Weather resistance performance evaluation method

Abstract

To provide a weatherability performance evaluation method that can reduce a weatherability test time and reduce the time required for weatherability performance evaluation.SOLUTION: A weatherability performance evaluation method executes temperature increase processing of increasing the temperature of an inert gas atmosphere at 50°C in which a sample is arranged to a predetermined measurement temperature at a rate of temperature increase of 20°C / min, and subsequently executes maximum value detection processing of detecting the maximum value of the amount of chemiluminescence emission of the sample, while maintaining the inert gas atmosphere at the measurement temperature, thereby detecting a maximum value CL0 (steps S11, S12). The method executes a weatherability test for the sample for which weatherability performance is to be predicted (step S13), executes the temperature increase processing and the maximum value detection processing similarly to the previous steps to detect a maximum value CL 384 (step S14), calculates the ratio of the maximum value CL384 to the maximum value CL0 (step S15), and predicts weatherability from the maximum value ratio of "the maximum value CL384 / the maximum value CL0" (steps S16-S18).SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a weather resistance evaluation method.

Background Art

[0002] When evaluating the weather resistance of organic or inorganic materials, such as how much they deteriorate due to light from the sun, heat, moisture such as rain, oxygen in the atmosphere, etc., it is common to conduct outdoor exposure tests or weather resistance tests until an appearance change occurs in the sample.

[0003] Among the above evaluation methods, the outdoor exposure test is the best method because it can evaluate the actual deterioration state although it is affected by regional differences. However, for example, for a sample assuming a 10-year weather resistance guarantee, a weather resistance test period of more than 10 years is required, so there is a problem that it takes a long time to obtain an evaluation result.

[0004] Therefore, a method has been proposed to evaluate the weather resistance of a sample by conducting a weather resistance test using a weather resistance tester with a light source having a higher output than sunlight. As a weather resistance tester, for example, there is a Sunshine Weather Ometer (SWOM) equipped with a light source composed of a carbon arc having a higher output than sunlight, but it still takes a long time to obtain an evaluation result.

[0005] On the other hand, a Metal Weather Meter (MW) or Super UV (SUV), which is an example of another weather resistance test, has a metal halide lamp as a light source having a higher output than a carbon arc, so the acceleration rate of deterioration can be increased and the test time can be shortened. However, the accumulation of data for outdoor exposure tests is small, and there are also large variations in the correlation with actual exposure, so the accuracy of the evaluation results is not necessarily sufficient at present.

[0006] Furthermore, to shorten the time required for weather resistance testing, there is also a method for evaluating weather resistance performance using the chemiluminescence method (JIS K7351). For example, a method has been disclosed that evaluates weather resistance by correlating the degradation time obtained in a previous weather resistance test with the apparent activation energy calculated from the amount of chemiluminescence of samples treated with different processing times under the same weather resistance test conditions. However, because the apparent activation energy is calculated and used, at least three temperature conditions are required during chemiluminescence measurement. Therefore, there is a problem in that the number of samples and measurements are large, and the measurement takes a long time. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2005-337783 [Patent Document 2] Patent No. 6188625 [Patent Document 3] Japanese Patent Publication No. 2002-195951 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to solve the above-mentioned unresolved problems and to provide a weather resistance evaluation method that can shorten the weather resistance test time and the time required to evaluate weather resistance performance. [Means for solving the problem]

[0009] To achieve the above objective, according to one aspect of the present invention, a weather resistance evaluation method for predicting the weather resistance of a sample containing an olefin polymer material, comprising: a first heating step of placing the sample in an inert gas atmosphere at a preset initial temperature and heating the inert gas atmosphere to a predetermined measurement temperature at a preset heating rate; and a first measurement step of detecting the maximum value of the chemiluminescence emission amount of the sample while maintaining the inert gas atmosphere at the measurement temperature after the first heating step, wherein the maximum value of the chemiluminescence emission amount obtained by this process is the A weather resistance evaluation method is provided, comprising: a step of preparing a sample as a maximum value; a test step of performing a weather resistance test on a target sample which is the sample for which the weather resistance performance is to be predicted; a second heating step of performing the heating process on the target sample after the test step in the same environment as the first heating step; a second measurement step of performing the maximum value detection process on the target sample after the second heating step; and a prediction step of calculating the ratio between the first maximum value and the second maximum value which is the maximum value measured in the second measurement step, and predicting the weather resistance performance of the target sample from the ratio of the two maximum values. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to shorten the weather resistance test time, and as a result, to provide a weather resistance performance evaluation method that can shorten the time required to evaluate weather resistance performance. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view showing an example of a decorative sheet to which the weather resistance performance evaluation method according to an embodiment of the present invention has been applied. [Figure 2] This is an example of an emission curve showing the relationship between measurement time and chemiluminescence emission amount, obtained from chemiluminescence measurements of a laminate containing an olefin-based polymer material. [Figure 3] This is a flowchart showing an example of a chemiluminescence measurement procedure. [Figure 4]This flowchart shows an example of a procedure for evaluating weather resistance performance. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] The following diagrams are schematic, and it should be noted that the relationship between thickness and planar dimensions, the ratio of thicknesses of each layer, etc., may differ from reality. Therefore, specific thicknesses and dimensions should be determined by referring to the explanation below.

[0014] Furthermore, the embodiments described below illustrate devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims described in the patent claims. [Laminate]

[0015] Figure 1 shows an example of a laminate having a layer containing an olefin polymer material, as an example of a sample containing an olefin polymer material, and is a cross-sectional view showing an example of the schematic structure of a decorative sheet 1 when a decorative sheet is formed as a laminate.

[0016] The decorative sheet 1 consists of a laminate in which a base material layer 2, a pattern printing layer 3, a transparent resin layer 4, and a surface protection layer 5 are laminated in this order. The transparent resin layer 4 is composed of an olefin-based polymer material.

[0017] Furthermore, the sample is not limited to the decorative sheet 1 shown in Figure 1; any laminate having at least one layer containing an olefin-based polymer material can be used. [Chemiluminescence measurement]

[0018] Figure 2 is a luminescence curve showing the relationship between the measurement time and the amount of chemiluminescence emission (hereinafter also simply referred to as the emission amount) obtained from the chemiluminescence measurement of a laminate having a layer containing an olefin-based polymer material.

[0019] Chemiluminescence measurement is a method of measuring the emission intensity of chemiluminescence generated when a sample is heated, and is a method of measuring the degree of oxidation of the sample. Chemiluminescence measurement can be carried out based on JIS K 7351, and a known method using a chemiluminescence analyzer can be adopted. For example, it can be measured using the apparatus shown in FIG. 1 of Patent Document 3. Specifically, an apparatus including a sample storage chamber, heating means, and light receiving and detecting means can be mentioned. The sample storage chamber is a container for arranging a sample inside, and is a chamber having a window through which chemiluminescence generated from the sample can pass, a gas supply port for supplying gas to the container, and a gas discharge port for discharging the gas after the reaction. It is only necessary that the chamber has these components, and the design can be appropriately changed according to the type of sample used. By connecting a gas flow meter and a gas pump to the gas supply port, the type and flow rate of the supplied gas can be controlled. Also, the flow rate of the gas can be appropriately changed depending on temperature conditions, the type and amount of the sample, etc., and is usually adjusted to the range of several tens mL / min to several hundreds mL / min.

[0020] In this embodiment, chemiluminescence measurement is performed in an inert gas atmosphere. The inert gas atmosphere is not particularly limited, and known inert gases such as nitrogen and argon gas can be used. The flow rate when supplying the inert gas into the container can be set in consideration of replacement of the sample atmosphere and mixing due to leakage of air during measurement. For example, about 50 cc / min is preferable. Also, it is preferable to replace with an inert gas similar to that during chemiluminescence measurement for about 1 minute after installing the sample in the sample chamber. By replacing the sample chamber with an inert gas, it is possible to prevent oxidation by oxygen in the sample chamber.

[0021] The shape of the sample to be measured is not specifically defined and can be set appropriately according to the size of the sample cell in the sample chamber. From the viewpoint of being able to accurately measure weather resistance performance, it is preferable that the surface area and thickness of samples with different degrees of degradation be approximately the same. Specific sample shapes include circular samples with a diameter of 10 mm to 20 mm and a thickness of 0.1 mm to 1 mm.

[0022] The heating means can be any means capable of heating the inside of the sample chamber container, and any known heating means (such as a heater) capable of heating above the temperature at which a reaction occurs on the sample can be used as appropriate. In this invention, the temperature range in which peroxide radicals can be generated can be set appropriately according to the type of sample, the degree of degradation, etc. The temperature conditions can also be set as appropriate, such as constant temperature or heating process.

[0023] In this embodiment, the measurement temperature is set to be below the melting point (Tm) of the olefin polymer material. Preferably, it is between Tm°C and Tm-30°C, more preferably between Tm-5°C and Tm-15°C. If the measurement is above the melting point, the sample will melt, resulting in poor measurement accuracy. Also, if the measurement temperature is too low, the amount of light emitted will be low, and the difference between the maximum amount of light emitted from a sample (laminated material) that has not undergone the weather resistance test described later and the maximum amount of light emitted from a sample (laminated material target sample) that has undergone the weather resistance test will become small, which may make it impossible to accurately evaluate the weather resistance performance.

[0024] The light receiving and detection means is not particularly limited as long as it is capable of receiving and detecting the desired chemiluminescence. For example, a means capable of receiving and detecting light in the wavelength range of 300 nm to 700 nm can be suitably used.

[0025] The light detection means is typically connected to a counting means. Any known counting means can be used as appropriate; for example, a light pulse discriminator, an analog counter, or image processing software can be used. Such a counting means is connected to an output means (display, printer, etc.) and can output a graph of the emission spectrum, etc., based on the data input from the counting means. In other words, when the light detection means receives light, the signal generated by the light detection means is sent to the counting means. This signal is then converted by the counting means into data such as total emission intensity and emission intensity distribution, and the output means outputs a graph of the emission spectrum, etc., based on this data.

[0026] The emission curve shown in Figure 2 can be obtained by performing chemiluminescence measurements under the above-described conditions on a laminate containing an olefin polymer material after a weathering test has been conducted for a predetermined time using a weathering tester with a metal halide lamp as the light source. In other words, an emission curve with characteristics peaking at the maximum emission amount CLt shown in Figure 2 can be obtained.

[0027] Furthermore, when chemiluminescence measurements are performed using the same procedure on laminates containing olefin-based polymer materials that have not undergone weather resistance testing, an emission curve with a peak as shown in Figure 2 can be obtained. In this case, the peak of the emission curve is defined as the maximum emission amount CL0.

[0028] Furthermore, by calculating the ratio CLt / CL0 between the maximum luminescence CLt in chemiluminescence measurements of the laminate after weathering testing and the maximum luminescence CL0 in chemiluminescence measurements of the laminate before weathering testing, it becomes possible to evaluate the weather resistance performance of a laminate containing a layer of olefin-based polymer material.

[0029] In other words, laminates containing layers of olefin-based polymer materials generate radicals when exposed to ultraviolet light and heat during weathering tests.

[0030] This radical reacts with oxygen to form a peroxyl radical, and a bimolecular reaction of the peroxyl radical produces an excited carbonyl and singlet oxygen. Chemiluminescence detects the light emitted when the generated excited carbonyl and singlet oxygen return from the excited state to the ground state; therefore, a smaller CLt / CL0 ratio indicates higher weather resistance. Thus, weather resistance can be evaluated by comparing the maximum light emission CLt of the laminate after weather resistance testing with the maximum light emission CL0 of the laminate before weather resistance testing.

[0031] Furthermore, it is preferable that the laminate used for detecting the maximum luminescence CL0, which has not undergone weather resistance testing, and the laminate used as the target sample for predicting weather resistance performance, which has undergone weather resistance testing, have the same composition and size.

[0032] In other words, since the laminate used to detect the reference value CL0 of the maximum luminescence and the laminate to detect the maximum luminescence CL384 are separate, by making the composition and size of both similar, it is possible to suppress fluctuations in the ratio of the maximum luminescence values ​​due to differences in luminescence caused by differences in composition and size.

[0033] Next, an example of the chemiluminescence measurement procedure will be explained with the help of the flowchart shown in Figure 3. The method for measuring chemiluminescence is the same for both the treatment of laminates that have not undergone weathering testing and the treatment of laminates that have undergone weathering testing.

[0034] First, the gas atmosphere inside the sample containment chamber is adjusted to an inert gas atmosphere at the initial temperature (e.g., 50°C) (Step S1).

[0035] Next, the laminated material to be used as the sample is placed in the sample containment chamber (step S2). Then, a heating process is performed to raise the temperature at a predetermined heating rate (e.g., 20°C / min) (step S3, first heating step, second heating step). When the predetermined measurement temperature is reached (step S4), the heating is stopped, the predetermined measurement temperature is maintained, and the measurement of the amount of light emitted is started (step S5).

[0036] Then, when the luminescence amount is measured for a predetermined measurement time (for example, 10 minutes) (step S6), a maximum value detection process is performed to acquire the maximum value of the luminescence amount during the measurement time as the maximum luminescence amount (step S7, first measurement step, second measurement step). At this time, if the object to be measured is a laminate that has not undergone weather resistance testing, the acquired maximum luminescence amount will be the maximum luminescence amount (first maximum value) CL0, and if it is a laminate that has undergone weather resistance testing, the acquired maximum luminescence amount will be the maximum luminescence amount (second maximum value) CL384.

[0037] The initial temperature, which is the temperature inside the sample chamber when placing a sample in it, is set to a temperature at which the sample placed inside the sample chamber does not emit light, for example, 50°C.

[0038] The heating rate in the sample chamber is set to between 10°C / min and 100°C / min. In other words, if the heating rate is too low, the emission curve will become broad, so the heating rate is set to a level that allows for obtaining a waveform that can accurately read the maximum emission amount.

[0039] The measurement temperature, which is the temperature at which the measurement of luminescence begins, is set to a value that provides sufficient luminescence to represent both the maximum luminescence of the laminate before weathering testing and the maximum luminescence of the laminate after weathering testing, and to obtain a difference value of a certain magnitude between the two maximum luminescence values. Furthermore, the measurement temperature is set to be below the upper limit of the allowable temperature of the weathering testing equipment (e.g., 350°C) and to a value of 100°C or higher. Preferably, the measurement temperature is set to a value between 100°C and the melting point of the laminate.

[0040] The measurement time for measuring the amount of light emitted is set to the time required to obtain the maximum amount of light emitted. In other words, as shown in the light emission curve in Figure 2, the amount of light emitted has a characteristic with a peak. The measurement time is set to a value that allows the peak value of the amount of light emitted to be identified from the light emission curve, for example, to about 10 minutes.

[0041] The initial temperature, heating rate, measurement temperature, and measurement time can be arbitrarily set according to the structure and composition of the laminate being measured. [Weather resistance performance evaluation method]

[0042] An example of the procedure for evaluating weather resistance performance is explained with the flowchart in Figure 4.

[0043] First, a laminate having a layer containing an olefin-based polymer material is prepared (step S11).

[0044] Furthermore, a maximum luminescence CL0 of a laminate with the same configuration and similar size as the prepared laminate, but which has not undergone weather resistance testing, is prepared (step S12). This maximum luminescence CL0 of the laminate that has not undergone weather resistance testing may be detected in advance or detected anew. By detecting the maximum luminescence CL0 in advance, it is not necessary to obtain the maximum luminescence CL0 at the stage before weather resistance testing is performed each time weather resistance performance evaluation is conducted, thereby shortening the time required for weather resistance performance evaluation.

[0045] Next, a weather resistance test is performed on the prepared laminate (Step S13 Test Process). Specifically, a weather resistance test is performed for 384 hours (16 days) using a weather resistance tester with a metal halide lamp as the light source. If the test period is longer than 384 hours, it is too long as a practical weather resistance test period, and if it is less than 384 hours, depending on the sample, sufficient deterioration to be detected may not begin due to the effect of weather-resistant agents, etc. The weather resistance test period is not necessarily limited to 384 hours, and it is preferable to set it to a time sufficient for deterioration to begin, depending on the material, size, shape, etc. of the laminate.

[0046] Next, chemiluminescence measurements are performed on the laminate containing a layer of olefin-based polymer material that has undergone a 384-hour weathering test (step S14). Then, the maximum luminescence CL384 of the laminate that has undergone the 384-hour weathering test is determined from the measurement results of the chemiluminescence measurement.

[0047] Then, the ratio of maximum luminescence CL384 / CL0 is calculated (step S15), and if the ratio of maximum luminescence CL384 / CL0 is less than or equal to the evaluation value "10" (step S16), it is evaluated as a highly weather-resistant laminate (step S17). Conversely, if the ratio of maximum luminescence CL384 / CL0 is greater than the evaluation value "10" (step S16), it is evaluated as having insufficient weather resistance when used in an outdoor environment (step S18, prediction process).

[0048] Note that while the evaluation value is set to "10" here, the evaluation value is not limited to "10" and should be set according to the required weather resistance performance. For example, the evaluation value could be set by pre-calculating the ratio of maximum luminescence CL384 / CL0 for a sample with the required weather resistance performance and setting this ratio as the evaluation value. 〔effect〕

[0049] As described above, the weather resistance performance evaluation method according to the present invention allows for the evaluation of weather resistance performance at the very early stages of deterioration before any changes in appearance occur, which could not be determined by conventional weather resistance performance evaluation methods, using the chemiluminescence method. This eliminates the need to conduct weather resistance tests until changes in appearance occur, thereby achieving both a reduction in weather resistance test time and a reduction in the time required for weather resistance performance evaluation.

[0050] In particular, in the case of a laminate having at least one layer containing an olefin-based polymer material, a weather resistance test is performed for 384 hours, and it is possible to determine in a shorter time whether or not the laminate has high weather resistance by determining whether or not the ratio of the maximum luminescence CL384 / CL0 at that time is 10 or less. [Variation]

[0051] In the above embodiment, the case in which the measurement time is set to a time that allows for the acquisition of the maximum light emission amount (for example, about 10 minutes) was described, but it is not limited to this.

[0052] In other words, all that is needed is to obtain the maximum luminescence, that is, to detect the peak. Therefore, one can observe the trend of luminescence and, when the luminescence begins to decrease, consider this point as the peak and the luminescence at that time as the maximum luminescence. In this case, since the measurement of luminescence can be stopped once the peak is detected, measurements will only be taken for the necessary period, allowing for efficient measurement. [Examples]

[0053] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. (Weather resistance performance evaluation method)

[0054] A weather resistance test was conducted on a decorative sheet consisting of the laminate shown in Figure 1 under the weather resistance test conditions described below, and chemiluminescence measurements were performed. The conditions for chemiluminescence measurement are shown in Table 1. The decorative sheet used in this weather resistance test is as follows. The evaluation results are shown in Table 2. Thus, it was confirmed that weather resistance performance can be evaluated by measuring the chemiluminescence after the weather resistance test and comparing CL384 / CL0.

[0055] [Table 1]

[0056] [Table 2] <Example 1>

[0057] A wood grain pattern was gravure printed onto an opaque polyethylene base roll (70 μm thick) using a two-component urethane ink (V180; manufactured by Toyo Ink Co., Ltd.) to create a pattern layer (3 μm thick) and thus a substrate was obtained. A transparent resin layer composition, as shown below, was extruded and laminated to this substrate with a thickness of 80 μm via a dry laminating adhesive (Takelac A540; manufactured by Mitsui Chemicals, Inc.) (2 μm thick).

[0058] Furthermore, the following surface protection layer composition was applied to the transparent resin layer with a gravure coat and dried, then cured at 25°C for 3 days to obtain the decorative sheet of Example 1. (Transparent resin layer composition) • Transparent homopolypropylene resin (F-300SP; manufactured by Prime Polymer Co., Ltd.)

[0059] · 99 parts by mass • UV absorber (Tinosorb S; manufactured by BASF Japan Ltd.)

[0060] ... 0.5 part by mass • Light stabilizer (Chinubin XT55; manufactured by BASF Japan Ltd.)

[0061] ... 0.5 part by mass (Surface protective layer composition) • Main component (methyl methacrylate / 2-hydroxyethyl methacrylate copolymer = 90 / 10)

[0062] ... 90 parts by mass • UV absorber (ADEKA LA-F70; manufactured by ADEKA Corporation)

[0063] ... 5 parts by mass • Light stabilizer (Tinuvin 123; manufactured by BASF Japan Ltd.)

[0064] ... 5 parts by mass • Hardening agent (Takenate D170; manufactured by Mitsui Chemicals, Inc.) ... 10 parts by mass • Solvent (ethyl acetate) ... 240 parts by mass <Example 2>

[0065] The decorative sheet of Example 2 was obtained in the same manner as in Example 1, except that the ultraviolet absorber in the transparent resin layer composition of Example 1 was Chinuvin 326, manufactured by BASF Japan Ltd. <Example 3>

[0066] The decorative sheet of Example 3 was obtained in the same manner as in Example 1, except that the amount of the ultraviolet absorber Adekastab LA-F70 added to the surface protective layer composition of Example 1 was 3 parts by mass. <Example 4>

[0067] The decorative sheet of Example 4 was obtained in the same manner as in Example 1, except that the ultraviolet absorber in the surface protective layer of Example 1 was Chinuvin 326; manufactured by BASF Japan Ltd. <Comparative Example 1>

[0068] The UV absorber and light stabilizer of the surface protection composition in Example 1 were omitted, and only the main component, curing agent, and solvent were used. The decorative sheet of Comparative Example 1 was obtained in the same manner as in Example 1. <Comparative Example 2>

[0069] A decorative sheet for Comparative Example 2 was obtained in the same manner as in Example 2, except that the ultraviolet absorber in the surface protective layer composition of Example 2 was Chinuvin P, manufactured by BASF Japan Ltd. <Comparative Example 3>

[0070] In Comparative Example 3, the transparent resin layer composition of Example 1 was prepared using only transparent homopolypropylene resin, without the addition of UV absorbers and light stabilizers. The decorative sheet of Comparative Example 3 was obtained using the same method as in Example 1. (Weathering resistance test conditions)

[0071] A metal weatherometer (manufactured by Daipla Wintes Co., Ltd.) was prepared as a weather resistance testing machine using a metal halide lamp as the light source.

[0072] Light source lamp: MW-60W

[0073] Filter: KF-1 (295nm to 780nm)

[0074] As shown in Table 3 below, the weather resistance test consisted of 16 cycles (384 hours) of irradiation → water spray → condensation → water spray.

[0075] [Table 3] (Chemiluminescence measurement)

[0076] Chemiluminescence measurements were performed on decorative sheets of Examples 1-4 and Comparative Examples 1-3, both after and without weather resistance testing. Based on JIS K 7351, the temperature was increased from an initial 50°C at a heating rate of 20°C / min under a nitrogen gas atmosphere. After reaching the predetermined measurement temperature, the measurement time was set to 10 minutes, and the maximum luminescence was measured while maintaining the measurement temperature. The maximum luminescence CL0 of the decorative sheet without weather resistance testing and the maximum luminescence CL384 of the decorative sheet after weather resistance testing were determined, and CL384 / CL0 was calculated.

[0077] Measurement device: Chemiluminescence analyzer CLA-FS4 manufactured by Tohoku Electronics Industry Co., Ltd.

[0078] Sample size: φ18mm (evaluation)

[0079] For each decorative sheet in Examples 1-4 and Comparative Examples 1-3, a weather resistance test was conducted under the above weather resistance test conditions, and changes in appearance were checked every 24 hours. The time until cracks were observed on the outermost surface was defined as the lifespan of each decorative sheet, and the weather resistance performance was evaluated accordingly.

[0080] Evaluation Criteria

[0081] ◎: Over 1560 hours

[0082] ○: Over 600 hours

[0083] ×: Less than 600 hours

[0084] In this evaluation, if the time until cracks are observed on the outermost surface (lifespan) is 600 hours or more, the decorative sheet is considered to have high weather resistance (excellent weather resistance) and is deemed to pass with a "○". Furthermore, if the evaluation result is "◎", it indicates that the sheet can be maintained for 10 years or more when exposed to the outdoors.

[0085] Furthermore, a microscope and laser microscope were used to examine cracks in the outermost layer. The results obtained are shown in Table 2.

[0086] Tables 1 and 2 confirm that, in Examples 1 to 4, a highly weather-resistant decorative sheet can be obtained compared to Comparative Examples 1 to 3. [Explanation of Symbols]

[0087] 1 Decorative sheet 2 Original fabric 3. Pattern printing layer 4 Transparent resin layer 5 Surface protective layer

Claims

1. A weather resistance evaluation method for predicting the weather resistance performance of a sample containing an olefin-based polymer material, A first heating step involves placing the sample in an inert gas atmosphere at a preset initial temperature and performing a heating process to raise the inert gas atmosphere to a predetermined measurement temperature at a preset heating rate; and a first measurement step involves maintaining the inert gas atmosphere at the measurement temperature after the first heating step and performing a maximum value detection process to detect the maximum value of the chemiluminescence emission amount of the sample; and a step of preparing the maximum value of the chemiluminescence emission amount obtained by this process as the first maximum value. A test step in which a weather resistance test is performed on the target sample, which is the sample for which the weather resistance performance is to be predicted, A second heating step is performed on the target sample after the test step, under the same environment as the first heating step, A second measurement step, after the second heating step, involves performing the maximum value detection process on the target sample, A prediction step which involves calculating the ratio between the first maximum value and the second maximum value which is the maximum value measured in the second measurement step, and predicting the weather resistance performance of the target sample from the ratio of these maximum values, Equipped with, A method for evaluating weather resistance, characterized in that the measurement temperature (°C) is within the range of Tm - 30 or more and Tm or less, where Tm is the melting point (°C) of the olefin polymer material.

2. The weather resistance performance evaluation method according to claim 1, wherein the sample is a decorative sheet having a laminate comprising a base layer, a printing layer, a transparent resin layer, and a surface protective layer, and the transparent resin layer comprises the olefin polymer material.

3. The weather resistance performance evaluation method according to claim 2, characterized in that at least one of the transparent resin layer and the surface protective layer contains at least one of an ultraviolet absorber and a light stabilizer.

4. The weather resistance performance evaluation method according to claim 2, characterized in that at least one of the transparent resin layer and the surface protective layer contains both an ultraviolet absorber and a light stabilizer.

5. The weather resistance performance evaluation method according to claim 2, characterized in that both the transparent resin layer and the surface protective layer contain both an ultraviolet absorber and a light stabilizer.

6. The weather resistance performance evaluation method according to any one of claims 1 to 5, characterized in that the prediction step predicts high weather resistance when the ratio and a preset evaluation value satisfy "the second maximum value / the first maximum value ≤ evaluation value".

7. The aforementioned heating process is a process in which the inert gas atmosphere is heated from the initial temperature of 50°C to the measurement temperature at a heating rate of 20°C / min. The weather resistance evaluation method according to any one of claims 1 to 6, characterized in that the maximum value detection process measures the amount of chemiluminescence emission from the time the inert gas atmosphere reaches the measurement temperature until a measurement time of 10 minutes has elapsed, and selects the maximum value among the measured values ​​as the maximum value of the chemiluminescence emission.

8. The weather resistance performance evaluation method according to any one of claims 1 to 7, characterized in that the measurement temperature is 100°C or higher.

9. The weather resistance performance evaluation method according to any one of claims 1 to 8, characterized in that the measurement temperature (°C) is within the range of Tm-15 or more and Tm-5 or less, where Tm is the melting point (°C) of the olefin polymer material.

10. The weather resistance test is a weather resistance test using a metal halide lamp as a light source, as described in any one of claims 1 to 9.

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