Insulating material for wind-energy torsion-resistant cable as well as preparation method and application of insulating material

Abstract

The invention provides an insulating material for a wind energy torsion-resistant cable as well as a preparation method and application of the insulating material. The raw materials of the insulating material comprise a material A and a material B, the material A comprises the following raw materials in percentage by mass: 61%-65% of first ethylene propylene rubber, 15%-17% of polyethylene, 8%-15% of a first polyolefin elastomer, 5%-13% of a first filler, 0.1%-1% of an initiator and 2%-5% of a silane coupling agent; the material B comprises the following raw materials in percentage by mass: 61%-65% of second ethylene propylene rubber, 15%-22% of second polyolefin elastomer, 1%-11% of second filler, 10%-20% of an anti-aging agent and 3%-10% of a catalyst. The insulating material prepared by the invention has good torsion resistance.

Description

Technical Field

[0001] The present application relates to the field of cable technology, and in particular to an insulating material for wind-powered torsion-resistant cables, and a preparation method and application thereof. Background Art

[0002] At present, the torsion-resistant cables for wind power generation with a rated voltage of 1.8 / 3kV are all produced by continuous vulcanization production line technology. This type of equipment is a special production equipment for rubber cables, including rubber extrusion and vulcanization. Wind power generation has the characteristics of being renewable and pollution-free. It mainly relies on windmills to drive the generator set to generate electricity. However, during operation, the cables installed in the windmill will be twisted, rubbed, squeezed and vibrated as the windmill rotates, so the insulation layer in the cable needs to have better torsion resistance and mechanical properties. Summary of the invention

[0003] Based on this, it is necessary to provide an insulating material for wind power torsion-resistant cables with excellent torsion resistance and mechanical properties, as well as a preparation method and application thereof.

[0004] In a first aspect, the present application provides an insulating material, wherein the raw materials of the insulating material include material A and material B;

[0005] According to the mass ratio of the raw materials of the A material, the raw materials of the A material include:

[0006] First EPDM 61%~65%;

[0007] Polyethylene 15%~17%;

[0008] The first polyolefin elastomer is 8% to 15%;

[0009] The first filler is 5%~13%;

[0010] Initiator 0.1%~1%; and

[0011] Silane coupling agent 2%~5%;

[0012] According to the raw material mass ratio of the B material, the B material includes:

[0013] The second EPDM rubber is 61%~65%;

[0014] The second polyolefin elastomer 15%~22%;

[0015] The second filler 1%~11%;

[0016] Anti-aging agent 10%~20%; and,

[0017] Catalyst 3%~10%.

[0018] In some embodiments, the mass ratio of the A material to the B material is 90:10 to 95:5.

[0019] In some embodiments, the first polyolefin elastomer comprises ethylene-octene copolymer; optionally, the mass proportion of ethylene segments in the first polyolefin elastomer is 20% to 30%.

[0020] In some embodiments, the second polyolefin elastomer comprises ethylene-octene copolymer; optionally, the mass proportion of ethylene segments in the second polyolefin elastomer is 20% to 30%.

[0021] In some embodiments, the number average molecular weight of the polyethylene is 60,000-80,000.

[0022] In some embodiments, the silane coupling agent includes at least one of vinyltriethoxysilane and vinyltrimethoxysilane.

[0023] In some embodiments, the initiator includes at least one of dicumyl peroxide and 2,5-dimethyl-2,5-bis-(butylperoxy)hexane.

[0024] In some embodiments, the catalyst includes at least one of dibutyltin dilaurate, di-n-octyl dilaurate, and dodecylbenzenesulfonic acid.

[0025] In some embodiments, the first filler includes at least one of calcium carbonate and clay.

[0026] In some embodiments, the second filler includes at least one of calcium carbonate and clay.

[0027] In a second aspect, the present application provides a method for preparing an insulating material for a wind power torsion resistant cable as described in the first aspect, the preparation method comprising:

[0028] The first ethylene-propylene rubber, the polyethylene, the first polyolefin elastomer, the first filler, the initiator and the silane coupling agent are mixed, and the silane coupling agent is grafted to the first ethylene-propylene rubber, the polyethylene and the first polyolefin elastomer to obtain the material A;

[0029] Mixing the second ethylene-propylene rubber, the second polyolefin elastomer, the second filler, the catalyst and the antioxidant to obtain the B material;

[0030] The material A and the material B are mixed and cross-linked to prepare the insulating material.

[0031] In some embodiments, the method for preparing the A material comprises:

[0032] The first ethylene-propylene rubber, the polyethylene, the first polyolefin elastomer, the first filler, the initiator and the silane coupling agent are mixed at a first temperature, and after mixing, the first ethylene-propylene rubber, the polyethylene and the first polyolefin elastomer are grafted with the silane coupling agent at a second temperature to obtain the A material.

[0033] Optionally, the first temperature is 100°C~120°C.

[0034] Optionally, the second temperature is 145°C~175°C.

[0035] In some embodiments, the method of mixing and cross-linking the A material and the B material comprises:

[0036] The material A and the material B are mixed and extruded at a third temperature, and then steam cross-linked at a fourth temperature to prepare the insulating material.

[0037] Optionally, the third temperature is 125°C~160°C.

[0038] Optionally, the fourth temperature is 70°C~90°C.

[0039] In a third aspect, the present application provides an application of an insulating material for a wind-powered torsion-resistant cable as described in the first aspect, wherein the insulating material is used to prepare a cable.

[0040] Compared with the traditional technology, this application has at least the following beneficial effects:

[0041] In the process of preparing the insulating material, the present application adopts material A and material B to cross-link to form the insulating material, and high-temperature vulcanization is not required, and the preparation method is simple. The silane coupling agent is used to modify the ethylene-propylene rubber, polyethylene and polyolefin elastomer in material A, and cooperates with material B to improve the torsion resistance and mechanical properties of the insulating material. The cable insulation layer prepared by the insulating material of the present application can still ensure that the insulation is not broken after 10,000 cycles of testing under normal temperature conditions, with one forward and one reverse rotation as one cycle and a torsion angle of 1440°. DETAILED DESCRIPTION

[0042] Below in conjunction with the embodiments and examples, the present application is further described in detail. These embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms, and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent form obtained also falls within the protection scope of the present application. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0043] 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.

[0044] 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.

[0045] In this application, the terms "first", "second", etc. in "the first aspect", "the second aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0046] 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.

[0047] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0048] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the application purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0049] In traditional technology, torsion-resistant cables are produced using a continuous vulcanization production line process, which includes two parts: rubber extrusion and vulcanization. The preparation method is complicated and the temperature is high during the vulcanization process. In addition, in traditional technology, torsion-resistant cables are modified on the basis of traditional cables to improve torsion resistance, which leads to complex cable components and cumbersome preparation processes.

[0050] Based on this, the first aspect of the present application provides an insulating material for a wind power torsion-resistant cable, wherein the raw materials of the insulating material include material A and material B;

[0051] According to the mass ratio of the raw materials of the A material, the raw materials of the A material include:

[0052] First EPDM 61%~65%;

[0053] Polyethylene 15%~17%;

[0054] The first polyolefin elastomer is 8% to 15%;

[0055] The first filler is 5%~13%;

[0056] Initiator 0.1%~1%; and

[0057] Silane coupling agent 2%~5%;

[0058] According to the raw material mass ratio of the B material, the B material includes:

[0059] The second EPDM rubber is 61%~65%;

[0060] The second polyolefin elastomer 15%~22%;

[0061] The second filler 1%~11%;

[0062] Anti-aging agent 10%~20%; and,

[0063] Catalyst 3%~10%.

[0064] In the raw materials of material A, the mass proportion of the first ethylene propylene rubber may be 61.0%, 61.5%, 62.0%, 62.5%, 63.0%, 63.5%, 64.0%, 64.5% or 65.0%. The mass proportion of polyethylene may be 15.0%, 15.2%, 15.4%, 15.6%, 15.8%, 16.0%, 16.2%, 16.4%, 16.6%, 16.8% or 17.0%. The mass proportion of the first polyolefin elastomer may be 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.0%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5% or 15.0%. The mass proportion of the first filler can be 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.0%, 12.5% ​​or 13.0%. The mass proportion of the initiator can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1.0%. The mass proportion of the silane coupling agent can be 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% or 5.0%.

[0065] In the raw materials of material B, the mass proportion of the second ethylene propylene rubber can be 61.0%, 61.5%, 62.0%, 62.5%, 63.0%, 63.5%, 64.0%, 64.5% or 65.0%. The mass proportion of the second polyolefin elastomer can be 15%, 16%, 17%, 18%, 19%, 20%, 21% or 22%. The mass proportion of the second filler can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or 11%. The mass proportion of the antioxidant can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%. The mass proportion of the catalyst can be 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0066] In the process of preparing the insulating material, the present application adopts material A and material B to cross-link to form the insulating material, and high-temperature vulcanization is not required, and the preparation method is simple. The silane coupling agent is used to modify the ethylene-propylene rubber, polyethylene and polyolefin elastomer in material A, and cooperates with material B to improve the torsion resistance and mechanical properties of the insulating material. The cable insulation layer prepared by the insulating material of the present application can still ensure that the insulation is not broken after 10,000 cycles of testing under normal temperature conditions, with one forward and one reverse rotation as one cycle and a torsion angle of 1440°.

[0067] In some embodiments, the first EPDM rubber includes at least one of EPDM dipolymer and EPDM terpolymer; EPDM terpolymer may be selected.

[0068] In some embodiments, the second EPDM rubber includes at least one of EPDM dipolymer and EPDM terpolymer; EPDM terpolymer may be selected.

[0069] In some embodiments, the mass ratio of the material A to the material B is 90:10 to 95:5, for example, 90:10, 91:9, 92:8, 93:7, 94:6 or 95:5. The present application selects the mass ratio of the material A to the material B as above to ensure the crosslinking effect, avoid the problem of long crosslinking time, and may cause oxidation of the cable core, affect the electrical conductivity of the cable, and improve the torsion resistance, mechanical properties and insulation properties of the insulating material.

[0070] In some embodiments, the first polyolefin elastomer comprises ethylene-octene copolymer.

[0071] Optionally, the mass proportion of the ethylene segment in the first polyolefin elastomer is 20% to 30%, for example, it can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%.

[0072] Optionally, the molecular weight of the first polyolefin elastomer is 50,000-100,000, for example, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000 or 100,000.

[0073] In some embodiments, the second polyolefin elastomer comprises ethylene-octene copolymer.

[0074] Optionally, the mass proportion of the ethylene segment in the second polyolefin elastomer is 20% to 30%, for example, it can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%.

[0075] Optionally, the molecular weight of the second polyolefin elastomer is 50,000-100,000, for example, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000 or 100,000.

[0076] The first polyolefin elastomer and the second polyolefin elastomer selected in the present application have the advantages of high toughness, high elasticity, high fluidity, etc., and can improve the extrusion performance of the material when the proportion of rubber in the formula is relatively high, so as to adapt to the extrusion requirements of the extruder, and cooperate with each other to improve the torsion resistance and mechanical properties of the insulating material.

[0077] In some embodiments, the number average molecular weight of the polyethylene is 60000-80000, for example, 60000, 62000, 64000, 66000, 68000, 70000, 72000, 74000, 76000, 78000 or 80000. The molecular weight of the polyethylene selected in the present application as above effectively ensures the uniformity and stability of the overall cross-linking degree of the insulating material, takes into account the cable production and processing requirements, effectively avoids the problem of extrusion difficulties during the processing, and improves the insulation performance and mechanical properties of the insulating material.

[0078] In some embodiments, the silane coupling agent includes at least one of vinyltriethoxysilane and vinyltrimethoxysilane.

[0079] In some embodiments, the initiator includes at least one of dicumyl peroxide and 2,5-dimethyl-2,5-bis-(butylperoxy)hexane.

[0080] In some embodiments, the catalyst includes at least one of dibutyltin dilaurate, di-n-octyl dilaurate, and dodecylbenzenesulfonic acid.

[0081] In some embodiments, the first filler includes at least one of calcium carbonate and clay. Optionally, the first filler includes calcium carbonate and clay, and based on the mass of the material A being 100%, the mass of calcium carbonate accounts for 2% to 10%, and the mass of clay accounts for 2% to 10%.

[0082] In some embodiments, the second filler includes at least one of calcium carbonate and clay.

[0083] In some embodiments, the antioxidant includes at least one of antioxidant 168 and antioxidant 300. Antioxidant 168 refers to tris(2,4-di-tert-butylphenyl)phosphite; antioxidant 300 refers to 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0084] The second aspect of the present application provides a method for preparing the insulating material for the wind power torsion resistant cable as described in the first aspect, the preparation method comprising:

[0085] The first ethylene-propylene rubber, the polyethylene, the first polyolefin elastomer, the first filler, the initiator and the silane coupling agent are mixed, and the silane coupling agent is grafted to the first ethylene-propylene rubber, the polyethylene and the first polyolefin elastomer to obtain the material A;

[0086] Mixing the second ethylene-propylene rubber, the second polyolefin elastomer, the second filler, the catalyst and the antioxidant to obtain the B material;

[0087] The material A and the material B are mixed and cross-linked to prepare the insulating material.

[0088] The present application adopts the above preparation method to ensure the modification effect of material A, realize the cross-linking preparation of the insulating material without vulcanization, simplify the preparation method, and improve the insulation performance, mechanical properties and torsion resistance of the material.

[0089] In some embodiments, the method for preparing the material A comprises:

[0090] The first ethylene-propylene rubber, the polyethylene, the first polyolefin elastomer, the first filler, the initiator and the silane coupling agent are mixed at a first temperature, and after mixing, the first ethylene-propylene rubber, the polyethylene and the first polyolefin elastomer are grafted with the silane coupling agent at a second temperature to obtain the A material.

[0091] Optionally, the first temperature is 100°C to 120°C, for example, it may be 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C or 120°C.

[0092] Optionally, the second temperature is 145°C to 175°C, for example, 145°C, 148°C, 151°C, 154°C, 157°C, 160°C, 163°C, 166°C, 169°C, 172°C or 175°C.

[0093] The temperature in the grafting process is selected as above in the present application to ensure the grafting effect of the silane coupling agent with EPDM rubber, polyethylene and polyolefin elastomer, avoid the problem of premature cross-linking, and cooperate with material B to improve the cross-linking effect and ensure the insulation performance, mechanical properties and torsion resistance of the insulating material.

[0094] In some embodiments, the material A is mixed using an internal mixer. Further, the material A is subjected to granulation after grafting. For example, during the internal mixing and grafting reaction of the material A, the temperature of each stage of the screw machine can be reasonably allocated according to the screw machines with different aspect ratios.

[0095] Optionally, the aspect ratio of the screw machine can be 32 / 1~48 / 1.

[0096] Optionally, the temperature range is divided along the material flow direction in the screw machine. That is, the shear mixing, grafting reaction and extrusion granulation in the preparation process of material A are achieved through temperature zoning. Furthermore, the preparation process of material B and the mixing and cross-linking process of material A and material B can all be controlled by the screw machine for temperature range control to achieve operations such as mixing, cross-linking and extrusion.

[0097] In some embodiments, the method of mixing and cross-linking the A material and the B material comprises:

[0098] The material A and the material B are mixed and extruded at a third temperature, and then steam cross-linked at a fourth temperature to prepare the insulating material.

[0099] Optionally, the third temperature is 125°C-160°C, for example, it may be 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C or 160°C.

[0100] Optionally, the fourth temperature is 70° C. to 90° C., for example, 70° C., 72° C., 74° C., 76° C., 78° C., 80° C., 82° C., 84° C., 86° C., 88° C. or 90° C. The present application selects a steam cross-linking method to form an insulating material by reacting material A and material B. The preparation process is simple, and the cross-linking method of high temperature vulcanization in traditional technology is not required, and the prepared insulating material has excellent comprehensive performance.

[0101] Optionally, the steam cross-linking time is 8h~12h.

[0102] Exemplarily, a method for preparing the above insulating material is provided, comprising the following steps:

[0103] According to the mass ratio of the raw materials of the A material, the raw materials of the A material include:

[0104] First EPDM 61%~65%;

[0105] Polyethylene 15%~17%;

[0106] The first polyolefin elastomer is 8%~15%;

[0107] The first filler is 5%~13%;

[0108] Initiator 0.1%~1%; and

[0109] Silane coupling agent 2%~5%;

[0110] According to the raw material mass ratio of the B material, the B material includes:

[0111] The second EPDM rubber is 61%~65%;

[0112] The second polyolefin elastomer 15%~22%;

[0113] The second filler 1%~11%;

[0114] Anti-aging agent 10%~20%; and,

[0115] Catalyst 3%~10%.

[0116] The raw materials of material A are mixed at 100° C. to 120° C., and after mixing, grafting reaction is carried out in a screw extruder at 145° C. to 175° C. and extrusion granulation is carried out to obtain the material A;

[0117] Mix the raw materials of material B at 120°C to 130°C to obtain material B;

[0118] The material A and the material B are mixed in a mass ratio of 90:10 to 95:5 and extruded at 125° C. to 160° C., and then the extruded material is steam cross-linked at 70° C. to 90° C. for 8 h to 12 h to prepare the insulating material.

[0119] A third aspect of the present application provides an application of the insulating material for wind-powered torsion-resistant cables as described in the first aspect, wherein the insulating material is used to prepare cables.

[0120] In some embodiments, the cable includes a core, and an insulation layer and a sheath layer sequentially coated on the outer surface of the core, wherein the insulation layer adopts the above-mentioned insulation material of the present application.

[0121] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0122] In the following examples and comparative examples, the ethylene-propylene rubber is ethylene-propylene-diene monomer rubber, with a brand name of 3722P, purchased from Dow Chemical; and the brand name of the polyolefin elastomer is 8400, purchased from Dow Chemical.

[0123] Example 1

[0124] Weigh the raw materials of material A according to the mass ratio, including:

[0125] EPDM 62.0%;

[0126] Polyethylene 16.5%;

[0127] Polyolefin elastomer 9.7%;

[0128] Calcium carbonate 5.2%;

[0129] clay 3.4%;

[0130] Initiator 0.2%; and,

[0131] Silane coupling agent 3%;

[0132] The molecular weight of polyethylene is 80000, the initiator is diisopropylbenzene peroxide, and the silane coupling agent is silane coupling agent A151;

[0133] After the raw materials of material A are mixed evenly in an internal mixer, they are fed into a twin-screw extruder with a length-to-diameter ratio of 36 / 1 and a diameter of 65 mm through a conical double feeding system to prepare material A. The temperature range of the twin-screw extruder is as follows:

[0134]

[0135] That is, shear mixing is performed in zones 1 and 2, grafting reaction occurs in zones 3 to 7, extrusion is performed in zones 8 to 9, and the residence time in each zone is 2s.

[0136] Weigh the raw materials of material B according to the mass ratio, including:

[0137] EPDM 62%;

[0138] Polyolefin elastomer 15.8%;

[0139] Calcium carbonate 2.2%;

[0140] Anti-aging agent 168 7%;

[0141] Antioxidant 300 7%; and

[0142] Dibutyltin dilaurate 6%;

[0143] The raw materials of material B are mixed evenly in an internal mixer, and then fed into the same twin-screw extruder as that for preparing material A, and the material B is obtained after extrusion granulation. The temperature zones in the twin-screw extruder are as follows:

[0144]

[0145] After mixing material A and material B in a mass ratio of 92:8, add them into a cable extruder with an extrusion diameter of 90mm to produce 50mm 2 For bypass cable, the thickness of the extruded insulation material is 2.1 mm, and the temperature setting of the cable extruder is as follows:

[0146]

[0147] The extruded cable was cooled and coiled, and then steam cross-linked at 90° C. for 8 hours to prepare a cable having the insulating material.

[0148] Example 2

[0149] The cable was prepared according to the method of Example 1, except that:

[0150] Weigh the raw materials of material A according to the mass ratio, including:

[0151] EPDM 65%;

[0152] Polyethylene 15%;

[0153] Polyolefin elastomer 8%;

[0154] Calcium carbonate 3.8%;

[0155] clay 4.9%;

[0156] Initiator 0.3%; and,

[0157] Silane coupling agent 3%;

[0158] Among them, the molecular weight of polyethylene is 60000;

[0159] During the preparation of material A, the temperature range of the twin-screw extruder is as follows:

[0160]

[0161] Weigh the raw materials of material B according to the mass ratio, including:

[0162] EPDM 61%;

[0163] Polyolefin elastomer 22%;

[0164] Calcium carbonate 1%;

[0165] Anti-aging agent 168 5%;

[0166] Antioxidant 300 5%; and

[0167] Dibutyltin dilaurate 6%.

[0168] The mixing mass ratio of material A to material B is 90:10. After the cable is extruded, it is steam cross-linked at 70°C for 9 hours.

[0169] Example 3

[0170] The cable was prepared according to the method of Example 1, except that:

[0171] Weigh the raw materials of material A according to the mass ratio, including:

[0172] EPDM 61%;

[0173] Polyethylene 16.5%;

[0174] Polyolefin elastomer 12.3%;

[0175] Calcium carbonate 4%;

[0176] Clay 4%;

[0177] Initiator 0.2%; and,

[0178] Silane coupling agent 2%;

[0179] Among them, the molecular weight of polyethylene is 70,000;

[0180] During the preparation of material A, the temperature range of the twin-screw extruder is as follows:

[0181]

[0182] Weigh the raw materials of material B according to the mass ratio, including:

[0183] EPDM 65%;

[0184] Polyolefin elastomer 15%;

[0185] Calcium carbonate 2%;

[0186] Anti-aging agent 168 7%;

[0187] Antioxidant 300 7%; and

[0188] Dibutyltin dilaurate 4%.

[0189] The mixing mass ratio of material A to material B is 90:10. After the cable is extruded, it is steam cross-linked at 80°C for 8 hours.

[0190] Example 4

[0191] A cable was prepared according to the method of Example 1, except that the mass ratio of material A to material B was 88:12.

[0192] Example 5

[0193] A cable was prepared according to the method of Example 1, except that the mass ratio of material A to material B was 97:3.

[0194] Comparative Example 1

[0195] A cable was prepared according to the method of Example 1, except that the polyolefin elastomer in the raw material of material A was replaced by polyethylene of the same mass.

[0196] Comparative Example 2

[0197] A cable was prepared according to the method of Example 1, except that the polyethylene in the raw material of material A was replaced by a polyolefin elastomer of the same mass.

[0198] Comparative Example 3

[0199] A cable was prepared according to the method of Example 1, except that the polyolefin elastomer in the raw material of material B was replaced by polyethylene of the same mass.

[0200] Comparative Example 4

[0201] The cable was prepared according to the method of Example 1, except that:

[0202] Weigh the raw materials of material A according to the mass ratio, including:

[0203] EPDM 60%;

[0204] Polyethylene 18%;

[0205] Calcium carbonate 8%;

[0206] clay 9.85%;

[0207] Initiator 0.15%; and,

[0208] Silane coupling agent 4%.

[0209] Weigh the raw materials of material B according to the mass ratio, including:

[0210] EPDM 60%;

[0211] Polyethylene 18%;

[0212] Calcium carbonate 2%;

[0213] Anti-aging agent 168 7%;

[0214] Antioxidant 300 7%; and

[0215] Dibutyltin dilaurate 6%.

[0216] Comparative Example 5

[0217] The cable was prepared according to the method of Example 1, except that:

[0218] Weigh the raw materials of material A according to the mass ratio, including:

[0219] EPDM 58.2%;

[0220] Polyethylene 16.5%;

[0221] Polyolefin elastomer 13.5%;

[0222] Calcium carbonate 5.2%;

[0223] clay 3.4%;

[0224] Initiator 0.2%; and,

[0225] Silane coupling agent 3%.

[0226] Weigh the raw materials of material B according to the mass ratio, including:

[0227] EPDM 58%;

[0228] Polyolefin elastomer 19.8%;

[0229] Calcium carbonate 2.2%;

[0230] Anti-aging agent 168 7%;

[0231] Antioxidant 300 7%; and

[0232] Dibutyltin dilaurate 6%.

[0233] Comparative Example 6

[0234] The cable was prepared according to the method of Example 1, except that:

[0235] Weigh the raw materials of material A according to the mass ratio, including:

[0236] EPDM 66%;

[0237] Polyethylene 16.5%;

[0238] Polyolefin elastomer 5.7%;

[0239] Calcium carbonate 5.2%;

[0240] clay 3.4%;

[0241] Initiator 0.2%; and,

[0242] Silane coupling agent 3%.

[0243] Weigh the raw materials of material B according to the mass ratio, including:

[0244] EPDM 66%;

[0245] Polyolefin elastomer 11.8%;

[0246] Calcium carbonate 2.2%;

[0247] Anti-aging agent 168 7%;

[0248] Antioxidant 300 7%; and

[0249] Dibutyltin dilaurate 6%.

[0250] The performance of the cables prepared in the above embodiments and comparative examples was tested, and the testing method was as follows:

[0251] GB / T 2951-2008, GB / T 5470-2008, GB / T 31838.2-2019, GB / T 1408.1-2016, GB / T29631-2013, etc. The test results are shown in Table 1 and Table 2.

[0252] Table 1

[0253]

[0254]

[0255] Table 2

[0256]

[0257]

[0258] From the above table we can see that:

[0259] (1) Compared with Examples 4-5, it can be seen that the present application controls the mass ratio of material A to material B, thereby having the advantages of fast crosslinking speed and high crosslinking degree, and can avoid problems such as reduction in mechanical properties caused by over-crosslinking.

[0260] (2) Compared with Comparative Examples 1-4, it can be seen that the present application uses ethylene-propylene rubber, polyethylene and polyolefin elastomers for coordination, so as to have the advantages of good appearance, stable extrusion performance, good torsion resistance, etc. Further, compared with Comparative Examples 5-6, it can be seen that the present application controls the content of the components in material A and material B, which can avoid the problem of the extruder being unable to extrude due to the excessively high proportion of rubber, and other problems.

[0261] In summary, in the process of preparing the insulating material, the present application adopts material A and material B to cross-link to form the insulating material, and high-temperature vulcanization is not required, and the preparation method is simple. The silane coupling agent is used to modify the ethylene-propylene rubber, polyethylene and polyolefin elastomer in material A, and cooperates with material B to improve the torsion resistance and mechanical properties of the insulating material. The cable insulation layer prepared by the insulating material of the present application can still ensure that the insulation is not broken after 10,000 cycles of testing under normal temperature conditions, with one forward and one reverse rotation as one cycle and a torsion angle of 1440°.

[0262] 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.

[0263] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An insulating material for a wind-resistant torsion cable, characterized in that: The raw materials of the insulating material include material A and material B; According to the mass ratio of the raw materials of the A material, the raw materials of the A material include: First EPDM 61%~65%; Polyethylene 15%~17%; The first polyolefin elastomer is 8%~15%; The first filler is 5%~13%; Initiator 0.1%~1%; and Silane coupling agent 2%~5%; According to the raw material mass ratio of the B material, the B material includes: The second EPDM rubber is 61%~65%; The second polyolefin elastomer 15%~22%; The second filler 1%~11%; Anti-aging agent 10%~20%; and, Catalyst 3%~10%.

2. The insulating material for wind-resistant torsion cable according to claim 1, characterized in that: The mass ratio of the A material to the B material is 90:10-95:

5.

3. The insulating material for wind-resistant torsion cable according to claim 1, characterized in that: The insulating material satisfies at least one of the following conditions: (1) The first polyolefin elastomer comprises ethylene-octene copolymer; optionally, the mass proportion of ethylene segments in the first polyolefin elastomer is 20% to 30%; (2) The second polyolefin elastomer comprises ethylene-octene copolymer; optionally, the mass proportion of ethylene segments in the second polyolefin elastomer is 20% to 30%.

4. The insulating material for wind-resistant torsion cable according to claim 1, characterized in that: The A material satisfies at least one of the following conditions: (1) The number average molecular weight of the polyethylene is 60,000 to 80,000; (2) The silane coupling agent includes at least one of vinyltriethoxysilane and vinyltrimethoxysilane; (3) The initiator includes at least one of dicumyl peroxide and 2,5-dimethyl-2,5-bis-(butylperoxy)hexane.

5. The insulating material for wind-resistant torsion cable according to claim 1, characterized in that: The catalyst includes at least one of dibutyltin dilaurate, di-n-octyl dilaurate and dodecylbenzenesulfonic acid.

6. The insulating material for wind-powered torsion-resistant cable according to any one of claims 1 to 5, characterized in that: The insulating material also satisfies at least one of the following conditions: (1) The first filler includes at least one of calcium carbonate and clay; (2) The second filler includes at least one of calcium carbonate and clay.

7. A method for preparing an insulating material for a wind-powered torsion-resistant cable according to any one of claims 1 to 6, characterized in that: The preparation method comprises: The first ethylene-propylene rubber, the polyethylene, the first polyolefin elastomer, the first filler, the initiator and the silane coupling agent are mixed, and the silane coupling agent is grafted to the first ethylene-propylene rubber, the polyethylene and the first polyolefin elastomer to obtain the material A; Mixing the second ethylene-propylene rubber, the second polyolefin elastomer, the second filler, the catalyst and the antioxidant to obtain the B material; The material A and the material B are mixed and cross-linked to prepare the insulating material.

8. The preparation method according to claim 7, characterized in that: The preparation method of the A material comprises: The first ethylene-propylene rubber, the polyethylene, the first polyolefin elastomer, the first filler, the initiator and the silane coupling agent are mixed at a first temperature, and after mixing, the first ethylene-propylene rubber, the polyethylene and the first polyolefin elastomer are grafted with the silane coupling agent at a second temperature to obtain the material A; Optionally, the first temperature is 100°C to 120°C; Optionally, the second temperature is 145°C~175°C.

9. The preparation method according to claim 7 or 8, characterized in that: The method of mixing and cross-linking the material A and the material B comprises: The material A and the material B are mixed and extruded at a third temperature, and after extrusion, steam cross-linked at a fourth temperature to prepare the insulating material; Optionally, the third temperature is 125° C. to 160° C.; Optionally, the fourth temperature is 70°C~90°C.

10. An application of the insulating material for wind-powered torsion-resistant cables according to any one of claims 1 to 6, characterized in that: The insulating material is used for preparing cables.

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