Polymer composition useful for the manufacture of blown films

Abstract

The present invention relates to a polymer composition comprising at least the following components: A) 70.0 to 95.0 wt.%, based on the total weight of the polymer composition, of a C2C3 random copolymer; wherein the C2C3 random copolymer has a melting point of 110 to 140 °C, determined by differential scanning calorimetry according to ISO 11357-3; an MFR2 (230 °C, 2.16 kg) of 0.5 to 4.0 g / 10 min, determined according to ISO 1133; and a total C2 content of 1 to 10 wt.%, based on the total weight of the C2C3 random copolymer; B) 5.0 to 30.0 wt.%, based on the total weight of the polymer composition, of a LDPE; wherein the LDPE has a density of 915 to 922 kg / m 3 3 according to ISO 1183; and an MFR2 (190 °C, 2.16 kg) of 0.9 to 20.0 g / 10 min, determined according to ISO 1133; with the proviso that the weight proportions of components A) and B) add up to 100 wt.%. Furthermore, the present invention relates to an article, preferably a blown film, made from the polymer composition.

Description

Technical Field

[0001] This invention relates to a polymer composition comprising a specific C2C3 random copolymer as component A) and a specific LDPE as component B). Furthermore, this invention relates to articles comprising the polymer composition, and preferably, the articles are blown films. Background Technology

[0002] Polypropylene has increasingly succeeded in replacing polyethylene in many technological fields because the new generation of polypropylene typically offers enhanced properties compared to traditional polyethylene materials. This is also true for the blown film industry, where polypropylene leverages molecular engineering to overcome the material deficiencies previously used in blown film production.

[0003] The blown film industry is becoming increasingly important in various application areas, such as industrial packaging, consumer product packaging, bags and sacks, laminated films, barrier films, food or medical product packaging, agricultural films, hygiene products, and product packaging.

[0004] There is a need for packaging materials with satisfactory optical properties, such as low haze, while also possessing good mechanical and sealing properties. Typically, an improvement in one desired property comes at the expense of at least one other property. Various attempts have been made to address these issues.

[0005] WO97 / 42258A1 relates to polyolefin compositions for sealing / release films, comprising (by weight percentage): A) 20 to 50% HDPE, LDPE, or EVA with an MFR greater than 0.3 g / 10 min; B) 30-80% random copolymers of propylene and ethylene and / or C4-C8 α-olefins, or polyolefin compositions comprising not less than 20% of said random copolymers of propylene; C) 0 to 20% elastomers or elastomer-thermoplastic olefin polymers. The optical properties of the films are not disclosed, but the compositions suggest poor haze levels.

[0006] EP1813423A1 relates to transparent and rigid co-extruded polypropylene blown films, wherein an ink-printable surface layer is bonded to a base layer or core layer without an intermediate layer, wherein the core layer or base layer comprises at least 50% of at least one of polypropylene homopolymer, polypropylene random copolymer, or multiphase polypropylene copolymer, and the surface layer consists of a mixture of at least 50% low-density polyethylene and at least 10% metallocene linear low-density polyethylene and up to 5% commonly used additives, or a mixture of a polypropylene random copolymer having an MFR of 0.8 to 3.0 g / 10 min (ISO 1133, at 230°C, 2.16 kg) with up to 50% low-density polyethylene, linear low-density polyethylene, or metallocene linear low-density polyethylene having an MFR of 0.5 to 3.5 g / 10 min, and up to 5% commonly used additives. These films can be used for labeling applications and lamination, but due to the high polyethylene content, they have poor thermal stability.

[0007] EP1831016A2 relates to film materials or structures obtained by co-extruding a rubber-impact-modified multiphase copolymer core layer with at least one second polyolefin. The second polyolefin may be Ziegler-Natta catalyzed polyethylene (ZN PE), Ziegler-Natta catalyzed random copolymer of polypropylene (ZN PP RCP), metallocene catalyzed random copolymer of polypropylene (mPPRCP), linear low-density polyethylene (LLDPE), and / or metallocene catalyzed medium-density polyethylene (mMDPE). These sheet or film materials may be co-extruded with other resins or laminated with other materials after extrusion. The multiphase base polymer inevitably results in high haze in the corresponding film. Summary of the Invention

[0008] Therefore, one object of the present invention is to provide a polymer composition capable of producing blown films with superior optical properties, particularly low haze, while also exhibiting good mechanical and sealing properties. Furthermore, one object of the present invention is to provide a polymer composition with good processability, particularly in the process of processing into blown films.

[0009] These objectives have been achieved by the polymer compositions of the present invention, which comprise at least the following components:

[0010] A) 70.0 to 95.0 wt% of a C2C3 random copolymer, based on the total weight of the polymer composition; wherein the C2C3 random copolymer has:

[0011] The melting point of 110 to 140 °C as determined by differential scanning calorimetry according to ISO 11357-3 standard;

[0012] MFR2 (230°C, 2.16 kg), measured according to ISO 1133 standard, is 0.5 to 4.0 g / 10 min.

[0013] Based on the total weight of the C2C3 random copolymer, the total C2 content is 1 to 10 wt.%.

[0014] B) 5.0 to 30.0 wt.% LDPE based on the total weight of the polymer composition; wherein the LDPE has:

[0015] According to ISO 1183 standard, the concentration is between 915 and 922 kg / m³. 3 Density within the range; and

[0016] MFR2 (190°C, 2.16 kg) was measured in the range of 0.9 to 20.0 g / 10 min according to ISO 1133 standard.

[0017] The condition is that the weight ratio of components A) and B) is 100 wt.%.

[0018] The present invention also relates to an article comprising the polymer composition as described herein, wherein the article is defined as a blown film. The present invention further relates to a preferred embodiment of the blown film, and further relates to a flexible packaging system comprising the blown film as described herein.

[0019] definition

[0020] Quantity indication

[0021] The polymer composition of the present invention comprises components A) and B) and optional additives. The requirement applicable herein is that components A) and B), and if present, the sum of the additives, is 100 wt.%. The fixed range indicated for the quantities of individual components A) and B) and optional additives should be understood to mean that, provided the requirement is strictly met—that the sum of all components A) and B) and optional additives reaches 100 wt.—any amount of each individual component can be selected within the specified range.

[0022] When the term "comprising" is used in this specification and claims, it does not exclude other non-specific elements that have important or secondary functions. For the purposes of this invention, the term "consisting of" is considered a preferred embodiment of "comprising...". If, hereinafter, a group is defined as including at least a certain number of embodiments, it can also be understood as disclosing a group that preferably consists only of those embodiments.

[0023] Whenever the terms “include” or “have” are used, they are equivalent to “include” as defined above.

[0024] When a definite or indefinite article is used to refer to a singular noun, such as "a", "an", or "the", the plural form of the noun is also included, unless otherwise specified.

[0025] C2C3 random copolymer (component A)

[0026] The polymer composition of the present invention comprises, as component A), 70.0 to 95.0 wt% of a C2C3 random copolymer based on the total weight of the polymer composition, wherein the C2C3 random copolymer has a melting point of 110 to 140°C as determined by differential scanning calorimetry according to ISO 11357-3; an MFR2 (230°C, 2.16 kg) of 0.5 to 4.0 g / 10 min as determined according to ISO 1133; and a total C2 content of 1 to 10 wt.% based on the total weight of the C2C3 random copolymer.

[0027] The preferred implementation scheme of component A will be discussed below.

[0028] In a preferred embodiment of the present invention, component A) comprises a1) 50.0 to 85.0 wt% of a polymer portion having i) a C2 content in the range of 2.0 to less than 5.5 wt%, preferably 2.0 to 5.49 wt%; and ii) a melt flow rate MFR2 (230°C / 2.16 kg) of 0.5 to 5.0 g / 10 min as determined according to ISO 1133; and a2) 15.0 to 50.0 wt% of a polymer portion having i) a C2 content of 5.5 to 10.0 wt%; and ii) a melt flow rate MFR2 (230°C / 2.16 kg) of 0.1 to 3.0 g / 10 min as determined according to ISO 1133; wherein the melt flow rate MFR2 (230°C / 2.16 kg) of the polymer portion a2) is lower than the MFR2 (230°C / 2.16 kg) of the polymer portion a1).

[0029] In another preferred embodiment, the melting point of component A) is determined by differential scanning calorimetry according to ISO 11357-3, in the range of 115 to 138°C, preferably in the range of 120 to 136°C, and more preferably in the range of 128 to 135°C.

[0030] In another preferred embodiment of this application, based on the total weight of component A), the total C2 content in component A) is in the range of 1.5 to 8.0 wt.%, preferably in the range of 2.0 to 7.0 wt.%, and more preferably in the range of 2.5 to 5.5 wt.%.

[0031] In another preferred embodiment, according to ISO 1133, the melt flow rate MFR2 (230°C / 2.16kg) of component A is measured to be 0.7 to 3.5 g / 10min, preferably in the range of 0.8 to 2.5 g / 10min, more preferably in the range of 1.0 to 2.0 g / 10min, and even more preferably in the range of 1.0 to 1.5 g / 10min.

[0032] In another preferred embodiment of the present invention, based on the total weight of component A), the xylene soluble content (XCS) in component A) is determined according to ISO 16152 standard, 1ed, 25°C, to be 0.5 to 15.0 wt.%, preferably in the range of 1.0 to 10.0 wt.%, and more preferably in the range of 2.5 to 4.5 wt.%.

[0033] In another preferred embodiment of the invention, based on the total weight of component A), the content of unit components derived from comonomers other than ethylene and propylene in component A) is less than 7 wt.%, preferably in the range of 0 to 3 wt.%, more preferably in the range of 0.1 to 3 wt.%, and even more preferably component A) is composed of units derived from ethylene and propylene.

[0034] In another preferred embodiment of the present invention, the glass transition temperature of component A) is determined by differential scanning calorimetry according to ISO 11357-2, and preferably in the range of -20 to 0°C, preferably in the range of -10 to -1°C.

[0035] In another preferred embodiment of the invention, the content of component A) in the polymer composition is 75 to 94 wt.%, preferably in the range of 85 to 93 wt.%, and more preferably in the range of 88 to 92 wt.%, based on the total mass of the polymer composition.

[0036] In another preferred embodiment of the invention, component A) is available, preferably in the presence of a metallocene catalyst.

[0037] Preferred metallocene catalysts include,

[0038] i) Complex of formula (Ⅰ):

[0039]

[0040] Where M is zirconium or hafnium;

[0041] Each X is a sigma ligand;

[0042] L is a divalent bridge selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, and -R'2Ge-, where each R' is independently a hydrogen atom, C1-C2, C2-C2- ... 20 Hydrocarbon group, tri(C1-C) 20 Alkyl)silyl, C6-C 20 Aryl, C7-C 20 Aryl or C7-C 20 Alkyl aryl;

[0043] R 2 and R 2 'Each is independently C1-C 20 A hydrocarbon group, which optionally contains one or more heteroatoms from groups 14 to 16;

[0044] R 5 'For C 1-20 A hydrocarbon group containing one or more heteroatoms of group 14 to 16, which are optionally substituted with one or more halogen atoms;

[0045] R 6 and R 6 Each is independently a hydrogen atom or a carbon atom. 1-20 Hydrocarbon group, the C 1-20 The hydrocarbon group optionally contains one or more heteroatoms from groups 14-16; wherein R 6 'Preferably tertiary alkyl;'

[0046] R 7 It is a hydrogen atom or a carbon atom. 1-20 Hydrocarbon group, the C 1-20 The hydrocarbon group optionally contains one or more heteroatoms from groups 14-16, and R 7 It is a hydrogen atom;

[0047] Ar and Ar' are each independently an aryl or heteroaryl group having a maximum of 20 carbon atoms, which is optionally surrounded by one or more R atoms. 1 Group substitution;

[0048] Each R 1 It is C 1-20 Two Rs on a hydrocarbon group or adjacent carbon atom 1 The groups together can form a 5- or 6-membered nonaromatic ring fused with an Ar or Ar' group, wherein the nonaromatic ring itself is optionally surrounded by one or more R groups. 4 Group substitution; each R 4 It is C 1-20 hydrocarbon groups; and

[0049] (ii) A co-catalyst comprising at least one or two compounds having a Group 13 metal, preferably an Al and / or boron compound.

[0050] The conditions for preparing component A are described in a European patent application (application number: 19177302.7, filed on 29 May 2019) filed by the same applicant as this application, but not published at the time of filing.

[0051] Component A) is preferably prepared by polymerizing propylene and ethylene by a sequential polymerization method comprising at least two reactors connected in series in the presence of a metallocene catalyst.

[0052] Preferably, component A) is prepared in a sequential polymerization method comprising at least two polymerization reactors (R1) and (R2), wherein a first polymer fraction a1) is generated in the first polymerization reactor (R1) and subsequently transferred to the second polymerization reactor (R2). In the second polymerization reactor (R2), a second polymer fraction a2) is generated in the presence of the first polymer fraction a1).

[0053] Polymerization methods suitable for producing component A) typically involve at least two polymerization stages, and each stage can be carried out in solution, slurry, fluidized bed, solid phase, or gas phase.

[0054] The preferred multi-stage process for manufacturing component B) is the "loop-gas phase" process, described in patent documents developed by Borealis (known as the BORSTAR® technology), such as EP0887379A1, WO92 / 12182A1, WO2004 / 000899A1, WO2004 / 111095A1, WO99 / 24478A1, WO99 / 24479A1, or WO00 / 68315A1. Another suitable slurry-gas phase process is the Basell Spheripol® process.

[0055] The preferred cocatalyst system for manufacturing component A) comprises a boron-containing cocatalyst, such as a borate cocatalyst and an aluminoxane cocatalyst. More preferably, the catalyst is supported on a silica support.

[0056] Typically, the catalyst system used in this invention can be prepared as described in WO2018 / 122134A1. The catalyst can be used in supported or unsupported form, preferably in supported form.

[0057] Component B)

[0058] The polymer composition of the present invention comprises, as component B), 5.0 to 30.0 wt.% of LDPE based on the total weight of the polymer composition; wherein the LDPE has a strength of 915 to 922 kg / m³ as determined according to ISO 1183. 3The density; and the MFR2 (190°C, 2.16 kg) measured according to ISO 1133 standard from 0.9 to 20.0 g / 10 min.

[0059] The preferred implementation scheme of component B will be discussed below.

[0060] In a preferred embodiment of the present invention, the MFR2 (190°C, 2.16 kg) of component B) is measured according to ISO 1133 standard in the range of 2.0 to 15.0 g / 10 min, preferably in the range of 4.0 to 12.0 g / 10 min, more preferably in the range of 6.5 to 10.0 g / 10 min, and even more preferably in the range of 6.5 to 8.0 g / 10 min.

[0061] In another preferred embodiment of the invention, component B) has a concentration of 916 to 922 kg / m³ as determined according to ISO 1183 standard. 3 The density is preferably in the range of 917 to 921 kg / m³. 3 Within the range, and more preferably 920 kg / m 3 kg / m 3 .

[0062] In another preferred embodiment of the invention, the hexane-soluble content of component B) is determined on a 100 μm thick cast film according to FDA 177.1520 based on the total weight of component B) and is in the range of 0 to 10.0 wt.%, preferably in the range of 0 to 5.0 wt.%, more preferably in the range of 0 to 1.0 wt.%.

[0063] In another preferred embodiment of the invention, component B) has a melting point of 90 to 120°C, preferably in the range of 95 to 115°C, more preferably in the range of 100 to 115°C, and even more preferably in the range of 107 to 110°C, as determined by differential scanning calorimetry according to ISO 11357-3 standard.

[0064] In another preferred embodiment of the invention, the content of component B in the polymer composition is in the range of 6 to 25 wt.%, preferably in the range of 7 to 15 wt.%, and more preferably in the range of 8 to 12 wt.%, based on the total weight of the polymer composition.

[0065] Preferred materials for component B are available from Borealis AG (Austria) under the trade names CA8200 and CA9150.

[0066] additive

[0067] The polymer compositions of the present invention may also contain additives.

[0068] According to a preferred embodiment of the invention, the polymer composition comprises at least one additive, which is preferably selected from slip agents, acid scavengers, UV stabilizers, pigments, antioxidants, additive carriers, nucleating agents and mixtures thereof, wherein these additives preferably account for 0.1 to 5.0 wt.% of the total weight of the polymer composition, more preferably 0.1 to 4.0 wt.%.

[0069] Examples of antioxidants that can be used are sterically hindered phenols (e.g., CAS No. 6683-19-8, also produced by BASF as Irganox 1010 FF). TM (For sale), phosphorus-based antioxidants (e.g., CAS No. 31570-04-4, also available from Clariant as Hostanox PAR 24 (FF)™ or BASF as Irgafos 168 (FF)). TM (For sale), sulfur-based antioxidants (such as CAS No. 693-36-7, sold by BASF as Irganox PS-802 FL™), nitrogen-based antioxidants (such as 4,4'-bis(1,1'-dimethylbenzyl)diphenylamine), or mixtures of antioxidants.

[0070] The UV stabilizers that can be used in the polymer compositions of the present invention may be, for example, bis-(2,2,6,6-tetramethyl-4-piperidinyl)-sebate (CAS-No. 52829-07-9, Tinuvin 770); 2-hydroxy-4-n-°Ctoxy-benzophenone (CAS-No. 1843-05-6, Chimassorb 81).

[0071] The nucleating agent that can be used in the polymer composition of the present invention may be, for example, sodium benzoate (CAS No. 532-32-1) or 1,3:2,4-bis(3,4-dimethylbenzyl)sorbitol (CAS 135861-56-2, Millad 3988).

[0072] polymer composition

[0073] Preferred embodiments of the polymer compositions of the present invention will now be discussed.

[0074] In another preferred embodiment of the present invention, the content of component A) in the polymer composition is in the range of 75 to 94 wt.%, preferably in the range of 85 to 93 wt.%, more preferably in the range of 88 to 92 wt.%, based on the total weight of the polymer composition, and / or the content of component B) in the polymer composition is in the range of 6 to 25 wt.%, preferably in the range of 7 to 15 wt.%, and even more preferably in the range of 8 to 12 wt.%, based on the total weight of the polymer composition.

[0075] The preferred polymer composition of the present invention comprises, and preferably consists of, the following components:

[0076] A) 65.0 to 94.9 wt.%, preferably 84.0 to 92.75 wt.%, of the total weight of the polymer composition; wherein the C2C3 random copolymer has:

[0077] According to ISO 11357-3 standard, the melting point, determined by differential scanning calorimetry, is in the range of 110 to 140°C, preferably in the range of 128 to 135°C.

[0078] MFR2 (230°C, 2.16 kg), measured according to ISO 1133 standard, is within the range of 0.5 to 4.0 g / 10 min, preferably within the range of 1.0 to 2.0 g / 10 min; and

[0079] Based on the total weight of the C2C3 random copolymer, the total C2 content is in the range of 1 to 10 wt.%, preferably in the range of 2.5 to 5.5 wt.%.

[0080] B) Based on the total weight of the polymer composition, 5.0 to 30.0 wt.%, preferably 7 to 15 wt.%, of LDPE; wherein the LDPE has:

[0081] According to ISO 1183 standard, the concentration is between 915 and 922 kg / m³. 3 Within the range, preferably 917 to 921 kg / m³ 3 Density within the range; and

[0082] MFR2 (190°C, 2.16 kg) was measured according to ISO 1133 standard in the range of 0.9 to 20.0 g / 10 min, preferably in the range of 6.5 to 10.0 g / 10 min.

[0083] C) Based on the total weight of the polymer composition, 0.1 to 5.0 wt.%, preferably 0.25 to 1.0 wt.%, of additives, preferably selected from one or more of slip agents, acid scavengers, UV stabilizers, pigments, antioxidants, additive carriers, nucleating agents, and mixtures thereof;

[0084] The condition is that the sum of the weight ratios of components A), B), and C) is 100 wt.%.

[0085] blown film

[0086] The present invention also relates to blown films comprising or composed of the polymer compositions of the present invention.

[0087] Preferred embodiments of the blown film of the present invention will now be discussed.

[0088] According to a preferred embodiment of the present invention, on a blown film with a thickness of 50 μm, the sealing initiation temperature of the blown film is determined to be in the range of 80°C to below 120°C, preferably in the range of 90°C to 110°C, and more preferably in the range of 98°C to 105°C.

[0089] In another preferred embodiment, the crystallization temperature (Tc) measured by differential scanning calorimetry on a blown film with a thickness of 50 μm, according to ISO 11357-3, is 80 to 95°C, preferably 85 to 90°C.

[0090] In another preferred embodiment of the invention, the blown film has two melting points, wherein the first melting point, determined by differential scanning calorimetry according to ISO 11357-3, is in the range of 110 to 130°C, preferably in the range of 115 to 125°C, more preferably in the range of 119 to 121°C, and the second melting point, determined by differential scanning calorimetry according to ISO 11357-3, is in the range of 100 to 115°C, preferably in the range of 103 to 112°C, more preferably in the range of 106 to 108°C.

[0091] According to another preferred embodiment of the invention, the blown film with a thickness of 50 μm, measured at 23°C according to ISO 527-3, has a tensile modulus in the machine direction and transverse direction in the range of 200 to 1000 MPa, preferably in the range of 300 to 700 MPa, and more preferably in the range of 500 to 600 MPa.

[0092] In another preferred embodiment of the invention, the blown film with a thickness of 50 μm is measured according to ASTM D1709 Method A, and the blown film has a dart impact strength in the range of 20 to 2000 g, preferably in the range of 40 to 1000 g, more preferably in the range of 45 to 500 g, even more preferably in the range of 50 to 300 g, and even more preferably in the range of 55 to 80 g.

[0093] In another preferred embodiment of the invention, the blown film has an Elmendorf tear strength, measured in the machine direction according to ISO 6383 / 2, ranging from 1.0 N / mm to 50.0 N / mm, preferably in the range of 4.0 to 20.0 N / mm, and more preferably in the range of 6.0 to 10.0 N / mm.

[0094] According to another preferred embodiment of the invention, the blown film has an Elmendorf tear strength in the transverse (TD) direction ranging from 5.0 N / mm to 100.0 N / mm, preferably in the range of 10.0 to 40.0 N / mm, and more preferably in the range of 15.0 to 25.0 N / mm, as measured according to ISO 6383 / 2 standard.

[0095] In another preferred embodiment of the invention, the blown film has a haze of less than 4.2% as measured according to ASTM D1003-00 for a blown film with a thickness of 50 μm, preferably in the range of 0.1 to 4.0%, more preferably in the range of 0.5 to 3.3%.

[0096] To manufacture blown films, the melt of the polymer composition of the present invention is extruded through an annular die and blown into a tubular film by forming bubbles, which collapse between rolls after solidification. The blow extrusion can preferably be carried out in a temperature range of 160 to 240°C for 25 seconds, and cooled by water or preferably by blowing air (usually air) at a temperature of 10 to 50°C to provide a frosting height of 0.5 to 8 times the die diameter. The expansion ratio should generally be in the range of 1.5 to 4, for example 2 to 4, preferably 2.5 to 3.5.

[0097] Flexible Packaging System

[0098] The present invention also relates to flexible packaging systems selected from bags or pouches for food and pharmaceutical packaging that include the blown film of the present invention.

[0099] The invention will now be described with reference to the following non-limiting embodiments. Detailed Implementation

[0100] Experimental Section

[0101] A. Measurement Method

[0102] Unless otherwise defined, the following definitions of terms and measurement methods apply to the above general description of the invention and the following embodiments.

[0103] melt flow rate

[0104] Melt flow rate (MFR) is measured according to ISO 1133 - Determination of melt mass flow rate (MFR) and melt volumetric flow rate (MVR) of thermoplastics - Part 1: Standard methods, expressed in g / 10 min. MFR is an indicator of polymer flowability and processability. A higher melt flow rate generally indicates a lower polymer viscosity. The MFR² for polyethylene was measured at 190°C and a load of 2.16 kg. The MFR² for polypropylene was measured at 230°C and a load of 2.16 kg.

[0105] The C2- and C3- contents of component A were determined by NMR.

[0106] Quantitative nuclear magnetic resonance (NMR) spectroscopy was further used to quantify the comonomer content and comonomer sequence distribution of the polymer. Measurements were performed using a Bruker Advance III 400 NMR spectrometer at 400.15 and 100.62 MHz, respectively. 1 H and 13 C, Record quantitative values ​​in solution. 13 C{ 1 ¹H NMR spectra. Recording used 13A C-optimized 10mm extended temperature probe was used for all spectra of all pneumatic devices using nitrogen at 125°C. Approximately 200 mg of material was dissolved in 3 mL of 1,2-tetrachloroethane-d2 (TCE-d2) with chromium-(III)-acetylacetonate (Cr(acac)3) to obtain a 65 mM relaxant solution (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure homogeneity of the solution, the NMR tubes were further heated in a rotary oven for at least 1 hour after initial sample preparation in a heating block. After inserting the magnet, the tubes were rotated at a frequency of 10 Hz. This setup was chosen primarily for the need for high resolution and accurate quantification of ethylene content. Standard single-pulse excitation was used without NOE, employing an optimized tip angle, a 1-second cyclic delay, and a dual-layer WALTZ16 decoupling scheme (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6k) transients were obtained for each spectrum. Quantitative analysis was performed. 13 C{ 1 The ¹H NMR spectra were processed, integrated, and the relevant quantitative characteristics were determined from the integration using a proprietary computer program. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at a chemical shift of 30.00 ppm using solvent. This method allows for comparison even in the absence of this structural unit. Characteristic signals corresponding to ethylene incorporation were observed (Cheng, HN, Macromolecules 17 (1984), 1950).

[0107] With the observation of characteristic signals corresponding to erythro regio defects (2,1 red region defects) (as described in L. Resconi, L. Cavallo, A. Fait, F. Piemontesi, Chem. Rev. 2000, 100 (4), 1253, in Cheng, HN, Macromolecules 1984, 17, 1950, and WJ. Wang and S. Zhu, Macromolecules 2000, 33 1157), it is necessary to correct for the influence of regional defects on the determination of properties. No characteristic signals corresponding to other types of regional defects were observed.

[0108] The comonomer moiety was quantified using the method of Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157). 13 C{ 1 Multiple signals across the entire spectral region of the H spectrum are integrated. This method was chosen for its robustness and ability to account for regional defects when necessary. Slight adjustments were made to the integration region to increase applicability across the entire range of comonomer contents encountered.

[0109] For systems where only ethylene separation is observed in the PPEPP sequence, Wang et al.'s method has been modified to reduce the influence of non-zero integrals from sites that are known to be absent. This method reduces the overestimation of ethylene content in such systems and achieves this by reducing the number of sites used to determine the absolute ethylene content:

[0110] E=0.5(S + S + S + 0.5(S + S ))

[0111] By using this set of sites, the corresponding integral equation becomes:

[0112] E = 0.5(I H +I G + 0.5(I C + I D ))

[0113] The same notation used in the article by Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157) is used. The equation for absolute propylene content is not modified.

[0114] Calculate the molar percentage of comonomer incorporated from the molar fraction:

[0115] E [mol-%]=100 fE

[0116] Calculate the weight percentage of comonomer incorporated from the mole fraction:

[0117] E [wt.-%]=100 (fE 28.06) / ((fE 28.06) + ((1-fE) 42.08))

[0118] The distribution of comonomer sequences at the ternary level was determined using the analytical method of Kakugo et al. (Kakugo, M., Naito, Y., Mizunuma, K., Miyatake, T. Macromolecules 15 (1982) 1150). This method was chosen because of its robustness and slightly adjusted integration region to increase applicability to a wider range of comonomer contents.

[0119] Xylene cold-soluble compound (XCS)

[0120] The xylene-soluble fraction (XS) defined and described in this invention was determined according to ISO 16152: 2.0 g of polymer was dissolved in 250 mL of p-xylene with stirring at 135 °C. After 30 minutes, the solution was cooled at ambient temperature for 15 minutes, and then allowed to stand at 25 ± 0.5 °C for 30 minutes. The solution was filtered through filter paper into two 100 mL flasks. The solution from the first 100 mL flask was evaporated in a nitrogen stream, and the residue was dried under vacuum at 90 °C until constant weight was achieved. The xylene-soluble fraction (percentage) could then be determined as follows:

[0121] XS%= (100 m V0) / (m0 v); m0 = initial polymer mass (g); m = residue mass (g); V0 = initial volume (mL); v = analytical sample volume (mL).

[0122] Melting temperature T m Crystallization temperature T c and enthalpy of melting H m

[0123] The melting temperature of 5 to 7 mg samples was determined using a TA Instrument Q2000 differential scanning calorimeter (DSC). DSC measurements were performed according to ISO 11357 / Part 3 / Method C2, in a heating / cooling / heating cycle at a scan rate of 10 °C / min, over a temperature range of -30 to +225 °C. Crystallization temperature (T...) c The melting temperature (T) is determined by the cooling step, while the melting temperature (T) is determined by the cooling step. m ) and enthalpy of fusion (H m The value is determined by the second heating step. 50°C is used as the lower limit of integration for calculating the enthalpy of fusion. The melting and crystallization temperatures are taken as the peak values ​​for endothermic and exothermic reactions, respectively.

[0124] Glass transition temperature T g

[0125] Glass transition temperature T g Measured by DSC according to ISO 11357 / Part 2.

[0126] density

[0127] The density of the material was measured according to ISO 1183-1.

[0128] All film properties (except for hexane solubles) were measured on 50 μm thick single-layer blown films produced on the Collin blown film production line. This line had a screw diameter of 30 mm, an L / D ratio of 30, a die diameter of 60 mm, a die clearance of 1.5 mm, and a double-lip cooling ring. Film samples were produced at 210°C with an average thickness of 50 μm, a blow-up ratio of 2.5, and an output rate of approximately 8 kg / h.

[0129] Content of hexane-soluble matter in component A

[0130] 1 g of a 100 μm thick polymer cast film (cooling roller temperature during film formation = 40 °C) was added to 400 mL of hexane at 50 °C, while stirring with a reflux condenser for 2 hours. After 2 hours, the mixture was immediately filtered through N41 filter paper. The precipitate was collected in an aluminum container, and the residual hexane was evaporated in a vapor bath under N2 flow. The amount of hexane-soluble matter was determined by the formula:

[0131] ((Sample weight + Crucible weight) - (Crucible weight)) / (Sample weight) 100.

[0132] Sealing start temperature (SIT); (Sealing end temperature (SET), sealing range)

[0133] The sealing temperature range is the temperature range within which the film can be sealed under the conditions given below. The lower limit (heat seal initiation temperature (SIT)) is the sealing temperature at which a seal strength of >5N is achieved. The upper limit (sealing temperature (SET)) is reached when the film adheres to the sealing device.

[0134] The sealing range was measured on a J&B General Seal Machine 3000 with a film thickness of 50 μm. The parameters are as follows:

[0135] Sample width: 25.4 mm

[0136] Sealing pressure: 0.1 N / mm 2

[0137] Sealing time: 0.1s

[0138] Cooldown time: 99s

[0139] Peeling speed: 10mm / s

[0140] Starting temperature: 80°C

[0141] Finishing temperature: 150°C

[0142] Increment: 10°C

[0143] The sample was sealed from the inside out at each sealing strip temperature, and the sealing strength (force) at each step was measured to determine the temperature at which the sealing strength reached 5N.

[0144] Tensile modulus

[0145] A 50μm thick blown film was produced on a single-layer cast film production line with a melt temperature of 220℃ and a cold rolling roll temperature of 20℃. The longitudinal and transverse tensile moduli were measured at 23℃ according to ISO 527-3 standard. The production thickness of 50μm is shown below. The test was conducted at a crosshead speed of 1mm / min.

[0146] Dart Impact Intensity (DDI)

[0147] DDI was measured from the film samples using ASTM D1709 Method A (optional test technique). A dart with a hemispherical head and a diameter of 38 mm was dropped from a height of 0.66 m onto the film clamped in a hole. Twenty samples were tested consecutively. One weight was used for each group, and the weight was increased (or decreased) in uniform increments for each group. The weight that caused 50% of the samples to fail was calculated and reported.

[0148] Tear strength

[0149] Tear strength (measured as Elmendorf tear (N)): Applicable to both longitudinal (MD) and transverse (TD) measurements. Tear strength is measured using the ISO 6383 / 2 method. A pendulum apparatus is used to measure the force required to propagate a tear across the film sample. The pendulum, under the influence of gravity, swings in an arc, tearing the sample from a pre-cut slit. One side of the film sample is secured by the pendulum, and the other side by a clamp. Tear resistance is the force required to tear the specimen. Relative tear resistance (N / mm) is then calculated by dividing the tear resistance by the film thickness.

[0150] Haze

[0151] Haze was measured according to ASTM D1003-00 on a 50 μm thick film blown as described below.

[0152] B. Materials used

[0153] C2C3 random copolymer (component A)

[0154] In the working embodiment IE1 and comparative examples CE1 and CE2 of the present invention, a C2C3 random copolymer A manufactured as follows was used.

[0155] The catalyst used in the polymerization of C2C3 random copolymer A) is prepared as follows:

[0156] Metallocene (MC1) (racemic-trans-dimethylsilanediyl(2-methyl-4-phenyl-5-methoxy-6-tert-butyl-indenyl)(2-methyl-4-(4-tert-butylphenyl)indenyl)zirconium dichloride)

[0157]

[0158] It has been synthesized according to the steps described in WO 2013 / 007650 A1, E2.

[0159] Preparation of MAO-silica carrier

[0160] The steel reactor, equipped with a mechanical stirrer and filter, was flushed with nitrogen, and the reactor temperature was set to 20°C. DM-L-303 silica grade from AGC Si-Tech Co, pre-calcined at 600°C (7.4 kg), was then added from the feed tank, and the pressure was carefully increased and decreased with nitrogen using a manual valve. Toluene (32 kg) was then added, and the mixture was stirred for 15 minutes. A toluene solution (17.5 kg) of 30 wt.% MAO from Lanxess was then added through the feed line at the top of the reactor over 70 minutes. The reaction mixture was then heated to 90°C and stirred for another two hours at 90°C to allow the slurry to settle, and the mother liquor was filtered off. The MAO-treated carrier was washed twice with toluene (32 kg) at 90°C, followed by precipitation and filtration. The reactor was cooled to 60°C, and the solids were washed with heptane (32.2 kg). Finally, the MAO-treated silica was dried at 60°C for 2 hours under a nitrogen atmosphere, and then dried under vacuum (-0.5 barg) with stirring for 5 hours. The free-flowing white powdery MAO-treated support was collected and found to contain 12.6 wt% Al.

[0161] Preparation of catalyst system

[0162] A 30 wt.% MAO toluene solution (2.2 kg) was added to a steel nitrogen-sealed reactor via a burette at 20 °C. Toluene (7 kg) was then added with stirring. Metallocene MC1 (286 g) was added from a metal cylinder and then washed with 1 kg of toluene. The mixture was stirred at 20 °C for 60 min. Triphenyl methyl tetratetra(pentafluorophenyl)borate (336 g) was then added from a metal cylinder and washed with 1 kg of toluene. The mixture was stirred at room temperature for 1 h. The resulting solution was added to a MAO-silica support stirred cake prepared as described above over 1 h. The filter cake was left to stand for 12 h, then dried under a flow of N2 at 60 °C for 2 h, and further dried under vacuum (-0.5 barg) with stirring for an additional 5 h. Samples were taken from the dried catalyst in the form of a pink free-flowing powder containing 13.9 wt.% Al and 0.26 wt.% Zr.

[0163] The polymerization reaction for preparing the C2C3 random copolymer (A) was carried out in the Borstar pilot plant, which has two reactor configurations (loop-gas phase reactor (GPR1)). The polymerization conditions for the C2C3 random copolymer (A) are given in Table 1.

[0164] Table 1a: Preparation of C2C3 random copolymer (A)

[0165]

[0166] Table 1b: Preparation of C2C3 random copolymer (A)

[0167]

[0168] The polymer powder was compounded with 0.1 wt.% of an antioxidant (Irgafos168FF, CAS No. 6683-19-4), 0.1 wt.% of a sterically hindered phenol (Irganox 1010FF, CAS No. 6683-19-8), and 0.05 wt.% of calcium stearate (wt.% refers to the total weight of the polymer powder) in a Coperion ZSK57 twin-screw extruder at 220°C.

[0169] Table 2: Properties of C2C3 random copolymer (A)

[0170]

[0171] Component B)

[0172] CA8200: CA8200 is a low-density polyethylene (LDPE) produced in an autoclave process. Its melt flow rate (190°C / 2.16 kg) is 7.5 g / 10 min, its melting temperature (measured by DSC according to ISO 11357 / 03) is 108°C, and its density is 920 kg / m³. 3 (As determined according to ISO 1183), it is available from Borealis AG in Austria.

[0173] Other components

[0174] FT5230: FT5320 is a low-density polyethylene available from Borealis AG in Austria. Its density is 923 kg / m³. 3 (Measured according to ISO 1183), the melt flow rate (190°C / 2.16 kg) is 0.75 g / 10 min, and the melting temperature (measured by DSC according to ISO 11357 / 03) is 112°C.

[0175] C. Manufacturing of blown film

[0176] The components were mixed in a Collin 30 laboratory-scale blown film machine, and 50 μm single-layer blown films (BUR=1:2.5) were produced using the same production line. The components were premixed in a dense mixer prior to mixing. Table 3 shows the composition and film parameters of the polymer compositions according to comparative examples CE1 and CE2 and example IE1 of the present invention.

[0177] Table 3: Composition and Properties of Blown Films

[0178]

[0179] D. Results and Discussion

[0180] As can be seen from Table 3, the addition of the specific LDPE of the present invention (component (B)) to component (A) can improve the optical properties of the blown film, particularly haze (see comparison of CE1 and IE1), without reducing the mechanical properties of the blown film. CE2 shows that the addition of LDPE (FT5230) outside the scope of the present invention results in poor optical properties of the film, particularly a significant increase in haze.

Claims

1. A polymer composition comprising at least the following components: A) 70.0 to 95.0 wt% of a C2C3 random copolymer based on the total weight of the polymer composition; wherein the C2C3 random copolymer has: Melting point in the range of 110 to 140 °C as determined by differential scanning calorimetry according to ISO 11357-3; According to ISO 1133, the MFR2 was determined at 230°C and 2.16 kg, within the range of 0.5 to 4.0 g / 10 min. Based on the total weight of the C2C3 random copolymer, the total C2 content ranges from 1 to 10 wt.%; and, The xylene soluble content, determined according to ISO 16152, 1ed, at 25°C, is in the range of 1.0 to 4.5 wt.% based on the total weight of component A); in, Component A) consists of the following: a1) 50.0 to 85.0 wt% of the polymer portion has: i) C2 content in the range of 2.0 to 5.49 wt%; ii) The melt flow rate MFR2, measured at 230°C and 2.16 kg according to ISO 1133, in the range of 0.5 to 5.0 g / 10 min; and, a2) 15.0 to 50.0 wt% of the polymer portion has: i) C2 content in the range of 5.5 to 10.0 wt%; ii) Melt flow rate MFR2, measured at 230°C / 2.16 kg according to ISO 1133, in the range of 0.1 to 3.0 g / 10 min; Among them, the melt flow rate (MFR2) of polymer part a2) is lower than that of polymer part a1); B) 5.0 to 30.0 wt.% of LDPE based on the total weight of the polymer composition; wherein the LDPE has: According to ISO 1183, the concentration is between 915 and 922 kg / m³. 3 Density within the range; and, MFR2 was determined according to ISO 1133 at 190°C and 2.16 kg in the range of 0.9 to 20.0 g / 10 min. C) Optionally, at least one additive; The condition is that the weight ratio of components A), B) and optionally C) is 100 wt.%.

2. The polymer composition according to claim 1, characterized in that, Component A) has: Melting point in the range of 128 to 135 °C, determined by differential scanning calorimetry according to ISO 11357-3; and / or, Based on the total weight of component A), the total C2 content in the range of 2.5 to 5.5 wt.%; and / or, The melt flow rate MFR2, measured at 230°C / 2.16 kg according to ISO 1133, in the range of 1.0 to 2.0 g / 10 min.

3. The polymer composition according to claim 1, characterized in that, Component A) has: The xylene-soluble content, determined according to ISO 16152, 1ed, 25°C, in the range of 2.5 to 4.5 wt.% based on the total weight of component A; and / or, Based on the total weight of component A), the content of unit components derived from comonomers different from ethylene and propylene in component A is in the range of 0 to 3 wt.%; and / or, The glass transition temperature in the range of -10 to -1 °C is determined by differential scanning calorimetry according to ISO 11357-2.

4. The polymer composition according to claim 1, characterized in that, Component A) is obtained in the presence of a metallocene catalyst; wherein the metallocene catalyst comprises: i) Complex of formula (Ⅰ): ， Where M is zirconium or hafnium; Each X is a sigma ligand; L is a divalent bridge selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, and -R'2Ge-, where each R' is independently a hydrogen atom, C1-C2, C2-C2- ... 20 Hydrocarbon group, tri(C1-C) 20 Alkyl)silyl, C6-C 20 Aryl, C7-C 20 Aryl or C7-C 20 Alkyl aryl; R 2 and R 2 'Each is independently C1-C 20 Hydrocarbon group or C1-C containing one or more heteroatoms from groups 14 to 16 20 hydrocarbon group; R 5 'A C-type carbon atom containing one or more unsubstituted or substituted halogen atoms from groups 14 to 16'. 1-20 hydrocarbon group; R 6 and R 6 Each is independently a hydrogen atom or a carbon atom. 1-20 Hydrocarbon group or C containing one or more heteroatoms from groups 14-16 1-20 hydrocarbon group; R 7 It is a hydrogen atom or a carbon atom. 1-20 Hydrocarbon group or C containing one or more heteroatoms from groups 14-16 1-20 hydrocarbon group, and R 7 It is a hydrogen atom; Ar and Ar' are each independently an aryl or heteroaryl group having a maximum of 20 carbon atoms, which is unsubstituted or converted by one or more R atoms. 1 Group substitution; Each R 1 It is C 1-20 Two Rs on a hydrocarbon group or adjacent carbon atom 1 The groups together form a 5 or 6-membered nonaromatic ring fused to an Ar or Ar' group, wherein the nonaromatic ring itself is not substituted or is fused to one or more R groups. 4 Group substitution; each R 4 It is C 1-20 hydrocarbon group; and, (ii) Contains at least one or two cocatalysts having a Group 13 metal compound.

5. The polymer composition according to any one of the preceding claims, characterized in that, Component B) has: MFR2 in the range of 6.5 to 10.0 g / 10 min, determined according to ISO 1133 at 190 °C and 2.16 kg; and / or, According to ISO 1183, the concentration is between 917 and 921 kg / m³. 3 Density within the range; and / or, Based on the total weight of component B), the hexane-soluble content in the range of 0 to 5.0 wt.% as determined on a 100 μm thick cast film according to FDA 177.1520; and / or, According to ISO 11357-3, the melting point in the range of 90 to 120 °C is determined by differential scanning calorimetry.

6. The polymer composition according to claim 1, characterized in that, The polymer composition comprises at least one additive (C), which is selected from one or more of slip agents, acid scavengers, UV stabilizers, pigments, antioxidants, additive carriers, nucleating agents, and mixtures thereof, wherein the additives account for 0.1 to 5.0 wt.% of the total weight of the polymer composition.

7. The polymer composition according to claim 1, characterized in that, Based on the total weight of the polymer composition, the content of component A) in the polymer composition is 75 to 94 wt.%; and / or, Based on the total weight of the polymer composition, the content of component B in the polymer composition is in the range of 6 to 25 wt.%.

8. The polymer composition according to claim 1, characterized in that, The polymer composition consists of the following components: A) 70.0 to 94.9 wt.% of a C2C3 random copolymer based on the total weight of the polymer composition; wherein the C2C3 random copolymer has: Melting point in the range of 110 to 140 °C, determined by differential scanning calorimetry according to ISO 11357-3; MFR2, measured according to ISO 1133 at 230°C and 2.16 kg, in the range of 0.5 to 4.0 g / 10 min; and, The total C2 content in the range of 1 to 10 wt.% based on the total weight of the C2C3 random copolymer; B) 5.0 to 30.0 wt.% LDPE based on the total weight of the polymer composition; wherein the LDPE has: According to ISO 1183, the concentration is between 917 and 921 kg / m³. 3 Density within the range; and, MFR2 was determined according to ISO 1133 at 190°C and 2.16 kg in the range of 6.5 to 10.0 g / 10 min. C) 0.1 to 5.0 wt.% of additives based on the total weight of the polymer composition, wherein the additives are selected from one or more of slip agents, acid scavengers, UV stabilizers, pigments, antioxidants, additive carriers, nucleating agents, and mixtures thereof; The condition is that the sum of the weight ratios of components A), B), and C) is 100 wt.%.

9. An article comprising the polymer composition as described in any one of claims 1 to 8.

10. The article of claim 9, wherein the article is a blown film.

11. The article of claim 10, characterized in that, The sealing initiation temperature for a 50 μm thick blown film is in the range of 80°C to below 120°C; and / or, The crystallization temperature of a 50 μm thick blown film, measured by differential scanning calorimetry according to ISO 11357-3, is 80 to 95 °C; and / or, The blown film has two melting points, wherein the first melting point, determined by differential scanning calorimetry according to ISO 11357-3, is in the range of 110 to 130°C, and the second melting point, determined by differential scanning calorimetry according to ISO 11357-3, is in the range of 100 to 115°C.

12. The article of manufacture according to claim 10 or 11, characterized in that, The blown film has a tensile modulus in the longitudinal and transverse directions ranging from 200 to 1000 MPa, measured according to ISO 527-3 on a 50 μm thick blown film at 23°C; and / or, The blown film has a dart impact strength in the range of 20 to 2000 g, measured according to ASTM D1709 Method A on a blown film with a thickness of 50 μm; and / or, The blown film has an Elmendorf tear strength in the longitudinal direction ranging from 1.0 N / mm to 50.0 N / mm, as measured according to ISO 6383 / 2; and / or, The blown film has an Elmendorf tear strength in the transverse direction, ranging from 5.0 N / mm to 100.0 N / mm, as measured according to ISO 6383 / 2.

13. The article of claim 10, characterized in that, The blown film has a haze of less than 4.2% as measured according to ASTM D1003-00 for a blown film with a thickness of 50 μm.

14. A flexible packaging system selected from bags used for food and pharmaceutical packaging, comprising articles according to any one of claims 10 to 13.

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