Polymer processing aid comprising a silicone polyether

Abstract

A method of reducing or eliminating melt fracture during extrusion includes blending an ethylene-based polymer having a melt index (I2) of less than 2.0 decigram / minute (dg / min) with a polymer processing aid (PPA) to remove the melt fracture during extrusion, wherein the PPA comprises a silicone polyether.

Description

[0001] Cross-reference of related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 626,250, filed January 29, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates in general to polymer processing aids. Background Technology

[0004] Plastics are used in a wide range of industrial applications, including packaging, construction, and wires and cables. However, many plastics suffer from melt fracture during extrusion, a phenomenon in which the plastic surface becomes distorted due to fluctuations or irregularities. Some types of melt fracture (such as sharkskin melt fracture) affect the surface of plastics by causing irregular and sometimes scaly surface textures, which can reduce the surface gloss.

[0005] Conventional methods for preventing melt fracture in polyethylene include the use of processing aids based on fluoropolymers. However, concerns about the potential persistence of fluorinated compounds in the environment have led to limitations on these materials, including fluoropolymer-based processing aids. Therefore, there is a need for improved formulations and methods that can reduce melt fracture while also alleviating concerns about environmental persistence. Summary of the Invention

[0006] Embodiments of this disclosure address these and other needs by providing a method for reducing or eliminating melt fracture during extrusion, the method comprising blending an ethylene-based polymer having a melt index (I2) of less than 2.0 dg / min with a polymer processing aid (PPA) to remove the melt fracture during extrusion, wherein the PPA comprises a silicone polyether.

[0007] According to one or more embodiments of this disclosure, articles can be produced by the above method.

[0008] Further features and advantages will be set forth in the following detailed description, and in part will be apparent to those skilled in the art from those description or will be recognized by practice of the embodiments described herein, including the following detailed description in addition to the claims.

[0009] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Detailed Implementation

[0010] Implementations of methods for reducing or eliminating melt fracture during extrusion will now be described in detail, including blending an ethylene-based polymer having a melt index (I2) of less than 2.0 dg / min with a polymer processing aid (PPA) to remove melt fracture during extrusion, wherein the PPA comprises a silicone polyether.

[0011] As used herein, the term "polymer" can refer to a polymeric compound prepared by polymerizing monomers of the same or different types. Therefore, the general term polymer encompasses the term "homopolymer," which is generally used to refer to a polymer prepared from only one type of monomer; and "copolymer," which refers to a polymer prepared from two or more different monomers. As used herein, the term "interpolymer" refers to a polymer prepared by polymerizing at least two different types of monomers. Therefore, the general term interpolymer includes copolymers and polymers prepared from more than two different types of monomers (such as terpolymers).

[0012] The terms “blend” and “polymer blend” mean a composition of two or more polymers. Such blends may or may not be miscible. Such blends may or may not be phase-separated. Such blends may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and any other methods known in the art. Blends are not laminates, but one or more layers of a laminate may contain blends. Such blends can be prepared as dry blends, in-situ formed (e.g., in a reactor), melt blends, or using other techniques known to those skilled in the art.

[0013] As used in this disclosure, the term "polyethylene" or "ethylene-based polymer" can refer to a polymer comprising more than 50 mol% of units derived from ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of ethylene-based polymers known in the art include low-density polyethylene (LDPE); linear low-density polyethylene (LLDPE); ultra-low-density polyethylene (ULDPE); very low-density polyethylene (VLDPE); single-point catalytic linear low-density polyethylene, including both linear and substantially linear low-density resins (m-LLDPE); medium-density polyethylene (MDPE); and high-density polyethylene (HDPE).

[0014] The term "LLDPE" encompasses two types of resins manufactured using conventional Ziegler-Natta catalyst systems and chromium-based catalyst systems, as well as monoparticle catalysts (including, but not limited to, bismetallocene catalysts (sometimes referred to as "m-LLDPE"), geometry-defined catalysts (CGC), and molecular catalysts). The resins include linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPE comprises fewer long-chain branchings than LDPE, and LLDPE comprises substantially linear ethylene polymers, further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923, and 5,733,155; homogeneously branched linear ethylene polymer compositions, such as those in U.S. Patent No. 3,645,992; non-homogeneously branched ethylene polymers, such as those prepared according to the method disclosed in U.S. Patent No. 4,076,698; and / or blends thereof (such as those disclosed in U.S. 3,914,342 or U.S. 5,854,045). LLDPE can be manufactured by gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0015] As used herein, "fluoropolymer" refers to a polymeric compound containing fluorine and is intended to be interpreted broadly to include substances that may be referred to as oligomers. By way of non-limiting example, a fluoropolymer may comprise a molecule containing at least three, at least four, at least five, or at least six fluorine-containing units.

[0016] As used in this article, “substantially free” means containing less than 50 ppmw.

[0017] As used herein, “melt fracture” refers to the formation of defects in polymer extrudates under various processing conditions. Defects can be any deviation from a smooth, glossy, regular extrudate.

[0018] As used in this article, “parts per million” or “ppm” refers to parts per million by weight.

[0019] As used herein, "polymer melt" refers to a polymer or polymer blend at a temperature above its glass transition temperature (i.e., below which the physical properties of the polymer change to a glassy or crystalline state) and generally above its melting temperature. Polymer melts can exist as high-viscosity liquids and can exhibit non-Newtonian or viscoelastic properties.

[0020] As used in this article, "polyether" means polyether derived from the formula —(C n H 2n(O) – represents a polyoxyethylene copolymer, where n is 2 to 4, including the end values. The polyoxyethylene copolymer units typically include ethylene oxide units – (C2H4O) –, propylene oxide units – (C3H6O) –, butene oxide units – (C4H8O) – or mixtures thereof. The ethylene oxide units can be arranged in any manner to form a homopolymer, block copolymer, or random copolymer structure, but typically form homopolymer or random copolymer groups. In some embodiments, the polyoxyethylene contains both ethylene oxide units (C2H4O) and propylene oxide units (C3H6O) in the random copolymer. In some embodiments, the polyoxyethylene is a homopolymer containing only ethylene oxide units (C2H4O). In specific embodiments, the polyether can be selected from those having the following average formula: R 1 O(C n H 2n O) m R 2 (Equation I); where n is 2 to 4, including the end values, m is greater than 2, and R 1 It is a monovalent terminal unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms, R 2 It is R 1 The polyether contains hydrogen, acetyl, or monovalent hydrocarbon groups containing 1 to 8 carbon atoms. In Formula I, the polyether may be end-capped with an unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms, such as an alkenyl or alkynyl group. When R 2 ═R 1 Furthermore, the polyether may also contain unsaturated aliphatic hydrocarbon groups at each end, which, if the organohydrosiloxane contains at least two SiH units, particularly the terminal SiH units, will result in the formation of (AB)n-type silicone polyethers. Further details and examples of polyethers are provided in U.S. Patent Nos. 6,987,157 and 8,008,407, which are incorporated herein by reference in their entirety. Polyethers may include polyethylene glycol (PEG).

[0021] As used herein, "silicone" is an organohydrosiloxane, which is any organopolysiloxane containing at least one silicon-bonded hydrogen atom (SiH) per molecule. Organopolysiloxanes are well known in the art and are generally specified as containing any amount or combination of (R3SiO) 0.5 ) 、 (R2SiO), (RSiO) 1.5 (SiO2)siloxane units, where R is independently an organic group or a hydrocarbon group. When in an organopolysiloxane (R3SiO2) 0.5 (R2SiO), (RSiO) 1.5When R in the siloxy unit is methyl, the siloxy unit is typically designated as M, D, and T units, respectively, while the (SiO2)siloxy unit is designated as Q unit. Organohydrosiloxanes have similar structures, but possess at least one SiH on the siloxy unit. Therefore, the methyl-based siloxy unit in an organohydrosiloxane can be represented as containing "M"... H "Silicone-oxygen unit (R2HSiO)" 0.5 ), "D H "Silicone-oxygen unit (RHSiO), "T H "Silicone-oxygen unit (HSiO)" 1.5 The organohydrosiloxanes that can be used in this invention may include any number of M, M H D, D H T, T H Alternatively, a Q-siloxy unit may be used, provided that at least one siloxy unit contains SiH. Further details and examples of silicones are provided in U.S. Patent No. 8,008,407, which is incorporated herein by reference in its entirety. Silicones may comprise polydimethylsiloxane (PDMS).

[0022] "Silicone polyether" is the reaction product of silicone and polyether as defined above, specifically, it is formed by formula R 1 —(C n H 2n O)—R 2 The reaction product of the polyoxyethylene copolymer is represented, where n is 2 to 4, including the end value, and R 1 It is a monovalent terminal unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms, and R 2 It is an organopolysiloxane containing hydrogen, an acetyl group, a monovalent terminal unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms or a monovalent hydrocarbon group containing 1 to 8 carbon atoms; and an organopolysiloxane containing at least one silicon-bonded hydrogen atom (SiH) per molecule.

[0023] Alternatively, the silicone polyether may comprise a linear silicone backbone having side-chain polyether groups. The silicone polyether may have the unit formula: (R3SiO 1 / 2 )2(R2SiO 2 / 2 ) x (RR'SiO 2 / 2 ) yIn this unit formula, the subscript x is an integer with values ​​from 1 to 500, alternatively from 1 to 200, alternatively from 1 to 100, alternatively from 1 to 50, alternatively from 1 to 10, alternatively from 3 to 8, and alternatively from 5. The subscript y is an integer with values ​​from 1 to 100, alternatively from 1 to 50, alternatively from 1 to 10, alternatively from 1 to 5, alternatively from 2 to 5, and alternatively from 3.5. Each R is an independently chosen monovalent hydrocarbon group containing 1 to 30 carbon atoms. Alternatively, each R can be an alkyl group and alternatively a methyl group. Each R' is a polyether group of the following formula: , where R 3 It is a divalent hydrocarbon group having 2 to 12 carbon atoms, or alternatively 2 to 5 carbon atoms; each subscript n is independently 2, 3, or 4, or alternatively 2 or 3; and R 2 It is a hydrogen group, an acetyl group, a monovalent terminal unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms, or a monovalent hydrocarbon group containing 1 to 8 carbon atoms. Alternatively, R 2 It could be hydrogen. R 3 The hydrogen atoms bonded to silicon on the aforementioned organohydrosiloxanes and R 1 It is formed by the hydrosilylation reaction of the terminal unsaturated aliphatic hydrocarbon groups of the polyether of formula I.

[0024] In various embodiments, methods for removing melt fracture during extrusion include blending an ethylene-based polymer with a polymer processing aid (PPA) to remove melt fracture during extrusion. In one or more embodiments, the PPA is dry-blended with the ethylene-based polymer. In one or more embodiments, the PPA or its masterbatch is blended with an ethylene-based polymer melt.

[0025] Various compositions are considered suitable for ethylene-based polymers. In one or more embodiments, the ethylene-based polymer may comprise linear low-density polyethylene (LLDPE). In embodiments, the ethylene-based polymer may comprise a melt index (I2) of less than 2.0 dg / min as measured according to ASTM D-1238 (190°C / 2.16 kg). In the implementation scheme, the ethylene-based polymer may contain 0.05 dg / 10 mins to 2.0 dg / 10 mins, 0.05 dg / 10 mins to 1.8 dg / 10 mins, 0.05 dg / 10 mins to 1.6 dg / 10 mins, 0.05 dg / 10 mins to 1.5 dg / 10 mins, 0.1 dg / 10 mins to 2.0 dg / 10 mins, 0.1 dg / 10 mins to 1.8 dg / 10 mins, 0.1 dg / 10 mins to 1.6 dg / 10 mins, 0.1 dg / 10 mins to 1.5 dg / 10 mins, 0.1 dg / 10 mins to 1.4 dg / 10 mins, 0.5 dg / 10 mins, etc. Melt index of g / 10mins to 2.0 dg / 10mins, 0.5 dg / 10mins to 1.8 dg / 10mins, 0.5 dg / 10mins to 1.6 dg / 10mins, 0.5 dg / 10mins to 1.5 dg / 10mins, 0.5 dg / 10mins to 1.4 dg / 10mins, 1.0 dg / 10mins to 2.0 dg / 10mins, 1.0 dg / 10mins to 1.8 dg / 10mins, 1.0 dg / 10mins to 1.6 dg / 10mins, 1.0 dg / 10mins to 1.5 dg / 10mins, or 1.0 dg / 10mins to 1.4 dg / 10mins. In a further embodiment, the ethylene-based polymer may have a density of 0.850 g / cc to 0.950 g / cc, 0.875 g / cc to 0.925 g / cc, 0.890 g / cc to 0.915 g / cc, or 0.895 g / cc to 0.910 g / cc.

[0026] As described above, the PPA comprises a silicone polyether. In one or more embodiments, the silicone polyether may comprise a kinematic viscosity of 100 centistokes (cSt) to 100,000 cSt. In embodiments, the silicone polyether may include 100 cSt to 100,000 cSt, 150 cSt to 100,000 cSt, 200 cSt to 100,000 cSt, 250 cSt to 100,000 cSt, 275 cSt to 100,000 cSt, 280 cSt to 100,000 cSt, 285 cSt to 100,000 cSt, 100 cSt to 75,000 cSt, 150 cSt to 75,000 cSt, 200 cSt to 75,000 cSt, 250 cSt to 75,000 cSt, 275 cSt to 75,000 cSt, 280 cSt to 75,000 cSt. kinematic viscosities of cSt, 100 cSt to 50,000 cSt, 150 cSt to 50,000 cSt, 200 cSt to 50,000 cSt, 250 cSt to 50,000 cSt, 100 cSt to 25,000 cSt, 150 cSt to 25,000 cSt, 200 cSt to 25,000 cSt, 100 cSt to 10,000 cSt, 150 cSt to 10,000 cSt, 100 cSt to 7,500 cSt, 100 cSt to 5,000 cSt, 100 cSt to 3,500 cSt, 100 cSt to 1,000 cSt, or 100 cSt to 500 cSt.

[0027] In some embodiments, the PPA further comprises free silicone, free polyether, or a combination thereof. In some embodiments, the free polyether may be free PEG. "Free PEG" or "free polyether" does not react with silicone. In some embodiments, the free silicone may be PDMS. "Free PDMS" or "free silicone" does not react with polyether. In one or more embodiments, the PPA comprises free polyether at concentrations of 0 ppm to 2000 ppm, 0 ppm to 1500 ppm, 0 ppm to 1000 ppm, 100 ppm to 2000 ppm, 100 ppm to 1500 ppm, or 100 ppm to 1000 ppm. In one or more embodiments, the PPA may comprise free polyether having an average molecular weight (MW) of 1,000 g / mol to 100,000 g / mol. In the embodiments, the free polyether may have an average MW of 100 g / mol to 40,000 g / mol, 250 g / mol to 40,000 g / mol, 500 g / mol to 40,000 g / mol, 750 g / mol to 40,000 g / mol, 1,000 g / mol to 40,000 g / mol, 2,500 g / mol to 40,000 g / mol, 5,000 g / mol to 40,000 g / mol, 7,500 g / mol to 40,000 g / mol, 10,000 g / mol to 40,000 g / mol, or 25,000 g / mol to 40,000 g / mol.

[0028] In some embodiments, the PPA comprises a mixture of silicone polyether, free silicone, and free polyether, wherein the majority of the mixture is silicone polyether by weight. In some embodiments, the PPA comprises a mixture of silicone polyether, free silicone, and free polyether, wherein the silicone polyether constitutes more than 50% to 100% by weight, 55% to 100% by weight, 60% to 100% by weight, 65% to 100% by weight, more than 50% to 95% by weight, 55% to 95% by weight, 60% to 95% by weight, 65% to 95% by weight, more than 50% to 90% by weight, and 55% to 90% by weight. 60% to 90% by weight, 65% to 90% by weight, greater than 50% to 85% by weight, 55% to 85% by weight, 60% to 85% by weight, 65% to 85% by weight, greater than 50% to 80% by weight, 55% to 80% by weight, 60% to 80% by weight, 65% to 80% by weight, greater than 50% to 75% by weight, 55% to 75% by weight, 60% to 75% by weight or 65% to 75% by weight.

[0029] In one or more embodiments, the PPA may be substantially free of fluoropolymers. In embodiments, the PPA may contain less than 50 ppmw, less than 40 ppmw, less than 30 ppmw, less than 20 ppmw, less than 10 ppmw, less than 5 ppmw, less than 2 ppmw, or less than 1 ppmw of fluoropolymers.

[0030] For PPAs, additional optional additives are anticipated. In some embodiments, the PPA may include one or more other additives. Non-limiting examples of suitable other additives include antioxidants, antistatic agents, stabilizers, nucleating agents, colorants, pigments, ultraviolet (UV) absorbers or stabilizers, flame retardants, compatibilizers, plasticizers, fillers, processing aids, antifogging additives, crosslinking agents (e.g., peroxides), and combinations thereof. This document includes and discloses all individual values ​​and sub-ranges from 0 wt% to 3 wt%; for example, the total amount of additives in a polymer blend may be within the lower limits of 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, or 4.5 wt%, or the upper limits of 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt%.

[0031] Various process procedures are considered suitable for the production of PPA. For example, it is contemplated that PPA components be added in various sequences. In some embodiments, PPA may be directly melt-blended into an ethylene-based polymer. In one or more embodiments, PPA may be added to an ethylene-based polymer via a masterbatch. In embodiments, generating the masterbatch may include compounding a polyethylene resin with PPA. The masterbatch may be combined with a base resin to reduce melt fracture in the base resin during extrusion, thereby producing finished products, such as strip extrusions, blown films, cables, wires, pipes, or tubes. The masterbatch may be melt-blended or dry-blended with the base resin before or during extrusion to produce articles with reduced melt fracture, such as strip extrusions, blown films, cables, wires, pipes, or tubes. The base resin may include an ethylene-based polymer, such as LLDPE.

[0032] In various embodiments, PPA may be provided in the polymer masterbatch. In one or more embodiments, the polymer masterbatch may include 1 wt.% to less than 15 wt% of PPA. In some embodiments, the polymer masterbatch may include 1 wt% to less than 15 wt%, 2 wt% to less than 15 wt%, 3 wt% to less than 15 wt%, 5 wt% to less than 15 wt%, 10 wt% to less than 15 wt%, 1 wt% to 14 wt%, 2 wt% to 14 wt%, 3 wt% to 14 wt%, 5 wt% to 14 wt%, 10 wt% to 14 wt%, 1 wt% to 12 wt%, 2 wt% to 12 wt%, 3 wt% to 12 wt%, 5 wt% to 12 wt%, 10 wt% to 12 wt%, 1 wt% to 10 wt%, 2 wt% to 10 wt%, 3 wt% to 10 wt%, or 5 wt% to 10 wt% of PPA.

[0033] In one or more embodiments, the PPA can remove melt fracture within 120 minutes or less. In embodiments, the PPA can remove melt fracture within 120 minutes or less, 110 minutes or less, 100 minutes or less, or 90 minutes or less.

[0034] Products

[0035] In one or more embodiments, the article may be produced from the base resin and PPA described herein. The article may include a film, such as a blown film. The film may be a single-layer or multi-layer film. Articles containing films may include non-rigid packaging, such as flexible packaging, pouches, stand-up pouches, etc. Articles may also include rigid packaging. Articles may also include tubes, conduits, wires, cables, tapes, or pipes.

[0036] In various embodiments, articles produced according to the methods disclosed and described herein, such as blown films, may include 200 ppm to 800 ppm of silicone polyether. In some embodiments, articles produced according to the methods disclosed and described herein, such as blown films, may include 200 ppm to 800 ppm, 400 ppm to 800 ppm, 600 ppm to 800 ppm, 200 ppm to 600 ppm, 400 ppm to 600 ppm, or 200 ppm to 400 ppm of silicone polyether.

[0037] Test methods

[0038] Melt index (190°C, 2.16 kg, "I2") test method: ASTM D 1238-13, "Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer," was used at 190°C and 2.16 kg. Results are reported in grams eluted per 10 minutes (dg / 10min).

[0039] Kinematic viscosity was measured using an MCR 301 rheometer, commercially available from Anton Paar. The rheometer was equipped with a 25 mm stainless steel conical plate clamp and operated at 25°C. Steady-state shear measurements were performed at shear rates ranging from 0.1 s⁻¹ to 500 s⁻¹. The material was allowed to equilibrate for at least 5 minutes before each measurement. Kinematic viscosity was measured at 0.1 s⁻¹. -1 up to 10s -1 The average viscosity at the shear rate.

[0040] Example

[0041] The following embodiments are provided by way of illustration and are presented in a manner that would be recognized by those skilled in the art, and are not intended to limit the whole of this disclosure or the appended claims.

[0042] The following compositions are used in the following examples.

[0043] LLDPE-1 has a melt index (I2) of 0.5 g / 10 mins and a density of 0.905 g / cc.

[0044] Polyether-1 is CARBOWAX, which is commercially available from Dow Chemical Company (Dow Inc). ™ 600 PEG, with a molecular weight of 570 g / mol to 630 g / mol.

[0045] PDMS-1 is a nonfunctionalized PDMS with a kinematic viscosity of 350 cSt.

[0046] PDMS-2 is a silicone polyether with a kinematic viscosity of 278 cSt.

[0047] DOWLEX ™ 2047G, is a polyethylene resin with a content of 0.917 g / cm³. 3 The density and I2 of 2.3 g / 10 min.

[0048] Example 1 - Production of LLDPE-1 Resin

[0049] LLDPE-1 was prepared according to Inventive Example 1 described in U.S. Patent No. 8,372,931, the entire contents of which are hereby incorporated by reference.

[0050] Example 2 - Production of PDMS-2

[0051] PDMS-2 was prepared according to method 1 described in U.S. Patent No. 8,008,407, the entire contents of which are hereby incorporated by reference, polyoxyethylene and trimethylsiloxy-terminated dimethylmethyl(polyether)siloxane (MD) x -D R y -M), where the polyether (R) is a hydroxyl-terminated polyoxyethylene group, i.e., -(CH2)3O(EO). m H. PDMS-2 comprises 33.5 wt% silicone and 66.5 wt% polyether. The molecular weight (MW) of PDMS-2 is 3,703 g / mol. A mixture comprising 78 wt% PDMS-2, 20 wt% polyether and 2 wt% silicone was then prepared.

[0052] Example 3 – Production of PPA Masterbatch

[0053] Additive masterbatches containing a mixture of PDMS-1 or PDMS-2 were prepared in a 26mm diameter twin-screw extruder (TSE) with a 48 L / D capacity from Coperion. DOWLEX, used as the base resin, was fed using a Ktron pellet feeder. ™ 2047G was fed into the main extruder hopper. If applicable, polyether-1 powder was also fed into the main hopper using a Ktron powder feeder. If applicable, a mixture of liquid PDMS-1 or liquid PDMS-2 was injected using an ISCO pump at 5.25 mL / min. The ISCO pump flow rate was 1.68 mL / min. The polymer melt was extruded using a 3.2 mm, 2-hole die and granulated using a Conair granulator. Process conditions are presented in Table 1.

[0054] Table 1: Process Conditions for Masterbatch Production

[0055]

[0056] Example 4 - Production of Strip Extrusions

[0057] Single-layer PE strip extrusions were prepared using a twin-screw extruder (TSE). The TSE was a ZSK 18MEGAlab TSE from Coperlon. The TSE was an 18mm co-rotating TSE with an L / D ratio of 40:1 and a Do / Di ratio of 1.55. The apparent shear rate used in the die was 151 / s, and the die used was an unpolished slit die with a slit width, die gap, and forming section length of 10mm, 2mm, and 10mm, respectively.

[0058] The base resin, LLDPE-1, was added to the feed hopper of the TSE without any processing aids until the flow stabilized, resulting in melt breakup in the film. Then, a PPA masterbatch prepared according to Example 3 and polyether-1 (if used) was dry-blended with the base resin and fed into the same hopper of the TSE to produce a strip extrusion with polymer processing aids (PPA). The processing conditions used in the extruder are listed in Table 2.

[0059] Table 2: Processing Conditions

[0060]

[0061] When each formulation was introduced into the extruder after the process had stabilized, a timer was started. If melt fracture was not cleared after 120 minutes, the timer was stopped. Table 5 shows the time to clear melt fracture and the concentrations of PDMS and polyether in the resulting extruded strip. After each formulation, the extruder was purged with the base resin until melt fracture was completely rebuilt; this was also visually confirmed by the stabilization of processing conditions (extruder torque, pressure).

[0062] Table 3: Concentration of PDMS and polyether and time to remove melt fracture

[0063]

[0064] As shown in Table 3, sample IE1 cleared melt fracture within 80 minutes. Conversely, samples CE1 and CE2, which do not contain silicone polyether, failed to clear melt fracture within 120 minutes or less. This is particularly noteworthy because samples CE2 and IE1 both contain the same total concentration of PDMS and polyether. Therefore, sample IE1 demonstrates the practicality of using silicone polyether as a polymer processing aid.

[0065] The subject matter of this disclosure has been described in detail and with reference to specific embodiments. It should be understood that any detailed description of a component or feature of an embodiment does not necessarily imply that such component or feature is necessary for a particular embodiment or any other embodiment. Furthermore, it will be apparent to those skilled in the art that various modifications and changes can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

[0066] It should be noted that one or more of the appended claims use the term "wherein" as a transitional expression. For the purpose of defining this technology, it should be noted that this term is introduced in the claims as an open transitional phrase used to introduce a description of a series of features of the structure, and should be interpreted in a similar manner to the more commonly used open prepositional term "comprising".

[0067] It should be understood that when the first component is described as "containing" the second component, it is anticipated that in the embodiments, the first component is "composed of" or "substantially composed of" the second component. It should also be understood that when the first component is described as "containing" the second component, it is anticipated that in the embodiments, the first component may contain at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% of the second component (where % may be weight % or molar %).

[0068] It should also be noted that references to “at least one” components, elements, etc. in this article should not be used to generate alternative uses of the article “a / an” and should be limited to inferences about a single component, element, etc.

Claims

1. A method for reducing or eliminating melt fracture during extrusion, the method comprising: An ethylene-based polymer having a melt index (I2) of less than 2.0 dg / min is blended with a polymer processing aid (PPA) to remove melt fracture during extrusion, wherein the PPA comprises a silicone polyether, which is a reaction product of the following substances: From formula R 1 —(C n H 2n O)—R 2 The polyoxyethylene copolymer represents, wherein: n is 2 to 4, including the end values; R 1 It is a monovalent terminal unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms; and R 2 It is hydrogen, an acetyl group, a monovalent terminal unsaturated aliphatic hydrocarbon group containing 2 to 12 carbon atoms, or a monovalent hydrocarbon group containing 1 to 8 carbon atoms; and Organopolysiloxanes containing at least one silicon-bonded hydrogen atom (SiH) per molecule.

2. The method according to claim 1, wherein the silicone polyether has a kinematic viscosity of 100 cSt to 100,000 cSt.

3. The method according to claim 1 or claim 2, wherein the ethylene-based polymer has a melt index (I2) of 0.05 dg / min to 1.5 dg / min.

4. The method according to any one of claims 1 to 3, wherein the PPA is provided in a polymer masterbatch.

5. The method of claim 4, wherein the polymer masterbatch comprises 1% by weight to less than 15% by weight of PPA.

6. The method according to any one of claims 1 to 5, wherein the method further comprises obtaining an extruded product, wherein the extruded product comprises 200 ppm to 8000 ppm of silicone polyether.

7. The method according to any one of claims 1 to 6, wherein the PPA or its masterbatch is dry blended with the ethylene-based polymer.

8. The method according to any one of claims 1 to 6, wherein the PPA or its masterbatch is blended with the ethylene-based polymer melt.

9. The method according to any one of claims 1 to 8, wherein the ethylene-based polymer comprises LLDPE.

10. An article of manufacture produced by the method according to any one of claims 1 to 9.

11. The article of claim 10, wherein the article is a blown film, cable, wire, tube or pipe.

12. Use of a polymer processing aid (PPA) to remove melt fracture during extrusion, the use comprising blending an ethylene-based polymer having a melt index (I2) of less than 2.0 dg / min with the PPA, wherein the PPA comprises a silicone polyether.

13. Use of the PPA according to claim 12, wherein the silicone polyether has a kinematic viscosity of 100 cSt to 100,000 cSt.

14. Use of the PPA according to claim 12 or claim 13, wherein the ethylene-based polymer comprises LLDPE.

15. Use of the PPA according to any one of claims 12 to 14, wherein the PPA is provided in a polymer masterbatch, wherein the polymer masterbatch comprises 1% by weight to less than 15% by weight of the PPA.

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