JP7315428B2 - POROUS BODY WITH LIQUID-REPELLENT MEMBRANE AND ARTICLE USING THE SAME - Google Patents

Description

TECHNICAL FIELD The present invention relates to a porous body with a liquid-repellent film.

It is very important to impart liquid repellency such as water and oil repellency to the surface of an article. In particular, high-viscosity liquids, semi-solids, gel-like substances, etc. tend to adhere, and various problems arise due to this. In the case of a highly viscous substance such as cosmetic cream, a container with a wide-mouthed lid (jar container) is often used as the container, but when the lid is opened during use, a large amount of cream often adheres to the inside of the lid. In some cases, the adhered cream is hesitant to use and is discarded as it is. In addition, it looks bad and is regarded as a problem as a cosmetic that values the brand image.

There is also a countermeasure such as placing a thin sheet between the cream in the container and the lid, but instead of the lid, the cream only adheres to the thin sheet, and moreover, the task of removing the thin sheet with the cream adhered increases when using the container. Ultimately, the cream that adheres to the thin sheet is discarded, and it cannot be said that the fundamental problem of preventing the cream from adhering has been solved.

Techniques for imparting an anti-adhesion function to the surface of an article by applying a liquid-repellent agent are known. For example, Patent Document 1 describes an invention of an oil-repellent coating comprising primary unevenness formed from fine particles having a particle size of 100 nm or more, secondary unevenness formed from fine particles having a particle size of 7 to 90 nm, and an oil-repellent agent coated on the secondary unevenness on the surface of an article.

JP 2011-140625 A

However, in the case of the film formed of fine particles and an oil-repellent agent described in Patent Document 1, the durability of the film is poor, and it was necessary to improve the durability in order to put it to practical use. Further, the oil-repellent film of Patent Document 1 exhibits liquid-repellency against relatively low-viscosity liquids such as water and oleic acid, but there is room for improvement in liquid-repellency against high-viscosity substances such as cream.

SUMMARY OF THE INVENTION An object of the present invention is to provide an article which can impart excellent liquid repellency to a highly viscous substance to the surface of the article and has excellent durability.

A porous body with a liquid-repellent film according to one aspect of the present invention comprises:
a porous body having an uneven surface structure formed by pores;
Hydrophilic fine particles arranged on the surface of the porous body and forming an uneven structure portion that is finer than the surface uneven structure portion;
a liquid-repellent portion that bonds to the surface of the fine uneven structure;
and a binder resin distributed so as to cover a joint portion between the fine concave-convex structure portion and the liquid-repellent portion.

Further, the porous body with a liquid-repellent film according to one aspect of the present invention includes:
a porous body having an uneven surface structure formed by pores;
an undercoat portion that forms an intermediate uneven structure portion smaller than the surface uneven structure portion on the surface of the porous body by intermediate fine particles and a thermoplastic resin;
and a top coat portion formed on the surface of the undercoat portion,
The top coat portion is
Hydrophilic fine particles forming a concave-convex structure portion that is finer than the intermediate concave-convex structure portion;
a liquid-repellent portion that bonds to the surface of the fine uneven structure;
and a binder resin distributed so as to cover a joint portion between the fine concave-convex structure portion and the liquid-repellent portion.

According to the porous body with a liquid-repellent film having the above configuration, a liquid-repellent coating consisting of a fine concave-convex structure part made of hydrophilic fine particles, a liquid-repellent part bonded to the surface, and a binder resin having no liquid-repellent part is formed on the surface concave-convex structure of the porous body or the intermediate concave-convex structure of the undercoat part, and the liquid repellency is maintained by the liquid-repellent part on the surface of the film. In particular, on the surface of the film, a fine uneven structure is formed by a large number of hydrophilic fine particles, and on the surface of the uneven structure, a large number of liquid-repellent portions are oriented outward, so that the liquid-repellent portions can exhibit excellent liquid repellency. In addition, the binder resin firmly fixes the fine concave-convex structure formed by the hydrophilic fine particles to the surface of the porous body or the surface of the undercoat, and also firmly fixes the liquid-repellent portion to the surface of the fine concave-convex structure. Therefore, it is possible to provide a liquid-repellent membrane-coated porous body with improved durability.

In addition, since the fine uneven structure portion formed by the hydrophilic fine particles is hierarchically formed on the surface of the relatively large uneven surface structure formed by the pores of the porous body, a large and complicated uneven structure can be obtained as a whole. As a result, excellent liquid repellency against high-viscosity substances can be exhibited.

In the porous body with a liquid-repellent film, it is preferable that the porous body is a foamed resin. Further, in the liquid-repellent porous body with a film, the arithmetic mean roughness (Sa) of the surface of the uneven surface structure portion formed by the pores is preferably 1.5 times or more and 30 times or less than the arithmetic mean roughness of the surface of the fine uneven structure portion formed by the hydrophilic fine particles.

In the liquid-repellent porous body with a film, the hydrophilic fine particles may be hydrophilic silica fine particles, and the binder resin may be a vinyl resin. In particular, the binder resin may be a copolymer of vinyl chloride resin and vinyl acetate resin. By using hydrophilic silica fine particles, it is possible to provide a liquid-repellent film that is more excellent in liquid repellency than other hydrophilic oxide fine particles. Considering both the effect of the binder resin on durability and coatability, a combination of hydrophilic silica fine particles and a vinyl resin is preferable.

Articles according to another aspect of the present invention, such as packings and packaging materials, are obtained by using the above-described porous body with a liquid-repellent film on its surface. Further, a packaging container according to another aspect of the present invention uses the porous body with a liquid-repellent film as the inner surface of the lid member. The liquid-repellent film-coated porous body is used to form the surfaces of various articles such as the inner surface of the lid of a cosmetic jar.

According to the present invention, first, it is possible to provide a porous body with a liquid-repellent film having excellent durability. As for the anti-adhesion effect, although a similar top coat is laminated on a non-porous surface, and an undercoat and a top coat are both laminated, the anti-adhesion effect of cream etc. is recognized, but the effect of anti-adhesion to highly viscous substances is not sufficient and is not practical. In addition, although the adhesion prevention effect is recognized to some extent due to the presence of a large number of pores on the surface of the porous body, the effect is still low and not practical. According to the present invention, by laminating a liquid-repellent top coat on the surface of the porous body, the effect of preventing the adhesion of high-viscosity substances such as cream is enhanced. In addition, by laminating an undercoat between the porous body and the topcoat, the adhesion prevention effect was further enhanced.

(A) is a schematic cross-sectional view of a porous body with a liquid-repellent film according to the first embodiment, and (B) is a schematic diagram of a liquid-repellent film formed along the inner walls of pores on the surface of the porous body, which is a substrate. FIG. 2 is a schematic cross-sectional view of a top coat that constitutes the liquid-repellent film of FIG. 1; FIG. 3 is a diagram schematically showing a cross-sectional structure of the top coat of FIG. 2; FIG. 6 is a schematic diagram of a liquid-repellent film formed along the inner walls of pores on the surface of a porous body that is a substrate in a porous body with a liquid-repellent film according to a second embodiment. FIG. 5 is a schematic cross-sectional view of an undercoat and a topcoat that constitute the liquid-repellent film of FIG. 4; (A) to (E) are diagrams for explaining the cream adhesion test method. 1 is a graph showing the effect of reducing the amount of cream A adhered when a liquid-repellent film is formed on the surface of a porous body, where (A) shows the effect when the porous body is foamed PE (Example 2), and (B) shows the effect when the porous body is a foamed coating film (Examples 3 and 4). 5 is a graph showing the effect of reducing the adhesion amount of cream B when a porous material is employed as the base material of the liquid-repellent film (Examples 1 and 2). FIG. 10 is a graph showing that forming a liquid-repellent film of an undercoat and a topcoat (Examples 2 and 4) on the surface of a porous body is more effective in reducing the adhesion amount of creams A to C than forming a liquid-repellent film of only a topcoat (Examples 1 and 3). 1 is a graph showing the effect of reducing the amount of cream C adhered when a liquid-repellent film is formed on the surface of a porous body, where (A) shows the effect when the porous body is foamed PE (Examples 1 and 2), and (B) shows the effect when the porous body is a foamed coating film (Example 4). 5 is a graph showing the effect of reducing the adhesion amount of cream D when a liquid-repellent film is formed on the surface of PE foam (Example 2). 5 is a graph showing the effect of reducing the adhesion amount of cream E when a liquid-repellent film is formed on the surface of foamed PE (Example 2). 10 is an image showing the results of the cream adhesion test of Comparative Example 5 and Example 2. FIG. 5 is a graph showing the effect of reducing the amount of adhered cream of a porous body with a liquid-repellent film.

Preferred embodiments of the liquid-repellent membrane-coated porous body of the present invention will be described with reference to the drawings.

As shown in FIG. 1A, the liquid-repellent film-coated porous body 1 of the first embodiment includes a sheet-like porous body 3 having a large number of pores 2 and an uneven surface structure formed by the pores 2, and a liquid-repellent film 4 formed on at least one surface of the porous body 3.

<Base material>
In this embodiment, the porous body 3 on which the liquid-repellent film 4 is formed is referred to as a substrate. If any article has the surface of the porous body 3, such article becomes the base material. In addition, even if the surface of the article itself is not the porous body 3, if a sheet-like porous body 3 is attached thereon or a layer of the porous body 3 is formed by coating, such an article can also be used as a base material. Any article whose surface is desired to have liquid repellency can be used as the base material, without being limited to any particular article. For example, general industrial products, their parts, members, and equipment, housing-related materials such as wall materials, kitchens, interiors, and exteriors, various daily necessities related to daily life, and container and packaging materials such as food, medicine, and cosmetics are the base materials. In particular, the inside of the lid of a cosmetic jar is suitable as a substrate.

The porous body 3 is preferably solid at room temperature, but is not limited to this. Various plastics, glasses, papers, ceramics, metals, composites thereof, and the like can be used as the material of the porous body 3 . Plastics and their composites are particularly suitable as the material for the porous body 3 because they are easy to process to make them porous and easy to control the shape of the pores.

The shape of the porous body 3 may be square, spherical, or various other shapes depending on the product.

The porous body 3 refers to a body having at least a porous surface. The shape and size of the porous pores 2 are not particularly limited. However, if the size of the pores 2 is too large, even with the concave-convex structure, it becomes difficult to exhibit liquid repellency against adhering matter, and the effect of preventing the adhesion of the porous body 3 is weakened. Further, if the size of the pores 2 is too small, the liquid-repellent film 4 is laminated on the surface of the porous body 3, so that the openings of the pores 2 are blocked by the liquid-repellent film, and the effect of preventing the adhesion of the porous body 3 is weakened. Therefore, it is preferable that the pores 2 have an average diameter of 5 to 500 μm. Moreover, the open area ratio of the pores 2 is preferably 5 to 80% of the surface area of the porous body 3 . The uneven surface structure formed by the pores 2 tends to form air pockets when an adhering substance comes into contact with the surface thereof, and easily exerts an effect of preventing adhesion.

The method for forming the porous body 3 is not particularly limited as long as the surface of the obtained substrate is at least porous. For example, it is preferable to mix a substance such as a foaming agent that forms the pores 2 with the material of the base material, form the base material using this material, foam it by heat treatment or the like, and break the foam as necessary. As a result, a large number of pores 2 are formed on the surface of the substrate. Other conceivable methods include making the surface of the base material porous by pressing fine needles against the base material being formed, or mixing specific fine particles into the base material and removing the fine particles after forming the product. Generally, any method for creating a porous layer can be used.

Although the thickness of the substrate is not particularly limited, the thickness of the film is generally 1 to 200 μm, and the thickness of the sheet is generally 200 to 10,000 μm.

<Top coat part>
Next, a liquid-repellent film 4 is laminated so as to cover the surface of the uneven surface structure formed by the pores 2, as shown in an enlarged view of FIG. 1(B). The liquid-repellent film 4 of this embodiment is composed of a topcoat portion. The topcoat portion contains hydrophilic fine particles 5 that are arranged along the surface of the porous body 3 and form an uneven structure portion that is finer than the surface uneven structure portion formed by the pores 2 . Furthermore, as shown in an enlarged view in FIG. 2, the top coat portion includes a liquid-repellent portion 6 that bonds to the surface of the fine uneven structure, and a binder resin 7 that is distributed so as to cover the joint portion between the fine uneven structure and the liquid-repellent portion 6.

As also shown in FIG. 3, the fine concave-convex structure is formed of a large number of hydrophilic fine particles 5 connected in a beaded manner and fixed to the surface of the porous body 3 with a binder resin 7 . The liquid-repellent portion 6 is bonded to the hydrophilic fine particles 5, and the bonding portion is covered with the binder resin 7, and the tip of the liquid-repellent portion 6 is oriented outward.

Examples of the hydrophilic fine particles 5 include silica, titanium oxide, zinc oxide, and aluminum oxide, and hydrophilic silica fine particles are preferable. The particle size is preferably 5 to 100 nm as an average primary particle size. As shown in the enlarged view of FIG. 3, the hydrophilic fine particles 5 are connected to each other in a beaded manner by the metal alkoxide 8 .

The binder resin 7 is preferably a vinyl resin, more preferably a copolymer of vinyl chloride resin and vinyl acetate resin.

Perfluoroalkylsilane (FAS) having a fluoro group is suitable for the liquid-repellent portion 6 . In the process of laminating the topcoat, the reactive group portion (Si) of FAS is bound to the hydrophilic fine particles 5, and the fluoro group, which is the liquid-repellent portion 6, is oriented outward, and is covalently bonded to the surface of the fine uneven structure of the hydrophilic fine particles 5.

FAS is obtained by substituting some of the alkyl groups of alkylsilanes with fluorocarbon groups (perfluoro groups). )3(CH2)2Si(OCH3)3, CF3(CF2)7(CH2)2SiCl3, among them, C8 heptadecafluorodecyltrimethoxysilane, C6 tridecafluorooctyltrimethoxysilane, or C4 nonafluorohexyltrimethoxysilane is preferred, and C6 tridecafluorooctyltrimethoxysilane is more preferred in terms of safety and oil repellency.

Although the thickness of the topcoat portion is not particularly limited, it is preferably 0.1 to 5.0 μm.

In this way, the liquid-repellent portion 6 is covalently bonded to the hydrophilic fine particles 5, the hydrophilic fine particles 5 are linked to each other by the metal alkoxide 8, and the covalent bonds and the linking portions are covered with the binder resin 7. Thus, the coating film is more durable than conventional liquid-repellent materials.

The porous body 11 with a liquid-repellent film of the second embodiment includes a similar porous body 3, but differs from the first embodiment in that the liquid-repellent film 14 has a two-layer structure consisting of an undercoat portion and a topcoat portion. As the liquid-repellent film laminated on the porous body 3, only the top coat portion may be used like the film 4, but further effects can be obtained by laminating an undercoat portion therebetween like the film 14.

<Undercoat part>
As shown in the enlarged view of FIG. 4 , the undercoat portion contains intermediate fine particles 9 to form an intermediate concave-convex structure portion on the surface of the porous body 3 . The undercoat portion also contains a thermoplastic resin 17 for holding the intermediate fine particles 9 on the surface of the porous body 3, as shown in the enlarged view of FIG.

The top coat portion is laminated along the surface of the undercoat portion. The topcoat portion includes the liquid-repellent portion 6 and the binder resin 7 as in the first embodiment.

In descending order of size, the diameter of the pores 2, the diameter of the intermediate fine particles 9, and the diameter of the hydrophilic fine particles 5 are obtained. In other words, on the surface of the relatively coarse uneven surface structure formed by the pores 2, an intermediate fine uneven structure formed by the intermediate fine particles 9 is formed, and on the surface of the intermediate uneven structure formed by the hydrophilic fine particles 5, a fine uneven structure is formed. The concave-convex structure formed by the fine pores 2 and the two types of fine particles, respectively, provides a complex concave-convex structure that is large and rough as a whole and fine locally, and has the effect of further enhancing the liquid repellency.

Thus, it is preferable to make the minimum particle size of the intermediate fine particles 9 in the undercoat portion larger than the maximum particle size of the hydrophilic fine particles 5 in the topcoat portion. Moreover, it is preferable to make the maximum particle size of the intermediate fine particles 9 smaller than the pore size of the pores 2 .

Although there is no particular limitation as the intermediate fine particles 9, silica beads are suitable. Silica beads include crystalline silica and amorphous silica (dry silica, wet silica, silica gel, etc.), and known ones can be used as appropriate. The shape of the silica beads is not particularly limited, and various shapes such as polyhedral and uneven shapes can be selected.

The thermoplastic resin 17 is not particularly limited, but polyester, polyolefin, polystyrene, nylon, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, acrylonitrile-butadiene-styrene copolymer, ethylene-vinyl acetate copolymer, polyacetal, polymethyl methacrylate, methacryl-styrene copolymer, cellulose acetate, polyurethane, polycarbonate, and the like are used.

The undercoat portion is formed by coating the porous body 3 with an undercoat liquid obtained by dissolving or dispersing the intermediate fine particles 9 and the thermoplastic resin 17 in a solvent and drying the liquid. The solvent is not particularly limited as long as it dissolves the thermoplastic resin 17 to be used. Examples thereof include hydrocarbons such as n-hexane, cyclohexane, toluene, benzene, and xylene, ketones such as acetone and methyl ethyl ketone, and alcohols.

Although the thickness of the thermoplastic resin 17 in FIG. 5 is not particularly limited, it is slightly smaller than the particle size of the intermediate fine particles 9 . In other words, the undercoat portion is formed in a state in which the intermediate fine particles 9 are not entirely embedded in the thermoplastic resin 17 but partially out of the thermoplastic resin 17 .

In the above-described first embodiment, the top coat portion having the hydrophilic fine particles 5 to which the liquid-repellent portions 6 are bonded and the binder 7 is laminated on the surface of the porous body 3 having a large uneven surface structure formed by the pores 2, thereby exhibiting high liquid-repellent performance and making it possible to prevent the adhesion of substances that are very likely to adhere, such as high-viscosity liquids and gel-like substances.

Further, in the second embodiment, by laminating an undercoat portion between the porous body 3 and the topcoat portion, a large uneven surface structure due to the pores 2, an intermediate fine uneven structure due to the intermediate fine particles 9, and a fine uneven structure due to the hydrophilic fine particles 5 are respectively formed, thereby obtaining even higher liquid repellency. The undercoat not only provides an intermediate uneven structure of intermediate fineness, but also firmly binds the topcoat to the porous body 3, making the liquid-repellent film stronger and more durable.

For such a stepwise uneven structure, for example, the value obtained by measuring the arithmetic mean roughness (Sa) of the surface of the uneven surface structure due to the pores 2 may be in the range of 1.5 times or more and 30 times or less than the measured value of the arithmetic mean roughness of the surface of the uneven structure formed by the undercoat and topcoat.

In each of the above embodiments, a porous body with a liquid-repellent film having excellent liquid repellency and durability can be obtained, and articles such as packings, packaging materials, and packaging containers formed therefrom can be provided. In particular, in packaging containers such as cosmetic jars, it is preferably applied to the inner surface of the lid.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

The following three types of substrates were used.
・Expanded polyethylene sheet (foamed PE); thickness 130 μm
(Foam layer 80 μm, sealant layer 50 μm)
・ Biaxially oriented polypropylene sheet (OPP); thickness 60 μm
・Low density polyethylene sheet (LDPE); thickness 150 μm

A coating liquid for undercoating was prepared with the following composition.
・ Intermediate fine particles; silica beads … 14% blending ratio
・Thermoplastic resin; Olefin resin・・・Composition ratio 24%
・Solvent・・・・・・・・・・・・・・・Composition ratio 62%

The coating liquid for the top coat was prepared according to the following formulation.
・Hydrophilic fine particles ; Hydrophilic silica fine particles・・・・・・・・・・・Ratio 7%
・Binder resin ；Vinyl chloride resin・・・・・・・・・・・・・・・4%
・Metal alkoxide; tetraethyl orthosilicate (TEOS) ・Composition ratio 5%
・Liquid-repellent part: perfluoroalkylsilane (FAS): compounding ratio: 1%
・Hydrolysis catalyst;
・Solvent・・・・・・・・・・・・・・・・・・・・・・・・・・・82.7%

As deposits, the following five types of cosmetic creams (all for skin care) were used.
・ Cream A; surface tension 30.2 mN/m, viscosity 119860 mPa s
・ Cream B; surface tension 29.5 mN/m, viscosity 84160 mPa s
・ Cream C; surface tension 31.3 mN/m, viscosity 79850 mPa s
・ Cream D; surface tension 31.7 mN/m, viscosity 76490 mPa s
・ Cream E; surface tension 28.6 mN / m, viscosity 98850 mPa s
Among these, "Cream E" was considered to be the most severe contaminant because of its low surface tension and relatively high viscosity. The surface tension can be measured using a plate-type surface tensiometer "CBVP-Z" manufactured by Kyowa Interface Science Co., Ltd., and measured at 24°C. In addition, the viscosity can be measured using a Thermo Scientific HAAKE B-type viscometer "VT6L/R type" (spindle L3 (ISO2555 compliant), number of revolutions: 0.3 rpm), and measured at 24°C.

Test pieces for Examples 1 and 2 and Comparative Examples 1 to 5 below were prepared.
<Example 1> A base material of foamed PE was coated with the above-described topcoat coating liquid and dried to produce a base material.
<Example 2> The base material of foamed PE was coated with the above-mentioned undercoat coating liquid and dried, and then the above-mentioned topcoat coating liquid was coated and dried.
<Comparative Example 1> An OPP base material was used as it was.
<Comparative Example 2> An OPP base material was coated with the above topcoat coating liquid and dried to produce a topcoat.
<Comparative Example 3> An OPP base material was prepared by coating and drying the above-described undercoat coating liquid, and then coating and drying the above-described topcoat coating liquid.
<Comparative Example 4> An LDPE base material was used as it was.
<Comparative Example 5> A foamed PE base material was used as it was.

<Test method>
An adhesion test using cream was performed on the test pieces of Examples 1 and 2 and Comparative Examples 1-5. The procedure will be described with reference to FIG. First, put the cream in a cap with an outer diameter of φ38 mm (inner diameter of φ30 mm) and a height of 8 mm (made of PE, FIG. 6(A) is an image of the cap viewed from directly above), and scraped horizontally with a spatula (FIG. 6(B)). A sheet of the test piece is placed thereon (Fig. 6(C)), the entire container is turned over, and the container is turned upside down (Fig. 6(D)) and held for 1 minute. Thereafter, the container is returned to its original upright position, the sheet of the test piece is peeled off, the state of adhesion of the cream to the test piece is confirmed, and the amount of adhesion is measured (Fig. 6(E)). The weight of the cap is 1.7 g, and the weight of the cream contained in the cap varies depending on the cream. For example, cream B weighs 5.4 g. With the cream added, the weight of the cap before placing the test piece and the weight of the cap after peeling off the test piece were measured, and the amount of cream adhered to the test piece was obtained from the difference. Three test pieces were tested, and the average value was taken as the amount of cream adhered. Table 1 shows the test results.

Also, test pieces of Examples 3 and 4 and Comparative Example 6 were prepared as follows. As a common matter, a non-porous PET sheet with a thickness of 188 μm was used. In Examples 3 and 4, a commonly used organic foaming resin paint was applied to the surface of the PET sheet, and the resin on the surface was foamed by heat treatment to prepare a porous coating film. This is called a foam paint coated PET sheet.

<Example 3> It was produced in the same manner as in Example 1, except that the above foamed paint-coated PET sheet was used as the base material.
<Example 4> It was produced in the same manner as in Example 2, except that the above foamed paint-coated PET sheet was used as the base material.
<Comparative Example 6> A non-porous PET sheet base material was used as it was.

The cream deposition test was performed as for Example 1. Table 1 shows the test results.

In Table 1, "top only" indicates that the liquid-repellent film is only the top coat. "Under & Top" indicates that the liquid-repellent film has a topcoat and an undercoat. "PET, foamed coating" refers to the foamed coating coated PET sheet described above.

The graph in FIG. 7 is a graph showing the effect of reducing the adhesion amount of cream A when a liquid-repellent film is formed on the surface of the base material, and (A) shows the effect when the base material is PE foam (Example 2). From the test results of cream A, it can be seen that the adhesion amount of cream A is clearly reduced when both the undercoat and topcoat are formed on the surface of the foamed PE, rather than on the surface of the foamed PE as it is. (B) shows the effect when the substrate is a foamed paint-coated PET sheet (Examples 3 and 4). From the results of the Cream A test, it can be seen that the coating amount of Cream A is clearly reduced when only the topcoat (or both the undercoat and topcoat) is formed on the surface of the foamed paint-coated PET sheet, rather than on the surface of the non-porous PET sheet.

In Example 2, in which an undercoat and a topcoat were laminated on foamed PE, the amount of cream A deposited was 9.3 mg, which is significantly reduced compared to the amount of cream A deposited in Comparative Example 5, which was 86.5 mg with only foamed PE base material. In addition, in Examples 3 and 4 in which a topcoat was laminated on the foamed coating film, and in which both an undercoat and a topcoat were laminated, the amounts of cream A adhered were 18.8 mg and 2.2 mg, which were good results compared to the amount adhered to the non-porous PET sheet of Comparative Example 6, which was 84.1 mg.
When only the non-porous OPP base material of Comparative Example 1 and only the LDPE base material of Comparative Example 4, which is non-foamed PE, were used, the amounts of cream A adhered were 340.3 mg and 288.0 mg, which are even worse results.

The graph of FIG. 8 is a graph showing the effect of reducing the adhesion amount of cream B when foamed PE is used as the base material of the liquid-repellent film (Examples 1 and 2), and shows the test results of Example 1 in which a topcoat is laminated on foamed PE and Example 2 in which both an undercoat and a topcoat are laminated on foamed PE. From the test results of cream B, it can be seen that the amount of cream B adhered was greatly reduced by changing the base material from OPP to foamed PE in either the top coat alone (Example 1) or both the undercoat and top coat (Example 2).

The graph in FIG. 9 shows that the effect of reducing the adhesion amount of the creams A to C is greater when the liquid-repellent film of the undercoat and topcoat (Examples 2 and 4) is formed on the surface of the porous body than the liquid-repellent film of the topcoat alone (Examples 1 and 3). In all test results for creams A to C, regardless of whether the substrate is foamed PE or foamed coating film, it can be seen that the case of both the undercoat and topcoat (Examples 2 and 4) is superior to the case of only the topcoat (Examples 1 and 3) in terms of cream adhesion prevention.

The graph of FIG. 10 is a graph showing the effect of reducing the amount of cream C adhered when a liquid-repellent film is formed on the surface of the porous body. (A) shows the effect when the porous body is foamed PE (Examples 1 and 2), and (B) shows the effect when the porous body is a foamed coating film (Example 4). From the test results of Cream C, it can be seen that the adhesion amount of Cream C is clearly reduced when only the topcoat (or both the undercoat and topcoat) is formed on the surface of the foamed PE of Comparative Example 5, rather than on the surface of the foamed PE as it is. It can be seen that the adhesion amount of cream C is clearly reduced when both the undercoat and topcoat are formed on the surface of the foamed paint-coated PET sheet, compared to the surface of the non-porous PET sheet.

The amount of cream C applied was 57.9 mg when only the foamed PE base material of Comparative Example 5 was used, and the amount of cream C applied was 344.0 mg in Comparative Example 1 (only the OPP base material) and 365.8 mg in Comparative Example 4 (only the LDPE base material). The amount of cream C applied to the laminate (2.7 mg of the applied amount) is much smaller. A topcoat alone or a laminate of both an undercoat and a topcoat can be a practical repellent material.

The graphs of FIGS. 11 and 12 also show the effect of reducing the adhesion amount of cream D and cream E when both the undercoat and topcoat are laminated on the surface of PE foam (Example 2). Similar to cream A, the test results for creams D and E clearly show that the amounts of creams D and E deposited are clearly reduced when both the undercoat and topcoat are laminated on the surface of PE foam (Comparative Example 5).

FIG. 13 is an image showing the results of the adhesion test of cream E of Comparative Example 5 and Example 2 described above. It can be seen that the image of Comparative Example 5 has a considerably large amount of cream adhered thereto, whereas the image of Example 2 has almost no cream adhered thereto.

Finally, the graph in FIG. 14 summarizes the adhesion test results of Examples 1-4 and Comparative Examples 1-6. As shown in the test results of Examples 1 to 4, it can be seen that the amount of cream adhered can be stably reduced by forming a liquid-repellent film on the surface of the porous base material. In particular, when both the undercoat and topcoat were formed as liquid-repellent films on the surface of the porous substrate (Examples 2 and 4), the amount of cream adhered was reduced to 50 mg or less.

Reference Signs List 1, 11 Liquid-repellent film-attached porous body 2 Pore 3 Porous body 4, 14 Liquid-repellent film 5 Hydrophilic fine particles 6 Liquid-repellent portion 7 Binder resin 8 Metal alkoxide 9 Intermediate fine particles (silica beads)
17 ... thermoplastic resin

Claims (10)

a porous body having an uneven surface structure formed by pores;
Hydrophilic fine particles arranged on the surface of the porous body and forming an uneven structure portion that is finer than the surface uneven structure portion;
a liquid-repellent portion that bonds to the surface of the fine uneven structure;
A porous body with a liquid-repellent film, comprising: a binder resin distributed so as to cover a joint portion between the fine concave-convex structure portion and the liquid-repellent portion. a porous body having an uneven surface structure formed by pores;
an undercoat portion that forms an intermediate uneven structure portion smaller than the surface uneven structure portion on the surface of the porous body by intermediate fine particles and a thermoplastic resin;
and a top coat portion formed on the surface of the undercoat portion,
The top coat portion is
Hydrophilic fine particles forming a concave-convex structure portion that is finer than the intermediate concave-convex structure portion;
a liquid-repellent portion that bonds to the surface of the fine uneven structure;
A porous body with a liquid-repellent film, comprising: a binder resin distributed so as to cover a joint portion between the fine concave-convex structure and the liquid-repellent portion. 3. The porous body with a liquid-repellent film according to claim 1, wherein said porous body is a foamed resin. The liquid-repellent porous body with a film according to any one of claims 1 to 3, wherein the arithmetic mean roughness (Sa) of the surface of the uneven surface structure portion formed by the pores is 1.5 times or more the arithmetic mean roughness of the surface of the fine uneven structure portion formed by the hydrophilic fine particles. 5. The liquid-repellent film-coated porous body according to claim 1, wherein said hydrophilic fine particles are hydrophilic silica fine particles, and said binder resin is a vinyl resin. 6. The liquid-repellent film-coated porous body according to claim 1, wherein said binder resin is a copolymer of vinyl chloride resin and vinyl acetate resin. An article formed of the liquid-repellent membrane-coated porous body according to any one of claims 1 to 6. 8. The article of claim 7 selected from packing and packaging material. A packaging container having the liquid-repellent membrane-coated porous body according to any one of claims 1 to 6 provided on the inner surface thereof. A jar container for cosmetics, comprising a lid member having the liquid-repellent membrane-coated porous body according to any one of claims 1 to 6 provided on the inner surface thereof.

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