A water-based epoxy insulating paint and its production process

Abstract

The present invention provides a water-based epoxy insulating varnish and a production process thereof, which belongs to the technical field of insulating varnish, and comprises the following steps: uniformly mixing a mixed solution of tung oil anhydride adduct, n-butanol and propylene glycol methyl ether, adding polyethylene glycol to react, cooling, adding triethylamine and dissolved epoxy resin to continue reacting, cooling and stirring, and obtaining epoxy resin modified tung oil water-based resin; adding metal organic framework, dopamine, and ground Ti3C2 nanosheets to Tris-HCl buffer solution, sealing and stirring, centrifuging and discarding supernatant, drying, and obtaining DA-MOF / Ti3C2; mixing DA-MOF / Ti3C2, epoxy resin modified tung oil water-based resin, and deionized water, adding L-tyrosine and mixing, and obtaining water-based epoxy insulating varnish. The present invention can achieve insulation performance, good thermal stability, and corrosion resistance at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of insulating varnishes, and in particular to a water-based epoxy insulating varnish and a production process thereof. Background Art

[0002] my country's power tool industry has developed rapidly, with production ranking first in the world and product quality constantly improving. The progress of the power tool industry will inevitably require the development of related insulating materials to meet the needs of the development of the power tool industry. Traditional organic solvent-based insulating varnishes contain a large amount of volatile organic compounds (VOCs), which not only cause serious environmental pollution but also pose a certain degree of threat to human health. In order to reduce the VOC content, researchers are committed to developing environmentally friendly water-based insulating varnishes. The solvent used is mainly water, which is non-toxic, harmless, low-cost, and has common raw materials. In addition, the VOC content is greatly reduced. This water-based insulating varnish reduces the harm to the environment and human body, but the poor barrier properties of water-based insulating varnishes lead to poor corrosion resistance, poor thermal stability, and poor insulation.

[0003] Plant oils can be used as resins or important components in organic paints because they have unique advantages, such as easy availability, environmental friendliness, inherent biodegradability, low cost, and easy modification. Among them, tung oil is an excellent drying plant oil with high use value and is often used as an important industrial raw material. However, tung oil is an oily substance and is difficult to disperse in water-based paints, which makes the current technical utilization level of tung oil in my country low and its use is severely limited.

[0004] Published in the 2011 issue 27 of Polymer Materials Science and Engineering, titled Preparation and Properties of Tung Oil Modified Alkyd Amino Waterborne Insulating Paint, tung oil was used to modify alkyd resin, and then amino resin was used as a crosslinking agent to obtain tung oil modified alkyd amino waterborne insulating paint. Although the insulating performance has been improved, it has poor water solubility due to excessive oil content and cannot be well dispersed in water. Developing a new generation of environmentally friendly water-based insulating paint products with good insulation and anti-corrosion properties and relatively low prices is an important issue facing the current insulating paint field.

[0005] Therefore, it is necessary to provide a water-based epoxy insulating varnish and a production process thereof to solve the problems existing in the above-mentioned prior art. Summary of the invention

[0006] In view of this, the present invention provides a water-based epoxy insulating varnish and a production process thereof, which can achieve insulation performance, good thermal stability and corrosion resistance at the same time.

[0007] To achieve the above object, the present invention provides a production process of a water-based epoxy insulating varnish, comprising the following steps:

[0008] S1, uniformly mixing a mixed solution of tung oil anhydride adduct, n-butanol and propylene glycol methyl ether, adding polyethylene glycol for reaction, cooling, adding triethylamine and dissolved epoxy resin for further reaction, cooling and stirring to obtain epoxy resin modified tung oil waterborne resin; the tung oil anhydride adduct is obtained by uniformly mixing tung oil and maleic anhydride and reacting;

[0009] S2, adding the metal organic framework, dopamine, and ground Ti3C2 nanosheets into a Tris-HCl buffer solution, sealing and stirring, centrifuging, discarding the supernatant, and drying to obtain DA-MOF / Ti3C2;

[0010] S3, after mixing DA-MOF / Ti3C2, epoxy resin modified tung oil water-based resin, and deionized water, L-tyrosine was added and mixed to prepare a water-based epoxy insulating paint

[0011] The present invention utilizes the esterification reaction of polyethylene glycol and tung oil anhydride adduct to connect the hydroxyl group of polyethylene glycol to the molecular chain of tung oil anhydride, so as to facilitate the subsequent connection of epoxy resin to the main chain of tung oil anhydride molecules through the action of ring-opening esterification, thereby increasing the crosslinking degree of the resin to form a tightly structured epoxy resin-modified tung oil waterborne resin. Epoxy resin, because of the presence of hydroxyl groups, ether bonds and active epoxy groups in its molecular structure, can form a crosslinked three-dimensional network structure under the action of a curing agent, providing good high adhesion and certain thermal stability for the whole; the conjugated triene structure of tung oil makes it have good electrical insulation, and has the advantages of fast drying and corrosion resistance; the combination of epoxy resin and tung oil solves the disadvantage that tung oil is difficult to disperse in water while having good insulation.

[0012] The present invention prepares DA-MOF / Ti3C2, wherein ground Ti3C2 nanosheets are added, and the two-dimensional layered structure of the Ti3C2 nanosheets serves as a physical barrier to impart insulation properties, and the fluorine groups on the surface of the Ti3C2 nanosheets have low surface energy and high hydrophobicity, so that water molecules and corrosive media are not easy to adhere to the surface of the material, thereby imparting a certain degree of corrosion resistance to the whole. The MOF material has low electrical conductivity, but is easy to agglomerate in the overall system, and a metal organic framework (MOF) is modified by dopamine (DA). The adhesion of dopamine can promote the stable dispersion of MOF in waterborne epoxy insulating paint and is more conducive to the dispersion of Ti3C2 nanosheets on the surface of MOF, thereby increasing the compatibility of MOF and Ti3C2 nanosheets, and generating polymer chains of dopamine through self-polymerization reaction. The surface hydrophobicity and compactness of the polymer chain structure help to reduce the penetration of water and electrolytes, thereby improving the insulation properties.

[0013] The present invention utilizes L-tyrosine as a curing agent. L-tyrosine is an aromatic amino acid and can be used as a bio-based curing agent for epoxy resin-modified tung oil water-based insulating paint. L-tyrosine contains three active hydrogen atoms and can react with epoxy groups in epoxy resin to form a cross-linked network structure, thereby achieving curing while complying with environmental protection concepts.

[0014] Optionally, the tung oil anhydride adduct in step S1 is obtained by uniformly mixing tung oil and maleic anhydride and reacting them at 120-125° C. for 1.5-2 hours; the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether in step S1 is 2:3.

[0015] The present invention utilizes tung oil and maleic anhydride to produce a Diels-Alder reaction to synthesize a tung oil anhydride addition product, and the reaction process is as follows:

[0016]

[0017] Optionally, in step S1, after the polyethylene glycol is added to react at a temperature of 110-125° C. for 2-3 hours, the temperature is then lowered to 95° C., triethylamine is added dropwise, and the dissolved epoxy resin is continued to react for 2-3 hours, the temperature is then lowered to 65° C. and stirred for 30-50 minutes to obtain an epoxy resin-modified tung oil water-based resin; the dissolved epoxy resin is obtained by dissolving the epoxy resin in a mixed solution of n-butanol and propylene glycol methyl ether and stirring at 65° C. for 30 minutes.

[0018] In the process of adding polyethylene glycol to the reaction, the hydroxyl group of the polyethylene glycol can undergo an esterification reaction with tung oil anhydride to provide hydroxyl groups therefor, thereby improving the overall water solubility; under the action of triethylamine as a promoter, the epoxy resin is connected to the tung oil anhydride molecular chain through the action of ring-opening esterification to synthesize the epoxy resin modified tung oil water-based resin, and the reaction process is as follows:

[0019]

[0020] Optionally, the preparation process of the epoxy resin modified tung oil water-based resin in step S1 is carried out under nitrogen protection, the nitrogen protection is terminated after cooling and stirring, and ammonia water is used to neutralize the pH to 7.0-7.2.

[0021] Optionally, in step S2, the ground Ti3C2 nanosheets are obtained by placing the Ti3C2 nanosheets in a ball mill and milling them at a speed of 500 r / min for 40 to 60 minutes; and the metal organic framework is NH2-MIL-101.

[0022] The present invention utilizes a ball mill to grind Ti3C2 nanosheets to obtain smaller and better size distribution, which is more conducive to dispersion on the surface of a metal organic framework; NH2-MIL-101 is utilized as a metal organic framework, wherein the surface amino functional groups therein can interact with moisture, gas, corrosive substances, etc., and capture them on the surface of the material, thereby reducing the penetration of these substances and further improving the corrosion resistance.

[0023] Optionally, in step S2, the sealing and stirring time is 12 to 16 hours, and the drying time is 12 to 24 hours.

[0024] Optionally, in step S3, when L-tyrosine is added and mixed, a dicyandiamide curing low-temperature accelerator is also added and mixed.

[0025] The dicyandiamide curing low-temperature accelerator used in the present invention is a potential accelerator based on urea, which is added to a mixture of epoxy resin and L-tyrosine to promote the curing reaction between the epoxy resin and L-tyrosine by reducing the reaction activation energy, thereby accelerating the curing process.

[0026] Optionally, the mixing and stirring time in step S3 is 30 to 60 minutes.

[0027] Optionally, the water-based epoxy insulating varnish comprises the following raw materials in parts by mass: 1 to 2.5 parts of DA-MOF / Ti3C2, 50 to 70 parts of epoxy resin-modified tung oil water-based resin, 50 to 80 parts of deionized water, and 5 to 10 parts of L-tyrosine; and also includes 1 to 2.5 parts of dicyandiamide curing low-temperature accelerator.

[0028] Optionally, the raw materials of the epoxy resin modified tung oil water-based resin include 10 to 14 parts of tung oil anhydride adduct calculated by weight, 1.4 to 2 parts of a mixed solution of n-butanol and propylene glycol methyl ether, 2 to 5 parts of polyethylene glycol, 0.5 to 1 part of triethylamine, and 25 to 30 parts of dissolved epoxy resin; the raw materials of the DA-MOF / Ti3C2 include 6 to 10 parts of NH2-MIL-101 calculated by weight, 0.6 to 1.5 parts of dopamine, 1 to 5 parts of ground Ti3C2 nanosheets, and 20 to 30 parts of Tris-HCl buffer solution; wherein the raw materials of the tung oil anhydride adduct include 40 to 50 parts of tung oil and 10 to 12 parts of maleic anhydride calculated by weight.

[0029] The above technical solution of the present invention includes at least the following beneficial effects:

[0030] The present invention connects epoxy resin to the main chain of tung oil anhydride molecules through the action of ring-opening esterification, improves the cross-linking degree of the resin, and forms a tightly structured epoxy resin-modified tung oil water-based resin. Since the epoxy resin contains hydroxyl groups, ether bonds and active epoxy groups in its molecular structure, it can form a cross-linked three-dimensional network structure under the action of a curing agent, providing good high adhesion and certain thermal stability for the whole; the conjugated triene structure of tung oil makes it have good electrical insulation, and has the advantages of fast drying and corrosion resistance; the combination of epoxy resin and tung oil solves the disadvantage that tung oil is difficult to disperse in water and has good insulation.

[0031] The present invention prepares DA-MOF / Ti3C2, wherein the layered structure of Ti3C2 nanosheets serves as a physical barrier to impart insulation performance, and the fluorine groups on the surface of the Ti3C2 nanosheets have low surface energy and high hydrophobicity to impart a certain corrosion resistance to the whole. The MOF material has low electrical conductivity, and MOF is modified by dopamine to promote the stable dispersion of MOF in waterborne epoxy insulating varnish and increase the compatibility of MOF and Ti3C2 nanosheets, and the polymer chains of dopamine generated by self-polymerization reaction are helpful to reduce the penetration of water and electrolytes, thereby improving the insulation performance.

[0032] The present invention uses L-tyrosine as a bio-based curing agent. L-tyrosine contains three active hydrogen atoms and can react with epoxy groups in epoxy resin to form a cross-linked network structure, thereby achieving curing while complying with environmental protection concepts. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The electrical strength variation diagram of the paint films obtained in Example 1 of the present invention and Comparative Examples 1 to 4 is shown. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in combination with the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0035] Example 1

[0036] Under the protection of nitrogen, 45 parts of tung oil and 10 parts of maleic anhydride were mixed evenly, and reacted at 125°C for 1.5 hours to obtain tung oil anhydride adduct; 12 parts of tung oil anhydride adduct, 1.5 parts of n-butanol and propylene glycol methyl ether were mixed evenly, 3 parts of polyethylene glycol were added, reacted at 110°C for 2.5 hours, cooled to 95°C, 0.7 parts of triethylamine were added, and 26 parts of dissolved epoxy resin were added dropwise, and the reaction was continued for 2.5 hours. , cool to 65°C and stir for 45 minutes, cool to room temperature to end nitrogen protection, neutralize with ammonia water to pH 7.0, and obtain epoxy resin modified tung oil water-based resin; wherein, 20 parts of epoxy resin are preliminarily dissolved in a mixed solution of 80 parts of n-butanol and propylene glycol methyl ether and stirred at 65°C for 30 minutes to obtain dissolved epoxy resin, and the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether is 2:3.

[0037] After 10 parts of Ti3C2 nanosheets were placed in a ball mill and ball-milled at a speed of 500r / min for 50 minutes, 7 parts of NH2-MIL-101 (CAS No.: 1414869-95-6), 0.9 parts of dopamine, and 3 parts of ground Ti3C2 nanosheets were added to 25 parts of Tris-HCl buffer solution. After sealed and stirred at room temperature for 14 hours, the supernatant was discarded by centrifugation and dried for 18 hours to obtain DA-MOF / Ti3C2.

[0038] After 2 parts of DA-MOF / Ti3C2, 60 parts of epoxy resin modified tung oil water-based resin, and 70 parts of deionized water were mixed and stirred for 50 minutes, 6 parts of L-tyrosine and 2 parts of dicyandiamide curing low-temperature accelerator (UR400) were added and mixed and stirred for 50 minutes to prepare a water-based epoxy insulating paint.

[0039] Example 2

[0040] Under the protection of nitrogen, 40 parts of tung oil and 10 parts of maleic anhydride were mixed evenly, and reacted at 125°C for 1.5 hours to obtain tung oil anhydride adduct; 10 parts of tung oil anhydride adduct, 1.4 parts of n-butanol and propylene glycol methyl ether were mixed evenly, 2 parts of polyethylene glycol were added, reacted at 118°C for 2-3 hours, then cooled to 95°C, 0.5 parts of triethylamine were added, and 25 parts of dissolved epoxy resin were added dropwise, and the reaction was continued for 2 hours. The temperature was lowered to 65°C and stirred for 30 minutes, and then the nitrogen protection was terminated after cooling to room temperature. After neutralization to pH 7.2 with ammonia water, epoxy resin-modified tung oil water-based resin was obtained; wherein, 20 parts of epoxy resin were preliminarily dissolved in a mixed solution of 80 parts of n-butanol and propylene glycol methyl ether and stirred at 65°C for 30 minutes to obtain dissolved epoxy resin, and the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether was 2:3.

[0041] After 10 parts of Ti3C2 nanosheets were placed in a ball mill and ball-milled at a speed of 500r / min for 40 minutes, 6 parts of NH2-MIL-101 (CAS No.: 1414869-95-6), 0.6 parts of dopamine, and 1 part of the ground Ti3C2 nanosheets were added to 20 parts of Tris-HCl buffer solution. After sealing and stirring at room temperature for 12 hours, the supernatant was discarded by centrifugation and dried for 12 hours to obtain DA-MOF / Ti3C2.

[0042] After 1 part of DA-MOF / Ti3C2, 50 parts of epoxy resin modified tung oil water-based resin, and 50 parts of deionized water were mixed and stirred for 30 minutes, 5 parts of L-tyrosine and 1 part of dicyandiamide curing low-temperature accelerator (UR400) were added and mixed and stirred for 30 minutes to prepare a water-based epoxy insulating paint.

[0043] Example 3

[0044] Under the protection of nitrogen, 50 parts of tung oil and 12 parts of maleic anhydride were mixed evenly, and reacted at 135°C for 2 hours to obtain tung oil anhydride adduct; 14 parts of tung oil anhydride adduct, 2 parts of n-butanol and propylene glycol methyl ether were mixed evenly, 5 parts of polyethylene glycol were added, reacted at 125°C for 3 hours, cooled to 95°C, 1 part of triethylamine was added and 30 parts of dissolved epoxy resin were added dropwise, and continued to react for 3 hours, cooled to 65°C and stirred for 50 minutes, cooled to room temperature to end nitrogen protection, neutralized to pH 7.0 with ammonia water, and epoxy resin modified tung oil water-based resin was obtained; wherein, 20 parts of epoxy resin were preliminarily dissolved in a mixed solution of 80 parts of n-butanol and propylene glycol methyl ether and stirred at 65°C for 30 minutes to obtain dissolved epoxy resin, and the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether was 2:3.

[0045] After 10 parts of Ti3C2 nanosheets were placed in a ball mill and ball-milled at a speed of 500r / min for 60 minutes, 10 parts of NH2-MIL-101 (CAS No.: 1414869-95-6), 1.5 parts of dopamine, and 5 parts of ground Ti3C2 nanosheets were added to 20-30 parts of Tris-HCl buffer solution. After sealed and stirred at room temperature for 16 hours, the supernatant was discarded by centrifugation and dried for 24 hours to obtain DA-MOF / Ti3C2.

[0046] After 2.5 parts of DA-MOF / Ti3C2, 70 parts of epoxy resin modified tung oil water-based resin, and 80 parts of deionized water were mixed and stirred for 60 minutes, 10 parts of L-tyrosine and 2.5 parts of dicyandiamide curing low-temperature accelerator (UR400) were added and mixed and stirred for 60 minutes to prepare a water-based epoxy insulating paint.

[0047] Example 4

[0048] Under the protection of nitrogen, 46 parts of tung oil and 11 parts of maleic anhydride were mixed evenly, and reacted at 130°C for 2 hours to obtain tung oil anhydride adduct; 13 parts of tung oil anhydride adduct, 1.8 parts of n-butanol and propylene glycol methyl ether were mixed evenly, 4 parts of polyethylene glycol were added, reacted at 120°C for 3 hours, cooled to 95°C, 0.6 parts of triethylamine were added dropwise, and 28 parts of dissolved epoxy resin were added dropwise to continue the reaction for 2.5 hours, and then cooled to 95°C. The mixture was heated to 65°C and stirred for 45 minutes, then cooled to room temperature to terminate nitrogen protection, and the pH value was neutralized to 7.1 with ammonia water to obtain epoxy resin-modified tung oil water-based resin; wherein, 20 parts of epoxy resin were preliminarily dissolved in a mixed solution of 80 parts of n-butanol and propylene glycol methyl ether and stirred at 65°C for 30 minutes to obtain dissolved epoxy resin, and the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether was 2:3.

[0049] After 10 parts of Ti3C2 nanosheets were placed in a ball mill and ball-milled at a speed of 500r / min for 55 minutes, 7 parts of NH2-MIL-101 (CAS No.: 1414869-95-6), 1.2 parts of dopamine, and 2 parts of ground Ti3C2 nanosheets were added to 25 parts of Tris-HCl buffer solution. After sealed and stirred at room temperature for 14 hours, the supernatant was discarded by centrifugation and dried for 16 hours to obtain DA-MOF / Ti3C2.

[0050] After 1.8 parts of DA-MOF / Ti3C2, 65 parts of epoxy resin modified tung oil water-based resin, and 75 parts of deionized water were mixed and stirred for 45 minutes, 6 parts of L-tyrosine and 2 parts of dicyandiamide curing low-temperature accelerator (UR400) were added and mixed and stirred for 45 minutes to prepare a water-based epoxy insulating paint.

[0051] Example 5

[0052] Under the protection of nitrogen, 40 parts of tung oil and 10 parts of maleic anhydride were mixed evenly, and reacted at 130°C for 2 hours to obtain tung oil anhydride adduct; 14 parts of tung oil anhydride adduct, 1.4 parts of a mixed solution of n-butanol and propylene glycol methyl ether were mixed evenly, 2 parts of polyethylene glycol were added, reacted at 115°C for 2 hours, cooled to 95°C, 1 part of triethylamine was added and 25 parts of dissolved epoxy resin were added dropwise, and continued to react for 2 hours, cooled to 65°C and stirred for 35 minutes, cooled to room temperature to end nitrogen protection, neutralized to pH 7.0 with ammonia water, and epoxy resin modified tung oil water-based resin was obtained; wherein, 20 parts of epoxy resin were preliminarily dissolved in a mixed solution of 80 parts of n-butanol and propylene glycol methyl ether and stirred at 65°C for 30 minutes to obtain dissolved epoxy resin, and the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether was 2:3.

[0053] After 10 parts of Ti3C2 nanosheets were placed in a ball mill and ball-milled at a speed of 500r / min for 60 minutes, 6-10 parts of NH2-MIL-101 (CAS No.: 1414869-95-6), 0.6 parts of dopamine, and 4 parts of ground Ti3C2 nanosheets were added to 26 parts of Tris-HCl buffer solution. After sealed and stirred at room temperature for 15 hours, the supernatant was discarded by centrifugation and dried for 22 hours to obtain DA-MOF / Ti3C2.

[0054] After 2.3 parts of DA-MOF / Ti3C2, 55 parts of epoxy resin modified tung oil water-based resin, and 70 parts of deionized water were mixed and stirred for 60 minutes, 10 parts of L-tyrosine and 1 part of dicyandiamide curing low-temperature accelerator (UR400) were added and mixed and stirred for 30 minutes to prepare a water-based epoxy insulating paint.

[0055] Example 6

[0056] Under the protection of nitrogen, 45 parts of tung oil and 12 parts of maleic anhydride were mixed evenly, and reacted at 125°C for 2 hours to obtain tung oil anhydride adduct; 13 parts of tung oil anhydride adduct, 1.6 parts of n-butanol and propylene glycol methyl ether were mixed evenly, 2-5 parts of polyethylene glycol were added, reacted at 110°C for 2.5 hours, cooled to 95°C, 0.8 parts of triethylamine were added, and 27 parts of dissolved epoxy resin were added dropwise, and the reaction was continued for 2.5 hours. , cool to 65°C and stir for 45 minutes, cool to room temperature to end nitrogen protection, neutralize with ammonia water to pH 7.0, and obtain epoxy resin modified tung oil water-based resin; wherein, 20 parts of epoxy resin are preliminarily dissolved in a mixed solution of 80 parts of n-butanol and propylene glycol methyl ether and stirred at 65°C for 30 minutes to obtain dissolved epoxy resin, and the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether is 2:3.

[0057] After 10 parts of Ti3C2 nanosheets were placed in a ball mill and ball-milled at a speed of 500r / min for 40 minutes, 10 parts of NH2-MIL-101 (CAS No.: 1414869-95-6), 1.5 parts of dopamine, and 2 parts of ground Ti3C2 nanosheets were added to 30 parts of Tris-HCl buffer solution. After sealed and stirred at room temperature for 16 hours, the supernatant was discarded by centrifugation and dried for 24 hours to obtain DA-MOF / Ti3C2.

[0058] After 2.5 parts of DA-MOF / Ti3C2, 50 parts of epoxy resin modified tung oil water-based resin, and 60 parts of deionized water were mixed and stirred for 60 minutes, 5 parts of L-tyrosine and 1.8 parts of dicyandiamide curing low-temperature accelerator (UR400) were added and mixed and stirred for 55 minutes to prepare a water-based epoxy insulating paint.

[0059] The present invention also carries out comparative examples and related tests.

[0060] Comparative Example 1

[0061] Comparative Example 1 uses qualified insulating paint on the market, such as commercially available 1146 epoxy drip insulating paint.

[0062] Comparative Example 2

[0063] Compared with Example 1, the only difference is that DA-MOF / Ti3C2 is not prepared, that is: after 10 parts of Ti3C2 nanosheets are put into a ball mill and ball-milled at a speed of 500 r / min for 50 minutes, 7 parts of NH2-MIL-101 (CAS No.: 1414869-95-6) and 3 parts of ground Ti3C2 nanosheets are added to 25 parts of Tris-HCl buffer solution, sealed and stirred at room temperature for 14 hours, centrifuged and the supernatant was discarded, and dried for 18 hours to obtain MOF / Ti3C2; the remaining raw materials and steps are consistent with Example 1, and finally a water-based epoxy insulating paint is obtained.

[0064] Comparative Example 3

[0065] Compared with Example 1, the only difference is that DA-MOF / Ti3C2 is not added as filler, and the remaining raw materials and steps are consistent with Example 1, and finally a water-based epoxy insulating paint is prepared.

[0066] Comparative Example 4

[0067] Compared with Example 1, the only difference is that L-tyrosine is not used as a curing agent, and the other raw materials and steps are consistent with Example 1, that is, after 2 parts of DA-MOF / Ti3C2, 60 parts of epoxy resin modified tung oil water-based resin, and 70 parts of deionized water are mixed and stirred for 50 minutes, 6 parts of diaminodiphenylmethane (DDM) and 2 parts of dicyandiamide curing low-temperature accelerator (UR400) are added and mixed and stirred for 50 minutes to prepare a water-based epoxy insulating paint.

[0068] Performance testing

[0069] The waterborne epoxy insulating varnishes prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to basic performance tests of viscosity, bonding strength, volatile organic matter content, open stability, and surface drying according to the national standard GB / T1981.6-2014 Electrical Insulation Paint Part 6: Environmentally Friendly Waterborne Impregnating Varnish. The results are shown in Table 1.

[0070] Table 1

[0071]

[0072] It can be seen from Table 1 that the basic properties of the water-based insulating varnishes prepared in Examples 1 to 6 all meet the national standard GB / T1981.6-2014 Electrical Insulation Paint Part 6: Environmentally Friendly Water-Based Impregnating Varnish, wherein viscosity (23°C±1°C): 40~110s; bonding strength (spiral coil method, 23°C±2°C) ≥60N; volatile organic matter content ≤15%; open stability (viscosity increase) 50°C / 96h≤2.0 times; surface drying (130°C±2°C) ≤1h.

[0073] The water-based epoxy insulating varnish prepared by Examples 1 to 6 and Comparative Examples 1 to 4 was used, and a copper sheet was selected as a substrate with a size of 100 mm × 75 mm × 0.1 mm. The surface of the copper sheet was first polished and wiped clean, and a paint film of the insulating varnish was prepared by an immersion method. The film was then placed in a UV test box for 1 hour. Finally, the paint film was obtained for testing of temperature index, acid resistance, alkali resistance, electrical strength, and volume resistivity. Among them, the temperature index is tested according to the national standard GB / T1981.6-2014, the acid resistance is tested according to the GB / T9274-1988 test method, the alkali resistance is tested according to the GB / T9265-2009 test method, and the electrical strength and volume resistivity of the insulating paint film are measured according to the GB / T1408.1-2016 test method for electrical strength of insulating materials Part 1: Test under power frequency and GB / T1410-2006 test method for volume resistivity and surface resistivity of solid insulating materials. The relevant performance test results are shown in Table 2.

[0074] Table 2

[0075]

[0076] It can be seen from Table 2 that Examples 1 to 6 have better heat resistance, acid and alkali resistance, volume resistivity and electrical strength than qualified insulating varnishes available on the market. Compared with Comparative Examples 2 and 3, the corrosion resistance, insulation and thermal stability of the water-based insulating varnish with the addition of DA-MOF / Ti3C2 are significantly improved.

[0077] The waterborne epoxy insulating varnish prepared in Example 1 and Comparative Examples 1 to 4 was subjected to an electrical strength test of the paint film prepared as described above after being immersed in water for 24 hours. The electrical insulation strength can be used as an important parameter index to measure the insulation performance of insulating materials. The insulation performance of insulating varnish can be directly reflected by measuring the electrical insulation strength. The test results are shown in FIG. Figure 1 As shown, the higher the electrical strength of the insulating paint film, the better the insulation performance of the corresponding insulating paint. It can be clearly seen in the figure that the electrical strength of the paint film prepared in Example 1 is significantly higher than that of Comparative Examples 1 to 3 within 0 to 24 hours, and the electrical strength does not change significantly during the immersion process.

[0078] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A production process of water-based epoxy insulating varnish, characterized in that: The following steps are involved: S1, uniformly mixing a mixed solution of tung oil anhydride adduct, n-butanol and propylene glycol methyl ether, adding polyethylene glycol for reaction, cooling, adding triethylamine and dissolved epoxy resin for further reaction, cooling and stirring to obtain epoxy resin modified tung oil waterborne resin; the tung oil anhydride adduct is obtained by uniformly mixing tung oil and maleic anhydride and reacting; S2, adding the metal organic framework, dopamine, and ground Ti3C2 nanosheets into a Tris-HCl buffer solution, sealing and stirring, centrifuging, discarding the supernatant, and drying to obtain DA-MOF / Ti3C2; S3. After mixing DA-MOF / Ti3C2, epoxy resin-modified tung oil water-based resin, and deionized water, L-tyrosine is added and mixed to prepare a water-based epoxy insulating paint.

2. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: The tung oil anhydride adduct in step S1 is obtained by uniformly mixing tung oil and maleic anhydride and reacting them at 125-135° C. for 1.5-2 hours; the mass ratio of n-butanol to propylene glycol methyl ether in the mixed solution of n-butanol and propylene glycol methyl ether in step S1 is 2:

3.

3. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: In the step S1, the polyethylene glycol is added to react at a temperature of 110-125° C. for 2-3 hours, then the temperature is lowered to 95° C., triethylamine is added dropwise, and the dissolved epoxy resin is added to continue the reaction for 2-3 hours, then the temperature is lowered to 65° C. and stirred for 30-50 minutes to obtain an epoxy resin-modified tung oil water-based resin; the dissolved epoxy resin is obtained by dissolving the epoxy resin in a mixed solution of n-butanol and propylene glycol methyl ether and stirring at 65° C. for 30 minutes.

4. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: The preparation process of the epoxy resin modified tung oil water-based resin in step S1 is carried out under nitrogen protection, and the nitrogen protection is terminated after cooling and stirring, and ammonia water is used to neutralize the pH to 7.0-7.

2.

5. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: In the step S2, the ground Ti3C2 nanosheets are obtained by placing the Ti3C2 nanosheets in a ball mill and milling them at a speed of 500 r / min for 40 to 60 minutes; the metal organic framework is NH2-MIL-101.

6. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: In step S2, the sealing and stirring time is 12 to 16 hours, and the drying time is 12 to 24 hours.

7. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: In the step S3, when L-tyrosine is added and mixed, a dicyandiamide curing low-temperature accelerator is also added and mixed.

8. The production process of a water-based epoxy insulating varnish according to claim 1, characterized in that: The mixing and stirring time in step S3 is 30 to 60 minutes.

9. A water-based epoxy insulating varnish, characterized in that: The water-based epoxy insulating varnish is prepared by the production process of claim 5, comprising the following raw materials in parts by weight: 1 to 2.5 parts of DA-MOF / Ti3C2, 50 to 70 parts of epoxy resin-modified tung oil water-based resin, 50 to 80 parts of deionized water, and 5 to 10 parts of L-tyrosine; and also comprising 1 to 2.5 parts of a dicyandiamide curing low-temperature accelerator.

10. The water-based epoxy insulating varnish according to claim 9, characterized in that: The raw materials of the epoxy resin modified tung oil water-based resin include 10-14 parts of tung oil anhydride adduct calculated by weight, 1.4-2 parts of a mixed solution of n-butanol and propylene glycol methyl ether, 2-5 parts of polyethylene glycol, 0.5-1 part of triethylamine, and 25-30 parts of dissolved epoxy resin; the raw materials of the DA-MOF / Ti3C2 include 6-10 parts of NH2-MIL-101 calculated by weight, 0.6-1.5 parts of dopamine, 1-5 parts of ground Ti3C2 nanosheets, and 20-30 parts of Tris-HCl buffer solution; wherein the raw materials of the tung oil anhydride adduct include 40-50 parts of tung oil and 10-12 parts of maleic anhydride calculated by weight.

Images