Method for detecting reaction degree of resin in coating and application of method

Abstract

The invention belongs to the technical field of coating curing, and particularly relates to a method for detecting the reaction degree of resin in a coating and application of the method. The detection method comprises the following steps: stripping a coating from the surface of a substrate to obtain coating fragments; the coating fragments with the mass of m1 are taken and placed in a ball milling device to be subjected to ball milling, and coating powder is obtained; dissolving the coating powder to obtain a mixed solution; carrying out solid-liquid separation on the mixed solution; sequentially cleaning and drying the obtained solid to obtain dried powder; the mass m2 of the dried powder is weighed, the mass m3 of pure resin is calculated according to m1 and the percentage content of the resin in the coating formula, the mass percentage w of the unreacted resin in the total resin in the coating is calculated based on m1, m2 and m3, and the reaction degree of the resin in the coating can reflect the curing degree of the coating. By adopting the detection method provided by the invention, a measurement basis can be provided for the total drying time or the residual drying time of the coating, and the production efficiency of the product is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coating curing, and in particular relates to a method for detecting the degree of resin reaction in a coating and an application thereof. Background Art

[0002] In the coating preparation process, fillers and resins need to be prepared into a filler mixture, and then the filler mixture is sprayed onto the surface of the substrate to finally form a coating on the surface of the substrate.

[0003] The coating needs to go through surface drying and thorough drying during the final forming process. Usually, a long extra time is spent in the surface drying and thorough drying stages to ensure that the coating is dry. At present, one method is to extend the coating drying time as much as possible based on experience to ensure that the coating is completely dry. However, this operation takes a long extra time, greatly prolongs the production cycle of the product, and affects production efficiency. Another method is to use the filter paper method or the cotton ball method to test the actual drying time of the coating. Both the filter paper method and the cotton ball method rely on the experience of the operator and have a large subjective influence. Different operators may have different judgment standards, or the same operator may have different conclusions in different experiments on the same sample, resulting in incomplete drying of the coating, thereby affecting product quality. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for detecting the degree of resin reaction in a coating and its application. The detection method proposed in the present invention can theoretically determine the drying time of the coating, which is beneficial to controlling the drying time and production cycle of the product.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for detecting the degree of resin reaction in a coating, comprising the following steps:

[0007] S1, peeling the coating from the substrate surface to obtain coating fragments;

[0008] S2, taking the coating fragments with a mass of m1 and placing them in a ball milling device for ball milling to obtain coating powder;

[0009] S3, taking out the coating powder in S2, and dissolving it in a first organic solvent to obtain a first mixed solution;

[0010] flushing the ball mill with a second organic solvent, collecting the flushing liquid to obtain a second mixed liquid;

[0011] S4, performing solid-liquid separation on the first mixed liquid to obtain a first solid to be processed; performing solid-liquid separation on the second mixed liquid to obtain a second solid to be processed;

[0012] S5, placing the first solid to be treated on a standard filter paper, and washing the first solid to be treated with a first organic solvent to obtain a third solid to be treated;

[0013] S6, mixing the second solid to be processed and the third solid to be processed and drying them to obtain a dried powder;

[0014] S7. Weigh the mass m2 of the dried powder in S6, calculate the mass m3 of the pure resin based on m1 and the percentage of resin in the coating formula, and calculate the mass percentage w of the unreacted resin in the total resin in the coating based on m1, m2 and m3.

[0015] Specifically, in S2, 1g≤m1≤2g, the ball milling device is a planetary ball mill, the ball milling beads used are 3mm-8mm zirconium beads, and the ball milling time is 10h-12h.

[0016] Specifically, deionized water was added during the ball milling process.

[0017] Specifically, the mass of the first organic solvent in the first mixed liquid and the mass of the second organic solvent in the second mixed liquid are both more than 30 times that of m1, and the dissolution time of the coating powder in the first mixed liquid and the dissolution time of the coating powder in the second mixed liquid are both 48h to 72h.

[0018] Specifically, during the dissolution process of the coating powder in the first mixed liquid, the first mixed liquid is stirred at a stirring rate of 100 r / min to 300 r / min.

[0019] Specifically, in S6, the mixture of the second solid to be treated and the third solid to be treated is dried at 110° C. to 150° C., and the drying time is 100 min to 120 min.

[0020] Specifically, the first organic solvent is one of anhydrous ethanol, methylbenzene or propanol; the second organic solvent is one of anhydrous ethanol, methylbenzene or propanol.

[0021] The present invention also provides an application of a method for detecting the degree of resin reaction in a coating, wherein the method is used to measure the total drying time of the coating or the remaining drying time of the coating.

[0022] Specifically, it includes:

[0023] After the sprayed coating on the substrate is dried for 4 to 6 hours, the reaction degree of the resin in the coating on the surface of the substrate is detected every 0.5 to 1.5 hours, and the sampling time and its corresponding test results are recorded until three consecutive test results meet the requirement that the maximum deviation is less than 10%.

[0024] The testing principle of the present invention is:

[0025] During the dissolution of the coating powder, the resin that has undergone a cross-linking reaction is insoluble in the organic solvent, while the unreacted resin is soluble in the organic solvent.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The detection method proposed in the present invention can detect the content of unreacted resin in the coating, and the reaction degree of the resin in the coating can reflect the curing degree of the coating. Therefore, the present invention provides a measurement basis for the total drying time of the coating or the remaining drying time of the coating. The total drying time of the coating or the remaining drying time of the coating can be determined according to the drying time and the corresponding resin reaction degree. Under the premise of ensuring that the coating is completely dried, the production cycle of the product is shortened and the production efficiency of the final product is improved.

[0028] (2) The detection method proposed in the present invention ball-mills the coating during the detection process, which can increase the surface area of ​​the coating particles, increase the contact area between the coating particles and the organic solvent, and make the unreacted resin dissolve more completely in the organic solvent, so that the detection result is more stable and accurate. The present invention also adds deionized water during the ball milling process, on the one hand to dissipate heat, and on the other hand to convert the ball milling medium into a fluid, which is more conducive to ball milling. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of the detection method of the present invention; DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] This example proposes a method for detecting the degree of resin reaction in a coating, comprising the following steps:

[0033] S1. Select a coating that is being dried in the same batch, peel the coating off the substrate surface, and obtain coating fragments;

[0034] S2. Place the coating fragments with a mass of m1 [1.0041 g] in a planetary ball mill for ball milling to obtain coating powder; deionized water needs to be added during the ball milling process, on the one hand to dissipate heat, and on the other hand to turn the ball milling medium into a fluid, which is more conducive to grinding;

[0035] S3, discharging the coating powder in the ball mill from the discharge port of the ball mill, placing it in a first organic solvent, and stirring for 48 hours to obtain a first mixed solution; in this embodiment, the mass of the first organic solvent in the first mixed solution is 102ml;

[0036] In order to test the accuracy of the results, the ball mill was rinsed with a second organic solvent, and the rinse liquid was collected and stirred for 60 hours to obtain a second mixed liquid;

[0037] S4, performing solid-liquid separation on the first mixed liquid to obtain a first solid to be processed; performing solid-liquid separation on the second mixed liquid to obtain a second solid to be processed;

[0038] S5, placing the first solid to be treated on a standard filter paper, and washing the first solid to be treated with a first organic solvent to obtain a third solid to be treated;

[0039] S6, mixing the second solid to be processed and the third solid to be processed, and drying the mixture at 150° C. for 100 min to obtain a dried powder;

[0040] S7. Weigh the mass m2 [0.5093 g] of the dried powder in S6, calculate the mass m3 of the pure resin based on m1 and the percentage of resin in the coating formula, and calculate the mass percentage w of the unreacted resin in the total resin in the coating based on m1, m2 and m3.

[0041] The percentage of resin in the coating formula of this embodiment is 75, so the calculation method of m3 is: m3 = m1 × 75% = 1.0041 × 75% = 0.7531g;

[0042] The calculation method of w is:

[0043] w=(m1-m2) / m3×100%=(1.0041-0.5093) / 0.7531×100%=65.70%.

[0044] Example 2

[0045] This example proposes a method for detecting the degree of resin reaction in a coating, comprising the following steps:

[0046] S1. Select a coating that is being dried in the same batch, peel the coating off the substrate surface, and obtain coating fragments;

[0047] S2. Place the coating fragments with a mass of m1 [1.5478 g] in a planetary ball mill for ball milling to obtain coating powder; deionized water needs to be added during the ball milling process, on the one hand to dissipate heat, and on the other hand to turn the ball milling medium into a fluid, which is more conducive to grinding;

[0048] S3, discharging the coating powder in the ball mill from the discharge port of the ball mill, placing it in a first organic solvent, and stirring for 60 hours to obtain a first mixed solution; in this embodiment, the mass of the first organic solvent in the first mixed solution is 30ml;

[0049] In order to test the accuracy of the results, the ball mill was rinsed with a second organic solvent, and the rinse liquid was collected and stirred for 72 hours to obtain a second mixed liquid; the mass of the second organic solvent in the second mixed liquid was 100 ml;

[0050] S4, performing solid-liquid separation on the first mixed liquid to obtain a first solid to be processed; performing solid-liquid separation on the second mixed liquid to obtain a second solid to be processed;

[0051] S5, placing the first solid to be treated on a standard filter paper, and washing the first solid to be treated with a first organic solvent to obtain a third solid to be treated;

[0052] S6, mixing the second solid to be processed and the third solid to be processed, and drying the mixture at 110° C. for 120 min to obtain a dried powder;

[0053] S7. Weigh the mass m2 [0.9934 g] of the dried powder in S6, calculate the mass m3 of the pure resin based on m1 and the percentage of resin in the coating formula, and calculate the mass percentage w of the unreacted resin in the total resin in the coating based on m1, m2 and m3.

[0054] The percentage of resin in the coating formula of this embodiment is 70, so the calculation method of m3 is: m3 = m1 × 70% = 1.5478 × 70% = 1.0835g;

[0055] The calculation method of w is:

[0056] w=(m1-m2) / m3×100%=(1.5478-0.9934) / 1.0835×100%=51.17%.

[0057] Example 3

[0058] This example proposes a method for detecting the degree of resin reaction in a coating, comprising the following steps:

[0059] S1. Select a coating that is being dried in the same batch, peel the coating off the substrate surface, and obtain coating fragments;

[0060] S2. Place the coating fragments with a mass of m1 [1.9784 g] in a planetary ball mill for ball milling to obtain coating powder; deionized water needs to be added during the ball milling process, on the one hand to dissipate heat, and on the other hand to turn the ball milling medium into a fluid, which is more conducive to grinding;

[0061] S3, discharging the coating powder in the ball mill from the discharge port of the ball mill, placing it in a first organic solvent, and stirring for 72 hours to obtain a first mixed solution; in this embodiment, the mass of the first organic solvent in the first mixed solution is 200ml;

[0062] In order to test the accuracy of the results, the ball mill was rinsed with a second organic solvent, and the rinse liquid was collected and stirred for 70 hours to obtain a second mixed liquid; the mass of the second organic solvent in the second mixed liquid was 100 ml;

[0063] S4, performing solid-liquid separation on the first mixed liquid to obtain a first solid to be processed; performing solid-liquid separation on the second mixed liquid to obtain a second solid to be processed;

[0064] S5, placing the first solid to be treated on a standard filter paper, and washing the first solid to be treated with a first organic solvent to obtain a third solid to be treated;

[0065] S6, mixing the second solid to be processed and the third solid to be processed, and drying the mixture at 130° C. for 110 min to obtain a dried powder;

[0066] S7. Weigh the mass m2 [1.8230 g] of the dried powder in S6, calculate the mass m3 of the pure resin based on m1 and the percentage of resin in the coating formula, and calculate the mass percentage w of the unreacted resin in the total resin in the coating based on m1, m2 and m3.

[0067] The percentage of resin in the coating formula of this embodiment is 65, so the calculation method of m3 is: m3 = m1 × 65% = 1.2860g;

[0068] The calculation method of w is:

[0069] w=(m1-m2) / m3×100%=(1.9784-1.8230) / 1.2860×100%=12.08%.

[0070] In the above embodiments, the ball milling beads used are 3mm to 8mm zirconium beads, and the ball milling time is 10h to 12h;

[0071] During the dissolution process, the stirring rate of the first mixed solution and the second mixed solution is 100r / min-300r / min;

[0072] The first organic solvent is one of anhydrous ethanol, methylbenzene or propanol; the second organic solvent is one of anhydrous ethanol, methylbenzene or propanol.

[0073] In the above embodiments, in order to improve the test accuracy, the operator can perform more than three groups of parallel experiments at the same time for each test, and finally take the average value as the test result.

[0074] Example 4

[0075] This embodiment proposes an application of a method for detecting the degree of resin reaction in a coating, and the detection method is the detection method proposed in Example 1:

[0076] The same batch of sprayed coatings are placed in the same environment for drying, and the drying time is recorded. Starting from the drying time reaching t, a coating is taken out every 0.5h to 1.5h, and the coating is peeled off from the substrate surface to obtain coating fragments. The ratio of the mass of unreacted resin to the total resin mass in the coating fragments is detected according to any one of the detection methods in Examples 1 to 3, and the sampling time and the corresponding detection results are recorded until three consecutive detection results w meet: the maximum deviation is less than 10%, and the record table is saved. The drying time or remaining time of the coating can be measured according to the sampling time and the corresponding detection results, where t is 4h to 6h.

[0077] Exemplarily, this embodiment adopts the detection method of embodiment 1, t is taken as 5h, and the following table is a record table of the degree of resin reaction:

[0078]

[0079] If the test results of the last three times meet the requirements and the maximum deviation is less than 10%, it can be determined that the coating is completely dry when the drying time is (t+8)h. In subsequent production, the production personnel can control the total drying time of the coating of the same specification under the same environment to 13h. In the subsequent production process, if an unexpected situation occurs and it is necessary to judge the drying time of the coating, one coating can be taken out from the same batch of coatings, and the reaction degree of the resin in the coating can be detected by the detection method proposed in the present invention to measure how long the coating needs to dry. For example, if the measured result is between 39.46% and 15.83%, the remaining drying time is (t+8)-(t+4.5)=3.5h.

[0080] In this embodiment, the interval time between two tests can be determined according to actual needs.

[0081] The specific embodiments of the present invention enable those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0082] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for detecting the degree of resin reaction in a coating, characterized in that: The following steps are involved: S1, peeling the coating from the substrate surface to obtain coating fragments; S2, taking the coating fragments with a mass of m1 and placing them in a ball milling device for ball milling to obtain coating powder; S3, taking out the coating powder in S2, and dissolving it in a first organic solvent to obtain a first mixed solution; flushing the ball mill with a second organic solvent, collecting the flushing liquid to obtain a second mixed liquid; S4, performing solid-liquid separation on the first mixed liquid to obtain a first solid to be processed; Performing solid-liquid separation on the second mixed liquid to obtain a second solid to be treated; S5, placing the first solid to be treated on a standard filter paper, and washing the first solid to be treated with a first organic solvent to obtain a third solid to be treated; S6, mixing the second solid to be processed and the third solid to be processed and drying them to obtain a dried powder; S7. Weigh the mass m2 of the dried powder in S6, calculate the mass m3 of the pure resin based on m1 and the percentage of resin in the coating formula, and calculate the mass percentage w of the unreacted resin in the total resin in the coating based on m1, m2 and m3.

2. The method for detecting the degree of resin reaction in a coating according to claim 1, characterized in that: In S2, 1g≤m1≤2g, the ball milling device is a planetary ball mill, the ball milling beads used are 3mm-8mm zirconium beads, and the ball milling time is 10h-12h.

3. The method for detecting the degree of resin reaction in a coating according to claim 2, characterized in that: Deionized water was added during the ball milling process.

4. The method for detecting the degree of resin reaction in a coating according to claim 1, characterized in that: The mass of the first organic solvent in the first mixed liquid and the mass of the second organic solvent in the second mixed liquid are both more than 30 times that of m1, and the dissolution time of the coating powder in the first mixed liquid and the dissolution time of the coating powder in the second mixed liquid are both 48h to 72h.

5. The method for detecting the degree of resin reaction in a coating according to claim 4, characterized in that: During the dissolution of the coating powder in the first mixed liquid, the first mixed liquid is stirred at a stirring rate of 100 r / min to 300 r / min.

6. The method for detecting the degree of resin reaction in a coating according to claim 1, characterized in that: In S6, the mixture of the second solid to be treated and the third solid to be treated is dried at 110° C. to 150° C., and the drying time is 100 min to 120 min.

7. The method for detecting the degree of resin reaction in a coating according to claim 1, characterized in that: The first organic solvent is one of anhydrous ethanol, methylbenzene or propanol; the second organic solvent is one of anhydrous ethanol, methylbenzene or propanol.

8. An application of the method for detecting the degree of resin reaction in a coating according to any one of claims 1 to 7, characterized in that: The test method is used to measure the total drying time of a coating or the remaining drying time of a coating.

9. Application of the method for detecting the degree of resin reaction in a coating according to claim 8, characterized in that: include: After the sprayed coating on the substrate is dried for 4 to 6 hours, the reaction degree of the resin in the coating on the surface of the substrate is detected every 0.5 to 1.5 hours, and the sampling time and its corresponding test results are recorded until three consecutive test results meet the requirement that the maximum deviation is less than 10%.

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