WO2023221294A1 - Method for identifying ultraviolet radiation aging resistance degree of coating on insulator - Google Patents

Abstract

A method for identifying an ultraviolet radiation aging resistance degree of a coating on an insulator, comprising: carrying out focused sampling from a surface of a coating on an insulator to be identified to obtain a sample; carrying out a hydrophobicity test on the sample and determining a static contact angle of the sample; determining a hydrophobicity score according to the static contact angle of the sample; carrying out a Fourier transform infrared spectroscopy test on the sample and determining the heights of four absorption peaks Si-O-Si, Si(CH₃)₂, Si-CH₃ and CH₃(C-H) of the infrared spectrum; determining a chemical bond score; and jointly determining a total score of ultraviolet radiation resistance of the sample according to the hydrophobicity score and the chemical bond score, so as to determine an aging degree of the sample. According to the method, microscopic and macroscopic multi-level indexes are considered at the same time, the differentiation precision on ultraviolet radiation resistance of a coating on an insulator can be improved, and an ultraviolet radiation aging condition of the coating on the insulator is effectively identified.

Description

A method for identifying the UV radiation aging resistance of coatings on insulators Technical field

The present invention relates to the field of insulator coating evaluation, and specifically relates to a method for identifying the ultraviolet radiation aging resistance of a coating on an insulator.

Background technique

The silicone rubber coating on the surface of the insulator will gradually age during operation. This process will cause the siloxane molecular chain to break, cross-link and oxidize the side chain groups, generate hydrophilic products such as silanol, reduce the hydrophobicity of the coating, and accumulate As the amount of pollution increases, the risk of flashover along the surface increases. At the same time, small molecule products produced by molecular chain breakage will also be washed away from the coating surface by rain or cleaning agents, destroying the surface integrity of the coating, exposing the inorganic fillers inside the coating, increasing the surface roughness of the coating, and further Increase the amount of dirt accumulated and reduce the insulation performance. Currently, the commonly used single index grading evaluation methods such as changes in static contact angle, changes in surface element content, and changes in microscopic group content are relatively simple in principle and low in operational difficulty. However, there are problems with incomplete inspection of indicators and a high misjudgment rate. For silicon The effect of judging the radiation resistance of rubber coatings is not ideal. Therefore, it is necessary to propose a more ideal method for identifying the UV radiation aging resistance of coatings on insulators.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for identifying the UV radiation aging resistance of a coating on an insulator to solve at least one drawback of the prior art.

In order to achieve the above objects and other related objects, the present invention provides a method for identifying the UV radiation aging resistance of a coating on an insulator, including:

Samples are obtained by taking focused samples from the coating surface on the insulator to be identified;

Conduct a hydrophobicity test on the sample piece to determine the static contact angle θ _t of the sample piece;

Determine whether the static contact angle θ _t is lower than a preset angle;

If the static contact angle θ _t is lower than the preset angle, it is determined that the life of the sample is terminated;

If the static contact angle θ _t is not lower than the preset angle, determine the hydrophobicity score C ₁ of the sample based on the static contact angle θ _t and the preset standard static contact angle θ _s ;

Fourier transform infrared spectrum testing was performed on the sample to determine the heights of the four absorption peaks of Si-O-Si, Si(CH ₃ ) ₂ , Si-CH ₃ and CH ₃ (CH) in the infrared spectrum, which were recorded as H _Si respectively. _-O-Si , H _Si(CH3)2 , H _Si-CH3 and H _CH3(CH) ;

Determine whether the height of any one of the four absorption peaks is less than its corresponding preset height, and each absorption peak corresponds to a preset height;

If the height of any one of the four absorption peaks is less than its corresponding preset height, it is determined that the life of the sample is terminated;

If the height of any one of the four absorption peaks is not less than its corresponding preset height, then the characteristic absorption peak height H t of the sample is determined based on the heights of the four absorption peaks, and the characteristic absorption peak height H _t of the sample is determined based on the preset height. The standard characteristic absorption peak height H _s determines the chemical bond score C ₂ of the sample;

According to the hydrophobicity score C ₁ and the chemical bond score C ₂ , determine the total ultraviolet radiation resistance score C of the sample;

The aging degree of the sample is determined based on the total UV radiation resistance score of the sample.

Optionally, the method further includes: cleaning the sample piece with absolute ethanol before the hydrophobicity test.

Optionally, performing a hydrophobicity test on the sample piece and determining the static contact angle of the sample piece includes: performing a preset number of measurements on the sample piece after the hydrophobicity test; and taking the measurement results of the preset number of times. Mean; determine the mean as the static contact angle of the sample.

Optionally, the preset angle is 80 degrees.

Optionally, the preset height corresponding to the absorption peak is 10% of its corresponding preset standard absorption peak height.

Optionally, the method for determining the characteristic absorption peak height H _t of the sample is:

Optionally, the method for determining the chemical bond score C ₂ of the sample is:

Optionally, the total ultraviolet radiation resistance score C of the sample is the weighted average of the hydrophobicity score C ₁ and the chemical bond score C ₂ .

Optionally, the method for determining the total ultraviolet radiation resistance score C of the sample is C=0.5C ₁ +0.5C ₂ .

Optionally, determining the aging degree of the sample based on the total score of the sample's resistance to ultraviolet radiation includes: comparing the total score of resistance to ultraviolet radiation with a preset score; if the total score of resistance to ultraviolet radiation If the total score is less than the preset score, the life of the sample is determined to be terminated; if the total score of UV resistance is not less than the preset score, the total score of UV resistance is used as the sample. The basis for identification of the aging resistance to UV radiation.

As mentioned above, the method of the present invention for identifying the UV radiation aging resistance of a coating on an insulator has the following beneficial effects:

1. The method used in the present invention takes into account both micro and macro multi-level indicators. Compared with the previous single indicator evaluation method, it is more comprehensive and can improve the accuracy of judging the UV radiation resistance of the coating on the insulator, and effectively identify the coating on the insulator. It can reduce the aging of ultraviolet radiation, reduce the probability of pollution flashover, and improve the practical safety of silicone rubber-coated insulators;

2. The method used in the present invention can effectively compare the UV radiation resistance of different types of silicone rubber coatings by standardizing the performance indicators of the silicone rubber coating;

3. The method used in the present invention combines the continuous score evaluation system with the graded judgment system, which can make the judgment results more consistent with the actual engineering requirements for the performance of silicone rubber coatings;

4. The method used in the present invention determines the remaining ultraviolet radiation resistance of the silicone rubber coating, and has a guiding role in supplementary spraying of the coating and other work.

Description of the drawings

Figure 1 is an exemplary flow chart of a method for identifying the UV radiation aging resistance of a coating on an insulator according to an embodiment of the present invention;

Figure 2 is an infrared spectrum diagram of No. 1 insulator and No. 2 insulator according to an embodiment of the present invention.

Detailed ways

The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, as long as there is no conflict, the following embodiments and the features in the embodiments can be combined with each other.

It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the drawings only show the components related to the present invention and do not follow the number, shape and number of components during actual implementation. Dimension drawing, in actual implementation, the type, quantity and proportion of each component can be arbitrarily changed, and the component layout type may also be more complex.

The purpose of this application is to identify the UV radiation aging resistance of the coating on the insulator to solve the shortcomings of the existing methods. It has good application prospects and very important practical significance.

The overall concept of this application is: first, focus on sampling the coating surface on the insulator to be identified to obtain a sample; then conduct a hydrophobicity test and Fourier transform infrared spectrum test on the sample, and determine the static contact angle and the height of different absorption peaks. It is also used to judge the UV radiation resistance of the sample.

FIG. 1 is an exemplary flow chart of a method for identifying the UV radiation aging resistance of a coating on an insulator according to an embodiment of the present invention.

In step 101, samples can be obtained by focusing on sampling the coating surface on the insulator to be identified. In some embodiments, samples may be taken from the upper surface of the uppermost insulator that has been exposed to ultraviolet irradiation for the longest time and with the highest intensity. In some embodiments, before sampling, a metal wire can be used to ground the charge to release the charge, and then the most contaminated or roughest part of the upper surface is selected for sampling. In some embodiments, a square sample with a size of 10mm*10mm can be taken. In other embodiments, the size of the sampled piece can also be other values, and the shape of the sampled piece can also be other shapes besides square, such as rectangle, circle, etc.

In step 102, a hydrophobicity test can be performed on the sample piece to determine the static contact angle θ _t of the sample piece. In some embodiments, the result of one measurement can be used as the static contact angle of the sample. In some embodiments, a preset number of measurements can be performed on the sample piece after the hydrophobicity test, and then the measurement results of the preset number of times are averaged, and then the average value is determined as the static contact angle of the sample piece. The preset number of times may be 2, 3, 4, 5, 6, 7, 8, etc.

In some embodiments, the sample may be cleaned first before performing the hydrophobicity test. The cleaning material used can be absolute ethanol or other materials. After cleaning, it can be left for a period of time (for example, 24 hours), and the hydrophobicity test can be performed again after the hydrophobicity is fully restored. In some embodiments, the sample can be placed on the sample stage, and the tilt angle of the sample stage can be adjusted to make the surface of the sample horizontal. Then, a precision injector can be used to drop 5 μL of deionized water onto the surface of the sample, and then the test can be adjusted. The focal length of the instrument camera is adjusted to make the water droplet outline as clear as possible, and finally the static contact angle measurement software is used to read the static contact angle of the sample.

In step 103, it may be determined whether the static contact angle θ _t is lower than a preset angle. The preset angle can be any value between 70 degrees and 90 degrees or any value with a height of 90 degrees, such as 70 degrees, 71 degrees, 72 degrees, 73 degrees, 74 degrees, 75 degrees, 76 degrees, 77 degrees, 78 degrees, 79 degrees, 80 degrees, 81 degrees, 82 degrees, 83 degrees, 84 degrees, 85 degrees, 86 degrees, 87 degrees, 88 degrees, 89 degrees, 90, etc.

If it is determined that the static contact angle θ _t is lower than the preset angle, then in step 104, it can be determined that the sample piece has lost its ability to withstand ultraviolet radiation, that is, the life of the sample piece has ended.

If it is determined that the static contact angle θ _t is not lower than the preset angle, then in step 105, the hydrophobicity score C of the sample can be determined based on the static contact angle θ _t and the preset standard static contact angle θ _{s. 1} . The standard static contact angle θ _s represents the static contact angle of the standard new sample. In some embodiments, the hydrophobicity score C ₁ of the sample can be determined according to Equation 1.

Among them, C1 is the hydrophobicity score of the sample, θ _t is the static contact angle measured by the sample, θ _s is the standard new sample (that is, the same coating of the same insulator without any ultraviolet radiation or other physical and chemical changes) The static contact angle of the sample below). In some embodiments, the hydrophobicity score C ₁ may be rounded to two decimal places. The hydrophobicity score of the sample is an indication of the sample's ability to withstand UV radiation on a macroscopic level.

In step 106, Fourier transform infrared spectrum testing can be performed on the sample to determine the heights of the four absorption peaks of Si-O-Si, Si(CH ₃ ) ₂ , Si-CH ₃ and CH ₃ (CH) in the infrared spectrum. They are recorded as H _Si-O-Si , H _Si(CH3)2 , H _Si-CH3 and H _CH3(CH) respectively.

In some embodiments, you can turn on the Fourier transform infrared spectrometer and the host controller and initialize the instrument, then place the blank piece on the sample stage of the tester, align it with the outlet of the fractionator, and then click the background button to test. background spectrum, then replace the blank piece with the sample to be tested, select the test mode to test the infrared spectrum, and finally mark the design characteristic peaks on the infrared spectrum, and the test results can be further saved.

It should be noted that step 106 can be performed at the same time as step 102, or step 102 can be performed first and then step 106, or step 106 can be performed first and then step 102. There is no limitation here.

In step 107, it may be determined whether the height of any one of the four absorption peaks is less than its corresponding preset height. Each absorption peak corresponds to a preset height. In some embodiments, the preset height corresponding to each absorption peak may be the preset standard absorption peak height corresponding to the absorption peak multiplied by a ratio. The proportion may be 10%, 15%, 20%, etc. or any other value. The height of the standard absorption peak is the four absorption peaks of Si-O-Si, Si(CH ₃ ) ₂ , Si-CH ₃ and CH ₃ (CH) in the infrared spectrum of the new standard sample when performing Fourier transform infrared spectroscopy testing. the height of.

If it is determined that the height of any one of the four absorption peaks is less than its corresponding preset height, then in step 104, it can be determined that the sample has lost its ability to withstand ultraviolet radiation, that is, its life has expired.

If it is determined that the height of any one of the four absorption peaks is not less than its corresponding preset height, then in step 108, the characteristic absorption peak height H of the sample can be determined based on the heights of the four absorption peaks. _t , and determine the chemical bond score C ₂ of the sample according to the preset standard characteristic absorption peak height H _s . In some embodiments, the standard characteristic absorption peak height H _s may represent the sum or weighted sum of the standard absorption peak heights of the four absorption peaks of the sample. The chemical bond score of the sample is an indication of the sample's ability to withstand UV radiation at a microscopic level.

In some embodiments, the characteristic absorption peak height H _t of the sample can be determined according to Equation 2:

In some embodiments, the characteristic absorption peak height H _t of the sample may be a weighted sum of the heights of the four absorption peaks.

In some embodiments, the chemical bond score _C2 of the sample can be determined according to Equation 3:

In step 109, the UV radiation resistance total score C of the sample can be determined based on the hydrophobicity score C ₁ and the chemical bond score C ₂ .

In some embodiments, the total ultraviolet radiation resistance score C of the sample can be determined according to Equation 4:

C=0.5C ₁ +0.5C ₂ . (Formula 4)

In some embodiments, the total ultraviolet radiation resistance score C of the sample can also be determined by summing the hydrophobicity score C ₁ and the chemical bond score C ₂ with other weights.

In step 110, the aging degree of the sample may be determined based on the total ultraviolet radiation resistance score C of the sample. In some embodiments, if the total ultraviolet radiation resistance score C of the sample is lower than a preset score, it can be determined that the sample has lost its ability to withstand ultraviolet radiation, that is, the life of the sample has ended. If the total UV radiation resistance score C of the sample is not lower than the preset score, the high or low score of C will be used as the basis for judging the level of UV radiation resistance. The higher the C, the stronger the remaining ability of the sample to withstand UV radiation, that is, the less severe the degree of aging; conversely, the smaller the C, the weaker the remaining ability of the sample to withstand UV radiation, that is, the more serious the degree of aging. In some implementations, the preset score may be 30 points, 35 points, 40 points, or any other value less than 50 points.

Specific examples are shown below to illustrate the technical solutions of the present invention.

This example is to test the ultraviolet radiation resistance of the silicone rubber coating of a suspended insulator in a coastal area of a country. The insulator has been used for 13 months. The No. 1 and No. 4 insulators suspended at the highest point among the insulator samples are selected. The specific operations include : The operator puts on nitrile gloves, places the grounding wire on the surface of the insulator, and releases the residual charges of the two insulators; selects the most contaminated area on the upper surface of the insulator, draws a 10mm*10mm sampling area with a pencil, and uses a blade to Cut the sample piece from the surface of the insulator; clean the sample piece removed from the insulator with absolute ethanol to remove dirt, place it on a flat and clean ceramic base, and dry it in a dark place for 24 hours; place the sample piece on the sample stage and adjust The tilt angle of the sample stage makes the surface of the sample horizontal; use a precision injector to drop 5 μL deionized water on the surface of the sample; adjust the focus of the tester camera to make the water droplet outline as clear as possible; use static contact angle measurement software to read out the static state of the sample The contact angle was measured three times continuously. The measurement results are shown in Table 1.

Samples	Reference standard samples	No. 1 insulator	No. 4 insulator
first test	110.4	109.8	110.8
second test	112.3	110.3	110.1
third test	111.8	109.5	109.1
Mean (rounded to one decimal place)	111.5	109.9	110.0

Table 1

Next, wipe off the water droplets on the surface of the sample with a non-woven cloth; turn on the Fourier transform infrared spectrometer tester and the host controller and initialize the instrument; since the instrument used in this test is more automated, there is no need to test the background spectrum, so the sample is directly placed on On the sample stage of the tester, align it with the light outlet of the beam splitter, select the test mode, and test the infrared spectrum. The infrared spectra of No. 1 insulator and No. 4 insulator are shown in Figure 2. The key characteristic peak heights of No. 1 insulator and No. 4 insulator are shown in Table 2.

Samples	Reference standard samples	No. 1 insulator	No. 4 insulator
Si-O-Si	1.07575	0.84506	0.92359
Si(CH 3 ) 2	1.14877	0.73868	0.67133

Si-CH 3	0.40063	0.3694	0.30828
CH 3 (CH)	0.09629	0.09866	0.09595

Table 2

Finally, the test results are processed (for example, the methods described in steps 105 and 108), and the hydrophobicity score (ie, macro-level score) of No. 1 insulator is 94.92 points, and the chemical bond score (ie, micro-level score) is 72.66 points. The total score is 83.8 points; the hydrophobicity score (i.e., macro-level score) of No. 4 insulator is 95.24 points, the chemical bond score (i.e., micro-level score) is 70.51 points, and the total score is 82.9 points.

It can be seen from the test results that the two insulators have good UV radiation resistance, that is, the aging is not serious and the overall performance decline is not obvious.

The above-described embodiments are only preferred embodiments to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be determined by the claims.

Claims (10)

1. A method for identifying the UV radiation aging resistance of coatings on insulators, which is characterized by including:

   Samples are obtained by taking focused samples from the coating surface on the insulator to be identified;

   Conduct a hydrophobicity test on the sample piece to determine the static contact angle θ _t of the sample piece;

   Determine whether the static contact angle θ _t is lower than a preset angle;

   If the static contact angle θ _t is lower than the preset angle, it is determined that the life of the sample is terminated;

   If the static contact angle θ _t is not lower than the preset angle, determine the hydrophobicity score C ₁ of the sample based on the static contact angle θ _t and the preset standard static contact angle θ _s ;

   Fourier transform infrared spectrum testing was performed on the sample to determine the heights of the four absorption peaks of Si-O-Si, Si(CH ₃ ) ₂ , Si-CH ₃ and CH ₃ (CH) in the infrared spectrum, which were recorded as H _Si respectively. _-O-Si , H _Si(CH3)2 , H _Si-CH3 and H _CH3(CH) ;

   Determine whether the height of any one of the four absorption peaks is less than its corresponding preset height, and each absorption peak corresponds to a preset height;

   If the height of any one of the four absorption peaks is less than its corresponding preset height, it is determined that the life of the sample is terminated;

   If the height of any one of the four absorption peaks is not less than its corresponding preset height, then the characteristic absorption peak height H t of the sample is determined based on the heights of the four absorption peaks, and the characteristic absorption peak height H _t of the sample is determined based on the preset height. The standard characteristic absorption peak height H _s determines the chemical bond score C ₂ of the sample;

   According to the hydrophobicity score C ₁ and the chemical bond score C ₂ , determine the total ultraviolet radiation resistance score C of the sample;

   The aging degree of the sample is determined based on the total UV radiation resistance score of the sample.
2. The method for identifying the ultraviolet radiation aging resistance of a coating on an insulator according to claim 1, characterized in that the method further includes: cleaning the sample piece with absolute ethanol before the hydrophobicity test.
3. The method for identifying the UV radiation aging resistance of a coating on an insulator according to claim 1, characterized in that said performing a hydrophobicity test on the sample piece and determining the static contact angle of the sample piece includes:

   Measure the sample pieces after the hydrophobicity test for a preset number of times;

   Average the measurement results of the preset number of times;

   The mean value was determined as the static contact angle of the coupon.
4. The method for identifying the UV radiation aging resistance of a coating on an insulator according to claim 1, wherein the preset angle is 80 degrees.
5. The method for identifying the UV radiation aging resistance of a coating on an insulator according to claim 1, wherein the preset height corresponding to the absorption peak is 10% of the corresponding preset standard absorption peak height.
6. The method for identifying the UV radiation aging resistance of a coating on an insulator according to claim 1, characterized in that the method for determining the characteristic absorption peak height H _t of the sample is:

   
7. The method for identifying the UV radiation aging resistance of a coating on an insulator according to claim 1, characterized in that the method for determining the chemical bond score _C2 of the sample is:

   
8. The method for identifying the UV radiation aging resistance of a coating on an insulator according to claim 1, characterized in that the UV radiation resistance total score C of the sample is the hydrophobicity score C ₁ and the chemical bond score Weighted average of C ₂ .
9. The method for identifying the UV radiation resistance aging degree of the coating on the insulator according to claim 8, characterized in that the determination method of the UV radiation resistance total score C of the sample is C=0.5C ₁ +0.5C ₂ .
10. The method for identifying the aging degree of ultraviolet radiation resistance of a coating on an insulator according to claim 1, wherein determining the aging degree of the sample piece based on the total ultraviolet radiation resistance score of the sample piece includes:

    Compare the total ultraviolet radiation resistance score with a preset score;

    If the total UV radiation resistance score is less than the preset score, it is determined that the life of the sample piece has been terminated;

    If the total UV radiation resistance score is not less than the preset score, the level of the UV radiation resistance total score will be used as the basis for identification of the UV radiation aging resistance of the sample.

Images