Titanium dioxide nanotube modified insulating paint, and preparation method and use thereof

Abstract

The present application relates to a kind of titanium dioxide nanotube modified insulating paint and its preparation method and purposes.The raw materials of the insulating paint include polyol, acid anhydride, crosslinking monomer and initiator, and the raw materials of the insulating paint also include modified titanium dioxide nanotube, which is prepared by modifying titanium dioxide nanotube with silane coupling agent.The present application can significantly improve the comprehensive performance of insulating paint such as mechanical properties and electrical properties by adding modified titanium dioxide nanotube with silane coupling agent into the insulating paint with polyester prepared by polymerization of polyol and acid anhydride as main component, and controlling the specific addition time of modified titanium dioxide nanotube, i.e., adding in situ polymerization of polyester resin.

Description

TECHNICAL FIELD

[0001] The present application relates to a titanium dioxide nanotube modified insulating paint and a preparation method and use thereof. BACKGROUND

[0002] With the continuous development of motor technology, the power of the motor is continuously improved, and the power consumption of the motor is also improved at the same time, so the requirements of the motor field for the insulating paint are also higher and higher, and the insulating paint is required to have excellent electrical properties and mechanical properties at the same time, and the viscosity of the insulating paint is low, the fluidity is good, the solid content is high, and the insulating paint is convenient for penetration and filling of the impregnated object.

[0003] Chinese patent CN110845947A discloses a heat-conducting insulating paint and a preparation method thereof, the raw materials of the heat-conducting insulating paint include polyol, acid anhydride, modified carbon nanotube, crosslinking monomer and initiator, wherein the modified carbon nanotube is prepared by simultaneously growing a silica layer and grafting a silane coupling agent with a vinyl group on the surface of the carboxylated carbon nanotube, the heat-conducting performance of the heat-conducting insulating paint is excellent, but the mechanical properties and electrical properties thereof still need to be further improved. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a titanium dioxide nanotube modified insulating paint to solve the defects and deficiencies of the prior art, which has excellent electrical properties and mechanical properties and can meet the high requirements of the motor field for the insulating paint.

[0005] To solve the above technical problems, a technical solution adopted by the present application is as follows:

[0006] A titanium dioxide nanotube modified insulating paint, the raw materials of the insulating paint include polyol, acid anhydride, crosslinking monomer and initiator, and the raw materials of the insulating paint further include modified titanium dioxide nanotube, and the modified titanium dioxide nanotube is prepared by modifying titanium dioxide nanotube with a silane coupling agent.

[0007] In some embodiments, the raw materials of the insulating paint include acid anhydride 28-37 parts, polyol 20-26 parts, modified titanium dioxide nanotube 1-10 parts, crosslinking monomer 20-28 parts and initiator 0.5-2 parts in terms of mass fraction.

[0008] In some embodiments, the silane coupling agent is selected from one or more combinations of KH550, KH560 and KH570.

[0009] In some embodiments, the modified titanium dioxide nanotube is prepared by mixing titanium dioxide nanotube with an ethanol solution of silane coupling agent and drying.

[0010] In some embodiments, the anhydride is a mixture of isophthalic anhydride and maleic anhydride, the polyol is 1,2-propanediol, and the molar ratio of the anhydride to the polyol is 0.9-1.1:1.

[0011] In some embodiments, the crosslinking monomer is styrene.

[0012] In some embodiments, the initiator is dibenzoyl peroxide.

[0013] In some embodiments, the raw materials of the insulating paint include, in mass parts, isophthalic anhydride 8-12 parts, maleic anhydride 20-25 parts, 1,2-propanediol 20-26 parts, modified titanium dioxide nanotubes 1-10 parts, dibenzoyl peroxide 0.5-2 parts, styrene 20-28 parts, catalyst 0.01-0.5 parts, and polymerization inhibitor 0.01-0.1 parts.

[0014] The present application further provides a method for preparing the aforementioned insulating paint modified with titanium dioxide nanotubes, which comprises the following steps: weighing the raw materials according to the formula, then adding the polyol, the anhydride, and the modified titanium dioxide nanotubes into a reaction vessel, stirring under the protection of a protective gas, heating to 155-165℃, reacting until the acid value is <50 mg KOH / g, heating to 170-180℃, reacting until the acid value is 30-40 mg KOH / g, heating to 195-205℃, and reacting until the acid value is 5-20 mg KOH / g to end the reaction; then cooling to 20-35℃, adding the remaining raw materials, and mixing to prepare the insulating paint modified with titanium dioxide nanotubes.

[0015] In some embodiments, the method further comprises the steps of preparing the titanium dioxide nanotubes by hydrothermal reaction using an anatase-phase titanium dioxide powder, and preparing the modified titanium dioxide nanotubes by mixing the titanium dioxide nanotubes with an ethanol solution of a silane coupling agent and drying.

[0016] The present application further provides the use of the aforementioned insulating paint modified with titanium dioxide nanotubes in an insulating paint for electric machines.

[0017] Thanks to the use of the above technical solutions, the present application has the following advantages compared with the prior art:

[0018] The present application adds the modified titanium dioxide nanotube after the silane coupling agent is modified in the insulating paint prepared by the polyester obtained by polymerization of polyol and acid anhydride as the main component, and controls the specific adding time of the modified titanium dioxide nanotube, that is, adding in the in-situ polymerization of the polyester resin, and the modified titanium dioxide nanotube is added into the reaction system at the same time as the polyol and the acid anhydride, so that on the one hand, the surface energy of the titanium dioxide nanotube is reduced, and it is easy to disperse uniformly in the resin matrix, which obviously improves the problem that the inorganic particles are easy to agglomerate and disperse unevenly in the prior art, and on the other hand, the modified titanium dioxide nanotube can participate in the crosslinking network of the polyester resin, which can obviously improve the comprehensive performance of the insulating paint, such as mechanical properties and electrical properties, and improve the problem that the comprehensive performance of the high molecular matrix insulating paint is not excellent enough when used in the motor field in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The morphology of the modified titanium dioxide nanotube in Example 1. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be described in detail below in combination with specific examples, so that those skilled in the art can better understand and implement the technical solutions of the present application, but the present application is not limited in the scope of the described examples.

[0021] Example 1

[0022] The present embodiment provides an insulating paint modified by titanium dioxide nanotube, and the preparation method is as follows:

[0023] 1) Preparation of titanium dioxide nanotube: in a high-pressure reaction kettle, add anatase phase titanium dioxide powder (particle size about 500 nanometers) and 10M concentration NaOH solution according to the mass ratio of 1:5, seal and hydrothermal reaction at 140℃ for 72 hours; after the reaction kettle is cooled, the white solid is removed from the high-pressure reaction kettle and washed with 0.1M hydrochloric acid (HCl) solution, then washed with a large amount of deionized water until the pH value of the outflowing solution is neutral. Finally, the titanium dioxide nanotube product is dried at 80℃ to obtain the titanium dioxide nanotube.

[0024] 2) Preparation of modified titanium dioxide nanotube: the titanium dioxide nanotube obtained in step 1) is added to anhydrous ethanol solution of silane coupling agent KH560 (the volume ratio of silane coupling agent and anhydrous ethanol is 1:10), the mass percentage of titanium dioxide nanotube in anhydrous ethanol solution is 10%, and ultrasonic dispersion treatment is carried out for 10 minutes; then oil bath treatment is carried out at 400℃ for 4 hours; after the oil bath is finished, the flocculation obtained by reaction is repeatedly washed with anhydrous ethanol and deionized water, suction filtered, and naturally dried at room temperature to obtain the modified titanium dioxide nanotube, and the morphology is as follows: Figure 1As shown, the diameter of the tube is 10-20 nanometers, and the length is 100-500 nanometers.

[0025] 3) Preparation of insulating paint: raw materials according to mass parts, including 4 parts of modified titanium dioxide nanotubes obtained in step 2), 11 parts of isophthalic anhydride, 23 parts of maleic anhydride, 24 parts of 1,2-propanediol, 1 part of dibenzoyl peroxide, 0.05 parts of cobalt naphthenate, 24 parts of styrene, 0.02 parts of hydroquinone; according to the formula, each raw material is weighed, then isophthalic anhydride, maleic anhydride, 1,2-propanediol, and modified titanium dioxide nanotubes are added to a reaction vessel, stirred under the protection of protective gas, heated to 160°C, and reacted until the acid value is 45±1 mg KOH / g, heated to 175°C, and reacted until the acid value is 35±1 mg KOH / g, heated to 200°C, and reacted until the acid value is 12±1 mg KOH / g to end the reaction; then cooled to room temperature, the remaining raw materials are added, mixed and reacted to obtain an insulating paint.

[0026] Example 2

[0027] This example provides a modified insulating paint of titanium dioxide nanotubes, and the preparation method is basically the same as that of Example 1, except that the mass of modified titanium dioxide nanotubes in step 3) is adjusted to 2 parts.

[0028] Example 3

[0029] This example provides a modified insulating paint of titanium dioxide nanotubes, and the preparation method is basically the same as that of Example 1, except that the mass of modified titanium dioxide nanotubes in step 3) is adjusted to 8 parts.

[0030] Example 4

[0031] This example provides a modified insulating paint of titanium dioxide nanotubes, and the preparation method is basically the same as that of Example 1, except that the mass of modified titanium dioxide nanotubes in step 3) is adjusted to 10 parts.

[0032] Comparative Example 1

[0033] This comparative example provides a modified insulating paint of titanium dioxide nanotubes, and the preparation method is basically the same as that of Example 1, except that step 2) is not performed, i.e., the titanium dioxide nanotubes are not modified, and the titanium dioxide nanotubes prepared in step 1) are directly used in step 3).

[0034] Comparative Example 2

[0035] The comparative example 1 provides a titanium dioxide nanotube modified insulating paint, and its preparation method is basically the same as that of the example 1, and the difference is only that the anatase phase titanium dioxide powder (particle size of about 500 nanometers) is directly used instead of the titanium dioxide nanotube. That is, step 1) is not performed, the titanium dioxide nanotube in step 2) is replaced by the anatase phase titanium dioxide powder (particle size of about 500 nanometers), and it is used in step 3).

[0036] Comparative example 3

[0037] The comparative example 1 provides a titanium dioxide nanotube modified insulating paint, and its preparation method is basically the same as that of the example 1, and the difference is only that the anatase phase titanium dioxide powder (particle size of about 500 nanometers) is directly used instead of the titanium dioxide nanotube. That is, step 1) is not performed, the titanium dioxide nanotube in step 2) is replaced by the anatase phase titanium dioxide powder (particle size of about 500 nanometers), and it is used in step 3).

[0038] The raw materials are weighed according to the formula, then the isophthalic anhydride, maleic anhydride and 1,2-propanediol are added into the reaction container, and the temperature is raised under the protection of the protective gas. The temperature is raised to 160℃, and the reaction is carried out until the acid value is 45±1mg KOH / g. The temperature is raised to 175℃, and the reaction is carried out until the acid value is 35±1mg KOH / g. The temperature is raised to 200℃, and the reaction is carried out until the acid value is 12±1mg KOH / g to end the reaction. Then it is cooled to room temperature, and the modified titanium dioxide nanotube and the remaining raw materials are added and mixed to obtain the insulating paint.

[0039] Comparative example 4

[0040] The comparative example 1 provides a titanium dioxide nanotube modified insulating paint, and its preparation method is basically the same as that of the example 1, and the difference is only that the anatase phase titanium dioxide powder (particle size of about 500 nanometers) is directly used instead of the titanium dioxide nanotube. That is, step 1) is not performed, the titanium dioxide nanotube in step 2) is replaced by the anatase phase titanium dioxide powder (particle size of about 500 nanometers), and it is used in step 3).

[0041] Comparative example 5

[0042] The comparative example 1 provides a titanium dioxide nanotube modified insulating paint, and its preparation method is basically the same as that of the example 1, and the difference is only that the anatase phase titanium dioxide powder (particle size of about 500 nanometers) is directly used instead of the titanium dioxide nanotube. That is, step 1) is not performed, the titanium dioxide nanotube in step 2) is replaced by the anatase phase titanium dioxide powder (particle size of about 500 nanometers), and it is used in step 3).

[0043] The flame-retardant insulating paint prepared in the above examples 1-4 and comparative examples 1-5 is sprayed on the substrate, and the performance of the cured coating film and the performance of the cured coating film after being soaked in ATF oil for 3 months are tested according to GB / 15022.2-2017, and the results are shown in Table 1. Wherein “-” means that the data does not exist under this condition, because the insulating paint is first cured and solidified, and then soaked in ATF oil for 3 months, and the data will not be tested after 3 months.

[0044] Table 1 Example, Comparative Example Cured Coating Film Properties

[0045]

[0046] From the above Table 1, it can be seen that by adding the modified titanium dioxide nanotube after adding the silane coupling agent to the insulating paint prepared by polymerization of a polyol and an anhydride as a main component, the mechanical properties and electrical properties of the insulating paint can be improved.

[0047] The modified titanium dioxide nanotube is added at a specific time, i.e., during in-situ polymerization of the polyester resin, so that the comprehensive properties of the insulating paint, such as the mechanical properties and electrical properties, can be significantly improved.

[0048] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

[0049] The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise values. The ranges and values should be construed as being approximate. The exact values are understood to be within the range. The endpoints of the ranges and any values claimed herein are not limited to the precise

Claims

1. A titanium dioxide nanotube modified insulating paint, the raw materials of which comprise polyol, anhydride, crosslinking monomer and initiator, characterized in that: The raw materials of the insulating paint also include modified titanium dioxide nanotubes, which are prepared by modifying titanium dioxide nanotubes with a silane coupling agent; and the modified titanium dioxide nanotubes are added in situ during the polymerization of the polyol, the acid anhydride and the crosslinking monomer when the insulating paint is prepared. The raw materials of the insulating paint include, in mass fraction, 28-37 parts of the acid anhydride, 20-26 parts of the polyol, 1-10 parts of the modified titanium dioxide nanotubes, 20-28 parts of the crosslinking monomer, and 0.5-2 parts of the initiator. The acid anhydride is a mixture of isophthalic anhydride and maleic anhydride, the polyol is 1,2-propanediol, and the molar ratio of the acid anhydride to the polyol is 0.9-1.1:

1. The crosslinking monomer is styrene.

2. The titania nanotube-modified insulating paint according to claim 1, characterized by: The silane coupling agent is selected from one or more of a combination of KH550, KH560 and KH570.

3. The titania nanotube-modified insulating paint according to claim 1, characterized by: The modified titanium dioxide nanotubes are prepared by mixing titanium dioxide nanotubes with an ethanol solution of the silane coupling agent and drying.

4. The titania nanotube-modified insulating paint according to claim 1, characterized by: The initiator is dibenzoyl peroxide.

5. The titania nanotube modified insulating paint according to claim 1, characterized by: The raw materials of the insulating paint include, in mass fraction, 8-12 parts of isophthalic anhydride, 20-25 parts of maleic anhydride, 20-26 parts of 1,2-propanediol, 1-10 parts of the modified titanium dioxide nanotubes, 0.5-2 parts of dibenzoyl peroxide, 20-28 parts of styrene, 0.01-0.5 parts of the catalyst and 0.01-0.1 parts of the polymerization inhibitor.

6. A method for preparing the modified titania nanotube-based insulating paint according to any one of claims 1 to 5, characterized by: The method The method includes the following steps: weighing each raw material according to the formula, then adding the polyol, the acid anhydride and the modified titanium dioxide nanotubes into a reaction container, stirring under the protection of a protective gas, heating to 155-165℃, reacting until the acid value is <50 mgKOH / g, heating to 170-180℃, reacting until the acid value is 30-40 mgKOH / g, heating to 195-205℃, and ending the reaction when the acid value is 5-20 mgKOH / g; then cooling to 20-35℃, adding the remaining raw materials, and mixing and reacting to prepare the insulating paint modified with the titanium dioxide nanotubes.

7. The method of claim 6, wherein: The method also includes the steps of preparing the titanium dioxide nanotubes by hydrothermal reaction of anatase titanium dioxide powder, and preparing the modified titanium dioxide nanotubes by mixing the titanium dioxide nanotubes with an ethanol solution of the silane coupling agent and drying.

8. The application of the insulating paint modified with the titanium dioxide nanotubes according to any one of claims 1-5 in an insulating paint for electric machines.

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