Coating degradation evaluation method and coating degradation evaluation device

Abstract

To provide a coating degradation evaluation method capable of predicting the service life of coatings in actual use with higher accuracy than conventional methods, and a coating degradation evaluation device.SOLUTION: A coating degradation evaluation method includes the steps of: non-destructively measuring parameters changing with degradation in a coating having the same composition as an inspection target material under plurality of conditions; constructing a coating degradation database from the parameters changing with degradation, the coating degradation time, and the degradation environment temperature, and constructing a degradation estimation formula from the degradation database; non-destructively measuring the parameters changing with degradation in the inspection target material whose degradation has progressed during actual use; inputting the parameters changing with degradation in the inspection target material into the degradation estimation formula to calculate the degradation environment of the inspection target material whose degradation has progressed during actual use; and calculating the time until the inspection target material whose degradation has progressed during actual use is determined to have degraded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for evaluating deterioration of a coating film formed on the surface of a steel member used in, for example, a high-temperature environment. [Background technology]

[0002] As an example of a simple method for evaluating the weather resistance of a coating film, Patent Document 1 describes a method for predicting deterioration of a coating film by measuring the amount of chemiluminescence of the coating film under conditions of continuous temperature increase in an oxygen or air atmosphere. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-98475 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, surfaces of objects have been painted for the purposes of protection, aesthetics, and properties. In particular, heavy-duty anticorrosion paints are used to protect steel structures used in harsh environments, and these paints are required to have excellent corrosion protection.

[0005] Such structures have large areas to be painted, and inspecting and repairing the paint film as it deteriorates over time requires enormous costs, so there is a need to develop appropriate operation and maintenance methods.

[0006] Numerous studies have been conducted to date to determine the standards for determining the frequency of inspections and repairs, and the durability of coating films has been predicted, for example, by evaluation through outdoor exposure tests (JIS K 5600-7-6: Long-term durability of coating films - outdoor exposure weather resistance) or by evaluation using a calibration curve created from the apparent activation energy related to the amount of chemiluminescence (see Patent Document 1 mentioned above).In addition, methods for evaluating the state of deterioration of coating films that have deteriorated over time include visual appearance inspection and image recognition of photographed images.

[0007] Of the above methods, the method for predicting the durability of a coating film has room for improvement, as it is unclear whether it is able to reproduce the actual usage environment and it is expected that there will be discrepancies between the predicted results and the actual results.

[0008] Furthermore, visual inspection of the appearance and evaluation by image recognition of photographed images aim to assess the degree of deterioration of the coating film based on defects that have already appeared on the coating film surface, and there is the problem that it is difficult to estimate the usable life of the coating film.

[0009] Therefore, an object of the present invention is to provide a coating deterioration evaluation method and coating deterioration evaluation device that can predict the usable life of a coating film that is actually in use with higher accuracy than conventional methods. [Means for solving the problem]

[0010] The present invention includes multiple means for solving the above-mentioned problems, and one example is a method for evaluating the deterioration state of a coating film, comprising the steps of: non-destructively measuring parameters that change with deterioration under multiple conditions for a coating film having the same configuration as a test object material; constructing a coating film deterioration database consisting of the parameters that change with deterioration, the coating film deterioration time, and the deterioration environment temperature, and constructing a deterioration estimation formula from the deterioration database; non-destructively measuring parameters that change with deterioration of the test object material that has deteriorated with actual use; inputting the parameters that change with the deterioration of the test object material into the deterioration estimation formula to calculate the deterioration environment of the test object material that has deteriorated with actual use; and calculating the time until the test object material that has deteriorated with actual use is determined to have deteriorated. [Effects of the Invention]

[0011] According to the present invention, the usable life of a coating film that is actually in use can be predicted with higher accuracy than in the past. Objects, configurations, and effects other than those described above will become clear from the following description of the examples. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a coating film deterioration evaluation device according to an embodiment. [Figure 2] A diagram showing the relationship between parameters that change with deterioration and LMP. [Figure 3] An illustration of the paint film temperature and the deterioration environment temperature. DETAILED DESCRIPTION OF THE INVENTION

[0013] Examples of the coating deterioration evaluation method and coating deterioration evaluation device of the present invention will be described with reference to Figures 1 to 3. In the drawings used in this specification, identical or corresponding components are designated by identical or similar reference numerals, and repeated explanations of these components may be omitted.

[0014] First, the overall configuration of the coating film deterioration evaluation device according to the embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing the schematic configuration of the coating film deterioration evaluation device according to the embodiment.

[0015] The coating deterioration evaluation device 20 shown in Figure 1 is a device for evaluating the deterioration state of a coating, and is equipped with a database unit 1 consisting of a deteriorated coating creation unit 11, a deteriorated coating measurement unit 12, a database construction unit 13, and a deterioration estimation formula creation unit 14, an evaluation target material measurement unit 2, an evaluation target material deterioration environment estimation unit 3, an evaluation target material usable period calculation unit 4, and a usable period display unit 5.

[0016] In the coating deterioration evaluation device 20 shown in FIG. 1, the deteriorated coating measurement unit 12 and the evaluation target material measurement unit 2 are composed of measurement devices.

[0017] The database construction unit 13, deterioration estimation formula creation unit 14, evaluation target material deterioration environment estimation unit 3, evaluation target material usable period calculation unit 4, and usable period display unit 5 can be realized by a PC (Personal Computer) equipped with hardware such as an arithmetic unit such as a CPU, a main memory unit such as a semiconductor memory and an auxiliary memory unit such as a hard disk, input devices such as a keyboard and a USB port, and an output device consisting of a monitor, and the control of the operation of each device and various calculation processes described below are performed based on various programs.

[0018] The programs may be stored in an internal storage unit, an external recording medium, a data server (all not shown), or the like, and may be read and executed by the CPU. The control processes may be integrated into a single program, or may be separated into multiple programs, or a combination thereof. Some or all of the programs may be implemented using dedicated hardware or may be modularized. Furthermore, the various programs may be installed from a program distribution server, an internal storage medium, or an external recording medium.

[0019] Details of each part are given below.

[0020] The "deteriorated coating film creation unit 11" is an execution process that accelerates the deterioration of a coating film with the same composition as the evaluation target material. Factors that cause deterioration of the evaluation target material, such as deterioration factors caused by external energy such as ultraviolet rays and heat, are assumed, and a deteriorated coating film is created by applying the load of deterioration factors.

[0021] Here, we have described an apparatus and method for evaluating the state of deterioration of a coating film due to heat, but the external energy that causes deterioration is not limited to heat; it is possible to evaluate the state of a coating film that deteriorates due to various factors, such as light including ultraviolet rays, liquids such as seawater, or multiple factors among these external factors.

[0022] The coating film to be evaluated is preferably a heavy-duty anticorrosive paint, such as an epoxy resin paint, a urethane resin paint, a silicone resin paint, or a fluororesin paint, but is not particularly limited.

[0023] The "deteriorated coating measurement unit 12" is a measuring device that non-destructively measures parameters that change with deterioration for a coating that has the same configuration as the material being inspected under multiple conditions. For example, this is a process in which the physical properties and chemical state of a deteriorated coating film prepared in the "deteriorated coating film preparation unit 11" is measured using a measuring device.

[0024] This deteriorated coating measurement unit 12 preferably performs the process of non-destructively measuring parameters that change with deterioration under a plurality of conditions for a coating having the same configuration as the material to be inspected.

[0025] The parameter items measured in the deteriorated coating measurement unit 12 that change with deterioration of the coating include parameters that change with deterioration, such as color information of the coating measured by a color difference meter and information on peak intensity in the FT-IR spectrum.

[0026] In particular, a portable measuring device is desirable for evaluation at the site where the coating film is used. The measuring method used in the present invention can be appropriately changed depending on the coating film to be measured and its application.

[0027] The "database construction unit 13" is configured to construct and record a database of data measured by the "deteriorated coating measurement unit 12." The database is constructed as a set of parameters for deterioration factors such as temperature and time when the deteriorated coating was produced, and parameters that change with deterioration. For example, a coating deterioration database can be constructed that consists of parameters that change with deterioration, the deterioration time of the coating, and the deterioration environment temperature.

[0028] The database construction unit 13 can utilize not only the data acquired through the "deteriorated coating film creation unit 11" and the "deteriorated coating film measurement unit 12," but also data acquired from public databases, papers, and samples deteriorated in real environments.

[0029] The "deterioration estimation formula creation unit 14" is a part that constructs a deterioration estimation formula from a deterioration database, and is a processing unit that applies linear regression analysis to the database constructed by the "database construction unit 13", for example, and creates a correlation model between parameters of deterioration factors and parameters that change with deterioration.

[0030] This deterioration estimation equation creation unit 14 preferably constructs a coating deterioration database consisting of parameters that change with deterioration, the deterioration time of the coating, and the deterioration environment temperature, and is the entity that executes the process of constructing a deterioration estimation equation from the deterioration database.

[0031] The model equation for estimating deterioration that is the basis of the linear regression analysis may be the Arrhenius equation or the Larson-Miller equation, but is not particularly limited thereto.

[0032] The "evaluation target material measurement unit 2" is a measuring device that non-destructively measures parameters that change as the test target material deteriorates with actual use, and is a process of measuring the physical properties and chemical state of components whose deterioration state is to be evaluated, for example. For this measurement, it is desirable to use the same measurement principle and measuring device as the "deteriorated coating measurement unit 12."

[0033] This evaluation target material measuring unit 2 preferably performs the process of non-destructively measuring parameters that change with the deterioration of the test target material that has deteriorated with actual use.

[0034] The "evaluation target material deterioration environment estimation unit 3" is a calculation processing unit that inputs parameters that change with the deterioration of the test target material into a deterioration estimation formula and calculates the deterioration environment of the test target material that has deteriorated with actual use.For example, it applies the parameters that change with deterioration obtained by the "evaluation target material measurement unit 2" to the correlation model created by the "deterioration estimation formula creation unit 14", calculates parameters of the deterioration factors, and estimates the environment in which the test target material is deteriorating.

[0035] This evaluation target material deterioration environment estimation unit 3 preferably inputs parameters that change as the test target material deteriorates into a deterioration estimation formula, and is the entity that executes the process of calculating the deterioration environment of the test target material whose deterioration has progressed with actual use.

[0036] The above correlation model is composed of parameters that change with deterioration and parameters of deterioration factors, and the parameters of the deterioration factors can be calculated based on the parameters that change with deterioration. It is assumed that the deterioration of the evaluation target material is progressing under the conditions of the calculated parameters of the deterioration factors, and processing is carried out in the "evaluation target material usable life calculation unit 4" described below.

[0037] The "evaluation target material usable period calculation unit 4" is a calculation processing unit that calculates the time until the inspection target material, which has deteriorated due to actual use, is judged to have deteriorated. For example, it calculates the usable period of the evaluation target material under the parameters of the deterioration factors estimated by the "evaluation target material deterioration environment estimation unit 3".

[0038] This evaluation target material usable life calculation unit 4 preferably executes the process of calculating the time until the test target material, which has deteriorated due to actual use, is judged to have deteriorated.

[0039] For example, if the coating film in question is required to have anti-rust properties and a beautiful appearance, the point at which cracks are found on the coating film surface is determined to be the end of its lifespan, and the time until that end of its lifespan is reached is calculated as the remaining usable period. The method for determining the lifespan differs depending on the performance required of the coating film, and it is desirable to determine it based on the performance of the deteriorated coating film prepared in the "deteriorated coating film preparation unit 11".

[0040] Hereinafter, a specific example will be given to evaluate the deterioration of a coating film due to heat and to estimate the usable life of the coating film, but the present invention is not limited to the following specific example.

[0041] In this specific example, the paint to be evaluated was a type of heavy-duty anticorrosion paint, which was applied to a metal substrate to prepare a coating film test piece (hereinafter referred to as coating film A). After the coating film was prepared, a certain period of drying time was allowed.

[0042] Accelerated thermal aging tests were conducted on Coating A under multiple conditions to produce aged coatings. The color information of the coating surface was measured at regular intervals while the coating was thermally aged at multiple test temperatures. A portable color difference meter (TE3250, AS ONE) was used to obtain the color information, and RGB values ​​were obtained as color information.

[0043] The RGB values ​​range from 0 to 255, and the values ​​change as the surface deteriorates because the color changes depending on the state of deterioration.

[0044] A database was constructed using test temperature and test time as parameters for deterioration factors, and RGB values ​​obtained as color information as parameters that change with deterioration. The database configuration is shown in Table 1.

[0045] [Table 1]

[0046] A deterioration estimation equation was constructed using the database in Table 1. The model for the deterioration estimation equation used the Larson-Miller equation shown in equation (1), where T is the absolute temperature, t is the duration of use, and a, b, and c are constants. P(R, G, B) was defined as a value composed of multiple parameters resulting from deterioration, as shown in equation (2), and the deterioration estimation equation in equation (3) was created. Furthermore, a multiple regression analysis was performed using the database in Table 1 to calculate the coefficients of equation (1). P=aTlog(t)+bT+C (1) P(R,G,B)=αR+βG+γB (2) αR+βG+γB=aTlog(t)+bT+C=a{Tlog(t)+(b / a)T}+c ··· (3)

[0047] The regression coefficients were calculated using the database in Table 1, and the results were determined as follows: α = 34.4, β = -57.1, γ = 19.2, a = 1, b = 15.7, and c = 8419.2. As a result, the deterioration estimation formula for coating A due to thermal deterioration was obtained as shown in Equation (4). 34.4R-57.1G+19.2B=Tlog(t)+15.7T+8419.7 ··· (4)

[0048] In equation (4), the term Tlog(t)+15.7T is composed of parameters for deterioration factors and represents the magnitude of the heat load on coating A. Furthermore, Tlog(t)+15.7T in equation (4) is called the Larson-Miller parameter, and will be referred to as LMP (Larson-Miller Parameter) below.

[0049] The left side of equation (4) is composed of αR + βG + γB and the color information of the coating surface. By inputting color information data into equation (4), the LMP can be calculated from the color information measurement results of coating A to which a certain thermal load has been applied.

[0050] Figure 2 shows a graph with LMP on the horizontal axis and αR + βG + γB on the vertical axis. As shown in Figure 2, a strong correlation was confirmed between LMP and αR + βG + γB, with a coefficient of determination of 0.986.

[0051] Next, we measured the color information of the evaluation material after it had deteriorated under a certain deterioration environment, simulating actual use. The measurement results were (R, G, B) = (209.2, 172.7, 99.1).

[0052] The evaluation target material has been in use for 336 hours. In this environment, the temperature of the coating is not always constant, but fluctuates depending on the temperature difference between day and night, making it difficult to calculate the usable time using the Arrhenius method, which is a general lifespan evaluation method. Figure 3 shows the typical degradation temperature T d The image shows the temperature of the coating film fluctuating.

[0053] Next, the obtained color information was substituted into the left side of equation (4) to calculate LMP, which was calculated as LMP = 7650. Therefore, the following equation (5) holds, and by solving this equation (5), the typical deterioration temperature T d is obtained. T d log(336)+15.7T d =7650 (5) T d =419.7(K)

[0054] The temperature calculated here is the typical degradation temperature T d It is written as T d When converted to Celsius temperature, it becomes 146.6℃. As mentioned above, the temperature of the coating film is constantly fluctuating, but in this deterioration environment, the constantly fluctuating temperature is kept at a constant value of T d It is possible to evaluate the progress of deterioration by using the following as a representative example.

[0055] Next, the calculation of the usable period of the coating film will be explained. The usable period varies depending on the performance required of the coating film, but in this example, the usable period was defined as the period until the appearance of the coating film is impaired and coating film cracks occur, which are a cause of a decrease in corrosion prevention performance.

[0056] During the process of producing deteriorated coatings, the surfaces of the coatings produced under each deterioration condition were observed, and the conditions under which cracking of the coating would occur were examined. It was confirmed that cracking of the coating would occur under conditions where the LMP was 8156.

[0057] Note that this "LMP" varies depending on which state is judged to be in a deteriorated state, even for the same material. Also, even if the state judged to be in a deteriorated state is the same, it varies depending on the material. In other words, it can be seen that it is possible to respond even if the criteria for materials and deterioration states change.

[0058] The degradation representative temperature T calculated above d In this case, the time t until LMP reaches 8156 e When calculating, the following equation (6) is obtained by applying the LMP equation. T d log(t e )+15.7T d =8156 (5) t e =5705(h)(6)

[0059] From these results, it is estimated that under this degradation environment, the LMP will reach 8156 after 5705 hours, causing the coating to crack. Since 336 hours of use have already passed, the remaining usable life of Coating A is estimated to be 5705 - 336 = 5369 (h).

[0060] As described above, it is possible to predict the usable life of a coating film that has deteriorated over time under actual usage conditions.

[0061] In this embodiment, a deterioration estimation formula was created based on the color information of the paint film to estimate the usable life of the paint film, but this is not limited to color information and various parameters that change with deterioration can be applied.

[0062] Next, the effects of this embodiment will be described.

[0063] The method for evaluating the deterioration state of a coating film in this embodiment described above includes the steps of: non-destructively measuring parameters that change with deterioration under multiple conditions for a coating film having the same configuration as the material to be inspected; constructing a coating film deterioration database consisting of parameters that change with deterioration, the deterioration time of the coating film, and the deterioration environment temperature, and constructing a deterioration estimation formula from the deterioration database; non-destructively measuring parameters that change with deterioration of the material to be inspected that has deteriorated with actual use; inputting the parameters that change with deterioration of the material to be inspected into the deterioration estimation formula to calculate the deterioration environment of the material to be inspected that has deteriorated with actual use; and calculating the time until the material to be inspected that has deteriorated with actual use is determined to have deteriorated.

[0064] In addition, the coating deterioration evaluation device 20 for evaluating the deterioration state of a coating in the above-described embodiment includes a deteriorated coating measurement unit 12 that non-destructively measures parameters that change with deterioration for a coating of the same configuration as the material to be inspected under multiple conditions; a deterioration estimation equation creation unit 14 that constructs a coating deterioration database consisting of parameters that change with deterioration, the deterioration time of the coating, and the deterioration environment temperature, and constructs a deterioration estimation equation from the deterioration database; an evaluation target material measurement unit 2 that non-destructively measures parameters that change with the deterioration of the material to be inspected that has deteriorated with actual use; an evaluation target material deterioration environment estimation unit 3 that inputs the parameters that change with the deterioration of the material to be inspected into the deterioration estimation equation and calculates the deterioration environment of the material to be inspected that has deteriorated with actual use; and an evaluation target material usable period calculation unit 4 that calculates the time until the material to be inspected that has deteriorated with actual use is determined to have deteriorated.

[0065] Therefore, it is possible to predict with higher accuracy than before the usable period of a coating film that has deteriorated over time under actual usage conditions.

[0066] Furthermore, since the color information of the coating film is used as a parameter that changes as the coating film deteriorates, highly accurate evaluation can be achieved using a parameter that can be easily measured externally.

[0067] Furthermore, by using the Larson-Miller parameter equation as a model for the deterioration estimation equation, it is possible to achieve evaluation with higher accuracy.

[0068] Furthermore, by evaluating the state of deterioration of the coating film due to heat, it becomes possible to evaluate using the external parameters that have the greatest effect on deterioration, allowing for evaluation that is more in line with the actual situation.

[0069] <Other> The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. The above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to having all of the described configurations. [Explanation of symbols]

[0070] 1...Database section 2...Measurement section for evaluation material 3...Deterioration and Environmental Assessment of Materials Subject to Evaluation 4...Calculation of usable life of evaluated material 5…Usable period display section 11...Deteriorated coating film production section 12...Deteriorated coating film measurement section 13...Database Construction Department 14...Deterioration estimation formula creation section 20...Paint film deterioration evaluation device

Claims

1. A method for evaluating the deterioration state of a coating film, comprising: a step of non-destructively measuring parameters that change with deterioration for a coating film having the same configuration as the test material under multiple conditions; constructing a deterioration database of the coating film, which database includes parameters that change with the deterioration, the deterioration time of the coating film, and the deterioration environment temperature, and constructing a deterioration estimation formula from the deterioration database; a step of non-destructively measuring parameters that change with deterioration of the test object material that has progressed with actual use; a step of inputting parameters that change with the deterioration of the test object material into the deterioration estimation formula to calculate a deterioration environment of the test object material whose deterioration has progressed with the actual use; and calculating a time period until the test object material, which has deteriorated due to actual use, is determined to have deteriorated. A method for evaluating paint film deterioration.

2. The method for evaluating deterioration of a coating film according to claim 1, The color information of the coating film is used as a parameter that changes with deterioration of the coating film. A method for evaluating paint film deterioration.

3. The method for evaluating deterioration of a coating film according to claim 1 or 2, The Larson-Miller parameter equation is used as a model for the deterioration estimation equation. A method for evaluating paint film deterioration.

4. The method for evaluating deterioration of a coating film according to claim 3, Evaluate the thermal deterioration of the coating film A method for evaluating paint film deterioration.

5. An apparatus for evaluating the deterioration state of a coating film, a deteriorated coating film measurement unit that nondestructively measures parameters that change with deterioration for a coating film having the same configuration as the inspection target material under multiple conditions; a deterioration estimation equation creation unit that creates a deterioration database of the coating film, including parameters that change with the deterioration, the deterioration time of the coating film, and the deterioration environment temperature, and creates a deterioration estimation equation from the deterioration database; an evaluation object material measurement unit that nondestructively measures parameters that change with deterioration of the inspection object material that has progressed with actual use; an evaluation target material degradation environment estimation unit that inputs parameters that change with the degradation of the test target material into the degradation estimation formula and calculates the degradation environment of the test target material whose degradation has progressed with the actual use; and an evaluation object material usable life calculation unit that calculates the time until the inspection object material, which has deteriorated due to actual use, is determined to have deteriorated. Coating deterioration evaluation device.

6. The coating deterioration evaluation device according to claim 5, The color information of the coating film is used as a parameter that changes with deterioration of the coating film. Coating deterioration evaluation device.

7. 7. The coating deterioration evaluation device according to claim 5 or 6, The Larson-Miller parameter equation is used as the model for the deterioration estimation equation. Coating deterioration evaluation device.

8. The coating deterioration evaluation device according to claim 7, Evaluate the thermal deterioration of the coating film Coating deterioration evaluation device.

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