Heterophasic conductive polymer composite composition

Abstract

A composition comprising a ternary phase polymer composite, the ternary phase polymer composite comprising component (A) having a γ of ≤5 mN / m to ≥1 mN / m P Ethylene / unsaturated ester copolymer; at least two other polymers selected from the group consisting of: (B) having ≥ 0mN / m to <1mN / m γ P a non-polar polymer selected from the group consisting of polyethylene homopolymers, silane-functionalized polyethylene homopolymers, ethylene / α-olefin copolymers, and silane-functionalized ethylene / α-olefin copolymers; (C) having a γ of >5 mN / m P (A) and only one of the at least two other polymers, wherein (i) one of the at least two other polymers is selected from (B) and the other is selected from (C) or (D), or (ii) one of the at least two other polymers is selected from (C) and the other is selected from (B) or (D).

Description

BACKGROUND

[0001] Generally, single polymer systems require large concentrations of conductive filler to achieve significant electrical conductivity, e.g., about 10 -9 to 10 -3 S / cm. Such large concentrations of conductive filler increase the melt viscosity of the material while also decreasing the mechanical properties of the material. At reduced filler concentrations, one method of increasing the composite conductivity and thereby minimizing the adverse effects on mechanical and rheological properties is to use a multiphase polymer blend that can reduce the percolation threshold. In the case of two-component polymer blends, several studies have found that the percolation threshold can be reduced using a two-phase polymer blend in which the conductive filler has been incorporated into the immiscible polymer blend and the percolation threshold is controlled by the percolation of the phase rich in conductive filler and the continuity of this phase in the polymer blend.

[0002] The use of ternary polymer blends (i.e., three-component polymer blends) in combination with conductive fillers (e.g., carbon black) has also been shown to reduce the percolation threshold and achieve electrical conductivity in several different polymer systems. However, such ternary polymer blends still exhibit significant brittleness. Depending on the application, it can be desirable to improve the brittleness at the expense of increasing the percolation threshold.

[0003] There is a need for a polymer composite composition that uses cross-linkable polymers and exhibits improved, i.e., lower, percolation thresholds and improved, i.e., lower, brittleness. Furthermore, there is a need for such a composite composition that exhibits improved, i.e., lower, melting points and glass transition temperatures and improved, i.e., increased, flexibility, especially for cable applications. SUMMARY

[0004] The present disclosure provides a composition comprising: a ternary phase polymer composite comprising:

[0005] (A) at least one copolymer of ethylene and an unsaturated ester having a polar component with a surface tension (γ P ) less than or equal to 5 millinewtons per meter (mN / m) to greater than or equal to 1 mN / m;

[0006] at least two other polymers selected from the group consisting of:

[0007] (B) at least one non-polar polymer having a polar component with a surface tension (γ P ) greater than or equal to 0 mN / m to less than 1 mN / m and selected from the group consisting of polyethylene homopolymers, silane functionalized polyethylene homopolymers, ethylene / alpha-olefin copolymers, and silane functionalized ethylene / alpha-olefin copolymers;

[0008] (C) at least one copolymer of ethylene and an unsaturated ester having a polar component with a surface tension (γP ) a polar component having a surface tension (γ

[0009] (D) at least one ethylene propylene diene monomer copolymer; and

[0010] a conductive filler dispersed in only one of component (A) and at least two other polymers,

[0011] wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D).

[0012] In another embodiment, the present disclosure provides a cable comprising a conductor, a semiconductive inner layer covering at least a portion of the conductor; an insulating layer covering at least a portion of the semiconductive inner layer; and a semiconductive outer layer covering at least a portion of the insulating layer, wherein at least one of the semiconductive inner layer and the outer semiconductive layer comprises a ternary phase polymer composite comprising

[0013] (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a surface tension (γ P ) a polar component having a surface tension (γ

[0014] at least two other polymers selected from the group consisting of:

[0015] (B) at least one non-polar polymer having a surface tension (γ P ) a polar component having a surface tension (γ

[0016] (C) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a surface tension (γ P ) a polar component having a surface tension (γ

[0017] (D) at least one ethylene propylene diene monomer copolymer; and

[0018] a conductive filler dispersed in only one of component (A) and at least two other polymers,

[0019] wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D). BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a graph comparing the resistivity date of comparative examples to inventive examples, which shows a percolation threshold. DETAILED DESCRIPTION

[0021] In one embodiment, the present disclosure provides a composition comprising a ternary phase polymer composite comprising components: (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of less than or equal to 5 millinewtons per meter (mN / m) to greater than or equal to 1 mN / m; at least two other polymers selected from the group consisting of: (B) at least one non-polar polymer having a polar component with a surface tension (γ P ) of greater than or equal to 0 mN / m to less than 1 mN / m, and which is selected from the group consisting of: a polyethylene homopolymer, a silane-functionalized polyethylene homopolymer, an ethylene / alpha-olefin copolymer, and a silane-functionalized ethylene / alpha-olefin copolymer; (C) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of greater than 5 mN / m; and (D) at least one ethylene propylene diene monomer copolymer; and a conductive filler dispersed in only one of components (A) and the at least two other polymers, wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D).

[0022] Component A

[0023] In one embodiment, the ternary polymer composite comprises (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of less than or equal to 5 mN / m to greater than or equal to 1 mN / m (“component (A)’).

[0024] In one embodiment, the unsaturated ester is an alkyl acrylate or an alkyl methacrylate. Preferably, the alkyl group is a C1-C8 alkyl group, and more preferably a C1-C4 alkyl group. Preferred carboxylic acid esters are carboxylic acid esters containing 2 to 8 carbon atoms, and more preferably 2 to 5 carbon atoms.

[0025] Exemplary acrylates and methacrylates are dodecyl methacrylate; tetradecyl methacrylate; hexadecyl methacrylate; octadecyl methacrylate; 3-methacryloyloxy- propyltrimethoxysilane; 3-methacryloyloxypropyltriethoxysilane; cyclohexyl methacrylate; n- hexyl methacrylate; isodecyl methacrylate; 2-methoxyethyl methacrylate; tetrahydrofurfuryl methacrylate; octyl methacrylate; 2-phenoxyethyl methacrylate; isochromanoyl methacrylate; isooctyl methacrylate; isooctyl methacrylate; oleyl methacrylate; ethyl acrylate; methyl acrylate; t-butyl acrylate; n-butyl acrylate; and 2-ethylhexyl acrylate. Preferred are methyl acrylate, ethyl acrylate, and n-butyl acrylate or t-butyl acrylate.

[0026] In an embodiment, the amount of ester comonomer in component (A) is greater than or equal to 2 wt%, or greater than or equal to 10 wt%, or greater than or equal to 15 wt% to less than or equal to 55 wt%, or to less than or equal to 30 wt%.

[0027] In an embodiment, the density of component (A) is greater than or equal to 0.900 g / cc, or greater than or equal to 0.920 g / cc to less than or equal to 0.990 g / cc, or to less than or equal to 0.970 g / cc.

[0028] In an embodiment, the melt index of component (A) is greater than or equal to 0.1 g / 10 min, or greater than or equal to 1 g / 10 min, or greater than or equal to 5 g / 10 min to less than or equal to 100 g / 10 min, or to less than or equal to 50 g / 10 min, or to less than or equal to 21 g / 10 min.

[0029] In an embodiment, the melting point of component (A) is less than 166 °C.

[0030] In an embodiment, the glass transition temperature (Tg) of component (A) is less than 25 °C.

[0031] Preferably, component (A) is selected from the group consisting of ethylene-ethyl acrylate, ethylene-methyl acrylate, ethylene-butyl acrylate, and combinations thereof.

[0032] In an embodiment, component (A) can be a mixture of two or more copolymers of ethylene and an unsaturated ester, the mixture having a surface tension (γ P ) of less than or equal to 5 mN / m to greater than or equal to 1 mN / m of a polar component.

[0033] In an embodiment, component (A) is present in the terpolymer composite in an amount greater than 0 vol%, or greater than or equal to 1 vol%, or greater than or equal to 2.5 vol%, or greater than or equal to 7.5 vol%, or greater than or equal to 15 vol% to less than or equal to 40 vol%, or to less than or equal to 30 vol%, or to less than or equal to 25 vol%, based on the total volume of the composite.

[0034] Component B

[0035] In an embodiment, the terpolymer composite includes (B) at least one non-polar polymer having a surface tension (γ P ) greater than or equal to 0 mN / m to less than 1 mN / m, and which is selected from the group consisting of polyethylene homopolymers, silane-functionalized polyethylene homopolymers, ethylene / alpha-olefin copolymers, and silane-functionalized ethylene / alpha-olefin copolymers (“component (B)”).

[0036] In an embodiment, component (B) is a polyethylene homopolymer. Preferably, the polyethylene homopolymer is a low density polyethylene (LDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), or high density polyethylene (HDPE).

[0037] LDPE is known in the art and is commercially available. Typically, the LDPE has a density greater than or equal to 0.910 g / cc to less than or equal to 0.940 g / cc.

[0038] VLDPE is known in the art and is commercially available. Typically, the VLDPE has a density greater than or equal to 0.860 g / cc to less than or equal to 0.915 g / cc.

[0039] LLDPE is known in the art and is commercially available. Typically, the LLDPE has a density greater than or equal to 0.916 g / cc to less than or equal to 0.925 g / cc.

[0040] MDPE is known in the art and is commercially available. Typically, the MDPE has a density greater than or equal to 0.925 g / cc to less than or equal to 0.940 g / cc.

[0041] HDPE is known in the art and is commercially available. Typically, the density is greater than or equal to 0.940 g / cc to less than or equal to 0.970 g / cc.

[0042] In an embodiment, component (B) is an ethylene / alpha-olefin copolymer.

[0043] An alpha-olefin is a hydrocarbon molecule or substituted hydrocarbon molecule (i.e., a hydrocarbon molecule that includes one or more atoms other than hydrogen and carbon (e.g., halogen, oxygen, nitrogen, etc.)), the hydrocarbon molecule including (i) only one ethylenic unsaturation, the unsaturation being between a first carbon atom and a second carbon atom, and (ii) at least 3 carbon atoms, preferably 3 to 20 carbon atoms, in some cases preferably 4 to 10 carbon atoms and in other cases preferably 4 to 8 carbon atoms. Non-limiting examples of alpha-olefins from which copolymers are made include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-dodecene, and mixtures of two or more of these monomers.

[0044] In an embodiment, the ethylene / alpha-olefin copolymer is preferably an ethylene / propylene, ethylene / 1-butene, ethylene / 1-hexene, or ethylene / 1-octene copolymer, and more preferably an ethylene / propylene, ethylene / 1-butene, ethylene / 1-hexene, or ethylene / 1-octene diene.

[0045] In an embodiment, ethylene / alpha-olefins suitable for use in the present disclosure include greater than 50 mol% of polymerized ethylene monomer and at least one alpha-olefin comonomer, based on the total amount of polymerizable monomers.

[0046] In an embodiment, the polyethylene homopolymer or ethylene / alpha-olefin copolymer is silane functionalized. Such silane functionalized polymers can be made by copolymerization with a vinyl silane monomer or by one of a number of methods for grafting silane-containing molecules to the backbone of a polymer. Examples of such techniques are disclosed in U.S. Patent Nos. 3,646,155; 6,420,485; 6,331,597; 3,225,018; 4,574,133; or 6,048,935, all of which are incorporated herein by reference. Examples of silane compounds that can be used to add silane functionality to the polyethylene homopolymer or ethylene / alpha-olefin copolymer include, but are not limited to, vinyl silanes, such as vinyl trialkoxysilane. Generally, the amount of silane is generally greater than 0 wt% to less than or equal to 5 wt%, based on the total weight of the polyethylene homopolymer or ethylene / alpha-olefin copolymer.

[0047] In an embodiment, component (B) is a silane functionalized polyethylene homopolymer or a silane functionalized ethylene / alpha-olefin copolymer. In an embodiment, component (B) is a silane functionalized polyethylene homopolymer or a silane functionalized ethylene / alpha-olefin copolymer and is crosslinked.

[0048] In an embodiment, component (B) is a silane grafted polyethylene homopolymer or a silane grafted ethylene / alpha-olefin copolymer. In an embodiment, component (B) is a silane grafted polyethylene homopolymer or a silane grafted ethylene / alpha-olefin copolymer and is crosslinked.

[0049] Preferably, component (B) is selected from the group consisting of polyethylene homopolymers, silane-functionalized polyethylene homopolymers, and combinations thereof. More preferably, component (B) is selected from the group consisting of LDPE, silane-functionalized LDPE, and combinations thereof.

[0050] In an embodiment, component (B) has a polar component with a surface tension (γ P ) less than 1 mN / m, or less than or equal to 0.5 mN / m, or less than 0.5 mN / m, or 0.0 mN / m.

[0051] In an embodiment, component (B) has a melting point less than 166 °C.

[0052] In an embodiment, component (B) has a glass transition temperature (Tg) less than 25 °C.

[0053] In an embodiment, component (B) can be a mixture of two or more non-polar polymers with a polar component having a surface tension (γ P ) greater than or equal to 0 mN / m to less than 1 mN / m and selected from the group consisting of polyethylene homopolymers, silane-functionalized polyethylene homopolymers, ethylene / alpha-olefin copolymers, and silane-functionalized ethylene / alpha-olefin copolymers.

[0054] In an embodiment, component (B) is present in an amount of 0 vol%, or greater than 0 vol%, or greater than or equal to 30 vol%, or greater than or equal to 35 vol%, or greater than or equal to 40 vol% to less than or equal to 50 vol%, or to less than or equal to 49 vol%, or to less than or equal to 48 vol%, or to less than or equal to 45 vol%, or to less than or equal to 42 vol%, based on the total volume of the composite.

[0055] Component C

[0056] In an embodiment, the terpolymer composite includes (C) at least one copolymer of ethylene and an unsaturated ester having a polar component with a surface tension (γ P ) greater than 5 mN / m, or greater than or equal to 6 mN / m, or greater than or equal to 7 mN / m, or greater than or equal to 8 mN / m (“component (C)”).

[0057] In an embodiment, the copolymer of ethylene and an unsaturated ester suitable for use in the present disclosure includes greater than or equal to 5 wt%, or greater than or equal to 10 wt%, or greater than or equal to 15 wt%, or greater than or equal to 20 wt% to less than or equal to 50 wt%, or to less than or equal to 40 wt%, or to less than or equal to 35 wt%, or to less than or equal to 30 wt% of one or more unsaturated esters, based on the total weight of the copolymer.

[0058] In an embodiment, the unsaturated ester suitable for use in the present disclosure includes, and is not limited to, vinyl acetate, ethyl acrylate, and butyl acrylate. Preferably, the unsaturated ester is vinyl acetate.

[0059] In an embodiment, the melting point of component (C) is less than 166 °C.

[0060] In an embodiment, the glass transition temperature (Tg) is less than 25 °C.

[0061] In an embodiment, component (C) is crosslinked.

[0062] In an embodiment, component (C) can be a mixture of two or more copolymers of ethylene and an unsaturated ester, the mixture having a surface tension (γ P ) of greater than 5 mN / m, or greater than or equal to 6 mN / m, or greater than or equal to 7 mN / m, or greater than or equal to 8 mN / m of a polar component.

[0063] In an embodiment, component (C), i.e., the copolymer of ethylene and an unsaturated ester, is present in an amount of 0 vol%, or greater than 0 vol%, or greater than or equal to 30 vol%, or greater than or equal to 35 vol%, or greater than or equal to 40 vol% to less than or equal to 50 vol%, or to less than or equal to 49 vol%, or to less than or equal to 48 vol%, or to less than or equal to 45 vol%, or to less than or equal to 42 vol% based on the total volume of the composite.

[0064] Component D

[0065] In an embodiment, the terpolymer composite includes (D) at least one ethylene propylene diene monomer (EPDM) copolymer. Preferably, the at least one EPDM copolymer is an EPDM terpolymer (“component (D)”).

[0066] In an embodiment, the EPDM copolymer includes units derived from ethylene, units derived from propylene, and units derived from at least one conjugated or non-conjugated diene.

[0067] Exemplary conjugated dienes suitable for use in the EPDM copolymers of the present disclosure include, for example, butadiene, isoprene, 2,3-dimethylbutadiene-1,3, 1,2-dimethylbutadiene-1,3, 1,4-dimethylbutadiene-1,3, 1-ethylbutadiene-1,3, 2-phenylbutadiene-1,3, hexadiene-1,3, 4-methylpentadiene-1,3, 1,3-pentadiene (CH3CH=CH-CH=CH2; commonly referred to as pentadiene), 3-methyl-1,3-pentadiene, 2,4 dimethyl-1,3-pentadiene, 3-ethyl-1,3-pentadiene. Preferred conjugated dienes include butadiene and isoprene.

[0068] Exemplary non-conjugated dienes suitable for the EPDM copolymers of the present disclosure include, for example, aliphatic dienes, such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 2-methyl-1,5-hexadiene, 1,6-heptadiene, 6-methyl-1,5-heptadiene, 1,6-octadiene, 1,7-octadiene, 7-methyl-1,6-octadiene, 1,13-tetradecadiene, 1,19-eicosadiene; cyclic dienes, such as 1,4-cyclohexadiene, bicyclo[2.2.1]hepta-2,5-diene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-vinyl-2-norbornene, bicyclo[2.2.2]octa-2,5-diene, 4-vinylcyclohex-1-ene, bicyclo[2.2.2]octa-2,6-diene, 1,7,7-trimethylbicyclo[2.2.1]hepta-2,5-diene, dicyclopentadiene, methyltetrahydroindene, 5-allylbicyclo[2.2.1]hepta-2-ene, and 1,5-cyclooctadiene; aromatic dienes, such as 1,4-diallylbenzene and 4-allyl-1H-indene; and trienes, such as 2,3-diisopropenyl-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, and 1,4,9-decatriene. Preferred non-conjugated dienes include dicyclopentadiene (DCPD), ethylidene norbornene (ENB), and vinyl norbornene (VNB).

[0069] Preferably, the diene is a non-conjugated diene. Preferably, the diene is a non-conjugated diene selected from the group consisting of DCPD, ENB, and VNB.

[0070] Generally, the EPDM copolymer includes greater than or equal to 30 wt%, or greater than or equal to 40 wt%, or greater than or equal to 50 wt% to less than or equal to 80 wt%, or to less than or equal to 70 wt%, or to less than or equal to 60 wt% of units derived from ethylene, based on the total weight of the EPDM copolymer; greater than or equal to 15 wt%, or greater than or equal to 20 wt%, or greater than or equal to 25 wt% to less than or equal to 60 wt%, or to less than or equal to 55 wt%, or to less than or equal to 50 wt% of units derived from propylene; and greater than 0 wt%, or greater than or equal to 0.1 wt%, or greater than or equal to 0.5 wt% to less than or equal to 10 wt%, or to less than or equal to 5 wt%, or to less than or equal to 2 wt% of units derived from one or more dienes (e.g., conjugated or non-conjugated dienes).

[0071] In a preferred embodiment, the EPDM copolymer has a polar component with a surface tension (γ P ) greater than 5 mN / m, or greater than or equal to 5.1 mN / m, or greater than or equal to 5.2 mN / m, or greater than or equal to 5.3 mN / m.

[0072] In an embodiment, component (D) has a melting temperature less than 166 °C.

[0073] In an embodiment, component (D) has a glass transition temperature (Tg) less than 25 °C.

[0074] In an embodiment, component (D) is crosslinked.

[0075] In an embodiment, component (D) can be a mixture of two or more ethylene propylene diene monomer (EPDM) copolymers.

[0076] In an embodiment, component (D), i.e., the EPDM copolymer, is present in an amount of 0 vol%, or greater than 0 vol%, or greater than or equal to 30 vol%, or greater than or equal to 35 vol%, or greater than or equal to 40 vol% to less than or equal to 50 vol%, or to less than or equal to 49 vol%, or to less than or equal to 48 vol%, or to less than or equal to 45 vol%, or to less than or equal to 42 vol%, based on the total volume of the composite.

[0077] Conductive filler

[0078] In an embodiment, the conductive filler is dispersed in only one of the components of the triphasic polymer composite, i.e., only one of component (A), component (B), component (C), and component (D). Preferably, the conductive filler is dispersed in component (A).

[0079] In an embodiment, the conductive filler is selectively dispersed in only one of the components of the triphasic polymer composite. That is, in an embodiment, the conductive filler is purposefully and intentionally premixed with only one of the components of the triphasic polymer composite such that it is only dispersed in that one component in the final composition.

[0080] In an embodiment, the component of component (A), component (B), component (C), and component (D) that is not dispersed with the conductive filler is essentially free of the conductive filler. For example, if the conductive filler is dispersed in component (A), then the remaining two components selected from component (B), component (C), and component (D) are essentially free of the conductive filler. As used herein, "essentially free of conductive filler" means that each of the components other than the component that includes the conductive filler includes less than or equal to 0.5 vol%, or less than or equal to 0.25 vol%, or less than or equal to 0.1 vol%, or less than or equal to 0.05 vol% of the conductive filler based on the total volume of the component.

[0081] The electrically conductive filler can be conventional carbon black commonly used in semiconductive shields. Other electrically conductive fillers suitable for use in the present disclosure include carbon fullerenes (preferably carbon nanotubes), graphite, graphene, other metal particles, and electrically conductive polymers such as polyacetylene, polyparaphenylene, polypyrrole, polythiophene, and polyaniline. Preferably, the electrically conductive filler is selected from the group consisting of carbon black, carbon nanotubes, graphite, graphene, and combinations thereof. Most preferably, the electrically conductive filler is carbon black.

[0082] The average particle size of representative carbon blacks suitable for use in the present disclosure can be greater than 0 to less than or equal to 100 nanometers (nm), preferably to less than or equal to 50 nm. In one embodiment, the carbon black suitable for use in the present disclosure has a surface area (BET) of greater than or equal to 700 m 2 / g to less than or equal to 1250 m 2 / g, or greater than or equal to 700 m 2 / g to less than or equal to 900 m 2 / g. In one embodiment, the carbon black suitable for use in the present disclosure has an oil absorption (dibutyl phthalate or DBP) of greater than or equal to 200 ml / 100 g to less than or equal to 600 ml / 100 g, or greater than or equal to 300 ml / 100 g to less than or equal to 500 ml / 100 g.

[0083] In one embodiment, Akzo Ketjenblack EC300J is a suitable carbon black for use in the present disclosure having a particle size of about 35 nm or less, a surface area (BET) of about 750 to 850 m 2 / g, and an oil absorption of about 300 to 400 ml / 100 g.

[0084] In one embodiment, the electrically conductive filler is present in the terpolymer composite in an amount greater than 0 vol%, or greater than or equal to 0.25 vol%, or greater than or equal to 0.5 vol%, or greater than or equal to 1 vol%, or greater than or equal to 1.5 vol%, or greater than or equal to 2 vol%, or greater than or equal to 3 vol%, or greater than or equal to 5 vol%, or greater than or equal to 10 vol% to less than or equal to 30 vol%, or to less than or equal to 20 vol%, or to less than or equal to 15 vol%, or to less than or equal to 12 vol%, based on the total volume of the composite.

[0085] The composition

[0086] The present disclosure provides a composition comprising a terphase polymer composite comprising components: (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a surface tension (γ P) less than or equal to 5 mN / m to greater than or equal to 1 mN / m polar component; at least two other polymers selected from the group consisting of: (B) at least one polymer having a surface tension (γ P ) greater than or equal to 0.0 mN / m to less than 1 mN / m polar component of a nonpolar polymer and selected from the group consisting of: polyethylene homopolymer, silane functionalized polyethylene homopolymer, ethylene / alpha-olefin copolymer, and silane functionalized ethylene / alpha-olefin copolymer; (C) at least one copolymer of ethylene with an unsaturated ester, the copolymer having a surface tension (γ P ) greater than 5 mN / m polar component; and (D) at least one ethylene propylene diene monomer copolymer; and a conductive filler dispersed in only one of component A and at least two other polymers, wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D).

[0087] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (C); or components (A), (B), and (D); or components (A), (C), and (D). In an embodiment, the ternary phase polymer composite includes a conductive filler dispersed in component (A).

[0088] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (C), wherein the conductive filler is dispersed in component (A).

[0089] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (C), wherein the conductive filler is dispersed in component (B).

[0090] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (C), wherein the conductive filler is dispersed in component (C).

[0091] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (D), wherein the conductive filler is dispersed in component (A).

[0092] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (D), wherein the conductive filler is dispersed in component (B).

[0093] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (B), and (D), wherein the electrically conductive filler is dispersed in component (D).

[0094] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (C), and (D), wherein the electrically conductive filler is dispersed in component (A).

[0095] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (C), and (D), wherein the electrically conductive filler is dispersed in component (C).

[0096] In an embodiment, the composition includes a ternary phase polymer composite including components (A), (C), and (D), wherein the electrically conductive filler is dispersed in component (D).

[0097] In an embodiment, the composition includes components (A), (B), and (C), wherein component (B) is a polyethylene homopolymer or a silane grafted polyethylene homopolymer. In an embodiment, the composition includes components (A), (B), and (D), wherein component (B) is a polyethylene homopolymer or a silane functionalized polyethylene homopolymer.

[0098] In an embodiment, the present disclosure provides a composition including a ternary phase polymer composite including components: (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of less than or equal to 5 mN / m to greater than or equal to 1 mN / m; at least two other polymers selected from the group consisting of: (B) at least one non-polar polymer having a polar component with a surface tension (γ P ) of greater than or equal to 0.0 mN / m to less than 1 mN / m, and which is selected from the group consisting of: a polyethylene homopolymer, a silane functionalized polyethylene homopolymer, an ethylene / alpha-olefin copolymer, and a silane functionalized ethylene / alpha-olefin copolymer; (C) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of greater than 5 mN / m; and (D) at least one ethylene propylene diene monomer copolymer; and an electrically conductive filler dispersed in only one of components A and at least two of the other polymers, wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D), and the ternary phase polymer composite is a heterophasic composite, i.e., each of the three polymer components exists in its own phase.

[0099] In an embodiment, the composition includes one or more additives. Such additives can be added to the composition before, during, and / or after processing. The amount of additive, by total weight of the composition, is typically in the range of about 0.01 wt% to about 3 wt%. Suitable additives include additional antioxidants, crosslinking agents including organic peroxides, cure accelerators, adjuvants, scorch retarders, and silanes.

[0100] In an embodiment, the composition has an electrical conductivity that is less than 9, or less than 7, or less than 5, or less than 4, or less than 3, defined as the log ratio of the volume resistivity in ohm-cm to the percent loading of the conductive filler (vol%).

[0101] In an embodiment, the composition exhibits no brittle fracture at room temperature.

[0102] In an embodiment, the composition includes at least one crosslinking component, i.e., at least one of component (B), component (C), and component (D) is present in the composition and is crosslinked.

[0103] Methods of forming a composition

[0104] In an embodiment, the present disclosure provides a method of forming a composition comprising a ternary phase polymer composite, the ternary phase polymer composite comprising components: (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) less than or equal to 5 mN / m to greater than or equal to 1 mN / m; at least two other polymers selected from the group consisting of: (B) at least one non-polar polymer having a polar component with a surface tension (γ P ) greater than or equal to 0.0 mN / m to less than 1 mN / m, and which is selected from the group consisting of: a polyethylene homopolymer, a silane-functionalized polyethylene homopolymer, an ethylene / alpha-olefin copolymer, and a silane-functionalized ethylene / alpha-olefin copolymer; (C) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) greater than 5 mN / m; and (D) at least one ethylene propylene diene monomer copolymer; and a conductive filler dispersed in only one of component (A) and at least two other polymers, wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D).

[0105] In an embodiment, component (A) and at least two other polymers are melt blended together with the electrically conductive filler. Specifically, in an embodiment, the method comprises melt blending with the electrically conductive filler: (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) less than or equal to 5 mN / m to greater than or equal to 1 mN / m; at least two other polymers selected from the group consisting of: (B) at least one non-polar polymer having a polar component with a surface tension (γ P ) greater than or equal to 0.0 mN / m to less than 1 mN / m, and which is selected from the group consisting of: polyethylene homopolymer, silane functionalized polyethylene homopolymer, ethylene / alpha-olefin copolymer, and silane functionalized ethylene / alpha-olefin copolymer; (C) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) greater than 5 mN / m; and (D) at least one ethylene propylene diene monomer copolymer.

[0106] Preferably, the electrically conductive filler is melt blended with one of (A), (B), (C), and (D) to form a master mixture. Subsequently, the master mixture is melt blended with the remaining two components of (A), (B), (C), and (D). In an embodiment, the electrically conductive filler is melt blended with (A) to form a master mixture. Subsequently, the master mixture is melt blended with: (i) one of (B) and (C) or (D); or (ii) one of (C) and (B) or (D).

[0107] In an embodiment, the electrically conductive filler is present in the master mixture in an amount greater than or equal to 10 wt%, or greater than or equal to 15 wt%, or greater than or equal to 20 wt%, or greater than or equal to 25 wt%, or greater than or equal to 30 wt% to less than or equal to 50 wt%, or to less than or equal to 40 wt%, or to less than or equal to 35 wt%.

[0108] Optionally, additional additives can be added prior to, during, or after melt blending.

[0109] Cable

[0110] The present disclosure also provides a cable, such as a power cable, comprising a layer (e.g., a semiconductive layer) comprising a composite composition as described herein.

[0111] In one embodiment, the present disclosure provides a cable, such as a power cable, comprising a conductor and a semiconductive layer covering at least a portion of the conductor, the semiconductive layer comprising a composite composition as described herein. Preferably, the cable comprises a conductor, a semiconductive inner layer covering at least a portion of the conductor, an insulating layer covering at least a portion of the semiconductive inner layer, and a semiconductive outer layer covering at least a portion of the insulating layer, wherein at least one of the semiconductive inner layer and the semiconductive outer layer comprises a composite composition as described herein.

[0112] In one embodiment, the semiconductive inner layer and / or the semiconductive outer layer comprises a composition comprising a ternary phase polymer composite comprising components: (A) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of less than or equal to 5 mN / m to greater than or equal to 1 mN / m; at least two other polymers selected from the group consisting of: (B) at least one non-polar polymer having a polar component with a surface tension (γ P ) of greater than or equal to 0.0 mN / m to less than 1 mN / m, and which is selected from the group consisting of: a polyethylene homopolymer, a silane functionalized polyethylene homopolymer, an ethylene / alpha-olefin copolymer, and a silane functionalized ethylene / alpha-olefin copolymer; (C) at least one copolymer of ethylene and an unsaturated ester, the copolymer having a polar component with a surface tension (γ P ) of greater than 5 mN / m; and (D) at least one ethylene propylene diene monomer copolymer; and an electrically conductive filler dispersed in only one of components (A) and the at least two other polymers, wherein (i) a first of the at least two other polymers is selected from (B) and a second of the at least two other polymers is selected from (C) or (D), or (ii) a first of the at least two other polymers is selected from (C) and a second of the at least two other polymers is selected from (B) or (D).

[0113] In one embodiment, the present disclosure provides a method of conducting electricity, the method comprising applying a voltage across a cable as disclosed herein.

[0114] Definitions

[0115] Unless stated to the contrary, all test methods are current as of the filing date of this disclosure.

[0116] As used herein, the term "composition" includes a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0117] As used herein, the term "polymer" refers to a polymeric compound prepared by polymerizing identical or different types of monomers. The general term polymer thus encompasses the term homopolymer (used to refer to a polymer prepared from only one type of monomer, it being appreciated that trace amounts of impurities can be incorporated into the polymer structure) and the term copolymer as defined below. Trace amounts of impurities, such as catalyst residues, can be incorporated into and / or within the polymer. As used herein, the term "copolymer" refers to a polymer prepared by polymerization of at least two different types of monomers. The general term copolymer thus includes dimers (used to refer to polymers prepared from two different types of monomers) and polymers prepared from more than two different types of monomers.

[0118] The terms "comprising", "including", "having" and their derivatives, are not intended to exclude any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the terms "comprising", "including" or "having" and their derivatives, are intended to include any additional additive, adjuvant or compound, whether or not the same is specifically disclosed. In contrast, the term "consisting essentially of" does not include any additional component, step or procedure not recited in the claim after the phrase "consisting essentially of." The term "consisting of means excluding any component, step or procedure not specifically recited in the claim. The term "or", unless stated otherwise, means any one member of the conjuncted class. The use of the singular includes use of the plural and vice versa.

[0119] Test Methods

[0120] Low resistance (<10 8 Ohm (Ω)) measurements: Low resistance measurements were performed using a Keithley 2700 Integra Series digital multimeter with a 20-point probe. At least two samples (101.6 mm long x 50.8 mm wide x 1.9 mm thick) were tested for each formulation. Resistivity of the polymer composite was obtained from the compression molded samples. Silver paint (conductive silver #4817N) was applied to minimize the contact resistance between the sample and the electrodes.

[0121] High resistance (>10 8 Ohm (Ω) measurements: High resistance measurements were performed using a Keithley Model 6517B electrometer high resistance meter and Model 8009 resistivity test cell using circular disc samples with a diameter of 76.2 mm and a thickness of 1.9 mm.

[0122] Volume resistivity:

[0123] Brittleness: The brittleness of the composites was tested by bending rectangular specimens 25.4 mm wide and 203.2 mm long under load until the ends met.

[0124] experiment

[0125] The polymers, compositions and processes of the present disclosure and their uses are more fully described by the following examples.The following examples are provided for the purpose of illustrating the present disclosure and should not be construed as limiting the scope of the invention.

[0126] Material

[0127] PP: Polypropylene homopolymer (MFR (I 2.16 )=1.8g / 10min;Density=0.935g / cc)

[0128] PMMA: poly(methyl methacrylate) (MFR at 230°C (I 2.16 )=12.1g / 10min;density=1.180g / cc)

[0129] EAA-CB: Ethyl Acrylic Acid / Carbon Black Masterbatch

[0130] EAA: Ethyl acrylic acid (MFR (I at 230 ° C) 2.16 )=8.5g / 10min;Density=0.938g / cc)

[0131] Si-LDPE: Ethylene-vinyltrimethoxysilane copolymer (MFR at 230°C (I 2.16 )=1.5g / 10min;density=0.920g / cc)

[0132] EPDM: ethylene propylene diene monomer rubber; a semicrystalline hydrocarbon rubber (Mooney viscosity = 18 at 125°C) having a diene content of 0.9 wt% based on the weight of EPDM

[0133] LDPE: Low density polyethylene (MFR (I 2.16 )=2.3g / 10min;Density=0.920g / cc)

[0134] EVA: Ethylene vinyl acetate (MFR at 230°C (I 2.16 )=3.0g / 10min;Density=0.956g / cc)

[0135] EEA: Ethylene ethyl acrylate (MFR (I at 230 ° C) 2.16) = 20 g / 10 min; density = 0.930 g / cc)

[0136] EEA-CB: ethylene-ethyl acrylate / carbon black masterbatch

[0137] Surface energy data for the polymers listed above are provided in Table 1 below.

[0138] Table 1: Surface Energy Data

[0139]

[0140] D. W. van Krevelen and Klaas te Nijenhuis, Properties of Polymers: Their Correlation with Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions, p. 240 (2009 revision, 4th edition)

[0141] Comparative Examples 1-6 were prepared with the formulations set forth in Table 2 below. The comparative PP / PMMA / (EAA-CB) composites were prepared similar to known prior art methods and were used to show the brittleness of the prior art systems. The conductive carbon black (CB) was pre-mixed within the EAA polymer phase to form an EAA-CB masterbatch having a CB content of 9.3 vol% based on the total volume of the masterbatch. The masterbatch was prepared by melt mixing using a 250 cc internal C. W. Brabender batcher. The EAA polymer and CB were directly loaded into the mixing bowl of the batcher and compounded at 130 °C for 10 minutes at 60 rpm. The EAA-CB masterbatch was combined with the other two polymers in the batcher and mixed at 190 °C for 5 minutes at 60 rpm. The sample was then removed. The composites were then compression molded into 8 inch x 8 inch x 0.075 inch plaques. The polymer composites were compression molded at 135 °C and 3.45 MPa for 5 minutes. After 5 minutes, the pressure was increased to 17 MPa and then heat annealed at 190 °C for 30 minutes. The sample was then cooled to 30 °C and removed from the press.

[0142] Comparative Examples 7-10 were prepared using a method similar to that used to prepare Comparative Examples 1-6 with formulations as set forth in Table 1 below. The EAA-CB masterbatch was prepared as described for Comparative Examples 1-6 and then mixed with EEA to produce a single phase composite. The EAA-CB masterbatch was melt mixed with EEA at 135°C and at 40 rpm for 5 minutes. The sample was then removed. The composite was compression molded into 8 inch x 8 inch x 0.075 inch plaques. The polymer composite was compression molded at 135°C and 3.45 MPa for 5 minutes. After 5 minutes, the pressure was increased to 17 MPa and then heat annealed at 135°C for 15 minutes. The sample was then cooled to 30°C and removed from the press.

[0143] Inventive Examples 1-16 were prepared with formulations as set forth in Table 1 below. For the Inventive Examples, the conductive carbon black was pre-mixed with the EEA polymer phase to form an EAA-CB masterbatch having a CB content of 20 vol% based on the total volume of the masterbatch. The masterbatch was prepared by melt mixing using a 250 cc internal C. W. Brabender batch pre-mixer. The EAA and CB were loaded directly into the mixing bowl of the batch pre-mixer and compounded at 130°C at 60 rpm for 10 minutes. The masterbatch was combined with the other two polymers in the batch pre-mixer and mixed at 135°C at 40 rpm for 5 minutes. The sample was then removed. The composite was then compression molded into 8 inch x 8 inch x 0.075 inch plaques. The polymer composite was compression molded at 135°C and 3.45 MPa for 5 minutes. After 5 minutes, the pressure was increased to 17 MPa and then heat annealed at 135°C for 15 minutes. The sample was then cooled to 30°C and removed from the press.

[0144] Table 2: Formulations of Comparative and Inventive Examples

[0145] PP PMMA EAA-CB EEA Si-LDPE EPDM LDPE EVA EEA-CB CE1 48.75 48.75 2.50 CE2 47.25 47.25 5.50 CE3 45.75 45.75 8.50 CE4 44.50 44.50 11.00 CE5 42.00 42.00 16.00 CE6 40.00 40.00 20.00 CE7 2.50 97.50 CE8 10.00 90.00 CE9 20.00 80.00 CE10 40.00 60.00 IE1 48.75 48.75 2.50 IE2 46.25 46.25 7.50 IE3 42.50 42.50 15.00 IE4 37.50 37.50 25.00 IE5 48.75 48.75 2.50 IE6 46.25 46.25 7.50 IE7 42.50 42.50 15.00 IE8 37.50 37.50 25.00 IE9 48.75 48.75 2.50 IE10 46.25 46.25 7.50 IE11 42.50 42.50 15.00 IE12 37.50 37.50 25.00 IE13 48.75 48.75 2.50 IE14 46.25 46.25 7.50 IE15 42.50 42.50 15.00 IE16 37.50 37.50 25.00

[0146] The results of the composites (Comparative and Inventive Examples) are shown in Table 3. Unlike Comparative Examples 1-6 (PP + PMMA + EAA-CB masterbatch), the Inventive Examples exhibit a reduced percolation threshold and achieve electrical conductivity at lower CB loadings. In addition, the Inventive Examples exhibit a higher electrical conductivity than the Comparative Examples at the same CB loading. Figure 1The reduced permeation threshold is especially visible. Breaks and cracks were observed for inventive examples and comparative examples 7-10 when placed under load. The results show an improvement for inventive examples over prior art single polymer systems. Specifically, inventive examples show an improvement over such prior art systems in that they have lower melting and glass transition temperatures, resulting in systems that are less affected in terms of ductility / less elastic than those of PP / PMMA systems, which have melting and glass transition temperatures above the process limit and result in extremely brittle materials that are not suitable for many applications.

[0147] Table 3: Composite properties

[0148]

Claims

1. A composition comprising: a ternary phase polymer composite comprising (A) and two other polymers selected from the group consisting of (B), (C) and (D): (A) from 1 vol% to 30 vol%, based on the total volume of the composition, of at least one ethylene-ethyl acrylate copolymer having a surface tension γ P less than or equal to 5 millinewtons per meter (mN / m) to greater than or equal to 1 mN / m of polar component; (B) 35 vol% to 50 vol%, based on the total volume of the complex, of at least one polar component having a surface tension γ P a non-polar polymer of a polar component greater than or equal to 0 mN / m to less than 1 mN / m, and selected from the group consisting of polyethylene homopolymers and silane functionalized polyethylene homopolymers; (C) 35 vol% to 50 vol%, based on the total volume of the compound, of at least one ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer having a surface tension γ P a polar component greater than 5 mN / m; and (D) at least one EPDM terpolymer in an amount of 35 vol% to 50 vol% based on the total volume of the composite; and 0.25 vol% to 20 vol% of an electrically conductive filler dispersed only in component (A) based on the total volume of the ternary phase polymer composite, wherein the composition does not exhibit brittle fracture at room temperature.

2. The composition according to claim 1, wherein the electrically conductive filler is selected from the group consisting of carbon black, carbon nanotubes, graphite, graphene and combinations thereof.

3. The composition according to claim 1 or 2, wherein component (B) is present.

4. A cable comprising a semiconductive layer comprising the composition according to any one of claims 1 to 3.

5. A cable comprising: a conductor; a semiconductive inner layer covering at least a portion of the conductor; an insulation layer covering at least a portion of the semiconductive inner layer; and a semiconductive outer layer covering at least a portion of the insulation layer; and wherein at least one of the semiconductive inner layer and the semiconductive outer layer comprises a ternary phase polymer composite comprising (A) and two other polymers selected from the group consisting of (B), (C) and (D): (A) from 1 vol% to 30 vol%, based on the total volume of the composition, of at least one ethylene-ethyl acrylate copolymer having a surface tension γ P a polar component of less than or equal to 5 millinewtons per meter (mN / m) to greater than or equal to 1 mN / m; (B) 35 vol% to 50 vol%, based on the total volume of the complex, of at least one polar component having a surface tension γ P a non-polar polymer of a polar component greater than or equal to 0 mN / m to less than 1 mN / m, and selected from the group consisting of polyethylene homopolymers and silane functionalized polyethylene homopolymers; (C) 35 vol% to 50 vol%, based on the total volume of the compound, of at least one ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer having a surface tension γ P a polar component greater than 5 mN / m; and (D) at least one EPDM terpolymer in an amount of 35 vol% to 50 vol% based on the total volume of the composite; and 0.25 vol% to 20 vol% of an electrically conductive filler dispersed only in component (A) based on the total volume of the ternary phase polymer composite, wherein the composite does not exhibit brittle fracture at room temperature.

6. A method of conducting electricity, the method comprising applying a voltage across the cable according to any one of claims 4 and 5.

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