JP5544552B2 - Laminate for gas collection bag and gas collection bag using the laminate - Google Patents

Description

  The present invention relates to a gas collection bag laminate and a gas collection bag comprising the laminate, and more particularly, to a gas collection bag laminate used for conveying a sample gas and the laminate. Related to the gas collection bag.

  Conventionally, volatile organic compound gas generated from parts, building materials, furniture, synthetic resin products, etc. constituting automobile bodies, harmful gases emitted from factories such as chemical plants, and gas such as fragrance components of perfume (Hereinafter generically referred to as VOC gas, etc. VOC is an abbreviation for volatile organic compounds.) Components are being measured. These components such as VOC gas are measured by a measuring device such as VT-SHED (Variable Temperature Shield Housing for Evaporative Determination) (Patent Document 1).

  The measuring method of the VOC gas or the like by the measuring device described above is after the measuring device is arranged in a place where the VOC gas or the like to be measured exists, and the VOC gas or the like to be measured is accommodated in the measuring chamber of the measuring device forming the sealed space For example, the temperature in the measurement chamber is changed in accordance with the time-temperature curve defined in the standard, and the components evaporated in the measurement chamber during this time are measured.

  However, when it is difficult to directly store VOC gas or the like to be measured in the measurement chamber of the measuring apparatus, for example, when measuring VOC gas or the like in the atmosphere, the collected sample gas is stored in the measuring apparatus. A gas collection bag for transporting to a certain location is required. As such a collection bag, a general-purpose product using a material in which a polyethylene film, an aluminum foil, and polyethylene terephthalate (PET) are laminated, a Tedlar (registered trademark) film made of a vinyl fluoride resin, and the like are used.

JP 2007-315868 A

  In the bag material of the gas collection bag for transportation, until the VOC gas collected in the remote place is transported to the measuring device, the gas that has been stored is not lost, and the gas barrier property that does not change its properties, Storage performance such as VOC gas such as gas non-adsorbing property in which the bag body does not adsorb VOC gas or the like is required. In particular, in recent years, there has been a demand for more accurate measurement of VOC gas and the like due to stricter regulations on harmful gases and improvements in the accuracy of measuring instruments. Therefore, the material for the gas collection bag needs higher storage performance such as VOC gas. It is also necessary to have strength that can withstand external forces such as piercing and rubbing during transportation, and flexibility that does not hinder gas collection.

  However, there is no gas collection bag that has high storage performance such as VOC gas required for high-precision measurement, and is excellent in strength and flexibility, and is replaced with a general-purpose product used for other purposes. Currently. For example, a conventional gas collection bag with a polyethylene layer as the inner layer can produce a sealed bag due to the heat-welding property of polyethylene, but polyethylene tends to adsorb gas and has a low gas barrier property. Since the gas stored in the bag continuously flows out, accurate measurement results cannot be obtained. In such a gas collection bag, aluminum foil is laminated in order to improve gas barrier properties. However, since aluminum foil has low strength and flexibility, it is necessary to further laminate PET or the like on the outside thereof.

  In addition, those using a vinyl fluoride resin film such as Tedlar (registered trademark) are relatively easy to permeate gas, so the gas barrier property is not sufficient. Phenol, dimethylacetamide, etc. are scattered from the resin itself. Therefore, accurate measurement results cannot be obtained. In order to reduce this, a baking process at about 140 ° C. for about 4 hours is required before use. Furthermore, since it has the property of easily transmitting light such as sunlight, the stored VOC gas or the like may be altered by the light. Furthermore, since the softness is low and hard, it is difficult to handle. For this reason, when collecting VOC gas or the like, a pinhole or the like is easily damaged during transportation, and the workability to a bag body is inferior because it is difficult to adhere.

  In addition, the gas collection bag for conveyance is different from the bag for pressure absorption proposed in Patent Document 1. A plurality of pressure absorption bags of Patent Document 1 are incorporated into the measurement chamber for the purpose of keeping the internal pressure of the sealed large-capacity measurement chamber constant, but (surface area of the pressure absorption bag) / ( Since the volume ratio of the measurement chamber is small, the storage performance such as high VOC gas required for the transport gas collection bag is not required. Moreover, the strength and flexibility required at the time of conveyance are not required. Therefore, the gas storage bag provided in the measuring device, such as the pressure absorbing bag, and the gas collection bag premised on conveyance are clearly distinguished in terms of storage performance such as VOC gas, strength, and flexibility.

  In short, on the premise of transport, there has never been a gas collection bag capable of holding the composition of the sample gas contained in the bag for a long time, and has not been studied.

  The present invention has been made in view of the above problems, and is a laminated material for a gas collection bag excellent in storage performance, strength, and flexibility, such as VOC gas required for a gas collection bag for conveyance, and the An object is to provide a gas collection bag using a laminated material.

  The laminated material for a gas collection bag of the present invention is a laminated material for a gas collection bag used for conveying a sample gas, and an ethylene vinyl alcohol copolymer (A) having an ethylene content of 35 to 55 mol%. ) And an outer layer made of an ethylene vinyl alcohol copolymer (B) having an ethylene content of 25 to 35 mol%.

  Moreover, it is preferable that the thickness of the said inner layer is 15-50 micrometers, and the thickness of the said outer layer is 8-20 micrometers.

  It is preferable that an outermost layer made of nylon 6, polyethylene terephthalate or polypropylene is further laminated on the outer side of the outer layer.

  Further, an outermost layer made of an ethylene vinyl alcohol copolymer (C) having the same ethylene content as the ethylene vinyl alcohol copolymer (A) or lower than the ethylene vinyl alcohol copolymer (A) is formed outside the outer layer. Furthermore, it is preferable to laminate.

  Moreover, it is preferable that an aluminum vapor deposition layer is further laminated on at least one surface of the outer layer.

  The gas collection bag of the present invention is a gas collection bag used for conveying a sample gas, and uses a laminated material for a gas collection bag so that the inner layer is an inner surface of the gas collection bag. It is characterized by becoming.

  Since the laminated material for a gas collection bag of the present invention is excellent in storage performance such as VOC gas such as gas barrier property and gas non-adsorption property, the composition of the sample gas contained in the gas collection bag hardly changes over a long period of time. Moreover, since the ethylene vinyl alcohol copolymer (A) used as an inner layer has the outstanding heat-welding property, it is excellent in workability. Furthermore, since the laminated material is excellent in strength and flexibility, it is easy to handle and is not easily damaged.

  In addition, the laminated material for gas collection bags with the outermost layer laminated has the strength to withstand external forces such as piercing and rubbing during transportation, so that pinholes and other damage are unlikely to occur and hinder gas collection. Flexibility to the extent that it does not come. In addition, when ethylene vinyl alcohol copolymer (C) is used for the outermost layer, the inner layer surface and the outermost layer surface can be directly heat-welded when the bag body is manufactured, and the gas collection bag can be easily manufactured. become.

  According to the gas collection bag of the present invention, since the laminated material used is excellent in storage performance such as VOC gas, the composition of the stored sample gas can be maintained for a long time. Moreover, since it is excellent in strength and flexibility, it can withstand external forces such as piercing and rubbing during transportation. Therefore, damage such as pinholes hardly occurs, and the sample gas can be safely transported to the measuring device.

It is the schematic cross section which showed 1st Embodiment of the laminated material for gas collection bags of this invention. It is the schematic cross section which showed 2nd Embodiment of the laminated material for gas collection bags of this invention. It is the schematic cross section which showed 3rd Embodiment of the laminated material for gas collection bags of this invention.

  As shown in FIG. 1, the laminated material for a gas collection bag of the present invention has an inner layer 10 made of an ethylene vinyl alcohol copolymer (A) having an ethylene content of 35 to 55 mol%, and an ethylene content of 25 to 25. It is a laminated film which laminates | stacks the outer layer 11 which consists of 35 mol% ethylene vinyl alcohol copolymer (B) in order from the inner side of a gas collection bag.

  In the present invention, the ethylene vinyl alcohol copolymer (A), the ethylene vinyl alcohol copolymer (B) and the ethylene vinyl alcohol copolymer (C) described later refer to a saponified product of an ethylene vinyl acetate copolymer. Unlike polyethylene, the ethylene vinyl alcohol copolymer is thought to have hydroxyl groups randomly in the polymer chain, and these hydroxyl groups are attracted by hydrogen bonds. Therefore, it is considered that molecular motion is suppressed, entry of VOC gas or the like between polymer chains is suppressed, and gas barrier properties and gas non-adsorption properties are better than those of polyethylene.

  The degree of saponification of the ethylene vinyl alcohol copolymers (A), (B) and (C) is not particularly limited, but is preferably 90 mol% or more, more preferably 98 mol% or more, Preferably it is 99 mol% or more. If the degree of saponification is less than 90 mol%, the gas barrier property tends to decrease.

  Although the thickness of the whole laminated material for gas collection bags of this invention is not specifically limited, Preferably it is 25-150 micrometers, More preferably, it is 40-100 micrometers. If the thickness is less than 25 μm, there is a tendency that sufficient strength as a gas collection bag cannot be obtained, and if it exceeds 150 μm, the flexibility tends to be lowered, so that it tends to be difficult to handle.

  The inner layer of the gas collecting bag laminate of the present invention is a layer located inside the gas collecting bag, one surface of the inner layer is in contact with the sample gas contained in the gas collecting bag, and the other surface is the outer layer. Adhere to. Moreover, the airtightness of a bag is acquired by making the inner layers of a laminated material oppose and heat-welding at the time of manufacture of a gas collection bag. Although the thickness of an inner layer is not specifically limited, Preferably it is 15-50 micrometers, More preferably, it is 15-40 micrometers, Most preferably, it is 15-35 micrometers. If the thickness is less than 15 μm, lamination processing becomes difficult, and the heat welding strength tends to be insufficient, and if it exceeds 50 μm, flexibility tends to be impaired.

  The inner layer mainly contains an ethylene vinyl alcohol copolymer (A) having an ethylene content of 35 to 55 mol%, and if necessary, an ethylene vinyl acetate copolymer and its partially saponified product, titanium oxide, calcium carbonate, etc. Other components such as inorganic fillers and pigments can be added. The content of the ethylene vinyl alcohol copolymer (A) in the inner layer is not particularly limited, but is preferably 90% by weight or more, more preferably 95% by weight or more, and most preferably 100% by weight.

  The ethylene vinyl alcohol copolymer (A) is a copolymer having an ethylene content of 35 to 55 mol%. The ethylene content is preferably 40 to 50 mol%. When the ethylene content is less than 35 mol%, the heat weldability is lowered, and the heat weldability with the outer layer and the airtightness of the bag tend to be lowered. When the ethylene content exceeds 55 mol%, it becomes easy to adsorb the VOC gas and the like contained in the gas collection bag, and after the adsorption, the VOC gas etc. moves to the end face of the inner layer and is dissipated therefrom, so accurate measurement is possible. There is a tendency to be impossible, and gas barrier properties tend to be lowered.

  The outer layer of the laminated material for a gas collection bag of the present invention is a layer located outside the gas collection bag with respect to the inner layer, the inner layer is bonded to one surface of the outer layer, and the other surface is a gas collection Look to the outside of the bag. Although the thickness of an outer layer is not specifically limited, Preferably it is 8-20 micrometers. If the thickness is less than 8 μm, it is difficult to laminate the inner layer, the strength of the outer layer tends to decrease, and there is a tendency that sufficient gas barrier properties cannot be obtained. If the thickness exceeds 20 μm, flexibility is lost, and pinholes and the like are damaged. It tends to occur.

  The outer layer mainly contains an ethylene vinyl alcohol copolymer (B) having an ethylene content of 25 to 35 mol%. If necessary, the ethylene vinyl acetate copolymer and its partially saponified product, titanium oxide, calcium carbonate, etc. Other components such as inorganic fillers and pigments can be added. The content of the ethylene vinyl alcohol copolymer (B) in the outer layer is not particularly limited, but is preferably 90% by weight or more, more preferably 95% by weight or more, and most preferably 100% by weight.

  The ethylene vinyl alcohol copolymer (B) is a copolymer having an ethylene content of 25 to 35 mol%. The ethylene content is preferably 28 to 33 mol%. If the ethylene content is less than 25 mol%, film formation is difficult. When the ethylene content exceeds 35 mol%, the gas barrier property is lowered, so that the sample gas in the bag tends to dissipate outside the bag, and VOC gas tends to enter from the outside of the bag, and the gas non-adsorption property also decreases. Tend to.

  Moreover, it is preferable to form an aluminum vapor deposition layer in any one surface in an outer layer. FIG. 2 is a schematic cross-sectional view showing an example of a laminated material for a gas collection bag in which an aluminum vapor deposition layer is formed. The laminated material for a gas collection bag 1 is formed by laminating an inner layer 10, an outer layer 11, and an outermost layer 13 described later. An aluminum vapor deposition layer 12 is formed between the outer layer 11 and the outermost layer 13. This not only enhances the gas barrier property, but also prevents the VOC gas or the like from being altered by light. Although the thickness of the aluminum vapor deposition layer 12 is not specifically limited, Preferably it is 300-800 mm, More preferably, it is 400-600 mm. If the thickness is less than 300 mm, the desired performance tends not to be ensured, and if it exceeds 800 mm, it tends to peel off from the base film due to bending.

  In order to protect the inner layer and the outer layer, the outermost layer made of a synthetic resin can be further laminated on the outer side of the outer layer in the gas collecting bag laminate of the present invention. FIG. 3 is a schematic cross-sectional view of a gas collection bag laminated material in which an outermost layer is laminated. The gas collection bag laminated material 1 has a structure in which an inner layer 10, an outer layer 11, and an outermost layer 13 are laminated in order. The outermost layer is preferably a biaxially stretched film that is excellent in strength and easily available.

  Although the thickness of an outermost layer is not specifically limited, Preferably it is 5-50 micrometers, More preferably, it is 10-40 micrometers, Most preferably, it is 12-30 micrometers. If the thickness is less than 5 μm, the strength tends to be low and tends to be damaged by piercing or rubbing during transportation, and if it exceeds 50 μm, the flexibility tends to be impaired and the handling tends to be difficult.

  Examples of the synthetic resin used for the outermost layer include polyamides such as polyethylene terephthalate (PET) and nylon 6, polypropylene, polyester, polycarbonate, poly (meth) acrylate, polystyrene, polyurethane, and the like. These can be used alone or in combination. Among these, PET, nylon 6 and polypropylene, which are excellent in strength and flexibility and easily available, are preferable. Moreover, other components, such as inorganic fillers, such as a titanium oxide and a calcium carbonate, and a pigment, can be added to a synthetic resin as needed. The content of the synthetic resin in the outermost layer is not particularly limited, but is preferably 90% by weight or more, more preferably 95% by weight or more, and most preferably 100% by weight.

  Moreover, an ethylene vinyl alcohol copolymer (C) can be used for the outermost layer. As a result, the inner layer surface and the outermost layer surface can be directly heat-welded when the bag body is manufactured, and the gas collection bag can be easily manufactured. The ethylene vinyl alcohol copolymer disposed in the outermost layer may be the same as that disposed in the inner layer, but the ethylene content is lower than that of the ethylene vinyl alcohol copolymer (A), so that the heat welding workability is improved. It is preferable at the point which can improve, and it is more preferable to use a low thing within the range of 1-5 mol%.

  As a method for producing a laminated material for a gas collection bag of the present invention, that is, a method of laminating an inner layer, an outer layer and, if necessary, an outermost layer, known methods such as a dry laminating method, an extrusion laminating method, a coextrusion laminating method Can be adopted. A polyurethane or polyimide adhesive may be used for bonding.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.

Example 1
Eval film EF-HS (trade name, manufactured by Kuraray Co., Ltd., ethylene mol%: 47 mol%, thickness: 30 μm) is used for the inner layer material, and Eval film EF-XL (trade name, Kuraray Co., Ltd.) is used for the outer layer material. Made of ethylene, mol%: 32 mol%, thickness: 12 μm), and both were sequentially laminated by a dry laminating method to obtain a laminated material for gas collection bag. The following tests were performed on the obtained laminated material.

(Measurement of amount of spread)
Using the obtained laminated material, a bag body having dimensions of 350 mm × 170 mm × 500 mm was produced by an impulse heat sealer, and high purity nitrogen gas was sealed in the bag body, and the amount of springing out after 24 hours was measured. GC / FID (gas chromatograph using a flame ionization detector). The results are shown in Table 1.

(VOC gas concentration retention rate)
Using the obtained laminated material, an impulse-type heat sealing machine is used to produce a sealed gas collection bag with dimensions of 350 mm × 170 mm × 500 mm, and a standard gas composed of 24 types of components having approximately the same concentration (1000 ppb) is used. It enclosed with this gas collection bag. After storing it for a certain time, the gas concentration in the bag was measured by GC / FID. Benzene, toluene, metaxylene and styrene were selected as representative examples of gas, and the residual rate after 6 hours was determined. The results are shown in Table 1.

(Tensile test)
A strip-shaped test piece having a length of 200 mm and a width of 10 mm is cut out from the produced laminated material, and this test piece is perpendicular to the flow direction of the laminated material (hereinafter abbreviated as MD) and the flow direction of the laminated material ( Hereinafter, it was cut out in two directions (hereinafter abbreviated as TD), and the tensile strength was determined according to JIS K-7127. The results are shown in Table 1.

(Puncture strength)
About the laminated material of Example 3 mentioned later and the Tedlar (registered trademark) film of Comparative Example 2, a test piece of 100 mm × 100 mm was cut out from the produced laminated material, clamped with a ring-shaped holder, and the center part was a steel needle ( The resistance when pierced with a thickness of 1 mmφ and a sphere with a tip of 0.5R was determined, and this was taken as the piercing strength. The results are shown in Table 1.

(Bend resistance test)
A test piece of 300 mm × 210 mm (approximately A4 size) is cut out from the produced laminated material, this test piece is set on a gelbo flex tester (manufactured by Rigaku Industry Co., Ltd.), a predetermined bending is repeated a certain number of times, and it is removed. The number of pinholes generated was counted. This test is performed for various bend times, and the number of bends (hereinafter abbreviated as N _{p = 1} ) where the first pinhole will occur is statistically determined from the relationship between the number of bends and the number of generated pinholes. It was. The results are shown in Table 1.

Example 2
The same inner layer material as in Example 1 was used, Eval Film EF-XL (trade name, manufactured by Kuraray Co., Ltd., ethylene mol%: 32 mol%, thickness: 15 μm) was used for the outer layer material, and the outermost layer material was further used. Bonile (trade name: nylon 6 film manufactured by Ube Industries, Ltd., thickness: 15 μm) was used, and each was sequentially laminated by a dry laminating method to obtain a laminated material for gas collection bags. The obtained laminate was tested in the same manner as in Example 1. The results are shown in Table 1.

Example 3
Lamination for gas collection bag by the same method as in Example 2 except that Eval film EF-E (trade name, manufactured by Kuraray Co., Ltd., ethylene mol%: 44 mol%, thickness: 20 μm) was used as the inner layer material. The material was obtained. The obtained laminate was tested in the same manner as in Example 1. The results are shown in Table 1.

Example 4
For gas collection bag in the same manner as in Example 2 except that Eval film EF-E (trade name, manufactured by Kuraray Co., Ltd., ethylene mol%: 44 mol%, thickness: 30 μm) was used as the outermost layer material. A laminate was obtained. The obtained laminate was tested in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1
The same method as in Example 1 except that polyethylene (manufactured by Tosero Co., Ltd., thickness: 80 μm) was used for the inner layer material, and polyethylene (manufactured by Tosero Co., Ltd., thickness: 80 μm) was used for the outermost layer material. The laminated material for gas collection bags was obtained. The obtained laminate was tested in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2
A Tedlar (registered trademark) film (trade name, manufactured by Dupont, thickness: 50 μm) was used as a gas collection bag material. The test similar to Example 1 was done about this Tedlar (trademark) film. The results are shown in Table 1.

  As shown in Table 1, it can be seen that the amount of gas in terms of methane in the ethylene vinyl alcohol copolymer film is an order of magnitude lower than that of polyethylene or Tedlar (registered trademark) film. From this result, it can be seen that the laminate of the ethylene vinyl alcohol copolymer is suitable for a gas collection bag for high accuracy analysis. Further, in Examples 1 to 4 in which ethylene vinyl alcohol copolymer films were used for the inner layer and the outer layer, and ethylene vinyl alcohol copolymer films having an ethylene content of 44 mol% and 47 mol% were used for the inner layer, the measurement was performed. The concentration retention of all components was 100%. On the other hand, in Comparative Example 2 using a Tedlar (registered trademark) film, the concentration retention rate of all the measured components was 90 to 98%. From these results, it can be seen that those using a laminate made of an ethylene vinyl alcohol copolymer are excellent in gas barrier properties and gas non-adsorption properties.

  In addition, a laminate composed of two ethylene vinyl alcohol copolymer films has a tensile strength of 3.9 for MD and 3.0 for TD, and is equivalent to a laminate of polyethylene film or Tedlar (registered trademark) film. It can be seen that it has strength. A laminate composed of three layers of an ethylene vinyl alcohol copolymer film has a tensile strength of 5.2 to 8.3 in MD and 3.7 to 6.7 in TD, and is a laminate of polyethylene film or Tedlar (registered trademark). ) Excellent tensile strength compared to film. Furthermore, it can be seen that the laminated material (Example 3) in which the inner layer and the outer layer are ethylene vinyl alcohol copolymer films and the outermost layer is nylon 6 is excellent in piercing strength as compared with the Tedlar (registered trademark) film. Furthermore, regarding the bending resistance, the Tedlar (registered trademark) film was 180 times, whereas the ethylene vinyl alcohol copolymer film laminate was 330 to 430 times. From these results, it can be seen that the laminate of the ethylene vinyl alcohol copolymer film is relatively thin and therefore excellent in flexibility and has sufficient strength as a laminate for a gas collection bag for transportation.

DESCRIPTION OF SYMBOLS 1 Laminated material for gas collection bags 10 Inner layer 11 Outer layer 12 Aluminum vapor deposition layer 13 Outermost layer

Claims (5)

A laminated material for a gas collection bag used for conveying a sample gas,
An inner layer having a thickness of 15 to 50 μm in contact with the sample gas comprising an ethylene vinyl alcohol copolymer (A) having an ethylene content of 35 to 55 mol%;
A laminate for a gas collection bag, which is formed by laminating an outer layer having a thickness of 8 to 20 μm made of an ethylene vinyl alcohol copolymer (B) having an ethylene content of 25 to 35 mol%. The outside of the outer layer, nylon 6, polyethylene terephthalate or of polypropylene formed by further laminating the outermost claim 1 Symbol placement gas collecting bag laminate of. An outermost layer made of an ethylene vinyl alcohol copolymer (C) having the same ethylene content as the ethylene vinyl alcohol copolymer (A) or lower than the ethylene vinyl alcohol copolymer (A) is further laminated on the outer side of the outer layer. and comprising claim 1 Symbol placement gas collecting bag laminate of. The laminated material for gas collection bags according to any one of claims 1 to 3 , wherein an aluminum vapor deposition layer is further laminated on at least one surface of the outer layer. A gas collection bag used to transport sample gas,
A gas collection bag formed by using the laminated material for a gas collection bag according to any one of claims 1 to 4 so that the inner layer is an inner surface of the gas collection bag.

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