JP7270179B2 - Multi-chamber container - Google Patents

Description

The present invention relates to a multi-chamber container made of plastic film.

Conventionally, many containers are known which are made of a plastic film and partitioned into a plurality of storage chambers by an easy peel seal (EPS) (Patent Documents 1 to 4).

For example, Patent Document 1 discloses a two-chamber bag composed of a three-layered plastic film consisting of an outer layer, a core layer and a sealant layer. The sealant layer comprises from about 45% to about 54% polypropylene (PP), from about 18% to about 27% styrene-ethylene-butylene-styrene copolymer (SEBS), and from about 9% to about 14% ethylene vinyl acetate copolymer. polymer (EVA), about 4.5 to about 9% paraffin oil, about 9.8% linear low density polyethylene (LLDPE), and about 2% ABPP.

Japanese Patent No. 3786604 Japanese Patent No. 3609415 Japanese Patent No. 4091685 Japanese Patent Publication No. 2008-508000

As described above, many multi-chamber containers partitioned by easily peelable seals have been proposed so far, but the technology for stably forming easily peelable seals while ensuring excellent mechanical strength has not yet been established. It has not been. For example, the easily peelable seal portion preferably has a seal strength in the range of 5 N/15 mm to 15 N/15 mm. Therefore, it was difficult to form an easily peelable seal portion with high accuracy.

An object of the present invention is to provide a multi-chamber container capable of stably forming an easily peelable seal portion while ensuring excellent mechanical strength.

A multi-chamber container according to one aspect of the present invention includes: a container body having an accommodating portion between plastic films facing each other; and an easily peelable seal part that is unsealed by an increase in pressure in the storage part, and the plastic film has a seal layer containing three types of polypropylene resins forming at least the innermost surface The three polypropylene resins are a low melting point random copolymer (random A1) having a melting point of 110°C to 135°C and a high melting point random copolymer (random B1 ) and a polypropylene homopolymer (PP homo), the content of the low melting point random copolymer (random A1) is 26 to 56 parts by mass with respect to 100 parts by mass of the sealing layer, and the high melting point The content of the random copolymer (random B1) is 10 to 30 parts by mass, and the content of the polypropylene homopolymer (PP homo) is 6 to 14 parts by mass.

In the multi-chamber container of the present invention, the plastic film may have a sealing strength of 2.5N/15mm to 20N/15mm at a sealing temperature of 120°C to 130°C.

In the multi-chamber container of the present invention, the sealing layer may further contain a thermoplastic elastomer (E).

In the multi-chamber container of the present invention, the thermoplastic elastomer (E) may contain a styrene-based elastomer.

According to the multi-chamber container of the present invention, a low melting point random copolymer (random A1) having a melting point of 110° C. to 135° C. and a high melting point random copolymer (random B1) having a melting point of 140° C. to 155° C. and polypropylene homopolymer (PP homo) are combined in a predetermined mass ratio to form the seal layer of the container body, thereby ensuring excellent mechanical strength and stably forming an easily peelable seal portion. Multi-chamber containers can be provided. As for the easily peelable seal portion, it is possible to achieve a seal strength of 2.5 N/15 mm to 20 N/15 mm, which is preferable for the easily peelable seal portion, over the entire sealing temperature range of 120°C to 130°C. Therefore, it is possible to provide a multi-chamber container that can be used for high-temperature sterilization at, for example, 121° C. or higher.

FIG. 1 is a schematic configuration diagram of a multi-chamber bag according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the multi-chamber bag taken along line II--II in FIG. FIG. 3 is a cross-sectional view of the multi-chamber bag taken along line III--III in FIG. FIG. 4 is a schematic configuration diagram of a multi-chamber bag according to another embodiment of the present invention. 5 is a cross-sectional view of the multi-chamber bag taken along line VV of FIG. 4. FIG. FIG. 6 is a schematic configuration diagram of a multi-chamber bag according to still another embodiment of the present invention. 7 is a schematic configuration diagram of a plastic film used in the multi-chamber bag of FIG. 6. FIG. FIG. 8 is a graph showing the relationship between the sealing temperature of the plastic film and the sealing strength. FIG. 9 is a graph showing the relationship between the sealing temperature of the plastic film and the sealing strength. FIG. 10 is a graph showing the relationship between the sealing temperature of the plastic film and the sealing strength.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a multi-chamber bag 1 according to one embodiment of the present invention. 2 and 3 are cross-sectional views of the multi-chamber bag 1 taken along line II-II and line III-III in FIG. 1, respectively.

A multi-chamber bag 1 as an example of a multi-chamber container of the present invention includes a bag body 3 having a storage section 2 defined therein, and a pouring member 4 for pouring medicine from the bag body 3 .

The bag body 3 is formed by bonding a pair of plastic films 5, 5 facing each other. In this embodiment, the bag body 3 is formed in a flattened rectangular (rectangular) bag shape. The length L of the bag body 3 is, for example, 150-350 mm, and the width W is, for example, 100-250 mm.

The pair of plastic films 5, 5 are adhered to each other by heat-sealing the entire peripheries. The heat-sealed portion of the periphery of the plastic films 5, 5 is the seal portion 6 that partitions the accommodating portion 2 between the plastic films 5, 5. As shown in FIG.

The annular seal portion 6 integrally includes a pair of vertical seals 7 that seal the opposing long sides of the housing portion 2 and a pair of horizontal seals 8 that seal the opposing short sides of the housing portion 2 . The pair of vertical seals 7 both have the same constant width and extend vertically in parallel in a straight line. The pair of horizontal seals 8 includes a head-side seal 81 that seals the short side on which the pouring member 4 is arranged, and a bottom-side seal that seals the short side (bottom side) opposite to the head side of the housing portion 2 . 82.

The head-side seal 81 extends laterally with a wider seal width than the vertical seal 7, and the pouring member 4 is fixed at the center in the length direction. The head-side seal 81 is provided with one non-sealed portion 9, 9 not heat-sealed on both sides in the lateral direction with the pouring member 4 interposed therebetween.

The bottom-side seal 82 extends laterally in parallel with the head-side seal 81 with a seal width wider than that of the vertical seal 7, and a suspension hole 10 is formed in the center in the length direction. The bottom-side seal 82 is provided with one non-sealed portion 11, 11 not heat-sealed on both lateral sides of the suspension hole 10. - 特許庁

The pouring member 4 is made of, for example, plastic such as polypropylene or polyethylene. When the bag main body 3 is manufactured, the pouring member 4 is sandwiched between the pair of plastic films 5, 5 and heat-sealed so that the pouring member 4 is tightly attached to the plastic films 5, 5 and fixed to the bag main body 3. be.

The pair of plastic films 5, 5 are further adhered to each other by an easily peelable seal portion 12 that partitions the storage portion 2 into a plurality of storage chambers. In FIG. 1 , an easily peelable seal portion 12 having one end and the other end connected to the seal portion 6 traverses the accommodating portion 2 , and the accommodating portion 2 is partitioned into two accommodating chambers 13 and 14 . The containing chambers 13 and 14 contain various medicines a and b, which are undesirable if mixed or dissolved in advance, respectively. For example, an amino acid solution and a glucose solution can each be contained. A solid or powdered drug can also be stored in one storage chamber 14 .

Here, the difference between the easily peelable seal portion 12 and the seal portion 6 is the magnitude of the heat seal strength. For example, the easily peelable seal portion 12 is pressed against at least one of the two storage chambers 13 and 14, and the pressure inside the storage chambers 13 and 14 increases and reaches a predetermined pressure. It has sealing strength. On the other hand, the sealed portion 6 has a heat seal strength to the extent that it will not be unsealed due to the increased pressure. More specifically, the easily peelable seal portion 12 has a heat seal strength of 2.5 N/15 mm to 15 N/15 mm as a heat seal strength measured according to JIS-Z-0238. Thus, the seal portion 6 has a heat seal strength of 30 N/15 mm to 75 N/15 mm.

Then, the easily peelable seal part 12 and the seal part 6 are heat-sealed to the common plastic films 5, 5 under different conditions (temperature, pressure, time, etc.), so that the same multi-chamber bag 1 can be attached. can coexist.

For example, the conditions for thermocompression bonding of the easily peelable seal portion 12 are, when using a multilayer plastic film 5 having a total thickness of 180 to 320 μm, the mold temperature is 120° C. to 130° C., the pressure (air pressure) is 2 kgf to 6 kgf, The pressurization time may be 1.5 seconds to 5.5 seconds. On the other hand, the conditions for thermocompression bonding of the seal portion 6 are as follows: when using the multilayer plastic film 5 with a total thickness of 180 to 320 μm, the mold temperature is 135° C. to 155° C., the pressure (air pressure) is 2 kgf to 6 kgf, and the pressure is applied. The time may be 1.5 seconds to 5.5 seconds.

As shown in FIGS. 2 and 3, the plastic film 5 forming the bag body 3 has a three-layered structure (multilayer film) consisting of an inner layer 51, an outer layer 53 and an intermediate layer 52 therebetween. Note that the three-layer film shown in FIGS. 2 and 3 is just an example of the plastic film 5 . The plastic film 5 may be, for example, a two-layer film consisting of only the inner layer 51 and the outer layer 53, or a multi-layer film consisting of four or more layers.

The thickness of each layer 51 to 53 may be, for example, 20 μm to 60 μm for the inner layer 51, 145 μm to 220 μm for the intermediate layer 52, and 15 μm to 40 μm for the outer layer 53. The thickness of the entire plastic film 5 may be, for example, 180 μm to 320 μm. By setting the thickness of the entire plastic film 5 to 180 μm or more, it is possible to achieve strength sufficient to withstand the weight of the contents of the bag. Further, by setting the thickness of the entire plastic film 5 to 320 μm or less, the film can be given sufficient flexibility.

Resins constituting the intermediate layer 52 and the outer layer 53 are not particularly limited, and known resins can be applied. For example, polyolefin resins such as polyethylene, polypropylene, poly(4-methylpentene) and polytetrafluoroethylene, polycyclic olefin resins such as ethylene-tetracyclododecene copolymer, and polyester resins such as polyethylene terephthalate (PET) Resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), vinyl polymer resin such as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, nylon-6, nylon-12, General-purpose resins such as polyamide-based resins such as nylon-6,6 can be used. These may be used alone or in combination of two or more.

The inner layer 51 contains a plurality of polypropylene resins. The plurality of polypropylene resins are at least a low melting point random copolymer (random A1) having a melting point of 110 ° C. to 135 ° C. and a high melting point random copolymer (random B1) having a melting point of 140 ° C. to 155 ° C. , polypropylene homopolymer (PP homo).

Examples of comonomers other than propylene in the low melting point random copolymer (random A1) and the high melting point random copolymer (random B1) include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1 α-olefins such as -pentene, 1-octene and 1-decene, preferably ethylene. The low melting point random copolymer (random A1) can be obtained by copolymerizing a propylene monomer and a comonomer other than propylene (preferably ethylene) under predetermined conditions in the presence of a metallocene catalyst. can.

Further, the melting point of the polypropylene homopolymer (PP homo) is preferably 155°C to 170°C.

Moreover, in the inner layer 51, the preferred content ratios of the low melting point random copolymer (random A1), the high melting point random copolymer (random B1) and the polypropylene homopolymer (PP homopolymer) are as follows.

For example, the content of the low-melting-point random copolymer (random A1) is 26 to 56 parts by mass, preferably 26 to 54 parts by mass, with respect to 100 parts by mass of the resin forming the inner layer 51. It is preferably 31 to 44 parts by mass, particularly preferably 35 to 42.5 parts by mass. The content of the high melting point random copolymer (random B1) is 10 to 30 parts by mass, preferably 15 to 30 parts by mass, with respect to 100 parts by mass of the resin constituting the inner layer 51. Preferably, it is 20 to 28 parts by mass. The content of the polypropylene homopolymer (PP homo) is 6 to 14 parts by mass, preferably 7.5 to 12.5 parts by mass, with respect to 100 parts by mass of the resin forming the inner layer 51 . Among these ranges, the most preferable combination is 35 to 42.5 parts by mass of the low melting point random copolymer (random A1) and the high melting point random copolymer ( A combination of 20 to 28 parts by weight of random B1) and 7.5 to 12.5 parts by weight of polypropylene homopolymer (PP homo).

The total amount of the low melting point random copolymer (random A1), the high melting point random copolymer (random B1) and the polypropylene homopolymer (PP homo) is 60 to 60 parts by mass with respect to 100 parts by mass of the resin forming the inner layer 51. It is preferably contained in a proportion of 100 parts by mass, more preferably in a proportion of 60 to 80 parts by mass.

In addition, as another mode for achieving the aforementioned object of the present invention, the plurality of polypropylene resins of the inner layer 51 does not contain the high melting point random copolymer (B1) and has a low melting point random copolymer having a melting point of 110° C. to 135° C. It may consist of two kinds of polypropylene resins, a copolymer (random A1) and a polypropylene homopolymer (PP homo).

In this case, the content of the low melting point random copolymer (random A1) is 42 to 58 parts by mass, preferably 45 to 55 parts by mass, with respect to 100 parts by mass of the resin forming the inner layer 51 . The content of the polypropylene homopolymer (PP homo) is 12 to 28 parts by mass, preferably 15 to 25 parts by mass, with respect to 100 parts by mass of the resin forming the inner layer 51 . Among these ranges, the most preferable combination is 45 to 55 parts by mass of the low melting random copolymer (random A1) and 45 to 55 parts by mass of the low melting point random copolymer (random A1) and the polypropylene homopolymer (PP homo) with respect to 100 parts by mass of the resin constituting the inner layer 51. It is a combination of 15 to 25 parts by mass.

Moreover, the inner layer 51 may contain a thermoplastic elastomer (E) in addition to a plurality of polypropylene resins.

The thermoplastic elastomer (E) contained in the inner layer 51 may be, for example, various thermoplastic elastomers such as styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, and ester-based elastomers. These can be used singly or in combination of two or more. Among these, the inner layer 51 preferably contains a styrene-based elastomer. Since the styrene-based elastomer is highly compatible with the low-melting point random copolymer, the high-melting point random copolymer, and the polypropylene homopolymer, it is possible to suppress the occurrence of interfacial separation and deterioration of transparency. The content of the thermoplastic elastomer (E) is, for example, 10 to 50 parts by mass, preferably 12 to 48 parts by mass, more preferably 100 parts by mass of the resin constituting the inner layer 51. , 17 to 37.5 parts by mass. Most preferably, 35 to 42.5 parts by mass of the low melting point random copolymer (random A1) and 35 to 42.5 parts by mass of the high melting point random copolymer (random B1) are added to 100 parts by mass of the resin constituting the inner layer 51. 20 to 28 parts by mass, 7.5 to 12.5 parts by mass of polypropylene homopolymer (PP homo), and 17 to 37.5 parts by mass of styrene elastomer.

In order to manufacture the multi-chamber bag 1, for example, two plastic films 5 are superimposed so that the inner layers 51 face each other.

Next, the two superimposed plastic films 5 are sandwiched between molds, and the molds are heated in the sandwiched state. The mold temperature at this time is as described above. As a result, the plastic film 5 is simultaneously provided with the sealing portions 6 of the multiple-chamber bags 1 .

Next, the easily peelable seal portion 12 is formed by welding the central portion of each multi-chamber bag 1 .

Next, by cutting unnecessary plastic film 5, individual multi-chamber bags 1 are punched out collectively. After that, the pouring member 4 is attached to each multi-chamber bag 1 by heat sealing. Thereby, the multi-chamber bag 1 of FIG. 1 is obtained.

As described above, according to the multi-chamber bag 1, a low melting point random copolymer (random A1) having a melting point of 110 ° C. to 135 ° C. and a high melting point random copolymer (random B1) having a melting point of 140 ° C. to 155 ° C. and polypropylene homopolymer (PP homopolymer) in a predetermined mass ratio to form the inner layer 51 of the bag body 3, thereby ensuring excellent mechanical strength and stably forming the easily peelable seal portion 12. A multi-chamber bag 1 can be provided.

As for the easily peelable seal portion 12, it is possible to achieve a preferable seal strength of 2.5N/15mm to 20N/15mm for the easily peelable seal portion 12 over the entire sealing temperature range of 120°C to 130°C. Therefore, it is possible to provide the multi-chamber bag 1 that can be used for high-temperature sterilization at, for example, 121° C. or higher.

Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, it can be implemented as a multi-chamber bag 21 shown in FIGS. In the multi-chamber bag 21, the storage section 2 is partitioned in the vertical direction by forming the easily peelable seal section 12 along the pouring direction of the medicines a and b. Further, in place of the pouring member 4 of FIG. 1, a tubular pouring member 22 made of a flexible member such as ethylene-vinyl acetate copolymer (EVA) is provided in each of the storage chambers 13 and 14. is provided.

Moreover, it can also be implemented as a multi-chamber bag 31 shown in FIG. In the multi-chamber bag 31, no seal portion is formed over the entire circumference of the storage portion 2, and the head-side seal 81 and the bottom-side seal 82 of the storage portion 2 are selectively formed. The long side of the accommodating portion 2 is formed as a folded line portion 71 in which overlapping plastic films are continuously connected. Accordingly, the housing portion 2 is partitioned by the fold line portion 71 and the seals 81 and 82 . Such a multi-chamber bag 31 is, for example, tubular as shown in FIG. 33 and the opening 34 on the other side can be obtained by heat sealing to form seals 81 and 82, respectively.

For example, the multi-chamber container of the present invention can be used for other uses such as a packaging container for food, in addition to the medical drug bag described above.

In addition, various design changes can be made within the scope of the matters described in the claims.

For example, from the content of the above-described embodiment, the plurality of polypropylene resins of the inner layer 51 are a low melting point random copolymer (random A1) having a melting point of 110° C. to 135° C. and a polypropylene homopolymer (PP homo). The following characteristics can be extracted as a form containing the seed polypropylene resin.

a container body having an accommodating portion between plastic films facing each other, and part or all of the accommodating portion being partitioned by a sealing portion;
and an easily peelable seal portion that partitions the storage portion into a plurality of storage chambers and is opened by an increase in pressure in the storage portion,
The plastic film has a sealing layer containing two polypropylene resins forming at least the innermost surface,
The two polypropylene resins include a low melting point random copolymer (random A1) having a melting point of 110° C. to 135° C. and a polypropylene homopolymer (PP homo),
For 100 parts by mass of the seal layer,
The content of the low melting point random copolymer (random A1) is 42 to 58 parts by mass,
A multi-chamber container containing 12 to 28 parts by mass of the polypropylene homopolymer (PP homopolymer).

According to this multi-chamber container, a low melting point random copolymer (random A1) having a melting point of 110° C. to 135° C. and a polypropylene homopolymer (PP homopolymer) are combined in a predetermined mass ratio to seal the container body. By forming a layer, it is possible to provide a multi-chamber container in which an easily peelable seal portion can be stably formed while ensuring excellent mechanical strength. As for the easily peelable seal portion, it is possible to achieve a seal strength of 2.5 N/15 mm to 20 N/15 mm, which is preferable for the easily peelable seal portion, over the entire sealing temperature range of 120°C to 130°C.

This application corresponds to Japanese Patent Application No. 2016-013630 filed with the Japan Patent Office on January 27, 2016, and the entire disclosure of this application is incorporated herein by reference.

EXAMPLES Next, the present invention will be described based on examples, comparative examples and reference examples, but the present invention is not limited to the following examples.
(1) Production of multilayer film In each example, each comparative example, and each reference example, the inner layer 51, the intermediate layer 52, and the outer layer were melt-mixed based on the blending ratios (parts by mass) shown in Tables 1 to 3 below. 53 were prepared. Then, these resin materials were subjected to water-cooling co-extrusion inflation molding to prepare a three-layer film having the layer structure shown in Tables 1 to 3 below. The information on the resin materials shown in Tables 1 to 3 is as follows.
<Random copolymer A>
・ Random A1 (ethylene-propylene random copolymer)
(Melting point 127°C MFR: 7.0 manufactured by Japan Polypropylene Corporation)
<Random copolymer B>
・ Random B1 (ethylene-propylene random copolymer)
(Melting point 147° C. MFR: 1.8 manufactured by Lee Chang Young Chemical Industry Co., Ltd.)
・Random B2 (ethylene-propylene random copolymer)
(Melting point 137°C MFR: 1.5 manufactured by Basel)
<Propylene Homopolymer>
・ PP homo (melting point 166°C, manufactured by Lee Chang Young Chemical Industry Co., Ltd.)
<Thermoplastic elastomer E>
・ Styrene-based E1 (manufactured by Kraton)
・ Styrene-based E2 (manufactured by Kraton)
・ Olefin-based E1 (manufactured by Mitsui Chemicals, Inc.)
<PP compound-1>
・ Random B2 / styrene E1 = 90: 10 (blending ratio)
<PP compound-2>
・PP homo/random B1/olefin-based E1/styrene-based E1 = 20:40:30:10 (blending ratio)
(2) Evaluation test (a) Pressure resistance test Each film obtained in Examples, Comparative Examples, and Reference Examples was cut into squares of 14 cm on each side, four sides were heat-sealed at a predetermined temperature, and a chemical solution was filled inside. Samples were prepared by sterilizing at 121° C. for 15 minutes at room temperature. Each sample was set in a 17 mm gap provided in a pressure tester at room temperature. After setting, air was injected into the sample to raise the internal pressure to 200 kPa, and it was confirmed whether the sample burst within 15 minutes. The results are shown in Tables 1 to 3 below. In Table 1, "O" indicates that the sample did not burst, and "X" indicates that the sample burst.
(a) Seal curve Next, each film obtained in Examples, Comparative Examples, and Reference Examples has a seal temperature of 2.5 N/15 mm to 20 N/preferably as an easily peelable seal portion over the entire sealing temperature range of 120 ° C. to 130 ° C. The ability to achieve a seal strength of 15 mm was evaluated by creating a seal curve for each film.

More specifically, a pair of each of the films obtained in Examples, Comparative Examples and Reference Examples is prepared, a heat sealer is used, and the direction of the seal bar is the TD direction (transverse direction) of the film. (so that it can be peeled in the MD direction (film flow direction) in the peel test described later). The heat sealing conditions at this time are as follows.
・Temperature: 5°C increments from 100°C to 160°C ・Pressure: 4.0 kgf with air pressure
・Pressure time: 2.5 seconds ・Seal bar size: width x length = 20 mm x 190 mm
Then, five strips each having a width of 15±0.1 mm were cut out perpendicularly from the heat-sealed portion at each temperature, and these strips were used as samples. After that, the sample was left in an environment of 23±2° C. and 50±5% RH for 4 hours or more.

Next, each sample was subjected to a peel test. In the peel test, first, a sample was taken, opened at an angle of 180° around the heat-sealed portion, and both ends of the sample were placed on jigs of a tensile tester (distance between jigs: 50 mm). Next, a peeling test was performed at a head speed of 300±20 mm/min, and the maximum load at that time was recorded as the seal strength (breakage was recorded in the case of breakage). Then, based on the obtained peel test data, the horizontal axis was set to the sealing temperature and the vertical axis was set to the sealing strength (peel strength), and a sealing curve was graphed. The graphs are shown in FIGS. 8 to 10. FIG. Tables 1 to 3 show the seal strength (N/15 mm) at seal temperatures of 120°C and 130°C.
(C) Evaluation results First, as shown in Tables 1 and 2, Examples 1 to 3 and From the results of Reference Examples 1 to 3, it was found that excellent mechanical strength (pressure resistance) can be ensured by containing each polypropylene resin in the ratio specified in the above embodiment.

Furthermore, referring to FIGS. 8 and 9, the sealing curves of Examples 1 to 3 and Reference Examples 1 to 3 have a gentle slope over the entire sealing temperature range of 120° C. to 130° C. 1 and Table 2, it was possible to achieve a seal strength of 2.5 N/15 mm to 20 N/15 mm, which is preferable for an easily peelable seal portion.

On the other hand, even if the inner layer 51 is made of the same polypropylene resin as in Examples 1 to 3 and Reference Examples 1 to 3, if the amount of polypropylene homopolymer (PP homo) is small as in Comparative Examples 1 and 3, mechanical Although the strength can be secured, the slope of the sealing curve becomes steep from the sealing temperature range of 120 ° C. or less, and the heat-sealed part sealed in the sealing temperature range of 120 ° C. to 130 ° C. can no longer be said to be an easily peelable seal part. The higher the seal strength, the higher the seal strength.

In addition, when the inner layer 51 contains a large amount of polypropylene homopolymer (PP homopolymer) as in Comparative Examples 2 and 4, not only is the mechanical strength low, but the slope of the sealing curve is gentle in the sealing temperature range of 120 ° C. to 130 ° C. However, it was found that the seal strength was too low. With such a sealing strength, even if the plastic film is used to form a multi-chamber bag, the easily peelable seal portion may be opened by a small pressure, which is not practically preferable.

8 and 9, the sealing curves of Example 1 and Reference Example 1, the sealing curves of Example 2 and Reference Example 2, and the sealing curves of Example 3 and Reference Example 3 are It can be seen that they each draw the same curve.

This indicates that there is more than one composition of the plastic film showing a sealing curve that satisfies the sealing strength of 2.5N/15mm to 20N/15mm in the sealing temperature range of 120°C to 130°C. A condition that at least a low melting point random copolymer (random A1) having a melting point and/or a high melting point random copolymer (random B1) having a melting point of 140° C. to 155° C. and a polypropylene homopolymer (PP homo) are included. It shows that there are any number of ways if .

Table 3 and FIG. 10 are results to supplement the above facts. That is, although Examples 4 and 5, Reference Example 4 and Comparative Example 5 differ in the number of types of polypropylene resins used and their blending ratios, they all draw the same curve. I understand.

From the above, in the above-described embodiments, the low melting point random copolymer (random A1) having a melting point of 110° C. to 135° C. and/or the high melting point random copolymer (random A1) having a melting point of 140° C. to 155° C. It can be said that it is possible to make various design changes so as to obtain the desired mechanical strength and sealing curve under the condition that it contains at least B1) and polypropylene homopolymer (PP homo).

REFERENCE SIGNS LIST 1 multi-chamber bag 2 storage part 3 bag body 5 plastic film 6 sealing part 12 easily peelable seal part 13 storage chamber 14 storage chamber 21 multi-chamber bag 31 multi-chamber bag 32 plastic film 51 inner layer

Claims (2)

a container body having an accommodating portion between plastic films facing each other, and part or all of the accommodating portion being partitioned by a sealing portion;
and an easily peelable seal portion that partitions the storage portion into a plurality of storage chambers and is opened by an increase in pressure in the storage portion,
The plastic film has a seal layer containing three polypropylene resins forming at least the innermost surface,
The three types of polypropylene resins are a low melting point random copolymer (random A1) having a melting point of 110° C. to 135° C., a high melting point random copolymer (random B1) having a melting point of 140° C. to 155° C., including polypropylene homopolymer (PP homo),
For 100 parts by mass of the seal layer,
The content of the low melting point random copolymer (random A1) is 26 to 54 parts by mass,
The content of the high melting point random copolymer (random B1) is 10 to 30 parts by mass,
The content of the polypropylene homopolymer (PP homo) is 6 to 14 parts by mass,
The multi-chamber container, wherein the sealing layer contains 30 to 50 parts by mass of a styrene-based elastomer with respect to 100 parts by mass of the sealing layer. The multi-chamber container according to claim 1, wherein the plastic film has a sealing strength of 2.5N/15mm to 20N/15mm at a sealing temperature of 120°C to 130°C.

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