JP2010210323A - Gas permeability measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas permeability measuring device capable of measuring easily and surely a permeability of gas such as oxygen or steam of a gas barrier film, in a state where tensions are applied to a film-shaped sample in in-plane, in all directions. <P>SOLUTION: This gas permeability measuring device includes: a container 1; a sealing means for sealing airtightly the container 1 by allowing the film-shaped sample 2 placed on a sample placing section 4 of the container 1 so as to cover an opening 5 to adhere onto the sample-placing section 4; a gas supply means for supplying gas or steam onto the outer surface of the film-shaped sample 2; and a measuring means for measuring the amount of gas or steam entering the container 1 through the film-shaped sample 2. The device includes a tension application means for applying onto the film-shaped sample 2, a tension for pulling from the center of the container 1 toward the outside, in plan view. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring gas permeability of, for example, water vapor and gas of a plastic film or a sheet-like sample.

  Gas barrier films that block the permeation of oxygen and water vapor by forming a barrier thin film such as silicon oxide, aluminum oxide, or aluminum on the surface of plastics are attracting attention as packaging materials for foods, drugs, electronic materials, and the like. In recent years, gas barrier films have come to be used in flexible liquid crystal display elements and EL display elements using plastic substrates.

  Conventional gas permeability evaluation includes a cup method (see Non-Patent Document 1), a mocon method (see Non-Patent Document 2), and the like. Recently, a method using calcium corrosion has been proposed as a method for measuring high water vapor barrier permeability (see, for example, Patent Document 1). In either method, the transmittance is measured by carefully setting the sample film so that tension is not applied to the sample film as much as possible.

JP-A-2005-181300

JIS Z 0208 JIS K 7129 B method J. T. Felts, “Transparent Barrier Coatings Update: Flexible Substrates”, Society of Vacuum Coaters 36th Annual Thechnical Conference Proceedings, 25-30, 1993.

  However, as described above, the gas barrier film is used as a packaging material for various products, and in the situation where it is used, tension such as tension and bending frequently acts on the barrier film. In addition, since a flexible display element displays in a deformed state, it is necessary to maintain gas barrier performance in a state where tension is generated.

  When the tension acting on the gas barrier film is equal to or greater than the strength value of the barrier thin film, cracks are generated in the film and the barrier performance is greatly deteriorated. Therefore, it is very important to know the tension limit value that can maintain the barrier performance. Further, scratches are latent in the actual barrier film, and even if the tension is within the limit value, it is considered that the scratches are opened by the tension and the barrier property is lowered. Therefore, it is important for examining the barrier properties in actual use to measure and evaluate not only the permeability in an unloaded state but also the gas barrier performance in a state where tension is applied.

  As a method of measuring oxygen permeability while applying tension to the gas barrier film, a large tension stage that pulls the film sample in a uniaxial direction is provided outside the gas measurement cell, and the sample is pulled to a predetermined tensile rate in advance. A method of setting in a gas cell has been reported (for example, see Non-Patent Document 3). However, this method has a problem that only a uniaxial tension can be imposed and the apparatus becomes large. Since the tension acting on the gas barrier film is in various directions, it is important to measure the transmittance in a state where the tension is imposed in all directions in the plane.

  The present invention solves the above-described problems, and allows gas permeability measurement such as oxygen and water vapor in gas barrier films to be easily and reliably measured in a state where tension is applied to the film sample in all in-plane directions. An object is to provide an apparatus.

  In order to achieve the above object, the present invention as claimed in claim 1 is characterized in that a sample mounting portion provided with an upper end being opened and extending outwardly in a circular plate shape around the periphery of the opening. And a sealing means that hermetically seals the inside of the container by bringing the film-like sample placed on the upper surface of the sample placement unit so as to cover the opening into close contact with the upper surface of the sample placement unit Gas supply means for supplying gas or water vapor to the outer surface of the film-like sample opposite to the inside of the container, and the film-like sample provided in the container permeates the film-like sample and enters the container. A gas permeability measuring device comprising a measuring means for measuring the amount of the gas or water vapor coming, and applying a tension to the film-like sample to give a tension that is pulled outward from the center of the container when viewed in plan. Means are provided And wherein the Rukoto.

  According to a second aspect of the present invention, there is provided the gas permeability measuring apparatus according to the first aspect, wherein the tension applying means is formed to extend in an annular shape so as to surround the opening on the upper surface of the sample mounting portion. A groove, a tension applying member that pushes a portion of the film-like sample located on the tension applying groove into the tension applying groove and applies the tension to the film-like sample, and the tension applying member is the tension. It is characterized by including a pushing mechanism that pushes into the application groove.

According to a third aspect of the present invention, in the gas permeability measuring device according to the second aspect, the cross-sectional shape cut by a plane orthogonal to the extending direction of the tension applying groove is a concave semicircular shape, The member has an annular shape, and the portion where the tension applying member engages with the tension applying groove is formed as a protruding strip portion having a semicircular shape with a sectional shape cut by a plane orthogonal to the extending direction. It is characterized by.
According to a fourth aspect of the present invention, there is provided the gas permeability measuring apparatus according to the second aspect, wherein the push-in mechanism is detachably provided on the sample mounting portion, and the tension is provided on the support member. It is characterized by including the adjustment member which adjusts the pressing force of the said tension | tensile_strength provision member with respect to the groove | channel for work.
According to a fifth aspect of the present invention, in the gas permeability measuring apparatus according to the second or third aspect, an elastically sealable material that maintains airtightness with the tension applying member is disposed in the tension applying groove. It is characterized by being.

A sixth aspect of the present invention is the gas permeability measuring apparatus according to any one of the first to fifth aspects, wherein the sealing means is a portion of the film-like sample placed on the sample placement portion. And a fixing mechanism that presses and fixes the sealing member to the sample mounting portion via the portion.
A seventh aspect of the present invention is the gas permeability measuring apparatus according to the sixth aspect, wherein the sealing means includes a sealing material disposed on an upper surface of the sample mounting portion and capable of elastically contacting the sealing member. It is characterized by comprising.

  According to the gas permeability measuring apparatus of the present invention, it is possible to easily and reliably measure the permeability of oxygen, water vapor, and the like in a state where tension in all in-plane directions is applied to the gas barrier film. As a result, it becomes possible to test the gas barrier performance in a tension state close to the actual state imposed when the barrier film is used.

(A) is the vertical side view which showed typically the container applied to the gas permeability measuring apparatus of this invention, (b) is a top view of the container applied to the gas permeability measuring apparatus of this invention. is there. (A) is the vertical side view which showed typically the state which incorporated the film-form sample and its sealing means in the container in the gas permeability measuring apparatus of this invention, (b) is the top view. (A) is the vertical side view which showed typically the state which incorporated a part of tension | tensile_strength provision means in addition to the film-form sample and its sealing means in the container in the gas permeability measuring apparatus of this invention, (b ) Is a plan view thereof. (A) is a top view of the member for tension | tensile_strength in the gas permeability measuring apparatus of this invention, (b) is a side view of the member for tension | tensile_strength provision. (A) is the vertical side view which showed typically the state which incorporated the tension | tensile_strength provision means in addition to the film-form sample and its sealing means in the container in the gas permeability measuring apparatus of this invention, (b) is the It is a top view. It is operation | movement explanatory drawing of tension | tensile_strength provision in the gas permeability measuring apparatus of this invention. It is operation | movement explanatory drawing of the gas permeability measuring apparatus in this invention. It is explanatory drawing which shows the test result of this invention and the conventional gas permeability measuring apparatus.

(Embodiment 1)
Next, an embodiment of the present invention will be described with reference to FIGS.
In this embodiment, a case where the gas permeability measuring device of the present invention is applied to a cup method for measuring water vapor permeability will be described. In addition, the scale or ratio of each part shown to a figure does not correspond with actual. Further, the gas permeability measuring apparatus according to the present invention is not limited to the structure shown in the drawing.
As shown in FIGS. 1 to 5, the gas permeability measuring device in the present embodiment is a cylindrical container 1 having an upper end opened and a lower end closed, and a film shape set on the opening 5 side end surface of the container 1. Sealing means (consisting of components indicated by reference numerals 7, 9, 10 and 11, etc.) for tightly sealing the inside of the container 1 by bringing the sample 2 into close contact, such as gas or water vapor that permeates the film-like sample 2 Gas supply means for supplying gas (not shown), measurement means for measuring the weight of the gas that has passed through the film-like sample 2 (corresponding to the calcium chloride absorbent 3 introduced into the container 1 in this embodiment) And a tension applying means (consisting of components indicated by reference numerals 8, 12, 15 and 17, etc.) for applying a tension that is pulled outward from the center of the container 1 when viewed in plan. .

At the upper end of the container 1, there is provided a sample placement portion 4 extending in a donut plate shape from the opening 5 toward the outer periphery. This sample mounting part 4 mounts the film-form sample 2 set to the upper end surface of the container 1 so that the opening 5 may be covered.
On the upper surface of the sample mounting portion 4 near the opening 5, a tension applying groove 8 that constitutes a tension applying means extends in a ring shape concentrically with the opening 5 so as to surround the opening 5. The tension applying groove 8 has a semicircular shape with a concave cross-sectional shape cut by a plane orthogonal to the extending direction of the tension applying groove 8.
In addition, a ring-shaped sealing material 6 such as an O-ring that maintains airtightness with the tension applying groove 8 is arranged on the bottom of the tension applying groove 8 over the entire length of the tension applying groove 8. It is installed. Furthermore, a ring that can be elastically contacted, such as an O-ring that maintains airtightness with the film-like sample 2 placed so as to cover the opening 5, in the same manner, near the periphery of the upper surface of the sample placement unit 4. A sealing material 7 is disposed concentrically with the opening 5.

As shown in FIGS. 2 to 5, the sealing means includes a donut plate-shaped sealing member 9 superimposed on a portion 2 a of the film-like sample 2 placed on the sample placement portion 4, and this The sealing member 9 is configured to include the fixing mechanism that presses the sealing member 9 against the sample placement unit 4 via the portion 2 a and fixes the film-like sample 2 to the sample placement unit 4 and the above-described sealing material 7.
The fixing mechanism is configured to sandwich the sealing member 9 and the sample mounting part 4 on both sides of the sample mounting part 4 from above and below in the stacking direction with the sealing material 7 and the part 2a of the film-like sample 2 interposed therebetween. A plurality of letter-shaped fixtures 10 and a fixing screw 11 screwed to a fixing piece 10a abutting against the sealing member 9 of each fixing device 10, and the fixing screw 11 is screwed into the fixing piece 10a. By pressing the sealing member 9 toward the sample mounting portion 4, the film sample 2 is fixed to the sample mounting portion 4 at a plurality of locations (three locations), and the film sample 2 is fixed to the sample mounting portion 4. The inside of the container 1 is hermetically sealed by being in close contact with the upper surface of the container.

As shown in FIGS. 2 to 5, the tension applying means pushes the tension applying groove 8 and the portion 2 a of the film-like sample 2 positioned on the sample mounting portion 4 into the tension applying groove 8. A disk-shaped tension applying member 12 for applying the tension to the film-like sample 4 and a push-in mechanism for pressing the tension applying member 12 into the tension applying groove 8 (parts indicated by reference numerals 15, 16 and 17). ). Further, on the lower surface of the tension applying member 12 facing the upper surface of the sample mounting portion 4, a ridge having a semicircular shape in which the cross-sectional shape cut by a plane orthogonal to the extending direction of the tension applying groove 8 is convex. The portion 13 is formed concentrically with the opening 5 and in a ring shape.
As shown in FIG. 4, the push-in mechanism includes a Y-shaped support member 15 having three support pieces 15 a extending in the radial direction at an angle of 120 ° about the opening 5, and the center of the support member 15. And an adjustment screw 17 that adjusts the pressing force of the tension applying member 12 against the tension applying groove 8. The attachment pieces 15b, which are bent at right angles to the extending ends of the three support pieces 15a, are detachably fixed to the sample mounting portion 4 by fixing screws 16.

Next, an operation when the gas permeability measuring device in the present embodiment is applied to a cup method for measuring water vapor permeability will be described. This sample fixing procedure is performed in an environment of room temperature and low humidity.
First, as shown in FIG. 1A, a calcium chloride absorbent 3 for absorbing water vapor that has passed through the sample film 2 and measuring a weight increase after a predetermined time is put into the container 1. Next, the ring-shaped sealing materials 6 and 7 are set at predetermined positions as shown in FIG.

Next, as shown in FIGS. 2A and 2B, a film sample 2 cut out larger than the outer ring-shaped sealing material 7 on the upper surface of the sample mounting portion 4 so as to cover the opening 5, Place it so that it does not sag, and attach it with tape. In this case, the tape is affixed to the upper surface of the sample mounting portion 4 outside the outer ring-shaped sealing material 7 and the side surface of the sample mounting portion 4 (not shown).
Next, the film-like sample 2 is fixed to the sample mounting portion 4 by using a disk-shaped sealing member 9 having a hole in the center, a fixture 10 and a fixing screw 11. In this case, the outer ring-shaped sealing material 7 is securely fixed so as to be sufficiently deformed. Further, in order to evenly fix the film-like sample 2 on the outer ring-shaped sealing material 7, it is desirable to attach the three fixtures 10 at equal intervals of 120 °. In addition, when it fixes at this space | interval, only one fixing tool appears when it sees from a side surface, but in order to show a fixed state typically in a figure, two fixing tools are displayed for convenience.

Next, as shown in FIGS. 3A and 3B, a tension applying member 12 for applying tension to the film-like sample 2 is placed inside the sealing member 9. In this case, the tension applying member 12 is set on the inner side of the sealing member 9 with the ridge portion 13 facing down. In addition, there is a hole 14 in the center portion of the protruding strip portion 13 of the sealing member 9 so that a high humidity atmosphere is sufficiently supplied to the upper surface of the film-like sample 2 through the tension applying member 12 when measuring the transmittance. I have to.
Next, as shown in FIGS. 5A and 5B, the tension applying support member 15 is fixed to the side surface of the sample mounting portion 4 with a screw 16, and the ridge 13 of the tension applying member 12 is fixed. The film-like sample 2 is pushed and fixed together with the support member 15 and the screw 17 into the tension applying groove 8 of the sample mounting portion 4. In this case, the inner ring-shaped sealing material 6 is securely fixed so as to be sufficiently deformed. As a result, the film-like sample 2 is evenly tensioned.

  The gas permeability measuring apparatus shown in the present embodiment is effective when measuring the gas permeability from the surface of a film-like sample having a total thickness of 10 μm to 200 μm. When the total thickness exceeds 200 μm, since the film-like sample itself has rigidity, even in the actual use situation, the deformation of the film-like sample is slight and the deterioration of the barrier property is small. There is no problem with the measured transmittance.

As materials for the container 1, the sealing member 9, the fixture 10, the tension applying member 12, and the support member 15, for example, common metal materials such as aluminum, brass, and stainless steel can be used. There is no particular limitation as long as water vapor is impermeable, and the rigidity during the test is high. The screws 11, 16, and 17 to be fixed are not limited, but a knurled screw or a wing screw that can be hand-tightened to facilitate fixing is preferable.
In the present invention, the moisture permeable area calculated from the inner diameter of the ring-shaped sealing material 6 may be 25 cm ² or more, similarly to the prescribed value of JIS Z 0208. As long as it is about 20 mm or more.

  As shown in FIG. 6, the film-like sample 2 is pulled by the opening length L of the tension applying groove 8 before pressing the ridge 13 of the tension applying member 12 in the portion of the tension applying groove 8. The film-like sample portion is generated by being pressed into the tension applying groove 8 and extended to L ′. As a result, assuming that the diameter of the region where the transmittance is measured inside the ring-shaped sealing material 6 is D, the tension with the tensile rate in the diameter direction being (L′−L) / D is the center of the film-like sample 2. Will work equally in the outer circumferential direction.

The container 1 fixed with a uniform tension applied in the outer peripheral direction of the film-like sample 2 by the above-described procedure is left in a 40 ° C. and 90% environment defined in JIS Z 0208 for a certain period of time. The calcium absorbent 3 is taken out and determined from the weight change before and after the test by the following formula (1).
Moisture permeability (g / m ² day) = 240 x m / (ts) (1)
Here, s is the moisture permeable area, t is the total time (h) during which the test was performed, and m is the increased mass (mg) before and after the test was performed.

FIG. 7 shows an example in which the gas permeability measuring device of the present invention is applied to an oxygen permeability measuring method (JIS K 7126 B method). Mostly the same as in the case of the cup method described above, but the upper lid member 19 of the transmission cell 18 also serves as the tension applying member 12 in the case of the cup method, and the upper lid member 19 has a small hole 20, Only two of 21 are open. The difference is that oxygen is supplied from one hole 20 and discharged from the other hole 21. Further, nitrogen gas is supplied to the container 1 in which the opening 5 is closed with the film sample 2. The amount of oxygen that has permeated the film sample 2 and reached the container 1 is measured by an oxygen sensor (not shown), and the permeability is calculated.
Since the procedure is the same as in the case of the cup method, description thereof is omitted. In FIG. 7, the same reference numerals as those in FIG. 5 denote the same components as those in FIG.

As described above, in the present embodiment, the film-like sample 2 whose peripheral portion is fixed in a sealed state on the sample placement portion 4 of the container 1 by the sealing means is provided on the upper surface of the sample placement portion 4. The tension applying member 12 having the ridges 13 that can be engaged with the tension applying groove 8 is pushed in by the pushing mechanism, so that the tension applied to the film sample 2 is evenly applied over the entire area of the film sample 2. In addition, the film-like sample can be easily and reliably fixed to the sample placement portion of the container 1.
In addition, by applying the mechanism shown in this embodiment to a cup method container for measuring water vapor permeability and a sample cell for measuring oxygen permeability, tension was applied to the sample, which was close to the actual use state. It becomes possible to test the barrier property against water vapor and oxygen in the state.

Next, examples of the present invention will be described.
Example 1
As the cup method of the present invention, an aluminum container having an opening diameter of 40 mm, an outer peripheral diameter of the sample mounting portion of 110 mm, and a height of 50 mm was prepared. On the upper surface of the sample mounting portion, a ring-shaped tension applying groove having an inner peripheral diameter of 50 mm and an outer peripheral diameter of 70 mm was provided. The cross-sectional shape of the tension applying groove was a semicircular shape having a diameter of 20 mm and a depth of 1.0 mm. An O-ring having a diameter of 60 mm and a cross-sectional diameter of 3 mm was installed at the center of the tension applying groove so that the surface of the tension applying groove was exposed to 0.3 mm. Further, an O-ring having a diameter of 90 mm and a cross-sectional diameter of 3 mm was installed on the upper surface of the sample mounting portion located outside the tension applying groove so as to be exposed by 0.3 mm on the surface of the tension applying groove. Next, a disk with an aluminum hole having an inner peripheral diameter of 80 mm, an outer peripheral diameter of 110 mm, and a thickness of 5 mm was prepared as a sealing member. As the fixture, a U-shaped tool with a screw hole on one surface was made of aluminum. As the tension applying member, a semi-doughnut-shaped convex strip portion having a central peripheral diameter of 60 mm was made of aluminum on a disc-shaped lower surface having a diameter of 76 mm and a thickness of 5 mm. The cross-sectional shape of the ridge portion was a convex semicircle having a diameter of 20 mm, and the height was 2 mm. Further, three fan-shaped window holes having an inner radius of 5 mm, an outer radius of 20 mm, and an opening angle of 60 degrees from the center were formed at intervals of 120 degrees. As the tension applying support member, a Y-shaped member having a plate with a width of 20 mm and a thickness of 7 mm spread radially at an equal interval of 120 degrees in the outer peripheral direction of the container was prepared. The tip portion was bent 90 degrees so that it could be fixed to the side surface of the sample mounting portion with a screw. The distance between the support member and the upper surface of the sample mounting portion was 6 mm. A knurled screw was used to hold the tension applying member. The tensile strain in the radial direction of the sample was about 0.8% based on the shape and depth of the tension applying groove formed and the diameter of the O-ring.

As a sample, a silicon oxide thin film with a thickness of 100 nm formed on a 12 μm polyethylene terephthalate (PET) by resistance heating vapor deposition was cut into a length of 120 mm on one side.
And when the tensile test of the film-form sample was done beforehand using the tension stage and the tensile fracture strain of the silicon oxide film was measured, the fracture strain was about 1%. Therefore, the tension against the tensile fracture strain in this example is about 80%.

Place this sample on the upper surface of the sample mounting part of the container in which the calcium chloride absorbent is placed inside with the membrane surface facing up, and lightly affix the four corners to the side of the sample mounting part with a tape. Then, the sealing member and the fixture were used for fixing, and then tension was applied by the tension applying member and the tension applying support member.
Next, the container was left in a constant temperature and humidity environment of 40 ° C. and 90% RH for 24 hours. Thereafter, the calcium chloride absorbent was taken out and weighed, and the water vapor permeability was determined by the above formula (1) from the weight change before and after standing.
FIG. 7 shows the results of the test conducted three times and the transmittance of the sample measured.

(Example 2)
Compared with the cup method of Example 1 of the present invention, the tension applying groove has a cross-sectional shape of a circle having a diameter of 14 mm, a depth of 2.0 mm, and a semi-doughnut-shaped convex formed on the lower surface of the tension applying member. The same configuration as in Example 1 was manufactured except that the cross-sectional shape of the strip was changed to a semicircular shape with a diameter of 14 mm and a height of 3.0 mm. The tensile strain in the radial direction of the sample was about 1.6% based on the shape and depth of the tension applying groove formed and the diameter of the O-ring. The water vapor permeability was measured by the same procedure as in Example 1.
As in Example 1, the test was performed three times and the water vapor permeability of the sample was measured. The results are shown in FIG.

Next, a comparative example will be described.
(Comparative Example 1)
The water vapor transmission rate was measured under the same conditions as in Example 1 using a general cup not loaded with tension, not the cup method of the present invention.

(Evaluation)
As is apparent from FIG. 8, the water vapor permeability measured by the conventional cup method without applying a tension was the smallest value. On the other hand, in Example 1, the value which is 10-20% higher than the conventional method was shown. This may be due to a change in the transmittance of the PET film itself due to the tension or an influence of a scratch opening latent in the silicon oxide. In Example 2, the transmittance was almost as high as that of PET alone. This is presumably because the tension level exceeded the fracture strain of the silicon oxide film, resulting in cracks in the thin film and loss of barrier properties.
As described above, according to the water vapor permeability measuring apparatus of the present invention, it is confirmed that the permeability when tension is applied to a sample, which is assumed in actual use, can be measured easily and reliably. It was.

Industrial applicability

  The oxygen and water vapor permeability measuring apparatus of the present invention can easily and reliably measure the permeability when tension is applied to a sample, which is assumed in actual use. It can be widely used for barrier film products in various fields.

  DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Film-like sample, 3 ... Calcium chloride absorbent, 4 ... Sample mounting part, 5 ... Opening, 6 ... Ring-shaped sealing material, 7 ... Ring-shaped sealing material, 8 ...... Tensioning groove, 9 ... sealing member, 10 ... fixing tool, 11 ... screw, 12 ... tensioning member, 13 ... projection, 14 ... hole, 15 ... tensioning Supporting member, 16 ... screw, 17 ... screw, 18 ... permeation cell, 19 ... upper lid, 20 ... hole (for oxygen supply), 21 ... hole (for oxygen discharge).

Claims (7)

A container having a sample mounting portion provided with an upper end being opened and extending in a flat plate shape around the periphery of the opening outwardly in an annular shape;
Sealing means for tightly sealing the inside of the container by closely contacting the film-like sample placed on the upper surface of the sample placement unit so as to cover the opening, on the upper surface of the sample placement unit;
Gas supply means for supplying gas or water vapor to the outer surface of the film-like sample opposite to the inside of the container;
In a gas permeability measuring apparatus provided with a measuring means for measuring the amount of the gas or water vapor that is provided in the container and permeates the film sample and enters the container,
The film-like sample is provided with a tension applying means for applying a tension that is pulled outward from the center of the container when viewed in plan.
A gas permeability measuring device.   The tension applying means includes a tension applying groove formed in an annular shape so as to surround the opening on an upper surface of the sample mounting portion, and a position of the film-like sample positioned on the tension applying groove. A tension applying member that is pushed into the applying groove and applies the tension to the film sample, and a pressing mechanism that presses the tension applying member into the tension applying groove. Item 2. The gas permeability measuring apparatus according to Item 1. The cross-sectional shape cut by a plane orthogonal to the extending direction of the tension applying groove exhibits a concave semicircle,
The tension applying member has an annular shape,
The portion where the tension applying member engages with the tension applying groove is formed as a convex strip portion having a convex semi-circular cross section cut by a plane orthogonal to the extending direction. The gas permeability measuring apparatus according to claim 2.   The push-in mechanism includes a support member that is detachably provided on the sample mounting portion, and an adjustment member that is provided on the support member and adjusts the pressing force of the tension applying member against the tension applying groove. The gas permeability measuring device according to claim 2, wherein   The gas permeability measuring device according to claim 2 or 3, wherein an elastic contactable seal member that maintains airtightness with the tension applying member is disposed in the tension applying groove.   The sealing means includes a sealing member that is overlaid on a location of the film-like sample placed on the sample placement portion, and the sealing member that is placed on the sample placement portion via the location. 6. The gas permeability measuring device according to claim 1, further comprising a fixing mechanism that presses and fixes the gas permeation measuring device.   The gas permeability measuring apparatus according to claim 6, wherein the sealing means includes a sealing material that is disposed on an upper surface of the sample mounting portion and can be elastically contacted with the sealing member.

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