JP7302153B2 - Low adsorption resin film for packaging - Google Patents

Description

The present invention provides a low-adsorptive resin film excellent in aroma retention, and a low-adsorptive laminate and low-adsorptive It relates to packaging materials and low-adsorptive packages.

Regarding a container made using a laminate having excellent aroma retention properties, for example, Patent Document 1 describes a barrier layer in which an acrylonitrile resin film and an ethylene-vinyl alcohol copolymer film are laminated, and a polyolefin resin film is attached to both sides of the barrier layer. or a barrier layer composed of a first transparent resin film layer, an inorganic oxide vapor deposition layer, and a second transparent resin film layer in Patent Document 2. A structure in which polyolefin resin films are laminated on both sides and the like are disclosed.

Further, Patent Document 3 discloses a paper container made from a laminate having an aroma-retaining resin layer, a polypropylene layer, and a gas barrier layer, and Patent Document 4 discloses a layer containing a polypropylene resin and an α-olefin copolymer. is disclosed.

However, in these, although the polyolefin resin layer laminated on the inner surface side of the barrier layer prevents the aroma components from escaping to the outside of the container, the polyolefin resin layer itself adsorbs the aroma components. was not prevented, and the aromatic components were adsorbed in proportion to the thickness of the polyolefin resin layer.

Actual fair 2-45000 Japanese Utility Model Laid-Open Showa 63-64638 JP-A-2000-135764 Japanese Patent Application Laid-Open No. 2003-312718

The present invention has been intensively studied in view of the above, and has excellent aroma retention properties due to excellent low adsorption and low permeability of aroma components, especially ethyl caproate and / or isoamyl acetate. An object of the present invention is to provide a low-adsorptive resin film for packaging excellent in maintaining the flavor of a product, and furthermore, to provide a laminate, a packaging material, a package, and a paper container for liquid using the resin film.

The low-adsorptive resin film for packaging of the present invention has excellent low-adsorption and low-permeability of ethyl caproate and / or isoamyl acetate, which are the aroma components of the contents, by containing the cyclic olefin resin. It exhibits fragrance retention.
The present invention is characterized by the following points.
1. A low-adsorptive resin film for packaging, comprising a cyclic olefin-based resin for suppressing adsorption and permeation of ethyl caproate and/or isoamyl acetate.
2. 2. The low-adsorptive resin film according to 1 above, wherein the cyclic olefin-based resin is a polynorbornene-based resin.
3. 2. The low-adsorptive resin film according to 1 above, wherein the cyclic olefin resin is a copolymer of a norbornene-based monomer and an alkene monomer.
4. 4. The low-adsorptive resin film according to any one of items 1 to 3, further comprising low-density polyethylene and/or linear low-density polyethylene.
5. The low-adsorptive resin film has a cyclic olefin-based resin layer and a polyethylene layer,
The cyclic olefin resin layer contains the cyclic olefin resin,
The polyethylene layer does not contain the cyclic olefin-based resin, and contains the linear low-density polyethylene and/or the low-density polyethylene,
4. The low-adsorptive resin film as described in 4 above.
6. The outermost surface of one side of the low-adsorptive resin film is the polyethylene layer,
5. The low-adsorptive resin film as described in 5 above.
7. The polyethylene layer has a layer made of the low-density polyethylene and a layer made of the linear low-density polyethylene,
The outermost surface of one side of the low-adsorptive resin film is a layer made of the low-density polyethylene,
7. The low-adsorptive resin film according to 5 or 6 above.
8. The cyclic olefin resin layer is
A layer in which the cyclic olefin resin is 80% by mass or more and 97% by mass or less and the low-density polyethylene is 3% by mass or more and 20% by mass or less in all resin components;
In all resin components, the cyclic olefin resin is 15% by mass or more and 60% by mass or less, the linear low-density polyethylene is 30% by mass or more and 80% by mass or less, and the low-density polyethylene is 3% by mass or more and 10% by mass or less, and has a layer laminated on the outermost surface of the laminate, The low-adsorptive resin film according to any one of 5 to 7 above. .
9. 9. The low adsorption according to any one of 5 to 8 above, wherein the thickness of the cyclic olefin resin layer is 20% or more and 50% or less of the total thickness of the low adsorption resin film. flexible resin film.
10. 10. The low-adsorptive resin film as described in any one of 1 to 9 above, wherein the total thickness is 20 μm or more and 150 μm or less.
11. 11. The low-adsorptive resin film as described in any one of 1 to 10 above, wherein the layers constituting the low-adsorptive resin film are layers formed by extrusion or co-extrusion.
12. 12. A low-adsorptive sealant film comprising the low-adsorptive resin film according to any one of 1 to 11 above.
13. A low-adsorptive laminate having at least a substrate layer and a low-adsorptive sealant layer,
The low-adsorptive sealant layer is a surface layer on one side of the low-adsorptive laminate and is composed of the low-adsorptive sealant film described in 12 above, and the outermost surface layer, which is the outermost layer of the laminate, is the above-mentioned A low-adsorptive laminate, characterized by being a cyclic olefin-based resin layer.
14. further comprising a barrier layer between the substrate layer and the low-adsorptive sealant layer;
14. The low-adsorptive laminate according to 13 above, wherein the barrier layer is one or more selected from the group consisting of metal foil, vapor-deposited metal film, and vapor-deposited metal oxide film.
15. Furthermore, a printed layer is provided on the surface of the base material layer opposite to the low-adsorptive sealant layer,
15. The low adsorptive laminate as described in 13 or 14 above.
16. 16. The low-adsorptive laminate according to any one of 13 to 15 above, wherein the base material layer has a layer made of a paper material.
17. 17. The low adsorptive laminate of Claim 16, further comprising a protective layer on the side of the paper material opposite to the low adsorptive sealant layer.
18. A low-adsorptive packaging material comprising the low-adsorptive laminate according to any one of 13 to 17 above.
19. 19. A low-adsorptive packaging bag, which is produced using the low-adsorptive packaging material described in 18 above so that the low-adsorptive sealant layer serves as a content layer.
20. A low-adsorption packaging material comprising the low-adsorption laminate according to 16 or 17 above, wherein the low-adsorption sealant layer is made into a layer containing the content, using the low-adsorption packaging material. liquid carton.

INDUSTRIAL APPLICABILITY According to the present invention, a low-adsorptive resin film for packaging which is excellent in low-adsorptivity and low-permeability of aromatic components, particularly ethyl caproate and/or isoamyl acetate, and is excellent in flavor retention and flavor retention of contents. Furthermore, laminates, packaging materials, packages, and paper containers for liquids can be obtained using the low-adsorptive resin film.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows the example about the layer structure of the low adsorption resin film for packaging of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of a low-adsorptive laminate of the present invention;

A low-adsorptive resin film for packaging of the present invention, a low-adsorptive sealant film made of the low-adsorptive resin film, a low-adsorptive laminate containing the low-adsorptive sealant film as a sealant layer, and a low-adsorptive laminate from the low-adsorptive laminate The manufactured low-adsorptive packaging material, low-adsorptive packaging bag, and low-adsorptive liquid paper container will be described in detail below. The present invention will be described by showing a specific example, but the present invention is not limited to this.

<Low adsorptive resin film for packaging>
The low-adsorptive resin film for packaging of the present invention is a resin film containing a cyclic olefin resin for suppressing adsorption and permeation of ethyl caproate and/or isoamyl acetate.
The low-adsorptive resin film for packaging of the present invention may have a single-layer structure or a multi-layer structure of two or more layers, preferably a multi-layer structure of two or more layers.
In the case of a multilayer structure, the composition of each layer may be the same or different, and may include a layer that does not contain a cyclic olefin resin, and two or more layers with different contents of the cyclic olefin resin. layer may be included.

Additionally, the low adsorption resin film can optionally contain low density polyethylene (LDPE) and/or linear low density polyethylene (LLDPE). The low-density polyethylene and/or linear low-density polyethylene may be contained by being mixed with the cyclic olefin resin, or may be contained in the resin film as a polyethylene layer containing no cyclic olefin resin.

The low-adsorptive resin film for packaging of the present invention preferably has a layer structure in which, for example, a polyethylene layer is laminated on the outermost surface of one side.
The lamination strength of the laminate can be improved by using one side of the polyethylene layer as an adhesive surface when producing the laminate.
The surface layer on the other side is preferably a layer containing a cyclic olefin resin.
By using the surface layer as a content layer in the package, adsorption and permeation of aromatic components can be suppressed.

In addition, the low-adsorptive resin film has anti-blocking properties, workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, For the purpose of improving and modifying anti-mold properties, electrical properties, strength, etc., anti-blocking agents, lubricants, cross-linking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, anti-static agents, Plastic compounding agents such as pigments, additives, and the like can be added, and the amount thereof can be arbitrarily added according to the purpose within a range that does not adversely affect other performances.
Of these, antiblocking agents, lubricants, etc. can be efficiently added by adding only to the outermost layer of the low-adsorptive resin film when the low-adsorptive resin film has a multi-layer structure. .

Furthermore, the surface of the low-adsorptive resin film or each layer constituting the low-adsorptive resin film is subjected to corona discharge treatment, ozone treatment, oxygen gas or nitrogen gas treatment in advance before lamination in order to improve adhesion. A physical treatment such as a low-temperature plasma treatment using , a glow discharge treatment, or a chemical treatment such as an oxidation treatment using a chemical agent can also be performed.
The total thickness of the low-adsorptive resin film is preferably 20 μm or more and 150 μm or less. If it is thinner than the above range, the aroma retention may become insufficient. It tends to be difficult to pick.

The thickness of the cyclic olefin resin-containing layer is preferably 20% or more and 50% or less of the total thickness of the low-adsorptive resin film. If it is thinner than the above range, the aroma retention may become insufficient. It tends to be difficult to pick.

(Method for producing low-adsorptive resin film)
In the present invention, the low-adsorptive resin film and each layer in the low-adsorptive resin film are not particularly limited in film-forming and lamination methods, and known or commonly used film-forming methods and lamination methods can be applied.
Each layer constituting the low-adsorptive resin film is optionally extruded or co-extruded onto another layer via an adhesive layer and laminated by an extrusion coating method, or multiple layers are extruded or co-extruded and laminated by an inflation method. It can also be formed by a casting method.
Alternatively, pre-formed films of each layer may be laminated via an adhesive layer by an adhesive extrusion coating method, dry lamination method, non-solvent lamination method, or the like.

When laminating by an extrusion coating method, first, the resin or resin composition forming each layer is heated and melted, expanded and stretched in the necessary width direction with a T-die, and extruded in a curtain shape, and the melted product. is allowed to flow down onto the surface to be laminated, and sandwiched between the rubber roll and the cooled metal roll, formation of each layer, adhesion to the surface to be laminated, and lamination can be performed simultaneously.

The melt flow rate (MFR) of the resin or resin composition of each layer when laminated by extrusion coating is preferably 0.2 to 50 g/10 minutes, more preferably 0.5 to 30 g/10 minutes. preferable. If the MFR is lower or higher than the above range, the processability tends to be poor. In addition, MFR is the value measured by the method based on JISK7210.

When the inflation method is used, the melt flow rate (MFR) of the resin or resin composition of each layer is preferably 0.2 to 10 g/10 minutes, more preferably 0.2 to 9.5 g/10 minutes. . If the MFR is lower or higher than the above range, the processability tends to be poor.

[Aroma component]
In the present invention, especially, ethyl caproate and/or isoamyl acetate are used as fragrance components.
Ethyl caproate and isoamyl acetate are aroma components contained in large amounts in shochu and sake.

[Cyclic olefin resin]
The cyclic olefin-based resin is a resin component that has excellent low permeability of aromatic components and excellent low adsorption of aromatic components. It has excellent low adsorption and low permeability to ethyl caproate and/or isoamyl acetate, which are aromatic components, and exhibits fragrance retention.

Cyclic olefin-based resins are resins having a cyclic structure obtained by polymerizing cyclic olefins with each other or by copolymerizing cyclic olefins with alkene monomers or the like. Here, each of the cyclic olefin and the alkene monomer may be a single species or a mixture of multiple species.
The cyclic olefin-based resin is preferably a polynorbornene-based resin using a norbornene-based monomer as the cyclic olefin, and more preferably a copolymer of a norbornene-based monomer and an alkene monomer.
A norbornene-based monomer is a compound having a bicyclo[2.2.1]hept-2-ene (norbornene) skeleton.

Specifically, for example, bicyclo[2.2.1]hept-2-ene and its derivatives, tricyclo[4.3.0.1 ^2.5 ]-3-decene and its derivatives, tricyclo[4.4 .0.1 ^2.5 ]-3-undecene and its derivatives, tetracyclo[4.4.0.1 ^2.5 . 1 ^7.10 ]-3-dodecene and its derivatives, pentacyclo[6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ]-4-pentadecene and its derivatives, pentacyclo[7.4.0.1 ^2.5 . ^19.12 . 0 ^8.13 ]-3-pentadecene and its derivatives, pentacyclo[6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ]-4,10-pentadecadiene and its derivatives, pentacyclo[8.4.0.1 ^2.5 . ^19.12 . 0 ^8.13 ]-3-hexadecene and derivatives thereof, and the like, but are not limited thereto. These norbornene-based monomers may have polar groups such as ester groups, carboxyl groups, and carboxylic anhydride groups as substituents. These compounds may be used alone or in combination of two or more.
Among these, bicyclo[2.2.1]hept-2-ene (norbornene) is preferable as the norbornene-based monomer.

As alkene monomers, α-olefin monomers are preferred, and specific examples include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene. etc. These compounds may be used alone or in combination of two or more.
Among these, ethylene is preferable as the alkene monomer.
Although the glass transition temperature (Tg) of the cyclic olefin resin is not particularly limited, it is preferably 60° C. or higher and 170° C. or lower because it is easy to handle as a raw material resin for packaging materials.

[Cyclic olefin resin layer]
In the low-adsorptive resin film of the present invention, the cyclic olefin-based resin layer is a layer that is excellent in low permeability and low absorptivity of aromatic components.

The cyclic olefin-based resin layer may be a layer composed only of a cyclic olefin-based resin, or a layer composed of a mixture of a cyclic olefin-based resin and another type of thermoplastic resin. Another preferred type of thermoplastic resin is polyethylene. Among these, a layer made of a mixture of a cyclic olefin resin, linear low-density polyethylene and/or low-density polyethylene is more preferable.
The cyclic olefin-based resin layer may have a single layer structure consisting of one layer or a multilayer structure consisting of two or more layers, preferably a multilayer structure consisting of two or more layers.

In addition, the cyclic olefin resin layer is preferably laminated as the outermost layer on one side surface of the low-adsorptive resin film. It is preferable that a cyclic olefin-based resin-containing layer having a low content of or a cyclic olefin-based resin-containing layer containing low-density polyethylene be laminated. The lower limit of the content of the cyclic olefin resin in the outermost layer is preferably 15% by mass or more, and the upper limit is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less.

For example, the cyclic olefin-based resin layer has a cyclic olefin-based resin content of 80% by mass or more and 97% by mass or less, and a low-density polyethylene content of 3% by mass or more and 20% by mass. The content of the cyclic olefin resin layer is 15% by mass or more and 60% by mass or less in the total resin components, and the content of the linear low-density polyethylene is 30% by mass or more and 80% by mass or less, the content of low-density polyethylene is 3% by mass or more and 10% by mass or less, and a cyclic olefin resin layer laminated on the outermost surface of the laminate. is preferred.
By using the layer structure as described above, an excellent balance between low adsorptivity, low permeability, and heat-sealing properties can be achieved.

[Polyethylene layer]
The low-adsorptive resin film of the present invention can optionally contain a polyethylene layer.
A polyethylene layer is a layer which does not contain cyclic olefin system resin but contains polyethylene. Here, the polyethylene is preferably linear low density polyethylene and/or low density polyethylene.
The polyethylene layer may have two or more layers with different compositions in the low-adsorptive resin film. For example, a layer made of low-density polyethylene and a layer made of linear low-density polyethylene are laminated. is preferred.

The polyethylene layer is preferably laminated on the outermost surface of one side of the low-adsorptive resin film, and furthermore, a layer made of low-density polyethylene is laminated on the outermost surface of one side of the low-adsorptive resin film. more preferred. Due to the above layer structure, the low-adsorptive resin film is used as a sealant film, and when forming the sealant layer of the laminate, by laminating this polyethylene layer as an adhesive surface, excellent lamination strength is exhibited. can be done.

<Low adsorption sealant film>
The low-adsorptive sealant film of the present invention is a sealant film produced from the low-adsorptive resin film of the present invention, and if necessary, layers having various functions are laminated on the low-adsorptive resin film of the present invention. It can also be produced by

<Low adsorptive laminate>
The low-adsorptive laminate of the present invention is a laminate having a substrate layer and a low-adsorptive sealant layer,
The low-adsorption sealant layer is the surface layer on one side of the low-adsorption laminate.
The low-adsorption laminate of the present invention can further optionally have a barrier layer between the substrate layer and the low-adsorption sealant layer.
Also, if desired, a printed layer can be provided on the opposite side of the substrate layer from the low-adsorption sealant layer.

(Base material layer)
Any film or sheet can be used for the substrate layer of the low-adsorptive laminate of the present invention depending on the application of the low-adsorptive laminate. For example, when applied to a pouch or a box-shaped container for hermetically packaging liquid contents, it is preferable that the adhesive be excellent in mechanical strength such as tensile strength, bending strength, and impact strength, and to be excellent in printability.
For the substrate layer, for example, a biaxially oriented nylon film, a biaxially oriented polyester film such as a biaxially oriented polyethylene terephthalate film, a biaxially oriented polypropylene film, and the like can be suitably used, and paper materials and the like can also be used. . These may be used singly or in combination.

Furthermore, in order to improve adhesion, an adhesive layer is provided on the surface of the base material layer or between each layer constituting the base material layer, or the surface of each layer is optionally subjected to a desired surface treatment in advance. Layers can be provided.
For example, pretreatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc. is optionally applied to the corona treatment layer and ozone treatment. Layers, plasma-treated layers, oxidation-treated layers, etc. can be formed and provided.
Alternatively, various coating agent layers such as a primer coating agent layer, an undercoat agent layer, an anchor coating agent layer, an adhesive layer, and a vapor deposition anchor coating agent layer can be arbitrarily formed on the surface to serve as the surface treatment layer. .

When the substrate layer includes a layer made of paper material, it is preferable to further have a protective layer on the surface of the paper material opposite to the low-adsorptive sealant layer. The protective layer improves the water resistance of the substrate layer when the content is a wet content, and preferably contains a polyethylene-based resin.

(Print layer)
There is no particular limitation on the printed content of the printed layer. For example, there are letters, monochromatic solid patterns, bright and dark color patterns, uneven patterns, and those exhibiting diffraction gloss due to unevenness.
Moreover, it may be formed by printing with a printing machine, may be drawn with a writing tool, or may be a laminate of films or sheets having patterns and letters.
The thickness of the printed layer can be appropriately determined by those skilled in the art according to the printed content and the application of the low-adsorptive laminate, but it is preferably 5 to 500 μm, more preferably 10 to 300 μm.
Various surface treatments may be applied to the surface of the printed layer, if necessary, in order to improve adhesion.

(barrier layer)
In the low-adsorptive laminate of the present invention, the barrier layer is a layer laminated between the substrate layer and the low-adsorptive sealant layer, and is a layer exhibiting gas barrier properties and aroma retention properties.
In the present invention, the barrier layer may be one or more selected from the group consisting of a metal foil, a metal vapor deposition film, and a metal oxide vapor deposition film.
By including the barrier layer as described above, the gas barrier property of the laminate can be improved, the effect of preventing the oxidation of the contents and the dissipation of the flavor components can be enhanced, and the effect of maintaining the flavor of the contents can be enhanced. can.

(Low adsorptive sealant layer)
The low-adsorptive sealant layer in the low-adsorptive laminate of the present invention is a surface layer on one side of the low-adsorbent laminate, is a layer made of the low-adsorbent sealant film of the present invention, and is the outermost layer of the laminate. The outermost surface is a layer containing a cyclic olefin resin.
The low adsorption sealant layer has low adsorption and low permeability of ethyl caproate and/or isoamyl acetate and heat sealability.
When all of the low-adsorptive sealant layers in the present invention are formed only from the low-adsorptive sealant film, the above-described layer structure of the low-adsorptive sealant film is directly applied to the structure of the low-adsorptive sealant layer.

The low-adsorptive sealant layer may consist of one or more layers.
In the case where the low-adsorptive sealant layer has a multilayer structure of two or more layers, layers other than the layer formed from the low-adsorptive sealant film of the present invention, which are laminated by melt (co) extrusion coating, and adhesives are added. It may also contain a layer of film laminated via.

In the low-adsorptive laminate of the present invention, the layer containing the cyclic olefin-based resin, which is the outermost surface on the low-adsorbent sealant layer side, may be the cyclic olefin-based resin layer in the low-adsorbent sealant film of the present invention, Furthermore, when the cyclic olefin resin layer has a multilayer structure, the layer preferably has a relatively low content of the cyclic olefin resin in order to obtain high heat-sealing properties. More preferably, it is a layer containing a mixture of density polyethylene.
Further, the surface layer of the low-adsorptive sealant layer on the other substrate layer side is preferably a polyethylene layer in order to obtain excellent lamination strength.
Furthermore, the low-adsorptive sealant layer is preferably laminated in the low-adsorptive laminate of the present invention via an adhesive layer.

(adhesive layer)
In the present invention, each layer can be adhered by an adhesive layer.
The adhesive layer can be formed using generally known dry lamination adhesives, EC (extrusion coat) adhesives, non-solvent lamination adhesives, arbitrary anchor coat agents, and the like.
The adhesive may be of a thermosetting type, an ultraviolet curable type, an electron beam curable type, or the like, and may be in any form such as an aqueous type, a solution type, an emulsion type, or a dispersion type. It may be in any form such as shape, powder, solid, etc. Further, the adhesion mechanism may be in any form such as chemical reaction type, solvent volatilization type, heat fusion type, heat pressure type, or the like.

<Low adsorption packaging materials>
The low-adsorptive packaging material of the present invention is a packaging material produced using the low-adsorptive laminate of the present invention.
<Low adsorption packaging bag>
The low-adsorptive packaging bag of the present invention is a packaging bag produced using the low-adsorptive packaging material of the present invention so that the low-adsorptive sealant layer serves as the content layer.

For example, using the low-adsorptive packaging material of the present invention, folding it in two, or preparing two low-adsorptive packaging materials, overlapping the surfaces of the low-adsorptive sealant layers facing each other, and The peripheral edge is, for example, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope-pasted seal type, a joint-pasted seal type (pillow seal type), a pleated seal type, a flat-bottomed seal type, or a corner. Various types of packaging bags can be manufactured by heat-sealing in a heat-sealing form such as a bottom-seal type or a gusset type.
In the above, as the heat sealing method, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing can be used.

<Paper container for low-adsorptive liquid>
The low-adsorptive liquid paper container of the present invention is made by using the low-adsorptive packaging material of the present invention having a paper material in the base material layer, and is box-manufactured so that the low-adsorptive sealant layer becomes the content layer. It is a paper container for liquids.

In the examples, the following raw materials were used.
COC1: Polyplastics Co., Ltd. cyclic olefin resin, TOPAS ^(R) 8007F-600, norbornene-derived repeating unit content of 65% by mass, glass transition temperature of 78°C.
LLDPE1: LLDPE manufactured by Ube Maruzen Polyethylene Co., Ltd., Yumerit ^(R) 0520F, MFR 2 g/10 minutes, density 0.904 g/cm ³ .
LLDPE2: LLDPE manufactured by Prime Polymer Co., Ltd., Ultozex ^(R) 1520L, MFR 2.3 g/10 min, density 0.914 g/cm ³ ).
LLDPE film 3: LLDPE film, TUX-MCS, manufactured by Mitsui Chemicals Tohcello. 40 μm thick.
LDPE1: Suntech M6525.
LDPE2: LDPE manufactured by Nippon Polyethylene Co., Ltd., Novatec ^(R) LC522, MFR 4.0 g/10 min, density 0.923 g/cm ³ .
PET film 1: Biaxially stretched polyethylene terephthalate film E-5100 manufactured by Toyobo Co., Ltd.; thickness 12 μm.
Aluminum foil 1: A1N30H-O manufactured by Nippon Foil Co., Ltd. 7 μm thick.
Adhesive 1: Rock Bond J/Adlock manufactured by Rock Paint Co., Ltd. Blending mass ratio RU77T/H-7=10/1.
Anti-blocking agent masterbatch: EMB-21 manufactured by Sumitomo Chemical Co., Ltd. MFR 4 g/10 min, containing synthetic zeolite. The mass ratio of synthetic zeolite/LLDPE is 10/90.

[Preparation of resin composition for cyclic olefin resin layer]
(Preparation of resin composition 1)
A resin composition 1 was obtained by mixing and kneading the following raw materials.
COC1 95 parts by mass LDPE1 5 parts by mass

(Preparation of resin composition 2)
A resin composition 2 was obtained by mixing and kneading the following raw materials.
The mass ratio of cyclic olefin resin/linear low density polyethylene/low density polyethylene is 40/45+9/5=40/54/5.
COC1 40 parts by mass LLDPE1 45 parts by mass LDPE1 5 parts by mass Anti-blocking agent masterbatch 10 parts by mass

(Preparation of resin composition 3)
The following raw materials were mixed and sufficiently kneaded to obtain a resin composition 3.
The mass ratio of cyclic olefin resin/linear low density polyethylene/low density polyethylene is
15/50+27/5=15/77/5.
COC1 15 parts by mass LDPE1 5 parts by mass LLDPE1 50 parts by mass Antiblocking agent masterbatch 30 parts by mass

<Preparation and evaluation of low-adsorptive resin film>
[Example 1]
The layer structure of the low-adsorptive resin film to be produced is as follows. In addition, "/" indicates that the left and right layers are laminated and integrated.
LDPE2 as the resin forming the polyethylene layers 1 and 2, LLDPE2 as the resin forming the polyethylene layer 3, COC1 as the resin forming the cyclic olefin resin layer 1, and the resin forming the cyclic olefin resin layer 2 obtained above. A resin composition 1 was selected, and a low-adsorptive resin film 1 (thickness: 40 μm) was produced by a five-layer co-extrusion film-forming method using an inflation method, and various evaluations were performed.
Polyethylene layer 1 (7.5 μm)/polyethylene layer 2 (7.5 μm)/polyethylene layer 3 (10 μm)/cyclic olefin resin layer 1 (7.5 μm)/cyclic olefin resin layer 2 (7.5 μm)

[Examples 2 to 4]
A low-adsorptive resin film was produced in the same manner as in Example 1, except that the thickness of the cyclic olefin resin layer 1 and the type and thickness of the resin composition of the cyclic olefin resin layer 2 were changed according to Table 1. 2 to 4 were produced.

<Production and evaluation of low-adsorptive packaging materials>
[Example 5]
The layer structure of the low-adsorptive packaging material to be produced is as follows.
As a base material, a PET film 1 and an aluminum foil 1 were bonded together using an adhesive 1, and the aluminum foil surface and the polyethylene layer side surface of the low-adsorptive resin film obtained in Example 1 above were bonded. facing each other and pasted together via the adhesive 1 to obtain a low-adsorptive packaging material. Then, various evaluations were performed. Details are shown in Table 3.
PET film 1 (12 μm)/adhesive 1 (3 g/m ² )/aluminum foil 1 (7 μm)/adhesive 1 (3 g/m ² )/low adsorptive resin film 1 (40 μm)

[Examples 6 to 8, Comparative Example 1]
The low-adsorptive resin film 1 was changed to the low-adsorptive resin films 2-4 of Examples 2-4 or LLDPE film 3 according to Table 2. Material was obtained and similarly evaluated.

<Evaluation method>
[Co-extrusion inflation film formability]
The presence or absence of delamination, cuts, thickness unevenness, and fish eyes in the formed film was visually detected.

[Residual rate of aroma components]
First, the contents of ethyl caproate and isoamyl acetate, which are aromatic components of sake and shochu used in the test, were measured using headspace gas chromatography (HS-GS).
Next, a 10 cm × 10 cm pouch is made using the resulting packaging material, and sake or shochu is filled in the pouch and stored at 25 ° C. for 1 week. The content ratios of ethyl caproate and isoamyl acetate obtained were measured in the same manner, and the residual ratio of each aroma component before storage was calculated.

[Summary of evaluation results]
The low-adsorptive resin films of Examples 1 to 4 exhibited good film formability.
The packaging materials of Examples 5 to 8, which were produced by using the obtained low-adsorptive resin films of Examples 1 to 4 as sealant films, showed a high residual rate of aromatic components, but a general-purpose LLDPE film was used. The packaging material of Comparative Example 1 produced by using it as a sealant film exhibited an inferior residual rate of fragrance components.

1 low adsorptive resin film 2 polyethylene layer 2a polyethylene layer (LDPE)
2b polyethylene layer (LLDPE)
3 Cyclic olefin-based resin-containing layer 3a Cyclic olefin-based resin-containing layer (high cyclic olefin-based resin content)
3b Cyclic olefin resin content layer (low cyclic olefin resin content)
4 Low adsorptive laminate 5 Base material layer 6 Adhesive layer 7 Barrier layer 8 Low adsorptive sealant layer

Claims (13)

A low-adsorptive resin film for packaging, comprising a cyclic olefin-based resin for suppressing adsorption and permeation of ethyl caproate and/or isoamyl acetate,
The low-adsorptive resin film has a cyclic olefin-based resin layer and a polyethylene layer,
The polyethylene layer does not contain a cyclic olefin resin, and comprises a first polyethylene layer made of low-density polyethylene, a second polyethylene layer made of low-density polyethylene, and a third polyethylene layer made of linear low-density polyethylene. become,
The cyclic olefin-based resin layer includes a first cyclic olefin-based resin layer composed of a cyclic olefin-based resin and low-density polyethylene, and a second cyclic olefin-based resin layer including a cyclic olefin-based resin, linear low-density polyethylene, and low-density polyethylene. Consists of an olefin resin layer,
The outermost surface of the low-adsorptive sealant layer, which is the outermost layer of the laminate, contains 15% by mass or more and 60% by mass or less of a cyclic olefin resin, and 30% by mass or more and 80% by mass or less of a linear low-density polyethylene. A layer containing 3% by mass or more and 10% by mass or less of low-density polyethylene ,
The thickness of the cyclic olefin resin layer is 20% or more and 50% or less of the total thickness of the low-adsorptive sealant layer,
The total thickness of the low-adsorptive sealant layer is 20 μm or more and 150 μm or less,
A pouch of 10 cm × 10 cm was prepared using the above low-adsorptive resin film, filled with sake or shochu and stored at 25 ° C. for 1 week. Content of ethyl caproate and isoamyl acetate in the pouch. The content of ethyl caproate is 71.0% or more and the content of isoamyl acetate is 89.9% or more when measured by headspace gas chromatography,
Ethyl caproate and/or isoamyl acetate low adsorption resin film. 2. The low adsorptive resin film according to claim 1, wherein the cyclic olefin resin is a polynorbornene resin. 2. The low-adsorptive resin film according to claim 1, wherein the cyclic olefin resin is a copolymer of a norbornene-based monomer and an alkene monomer. The low-adsorptive resin film according to any one of claims 1 to 3 , wherein the layers constituting the low-adsorptive resin film are layers formed by extrusion or co-extrusion. A low-adsorptive sealant film comprising the low-adsorptive resin film according to any one of claims 1 to 4 . A low-adsorptive laminate having at least a substrate layer and a low-adsorptive sealant layer,
The low-adsorptive sealant layer is a surface layer on one side of the low-adsorptive laminate and is composed of the low-adsorbent sealant film according to claim 5 , and the outermost surface layer, which is the outermost layer of the laminate, is the A low-adsorptive laminate, characterized by being the cyclic olefin-based resin layer. further comprising a barrier layer between the substrate layer and the low-adsorptive sealant layer;
7. The low-adsorptive laminate according to claim 6 , wherein the barrier layer is one or more selected from the group consisting of metal foil, vapor-deposited metal film, and vapor-deposited metal oxide film. 8. The low-adsorptive laminate according to claim 6 or 7 , further comprising a printed layer on the surface of the substrate layer opposite to the low-adsorption sealant layer. The low adsorptive laminate according to any one of claims 6 to 8 , wherein the base material layer has a layer made of paper material. 10. The low adsorption laminate of claim 9 , further comprising a protective layer on the side of said paper material opposite said low adsorption sealant layer. A low-adsorptive packaging material comprising the low-adsorptive laminate according to any one of claims 6 to 10 . 12. A low-adsorptive packaging bag, characterized in that the low-adsorptive sealant layer is formed by using the low-adsorptive packaging material according to claim 11 so as to serve as a content layer. A low-adsorptive packaging material comprising the low-adsorptive laminate according to claim 10 or 11 , wherein the low-adsorptive sealant layer is made into a layer containing the content. Absorbent liquid cartons.

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