Weathering resistance testing apparatus and weathering resistance testing method

Abstract

To provide a weather resistance testing apparatus that improves the reproducibility of degradation in real-world environments and shortens the weather resistance test time. [Solution] The weather resistance testing apparatus comprises a holding unit for holding a sample, a container for housing the holding unit, a gas introduction unit for introducing a gas containing oxygen gas into the container, a light irradiation unit for irradiating the sample held in the holding unit with light, a state acquisition unit for acquiring the state of the oxygen gas in the container, a light intensity acquisition unit for acquiring the amount of light emitted from the light irradiation unit, and a control unit that controls at least one of the gas introduction unit and the light irradiation unit so that the relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation unit is a predetermined relationship.

Description

[Technical Field]

[0001] This disclosure relates to a weathering test apparatus and a weathering test method. [Background technology]

[0002] When conducting weather resistance tests to determine how quickly organic and inorganic materials degrade due to sunlight, heat, rain, oxygen in the atmosphere, etc., it is best to conduct the tests in real-world conditions. However, testing in real-world conditions can take a long time to obtain test results. Therefore, weather resistance tests are sometimes conducted using accelerated weathering testing equipment with light sources that have a higher light intensity than sunlight, in order to obtain weather resistance test results for various materials at an earlier stage. Examples of such weather resistance testing equipment include sunshine weatherometers (SWOM), metal weatherometers (MW), super UV (SUV), and xenon weatherometers.

[0003] The Sunshine Weatherometer is a device that uses a carbon arc light source to irradiate a sample with light containing wavelengths from the ultraviolet to the visible light range, and simultaneously sprays water onto the sample for a set period of time using a water spray device, thereby enabling weather resistance testing in a short period of time. This device can shorten the testing period to a certain extent. On the other hand, the Metal Weatherometer and Super UV are devices that use a metal halide lamp, which is a more powerful light source than the SWOM, to irradiate a sample with high-intensity light from the ultraviolet to the visible light range, and simultaneously spray water onto the sample for a set period of time using a water spray device. Because these devices use high-intensity light sources, they can perform weather resistance testing in a shorter period of time than the Sunshine Weatherometer.

[0004] Furthermore, a weather resistance testing apparatus described in Patent Document 1 is known as a weather resistance testing apparatus that enhances safety while accelerating weather resistance testing. In this weather resistance testing apparatus, a light irradiation device with a light source is placed outside the pressurized container, and light is irradiated onto the sample inside the pressurized container from outside the pressurized container. Because the light irradiation device is outside the pressurized container, the influence of the light irradiation device on the pressurized container is reduced in this weather resistance testing apparatus, making it possible to improve safety while accelerating weather resistance testing. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-176912 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In weather resistance testing equipment, the test time is shortened by increasing the light intensity of the light source, which may result in the degree of deterioration (change in appearance) of the sample differing from the degree of deterioration in a real environment. Furthermore, when using weather resistance testing equipment, the test time may be longer than expected.

[0007] This disclosure aims to solve at least one of the above-mentioned problems and to provide a weather resistance testing apparatus and weather resistance testing method that can improve the reproducibility of degradation in real environments and shorten the weather resistance testing time. [Means for solving the problem]

[0008] [1] One aspect of the present disclosure provides a weather resistance testing apparatus. The weather resistance testing apparatus comprises a holding unit for holding a sample, a container for housing the holding unit, a gas introduction unit for introducing a gas containing oxygen gas into the container, a light irradiation unit for irradiating the sample held in the holding unit with light, a state acquisition unit for acquiring the state of the oxygen gas in the container, a light intensity acquisition unit for acquiring the amount of light emitted from the light irradiation unit, and a control unit for controlling at least one of the gas introduction unit and the light irradiation unit so that the relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation unit is a predetermined relationship.

[0009] This weather resistance testing apparatus and method can maintain a constant relationship between the state of oxygen gas and light intensity in the container where the sample is placed, thereby suppressing fluctuations in the test environment caused by variations in this relationship. As a result, the relationship between oxygen gas and light intensity can be maintained in a way that is suitable for reproducing degradation in a real environment, improving the accuracy of reproduction of degradation in a real environment and shortening the test time.

[0010] [2] In the weather resistance test apparatus described in [1] above, the container may be a pressurized container capable of holding a pressurized gas. In this configuration, the pressure inside the container can be increased to accelerate deterioration.

[0011] [3] In the weather resistance test apparatus described in [1] or [2] above, the state acquisition unit acquires the concentration of oxygen gas in the container, the light intensity acquisition unit acquires the light intensity of the component with a wavelength of 290 nm to 450 nm, and the control unit acquires the oxygen gas concentration expressed as a percentage in mW / cm². 2 At least one of the gas introduction section and the light irradiation section may be controlled so that the value obtained by dividing by the light intensity expressed by is 1.2 or greater. For example, polymer degradation proceeds when radicals generated by light combine with oxygen, so even if the light intensity is increased, if there is not enough oxygen to match, it becomes oxygen-limited and the progression of degradation is not accelerated. In this apparatus, the ratio of oxygen gas concentration to light intensity is defined as described above, which effectively shortens the test time.

[0012] [4] In the weather resistance test apparatus described in [3] above, the state acquisition unit may acquire the concentration of oxygen gas in the exhaust pipe provided in the container. In this configuration, damage to the state acquisition unit due to the pressure inside the container is suppressed.

[0013] [5] In any of the weather resistance testing apparatuses described in [1] to [4] above, the light irradiation unit may include a housing having an internal space unaffected by the pressure inside the container, and a light source positioned in the internal space and irradiating light. The light intensity acquisition unit is positioned in the internal space and receives light emitted from the light source. In this configuration, damage to the light intensity acquisition unit due to the pressure inside the container is suppressed.

[0014] [6] In the weather resistance test apparatus described in [5] above, the light emitted from the light irradiation unit may be irradiated onto the sample via a light-transmitting member. The control unit can calculate the amount of light irradiated onto the sample by subtracting the amount of light attenuated by the light-transmitting member from the amount of light received by the light intensity acquisition unit. With this configuration, the amount of light irradiated onto the sample can be appropriately acquired.

[0015] [7] Another aspect of the present disclosure provides a weather resistance test method using any of the weather resistance test apparatuses described in [1] to [6] above. The weather resistance test method comprises the steps of holding a sample in a holding section and irradiating the sample with light from a light irradiation section.

[0016] [8] Another aspect of the present disclosure provides a weathering test method using a weathering test apparatus. The weathering test apparatus comprises a holding section for holding a sample, a container for housing the holding section, a gas introduction section for introducing a gas containing oxygen gas into the container, a light irradiation section for irradiating the sample held in the holding section with light, a state acquisition section for acquiring the state of the oxygen gas in the container, and a light intensity acquisition section for acquiring the amount of light emitted from the light irradiation section. The weathering test method includes the steps of specifying a relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation section, and controlling at least one of the gas introduction section and the light irradiation section so that the relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation section becomes the specified relationship. [Effects of the Invention]

[0017] According to the present disclosure, it is possible to provide a weather resistance test device and a weather resistance test method that can improve the reproducibility of deterioration in a real environment and shorten the weather resistance test time.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the configuration of a weather resistance test device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing an example of a sample (decorative sheet) used in a weather resistance test according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a table showing an example of test results of a weather resistance test according to an embodiment of the present disclosure.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, a weather resistance test device and a weather resistance test method according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In the description, the same reference numerals may be used for the same elements or elements having the same function, and redundant descriptions will be omitted.

[0020] FIG. 1 is a cross-sectional view schematically showing the configuration of a weather resistance test device according to an embodiment of the present disclosure. As shown in FIG. 1, the weather resistance test device 1 includes a pressure vessel 2, a sample holding part 3, a light irradiation device 4, a light quantity detector 40, a gas introduction part 5, a humidifier 6, a gas exhaust pipe 7, a pressure regulator 8, an oxygen gas detector 70, a water spray pipe 9, a water flow regulator 10, a drain pipe 11, a drain valve 12, a temperature regulator 13, and a control part 15.

[0021] In the weathering test apparatus 1, a sample S is held on a sample holding section 3 inside a pressurized container 2, and while introducing a gas such as oxygen or nitrogen from a gas introduction section 5, the pressure inside the pressurized container 2 is adjusted to a predetermined internal pressure using a pressure regulator 8. Then, under this pressurized state, light L from a light irradiation device 4 that simulates sunlight is irradiated onto the sample S, water is sprayed onto the sample S from the tip of a water spray tube 9, and the sample S is further heated by a temperature regulator 13. The temperature regulator 13 may cool the sample S as needed. The gas such as oxygen introduced from the gas introduction section 5 may be humidified by a humidifier 6. The sample S is left in this environment for a predetermined period of time, and a weathering test is performed to determine how quickly the sample S deteriorates due to light such as sunlight, heat, moisture such as rain, oxygen in the atmosphere, etc. Note that the weathering test apparatus 1 may further include a housing that accommodates each of the above-described components, and may be configured to prevent ultraviolet rays and high-intensity light leaking from the light irradiation device 4 from leaking outside.

[0022] The pressurized container 2 is a pressurized, sealed container. The pressurized container 2 has a housing section 2a that houses the sample holding section 3, and a lid 2b that closes the upper opening of the housing section 2a. The lid 2b is removed from the housing section 2a when the sample S is placed inside. After the sample S is placed inside, the lid 2b is attached to the housing section 2a so that the inside is airtight. For example, the lid 2b may be fastened to the housing section 2a by bolts or the like around its perimeter. Various materials can be used for the pressurized container 2 as long as they have pressure resistance against the pressure inside the container. The material of the pressurized container 2 may be, for example, SUS, aluminum alloy, iron, titanium alloy, tungsten alloy, etc.

[0023] The containment section 2a is connected to a gas inlet 5, a gas exhaust pipe 7, a water spray pipe 9, and a drain pipe 11, with the ends of each pipe positioned inside the containment section 2a. This allows a predetermined test gas (such as oxygen) to be introduced into the pressurized container 2 from the gas inlet 5, and unwanted gas to be discharged from the gas exhaust pipe 7. Additionally, water can be sprayed onto the sample S from the water spray pipe 9, and unwanted water can be discharged from the drain pipe 11. In the example apparatus shown in Figure 1, the lid 2b is removed, so the various pipes are connected together to the containment section 2a; however, some of these pipes may be connected to the lid 2b.

[0024] An opening 2c is provided in the area of ​​the lid 2b facing the sample holding portion 3 (sample S) in the center. A light-transmitting member 16 is airtightly fitted into this opening 2c. In one example, the light-transmitting member 16 may be a quartz glass plate formed from quartz glass. The light-transmitting member 16 only needs to be made of a material that can transmit light L (especially ultraviolet light) irradiated from the light irradiation device 4, and may be made of a material other than quartz glass. Since the light-transmitting member 16 constitutes part of the pressurized container 2, it is structured to maintain the atmosphere and pressure inside the pressurized container 2.

[0025] The sample holder 3 holds the sample S to be tested for weather resistance. The sample holder 3 is positioned to face the light-transmitting member 16 in the vertical direction. One example of the sample holder 3 includes a plate-shaped member 3a and a support member 3b that supports the plate-shaped member 3a. The sample S is placed on the plate-shaped member 3a and held in place by being attached with aluminum tape or the like. In one example, the plate-shaped member 3a is positioned so that its upper surface is inclined with respect to the horizontal direction. The plate-shaped member 3a may also be aligned horizontally.

[0026] A temperature controller 13 may be built into the sample holding section 3. The temperature controller 13 is configured, for example, by incorporating a heater and a cooling channel, and adjusts the temperature of the sample S by heating or cooling the sample S by feeding back the value of a thermocouple. The temperature controller 13 makes it possible to perform a weather resistance test by adjusting the temperature of the sample S held in the sample holding section 3 to a predetermined temperature. The heating temperature by the temperature controller 13 is preferably above room temperature and below the decomposition temperature of the sample S. By heating below the decomposition temperature, it is possible to adjust the balance with deterioration due to light, oxygen, humidity, etc., without accelerating deterioration due to heat alone. Alternatively, a gas temperature adjustment mechanism may be provided to adjust the temperature of the gas introduced from the gas introduction section 5 instead of or in combination with the temperature controller 13, or a temperature controller may be provided in the pressurized container 2 to adjust the temperature of the container itself, or a combination of these may be used.

[0027] The light irradiation device 4 irradiates the sample S held in the sample holding section 3 with light L. One example of the light irradiation device 4 includes a housing 4a, a light source 4b arranged inside the housing 4a that irradiates with light L, and an optical filter 4c that removes some wavelengths of light from the light source 4b. The housing 4a has an internal space that is not affected by the pressure inside the pressurized container 2. In this example, the housing 4a is located outside the pressurized container 2 and is therefore not affected by the pressure inside the pressurized container 2. When the housing 4a is placed inside the pressurized container 2, the housing 4a may be formed from a pressure-resistant sealed container. In the illustrated example, the housing 4a is positioned to face the light-transmitting member 16 of the pressurized container 2 and has a light-emitting port 4d facing the light-transmitting member 16. The light-emitting port 4d may be an opening formed in the housing 4a. The light L emitted from the light-emitting port 4d passes through the light-transmitting member 16 and irradiates the sample holding section 3.

[0028] The light source 4b can be any light source that emits light L containing at least ultraviolet light. For example, carbon arcs, high-pressure mercury lamps, xenon lamps, and metal halides used in weathering tests can be used alone or in combination of two different types of light sources. The light source 4b may also be an LED light source or a laser light source. However, it is preferable to use xenon, which has the wavelength closest to that of sunlight, as the light source 4b. Furthermore, it is preferable that the light emitted from the light source 4b contains light in the wavelength range of 290 nm to 450 nm, and preferably contains at least a portion of the light in the wavelength range of 290 nm to 450 nm. It is preferable that the spectral shape of the light emitted from the light source 4b is close to that of sunlight.

[0029] The optical filter 4c is positioned between the light source 4b and the light output port 4d within the housing 4a, and cuts out predetermined wavelength components from the light emitted from the light source 4b. For example, the optical filter 4c may cut out light with wavelengths shorter than 290 nm. In addition, although light with wavelengths longer than 450 nm emitted from the light source 4b does not directly cause degradation of the sample S, light with wavelengths in the infrared region in particular may be left in because it has an effect such as heating the sample S. On the other hand, since the temperature of the sample S is controlled by the temperature controller 13 or the like as described above, infrared light may be cut out by the optical filter 4c in order to eliminate the effect of heating by light.

[0030] The light irradiation device 4 may include lenses, etc., for irradiating the sample S with light from the light source 4b as parallel light. The light irradiation device 4 may also include mirrors, etc., for efficiently directing the light from the light source 4b towards the light output port 4d. The amount of light L irradiated from the light irradiation device 4 should be higher than that of sunlight; for example, the amount of light irradiated from the light source 4b at a wavelength of 365 nm should be 15 mW / cm². 2 More than 60mW / cm 2The following may apply. Note that the "light intensity" referred to here is the value measured with a device that measures the light intensity at a wavelength of 365 nm (for example, the UIT-250 UVD-S365 photodetector manufactured by Ushio Inc.), and is a wavelength distribution with 365 nm as the absolute value calibration wavelength, and is the value of detecting the light intensity in the sensitivity wavelength range of 310 nm to 390 nm.

[0031] The light intensity detector 40 acquires the amount of light emitted from the light irradiation device 4 onto the sample S. For example, the light intensity detector 40 acquires the amount of light with wavelengths from 290 nm to 450 nm from the light emitted from the light source 4b. One example of the light intensity detector 40 may have a light receiving unit that measures the amount of light at the aforementioned wavelength of 365 nm. The light intensity detector 40 (light receiving unit) may be located inside the housing 4a of the light irradiation device 4. For example, the light intensity detector 40 is located downstream of the optical filter 4c so as to receive light from the light source 4b that has passed through the optical filter 4c. In one example, the light intensity detector 40 is provided at the edge of the light output port 4d on the bottom wall of the housing 4a. This allows the light intensity detector 40 to receive light that has passed through the optical filter 4c and does not obstruct the light passing through the light output port 4d.

[0032] Light emitted from the light irradiation device 4 passes through the light-transmitting member 16 to reach the sample S. Therefore, the amount of light detected by the light intensity detector 40 is not exactly the same as the amount of light L irradiated onto the sample S. For example, the light intensity detector 40 may calculate the amount of light irradiated onto the sample by subtracting the amount of light attenuated by the light-transmitting member 16 from the amount of light received. For example, the light intensity detector 40 calculates the amount of light irradiated onto the sample S based on the detected amount of light and the transmittance of the light-transmitting member 16. The transmittance of the light-transmitting member 16 may be acquired in advance. The light intensity information acquired by the light irradiation device is input to the control unit 15. Note that the calculation of the light intensity may be performed by the control unit 15.

[0033] The gas introduction unit 5 is a device for introducing gas containing oxygen and nitrogen into the pressurized container 2. The gas introduction unit 5 includes a gas introduction pipe 5a, an oxygen flow regulator 5b, and a nitrogen flow regulator 5c. The oxygen and nitrogen gas supplied from the outside are supplied to the pressurized container 2 through the gas introduction pipe 5a. In one example of the gas introduction unit 5, the oxygen gas supplied from the oxygen flow regulator 5b and the nitrogen gas supplied from the nitrogen flow regulator 5c are introduced into the pressurized container 2 through the same gas introduction pipe 5a. The flow rate of the supplied gas is adjusted by the oxygen flow regulator 5b and the nitrogen flow regulator 5c. The gas introduction unit 5 adjusts the oxygen gas concentration in the pressurized container 2 between 0% and 100%.

[0034] The humidifier 6 is connected, for example, to the gas inlet pipe 5a and is a device that humidifies the gas introduced by the gas inlet section 5 by bubbling the water inside the humidifier 6. The humidity inside the pressurized container 2 is controlled by the humidifier 6 to a predetermined range. Alternatively, a hygrometer (not shown) may be installed between the humidifier 6 and the pressurized container 2 or inside the pressurized container 2, and the humidification by the humidifier 6 may be controlled by the control unit 15 or the like based on humidity information from the hygrometer.

[0035] The gas exhaust pipe 7 is a pipe for discharging gas from the pressurized container 2. A pressure regulator 8 is attached to the gas exhaust pipe 7, and the pressure regulator 8 maintains the pressure inside the pressurized container 2 at a set pressure. When the pressure regulator 8 detects that the pressure inside the pressurized container 2 has exceeded the set pressure, it opens a valve provided on the gas exhaust pipe 7 and adjusts the pressure to the set pressure. In one example, a pressure gauge (not shown) may be installed inside the pressurized container 2. For example, the pressure regulator 8 may be controlled by the control unit 15 based on the value detected by the pressure gauge.

[0036] The oxygen gas detector 70 acquires the state of the oxygen gas in the pressurized container 2. One example of the oxygen gas detector 70 includes an oxygen gas concentration sensor for detecting the concentration of oxygen gas in the pressurized container 2. In one example, the oxygen gas detector 70 may be installed downstream of the pressure regulator 8 in the gas exhaust pipe 7. The oxygen gas detector 70 measures the oxygen concentration contained in the gas discharged into the gas exhaust pipe 7 and outputs the measurement result to the control unit 15. The oxygen gas detector 70 may be controlled to measure the oxygen concentration at the time when the valve of the gas exhaust pipe 7 is opened by the pressure regulator 8 and the gas in the pressurized container 2 flows into the gas exhaust pipe 7.

[0037] The water spray tube 9 is a component for spraying water onto a sample S placed inside the pressurized container 2. The water spray tube 9 sprays water supplied from outside the pressurized container 2 onto the sample S inside the pressurized container 2 after adjusting the flow rate using the water flow rate regulator 10. The water flow rate regulator 10 is a device that adjusts the amount of water sprayed onto the sample S from the water spray tube 9, and the water volume is set according to the required amount. A spray nozzle is attached to the tip of the water spray tube 9 inside the pressurized container 2, and this spray nozzle allows water to be sprayed (in a spray, mist, or shower) over the entire sample S. The force of the water sprayed from this spray nozzle can also be adjusted by adjusting the water flow rate regulator 10. The spraying device using the water spray tube 9 and water flow rate regulator 10 is a device that simulates rain in a real environment, and the water sprayed may be pure water, tap water, water adjusted to simulate acid rain, water containing metal ions, hydrogen peroxide, etc.

[0038] The drain pipe 11 is a component for discharging water sprayed from the water spray pipe 9 inside the pressurized container 2 to the outside of the pressurized container 2. A drain valve 12 is attached to the drain pipe 11, and by operating the drain valve, excess water is discharged. The drain valve 12 is normally closed during the weathering test and is controlled to maintain the pressure and atmosphere (oxygen gas concentration, etc.) inside the pressurized container 2. When predetermined conditions are met, such as by a water level sensor (not shown) or time, the drain valve 12 is opened by the control unit 15, thereby discharging excess water and other substances from inside the pressurized container 2 to the outside of the container. When the conditions determined by the water level sensor are resolved or a predetermined time has elapsed, the drain valve 12 is closed again by the control unit 15.

[0039] The control unit 15 is a device that controls the overall operation of the weather resistance test apparatus 1, and is composed of, for example, a computer equipped with a CPU, memory, input device, etc. The control unit 15 is electrically connected to the light irradiation device 4, gas introduction unit 5, humidifier 6, pressure regulator 8, water flow regulator 10, drain valve 12, and temperature regulator 13 via wiring, and controls the operation of each device.

[0040] For example, in polymers, it is thought that degradation progresses as radicals are generated by light irradiation, and these radicals combine with oxygen. Therefore, one example of a control unit 15 controls at least one of the gas introduction unit 5 and the light irradiation device 4 so that the relationship (balance) between the state of oxygen gas in the pressurized container 2 and the amount of light L irradiated from the light irradiation device 4 is in a predetermined relationship. For example, the control unit 15 controls the oxygen gas concentration, expressed as a percentage, in mW / cm². 2 The gas introduction unit 5 and the light irradiation device 4 are controlled so that the value obtained by dividing by the light intensity expressed by (hereinafter referred to as the "intensity-light intensity ratio") becomes a predetermined value or range.

[0041] In one example, the intensity-to-light ratio may be controlled to be 1.2 or higher. In particular, if the light source 4b of the light irradiation device 4 is a xenon lamp, the intensity-to-light ratio may be controlled to be 1.5 or higher. In one example of weather resistance testing apparatus, the intensity-to-light ratio may be settable by the user.

[0042] The control unit 15 calculates a concentration-to-light ratio based on the light intensity obtained by the light intensity detector 40 and the oxygen gas concentration obtained by the oxygen gas detector 70, and controls at least one of the gas introduction unit 5 and the light irradiation device 4 based on a comparison of the calculated concentration-to-light ratio with a set concentration-to-light ratio. For example, if the calculated concentration-to-light ratio is lower than the set concentration-to-light ratio, the control unit 15 may control the gas introduction unit 5 to increase the oxygen gas concentration and increase the amount of oxygen gas introduced. Alternatively, for example, if the calculated concentration-to-light ratio is higher than the set concentration-to-light ratio, the control unit 15 may control the light irradiation device 4 to increase the light intensity and increase the light intensity.

[0043] In one example of a weather resistance test apparatus, the amount of light emitted may be adjusted to change over time. In this case, if the calculated density-to-light ratio becomes higher than the set density-to-light ratio due to a decrease in light intensity, the control unit 15 may control the gas introduction unit 5 to lower the oxygen gas concentration. Similarly, if the calculated density-to-light ratio becomes higher than the set density-to-light ratio due to a decrease in light intensity associated with changes in the light source over time, the gas introduction unit 5 may be controlled to lower the oxygen gas concentration. For example, the control unit 15 may acquire the lighting time of the light source. The control unit 15 may determine that the decrease in light intensity of the light source is due to changes over time if the cumulative lighting time is greater than or equal to a predetermined time.

[0044] Here, we will describe a weather resistance test method using the weather resistance test apparatus 1 with the configuration described above. In the weather resistance test method, first, a sample S to be used for the weather resistance test is prepared. There may be one sample S or multiple samples S. Furthermore, the sample S is not limited to the decorative sheet described later, but may also be a component made of various inorganic or organic materials, and is not particularly limited. Once such a sample S is prepared, the lid 2b of the pressurized container 2 is removed and the sample S is held in place by attaching it to the sample holding part 3. After that, the lid 2b is airtightly attached to the housing part 2a and fixed with bolts or the like. This makes the pressurized container 2 containing the sample S airtight.

[0045] Next, the control unit 15 sets the pressure using the pressure regulator 8 so that the density-to-light ratio at the expected light intensity is 1.2 or higher, and introduces a predetermined flow rate of gas (oxygen gas or nitrogen gas) into the pressurized container 2 from the gas introduction unit 5. Furthermore, the water flow rate regulator 10, controlled by the control unit 15, adjusts the water flow rate, which is then supplied to the sample S from the nozzle of the water spray pipe 9 continuously or at predetermined intervals. Finally, the temperature regulator 13 adjusts the temperature under the control of the control unit 15, maintaining the sample S at a predetermined temperature (e.g., 80°C). In this state, the weather resistance test apparatus 1 irradiates the pressurized container 2 with predetermined light L from the light irradiation device 4 via the light-transmitting member 16, irradiating the sample S. In one example of the control unit 15, the user may be able to specify the density-to-light ratio before the start of the test by operating an input device. In this case, initial values ​​such as light intensity and oxygen concentration may be specified.

[0046] Next, the degradation state of sample S is tested by continuously maintaining the conditions of light irradiation, pressurization, temperature control, and water supply. Such weather resistance tests may be carried out continuously for, for example, 200 to 1000 hours. Alternatively, the weather resistance test may be carried out continuously for 3 to 6 months, or for 6 months or more, or even for 1 year or more. Furthermore, light irradiation, water spraying, etc., may be repeated at predetermined intervals while maintaining predetermined pressurization and temperature control. Such test conditions can be appropriately selected to be similar to those in actual environmental conditions.

[0047] As described above, one aspect of this disclosure provides a weather resistance testing apparatus 1. The weather resistance testing apparatus 1 comprises a sample holding section 3 for holding a sample S, a pressurized container 2 for housing the sample holding section 3, a gas introduction section 5 for introducing a gas containing oxygen gas into the pressurized container 2, a light irradiation device 4 (light irradiation section) for irradiating the sample S held in the sample holding section 3 with light, an oxygen gas detector 70 (state acquisition section) for acquiring the state of the oxygen gas in the pressurized container 2, a light intensity detector 40 (light intensity acquisition section) for acquiring the amount of light emitted from the light irradiation device 4, and a control unit 15 for controlling at least one of the gas introduction section 5 and the light irradiation device 4 so that the relationship between the state of the oxygen gas in the pressurized container 2 and the amount of light from the light irradiation device 4 is a predetermined relationship.

[0048] In this weather resistance testing apparatus 1, the relationship between the state of oxygen gas in the pressurized container 2 where the sample S is placed and the amount of light can be kept constant, thereby suppressing fluctuations in the test environment caused by changes in this relationship. As a result, the relationship between oxygen gas and light intensity can be maintained in a way that is suitable for reproducing degradation in a real environment, improving the accuracy of reproduction of degradation in a real environment and shortening the test time.

[0049] In the weather resistance testing apparatus 1 described above, a pressurized container 2 capable of holding pressurized gas is used. In this configuration, the pressure inside the pressurized container 2 can be increased to accelerate deterioration.

[0050] In the weather resistance test apparatus 1 described above, the oxygen gas detector 70 acquires the concentration of oxygen gas in the pressurized container 2, the light intensity detector 40 acquires the light intensity of components with wavelengths of 290 nm to 450 nm, and the control unit 15 converts the oxygen gas concentration, expressed as a percentage, into mW / cm². 2 At least one of the gas introduction unit 5 and the light irradiation device 4 may be controlled so that the value obtained by dividing by the light intensity expressed by is 1.2 or greater. For example, in polymers, degradation progresses when radicals generated by light combine with oxygen. Therefore, even if the light intensity is increased, if there is not enough oxygen to match it, it becomes oxygen-limited, and the progression of degradation is not accelerated. In this device, the ratio of oxygen gas concentration to light intensity is defined as described above, which effectively shortens the test time.

[0051] In the weather resistance test apparatus 1 described above, the oxygen gas detector 70 may acquire the concentration of oxygen gas in the gas exhaust pipe 7 provided in the pressurized container 2. In this configuration, damage to the oxygen gas detector 70 due to the pressure inside the pressurized container 2 is suppressed.

[0052] In the weather resistance test apparatus 1 described above, the light irradiation device 4 may include a housing 4a having an internal space unaffected by the pressure in the pressurized container 2, and a light source positioned in the internal space to emit light. The light intensity detector 40 is positioned in the internal space and receives the light emitted from the light source. In this configuration, damage to the light intensity detector 40 due to the pressure in the pressurized container 2 is suppressed.

[0053] In the weather resistance test apparatus 1 described above, the light emitted from the light irradiation device 4 may be irradiated onto the sample S via the light-transmitting member 16. The control unit 15 can calculate the amount of light irradiated onto the sample S by subtracting the amount of light attenuated by the light-transmitting member 16 from the amount of light received by the light intensity detector 40. With this configuration, the amount of light irradiated onto the sample S can be appropriately obtained.

[0054] The weather resistance testing apparatus according to this embodiment has been described above, but the weather resistance testing apparatus according to this disclosure is not limited to the above embodiment, and various modifications can be applied. For example, the control unit 15 controls the partial pressure concentration of oxygen gas expressed in %, in mW / cm². 2 At least one of the gas introduction unit 5 and the light irradiation device 4 may be controlled so that the value obtained by dividing by the light intensity expressed by (hereinafter referred to as the "partial pressure concentration light intensity ratio") becomes a predetermined value or range. The partial pressure concentration may be the ratio of partial pressures based on a state of 1 atmosphere. For example, if the atmospheric pressure inside the pressurized container is 2 atmospheres and the oxygen gas concentration in that state is 20%, the oxygen partial pressure is 0.4 atmospheres and the partial pressure concentration is 40%. [Examples]

[0055] The present disclosure will be described in more detail below with reference to examples. However, the present disclosure is not limited to these examples.

[0056] (Weather resistance test) The weather resistance test of the decorative sheet was conducted using the weather resistance testing apparatus 1 shown in Figure 1. The method for manufacturing the decorative sheet used in this weather resistance test is as follows. Figure 2 shows the structure of the decorative sheet 30.

[0057] <Production of Transparent Resin Sheet> To a highly crystallized homopolypropylene resin, 500 PPM of a hindered phenol-based antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals), 2000 PPM of a benzotriazole-based ultraviolet absorber (Tinuvin 328, manufactured by Ciba Specialty Chemicals), 2000 PPM of a hindered amine-based light stabilizer (Chimasorb 944, manufactured by Ciba Specialty Chemicals), and 1000 PPM of a phosphate ester metal salt-based nucleating agent (Adekastab NA-21, manufactured by ADEKA) were added, and the resin was extruded using a melt extruder to form a transparent resin sheet 31 (resin layer) of highly crystalline polypropylene with a thickness of 100 μm for use. Subsequently, corona treatment was applied to both surfaces of the formed transparent resin sheet 31 to make the surface wettability 40 dyn / cm or more. By changing the extrusion temperature during extrusion film formation and cooling conditions such as rolls, various transparent resin sheets were produced.

[0058] <Production of Cosmetic Sheet> On one side of the transparent resin sheet 31 made of the obtained transparent resin sheet, pattern printing was performed with a two-component curable urethane ink (V180, manufactured by Toyo Ink Co., Ltd.) to apply a pattern layer 32. After that, a concealing two-component curable urethane ink (V180, manufactured by Toyo Ink Co., Ltd.) was applied at a coating amount of 6 g / m 2 to form a concealing layer 33. Further, on top of the concealing layer 33, a two-component curable urethane ink (PET-E, Resizer, manufactured by Dainichi Seika Co., Ltd.) was applied at a coating amount of 1 g / m 2 to form a primer layer 35.

[0059] Next, the surface of the transparent resin sheet 31 of this sheet was pressed using an embossing mold roll to apply an embossed pattern 31a. After that, a two-component curable urethane top coat (W184, manufactured by Dainippon Ink and Chemicals, Inc.) was applied at a coating amount of 3 g / m 2The material was applied to obtain a decorative sheet 30 with a total thickness of 110 μm, including the coating layer 34. This decorative sheet 30 was bonded to a metal substrate using a urethane-based adhesive, and its weather resistance was evaluated using the weather resistance test apparatus 1 shown in Figure 1.

[0060] Figure 3 is a table showing the evaluation results. Figure 3 shows the light intensity, gauge pressure, oxygen concentration, presence or absence of spraying, concentration-to-light ratio, observed degradation patterns, and test time for each example. The light intensity and oxygen concentration are values ​​obtained at the start of the test. In Examples 1-6, the concentration-to-light ratio was controlled to be 1.2 or higher. Specifically, in Example 1, the concentration-to-light ratio was controlled to 1.5; in Example 2, to 1.9; in Example 3, to 1.5; in Example 4, to 1.3; in Example 5, to 1.5; and in Example 6, to 1.3. In Comparative Examples 1-4, control based on the concentration-to-light ratio was not performed. The light intensity, oxygen concentration, and concentration-to-light ratio shown in the Comparative Examples were measured at the start of the test. Comparative Example 5 shows the results of an actual exposure test.

[0061] In the weather resistance test apparatus 1 used in the examples and comparative examples, an optical filter that transmits wavelengths from 290 nm to 490 nm is used. The light source 4b is a xenon lamp. The light intensity detector 40 is an illuminometer (UIT250 with UVD-S365 light receiver, manufactured by Ushio Inc.) with an absolute value calibration wavelength of 365 nm that can detect light intensity at wavelengths from 330 nm to 390 nm. In Examples 1 to 6 and Comparative Examples 1 to 4, irradiation, water spraying, condensation, water spraying, and irradiation were repeated in sequence within the test time.

[0062] <Rating> After weathering tests using a weathering test apparatus, the degradation morphology of the samples was evaluated by visual observation, based on whether the actual weathering conditions were reproduced. Visual observation involved comparing the presence or absence of cracks on the sample surface using a microscope and a laser microscope. In addition, the presence or absence of delamination was checked by hand.

[0063] As shown in the table in Figure 3, the sample from Comparative Example 5, which underwent a weather resistance test under real-world conditions (8 years), showed both surface cracking and internal delamination. On the other hand, while surface cracking occurred in Comparative Examples 1-4, delamination of the decorative sheet layer, as seen under real-world conditions, did not occur.

[0064] On the other hand, in Examples 1 to 6, surface cracks and delamination of the internal layers were observed, similar to the samples in the weather resistance test of Comparative Example 5. [Explanation of Symbols]

[0065] 1...Weathering test apparatus, 2...Pressurized container (container), 3...Sample holder (holding part), 4...Light irradiation device (light irradiation part), 4b...Light source, 4c...Optical filter, 5...Gas inlet, 7...Gas exhaust pipe, 8...Pressure regulator, 15...Control unit, 16...Light transmitting member, L...Light, S...Sample.

Claims

1. A holding part for holding the sample, A container for housing the aforementioned holding part, A gas introduction section for introducing a gas containing oxygen gas into the container, A light irradiation unit that irradiates light onto the sample held in the holding unit, A state acquisition unit that acquires the state of the oxygen gas in the container, A light intensity acquisition unit that acquires the amount of light emitted from the light irradiation unit, A weather resistance testing apparatus comprising a control unit that controls at least one of the gas introduction unit and the light irradiation unit so that the relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation unit is a predetermined relationship.

2. The weather resistance testing apparatus according to claim 1, wherein the container is a pressurized container capable of holding the pressurized gas.

3. The state acquisition unit acquires the concentration of the oxygen gas in the container, The light intensity acquisition unit acquires the light intensity of components in the light whose wavelength is 290 nm to 450 nm. The control unit converts the oxygen gas concentration (%) to the light intensity (mW / cm²). ２ The weather resistance testing apparatus according to claim 1, wherein at least one of the gas introduction section and the light irradiation section is controlled so that the value obtained by dividing by ) is 1.2 or more.

4. The weather resistance test apparatus according to claim 3, wherein the state acquisition unit acquires the concentration of the oxygen gas in the exhaust pipe provided in the container.

5. The light irradiation unit is A housing having an internal space that is not affected by the pressure inside the container, The interior space includes a light source that emits light, The weather resistance testing apparatus according to any one of claims 1 to 4, wherein the light intensity acquisition unit is arranged in the internal space and receives light emitted from the light source.

6. The light emitted from the light irradiation unit is irradiated onto the sample via the light-transmitting member. The weather resistance testing apparatus according to claim 5, wherein the control unit calculates the amount of light irradiated onto the sample as the amount of light obtained by subtracting the amount of light attenuated by the light-transmitting member from the amount of light received by the light intensity acquisition unit.

7. A test method for evaluating the weather resistance of a sample using the weather resistance test apparatus described in claim 1, The step of holding the sample in the holding part, A step of irradiating the sample with light from the light irradiation unit, A weather resistance test method comprising the following features.

8. A weather resistance test method using a weather resistance testing apparatus, The weather resistance testing apparatus is, A holding part for holding the sample, A container for housing the aforementioned holding part, A gas introduction section for introducing a gas containing oxygen gas into the container, A light irradiation unit that irradiates light onto the sample held in the holding unit, A state acquisition unit that acquires the state of the oxygen gas in the container, The system includes a light intensity acquisition unit that acquires the amount of light emitted from the light irradiation unit, The method is, A specifying step of specifying the relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation unit, A weather resistance test method comprising: a control step of controlling at least one of the gas introduction unit and the light irradiation unit so that the relationship between the state of the oxygen gas in the container and the amount of light from the light irradiation unit is a relationship specified in the specified step.

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