JP6446339B2 - Alcohol barrier film, alcohol barrier multilayer film - Google Patents

Description

  The present invention relates to a film used for applications requiring alcohol barrier properties. Specifically, the present invention relates to a film used for wrapping several tens of alcohol transpiration agents together or for wrapping an article together with an alcohol transpiration agent.

  An alcohol evaporating agent in which an alcohol retaining agent that retains an alcohol such as ethanol is packaged with a film that transmits alcohol gas is known (for example, Patent Document 2). Such an alcohol transpiration agent is packaged together with food or the like for the purpose of inhibiting the growth of bacteria.

FIG. 2 shows a package of an alcohol transpiration agent. When the alcohol transpiration agent 21 is shipped from the manufacturer of the transpiration agent, several tens of them are inserted into one bag, and the insertion opening is sealed and packaged in a state where the air in the bag is deaerated.
The film 20 used for the packaging is required to have alcohol barrier properties. If the alcohol barrier property is poor, the alcohol in the alcohol transpiration agent 21 will be volatilized before being packaged together with the food, etc., and it will not be possible to prevent the bacteria from growing on the food.

  FIG. 3 shows a package in which an article 32 such as a food is packaged together with an alcohol transpiration agent 31. The film 30 used for the package is also required to have an alcohol barrier property. If the alcohol barrier property is poor, the alcohol concentration in the package will drop in a short period of time, and the effect of inhibiting the growth of bacteria will not last long.

Patent Document 1 is an invention relating to a method for preserving mold of food, and in order to prevent mold from being generated when the food is stored in a sealed bag and stored, an alcohol transpiration agent (ethanol emission product) and / or an oxygen scavenger. Coexist. The sealed bag used in the method is made of a synthetic resin film having a barrier property against oxygen and ethanol gas.
In Patent Document 1, as a synthetic resin film having a barrier property against oxygen and ethanol gas, a polyolefin film coated with polyvinylidene chloride, a nylon / polyolefin laminate film coated with the resin, or an aluminum foil laminated with polyolefin, biaxial Examples include a laminated film of stretched polypropylene and an unstretched polyolefin film, and a biaxially stretched polypropylene film (Patent Document 1, page 2, upper left column).

  Patent Document 2 is an invention related to an alcohol transpiration agent (alcohol volatilizing agent). In Examples of Patent Document 2, an alcohol transpiration agent is put into a container made of polyvinylidene chloride coated nylon / polyethylene / unstretched polypropylene, and its performance (inhibition of mold growth) is measured (Patent Document 2 [0031]). .

  Patent Document 3 is an invention related to a sandwich packaging bag, and a freshness-keeping agent (an oxygen scavenger or an alcohol transpiration agent) is bonded to the header portion of the packaging bag. The packaging bag of Patent Document 3 is made of a synthetic resin film having gas barrier properties. When the freshness-preserving agent is an alcohol transpiration agent, biaxially stretched polypropylene is exemplified as the film (Patent Document 3 [0019] ]).

Japanese Patent Laid-Open No. 3-210170 JP 2007-236245 A JP 2014-5018 A

In order to maximize the effect of the alcohol transpiration agent, a film having an alcohol gas barrier property is used for the multilayer film used for packaging the article together with the alcohol transpiration agent. A typical layer structure of the multilayer film is a base film layer / adhesive layer / sealant film layer, and the alcohol gas barrier property is usually secured by the base film layer.
As a base film excellent in alcohol gas barrier properties, a film coated with vinylidene chloride or the like, a film deposited with a metal oxide or the like is known, but both are more expensive than a general base film. It was.

  The problem to be solved by the present invention is a film used for applications requiring alcohol barrier properties, and is a multilayer film in which a relatively inexpensive base film is employed even if it is a single layer film. Even if it exists, it is providing the film which shows the outstanding alcohol barrier property.

  The present inventors do not guarantee the alcohol barrier property in the multilayer film for alcohol barrier only by the base film layer, but by using the sealant film layer, the high alcohol barrier even if a relatively inexpensive base film is used. In addition, an unstretched propylene film having a crystal melting heat of 78 ° C. or higher measured by differential scanning calorimetry of 68 J / g or higher is excellent in heat sealability and alcohol barrier properties. And found the present invention.

That is, according to the present invention, as means for solving the above-mentioned problems,
Crystal melting at 78 ° C. or higher observed when the temperature is raised from 30 ° C. to 250 ° C. at a heating rate of 10 ° C./min in a differential scanning calorimetry, which is a film mainly composed of a propylene resin and not subjected to stretching treatment. An alcohol barrier film is provided in which the heat amount is 68 J / g or more.
Moreover, in a multilayer film comprising at least a base film layer, an adhesive layer, and a sealant film layer, the multilayer film for alcohol barrier is provided, wherein the sealant film layer is composed of the film for alcohol barrier,
Furthermore, the base film is provided with the multilayer film for an alcohol barrier, wherein the base film is not subjected to coating treatment and / or vapor deposition treatment with a barrier coating agent,
Further, the multilayer film for alcohol barrier is provided, wherein the base film is a stretched nylon film.

Furthermore, according to the present invention, there is provided an alcohol transpiration agent packaging film characterized by using the alcohol barrier film or the alcohol barrier multilayer film.
Furthermore, a film for packaging an article using the alcohol barrier film or the alcohol barrier multilayer film together with an alcohol transpiration agent is provided.

The alcohol barrier film of the present invention has excellent alcohol barrier properties as well as heat seal properties.
The sealant film in the multilayer film for alcohol barrier of the present invention is also excellent in heat sealing properties and alcohol barrier properties. Therefore, the multilayer film for alcohol barrier of the present invention is excellent in alcohol barrier properties even if the substrate film is an inexpensive film.
When the alcohol barrier film or the alcohol barrier multilayer film according to the present invention is used for an alcohol transpiration agent packaging film, the alcohol in the alcohol transpiration agent is prevented from evaporating before the alcohol transpiration agent is packaged with the article. be able to.
Moreover, when the alcohol barrier film or the alcohol barrier multilayer film according to the present invention is used as a film for packaging an article together with an alcohol transpiration agent, generation of mold on the article can be suppressed for a long period of time.

It is a typical section showing the section of the multilayer film for alcohol barriers of the present invention. It is a schematic diagram of the packaging body of an alcohol transpiration agent. It is a schematic diagram of the package which packaged the goods with the alcohol transpiration agent.

  FIG. 1 is a schematic cross-sectional view of a multilayer film 10 for alcohol barrier of the present invention. The multilayer film of the present invention includes at least a base film layer 11, an adhesive layer 12, and a sealant film layer 13.

[Base film layer]
The base film layer is a layer that adds alcohol barrier properties to the multilayer film together with the sealant film layer. For example, the base film layer is an olefin resin such as polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, vinyl alcohol resin, ) Acrylic resin, styrene resin, polyethylene terephthalate, polyethylene naphthalate, ester resin such as polybutylene terephthalate, amide resin such as nylon 6 and nylon 66, and a resin composition obtained by blending these resins. Films, films obtained by selecting and laminating multiple types of these resins, films obtained by stretching these films, and coating treatments with barrier coating agents such as vinylidene chloride and ethylene-vinyl alcohol. Films, deposited treatment with metal oxides such as those of the film can be used has been subjected film.

In addition, since the multilayer film of the present invention employs a sealant film having excellent alcohol barrier properties, the base film layer is not so high in alcohol barrier properties but is relatively inexpensive and easily available. Can be suitably used.
10-40 micrometers is preferable and, as for the thickness of a base film layer, 10-30 micrometers is especially preferable. If it is thinner than 10 μm, the strength as a substrate may be insufficient, and if it is thicker than 30 μm, the multilayer film becomes hard and the cost increases.

[Adhesive layer]
The adhesive layer is formed from a dry laminating adhesive, a wet laminating adhesive, an extrusion laminating adhesive, or the like. Two-component curing urethane adhesive, polyester urethane adhesive, polyether urethane adhesive, acrylic adhesive, polyester adhesive, polyamide adhesive, epoxy adhesive, etc. However, adhesives for wet laminates include polyvinyl chloride adhesives, polyvinyl acetate adhesives, synthetic rubbers, etc., and adhesives for extrusion laminates include ethylene resins, propylene resins, ethylene copolymers, etc. Can be used.

[Sealant film layer]
The sealant film layer of the present invention is formed from a resin composition containing a propylene resin as a main component. As the propylene-based resin, a known propylene homopolymer, a random copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms, a block copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms. Examples include polymers, random terpolymers of propylene, ethylene, and α-olefins having 4 to 20 carbon atoms, block terpolymers of propylene, ethylene, and α-olefins having 4 to 20 carbon atoms, and the like. However, the present invention is not limited to this. Further, these propylene resins can be appropriately blended and used.

The resin composition forming the sealant film layer may contain other resins as subcomponents in addition to the propylene-based resin described above. Subcomponents are not particularly limited, but low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer and other ethylene resins, olefin elastomers, styrene elastomers, etc. A soft resin etc. can be illustrated. The blending ratio of the subcomponent in the resin composition forming the sealant film layer is less than 50% by weight, preferably 30% by weight or less, particularly preferably 15% by weight or less.
In addition, the resin composition may contain additives such as an antioxidant, a heat stabilizer, a weather stabilizer, a slip agent, an antiblocking agent, and a crystal nucleating agent as long as the performance is not impaired. .

  The film used for the sealant film layer of the present invention (hereinafter referred to as a sealant film) can be obtained by forming the above-described resin composition into a film shape without subjecting it to a stretching treatment. When the sealant film is stretched, the heat sealability is lowered because the molecules are oriented. In order to form a film without stretching, a T-die-casting method in which the resin is extruded from a T-die onto a casting roll and wound without being stretched, or an inflation method in which the resin is extruded into a cylindrical shape from an annular die is adopted. Good.

The sealant film of the present invention has a heat of crystal melting at 78 ° C. or higher of 68 J / g or higher. The heat of crystal melting of the film conforms to JIS K7121, and the heat of crystal melting when the film is heated from 30 ° C. to 250 ° C. at a temperature rising rate of 10 ° C./min using a differential scanning calorimeter (in the first stage) Adopt heat of fusion). Of the amount of heat of crystal melting, the portion exceeding 78 ° C. which is the boiling point of ethanol is 68 J / g or more, and particularly 69 J / g or more is excellent in alcohol barrier properties.
In addition, in order to make the amount of heat of crystal fusion within the above-mentioned range, if the cooling conditions when forming the sealant film are adjusted, or an additive for promoting crystallization is added to the resin composition forming the sealant film. good.

  Note that the sealant film of the present invention is a non-stretched film mainly composed of a propylene-based resin, and if the heat of crystal melting at 78 ° C. or higher is 68 J / g or higher, it is a single layer film. Or a multilayer film may be sufficient. The thickness of the film is not particularly limited, but is preferably about 40 to 100 μm, and particularly preferably 60 to 90 μm in consideration of heat sealing properties, alcohol barrier properties, economy, and the like.

[Alcohol barrier film]
The film used in applications requiring an alcohol barrier according to the present invention is preferably the multilayer film described above in consideration of alcohol barrier properties. However, when a lower cost alcohol barrier film is desired, the above-described sealant film can be used as it is as an alcohol barrier film.

[Production method]
The alcohol barrier multilayer film of the present invention, for example, after forming a base film and a sealant film separately, applying an adhesive to one of the base film or the sealant film, and drying the adhesive A dry laminating method in which the other is bonded, an adhesive is applied to one film, and a wet laminating method in which the other is bonded without drying the adhesive, a molten adhesive between the base film and the sealant film It can be produced by an extrusion lamination (sand lamination) method or the like.
In addition, when the base film is a multilayer film, after forming a multilayer base film in advance, it may be laminated with a sealant film, but after laminating a part of the base film and the sealant film, The remaining base film may be laminated.

[Packaging]
FIG. 2 is a schematic view of a package in which a large number of alcohol transpiration agents 21 are packaged with the multilayer film 20 of the present invention. FIG. 3 is a schematic view of a packaging body in which the article 32 is packaged with the alcohol transpiration agent 31 and the multilayer film 30 for alcohol barrier of the present invention.
The alcohol evaporating agents 21 and 31 are not particularly limited as long as they can evaporate alcohol gas, and an alcohol adsorbent obtained by absorbing ethanol in an adsorbent such as mica or silica is filled in an alcohol gas permeable sachet. Can be used. It is also possible to fill a sachet with some oxygen absorber together with the alcohol adsorbent.
Since the alcohol transpiration agent has a high fungus growth inhibitory effect, the alcohol barrier film and the alcohol barrier multilayer film 30 of the present invention are suitably used when the article 32 is an article that dislikes the occurrence of mold such as breads and confectionery. used.

First, the relationship between the amount of heat of crystal melting and the alcohol barrier property of a single-layer alcohol barrier film is confirmed.
For Examples 1 to 5 and Comparative Example 1, the heat of crystal fusion and the alcohol barrier property are measured. The measuring method is as follows.

[Crystal melting heat]
In accordance with JIS-K7121 (2012), measurement is performed using a differential scanning calorimeter EXSTAR6000-DSC6200R manufactured by SII Nanotechnology. In the present invention, the amount of heat of crystal melting is the amount of heat of crystal melting (the amount of heat of fusion in the first stage) when the temperature is raised from 30 ° C. to 250 ° C. at a rate of temperature increase of 10 ° C./min. Table 1 shows the total heat of crystal fusion from 30 ° C to 250 ° C and the heat of crystal fusion in the temperature region of 78 ° C or higher.

[Alcohol barrier properties]
From the alcohol barrier films described in Examples 1 to 4 and Comparative Example 1, a square bag having an inner size of 5 cm × 5 cm is prepared, and 10 cc of ethanol is enclosed in the bag to prepare a test package. Next, the package is left under constant temperature and humidity (room temperature 40 ° C., humidity 50% RH) for 24 hours. The amount of alcohol decrease (g / m ² · day) is determined from the weight change of the package before and after being left, and the alcohol barrier property is evaluated. The results are shown in Table 1.
The alcohol reduction amount A can be obtained by the following formula, where a is the initial weight of the package and b is the weight after standing under constant temperature and humidity.
A = (ab) /0.005

[Example 1]
Toray Film Processing Co., Ltd., unstretched polypropylene film, Treffan NO ZK99S (80 μm)
[Example 2]
Toyobo Co., Ltd., unstretched polypropylene film, Pyrene (registered trademark) film-CTP 1147 (80 μm)
[Example 3]
Non-stretched polypropylene film FRTK-G (80 μm) manufactured by Futamura Chemical Co., Ltd.
[Example 4]
Toyobo Co., Ltd., unstretched polypropylene film, pyrene (registered trademark) film-CTP 1146 (80 μm)
[Comparative Example 1]
Unstretched polypropylene film RXC-22 (80 μm) manufactured by Mitsui Chemicals, Inc.

  As is apparent from Table 1, films for alcohol barrier (Examples 1 to 4) having a heat of fusion of 68 J / g or more in a temperature region of 78 ° C. or more, particularly films of 69 J / g or more (Examples 1 to 3). ) Had a small amount of alcohol reduction and excellent alcohol barrier properties. The alcohol barrier film of Comparative Example 1 had a relatively high heat of fusion for all crystals, but had a low heat of fusion in the region of 78 ° C. or higher and a low alcohol barrier property.

  Subsequently, the alcohol barrier film of Example 1 and Comparative Example 1 described above was used as a sealant film, and a multilayer film for alcohol barrier was produced in the following manner, and the alcohol barrier property was measured. The method for measuring the alcohol barrier property is as described above.

[Example 5]
A stretched nylon film having a thickness of 15 μm is used as a base film, and the film of Example 1 described above is used as a sealant film. These films are laminated using an adhesive for dry lamination to produce a multilayer film for alcohol barrier of Example 5. did. The measurement results of the alcohol barrier properties of the film are shown in Table 2.

[Comparative Example 2]
A multilayer film of Comparative Example 2 was produced in the same manner as in Example 5 except that the film of Comparative Example 1 described above was used as the sealant film. The measurement results of the alcohol barrier properties of the film are shown in Table 2.

  The multilayer film of Example 5 using a film having a crystal melting amount of 68 J / g or more in a temperature region of 78 ° C. or higher as the sealant film was a stretched nylon film that was not deposited or coated as the base film. Nevertheless, the alcohol barrier property was excellent. On the other hand, the packaging material of Comparative Example 2 had a high amount of ethanol permeation and was similar to the alcohol barrier film of Example 3.

  The film for alcohol barrier and multilayer film for alcohol barrier of the present invention are used without particular limitation for applications where alcohol barrier properties are required, such as applications for collectively packaging alcohol transpiration agents and applications for packaging articles together with alcohol transpiration agents. can do. For example, it can be suitably used in a packaging form for packaging with alcohol gas replacement.

10, 20, 30 Multilayer film for alcohol barrier 11 Base film layer 12 Adhesive layer 13 Sealant film layer (alcohol barrier film)
21, 31 Alcohol transpiration agent 32

Claims (6)

It is a non-stretched film mainly composed of a propylene resin,
A film for an alcohol barrier, characterized in that a crystal melting calorie of 78 ° C. or higher observed when the temperature is raised from 30 ° C. to 250 ° C. at a heating rate of 10 ° C./min in differential scanning calorimetry is 68 J / g or higher. In a multilayer film comprising at least a base film layer, an adhesive layer, and a sealant film layer,
The multilayer film for an alcohol barrier, wherein the sealant film layer comprises the film for an alcohol barrier according to claim 1.   3. The multilayer film for alcohol barrier according to claim 2, wherein the base film is not subjected to coating treatment and / or vapor deposition treatment with a barrier coating agent.   The multilayer film for alcohol barrier according to claim 2 or 3, wherein the base film is a stretched nylon film.   A film for packaging an alcohol transpiration agent, wherein the film for alcohol barrier according to claim 1 or the multilayer film for alcohol barrier according to any one of claims 2 to 4 is used. A film for packaging an article together with an alcohol transpiration agent, wherein the film for alcohol barrier according to claim 1 or the multilayer film for alcohol barrier according to any one of claims 2 to 4 is used.