JPH0343579B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the surface environment to which automobiles and the like are exposed;
The present invention relates to an accelerated weathering corrosion tester that simulates both the upper atmospheric environment to which aircraft are exposed, as well as indoor environments such as inside buildings and automobiles.

[Prior Art] All substances and materials deteriorate in the atmosphere. Metals such as steel can rust in the presence of water and oxygen or corrosive gases, and organic materials such as plastics and paints can deteriorate in the presence of ultraviolet light, oxygen and water.

Conventional testing machines for testing the durability of these materials in the atmosphere include accelerated weathering testers, immersion corrosion testers, salt spray testers, and gas corrosion testers, all of which are single-functional tests. However, it is not necessarily possible to perform complex tests. For example, an immersion corrosion tester performs a test under a single condition of repeatedly immersing a sample in water or a corrosive liquid, pulling it up, and drying it, while a salt spray tester performs a test under a single condition of simply spraying salt water onto the sample. The test will be carried out. In addition, an accelerated weathering tester can be said to perform a combined test that sets various conditions such as ultraviolet rays, water, and temperature, but it is an accelerated weathering tester that examines the durability of materials whose main component is polymeric materials on the ground. This test is conducted under limited conditions.

FIG. 1, which shows a conventional accelerated weathering tester, will be explained. There is a light source (sunshine carbon arc lamp or xenon arc lamp) 2 in the center of the test chamber 1, and a sample rotating frame 3 to which a sample 4 is attached rotates around the light source 2, so that the sample is uniformly irradiated. The temperature inside the test chamber rises due to the heat from the light source, but the air inside the test chamber is circulated through the temperature control valve 5, duct 6, humidification tank 7, and blower 8, and the temperature inside the test chamber is adjusted to the setting of the temperature controller. When the temperature becomes higher than this value, the temperature control valve 5 is switched to introduce outside air through the outside air port 10 and exhaust the air inside the tank through the exhaust port 11 to adjust the temperature. Humidity is controlled by a humidity tank 7. The sample spray 9 sprays water onto the sample for a fixed period of time in accordance with a signal from a cycle meter (timer). With the above configuration, the sample is continuously irradiated and water is sprayed intermittently while adjusting the temperature and humidity inside the tank.

For example, if you try to spray water for 12 minutes out of 60 minutes according to the JIS method, the sample rotation frame rotates at a rotational speed of about 1 rpm, so the sample (width 70 mm) will receive water spray about every 60 seconds. 1.5 seconds, which is only 18 seconds in 12 minutes. In this case, (1) the sample temperature has risen and the water spray will not completely wet the sample; (2) the sample will be sprayed intermittently; It has disadvantages such as water not penetrating to the surface, and its deterioration effect is weak.

Next, FIG. 2 showing a conventional immersion corrosion tester will be explained. The test tank 1 consists of an upper air tank 2 and a lower liquid tank 3, and a sample 5 is suspended from a sample holder 4. The sample holder 4 is fixed to a shaft 6 and moved up and down by a crank mechanism 7, immersing the sample in the liquid and then lifting it into the air tank.The hot air device 8 then sends hot air into the tank to dry the sample. Repeat the series of actions. This test is a single-condition test involving repeated soaking and drying, and is only appropriate for testing where the conditions of use of the material are primarily similar to soak-drying.

[Problems with the Prior Art] In recent years, there has been an increasing need for durability testing of materials exposed to the upper atmospheric environment, such as in aircraft, or materials exposed to the earth's surface environment, such as in automobiles. In the upper atmosphere, the oxygen concentration is lower than at the earth's surface, and ultraviolet rays are strong and have short wavelengths, so weather resistance testing conditions for organic materials, mainly polymer materials, have traditionally been conducted only under ground surface conditions. needs to be changed. The same applies to metal materials where not only oxygen and water but also ultraviolet rays, oxygen and water are thought to promote corrosion. In addition, as mentioned above, it is necessary to immerse samples for which the spray effect of the accelerated weathering tester is insufficient and for which a sufficient water effect can be expected by immersion. In addition, when testing paint films, etc., it is necessary to accelerate deterioration and approximate practical results by not only simply immersing in salt water and drying, but also irradiating with light following the immersion and increasing the oxygen concentration. . It was also confirmed that a combined test in which various conditions are repeated in an appropriate order is necessary. Therefore, it has been a challenge to develop a device that can easily perform such various tests in a complex manner.

[Means and effects for solving the problem] In order to solve the above problem, there is a test tank with an air tank in the upper part and a sample immersion tank in the lower part, and a test tank in the center of the air tank for irradiating the sample. A weather resistance test light source, an optical filter surrounding the light source that reduces the wavelength distribution of irradiated light to zero below a specific wavelength, and a sample frame with a sample attached that rotates around the light source are placed between the air tank and the immersion tank. A vertical movement device that moves up and down, a temperature and humidity control room that controls the temperature and humidity inside the test chamber,
Measure the oxygen concentration in the test chamber, supply oxygen to increase the oxygen concentration to 21% or higher, and supply nitrogen to increase the oxygen concentration.
The method used was a weathering and corrosion tester consisting of an oxygen concentration measurement and adjustment device that controlled the oxygen concentration to below 21%.

Because we adopted this method, we conducted tests such as immersing the sample in a solution such as water or salt water to wet it, then exposing the sample to an atmosphere with various oxygen concentrations, irradiating it with light under different conditions, and drying it. It is possible to perform accelerated weathering corrosion tests by reproducing the ground environment, upper atmosphere environment, and indoor environment.

[Example] An example of the present invention will be described with reference to the drawings. FIG. 3 is a front view, and FIG. 4 is a side view.

The upper part of the test tank 1 is an air tank 2 for applying conditions such as light irradiation, temperature, and humidity to the sample, and the lower part is a liquid tank 3 for immersing the sample.

At the upper center of the test tank 1 (at the center of the air tank 2) is a light source 4 (sunshine carbon arc lamp or xenon arc lamp) for weather resistance testing. Depending on the purpose of the test, the light source 4 may be set to zero for wavelengths of 255 nm or less to approximate the rise of ultraviolet rays of sunlight in the upper atmosphere, and to approximate the rise of ultraviolet rays of sunlight in the earth's surface environment. To make wavelengths below 275 nm zero, and to approximate the rise of the ultraviolet part of sunlight that passes through glass in the earth's surface environment and enters indoors.
An optical filter that eliminates light with a wavelength of 300 nm or less,
It is arranged around the light source (between the light source and the sample) so that it can be replaced as necessary (details are not shown).

The sample rotating frame 5, which rotates around the light source 4 with a sample attached, has a cylindrical shape made up of two rings with the same diameter spaced apart vertically, and a ring 6 fixed to the top of this frame is attached to a receiving plate 7. A friction roller 9 supported by a roller 8 fixed to the ring 6 and rotated by a drive motor 10 contacts this ring 6 to rotate the sample rotation frame 5. A receiving plate 7 for fixing the roller 8 is fixed to a bar 11 via a rod 12, and the bar 11 is moved up and down by a vertical movement device 13 such as a screw jack and guided by a guide rod 14. When a sample attached to the sample rotation frame 5 is immersed, the sample rotation frame 5, which is supported by the roller 8 that drives the vertical movement device 13 and lowers the bar 11, moves downward by its own weight and immerses the sample in the liquid. It is immersed in the liquid in tank 3. In this case, the ring 6 separates from the friction roller 9, so the sample rotating frame 5 does not rotate.

The temperature and humidity control chamber 15 is provided in contact with the back side of the test chamber 1, and the inside thereof is equipped with a fan 16 and a heating heater 1.
7, Cooler 18, Humidity tank 19, Humidity tank heater 2
0, etc., and regulates the temperature and humidity while circulating the air inside the test chamber 1. A hot air drying device for drying the sample with hot air is installed outside the device, including a blow heater 21 that heats the blow air, a duct 22 that introduces this air into the test chamber 1, and a duct 22 in the middle of the duct 22. It consists of a check valve 23 placed in the

The oxygen cylinder or nitrogen cylinder 24 is connected to the pressure reducing valve 2
5. Piping is done so that it is introduced into the test tank 1 via the solenoid valve 26 and flow meter 27. Oxygen concentration measurement and adjustment device 2
8 samples the air in the test tank 1, measures the oxygen concentration, and controls the electromagnetic valve 26 according to the detected oxygen concentration to adjust the air in the test tank 1 to a desired oxygen concentration. It is also connected to a recorder 29 to continuously record the air concentration in the test tank 1. Now, if you want to adjust the oxygen concentration to a higher concentration than air, use an oxygen cylinder.
A nitrogen cylinder is used to adjust the oxygen concentration to a low level.

Although not shown, two cylinders, an oxygen cylinder and a nitrogen cylinder, are used, and a separate piping circuit is provided from each cylinder to the inside of the test chamber 1, and the solenoid valve of each piping is controlled according to the signal from the oxygen concentration control device 28. The air inside the test chamber 1 may be controlled.

In the same way as above, a similar piping circuit using gas cylinders such as SO ₂ or H ₂ S is installed, and the gas is sent into the test chamber 1 using a gas concentration controller, and the concentration is adjusted to measure the temperature under corrosive gas. Tests can also be conducted.

According to the above-mentioned apparatus, a test such as immersing a sample in a solution such as water or salt water to wet it, then exposing the sample to an atmosphere with various oxygen concentrations, irradiating it with light of various wavelengths, and drying it is possible. I can do it. If a computer (not shown) or the like is used, it is possible to perform a composite repeated test in which various tests are automatically combined arbitrarily and tested repeatedly. Furthermore, in order to accelerate the deterioration of the sample, it is also possible to create and test conditions that are more severe than the environment in which the sample is actually placed.

Next, a test example performed using the apparatus of the present invention will be explained.

() Accelerated test to simulate the ground environment This test is an accelerated test for things (exterior materials) that are exposed to the environment on the ground, such as buildings and automobiles.

(1) Adjust the oxygen concentration in the test tank to a concentration higher than approximately 21% of the ground level.

(2) Use a light filter for the light source that has zero transmittance below approximately 275 nm, and apply strong energy to the sample with the same rise in ultraviolet light as sunlight on the earth's surface.

(3) The atmospheric temperature within the test chamber shall be adjusted arbitrarily between high and low temperatures depending on the expected region.

(4) Wet the sample by immersing it in water, salt water, etc., and expose it to light and oxygen under the conditions described above.

() Upper atmosphere simulated accelerated test This test is an accelerated test for equipment exposed to the environment in the upper atmosphere, such as aircraft.

(1) Adjust the oxygen concentration in the test tank to a concentration lower than approximately 21% of the ground level.

(2) Use an optical filter for the light source that has zero transmittance for wavelengths of approximately 255 nm or less, or use a quartz filter so that even shorter wavelengths can be irradiated.
It imparts strong energy to the sample with the same rise in ultraviolet light as sunlight in the upper atmosphere.

(3) Adjust the atmospheric temperature in the test chamber to a low temperature or any desired temperature.

(4) Immerse the sample in water to make it wet and react with short wavelength light and oxygen.

() Indoor environment simulated accelerated test This sample is an accelerated test for objects (interior wall materials, interior materials) that are exposed to light transmitted through the window glass of buildings, cars, etc. above the ground.

(1) Adjust the oxygen concentration in the test tank to a concentration higher than approximately 21% of the ground level.

(2) Use a light filter for the light source that has zero transmittance below approximately 300 nm, and apply strong energy to the sample with the same rise in ultraviolet light as sunlight that has passed through the window glass.

(3) Adjust the atmospheric temperature within the sample tank arbitrarily between high and low temperatures depending on the envisaged environment.

(4) Unlike () and (), the sample is exposed to light and oxygen under the above conditions without being wetted with water or salt water.

[Effects] As described above, according to the present invention, combinations of conditions such as immersion (wetting), light irradiation, oxygen reaction, and temperature, which could not be achieved with conventional testing machines, can be performed in the environment where the sample is actually placed, such as Test conditions can be created to suit environments such as ``on the ground,'' ``in the upper atmosphere,'' and ``indoors.'' In addition, the degree of acceleration can be increased by making these conditions more severe, resulting in a weather-resistant corrosion tester with accelerating properties.

[Brief explanation of drawings]

Fig. 1 is a conventional accelerated weathering tester, Fig. 2 is a conventional immersion corrosion tester, Fig. 3 is a partially cutaway sectional view of the testing machine according to the present invention, and Fig. 4 is a partially cutaway side view thereof. It is. In Figures 3 and 4, 1...test tank, 2...air tank, 3...liquid tank, 4
...Light source, 5...Sample rotation frame, 6...Ring, 7
...Socket plate, 8...Roller, 9...Friction roller, 1
0... Drive motor, 11... Bar, 12... Rod,
13... Vertical movement device, 14... Guide rod, 15...
...Temperature and humidity control room, 16...Circulation fan, 17...
... Heater for heating, 18 ... Cooler, 19 ... Humidity tank, 20 ... Humidity heater, 21 ... Air blowing heater, 22 ... Duct, 23 ... Check valve, 24 ...
...oxygen or nitrogen cylinder, 25 ... pressure reducing valve, 26
... Solenoid valve, 27 ... Flowmeter, 28 ... Oxygen concentration measurement and adjustment device, 29 ... Recorder.

Claims (1)

[Claims] 1. A test tank with an air tank at the top and a sample immersion tank at the bottom, a weather resistance test light source located in the center of the air tank to irradiate the sample, and a test tank located around this light source that monitors the wavelength distribution of the irradiated light. An optical filter that makes zero light below a specific wavelength, a vertical movement device that moves a sample frame to which a sample is attached and rotates around a light source up and down between the air tank and the immersion tank, and controls the temperature and humidity in the test tank. A temperature and humidity control room, an oxygen concentration measurement and adjustment device that measures the oxygen concentration in the test chamber, supplies oxygen to keep the oxygen concentration above 21%, and supplies nitrogen to control the oxygen concentration to below 21%. A weathering corrosion tester that performs accelerated weathering corrosion tests by reproducing the ground environment, upper atmosphere environment, and indoor environment.