JP7255265B2 - Laminated film for deep drawing, bottom material for deep drawing packaging, and deep drawing packaging - Google Patents

Description

TECHNICAL FIELD The present invention relates to a deep-drawn laminated film, a bottom material for a deep-drawn package, and a deep-drawn package that can be suitably used for packaging gauze, cotton swabs, and the like for business use.

In recent years, gauze for business use, cotton swabs, etc. contained in deep-drawn packages are distributed in pharmacies, supermarkets, convenience stores, and the like. Such a deep-drawn package is obtained, for example, as shown in FIG. 1, by joining a bottom material 20 having a recess 30 in the center and a cover material 10 made of high-density polyethylene nonwoven fabric or sterilized paper by heat sealing or the like. It is. Contents 40 such as gauze are accommodated in the recesses 30 of the bottom material 20 .

A coextruded film having a sealant layer and a cohesive failure layer is disclosed as a bottom material for a deep drawn package using a high-density polyethylene nonwoven fabric or sterilized paper as a lid material (Patent Document 1). Also disclosed is a coextruded film that is made into an easy peel layer by using a polyethylene resin and a polypropylene resin or a polybutene resin for the sealant layer. (Patent document 2)

JP 2012-116061 Japanese Patent Application Laid-Open No. 2006-256144

As described above, in the method disclosed in Patent Document 1, the sealing temperature differs greatly depending on whether the high-density polyethylene nonwoven fabric is used for the lid material or when sterilized paper is used. had to use.
On the other hand, in the method disclosed in Patent Document 2, only the lid material of high-density polyethylene nonwoven fabric was actually evaluated in the examples, and the easy peel bottom material that can be used with both nonwoven fabric and sterilized paper It didn't take layers into consideration.

The present invention has been made in view of the above circumstances, and the problems to be solved are that it can be used in a wide sealing temperature range, the easy peel layer can be heat-sealed with the nonwoven fabric, and the nonwoven fabric and the easy peelability To provide a deep-drawn laminated film, a bottom material for a deep-drawn package using the laminated film, and a deep-drawn package using the bottom material.
In the present invention, "nonwoven fabric" includes polyethylene nonwoven fabric and paper nonwoven fabric. Examples of polyethylene nonwoven fabrics include high-density polyethylene nonwoven fabrics (HDPE nonwoven fabrics), and examples of paper nonwoven fabrics include sterilized paper.

As a result of intensive studies in view of the above problems, the present inventors found that a layer containing polyamide (PA), and low-density polyethylene (A) having an MFR of 2.0 g/10 min or more and 0.920 g/cm ³ or less and polybutene resin ( The present inventors have found that the above problems can be solved by using a deep-drawing laminated film having at least two easy peel layers made of a resin composition containing B), and have completed the present invention below.

The first invention includes a layer containing a polyamide resin (PA), and a low-density polyethylene resin (A) having an MFR of 2.0 g/10 min or more and 0.920 g/cm ³ or less and a polybutene resin (B). A laminated film for deep drawing, having at least two easy peel layers made of a resin composition,
In the laminated film for deep drawing, the easy-peel layer can be heat-sealed with the nonwoven fabric and is easily peelable from the nonwoven fabric.

In the first aspect of the present invention, the resin composition of the easy peel layer contains 70 to 97% by mass of a low-density polyethylene resin (A) and 3 to 30% by mass of a polybutene resin (B), based on the resin composition. is preferably included.

In the first invention, the nonwoven fabric is preferably a high density polyethylene (HDPE) nonwoven fabric or sterilized paper.

In the first invention, the easy peel strength between the easy peel layer and the high-density polyethylene (HDPE) nonwoven fabric is preferably 100 gf/15 mm width or more and 700 gf/15 mm width or less.

In the first invention, the easy peel strength between the easy peel layer and the sterile paper is preferably 100 gf/15 mm width or more and 300 gf/15 mm width or less.

In the first invention, it is preferable to have at least one layer containing polypropylene resin (PP) on the side opposite to the easy peel layer side.

In the first invention, between the layer containing the polyamide resin (PA) and the easy peel layer, or between the layer containing the polyamide resin (PA) and the layer containing the polypropylene resin (PP), It is preferable to have at least one layer containing ethylene-vinyl acetate copolymer (EVA) or a layer containing polyethylene resin (PE).

In the first invention, between the layer containing the polyamide resin (PA) and the easy peel layer, or between the layer containing the polyamide resin (PA) and the layer containing the polypropylene resin (PP), It is preferable to have at least one adhesive resin layer.

In the first invention, the total haze according to JIS K 71 36 is preferably 15% or less.

The second aspect of the present invention is a bottom material for a deep-drawn package using the deep-drawn laminated film of the first aspect of the present invention.

The third aspect of the present invention is a deep-drawn package using the bottom material for the deep-drawn package of the second aspect of the present invention, and a high-density polyethylene (HDPE) nonwoven fabric or sterilized paper as a cover material for the deep-drawn package. be.

According to the laminated film for deep drawing of the present invention, it can be used in a wide sealing temperature range, the easy-peel layer can be heat-sealed with the nonwoven fabric, and the film can be easily peeled from the nonwoven fabric. Thus, for example, both high-density polyethylene (HDPE) non-woven fabric and sterile paper can be heat-sealed and exhibit good opening properties.
In addition, since the deep-drawing laminated film of the present invention is excellent in transparency, it is excellent in the visibility of the contents, and the bottom material for deep-drawing packages suitable for packaging gauze, cotton swabs, etc. for business use. and a deep-drawn package can be realized.
In addition, since both HDPE nonwoven fabric and sterilized paper can be used as the lid material, the bottom material can be unified for any lid material, so the type of film can be reduced, the manufacturing cost can be reduced, and deep drawing is possible. Since it becomes possible to provide the package at a lower cost, the industrial utility value is high.

FIG. 1 is a schematic cross-sectional view of a deep-drawn package.

Hereinafter, as an example of embodiments of the present invention, a laminated film for deep drawing (hereinafter sometimes abbreviated as "the film of the present invention" or simply "film"), a bottom material for a deep drawing package, and The deep-drawn package will be described. However, the scope of the present invention is not limited to the embodiments described below.

Deep drawing is forming the bottom material of a container-like deep drawing package using a flat film or the like.
Specifically, a film for the bottom material of a deep-drawn package is heated, fitted into a mold and made into a container shape, and the contents (gauze, food, clothing, etc.) are put into the molded part, and then the lid material is used. A deep-drawn package can be obtained by performing thermo-compression bonding so as to cover with a film or the like. The laminated film for deep drawing of the present invention can be suitably used as a bottom material film for a deep drawn package.

<Laminated film for deep drawing>
The laminated film for deep drawing of the present invention includes a layer containing a polyamide resin (PA), and a low-density polyethylene resin (A) and a polybutene resin (B) having an MFR of 2.0 g/10 min or ^more and 0.920 g/cm ) is required to be a laminated film for deep drawing having at least two easy peel layers made of a resin composition containing

The easy peel layer is preferably located on the innermost layer side. The "innermost layer side" is the side that becomes the content side when the bottom material for deep-drawing packaging is produced using the film of the present invention, and is the side that is heat-sealed with the lid material.

(Layer containing polyamide resin (PA))
In the laminated film for deep drawing of the present invention, at least one layer containing a polyamide resin (PA) (hereinafter sometimes referred to as a PA layer) is added for the purpose of imparting pinhole resistance and deep drawability. It is important to have

The type of polyamide resin that can be used for the PA layer is not particularly limited, but specific examples include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), and polytetramethylene adipamide. (polyamide 46), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), polybis(4-aminocyclohexyl)methandodedecamide (polyamide PACM12), polybis(3-methyl-4-aminocyclohexyl)methandodedecamide (polyamide dimethyl PACM12), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T), polyundecamethylene terephthalamide (polyamide 11T), polyundecamethylene hexahydroterephthalamide (polyamide 11T (H)), polyundecamide (polyamide 11), polydodedecamide (polyamide 12), polytrimethylhexamethylene terephthalamide (polyamide TMDT), polyhexamethylene isophthalamide (polyamide 6I ), polyhexamethylene terephthalate/isophthalamide (polyamide 6T/6I), polymetaxylylene adipamide (polyamide MXD6) and copolymers thereof. Among these, polyamide 6 and polyamide 6-66 (a copolymer of polyamide 6 and polyamide 6,6) are preferably used from the viewpoint of pinhole resistance. When two or more polyamide resin layers are provided, each layer may be composed of a different kind of polyamide resin.

The density of the polyamide resin is preferably 1.0 g/cm ³ or more and 1.2 g/cm ³ or less from the viewpoint of imparting heat resistance and pinhole resistance.

The thickness of the PA layer is preferably at least 5 μm, more preferably 10 μm or more, even more preferably 15 μm or more, from the viewpoint of pinhole resistance and formability. The thickness of the PA layer is preferably 200 µm or less, more preferably 180 µm or less, and even more preferably 150 µm or less. By setting the lower limit of the thickness of the PA layer to 5 μm, good pinhole resistance can be obtained, and by setting the upper limit of the thickness to 200 μm, good thermoformability of the film can be maintained.

(Easy peel (EP) layer)
In the deep-drawing laminated film of the present invention, a predetermined low-density polyethylene resin is used to impart good heat-sealability and unsealability to a wide range of nonwoven fabrics (preferably, high-density polyethylene (HDPE) nonwoven fabric or sterilized paper). It is important to have an easy peel (EP) layer (hereinafter sometimes referred to as EP layer) made of a resin composition containing (A) and polybutene resin (B).

・Low density polyethylene resin (A)
The low-density polyethylene resin (A) in the present invention means LDPE and does not include linear low-density polyethylene.

The melt flow rate (MFR) (JIS K 7210) of the low-density polyethylene resin (A) in the present invention is preferably 2.0 g/10 min or more and 10.0 g/10 min or less, and 3.0 g/10 min or more9. 0 g/10 minutes or less is more preferable. By setting the MFR to 2.0 g/10 minutes or more, it is possible to ensure sufficient adhesion to nonwoven fabrics (eg, HDPE nonwoven fabric, sterilized paper). On the other hand, by setting the MFR to 10.0 g/10 minutes or less, it is possible to suppress tearing of the nonwoven fabric (HDPE nonwoven fabric, sterilized paper) at the time of opening, and improve the dispersibility with the polybutene resin, so the EP layer is transparent. can maintain sexuality.

The density of the low-density polyethylene resin (A) in the present invention is preferably 0.920 g/cm ³ or less, more preferably 0.919 g/cm ³ or less. By setting the density to 0.920 g/cm ³ or less, the cohesive force of the EP layer can be lowered, tearing of the nonwoven fabric can be suppressed, and good openability can be imparted. Although there is no particular lower limit for the density, the density of general low-density polyethylene is preferably 0.910 g/cm ³ or more.

The melting point of the low-density polyethylene resin (A) in the present invention is preferably 70° C. or higher and 125° C. or lower, more preferably 75° C. or higher and 123° C. or lower, even more preferably 80° C. or higher and 120° C. or lower. By setting the melting point to 70° C. or higher, blocking can be suppressed and handleability can be ensured. On the other hand, by setting the melting point to 125° C. or less, heat sealing can be performed in a temperature range in which the HDPE nonwoven fabric does not melt.

The storage elastic modulus G' of the low-density polyethylene resin (A) in the present invention at a frequency of 1 Hz and 140°C is preferably 4 kPa or more and 20 kPa or less, more preferably 5 kPa or more and 18 kPa or less. When the storage elastic modulus G' is 4 kPa or more, it is possible to suppress breakage during opening due to excessive penetration into the nonwoven fabric during heat sealing, and when it is 20 kPa or less, sealability can be imparted.

・Polybutene resin (B)
The melt flow rate (MFR) (JIS K 7210) of the polybutene resin (B) in the present invention is preferably 0.5 g/10 minutes or more and 5.0 g/10 minutes or less, and 1.0 g/10 minutes or more and 4.0 g/10 minutes or more. 10 minutes or less is more preferable. By setting the MFR to 0.5 g/10 min or more, the dispersibility is improved and film-forming properties and transparency can be maintained. Adjustable.

The melting point of the polybutene resin (B) in the present invention is preferably 70° C. or higher and 140° C. or lower, more preferably 75° C. or higher and 135° C. or lower. By setting the melting point to 70° C. or higher, blocking can be suppressed and handleability can be ensured. By setting the melting point to 140° C. or less, insufficient sealing is less likely to occur.

・Composition of EP layer The resin composition constituting the EP layer in the present invention contains 70 to 97% by mass of a low-density polyethylene resin (A) and a polybutene resin (B), based on the total resin composition being 100% by mass. 3 to 30% by mass, more preferably 75 to 95% by mass of the low-density polyethylene resin (A) and 5 to 25% by mass of the polybutene resin (B). When the low-density polyethylene resin (A) is 70% by mass or more, good sealability with the nonwoven fabric can be imparted, and when it is 97% by mass or less, good unsealability can be imparted.

- Thickness of EP layer The thickness of the EP layer is preferably 3 µm or more, more preferably 4 µm or more, still more preferably 5 µm or more, and more preferably 20 µm or less, more preferably from the viewpoint of film-forming properties and peeling appearance. is 15 μm or less, more preferably 10 μm or less. By setting the thickness of the EP layer to 3 μm or more, stable film formability can be obtained. On the other hand, by setting the thickness of the EP layer to 20 μm or less, fluffing and film residue are less likely to occur during peeling, and good peeling appearance can be obtained.

• Easy peel strength The easy peel strength between the EP layer and the high-density polyethylene (HDPE) nonwoven fabric is preferably 100 gf/15 mm width or more and 700 gf/15 mm width or less. By setting it as said range, the balance of easy-opening property and sealing property becomes favorable. The lower limit is more preferably 110 gf/15 mm width or more, more preferably 120 gf/15 mm width or more. The upper limit is preferably 650 gf/15 mm width or less, more preferably 600 gf/15 mm width or less.
The lower limit of the easy peel strength between the EP layer and the sterilized paper is preferably 100 gf/15 mm width or more, as in the case of nonwoven fabric made of high-density polyethylene (HDPE). Therefore, the upper limit of the easy peel strength is preferably 300 gf/15 mm width or less. By setting it as said range, the balance of easy-opening property and sealing property becomes favorable. The lower limit is more preferably 110 gf/15 mm width or more, more preferably 120 gf/15 mm width or more. The upper limit is more preferably 290 gf/15 mm width or less, and even more preferably 280 gf/15 mm width or less.
The easy peel strength was measured by cutting the sealed portion of the deep drawn package formed of the film of the present invention into strips of 15 mm width, and peeling off the lid material and the bottom material at a speed of 200 mm / min using a tensile tester. It can be obtained from the maximum load when

In the film of the present invention, the EP layer can be heat-sealed with the nonwoven fabric over a wide temperature range and has easy peelability. From the viewpoint of the heat resistance of the nonwoven fabric, the preferred heat-sealing temperature differs between, for example, a nonwoven fabric made of polyethylene and a nonwoven fabric made of sterilized paper. It can exhibit heat-sealability and easy-openability for a wide range of nonwoven fabrics.
Preferred heat sealing temperatures are 110°C to 140°C for HDPE nonwovens and 130°C to 180°C for sterile paper, but the EP layers of the present invention can be It can exhibit heat sealability and easy openability.

(outer layer)
In the film of the present invention, an outer layer may be further provided on the side of the PA layer opposite to the side on which the easy peel layer is formed.
Here, the outer layer may be one layer or multiple layers.

The film of the present invention preferably has a layer containing a polypropylene resin (hereinafter sometimes referred to as a PP layer) as an outer layer for the purpose of imparting hardness. The type of PP used in the PP layer is not particularly limited, and examples include random copolymers, block copolymers, homopolymers or mixtures thereof. Among them, it is preferable to use a random copolymer from the viewpoint of deep drawability.

(middle layer)
In the film of the present invention, an intermediate layer can be provided between the PA layer and the EP layer, or between the PA layer and the outer layer, or between both. Each intermediate layer may be one layer, or may be multiple layers.
As the intermediate layer, a layer containing an ethylene-vinyl acetate copolymer (hereinafter sometimes referred to as an EVA layer) or a layer containing a polyethylene resin (hereinafter referred to as a PE layer) is used for the purpose of imparting flexibility. ) can be arranged. On the other hand, in addition to the outer layer, a PP layer can be arranged in the intermediate layer for the purpose of imparting hardness. As the PP layer, the same material as in the outer layer can be used.

Although the ethylene content of EVA used in the EVA layer is not particularly limited, it is preferably 1 mol% or more, more preferably 1.5 mol% or more, and preferably 20 mol% or more from the viewpoint of film formation stability. mol % or less, more preferably 15 mol % or less. When an EVA layer is provided, the thickness of the EVA layer is preferably 10 μm or more, more preferably 20 μm or more, and still more preferably 25 μm or more, from the viewpoint of film-forming properties, and the upper limit is preferably 100 μm or less, more preferably 80 μm or less. More preferably, it is 60 μm or less.

When a PE layer is provided as an intermediate layer, the PE used in the PE layer is not particularly limited, and examples include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene ( HDPE) or a mixture of LDPE and HDPE can be used. The mixing ratio in the mixture of LDPE and HDPE can be appropriately determined for the purpose of imparting the desired flexibility. can be 50-80:50-20, more preferably 60-80:40-20.

LDPE or LLDPE preferably has a density of 0.90 g/cm ³ or more, and HDPE preferably has a density of 0.94 g/cm ³ or more. By using a material with a high density, it is possible to impart appropriate hardness to the PE layer while maintaining its flexibility. When a PE layer is provided, the thickness of the PE layer is preferably 10 μm or more, more preferably 20 μm or more, and still more preferably 25 μm or more, and the upper limit is preferably 100 μm or less, more preferably 80 μm or less, and further preferably 60 μm or less. is.

(Adhesive resin layer)
The film of the present invention can be provided with an adhesive resin layer for bonding each layer. The adhesive resin used in the adhesive resin layer is not particularly limited as long as it can adhere the PA layer, the intermediate layer (e.g., PE layer), and the outer layer (e.g., PP layer) with the required strength. A polyolefin resin modified with a derivative thereof can be preferably used. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid and citraconic acid. Esters and anhydrides of the above unsaturated carboxylic acids can also be used as adhesive resins, and derivatives such as methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl methacrylate, and glycidyl acrylate. , glycidyl methacrylate, acrylamide, methacrylamide, sodium acrylate, and vinyl acetate. Commercially available adhesive resins include Admer (trade name) manufactured by Mitsui Chemicals, Inc., and Modic (trade name) manufactured by Mitsubishi Chemical Corporation, and these can be preferably used. The density of the adhesive resin is preferably 0.85 g/cm ³ or more and 0.95 g/cm ³ or less from the viewpoint of imparting heat resistance and adhesion.

The adhesive resin layer is preferably provided between the PA layer and the EP layer, between the PA layer and an outer layer (for example, a PP layer), or between both, from the viewpoint of further increasing the interlayer adhesive strength. . Specifically, it is provided between the PA layer and the EP layer, between the PA layer and the PE layer, between the PA layer and the EVA layer, between the PA layer and the PP layer, or a plurality of layers therebetween. is preferred.

The thickness of the adhesive resin layer is not particularly limited as long as each layer can be bonded with the required adhesive strength, but is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, preferably 20 μm or less, more preferably 15 μm. 10 μm or less, and more preferably 10 μm or less.

(Layer structure)
The film of the present invention may have at least two layers, a PA layer and an EP layer, and other layer structures are not particularly limited.
For example, when represented by a PA layer (PA), a PE layer (PE), an EVA layer (EVA), a PP layer (PP), an EP layer (EP) and an adhesive resin layer (AD), the following layer structure is formed. be able to. Among them, preferred layer structures are the following (1), (3), (5) or (7), and the most preferred layer structure is (1) or (5).

(1) PA/AD/EP
(2) PA/AD/PE/EP
(3) PA/AD/EVA/EP
(4) PP/AD/PA/AD/EP
(5) PP/AD/PA/AD/PE/EP
(6) PP/AD/PA/AD/EVA/EP
(7) PA/AD/PA/AD/EP
(8) PA/AD/PA/AD/PE/EP
(9) PA/AD/PA/AD/EVA/EP
(10) PP/PA/AD/PA/AD/EP
(11) PP/PA/AD/PA/AD/PE/EP
(12) PP/PA/AD/PA/AD/EVA/EP

The film of the present invention can be produced by laminating the above layers simultaneously or sequentially.

(haze)
The total haze of the film of the present invention at a thickness of 80 µm is preferably 15% or less, more preferably 12% or less, from the viewpoint of content visibility.

The total haze of the film of the present invention (thickness: 80 µm) after deep drawing (drawing depth: 15 mm) is preferably 30% or less, more preferably 27% or less, from the viewpoint of content visibility.

<Manufacturing method of laminated film for deep drawing>
The film of the present invention can be produced using a known method such as an extrusion lamination method, a co-extrusion inflation method, a co-extrusion T-die method and the like. For example, the resin used for each layer may be formed into a film by each extrusion method, and then a laminated film may be formed by a lamination method, or melt extrusion may be performed using different extruders, and a laminated film may be formed by a coextrusion method using a multilayer die. may be In particular, it is preferable to use the co-extrusion T-die method because the film can be formed at once even if the number of layers of the film is large, and the thickness control as a laminated film is relatively easy.

In addition, each layer contains various additives such as inorganic fillers, organic fillers, antioxidants, weather stabilizers, light stabilizers, anti-blocking agents, lubricants, nucleating agents, and pigments within the range that does not impair the characteristics of each layer. It's okay to be.

(non-woven fabric)
The film of the present invention can be heat-sealed with a nonwoven fabric over a wide temperature range, and is easily peelable from the nonwoven fabric. Nonwoven fabrics include polyethylene nonwoven fabrics and paper nonwoven fabrics (sterilized paper).
The PE that constitutes the polyethylene nonwoven fabric can be heat-sealed with the EP layer, and when the nonwoven fabric is formed, it can exhibit air permeability and the property of preventing fungi from entering the container (antibacterial property). If there is, it is not particularly limited. As such PE, various types of PE such as high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (LLDPE) can be used. is preferred. When the polyethylene nonwoven fabric is formed into a deep-drawn package, it preferably has small pores to the extent that it can exhibit air permeability and antibacterial properties. It is desirable that the nonwoven fabric has a basis weight of 10 g/m ² or more and 500 g/m ² or less.

Commercially available polyethylene nonwoven fabrics can be used, and specific examples include Tyvek manufactured by Asahi-DuPont Flashspun Products.

Moreover, the sterilized paper is not particularly limited as long as it can exhibit air permeability and antibacterial properties. Such sterilized paper is preferably sterilized paper having a basis weight of 40 g/m ² or more and 300 g/m ² or less.

Commercially available sterilized paper can be used, and specific examples include MEP-P, MEP-EX, MEP-G manufactured by KJ Specialty Paper Co., Ltd., and Medica J manufactured by Oji F-Tech.

<Bottom material for deep-drawn package, deep-drawn package>
The film of the present invention can be used as a deep-drawn package by filling a content such as gauze after deep-drawing, covering it with a lid material film, and heat-sealing. Particularly when the film of the present invention is used as a bottom material for deep-drawn packages, a good deep-drawn package can be obtained.

When used as a bottom material for a deep-drawn package, for example, after the film of the present invention is formed into a desired shape and size with a deep-drawn mold (film supply step and film forming step), gauze, cotton swabs, etc. (contents filling step), further sealed with a lid material film (lid material film supply step and sealing step), vacuum packaged (vacuum packaging step), and cooled (cooling step) , by cutting (cutting step), a deep-drawn package can be produced.

The lid material for the deep draw package of the present invention is desirably breathable when the package is sterilized together with ethylene oxide gas (EOG). From such a point of view, polyethylene (especially HDPE) nonwoven fabric or sterilized paper is preferably used as the lid material for the deep-drawn package of the present invention.

The deep-drawn package of the present invention can be produced by adhering the lid material and the bottom material of the present invention by adhesive means such as heat sealing.

Examples of the present invention are shown below, but the present invention is not limited to these. The sample preparation method and evaluation method in the present invention are as follows.

<Preparation of pack sample (deep drawing package)>
The film prepared below was deep-drawn into a shape of 160 mm long, 120 mm wide, and 15 mm deep by a deep drawing packaging machine (R530 manufactured by Multivac), covered with a lid material, and frame-sealed. For the cover material, high-density polyethylene nonwoven fabric (Tyvek 2FS, manufactured by Asahi DuPont Flashspun Products) and sterilized paper (MEP-70P, manufactured by KJ Specialty Paper Co., Ltd.) were used.

<Easy peel strength>
The seal part of the pack sample was cut into strips with a width of 15 mm in the film flow direction, and the maximum load when the lid material and the bottom material were peeled off at a speed of 200 mm/min with a tensile tester was taken as the easy peel strength.

<Openability>
When the prepared pack sample was peeled off by hand, the openability was evaluated according to the following criteria.
○: The lid material is not broken △: The lid material is not broken, but fluffing is observed, but within the practical range ×: The lid material is torn

<Total Haze>
A flat film (thickness: 80 μm) before molding and a film after deep drawing (drawing depth: 15 mm) were measured for total haze according to JIS K 71 36 , and the following criteria were used. evaluated.
Film in flat state before molding ○: 15% or less ×: greater than 15% Film after deep drawing ○: 30% or less ×: greater than 30%

<Raw materials used>
Low-density polyethylene (LDPE A-1): manufactured by Ube Maruzen Polyethylene Co., Ltd., melting point 106° C., MFR 7.5 g/10 min, density 0.918 g/cm ³ , storage modulus G′ (140° C.) 10.9 kPa
Low-density polyethylene (LDPE A-2): manufactured by Nippon Polyethylene Co., Ltd., melting point 110°C, MFR 2.2 g/10 minutes, density 0.923 g/cm ³ , storage modulus G' (140°C) 21.0 kPa
Linear low-density polyethylene (LLDPE-1): Prime Polymer Co., Ltd., melting point 98°C, MFR 10.0 g/10 minutes, density 0.911 g/cm ³ , storage modulus G' (140°C) 3.8 kPa
Linear low-density polyethylene (LLDPE-2): manufactured by Ube Maruzen Polyethylene, melting point 117°C, MFR 5.0 g/10 minutes, density 0.919 g/cm ³ , storage modulus G' (140°C) 4.8 kPa
Polybutene resin (PB(B): Mitsui Chemicals, Inc., melting point 112°C, MFR 1.8 g/10 min, density 0.915 g/cm ³ , storage modulus G' (140°C) 26 kPa
Polyamide resin (PA): manufactured by DSM, polyamide 6, density 1.13 g/cm ³
Polypropylene resin (PP): manufactured by Nippon Polypropylene, density 0.900 g/cm ³
Adhesive resin (AD1): manufactured by Mitsui Chemicals, density 0.890 g/cm ³
Adhesive resin (AD2): manufactured by Mitsui Chemicals, density 0.910 g/cm ³
Linear low-density polyethylene (LLDPE-3): manufactured by Prime Polymer Co., Ltd., melting point 118°C, MFR 1.9 g/10 minutes, density 0.920 g/cm ³

<Formation of laminated film for deep drawing>
(Example 1)
92% by mass of LDPE A-1 and 8% by mass of PB (B) were dry-blended and blended for the easy peel layer 1 (EP1). The resins of each layer were co-extruded by inflation method using a single screw extruder to obtain a laminated film for deep drawing as a non-stretched film having a total thickness of 80 μm. The layer structure of the laminated film for deep drawing is as follows.
PP (10.4 μm) / AD1 (6.4 μm) / PA (20 μm) / AD2 (6.4 μm) / LLDPE-3 (28.8 μm) / EP1 (8 μm)
Table 1 shows the evaluation results of the obtained film.

(Example 2)
A laminated film for deep drawing was produced and evaluated in the same manner as in Example 1 except that EP1 in Example 1 was changed to EP2 containing 85% by mass of LDPE A-1 and 15% by mass of PB (B). bottom. The results are shown in Table 1 below.

(Example 3)
A laminated film for deep drawing was produced and evaluated in the same manner as in Example 1 except that EP1 in Example 1 was changed to EP3 containing 80% by mass of LDPE A-1 and 20% by mass of PB (B). bottom. The results are shown in Table 1 below.

(Comparative example 1)
A laminated film for deep drawing was produced and evaluated in the same manner as in Example 1 except that EP1 in Example 1 was replaced with EP4 containing 92% by mass of LDPE A-2 and 8% by mass of PB (B). bottom. The results are shown in Table 1 below.

(Comparative example 2)
A laminated film for deep drawing was produced and evaluated in the same manner as in Example 1 except that EP1 in Example 1 was changed to EP5 containing 50% by mass of LLDPE-1 and 50% by mass of PB (B). . The results are shown in Table 1 below.

(Comparative Example 3)
A laminated film for deep drawing was produced and evaluated in the same manner as in Example 1 except that EP1 in Example 1 was changed to EP6 using 100% by mass of LDPE A-1. The results are shown in Table 1 below.

(Comparative Example 4)
A laminated film for deep drawing was produced and evaluated in the same manner as in Example 1 except that EP1 in Example 1 was changed to EP7 containing 90% by mass of LLDPE-2 and 10% by mass of PB (B). . The results are shown in Table 1 below.

In Examples 1, 2, and 3, the easy peel strength was within a predetermined range for each of the HDPE nonwoven fabric and the sterilized paper, and the unsealability and transparency were good.
In Comparative Example 1, the low-density polyethylene used in the EP layer had a high density and a high storage elastic modulus G' (140°C), so the peel strength at a low sealing temperature was weak. Moreover, when the temperature is raised, the HDPE nonwoven fabric is torn at the time of peeling. In Comparative Examples 2 and 4, the storage elastic modulus G' (140°C) of the linear low-density polyethylene used in the EP layer was low, and the sterilized paper was torn during peeling. In Comparative Example 2, a large amount of polybutene was used in the EP layer to adjust the sealing strength, so the peel strength at a low sealing temperature was weak and the transparency decreased. In Comparative Example 3, since the EP layer did not contain polybutene, the EP layer was completely sealed, and the HDPE nonwoven fabric was torn at the time of peeling, and easy peelability was not observed.

The easy-peel layer in the film of the present invention can be heat-sealed with a high-density polyethylene (HDPE) nonwoven fabric or sterilized paper, and has good openability. Moreover, the film of the present invention is excellent in transparency. Therefore, the bottom material formed by deep-drawing the film of the present invention, and the deep-drawn packaging body in which the bottom material is combined with a high-density polyethylene (HDPE) nonwoven fabric or sterilized paper as a lid material are suitable for commercial use. It can be suitably used as a package for gauze, cotton swabs and the like.

10: Lid Material 20: Bottom Material 30: Recess 40: Contents

Claims (10)

A laminated film for deep drawing, having at least two layers, a layer containing a polyamide resin (PA) and an easy peel layer made of a resin composition containing a low-density polyethylene resin (A) and a polybutene resin (B), ,
The low-density polyethylene resin (A) has an MFR of 2.0 g/10 minutes or more, a density of 0.920 g/cm ³ or less, and a storage elastic modulus G' of 4 kPa or more and 20 kPa or less at a frequency of 1 Hz and 140°C,
The measurement of the MFR is performed at a temperature of 190 ° C. and a load of 2.16 kg based on JIS K 7210,
The easy peel layer contains 70 to 97% by mass of the low density polyethylene resin (A) and 3 to 30% by mass of the polybutene resin (B) based on the resin composition,
A laminated film for deep drawing, wherein the easy-peel layer is heat-sealable with a nonwoven fabric and easily peelable from the nonwoven fabric. 2. The deep draw laminated film according to claim 1, wherein the non-woven fabric is high density polyethylene (HDPE) non-woven fabric or sterilized paper. 3. The deep-drawing laminated film according to claim 1, wherein the easy peel strength between the easy peel layer and the high-density polyethylene (HDPE) nonwoven fabric is 100 gf/15 mm width or more and 700 gf/15 mm width or less. 3. The deep drawing laminated film according to claim 1, wherein the easy peel strength between the easy peel layer and the sterilized paper is 100 gf/15 mm width or more and 300 gf/15 mm width or less. The laminated film for deep drawing according to any one of claims 1 to 4, which has at least one layer containing polypropylene resin (PP) on the side opposite to the easy peel layer side. Between the layer containing the polyamide resin (PA) and the easy peel layer, or between the layer containing the polyamide resin (PA) and the layer containing the polypropylene resin (PP), at least one layer of ethylene-acetic acid 6. The deep-drawing laminated film according to claim 5 , which has a layer containing a vinyl copolymer (EVA) or a layer containing a polyethylene resin (PE). At least one adhesive resin layer between the layer containing the polyamide resin (PA) and the easy peel layer, or between the layer containing the polyamide resin (PA) and the layer containing the polypropylene resin (PP) The laminated film for deep drawing according to claim 5 or 6 , having The laminated film for deep drawing according to any one of claims 1 to 7, which has a total haze of 15% or less according to JIS K 7136. A bottom material for a deep-drawn package using the deep-drawn laminated film according to any one of claims 1 to 8. A deep-drawn package using the bottom material for a deep-drawn package according to claim 9 and the nonwoven fabric as a cover material .

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