阅读说明：本技术 高压电缆绝缘材料及其制备方法和应用 (High-voltage cable insulating material and preparation method and application thereof ) 是由 刘敬锐 李秀娟 张斌 刘美兵 帅选阳 陈文卿 于 2019-03-01 设计创作，主要内容包括：本发明提供一种高压电缆绝缘材料及其制备方法和应用。所述高压电缆绝缘材料,以重量份计,包括：低密度聚乙烯：100份；抗氧剂：0.1～0.3份,优选0.15-0.20份；交联剂：1.0～2.0份,优选1.0-1.5份；聚丁二烯类助剂：0.5～5.0份,优选0.5-2.0份；高分子材料添加剂：0.5～10.0份,优选.0.5-5.0份。本发明的高压电缆绝缘材料的综合绝缘性能优异；本发明的高压电缆绝缘材料,具有优良的击穿强度稳定性,同时获得优良的抗水树效果,可明显提高材料的长期使用稳定性。进一步地,本发明的高压电缆绝缘材料的制备方法,可大量降低交联剂的使用量,具有更低的加工能耗,有效降低成本,适合工业长时间稳定生产,间接缩短脱气时间。(The invention provides a high-voltage cable insulating material and a preparation method and application thereof. The high-voltage cable insulating material comprises the following components in parts by weight: low density polyethylene: 100 parts of (A); antioxidant: 0.1-0.3 part, preferably 0.15-0.20 part; a crosslinking agent: 1.0-2.0 parts, preferably 1.0-1.5 parts; polybutadiene auxiliaries: 0.5-5.0 parts, preferably 0.5-2.0 parts; high polymer material additive: 0.5-10.0 parts, preferably 0.5-5.0 parts. The high-voltage cable insulating material has excellent comprehensive insulating property; the high-voltage cable insulating material has excellent breakdown strength stability, obtains excellent water tree resistance effect and can obviously improve the long-term use stability of the material. Furthermore, the preparation method of the high-voltage cable insulating material can greatly reduce the usage amount of the cross-linking agent, has lower processing energy consumption, effectively reduces the cost, is suitable for industrial long-time stable production, and indirectly shortens the degassing time.)

1. A high-voltage cable insulation material is characterized by comprising the following components in parts by weight:

low density polyethylene: 100 parts of (A);

antioxidant: 0.1-0.3 part, preferably 0.15-0.20 part;

a crosslinking agent: 1.0-2.0 parts, preferably 1.0-1.5 parts;

polybutadiene auxiliaries: 0.5-5.0 parts, preferably 0.5-2.0 parts;

high polymer material additive: 0.5-10.0 parts, preferably 0.5-5.0 parts.

2. The high-voltage cable insulating material is characterized by comprising the following components in parts by weight:

low density polyethylene: 100 parts of (A);

antioxidant: 0.1-0.3 part, preferably 0.15-0.20 part;

a crosslinking agent: 1.0-2.0 parts, preferably 1.0-1.5 parts;

polybutadiene auxiliaries: 0.5-5.0 parts, preferably 0.5-2.0 parts;

high polymer material additive: 0.5-10.0 parts, preferably 0.5-5.0 parts.

3. The high-voltage cable insulation material as claimed in claim 1 or 2, wherein the polybutadiene-based assistant comprises: one or the combination of more than two of liquid polybutadiene, hydroxyl-terminated liquid polybutadiene and maleic anhydride functionalized liquid polybutadiene.

4. A high voltage cable insulation according to any of claims 1-3, wherein the polymeric material additive comprises: one or more of linear low density polyethylene, medium density polyethylene, high density polyethylene, random copolymerization polypropylene, isotactic polypropylene and syndiotactic polypropylene.

5. The high voltage cable insulation of any one of claims 1-4, wherein the antioxidant comprises one or more of 1, 2-bis [ β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionyl ] hydrazine, pentaerythrityl tetrakis [ β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], 4' -thiobis (6-t-butyl-3-methylphenol), distearyl thiodipropionate, and dilauryl thiodipropionate.

6. A high voltage cable insulation according to any of claims 1-5, characterized in that the crosslinking agent comprises a peroxide crosslinking agent, preferably bis (1-methyl-1-phenylethyl) peroxide.

7. The high-voltage cable insulating material as claimed in any one of claims 1 to 6, wherein the mass ratio of the polybutadiene auxiliary agent to the polymer material additive is 1:2 to 2: 1.

8. A method for preparing a high voltage cable insulation according to any of claims 1-7, comprising: a step of mixing the components of the high voltage cable insulation material.

9. The method for preparing a high voltage cable insulation material according to claim 8, comprising the steps of:

melting and blending low-density polyethylene, an antioxidant, a polybutadiene auxiliary agent and a high polymer material additive, and then cooling and granulating to obtain particles;

and mixing and absorbing the particles and the cross-linking agent to obtain the high-voltage cable insulating material.

10. A cable comprising a high voltage cable insulation according to any of claims 1-7.

Technical Field

The invention relates to a high-voltage cable insulating material and a preparation method and application thereof, belonging to the technical field of insulating material processing.

Background

The existing insulation material for power cables in China mostly adopts Low Density Polyethylene (LDPE) as a base material, and is added with a certain antioxidant and a certain crosslinking agent. The temperature-resistant grade of the non-crosslinked polyethylene is low, the long-time use requirement of the high-voltage power cable at a high temperature for a long time cannot be met, and the temperature-resistant grade of the high-voltage power cable is improved by adding the crosslinking agent to change the crosslinking of the LDPE into crosslinked polyethylene (XLPE).

However, the insulation material for high voltage power cables commonly used at present has the following problems: the degassing time of the crosslinked polyethylene is too long, and small molecular precipitates are easy to appear if the degassing is insufficient, so that the potential hazard is brought to the long-term operation safety of the high-voltage cable. Meanwhile, the water tree resistance of the crosslinked polyethylene is poor, and the long-term service life of the cable is short.

Patent document CN108623877A discloses an insulating material for high voltage dc cables with low cross-linking agent content and high cross-linking degree, which effectively reduces thermal elongation by adding an auxiliary cross-linking agent to reduce the cross-linking agent content, but only analyzes the thermal elongation properties of the material, and other dielectric properties and conventional mechanical properties are not described.

Disclosure of Invention

Problems to be solved by the invention

In view of the technical problems in the prior art, the invention firstly provides a high-voltage cable insulating material which has the advantages of excellent water tree resistance, long service life, less byproducts, scorch resistance and stable processing performance.

Furthermore, the invention also provides a preparation method of the high-voltage cable insulating material, which has the advantages of easily obtained raw materials and simple preparation method.

Means for solving the problems

The invention provides a high-voltage cable insulating material which comprises the following components in parts by weight:

low density polyethylene: 100 parts of (A);

antioxidant: 0.1-0.3 part, preferably 0.15-0.20 part;

a crosslinking agent: 1.0-2.0 parts, preferably 1.0-1.5 parts;

polybutadiene auxiliaries: 0.5-5.0 parts, preferably 0.5-2.0 parts;

high polymer material additive: 0.5-10.0 parts, preferably 0.5-5.0 parts.

The invention also provides a high-voltage cable insulating material which comprises the following components in parts by weight:

low density polyethylene: 100 parts of (A);

antioxidant: 0.1-0.3 part, preferably 0.15-0.20 part;

a crosslinking agent: 1.0-2.0 parts, preferably 1.0-1.5 parts;

polybutadiene auxiliaries: 0.5-5.0 parts, preferably 0.5-2.0 parts;

high polymer material additive: 0.5-10.0 parts, preferably 0.5-5.0 parts.

According to the high-voltage cable insulating material, the polybutadiene auxiliary agent comprises: one or the combination of more than two of liquid polybutadiene, hydroxyl-terminated liquid polybutadiene and maleic anhydride functionalized liquid polybutadiene.

The high-voltage cable insulation material comprises the following high-molecular material additives: one or more of linear low density polyethylene, medium density polyethylene, high density polyethylene, random copolymerization polypropylene, isotactic polypropylene and syndiotactic polypropylene.

According to the high-voltage cable insulation material, the antioxidant comprises one or more of 1, 2-bis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine, pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 4' -thiobis (6-tert-butyl-3-methylphenol), distearyl thiodipropionate and dilauryl thiodipropionate.

The high voltage cable insulation according to the invention, wherein the crosslinking agent comprises a peroxide crosslinking agent, preferably bis (1-methyl-1-phenylethyl) peroxide.

According to the high-voltage cable insulating material, the mass ratio of the polybutadiene auxiliary agent to the high-molecular material additive is 1: 2-2: 1.

The invention also provides a preparation method of the high-voltage cable insulating material, which comprises the following steps: a step of mixing the components of the high voltage cable insulation material.

The preparation method of the high-voltage cable insulating material comprises the following steps:

melting and blending low-density polyethylene, an antioxidant, a polybutadiene auxiliary agent and a high polymer material additive, and then cooling and granulating to obtain particles;

and mixing and absorbing the particles and the cross-linking agent to obtain the high-voltage cable insulating material.

The invention also provides a cable comprising the high-voltage cable insulating material.

ADVANTAGEOUS EFFECTS OF INVENTION

The high-voltage cable insulating material has excellent comprehensive insulating property;

furthermore, the high-voltage cable insulating material has excellent breakdown strength stability, obtains an excellent water tree resistance effect and can obviously improve the long-term use stability of the material.

Furthermore, the preparation method of the high-voltage cable insulating material has higher safety and lower cost, and is suitable for industrial large-scale production.

Furthermore, the preparation method of the high-voltage cable insulating material can greatly reduce the usage amount of the cross-linking agent, has lower processing energy consumption, effectively reduces the cost, is suitable for industrial long-time stable production, and indirectly shortens the degassing time.

Drawings

FIG. 1 is a schematic diagram of a generating device for accelerated water tree aging test according to an embodiment of the present invention, wherein the radius of curvature of the steel needle is 10 μm.

Detailed Description

Various exemplary embodiments, features and aspects of the invention will be described in detail below. The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In other instances, methods, means, devices and steps which are well known to those skilled in the art have not been described in detail so as not to obscure the invention.

All units used in the present invention are international standard units unless otherwise stated, and numerical values and numerical ranges appearing in the present invention should be understood to include systematic errors inevitable in industrial production.

The invention firstly provides a high-voltage cable insulating material, which comprises the following components in parts by weight:

low density polyethylene: 100 parts of (A);

antioxidant: 0.1-0.3 part, preferably 0.15-0.20 part;

a crosslinking agent: 1.0-2.0 parts, preferably 1.0-1.5 parts;

polybutadiene auxiliaries: 0.5-5.0 parts, preferably 0.5-2.0 parts;

high polymer material additive: 0.5-10.0 parts, preferably 0.5-5.0 parts.

Preferably, the invention also provides a high-voltage cable insulating material which comprises the following components in parts by weight:

low density polyethylene: 100 parts of (A);

antioxidant: 0.1-0.3 part, 0.15-0.2 part;

a crosslinking agent: 1.0-2.0 parts and 1.0-1.5 parts;

polybutadiene auxiliaries: 0.5-5.0 parts and 0.5-2.0 parts;

high polymer material additive: 0.5 to 10.0 parts by weight and 0.5 to 5.0 parts by weight.

The high-voltage cable insulating material is an environment-friendly ultra-clean insulating material for high-voltage power cables, and has excellent comprehensive insulating property. The high-voltage cable insulating material can greatly reduce the usage amount of the cross-linking agent, has lower processing energy consumption, effectively reduces the cost, is suitable for industrial long-time stable production, and indirectly shortens the degassing time. Furthermore, the high-voltage cable insulating material has the characteristics of excellent comprehensive performance such as excellent water tree resistance, long service life, few byproducts, scorch resistance, stable long-term processing performance and the like.

In the present invention, Low Density Polyethylene (LDPE) is a conventional high voltage insulation base material having a density of 0.918-0.923g/cm³Preferably, the density is 0.920 to 0.922g/cm³(ii) a The melt index is 1.9-2.1g/10min, and the melting point is 103-111 ℃.

In the present invention, the polybutadiene-based additive may be a liquid additive, and preferably, the polybutadiene-based additive has a viscosity of 1000-7000mPa · s. The invention can improve the water tree resistance of the high-voltage cable insulating material by adding the polybutadiene auxiliary agent. In the present invention, the polybutadiene-based additive is added in an amount of 0.5 to 5.0 parts by weight, preferably 0.5 to 2.0 parts by weight. When the addition amount of the polybutadiene auxiliary agent is 0.5-5.0 parts, the water tree resistance of the high-voltage cable insulating material can be effectively improved.

Preferably, the polybutadiene auxiliary agent comprises: one or the combination of more than two of liquid polybutadiene, hydroxyl-terminated liquid polybutadiene and maleic anhydride functionalized liquid polybutadiene. Among them, Liquid Polybutadiene (LPB), also called low molecular polybutadiene, is low molecular weight polybutadiene and belongs to liquid rubber without functional group. Hydroxyl-terminated liquid polybutadiene generally refers to a homopolymer or copolymer of butadiene having at least one hydroxyl group at one of the two ends of each macromolecule; among these, the copolymer includes butadiene-styrene copolymer, butadiene-propionitrile copolymer, and the like. Maleic anhydride functionalized liquid polybutadiene is an addition derivative of polybutadiene with maleic anhydride.

By using the high polymer material additive, the crystallization performance of the material can be improved, and the high-voltage insulation performance (the breakdown strength value with the cumulative failure probability of 63.2%) and the reliability of the breakdown strength (the data dispersibility of the breakdown strength) are excellent.

For the reliability of high-voltage insulation performance and breakdown strength, the microscopic performance of the insulation material can be analyzed, and the double-parameter distribution Weibull statistical analysis is carried out by testing a certain amount of breakdown data. The scale parameter can be expressed as a breakdown strength value with the cumulative failure probability of 63.2%, and represents the average breakdown performance of the whole material. The larger the numerical value of the scale parameter is, the higher the breakdown strength is, and the more excellent the high-voltage insulation performance is; the shape parameter may indicate the dispersion of the breakdown strength. The larger the value of the shape parameter, the more concentrated the data dispersion of the breakdown strength, i.e., the more excellent the reliability of the breakdown strength.

In the present invention, the polymer material additive includes: linear Low Density Polyethylene (LLDPE), Medium Density Polyethylene (MDPE), High Density Polyethylene (HDPE), random copolymerization polypropylene (PPR), isotactic polypropylene (iPP), and syndiotactic polypropylene (sPP), or a combination of two or more thereof. The addition amount of the polymer material additive is 0.5-10.0 parts by weight, preferably 0.5-5.0 parts by weight. When the addition amount of the high polymer material additive is 0.5-10.0 parts, excellent high-voltage insulation performance can be obtained on the premise of excellent reliability of breakdown strength. For example, the polymeric material additive may be added in an amount of 1 part, 2 parts, 3 parts, 4 parts, 6 parts, 7 parts, 8 parts, 9 parts, etc.

In the invention, the mass ratio of the polybutadiene auxiliary agent to the polymer material additive is 1: 2-2: 1, for example: may be 1:1.8, 1:1.5, 1:1.2, 1:1, 1.2:1, 1.5:1, 1.8:1, etc. When the mass ratio of the polybutadiene additive to the polymer material additive is 1: 2-2: 1, the high-voltage cable insulating material disclosed by the invention can obtain excellent high-voltage insulating performance on the premise of excellent reliability of breakdown strength, and has excellent water tree resistance.

The antioxidant comprises one or more than two of 1, 2-bis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine, tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 4' -thiobis (6-tert-butyl-3-methylphenol), distearyl thiodipropionate and dilauryl thiodipropionate. In the invention, the addition amount of the antioxidant can be 0.1-0.3 part by weight, preferably 0.15-0.2 part by weight. For example: the amount of the antioxidant added may be 0.12 parts, 0.18 parts, 0.25 parts, etc.

In the present invention, the crosslinking agent comprises a peroxide crosslinking agent, preferably comprising bis (1-methyl-1-phenylethyl) peroxide. The addition amount of the cross-linking agent is 1.0-2.0 parts by weight, preferably 1.0-1.5 parts by weight, such as: the amount of the crosslinking agent added may be 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.6 parts, 1.8 parts, etc.

The raw materials and the auxiliary agents are all high-purity and above products.

In general, the specific results of the size and content of impurities of the high voltage cable insulation material can be shown in the following table a:

TABLE A

In each kilogram of the high-voltage cable insulating material, the number of impurities with the diameter d of more than or equal to 100 mu m can be 0; the number of impurities having a diameter d of 70 μm or more and less than 100 μm may be 0 as well.

The invention also provides a preparation method of the high-voltage cable insulating material, which comprises the step of mixing the components of the high-voltage cable insulating material.

Specifically, the preparation method of the high-voltage cable insulating material comprises the following steps:

melting and blending low-density polyethylene, an antioxidant, a polybutadiene auxiliary agent and a high polymer material additive, and then cooling and granulating to obtain particles;

and mixing the particles with the cross-linking agent and uniformly absorbing to obtain the high-voltage cable insulating material.

Further, the preparation method of the high-voltage cable insulation material comprises the following steps:

step 1: melting and blending low-density polyethylene, an antioxidant, a polybutadiene auxiliary agent and a high polymer material additive, and then cooling and granulating to obtain particles; wherein the melt blending apparatus comprises: internal mixers, twin-screw extruders, single-screw reciprocating extruders; the temperature of the melt blending process is 130-200 ℃.

Step 2: and mixing the particles with the cross-linking agent, uniformly absorbing for more than 16h at a constant temperature of 60-80 ℃ to obtain the high-voltage cable insulating material.

Air and environment cleanliness meet the necessary production conditions of the high-voltage cable insulating material.