JP2003026222A - Ventilation packing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ventilation packing which is effective in preventing the breakage of a container containing a gas generation fluid body or solid body, and whose non-permeable characteristic and ventilation characteristic are not spoiled for a long time and through which the content does not leak out even when the container is fallen down and the packing is made wet by the fluid content. SOLUTION: In forming this packing 1, a polyolefin micro-porous film 2 whose limiting viscosity number (η) is 3 dl/g or more, a polyolefin sheet material 5 having an air channel 4 communicating from a face side to an end face side, and a polyolefin packing base material 3 are laminated and thermo compression bonded in the order. When the film 2 is provided on the cap 7 of a container 6 storing a gas generating content facing the content, the gas generated from the content permeates the film 2, passes through the sheet material 5 from the face where the film 2 contacts to the end face along the inside face of the base material 3, and escapes to the outside through the side face (screw part) of the cap 7. It is so formed that even when the container 6 is fallen down, the content does not leak.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to breathable packing suitable for container caps. Particularly, the present invention relates to a breathable packing suitable for a cap of a container filled with gas-prone contents.

[0002]

2. Description of the Related Art Conventionally, this type of breathable packing has been
A film-like material having liquid impermeability and air permeability is used. As such a film-like material, a porous film made of tetrafluoroethylene or a woven or non-woven fabric-like polyolefin sheet material having a molecular weight not so high as left is used.

[0003]

However, the air-permeable packing using the above-mentioned tetrafluoroethylene or a polyolefin sheet having a not so high molecular weight, when used in a liquid container for generating gas, allows the gas to escape during normal times. However, there was a problem that the contents (liquid) leaked out after a lapse of time after the container was tumbled or laid down and the whole surface of the breathable packing was covered (wet) by the liquid. Further, since the conventional packing has a ventilation path that escapes from surface to surface, in order to actually apply it to a cap of a container filled with gas-prone contents, a suitable size for allowing gas to escape to the cap itself. This is because it was necessary to make a hole in the hole.

The present invention is intended to solve the above problems, and an object thereof is to prevent the rupture of a container containing a liquid or a solid that generates a gas, and to prevent the container from falling. It is an object of the present invention to provide a breathable packing in which liquid impermeability and breathability are not impaired for a long period of time even when it is wet with a liquid content, and the content does not leak out.

[0005]

In order to achieve the above object, the breathable packing according to the present invention has an intrinsic viscosity [η].
A microporous polyolefin film having a density of 3 dl / g or more,
A polyolefin-based sheet material having a gas flow path from the surface side to the end surface side, and a polyolefin packing base material are laminated in this order and thermocompression-bonded, and the cap of the container containing the content for generating gas is characterized. In addition, when used so that the microporous film faces the content side, the gas generated from the content permeates the microporous film and escapes the sheet material from that surface to the end surface along the inner surface of the packing base material. The cap is designed to escape to the outside through the side surface (screwed part) of the cap and prevent the contents from leaking when the container falls down.

Further, the microporous film as claimed in claim 2,
Porosity 25-90%, Air permeability 50-2000 seconds / 100
cc and the thickness is in the range of 10 to 200 μm, and the microporous film according to claim 3 has an average pore diameter of 0.001 to 0.001.
The range of 2.0 μm is for keeping the air permeability and liquid impermeability (liquid barrier property) higher, and the microporous film biaxially oriented as used in claim 4 was used. Is to increase mechanical strength such as puncture strength.

Furthermore, the packing base material is a foam, and the packing base material has a foaming ratio of 1.1 to 5 times and a thickness of 0.5 to 3 mm. A certain closed cell foam is used so that a more suitable packing effect (sealing effect) can be obtained. Also, the sheet material is a wet or dry non-woven fabric as claimed in claim 7 in order to ensure a sufficient gas flow path to be conducted from the surface to the end surface even if the cap closing torque is resisted. is there.

Furthermore, the polyolefin as the material of the microporous film and the packing base material according to claim 8 is
The ethylene polymer, propylene polymer or a mixture thereof has an excellent balance of heat resistance, mechanical strength, water resistance, chemical resistance, etc., and has a finely-sealed, finely-sealed closed-cell sealing property. This is to ensure that

Furthermore, the invention according to claim 9 is characterized in that a microporous polyolefin film having an intrinsic viscosity [η] of 3 dl / g or more, a polyolefin packing base material having gas passages from one surface to another surface, A polyolefin-based sheet material having a gas flow path that conducts to the end face is laminated in this order, and is characterized by thermocompression bonding, in the cap of the container containing the content for generating gas, the microporous film on the content side. When used face-to-face, the gas evolved from the contents escapes the sheet material from that face to the end face along the inner top face of the cap through the gas passages that pass from the face of the microporous film and the packing substrate to the face. While escaping to the outside through the side surface (screw part) of the cap,
It is constructed so that the contents will not leak even if the container falls down.

Here, the polyolefin microporous film (hereinafter sometimes referred to as "microporous film")
The intrinsic viscosity [η] is set to 3 dl / g or more in order to enhance mechanical strength such as piercing strength. Intrinsic viscosity [η]
The upper limit of is not particularly limited, but if it is too high, the melt viscosity becomes high, and it may be difficult to form a film, so that a microporous film having a good appearance may not be obtained. Therefore, usually, 25 dl / g or less preferable. On the other hand, a microporous film having an intrinsic viscosity [η] of less than 3 dl / g tends to be inferior in mechanical strength, and there is a possibility that a packing having good performance cannot be obtained. Practically, 4 dl / g or more is preferable.

The microporous film has a porosity of 25.
%, An air permeability of more than 2000 seconds / 100 cc, and an average pore diameter of less than 0.001 μm are all likely to have poor air permeability. On the other hand, any of those having a porosity of more than 90%, an air permeability of less than 50 seconds / 100 cc, and an average pore size of more than 2.0 μm may be inferior in liquid impermeability. Of course, when the porosity, air permeability, and average pore diameter satisfy the above, a packing having an excellent balance between air permeability and liquid impermeability can be obtained. Further, when a biaxially oriented film is used as the microporous film, the mechanical strength such as the puncture strength becomes more excellent.

The intrinsic viscosity [η] is a value measured at 135 ° C. in a decalin solvent. The measuring method is ASTM D
4020. The film thickness of the microporous film was measured with a film thickness meter (Miniax DH-150 type <manufactured by Tokyo Seimitsu Co., Ltd.>). The average pore size is
The maximum value of the pore diameter measured by a mercury porosimeter (Autoscan 33 <made by Yuasa Ionics>) was used.

The porosity is obtained by measuring the weight of the film, setting the density to 0.95 g / cm 3, and calculating the thickness of the dense film. I asked. Porosity (% by volume) = [(T0-TW) / T0] ×
100 Here, T0 is the actual film thickness determined by a film thickness measuring device, and TW is the film thickness with a porosity of 0% calculated from the weight.

The air permeability is measured by using a standard Gurley Densometer (manufactured by Toyo Seiki Seisaku-sho, Ltd.)
It was measured according to TM D726.

The polyolefin as the raw material of the microporous film is ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1
-A homo- or copolymer of an α-olefin having 2 to 10 carbon atoms such as decene. This raw material may be a single polyolefin or a mixture of two or more kinds of polyolefins having different intrinsic viscosities [η]. In the case of a mixture, a polyolefin having an intrinsic viscosity [η] of less than 3 dl / g may be contained, but it is necessary that the mixture satisfies 3 dl / g or more as a whole.

Among the above polyolefins, a homopolymer of propylene or propylene and 5% by weight or less of α-
A propylene polymer which is a copolymer with an olefin and a homopolymer of ethylene or an ethylene polymer which is a copolymer of ethylene and 5% by weight or less of an α-olefin are preferable. Among them, when the ethylene polymer is laminated on the microporous film and the polyolefin packing substrate, it is particularly preferable because it is easily heat-sealed and can be used for heat sterilization.

As a method for producing the microporous film,
Although not particularly limited, for example, a method of heat-treating a preliminarily obtained biaxially oriented polyolefin film having an intrinsic viscosity [η] of 3 dl / g or more under specific conditions, an intrinsic viscosity [η] of 3 dl / g or more N-
Decane, n-alkanes such as n-dodecane, docosane, tricosane and tetracosane, aliphatic or cyclic hydrocarbon compounds such as liquid paraffin, kerosene and paraffin wax, aromatic hydrocarbons such as naphthalene, tetralin, diethylbenzene and decalin Compounds or hydrogenated derivatives thereof, higher fatty acids such as stearic acid, higher aliphatic alcohols such as stearyl alcohol, higher fatty acid amides such as stearic acid amide, phthalate esters such as dioctyl phthalate, di-n-butyl phthalate, etc. , A non-volatile organic low molecular weight compound, or finely divided silicic acid, calcium silicate, calcium carbonate, inorganic fine powder such as finely divided talc to obtain a sheet-like material, before biaxial stretching of the sheet-like material,
A method is conceivable in which the organic low molecular weight compound or the inorganic fine powder is obtained by removing any of the intermediate or subsequent steps or combining several steps. Of course, it does not limit what you get in other ways.

A more specific method for producing the microporous film is described in JP-A-10-258462 and JP-A-10-258462.
306168, Japanese Patent No. 2711633, Japanese Patent Laid-Open No. 5-234578, Japanese Patent Laid-Open No. 6-212006.
JP-A No. 60-255107 and the like.

As the packing base material, any film or sheet having a cushioning property can be used, but a foam made of a closed-cell foam (which may be an open-cell foam) is preferably selected.

The gas flow path of the polyolefin-based sheet material (hereinafter also referred to as "sheet material") refers to a gap between fibers of the sheet material if the sheet material is, for example, a wet nonwoven fabric or a needle punch type nonwoven fabric. This gap is 40-5
A value of about 0 g / m 2 is sufficient. In other words, it is sufficient if the gas (gas) introduced from the surface side through the microporous polyolefin film can be conducted to the end surface side.

The foam used as the packing base material has a foaming ratio of 1.1 to 5 times (preferably 2 to 3 times),
A closed-cell foam having a thickness in the range of 0.5 to 3 mm (preferably 1 to 2 mm) is preferable because it is excellent in restoring property and sealing property.

The polyolefin used as the raw material of the packing base material is ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1
A homo- or copolymer of an α-olefin having 2 to 10 carbon atoms such as decene, which is usually a high-pressure low-density polyethylene, a linear low-density polyethylene, a medium-density polyethylene, a high-density polyethylene, a polypropylene, a poly-1-butene. ,
It is a low crystalline or amorphous polyolefin such as a crystalline polyolefin known as poly-4-methyl-1-pentene, an ethylene / α-olefin random copolymer, a propylene / α-olefin random copolymer, or the like. These polyolefins may be used alone or as a mixture of two or more kinds. Among them, ethylene polymers such as high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene and homopolymers of propylene or propylene and a small amount of ethylene of 5 mol% or less, 1-butene, etc. The above-mentioned copolymer with α-olefin, so-called polypropylene, is preferred because a propylene polymer is finely divided to obtain a fine-grained foam having uniform closed cells.

The molecular weight of the polyolefin as the raw material of the packing base material is not particularly limited as long as it has a molecular weight such that it can be molded into a foam, but in general, if it is an ethylene polymer, ASTM D1238 (190 °). C,
Melt flow rate (MFR) measured according to a load of 2,160 g) of 0.1 to 50 g / min (preferably, 2 to
The range of 10 g / min) is preferable. If it is a propylene polymer, ASTM D1238 (230 ° C, load 2,
Melt flow rate (MF) measured according to 160 g)
R) is 0.1 to 50 g / min (preferably 0.1 to 10)
Those in the range of g / min) are advantageously used.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an enlarged sectional view of the present packing, FIG. 2 is an enlarged sectional view of a second example of the present packing,
3 is a partially enlarged perspective view of a composite fiber constituting a polyolefin sheet material, FIG. 4 is a perspective view showing a packing and a container equipped with a cap, and FIG. 5 is a sectional view showing a relationship between the packing of the present application and contents. FIG. 6 is a perspective view showing a gas permeation test method.

The packing 1 of the present application, as shown in FIG. 1, is a liquid-impermeable, air-permeable microporous film 2, and a polyolefin sheet material 5 having a gas flow path 4 that conducts from surface to end surface.
It has a three-layer structure in which the polyolefin packing base material 3 and the polyolefin packing base material 3 are laminated in this order and thermocompression bonded. Although not shown, the packing base material 3 may have a five-layer structure of a sheet material 5 having gas channels 4 on both sides thereof in the center and a microporous film 2.

The packing 1 of the present application, as shown in FIG. 2, is a liquid-impermeable, air-permeable microporous film 2, a packing base material 3 having a gas passage 3 ′ that escapes from surface to surface, and conduction from surface to end surface. It may have a three-layer structure in which the sheet material 5 having the gas flow path 4 is laminated in this order and thermocompression bonded.

The polyolefin sheet material 5 is specifically composed of a wet or dry non-woven fabric. This wet non-woven fabric is a sheet-shaped material in which fibers cut to the required length are dispersed in water and lifted up, and many gaps are formed between the entangled fibers, and from the surface side to the end surface side. It is possible to sufficiently secure the gas flow path 4 that is in conduction. Further, the dry non-woven fabric is a sheet formed by forming a web with a carding machine and then entwining the fiber web with a needle punch machine in the thickness direction, and in this case also, many gaps are formed between the entangled fibers. It is possible to sufficiently secure the gas flow path 4 that is formed and conducts from the surface side to the end surface side.

As shown in FIG. 3, each of the fibers constituting the polyolefin sheet material 5 has a core 5a 'made of polypropylene (PP), which is difficult to melt, and is easy to melt LEPE.
+ EVA is used as the sheath fiber 5a ″. When the composite fiber 5a is a wet or dry non-woven fabric, the sheath fiber 5a ″ adheres to the microporous film 2 and the packing substrate 3 during thermocompression bonding. On the other hand, the core portion 5a ', which becomes a medium but is difficult to melt, maintains the state in which the voids are formed, so that the gas flow path 4 that is conducted from the surface side to the end surface side is reliably secured against the closing torque of the cap. it can. Of course, not limited to this,
A wet or dry non-woven fabric may be formed by using a mixed product in which fibers that are difficult to melt and fibers that are easily melted are mixed at a fixed ratio. For example, a 7: 3 mixture of cut fibers of commercially available polypropylene staple fibers with a clamp and cut fibers of EAC (the sheath has a melting point of 110 ° C and the core has a melting point of 160 ° C) may be used.

The present packing (three layers of the microporous film 2 / the sheet material 5 having the gas flow path 4 communicating from the surface to the end surface / the packing base material 3) 1 shown in FIG. 1 is punched as shown in FIG. 4 (a). The microporous film 2 is loaded on the inner top surface of the screw cap 7 that can be screwed into the mouth of the container (bottle) 6 as shown in FIG.

Then, the contents (for example,
A hypochlorous acid aqueous solution, hydrogen peroxide solution, fermentable contents, aromatic agent, etc.) 8 are filled, and the mouth of the container 6 is capped with the cap 7 loaded with the packing 1 of the present application as described above, and fixed. Close with torque. In this case, the gas G generated from the contents 8 in the container 6 permeates the microporous film 2 of the packing 1 of the present application as shown in FIG.
Through a gas flow path (not shown in FIG. 5) from the surface side to the end surface side along the inner surface of the packing base material 3 to the side surface (screw portion 7 ') of the cap 7, and as shown by G'. It will be released into the atmosphere. Therefore, the high pressure inside the container 6 due to the gas G generated from the contents 8 is avoided, and the container is prevented from bursting.

Further, in the screw cap 7 which can be screwed into the mouth portion of the container (bottle) 6, the packing of the present application (microporous film 2 / gas passage 3'to be discharged from surface to surface) shown in FIG.
When a three-layered sheet material 5 having a gas flow path 4 that conducts from the surface 3 to the end surface of the packing base material 3) is loaded so that the microporous film 2 faces the inside of the container, the contents in the container The gas G generated from 8 permeates the microporous film 2 and further permeates a gas passage 3 ′ passing from the surface of the packing base material 3 to the surface thereof to conduct from the surface side of the polyolefin-based sheet material 5 to the end surface side. It passes through the gas flow path (not shown in FIG. 5) along the inner surface of the cap 7 to the side surface (screw portion 7 '), and is discharged into the atmosphere like G'.

The packing 1 of the present application (both shown in FIGS. 1 and 2) is provided in the case where the container 6 filled with the contents 8 which is a gas-prone liquid is tumbled (sideways).
Even if the microporous film 2 gets wet with the liquid content,
Since the liquid impermeability is ensured for a long time, the liquid does not leak.

[0033]

Example 1 Intrinsic viscosity [η] was 5 dl / g and porosity was 63.
%, Air permeability 170 s / 100 cc, thickness 35 μm
The liquid-impermeable, air-permeable microporous film 2 made of polyethylene and the packing base material 3 made of polyethylene closed-cell foam having a foaming ratio of 2 and a thickness of 1.5 mm, and a core 5a 'made of polypropylene. (PP), sheath 5a ″ is LE
5 of composite fiber (2 denier) 5a made of PE + EVA
Three layers were laminated via a polyolefin-based sheet material 5 made of a wet nonwoven fabric (60 g / m 2) obtained by cutting into mm pieces, thermocompression bonded at 160 ° C. for 10 seconds, and punched to obtain a packing 1 of the present application.

Next, the packing 1 of the present application is loaded on the inner top surface of the polypropylene screw cap 7 which can be screwed into the mouth of the polyethylene terephthalate bottle (container) 6. Then the bottle (with air) 6
Then, the cap 7 in which the present packing (any of FIG. 1 and FIG. 2) 1 is loaded is closed and attached with a torque of 20 kg · cm, and as shown in FIG. 6, it is submerged in a transparent container 9 filled with water and the fixture 10 is attached. The air in the upper layer of the transparent container 9 is sucked by a vacuum pump (not shown) through the suction pipe 11 and the air bubbles K retained in the bottle (container) 6 come out from the side of the cap 7. A gas permeation test was carried out depending on whether or not.

Further, 100 cc of 12% sodium hypochlorite aqueous solution was put in the bottle 6, the cap 7 in which the packing 1 of the present application was loaded as described above was closed, and the torque was 20 kg.
A liquid leakage test was carried out depending on whether or not the aqueous solution leaked from the side of the cap 7 after lying on its side in a cm position and left at 35 ° C. for 1 week.

[0036]

Example 2 Intrinsic viscosity [η] is 5 dl / g and porosity is 63.
%, Air permeability 170 s / 100 cc, thickness 35 μm
A liquid-impermeable, breathable microporous film 2 made of polyethylene, and a packing base material 3 made of polyethylene closed-cell foam having a foaming ratio of 2 and a thickness of 1.5 mm are commercially available with a clamp. Material made from polypropylene staple fiber (2 denier) cut 2 inches 70%
And EAC (the sheath has a melting point of 110 ° C and the core has a melting point of 160).
30% of 2.2 inch cut fiber (2 denier) of ° C)
A web obtained by mixing and is laminated in three layers with a polyolefin sheet material 5 made of a non-woven fabric (40 g / m 2) obtained by needle punching, at 110 ° C. for 10 s.
It was thermocompression bonded with ec and punched to obtain the present packing 1.

Next, the packing 1 of the present application is loaded on the inner top surface of the polypropylene screw cap 7 which can be screwed into the mouth of the polyethylene terephthalate bottle (container) 6. Then, the bottle 6 was filled with a 12% sodium hypochlorite aqueous solution and the cap 7 loaded with the packing 1 of the present application was closed and mounted with a torque of 20 kg · cm, and the gas permeation test was conducted under the same conditions and methods as in Example 1. And a liquid leak test was conducted.

In the above-mentioned gas permeation test, it was found that in both Example 1 and Example 2, the bubble K rose from the side of the cap 7 and gas permeated. Also, in the liquid leak test, 3
There was no leakage even after 1 week at 5 ° C. Therefore, it was confirmed that the packing 1 of the present application is excellent.

[0039]

As described above, according to the present invention, a gas that takes in a polyolefin microporous film having an intrinsic viscosity [η] of 3 dl / g or more and a polyolefin packing base material from the surface side and conducts them to the end surface side. Since it is characterized by thermocompression bonding through a polyolefin-based sheet material having a flow path, in the cap of the container containing the contents to generate gas, when used so that the microporous film faces the contents side , The gas generated from the contents permeates the microporous film, escapes the sheet material from that surface to the end surface along the inner surface of the packing base material, and escapes to the outside through the side surface (screwed portion) of the cap, and the container It has the excellent effect that the contents will not leak when it falls.

Further, in the breathable packing according to the invention described in claim 2, the microporous film has a porosity of 25 to 9
0%, air permeability 50-2000 seconds / 100cc and thickness 1
Since it is in the range of 0 to 200 μm, there is an excellent effect that the performance of air permeability and liquid impermeability (liquid blocking property) can be kept higher.

Furthermore, in the breathable packing according to the invention of claim 3, the microporous film has an average pore size of 0.
Since it is in the range of 001 to 2.0 μm, the air permeability and liquid impermeability (liquid barrier property) can be kept higher, and when the hole diameter of the microporous film is 0.1 μm or less. Has an excellent effect that it can be used for food and can prevent the invasion of bacteria.

Further, in the breathable packing according to the invention described in claim 4, since the microporous film is biaxially oriented, the excellent effect that the mechanical strength such as the puncture strength is further increased. Play.

Furthermore, in the breathable packing according to the invention described in claim 5, since the packing base material is a foam, the packing effect (sealing effect) in the close contact portion between the container and the cap is more preferable. It has an excellent effect of being obtained in a state.

Further, in the air-permeable packing according to the invention described in claim 6, the packing base material has an expansion ratio of 1.
Since it is a closed cell foam having a thickness of 1 to 5 times and a thickness of 0.5 to 3 mm, when the cap is closed in the container,
The excellent effect that the required packing effect (sealing effect) is obtained in a more suitable state is exhibited.

Furthermore, in the air-permeable packing according to the invention described in claim 7, since the sheet material is a wet non-woven fabric or a dry non-woven fabric, many gaps are formed between the entangled fibers, and the face side to the end face are formed. An excellent effect is obtained in that the gas flow path 4 that conducts to the side can be sufficiently secured.

Furthermore, in the air-permeable packing according to the invention described in claim 8, the polyolefin as a material of the microporous film and the packing substrate is an ethylene polymer, a propylene polymer or a mixture thereof, It has an excellent balance of heat resistance, mechanical strength, water resistance, chemical resistance, and the like, and has an excellent effect of obtaining a fine wood-like sealing property composed of fine and uniform closed cells.

Further, the breathable packing according to the invention of claim 9 is a polyolefin packing base material having a polyolefin microporous film having an intrinsic viscosity [η] of 3 dl / g or more, and a gas passage that escapes from surface to surface. And a polyolefin-based sheet material having a gas flow path that conducts from the surface to the end surface are laminated in this order, and thermocompression bonding is performed, so that the contents of the container are stored in a cap of a container containing the contents for generating gas. When used so that the microporous film faces the side, the gas generated from the contents passes through the gas passages that pass from the surface of the microporous film and the packing substrate to the surface of the sheet material, and from the surface to the end surface of the inside of the cap. It escapes along the top surface and escapes to the outside through the side surface (screw part) of the cap, and the contents do not leak when the container falls down. Cormorant an excellent effect.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of the present packing.

FIG. 2 is an enlarged cross-sectional view showing a second example of the present packing.

FIG. 3 is a partially enlarged perspective view of a composite fiber that constitutes a polyolefin sheet material.

4A and 4B are perspective views showing the packing of the present application and a container with a cap attached, where FIG. 4A is the packing of the present application and FIG.

5 is a cross-sectional view showing the relationship between the present packing and the contents in the container, FIG. 5 (a) is a usage example of the present packing of FIG.
(B) is a usage example of the present packing of FIG.

FIG. 6 is a perspective view showing a gas permeation test method.

[Explanation of symbols]

1 This application packing 2 Porous film 3 packing base materials Gas passage from surface 3'to surface Gas flow path from 4 faces to the end face 5 Polyolefin sheet material 5a composite fiber 5a 'core 5a ″ sheath 6 containers 7 cap 7'screw part 8 contents 9 transparent containers 10 Fixture 11 Suction pipe K bubbles

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Claims (9)

[Claims] 1. A polyolefin microporous film having an intrinsic viscosity [η] of 3 dl / g or more, a polyolefin-based sheet material having a gas flow path that conducts from a surface side to an end surface side, and a polyolefin packing base material are laminated in this order. Breathable packing that is characterized by being thermocompression bonded. 2. The microporous film has a porosity of 25 to 9
0%, air permeability 50-2000 seconds / 100cc and thickness 1
It is in the range of 0 to 200 μm.
Breathable packing as described in. 3. The microporous film has an average pore size of 0.0
The air-permeable packing according to claim 1 or 2, which is in the range of 01 to 2.0 µm. 4. The breathable packing according to claim 1, wherein the microporous film is biaxially oriented. 5. The breathable packing according to claim 1, wherein the packing base material is a foam. 6. The expansion ratio of the packing base material is 1.1.
The breathable packing according to claim 1, which is a closed cell foam having a thickness of 0.5 to 3 times and a thickness of 0.5 to 3 mm. 7. The breathable packing according to claim 1, wherein the sheet material is a wet type nonwoven fabric or a dry type nonwoven fabric. 8. The polyolefin, which is a material of the microporous film and the packing substrate, is an ethylene polymer,
Breathable packing according to one of claims 1 to 7, characterized in that it is a propylene polymer or a mixture thereof. 9. A polyolefin microporous film having an intrinsic viscosity [η] of 3 dl / g or more, a polyolefin packing base material having gas passages that pass from one surface to another surface, and a polyolefin having a gas flow path that conducts from the surface to the end surface. A breathable packing characterized by being laminated with a sheet material in this order and thermocompression bonded.