Method for rapidly testing discoloration of copper ion wall coating

Abstract

According to the rapid testing method for the discoloration of the copper ion wall coating, the defects that in an existing discoloration test, the discoloration test period of the copper ion wall coating is long, and the discoloration is slow can be overcome, the discoloration of copper ions can be more obvious by arranging different test matrix partitions on a gypsum board and combining new special test putty, and the discoloration of the copper ions can be more uniform. Meanwhile, the oven heating drying is added, the reaction speed can be increased, and the test period is shortened. In addition, the equal transverse division parts are added in the optimization scheme, so that the color change condition of the copper ion wall coating on different base materials can be tested synchronously.

Description

Technical Field

[0001] This invention relates to the field of coating testing technology, specifically to a rapid testing method for color change in copper ion wall coatings. Background Technology

[0002] People are increasingly valuing the antiviral and antibacterial properties of paints, leading more and more consumers to choose paints with these functions. Among the many antibacterial paints, copper ion antiviral and antibacterial paints are favored by some users due to their relatively low price. However, the cuprous ions in copper ion antiviral and antibacterial paints are unstable and easily oxidize into divalent copper ions, causing varying degrees of discoloration and affecting the user experience.

[0003] Currently, this testing field only uses colorimeters to test paint color changes; however, the relevant testing methods for copper ion wall paint color changes are similar to those for testing paint color changes using colorimeters.

[0004] Conventional copper ion wall paints change color slowly after application. The usual method to accelerate this process is to increase the temperature to speed up the oxidation reaction of divalent copper ions in the paint. However, simply increasing the temperature does not produce a noticeable color change, and it usually takes about a week to see a significant color difference.

[0005] A common problem with copper ion wall coatings is inconsistent color change on different substrates. For example, copper ion wall coatings applied simultaneously to walls and plaster may develop color differences over time, severely affecting aesthetics and even leading to customer complaints. This phenomenon is due to the different oxidation rates of copper ions on different substrates.

[0006] Currently, there are no technical standards or corresponding testing standards in the coatings industry for addressing the color change of copper ion wall coatings on different substrates. Summary of the Invention

[0007] The technical problem this invention aims to solve is to provide a rapid testing method for the color change of copper ion wall coatings. This method overcomes the shortcomings of existing color change tests, which suffer from long testing cycles and slow color change. By setting different test matrix zones on a gypsum board and combining this with a new specialized test putty, the color change of copper ions can be made more obvious. Furthermore, the addition of an oven for heating and drying accelerates the reaction speed and shortens the testing cycle. In addition, the equally divided horizontal sections added to the optimized scheme allow for simultaneous testing of the color change of copper ion wall coatings on different substrates.

[0008] To solve the above problems, the present invention is achieved through the following technical solution:

[0009] The first objective of this invention is:

[0010] A rapid test method for detecting discoloration of copper ion wall coatings is provided, which includes the following steps;

[0011] S1. Sample preparation: Clean the surface of the gypsum board, ensuring it is clean and dry, and set aside for later use;

[0012] S2. Preparation of different test base areas:

[0013] Divide the plasterboard prepared in step S1 into three equal parts horizontally: upper, middle, and lower, using washi tape.

[0014] S3. Test the base coat application:

[0015] Under the conditions of 23℃±2℃ and 50%±5% relative humidity, in step S2, two sections of the gypsum board were coated with 2-in-1 putty and test-specific putty, respectively, leaving one section as a blank control. After one coat was applied and dried for 24 hours, a second coat was applied. The thickness of the test substrate after two coats should not exceed 1 mm. After the coating was completed, the substrate was cured and dried in a constant temperature and humidity chamber for 24 hours. Then, the Lab values ​​of the blank control on the gypsum board and different test substrates were tested and recorded.

[0016] The test-specific putty comprises the following components in parts by weight:

[0017] Talc powder 240-300 parts, cooked glue powder 10-15 parts, glue 20-40 parts, water 80-110 parts;

[0018] The 2-in-1 putty paste mentioned is Nippon Paint's Pilebao 2-in-1 putty paste;

[0019] S4. Preparation of copper ion wall coating layer:

[0020] After applying the test putty in step S3, the plasterboard is divided longitudinally into two parts, left and right, using washi tape.

[0021] S5. Copper ion wall paint layer application:

[0022] Under the conditions of temperature 23℃±2℃ and relative humidity 50%±5%, use a 3-inch wool brush to evenly apply 25g of copper ion wall paint to one of the two sections on the left and right; after drying for 1 hour, apply the second coat using the same method; after drying for 1 hour, wait for the paint film to be basically surface dry.

[0023] After step S5, the entire plasterboard is actually divided into 6 different test substrate areas:

[0024] S6. Continue drying in a 40℃ forced-air drying oven for 2 hours, and test and record the Lab values ​​of 6 different test substrate areas on the gypsum board.

[0025] S7. Evaluation of discoloration results of copper ion wall coatings:

[0026] Using the ΔE color difference value as the evaluation criterion, the calculation formula is as follows:

[0027] △E color difference value:

[0028]

[0029] in:

[0030] ΔE1 is the ΔE color difference value between the 2-in-1 putty paste and the copper ion paint on the test-specific putty after drying for 2 hours;

[0031] △L1=︱L1-L0︱, △a1=︱a1-a0︱, △b1=︱b1-b0︱;

[0032] ΔE2 is the ΔE color difference value between the 2-in-1 putty paste and the copper ion paint on the gypsum board after drying for 2 hours;

[0033] △L2=︱L2-L0︱, △a2=︱a2-a0︱, △b2=︱b2-b0︱;

[0034] L0 is the L value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6.

[0035] L1 is the L value of the copper ion wall paint area on the test putty after drying for 2 hours in step S6;

[0036] L2 is the L value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6.

[0037] a0 is the a value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6;

[0038] a1 is the a value of the copper ion wall paint area on the test putty after drying for 2 hours in step S6;

[0039] a2 is the a value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6;

[0040] b0 is the b value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6;

[0041] b1 is the b value of the copper ion wall paint area on the special putty after drying for 2 hours in step S6;

[0042] b2 is the b value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6;

[0043] When ΔE1 or ΔE2 ≤ 0.5, the copper ion wall coating is considered to have virtually no color difference on the corresponding test substrate, the grade is 0, and the evaluation result is qualified.

[0044] When 0.5 < (ΔE1 or ΔE2) ≤ 1, the copper ion wall coating is considered to have a slight color difference on the corresponding test substrate, the grade is 1, and the evaluation result is qualified;

[0045] When ΔE1 or ΔE2 > 1, the copper ion wall coating is considered to have a significant color difference on the corresponding test substrate, with a grade of 2 and an evaluation result of unqualified.

[0046] The rapid test method for color change of copper ion wall coatings of the present invention is further optimized as follows:

[0047] It also includes the following steps;

[0048] S8. Precise assessment of color change results for copper ion wall coatings:

[0049] Similarly, the ΔE color difference value is used as the evaluation criterion:

[0050] When ΔE3, ΔE4, and ΔE5 are all ≤0.5, it is determined that the substrate discoloration has no effect on the discoloration of the copper ion wall coating.

[0051] When any of the ΔE color difference values ​​among ΔE3, ΔE4, and ΔE5 is greater than 0.5, it is determined that the corresponding substrate also changed color during the drying process, which affects the experimental results.

[0052] in:

[0053] ΔE3 is the color difference value of ΔE after drying the blank control position on the gypsum board for 48 hours in step S3 and after drying for 2 hours in step S6.

[0054] ΔE4 is the color difference value of ΔE after the location of the 2-in-1 putty paste on the gypsum board in step S3 has been dried for 48 hours and after drying for 2 hours in step S6.

[0055] ΔE5 is the color difference value of ΔE after the location of the test putty on the gypsum board in step S3 has been dried for 48 hours and after drying for 2 hours in step S6.

[0056] The rapid test method for color change of copper ion wall coatings of the present invention is further optimized as follows:

[0057] The test-specific putty includes the following preparation steps:

[0058] Weigh out the appropriate amount of water according to the formula, add cooked rubber powder during mechanical stirring, stir evenly, and let stand for half an hour to allow the cooked rubber powder to fully mature and obtain a mixture.

[0059] Then add glue to the mixture and stir at 1000 rpm for 5 minutes to make it evenly mixed; appropriately increase the stirring speed to 1200 rpm to 1500 rpm, and add the weighed talc powder in several batches while stirring. After all the talc powder is added, stir for 30 minutes to prepare the special putty for copper ion compatibility testing.

[0060] The rapid test method for color change of copper ion wall coatings of the present invention is further optimized as follows:

[0061] In step S2, washi tape is used to divide the plasterboard horizontally into three equal parts: upper, middle, and lower, with each part being 15cm high.

[0062] The rapid test method for color change of copper ion wall coatings of the present invention is further optimized as follows:

[0063] In step S4, washi tape is used to divide the plasterboard longitudinally into two equal parts, left and right, each part being 20cm wide.

[0064] The rapid test method for color change of copper ion wall coatings of the present invention is further optimized as follows:

[0065] In step S2, washi tape is used to divide the plasterboard into equal horizontal sections. In addition to the three sections mentioned above, there are more equal sections for applying other test substrates. Each section is 15cm high.

[0066] The rapid test method for color change of copper ion wall coatings of the present invention is further optimized as follows:

[0067] The rapid test method for color change of copper ion wall coatings requires at least three parallel tests for each test, and the average value should be taken.

[0068] Compared with ordinary ready-made putty, the special test putty used in this invention, after drying, allows for two coats of copper ion wall paint to be applied to the surface. The copper ion wall paint changes color faster and shows more obvious color on the special test putty, making it easier to achieve the test effect and purpose of the copper ion wall paint compatibility test.

[0069] The rapid test method for color change of copper ion wall coatings of the present invention has the following technical features:

[0070] 1. To address the issue of varying color change rates of copper ion wall coatings on different substrates, a method was developed to create panels on gypsum board. This method utilizes gypsum board, 2-in-1 putty paste, and a special test putty to more closely resemble actual home decoration practices. Furthermore, the panel-making process is simple and easy to operate.

[0071] 2. The putty layer thickness is specified to be no more than 1mm to avoid the putty layer being too thick and affecting the test results of copper ion wall coating.

[0072] 3. Apply two coats of copper ion wall paint using a 3-inch wool brush, 25g per coat, to simulate the actual paint film thickness. This process is simplified to avoid discrepancies in dosage during parallel tests.

[0073] 4.40℃ drying of the paint film is a rapid drying process that minimizes damage to the paint film, accelerates the oxidation and discoloration of the copper ion wall coating, and achieves the purpose of rapid detection.

[0074] 5. The Lab value of copper ion wall paint on 2-in-1 putty is used as the standard to compare the color change on other test substrates because the copper ion wall paint on 2-in-1 putty changes color the slowest, while the color change on other test substrates is faster. In addition, 2-in-1 putty is more common in actual home decoration and can better reflect the actual application situation. Attached Figure Description

[0075] Figure 1 This is a three-dimensional schematic diagram of the testing system involved in Embodiment 1 of the present invention.

[0076] Figure 2 for Figure 1 Schematic diagram of the structure of different test base layers.

[0077] Figure 3 for Figure 1 A schematic diagram of the structure of the copper ion wall coating layer.

[0078] Explanation of reference numerals in the attached diagram:

[0079] 1-Gypsum board, 2-Different test substrates, 3-Copper ion wall coating layer. Detailed Implementation

[0080] To make the application, technical solution, and advantages of this invention clearer, the invention is described in detail with reference to specific embodiments. It should be understood that the embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Any simple improvements to the preparation method of this invention based on the inventive concept fall within the scope of protection of this invention.

[0081] Example 1

[0082] A rapid test method for color change of copper ion wall coatings includes the following steps;

[0083] S1. Sample preparation: Cut the plasterboard into fixed sizes of 40cm×60cm, clean the surface, and ensure that the surface is clean and dry, and set aside;

[0084] S2. Preparation of different test base areas:

[0085] Use washi tape to divide the plasterboard prepared in step S1 into four equal parts along its 60cm length. Each part should be 15cm high (see details). Figure 2 );

[0086] S3. Test the base coat application:

[0087] Under the conditions of 23℃±2℃ and 50%±5% relative humidity, in step S2, 2-in-1 putty, test-specific putty, and joint compound were applied to three sections of the gypsum board, respectively, leaving one section as a blank control. After one coat was applied and dried for 24 hours, a second coat was applied. The thickness of the test substrate after two coats should not exceed 1 mm. After the coating was completed, the substrate was cured and dried in a constant temperature and humidity chamber for 24 hours. Then, the Lab values ​​of the blank control and different test substrates on the gypsum board were tested and recorded.

[0088] The test-specific putty comprises the following components in parts by weight:

[0089] 280 parts talcum powder, 12 parts cooked glue powder, 20 parts glue, 100 parts water;

[0090] The 2-in-1 putty paste mentioned is Nippon Paint's Pilebao 2-in-1 putty paste;

[0091] S4. Preparation of copper ion wall coating layer:

[0092] After applying the test putty in step S3, use washi tape to divide the plasterboard longitudinally into two parts, left and right, each 20cm wide (see details). Figure 2 );

[0093] S5. Copper ion wall paint layer application:

[0094] Under the conditions of temperature 23℃±2℃ and relative humidity 50%±5%, use a 3-inch wool brush to evenly apply 25g of copper ion wall paint to one of the two sections on the left and right; after drying for 1 hour, apply the second coat using the same method; after drying for 1 hour, wait for the paint film to be basically surface dry.

[0095] After step S5, the entire plasterboard is actually divided into 8 different test substrate areas:

[0096] S6. Continue drying in a 40℃ forced-air drying oven for 2 hours, and test and record the Lab values ​​of 8 different test substrate areas on the gypsum board.

[0097] S7. Evaluation of discoloration results of copper ion wall coatings:

[0098] Using the ΔE color difference value as the evaluation criterion, the calculation formula is as follows:

[0099] △E color difference value:

[0100]

[0101] in:

[0102] ΔE1 is the ΔE color difference value between the 2-in-1 putty paste and the copper ion paint on the test-specific putty after drying for 2 hours;

[0103] △L1=︱L1-L0︱, △a1=︱a1-a0︱, △b1=︱b1-b0︱;

[0104] ΔE2 is the ΔE color difference value between the 2-in-1 putty paste and the copper ion paint on the gypsum board after drying for 2 hours;

[0105] △L2=︱L2-L0︱, △a2=︱a2-a0︱, △b2=︱b2-b0︱;

[0106] ΔE q The ΔE color difference value is the result of drying copper ion paint on the 2-in-1 putty and caulking compound for 2 hours.

[0107] △L q =|L q -L0︱,△a q =|a q -a0︱,△b q =|b q -b0︱;

[0108] L0 is the L value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6.

[0109] L1 is the L value of the copper ion wall paint area on the test putty after drying for 2 hours in step S6;

[0110] L2 is the L value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6.

[0111] L q The L value of the copper ion wall coating area on the caulking compound after drying for 2 hours in step S6;

[0112] a0 is the a value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6;

[0113] a1 is the a value of the copper ion wall paint area on the test putty after drying for 2 hours in step S6;

[0114] a2 is the a value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6;

[0115] a q The a value of the copper ion wall paint area on the caulking compound after drying for 2 hours in step S6;

[0116] b0 is the b value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6;

[0117] b1 is the b value of the copper ion wall paint area on the special putty after drying for 2 hours in step S6;

[0118] b2 is the b value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6;

[0119] b q The b value of the copper ion wall paint area on the caulking compound after drying for 2 hours in step S6;

[0120] When ΔE1 or ΔE2 or ΔE q When the value is ≤0.5, the copper ion wall coating is considered to have basically no color difference on the corresponding test substrate, the grade is 0, and the evaluation result is qualified;

[0121] When 0.5 < (ΔE1 or ΔE2 or ΔE) q When the value is less than or equal to 1, the copper ion wall coating is considered to have a slight color difference on the corresponding test substrate, the grade is 1, and the evaluation result is qualified.

[0122] When ΔE1 or ΔE2 or ΔE q If the value is greater than 1, the copper ion wall coating is considered to have a significant color difference on the corresponding test substrate, the grade is 2, and the evaluation result is unqualified.

[0123] S8. Precise assessment of color change results for copper ion wall coatings:

[0124] Similarly, the ΔE color difference value is used as the evaluation criterion:

[0125] When ΔE3, ΔE4, ΔE5, ΔE Q When all values ​​are ≤0.5, the assessment is that the discoloration of the substrate has no effect on the discoloration of the copper ion wall coating;

[0126] When ΔE3, ΔE4, ΔE5, ΔE Q When a certain ΔE color difference value is greater than 0.5, it is determined that the corresponding substrate also changed color during the drying process, which affects the experimental results.

[0127] in:

[0128] ΔE3 is the color difference value of ΔE after drying the blank control position on the gypsum board for 48 hours in step S3 and after drying for 2 hours in step S6.

[0129] ΔE4 is the color difference value of ΔE after the location of the 2-in-1 putty paste on the gypsum board in step S3 has been dried for 48 hours and after drying for 2 hours in step S6.

[0130] ΔE5 is the color difference value of ΔE after the location of the test putty on the gypsum board in step S3 has been dried for 48 hours and after drying for 2 hours in step S6.

[0131] ΔE Q The color difference ΔE is the difference between the location of the caulking compound on the gypsum board in step S3 after drying for 48 hours and the location after drying for 2 hours in step S6.

[0132] The test-specific putty includes the following preparation steps:

[0133] Weigh out the appropriate amount of water according to the formula, add cooked rubber powder during mechanical stirring, stir evenly, and let stand for half an hour to allow the cooked rubber powder to fully mature and obtain a mixture.

[0134] Then add glue to the mixture and stir at 1000 rpm for 5 minutes to make it evenly mixed; appropriately increase the stirring speed to 1200 rpm to 1500 rpm, and add the weighed talc powder in several batches while stirring. After all the talc powder is added, stir for 30 minutes to prepare the special putty for copper ion compatibility testing.

[0135] The rapid test method for color change of copper ion wall coatings requires at least three parallel tests for each test, and the average value should be taken.

[0136] The test system involved in the rapid test method for color change of copper ion wall coating in this embodiment 1 is detailed in [link to example]. Figure 1 It mainly includes gypsum board 1, different test base layers 2 and copper ion wall coating layer 3.

[0137] Table 1. Results of three tests in Example 1

[0138]

[0139]

[0140] Based on the three test records in Table 1:

[0141] ΔE3, ΔE4, ΔE5, ΔE Q All values ​​were ≤0.5, indicating that the discoloration of the substrate had no effect on the discoloration of the copper ion wall coating.

[0142] ΔE1>1 indicates that the copper ion wall paint has a significant color difference on the test putty, with a grade of 2 and an evaluation result of unqualified;

[0143] ΔE2≤0.5 indicates that the copper ion wall coating has virtually no color difference on the gypsum board, with a grade of 0 and an evaluation result of qualified.

[0144] ΔE Q>1 indicates that the copper ion wall paint has obvious color difference in the caulking compound, the grade is 2, and the evaluation result is unqualified;

[0145] Comparative Example 1

[0146] The rapid test method for the color change of copper ion wall coating in Comparative Example 1 is the same as that in Example 1. The main difference is that Example 1 uses a special test putty, while the composition of the self-mixed putty used in Comparative Example 1 is the same as that in Example 1. However, the weight of cooked glue powder in the putty in Comparative Example 1 is 5 parts, which is not within the limit range of the special test putty.

[0147] Comparative Example 2

[0148] The rapid test method for color change of copper ion wall coating in Comparative Example 2 is the same as that in Example 1. The main difference is that Comparative Example 2 uses the same weight of commercially available putty paste instead of the special test putty used in Example 1.

[0149] Table 2. Test results of the examples and comparative examples.

[0150]

[0151] A comparison was made between the special test putty, self-mixed putty, and commercially available ready-made putty paste. No color difference was observed in any of the three putties. Copper ion wall paint was then applied to the surfaces of the three putties, and the color difference ΔE of the copper ion wall paint was recorded within 30 days after application. The special test putty showed faster color change and more obvious test results.

[0152] In summary, the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any changes, modifications, and evolutions made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content shall be considered equivalent embodiments of the present invention. Furthermore, any changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention shall still fall within the protection scope of the present invention.

[0153] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0154] Experimental methods not specified in this invention are generally performed under conventional conditions or as recommended by the manufacturer.

[0155] Unless otherwise stated, the various optimized technical solutions in this invention can be combined with each other.

[0156] Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0157] Experimental methods not specified in the instructions and examples are generally performed under standard conditions or as recommended by the manufacturer.

[0158] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

Claims

1. A rapid test method for color change in copper ion wall coatings, characterized in that: It includes the following steps; S1. Sample preparation: Clean the surface of the gypsum board, ensuring it is clean and dry, and set aside for later use; S2. Preparation of different test base areas: Divide the plasterboard prepared in step S1 into three equal parts horizontally: upper, middle, and lower, using washi tape. S3. Test the base coat application: Under the conditions of 23℃±2℃ and 50%±5% relative humidity, in step S2, two sections of the gypsum board were coated with 2-in-1 putty and test-specific putty, respectively, leaving one section as a blank control. After one coat was applied and dried for 24 hours, a second coat was applied. The thickness of the test substrate after two coats should not exceed 1 mm. After the coating was completed, the substrate was cured and dried in a constant temperature and humidity chamber for 24 hours. Then, the Lab values ​​of the blank control on the gypsum board and different test substrates were tested and recorded. The test-specific putty comprises the following components in parts by weight: Talc powder 240-300 parts, cooked glue powder 10-15 parts, glue 20-40 parts, water 80-110 parts; The 2-in-1 putty paste mentioned is Nippon Paint's Pilebao 2-in-1 putty paste; S4. Preparation of copper ion wall coating layer: After applying the test putty in step S3, the plasterboard is divided longitudinally into two parts, left and right, using washi tape. S5. Copper ion wall paint layer application: Under the conditions of temperature 23℃±2℃ and relative humidity 50%±5%, use a 3-inch wool brush to evenly apply 25g of copper ion wall paint to one of the two sections on the left and right; after drying for 1 hour, apply the second coat using the same method; after drying for 1 hour, wait for the paint film to be basically surface dry. After step S5, the entire plasterboard is actually divided into 6 different test substrate areas: S6. Continue drying in a 40℃ forced-air drying oven for 2 hours, and test and record the Lab values ​​of 6 different test substrate areas on the gypsum board. S7. Evaluation of discoloration results of copper ion wall coatings: Using the ΔE color difference value as the evaluation criterion, the calculation formula is as follows: △E color difference value: in: ΔE1 is the ΔE color difference value between the 2-in-1 putty paste and the copper ion paint on the test-specific putty after drying for 2 hours; △L1=︱L1-L0︱, △a1=︱a1-a0︱, △b1=︱b1-b0︱; ΔE2 is the ΔE color difference value between the 2-in-1 putty paste and the copper ion paint on the gypsum board after drying for 2 hours; △L2=︱L2-L0︱, △a2=︱a2-a0︱, △b2=︱b2-b0︱; L0 is the L value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6. L1 is the L value of the copper ion wall paint area on the test putty after drying for 2 hours in step S6; L2 is the L value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6. a0 is the a value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6; a1 is the a value of the copper ion wall paint area on the test putty after drying for 2 hours in step S6; a2 is the a value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6; b0 is the b value of the copper ion wall paint area on the 2-in-1 putty after drying for 2 hours in step S6; b1 is the b value of the copper ion wall paint area on the special putty after drying for 2 hours in step S6; b2 is the b value of the copper ion wall coating area on the gypsum board after drying for 2 hours in step S6; When ΔE1 or ΔE2 ≤ 0.5, the copper ion wall coating is considered to have virtually no color difference on the corresponding test substrate, the grade is 0, and the evaluation result is qualified. When 0.5 < (ΔE1 or ΔE2) ≤ 1, the copper ion wall coating is considered to have a slight color difference on the corresponding test substrate, the grade is 1, and the evaluation result is qualified; When ΔE1 or ΔE2 > 1, the copper ion wall coating is considered to have a significant color difference on the corresponding test substrate, with a grade of 2 and an evaluation result of unqualified.

2. The rapid test method for color change of copper ion wall coatings according to claim 1, characterized in that: It also Includes the following steps; S8. Precise assessment of color change results for copper ion wall coatings: Similarly, the ΔE color difference value is used as the evaluation criterion: When ΔE3, ΔE4, and ΔE5 are all ≤0.5, it is determined that the substrate discoloration has no effect on the discoloration of the copper ion wall coating. When any of the ΔE color difference values ​​among ΔE3, ΔE4, and ΔE5 is greater than 0.5, it is determined that the corresponding substrate also changed color during the drying process, which affects the experimental results. in: ΔE3 is the color difference value of ΔE after drying the blank control position on the gypsum board for 48 hours in step S3 and after drying for 2 hours in step S6. ΔE4 is the color difference value of ΔE after the location of the 2-in-1 putty paste on the gypsum board in step S3 has been dried for 48 hours and after drying for 2 hours in step S6. ΔE5 is the color difference value of ΔE after the location of the test putty on the gypsum board in step S3 has been dried for 48 hours and after drying for 2 hours in step S6.

3. The rapid test method for color change of copper ion wall coatings according to claim 1, characterized in that: The test-specific putty includes the following preparation steps: Weigh out the appropriate amount of water according to the formula, add cooked rubber powder during mechanical stirring, stir evenly, and let stand for half an hour to allow the cooked rubber powder to fully mature and obtain a mixture. Then add glue to the mixture and stir at 1000 rpm for 5 minutes to make it evenly mixed; appropriately increase the stirring speed to 1200 rpm to 1500 rpm, and add the weighed talc powder in several batches while stirring. After all the talc powder is added, stir for 30 minutes to prepare the special putty for copper ion compatibility testing.

4. The rapid test method for color change of copper ion wall coatings according to claim 1, characterized in that: In step S2, washi tape is used to divide the plasterboard horizontally into three equal parts: upper, middle, and lower, each with a height of 15cm.

5. The rapid test method for color change of copper ion wall coatings according to claim 1, characterized in that: In step S4, washi tape is used to divide the plasterboard longitudinally into two equal parts, left and right, each part being 20cm wide.

6. The rapid test method for color change of copper ion wall coating according to claim 1, characterized in that: In step S2, washi tape is used to divide the plasterboard into equal horizontal sections. In addition to the three sections mentioned above, there are more equal sections for applying other test substrates. Each section is 15cm high.

7. The rapid test method for color change of copper ion wall coatings according to claim 1, characterized in that: The rapid test method for color change of copper ion wall coatings requires at least three parallel tests for each test, and the average value should be taken.

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