Epoxy resin-based high electrical strength composite insulation material and its preparation method and application

Abstract

The present invention provides an epoxy resin-based high-electrical-strength composite insulating material, its preparation method, and its application, belonging to the technical field of insulating materials. The present invention comprises an epoxy resin matrix and an organic small molecule filler; in parts by weight, the epoxy resin matrix includes 100 parts of liquid epoxy resin, 80 parts of liquid curing agent, and 1 part of liquid accelerator, and 0.19 to 5.6 parts of the organic small molecule filler. The organic small molecule filler is used instead of a traditional inorganic filler and is blended with the epoxy resin matrix to produce a composite insulating material with good compatibility with the matrix, low filler content, and high electrical strength. Application of this composite insulating material to power equipment can reduce design difficulty and production costs.

Description

Technical Field

[0001] The present invention relates to the technical field of insulating materials, and in particular to an epoxy resin-based high-electrical-strength composite insulating material, a preparation method thereof, and applications of the composite insulating material in power equipment, particularly in dry-type transformers, pot-type insulators, and bushings. Background Art

[0002] Epoxy resins, with their excellent electrical insulation properties, are widely used in power equipment such as dry-type transformers, pot-type insulators, and bushings. High-electrical-strength epoxy resins can reduce the design complexity and economical cost of electrical insulation structures, making them key to the development of high-voltage power equipment. Existing research has shown that adding an appropriate amount of micron or nanometer-sized inorganic fillers to an epoxy resin matrix can improve the electrical strength of epoxy resin-based composite insulation materials. Commonly used inorganic fillers include silica, alumina, magnesium oxide, and titanium dioxide. However, the surface of most inorganic filler particles is hydrophilic, while the epoxy resin matrix molecules are hydrophobic, resulting in poor compatibility between the inorganic filler and the epoxy resin matrix. Typically, surface modification of the inorganic filler with a surface modifier such as a silane coupling agent can improve compatibility between the inorganic filler and the epoxy resin matrix. However, the dosage and application of the surface modifier have long been technical challenges. Excessive or excessive amounts of surface modifier not only hinder the compatibility between the inorganic filler and the polymer matrix but can even reduce the electrical strength of the composite insulation material. In addition, in order to obtain higher electrical strength, the content of inorganic fillers in composite insulation materials is usually very high, which will increase the viscosity of the epoxy resin-based composite insulation material mixture before molding, which is not conducive to the casting and processing of the composite insulation material. Summary of the Invention

[0003] In view of this, in order to solve the technical problems in the prior art such as poor compatibility between inorganic fillers and epoxy resin matrices, surface modifiers that are not only not conducive to improving the compatibility between inorganic fillers and polymer matrices but may even reduce the electrical strength of composite insulating materials, and difficulties in processing epoxy resin-based composite materials caused by high inorganic filler content, the present invention provides an epoxy resin-based high electrical strength composite insulating material, which uses organic small molecule fillers instead of traditional inorganic fillers, has good compatibility with the matrix, low filler content and high electrical strength.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An epoxy resin-based high electrical strength composite insulating material, consisting of an epoxy resin matrix and organic small molecule fillers;

[0006] In parts by weight, the epoxy resin matrix comprises 100 parts of liquid epoxy resin, 80 parts of liquid curing agent and 1 part of liquid accelerator;

[0007] The weight portion of the organic small molecule filler is 0.19 to 5.6 parts.

[0008] Preferably, the weight portion of the organic small molecule filler is 1.9 to 5.6 parts.

[0009] Preferably, the weight portion of the organic small molecule filler is 5.6 parts.

[0010] Preferably, the organic small molecule filler is allyloxy polyoxyethylene ether.

[0011] Preferably, the liquid curing agent is methylphthalic anhydride.

[0012] Preferably, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0013] On the other hand, the present invention provides a method for preparing the above-mentioned epoxy resin-based high electrical strength composite insulating material, wherein the organic small molecule filler is blended with the epoxy resin matrix to obtain the composite insulating material.

[0014] Preferably, the method specifically includes the following steps:

[0015] 1) weighing the liquid epoxy resin, the liquid curing agent, the accelerator and the organic small molecule filler for later use;

[0016] 2) mixing the epoxy resin and the organic small molecule at 50-60° C. for 10-15 minutes, adding the curing agent and the accelerator, and continuing to mix at 50-60° C. for 20-30 minutes;

[0017] 3) The mixed solution of step 2) is vacuum degassed for 15 to 30 minutes, injected into a mold, and pre-cured at 80 to 90° C. for 3 to 5 hours, and then post-cured at 110 to 130° C. for 7 to 9 hours. After the mold is cooled to room temperature, an epoxy resin-based high-electricity composite insulating material can be obtained.

[0018] In another aspect, the present invention further provides the use of the composite insulating material or the composite insulating material prepared by the above preparation method in electric power equipment.

[0019] Preferably, the power equipment includes a dry-type transformer, a pot-type insulator and a bushing.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The epoxy resin-based high electrical strength composite insulating material provided by the present invention, as well as its preparation method and application, uses allyloxy polyoxyethylene ether as an organic small molecule filler. Since allyloxy polyoxyethylene ether has similar functional groups (such as hydroxyl groups) as the epoxy resin matrix molecules, the organic small molecule filler has good compatibility with the epoxy resin matrix.

[0022] The filler used has a low content and high electrical strength, and has almost no effect on the viscosity of the epoxy resin-based composite insulation material mixture before molding, which is beneficial to the casting molding of the composite insulation material;

[0023] Epoxy resin-based composite insulation materials with high electrical strength help reduce the design difficulty and production cost of power equipment such as dry-type transformers and pot-type insulators. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The relationship between the electrical strength and the filler content in Examples 1-5 and Comparative Examples 1-3. DETAILED DESCRIPTION

[0025] The present invention provides an epoxy resin-based high electrical strength composite insulating material, which is composed of an epoxy resin matrix and an organic small molecule filler;

[0026] In parts by weight, the epoxy resin matrix comprises 100 parts of liquid epoxy resin, 80 parts of liquid curing agent and 1 part of liquid accelerator;

[0027] The weight portion of the organic small molecule filler is 0.19 to 5.6 parts, preferably 1.9 to 5.6 parts, and more preferably 5.6 parts.

[0028] In the present invention, the organic small molecule filler is preferably allyloxy polyoxyethylene ether, which has similar functional groups (such as hydroxyl groups) to the epoxy resin matrix molecule, so the organic small molecule filler has good compatibility with the epoxy resin matrix.

[0029] In the present invention, the liquid curing agent is methylphthalic anhydride.

[0030] In the present invention, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0031] The present invention also provides a method for preparing the epoxy resin-based high electrical strength composite insulating material, wherein the epoxy resin-based high electrical strength composite insulating material is obtained by blending an organic small molecule filler with an epoxy matrix.

[0032] The specific steps include:

[0033] 1) weighing the liquid epoxy resin, the liquid curing agent, the accelerator and the organic small molecule filler for later use;

[0034] 2) mixing the epoxy resin and the organic small molecule at 50-60° C. for 10-15 minutes, adding the curing agent and the accelerator, and continuing to mix at 50-60° C. for 20-30 minutes;

[0035] 3) The mixed solution of step 2) is vacuum degassed for 15 to 30 minutes, injected into a mold, and pre-cured at 80 to 90° C. for 3 to 5 hours, and then post-cured at 110 to 130° C. for 7 to 9 hours. After the mold is cooled to room temperature, an epoxy resin-based high-electricity composite insulating material can be obtained.

[0036] In another aspect, the present invention further provides the use of the composite insulating material or the composite insulating material prepared by the above preparation method in electric power equipment.

[0037] In the present invention, the power equipment includes a dry-type transformer, a pot-type insulator and a bushing.

[0038] The composite insulating material of the present invention helps to reduce the design difficulty and production cost of power equipment such as dry-type transformers and pot-type insulators.

[0039] The technical solution of the present invention is described in detail below with reference to specific embodiments.

[0040] In view of the small difference between temperature and time in the preparation method, the values ​​near the end values ​​were selected for the experiment.

[0041] Example 1

[0042] 1) Weigh 100 g of liquid epoxy resin, 80 g of liquid curing agent, 1 g of accelerator, and 0.19 g of organic small molecule filler in parts by weight;

[0043] 2) mixing the liquid epoxy resin and the organic small molecule filler at 56° C. for 12 minutes, adding the liquid curing agent and the accelerator, and continuing to mix at 55° C. for 30 minutes to obtain a mixed solution;

[0044] 3) The mixed solution of step 2) is vacuum degassed for 20 minutes, injected into a mold, and pre-cured at 85° C. for 4 hours, and then post-cured at 120° C. for 8 hours. After the mold is cooled to room temperature, an epoxy resin-based high-electrical composite insulating material is obtained.

[0045] Example 2

[0046] Same as Example 1, except that the weight of the organic small molecule filler is 0.95 g.

[0047] Example 3

[0048] Same as Example 1, except that the weight of the organic small molecule filler is 1.9 g.

[0049] Example 4

[0050] Same as Example 1, except that the weight of the organic small molecule filler is 2.8 g.

[0051] Example 5

[0052] Same as Example 1, except that the weight of the organic small molecule filler is 5.6 g.

[0053] Comparative Example 1

[0054] The preparation method is the same as that of Example 1, except that no small organic molecule filler is added.

[0055] Comparative Example 2

[0056] The preparation method is the same as that of Example 1, except that the filler is nano-silicon oxide (average particle size 40 nm) and weighs 1.9 g.

[0057] Comparative Example 3

[0058] The preparation method is the same as that of Example 1, except that the filler is nano-silicon oxide (average particle size 40 nm) and weighs 5.6 g.

[0059] The composite insulating materials prepared in Examples 1-5 and Comparative Examples 1-3 were placed between ball-ball electrodes to conduct AC electrical strength tests. The electrode system was immersed in insulating oil. The obtained electrical strength and filler content were shown in the attached figure. Figure 1 As shown, the electrical strength of the epoxy / organic small molecule composite insulation materials is higher than that of pure epoxy resin (i.e., Comparative Example 1) and epoxy / silicon oxide composite insulation materials (i.e., Comparative Examples 2 and 3). Compared with Comparative Example 1, the electrical strength of the composite insulation material of Example 5 is the highest, increasing by 11%. Compared with Comparative Example 2, the electrical strength of the composite insulation material of Example 3, which has the same filler content, is increased by 11.7%. Compared with Comparative Example 3, the electrical strength of the composite insulation material of Example 5, which has the same filler content, is increased by 17.5%.

[0060] The above are only preferred specific embodiments of the present invention; however, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of the present invention shall be covered by the scope of protection of the present invention.

Claims

1. An epoxy resin-based high electrical strength composite insulating material, characterized in that: It is composed of epoxy resin matrix and organic small molecule filler; In parts by weight, the epoxy resin matrix comprises 100 parts of liquid epoxy resin, 80 parts of liquid curing agent and 1 part of liquid accelerator; The weight portion of the organic small molecule filler is 0.19 to 5.6 parts; The organic small molecule filler is allyloxy polyoxyethylene ether.

2. The epoxy resin-based high electrical strength composite insulating material according to claim 1, characterized in that: The weight portion of the organic small molecule filler is 1.9 to 5.6 parts.

3. The epoxy resin-based high electrical strength composite insulating material according to claim 1, characterized in that: The weight portion of the organic small molecule filler is 5.6 parts.

4. The epoxy resin-based high electrical strength composite insulating material according to claim 1, characterized in that: The liquid curing agent is methylphthalic anhydride.

5. An epoxy resin-based high electrical strength composite insulating material according to any one of claims 1 to 4, characterized in that: The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

6. A method for preparing an epoxy resin-based high electrical strength composite insulating material according to any one of claims 1 to 5, characterized in that: The specific steps include: 1) Weighing the liquid epoxy resin, the liquid curing agent, the accelerator, and the organic small molecule filler for later use; 2) mixing the epoxy resin and the organic small molecule filler at 50-60° C. for 10-15 minutes, adding a curing agent and an accelerator, and continuing to mix at 50-60° C. for 20-30 minutes to obtain a mixed solution; 3) The mixed solution obtained in step 2) is vacuum degassed for 15 to 30 minutes, injected into a mold, and pre-cured at 80 to 90° C. for 3 to 5 hours, followed by post-curing at 110 to 130° C. for 7 to 9 hours. After the mold is cooled to room temperature, an epoxy resin-based high electrical strength composite insulation material is obtained.

7. Use of the composite insulating material according to any one of claims 1 to 5 or the composite insulating material prepared by the preparation method according to claim 6 in electric power equipment.

8. The use according to claim 7, characterized in that The power equipment includes a dry-type transformer, a pot-type insulator and a bushing.

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