Yellowing-resistant cross-linked polyethylene insulation material, preparation method, application and cable thereof

Abstract

The present application provides a yellowing-resistant cross-linked polyethylene insulation material and its preparation method, application and cable, wherein the yellowing-resistant cross-linked polyethylene insulation material comprises polyethylene, a primary antioxidant, a carbon radical scavenger, a cross-linking agent, a lubricant and an optional auxiliary antioxidant; the primary antioxidant comprises one or more of hindered phenol antioxidants; the auxiliary antioxidant comprises one or more of thioester antioxidants and phosphite antioxidants; the carbon radical scavenger comprises one or more of hindered amines, hydroxylamines, bisphenol monoacrylates, benzofuranones and ortho-allyl substituted phenols; the mass ratio of the primary antioxidant, the auxiliary antioxidant and the carbon radical scavenger is (0.1-1.5):(0-1):(0.1-0.5). The antioxidant system composed of the primary antioxidant or the primary antioxidant and the auxiliary antioxidant can inhibit the thermal oxidative degradation of polyethylene during processing; under the action of the carbon radical scavenger, the generation of chromogenic substances can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of insulating materials, and in particular to a yellowing-resistant cross-linked polyethylene insulating material, a preparation method thereof, an application thereof, and a cable. Background Art

[0002] In recent years, with the expansion and upgrading of urban power distribution networks, the rapid growth of renewable energy such as offshore wind power, and the increasing demand for long-distance power transmission, the application prospects of high-voltage AC and DC power transmission technologies have become increasingly broad. Among them, cables are the core equipment for high-voltage power transmission, and the performance of their insulation materials has a significant impact on the efficiency and effectiveness of power transmission.

[0003] With the continuous development of science and technology, cross-linked polyethylene (XLPE) materials have been widely used in high-voltage cables due to their excellent insulation and mechanical properties. Cross-linked polyethylene is usually a thermosetting material with a three-dimensional network structure formed by cross-linking polyethylene under the action of a cross-linking agent. As an insulating layer, it can effectively prevent the passage of current and withstand high voltage without breakdown, thereby ensuring the stable transmission of electricity. Therefore, the quality of cross-linked polyethylene often determines the performance and grade of high-voltage AC and DC cables.

[0004] At present, the high-voltage insulation materials of 220 kV and above used in domestic projects are either of high cost or low grade, and are prone to yellowing during the cable extrusion and vulcanization process, which not only affects the appearance of the wire core, but also affects the insulation performance of the wire core to a certain extent, reducing its service life. Summary of the invention

[0005] Based on this, the present application provides a yellowing-resistant cross-linked polyethylene insulation material and its preparation method, application and cable, so as to reduce the occurrence of yellowing during cable extrusion and vulcanization, improve the appearance and insulation performance of the wire core, and extend the service life of the battery core.

[0006] The first aspect of the present application provides a yellowing-resistant cross-linked polyethylene insulation material, comprising polyethylene, a primary antioxidant, a carbon free radical scavenger, a cross-linking agent and a lubricant; optionally, further comprising an auxiliary antioxidant;

[0007] Wherein, the primary antioxidant includes one or more hindered phenol antioxidants;

[0008] The auxiliary antioxidant includes one or more of a thioester antioxidant and a phosphite antioxidant;

[0009] The carbon free radical scavenger includes one or more of a hindered amine carbon free radical scavenger, a hydroxylamine carbon free radical scavenger, a bisphenol monoacrylate carbon free radical scavenger, a benzofuranone carbon free radical scavenger and an ortho-allyl substituted phenol carbon free radical scavenger;

[0010] The mass ratio of the primary antioxidant, the auxiliary antioxidant and the carbon radical scavenger is (0.1-1.5):(0-1):(0.1-0.5).

[0011] In some embodiments, the following components are included in parts by weight:

[0012] Polyethylene 100 parts,

[0013] Main antioxidant 0.1-1.5 parts,

[0014] Auxiliary antioxidant 0-1.0 parts,

[0015] Cross-linking agent 0.8-2.5 parts,

[0016] 0.1-0.5 parts of carbon radical scavenger, and

[0017] Lubricant 0.1 part -1.0 part.

[0018] In some embodiments, the yellowing-resistant cross-linked polyethylene insulation material has at least one of the following characteristics (1)-(4):

[0019] (1) The weight percentage of the primary antioxidant contained in the yellowing-resistant cross-linked polyethylene insulation material is 0.1 part to 1.0 part;

[0020] (2) The weight percentage of the auxiliary antioxidant contained in the yellowing-resistant cross-linked polyethylene insulation material is 0.1 part to 1.0 part;

[0021] (3) The carbon radical scavenger contained in the yellowing-resistant cross-linked polyethylene insulation material has an amount of 0.2 to 0.4 parts by weight;

[0022] (4) In parts by weight, the cross-linking agent contained in the yellowing-resistant cross-linked polyethylene insulation material has an amount of 1.0 parts by weight to 2.0 parts by weight.

[0023] In some embodiments, the carbon radical scavenger includes one or more of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2,2,6,6-tetramethyl-4-piperidinyl ester, pentamethylpiperidinol, isopropanolamine, ethanolamine, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 2'2-oxalylamino-bis-[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, dimethylbenzene dibutylbenzofuranone, 2,4-diphenyl-4-methyl-1-pentene and o-allylphenol.

[0024] In some embodiments, the primary antioxidant includes one or more of 2,6-di-tert-butyl-4-methylphenol, 4,6-bis(octylthiomethyl)-o-cresol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 2,2'-thioethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,5-di-tert-butyl-4-hydroxyphenylpropionate and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0025] In some embodiments, the auxiliary antioxidant includes one or more of didodecanol thiodipropionate, didedecyl thiodipropionate, pentaerythritol tetrakis(3-laurylthiopropionate), tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol bisdiphosphite and tris(nonylphenol)phosphite.

[0026] In some embodiments, the density of the polyethylene is 0.90 mol / cm 3 -0.98 mol / cm 3 .

[0027] In some embodiments, the polyethylene has a melt index of 1.6 g / 10 min to 2.5 g / 10 min.

[0028] In some embodiments, the cross-linking agent includes one or more of peroxides.

[0029] In some embodiments, the crosslinking agent includes one or more of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, dicumyl peroxide, and di-tert-butyl peroxide.

[0030] In some embodiments, the lubricant includes one or more of paraffin wax, stearyl alcohol, palmitol, polyethylene wax, and polyethylene glycol ester.

[0031] In some embodiments, compared with conventional insulating materials used in the cable field, the yellowing index of the yellowing-resistant cross-linked polyethylene insulating material is reduced and the electrical performance is improved without affecting the mechanical properties of the yellowing-resistant cross-linked polyethylene insulating material.

[0032] In some embodiments, the yellowing-resistant cross-linked polyethylene insulation material has at least one of the following characteristics (1)-(6):

[0033] (1) The tensile strength of the yellowing-resistant cross-linked polyethylene insulation material is 21.5 MPa-26 MPa;

[0034] (2) The elongation at break of the yellowing-resistant cross-linked polyethylene insulation material is 510%-575%;

[0035] (3) The thermal elongation of the yellowing-resistant cross-linked polyethylene insulation material is 45%-60%;

[0036] (4) The breakdown strength of the yellowing-resistant cross-linked polyethylene insulation material is 98.5 KV·mm -1 -102 KV mm -1 ;

[0037] (5) The dielectric constant of the yellowing-resistant cross-linked polyethylene insulation material is 2.0 F·m -1 -2.21 F·m -1 ;

[0038] (6) The yellowness index of the yellowing-resistant cross-linked polyethylene insulation material is -0.08~0.38.

[0039] The second aspect of the present application provides a method for preparing the yellowing-resistant cross-linked polyethylene insulation material of the first aspect of the present application, comprising the following steps:

[0040] Mixing a primary antioxidant, polyethylene, a carbon free radical scavenger, a lubricant and an optional auxiliary antioxidant to prepare a mixed material;

[0041] Extruding and granulating the mixed material to prepare an intermediate material;

[0042] The intermediate material is mixed with a cross-linking agent and then subjected to post-absorption treatment to prepare the yellowing-resistant cross-linked polyethylene insulating material.

[0043] In some embodiments, the preparation method includes at least one of the following conditions:

[0044] (1) The mixing temperature is 40° C., the mixing time is 15 min to 30 min, and the mixing method is stirring;

[0045] (2) The extrusion is performed using a twin-screw extruder, the extrusion temperature is 115° C.-180° C., and the screw speed is 100 r / min-250 r / min;

[0046] (3) The post-absorption treatment temperature is 60°C-80°C and the time is 12h-20h;

[0047] (4) After the extrusion, a cooling step is also included, and the cooling method is water cooling.

[0048] The third aspect of the present application provides an application of the yellowing-resistant cross-linked polyethylene insulation material of the first aspect of the present application or the yellowing-resistant cross-linked polyethylene insulation material prepared by the preparation method of the second aspect of the present application in preparing cables.

[0049] The fourth aspect of the present application provides a cable, the raw materials of which include the yellowing-resistant cross-linked polyethylene insulation material of the first aspect of the present application or the yellowing-resistant cross-linked polyethylene insulation material prepared by the preparation method of the second aspect of the present application.

[0050] In some embodiments, the cable is a submarine cable;

[0051] In some embodiments, the cable has a carrying voltage of 500 kV and below.

[0052] The yellowing-resistant cross-linked polyethylene insulation material provided above includes a primary antioxidant, a carbon radical scavenger and an optional auxiliary antioxidant; the antioxidant system composed of the primary antioxidant or the primary antioxidant and the auxiliary antioxidant can inhibit the thermal oxidative degradation of polyethylene during processing; at the same time, under the action of the carbon radical scavenger, the chain reaction between the cross-linking agent and the antioxidant by-products is further hindered, reducing the generation of color-forming substances, so that the insulation material has better yellowing resistance and a lower yellow index. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application and to more completely understand the present application and its beneficial effects, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0054] Figure 1 A process flow chart for preparing yellowing-resistant cross-linked polyethylene insulation material is provided for one embodiment of the present application. DETAILED DESCRIPTION

[0055] For ease of understanding of the present invention, the application will be described more fully below with reference to relevant embodiments. The following provides preferred embodiments of the application. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the application more thorough and comprehensive.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0057] The terms "and / or", "or / and", and "and / or" used herein include any one of two or more related listed items, and also include any and all combinations of the related listed items, wherein the any and all combinations include any combination of two related listed items, any more related listed items, or all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or", "or / and", and "and / or", it should be understood that in the present application, the technical solution undoubtedly includes technical solutions connected by "logical and", and also undoubtedly includes technical solutions connected by "logical or".

[0058] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0059] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0060] Only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0061] The temperature parameters in this application, unless otherwise specified, allow both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0062] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0063] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0064] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0065] In the description of the application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0066] If there is no special description, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. If there is no special description, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0067] If there is no special explanation, all the steps of the present application can be performed sequentially or randomly, preferably sequentially.

[0068] At present, the voltage level of domestic insulation materials is low, and they are prone to yellowing during the vulcanization process of the cable extruder, which not only affects the appearance of the wire core, but also affects the insulation performance of the wire core to a certain extent, reducing its service life. Studies have found that the yellowing of insulation materials mainly comes from the reaction byproducts of antioxidants or cross-linking agents. Since the byproducts contain chromophores, the cable insulation layer turns yellow and discolored. In related technologies, the method of inhibiting the yellowing of insulation materials is usually to change the type of antioxidant or to use a combination of main and auxiliary antioxidants, but the effect is not ideal.

[0069] Based on this, the present application adds a carbon radical scavenger when preparing the insulating material. The carbon radical scavenger and the antioxidant are used in combination. The carbon radical scavenger can further hinder the chain reaction between the crosslinking agent and the antioxidant by-products, and reduce the production of color-forming substances.

[0070] One or more embodiments of the present application provide a yellowing-resistant cross-linked polyethylene insulation material, comprising polyethylene, a primary antioxidant, a carbon radical scavenger, a cross-linking agent, a lubricant, and an optional auxiliary antioxidant; wherein the primary antioxidant comprises one or more of hindered phenol antioxidants; the auxiliary antioxidant comprises one or more of thioester antioxidants and phosphite antioxidants; the carbon radical scavenger comprises one or more of hindered amine carbon radical scavengers, hydroxylamine carbon radical scavengers, bisphenol monoacrylate carbon radical scavengers, benzofuranone carbon radical scavengers, and ortho-allyl substituted phenol carbon radical scavengers; the mass ratio of the primary antioxidant, the auxiliary antioxidant, and the carbon radical scavenger is (0.1-1.5):(0-1):(0.1-0.5).

[0071] It should be noted that the “optional auxiliary antioxidant” mentioned above means that the yellowing-resistant cross-linked polyethylene insulation material may contain an auxiliary antioxidant or may not contain an auxiliary antioxidant, and the selection can be made according to actual needs.

[0072] It can be understood that the yellowing-resistant cross-linked polyethylene insulation material provided above includes a primary antioxidant, a carbon radical scavenger and an optional auxiliary antioxidant; the antioxidant system composed of the primary antioxidant or the primary antioxidant and the auxiliary antioxidant can inhibit the thermal oxidative degradation of polyethylene during processing; at the same time, under the action of the carbon radical scavenger, the chain reaction between the cross-linking agent and the antioxidant by-products is further hindered, reducing the production of color-forming substances, so that the insulation material has better yellowing resistance and a lower yellow index.

[0073] As a non-limiting example, the mass ratio of the primary antioxidant, the auxiliary antioxidant and the carbon radical scavenger is (0.1-1.5):(0.1-1):(0.1-0.5). This is conducive to further improving the yellowing resistance of the insulating material. Further optionally, the mass ratio of the primary antioxidant, the auxiliary antioxidant and the carbon radical scavenger is (0.1-1):(0.1-1):(0.2-0.4).

[0074] In some embodiments, the following components are included in parts by weight:

[0075] Polyethylene 100 parts,

[0076] Main antioxidant 0.1-1.5 parts,

[0077] Auxiliary antioxidant 0-1.0 parts,

[0078] Cross-linking agent 0.8-2.5 parts,

[0079] 0.1-0.5 parts of carbon radical scavenger, and

[0080] Lubricant 0.1 part -1.0 part.

[0081] As a non-limiting example, based on 100 parts by weight of polyethylene, the weight portion of the main antioxidant contained in the yellowing resistant cross-linked polyethylene insulation material can be but is not limited to 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts or ranges between any two of the above weight portions, etc.

[0082] Based on 100 parts by weight of polyethylene, the weight proportion of the auxiliary antioxidant contained in the yellowing-resistant cross-linked polyethylene insulation material can be but is not limited to 0 parts, 0.05 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, 1.0 parts or ranges between any two of the above weight proportions, etc.

[0083] It should be noted that when the weight portion of the auxiliary antioxidant is 0 parts, it indicates that the yellowing-resistant cross-linked polyethylene insulation material does not contain the auxiliary antioxidant.

[0084] Based on 100 parts by weight of polyethylene, the weight portion of the carbon radical scavenger contained in the yellowing-resistant cross-linked polyethylene insulation material can be but is not limited to 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts or a range between any two of the above weight portions, etc.

[0085] Based on 100 parts by weight of polyethylene, the weight proportion of the crosslinking agent contained in the yellowing-resistant cross-linked polyethylene insulation material can be but is not limited to 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.0 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts or the range between any two of the above weight proportions, etc.

[0086] Based on 100 parts by weight of polyethylene, the weight portion of the lubricant contained in the yellowing-resistant cross-linked polyethylene insulation material can be but is not limited to 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts or a range between any two of the above weight portions.

[0087] When the amounts of polyethylene, primary antioxidant, auxiliary antioxidant, carbon radical scavenger, cross-linking agent and lubricant in the yellowing resistant cross-linked polyethylene insulation material are respectively within the above ranges, the electrical properties of the insulation material can meet the use requirements, and the cable can have a better wire core appearance after extrusion, achieving performance quality similar to that of foreign insulation materials of the same grade.

[0088] In some optional embodiments, the weight percentage of the primary antioxidant contained in the yellowing resistant cross-linked polyethylene insulation material is 0.1 part to 1.0 part.

[0089] As a possible implementation, the weight percentage of the auxiliary antioxidant contained in the yellowing-resistant cross-linked polyethylene insulation material is 0.1 part to 1.0 part.

[0090] In some embodiments, the carbon radical scavenger contained in the yellowing-resistant cross-linked polyethylene insulation material has an amount of 0.2 to 0.4 parts by weight.

[0091] In some exemplary embodiments, the cross-linking agent contained in the yellowing-resistant cross-linked polyethylene insulation material has an amount of 1.0 to 2.0 parts by weight.

[0092] In some optional embodiments, the carbon radical scavenger includes one or more of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (hindered amine 770), 2,2,6,6-tetramethyl-4-piperidinyl ester, pentamethylpiperidinol, isopropanolamine, ethanolamine, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 2'2-oxalamido-bis-[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)] propionate, dimethylbenzene dibutylbenzofuranone, 2,4-diphenyl-4-methyl-1-pentene (AMSD) and o-allylphenol.

[0093] As a non-limiting example, 2,2,6,6-tetramethyl-4-piperidinyl esters include 2,2,6,6-tetramethyl-4-piperidinyl stearate (light stabilizer UV-3853).

[0094] In some embodiments, the primary antioxidant includes 2,6-di-tert-butyl-4-methylphenol (antioxidant BHT), 4,6-bis(octylthiomethyl)-o-cresol (antioxidant 1520), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol ester (antioxidant 1076), N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide) (antioxidant 1098), 2,2'-thioethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (antioxidant 1035) , 3,5-di-tert-butyl-4-hydroxyphenylpropionate (Antioxidant 1135) and 4,4'-thiobis(6-tert-butyl-3-methylphenol) (Antioxidant 300) One or more of the group consisting of:

[0095] As a possible embodiment, the auxiliary antioxidant includes one or more of didodecanol thiodipropionate (antioxidant DLTP), didedecyl thiodipropionate (antioxidant DSTP), pentaerythritol tetrakis (3-laurylthiopropionate) (antioxidant 412S), tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), bis(2,4-di-tert-butylphenyl) pentaerythritol bisdiphosphite (antioxidant 626) and tris(nonylphenol) phosphite (antioxidant TNPP).

[0096] In some embodiments, the primary antioxidant is one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester (antioxidant 1010), 2,2'-thioethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1035), 3,5-di-tert-butyl-4-hydroxyphenylpropionate (antioxidant 1135) and 4,4'-thiobis(6-tert-butyl-3-methylphenol) (antioxidant 300), the auxiliary antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168) and bis(2,4-di-tert-butylphenyl) pentaerythritol bis diphosphite (antioxidant 626), and the carbon radical scavenger is o-allylphenol and 2,4-diphenyl-4-methyl-1-pentene (AMSD). When at least one of the above is added, it is beneficial to further improve the yellowing resistance of the insulating material.

[0097] As a non-limiting example, when the mass ratio of the primary antioxidant, the auxiliary antioxidant and the carbon radical scavenger is (0.2-0.5):(0.1-0.3):(0.2-0.4), it is beneficial to further improve the yellowing resistance of the insulating material.

[0098] In some embodiments, the density of polyethylene is 0.90 mol / cm 3-0.98 mol / cm 3 ; For example, it can be but not limited to 0.90 mol / cm 3 , 0.91 mol / cm 3 , 0.92 mol / cm 3 , 0.93 mol / cm 3 , 0.94 mol / cm 3 , 0.95mol / cm 3 , 0.96 mol / cm 3 , 0.97 mol / cm 3 , 0.98 mol / cm 3 Or the range between any two of the above densities, etc.

[0099] As a possible embodiment, the melt index of polyethylene is 1.6g / 10 min-2.5g / 10 min; for example, it can be but not limited to 1.6g / 10 min, 1.7g / 10 min, 1.8g / 10 min, 1.9g / 10 min, 2.0g / 10 min, 2.1g / 10 min, 2.2g / 10 min, 2.3g / 10 min, 2.4g / 10 min, 2.5g / 10 min or the range between any two of the above melt indices, etc.

[0100] When the density and melt index of polyethylene are within the above ranges, they can not only meet the requirements of the processing performance and mechanical properties of the insulation material, but also enable the additive system to exert its best effect.

[0101] In some embodiments, the cross-linking agent includes one or more of peroxides.

[0102] In some exemplary embodiments, the cross-linking agent includes one or more of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DHBP), dicumyl peroxide (DCP), and di-tert-butyl peroxide (DTBP).

[0103] In some embodiments, the lubricant includes one or more of paraffin wax, stearyl alcohol, palmitol, polyethylene wax, and polyethylene glycol ester.

[0104] In the present application, compared with conventional insulating materials used in the cable field, the yellow index of the yellowing-resistant cross-linked polyethylene insulating material is reduced and the electrical performance is improved without affecting the mechanical properties of the yellowing-resistant cross-linked polyethylene insulating material.

[0105] In some embodiments, the tensile strength of the yellowing-resistant cross-linked polyethylene insulation material is 21.5 MPa-26 MPa.

[0106] As a possible implementation, the elongation at break of the yellowing-resistant cross-linked polyethylene insulation material is 510%-575%; optionally 511%-573%.

[0107] It should be noted that the tensile strength and elongation at break mentioned above refer to the test of GB / T 1040.2-2022.

[0108] In some embodiments, the thermal elongation of the yellowing-resistant cross-linked polyethylene insulation material is 45%-60%.

[0109] It should be noted that the thermal elongation mentioned above is tested with reference to GB / T 2951.21-2008.

[0110] As a possible implementation method, the breakdown strength of the yellowing-resistant cross-linked polyethylene insulation material is 98.5 KV·mm -1 -102 KV mm -1 ; Optional: 98.7 KV·mm -1 -102 KV mm -1 .

[0111] It should be noted that the breakdown strength mentioned above is tested using a ball-ball electrode in accordance with GB / T 1408.1-2016. In some embodiments, the dielectric constant of the yellowing-resistant cross-linked polyethylene insulation material is 2.0 F·m -1 -2.21 F·m -1 ; Optional: 2.02 F·m -1 -2.21 F·m -1 ; further optional 2.02 F·m -1 -2.2 F·m -1 .

[0112] As a possible implementation method, the dielectric loss of the yellowing-resistant cross-linked polyethylene insulation material is 0.75×10 -4 -1.05×10 -4 ; Optional: 0.76×10 -4 -1.02×10 -4 .

[0113] It should be noted that the dielectric constant and dielectric loss mentioned above are tested with reference to GB / T 1409-2006.

[0114] In some embodiments, the yellowness index of the yellowing resistant cross-linked polyethylene insulation material is -0.08 to 0.38.

[0115] It should be noted that the yellowness index mentioned in the context is tested in reference to GB / T 39822-2021.

[0116] One or more embodiments of the present application provide a method for preparing a yellowing-resistant cross-linked polyethylene insulation material, which can be used to prepare the above-mentioned yellowing-resistant cross-linked polyethylene insulation material. The preparation method comprises the following steps:

[0117] The main antioxidant, polyethylene, carbon free radical scavenger, lubricant and optional auxiliary antioxidant are mixed to prepare a mixed material; the mixed material is extruded and granulated to prepare an intermediate material; the intermediate material is mixed with a cross-linking agent and then subjected to post-absorption treatment to prepare a yellowing-resistant cross-linked polyethylene insulation material.

[0118] It should be noted that the “optional auxiliary antioxidant” mentioned above means that an auxiliary antioxidant may or may not be added when preparing the yellowing-resistant cross-linked polyethylene insulation material; that is, the prepared yellowing-resistant cross-linked polyethylene insulation material may or may not contain an auxiliary antioxidant, which can be selected according to actual needs.

[0119] It can be understood that the preparation method is simple in process, low in cost, and has good universality, and can be widely used in industrial production.

[0120] As a possible implementation method, when the raw materials for preparing the yellowing-resistant cross-linked polyethylene insulation material do not contain an auxiliary antioxidant, the preparation method comprises the following steps:

[0121] The main antioxidant, polyethylene, carbon free radical scavenger and lubricant are mixed to prepare a mixed material; the mixed material is extruded and granulated to prepare an intermediate material; the intermediate material is mixed with a cross-linking agent and then subjected to post-absorption treatment to prepare a yellowing-resistant cross-linked polyethylene insulation material.

[0122] In some exemplary embodiments, Figure 1 As shown, when the raw materials for preparing the yellowing-resistant cross-linked polyethylene insulation material contain an auxiliary antioxidant, the preparation method comprises the following steps:

[0123] The primary antioxidant and the auxiliary antioxidant are mixed evenly, and then mixed with polyethylene, a carbon free radical scavenger and a lubricant to prepare a mixed material; the mixed material is extruded and granulated to prepare an intermediate material; the intermediate material is mixed with a cross-linking agent and then subjected to post-absorption treatment to prepare a yellowing-resistant cross-linked polyethylene insulation material.

[0124] In some of the embodiments, a high-speed mixer is used to prepare the mixed material.

[0125] In some optional embodiments, the mixing method is stirring mixing.

[0126] In some exemplary embodiments, the mixing temperature is 40°C.

[0127] As an optional embodiment, the mixing time is 15 min-30 min; for example, it can be but not limited to 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, 30 min or a range between any two of the above times.

[0128] When the mixing time is within the above range, it is beneficial for the polyethylene particles and the additive system to be mixed evenly.

[0129] It should be noted that the mixing time can be selected from any time described herein.

[0130] In some embodiments, a twin-screw extruder is used for extrusion, and the extrusion temperature is 115°C-180°C; for example, it can be but is not limited to 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C or a range between any two of the above temperatures.

[0131] As a possible implementation manner, a twin-screw extruder is used for extrusion, and the screw speed of the extrusion is 100r / min-250r / min; for example, it can be but not limited to 100r / min, 110r / min, 120r / min, 130r / min, 140r / min, 150r / min, 160r / min, 170r / min, 180r / min, 190r / min, 200r / min, 210r / min, 220r / min, 230r / min, 240r / min, 250r / min or the range between any two of the above screw speeds, etc.

[0132] It should be noted that the extrusion temperature and the screw speed can be combined in any suitable manner, and both can be selected from any extrusion temperature and screw speed described in this document.

[0133] When the extrusion temperature and the screw speed are respectively within the above ranges, it is beneficial to the extrusion stability of the semi-finished product and the uniform dispersion of the auxiliary agent system.

[0134] In some embodiments, the temperature of the post-absorption treatment is 60°C-80°C; for example, it can be but is not limited to 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C or the range between any two of the above temperatures.

[0135] As a possible implementation manner, the time for post-absorption treatment is 12h-20h; for example, it can be but not limited to 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h or a range between any two of the above times.

[0136] It should be noted that the temperature and time of the post-absorption treatment can be combined in any appropriate manner, and both can be selected from any temperature and time of the post-absorption treatment described in this article.

[0137] In some optional embodiments, a cooling step is further included after extrusion, and the cooling method is water cooling.

[0138] In some embodiments, the temperature control of the twin-screw extruder is 8 stages.

[0139] One or more embodiments of the present application provide a use of the above-mentioned yellowing-resistant cross-linked polyethylene insulation material or the yellowing-resistant cross-linked polyethylene insulation material prepared by the above-mentioned preparation method in the preparation of cables.

[0140] One or more embodiments of the present application provide a cable, the raw materials for preparing the cable include the above-mentioned yellowing-resistant cross-linked polyethylene insulation material or the yellowing-resistant cross-linked polyethylene insulation material prepared by the above-mentioned preparation method.

[0141] In some embodiments, the cable is a submarine cable.

[0142] As a possible implementation, the carrying voltage of the cable is 500 kV or less.

[0143] It should be noted that the “carrying voltage” mentioned in this context refers to the voltage at which the cable can operate safely and stably.

[0144] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods for which specific conditions are not specified in the following embodiments are preferably referred to the guidance given in the present invention, and can also be carried out according to the experimental manual or conventional conditions in the art, or according to the conditions recommended by the manufacturer, or with reference to experimental methods known in the art.

[0145] In the following specific embodiments, the measured parameters of raw material components may have slight deviations within the range of weighing accuracy unless otherwise specified. For temperature and time parameters, acceptable deviations caused by instrument test accuracy or operation accuracy are allowed.

[0146] 1. Preparation of yellowing-resistant cross-linked polyethylene insulation material

[0147] 1. Prescription composition

[0148] The formulation compositions of the embodiments and comparative examples are shown in Table 1.

[0149] Table 1

[0150]

[0151] In Table 1, LDPE stands for low-density polyethylene, with a density of 0.96 mol / cm 3 , the melt index is 1.95g / 10 min.

[0152] The antioxidant BHT is 2,6-di-tert-butyl-4-methylphenol, the antioxidant 1035 is 2,2'-thioethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], the antioxidant 1010 is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], the antioxidant 1076 is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol ester, the antioxidant 1135 is 3,5-di-tert-butyl-4-hydroxyphenyl propionate, the antioxidant 1098 is N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), and the antioxidant 300 is 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0153] Antioxidant 168 is tris(2,4-di-tert-butylphenyl) phosphite, antioxidant DLTP is didodecanol thiodipropionate, antioxidant DSTP is didedecyl thiodipropionate, antioxidant 626 is bis(2,4-di-tert-butylphenyl) pentaerythritol bis(diphosphite), antioxidant 412S is pentaerythritol tetra(3-laurylthiopropionate), and antioxidant TNPP is tris(nonylphenol) phosphite.

[0154] DHBP is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, DCP is diisopropylbenzene peroxide, and DTBP is di-tert-butyl peroxide.

[0155] Hindered amine 770 is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, AMSD is 2,4-diphenyl-4-methyl-1-pentene, and bisphenol B is bis-p-hydroxyphenylbutane.

[0156] 2. Preparation process

[0157] Example 1

[0158] Step 1. The primary antioxidant and the auxiliary antioxidant are mixed evenly, and then placed together with polyethylene, carbon free radical scavenger and lubricant in a high-speed mixer, and stirred at 40 ° C for 20 min;

[0159] Step 2. The uniformly mixed raw materials are added into a twin-screw extruder through a vector weighing feeding system, the screw speed is 190 r / min, and the temperatures of the various zones of the twin-screw body are set to 115°C, 125°C, 140°C, 155°C, 170°C, 180°C, 165°C, and 155°C in sequence, and then granulated and dried to obtain an intermediate material;

[0160] Step 3. Add the cross-linking agent to the intermediate material and perform post-absorption at 70°C. After 20 hours of post-absorption, the yellowing-resistant cross-linked polyethylene insulation material is obtained.

[0161] Example 2

[0162] Step 1. The primary antioxidant and the auxiliary antioxidant are mixed evenly, and then placed together with polyethylene, carbon free radical scavenger and lubricant in a high-speed mixer, and stirred at 40 ° C for 25 min;

[0163] Step 2. The uniformly mixed raw materials are added into a twin-screw extruder through a vector weighing feeding system, the screw speed is 150 r / min, and the temperatures of the various zones of the twin-screw body are set to 120°C, 125°C, 135°C, 145°C, 155°C, 160°C, 160°C, and 155°C in sequence, and then granulated and dried to obtain an intermediate material;

[0164] Step 3. Add the cross-linking agent to the intermediate material and perform post-absorption at 60°C. After 18 hours of post-absorption, the yellowing-resistant cross-linked polyethylene insulation material is obtained.

[0165] Example 3

[0166] Step 1. The primary antioxidant and the auxiliary antioxidant are mixed evenly, and then placed together with polyethylene, carbon free radical scavenger and lubricant in a high-speed mixer, and stirred at 40 ° C for 25 min;

[0167] Step 2. The uniformly mixed raw materials are added into a twin-screw extruder through a vector weighing feeding system, the screw speed is 155 r / min, and the temperatures of the various zones of the twin-screw body are set to 115°C, 120°C, 135°C, 145°C, 155°C, 165°C, 160°C, and 155°C in sequence, and then granulated and dried to obtain an intermediate material;

[0168] Step 3. Add the cross-linking agent to the intermediate material and perform post-absorption at 70°C. After 15 hours of post-absorption, the yellowing-resistant cross-linked polyethylene insulation material is obtained.

[0169] Example 4

[0170] Step 1. The primary antioxidant and the auxiliary antioxidant are mixed evenly, and then placed together with polyethylene, carbon free radical scavenger and lubricant in a high-speed mixer, and stirred at 40 ° C for 30 min;

[0171] Step 2. The uniformly mixed raw materials are added into a twin-screw extruder through a vector weighing feeding system, the screw speed is 150 r / min, and the temperatures of the various zones of the twin-screw body are set to 120°C, 125°C, 135°C, 145°C, 155°C, 160°C, 155°C, and 150°C in sequence, and then granulated and dried to obtain an intermediate material;

[0172] Step 3. Add the cross-linking agent to the intermediate material and perform post-absorption at 60°C. After 18 hours of post-absorption, the yellowing-resistant cross-linked polyethylene insulation material is obtained.

[0173] Example 5

[0174] The stirring time for mixing the materials in step 1 of Example 5 is 15 min; the screw speed during twin-screw extrusion in step S2 is 130 r / min, and the temperatures of each zone of the twin-screw body are set to 120 ℃, 125 ℃, 140 ℃, 155 ℃, 165 ℃, 175 ℃, 165 ℃, and 160 ℃ respectively; the temperature of the post-absorption in step S3 is 65 ℃, and the time is 20 h.

[0175] Example 6

[0176] In Example 6, the stirring time for mixing the materials in step 1 is 20 min; the screw speed during twin-screw extrusion in step S2 is 180 r / min, and the temperatures of each zone of the twin-screw body are set to 120 ℃, 125 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 165 ℃, and 160 ℃ respectively; the temperature of the post-absorption in step S3 is 70 ℃, and the time is 18 h.

[0177] Example 7

[0178] The stirring time for mixing the materials in step 1 of Example 7 is 20 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of each zone of the twin-screw body are set to 120 ℃, 125 ℃, 135 ℃, 145 ℃, 155 ℃, 160 ℃, 150 ℃, and 150 ℃ respectively; the temperature of the post-absorption in step S3 is 65 ℃, and the time is 12 h.

[0179] Example 8

[0180] The stirring time for mixing the materials in step 1 of Example 8 is 30 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of each zone of the twin-screw body are set to 120 ℃, 130 ℃, 140 ℃, 150 ℃, 165 ℃, 180 ℃, 165 ℃, and 155 ℃ respectively; the temperature of the post-absorption in step S3 is 70 ℃, and the time is 18 h.

[0181] Example 9

[0182] In Example 9, the stirring time for mixing the materials in step 1 is 30 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of each zone of the twin-screw body are set to 120 ℃, 125 ℃, 135 ℃, 145 ℃, 160 ℃, 175 ℃, 165 ℃, and 155 ℃ respectively; the temperature of the post-absorption in step S3 is 70 ℃, and the time is 15 h.

[0183] Example 10

[0184] The stirring time for mixing the materials in step 1 of Example 10 is 20 min; the screw speed during twin-screw extrusion in step S2 is 180 r / min, and the temperatures of each zone of the twin-screw body are set to 115 ℃, 125 ℃, 135 ℃, 140 ℃, 150 ℃, 165 ℃, 160 ℃, and 155 ℃ respectively; the temperature of the post-absorption in step S3 is 70 ℃, and the time is 15 h.

[0185] Embodiment 11

[0186] The stirring time for mixing the materials in step 1 of Example 11 is 20 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of each zone of the twin-screw body are set to 120°C, 130°C, 145°C, 155°C, 170°C, 180°C, 165°C, and 160°C respectively; the temperature of the post-absorption in step S3 is 65°C, and the time is 20 h.

[0187] Example 12

[0188] The stirring time for mixing the materials in step 1 of Example 12 is 20 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of various zones of the twin-screw body are set to 120°C, 130°C, 145°C, 155°C, 170°C, 180°C, 165°C, and 160°C respectively; the temperature of the post-absorption in step S3 is 65°C, and the time is 20 h.

[0189] Embodiment 13

[0190] The stirring time for mixing the materials in step 1 of Example 13 is 20 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of various zones of the twin-screw body are set to 120°C, 125°C, 140°C, 155°C, 165°C, 175°C, 165°C, and 160°C respectively; the temperature of the post-absorption in step S3 is 65°C, and the time is 20 h.

[0191] Embodiment 14

[0192] The stirring time for mixing the materials in step 1 of Example 14 is 20 min; the screw speed during twin-screw extrusion in step S2 is 150 r / min, and the temperatures of various zones of the twin-screw body are set to 120°C, 125°C, 140°C, 155°C, 165°C, 175°C, 165°C, and 160°C in sequence; the temperature of the post-absorption in step S3 is 65°C, and the time is 20 h.

[0193] Comparative Example 1

[0194] Comparative Example 1: The stirring time for mixing the materials in step 1 is 20 min; the screw speed during twin-screw extrusion in step S2 is 180 r / min, and the temperatures of each zone of the twin-screw body are set to 115 ℃, 125 ℃, 135 ℃, 140 ℃, 150 ℃, 165 ℃, 160 ℃, and 155 ℃ respectively; the temperature of the post-absorption in step S3 is 70 ℃, and the time is 15 h.

[0195] Comparative Example 2

[0196] Comparative Example 2: The stirring time for mixing the materials in step 1 is 20 min; the screw speed during twin-screw extrusion in step S2 is 180 r / min, and the temperatures of each zone of the twin-screw body are set to 115 ℃, 125 ℃, 135 ℃, 140 ℃, 150 ℃, 165 ℃, 160 ℃, and 155 ℃ respectively; the temperature of the post-absorption in step S3 is 70 ℃, and the time is 15 h.

[0197] 2. Performance Test

[0198] 1. Test Method

[0199] The insulating materials in the above embodiments and comparative examples were respectively hot-pressed by a flat vulcanizer: pre-pressed at 120°C and 10 MPa for 10 min, then hot-pressed at 180°C and 15 MPa for 20 min, and then cooled to room temperature to obtain insulating material samples.

[0200] Then, the obtained samples were degassed at 70 °C, and then the mechanical properties, electrical properties and yellow index were measured. The tensile properties were tested according to GB / T 1040.2-2022, the thermal elongation was tested according to GB / T 2951.21-2008, the breakdown strength was tested using a ball-ball electrode according to GB / T 1408.1-2016, the dielectric constant and dielectric loss were tested according to GB / T 1409-2006, and the yellow index was tested according to GB / T 39822-2021. The results are shown in Table 2.

[0201] Table 2

[0202]

[0203] From the results in Table 2, it can be seen that the yellowing-resistant cross-linked polyethylene insulation material provided by the present application is similar to the Borealis 4201 insulation material in terms of mechanical properties, electrical properties and yellow index. Among them, some insulation materials are significantly better than the 4201 insulation material in terms of tensile strength, elongation at break, and especially yellow index, showing good comprehensive performance. This shows that the yellowing-resistant cross-linked polyethylene insulation material provided by the present application has excellent yellowing resistance.

[0204] From the comparison of the results of Example 9 and Example 10, it can be seen that the yellowing resistance of the insulating material can be further improved by adding an auxiliary antioxidant.

[0205] From the comparison of the results of Example 9 and Comparative Example 1, it can be seen that when the insulating material contains a primary antioxidant, an auxiliary antioxidant and a carbon radical scavenger at the same time, the yellowing resistance of the insulating material can be effectively improved.

[0206] By comparing the results of Examples 1-10 and Comparative Example 2, it can be seen that when the carbon radical scavenger added to the insulating material is at least one of hindered amines, hydroxylamines, bisphenol monoacrylates, benzofuranones and ortho-allyl substituted phenols, the yellowing resistance of the insulating material can be effectively improved.

[0207] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0208] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A yellowing-resistant cross-linked polyethylene insulating material, characterized in that: It includes polyethylene, primary antioxidant, carbon free radical scavenger, auxiliary antioxidant, crosslinking agent and lubricant; Wherein, the primary antioxidant includes one or more hindered phenol antioxidants; The auxiliary antioxidant includes one or more of a thioester antioxidant and a phosphite antioxidant; The carbon radical scavenger includes one or more of pentamethylpiperidinol, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, isopropanolamine, ethanolamine and 2,2-oxalylamino-bis-[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate; The mass ratio of the primary antioxidant, the auxiliary antioxidant and the carbon radical scavenger is (0.1-1.5):(0.1-1):(0.1-0.5); The yellowing-resistant cross-linked polyethylene insulation material comprises the following components in parts by weight: Polyethylene 100 parts, Main antioxidant 0.1-1.5 parts, Auxiliary antioxidant 0.1-1.0 parts, Cross-linking agent 0.8-2.5 parts, 0.1-0.5 parts of carbon radical scavenger, and Lubricant 0.1 part -1.0 part.

2. The yellowing-resistant cross-linked polyethylene insulation material according to claim 1, characterized in that: The yellowing-resistant cross-linked polyethylene insulation material has at least one of the following characteristics (1)-(3): (1) The weight percentage of the primary antioxidant contained in the yellowing-resistant cross-linked polyethylene insulation material is 0.1 part to 1.0 part; (2) The carbon radical scavenger contained in the yellowing-resistant cross-linked polyethylene insulation material has an amount of 0.2 to 0.4 parts by weight; (3) In parts by weight, the cross-linking agent contained in the yellowing-resistant cross-linked polyethylene insulation material has an amount of 1.0 to 2.0 parts by weight.

3. The yellowing-resistant cross-linked polyethylene insulating material according to claim 1, characterized in that: The primary antioxidant includes one or more of 2,6-di-tert-butyl-4-methylphenol, 4,6-bis(octylthiomethyl)-o-cresol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 2,2'-thioethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

4. The yellowing-resistant cross-linked polyethylene insulation material according to claim 1, characterized in that: The auxiliary antioxidant includes one or more of didodecanol thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate), tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol bis diphosphite and tris (nonylphenol) phosphite.

5. The yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 4, characterized in that: The density of the polyethylene is 0.90 mol / cm 3 -0.98mol / cm 3 .

6. The yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 4, characterized in that: The polyethylene has a melt index of 1.6 g / 10 min to 2.5 g / 10 min.

7. The yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 4, characterized in that: The cross-linking agent includes one or more of peroxides.

8. The yellowing-resistant cross-linked polyethylene insulation material according to claim 7, characterized in that: The crosslinking agent includes one or more of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, dicumyl peroxide and di-tert-butyl peroxide.

9. The yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 4, characterized in that: The lubricant includes one or more of paraffin, stearyl alcohol, palmitol, polyethylene wax and polyethylene glycol ester.

10. The yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 4, characterized in that: The yellowing-resistant cross-linked polyethylene insulation material has at least one of the following characteristics (1)-(6): (1) The tensile strength of the yellowing-resistant cross-linked polyethylene insulation material is 21.5 MPa-26 MPa; (2) The elongation at break of the yellowing-resistant cross-linked polyethylene insulation material is 510%-575%; (3) The thermal elongation of the yellowing-resistant cross-linked polyethylene insulation material is 45%-60%; (4) The breakdown strength of the yellowing-resistant cross-linked polyethylene insulation material is 98.5 KV·mm -1 -102 KV mm -1 ; (5) The dielectric constant of the yellowing-resistant cross-linked polyethylene insulation material is 2.0 F·m -1 -2.21 F·m -1 ; (6) The yellowness index of the yellowing-resistant cross-linked polyethylene insulation material is -0.08~0.

38.

11. A method for preparing the yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 10, characterized in that: The steps include: The primary antioxidant, polyethylene, carbon free radical scavenger, lubricant and auxiliary antioxidant are mixed to prepare a mixed material; Extruding and granulating the mixed material to prepare an intermediate material; The intermediate material is mixed with a cross-linking agent and then subjected to post-absorption treatment to prepare the yellowing-resistant cross-linked polyethylene insulating material.

12. The preparation method according to claim 11, characterized in that: The preparation method comprises at least one of the following conditions: (1) The mixing temperature is 40° C., the mixing time is 15 min to 30 min, and the mixing method is stirring; (2) using a twin-screw extruder for the extrusion, the extrusion temperature is 115° C.-180° C., and the screw speed is 100 r / min-250 r / min; (3) The post-absorption treatment is performed at a temperature of 60°C to 80°C for a time of 12h to 20h; (4) After the extrusion, a cooling step is also included, and the cooling method is water cooling.

13. Use of the yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 10 in the preparation of cables.

14. A cable, characterized in that: The raw materials for preparing the cable include the yellowing-resistant cross-linked polyethylene insulation material according to any one of claims 1 to 10.

15. The cable according to claim 14, characterized in that The cable is a submarine cable.

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