阅读说明：本技术 双峰或多峰聚乙烯组合物 (Bimodal or multimodal polyethylene composition ) 是由 吉里什·苏雷什·加尔加利 拉纳·库代 芭芭拉·曼德尔 约翰·杰米逊 于 2019-03-21 设计创作，主要内容包括：本发明涉及一种聚合物组合物,其包含双峰或多峰乙烯聚合物(P)和成核剂,所述成核剂是环状烷烃的二羧酸。此外,本发明涉及一种包含所述聚合物组合物的制品以及成核剂用于降低聚乙烯薄膜的水蒸气透过率和氧气透过率的用途,所述成核剂是环状烷烃的二羧酸。(The present invention relates to a polymer composition comprising a bimodal or multimodal ethylene polymer (P) and a nucleating agent which is a dicarboxylic acid of a cyclic alkane. Furthermore, the present invention relates to an article comprising said polymer composition and to the use of a nucleating agent, which is a dicarboxylic acid of a cyclic alkane, for reducing the water vapour transmission rate and the oxygen transmission rate of a polyethylene film.)

1. A polymer composition comprising

c) Bimodal or multimodal ethylene polymer (P) having a Molecular Weight Distribution (MWD) of less than 5.0 and a Heterogeneity Factor (HF) in the range of 30 to 120 as determined by Cross-fractionation chromatography (CFC) and in the range of 910 to 935kg/m³A density within the range of (a);

d) a compound of the following formula (I)

Wherein

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉And R₁₀Each independently selected from hydrogen and C₁To C₁₀Hydrocarbyl, hydroxy, C₁To C₁₀Alkoxy radical, C₁To C₁₀Alkyleneoxy, amine, C₁To C₁₀Alkylamine, F, Cl, Br, I and phenyl;

wherein R is located on adjacent carbon atoms₃To R₁₀Two of which can be fused to form a ring structure;

m is selected from the group consisting of: calcium, strontium, lithium, zinc, magnesium, and monobasic aluminum;

n is 1 or 2;

z is 1 or 2;

the sum of n + z is 3.

2. The polymer composition according to any of the preceding claims, wherein the bimodal or multimodal ethylene polymer (P) is produced using a single site catalyst.

3. The polymer composition according to any of the preceding claims, wherein the amount of the compound according to formula (I) is in the range of 50 to 10000ppm, based on the total amount of the polymer composition.

4. The polymer composition according to any of the preceding claims, wherein in formula (I), R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉And R₁₀Each independently selected from hydrogen and C₁To C₁₀A hydrocarbyl group.

5. The polymer composition according to any of the preceding claims, wherein the bimodal or multimodal ethylene polymer (P) has a molecular weight of from 0.25 to 20g/10min according to ISO1133MFR determined at 190 ℃ and under a load of 2.16kg₂。

6. The polymer composition according to any of claims 1 to 5, wherein the ratio of [ the amount of comonomer present (mole%) in ethylene polymer component (A) ] to [ the total amount of comonomer (mole%) of the final bimodal or multimodal ethylene polymer (P) ] is from 0.2 to 0.6, preferably from 0.24 to 0.5, more preferably the ethylene polymer component (A) has a lower amount of comonomer (mole%) than the ethylene polymer component (B).

7. The polymer composition according to any of claims 1 to 6, wherein the ethylene polymer component (A) has an MFR determined according to ISO1133 at 190 ℃ and under a load of 2.16kg of from 1 to 50g/10min, preferably from 1 to 40g/10min, more preferably from 1 to 30g/10min₂。

8. The polymer composition of any of the preceding claims, wherein the polymer composition when formed into a monolayer film having a thickness of 40 μ ι η is further characterized by at least one of the following features:

x) a tensile modulus in the machine direction determined according to ASTM D882 of 180 to 300 MPa;

xi) a tear strength in the machine direction of at least 4.5N determined according to ISO 6383-2;

xii) a dart impact strength of at least 900g, determined according to ISO7765-1: 2004;

xiii) a haze of 15% or less as measured according to ASTM D1003;

xiv) a gloss measured according to ISO 2813 of at least 75% at 60 ℃;

xv) oxygen transmission rate of 4000 ml/(m) determined according to ASTM D3985 using the pressure sensor method (Standard conditions 23 ℃, 50% humidity)²Day) or less;

xvi) Water vapor Transmission Rate of 10.0 g/(m) determined according to ASTM F1249²Day) or less;

xvii) a Seal Initiation Temperature (SIT) at 5N of 75 ℃ or more measured according to ASTM F2029 and ASTM F88 with a seal width of 25mm, a seal pressure of 43.5psi and a dwell time of 1s using a film sample having a thickness of 40 μm; and/or

xviii) Using a film sample having a thickness of 40 μm, a sealing pressure of 0.25N/mm was determined according to ASTM F1921 (inside-inside)²And a hot-tack temperature at 1N of 65 ℃ or higher, the hot-tack temperature being measured at a dwell/seal time of 1s, a delay time of 100ms and a test/peel speed of 198.8 mm/s.

9. An article comprising, preferably consisting of, the polymer composition according to any of the preceding claims.

10. The article according to claim 9, which is a film comprising one or more layers, wherein at least one of said layers comprises, preferably consists of, the polymer composition according to any one of claims 1 to 7.

11. The article of claim 10 which is a film, wherein the film is a monolayer film.

12. A compound of the following formula (I)

Wherein

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉And R₁₀Each independently selected from hydrogen and C₁To C₁₀Hydrocarbyl, hydroxy, C₁To C₁₀Alkoxy radical, C₁To C₁₀Alkyleneoxy, amine, C₁To C₁₀Alkylamine, F, Cl, Br, I and phenyl;

wherein are located on adjacent carbon atomsR of (A) to (B)₃To R₁₀Two of which can be fused to form a cyclic hydrocarbyl structure;

m is selected from the group consisting of: calcium, strontium, lithium, zinc, magnesium, and monobasic aluminum;

n is 1 or 2;

z is 1 or 2;

the sum of n + z is 3,

use, optionally in combination with a fatty acid salt, for at least one of the following, compared to the same film without the compound according to formula (I) and the optional fatty acid salt:

vi) reducing the haze of the layer of the film by at least 25%;

vii) increasing the gloss of a layer of the film by at least 50% at 60 ℃;

viii) increasing the tensile modulus of a layer of the film in the machine direction by at least 15%;

ix) reducing the Water Vapour Transmission Rate (WVTR) of a layer of the film by at least 10%; and/or

x) reduces the Oxygen Transmission Rate (OTR) of a layer of the film by at least 25%,

the layer comprises a bimodal or multimodal ethylene polymer (P) having a Molecular Weight Distribution (MWD) of less than 5.0 and a Heterogeneity Factor (HF) determined by cross-fractionation chromatography (CFC) in the range of 30 to 120, wherein the film optionally comprises one or more additional layers.

13. Use of a polymer composition according to any one of claims 1 to 8 for providing a film that maintains an oxygen induction time within 10% of the oxygen induction time of the same polymer composition without the compound according to formula (I) and optionally the fatty acid salt.

14. Use according to any of the preceding claims 12 or 13, wherein the amount of bimodal or multimodal ethylene polymer (P) is at least 80 wt. -%, based on the layers of the film.

15. Use of a polymer composition to provide a shaped article having a haze value of 15.0% or less as determined according to ASTM D1003, the polymer composition comprising:

c) a bimodal or multimodal ethylene polymer;

d) a compound of the following formula (I)

Wherein

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉And R₁₀Each independently selected from hydrogen and C₁To C₁₀Hydrocarbyl, hydroxy, C₁To C₁₀Alkoxy radical, C₁To C₁₀Alkyleneoxy, amine, C₁To C₁₀Alkylamine, F, Cl, Br, I and phenyl;

wherein R is₃To R₁₀Two of which can be fused to form a ring structure;

m is selected from the group consisting of: calcium, strontium, lithium, zinc, magnesium, and monobasic aluminum;

n is 1 or 2;

z is 1 or 2;

the sum of n + z is 3.

Background

Films made from polyethylene are generally known in the art and are particularly useful for packaging applications. Especially in the latter application, good optical, mechanical and barrier properties are required. Furthermore, since packaging applications generally require heat sealing, such films should also have good sealing properties, such as heat stability, etc.

Therefore, a specific performance profile is required in order to meet the above requirements.

Summary of The Invention

The present invention relates to a polymer composition comprising a bimodal or multimodal ethylene polymer (P) and a nucleating agent which is a dicarboxylic acid of a cyclic alkane. Furthermore, the present invention relates to an article comprising said polymer composition and to the use of a nucleating agent, which is a dicarboxylic acid of a cyclic alkane, for reducing the water vapour transmission rate and the oxygen transmission rate of a polyethylene film.

Examples

Preparation of ethylene copolymers

Catalyst preparation

130 g of the metallocene complex bis (1-methyl-3-n-butylcyclopentadienyl) zirconium (IV) dichloride (CAS No. 151840-68-5) and 9.67kg of a 30% solution of commercial Methylaluminoxane (MAO) in toluene were combined and 3.18kg of dry purified toluene were added. The complex solution thus obtained was added by very slow spraying over 2 hours to 17kg of a silica support Sylopol 55SJ (supplied by Grace). The temperature was maintained below 30 ℃. The mixture was allowed to react for 3 hours at 30 ℃ after the addition of the complex.

Polymerisation

Multimodal polymers are produced in a multistage reactor system comprising a loop reactor and a gas phase reactor. The prepolymerization step precedes the actual polymerization step. Using the polymerization catalyst prepared above, at 50dm³The prepolymerization stage was carried out in slurry at about 60 ℃ and a pressure of about 65 bar in a loop reactor. With (220g of C₂) /(1 g/catalyst) ethylene was fed. Propane was used as diluent, with (25g of C)₄) /(1kg of C)₂) 1-butene in an amount to give a prepolymer MFR₂Hydrogen was fed in an amount adjusted to about 6g/10 min.

The slurry obtained was introduced, together with the prepolymerized catalyst, into a 500dm reactor operating at 85 ℃ and 64 bar pressure³In the loop reactor, a continuous feed of propane, ethylene, hydrogen and 1-butene was also introduced so that the ethylene content in the reaction mixture was 4.0 mol%. When the process conditions are adjusted to form the MFR₂6g/10min and a density of about 938kg/m³In the case of the polymer (b), H in the reactor₂/C₂Is 0.15mol/kmol and the molar ratio of 1-butene to ethylene is 110 mol/kmol.

The polymer was withdrawn from the loop reactor and introduced into a flash tank operating at a pressure of 3 bar and a temperature of 60 ℃.

The polymer is introduced from the flash tank into a fluidized bed gas phase reactor, to which further ethylene, 1-hexene comonomer and hydrogen are added, and as inert gasNitrogen to produce the HMW component in the presence of the LMW component such that the ethylene content in the reactor gas is 37 mole%. When the process conditions are adjusted to form the final polymer, the gas phase reactor is operated at a temperature of 75 ℃ and a pressure of 20 bar, and H in the reactor₂/C₂Is 0.4mol/kmol and C₆/C₂After collecting the polymer, it was blended with additives and extruded into pellets in a counter-rotating twin-screw extruder JWCIM 90P to give an MFR₂1.5g/10min and a density of 917kg/m³The polymer of (1). The split ratio between the polymer produced in the loop reactor and the polymer produced in the gas phase reactor was 42/58. The polymer produced in the prepolymerization represents about 1.0 to 1.8% of the total polymer and is calculated as the amount of loop product.

The three multimodal polymers (a), (B) and (C) were produced according to the above procedure using the same polymerization conditions. Average M of these polymers_n23700g/mol, average M_w94000g/mol, average M_z183500g/mol, average molecular weight distribution MWD (M)_w/M_n) It was 4.0. Average C₄Content 0.40 mol% and average C₆Content 2.83 mol%. Average SHI_2.7/210It was 2.87.

The Heterogeneity Factors (HF) determined by cross-fractionation chromatography (CFC) and molecular weights determined by GPC as described above are summarized in tables 1 and 2.

Table 1: CFC results

Table 2: GPC results:

	Mw	Mn	PD	Mz	Mv
						polymer (A)	94900	23800	4.0	185500	82450
Polymer (B)	93500	23900	3.9	181500	81300
						Polymer (C)	93500	23400	4.0	183500	81250
Mean value of	93966	23700	3.9	183500	81666

Inventive example 1(IE1)

The ethylene copolymer (polymers (a), (B) and (C) compounded together) was mixed with HPN-20E (a mixture of 66 wt% of (1R,2S) -calcium cyclohexane dicarboxylate and 34 wt% of zinc stearate (available from Milliken)) to obtain a final amount of HPN-20E of 500ppm based on the resulting composition, and the film was produced on a co-extrusion film blow line (available from dr. The parameters are as follows:

-blow-up ratio (BUR): 3;

-die diameter: 60 mm;

-die gap: 1.2 mm;

-frost line height: 4 times the die diameter;

comparative example 1(CE1)

The procedure of inventive example 2 was repeated except that HPN-20E was not used. Therefore, no corresponding mixing step is performed either.

The optical, mechanical and barrier properties of the compositions according to inventive example IE1 and comparative example CE1 are summarized in table 3.

Table 3: performance of comparative and inventive compositions

	IE1	CE1
			MD tensile modulus (1% secant) (MPa)	212.00	162.00
MD tear Strength (N)	5.37	5.44
			Dart impact Strength (DDI) (g)	1008.10	1218.10
Percent haze (%)	10.60	29.50
			Gloss at 20 °	53.73	6.02
Gloss at 60 °	105.40	47.68
			Gloss at 85 °	99.74	85.72
Yellowness Index (YI)	3.29	3.33
			Oxygen transmission rate (ml/(m)2Day))	3614.00	6382.00
Water vapor transmission rate (g/(m)2Day))	8.06	11.46
			SIT (at 5N) (. degree.C.)	87.59	87.81
Temperature of Hot tack (at 1N) (. degree.C.)	78.46	83.65

The results in the above table show a significant increase in tensile modulus (i.e., stiffness) (30% increase) using 500ppm HPN-20E. Furthermore, the tear strength is not affected. The dart drop impact strength was reduced by 17%, but this was not significant.

In addition, with HPN-20E, the haze was significantly reduced by 64% and the gloss value was significantly increased. The gloss at 60 ° is even improved by 121%.

The use of HPN-20E does not lead to yellowing of the polymer.

In addition, the barrier properties are significantly improved. The Oxygen Transmission Rate (OTR) is reduced by nearly 43% and the water vapor transmission rate (WVR) is reduced by nearly 30%.

The SIT using the HPN-20E film was nearly identical to the SIT of the neat polymer, and the hot tack was improved (by nearly 6.6%).

Thus, the above results show that the inventive compositions provide films with better mechanical strength, optical properties, barrier properties and hot tack without a large negative impact on sealing and toughness properties.

Inventive example 2(IE2)

The ethylene copolymer (polymers (a), (B) and (C) compounded together) was melt blended with HPN-20E (a mixture of 66 wt% of (1R,2S) -calcium cyclohexane dicarboxylate and 34 wt% of zinc stearate (available from Milliken)) to obtain a final amount of HPN-20E of 1500ppm based on the resulting composition and extruded using a ZSK-57 melt extruder, the melt processing conditions summarized in table 4.

Table 4: melt processing conditions

Comparative example 3(CE3)

The procedure of inventive example IE2 was repeated except that no HPN-20E was added, i.e., the pure polymer was subjected to the same compounding process as used in inventive example IE 2.

Comparative example 4(CE4)

An approved 1018HA (a unimodal ethylene-hexene copolymer available from ExxonMobil) was melt blended with HPN-20E in the same manner as inventive example IE2 to obtain a final amount of 1500ppm based on the resulting composition HPN-20E.

Comparative example 5(CE5)

The procedure of comparative example 4 was repeated except that no HPN-20E was added, i.e., the neat polymer was subjected to the same compounding procedure as used in comparative example CE 4.

The Oxygen Induction Times (OITs) of examples IE2, CE3, CE4 and CE5 were measured and compared and the results are as follows.

OIT(IE2)/OIT(CE3)＝96.8％

OIT(CE4)/OIT(CE5)＝31.0％

Since the compositions without HPN-20E and the corresponding compositions with HPN-20E were subjected to the same compounding conditions, the results above show that the OIT of the bimodal polymer remains essentially unchanged after the addition of HPN-20E, whereas in the case of unimodal polyethylene, the OIT decreases significantly.