Radiation-curable polyolefin formulation

Abstract

An (electron beam) curable (EBC) formulation comprising an EBC polyolefin compound having a crystallinity of 0 to less than 50 weight percent (wt%) and / or a density of 0.930 grams per cubic centimeter (g / cm 3 ) or less; and an alkenyl-functional monocyclic organosiloxane (“silicon-based additive”). Also included is a cured polyolefin product prepared by electron beam irradiation of the EBC formulation; methods of making and using the EBC formulation or cured polyolefin product; and articles containing the EBC formulation or cured polyolefin product or made from the EBC formulation or cured polyolefin product.

Description

[0001] This application is a divisional application of a Chinese patent application with the application number 201880040976.8 (filing date: May 30, 2018, invention title: Radiation-curable polyolefin formulation). Technical Field

[0002] Polyolefin compositions, electron beam curing, methods, and articles.

[0003] Cross - Reference to Related Applications

[0004] This application claims the priority of PCT International Patent Application No. PCT / CN2017 / 090770 filed on June 29, 2017, and incorporates all of its content herein by reference. Background Art

[0005] Patent applications in this field include CN103865420A, CN104277182A, DE102006017346A1, EP1433811A2, EP2889323A1, US20020198335A1, and US20080176981A1. Patents in this field include US4005254, US5367030, US6187847B1, US6191230B1, US6936655B2, US8426519B2, US8449801B1, US8691984B2, and US9147784B2.

[0006] Electron beam radiation is applicable to methods for curing (crosslinking) polyolefins. The method includes applying a certain dose of electron beam radiation to an (electron beam)-curable (EBC) polyolefin compound to obtain a cured polyolefin product. The method directly forms covalent bonds between the polyolefin macromolecules of the EBC polyolefin compound. Electron beam curing methods can be used to cure various types of polyolefins, including low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE).

[0007] We introduce the following problems: (a) how to improve the thermal creep (thermal setting) performance of electron beam-cured polyethylene, (b) how to increase the electron beam radiation curing of (electron beam)-curable (EBC) polyolefin compounds, and (c) how to prepare a power cable containing an electron beam-cured insulating layer.

[0008] Crosslinked low density polyethylene (XLDPE) and crosslinked linear low density polyethylene (XLLDPE) are used in various industrial applications where they are exposed to higher operating temperatures, such as insulation for hot water pipes and power cables. For these applications, crosslinked polyethylene should have sufficient thermal creep (thermal set) properties (i.e., maintain its shape at the operating temperature). The thermal creep properties of (electron beam) crosslinked high density polyethylene are generally weaker than those of (electron beam) crosslinked linear low density polyethylene. Therefore, simply blending high density polyethylene into linear low density polyethylene and then subjecting the blend to electron beam curing is not expected to improve the thermal creep properties compared to electron beam curing linear low density polyethylene alone.

[0009] If the dose of electron beam radiation is too high, then undesirable side effects can occur. These include the generation of excessive heat, charge, and / or H2 gas. Overheating can lead to oxidation or degradation of the cured polyolefin product. Excessive H2 gas can lead to the formation of bubbles in the cured polyolefin product. Excessive charge can lead to discharge from the cured polyolefin product. If the dose applied is too low, then the compound may not cure sufficiently or reach a sufficient state of cure (degree of cure or crosslink density), and the properties of the incompletely cured polyolefin product may not be suitable for the intended purpose, such as protecting a cable. Summary of the Invention

[0010] We disclose technical solutions to one or more of the problems introduced below: (a) how to improve the thermal creep (thermal set) properties of electron beam cured polyethylene, (b) how to increase the electron beam radiation curing of (electron beam) cured (EBC) polyolefin compounds, and (c) how to prepare a power cable containing an electron beam cured insulation layer. The technical solutions include an (electron beam) cured (EBC) formulation that contains an EBC polyolefin compound (“matrix resin”) having a crystallinity of 0 to less than 50 weight percent (wt%) and / or a density of 0.930 grams per cubic centimeter (g / cm 3 ) or less; and a vinyl functional monocyclic organosiloxane (“silicon-based additive”). Embodiments also include cured polyolefin products (electron beam cured) prepared by electron beam irradiating the EBC formulation; methods of making and using the EBC formulation or cured polyolefin products; and articles containing or made from the EBC formulation or cured polyolefin products. The formulations and products of the present invention are suitable for any application that utilizes polyolefins (including crosslinked polyolefins), including coatings, films, sheets, and injection molded articles.

[0011] The severity of problems caused by excessive radiation doses can be attenuated by incorporating small amounts of silicon-based additives into an EBC polyolefin compound to obtain an EBC formulation. The EBC formulation can be cured in the absence of heat-induced free radical-generating compounds such as organic peroxides. The EBC formulation can be cured at a lower dose compared to the electron beam radiation dose used to cure the EBC polyolefin compound without the silicon-based additive. Additionally, with the aid of additional crosslinking from the polyvalent crosslinking groups derived from the silicon-based additive, the resulting cured polyolefin product can achieve the same or greater state of cure compared to the state of cure of a comparative cured polyolefin product prepared at the same low EB dose and without the silicon-based additive. All other conditions being equal, the higher the loading of the silicon-based additive in the EBC formulation, the lower the dose of electron beam radiation that can be used to achieve a given state of cure (degree or density of crosslinking). Detailed Description

[0012] The Summary of the Invention and the Abstract are incorporated herein by reference. Examples of embodiments include the following numbered aspects.

[0013] Aspect 1. An (electron beam) curable (EBC) formulation comprising components (A) and (B): (A) an (electron beam) curable (EBC) polyolefin compound (“host resin”) having a crystallinity of 0 to less than 50 weight percent (wt%) as measured by a crystallinity test method using differential scanning calorimetry (DSC), or 10 to less than 50 wt%, and / or a density of 0.930 grams per cubic centimeter (g / cm 3 ) or less as measured by ASTM D792-13 Method B, or 0.925 g / cm 3 or less; and (B) a vinyl-functionalized monocyclic organosiloxane having the formula (I): [R 1 ,R 2 SiO 2 / 2 n (I), wherein the subscript n is an integer greater than or equal to 3; each R 1 is independently a (C2-C4) alkenyl or H2C═C(R 1a )-C(═O)-O-(CH2) m- , wherein R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, a (C1-C4) alkyl, phenyl, or R 1 ​("Silicon-based additive"); wherein (A) is 50.0 to 99.99 weight percent (wt%) of the combined weight of components (A) and (B), or 80.0 to 99.99 weight%, or 90 to 99.9 weight%, or 95.0 to 99.4 weight%, and (B) is 50.0 weight% to 0.01 weight% of the combined weight of components (A) and (B), or 20.0 weight% to 0.01 weight%, or 10 weight% to 0.1 weight%, or 5.0 weight% to 0.6 weight%; and provided that the EBC formulation does not contain each of phosphazene base, semi-crystalline polyolefin having a crystallinity of 50 weight% or greater, and organic peroxide. The amount of (B) in the EBC formulation effectively enables the (A) EBC polyolefin compound of the EBC formulation to be electron beam cured at a lower radiation dose as compared to the case where (B) is absent. Except for the aforementioned excluded materials (phosphazene base, semi-crystalline polyolefin having a crystallinity of 50 weight% or greater, and organic peroxide), the components of the EBC formulation are not particularly limited. Certain embodiments are described later as optionally not containing one or more additional materials.

[0014] Aspect 2. The EBC formulation according to aspect 1, wherein the (A) EBC polyolefin compound is characterized by any one of (i) to (xv): (i) measured by a crystallinity test method using differential scanning calorimetry (DSC), having a crystallinity > 0 to less than 50.0 weight percent (wt%), or 10 to 45 weight%, or 15 to 40 weight%, or 20 to 35 weight%; (ii) measured by ASTM D792-13 method B, having a density of 0.930 g / cm 3 or less, or 0.860 to 0.929 g / cm 3 or 0.880 to 0.929 g / cm 3 or 0.900 to 0.929 g / cm 3 or 0.910 to 0.929 g / cm 3; (iii) both (i) and (ii); (iv) the melt index is from 0.1 to 20 grams per 10 minutes (g / 10min), or 0.2 to 20 g / 10min, or 0.5 to 10 g / 10min (I2, 190 °C / 2.16 kg load), all measured according to the melt index test method (described later), and is polyethylene; (v) the melt flow rate (MFR) is from 0.5 to 20 g / 10min (230 °C / 2.16 kg load) measured according to the melt flow rate test method (described later), and is polypropylene; (vi) the molecular weight distribution (MWD) is unimodal; (vii) the MWD is multimodal or bimodal; (viii) the combined weight of components (A) and (B) is 50 to 100% by weight, or 70 to 100% by weight, or 80 to 100% by weight, or 90 to 100% by weight, or 50 to 99.9% by weight, or 70 to 99.9% by weight, or 80 to 99.9% by weight, or 90 to 99.9% by weight of the EBC formulation; (ix) (A) the EBC polyolefin compound is a low-density polyethylene (LDPE) with a density of 0.910 to 0.925 g / cm 3 ; (x) (A) the EBC polyolefin compound is a linear low-density polyethylene (LLDPE) with a density of 0.910 to 0.925 g / cm 3 ; (xi) (A) the EBC polyolefin compound is a polyethylene elastomer selected from elastomers based on ethylene copolymers such as ethylene-propylene rubber (EPR), ethylene-1-butene rubber (EBR), and ethylene-1-octene rubber (EOR); (xii) (A) the EBC polyolefin compound is an ethylene / (C3-C 20 ) α-olefin copolymer; (xiii) (A) the EBC polyolefin compound is an ethylene-propylene copolymer (EPP); (xiv) (A) the EBC polyolefin compound is an ethylene-propylene-diene monomer (EPDM) copolymer; and (xv) (A) the EBC polyolefin compound is a combination of any two or more of (i) to (xiv).

[0015] Aspect 3. The EBC formulation according to Aspect 1 or 2, wherein in (B) the alkenyl-functional monocyclic organosiloxane of formula (I), the subscript n is 3, and wherein the EBC formulation is described by any one of the limitations (i) to (x): (i) each R 1 is independently a (C2-C3) alkenyl; and each R 2 is independently H, (C1-C2) alkyl, or (C2-C3) alkenyl; (ii) each R 1 is vinyl; and each R 2is independently a (C1-C2) alkyl group; (iii) each R 1 is vinyl; and each R 2 is methyl; (iv) each R 1 is allyl; and each R 2 is independently a (C1-C2) alkyl group; (v) each R 1 is allyl; and each R 2 is methyl; (vi) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, a (C1-C2) alkyl group or a (C2-C3) alkenyl group; (vii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H and the subscript m is 3; and each R 2 is independently a (C1-C2) alkyl group; (viii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is methyl and the subscript m is 3; and each R 2 is independently a (C1-C2) alkyl group; (ix) the EBC formulation does not contain 24 wt% or more, or does not contain 22 wt% or more, or does not contain 20.0 wt% or more, or does not contain 15 wt% or more, or does not contain 10 wt% or more of an inorganic filler or does not contain an inorganic filler, the inorganic filler being selected from the group consisting of: alumina, aluminum silicate, calcium silicate, magnesium silicate, silica, titanium dioxide and mixtures thereof; and (x) a combination of limitation (ix) with any one of limitations (i) to (viii).

[0016] Aspect 4. The EBC formulation according to aspect 1 or 2, wherein in the (B) alkenyl-functional monocyclic organosiloxane of formula (I), the subscript n is 4, and wherein the EBC formulation is described by any one of (i) to (x): (i) each R 1 is independently a (C2-C3) alkenyl group; and each R 2 is independently H, a (C1-C2) alkyl group or a (C2-C3) alkenyl group; (ii) each R 1 is vinyl; and each R 2 is independently a (C1-C2) alkyl group; (iii) each R 1is vinyl; and each R 2 is methyl; (iv) each R 1 is allyl; and each R 2 is independently (C1-C2) alkyl; (v) each R 1 is allyl; and each R 2 is methyl; (vi) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (vii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (viii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is methyl and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (ix) the EBC formulation contains no 24 wt% or more (i.e., contains from 0 to <24 wt%), or no 22 wt% or more, or no 20.0 wt% or more, or no 15 wt% or more, or no 10 wt% or more of an inorganic filler, or no inorganic filler; and (x) a combination of limitation (ix) with any one of limitations (i) to (viii).

[0017] Aspect 5. The EBC formulation according to aspect 1 or 2, wherein in the (B) alkenyl-functional monocyclic organosiloxane of formula (I), the subscript n is 5 or 6, and wherein the EBC formulation is described by any one of limitations (i) to (x): (i) each R 1 is independently (C2-C3) alkenyl; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (ii) each R 1 is vinyl; and each R 2 is independently (C1-C2) alkyl; (iii) each R 1 is vinyl; and each R 2 is methyl; (iv) each R 1 is allyl; and each R2 is independently a (C1-C2) alkyl group; (v) each R 1 is allyl; and each R 2 is methyl; (vi) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (vii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (viii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is methyl and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (ix) the EBC formulation does not contain 24 wt% or more, or does not contain 22 wt% or more, or does not contain 20.0 wt% or more, or does not contain 15 wt% or more, or does not contain 10 wt% or more of an inorganic filler or does not contain an inorganic filler, the inorganic filler being selected from the group consisting of: alumina, aluminum silicate, calcium silicate, magnesium silicate, silica, titanium dioxide, and mixtures thereof; and (x) a combination of limitation (ix) with any one of limitations (i) to (viii).

[0018] Aspect 6. The EBC formulation according to any one of Aspects 1 to 5, further comprising at least one additive independently selected from optional components (additives) (C) to (O): (C) carbon-based aids; (D) flame retardants; (E) antioxidants; (F) processing aids; (G) colorants (such as carbon black); (H) metal deactivators; (I) hydrolyzable silanes free of (unsaturated carbon-carbon bonds); (J) corrosion inhibitors; (K) hindered amine light stabilizers; (L) ethylene-based copolymers that are different from component (A) and different from the semi-crystalline polyolefin having a crystallinity of 50 wt% or greater, where (L) is ethylene / (C4-C 20α-olefin copolymer, ethylene / unsaturated carboxylate copolymer, or propylene / ethylene-based copolymer; (M) filler; (N) nucleating agent; and (O) anti-treeing agent, such as anti-water-treeing agent or anti-electrical-treeing agent (i.e., voltage stabilizer). When the EBC formulation contains one or more optional additives, the total amount of the optional additives is >0 to 70 wt% of the EBC formulation, or >0 to 60 wt%, or >0 to 40 wt%, or >0 to 20 wt%. The (M) filler does not include any omitted fillers. In some aspects, the polyolefin composition further comprises any two of (C) to (O). In some aspects, the polyolefin composition further comprises (E) antioxidant; or (E) antioxidant and (H) hindered amine stabilizer.

[0019] Aspect 7. A method of making an (electron beam) curable formulation according to any one of Aspects 1 to 6, the method comprising mixing (A) a separated solid form or a molten form of an EBC polyolefin compound with (B) an alkenyl-functional monocyclic organosiloxane of formula (I) and any optional components (C) to (O), or (D) to (O), so as to obtain a mixture consisting essentially of components (A), (B) and any optional components (C) to (O), or (D) to (O), thereby preparing an (electron beam) curable (EBC) formulation; provided that the method is free of each of phosphazene base, semi-crystalline polyolefin having a crystallinity of 50 wt% or greater, and organic peroxide. The mixing may comprise melt-mixing, soaking or directly injecting (B) into (A). The melt-mixing may comprise compounding, extrusion or kneading, and may be carried out using a Farrel Continuous Mixer (FCM), a tween extruder, a buss kneader or a similar device. Alternatively, the alkenyl-functional monocyclic organosiloxane of formula (I) of (B) may be soaked into the EBC polyolefin compound (e.g., pellets) of (A) alone or together with one or more other soakable liquid additives to obtain an EBC formulation. Alternatively, (B) may be directly injected into (A) during profile extrusion or molding of (A). The resulting EBC formulation may be irradiated with electron beam radiation to obtain a cured polyolefin product. The extruded EBC formulation may be granulated to obtain an EBC formulation in the form of solid pellets. Alternatively, the extruded EBC formulation may be cooled to obtain an EBC formulation in the form of a shaped solid, such as an insulating layer on a cable.

[0020] Aspect 8. A method for electron beam curing a formulation in need thereof, the method comprising irradiating an EBC formulation according to any one of aspects 1 to 6 or an (electron beam) cured formulation obtained by the method according to aspect 7 with an effective dose of electron beam radiation so as to obtain an electron beam cured polyolefin product. The EBC formulation in the form of a shaped solid can be cured by the method to obtain an electron beam cured polyolefin product in a shaped form. Alternatively, the EBC formulation cures when in a discrete solid form such as powder, granules, pellets, or any combination of two or more thereof.

[0021] Aspect 9. An electron beam cured polyolefin product obtained by the method according to aspect 8. The product can have a defined shape, such as a coating, film, or molded or extruded shape.

[0022] Aspect 10. An article comprising an electron beam cured polyolefin product according to aspect 9 and a component in operative contact therewith. The component is made of a material other than the electron beam cured polyolefin product or the EBC formulation. The component can be a substrate for supporting the EBC polyolefin product.

[0023] Aspect 11. A coated conductor comprising a conductive core and a polymeric layer at least partially surrounding the conductive core, wherein at least a portion of the polymeric layer comprises an electron beam cured polyolefin product according to aspect 9. The coated conductor can be an insulated electrical conductor (power cable), and the polymeric layer can be an insulating layer of the coated conductor. Insulated electrical conductors typically comprise a conductive core covered by an insulating layer. The conductive core can be solid or stranded (e.g., a bundle of wires). Some insulated electrical conductors can also contain one or more additional elements, such as one or more semiconductor layers and / or protective sheaths (e.g., wraps, tapes, or jackets). Examples are coated metal wires and power cables, including those for low voltage (“LV”, >0 to <5 kilovolts (kV)), medium voltage (“MV”, 5 to <69 kV), high voltage (“HV”, 69 to 230 kV), and extra high voltage (“EHV”, >230 kV) power transmission / distribution applications. Power cables can be evaluated using AEIC / ICEA standards and / or IEC test methods. During operation in the field, power cables are exposed to the detrimental effects of ultraviolet light (e.g., from the sun) and are heated to 90 °C or higher temperatures (e.g., generated within the cable).

[0024] Aspect 12. A method of conducting electricity, the method comprising applying a voltage across the conductive core of a coated conductor according to aspect 11 so as to generate an electric current through the conductive core.

[0025] The present invention also relates to the following specific embodiments:

[0026] 1. An (electron beam)-curable (EBC) formulation comprising components (A) and (B):

[0027] (A) An (electron beam)-curable (EBC) polyolefin compound having a crystallinity of 0 to less than 50 weight percent (wt%) as measured by a crystallinity test method using differential scanning calorimetry (DSC), and / or having a density of 0.930 grams per cubic centimeter (g / cm 3 ) or less as measured by ASTM D792-13 Method B; and

[0028] (B) An alkenyl-functional monocyclic organosiloxane having the formula (I): [R 1 ,R 2 SiO 2 / 2 n (I) wherein the subscript n is an integer greater than or equal to 3; each R 1 is independently a (C2-C4) alkenyl or H2C=C(R 1a )-

[0029] C(=O)-O-(CH2) m- , wherein R 1a is H or methyl and the subscript m is an integer from 1 to 4; and

[0030] each R 2 is independently H, a (C1-C4) alkyl, phenyl or R 1 ;

[0031] wherein (A) is 50.0 to 99.99 weight percent, and (B) is 50.0 to 0.01 weight percent of the combined weight of components (A) and (B); and

[0032] provided that the EBC formulation does not contain each of a phosphazene base, a semi-crystalline polyolefin having a crystallinity of 50 weight percent or greater, and an organic peroxide.

[0033] 2. The (electron beam)-curable formulation according to item 1, wherein the (A) EBC polyolefin compound is characterized by any one of limitations (i) to (xv): (i) having a crystallinity > 0 to less than 50.0 weight percent as measured by a crystallinity test method using differential scanning calorimetry (DSC); (ii) having a density of 0.930 g / cm 3 ​or less; (iii) both (i) and (ii); (iv) having a melt index (I2, 190 °C / 2.16 kg load) of 0.1 to 20 grams per 10 minutes (g / 10min) as measured according to the melt index test method, and being polyethylene; (v) having a melt flow rate (MFR) of 0.5 to 20 g / 10min (230 °C / 2.16 kg load) as measured according to the melt flow rate test method, and being polypropylene; (vi) having a unimodal molecular weight distribution (MWD); (vii) having a multimodal MWD; (viii) wherein the combined weight of components (A) and (B) is 50 to 100 weight percent of the (electron beam) curable formulation; (ix) the (A) EBC polyolefin compound is a low density polyethylene (LDPE) having a density of 0.910 to 0.925 g / cm 3 ; (x) the (A) EBC polyolefin compound is a linear low density polyethylene (LLDPE) having a density of 0.910 to 0.925 g / cm 3 ; (xi) the (A) EBC polyolefin compound is a polyethylene elastomer selected from ethylene - propylene rubber (EPR), ethylene - 1 - butene rubber (EBR), and ethylene - 1 - octene rubber (EOR); (xii) the (A) EBC polyolefin compound is an ethylene / (C3 - C 20 ) α - olefin copolymer; (xiii) the (A) EBC polyolefin compound is an ethylene - propylene copolymer (EPP); (xiv) the (A) EBC polyolefin compound is an ethylene - propylene - diene monomer (EPDM) copolymer; and (xv) the (A) EBC polyolefin compound is a combination of any two or more of (i) to (xiv).

[0034] 3. The (electron beam) curable formulation according to item 1 or 2, wherein in the (B) alkenyl - functional monocyclic organosiloxane of formula (I), the subscript n is 3, and wherein the EBC formulation is described by any one of (i) to (x): (i) each R 1 is independently a (C2 - C3) alkenyl; and each R 2 is independently H, a (C1 - C2) alkyl, or a (C2 - C3) alkenyl; (ii) each R 1 is vinyl; and each R 2 is independently a (C1 - C2) alkyl; (iii) each R 1 is vinyl; and each R 2 is methyl; (iv) each R 1 is allyl; and each R 2 is independently a (C1 - C2) alkyl; (v) each R1 is allyl; and each R 2 is methyl; (vi) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (vii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (viii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is methyl and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (ix) the EBC formulation does not contain 24 wt% or more of inorganic fillers selected from the group consisting of: alumina, aluminum silicate, calcium silicate, magnesium silicate, silica, titanium dioxide, and mixtures thereof; and (x) a combination of limitation (ix) with any one of limitations (i) to (viii).

[0035] 4. The (electron beam) curable formulation according to item 1 or 2, wherein in the (B) alkenyl-functional monocyclic organosiloxane of formula (I), the subscript n is 4, and wherein the EBC formulation is described by any one of limitations (i) to (x): (i) each R 1 is independently (C2-C3) alkenyl; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (ii) each R 1 is vinyl; and each R 2 is independently (C1-C2) alkyl; (iii) each R 1 is vinyl; and each R 2 is methyl; (iv) each R 1 is allyl; and each R 2 is independently (C1-C2) alkyl; (v) each R 1 is allyl; and each R 2 is methyl; (vi) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2)m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (vii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (viii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is methyl and the subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (ix) the EBC formulation does not contain 24 wt% or more of any inorganic filler; and (x) a combination of limitation (ix) and any one of limitations (i) to (viii).

[0036] 5. The (electron beam) curable formulation according to item 1 or 2, wherein in the (B) vinyl-functional monocyclic organosiloxane of formula (I), the subscript n is 5 or 6, and wherein the EBC formulation is described by any one of limitations (i) to (x): (i) each R 1 is independently (C2-C3) alkenyl; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (ii) each R 1 is vinyl; and each R 2 is independently (C1-C2) alkyl; (iii) each R 1 is vinyl; and each R 2 is methyl; (iv) each R 1 is allyl; and each R 2 is independently (C1-C2) alkyl; (v) each R 1 is allyl; and each R 2 is methyl; (vi) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, (C1-C2) alkyl or (C2-C3) alkenyl; (vii) each R 1 is independently H2C=C(R 1a)-C(=O)-O-(CH2) m- , wherein R 1a is H and subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (viii) each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , wherein R 1a is methyl and subscript m is 3; and each R 2 is independently (C1-C2) alkyl; (ix) the EBC formulation does not contain 24 wt% or more of inorganic fillers selected from the group consisting of alumina, aluminum silicate, calcium silicate, magnesium silicate, silica, titanium dioxide, and mixtures thereof; and (x) the combination of limitation (ix) with any one of limitations (i) to (viii).

[0037] 6. The (electron beam) curable formulation according to any one of items 1 to 5, further comprising at least one additive independently selected from optional components (C) to (O): (C) carbon-based aids; (D) flame retardants; (E) antioxidants; (F) processing aids; (G) colorants (such as carbon black); (H) metal deactivators; (I) hydrolyzable silanes without (unsaturated carbon-carbon bonds); (J) corrosion inhibitors; (K) hindered amine light stabilizers; (L) ethylene-based copolymers different from component (A) and different from the semi-crystalline polyolefin having a crystallinity of 50 wt% or greater, wherein (L) is an ethylene / (C4-C 20 ) α-olefin copolymer, an ethylene / unsaturated carboxylate copolymer, or a propylene / ethylene-based copolymer; (M) fillers; (N) nucleating agents; and (O) anti-treeing agents.

[0038] 7. A method of making the (electron beam) curable formulation according to any one of items 1 to 6, the method comprising mixing the separated solid form or molten form of the (A) EBC polyolefin compound with the (B) alkenyl-functional monocyclic organosiloxane of formula (I) and any optional components (C) to (O) together to obtain a mixture consisting essentially of components (A), (B), and any optional components (C) to (O), thereby making the (electron beam) curable (EBC) formulation; provided that the method does not contain each of phosphazene bases, semi-crystalline polyolefins having a crystallinity of 50 wt% or greater, and organic peroxides.

[0039] 8. A method of electron beam curing a formulation in need thereof, the method comprising irradiating the EBC formulation according to any one of items 1 to 6 or the (electron beam) curable formulation made by the method according to item 7 with an effective dose of electron beam radiation to obtain an electron beam cured polyolefin product.

[0040] 9. An electron beam cured polyolefin product made by the method according to item 8.

[0041] 10. An article comprising the electron beam cured polyolefin product according to item 9 and components in operative contact therewith.

[0042] 11. A coated conductor comprising a conductive core and a polymeric layer at least partially surrounding the conductive core, wherein at least a portion of the polymeric layer comprises the electron beam cured polyolefin product according to item 9.

[0043] 12. A method of conducting electricity, the method comprising applying a voltage across the conductive core of the coated conductor according to item 11 to produce a current through the conductive core.

[0044] The EBC formulation of the present invention can be cured (crosslinked) via electron beam radiation without ring-opening of (B) alkenyl-functional monocyclic organosiloxanes. The curing reaction is carried out in such a way that (B) alkenyl-functional monocyclic organosiloxanes do not produce polysiloxanes (silicone polymers) or sesquisiloxanes. We believe that (B) alkenyl-functional monocyclic organosiloxanes act as co-agents (crosslinking agents) during the electron beam curing of the EBC formulation, and the resulting cured polyolefin product has both direct polyolefin-polyolefin bonds and polyolefins crosslinked via polyvalent crosslinking groups derived from (B) alkenyl-functional monocyclic organosiloxanes. Without being bound by theory, it is believed that the components of the EBC formulation are selected such that during the electron beam curing of the EBC formulation, (B) alkenyl-functional monocyclic organosiloxanes do not ring-open, resulting in ring-opened silanol (S-OH)-functional organosiloxane oligomers (linear or branched), and thus polysiloxanes (silicone polymers) or sesquisiloxanes are not formed in situ. Without being bound by theory, since the EBC formulation does not contain (b) a ring-opening catalyst as a phosphazene base, and thus since the curing reaction proceeds in the absence of said ring-opening catalyst, it is believed that (B) alkenyl-functional monocyclic organosiloxanes are at least partially unable to ring-open. In the absence of phosphazene base, the EBC formulation crosslinks (B) alkenyl-functional monocyclic organosiloxanes with polyolefin polymers via free radical curing to form a cured polyolefin product. Crosslinking advantageously occurs without ring-opening of (B) alkenyl-functional monocyclic organosiloxanes even in the presence of ambient moisture.

[0045] Additive: A solid or liquid compound or substance that imparts desired properties to a host polymer or to a formulation comprising a matrix mixture and a host polymer or to a reaction product prepared therefrom. The properties can be chemical, electrical, mechanical, optical, physical, and / or thermal properties.

[0046] α-olefin: A compound of formula (I): H2C═C(H)-R (I), where R is a straight-chain alkyl group.

[0047] The crystallinity of semi-crystalline polyolefins can be determined by differential scanning calorimetry (DSC) according to ASTM D3418-15 or by a crystallinity test method using DSC described later. For semi-crystalline polyethylene resin, % crystallinity by weight = (ΔH f * 100%) / 292 J / g. For semi-crystalline polypropylene resin, % crystallinity by weight = (ΔH f * 100%) / 165 J / g. In each equation, ΔH f is the heat of fusion of the second heating curve of the polyethylene resin or polypropylene resin, as the case may be, * indicates mathematical multiplication, / indicates mathematical division, 292 J / g is the literature value of the heat of fusion (ΔH f ) of 100% crystalline polyethylene, and 165 J / g is the literature value of the heat of fusion (ΔH f ) of 100% crystalline polypropylene. Preferably, the crystallinity is determined by DSC according to the crystallinity test method described later.

[0048] Curing agent: A compound that generates free radicals (in situ), which forms free radicals upon activation and initiates or enhances reactions involving crosslinking of macromolecules. Activation of the curing agent can be achieved by subjecting the curing agent to heat or light. Examples of curing agents are peroxides, diazo-functional organic compounds, and 2,3-dimethyl-2,3-diphenylbutane. Examples of peroxides are organic hydroperoxides of the formula H-O-O-R and organic peroxides of the formula R-O-O-R, where each R is independently a hydrocarbon group. In some aspects, the EBC formulation and the cured polyolefin product prepared therefrom do not contain curing agents such as peroxides (such as organic hydroperoxides or organic peroxides).

[0049] Curing: Crosslinking to form a crosslinked product (network polymer).

[0050] Day: Any continuous 24-hour period.

[0051] Isolated solid: A particulate material in the solid state of matter, characterized by a relatively stable shape and volume. Examples are powders, fines, and pellets.

[0052] Effective dose: The amount absorbed (absorbed dose) that is sufficient to cause crosslinking of the polyolefin in need and is absorbed in that amount.

[0053] Electron beam curing: Capable of being cured by irradiation (treatment) with high-energy β radiation (e.g., from a high-energy electron beam accelerator). The radiation induces covalent bonding (crosslinking) between adjacent macromolecules, forming a network polymer.

[0054] High-Density Polyethylene (HDPE): having a density of 0.941 to 0.990 g / cm 3 , having an α-olefin comonomer unit content greater than 0 wt% and having short chain branches.

[0055] Linear Low-Density Polyethylene (LLDPE): having a density of 0.910 to 0.925 g / cm3, having an α-olefin comonomer unit content greater than 0 wt% and having short chain branches. The comonomer distribution breadth index (CDBI) of the LLDPE can be from 70 to less than 100 weight percent.

[0056] Low-Density Polyethylene (LDPE): a polyethylene homopolymer having a density of 0.910 to 0.925 g / cm3 (comonomer unit content 0 wt%, CDBI = 100%, no short chain branches). LDPE can be produced via a free radical polymerization mechanism in a high-pressure polymerization process without a catalyst.

[0057] Medium-Density Polyethylene (MDPE): having a density of 0.926 to 0.940 g / cm 3 .

[0058] Machine-made article: an artificial (by hand or machine) object.

[0059] Melt: a liquid formed by heating a solid material above its highest melting temperature.

[0060] Polyolefin: a macromolecule or collection of macromolecules composed of structural units derived from polymerizable olefins.

[0061] Semicrystalline: a solid material having a first region that is crystalline and a second region that is amorphous. Measured by the crystallinity test method described later, the crystallinity percentage is typically between 5% and 90%.

[0062] Formed solid: a state of matter having a relatively constant volume and external form, which is artificial (by hand or machine). For example, a fluid is extruded, molded, or coated into an external form, and then the external form is appropriately cooled to produce a formed solid.

[0063] Storage: to hold or maintain.

[0064] Sweating: the slow release of an additive from a solid material containing the additive.

[0065] Component (A) Electron Beam Curing (EBC) polyolefin compound (“host polymer”). The (A) EBC polyolefin compound can be low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polyolefin elastomer, ethylene / (C3-C 40 ) α-olefin copolymer or any combination of two or more thereof (e.g., blend or melt mixture). The density of LDPE can be from 0.910 to 0.925 g / cm 3 . The density of LLDPE can be from 0.910 to 0.925 g / cm 3 . The polyolefin elastomer based on ethylene copolymer can be selected from EPR and EBR, or EPR and EOR, or EBR and EOR, or EPR, or EBR, or EOR. Examples of such elastomers are ENGAGE TM , AFFINITY TM and INFUSE TM polyolefin elastomers available from Dow Chemical Company. The ethylene / (C3-C 20 ) α-olefin copolymer can be the ethylene / propylene copolymer or ethylene / (C4-C 20 ) α-olefin copolymer described herein. The ethylene-propylene copolymer (EPP) can be a dimer or an ethylene-propylene-diene monomer (EPDM) copolymer. The (A) EBC polyolefin compound can differ from the excluded semi-crystalline polyolefins and (L) ethylene-based polymer additives in at least one of the following characteristics: monomer composition, comonomer composition, density, crystallinity, melt index, melt flow rate, number average molecular weight (M n ), weight average molecular weight (M w ), molecular weight distribution (M w / M n ) and porosity.

[0066] Before the mixing step for preparing the EBC formulation, the (A) EBC polyolefin compound can be in a separate solid form such as powder, granule and / or pellet.

[0067] Component (B) Alkenyl-functionalized monocyclic organosiloxane (silicon-based additive). A molecule containing a main chain or cyclic substructure containing silicon and oxygen atoms and two or more propenyl, acrylate and / or vinyl groups bonded thereto, or a collection of such molecules.

[0068] Component (B) is as defined previously and is used in the EBC formulation in a crosslinking-effective amount. Based on the total weight of the EBC formulation, the crosslinking-effective amount of (B) can be from 0.01 wt% to 50 wt%, or from 0.1 wt% to 25 wt%, or from 0.5 wt% to 10 wt%, or from 0.9 wt% to 5 wt%, or from 1 wt% to 4 wt%. The crosslinking-effective amount of (B) in the EBC formulation can vary depending on the circumstances described above. For example, the crosslinking-effective amount of (B) can be higher in an embodiment of a polyolefin composition containing (d) inorganic filler compared to an embodiment of a polyolefin composition without (d) inorganic filler.

[0069] Regarding the determination of the crosslinking-effective amount of component (B), the presence of crosslinking can be detected by the solvent extraction percentage (Ext%). Ext% = W1 / Wo * 100%, where W1 is the weight after extraction and Wo is the original weight before extraction, / indicates division, and * indicates multiplication. By carbon-13 or silicon-29 nuclear magnetic resonance ( 13 C-NMR spectroscopy and / or 29 Si-NMR) spectroscopy, the absence or reduced level of the unsaturated organic groups of (B) (e.g., R 1 ) due to coupling with the (A) EBC polyolefin compound can be detected in the crosslinked polyolefin product.

[0070] Optional component (C) Carbon-based promoter. The (C) carbon-based promoter comprises a substructural group bonded to two or more olefin crosslinking groups, wherein the substructural group is an acyclic or cyclic polyvalent group, which respectively includes a main chain or a ring, contains in the main chain or ring carbon atoms, and optionally, nitrogen and / or oxygen atoms, but does not contain silicon atoms. Examples are 2-allylphenyl allyl ether; 4-isopropenyl-2,6-dimethylphenyl allyl ether; 2,6-dimethyl-4-allylphenyl allyl ether; 2-methoxy-4-allylphenyl allyl ether; 2,2'-diallylbisphenol A; O,O'-diallylbisphenol A; or tetramethyldiallylbisphenol A; 2,4-diphenyl-4-methyl-1-pentene; 1,3-diisopropenylbenzene; triallyl isocyanurate; triallyl cyanurate; triallyl trimellitate; N,N,N′,N′,N″,N″-hexaallyl-1,3,5-triazine-2,4,6-triamine; triallyl orthoformate; pentaerythritol triallyl ether; triallyl citrate; triallyl aconitate; trimethylolpropane triallyl ether; ethoxylated bisphenol A dimethacrylate; 1,6-hexanediol diacrylate; pentaerythritol tetraacrylate; dipentaerythritol pentaacrylate; tri(2-hydroxyethyl) isocyanurate triacrylate; propoxylated glycerol triallyl ether; polybutadiene having at least 50 wt% 1,2-vinyl content; trivinylcyclohexane; and mixtures of any two or more thereof. In some aspects, (C) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (C) is present in the inventive parent mixture, formulation, and / or product at a concentration of 0.1 wt% to 10 wt%, or 1 wt% to 5 wt%, and or 2 wt% to 5 wt%; all based on its total weight.

[0071] Optional component (additive) (D) Flame retardant. The (D) flame retardant is a compound that inhibits or retards the spread of fire by suppressing chemical reactions in the flame. In some aspects, the (D) flame retardant is (D1) a mineral, (D2) an organic halogen compound, (D3) an (organic) phosphorus compound; (D4) a halogenated silicone; or (D5) a combination of any two or more of (D1) to (D4). In some aspects, (D) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (D) is present in the inventive parent mixture, formulation, and / or product at a concentration of 0.1 wt% to 20 wt%, or 1 wt% to 10 wt%, and or 5 wt% to 20 wt%; all based on its total weight.

[0072] Optional component (additive) (E) Antioxidant. A compound used to inhibit the oxidation of polyolefins. Examples of suitable secondary antioxidants are polymeric 1,2-dihydro-2,2,4-trimethylquinoline (Agerite MA); tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione (Cyanox 1790); distearyl-3,3'-thiodipropionate (DSTDP); tetramethylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) methane (Irganox 1010); 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazine (Irganox 1024); bis(4,6-dimethylphenyl) isobutylene (Lowinox 22IB46); and 4,4'-thiobis(2-tert-butyl-5-methylphenol) (TBM6). In some aspects, (E) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (E) is present in the inventive parent mixture, formulation, and / or product at a concentration of 0.01 wt% to 10 wt%, or 0.05 wt% to 5 wt%, or 0.1 wt% to 3 wt% based on the total weight of the inventive parent mixture, formulation, and / or product.

[0073] Optional component (additive) (F) Processing aid. Component (F) can improve the melt flowability of the aid parent mixture by a machine. (F) can be an organic processing aid, such as a fluoropolymer or a silicone processing aid, such as a polyorganosiloxane or a fluorofunctionalized polyorganosiloxane. In some aspects, (F) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (F) is present in the inventive parent mixture, formulation, and / or product at a concentration of 1 to 20 wt%, or 2 to 18 wt%, or 3 to 15 wt% based on the total weight of the inventive parent mixture, formulation, and / or product.

[0074] Optional component (additive) (G) Colorant. For example, a pigment or a dye. For example, carbon black or titanium dioxide. Carbon black can be provided in the form of a carbon black parent mixture, which is a formulation of poly(1-butene-co-ethylene) copolymer (≥95 wt% to <100 wt% of the total weight of the parent mixture) and carbon black (>0 wt% to ≤5 wt% of the total weight of the carbon black parent mixture). In some aspects, (G) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, the colorant (G) is present in the inventive parent mixture, formulation, and / or product at a concentration of 0.1 to 35 wt%, or 1 to 10 wt% based on the total weight of the inventive parent mixture, formulation, and / or product.

[0075] Optional component (additive) (H) Metal deactivator. For example, oxalyl bis(benzylhydrazide) (OABH). In some aspects, (H) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (H) is present in the inventive parent mixture, formulation, and / or product in an amount of 0.001 to 0.2 wt%, or 0.01 to 0.15 wt%, or 0.01 to 0.10 wt% based on the total weight of the inventive parent mixture, formulation, and / or product.

[0076] Optional component (additive) (I) Hydrolysable silane without (unsaturated carbon-carbon bonds). Suitable for dehumidification. Component (I) can be any monosilane containing at least 1, or at least 2, or at least 3, or 4 hydrolysable groups (e.g., R as defined above 2 ) and up to 3, or up to 2, or up to 1, or 0 non-hydrolysable groups without (unsaturated carbon-carbon bonds) (such as alkyl or aryl). Examples of (I) are acetoxymethyltrimethoxysilane, 4-benzylphenylsulfonyloxytributylsilane, dimethylamino-methoxy-dioctylsilane, octyltrimethoxysilane, and tetramethoxysilane. In some aspects, (I) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (I) is present in the inventive parent mixture, formulation, and / or product in an amount of 0.1 wt% to 2 wt%, or 0.1 wt% to 1.5 wt%, or 0.1 wt% to 1.0 wt% based on its total weight.

[0077] Optional component (additive) (J) Corrosion inhibitor. For example, tin(II) sulfate. In some aspects, (J) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (J) is present in the inventive parent mixture, formulation, and / or product in an amount of 0.00001 to 0.1 wt%, or 0.0001 to 0.01 wt% based on the total weight of the inventive parent mixture, formulation, and / or product.

[0078] Optional component (additive) (K) Hindered amine light stabilizer. (K) is a compound that inhibits oxidative degradation. Examples of suitable (K) are dimethyl succinate, a polymer having 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine-ethanol (CAS No. 65447-77-0, commercially available as LOWILITE 62); and poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidyl)imino]] (CAS 71878-19-8 / 70624-18-9, Chimassorb 994LD, BASF). In some aspects, (K) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (K) is present in the inventive parent mixture, formulation, and / or product in an amount of 0.001 to 0.4 wt%, or 0.001 to 0.2 wt%, or 0.01 to 0.15 wt%, or 0.01 to 0.10 wt% based on the total weight of the inventive parent mixture.

[0079] Optional component (additive) (L) Ethylene-based copolymer additive. Component (L) is different from components (A) and (C). (L) is LDPE, an ethylene / α-olefin copolymer, or an ethylene / unsaturated carboxylate copolymer (e.g., an ethylene / vinyl acetate (EVA) copolymer, an ethylene / ethyl acrylate (EEA) copolymer, or an ethylene / ethyl methacrylate (EEMA) copolymer). In some aspects, (L) is not present in the inventive parent mixture, formulation, and / or product. In some aspects, (L) is present in the inventive parent mixture, formulation, and / or product at a concentration of 0.1 wt% to 20 wt%, or 1 wt% to 10 wt%, and / or 5 wt% to 20 wt%; all based on its total weight.

[0080] Optional component (M) Filler: A finely divided particulate solid or gel that occupies space in the host material and optionally affects the function of the host material. The (M) filler can be calcined clay, organoclay, or hydrophobic fumed silica, such as those obtained under the CAB-O-SIL trade name from Cabot Corporation. The (M) filler can have a flame retardant effect. In some aspects, the inventive formulation and product do not contain (M). When present, the (M) filler can be 1 wt% to 40 wt%, or 2 wt% to 30 wt%, or 5 wt% to 20 wt% of the inventive formulation and product.

[0081] Regarding (M) fillers, in some aspects, the formulations and products of the present invention do not contain 20 wt% or more, or do not contain 15 wt% or more, or do not contain 10 wt% or more of inorganic fillers, or do not contain inorganic fillers selected from the group consisting of: alumina, aluminum silicate, calcium silicate, magnesium silicate, silica, titanium dioxide, and mixtures thereof. The formulations and products of the present invention may not contain 20 wt% or more, or may not contain 15 wt% or more, or may not contain 10 wt% or more of inorganic fillers, or may not contain any inorganic fillers selected from the group consisting of: Al-containing solids, Ca-containing solids, Mg-containing solids, Si-containing solids, Ti-containing solids, and mixtures thereof. For the avoidance of doubt, the term "inorganic filler" does not include carbon black.

[0082] Optional component (N) Nucleating agent. An organic or inorganic additive that enhances the crystallization rate of polyolefin polymers. Examples of (N) are calcium carbonate, titanium dioxide, barium sulfate, ultra-high molecular weight polyethylene, potassium hydrogen phthalate, benzoic acid compounds, sodium benzoate compounds, disodium bicyclo[2.2.1]heptane-2,3-dicarboxylate, zinc monoglyceride, and calcium 1,2-cyclohexanedicarboxylate: zinc stearate. In some aspects, the formulations and products of the present invention do not contain (N). When present, the concentration of (N) can be 0.01 wt% to 1.5 wt%, or 0.05 wt% to 1.2 wt%, or 0.1 wt% to 1.0 wt% of the formulations and products of the present invention.

[0083] Optional component (O) Anti-treeing agent. The (O) anti-treeing agent is a molecule or a collection of such molecules that inhibits the growth of water trees and / or electrical trees. The anti-treeing agent can be a water-tree inhibitor or an electrical-tree inhibitor. A water-tree inhibitor is a compound that inhibits the growth of water trees, which is a process of polyolefin degradation when exposed to the combined action of an electric field and humidity or moisture. An electrical-tree inhibitor (also known as a voltage stabilizer) is a compound that inhibits the growth of electrical trees, which is an electrical pre-breakdown process in solid electrical insulating materials due to partial discharge. Electrical-tree growth can occur in the absence of water. Water-tree growth and electrical-tree growth are problems in cables with coated conductors, where the coating contains polyolefin. The (O) anti-treeing agent can be poly(ethylene glycol) (PEG).

[0084] Other optional components. In some aspects, the formulations and products of the present invention do not contain any optional components. In some aspects, the formulations and products of the present invention do not contain any optional components other than components (C) to (O). In some aspects, the formulations and / or products of the present invention further contain at least one optional component (additive), which is a lubricant, mineral oil, or anti-caking agent. The formulations and products of the present invention may not contain an anti-coking agent, which is not beneficial in curing formulations (such as electron beam curing formulations) that do not contain organic peroxides.

[0085] Any optional component can be suitable for imparting at least one characteristic or property to the inventive parent mixture, formulation, and / or product in need. The characteristic or property can be suitable for improving the performance of the inventive formulation and / or product in operation or application, wherein the inventive formulation and / or product is exposed to a relatively high operating temperature. Such operations or applications include melt mixing, extrusion, molding of power cables, and hot water pipes and insulation layers.

[0086] Electron beam curing formulation. The total weight of all components and additives in the inventive formulation and product is independently 100.00% by weight. The electron beam curing formulation can be a one-part formulation or a two-part formulation. The two-part formulation can include a first part and a second part, wherein the first part mainly consists of components (A) and (B), and the second part mainly consists of one or more optional components (C) to (O).

[0087] The EBC formulation and the cured polyolefin product prepared therefrom do not contain phosphazene base. The phosphazene base is a ring-opening catalyst. The excluded phosphazene base has a core structure of P=N, wherein the free N valence is connected to hydrogen, a hydrocarbon group, -P=N, or =P-N, and the free P valence is connected to =N or -N. Examples of the phosphazene base are found in US 8,426,519B2, column 9, line 29 to column 10, line 31. The excluded phosphazene base includes combinations of two or more of them.

[0088] Except for the excluded phosphazene base, certain embodiments of the EBC formulation and the cured polyolefin product prepared therefrom may also not contain other ring-opening catalysts. Examples of other ring-opening catalysts are found in F.O. Stark et al., "Silicones, Comprehensive Organometallic Chemistry", Volume 2, page 305, Pergamon Press (1982). The ring-opening catalysts include strong acids such as trifluoromethanesulfonic acid and its metal salts, sulfuric acid, perchloric acid, and hydrochloric acid; cationic ring-opening catalysts such as metal halides; and anionic ring-opening catalysts such as organolithium, alkali metal oxides, and alkali metal hydroxides; and mixtures of any two or more of them. For example, the EBC formulation and the cured polyolefin product prepared therefrom may not contain an acid condensation catalyst, which is (i) an organic sulfonic acid, an organic phosphonic acid, or a hydrogen halide; (ii) an organic sulfonic acid; (iii) an aryl sulfonic acid substituted by an alkyl group; (iv) an aryl sulfonic acid substituted by an alkyl group, wherein there is 1 or 2 (C5-C 20an alkyl substituent and one aryl group that is phenyl or naphthyl; (v) (C1-C5) alkylphosphonic acid, where the (C1-C5) alkyl is unsubstituted or substituted with an -NH2 group; (vi) HF, HCl, or HBr; (vii) a Lewis acid; or (viii) a combination of any two or more of (i) to (vii). Other excluded ring-opening catalysts include combinations of two or more of them.

[0089] The EBC formulation and the cured polyolefin product prepared therefrom do not contain a semi-crystalline polyolefin having a crystallinity of 50 wt% or greater. The crystallinity of the excluded semi-crystalline polyolefin can be at least 55 wt%, or at least 58 wt%, or at least 59 wt%. In any of the foregoing aspects, the crystallinity can be at most 90 wt%, or at most 80 wt%, or at most 78 wt%. In some aspects, the crystallinity is 55 to 80 wt%, or 58 to 78 wt%, or 58 to 76 wt%, or 62 to 78 wt%, or any one of 59±1 wt%, 62±1 wt%, 76±1 wt%, and 77±1 wt%. The excluded semi-crystalline polyolefin having a crystallinity of 50 wt% or greater includes combinations of two or more of them.

[0090] The excluded semi-crystalline polyolefin can be a semi-crystalline polyethylene having a crystallinity of 50 wt% or greater. Examples are semi-crystalline medium-density polyethylene (MDPE), semi-crystalline high-density polyethylene (HDPE), or a combination thereof, all having a crystallinity of 50 wt% or greater. The maximum density of the excluded semi-crystalline HDPE can be 0.970 g / cm 3 , or at most 0.960 g / cm 3 , or at most 0.950 g / cm 3 . The density of the excluded semi-crystalline HDPE can be >0.935 to 0.970 g / cm 3 , or 0.935 to 0.965 g / cm 3. The density of (A) can be measured by ASTM D-1505, "Test Method for Density of Plastics by the Density-Gradient Technique". The melt index (I2, 190 °C / 2.16 kg load) of the excluded semi-crystalline polyolefin can be 10 to 20 g / 10 min, or 0.1 to 10 g / 10 min, or 0.20 to 9 g / 10 min. I2 can be determined by ASTM D1238 as described later. The excluded semi-crystalline polyolefin can have a unimodal molecular weight distribution (MWD), or be multimodal, such as bimodal. The excluded semi-crystalline polyolefin can be bimodal and have a density of 0.950 to 0.958 g / cm 3 and semi-crystalline HDPE with a melt index of 0.20 to 0.40 g / 10 min. The excluded semi-crystalline polyolefin can be unimodal semi-crystalline HDPE and have a density of 0.930 to 0.970 g / cm 3 and a melt index of 0.65 to 9 g / 10 min. Or a density of 0.935 to 0.965 g / cm 3 and a melt index of 0.7 to 8.5 g / 10 min.

[0091] The EBC formulation and the cured polyolefin product prepared therefrom do not contain organic peroxides. The excluded organic peroxides are molecules containing carbon atoms, hydrogen atoms, and two or more oxygen atoms and having at least one -O-O- group, provided that when there is more than one -O-O- group, each -O-O- group is indirectly bonded to another -O-O- group or a collection of such molecules via one or more carbon atoms. The excluded organic peroxides include monoperoxides of the formula RO-O-O-RO, where each RO is independently a (C1-C 20 ) alkyl group or a (C6-C 20 ) aryl group. Each (C1-C 20 ) alkyl group is independently unsubstituted or substituted with 1 or 2 (C6-C 12 ) aryl groups. Each (C6-C 20 ) aryl group of RO is independently unsubstituted or substituted with 1 to 4 (C1-C 10 ) alkyl groups. The excluded organic peroxides also include diperoxides of the formula RO-O-O-R-O-O-RO, where R is a divalent hydrocarbon group, such as (C2-C 10 ) alkylene, (C3-C 10)A cycloalkylene or a phenylene group, and each RO is as defined above. Excluded organic peroxides include bis(1,1-dimethylethyl) peroxide; bis(1,1-dimethylpropyl) peroxide; 2,5-dimethyl-2,5-bis(1,1-dimethylethyl)hexane; 2,5-dimethyl-2,5-bis(1,1-dimethylethylperoxy)hexyne; 4,4-bis(1,1-dimethylethylperoxy)valeric acid; butyl ester; 1,1-bis(1,1-dimethylethylperoxy)-3,3,5-trimethylcyclohexane; benzoyl peroxide; tert-butyl peroxybenzoate; di-tert-amyl peroxide ("DTAP"); bis(α-tert-butyl-peroxyisopropyl)benzene ("BIPB"); cumyl tert-butyl peroxide; tert-butyl cumyl peroxide; di-tert-butyl peroxide; 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane; 2,5-bis(tert-butylperoxy)-2,5-dimethylhexyne-3, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane; cumyl cumyl cumyl peroxide; butyl 4,4-bis(tert-butylperoxy)valerate; or di(cumyl) peroxide; or dicumyl peroxide. Excluded organic peroxides include combinations of two or more such organic peroxides.

[0092] Some embodiments of the EBC formulation and the cured polyolefin product prepared therefrom may also be free of inorganic fillers selected from alumina, aluminum silicate, calcium silicate, magnesium silicate, silica, titanium dioxide, and mixtures of any two or more thereof.

[0093] Some embodiments of the EBC formulation and the cured polyolefin product prepared therefrom are free of each of a phosphazene base, a semi-crystalline polyolefin having a crystallinity of 50 wt% or greater, an organic peroxide, a ring-opening catalyst other than a phosphazene base, and an inorganic filler. In some such embodiments, the EBC formulation and the cured polyolefin product prepared therefrom are also free of (C) a carbon-based additive, TiO2, or (C) a carbon-based additive and TiO2. The formulations and products of the present invention may be free of sesquioxanes, or any siloxanes other than component (B) and the electron beam curing (crosslinking) reaction product of (B).

[0094] (C3-C 20 ) α-olefins and (C3-C 20 ) α-olefins. A compound of formula (I): H2C═C(H)-R (I), wherein R is a straight-chain (C1-C 18 ) alkyl group or a straight-chain (C2-C 18 ) alkyl group. The (C3) α-olefin is 1-propene and its R group in formula (I) is a methyl group. The (C2-C 18 ) alkyl group is a monovalent unsubstituted saturated hydrocarbon having 2 to 18 carbon atoms. The (C2-C18 ) Examples of alkyl groups are ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. In some embodiments, (C4-C 20 ) The α-olefin is 1-butene, 1-hexene or 1-octene; or 1-butene, 1-hexene or 1-octene; or 1-butene or 1-hexene; or 1-butene or 1-octene; or 1-hexene or 1-octene; or 1-butene; or 1-hexene; or 1-octene; or any combination of any two of 1-butene, 1-hexene and 1-octene.

[0095] Any compound herein includes all its isotopic forms, including natural abundance forms and / or isotope-enriched forms, which may have additional uses, such as medical or anti-counterfeiting applications.

[0096] A method of electron beam radiation curing. The method may include subjecting an EBC formulation to electron beam irradiation with an effective dose of electron beam radiation. The effective or absorbed dose of electron beam radiation can be 49 to 201 kilojoules of energy per kilogram of EBC formulation (kJ / kg), or 49 to 160 kJ / kg, or 80 to 201 kJ / kg, or 80 to 160 kJ / kg, or 50 to 80 kJ / kg, or 100 to 140 kJ / kg, or 160 to 201 kJ / kg. 100 kJ / kg is equal to 10 megarad (Mrad) / kg which is equal to 100,000 Gray. 1 Gray = 1 joule / kilogram (J / kg) = 100 rad. The electron beam radiation can be generated using an electron beam accelerator machine, such as the Aibang AB5.0 machine available from Aibang Radiation Technology Company, Limited, Wuxi, China. The electron beam irradiation step can be carried out at any suitable temperature, for example, from 10 °C to 50 °C (e.g., 23 °C ± 1 °C), in any suitable atmosphere (e.g., air or molecular nitrogen), and for any suitable length of time, for example, from 0.1 to 20 minutes, or 0.1 to 10 minutes, or 0.1 to 5 minutes. The radiation can be delivered continuously or intermittently, or continuously.

[0097] Unless otherwise indicated, the following applies. Or prior to a different embodiment. ASTM means the standards organization, ASTM International, West Conshohocken, Pennsylvania, USA. IEC means the standards organization, International Electrotechnical Commission, Geneva, Switzerland. Any comparative examples are used for illustrative purposes only and should not be prior art. Absence or lack means complete absence; or undetectable. "IUPAC" is the International Union of Pure and Applied Chemistry (IUPAC Secretariat, Research Triangle Park, North Carolina, USA). "May" confers an option, not a necessity. Operate means functionally capable or effective. "Optional(ly)" means absent (or excluded), or present (or included). PPM is weight-based. Properties are measured using standard test methods and measurement conditions (e.g., viscosity: 23 °C and 101.3 kPa). A range includes the endpoints, sub-ranges, and all and / or part of the values included therein, except for integer ranges that do not include fractional values. Room temperature is 23 °C ± 1 °C. When referring to a compound, substituted means having one or more substituents in place of hydrogen, up to and including full substitution.

[0098] Crystallinity test method. For determining the crystallinity in weight % of a semi-crystalline polyolefin resin, such as (A) a semi-crystalline polyolefin carrier resin. The melting peak and the weight percentage (wt%) crystallinity are determined using a DSC instrument, DSC Q1000 (TA Instruments), as follows. Procedure (A) Baseline calibrator. Use the software calibration wizard. First, obtain the baseline by heating the cell from -80 °C to 280 °C without any sample in an aluminum DSC pan. Then use a sapphire standard according to the instructions of the calibration wizard. Analyze 1 to 2 milligrams (mg) of fresh indium sample by heating the standard sample to 180 °C, cooling it at a cooling rate of 10 °C / minute to 120 °C, then holding the standard sample isothermally at 120 °C for 1 minute, and subsequently heating the standard sample from 120 °C to 180 °C at a heating rate of 10 °C / minute. Determine the heat of fusion (H f ) = 28.71 ± 0.50 joules / gram (J / g) and the melting onset = 156.6 °C ± 0.5 °C. Perform DSC measurements on the test samples using the same DSC instrument. For polyethylene test samples, see the following Procedure (B). For polypropylene test samples, see the following Procedure (C). The weight percentage of crystallinity determined using DSC will be approximately 3 weight % lower than the weight percentage of crystallinity determined according to the density-based method.

[0099] Procedure (B): DSC of polyethylene test samples. The test samples of the polymer are pressed into films at a temperature of 160 °C. Weigh 5 to 8 mg of the test sample film in the DSC pan. Press the lid onto the pan to seal the pan and ensure airtightness. Place the sealed pan in the DSC unit, equilibrate the unit at 30 °C, and heat it to 140 °C at a rate of approximately 100 °C / min. Hold the sample at 140 °C for 1 minute, cool the sample to 0 °C or lower (e.g., -40 °C) at a rate of 10 °C / min to obtain the cooling curve melting heat (H f ), and isothermally hold it at 0 °C or lower (e.g., -40 °C) for 3 minutes. Then heat the sample again to 180 °C at a rate of 10 °C / min to obtain the second heating curve melting heat (ΔH f ). Using the resulting curves, calculate the cooling curve melting heat (J / g) by integrating from the onset of crystallization to 10 °C. Calculate the second heating curve melting heat (J / g) by integrating from 10 °C to the end of melting. Measure the weight percentage of crystallinity (weight % crystallinity) of the polymer from the second heating curve melting heat (ΔH f ) of the test sample, and normalize it to the melting heat of 100% crystalline polyethylene, where weight % crystallinity = (ΔH f * 100%) / 292 J / g, where ΔH f is as defined above, * indicates mathematical multiplication, / indicates mathematical division, and 292 J / g is the literature value of the melting heat (ΔH f ) of 100% crystalline polyethylene.

[0100] Procedure (C): DSC on polypropylene test samples. The test samples of polypropylene are pressed into films at a temperature of 210 °C. Weigh 5 to 8 mg of the test sample film in the DSC pan. Press the lid onto the pan to seal the pan and ensure airtightness. Place the sealed pan in the DSC cell and heat it to 230 °C at a rate of approximately 100 °C / min, hold the sample at 230 °C for 5 minutes, cool the sample to -20 °C at a rate of 10 °C / min to obtain the cooling curve melting heat, and isothermally hold it at -20 °C for 5 minutes. Then heat the sample again to the end of melting at a rate of 10 °C / min to obtain the second heating curve melting heat ((ΔH f ). Using the resulting curves, calculate the cooling curve melting heat (J / g) by integrating from the onset of crystallization to 10 °C. Calculate the second heating curve melting heat (J / g) by integrating from 10 °C to the end of melting. Measure the weight percentage of crystallinity (weight % crystallinity) of the polymer from the second heating curve melting heat (ΔH f ) of the test sample, and normalize it to the melting heat of 100% crystalline polypropylene, where weight % crystallinity = (ΔH f * 100%) / 165 J / g, where ΔH fAs defined above, * indicates mathematical multiplication, / indicates mathematical division, and 165 J / g is the literature value of the heat of fusion (ΔH f ) of 100% crystalline polypropylene.

[0101] Density test method: Measured according to ASTM D792-13, Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement, Method B (for testing solid plastics in liquids other than water, such as in the liquid 2-propanol). The reported results are in grams per cubic centimeter (g / cm 3 ).

[0102] Gel content test method: Measured by ASTM D2765-01(2006), Standard Test Methods for Determination of Gel Content and Swell Ratio of Crosslinked Ethylene Plastics, Test Method A.

[0103] Thermal creep (thermal setting) test method: Place the test sample (dog bone shape with dimensions specified in ASTM 638-34; thickness < 2 millimeters (mm); marking lines 20 mm apart) in an oven at 200 °C, and apply a force equal to 20 Newtons per square centimeter (N / cm 2) weights are attached to the test sample. Then the elongation of the test sample (the distance between the marked lines) is measured under these conditions and expressed as a percentage of the initial 20 mm distance. For illustration, if the distance between the marked lines widens to 40 mm, then the thermal creep is 100% (100*(40 - 20) / 20) = 100%), and if it widens to 100 mm, then the thermal creep is 400%. All other conditions being the same, the lower the crosslinking level in the test sample, the greater the elongation in the thermal creep test method. Conversely, the higher the crosslinking level in the test sample, the smaller the elongation. If the crosslinking level in the test sample is low enough, the test sample may fail due to rupture, which may occur within the first few minutes or even seconds of its test operation. Although power cables may not experience operating temperatures as high as 200 °C, this test is a reliable way for the industry to evaluate materials used for their insulation. The lower the thermal creep percentage, the better the performance of the material. In the power cable industry, after the test sample is held at 200 °C for 15 minutes, a thermal creep of less than 175% passes the thermal creep test. And a thermal creep of less than 100% after 15 minutes at 200 °C is particularly desirable. If the test sample is intact after 15 minutes, the weights are removed, the test sample is taken out of the oven and cooled to room temperature. The residual elongation rate of the test sample after cooling is measured. For power cables, the residual elongation rate at room temperature should be less than 15% of the thermal creep value measured at 200 °C.

[0104] Melt flow rate (230 °C, 2.16 kilograms (kg), "MFR") test method: For propylene-based (co)polymers, the conditions of 230 °C / 2.16 kg, previously called "Condition E" and also known as MFR, are used and measured according to ASTM D1238-13. The results are reported in grams eluted per 10 minutes (g / 10 minutes) or equivalently in decigrams per 1.0 minute (dg / 1 minute). 10.0 dg = 1.00 g.

[0105] Melt index (190 °C, 2.16 kilograms (kg), "I2") test method: For ethylene-based (co)polymers, the conditions of 190 °C / 2.16 kg, previously called "Condition E" and also known as I2, are used and measured according to ASTM D1238-13. The results are reported in grams eluted per 10 minutes (g / 10 minutes) or equivalently in decigrams per 1.0 minute (dg / 1 minute). 10.0 dg = 1.00 g.

[0106] Quick test method (qualitative): Add a polyethylene pellet sample with an additive to a separate unused sealed polyethylene plastic bag (also known as a zip lock bag or click seal bag). Seal the bag. Press the pellets into the bag. Store the bag and its contents at room temperature for 14 days. Within 14 days, observe the oil traces remaining on the surface of the bag under light. The oil traces indicate surface migration and poor solubility. More oil traces on the bag surface mean more additive sweating. Gradually rank the sweating amount by characterizing the oil traces as none, very few, almost none, or obvious (more than very few).

[0107] Examples

[0108] EBC polyolefin compound (A1): Low-density polyethylene (LDPE) product number DXM446, with a crystallinity of 45 wt%, a density of 0.92 g / cm3, and a melt index (I2) of 2 g / 10 min, and obtained from Dow Chemical Company.

[0109] EBC polyolefin compound (A2): Ethylene-propylene-diene monomer (EPDM) copolymer product number NORDEL4725, with a crystallinity of 12 wt% measured by ASTM D1646 at 125 °C, a density of 0.88 g / cm 3 and a Mooney viscosity (ML 1+4) of 25; and obtained from Dow Chemical Company.

[0110] EBC polyolefin compound (A3): Ethylene-octene (POE) copolymer product number ENGAGE8150, with a crystallinity of 16 wt%, a density of 0.868 g / cm 3 and a melt index (I2) of 0.5 g / 10 min, and obtained from Dow Chemical Company.

[0111] Alkylene-functionalized monocyclic organosiloxane (B1): Tetramethyl-tetravinyl-cyclotetrasiloxane (ViD4) obtained from Dow Chemical Company.

[0112] Compounds (A1) to (A3) do not contain antioxidants and stabilizers.

[0113] Carbon-based additive (C1): Trimethylolpropane trimethacrylate (TMPTMA).

[0114] Carbon-based additive (C2): Triallyl isocyanurate (TAIC).

[0115] Comparative Examples 1 to 9 (CE1 to CE9): Comparative EBC formulations CE1 to CE9: melt blended LDPE (A1), EPDM (A2), or POE (A3), as appropriate, as described later in the table; and using a compounding temperature of 155 °C, with or without a carbon-based additive (C1) or (C2) in a Banbury mixer, at a rotor speed of 60 to 65 revolutions per minute (rpm), then extruding the melt of the additive masterbatch mixture under air cooling to obtain an extruded additive masterbatch mixture, and pelletizing the extruded additive masterbatch mixture to obtain the comparative EBC formulations CE1 to CE9, respectively as pellets. For composition data, see Table 1.

[0116] Comparative Examples A and I (CE(A) to CE(I)): Comparative cured polyolefin products prepared by thermally pressing different ones of Comparative Formulations CE1 to CE9 at 120 °C, respectively, to form the formulations into 1 mm thick sheets, and then curing the sheets with an electron beam radiation dose of 100 kilojoules per kilogram (kJ / kg) to obtain the comparative cured products CE(A) to CE(I), respectively. For property data, see Table 1.

[0117] Examples 1 to 5 of the Invention (IE1 to IE5): EBC formulations 1 to 4 of the invention. Melt blended LDPE (A1), EPDM (A2), or POE (A3), as appropriate, as described later in the table; and using a compounding temperature of 155 °C in a Banbury mixer with a silicon-based additive (B1), at a rotor speed of 60 to 65 revolutions per minute (rpm), then extruding the melt of the EBC formulation under air cooling to obtain an extruded EBC formulation, and pelletizing the extruded EBC formulation to obtain the EBC formulations IE1 to IE5, respectively as pellets. For composition data, see Table 2.

[0118] Examples A to E of the Invention: Cured polyolefin products IE(A) to IE(E) of the invention. Prepared by curing the EBC formulations of IE1 to IE5 with an electron beam radiation dose of 100 kilojoules per kilogram (kJ / kg), respectively, to obtain the cured polyolefin products IE(A) to IE(E), respectively. For property data, see Table 2.

[0119] Table 1: Compositions (wt%) and properties: CE1 to CE9 / CE(A) to CE(I).

[0120]

[0121] *Failure: CE1 / (A) ruptured at 3 minutes, CE2 / (B) ruptured at 5 minutes, CE3 / (C) ruptured at 8 minutes, CE4 / (D) ruptured at 14 minutes. **N / A means not applicable. ^ is to indicate obvious.

[0122] Table 2: Composition (wt%) and properties: IE1 to IE5 / IE(A) to IE(E).

[0123]

[0124] *N / m indicates not measured.

[0125] The thermal creep data in Table 1 and Table 2 show that the EBC formulations of the present invention are significantly better upon curing, resulting in a cured polyolefin product of the present invention with improved (reduced) thermal creep at 200 °C compared to a comparative cured polyolefin product prepared from a comparative EBC formulation. The ViD4 (B1) sweating of the EBC formulation of the present invention is also less than the TAIC (C1) or TMPTMA (C2) sweating of the comparative EBC formulation, which is beneficial for achieving a higher loading of (B) a carbon-based additive in (A) an EBC polyolefin compound (such as LDPE, EPDM, or POE) in the EBC formulation of the present invention than in the same LDPE, EPDM, or POE in the comparative EBC formulation. The higher loading in (B) the EBC formulation of the present invention can increase the efficiency of its electron beam curing, such that a lower dose of the absorbed electron beam radiation can be used to achieve a given cured state, or such that the same dose of the absorbed electron beam radiation can produce a greater cured state (a greater amount of crosslinking).

Claims

1. An electron beam curable EBC formulation comprising components (A) and (B): (A) An electron beam curable EBC polyolefin compound having a density of 0.930 g / cm 3 or less as measured by ASTM D792 - 13 Method B, and optionally having a crystallinity of 0 to less than 50 wt% as measured by a crystallinity test method using differential scanning calorimetry DSC; and (B) An alkenyl - functional monocyclic organosiloxane having the formula (I): [R 1 ,R 2 SiO 2 / 2 n (I), where the subscript n is an integer greater than or equal to 3; each R 1 is independently a C2 - C4 alkenyl or H2C=C(R 1a ) - C(=O) - O - (CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H, a C1 - C4 alkyl, phenyl or R 1 ; where (A) is 90.0 to 99.4 wt% of the combined weight of components (A) and (B), and (B) is 10 to 0.6 wt% of the combined weight of components (A) and (B); and provided that the EBC formulation does not contain each of phosphazene base, semi - crystalline polyolefins with a crystallinity of 50 wt% or greater, and organic peroxides; where in the (B) alkenyl - functional monocyclic organosiloxane of formula (I), the subscript n is 4, and where the EBC formulation is described by any one of the restrictions (i) to (iv): (i) Each R 1 is independently a C2 - C3 alkenyl; and each R 2 is independently H, a C1 - C2 alkyl or a C2 - C3 alkenyl; (ii) Each R 1 is independently H2C=C(R 1a ) - C(=O) - O - (CH2) m- , where R 1a is H or methyl and the subscript m is an integer from 1 to 4; and each R 2 is independently H or a C1 - C2 alkyl; (iii) The EBC formulation does not contain 24 wt% or more of any inorganic filler; and (iv) A combination of restriction (iii) and any one of restrictions (i) to (ii).​ 2. The electron beam curable EBC formulation according to claim 1, wherein the (A) EBC polyolefin compound is characterized by any one of (v) to (x): (v) Each R 1 is vinyl; and each R 2 is independently a C1-C2 alkyl group; (vi) Each R 1 is allyl; and each R 2 is independently a C1-C2 alkyl group; (vii) Each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H and the subscript m is 3; and each R 2 is independently a (C1-C2) alkyl group; (viii) Each R 1 is independently H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is methyl and the subscript m is 3; and each R 2 is independently a C1-C2 alkyl group; (ix) The EBC formulation does not contain 24 wt% or more of any inorganic filler; and (x) A combination of limitation (ix) and any one of limitations (v) to (viii).

3. The electron beam curable EBC formulation according to claim 1 or 2, wherein the (A) EBC polyolefin compound is characterized by any one of (xi) to (xiv): (xi) Each R 1 is vinyl; and each R 2 is methyl; (xii) Each R 1 is allyl; and each R 2 is methyl; (xiii) The EBC formulation does not contain 24 wt% or more of any inorganic filler; and (xiv) A combination of limitation (xiii) and any one of limitations (xi) to (xii).

4. The electron beam curable EBC formulation according to claim 1 or 2, wherein the (A) EBC polyolefin compound is characterized by any one of (i) to (x): (i) The crystallinity is measured by a crystallinity test method to be > 0 to less than 50.0% by weight, and the crystallinity test method is carried out using differential scanning calorimetry (DSC); (ii) According to the melt index test method, the melt index I2 measured at 190 °C / 2.16 kg load is 0.1 to 20 g / 10 min, and it is polyethylene; (iii) According to the melt flow rate test method, the melt flow rate MFR measured at 230 °C / 2.16 kg load is 0.5 to 20 g / 10 min, and it is polypropylene; (iv) The molecular weight distribution MWD is unimodal or multimodal; (v) The combined weight of components (A) and (B) is 50 to 100% by weight of the electron beam curable EBC formulation; (vi) The (A) EBC polyolefin compound is low density polyethylene LDPE with a density of 0.910 to 0.925 g / cm 3 ; (vii) The (A) EBC polyolefin compound is linear low density polyethylene LLDPE with a density of 0.910 to 0.925 g / cm 3 ; (viii) The (A) EBC polyolefin compound is an ethylene / C3-C 20 α-olefin copolymer; (ix) The (A) EBC polyolefin compound is an ethylene-propylene-diene monomer EPDM copolymer; and (x) The (A) EBC polyolefin compound is a combination of any two or more of (i) to (ix).

5. The electron beam curable EBC formulation according to claim 1 or 2, wherein the (A) EBC polyolefin compound is a polyethylene elastomer selected from ethylene-propylene rubber EPR, ethylene-1-butene rubber EBR, and ethylene-1-octene rubber EOR.

6. The electron beam curable EBC formulation according to claim 1 or 2, wherein the (A) EBC polyolefin compound is an ethylene-propylene copolymer EPP.

7. The electron beam curable EBC formulation according to claim 1 or 2, further comprising at least one additive independently selected from optional components (C) to (O): (C) a carbon-based auxiliary agent, wherein the carbon-based auxiliary agent comprises a substructural group bonded to two or more olefin crosslinking groups, and the substructural group is an acyclic or cyclic polyvalent group, which respectively includes a main chain or a ring, and optionally contains nitrogen and / or oxygen atoms in the main chain or ring carbon atoms, but does not contain silicon atoms; (D) a flame retardant; (E) an antioxidant; (F) a processing aid, wherein the processing aid improves the fluidity of the melt of the auxiliary agent parent mixture through a machine; (G) a colorant; (H) a metal deactivator; (I) a hydrolyzable silane without an unsaturated carbon-carbon bond; (J) a corrosion inhibitor; (K) a hindered amine light stabilizer; (L) an ethylene-based copolymer, which is different from component (A) and different from the semi-crystalline polyolefin with a crystallinity of 50 wt% or more, and wherein (L) is an ethylene / C4-C 20 α-olefin copolymer, an ethylene / unsaturated carboxylate copolymer or a propylene / ethylene-based copolymer; (M) a filler; (N) a nucleating agent; and (O) an anti-treeing agent, wherein the anti-treeing agent is a molecule or a collection of molecules that inhibits the growth of water trees and / or the growth of electrical trees, and the growth of water trees is a process of polyolefin degradation when exposed to the combined action of an electric field and humidity or moisture, and the growth of electrical trees is an electrical pre-breakdown process in a solid electrical insulating material due to partial discharge.

8. The electron beam curable EBC formulation according to claim 7, wherein the colorant is carbon black.

9. A method for manufacturing the electron beam curable EBC formulation according to any one of claims 1 to 6, the method comprising mixing the separated solid form or molten form of the (A) EBC polyolefin compound with the (B) alkenyl-functional monocyclic organosiloxane of formula (I) and any optional components (C) to (O) together to obtain a mixture mainly composed of components (A), (B) and any optional components (C) to (O), thereby manufacturing the electron beam curable EBC formulation; provided that the method is free of each of phosphazene base, semi-crystalline polyolefin having a crystallinity of 50 wt% or more, and organic peroxide, wherein the optional components (C) to (O) are: (C) a carbon-based auxiliary agent, wherein the carbon-based auxiliary agent comprises a substructural group bonded to two or more olefin crosslinking groups, wherein the substructural group is an acyclic or cyclic polyvalent group, which respectively includes a main chain or a ring, optionally containing nitrogen and / or oxygen atoms in the main chain or ring carbon atoms, but not containing silicon atoms; (D) a flame retardant; (E) an antioxidant; (F) a processing aid, wherein the processing aid improves the flowability of the melt of the auxiliary agent parent mixture through a machine; (G) a colorant; (H) a metal deactivator; (I) a hydrolyzable silane free of unsaturated carbon-carbon bonds; (J) Corrosion inhibitor; (K) Hindered amine light stabilizer; (L) Ethylene-based copolymer, which is different from component (A) and different from the semi-crystalline polyolefin having a crystallinity of 50% by weight or more, where (L) is ethylene / C4-C 20 α-olefin copolymer, ethylene / unsaturated carboxylate copolymer or propylene / ethylene-based copolymer; (M) Filler; (N) Nucleating agent; and (O) Anti-treeing agent, where the anti-treeing agent is a molecule or a collection of molecules that inhibits the growth of water trees and / or electrical trees, and the growth of water trees is a process of polyolefin degradation when exposed to the combined action of an electric field and humidity or moisture, and the growth of electrical trees is an electrical pre-breakdown process in a solid electrical insulating material due to partial discharge.

10. The method according to claim 9, wherein there is at least one of components (C) to (O).

11. The method according to claim 9 or 10, wherein the colorant is carbon black.

12. A method for electron beam curing a formulation in need thereof, the method comprising irradiating the EBC formulation according to any one of claims 1 to 8 or the electron beam curable EBC formulation manufactured by the method according to claim 9 with an effective dose of electron beam radiation to obtain an electron beam cured polyolefin product.

13. An electron beam-cured polyolefin product manufactured by the method according to claim 12.

14. An article comprising the electron beam-cured polyolefin product according to claim 13 and a component in operative contact therewith.

15. A coated conductor comprising a conductive core and a polymeric layer at least partially surrounding the conductive core, wherein at least a portion of the polymeric layer comprises the electron beam-cured polyolefin product according to claim 13.

16. A method of conducting electricity, the method comprising applying a voltage across the conductive core of the coated conductor according to claim 15 to produce an electric current through the conductive core.

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