Low viscosity functionalized ethylene copolymers

Abstract

The present disclosure provides embodiments of an epoxy-functionalized ethylene-based polymer and a method for manufacturing, which may include extruding a reactive mixture to form the epoxy-functionalized ethylene-based polymer, where the reactive mixture includes: an ethylene-based polymer having a molecular weight of less than or equal to 50,000 at 177 DEG C, and an ethylene-based polymer having a molecular weight of less than or equal to 50,000 at 177 DEG C; a viscosity of 20,000 cP to 20,000 cP; an epoxy functional monomer; a peroxide; and a vinyl terminated polyfunctional aid, the vinyl terminated polyfunctional aid having a functionality of 2 or more.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 402,764, filed on August 31, 2023, the entire disclosure of which is hereby incorporated by reference into this document. Technical Field

[0003]

[0013] Embodiments described herein are generally directed to a method of grafting epoxy functional groups onto low viscosity ethylene-based copolymers. Background Art

[0004] Grafted or functionalized low viscosity ethylene copolymers can be used as recycling compatibilizers.Epoxy-functionalized ethylene copolymers are of interest for these applications due, at least in part, to the reaction between the epoxy groups of the epoxy-functionalized ethylene copolymers and acid groups (eg, in polyesters).

[0005] Common epoxy-functional monomers grafted onto polyolefins or polyolefin copolymers or block copolymers are glycidyl acrylate, glycidyl methacrylate (GMA), and allyl glycidyl ether (AGE). However, other epoxy-functional vinyl monomers can also be grafted onto polyolefins or polyolefin copolymers or block copolymers. Typically, grafting is performed using peroxide initiation. However, low grafting efficiency and the tendency of monomers to homopolymerize (rather than graft) and participate in other side reactions make it challenging to graft epoxy functional groups onto ethylene copolymers. In addition, due to the low viscosity of ethylene copolymers (e.g., less than 50,000 cP at 177°C), an appropriate extruder and peroxide combination is required to achieve the correct graft structure and complete the reaction.

[0006] Polyethylene containing GMA functionality can be prepared via copolymerization in a reactor, but there is a lower limit on the viscosity of the resin (or an upper limit on the melt index of the resin). This lower limit is problematic because low viscosity is required to achieve good compatibilization in packaging recycling.

[0007] Therefore, there is a need for a more efficient process for grafting epoxy functional monomers onto low viscosity polyolefins that avoids the low viscosity limitations that exist for copolymerization processes. Summary of the invention

[0008] Embodiments of the present disclosure meet the above needs by utilizing an adjuvant during the grafting process that enhances the grafting reaction of epoxy functional monomers onto low viscosity polyolefins. It has been discovered that specific adjuvants containing vinyl groups facilitate the grafting of epoxy functional monomers onto low viscosity polyolefins while improving the grafting level and grafting efficiency and minimizing homopolymer formation.

[0009] In one embodiment, the grafting method of the present disclosure is directed to the manufacture of epoxy-functionalized ethylene polymers, the method comprising: extruding a reactive mixture to form an epoxy-functionalized ethylene polymer, wherein the reactive mixture comprises: an ethylene polymer having a viscosity of less than or equal to 50,000 cP at 177°C; an epoxy-functional monomer; a peroxide; and a vinyl-terminated multifunctional coagent having a functionality of 2 or greater.

[0010] These and other embodiments are described in more detail in the detailed description that follows. DETAILED DESCRIPTION

[0011] Specific embodiments of the present application will now be described. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art.

[0012] As described above, the present disclosure provides a method for producing an epoxy-functionalized ethylene polymer, the method comprising: extruding a reactive mixture to form an epoxy-functionalized ethylene polymer, wherein the reactive mixture comprises: an ethylene polymer having a viscosity of less than or equal to 50,000 cP at 177°C; an epoxy-functional monomer; a peroxide; and a vinyl-terminated multifunctional auxiliary agent, the vinyl-terminated multifunctional auxiliary agent having a functionality of 2 or greater.

[0013] Ethylene polymers

[0014] In one embodiment, the ethylene-based polymer is an ethylene / α-olefin interpolymer, wherein the α-olefin is a C3-C20 α-olefin or a C3-C10 α-olefin. In one embodiment, the ethylene-based polymer is an ethylene / α-olefin copolymer, wherein the α-olefin is a C3-C20 α-olefin or a C3-C10 α-olefin.

[0015] In one embodiment, reactive mixture comprises 80 wt % to 97 wt % ethylene polymers. In some embodiments, reactive mixture comprises 83 wt % to 97 wt % ethylene polymers, 85 wt % to 97 wt % ethylene polymers, 85 wt % to 96 wt % ethylene polymers, 87 wt % to 96 wt % ethylene polymers, 88 wt % to 96 wt % ethylene polymers, 89 wt % to 96 wt % ethylene polymers or 89.5 wt % to 96 wt % ethylene polymers. All individual values ​​and subranges of ethylene polymers from 80 wt % to 97 wt % are included herein and disclosed herein.

[0016] In one embodiment, the ethylene-based polymer has a melt viscosity of less than or equal to 50,000 cP, or less than or equal to 45,000 cP, or less than or equal to 40,000 cP at 350°F (177°C). In one embodiment, the ethylene-based polymer has a melt viscosity of less than or equal to 30,000 cP, less than or equal to 25,000 cP, less than or equal to 20,000 cP, or less than or equal to 15,000 cP at 350°F (177°C). In one embodiment, the ethylene-based polymer has a melt viscosity of greater than or equal to 1,000 cP, greater than or equal to 2,000 cP, greater than or equal to 3,000 cP, greater than or equal to 4,000 cP, or greater than or equal to 5,000 cP at 350°F (177°C). In one embodiment, the viscosity of the ethylene-based polymer at 350°F (177°C) is 5,000 cP to 50,000 cP. For purposes of this disclosure, a "low viscosity" ethylene-based polymer refers to an ethylene-based polymer having a melt viscosity of less than or equal to 50,000 cP at 350°F (177°C).

[0017] In one embodiment, the ethylene polymer has a molecular weight less than or equal to 0.900 g / cc, less than or equal to 0.895 g / cc, less than or equal to 0.890 g / cc, less than or equal to 0.885 g / cc, less than or equal to 0.880 g / cc, or less than or equal to 0.875 g / cc (g / cc = g / cm 3 ). In one embodiment, the ethylene polymer has a density greater than or equal to 0.850 g / cc, greater than or equal to 0.855 g / cc, greater than or equal to 0.860 g / cc, or greater than or equal to 0.865 g / cc. In one embodiment, the ethylene polymer has a density of 0.850 g / cc to 0.900 g / cc.

[0018] Epoxy Functional Monomers

[0019] In one embodiment, the epoxy functional monomer comprises one or more of glycidyl acrylate, glycidyl methacrylate (GMA) and allyl glycidyl ether (AGE). Other suitable epoxy functional monomers include, but are not limited to, (3,4-epoxycyclohexyl) methyl acrylate, (3,4-epoxycyclohexyl) methyl acrylate and 1,2-epoxy-4-vinylcyclohexane.

[0020] In one embodiment, the reactive mixture comprises 0.3 wt % to 10.0 wt % of epoxy functional monomers, based on the total weight of the reactive mixture. In some embodiments, the reactive mixture may comprise 2.5 wt % to 9.5 wt % of epoxy functional monomers, 2.5 wt % to 9.0 wt % of epoxy functional monomers, 3.0 wt % to 9.0 wt % of epoxy functional monomers, 3.0 wt % to 8.5 wt % of epoxy functional monomers, or 3.0 wt % to 8.0 wt % of epoxy functional monomers. All individual values ​​and subranges of epoxy functional monomers from 0.3 wt % to 10.0 wt % are included herein and disclosed herein.

[0021] Additives

[0022] In one embodiment, the reactive mixture comprises 0.1 wt % to 5.0 wt % of a vinyl terminated multifunctional auxiliary. In some embodiments, the reactive mixture may comprise 0.6 wt % to 4.6 wt % of a vinyl terminated multifunctional auxiliary, 0.7 wt % to 4.2 wt % of a vinyl terminated multifunctional auxiliary, 0.8 wt % to 3.8 wt % of a vinyl terminated multifunctional auxiliary, 0.9 wt % to 3.4 wt % of a vinyl terminated multifunctional auxiliary, 1.0 wt % to 3.0 wt % of a vinyl terminated multifunctional auxiliary, or 1.1 wt % to 2.6 wt % of a vinyl terminated multifunctional auxiliary. All individual values ​​and subranges of vinyl terminated multifunctional auxiliary from 0.1 wt % to 5.0 wt % are included herein and disclosed herein.

[0023] In one embodiment, the vinyl terminated multifunctional auxiliary comprises divinylbenzene.Other suitable vinyl terminated multifunctional auxiliary agents include, but are not limited to, trivinylcyclohexane and diethylene glycol divinyl ether.

[0024] The molecular structure of the vinyl terminated multifunctional auxiliary agent can be represented by formula (I), wherein n>=2:

[0025]

[0026] In one embodiment, the molecular structure of the vinyl terminated multifunctional auxiliary agent can be represented by formula (I), wherein n>=3.

[0027] In one embodiment, the vinyl terminated multifunctional auxiliary agent includes an acrylate terminated multifunctional auxiliary agent. The molecular structure of the acrylate terminated multifunctional auxiliary agent can be represented by formula (II), wherein n>=2:

[0028]

[0029] In one embodiment, the molecular structure of the acrylate-terminated multifunctional auxiliary agent can be represented by formula (II), wherein n>=3.

[0030] In some embodiments, the acrylate-terminated multifunctional auxiliary agent includes trimethylolpropane triacrylate (TMPTA SR351H, SR351HP). TMPTA is commercially available from Sartomer. Other suitable acrylate-terminated multifunctional auxiliary agents include, but are not limited to, cyclohexanedimethanol diacrylate (SR406), alkoxylated hexanediol diacrylate (SR561, SR562, SR563, SR564), alkoxylated neopentyl glycol diacrylate (SR9043), 1,3-butanediol diacrylate (SR212B), 1,4-butanediol diacrylate (SR213), diethylene glycol diacrylate (DEGDA, SR230), 1,6-hexanediol diacrylate (HDDA, SR238, SR238B, SR238BTF), neopentyl glycol diacrylate, polyethylene glycol diacrylate Ester (SR259, SR344, SR610), tetraethylene glycol diacrylate (SR268), tripropylene glycol diacrylate (TPGDA, SR306F, SR306FTF), ethoxylated bisphenol A diacrylate (SR349, SR601, SR602, SR9038, CN120A60), dipropylene glycol diacrylate (DPGDA, tricyclodecane dimethanol diacrylate (SR833S), neopentyl glycol diacrylate (SR9209A), propoxylated neopentyl glycol diacrylate (SR9003B), tris(2-hydroxyethyl) isocyanurate triacrylate (THEICTA SR368, SR368D), ethoxylated trimethylolpropane triacrylate (SR415, SR454, SR499, SR502, SR9035), pentaerythritol triacrylate (PETIA SR444), propoxylated trimethylolpropane triacrylate (SR492, SR501), propoxylated glycerol triacrylate (GPTA, SR9020), pentaerythritol tetraacrylate (SR295), di-trimethylolpropane tetraacrylate (SR355), dipentaerythritol pentaacrylate (DiPEPA, SR399, SR399LV), ethoxylated pentaerythritol tetraacrylate (SR494), alkoxylated pentaerythritol tetraacrylate (LM5401), low viscosity diacrylate oligomer (CN132), low viscosity triacrylate oligomer (CN133US), etc., which are commercially available from Sartomer.

[0031] In some embodiments, the reactive mixture comprises a combination of two or more adjuvants.

[0032] peroxide

[0033] Suitable peroxides include, but are not limited to, the following: LUPEROX 101 (2,5-dimethyl-2,5-di(tert-butylperoxy)hexane) CAS No. 78-63-7; LUPEROX DC (diisopropylbenzene peroxide), CAS No. 80-43-3; LUPEROX DTA (di(tert-amyl)peroxide) CAS No. 10508-09-5; LUPEROX P (tert-butylperoxybenzoate) CAS No. 614-45-9; LUPEROX TAP (tert-amyl peroxybenzoate) CAS No. 4511-39-1; LUPEROX F (a,a'-bis(tert-butylperoxy)-diisopropylbenzene) CAS No. 25155-25-3; and LUPEROX TBEC (OO-tert-butyl O-(2-ethylhexyl)monoperoxycarbonate) CAS No. 34443-12-4. LUPEROX 101 is a preferred peroxide. The purpose of the peroxide is to act as a free radical initiator by generating free radical species for free radical reactions, particularly grafting reactions. The peroxide can decompose into at least one primary free radical selected from the following free radicals: (a) RCOO·, wherein R is an alkyl group; (b) RO·, wherein R is an alkyl group; or c) ROC(O)O·, wherein R is an alkyl group.

[0034] In some embodiments, the reactive mixture comprises a combination of two or more peroxides.

[0035] Extruder

[0036] The example that can be used for extruding reactive mixture to form the extruder of epoxy-functionalized ethylene polymer includes but is not limited to co-rotating intermeshing twin screw extruder, counter-rotating twin screw extruder, tangential twin screw extruder, Buss kneader extruder, planetary extruder and single screw extruder.In addition, the feature of interest is the design specification including length / diameter ratio (L / D ratio) and mixing section (screw design).Usually, for a single extruder, the maximum L / D ratio is about 60.For longer L / D ratio, two extruders are coupled.Screw design includes but is not limited to those including mixing elements (such as kneading disk block, left-handed screw element, turbine mixing element, gear mixing element and the combination formed by them).

[0037] Although it has been found that grafting in a twin screw extruder with an appropriate residence time (30 seconds to 3 minutes) to complete the reaction gives the best results, other extruders can be used, including but not limited to those described above. Longer residence times are possible, but limit the rate and production capacity of the grafting extruder. In addition, it is important to use a peroxide with an appropriate half-life at the melt temperature to achieve the residence time in the extruder. Suitable peroxides are discussed above.

[0038] Both modern modular extruders and single barrel extruders are characterized by temperature control capabilities across various segments. Thus, different barrel temperatures can be set and controlled along the length of the barrel. The maximum barrel temperature is the maximum set temperature. Different barrel temperatures are needed to control energy input and melt temperature along the length of the extruder and to control the extrudate temperature.

[0039] Extruder barrels house the screw or rotor of the extruder. They are used to contain the polymer in the extruder and are designed to provide heating or cooling to the polymer being processed through heaters and cooling channels. They are designed to withstand the high temperatures and pressures encountered during extrusion operations.

[0040] The screw / rotor can rotate at varying speeds (typically up to 1500 rpm). The rotation of the screw / rotor also inputs energy into the material being processed in the extruder, raising its temperature and thereby facilitating melting, mixing and reaction.

[0041] Processing results

[0042] In one embodiment, the process for making the epoxy-functionalized ethylene polymer results in a grafting level of at least 0.4 wt%, at least 2 wt%, at least 3%, or at least 4%.

[0043] In one embodiment, the process for making the epoxy-functionalized ethylene polymer produces a grafting efficiency greater than or equal to 30%, greater than or equal to 40%, or greater than or equal to 50%.

[0044] In one or more embodiments, when glycidyl methacrylate (GMA) is used as the epoxy functional monomer and trimethylolpropane triacrylate (TMPTA) is used as the coagent, a grafting level of at least 5% and a grafting efficiency of at least 65% are achieved without significant crosslinking.

[0045] Epoxy-functionalized vinyl polymers

[0046] Also provided is an epoxy-functionalized ethylene polymer formed from an embodiment or combination of embodiments described herein.

[0047] In one embodiment, the epoxy-functionalized ethylene polymer has a melt viscosity of less than or equal to 50,000 cP, less than or equal to 40,000 cP, less than or equal to 30,000 cP, less than or equal to 20,000 cP, or less than or equal to 15,000 cP at 350°F (177°C). In one embodiment, the epoxy-functionalized ethylene polymer has a melt viscosity of 6,500 cP to 50,000 cP, 6,500 cP to 30,000 cP, or 10,000 cP to 30,000 cP at 350°F (177°C). It is important that the epoxy-functionalized ethylene polymer has a melt viscosity of less than or equal to 50,000 cP at 350°F (177°C) because this demonstrates that unacceptable levels of crosslinking have been avoided. Excessive crosslinking can hinder grafting efficiency. Furthermore, as mentioned above, it is important that the epoxy-functionalized vinyl polymer have a low viscosity in order to achieve good compatibilization in packaging recycling.

[0048] Also provided is a compatibilized formulation comprising an epoxy-functionalized ethylene polymer formed from an embodiment or combination of embodiments described herein.

[0049] In some embodiments, the compatibilized formulation may include between 1 wt% and 10 wt% epoxy-functionalized vinyl polymer, between 2 wt% and 10 wt% epoxy-functionalized vinyl polymer, between 4 wt% and 10 wt% epoxy-functionalized vinyl polymer, between 5 wt% and 8 wt% epoxy-functionalized vinyl polymer, between 5 wt% and 7 wt% epoxy-functionalized vinyl polymer. In one embodiment, the compatibilized formulation includes 6 wt% epoxy-functionalized vinyl polymer.

[0050] Compatibilized formulations incorporating epoxy-functionalized ethylene polymers produced according to the present disclosure may comprise an Izod impact strength (at ambient temperature) of greater than, or equal to, 200 J / m, greater than, or equal to, 250 J / m, greater than, or equal to, 300 J / m, or greater than, or equal to, 335 J / m, when measured via ASTM D256 Method A (as described in the Test Methods section of the present disclosure).

[0051] Compatibilized formulations incorporating epoxy-functionalized ethylene polymers produced according to the present disclosure may comprise an elongation at break of greater than, or equal to, 50%, greater than, or equal to, 60%, greater than, or equal to, 70%, or greater than, or equal to, 75%, when measured via ASTM D4703 (Procedure C) according to Appendix A.1 (as described in the Test Methods section of the present disclosure).

[0052] Compatibilized formulations incorporating epoxy-functionalized ethylene polymers produced according to the present disclosure may comprise a stress at break of greater than, or equal to, 1000 psi, greater than, or equal to, 1100 psi, greater than, or equal to, 1200 psi, or greater than, or equal to, 1300 psi, when measured via ASTM D4703 (Procedure C) according to Appendix A.1 (as described in the Test Methods section of the present disclosure).

[0053] Compatibilized formulations incorporating epoxy-functionalized ethylene polymers produced according to the present disclosure may comprise a low shear viscosity greater than, or equal to, 10,000 Pa·s, greater than, or equal to, 10,500 Pa·s, greater than, or equal to, 11,500 Pa·s, or greater than, or equal to, 12,500 Pa·s at 275° C. and a frequency of 0.1 rad / s, when measured according to the dynamic mechanical spectroscopy (DMS) method (as described in the Test Methods section of the present disclosure).

[0054] definition

[0055] As used herein, the term "composition" includes the materials or mixtures of materials that constitute the composition, as well as reaction products and decomposition products formed from the materials of the composition. Typically, any reaction products and / or decomposition products are present in trace amounts.

[0056] The term "polymer" refers to a polymeric compound prepared by polymerizing monomers of the same or different types. Thus, the generic term polymer encompasses the term "homopolymer," which generally refers 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 the polymerization of at least two different types of monomers. Thus, the generic term interpolymer includes copolymers or polymers prepared from more than two different types of monomers, such as terpolymers.

[0057] "Polyethylene" or "ethylene-based polymer" shall mean a polymer comprising greater than or equal to 50 mole % of units derived from ethylene monomers. This includes ethylene-based homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of ethylene-based polymers known in the art include, but are not limited to: low density polyethylene (LDPE); linear low density polyethylene (LLDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); single-site catalyzed linear low density polyethylene, including both linear low density resins and substantially linear low density resins (m-LLDPE); medium density polyethylene (MDPE); and high density polyethylene (HDPE).

[0058] The term "LLDPE" includes resins made using a Ziegler-Natta catalyst system and resins made using single-site catalysts, including but not limited to dimetallocene catalysts (sometimes referred to as "m-LLDPE"), phosphinimines, and constrained geometry catalysts; and resins made using post-metallocene molecular catalysts, including but not limited to bis(biphenylphenoxy) catalysts (also known as polyvalent aryloxyether catalysts). LLDPE includes linear, substantially linear or heterogeneous ethylene-based copolymers or homopolymers. LLDPE contains less long chain branching than LDPE, and includes: substantially linear ethylene polymers, which are further defined in U.S. Pat. No. 5,272,236, U.S. Pat. No. 5,278,272, U.S. Pat. No. 5,582,923, and U.S. Pat. No. 5,733,155; homogeneously branched linear ethylene polymer compositions, such as the homogeneously branched linear ethylene polymer compositions in U.S. Pat. No. 3,645,992; heterogeneously branched ethylene polymers, such as heterogeneously branched ethylene polymers prepared according to the process disclosed in U.S. Pat. No. 4,076,698; and blends thereof (such as the blends disclosed in U.S. Pat. No. 3,914,342 and U.S. Pat. No. 5,854,045). LLDPE resins can be prepared via gas phase, solution phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0059] The term "HDPE" refers to ethylene-based polymers having a density greater than about 0.940 g / cc, which are typically prepared using Ziegler-Natta catalysts, chromium catalysts, or even metallocene catalysts.

[0060] "Polypropylene" or "propylene-based polymer" shall mean a polymer comprising greater than or equal to 50 mole % of units derived from propylene monomer. This includes propylene-based homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of ethylene-based polymers known in the art include, but are not limited to, impact polypropylene copolymers (icPP), random copolymers (rcPP), polypropylene homopolymers (hPP), propylene / ethylene copolymers (POE plastomers), and polypropylene reactor blends.

[0061] As used herein, term " olefin-based polymer " refers to comprise in polymeric form 50 % by weight or major amount of olefin monomers such as ethylene or propylene by the weight of polymer, and optionally may comprise a polymer of one or more comonomers. In one embodiment, olefin polymer comprises major amount of olefin monomers (by the weight of polymer), and optionally may comprise one or more comonomers. Olefin polymer is also referred to as " polyolefin " in this article.

[0062] As used herein, the term "ethylene / α-olefin interpolymer" refers to an interpolymer that comprises, in polymerized form, at least 50 weight percent or a majority amount of ethylene monomer (based on the weight of the interpolymer) and at least one α-olefin. In one embodiment, the ethylene / α-olefin interpolymer comprises a majority amount of ethylene monomer (based on the weight of the ethylene interpolymer) and at least one α-olefin.

[0063] As used herein, the term "ethylene / α-olefin copolymer" refers to a copolymer that includes, in polymerized form, at least 50 weight percent or a major amount of ethylene monomer (based on the weight of the copolymer) and an α-olefin as the only two monomer types. In one embodiment, the ethylene / α-olefin copolymer comprises a major amount of ethylene monomer (based on the weight of the ethylene-based copolymer) and an α-olefin as the only monomer types.

[0064] The term "multifunctional" when used as a descriptor for an adjuvant in conjunction with a functional group indicates that the adjuvant is terminated at least two positions by the corresponding functional group. For example, the phrase "vinyl terminated multifunctional adjuvant" refers to an adjuvant comprising a molecule terminated at at least two positions by a vinyl functional group. Similarly, the phrase "acrylate terminated multifunctional adjuvant" refers to an adjuvant comprising a molecule terminated at at least two positions by an acrylate functional group. In addition, because the acrylate functional group contains a vinyl functional group, the acrylate terminated multifunctional adjuvant represents a form of the vinyl terminated multifunctional adjuvant.

[0065] The terms "comprising," "including," "having," and derivatives thereof are not intended to exclude the presence of any additional components, steps, or procedures, whether or not specifically disclosed. For the avoidance of any doubt, all compositions claimed through use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of excludes any other components, steps, or procedures (except those that are not essential to operability) from the scope of any subsequent recitation. The term "consisting of excludes any component, step, or procedure not specifically recited or listed.

[0066] For the purposes of describing and defining the present invention, it is noted that reference to "at least one" component, element, etc. herein should not be used to create an inference that alternative use of the article "a" or "an" is limited to a single component, element, etc. For example, reference to "a" component includes aspects having two or more such components unless the context clearly dictates otherwise.

[0067] It should be noted that the terms "preferably," "usually," and "typically" as used herein are not used to limit the scope of the claimed invention or to imply that certain features are critical, necessary, or even essential to the structure or function of the claimed invention. Rather, these terms are merely intended to identify specific aspects of the embodiments of the present disclosure or to emphasize alternative or additional features that may or may not be utilized in a particular embodiment of the present disclosure.

[0068] It should be noted that one or more of the appended claims utilize the term "wherein" as a transitional expression. For purposes of defining the present invention, it should be noted that this term is introduced in the claims as an open transitional phrase that is used to introduce a recitation of a series of features of a structure and should be interpreted in the same manner as the more commonly used open introductory term "comprising."

[0069] Unless expressly stated otherwise, it is not intended that any method set forth herein be construed as requiring that its steps be performed in a particular order, nor requiring any particular orientation of the apparatus. Thus, in the absence of a method claim actually stating an order in which its steps are to be followed, or any apparatus claim actually stating an order or orientation of individual components, or in the absence of otherwise specific statements in the claims or specification that the steps are to be limited to a particular order, or in the absence of stating a particular order or orientation of components of the apparatus, no order or orientation is intended to be inferred in any respect. This applies to any possible non-expressive basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; ordinary meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

[0070] Test Method

[0071] The test methods used herein include the following:

[0072] Epoxide content - Fourier transform infrared spectroscopy (FTIR) analysis

[0073] The concentration of epoxide groups was determined by the ratio of the peak height of the epoxide groups (at the corresponding wavenumber) to the polymer reference peak, which in the case of polyethylene was at wavenumber 2751 cm -1 The epoxide content is calculated by multiplying this ratio by the appropriate calibration constant. The formula used for GMA grafted polyolefins has the following form, as shown in Equation 1, where GMA is represented by the carbonyl group at about 847 cm -1 denoted by the peak at (and with a reference peak for polyethylene).

[0074] GMA (wt%) = A*{[at 847 cm -1FTIR peak height at (Formula 1)

[0075] degrees] / [at 2751cm -1 FTIR peak height at]–B

[0076] The calibration constants A (12.403) and B (0.168) can be determined using known calibration standards. The actual calibration constants may vary slightly depending on the instrument and polymer.

[0077] The sample preparation process begins with pressing (thickness is typically 0.05 mm to 0.15 mm) between two protective films in a heated press for 3 min to 5 min at 150 ° C to 180 ° C. MYLAR and TEFLON are suitable protective films to protect the sample from the impact of the platen. The platen should withstand pressure (about 10 tons) for about five minutes. The sample is cooled to room temperature and then vacuum stripped to remove any unreacted residual GMA. After stripping, the sample is placed in an appropriate sample holder and then scanned in the FTIR. Background scans should be run before each sample scan or as needed. The accuracy of the test is good, with an inherent variability of less than ± 5%.

[0078] Grafting efficiency

[0079] The grafting efficiency was determined by normalizing the weight % of GMA determined by FTIR to the weight % fed into the formulation.

[0080] Melt viscosity

[0081] Use Brookfield digital viscometer (model DV-III, version 3) and disposable aluminum sample chamber according to ASTM D 3236 (177 ℃, 350 ℉) to measure melt viscosity. Generally speaking, the mandrel used is SC-31 hot melt mandrel, which is suitable for measuring viscosity in the range of 10 centipoise to 100,000 centipoise. Pour the sample into the chamber, then insert the chamber into the Brookfield Thermosel and lock it in place. The sample chamber has a notch at the bottom that fits the bottom of the Brookfield heater to ensure that the chamber will not rotate when the mandrel is inserted and rotated. Heat the sample (approximately 8 grams to 10 grams of resin) to the desired temperature until the molten sample is about one inch below the top of the sample chamber. Lower the viscometer device and immerse the rotor into the sample chamber. Continue to lower until the bracket on the viscometer is aligned on the heater. The viscometer was turned on and set to operate at a shear rate that resulted in a torque reading in the range of 40 to 60 percent of the total torque capacity based on the rpm output of the viscometer. Readings were collected every minute for approximately 15 minutes or until the values ​​stabilized, at which time the final reading was recorded.

[0082] Low shear viscosity

[0083] To prepare, each test sample was initially placed in a 1.5 inch diameter slot with a thickness of 3.10 mm and compression molded using a Carver hydraulic press (Model #4095.4NE2003) at 190°C with a pressure of 25,000 lbs for 6.5 min. After cooling to room temperature, the samples were removed to await rheological testing.

[0084] DMS (dynamic mechanical spectroscopy) frequency sweeps were performed using 25 mm parallel plates at frequencies ranging from 0.1 rad / s to 100 rad / s. The test gap of the separation plate was 1.8 mm, and a 10% strain was applied to satisfy the linear viscoelastic condition. Each test was performed at 275 ° C under a nitrogen atmosphere and isothermal conditions. In order to start the DMS test, the rheometer oven was first equilibrated at the desired test temperature for at least 30 min, and then the sample was loaded into the test geometry. The sample was then equilibrated in the oven with the door closed for 1 min. The test gap was then set to 1.8 mm, and the sample was distributed for 5 min to release the normal force generated. Afterwards, the oven was quickly opened, and the sample was trimmed so that there was no bulge. The DMS measurement was then started after the oven was closed again. During the test, the shear elastic modulus (G'), viscous modulus (G") and complex viscosity (η*) were measured. The complex viscosity measured at a frequency of 0.1 rad / s is referred to as low shear viscosity in this article.

[0085] All DMS frequency tests were performed on ARES-G2 or DHR-3 rheometers, both manufactured by TA Instruments. Data analysis was performed using TA Instruments’ TRIOS software.

[0086] Tensile properties

[0087] The samples were compression molded at 275°C to a nominal thickness of 0.125 inches according to ASTM D4703 (Procedure C) per Appendix A.1. Type I samples were die cut from sheets and conditioned at 23 (±2)°C and 50 (±10)% relative humidity for at least 40 hours.

[0088] Type I specimens were tested under load according to D638 (Standard Test Method for Tensile Properties of Plastics). Test speed was 2 inches / min. Crosshead displacement. Strain was measured using an extensometer attached to the specimen with an initial gauge length of 2 inches. Tensile testing was performed at 23+ / -2°C.

[0089] Impact resistance

[0090] Notched Izod impact strength testing was performed according to ASTM D256 Method A. Specimens were made to a nominal thickness of 0.125 inches from compression molded sheets prepared according to ASTM D4703 (Procedure C) as per Appendix A.1.

[0091] The specimens were cut from the sheet using an appropriate die to obtain samples with a length of 2.5 inches and a width of 0.5 inches. The samples were notched on the long side in the thickness direction using an automated notcher to leave a ligament width of 0.4 inches. The notch half angle was 22.5° and the radius of curvature at the top was 0.01 inches. The samples were conditioned at 23+ / -2°C and 50+ / -10% relative humidity for at least 40 hours. Impact testing was performed at 23+ / -2°C.

[0092] The specimens were loaded into a cantilever beam tester according to ASTM D256 Method A, with the notch facing the impactor. The pendulum was released and the energy absorbed during the test was automatically recorded. The specimens were inspected after the test and the type of failure (complete, hinged, partial or unbroken) was recorded. Each sample was tested five times.

[0093] Example

[0094] The following examples illustrate features of the present disclosure but are not intended to limit the scope of the present disclosure.The following experiments analyze the performance of embodiments of the low viscosity functionalized ethylene copolymers described herein.

[0095] The materials used in this study are shown in Table 1.

[0096] Table 1: Reagents

[0097]

[0098] * Density of 0.87 g / cc and melt viscosity of 6700 cP (177°C (350°F))

[0099] Equipment and experimental conditions

[0100] In order to produce the following examples and comparative examples, each grafting reaction was performed on a 26mm co-rotating twin screw extruder (ZSK-26 from Coperion Corp.). The extruder was configured with 15 barrels (60L / D). The maximum screw speed was 1200rpm, and the maximum motor output was 40HP. The extruder was equipped with a "loss-in-weight feeder". GMA and GMA-adjuvant mixtures were injected at barrel 3, and the peroxide impregnated on the ethylene copolymer pellets was fed through the main feed orifice. 5 standard cubic feet / hour (SCFH) of nitrogen was used to purge the first barrel segment to maintain an inert atmosphere and minimize oxidation. A vacuum (about 15" Hg) was pulled on barrel 13. A two-hole die was used to produce strands, which were cut into pellets using a strand cutter. The run rate was 8 lbs / hr and a screw speed of 375 rpm was used. Barrel 1 was water cooled; barrels 2 to 4 were maintained at 50°C to 70°C; barrels 6 to 11 were maintained at 220°C; and barrels 12 to 15 were maintained at 160°C.

[0101] The compositions of the Examples and Comparative Examples are shown in Table 2 together with the grafting level (GMA weight %), grafting efficiency (%) and viscosity (each of which was determined according to the above-mentioned test methods).

[0102] Table 2: GMA grafting examples and comparative examples; composition and results

[0103]

[0104] Table 2 – continued

[0105]

[0106] Table 2 – continued

[0107]

[0108] *1cP=0.001Pa·s

[0109] The results shown in Table 2 demonstrate low grafting levels and efficiencies when no auxiliary agent is used during the grafting process. In other words, when an auxiliary agent is used, the grafting reaction of the epoxide group (GMA in this case) onto the low viscosity polyolefin can be enhanced. The results in Table 2 also indicate the effects of various auxiliary agents. In particular, when the results for the embodiments are compared with the comparative examples, it becomes clear that the grafting efficiency is at least 30% using a multifunctional vinyl or multifunctional acrylate auxiliary agent. However, when no auxiliary agent is used or an auxiliary agent terminated with a multifunctional methacrylate is used, the grafting efficiency is always less than 20%. In addition, using a preferred auxiliary agent, the epoxy-functionalized ethylene polymer shows a minimal viscosity increase, indicating a lack of crosslinking. It is expected that Examples 2 and 11 have relatively high viscosities because both embodiments have high levels of peroxide and auxiliary agents and produce high grafting levels.

[0110] Evaluation in PE-PET compatibilized formulations

[0111] The materials used to create the experimental compatibilized formulations are shown in Table 3 below.

[0112] To produce the formulation, the RS5000 batch mixer from Rheometers Services Inc. was used to mix the samples. A bowl with a roller blade rotor was used, which could mix up to 250 g of batches. After the initial melting of the base polymers (polyethylene and polyethylene terephthalate) for a few minutes, the compatibilizer (GMA grafted polymer) was loaded into the mixer at a low speed. After all other ingredients were incorporated, the batch was mixed using a rotor speed of 30 rpm to 60 rpm and a bowl temperature of 275 ° C. Mixing was continued for another 10 to 15 minutes. After mixing, each batch was collected on a glass-reinforced Teflon sheet, pressed into a flat "cake" on a compression molding machine and cooled to ambient temperature. Compression molded samples for mechanical testing were prepared from each flat "cake" using the process described above in the test method section. Results from DMS measurements, Izod impact strength and tensile tests are also shown in Table 3.

[0113] Table 3: Compatibilization effect using GMA grafted polymers*

[0114]

[0115] *The table value is weight percentage (wt%) based on the total weight of the formulation

[0116] Measured using the DMS method described in the Test Methods section at 275°C at 0.1 rad / s (units reported in Pa·s)

[0117] DOWLEX TM2045G is a linear low density polyethylene (LLDPE) available from Dow Inc.

[0118] LDPE 501I is a low density polyethylene (LDPE) available from Dow Inc.

[0119] ELVALOY TM PTW is a GMA based ethylene terpolymer available from Dow Inc.

[0120] PET is polyethylene terephthalate

[0121] As can be seen from the results in Table 3, when the GMA grafted ethylene polymers from inventive Examples 3, 4 and 5 were incorporated into the compatibilized formulations (RC 2, RC 3 and RC 4), the resulting impact strength and ductility (elongation at break) were improved. Formulations without the GMA grafted ethylene polymer showed significantly lower impact strength and elongation at break. When compared to a commercial compatibilizer (EVALOY PTW; RC 5), the grafts of the present invention in formulations RC 2, RC 3 and RC 4 showed better flow properties (indicated by lower viscosity).

[0122] Obviously, modifications and variations are possible without departing from the scope of the present disclosure as defined in the appended claims.More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

1. A method for producing an epoxy-functionalized ethylene polymer, the method comprising: extruding a reactive mixture to form the epoxy-functional ethylene polymer, wherein the reactive mixture comprises: An ethylene polymer having a viscosity of less than or equal to 50,000 cP at 177°C; Epoxy functional monomers; Peroxides; and A vinyl terminated multifunctional auxiliary agent having a functionality of 2 or greater.

2. The method of claim 1, wherein the epoxy-functionalized ethylene polymer has a grafting efficiency greater than or equal to 30%.

3. The method of any preceding claim, wherein the epoxy-functional monomer comprises one or more of glycidyl acrylate, glycidyl methacrylate (GMA) and allyl glycidyl ether (AGE).

4. A method according to any preceding claim, wherein the reactive mixture comprises 0.3 wt% to 10.0 wt% of the epoxy functional monomer and 80 wt% to 97 wt% of the vinyl polymer.

5. The method of any preceding claim, wherein the reactive mixture comprises 0.1 wt% to 5.0 wt% of a vinyl terminated multifunctional auxiliary agent.

6. The method of any preceding claim, wherein the vinyl terminated multifunctional coagent comprises divinylbenzene.

7. The method according to any one of claims 1 to 5, wherein the vinyl terminated multifunctional auxiliary agent comprises an acrylate terminated multifunctional auxiliary agent.

8. The method of claim 7, wherein the acrylate-terminated multifunctional coagent comprises trimethylolpropane triacrylate (TMPTA).

9. The method of claim 7, wherein the acrylate-terminated multifunctional auxiliary agent comprises an alkylene glycol diacrylate or a polyalkylene glycol diacrylate.

10. The method of any preceding claim, wherein the ethylene polymer has a viscosity of 5,000 cP to 50,000 cP (at 177°C).

11. The method of any preceding claim, wherein the epoxy-functionalized ethylene polymer has a viscosity (at 177°C) of 6,500 cP to 50,000 cP, or 6,500 cP to 30,000 cP.

12. The method of any preceding claim, wherein the ethylene-based polymer comprises an ethylene / α-olefin copolymer having a density of 0.850 g / cc to 0.900 g / cc.

13. A method according to any preceding claim, wherein extruding the reactive mixture is performed using a twin screw extruder.

14. An epoxy functionalized vinyl polymer produced by a process according to any preceding claim.

15. A compatibilizer formulation comprising the epoxy-functionalized ethylene polymer according to claim 14.

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