JP4759096B2 - Permeability evaluation apparatus and evaluation method - Google Patents

Description

  The present invention relates to a permeability evaluation apparatus and an evaluation method for evaluating the permeation of gas or liquid in a film or a thin film.

  The plastic film is advantageous in that it is lighter in weight, superior in impact resistance, higher in flexibility, and lower in cost than a glass substrate. For this reason, in addition to being widely used for PET bottles and food packaging, in recent years, research and development of film-forming technology using plastic substrates has been promoted in the field of image display devices where glass substrates have been used. It has been.

  As a technical field where there is a high demand for a shift from a glass substrate to a plastic substrate, there are electronic paper, a solar cell device, and an organic EL, which are expected to be responsible for next-generation display devices. And for plastic films used in display devices such as organic EL devices, extremely low oxygen permeability and water vapor transmission that have never been achieved so as to maintain the characteristics of optical materials in the product and improve the reliability of the product. Sex is required.

However, for example, the measurement sensitivity with respect to the water vapor permeability of plastic films by the current measuring means (Non-Patent Documents 1 and 2) is about 1 ppm, and the water vapor permeability required for maintaining the performance of the display device and the like. The value is greatly exceeded. For this reason, due to practical requirements, there is an urgent need to improve measurement sensitivity for oxygen permeability and water vapor permeability of plastic films.
Therefore, in order to improve the measurement sensitivity for these permeability, an evaluation method using a mass analyzer as disclosed in Patent Document 1 and Patent Document 2 has been proposed. In the inventions described in these documents, the film to be measured is installed on the sample stage provided at the boundary between the component introduction tank and the vacuum tank, and the component to be evaluated such as water vapor is introduced into the component introduction tank. Perform mass spectrometry at Specifically, the evaluation target component is transmitted from the component introduction tank to the vacuum tank through the film to be measured, detected by mass spectrometry on the vacuum tank side, and the permeation amount is measured.

JP 2002-357533 A Japanese Patent Application Laid-Open No. 2005-233943

Japanese Industrial Standard JIS K 7129 Japanese Industrial Standards JIS Z 0208

However, according to the study by the present inventors, in these conventional techniques, since there is no consideration for the release of the water vapor component adsorbed on the inner wall of the apparatus, there is a problem that the measurement sensitivity is low due to an increase in the background. is there. In addition, there is a problem in that the reproducibility of the measurement is poor because the film to be measured may be distorted or damaged during measurement due to a pressure difference applied to both surfaces of the film to be measured. Due to the above-mentioned problems, these conventional methods can measure only the amount of water vapor transmission on the order of 10 ⁻⁴ g / m ² / day as shown below, and can satisfy the required measurement accuracy. It was not a thing. That is,
Sample area: 100 cm ² = 1 × 10 ⁻² m ²
Permeated water vapor amount (target accuracy): 1 × 10 ⁻⁶ g / m ² /day=1.16×10 ⁻¹¹ g / m ² /s=6.43×10 ⁻¹³ mol / m ² / s = 3. 87 × 10 ¹¹ molecules / m ² / s
Here, if the film having a sample area of 100 cm ² has water vapor transmission of 1 × 10 ⁻⁶ g / m ² / day, 1 × 10 ⁻² × 3.87 × 10 ¹¹ molecules / s = 3.87 × 10 ⁹ molecules / s = 1.46 × 10 ⁻¹¹ Pa · m ³ / s.
On the other hand, in the conventional measuring means as shown in FIG. 8, the amount of water vapor discharged from the inner wall (vacuum chamber) of the apparatus is 1 × 10 ⁻⁷ Pa · m ³ / m ² s, and the true surface area of the inner wall of the apparatus is 1 m. Assuming ² , the amount of water vapor released is 1 × 10 ⁻⁷ Pa · m ³ / s. Therefore, the real-time measurement of the water vapor permeability of the film, release gas from the inner wall of the apparatus becomes 10 ⁴ times the amount of permeated water, it is difficult to distinguish water release amount from the water permeate flow device inner wall.

A barrier film for a film device such as an organic EL display is required to have a water vapor permeability of about 10 ⁻⁶ g / m ² / day. On the other hand, as described above, the measurement sensitivity in the prior art is on the order of 10 ⁻⁴ g / m ² / day, and the measurement sensitivity is absolutely insufficient. For this reason, in the manufacturing process of the plastic film used for the display device, there is a serious practical problem that accurate quality control cannot be performed in terms of oxygen permeability and water vapor permeability. In addition to the problem of insufficient measurement sensitivity, the conventional method also has a problem of long measurement time.

  Therefore, the present invention solves the above-mentioned problems, can detect a very small amount of transmission component from a film below the measurement limit according to the prior art with high sensitivity, and can perform analysis accurately and accurately. An object is to provide an apparatus and a permeability treatment method.

The above object is achieved by the present invention described below. That is, the present invention is a permeability evaluation apparatus for performing an evaluation on the permeation component of the measured membrane (10),
The apparatus adsorbs a component to be evaluated by cooling provided at least in a chamber (15) having a permeation component introduction tank (11) and a permeation component passage tank (12) and a permeation component capture tank (51). Then, the adsorption / desorption base material (30) that desorbs the evaluation target component by stopping cooling or heating, the high vacuum exhaust device (73) for exhausting the inside of the tank (51), and the evaluation target component are analyzed. Analysis means (72) and a mechanism (80) for supplying an inert gas to at least the permeation component passage tank (12), the tank (11) and the tank in the chamber (15) (12), when the support jig (14) of the film (10) is disposed on the contact surfaces facing each other, and when the film (10) is supported by the support jig (14), Between one side of the membrane (10) and the inner wall of the tank (11) And the other surface of the membrane (10) and the inner wall of the tank (12), respectively, have a structure in which a sealed space is formed. 60) and an exhaust port (62) are provided, and the tank (12) allows the component to be evaluated to pass through the membrane (10) to be measured through the pipe having a valve. has a structure that can be moved to the 30), between the tank (12) the suction leaving group member (30), the transmitted component storage tank (13) is provided as needed, cistern (13 ), The tank (12) and the tank (13) are connected via a pipe having a valve or, if necessary, a pipe having a valve and a forced circulation fan, and the tank (13). ) And the substrate (30) are connected via a pipe having a valve,
The adsorbing / desorbing substrate (30) adsorbs the component to be evaluated by being cooled, and in the cooled state, the permeation component capturing tank (51) is evacuated by the high vacuum evacuation device (73), and then cooled. The component to be evaluated is desorbed by stopping or heating, and the analysis means (72) has a function of detecting the component to be evaluated desorbed from the substrate (30). There is provided a permeability evaluation apparatus characterized by comprising:

In the apparatus of the present invention, the analysis means (72) is any one of a mass spectrometer, a gas chromatography and a vacuum gauge; the chamber (15) can introduce an inert gas, and further adjusts the temperature and humidity. comprising means (70), it enables the adjustment of the temperature and humidity of the enclosed space of the transmission component introduction reservoir disposed within the chamber (15) (11); pre-Symbol support jig (14) A metal gasket or an elastomer gasket; provided with a moisture remover (91) for removing moisture in the inert gas; and the adsorption / desorption substrate (30) is a material having a large surface area Or a material having a high thermal conductivity is preferable.

The present invention also relates to a permeability evaluation method for evaluating a permeation component of a membrane to be measured , the method comprising a sampling step for sampling an evaluation target component that has permeated through the membrane to be measured , and a sample to be evaluated An adsorption and fixing step for adsorbing and fixing the components to the adsorption / desorption substrate; and an analysis step for analyzing the component to be evaluated. In the sampling step, two components are placed at positions facing each other across the film to be measured in the chamber. A component to be evaluated is supplied to one sealed space, an inert gas is supplied to the other sealed space, and a component to be evaluated in both sealed spaces. collected evaluated components by the partial pressure difference transmitted through the measuring film on one of the sealing space inert gas is supplied, in the vacuum fixing step, adsorbs evaluated components Rukoto cooled , Ru cooling is stopped Or heating is that the use of a suction leaving material capable of leaving the evaluated component in Rukoto and the evaluation target component taken above the absorbent detachable group material was cooled moved by circulation of the diffusion or gas After the component to be evaluated is adsorbed and fixed on the adsorption / desorption substrate and the adsorption / desorption substrate is cooled and evacuated , the cooling of the adsorption / desorption substrate is stopped or heated in the analysis step. The permeability evaluation method is characterized in that the analysis is performed by desorbing the component to be evaluated.

In the method, the evaluation component, water, oxygen, carbon dioxide, nitrogen, Ri ethylene gas or volatile organic compounds der, the adsorbed leaving material, the larger ones, or the thermal conductivity of the material of the surface area in analysis step, it uses one of the mass spectrometer, gas chromatography or gauge; Rukoto used as a large material prior to said collecting step, advance the two sealed space to remove water non It is preferable to substitute with active gas.

  ADVANTAGE OF THE INVENTION According to this invention, the trace amount water vapor permeability and oxygen permeability of various membranes can be measured accurately, accurately, and quickly.

The figure explaining the apparatus and method of this invention. And plots ion current against time of the mass spectrometer the mass 18Amu (corresponding to H ₂ O). The figure which shows the structure of the test piece 1 and the test piece 2 which were used for the test. The figure explaining the relationship between a pressure change and the amount of water vapor transmission. The figure which calculated the water vapor transmission rate from the pressure change shown in FIG. The figure explaining the relationship between a pressure change and the amount of water vapor transmission. The figure which calculated water vapor | steam transmission | permeation amount from the pressure change shown in FIG. The figure which shows a well-known water vapor permeability measuring apparatus.

  Next, the present invention will be described in more detail with reference to preferred embodiments. First, the basic configuration of the apparatus of the present invention will be described with reference to FIG.

<Permeability evaluation device>
The apparatus of the present invention is a permeability evaluation apparatus that performs an evaluation on the permeability of a very small amount of water vapor, oxygen, or the like on a film to be measured 10 such as a plastic film.
The apparatus of the present invention has at least a chamber 15 having a permeation component introduction tank 11 and a permeation component passage tank 12, and an adsorption desorption that adsorbs the evaluation target component by cooling and desorbs the evaluation target component by stopping cooling or heating. The separation substrate 30, an analysis means 72 for analyzing the evaluation target component, and a mechanism 80 for supplying at least the inert gas to the permeation component passage tank 12 are provided. Although the cooling in the above varies depending on the component to be evaluated, for example, liquid nitrogen (77K), liquid helium (4K), or the like is preferably used as a refrigerant and is performed at an extremely low temperature.

  In the tank 11 and the tank 12 in the chamber 15, a support jig 14 for the film to be measured 10 is disposed on the contact surfaces facing each other. When the film to be measured 10 is supported by the support jig 14, between one surface of the film 10 and the inner wall of the tank 11 and between the other surface of the film 10 and the inner wall of the tank 12. Each has a structure in which a sealed space is formed. By having such a structure, when an evaluation target component is introduced into a sealed space formed between the inner wall of the permeation component introduction tank 11 and one surface of the film to be measured 10, this is not lost. Can be used for evaluation.

The component introduction tank 11 includes at least an introduction port 60 and an exhaust port 62 for a component to be evaluated. The introduction port 60 and the exhaust port 62 are preferably connected to pipes (41, 42) each having a valve. On the other hand, the permeation component passage tank 12 has a structure capable of supplying the component to be evaluated that has permeated through the film to be measured 10 to the adsorption / desorption substrate 30 through a pipe having a valve.
As the adsorption / desorption base material 30, a substrate that adsorbs the evaluation target component by being cooled and desorbs the evaluation target component by being cooled or heated. The evaluation target component that has passed through the measurement target film 10 is adsorbed and collected by cooling the adsorption / desorption substrate 30. When the permeated evaluation target component is adsorbed, the valve is closed, and then the adsorption / desorption substrate 30 is stopped or heated to desorb the permeated evaluation target component and analyze the total amount. Means 72 can be provided.

As the analysis means 72, one having a function of detecting the evaluation target component detached from the base material 30 is used. Examples of such analysis means include a mass spectrometer, gas chromatography, or vacuum gauge.
When using analysis means 72 that requires evacuation, such as a mass spectrometer, an ultra-high evacuation device 73 is installed as appropriate.

The inert gas supply mechanism 80 supplies an inert gas to at least the permeation component passage tank 12. By replacing the tank 12 with an inert gas that does not contain the evaluation target component, the evaluation target component permeates the membrane 10 due to the difference in partial pressure of the evaluation target component while the tank 11 and the tank 12 are at the same pressure. Since evacuation of the tank 12 is not required, damage to the apparatus and the film 10 can be reduced and the reproducibility of the measurement result can be improved.
As a further configuration of the inert gas supply mechanism 80, an inert gas tank 87 filled with an inert gas, and inert gas supply pipes 82 and 84 connecting the tank 87 and the chamber 15, and the tank 87 and the tank 13 are given. Can do. These tubes preferably comprise valves. By providing the mechanism 80 with a moisture remover 91 to remove moisture in the inert gas and then supplying it to the apparatus of the present invention, the reproducibility of the measurement can be further improved.
As the inert gas, it is preferable to use a rare gas such as helium, neon, or argon in addition to the nitrogen gas.
By replacing the entire apparatus of the present invention with an inert gas before the start of measurement, it is possible to remove oxygen, moisture, etc. adhering to or remaining in the inner wall of the apparatus, and to remove measurement obstruction factors Can do. In addition, by introducing an inert gas into the chamber 15 and keeping the pressure in the chamber and the tanks 11 and 12 inside thereof equal, stress concentration on the support jig 14 and the like is avoided, and the measurement results are reproduced. Can be improved, and damage to the device can be reduced. The pressure of the tanks 11 and 12 at the time of measurement is not particularly limited as long as it is equal, but by setting the atmospheric pressure to be the same as the external pressure, the stress applied to the apparatus can be minimized and labor for exhaust can be saved. Therefore, it is preferable.

  In the apparatus of the present invention, the chamber 15 preferably further includes a temperature / humidity adjusting means 70. By adjusting the temperature and humidity in the chamber 15 and adjusting the temperature in the tanks 11 and 12 indirectly, the sensitivity of a very small amount of transmitted components from the film to be measured under a desired temperature and humidity condition is good. Detection is possible. In addition, by making the temperature and humidity in the tanks 11 and 12 and the chamber 15 outside thereof equal, the temperature and humidity gradients are eliminated and the measurement can be performed under stable conditions, so that the reproducibility of the measurement results is improved. Can do.

Furthermore, as shown in FIG. 1, it is also one of the preferable embodiments of the apparatus of the present invention to provide a permeated component storage tank 13 between the permeated component passage tank 12 and the adsorption / desorption substrate 30. The tank 12 and the tank 13 are connected via a pipe having a valve. Furthermore, you may connect the said tank 12 and the tank 13 by piping provided with the valve | bulb and the forced circulation fan 21 as needed. The forced circulation fan 21 is useful for sending the component to be evaluated that has passed through the membrane 10 from the tank 12 to the tank 13. During the permeation of the evaluation target component, the permeate concentration in the tank 12 and the tank 13 is kept constant by opening the valve of the pipe and forcibly circulating the gas in the tank 12 and the tank 13 with the circulation fan 21. be able to.
Further, when the base material 30 is cooled, the gas contracts and the inside of the apparatus is depressurized. Therefore, if the tank 12 and the base material 30 are connected, the film 10 may be deformed or damaged by repeated measurement. In addition, the processed portion such as a barrier coating film of the film may be damaged. By connecting the tank 13 and the cooled base material 30 before the apparatus of the present invention is provided with the tank 13 or before cooling the base material 30, by closing the valve between the tanks 12 and 13, It is preferable because both sides of the film 10 can be maintained at an equal pressure (for example, atmospheric pressure) and the film 10 can be protected from damage.
Examples of the forced circulation fan 21 include a heat-bakable fan or a diaphragm pump.

  It is preferable to use the support jig 14 that does not impair the sealing performance even after repeated use over a long period of time. Examples of the support jig 14 that can be suitably used in the apparatus of the present invention include a metal gasket and an elastomer gasket. As the metal gasket base material, for example, copper, stainless steel, aluminum alloy, titanium alloy, silver alloy, or indium alloy can be used.

In the apparatus of the present invention, it is preferable to provide the adsorption / desorption base material 30 in the permeation component capturing tank 51. By setting it as such a structure, adsorption | suction and desorption | desorption of the evaluation object component to the base material 30 can be equalize | homogenized, and the reproducibility of a measurement can be improved. Examples of the cooling means for the base material 30 include a structure in which a refrigerant container 52 of liquid nitrogen or the like is installed and a tank 51 containing the base material 30 is immersed in the refrigerant container 52. In this case, a material that has high thermal conductivity and can withstand low temperatures is used as the material for forming the tank 51. The present invention is not limited to the above configuration, and the base material 30 itself can be sufficiently cooled by a refrigerant such as liquid nitrogen. By cooling, the evaluation target component is adsorbed on the base material 30, and the cooling is stopped. Any method may be used as long as the structure to be evaluated is desorbed.
Further, the movement of the permeated evaluation target component from the tank 12 or the tank 13 to the base material 30 may be diffusion by opening a valve, but a pipe 32 having a circulation fan is installed in the tank 51. The gas may be circulated at atmospheric pressure using the pipe. In this way, the component to be evaluated from the tank 12 or the tank 13 can be adsorbed to the base material 30 more efficiently.

  As the adsorption / desorption base material 30, it is preferable to use a material having a large surface area or a material having a high thermal conductivity. The material of the adsorption / desorption base material 30 that is preferably used in the apparatus of the present invention is determined according to the component to be evaluated and cannot be generally specified. For example, zeolite, activated carbon, an aluminum honeycomb structure, a copper honeycomb Mention may be made of foam metals such as structures and porous stainless steel.

  The cooling temperature of the adsorption / desorption substrate 30 also depends on the evaluation target component to be adsorbed and cannot be generally stated, but is set to, for example, a liquid nitrogen temperature (−196 ° C.) or lower. Since liquid nitrogen is inexpensive, the measurement can be performed economically. According to the study by the present inventors, when the component to be evaluated is water vapor, the adsorption / desorption substrate is cooled to the liquid nitrogen temperature to adsorb moisture, and then the inside of the permeation component capturing tank 51 is cooled. It was found that even if the gas in the tank was removed by evacuation, the water adsorbed on the substrate hardly sublimated and was not lost. Furthermore, the water | moisture content adsorb | sucked to the base material is sublimated rapidly by stopping cooling or heating a base material. As a result, the amount of water adsorbed on the base material 30 by liquid nitrogen cooling can be accurately quantified, and accurate evaluation becomes possible.

In the apparatus of the present invention, the materials constituting the tanks 11, 12, 13, 51, the chamber 15, the support jig 14, and the pipe having the valve have a gas release rate of 1 × 10 when the temperature of the base material 30 is raised. It is preferable to use a material having a pressure of ⁻⁹ Pa · m ³ / m ² s or less. Examples of such materials include copper, stainless steel, aluminum alloy, titanium alloy and silver alloy.

<Permeability evaluation method>
Next, the permeability evaluation method of the present invention will be described with reference to FIG. The permeability evaluation method of the present invention can be carried out using the permeability evaluation apparatus of the present invention having the configuration shown in FIG.
The method includes a sampling step for sampling at least the evaluation target component that has permeated through the measured film 10, an adsorption fixing step for adsorbing and fixing the collected evaluation target component to the adsorption / desorption base material 30, and the adsorption fixation An analysis step of desorbing the component to be evaluated from the substrate 30 and analyzing it;
In the sampling step, first, the film to be measured 10 is sandwiched between the permeation component introduction tank 11 and the permeation component passage tank 12 to form two sealed spaces that sandwich the film 10. Next, the component to be evaluated is introduced into the sealed space on the permeable component introduction tank 11 side, the inert gas is introduced into the sealed space on the permeable component passage tank 12 side, and both sealed spaces are brought to the same pressure. Next, by closing all the valves of the pipes connected to the tanks 11 and 12 for a certain period of time, the evaluation target component permeates the membrane 10 due to the difference in partial pressure between the evaluation target components in the tanks 11 and 12, The transmitted evaluation target component accumulates in the tank 12. The holding time for the permeation varies depending on the permeability of the membrane 10 and the component to be evaluated, and cannot be generally specified, but is, for example, 1 to 20 hours. In the conventional method performed in a vacuum state, the holding time for transmission may be about 40 hours, and considering that the measurement sensitivity has not reached the desired level, the present invention is Even holding time alone is epoch-making and its practical value is extremely high. While the component to be evaluated is permeated through the membrane, all the valves of the pipes connected to the tanks 11 and 12 may be closed and held, or the valves of the pipes 20 and 22 may be opened to circulate the gas between the tanks 13 and 13. Good.
The pressure in the tanks 11 and 12 is not particularly limited as long as the pressure is the same, but the labor of exhaust can be saved and the generation of stress on the film 10 due to the occurrence of differential pressure with the outside can be prevented. It is preferable to use atmospheric pressure.

In the adsorption fixing step, the adsorption / desorption substrate 30 is cooled to adsorb the evaluation target component on the substrate. This adsorption may be by diffusion. However, as described above, the gas containing the component to be evaluated is circulated and brought into contact with the base material 30, whereby the adsorption can be performed more efficiently. In the adsorption and fixing step, a small amount of plasticizer and oil released from the membrane 10 are also adsorbed and fixed, but can be detected separately as described later.
The time during which the evaluation target component is adsorbed on the base material 30 varies depending on the amount of the evaluation target component that has passed through the film 10 and the nature of the base material 30, but may normally be about 10-30 minutes.

Next, in the analysis step, the cooling of the base material 30 is stopped or heated to raise the temperature of the base material, and the evaluation target component adsorbed on the base material is desorbed. The temperature of the substrate 30 is preferably increased so that the gas release rate is 1 × 10 ⁻⁹ Pa · m ³ / m ² s or less. Further, the temperature rise is preferably performed so that the total amount of the evaluation target component adsorbed on the substrate 30 is desorbed in 5 to 60 minutes, and more preferably desorbed in 5 to 30 minutes.
When the analysis means needs to be evacuated like a mass spectrometer, the analysis step needs to be performed after the substrate 30 or the tank 51 is evacuated, but when using an analysis means that does not require evacuation, The desorbed evaluation target component may be moved to the analysis means together with the inert gas.

The analysis of the component to be evaluated desorbed from the base material 30 is preferably performed simultaneously with the temperature rise of the base material 30. Assuming that the time of the sampling step for bringing the component to be evaluated into contact with the membrane 10 and permeating the membrane is X, and the time for raising the temperature to desorb the total amount of the component to be evaluated adsorbed on the substrate 30 is Y. In this evaluation method, the evaluation target component having a concentration X / Y times that of the conventional method of analyzing the evaluation target component while evacuating is used for detection. For example, when the sampling process X is 10 hours and the temperature rising time Y is 15 minutes, the evaluation target component having a concentration 40 times that of the conventional method is provided for the analysis process. Further, the evaluation target component is not uniformly desorbed in the temperature rising process of the substrate 30, but desorbs with a specific peak (holding time) as in the chromatographic analysis (see FIG. 2). For this reason, a highly sensitive measurement with a large S / N ratio can be performed. Further, it is possible to distinguish and detect a trace amount of plasticizer or oil released from the film 10 based on the difference in holding time and the component to be evaluated. For this reason, due to the synergistic effect of the concentration of the evaluation target component and the improvement of the S / N ratio, the measurement method of the present invention can perform the permeability evaluation with remarkably superior sensitivity as compared with the conventional method. When the evaluation target component is water vapor, the measurement sensitivity of the water vapor transmission amount can be increased to about 10 ⁻⁶ g / m ² / day.

The analysis is preferably performed using any one of a mass spectrometer, a gas chromatography, and a vacuum gauge.
As said evaluation object component, water, oxygen, a carbon dioxide, nitrogen, ethylene gas, or a volatile organic compound can be mentioned.
In the evaluation method of the present invention, it is preferable that the two sealed spaces are replaced with an inert gas that has been dried and removed in advance before the sampling step. As a result, oxygen, moisture, or the like attached to or remaining in the inner wall of the apparatus can be removed, and a factor that hinders measurement can be removed.

In the permeability evaluation method of the present invention, the inside of the chamber 15 is hermetically sealed and the inside of the chamber 15 is always evacuated or a gas not containing the evaluation target component is allowed to flow and circulate in the chamber 15. Even when there is an airtight leak between 10 and the tank 11 or between the film 10 and the tank 12, the influence on the measurement result can be suppressed to a minimum.
In the adsorption fixing step, by closing the valve and disconnecting the gas between the base material 30 and the membrane 10, it avoids the occurrence of a differential pressure on both sides of the membrane 10 due to the cooling of the gas, and damages the membrane 10. Can be prevented. Specifically, it is preferable to disconnect communication between the tanks 12 and 13 close to the membrane 10.

<Permeability evaluation target>
Examples of the film to be measured 10 to be evaluated for permeability in the present invention include plastic films for packaging such as foods, pharmaceuticals, and precision instruments, and barrier films for various device elements. Examples of the material for the plastic film include PET (polyethylene terephthalic acid), PC (polycarbonate), PES (polyether sulfone), and COP (cycloolefin polymer). An example of the area of the film to be measured 10 through which the evaluation target component permeates can be 10 cm ² . In the measuring apparatus of the present invention, since the film to be measured 10 is sandwiched by the support jig 14, the film to be measured 10 having various thicknesses can be accommodated, and the film thickness is not particularly limited. it can.

<Usage example>
Next, the apparatus and method of the present invention will be described with reference to FIG. 1, taking as an example the case where the component to be evaluated is water vapor. In the apparatus of the present invention, water vapor that is a component to be evaluated is supplied to the tank 11. The water vapor is supplied from the evaluation target component storage tank 40 to the tank 11 through the pipe 41 having a valve and is circulated through the exhaust port 62, and the inside of the tank 11 is filled with water vapor saturated or at a predetermined partial pressure. . The opening of the tank 12 is in contact with the opening of the tank 11, and a support jig 14 for the film 10 is provided at these contact parts, and the film 10 is formed by the support jig 14. Supported in an airtight state.

  A tank 12 is provided opposite to the tank 11 through the membrane 10, and the inside of the tank 12 is replaced with a high-purity inert gas supplied from an inert gas tank 87, and the same pressure as the tank 11 (for example, 1 atm). Further, the high purity inert gas is also supplied into the chamber 15 in which the tanks 11 and 12 are housed, so that the water vapor in the tank 11 does not enter the tanks 11 and 12 and the like from portions other than the film 10. ing.

  By closing the valves of the pipes 20 and 22 and leaving them in the above state for a predetermined time (for example, 1 to 12 hours), the water vapor permeates the membrane 10 due to the difference in the water vapor partial pressure in the tank 11 and the tank 12. 12 accumulates. After a predetermined time (for example, 1 to 12 hours), the valves 20 and 22 are opened, the forced circulation fan 21 is operated, and the water vapor accumulated in the tank 12 is guided into the tank 13. Alternatively, the valves of the tubes 20 and 22 are opened, and the gas in the tank 12 and the tank 13 is forcedly circulated using a heat-bakable fan or a diaphragm pump, and the gas is allowed to pass for a predetermined time (for example, 1 to 12 hours). Water vapor may be accumulated in the tank 12 and the tank 13.

Next, the valves of the pipes 20 and 22 are closed, and the gas exchange between the tank 12 and the tank 13 is cut off while keeping the film to be measured 10 at atmospheric pressure. The water vapor in the tank 13 is sent by diffusion to a water vapor capturing tank 51 having a cooling means 52 (for example, a liquid nitrogen container), and is provided in the tank 51 by waiting for a predetermined time (for example, 10 to 30 minutes). Water vapor is adsorbed and fixed by the water vapor adsorption / desorption substrate 30. At this time, organic components such as a small amount of plasticizer and oil released from the film 10 are also adsorbed and fixed. In this state, the inside of the tank 51 is evacuated (for example, 10 ⁻⁵ Pa) by the ultra-high vacuum exhaust device 73 via the pipe 71 having a valve, thereby removing the inert gas existing in the tank 51. .

  After the ultra-high vacuum exhaust, the water adsorbed on the adsorption / desorption substrate 30 is vaporized by stopping the cooling with liquid nitrogen or heating the tank 51 at a constant temperature with a heater (not shown). The water vapor partial pressure of the vaporized water vapor is detected by the mass spectrometer 72, and the detection result is analyzed by the computer 90. Based on the analysis result, the water vapor permeability of the membrane 10 is calculated and evaluated.

Next, the present invention will be described more specifically with reference to examples.
<Example 1>
The permeability evaluation method of the present invention will be specifically described with reference to FIG. 1 showing the apparatus of the present invention. In this embodiment, as the film to be measured 10, a test piece (provided by Oike Kogyo Co., Ltd.) whose water vapor permeability is measured to be 5.3 × 10 ⁻³ g / m ² / day in an existing apparatus is used. Used as.

A test piece as the film to be measured 10 was sandwiched and fixed between the contact portions of the tank 11 and the tank 12 of the permeability evaluation apparatus of the present invention. The area of the surface where the test piece comes into contact with the gas in the tank 11 is about 10 cm ² . In addition, a supporting jig 14 made of Viton (registered trademark), which is an elastomer, is provided at a contact portion between the tank 11 and the tank 12, and this is in close contact with and supports the test piece.
Subsequently, the inside of the tank 12, the tank 13, and the chamber 15 was replaced with an inert gas. After that, the tank 11 was filled with saturated water vapor (1 atm), the inside of the tank 12 was maintained at 1 atm, and left for 15 hours while circulating with the tank 13. After 15 hours, the valves 20 and 22 were closed to prevent gas movement with the tank 12, and then the water vapor in the tank 13 was adsorbed to the adsorption / desorption substrate 30 in the tank 51 for 30 minutes. At this time, the tank 51 is installed in a liquid nitrogen container as the cooling means 52 and is cooled to the liquid nitrogen temperature. In addition, as the base material 30, the porous stainless steel material for air filters made from Swagelok was used. After completion of the adsorption for 30 minutes, the valve of the pipe 50 was closed, the valve of the pipe 71 was opened, and the inert gas was exhausted by the ultra-high vacuum exhaust device 73 for 20 minutes.

  By removing liquid nitrogen from the liquid nitrogen container 52, the water vapor partial pressure was detected by the mass spectrometer as the analyzing means 72 while raising the temperature of the substrate 30, and the detection result was analyzed by the computer 90. It was confirmed by the measurement of the thermocouple thermometer attached to the tank 51 that the temperature of the tank 51 rose at a constant heating rate (12 ° C./min) from −169 ° C. to −100 ° C.

FIG. 2 shows the result of plotting the output (ion current, unit: pA) of the mass 18 amu (corresponding to H ₂ O) of the mass spectrometer (Anelva QIG-066) against time. FIG. 2 shows that a signal indicating a clear water peak is obtained. The reason why the peak shape is different from the theoretical shape is considered to be due to uneven temperature during heating in the tank 51 having a stainless outer wall, but it can be improved by using copper having excellent heat conduction. .

The peak intensity is sufficiently large with respect to the background, and the transmission time of 15 hours used in this example is considered to be too much for the film to be measured used in this example. . The background variation is less than 8 × 10 ⁻¹³ A, and the intensity of the peak minus the background is 2 × 10 ⁻¹¹ A or more. Therefore, the signal of about 1/250 of this example, that is, 2 × It can be seen that the sensitivity of 10 ⁻⁵ g / m ² / day can be measured with this apparatus in 15 hours.

  The background signal decreases with time because of the effect that the water vapor adsorbed on the container is exhausted by the pump. The vacuum piping used in this example is made of stainless steel. By using a material with less water vapor adsorption than stainless steel, it is easy to lower the background to 1/100.

From the above, it is possible to measure the water vapor transmission rate of 1 × 10 ⁻⁶ g / m ² / day (1/20 of this example) in about 3 hours (1/5 of the example) by the method of the present invention. It was shown that. Furthermore, it was possible to measure with high accuracy even by repeated measurement.

<Example 2>
In this example, as the film to be measured 10, a barrier film having a configuration described in JP 2007-134099 A was formed on a polyester film as a test piece. FIG. 3 shows the configuration of the test piece used in the test. The test piece 1 is formed by alternately forming seven layers of polyurea and alumina, and the test piece 2 is formed by forming eleven layers of polyurea and alumina alternately.

The test piece 1 was used as the film 10 to be measured, and the water 10 was exposed to the water vapor in the tank 51 and the time for permeation was reduced from 15 hours to 3 hours. Adsorbed to the tank 51.
Thereafter, the liquid nitrogen is removed from the liquid nitrogen container 52, and the water vapor partial pressure is detected by the mass spectrometer 72 while the temperature of the tank 51 is increased at a constant rate (10 ° C./min), and the detection result is analyzed by the computer 90. did. As a result, the water vapor permeability of the test piece 1 was 5.6 × 10 ⁻³ g / m ² / day.

<Example 3>
When the measurement was performed in the same manner as in Example 2 except that the test piece 2 was used as the film to be measured 10, the water vapor permeability was 5 × 10 ⁻⁶ g / m ² / day.
The measurements of Examples 2 and 3 were highly sensitive and reproducible. The measurement time could be performed within about 3 hours. On the other hand, the conventional measurement required several days of measurement.

<Comparative Example 1>
The water vapor permeability of the test piece 1 was measured using a known permeability evaluation apparatus having the configuration shown in FIG. In the apparatus shown in FIG. 8, the permeated component introduction tank 11 is a high-temperature and high-humidity tank, and the film to be measured 10 is installed at the boundary with the vacuum tank 92.
First, the tank 92 was evacuated and the water vapor partial pressure in the tank was measured to be 3.39 × 10 ⁻⁶ Pa. Next, dry nitrogen was humidified by the humidifying means 93 and introduced into the tank 11, thereby introducing water vapor into the tank 11. The water vapor partial pressure in the vacuum chamber 92 after 80 minutes from the introduction of water vapor was 3.51 × 10 ⁻⁶ Pa. When the water vapor transmission rate is calculated from the pressure change shown in FIG. 4, it is 5.7 × 10 ⁻³ g / m ² / day as shown in FIG. The display of the partial pressure gauge has two digits after the decimal point. When the measurement limit is obtained from the change in partial pressure, it becomes 5 × 10 ⁻⁴ g / m ² / day, which is consistent with the measurement limit of a commercially available water vapor permeability meter. In this example, the measurement accuracy was poor and the error was large.

<Comparative example 2>
Water vapor permeability was measured in the same manner as Comparative Example 1 except that the test piece 2 was used in place of the test piece 1 as the film to be measured 10. Vacuum chamber partial pressure of steam before the steam introduced is 3.42 × 10 ^-6 Pa, the vacuum chamber the water vapor partial pressure at 80 minutes after the steam introduction 3.42 × 10 ^-6 Pa next pressure changes observed It was. This indicates that the water vapor transmission rate of the test piece 2 is 5 × 10 ⁻⁴ g / m ² / day or less.

<Comparative Example 3>
The water vapor transmission rate was measured in the same manner as in Comparative Example 1 except that the substrate film used for the test pieces 1 and 2 was used in place of the test piece 1 as the film 10 to be measured. The water vapor partial pressure in the vacuum chamber before the introduction of water vapor was 3.22 × 10 ⁻⁶ Pa, and the water vapor partial pressure in the vacuum chamber after 80 minutes from the introduction of water vapor was 1.47 × 10 ⁻⁴ Pa. When the water vapor permeation amount of the test pieces 1 and 2 is calculated from the pressure change shown in FIG. 6, it is 7 g / m ² / day as shown in FIG.

  According to the present invention, water vapor permeability and oxygen permeability of various membranes can be measured with high accuracy and efficiency.

10: film to be measured 11: permeation component introduction tank 12: permeation component passage tank 13: permeation component storage tank 14: support jig 15: chamber 20, 22: pipe having valve 21: forced circulation fan 30: adsorption / desorption substrate 32: Pipe having a circulation fan 40: Evaluation target component storage tanks 41, 42, 50: Pipe having a valve 51: Permeated component trapping tank 52: Cooling means 60, 64, 66, 68: Inlet 62, 69: Exhaust 70 : Temperature adjusting means 71, 81 to 86: Pipe 72 having a valve 72: Analyzing means 73: Ultra-high vacuum exhaust device 80: Inert gas supply mechanism 87: Inert gas tank 90: Computer 91: Moisture remover 92: Vacuum tank 93 : Humidifying means 94: Humidity sensor 95: Exhaust means 96: Sample stand

Claims (8)

A permeability evaluation apparatus for evaluating a permeation component of a film to be measured (10),
The apparatus adsorbs a component to be evaluated by cooling provided at least in a chamber (15) having a permeation component introduction tank (11) and a permeation component passage tank (12) and a permeation component capture tank (51). Then, the adsorption / desorption base material (30) that desorbs the evaluation target component by stopping cooling or heating, the high vacuum exhaust device (73) for exhausting the inside of the tank (51), and the evaluation target component are analyzed. Analyzing means (72) for carrying out, and a mechanism (80) for supplying an inert gas to at least the permeation component passage tank (12),
In the tank (11) and the tank (12) in the chamber (15), a support jig (14) of the film (10) is disposed on the contact surfaces facing each other, and the support jig ( 14), when the membrane (10) is supported, between the one surface of the membrane (10) and the inner wall of the tank (11) and the other surface of the film (10) and the tank (12). Each has a structure in which a sealed space is formed between the inner wall and
The tank (11) is provided with an introduction port (60) and an exhaust port (62) for components to be evaluated,
The tank (12) has a structure capable of moving the evaluation target component that has passed through the measurement target membrane (10) to the adsorption / desorption substrate (30) through a pipe having a valve.
When the permeation component storage tank (13) is provided between the tank (12) and the adsorption / desorption substrate (30) as necessary, and the tank (13) is provided, the tank (12) and the tank (13) is connected through a pipe having a valve or, if necessary, through a pipe having a valve and a forced circulation fan, and the tank (13) and the substrate (30) have a valve. Connected through piping,
The adsorbing / desorbing substrate (30) adsorbs the component to be evaluated by being cooled, and in the cooled state, the permeation component capturing tank (51) is evacuated by the high vacuum evacuation device (73), and then cooled. Is eliminated or the component to be evaluated is desorbed by heating,
The permeability evaluation apparatus, wherein the analysis means (72) has a function of detecting an evaluation target component detached from the base material (30).   The permeability evaluation apparatus according to claim 1, wherein the analysis means (72) is one of a mass spectrometer, a gas chromatography, and a vacuum gauge.   The chamber (15) can introduce an inert gas, and further includes a temperature and humidity adjusting means (70). The temperature of the sealed space of the permeation component introduction tank (11) disposed in the chamber (15) and The permeability evaluation apparatus according to claim 1 or 2, wherein the humidity can be adjusted.   The permeability evaluation apparatus according to any one of claims 1 to 3, wherein the support jig (14) is made of a metal gasket or an elastomer gasket.   The permeability evaluation apparatus according to any one of claims 1 to 4, further comprising a moisture remover (91) for removing moisture in the inert gas. A permeability evaluation method for evaluating a permeation component of a membrane to be measured,
The method includes a collecting step for collecting the evaluation target component that has passed through the measurement target film, an adsorption fixing step for adsorbing and fixing the collected evaluation target component to the adsorption / desorption base material, and an analysis step for analyzing the evaluation target component And
In the sampling step, two sealed spaces are formed at positions facing each other across the film to be measured in the chamber, and the component to be evaluated is added to one sealed space so that both sealed spaces have equal pressure. An inert gas is supplied to one sealed space, and the sealed target to which the inert gas is supplied is the evaluation target component that has passed through the measured film due to the difference in partial pressure of the evaluated target component in both sealed spaces. Gather in space,
In the adsorption / fixing step, the component to be evaluated is adsorbed by being cooled, and the cooled / desorbed substrate is used to desorb the component to be evaluated by being cooled or heated. The component to be evaluated collected above is moved to the adsorption / desorption substrate by diffusion or gas circulation, and the component to be evaluated is adsorbed and fixed on the adsorption / desorption substrate, and the adsorption / desorption substrate is cooled and vacuumed. After exhausting
In the analyzing step, the permeability evaluation method is characterized in that the analysis is performed by desorbing the component to be evaluated by stopping cooling or heating the adsorption / desorption substrate. The permeability evaluation method according to claim 6 , wherein any one of a mass spectrometer, a gas chromatography, and a vacuum gauge is used in the analysis step. The permeability evaluation method according to claim 6 or 7 , wherein the two sealed spaces are replaced with an inert gas from which moisture has been removed in advance before the sampling step.

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