JPH06106660A - Inner container for bag-in box - Google Patents

Abstract

PURPOSE:To provide an inner container for a bag-in box generating no crack in a laminate punching process at the time of the formation of the liquid injection port of the inner container and excellent in gas barrier properties over a long time. CONSTITUTION:An intermediate layer is formed from a resin compsn. prepared by mixing 70-98wt.% of a saponified ethylene/vinyl acetate copolymer with ethylene content of 15-50mol% and a saponification degree of a vinyl acetate component of 95mol% or more with 30-2wt.% of a polyurethane elastomer substantially containing no free isocyanate group but containing 10-50wt.% of a urethane bond in its molecule and having melt viscosity of (1.0X10<2>)-(5X10<4>) poise at 200 deg.C at 18-250 deg.C in a molten state. Adhesive layers are provided to both surfaces of the intermediate layer and surface layers are further provided on the adhesive layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner container for a bag-in-box, and more particularly to an inner container for a bag-in-box which is excellent in punching workability of a liquid injection port and has a gas barrier property maintained for a long period of time. Is provided.

[0002]

2. Description of the Related Art Generally, a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) is excellent in transparency, antistatic property, oil resistance, solvent resistance, gas barrier property and aroma retention property. However, it is also a material having the drawback of low impact resistance, bending fatigue resistance, stretchability, thermoformability, gas barrier property during moisture absorption or water absorption. Therefore, in the intended use as a packaging material, by laminating films of low density polyethylene, polypropylene, nylon, polyester, etc. on both front and back sides of the EVOH film, gas barrier property, aroma retention property, and discoloration prevention property of foods. While maintaining the characteristics of EVOH such as the above, it is used for various packaging applications by compensating for the defects of EVOH such as drop strength, thermoformability, and moisture resistance.

In recent years, a bag-in-box has come to be used as a packaging container for transporting and storing liquids for drinks such as wine and juice and liquids such as photographic developing solutions. This bag-in-box is
A cardboard box contains a flexible plastic packaging container provided with a liquid inlet, which is widely used as a means for transporting various liquids, and the EVOH laminate described above is also used as the inner container of the bag-in-box. Has reached.

The required performance of the inner container at this time is as follows.
Since it is important to maintain excellent gas barrier properties even during extremely severe bending fatigue during transportation, various devices have been tried, and linear low density polyethylene layer / adhesive layer / EVOH layer / Adhesive / linear low-density polyethylene (hereinafter abbreviated as LLDPE) layer laminate (JP-A-60-161146), LLDPE layer / adhesive layer / EVOH layer / adhesive layer / ethylene-vinyl acetate Copolymer resin layer, biaxially oriented nylon layer, or biaxially oriented polypropylene laminate (JP-A-60-168649), surface layer / carboxylic acid modified LLDPE / EVOH
A layer / carboxylic acid-modified LLDPE / surface layer laminate (JP-A-60-242054) has been proposed.

[0005]

However, the laminated film having the EVOH as the intermediate layer as described above has improved flexural fatigue resistance, but has a high gas barrier that can withstand long-term storage and transportation. The sex is still insufficient. The reason for this is that in manufacturing the inner container, it is necessary to make a liquid injection port in the inner container, and a punching hole is formed in the laminated film. At this time, however, the EVOH layer is less flexible, and therefore the EVOH layer is less flexible. This is because cracks are generated in the cracks, and these cracks grow due to stress during transportation and the like, which eventually impairs the gas barrier property.

[0006]

[Means for Solving the Problems] Therefore, as a result of intensive studies to solve the above problems, the present inventors have found that the ethylene content is 15 to 50 mol% and the vinyl acetate component is saponified. 70 to 98% by weight of EVOH having a degree of 95 mol% or more, substantially no free isocyanate group in the molecule, and 10 to 50% by weight of the urethane bond represented by Chemical formula 1,

[Chemical 1] And the melt viscosity at a temperature of 200 ° C. is 1.0 × 10 ² to
5 × 10 ⁴ poise polyurethane elastomer 30 to 2
A resin composition (A) obtained by melting and mixing wt% at 180 to 250 ° C. was used as an intermediate layer, an adhesive layer was provided on both sides of the intermediate layer, and a surface layer was provided outside the adhesive layer. The present invention has been completed by finding that the inner container for bag-in-box can maintain a good gas barrier property even during transportation over a long period of time without cracking during the production of the liquid injection port. The present invention will be described in detail below.

The EVOH used in the present invention has an ethylene content of 15 to 50 mol%, preferably 25 to 48 mol%.
A vinyl acetate component having a saponification degree of 95 mol% or more, preferably 98 mol% or more is usually used. When the ethylene content is less than 15 mol%, the oxygen barrier property at high humidity is deteriorated, while when it exceeds 50 mol%, the physical properties such as oxygen barrier property are deteriorated. If the degree of saponification is less than 95 mol%, the oxygen barrier property and moisture resistance will be reduced. Among such EVOH, the intrinsic viscosity (measured as a 15% hydrous phenol solution at 30 ° C.) is 0.7 to 1.5 dl / g, preferably 0.8 to 1.3 d.
The thing of 1 / g is used suitably from the viewpoint of mechanical strength of the molded product.

The EVOH is a small amount of α-olefins such as propylene, isobutene, α-octene, α-dodecene and α-octadecene, and unsaturated carboxylic acid within a range that does not impair properties such as transparency and gas barrier property. Alternatively, it may include a comonomer such as a salt thereof, a partial alkyl ester, a complete alkyl ester, a nitrile, an amide, an anhydride, an unsaturated sulfonic acid or a salt thereof. Further, the polyurethane elastomer to be mixed with such EVOH contains substantially no free isocyanate group in the molecule, and contains 10 to 50% by weight of the urethane bond represented by Chemical formula 1,

[Chemical 1] And the melt viscosity at a temperature of 200 ° C. is 1.0 × 10 ² to
Limited to 5 × 10 ⁴ poise.

When a polyurethane elastomer containing a free isocyanate group is used, a flow mark,
Weld marks tend to be generated and impair the appearance of the molded product, and if the urethane bond ratio is less than 10%, EVO
The compatibility with H is poor, and on the other hand, when it exceeds 50%, the impact resistance is not sufficiently improved, which is not preferable. Further, if the melt viscosity is out of the above range, the compatibility with EVOH is poor and the effect of improving impact resistance cannot be expected. However, if the amount of free isocyanate group is about 1% or less, there is no difference in effect. The melt viscosity can be adjusted by adding a chain extender or changing the molecular weight of the polyol component. As the chain extender, glycol, diamine and the like are generally used, but 1,4-butylene glycol, P-xylene glycol and the like are preferable.

Such a polyurethane elastomer is
(A) A compound obtained by a normal urethane reaction between a polyisocyanate compound and (b) a polyol component,
As the polyisocyanate compound, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, Lysine diisocyanate, these modified diisocyanates, bifunctional isocyanates such as hydrogenated diisocyanates, and burette type polyisocyanate compounds obtained by reacting each diisocyanate compound with water, and further 2-isocyanatoethyl-
Examples thereof include trifunctional isocyanate compounds such as 2,6-diisocyanate hexanoate, and multimers obtained by converting each of the above-mentioned diisocyanate compounds into an isocyanurate, which may be used alone or in combination of two or more kinds. .

As the (b) polyol component, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol,
Tetraethylene glycol, dipropylene glycol,
1,4-butanediol, 1,6-hexanediol,
Neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, polycaprolactone, trimethylolethane, trimethylolpropane,
Polytrimethylolpropane, pentaerythritol,
Examples thereof include polypentaerythritol, sorbitol, mannitol, glycerin, polyglycerin and the like.
Further, as the polyester polyol, a hydroxyl value of 60 to 600 KOH is a reaction product of the above polyhydric alcohol and polybasic acid.
The one of mg / g is used.

Examples of polybasic acids include maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, phthalic anhydride, phthalic acid, terephthalic acid, isophthalic acid, het acid, adipic acid and tetrahydrophthalic anhydride. Used. Among such polyurethane elastomers, urethane urethane products of polyethers such as polyethylene glycol and polypropylene glycol, urethane products of adipic acid, azelaic acid and ethylene glycol, polyester polyols of alkylene oxide and the like can be preferably used practically.

The EVOH and the polyurethane elastomer are mixed in a ratio of 70:30 to 98: 2 by weight, and if the ratio of the polyurethane elastomer is too large, the hardness and rigidity of the molded article are lowered. So inappropriate. These two components are heated and melt-mixed at a temperature of 180 to 250 ° C., but the means thereof is not particularly limited, and any known melt-mix molding method using an ordinary extruder, injection molding machine or the like is adopted. To be done. Further, as the resin component of the intermediate layer of the present invention, the above EVOH
In addition to polyurethane elastomers, plasticizers (polyhydric alcohols, etc.), stabilizers, surfactants, crosslinkable substances (epoxy compounds, polyvalent metal salts, inorganic or organic polybasic acids or salts thereof, etc.), fillers, Fibers (glass fiber, carbon fiber, etc.) as a colorant and a reinforcing agent can be added in appropriate amounts.

Further, other thermoplastic resins may be blended in appropriate amounts, and such thermoplastic resins include polyolefins (low / medium / high density polyethylene, isotactic polypropylene, ethylene-propylene copolymer, ethylene-propylene). -Diene copolymer, ethylene and carbon number 4
The above copolymers with α-olefins, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, ionomers, polybutenes, polypentenes, etc.) or modified by graft modification of these with unsaturated carboxylic acids or their derivatives Examples thereof include polyolefins, polyamides such as nylon 6/66 copolymers, polyvinyl chloride, polyvinylidene chloride, polyesters, polystyrene, polyacrylonitrile, polyacetal, and melt-moldable polyvinyl alcohol resins.

The inner container for bag-in-box of the present invention is
At least a surface layer / adhesive layer / intermediate layer (A) / adhesive layer / surface layer consisting of a five-layer laminate having a density of 0.86 to 0.95 g / cm ³ (20 ° C.). The ethylene-α-olefin copolymer of is preferred. The density referred to here is a value measured by JIS K 6760 at 20 ° C. When the density is smaller than the above range,
The mechanical properties of the laminate will be insufficient, or blocking will occur. On the contrary, when it is large, the bending fatigue resistance is insufficient, which is not preferable. In addition, ethylene-α-olefin means ethylene and butene-1, pentene-1,4-
It is a copolymer having 18 or less carbon atoms such as methylpentene-1, hexene-1, and octene-1. Among these, an ethylene-α-olefin copolymer using an α-olefin having 4 to 8 carbon atoms is preferably used.

Further, as the adhesive resin used for the adhesive layer, a density of 0.86 to 0.95 g / cm ³ modified with an unsaturated carboxylic acid or an anhydride thereof (measurement conditions are those of the above surface layer). The same as the above case) ethylene-α-olefin copolymer is preferable and can be obtained by copolymerizing or graft-modifying the same resin as described in the above surface layer with an unsaturated carboxylic acid or an anhydride thereof. Of course, the modification also includes blending an unmodified ethylene-α-olefin copolymer with an unsaturated carboxylic acid or an anhydride thereof. As the unsaturated carboxylic acid or its anhydride, maleic acid,
Examples thereof include maleic anhydride, fumaric acid, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride and the like, among which maleic anhydride is preferably used.

At this time, the amount of the unsaturated carboxylic acid or its anhydride contained in the ethylene-α-olefin copolymer is preferably 0.01 to 10% by weight, more preferably 0.1 to 3% by weight. Is. If the content in the modified product is small, the adhesive strength with the intermediate layer and the surface layer will be reduced, and conversely, if it is large, a crosslinking reaction will occur and moldability will be poor, such being undesirable.
The thickness of each layer of the surface layer / adhesive layer / intermediate layer (A) / adhesive layer / surface layer laminate of the present invention is 10 to 10, respectively.
600μ / 2-50μ / 1-50μ / 2-50μ / 10
Selected from the range of ~ 600μ, preferably 30-2
00μ / 5-10μ / 5-30μ / 5-10μ / 30-
It is 200μ.

The greatest feature of the present invention is that the E specific to the intermediate layer is used.
Since the VOH / polyolefin resin melt-mixed composition is employed, the laminate of the present invention using EVOH for the intermediate layer has a surface layer / adhesive layer / intermediate layer (A) / adhesive layer / surface layer Not limited to the structure, a surface layer / adhesive layer / intermediate layer (A) / adhesive layer / surface layer / adhesive layer / surface layer, surface layer / adhesive layer / Surface layer /
It is also possible to form a laminate of 6 or more layers such as adhesive layer / intermediate layer (A) / adhesive layer / surface layer / adhesive layer / surface layer. Further, using a nylon layer, surface layer / adhesive layer / nylon layer / intermediate layer (A) / adhesive layer / surface layer, surface layer /
Adhesive layer / nylon layer / intermediate layer (A) / nylon layer / adhesive layer / surface layer, surface layer / adhesive layer / nylon layer / adhesive layer / intermediate layer (A) / adhesive layer / surface layer, etc. It is also possible to use a laminated body of Nylon 6, Nylon 6 / 6-6, Nylon 6 / 6-6,
Nylon 12, amorphous nylon, or blends thereof may be mentioned.

In the surface layer and the adhesive layer of the laminate of the present invention, antioxidants, slip agents, hydrotalcites, antistatic agents, plasticizers, colorants, etc. are added to improve moldability. Can be added within a range that does not impair the effects of the present invention. The inner container for bag-in-box of the present invention can be manufactured mainly by a heat sealing method and a blow molding method. In the heat-sealing method, the film for the intermediate layer and the surface layer formed by the inflation method or the flat film method is a laminated body obtained by dry laminating through the adhesive layer or a laminated body in which each layer is laminated by the coextrusion method or the like. As it is, or if necessary, double or triple layers are piled up, and a hole for attaching a sealing plug of the liquid injection port is punched out, and the sealing plug of the liquid injection port formed by injection molding in advance is heat-sealed into the hole. Fuse with. At that time, the laminated body and another laminated body which has not been punched out are combined and heat-sealed in four directions to form an inner container for bag-in-box. In the blow molding method, the above-mentioned cylindrical laminated body extruded from the extruder is clamped with a mold to form it. The sealing plug of the liquid injection port, which has been molded by injection molding in advance, is set in the mold and is fused with the molding container during blow molding. Then open the liquid inlet.

[0020]

The inner container for bag-in-box of the present invention is an EVO containing a specific polyurethane elastomer in the intermediate layer.
Since the H layer is used, it is possible to obtain an inner container for a bag-in-box which is excellent in gas barrier property for a long period of time without cracks in the punching process during manufacturing of the inner container.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, "part" and "%" mean weight basis unless otherwise specified. Production of Resin (A) for Intermediate Layer Polyurethane elastomer obtained by reacting 80 parts of EVOH having an ethylene content of 30 mol% and a saponification degree of 97.0 mol% with a polyethylene glycol-polypropylene glycol copolymer and hexamethylene diisocyanate ( 20 parts of a urethane bond of 18.3% and a melt viscosity at 200 ° C. of 5 × 10 ³ poise) were melt-mixed at 210 ° C. to obtain a resin (A-1) for an intermediate layer. Similarly, the following intermediate layer resins (A-2 to 10) were produced.

A-2: Obtained by reacting 90 parts of EVOH having an ethylene content of 45 mol% and a saponification degree of 99.5 mol% with a polyethylene glycol-polypropylene glycol copolymer and diphenylmethane-4,4'-diisocyanate. Polyurethane elastomer (urethane bond 1
8.3%, melt viscosity at 200 ° C. of 5 × 10 ³ poise) 10 parts melt-mixed. A-3: ethylene content 45 mol%, saponification degree 99.2
Polyurethane elastomer obtained by reacting 75 parts by mol of EVOH, a polyester polyol of adipic acid and propylene glycol, and hexamethylene diisocyanate (urethane bond 21.0%, melt viscosity at 200 ° C. of 1.0 × 10 ⁴ poises, 25 parts of free isocyanate groups (0.2%) melt-mixed at 240 ° C.

A-4: The one in which the degree of polymerization of the polyethylene glycol-polypropylene glycol copolymer is increased during the production of (A-1) so that the urethane bond of the polyurethane elastomer is 3.0%. A-5: The amount of hexamethylene diisocyanate added during the production of (A-1) was increased to 60% urethane bonds in the polyurethane elastomer. A-6: A polyurethane elastomer having a melt viscosity of 5 × 10 poises added by adding a small amount of water during the production of (A-1). A-7: The reaction time during the production of (A-1) was lengthened, and the melt viscosity of the polyurethane elastomer was adjusted to 6 × 10 ^4.
Poise. A-8: The mixture ratio of EVOH and polyurethane elastomer in (A-1) is 60/40. A-9: The mixture melting temperature of EVOH and polyurethane elastomer in (A-1) was 280 ° C.

Example 1 A three-kind five-layer coextrusion apparatus was used, and the intermediate layer was the above (A-
Layer 1), both outer layers are MI (melt index) 2.5
g / 10 minutes (190 ° C, load 2160g), density 0.8
90 g / cm ³ , ethylene-1-butene random copolymer LLDPE (B-1) having an ethylene content of 90 mol%,
The adhesive layer between the intermediate layer and both outer layers had a MI of 3.0 g / 10 in which (B-1) was grafted with 0.5% maleic anhydride.
Minute (190 ° C, load 2160g) of modified LLDPE (C
-1) and (B-1) / (C-1) / (A-1)
/ (C-1) / (B-1) is 35μ / 10μ / 10μ /
A 5-layer coextrusion laminated film having a structure of 10 μ / 35 μ was obtained under the following coextrusion molding conditions. Coextrusion molding conditions : Extruder (A): 30 mmΦ, screw; full flight type, L / D; 28 Temperature conditions (° C): supply part; 180, compression part; 200, measuring part; 220 Discharge amount: 1. 5 kg / hr Extruder (B): 30 mmΦ, screw; full flight type, L / D; 26 Temperature condition (° C): Feeding section; 160, Compressing section; 200, Measuring section; 220 Discharge: 3.0 kg / hr Extruder (C): 40 mmΦ, screw; full flight type, L / D; 24 Temperature condition (° C): supply part; 200, compression part; 210, measuring part; 210 discharge amount: 10.0 kg / hr feed Block temperature: 220 ℃ Die temperature: 220 ℃

The obtained laminated film (500 mm × 70
(0 mm) were piled up, and a hole (diameter 43 mm) for liquid injection was opened by a punching machine. Next, a laminated film having no holes (500 mm × 700 mm, two sheets stacked) was laminated with the above laminated film and heat-sealed on four sides to manufacture an inner container for bag-in-box. At that time, a sealing plug made of high-density polyethylene was attached to the hole for injecting the liquid, and the periphery was heat-sealed and fixed tightly. Next, put the inner container in a cardboard box, and fill it with about 18
A running transportation test of about 2000 km was performed with the liters put. After the above test, the state of the laminated film around the sealing stopper of the inner container was visually observed by SEM (electron microscope, 500 times). The oxygen transmission rate (cc /
air * bag * day) was examined under the conditions of 20 [deg.] C. and 65% RH using an oxygen permeability measuring device (OX-TRAN10 / 50) manufactured by Modern Control.

Examples 2 and 3 Using the intermediate layer, adhesive layer and surface layer shown in Table 1, an inner container was prepared and evaluated in the same manner as in Example 1. Comparative Examples 1 to 7 Using the intermediate layer, adhesive layer, and surface layer shown in Table 1, an inner container was prepared and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results of the examples and comparative examples.

[0027]

[Table 1] Laminated layer composition ¹⁾ Evaluation item Intermediate layer Surface layer Adhesive layer SEM observation Oxygen permeability ²⁾ Example 1 A-1 B-1 C-1 No abnormalities 0.08 / 0.08 Implementation Example 2 A-2 B-2 C-2 No abnormalities 0.11 / 0.15 Example 3 A-3 B-3 C-3 No abnormalities 0.30 / 0.30 Comparative Example 1 A-4 B-1 C-1 crack generation 2.00 / 200 <Comparative example 2 A-5 B-1 C-1 crack generation 0.10 / 200 <Comparative example 3 A-6 B-1 C-1 〃 0.08 / 200 < Comparative Example 4 A-7 B-1 C-1 〃 0.13 / 200 <Comparative Example 5 A-8 B-1 C-1 No abnormalities 130/130 Comparative Example 6 A-9 B-1 C-1 * * Comparative Example 7 A-10 B-1 C-1 Crack generation 0.08 / 200 <

1) The constituent resins are as follows. A-1; (A-1) A-2; (A-2) A-3; (A-3) A-4; (A-4) A-5; (A-5) A-6; the above (A-6) A-7; the above (A-7) A-8; the above (A-8) A-9; the above (A-9) A. -10; ethylene content 30 mol%, saponification degree 9
7.0 mol% EVOH only.

B-1: MI 2.5 g / 10 minutes, density 0.
890 g / cm ³ , ethylene-1-butene random copolymer with ethylene content 90 mol% B-2; MI 4.0 g / 10 min, density 0.872 g / c
m ³ , ethylene-1-butene random copolymer with ethylene content 82 mol% B-3; MI 0.8 g / 10 min, density 0.864 g / c
m ³ , ethylene-propylene copolymer having an ethylene content of 80 mol% B-4; MI 2.0 g / 10 min, density 0.920 g / c
m ^3, an ethylene content of 97 mol% ethylene-4-methylpentene-1 copolymer C-1; the B-1 to those grafted with maleic anhydride 0.5%. C-2: A blend of 90 parts of B-1 and 10 parts of the above B-2 grafted with 2.5% of maleic anhydride. C-3: 3% maleic anhydride grafted onto B-3 above. 2) The oxygen transmission rate is represented by the value before and after the test. * A large amount of gel was generated during the production of the laminated body, making it impossible to mold the laminated body.

[0030]

INDUSTRIAL APPLICABILITY The inner container for bag-in-box according to the present invention uses an EVOH layer containing a specific polyurethane elastomer as an intermediate layer, and therefore cracks are generated in the punching process during manufacturing of the inner container. Thus, an inner container for a bag-in-box excellent in gas barrier property can be obtained, and it can withstand an impact such as transportation for a long time, which is extremely useful.

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[Procedure amendment]

[Submission date] September 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

At this time, the amount of the unsaturated carboxylic acid or its anhydride contained in the ethylene-α-olefin copolymer is preferably 0.01 to 10% by weight, more preferably 0.1 to 3% by weight. Is. If the content in the modified product is small, the adhesive strength with the intermediate layer and the surface layer will be reduced, and conversely, if it is large, a crosslinking reaction will occur and moldability will be poor, such being undesirable.
The thickness of each layer of the surface layer / adhesive layer / intermediate layer (A) / adhesive layer / surface layer laminate of the present invention is 10 to 10, respectively.
600μ / 2-50μ / 1-100μ / 2-50μ / 1
It is selected from the range of 0 to 600 μ, and preferably 30 to
200 μ / 5 to 10 μ / 5 to 30 μ / 5 to 10 μ / 30
~ 200μ.

Claims (3)

[Claims] 1. Ethylene having an ethylene content of 15 to 50 mol% and a saponification degree of a vinyl acetate component of 95 mol% or more.
70 to 98% by weight of saponified vinyl acetate copolymer, substantially free of free isocyanate groups in the molecule,
Containing 10 to 50% by weight of a urethane bond represented by: And the melt viscosity at a temperature of 200 ° C. is 1.0 × 10 ² to
5 × 10 ⁴ poise polyurethane elastomer 30 to 2
A resin composition (A) obtained by melting and mixing wt% at 180 to 250 ° C. was used as an intermediate layer, an adhesive layer was provided on both sides of the intermediate layer, and a surface layer was provided outside the adhesive layer. An inner container for a bag-in-box, which is characterized in that 2. The surface layer has a density of 0.86 to 0.95 g / c.
The inner container for bag-in-box according to claim 1, comprising an ethylene-α-olefin copolymer of m ³ (20 ° C.). 3. The density of the adhesive layer modified with an unsaturated carboxylic acid or an anhydride thereof 0.86 to 0.95 g / cm 3.
^The inner container for bag-in-box according to claim 1, which is composed of an ethylene-α-olefin copolymer of ³ (20 ° C).