JP2021095538A - Resin composition for liquid-repellent layer formation, and, liquid-repellent film using the same, liquid-repellent laminate and packaging material - Google Patents

Abstract

To provide a resin composition allowing for formation of a liquid-repellent layer that can sufficiently suppress adhesion of contents even when heating processing such as boiling processing is performed, and a liquid-repellent film using the same, a liquid-repellent laminate, and a packaging material.SOLUTION: There is provided a resin composition that contains a polyethylene resin (A), silylated polyolefin (B) and a polyethylene/polypropylene block copolymer (C), and can combine control of an oil swelling amount of a liquid-repellent layer with improvement of abundance of Si on the surface of the liquid-repellent layer, and a liquid-repellent film 11 using the resin composition, a liquid-repellent laminate 1, and a packaging material are also provided.SELECTED DRAWING: Figure 1

Description

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.

Conventionally, packaging materials according to the contents of many products such as foods, beverages, pharmaceuticals, and chemicals have been developed. In particular, as a packaging material for contents such as liquids, semi-solids, and gel-like substances, plastic materials having excellent water resistance, oil resistance, gas barrier properties, light weight, flexibility, design properties, and the like are used.

In addition, as a packaging material for contents such as liquids, semi-solids, and gel-like substances, plastic laminates in which a plurality of types of plastic base materials are laminated, paper, metal foil, and inorganic materials are used for the purpose of providing higher functionality. A composite laminate of a material or the like and a plastic base material, and a composite body obtained by treating a plastic base material with a functional composition have been proposed.

As one of the above-mentioned high functions, for example, a function of suppressing the adhesion of contents such as liquid, semi-solid, and gel-like substance to the inner surface of the packaging material, that is, the function of suppressing the residue inside the packaging body is required. More specifically, storage of container lids such as yogurt, jelly and syrup, retort food packaging materials such as porridge, soup, curry and pasta sauce, liquids of chemicals and pharmaceuticals, semi-solids, gel-like substances, etc. The contents of the film material for containers adhere to the inner surface, and the contents cannot be completely used up, resulting in waste, the adhesion of the contents causes stains, and the work of discharging the contents is troublesome. There is a demand for high liquid repellency that can suppress the application.

In response to these demands, for example, Patent Document 1 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. Further, Patent Document 2 proposes a packaging material having a resin layer to which spherical silicon is added as the innermost layer and having water repellency and releasability of the contents.

Japanese Unexamined Patent Publication No. 2013-23224 Japanese Unexamined Patent Publication No. 8-337267

As a material for the resin layer on the inner surface of the packaging material, a polyolefin resin such as polyethylene or polypropylene is used as a material for imparting functions such as heat sealability, heat resistance and impact resistance. However, even when the above-mentioned silicone particles are added to the polyethylene resin in order to impart liquid repellency, the polyethylene resin excessively absorbs oil and forms an oil film when heat treatment such as boiling treatment is performed. As a result, the liquid-repellent effect of the silicone particles is reduced, and the effect of suppressing the adhesion of the contents to the inner surface of the packaging material is not always sufficient.

Further, conventionally, such a packaging material contains a fatty acid amide such as erucic acid amide to impart slip property, but this fatty acid amide is accompanied by a decrease in sealing property. Further, when manufacturing a filled packaging bag, the contents often adhere to the seal portion, and particularly when the packaging bag is manufactured while filling the contents, the contents adhere to the seal portion. It is inevitable. Therefore, the bag-making material used for bag-making filling has "normal sealing performance", which is the sealing performance of only the packaging bag, and high sealing performance even if the contents (contaminants) adhere to the sealing part. It is required to have "contamination sealing property" or "contamination sealing property" to be exhibited.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a resin composition capable of forming a liquid-repellent layer capable of sufficiently suppressing adhesion of contents, and a liquid-repellent using the same. An object of the present invention is to provide a sex film, a liquid-repellent laminate, and a packaging material. Another object of the present invention is to provide a packaging material capable of imparting good slipperiness and normal sealing property without containing fatty acid amide, and further, the liquid-repellent layer repels the contents during filling and packaging. It is an object of the present invention to suppress the biting of the contents at the time of sealing and to impart the property of sealing impurities.

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

According to the above-mentioned resin composition for forming a liquid-repellent layer, the contents can be adhered by using (A) a polyethylene resin, (B) a silylated polyolefin, and (C) a polyethylene / polypropylene block copolymer in combination. A liquid-repellent layer that can be sufficiently suppressed can be formed. (B) Cyrilized polyolefin is a component that imparts liquid repellency to the liquid repellent layer, but when only (B) Cyrilized polyolefin is added to (A) polyethylene resin, the liquid repellent layer formed is boiled. When heat treatment such as treatment is performed, the amorphous part of the polyethylene resin having a small molecular weight contained in the liquid-repellent layer on the inner surface of the pouch tends to swell due to fats and oils, and the oil contained in the contents is excessively absorbed by the polyethylene resin. As a result, an oil film was easily formed, and the liquid-repellent effect of the silicone portion of the (B) silylated polyolefin was reduced. On the other hand, the present inventors have found that the crystallinity and melting point of polyethylene can be controlled and the amount of oil swelling can be controlled by adding the (C) polyethylene / polypropylene block copolymer. Further, by controlling the amount of the (C) polyethylene / polypropylene block copolymer added, the degree of precipitation of Si in the (B) silylated polyolefin on the surface of the liquid-repellent layer when the liquid-repellent layer is formed is also controlled. We have found that we can.

Then, according to the resin composition for forming a liquid-repellent layer of the present invention, by adding the (C) polyethylene / polypropylene block copolymer, the amount of oil swelling of the liquid-repellent layer formed can be controlled and the liquid-repellent layer can be controlled. It is possible to achieve both improvement in the amount of Si present on the surface, and as a result, excellent liquid repellency can be obtained. Here, when the polyethylene / polypropylene block copolymer (C) is not added, the crystallinity and melting point of polyethylene are lowered, and Si is less likely to precipitate on the surface of the liquid-repellent layer due to the swelling of oil, and the liquid-repellent property is lowered. As a result, the amount of residual liquid will increase. When the amount of oil swelling in the liquid-repellent layer increases, the amount of residual liquid increases by that amount, and a large amount of oil and fat is segregated on the surface of the liquid-repellent layer. Will decrease and the amount of residual liquid will increase further. In this way, the absorption of oil content can be suppressed, the oil film is less likely to be formed, and the liquid-repellent layer can be efficiently imparted with liquid-repellent properties. This makes it possible to form a liquid-repellent layer having better liquid-repellent properties than when conventional silicone particles are used.

In the resin composition for forming a liquid-repellent layer, the mass ratio of the content of the (C) polyethylene / polypropylene block copolymer to the content of the (B) silylated polyolefin ((C) polyethylene / polypropylene block copolymer). (Mass of (B) silylated polyolefin) may be 0.1 to 20. When the content ratio is within the above range, the formed liquid-repellent layer can more sufficiently suppress the adhesion of the contents. Further, from the viewpoint of normal sealing property and contaminant sealing property, the mass ratio of the content of the (C) polyethylene / polypropylene block copolymer to the content of the (B) silylated polyolefin ((C) polyethylene / polypropylene block). The mass of the copolymer / the mass of the (B) silylated polyolefin) is preferably 0.1 to 5.

The present invention also provides a liquid-repellent film having a liquid-repellent layer formed by using the above-mentioned 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 by using the resin composition for forming the liquid-repellent layer of the present invention, adhesion of the contents to the liquid-repellent layer can be sufficiently suppressed. Can be done. Further, according to the above-mentioned liquid-repellent film, not only water and oil, but also curry, pasta sauce, Chinese seasoning, miso, spices, ketchup and other heat-treated contents such as retort and boil treatment. Good liquid repellency can be exhibited.

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 multilayer structure including a resin layer other than the liquid-repellent layer, it is possible to impart further functionality (heat resistance, impact resistance, etc.) in addition to the liquid-repellent property. In addition, the liquid-repellent layer can be thinned, and the cost can be reduced.

When the liquid-repellent film includes 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 resin layers of one or more layers. _{The melting point T 2} (° C.) of the resin contained in the resin layer in contact with the resin layer may satisfy the relationship of _{T 1} <T _2. By satisfying the above relationship, from the viewpoint of crystallinity, it is possible to prevent the (B) silylated polyolefin in the liquid-repellent layer from migrating to the resin layer in contact with the liquid-repellent layer among the one or more resin layers. Since the efficiency of uneven distribution or bleed-out of the (B) silylated polyolefin on the surface of the liquid-repellent layer can be improved, the liquid-repellent property tends to be further improved.

The present invention also comprises a base material and the liquid-repellent film of the present invention provided on the base material, and the liquid-repellent layer is arranged on at least one outermost surface of the liquid-repellent laminate. Provide the body. According to such a liquid-repellent laminate, the attachment of the contents to the liquid-repellent layer can be sufficiently suppressed by providing the liquid-repellent film of the present invention. Further, by laminating the liquid-repellent film with a base material having a desired function, it is possible to impart functions such as mechanical strength, barrier property, and light-shielding property to the liquid-repellent laminate.

The present invention also provides a packaging material formed by 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 by using the liquid-repellent laminate of the present invention, it is possible to sufficiently suppress the adhesion of the contents to the liquid-repellent layer.

The packaging material may be used for heat treatment at 60 ° C. to 100 ° C. According to the packaging material according to the present embodiment, even when it is used for such an application, it is possible to suppress the adhesion of the contents to the inner surface of the packaging material even after the heat treatment.

In addition, the liquid-repellent layer repels the contents during filling and packaging, so that the contents can be suppressed from being bitten during sealing, and good contaminant sealing properties can be imparted. Further, conventionally, such a packaging material contains a fatty acid amide such as erucic acid amide to impart slip property, but this fatty acid amide is accompanied by a decrease in sealing property, whereas in the present invention, it is substantially a fatty acid. It is possible to impart good slipperiness and normal sealing property even if it does not contain amide.

According to the present invention, a resin composition capable of forming a liquid-repellent layer capable of sufficiently suppressing adhesion of contents, and a liquid-repellent film, a liquid-repellent laminate, and a packaging material using the resin composition are provided. can do. Further, it is possible to provide a packaging material capable of imparting good contaminant sealing property, slipping property and normal sealing property at the time of filling and packaging.

It is the schematic sectional drawing of the liquid-repellent laminated body which concerns on one Embodiment of this invention. It is the schematic sectional drawing of the liquid-repellent laminated body which concerns on one Embodiment of this invention. It is a schematic diagram explaining the evaluation method of the liquid-repellent property of the liquid-repellent laminated body. It is a schematic diagram explaining the evaluation method of the liquid-repellent property of the liquid-repellent laminated body.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and duplicate description will be omitted. Moreover, the dimensional ratio of the drawing is not limited to the ratio shown in the drawing.

[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 the liquid-repellent layer is arranged on at least one of the outermost surfaces. Is. 1 and 2 are schematic cross-sectional views of the liquid-repellent laminate according to the present embodiment. In the liquid-repellent laminate according to the present embodiment, like the liquid-repellent laminate 1 shown in FIG. 1, the liquid-repellent film 10 made of the liquid-repellent layer 11 and the base material 14 are interposed via an adhesive 13. It may have a laminated structure. Further, the liquid-repellent laminate according to the present embodiment is a liquid-repellent film 10 composed of a liquid-repellent layer 11 and a second resin layer 12, and a base material, as in the liquid-repellent laminate 2 shown in FIG. 14 may have a structure in which the adhesive 13 is laminated. When the liquid-repellent film 10 includes the second resin layer 12, the liquid-repellent film 10 is based on the second resin layer 12 so that the liquid-repellent layer 11 is the outermost surface of the liquid-repellent laminate 2. It is arranged so as to face the material 14.

<Liquid repellent layer 11>
The liquid-repellent layer 11 is a layer having liquid-repellent properties. The liquid-repellent layer 11 may be a layer capable of exhibiting heat-sealing properties by heating. Here, the liquid repellency is a concept including both water repellency and oil repellency, and specifically, the property of repelling liquid, semi-solid, or gel water-based or oil-based materials. Is. Examples of water-based or oil-based materials include foods such as water, oil, yogurt, jelly, pudding, syrup, porridge, soup, curry, and pasta sauce, detergents such as hand soap and shampoo, pharmaceuticals, cosmetics, and chemicals. .. Further, the heat-sealing property means, for example, the property that heat-sealing is possible 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, further preferably 3 to 50 μm, and particularly preferably 5 to 30 μm. When the thickness of the liquid-repellent layer 11 is at least the above lower limit value, good liquid-repellent property and heat-sealing property tend to be easily obtained. On the other hand, when the thickness is not more than the above upper limit value, the thickness of the entire liquid-repellent laminate can be reduced.

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

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

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

((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, and ethylene-α-olefin copolymer. Examples of the α-olefin component include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene and the like.

Examples of the polyethylene resin include Novatec manufactured by Japan Polyethylene Corporation and Evolu manufactured by Prime Polymer Co., Ltd.

The melting point of the polyethylene resin can be appropriately adjusted according to the final application. For example, the melting point of the polyethylene resin is preferably 110 to 140 ° C. for heat resistant applications and 90 to 110 ° C. for low temperature sealing applications.

As the above-mentioned polyethylene resin, one type can be used alone or two or more types can be used in combination.

((B) Cyrilized polyolefin)
The silylated polyolefin is a component that imparts liquid repellency to the liquid repellent layer 11, and can also be used for improving the sealing property of impurities. Cyrilized polyolefin is a polyolefin unit having a silicone moiety.

Examples of the silylated polyolefin include products manufactured by Toray Dow Corning Co., Ltd. as PE-Si graft copolymers, Exfora manufactured by Mitsui Kagaku Fine Co., Ltd. as PE-Si block copolymers, and PP-Si graft copolymers. Examples of the coalescence include products manufactured by Toray Dow Corning Co., Ltd., and examples of PE-Si-PE triblock copolymers include Exfora manufactured by Mitsui Kagaku Fine Co., Ltd.

As the silylated polyolefin, a block copolymer is preferable to a graft copolymer from the viewpoint of further improving the liquid repellency of the liquid repellent layer 11. This is because the block copolymer tends to be unevenly distributed or bleed out on the surface of the liquid repellent layer 11.

The above-mentioned silylated polyolefin can be used alone or in combination of two or more.

((C) Polyethylene / Polypropylene Block Copolymer)
The (C) polyethylene / polypropylene block copolymer is a component having a portion compatible with (A) a polyethylene resin and a moiety compatible with the above (B) silylated polyolefin. By using the polyethylene / polypropylene block copolymer, it is possible to improve the compatibility between the (B) silylated polyolefin and the (A) polyethylene resin in which the polyolefin moiety is incompatible with the (A) polyethylene resin. Further, by adding the (C) polyethylene / polypropylene block copolymer, it is possible to suppress the absorption of oil content that occurs when heat treatment such as boiling treatment is performed, it becomes difficult for an oil film to be formed, and a liquid-repellent layer is formed. Can efficiently impart liquid repellency to polyethylene. Further, by adding the (C) polyethylene / polypropylene block copolymer, stable heat seal strength can be obtained as compared with the case where the copolymer is not added.

Examples of the portion compatible with the (A) polyethylene resin include a polyolefin structure compatible with the (A) polyethylene resin, and a portion having the same type of polyolefin structure as the (A) polyethylene resin is preferable. That is, it is preferable that the (C) polyethylene / polypropylene block copolymer has a polyethylene structure. When the (A) polyethylene resin is a copolymer composed of two or more types of olefins such as an ethylene-α olefin copolymer, the (C) polyethylene / polypropylene block copolymer constitutes the above-mentioned copolymer. Of the olefins, it is preferable to have at least a structure in which an olefin of the same type as the main component olefin is polymerized or copolymerized.

Examples of the moiety compatible with (B) the silylated polyolefin include a polyolefin structure compatible with (B) the polyolefin moiety of the silylated polyolefin, and (B) having the same type of polyolefin structure as the polyolefin moiety of the silylated polyolefin. It is preferably a site. That is, when the polyolefin moiety of (B) silylated polyolefin has a polyethylene structure, the (C) polyethylene / polypropylene block copolymer preferably has a polyethylene structure, and the polyolefin moiety of (B) silylated polyolefin has a polypropylene structure. If so, the (C) polyethylene / polypropylene block copolymer preferably has a polypropylene structure. Further, when the polyolefin moiety of the (B) silylated polyolefin has a structure based on a copolymer composed of two or more kinds of olefins such as an ethylene-α olefin copolymer and a propylene-α olefin copolymer, (C) The polyethylene / polypropylene block copolymer preferably has at least a structure obtained by polymerizing or copolymerizing an olefin of the same type as the main component olefin among the olefins constituting the copolymer.

That is, in the case of the (C) polyethylene / polypropylene block copolymer, if the polyolefin moiety of the (A) polyethylene resin or (B) silylated polyolefin is polyethylene, the moiety and the polyethylene moiety of the (C) polyethylene / polypropylene block copolymer If the polyolefin moiety of (B) silylated polyolefin is polypropylene, the moiety and (C) the propylene moiety of the polyethylene / polypropylene block copolymer are compatible.

The above-mentioned polyethylene / polypropylene block copolymer may be used alone or in combination of two or more.

The content of the component (A) in the liquid-repellent layer-forming resin composition is preferably 50.0 to 99.9% by mass, preferably 50.0 to 99.9% by mass, based on the total solid content of the liquid-repellent layer-forming resin composition. It is more preferably .0 to 99.0% by mass, and even more preferably 85.0 to 98.0% by mass. When the content of the component (A) is at least the above lower limit value, good heat sealability tends to be easily obtained. On the other hand, when the content of the component (A) is not more than the above upper limit value, the contents of the component (B) and the component (C) are relatively increased, so that the liquid repellency tends to be easily improved.

The total content of the components (B) and (C) in the liquid-repellent layer-forming resin composition is 0.1 to 30.0% by mass based on the total solid content of the liquid-repellent layer-forming resin composition. It is preferably 1.0 to 20.0% by mass, more preferably 2.0 to 15.0% by mass. When the total content of the component (B) and the component (C) is at least the above lower limit value, the liquid repellency tends to be improved easily. On the other hand, when the total content of the component (B) and the component (C) is not more than the above upper limit value, the content of the component (A) is relatively increased, so that good heat sealing property tends to be easily obtained. is there.

Mass ratio of the content of the component (C) to the content of the component (B) in the resin composition for forming a liquid-repellent layer (
The mass of the component (C) / the mass of the component (B)) is preferably 0.1 to 5.0. When the ratio of this content is at least the above lower limit value, the (B) silylated polyolefin can be sufficiently dispersed in the liquid repellent layer, and there is a tendency that better liquid repellent properties can be obtained. On the other hand, when the ratio of this content is not more than the above upper limit value, it is possible to prevent the (B) silylated polyolefin from being coated with the excess (C) polyethylene / polypropylene block copolymer, and to obtain better liquid repellency. Tend to get. Further, even if the (C) polyethylene / polypropylene block copolymer is added so that the content ratio exceeds the above upper limit value, the (B) silylated polyolefin is not dispersed any more, and the effect of improving the liquid repellency is improved. It tends to disappear.

The resin composition for forming a liquid-repellent layer may contain other additives, if necessary, as long as the liquid-repellent property is not impaired. Examples of other additives include flame retardants, slip agents, anti-blocking agents, antioxidants, light stabilizers, tackifiers and the like.

The liquid-repellent layer 11 can be formed by forming the above-mentioned resin composition for forming a liquid-repellent layer into a single layer or multiple layers.

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

The thermoplastic resin used for the second resin layer 12 is not particularly limited, but is a polyolefin resin, an ethylene-α, β unsaturated carboxylic acid copolymer or an esterified product thereof or an ionic crosslinked product, or an ethylene-vinyl acetate copolymer. Or its saponified product, polyvinyl acetate or its saponified product, polycarbonate resin, thermoplastic polyester resin, ABS resin, polyacetal resin, polyamide resin, polyphenylene oxide resin, polyimide resin, polyurethane resin, polylactic acid resin, furan resin, and silicone resin. And so on. These thermoplastic resins may be used alone or in combination of two or more.

The thermoplastic resin used for the second resin layer 12 preferably contains a polyolefin resin because heat sealability, heat resistance and impact resistance are likely to be improved. As the polyolefin resin, the same one as the polyethylene resin (A) 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 polyethylene resin (A) in the liquid repellent layer 11 and the thermoplastic resin in the second resin layer 12 It is preferable that the melting point T ₂ (° C.) _{satisfies the relationship of T 1} <T _2. By satisfying the above relationship, from the viewpoint of crystallinity, it is possible to suppress the migration of the (B) silylated polyolefin in the liquid repellent layer 11 to the second resin layer 12, and (B) to the surface of the liquid repellent layer 11. ) Since the efficiency of uneven distribution or bleed-out of the silylated polyolefin can be improved, the liquid repellency tends to be further improved. From the same viewpoint, the melting point T ₂ is preferably higher than the melting point T ₁ by 1 ° C. or higher, and more preferably 3 ° C. or higher.

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

<Liquid repellent film 10>
The liquid-repellent film 10 having liquid-repellent properties is formed by the above-mentioned single layer of the liquid-repellent layer 11 or the 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 a part or all of the surface of the base material 14. The liquid-repellent film 10 may be used alone without being laminated with the base material 14, depending on the intended use.

The liquid-repellent film 10 may further contain 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 serves as a support, and examples thereof include paper, a resin film, and a metal foil. Examples of the paper include high-quality paper, special high-quality paper, coated paper, art paper, cast-coated paper, imitation paper, kraft paper, and the like. Examples of the resin film include polyolefin (for example, polyethylene (PE), polypropylene (PP), etc.), acid-modified polyolefin, polyester (for example, polyethylene terephthalate (PET), etc.), polyamide (PA), polyvinyl chloride (PVC), cellulose acetate, and the like. Examples include films containing at least one of cellophane resins. This film may be a stretched film or a non-stretched film. Examples of the metal foil include aluminum foil and nickel foil. The base material 14 may be a laminate of a plurality of base materials having different materials.

The thickness of the base material 14 is not particularly limited and can be appropriately adjusted depending on the intended use, but is usually 1 to 500 μm, preferably 10 to 100 μm.

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

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

<Adhesive 13>
The adhesive 13 adheres the liquid-repellent film 10 and the base material 14. Examples of the adhesive 13 include a polyurethane resin obtained by reacting a main agent such as a polyester polyol, a polyether polyol, an acrylic polyol, and a carbonate polyol with a bifunctional or higher functional isocyanate compound. As the above-mentioned various polyols, one type can be used alone or two or more types can be used in combination.

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 the polyurethane resin described above for the purpose of promoting adhesion.

Further, various other additives and stabilizers may be added to the above-mentioned polyurethane resin according to the performance required for the adhesive 13.

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

(Laminating method by heat treatment)
Examples of the laminating method by heat treatment include the following methods.
(1) A method in which a liquid-repellent film 10 formed in advance is extruded and laminated on a base material 14 together with an adhesive resin.
(2) A method in which a resin layer constituting the liquid-repellent film 10 and an adhesive resin are extruded and laminated on a base material 14.
(3) A method of adhering the laminated base material obtained by the above method (1) or (2) by further heating and pressurizing with a heat roll.
(4) A method in which the laminated base material obtained by the above method (1) or (2) is further stored in a high temperature atmosphere, or passed through a drying / baking furnace in a high temperature atmosphere.

Examples of the adhesive resin used in the laminating method by heat treatment include acid-modified polyolefin. Further, in the above method, the base material 14 and the liquid-repellent film 10 are laminated by extrusion lamination, but the acid-modified polyolefin-based coating agent (dissolvable type, dispersion type) is previously applied to the base material without performing extrusion lamination. It is also possible to laminate the liquid-repellent film 10 by heat treatment after coating and forming on 14.

(Laminating method by extrusion laminating)
As a laminating method by extrusion laminating, an anchor coat layer is formed on the base material 14 in advance, and a single layer or two layers of molten liquid-repellent resin is directly extruded and laminated on the base material 14 on the anchor coat layer. Can be used. By forming this anchor coat layer, it is possible to improve the adhesion between the base material 14 and the liquid-repellent resin layer. An adhesive primer (anchor coat) can be provided on the base material 14, and the materials thereof include polyester, polyurethane, polyallylamine, polyethyleneimine, polybutadiene, ethylene-vinyl acetate copolymer, and the like. A chlorine-vinyl acetate system or the like can be used, and if necessary, the above-mentioned various curing agents and additives that can be used as the adhesive 13 may be blended.

The method of laminating by the above extrusion laminating may be extruded in a single layer, or may be coextruded with two or three kinds of resins, and a plurality of base materials may be attached at once by a sandwich laminating method or a tandem laminating method. It may be a method of matching.

[Packaging material]
The packaging material according to the present embodiment is formed by using the above-mentioned liquid-repellent laminate. Specifically, as a packaging material, heat treatment such as lid material for containers such as yogurt, jelly, syrup, porridge, soup, curry, pasta sauce, Chinese seasoning, miso, spices, ketchup, etc. Examples include food packaging materials to be used. By forming the packaging material so that the liquid-repellent layer is arranged on the inner surface (content side) of the packaging material, it is possible to prevent the contents such as liquids, semi-solids, and gel-like substances from adhering to and remaining on the inner surface of the packaging material. can do. Further, in a bag-shaped packaging material such as a retort food packaging material, the contents may be difficult to be discharged due to blocking between the innermost layers of the packaging material. However, according to the packaging material according to the present embodiment. , The innermost liquid-repellent layers are less likely to block each other, and the contents can be efficiently discharged.

The packaging material may be used for heat treatment at 60 to 100 ° C. Specifically, it may be used for a packaging material to be heat-treated such as a water bath such as a retort food packaging material. According to the packaging material according to the present embodiment, even when it is used for such an application, it is possible to suppress the adhesion and residue of the contents on the inner surface of the packaging material even after the heat treatment.

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

[Examples 1 to 15; Configuration example 1]
<Preparation of resin composition for forming a liquid-repellent layer>
Linear low-density polyethylene (LLDPE, 0.92 g / cm ³ ) as a component (A) and silylated polyethylene (PE-Si graft copolymer, manufactured by Toray Dow Corning Co., Ltd.) as a component (B) Or, a PE-Si block copolymer, trade name "IXFOLA", manufactured by Mitsui Kagaku Fine Co., Ltd.) and a PP-PE block copolymer, which is a component (C), are mixed (B). ) And the type and content of the component (C) were changed as shown in Table 1, and the balance was adjusted to be the component (A) to prepare a resin composition for forming a liquid-repellent layer.

<Preparation of liquid-repellent laminate>
A resin composition for forming a liquid-repellent layer was extruded and formed into a film using a three-layer co-extruder to obtain a liquid-repellent film composed of a liquid-repellent layer having a thickness of 60 μm. The obtained liquid-repellent film and a 38 μm-thick PET film (trade name “Emblet”, manufactured by Unitika Co., Ltd.), which is a base material, are 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 16 to 19; Configuration Example 2]
<Preparation of resin composition for forming a liquid-repellent layer>
In Examples 16 to 19, linear low-density polyethylene (LLDPE, 0.90 g / cm ³ ) as the component (A) is used, and the other components (B) and (C) are the same as those of the first component. The type and content of the component (B) and the component (C) were changed as shown in Table 2 and adjusted so that the balance was the component (A). Was produced.

<Preparation of liquid-repellent laminate>
A linear low-density polyethylene (LLDPE, 0.92 g / cm ³ ) as a component (A) was used as a second liquid-repellent layer-forming resin composition. However, as shown in Table 2, adjustments were made at two points: one having a melting point equivalent to that of the first resin layer and one having a melting point higher than that of the first resin layer. An anchor coat layer is formed in advance on a 38 μm-thick PET film (trade name “Emblet”, manufactured by Unitika Ltd.), which is a base material, and the first and second liquid repellent layers melted on the anchor coat layer. The forming resin composition was directly extruded onto a PET film and laminated, and aged at 50 ° C. for 2 days to obtain a liquid-repellent laminate. The thickness of the liquid-repellent layer was set to 15 μm, and the thickness of the second resin layer was set to 45 μm, and the film was formed.

A film was formed by the method shown in Configuration Example 1 according to the composition shown in Table 3, and each of the following comparative examples was prepared.

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

[Comparative Example 2]
The resin composition for forming a liquid-repellent layer is the same as in Example 1 except that the resin composition for forming a liquid-repellent layer is only LLDPE to which 2% of erucic acid amide (slip agent), which is a component (A), is added. , A liquid-repellent film and a liquid-repellent laminate were prepared.

[Comparative Example 3]
A resin composition for forming a liquid-repellent layer, a liquid-repellent film, and a liquid-repellent laminate were produced in the same manner as in Example 6 except that the component (B) was not added to the resin composition for forming a liquid-repellent layer.

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

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

[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 14 except that the component (C) was homo-PP.

The details of each component in Table 1, Table 2 and Table 3 are as follows. "-" In the table means that the corresponding ingredient was not used. Further, in Tables 1, 2 and 3, the mass ratio of the content of the component (C) to the content of the component (B) in the liquid repellent layer (mass of the component (C) / mass of the component (B)). showed that. Further, Table 2, was used in liquid-repellent layer (A) melting point T ₁ (° C.) of the resin as the component and the second was used for the resin layer (A) melting point of the resin as the component T _{2 (°} C. ) Is shown.

[(A) Polyethylene resin]
A1: Linear low density polyethylene (LLDPE), density: 0.92 g / cm ³
A2: Linear low density polyethylene (LLDPE), density: 0.91 g / cm ³
A3: Linear low density polyethylene (LLDPE), density: 0.90 g / cm ³

[(B) Cyrilized polyolefin]
B1: PE-Si graft copolymer, manufactured by Toray Dow Corning Co., Ltd. B2: PE-Si block copolymer, trade name "Ixfora", manufactured by Mitsui Kagaku Fine Co., Ltd. B3: PP-Si graft Copolymer, manufactured by Toray Dow Corning Co., Ltd.

[(C) Polyethylene / Polypropylene copolymer]
C1: Block copolymer of propylene and ethylene

[Evaluation of liquid repellency]
<Liquid repellent after boiling>
For Examples and Comparative Examples, the liquid repellency after the boiling treatment was evaluated 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 length of 150 mm and a width of 138 mm. Two samples 200 are stacked so that their respective liquid-repellent layers are on the inside, and one side of the vertical end and two sides of both ends in the horizontal direction are placed on each side with a heat sealer at 190 ° C., 0.03 MPa, 2 sec. Under the conditions, a seal portion 51 was formed by heat-sealing over a width of 10 mm to prepare a pouch 50 having one side open at the vertical end (see (a) in FIG. 3).
Next, 100 g of salad oil 54 (trade name “Nissin Salad Oil”, manufactured by Nissin Oillio Co., Ltd.) was injected through the opening of the pouch (see (b) in FIG. 3).
Then, the opening was heat-sealed with a heat sealer at 190 ° C., 0.03 MPa, and 2 sec over a width of 10 mm to form a seal portion 51, the pouch 50 was sealed, and a boil treatment was performed in a pot 52 by boiling water (boil treatment). See (c) in FIG. 3).

In the boil treatment, the sealed pouch 50 was boiled at 85 ° C. for 30 minutes, then returned to room temperature, and the upper part of the sealed pouch 50 was cut to form a spout. Next, holding the pouch 50 upside down for 30 seconds with the seal portion on the opposite side of the spout, the vegetable oil 54 was discharged into the container 56, and the discharge amount was weighed by the scale 57 ((d) in FIG. 3). reference).
From the weighed discharge amount, the residual liquid amount (%) was calculated by the following formula.
Residual liquid amount (%) = {(100-discharge amount) / 100} x 100
The measurement was performed three times, and the liquid repellency was evaluated from the average residual liquid amount of the three times according to the following evaluation criteria. Tables 1 and 2 show the evaluation results of the average residual liquid amount (%) and 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% Δ: 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

<Liquid repellency without heat treatment>
The liquid repellency of Examples and Comparative Examples was evaluated 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 length of 150 mm and a width of 138 mm. Two samples 100 are stacked so that their respective liquid-repellent layers are on the inside, and one side of the vertical end and two sides of both ends in the horizontal direction are placed on each side with a heat sealer at 190 ° C., 0.03 MPa, 2 sec. Under the conditions, a seal portion 61 was formed by heat sealing over a width of 10 mm to prepare a pouch 60 having an opening on one side of the vertical end portion (see (a) in FIG. 4).
Next, 100 g of salad oil 54 (trade name “Nissin Salad Oil”, manufactured by Nissin Oillio Co., Ltd.) was injected through the opening of the pouch 60 (see (b) in FIG. 4).
Next, the pouch 60 was held upside down for 30 seconds with the seal portion on the opposite side of the opening, the vegetable oil 54 was discharged into the container 56, and the discharge amount was weighed by the scale 57 ((c) of FIG. 4). See).
From the weighed discharge amount, the residual liquid amount (%) was calculated by the following formula.
Residual liquid amount (%) = {(100-discharge amount) / 100} x 100
The measurement was performed three times, and the liquid repellency was evaluated from the average residual liquid amount of the three times according to the following evaluation criteria. The evaluation results of the average residual liquid amount (%) and the liquid repellency are shown in Tables 3 and 4.
⊚: Average residual liquid amount is less than 1.5% ○: Average residual liquid amount is 1.5% or more and less than 2.0% Δ: 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 above liquid repellency evaluation, the liquid discharge behavior when the liquid was discharged from the pouch was visually observed, and the appearance was evaluated according to the following evaluation criteria. The results are shown in Tables 1 to 3.
⊚: It can be seen that it slides down cleanly and does not adhere to the liquid-repellent laminate.
◯: It seems that it slides down, and there is little adhesion to the liquid-repellent laminate.
Δ: It seems that it slides down, but it adheres to the liquid-repellent laminate.
×: No sign of sliding down.

[Measurement of swelling amount]
The amount of swelling was measured by the following procedure. The results are shown in Tables 1 to 3.
(1) At the time of the above-mentioned evaluation of residual liquid property, the weight of the empty pouch before filling with the contents is measured.
(2) The pouch after the residual liquid property evaluation is washed with a food detergent, the inside of the pouch is wiped with isopropyl alcohol, and the weight of the pouch is measured.
(3) Calculate the amount of swelling using the following formula. (Number of samples n = 3)
Swelling amount (%) = (pouch weight of (2)-pouch weight of (1)) ÷ pouch weight of (1)

[Normal seal strength measurement]
The seal piece was sealed with a heat sealer under the following conditions, the seal piece was cut into a width of 15 mm, and the measurement was performed using Tencilon manufactured by Shimadzu Corporation at a peeling angle of 90 °. The sample preparation and measurement method was performed based on the JIS standard (Z 0238: 1998). Evaluation is performed according to the following evaluation criteria, and the results are shown in Tables 1 to 3.
Seal bar: Heat only the upper surface seal bar Seal temperature: 140 ° C
Sealing pressure: 0.3MPa
Sealing time: 1.0 sec
◯: 50N / 15mm or more Δ: 40N / 15mm or more, less than 50N / 15mm ×: less than 40N / 15mm

[Measurement of contaminant seal strength]
A sample for measuring the contaminant seal was prepared by the following procedure.
(1) Apply salad oil to the sealing surface (liquid repellent layer 11) of the liquid repellent film with a cotton swab.
(2) Put salad oil from above with another liquid-repellent film, seal it with a heat sealer, and measure the seal strength.
The measurement conditions and measurement method are the same as those for the normal seal strength measurement. The strength is evaluated according to the following evaluation criteria, and the results are shown in Tables 1 to 3.
◯: 40N / 15mm or more Δ: 35N / 15mm or more, less than 40N / 15mm ×: less than 35N / 15mm

[Static / dynamic friction coefficient measurement]
The static and dynamic friction coefficients were measured under the following conditions using a surface measuring instrument manufactured by Shinto Kagaku Co., Ltd. The sample preparation and measurement method was performed based on the JIS standard (K 7125: 1999). The strength is evaluated according to the following evaluation criteria, and the results are shown in Tables 1 to 3.
Movement speed: 100 mm / min
Measurement distance: 60 mm
Load cell: 20N
Moving weight: 200g
◯: Less than 0.5 (μs or μD) ×: 0.5 (μs or μD) or more

As is clear from the results shown in Tables 1 to 3, the liquid-repellent laminates of Examples 1 to 19 have a liquid-repellent property as compared with the liquid-repellent laminates of Comparative Examples 1 to 6. It was confirmed that it can be improved.

Further, liquid repellent laminates of Examples 18 and 19, the melting point T ₁ of the resin in the liquid-repellent layer and the melting point T ₂ of the resin of the second resin layer is satisfy the relationship T _{1 <T 2} It was found that particularly good liquid repellency was obtained.

Further, it was confirmed that those having a small change in the weight of the pouch before and after the evaluation of the residual liquid, that is, those having a small absorption of oil and a small amount of swelling tended to show high liquid repellency.

1, 2 ... Liquid-repellent laminate 10 ... Liquid-repellent film 11 ... Liquid-repellent layer 12 ... Second resin layer 13 ... Adhesive 14 ... Base materials 50, 60・ ・ ・ Pouch 51, 61 ・ ・ ・ Seal part 52 ・ ・ ・ Pot 54 ・ ・ ・ Salad oil 56 ・ ・ ・ Container 57 ・ ・ ・ Scale 100, 200 ・ ・ ・ Sample for evaluation of liquid-repellent laminate

Claims (11)

A resin composition for forming a liquid-repellent layer, which comprises (A) a polyethylene resin, (B) a silylated polyolefin, and (C) a polyethylene / polypropylene block copolymer. Mass ratio of the content of the (C) polyethylene / polypropylene block copolymer to the content of the (B) silylated polyolefin (mass of (C) polyethylene / polypropylene block copolymer / mass of (B) silylated polyolefin ) Is 0.1 to 20, the resin composition for forming a liquid-repellent layer according to claim 1. The resin composition for forming a liquid-repellent layer according to claim 1 or 2, wherein the content of the (B) silylated polyolefin is 1 to 10% by mass with respect to the resin composition for forming a liquid-repellent layer. The resin composition for forming a liquid-repellent layer according to claim 1 or 2, wherein the polyethylene / polypropylene block copolymer (C) is 1 to 5% by mass with respect to the resin composition for forming a liquid-repellent layer. A liquid-repellent film comprising a liquid-repellent layer formed by using the resin composition for forming a liquid-repellent layer according to any one of claims 1 to 4. The liquid-repellent film according to claim 5, further comprising one or more resin layers provided on one main surface of the liquid-repellent layer. _{The melting point T 1} (° C.) of the polyethylene resin (A) in the _{liquid repellent layer and the melting point T 2} (° C.) of the resin contained in the resin layer in contact with the liquid repellent layer among the one or more resin layers. The liquid-repellent film according to claim 6, wherein the liquid-repellent film satisfies the relationship of _{T 1} <T _2. A base material and the liquid-repellent film according to any one of claims 5 to 7 provided on the base material are provided, and the liquid-repellent layer is arranged on at least one outermost surface. Liquid-repellent laminate. A packaging material using the liquid-repellent laminate according to claim 8, wherein the liquid-repellent layer is formed so as to be the innermost layer. The packaging material according to claim 9, wherein the packaging material is used for heat treatment at 60 ° C. to 100 ° C. The packaging material according to claim 9, which has a contaminant sealing property for the contents.

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