JP7072222B2 - Membrane material and membrane structure - Google Patents

Description

The present invention relates to membrane materials and membrane structures.

As a film material for construction, for example, a film material in which a woven fabric such as glass cloth is coated with a fluororesin is known. This film material has excellent weather resistance, stain resistance, and light weight, and is therefore used in buildings having a large space.

However, the heat insulating property and the soundproofing property of such a film material are not sufficient.

Japanese Unexamined Patent Publication No. 2009-015227 Japanese Unexamined Patent Publication No. 2004-206105

An object of the present invention is to provide a film material having excellent weather resistance, as well as excellent heat insulating properties and soundproofing properties.

According to the first aspect of the present invention, a film material is provided. This film material comprises a polytetrafluoroethylene moiety and a woven fabric, wherein the polytetrafluoroethylene moiety is a first portion having a bulk density of 2 g / cm ³ or more and a bulk density of less than 2 g / cm ³ . A laminate including a second portion, at least a portion of the woven fabric covered with the first portion, including the woven fabric and a fabric layer containing the first portion, and a porous layer containing the second portion. The ratio of the thickness T _por of the porous layer to the thickness T _all of the film material is in the range of 40% to 84% .

According to the second aspect of the present invention, a film structure provided with the film material according to the first aspect is provided.

According to the present invention, it is possible to provide a film material having excellent weather resistance, as well as excellent heat insulating properties and soundproofing properties.

FIG. 3 is a sectional view schematically showing an example of a film material of an embodiment. FIG. 5 is a cross-sectional view schematically showing an example of a method for manufacturing a film material according to an embodiment. The graph which shows the heat insulation effect of the film material which concerns on Example and the comparative example. The graph which shows the heat insulating effect of the film material which concerns on Example and the comparative example. The graph which shows the heat insulating effect of the film material which concerns on Example and the comparative example.

As described above, the film material obtained by coating the glass cloth with fluororesin has general performance required for the film material using fluororesin, that is, weather resistance, stain resistance, high mechanical strength and light weight. Is satisfied. However, the single-layer structure of this film material does not have sufficient heat insulating properties and soundproofing properties.

It is considered that the cause of this is that the fluororesin coated on the glass cloth is not porous.

The film material according to the embodiment includes a polytetrafluoroethylene moiety and a woven fabric, and the polytetrafluoroethylene moiety has a first portion having a bulk density of 2 g / cm ³ or more and a bulk density of 2 g / cm. At least a portion of the woven fabric is covered with the first portion, including a second portion of less than ^three .

Since at least a part of the woven fabric is covered with the first portion having a bulk density of 2 g / cm ³ or more, the film material according to the embodiment is excellent in mechanical strength, weather resistance and the like. Here, the first portion is a part of the polytetrafluoroethylene (PTFE) portion. The PTFE portion further comprises a second portion. This second portion has a bulk density of less than 2 g / cm ³ and has, for example, a porous structure.

If the bulk density of the second portion is less than 2 g / cm ³ , the volume of the voids per unit volume is large, so that the second portion is difficult to transmit heat and sound. That is, of the polytetrafluoroethylene moiety, the heat insulating property and soundproofing property of the second portion are particularly excellent. When the bulk density of the second portion is 2 g / cm ³ or more, the volume of the voids per unit volume is small, so that the conductivity of heat and sound is high, which is not preferable.

The film material according to the embodiment includes a woven fabric and a PTFE portion including the first portion and the second portion described above, and at least a part of the woven fabric is covered with the first portion. Therefore, it is excellent in weather resistance, as well as in heat insulating property and soundproofing property.

Hereinafter, the film material according to the embodiment will be described in detail with reference to the drawings. It should be noted that the same reference numerals are given to the common configurations throughout the embodiments, and duplicate description will be omitted. In addition, the drawings are schematic views for explaining the embodiments and promoting their understanding, and the shapes, dimensions, ratios, etc. of the drawings differ from those of the actual device. With reference to this, the design can be changed as appropriate.

FIG. 1 is a cross-sectional view schematically showing an example of a film material of an embodiment.

The film material 1 is a sheet extending in the in-plane direction orthogonal to the thickness direction. FIG. 1 schematically shows a part of the case where the film material 1 is cut along the thickness direction.

The membrane material 1 includes a polytetrafluoroethylene (PTFE) portion 100 and a woven fabric 111.

The woven fabric 111 is constructed by weaving, for example, glass fiber or aramid fiber. The woven structure of the woven fabric 111 is not particularly limited, but is, for example, a plain weave. In order to increase the mechanical strength of the film material 1, the woven fabric 111 is preferably made of glass fiber.

The PTFE portion 100 includes a first portion 110 having a bulk density of 2 g / cm ³ or more and a second portion 120 having a bulk density of less than 2 g / cm ³ . The PTFE portion 100 may consist of a first portion 110 and a second portion 120. Each of the first portion 110 and the second portion 120 is substantially composed of PTFE. The PTFE portion 100 may include a third portion containing a fluororesin other than PTFE.

The "bulk density" is calculated by the following formula from the thickness of the measurement target (for example, the first portion) and the weight per unit area of the measurement target. A detailed measurement method such as a method of preparing a measurement target will be described later.
Bulk density (g / cm ³ ) = weight per unit area (g / m ² ) / thickness (cm).

The first portion 110 is provided so as to cover both sides of the woven fabric 111, for example. The first portion 110 may be provided so as to cover one side of the woven fabric 111, or may be provided so as to cover only a part of the woven fabric 111. Since the first portion 110 is PTFE having a bulk density of 2 g / cm ³ or more, the volume of the voids existing in the portion is small. That is, the specific surface area of the first portion 110 is small. Therefore, the first portion 110 is excellent in weather resistance and stain resistance. The bulk density of the first portion is preferably in the range of 2 g / cm ³ to 2.2 g / cm ³ , and more preferably in the range of 2.13 g / cm ³ to 2.2 g / cm ³ .

The second portion 120 is formed in succession with the first portion 110, for example, by fusing the PTFE of the second portion 120 and the PTFE of the first portion 110. The second portion may be provided on the first portion. The second portion 120 may include a portion covering the woven fabric 111. The second portion 120 has a plurality of voids (pores) 121. The plurality of voids 121 may or may not communicate with each other. Both voids that communicate with each other and voids that do not communicate with each other may exist.

The bulk density of the second portion 120 is preferably in the range of 0.11 g / cm ³ to 1.32 g / cm ³ , more preferably in the range of 0.11 g / cm ³ to 0.86 g / cm ³ . Yes, more preferably in the range of 0.11 g / cm ³ to 0.66 g / cm ³ . When the bulk density of the second portion 120 is within this range, a film material having a lighter weight and higher heat insulating performance can be obtained.

The porosity of the first portion 110 is, for example, in the range of 0% to 5%. The porosity of the second portion 120 is, for example, in the range of 40% to 95%. The porosity of the second portion 120 is preferably in the range of 70% to 95%. Porosity can be measured according to JIS R 1634: 1998.

The density of the first portion 110 is, for example, in the range of 2 g / cm ³ to 2.2 g / cm ³ . The density of the second portion 120 is, for example, in the range of 2 g / cm ³ to 2.2 g / cm ³ . Here, "density" means the density of the material itself. That is, the density of PTFE is shown here. "Density" can be measured according to JIS K 7112: 1999.

At least a part of the woven fabric 111 is covered with the first portion 110. As shown in FIG. 1, for example, the entire woven fabric 111 is covered with the first portion 110.

FIG. 1 depicts, as an example, a case where the film material 1 is a laminated body 10 in which a fabric layer 11 and a porous layer 12 are laminated.

The fabric layer 11 is composed of, for example, a woven fabric 111 and a first portion 110. The fabric layer 11 may further include a second portion 120. In this case, since the second portion 120 functions as the porous portion, the porous layer 12 can be omitted. However, from the viewpoint of heat insulating property and soundproofing property, it is preferable that the second portion 120 is present over the entire area of the film material 1 in the in-plane direction. Therefore, it is preferable not to omit the porous layer 12.

The ratio of the weight of the first portion to the weight of the fabric layer 11 is preferably in the range of 18% by weight to 30% by weight. Within this range, the film material is excellent in both mechanical strength and weather resistance, and has sufficient flexibility. Therefore, when the membrane material is used for a building such as a membrane structure, it becomes easy to flexibly deform it.

In the film material 1 shown in FIG. 1, the porous layer 12 is laminated on the fabric layer 11. The porous layer 12 is composed of, for example, a second portion 120, and is laminated with the fabric layer 11 and fused to each other. The porous layer 12 is, for example, a porous sheet. This porous sheet contains a second portion 120 having a bulk density of less than 2 g / cm ³ . The porous layer 12 may be a laminated body in which two or more porous sheets are laminated. In this case, the two or more porous sheets may be porous sheets having the same bulk density as each other, or may be porous sheets having different bulk densities. By laminating a plurality of porous sheets as the porous layer 12, the heat insulating property and soundproofing property of the membrane material can be adjusted.

The film material 1 may be a laminated body provided with another layer. The other layer is, for example, a layer different from the fabric layer 11 and different from the porous layer 12. The other layers may be present on the fabric layer 11, may be present on the porous layer 12, and may be interposed between the fabric layer 11 and the porous layer 12.

Examples of the other layer include a layer made of a fluororesin other than PTFE, an adhesive layer made of a silane coupling agent, a metal layer, a printing layer, a light diffusion layer, an antifouling layer, and the like.

It is more preferable that the film material 1 includes a laminated body having a three-layer structure in which the fabric layer 11, the porous layer 12, and the fabric layer 11 are laminated. In this three-layer structure laminate, another layer may be interposed between the fabric layer 11 and the porous layer 12, if necessary. Another layer may be laminated on the fabric layer 11 (the surface not facing the porous layer 12). With such a three-layer structure, heat and sound are less likely to be conducted from one main surface of the film material 1 to the other main surface.

Examples of the fluororesin other than PTFE include perfluoroalkoxy alkane resin (PFA) and fluorinated ethylene / fluorinated propylene copolymer resin (FEP). The fluororesin other than PTFE may be one kind or a mixture of two or more kinds.

Since the fabric layer 11 has excellent weather resistance, it is preferable that the fabric layer 11 does not have another layer on the fabric layer 11. Alternatively, it is also preferable to have an antifouling layer on the fabric layer 11.

The weight per unit area of the film material is in the range of 500 g / m ² to 8500 g / m ² , preferably in the range of 1000 g / m ² to 4000 g / m ² . If the weight per unit area of the membrane material is too large, the membrane material is heavy, and when this membrane material is used for construction, the number of frames such as columns supporting the membrane material may increase. As a result, it tends to be difficult to flexibly change the design of the building, which is not preferable. If the weight per unit area of the film material is small, for example, the film material is thin, so that the strength may be insufficient, and the heat insulating property and the soundproofing property may be lowered.

The total thickness of the film material is not particularly limited, but is in the range of, for example, 0.4 mm to 6.15 mm.

The thickness of the fabric layer is, for example, in the range of 0.3 mm to 1.15 mm, preferably in the range of 1 mm to 3 mm. If the fabric layer is too thin, it may be less strong when the membrane material is used for construction.

The thickness of the porous layer is, for example, in the range of 0.001 mm to 5 mm, preferably in the range of 1 mm to 3 mm. If the porous layer is too thick, the weight per unit area of the membrane material tends to be too large. It may also be difficult to fuse with the fabric layer.

By appropriately adjusting the thickness of the fabric layer and / or the thickness of the porous layer, the heat insulating property and the soundproofing property of the film material can be adjusted. In particular, the thickness of the porous layer has a great influence on the heat insulating property and the soundproofing property of the membrane material.

The ratio of the thickness T _por of the porous layer to the total thickness T _all of the membrane material is, for example, 1% or more. This ratio is preferably in the range of 40% to 60%. When this ratio is in the range of 40% to 60%, the weight per unit area of the film material does not become too large, and sufficient heat insulating properties and soundproofing properties can be achieved. In addition, since the hardness and softness of the film material does not become too high, it is easy to bend it when it is used in a building.

<Measuring method of film thickness>
The film material is cut along the thickness direction, and the cut surface is observed with a scanning electron microscope (SEM). The magnification is, for example, 100 times.

By this observation, it can be confirmed that the film material contains the first portion and the second portion. Therefore, the total thickness T _all of the membrane material, the thickness T _fab of the first portion or the fabric layer, and the thickness T _por of the second portion or the porous layer can be measured.

<Measuring method of weight per unit area of membrane material>
The membrane material is cut into 100 mm × 100 mm test pieces, weighed to 1 mg units, the weight is converted into units of g / m ² , and the weight per unit area is measured.

<Measurement of bulk density>
First, the first portion and the second portion contained in the film material are peeled off at the adhesive interface to obtain a single second portion. Then, the first part is peeled off from the woven fabric to obtain a single first part. The obtained first portion and second portion are to be measured, respectively.

The "bulk density" in the present specification is measured as follows.
The thickness of the measurement target separated by the above method is measured with a constant pressure thickness measuring device capable of measuring with an accuracy of 1/100 mm. Further, this measurement target is cut into a test piece of 100 mm × 100 mm, weighed up to 1 mg unit, the weight is converted into a unit of g / m ² , and the weight per unit area is measured.

From the thickness of the measurement target measured in this way and the weight per unit area, the bulk density is measured by the following formula.
Bulk density (g / cm ³ ) = weight per unit area (g / m ² ) / thickness (cm).

Hereinafter, an example of a method for manufacturing a film material according to an embodiment will be described.

<Manufacturing of fabric>
An example of a method for manufacturing a fabric as a fabric layer will be described with reference to FIG. FIG. 2 is a cross-sectional view schematically showing a coating device for coating a PTFE resin on a glass fiber woven fabric (glass cloth).

Reference numeral 20 in the figure indicates a delivery roll that sends out the glass cloth 2 as a base material. An impregnation tank 4 filled with an aqueous dispersion 3 of PTFE resin particles is arranged on the downstream side of the delivery roll 20. The glass cloth 2 wound around the delivery roll 20 is sent to the roll 5b side arranged in the aqueous dispersion liquid 3 of the impregnation tank 4 via the roll 5a, and the aqueous dispersion liquid 3 is applied to the glass cloth 2. A pair of doctor rolls 6 are arranged on the upper side of the impregnation tank 4, and the excess aqueous dispersion 3 is scraped off. On the upper side of the doctor roll 6, a heating furnace 7 is arranged so as to have different heat treatment temperatures. The heating furnace 7 is divided into three blocks, a drying section 7a, a heat treatment section 7b, and a firing section 7c, in order from the bottom, and has a temperature distribution in which the temperature is sequentially increased from the drying section 7a to the firing section 7c. It is controlled so as to. Rolls 5c, 5d and 5e and a take-up roll 9 are arranged downstream of the heating furnace 7.

A method for manufacturing a fabric using a coating device having the above configuration will be described.

First, the glass cloth 2 wound around the delivery roll 20 is sent to the roll 5b side arranged in the PTFE resin particle aqueous dispersion 3 of the impregnation tank 4, and the aqueous dispersion 3 is applied to the glass cloth 2. Next, the excess aqueous dispersion 3 applied to the surface of the glass cloth 2 is scraped off by the pair of doctor rolls 6. Subsequently, the glass cloth 2 coated with the PTFE resin is sent to the drying portion 7a of the heating furnace 7, and the coated PTFE resin is dried at a temperature of 100 ° C. or lower to evaporate the water content in the aqueous dispersion 3. Next, the glass cloth 2 is sent to the heat treatment unit 7b and slowly heat-treated at, for example, 305 ° C. to remove the surfactant, the additive, the binder and the like in the aqueous dispersion 3.

In the subsequent firing unit 7c, firing may or may not be performed. When not fired, the resulting fabric 8 has excellent mechanical strength and abrasion resistance as well as excellent flexibility. When firing in the firing section 7c, the firing temperature is set to a temperature equal to or higher than the melting point of the PTFE resin. The fabric 8 that has passed through the fired portion 7c is taken up by the take-up roll 9 via the rolls 5c, 5d, and 5e. In this way, it is possible to prepare a fabric layer including the first portion having a bulk density of 2 g / cm ³ or more and the woven fabric, and at least a part of the woven fabric is covered with the first portion.

Here, "drying" is preferably a step of evaporating the water content in the coated PTFE resin aqueous dispersion at a temperature of 100 ° C. or lower. Further, the "heat treatment" is a step of treating and removing components other than the PTFE resin such as surfactants, additives and binders in the coated PTFE resin particle aqueous dispersion in a predetermined temperature range. Is preferable. The temperature range of the heat treatment is preferably 305 ° C or higher and lower than 340 ° C.

<Manufacturing of porous film>
An example of a method for producing a porous film as a porous layer will be described.

Prepare PTFE fine powder, and mix 20 to 30 parts by mass of hydrocarbon oil with 100 parts by mass of this powder. After stirring the mixture so as to be uniform, the paste is extruded and preformed into a rod shape. The obtained preformed product is rolled using, for example, a metal rolling roll. In this way, an unfired tape which is a precursor of the porous film is obtained. The shape of the unfired tape is not particularly limited, but is, for example, a rectangle or a substantially square shape.

This unbaked tape is stretched at a temperature below the melting point in the previously rolled direction, that is, in the mechanical direction (MD direction) at a magnification of 2 to 6 times. The temperature at this time is, for example, 280 ° C. Stretching at a temperature below this melting point draws fibril between the nodes of the PTFE. As a result, a cavity is formed in this PTFE tape and can be made porous.

Next, firing is performed at a temperature equal to or higher than the melting point. The temperature above the melting point is, for example, 360 ° C. The unfired tape that has been made porous by the above-mentioned stretching has poor dimensional stability and may gradually shrink even at room temperature. This shrinkage can be prevented by firing the unbaked tape at a temperature equal to or higher than the melting point and heat-setting it.

Subsequently, the fired PTFE film is stretched again at a temperature below the melting point. The temperature of this re-stretching is, for example, 250 ° C. This stretching is performed, for example, at a magnification of 2 to 6 times in the mechanical direction. This re-stretching may be omitted. By the above method, a porous layer containing a second portion having a bulk density of less than 2 g / cm ³ can be produced.

Here, the method of producing the porous film by uniaxial stretching has been described, but the porous film may be produced by biaxial stretching.

<Manufacturing of membrane material>
The film material according to the embodiment is obtained, for example, by thermally laminating the fabric and the porous film produced above. Alternatively, the film material may be manufactured by adhering a fabric and a porous film using an adhesive layer. Examples of the surface treatment for adhering the fabric and the porous film include metallic sodium treatment and plasma treatment. Further, the film material can also be produced by making the PTFE resin layer provided on the surface of the fabric porous.

The film material can also be produced by spraying a PTFE dispersion containing a foaming agent onto the fabric. By spraying the PTFE dispersion, a second portion having a bulk density of less than 2 g / cm ³ can be formed.

The thermal laminating can be carried out, for example, by the following method.

First, the fabric and the porous film produced above are cut into desired dimensions. These are then glued together using a roll laminator. This bonding is performed under the conditions that the roll temperature is in the range of 360 ° C to 420 ° C, the linear pressure is in the range of 20 N / cm to 60 N / cm, and the roll speed is in the range of 1 m / min to 4 m / min. .. By laminating under such conditions, the porous film can be laminated without being crushed, so that a film material having a bulk density of the second portion of less than 2 g / cm ³ can be obtained.

As described above, the roll temperature is, for example, 360 ° C to 420 ° C, preferably 380 ° C to 400 ° C. If the roll temperature is lower than 360 ° C, fusion failure may occur, and if it exceeds 420 ° C, PTFE is decomposed, which is not preferable.

As described above, the linear pressure is, for example, 20 N / cm to 60 N / cm, preferably 30 N / cm to 40 N / cm. If the linear pressure is lower than 20 N / cm, fusion failure may occur, and if it exceeds 60 N / cm, the pores of the porous film are greatly crushed and the bulk density of the second part becomes 2 g / cm ³ or more. , Insulation and soundproofing may be reduced.

As described above, the roll speed is, for example, 0.5 m / min to 4 m / min. If the roll speed is lower than 0.5 m / min, the production efficiency is poor, and if it is higher than 4 m / min, fusion failure may occur.

In the fabric provided with the PTFE resin layer, for example, the following method can be adopted to make the PTFE resin layer porous. First, a fabric is prepared in which a PTFE resin layer contains a material that decomposes at a temperature lower than the decomposition temperature of PTFE. The fabric is then heated to a temperature above and below the breakdown point of the material and below the breakdown point of PTFE. By this heating, the above-mentioned material is removed from the PTFE resin layer and voids are created. The portion including the void thus generated corresponds to the second portion according to the embodiment. Examples of the material include acrylic resin and styrene resin.

The fabric produced by this method does not have a porous layer as a layer, but contains a PTFE portion having a first portion and a second portion, and the first portion covers at least a part of the woven fabric. .. Therefore, the fabric produced by this method is nothing but the film material of the embodiment.

The membrane material according to the embodiment can be used, for example, as a building membrane material constituting at least a part of the membrane structure. When the membrane structure includes the membrane material according to the embodiment, excellent weather resistance, excellent heat insulating property and soundproofing property can be achieved.

Examples of membrane structures include large greenhouses, atriums, athletic facilities, medium and large tents and agricultural greenhouses. Membrane materials are used for roofing materials such as large-scale greenhouses and atriums, outer walls of sports facilities, outer walls of medium- and large-sized tents, and covering materials for agricultural greenhouses.

The film structure according to the embodiment is provided with an outer wall made of the film material according to the embodiment, and it is preferable that the first portion having a bulk density of 2 g / cm ³ or more is exposed on the surface of the outer wall. For example, it is preferable that the fabric layer is located on the surface (outdoor side) of the outer wall. Since the first portion has excellent weather resistance, since the first portion is exposed on the surface of the outer wall, the life of the membrane structure can be extended and the maintenance effort can be reduced. The second portion contained in the film material may be exposed on the surface of the outer wall, but it is preferable that the second portion is not exposed on the surface of the outer wall. For example, the porous layer including the second portion is located on the inner surface side (indoor side) of the outer wall. The outer wall may contain other building materials.

[Example]
Examples will be described below, but the embodiments are not limited to the examples described below.

(Example 1)
<Making fabric>
As a fabric used for the fabric layer, FGT-600 manufactured by Chukoh Chemical Industries, Ltd. with a thickness of 0.576 mm was prepared. This fabric contained glass cloth (B yarn) as a woven fabric and contained a first portion of PTFE having a bulk density of 2 g / cm ³ or more. In addition, both sides of the woven fabric were covered with the first portion. This fabric was cut to a size of 100 mm × 100 mm to prepare a fabric layer.

<Making a porous film>
As a porous film used for the porous layer, a PTFE porous film having a thickness of 1 mm and a bulk density of 0.53 g / cm ³ manufactured by Chukoh Chemical Industries, Ltd. was prepared. This porous film was cut to a size of 100 mm × 100 mm to prepare a porous layer.

<Preparation of membrane material>
The prepared fabrics and porous films were laminated, heat-laminated, and these were bonded together. The thermal laminating was performed using a roll laminator under the conditions of a roll temperature of 400 ° C., a linear pressure of 30 N / cm, and a roll speed of 0.5 m / min. In this way, the film material according to Example 1 was produced. The produced film material was a laminate similar to the film material shown in FIG.

When the bulk density of the first portion of the produced film material was measured according to the method described in the embodiment, it was 2.13 g / cm ³ . The bulk density of the second part was measured and found to be 0.53 g / cm ³ .

The weight per unit area of this film material was measured according to the method described in the embodiment and found to be 1530 g / m ² .

<Insulation performance evaluation>
The heat insulating performance of the prepared film material was evaluated by the following method.

Membrane material was placed on the heater so that the fabric layer was in contact with the heater. A thermometer using a thermocouple was prepared, and the thermocouple was attached to the other surface of the membrane material (the surface of the porous layer) using a fluororesin adhesive tape. The set temperature of the heater was set to 40 ° C., and the temperature of the surface of the porous layer was measured after being left until the temperature of the surface of the porous layer did not change.

This measurement was performed by changing the set temperature of the heater to 60 ° C, 80 ° C, 100 ° C and 120 ° C, respectively. Here, each example when the set temperature of the heater is 40 ° C., 60 ° C., 80 ° C., 100 ° C. and 120 ° C. is set to Examples 1-1 to 1-5, respectively.
The above results are summarized in Table 1A.

(Example 2)
A film material was prepared and evaluated by the same method as described in Example 1 except that the following was used as the porous film. The results are summarized in Table 2A.

A PTFE porous film having a thickness of 1 mm and a bulk density of 0.53 g / cm ³ manufactured by Chukoh Chemical Industries, Ltd. was prepared, and three sheets of the PTFE porous film were laminated and heat-laminated. The thermal laminating was performed using a roll laminator under the conditions of a roll temperature of 400 ° C., a linear pressure of 30 N / cm, and a roll speed of 0.5 m / min. In this way, a porous film having a thickness of 3 mm was obtained.

(Example 3)
As the porous film, a film by the same method as described in Example 1 except that a PTFE porous film manufactured by Chukoh Chemical Industries, Ltd. having a thickness of 0.2 mm and a bulk density of 0.53 g / cm ³ was used. Materials were prepared and evaluated. The results are summarized in Table 3A.

(Comparative Example 1)
Examples except that a non-porous film manufactured by Chukoh Chemical Industries, Ltd. (MSF-100 manufactured by Chukoh Chemical Industries, Ltd.) having a thickness of 1 mm and a bulk density of 2.13 g / cm ³ was used instead of the porous film. A film material was prepared and evaluated by the same method as described in 1. The results are summarized in Table 1B.

(Comparative Example 2)
A film material was prepared and evaluated by the same method as described in Comparative Example 1 except that the following non-porous film was used. The results are summarized in Table 2B.

A non-porous film manufactured by Chukoh Chemical Industries, Ltd. with a thickness of 1 mm and a bulk density of 2.13 g / cm ³ was prepared, and three sheets of the non-porous film were laminated and heat-laminated. The thermal laminating was performed using a roll laminator under the conditions of a roll temperature of 400 ° C., a linear pressure of 30 N / cm, and a roll speed of 0.5 m / min. In this way, a non-porous film having a thickness of 3 mm was obtained.

(Comparative Example 3)
The same method as described in Example 1 except that a non-porous film manufactured by Chukoh Chemical Industries, Ltd. having a thickness of 0.2 mm and a bulk density of 2.13 g / cm ³ was used instead of the porous film. A film material was prepared and evaluated. The results are summarized in Table 3B.

(Comparative Example 4)
A film material was prepared and evaluated by the same method as described in Example 1 except that the porous film was not laminated. That is, since the membrane material according to Comparative Example 4 consisted only of the fabric layer, it contained a woven fabric and a first portion, but did not include a second portion having a bulk density of less than 2 g / cm ³ . Table 4 summarizes the evaluation results of the heat insulating performance according to Comparative Example 4.

In Tables 1 to 4 above, the column "T _por / T _all " shows the value obtained by multiplying the value of the thickness T _por of the porous layer with respect to the total thickness T _all of the membrane material by 100 as a percentage. The column "Weight per unit area" shows the weight per unit area of the membrane material. "Set temperature" indicates the set temperature of the heater. “Surface temperature” indicates the surface temperature of the porous layer in Examples 1 to 3, the surface temperature of the non-porous layer in Comparative Examples 1 to 3, and the fabric layer in Comparative Example 4. Shows the surface temperature of. The "front surface" referred to here refers to a surface of the two surfaces (for example, the front surface and the back surface) of the film material, which is not the surface on the side in contact with the heater.

FIG. 3 shows the results of Examples 1-1 to 1-5, Comparative Examples 1-1 to 1-5, and Comparative Examples 4-1 to 4-5 by plotting the surface temperature with respect to the set temperature in a graph. ing. The horizontal axis shows the set temperature of the heater in each example, and the vertical axis shows the surface temperature of the film material at each of the set temperatures.

FIG. 4 shows the results of Examples 2-1 to 2-5, Comparative Examples 2-1 to 2-5, and Comparative Examples 4-1 to 4-5 by plotting the surface temperature with respect to the set temperature in a graph. ing. The horizontal axis shows the set temperature of the heater in each example, and the vertical axis shows the surface temperature of the film material at each of the set temperatures.

FIG. 5 shows the results of Examples 3-1 to 3-5, Comparative Examples 3-1 to 3-5, and Comparative Examples 4-1 to 4-5 by plotting the surface temperature with respect to the set temperature in a graph. ing. The horizontal axis shows the set temperature of the heater in each example, and the vertical axis shows the surface temperature of the film material at each of the set temperatures.

As is clear from the graph of FIG. 3, the film material according to Example 1 has excellent heat insulating properties as compared with the film material according to Comparative Example 1 and the film material according to Comparative Example 4 at any set temperature. ..

As is clear from the graph of FIG. 4, the film material according to Example 2 has excellent heat insulating properties as compared with the film material according to Comparative Example 2 and the film material according to Comparative Example 4 at any set temperature. ..

As is clear from the graph of FIG. 5, the film material according to Example 3 has excellent heat insulating properties as compared with the film material according to Comparative Example 3 and the film material according to Comparative Example 4 at any set temperature. ..

The present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate, in which case the combined effect can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent requirements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect is obtained, the configuration in which the constituent elements are deleted can be extracted as an invention.
The inventions described in the original claims of the present application are described below.
[1]
Includes polytetrafluoroethylene moiety and woven fabric,
The polytetrafluoroethylene moiety comprises a first moiety having a bulk density of 2 g / cm ³ or more and a second moiety having a bulk density of less than 2 g / cm ³ .
A film material in which at least a part of the woven fabric is covered with the first part.
[2]
A fabric layer containing the woven fabric and the first portion,
The film material according to [1], which is a laminate including the porous layer containing the second portion.
[3]
The film material according to [2], wherein the porous layer is laminated on the fabric layer.
[4]
The film material according to [2] or [3], wherein the ratio of the thickness T _por of the porous layer to the thickness T _all of the laminate is 1% or more.
[5]
The film material according to any one of [1] to [4], wherein the weight per unit area is in the range of 500 g / m ² to 8500 g / m ² .
[6]
A film structure comprising the film material according to any one of [1] to [5].
[7]
An outer wall made of the film material is provided, and the outer wall is provided.
The membrane structure according to [6], wherein the first portion is exposed on the surface of the outer wall.

1 ... Membrane material,
2 ... Glass cloth,
3 ... Aqueous dispersion,
4 ... Impregnation tank,
5 ... Roll,
6 ... Doctor Roll,
7 ... Heating furnace,
8 ... Fabric,
9 ... Take-up roll,
10 ... Laminated body,
11 ... Fabric layer,
12 ... Porous layer,
20 ... Sending roll,
100 ... Polytetrafluoroethylene moiety,
110 ... Part 1,
111 ... Woven fabric,
120 ... Second part,
121 ... Void.

Claims (6)

Includes polytetrafluoroethylene moiety and woven fabric,
The polytetrafluoroethylene moiety comprises a first moiety having a bulk density of 2 g / cm ³ or more and a second moiety having a bulk density of less than 2 g / cm ³ .
At least a part of the woven fabric is covered with the first part.
A fabric layer containing the woven fabric and the first portion,
A film material which is a laminated body including a porous layer containing the second portion.
A film material in which the ratio of the thickness T _por of the porous layer to the thickness T _all of the laminate is in the range of 40% to 84% . The film material according to claim 1 , wherein the porous layer is laminated on the fabric layer. The film material according to claim 1 or 2 , wherein the ratio of the thickness T _por of the porous layer to the thickness T _all of the laminate is in the range of 63% to 84% . The film material according to any one of claims 1 to 3 , wherein the weight per unit area is in the range of 500 g / m ² to 8500 g / m ² . A membrane structure comprising the membrane material according to any one of claims 1 to 4 . An outer wall made of the film material is provided, and the outer wall is provided.
The membrane structure according to claim 5 , wherein the first portion is exposed on the surface of the outer wall.

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