JP2001194291A - Ozone exposure test method and ozone exposure test apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new ozone exposure test method imparting high reproducibility and reliability and an apparatus fitted thereto. SOLUTION: In the ozone exposure test method, the flow rate of air is measured during an ozone exposure test, for example, by a flowmeter 2 to control a blower 3 and the flow rate per minute of air circulating through a test tank 1 is set to more than 5% of the inner volume of the test tank 1 and the fluctuation width of the flow rate is controlled to 10% or less of the set value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone exposure test method and an apparatus therefor, and more specifically, to an ink-jet or printing, sublimation transfer, thermal transfer, electrophotography, silver halide photography, self-coloring recording, etc. The present invention relates to an ozone exposure test method for a medium such as paper or a sheet and an image on the medium, and an apparatus for the same.

[0002]

2. Description of the Related Art In recent years, image fastness of recorded matters such as printing, ink jet, and silver halide photography has been required. As described in JP-A-63-252780, an ozone exposure test is effective as a method for examining the occurrence of indoor fading of these recorded materials and the recording medium itself.

Conventionally, an ozone exposure apparatus has been proposed, but some apparatuses do not have a mechanism for sufficiently controlling the temperature and humidity of a test tank. The Japan Rubber Association Journal Vol. 62 No. 7
No. (1989), pp. 423-437, describe an ozone test and an ozone tester. In particular, a precise measuring method of the ozone concentration is described therein. Also,
Suga Technical News No. 161 (edited by Suga Test Machine Co., Ltd., issued on December 25, 1998)
In the case of the ozone test, it is described that it is determined that 3/4 (94 L) of the test tank internal volume is replaced every minute. However, neither of the above documents describes the circulation of the gas whose ozone concentration has been adjusted in the test tank or the circulation flow rate in the test tank. In the ozone exposure test for planar substances such as paper and sheets, it was pointed out that the results of the ozone exposure test differ not only depending on the ozone concentration in the test tank but also on the circulating flow rate of gas containing ozone in the test tank. Have been.

[0004]

As described above, the ozone exposure test is an extremely effective means for verifying the image fastness of a recorded matter by printing, ink-jet printing, silver halide photography, and the like. However, the reproducibility of the test results and its reliability were not sufficient. In other words, there is a need for a proposal of a highly reproducible and reliable ozone exposure test method suitable for the purpose of predicting the occurrence of indoor fading of these recorded materials and the recording medium itself with high accuracy.

The present invention solves the above-mentioned problems, and
An object of the present invention is to provide a new ozone exposure test method that provides high reproducibility and reliability. More specifically, when applying to the ozone exposure test of a planar substance such as paper or sheet, a test method that has high reproducibility and reliability of the test result and a test device that can be used for tests based on that method To provide.

[0006]

Means for Solving the Problems The present inventor has conducted intensive studies to achieve the above object, and as a result, has been applied to ink jet, printing, sublimation transfer, thermal transfer, electrophotography, silver halide photography, self-coloring recording, and the like. The medium to be used, such as paper or sheet, and the image on the medium are the water-absorbing or moisture-absorbing materials to be tested, and in the ozone exposure test of these water-absorbing or moisture-absorbing materials, It was found that there was a clear correlation between the circulating flow rate of the gas inside the test chamber where ozone was exposed and the deterioration caused by ozone exposure.

Specifically, in a conventional ozone exposure tester, a gas whose ozone concentration has been adjusted is circulated in a test tank when an ozone exposure test is performed. When the exposure test is performed continuously, the measurement results often do not match when the first and second times, and furthermore, the third time are repeated. On the other hand, during the ozone exposure test, the gas circulating flow rate in the test chamber was set to a flow rate per minute of 5 times or more of the capacity of the test chamber, and the fluctuation of the gas circulating flow rate was not more than ± 10% of the set value. , It was found that the reproducibility of the measurement results was good even if the ozone exposure test was performed continuously. Based on such knowledge, the present invention has been completed.

[0008] That is, a method provided by the present invention is an ozone exposure test method, wherein the gas circulation flow rate in the test tank during the ozone exposure test is set to a flow rate per minute of at least 5 times the internal volume of the test tank. And performing ozone exposure while controlling the variation of the gas circulation flow rate within a range of ± 10% of the gas circulation flow rate set value.

Preferably, the fluctuation of the gas circulation flow rate is controlled within a range of ± 5% of the gas circulation flow rate set value. In addition to such control of the gas circulation flow rate, during the ozone exposure test, the ozone concentration in the test tank was adjusted to an ozone concentration set value of ± 3.
It is better to control within%. In addition, it is preferable that, during the ozone exposure test, a gas adjusted to a constant temperature and a constant humidity is introduced into the test tank and the inside of the test tank is adjusted to a constant temperature and a constant humidity together with the gas circulation in the test tank. .

Further, the present invention also provides an ozone exposure test apparatus as a test apparatus suitable for performing the above-mentioned test method, comprising a mechanism for measuring and adjusting a gas circulation flow rate in a test tank. provide. That is, when the above-described ozone exposure test apparatus is used, the above-described ozone exposure test method of the present invention can be more reliably performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ozone exposure test method of the present invention
By performing gas circulation as described above and maintaining ozone at a predetermined concentration in any place of the test tank during the ozone exposure test, when repeated measurements are performed, the reproducibility of each test is increased. . In particular, when a medium such as paper or sheet having a large surface area of the sample to be tested and an image on the medium are to be tested, the amount of water contained on the surface of the medium having high water absorbency or hygroscopicity is measured. Because of the uniformity, the distribution in the sample plane is eliminated, and not only the reproducibility of the test result is improved, but also the reliability of the test itself can be increased.

Hereinafter, the ozone exposure test method of the present invention and the apparatus used therein will be described more specifically with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of a test apparatus suitable for the ozone exposure test method of the present invention. At the time of the ozone exposure test, the sample under test is left inside the test tank 1 for a predetermined test time to perform ozone exposure. During that time, the ozone concentration is continuously monitored by the ozone concentration measuring device 11 in order to maintain the inside of the test tank 1 at a predetermined ozone concentration. Ozone is supplied from the ozone generator 12 to compensate for the decrease in ozone due to spontaneous deactivation and consumption by the exposed test sample.

In the apparatus configuration shown in FIG. 1, an ozone concentration measuring instrument 11 is arranged near the upper end of the test tank 1 and an ozone generator 12 is arranged near the lower end of the tank. In addition, near the upper end of the tank, an outlet from the test tank 1 to the circulation system for controlling temperature and humidity, and on the lower end of the tank,
An inlet from the circulating system for humidity control to the test tank 1 is provided. With the flow of gas from this inlet to the outlet,
Ozone continuously supplied from the ozone generator 12 is carried to the center of the tank and consumed in the test. In the circulation system for controlling temperature and humidity, a blower 3 for taking in a gas from an outlet of the test tank 1, and a dehumidifier 4, a heating / humidifier 5, and an ozone concentration controller 6 are sequentially arranged downstream of the blower 3. Further, a flow meter 2 for measuring the flow rate of the gas returned from the circulation system to the inlet to the test tank 1 is provided at the most downstream portion of the circulation system path.

A gas containing ozone is supplied from a test tank 1 to a blower 3.
However, in this gas, gases generated during the ozone exposure test or suspended particulates are often mixed. If necessary, a filter for removing the fine particles and the like and a filter for removing gases and the like can be provided in the circulation system. For example, it is preferable to attach the filter to the intake of the blower 3. The gas taken in by the blower 3 is cooled by the dehumidifier 4 to lower the temperature and remove the contained moisture. Next, the cooled and dehumidified gas is passed through a heating and humidifier 5, where the gas is heated by a heater or the like and heated to a predetermined temperature. At the same time, humidification is performed to a predetermined humidity by adding steam or the like. During the cooling / dehumidifying process and the heating / humidifying process, the concentration of ozone generally contained in the gas gradually decreases. The gas is passed through an ozone concentration controller 6 to measure the remaining ozone concentration. At this time, if the remaining ozone concentration is lower than the predetermined concentration, ozone is added in the ozone concentration controller 6 until the concentration reaches the predetermined concentration.

The flow rate of the circulating gas that has passed through the temperature / humidity control circulating system is measured by a flow meter 2 provided last. For example, an air flow meter can be used as the flow meter 2 to measure the air flow and convert it to a circulating flow rate. The circulation flow rate (air volume) measured by the flow meter 2 (air flow meter) is fed back to the blower 3 by a control system (not shown), and the circulation flow rate and the fluctuation of the circulation flow rate are controlled within a predetermined range.

In the method of the present invention, the gas circulating flow rate in the test chamber during the ozone exposure test is set so that the flow rate per minute is at least five times the internal volume of the test chamber, and the fluctuation of the gas circulating flow rate is as described above. Control within ± 10% of set value. Preferably, the fluctuation range is controlled within a range of ± 5% of the set value. In the apparatus having the configuration shown in FIG. 1, the circulation of the gas in the test tank is mainly performed by the circulation taken out of the test tank. In addition, the method of the present invention includes a mode mainly including internal circulation of the test tank, in addition to the above-described circulation taken out from the test tank. Further, a circulating system for supplying a new gas from the outside to discharge a part of the gas from the circulating system to the outside and make up for the discharged amount is also included. In addition, in the present invention, the ozone concentration measuring device 11 and the ozone generator 12 can be provided separately from the circulation system.

Further, if the fluctuation range of the gas circulation flow rate in the test tank is controlled within a range of 5% of the set value, it is possible to prevent the diffusion of the coloring material and the like of the test sample. For example, as the flow rate is increased, the induced vibration of the test sample due to a large flow rate fluctuation (pulsation) becomes relatively strong, and the scattering and diffusion of fine particles such as powdered coloring material also increase. If the fluctuation range of the flow rate is controlled within the range of 5% of the set value, the above-described pulsation phenomenon does not occur, and the diffusion of the coloring material or the like of the test sample is effectively prevented. Therefore, when an image on a medium such as paper or a sheet is to be tested, a systematic error caused by a diffused color material or the like can be suppressed, and a more reliable test method can be achieved.

In the ozone exposure test method of the present invention,
It is preferable that the inside of the test tank is controlled at a constant temperature and a constant humidity. In other words, by keeping the temperature and humidity in the test tank constant, even if the sample to be tested is a water-absorbing or hygroscopic material, the amount of water contained in each sample does not change for each test. Measurement with good reproducibility can be performed. In addition, in the method of the present invention, the fluctuation range of the ozone concentration is preferably within a set value ± 3%. Within this range of fluctuation, an accurate test can be performed without depending on the exposure time and suppressing a change in the measured value due to the ozone concentration. In the method of the present invention, the gas circulation flow rate in the test tank is set to be at least five times the internal volume of the test tank, so that the fluctuation range of the ozone concentration can be substantially suppressed. Therefore, even if an abrupt change (decrease) in the ozone concentration occurs instantaneously, the change (decrease) is uniformed and restored in a short time, and the fluctuation range of the ozone concentration is set to ± (set value). 3%
It also has the effect of balancing within.

The ozone exposure test apparatus of the present invention is an apparatus having a mechanism for measuring a gas circulation flow rate in a test tank and adjusting the flow rate. For example, the apparatus configuration shown in FIG. This is an example of a preferred mode. That is, in the apparatus configuration shown in FIG. 1, the mechanism for measuring the gas circulation flow rate in the test tank and the mechanism for adjusting the flow rate are disposed in the circulation system separately from the test tank, and additionally circulate. The temperature / humidity of the gas itself and also the ozone concentration can be controlled to predetermined values, which is a more preferable device.

[0021]

EXAMPLES Specific examples are given below to show the ozone exposure test method of the present invention and that high reproducibility and reliability of the results are achieved by this method. The following specific example is an example of the best embodiment of the present invention, but the present invention is not limited to such a specific embodiment.

Examples 1 to 3 An ozone tester (product name: ozone weatherometer, manufactured by Suga Test Instruments Co., Ltd.) was equipped with a test volume and a flow meter in a circulating system for controlling temperature and humidity. The configuration was the same as. In addition, a mechanism for controlling the air flow rate (circulation flow rate) of the blower based on the measurement value of the circulation flow rate measured by the air flow meter was installed. Put the sample under test in this ozone tester,
An ozone exposure test was performed under the following conditions. Table 1 shows the set value of the gas circulation flow rate circulated in the test tank of the ozone test apparatus and the fluctuation range in the flow rate control in each example. The temperature and humidity in the test tank were kept constant by a circulation system for controlling temperature and humidity.

[0023]

[Table 1]

Test tank temperature: 45 ° C. Test tank humidity: 55% RH Ozone concentration: 3 ppm Exposure test time: 120 minutes The test sample was obtained as follows. The print media is
Silica (Sylysia 4) at a ratio of 3: 1 on a dry solids basis
No. 50, manufactured by Fuji Silysia Chemical Ltd.) and polyvinyl alcohol (NH-18, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and a commercially available electrophotographic paper (EN-500, Canon Inc.) having a dry solid content of 20 g / m ^2. Manufactured), paper coated on the surface was used. On this paper, an ink jet printer (B
JC430 (manufactured by Canon Inc.), a black solid pattern with a duty of 100% printed at a size of 20 × 20 mm was used as a test sample. In the ozone exposure test, the fading of the print pattern was evaluated.

For fading, before and after exposure to ozone, the optical density of the printed pattern is measured using a densitometer (310TR, manufactured by X-1ite).
And the residual ratio was calculated by the following equation. Residual rate (%) = optical density after exposure to ozone / optical density before exposure to ozone * 100 In each of the examples, an ozone exposure test was continuously performed five times by the same operation in order to verify reproducibility. The results were compared between the examples to verify the reliability and variation of the test results.

Table 2 also shows the test results of each example. From the results shown in Table 2, the gas circulation flow rate in the test tank was
The flow rate per minute was set to 5 times or more of the internal volume of the test tank, and the fluctuation range of the flow rate was controlled within 10% of the set flow rate. As a result, the reproducibility was good under each condition (in the example). It turns out there is. Further, even when the examples are compared with each other, there is no variation in the results, and it can be seen that the ozone exposure test itself is highly reliable. In particular, the fluctuation range of the flow rate is set to 5
%, The reproducibility is higher.

[0027]

[Table 2]

[0028]

According to the ozone exposure test method of the present invention,
During the ozone exposure test, the gas circulating flow rate in the test tank was maintained at a flow rate per minute of 5 times or more the internal volume of the test tank, and the fluctuation was controlled within 10% of the set flow rate. The effect occurred. That is, ozone exposure can be performed by controlling the water content of the test sample, and when the ozone exposure test is performed many times continuously, the reproducibility of the test results is improved. In addition, the temperature and humidity are adjusted, and the air whose ozone concentration is adjusted is sent to the test tank at the above-mentioned circulating flow rate, whereby the stability of the ozone concentration in the test tank is further improved. These effects have the advantage that not only the reproducibility is improved but also the reliability of the test itself is increased.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a test apparatus configuration used for an ozone exposure test based on the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test tank 2 Flow meter (air flow meter) 3 Blower 4 Dehumidifier 5 Heating and humidifier 6 Ozone concentration controller 11 Ozone concentration measuring device 12 Ozone generator

Claims (6)

[Claims] 1. An ozone exposure test method, wherein a gas circulation flow rate in a test tank during an ozone exposure test is set to a flow rate per minute of 5 times or more the internal volume of the test tank, and a fluctuation of a gas circulation flow rate. The ozone exposure while controlling the gas circulation flow rate within a range of ± 10% of the set value of the gas circulation flow rate. 2. In the ozone exposure test method, the variation of the gas circulation flow rate in the test tank is controlled by the gas circulation flow rate set value ± 5%.
The ozone exposure test method according to claim 1, wherein the control is performed within the following range. 3. The ozone exposure test method according to claim 1, wherein the ozone concentration in the test tank is controlled within an ozone concentration set value ± 3% during the ozone exposure test. Test method. 4. The ozone exposure test method, wherein during the ozone exposure test, a gas adjusted to a constant temperature and a constant humidity is introduced into the test tank to adjust the inside of the test tank to a constant temperature and a constant humidity. The ozone exposure test method according to claim 1 or 2, wherein: 5. An ozone exposure test apparatus comprising: measuring a gas circulation flow rate in a test tank during an ozone exposure test;
An ozone exposure test device comprising a mechanism for adjusting a flow rate. 6. In the ozone exposure test, a gas circulation flow rate in the test tank during the ozone exposure test is measured,
The ozone exposure test method according to claim 1 or 2, wherein an apparatus having a mechanism for adjusting a flow rate is used.