Halogen-free flame-retardant polymer composition

Abstract

A polymer composition comprising, in weight percent of the polymer composition, (a) 10% to 30% by weight of a polyolefin elastomer, (b) 1% to 20% by weight of a polypropylene-based polymer, (c) greater than 1% to 20% by weight of a crystalline block composite, (d) 1% to 10% by weight of a maleated polyolefin elastomer, and (e) 40% to 80% by weight of a halogen-free flame-retardant filler.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to polymer compositions, and more specifically to compatibilized polymer compositions containing hydrated mineral fillers.

[0002] Introduction Polyolefin-based halogen free flame retardant (HFFR) cable jacket compositions are useful in a variety of applications where flame retardancy of the insulation / jacketing material is important. Flame retardancy is achieved by the addition of hydrated mineral fillers that dilute the concentration of flammable polymeric materials and decompose below the decomposition temperature of the polymer when exposed to heat. Decomposition of the hydrated mineral fillers releases water, thereby removing heat from the fire source. Traditional HFFR cable jacket compositions are used indoors, inside buildings, trains, cars, or anywhere people may be present.

[0003] The use of hydrated mineral fillers in polyolefin wire and cable formulations has many drawbacks, most of which stem from the relatively high levels of filler required to meet flame retardant specifications. It is not uncommon to have filler loadings of 60 weight percent (wt%) or 65 wt% in polyolefins. This filler loading affects the properties of HFFR cable jacket compositions, resulting in compounds with high density, limited flexibility, and reduced mechanical properties such as elongation at break.

[0004] Often, blends of different polymers must be used to allow for the incorporation of such high filler loadings while maintaining some mechanical properties. For example, polypropylene is often utilized to add strength to the cable jacket composition, while polyolefin elastomers allow for filler loading. Compatibilizers are used in systems where different polymers are blended together to increase the mixing and adhesion of the polymers. For example, WO 2017 / 100175 utilizes an ethylene-propylene diblock copolymer to compatibilize a propylene and high-density polyethylene (HDPE) system. However, given that the polymer phase of HFFR cable jackets is the minority phase, prior attempts and understanding teach that compatibilization efforts should be directed at increasing the compatibilization and adhesion of the polymer phase with the hydrated inorganic filler. For example, U.S. Patent Application Publication No. 2010 / 0319960(A1) discloses HFFR, olefin multi-block interpolymers that utilize a polar-monomer based compatibilizer to bond the HFFR and olefin multi-block interpolymer together. Still other multipolymer HFFR systems consider the advantage of being free of polymer phase compatibilizers. For example, WO 2011 / 079457(A1) explains that "Advantageously, the composition does not require, and in embodiments does not include, a compatibilizer (e.g., a functional polymer) between the PP and thermoplastic elastomer components."

[0005] As applications for HFFR cable jackets begin to expand into non-traditional areas, mechanical properties once considered non-relevant for HFFR cable jackets are becoming relevant. For example, environmental stress cracking (ESCR) is a mechanical property relevant for cable jackets exposed to moisture (e.g., outdoor and / or underlying cables), lack of moisture (e.g., desert environments), and wide temperature variations. As a result, traditional properties of HFFR cable jackets, such as "hot press" or "hot knife" indentation testing, must be evaluated in addition to other properties, such as ESCR, mechanical properties (e.g., tensile strength and elongation at break), and overall composition cost. Complicating this balance of properties is the fact that improving one property often comes at the expense of another, so achieving an acceptable balance of properties remains elusive.

[0006] It would therefore be surprising to find a cable jacket composition having an HFFR content of 40 wt. % or greater that exhibits an ESCR of greater than 1000 hours, a hot knife indentation of less than 50%, an elongation at break of greater than 70%, and a tensile strength of greater than 10 MPa. Summary of the Invention

[0007] The present invention provides polymer compositions having HFFR filler content of 40 wt.% or more that exhibit ESCR of more than 1000 hours, hot knife indentation of less than 50%, elongation at break of more than 70%, and tensile strength of 10 MPa or more. The present invention is particularly useful for cable jackets.

[0008] The present invention is the result of the discovery that, even though the polymer phase is the minority phase in the HFFR cable composition, effective compatibilization of multiple different polymer types within the polymer phase is effective in providing the balance of properties required for critical environments. By utilizing a maleic anhydride grafted compatibilizer to compatibilize the polyolefin elastomer with the HFFR filler, the HFFR filler is bound to the polymer phase. By using a crystalline block composite compatibilizer in the polypropylene and polyolefin elastomer polymer phases of the HFFR cable jacket, the polyolefin elastomer is more effectively bound to the polypropylene phase. Surprisingly, rather than simply increasing a single property of the resulting composition, the ESCR, tensile strength, elongation at break, and hot knife indentation properties are all improved. As a result, the HFFR cable jacket of the present invention can be utilized in applications other than conventional HFFR cable jackets.

[0009] The present invention is particularly useful for cable jackets.

[0010] According to a first aspect of the present disclosure, a polymer composition includes, in weight percentages of the polymer composition, (a) 10 wt% to 30 wt% of a polyolefin elastomer; (b) 1 wt% to 20 wt% of a polypropylene-based polymer; (c) greater than 1 wt% to 20 wt% of a crystalline block composite; (d) 1 wt% to 10 wt% of a maleated polyolefin elastomer; and (e) 40 wt% to 80 wt% of a halogen-free flame-retardant filler. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As used herein, the term "and / or," when used with a list of two or more items, means that any one of the listed items can be used by itself, or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone, B alone, C alone, A and B in combination, A and C in combination, B and C in combination, or A, B, and C in combination.

[0012] Unless otherwise stated, all ranges are inclusive of the endpoints. The subscript values ​​in polymer formulas refer to the average number of moles of units per molecule of the specified component of the polymer.

[0013] Test methods refer to the most current test method as of the priority date of this document unless a date is indicated with a two-digit number with a hyphen in the test method number. References to test methods include both a reference to the testing organization and the test method number. Test method organizations are referred to by one of the following abbreviations: ASTM refers to ASTM International (formerly known as the American Society for Testing and Materials), EN refers to European Norm, DIN refers to Deutsches Institut fur Normung, ISO refers to the International Organization for Standards, and IEC refers to the International Electrotechnical Commission.

[0014] As used herein, the term weight percent ("wt %"), unless otherwise specified, refers to the weight percentage that a component represents of the total weight of the polymer composition.

[0015] As used herein, an "elastomer" is a rubber-like polymer having a modulus of less than or equal to about 10,000 psi and an elongation of greater than 200% at 23° C. in an uncrosslinked state using the method of ASTM D638-72.

[0016] As used herein, the term "halogen-free" means that the object or material contains no more than 2000 mg / kg of halogen as measured by ion chromatography (IC). Halogen content below this amount is not believed to be significant to the effectiveness of the composition as a wire or cable covering and may therefore be referred to as "halogen-free."

[0017] Polymer Composition The polymer composition of the present invention comprises a polyolefin elastomer, a polypropylene-based polymer, a crystalline block composite, a maleated polyolefin elastomer, and a halogen-free flame retardant filler.

[0018] Polyolefin Elastomer Polyolefin elastomers are elastomers that can include ethylene-based elastomers / plastomers, ethylene block copolymers, and propylene-based elastomers.

[0019] Polyolefin elastomers may include α-olefin block copolymers. "Olefin block copolymer" refers to a polymer that contains two or more chemically distinct regions or segments (referred to as "blocks") joined in a linear fashion, i.e., chemically distinct units that are joined end-to-end with respect to polymerized olefinic, preferably ethylenic, functional groups, rather than in a pendant or grafted fashion. The blocks differ in the amount or type of incorporated comonomer, density, degree of crystallinity, crystallite size, type or degree of stereoregularity (isotactic or syndiotactic), regioregularity or regioirregularity, degree of branching (including long chain branching or hyperbranching), homogeneity, or any other chemical or physical property that may be attributed to a polymer of such composition.

[0020] Suitable monomers for use in preparing the olefin block copolymers may include olefin or diolefin comonomers. Examples of suitable comonomers include linear or branched α-olefins of 2 to 30 carbon atoms. Suitable branched α-olefins include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene; cycloolefins of 3 to 30, preferably 3 to 20, carbon atoms, such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, and 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octadecene. dronaphthalene; di- and poly-olefins such as butadiene, isoprene, 4-methyl-1,3-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene, 1,3-hexadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, ethylidene norbornene, vinyl norbornene, dicyclopentadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, and 5,9-dimethyl-1,4,8-decatriene.

[0021] Examples of olefin block copolymers useful in the practice of the present invention as polyolefin elastomers are commercially available as INFUSE™ D9100, D9500 D9507, or D9530 olefin block copolymers from The Dow Chemical Company, Midland, Michigan, USA.

[0022] The polyolefin elastomer may comprise an elastomeric ethylene homopolymer or an ethylene and α-olefin random copolymer. The α-olefin of the ethylene and α-olefin copolymer may have 3 to 12 carbon atoms and preferably 3 to 8 carbon atoms. Preferably, the α-olefin is one or more of 1-butene, 1-hexene, and 1-octene. The ethylene polymers used in the practice of the invention may comprise units derived from three or more different monomers. For example, the third comonomer may be another α-olefin or a diene such as ethylidene norbornene, butadiene, 1,4-hexadiene, or dicyclopentadiene.

[0023] Examples of ethylene polymers useful in the practice of the present invention include homogeneously branched linear ethylene / alpha-olefin copolymers, such as TAFMER™ copolymers from Mitsui Petrochemicals Company Limited, New York, NY, USA, and EXACT™ copolymers by Exxon Chemical Company. Examples of homogeneously branched substantially linear ethylene and α-olefin polymers include AFFINITY™ plastomers, ENGAGE™ elastomers, and SEC 39001 ethylene-butene copolymers available from The Dow Chemical Company, Midland, MI, USA. Such polyolefin elastomeric resins may be prepared with at least one metallocene catalyst, or blends of multiple elastomeric resins may be prepared with different metallocene catalysts. In some embodiments, the elastomer is a substantially linear ethylene polymer (SLEP). SLEP and other metallocene catalyzed elastomers are known in the art, for example, U.S. Pat. No. 5,272,236.

[0024] Polyolefin elastomers comply with ASTM D792, of 0.86 grams per cubic centimeter or more, or 0.87 g / cc or more, or 0.88 g / cc or more, or 0.89 g / cc or more, or 0.90 g / cc or more, or 0.91 g / cc or more, or 0.92 g / cc or more, or 0.93 g / cc or more, or 0.94 g / cc or more, or 0.95 g / cc or more, 0.96 g / cc or more, while at the same time, 0.97 g / cc or less, or 0.965 g / cc or less, or 0.96 g / cc or less, or 0.95 g / cc or less, or 0.94 g / cc or less, or 0.93 g / cc or less, or 0.92 g / cc or less, or 0.91 g / cc or less, or 0.90 g / cc or less, or 0.89 g / cc or less, or 0.88 g / cc or less, or 0.87 g / cc or less.

[0025] The polyolefin elastomer has a modulus of 1 gram per 10 minutes (g / 10 min) or more, or 2 g / 10 min or more, 3 g / 10 min or more, 4 g / 10 min or more, 5 g / 10 min or more, 6 g / 10 min or more, 7 g / 10 min or more, 8 g / 10 min or more, 9 g / 10 min or more, 10 g / 10 min or more, or 11 g / 10 min or more, or 12 g / 10 min or more, 13 g / 10 min or more, 14 g / 10 min or more, 15 g / 10 min or more, 16 g / 10 min or more, 17 g / 10 min or more, 18 g / 10 min or more, 1 g / 10 min or more, while simultaneously having a modulus of 20 g / 10 min or more or less, or 19 g / 10 min. or less, or 18 g / 10 min. or less, or 17 g / 10 min. or less, or 16 g / 10 min. or less, or 15 g / 10 min. or less, or 14 g / 10 min. or less, or 13 g / 10 min. or less, or 12 g / 10 min. or less, or 11 g / 10 min. or less, or 10 g / 10 min. or less, or 9 g / 10 min. or less, or 8 g / 10 min. or less, or 7 g / 10 min. or less, or 6 g / 10 min. or less, or 5 g / 10 min. or less, or 4 g / 10 min. or less, or 3 g / 10 min. or less, or 2 g / 10 min. or less. MFI is measured at 190° C. and 2.16 kg according to ASTM D1238.

[0026] The polymer composition comprises 10 wt% or more, or 11 wt% or more, or 12 wt% or more, or 13 wt% or more, or 14 wt% or more, or 15 wt% or more, or 16 wt% or more, or 17 wt% or more, or 18 wt% or more, or 19 wt% or more, or 20 wt% or more, or 21 wt% or more, or 22 wt% or more, or 23 wt% or more, or 24 wt% or more, or 25 wt% or more, or 26 wt% or more, or 27 wt% or more, or 28 wt% or more, or 29 wt% or more, while at the same time It may contain 30% by weight or less, or 29% by weight or less, or 28% by weight or less, or 27% by weight or less, or 26% by weight or less, 25% by weight or less, or 24% by weight or less, or 23% by weight or less, or 22% by weight or less, or 21% by weight or less, or 20% by weight or less, or 19% by weight or less, or 18% by weight or less, or 17% by weight or less, or 16% by weight or less, 15% by weight or less, or 14% by weight or less, or 13% by weight or less, or 12% by weight or less, or 11% by weight or less of polyolefin elastomer.

[0027] Polypropylene-based polymer The polymer composition comprises a propylene-based polymer. As used herein, a "propylene-based polymer" is a polymer that contains more than 50% by weight of polymerized propylene monomer (based on the total amount of polymerizable monomers) and may optionally contain one or more comonomers. The terms "propylene-based polymer" and "polypropylene" may be used interchangeably. Propylene-based polymers include propylene homopolymers and propylene copolymers (meaning units derived from propylene and one or more comonomers). As used herein, a "propylene homopolymer" refers to a polymer that consists solely of polymerized propylene monomers or that is essentially all polymerized propylene monomers. As used herein, a "propylene copolymer" refers to a polymer that consists essentially of polymerized propylene and ethylene, and / or C 4~20 C refers to a polymer containing units derived from one or more other unsaturated comonomers, such as linear, branched, or cyclic α-olefins. 4~20Examples of α-olefins include 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. For propylene copolymers, the comonomer content is 10% by weight or less, or 5% by weight or less, or 3% by weight or less. Common forms of polypropylene known in the art include homopolymer polypropylene (hPP), random copolymer polypropylene (rcPP), impact copolymer polypropylene (hPP+, at least one elastomeric impact modifier) ​​(ICPP) or high impact polypropylene (HIPP), high melt strength polypropylene (HMS-PP), isotactic polypropylene (iPP), syndiotactic polypropylene (sPP), and combinations thereof.

[0028] The polymer composition may comprise 1 wt% or more, or 2 wt% or more, or 3 wt% or more, or 4 wt% or more, or 5 wt% or more, or 6 wt% or more, or 7 wt% or more, or 8 wt% or more, or 9 wt% or more, or 10 wt% or more, or 11 wt% or more, or 12 wt% or more, or 13 wt% or more, or 14 wt% or more, or 15 wt% or more, or 16 wt% or more, or 17 wt% or more, or 18 wt% or more, or 19 wt% or more, while simultaneously by weight or less, or 20% or less, or 19% or less, or 18% or less, or 17% or less, or 16% or less, or 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less of polypropylene.

[0029] The propylene-based polymer may have a viscosity of 1g / 10min or more, or 2g / 10min or more, 3g / 10min or more, 4g / 10min or more, 5g / 10min or more, 6g / 10min or more, 7g / 10min or more, 8g / 10min or more, 9g / 10min or more, 10g / 10min or more, or 11g / 10min or more, or 12g / 10min or more, 13g / 10min or more, 14g / 10min or more, 15g / 10min or more, 16g / 10min or more, 17g / 10min or more, 18g / 10min or more, 19g / 10min or more, while at the same time being 20g / 10min or less, or 19g / 10min or less, or 18g / 10min or less, or 17g / 10min or less, or 16g / 10min or less, or 15g / 10min or less, or 14g / 10min or less, or 13g / 10min or less, or 12g / 10min or less, or 11g / 10min or less, or 10g / 10min or less, or 9g / 10min or less, or 8g / 10min or less, or 7g / 10min or less, or 6g / 10min or less, or 5g / 10min or less, or 4g / 10min or less, or 3g / 10min or less, or 2g / 10min or less. MFI is measured according to ASTM D1238 at 230°C and 2.16 kg.

[0030] Polypropylene homopolymers useful in the practice of the invention are commercially available as H700-12 polypropylenes available from either The Dow Chemical Company, Midland, Michigan, USA or Braskem America, Philadelphia, Pennsylvania, USA. Copolymer polypropylenes, including random copolymer polypropylene resins useful in the practice of the invention, are commercially available as DS6D82, 6D83K, and C715-12NHP polypropylenes available from The Dow Chemical Company, Midland, Michigan, USA. Impact modified propylene copolymers useful in the practice of the invention are commercially available as C766-03, C7057-07, C7061-01N, and C706-21NA HP polypropylenes available from The Dow Chemical Company, Midland, Michigan, USA.

[0031] Crystalline Block Complex The polymer composition comprises a crystalline block composite. The term "crystalline block composite" (CBC) refers to a material that is made up of three polymer components: (i) a crystalline ethylene-based polymer (CEP) having an ethylene content of 90 mole percent or more, based on the total moles of polymerized monomer units in the CEP; (ii) a crystalline alpha-olefin based polymer (CAOP) having an alpha-olefin content of greater than 90 mole percent, based on the total moles of polymerized monomer units in the CAOP; (iii) a block copolymer including a crystalline ethylene block (CEB) and a crystalline alpha-olefin block (CAOB), The crystalline ethylene block has the same or similar melting temperature (Tm) as the CEP of component (i); The crystalline alpha-olefin block has the same or similar Tm as component (ii) CAOP; The phrase "same or similar" refers to an absolute Tm difference of ≦5° C. as measured using differential scanning calorimetry (DSC) at a temperature ramping rate of 0.1° C. to 10° C.

[0032] Processes for making CBC and methods for analyzing CBC are described, for example, in U.S. Patent Application Publication Nos. 2011 / 0313106, 2011 / 0313108, and 2011 / 0313108, all published Dec. 22, 2011, and PCT Publication No. WO2014 / 043522(A1). Examples of suitable α-olefins include C3-C10 α-olefins, such as C3, C4, C5, C6, and C8 α-olefins. The α-olefin can be propylene.

[0033] A "crystalline ethylene-based polymer" ("CEP") is an ethylene-based polymer that contains 90 mol % or more of polymerized monomer units in the CEP and has no more than 10 mol % of any comonomer content of polymerized monomer units in the CEP.

[0034] A "crystalline alpha-olefin-based polymer" ("CAOP") is a crystalline polymer containing polymerized α-olefin units. The polymerized α-olefin units can be 1-propylene. The polymerized α-olefin units (e.g., propylene) are present in an amount of 90 mol % or more, or 93 mol % or more, or 95 mol % or more, or 98 mol % or more, based on the total weight of the crystalline α-olefin-based polymer (propylene). The comonomer can be ethylene. The comonomer content in the CAOP is 10 mol % or less. A CAOP with propylene crystallinity has a melting point of 80° C. or more. The CAOP can contain all or substantially all propylene units.

[0035] Other suitable α-olefin units (in addition to propylene) that may be used in the CAOP are those containing 4 to 10 carbon atoms, such as 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Suitable diolefins that may be used in the CAOP include isoprene, butadiene, 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, dicyclopentadiene, methylene-norbornene, 5-ethylidene-2-norbornene, and the like, and combinations containing at least one of the foregoing α-olefin units.

[0036] The block copolymer of CBC contains CEB and a crystalline alpha olefin block CAOB. In the CEB, polymerized ethylene is present in an amount of 90 mole % or more, based on the total moles of CEB. The CEB polymer can be polyethylene.

[0037] CAOB comprises polypropylene blocks copolymerized with other α-olefin units containing 4 to 10 carbon atoms. Polypropylene is present in CAOB in an amount of 90 mole % or more, based on the total moles of CAOB. The comonomer content in CAOB is 10 mole % or less, based on the total moles of CAOB. CAOB with propylene crystallinity has a melting point of 80° C. or more. In some embodiments, CAOB comprises all or substantially all propylene units.

[0038] The CBC may contain propylene, 1-butene, or 4-methyl-1-pentene, and one or more comonomers. The CBC may contain, in polymerized form, propylene and ethylene, and / or one or more C4-20 α-olefin comonomers, and / or one or more additional copolymerizable comonomers, or the CBC contains 4-methyl-1-pentene and ethylene, and / or one or more C4-20 α-olefin comonomers, or the CBC contains 1-butene and ethylene, propylene, and / or one or more C5-C20 α-olefin comonomers, and / or one or more additional copolymerizable comonomers. Additional suitable comonomers are selected from diolefins, cyclic olefins, and cyclic diolefins, halogenated vinyl compounds, and vinylidene aromatic compounds. The monomer may be propylene and the comonomer may be ethylene.

[0039] The CBC may be a propylene-based polymer containing 50% or more by weight of propylene-derived units, based on the total weight of the CBC. The comonomer content in the CBC may be measured using nuclear magnetic resonance (NMR) spectroscopy.

[0040] CBC is 1g / 10min or more, 2g / 10min or more, 3g / 10min or more, 4g / 10min or more, 5g / 10min or more, 6g / 10min or more, 7g / 10min or more, 8g / 10min or more, 9g / 10min or more, 9.5g / 10min or more, 10g / 10min or more, 11g / 10min or more, 12g / 10min or more, 13g / 10min or more, 14g / 10min or more, 15g / 10min or more, 16g / 10min or more, 17g / 10min or more, 18g / 10min or more, 19g / 10min or more, while simultaneously 20g / 10min or more or less, or 19g / 10min or less, or 18g / 10min or less, or 17g / 10min or less, or 16g / 10min or less, or 15g / 10min or less, or 14g / 10min or less, or 13g / 10min or less, or 12g / 10min or less, or 11g / 10min or less, or 10g / 10min or less, or 9g / 10min or less, or 8g / 10min or less, or 7g / 10min or less, or 6g / 10min or less, or 5g / 10min or less, or 4g / 10min or less, or 3g / 10min or less, or 2g / 10min or less. MFI is measured according to ASTM D1238 at 230°C and 2.16 kg.

[0041] The CBC is 10,000 g / mol or more, or 20,000 g / mol or more, or 30,000 g / mol or more, or 40,000 g / mol or more, or 50,000 g / mol or more, or 60,000 g / mol or more, or 70,000 g / mol or more, or 80,000 g / mol or more, or 90,000 g / mol or more, or 100,000 g / mol or more , or 110,000 g / mol or more, or 120,000 g / mol or more, or 130,000 g / mol or more, or 140,000 g / mol or more, or 150,000 g / mol or more, or 160,000 g / mol or more, or 170,000 g / mol or more, or 180,000 g / mol or more, or 190,000 g / mol or more, while at the same time, weight average molecular weight (Mw) of 0,000 g / mol or less, or 190,000 g / mol or less, or 180,000 g / mol or less, or 170,000 g / mol or less, or 160,000 g / mol or less, or 150,000 g / mol or less, or 140,000 g / mol or less, or 130,000 g / mol or less, or 120,000 g / mol or less, or 110,000 g / mol or less, or 100,000 g / mol or less, or 90,000 g / mol or less, or 80,000 g / mol or less, or 70,000 g / mol or less, or 60,000 g / mol or less, or 50,000 g / mol or less, or 40,000 g / mol or less, or 30,000 g / mol or less, or 20,000 g / mol or less The weight average molecular weight is measured using gel permeation chromatography.

[0042] The sum of the weight percentages of CEP, CAOP, and block copolymer in the CBC equals 100%. The CBC can be 0.5% by weight or more, or 1% by weight or more, or 5% by weight or more, or 10% by weight or more, or 20% by weight or more, or 30% by weight or more, or 40% by weight or more, or 50% by weight or more, or 60% by weight or more, or 70% by weight or more, or 80% by weight or more, while at the same time 90% by weight or less, or 80% by weight or less, or 70% by weight or less, or 60% by weight or less, or 50% by weight or less, or 40% by weight or less, or 30% by weight or less, or 20% by weight or less, or 10% by weight or less of CEP.

[0043] The CBC can be 0.5% by weight or more, or 1% by weight or more, or 5% by weight or more, or 10% by weight or more, or 20% by weight or more, or 30% by weight or more, or 40% by weight or more, or 50% by weight or more, or 60% by weight or more, or 70% by weight or more, or 80% by weight or more, while at the same time 90% by weight or less, or 80% by weight or less, or 70% by weight or less, or 60% by weight or less, or 50% by weight or less, or 40% by weight or less, or 30% by weight or less, or 20% by weight or less, or 10% by weight or less of the CAOP.

[0044] The CBC can be 0.5% by weight or more, or 1% by weight or more, or 5% by weight or more, or 10% by weight or more, or 20% by weight or more, or 30% by weight or more, or 40% by weight or more, or 50% by weight or more, or 60% by weight or more, or 70% by weight or more, or 80% by weight or more, while at the same time being 90% by weight or less, or 80% by weight or less, or 70% by weight or less, or 60% by weight or less, or 50% by weight or less, or 40% by weight or less, or 30% by weight or less, or 20% by weight or less, or 10% by weight or less of the block copolymer.

[0045] The block copolymer of CBC may contain 0.5% by weight or more, or 1% by weight or more, or 5% by weight or more, or 10% by weight or more, or 20% by weight or more, or 30% by weight or more, or 40% by weight or more, or 50% by weight or more, or 60% by weight or more, or 70% by weight or more, or 80% by weight or more, while at the same time 90% by weight or less, or 80% by weight or less, or 70% by weight or less, or 60% by weight or less, or 50% by weight or less, or 40% by weight or less, or 30% by weight or less, or 20% by weight or less, or 10% by weight or less of crystalline ethylene blocks (CEB). The block copolymer of CBC may contain 0.5% or more, or 1% or more, or 5% or more, or 10% or more, or 20% or more, or 30% or more, or 40% or more, or 50% or more, or 60% or more, or 70% or more, or 80% or more, while at the same time 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 10% or less by weight of crystalline alpha-olefin block (CAOB).

[0046] The CBC may contain (i) a crystalline ethylene / propylene copolymer (CEP), (ii) a CAOP, which is an isotactic crystalline propylene homopolymer (iPP), and (iii) a block copolymer containing an iPP block (CAOB) and an ethylene / propylene block (CEB), wherein the block copolymer comprises a diblock having the following formula (1): (CEP)-(iPP) Formula (1)

[0047] The polymer composition may comprise 1 wt% or more, or 2 wt% or more, or 3 wt% or more, or 4 wt% or more, or 5 wt% or more, or 6 wt% or more, or 7 wt% or more, or 8 wt% or more, or 9 wt% or more, or 10 wt% or more, or 11 wt% or more, or 12 wt% or more, or 13 wt% or more, or 14 wt% or more, or 15 wt% or more, or 16 wt% or more, or 17 wt% or more, or 18 wt% or more, or 19 wt% or more, while simultaneously , 20% or less, or 19% or less, or 18% or less, or 17% or less, or 16% or less, 15% or less, or 14% or less, or 13% or less, or 12% or less, or 11% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less by weight of crystalline block composite.

[0048] Maleated Polyolefin Elastomer The polymer composition comprises a maleated polyolefin elastomer. As used herein, the term "maleated" refers to an elastomer (e.g., a polyolefin elastomer) that has been modified to incorporate maleic anhydride monomer. The maleated polyolefin elastomer may be formed by copolymerizing maleic anhydride monomer with ethylene and other monomers (if present) to prepare an interpolymer having maleic anhydride incorporated into the polymer backbone. Additionally or alternatively, the maleic anhydride may be graft polymerized onto the polyolefin elastomer. The polyolefin elastomer to be maleated may be any of the polyolefin elastomers described above.

[0049] Maleated polyolefin elastomers comply with ASTM D792, the density may be 0.86 g / cc or more, or 0.87 g / cc or more, or 0.88 g / cc or more, or 0.89 g / cc or more, or 0.90 g / cc or more, or 0.91 g / cc or more, or 0.92 g / cc or more, or 0.93 g / cc or more, or 0.94 g / cc or more, or 0.95 g / cc or more, 0.96 g / cc or more, while at the same time being 0.97 g / cc or less, or 0.965 g / cc or less, or 0.96 g / cc or less, or 0.95 g / cc or less, or 0.94 g / cc or less, or 0.93 g / cc or less, or 0.92 g / cc or less, or 0.91 g / cc or less, or 0.90 g / cc or less, or 0.89 g / cc or less, or 0.88 g / cc or less, or 0.87 g / cc or less.

[0050] The maleated polyolefin elastomer may have a viscosity of 1g / 10min or more, or 2g / 10min or more, 3g / 10min or more, 4g / 10min or more, 5g / 10min or more, 6g / 10min or more, 7g / 10min or more, 8g / 10min or more, 9g / 10min or more, 10g / 10min or more, or 11g / 10min or more, or 12g / 10min or more, 13g / 10min or more, 14g / 10min or more, 15g / 10min or more, 16g / 10min or more, 17g / 10min or more, 18g / 10min or more, 19g / 10min or more, while at the same time, having a viscosity of 20g / 10 or less than 19g / 10min, or less than 18g / 10min, or less than 17g / 10min, or less than 16g / 10min, or less than 15g / 10min, or less than 14g / 10min, or less than 13g / 10min, or less than 12g / 10min, or less than 11g / 10min, or less than 10g / 10min, or less than 9g / 10min, or less than 8g / 10min, or less than 7g / 10min, or less than 6g / 10min, or less than 5g / 10min, or less than 4g / 10min, or less than 3g / 10min, or less than 2g / 10min. MFI is measured at 190°C and 2.16kg according to ASTM D1238.

[0051] The maleated polyolefin elastomer may have a maleic anhydride content of 0.25% by weight or more, or 0.50% by weight or more, or 0.75% by weight or more, or 1.00% by weight or more, or 1.25% by weight or more, or 1.50% by weight or more, or 1.75% by weight or more, or 2.00% by weight or more, or 2.25% by weight or more, or 2.50% by weight or more, or 2.75% by weight or more, while at the same time being 3.00% by weight or less, 2.75% by weight or less, or 2.50% by weight or less, or 2.25% by weight or less, or 2.00% by weight or less, or 1.75% by weight or less, or 1.50% by weight or less, or 1.25% by weight or less, or 1.00% by weight or less, or 0.75% by weight or less, or 0.5% by weight or less, based on the total weight of the maleated polyolefin elastomer. The maleic anhydride concentration is determined by titration analysis. Titration analysis is performed by utilizing the dry resin and titrating it with 0.02N KOH to determine the amount of maleic anhydride. The dry polymer is titrated by dissolving 0.3-0.5 grams of maleated polymer in approximately 150 mL of refluxing xylene. After complete dissolution, deionized water (4 drops) is added to the solution and the solution is refluxed for 1 hour. Next, 1% thymol blue (a few drops) is added to the solution and the solution is titrated with 0.02N KOH in ethanol as indicated by the formation of a purple color. The solution is then back-titrated with a solution of 0.05N HCl in isopropanol to a yellow endpoint.

[0052] The polymer composition may comprise 1 wt% or more, or 2 wt% or more, or 3 wt% or more, or 4 wt% or more, or 5 wt% or more, or 6 wt% or more, or 7 wt% or more, or 8 wt% or more, or 9 wt% or more, while at the same time 10 wt% or less, or 9 wt% or less, or 8 wt% or less, or 7 wt% or less, or 6 wt% or less, or 5 wt% or less, or 4 wt% or less, or 3 wt% or less, or 2 wt% or less of maleated polyolefin elastomer.

[0053] An example of a suitable commercially available maleated polyolefin elastomer is AMPLIFY™ GR216, available from The Dow Chemical Company, Midland, Mich., USA.

[0054] Halogen-Free Flame Retardant (HFFR) Fillers The halogen-free flame retardant of the polymer composition may inhibit, suppress, or delay the generation of flame. Examples of halogen-free flame retardants suitable for use in the compositions according to the present disclosure include, but are not limited to, metal hydroxides, red phosphorus, silica, alumina, aluminum hydroxide, magnesium dihydroxide, alumina trihydrate, aluminum hydroxide, titanium oxide, carbon nanotubes, talc, clay, organically modified clay, calcium carbonate, zinc borate, antimony trioxide, wollastonite, mica, ammonium octamolybdate, frits, hollow glass microspheres, expandable compounds, expanded graphite, and combinations thereof. In some embodiments, the halogen-free flame retardant may be selected from the group consisting of aluminum hydroxide, magnesium hydroxide, calcium carbonate, and combinations thereof. The halogen-free flame retardant may be optionally surface treated (coated) with a saturated or unsaturated carboxylic acid having 8 to 24 carbon atoms, or 12 to 18 carbon atoms, or a metal salt of the acid. Exemplary surface treatments are described in U.S. Patent No. 4,255,303, U.S. Patent No. 5,034,442, U.S. Patent No. 7,514,489, U.S. Patent Application Publication No. 2008 / 0251273, and WO 2013 / 116283. Alternatively, the acid or salt can simply be added to the composition in a similar amount, rather than using a surface treatment procedure. Other surface treatments known in the art, including silanes, titanates, phosphates, and zirconates, can also be used.

[0055] Commercially available examples of halogen-free flame retardants suitable for use in the compositions according to the present disclosure include, but are not limited to, APYRAL™ 40CD aluminum hydroxide available from Nabaltec AG, MAGNIFIN™ H5 magnesium hydroxide available from Magnifin Magnesiaprodukte GmbH&Co KG, and combinations thereof.

[0056] The polymer composition may have a molecular weight of 40% or more, or 42% or more, or 44% or more, or 46% or more, or 48% or more, or 50% or more, or 52% or more, or 54% or more, or 56% or more, or 58% or more, or 60% or more, or 62% or more, or 64% or more, or 66% or more, or 68% or more, or 70% or more, or 72% or more, or 74% or more, or 76% or more, or 78% or more, based on the weight of the polymer composition; At the same time, it may contain HFFR filler at a concentration of 80% by weight or less, or 78% by weight or less, or 76% by weight or less, or 74% by weight or less, or 72% by weight or less, or 70% by weight or less, or 68% by weight or less, or 66% by weight or less, or 64% by weight or less, or 62% by weight or less, or 60% by weight or less, or 58% by weight or less, or 56% by weight or less, or 54% by weight or less, or 52% by weight or less, or 50% by weight or less, or 48% by weight or less, or 46% by weight or less, or 44% by weight or less, or 42% by weight or less.

[0057] The HFFR filler has a particle size of 0.5 μm or more, or 0.6 μm or more, or 0.7 μm or more, or 0.8 μm or more, or 0.9 μm or more, or 1.0 μm or more, or 1.1 μm or more, or 1.2 μm or more, or 1.3 μm or more, or 1.4 μm or more, or 1.5 μm or more, or 1.6 μm or more, or 1.7 μm or more, or 1.8 μm or more, or 1.9 μm or more. , while at the same time, D of 2.0 μm or less, or 1.9 μm or less, or 1.8 μm or less, or 1.7 μm or less, or 1.6 μm or less, or 1.5 μm or less, or 1.4 μm or less, or 1.3 μm or less, or 1.2 μm or less, or 1.1 μm or less, or 1.0 μm or less, or 0.9 μm or less, or 0.8 μm or less, or 0.7 μm or less, or 0.6 μm or less 50 The particle size of the HFFR filler can be determined using static laser light scattering.

[0058] Additives The polymeric composition may contain additional additives in the form of antioxidants, crosslinking coagents, cure accelerators and scorch inhibitors, processing aids, coupling agents, UV stabilizers (including UV absorbers), antistatic agents, additional nucleating agents, slip agents, lubricants, viscosity modifiers, tackifiers, antiblocking agents, surfactants, extender oils, acid scavengers, flame retardants, and metal deactivators. The polymeric composition may contain from 0.01% to 10% by weight of one or more of the additional additives.

[0059] UV light stabilizers can include hindered amine light stabilizers ("HALS") and UV light absorber ("UVA") additives. Representative UVA additives include benzotriazole types such as TINUVIN 326™ and TINUVIN 328™ light stabilizers available from Ciba, Inc. Blends of HAL's and UVA additives are also effective.

[0060] Antioxidants include hindered phenols such as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydro-cinnamate)]methane; bis[(beta-(3,5-di-tert-butyl-4-hydroxybenzyl)methylcarboxyethyl)]-sulfide, 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-thiobis(2-tert-butyl-5-methylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), and thiodiethylenebis(3,5-di-tert-butyl-4-hydroxy)-hydrocinnamate; tris(2,4-di-tert-butylphenyl)phosphatase. phosphites and phosphonites such as sphite and di-tert-butylphenyl-phosphonite; thio compounds such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate; various siloxanes; polymeric 2,2,4-trimethyl-1,2-dihydroquinoline, n,n'-bis(1,4-dimethylpentyl-p-phenylenediamine), alkylated diphenylamines, 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine, diphenyl-p-phenylenediamine, mixed di-aryl-p-phenylenediamines, and other hindered amine antidegradants or stabilizers.

[0061] Processing aids may include metal salts of carboxylic acids such as zinc stearate or calcium stearate; fatty acids such as stearic acid, oleic acid, or erucic acid; fatty amides such as stearamide, oleamide, erucamide, or N,N'-ethylenebis-stearamide; polyethylene waxes; oxidized polyethylene waxes; polymers of ethylene oxide; copolymers of ethylene oxide and propylene oxide; vegetable waxes; petroleum waxes; non-ionic surfactants; silicone fluids and polysiloxanes.

[0062] Compounding and Cable Forming The components of the polymer composition may be added to a batch or continuous mixer for melt blending to form a melt blended composition. The components may be added in any order or by first preparing one or more masterbatches to blend with the other components. The melt blending may be performed at a temperature above the highest molten polymer. The melt blended composition may then be delivered to an extruder or injection molding machine or passed through a die to be molded into the desired article, or converted into pellets, tapes, strips, or films, or other forms for storage or preparation of the material to be fed to the next molding or processing step. Optionally, if molded into pellets or some similar configuration, the pellets or the like may be coated with an anti-blocking agent to facilitate handling during storage.

[0063] Examples of compounding equipment include internal batch mixers, such as BANBURY™ or BOLLING™ internal mixers. Alternatively, continuous single or twin screw mixers may be used, such as FARRELL™ continuous mixers, WERNER™ and PFLEIDERER™ twin screw mixers, or BUSS™ kneading continuous extruders. The type of mixer utilized, and the operating conditions of the mixer, affect the properties of the composition, such as viscosity, volume resistivity, and extrusion surface smoothness.

[0064] The polymer composition may be disposed on or positioned around a conductor to form a cable. As used herein, a "conductor" is one or more wires or one or more fibers for conducting heat, light, and / or electricity. The conductor may be a single wire / fiber or multiple wires / fibers, and may be in stranded or tubular form. Non-limiting examples of suitable conductors include carbon and various metals, such as silver, gold, copper, and aluminum. The conductor may also be an optical fiber made of either glass or plastic. The polymer composition may be used as a protective sheath to form a cable. The polymer composition is then extruded onto the conductor to form the cable. The polymer composition may be

[0065] Polymer composition properties The polymer composition may have a pressure of 10.0 MPa or more, or 10.5 MPa or more, or 11.0 MPa or more, or 11.5 MPa or more, or 12.0 MPa or more, or 12.5 MPa or more, or 13.0 MPa or more, or 13.5 MPa or more, or 14.0 MPa or more, or 14.5 MPa or more, or 15.0 MPa or more, or 15.5 MPa or more, or 16.0 MPa or more, or 16.5 MPa or more, or 17.0 MPa or more, or 17.5 MPa or more, or 18.0 MPa or more, or 18.5 MPa or more, or 19.0 MPa or more, or 19.5 MPa or more, while At times, the tensile strength may be 20.0 MPa or less, or 19.5 MPa or less, or 19.0 MPa or less, or 18.5 MPa or less, or 18.0 MPa or less, or 17.5 MPa or less, or 17.0 MPa or less, or 16.5 MPa or less, or 16.0 MPa or less, or 15.5 MPa or less, or 15.0 MPa or less, or 14.5 MPa or less, or 14.0 MPa or less, or 13.5 MPa or less, or 13.0 MPa or less, or 12.5 MPa or less, or 12.0 MPa or less, or 11.5 MPa or less, or 11.0 MPa or less, or 10.5 MPa or less. Tensile strength is determined according to the procedure described in the Test Methods section below.

[0066] The polymer composition may exhibit an elongation at break of 70% or more, or 75% or more, or 80% or more, or 85% or more, or 90% or more, or 95% or more, or 100% or more, or 105% or more, or 110% or more, or 115% or more, or 120% or more, or 125% or more, while at the same time being 130% or less, or 125% or less, or 120% or less, or 115% or less, or 110% or less, or 105% or less, or 100% or less, or 95% or less, or 90% or less, or 85% or less, or 80% or less, or 75% or less. The elongation at break modulus is determined according to the procedure described in the Test Methods section below.

[0067] The polymer composition may exhibit a flexural modulus of 200 MPa or more, or 210 MPa or more, or 220 MPa or more, or 230 MPa or more, or 240 MPa or more, or 250 MPa or more, or 260 MPa or more, or 270 MPa or more, or 280 MPa or more, or 290 MPa or more, or 300 MPa or more, or 310 MPa or more, or 320 MPa or more, or 330 MPa or more, or 340 MPa or more, while at the same time being 350 MPa or less, or 340 MPa or less, or 330 MPa or less, or 320 MPa or less, or 310 MPa or less, or 300 MPa or less, or 290 MPa or less, or 280 MPa or less, or 270 MPa or less, or 260 MPa or less, or 250 MPa or less, or 240 MPa or less, or 230 MPa or less, or 220 MPa or less, or 210 MPa or less. The flexural modulus is determined according to the procedure described in the Test Methods section below.

[0068] The polymer composition may have a melt flow rate of 1.0 g / min or more, or 1.1 g / min or more, or 1.2 g / min or more, or 1.3 g / min or more, or 1.4 g / min or more, or 1.5 g / min or more, or 1.6 g / min or more, or 1.7 g / min or more, or 1.8 g / min or more, or 1.9 g / min or more, 2.0 g / min or more, or 2.1 g / min or more, or 2.2 g / min or more, or 2.3 g / min or more, or 2.4 g / min or more, or 2.5 g / min or more, or 2.6 g / min or more, or 2.7 g / min or more, or 2.8 g / min or more, or 2.9 g / min or more, while simultaneously The MFI may be determined according to the procedure described in the Test Methods section below, for example, of 3.0 g / min or less, or 2.9 g / min or less, or 2.8 g / min or less, or 2.7 g / min or less, or 2.6 g / min or less, or 2.5 g / min or less, or 2.4 g / min or less, or 2.3 g / min or less, or 2.2 g / min or less, or 2.1 g / min or less, or 2.0 g / 10 min or less, or 1.9 g / min or less, or 1.8 g / min or less, or 1.7 g / min or less, or 1.6 g / min or less, or 1.5 g / min or less, or 1.4 g / min or less, or 1.3 g / min or less, or 1.2 g / min or less, or 1.1 g / min or less.

[0069] The polymer composition exhibits a hot knife indentation value of 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less, or 25% or less, or 20% or less, or 15% or less, or 10% or less, or 15% or less, or 10% or less, or 5% or less. The hot knife indentation value is measured at a thickness of 1.9 mm according to DIN EN 60811-3-1.

[0070] The polymeric composition exhibits an ESCR value of 1000 hours or more, or 1100 hours or more, or 1200 hours or more, or 1300 hours or more, or 1400 hours or more, or 1500 hours or more, or 1600 hours or more, or 1700 hours or more, or 1800 hours or more, or 1900 hours or more, or 2000 hours or more. ESCR values ​​are measured according to ASTM D1693. EXAMPLES

[0071] material The following materials are used in the following examples.

[0072] LLDPE is a linear low density polyethylene having a density of 0.92 g / cc and an MFI of 1 g / 10 min (190° C. / 21.6 kg), an example of which is commercially available as DOWLEX™ 2045G polyethylene resin from The Dow Chemical Company, Midland, MI, USA.

[0073] Polypropylene (PP) is a polypropylene homopolymer having a melt flow index of 12 g / 10 min (230° C., 2.16 kg) and a melting temperature of 160° C., an example of which is commercially available as PP H700-12 polypropylene from Braskem, Sao Paulo, Brazil.

[0074] POE is a polyolefin elastomer of ethylene and butylene having a melt flow index of 4.5 g / 10 min (190° C. / 21.6 kg), a density of 0.89 g / cc, and a melt temperature of 80° C., an example of which is commercially available under the trade name SEC 39001 from The Dow Chemical Company, Midland, MI, USA.

[0075] CBC is a crystalline block copolymer that is a polypropylene and polyethylene diblock composite. As used herein, polypropylene and polyethylene diblock composite is a composite of (i) CEP, a crystalline ethylene / propylene copolymer, (ii) CAOP, an isotactic crystalline propylene homopolymer (iPP), and (iii) a block copolymer containing an iPP block (CAOB) and an ethylene / propylene block (CEB), the properties of which are provided in Table 1 below.

[0076] [Table 1] · Wt% PP - The weight percentage of propylene polymers in the CBC as determined by high temperature liquid chromatography. Mw - weight average molecular weight of the CBC in kg / mol as determined by gel permeation chromatography as described above. · Mw / Mn - the molecular weight distribution of the CBC as determined by gel permeation chromatography as described above. · Total wt% C2-C13 The weight percentage of ethylene in the CBC as determined by nuclear magnetic resonance spectroscopy. Tm (°C) Peak 1 (Peak 2) - Peak melting temperature as determined by the second heating curve from DSC. Peak 1 refers to the melting of CEB / CEP (in case of CBC) or EB / EP (in case of BC), and Peak 2 refers to the melting of CEB or CEP. · Tc (℃) - Peak crystallization temperature as determined by DSC cooling scan.

[0077] Suitable processes useful for the production of CBC can be found, for example, in US Patent Application Publication No. 2008 / 0269412. In particular, the polymerization is desirably carried out as a continuous polymerization, preferably a continuous solution polymerization, in which the catalyst components, monomers, and optionally solvents, adjuvants, scavengers, and polymerization aids are continuously fed to one or more reactors or sections, from which polymer product is continuously removed. As used in this context, within the scope of the terms "continuous" and "continuously" are those processes in which there is intermittent addition of reactants and removal of products at regular or irregular small intervals, such that the overall process is substantially continuous over time. The chain shuttling agent can be added at any point during the polymerization, including at the outlet of the first reactor or section, or shortly before the outlet of the first reactor, or between the first reactor or section and the second or any subsequent reactor or section. Due to differences in monomers, temperature, pressure, or other differences in polymerization conditions between at least two of the series-connected reactors or compartments, polymer segments having different compositions, such as comonomer content, crystallinity, density, tacticity, regioregularity, or other chemical or physical differences within the same molecule, are formed in the different reactors or compartments. The size of each segment or block is determined by the sequential polymer reaction conditions, and is preferably the most probable polymer size distribution. Exemplary catalysts and catalyst precursors for use in forming crystalline block composites include metal complexes such as those disclosed in WO2005 / 090426.

[0078] MAH-g-HDPE is a malic anhydride grafted polyolefin elastomer having a density of 0.87 g / cc and a melt index of 1.25 g / 10 min, an example of which is commercially available under the trade name AMPLIFY™ GR 216 from The Dow Chemical Company, Midland, Mich., USA.

[0079] HFFR is magnesium hydroxide, an example of which is commercially available under the trade name MAGNIFIN™ H-5MV from Albemarle Corporation, Charlotte, NC, USA.

[0080] The stabilizer is a blend of 4 wt. % TiO2, 0.1 wt. % IRGASTAB™ FS301FF stabilizer, and 0.75 wt. % CHIMASSORB™ 2020 light stabilizing additive, the remainder being VERSIFY™ 2300 propylene-ethylene copolymer. IRGASTAB™ and CHIMASSORB™ are commercially available from BASF, Ludwigshafen, Germany, and VERSIFY™ 2300 is available from The Dow Chemical Company, Midland, MI, USA.

[0081] PA is a processing aid comprising an ultra-high molecular weight siloxane polymer commercially available as MB50-313™ masterbatch available from Dow Corning, Midland Michigan, USA.

[0082] Sample preparation The following steps are followed to prepare an Inventive Example ("IE") and a Comparative Example ("CE"): The materials for each of the IE and CE are loaded into a BUSS™ kneader, model MDK / E 46. The materials are mixed to homogenize the CE and IE samples. The IE and CE samples are compression molded to form 2 mm plaques for testing.

[0083] Test Method The following test methods are used to determine the characteristics of the compression molded plaques of the following IE and CE samples.

[0084] Tensile strength and elongation at break The samples are tested for tensile strength and elongation at break according to IEC 60811-512 on an INSTRON™ 4202 testing machine with a speed of 25 mm / min, a preload of 3 newtons (N), a yield sensitivity of 1%, a grip distance of 50 mm, and a 10,000 N load cell.

[0085] Flexural modulus Compression molded specimens are placed in the flex fixture of an INSTRON™ 4202 testing machine and a three-point deflection is performed using a span of 5.08 cm and a crosshead speed of 0.127 cm / min. Flexural modulus is determined according to ISO 178 at the maximum bending stress sustained during the test.

[0086] MFI The melt flow index of the samples is measured at 190° C. and 21.6 kg according to ASTM D1238.

[0087] Hot knife push The hot knife indentation value is determined according to DIN EN 60811-3-1 on a sample with a thickness of 1.9 mm.

[0088] ESCR The ESCR value of the sample is measured according to ASTM D1693.

[0089] result Table 2 provides composition data for CE1-CE4 in weight percent.

[0090] [Table 2]

[0091] Table 3 provides composition and mechanical property data for IE1 to IE4.

[0092] [Table 3]

[0093] CE1-CE4 are compositionally similar in that CE1-CE4 contain 1 wt.% or less of crystalline block composite. As is evident from the mechanical property data provided in Table 3, CE1-CE4 exhibit acceptable cable jacket properties in some properties, but do not provide an acceptable balance of properties in all mechanical property categories as IE1-IE4 do. For example, CE1, CE3, and CE4 meet the cable jacket properties of 10 MPa tensile strength and less than 50% hot knife indentation, but do not meet the 70% elongation at break or 1000 hours ESCR values. Similarly, CE2 nearly meets the 10 MPa tensile strength and has less than 50% hot knife indentation, but CE2 does not meet the 70% elongation at break or 1000 hours ESCR values.

[0094] IE1-IE4 are compositionally similar in that IE1-IE4 contain greater than 1 wt.% crystalline block composite. Specifically, IE1-IE4 each contain greater than 4 wt.% crystalline block composite and specifically propylene and polyethylene copolymer. As is evident from the mechanical property data provided in Table 3, IE1-IE4 exhibit acceptable cable jacket properties in all mechanical property categories. Thus, each of IE1-IE4 meets or exceeds the cable jacket properties of tensile strength of 10 MPa, elongation at break of 70%, hot knife indentation of less than 50%, and ESCR value of 1000 hours.

Claims

1. A polymer composition comprising, in weight percent of said polymer composition: (a) 10% to 30% by weight of a polyolefin elastomer; (b) 1% to 9% by weight of a propylene-based polymer; (c) 2% to 20% by weight of a crystalline block copolymer; (d) 1% to 10% by weight of a maleated polyolefin elastomer; (e) 40% to 80% by weight of a halogen-free flame retardant filler; the polyolefin elastomer is a random copolymer of ethylene and an α-olefin, the α-olefin having from 3 to 12 carbon atoms; the propylene-based polymer is a propylene homopolymer, A polymer composition, wherein the crystalline block copolymer is a diblock copolymer of polypropylene and polyethylene, and wherein component (a) does not include component (d).

2. 10. The polymer composition of claim 1, wherein said polymer composition comprises 50% to 70% by weight of said halogen-free, flame-retardant filler, said halogen-free, flame-retardant filler being magnesium hydroxide.

3. 10. The polymer composition of claim 1, wherein the maleated polyolefin elastomer is a maleic anhydride grafted polyolefin elastomer, and further wherein the polymer composition comprises from 3% to 7% by weight of the maleic anhydride grafted polyolefin elastomer.

4. The polymer composition comprises 15% to 25% by weight of the polyolefin elastomer, and further, the polyolefin elastomer has a modulus of elasticity of 0.87 g / cm when measured according to ASTM D792. ３ ~0.91 g / cm ３ 2. The polymer composition of claim 1 having a density in the range of

5. The polymer composition of claim 1, wherein the polymer composition comprises 4% to 8% by weight of a propylene-based polymer.

6. The polymer composition of claim 5, wherein said polymer composition comprises from 4% to 12% by weight of said crystalline block copolymer.

7. The polymer composition according to any one of claims 1 to 6, wherein the polyolefin elastomer is an ethylene and butylene polyolefin elastomer.

8. The polypropylene and polyethylene diblock copolymer has a modulus of 0.89 g / cm when measured according to ASTM D792. ３ ~0.92g / cm ３ The polymer composition according to any one of claims 1 to 6, having a density in the range of

9. 7. The polymer composition according to any one of claims 1 to 6, wherein the diblock copolymer of polypropylene and polyethylene has a melt flow index at 230°C and 2.16 kg of from 8 g / 10 min to 12 g / 10 min.

10. A cable, A conductor; and a polymer composition according to any one of claims 1 to 9 positioned around said conductor.

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