene homopolymer has from 0.940 to 0.985 g/cm³Density d of²Including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the second ethylene homopolymer has from 0.943 to 0.985 g/cm³Or 0.945 to 0.985 g/cm³Or 0.950 to 0.985 g/cm³Or 0.950 to 0.980 g/cm³Or 0.953 to 0.985 g/cm³Or 0.953 to 0.980 g/cm³Or 0.955 to 0.985 g/cm³Or 0.955 to 0.980 g/cm³Or 0.955 to 0.975g/cm³Or 0.950 to 0.975g/cm³Or 0.957 to 0.985 g/cm³Or 0.957 to 0.980 g/cm³Or 0.957 to 0.975g/cm³Or 0.959 to 0.985 g/cm³Or 0.959 to 0.980 g/cm³Or 0.959 to 0.975g/cm³Density d of²。

In embodiments of the present disclosure, the weight percent (wt%) of the second ethylene homopolymer in the polyethylene homopolymer composition (i.e., the wt% of the second ethylene homopolymer based on the total weight of the first and second ethylene homopolymers) can be from about 5 wt% to about 95 wt%, including any narrower ranges within this range and any values encompassed within these ranges. For example, in embodiments of the present disclosure, the weight percent (wt%) of the second ethylene homopolymer in the polyethylene homopolymer composition can be from about 5 wt% to about 90 wt%, or from about 10 wt% to about 90 wt%, or from about 15 to about 80 wt%, or from about 20 wt% to about 80 wt%, or from about 25 wt% to about 75 wt%, or from about 30 wt% to about 70 wt%, or from about 35 wt% to about 65 wt%, or from about 35 wt% to about 60 wt%, or from about 35 wt% to about 55 wt%, or from about 40 wt% to about 50 wt%.

Polyethylene homopolymer composition

In one embodiment of the present disclosure, the polyethylene homopolymer composition will comprise a first ethylene homopolymer and a second ethylene homopolymer (each as defined herein).

In one embodiment of the present disclosure, the polyethylene homopolymer composition has a bimodal curve (i.e., molecular weight distribution) in Gel Permeation Chromatography (GPC) analysis.

In one embodiment of the present disclosure, the polyethylene composition has a bimodal profile in a gel permeation chromatogram generated according to the method of ASTM D6474-99.

In one embodiment of the present disclosure, the polyethylene homopolymer composition has 100,000 g/mol or less, or 75,000 g/mol or less, or<70,000 g/mol, or 65,000 g/mol or less, or<65,000 g/mol, or 60,000 g/mol or less, or<Weight average molecular weight M of 60,000 g/mol_w. In another embodiment, the polyethylene homopolymer composition has a weight average molecular weight M of from 10,00 to 75,000 g/mol_wIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has 15,000 to 75,000 g/mol, or 15,000 to 70,000 g/mol, or 20,000 to 75,000 g/mol, or 25,000 to 75,000 g/mol, or 30,000 to 75,000 g/mol, or 25,000 to 70,000 g/mol, or 25,000 to 65,000 g/mol, or 25,000 to 60,000 g/mol, or 30,000 to 75,000 g/mol, or 30,000 to 70,0A weight average molecular weight M of 00 g/mol, or 30,000 to 65,000 g/mol, or 35,000 to 75,000 g/mol, or 35,000 to 70,000 g/mol, or 35,000 to 65,000 g/mol_w。

In one embodiment of the present disclosure, the polyethylene homopolymer composition has 50,000 g/mol or less, or 40,000 g/mol or less, or<40,000 g/mol, or less than or equal to 30,000 g/mol, or<30,000 g/mol, or less than or equal to 20,000 g/mol, or<20,000 g/mol, or less than or equal to 15,000 g/mol, or<15,000 g/mol, or less than or equal to 10,000 g/mol, or<Number average molecular weight M of 10,000 g/mol_n. In another embodiment of the present disclosure, the polyethylene homopolymer composition has a number average molecular weight M of 1,000 to 50,000 g/mol_nIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has a number average molecular weight of 1,000 to 40,000 g/mol, or 1,000 to 30,000 g/mol, or 1,000 to 20,000 g/mol, or 1,000 to 15,000 g/mol, or 1,000 to 10,000 g/mol, or 2,500 to 35,000 g/mol, or 2,500 to 30,000 g/mol, or 2,500 to 25,000 g/mol, or 2,500 to 20,000 g/mol, or 2,500 to 15,000 g/mol, or 2,500 to 10,000 g/mol, or 5,000 to 35,000 g/mol, or 5,000 to 30,000 g/mol, or 5,000 to 25,000 g/mol, or 5,000 to 20,000 g/mol, or 5,000 to 15,000 g/mol, or 5,000 to 10,000M/mol_n。

In embodiments of the present disclosure, the polyethylene homopolymer composition has a molecular weight distribution, M, of from 3.0 to 15.0_w/M_nIncluding any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has a molecular weight distribution, M, of from 3.5 to 15.0, or from 3.0 to 12.0, or from 4.0 to 15.0, or from 4.0 to 12.0, or from 4.0 to 10.0, or from 4.0 to 9.0_w/M_n。

In one embodiment of the present disclosure, the polyethylene homopolymer composition has 0.943 to 0.987 g/cm³Including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has a molecular weight of 0.945 to 0.985 g/cm³Or 0.947 to 0.985 g/cm³Or 0.950 to 0.985 g/cm³Or 0.953 to 0.985 g/cm³Or 0.955 to 0.985 g/cm³Or 0.961 to 0.085 g/cm³Or 0.945 to 0.980 g/cm³Or 0.947 to 0.980 g/cm³Or 0.950 to 0.980 g/cm³Or 0.951 to 0.980 g/cm³Or 0.953 to 0.980 g/cm³Or 0.955 to 0.980 g/cm³Or 0.961 to 0.980 g/cm³Or 0.945 to 0.975g/cm³Or 0.947 to 0.975g/cm³Or 0.950 to 0.975g/cm³Or 0.951 to 0.975g/cm³Or 0.953 to 0.975g/cm³Or 0.955 to 0.975g/cm³Or 0.961 to 0.975g/cm³Or 0.945 to 0.970 g/cm³Or 0.947 to 0.970 g/cm³Or 0.950 to 0.970 g/cm³Or 0.951 to 0.970 g/cm³Or 0.953 to 0.970 g/cm³Or 0.955 to 0.970 g/cm³Or 0.961 to 0.970 g/cm³The density of (c).

In embodiments of the present disclosure, the polyethylene homopolymer composition has ≧ 0.950 g/cm³Or is> 0.950 g/cm³Or not less than 0.955 g/cm³Or is> 0.955 g/cm³Or not less than 0.960 g/cm³Or is> 0.960 g/cm³Or not less than 0.965 g/cm³Or is> 0.965 g/cm³The density of (c).

In embodiments of the present disclosure, the polyethylene homopolymer composition has at least 1.0 g/10min (. gtoreq.1.0 g/10min), or at least 3.0 g/10min (. gtoreq.3.0 g/10min), or at least 5.0 g/10min (. gtoreq.5.0 g/10min), or at least 7.5 g/10min (. gtoreq.7.5 g/10min), or at least 10.0 g/10min (. gtoreq.10.0 g/10min), or more than 3.0 g/10min>3.0 g/10min), or more than 5.0 g/10min (>5.0 g/10min), or more than 7.5 g/10min (>7.5 g/10min), or more than 10.0 g/10min (>10.0 g/10min) of a melt index I₂. In another embodiment of the present disclosure, the polyethylene homopolymer composition has a melt index I of 1.0 to 250g/10min₂Including any narrower ranges within the indicated ranges and subsumed thereinAny value of the lid. For example, in embodiments of the present disclosure, the melt index, I, of the polyethylene homopolymer composition₂May be 1.0 to 200g/10 min, or 1.0 to 150 g/10min, or 1 to 100 g/10min, or 1 to 50g/10min, or 10.0 to 200g/10 min, or 10.0 to 150 g/10min, or 10.0 to 100 g/10min, or 10.0 to 50g/10min, or 7.5 to 200g/10 min, or 7.5 to 150 g/10min, or 7.5 to 100 g/10min, or 7.5 to 50g/10min, or 5.0 to 200g/10 min, or 5.0 to 150 g/10min, or 5.0 to 100 g/10min, or 5.0 to 75 g/10min, or 5.0 to 50g/10min, or 5.0 to 40 g/10min, or 3.0 to 100 g/10min, or 3.0 to 75 g/10min, or 3.0 to 40 g/10min, or 3.0 to 100 g/10min, or 3.0 to 10min, Or 7.5 to 40 g/10min, or 7.5 to 30 g/10 min.

In embodiments of the present disclosure, the polyethylene homopolymer composition has at least 200g/10 min (. gtoreq.200 g/10min), or at least 250g/10min (. gtoreq.250 g/10min), or at least 300 g/10min (. gtoreq.300 g/10min), or at least 350 g/10min (. gtoreq.350 g/10min), or at least 400 g/10min (. gtoreq.400 g/10min), or more than 200g/10 min (C.) (10 min)>200g/10 min), or more than 250g/10min (>250g/10 min), or more than 300 g/10min (>300 g/10min), or more than 350 g/10min (>350 g/10min), or more than 400 g/10min (>400 g/10min) high load melt index I₂₁. In another embodiment of the present disclosure, the polyethylene homopolymer composition has a high load melt index I of 200 to 2500 g/10min₂₁Including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the high load melt index, I, of the polyethylene homopolymer composition₂₁May be 200 to 2,000 g/10min, or 200 to 1,500 g/10min, 200 to 1,000 g/10min, or 200 to 800g/10 min.

In embodiments of the present disclosure, the polyethylene homopolymer composition has a value of 50 or less, or<50. Or less than or equal to 45, or<40. Or less than or equal to 35, or<35 melt flow ratio I₂₁/I₂. In another embodiment of the present disclosure, the polyethylene homopolymer composition has a melt flow ratio, I, of from 12 to 75₂₁/I₂Including any narrower ranges within the range andany value encompassed by these ranges. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has a melt flow ratio, I, of 14 to 60, or 14 to 50, or 16 to 40, or 18 to 50, or 18 to 40, or 20 to 50, or 20 to 45, or 20 to 40₂₁/I₂。

In one embodiment of the present disclosure, the polyethylene homopolymer composition has a stress index ≦ 1.40, defined as Log₁₀[I₆/I₂]/Log₁₀[6.48/2.16]. In further embodiments of the present disclosure, the polyethylene composition has a stress index Log of less than 1.38, or less than 1.36, or less than 1.34, or less than 1.32, or less than 1.30, or less than 1.28₁₀[I₆/I₂]/Log₁₀[6.48/2.16]。

In one embodiment of the present disclosure, the polyethylene homopolymer composition has a molecular weight of about 10⁵ s^-1A shear viscosity at (240 ℃) of less than about 8 Pa.s. In one embodiment of the present disclosure, the polyethylene homopolymer composition has a molecular weight of about 10⁵ s^-1A shear viscosity at (240 ℃) of about 1 to about 8pa.s, including any narrower range within the range and any value encompassed by the ranges. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has a molecular weight of about 10⁵ s^-1A shear viscosity of from about 2 to about 6 Pa.s, or from about 2 to about 5Pa.s, or from about 3 to about 5Pa.s at (240 ℃).

In one embodiment of the invention, the polyethylene homopolymer composition has a shear viscosity ratio SVR (SVR) at 240 ℃_100,100000) And can be from about 10 to about 80 inclusive, including any narrower ranges within the range and any values encompassed within the range. For example, in embodiments of the present disclosure, the polyethylene homopolymer composition has a shear viscosity ratio, SVR, (at 240 ℃_100,100000) And may be from about 20 to about 80, or from about 30 to about 80, or from about 20 to about 70, or from about 30 to about 70.

In one embodiment of the present disclosure, the polyethylene homopolymer composition has ≦ 5.5 wt%, or less than 4.5 wt%, or less than 3.5 wt%, or less than 2.5 wt%, or less than 2.0 wt%, or less than 1.5 wt%, or less than 1.0 wt%, or less than 0.75 wt% hexane extractable value.

In one embodiment of the present disclosure, the polyethylene homopolymer composition or molded article (or panel) made from the polyethylene homopolymer composition has an environmental stress crack resistance ESCR condition B at 100% of less than 50 hours, or less than 40 hours, or less than 30 hours, or less than 20 hours, or less than 10 hours, or less than 5 hours, measured according to ASTM D1693 (at 100% IGEPAL and 50 ℃ under condition B).

The polyethylene homopolymer compositions of the present disclosure can be prepared using any conventional blending method, such as, but not limited to, physical blending and in situ blending by polymerization in a multiple reactor system. For example, mixing a first ethylene homopolymer with a second ethylene homopolymer can be performed by melt mixing two preformed polymers. Processes for preparing the first and second ethylene homopolymers in at least two consecutive polymerization stages are preferred, however, for the purposes of this disclosure, both series or parallel dual reactor processes are contemplated. Gas, slurry or solution phase reactor systems may be employed, with solution phase reactor systems being preferred.

Mixed catalyst single reactor systems may also be used to prepare the polyethylene homopolymer compositions of the present disclosure.

In one embodiment of the present disclosure, a dual reactor solution polymerization process is employed as described, for example, in U.S. Pat. No. 6,372,864 and U.S. patent application No. 20060247373a1, which are incorporated herein by reference.

Typically, the catalyst used in the present disclosure will be a so-called single site catalyst based on a group 4 metal having at least one cyclopentadienyl ligand. Examples of such catalysts (which include metallocenes, constrained geometry catalysts, and phosphinimine catalysts) are typically used in combination with an activator selected from methylaluminoxane, borane, or an ionic borate, and are further described in U.S. Pat. nos. 3,645,992; 5,324,800; 5,064,802; 5,055,438; 6,689,847, respectively; 6,114,481 and 6,063,879. Such single-site catalysts are distinguished from the sameAre conventional ziegler-natta catalysts or Phillips catalysts known in the art. Generally, single-site catalysts give rise to a molecular weight distribution (M)_w/M_n) Less than about 3.0, or in some cases less than about 2.5.

In embodiments of the present disclosure, the use of a molecular weight distribution (M) in the preparation of each of the first and second ethylene homopolymers_w/M_n) A single site catalyst of an ethylene homopolymer of less than about 3.0, or less than about 2.7, or less than about 2.5.

In one embodiment of the present disclosure, the first and second ethylene homopolymers are prepared using an organometallic complex of a group 3, 4, or 5 metal, which is further characterized as having a phosphinimine ligand. Such complexes, when active for olefin polymerization, are commonly referred to as phosphinimine (polymerization) catalysts. Some non-limiting examples of phosphinimine catalysts can be found in U.S. patent nos. 6,342,463; 6,235,672, respectively; 6,372,864; 6,984,695, respectively; 6,063,879, respectively; 6,777,509 and 6,277,931, both of which are incorporated herein by reference.

Some non-limiting examples of metallocene catalysts can be found in U.S. Pat. nos. 4,808,561; 4,701,432; 4,937,301, respectively; 5,324,800; 5,633,394, respectively; 4,935,397, respectively; 6,002,033 and 6,489,413, both of which are incorporated herein by reference. Some non-limiting examples of constrained geometry catalysts can be found in U.S. Pat. nos. 5,057,475; 5,096,867, respectively; 5,064,802; 5,132, 380; 5,703,187 and 6,034,021, all of which are incorporated herein by reference in their entirety.

In one embodiment of the present disclosure, it is preferred to use single site catalysts that do not produce Long Chain Branching (LCB). Hexyl (C6) branches detected by NMR are not included in the definition of long chain branches of the present disclosure.

Without wishing to be bound by any single theory, long chain branching can increase viscosity at low shear rates, thereby adversely affecting cycle time during the manufacture of caps and seals, such as during compression molding. Long chain branching may be employed¹³C NMR method and can be used with Randall in Rev. Macromol. chem. Phys. C29 (2 and 3), page 285 for quantitative evaluation.

In one embodiment of the present disclosure, the polyethylene homopolymer composition will contain less than 0.3 long chain branches per 1000 carbon atoms. In another embodiment of the present disclosure, the polyethylene homopolymer composition will contain less than 0.01 long chain branches per 1000 carbon atoms.

In one embodiment of the present disclosure, a polyethylene homopolymer composition (as defined above) is prepared by contacting ethylene, as the sole polymerizable monomer, with a polymerization catalyst under solution phase polymerization conditions in at least two polymerization reactors (see, for example, U.S. Pat. Nos. 6,372,864; 6,984,695 and U.S. application No. 20060247373A1, which are incorporated herein by reference).

In one embodiment of the present disclosure, a polyethylene homopolymer composition is prepared by contacting at least one single-site polymerization catalyst system (comprising at least one single-site catalyst and at least one activator) with ethylene as the sole polymerizable monomer under solution polymerization conditions in at least two polymerization reactors.

In one embodiment of the present disclosure, a group 4 single-site catalyst system comprising a single-site catalyst and an activator is used in a solution-phase dual reactor system to prepare a polyethylene homopolymer composition by polymerization of ethylene.

In one embodiment of the present disclosure, a group 4 phosphinimine catalyst system comprising a phosphinimine catalyst and an activator is used in a solution-phase dual reactor system to prepare a polyethylene homopolymer composition by polymerization of ethylene.

In one embodiment of the present disclosure, a solution-phase dual reactor system includes two solution-phase reactors connected in series.

In one embodiment of the present disclosure, a polymerization process for preparing a polyethylene homopolymer composition comprises contacting at least one single-site polymerization catalyst system (comprising at least one single-site catalyst and at least one activator) with ethylene under solution polymerization conditions in at least two polymerization reactors.

In one embodiment of the present disclosure, a polymerization process for preparing a polyethylene homopolymer composition includes contacting at least one single-site polymerization catalyst system with ethylene under solution polymerization conditions in a first reactor and a second reactor configured in series.

Producing the polyethylene homopolymer compositions of the present disclosure will typically include an extrusion or compounding step. Such steps are well known in the art.

The polyethylene homopolymer composition may comprise other polymer components in addition to the first and second ethylene homopolymers. Such polymer components include polymers prepared in situ or added to the polymer composition during an extrusion or compounding step.

Optionally, additives may be added to the polyethylene homopolymer composition. The additives may be added to the polyethylene homopolymer composition during the extrusion or compounding step, but other suitable known methods will be apparent to those skilled in the art. The additives may be added as such, or as part of a separate polymer component (i.e., not the first or second ethylene homopolymers described herein), or as part of a masterbatch (optionally during an extrusion or compounding step). Suitable additives are known in the art and include, but are not limited to, antioxidants, phosphites and phosphonites, nitrones, antacids, ultraviolet light stabilizers, UV absorbers, metal deactivators, dyes, fillers and reinforcing agents, nanoscale organic or inorganic materials, antistatic agents, lubricants such as calcium stearate, slip additives such as erucamide or behenamide, and nucleating agents (including nucleating agents), pigments, or any other chemical that can provide nucleation for a polyethylene homopolymer composition. Additives that may optionally be added are generally added in amounts up to 20 weight percent (wt%).

The nucleating agent or agents can be introduced into the polyethylene homopolymer composition by kneading the polymer mixture (usually in powder or pellet form) with the nucleating agent which can be used alone or in the form of a concentrate containing other additives, such as stabilizers, pigments, antistatic agents, UV stabilizers and fillers. It should be a material which is wetted or absorbed by the polymer, is insoluble in the polymer and has a melting point higher than that of the polymer, and it should be uniformly dispersible in the polymer melt in as fine a form as possible (1 to 10 μm). Compounds known to have nucleating capabilities for polyolefins include salts of aliphatic mono-or diacids or arylalkyl acids, such as sodium succinate or aluminum phenylacetate; and alkali metal or aluminium salts of aromatic or cycloaliphatic carboxylic acids, such as sodium beta-naphthoate or sodium benzoate.

Some non-limiting examples of nucleating agents that are commercially available and that can be added to polyethylene homopolymer compositions are dibenzylidene sorbitol esters (such as those sold under the trademark MILLAD 3988 by Milliken Chemical and under the trademark IRGACLEAR by Ciba Specialty Chemicals). Other non-limiting examples of nucleating agents that may be added to the polyethylene homopolymer composition include cyclic organic structures (and salts thereof, such as disodium bicyclo [2.2.1] heptenedicarboxylate) disclosed in U.S. Pat. No. 5,981,636; the saturated form of the structure disclosed in U.S. Pat. No. 5,981,636 (as disclosed in U.S. Pat. No. 6,465,551; Zhao et al, to Milliken); salts of certain cyclic dicarboxylic acids having a hexahydrophthalic acid structure (or "HHPA" structure) as disclosed in U.S. patent No. 6,599,971 (Dotson et al, to Milliken); and phosphates such as those disclosed in U.S. Pat. No. 5,342,868 and those sold under the trade names NA-11 and NA-21 by Asahi Denka Kogyo, cyclic dicarboxylic acid esters and salts thereof, divalent metal or metalloid salts (particularly calcium salts) of the HHPA structure as disclosed in U.S. Pat. No. 6,599,971. For clarity, HHPA structures typically include a ring structure having 6 carbon atoms in the ring and two carboxylic acid groups (which are substituents on adjacent atoms of the ring structure). The other four carbon atoms in the ring may be substituted as disclosed in U.S. Pat. No. 6,599,971. An example is 1, 2-cyclohexanedicarboxylic acid, calcium salt (CAS registry number 491589-22-1). Still other non-limiting examples of nucleating agents that may be added to the polyethylene homopolymer composition include those disclosed in WO2015042561, WO2015042563, WO2015042562 and WO 2011050042.

Many of the above nucleating agents can be difficult to mix with the polyethylene homopolymer composition to be nucleated, and it is known to use dispersing aids (e.g., zinc stearate) to alleviate this problem.

In one embodiment of the present disclosure, the nucleating agent is well dispersed in the polyethylene homopolymer composition.

In one embodiment of the present disclosure, the amount of nucleating agent used is relatively small — 100 to 4000 parts per million by weight (based on the weight of the polyethylene homopolymer composition), so one skilled in the art will recognize that care must be taken to ensure that the nucleating agent is well dispersed. In one embodiment of the present disclosure, the nucleating agent is added to the polyethylene homopolymer composition in finely divided form (less than 50 microns, especially less than 10 microns) to facilitate mixing. This type of "physical blend" (i.e., a mixture of a nucleating agent in solid form with a resin) is in some embodiments superior to a "masterbatch" (where the term "masterbatch" refers to the practice of first melt mixing an additive, in this case a nucleating agent, with a small amount of a polyethylene homopolymer composition, and then melt mixing the "masterbatch" with the remainder of the majority of the polyethylene homopolymer composition) using the nucleating agent.

In one embodiment of the present disclosure, an additive, such as a nucleating agent, can be added to a polyethylene homopolymer composition via a "masterbatch," where the term "masterbatch" refers to the practice of first melt mixing the additive (e.g., nucleating agent) with a small amount of the polyethylene homopolymer composition, and then melt mixing the "masterbatch" with the remainder of the majority of the polyethylene homopolymer composition.

In one embodiment of the present disclosure, the polyethylene homopolymer composition further comprises a nucleating agent.

In one embodiment of the present disclosure, the polyethylene homopolymer composition comprises 20 to 4,000 ppm (i.e., parts per million, based on the total weight of the first and second ethylene homopolymers in the polyethylene copolymer composition) of the nucleating agent.

In one embodiment of the present disclosure, the polyethylene homopolymer composition further comprises a dicarboxylic acidNucleating agents for salts of the compounds. A dicarboxylic acid compound is defined herein as an organic compound containing two carboxylic acid (-COOH) functional groups. The salt of the dicarboxylic acid compound will thus comprise one or more suitable cationic counterions, preferably metal cations, and a carboxylate (-COO) having two anions⁻) An organic compound of the group.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form a molded article. Such articles may be formed by compression molding, continuous compression molding, injection molding or blow molding. Such articles include, for example, caps, screw caps and seals for bottles, containers, pouches, vials, fitments, pharmaceutical bottles, and the like, including hinge (hinged) forms and tether (stuck) forms thereof.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form a fitment for bottles, bags, and the like.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used in flexible packaging.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form films, such as blown films, cast films and laminated or extruded films, or extrusion coatings and stretched films. Methods for preparing such membranes from polymers are well known to those skilled in the art.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used in extrusion coating film layers.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form one or more film layers that are part of a multilayer film or film structure. Methods of making such multilayer films or film structures are well known to those skilled in the art.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form any seal of any suitable design and size for use in any hot-fill process (or aseptic fill process) for filling any suitable bottle, container, or the like.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form a seal for bottles, containers, bags, and the like. For example, consider a seal for a bottle formed by continuous compression or injection molding. Such seals include, for example, caps for bottles, containers, bags, and the like, hinged caps, screw caps, hinged screw caps, snap-top caps (snap-top caps), hinged snap-top caps, and optionally, hinged seals.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form a fitment for a bag, container, or the like.

In one embodiment of the present disclosure, the polyethylene homopolymer composition is used to form a molded article. For example, consider an article formed by continuous compression molding and injection molding. Such articles include, for example, caps, screw caps, and seals for bottles.

Sealing element

The terms "lid" and "seal" are used interchangeably in this disclosure and each means a suitably shaped molded article for enclosing, sealing, closing or covering, etc., suitably shaped openings, suitably molded apertures, wide mouth structures (openings), etc., for use in combination with containers, bottles, cans, pouches, etc.

The seal comprises a one-piece seal or a seal comprising more than one part.

In one embodiment of the present disclosure, the above polyethylene homopolymer composition is used to form a seal.

In one embodiment of the present disclosure, the above polyethylene homopolymer composition is used to form a one-piece seal.

In one embodiment of the present disclosure, the above polyethylene homopolymer composition is used to form a seal with a Tamper Evident Band (TEB).

In one embodiment of the present disclosure, the above polyethylene homopolymer compositions are used to form seals for bottles, containers, bags, and the like. For example, consider a bottle seal formed by compression molding or injection molding. Such seals include, for example, hinged caps, hinged screw caps, hinged snap caps, and hinged seals for bottles, containers, bags, and the like.

In one embodiment of the present disclosure, the above polyethylene homopolymer composition is used to form a bottle closure assembly comprising a cap portion, a tether portion, and a retention tool portion.

In one embodiment of the present disclosure, the seal (or cap) is a screw cap for bottles, containers, bags, and the like.

In one embodiment of the present disclosure, the seal (or cap) is a snap seal for bottles, containers, pouches, and the like.

In one embodiment of the present disclosure, the seal (or lid) comprises a hinge made of the same material as the rest of the seal (or lid).

In one embodiment of the present disclosure, the seal (or lid) is a hinged seal.

In one embodiment of the present disclosure, the seal (or cap) is a hinged seal for bottles, containers, bags, and the like.

In one embodiment of the present disclosure, the seal (or lid) is used for retort (retort), hot fill, aseptic fill, and cold fill applications.

In one embodiment of the present disclosure, the seal (or lid) is a flip-hinge seal, such as that used on plastic ketchup bottles or similar containers containing food.

When the seal is a hinged seal, it includes a hinge assembly and is typically composed of at least two bodies connected by at least one thinner section that acts as a so-called "living hinge" to allow the at least two bodies to bend from an initial molded position. The one or more thinner sections may be continuous or mesh (web-like), wide or narrow.

Useful seals (for bottles, containers, etc.) are hinged seals and may be made up of two bodies connected to each other by at least one thinner bendable portion (e.g., the two bodies may be connected by a single bridge or more than one bridge or by a web portion, etc.). The first body may contain a dispensing orifice (dispensing hole) and it may be snapped onto or screwed onto the container to cover the container opening (e.g. the mouth of a bottle), while the second body may act as a snap-on lid (snap on lid) which is cooperable with the first body.

The caps and seals (where the hinge caps and seals and screw caps are a subset) may be prepared according to any known method, including, for example, injection and compression molding techniques as are well known to those skilled in the art. Thus, in one embodiment of the present disclosure, a seal (or cap) comprising a polyethylene homopolymer composition (as defined above) is prepared with a process comprising at least one compression molding step and/or at least one injection molding step.

In one embodiment, the caps and seals (including single-piece or multi-piece variants and hinged variants) comprise the above-described polyethylene homopolymer composition with good barrier properties as well as good processability. The seal and cap of this embodiment are therefore well suited for sealing bottles, containers and the like, such as bottles that may contain a liquid or food that may deteriorate (e.g., by contact with oxygen), including but not limited to liquids under appropriate pressure (i.e., carbonated beverages or potable liquids under appropriate pressure).

The seal and cap may also be used to seal bottles containing drinking or non-carbonated beverages (e.g., juices). Other applications include lids and seals for bottles, containers and bags containing food products, such as for example ketchup bottles and the like.

The seal and cap may be a one-piece seal or a two-piece seal including a seal and a liner.

The seal and cap may also have a multi-layer design, wherein the seal or cap comprises at least two layers, at least one of which is made from the polyethylene blend described herein.

In one embodiment of the present disclosure, the seal is made by continuous compression molding.

In one embodiment of the present disclosure, the seal is made by injection molding.

The seal described in this disclosure may be a seal suitable for use in a container sealing process (e.g., a hot-fill process, and in some cases, an aseptic fill process) that includes one or more steps of contacting the seal with a liquid at an elevated temperature. Such seals and methods are described, for example, in canadian patent application No. 2,914,353; 2,914,354, respectively; and 2,914,315.

In one embodiment of the present disclosure, the seal made is a PCO 1881 CSD seal having a weight of about 2.15 grams and having the following dimensions: seal height (excluding anti-tamper ring) = about 10.7 mm; seal height with anti-tamper ring = about 15.4 mm; outer diameter @ 4mm = about 29.6 mm; thread diameter = about 25.5 mm; bump seal (Bump seal) diameter = about 24.5 mm; bump seal thickness = about 0.7 mm; bump seal height = about 1.5 mm from olive center; hole (Bore) seal diameter = about 22.5 mm; hole seal thickness = about 0.9 mm; hole height from olive center = about 1.6 mm; top plate thickness (Top panel thickness) = about 1.2 mm; theft-band undercut diameter = about 26.3 mm; thread depth = about 1.1 mm; pitch = about 2.5 mm; thread root @ 4mm = 27.4 mm.

In one embodiment of the present disclosure, the seals were prepared using an injection molding process to prepare PCO 1881 CSD seals having a weight of about 2.15 grams and having the following dimensions: seal height (excluding anti-tamper ring) = about 10.7 mm; seal height with anti-tamper ring = about 15.4 mm; outer diameter @ 4mm = about 29.6 mm; thread diameter = about 25.5 mm; lobe seal diameter = about 24.5 mm; bump seal thickness = about 0.7 mm; bump seal height = about 1.5 mm from olive center; hole seal diameter = about 22.5 mm; hole seal thickness = about 0.9 mm; hole height from olive center = about 1.6 mm; top plate thickness = about 1.2 mm; theft-band undercut diameter = about 26.3 mm; thread depth = about 1.1 mm; pitch = about 2.5 mm; thread root @ 4mm = 27.4 mm.

In one embodiment of the present disclosure, the seals were prepared using a continuous injection molding process to make PCO 1881 CSD seals having a weight of about 2.15 grams and having the following dimensions: seal height (excluding anti-tamper ring) = about 10.7 mm; seal height with anti-tamper ring = about 15.4 mm; outer diameter @ 4mm = about 29.6 mm; thread diameter = about 25.5 mm; lobe seal diameter = about 24.5 mm; bump seal thickness = about 0.7 mm; bump seal height = about 1.5 mm from olive center; hole seal diameter = about 22.5 mm; hole seal thickness = about 0.9 mm; hole height from olive center = about 1.6 mm; top plate thickness = about 1.2 mm; theft-band undercut diameter = about 26.3 mm; thread depth = about 1.1 mm; pitch = about 2.5 mm; thread root @ 4mm = 27.4 mm.

In embodiments of the present disclosure, the seals are made using a molding process to make PCO 1881 CSD seals having ≦ 0.0030cm³Sealing element/day, or less than or equal to 0.0025cm³Sealing element/day, or less than or equal to 0.0021 cm³Sealing element/day, or less than or equal to 0.0020 cm³Sealing element/day, less than or equal to 0.0018 cm³Sealing element/day, or less than or equal to 0.0016 cm³Sealing element/day, or less than or equal to 0.0014 cm³Oxygen transmission rate per seal/day OTR.

In one embodiment of the present disclosure, the seals are made using a continuous compression molding process to make PCO 1881 CSD seals having ≦ 0.0030cm³Sealing element/day, or less than or equal to 0.0025cm³Sealing element/day, or less than or equal to 0.0021 cm³Sealing element/day, or less than or equal to 0.0020 cm³Sealing element/day, less than or equal to 0.0018 cm³Sealing element/day, or less than or equal to 0.0016 cm³Sealing element/day, or less than or equal to 0.0014 cm³Oxygen transmission rate per seal/day OTR.

In one embodiment of the present disclosure, the seal is made using an injection molding process to make a PCO 1881 CSD seal having ≦ 0.0030cm³Sealing element/day, or less than or equal to 0.0025cm³Sealing element/day, or less than or equal to 0.0021 cm³Sealing element/day, or less than or equal to 0.0020 cm³Sealing element/day, less than or equal to 0.0018 cm³Sealing element/day, or less than or equal to 0.0016 cm³Sealing element/day, or less than or equal to 0.0014 cm³Oxygen transmission rate per seal/day OTR.

In embodiments of the present disclosure, the seal is made using a molding process to make a PCO 1881 CSD seal having 0.0005 to 0.0025cm³Oxygen Permeability seal/dayThe rate OTR, including any narrower ranges within the range and any values encompassed within the ranges. For example, in embodiments of the present disclosure, a seal is prepared using a molding process to make a PCO 1881 CSD seal having 0.0006 to 0.0023 cm³Seal/day, or 0.0006 to 0.0021 cm³Seal/day, or 0.0006 to 0.0019 cm³Seal/day, or 0.0006 to 0.0017 cm³Seal/day, or 0.0006 to 0.0015cm³Seal/day, or 0.0006 to 0.0013 cm³Oxygen transmission rate per seal/day OTR.

In one embodiment of the present disclosure, the seal is prepared using a continuous compression molding process to make a PCO 1881 CSD seal having 0.0005 to 0.0025cm³The oxygen transmission rate per seal per day OTR, including any narrower ranges within the range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, a seal is prepared using a continuous compression molding process to make a PCO 1881 CSD seal having 0.0006 to 0.0023 cm³Seal/day, or 0.0006 to 0.0021 cm³Seal/day, or 0.0006 to 0.0019 cm³Seal/day, or 0.0006 to 0.0017 cm³Seal/day, or 0.0006 to 0.0015cm³Seal/day, or 0.0006 to 0.0013 cm³Oxygen transmission rate per seal/day OTR.

In one embodiment of the present disclosure, the seal is made using an injection molding process to make a PCO 1881 CSD seal having 0.0005 to 0.0025cm³The oxygen transmission rate per seal per day OTR, including any narrower ranges within the range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the seals are made using an injection molding process to make PCO 1881 CSD seals having 0.0006 to 0.0023 cm³Seal/day, or 0.0006 to 0.0021 cm³Seal/day, or 0.0006 to 0.0019 cm³Seal/day, or 0.0006 to 0.0017 cm³Seal/day, or 0.0006 to 0.0015cm³Seal/day, or 0.0006 to 0.0013 cm³Oxygen transmission rate per seal/day OTR.

Cast (and laminated) films

In one embodiment of the present disclosure, the above polyethylene homopolymer composition is used to form a cast film or a laminated film.

The cast film is optionally extruded from a flat die onto a chill roll or nip roll (nipped roll) using a vacuum box and/or air knife. The film may be a monolayer film or a coextruded multilayer film obtained by various extrusions through a single or multiple dies. The resulting film may be used as is, or may be laminated to other films or substrates, for example by heat, adhesive lamination, or direct extrusion onto a substrate. The resulting films and laminates can be subjected to other forming operations such as embossing, stretching, thermoforming. A corona, for example, may be applied at the surface and the film may be printed.

In the cast film extrusion process, the film is extruded through a slit onto a quenched, highly polished turning roll where it is quenched from one side. The speed of the rolls controls the draw ratio and the final film thickness. The film was then sent to a second roll to cool the other side. Finally, it passes through a system of rollers and is wound on a roll. In another embodiment, two or more thin films are coextruded through two or more slits onto a cooled, highly polished turning roll, and the coextruded films are quenched from one side. The speed of the rolls controls the draw ratio and final coextruded film thickness. The coextruded film is then sent to a second roll to cool the other side. Finally, it passes through a system of rollers and is wound on a roll.

In one embodiment, the cast film product can further laminate one or more layers into a multilayer structure.

Cast films and laminates are useful for a variety of purposes, such as food packaging (dry food, fresh food, frozen food, liquid, processed food, powders, granules), for packaging detergents, toothpastes, towels, for labels and release liners. The films are also useful for unitized and industrial packaging, particularly stretch films. Films are also used in hygiene and medical applications, such as breathable and gas-impermeable films for diapers, adult incontinence products, feminine hygiene products, ostomy bags. Finally, cast films can also be used in tape and artificial turf applications.

In embodiments of the present disclosure, the film or film layer has≤ 100cm³/100 in²Every day, or less than or equal to 90 cm³/100 in²Every day, or less than or equal to 80cm³/100 in²Every day, or less than or equal to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the compression molded film or film layer has 100 cm or less³/100 in²Every day, or less than or equal to 90 cm³/100 in²Every day, or less than or equal to 80cm³/100 in²Every day, or less than or equal to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the cast film or film layer has ≦ 100 cm³/100 in²Every day, or less than or equal to 90 cm³/100 in²Every day, or less than or equal to 80cm³/100 in²Every day, or less than or equal to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the laminated film or film layer has 100 cm or less³/100 in²Every day, or less than or equal to 90 cm³/100 in²Every day, or less than or equal to 80cm³/100 in²Every day, or less than or equal to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the film or film layer has 30 to 100 cm³/100 in²The normalized oxygen transmission rate OTR per day, including any narrower ranges within that range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the film or film layer has 30 to 90 cm³/100 in²A day, or 40 to 90 cm³/100 in²Every day, or 30 to 80cm³/100 in²A day, or 40 to 80cm³/100 in²Every day, or 30 to 70 cm³/100 in²A day, or 40 to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the compression molded film or film layer has 30 to 100 cm³/100 in²Normalized oxygen transmission rate OTR per day, including any narrower ranges within that range and those rangesAny value encompassed. For example, in embodiments of the present disclosure, the compression molded film or film layer has 30 to 90 cm³/100 in²A day, or 40 to 90 cm³/100 in²Every day, or 30 to 80cm³/100 in²A day, or 40 to 80cm³/100 in²Every day, or 30 to 70 cm³/100 in²A day, or 40 to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the cast film or film layer has 30 to 100 cm³/100 in²The normalized oxygen transmission rate OTR per day, including any narrower ranges within that range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the cast film or film layer has 30 to 90 cm³/100 in²A day, or 40 to 90 cm³/100 in²Every day, or 30 to 80cm³/100 in²A day, or 40 to 80cm³/100 in²Every day, or 30 to 70 cm³/100 in²A day, or 40 to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the laminated film or film layer has 30 to 100 cm³/100 in²The normalized oxygen transmission rate OTR per day, including any narrower ranges within that range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the laminated film or film layer has 30 to 90 cm³/100 in²A day, or 40 to 90 cm³/100 in²Every day, or 30 to 80cm³/100 in²A day, or 40 to 80cm³/100 in²Every day, or 30 to 70 cm³/100 in²A day, or 40 to 70 cm³/100 in²Normalized oxygen transmission rate OTR/day.

In embodiments of the present disclosure, the film or film layer has ≦ 0.250 g/100 in²Day, or less than or equal to 0.230 g/100 in²A day, or less than or equal to 0.210 g/100 in²A day, or less than or equal to 0.200 g/100 in²One day, or less than or equal to 0.190 g/100 in²Day, or less than or equal to 0.180 g/100 in²The return of one dayNormalized water vapor transmission rate WVTR.

In embodiments of the present disclosure, the compression molded film or film layer has ≦ 0.250 g/100 in²Day, or less than or equal to 0.230 g/100 in²A day, or less than or equal to 0.210 g/100 in²A day, or less than or equal to 0.200 g/100 in²One day, or less than or equal to 0.190 g/100 in²Day, or less than or equal to 0.180 g/100 in²Normalized water vapor transmission rate per day WVTR.

In embodiments of the present disclosure, the cast film or film layer has ≦ 0.250 g/100 in²Day, or less than or equal to 0.230 g/100 in²A day, or less than or equal to 0.210 g/100 in²A day, or less than or equal to 0.200 g/100 in²One day, or less than or equal to 0.190 g/100 in²Day, or less than or equal to 0.180 g/100 in²Normalized water vapor transmission rate per day WVTR.

In embodiments of the present disclosure, the laminate film or film layer has ≦ 0.250 g/100 in²Day, or less than or equal to 0.230 g/100 in²A day, or less than or equal to 0.210 g/100 in²A day, or less than or equal to 0.200 g/100 in²One day, or less than or equal to 0.190 g/100 in²Day, or less than or equal to 0.180 g/100 in²Normalized water vapor transmission rate per day WVTR.

In embodiments of the present disclosure, the film or film layer has 0.080 to 0.250 g/100 in²Normalized water vapor transmission rate per day WVTR, including any narrower ranges within the range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the film or film layer has 0.100 to 0.230 g/100 in²A day, or 0.100 to 0.210 g/100 in²A day, or 0.100 to 0.200 g/100 in²A day, or 0.100 to 0.190 g/100 in²A day, or 0.100 to 0.180 g/100 in²A day, or 0.100 to 0.175 g/100 in²A day, or 0.110 to 0.230 g/100 in²A day, or 0.110 to 0.210 g/100 in²A day, or 0.110 to 0.200 g/100 in²A day, or 0.110 to 0.190 g/100 in²A day, or 0.110 to 0.180 g/100 in²A day, or 0.110 to 0.175 g/100 in²Normalized water vapor transmission rate per day WVTR.

In the embodiments of the present disclosureThe compression molded film or film layer has a density of 0.080 to 0.250 g/100 in²Normalized water vapor transmission rate per day WVTR, including any narrower ranges within the range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, a compression molded film or film layer has 0.100 to 0.230 g/100 in²A day, or 0.100 to 0.210 g/100 in²A day, or 0.100 to 0.200 g/100 in²A day, or 0.100 to 0.190 g/100 in²A day, or 0.100 to 0.180 g/100 in²A day, or 0.100 to 0.175 g/100 in²A day, or 0.110 to 0.230 g/100 in²A day, or 0.110 to 0.210 g/100 in²A day, or 0.110 to 0.200 g/100 in²A day, or 0.110 to 0.190 g/100 in²A day, or 0.110 to 0.180 g/100 in²A day, or 0.110 to 0.175 g/100 in²Normalized water vapor transmission rate per day WVTR.

In embodiments of the present disclosure, the cast film or film layer has 0.080 to 0.250 g/100 in²Normalized water vapor transmission rate per day WVTR, including any narrower ranges within the range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the cast film or film layer has 0.100 to 0.230 g/100 in²A day, or 0.100 to 0.210 g/100 in²A day, or 0.100 to 0.200 g/100 in²A day, or 0.100 to 0.190 g/100 in²A day, or 0.100 to 0.180 g/100 in²A day, or 0.100 to 0.175 g/100 in²A day, or 0.110 to 0.230 g/100 in²A day, or 0.110 to 0.210 g/100 in²A day, or 0.110 to 0.200 g/100 in²A day, or 0.110 to 0.190 g/100 in²A day, or 0.110 to 0.180 g/100 in²A day, or 0.110 to 0.175 g/100 in²Normalized water vapor transmission rate per day WVTR.

In embodiments of the present disclosure, the laminate film or film layer has 0.080 to 0.250 g/100 in²Normalized water vapor transmission rate per day WVTR, including any narrower ranges within the range and any values encompassed by those ranges. For example, in embodiments of the present disclosure, the laminate film or film layer has 0.100 to 0.230 g/100 in²Day, or 0.100 to 0.210 g-100 in²A day, or 0.100 to 0.200 g/100 in²A day, or 0.100 to 0.190 g/100 in²A day, or 0.100 to 0.180 g/100 in²A day, or 0.100 to 0.175 g/100 in²A day, or 0.110 to 0.230 g/100 in²A day, or 0.110 to 0.210 g/100 in²A day, or 0.110 to 0.200 g/100 in²A day, or 0.110 to 0.190 g/100 in²A day, or 0.110 to 0.180 g/100 in²A day, or 0.110 to 0.175 g/100 in²Normalized water vapor transmission rate per day WVTR.

Additional non-limiting details of the disclosure are provided in the following examples. These examples are provided for the purpose of illustrating selected embodiments of the present disclosure, and it is to be understood that the examples presented do not limit the claims presented.

Examples

Universal polymer characterization method

Prior to testing, each sample was conditioned at 23. + -. 2 ℃ and 50. + -. 10% relative humidity for at least 24 hours and then tested at 23. + -. 2 ℃ and 50. + -. 10% relative humidity. Herein, the term "ASTM conditions" refers to a laboratory maintained at 23 ± 2 ℃ and 50 ± 10% relative humidity; and the test specimens to be tested are conditioned in the laboratory for at least 24 hours prior to testing. ASTM refers to the american society for testing and materials.

Density (in g/cm) of polyethylene homopolymer compositions was determined using ASTM D792-13 (11 months and 1 day 2013)³Meter).

Melt index was determined using ASTM D1238 (8 months and 1 day 2013). Melt indices I2, I were measured at 190 ℃ using 2.16 kg, 6.48 kg, 10 kg and 21.6 kg weights, respectively₆、I₁₀And I₂₁. Herein, the term "stress index" or its abbreviation "s.ex." is defined by the following relationship: s.ex. = log (I)₆/I₂) Log (6480/2160); wherein I₆And I₂The melt flow rates were measured at 190 ℃ using 6.48 kg and 2.16 kg loads, respectively.

High temperature gel permeation chromatography with Differential Refractive Index (DRI) detection by using general calibration (e.g., ASTM-D6474-99)Measurement of M by method (GPC)_n、M_wAnd M_z(g/mol). GPC data were obtained using an instrument sold under the trade name "Waters 150 c" with 1,2, 4-trichlorobenzene as the mobile phase at 140 ℃. Samples were prepared by dissolving the polymer in this solvent and run without filtration. Molecular weight is expressed as polyethylene equivalent weight, where the number average molecular weight ("M_n") was 2.9% and the weight average molecular weight (" M_w") had a relative standard deviation of 5.0%. Molecular Weight Distribution (MWD) is the weight average molecular weight divided by the number average molecular weight M_w/M_n. z average molecular weight distribution is M_z/M_n. A polymer sample solution (1 to 2 mg/ml) was prepared by heating the polymer in 1,2, 4-Trichlorobenzene (TCB) and spinning on the wheel for 4 hours in an oven at 150 ℃. An antioxidant, 2, 6-di-tert-butyl-4-methylphenol (BHT), was added to the mixture to stabilize the polymer against oxidative degradation. The BHT concentration was 250 ppm. The sample solutions were chromatographed on a PL 220 high temperature chromatography apparatus equipped with four SHODEX columns (HT 803, HT804, HT805 and HT 806) using TCB as the mobile phase at a flow rate of 1.0 ml/min at 140 ℃ using Differential Refractive Index (DRI) as the concentration detector. BHT was added to the mobile phase at a concentration of 250 ppm to prevent oxidative degradation of these columns. The sample injection volume was 200 ml. The original data were processed with CIRRUS GPC software. The column was calibrated with narrow distribution polystyrene standards. Polystyrene molecular weight was converted to polyethylene molecular weight using the Mark-Houwink equation as described in ASTM standard test method D6474.

The main melting peak (. degree. C.), heat of fusion (J/g) and crystallinity (%), were measured using Differential Scanning Calorimetry (DSC) as follows: the instrument is first calibrated with indium; after calibration, the polymer samples were equilibrated at 0 ℃ and then the temperature was increased to 200 ℃ at a heating rate of 10 ℃/min; the melt was then kept isothermal for 5 minutes at 200 ℃; the melt was then cooled to 0 ℃ at a cooling rate of 10 ℃/min and held at 0 ℃ for 5 minutes; the sample was then heated to 200 ℃ at a heating rate of 10 ℃/min. DSC Tm, heat of fusion, and crystallinity are reported from the second heating cycle.

The unsaturation in the polyethylene homopolymer composition was determined by Fourier transform Infrared Spectroscopy (FTIR) according to ASTM D3124-98.

Hexane extractables were determined according to ASTM D5227.

Shear viscosity was measured using a Kayeness WinKARS capillary rheometer (model # D5052M-115). For shear viscosity at lower shear rates, a die having a die diameter of 0.06 inch and an L/D ratio of 20 and an entrance angle of 180 degrees was used. For shear viscosity at higher shear rates, a die having a die diameter of 0.012 inches and an L/D ratio of 20 was used.

As the term is used in this disclosure, the shear viscosity ratio is defined as: eta at 240 ℃₁₀₀/η₁₀₀₀₀₀. The processability index is defined as 100/eta₁₀₀₀₀₀。η₁₀₀Is at 100 s^-1Shear viscosity and η of the melt at a shear rate of₁₀₀₀₀₀Is measured at 100000 s at 240 DEG C^-1Melt shear viscosity at a shear rate of (a).

As used herein, "processability index" is defined as: processability index = 100/η (10)⁵ s^-1240 ℃ C.); wherein eta is at 10⁵Shear viscosity at 240 ℃ measured at 1/s.

Dynamic mechanical analysis of the compression moulded samples was performed with a rheometer, either Rheometrics Dynamic Spectrometers (RDS-II) or Rheometrics SR5 or ATS Strestech using a 25 mm diameter conical plate geometry at 190 ℃ under a nitrogen atmosphere. Oscillatory shear experiments were performed at frequencies of 0.05 to 100 rad/s over the linear viscoelastic range of strain (10% strain). Values of storage modulus (G'), loss modulus (G "), complex modulus (G ″) and complex viscosity (η ″) were obtained as a function of frequency. The same rheological data can also be obtained using a 25 mm diameter parallel plate geometry at 190 ° under a nitrogen atmosphere. Estimating zero shear viscosity using Ellis model, i.e. η (ω) = η₀/(1 + τ/τ_1/2)^α-1Wherein eta₀Is a zero shear viscosity. Tau is_1/2Is η = η₀Shear stress value at/2, and α is one of the adjustable parameters. Assuming that the Cox-Merz law applies to the present disclosure. The SHI (1,100) values were calculated according to the methods described in WO 2006/048253 and WO 2006/048254.

DRI is the "road rheology index" and is defined by the following equation:DRI = [365000(τ₀/η₀)−1]10; wherein tau is₀Is the characteristic relaxation time of the polyethylene, and eta₀Is the zero shear viscosity of the material. DRI is calculated by least squares fitting of the rheological curve (dynamic complex viscosity vs. applied frequency, e.g. 0.01-100 rads/s) as described in U.S. Pat. No. 6,114,486 in the following generalized Kerns equation, i.e. eta (ω) = eta =₀/[1+(ωτ₀)ⁿ](ii) a Where n is the power law exponent of the material and η (ω) and ω are the measured complex viscosity and applied frequency data, respectively. Zero shear viscosity η used when determining DRI₀The Ellis model was used instead of the Cross model for the estimation.

The crossover frequency is a frequency at which the curves of the storage modulus (G ') and the loss modulus (G ") cross each other, and G' @ G" =500Pa is a storage modulus at which the loss modulus (G ") is 500 Pa.

Plaques molded from the polyethylene homopolymer composition were tested according to the following ASTM methods: environmental Stress Crack Resistance (ESCR) of bent test bars at 50 ℃ under 100% IGEPAL under condition B, ASTM D1693; notched izod impact properties, ASTM D256; flexural properties, ASTM D790; tensile properties, ASTM D638; vicat softening point, ASTM D1525; heat distortion temperature, ASTM D648.

An example of a polyethylene homopolymer composition is prepared in a two-reactor solution polymerization process, where the contents of the first reactor flow into the second reactor. This series "dual reactor" process produces an "in situ" polyethylene blend (i.e., a polyethylene homopolymer composition). Note that when a series reactor configuration is employed, unreacted ethylene monomer present in the first reactor will flow into the downstream second reactor for further polymerization.

In the inventive examples, no comonomer was fed to either the first or second reactor and ethylene homopolymer was formed in each reactor. With each reactor being sufficiently agitated to provide adequate mixing of the componentsAnd (4) conditions. The first reactor had a volume of 12 litres and the second reactor had a volume of 22 litres. These are pilot scale. The first reactor is operated at a pressure of 10500 to 35000 kPa and the second reactor is operated at a lower pressure to facilitate continuous flow from the first reactor to the second reactor. The solvent used was methylpentane. The process is operated with continuous feed flow. The catalyst used in the two reactor solution process runs was a phosphinimine catalyst, which was a catalyst having a phosphinimine ligand ((t-butyl)₃P = N), a cyclopentadienyl (cyclopentadienide) ligand (Cp) and two activatable ligands (chloro ligands; note that: the "activatable ligand") is removed by electrophilic extraction, for example using a cocatalyst or activator, to produce an active metal center. Boron-based cocatalyst (Ph)₃CB(C₆F₅)₄) Is used in an approximately stoichiometric amount relative to the titanium complex. About 40:1 Al: Ti contained commercially available Methylaluminoxane (MAO) as a scavenger. In addition, 2, 6-di-tert-butylhydroxy-4-ethylbenzene was added at an Al: OH ratio of about 0.5:1 to scavenge free trimethylaluminum from MAO. The polymerization conditions used to prepare the polyethylene homopolymer compositions of the present invention are provided in table 1.

As described above, the polyethylene homopolymer compositions of examples 1 and 2 of this invention were prepared in a two reactor solution process using a single site phosphinimine catalyst. Each having a weight average molecular weight M of less than about 65,000 g/mol_wAnd a melt index I of greater than 10 g/10min₂。

Comparative polyethylene homopolymer compositions (examples 3 and 4) nucleated with HPN20E (which may be available from Milliken Chemical) in the same manner as examples 1 and 2 and to the same amount (see below) were prepared using a phosphinimine catalyst in a two reactor solution polymerization process in substantially the same manner as set forth in U.S. patent publication nos. 2008/0118749 and 2015/0203671 (both of which are incorporated herein in their entirety).

The comparative polyethylene homopolymer compositions of examples 3 and 4 each have a melt index I of less than 10 g/10min₂And a weight average molecular weight M greater than about 65,000 g/mol_w。

As can be seen in FIG. 1, inventive examples 1 and 2 have a bimodal molecular weight distribution or profile in the GPC analysis, as do comparative examples 3 and 4.

The properties of the inventive and comparative polyethylene homopolymer compositions, which were not nucleated, are provided in table 2. The nucleated inventive resins (which are identified by the symbol "") were prepared in the following manner. First, HYPERFORM from Milliken Chemical was prepared^®4% (by weight) masterbatch of HPN-20E nucleating agent. The masterbatch also contained 1% by weight of DHT-4V (aluminum magnesium carbonate hydroxide) from Kisuma Chemicals. The base resin was then melt blended with a nucleating agent masterbatch using a Coperion ZSK 26 co-rotating screw extruder having an L/D of 32:1 to give a polyethylene homopolymer composition having a presence of 1200 parts per million (ppm) of HYPERFORM PN-20E nucleating agent (based on the weight of the polyethylene homopolymer composition). The extruder was equipped with an underwater pelletizer and a Gala rotary dryer. The materials were co-fed into the extruder using a gravimetric feeder to achieve the desired nucleator level. The blend was compounded using a screw speed of 200 rpm at an output speed of 15-20 kg/hour and a melt temperature of 225-230 ℃.

Calculated properties of the first ethylene homopolymer and the second ethylene homopolymer present in each of the inventive and comparative homopolymer compositions are provided in table 3 (see "polymerization reactor modeling" below for methods of calculating these properties).

The properties of the pressed sheets prepared from the non-nucleated and the nucleated polyethylene homopolymer compositions of the present invention as well as the comparative compositions are provided in table 4.

Polymerization reactor modeling

For multicomponent (or bimodal resin) polyethylene polymers with very low comonomer content, it can be difficult to reliably estimate the short chain branching of each polymer component (and subsequently the polyethylene resin density by combining other information) by mathematical deconvolution of GPC-FTIR data (as done in, for example, U.S. patent No. 8,022,143). Alternatively, detailed descriptions are used hereinThe polymerization reactor modeling described in U.S. Pat. No. 9,074,082 calculates M for the first and second ethylene homopolymers_w、M_n、M_z、M_w/M_nHowever, due to the absence of comonomer in the feed, the first and second ethylene homopolymers are set to zero except for short chain branching per one thousand carbons (SCB/1000C) for each of the first and second polymer components. The polymerization reactor model or simulation employs input conditions for actual pilot scale (pilot scale) operating conditions (reference to the relevant reactor modeling method, see in A. Hamielec, J. MacGregor and A. Penlidis atComprehensive Polymer Science and Supplements"Copolymerization" and J.B.P. Soares and A.E Hamielec in Vol.3, Chapter.2, p.17, Elsevier, 1996Polymer Reaction Engineering, 4(2&3) On page 153, 1996, "Copolymerization of Olefins in a Series of contacts Stired-Tank-Reactors using heterogenous Olefins Ziegler-Natta and Metallocene catalysts. I. General Dynamic Mathemacial Model").

The model takes multiple streams of active species (e.g., catalyst, monomers such as ethylene, hydrogen, and solvent) input into each reactor, temperature (in each reactor), and ethylene conversion (in each reactor), and calculates the properties of the polymer (the polymer produced in each reactor, i.e., the first and second ethylene homopolymers) using a terminal kinetic model for a series-connected continuous stirred reactor (CSTR). The "terminal kinetics model" assumes that the kinetics depend on the monomer (e.g. ethylene) units in the polymer chain where the active catalyst sites are located (see a. Hamielec, j. MacGregor and a. Penlidis atComprehensive Polymer Science and Supplements"Copolymerization" in volume 3, chapter 2, page 17, Elsevier, 1996. In the model, it is assumed that the homopolymer chains have a considerable molecular weight to ensure that the statistics of monomer unit insertions at the active catalyst centers are valid and that the monomer consumption in routes other than growth is negligible. This is called the "long chain" approximation.

The terminal kinetic model of polymerization includes reaction rate equations for activation, initiation, propagation, chain transfer, and inactivation pathways. The model explains the steady state conservation equations (e.g., total mass balance and heat balance) for reactive fluids containing the active species identified above.

The overall mass balance for a conventional CSTR with a given number of inlets and outlets is provided by:

whereinRepresents the mass flow rate of the individual streams, where the subscript i denotes the inlet and outlet streams.

Equation (1) can be further developed to show individual species and reactions:

whereinM _iIs the average molar amount of fluid inlet or outlet (i),x _ijis in logisticsiOf the classjMass fraction of (p) ()_mixIs the molar density of the reactor mixture,Vis the volume of the reactor, and is,R _jis a kind ofjHas a reaction rate in kmol/m³s。

For the adiabatic reactor, the total heat balance is solved and given by:

whereinIs the mass flow rate of stream i (inlet or outlet),is the enthalpy difference of the stream i vs. reference state,is the amount of heat released by one or more reactions,Vis the volume of the reactor, and is,is the input of work (i.e. the stirrer),is the heat input/loss.

To solve the equations of the kinetic model (e.g., growth rate, heat balance, and mass balance), the catalyst concentration input to each reactor was adjusted to match the experimentally determined ethylene conversion and reactor temperature values.

H fed to each reactor₂The concentration can also be adjusted so that the calculated molecular weight distribution of the polymer produced via the two reactors (and thus the molecular weight of the polymer produced in each reactor) matches the molecular weight distribution observed experimentally.

The Degree of Polymerization (DPN) of the homopolymerization is provided by the ratio of the rate of chain extension reaction to the rate of chain transfer/termination reaction:

whereinIs the growth rate constant of the monomer 1,is the molar concentration of monomer 1 (ethylene) in the reactor,by chain transfer to monomersThe rate constant is terminated and the rate of the,is the rate constant for spontaneous chain termination for a chain ending with monomer 1,is the rate constant for chain termination by hydrogen for a chain ending with monomer 1.

Number average molecular weight (M) of the Polymer_n) Derived from the degree of polymerization and the molecular weight of the monomer unit. The molecular weight distribution was determined for the polymer formed in each reactor from the number average molecular weight of the polymer in each reactor and assuming a Flory distribution for the single site catalyst:

whereinAndis the weight fraction of polymer having a chain length n.

The Flory distribution can be converted into a common log-proportional GPC trace by applying the following formula:

whereinIs a chain length n: (Where 28 is a radical corresponding to C₂H₄Molecular weight of polymer segment of unit), and DPN is the poly calculated by equation (4)Degree of contact. M of Polymer produced in each reactor by Flory model_wAnd M_zComprises the following steps: m_w = 2 × M_nAnd M_z = 1.5 × M_w。

The overall molecular weight distribution of the two reactors is simply the sum of the molecular weight distributions of the polymers produced in each reactor, and where each Flory distribution is multiplied by the weight fraction of polymer produced in each reactor:

whereinIs a function of the overall molecular weight distribution,andis the weight fraction of polymer produced in each reactor,andis the average chain length of the polymer produced in each reactor (i.e.). The weight fraction of material produced in each reactor is determined by knowing the mass flow rate of monomer entering each reactor and knowing the monomer conversion in each reactor.

The moment of the overall molecular weight distribution (or the molecular weight distribution of the polymer produced in each reactor) can be calculated using equations 8a, 8b and 8c (the Flory model is assumed above, but the general formula below applies to other model distributions as well):

。

for the polymer obtained in each reactor, the key resin parameter obtained from the kinetic model described above is the molecular weight M_n、M_wAnd M_zMolecular weight distribution M_w/M_nAnd M_z/M_wThe branching frequency (in this case 0). After this information is learned, a component (or composition) density model and a component (or composition) melt index I are used according to the following equation₂A model, said equation being empirically determined, whereby the density and melt index I, respectively, of the first and second ethylene homopolymers are calculated₂：

Density:

where BF is the branching frequency (it is to be noted here that, for homopolymers, BF = 0 is suitable),

melt index I₂（MI）：

Thus, the above model was used to estimate the branching frequency, weight fraction (or wt%), melt index and density of the polyethylene composition components formed in each of reactors 1 and 2 (i.e., the first and second ethylene homopolymers).

TABLE 1

Reactor conditions

Example numbering	Inv. 1	Inv. 2
			Reactor 1
Ethylene (kg/h)	36	36
			Octene (kg/h)	0	0
Hydrogen (g/h)	1.1	1.4
			Solvent (kg/h)	307	307
Reactor feed inlet temperature (. degree. C.)	35	35
			Reactor temperature (. degree.C.)	162.9	163
Titanium catalyst (ppm)	0.0174	0.0140
			Reactor 2
Ethylene (kg/h)	36.1	36
			Octene (kg/h)	0	0
Hydrogen (g/h)	27	28
			Solvent (kg/h)	170.9	170.9
Reactor feed inlet temperature (. degree. C.)	35	35
			Reactor temperature (. degree.C.)	199.9	190.2
Titanium catalyst (ppm)	0.0547	0.0583

TABLE 2

Properties of the resin

Example numbering	Inv. 1	Inv. 1*	Inv. 2	Inv. 2*	Comp. 3	Comp. 4
							Nucleating agent	Is free of	HPN20E	Is free of	HPN20E	HPN20E	HPN20E
Density (g/cm)³)	0.9662	0.9684	0.9675	0.9698	0.966	0.968
							Density (g/cm) of base resin³)		0.9662		0.9675
Density increase after nucleation		0.0022		0.0023
							Melt index I₂(g/10 min), base resin	12.2		20.4		1.2	6
Melt index I₆(g/10 min)	49.2		81.6		5.49	24.5
							Melt index I₁₀(g/10 min)	86.9		155		11	45.5
Melt index I₂₁(g/10 min)	403		661		69	194
							Melt flow ratio (I)₂₁/I₂)	33.2		32.5		57	33
Stress index	1.27		1.26		1.38	1.27
							Melt flow ratio (I)₁₀/I₂)	7.64		7.62		9.4	7.59
Rheological Properties
							10⁵ s^-1Shear viscosity (. eta.) (240 ℃, Pa-s)	4.4		4.0		5.4	5.2
10⁵ s^-1The processing property index is 100/eta (240 ℃), and	22.7		25		18.5	19.2
							shear viscosity ratio eta₁₀₀/ η₁₀₀₀₀₀(240℃)	62		42.6		185	87
Zero shear viscosity-190 ℃ (Pa-s)	769.5		413.54
							DRI	0.262		0.24
G'@G"=500Pa	21.1		15
							DSC
Major melting Peak (. degree. C.)	131.69	133.93	131.77	134.39	133.74	133.80
							Heat of fusion (J/g)	253	267.2	250.2	254.9	244.74	244.80
Degree of crystallinity (%)	87.23	92.13	86.29	87.89	84.39	84.41
							GPC
M_n	6776		7613		12764	14377
							M_w	51377		45924		96923	69182
M_z	128954		112444		280629	163561
							Polydispersity index (M_w/M_n)	7.58		6.03		7.59	4.81
Hexane extractables (%) -plates	0.53		0.57		0.21	0.53

TABLE 3

Properties of Components of polyethylene homopolymer composition

Example numbering	Inv. 1	Inv. 2	Comp. 3	Comp. 4
					Density (g/cm3)	0.9662	0.9675	0.966	0.968
I2 (g/10min.)	12.2	20.4	1.2	6
					Stress index	1.27	1.26	1.38	1.27
MFR (I21/I2)	33.2	32.5	57	33
					Mw/Mn	7.58	6.03	7.59	4.81
A first ethylene homopolymer
					Weight fraction of	0.536	0.535	0.47	0.515
Mw	108323	92663	177980	115059
					I2 (g/10min)	0.64	1.18	0.09	0.51
SCB1/1000C	0	0	0	0
					Density, d1 (g/cm3)	0.9506	0.952	0.9464	0.95
Second ethylene homopolymer
					Weight fraction of	0.464	0.465	0.53	0.485
Mw	8685	8620	13394	13105
					I2 (g/10min.)	12306	12674	2264.0	2465.0
SCB2/1000C	0	0	0	0
					Density, d2 (g/cm3)	0.9724	0.9725	0.9685	0.9687
Estimate (d2-d1), g/cm3	0.0218	0.0205	0.0221	0.0187

TABLE 4

Nature of the board

Example numbering	Inv. 1	Inv. 1*	Inv. 2	Inv. 2*	Comp. 3	Comp. 4
							Tensile Properties (sheet)
Elongation at yield (%)	7	6	4	4		7
							Deviation in yield elongation (%)	0.1	0.7	0.1	0.5		0
Yield strength (MPa)	33.5	34.8	32.9	34.6		34.2
							Deviation of yield strength (MPa)	0.1	0.2	0.9	1		0.4
Ultimate elongation (%)	10	6	4	4		7
							Deviation in ultimate elongation (%)	0.1	0.7	0.1	0.5		0
Ultimate strength (MPa)	32.3	34.8	32.9	34.6		34.2
							Ultimate strength deviation (MPa)	1	0.2	0.9	1		0.4
Secant modulus 1% (MPa)	1751.1	1974	1870.1	1997	1792	1996
							Secant modulus 1% (MPa) deviation	69.6	31	34	61	165	109
Secant modulus 2% (MPa)	1280.8	1391	1338	1435	1233	1365
							Secant modulus 2% (MPa) deviation	17.9	15	11	34	33	29
Young's modulus (MPa)	2543		2790.1
							Deviation of Young's modulus (MPa)	477.1		558.4
Flexural Property (plate)
							Modulus of bending secant 1% (MPa)	1853	1994	1882	2241	1856	1940
Deflection of 1% (MPa) of modulus of bending secant	62	126	38	94	79	57
							Modulus of bending secant 2% (MPa)	1535	1652	1549	1817	1553	1580
Deflection of bending secant modulus of 2% (MPa)	42	87	15	64	29	40
							Modulus of bending tangent (MPa)	2136	2276	2190	2587	2167	2309
Deflection of flexural tangent modulus (MPa)	94	175	111	147	191	147
							Bending strength (MPa)	48.7	51.6	49.5	54.8	48.5	49.1
Deflection of bending strength (MPa)	0.6	1.6	0.6	1.5	0.4	1.3
							Impact Property (plate)
Cantilever beam impact (ft-lb/in)	0.5		0.4		2	1.4
							Environmental stress cracking resistance
ESCR Condition B (hours) at 100% CO-630	0		0		< 16	4
							Miscellaneous items
VICAT Soft Pt. (. degree. C.) -board	125		123.6		128.4	127.4
							Heat distortion temperature (. degree. C.) @66 PSI	80.7		85.4		77.2	76.2

Method for producing compression molding film

A compression film was prepared from the inventive and comparative polyethylene homopolymer compositions using a laboratory scale compression press, Wabash G304, from Wabash MPI. A metal frame of the desired size and thickness is filled with a measured amount of resin (e.g., pellets of a polyethylene homopolymer composition) and sandwiched between two polished metal plates. The amount of polymer used was found to be sufficient to achieve the desired film thickness. A polyester sheet (Mylar) was used on the metal backing form to prevent the resin from adhering to the metal plate. The assembly with resin is loaded into a compression press and preheated at 200 ℃ for 5 minutes at a low pressure (e.g., 2 tons or 4400 pounds per square foot). The platens are closed and high pressure (e.g., 28 tons per square foot or 61670 pounds) is applied for an additional five minutes. Subsequently, the press was cooled to about 45 ℃ at a rate of about 15 ℃ per minute. After the cycle is complete, the frame assembly is removed, disassembled and the film (or plate) is separated from the frame. Subsequent testing was performed at least 48 hours after compression molding was performed.

Determination of Oxygen Transmission Rate (OTR) of compression Molding film Using masking method

The Oxygen Transmission Rate (OTR) of the pressure tested plastic films was measured using a version of ASTM F1249-90 using OX-TRAN 2/20 instruments manufactured by MOCON Inc, Minneapolis, Minnesota, USA. The instrument has two test units (a and B) and each membrane sample is analyzed twice. The reported OTR results are the average of the results of the two test units (a and B). The test was carried out at a temperature of 23 ℃ and a relative humidity of 0%. Typically, the area of the film sample used for the OTR test is 100 cm². However, for barrier testing of films with limited sample numbers, an aluminum foil mask was used to reduce the test area. When the mask was used, the test area was reduced to 5cm². The foil mask has an adhesive on the side to which the sample is attached. A second foil is then attached to the first foil to ensure a leak-free seal. The carrier gas used was 2% hydrogen, the balance nitrogen, and the test gas was ultra-high purity oxygen. The OTR of the compression-molded films was measured at the corresponding film thickness obtained by the compression-molding method. However, to compare different samples, the resulting OTR values (in cm) have been used³/100in²In days) to a film thickness value of 1 mil.

Determination of Water Vapor Transmission Rate (WVTR) of compression Molding film Using mask method

The Water Vapor Transmission Rate (WVTR) of the plastic films tested was measured using a version of ASTM D3985 using PERMATRAN # 3/34 instruments manufactured by MOCON Inc, Minneapolis, Minnesota, USA. The instrument has two test units (a and B) and each membrane sample is analyzed twice. The reported WVTR results are the average of the results of the two test units (a and B). The test was carried out at a temperature of 37.8 ℃ and a relative humidity of 100%. Typically, the area of the film sample used for the WVTR test is 50 cm². However, for barrier testing of films with limited sample numbers, an aluminum foil mask was used to reduce the test area. When the mask was used, the test area was reduced to 5cm². The foil mask has an adhesive on the side to which the sample is attached. A second foil is then attached to the first foil to ensure a leak-free seal. The carrier gas used was ultra-high purity nitrogen and the test gas was water vapor at 100% relative humidity. The WVTR of the compression-molded films was measured at the corresponding film thickness obtained by the compression molding method. However, to compare different samples, the resulting WVTR values (in grams/100 in) have been compared²In days) to a film thickness value of 1 mil.

The barrier properties (OTR and WVTR) of compression molded films made from the comparative and inventive polyethylene compositions are provided in table 5.

TABLE 5

OTR and WVTR Properties of compression moulded films

Example numbering	Inv. 1	Inv. 1*	Inv. 2	Inv. 2*	Comp. 3	Comp. 4
							WVTR-thickness (mel)	2.5	2.2	2.4	1.5	2.7	2.4
WVTR g/100 IN²Day (relative humidity = 100%, 37.8 ℃, atm)	0.1036	0.0773	0.0949	0.0865	0.0478	0.0617
							WVTR，g/100 IN²Day-normalized thickness (1 mil)	0.2590	0.1701	0.2278	0.1298	0.1291	0.1481
OTR-thickness (mel)	2.5	2.2	2.4	1.5	2.7	2.4
							OTR，CC/100 IN²Day (relative humidity = 0%, 23 ℃, atm)	31.93	29.4	31.22	28.79	21.14	28.45
OTR，CC/100 IN²Day-normalized thickness (1 mil)	79.83	64.68	74.93	43.19	57.08	68.28

As can be seen from table 5 and the data in fig. 2 and 3, films made from the nucleated compositions of the present invention (examples 1 and 2) had OTR and WVTR values comparable to films made from the comparative compositions when similarly nucleated (examples 3 and 4), even though the inventive resins had higher melt indices (i.e., lower molecular weights). In fact, the films produced in example 2 of the invention have superior (lower) OTR values compared to the films produced in the comparative compositions (examples 3 and 4). A higher melt index can be used for cast film production as it contributes to processability and line time.

Method for producing a seal by injection moulding

The inventive homopolymer compositions in nucleated mode, as well as the comparative resins, were made into seals using an injection molding process. A Sumitomo injection molding machine and a 2.15 gram PCO (plastic only seal) 1881 Carbonated Soft Drink (CSD) seal mold were used to prepare the seals herein. A Sumitomo injection molding machine (model SE75EV C250M) with a screw diameter of 28 mm was used. A 4-cavity CSD seal mold was made from Z-molds (austria). A 2.15 gram PCO 1881 CSD seal design was developed by Universal Closures ltd. (uk). During the seal manufacturing process, four seal parameters were measured-the diameter of the cap top, the hole seal diameter, the tamper band diameter, and the overall end cap height-and were ensured to be within quality control specifications.

Seal dimensions were determined using the International Society of Beverage Technologies (ISBT) voluntary standard test method. The test used involved selecting a mold cavity and measuring at least 5 seals made from that particular cavity. Measurements of at least 14 dimensions were obtained from seals aged at least 1 week from the date of production. Seal sizing was performed using a Vision Engineering, Swift Duo dual optical and video measurement system. All measurements were performed using 10 × magnification and using METLOGIX M video measurement System software (see METLOGIX M)³: Digital Comparator Field of View Software, User’s Guide）。

The seal was formed by injection molding and the injection molding processing conditions are given in table 6.

TABLE 6

Conditions of injection molding

Example numbering	Inv. 1*	Inv. 2*	Comp. 3	Comp. 4
					And seal No.	1	2	3	4
Additive (color)&Formulations (I)	Natural substance (such as natural gas)	Natural substance (such as natural gas)	Red wine	Red wine
					Part weight (g)	8.6	8.6	8.6	8.6
Injection speed (mm/s)	45	45	125	125
					Cycle time(s)	4.09	4.34	4.12	3.65
Filling time(s)	0.639	0.617	0.245	0.245
					Time of dosing(s)	1.814	1.78	1.99	1.82
Minimum buffer (mm)	9.76	9.76	9.93	9.93
					Fill Peak pressure (psi)	8660	7087	13829	14309
Full Peak pressure (psi)	8670	7095	13829	14309
					Hold end position (mm)	12.39	11.53	11.65	11.44
Dwell pressure set point (Psi)	2050	2000	4350	5700
					Closing die force (ton)	20	20	19.78	19.70
Filling starting point position (mm)	38.49	37.51	40.43	40.43
					Metering backpressure (psi)	833	830	822	833
Pressure maintaining (psi)	8662	7038	13752	14222
					Filling time 1(s)	0.64	0.616	0.248	0.248
Temperature zone 1 (. degree. C.)	180	180	210	180
					Temperature zone 2 (. degree. C.)	185	185	215	185
Temperature zone 3 (. degree. C.)	190	190	220	190
					Temperature zone 4 (. degree. C.)	200	200	230	200
Temperature zone 5 (. degree. C.)	200	200	230	200
					Mold temperature Steady State (. degree. C.)	10	10	10	10

Oxygen Transmission Rate (OTR) of injection molded seal

To measure the Oxygen Transmission Rate Through the seal, ASTM D3985 (Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor) was modified as follows.

The tamper evident band of the seal is first removed. Next, the bottom edge of the seal was lightly sanded (for better adhesion with epoxy) and then the seal was epoxy bonded (using devicon^®Two-component epoxy) onto test panels to cover the outlet tube (of purge gas) and for introducing N₂Of the vessel. The epoxy resin was allowed to dry overnight. One of the two gas tubes projecting into the interior of the seal carries the input nitrogen gas (nitrogen feed line) flowing into the interior of the seal, while the other carries the purge gas leaving the interior of the seal and entering the detector(e.g., nitrogen + permeate from the atmosphere surrounding the seal). If oxygen present in the atmosphere penetrates the seal wall, it will be in the N that leaves the interior of the seal as a purge gas₂Is detected as a component. Connecting the plate/seal/tubing set to an OX-TRAN low range instrument (PERMATRAN-C)^®Model 2/21 MD), in which the test panels were placed in an environmental chamber controlled at a temperature of 23 ℃. Baseline measurements for the detection of atmospheric oxygen were also made using impermeable aluminum foil (in parallel with the seal) to compare permeability together. The oxygen transmission rate of the seal is in the form of the average oxygen transmission rate in cm³Seal/day is reported in units.

The oxygen barrier properties of injection molded seals made from comparative and inventive polyethylene homopolymer compositions, both of which had been nucleated, are provided in table 7.

TABLE 7

Example numbering	Seal numbering	Average OTR (cm)³Sealing member/sky)	Test gas
				Inv. 1*	1	0.0012	Ambient air (20.9% oxygen)
Inv. 2*	2	0.0009	Ambient air (20.9% oxygen)
				Comp. 3	5	0.0012	Ambient air (20.9% oxygen)
Comp. 4	6	0.0017	Ambient air (20.9% oxygen)

As can be seen from the data in table 7 and fig. 4, the OTR values for seals made from the nucleated inventive resin are comparable or better than those for seals made from similarly nucleated comparative resins, even though the inventive resin has a higher melt index (i.e., lower molecular weight). A higher melt index can be used for the production of caps and seals because it contributes to line cycle time, especially during the production of injection molded seals. In addition, relatively low OTR values provide advantages in the manufacture of articles (e.g., as caps or seals for bottles, containers, and the like, or fittings for bags, and the like), which can benefit from good barrier properties.

INDUSTRIAL APPLICABILITY

The present disclosure provides a polyethylene homopolymer composition having good barrier properties, and which is useful for making films or molded articles, such as seals for bottles.

36页详细技术资料下载

Polyethylene homopolymer compositions with good barrier properties

相关技术

网友询问留言