JP2009271298A - Antifogging transparent member and article equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antifogging transparent member excellent in an antifogging nature and an article equipped with the same. <P>SOLUTION: The antifogging transparent member 10 has fine rugged structure on its surface and the fine rugged structure is formed by transferring the fine rugged structure on a surface of anodically oxidized alumina. Further the article equipped with the antifogging transparent member 10 is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antifogging transparent member and an article provided with the same.

Articles such as helmet shields, various windows, and various spectacles are required to have anti-fogging properties because the visibility decreases when clouded. As methods for imparting antifogging properties to such articles, for example, the following are disclosed.
After the top layer of the antireflection film provided on the substrate is formed by vacuum deposition, the top layer is treated with a hydrophilic substance to prevent the hydrophilic substance from being fixed to the pores and fine irregularities of the top layer. A method for producing a cloudy article (Patent Document 1).

However, the antifogging article obtained by the method described above is not always sufficient in antifogging property.
Therefore, it is calculated | required that the more outstanding anti-fog property is provided.
Japanese Patent No. 3694881

  The present invention provides an antifogging transparent member excellent in antifogging property and an article provided with the same.

The antifogging transparent member of the present invention is an antifogging transparent member having a fine concavo-convex structure on the surface, and the fine concavo-convex structure is formed by transferring the fine concavo-convex structure on the surface of anodized alumina. It is characterized by being. The anodized alumina is useful in that it has a large area and can form a fine concavo-convex structure on both a flat surface and a curved surface.
The article of the present invention is characterized by comprising the antifogging transparent member of the present invention.

Since the antifogging transparent member of the present invention exhibits hydrophobicity or hydrophilicity, it is excellent in antifogging properties.
Since the article of the present invention is excellent in anti-fogging property, the visibility is good.

  In this specification, (meth) acrylate means an acrylate or a methacrylate. Moreover, an active energy ray means visible light, an ultraviolet-ray, an electron beam, plasma, a heat ray (infrared rays etc.), etc.

<Anti-fogging transparent member>
FIG. 1 is a cross-sectional view showing an example of the antifogging transparent member of the present invention. The antifogging transparent member 10 includes a base body 12 and an antifogging film 16 having a fine concavo-convex structure (not shown) attached to the base body 12 via an adhesive layer 14.

(Base material body)
The substrate body 12 is a substrate that can transmit light. Examples of the material of the base body 12 include glass, acrylic resin, polycarbonate, styrene resin, polyester, cellulose resin (such as triacetyl cellulose), polyolefin, and alicyclic polyolefin.

(Adhesive layer)
Examples of the adhesive of the adhesive layer 14 include a double-sided adhesive tape.

(Anti-fog film)
The antifogging film 16 has a film body 18 and a cured resin film 20 having a fine uneven structure (not shown) formed on the surface of the film body 18.
The film body 18 is a film that can transmit light. Examples of the material of the film body 18 include acrylic resins, polycarbonates, styrene resins, polyesters, cellulose resins (such as triacetyl cellulose), polyolefins, and alicyclic polyolefins.

The cured resin film 20 is a film made of a cured product of an active energy ray-curable resin composition described later, and has a fine uneven structure on the surface.
The fine concavo-convex structure has a plurality of convex portions made of a cured product of the active energy ray-curable resin composition, and is formed by transferring the fine concavo-convex structure on the surface of the anodized alumina.

  As the fine concavo-convex structure, a so-called moth-eye structure in which a plurality of protrusions (convex portions) having a substantially conical shape or a pyramid shape are arranged is preferable. Since the cured resin film 20 has a fine uneven structure on the surface, an antifogging transparent member having excellent antifogging properties can be obtained. In particular, the moth-eye structure in which the distance between the protrusions is less than or equal to the wavelength of visible light can be an effective antireflection means by continuously increasing the refractive index from the refractive index of air to the refractive index of the material. Are known.

  The average interval between the convex portions is preferably 600 nm or less, and more preferably 500 nm or less. If the average interval between the convex portions is 600 nm or less, the antifogging property can be sufficiently exhibited. In particular, when the average interval between the convex portions is not more than the wavelength of visible light, that is, not more than 400 nm, an antifogging transparent member having low reflectance and low reflectance wavelength dependency is obtained.

The average distance between the convex portions is preferably 25 nm or more, and more preferably 80 nm or more from the viewpoint of easy formation of the convex portions.
The average interval between the convex portions is obtained by measuring 50 intervals between adjacent convex portions (distance from the center of the convex portion to the center of the adjacent convex portion) by electron microscope observation, and averaging these values. .

100-400 nm is preferable and, as for the height of a convex part, 150-300 nm is more preferable. If the height of the convex portion is 100 nm or more, not only is the antifogging property excellent, but the reflectance is sufficiently low, and the wavelength dependency of the reflectance is small. If the height of the convex portion is 400 nm or less, the scratch resistance of the convex portion is good.
The height of the convex portion is obtained by measuring the height of 50 convex portions by electron microscope observation and averaging these values.

  The aspect ratio of the convex portion (height of the convex portion / average interval between the convex portions) is preferably 1.0 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3.0. Particularly preferred. If the aspect ratio of the convex portion is 1.0 or more, not only is the antifogging property excellent, but the reflectance is sufficiently low. If the aspect ratio of the convex portion is 5.0 or less, the scratch resistance of the convex portion is good.

  The shape of the convex part is a shape in which the convex sectional area in the direction perpendicular to the height direction continuously increases in the depth direction from the outermost surface, that is, the sectional shape in the height direction of the convex part is a triangle, trapezoid, A shape such as a bell shape is preferred.

  The difference between the refractive index of the cured resin film 20 and the refractive index of the film body 18 is preferably 0.2 or less, more preferably 0.1 or less, and particularly preferably 0.05 or less. When the refractive index difference is 0.2 or less, reflection at the interface between the cured resin film 20 and the film body 18 is suppressed.

  When the surface has a fine concavo-convex structure, if the surface is formed from a hydrophobic material, super water repellency can be obtained by the Lotus effect, and if the surface is formed from a hydrophilic material, super hydrophilicity can be obtained. It has been known.

  When the material of the cured resin film 20 is hydrophobic, the water contact angle on the surface of the fine concavo-convex structure is preferably 90 ° or more, more preferably 100 ° or more, and particularly preferably 110 ° or more. If the water contact angle is 90 ° or more, water droplets are difficult to adhere, so that sufficient antifogging properties are exhibited. In addition, if the material is hydrophobic, it is difficult for water droplets to adhere to it, so that antifouling properties and anti-icing properties can also be exhibited.

  When the material of the cured resin film 20 is hydrophilic, the water contact angle on the surface of the fine concavo-convex structure is preferably 25 ° or less, more preferably 23 ° or less, and particularly preferably 21 ° or less. When the water contact angle is 25 ° or less, the antifogging property is excellent, and the dirt attached to the surface is washed away with water, and the oily dirt is less likely to adhere, so that the antifouling property can be exhibited.

<Method for producing anti-fogging transparent member>
The antifogging transparent member 10 is manufactured by sticking the base body 12 and the antifogging film 16 through the adhesive layer 14.

The antifogging film 16 is manufactured as follows, for example, using the manufacturing apparatus shown in FIG.
The active energy ray-curable resin composition is transferred from the tank 24 between the roll-shaped mold 22 having a fine concavo-convex structure (not shown) on the surface and the strip-shaped film body 18 that moves along the surface of the roll-shaped mold 22. Supply.

  The film main body 18 and the active energy ray curable resin composition are nipped between the roll-shaped mold 22 and the nip roll 28 whose nip pressure is adjusted by the pneumatic cylinder 26, and the active energy ray curable resin composition is removed from the film. While being uniformly distributed between the main body 18 and the roll-shaped mold 22, it is filled in the concave portions of the fine concavo-convex structure of the roll-shaped mold 22.

The active energy ray curable resin composition is irradiated with the active energy ray curable resin composition through the film body 18 from the active energy ray irradiating device 30 installed below the roll-shaped mold 22 to cure the active energy ray curable resin composition. Thus, the cured resin film 20 to which the fine uneven structure on the surface of the roll mold 22 is transferred is formed.
The antifogging film 16 is obtained by peeling the film body 18 having the cured resin film 20 formed on the surface by the peeling roll 32.

The active energy ray irradiation device 30 is preferably a high-pressure mercury lamp, a metal halide lamp, or the like. In this case, the amount of light irradiation energy is preferably 100 to 10,000 mJ / cm ² .

(Roll mold)
The roll-shaped mold 22 is a mold having anodized alumina on the surface. A mold having an anodized alumina on the surface can increase the area, and a roll mold can be easily produced.

  Anodized alumina is a porous oxide film (alumite) of aluminum and has a plurality of pores (concave portions) on the surface.

A mold having an anodized alumina on the surface can be produced, for example, through the following steps (a) to (e).
(A) A step of forming an oxide film by anodizing roll-shaped aluminum in an electrolytic solution under a constant voltage.
(B) A step of removing the oxide film and forming pore generation points for anodic oxidation.
(C) A step of anodizing the roll-shaped aluminum again in the electrolytic solution to form an oxide film having pores at the pore generation points.
(D) A step of enlarging the diameter of the pores.
(E) A step of repeatedly performing the steps (c) and (d).

(A) Process:
As shown in FIG. 3, when the aluminum 34 is anodized, an oxide film 38 having pores 36 is formed.
The purity of aluminum is preferably 99% or more, more preferably 99.5% or more, and particularly preferably 99.8% or more. When the purity of aluminum is low, when anodized, an uneven structure having a size to scatter visible light may be formed due to segregation of impurities, or the regularity of pores obtained by anodization may be lowered.
Examples of the electrolytic solution include sulfuric acid, oxalic acid, and phosphoric acid.

When using oxalic acid as electrolyte:
The concentration of oxalic acid is preferably 0.7 M or less. When the concentration of oxalic acid exceeds 0.7M, the current value becomes too high, and the surface of the oxide film may become rough.
When the formation voltage is 30 to 60 V, anodized alumina having highly regular pores with a period of 100 nm can be obtained. Regardless of whether the formation voltage is higher or lower than this range, the regularity tends to decrease.
The temperature of the electrolytic solution is preferably 60 ° C. or lower, and more preferably 45 ° C. or lower. When the temperature of the electrolytic solution exceeds 60 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken, or the surface may melt and the regularity of the pores may be disturbed.

When using sulfuric acid as the electrolyte:
The concentration of sulfuric acid is preferably 0.7M or less. If the concentration of sulfuric acid exceeds 0.7M, the current value may become too high to maintain a constant voltage.
When the formation voltage is 25 to 30 V, anodized alumina having highly regular pores with a period of 63 nm can be obtained. The regularity tends to decrease whether the formation voltage is higher or lower than this range.
The temperature of the electrolytic solution is preferably 30 ° C. or lower, and more preferably 20 ° C. or lower. When the temperature of the electrolytic solution exceeds 30 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken or the surface may melt and the regularity of the pores may be disturbed.

(B) Process:
As shown in FIG. 3, the regularity of the pores can be improved by once removing the oxide film 38 and using it as the pore generation point 40 for anodic oxidation.

  Examples of the method for removing the oxide film include a method in which aluminum is not dissolved but is dissolved in a solution that selectively dissolves the oxide film and removed. Examples of such a solution include a chromic acid / phosphoric acid mixed solution.

(C) Process:
As shown in FIG. 3, when the aluminum 34 from which the oxide film has been removed is anodized again, an oxide film 38 having cylindrical pores 36 is formed.
Anodization may be performed under the same conditions as in step (a). Deeper pores can be obtained as the anodic oxidation time is lengthened.

(D) Process:
As shown in FIG. 3, a process of expanding the diameter of the pores 36 (hereinafter referred to as a pore diameter expansion process) is performed. The pore diameter expansion treatment is a treatment for expanding the diameter of the pores obtained by anodic oxidation by immersing in a solution dissolving the oxide film. Examples of such a solution include a phosphoric acid aqueous solution of about 5% by mass.
The longer the pore diameter expansion processing time, the larger the pore diameter.

(E) Process:
As shown in FIG. 3, when the anodic oxidation in the step (c) and the pore diameter expansion process in the step (d) are repeated, the pores 36 have a shape in which the diameter continuously decreases in the depth direction from the opening. An anodized alumina is formed, and a mold (roll mold 22) having an anodized alumina on the surface is obtained.
The total number of repetitions is preferably 3 times or more, and more preferably 5 times or more. When the number of repetitions is 2 times or less, the diameter of the pores decreases discontinuously. Therefore, the effect of reducing the reflectance of the cured resin film 20 produced using anodized alumina having such pores is insufficient. is there.

  The surface of the anodized alumina may be treated with a release agent so that separation from the cured resin film 20 is easy. Examples of the treatment method include a method of coating a silicone resin or a fluorine-containing polymer, a method of depositing a fluorine-containing compound, a method of coating a fluorine-containing silane coupling agent or a fluorine-containing silicone-based silane coupling agent, and the like.

Examples of the shape of the pore 36 include a substantially conical shape, a pyramid shape, a cylindrical shape, and the like, and a cross-sectional area of the pore in a direction perpendicular to the depth direction, such as a cone shape and a pyramid shape, is a depth from the outermost surface. A shape that continuously decreases in the direction is preferred.
The average interval between the pores 36 is preferably 600 nm or less, and more preferably 500 nm or less.

The depth of the pores 36 is preferably 100 to 400 nm, and more preferably 150 to 300 nm.
The aspect ratio of the pores 36 (depth of pores / average interval between pores) is preferably 1.0 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3.0. Is particularly preferred.
The surface of the cured resin film 20 formed by transferring the pores 36 as shown in FIG. 3 has a so-called moth-eye structure.
Thus, the antifogging transparent member of the present invention has a fine concavo-convex structure formed by transferring the fine concavo-convex structure on the surface of anodized alumina on the surface thereof.

(Active energy ray-curable resin composition)
In order for the antifogging transparent member having a fine concavo-convex structure on the surface to exhibit hydrophobicity or hydrophilicity, for example, a composition capable of forming a hydrophobic material or a hydrophilic material is used as an active energy ray-curable resin composition. That's fine.

(Composition capable of forming a hydrophobic material)
In order to set the water contact angle of the surface of the fine uneven structure of the cured resin film 20 to 90 ° or more, the active energy ray-curable resin composition capable of forming a hydrophobic material includes a fluorine-containing compound or a silicone compound. It is preferable to use a composition.

Fluorine-containing compounds:
As the fluorine-containing compound, a compound having a fluoroalkyl group represented by the following formula (1) is preferable.
_{- (CF 2) n -X ···} (1).
However, X represents a fluorine atom or a hydrogen atom, n represents an integer greater than or equal to 1, 1-20 are preferable, 3-10 are more preferable, and 4-8 are especially preferable.

  Examples of the fluorine-containing compound include a fluorine-containing monomer, a fluorine-containing silane coupling agent, a fluorine-containing surfactant, and a fluorine-containing polymer.

Examples of the fluorine-containing monomer include a fluoroalkyl group-substituted vinyl monomer and a fluoroalkyl group-substituted ring-opening polymerizable monomer.
Examples of the fluoroalkyl group-substituted vinyl monomer include fluoroalkyl group-substituted (meth) acrylates, fluoroalkyl group-substituted (meth) acrylamides, fluoroalkyl group-substituted vinyl ethers, and fluoroalkyl group-substituted styrenes.

  Examples of the fluoroalkyl group-substituted ring-opening polymerizable monomer include fluoroalkyl group-substituted epoxy compounds, fluoroalkyl group-substituted oxetane compounds, and fluoroalkyl group-substituted oxazoline compounds.

As the fluorine-containing monomer, a fluoroalkyl group-substituted (meth) acrylate is preferable, and a compound of the following formula (2) is particularly preferable.
^{_{CH 2 = C (R 21)}} C (O) O- (CH 2) m - (CF 2) n -X ··· (2).
However, R < ²¹ > represents a hydrogen atom or a methyl group, X represents a hydrogen atom or a fluorine atom, m represents the integer of 1-6, 1-3 are preferable, 1 or 2 is more preferable, n Represents an integer of 1 to 20, preferably 3 to 10, and more preferably 4 to 8.

As the fluorine-containing silane coupling agent, a fluoroalkyl group-substituted silane coupling agent is preferable, and a compound of the following formula (3) is particularly preferable.
(R ^f ) _a R ³¹ _b SiY _c (3).

R ^f represents a C1-C20 fluorine-substituted alkyl group which may contain one or more ether bonds or ester bonds. Examples of R ^f include 3,3,3-trifluoropropyl group, tridecafluoro-1,1,2,2-tetrahydrooctyl group, 3-trifluoromethoxypropyl group, and 3-trifluoroacetoxypropyl group. It is done.

R ³¹ represents an alkyl group having 1 to 10 carbon atoms. Examples of R ³¹ include a methyl group, an ethyl group, and a cyclohexyl group.

Y represents a hydroxyl group or a hydrolyzable group.
Examples of the hydrolyzable group include an alkoxy group, a halogen atom, R ³² C (O) O (wherein R ³² represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms) and the like.
Examples of the alkoxy group include methoxy group, ethoxy group, propyloxy group, i-propyloxy group, butoxy group, i-butoxy group, t-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group, Examples include octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group, lauryloxy group, and the like.
Examples of the halogen atom include Cl, Br, I and the like.
Examples of R ³² C (O) O include CH ₃ C (O) O, C ₂ H ₅ C (O) O, and the like.

  a, b, and c are integers satisfying a + b + c = 4 and satisfying a ≧ 1, c ≧ 1, and preferably a = 1, b = 0, and c = 3.

  Fluorine-containing silane coupling agents include 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriacetoxysilane, dimethyl-3,3,3-trifluoropropylmethoxysilane, Examples include decafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane.

  Examples of the fluorine-containing surfactant include a fluoroalkyl group-containing anionic surfactant and a fluoroalkyl group-containing cationic surfactant.

Examples of the fluoroalkyl group-containing anionic surfactant include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C ₆ -C ₁₁ ) oxy. ] -1-alkyl _(C 3 _{~C 4)} sulfonate, sodium 3- [omega - fluoroalkanoyl _{(C 6 ~C} 8) -N- ethylamino] -1-sodium sulfonic acid, fluoroalkyl _{(C 11} ~ C ₂₀ ) carboxylic acid or a metal salt thereof, perfluoroalkyl carboxylic acid (C _{7 to} C ₁₃ ) or a metal salt thereof, perfluoroalkyl (C _{4 to} C ₁₂ ) sulfonic acid or a metal salt thereof, perfluorooctane sulfonic acid diethanolamine N-propyl-N- (2-hydroxy Chill) perfluorooctane sulfonamide, perfluoroalkyl _(C 6 _{-C 10)} sulfonamide propyl trimethyl ammonium salts, perfluoroalkyl _{(C 6} -C 10)-N-ethylsulfonyl glycine salts, monoperfluoroalkyl _{(C 6} -C ₁₆₎ ethyl phosphoric acid ester, and the like.

Examples of the fluoroalkyl group-containing cationic surfactant include aliphatic quaternary compounds such as fluoroalkyl group-containing aliphatic primary, secondary or tertiary amine acids, and perfluoroalkyl (C ₆ -C ₁₀ ) sulfonamidopropyltrimethylammonium salts. Examples thereof include ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like.

  Fluorine-containing polymers include polymers of fluoroalkyl group-containing monomers, copolymers of fluoroalkyl group-containing monomers and poly (oxyalkylene) group-containing monomers, and copolymers of fluoroalkyl group-containing monomers and crosslinking reactive group-containing monomers. A polymer etc. are mentioned. The fluorine-containing polymer may be a copolymer with another copolymerizable monomer.

As the fluorine-containing polymer, a copolymer of a fluoroalkyl group-containing monomer and a poly (oxyalkylene) group-containing monomer is preferable.
As the poly (oxyalkylene) group, a group represented by the following formula (4) is preferable.
_{^{- (OR 41) p - ···}} (4).
^{However, R 41} represents an alkylene group having 2 to 4 carbon atoms, p is an integer of 2 or more. Examples of R ⁴¹ include —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, and the like.

The poly (oxyalkylene) group may be composed of the same oxyalkylene unit (OR ⁴¹ ), or may be composed of two or more oxyalkylene units (OR ⁴¹ ). The arrangement of two or more oxyalkylene units (OR ⁴¹ ) may be a block or random.

Silicone compounds:
Examples of the silicone compound include (meth) acrylic acid-modified silicone, silicone resin, silicone silane coupling agent and the like.
Examples of the (meth) acrylic acid-modified silicone include silicone (di) (meth) acrylates such as X-22-1602 (manufactured by Shin-Etsu Chemical Co., Ltd.).

(Composition capable of forming a hydrophilic material)
In order to set the water contact angle on the surface of the fine uneven structure of the cured resin film 20 to 25 ° or less, an active energy ray-curable resin composition capable of forming a hydrophilic material is a composition containing at least a hydrophilic monomer. It is preferable to use it. Moreover, it is more preferable to contain a cross-linkable polyfunctional monomer from the viewpoint of scratch resistance and imparting water resistance. In addition, the same (namely, hydrophilic polyfunctional monomer) may be sufficient as the polyfunctional monomer which can be bridge | crosslinked with a hydrophilic monomer. Furthermore, the active energy ray-curable resin composition may contain other monomers. Moreover, it is more preferable to use the composition containing the following polymeric compound.
10 to 50% by mass of a tetrafunctional or higher polyfunctional (meth) acrylate,
30-80% by weight of bifunctional or higher hydrophilic (meth) acrylate,
A polymerizable compound comprising a total of 100% by mass of 0 to 20% by mass of a monofunctional monomer.

As tetrafunctional or higher polyfunctional (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, succinic acid / trimethylolethane / acrylic acid molar mixture 1: 2: 4 condensation reaction mixture, urethane acrylates (manufactured by Daicel-Cytec: EBECRYL220, EBECRYL1290K, EBECRYL1290K, EBECRYL5129, EBECRYL8210, EBECRYL 8301, KRM 8200), polyether acrylates (manufactured by Daicel-Cytec: EBEC) YL81), modified epoxy acrylates (manufactured by Daicel-Cytec: EBECRYL3416), polyester acrylates (manufactured by Daicel-Cytech: EBECRYL450, EBECRYL657, EBECRYL800, EBECRYL810, EBECRYL8111, EBECRYL81L, EBECRYL81L It is done. These may be used alone or in combination of two or more.
The polyfunctional (meth) acrylate having 4 or more functional groups is more preferably a polyfunctional (meth) acrylate having 5 or more functional groups.

  The proportion of the tetrafunctional or higher polyfunctional (meth) acrylate is preferably 10 to 50% by mass, more preferably 20 to 50% by mass, and particularly preferably 30 to 50% by mass from the viewpoint of water resistance and chemical resistance. If the ratio of the tetrafunctional or higher polyfunctional (meth) acrylate is 10% by mass or more, the elastic modulus is increased and the scratch resistance is improved. If the ratio of the tetrafunctional or higher polyfunctional (meth) acrylate is 50% by mass or less, small cracks are hardly formed on the surface, and the appearance is hardly deteriorated.

Long-chain polyethylene such as Aronix M-240, Aronix M260 (manufactured by Toagosei Co., Ltd.), NK ester AT-20E, NK ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Examples thereof include polyfunctional acrylates having glycol and polyethylene glycol dimethacrylate. These may be used alone or in combination of two or more.
In the polyethylene glycol dimethacrylate, the total of the average repeating units of the polyethylene glycol chain present in one molecule is preferably 6 to 40, more preferably 9 to 30, and particularly preferably 12 to 20. If the average repeating unit of the polyethylene glycol chain is 6 or more, the hydrophilicity is sufficient and the antifouling property is improved. When the average repeating unit of the polyethylene glycol chain is 40 or less, the compatibility with a polyfunctional (meth) acrylate having 4 or more functionalities is improved, and the active energy ray-curable resin composition is hardly separated.

  30-80 mass% is preferable and, as for the ratio of bifunctional or more hydrophilic (meth) acrylate, 40-70 mass% is more preferable. When the ratio of the bifunctional or higher hydrophilic (meth) acrylate is 30% by mass or more, the hydrophilicity is sufficient and the antifouling property is improved. When the proportion of the bifunctional or higher hydrophilic (meth) acrylate is 80% by mass or less, the elastic modulus is increased and the scratch resistance is improved.

As the monofunctional monomer, a hydrophilic monofunctional monomer is preferable.
Examples of the hydrophilic monofunctional monomer include monofunctional (meth) acrylate having a polyethylene glycol chain in the ester group such as M-20G, M-90G, M-230G (manufactured by Shin-Nakamura Chemical Co., Ltd.), hydroxyalkyl (meth) acrylate, etc. And cationic monomers such as monofunctional (meth) acrylates having a hydroxyl group in the ester group, monofunctional acrylamides, methacrylamidopropyltrimethylammonium methyl sulfate, and methacryloyloxyethyltrimethylammonium methyl sulfate.
Moreover, as a monofunctional monomer, you may use viscosity modifiers, such as acryloyl morpholine and vinyl pyrrolidone, adhesive improvement agents, such as acryloyl isocyanate which improves the adhesiveness to a base material, etc.

  The proportion of the monofunctional monomer is preferably 0 to 20% by mass, and more preferably 5 to 15% by mass. By using a monofunctional monomer, the adhesion between the substrate and the cured resin is improved. When the proportion of the monofunctional monomer is 20% by mass or less, antifouling property or scratch resistance is sufficient without a shortage of tetrafunctional or higher polyfunctional (meth) acrylate or bifunctional or higher hydrophilic (meth) acrylate. Expressed in

  The monofunctional monomer may be blended in the active energy ray-curable resin composition in an amount of 0 to 35 parts by mass as a polymer having a low polymerization degree obtained by (co) polymerizing one type or two or more types. As a polymer having a low degree of polymerization, 40/60 of monofunctional (meth) acrylates having a polyethylene glycol chain in an ester group such as M-230G (manufactured by Shin-Nakamura Chemical Co., Ltd.) and methacrylamide propyltrimethylammonium methyl sulfate. Copolymer oligomer (MRC Unitech Co., Ltd., MG polymer) and the like can be mentioned.

(Other)
The active energy ray-curable resin composition may contain a polymerizable compound and a polymerization initiator other than the compounds used in the composition capable of forming the hydrophobic material or the hydrophilic material described above.
Examples of the polymerizable compound include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule.
The active energy ray-curable resin composition may contain a non-reactive polymer and an active energy ray sol-gel reactive composition.

Examples of the monomer having a radical polymerizable bond include a monofunctional monomer and a polyfunctional monomer.
Monofunctional monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, s-butyl (meth) acrylate, t- Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, Phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, allyl (meth) acrylate, 2-hydroxyethyl ( )) (Meth) acrylate derivatives such as acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate; (meth) acrylic acid, (meth) acrylonitrile; styrene, α -Styrene derivatives, such as methylstyrene, etc. are mentioned. These may be used alone or in combination of two or more.

  Polyfunctional monomers include ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, isocyanuric acid ethylene oxide modified di (meth) acrylate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate , Neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, polybutylene glycol di (Meth) acrylate, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxyethoxyphenyl) propane, 2,2-bis (4- (3- ( Ta) acryloxy-2-hydroxypropoxy) phenyl) propane, 1,2-bis (3- (meth) acryloxy-2-hydroxypropoxy) ethane, 1,4-bis (3- (meth) acryloxy-2-hydroxypropoxy) ) Butane, dimethylol tricyclodecane di (meth) acrylate, ethylene oxide adduct di (meth) acrylate of bisphenol A, propylene oxide adduct di (meth) acrylate of bisphenol A, neopentyl glycol di (meth) hydroxypivalate Bifunctional monomers such as acrylate, divinylbenzene, and methylenebisacrylamide; pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide Functional tri (meth) acrylate, trimethylolpropane propylene oxide modified triacrylate, trimethylolpropane ethylene oxide modified triacrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate and other trifunctional monomers; dipentaerystol hexa (meth) acrylate Tetrafunctional or higher monomers such as dipentaerystol penta (meth) acrylate, ditrimethylolpropane tetraacrylate, tetramethylolmethane tetra (meth) acrylate; bifunctional or higher urethane acrylate, bifunctional or higher polyester acrylate, etc. . These may be used alone or in combination of two or more.

  Examples of the monomer having a cationic polymerizable bond include monomers having an epoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group, and the like, and a monomer having an epoxy group is particularly preferable.

  Examples of the oligomer or reactive polymer include unsaturated polyesters such as a condensate of unsaturated dicarboxylic acid and polyhydric alcohol; polyester (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, epoxy (meth) Examples thereof include acrylates, urethane (meth) acrylates, cationic polymerization type epoxy compounds, homopolymers of the above-described monomers having a radical polymerizable bond in the side chain, and copolymerized polymers.

Examples of non-reactive polymers include acrylic resins, styrene resins, polyurethanes, cellulose resins, polyvinyl butyral, polyesters, thermoplastic elastomers, and the like.
Examples of the active energy ray sol-gel reactive composition include alkoxysilane compounds and alkyl silicate compounds.

Examples of the alkoxysilane compound include compounds represented by the following formula (5).
R ⁵¹ _x Si (OR ⁵² ) _y (5).
^However, R ^{51, R 52} each represent an alkyl group having 1 to 10 carbon atoms, x, y represents an integer satisfying the relation of x + y = 4.

  Examples of the alkoxysilane compound include tetramethoxysilane, tetra-i-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-t-butoxysilane, methyltriethoxysilane, Examples include methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, trimethylpropoxysilane, and trimethylbutoxysilane.

Examples of the alkyl silicate compound include a compound represented by the following formula (6).
R ⁶¹ O [Si (OR ⁶³ ) (OR ⁶⁴ ) O] _z R ⁶² (6).
^However, R 61 ^{to R 64} each represent an alkyl group having 1 to 5 carbon atoms, z is an integer of 3 to 20.

  Examples of the alkyl silicate compound include methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate, n-butyl silicate, n-pentyl silicate, acetyl silicate and the like.

  When utilizing a photocuring reaction, examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, benzophenone, p-methoxybenzophenone, 2,2-diethoxy. Acetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropane- Carbonyl compounds such as 1-one; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoyl Examples include diethoxyphosphine oxide. These may be used alone or in combination of two or more.

  When using an electron beam curing reaction, examples of the polymerization initiator include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, t- Thioxanthone such as butylanthraquinone, 2-ethylanthraquinone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl Dimethyl ketal, 1-hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholy Acetophenone such as phenyl) -butanone; benzoin ether such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl)- Acylphosphine oxides such as 2,4,4-trimethylpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoylformate, 1,7-bisacridinylheptane, 9-phenyl Examples include acridine. These may be used alone or in combination of two or more.

  When utilizing a thermosetting reaction, examples of the thermal polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxy octoate, organic peroxides such as t-butylperoxybenzoate and lauroyl peroxide; azo compounds such as azobisisobutyronitrile; N, N-dimethylaniline, N, N-dimethyl-p- Examples thereof include a redox polymerization initiator combined with an amine such as toluidine.

  As for the quantity of a polymerization initiator, 0.1-10 mass parts is preferable with respect to 100 mass parts of polymeric compounds. When the amount of the polymerization initiator is less than 0.1 parts by mass, the polymerization is difficult to proceed. When the amount of the polymerization initiator exceeds 10 parts by mass, the cured film may be colored or the mechanical strength may be lowered.

  The active energy ray-curable resin composition may contain additives such as an antistatic agent and a release agent; fine particles and a small amount of a solvent, as necessary.

  The antifogging transparent member of the present invention is particularly suitable for a shield member of a helmet, for example, but is also suitable for a glass member for glasses or a camera, a member for a window glass, a member for a windshield of an automobile, etc. Yes.

The antifogging transparent member 10 described above has a fine concavo-convex structure having a plurality of convex portions on the surface, and the fine concavo-convex structure is formed by transferring the fine concavo-convex structure on the surface of the anodized alumina. As a result, the antifogging property is excellent.
In particular, if the surface is formed of a hydrophobic material, super water repellency is obtained, and water stains are less likely to adhere, thereby exhibiting sufficient antifogging properties. Moreover, since water droplets are difficult to adhere, antifouling properties and anti-icing properties can be exhibited.
In addition, if the surface is formed from a hydrophilic material, super hydrophilicity is obtained, anti-fogging properties are exhibited, dirt attached to the surface is washed away with water, and oil dirt is less likely to adhere. Sufficient antifouling property can also be expressed.

In addition, the antifogging transparent member of this invention is not limited to the antifogging transparent member 10 of the example of illustration. For example, in the antifogging transparent member 10, the fine concavo-convex structure is formed on the surface of the cured resin film 20 of the antifogging film 16, but directly formed on the surface of the film body 18 without providing the cured resin film 20. It may be formed directly on the surface of the base body 12 without sticking the antifogging film 16. However, the cured resin film 20 of the antifogging film 16 from the point that a fine uneven structure can be efficiently formed using the roll-shaped mold 22 and the antifogging film 16 can be reattached when the fine uneven structure is damaged. It is preferable that a fine concavo-convex structure is formed on the surface.
Further, a similar fine uneven structure may be formed on the surface opposite to the surface on which the fine uneven structure is formed.

<Article>
The article of the present invention comprises the antifogging transparent member of the present invention.
FIG. 4 is a perspective view showing an example of the article of the present invention, specifically, a helmet. In the helmet 50 of this example, the antifogging transparent member of the present invention is used in the shield 52 portion.
Since the helmet 50 includes the anti-fogging transparent member of the present invention, the helmet 50 is excellent in anti-fogging property and can secure a good field of view.

  The article of the present invention is particularly suitable for helmets, but is also suitable for glasses, cameras, window glass, automobile windshields, and the like.

Since the article of the present invention described above includes the anti-fogging transparent member of the present invention, it is excellent in anti-fogging property. In particular, when an anti-fogging transparent member having a surface formed of a hydrophobic material is used, water droplets are less likely to adhere, so that the anti-fogging property is improved and the anti-fouling property and anti-icing property are also excellent. In addition, if an antifogging transparent member having a surface formed of a hydrophilic material is used, dirt attached to the surface is washed away with water, and oil stains are less likely to adhere, so that the antifouling property is excellent.
Therefore, since the article of the present invention is not easily fogged, a good field of view can be secured.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

(Pores of anodized alumina)
A part of the anodized alumina is shaved, platinum is vapor-deposited on the cross section for 1 minute, and the cross section is subjected to an acceleration voltage of 3.00 kV using a field emission scanning electron microscope (JSM-7400F, manufactured by JEOL Ltd.). Observed and measured pore spacing and pore depth. Each measurement was performed for 50 points, and the average value was obtained.

(Convex part of cured resin film)
Platinum was vapor-deposited on the fracture surface of the cured resin film for 10 minutes, and the cross-section was observed in the same manner as the anodized alumina, and the interval between the convex portions and the height of the convex portions were measured. Each measurement was performed for 50 points, and the average value was obtained.

(Hydrophilicity test)
After attaching fingerprints to each sample, the appearance when wiping with Toraysee (made by Toray Industries Co., Ltd.), which was thoroughly soaked with tap water and squeezed to the extent that water drops did not drop, was evaluated according to the following criteria. .
○: Dirt is not visually recognized.
Δ: Some fingerprints are visually confirmed.
X: The fingerprint spreads and is hardly wiped off.

(Hydrophobic test)
Water was sprayed onto each vertically leaned sample with a spray, and the surface water repellency was evaluated according to the following criteria.
○: Almost no water droplets remain.
Δ: Some water droplets remain.
X: Many water droplets remain or the sample surface is wet with water.

(Water contact angle)
Using a contact angle measuring device (manufactured by Kruss, DSA10-Mk2), 1.6 μL of water was dropped on the surface of the fine concavo-convex structure of the cured resin film, and after 10 seconds of dropping, the water contact angle was 1 second apart. 10 points were measured, and the average value was obtained. Furthermore, the same operation was performed 3 times by changing the position where water was dropped, and the average value of 4 times in total was further averaged.

[Manufacture of roll mold]
A roll made of aluminum having a purity of 99.99% was electropolished in a perchloric acid / ethanol mixed solution (1/4 volume ratio).
(A) Process:
The roll was anodized in a 0.5 M oxalic acid aqueous solution for 6 hours under the conditions of a direct current of 40 V and a temperature of 16 ° C.
(B) Process:
The roll on which the oxide film was formed was immersed in a 6% by mass phosphoric acid / 1.8% by mass chromic acid mixed aqueous solution for 6 hours to remove the oxide film.

(C) Process:
The roll was anodized in a 0.3 M oxalic acid aqueous solution for 30 seconds under the conditions of a direct current of 40 V and a temperature of 16 ° C.
(D) Process:
The roll on which the oxide film was formed was immersed in 5 mass% phosphoric acid at 32 ° C. for 8 minutes to carry out pore diameter expansion treatment.

(E) Process:
The step (c) and the step (d) are repeated a total of 5 times to obtain a roll-shaped mold a having anodized alumina having substantially conical pores with an average interval of 100 nm and a depth of 240 nm formed on the surface. It was.
The roll-shaped mold a was immersed in a 0.1% by weight diluted solution of OPTOOL DSX (manufactured by Daikin Chemicals Sales Co., Ltd.) and air-dried overnight to subject the oxide film surface to a fluorination treatment.

[Preparation of active energy ray-curable resin composition]
Each component was mixed in the ratio shown in Table 1 and Table 2, and active energy ray-curable resin compositions A and B were prepared.

Abbreviations in the table are as follows.
DPHA: dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd., Aronix M400),
M260: polyethylene glycol diacrylate n = 13-14 (Toagosei Co., Ltd., Aronix M260),
HEA: 2-hydroxyethyl acrylate,
Ir184: 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals).

Abbreviations in the table are as follows.
TAS: trimethylolethane, acrylic acid, succinic anhydride condensed ester,
C6DA: 1,6-hexanediol diacrylate,
X-22-1602: radical polymerizable silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.)
Ir184: 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals).

[Production of film]
75 parts by mass of a rubber-containing multistage polymer obtained by polymerizing methyl methacrylate, butyl acrylate, methyl acrylate, 1,3-butadiene and allyl methacrylate, and 25 parts by mass of an acrylic resin (BR80 manufactured by Mitsubishi Rayon Co., Ltd.) The part was melt-extruded in advance and then formed into a 200 μm thick acrylic resin film.

[Example 1]
A hydrophilic antifogging film was produced using the production apparatus shown in FIG.
As the roll mold 22, the roll mold a was used.
The active energy ray curable resin composition A was used as the active energy ray curable resin composition.
As the film body 18, the acrylic resin film was used.
The active energy ray-curable resin composition A was cured by irradiating the coating film of the active energy ray-curable resin composition A with ultraviolet rays having an integrated light amount of 3200 mJ / cm ² from the film body 18 side.

About the obtained hydrophilic anti-fogging film, the average space | interval between convex parts and the height of a convex part were measured. The results are shown in Table 3.
The obtained hydrophilic antifogging film was stuck on a glass plate having a thickness of 2 mm via a double-sided adhesive tape (manufactured by Nitto Denko Corporation, CS9621) to obtain a hydrophilic antifogging transparent member. For the hydrophilic antifogging transparent member, a hydrophilicity test and a water contact angle were measured. The results are shown in Table 3.

[Example 2]
A hydrophobic antifogging film and a hydrophobic antifogging transparent member were obtained in the same manner as in Example 1 except that the active energy ray-curable resin composition B was used. About the hydrophobic anti-fogging film, the average space | interval between convex parts and the height of a convex part were measured. The results are shown in Table 3. Further, the hydrophobicity test and the water contact angle were measured for the hydrophobic antifogging transparent member. The results are shown in Table 3.

  The anti-fogging transparent member of the present invention is excellent in anti-fogging property and is particularly useful as a shield for helmets, for example.

It is sectional drawing which shows an example of the anti-fogging transparent member of this invention. It is a block diagram which shows an example of the manufacturing apparatus of the anti-fogging film used for this invention anti-fogging transparent member. It is sectional drawing which shows the manufacturing process of the mold which has an anodized alumina on the surface. It is sectional drawing which shows an example of the articles | goods of this invention.

Explanation of symbols

10 Antifogging transparent member 50 Article (helmet)

Claims (2)

An anti-fogging transparent member having a fine uneven structure on the surface,
An antifogging transparent member, wherein the fine concavo-convex structure is formed by transferring a fine concavo-convex structure on the surface of anodized alumina.   An article comprising the antifogging transparent member according to claim 1.

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