High-temperature resistant insulating rubber, its preparation method and application

Abstract

This application provides a high-temperature resistant insulating rubber, its preparation method, and its application. By weight, the high-temperature resistant insulating rubber comprises the following raw materials: 10-20 parts ethylene-vinyl acetate, 85-100 parts ethylene-octene copolymer, 30-50 parts calcined modified kaolin, 10-15 parts liquid ethylene-propylene rubber, 0.3-0.6 parts coupling agent, 10-15 parts antioxidant, 15-20 parts titanium dioxide, 20-30 parts indirect zinc oxide, 1-2 parts stearic acid, 1-2 parts microcrystalline wax, 10-15 parts talc, 2-4 parts co-curing agent, and 2-6 parts curing agent. In the insulating rubber of this application, the specific weight proportions of the raw materials work synergistically to prepare an insulating rubber with excellent high-temperature aging resistance, mechanical properties, and electrical insulation properties.

Description

Technical Field

[0001] This application relates to the field of insulating materials technology, and in particular to a high-temperature resistant insulating rubber, its preparation method and application. Background Technology

[0002] With the continuous increase in transmission power and conductor operating current in the cable industry, the heat generation of conductors has shown a significant upward trend while keeping cable specifications unchanged; therefore, higher requirements are also placed on the thermal stability of cable insulation materials.

[0003] Currently, the maximum temperature limit for long-term operation of polyvinyl chloride (PVC) insulation materials is 70°C, while that for cross-linked polyethylene (XLPE) and ethylene propylene rubber (EPR) insulation materials is 90°C. When the conductor temperature exceeds the 90°C threshold, these materials will face the risk of failure, such as accelerated thermal aging and decreased mechanical strength.

[0004] Researchers have explored the aforementioned technical bottlenecks, but in the process of pursuing heat resistance optimization, they have failed to effectively balance the electrical insulation properties of the insulation material, making it difficult to meet the technical requirements of cable insulation layers. Summary of the Invention

[0005] Based on this, one or more embodiments of this application provide an insulating rubber that is resistant to high temperatures and has excellent insulating properties, as well as its preparation method and application.

[0006] According to a first aspect of the embodiments of this application, a high-temperature resistant insulating rubber is provided, comprising, by weight parts, the following raw materials:

[0007] 10-20 parts of ethylene-vinyl acetate

[0008] 85-100 parts of ethylene-octene copolymer

[0009] 30-50 parts of calcined modified kaolin

[0010] 10-15 parts of liquid ethylene propylene rubber

[0011] Coupling agent 0.3~0.6 parts,

[0012] Anti-aging agent 10-15 parts

[0013] 15-20 parts of titanium dioxide

[0014] Indirect method zinc oxide 20-30 parts,

[0015] 1-2 parts stearic acid

[0016] 1-2 parts of microcrystalline wax

[0017] 10-15 parts talcum powder

[0018] 2-4 parts of vulcanizing agent

[0019] 2-6 parts of vulcanizing agent.

[0020] In some embodiments, the mass ratio of the ethylene-vinyl acetate to the ethylene-octene copolymer is 1:(5~7).

[0021] In some embodiments, the high-temperature resistant insulating rubber satisfies at least one of the following characteristics:

[0022] (1) The vinyl acetate content in the ethylene-vinyl acetate is 18%~30% by mass;

[0023] (2) Under the conditions of 190℃ and 2.16kg pressure, the melt flow rate of the ethylene-vinyl acetate is 2g / 10min~4g / 10min;

[0024] (3) The melting point of the ethylene-vinyl acetate is 60℃~80℃.

[0025] In some embodiments, the high-temperature resistant insulating rubber satisfies at least one of the following characteristics:

[0026] (1) Under the conditions of 190℃ and 2.16kg pressure, the melt flow rate of the ethylene-octene copolymer is 0.2g / 10min~1g / 10min;

[0027] (2) Under the conditions of ML 1+4 and 121℃, the Mooney viscosity of the ethylene-octene copolymer is 30~40;

[0028] (3) The melting point of the ethylene-octene copolymer is 40℃~50℃.

[0029] In some embodiments, the high-temperature resistant insulating rubber satisfies at least one of the following characteristics:

[0030] (1) The particle size of the calcined modified kaolin is 6000 mesh to 10000 mesh;

[0031] (2) The modifier of the calcined modified kaolin is a titanate coupling agent.

[0032] In some embodiments, the high-temperature resistant insulating rubber satisfies at least one of the following characteristics:

[0033] (1) The weight-average molecular weight of the liquid ethylene propylene rubber is 10,000 to 30,000;

[0034] (2) The mass content of ethylene structural units in the liquid ethylene propylene rubber is 45%~55%.

[0035] In some embodiments, the high-temperature resistant insulating rubber satisfies at least one of the following characteristics:

[0036] (1) The coupling agent includes one or both of titanate coupling agents and aluminate coupling agents;

[0037] (2) The antioxidant includes one or more of 4,4'-di(phenylisopropyl)diphenylamine, pentaerythritol tetra(3-lauryl thiopropionate) and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene;

[0038] (3) The co-vulcanizing agent includes one or more of triallyl isocyanurate and N,N'-m-phenylene-bismaleimide;

[0039] (4) The vulcanizing agent includes one or more of 1,4-di-tert-butylperoxyisopropylbenzene and dicumyl peroxide;

[0040] (5) The titanium dioxide includes rutile titanium dioxide;

[0041] (6) The zinc oxide content in the indirect zinc oxide process is ≥99.7% by mass;

[0042] (7) The particle size of the talc powder is 2000 mesh to 3000 mesh.

[0043] In some embodiments, the high-temperature resistant insulating rubber satisfies at least one of the following characteristics:

[0044] (1) The melting point of the microcrystalline wax is 65℃~70℃;

[0045] (2) At 100°C, the kinematic viscosity of the microcrystalline wax is 6 mm. 2 / s~8mm 2 / s;

[0046] (3) At 25°C, the penetration of the microcrystalline wax is 10 (mm / 10) to 15 (mm / 10).

[0047] According to a second aspect of the embodiments of this application, a method for preparing high-temperature resistant insulating rubber is provided, comprising the following steps:

[0048] The above-mentioned raw materials for preparing high-temperature resistant insulating rubber are provided, and the raw materials are mixed to prepare the insulating rubber.

[0049] According to a third aspect of the embodiments of this application, the application of the high-temperature resistant insulating rubber as described above or the high-temperature resistant insulating rubber prepared by the above preparation method in the manufacture of power transmission products is provided.

[0050] According to a fourth aspect of the embodiments of this application, a cable is provided, comprising the high-temperature resistant insulating rubber described above or the high-temperature resistant insulating rubber prepared by the above-described preparation method.

[0051] Compared with traditional technologies, this application has the following advantages:

[0052] In the insulating rubber of this application, specific mass proportions of the raw materials are combined and work synergistically to prepare an insulating rubber with excellent high-temperature aging resistance, mechanical properties, and electrical insulation properties. Specifically, the combination of ethylene-vinyl acetate and ethylene-octene copolymer imparts excellent processing and mechanical properties; calcined modified kaolin imparts excellent electrical insulation and mechanical properties; and the addition of antioxidants, titanium dioxide, indirect zinc oxide, and liquid ethylene propylene rubber imparts excellent aging resistance, enabling the rubber to be used for more than 25 years at an operating temperature of 105℃. Detailed Implementation

[0053] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared by existing methods.

[0055] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of 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 this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0056] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0057] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0058] In this document, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0059] In this document, terms such as “preferred,” “better,” “more suitable,” and “ideal” are merely used to describe implementation methods or examples that achieve better results, and should be understood not to limit the scope of protection of this application.

[0060] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0061] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0062] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0063] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0064] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0065] In this application, %(w / w) and wt% both represent weight percentage, %(v / v) refers to volume percentage, and %(w / v) refers to mass-volume percentage.

[0066] Some embodiments of this application provide a high-temperature resistant insulating rubber, comprising the following raw materials by weight:

[0067] 10-20 parts of ethylene-vinyl acetate

[0068] 85-100 parts of ethylene-octene copolymer

[0069] 30-50 parts of calcined modified kaolin

[0070] 10-15 parts of liquid ethylene propylene rubber

[0071] Coupling agent 0.3~0.6 parts,

[0072] Anti-aging agent 10-15 parts

[0073] 15-20 parts of titanium dioxide

[0074] Indirect method zinc oxide 20-30 parts,

[0075] 1-2 parts stearic acid

[0076] 1-2 parts of microcrystalline wax

[0077] 10-15 parts talcum powder

[0078] 2-4 parts of vulcanizing agent

[0079] 2-6 parts of vulcanizing agent.

[0080] In the insulating rubber of this application, specific mass proportions of the raw materials are combined and work synergistically to prepare an insulating rubber with excellent high-temperature aging resistance, mechanical properties, and electrical insulation properties. Specifically, the combination of ethylene-vinyl acetate and ethylene-octene copolymer imparts excellent processing and mechanical properties; calcined modified kaolin imparts excellent electrical insulation and mechanical properties; and the addition of antioxidants, titanium dioxide, indirect zinc oxide, and liquid ethylene propylene rubber imparts excellent aging resistance, enabling the rubber to be used for more than 25 years at an operating temperature of 105℃.

[0081] As an example, the mass fraction of ethylene-vinyl acetate can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of ethylene-vinyl acetate is 15 to 18 parts. Even further, the mass fraction of ethylene-vinyl acetate is 20 parts.

[0082] As an example, the mass fractions of the ethylene-octene copolymer can be 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100 parts, or any value within the range formed by any two of the above points. Further, the mass fractions of the ethylene-octene copolymer are 85 to 95 parts. Even further, the mass fractions of the ethylene-octene copolymer are 80 parts.

[0083] As an example, the mass fraction of calcined modified kaolin can be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of calcined modified kaolin is 30 to 40 parts. Even further, the mass fraction of calcined modified kaolin is 35 parts.

[0084] As an example, the mass fraction of liquid ethylene propylene rubber can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of liquid ethylene propylene rubber is 12 to 14 parts. Even further, the mass fraction of liquid ethylene propylene rubber is 13 parts.

[0085] As an example, the mass fraction of the coupling agent can be 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of the coupling agent is 0.4 to 0.5 parts. Even further, the mass fraction of the coupling agent is 0.44 parts.

[0086] As an example, the mass fraction of the antioxidant can be 10, 11, 12, 13, 14, or 15 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of the antioxidant is 12 to 14 parts. Even further, the mass fraction of the antioxidant is 13 parts.

[0087] As an example, the mass fraction of titanium dioxide can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, or 20 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of titanium dioxide is 17 to 19 parts. Even further, the mass fraction of titanium dioxide is 18 parts.

[0088] As an example, the mass fraction of zinc oxide produced by the indirect method can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, or 30 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of zinc oxide produced by the indirect method is 23 to 28 parts. Even further, the mass fraction of zinc oxide produced by the indirect method is 26 parts.

[0089] As an example, the mass fraction of stearic acid can be 1 part, 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, or 2 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of stearic acid is 1.2 to 1.6 parts. Even further, the mass fraction of stearic acid is 1.5 parts.

[0090] As an example, the mass fraction of microcrystalline wax can be 1 part, 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, or 2 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of microcrystalline wax is 1.2 to 1.6 parts. Even further, the mass fraction of microcrystalline wax is 1.5 parts.

[0091] As an example, the mass fraction of talc can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of talc is 11 to 14 parts. Even further, the mass fraction of talc is 12 parts.

[0092] As an example, the mass fraction of the vulcanizing agent can be 2 parts, 3 parts, 4 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of the vulcanizing agent is 2 to 3 parts. Even further, the mass fraction of the vulcanizing agent is 2.5 parts.

[0093] As an example, the mass fraction of the vulcanizing agent can be 2 parts, 3 parts, 4 parts, 5 parts, or 6 parts, or any value within the range formed by any two of the above points. Further, the mass fraction of the vulcanizing agent is 4 to 6 parts. Even further, the mass fraction of the vulcanizing agent is 5.2 parts.

[0094] In some embodiments, the raw materials for preparing the high-temperature resistant insulating rubber, by weight parts, are:

[0095] 10-20 parts of ethylene-vinyl acetate

[0096] 85-100 parts of ethylene-octene copolymer

[0097] 30-50 parts of calcined modified kaolin

[0098] 10-15 parts of liquid ethylene propylene rubber

[0099] Coupling agent 0.3~0.6 parts,

[0100] Anti-aging agent 10-15 parts

[0101] 15-20 parts of titanium dioxide

[0102] Indirect method zinc oxide 20-30 parts,

[0103] 1-2 parts stearic acid

[0104] 1-2 parts of microcrystalline wax

[0105] 10-15 parts talcum powder

[0106] 2-4 parts of vulcanizing agent

[0107] 2-6 parts of vulcanizing agent.

[0108] In some embodiments, the high-temperature insulating rubber comprises, by weight parts, the following raw materials:

[0109] 15-18 parts of ethylene-vinyl acetate

[0110] 85-95 parts of ethylene-octene copolymer

[0111] 30-40 parts of calcined modified kaolin

[0112] 12-14 parts of liquid ethylene propylene rubber

[0113] 0.4-0.5 parts of coupling agent

[0114] Anti-aging agent 12-14 parts

[0115] 17-19 parts titanium dioxide

[0116] Indirect method zinc oxide 24-28 parts

[0117] Stearic acid 1.2~1.6 parts

[0118] Microcrystalline wax 1.2~1.6 parts,

[0119] 11-14 parts talcum powder

[0120] 2-3 parts of vulcanizing agent

[0121] 4-6 parts of vulcanizing agent.

[0122] In some embodiments, the high-temperature insulating rubber comprises, by weight parts, the following raw materials:

[0123] 20 parts of ethylene-vinyl acetate

[0124] 80 parts of ethylene-octene copolymer

[0125] 35 parts of calcined modified kaolin

[0126] 13 parts of liquid ethylene propylene rubber

[0127] 0.44 parts of coupling agent

[0128] 13 parts of anti-aging agent

[0129] 18 parts of titanium dioxide

[0130] 26 parts of indirect zinc oxide

[0131] 1.5 parts stearic acid

[0132] 1.5 parts microcrystalline wax

[0133] 12 parts talcum powder

[0134] 2.5 parts of vulcanizing agent

[0135] 5.2 parts of vulcanizing agent.

[0136] In some embodiments, the mass ratio of ethylene-vinyl acetate to ethylene-octene copolymer is 1:(5~7). As an example, the mass ratio of ethylene-vinyl acetate to ethylene-octene copolymer can be 1:5, 1:6, 1:7, or any value within the range of any two of the above ratios.

[0137] It is understandable that ethylene-vinyl acetate has excellent extrusion properties, which can improve the extrusion appearance of ethylene-octene copolymers and make the extruded rubber compound smooth. Therefore, the combination of ethylene-vinyl acetate and ethylene-octene copolymers can endow the rubber compound with excellent processing and mechanical properties.

[0138] In some embodiments, the vinyl acetate content in the ethylene-vinyl acetate ester is 18% to 30% by mass. As an example, the vinyl acetate content in the ethylene-vinyl acetate ester can be 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, or any value within the range formed by any two of the above points. Further, the vinyl acetate content in the ethylene-vinyl acetate ester is 26% by mass.

[0139] In some embodiments, the melt flow rate of ethylene-vinyl acetate is 2 g / 10 min to 4 g / 10 min under conditions of 190 °C and 2.16 kg pressure. As an example, the melt flow rate of ethylene-vinyl acetate can be 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, or any value within the range formed by any two of the above points.

[0140] It should be noted that "g / 10min" in this application refers to the amount of thermoplastic material extruded within a certain time, that is, the mass of melt passing through the standard die capillary every 10 minutes.

[0141] In some embodiments, the melting point of ethylene-vinyl acetate is 60°C to 80°C. As an example, the melting point of ethylene-vinyl acetate can be 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C, or 80°C, or any value within the range of any two of the above values. Further, the melting point of ethylene-vinyl acetate is 76°C.

[0142] In some embodiments, the melt flow rate of the ethylene-octene copolymer is 0.2 g / 10 min to 1 g / 10 min under conditions of 190°C and 2.16 kg pressure. As an example, the melt flow rate of the ethylene-octene copolymer can be 0.2 g / 10 min, 0.3 g / 10 min, 0.4 g / 10 min, 0.5 g / 10 min, 0.6 g / 10 min, 0.7 g / 10 min, 0.8 g / 10 min, 0.9 g / 10 min, 1 g / 10 min, or any value within the range formed by any two of the above values.

[0143] In some embodiments, the Mooney viscosity of the ethylene-octene copolymer is 30-40 under ML 1+4 and 121°C conditions. As an example, the Mooney viscosity of the ethylene-octene copolymer can be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40, or any value within the range formed by any two of the above points.

[0144] It should be noted that in "ML 1+4, 121℃", "ML" indicates that the Mooney viscosity value was measured using a large rotor, "1" indicates that the preheating time was 1 minute, "4" indicates that the rotation time was 4 minutes, and "121℃" indicates that the temperature during measurement was 121℃.

[0145] In some embodiments, the melting point of the ethylene-octene copolymer is 40°C to 50°C. As an example, the melting point of the ethylene-octene copolymer can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, or any value within the range formed by any two of the above points.

[0146] In some embodiments, the particle size of the calcined modified kaolin is 6000 mesh to 10000 mesh. As an example, the particle size of the calcined modified kaolin can be 6000 mesh, 6500 mesh, 7000 mesh, 7500 mesh, 8000 mesh, 8500 mesh, 9000 mesh, 9500 mesh, 10000 mesh, or any value within the range formed by any two of the above values.

[0147] It is understandable that controlling the particle size of calcined modified kaolin within the above-mentioned range can enable the adhesive to meet the corresponding insulation requirements, allowing the powder material to be better dispersed in the adhesive matrix, resulting in more stable performance and preventing stress concentration points from forming.

[0148] In some embodiments, the modifier for calcined modified kaolin is a titanate coupling agent.

[0149] In some embodiments, calcined modified kaolin is prepared by the following steps: kaolin is ground to the required mesh size using a grinder and calcined for 45 minutes at 950℃±20℃; the calcined material is cooled to room temperature to obtain calcined kaolin; the calcined kaolin is added to a high-speed mixer; and at 105℃, 2% of the modifier (a diluted solution of titanate coupling agent, the diluent being alcohol, with a mass concentration of 50% titanate coupling agent in the diluted solution) is added by spraying. After complete addition, the mixture is stirred at high speed again for 10 minutes to obtain calcined modified kaolin.

[0150] In some of these examples, the high-speed stirring speed is 100 r / min to 150 r / min.

[0151] In some embodiments, the weight-average molecular weight of the liquid ethylene propylene rubber is 10,000 to 30,000. As an example, the weight-average molecular weight of the liquid ethylene propylene rubber can be 10,000, 12,000, 14,000, 16,000, 18,000, 20,000, 22,000, 24,000, 26,000, 28,000, 30,000, or any value within the range formed by any two of the above points.

[0152] In some embodiments, the mass content of ethylene structural units in the liquid ethylene propylene rubber is 45% to 55%. As an example, the mass content of ethylene structural units in the liquid ethylene propylene rubber can be 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, or any value within the range formed by any two of the above points.

[0153] In some embodiments, the coupling agent includes one or both of titanate coupling agents and aluminate coupling agents.

[0154] In some embodiments, the antioxidant includes one or more of 4,4'-bis(phenylisopropyl)diphenylamine, pentaerythritol tetra(3-lauryl thiopropionate), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0155] In some specific examples, the effective content of the antioxidant is 99% or higher.

[0156] In some embodiments, the co-vulcanizing agent includes one or more of triallyl isocyanurate and N,N'-m-phenylene-bismaleimide.

[0157] In some embodiments, the vulcanizing agent includes one or more of 1,4-di-tert-butylperoxyisopropylbenzene and dicumyl peroxide.

[0158] In some embodiments, the titanium dioxide includes rutile titanium dioxide.

[0159] In some of these embodiments, the zinc oxide content in the indirect zinc oxide process is ≥97.7% by mass.

[0160] In some embodiments, the particle size of the talc powder is 2000 mesh to 3000 mesh. As an example, the particle size of the talc powder can be 2000 mesh, 2100 mesh, 2200 mesh, 2300 mesh, 2400 mesh, 2500 mesh, 2600 mesh, 2700 mesh, 2800 mesh, 2900 mesh, 3000 mesh, or any value within the range formed by any two of the above values.

[0161] In some embodiments, the melting point of the microcrystalline wax is 65°C to 70°C. As an example, the melting point of the microcrystalline wax can be 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, or any value within the range formed by any two of the above points.

[0162] In some embodiments, the kinematic viscosity of the microcrystalline wax is 6 mm at 100°C. 2 / s~8mm 2 / s. As an example, the kinematic viscosity of microcrystalline wax can be 6 mm. 2 / s, 7mm 2 / s, 8mm 2 / s, or any value within the range formed by any two of the above point values.

[0163] In some embodiments, the penetration of the microcrystalline wax is 10 (mm / 10) to 15 (mm / 10) at 25°C. As an example, the penetration of the microcrystalline wax can be 10 (mm / 10), 11 (mm / 10), 12 (mm / 10), 13 (mm / 10), 14 (mm / 10), 15 (mm / 10), or any value within the range formed by any two of the above points.

[0164] The insulating rubber of this application has at least the following advantages: (1) It has excellent high-temperature aging resistance, mechanical properties and electrical insulation properties. (2) The raw materials used in its preparation are environmentally friendly materials and are harmless to human health. (3) The raw materials used in its preparation are inexpensive and readily available, giving it a cost advantage.

[0165] Some embodiments of this application also provide a method for preparing high-temperature resistant insulating rubber, comprising the following steps:

[0166] The above-mentioned raw materials for preparing insulating rubber are provided, and the raw materials are mixed to prepare insulating rubber.

[0167] In some embodiments, the preparation method of the above-mentioned high-temperature resistant insulating rubber includes the following steps:

[0168] S10: The ethylene-vinyl acetate and ethylene-octene copolymer are compounded to obtain a first mixture;

[0169] S20: Add antioxidant, indirect zinc oxide, stearic acid and microcrystalline wax to the first mixture, and knead to obtain the second mixture;

[0170] S30: Add liquid ethylene propylene rubber, coupling agent, calcined modified kaolin, titanium dioxide and talc to the second mixture, and mix to obtain a rubber matrix;

[0171] S40: Add a vulcanizing agent and a vulcanizing agent to the rubber matrix, and then mix, filter and roll the mixture in sequence to prepare insulating rubber.

[0172] In some embodiments, the mixing is performed using a mixer.

[0173] In some embodiments, filtration is performed using a gear pump filter.

[0174] The preparation method described in this application can effectively filter out impurities and foreign matter in the adhesive, thereby improving the electrical insulation performance of the adhesive.

[0175] Some embodiments of this application also provide the application of the insulating rubber as described above or the insulating rubber prepared by the preparation method described above in the preparation of power transmission products.

[0176] Some embodiments of this application also provide a cable comprising the insulating rubber described above or the insulating rubber prepared by the above-described preparation method.

[0177] The present application will be further described below with reference to specific embodiments and comparative examples, but these should not be construed as limiting the scope of protection of the present application. Unless otherwise specified, the raw materials involved in the following specific embodiments are all commercially available, the instruments used are all commercially available, and the processes involved are conventionally selected by those skilled in the art unless otherwise specified.

[0178] Example 1

[0179] (1) By mass, the following components are provided: 18 parts of ethylene-vinyl acetate, 85 parts of ethylene-octene copolymer, 35 parts of calcined modified kaolin, 12 parts of liquid ethylene propylene rubber, 0.45 parts of titanate coupling agent, 5 parts of 4,4'-di(phenylisopropyl)diphenylamine, 5 parts of pentaerythritol tetra(3-lauryl thiopropionate), 4 parts of 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 19 parts of titanium dioxide, 25 parts of indirect zinc oxide, 15 parts of stearic acid, 1.4 parts of microcrystalline wax, 11 parts of talc, 2 parts of triallyl isocyanurate, and 4.8 parts of dicumyl peroxide.

[0180] The liquid ethylene propylene rubber has a weight-average molecular weight of 25,000 and an ethylene structural unit content of 55 wt%; the microcrystalline wax has a melting point of 68℃ and a kinematic viscosity (100℃) of 7 mm. 2 / s; the particle size of calcined modified kaolin is 8000 mesh; the mass content of vinyl acetate in ethylene-acetic acid acetate is 26%, the melt flow rate (190℃, 2.16kg) is 4g / 10min, and the melting point is 76℃; the melt flow rate (190℃, 2.16kg) of ethylene-octene copolymer is 0.5g / 10min, the Mooney viscosity (ML 1+4, 121℃) is 36, and the melting point is 45℃; the particle size of talc is 2500 mesh; the penetration (25℃) of microcrystalline wax is 14 (mm / 10).

[0181] (2) Prepare insulating rubber according to the following process:

[0182] S10, ethylene-vinyl acetate and ethylene-octene copolymer are mixed to obtain the first mixture;

[0183] S20. Add antioxidant, indirect zinc oxide, stearic acid and microcrystalline wax to the first mixture, and knead to obtain the second mixture;

[0184] S30. Add liquid ethylene propylene rubber, coupling agent, calcined modified kaolin, titanium dioxide and talc to the second mixture, and mix to obtain a rubber matrix.

[0185] S40. Add vulcanizing agent and vulcanizing agent to rubber matrix, and then mix, filter (a filter screen is installed in front of the honeycomb plate at the head of the filter press, and the filter screen combination is 40 mesh + 100 mesh + 80 mesh) and roll into sheets to prepare insulating rubber.

[0186] Examples 2-6, Comparative Examples 1-7

[0187] The preparation methods are basically the same as those in Example 1, except that the raw materials are different. Specifically, the raw materials for preparing the insulating rubber in Examples 2 to 6 are shown in Table 1; the raw materials for preparing the insulating rubber in Comparative Examples 1 to 7 are shown in Table 2.

[0188] Table 1

[0189]

[0190] Table 2

[0191]

[0192] The performance of the insulating rubbers prepared in each embodiment and comparative example was tested according to the industry standards recorded in Table 3.

[0193] Table 3

[0194]

[0195] The performance results of the insulating rubbers prepared in Examples 1 to 5 are shown in Table 4; the performance results of the insulating rubbers prepared in Comparative Examples 1 to 7 are shown in Table 5.

[0196] Table 4

[0197]

[0198] Table 5

[0199]

[0200] As shown in the table above, the insulating rubbers of Examples 1 to 6 are prepared from specific parts and types of raw materials, and have excellent high-temperature aging resistance, mechanical properties and electrical insulation properties; they can be used for 25 years or more under environmental conditions of 105°C.

[0201] Compared with Example 1, the difference between Comparative Example 1 and Comparative Example 2 lies in the mass parts of ethylene-vinyl acetate and ethylene-octene copolymer. In Comparative Example 1, the amount of ethylene-vinyl acetate was 25 parts and the amount of ethylene-octene copolymer was only 75 parts, resulting in a significant reduction in the electrical insulation performance and a significant shortening of the high-temperature service life of the final insulating rubber. In Comparative Example 2, the amount of ethylene-vinyl acetate was only 5 parts and the amount of ethylene-octene copolymer was 95 parts, resulting in a decrease in the mechanical properties of the final insulating rubber, a shortening of the high-temperature service life, and a rough surface.

[0202] In Comparative Example 3, only 9 parts of antioxidant were used, resulting in decreased mechanical properties and a shortened high-temperature service life of the final insulating rubber. In Comparative Example 4, 21 parts of antioxidant were used, resulting in surface blooming of the final insulating rubber.

[0203] In Comparative Example 5, replacing an equal mass of liquid ethylene propylene rubber with paraffin oil resulted in a decrease in the mechanical properties, electrical insulation properties, and high-temperature service life of the final insulating rubber. In Comparative Example 6, using only 2 parts of titanium dioxide resulted in a decrease in the mechanical properties, electrical insulation properties, and high-temperature service life of the final insulating rubber. In Comparative Example 7, using only 5 parts of indirect zinc oxide resulted in a decrease in the mechanical properties, electrical insulation properties, and high-temperature service life of the final insulating rubber.

[0204] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0205] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A high-temperature resistant insulating rubber, characterized in that, By mass, the preparation materials include the following: 10-20 parts of ethylene-vinyl acetate 85-100 parts of ethylene-octene copolymer 30-50 parts of calcined modified kaolin 10-15 parts of liquid ethylene propylene rubber Coupling agent 0.3~0.6 parts, Anti-aging agent 10-15 parts 15-20 parts of titanium dioxide Indirect method zinc oxide 20-30 parts 1-2 parts stearic acid 1-2 parts of microcrystalline wax 10-15 parts talcum powder 2-4 parts of vulcanizing agent 2-6 parts of vulcanizing agent.

2. The high temperature resistant insulating rubber according to claim 1, wherein, The mass ratio of the ethylene-vinyl acetate to the ethylene-octene copolymer is 1:(5~7).

3. The high temperature resistant insulating rubber according to any one of claims 1 to 2, characterized in that, The high-temperature resistant insulating rubber satisfies at least one of the following characteristics: (1) The vinyl acetate content in the ethylene-vinyl acetate is 18%~30% by mass; (2) Under the conditions of 190℃ and 2.16kg pressure, the melt flow rate of the ethylene-vinyl acetate is 2g / 10min~4g / 10min; (3) The melting point of the ethylene-vinyl acetate is 60℃~80℃.

4. The high temperature resistant insulating rubber according to any one of claims 1 to 2, characterized in that, The high-temperature resistant insulating rubber satisfies at least one of the following characteristics: (1) Under the conditions of 190℃ and 2.16kg pressure, the melt flow rate of the ethylene-octene copolymer is 0.2g / 10min~1g / 10min; (2) Under the conditions of ML 1+4 and 121℃, the Mooney viscosity of the ethylene-octene copolymer is 30~40; (3) The melting point of the ethylene-octene copolymer is 40℃~50℃.

5. The high-temperature resistant insulating rubber according to any one of claims 1 to 2, characterized in that, The high-temperature resistant insulating rubber satisfies at least one of the following characteristics: (1) The particle size of the calcined modified kaolin is 6000 mesh to 10000 mesh; (2) The modifier of the calcined modified kaolin is a titanate coupling agent.

6. The high temperature resistant insulating rubber according to any one of claims 1 to 2, wherein The high-temperature resistant insulating rubber satisfies at least one of the following characteristics: (1) The weight-average molecular weight of the liquid ethylene propylene rubber is 10,000 to 30,000; (2) The mass content of ethylene structural units in the liquid ethylene propylene rubber is 45%~55%.

7. The high temperature resistant insulating rubber according to any one of claims 1 to 2, wherein The high-temperature resistant insulating rubber satisfies at least one of the following characteristics: (1) The coupling agent includes one or both of titanate coupling agents and aluminate coupling agents; (2) The antioxidant includes one or more of 4,4'-di(phenylisopropyl)diphenylamine, pentaerythritol tetra(3-lauryl thiopropionate) and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; (3) The co-vulcanizing agent includes one or more of triallyl isocyanurate and N,N'-m-phenylene-bismaleimide; (4) The vulcanizing agent includes one or more of 1,4-di-tert-butylperoxyisopropylbenzene and dicumyl peroxide; (5) The titanium dioxide includes rutile titanium dioxide; (6) The zinc oxide content in the indirect zinc oxide process is ≥99.7% by mass; (7) The particle size of the talc powder is 2000 mesh to 3000 mesh.

8. The high temperature resistant insulating rubber according to any one of claims 1 to 2, wherein The high-temperature resistant insulating rubber satisfies at least one of the following characteristics: (1) The melting point of the microcrystalline wax is 65℃~70℃; (2) the kinematic viscosity of the microcrystalline wax at 100°C is 6 mm 2 / s~8 mm 2 / s; (3) At 25°C, the penetration of the microcrystalline wax is 10 (mm / 10) to 15 (mm / 10).

9. A process for the preparation of a high temperature resistant insulating rubber, characterized in that, Includes the following steps: The raw materials for preparing the high-temperature resistant insulating rubber according to any one of claims 1 to 8 are provided, and the raw materials are mixed to prepare the insulating rubber.

10. The application of the high-temperature resistant insulating rubber as described in any one of claims 1 to 8 or the high-temperature resistant insulating rubber prepared by the preparation method described in claim 9 in the preparation of power transmission products.

11. A cable, characterized in that, This includes the high-temperature resistant insulating rubber according to any one of claims 1 to 8 or the high-temperature resistant insulating rubber prepared by the preparation method according to claim 10.

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