JP7320993B2 - Alcohol resistant laminate - Google Patents

Description

The present invention relates to alcohol resistant laminates.

Conventionally, as a packaging bag for hermetically packaging an alcohol-containing material, for example, a packaging bag produced by heat-sealing a laminate obtained by laminating a substrate layer, a barrier layer, a sealant layer and the like with an adhesive layer interposed therebetween has been used. was

However, if the content to be packaged is, for example, a high-concentration alcohol of 50% by mass or more, the alcohol component permeates the laminate during long-term storage, especially the adhesive layer between the barrier layer and the sealant layer. As a result, there is a problem that the sealant layer is peeled off (delamination) from the barrier layer and the packaging bag is damaged. Various proposals have been made to address this problem.

In Patent Document 1, a laminate in which a substrate layer, a barrier layer, and a sealant layer are laminated in this order with an adhesive layer interposed therebetween, the barrier layer is made of a metal foil, and the barrier layer and the sealant layer are laminated. The adhesive layer between is made of a urethane-based adhesive containing a polyester polyol and an epoxy compound as a main agent and a polyisocyanate as a curing agent, and the ratio of the main agent and the curing agent is the solid content mass ratio Laminates are disclosed which are characterized by 10:1.269 to 10:2.885.

In Patent Document 2, a packaging bag for packaging a liquid having an alcohol concentration of 50% by mass or more or a liquid impregnated material, the packaging bag comprising at least a base material layer, an adhesive layer, a barrier layer, an anchor coat layer, and a polyolefin The barrier layer is an aluminum foil or a vapor deposition film, and the anchor coat layer is a polyolefin copolymer resin having a number average particle diameter of 1 μm or less. An aqueous dispersion formed so as not to contain a non-volatile water-enhancing aid is applied to the surface of the barrier layer to a thickness of 0.1 to 2 μm when dried. It is formed by heating and drying to improve the barrier property against alcohol, and the polyolefin copolymer resin contains a predetermined content of unsaturated carboxylic acid or its anhydride and (meth)acrylic acid It contains an ester, has a melting point of 90 to 110° C., and has a melt flow rate of 1 to 10 g/10 min. A packaging bag for alcohol-containing items is disclosed, which is characterized by being formed by extrusion lamination of a resin film using a similar polyolefin resin.

JP 2015-157363 A JP 2018-16370 A

There is still a need for a solution to the above delamination problem. Therefore, there is a need to provide new laminates with alcohol resistance.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and completed the present invention. That is, the present invention is as follows:
<Mode 1> Having a substrate resin layer, a substrate adhesive layer, a metal foil layer, a first adhesive layer, a barrier layer other than the metal foil layer, a second adhesive layer, and a sealant layer in this order,
Alcohol resistant laminate.
<Aspect 2> The alcohol-resistant laminate according to Aspect 1, wherein the barrier layer is an inorganic material-deposited resin layer having a vapor-deposited resin layer and an inorganic material layer directly vapor-deposited on the vapor-deposited resin layer. body.
<Aspect 3> The alcohol-resistant laminate according to Aspect 2, wherein the inorganic material layer of the inorganic material-deposited resin layer is present on the first adhesive layer side.
<Aspect 4> Aspect 2 or 3, wherein the inorganic material layer of the inorganic material-deposited resin layer is selected from the group consisting of an aluminum vapor deposition film, an alumina vapor deposition film, a silica vapor deposition film, and a silica/alumina binary vapor deposition film. alcohol resistant laminate.
<Aspect 5> The alcohol-resistant laminate according to any one of Aspects 1 to 4, wherein the second adhesive layer is a urethane adhesive layer.
<Aspect 6> The alcohol-resistant laminate according to Aspect 5, wherein the urethane adhesive layer has a repeating unit derived from polyester polyol.
<Aspect 7> In the spectrum obtained by infrared spectroscopy measurement of the urethane adhesive layer, the ratio of the area of the peak of C—N—H bending vibration to the area of the peak derived from C═O stretching vibration is The alcohol-resistant laminate according to aspect 6, which is 0.13 or more.
<Aspect 8> A bag comprising the alcohol-resistant laminate according to any one of aspects 1 to 7.
<Aspect 9> A content-filled bag comprising the bag according to aspect 8 and a content containing alcohol enclosed in the bag.

ADVANTAGE OF THE INVENTION According to this invention, the novel laminated body which has alcohol resistance can be provided.

FIG. 1 is a diagram showing the layer structure of the alcohol-resistant laminate of the present invention.

《Alcohol-resistant laminate》
As shown in FIG. 1, the alcohol-resistant laminate 100 of the present invention comprises a base resin layer 110, a base adhesive layer 112, a metal foil layer 120, a first adhesive layer 130, and a barrier layer 140 other than the metal foil layer. , a second adhesive layer 150 and a sealant layer 160 in that order.

The barrier layer 140 may be an inorganic material deposited resin layer having a deposited resin layer 144 and an inorganic material layer 142 deposited directly on the deposited resin layer 144 .

The present inventors have found that the above configuration can suppress peeling of the interface between the metal foil layer and the adhesive layer due to alcohol. Without wishing to be bound by theory, this is because in conventional bonding between an adhesive layer and a metal foil layer, the alcohol permeates the adhesive layer and reaches the surface of the metal foil layer, and then the adhesive layer and the metal foil layer. Whereas the adhesion between the adhesive layer and the metal foil layer is weakened by the inhibition of the intermolecular interaction with the foil layer and the swelling of the adhesive layer, according to the present invention, When a barrier layer other than a metal foil layer, for example, an inorganic material-deposited resin layer, is used, as indicated by arrow A in FIG. This is thought to be due to suppression of alcohol reaching the surface of the foil.

The inorganic material layer of the inorganic material-deposited resin layer is preferably present on the first adhesive layer side from the viewpoint of suppressing peeling at the interface between the inorganic material layer and the adhesive layer.

Each component of the present invention will be described below.

<Base resin layer>
As the substrate resin layer, a thermoplastic resin excellent in impact resistance, abrasion resistance, etc., such as polyolefin, vinyl-based polymer, polyester, polyamide, etc., can be used. The base resin layer may be a single layer or multiple layers, and in each layer constituting the base resin layer, the above resins may be used alone or in combination. may have been This base resin layer may be a stretched film or a non-stretched film.

Examples of polyolefins include polyethylene-based resins and polypropylene-based resins.

In this specification, a polyethylene-based resin is a resin containing more than 50 mol %, 60 mol % or more, 70 mol % or more, or 80 mol % or more of ethylene group repeating units in the main chain of the polymer. As such a polyethylene-based resin, polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE) may be used. Copolymers with ethylenic monomers having groups or ester groups may also be used.

In this specification, the polypropylene-based resin is a resin containing more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of propylene group repeating units in the main chain of the polymer, such as polypropylene (PP). Homopolymers, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, acid-modified polypropylene, derivatives thereof, and mixtures thereof.

Examples of vinyl-based polymers include polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC).

Examples of polyester include polyethylene terephthalate (PET) and polybutylene terephthalate.

Examples of polyamides include nylons such as nylon (registered trademark) 6 and nylon MXD6.

The thickness of the base resin layer is preferably 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of good protection of the metal foil layer. It is preferable from the viewpoint of improving handleability.

<Base material adhesive layer>
The substrate adhesive layer is a layer that bonds the substrate resin layer and the metal foil layer. The substrate adhesive layer may be a urethane adhesive, a hot melt adhesive, a water-soluble adhesive, an emulsion adhesive, a non-solvent laminating adhesive, a thermoplastic resin for extrusion lamination, or the like. Among them, it is preferable to use a urethane adhesive layer composed of a urethane adhesive from the viewpoint of adhesion to the metal foil layer.

As the urethane adhesive layer, for example, a polymer obtained by condensing a compound having an isocyanate group and a compound having a hydroxyl group through a urethane bond can be used. Examples of the compound having a hydroxyl group (main ingredient) include acrylic polyol, polyether polyol, polyester polyol, polycarbonate polyol, and polycapronlactone polyol. Compounds (curing agents) having an isocyanate group include hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), etc., and polymers thereof (polyisocyanates). One or more selected from the group consisting of can be used. The polymer obtained by condensing the above main agent and curing agent can have repeating units derived from a compound having a hydroxyl group and a compound having an isocyanate group, and a urethane bond.

<Metal foil layer>
As the metal foil layer, a single metal foil such as aluminum foil, copper foil or titanium foil, an alloy foil such as aluminum alloy foil or stainless steel foil, or the like can be used.

The thickness of the metal foil layer is preferably 1 μm or more, 3 μm or more, 5 μm or more, 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of ensuring strength and barrier properties. A thickness of 35 μm or less is preferable from the viewpoint of improving handleability.

<First adhesive layer>
The first adhesive layer is a layer that exists between the metal foil layer and the inorganic material-deposited resin layer. As the first adhesive layer, the adhesives mentioned for the substrate adhesive layer can be used. Among them, it is preferable to use a urethane adhesive layer composed of a urethane adhesive from the viewpoint of adhesion to the metal foil layer.

In particular, when the first adhesive layer is a urethane adhesive layer having a repeating unit derived from polyester polyol, the spectrum of the urethane adhesive layer obtained by infrared spectroscopy (IR) measurement shows 1720 cm ⁻ The ratio of the area of the peak at 1530 cm ^-1 (CNH bending vibration) to the area of the peak (C ⁼ O stretching vibration derived from the ester bond of the polyester polyol) is 0.10 or more and 0.11. or more, or 0.12 or more is preferable from the viewpoint of ensuring adhesiveness, and it is 0.16 or less, 0.15 or less, 0.14 or less, 0.13 or less, or 0.12 or less. is preferable from the viewpoint of suppressing poor appearance due to excessive generation of carbon dioxide generated by the reaction between the main agent component and the curing agent component.

For example, when using a polymer obtained by condensing a compound having an isocyanate group and a compound having a hydroxyl group through a urethane bond as the urethane adhesive, the weight of the compound having an isocyanate group (curing agent) relative to the mass of the compound having a hydroxyl group (main agent) By adjusting the ratio of masses, the ratio of areas of this peak can be adjusted. For example, the peak area ratio within the above range is such that when laminating the urethane adhesive layer, the mass ratio of the main agent and the curing agent is 9:1.0 or more, 9:1.1 or more, or 9:1. 2 or more and less than 9:2.0, 9:1.8 or less, 9:1.5 or less, 9:1.4 or less, or 9:1.3 or less. .

<Barrier layer>
A barrier layer is a barrier layer other than a metal foil layer. As such a barrier layer, a barrier resin layer, a resin layer having an organic coating film, and an inorganic material-deposited resin layer can be used.

As the resin constituting the barrier resin layer, for example, a cyclic olefin polymer, an ethylene-vinyl alcohol copolymer, polychlorotrifluoroethylene, or the like can be used.

As the resin layer having an organic coating film, a resin obtained by laminating an organic coating film such as a polyvinylidene chloride coating film, a polychlorotrifluoroethylene coating film, or a polyvinylidene fluoride coating film on the resin mentioned for the base resin layer. Layers can be used.

<Barrier layer: Inorganic material deposited resin layer>
The inorganic material vapor-deposited resin layer is a layer having a vapor-deposited resin layer and an inorganic material layer directly vapor-deposited on the vapor-deposited resin layer. As such an inorganic material vapor-deposited resin layer, a commercially available film called a "vapor-deposited film" can be used.

(Vapor-deposited resin layer)
The vapor-deposited resin layer is a layer on which the inorganic material layer is directly vapor-deposited. As the resin constituting the vapor-deposited resin layer, the resins mentioned in relation to the base resin layer can be used.

(Inorganic material layer)
The inorganic material layer is a layer directly vapor-deposited on the vapor-deposited resin layer.

The inorganic material layer may be, for example, an aluminum vapor deposition film, an alumina vapor deposition film, a silica vapor deposition film, a silica/alumina binary vapor deposition film, or the like.

The thickness of the inorganic material layer is preferably 100 nm or more, 200 nm or more, 300 nm or more, 500 nm or more, 700 nm or more, or 1 μm or more from the viewpoint of ensuring strength and barrier properties. or less, or 2 μm or less, from the viewpoint of improving handling properties as packaging.

<Second adhesive layer>
The second adhesive layer is a layer existing between the inorganic material deposited resin layer and the sealant layer. As the second adhesive layer, the adhesives mentioned for the substrate adhesive layer can be used. Among them, it is preferable to use a urethane adhesive layer composed of a urethane adhesive from the viewpoint of adhesion to the sealant layer.

In particular, when the second adhesive layer is a urethane adhesive layer having a repeating unit derived from polyester polyol, the spectrum of the urethane adhesive layer obtained by infrared spectroscopy (IR) measurement shows 1720 cm ⁻ The ratio of the peak area of 1530 ^{cm -1} (CNH bending vibration) to the peak area of 1 (C = O stretching vibration derived from the ester bond of polyester polyol) is 0.10 or more, 0 .11 or greater, 0.12 or greater, 0.13 or greater, 0.14 or greater, 0.15 or greater, or 0.16 or greater. The ratio of the areas of the peaks may be 0.50 or less, 0.45 or less, 0.40 or less, 0.35 or less, 0.30 or less, 0.25 or less, or 0.20 or less.

For example, the ratio of the peak areas within the above range is such that the mass ratio of the main agent and the curing agent when laminating the urethane adhesive layer is 9:1.0 or more, 9:1.3 or more, 9:1. 5 or more, 9:1.8 or more, and 9:4.0 or less, 9:3.5 or less, 9:3.0 or less, 9:2.5 or less, or 9:2.2 or less can be obtained by

<Sealant layer>
The sealant layer may be, for example, resins such as polyolefins, acid-modified polyolefins, ethylene methacrylic acid copolymers (EMAA), ethylene acrylic acid copolymers (EAA), ionomer resins, and ethylene vinyl acetate copolymers. These resins can be provided, for example, in the form of stretched or unstretched films, molten resins for extrusion lamination, paints for hot melt, and the like.

The thickness of the sealant layer is preferably 10 μm or more, 20 μm or more, 30 μm or more, or 40 μm or more from the viewpoint of ensuring strength, and is 200 μm or less, 180 μm or less, 150 μm or less, 130 μm or less, 100 μm or less, or 90 μm or less. , or 80 μm or less, from the viewpoint of manufacturing.

"bag"
The bag of the present invention is composed of the above alcohol-resistant laminate. The sealant layer of the alcohol resistant laminate may be located on the side that will come into contact with the contents.

In the bag of the invention, the alcohol-resistant laminate of the invention may be heat-sealed, for example, with the sealant layers facing each other. Moreover, when the bag is composed of two alcohol-resistant laminates, the two alcohol-resistant laminates may be made of the same material or may be made of different materials.

<<Bag containing contents>>
The content-filled bag of the present invention has the above-described bag and a content containing alcohol enclosed in the bag.

Contents containing alcohol include, for example, alcohol-containing antiseptic solutions, sheets impregnated with alcohol, alcoholic beverages, food products containing alcohol, and the like.

In particular, since the alcohol-resistant laminate of the present invention does not contain an epoxy compound and does not have a layer composed of an extruded resin, the content is a high-concentration alcohol, such as 30 vol % or more, 35 vol %. Above, in the case of alcoholic beverages containing 40 vol% or more, 45 vol% or more, 50 vol% or more, 55 vol% or more, or 60 vol% or more of alcohol or food containing alcohol, The present invention is beneficial because odor components and epoxy compounds and components derived therefrom do not elute into the contents.

EXAMPLES The present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these.

<<Preparation of alcohol-resistant laminate>>
<Example 1>
A nylon film (Emblem (registered trademark) ON, Unitika Ltd., thickness 15 μm) as a base resin layer, an aluminum foil as a metal foil layer, and a two-liquid urethane dry laminate adhesive ( Main agent: Takelac A-525 (polyester polyol), curing agent: Takenate A-52, Mitsui Chemicals, Inc.) were used for lamination.

Next, on the empty side of the aluminum foil, the aluminum vapor deposition film side as the inorganic material layer of aluminum vapor deposition polyethylene terephthalate (Tetraite EX-HB, Oike Pack Material Co., Ltd., thickness 12 μm) as the inorganic material vapor deposition resin layer. , A two-liquid urethane dry laminate adhesive (main agent: Takelac A-525 (polyester polyol), curing agent: Takenate A-52 (polyisocyanate), Mitsui Chemicals, Inc.) as the first adhesive layer. rice field.

Next, on the PET side of the aluminum-deposited PET, a linear low-density polyethylene sealant film (SK615P, Tamapoly Co., Ltd., thickness 50 μm) as a sealant layer was adhered to the PET side, and a two-liquid urethane dry laminate was adhered as a second adhesive layer. A laminate of Example 1 was produced by laminating using agents (main agent: Takelac A-525 (polyester polyol), curing agent: Takenate A-52, Mitsui Chemicals, Inc.). The mass ratio of the main agent and curing agent in the second adhesive layer was 9:2.

<Example 2>
A laminate of Example 2 was produced in the same manner as in Example 1, except that the mass ratio of the main agent and curing agent in the second adhesive layer was 9:1.

<Comparative Examples 1 and 2>
Laminates of Comparative Examples 1 and 2 were prepared in the same manner as in Examples 1 and 2, except that a polyethylene terephthalate film (PET-B, Unitika Ltd., thickness 12 μm) was used instead of aluminum-deposited polyethylene terephthalate. made respectively.

<Comparative Examples 3 to 4>
Laminates of Comparative Examples 3 and 4 were prepared in the same manner as in Examples 1 and 2, except that the first adhesive layer and the aluminized polyethylene terephthalate were not laminated.

"evaluation"
<Content rate of urethane bond>
Regarding Examples 1 and 2, the IR spectrum of the second adhesive layer was measured using a Fourier transform infrared spectrophotometer (FT/IR-6700, JASCO) at 1720 cm ^-1 (for the ester bond of the polyester polyol The ratio of the area of the peak at 1530 cm ⁻¹ (C—N—H bending vibration) to the area of the derived C═O stretching vibration) was measured. The above peak area ratios for the second adhesive layers of Examples 1 and 2 were 0.1614 and 0.1174, respectively.

<Initial seal strength>
The laminate thus produced was cut into pieces having a width of 15 mm, and the sealant layers were put together and heat-sealed at 200° C. for 1 sec using an impulse sealer (FA-300-10W, Fuji Impulse Co.). The seal strength (heat seal strength) of the heat-sealed portion with a width of 15 mm was measured by a T-peel test based on JIS Z 0238.

<Seal strength after exposure to ethanol>
Cut the produced laminate into a size of 160 mm × 100 mm, fold the long side direction so that the sealant layers face each other, and apply one long side and one short side with an impulse sealer (FA-300) with a width of 10 mm. −10 W, Fuji Impulse Co., Ltd.), heat-sealed at 200° C. for 1 sec to produce a bag shape. Next, this bag was filled with 40 g of a 50 vol% ethanol aqueous solution, and the remaining one side was heat-sealed under the same conditions as above to form a three-side-sealed bag. The laminate was exposed to ethanol from the sealant layer side by storing it in a constant temperature bath at a temperature of 40° C. and a relative humidity of 90% RH for 7 days.

After storage, leave at room temperature for 1 hour, cut one short side of the bag to remove the contents, and cut the bag to a width of 15 mm so as to include the heat-sealed portion. The seal strength (heat seal strength) of was measured by a T-type peel test based on JIS Z 0238.

Similar measurements were performed 5 times both at the initial stage and after exposure to ethanol, and the average value was calculated.

The ratio of the seal strength after exposure to ethanol to the initial seal strength was calculated and used as the seal strength retention rate.

<Bag breaking strength>
The above three-sided seal bag containing ethanol is installed between the upper and lower jigs of the strograph (VE100, Toyo Seiki Co., Ltd.) and pressurized at 10 mm / min until the bag breaks or stops at the upper limit (8 kN). Pressurized, and the pressure at that time was taken as the bag breaking strength.

The above measurements were performed 5 times, and the average value was calculated.

Table 1 shows the configurations and evaluation results of Examples and Comparative Examples.

From Table 1, the laminates of Examples 1 and 2 having an inorganic material-deposited resin layer have a decrease in seal strength after exposure to ethanol compared to the laminates of Comparative Examples 1 to 4 that do not have an inorganic material-deposited resin layer. can be seen to be suppressed. Also, it can be understood that the laminates of Examples 1 and 2 have higher bag-breaking strength than the laminates of Comparative Examples 1-4. From this, it can be understood that the laminates of Examples 1 and 2 have good alcohol resistance.

Also, among the examples, it can be understood that the seal strength retention rate was high in Example 1 having a high content of the curing agent.

REFERENCE SIGNS LIST 100 alcohol-resistant laminate 110 base resin layer 112 base adhesion layer 120 metal foil layer 130 first adhesion layer 140 barrier layer 142 inorganic material layer 144 vapour-deposited resin layer 150 second adhesion layer 160 sealant layer

Claims (8)

Having a substrate resin layer, a substrate adhesive layer, a metal foil layer, a first adhesive layer, a barrier layer other than the metal foil layer, a second adhesive layer, and a sealant layer in this order,
The barrier layer is an inorganic material-deposited resin layer having a vapor-deposited resin layer and an inorganic material layer directly vapor-deposited on the vapor-deposited resin layer, and
The inorganic material layer of the inorganic material-deposited resin layer is present on the first adhesive layer side,
Alcohol resistant laminate. 2. The alcohol-resistant laminate according to claim 1, wherein said second adhesive layer does not contain a metal alkoxide. 3. The alcohol-resistant according to claim 1 or 2 , wherein the inorganic material layer of the inorganic material-deposited resin layer is selected from the group consisting of an aluminum vapor deposition film, an alumina vapor deposition film, a silica vapor deposition film, and a silica/alumina binary vapor deposition film. sexual laminate. The alcohol-resistant laminate according to any one of claims 1 to 3 , wherein the second adhesive layer is a urethane adhesive layer. 5. The alcohol-resistant laminate according to claim 4 , wherein the urethane adhesive layer has repeating units derived from polyester polyol. In the spectrum of the urethane adhesive layer obtained by measurement by infrared spectroscopy, the ratio of the area of the peak of C—N—H bending vibration to the area of the peak derived from C=O stretching vibration is 0.13 or more. The alcohol-resistant laminate according to claim 5 , which is A bag made of the alcohol-resistant laminate according to any one of claims 1 to 6 . A content-filled bag, comprising: the bag according to claim 7 ; and a content containing alcohol enclosed in the bag.

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