JP7326909B2 - Liquid-repellent laminate and packaging material - 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. A composite laminate of a material or the like and a plastic substrate, and a composite obtained by treating a plastic substrate with a functional composition have been proposed.

As one of the high functions described above, for example, a function to suppress adhesion of contents such as liquids, semi-solids, and gel substances to the inner surface of the packaging material, that is, to suppress the residue inside the packaging body 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 storage containers, and it is not possible to use up all the contents, resulting in waste. In order to prevent the need for time and labor, the inner surface is required to have excellent liquid repellency so that the contents are less likely to adhere and easily slide off.

In response to these demands, for example, Patent Document 1 discloses a water-repellent film having an uneven structure on the surface, the surface having the uneven structure has a predetermined surface roughness Ra, and the surface having the uneven structure is resistant to water. A water-repellent film has been proposed that has a predetermined contact angle. Further, Patent Document 2 proposes a resin sheet containing a polyolefin and a silicone-olefin copolymer, wherein at least one of the front surface and the back surface has an arithmetic mean roughness Ra within a predetermined range.

JP 2015-025053 A JP 2017-206587 A

However, just by defining the surface roughness of the liquid-repellent layer as in the technique disclosed in Patent Document 1, sufficient water repellency cannot be obtained. In addition, in the technique disclosed in Patent Document 2, a silicone-olefin copolymer is added to polyolefin, but the silicone-olefin copolymer aggregates in the resin layer, and the silicone-olefin copolymer is uniform in the resin layer. Since it is difficult to disperse, sufficient water repellency cannot be obtained.

The present invention has been made in view of the above-described problems of the prior art, and provides a resin composition capable of forming a liquid-repellent layer having excellent liquid repellency to which contents are difficult to adhere and to easily slide off, and a resin composition containing the same. An object of the present invention is to provide a liquid-repellent film, a liquid-repellent laminate, and a packaging material used.

In order to achieve the above objects, the present invention contains (A) a polyolefin resin and (B) a silicone-acrylic copolymer, and the content of (B) the silicone-acrylic copolymer is a liquid-repellent layer. Provided is a liquid-repellent layer-forming resin composition having a solid content of 0.5 to 20% by mass based on the total solid content of the forming resin composition.

According to the liquid-repellent layer-forming resin composition, (A) a polyolefin resin and (B) a silicone-acrylic copolymer, which is a component that imparts liquid repellency to the liquid-repellent layer, are used in combination, and (B ) The content of the silicone-acrylic copolymer is 0.5 to 20% by mass based on the total solid content of the liquid-repellent layer-forming resin composition. They speculate as follows. When the silicone-acrylic copolymer (B) is added to the polyolefin resin (A), the acrylic portion of the silicone-acrylic copolymer (B) is compatible with the polyolefin resin (A), resulting in excellent dispersibility. In addition, the silicone portion tends to be unevenly distributed on the surface of the liquid-repellent layer, and excellent liquid-repellency can be imparted to the obtained liquid-repellent layer. In addition, by setting the content of the silicone-acrylic copolymer (B) within the above range, when the liquid-repellent layer is formed, the silicone-acrylic copolymer (B) tends to be highly dispersed without aggregating with each other. Therefore, the resulting liquid-repellent layer has excellent liquid-repellent properties that prevent the content from adhering to the layer and easily slide off.

(B) The silicone-acrylic copolymer may have an average particle size of 100 to 500 μm. When the average particle size of the silicone-acrylic copolymer (B) is within the above range, the liquid-repellent layer is more likely to form unevenness on the surface more efficiently, and the liquid-repellent property can be further improved.

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. Moreover, the liquid-repellent film can exhibit good liquid repellency not only to water and oil, but also to oil-in-water dispersion type contents such as curry and pasta sauce.

In the liquid-repellent film, the liquid-repellent layer may have an arithmetic mean roughness Ra of 0.1 μm or more. When the arithmetic mean roughness Ra of the liquid-repellent layer is within the above range, the surface of the liquid-repellent layer has unevenness with sufficient roughness. Therefore, even when the contents are in contact with the liquid-repellent layer, the contact area with the contents can be reduced, and more excellent liquid repellency can be obtained.

The static friction coefficient of the liquid-repellent layer may be 0.40 or less. When the coefficient of static friction of the liquid-repellent layer is within the above range, contents in contact with the liquid-repellent layer easily slide down, and more excellent liquid repellency can be obtained.

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 polyolefin 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) silicone-acrylic copolymer in the liquid-repellent layer can be suppressed from migrating to the second resin layer, and the (B) to the surface of the liquid-repellent layer can be suppressed. ) Since the uneven distribution or bleeding out efficiency of the silicone-acrylic copolymer 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, since the liquid-repellent film of the present invention is provided, it is difficult for the contents to adhere to the liquid-repellent layer and the contents easily slide off. 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. According to such a packaging material, since it is formed using the liquid-repellent laminate of the present invention, contents are less likely to adhere to the liquid-repellent layer and easily slip off.

The packaging material may be used for applications where heat treatment at 80° C. or higher is performed. According to the packaging material according to the present embodiment, even when used for such purposes, contents are less likely to adhere to the inner surface of the packaging material even after the heat treatment, and are likely to slide down.

INDUSTRIAL APPLICABILITY According to the present invention, a resin composition capable of forming a liquid-repellent layer having excellent liquid repellency to which contents are difficult to adhere and easily slide off, a liquid-repellent film using the same, a liquid-repellent laminate, and Packaging can be provided.

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.

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.

In the present specification, liquid repellency means the property of repelling liquid to prevent it from adhering to the liquid repellent layer, and the ability to quickly slide off the liquid adhering to the liquid repellent layer and prevent it from remaining in place (does not maintain the adhered state). ) include nature.

[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. 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 such 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 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-repellent properties and heat-sealing properties 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 arithmetic mean roughness Ra of the liquid-repellent layer 11 is preferably 0.1 μm or more, more preferably 0.15 μm or more, more preferably 0.1 μm or more, in order to further improve the liquid-repellency of the liquid-repellent layer 11 . It is more preferably 2 μm or more. The arithmetic mean roughness Ra of the liquid-repellent layer 11 is not particularly limited, but may be 5.0 μm or less. The arithmetic average roughness Ra of the liquid-repellent layer 11 can be measured using a non-contact surface/cross-sectional shape measurement system Vert Scan (manufactured by Ryoka Systems Co., Ltd., model number: R3300FL-Lite-AC).

The arithmetic mean roughness Ra of the liquid-repellent layer 11 can be adjusted within the above range by forming unevenness on the surface of the liquid-repellent layer 11 . Examples of methods for forming surface unevenness on the liquid-repellent layer 11 include methods such as shape transfer and filler addition. Also, by using (B) a silicone-acrylic copolymer having a predetermined average particle diameter as described later, it is possible to form moderate irregularities on the surface of the liquid-repellent layer 11, and The average roughness Ra can be adjusted within the above range.

The upper limit of the coefficient of static friction of the liquid-repellent layer 11 is preferably 0.40 or less, more preferably 0.35 or less, in order to further improve the liquid-repellent property of the liquid-repellent layer 11. 0.30 or less is more preferable. The lower limit of the coefficient of static friction of the liquid-repellent layer 11 is not particularly limited, but may be, for example, 0.20 or more. The coefficient of static friction of the liquid-repellent layer 11 can be measured using a friction measuring instrument (manufactured by Toyo Seiki Seisakusho Co., Ltd. Model No. TR-2).

When the arithmetic mean roughness Ra of the liquid-repellent layer 11 is 0.1 μm or more, the upper limit of the coefficient of static friction of the liquid-repellent layer 11 is preferably 0.40 or less, and preferably 0.35 or less. is more preferable, and 0.30 or less is even more preferable. In such a case, since the arithmetic mean roughness Ra is 0.1 μm or more, the area of the contact portion between the liquid-repellent layer 11 and the contents can be reduced, and the static friction coefficient is 0.40 or less. As a result, it is possible to improve the sliding property of the contact portion with a reduced area. As a result, the liquid-repellent layer 11 can obtain even more excellent liquid repellency.

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>
The resin composition for forming a liquid-repellent layer according to one embodiment of the present invention comprises (A) a polyolefin resin (hereinafter also referred to as "(A) component"), (B) a silicone-acrylic copolymer (hereinafter referred to as "( (also referred to as "component B)"), and the content of (B) the silicone-acrylic copolymer is 0.5 to 20% by mass based on the total solid content of the liquid-repellent layer-forming resin composition. .

((A) polyolefin resin)
Component (A) includes polyethylene, polypropylene, polynorbornene, and the like. Component (A) may be a linear polyolefin from the viewpoint of sealability and strength properties (tensile strength, impact strength, etc.), and the linear polyolefin may be linear or branched. When the liquid-repellent laminate is used as a packaging material that is subjected to heat treatment such as boiling in hot water, such as retort food packaging, it prevents the bag-shaped packaging material from breaking due to heat treatment such as boiling in hot water. Component (A) is preferably polypropylene because it is easy to handle. (A) component can be used individually by 1 type or in combination of 2 or more types.

Examples of polyethylene include low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, and the like. Examples of α-olefin components include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 4-methyl-1-pentene. The copolymer may be a random copolymer or a block copolymer.

Examples of polypropylene include homopolypropylene, block polypropylene, random polypropylene, modified polypropylene, and copolymers of propylene and α-olefins other than ethylene and propylene (propylene-based copolymers). When polypropylene is used as component (A), it is preferable to use a combination of block polypropylene and random polypropylene from the viewpoint that component (B) tends to be unevenly distributed on the surface of the formed liquid-repellent layer and the liquid repellency is further improved. .

When block polypropylene and random polypropylene are used in combination as polypropylene, the mass ratio of block polypropylene and random polypropylene (block polypropylene/random polypropylene) is preferably 20/80 to 80/20, preferably 40/60 to 60. /40 is more preferred. When the mass ratio is equal to or higher than the above lower limit, the component (B) tends to be unevenly distributed on the surface of the formed liquid-repellent layer, and the liquid-repellent property is further improved.

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

The melting point of the polyolefin resin can be appropriately adjusted depending on the end use. For example, for retort food packaging applications, the polyolefin resin preferably has a melting point of 130 to 170°C.

((B) silicone-acrylic copolymer)
The component (B) is a component that imparts liquid repellency to the liquid repellent layer 11 . A silicone-acrylic copolymer has an acrylic portion and a silicone portion. (B) component can be used individually by 1 type or in combination of 2 or more types.

The silicone-acrylic copolymer may be a block copolymer or a random copolymer.

Component (B) includes, for example, Chaline R-170, Chaline M-175PP, Chaline R-175S (manufactured by Nissin Chemical Industry Co., Ltd., trade names), Modiper FS700 (trade name, manufactured by NOF Corporation). and other products.

The average particle diameter of the component (B) is preferably 10 to 500 μm, because the dispersibility of the component (B) is further improved and the liquid repellency can be efficiently imparted to the formed liquid repellent layer. preferable. Average particle size can be measured by a laser diffraction/scattering method.

In the component (B), the copolymerization ratio (molar ratio) of the component that constitutes the acrylic portion and the component that constitutes the silicone portion is 10:10 from the viewpoint of imparting liquid repellency by the silicone portion and imparting dispersibility by the acrylic portion. It is preferably 90 to 70:30, more preferably 30:70 to 50:50.

The content of component (A) in the liquid-repellent layer-forming resin composition is preferably 80 to 99.5% by mass, preferably 85 to 97%, based on the total solid content of the liquid-repellent layer-forming resin composition. 0.5 mass % is more preferred, and 90 to 95 mass % is even more preferred. When the content of component (A) is at least the above lower limit, good heat-sealability tends to be obtained. On the other hand, when the content of component (A) is equal to or less than the above upper limit, the content of component (B) is relatively increased, so that the liquid repellency tends to be easily improved.

The content of component (B) in the liquid-repellent layer-forming resin composition is 0.5 to 20% by mass, and 2.5 to 15% by mass, based on the total solid content of the liquid-repellent layer-forming resin composition. %, more preferably 5 to 10% by mass. When the content of the component (B) is at least the above lower limit, the liquid repellency tends to be improved. On the other hand, if the content of the component (B) is less than the above upper limit, the components (B) are unlikely to agglomerate when the liquid-repellent layer is formed, so the liquid repellency tends to be improved.

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. By further including the second resin layer in the liquid-repellent film, it becomes possible to impart further functionality (heat resistance, impact resistance, etc.) in addition to the liquid repellency. In addition, since the liquid-repellent layer can be made thinner and the total amount of component (B) contained in the liquid-repellent layer can be reduced, cost reduction is also possible. 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 one as the component (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 component (A) in the liquid-repellent layer 11 and the melting point of the thermoplastic resin in the second resin layer 12 T ₂ (° C.) preferably satisfies the relationship of T ₁ <T ₂ . By satisfying the above relationship, the component (B) in the liquid-repellent layer 11 can be suppressed from migrating to the second resin layer 12 from the viewpoint of crystallinity, and the component (B) to the surface of the liquid-repellent layer 11 can be suppressed. can improve the uneven distribution or bleed-out efficiency, so there is a tendency that the liquid repellency can 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.

Here, the melting point _T1 is the melting point of the component (A) measured in the liquid-repellent layer 11 using the liquid-repellent layer 11 as a measurement sample. Similarly, the melting point _T2 is the melting point of the resin measured in the second resin layer 12 using the second resin layer 12 as a measurement sample. The melting point _T1 indicates the melting point of the polyolefin resin that melts at the lowest temperature in the liquid-repellent layer 11 when the liquid-repellent layer 11 contains two or more polyolefin resins having different melting points as the component (A). Because it is affected by other polyolefin resins, it differs from the melting point measured for polyolefin resin alone. The melting point T1 of the component (A) in the liquid-repellent layer ₁₁ and the melting point _T2 of the resin in the second resin layer 12 are measured by a thermal analyzer (for example, TA7000 manufactured by Hitachi High-Tech Science Co., Ltd.). be able to.

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 a 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 a 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.

In the liquid-repellent laminate according to the present embodiment, the liquid-repellent laminate is formed in the shape of a bag so that the liquid-repellent layer is on the inner surface. The amount of oil swelling per unit area of the liquid-repellent laminate is 1.0 mg/cm ² or less after being subjected to heat and pressure treatment with water vapor under conditions of 121° C., pressure of 0.2 MPa, and 30 minutes. preferable. When the oil swelling amount measured in this way is 1.0 mg/cm ² or less, the liquid-repellent laminate can have more excellent liquid repellency, and the residual liquid after the contents are discharged. The amount can be further reduced. From the same point of view, the oil swelling amount is more preferably 0.95 mg/cm ² or less. On the other hand, the liquid-repellent layer may swell to some extent with oils and fats from the viewpoint of improving the slideability of the contents, and the oil swelling amount may be 0.5 mg/cm ² or more.

[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 applications where heat treatment at 80° C. or higher is performed. 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.

[container]
The container according to the present embodiment is a container having at least the inner surface (on the content side) a liquid-repellent layer formed using the liquid-repellent layer-forming resin composition described above. Specific examples of containers include storage containers for liquids such as chemicals and pharmaceuticals, semi-solids, and gel-like substances, and bottles for containing hand soaps, shampoos, and the like. By forming the container so that the liquid-repellent layer is arranged on the inner surface of the container (on the content side), 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 container. can.

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.

<Preparation of resin composition for forming liquid-repellent layer>
[Examples 1 to 30 and Comparative Examples 1 to 4]
As component (A), random polypropylene resin (propylene-ethylene random copolymer, trade name “Prime Polypro F744NP”, manufactured by Prime Polymer Co., Ltd.) and block polypropylene resin (propylene-ethylene block copolymer, trade name “Prime Polypro BC5FA”) and one of (B1) to (B5) shown in Table 1 as the component (B) were mixed to prepare a resin composition for forming a liquid-repellent layer. Here, the content of each component is such that the mass ratio of the random polypropylene resin and the block polypropylene resin in the component (A) is 50:50, and the composition of the component (A) and the component (B) is shown in Table 1. Adjusted to be the ratio shown in . Details of (B1) to (B5) are as follows.

(B1): Silicone-acrylic copolymer (trade name “Modiper FS700”, manufactured by NOF Corporation)
(B2): Silicone-acrylic copolymer (average particle size 350 μm (catalog value), trade name “Charine R-170”, manufactured by Nissin Chemical Industry Co., Ltd.)
(B3): Fluorine compound (average particle size 6 μm, trade name “CERAFLOUR 996”, manufactured by BYK-Chemie Japan Co., Ltd.)
(B4): Silylated polyolefin resin (trade name “Exfola”, manufactured by Mitsui Chemicals Fine Co., Ltd.)
(B5): Silicone-acrylic copolymer (trade name “Charine M-175PP”, manufactured by Nissin Chemical Industry Co., Ltd.)
(B5) is a masterbatch composed of a silicone-acrylic copolymer and a block polypropylene resin, and the ratio of the silicone-acrylic copolymer to the entirety of (B5) is 50% by mass. Therefore, in Table 1, in addition to the total blending amount of (B5), the blending amount (% by mass) of only the silicone-acrylic copolymer is shown in parentheses for the examples using (B5). In addition, the polypropylene resin which comprises a masterbatch corresponds to (A) component.

<Preparation of liquid-repellent laminate>
[Examples 1 to 10]
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 60 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 11 to 20 and Comparative Examples 1 to 4]
Random polypropylene resin (propylene-ethylene random copolymer, trade name “Prime Polypro F744NP”, manufactured by Prime Polymer Co., Ltd.) and block polypropylene resin (propylene-ethylene block copolymer, trade name “Prime Polypro BC5FA”) No. 2 resin composition for resin layer formation. Here, the resin composition for forming the second resin layer was adjusted so that the mass ratio of the random polypropylene resin and the block polypropylene resin was 50:50. 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 45 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.

[Examples 21 to 30]
Examples 11 to 20 and Comparative Examples 1 to 4, except that a block polypropylene resin (propylene-ethylene block copolymer, trade name “Prime Polypro BC3HF”) was used as the resin composition for forming the second resin layer. A liquid-repellent laminate was produced in the same manner.

<Measurement of arithmetic mean roughness Ra>
[Examples 1 to 30 and Comparative Examples 3 and 4]
The arithmetic mean roughness Ra of the liquid-repellent layer was measured using a non-contact surface/cross-sectional shape measurement system Vert Scan (manufactured by Ryoka Systems Co., Ltd., model number: R3300FL-Lite-AC). Measurement conditions were as follows: magnification of the objective lens was 5×, mode was Phase, scan range was −10 to 10 μm, and field size was 640×480 μm. Table 1 shows the measurement results.

<Measurement of Static Friction Coefficient>
[Examples 1 to 30 and Comparative Examples 1 to 4]
The static friction coefficient of the liquid-repellent layer was measured using a friction measuring machine (manufactured by Toyo Seiki Seisakusho Co., Ltd., Model No. TR-2). The liquid-repellent laminate obtained in each example was cut into a size of 100 mm long×70 mm wide to obtain a test piece. The obtained test piece was attached to a weight for measurement so that the liquid-repellent layer was on the outside. As a test piece to be attached to the main body of the measuring instrument, the liquid-repellent laminate obtained in each example was cut into a size of 160 mm long and 100 mm wide. The obtained test piece was attached to the main body of the measuring machine so that the liquid-repellent layer was on the outside. A weight was placed so that the liquid-repellent layer of the test piece attached to the measuring instrument main body and the liquid-repellent layer of the test piece attached to the weight for measurement were in contact with each other. The static friction coefficient was measured by rubbing the test pieces against each other with a weight of 200 g and a measurement speed of 100 mm/min. A measurement distance was 60 mm, and a load cell of 20 N was used.

Table 1 also shows the melting point T ₁ (°C) of the resin that is the component (A) measured in the liquid-repellent layer and the melting point T ₂ of the resin that is the component (A) used in the second resin layer. (°C). The melting point _T1 indicates the melting point of the random polypropylene resin that melts at a lower temperature in the liquid-repellent layer, but is affected by the block polypropylene resin, so it differs from the melting point measured for the random polypropylene resin alone. The melting point _T1 of the component (A) in the liquid-repellent layer and the melting point _T2 of the resin in the second resin layer were measured with a thermal analyzer (TA7000, manufactured by Hitachi High-Tech Science Co., Ltd.).

<Evaluation of liquid repellency>
(Residual liquid evaluation after retort treatment)
The liquid repellent laminates obtained in Examples and Comparative Examples were evaluated for liquid repellency after retort treatment by the method shown in FIG. First, two samples 100 were prepared by cutting the liquid-repellent laminate 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. The pouch was heat-sealed over a width of 10 mm under conditions to form a sealed portion 51, and a pouch having one longitudinal end open was produced (see FIG. 3(a)). Next, 180 g of the oil-in-water dispersion type liquid 54 (trade name “Boncurry Gold Medium Spicy”, lipid content 7.0 g / 180 g, manufactured by Otsuka Foods Co., Ltd.) was injected from the opening of the pouch (Fig. 3 (b )). After that, the opening was heat-sealed over a width of 10 mm with a heat sealer under the conditions of 190° C., 0.03 MPa, and 2 sec to form a sealed portion 51, thereby sealing the pouch (see FIG. 3(c)).

After the sealed pouch is put into a high-temperature and high-pressure cooking sterilizer (manufactured by Hitachi Capital Co., Ltd.), retort treatment is performed at 121 ° C. for 30 minutes with high-temperature steam at a pressure of 0.2 MPa, and the sealed pouch is heated at 100 ° C. It was boiled in hot water for 5 minutes. Immediately after the above treatment, the top of the sealed pouch was cut to form a spout (see Figure 3(d)). Next, the pouch was turned upside down, and the spout was held at an angle of 45° from the horizontal surface for 10 seconds, the oil-in-water dispersion liquid 54 was discharged into the container 56, and the discharge amount was weighed by the scale 57 (( e)). From the weighed discharge amount, the residual liquid amount (%) was determined by the following formula.
Residual liquid amount (%) = {(180-discharged amount) / 180} x 100
The measurement was performed three times, and the residual liquid was evaluated from the average residual liquid amount of the three times according to the following evaluation criteria. Table 1 shows the residual liquid amount and the residual liquid evaluation results.
◎: Average residual liquid amount is less than 6.5% ○: Average residual liquid amount is 6.5% or more and less than 8.0% △: Average residual liquid amount is 8.0% or more and less than 10.0% ×: Average residual liquid amount Liquid volume is 10.0% or more

(Appearance evaluation after retort treatment)
In the evaluation of the remaining liquid, the discharge behavior of the liquid when discharged from the pouch was visually observed, and the external appearance was evaluated according to the following evaluation criteria. Table 1 shows the results.
⊚: A state of repelling the liquid cleanly and/or a state of clean sliding of the liquid is observed, and there is almost no adhesion to the film.
◯: A state of repelling the liquid and/or a state of the liquid sliding down is observed, and there is little adhesion to the film.
Δ: Appearance of repelling liquid and/or appearance of liquid sliding down is observed, but adheres to the film.
x: Neither repelling the liquid nor sliding down the liquid was observed, and a large amount of the liquid adhered to the film.

As is clear from the results shown in Table 1, according to the liquid-repellent laminates of Examples 1 to 30, compared with the liquid-repellent laminates of Comparative Examples 1-4, the residual liquid was less, and Since it was confirmed that the liquid slid down inside the pouch, it was confirmed that the liquid repellency could be improved.

Since the liquid-repellent laminates of Examples 11 to 30 are provided with the second resin layer, they are excellent in heat resistance and impact resistance.

DESCRIPTION OF SYMBOLS 1, 2... Liquid-repellent laminated body 10... Liquid-repellent film 11... Liquid-repellent layer 12... Second resin layer 13... Adhesive 14... Base material 51... Seal part 54... Oil in water Dispersion type liquid 56 Container 57 Scale 100 Sample for evaluation of liquid-repellent laminate.

Claims (6)

A liquid-repellent laminate comprising a substrate and a liquid-repellent film provided on the substrate and having a liquid-repellent layer formed using a resin composition ,
The liquid-repellent layer is arranged on at least one outermost surface of the liquid-repellent laminate ,
The resin composition contains (A) a polyolefin resin and (B) a silicone-acrylic copolymer,
The content of the silicone-acrylic copolymer (B) in the resin composition is 0.5 to 20% by mass based on the total solid content of the resin composition ,
(B) the silicone-acrylic copolymer has an average particle size of 10 to 500 μm,
A liquid-repellent laminate, wherein the liquid-repellent layer has an arithmetic mean roughness Ra of 0.1 μm or more . The liquid-repellent laminate according to claim 1 , wherein the liquid-repellent layer has a coefficient of static friction of 0.40 or less. 3. The liquid-repellent laminate according to claim 1, wherein the liquid -repellent film further comprises one or more resin layers provided on the main surface of the liquid-repellent layer on the substrate side . The melting point T ₁ (°C) of the (A) polyolefin resin 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 satisfies the relationship of T ₁ < T ₂ . A packaging material formed using the liquid-repellent laminate according to any one of claims 1 to 4 . The packaging material according to claim 5 , which is used for applications where heat treatment at 80°C or higher is applied.

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