JP7331457B2 - Liquid-repellent resin composition, and liquid-repellent film, liquid-repellent laminate and packaging material using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for forming a liquid-repellent layer, and a liquid-repellent film, a liquid-repellent laminate and a packaging material using the same.

2. Description of the Related Art Conventionally, packaging materials have been developed for many products such as foods, beverages, pharmaceuticals, and chemicals, depending on the contents of each product. In particular, as packaging materials for contents such as liquids, semi-solids, and gel substances, plastic materials are used which are excellent in water resistance, oil resistance, gas barrier properties, lightness, flexibility, and design.

In addition, as a packaging material for contents such as liquids, semi-solids, and gel-like substances, for the purpose of providing higher functionality, plastic laminates in which multiple types of plastic substrates are laminated, paper, metal foil, and inorganic materials are used. Composite laminates of materials and plastic substrates, composites obtained by treating plastic substrates with functional compositions, and the like have been proposed.

As one of the high functions described above, for example, a function of suppressing adhesion of contents such as liquids, semi-solids, and gelatinous substances to the inner surface of the packaging material, that is, the function of suppressing the residue inside the package is required. More specifically, lid materials for containers such as yogurt, jelly, and syrup; packaging materials for retort food such as porridge, soup, curry, and pasta sauce; Contents adhere to the inner surface of film materials for containers, and it is not possible to use up all the contents, resulting in waste. There is a demand for high liquid repellency capable of suppressing the occurrence of contamination.

In response to these demands, Patent Document 1, for example, proposes a water-repellent packaging material in which a silicone resin composition layer containing hydrophobic fine particles such as silicone particles is provided on the inner surface of the packaging material. In addition, Patent Document 2 proposes a packaging material having a resin layer containing spherical silicon as the innermost layer and having water repellency and releasability for contents.

JP 2013-23224 A JP-A-8-337267

Polyolefin resins such as polyethylene and polypropylene are used as the material for the resin layer on the inner surface of the packaging material as a material that imparts functions such as heat sealability, heat resistance and impact resistance. However, even when the above-described silicone particles are added to the polyethylene resin to impart liquid repellency, the polyethylene resin absorbs excessive oil and forms an oil film when subjected to heat treatment such as boiling. As a result, the liquid-repellent effect of the silicone particles is reduced, and the effect of suppressing the adhesion of contents to the inner surface of the packaging material is not always sufficient.

The present invention has been made in view of the above problems of the prior art, and provides a resin composition capable of forming a liquid-repellent layer capable of sufficiently suppressing adhesion of contents, and a liquid-repellent resin composition using the same. An object of the present invention is to provide a flexible film, a liquid-repellent laminate, and a packaging material.

In order to solve the above problems, the present invention
Provided is a resin composition for forming a liquid-repellent layer, comprising (A) a polyethylene resin, (B) a silylated polyolefin, and (C) a polyethylene/polypropylene copolymer.

According to the resin composition for forming a liquid-repellent layer, (A) a polyethylene resin, (B) a silylated polyolefin, and (C) a polyethylene/polypropylene copolymer are used in combination to sufficiently adhere contents. It is possible to form a liquid-repellent layer capable of suppressing the (B) Silylated polyolefin is a component that imparts liquid repellency to the liquid-repellent layer. When heat treatment such as treatment is performed, the amorphous part of the low molecular weight polyethylene resin contained in the liquid-repellent layer on the inner surface of the pouch tends to swell with oil, and the oil contained in the contents is excessively absorbed by the polyethylene resin. As a result, an oil film is likely to be formed, and the liquid-repellent effect of the silicone portion of the (B) silylated polyolefin has deteriorated. On the other hand, the present inventors found that by adding (C) a polyethylene/polypropylene copolymer, the degree of crystallinity and melting point of polyethylene can be controlled, and the amount of swelling in oil can be controlled. In addition, by controlling the amount of polyethylene/polypropylene copolymer (C) added, when the liquid-repellent layer is formed, the degree of deposition of Si in the (B) silylated polyolefin on the surface of the liquid-repellent layer is also controlled. The inventors have found that it is possible to

According to the resin composition for forming a liquid-repellent layer of the present invention, by adding (C) a polyethylene/polypropylene copolymer, the amount of oil swelling of the liquid-repellent layer formed can be controlled and the surface of the liquid-repellent layer It is possible to achieve both an improvement in the amount of Si present, and as a result, excellent liquid repellency can be obtained. Here, when (C) the polyethylene/polypropylene copolymer is not added, the crystallinity and melting point of polyethylene are lowered, and the swelling of oil makes it difficult for Si to deposit on the surface of the liquid-repellent layer, resulting in a decrease in liquid repellency. As a result, the amount of residual liquid increases. When the amount of oil swelling in the liquid-repellent layer increases, the amount of residual liquid increases correspondingly, and a large amount of oil and fat is deposited on the surface of the liquid-repellent layer. This results in a decrease in the properties and a further increase in the amount of residual liquid. In this manner, the absorption of oil can be suppressed, the oil film is less likely to be formed, and the liquid repellent layer can be effectively imparted with liquid repellency. This makes it possible to form a liquid-repellent layer having a liquid-repellent property superior to that in the case of using conventional silicone particles.

In the liquid-repellent layer-forming resin composition, the mass ratio of the content of the polyethylene/polypropylene copolymer (C) to the content of the silylated polyolefin (B) (the mass of the polyethylene/polypropylene copolymer (C) /(B) mass of silylated polyolefin) may be 0.1-20. When the content ratio is within the above range, the formed liquid-repellent layer can more sufficiently suppress adhesion of contents.

The present invention also provides a liquid-repellent film having a liquid-repellent layer formed using the resin composition for forming a liquid-repellent layer of the present invention. According to such a liquid-repellent film, by providing the liquid-repellent layer formed using the resin composition for forming a liquid-repellent layer of the present invention, adhesion of contents to the liquid-repellent layer can be sufficiently suppressed. can be done. In addition, the liquid-repellent film exhibits good liquid repellency not only to water and oil, but also to oil-in-water dispersion type contents that undergo heat treatment such as boiling treatment such as curry and pasta sauce. be able to.

The liquid-repellent film may further include one or more resin layers provided on one main surface of the liquid-repellent layer. By forming the liquid-repellent film into a multi-layered structure including a resin layer other than the liquid-repellent layer, it becomes possible to impart further functionality (heat resistance, impact resistance, etc.) in addition to the liquid repellency. In addition, it is possible to reduce the thickness of the liquid-repellent layer and reduce the cost.

When the liquid-repellent film has a resin layer other than the liquid-repellent layer, the melting point T ₁ (°C) of the polyethylene resin (A) in the liquid-repellent layer and the liquid-repellent layer among the one or more resin layers The melting point T ₂ (° C.) of the resin contained in the resin layer in contact with may satisfy the relationship of T ₁ <T ₂ . By satisfying the above relationship, from the viewpoint of crystallinity, the (B) silylated polyolefin in the liquid-repellent layer can be suppressed from migrating to the resin layer in contact with the liquid-repellent layer among the one or more resin layers. Since the silylated polyolefin (B) can be unevenly distributed on the surface of the liquid-repellent layer or the efficiency of bleeding out can be improved, the liquid repellency tends to be further improved.

The present invention also provides a liquid-repellent laminate comprising a substrate and the liquid-repellent film of the present invention provided on the substrate, wherein the liquid-repellent layer is disposed on at least one outermost surface. provide the body According to such a liquid-repellent laminate, by providing the liquid-repellent film of the present invention, adhesion of contents to the liquid-repellent layer can be sufficiently suppressed. Further, by laminating the liquid-repellent film on a substrate having a desired function, the liquid-repellent laminate can be imparted with functions such as mechanical strength, barrier properties, and light-shielding properties.

The present invention also provides a packaging material formed using the liquid-repellent laminate of the present invention so that the liquid-repellent layer is the innermost layer. According to such a packaging material, since it is formed using the liquid-repellent laminate of the present invention, adhesion of contents to the liquid-repellent layer can be sufficiently suppressed.

The packaging material may be used for a heat treatment at 60°C to 100°C. According to the packaging material according to the present embodiment, even when used for such purposes, adhesion of contents to the inner surface of the packaging material can be suppressed even after the heat treatment.

ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can form the liquid-repellent layer which can fully suppress adhesion of a content, and a liquid-repellent film, a liquid-repellent laminated body, and a packaging material using the same are provided. can do.

1 is a schematic cross-sectional view of a liquid-repellent laminate according to one embodiment of the present invention; FIG. 1 is a schematic cross-sectional view of a liquid-repellent laminate according to one embodiment of the present invention; FIG. It is a schematic diagram explaining the liquid-repellent evaluation method of a liquid-repellent laminated body. It is a schematic diagram explaining the liquid-repellent evaluation method of a liquid-repellent laminated body.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted. Also, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[Liquid-repellent laminate]
The liquid-repellent laminate according to the present embodiment includes a base material and a liquid-repellent film provided on the base material, and has a structure in which a liquid-repellent layer is disposed on at least one outermost surface. is. 1 and 2 are schematic cross-sectional views of the liquid-repellent laminate according to this embodiment. In the liquid-repellent laminate according to the present embodiment, a liquid-repellent film 10 composed of a liquid-repellent layer 11 and a base material 14 are bonded together with an adhesive 13 interposed therebetween, like the liquid-repellent laminate 1 shown in FIG. It may have a laminated structure. Further, the liquid-repellent laminate according to the present embodiment, like the liquid-repellent laminate 2 shown in FIG. 14 may have a laminated structure with an adhesive 13 interposed therebetween. The liquid-repellent film 10 is the second resin layer 12
, the liquid-repellent film 10 is arranged such that the liquid-repellent layer 11 is the outermost surface of the liquid-repellent laminate 2 and the second resin layer 12 faces the substrate 14 .

<Liquid Repellent Layer 11>
The liquid repellent layer 11 is a layer having liquid repellency. The liquid-repellent layer 11 may be a layer capable of exhibiting heat-sealing properties by heating. Here, liquid repellency is a concept that includes both water repellency and oil repellency. Specifically, liquid repellency to liquid, semi-solid, or gel-like aqueous or oily materials. is. Aqueous or oily materials include water, oil, yogurt, jelly, pudding, syrup, porridge, soup, curry, foods such as pasta sauce, detergents such as hand soap and shampoo, pharmaceuticals, cosmetics, chemicals, and the like. . The heat-sealability is, for example, the property of being heat-sealable under the conditions of 100 to 200° C., 0.1 to 0.3 MPa, and 1 to 3 seconds. The heat-sealing conditions can be easily changed according to the conditions required for heat-sealing the liquid-repellent laminate.

The thickness of the liquid-repellent layer 11 is preferably 0.1 to 100 μm, more preferably 1 to 70 μm, even more preferably 3 to 50 μm, particularly preferably 5 to 30 μm. When the thickness of the liquid-repellent layer 11 is at least the above lower limit, there is a tendency that good liquid-repellency and heat-sealability can be easily obtained. On the other hand, when the thickness is equal to or less than the above upper limit, the thickness of the entire liquid-repellent laminate can be reduced.

The liquid-repellent layer 11 can be formed using a liquid-repellent layer-forming resin composition containing the following components. The resin composition for forming a liquid-repellent layer will be described below.

<Resin composition for liquid-repellent layer formation>
A resin composition for forming a liquid-repellent layer according to an embodiment of the present invention includes (A) a polyethylene resin (hereinafter also referred to as "(A) component"), (B) a silylated polyolefin (hereinafter referred to as "(B) component ”), and (C) a polyethylene/polypropylene copolymer (hereinafter also referred to as “(C) component”).

That is, the liquid-repellent layer-forming resin composition contains (C) a polyethylene/polypropylene copolymer as an essential component. Each component will be described in detail below.

((A) polyethylene resin)
The polyethylene resin is not particularly limited, and examples thereof include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, and the like. Examples of α-olefin components include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 4-methyl-1-pentene.

Examples of polyethylene resins include Novatec manufactured by Japan Polyethylene Co., Ltd., Evolue manufactured by Prime Polymer Co., Ltd., and the like.

The melting point of the polyethylene resin can be appropriately adjusted according to the end use. For example, for retort food packaging applications, the melting point of the polyethylene resin is preferably 110 to 140°C.

The above polyethylene resins may be used singly or in combination of two or more.

((B) silylated polyolefin)
The silylated polyolefin is a component that imparts liquid repellency to the liquid repellent layer 11 . A silylated polyolefin is a polyolefin unit with 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 PE-Si block copolymers, and PP-Si graft copolymers. Examples of coalescing include products manufactured by Dow Corning Toray Co., Ltd., and Exfola manufactured by Mitsui Chemicals Fine Co., Ltd. as PE-Si-PE triblock copolymers.

From the viewpoint of further improving the liquid repellency of the liquid repellent layer 11, the silylated polyolefin is preferably a block copolymer rather than a graft copolymer. This is because the block copolymer tends to be unevenly distributed or bleed out on the surface of the liquid-repellent layer 11 .

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

((C) polyethylene/polypropylene copolymer)
The polyethylene/polypropylene copolymer is a component having (A) a site compatible with the polyethylene resin and (B) a site compatible with the silylated polyolefin. By using the polyethylene/polypropylene copolymer, the compatibility between (A) the polyethylene resin and (B) the silylated polyolefin whose polyolefin moiety is incompatible with the (A) polyethylene resin can be improved.

(A) The site that is compatible with the polyethylene resin includes a polyolefin structure that is compatible with the (A) polyethylene resin, and is preferably a site that has the same polyolefin structure as the (A) polyethylene resin. That is, (C) the polyethylene/polypropylene copolymer preferably has a polyethylene structure. Further, when (A) the polyethylene resin is a copolymer composed of two or more olefins such as an ethylene-α-olefin copolymer, (C) the polyethylene/polypropylene copolymer is an olefin constituting the copolymer. It is preferable to have at least a structure obtained by polymerizing or copolymerizing the same kind of olefin as the main component olefin.

(B) The site that is compatible with the silylated polyolefin includes a polyolefin structure that is compatible with the polyolefin site of the (B) silylated polyolefin, and has the same polyolefin structure as the polyolefin site of the (B) silylated polyolefin. A site is preferred. That is, when the polyolefin portion of (B) the silylated polyolefin has a polyethylene structure, the (C) polyethylene/polypropylene copolymer preferably has a polyethylene structure, and (B) the polyolefin portion of the silylated polyolefin has a polypropylene structure. (C) the polyethylene/polypropylene copolymer preferably has a polypropylene structure. In addition, when the polyolefin moiety of (B) the silylated polyolefin has a structure based on a copolymer consisting of two or more olefins such as an ethylene-α-olefin copolymer and a propylene-α-olefin copolymer, (C) The polyethylene/polypropylene copolymer preferably has at least a structure obtained by polymerizing or copolymerizing an olefin of the same kind as the olefin that is the main component of the olefins constituting the copolymer.

(C) As the polyethylene/polypropylene copolymer, for example, a block copolymer of ethylene and propylene, or a block copolymer of ethylene and an ethylene/butylene copolymer, or the like can be used. In this case, if the polyolefin portion of (A) the polyethylene resin or (B) the silylated polyolefin is polyethylene, the portion and the polyethylene portion of the (C) polyethylene/polypropylene copolymer are compatible, and (B) the silylated If the polyolefin part of the polyolefin is polypropylene, the part is compatible with the propylene or ethylene/butylene copolymer part of the polyethylene/polypropylene copolymer (C).

The above polyethylene/polypropylene copolymers may be used alone or in combination of two or more.

The content of component (A) in the liquid-repellent layer-forming resin composition is preferably 50.0 to 99.9% by mass based on the total solid content of the liquid-repellent layer-forming resin composition. 0 to 99.0% by mass, more preferably 60.0 to 98.0% by mass. When the content of component (A) is at least the above lower limit, good heat-sealing properties tend to be obtained. On the other hand, if the content of the component (A) is less than the above upper limit, the content of the components (B) and (C) will be relatively increased, so that the liquid repellency tends to be easily improved.

The total content of components (B) and (C) in the liquid-repellent layer-forming resin composition is 0.1 to 50.0% by mass based on the total solid content of the liquid-repellent layer-forming resin composition. , more preferably 1.0 to 45.0% by mass, even more preferably 2.0 to 40.0% by mass. When the total content of the component (B) and the component (C) is at least the above lower limit, the liquid repellency tends to be improved. On the other hand, if the total content of the components (B) and (C) is less than the above upper limit, the content of the component (A) is relatively increased, so good heat sealability tends to be obtained. be.

The mass ratio of the content of component (C) to the content of component (B) in the liquid-repellent layer-forming resin composition (mass of component (C)/mass of component (B)) is 0.1 to 20. Preferably. If the content ratio is at least the above lower limit, the (B) silylated polyolefin can be sufficiently dispersed in the liquid-repellent layer, and there is a tendency that better liquid repellency can be obtained. On the other hand, when the content ratio is equal to or less than the above upper limit, it prevents the (B) silylated polyolefin from being coated with the excess (C) polyethylene/polypropylene copolymer, thereby obtaining better liquid repellency. tend to be able to In addition, when the content ratio exceeds the above upper limit, even if the polyethylene/polypropylene copolymer (C) is added, the silylated polyolefin (B) is no longer dispersed, and the effect of improving the liquid repellency is observed. tend to be lost.

The liquid-repellent layer-forming resin composition may contain other additives, if necessary, to the extent that the liquid-repellent property is not impaired. Other additives include, for example, flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, tackifiers, and the like.

The liquid-repellent layer 11 can be formed by forming a film from the liquid-repellent layer-forming resin composition.

<Second resin layer 12>
The second resin layer 12 is a layer provided between the liquid-repellent layer 11 and the substrate 14 in order to improve heat sealability, heat resistance, impact resistance, oxygen/water vapor barrier properties, and the like. The second resin layer 12 preferably contains a heat-sealable thermoplastic resin.

The thermoplastic resin used for the second resin layer 12 is not particularly limited, but polyolefin resin, ethylene-α,β unsaturated carboxylic acid copolymer or its esterified product or ionic crosslinked product, ethylene-vinyl acetate copolymer. 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 etc. These thermoplastic resins can be used singly or in combination of two or more.

The thermoplastic resin used for the second resin layer 12 preferably contains a polyolefin resin, since heat sealability, heat resistance, and impact resistance are likely to be improved. As the polyolefin resin, the same resin as (A) the polyethylene resin used for the liquid-repellent layer 11 can be used.

When the second resin layer 12 is in contact with the liquid-repellent layer 11, the melting point T ₁ (°C) of the (A) polyethylene resin in the liquid-repellent layer 11 and the thermoplastic resin in the second resin layer 12 The melting point T ₂ (° C.) preferably satisfies the relationship of T ₁ <T ₂ . By satisfying the above relationship, the (B) silylated polyolefin in the liquid-repellent layer 11 can be suppressed from migrating to the second resin layer 12 from the viewpoint of crystallinity, and the (B) to the surface of the liquid-repellent layer 11 can be suppressed. ) Since the uneven distribution or bleeding out efficiency of the silylated polyolefin can be improved, the liquid repellency tends to be further improved. From the same point of view, the melting point _T2 is preferably higher than the melting point _T1 by 1°C or more, more preferably by 3°C or more.

The thickness of the second resin layer 12 can be appropriately set according to the end use of the product using the present liquid-repellent layer-forming resin composition. The thickness of the second resin layer 12 is, for example, preferably 0.1 to 300 μm, more preferably 1 to 200 μm, even more preferably 5 to 150 μm, and 10 to 100 μm. is particularly preferred.

<Liquid repellent film 10>
A liquid-repellent film 10 having liquid-repellency is formed by the above-described liquid-repellent layer 11 single layer or two layers of the liquid-repellent layer 11 and the second resin layer 12 . The liquid-repellent film 10 is formed so as to cover part or all of the surface of the substrate 14 . Depending on the application, the liquid-repellent film 10 may be used alone without being laminated with the base material 14 .

The liquid-repellent film 10 may further include one or more resin layers other than the liquid-repellent layer 11 and the second resin layer 12 . The composition of the other resin layer may be the same as or different from the composition of the second resin layer 12 .

<Base material 14>
The base material 14 is not particularly limited as long as it can serve as a support, and examples thereof include paper, resin film, metal foil, and the like. Examples of paper include woodfree paper, special woodfree paper, coated paper, art paper, cast-coated paper, imitation paper, and kraft paper. 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 14 may be a laminate of a plurality of base materials made of different materials.

The thickness of the base material 14 is not particularly limited, and can be appropriately adjusted depending on the application.

Examples of the method for bonding the base material 14 and the liquid-repellent film 10 include, but are not limited to, a lamination method using an adhesive and a lamination method using heat treatment, as described below.

(Lamination method with adhesive)
As a lamination method using an adhesive, various known lamination methods such as dry lamination, wet lamination, and non-solvent lamination can be used. Examples of the adhesive 13 used in these lamination methods include the following.

<Adhesive 13>
The adhesive 13 bonds the liquid-repellent film 10 and the substrate 14 together. Examples of the adhesive 13 include a polyurethane resin obtained by reacting a base material such as polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol with a difunctional or higher isocyanate compound. The various polyols mentioned above can be used singly or in combination of two or more.

For the purpose of promoting adhesion, the adhesive 13 may further contain a carbodiimide compound, an oxazoline compound, an epoxy compound, a phosphorus compound, a silane coupling agent, or the like in addition to the polyurethane resin described above.

Moreover, according to the performance required for the adhesive 13, the polyurethane resin described above may be blended with various other additives and stabilizers.

The thickness of the adhesive 13 is not particularly limited, but is preferably 1 to 10 μm, more preferably 3 to 7 μm, from the viewpoint of obtaining desired adhesive strength, conformability, workability, and the like.

(Lamination method by heat treatment)
As a lamination method by heat treatment, the following methods are roughly exemplified.
(1) A method of extrusion laminating the liquid-repellent film 10 formed in advance onto the substrate 14 together with an adhesive resin.
(2) A method of extrusion laminating a resin layer and an adhesive resin constituting the liquid-repellent film 10 onto the substrate 14 .
(3) A method of bonding the laminated base material obtained by the above method (1) or (2) by further heating and pressurizing with a hot roll.
(4) A method of storing the laminated base material 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.

Examples of the adhesive resin used in the lamination method by heat treatment include acid-modified polyolefin. In the above method, the substrate 14 and the liquid-repellent film 10 are laminated by extrusion lamination. It is also possible to laminate the liquid-repellent film 10 by heat treatment after coating and forming on 14 .

In addition, it is possible to provide an adhesive primer (anchor coat) on the base material 14, and the materials thereof include polyester, polyurethane, polyallylamine, polyethyleneimine, polybutadiene, and ethylene-vinyl acetate copolymer. It is possible to use coalescence, chlorine-vinyl acetate, etc., and if necessary, the various curing agents and additives described above that can be used as the adhesive 13 may be blended.

[Packaging material]
The packaging material according to this embodiment is formed using the liquid-repellent laminate described above. Specific examples of packaging materials include container lids for yogurt, jelly, syrup, and the like, and retort pouches for porridge, soup, curry, pasta sauce, and the like. By forming the packaging material so that the liquid-repellent layer is arranged on the inner surface (contents side) of the packaging material, it is possible to suppress the adhesion and residue of contents such as liquids, semi-solids, and gel-like substances on the inner surface of the packaging material. can do. In addition, in a bag-shaped packaging material such as a retort food packaging material, blocking between the innermost layers of the packaging material may make it difficult to discharge the contents, but according to the packaging material according to the present embodiment, , the liquid-repellent layers, which are the innermost layers, are unlikely to block each other, and the contents can be discharged efficiently.

The packaging material may be used for a heat treatment at 60 to 100°C. Specifically, it may be used for packaging materials such as retort food packaging materials that are subjected to heat treatment such as boiling in hot water. According to the packaging material according to the present embodiment, even when used for such purposes, it is possible to prevent the contents from adhering or remaining on the inner surface of the packaging material even after the heat treatment.

EXAMPLES The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[Examples 1 to 22]
<Preparation of resin composition for forming liquid-repellent layer>
Linear low density polyethylene (LLDPE, trade name “Evolue”, manufactured by Prime Polymer Co., Ltd.) as component (A) and silylated polyethylene (PE-Si graft copolymer, Toray Industries, Inc.) as component (B) Dow Corning Co., Ltd., or a PE-Si-PE triblock copolymer, trade name "EXFORA", manufactured by Mitsui Chemicals Fine Co., Ltd.) and a block copolymer of PP-PE, which is the component (C) A block copolymer of ethylene and ethylene-butylene copolymer is mixed, and the types and contents of components (B) and (C) are changed as shown in Table 1, and the balance is (A ) component to prepare a resin composition for forming a liquid-repellent layer.

<Preparation of liquid-repellent laminate>
Using a three-layer co-extrusion machine, the liquid-repellent layer-forming resin composition was extruded into a film to obtain a liquid-repellent film having a liquid-repellent layer with a thickness of 100 μm. The resulting liquid-repellent film and a 38 μm-thick PET film (trade name “EMBRET”, manufactured by Unitika Ltd.) as a substrate were dried using a polyurethane adhesive (manufactured by Mitsui Chemicals, Inc.). It was laminated and aged at 50° C. for 5 days to obtain a liquid-repellent laminate.

[Examples 23-28]
<Preparation of resin composition for forming liquid-repellent layer>
In the same manner as in Example 1, the types and contents of the components (B) and (C) were changed as shown in Table 2, and the remainder was the component (A). A resin composition was produced.

<Preparation of liquid-repellent laminate>
Linear low-density polyethylene (LLDPE, trade name “Evolue”, manufactured by Prime Polymer Co., Ltd.), which is the component (A), was used as a resin composition for forming the second resin layer. However, as shown in Table 2, adjustment was made at two points, one having a melting point equivalent to that of the first resin layer and the other having a melting point higher than that of the first resin layer. Using a three-layer co-extrusion machine, the liquid-repellent layer-forming resin composition and the second resin layer-forming resin composition are co-extruded to form a film, forming a liquid-repellent layer with a thickness of 15 μm and a second resin composition with a thickness of 85 μm. A liquid-repellent film consisting of a resin layer was obtained. The second resin layer of the obtained liquid-repellent film and a PET film with a thickness of 38 μm (trade name “EMBRET”, manufactured by Unitika Ltd.) as a base material are bonded together with a polyurethane adhesive (Mitsui Chemicals, Inc. (manufactured) to obtain a liquid-repellent laminate.

The compositions shown in Table 3 were used to prepare the following comparative examples.

[Comparative Example 1]
A liquid-repellent layer-forming resin composition, a liquid-repellent film, and a liquid-repellent laminate were prepared in the same manner as in Example 1, except that only component (A) was used as the liquid-repellent layer-forming resin composition.

[Comparative Example 2]
A liquid-repellent layer-forming resin composition, a liquid-repellent film, and a liquid-repellent laminate were prepared in the same manner as in Example 1, except that component (B) was not added to the liquid-repellent layer-forming resin composition.

[Comparative Example 3]
A liquid-repellent layer-forming resin composition, a liquid-repellent film, and a liquid-repellent laminate were prepared in the same manner as in Example 15, except that component (B) was not added to the liquid-repellent layer-forming resin composition.

[Comparative Example 4]
A liquid-repellent layer-forming resin composition was prepared in the same manner as in Example 2 except that the component (B) was a PP-Si graft copolymer and the component (C) was not added. A liquid-repellent film and a liquid-repellent laminate were produced.

[Comparative Example 5]
A liquid-repellent layer-forming resin composition, a liquid-repellent film, and a liquid-repellent laminate were prepared in the same manner as in Example 2, except that component (C) was not added to the liquid-repellent layer-forming resin composition.

[Comparative Example 6]
A resin composition for forming a liquid-repellent layer, a liquid-repellent film, and a liquid-repellent laminate were prepared in the same manner as in Example 12, except that homo-PP was used as the component (C).

[Comparative Example 7]
A resin composition for forming a liquid-repellent layer, a liquid-repellent film and a liquid-repellent laminate similar to those in Comparative Example 1 were prepared.

[Comparative Example 8]
A resin composition for forming a liquid-repellent layer, a liquid-repellent film and a liquid-repellent laminate similar to those in Comparative Example 2 were prepared.

[Comparative Example 9]
A resin composition for forming a liquid-repellent layer, a liquid-repellent film, and a liquid-repellent laminate similar to those in Comparative Example 4 were prepared.

Details of each component in Tables 1, 2 and 3 are as follows. "-" in the table means that the corresponding component was not used. Tables 1, 2 and 3 show the mass ratio of the content of component (C) to the content of component (B) in the liquid-repellent layer (mass of component (C)/mass of component (B)). showed that. Table 2 also shows the melting point T ₁ (°C) of the resin that is the component (A) used in the liquid-repellent layer and the melting point T ₂ (°C) of the resin that is the component (A) used in the second resin layer. ).

[(A) polyethylene resin]
A1: Linear low-density polyethylene (LLDPE), trade name “Evolue”, melting point 116°C, manufactured by Prime Polymer Co., Ltd. A2: Linear low-density polyethylene (LLDPE), trade name “Novatec LL”, melting point 122°C, Made by Japan Polyethylene Co., Ltd.

[(B) Silylated polyolefin]
B1: PE-Si graft copolymer, manufactured by Dow Corning Toray Co., Ltd. B2: PE-Si-PE triblock copolymer, trade name "Exfora", manufactured by Mitsui Chemicals Fine Co., Ltd. B3: PP-Si graft copolymer, manufactured by Dow Corning Toray Co., Ltd.

[(C) polyethylene/polypropylene copolymer]
C1: block copolymer of propylene and ethylene C2: block copolymer of ethylene and ethylene/butylene copolymer

[Evaluation of liquid repellency]
<Examples 1 to 19, 23 to 26 and Comparative Examples 1 to 6: Liquid repellency after boiling>
Examples 1 to 19, 23 to 26 and Comparative Examples 1 to 6 were evaluated for liquid repellency after boiling by the method shown in FIG. First, two samples 200 were prepared by cutting the liquid-repellent laminates obtained in Examples and Comparative Examples into a size of 150 mm long×138 mm wide. Two samples 200 were stacked so that the liquid-repellent layer of each was on the inside, and one vertical edge and two horizontal edges were sealed with a heat sealer at 190° C. at 0.03 MPa for 2 seconds. A sealed portion 51 was formed by heat sealing over a width of 10 mm under the conditions, and a pouch 50 having one side opened in the longitudinal direction was produced (see (a) of FIG. 3).
Next, 100 g of oil-in-water dispersion type liquid 54 (trade name “Bon Curry”, manufactured by Otsuka Foods Co., Ltd.) was injected from the opening of the pouch (see FIG. 3(b)).
After that, the opening was heat-sealed with a heat sealer over a width of 10 mm under the conditions of 190° C., 0.03 MPa, and 2 sec to form a sealed portion 51 to seal the pouch 50, and the pouch 50 was boiled in a hot water bath in a pot 52 ( See FIG. 3(c)).

After the sealed pouch 50 was boiled in hot water at 100° C. for 5 minutes, the top of the sealed pouch 50 was immediately cut off to form a spout. Next, holding the sealing portion on the opposite side of the spout, holding the pouch upside down for 30 seconds, discharging the oil-in-water dispersion liquid 54 into the container 56, and weighing the discharged amount with a scale 57 (( in FIG. 3) d)).
From the weighed discharge amount, the residual liquid amount (%) was determined by the following formula.
Residual liquid amount (%) = {(100-discharged amount) / 100} x 100
The measurement was performed 3 times, and the liquid repellency was evaluated according to the following evaluation criteria from the average residual liquid amount of 3 times. Tables 1 and 2 show the average residual liquid amount (%) and the evaluation results of the liquid repellency.
◎: Average residual liquid amount is less than 3.0% ○: Average residual liquid amount is 3.0% or more and less than 3.5% △: Average residual liquid amount is 3.5% or more and less than 4.5% ×: Average residual liquid amount Liquid volume is 4.5% or more

<Examples 20 to 22, 27, 28 and Comparative Examples 7 to 9: Liquid repellency without heat treatment>
Examples 20 to 22, 27, 28 and Comparative Examples 7 to 9 were evaluated for liquid repellency without heat treatment by the method shown in FIG. First, two samples 100 were prepared by cutting the liquid-repellent laminates obtained in Examples and Comparative Examples into a size of 150 mm long and 138 mm wide. Two samples 100 are stacked so that the liquid-repellent layer of each is on the inside, and one side of the longitudinal end and two sides of the lateral end are sealed with a heat sealer at 190° C., 0.03 MPa, 2 sec. A sealed portion 61 was formed by heat sealing over a width of 10 mm under the conditions, and a pouch 60 having one longitudinal end open was produced (see FIG. 4(a)).
Next, 100 g of salad oil 62 (trade name “Nissin Salad Oil” manufactured by Nisshin OilliO Co., Ltd.) was injected from the opening of the pouch 60 (see FIG. 4B).
Next, holding the sealing portion on the opposite side of the opening, the pouch 60 was turned upside down and held for 30 seconds, the salad oil 62 was discharged into the container 56, and the discharged amount was weighed by the scale 57 ((c) in FIG. 4). ).
From the weighed discharge amount, the residual liquid amount (%) was determined by the following formula.
Residual liquid amount (%) = {(100-discharged amount) / 100} x 100
The measurement was performed 3 times, and the liquid repellency was evaluated according to the following evaluation criteria from the average residual liquid amount of 3 times. Tables 3 and 4 show the average residual liquid amount (%) and the evaluation results of the liquid repellency.
◎: average residual liquid amount is less than 1.5% ○: average residual liquid amount is 1.5% or more and less than 2.0% △: average residual liquid amount is 2.0% or more and less than 2.5% ×: average residual liquid amount Liquid volume is 2.5% or more

[Appearance evaluation]
In the liquid repellency evaluation, the behavior of the liquid discharged from the pouch was visually observed, and the external appearance was evaluated according to the following evaluation criteria. The results are shown together in Tables 1 to 3.
⊚: Appears to slide off cleanly and does not adhere to the liquid-repellent laminate.
◯: Sliding down is observed, and adhesion to the liquid-repellent laminate is small.
Δ: Appears to slide down, but adheres to the liquid-repellent laminate.
x: A state of sliding down is not observed.

[Swelling amount measurement]
The amount of swelling was measured by the following procedure. The results are shown together in Tables 1 to 3.
(1) At the time of the remaining liquid evaluation described above, measure the weight of the empty pouch before filling with the content.
(2) Wash the pouch after the residual liquid property evaluation with food detergent, wipe the inside of the pouch with isopropyl alcohol, and measure the weight of the pouch.
(3) Calculate the amount of swelling using the following formula. (Number of samples n=3)
Swelling amount (%) = ((2) pouch weight - (1) pouch weight) ÷ (1) pouch weight

As is clear from the results shown in Tables 1 to 3, according to the liquid-repellent laminates of Examples 1-28, compared with the liquid-repellent laminates of Comparative Examples 1-9, the liquid repellency is improved. confirmed that it can be improved.

Further, in the liquid-repellent laminates of Examples 25, 26, and 28, the melting point _T1 of the resin in the liquid-repellent layer and the melting point _T2 of the resin in the second resin layer satisfies the relationship of _T1 < _T2. It was found that the liquid repellency was particularly good.

In addition, it was confirmed that pouches with small weight changes before and after the residual liquid evaluation, that is, pouches with little oil absorption and small swelling amount tended to exhibit high liquid repellency.

DESCRIPTION OF SYMBOLS 1, 2... Liquid-repellent laminate 10... Liquid-repellent film 11... Liquid-repellent layer 12... Second resin layer 13... Adhesive 14... Base material 50, 60 Pouches 51, 61 Seal portion 52 Pot 54 Oil-in-water dispersion type liquid 56 Container 57 Scale 62 Salad oil 100, 200 Liquid repellency Laminate evaluation sample

Claims (7)

(A) a polyethylene resin, (B) a silylated polyolefin, and (C) a polyethylene/polypropylene copolymer ;
The mass ratio of the content of the (C) polyethylene/polypropylene copolymer to the content of the (B) silylated polyolefin (mass of (C) polyethylene/polypropylene copolymer/mass of (B) silylated polyolefin) is , 0.1 to 20 . A liquid-repellent film comprising a liquid-repellent layer formed using the resin composition for forming a liquid-repellent layer according to claim 1 . 3. The liquid-repellent film according to claim 2 , further comprising one or more resin layers provided on one main surface of said liquid-repellent layer. The melting point T1 (°C) of the (A) polyethylene resin in the liquid-repellent layer and the melting point T2 (°C) of the resin contained in the resin layer in contact with the liquid-repellent layer among the one or more resin layers are 4. The liquid-repellent film according to claim 3 , which satisfies a relationship of T1<T2. A liquid-repellent film comprising a substrate and the liquid-repellent film according to any one of claims 2 to 4 provided on the substrate, wherein the liquid-repellent layer is disposed on at least one outermost surface. liquid-repellent laminate. A packaging material, wherein the liquid-repellent layer is formed as the innermost layer using the liquid-repellent laminate according to claim 5 . 7. The packaging material according to claim 6 , which is used for a heat treatment at 60°C to 100°C.