Degradation testing apparatus, degradation testing method, and method for producing a sample

Abstract

Degradation tests of objects are conducted in extreme environments such as the stratosphere. [Solution] One aspect of the present disclosure is a degradation testing apparatus for testing the degradation of a sample, comprising: a sealed container; a sample holding unit for holding the sample in the sealed container; a light source unit for irradiating the sample with light; and a concentration adjustment unit for reducing the number of oxygen molecules in the sealed container to less than the number of oxygen molecules in an atmospheric pressure environment. The concentration adjustment unit controls the number of oxygen molecules in the sealed container to be 5.11 × 10^21 or less when converted to a volume of 1 liter, and the light source unit emits light including wavelengths of 300 nm or less.

Description

[Technical Field]

[0001] This invention relates to a degradation testing apparatus, a degradation testing method, and a method for producing a sample. [Background technology]

[0002] There are various methods for weather resistance testing to evaluate the degradation of materials such as resins and polymers. For example, representative real-world exposure testing sites that use actual sunlight as a light source include the Arizona Test Site, Miyako Island Test Site, and Choshi Test Site. To conduct weather resistance testing in a shorter time than real exposure indoors, methods are used to simulate day and night by using artificial sunlight such as xenon, metal halide, or carbon arc as light sources, or to accelerate the degradation of the sample by spraying it with a shower simulating rain, or by controlling humidity and temperature, thereby obtaining test results in a shorter time.

[0003] Techniques for conducting weather resistance tests are known, as described in Patent Documents 1, 2, and 3. The weather resistance testing apparatus described in Patent Documents 1, 2, and 3 utilizes a high-intensity light source and also raises the atmospheric pressure (e.g., oxygen partial pressure) inside the apparatus container where the sample is placed to higher than atmospheric pressure in order to accelerate the weather resistance test. Known techniques for conducting degradation tests on existing materials include the ozone environment tester described in Non-Patent Document 1 and the space environment evaluation test described in Non-Patent Document 2. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 1-21891 [Patent Document 2] Special Publication No. 1-28897 [Patent Document 3] Japanese Patent Publication No. 2022-176912 [Non-patent literature]

[0005] [Non-Patent Document 1] Gunma Prefectural Industrial Technology Center: Introduction to Ozone Environment Testing Equipment [online] [Accessed November 1, 2024]<https: / / www.tec-lab.pref.gunma.jp / intro / business / ozone / > [Non-Patent Document 2] Chemitox Co., Ltd., Space Environment Evaluation Testing, [online], [Retrieved November 1, 2024] <https: / / www.chemitox.co.jp / business / rail-air / space_environment_test?doing_wp_cron=1723445125.7885079383850097656250> [Overview of the project] [Problems that the invention aims to solve]

[0006] In recent years, private companies have been increasingly entering the space industry, and there are attempts to fly aircraft equipped with communication functions at high altitudes such as the stratosphere, and to have them function as communication base stations. In order to achieve long-duration flights, it is preferable to use lightweight materials for the aircraft equipment, and materials such as resins, polymers, and carbon fibers are being considered.

[0007] In extreme environments such as the stratosphere, environmental factors such as the wavelength range of sunlight, air density, and temperature differ significantly from those near the ground. The wavelength of sunlight in the stratosphere is shorter than that of sunlight reaching the ground. In addition, while air density is lower in the stratosphere, the ozone concentration is higher. Furthermore, temperatures in the stratosphere are several tens of degrees below zero, causing very large temperature changes as the temperature of parts of the aircraft's equipment that are exposed to sunlight rises. There are no known test methods to estimate how materials such as resins and polymers degrade under such conditions and to estimate their service life.

[0008] The weather resistance testing apparatus described in Patent Documents 1 and 2 uses a high-intensity light source and increases the air pressure (e.g., oxygen partial pressure) inside the apparatus container where the sample is placed to greater than atmospheric pressure in order to accelerate the weather resistance test. The weather resistance testing apparatus described in Patent Document 3 increases the air pressure (e.g., oxygen partial pressure) inside the apparatus container where the sample is placed to accelerate the weather resistance test, and further performs water spraying on the sample, humidification, and temperature control of the sample in order to mimic the changes in appearance in a real environment. However, the weathering tests described in Patent Documents 1, 2, and 3 above are applied to the deterioration of samples near the ground. Furthermore, the tests performed by the weathering testing apparatus in Patent Documents 1, 2, and 3 are accelerated tests against environments near the ground, and are significantly different from extreme environments such as the stratosphere. Therefore, they do not constitute weathering tests in extreme environments.

[0009] Furthermore, Non-Patent Document 1 describes a combined test apparatus capable of irradiating light in ozone gas as a test method simulating the stratosphere. Non-Patent Document 2 describes a test apparatus and method capable of changing the temperature from low to high under reduced pressure as a space environment evaluation test. In the stratosphere, as described in Non-Patent Documents 1 and 2, the environment is characterized by high ozone concentration, low temperature, and reduced pressure compared to the ground. In addition, sunlight is irradiated, causing the sample temperature to rise during irradiation. Furthermore, because the wavelengths of the irradiated sunlight are not absorbed by the atmosphere, or are only slightly absorbed, light in the wavelength range below 290 nm is also irradiated onto the sample. Moreover, although the oxygen concentration remains approximately 20%, the number of oxygen molecules decreases. Therefore, conducting environmental tests in extreme environments such as the stratosphere requires high ozone concentration, reduced pressure, low temperature, low oxygen molecule count, and light containing wavelengths below 290 nm. The development of test equipment and methods incorporating these conditions is highly desirable.

[0010] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a deterioration test apparatus capable of performing a deterioration test of an object in an extreme environment such as the stratosphere, a deterioration test method, and a method for manufacturing a sample.

Means for Solving the Problems

[0011] The present disclosure has been made to solve the above-described problems, and one aspect of the present disclosure is a deterioration test apparatus for testing the deterioration of a sample, including a sealed container, a sample holding unit for holding the sample in the sealed container, a light source unit for irradiating the sample with light, and a concentration adjustment unit for reducing the number of oxygen molecules in the sealed container to less than that in an atmospheric pressure environment.

[0012] Another aspect of the present disclosure is a deterioration test method for testing the deterioration of a sample, including a step of irradiating the sample held in a sealed container with light and a step of reducing the number of oxygen molecules in the sealed container to less than that in an atmospheric pressure environment.

Effects of the Invention

[0013] According to one aspect of the present invention, it is possible to perform a deterioration test of an object in an extreme environment such as the stratosphere.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a deterioration test apparatus 1 in a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an example of the configuration of a deterioration test apparatus 1 in a second embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of the configuration of a deterioration test apparatus 1A in a third embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing an example of the configuration of a deterioration test apparatus 1A in a fourth embodiment. [Figure 5] FIG. 5 is a view showing an example of the configuration of a deterioration test apparatus 1 in a fifth embodiment. [Figure 6] Figure 6 is a flowchart illustrating the procedure for testing the sample. [Figure 7] Figure 7 is a diagram illustrating the relationship between the wavelength of light and the amount of light used to illustrate an embodiment of the light source. [Figure 8] Figure 8 is another diagram illustrating the relationship between the wavelength of light, the amount of light, and the carbonyl index to illustrate an example of a real light source. [Modes for carrying out the invention]

[0015] The following describes a degradation testing apparatus, a degradation testing method, and a method for manufacturing a sample to which the present invention is applied, with reference to the drawings.

[0016] (First Embodiment) Figure 1 is a cross-sectional view showing an example of the configuration of the degradation testing apparatus 1 in the first embodiment. The degradation test apparatus 1 includes, for example, a sealed container 10, a sample holding unit 20, a light source unit 30, a concentration adjustment unit 40, a temperature adjustment unit 50, an ozone gas introduction unit 60, a humidity adjustment unit 70, a water spray unit 80, a drainage unit 90, and a control unit 100. The degradation testing apparatus 1 has a configuration that allows for a degradation testing method to test the degradation of a sample 12. In this embodiment, the sample 12 is a lightweight material such as plastic, resin, or polymer. The degradation testing apparatus 1 irradiates the sample 12, which is held in a sealed container 10, with light, thereby reducing the number of oxygen molecules in the sealed container 10 to less than the number of oxygen molecules in an atmospheric pressure environment. In the following explanation, the environment near the Earth's surface will be referred to as the atmospheric pressure environment, and extreme environments such as the atmosphere will be referred to as the high-altitude environment. The number of oxygen molecules is the number of oxygen molecules in one liter of volume, and the number of oxygen molecules in an atmospheric pressure environment is the number of oxygen molecules at standard atmospheric pressure. The number of oxygen molecules is calculated as follows: • Oxygen concentration: PO2 (%) Under atmospheric pressure: 20.9% • Container volume: V (L) Temperature: T(K) Under atmospheric pressure: 300K • Pressure: P (atm) At atmospheric pressure: 1 atm • Gas constant: R = 0.08205 L·atm / (K·mol) Avogadro's number: NA = 6.02 × 10²³ particles / mol In that case, From the ideal gas law PV=nRT, the number of moles n=PV / (RT), so the number of air molecules and oxygen molecules can be calculated using the following formulas, respectively. Number of air molecules = n × NA = NA × PV / (RT) Number of oxygen molecules = Number of air molecules × Oxygen concentration = (NA × PV / (RT)) × PO2 / 100 Also, under atmospheric pressure conditions, The number of moles n of air in 1L is, n = PV / (RT) = 0.040625 mol The number of air molecules in 1L is Number of air molecules = n × NA = 2.445 × 10^23 Therefore, the number of oxygen molecules under atmospheric pressure is Number of oxygen molecules = Number of air molecules × Oxygen concentration = (2.445 × 10^23 molecules) × 0.209 = 5.11 × 10^21 This is the result. The number of oxygen molecules can be controlled by controlling the pressure, temperature, and oxygen concentration (concentration adjustment unit) inside the sealed container.

[0017] The sealed container 10 is, for example, a container that can be depressurized. Furthermore, it is desirable that the sealed container 10 is configured to prevent ultraviolet light and high-intensity light emitted from the light source unit 30 from leaking out. The sealed container 10 has a storage section 10a for housing the sample holder 20, etc., and a lid 10b that closes the opening of the storage section 10a. The sealed container 10 has, for example, a removable upper lid 10b, and the lid 10b is removed from the storage section 10a when installing the sample 12. After installing the sample 12, the lid 10b is attached to the storage section 10a so that the inside becomes airtight, and is secured by tightening bolts or the like around each circumference. Various materials can be used for the sealed container 10 as long as they have pressure resistance against the pressure inside the container and resistance to ozone gas. For example, it can be made from SUS, aluminum alloy, iron, titanium alloy, tungsten alloy, etc., and these can be combined or covered with other materials.

[0018] The sample holding unit 20 includes, for example, a temperature control device 22, a stage 24, and a support unit 26. The sample 12 is fixed to the stage 24. The support unit 26 supports the stage 24 within the sealed container 10. The temperature control device 22 is built into the stage 24. The temperature control device 22 has a mechanism for heating or cooling the stage 24 in response to a control signal from the control unit 100. By heating or cooling the stage 24 with the temperature control device 22, the temperature of the sample 12 is increased or decreased.

[0019] The light source unit 30 incorporates a light source that emits light and includes an optical filter 30a that removes some wavelengths of light from the light source. The light source unit 30 only needs to include a light source that emits light including ultraviolet light in the UVC band, preferably a light source that emits light including wavelengths of 300 nm or less, and more preferably a light source that emits light with wavelengths of 300 nm or less at high intensity. The light source unit 30 may be, for example, a carbon arc, high-pressure mercury, xenon lamp, metal halide, etc., used in weather resistance testing, either alone or in combination of at least two different types of light sources. The light source unit 30 may also be an LED light source or a laser light source, and may be a combination of a carbon arc, high-pressure mercury, xenon lamp, metal halide, etc. However, it is preferable to use xenon, which has the wavelength closest to that of sunlight, as the light source unit 30.

[0020] Furthermore, the light emitted from the light source 30 preferably includes light with a wavelength of 290 nm or less, and more preferably includes some light in the wavelength range of 290 nm to 390 nm. The spectral shape of the light emitted from the light source 30 is preferably close to the spectral shape of sunlight. In addition, although light with wavelengths longer than 390 nm emitted from the light source 30 does not directly cause degradation of the sample 12, light with wavelengths in the infrared region in particular may be left in because it has an effect such as heating the sample 12. On the other hand, since the temperature of the sample 12 is controlled by a temperature control device 22, etc., infrared light with a wavelength greater than 390 nm may be cut off to eliminate the effect of heating by light.

[0021] The concentration adjustment unit 40 includes, for example, a gas inlet pipe 42, a humidifier 44, an ozone concentration meter 46, a pressure regulator 47, an ozone trap 48, and an exhaust pipe 49. The concentration adjustment unit 40 introduces gas humidified by the humidifier 44 into the sealed container 10 via the gas inlet pipe 42. The concentration adjustment unit 40 also adjusts the pressure using the pressure regulator 47 and exhausts the gas in the sealed container 10 via the exhaust pipe 49. The concentration adjustment unit 40 may control the oxygen concentration by introducing an inert gas into the sealed container 10, or it may control the oxygen concentration by reducing the pressure inside the sealed container 10.

[0022] Since the degradation test in this embodiment assumes a high-altitude environment, it is preferable that the number of oxygen molecules in the sealed container 10 be less than the number of oxygen molecules in an atmospheric pressure environment near the Earth's surface, and that the number of nitrogen molecules in the sealed container 10 be increased. The concentration adjustment unit 40 may control the number of oxygen molecules in the sealed container 10 to be 5.11 × 10^21 or less. Furthermore, since the concentration of ozone gas in a high-altitude environment is higher than that in an atmospheric pressure environment near the Earth's surface, it is preferable to keep the ozone gas concentration in the sealed container 10 high. Extreme environments such as high-altitude environments have lower pressure than atmospheric pressure environments near the Earth's surface, so it is preferable to keep the pressure in the sealed container 10 below atmospheric pressure.

[0023] The temperature adjustment unit 50 adjusts the temperature of the sample 12 by adjusting the temperature of the sample holding unit 20. The temperature adjustment unit 50 adjusts the temperature of the sample holding unit 20 to a predetermined low temperature and changes the temperature of the adjusted sample holding unit 20. The temperature control unit 50 includes, for example, a temperature controller 52, a temperature control pump 54, and piping 56. The temperature control unit 50 introduces the gas in the sealed container 10 to the temperature controller 52 via the temperature control pump 54 and piping 56, adjusts the temperature of the gas using the temperature controller 52, and returns the temperature-adjusted gas to the sealed container 10.

[0024] At high altitudes, temperatures drop to minus tens of degrees Celsius. However, during the day, when sunlight is shining on sample 12, although the ambient temperature remains low, sunlight is less absorbed and reflected by air and moisture, resulting in a higher intensity of light irradiating sample 12 compared to the atmospheric pressure environment near the Earth's surface. Consequently, sample 12 is heated by sunlight and reaches high temperatures (tens of degrees Celsius, and in some materials, over 100 degrees Celsius). On the other hand, at night, sunlight does not irradiate sample 12, so there is no effect of heat from sunlight, and the temperature of sample 12 becomes approximately the same as the ambient temperature, resulting in a temperature of minus tens of degrees Celsius.

[0025] Thus, in a high-altitude environment, the temperature difference between when the sample 12 is exposed to sunlight and when it is not is significantly larger compared to the atmospheric pressure environment near the Earth's surface. To reproduce such temperature changes, the temperature control unit 50 raises the temperature of the sample 12 when it is exposed to light and lowers the temperature of the sample 12 when it is not exposed to light.

[0026] The ozone gas introduction unit 60 includes, for example, an ozone gas introduction pipe 62 and an ozone gas generator 64. The ozone gas introduction unit 60 generates ozone gas using the ozone gas generator 64 and introduces the generated ozone gas into the sealed container 10 via the ozone gas introduction pipe 62.

[0027] The number of oxygen molecules in the atmospheric pressure environment near the Earth's surface is approximately 5.11 × 10^21, but the number of oxygen molecules decreases with increasing altitude. Furthermore, in high-altitude environments, short-wavelength light called UVC, which does not normally reach the Earth's surface, is present, causing oxygen to decompose and ozone to be produced. Ozone is hardly produced near the Earth's surface, at around 0.005 ppm, but it rises to 10-20 ppm in high-altitude environments (stratosphere). Ozone contributes significantly to the degradation of materials, especially organic matter. Therefore, the degradation of sample 12 is accelerated in high-altitude environments compared to atmospheric pressure environments near the Earth's surface. To address this, the ozone gas introduction unit 60 controls the ozone concentration according to the high-altitude environment in order to conduct degradation tests in high-altitude environments.

[0028] The humidity control unit 70 includes, for example, piping 72, a humidity controller 74, and a pump 76. The humidity control unit 70 introduces the gas in the sealed container 10 to the humidity controller 74 via the pump 76 and piping 72, adjusts the humidity of the gas using the humidity controller 74, and returns the humidified gas to the sealed container 10.

[0029] The water spray unit 80 includes, for example, a water spray pipe 82 and a water flow rate adjustment unit 84. When spraying water onto the sample 12, the water spray unit 80 adjusts the amount of water supplied from the water spray pipe 82 using the water flow rate adjustment unit 84 and sprays water onto the sample 12.

[0030] In extreme environments such as high altitudes, rain does not fall, so the water spray unit 80 is not necessary. However, because the temperature is low, moisture may freeze and form tiny ice particles. These ice particles may adhere to the surface of the sample 12, or moisture or water droplets that adhere to the sample 12 in an atmospheric pressure environment near the ground may freeze in extreme environments such as high altitudes. Anticipating such situations, the degradation test apparatus 1 can perform humidification or water spraying.

[0031] The drainage unit 90 includes, for example, a drainage tank 92, an on / off valve 94, a drainage pipe 96, and an ozone trap 98. The drainage unit 90 collects water droplets in the sealed container 10 in the drainage tank 92 and drains them through the drainage pipe 96 and ozone trap 98 by opening the on / off valve 94.

[0032] The degradation test apparatus 1 further includes an oxygen concentration meter 110, a pressure gauge 112, and a thermometer 114. The oxygen concentration meter 110 detects the oxygen concentration inside the sealed container 10. The pressure gauge 112 detects the gas pressure inside the sealed container 10. The thermometer 114 detects the temperature inside the sealed container 10.

[0033] The control unit 100 is a processing circuit that controls each part of the degradation test apparatus 1. The control unit 100 receives sensor signals indicating sensor values ​​detected by the oxygen concentration meter 110, pressure gauge 112, thermometer 114, and ozone concentration meter 46, and outputs control signals that control the operation of the temperature control device 22, light source unit 30, concentration adjustment unit 40, temperature adjustment unit 50, ozone gas introduction unit 60, humidity adjustment unit 70, water spray unit 80, and drainage unit 90. The control unit 100 sets set values ​​for temperature, pressure, oxygen concentration, humidity, and ozone concentration inside the sealed container 10. The control unit 100 monitors the sensor values ​​of the oxygen concentration meter 110, pressure gauge 112, thermometer 114, and ozone concentration meter 46, and controls the light and temperature adjustment device 22, light source unit 30, concentration adjustment unit 40, temperature adjustment unit 50, ozone gas introduction unit 60, humidity adjustment unit 70, water spray unit 80, and drainage unit 90 to achieve the respective set values.

[0034] The control unit 100, with the sample 12 held on the sample holding section 20 inside the sealed container 10, operates the pressure regulator 47 while introducing a gas such as oxygen or nitrogen through the gas introduction pipe 42 to adjust the internal pressure inside the sealed container 10 to a predetermined level. The control unit 100 then generates ozone gas in the ozone gas generator 64 and introduces the ozone gas into the sealed container 10 through the ozone gas introduction pipe 62. In this state, the control unit 100 irradiates the sample 12 with light from the light source unit 30, which simulates sunlight, and further adjusts the temperature inside the sealed container 10 to a predetermined level using the temperature regulator 52. Furthermore, it heats and cools the sample 12 using the temperature control device 22 installed inside the sample holding section 20 to maintain the sample 12 at the predetermined level. The control unit 100 may also humidify the gas introduced from the gas introduction pipe 42 using the humidity regulator 74. By leaving sample 12 in such an environment for a predetermined period, it is possible to test how quickly sample 12 deteriorates due to light such as sunlight, heat, ozone gas, etc.

[0035] During periods when daytime is assumed, the control unit 100 controls the light source unit 30 to irradiate the sample 12 with light containing short wavelengths of 290 nm or less that do not reach the Earth's surface, and controls the temperature control device 22 and temperature control unit 50 so that the temperature of the sample 12 becomes high during light irradiation, thereby bringing the sample 12 to the desired temperature. Furthermore, the control unit 100 reads the pressure, temperature, and oxygen concentration, calculates the number of oxygen molecules using the oxygen molecule number calculation formula described above, and controls the concentration adjustment unit 40 so that the number of oxygen molecules in the sealed container 10 is lower than that of the atmospheric pressure environment near the Earth's surface, and the pressure inside the sealed container 10 is lower than that of the atmospheric pressure environment. In addition, the control unit 100 controls the ozone gas introduction unit 60 so that the ozone gas concentration inside the sealed container 10 is higher than that of the atmospheric pressure environment.

[0036] The control unit 100 controls the light source unit 30 so as not to irradiate the sample 12 with light during periods when nighttime is assumed. During periods when light is not irradiated, the temperature will be low in extreme environments such as high altitude environments, so the control unit 100 controls the temperature control device 22 and the temperature control unit 50 so that the sample 12 is at a low temperature. At this time, the control unit 100 may control the pressure, oxygen concentration, and ozone gas concentration inside the sealed container 10 in the same way as during light irradiation, or may change them as appropriate.

[0037] The control unit 100 can perform degradation tests that simulate extreme environments such as high-altitude environments by repeatedly switching between light-irradiated and non-light-irradiated states. The control unit 100 may control the water spray unit 80 to spray water between the light-irradiated state and the non-light-irradiated state, or it may control the water spray unit 80 to spray water at any timing in either the light-irradiated state or the non-light-irradiated state.

[0038] The control unit 100 may gradually decrease the number of oxygen molecules from the atmospheric pressure environment as the assumed altitude (assumed altitude) during the test gradually increases, or gradually increase the number of oxygen molecules from a number lower than that in the atmospheric pressure environment as the assumed altitude gradually decreases. In addition, the temperature control device 22 and temperature control unit 50 that adjust the temperature of the sample holding unit 20 may gradually decrease the temperature of the sample holding unit 20 as the number of oxygen molecules gradually decreases, or gradually increase the temperature of the sample holding unit 20 as the number of oxygen molecules gradually increases. Furthermore, the water spray unit 80 may apply water to the sample 12 in accordance with the gradually increasing assumed altitude, or in accordance with the gradually decreasing assumed altitude.

[0039] When the control unit 100 is conducting a test in which the sample 12 moves from an atmospheric pressure environment to a high-altitude environment, it controls the light source unit 30 to gradually increase the intensity of light that includes short wavelengths of 290 nm or less that do not reach the ground, controls the temperature control device 22 and temperature control unit 50 to gradually lower the temperature of the sample 12, controls the concentration control unit 40 to gradually decrease the number of oxygen molecules, and controls the ozone gas introduction unit 60 to introduce ozone gas when the sample moves to a high-altitude environment. Furthermore, when the control unit 100 is testing the sample 12 passing through clouds when moving from an atmospheric pressure environment to a high-altitude environment, it controls the water spray unit 80 to cause water droplets to adhere to the sample 12.

[0040] When the control unit 100 is conducting a test in which the sample 12 moves from a high-altitude environment to an atmospheric pressure environment, it controls the light source unit 30 to gradually decrease the intensity of light including short-wavelength light of 290 nm or less that does not reach the ground, controls the temperature control device 22 and temperature control unit 50 to gradually increase the temperature of the sample 12, controls the concentration control unit 40 to gradually increase the number of oxygen molecules, and controls the ozone gas introduction unit 60 to stop the introduction of ozone gas. Furthermore, when the control unit 100 is testing the passage through clouds when moving from a high-altitude environment to an atmospheric pressure environment, it controls the water spray unit 80 to cause water droplets to adhere to the sample 12.

[0041] As described above, according to the embodiment, a degradation test apparatus 1 for testing the degradation of a sample 12 can be realized, comprising a sealed container 10, a sample holding unit 20 for holding the sample 12 inside the sealed container 10, a light source unit 30 for irradiating the sample 12 with light, and a concentration adjustment unit 40 for lowering the oxygen concentration inside the sealed container 10 to a level lower than the oxygen concentration in an atmospheric pressure environment. With this degradation test apparatus 1, degradation tests of objects can be performed in extreme environments such as the stratosphere.

[0042] (Second Embodiment) Figure 2 is a cross-sectional view showing an example of the configuration of the degradation testing apparatus 1 in the second embodiment. The degradation test apparatus 1 of the second embodiment differs from the degradation test apparatus 1 of the first embodiment in that the ozone gas introduction section is an ozone gas generating light source 66 located inside the sealed container 10. The ozone gas generating light source 66 generates ozone from oxygen inside the sealed container 10 by irradiating it with ultraviolet light. The control unit 100 can adjust the number of oxygen molecules and the ozone concentration inside the sealed container 10 by controlling the ozone gas generating light source 66 based on sensor values ​​detected by the oxygen concentration meter 110 and the ozone concentration meter 46.

[0043] (Third embodiment) Figure 3 is a cross-sectional view showing an example of the configuration of the degradation test apparatus 1A in the third embodiment. The degradation test apparatus 1A of the third embodiment has a configuration that follows that of an existing xenon weather meter. The degradation test apparatus 1A has a configuration in which a transparent tube 34 is inserted approximately in the center of a sealed container 10A. The transparent tube 34 is made of quartz glass. A light source unit 30A is placed inside the transparent tube 34.

[0044] The sample holding unit 20A is equipped with a sample holding rotating stand 28. The sample holding rotating stand 28 is configured to fix multiple samples 12 around a transparent tube 34. The sample holding rotating stand 28 has a mechanism to rotate the fixed multiple samples 12 around the transparent tube 34 as the central axis. A thermometer 114 is attached to the sample holding unit 20A. The water spray unit 80A is configured to spray water onto the multiple samples 12 held in the sample holding unit 20A.

[0045] The control unit 100A is configured to receive set values ​​for temperature, pressure, oxygen concentration, humidity, and ozone concentration inside the sealed container 10A. The control unit 100A monitors the sensor values ​​of the oxygen concentration meter 110, pressure gauge 112, thermometer 114, hygrometer 116, and ozone concentration meter 46, and controls the light source unit 30A, concentration adjustment unit 40, temperature adjustment unit 50, ozone gas introduction unit 60, humidity adjustment unit 70, water spray unit 80A, and drainage unit 90 to achieve the respective set values.

[0046] (Fourth embodiment) Figure 4 is a cross-sectional view showing an example of the configuration of the degradation test apparatus 1A in the fourth embodiment. The degradation test apparatus 1A of the fourth embodiment differs from the degradation test apparatus 1A of the third embodiment in that the ozone gas introduction section is an ozone gas generating light source 66 located inside the sealed container 10A. The ozone gas generating light source 66 generates ozone from oxygen inside the sealed container 10A by irradiating it with ultraviolet light. The control unit 100A can adjust the oxygen concentration and ozone concentration inside the sealed container 10A by controlling the ozone gas generating light source 66 based on sensor values ​​detected by the oxygen concentration meter 110 and the ozone concentration meter 46.

[0047] (Fifth embodiment) Figure 5 shows an example of the configuration of the degradation test apparatus 1 in the fifth embodiment. The degradation test apparatus 1 includes, for example, a sealed container 10, a sample holding unit 20, a light source unit 30, a concentration adjustment unit 40, a temperature adjustment unit 50, an ozone gas introduction unit 60, a humidity adjustment unit 70, a water spray unit 80, a drainage unit 90, a control unit 100, and a calculation unit 101. The degradation test apparatus 1 in the fifth embodiment, like the degradation test apparatus 1 described in the first embodiment, can perform degradation tests on the sample 12, particularly under high-altitude conditions. The sample 12 may be a lightweight plastic, resin, polymer, etc., as in the first embodiment. The sample 12 may be a laminated sheet, in particular, which requires degradation testing in the stratosphere, a high-altitude environment.

[0048] The sealed container 10 is, for example, a sealed container that can be depressurized. The sealed container 10 is sealed so that the light emitted from the light source unit 30 does not leak out. The sealed container 10 has a storage section 10a and a lid 10b. The storage section 10a is a box-shaped container with an opening, in which a sample 12 can be stored. The lid 10b is configured to be removable from the opening of the storage section 10a and is removed from the storage section 10a when storing the sample 12 in the storage section 10a. After the sample 12 is placed in the storage section 10a, the lid 10b is attached to the storage section 10a so that the inside of the storage section 10a becomes airtight. Then, for example, each outer circumference of the lid 10b is fastened and secured with bolts or the like. Various materials can be used for the sealed container 10 that have pressure resistance against the pressure inside the container and resistance to ozone gas. Examples of materials that can be used for the sealed container 10 include SUS, aluminum alloy, iron, titanium alloy, and tungsten alloy. These materials may be used in combination as the materials for the sealed container 10, or these materials may be covered with other materials.

[0049] The sample holding section 20 is provided in the storage section 10a. The sample holding section 20 comprises, for example, a temperature control device 22, a stage 24, and a support section 26. The sample 12 is fixed to the stage 24. The support section 26 supports the stage 24 within the storage section 10a of the sealed container 10. The temperature control device 22 may be built into the stage 24. The temperature control device 22 includes a mechanism for heating or cooling the stage 24 in response to a control signal from the control unit 100. By heating or cooling the stage 24 with the temperature control device 22, the temperature of the sample 12 is increased or decreased.

[0050] The light source unit 30 incorporates a light source that emits light and includes an optical filter 30a that removes some wavelengths of light from the light source. The light source unit 30 only needs to include a light source that emits light including ultraviolet light in the UVC band (100 nm to 280 nm). The light source unit 30 may also include a light source that emits light including wavelengths of 100 nm to 400 nm. Furthermore, in degradation tests simulating high-altitude environments, the optical filter 30a may cut out infrared light with a wavelength greater than 390 nm. The light source unit 30 may include a light source that uses, for example, a carbon arc lamp, high-pressure mercury lamp, xenon lamp, or metal halide lamp used in weather resistance tests, either alone or in combination of at least two different types of light sources. The light source of the light source unit 30 may also be an LED light source or a laser light source. LED light sources and laser light sources may be used in combination with carbon arc lamps, high-pressure mercury lamps, xenon lamps, metal halide lamps, etc. However, it is preferable to use a xenon lamp as the light source unit 30, which can emit light that is closest to the waveform (spectral distribution) of sunlight. When multiple light sources are used in combination, the waveform of sunlight at the actual assumed altitude may be measured in advance, and a combination of light sources that reproduces that waveform may be used. It is desirable that the matching rate between the waveforms of light generated by multiple light sources and the waveform of sunlight at the actual assumed altitude in the 290nm to 390nm wavelength band be 70% or more. The waveform of sunlight may be measured by flying a balloon for waveform observation to the assumed altitude. Alternatively, the waveform of sunlight at the actual assumed altitude may be obtained by using, for example, a solar spectrum simulation provided by the National Renewable Energy Laboratory (NREL) without measuring the waveform of sunlight.

[0051] The concentration adjustment unit 40 includes, for example, a gas inlet pipe 42, a humidifier 44, an ozone concentration meter 46, a pressure regulator 47, an ozone trap 48, and an exhaust pipe 49. The concentration adjustment unit 40 introduces gas humidified by the humidifier 44 into the sealed container 10 via the gas inlet pipe 42. The concentration adjustment unit 40 also adjusts the pressure using the pressure regulator 47 and exhausts the gas in the sealed container 10 via the exhaust pipe 49. The concentration adjustment unit 40 may control the number of oxygen molecules by introducing an inert gas into the sealed container 10, or by reducing the pressure inside the sealed container 10.

[0052] The temperature control unit 50 adjusts the temperature of the sample 12 by adjusting the temperature of the sample holding unit 20. The temperature control unit 50 adjusts the temperature of the sample holding unit 20 to a predetermined low temperature and changes the temperature of the adjusted sample holding unit 20. The temperature control unit 50 includes, for example, a temperature controller 52, a temperature control pump 54, and piping 56. The temperature control unit 50 introduces the gas in the sealed container 10 to the temperature controller 52 via the temperature control pump 54 and piping 56, adjusts the temperature of the gas using the temperature controller 52, and returns the temperature-adjusted gas to the sealed container 10.

[0053] The ozone gas introduction unit 60 includes, for example, an ozone gas introduction pipe 62 and an ozone gas generator 64. The ozone gas introduction unit 60 generates ozone gas using the ozone gas generator 64 and introduces the generated ozone gas into the sealed container 10 via the ozone gas introduction pipe 62.

[0054] The humidity control unit 70 includes, for example, piping 72, a humidity controller 74, and a pump 76. The humidity control unit 70 introduces the gas in the sealed container 10 to the humidity controller 74 via the pump 76 and piping 72, adjusts the humidity of the gas using the humidity controller 74, and returns the humidified gas to the sealed container 10.

[0055] The water spray unit 80 includes, for example, a water spray pipe 82 and a water flow rate adjustment unit 84. When spraying water onto the sample 12, the water spray unit 80 adjusts the amount of water supplied from the water spray pipe 82 using the water flow rate adjustment unit 84 and sprays water onto the sample 12.

[0056] The drainage unit 90 includes, for example, a drainage tank 92, an on / off valve 94, a drainage pipe 96, and an ozone trap 98. The drainage unit 90 collects water droplets in the sealed container 10 in the drainage tank 92 and drains them through the drainage pipe 96 and ozone trap 98 by opening the on / off valve 94.

[0057] The degradation test apparatus 1 further includes an oxygen concentration meter 110, a pressure gauge 112, and a thermometer 114. The oxygen concentration meter 110 detects the oxygen concentration inside the sealed container 10. The pressure gauge 112 detects the gas pressure inside the sealed container 10. The thermometer 114 detects the temperature inside the sealed container 10.

[0058] The control unit 100 controls each part of the degradation test apparatus 1. The control unit 100 receives sensor signals indicating sensor values ​​detected by the oxygen concentration meter 110, pressure gauge 112, thermometer 114, and ozone concentration meter 46, and outputs control signals that control the operation of the temperature control device 22, light source unit 30, concentration adjustment unit 40, temperature adjustment unit 50, ozone gas introduction unit 60, humidity adjustment unit 70, water spray unit 80, and drainage unit 90. The control unit 100 may be composed of a computer equipped with a processor and memory. The computer may be a personal computer or the like. The control unit 100 is configured to receive set values ​​for temperature, pressure, oxygen molecule count, humidity, and ozone concentration inside the sealed container 10. The control unit 100 monitors the sensor values ​​of the oxygen concentration meter 110, pressure gauge 112, thermometer 114, and ozone concentration meter 46, and controls the light and temperature adjustment device 22, light source unit 30, concentration adjustment unit 40, temperature adjustment unit 50, ozone gas introduction unit 60, humidity adjustment unit 70, water spray unit 80, and drainage unit 90 to achieve the respective set values.

[0059] The calculation unit 101 calculates set values ​​for control in the control unit 100. The calculation unit 101 calculates at least the set values ​​for the number of oxygen molecules and the ozone concentration. The calculation unit 101 may be composed of a computer equipped with a processor and memory. The computer may be a personal computer or the like. The calculation unit 101 includes an input unit 102. The input unit 102 accepts input of conditions used in calculating the set values. The input unit 102 may be equipped with various input devices such as a keyboard, mouse, and touch panel, and a display for displaying a user interface (UI). The calculation unit 101 may also be integrated with the control unit 100.

[0060] The operation of the degradation testing apparatus 1 in the fifth embodiment will be described below. First, an overview of the degradation test performed by the degradation testing apparatus 1 will be explained.

[0061] Degradation of sample 12 due to light such as sunlight occurs when light irradiated onto sample 12 breaks the elemental bonds of sample 12. The strength of the elemental bonds varies depending on the type of elements used in sample 12, the structure of sample 12, etc. For elemental bond breaking to occur due to light, light with a wavelength appropriate to the strength of each elemental bond must be irradiated onto sample 12. In degradation tests under high-altitude environments, it is necessary to reproduce this degradation of sample 12 due to irradiation with sunlight. Furthermore, in order to accelerate degradation in order to obtain the results of the light degradation test early, it is desirable to irradiate sample 12 with light of a wavelength appropriate to the strength of each elemental bond at a higher light intensity than sunlight.

[0062] The amount of light irradiated onto sample 12 may be determined based on the amount of light at a specific wavelength. This specific wavelength could be, for example, 365 nm. The "amount of light" irradiated onto sample 12 may be a value measured using a light intensity measurement device, such as the UIT-250 manufactured by Ushio Inc., and a separate light receiver, such as the UVD-S365 manufactured by Ushio Inc. Alternatively, the amount of light irradiated onto sample 12 may be determined based on the integrated light intensity, which is the integral value between any two wavelengths. Specifically, the amount of light irradiated onto sample 12 may be determined by measuring the amount of light at each wavelength included in the wavelength band centered on 365 nm using the aforementioned measuring device and integrating these amounts. Here, the actual amount of sunlight can fluctuate with the seasons. To reproduce such seasonal fluctuations, the amount of light irradiated onto sample 12 may also be determined from a range of light intensity within a certain range. For example, the amount of light actually irradiated onto sample 12 may be determined, for instance, by the season, from a range of ±30% of the amount of light determined based on the amount of light of a specific wavelength or the amount of light determined based on the integrated amount of light.

[0063] As described in the first to fourth embodiments, the degradation test in the fifth embodiment also assumes a high-altitude environment. Since the number of oxygen molecules at high altitudes is less than at ground level, it is desirable that the number of oxygen molecules be lower than the number of oxygen molecules at ground level in degradation tests under high-altitude conditions. It is preferable that the number of oxygen molecules inside the sealed container 10 be lower than the number of oxygen molecules in the atmospheric pressure environment near the ground, and it is preferable to increase the number of nitrogen molecules inside the sealed container 10. For example, when reproducing the environment at an altitude of 20 km above ground level, the concentration adjustment unit 40 may control the number of oxygen molecules inside the sealed container 10 to 1 / 16 or less of that at ground level.

[0064] Furthermore, in order to induce the same degradation in sample 12 as in a real environment, it is desirable not only to increase the light intensity irradiated onto sample 12, but also to change the number of oxygen molecules in the atmosphere in which sample 12 is placed according to the light intensity. This is to reproduce degradation by photo-oxidation, in which oxygen binds to areas that have been cut by light. As the light intensity increases, the number of areas that are cut increases, so unless the number of oxygen molecules is increased accordingly, degradation by photo-oxidation will not be reproduced correctly. A preferable number of oxygen molecules relative to the light intensity may be, for example, on the ground, the number of oxygen molecules at the same ratio as the ratio of the light intensity irradiated onto sample 12 to the actual sunlight intensity. For example, if the light intensity irradiated onto sample 12 is doubled, it is preferable to double the number of oxygen molecules as well. On the other hand, in high-altitude environments, as mentioned above, the number of oxygen molecules is lower than on the ground, so if the light intensity irradiated onto sample 12 is doubled, it is preferable to make the number of oxygen molecules less than double.

[0065] Furthermore, the number of oxygen molecules in the atmospheric pressure environment near the Earth's surface is approximately 5.11 × 10^21, but the number of oxygen molecules decreases with increasing altitude. In addition, short-wavelength light called UVC, which does not normally reach the Earth's surface, is present in high-altitude environments, causing oxygen to decompose and ozone to be produced. The concentration of ozone gas in high-altitude environments is higher than in the atmospheric pressure environment near the Earth's surface. For example, in Japan, the ozone concentration at ground level is 0.01 to 0.05 ppm, while the ozone concentration at an altitude of 10 km is 0.1 to 0.5 ppm, and at an altitude of 20 km it is 5 to 8 ppm. Therefore, in degradation tests simulating high-altitude environments, it is preferable to keep the ozone gas concentration in the sealed container 10 high. Also, since extreme environments such as high-altitude environments have lower pressure than atmospheric pressure environments near the Earth's surface, it is preferable to keep the pressure inside the sealed container 10 below atmospheric pressure. Furthermore, if the ozone concentration is high, the degradation of the sample 12 due to ozone becomes significant. In other words, under high-altitude conditions, sample 12 undergoes degradation due to photo-oxidation and ozone, as well as degradation due to the interaction between photo-oxidation and ozone. Furthermore, if the amount of light irradiated onto sample 12 increases, the ozone concentration must be increased accordingly to properly reproduce the degradation due to interaction with photo-oxidation. A preferred ozone concentration relative to the amount of light is, for example, on the ground, the ozone concentration may be the same ratio as the amount of light irradiated onto sample 12 relative to the actual amount of sunlight. For example, if the amount of light irradiated onto sample 12 is doubled, it is preferable to double the ozone concentration as well. On the other hand, under high-altitude conditions, if the amount of light irradiated onto sample 12 is doubled, it is preferable to increase the ozone concentration by more than double.

[0066] Furthermore, at high altitudes, the temperature drops to minus tens of degrees Celsius. However, during the day, when sunlight is irradiating the sample 12, although the ambient temperature remains low, sunlight is less absorbed and reflected by air and moisture, so a higher amount of light is irradiated onto the sample 12 compared to the atmospheric pressure environment near the Earth's surface. As a result, the sample 12 is heated by sunlight and becomes hot. On the other hand, at night, sunlight does not irradiate the sample 12, so there is no effect of heat from sunlight, and the temperature becomes almost the same as the ambient temperature, so the temperature of the sample 12 becomes minus tens of degrees Celsius. Thus, at high altitudes, there is a very large temperature difference between the state in which the sample 12 is irradiated by sunlight and the state in which the sample 12 is not irradiated by sunlight, compared to the atmospheric pressure environment near the Earth's surface. To reproduce such temperature changes, the temperature control unit 50 raises the temperature of the sample 12 when it is irradiated with light and lowers the temperature of the sample 12 when it is not irradiated with light.

[0067] In extreme environments such as high altitudes, rain does not fall, so the water spray unit 80 is not necessary. However, because the temperature is low, moisture may freeze and form tiny ice particles. These ice particles may adhere to the surface of the sample 12, or moisture or water droplets that adhere to the sample 12 in an atmospheric pressure environment near the ground may freeze in extreme environments such as high altitudes. Anticipating such situations, the degradation test apparatus 1 can perform humidification or water spraying.

[0068] In degradation testing, the sample 12 can be placed in a sealed container 10 in which the irradiation light intensity, oxygen molecule count, ozone concentration, temperature, pressure, and moisture content are controlled at the assumed altitudes described above, thereby enabling degradation testing of the sample 12.

[0069] Figure 6 is a flowchart illustrating the operation of a test using the degradation testing apparatus 1. The operation shown in Figure 6 is performed through the cooperation of the calculation unit 101 and the control unit 100. The operation of the test shown in Figure 6 may also be incorporated into the manufacturing process of the sample 12.

[0070] In step S1, the arithmetic unit 101 receives an input via the input unit 102. The input includes the assumed altitude [km] of the degradation test. The input also includes a magnification factor for the amount of light irradiated to the sample 12. Furthermore, the input includes an input of the assumed time of the degradation test. The assumed time may be input in time zones such as day or night, or may be input by time. Furthermore, the assumed time may be input including units of year, month, and day. Furthermore, the input includes the presence or absence of water spray.

[0071] In step S2, the arithmetic unit 101 determines the amount of light of the light source unit 3 irradiated to the sample 12 based on the input in step S1. The arithmetic unit 101 sets the waveform of the light emitted from the light source unit 3 to be similar to the waveform of sunlight at the altitude of the assumed altitude. Then, the arithmetic unit 101 determines the amount of light of the light source unit 3 according to the magnification factor in which the set light is input. The amount of light A irradiated to the sample 12 can be determined by multiplying, for example, the amount of light A determined based on a specific wavelength λ by a magnification factor n (n≧1). Here, A λ can be determined by multiplying by a magnification factor n (n≧1). Here, A λ is the amount of 365 nm light irradiated from the light source unit 30 measured using UIT-250 and UVD-S365 manufactured byUSHIO DENKI CO., LTD. 365 [mW / cm 2 . Here, when nA λ is larger than the amount of light of the wavelength λ of sunlight to be irradiated in the environment at the assumed altitude x [km], for example, the amount of 365 nm light, acceleration of degradation is expected. Measurement of the amount of light of the wavelength λ of sunlight at the altitude x [km] may be performed using the same measuring device as the measurement of the amount of light of the light source unit 30. Also, the amount of light determined in step S2 may be determined based on the integrated light amount.

[0072] In step S3, the arithmetic unit 101 determines the number of oxygen molecules and the ozone concentration. When the arithmetic unit 101 sets the amount of light of the wavelength λ of sunlight at the altitude x [km] to A x [mW / cm 2 and the number of oxygen molecules in the sealed container 10 to y [pieces] with the number of oxygen molecules at the altitude x [km] being B [pieces], y≦nB(A λ / A xThe calculation unit 101 may determine the number of oxygen molecules at an altitude of x [km] from the pressure, temperature, and oxygen concentration using the oxygen molecule number calculation formula described above. Alternatively, the calculation unit 101 may obtain the number of oxygen molecules calculated by the control unit 100. The lower limit of the number of oxygen molecules y may be 0 [units]. Similarly, when the ozone concentration at an altitude of x [km] is C [%], the calculation unit 101 determines the ozone concentration z [%] of the sealed container 10 to be z ≥ nC (A λ / A x The following can be determined to satisfy the conditions. The upper limit of the ozone concentration z does not need to be set, but from a safety standpoint it is preferable that it be 1% or less. Here, A λ and A x Each of these is the amount of light I, determined based on the integrated light quantity. λ , I x Therefore, the number of oxygen molecules and the ozone concentration can be determined based on the integrated light intensity.

[0073] Assuming the number of oxygen molecules y is y > nB(A) λ / A x ) and the ozone concentration z is z <nC(A λ / A x When this is the case, the inside of the sealed container 10 has an excess of oxygen molecules and a deficiency of ozone compared to the actual light intensity, oxygen molecule count, and ozone concentration conditions in the environment at an altitude of x [km]. In this case, degradation by photo-oxidation becomes dominant. This is an environment similar to that on the ground, and results in degradation that is different from the degradation of sample 12 in the environment at an altitude of x [km]. As a result, predictions of the lifetime of sample 12 will also yield incorrect results.

[0074] Also, if the number of oxygen molecules y is y > nB(A λ / A x ) and the ozone concentration z is z≧nC(A λ / A xWhen this is the case, the amount of oxygen molecules in the sealed container 10 is excessive compared to the light intensity, number of oxygen molecules, and ozone concentration conditions in the actual environment at an altitude of x [km]. In this case, although degradation due to ozone is predominant, photodegradation due to oxygen also occurs. As a result, degradation occurs that is different from the degradation of sample 12 in the environment at an altitude of x [km]. This leads to incorrect predictions of the lifetime of sample 12, etc.

[0075] Also, the number of oxygen molecules y is y ≤ nB(A λ / A x ) and the ozone concentration z is z <nC(A λ / A x When this is the case, the amount of ozone inside the sealed container 10 is insufficient compared to the light intensity, oxygen molecule count, and ozone concentration conditions in the actual environment at an altitude of x [km]. In this case, although degradation due to ozone is predominant, the time until degradation occurs is prolonged.

[0076] In relation to the above, the number of oxygen molecules y is y ≤ nB(A λ / A x ) and the ozone concentration z is z≧nC(A λ / A x When this is the case, the conditions inside the sealed container 10 are appropriate for the light intensity, oxygen molecule count, and ozone concentration in the actual environment at an altitude of x [km]. In this case, it is expected that the degradation of the sample 12 will be in accordance with the conditions at an altitude of x [km]. This is expected to allow for accurate prediction of the sample 12's lifetime.

[0077] In step S4, the calculation unit 101 determines setting values ​​related to other test conditions such as temperature, pressure, and whether or not water spraying is performed. The calculation unit 101 may determine the temperature setting value for the sample 12 based on the input assumed altitude x [km] and time of day. The calculation unit 101 may also determine the pressure setting value for the sealed container 10 based on the input assumed altitude x [km]. Furthermore, upon receiving input indicating that water spraying should be performed, the calculation unit 101 may determine a setting value indicating that water spraying should be performed.

[0078] In step S5, the calculation unit 101 sends the determined setting values ​​to the control unit 100. The control unit 100 performs a degradation test on the sample 12 based on the setting values ​​received from the calculation unit 101. The control unit 100 irradiates the sample 12 with light having a waveform corresponding to the assumed altitude at a light intensity corresponding to the setting value from the light source unit 30. The control unit 100 also monitors the sensor values ​​of the oxygen concentration meter 110, pressure gauge 112, thermometer 114, and ozone concentration meter 46, and controls the temperature adjustment device 22, concentration adjustment unit 40, temperature adjustment unit 50, ozone gas introduction unit 60, humidity adjustment unit 70, water spray unit 80, and drainage unit 90 so that each sensor value becomes the setting value.

[0079] In step S6, after the degradation test has been conducted, sample 12 is evaluated. After the evaluation, the operation shown in Figure 6 is completed. If sample 12 is a paint, the evaluation of quality may be based on changes in color and gloss. If sample 12 is a film or molded body made of resin, polymer, etc., in addition to changes in color and gloss, the evaluation of quality may also be based on the presence or absence of cracks and delamination. Furthermore, the evaluation of quality may also be based on changes in physical properties such as the strength of sample 12, or changes in the structure of the materials constituting sample 12. The evaluation of quality based on changes in physical properties may be performed by determining whether the amount of change in each physical property from before the degradation test is within an arbitrarily set threshold, or whether the value of each physical property after the degradation test exceeds an arbitrarily set threshold. Changes in physical properties may be measured by Martens hardness tests, tensile tests, MSE (Micro Slurry-jet Erosion) tests, TMA (Thermomechanical Analysis) tests, DMA (Dynamic Mechanical Analysis) tests, etc. The structural changes of the material constituting sample 12 may be measured by methods such as FT-IR (Fourie transformation-infrared) spectroscopy, Raman spectroscopy, NMR (Nuclear Magnetic Resonance) spectroscopy, GC-MS (Gas Chromatography Mass Spectrometry), and molecular weight distribution measurement.

[0080] The evaluation of sample 12 in step S6 may be performed by the control unit 100 or the calculation unit 101 primarily controlling each test device, or it may be performed independently of the control unit 100 or the calculation unit 101.

[0081] The degradation test apparatus 1 of the fifth embodiment determines the set values ​​for the number of oxygen molecules and ozone concentration in the sealed container 10 according to the set value for the light intensity of the light source unit 30. This allows degradation tests to be performed under conditions closer to those of an actual high-altitude environment. Therefore, it is expected that evaluation results will be similar to those obtained when the sample 12 is placed in an actual high-altitude environment.

[0082] In Figure 5, an example is shown in which the degradation test apparatus 1 described in the first embodiment is equipped with a calculation unit 101 and an input unit 102. In contrast, the calculation unit 101 and the input unit 102 may be provided in the degradation test apparatuses 1 and 1A described in the second to fourth embodiments.

[0083] (Examples) Figure 7 is a diagram illustrating the relationship between the wavelength of light and the amount of light used to illustrate an embodiment of the light source. As shown in Figure 7, the light sources 30 and 30A of the example can irradiate the sample 12 with a high light intensity even below 300 nm. In contrast, the light source of the comparative example has a low light intensity below 300 nm. The degradation test apparatus 1 and 1A of the example can perform degradation tests on the sample 12 under extreme conditions such as high-altitude environments.

[0084] Figure 8 is another diagram illustrating the relationship between light wavelength, light intensity, and carbonyl index to illustrate an embodiment of the light source. The dotted line in the figure represents the spectral intensity of sunlight in a high-altitude environment, showing that there is high light intensity even below 300 nm. In contrast, sunlight in an atmospheric pressure environment shows low intensity below 300 nm. In contrast, when examining the spectral intensities of the xenon light source and the metal weather light source, which are the light sources of the xenon weather meter, the intensities below 300 nm are low, making it impossible to use them for degradation tests in high-altitude environments as in the embodiment.

[0085] The carbonyl index shown in Figure 8 is the carbonyl index for the resin and is a parameter that indicates degradation in response to irradiated light. Referring to Figure 8, it can be seen that the resin is most susceptible to degradation at wavelengths around 300 nm (more specifically, around 290 nm) of irradiated light. Therefore, the degradation test apparatus 1 and 1A in the embodiment are able to perform degradation tests on sample 12 by focusing on the fact that sunlight in a high-altitude environment contains light below 300 nm, and that resin degradation becomes significant below 300 nm.

[0086] Although various embodiments and variations have been described, these are merely examples and are not limited to them. For example, one embodiment or variation, or a part of one embodiment or variation, may be combined with one or more other embodiments or variations to realize one aspect of the present invention. [Explanation of Symbols]

[0087] 1. 1A Degradation Test Apparatus 10, 10A sealed container 10a Storage compartment 10b Lid 12 samples 20, 20A Sample holding section 22 Temperature control devices 24 stages 26 Support part 28. Sample holding rotating stand 30, 30A light source section 30, 30A light source section 30a Optical Filter 34 transparent tubes 40 Density adjustment section 42 Gas inlet pipe 44 Humidifier 46 Ozone concentration meter 47 Pressure Regulator 48 Ozone traps 49 Exhaust pipe 50 Temperature adjustment section 52 Temperature regulator 54 Temperature control pump 56 Piping 60 Ozone gas introduction section 62 Ozone gas introduction tube 64 Ozone Gas Generator 66. Light source for ozone gas generation 70 Humidity adjustment section 72 Piping 74 Humidity regulator 76 pumps 80, 80A water spray section 82 Water spray pipe 84 Water flow adjustment section 90 Drainage section 92 Drainage Tank 94 Shut-off valve 96 Drain pipe 98 Ozone Traps 100, 100A control unit 101 Arithmetic section 102 Input section 110 Oxygen concentration meter 112 Pressure gauge 114 Thermometer 116 Hygrometer

Claims

1. A degradation testing apparatus for testing the degradation of a sample, A sealed container, The sealed container includes a sample holding section for holding the sample, A light source unit that irradiates the sample with light, A concentration adjustment unit that reduces the number of oxygen molecules in the sealed container to less than the number of oxygen molecules in an atmospheric pressure environment, A deterioration testing apparatus equipped with the following features.

2. The degradation test apparatus according to claim 1, wherein the concentration adjustment unit controls the number of oxygen molecules in the sealed container to be 5.11 × 10²¹ or less when converted to a volume of 1 liter.

3. A control unit that controls the amount of light emitted from the light source to be greater than the amount of sunlight that should be emitted in the environment assumed to be used in the degradation test of the sample, A calculation unit that calculates the number of oxygen molecules based on the amount of light emitted from the light source unit, The deterioration testing apparatus according to claim 1 or 2, further comprising:

4. The amount of light emitted from the light source and the amount of sunlight are the amounts of light of specific wavelengths contained in the light emitted from the light source and the sunlight. The deterioration testing apparatus according to claim 3.

5. The amount of light emitted from the light source and the amount of sunlight are the integrated amount of light in a specific wavelength band contained in the light emitted from the light source and the sunlight. The deterioration testing apparatus according to claim 3.

6. The calculation unit calculates the number of oxygen molecules to be less than the value obtained by multiplying the amount of sunlight irradiated from the light source by the number of oxygen molecules assumed in the sample degradation test. The deterioration testing apparatus according to claim 3.

7. The deterioration test apparatus according to claim 1 or 2, further comprising a temperature adjustment unit for adjusting the temperature of the sample holding unit.

8. The deterioration test apparatus according to claim 7, wherein the temperature adjustment unit adjusts the temperature of the sample holding unit to a predetermined low temperature, and changes the adjusted temperature of the sample holding unit.

9. The degradation test apparatus according to claim 1 or 2, wherein the concentration adjustment unit controls the number of oxygen molecules by introducing an inert gas into the sealed container.

10. The degradation test apparatus according to claim 1 or 2, wherein the concentration adjustment unit controls the number of oxygen molecules by reducing the pressure inside the sealed container.

11. The degradation test apparatus according to claim 1 or 2, wherein the concentration adjustment unit introduces an inert gas into the sealed container and reduces the pressure inside the sealed container.

12. The deterioration test apparatus according to claim 1 or 2, further comprising an ozone gas introduction unit for introducing ozone gas into the sealed container.

13. A control unit that controls the amount of light emitted from the light source to be greater than the amount of sunlight that should be emitted in the environment assumed to be inside the sealed container, A calculation unit that calculates the concentration of the ozone gas based on the amount of light emitted from the light source unit, The deterioration testing apparatus according to claim 12, further comprising:

14. The calculation unit calculates the ozone gas concentration to be greater than the value obtained by multiplying the amount of sunlight irradiated from the light source by the ozone gas concentration assumed in the sample degradation test. The deterioration testing apparatus according to claim 13.

15. The degradation test apparatus according to claim 1 or 2, wherein the light source emits light including wavelengths of 300 nm or less.

16. The degradation test apparatus according to claim 15, wherein the light source unit repeats a period of irradiating with light and a period of stopping the irradiation of light.

17. The light source unit gradually decreases the number of oxygen molecules from the atmospheric pressure environment as the assumed altitude gradually increases, or gradually increases the number of oxygen molecules from a number lower than that of the atmospheric pressure environment as the assumed altitude gradually decreases. The temperature adjustment unit that adjusts the temperature of the sample holding unit gradually lowers the temperature of the sample holding unit in accordance with the gradually decreasing number of oxygen molecules, or gradually raises the temperature of the sample holding unit in accordance with the gradually increasing number of oxygen molecules. A deterioration testing apparatus according to claim 1 or 2.

18. The deterioration test apparatus according to claim 17, further comprising a spray unit that applies water to the sample as the assumed altitude gradually increases, or applies water to the sample as the assumed altitude gradually decreases.

19. A degradation test method for testing the degradation of a sample, The steps include irradiating the sample, which is held in a sealed container, with light, The steps include reducing the number of oxygen molecules in the sealed container to less than the number of oxygen molecules in an atmospheric pressure environment, A degradation test method, including the following.

20. Steps for preparing the sample, The steps include irradiating the sample, which is held in a sealed container, with light, The steps include reducing the number of oxygen molecules in the sealed container to less than the number of oxygen molecules in an atmospheric pressure environment, A method for producing a sample, including the following:

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