JP2009128223A - Gas collection bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas collection bag of gas manufactured in stable quality. <P>SOLUTION: This gas collection bag has a bung hole for injecting and/or discharging sampled gas. The bag body of the collection bag is formed by heat-sealing a laminated body 3 made of only polyester resin where a substrate film 1 made of polyester resin and a sealant 2 made of polyester resin are stacked. Preferably, the laminated body 3 is formed by extrusion-laminating the sealant 2 made of polyester resin on a biaxial stretching polyethylene terephthalate film without interposing an anchor agent layer. Preferably, the polyester resin of the sealant 2 is isophthalic acid modified polyethylene terephthalate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a collection bag used for collecting a gas during inspection of a volatile organic compound (VOC) or the like.

Conventionally, as a gas collection bag, since it is difficult to adsorb trace components such as VOC in the gas, a polyester resin such as polyethylene terephthalate (PET) or a fluorine resin film such as polyvinyl fluoride (PVF) is used. A bag is used. Among them, bags made of a polyester film are frequently used because they are easily available and excellent in cost, and high mechanical strength can be obtained by stretching.
In Patent Document 1, an adhesive having a weak odor is applied to the entire outer surface of the polyester film, and the first film tape is overlaid on the surface, and a strong adhesive is further used thereon. A pollution gas collecting bag is described in which a second film tape is stacked and pasted to close the periphery of the opening.
Patent Document 2 describes a method for thermally bonding a polyester film by heating and melting a polyester film, and then quickly separating the heating body.
In Patent Document 3, a melt-bonded portion is formed at the peripheral portion of a bag body made of a polyester film, and the peripheral portion is reversed and bonded to the same surface via a double-sided adhesive tape piece to form a bent adhesive portion. A bag body for collecting pollutant gas or the like that is formed and has a bent adhesive portion surrounded by a single-sided adhesive tape and covered is described.
Japanese Utility Model Publication No. 48-88787 JP 52-105976 A Japanese Patent Laid-Open No. 1-153936

  As described in Patent Documents 1 and 3, in the method using an adhesive or a pressure-sensitive adhesive tape, the structure is complicated because the tapes are overlapped, the manufacturing of the collection bag is cumbersome, the cost increases, and the adhesive There is a possibility that the solvent used for the adhesive or the like may enter the inside of the bag and affect the gas to be inspected. In addition, depending on the purpose of the collection bag and the purpose of the inspection, it is not desirable to use an adhesive or pressure-sensitive adhesive in accordance with government regulations (for example, “Measurement of Volatile Organic Compound Concentration” of Ministry of the Environment Notification No. 61). There is a case.

  As described in Patent Document 2, in the method of heat-sealing while melting and cutting a film (so-called “melt-sealing seal”), only a slight width of the cut edge of the film can be fused. As described in [Prior Art] of Reference 3, the dispersion of the fusion strength is large and the quality of the collection bag is not stable, so the heat fusion part peels off during gas collection or transportation and breaks. There is a problem that it is easy to do.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the gas collection bag which can be manufactured with stable quality.

  In order to solve the above problems, the present invention provides a gas collection bag having a spout for injecting and / or discharging a sampled gas, wherein the bag body of the collection bag is made of a polyester resin. Provided is a collection bag characterized in that a laminated body made only of a polyester resin in which a film and a sealant made of a polyester resin are laminated is heat-sealed.

In the present invention, the laminate is preferably obtained by extrusion laminating a biaxially stretched polyethylene terephthalate film with a sealant made of a polyester resin without interposing an anchor agent layer.
The polyester resin of the sealant is preferably isophthalic acid-modified polyethylene terephthalate.

It is preferable that at least one corner of the bag main body is provided with a heat-sealing portion that separates the corner from the storage portion of the bag main body, and a hole is provided at the corner divided by the heat-sealing portion.
It is preferable that the periphery of the hole is heat-sealed.
It is preferable that at least a joining base part joined to the bag body of the spout is made of polyethylene terephthalate, and the joining base part is heat-sealed with a sealant of the bag body.
The bag body is preferably a gusset bag.

According to the present invention, since no adhesive or pressure-sensitive adhesive is used in the production of the collection bag, there is no possibility that the solvent or the like used in the bag will enter the bag and affect the gas to be inspected. Moreover, since heat sealing is performed using a sealant, the heat sealing work is easier and the degree of freedom is higher than that of a fusing seal. For this reason, for example, since a heat-welded portion having a predetermined width can be formed, it is possible to perform heat fusion while suppressing variation in strength. Moreover, a heat welding part can be formed in the arbitrary positions of the bag main body away from the edge of the film. Thus, the corner of the bag body can be separated from the gas storage portion via the heat-sealing portion, and a hole for passing a string, a ring, or the like can be provided in the corner, so that a plurality of collection bags can be conveyed. Becomes easier. Moreover, since the periphery of the hole of the formed corner part can be heat-sealed, if this is heat-sealed, the circumference | surroundings of a hole will be reinforced and it will not be torn.
Furthermore, if the joint base of the spout is molded with polyester resin, it can be heat-sealed with the sealant of the laminate, making it easy to install with high airtightness around the spout. The mounting strength is also high.
And since the laminated body used by this invention can heat-seal easily between sealants compared with base film, it is easy to make a bag in a gusset bag. If the collection bag is a gusset bag, the volume can be reduced when empty, and the shape is close to a hexahedron after gas collection, which is convenient for storage and transportation.

  The present invention will be described below with reference to the drawings based on the best mode. FIG. 1 is a cross-sectional view showing an example of a laminated body constituting a bag body of a collection bag according to the present invention. FIG. 2 is a plan view showing a first embodiment of the collection bag according to the present invention. FIG. 3 is an explanatory view showing a state in which a plurality of collection bags shown in FIG. 2 are connected by a string. FIG. 4 is a plan view showing a second embodiment of the collection bag according to the present invention. FIG. 5 is a drawing showing a third embodiment of the collection bag according to the present invention, in which FIG. 5 (a) is a plan view and FIG. 5 (b) is a perspective view. 6A and 6B are drawings showing a fourth embodiment of the collection bag according to the present invention, in which FIG. 6A is a plan view and FIG. 6B is a perspective view.

  The collection bag of the present invention is a gas collection bag having a spout for injecting and / or discharging a sampled (collected) gas, and the bag body of the collection bag is as shown in FIG. The peripheral edge of the laminate 3 made only of the polyester resin in which the base film 1 made of the polyester resin and the sealant 2 made of the polyester resin are laminated is heat-sealed.

Examples of the polyester resin used for the base film 1 of the laminate 3 include polyethylene terephthalate (PET) and polyethylene-2,6-naphthalate (PEN). Two or more of these resins may be mixed or laminated. In particular, a stretched film obtained by laminating and stretching a high melting point resin and a low melting point resin, preferably the same or similar resin as that constituting the sealant 2 by coextrusion or the like, extrudes the sealant 2 into the low melting point resin layer. In the case of laminating by laminating or the like, it is preferable because high adhesive strength can be obtained and the laminate 3 having high sealing strength can be obtained.
The base film 1 is preferably a stretched film having excellent mechanical properties such as heat resistance and strength, and printability when printing on a collection bag. Specifically, biaxially stretched polyethylene terephthalate (O-PET). Mention may be made of stretched films of polyester resins such as films. In addition, when printing on a collection bag, when it prints on the back surface of the base film 1 and the sealant 2 is laminated | stacked, since it looks good and printing ink does not fall off, it is preferable. Of course, the base film 1 may be an unstretched film.
The thickness of the base film 1 depends on the use of the collection bag and the purpose of the inspection and is not particularly limited, but is usually about 10 μm to 50 μm, preferably 10 μm to 30 μm.

The sealant 2 can be used without particular limitation as long as it is a polyester resin that can be heat-sealed. Examples of the heat-bondable polyester resin include copolymer polyester resins such as isophthalic acid-modified polyethylene terephthalate, and polyester resins to which synthetic silica particles are added. These resins may be used as a mixture of two or more kinds or laminated by coextrusion or the like.
The thickness of the sealant 2 depends on the purpose of the collection bag and the purpose of the inspection and is not particularly limited, but is usually about 5 μm to 150 μm, preferably 15 μm to 80 μm.

The copolymer component of the copolyester resin that can be thermally fused may be a dicarboxylic acid component or a diol component. The copolyester resin can be obtained by using two or more of one or both of a dicarboxylic acid component and a diol component.
Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid, and cyclohexanedicarboxylic acid. An alicyclic dicarboxylic acid etc. can be illustrated.

The diol component includes aliphatic diols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol and diethylene glycol, alicyclic diols such as 1,4-cyclohexanedimethanol, and aromatics such as bisphenol A. Diol can be exemplified.
Of these copolymer components, isophthalic acid and / or 2,6-naphthalene dicarboxylic acid are used because of the ease of exhibiting various properties, the availability of raw materials, and the ease of production of copolymer polyesters. An acid is particularly preferably used.

  The polyester resin of the sealant 2 in the present invention is preferably isophthalic acid-modified polyethylene terephthalate. The isophthalic acid-modified polyethylene terephthalate resin in the present invention is a linear polyester resin obtained by condensation polymerization of a dicarboxylic acid component and a diol component. As the dicarboxylic acid component, terephthalic acid is the first main component and isophthalic acid is the first main component. 2 is a copolymer having ethylene glycol as a main component as a diol component. Here, the sum of the copolymerization ratios of terephthalic acid and isophthalic acid in the dicarboxylic acid component is preferably 95 mol% to 100 mol%, more preferably 99 mol% to 100 mol%. Moreover, 95 mol%-100 mol% are preferable and, as for the copolymerization ratio of ethylene glycol among diol components, 99 mol%-100 mol% are more preferable.

The copolymerization ratio of the isophthalic acid component in the isophthalic acid-modified polyethylene terephthalate resin constituting the sealant 2 is not particularly limited, but is, for example, 3 mol% to 30 mol%. Here, the copolymerization ratio of the isophthalic acid component is a mole percentage occupied by the isophthalic acid component in the dicarboxylic acid component.
The isophthalic acid-modified polyethylene terephthalate resin can be extruded and laminated using a normal single screw extruder and a T-die used for extrusion lamination of polyolefin resins. Therefore, as will be described later, since the sealant 2 having good heat sealability (ease of heat fusion) can be easily laminated on the base film 1 stretched at a high magnification, the mechanical strength excellent in heat sealability. Can be produced economically.

As a method of forming such a laminate 3, an adhesive or an anchor agent layer is used from the viewpoint of preventing a solvent or the like used for the adhesive or anchor from entering the bag and affecting the gas to be inspected. A laminating method that can be laminated without intervening is preferable. Examples of such a lamination method include extrusion lamination, co-extrusion, thermal lamination (thermocompression bonding), and the like. Of these, extrusion lamination is preferred for the following reasons.
Extrusion laminating melts the resin used as the sealant 2, extrudes the molten film from the T-die onto the base film 1, and pinches the roll ("backup" while quenching the molten resin film together with the base film 1 with a cooling roll. Crimp with a roll. Thereby, the sealant which consists of a polyester-type resin can be laminated | stacked without interposing an adhesive agent or an anchor agent layer. Extrusion lamination is economical because the rapid cooling and solidification of the sealant 2 and the lamination onto the base film 1 can be performed at the same time. In addition, since the sealant 2 is immediately laminated with the base film 1, the sealant 2 is formed in a substantially unstretched state and can maintain a low degree of crystallinity. Can be easily laminated.

  On the other hand, co-extrusion uses a ring die or T-die to extrude a plurality of resins in a molten state and form them into a film. Therefore, normally, the laminate 3 is unstretched, and both the base film 1 and the sealant 2 are unstretched. However, in order to improve mechanical strength and heat sealability, the laminate 3 is stretched. Also good. However, if the film is stretched at a very high magnification, the heat sealability of the sealant 2 may deteriorate. In addition, since the tube-shaped laminated body 3 is obtained when a ring die is used, it can be set as a bag main body only by heat-sealing two upper and lower sides. When a T die is used, the extruded resin can be rapidly cooled and solidified in the same manner as the extrusion lamination. When both the base film 1 and the sealant 2 are unstretched, if the melting point of the resin constituting the base film 1 is higher than the melting point of the resin constituting the sealant 2, the laminate 3 is heated with a hot plate seal. Since it becomes easy to weld, it is preferable.

  Since the laminate 3 in which the base film 1 and the sealant 2 are laminated is excellent in both heat sealability and processability, it is suitable for bag making using a normal bag making machine. Heat fusion for forming the bag body of the collection bag is a method of heat-sealing by heating the laminate 3 while applying pressure, such as an impulse seal or a hot plate seal, in order to stably obtain a sufficient seal strength. Is preferred. In particular, the hot plate seal is advantageous when bags are made at high speed using a bag making machine or the like. In the case of a gas collection bag, the contents to be accommodated are extremely light, and it is sufficient that the seal strength at the heat-sealed portion is about 1.5 kgf / 15 mm. The seal width may be 3 mm or more, and 5 to 10 mm is preferable in view of safety. In the case of the conventional fusing seal, the sealing strength is high, but the strength is likely to vary (3 to 7 kgf / 15 mm), and since only a small width of the cut edge of the film can be fused, the sealing width is large. Since it is as narrow as about 1 mm and is not stable, there is a problem that it is damaged by impact or catching. Compared with this, in the collection bag of this invention, the damage | damage by an impact, a catch, etc. can be avoided by ensuring sufficient seal width around a gas storage part. And even when the heat sealing | fusion part around a gas storage part is arrange | positioned at the periphery of a bag main body, breakage | damage of a heat sealing | fusion part and gas leakage can be prevented. Further, bag making using a normal bag making machine is possible, and the manufacturing cost can be reduced.

  The shape of the bag body is not particularly limited and is arbitrary, but normally, as shown in FIG. 2, a four-sided bag in which heat-sealed portions 11 are formed on the four sides of the periphery of the bag body 10, as shown in FIG. As in the second embodiment, a three-sided bag in which one of the peripheral edges of the bag main body 10A is the folded portion 18 and the heat-sealing portion 11 is formed on three sides, the third embodiment and the fourth embodiment shown in FIGS. As described above, a gusset bag having a gusset folding film 10a on both sides of the bag body 10B and the bag body 10C, or a standing pouch having a gusset folding film on the bottom portion can be used. In the case of a gusset bag, the volume can be reduced when the bag is empty, and since it is almost square (hexahedral) when the storage portion 12 is inflated with gas, it can be easily stored in a rectangular container such as a box. When a large number are placed side by side without being stored in a container, the posture of the collection bag is highly stable, which is preferable.

According to the present invention, since the heat-welded portion can be formed also inside the bag body away from the edge of the film, the corner 13 of the bag body is stored in the gas via the heat-fused portion 14. A hole 15 is provided in the corner 13 so as to pass a string, a rod, a ring, or the like. As a result, as shown in FIG. 3, it is possible to carry a plurality of collection bags by string 20 or the like, and the collection bags can be easily carried. In particular, the collection bag after gas collection is not easy to have a large number because the storage portion 12 is inflated, but the collection bag can be easily transported by passing the hole 15 through the string 20 or the like. . In addition, when a large number of collection bags are passed and packed in a box or cardboard for transportation, a stick is passed in the box, and the collection bag is hung by a hole 15 in the stick. This is preferable because breakage of the bag body and the spout 16 due to contact can be prevented. In this case, it is preferable that the holes 15 are provided on both sides of the upper and / or lower portions of the bag body and are horizontally suspended by two bars. On the other hand, the conventional collection bag with a fusing seal cannot form a hole for stringing, so it is necessary to devise such as carrying it in another bag or box larger than the collection bag, which is inconvenient. Met.
In addition, although the example which connected two collection bags is shown in FIG. 3, about 3-5 pieces or more connection is also possible.

  You may form the heat-fusion part 14 which divides the corner part 13 with respect to the some corner part 13. As shown in FIG. Moreover, the hole 15 may be provided in all the corner parts 13 in which the heat-fusion part 14 was formed, and the hole 15 may be provided only in a part.

  Since the corner portion 13 is separated from the gas storage portion 12, the hole 15 may be a simple through-hole, but it is preferable to form a heat-sealed portion 15a at the periphery of the hole 15 for reinforcement. Thereby, even if the string 20 or the like that has passed through the hole 15 rubs around the periphery of the hole 15, damage to the periphery of the hole 15 can be prevented. In this case, as long as the heat fusion part 15a of the periphery of the hole 15 is formed airtight, the heat fusion part 14 which divides the corner part 13 may be omitted.

  The spout 16 is used for injecting and discharging the sampled gas. Conventionally, using a spout having a divided bonding base, a hole is provided in the film constituting the bag body, and the hole and the surrounding film are sandwiched between the divided bonding bases. The method of integrating and attaching by fitting and screwing through the hole was employ | adopted. This method has a problem that the airtightness around the spout is unstable, the mounting operation is troublesome, and the mounting strength is low. In this invention, although this method can also be employ | adopted, the spout 16 can also be attached by heat-seal | fusing and joining with the sealant 2 of the laminated body 3 which comprises a bag main body. The attachment method by heat fusion is preferable because there is no problem of the conventional method, and since the sealing performance as a collection bag can be easily secured, it can be suitably used. Specifically, the spout 16 and the laminate are formed by using the spout 16 made of a resin that can be heat-sealed with the sealant 2 of the laminate 3, in which the whole spout 16 or at least a part (at least the bonding base portion 17). 3 are joined by thermal fusion. For this joining, if a spout formed of a polyester resin, preferably the same or similar to the resin constituting the sealant 2, is used as the spout 16, the sealant 2 of the laminate 3 can be easily and It is possible to heat-bond firmly. In addition, it is preferable to use a spout formed entirely of a polyester-based resin because the spout 16 is excellent in non-adsorption and gas barrier properties.

When the spout 16 is heat-sealed with the laminate 3, the spout (more specifically, a bonding base) may be inserted into the gap where the laminate 3 is overlapped with the sealant 2 inside, and heat-sealed. In this case, it is preferable to use a spout 16 having a boat-shaped joining base portion 17 as shown in FIG.
Alternatively, as shown in FIG. 6B, the cylindrical portion of the spout 16A is inserted through the hole formed in the laminate 3 from the inside to the outside, and the flange-like joining base portion 17A is formed on the sealant 2 inside the bag body. It is heat-sealed. In this case, as shown in FIG. 6B, it is desirable to use a spout 16A having a flange-shaped joining base portion 17A. Heat sealing in this manner is preferable because the spout 16A can be attached to any position of the bag body.

According to the collection bag of the present embodiment, the heat-welded portion having a predetermined width can be formed by a hot plate seal, an impulse seal or the like, and can be manufactured while suppressing variation in strength.
In addition, since the heat-welded part can be formed on the inner side of the bag body away from the edge of the film, the corner of the bag body is separated from the gas storage part via the heat-welded part. Since a hole for passing a string, a ring, or the like can be provided in the portion, the collection bag can be easily transported.

  INDUSTRIAL APPLICABILITY The present invention can be used as a collection bag used for collecting a gas during inspection of a volatile organic compound (VOC) or the like.

It is sectional drawing which shows an example of the laminated body which comprises the bag main body of the collection bag which concerns on this invention. It is a top view which shows the 1st form example of the collection bag which concerns on this invention. It is explanatory drawing which shows the state which connected the several collection bag shown in FIG. 2 with the string. It is a top view which shows the 2nd example of a collection bag which concerns on this invention. It is drawing which shows the 3rd form example of the collection bag which concerns on this invention, (a) is a top view, (b) is a perspective view. It is drawing which shows the 4th example of a collection bag which concerns on this invention, (a) is a top view, (b) is a perspective view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base film, 2 ... Sealant, 3 ... Laminated body, 1010A, 10B, 10C ... Bag main body, 11 ... Thermal fusion part of a periphery, 12 ... Storage part, 13 ... Corner part, 14 ... Corner part The heat fusion part to classify, 15 ... hole, 15a ... heat fusion part around a hole, 16, 16A ... spout, 17, 17A ... joining base part.

Claims (7)

  A gas collection bag having a spout for injecting and / or discharging sampled gas, the bag body of the collection bag is a laminate of a base film made of polyester resin and a sealant made of polyester resin A collection bag, which is obtained by heat-sealing a laminated body made only of a polyester resin.   The collection bag according to claim 1, wherein the laminate is a biaxially stretched polyethylene terephthalate film obtained by extrusion laminating a sealant made of a polyester resin without an anchor agent layer interposed therebetween.   The collection bag according to claim 2, wherein the polyester resin of the sealant is isophthalic acid-modified polyethylene terephthalate.   At least one corner of the bag main body is provided with a heat fusion part that separates a corner from a storage part of the bag main body, and a hole is provided at a corner divided by the heat fusion part. The collection bag according to any one of claims 1 to 3.   The collection bag according to claim 4, wherein a peripheral edge of the hole is heat-sealed.   The joining base part joined to at least the bag body of the spout is made of polyethylene terephthalate, and the joining base part is heat-sealed with the sealant of the bag body. The collection bag described.   The collection bag according to claim 1, wherein the bag body is a gusset bag.

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