A two-liquid high-voltage resistant epoxy insulating casting resin and preparation method thereof

Abstract

The present invention relates to a two-liquid high-voltage epoxy insulating casting resin and a preparation method, and belongs to the field of insulating epoxy casting resin. The two-liquid high-voltage epoxy insulating casting resin is composed of component A and component B, wherein component A includes: 80-90 parts by weight of epoxy resin, 1-5 parts by weight of polyether polyol, 5-15 parts by weight of toughening agent, 0.1-0.5 parts by weight of defoaming agent and 0.1-0.5 parts by weight of dispersant; component B includes: 80-93 parts by weight of anhydride curing agent, 5-15 parts by weight of toughening agent and 0.2-1.0 parts by weight of accelerator. The two-liquid high-voltage epoxy insulating casting resin has excellent high and low temperature impact resistance, electrical strength and mechanical properties, is easy to operate, and has a rapid increase in glass transition temperature, which can effectively improve production efficiency and is suitable for the equipment and manufacture of high-voltage insulating devices.

Description

Technical Field

[0001] The invention relates to the technical field of insulating epoxy casting resins, in particular to a two-liquid high-voltage resistant epoxy insulating casting resin and a preparation method thereof. Background Art

[0002] With the rapid development of social economy, the demand for electric energy is increasing day by day. The expansion, renewal and replacement of power grids have brought about the replacement demand for a large number of high-voltage components in power transmission and transformation systems. Epoxy insulation casting resin is currently the safest and most reliable insulation solution. With the continuous increase in voltage, the requirements for electrical insulation systems are becoming more and more stringent. The development of large-capacity power generation technology has promoted the increase in power voltage, and has also continuously improved and optimized insulation materials.

[0003] Due to technical limitations, the traditional high-voltage insulating casting resin has problems such as the glass transition temperature of the cured product not meeting the standard. Since the A and B components are basically in the form of solid state at room temperature, high-temperature reaction and chain extension are required during the preparation process, and heating and melting are required during use, which prolongs the manufacturing time and causes energy loss. At the same time, due to the high heating temperature, the product is prone to problems such as bubbles and shrinkage during use. If bubbles appear in the internal device part, it is likely to cause problems such as partial discharge failure of the final product.

[0004] Therefore, how to provide a two-liquid high-voltage resistant epoxy insulating casting resin that is liquid at room temperature and has good electrical properties, high mechanical strength, high glass transition temperature, long gel time, and can be quickly demolded at the glass transition temperature after gel is of great significance and also has certain challenges.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a two-liquid high-voltage resistant epoxy insulating casting resin and a preparation method, which can be in liquid state at room temperature, and has good electrical properties, high mechanical strength, high glass transition temperature, long gel time and rapid increase in glass transition temperature after gel, which is convenient for demolding, thereby solving the above-mentioned technical problems existing in the prior art.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A two-component high-voltage resistant epoxy insulating casting resin, the casting resin is composed of component A and component B, wherein the component A comprises the following raw materials calculated by total weight: 80-90 parts by weight of epoxy resin, 1-5 parts by weight of polyether polyol, 5-15 parts by weight of toughening agent, 0.1-0.5 parts by weight of defoaming agent, and 0.1-0.5 parts by weight of dispersant;

[0009] The B component includes the following raw materials by total weight: 80-93 parts by weight of anhydride curing agent, 5-15 parts by weight of toughening agent, and 0.2-1.0 parts by weight of accelerator;

[0010] The component A and the component B are prepared in a mass ratio of 100:100.

[0011] Furthermore, the epoxy resin in the component A of the casting resin is a low-viscosity, low-hydrolyzable chlorine bisphenol A type epoxy resin.

[0012] Furthermore, in the A component and the B component of the casting resin, the toughening agent is a core-shell toughening material, wherein the core material is a rubber that is insoluble in the component, and the shell material is a plastic that is dispersed into the component. In the production structure of this toughening agent, the shell material can be dispersed into the component, and the core material is insoluble in the component.

[0013] Furthermore, the acid anhydride curing agent in the B component is methyl hexahydrophthalic anhydride.

[0014] A method for preparing the above-mentioned two-liquid high-voltage resistant epoxy insulating casting resin comprises preparing component A and component B respectively, wherein:

[0015] The preparation of component A comprises: according to the formula of component A in the two-component high-voltage epoxy insulating casting resin of the present invention, epoxy resin, polyether polyol, toughening agent, defoaming agent and dispersant in the raw materials required for component A are added into a reaction kettle, mixed for 150 to 180 minutes at 70 to 80° C., stirred evenly and then vacuumed to remove bubbles, and the obtained product is component A of the two-component high-voltage epoxy insulating casting resin;

[0016] The component B of step 1 is as follows: according to the formula of the component B of the two-liquid high-voltage epoxy insulating casting resin of the present invention, the anhydride curing agent, toughening agent and accelerator in the raw materials required for the component B are added into a reaction kettle, mixed for 100 to 120 minutes at 85 to 95° C., stirred evenly, and then vacuumed to remove bubbles, and the obtained product is the component B of the two-liquid high-voltage epoxy insulating casting resin;

[0017] The prepared component A and component B are mixed with glue in a mass ratio of 100:100 to obtain a two-liquid high-voltage resistant epoxy insulating casting resin.

[0018] Compared with the prior art, the two-liquid high-voltage resistant epoxy insulating casting resin and preparation method provided by the present invention have the following beneficial effects:

[0019] (1) By using methyl hexahydrophthalic anhydride as an anhydride curing agent in component B, component B can be kept in a liquid state at room temperature and does not need to be heated to dissolve. At the same time, since methyl hexahydrophthalic anhydride has good post-curing properties and can effectively increase the glass transition temperature of the cured product, component A does not need to be pre-chain extended, thereby ensuring that component A can also remain in a liquid state at room temperature;

[0020] (2) The glass transition temperature of the cured product is the same as or slightly higher than that of traditional solid resins;

[0021] (3) The casting resin does not need to be dissolved in advance before production, and the product viscosity is low at room temperature, the processability is good, it can effectively fill the gap of the insert, and the appearance is beautiful;

[0022] (4) The casting resin has excellent mechanical properties;

[0023] (5) The casting resin has a long gel time, which can effectively release the internal stress caused by the gel process and prevent stress accumulation. At the same time, the glass transition temperature increases rapidly after gelation, which can shorten the overall manufacturing time and save energy. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0025] First, the terms that may be used in this article are explained as follows:

[0026] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0027] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0028] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0029] The term "parts by mass" refers to the mass ratio relationship between multiple components. For example, if it is described that component X is x parts by mass and component Y is y parts by mass, then the mass ratio of component X to component Y is x:y. 1 part by mass can represent any mass, for example, 1 part by mass can be represented as 1 kg or 3.1415926 kg. The sum of the parts by mass of all components is not necessarily 100 parts, but can be greater than 100 parts, less than 100 parts or equal to 100 parts. Unless otherwise specified, the parts, proportions and percentages described herein are all measured by mass.

[0030] When concentration, temperature, pressure, size or other parameters are expressed in the form of a numerical range, the numerical range should be understood to specifically disclose all ranges formed by the pairing of any upper limit, lower limit, and preferred value in the numerical range, regardless of whether the range is explicitly stated; for example, if a numerical range of "2 to 8" is stated, the numerical range should be interpreted as including ranges such as "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", etc. Unless otherwise specified, the numerical ranges stated herein include both their end values ​​and all integers and fractions within the numerical range.

[0031] The scheme provided by the present invention is described in detail below. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professionals in the field. If the specific conditions are not specified in the embodiments of the present invention, they are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers are not specified in the reagents or instruments used in the embodiments of the present invention, they are all conventional products that can be purchased commercially.

[0032] The embodiment of the present invention provides a two-liquid high-voltage resistant epoxy insulating casting resin, which is composed of component A and component B, wherein:

[0033] The A component includes the following raw materials by total weight:

[0034]

[0035] The B component includes the following raw materials by total weight:

[0036] 80 to 93 parts by weight of anhydride curing agent,

[0037] 5 to 15 parts by weight of toughening agent,

[0038] Accelerator 0.2-1.0 parts by weight;

[0039] The acid anhydride curing agent is methyl hexahydrophthalic anhydride;

[0040] The component A and the component B are prepared in a mass ratio of 100:100.

[0041] Preferably, in the above casting resin, the epoxy resin in the A component is a low-viscosity, low-hydrolyzable chlorine bisphenol A type epoxy resin.

[0042] Preferably, in the above casting resin, in the component A and the component B, the toughening agent is a core-shell toughening substance, wherein the core material is a rubber that is insoluble in the component, and the shell material is a plastic that is dispersed into the component.

[0043] The embodiment of the present invention also provides a method for preparing the above-mentioned two-liquid high-voltage epoxy insulating casting resin, comprising preparing component A and component B respectively, wherein:

[0044] The preparation of component A is as follows: taking raw materials according to the formula of component A in the two-component high-voltage epoxy insulating casting resin according to any one of claims 1 to 4, adding the epoxy resin, polyether polyol, toughening agent, defoaming agent and dispersant in the raw materials into a reaction kettle, mixing for 150 to 180 minutes at 70 to 80° C., stirring evenly, and then vacuuming to remove bubbles, and the obtained product is component A of the two-component high-voltage epoxy insulating casting resin;

[0045] The preparation of component B is as follows: taking various raw materials according to the formula of component B in the two-component high-voltage epoxy insulating casting resin according to any one of claims 1 to 4, adding the anhydride curing agent, toughening agent and accelerator in the raw materials into a reaction kettle, mixing for 100 to 120 minutes at 85 to 95° C., stirring evenly, and then vacuuming to remove bubbles, and the obtained product is component B of the two-component high-voltage epoxy insulating casting resin.

[0046] In summary, the two-liquid high-voltage resistant epoxy insulating casting resin of the embodiment of the present invention can ensure that component B is in a liquid state at room temperature by using methyl hexahydrophthalic anhydride as an anhydride curing agent in component B, and does not need to be heated to dissolve. At the same time, since methyl hexahydrophthalic anhydride has good performance after curing, it can effectively improve the glass transition temperature of the cured product, so component A does not need to be pre-chain extended, thereby ensuring that component A can also remain in a liquid state at room temperature; the glass transition temperature of the cured product is the same as or slightly higher than that of traditional solid resins; the casting resin does not need to be dissolved in advance before production, and the product viscosity is low at room temperature, the processability is good, it can effectively fill the insert gap, and the appearance is beautiful; the casting resin has excellent mechanical properties; the casting resin has a long gel time, which can effectively release the internal stress caused by the gel process and prevent stress accumulation. At the same time, the glass transition temperature increases rapidly after gelation, which can shorten the overall manufacturing time and save energy.

[0047] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail with specific embodiments below.

[0048] Example 1

[0049] This embodiment provides a two-component high-voltage resistant epoxy insulating casting resin for casting and protecting high-voltage insulating components, and its preparation method includes:

[0050] Prepare component A and component B separately, wherein:

[0051] Preparation of component A:

[0052] The formula of component A is as follows:

[0053] Table 1 is the formula of component A

[0054] raw material Specific raw material name Weight Epoxy resin Bisphenol A epoxy resin 127E 88 Toughening agent M521 7.6 Polyether polyols DP400 4 Defoaming agent ACP-5500 0.2 Dispersants BYK-2710 0.2

[0055] According to the formula of component A in Table 1 above, the epoxy resin, polyether polyol, toughening agent, defoaming agent and dispersant required for component A are added into a reaction kettle, mixed for 150 minutes at 80° C., stirred evenly and then vacuumed to remove bubbles, and the obtained product is component A of the two-liquid high-voltage epoxy insulation casting resin;

[0056] Preparation of component B:

[0057] The formula of component B is as shown in Table 2:

[0058] Table 2 is the formula of component B

[0059] raw material Specific raw material name Weight Anhydride curing agent Methylhexahydroaniline 89 Accelerator TAMC 0.5 Toughening agent M521 10.5

[0060] According to the formula of component B in Table 2 above, the anhydride curing agent, accelerator and toughening agent required for component B are added into the reaction kettle, mixed at 90° C. for 100 minutes, stirred evenly and then vacuumed to remove bubbles. The obtained product is component B of the two-liquid high-voltage epoxy insulation casting resin.

[0061] Example 2

[0062] This embodiment provides a two-component high-voltage resistant epoxy insulating casting resin, which is used for casting and protecting high-voltage insulating components. The preparation method thereof may include:

[0063] Prepare component A and component B separately, wherein:

[0064] Preparation of component A:

[0065] The formula of component A is as shown in Table 3:

[0066] Table 3 is the formula of component A

[0067] raw material Specific raw material name Weight Epoxy resin Bisphenol A epoxy resin 127E 82 Toughening agent M521 12.5 Polyether polyols DP400 5 Defoaming agent ACP-5500 0.3 Dispersants BYK-2710 0.2

[0068] According to the formula of component A in Table 3 above, the epoxy resin, polyether polyol, toughening agent, defoaming agent and dispersant required for component A are added into a reaction kettle, mixed for 180 minutes at 80° C., stirred evenly and then vacuumed to remove bubbles, and the obtained product is component A of the two-liquid high-voltage epoxy insulation casting resin;

[0069] Preparation of component B:

[0070] The formula of component B is shown in Table 4 below:

[0071] Table 4 is the formula of component B

[0072] raw material Specific raw material name Weight Anhydride curing agent Methylhexahydroaniline 92 Accelerator TAMC 0.3 Toughening agent M521 7.7

[0073] According to the formula of component B in Table 4 above, the anhydride curing agent, accelerator and toughening agent required for component B are added into the reaction kettle, mixed at 85°C for 110 minutes, stirred evenly and then vacuumed to remove bubbles. The obtained product is component B of the two-liquid high-voltage epoxy insulation casting resin.

[0074] Example 3

[0075] This embodiment provides a two-component high-voltage resistant epoxy insulating casting resin, which is used for casting and protecting high-voltage insulating components. The preparation method thereof may include:

[0076] Prepare component A and component B separately, wherein:

[0077] Preparation of component A:

[0078] The formula of component A is as shown in Table 5:

[0079] Table 5 is the formula of component A

[0080] raw material Specific raw material name Weight Epoxy resin Bisphenol A epoxy resin 127E 84 Toughening agent M521 12.3 Polyether polyols DP400 3 Defoaming agent ACP-5500 0.3 Dispersants BYK-2710 0.4

[0081] According to the formula of component A in Table 5 above, the epoxy resin, polyether polyol, toughening agent, defoaming agent and dispersant required for component A are added into a reaction kettle, mixed for 160 minutes at 80° C., stirred evenly and then vacuumed to remove bubbles, and the obtained product is component A of the two-liquid high-voltage epoxy insulation casting resin;

[0082] Preparation of component B:

[0083] The formula of component B is shown in Table 6 below:

[0084] Table 6 is the formula of component B

[0085]

[0086]

[0087] According to the formula of component B in Table 6 above, the anhydride curing agent, accelerator and toughening agent required for component B are added to the reaction kettle, mixed for 120 minutes at 90°C, stirred evenly and then vacuumed to remove bubbles. The obtained product is component B of the two-liquid high-voltage resistant epoxy insulating casting resin.

[0088] Performance Testing

[0089] The following performance tests were performed on the high and low temperature impact resistant two-component epoxy insulating resins prepared in Examples 1, 2 and 3 of the present invention and the high and low temperature impact resistant two-component epoxy insulating resins prepared by the commercially available solid casting resin Huntsman ARALDITE CY5868 / ARADUR5868 (the A / B component combination of the same product, hereinafter referred to as H product):

[0090] (1) Viscosity test: According to GB / T 2794-2022 standard, the viscosity of Example 1, Example 2, Example 3 and the mixture of Product H was tested using a viscometer. The test conditions were: DV2T, 27# rotor, temperature 25°C.

[0091] (2) Glass transition temperature test (hereinafter referred to as Tg): After curing under the respective optimal conditions, the product Tg is tested using DSC in a test temperature range of -20 to 200°C, with a heating rate of 5°C / min, and the test results of the second cycle are taken.

[0092] (3) Gel time test: The gel time of the adhesive mixture is tested using a gelator at a test temperature of 150°C (refer to the actual use process).

[0093] (4) Body tensile strength test: According to the resin casting performance test method of GB / T 2567-2021, the adhesive body samples were prepared under specific thermal curing conditions using the examples and comparative examples, and the tensile strength and elongation at break were tested.

[0094] (5) Coefficient of expansion test (hereinafter referred to as CTE): The coefficient of expansion of the cured adhesive product is tested using a TMA tester. The smaller the CTE, the more stable the product size is during temperature changes.

[0095] (6) High and low temperature cycle test: After removing all bubbles, the A component and the B component are mixed evenly in the correct proportion and poured into the anti-cracking performance test mold. Curing is carried out according to their respective processes. After curing, it is cooled to room temperature. The high and low temperature cycle conditions are set as follows: -40℃ for 8h, 105℃ for 8h, and the cast resin sample is cycled under these high and low temperature conditions. Then the number of debonding or cracking cycles between the cast resin sample and the stainless steel block is recorded.

[0096] (7) Volume resistivity test: According to GB / T 1692-2008 standard, the test samples of Example 1, Example 2, Example 3 and Product H were tested, and their volume resistivity was tested.

[0097] (8) Tg growth rate test: Example 1, Example 2, Example 3 and H product were cured at 150°C, and the Tg of the samples after different curing times was tested. The time when the Tg was basically the same as that after the optimal process curing was recorded.

[0098] The high and low temperature impact resistant two-component casting resin obtained by the above implementation was subjected to performance tests. The results are shown in Table 7 below.

[0099] Table 7 is the casting resin performance test data of each embodiment

[0100]

[0101]

[0102] It can be seen from Table 7 above that compared with product H, Example 1, Example 2, and Example 3 of the present invention have the characteristics of being liquid at room temperature and easy to operate, avoiding the generation of bubbles after pouring, having a more beautiful appearance, relatively high Tg, long gel time and subsequent Tg rising speed, high price resistivity, etc., and can be used more safely.

[0103] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A two-component high-voltage epoxy insulating casting resin, characterized in that: The insulating casting resin is composed of component A and component B, wherein the component A includes the following raw materials by total weight: 80-90 parts by weight of epoxy resin, 1 to 5 parts by weight of polyether polyol, 5 to 15 parts by weight of toughening agent, Defoaming agent 0.1-0.5 parts by weight, Dispersant 0.1-0.5 parts by weight; The B component includes the following raw materials by total weight: 80 to 93 parts by weight of anhydride curing agent, 5 to 15 parts by weight of toughening agent, Accelerator 0.2-1.0 parts by weight; The acid anhydride curing agent is methyl hexahydrophthalic anhydride; The component A and the component B are prepared in a mass ratio of 100:

100.

2. The two-component high-voltage epoxy insulating casting resin according to claim 1 is characterized in that: The epoxy resin in the A component is a low-viscosity, low-hydrolyzed chlorine-free bisphenol A type epoxy resin.

3. The two-component high-voltage resistant epoxy insulating casting resin according to claim 1, characterized in that: In the components A and B, the toughening agent is a core-shell toughening material, wherein the core material is a rubber that is insoluble in the component, and the shell material is a plastic that is dispersed into the component.

4. The two-component high-voltage resistant epoxy insulating casting resin according to claim 1, characterized in that: The acid anhydride curing agent in the B component is methyl hexahydrophthalic anhydride.

5. A method for preparing the two-component high-voltage epoxy insulating casting resin according to any one of claims 1 to 4, characterized in that: The method comprises preparing component A and component B separately, wherein: The preparation of component A comprises: taking various raw materials according to the formula of component A in the two-component high-voltage epoxy insulating casting resin according to any one of claims 1 to 4, adding the epoxy resin, polyether polyol, toughening agent, defoaming agent and dispersant in the raw materials into a reaction kettle, mixing for 150 to 180 minutes at 70 to 80° C., stirring evenly, and then vacuuming to remove bubbles, and the obtained product is component A of the two-component high-voltage epoxy insulating casting resin; The preparation of component B is as follows: taking the raw materials according to the formula of component B in the two-component high-voltage epoxy insulating casting resin according to any one of claims 1 to 4, adding the anhydride curing agent, toughening agent and accelerator in the raw materials into a reaction kettle, mixing for 100 to 120 minutes at 85 to 95° C., stirring evenly, and then vacuuming to remove bubbles, and the obtained product is component B of the two-component high-voltage epoxy insulating casting resin; The prepared component A and component B are mixed with glue in a mass ratio of 100:100 to obtain a two-liquid high-voltage resistant epoxy insulating casting resin.

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