JP7060029B2 - Package - Google Patents

Description

The present invention relates to multilayer films and packages.
This application claims priority based on Japanese Patent Application No. 2017-193593 filed in Japan on October 3, 2017, the contents of which are incorporated herein by reference.

In recent years, as a medical package, a deep-drawn package (hereinafter, also referred to as "deep-draw package") has been used. In the deeply squeezed package, the bottom material made of a multilayer film having a recess formed in the center and the lid material made of polyethylene non-woven fabric, sterile paper, etc. (hereinafter, also referred to as "PE non-woven fabric, etc.") are heat-sealed. It is joined by such as. Commercial gauze, cotton swabs, medical instruments, etc. are housed in the above-mentioned recesses.

Conventionally, as a bottom material used for a medical packaging body, a multilayer film obtained by laminating (laminating method) a polyester film or a nylon film and a heat-sealable resin film is widely and generally used. On the other hand, as the lid material, a polyethylene non-woven fabric or sterilized paper is used as described above from the viewpoint of air permeability of the sterilized gas in the sterility process.

By the way, the medical packaging is required to be easy to open depending on the mode of use. Further, as the lid material of the medical packaging body, a polyethylene non-woven fabric is selected from the viewpoint of placing importance on hygiene. Polyethylene non-woven fabric coated with an adhesive to give easy-opening property is expensive, and gas permeability is also lowered. Therefore, the easy-release function is imparted to the multilayer film side to be sealed with the polyethylene non-woven fabric. .. In order to impart easy-opening properties to medical packaging, a structure in which an easily peelable resin layer (hereinafter, also referred to as "easy peel layer") is provided on the sealing side with a PE non-woven fabric or the like as a multilayer film used as a bottom material. It is known (Patent Document 1). Further, a coextruded multilayer film for deep drawing molding having a polyamide resin, a non-woven fabric made of polyethylene at 135 ° C. or lower, a seal layer capable of heat-sealing with sterilized paper, and an easy peel layer having delamination property with the seal layer is known. (Patent Document 2).

Japanese Unexamined Patent Publication No. 2014-162162 Japanese Unexamined Patent Publication No. 2014-19006

However, the reality is that multilayer films used for medical packaging and the like are required to be capable of heat-sealing with polyethylene non-woven fabrics in a wider temperature range.

The present invention has been made in view of the above circumstances, and provides a multilayer film and a package that can be heat-sealed with a polyethylene non-woven fabric in a wide temperature range of 135 ° C. or lower and has good peelability. That is the issue.

In order to achieve the above object, the present invention has adopted the following configuration.
[ 1 ] A sealant layer provided so as to be a surface layer and a base material layer provided adjacent to the sealant layer and containing a polyethylene-based resin are provided at least.
The sealant layer contains a first resin having a melting point of at least 80 to 110 ° C. and a second resin having a melting point of 130 to 200 ° C.
The first resin contains an ethylene-vinyl acetate copolymer and contains
The second resin contains homopolypropylene and contains
With a multilayer film capable of heat-sealing with polyethylene non-woven fabric at 110 ° C.
With polyethylene non-woven fabric,
A package in which at least a part of the sealant layer of the multilayer film is heat-sealed on the surface of the nonwoven fabric.
[2] The package according to [1], wherein the content of the first resin in the sealant layer is 50 to 99% by mass, and the content of the second resin is 1 to 50% by mass.
[3] The package according to [1] or [2], wherein the base material layer contains a high-density polyethylene resin.
[4] The package according to any one of [1] to [3], wherein the ratio of the thickness of the sealant layer to the base material layer is in the range of 1: 0.5 to 1:10.
[ 5 ] The package according to any one of [1] to [4], wherein the peel strength between the multilayer film and the nonwoven fabric is 120 to 770 (g / 25 mm).

As described above, in the multilayer film of the present invention, the sealant layer provided so as to be a surface layer has a first resin having a melting point of 80 to 110 ° C. and a second resin having a melting point of 130 to 200 ° C. Since it has a structure including and, it can be heat-sealed with a polyethylene non-woven fabric in a wide temperature range of 135 ° C. or lower, and has good peelability.

Since the package of the present invention is configured to include the multilayer film of the present invention, it has desired easy peelability with respect to a polyethylene non-woven fabric.

It is sectional drawing of the multilayer film 1 which is one Embodiment to which this invention is applied. It is sectional drawing of the multilayer film 1 which is one Embodiment to which this invention is applied.

Hereinafter, a multilayer film and a package to which the present invention is applied will be described in detail. In the drawings used in the following description, in order to make the features easy to understand, the featured parts may be enlarged for convenience, and the dimensional ratios of the respective components may not be the same as the actual ones.

<Multilayer film>
First, a configuration of a multilayer film according to an embodiment to which the present invention is applied will be described. FIG. 2 is a schematic cross-sectional view of a multilayer film 1 according to an embodiment to which the present invention is applied. As shown in FIG. 1, the multilayer film 1 of the present embodiment is roughly configured by including a sealant layer 2 provided as a surface layer and a base material layer 3 provided adjacent to the sealant layer 2. ing. Further, as shown in FIG. 2, the multilayer film 1 of the present embodiment has a sealant layer 2 provided as a surface layer, a base material layer 3 provided adjacent to the sealant layer 2, and a base material layer 3. It may be roughly configured with another resin layer laminated on the top. The multilayer film 1 of the present embodiment can be used as a film for a bottom material of a package, particularly a medical package.

(Sealant layer)
The sealant layer 2 is a resin layer provided for joining with a non-woven fabric or the like to be joined by heat sealing and for imparting easy-opening property. The sealant layer 2 contains a first resin having a melting point of 80 to 110 ° C., preferably 85 to 105 ° C., more preferably 85 to 100 ° C., and 130 to 200 ° C., preferably 140 to 170 ° C., more preferably. It contains a second resin having a melting point of 150 to 165 ° C. When the melting point of the first resin is equal to or higher than the lower limit of the above range, it does not become sticky even in a high temperature environment such as summer, and in the range of 105 to 135 ° C., it is heat-sealed with a polyethylene non-woven fabric and an appropriate peel strength. Is possible. On the other hand, if it is not more than the upper limit of the above range, the polyethylene nonwoven fabric can be sealed without melting during heat sealing.
Further, when the melting point of the second resin is at least the lower limit of the above range, softening of the second resin is suppressed at the time of sealing and the peel strength is stable, and when it is at least the upper limit of the above range, for example, a polyethylene non-woven fabric After joining, it is possible to prevent the fibers of the polyethylene non-woven fabric from tearing when peeling off.

The first resin that can be used for the sealant layer 2 is not particularly limited as long as it is a resin having the above melting point, and examples thereof include polyethylene-based resins.

Examples of the polyethylene-based resin include a homopolymer of ethylene such as low-density polyethylene (LDPE) resin, linear low-density polyethylene (LLDPE) resin, medium-density polyethylene (MDPE) resin, and high-density polyethylene (HDPE) resin; Ethylene-vinyl acetate copolymer (EVA) resin, ethylene-methylmethacrylate copolymer (EMMA) resin, ethylene-ethylacrylate copolymer (EEA) resin, ethylene-methylacrylate copolymer (EMA) resin, ethylene- Ethylene-based copolymers such as ethyl acrylate-maleic anhydride copolymer (E-EA-MAH) resin, ethylene-acrylate copolymer (EAA) resin, ethylene-methacrylic acid copolymer (EMAA) resin; ionomer (ION) Resin or the like is used alone or in combination of two or more.

The polyethylene-based resin preferably contains an ethylene homopolymer or an ethylene-based copolymer, and may contain both of them. The polyethylene-based resin is more preferably an ethylene homopolymer or an ethylene-based copolymer, and may be both of them.
The ethylene-based copolymer preferably contains an ethylene-vinyl acetate copolymer or an ethylene-acrylate copolymer, more preferably contains an ethylene-vinyl acetate copolymer, and is preferably an ethylene-vinyl acetate copolymer. More preferred.

The second resin that can be used for the sealant layer 2 is not particularly limited as long as it is a resin having the above melting point, and examples thereof include a resin such as polypropylene (PP) or polybutene (PB).

As polypropylene, homopolymers, random copolymers, block copolymers and the like are used alone or in admixture of two or more, and it is particularly preferable to use homo-PP polymers.

The content of the first resin constituting the sealant layer 2 is preferably 50 to 99% by mass, more preferably 65 to 95% by mass, and even more preferably 75 to 95% by mass.
Here, the content of the first resin constituting the sealant layer 2 means the content of the first resin component with respect to the total mass (100% by mass) of all the components constituting the sealant layer 2.

The content of the second resin constituting the sealant layer 2 is preferably 1 to 50% by mass, more preferably 5 to 35% by mass, and even more preferably 5 to 25% by mass.
Here, the content of the second resin constituting the sealant layer 2 means the content of the second resin component with respect to the total mass (100% by mass) of all the components constituting the sealant layer 2.

The sealant layer 2 may contain an additive from the viewpoint of improving the low temperature heat sealability. Examples of the additive include terpene-based resins (Yasuhara Chemical, "Hirodyne series") and the like.

The thickness of the sealant layer 2 is preferably 3 to 70 μm, more preferably 5 to 45 μm. When the above thickness is at least the lower limit of the preferable range, a predetermined peel strength is obtained when heat-sealed with the polyethylene non-woven fabric, and when it is at least the upper limit, the effect of easy opening is obtained at the time of opening. Be done.

(Base layer)
The base material layer (also referred to as a core layer) 3 is a resin layer provided adjacent to the above-mentioned sealant layer 2. The base material layer 3 can impart flexibility to the multilayer film 1. The resin that can be used for the base material layer 3 is not particularly limited as long as it is a resin that can impart the above functions, and examples thereof include polyethylene-based resins.

Examples of the polyethylene-based resin include a homopolymer of ethylene such as low-density polyethylene (LDPE) resin, linear low-density polyethylene (LLDPE) resin, medium-density polyethylene (MDPE) resin, and high-density polyethylene (HDPE) resin; Ethylene-vinyl acetate copolymer (EVA) resin, ethylene-methylmethacrylate copolymer (EMMA) resin, ethylene-ethylacrylate copolymer (EEA) resin, ethylene-methylacrylate copolymer (EMA) resin, ethylene- Ethylene-based copolymers such as ethyl acrylate-maleic anhydride copolymer (E-EA-MAH) resin, ethylene-acrylate copolymer (EAA) resin, ethylene-methacrylic acid copolymer (EMAA) resin; ionomer (ION) Resin or the like is used alone or in combination of two or more.
As the polyethylene resin, the above MDPE or HDPE is preferable, and HDPE is more preferable. By using the base material layer 3 containing HDPE, stable heat peel strength can be obtained.

The base material layer 3 may be only one layer, or may be a plurality of two or more layers as shown in FIG. For example, by making the base material layer 3 composed of a plurality of layers of different materials, characteristics such as hardness of the base material layer 3 can be adjusted. Examples of the base material layer having two or more layers include a base material layer having two layers of HDPE and LLDPE.

The thickness of the base material layer 3 is preferably 15 to 150 μm, more preferably 30 to 100 μm. When the thickness is not less than the lower limit of the preferable range, flexibility is obtained, and when it is not more than the upper limit, stable peel strength can be obtained.

In the multilayer film 1 of the present embodiment, the thickness ratio of the sealant layer 2 and the base material layer 3 described above is preferably in the range of 1: 0.5 to 1:10, preferably 1: 0.5 to 1. The range of: 7 is more preferable, and the range of 1: 1 to 1: 5 is more preferable. When the above-mentioned ratio is at least the lower limit value in the above preferable range, the effect of preventing curling of the package is obtained, and when it is at least the upper limit value, stable peel strength can be obtained.

In addition to the sealant layer 2 and the base material layer 3 described above, the multilayer film 1 of the present embodiment may include other resin layers as long as the effects of the present invention are not impaired. In the multilayer film 1 shown in FIG. 2, an adhesive resin layer 4 and a pinhole-resistant layer 5 are laminated on a base material layer 3 as another resin layer.

(Adhesive resin layer)
The adhesive resin layer 4 is a resin layer provided for increasing the interlayer strength of each resin layer constituting the multilayer film 1 other than the layers between the sealant layer 2 and the base material layer 3 described above.

As the adhesive resin applicable to the adhesive resin layer 4, a known adhesive olefin resin, for example, an adhesive polypropylene resin, an adhesive polyethylene resin, or the like is used. It may contain an antioxidant to prevent oxidation. As the antioxidant, a known antioxidant, for example, a hindered phenol-based antioxidant, a phosphorus-based antioxidant, a thioether-based antioxidant, or the like is used alone or in combination of two or more. Further, from the viewpoint of improving adhesiveness and mechanical properties, cellulose nanofibers may be contained.

The thickness of the adhesive resin layer 4 is not particularly limited as long as each layer can be bonded with a required adhesive strength, but is preferably 2 to 30 μm, more preferably 5 to 25 μm.

(Pinhole resistant layer)
The pinhole-resistant layer 5 is a resin layer provided to impart pinhole resistance to the multilayer film 1. The pinhole-resistant layer 5 preferably contains a polyamide resin from the viewpoint of improving pinhole resistance. Examples of the polyamide resin contained in the pinhole resistant layer 5 include 4-nylon, 6-nylon, 7-nylon, 11-nylon, 12-nylon, 46-nylon, 66-nylon, 69-nylon and 610-nylon. , 611-Nylon, 612-Nylon, 6T-Nylon, 6I Nylon, 6-Nylon and 66-Nylon Copolymer (Nylon 6/66), 6-Nylon and 610-Nylon Copolymer, 6-Nylon and 611-Nylon Copolymer, 6-nylon and 12-nylon copolymer (nylon 6/12), 6-nylon and 612 nylon copolymer, 6-nylon and 6T-nylon copolymer, 6-nylon and 6I-nylon copolymer, 6-nylon And 66-nylon and 610-nylon copolymer, 6-nylon and 66-nylon and 12-nylon copolymer (nylon 6/66/12), 6-nylon and 66-nylon and 612-nylon copolymer, 66-nylon And 6T-nylon copolymer, 66-nylon and 6I-nylon copolymer, 6T-nylon and 6I-nylon copolymer, 66-nylon and 6T-nylon and 6I-nylon copolymer, amorphous nylon and the like. .. Among them, 6-nylon, 12-nylon, 66-nylon, nylon 6/66, nylon 6/12, nylon 6/66/12 and the like are preferable from the viewpoint of heat resistance, mechanical strength, and availability. , 6-Nylon is more preferred.

The total thickness of the pinhole-resistant layer 5 is not particularly limited, but is preferably 10 to 90 μm, more preferably 12 to 50 μm.

(Additive)
In the multilayer film 1 of the present embodiment, known lubricants and additives are appropriately added to the sealant layer 2 and the base material layer 3 described above for the purpose of preventing slipperiness and blocking and imparting antifogness, if necessary. It may be given. For the purpose of slipperiness and prevention of blocking, organic lubricants such as oleic acid amide and erucic acid amide, and inorganic lubricants such as silica, zeolite and calcium carbonate can be mentioned. Further, in order to impart anti-fog property, a already known surfactant or the like can be appropriately used.

<Manufacturing method of multilayer film>
Next, an example of the above-mentioned manufacturing method of the multilayer film 1 will be described.
The method for producing the multilayer film 1 described above is not particularly limited, but is a coextrusion T-die method such as a feed block method or a multi-manifold method in which a resin or the like as a raw material is melt-extruded by several extruders. Examples thereof include an air-cooled or water-cooled coextrusion inflation method and a laminating method. Among these, the method of forming a film by the coextrusion T-die method is particularly preferable because it is excellent in controlling the thickness of each layer.

As the laminating method, a dry laminating method, an extrusion laminating method, a hot melt laminating method, a wet laminating method, a thermal (heat) laminating method, etc., in which a single-layer sheet or film forming each layer is bonded together using an appropriate adhesive, etc. And those methods can be used in combination. Further, it may be laminated by a coating method.

<Packaging>
Next, an example of a package using the above-mentioned multilayer film 1 will be described.
The package of the present embodiment includes the above-mentioned multilayer film and a polyethylene non-woven fabric, and at least a part of the sealant layer of the multilayer film is heat-sealed on the surface of the nonwoven fabric.
Since the package of the present invention is configured to include the multilayer film of the present invention which can be heat-sealed with a polyethylene non-woven fabric and has good easy peelability, the desired easy peelability with respect to the polyethylene non-woven fabric is provided. Has.

The polyethylene non-woven fabric applicable to the package of the present embodiment has characteristics that can be heat-sealed with a sealant layer, and that when the non-woven fabric is formed, it has breathability and prevents fungi from entering the container (prevention). It is not particularly limited as long as it can exhibit (bacterial). Examples of polyethylene (PE) constituting such a non-woven fabric include HDPE, LDPE, LLDPE and the like. Among these, it is preferable to use HDPE from the viewpoint of strength and heat sealability.

When the package of the present embodiment is used as a medical package, the polyethylene non-woven fabric preferably has small holes to the extent that it can exhibit breathability and antibacterial properties. Specifically, it is preferable that the non-woven fabric is composed of fibers in the range of 0.0001 to 20 dtex and has a basis weight of 10 to 300 g / m ² .

The package of the present embodiment can be used as a deep-drawn package by deep-drawing the bottom material, filling it with contents such as gauze, covering it with a lid material, and heat-sealing it. In particular, when the above-mentioned multilayer film is used as the bottom material of the deep-drawn package and the polyethylene non-woven fabric is used as the lid material, a good deep-drawn package can be obtained.

The package of the present embodiment can be produced by adhering a multilayer film used as a bottom material and a polyethylene non-woven fabric used as a lid material by an adhesive means such as a heat seal. Specifically, it can be produced by heat sealing in a temperature range of 105 to 135 ° C. Further, in the package of the present embodiment, the peel strength between the multilayer film 1 and the polyethylene non-woven fabric is preferably 120 to 770 (g / 25 mm), preferably 120 to 750 (g / 25 mm). More preferred. When the above-mentioned peel strength is at least the lower limit of the above preferable range, the sealing property of the package is obtained, and when it is at least the upper limit, good openability, for example, fiber tearing and fluffing during peeling. Suppressive effect can be obtained.

The peel strength can be measured using a tensile tester (for example, manufactured by A & D Co., Ltd., TENSILON RTG-1310, etc.) in accordance with JIS Z0237.

As described above, according to the multilayer film of the present embodiment, since the sealant layer provided to be the surface layer contains a resin having a melting point of 80 to 110 ° C., it has a wide range of 135 ° C. or lower. It can be heat-sealed with polyethylene non-woven fabric in a temperature range, and has good peelability.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs and the like within a range that does not deviate from the gist of the present invention. For example, the multilayer film 1 shown in FIG. 1 has a structure in which the sealant layer 2 and the base material layer 3 are laminated in this order, but this is an example, and the present invention is not limited thereto. For example, in the multilayer film according to the embodiment of the present invention, as shown in FIG. 2, the sealant layer 2, the base material layer 30, the base material layer 31, the adhesive resin layer 4, and the pinhole resistant layer 5 are laminated in this order. The adhesive resin layer 4 and the pinhole-resistant layer 5 may be alternately laminated by two layers each, or three or more layers may be alternately laminated. It may be.

Further, the multilayer film 1 may be newly provided with a layer having another function between each layer or between the outermost layers on the opposite side of the sealant layer 2. For example, from the viewpoint of imparting oxygen gas barrier properties to the multilayer film 1, a resin layer made of an ethylene-vinyl alcohol copolymer resin may be provided. Further, from the viewpoint of imparting strength to the multilayer film 1, a resin layer made of polypropylene-based resin (PP) may be provided. Further, from the viewpoint of imparting flexibility to the multilayer film 1, a resin layer made of an ethylene-vinyl acetate copolymer layer (EVA layer) or a polyethylene layer (PE layer) may be provided.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

<Manufacturing of multilayer film>
(Example 1)
A multilayer film having the configuration shown in FIG. 1 was produced by the following procedure.
As the resin contained in the base material layer 1, high-density polyethylene (made of prime polymer, product number: Hi-Zex 3300F) was prepared.
Further, as the resin contained in the sealant layer, an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 88 ° C. (manufactured by Mitsui / DuPont Polychemical Co., Ltd., product number: Evaflex V5714RC) and homopropylene having a melting point of 160 ° C. ( Made of prime polymer, product number: Y-400GP) were prepared and kneaded so as to have a ratio of 60:40.
Next, as shown in Table 1 below, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 100 μm.
The melting point of each resin was measured using differential scanning calorimetry (DSC6220 manufactured by SII) based on JIS K-7121. In a nitrogen atmosphere, the temperature is raised from 25 ° C to 180 ° C at a rate of 2 ° C / min, cooled to -40 ° C at a rate of 50 ° C / min, and then heated again to 180 ° C at a rate of 2 ° C / min. The melting point at the time of the second temperature rise was measured. When two or more melting point peaks were detected, the high temperature side was taken as the melting point. The same applies below.

(Example 2)
As the resin contained in the sealant layer, as shown in Table 1 below, the same as in Example 1 except that a resin obtained by kneading an ethylene-vinyl acetate copolymer (EVA) resin and homopropylene at a ratio of 75:25 is used. , A multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 90 μm.

(Example 3)
As shown in Table 1 below, the substrate layer 1 / is the same as in Example 1 except that high-density polyethylene (made of prime polymer, product number: Hi-Zex 2100J) is prepared as the resin contained in the substrate layer 1. A two-layered multilayer film in the order of the sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 105 μm.

(Example 4)
As the resin contained in the sealant layer, as shown in Table 1 below, the same as in Example 1 except that a resin obtained by kneading an ethylene-vinyl acetate copolymer (EVA) resin and homopropylene at a ratio of 75:25 is used. , A multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 125 μm.

(Example 5)
As the resin contained in the sealant layer, as shown in Table 1 below, the same as in Example 1 except that a resin obtained by kneading ethylene-vinyl acetate copolymer (EVA) resin and homopropylene at 90:10 is used. , A multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 100 μm.

(Example 6)
High-density polyethylene (manufactured by Prime Polymer, product number: Hi-Zex 2100J) is prepared as the resin contained in the base material layer 1, and an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 87 ° C. (EVA) is used as the resin used for the sealant layer. Prepare Ube Maruzen Polyethylene Co., Ltd., product number: UBE polyethylene V315) and homopropylene (made by Prime Polymer, product number: Y-400GP) with a melting point of 160 ° C., and knead them so that the ratio is 75:25. Except for the above, as shown in Table 1 below, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion in the same manner as in Example 1. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 90 μm.

(Example 7)
As the resin used for the sealant layer, an ethylene-ethyl acrylate copolymer (EEA) resin having a melting point of 93 ° C. (manufactured by NUC Co., Ltd., product number: EEA NUC-6170) and homopropylene having a melting point of 160 ° C. (manufactured by Prime Polymer, product number:: Y-400GP) was prepared and kneaded in a ratio of 75:25, but in the same manner as in Example 1, the order of the base material layer 1 / sealant layer was as shown in Table 1 below. The two-layered multilayer film of No. 1 was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 90 μm.

(Example 8)
As the resin used for the sealant layer, an ethylene-methylmethacrylate copolymer (EMMA) resin having a melting point of 87 ° C. (manufactured by Japan Polystyrene Co., Ltd., product number: Lexpearl EB230X) and homopropylene having a melting point of 160 ° C. (manufactured by Prime Polymer, product number:) Y-400GP) was prepared and kneaded in a ratio of 75:25, but in the same manner as in Example 1, the order of the base material layer 1 / sealant layer was as shown in Table 1 below. The two-layered multilayer film of No. 1 was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 95 μm.

(Example 9)
Ethylene-methylmethacrylate copolymer (EMMA) resin (manufactured by Sumitomo Chemical Co., Ltd., product number: Aklift WH303-F) having a melting point of 89 ° C. and homopropylene (manufactured by Prime Polymer Co., Ltd., product number) having a melting point of 160 ° C. are used as resins for the sealant layer. : Y-400GP) and kneaded to a ratio of 75:25, but in the same manner as in Example 1, as shown in Table 1 below, the substrate layer 1 / sealant layer A multilayer film having a two-layer structure in the order was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 100 μm.

(Example 10)
High-density polyethylene (made of Prime Polymer, product number: Hi-Zex 2100J) is prepared as the resin contained in the base material layer 1, and an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 88 ° C. (EVA) is used as the resin used for the sealant layer. Prepare Mitsui-Dupont Polychemical Co., Ltd., product number: Evaflex V5714RC) and homopropylene with a melting point of 158 ° C (Sumitomo Chemical Co., Ltd., product number: Nobleen WF836DG3) so that the ratio is 75:25. As shown in Table 1 below, a two-layered multilayer film in the order of base material layer 1 / sealant layer was produced by extrusion in the same manner as in Example 1 except for kneading. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 105 μm.

(Example 11)
High-density polyethylene (made of Prime Polymer, product number: Hi-Zex 2100J) is prepared as the resin contained in the base material layer 1, and an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 88 ° C. (EVA) is used as the resin used for the sealant layer. Prepare Mitsui-Dupont Polychemical Co., Ltd., product number: Evaflex V5714RC) and homopropylene with a melting point of 148 ° C (Sumitomo Chemical Co., Ltd., product number: Noblen FH2311) so that the ratio is 75:25. As shown in Table 1 below, a two-layered multilayer film in the order of base material layer 1 / sealant layer was produced by extrusion in the same manner as in Example 1 except for kneading.
The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 105 μm.

(Example 12)
High-density polyethylene (made by Prime Polymer, product number: Hi-Zex 2100J) is prepared as the resin contained in the base material layer 1, and linear low-density polyethylene resin (manufactured by sabi, product number) having a melting point of 94 ° C. is used as the resin used for the sealant layer. : NEXLEENE8402) and homopropylene (made of prime polymer, product number: Y-400GP) having a melting point of 160 ° C. are prepared and kneaded in the same manner as in Example 1 except that they are kneaded so as to have a ratio of 95: 5. As shown in Table 1 below, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film is as shown in Table 1, and the total thickness was 90 μm.

(Example 13)
A multilayer film having the configuration shown in FIG. 2 was produced by the following procedure.
First, as a resin contained in the pinhole-resistant layer, 6-nylon (Ny) (manufactured by Ube Kosan Co., Ltd., product number: 1022B) was prepared.
Further, as a resin contained in the adhesive resin layer (hereinafter, simply referred to as “adhesive layer”), an adhesive polyethylene resin (manufactured by Mitsui Chemicals, Inc., product number: NF536) was prepared.
Further, high-density polyethylene (manufactured by Prime Polymer, product number: Hi-Zex 3300F) is prepared as the resin contained in the base material layer 1, and linear low-density polyethylene (LLDPE) resin (LLDPE) resin is used as the resin contained in the base material layer 2. Made by Dow, product number: Elite 5220G) was prepared.
Further, as the resin contained in the sealant layer, an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 88 ° C. (manufactured by Mitsui / DuPont Polychemical Co., Ltd., product number: Evaflex V5714RC) and homopropylene having a melting point of 160 ° C. ( Made of prime polymer, product number: Y400-GP) were prepared and kneaded so as to have a ratio of 75:25.

Next, as shown in Table 1 below, a multilayer film having a five-layer structure in the order of pinhole-resistant layer / adhesive layer / base material layer 2 / base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 120 μm.

(Example 14)
Ethylene-vinyl acetate copolymer (EVA) resin with a melting point of 88 ° C. (manufactured by Mitsui-Dupont Polychemical Co., Ltd., product number: Evaflex V5714RC) and homopropylene with a melting point of 160 ° C. (manufactured by Prime Polymer, product number: Y400-GP) And low density polyethylene (LDPE) resin (manufactured by Ube Maruzen Polyethylene Co., Ltd., product number: Umerit 82105M) are prepared and kneaded so as to have a ratio of 71:24: 5, in the same manner as in Example 13. Then, as shown in Table 1 below, a multilayer film having a five-layer structure in the order of pinhole resistant layer / adhesive layer / base material layer 2 / base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 120 μm.

(Example 15)
Ethylene-vinyl acetate copolymer (EVA) resin with a melting point of 88 ° C. (manufactured by Mitsui-Dupont Polychemical Co., Ltd., product number: Evaflex V5714RC) and homopropylene with a melting point of 160 ° C. (manufactured by Prime Polymer, product number: Y400-GP) And low density polyethylene (LDPE) resin (manufactured by Ube Maruzen Polyethylene Co., Ltd., product number: Umerit 82105M) are prepared and kneaded so as to have a ratio of 81: 14: 5, but the same as in Example 13. Then, as shown in Table 1 below, a multilayer film having a five-layer structure in the order of pinhole resistant layer / adhesive layer / base material layer 2 / base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 120 μm.

(Comparative Example 1)
A multilayer film having the configuration shown in FIG. 1 was produced by the following procedure.
As the resin contained in the base material layer 1, high-density polyethylene (made of prime polymer, product number: Hi-Zex 3300F) was prepared.
Further, as a resin contained in the sealant layer, a linear low density polyethylene (LLDPE) resin having a melting point of 120 ° C. (manufactured by Prime Polymer Co., Ltd., product number: Ultozex 2022L) was prepared.
Next, as shown in Table 1 below, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 105 μm.

(Comparative Example 2)
As the resin contained in the sealant layer, the following is the same as in Comparative Example 1 except that an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 98 ° C. (manufactured by Tosoh Corporation, product number: Ultrasen 534) is prepared. As shown in Table 1, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 105 μm.

(Comparative Example 3)
Same as Comparative Example 1 except that an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 88 ° C. (manufactured by Mitsui DuPont Polychemical Co., Ltd., product number: Evaflex V5714RC) is prepared as the resin contained in the sealant layer. Then, as shown in Table 1 below, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 105 μm.

(Comparative Example 4)
A multilayer film having the configuration shown in FIG. 2 was produced by the following procedure.
First, nylon (manufactured by Ube Kosan Co., Ltd., product number: 1022B) was prepared as a resin contained in the pinhole-resistant layer.
Further, as a resin contained in the adhesive layer, an adhesive polyethylene-based resin (manufactured by Mitsui Chemicals, Inc., product number: NF536) was prepared.
Further, as the resin contained in the base material layer 1, an ionomer (ION) resin (manufactured by Mitsui DuPont Polychemical Co., Ltd., product number: 1855) was prepared.
Further, as the resin contained in the sealant layer, an ethylene-vinyl acetate copolymer (EVA) resin having a melting point of 88 ° C. (manufactured by Mitsui-DuPont Polychemical Co., Ltd., product number: Evaflex V5714RC) was prepared.

Next, as shown in Table 1 below, a multilayer film having a five-layer structure in the order of pinhole resistant layer / adhesive layer / base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 100 μm.

(Comparative Example 5)
Table 1 below is the same as in Comparative Example 1 except that a linear low density polyethylene (LLDPE) resin (manufactured by Prime Polymer Co., Ltd., product number: Evolu SP0540) having a melting point of 90 ° C. is prepared as the resin contained in the sealant layer. As shown in the above, a multilayer film having a two-layer structure in the order of base material layer 1 / sealant layer was produced by extrusion processing. The thickness (μm) of each layer of the obtained film was as shown in Table 1, and the total thickness was 110 μm.

<Evaluation method>
The multilayer film obtained in Examples and Comparative Examples and a medical packaging material (manufactured by DuPont, "Tyvek (registered trademark) 4058B") are laminated so that the Tyvek side is on the hot plate side, and Teflon (registered trademark) is used. ) After placing the sheet, it was sealed under the following conditions using an auto cup sealer. The peeling direction was evaluated by peeling the film in the MD direction.
-Seal pressure: 11.2 kgf / cm ² (1.1 MPa)
-Seal time: 3.5 seconds-Seal temperature: 100, 110, 120, 130 ° C (at 10 ° C intervals, 4 conditions)
The heat sealability and the peelability were evaluated for all the evaluation samples of the packages obtained in Examples and Comparative Examples.

(Evaluation of heat sealability)
The heat sealability was evaluated by measuring the peel strength at a seal width of 25 mm using a tensile tester (TENSILON RTG-1310 manufactured by A & D Co., Ltd.). The peeling speed was 200 mm / min. Table 1 shows the peel strength of the evaluation samples prepared at each sealing temperature for Examples and Comparative Examples.

(Evaluation of peelability)
The peelability was evaluated by peeling off the lid material and the bottom material of the package as the evaluation sample.
The evaluation was made by observing the peeled surfaces of the lid material and the bottom material after peeling, respectively, and judging according to the following criteria. Table 1 shows the evaluation results of the peelability of the evaluation samples prepared at each sealing temperature for Examples and Comparative Examples.
Judgment A: The lid material is not torn and the bottom material is not adhered with fibers. Judgment B: The lid material is torn or the bottom material is adhered with fibers.

As shown in Table 1, in Examples 1 to 15, the sealant layer of the multilayer film used as the bottom material has a first resin having a melting point of 80 to 110 ° C. and a second resin having a melting point of 130 to 200 ° C. In all evaluation samples with a sealing temperature of 110 to 130 ° C., the peel strength is in the range of 120 to 770 g / 25 mm, heat sealing is possible in a wide temperature range of 135 ° C. or less, and heat sealing is possible. It was confirmed that it was excellent in sex. Further, it was confirmed that in all the evaluation samples having a sealing temperature of 100 to 130 ° C., the lid material was not torn when peeled off, and the fibers did not adhere to the bottom material, so that the peelability was excellent.

On the other hand, in Comparative Examples 1 to 5, since the sealant layer is composed of one kind of resin having a melting point of 80 to 120 ° C., the bottom material is used in any of the evaluation samples having a sealing temperature of 100 to 130 ° C. It was confirmed that the fibers adhered to the surface to a large extent and the peelability was inferior. It was also confirmed that the peel strength exceeded 800 g / 25 mm in all the samples having a sealing temperature of 130 ° C. In particular, in Comparative Examples 3 and 4, it was confirmed that the peel strength exceeded 800 g / 25 mm in all the evaluation samples having a sealing temperature exceeding 110 ° C. Further, in Comparative Examples 1, 2 and 5, the peel strength was lower than 50 g / 25 mm in the evaluation sample at 100 ° C.

It is possible to provide a multilayer film that can be heat-sealed with a polyethylene non-woven fabric in a wide temperature range of 135 ° C. or lower and has good peelability.

1 ... Multilayer film 2 ... Sealant layer 3 ... Base material layer 30 ... Base material layer 1
31 ... Base material layer 2
4 ... Adhesive resin layer 5 ... Pinhole resistant layer

Claims (5)

At least a sealant layer provided so as to be a surface layer and a base material layer provided adjacent to the sealant layer and containing a polyethylene-based resin are provided.
The sealant layer contains a first resin having a melting point of at least 80 to 110 ° C. and a second resin having a melting point of 130 to 200 ° C.
The first resin contains an ethylene-vinyl acetate copolymer and contains
The second resin contains homopolypropylene and contains
With a multilayer film capable of heat-sealing with polyethylene non-woven fabric at 110 ° C.
With polyethylene non-woven fabric,
A package in which at least a part of the sealant layer of the multilayer film is heat-sealed on the surface of the nonwoven fabric. The package according to claim 1, wherein the content of the first resin in the sealant layer is 50 to 99% by mass, and the content of the second resin is 1 to 50% by mass. The package according to claim 1 or 2, wherein the base material layer contains a high-density polyethylene resin. The package according to any one of claims 1 to 3, wherein the ratio of the thickness of the sealant layer to the base material layer is in the range of 1: 0.5 to 1:10. The package according to any one of claims 1 to 4, wherein the peel strength between the multilayer film and the non-woven fabric is 120 to 770 (g / 25 mm).

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