JP2007239109A - Impermeable opening member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impermeable opening member, permeating a gas molecule such as air, but scarcely permeating water or not permeating water. <P>SOLUTION: In the impermeable opening member, a plurality of through holes are provided in a base material and each opening area of openings in which through holes are formed is ≤5 mm<SP>2</SP>and opening ratio R (%) represented by the formula R=total of opening area (mm<SP>2</SP>)/Area Uof base material (mm<SP>2</SP>)×100 is ≤50% based on area U of the base material. The impermeable opening member exhibits water repellency. The opening ratio R (%) is preferably ≤33%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water-impermeable opening member using a water-repellent compound, and more particularly to a water-impermeable opening member that transmits gas molecules such as air but hardly permeates water or does not transmit water.

  The water repellency is a property of repelling water, and in recent years, a surface exhibiting a water repellency (super water repellency) having a very high contact angle with water has been known and attracts attention. The water repellency can be expressed by a contact angle θ (°) formed by a water droplet on the surface of the substrate, and the contact angle θ (°) indicates that the water droplet is in contact with the substrate surface as shown in FIG. The angle formed between the tangent line at one of the two points and the substrate surface. Generally, when the contact angle exceeds 90 °, it is called water repellency, and when it exceeds 150 °, it is called super water repellency. As the contact angle increases, water becomes water droplets from the water film, and becomes a true sphere when it exceeds 150 °.

Conventionally, various waterproof materials using the water repellent material have been proposed.
With regard to the field where life waterproofing is required, for example, a method has been proposed in which the surface of an umbrella is water-repellent to make raindrops less likely to adhere. However, the umbrella prevents rain, but at the same time prevents wind, so there are problems that it is difficult to hold in strong winds and the umbrella is broken.
In addition, although bicycle travel on rainy days is not preferable for safety, studies have been made to attach the umbrella to a bicycle handle and attach the umbrella to improve safety during travel. However, in this case as well, since the umbrella receives wind resistance, the umbrella is essentially burdened and has the same problem.

  In order to solve such problems, materials that satisfy both air permeability and waterproof properties have been researched and developed. Examples of such air-permeable waterproof materials include opening lengths of 1 μm or more and 1.5 mm or less. There has been proposed a water-repellent net-like body in which a water-repellent treatment is applied to a net-like body in which a large number of holes having two-dimensionally are formed in parallel (see Patent Document 1).

  However, in these techniques, the air permeability and water permeability when the area ratio (opening ratio) between the opening and the non-opening is limited have not been studied.

JP 2000-290877 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a water-impermeable opening member that transmits gas molecules such as air but hardly transmits water or does not transmit water.

Means for solving the above problems are as follows. That is,
<1> A plurality of through holes are provided in the base material,
Each opening area of the opening in which the through hole is formed is 5 mm ² or less,
An opening ratio R (%) represented by the following formula is 50% or less with respect to the area U of the substrate, and is a water-impermeable opening member characterized by exhibiting water repellency.
In the water-impermeable opening member according to <1>, each opening area of the opening is made of a base material having a through hole of 5 mm ² or less, and an opening ratio R (%) represented by the above formula is 50 % Or less and exhibiting water repellency, it is possible to achieve both the permeability of gas molecules such as air and the poor permeability of water or the impermeability of water.
<2> The water-impermeable opening member according to <1>, wherein the opening ratio R (%) is 33% or less.
In the water-impermeable opening member according to the above <2>, when the opening ratio of the base material is 33% or less, permeation of gas molecules such as air is not hindered, and the poor permeability of water is further improved. can do.
<3> The water-impermeable opening member according to any one of <1> to <2>, wherein the area of the non-opening portion around the opening is one or more times the opening of the maximum area. .
In the water-impermeable opening member according to <3>, the area of the non-opening around the opening is 1 or more times larger than the opening of the maximum area, so that a gas molecule such as air The permeation of water can be further improved without impeding the permeation of water.
<4> The water-impermeable opening member according to any one of <1> to <3>, wherein the opening is formed in a mesh shape.
In the non-water-permeable opening member according to <4>, the opening is formed in a mesh shape, so that a member that improves poor permeability of water without impeding permeation of gas molecules such as air. Can be mass-produced and inexpensively obtained.
<5> The water-impermeable opening member according to any one of <1> to <3>, wherein the base material includes a water-repellent compound.
In the water-impermeable opening member according to <5>, the base material itself can be provided with water repellency by including the water-repellent compound.
<6> The water-impermeable opening member according to any one of <1> to <5>, further comprising a water-repellent layer formed of a water-repellent material containing a water-repellent compound on at least one surface of the substrate. It is.
In the water-impermeable opening member according to the above <6>, by having a water-repellent layer on at least one surface of the substrate, the surface of the substrate can be imparted with water repellency.
<7> The water-impermeable opening member according to <6>, wherein the water-repellent material includes a photocatalyst mainly composed of titanium oxide having a solid content concentration of 10% by mass or less.
In the water-impermeable opening member according to the above <7>, by containing a photocatalyst mainly composed of titanium oxide in the water repellent material, the photocatalytic activity such as antifouling property and pollutant decomposability on the substrate surface Can be granted.
<8> The water-impermeable opening member according to any one of <1> to <7>, wherein a contact angle with water is 100 ° or more.
In the water impermeable opening member described in <8>, since the contact angle with water is 100 ° or more, high water repellency can be exhibited.

  According to the present invention, a conventional problem can be solved, and a water-impermeable opening member that transmits gas molecules such as air but hardly permeates water or does not permeate water can be provided.

(Non-permeable opening member)
The non-water-permeable opening member of the present invention is composed of a base material provided with a plurality of through-holes, and if necessary, (1) an aspect in which the base material contains a water-repellent compound, and (2) at least of the base material It is preferable that it is an aspect which consists of a base material of at least any one of the aspect which has the water repellent layer formed with the water repellent material containing this water repellent compound on one surface.
Here, the “non-water-permeable opening member” means a member having a through-hole that transmits gas molecules such as air but does not easily transmit water or does not transmit water.
The “water” here has a surface tension value of 72 to 73.5 dyn / cm at 20 ° C. and 1 atm.

<Base material>
The base material is provided with a plurality of through holes.
As shown in FIGS. 2 and 3, the base material includes an opening in which the through hole is formed and a non-opening in which the through hole is not formed.
FIG. 2 is a schematic diagram of a base material in which the opening has a square shape, and FIG. 3 is a schematic diagram of a base material in which the opening has a circular shape.

  There is no restriction | limiting in particular as a shape of the said opening part, According to the objective, it can select suitably, For example, polygonal shapes, such as a triangle, a quadrangle, and a pentagon, circular shape, an ellipse shape, a star shape, etc. are mentioned. Among these, it is preferable that the opening has a circular shape, an elliptical shape, or a quadrangular shape. The opening may be formed of one type of shape, or two or more types of shapes may be randomly arranged.

In the base material of the present invention, each opening area of the opening needs to be 5 mm ² or less. If the area of the opening exceeds 5 mm ² , the water permeability increases and a waterproof effect cannot be obtained, which is not preferable.
The base material may have a variation of ± 20% with respect to the center value in the case where the openings are composed of the same shape in principle, and further within a variation range of ± 10%. It is preferable to fit. Since each opening area is 5 mm ² or less including variations, when the maximum value of the opening area is 5 mm ² and the opening area has a variation of ± 20%, the central value ( Since 5 ÷ 1.2) ≈4.17 mm ² , the area range is 3.34 to ⁵ mm ² . Similarly, when the variation is ± 10%, the area range of the opening area is 4.55 to ⁵ mm ² .
Also when the opening part of the material of this invention is comprised from 2 or more types of different shapes, a preferable area range can be defined like the above.
As each opening area of the said opening part, a more preferable numerical range changes with uses. In the case of a screen door, a relatively large opening such as 2.5 to ⁵ mm ² is suitable with variation, but in the case of an umbrella or a wing, an opening that is somewhat small such as 0.1 to 3.5 mm ² Is suitable. In order not to allow fine water droplets such as mist and mist to pass through, it is preferable to make it smaller and 0.5 mm ² or less.

Further, the opening ratio R (%) represented by the following formula is 50% or less and preferably 33% or less with respect to the area U of the substrate. If the aperture ratio R (%) exceeds 50%, the water permeability becomes high, which is not preferable.

The opening has an area of a non-opening (peripheral non-opening) around the opening at least one time with respect to the opening having the maximum area. Preferably, it is formed so as to be twice or more. If the area of the peripheral non-opening is less than 1 times the opening area of the opening, the water permeability is increased, which is not preferable.
As shown in FIG. 4, the “peripheral non-opening portion” is a √2 on the extension line of a line connected from an arbitrary anchor point in the opening portion to the outer periphery of the opening portion with the shortest distance r. A region surrounded by the outer periphery of the peripheral non-opening that is a continuum of points at positions of xr or more. That is, in FIG. 4, when the anchor point of the opening is taken at the position of the mark ●, the extension of the line connected from the anchor point to the outer periphery of the opening (indicated by a single line in the figure) at the shortest distance r A region (peripheral non-opening portion (a), but opening portion) surrounded by the outer periphery of the peripheral non-opening portion (indicated by a single thick line in the figure), which is a continuum of points at a position of √2 × r on the line Is the smallest area of the peripheral non-opening. In FIG. 4, the distance between the anchor point indicated by the mark ● and the periphery of the peripheral non-opening portion is √2 × r. Here, representative three directions (r ₁ , r ₂ , r ₃ ) only.
Since the anchor point is an arbitrary point in the opening, for example, when the anchor point is taken at the position of ◎, the minimum area of the peripheral non-opening is indicated by a double line in the figure. A region surrounded by the outer periphery of the peripheral non-opening portion (peripheral non-opening portion (b), except for the region of the opening portion).
As long as the peripheral non-opening has a region having an area equal to or larger than the minimum region described above, the shape thereof is not particularly limited. For example, when the anchor point is located at the position of ◎, A random shape such as a region surrounded by the outer periphery of the peripheral non-opening portion indicated by a dotted line (excluding the region of the opening portion) may be used.

Hereinafter, in the non-permeable opening member of the present invention, the formation pattern of each opening when the substrate has a plurality of openings will be described with reference to the drawings.
FIG. 5 is a schematic diagram showing a case where a plurality of openings having the same area are irregularly formed on a substrate.
In FIG. 5, six openings 1 to 6 are formed on the base material so that the minimum areas of the respective peripheral non-openings do not overlap each other. As described above, the peripheral non-opening of each of the openings 1 to 6 can be determined by an arbitrary anchor point in each opening. Further, the openings 1 to 6 may be distributed in any way as long as the minimum regions of the respective peripheral non-openings are formed so as not to overlap each other. In FIG. 5, the sum of the areas of the openings 1 to 6 and the sum of the areas of the minimum regions of the respective peripheral non-openings is smaller than the area of the base material, and is represented by the above formula. The rate R (%) is 50% or less.
Moreover, in FIG. 5, the non-opening part (shaded part in a figure) other than the said peripheral non-opening part in the said base material further has the peripheral non-opening part of the said opening parts 1-6. A new opening 7 can be formed so as not to overlap each peripheral non-opening.

FIG. 6 is a schematic diagram showing a case where a plurality of openings having the same area are regularly formed on a substrate.
In FIG. 6, six openings 1 to 6 are formed on the base material such that the minimum areas of the respective peripheral non-openings do not overlap each other.
In FIG. 6, the sum of the areas of the openings 1 to 6 and the sum of the areas of the minimum regions of the respective peripheral non-openings is equal to the area of the base material, and is represented by the above formula. The rate R (%) is 50%.
In FIG. 6, if the area of each opening is reduced while maintaining the regular pattern, the aperture ratio R (%) is necessarily less than 50%.

In the water-impermeable opening member of the present invention, the plurality of openings on the substrate are preferably formed regularly as shown in FIG. 6, and specifically, formed in a mesh shape. It is preferable. In the case where the openings are quadrangular shapes having substantially the same size as in the mesh shape and are formed in a regular pattern, the opening ratio R represented by the above formula is the opening portion R. And the distance (wire diameter) between adjacent openings (opening ratio R = (opening diameter) ² / (opening diameter + wire diameter) ² ).

  There is no restriction | limiting in particular as a shape of the said base material, Although it can select suitably according to the objective, For example, plane shape, spherical shape (for example, earthenware etc.), cylindrical shape (for example, electric wire etc.), etc. are mentioned. be able to.

  The material for the substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acidic paper, neutral paper, coated paper, plastic film laminated paper, synthetic paper, plastic film (for example, Polyethylene terephthalate and polyethylene naphthalate), glass substrates, metal substrates (for example, aluminum), wooden substrates, ceramic substrates (for example, silicon wafers), nylon fibers, general polymer resins, etc. Can be mentioned.

The base material may be appropriately synthesized or a commercially available product may be used.
There is no restriction | limiting in particular as thickness of the material of the said base material, Although it can select suitably according to the objective, For example, 0.01-50 mm is preferable and 0.1-20 mm is more preferable. When the thickness is less than 0.01 mm, the base material is insufficient in fastness, so that the function may be deteriorated immediately. When the thickness exceeds 50 mm, it is difficult to mold and it is not practical.

  The base material of the present invention may contain a water repellent compound described later in the material, or formed on a water repellent material containing the water repellent compound on at least one surface of the material. You may have an aqueous layer. Examples of the material containing the water repellent compound include Teflon (registered trademark) resin.

-Water repellent compound-
The water repellent compound is not particularly limited as long as it has water repellency, and can be appropriately selected according to the purpose. For example, a fluorine-containing compound, a silicone compound, and the like can be preferably exemplified.

--Fluorine-containing compound--
The fluorine-containing compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a fluorine monomer, a polymer of the fluorine monomer, a copolymer of the fluorine monomer and another monomer, or A mixture thereof can be used.
The fluorine monomer is a monomer in which two or more fluorine atoms are contained in one molecule, and what is generally called a perfluoro compound is particularly preferable.

  Among the fluorine monomers, at least one selected from compounds represented by the following structural formulas (1), (2), (3), (4) and (5) is particularly preferable.

_{^{CH 2 = CR 1 COOR 2 Rf}} ··· structural formula (1)
However, in the structural formula (1), R ¹ represents a hydrogen atom or a methyl group.
R ² _{is, -C p H 2p -, -} C (C p H 2p + 1) H -, - CH 2 C (C p H 2p + 1) H-, or an _-CH 2 _CH 2 O-.
Rf _{is, -C n F 2n + 1,} - (CF 2) n H, -C n F 2n + 1 -CF 3, - (CF 2) p OC n H 2n C i F 2i + 1, - (CF 2) p OC m H _2m C _i F _{2i H,} represents a _{-N (C p H 2p + 1} ) COC n F 2n + 1, or _{-N (C p H 2p + 1} ) SO 2 C n F 2n + 1. However, in Rf, p represents 1 to 10, n represents 1 to 16, m represents 0 to 10, and i represents an integer of 0 to 16, respectively.

CF ₂ = CFORg ... Structural formula (2)
However, in said structural formula (2), Rg represents a C1-C20 fluoroalkyl group.

CH ₂ = CHRg ... Structural formula (3)
However, in said structural formula (3), Rg represents a C1-C20 fluoroalkyl group.

CH 2 = CR 3 COOR 5 R j R 6 OCOCR 4 = CH 2 ··· structural formula (4)
In the Structural Formula (4), R 3 and R 4 represents a hydrogen atom, or a methyl group.
R 5 and R 6, -C q H 2q -, - C (C q H 2q + 1) H -, - CH 2 C (C q H 2q + 1) H-, or an -CH 2 CH 2 O-.
R j represents -C t F 2t . However, in said R j, q is 1 to 10, t represents 1 to 16 integer, respectively.

^{_{CH 2 = CHR 7 COOCH 2 (}} CH 2 R k) CHOCOCR 8 = CH 2 ··· structural formula (5)
In the Structural Formula (5), ^{R 7} and ^{R 8} represents a hydrogen atom, or a methyl group.
R _k represents —C _y F _{2y + 1} . However, in said _{R k,} y is an integer of 1 to 16.

Specifically, as the compound represented by the structural formula (1), CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ OCOCH═CH ₂ , CF ₃ CH ₂ OCOCH═CH ₂ , CF ₃ (CF ₂ ) ₄ CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , C ₇ F ₁₅ CON (C ₂ H ₅ ) CH ₂ OCOC (CH ₃ ) ═CH ₂ , CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₂ ) CH ₂ CH ₂ OCOCH═CH ₂ , CF ₂ (CF ₂ ) ₇ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OCOCH═CH ₂ , C ₂ F ₅ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , (CF ₃ ) ₂ CF (CF ₂ ) ₆ (CH ₂ ) ₃ OCOCH═CH ₂ , (CF ₃ ) ₂ CF (CF ₂ ) ₁₀ (CH ₂ ) ₃ OCOC (CH _{3) CH 2, CF 3 (CF 2} ) 4 CH (CH 3) OCOC (CH 3) = CH 2, CF 3 CH 2 OCH 2 CH 2 OCOCH = CH 2, C 2 F 5 (CH 2 CH 2 O) 2 CH ₂ OCOCH═CH ₂ , (CF ₃ ) ₂ CFO (CH ₂ ) ₅ OCOCH═CH ₂ , CF ₃ (CF ₂ ) ₄ OCH ₂ CH ₂ OCOC (CH ₃ ) ═CH ₂ , C ₂ F ₅ CON (C ₂ H ₅ ) CH ₂ OCOCH═CH ₂ , CF ₃ (CF ₂ ) ₂ CON (CH ₃ ) CH (CH ₃ ), CH ₂ OCOCH═CH ₂ , H (CF ₂ ) ₆ C (C ₂ H ₅ ) OCOC ( _{CH 3) = CH 2, H} (CF 2) 8 CH 2 OCOCH = CH 2, H (CF 2) 4 CH 2 OCOCH = CH 2, H (CF 2) CH 2 OCOC (CH 3) = CH ₂ , CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) CH ₂ CH ₂ OCOC (CH ₃ ) ═CH ₂ , CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) (CH ₂ ) ₁₀ OCOCH = _{CH 2, C 2 F 5 SO} 2 N (C 2 H 5) CH 2 CH 2 OCOC (CH 3) = CH 2, CF 3 (CF 2) 7 SO 2 N (CH 3) (CH 2) 4 OCOCH = _{CH 2, C 2 F 5 SO} 2 N (C 2 H 5) C (C 2 H 5) HCH 2 OCOCH = CH 2, and the like. These may be used alone or in combination of two or more.

Specific examples of the compound represented by the structural formula (2) or (3), ie, the fluoroalkylated olefin, include C ₃ F ₇ CH═CH ₂ , C ₄ F ₉ CH═CH ₂ , and C _10. F ₂₁ CH═CH ₂ , C ₃ F ₇ OCF═CF ₂ , C ₇ F ₁₅ OCF═CF ₂ , C ₈ F ₁₇ OCF═CF ₂ , and the like can be given.

Examples of the compound represented by the structural formula (4) or (5), _{specifically, CH 2 = CHCOOCH 2 (CF} 2) 3 CH 2 OCOCH = CH 2, CH 2 = CHCOOCH 2 CH (CH 2 C ₈ F ₁₇ ) OCOCH═CH ₂ , and the like.

  As the fluorine-containing compound, a commercially available product may be used. Examples of the commercially available product include Asahi Guard (perfluoroalkyl ethyl acrylate) manufactured by Asahi Glass Co., Ltd. and Unidyne (perfluoroalkyl acrylate / n-alkyl acrylate copolymer).

There is no restriction | limiting in particular as said other monomer, Although it can select suitably according to the objective, A vinyl monomer is preferable. The vinyl monomer is, for example, at least one of a liquid or solid acrylate monomer and a methacrylic acid ester monomer from the viewpoint of curing speed (hereinafter, these may be referred to as “(meth) acrylate”). Is preferred.
Specific examples of the vinyl monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and 2-hydroxyethyl (meth). Acrylate, 2-hydroxypropyl (meth) acrylate, phenoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (Meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol di (meth) acrylate, polypro Glycols di (meth) acrylate, various types of epoxy (meth) acrylate, urethane (meth) acrylate, and the like. These may be used alone or in combination of two or more.
Furthermore, in addition to the vinyl monomer, styrene, α-methylstyrene, divinylbenzene N-vinylpyrrolidone, 2-vinylpyridine, olefinic hydrocarbon having 6 or more carbon atoms, and the like may be mixed.

--Silicone compound--
There is no restriction | limiting in particular as said silicone compound, According to the objective, it can select suitably, For example, a silicone oil, a silicone resin, etc. can be mentioned.
Specific examples of the silicone compound include surface treatment agents such as KP801M, X-24-9146, and KP18C manufactured by Shin-Etsu Chemical Co., Ltd., X-22 series (silicone graft acrylic resin), KPS series, KF series ( For example, silicone oil KF96); silicone acrylic emulsion manufactured by JSR; TSF series, TSW series, Tosbara, XS66-B0705 manufactured by GE Toshiba Silicone; oil SH series manufactured by Toray Dow Corning Silicone (for example, SH) -200 etc.), SF series; dry pon 600 manufactured by Nikka Chemical Co., Ltd., and the like.

Examples of the composite material of the fluorine-containing compound and the silicone compound include HIREC series manufactured by NTT-AT.
As another example of the water-repellent compound, for example, an uneven structure is formed in a self-organized manner during crystallization, such as an alkyl ketene dimer (Sakurai et al., Applied Physics, 64, 788 (1995)) to express super water repellency. And the like.

The water repellency of the water repellent compound can be evaluated by the contact angle of distilled water. Various methods for measuring the contact angle are known, but for the purpose of the present invention, a stationary measurement method is preferable, and a method of observing the shape of a water droplet and calculating an angle by Laplace-Young approximation is preferable. Specifically, a method of measuring the contact angle of distilled water with respect to the coated surface of the glass substrate on which the water repellent compound is coated is preferable. The contact angle of the water repellent compound used in the present invention is preferably 120 ° or more, and more preferably 135 ° or more.
In addition, the contact angle between the water-impermeable opening member of the present invention and distilled water is not measured in principle because the size of the water droplet and the area of the opening do not match, that is, the water droplet diameter is several times larger than the opening diameter. Although it is possible, the contact angle with respect to the part which has a several opening part can be measured for convenience. Such a contact angle is preferably 100 ° or more, and more preferably 120 ° or more.

<Water repellent layer>
The water repellent layer is formed from a water repellent material. The water repellent material includes at least a water repellent compound, preferably includes a photocatalyst, and further includes a binder resin and, if necessary, other components.
As the water repellent compound, the same water repellent compound as described above can be used.
The binder resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, polyvinyl alcohol resin, gelatin, vinyl chloride / vinyl acetate copolymer; vinyl chloride; Copolymers with at least one of vinyl alcohol, maleic acid and acrylic acid; vinyl chloride / vinylidene chloride copolymer; vinyl chloride / acrylonylyl copolymer; ethylene / vinyl acetate copolymer; cellulose derivatives such as nitrocellulose resin; Polyacrylic resin, polyvinyl acetal resin, polyvinyl butyral resin, epoxy resin, phenoxy resin, polyurethane resin, polycarbonate resin, novolac resin, soluble nylon, polystyrene resin, melamine resin, formalin resin, etc. These may be used alone or in combination of two or more.
The binder resin may be used after adding a known hemiacetal-based or isocyanate-based crosslinking agent and performing a curing treatment.

-Photocatalyst-
As the photocatalyst used in the present invention, all existing products and commercially available products can be used, and a powder or sol state is preferable. In the case of the powder, it is preferably used in the form of a granulated body, an adsorbed product on activated carbon / inorganic fibers, a coating liquid in a dispersed state, and the like. On the other hand, in the sol state, it is preferably used in the form of a coating liquid.

As a main component of the photocatalyst, titanium oxide (TiO ₂ ) is preferable. Here, the “main component” means a component containing 50% by mass or more based on the total solid content of the photocatalyst.
The crystal form of the titanium oxide powder is preferably anatase or rutile. This crystal form may be a single form or a mixture.
Specific examples of the titanium oxide powder include ST series such as ST-01 manufactured by Ishihara Sangyo Co., Ltd .; Blue Active PW-25 manufactured by Ecodevice; SSP Series, STR Series, CS Series manufactured by Sakai Chemical; Chronos (KA series, KR series); TiONA manufactured by Millennium Chemicals; P-25 catalyst manufactured by Degussa, and the like.
The photocatalyst may be a mixture of a plurality of components including the titanium oxide. Specifically, the SX-T series (SX type means a binary composite oxide of titanium and silica) manufactured by Nippon Shokubai, etc. Can be mentioned.

  As content in the water repellent material of the said photocatalyst, 10 mass% or less is preferable at solid content concentration, and 0.1-5 mass% is preferable. If the content exceeds 10% by mass, the photocatalytic activity increases, but the durability of the water-repellent material decreases, so the contact angle with water may decrease in a short time.

-Method for forming water repellent layer-
The water repellent layer can be applied by applying and drying the water repellent material on the substrate. There is no restriction | limiting in particular as a coating method of this water repellent material, Although it can select suitably, For example, the coating method, the spray method, the immersion fixation processing method, etc. can be mentioned. These may be used individually by 1 type, and may combine 2 or more types by the shape, material, etc. of a base material.
There is no restriction | limiting in particular as thickness of the said water repellent layer, Although it can select suitably according to the objective, For example, 0.1-100 micrometers is preferable and 0.5-50 micrometers is more preferable. If the thickness is less than 0.1 μm, the fastness of the water-repellent layer is insufficient, so that the function may be deteriorated immediately. If the thickness exceeds 100 μm, film formation is difficult and impractical.

  Since the water-impermeable opening member of the present invention has both air permeability and waterproofness, for example, waterproof bags, goggles, umbrellas, shoes, bags, gloves, sports equipment for mobile devices such as mobile phones and digital cameras. It can be widely applied to screen doors, package members, agricultural sheets and the like.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
-Production of water-impermeable opening member-
Nylon filtration cloth No. 1 shown in Table 2. 1 (trade name: N-110, Noguchi Sieve cloth, 110 mesh, aperture ratio: 49%) was spray coated with HIREC1100 (manufactured by NTT Advanced Technology Co., Ltd.), a super water-repellent spray, on the surface of the filtration cloth A super water-repellent film was formed to produce a water-impermeable opening member. The spray coating was performed on the front surface of the filter cloth for a total of 3 sets, with one set of spraying and subsequent room temperature drying treatment for 30 minutes. In addition, when this water-impermeable opening member was observed with the electron microscope and the area of the opening part which has the largest aperture and the area of the non-opening part in the peripheral part were calculated | required, it has confirmed that it was 1 time or more.
Using the obtained non-permeable opening member of Example 1, the permeability of water and the permeability of an aqueous solution having a lower surface tension than water were evaluated by the following methods. The results are shown in Table 3.

<Evaluation of permeability>
(1) Water permeability The obtained water-impermeable opening member was cut into a square shape having a side of 10 cm and used as a test piece, and the water permeability was evaluated. As shown in FIG. 7, when 20 mL of distilled water was put into a 100 mL cup, the mouth of the cup was covered with each test piece, and the top of the cup was returned, immediately after the start of the test, 3 days after the start of the test, and 10 days after the start of the test Permeability was evaluated from the amount of distilled water that permeated the test piece and dropped below. Evaluation criteria are as shown in Table 1. The results are shown in Table 3.

(2) Permeability of aqueous solution having lower surface tension than water (1) In the evaluation of water permeability, 0.1% by mass of sodium dodecyl sulfate (SDS), which is an aqueous solution having a lower surface tension than water, is used. The permeability of an aqueous solution having a surface tension lower than that of water was evaluated in the same manner as the evaluation of water permeability except that the aqueous solution was used. The results are shown in Table 3.

(Example 2)
In Example 1, nylon filter cloth No. 1 is a nylon filtration cloth No. 1 described in Table 2. 2 (product name: N-150, made by Noguchi sieve cloth, 150 mesh, aperture ratio: 41%) The permeability of an aqueous solution having a surface tension lower than that of water was evaluated. The results are shown in Table 3.

(Example 3)
In Example 1, nylon filter cloth No. 1 is a nylon filtration cloth No. 1 described in Table 2. 3 (product name: N-250, made by Noguchi sieve cloth, 250 mesh, aperture ratio: 33%) was used in the same manner as in Example 1 except that the water-impermeable opening member of Example 3 was prepared. The permeability of an aqueous solution having a surface tension lower than that of water was evaluated. The results are shown in Table 3.

Example 4
In Example 1, nylon filter cloth No. 1 is a nylon filtration cloth No. 1 described in Table 2. 4 (product name: N-420, made by Noguchi sieve cloth, 420 mesh, opening ratio: 31%), except that the water-impermeable opening member of Example 4 was prepared in the same manner as in Example 1 to obtain water. The permeability of an aqueous solution having a surface tension lower than that of water was evaluated. The results are shown in Table 3.

(Examples 5 to 8)
In Examples 1-4, the water-impermeable openings of Examples 5-8 were the same as in Examples 1-4 except that the super water-repellent spray was changed from HIREC 1100 to HIREC 1550 (manufactured by NTT Advanced Technology Corporation). Members were prepared, and the water permeability and the permeability of an aqueous solution having a lower surface tension than water were evaluated. The results are shown in Table 3.
In Examples 7 and 8, 3 μL of water was dropped onto the obtained water-impermeable opening member, and the contact angle of the water-impermeable opening member with respect to water was determined by a contact angle measuring device (OCA20 manufactured by Eihiro Seiki Co., Ltd.). ) And 138 ° and 148 °, respectively. Further, as an aqueous solution having a surface tension lower than that of water, a 0.1% by mass SDS aqueous solution was similarly dropped by 3 μL, and the contact angles with respect to the aqueous solution having a surface tension lower than that of water were measured. °.
Moreover, when HIREC1550 was apply | coated on the glass base material and the contact angle of water was measured, it was 155 degrees.
Moreover, the observation photograph of the water droplet shape on the water-impermeable opening member of Example 8 is shown in FIG.

(Comparative Examples 1-4)
As Comparative Examples 1 to 4, an untreated nylon filtration cloth No. 1 was used. 1-No. 4 and in the same manner as in Example 1, the nylon filter cloth No. 1-No. The permeability of water No. 4 and the permeability of an aqueous solution having a lower surface tension than water were evaluated. The results are shown in Table 3.
In Comparative Example 4, the contact angles of the obtained water-impermeable opening member with water and the 0.1 mass% SDS aqueous solution were measured in the same manner as in Examples 7 and 8, and 111 ° and 79 respectively. °.

* 1: Opening area = (opening diameter) ²
* 2: Opening ratio = (opening diameter) ² / (opening diameter + wire diameter) ²

From the results of Table 3, the non-water-permeable opening members of Examples 1 to 8 having an opening ratio R (%) represented by the above formula of 50% or less and exhibiting water repellency have a water-repellent layer. It turned out that it is hard to permeate | transmit water or it does not permeate | transmit water with respect to the opening member of Comparative Examples 1-4 which is not. Among these, it was found that the water-impermeable opening members of Examples 5 to 8 having a water-repellent layer formed of a water-repellent material imparting high water repellency are particularly difficult to transmit water.
Furthermore, the non-permeable opening members of Examples 7 to 8 having an opening ratio R (%) of 33% or less do not transmit water, and in addition, an aqueous solution having a surface tension smaller than that of water is extremely difficult to transmit. I understood. It can be said that the waterproof property in real life is high that it has poor permeability to an aqueous solution containing foreign substances, that is, an aqueous solution having a surface energy smaller than that of water.

  Since the water-impermeable opening member of the present invention has both air permeability and waterproofness, for example, waterproof bags, goggles, umbrellas, shoes, bags, gloves, sports equipment for mobile devices such as mobile phones and digital cameras. It can be widely applied to screen doors, package members, agricultural sheets and the like.

FIG. 1 is a schematic diagram illustrating the principle of measuring the contact angle of water. FIG. 2 is a schematic diagram showing a substrate having a square opening. FIG. 3 is a schematic diagram showing a substrate having a circular opening. FIG. 4 is an explanatory diagram showing the definition of the peripheral non-opening. FIG. 5 is a schematic diagram showing a base material in which a plurality of openings are irregularly formed. FIG. 6 is a schematic diagram showing a base material in which a plurality of openings are regularly formed. FIG. 7 is a schematic diagram showing a method for evaluating water permeability in Examples. FIG. 8 is an observation photograph of a water droplet shape on the water-impermeable opening member of Example 8.

Claims (8)

The substrate is provided with a plurality of through holes,
Each opening area of the opening in which the through hole is formed is 5 mm ² or less,
An impermeable opening member characterized by having an opening ratio R (%) represented by the following formula of 50% or less with respect to the area U of the base material and exhibiting water repellency.
  The water impermeable opening member according to claim 1, wherein the opening ratio R (%) is 33% or less.   3. The water-impermeable opening member according to claim 1, wherein the area of the non-opening portion around the opening is one or more times that of the opening having the maximum area.   The water impermeable opening member according to any one of claims 1 to 3, wherein the opening is formed in a mesh shape.   The water impermeable opening member according to any one of claims 1 to 4, wherein the base material contains a water repellent compound.   The water impermeable opening member according to any one of claims 1 to 5, further comprising a water repellent layer formed of a water repellent material containing a water repellent compound on at least one surface of the substrate.   The water-impermeable opening member according to claim 6, wherein the water-repellent material includes a photocatalyst mainly composed of titanium oxide having a solid content concentration of 10% by mass or less. The water impermeable opening member according to any one of claims 1 to 7, wherein a contact angle with water is 100 ° or more.