Composition, preparation method and application thereof

Abstract

The present invention relates to the technical field of composite materials, disclose a kind of composition and its preparation method and application, described composition includes: resin, conductive carbon black, the first antioxidant, the second antioxidant and cross-linking agent;Wherein, the mass content of metal elements in described conductive carbon black is not more than 10ppm;Wherein, described first antioxidant is 2,4,6-tris (3 ', 5 '-di-t-butyl-4 '-hydroxybenzyl) mesitylene and / or 1,3,5-tris (3,5-di-t-butyl-4 hydroxybenzyl) isocyanuric acid;Wherein, described second antioxidant is bis (2,6-di-t-butyl-4 methylphenyl) pentaerythritol diphosphate and / or pentaerythritol tetrakis (3 lauryl thiopropionate).The composition provided by the present invention not only has excellent anti-insulation yellowing characteristic as semi-conductive shielding material, also has excellent mechanical property, electrical conductivity, ensures the better application of material in preparing power cable.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a composition, a preparation method and an application thereof. Background Art

[0002] Power cables are generally composed of a metal conductor, an inner semi-conductive shielding layer, an insulating layer, an outer semi-conductive shielding layer, and an outer protective material. The semi-conductive shielding layer serves to uniformly distribute the electric field and protect the primary insulating material, and its performance significantly impacts the operational stability of the entire cable system. Current semi-conductive shielding materials are generally made by blending chemically cross-linked polyolefins and conductive carbon black. While the preparation process is relatively mature, severe yellowing of the insulating layer at the interface between the semi-conductive shielding material and the insulating material is a common problem, typically with a yellowness index greater than 5. This is primarily due to the impact of the semi-conductive shielding material on the insulating interface during the three-layer co-extrusion process in cable production and the subsequent cable vulcanization process. Summary of the Invention

[0003] The present invention aims to overcome the above problems in the prior art and provides a composition, a preparation method thereof and an application thereof. The composition is applied to semi-conductive shielding materials and has excellent insulation yellowing resistance.

[0004] The first aspect of the present invention provides a composition comprising: a resin, conductive carbon black, a first antioxidant, a second antioxidant, and a crosslinking agent;

[0005] Wherein, the mass content of the metal element in the conductive carbon black is not greater than 10 ppm;

[0006] Wherein, the first antioxidant is 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-mesitylene and / or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanuric acid;

[0007] Wherein, the second antioxidant is bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate and / or pentaerythritol tetrakis(3-laurylthiopropionate).

[0008] Preferably, the mass ratio of the resin to the conductive carbon black is 1:0.35-0.9.

[0009] Preferably, the weight ratio of the resin to the total amount of the first antioxidant and the second antioxidant is 1:0.001-0.1.

[0010] Preferably, the mass content of metal elements in the conductive carbon black is not more than 5 ppm; and / or the mass content of Fe element in the conductive carbon black is not more than 2 ppm; and / or the oil absorption value of the conductive carbon black is 90-350 mL / 100 g; and / or the ash mass content of the conductive carbon black is ≤0.01%.

[0011] The second aspect of the present invention provides a method for preparing the composition according to the first aspect, wherein the method comprises the following steps:

[0012] S1: extruding and granulating the resin, conductive carbon black, the first antioxidant, the second antioxidant, and optionally the lubricating dispersant to obtain pellets;

[0013] S2: mixing the pellets with a cross-linking agent to obtain the composition.

[0014] The third aspect of the present invention provides use of the composition described in the first aspect or the composition prepared by the preparation method described in the second aspect in a semiconductive shielding material.

[0015] A fourth aspect of the present invention provides use of the composition described in the first aspect or the composition prepared by the preparation method described in the second aspect in preparing a power cable.

[0016] The present invention uses a composition of conductive carbon black with a low metal element content and a high-temperature resistant antioxidant as a semi-conductive shielding material, which not only has excellent resistance to insulation yellowing, but also has excellent mechanical properties and conductive properties. After the cable is extruded, the yellow coefficient of the insulation layer at the contact point with the outer shield is ≤4, and the electrical strength of the insulation layer is improved, ensuring the better application of the material in the preparation of power cables. DETAILED DESCRIPTION

[0017] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0018] The first aspect of the present invention provides a composition comprising: a resin, conductive carbon black, a first antioxidant, a second antioxidant, and a crosslinking agent;

[0019] Wherein, the mass content of metal elements in the conductive carbon black is not greater than 5ppm;

[0020] Wherein, the first antioxidant is 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-mesitylene and / or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanuric acid;

[0021] Wherein, the second antioxidant is bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate and / or pentaerythritol tetrakis(3-laurylthiopropionate).

[0022] The present invention utilizes a composition comprising conductive carbon black containing no more than 5 ppm of metal elements by mass and an antioxidant formulated with a specific composition as a semiconductive shielding material, resulting in not only excellent resistance to yellowing of insulation but also excellent mechanical and electrical properties. The amounts of the resin, conductive carbon black, primary antioxidant, secondary antioxidant, and crosslinking agent in the composition can be selected over a wide range and can be adjusted according to conventional amounts in the art.

[0023] Preferably, the mass ratio of the resin to the conductive carbon black is 1:0.35-0.9, for example, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9 or a range consisting of any two ratios; further preferably, the mass ratio of the resin to the conductive carbon black is 1:0.45-0.8.

[0024] Preferably, the weight ratio of the resin to the total amount of the first antioxidant and the second antioxidant is 1:0.001-0.1, for example, 1:0.005, 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, or a range consisting of any two of these ratios; more preferably, 1:0.005-0.05. The antioxidant dosage in this preferred embodiment further improves the high-temperature resistance of the resulting cable during the vulcanization process and helps ensure that the composition of the present invention, as a semi-conductive shielding material, has excellent insulation yellowing resistance.

[0025] The present invention provides a wide range of selection for the relative dosage ratio of the first antioxidant to the second antioxidant. Preferably, the mass ratio of the first antioxidant to the second antioxidant is 1:(0.2-5), such as 1:0.2, 1:0.3, 1:0.5, 1:1, 1:1.3, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or any range consisting of two such ratios. More preferably, it is 1:(0.5-2), and even more preferably, 1:(0.6-1.2). The above preferred dosage ratio of the two antioxidants is more conducive to improving the high-temperature resistance of the resulting cable during the vulcanization process and ensuring that the composition of the present invention, as a semi-conductive shielding material, has excellent insulation yellowing resistance.

[0026] The present invention has no particular limitation on the resin, and it can be any polymer suitable for use as a semiconductive shielding material. Preferably, the resin is selected from at least one of ethylene butyl acrylate copolymer, ethylene vinyl acetate copolymer, and ethylene octene copolymer, and more preferably ethylene butyl acrylate copolymer.

[0027] The present invention has no particular limitation on the source of the resin, which can be purchased commercially or prepared by any existing method.

[0028] According to the present invention, preferably, the melt index of the ethylene butyl acrylate copolymer at 190°C under a load of 2.16 kg is 6-25 g / 10 min, preferably 6-20 g / 10 min, and the mass content of butyl acrylate is 10-40%, preferably 13-30%.

[0029] According to the present invention, preferably, the ethylene vinyl acetate copolymer has a melt index of 2.5-25 g / 10 min at 190° C. and a load of 2.16 kg, and the mass content of vinyl acetate is 12-33%.

[0030] According to the present invention, preferably, the ethylene octene copolymer has a melt index of 0.5-15 g / 10 min at 190° C. and under a load of 2.16 kg.

[0031] The resin of the above preferred embodiment is more conducive to the dispersion of conductive carbon black and antioxidant in the resin system.

[0032] In the present invention, the melt index is measured by ASTM D1238 at 190° C. with a test load of 2.16 kg.

[0033] The present invention has a wide range of selection for the type and amount of the cross-linking agent, and those skilled in the art can make an adaptive selection based on the compatibility of the base resin type, conductive properties, and mechanical properties.

[0034] Preferably, the cross-linking agent is selected from di-tert-butyl cumene peroxide and / or dicumyl peroxide, more preferably di-tert-butyl cumene peroxide.

[0035] According to a preferred embodiment of the present invention, the mass ratio of the resin to the crosslinking agent is 1:(0.01-0.05), more preferably 1:(0.01-0.03). This preferred embodiment is more conducive to improving product performance.

[0036] The present invention has no particular limitation on the source of the conductive carbon black. The conductive carbon black can be purchased commercially or prepared by any existing preparation method, as long as the mass content of the metal element is not greater than 10 ppm. It is further preferred that the mass content of the Fe element in the conductive carbon black is not greater than 5 ppm.

[0037] According to a preferred embodiment of the present invention, the mass content of metal elements in the conductive carbon black is not more than 5 ppm, more preferably not more than 2 ppm, further preferably, the mass content of Fe element in the conductive carbon black is not more than 2 ppm, more preferably, the mass content of Fe element is not more than 1 ppm, and the total mass content of other metal elements is less than 1 ppm.

[0038] In the present invention, the metal element content of the conductive carbon black is measured by inductively coupled plasma atomic emission spectrometry.

[0039] The inventors of the present invention have discovered that controlling the amount of Fe by controlling the metal elements in the conductive carbon black is more conducive to improving the anti-yellowing effect of the semi-conductive shielding material.

[0040] According to a preferred embodiment of the present invention, the conductive carbon black has an oil absorption value of 90-350 mL / 100g, for example, 90 mL / 100g, 100 mL / 100g, 110 mL / 100g, 120 mL / 100g, 140 mL / 100g, 160 mL / 100g, 180 mL / 100g, 200 mL / 100g, 220 mL / 100g, 250 mL / 100g, 270 mL / 100g, 300 mL / 100g, or a range consisting of any two values, more preferably 90-200 mL / 100g. This preferred range of oil absorption values ​​is more conducive to the dispersion of the conductive carbon black in the resin system.

[0041] In the present invention, the oil absorption value of the conductive carbon black is measured by a DBP adsorption method.

[0042] According to a preferred embodiment of the present invention, the ash content of the conductive carbon black is ≤0.01%. Using this preferred embodiment and using high-purity carbon black is more conducive to the dispersion of carbon black in the resin system.

[0043] In the present invention, the ash content of the conductive carbon black is measured by a thermogravimetric method.

[0044] The composition of the present invention may optionally contain various additives required to improve / adapt its performance requirements, including but not limited to lubricating dispersants.

[0045] According to the present invention, preferably, the composition further comprises a lubricating dispersant. Further preferably, the mass ratio of the resin to the lubricating dispersant is 1:(0.05-5), for example, 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.3, 1:0.5, 1:1, 1:1.3, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5 or a range consisting of any two ratios.

[0046] The present invention has a wide range of choices for the type of lubricating dispersant, as long as it can improve the dispersibility and lubricity of the material. Preferably, the lubricating dispersant is selected from at least one of polyethylene wax, oxidized polyethylene wax and ethylene bisstearamide.

[0047] According to a preferred embodiment of the present invention, the composition comprises, by mass, 80-100 parts of resin, 35-80 parts of conductive carbon black, 0.2-5 parts in total of the first antioxidant and the second antioxidant, 1-8 parts of lubricating dispersant, and 1-4 parts of crosslinking agent.

[0048] In the present invention, the first antioxidant, the second antioxidant, the lubricating dispersant and the cross-linking agent can all be commercially available.

[0049] The second aspect of the present invention provides a method for preparing the composition according to the first aspect, wherein the method comprises the following steps:

[0050] S1, extruding and granulating the resin, conductive carbon black, the first antioxidant, the second antioxidant, and optionally a lubricating dispersant to obtain pellets;

[0051] S2. Mixing the pellets with a cross-linking agent to obtain the composition.

[0052] In the method provided by the present invention, the selection and dosage range of each raw material are the same as those described in the first aspect and will not be repeated here.

[0053] In the method provided by the present invention, "optionally" means that a lubricating dispersant may be added or not, but preferably is added.

[0054] The present invention has no particular limitation on the extrusion granulation method, but it is preferably carried out in a reciprocating single screw.

[0055] According to a preferred embodiment of the present invention, the temperature of the extrusion granulation in step S1 is 100-180°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or a range consisting of any two values. In the present invention, there is no particular limitation on the specific operation of extrusion granulation and it can be performed according to conventional operations in the art, for example, extrusion can be performed sequentially at different temperatures (in an increasing trend).

[0056] According to a preferred embodiment of the present invention, the mixing temperature in step S2 is 50-65°C, preferably 50-60°C.

[0057] The third aspect of the present invention provides use of the composition described in the first aspect or the composition prepared by the preparation method described in the second aspect in a semiconductive shielding material.

[0058] The composition provided by the present invention can be used as a semi-conductive shielding material directly or after being processed.

[0059] A fourth aspect of the present invention provides use of the composition described in the first aspect or the composition prepared by the preparation method described in the second aspect in preparing a power cable.

[0060] The present invention innovatively prepares a semi-conductive shielding material by using conductive carbon black with a low metal content and a resin, so that the semi-conductive shielding material has a preliminary effect of resisting yellowing of insulation. At the same time, a compound antioxidant is added to the formula system of the present invention. The use of a high-efficiency antioxidant combination allows the prepared cable to withstand high temperatures exceeding 300°C during the vulcanization process, thereby ensuring that the composition of the present invention has excellent anti-yellowing properties as a semi-conductive shielding material. Specifically, after the cable is extruded and vulcanized, the yellow coefficient of the insulation layer in contact with the outer shield is ≤4, preferably ≤3, indicating that the material of the present invention has excellent anti-yellowing effect during the cable processing process; in addition, the average breakdown strength of the insulation layer in contact with the outer shield after slicing is increased by more than 10%, indicating that the semi-conductive shielding material of the present invention improves the electrical strength of the insulation layer in contact with it; in addition, the semi-conductive shielding material of the present invention also has a low volume resistivity and good mechanical properties, etc., and can be used for the preparation of power cables with stable quality.

[0061] In a preferred embodiment of the present invention, the power cable is an AC cable.

[0062] The present invention will be described in detail below through examples.

[0063] In the following examples, ethylene butyl acrylate copolymer has a melt index of 7 g / 10 min at 190°C and a butyl acrylate content of 17% by weight. It is purchased from Arkema, France, and is designated 17BA07. Ethylene vinyl acetate copolymer has a melt index of 20 g / 10 min at 190°C and a vinyl acetate content of 20% by weight. It is purchased from Arkema, France, and is designated 20-20. Ethylene octene copolymer has a melt index of 5 g / 10 min at 190°C and a 2.16 kg load. It is purchased from Dow Chemical, and is designated 8200. Conductive carbon black A was purchased from Denka Japan, and is designated Denkablack. It has a total metal content of 1.7 ppm, including 0.8 ppm iron and 0.9 ppm other metal elements. It has an oil absorption of 160 mL / 100 g and an ash content of ≤0.007%. Conductive carbon black B was purchased from Orion, brand Kappa 100, with a total metal content of 3 ppm, including 1.4 ppm iron and 1.6 ppm other metal elements. It had an oil absorption of 300 mL / 100 g and an ash content of ≤0.003%. Conductive carbon black C was purchased from Yiruishi, brand 260G, with a total metal content of 9 ppm, including 5 ppm iron and 4 ppm other metal elements. It had an oil absorption of 190 mL / 100 g and an ash content of ≤0.01%.

[0064] Example 1

[0065] This embodiment provides a semi-conductive shielding material that resists yellowing of insulation. The raw material composition of the semi-conductive shielding material includes, by mass, 100 parts of ethylene butyl acrylate copolymer, 65 parts of conductive carbon black A, 0.8 parts of 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-mesitylene (antioxidant 330, a first antioxidant), 1 part of bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate (antioxidant RC PEP 36, a second antioxidant), 1.2 parts of ethylene bisstearamide (lubricating dispersant), and 1.8 parts of di-tert-butyl peroxide isopropyl benzene (crosslinking agent).

[0066] The method for preparing the insulating yellowing resistant semi-conductive shielding material comprises the following steps:

[0067] S1. Add all raw materials except the cross-linking agent into a reciprocating single screw according to the formula ratio and extrude and granulate to prepare a premix; wherein the extrusion temperatures of the extrusion granulation are 100, 130, 145, and 150° C., respectively;

[0068] S2. Mixing the premix obtained in step S1 with a cross-linking agent according to a formula ratio to prepare the anti-yellowing semi-conductive shielding material; wherein the mixing temperature is 60°C.

[0069] Example 2

[0070] This embodiment provides a semi-conductive shielding material that resists yellowing of insulation. The raw material composition of the semi-conductive shielding material includes, by mass, 80 parts of ethylene butyl acrylate copolymer, 35 parts of conductive carbon black A, 0.5 parts of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid (antioxidant 3114, a first antioxidant), 0.3 parts of bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate (antioxidant RC PEP 36, a second antioxidant), 1 part of ethylene bisstearamide (lubricating dispersant), and 1 part of di-tert-butyl peroxide isocyanuric acid (crosslinking agent).

[0071] The method for preparing the insulating yellowing resistant semi-conductive shielding material comprises the following steps:

[0072] S1. Add all raw materials except the cross-linking agent into a reciprocating single screw according to the formula ratio and extrude and granulate to prepare a premix; wherein the extrusion temperatures of the extrusion granulation are 100, 130, 145, and 150° C., respectively;

[0073] S2. Mixing the premix obtained in step S1 with a cross-linking agent according to a formula ratio to prepare the anti-yellowing semi-conductive shielding material; wherein the mixing temperature is 60°C.

[0074] Example 3

[0075] This embodiment provides an insulating yellowing resistant semi-conductive shielding material. The raw material composition of the semi-conductive shielding material comprises, by weight, 100 parts of ethylene butyl acrylate copolymer, 80 parts of conductive carbon black A, 0.5 parts of 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene (antioxidant 330, first antioxidant), 0.5 parts of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanuric acid (antioxidant 3114, first antioxidant), 0.5 parts of bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate (antioxidant RC PEP), and 0.5 parts of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanuric acid (antioxidant 3114, first antioxidant). 36, second antioxidant) 0.8 parts, pentaerythritol tetrakis (3-laurylthiopropionate) (antioxidant 412S, second antioxidant) 0.4 parts, ethylene bisstearamide (lubricating dispersant) 2 parts, di-tert-butyl peroxide isopropyl benzene (crosslinking agent) 2 parts.

[0076] The method for preparing the insulating yellowing resistant semi-conductive shielding material comprises the following steps:

[0077] S1. Add all raw materials except the cross-linking agent into a reciprocating single screw according to the formula ratio and extrude and granulate to prepare a premix; wherein the extrusion temperatures of the extrusion granulation are 100, 130, 145, and 150° C., respectively;

[0078] S2. Mixing the premix obtained in step S1 with a cross-linking agent according to a formula ratio to prepare the anti-yellowing semi-conductive shielding material; wherein the mixing temperature is 60°C.

[0079] Example 4

[0080] This embodiment provides a semi-conductive shielding material that resists yellowing of insulation. The raw material composition of the semi-conductive shielding material includes, by weight, 80 parts of ethylene butyl acrylate copolymer, 80 parts of conductive carbon black A, 1 part of antioxidant 330, 0.6 part of antioxidant 412S, 4 parts of ethylene bisstearamide (lubricating dispersant), and 1 part of di-tert-butyl peroxide isopropyl benzene (crosslinking agent).

[0081] The method for preparing the insulating yellowing resistant semi-conductive shielding material comprises the following steps:

[0082] S1. Add all raw materials except the cross-linking agent into a reciprocating single screw according to the formula ratio and extrude and granulate to prepare a premix; wherein the extrusion temperatures of the extrusion granulation are 100, 130, 145, and 150° C., respectively.

[0083] S2. Mixing the premix obtained in step S1 with a cross-linking agent according to a formula ratio to prepare the anti-yellowing semi-conductive shielding material; wherein the mixing temperature is 60°C.

[0084] Example 5

[0085] This embodiment provides a semi-conductive shielding material that resists yellowing of insulation. The raw material composition of the semi-conductive shielding material includes, by weight, 100 parts of ethylene vinyl acetate copolymer, 65 parts of conductive carbon black A, 0.8 parts of 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-mesitylene (antioxidant 330, a first antioxidant), 1 part of bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate (antioxidant RC PEP 36, a second antioxidant), 1.2 parts of ethylene bisstearamide (lubricating dispersant), and 1.8 parts of di-tert-butyl peroxide isopropyl benzene (crosslinking agent).

[0086] The method for preparing the insulating yellowing resistant semi-conductive shielding material comprises the following steps:

[0087] S1. Add all raw materials except the cross-linking agent into a reciprocating single screw according to the formula ratio and extrude and granulate to prepare a premix; wherein the extrusion temperatures of the extrusion granulation are 100, 130, 145, and 150° C., respectively;

[0088] S2. Mixing the premix obtained in step S1 with a cross-linking agent according to a formula ratio to prepare the anti-yellowing semi-conductive shielding material; wherein the mixing temperature is 60°C.

[0089] Example 6

[0090] This embodiment provides a semi-conductive shielding material that resists yellowing of insulation. The raw material composition of the semi-conductive shielding material includes, by mass, 100 parts of ethylene octene copolymer, 65 parts of conductive carbon black A, 0.8 parts of 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-mesitylene (antioxidant 330, a first antioxidant), 1 part of bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate (antioxidant RC PEP 36, a second antioxidant), 1.2 parts of ethylene bisstearamide (lubricating dispersant), and 1.8 parts of di-tert-butyl peroxide isopropyl benzene (crosslinking agent).

[0091] The method for preparing the insulating yellowing resistant semi-conductive shielding material comprises the following steps:

[0092] S1. Add all raw materials except the cross-linking agent into a reciprocating single screw according to the formula ratio and extrude and granulate to prepare a premix; wherein the extrusion temperatures of the extrusion granulation are 100, 130, 145, and 150° C., respectively;

[0093] S2. Mixing the premix obtained in step S1 with a cross-linking agent according to a formula ratio to prepare the anti-yellowing semi-conductive shielding material; wherein the mixing temperature is 60°C.

[0094] Example 7

[0095] The method of Example 2 was followed, except that conductive carbon black A was replaced with conductive carbon black B of equal mass.

[0096] Example 8

[0097] The method of Example 2 was followed, except that conductive carbon black A was replaced with conductive carbon black C of equal mass.

[0098] Comparative Example 1

[0099] The method is the same as Example 1, except that high-purity conductive carbon black is not used and ordinary conductive carbon black is used instead. The conductive carbon black brand is VXC68, purchased from Cabot, with a total metal element content of 26 ppm, including 8 ppm of iron and 18 ppm of other metal elements. The oil absorption value is 123 mL / 100 g and the ash content is ≤0.2%.

[0100] Comparative Example 2

[0101] According to Example 1, the difference is that the raw material composition of the semi-conductive shielding material includes: 100 parts of ethylene butyl acrylate copolymer, 65 parts of conductive carbon black, 1.8 parts of 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene (antioxidant 330, first antioxidant), 1.2 parts of ethylene bisstearamide (lubricating dispersant), and 1.8 parts of di-tert-butyl peroxide isopropyl benzene (cross-linking agent).

[0102] Comparative Example 3

[0103] The method is as in Example 1, except that the raw material composition of the semiconductive shielding material includes: 100 parts of ethylene butyl acrylate copolymer, 65 parts of conductive carbon black, 0.8 parts of antioxidant 1010 (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 1 part of antioxidant DLTP (dilauryl thiodipropionate), 1.2 parts of ethylene bisstearamide (lubricating dispersant), and 1.8 parts of di-tert-butyl peroxide isopropyl benzene (crosslinking agent).

[0104] The insulation yellowing resistance semi-conductive shielding materials prepared in the above examples and comparative examples were subjected to the following performance tests, and the specific results are shown in Table 1.

[0105] Among them, the test standard for tensile strength is GB / T1040.3-2006;

[0106] The test standard for elongation at break is GB / T1040.3-2006;

[0107] The test standard for volume resistivity at 20°C is GB / T3048.3-2007;

[0108] The test standard for volume resistivity at 90°C is GB / T3048.3-2007;

[0109] The test standard for impact brittle temperature is GB / T5470-2008;

[0110] The test standard for thermal aging test (130℃×168h) is GB / T2951.12-2008;

[0111] The test standard for tensile strength change rate is GB / T1040.3-2006;

[0112] The test standard for the rate of change of elongation at break is GB / T1040.3-2006;

[0113] The test standard for the yellow coefficient of the insulation layer at the contact point between the outer screen and the insulation is GB / T 39822-2021;

[0114] The test standard for the breakdown strength of the insulation layer at the contact point between the outer screen and the insulation is GB / T 1408.1-2016.

[0115] Table 1

[0116]

[0117] Table 1

[0118]

[0119] It can be seen from the results in the above table that the composition provided by the present invention has excellent resistance to yellowing of insulation and improved insulation breakdown strength when applied to semi-conductive shielding materials.

[0120] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A composition, characterized in that The composition comprises: resin, conductive carbon black, a first antioxidant, a second antioxidant and a crosslinking agent; Wherein, the mass content of metal elements in the conductive carbon black is not more than 10ppm; the mass content of Fe elements in the conductive carbon black is not more than 5ppm; Wherein, the first antioxidant is 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-mesitylene and / or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanuric acid; Wherein, the second antioxidant is bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate and / or pentaerythritol tetrakis(3-laurylthiopropionate); The resin is selected from at least one of ethylene butyl acrylate copolymer, ethylene vinyl acetate copolymer and ethylene octene copolymer; The mass ratio of the resin to the conductive carbon black is 1:0.35-0.

9.

2. The composition according to claim 1, wherein The mass ratio of the resin to the cross-linking agent is 1: (0.01-0.05); and / or, the weight ratio of the resin to the total amount of the first antioxidant and the second antioxidant is 1:0.001-0.1; And / or, the mass ratio of the first antioxidant to the second antioxidant is 1:(0.2-5).

3. The composition according to claim 1, wherein The mass ratio of the resin to the conductive carbon black is 1:0.45-0.8; and / or, the mass ratio of the resin to the cross-linking agent is 1:(0.01-0.03); and / or, the weight ratio of the resin to the total amount of the first antioxidant and the second antioxidant is 1:0.005-0.05; And / or, the mass ratio of the first antioxidant to the second antioxidant is 1:(0.5-2).

4. The composition according to claim 1, wherein The cross-linking agent is selected from di-tert-butylcumene peroxide and / or dicumyl peroxide.

5. The composition according to claim 1, wherein The ethylene butyl acrylate copolymer has a melt index of 6-25 g / 10 min at 190° C. and a load of 2.16 kg, and a butyl acrylate content of 10-40% by mass; The ethylene vinyl acetate copolymer has a melt index of 2.5-25 g / 10 min at 190° C. and a load of 2.16 kg, and a vinyl acetate content of 12-33% by mass; The melt index of the ethylene octene copolymer at 190° C. and under a load of 2.16 kg is 0.5-15 g / 10 min.

6. The composition according to claim 1, wherein The mass content of the metal element in the conductive carbon black is not more than 5ppm; And / or, the mass content of Fe element in the conductive carbon black is not greater than 2 ppm; And / or, the conductive carbon black has an oil absorption value of 90-350 mL / 100 g; And / or, the ash mass content of the conductive carbon black is ≤0.01%.

7. The composition according to any one of claims 1 to 6, wherein The composition also includes a lubricating dispersant; The mass ratio of the resin to the lubricating dispersant is 1:(0.05-5).

8. The composition according to claim 7, wherein The lubricating dispersant is selected from at least one of polyethylene wax, oxidized polyethylene wax and ethylene bisstearamide.

9. The method for preparing the composition according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: S1, extruding and granulating the resin, conductive carbon black, the first antioxidant, the second antioxidant, and optionally a lubricating dispersant to obtain pellets; S2. Mixing the pellets with a cross-linking agent to obtain the composition.

10. The method according to claim 9, wherein: The temperature of the extrusion granulation in step S1 is 100-180°C; And / or, the mixing temperature in step S2 is 50-65°C.

11. Use of the composition according to any one of claims 1 to 8 or the composition prepared by the preparation method according to claim 9 or 10 in semiconductive shielding materials.

12. Use of the composition according to any one of claims 1 to 8 or the composition prepared by the preparation method according to claim 9 or 10 in the preparation of a power cable.

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