JP2022188380A - Packaging film, packaging material with the same, packaging bag and package - Google Patents

Abstract

To provide a packaging film or the like capable of imparting superiority in slippage for an oil-in-water dispersion type content by heat treatment.SOLUTION: A packaging film comprises a first resin layer containing resin and a porous filler. The resin contains a polyolefin and a silylated polyolefin, and the porous filler has an oil absorption of 100 to 380 mL/100 g.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present disclosure relates to films for packaging materials, and packaging materials and packages including the same.

BACKGROUND ART Conventionally, a package containing an oil-in-water dispersion type content such as curry has been known. In such a package, when the package is opened and the contents are discharged, the contents cannot be completely used up, resulting in waste, stains due to adhesion of the contents, and the contents. Problems such as the need for time-consuming discharge work have been pointed out.

Therefore, the package is required to allow the contents to easily slide down when the package is opened, that is, to provide the contents with an excellent slip-down property.

For example, in Patent Document 1, a package comprising a heat-seal layer having an average particle size D50 of 10 to 50 μm and a melting point of 100 to 180° C. containing polyolefin particles and a surface roughness Ra of 1.00 to 7.00 μm It has been proposed to make the surface of the contents less likely to adhere to the surface of the package using a sheet so that the contents can be easily discharged from the package.

WO2018/003978

However, the package described in Patent Document 1 has the following problems.
That is, the package described in Patent Document 1 has room for improvement in terms of easiness of discharging the contents when opened, that is, sliding down.

The present disclosure has been made in view of the above circumstances, and a packaging film capable of imparting excellent sliding properties to oil-in-water dispersion type contents by heat treatment, a packaging material comprising the same, a packaging bag, and The object is to provide a package.

In the present disclosure, the oil-in-water dispersion type content means a content containing water and lipid, and the content of water is higher than the content of lipid. "Fat" is a concept that includes oil that is liquid at 20°C (normal temperature) and fat that is solid at 20°C. Hereinafter, the oil contained in the oil-in-water dispersion type content and the fat that becomes liquid by the heat treatment applied to the packaging film according to the present disclosure are collectively referred to as “oil”.

In order to solve the above problems, the present disclosure includes a first resin layer containing a resin and a porous filler, the resin contains a polyolefin and a silylated polyolefin, and the porous filler has an oil absorption of 100 to It is a packaging film of 380 mL/100 g.

According to this film for packaging materials, it is possible to impart excellent sliding properties to the oil-in-water dispersion type contents by heat treatment.

The reason why the film for packaging materials of the present disclosure provides the above effects is presumed to be as follows.

That is, the polyolefin contained in the resin in the first resin layer can absorb oil under the temperature conditions of retort treatment or boiling treatment. For this reason, for example, a packaging film is used as a packaging material for a package containing an oil-in-water dispersion type content, and the oil-in-water dispersion type content is brought into contact with the surface of the first resin layer of the packaging film. When heat treatment such as retort treatment or boiling treatment is performed in this state, part of the oil in the contents is absorbed by the first resin layer, and the lipophilicity of the first resin layer is improved. On the other hand, since the first resin layer contains a porous filler, unevenness is formed on the surface of the first resin layer. It becomes possible to increase the area. In addition, since the porous filler has a specific range of oil absorption, it is possible to effectively adsorb oil. Absorption into the resin layer is promoted, and an oil film can be easily formed on the surface of the first resin layer due to moderate oil absorption. As a result, an oil film is stably formed between the surface of the first resin layer and the contents. For this reason, when the package is opened and the contents are dropped, the contents whose surface layer is made of water tend to slip on the water-repellent oil film. However, friction still occurs between the contents and the oil film. Therefore, if the friction between the first resin layer and the oil film is large and the oil film does not easily slide down on the first resin layer, the contents will not easily slide down. In this respect, the film for packaging materials of the present disclosure contains silylated polyolefin in the resin in the first resin layer, so that the friction between the first resin layer and the oil film is reduced, and the first resin layer The oil film easily slides down against the oil film, and the contents of the oil-in-water dispersion type easily slide down together with the oil film. In this way, it is speculated that the film for packaging materials of the present disclosure may provide the above effects.

In the first resin layer, the amount of the silylated polyolefin added is preferably 0.1 to 20% by mass based on 100% by mass of the polyolefin.

In this case, in the first resin layer, compared to the case where the amount of silylated polyolefin added is less than 0.1% by mass based on 100% by mass of polyolefin, the friction between the first resin layer and the oil film can be effectively reduced, and the oil film can be easily slid down on the first resin layer. In addition, in the first resin layer, the heat treatment makes it easier to form an oil film on the surface of the first resin layer than when the amount of silylated polyolefin added exceeds 20% by mass based on 100% by mass of polyolefin. can be formed to

In the film for packaging material, the polyolefin and the polyolefin site of the silylated polyolefin are incompatible, and the first resin layer is a first compatible site compatible with the polyolefin, and the silylated It is preferable to further include a compatibilizer having a second compatibility site that is compatible with at least part of the polyolefin.
The term "incompatible" as used herein means that when a polyolefin is blended with a polyolefin moiety of a silylated polyolefin, the polyolefin moiety is not uniformly dispersed in the polyolefin and forms a sea-island structure.

When the polyolefin and the polyolefin portion of the silylated polyolefin are incompatible, the first resin layer contains the compatibilizer, so that the first compatible portion of the compatibilizer can be compatible with the polyolefin. , the second compatibility site of the compatibilizer can be compatible with at least a portion of the silylated polyolefin. Therefore, the aggregation of the silylated polyolefins is further suppressed, the friction between the first resin layer and the oil film can be effectively reduced, and the oil film can easily slide down on the first resin layer. be able to.

In the packaging film, the mass ratio of the compatibilizing agent to the silylated polyolefin is preferably 0.05-20.

In this case, compared to the case where the mass ratio is less than 0.05, the aggregation of the silylated polyolefin is more suppressed in the first resin layer, and the friction between the first resin layer and the oil film is effectively reduced. can be lowered, and the oil film can be easily slid down on the first resin layer.
In addition, as compared with the case where the mass ratio exceeds 20, the coating of the silylated polyolefin with the compatibilizer is suppressed, the aggregation of the silylated polyolefin in the first resin layer is further suppressed, and the first resin layer and the oil film are suppressed. can effectively reduce the friction between, and the oil film can be easily slid down on the first resin layer.

Further, the present disclosure is a packaging material including the packaging film described above.

Since this packaging material contains the film for packaging material, the oil-in-water dispersion type content is obtained by heat-treating the packaging material while the oil-in-water dispersion type content is in contact with the surface of the first resin layer. It can give excellent sliding properties to objects.

The present disclosure is a packaging bag using the packaging material described above and having the first resin layer disposed inside.

According to this packaging bag, the packaging film contained in the packaging material can impart excellent sliding properties to the oil-in-water dispersion type contents that come into contact with the first resin layer by the heat treatment. For this reason, after the content of the oil-in-water dispersion type is enclosed in the packaging bag to obtain the package, if the package is subjected to heat treatment such as retort treatment or boiling treatment, after opening the package When the oil-in-water dispersion type content is discharged from the package, the oil-in-water dispersion type content can be easily slid down. Therefore, it is possible to reduce the amount of residual liquid in the contents of the oil-in-water dispersion type, prevent waste of the contents, prevent contamination due to adhesion of the contents, and efficiently perform the work of discharging the contents. can be done.

The packaging bag is effectively used for containing an oil-in-water dispersion type content.

The present disclosure is a package including the above-described packaging bag and an oil-in-water dispersion type content enclosed in the packaging bag.

According to this package, the packaging film contained in the packaging material can impart excellent slipping properties to the oil-in-water dispersion type contents that come into contact with the first resin layer by the heat treatment. Therefore, when heat treatment such as retort treatment or boiling treatment is performed on the package, when the oil-in-water dispersion type content is discharged from the package after opening the package, the content of the oil-in-water dispersion type You can easily drop things. Therefore, it is possible to reduce the amount of residual liquid in the contents of the oil-in-water dispersion type, prevent waste of the contents, prevent contamination due to adhesion of the contents, and efficiently perform the work of discharging the contents. can be done.

ADVANTAGE OF THE INVENTION According to this indication, the film for packaging materials which can provide the oil-in-water dispersion|distribution film with the excellent sliding property by heat processing, a packaging material, and a packaging body provided with the same are provided.

FIG. 1 is a cross-sectional view schematically showing one embodiment of a packaging material according to the present disclosure. FIG. 2(a) to FIG. 2(c) are a series of schematic diagrams illustrating the mechanism by which the packaging material according to the present disclosure can impart excellent sliding properties to oil-in-water dispersion type contents. FIG. 3 is a cross-sectional view showing one embodiment of a package according to the present disclosure. FIG. 4(a) to FIG. 4(e) are a series of schematic diagrams for explaining a method for evaluating the sliding property of the contents of the packaging material.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or equivalent constituent elements are denoted by the same reference numerals, and overlapping descriptions are omitted. Also, the dimensional ratios in the drawings are not limited to the illustrated ratios.

<Packaging material>
First, an embodiment of the packaging material of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a cross-sectional view schematically showing an embodiment of the packaging material according to the present disclosure, and FIGS. It is a series of schematic diagrams explaining the mechanism that can provide excellent sliding property against.

A packaging material 100 shown in FIG. 1 is used to form a packaging bag for containing an oil-in-water dispersion type content. The oil-in-water dispersion type content is a content containing water and oil, and the content of water is higher than the content of oil. The amount of oil contained in the oil-in-water dispersion type content is, for example, 0.1% by mass or more and less than 50% by mass, and may be 0.5 to 40% by mass or 1 to 20% by mass. Specific examples of oil-in-water dispersion type contents include curry, hayashi, pasta sauce (eg, meat sauce), and pet food. The amount of oil contained in curry is, for example, about 0.2 to 15% by mass, and the amount of water contained in curry is, for example, about 70 to 90% by mass.

The packaging material 100 includes a substrate 10 , a packaging film 20 provided on the substrate 10 , and an adhesive layer 30 that bonds the substrate 10 and the packaging film 20 together.

The packaging film 20 includes a first resin layer 21 and a second resin layer 22, and the second resin layer 22 is arranged between the first resin layer 21 and the substrate 1. It is That is, the surface S of the first resin layer 21 opposite to the substrate 10 is exposed. The surface S of the first resin layer 21 becomes the inner surface of a packaging bag (for example, a retort pouch) when the packaging material 100 is used to form the packaging bag.

The first resin layer 21 contains a resin composition 21a and porous fillers 21b dispersed in the resin composition 21a. The resin composition 21a contains resin, and the resin includes polyolefin and silylated polyolefin. The oil absorption of the porous filler 21b is 100-380 mL/100 g.

According to the packaging material 100, the polyolefin contained in the first resin layer 21 of the packaging film 20 can absorb oil under the temperature conditions (80° C. or higher) of retort treatment or boiling treatment. is. Therefore, the packaging material 100 is used as a package enclosing the oil-in-water dispersion type content C, and the oil-in-water dispersion type content C is brought into contact with the surface S of the first resin layer 21 of the packaging film 20. (see FIG. 2(a)), and in this state, when heat treatment such as retort treatment or boiling treatment (heat treatment at 80 ° C. or higher) is performed, the oil content _CO contained in the content C Part of it is absorbed by the first resin layer 21 (see FIG. 2(b)), and the lipophilicity of the first resin layer 21 is improved.

On the other hand, since the first resin layer 21 contains the porous filler 21b, unevenness is formed on the surface S of the first resin layer 21, and the contact between the first resin layer 21 and the oil-in-water dispersion type contents C It is possible to increase the area, that is, the oil passage area. In addition, since the porous filler 21b has an oil absorption of 100 to 380 mL/100 _g , it is possible to effectively adsorb oil _CO . Absorption of the contained oil content C 2 _O into the first resin layer 21 is facilitated, and an oil film F 2 _O can be easily formed on the surface S of the first resin layer 21 by moderate oil absorption.

As a result, an oil film _FO is stably formed between the surface S of the first resin layer 21 and the contents C. For this reason, the content C _whose surface layer is made of water becomes easy to slip on the water-repellent oil film FO, and as shown in FIG. 2C, the oil-in-water dispersion type content C Simply inclining the surface S of the packaging material 100 makes it easier to slide on the oil film _FO . However, since friction still occurs between the contents _C and the oil film _FO , if the friction between the first resin layer 21 and the oil film FO is large and the first resin layer 21 When the oil film _FO is difficult to slide down, the content C is difficult to slide down. In that respect, since the first resin layer 21 contains silylated polyolefin in the resin, the friction between the first resin layer 21 and the oil film _FO is reduced, and the oil film The F 2 _O slides down easily, and the oil-in-water dispersion type content C easily slides down together with the oil film _FO . As a result, the packaging material 100 can impart excellent sliding properties to the oil-in-water dispersion type contents C by heat treatment.

Moreover, since polyolefin has heat-sealing properties, the first resin layer 21 can also serve as a sealant film. Therefore, when forming a package, the packaging material 100 can be easily formed by heat-sealing the first resin layers 21 with the first resin layer 21 facing inward. .

The first resin layer 21, the second resin layer 22, the substrate 10, and the adhesive layer 30, which constitute the packaging material 100, will be described below.

(First resin layer)
The first resin layer 21 is subjected to heat treatment (for example, retort treatment and boiling treatment) while in contact with the oil-in-water dispersion type content C, so that the oil-in-water dispersion type content C It is a layer that provides excellent sliding properties.

(A) Polyolefin The polyolefin may be non-silylated polyolefin, and examples of such polyolefin include polypropylene, polyethylene, and polybutylene. Among them, polypropylene is preferable because of its excellent heat resistance. Examples of polyethylene include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, and the like. Examples of polypropylene include homopolypropylene, block polypropylene, random polypropylene, propylene-α-olefin copolymer, and modified polypropylene. When block polypropylene and random polypropylene are used in combination as polypropylene, the mass ratio of block polypropylene and random polypropylene (block polypropylene/random polypropylene) is preferably from 20/80 to 80/20, and from 40/60 to More preferably 60/40. Besides the above, the polyolefin may be a cyclic polyolefin such as polynorbornene. As the polyolefin, a linear polyolefin is preferable from the viewpoint of sealing properties and strength physical properties (tensile strength, impact strength, etc.), and the linear polyolefin may be linear or branched.

Examples of α-olefin components in ethylene-α-olefin copolymers and propylene-α-olefin copolymers include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1- Pentene and the like can be exemplified. The copolymer may be a random copolymer or a block copolymer.

Modified polypropylene is obtained by graft-modifying polypropylene with an unsaturated carboxylic acid derivative component derived from, for example, an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, or the like. Modified polypropylene such as hydroxyl-modified polypropylene and acrylic-modified polypropylene can also be used as the polypropylene. Examples of the α-olefin component used to obtain the propylene-based copolymer include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, and the like. can.

(C) Silylated Polyolefin A silylated polyolefin is a silylated polyolefin and contains a polyolefin moiety and a silicone moiety.

Examples of silylated polyolefins include products manufactured by Dow Corning Toray Co., Ltd. as PE-Si graft copolymers, Exfola manufactured by Mitsui Chemicals Fine Co., Ltd. as triblock copolymers of PE-Si-PE, PP- Products manufactured by Dow Corning Toray Co., Ltd. may be used as Si graft copolymers. Here, the polyolefin portion of the PE-Si-PE triblock copolymer is polyethylene (PE), and the silicone portion is Si.

As the silylated polyolefin, a block copolymer is preferable to a graft copolymer. This is because the block copolymer tends to bleed out from the first resin layer 21 more easily.

The silylated polyolefins mentioned above can be used singly or in combination of two or more.

In the first resin layer 21, the amount of silylated polyolefin added is not particularly limited as long as it is greater than 0% by mass based on 100% by mass of polyolefin, but is preferably 0.1 to 20% by mass. It is preferably 1 to 10% by mass, and particularly preferably 3 to 7% by mass.

In this case, in the first resin layer 21, the first resin layer 21 and the oil film F _O , and the oil film F 2 can be easily _slid down on the first resin layer 21 . In addition, in the first resin layer 21, the oil film on the surface S of the first resin layer 21 is reduced by the heat treatment compared to the case where the amount of silylated polyolefin added exceeds 20% by mass based on 100% by mass of polyolefin. _FO can be formed more easily.

(D) Compatibilizer The resin composition 21a contained in the first resin layer 21 may or may not contain a compatibilizer that compatibilizes the polyolefin and the silylated polyolefin. When the polyolefin part of the silylated polyolefin is incompatible, it is preferable to further include a compatibilizer that makes the polyolefin and the silylated polyolefin compatibilized.

When the polyolefin and the polyolefin portion of the silylated polyolefin are incompatible, the first resin layer 21 contains a compatibilizing agent so that the polyolefin and the silylated polyolefin can be compatibilized. Therefore, the aggregation of the silylated polyolefin is further suppressed, the friction between the first resin layer 21 and the oil film F 2 _O can be effectively reduced, and the oil film F 2 _O can be easily slid off.

More preferably, the compatibilizer includes a compatibilizer having a first compatibility site that is compatible with the polyolefin and a second compatibility site that is compatible with at least a portion of the silylated polyolefin.

In this case, the first compatibility site of the compatibilizer can be compatible with the polyolefin, and the second compatibility site of the compatibilizer can be compatible with at least part of the silylated polyolefin. Therefore, the aggregation of the silylated polyolefin is further suppressed, the friction between the first resin layer 21 and the oil film F 2 _O can be effectively reduced, and the oil film F 2 _O can be easily slid off.

The first compatible site that is compatible with polyolefin includes a polyolefin site that is compatible with polyolefin. The first compatibility site is preferably a polyolefin site of the same type as the polyolefin, since better compatibility with polyolefin can be easily obtained. That is, when the polyolefin is polyethylene, the first compatible site is preferably the polyethylene site, and when the polyolefin is polypropylene, the first compatible site is preferably the polypropylene site. Further, when the polyolefin is a copolymer composed of two or more olefins such as an ethylene-α-olefin copolymer and a propylene-α-olefin copolymer, the first compatible site is the olefin constituting the copolymer. Among them, it is preferable that the site has at least a structure obtained by polymerizing or copolymerizing the same olefin as the main component olefin.

The second compatible site that is compatible with at least a portion of the silylated polyolefin includes a polyolefin site that is compatible with the polyolefin site of the silylated polyolefin. The second compatibility site is preferably a polyolefin site of the same type as the polyolefin site of the silylated polyolefin, since better compatibility with the polyolefin site of the silylated polyolefin is likely to be obtained. That is, when the polyolefin portion of the silylated polyolefin is a polyethylene portion, the second compatible portion is preferably a polyethylene portion, and when the polyolefin portion of the silylated polyolefin is a polypropylene portion, the second compatible portion is a polypropylene portion. is preferably Further, when the polyolefin portion of the silylated polyolefin is a copolymer portion composed of two or more olefins such as an ethylene-α-olefin copolymer portion and a propylene-α-olefin copolymer portion, the second compatible portion is It is preferable that the site has at least a structure obtained by polymerizing or copolymerizing the same olefin as the main component olefin among the olefins constituting the copolymer site.

For example, when polypropylene is used as the polyolefin and a PE-Si-PE triblock copolymer is used as the silylated polyolefin, a PP-PE block copolymer can be used as the compatibilizer. At this time, in the compatibilizer, the first compatible site is the PP (polypropylene) site, and the second compatible site is the PE (polyethylene) site.

The mass ratio of the compatibilizer to the silylated polyolefin is not particularly limited, but is preferably 0.05 to 20, more preferably 0.1 to 10, and 0.5 to 5. is particularly preferred.

In this case, as compared with the case where the mass ratio is less than 0.05, aggregation of the silylated polyolefin is further suppressed in the first resin layer 21, and friction between the first resin layer 21 and the oil film _FO can be effectively reduced, and the oil film F ₂ can easily slide down on the first resin layer 21 . In addition, as compared with the case where the mass ratio exceeds 20, the coating of the silylated polyolefin with the compatibilizer is suppressed, the aggregation of the silylated polyolefin in the first resin layer 21 is further suppressed, and the first resin layer 21 and the oil film _FO can be effectively reduced, and the oil film _FO can be easily slid onto the first resin layer 21 .

(B) Porous Filler The porous filler 21b adsorbs the oil content C 2 _O absorbed by the first resin layer 21 from the oil-in-water dispersion type content C in the heat treatment, and includes the main body. The body portion included in the porous filler 21b may be inorganic or organic. Examples of organic substances include polyolefins and acrylic resins. Examples of acrylic resins include crosslinked poly(meth)acrylic acid esters such as crosslinked polymethyl methacrylate. These can be used individually or in combination of 2 or more types. Examples of inorganic substances include silica, talc, ceramics, glass beads, mineral fillers such as calcium carbonate, carbon black, glass fibers, ceramic fibers and carbon fibers. These can also be used individually or in combination of 2 or more types. Examples of the porous filler 21b made of an organic substance include the Techpolymer MBP series manufactured by Sekisui Plastics Co., Ltd., the Techpolymer ACP series manufactured by Sekisui Plastics Co., Ltd., and the like. Examples of the porous filler 21b made of an inorganic substance include Silophorbic series manufactured by Fuji Silysia Chemical Co., Ltd., and Sunsphere series manufactured by AGC Si Tech Co., Ltd., and the like.

The porous filler 21b may further include a covering portion that covers at least a portion of the main body portion. The covering portion may be made of a hydrophilic material or a hydrophobic material, but is preferably made of a hydrophobic material. Here, the hydrophobic material refers to a material having a DBA (di-n-butylamine) value of 200 mEq/kg or less, and the DBA value refers to the amount of DBA adsorbed on the surface of the main body. The DBA value corresponds to the amount of DBA adsorbed to the hydroxyl groups on the surface of the main body, and the smaller the DBA value, the smaller the hydroxyl groups (higher hydrophobicity).

The porous filler 21b composed of the main body portion and the coating portion can be obtained, for example, by chemically reacting the main body portion with a raw material of a hydrophobic material, that is, by subjecting the main body portion to a hydrophobic treatment. . Raw materials for the hydrophobic material include, for example, organosilicon compounds. Among them, organosilicon compounds are preferable as the starting material for the hydrophobic material.

The oil absorption of the porous filler 21b is 100-380 mL/100 g. Here, "oil absorption" refers to the oil absorption measured in accordance with JIS K5101-13 (Pigment test method-Part 13: Oil absorption).

When the oil absorption of the porous filler 21b is within the above range, it is possible to effectively adsorb oil CO 2 _O during the heat treatment of the packaging material 100 compared to when the oil absorption is less than 100 mL/100 g. and can promote the absorption of the oil content C 2 _O contained in the oil-in-water dispersion type content C into the first resin layer 21, so that the packaging film 20 is enclosed in the package. Excellent slideability can be effectively imparted to the oil-in-water dispersion type content C. In addition, compared to the case where the oil absorption exceeds 380 mL / 100 _g , the porous filler 21 b moderately adsorbs oil, making it easier to form an oil film FO on the surface S of the first resin layer 21. The lumber film 20 can provide the oil-in-water dispersion type content C enclosed in the package with more excellent slipping properties.

The oil absorption of the porous filler 21b is more preferably 110 mL/100 g or more, and particularly preferably 120 mL/100 g or more.

However, the oil absorption of the porous filler 21b is preferably 300 mL/100 g or less. In this case, the porous filler 21b more moderately adsorbs oil, making it easier to form an oil film _FO on the surface S of the first resin layer 21, so that the packaging film 20 is enclosed in the package. It is possible to provide the oil-in-water dispersion type content C thus obtained with a more excellent slide-down property.

The average particle size (Y μm) of the porous filler 21b is obtained by the following method according to the type of filler.
(Calculation method by laser diffraction particle size distribution measurement)
(1) Disperse the porous filler 21b in a dispersion medium. The dispersion medium is, for example, water or an organic solvent, and an appropriate one is selected according to the type of filler.
(2) Using a laser diffraction particle size distribution analyzer (product name: “MT3300EX II”, manufactured by Microtrack Bell), the average particle size of the porous filler 21b is calculated by a laser diffraction/scattering method.
(Calculation method by microscope observation)
If the laser diffraction particle size distribution measurement is not suitable or difficult, an optical microscope such as a scanning electron microscope (SEM) or a laser microscope may be used to determine the average particle size of the porous filler 21b.
The length of the longest diameter and the shortest diameter of an arbitrary particle within the field of view observed by microscopic observation is measured, and the sum divided by 2 is taken as the particle diameter. Particle sizes are measured and calculated for a plurality of particles, and the average value thereof is regarded as the average particle size. The number of the arbitrary particles is preferably 10 or more.

Although the average particle diameter (Y μm) of the porous filler 21b is not particularly limited, it is preferably 5 μm or more. In this case, an appropriate addition amount of the porous filler 21b makes it possible to impart an appropriate unevenness to the surface S of the first resin layer 21, so that the physical properties of the packaging film 20, such as a decrease in seal strength, are not affected. It is possible to effectively improve the slipping property of the contents C while reducing the amount.

The average particle diameter (Y μm) of the porous filler 21b is more preferably 3 μm or more, particularly preferably 7 μm or more.

However, the average particle diameter (Y μm) of the porous filler 21b is preferably 30 μm or less. In this case, compared to the case where the average particle diameter (Y μm) of the porous filler 21b exceeds 30 μm, it becomes easier to form the oil film _FO on the surface S of the first resin layer 21, and the packaging film 20 is The oil-in-water dispersion type content C enclosed in the package can be given more excellent slipping properties.

The average particle diameter (Y μm) of the porous filler 21b is more preferably 20 μm or less, further preferably 15 μm or less.

In the first resin layer 21, the amount of the porous filler 21b added is, for example, 0.5 to 10% by mass, preferably 1 to 8% by mass, more preferably 2% with respect to 100% by mass of polyolefin. ~8% by mass. When the amount of the porous filler 21b added is within the above range, the surface S of the first resin layer 21 can be provided with appropriate unevenness.

The thickness (X μm) of the first resin layer 21 is a value obtained as follows.
(1) First, a structure is prepared by fixing the packaging film 20 with an embedding resin (acrylic resin).
(2) A sample for cross-sectional observation is cut out from the structure using a microtome.
(3) The cross section of the cut sample for cross section observation is observed with a microscope (product name: VHX-1000, manufactured by Keyence Corporation).
(4) Measure the thickness at three locations where the porous filler 21b is not present along the thickness direction of the first resin layer 21, and calculate the average value of the thicknesses at these three locations. Calculated as thickness (X μm).

The thickness (X μm) of the first resin layer 21 is, for example, 2 to 100 μm, preferably 4 to 70 μm, more preferably 6 to 50 μm, still more preferably 8 to 30 μm. When the thickness of the first resin layer 21 is within the above range, it is possible to achieve a high level of both sliding down property and heat-sealing property of the contents C. Here, the heat-sealability is, for example, a property that enables heat-sealing under the conditions of 100 to 200° C., 0.1 to 0.3 MPa, and 1 to 3 seconds.

(Second resin layer)
The second resin layer 22 is a layer provided between the first resin layer 21 and the substrate 10 . By further including the second resin layer 22 in the packaging material 100, the function of the second resin layer 22 (heat sealability, heat resistance, impact resistance, oxygen/water vapor barrier properties, etc.) can be packaged. material 100 can be applied. For example, the second resin layer 22 preferably contains a thermoplastic resin from the viewpoint of improving heat sealability. Specific examples of thermoplastic resins include polyolefins, ethylene-α,β-unsaturated carboxylic acid copolymers or esterified products thereof or ionic cross-linked products thereof, ethylene-vinyl acetate copolymers or saponified products thereof, polyvinyl acetate or saponified products thereof. , polycarbonate resins, thermoplastic polyester resins, ABS resins, polyacetal resins, polyamide resins, polyphenylene oxide resins, polyimide resins, polyurethane resins, polylactic acid resins, furan resins, and silicone resins. These thermoplastic resins can be used singly or in combination of two or more.

The thickness of the second resin layer 22 can be appropriately set according to the application of the packaging material 100 . The thickness of the second resin layer 22 is, for example, 1 to 300 μm, preferably 2 to 200 μm, more preferably 5 to 150 μm, still more preferably 10 to 100 μm.

(Base material)
The substrate 10 is not particularly limited as long as it serves as a support and has durability against heat treatment such as retort treatment or boiling treatment. Examples thereof include resin films and metal foils. Examples of resin films include polyolefins (e.g., polyethylene (PE), polypropylene (PP), etc.), acid-modified polyolefins, polyesters (e.g., polyethylene terephthalate (PET), etc.), polyamides (PA), polyvinyl chloride (PVC), cellulose acetate, A film containing at least one type of cellophane resin is included. This film may be a stretched film or a non-stretched film. Examples of metal foil include aluminum foil and nickel foil. The base material 10 may be a laminate of a plurality of base materials made of different materials, or may include a coat layer or a metal deposition layer.

The thickness of the base material 10 can be appropriately set according to the use of the packaging material 100 . The thickness of the substrate 10 is, for example, 1-500 μm, and may be 10-100 μm.

(adhesive layer)
The adhesive layer 30 bonds the packaging film 20 (laminated body of the first resin layer 21 and the second resin layer 22 ) and the substrate 10 . The adhesive constituting the adhesive layer 30 is not particularly limited as long as it can bond the packaging film 20 and the base material 10, and examples of such an adhesive include polyester Examples include polyurethane resins obtained by reacting a base material such as polyol, polyether polyol, acrylic polyol, carbonate polyol with a difunctional or higher isocyanate compound. Various polyols may be used singly or in combination of two or more.

For the purpose of promoting adhesion, the adhesive layer 30 may contain a carbodiimide compound, an oxazoline compound, an epoxy compound, a phosphorus compound, a silane coupling agent, or the like in the polyurethane resin described above. Depending on the performance required for the adhesive layer 30, other various additives and stabilizers may be added to the polyurethane resin described above.

The thickness of the adhesive layer 30 is, for example, 1 to 10 μm, and may be 3 to 7 μm, from the viewpoint of obtaining desired adhesive strength, conformability, workability, and the like.

It is also possible to provide an adhesive primer (anchor coat) on the substrate 10, and the material thereof includes polyester-based resin, polyurethane-based resin, polyallylamine-based resin, polyethyleneimine-based resin, polybutadiene-based resin, and ethylene-acetic acid. Vinyl copolymers, chlorine-vinyl acetate resins, and the like can be used. The adhesive primer may optionally contain various curing agents and additives that can be used as adhesives.

<Method for manufacturing packaging material>
Next, a method for manufacturing the packaging material 100 described above will be described.

The packaging material 100 can be obtained by laminating the packaging film 20 and the substrate 10 with an adhesive. Examples of the method for bonding the base material 10 and the packaging film 20 include a lamination method using an adhesive and a lamination method using a heat treatment.

As a lamination method using an adhesive, various known lamination methods such as a dry lamination method, a wet lamination method, and a non-solvent lamination method can be used.

Lamination methods by heat treatment are roughly classified into the following methods (1) to (4).
(1) A method of extruding and laminating an adhesive resin between a prefabricated packaging film 20 and a substrate 10 (2) Co-extrusion of the packaging film 20 and an adhesive resin, and (3) A method of bonding the laminate obtained by the above method (1) or (2) by applying pressure while heating with hot rolls. (4) A method of storing the laminate obtained by the above method (1) or (2) in a high-temperature atmosphere, or passing it through a drying/baking furnace in a high-temperature atmosphere.

<Packaging bag and package>
Next, one embodiment of the package of the present disclosure will be described with reference to FIG. FIG. 3 is a cross-sectional view showing one embodiment of the package of the present disclosure;

As shown in FIG. 3 , the package 300 includes a packaging bag 200 and an oil-in-water dispersion type content C enclosed in the packaging bag 200 . In the package 300, the first resin layer 21 of the packaging film 20 of the packaging bag 200 is arranged inside and is in contact with the oil-in-water dispersion type content C. As shown in FIG.

According to the packaging body 300, the packaging film 20 contained in the packaging material 100 forming the packaging bag 200 is subjected to heat treatment to the oil-in-water dispersion type content C that contacts the first resin layer 21. can provide excellent sliding properties. Therefore, if heat treatment such as retort treatment or boiling treatment is performed on the package 300, when the oil-in-water dispersion type content C is discharged from the package 300 after the package 300 is opened, the oil in water Distributed contents C can be easily slid down. Therefore, the amount of residual liquid in the oil-in-water dispersion type content C can be reduced, the waste of the content C can be prevented, the contamination due to the adhesion of the content C can be prevented, and the operation of discharging the content C can be reduced. can be done efficiently.

The package 300 can be obtained by forming the packaging bag 200 using the packaging material 100 and enclosing the oil-in-water dispersion type content C in the packaging bag 200 .

Although the embodiments of the present disclosure have been described above in detail, the present disclosure is not limited to the above embodiments. For example, in the above embodiment, the packaging film 20 is composed of the first resin layer 21 and the second resin layer 22, but the packaging film 20 is composed only of the first resin layer 21. or may further include one or more resin layers.

In addition, the packaging material 100 includes the adhesive layer 30 that bonds the packaging film 20 and the base material 10, but if the packaging film 20 and the base material 10 can be directly fused, Alternatively, the adhesive layer 30 can be omitted.

Furthermore, packaging material 100 does not necessarily have substrate 10 .

EXAMPLES Hereinafter, the present disclosure will be described more specifically with reference to examples and comparative examples, but the present disclosure is not limited to the following examples.

Materials used in Examples and Comparative Examples are as follows.
(A) Polyolefin (A1) PP1
Propylene-ethylene random copolymer (trade name “F744NP”, manufactured by Prime Polymer Co., Ltd.) and propylene-ethylene block copolymer (trade name “Novatec BC5FA”, manufactured by Japan Polypropylene Corporation) were mixed at a ratio of 1:1 (mass ratio). ) Mixture (A2) PP2
Block polypropylene (propylene-ethylene block copolymer, trade name “Novatec BC3HF”, manufactured by Japan Polypropylene Corporation)
(A3) PE
Linear low-density polyethylene (LLDPE, trade name “Novatec LL UF442”, manufactured by Japan Polypropylene Corporation)

(B) Porous filler (B1) Porous silica filler Average particle size: 20 μm, Oil absorption: 150 mL/100 g, Hydrophobic treatment: None, trade name “Sunsphere H-201”, manufactured by AGC Si Tech Co., Ltd. (B2 ) Porous silica filler average particle size: 12 μm, oil absorption: 300 mL / 100 g, hydrophobization treatment: none, trade name “Sunsphere H-122”, manufactured by AGC Si Tech Co., Ltd. (B3) porous silica filler average particle size : 7 μm, oil absorption: 120 mL/100 g, hydrophobization treatment: none, trade name “Sunsphere L-71-N”, manufactured by AGC Si Tech Co., Ltd. (B4) porous silica filler average particle size: 4.1 μm, oil absorption Amount: 170 mL/100 g, DBA value: 65 mEq/kg, trade name “Silophobic 702”, Fuji Silysia Chemical Co., Ltd. (B5) porous silica filler average particle size: 6.7 μm, oil absorption: 50 mL/100 g, DBA value: 200 mEq/kg, trade name “Silophobic 603”, manufactured by Fuji Silysia Chemical Co., Ltd. (B6) porous silica filler average particle size: 5 μm, oil absorption: 400 mL/100 g, hydrophobic treatment: none, trade name "Sunsphere H-53", manufactured by AGC Si Tech Co., Ltd.

(C) Triblock copolymer of silylated polyolefin PE-Si-PE: trade name "EXFORA", manufactured by Mitsui Chemicals Fine Co., Ltd.

(D) compatibilizer polypropylene-polyethylene block copolymer

<Production of packaging material>
(Examples 1 to 19 and Comparative Examples 1 to 5)
Using a co-extruder, a two-layer packaging film (sealant film) comprising a first resin layer having the composition shown in Tables 1 and 2 and a second resin layer having the composition shown in Tables 1 and 2. was made. In Tables 1 and 2, "addition amount (% by mass)" is the amount added to 100% by mass of polyolefin.

Next, the obtained film for packaging material, a PET film with a thickness of 38 μm (trade name “EMBRET”, manufactured by Unitika Ltd.) as a base material, and a polyurethane adhesive (manufactured by Mitsui Chemicals, Inc.) A packaging material was obtained by dry-laminating using the resin and aging at 50° C. for 5 days. In the examples and comparative examples, the first resin layer and the second resin layer were formed so that the total thickness of the first resin layer and the second resin layer was 60 μm.

<Sliding property evaluation of contents>
(Residual liquid evaluation after retort treatment)
The packaging materials obtained in Examples and Comparative Examples were evaluated for slipping property of contents after retort treatment by the method shown in FIGS. 4(a) to 4(e).

First, two pieces of packaging material cut into a size of 150 mm long and 138 mm wide were prepared. Then, the two packaging materials were placed one on top of the other with the first resin layers facing inside, and three sides were sealed using a heat sealer. In this way, as shown in FIG. 4(a), a packaging bag 200 composed of a pouch having seal portions 200a formed on three sides and one side being open was produced. At this time, the three sides were heat-sealed under the conditions of 190° C., 0.03 MPa, and 2 seconds, and the width of the sealed portion 200a was 10 mm.

Next, as shown in FIG. 4(b), curry as content C from the opening of the packaging bag 200 (trade name “Bon Curry Gold Medium Spicy”, fat content 7.0 g / 180 g, manufactured by Otsuka Foods Co., Ltd.) 180 g was injected.

After that, the opening (the remaining side) was sealed using a heat sealer to form a sealed portion 200b on the remaining side as shown in FIG. 4(c). In this way, a package 300 with four sides sealed and containing the content C was produced. At this time, the heat sealing of the opening was performed under the conditions of 190° C., 0.03 MPa, and 2 seconds, and the width of the sealed portion 200b was 10 mm.

The package 300 thus produced was put into a high-temperature and high-pressure cooking and sterilization apparatus (manufactured by Hitachi Capital Co., Ltd.) and subjected to retort treatment with high-temperature steam. The retort treatment was performed under the following conditions.
・ Pressure: 0.2 MPa
・Temperature 121℃
・Processing time: 30 minutes

After the retort treatment, the package 300 was subjected to hot water bath treatment at 100° C. for 5 minutes. After that, as shown in FIG. 4(d), the upper part of the package 300 was cut to form a spout. Next, as shown in FIG. 4( e ), the pouch is turned upside down and held for 10 seconds with the spout tilted 45° from the horizontal plane, and the content C is discharged into the container 400 , and the discharged amount is measured by the scale 500 . was weighed. Then, the remaining liquid ratio (%) was determined from the weighed discharge amount by the following formula.

Remaining liquid ratio (%) = {(180-discharge amount) / 180} x 100

The same measurement was performed three times by changing the package 300, and the average value of the remaining liquid percentages of the three times was calculated as the average remaining liquid percentage. In addition, based on the average residual liquid ratio, the slide-down property of the contents was evaluated according to the following evaluation criteria. Tables 1 and 2 show the results of the evaluation of the average residual liquid ratio and the slipping property of the contents.
A: Average residual liquid rate is less than 6.5% B: Average residual liquid rate is 6.5% or more and less than 8.0% C: Average residual liquid rate is 8.0% or more and less than 10.0% D: Average residual liquid Liquid ratio is 10.0% or more

(Appearance evaluation after retort treatment)
When measuring the residual liquid ratio as described above, the discharge behavior of the contents C when the contents (curry) C was discharged from the pouch was visually observed, and the appearance was also evaluated according to the following evaluation criteria. . The results are shown in Tables 1-2.
A: Contents slide down cleanly, and there is almost no adhesion of the contents to the packaging film.
B: A state that the contents slide down is observed, and the amount of the contents adhering to the packaging film is small.
C: Although the contents are seen to slide down, the amount of the contents adhering to the packaging film is large.
D: A state in which the content slides down is not observed.

From the results shown in Tables 1 and 2, the packages obtained in Examples 1 to 19 had a small average remaining liquid ratio, and it was observed that the contents slid down from the appearance. On the other hand, the packages obtained in Comparative Examples 1 to 5 had a large average remaining liquid ratio, and the contents did not slide down from the appearance.

From the above, it was confirmed that, according to the packaging film of the present disclosure, the heat treatment can impart excellent slide-down properties to the oil-in-water dispersion type contents.

DESCRIPTION OF SYMBOLS 10... Base material 20... Film for packaging materials 21... First resin layer 21a... Resin composition 21b... Porous filler 30... Adhesive layer 100... Packaging material 200... Packaging bag 300... package, C... content, _CO ... oil content, S... surface of the first resin layer, _FO ... oil film.

Claims (8)

A first resin layer containing a resin and a porous filler,
the resin comprises a polyolefin and a silylated polyolefin;
A packaging film, wherein the porous filler has an oil absorption of 100 to 380 mL/100 g. 2. The packaging film according to claim 1, wherein the amount of said silylated polyolefin added to said first resin layer is 0.1 to 20% by mass based on 100% by mass of said polyolefin. the polyolefin and the polyolefin portion of the silylated polyolefin are incompatible,
4. The first resin layer further comprises a compatibilizer having a first compatible site that is compatible with the polyolefin and a second compatible site that is compatible with at least part of the silylated polyolefin. 3. The film for packaging materials according to 1 or 2. 4. The packaging film according to claim 3, wherein the mass ratio of said compatibilizer to said silylated polyolefin is 0.05-20. A packaging material comprising the packaging film according to any one of claims 1 to 4. A packaging bag made of the packaging material according to claim 5, wherein the first resin layer is arranged inside. 7. The packaging bag according to claim 6, which is used to contain an oil-in-water dispersion type content. The packaging bag according to claim 7;
and an oil-in-water dispersion type content enclosed in the packaging bag.

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