JP7452250B2 - Liquid repellent structure, manufacturing method thereof, and packaging material - Google Patents

Description

The present disclosure relates to a liquid-repellent structure, a method for manufacturing the same, and a packaging material having the liquid-repellent structure on the side that contacts an article.

Various embodiments of water-repellent structures are known. For example, Patent Document 1 discloses a water-repellent structure in which a fine particle layer in which scale-like inorganic fine particles are fixed with a binder resin and a water-repellent film layer covering the surface of the fine particle layer are provided on the surface of a base material part. is disclosed. Patent Document 2 discloses a single-layer water-repellent heat-sealing film containing a thermoplastic resin and hydrophobic particles. Patent Document 3 describes a water-repellent laminate for a lid material comprising a base material and a thermally adhesive layer on the base material, in which the thermally adhesive layer contains a thermoplastic resin, water-repellent fine particles, and an average particle size smaller than the water-repellent fine particles. It is disclosed that it includes bead particles with large diameters.

JP 2017-132055 Publication JP 2017-155183 Publication International Publication No. 2017/204258

In the inventions described in Patent Documents 1 to 3, water repellency is evaluated based on the contact angle with water droplets. In the inventions described in Patent Documents 2 and 3, yogurt repellency (yogurt adhesion) is also evaluated. However, in the inventions described in these documents, liquid repellency to oil-containing liquids (eg, curry, fresh cream) is not studied.

An object of the present disclosure is to provide a liquid repellent structure that has excellent liquid repellency against water and also has excellent liquid repellency against oil or liquid substances containing the same, and a method for manufacturing the same. do. Another object of the present disclosure is to provide a packaging material having the above liquid-repellent structure on the side that comes into contact with an article.

That is, the invention according to claim 1 is a liquid repellent structure comprising a surface to be imparted with liquid repellency and a liquid repellent layer formed on the surface,
Liquid repellency characterized in that the liquid repellent layer contains a binder resin containing a fluorine-containing resin, and the core space volume on the surface of the liquid repellent layer is in the range of 4 to 10 μm ³ /μm ² It is a structure.

Next, the invention according to claim 2 is the liquid-repellent structure according to claim 1, characterized in that the skewness value of the surface of the liquid-repellent layer is in the range of 0.0 to 0.3. .

Next, the invention according to claim 3 is the liquid-repellent structure according to claim 1 or 2, wherein the liquid-repellent layer contains a filler dispersed in the binder resin. .

Next, the invention according to claim 4 is characterized in that the liquid repellent layer contains two or more types of fillers having different average primary particle diameters as the filler. It is a structure.

Next, the invention according to claim 5 is the liquid-repellent structure according to claim 3 or 4, characterized in that at least one type of filler among the fillers is a filler having an average primary particle diameter of 8 to 30 μm. It is the body.

Next, the invention according to claim 6 is the liquid repellent according to any one of claims 3 to 5, characterized in that the total weight of the filler is in a range of 3.0 to 10.6 g/m ² . It is a sexual structure.

Next, the invention according to claim 7 is the liquid-repellent structure according to any one of claims 1 to 6, characterized in that the liquid-repellent layer further contains a thermoplastic resin.

Next, the invention according to claim 8 includes a base layer disposed between the surface to be imparted with liquid repellency and the liquid repellent layer. The liquid repellent structure described in .

Next, the invention according to claim 9 is the liquid-repellent structure according to claim 8, wherein the base layer contains a filler having an average primary particle size of 8 to 30 μm.

Next, the invention according to claim 10 is a packaging material characterized by having the liquid-repellent structure according to any one of claims 1 to 9 on the side that comes into contact with an article.

Next, the invention according to claim 11 provides a step of preparing a coating liquid containing a binder resin containing a fluorine-containing resin;
forming a coating film of the coating liquid on the surface to which liquid repellency is to be imparted;
forming a liquid-repellent layer by drying and curing the coating film,
The method for producing a liquid-repellent structure is characterized in that the volume of the core space on the surface of the liquid-repellent layer is in the range of 4 to 10 μm ³ /μm ² .

Next, the invention according to claim 12 is the production of the liquid-repellent structure according to claim 11, characterized in that the skewness value of the surface of the liquid-repellent layer is in the range of 0.0 to 0.3. It's a method.

The liquid-repellent structure of the present invention includes a liquid-repellent layer on its surface, and has irregularities on the surface of the liquid-repellent layer. Even when it comes into contact with a liquid material containing oil, the convex portions of the surface irregularities support the liquid material, so the contact area is reduced and physical liquid repellency is exhibited. In addition, since this liquid-repellent layer contains a fluorine-containing resin, it exhibits chemically liquid-repellent properties based on the inherent properties of this fluorine-containing resin. In this way, the liquid-repellent structure of the present invention exhibits liquid repellency physically and chemically, so it has excellent repellency not only against liquids containing water, but also against oil and liquids containing oil. It shows liquid properties.

Note that the void volume of the core section (Vvc) on the surface of the liquid-repellent layer can be measured according to ISO025178. This core space volume Vvc is defined as the space sandwiched between the reference plane and a plane parallel to the reference plane that includes the position of the maximum height of the convex portion, with the average surface of the surface irregularities as the reference plane. It shows the volume occupied by voids.

The fact that the core space volume Vvc is small means that the maximum height of the convex portion is low, or that the volume occupied by the material constituting the liquid repellent layer, such as filler, in the space is large. , the contact area with the liquid material, etc. becomes large, and sufficient liquid repellency cannot be exhibited against oil or the liquid material containing oil. As can be seen by comparing Examples 1-1 to 1-20 and Comparative Example 1-1, which will be described later, the lower limit of the core space volume Vvc that exhibits sufficient liquid repellency is 4 μm ³ /μm ² .

Conversely, a large core space volume Vvc means that the volume occupied by voids is large. For this reason, the liquid material and the like penetrate deeply into the concave portions of the surface irregularities, increasing the contact area between the two, making it impossible to exhibit sufficient liquid repellency. As can be seen by comparing Examples 1-1 to 1-20 and Comparative Example 1-2, which will be described later, the upper limit of the core space volume Vvc that exhibits sufficient liquid repellency is 10 μm ³ /μm ² .

In this way, even when the core space volume Vvc is in the range of 4 to 10 μm ³ /μm ² , if the skewness value is in the range of 0.0 to 0.3, particularly excellent liquid repellency can be achieved. Demonstrate.

The skewness value means the root mean cube of the height Z(x) at a standard length made dimensionless by the cube of the root mean square height Rq of the surface, and the peak part and It represents the degree of deviation from the valley. That is, when the skewness value is 0, the peaks and valleys are equal. When the skewness value is a negative value, it is biased upward with respect to the average line, the contact area with the contents becomes large, and the liquid repellency is poor. On the other hand, when the skewness value is positive, it is biased downward from the average line and exhibits excellent liquid repellency, but when it exceeds 0.3, the contents tend to get into the recesses. As a result, the liquid repellency decreases.

Note that the core space volume Vvc and skewness value can be measured according to JIS B0681-2.

It is clear from Examples 2-1 to 2-72 described below that particularly excellent liquid repellency is exhibited when the skewness value is in the range of 0.0 to 0.3. That is, even when the core space volume Vvc is in the range of 4 to 10 μm ³ /μm ² and the skewness value is smaller than 0.0 (Examples 2-1, 2-3, 2-7, 2-12, 2-18, 2-20, 2-2, 2-28, 2-32, 2-35, 2-37, 2-41, 2-44, 2-51, 2-52, 2-55, 2- 64, 2-68, 2-71, 2-72), the peelability against oil-containing mayonnaise is B to D, and the skewness value is greater than 0.3 (Examples 2-5, 2-9). , 2-11, 2-24, 2-26, 2-29, 2-39, 2-45, 2-48, 2-58, 2-59, 2-60, 2-61, 2-62, 2 -63, 2-65, 2-66, 2-67) have release properties for mayonnaise containing oil ranging from B to C, while skewness values range from 0.0 to 0.3. Case (Example 2-2, 2-4, 2-6, 2-8, 2-10, 2-13, 2-14, 2-15, 2-16, 2-17, 2-19, 2- 21, 2-23, 2-25, 2-27, 2-30, 2-31, 2-33, 2-34, 2-36, 2-40, 2-42, 2-43, 2-46, 2-47, 2-49, 2-50, 2-53, 2-54, 2-56, 2-57, 2-69, 2-70) have release properties from A to B for mayonnaise containing oil. It is.

FIGS. 1(a) to 1(c) are cross-sectional views each schematically showing an embodiment of a liquid-repellent structure according to the present invention. FIG. 2 is a cross-sectional view schematically showing another embodiment of the liquid-repellent structure according to the present invention. FIG. 3 is a cross-sectional view schematically showing another embodiment of the liquid-repellent structure according to the present invention. FIG. 4 is a cross-sectional view schematically showing another embodiment of the liquid-repellent structure according to the present invention. FIG. 5 is a cross-sectional view schematically showing another embodiment of the liquid-repellent structure according to the present invention.

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the following description, the same elements or elements having the same function will be denoted by the same reference numerals, and redundant description will be omitted.

<Liquid repellent structure>
FIG. 1(a) is a schematic cross-sectional view of a specific example of the liquid-repellent structure according to the present embodiment. As shown in FIG. 1, this liquid-repellent structure A includes a base material 1 having a surface to be treated (a surface to be imparted with liquid repellency), and a liquid-repellent layer 3 formed on the surface to be treated. Equipped with

(Base material)
The base material 1 is not particularly limited as long as it has a surface that is to be imparted with liquid repellency and serves as a support. (Thickness: approximately 1 to 10 mm). Examples of the film-like base material include paper, resin film, metal foil, and the like. By using the inner surface of a film packaging material made of these materials as the treated surface 1a and forming the liquid-repellent layer 3 thereon, it is possible to obtain a packaging bag to which the contents do not easily adhere. Examples of the plate-shaped base material include paper, resin, metal, and glass.

By using the inner surface of a container formed from these materials as the surface to be treated and forming the liquid-repellent layer 3 thereon, it is possible to obtain a container to which the contents do not easily adhere.

Examples of the paper include high quality paper, special high quality paper, coated paper, art paper, cast coated paper, imitation paper, and kraft paper. Examples of the resin include polyolefin, acid-modified polyolefin, polyester (for example, polyethylene terephthalate (PET)), polyethylene (PE), polypropylene (PP), polyamide (PA), polyvinyl chloride (PVC), cellulose acetate, cellophane resin, etc. It will be done. Examples of the metal include aluminum and nickel.

When the base material 1 is in the form of a film, it is preferable that the base material 1 has heat fusion properties with the liquid repellent layer 3. Further, when a base layer is interposed between the base material 1 and the liquid-repellent layer 3 as described later, it is preferable that the base material 1 has thermal fusion properties with the base layer. The melting point of the base material 1 is preferably 170°C or lower. Thereby, when a packaging bag is formed by heat sealing, the adhesion between the base material 1 and the liquid-repellent layer 3 becomes stronger, so that the heat sealability is further improved. From such a viewpoint, it is more preferable that the melting point of the base material 1 is 150°C or lower. The melting point of the base material 1 can be measured by differential scanning calorimetry.

(liquid repellent layer)
The liquid-repellent layer 3 is a layer having liquid-repellent properties, and is formed to cover part or all of the surface of the base material 1. Liquid repellency is a concept that includes both water repellency and oil repellency, and specifically, it is a property of repelling liquid, semi-solid, or gel-like aqueous or oil-based materials. Examples of water-based or oil-based materials include water, oil, yogurt, curry, fresh cream, jelly, pudding, syrup, food such as porridge and soup, detergents such as hand soap and shampoo, pharmaceuticals, cosmetics, and chemicals. . In the liquid-repellent structure 10, the liquid-repellent layer 3 forms the innermost layer or the outermost layer so that these are in direct contact with each other.

This liquid-repellent layer 3 includes a binder resin 31 as an essential component. In addition, in order to form irregularities on the surface of the liquid-repellent layer 3 so that the core space volume is in the range of 4 to 10 μm ³ /μm ² , and in addition to this, the skewness value is set to 0.0 to 0.3. Filler 32 can be dispersed in this binder resin 31. The weight of filler 32 can range from 3.0 to 10.6 g/m ² . If the weight of the filler 32 is less than 3.0 g/m ² , the filler 32 may be buried in the binder resin 31 and the surface of the liquid-repellent layer 3 may have poor unevenness, so that sufficient liquid repellency may not be exhibited. Furthermore, if it exceeds 10.6 g/m ² , the filler 32 is likely to fall off from the liquid-repellent layer 3 . On the other hand, when the weight of the filler 32 is in the range of 3.0 to 10.6 g/m ² , appropriate irregularities are formed on the surface of the liquid-repellent layer 3 and the filler does not fall off. In addition to this, other additives may be included as necessary within a range that does not impair the liquid repellent function.

Note that the liquid-repellent layer 3 may not contain a structural unit derived from pyrrolidones, from the viewpoint of further improving the liquid repellency against a highly viscous liquid containing a surfactant or the like. That is, the structural unit derived from pyrrolidones not only does not need to be included in the fluorine-containing resin, but also does not need to be included in any of the other components constituting the liquid-repellent layer 3. The presence or absence of structural units derived from pyrrolidones in the liquid-repellent layer 3 can be determined by infrared spectroscopy, nuclear magnetic resonance spectroscopy, pyrolysis GC-MS, or the like.

Next, the binder resin 31 contains at least a fluorine-containing resin. Binder resin 31 may further include one or both of a thermoplastic resin and a crosslinking agent. When the binder resin 31 contains a crosslinking agent, the binder resin 31 in the liquid-repellent layer 3 may have a crosslinked structure in which a fluorine-containing resin or a thermoplastic resin is crosslinked via the crosslinking agent.

The fluorine-containing resin is not particularly limited, and resins having structures such as perfluoroalkyl, perfluoroalkenyl, and perfluoropolyether can be used as appropriate. The fluorine-containing resin preferably contains a fluorine-acrylic copolymer from the viewpoint of further improving the liquid repellency of the liquid repellent layer 3. The fluorine-acrylic copolymer is a copolymer consisting of a fluorine-containing monomer and an acrylic monomer. The fluorine-acrylic copolymer may be a block copolymer or a random copolymer. By using the fluorine-acrylic copolymer, the weather resistance, water resistance, chemical resistance, and film-forming properties of the liquid-repellent layer 3 can also be improved.

The fluorine content in the fluorine-containing resin is, for example, 30 to 60% by mass, and may be 40 to 50% by mass. The fluorine content means the ratio of the mass of fluorine atoms to the total mass of atoms constituting the fluorine-containing resin.

As the fluorine-containing resin, commercially available fluorine-based paints can be used. Examples of commercially available fluorine-based paints include Asahi Guard manufactured by Asahi Glass Co., Ltd., SF Coat manufactured by AGC Seimi Chemical Co., Ltd., Futergent manufactured by Neos Co., Ltd., Fluorolink manufactured by Solvay, Unidyne manufactured by Daikin Industries, Ltd. Examples include the H-3539 series manufactured by Daiichi Kogyo Seiyaku Co., Ltd. and the Modiper F series manufactured by NOF Corporation.

Fluorine-containing resins include pyrrolidone or its derivatives (pyrrolidones) from the viewpoint of further improving the liquid repellency for highly viscous liquids (e.g., hand soap, body soap, shampoo, and conditioner) that contain surfactants and the like. It may not contain the derived structural unit. Here, examples of the pyrrolidones include N-vinyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-5-methyl-2-pyrrolidone, and N-vinyl-3,3-pyrrolidone. Examples include dimethyl-2-pyrrolidone. Examples of fluorine-containing resins that do not contain structural units derived from pyrrolidones include Asahi Guard AG-E060, AG-E070, and AG-E090 manufactured by Asahi Glass Co., Ltd., and Unidyne TG-8111 manufactured by Daikin Industries, Ltd. .

Thermoplastic resins are not particularly limited, and include, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, homo, block, or random polypropylene, propylene-α-olefin copolymer, and ethylene. -Vinyl acetate copolymers and the like. For example, an ethylene-α-olefin copolymer can be referred to as a block copolymer, a random copolymer, etc. of propylene and α-olefin. Examples of the α-olefin component include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1-pentene.

The melting point of the thermoplastic resin is, for example, 50 to 135°C. Since the melting point is 135° C. or lower, the fluorine-containing resin can easily bleed out onto the surface of the liquid-repellent layer 3. When the fluorine-containing resin bleeds out to the surface, the surface free energy can be lowered, and thereby the surface of the liquid repellent layer 3 can exhibit excellent liquid repellency. Note that there is a method of drying at a high temperature to promote bleed-out of the fluorine-containing resin, but if the melting point of the thermoplastic resin is too high, a corresponding high temperature is required, which may cause problems such as deformation of the base material 1. There is. On the other hand, when the melting point is 50° C. or higher, a certain degree of crystallinity is ensured, thereby suppressing the occurrence of blocking due to softening. From this point of view, it is more preferable that the melting point of the thermoplastic resin is 60 to 120°C.

The thermoplastic resin may be a modified polyolefin modified with a predetermined acid. The modified polyolefin is obtained by graft-modifying a polyolefin 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. Moreover, modified polyolefins such as hydroxyl modified polyolefins and acrylic modified polyolefins can also be used as the polyolefins. Examples of modified polyolefin resins include Aurelen manufactured by Nippon Paper Industries Co., Ltd., Zaixen manufactured by Sumitomo Seika Chemical Co., Ltd., Sevolsion manufactured by Sumitomo Seika Chemical Co., Ltd., Unistol manufactured by Mitsui Chemicals Co., Ltd., and Arrowbase manufactured by Unitika Co., Ltd. etc.

Since the modified polyolefin has a functional group introduced therein, it is preferable from the viewpoint that it easily reacts with a crosslinking agent to form a crosslinked structure. Examples of the functional groups include carboxyl groups, hydroxyl groups, (meth)acryloyl groups, and amino groups. By using a modified polyolefin having these functional groups together with a crosslinking agent to be described later, a crosslinked structure consisting of a thermoplastic resin, a fluorine-containing resin, and a crosslinking agent is formed in the liquid repellent layer 3, resulting in superior durability and liquid repellency. Layer 3 can be applied.

The crosslinking agent preferably has a functional group that reacts with the fluorine-containing resin. As such a crosslinking agent, for example, a crosslinking agent having a functional group such as an aziridine group, an isocyanate group, a carbodiimide group, or an amino group can be used. Commercially available crosslinking agents include, for example, Chemitite manufactured by Nippon Shokubai Co., Ltd., Takenate manufactured by Mitsui Chemicals, Carbodilite manufactured by Nisshinbo Chemical Co., Ltd., Meikanate manufactured by Meisei Chemical Co., Ltd., Cymel manufactured by Cytec Industries, Ltd. ).

Note that the fluorine-containing resin is generally used as an aqueous dispersion in water. Therefore, many fluorine-containing resins have hydrophilic groups such as hydroxyl groups and amino groups in order to increase their affinity with water. By using a crosslinking agent having a functional group that reacts with the fluorine-containing resin, these functional groups possessed by the fluorine-containing resin react with the functional groups possessed by the crosslinking agent, and a crosslinked structure is formed in the liquid-repellent layer 3. becomes. Moreover, since these functional groups that the fluorine-containing resin has are reduced by reacting with the crosslinking agent, the number of functional groups remaining in the liquid-repellent layer 3 is reduced. Therefore, even when the liquid repellent layer 3 is in contact with a liquid material for a long period of time, a decrease in liquid repellency can be suppressed, and excellent liquid repellency can be maintained for a long period of time. Note that when using a fluorine-containing resin as a dispersion in a solvent other than water, the fluorine-containing resin has a structure (for example, a hydrocarbon chain, etc.) to increase its affinity with the solvent used. Good too.

The content of the thermoplastic resin in the binder resin 31 (based on the mass of the binder resin 5b) is, for example, 5 to 90% by mass, and may be 10 to 50% by mass or 20 to 30% by mass. When the content of the thermoplastic resin in the binder resin 5b is 5% by mass or more, it is possible to sufficiently suppress the filler from falling off from the liquid-repellent layer, and on the other hand, when the content is 90% by mass or less, the fluorine-containing resin The content of crosslinking agent and crosslinking agent can be ensured sufficiently, and the liquid repellent layer can easily exhibit excellent liquid repellency and durability.

The ratio W _C /W _J of the mass W C of the crosslinking agent contained in the binder resin 31 and the mass W _J of the _fluorine -containing resin contained in the binder resin 31 is, for example, 0.01 to 0.5, and 0. It may be between .05 and 0.3 or between 0.1 and 0.2. When the ratio W _C /W _J is 0.01 or more, it is possible to sufficiently suppress the filler from falling off from the liquid-repellent layer, and to sufficiently increase the durability of the liquid-repellent layer. On the other hand, when the ratio W _C /W _J is 0.5 or less, the content of the fluorine-containing resin can be ensured sufficiently, and the fluorine-containing resin can be sufficiently bleed out to the surface of the liquid-repellent layer 3. , it is possible to exhibit good liquid repellency.

When the binder resin 31 contains a thermoplastic resin and a crosslinking agent, the mass W _C of the crosslinking agent contained in the binder resin 31, the mass W _P of the thermoplastic resin contained in the binder resin 31, and the mass W _J of the fluorine-containing resin are The ratio W _C /(W _P +W _J ) to the total (W _P +W _J ) is, for example, 0.01 to 0.5, 0.05 to 0.3, or 0.07 to 0.2. It's okay. When the ratio W _C /(W _P +W _J ) is 0.01 or more, it is possible to sufficiently suppress the filler from falling off from the liquid-repellent layer, and to sufficiently increase the durability of the liquid-repellent layer 3. be able to. On the other hand, when the ratio W _C /(W _P +W _J ) is 0.5 or less, the content of the fluorine-containing resin and the thermoplastic resin can be sufficiently ensured, and the fluorine-containing resin can be sufficiently coated on the surface of the liquid-repellent layer 3. Since the filler can be caused to bleed out, good liquid repellency can be developed, and the effect of suppressing the filler from falling off from the liquid repellent layer 3 made of thermoplastic resin can be sufficiently obtained.

Next, as the filler 32, a first filler 32a having an average primary particle diameter of 5 to 1000 nm and a second filler 32b having an average primary particle diameter of 0.1 to 6 μm can be used. The first filler 32a and the second filler 32b can be individually blended into the liquid repellent layer 3. Furthermore, two or more types of fillers having different average primary particle diameters can also be blended as the filler 32. By blending two or more types of fillers with different average primary particle diameters, the density of the points that come into contact with and support contents such as oil or liquids containing oil increases, further improving its liquid repellency. can be increased. For example, it is also possible to mix both the first filler 32a with an average primary particle size of 5 to 1000 nm and the second filler 32b with an average primary particle size of 0.1 to 6 μm and incorporate it into the liquid-repellent layer 3. be. A scale-shaped filler can also be used as the first filler 32a and the second filler 32b.

In the liquid-repellent structure A shown in FIG. 1(a), a first filler 32a having an average primary particle diameter of 5 to 1000 nm is solely incorporated into the liquid-repellent layer 3 as the filler 32. Further, the liquid-repellent structure B shown in FIG. 1(b) is an example in which a second filler 32b in the form of scales having an average primary particle diameter of 0.1 to 6 μm is solely blended as the filler 32. Further, in the liquid-repellent structure C shown in FIG. 1(c), both the first filler 32a and the second filler 32b are blended into the liquid-repellent layer 3.

Further, in addition to these fillers 32a and 32b, it is also possible to blend a third filler 32c having a large particle size with an average primary particle size of 8 to 30 μm. FIG. 2 shows a liquid-repellent structure D in which the liquid-repellent layer 3 includes the third filler 32c in addition to the fillers 32a and 32b. By blending the third filler 32c with a large particle size in this way, these fillers 32a, 32b, 32c are prevented from being buried in the binder resin 31, and the density of the convex portions of the surface unevenness increases, so that the oil Alternatively, it can contact and support contents such as liquid materials containing the same, thereby further enhancing its liquid repellency. Therefore, even if the thickness of the liquid-repellent layer 3 is reduced, the core space volume Vvc can be increased. In addition to this, the skewness value Ssk can be increased.

Note that the average primary particle diameter of these fillers 32a, 32b, and 32c is determined by measuring the lengths of the major and minor axes of any ten fillers 32a, 32b, and 32c within the field of view of the SEM, and calculating the sum by 2. Means the average value of the values obtained by dividing.

Examples of materials constituting the first filler 32a include silica, titanium oxide, aluminum oxide, mica, talc, calcium carbonate, barium sulfate, zinc oxide, smectite, and zeolite. For example, the following commercial products can be used as the first filler 32a. Commercially available silica fillers include, for example, AEROSIL manufactured by Nippon Aerosil, Seahoster manufactured by Nippon Shokubai Co., Ltd., and silica spherical fine particles QSG and QCB manufactured by Shin-Etsu Silicone. A commercially available titanium oxide filler includes, for example, AEROXIDE TiO ₂ manufactured by Evonik Degussa. A commercially available aluminum oxide filler includes, for example, AEROXIDE Alu manufactured by Evonik Degussa.

In addition, materials constituting the second filler 32b having an average primary particle diameter of 0.1 to 6 μm include silica, mica, aluminum oxide, talc, titanium oxide, calcium carbonate, barium sulfate, zinc oxide, smectite, zeolite, etc. Can be mentioned. Commercially available products include, for example, Sun Lovely manufactured by AGC SI Tech Co., Ltd., Repco Mica manufactured by Repco Co., Ltd., Cerasur manufactured by Kawai Lime Industry Co., Ltd., Sunsphere manufactured by AGC SI Tech Co., Ltd., and Sumitomo Seika Co., Ltd. Flow Beads manufactured by Soken Kagaku Co., Ltd., Chemisnow manufactured by Negami Kogyo Co., Ltd., Art Pearl manufactured by Nippon Shokubai Co., Ltd., and Seahoster manufactured by Nippon Shokubai Co., Ltd. are listed. Among these, Sun Lovely manufactured by AGC SI Tech Co., Ltd. is a scaly silica. Further, Repco Mica manufactured by Repco Co., Ltd. is a scaly mica, and Cerasur manufactured by Kawai Lime Industry Co., Ltd. is a scaly aluminum oxide. Note that the second filler 32b may be one that has not been subjected to hydrophobic treatment or liquid repellency treatment, or may be one that has been subjected to hydrophobic treatment or liquid repellency treatment.

The average primary particle diameter of the second filler 32b is preferably 0.1 to 6 μm, and may be 0.1 to 4 μm or 4 to 6 μm. When the average primary particle diameter of the second filler 32b is 0.1 μm or more, aggregates 5 are likely to be formed, and on the other hand, when it is 6 μm or less, aggregates 5 are easily formed due to the complex and fine shape of the second filler 32b. Liquid repellency is sufficiently developed.

The first filler 32a and the second filler 32b may form an aggregate inside the liquid-repellent layer 3. These fillers 32a, 32b and their aggregates form irregularities on the surface of the liquid-repellent layer 3. The aggregate is composed of these fillers 32a and 32b and a binder resin covering them.

Next, the third filler 32c having a particle size is, for example, spherical and has an average primary particle size of 8 to 30 μm. On the surface of the liquid-repellent layer 3 including the third filler 32c of this size, roughness is formed that is rougher than the roughness caused by the first filler 32a, the second filler 32b, or aggregates thereof. As a result, the liquid-repellent layer 3 has particularly excellent liquid-repellent properties even for liquids containing surfactants and the like and having high viscosity (for example, hand soap, body soap, shampoo, and conditioner). The third filler 32c may have liquid repellency.

Examples of materials constituting the third filler 32c include silica, silicone, acrylic resin, urethane resin, talc, mica, titanium oxide, calcium carbonate, barium sulfate, zinc oxide, smectite, zeolite, aluminum oxide, and the like. For example, the following commercial products can be used as the third filler 32c. Commercially available products include, for example, Sunsphere manufactured by AGC SI Tech Co., Ltd., Silicone Powder KMP manufactured by Shin-Etsu Silicone Co., Ltd., Gantz Pearl manufactured by Aica Kogyo Co., Ltd., Art Pearl manufactured by Negami Kogyo Co., Ltd., and Nippon Steel Chemical & Material. Examples include HS-208, 304, 312, 315 manufactured by Sumitomo Seika Chemical Co., Ltd., Flow Beads manufactured by Sumitomo Seika Chemical Co., Ltd., Chemisnow manufactured by Soken Chemical Co., Ltd., and QSG-30, 80 manufactured by Shin-Etsu Chemical Co., Ltd. Among these, Sunsphere manufactured by AGC SI Tech Co., Ltd. is a silica filler. Silicone powder KMP manufactured by Shin-Etsu Silicone is a silicone filler. Furthermore, Gantz Pearl manufactured by Aica Kogyo Co., Ltd. is an acrylic resin filler, and Art Pearl manufactured by Negami Kogyo Co., Ltd. is crosslinked acrylic beads or crosslinked urethane beads.

<Method for manufacturing liquid repellent structure>
A method for manufacturing the liquid-repellent structure 10 will be described. The manufacturing method according to the present embodiment includes the steps of preparing a coating liquid for forming a liquid-repellent layer, forming a coating film of the coating liquid on the treated surface 1a of the substrate 1, and drying and curing the coating film. and forming a liquid repellent layer 3 by doing so. Each step will be explained below.

First, a coating liquid containing the filler 32, a fluorine-containing resin, a solvent, a thermoplastic resin as necessary, a crosslinking agent as necessary, and additives as necessary is prepared. Examples of the solvent include water, alcohol, and organic solvents. The blending amount (solid content) of each component in the coating liquid may be adjusted as appropriate so that the core space volume Vvc in the liquid-repellent layer 3 is as described above. Note that the thermoplastic resin may be in the form of an emulsion dispersed in water, alcohol, or the like. Such a polyolefin emulsion may be prepared by emulsifying a polymer produced by a polymerization reaction of corresponding monomers, or may be prepared by emulsion polymerization of corresponding monomers.

The obtained coating liquid is applied onto the base material 1. As the coating method, any known method can be used without particular limitation, and examples thereof include a dipping method; a method using a spray, a coater, a printing machine, a brush, and the like. In addition, the types of coaters and printing machines used in these methods and their coating methods include gravure coaters such as direct gravure method, reverse gravure method, kiss reverse gravure method, and offset gravure method, reverse roll coater, and microgravure. Examples include a coater, a chamber doctor coater, an air knife coater, a dip coater, a bar coater, a comma coater, and a die coater.

The coating film formed on the base material 1 is dried and cured by heating. Thereby, a liquid-repellent structure 10 including the base material 1 and the liquid-repellent layer 3 provided on the base material 1 can be obtained. When the coating liquid contains a crosslinking agent, a crosslinked structure made of a fluorine-containing resin, a thermoplastic resin used as necessary, and a crosslinking agent is formed in the liquid repellent layer 3. The heating conditions are not limited as long as they can volatilize the solvent and cause a crosslinking reaction, but may be, for example, 60 to 100° C. for 0.5 to 5 minutes.

<Packaging material>
The packaging material according to this embodiment has a liquid-repellent structure 10 on the side that comes into contact with the article. The packaging material according to this embodiment can be applied to products containing water (e.g., water, drinks, yogurt) and products containing oil (e.g., curry and fresh cream), as well as hand soap, body soap, shampoo. It can also be applied to an article selected from the group consisting of Specific examples of packaging materials include retort pouches for curry and pasta sauce, containers and lids for yogurt and pudding, containers and refill pouches for toiletries such as hand soap, shampoo and conditioner, toothpaste and pharmaceuticals. Examples include tubes for use.

In the above embodiment, the case where the liquid-repellent layer is formed in direct contact with the surface to be treated of the base material 1 is illustrated, but the base layer is formed on the surface to be treated of the base material 1, and the A liquid repellent layer may be formed on the base layer. The base layer will be explained below.

(base layer)
The base layer 2 is a layer disposed between the base material 1 and the liquid-repellent layer 3, and is formed to cover part or all of the surface to be treated of the base material 1. By interposing the base layer between the base material 1 and the liquid-repellent layer 3, the adhesion between the base material 1 and the liquid-repellent layer 3 can be improved. Further, by providing the base layer 2, the liquid repellency of the liquid repellent structure can be further improved. 3 to 5 show a liquid-repellent structure E in which the base layer 2 is disposed between the base material 1 and the liquid-repellent layer 3 in this manner.

The base layer 2 contains at least a thermoplastic resin. As the thermoplastic resin, the same thermoplastic resin as that used for the liquid-repellent layer 3 can be used.

Further, as shown in FIG. 3, the base layer 2 may include a fourth filler 21 having an average primary particle diameter of 5 to 30 μm. Further, as the fourth filler, the same filler as the third filler 32c used in the liquid-repellent layer 3 can be used. In the liquid-repellent structure E shown in FIG. 3, the liquid-repellent layer 3 includes a first filler 32a and a second filler 32b, but does not include a third filler 32c. When the base layer 2 contains the fourth filler 21 having a large particle size as described above, the surface of the base layer 2 is uneven based on the fourth filler 21, and the liquid repellent layer 3 is formed under the fourth filler 21. Since it is provided along the unevenness of the surface of the stratum 2, even if the liquid-repellent layer 3 does not include the third filler 32c with a large particle size, it is possible to increase the core space volume Vvc, and also to reduce skewness. The value Ssk can be increased.

Note that the liquid-repellent layer 3 does not need to include either the first filler 32a or the second filler 32b. Even in this case, since the base layer 2 contains the fourth filler 21, irregularities based on the fourth filler 21 are formed on the surface of the liquid-repellent layer 3. FIG. 4 shows an example of a liquid-repellent structure F in which the base layer 2 is made of only a thermoplastic resin containing no filler. However, even in this case, the core space volume Vvc on the surface of the liquid-repellent layer 3 needs to be in the range of 4 to 10 μm ³ /μm ² . Preferably, the skewness value is in the range of 0.0 to 0.3.

Further, the base layer 2 can also be composed only of a thermoplastic resin containing no filler. FIG. 5 shows an example of a liquid-repellent structure G in which the base layer 2 is made of only a thermoplastic resin containing no filler. Of course, even in this case, the core space volume Vvc on the surface of the liquid-repellent layer 3 needs to be in the range of 4 to 10 μm ³ /μm ² , and it is desirable that the cueness value is in the range of 0.0 to 0.3. . For this reason, it is desirable that the liquid-repellent layer 3 contains at least one type of filler among the first filler 32a, the second filler 32b, and the third filler 32c. In the liquid-repellent structure G shown in FIG. 5, the liquid-repellent layer 3 contains a first filler 32a.

Note that the base layer 2 may contain other additives as necessary. Examples of other additives include flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, and tackifiers.
In addition, when either one of the base layer 2 and the liquid-repellent layer 3 contains a filler, or when both layers 2 and 3 contain a filler, the weight of the filler contained in both these layers 2 and 3 is The total amount is preferably in the range of 3.0 to 10.6 g/m ² . When it is 3.0 g/m ² or less, the surface unevenness becomes small, and therefore the core space volume Vvc and the skewness value Ssk become small, making it difficult to exhibit excellent liquid repellency. On the other hand, even in the case of 10.6 g/m2 or ^more , the amount of filler is too large and the surface unevenness becomes small. Therefore, the core space volume Vvc and skewness value Ssk become small, and excellent liquid repellency is exhibited. difficult to do. On the other hand, when the total weight of the filler contained in both layers 2 and 3 is in the range of 3.0 to 10.6 g/m ² , appropriate unevenness is formed on the surface of the liquid-repellent layer 3 and its core portion is The spatial volume Vvc and the skewness value Ssk can be within the above-mentioned ranges.

The method for forming the base layer 2 is the same as the method for forming the liquid-repellent layer 3. That is, the base layer 2 is prepared by preparing a coating liquid containing a thermoplastic resin, the fourth filler 21 and other additives added as necessary, and a solvent, and coating the coating liquid on the base material 1. It can be formed by applying it to a surface to form a coating film and drying the coating film. The solvent used in the coating liquid, the method for applying the coating liquid, and the method for drying the coating film are the same as those for forming the liquid-repellent layer 3.

The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these examples.

These embodiments can be divided into two groups.

The first group (Examples 1-1 to 1-20, Comparative Examples 1-1 to 1-2) considers the relationship between the core space volume Vvc on the surface of the liquid-repellent layer 3 and the liquid-repellent performance. Therefore, the skewness value Ssk was not measured.

The second group (Examples 2-1 to 2-72, Comparative Examples 2-1 to 2-9) considers the relationship between the skewness value Ssk and liquid repellency performance in addition to the core space volume Vvc. The purpose is to

First, in order to produce the liquid-repellent structures according to these Examples and Comparative Examples, the following materials were prepared.

(Base material 1)
・Polyethylene terephthalate (PET) film.

(Fluorine-containing resin)
・Fluorine-based paint a: Unidyne TG-8811 (trade name, manufactured by Daikin Industries, Ltd., fluorine-acrylic copolymer having structural units derived from pyrrolidones, cationic water-based material, fluorine content 0.44% by mass) ).
・Fluorine-based paint b: Asahi Guard AG-E060 (trade name, manufactured by Asahi Glass Co., Ltd., fluorine-acrylic copolymer that does not have structural units derived from pyrrolidones, cationic water-based material, fluorine content 0.45 mass%).
・Fluorine paint c: Asahi Guard AG-E061 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint d: Asahi Guard AG-E070 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint e: Asahi Guard AG-E080 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint f: Asahi Guard AG-E081 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint g: Asahi Guard AG-E082 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint h: Asahi Guard AG-E090 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint i: Asahi Guard AG-E092 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint j: Asahi Guard AG-E100 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint k: Asahi Guard AG-E300D (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint l: Asahi Guard AG-E400 (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint m: Asahi Guard AG-E500D (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint n: Asahi Guard AG-E700D (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint o: Asahi Guard AG-E800D (product name, manufactured by Asahi Glass Co., Ltd.)
・Fluorine paint p: Asahi Guard AG-E550D (product name, manufactured by Asahi Glass Co., Ltd.)

(First filler 32a)
- Particle a: AEROSIL50 (trade name, manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 0.055 μm).
- Particle a: AEROSIL50 (trade name, manufactured by Nippon Aerosil Co., Ltd., average primary particle diameter 0.03 mm).

(Second filler 32b)
- Particle c: Sun Lovely (trade name, manufactured by AGC SI Tech Co., Ltd., average primary particle diameter 5 μm).
- Particle d: Sunsphere NP-30 (trade name, manufactured by AGC SI Tech Co., Ltd., average primary particle diameter 4 μm).
- Particle e: Flow beads LE-1080 (trade name, manufactured by Sumitomo Seika Co., Ltd., average primary particle diameter 6 μm).
- Particle f: Chemisnow MR-5C (trade name, manufactured by Soken Chemical Co., Ltd., average primary particle diameter 6 μm).
- Particle g: Chemisnow MR-7GC (trade name, manufactured by Soken Chemical Co., Ltd., average primary particle diameter 6 μm).
- Particle h: Art Pearl SE-006T (trade name, manufactured by Negami Kogyo Co., Ltd., average primary particle diameter 6 μm).
- Particle i: Seahoster WSO (trade name, manufactured by Nippon Shokubai Co., Ltd., average primary particle diameter 0.5 μm).

(Third and fourth fillers 32c, 21)
- Particle j: Sunsphere NP-100 (trade name, manufactured by AGC SI Tech Co., Ltd., average primary particle diameter 10 μm).
- Particle k: Sunsphere NP-200 (trade name, manufactured by AGC SI Tech Co., Ltd., average primary particle diameter 20 μm).
- Particle 1: HS-304 (trade name, manufactured by Nippon Steel Chemical & Materials Co., Ltd., average primary particle diameter 28 μm).
- Particle m: HS-208 (trade name, manufactured by Nippon Steel Chemical & Materials Co., Ltd., average primary particle diameter 20 μm).
- Particle n: HS-312 (trade name, manufactured by Nippon Steel Chemical & Materials Co., Ltd., average primary particle diameter 9.5 μm).
- Particle o: Flow beads CL-2080 (trade name, manufactured by Sumitomo Seika Co., Ltd., average primary particle diameter 11 μm).
- Particle p: Art Pearl GR-500 (trade name, manufactured by Negami Kogyo Co., Ltd., average primary particle diameter 10 μm).
- Particle q: Art Pearl GR-600 (trade name, manufactured by Negami Kogyo Co., Ltd., average primary particle diameter 10 μm).
- Particle r: Art Pearl SE-010T (trade name, manufactured by Negami Kogyo Co., Ltd., average primary particle diameter 10 μm).
- Particle s: Art Pearl SE-015TY (trade name, manufactured by Negami Kogyo Co., Ltd., average primary particle diameter 15 μm).
- Particle t: Art Pearl SE-020T (trade name, manufactured by Negami Kogyo Co., Ltd., average primary particle diameter 19 μm).
- Particle u: Chemisnow MR-10G (trade name, manufactured by Soken Kagaku Co., Ltd., average primary particle diameter 10 μm).
- Particle v: QSG-30 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., average primary particle diameter 30 μm).
- Particle w: QSG-80 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., average primary particle diameter 80 μm).

(Thermoplastic resin)
- Resin a: Auroren AE-301 (trade name, manufactured by Nippon Paper Industries Co., Ltd., modified polyolefin, melting point 60-70°C).
- Resin b: Auroren AE-202 (trade name, manufactured by Nippon Paper Industries Co., Ltd.).
- Resin c: Auroren S-6499 (trade name, manufactured by Nippon Paper Industries Co., Ltd.).
- Resin d: Zaixen A (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin e: Zaixen AC (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin f: Zaixen AC-HW-10 (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin g: Zaixen L (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin h: Zaixen N (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin i: Zaixen NC (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin k: Sevolsion VA (trade name, manufactured by Sumitomo Seika Co., Ltd.).
-Resin l: Sevolsion VA406N (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin m: Sevolsion VA407N (trade name, manufactured by Sumitomo Seika Co., Ltd.).
- Resin n: Arrowbase DA-1010 (trade name, manufactured by Unitika Co., Ltd.).
- Resin o: Arrowbase DA-5010 (trade name, manufactured by Unitika Co., Ltd.).
- Resin p: Arrowbase DB-4010 (trade name, manufactured by Unitika Co., Ltd.).
- Resin q: Arrowbase DB-5010 (trade name, manufactured by Unitika Co., Ltd.).
- Resin r: Arrowbase SB-1200 (trade name, manufactured by Unitika Co., Ltd.).
- Resin S: Arrowbase SD-1200 (trade name, manufactured by Unitika Co., Ltd.).
- Resin t: Arrowbase SD-5200 (trade name, manufactured by Unitika Co., Ltd.).
- Resin u: Arrowbase SE-1200 (trade name, manufactured by Unitika Co., Ltd.).
- Resin v: Arrowbase SE-5230N (trade name, manufactured by Unitika Co., Ltd.).

(solvent)
- Alcohol solvent (2-propanol).

[First Group (Examples 1-1 to 1-20, Comparative Examples 1-1 to 1-2)]
<Preparation of liquid repellent structure>
(Examples 1-1 to 1-17)
Each component was added to the solvent so that the mass ratio (solid content) of each component in the liquid-repellent layer 3 was as shown in Examples 1-1 to 1-17 in Table 1. This was sufficiently stirred to prepare a coating liquid for forming a liquid-repellent layer, which was coated onto a PET film as a base material using a bar coater. Thereafter, the applied coating liquid was heated at 80° C. for 1 minute to dry and harden, thereby forming a liquid-repellent layer on the substrate.

(Examples 1-18 to 1-20 and Comparative Examples 1-1 to 1-2)
Each component was dissolved in a solvent so that the mass ratio (solid content) of each component in base layer 2 was as shown in Examples 1-18 to 1-20 and Comparative Examples 1-1 to 1-2 in Table 1. added. This was thoroughly stirred to prepare a coating solution for forming a base layer, and the coating solution was coated onto a PET film as a base material using a bar coater. Thereafter, the applied coating liquid was heated and dried at 80° C. for 1 minute to form a base layer on the substrate.

Next, each component was added to the solvent so that the mass ratio (solid content) of each component in the liquid repellent layer was as shown in Examples 1-18 to 1-20 and Comparative Examples 1 to 2 in Table 1. Ta. This was sufficiently stirred to prepare a coating liquid for forming a liquid-repellent layer, which was coated on the base layer 2 using a bar coater. Thereafter, the applied coating liquid was heated at 80° C. for 1 minute to dry and harden, thereby forming a liquid-repellent layer on the base layer.

In Table 1, "filler weight (g/m ² )" indicates the total amount of filler contained in the liquid-repellent layer, and "filler compounding ratio (wt%)" indicates the total amount of filler contained in the liquid-repellent layer 100 The percentage of each filler is shown in %.

Further, the core space volume Vvc was measured according to JIS B0681-2. As a measuring instrument, OLS4000 manufactured by Olympus Corporation was used. The measurement magnification is 20x, and the measurement mode is multilayer. Then, after performing smoothing correction to remove minute noise when the laser hits the measurement target during measurement and surface correction (tilt) used when the measurement surface is sloped, 3D measurement is performed. The core space volume Vvc was measured.

<Evaluation of liquid repellent structure>
The liquid-repellent structure was evaluated from the following viewpoints.
(liquid repellency evaluation)
The liquid-repellent structure was placed flat with the liquid-repellent layer facing upward, and 2 μL of the following liquid was dropped onto the liquid-repellent layer using a dropper. Thereafter, the liquid repellent structure was stood vertically, left as it was for 30 seconds, and the state of the dropped liquid was visually observed. From the observation results, liquid repellency was evaluated based on the following evaluation criteria. If the evaluation result is A to D, it can be said that there is no problem in practical use. It is desirable that the evaluation result be A to C.

[Liquid used]
Pure water salad oil: Nissin salad oil (Nissin Oilio).
Hand soap: Kurashimore medicated hand soap (Japanese soap).
Shampoo: Shampoo (7-Eleven) that thoroughly cleanses the scalp.

[Evaluation criteria]
A: Droplets became round and rolled down from above the water-repellent layer. Or it peeled off.
B: It ran down from above the liquid repellent layer, leaving no trace of flow.
C: It ran down from above the liquid repellent layer, but traces of the flow remained in the form of dots.
D: It ran down from above the liquid repellent layer, but traces of the flow remained in a linear shape.
E: It remained on the liquid repellent layer and did not move. Or it has soaked into the liquid repellent layer.

(Adhesion evaluation)
Adhesion to viscous foods was evaluated using the following method. A polypropylene (PP) film was laid flat, and 2 g of the following viscous food was collected with a spoon and dropped onto the PP film. The liquid-repellent structure was placed so that the surface on the liquid-repellent layer side faced the PP film, and it was pressed against the viscous food with a load of 50 g/25 cm ² and left to stand for 10 seconds. Thereafter, the liquid-repellent structure was peeled off, and the state of adhesion of the viscous food to the contact surface of the liquid-repellent layer that had been in contact with the viscous food was visually observed. Adhesion was evaluated from the observation results based on the following evaluation criteria. If the evaluation result is A to D, it can be said that there is no problem in practical use. It is desirable that the evaluation result be A to C.

[Viscous food used]
Mayonnaise: Kewpie Mayonnaise (Kewpie Corporation).

[Evaluation criteria]
A: No viscous food was observed on the contact surface.
B: Adhesion of viscous food was observed on less than 10% of the contact surface.
C: Adhesion of viscous food was observed on 10% or more and less than 30% of the contact surface.
D: Adhesion of viscous food was observed on 30% or more and less than 70% of the contact surface.
E: Adhesion of viscous food was observed on 70% or more of the contact surface.

The results are shown in Table 2.

[Second Group (Examples 2-1 to 2-72, Comparative Examples 2-1 to 2-9)]
<Preparation of liquid repellent structure>
A liquid-repellent structure was manufactured in the same manner as in the first group, except that the materials and coating amounts of each component in the liquid-repellent layer and the base layer were changed.
In addition, the core space volume Vvc was also measured in the same manner as in the first group.

In this second group, in addition to the core space volume Vvc, the skewness value Ssk was also measured. The skewness value Ssk was also measured in accordance with JIS B0681-2 in the same way as the core space volume Vvc. The measuring device was OLS4000 manufactured by Olympus Corporation, the measurement magnification was 20 times, and the measurement mode was multilayer. Further, after performing smoothing correction and surface correction (inclination), the skewness value Ssk was measured by three-dimensional measurement.

The results are shown in Tables 3 to 8.

<Evaluation of liquid repellent structure>
For the second group, similarly to the first group, the liquid repellency against pure water, salad oil, hand soap, and shampoo was evaluated. If the evaluation result is A to D, it can be said that there is no problem in practical use. It is desirable that the evaluation result be A to C.

In addition, the adhesion to mayonnaise was similarly evaluated. If the evaluation result is A to D, it can be said that there is no problem in practical use. It is desirable that the evaluation result be A to C.

The results are shown in Tables 9 to 14.

A to G: Liquid repellent structure 1: Base material 2: Base layer 21: Fourth filler 3: Liquid repellent layer 31: Binder resin 32: Filler 32a: First filler 32b: Second filler 32c: Fourth 3 filler

Claims (12)

A liquid repellent structure comprising a surface to be imparted with liquid repellency and a liquid repellent layer formed on the surface,
Liquid repellency characterized in that the liquid repellent layer contains a binder resin containing a fluorine-containing resin, and the core space volume on the surface of the liquid repellent layer is in the range of 4 to 10 μm ³ /μm ² Structure. The liquid repellent structure according to claim 1, wherein the skewness value of the surface of the liquid repellent layer is in the range of 0.0 to 0.3. The liquid-repellent structure according to claim 1 or 2, wherein the liquid-repellent layer contains a filler dispersed in the binder resin. 4. The liquid-repellent structure according to claim 3, wherein the liquid-repellent layer contains two or more types of fillers having different average primary particle diameters. The liquid-repellent structure according to claim 3 or 4, wherein at least one type of filler among the fillers has an average primary particle diameter of 8 to 30 μm. The liquid-repellent structure according to any one of claims 3 to 5, wherein the total weight of the filler is in a range of 3.0 to 10.6 g/m ² . The liquid-repellent structure according to any one of claims 1 to 6, wherein the liquid-repellent layer further contains a thermoplastic resin. The liquid-repellent structure according to any one of claims 1 to 7, further comprising a base layer disposed between the surface to which liquid repellency is to be imparted and the liquid-repellent layer. The liquid-repellent structure according to claim 8, wherein the base layer contains a filler having an average primary particle size of 8 to 30 μm. A packaging material comprising the liquid-repellent structure according to any one of claims 1 to 9 on a side that comes into contact with an article. preparing a coating liquid containing a binder resin containing a fluorine-containing resin;
forming a coating film of the coating liquid on the surface to which liquid repellency is to be imparted;
forming a liquid-repellent layer by drying and curing the coating film,
A method for manufacturing a liquid-repellent structure, characterized in that the core space volume on the surface of the liquid-repellent layer is in the range of 4 to 10 μm ³ /μm ² . 12. The method for manufacturing a liquid-repellent structure according to claim 11, wherein the skewness value of the surface of the liquid-repellent layer is set in a range of 0.0 to 0.3.

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