Epoxy resin composition, preparation method and application

Abstract

The invention discloses an epoxy resin composition which comprises a component A and a component B. The component A comprises epoxy resin, and the component B comprises a first curing agent and a second curing agent. The first curing agent is a curing agent containing two reactive hydrogen atoms, and the second curing agent is selected from one of an amine curing agent with the number of reactive hydrogen atoms larger than or equal to 3, a sulfydryl curing agent with the number of reactive hydrogen atoms larger than or equal to 3 or an anhydride curing agent. The first curing agent and the second curing agent form a co-curing system, the molecular structure of the first curing agent only has two reactive hydrogen atoms and only plays a role in chain extension in curing reaction, and the free volume of the area of the first curing agent is larger than that of the curing area of the second curing agent. The first curing agent and the second curing agent with different main chain structure types are selected as a co-curing system, so that the heat resistance, the cracking resistance, the voltage resistance, the mechanical strength and the like can be improved under the condition of improving the electrical insulation property and Tg of the epoxy resin composition.

Description

Technical Field

[0001] The invention relates to the field of materials, and in particular to an epoxy resin composition. Background Art

[0002] Epoxy resin is a polymer containing two or more epoxy groups in its molecular structure. The epoxy groups it contains can react with curing agents (anhydrides, amines, etc.) to form a cross-linked cured product.

[0003] Cable accessories are an essential part of cable connection lines. With the development of high-voltage cross-linked cables in my country, the demand for supporting cable accessories is increasing. The operating environment of high-voltage cable accessories is very harsh. Whether it is the terminal bushing of the GIS system, the stress cone sleeve of the terminal, the transformer end bushing, or the intermediate joint shell, the materials used are required to have high mechanical and physical properties and electrical properties. Epoxy resin, as an electrical insulation material, has good electrical insulation properties, mechanical properties, bonding properties, and corrosion resistance. It also has the advantages of low dielectric loss, low curing shrinkage, low linear expansion coefficient, low water absorption, and good dimensional stability.

[0004] Epoxy resin compositions used for high voltage power insulation must have good thermomechanical properties, electrical insulation, voltage resistance, heat resistance, crack resistance, and mechanical properties. However, it is difficult to take all of these properties into account at the same time. Summary of the invention

[0005] The main object of the present invention is to solve the above problems and provide an epoxy resin composition having excellent electrical insulation, voltage resistance, heat resistance, high and low temperature impact resistance, crack resistance and mechanical strength.

[0006] The above object of the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides an epoxy resin composition comprising a component A and a component B;

[0008] The component A includes epoxy resin; the component B includes a first curing agent and a second curing agent;

[0009] The first curing agent is a curing agent containing two active hydrogens;

[0010] The second curing agent is selected from an amine curing agent with an active hydrogen number of ≥3, a mercapto curing agent with an active hydrogen number of ≥3, or an acid anhydride curing agent.

[0011] In some embodiments of the present application, the epoxy resin includes at least one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin.

[0012] In some embodiments of the present application, the first curing agent includes at least one of a bisphenol hydroxyl curing agent, a dicarboxyl curing agent, a diimine curing agent, a dithiol curing agent, or a curing agent containing any two groups of phenolic hydroxyl, thiol, carboxyl and imine.

[0013] In some embodiments of the present application, the first curing agent is selected from at least one of bisphenol A, hydroquinone and 4.4'-biphenylene glycol, sebacic acid, terephthalic acid, 4.4'-bis-sec-butylaminodiphenylmethane, 4.4'-diacetamidodiphenylmethane, 2-dimercaptoethyl sulfide, and 2,2'-(1,2-ethylenedioxy)bisethylmercaptan.

[0014] In some embodiments of the present application, the amine curing agent having an active hydrogen number ≥ 3 includes at least one of a linear aliphatic amine, an alicyclic amine, and an aromatic amine.

[0015] In some embodiments of the present application, the mercapto curing agent having an active hydrogen number ≥ 3 includes at least one of a linear aliphatic mercapto group, an alicyclic mercapto group, and an aromatic mercapto group.

[0016] In some embodiments of the present application, the anhydride curing agent includes at least one of aromatic anhydride, alicyclic anhydride or linear aliphatic anhydride.

[0017] In some embodiments of the present application, the amine curing agent having an active hydrogen number ≥ 3 is selected from at least one of 4,4'-diaminodiphenylmethane, triethylenetetramine, isophoronediamine, 4,4'-diaminodiphenyl sulfone, polyetheramine, polyesteramine, 4,4'-oxydiphenylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, m-phenylenediamine, o-phenylenediamine and p-phenylenediamine.

[0018] In some embodiments of the present application, the mercapto curing agent having an active hydrogen number ≥ 3 is selected from at least one of trimethylolpropane tris(2-mercaptoacetate), pentaerythritol tetramercaptoacetate, tetramercaptobenzene, para-mercaptoterephthalic acid, hexamercaptotriphenylene, tris[2-(3-mercaptopropionyl)ethyl]isocyanuric acid, 2,3-dimercaptosuccinic acid, trimercapto-s-triazine and 6-pentaerythritol tetra(3-mercaptobutyrate).

[0019] In some embodiments of the present application, the anhydride curing agent is selected from at least one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, 2,2-dimethylglutaric anhydride, 2,3-dimethylsuccinic anhydride, glutaric anhydride, succinic anhydride, mellitic acid anhydride, 4,4'-biphenyl ether dianhydride, pyromellitic acid dianhydride, biphenyltetracarboxylic acid dianhydride and methyl nadic anhydride.

[0020] In some embodiments of the present application, the mass fractions of the components of the epoxy resin composition are as follows:

[0021] Epoxy resin: 100 parts;

[0022] First curing agent: 1-20 parts;

[0023] When the second curing agent is an amine with an active hydrogen number ≥3 or a thiol curing agent with an active hydrogen number ≥3, the mass fraction of the second curing agent is Cg[ab / 100-2e / f] / h, wherein a is the mass fraction of the epoxy resin (in g), b is the epoxy value of the epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), h is the number of active hydrogens contained in the second curing agent, g is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2;

[0024] When the second curing agent is an anhydride curing agent, the mass fraction of the second curing agent is Ck[ab / 100-2e / f] / j, wherein a is the mass fraction of the epoxy resin (in g), b is the epoxy value of the epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), j is the number of anhydride groups contained in the second curing agent, k is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2.

[0025] In some embodiments of the present application, the epoxy resin is a first epoxy resin and a second epoxy resin, the first epoxy resin is selected from one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin, and the second epoxy resin is selected from one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin.

[0026] In some embodiments of the present application, the epoxy values ​​of the first epoxy resin and the second epoxy resin are 0.2-0.9 mol / 100g, and the epoxy value of the first epoxy resin is smaller than the epoxy value of the second epoxy resin.

[0027] In some embodiments of the present application, the mass fractions of the components of the epoxy resin composition are as follows:

[0028] First epoxy resin: 70-100 parts;

[0029] Second epoxy resin: 1-30 parts;

[0030] First curing agent: 1-20 parts;

[0031] When the second curing agent is an amine with an active hydrogen number ≥3 or a thiol curing agent with an active hydrogen number ≥3, the mass fraction of the second curing agent is Cg[(ab+cd) / 100-2e / f] / h, wherein a is the mass fraction of the first epoxy resin (in g), b is the epoxy value of the first epoxy resin (in mol / 100g), c is the mass fraction of the second epoxy resin (in g), d is the epoxy value of the second epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), h is the number of active hydrogens contained in the second curing agent, g is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2;

[0032] When the second curing agent is an anhydride curing agent, the mass fraction of the second curing agent is Ck[(ab+cd) / 100-2e / f] / j, wherein a is the mass fraction of the first epoxy resin (in g), b is the epoxy value of the first epoxy resin (in mol / 100g), c is the mass fraction of the second epoxy resin (in g), d is the epoxy value of the second epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), j is the number of anhydride groups contained in the second curing agent, k is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2.

[0033] In some embodiments of the present application, the epoxy resin composition further comprises 1-350 parts of a filler, wherein the filler comprises at least one of aluminum oxide, silica powder, white carbon black, magnesium oxide, boron nitride, kaolin and zinc oxide.

[0034] In a second aspect of the present invention, a method for preparing the above-mentioned epoxy resin composition is provided, wherein the preparation method comprises the preparation of component A and the preparation of component B;

[0035] The preparation method of the component A comprises: mixing epoxy resin uniformly, and vacuum degassing under certain conditions to obtain the component A;

[0036] The preparation method of the B component comprises: mixing the first curing agent and the second curing agent uniformly, and vacuum dehydrating and degassing under certain conditions to obtain the B component;

[0037] The component A and the component B are mixed, injected into a mold, and cured under certain conditions to obtain the epoxy resin composition.

[0038] In some embodiments of the present application, if the epoxy resin is the first epoxy resin and the second epoxy resin, the preparation method of the component A includes: mixing the first epoxy resin and the second epoxy resin uniformly, and vacuum degassing under certain conditions to obtain the component A;

[0039] Alternatively, the preparation method of the component A comprises: uniformly mixing the first epoxy resin and the second epoxy resin, dehydrating and degassing the filler under certain conditions, and adding the pretreated filler to the resin mixture to obtain the component A;

[0040] Alternatively, the preparation method of the B component includes: uniformly mixing the first curing agent and the second curing agent, and dehydrating and degassing under certain conditions to obtain the B component.

[0041] In a third aspect, the present invention provides an epoxy resin composition for use in preparing insulating parts in electronic and electrical equipment.

[0042] The epoxy resin composition of the present invention includes component A and component B. Component A includes epoxy resin; component B includes a first curing agent and a second curing agent. The first curing agent is a curing agent containing two active hydrogens, and the second curing agent is selected from an amine curing agent with an active hydrogen number ≥3, a mercapto curing agent with an active hydrogen number ≥3, or an anhydride curing agent. The first curing agent and the second curing agent constitute a co-curing system, and the first curing agent has only two active hydrogens in its molecular structure, which only plays a chain extension role in the curing reaction, and the free volume of its region is larger than the curing region of the second curing agent. By selecting the first curing agent and the second curing agent of different main chain structure categories as the co-curing system, the electrical insulation performance and Tg of the epoxy resin composition can be improved while improving the heat resistance, crack resistance, voltage resistance and mechanical strength. DETAILED DESCRIPTION

[0043] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] Epoxy resin is a polymer containing two or more epoxy groups in its molecular structure. The epoxy groups it contains can react with curing agents (anhydrides, amines, etc.) to form a cross-linked cured product.

[0047] Cable accessories are an essential part of cable connection lines. With the development of high-voltage cross-linked cables in my country, the demand for supporting cable accessories is increasing. The operating environment of high-voltage cable accessories is very harsh. Whether it is the terminal bushing of the GIS system, the stress cone sleeve of the terminal, the transformer end bushing, or the intermediate joint shell, the materials used are required to have high mechanical and physical properties and electrical properties. Epoxy resin, as an electrical insulation material, has good electrical insulation properties, mechanical properties, bonding properties, and corrosion resistance. It also has the advantages of low dielectric loss, low curing shrinkage, low linear expansion coefficient, low water absorption, and good dimensional stability.

[0048] Epoxy resin compositions used for high-voltage power insulation must have good electrical insulation, voltage resistance, heat resistance, high and low temperature impact resistance, crack resistance, mechanical strength and chemical stability. However, it is difficult to take into account electrical insulation performance, voltage resistance, heat resistance, mechanical strength and crack resistance at the same time.

[0049] In a first aspect, the present invention provides an epoxy resin composition comprising a component A and a component B;

[0050] The component A includes epoxy resin; the component B includes a first curing agent and a second curing agent;

[0051] The first curing agent is a curing agent containing two active hydrogens;

[0052] The second curing agent is selected from an amine curing agent with an active hydrogen number of ≥3, a mercapto curing agent with an active hydrogen number of ≥3, or an acid anhydride curing agent.

[0053] It should be noted that active hydrogen is a hydrogen atom that can undergo a ring-opening reaction with an epoxy group under certain conditions.

[0054] The epoxy resin composition of the present invention includes component A and component B. Component A includes epoxy resin; component B includes a first curing agent and a second curing agent. The first curing agent is a curing agent containing two active hydrogens, and the second curing agent is selected from an amine curing agent with an active hydrogen number ≥3, a mercapto curing agent with an active hydrogen number ≥3, or an anhydride curing agent. The first curing agent and the second curing agent constitute a co-curing system, and the first curing agent has only two active hydrogens in its molecular structure, which only plays a chain extension role in the curing reaction, and the free volume of its region is larger than the curing region of the second curing agent. By selecting the first curing agent and the second curing agent of different main chain structure categories as the co-curing system, the electrical insulation performance and Tg of the epoxy resin composition can be improved while improving the heat resistance, crack resistance, voltage resistance and mechanical strength.

[0055] In some embodiments of the present application, the epoxy resin includes at least one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin.

[0056] In some embodiments of the present application, the first curing agent includes at least one of a bisphenol hydroxyl curing agent containing two active hydrogens, a dicarboxyl curing agent, a diimine curing agent, a dithiol curing agent, or a curing agent containing any two groups of phenolic hydroxyl, thiol, carboxyl and imine.

[0057] Specifically, the structural formula of the bisphenol hydroxyl curing agent is:

[0058]

[0059] Only one of R1-R5 is -OH, and the others are -H or organic groups without active hydrogen; or only one of R1-R5 contains phenolic hydroxyl group, and the others are -H or organic groups without active hydrogen.

[0060] The structural formula of dicarboxyl curing agent is:

[0061] HOOC-R6·COOH

[0062] R6: an organic group containing no active hydrogen.

[0063] The structural formula of diimide curing agent is:

[0064]

[0065] R7-R8: an organic group not containing active hydrogen; R8 and R9 cannot be -H.

[0066] The structural formula of the dithiol curing agent is:

[0067]

[0068] R 10 : An organic group that does not contain active hydrogen.

[0069] Specifically, the first curing agent is selected from at least one of bisphenol A, hydroquinone and 4.4'-biphenylene glycol, sebacic acid, terephthalic acid, 4.4'-bis-sec-butylaminodiphenylmethane, 4.4'-diacetamidodiphenylmethane, 2-dimercaptoethyl sulfide, and 2,2'-(1,2-ethylenedioxy)bisethylmercaptan.

[0070] In some embodiments of the present application, the amine curing agent having an active hydrogen number ≥ 3 includes at least one of a linear aliphatic amine, an alicyclic amine, and an aromatic amine.

[0071] Specifically, the amine curing agent having an active hydrogen number ≥ 3 is selected from at least one of 4,4'-diaminodiphenylmethane, triethylenetetramine, isophoronediamine, 4,4'-diaminodiphenyl sulfone, polyetheramine, polyesteramine, 4,4'-oxydiphenylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, m-phenylenediamine, o-phenylenediamine and p-phenylenediamine.

[0072] In some embodiments of the present application, the mercapto curing agent having an active hydrogen number ≥ 3 includes at least one of a linear aliphatic mercapto group, an alicyclic mercapto group, and an aromatic mercapto group.

[0073] Specifically, the mercapto curing agent having an active hydrogen number ≥ 3 is selected from at least one of trimethylolpropane tris(2-mercaptoacetate), pentaerythritol tetramercaptoacetate, tetramercaptobenzene, para-mercaptoterephthalic acid, hexamercaptotriphenylene, tris[2-(3-mercaptopropionyl)ethyl]isocyanuric acid, 2,3-dimercaptosuccinic acid, trimercapto-s-triazine and 6-pentaerythritol tetrakis(3-mercaptobutyrate).

[0074] In some embodiments of the present application, the anhydride curing agent includes at least one of an aromatic anhydride, an alicyclic anhydride or a linear aliphatic anhydride.

[0075] Specifically, the anhydride curing agent is selected from at least one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, 2,2-dimethylglutaric anhydride, 2,3-dimethylsuccinic anhydride, glutaric anhydride, succinic anhydride, mellitic acid anhydride, 4,4'-biphenyl ether dianhydride, pyromellitic acid dianhydride, biphenyltetracarboxylic acid dianhydride and methylnadic anhydride.

[0076] In some embodiments of the present application, the mass fractions of the components of the epoxy resin composition are as follows:

[0077] Epoxy resin: 100 parts;

[0078] First curing agent: 1-20 parts;

[0079] When the second curing agent is an amine with an active hydrogen number ≥3 or a thiol curing agent with an active hydrogen number ≥3, the mass fraction of the second curing agent is Cg[ab / 100-2e / f] / h, wherein a is the mass fraction of the epoxy resin (in g), b is the epoxy value of the epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), h is the number of active hydrogens contained in the second curing agent, g is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2;

[0080] When the second curing agent is an anhydride curing agent, the mass fraction of the second curing agent is Ck[ab / 100-2e / f] / j, wherein a is the mass fraction of the epoxy resin (in g), b is the epoxy value of the epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), j is the number of anhydride groups contained in the second curing agent, k is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2.

[0081] For example, the first curing agent is 1 part, 3 parts, 6 parts, 9 parts, 12 parts, 15 parts, 18 parts, or 20 parts.

[0082] In some embodiments, the epoxy resin is a first epoxy resin and a second epoxy resin, wherein the first epoxy resin is selected from one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin, and the second epoxy resin is selected from one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin.

[0083] In some embodiments, the epoxy value of the first epoxy resin and the second epoxy resin is 0.2-0.9 mol / 100g, and the epoxy value of the first epoxy resin is less than the epoxy value of the second epoxy resin.

[0084] In some embodiments, the mass fractions of the components of the epoxy resin composition are as follows:

[0085] First epoxy resin: 70-100 parts;

[0086] Second epoxy resin: 1-30 parts;

[0087] First curing agent: 1-20 parts;

[0088] When the second curing agent is an amine with an active hydrogen number ≥3 or a thiol curing agent with an active hydrogen number ≥3, the mass fraction of the second curing agent is Cg[(ab+cd) / 100-2e / f] / h, wherein a is the mass fraction of the first epoxy resin (in g), b is the epoxy value of the first epoxy resin (in mol / 100g), c is the mass fraction of the second epoxy resin (in g), d is the epoxy value of the second epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), h is the number of active hydrogens contained in the second curing agent, g is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2;

[0089] When the second curing agent is an anhydride curing agent, the mass fraction of the second curing agent is Ck[(ab+cd) / 100-2e / f] / j, wherein a is the mass fraction of the first epoxy resin (in g), b is the epoxy value of the first epoxy resin (in mol / 100g), c is the mass fraction of the second epoxy resin (in g), d is the epoxy value of the second epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), j is the number of anhydride groups contained in the second curing agent, k is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2.

[0090] For example, the first epoxy resin is 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts, and 100 parts; the second epoxy resin is 1 part, 3 parts, 6 parts, 9 parts, 12 parts, 15 parts, 18 parts, 21 parts, 24 parts, 27 parts, and 30 parts; and the first curing agent is 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, and 20 parts.

[0091] The epoxy resin adopts a first epoxy resin and a second epoxy resin, the epoxy values ​​of the first epoxy resin and the second epoxy resin are 0.2-0.9 mol / 100g, and the epoxy value of the first epoxy resin is less than the epoxy value of the second epoxy resin. At the same time, the mass fractions of the first epoxy resin and the second epoxy resin are matched, the first epoxy resin is 70-100 parts, and the second epoxy resin is 1-30 parts. Since the second epoxy resin is shorter than the first epoxy resin in average chain length, the crosslinking density of the second epoxy resin region after the curing reaction is greater than that of the first epoxy resin cured region. Therefore, through the curing of the two-component epoxy resin, a soft-encased hard interpenetrating crosslinking network structure can be obtained, and this network structure can further improve its heat resistance and Tg on the basis of the first epoxy resin.

[0092] In some embodiments, the epoxy resin composition further comprises 1-350 parts of a filler, and the filler comprises at least one of aluminum oxide, silica powder, white carbon black, magnesium oxide, boron nitride, kaolin and zinc oxide.

[0093] Adding appropriate fillers to the epoxy curing system can reduce costs, inhibit reaction heat, extend the useful life of the resin composition, reduce the shrinkage and thermal expansion coefficient of the cured product, improve the heat resistance and bending strength of the cured product, improve the arc resistance, tracking resistance and high-temperature dielectric properties of the cured product, etc. The filler in the present invention is a known filler in the application of epoxy electrical insulating materials, including at least one of aluminum oxide, silicon powder, white carbon black, magnesium oxide, boron nitride, kaolin and zinc oxide. The average particle diameter of the filler is preferably 1 to 100 microns, and more preferably 5 to 70 microns.

[0094] In a second aspect of the present invention, a method for preparing the above-mentioned epoxy resin composition is provided, the preparation method comprising the preparation of component A and the preparation of component B;

[0095] The preparation method of component A includes: mixing epoxy resin uniformly, and vacuum degassing under certain conditions to obtain component A;

[0096] The preparation method of component B comprises: mixing the first curing agent and the second curing agent uniformly, and vacuum dehydrating and degassing under certain conditions to obtain the component B;

[0097] Component A and component B are mixed, injected into a mold, and cured under certain conditions to obtain an epoxy resin composition.

[0098] In some embodiments, if the epoxy resin is a first epoxy resin and a second epoxy resin, the preparation method of component A includes: mixing the first epoxy resin and the second epoxy resin uniformly, and vacuum degassing under certain conditions to obtain component A;

[0099] Alternatively, the preparation method of component A includes: uniformly mixing a first epoxy resin and a second epoxy resin, dehydrating and degassing a filler under certain conditions, and adding the pretreated filler to the resin mixture to obtain component A;

[0100] Alternatively, the preparation method of the B component includes: uniformly mixing the first curing agent and the second curing agent, and dehydrating and degassing under certain conditions to obtain the B component.

[0101] Specifically, the preparation method of component A includes: drying and degassing the epoxy resin for more than 3 hours at 80° C. to 120° C. and a vacuum degree not higher than 3500 Pa to obtain component A;

[0102] The preparation method of component B comprises: mixing a first curing agent and a second curing agent uniformly, and degassing and dehydrating the mixture of the first curing agent and the second curing agent under a vacuum environment of 50° C. to 90° C. and a vacuum degree not higher than 5000 Pa to obtain component B;

[0103] Component A and component B are mixed, injected into a mold, and cured at 80° C. to 180° C. and a vacuum degree not higher than 5000 Pa to obtain an epoxy resin composition.

[0104] In a third aspect, the present invention provides an epoxy resin composition for use in preparing insulating parts in electronic and electrical equipment.

[0105] The present invention is further described in detail below with reference to specific embodiments.

[0106] The information of the raw materials involved in the specific implementation is shown in Table 1:

[0107] Table 1 Information on raw materials of epoxy resin compositions of Examples and Comparative Examples

[0108]

[0109]

[0110] Example 1

[0111] Please refer to Table 1 and Table 2. The epoxy resin composition of this embodiment includes the following raw materials in parts by weight:

[0112] Bisphenol A epoxy resin 2: 100 parts;

[0113] First curing agent bisphenol A: 1 part;

[0114] Second curing agent 4,4'-diaminodiphenylmethane: 24 parts;

[0115] Filler: 300 parts.

[0116] The preparation method of the epoxy resin composition is:

[0117] The preparation method of component A comprises: drying and degassing bisphenol A epoxy resin 2 for more than 3 hours at 80° C. to 120° C. and a vacuum degree not higher than 3500 Pa to obtain component A;

[0118] The preparation method of component B comprises: uniformly mixing a first curing agent bisphenol A and a second curing agent 4,4'-diaminodiphenylmethane, and degassing and dehydrating the mixture of the first curing agent and the second curing agent under a vacuum environment of 50° C. to 90° C. and a vacuum degree not higher than 5000 Pa to obtain component B;

[0119] Component A and component B are mixed, injected into a mold, and cured at 100° C. to 180° C. and a vacuum degree not higher than 5000 Pa to obtain an epoxy resin composition.

[0120] Example 2

[0121] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except for the number of components, as shown in Table 1 and Table 2:

[0122] Bisphenol A epoxy resin 2: 100 parts;

[0123] First curing agent bisphenol A: 10 parts;

[0124] Second curing agent 4,4'-diaminodiphenylmethane: 16 parts;

[0125] Filler: 300 parts.

[0126] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the parts of each raw material component are different, please refer to Table 2.

[0127] Example 3

[0128] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except for the number of components, as shown in Table 2:

[0129] Bisphenol A epoxy resin 2: 100 parts;

[0130] First curing agent bisphenol A: 20 parts;

[0131] Second curing agent 4,4'-diaminodiphenylmethane: 7 parts;

[0132] Filler: 300 parts.

[0133] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the parts of each raw material component are different, please refer to Table 2.

[0134] Example 4

[0135] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the composition and quantity of each component are shown in Table 1 and Table 2:

[0136] Bisphenol A epoxy resin 1: 100 parts;

[0137] The first curing agent is terephthalic acid: 10 parts;

[0138] Second curing agent 4,4'-diaminodiphenylmethane: 6 parts;

[0139] Filler: 300 parts.

[0140] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0141] Example 5

[0142] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the composition and quantity of each component are shown in Table 1 and Table 2:

[0143] Bisphenol A epoxy resin 1: 100 parts;

[0144] The first curing agent 4.4'-bis-sec-butylaminodiphenylmethane: 10 parts;

[0145] Second curing agent 4,4'-diaminodiphenylmethane: 9 parts;

[0146] Filler: 300 parts.

[0147] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0148] Example 6

[0149] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the composition and quantity of each component are shown in Table 1 and Table 2:

[0150] Bisphenol A epoxy resin 1: 100 parts;

[0151] First curing agent bisphenol A: 10 parts;

[0152] Second curing agent trimethylolpropane tris(2-thioglycolate): 8 parts;

[0153] Filler: 300 parts.

[0154] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0155] Example 7

[0156] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the composition and quantity of each component are shown in Table 1 and Table 2:

[0157] Bisphenol A epoxy resin 1: 100 parts;

[0158] First curing agent bisphenol A: 10 parts;

[0159] Second curing agent: 9.5 parts of methyltetrahydrophthalic anhydride;

[0160] Filler: 300 parts.

[0161] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0162] Example 8

[0163] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the composition and quantity of each component are shown in Table 1 and Table 2:

[0164] Bisphenol A epoxy resin 1: 100 parts;

[0165] First curing agent bisphenol A: 10 parts;

[0166] Second curing agent methyltetrahydrophthalic anhydride: 13 parts;

[0167] Filler: 300 parts.

[0168] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0169] Example 9

[0170] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 1, except that the composition and quantity of each component are shown in Table 1 and Table 2:

[0171] Bisphenol A epoxy resin 1: 70 parts;

[0172] Bisphenol A epoxy resin 3: 30 parts;

[0173] First curing agent bisphenol A: 10 parts;

[0174] Second curing agent methyltetrahydrophthalic anhydride: 21 parts;

[0175] Filler: 300 parts.

[0176] The preparation method of the epoxy resin composition is:

[0177] The preparation method of component A comprises: drying and degassing bisphenol A epoxy resin 1 and bisphenol A epoxy resin 3 for more than 3 hours at 80° C. to 120° C. and a vacuum degree not higher than 3500 Pa to obtain component A;

[0178] The preparation method of component B comprises: uniformly mixing a first curing agent, bisphenol A, and a second curing agent, methyltetrahydrophthalic anhydride; and degassing and dehydrating the mixture of the first curing agent and the second curing agent under a vacuum environment of 50° C. to 90° C. and a vacuum degree not higher than 5000 Pa to obtain component B;

[0179] Component A and component B are mixed, injected into a mold, and cured at 100° C. to 180° C. and a vacuum degree not higher than 5000 Pa to obtain an epoxy resin composition.

[0180] Example 10

[0181] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 9, except for the composition and quantity of each component, as shown in Table 1 and Table 2:

[0182] Bisphenol A epoxy resin 1: 90 parts;

[0183] Alicyclic epoxy resin: 10 parts;

[0184] First curing agent bisphenol A: 10 parts;

[0185] Second curing agent methyltetrahydrophthalic anhydride: 19 parts;

[0186] Filler: 300 parts.

[0187] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 9, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0188] Embodiment 11

[0189] The raw material formula for preparing the epoxy resin composition of this embodiment is basically the same as that of Example 9, except for the composition and quantity of each component, as shown in Table 1 and Table 2:

[0190] Bisphenol A epoxy resin 1: 85 parts;

[0191] Bisphenol A epoxy resin 3: 15 parts;

[0192] First curing agent bisphenol A: 10 parts;

[0193] Second curing agent methyltetrahydrophthalic anhydride: 16 parts;

[0194] Filler: 300 parts.

[0195] The preparation method of the epoxy resin composition of this embodiment is basically the same as that of Example 9, except that the ingredients and proportions of each raw material component are different, see Table 2.

[0196] Comparative Example 1

[0197] The raw material formula for preparing the epoxy resin composition of this comparative example is basically the same as that of Example 1, except for the number of components, as shown in Table 1 and Table 2:

[0198] Bisphenol A epoxy resin 2: 100 parts;

[0199] First curing agent bisphenol A: 26 parts;

[0200] Filler: 300 parts.

[0201] The preparation method of the epoxy resin composition of this comparative example is basically the same as that of Example 1, except that the parts of each raw material component are different, please refer to Table 2.

[0202] Comparative Example 2

[0203] The raw material formula for preparing the epoxy resin composition of this comparative example is basically the same as that of Example 1, except for the number of components, as shown in Table 1 and Table 2:

[0204] Bisphenol A epoxy resin 2: 100 parts;

[0205] Second curing agent 4,4'-diaminodiphenylmethane: 26 parts;

[0206] Filler: 300 parts.

[0207] The preparation method of the epoxy resin composition of this comparative example is basically the same as that of Example 1, except that the parts of each raw material component are different, please refer to Table 2.

[0208] Comparative Example 3

[0209] The raw material formula for preparing the epoxy resin composition of this comparative example is basically the same as that of Example 9, except for the number of components, as shown in Table 1 and Table 2:

[0210] Bisphenol A epoxy resin 1: 60 parts;

[0211] Bisphenol A epoxy resin 2: 40 parts;

[0212] First curing agent bisphenol A: 10 parts;

[0213] Second curing agent: 4,4'-diaminodiphenylmethane: 9 parts;

[0214] Filler: 300 parts.

[0215] The preparation method of the epoxy resin composition of this comparative example is basically the same as that of Example 9, except that the parts of each raw material component are different, please refer to Table 2.

[0216] The test standards for the performance of the epoxy resin compositions obtained in the above examples and comparative examples are as follows:

[0217] (1) Breakdown strength test

[0218] According to the method specified in GB / T 1408-2016, the test was carried out using a power frequency test transformer (power frequency voltage measurement system). The test temperature was 23±2℃. The electrical performance test used samples with a diameter of 100mm and a thickness of 1mm. To prevent surface flashover, 5 samples were tested. The samples and electrodes were immersed in dimethyl silicone oil. During the test, the voltage rise rate was controlled to 1kV / s, and the results were averaged.

[0219] (2) Dielectric properties test

[0220] The test was carried out according to the method specified in 7.3 of GB 1409-2006. The test temperature was 23±2℃. The relative dielectric constant and dielectric loss of the sample at room temperature were tested using a broadband dielectric spectrometer. The test frequency range was 10 -1 ~10 6 Hz. Test 5 samples and take the average value of the results.

[0221] (3) Tensile test

[0222] The test was conducted in accordance with Article 9 of GB 1040-2008, the test temperature was 23±2℃, and the tensile test used a standard dumbbell-shaped specimen with a tensile speed of 2mm / min. The tensile strength and elongation at break of 5 specimens were tested using a micro-controlled electronic universal material tensile machine of Dongguan High-speed Railway Testing Co., Ltd., and the results were averaged.

[0223] (4) Glass transition temperature test

[0224] Differential scanning calorimetry (DSC) was performed using a differential scanning calorimeter from NETZSCH, Germany. The sample mass was about 5-10 mg, the test temperature range was 30-180°C, the heating rate was 10K / min, and the test atmosphere was nitrogen with a flow rate of 20 mL / min.

[0225] (5) Thermal stability test

[0226] Thermogravimetric analysis (TGA) was performed using a German NETZSCH thermogravimetric analyzer. A sample of about 5-10 mg was taken and the test was performed in a nitrogen atmosphere with an atmosphere flow rate of 20 mL / min, a temperature test range of 50-700°C, and a heating rate of 10 K / min.

[0227] (6) Impact performance test

[0228] The impact strength was measured using an automated digital IZOD impact tester (Guangdong, Guangce) according to GB / T 1843-2008.

[0229] See Table 3 for test results of the epoxy resin composition GJB7279-2011 prepared in the examples and comparative examples.

[0230] Table 2 Epoxy resin composition examples and comparative examples

[0231]

[0232]

[0233]

[0234] Table 3 Test results of epoxy resin composition GJB7279-2011 prepared in Examples and Comparative Examples

[0235]

[0236]

[0237] As shown in Table 3, the glass transition temperatures Tg of the epoxy resin compositions prepared in Examples 1 to 11 are all greater than 120°C, indicating that the temperature range of their use is relatively wide. The thermal stability is good, and the mass loss temperature of 5% of thermal decomposition under specific conditions is Tg. d5％ All are greater than 350°C, Tmax is greater than 380°C, and at 700 degrees Celsius, the amount of residual carbon after pyrolysis of the material accounts for a percentage of the original material weight RCY700°C (wt%) is greater than 70%. The dielectric properties, such as dielectric constant and dielectric loss, are good. The breakdown strength of Examples 1 to 6 is greater than 12KV / mm, and the breakdown strength of Examples 7 to 11 is greater than 30KV / mm. Both the tensile strength and the elongation at break can be improved, and the impact strength of Examples 1 to 3 is greater than 6KJ / m 2 The impact strength of Examples 4 to 11 is greater than 10KJ / m 2 Good crack resistance.

[0238] In Comparative Example 1, no second curing agent was added, and the prepared epoxy resin composition had a long-chain structure. Compared with the 3D network cross-linked structure of the epoxy resin composition in Example 2, the glass transition temperature Tg, dielectric properties, breakdown strength, tensile strength, elongation at break, and impact strength were significantly reduced.

[0239] No first curing agent was added to Comparative Example 2. Although the prepared epoxy resin composition also had a network structure, Comparative Example 2 lacked a first curing agent that was more rigid than the epoxy resin main chain structure. Therefore, compared with Example 2, the epoxy resin composition prepared in Comparative Example 2 had a downward trend in glass transition temperature Tg, dielectric properties, breakdown strength, tensile strength, elongation at break, and impact strength.

[0240] Although Comparative Example 3 uses two curing agents, the mass fraction of the first epoxy resin is too small and the mass fraction of the second epoxy resin is too large, which makes it difficult for the two resins to mix evenly during the mixing process, and defects are easily generated inside the interpenetrating network structure after curing. As a result, the epoxy resin composition prepared in Comparative Example 3 shows a downward trend in glass transition temperature Tg, dielectric properties, breakdown strength, tensile strength, elongation at break, and impact strength compared with Example 2.

[0241] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An epoxy resin composition, characterized in that It includes component A and component B; The A component includes epoxy resin; The B component includes a first curing agent and a second curing agent; The first curing agent is a curing agent containing two active hydrogens; The second curing agent is selected from an amine curing agent with an active hydrogen number of ≥3, a mercapto curing agent with an active hydrogen number of ≥3, or an acid anhydride curing agent.

2. The epoxy resin composition according to claim 1, characterized in that The epoxy resin includes at least one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin and aliphatic epoxy resin.

3. The epoxy resin composition according to claim 1, characterized in that The first curing agent includes at least one of a bisphenol hydroxyl curing agent, a dicarboxyl curing agent, a diimine curing agent, a dithiol curing agent or a curing agent containing any two groups of phenolic hydroxyl, thiol, carboxyl and imine.

4. The epoxy resin composition according to claim 3, characterized in that The first curing agent is selected from at least one of bisphenol A, hydroquinone and 4.4'-biphenylene glycol, sebacic acid, terephthalic acid, 4.4'-bis-sec-butylaminodiphenylmethane, 4.4'-diacetamidodiphenylmethane, 2-dimercaptoethyl sulfide, and 2,2'-(1,2-ethylenedioxy)bisethylmercaptan.

5. The epoxy resin composition according to claim 1, characterized in that The amine curing agent with the number of active hydrogen atoms ≥3 includes at least one of linear aliphatic amines, alicyclic amines and aromatic amines.

6. The epoxy resin composition according to claim 1, characterized in that The mercapto curing agent with the number of active hydrogen atoms ≥3 includes at least one of a straight-chain aliphatic mercapto group, an alicyclic mercapto group, and an aromatic mercapto group.

7. The epoxy resin composition according to claim 1, characterized in that The acid anhydride curing agent includes at least one of aromatic acid anhydride, alicyclic acid anhydride or linear aliphatic acid anhydride.

8. The epoxy resin composition according to claim 5, characterized in that The amine curing agent having an active hydrogen number of ≥3 is selected from at least one of 4,4'-diaminodiphenylmethane, triethylenetetramine, isophoronediamine, 4,4'-diaminodiphenylsulfone, polyetheramine, polyesteramine, 4,4'-oxydiphenylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, m-phenylenediamine, o-phenylenediamine and p-phenylenediamine.

9. The epoxy resin composition according to claim 6, characterized in that The mercapto curing agent having an active hydrogen number of ≥3 is selected from at least one of trimethylolpropane tris(2-mercaptoacetate), pentaerythritol tetramercaptoacetate, tetramercaptobenzene, para-mercaptoterephthalic acid, hexamercaptotriphenylene, tris[2-(3-mercaptopropionyl)ethyl]isocyanuric acid, 2,3-dimercaptosuccinic acid, trimercapto-s-triazine and 6-pentaerythritol tetra(3-mercaptobutyrate).

10. The epoxy resin composition according to claim 7, characterized in that The acid anhydride curing agent is selected from at least one of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, 2,2-dimethylglutaric anhydride, 2,3-dimethylsuccinic anhydride, glutaric anhydride, succinic anhydride, mellitic acid trianhydride, 4,4'-biphenyl ether dianhydride, pyromellitic acid dianhydride, biphenyltetracarboxylic acid dianhydride and methylnadic anhydride.

11. The epoxy resin composition according to claim 1, characterized in that The mass fractions of each component of the epoxy resin composition are as follows: Epoxy resin: 100 parts; First curing agent: 1-20 parts; When the second curing agent is an amine with an active hydrogen number ≥3 or a thiol curing agent with an active hydrogen number ≥3, the mass fraction of the second curing agent is Cg[ab / 100-2e / f] / h, wherein a is the mass fraction of the epoxy resin (in g), b is the epoxy value of the epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), h is the number of active hydrogens contained in the second curing agent, g is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2; When the second curing agent is an anhydride curing agent, the mass fraction of the second curing agent is Ck[ab / 100-2e / f] / j, wherein a is the mass fraction of the epoxy resin (in g), b is the epoxy value of the epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), j is the number of anhydride groups contained in the second curing agent, k is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.

2.

12. The epoxy resin composition according to claim 1, characterized in that The epoxy resin is a first epoxy resin and a second epoxy resin, the first epoxy resin is selected from one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin, and the second epoxy resin is selected from one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and aliphatic epoxy resin.

13. The epoxy resin composition according to claim 12, characterized in that The epoxy values ​​of the first epoxy resin and the second epoxy resin are 0.2-0.9 mol / 100g, and the epoxy value of the first epoxy resin is smaller than the epoxy value of the second epoxy resin.

14. The epoxy resin composition according to claim 13, characterized in that The mass fractions of each component of the epoxy resin composition are as follows: First epoxy resin: 70-100 parts; Second epoxy resin: 1-30 parts; First curing agent: 1-20 parts; When the second curing agent is an amine with an active hydrogen number ≥3 or a thiol curing agent with an active hydrogen number ≥3, the mass fraction of the second curing agent is Cg[(ab+cd) / 100-2e / f] / h, wherein a is the mass fraction of the first epoxy resin (in g), b is the epoxy value of the first epoxy resin (in mol / 100g), c is the mass fraction of the second epoxy resin (in g), d is the epoxy value of the second epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), h is the number of active hydrogens contained in the second curing agent, g is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.2; When the second curing agent is an anhydride curing agent, the mass fraction of the second curing agent is Ck[(ab+cd) / 100-2e / f] / j, wherein a is the mass fraction of the first epoxy resin (in g), b is the epoxy value of the first epoxy resin (in mol / 100g), c is the mass fraction of the second epoxy resin (in g), d is the epoxy value of the second epoxy resin (in mol / 100g), e is the mass fraction of the first curing agent (in g), f is the molar mass of the first curing agent (g / mol), j is the number of anhydride groups contained in the second curing agent, k is the molar mass of the second curing agent (g / mol), and C is the correction coefficient, 0.8≤C≤1.

2.

15. The epoxy resin composition according to claim 1, characterized in that The epoxy resin composition further comprises 1-350 parts of a filler, wherein the filler comprises at least one of aluminum oxide, silicon powder, white carbon black, magnesium oxide, boron nitride, kaolin and zinc oxide.

16. A method for preparing the epoxy resin composition according to any one of claims 1 to 15, characterized in that: The preparation method includes the preparation of component A and the preparation of component B; The preparation method of the component A comprises: mixing epoxy resin uniformly, and vacuum degassing under certain conditions to obtain the component A; The preparation method of the B component comprises: mixing the first curing agent and the second curing agent uniformly, and vacuum dehydrating and degassing under certain conditions to obtain the B component; The component A and the component B are mixed, injected into a mold, and cured under certain conditions to obtain the epoxy resin composition.

17. The method for preparing the epoxy resin composition according to claim 16, characterized in that: If the epoxy resin is the first epoxy resin and the second epoxy resin, the preparation method of the component A includes: mixing the first epoxy resin and the second epoxy resin uniformly, and vacuum degassing under certain conditions to obtain the component A; Alternatively, the preparation method of the component A comprises: uniformly mixing the first epoxy resin and the second epoxy resin, dehydrating and degassing the filler under certain conditions, and adding the pretreated filler to the resin mixture to obtain the component A; Alternatively, the preparation method of the B component includes: uniformly mixing the first curing agent and the second curing agent, and dehydrating and degassing under certain conditions to obtain the B component.

18. Use of the epoxy resin composition according to any one of claims 1 to 15 in the preparation of insulating parts in electronic and electrical equipment.

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