JP2013039711A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having excellent adhesiveness at the interface between a surface layer having a fine irregular structure and an intermediate layer and at the interface between the intermediate layer and a base material.SOLUTION: The laminate 1 includes: a base material 2; the surface layer 4 having the fine irregular structure consisting of a plurality of convex parts 3; and an intermediate layer 5 formed between the base material 2 and the surface layer 4. The intermediate layer 5 is formed by hardening a composition for formation of the intermediate layer containing 40-95 mass% of (A) a (poly)alkyleneglycolmono(meth)acrylate having at least one oxypropylene group in a (poly)alkyleneglycol chain and 5-60 mass% of (B) N,N-dimethyl(meth)acrylamide.

Description

  The present invention relates to a laminate having a surface layer having a fine concavo-convex structure on the surface thereof.

  It is known that a fine concavo-convex structure having a fine concavo-convex structure on the surface exhibits antireflection performance due to a continuous change in refractive index. In addition, the fine concavo-convex structure can also exhibit super water-repellent performance by the Lotus effect.

As such a fine concavo-convex structure, for example, a laminate having a surface layer having a fine concavo-convex structure on the surface is known. As a method for producing this laminate, for example, a so-called nanoimprint method having the following steps (i) to (iii) is known.
(I) A step of sandwiching an active energy ray-curable composition between a mold having a reverse structure of a fine concavo-convex structure on a surface and a substrate.
(Ii) The active energy ray-curable composition is irradiated with active energy rays such as ultraviolet rays, and the active energy ray-curable composition is cured to form a surface layer having a fine concavo-convex structure on the surface. The process of obtaining the laminated body which becomes.
(Iii) A step of separating the laminate and the mold.

  In order for the fine concavo-convex structure to exhibit good antireflection performance, it is necessary that the interval between adjacent convex portions or concave portions be equal to or less than the wavelength of visible light. The surface layer having such a fine concavo-convex structure on the surface is hardened with the same active energy ray-curable composition, and has a higher adhesion to the adhesive than a hard coat layer with a smooth surface. When the peeling test between the base material and the surface layer is performed, there is a problem that the surface layer is easily peeled off from the base material.

In addition, in order to improve the mechanical characteristics of a laminated body, the laminated body which provided the intermediate | middle layer between the base material and the surface layer is disclosed (patent document 1).
However, this laminate does not have sufficient adhesion at the interface between the substrate and the intermediate layer and at the interface between the intermediate layer and the surface layer. In particular, when the surface layer is continuously formed on the surface of the intermediate layer provided on the surface of the substrate, the set time of the surface layer is shortened, so that it is difficult to ensure the adhesion between the intermediate layer and the surface layer. .

JP 2011-000856 A

  The present invention provides a laminate having excellent adhesion at the interface between a surface layer and an intermediate layer having a fine concavo-convex structure on the surface and at the interface between the intermediate layer and a substrate.

The laminate of the present invention has a base material, a surface layer having a fine concavo-convex structure on the surface, and an intermediate layer provided between the base material and the surface layer, and the intermediate layer forms the following intermediate layer It is a layer formed by curing the composition for use.
(Composition for intermediate layer formation)
A composition for forming an intermediate layer containing a polymerization reactive compound, wherein the polymerization reaction compound is a (poly) alkylene glycol mono (meth) acrylate (A) represented by the following formula (1), N, N -Dimethyl (meth) acrylamide (B), the proportion of the (poly) alkylene glycol mono (meth) acrylate (A) is 40 to 95% by mass in 100% by mass of the polymerization reactive compound, The ratio of the N, N-dimethyl (meth) acrylamide (B) is 5 to 60% by mass in 100% by mass of the polymerization reactive compound.
^{_{CH 2 = CR 1 -C (O}} ) O- (AO) m -R 2 ··· (1).
However, the average value of m is 1 or more, A is an alkylene group, R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom, an alkyl group or an aryl group, and is represented by (AO) _m At least one (C ₃ H ₆ O) is included in the structure.
The thickness of the intermediate layer is preferably 1 to 40 μm.

  The laminate of the present invention is excellent in adhesion at the interface between the surface layer and the intermediate layer having a fine uneven structure on the surface and at the interface between the intermediate layer and the substrate.

It is sectional drawing which shows an example of the laminated body of this invention. It is sectional drawing which shows the other example of the laminated body of this invention.

“(Poly) alkylene glycol” in the present specification means alkylene glycol or polyalkylene glycol.
As used herein, “(meth) acrylate” means acrylate and / or methacrylate.
As used herein, “(meth) acrylamide” means acrylamide and / or methacrylamide.
The “(meth) acryloyloxy group” in the present specification means an acryloyloxy group or a methacryloyloxy group.
“Transparent” in the present specification means that light is transmitted.
The “active energy rays” in the present specification means visible light, ultraviolet rays, electron beams, plasma, heat rays (infrared rays, etc.) and the like.
The “visible light” in the present invention means light having a wavelength of 380 to 780 nm.

<Laminated body>
The laminate of the present invention has a substrate, a surface layer having a fine relief structure on the surface, and an intermediate layer provided between the substrate and the surface layer.

  FIG. 1 is a cross-sectional view showing an example of the laminate of the present invention. The laminate 1 is provided between the substrate 2 and the surface layer 4 so as to be in contact with the substrate 2, the surface layer 4 having a fine concavo-convex structure composed of a plurality of convex portions 3 on the surface, and the substrate 2 and the surface layer 4. And the intermediate layer 5 formed.

(Base material)
As the base material 2, when applying the laminated body 1 to an antireflection article, the transparent base material which permeate | transmits light is preferable.
Examples of the material of the substrate 2 include synthetic polymers ((meth) acrylate-based (co) polymers, polycarbonates, styrene (co) polymers, (meth) acrylate-styrene copolymers, etc.), semi-synthetic polymers. (Cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, etc.), polyester (polyethylene terephthalate, polylactic acid, etc.), polyamide, polyimide, polyether sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal , Polyether ketone, polyurethane, composites thereof (composites of polymethyl methacrylate and polylactic acid, composites of polymethyl methacrylate and polyvinyl chloride, etc.), glass and the like.

Examples of the method for producing the substrate 2 include an injection molding method, an extrusion molding method, a calendar molding method, a cell cast molding method, a solution casting method, a thermosetting method, a drying curing method, and an ultraviolet curing method.
Examples of the shape of the substrate 2 include a sheet shape and a film shape.
The surface of the substrate 2 may be subjected to a coating treatment or a corona treatment for the purpose of improving properties such as adhesion, antistatic properties, scratch resistance, and weather resistance.
Although the thickness of the base material 2 is not specifically limited, From the viewpoint of productivity in the step of providing the intermediate layer 5 and the surface layer 4, a thickness that can be bent is preferable, and 500 μm or less is more preferable.

(Surface)
The surface layer 4 is a cured resin film formed by curing a composition for forming a surface layer, which will be described later, and has a fine concavo-convex structure on the surface that exhibits functions such as antireflection performance and water repellency.
The fine concavo-convex structure includes a plurality of convex portions 3 formed at equal intervals and concave portions 6 between the convex portions 3.

  The shape of the convex part 3 is a cone shape or a pyramid shape. In addition, the shape of the convex part 3 may be a bell shape in which the top part of the convex part 3 is a curved surface as shown in FIG. The shape of the convex part 3 is not limited to the shape of the example of illustration, What is necessary is just a shape where the width | variety in the cross-sectional area of a height direction becomes large gradually as it goes to a bottom part from a top part. Moreover, the fine protrusions may be united to form the convex portion 3. That is, the shape may be any shape as long as the refractive index continuously increases from the air to the material of the surface layer 4 and exhibits antireflection performance that achieves both low reflectance and low wavelength dependency.

  The distance i between the convex portions 3, that is, the distance between the vertex 7 of the convex portion 3 and the vertex 7 of the convex portion 3 adjacent thereto must be equal to or less than the wavelength of visible light. If the interval i between the convex portions 3 is 380 nm or less, scattering of visible light can be suppressed, and the laminate 1 can be suitably used for optical applications such as antireflection articles.

  The height h of the convex portion 3, that is, the vertical distance between the bottom point 8 of the concave portion 6 and the vertex 7 of the convex portion 3 is preferably 60 nm or more from the viewpoint of suppressing an increase in the minimum reflectance and the reflectance at a specific wavelength, 90 nm or more is more preferable.

  6-29 micrometers is preferable and, as for the thickness of the surface layer 4, 8-21 micrometers is more preferable. If the thickness of the surface layer 4 is 29 micrometers or less, hardening of the composition for surface layer formation will fully advance by normal ultraviolet irradiation. If the thickness of the surface layer 4 is 6 μm or more, the surface layer 4 can be prevented from being easily broken.

  The cured resin film constituting the surface layer 4 preferably has a high crosslinking density and high elasticity from the viewpoint of satisfactorily forming a fine uneven structure on the surface layer 4. With a cured resin film having a high crosslinking density, it is difficult to obtain a tensile elongation, and the tensile elongation at break is usually preferably 5% or less. For this reason, if the surface layer 4 is too thin, the surface layer 4 will be tensile-ruptured when a load is applied to the laminate 1, and the crack will remain as a scratch that can be visually confirmed. On the other hand, if the surface layer 4 is too thick, the stress applied to the laminate 1 is not well dispersed by the base material 2 and the cured resin film of the surface layer 4 is damaged.

  The surface layer 4 and the intermediate layer 5 may be in a mixed state where no clear interface exists. By allowing the composition for forming the surface layer constituting the surface layer 4 to permeate into the intermediate layer 5, it is possible to express good adhesion without causing a clear interface. In addition, the thickness of both layers when there is no clear interface is measured using the intermediate position of the mixed portion between the intermediate layer 5 and the surface layer 4 as the interface. In addition, the adhesion with the intermediate layer 5 can be improved by applying heat when forming the surface layer 4.

(Surface layer forming composition)
The composition for forming a surface layer contains a polymerization reactive compound, and is preferably an active energy ray-curable composition that cures by irradiating an active energy ray so that a polymerization reaction proceeds.
The active energy ray-curable composition contains a polymerization reactive compound, an active energy ray polymerization initiator, and other components as necessary.

  As a polymerization reactive compound or an active energy ray polymerization initiator suitable for forming a fine concavo-convex structure, a known compound can be employed. Examples of the polymerization reactive compound include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule. Examples of the monofunctional or polyfunctional monomer having a radical polymerizable bond include various (meth) acrylates and derivatives thereof. 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. As a polymerization reactive compound and an active energy ray polymerization initiator suitable for forming a fine concavo-convex structure, for example, various compounds described in paragraph [0018] and thereafter in JP-A-2009-031764 can be employed.

  The composition for forming the surface layer is composed of an ultraviolet absorber, an antioxidant, a release agent, a lubricant, a plasticizer, an antistatic agent, a light stabilizer, a flame retardant, a flame retardant, a polymerization inhibitor, and a filling agent as necessary. An additive such as an agent, a silane coupling agent, a colorant, a reinforcing agent, an inorganic filler, and an impact modifier may be included.

  The viscosity at 25 ° C. of the surface layer forming composition is preferably 10000 mPa · s or less, preferably 5000 mPa · s or less, from the viewpoint of workability when the surface layer forming composition is poured into a mold and cured to form a fine relief structure. Is more preferable, and 2000 mPa · s or less is particularly preferable. However, even if the viscosity of the composition for forming the surface layer exceeds 10,000 mPa · s, if the composition for forming the surface layer can be preliminarily heated to lower the viscosity when poured into the mold, it is used without impairing workability. be able to. The viscosity at 70 ° C. of the composition for forming a surface layer is preferably 5000 mPa · s or less, and more preferably 2000 mPa · s or less.

  The viscosity at 25 ° C. of the composition for forming the surface layer is preferably 100 mPa · s or more, preferably 150 mPa · s or more, from the viewpoint of workability when continuously forming a fine uneven structure using a belt-shaped or roll-shaped mold. Is more preferable, and 200 mPa · s or more is particularly preferable. These ranges are such that when the mold is pressed against the surface layer forming composition, the surface layer forming composition does not easily leak to the side beyond the width of the mold, or the thickness of the cured resin film formed by curing the surface layer forming composition. This is significant in that it can be easily adjusted arbitrarily.

The viscosity of the surface layer forming composition can be adjusted by adjusting the type and content of the monomer. Specifically, when a large amount of a functional group having an intermolecular interaction such as a hydrogen bond or a monomer having a chemical structure is used, the viscosity of the surface layer forming composition increases. On the other hand, when a large amount of a low molecular weight monomer having no intermolecular interaction is used, the viscosity of the surface layer forming composition is lowered.
The viscosity of the surface layer forming composition is measured using a rotary B-type viscometer at a predetermined temperature.

When the cured resin film formed by curing the composition for forming the surface layer is soft, the nano-sized convex portions 3 may come close to each other when or after peeling from the mold for forming the fine concavo-convex structure. In the nano region, even a surface tension that does not cause a problem in the macro region works remarkably. That is, in order to reduce the surface free energy, a force is applied to close the nano-sized convex portions 3 to reduce the surface area. When this force exceeds the hardness of the cured resin film, the convex portions 3 are closely attached to each other. In such a fine concavo-convex structure, functions such as desired antireflection performance and water repellency may not be exhibited.
From the above points, the tensile elastic modulus of the cured resin film is preferably 1 GPa or more. By using a composition for forming a surface layer such that the tensile modulus after curing is 1 GPa or more, it becomes easy to avoid the protrusions 3 from snuggling together.

(Middle layer)
The intermediate layer 5 is a cured resin film formed by curing an intermediate layer forming composition described later. The intermediate layer 5 may be one layer or two or more layers, but one layer is preferable from the viewpoint of productivity and cost.

  The thickness of the intermediate layer 5 is preferably 1 to 40 μm, and more preferably 8 to 20 μm. If the thickness of the intermediate layer 5 is 1 μm or more, cohesive failure of the intermediate layer 5 when the surface layer 4 is peeled can be prevented. If the thickness of the intermediate layer 5 is 40 μm or less, the thickness can be applied with high accuracy when the intermediate layer 5 is continuously formed by coating. If the thickness of the intermediate layer 5 is 8 μm or more, the surface layer 4 of the laminate 1 can be less damaged by dispersing energy such as indentation stress into the laminate 1 and friction on the surface of the laminate 1. If the thickness of the intermediate layer 5 is 20 μm or less, the amount of compressive deformation at the time of pressing can be suppressed, and the surface layer 4 can be prevented from cracking without being able to follow the amount of deformation. The thickness unevenness of the intermediate layer 5 is preferably within ± 2 μm, and more preferably within ± 1 μm.

(Composition for intermediate layer formation)
The composition for forming an intermediate layer contains a polymerization reactive compound, and is preferably an active energy ray-curable composition that cures by irradiating active energy rays so that a polymerization reaction proceeds.
The active energy ray-curable composition contains a polymerization reactive compound, an active energy ray polymerization initiator, and other components as necessary.

The polymerization reactive compound contains (poly) alkylene glycol mono (meth) acrylate (A) represented by the following formula (1) and N, N-dimethyl (meth) acrylamide (B).
^{_{CH 2 = CR 1 -C (O}} ) O- (AO) m -R 2 ··· (1).
However, the average value of m is 1 or more, A is an alkylene group, R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom, an alkyl group or an aryl group, and is represented by (AO) _m The structure to be prepared has at least one oxypropylene group (C ₃ H ₆ O).

  As the (poly) alkylene glycol mono (meth) acrylate (A), for example, a (meth) acryloyloxy group is introduced at one end of a polymer obtained by addition polymerization of propylene oxide, and an alkyl is added at the other end as necessary. Group or aryl group introduced; polypropylene glycol mono (meth) acrylate; a (meth) acryloyloxy group is introduced at one end of a copolymer of propylene oxide and ethylene oxide and / or butylene oxide, if necessary Those having an alkyl group or aryl group introduced at the other end; and the like.

  Commercially available products of (poly) alkylene glycol mono (meth) acrylate (A) include polypropylene glycol monoacrylate (manufactured by NOF Corporation, BLEMMER AP-150 (m≈3), AP-400 (m≈6), AP- 550 (m≈9), AP-800 (m≈13); Nonylphenoxypolypropylene glycol monoacrylate (manufactured by NOF Corporation, Bremer ANP-300 (m≈5)) and the like.

  The number average molecular weight of the (poly) alkylene glycol mono (meth) acrylate (A) is preferably 1000 or less, more preferably 750 or less, and particularly preferably 450 to 700. If the number average molecular weight is 1000 or less, the reactivity of (poly) alkylene glycol mono (meth) acrylate is sufficiently high, and a cured resin film having a sufficiently high molecular weight is formed, so that adhesion with the surface layer 4 is ensured. it can. If the number average molecular weight is 750 or less, since the compatibility between (poly) alkylene glycol mono (meth) acrylate (A) and N, N-dimethyl (meth) acrylamide (B) is high, a highly transparent cured resin A film is formed. If the number average molecular weight is 450 to 700, the above-described effects are exhibited, and the molecular weight of the (poly) alkylene glycol chain is sufficiently large. Therefore, the compatibility with the cured resin film of the surface layer 4 is high, and the intermediate layer 5 and the surface layer Adhesion with 4 is good.

  The ratio of the (poly) alkylene glycol mono (meth) acrylate (A) is 40 to 95% by mass and preferably 50 to 85% by mass in 100% by mass of the polymerization reactive compound. When the ratio of (poly) alkylene glycol mono (meth) acrylate (A) is 40% by mass or more, the flexibility of the cured resin film can be secured and sufficient adhesion with the surface layer 4 can be obtained. When the proportion of (poly) alkylene glycol mono (meth) acrylate (A) is 95% by mass or less, the reactivity of the intermediate layer forming composition can be ensured. If the ratio of (poly) alkylene glycol mono (meth) acrylate (A) is 50 to 85% by mass, the balance between the flexibility and cohesive force of the cured resin film will be good, and the adhesion to the surface layer 4 will be further improved. improves.

  The ratio of N, N-dimethyl (meth) acrylamide (B) is 5 to 60% by mass, preferably 15 to 50% by mass, out of 100% by mass of the polymerization reactive compound. When the proportion of N, N-dimethyl (meth) acrylamide (B) is 5% by mass or more, the adhesion of the cured resin film by the amide group is ensured. When the ratio of N, N-dimethyl (meth) acrylamide (B) is 60% by mass or less, the flexibility of the cured resin film can be ensured and the adhesion with the surface layer 4 can be ensured. If the ratio of N, N-dimethyl (meth) acrylamide (B) is 15 to 50% by mass, the balance between the flexibility and cohesive force of the cured resin film is improved, and the adhesion to the surface layer 4 is further improved. To do.

  The composition for forming an intermediate layer may contain a polymerization reactive compound other than (poly) alkylene glycol mono (meth) acrylate (A) and N, N-dimethyl (meth) acrylamide (B). The proportion of the other polymerization-reactive compound is preferably 0 to 45% by mass in 100% by mass of the polymerization-reactive compound. The other polymerization reactive compound is not particularly limited as long as it can form the intermediate layer 5 made of the cured resin film by a curing reaction. As other polymerization-reactive compounds, components that contribute to adhesion to the substrate 2 and the surface layer 4 are preferable.

  As a component that contributes to adhesion with the substrate 2 and the surface layer 4, a monomer having a polar site capable of forming a hydrogen bond is preferable. Examples of the polar site include a urethane bond, a carboxyl group, and a hydroxyl group. Specific examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, and succinic acid. Specific examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, N-methylol ( And (meth) acrylamide and lactone-modified (meth) acrylate (such as “Placcel (registered trademark)” series manufactured by Daicel Chemical Industries).

  A polyfunctional monomer may be used as another polymerization reactive compound. Specific examples of the polyfunctional monomer include monomers having a plurality of polymerizable double bonds and a hydroxyl group such as pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate. Specific examples of the polyfunctional monomer having a urethane bond include polyfunctional urethane (meth) acrylate. Examples of commercially available products of multifunctional monomers include Daicel Cytec's “Ebecryl (registered trademark)” series, Toagosei “Aronix (registered trademark)” series, and Nippon Kayaku Co., Ltd. “KAYARAD (registered trademark). ) ”Series.

The active energy ray polymerization initiator is a compound that generates a radical that is cleaved by irradiating active energy rays to initiate a polymerization reaction of the polymerization reactive compound. As the active energy ray, ultraviolet rays are preferable from the viewpoint of apparatus cost and productivity.
The type and amount of the active energy ray polymerization initiator may be appropriately determined according to, for example, the environment in which the active energy ray is irradiated (in the presence of oxygen, under a nitrogen atmosphere, etc.). The amount used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerization reactive compound.

  Examples of the active energy ray polymerization initiator include 1-hydroxy-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methylphenylglyoxylate, acetophenone, benzophenone, diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-phenyl-1,2-propane-dione-2- (o-ethoxycarbonyl) oxime, 2-methyl [4- (methylthio) phenyl] -2-morpholino-1 -Propanone, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-chlorothioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphos In'okishido, diphenylphosphine oxide, 2-methyl-benzoyl diphenyl phosphine oxide, benzoyl dimethoxy phosphine oxide, and the like. An active energy ray polymerization initiator may be used individually by 1 type, and may be used in combination of 2 or more type.

The intermediate layer forming composition may be diluted with a solvent as necessary. In particular, when uniform application is difficult due to high viscosity, it is preferable to appropriately adjust the viscosity to be suitable for the coating method. Moreover, the adhesiveness of the base material 2 and the intermediate | middle layer 5 can also be improved by melt | dissolving a part of surface of the base material 2 with a solvent.
As the solvent, a solvent having an appropriate boiling point may be selected according to the drying method and the like. Specific examples of the solvent include toluene, methyl ethyl ketone, cyclohexanone, alcohols (such as isopropyl alcohol). A solvent may be used individually by 1 type and may be used in combination of 2 or more type.

  The composition for forming an intermediate layer is filled with an ultraviolet absorber, an antioxidant, a release agent, a lubricant, a plasticizer, an antistatic agent, a light stabilizer, a flame retardant, a flame retardant, a polymerization inhibitor, and a filling agent as necessary. Additives such as an agent, a silane coupling agent, a colorant, a reinforcing agent, an inorganic filler, an impact modifier, and a near infrared absorber may be included.

  When the composition for forming an intermediate layer contains an antistatic agent, it is possible to obtain a laminate 1 that is difficult to adhere dust and the like. Examples of the antistatic agent include conductive polymers (polythiol-based, polythiophene-based, polyaniline-based, etc.), inorganic fine particles (carbon nanotubes, carbon black, etc.), lithium salts described in JP-A-2007-070449, 4 Class ammonium salt etc. are mentioned. One antistatic agent may be used alone, or two or more antistatic agents may be used in combination. The antistatic agent is preferably a perfluoroalkyl acid lithium salt that does not impair the transparency of the laminate 1, is relatively inexpensive, and exhibits stable performance.

The addition amount of the antistatic agent is preferably 0.5 to 20 parts by mass and more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the polymerization reactive compound. If the addition amount of the antistatic agent is 0.5 parts by mass or more, the surface resistance value of the laminate 1 is lowered and the dust adhesion preventing performance is exhibited. Moreover, 20 mass parts or less are preferable from a cost surface.
Further, in order to exhibit good antistatic performance, the thickness of the surface layer 4 laminated on the intermediate layer 5 is preferably 100 μm or less, and particularly preferably 50 μm or less.

  When the composition for forming an intermediate layer contains a near-infrared absorber, the laminate 1 can be provided with a heat insulating effect, or when used for a plasma display or the like, it can prevent malfunction of an infrared remote controller of various home appliances. . Examples of the near infrared absorber include organic near infrared absorbers (diimonium dyes, phthalocyanine dyes, dithiol metal complex dyes, substituted benzenedithiol metal complex dyes, cyanine dyes, squalium dyes, etc.), inorganic System near infrared absorbers (conductive antimony-containing tin oxide fine particles, conductive tin-containing indium oxide fine particles, tungsten oxide fine particles, composite tungsten oxide fine particles, etc.). A near-infrared absorber may be used individually by 1 type, and may be used in combination of 2 or more type.

  Various additives may be added to the surface layer 4 of the laminate 1, but there is a concern that the performance may deteriorate due to bleed-out over time. By adding to the intermediate layer 5, bleeding out can be suppressed and prevented.

  The viscosity of the intermediate layer forming composition may be adjusted to an optimum value according to the coating method. Moreover, what is necessary is just to select an appropriate coating method according to the viscosity of the composition for intermediate | middle layer formation. For example, when the viscosity is 50 mPa · s or less, it can be uniformly applied to the surface of the substrate 2 by gravure coating.

(Use)
The laminate of the present invention is optimal as a functional article having a fine concavo-convex structure on the surface. Examples of the functional article include an antireflection article and a water repellent article provided with the laminate of the present invention. In particular, a display or an automobile member provided with the laminate of the present invention is suitable as a functional article.

  The antireflection article provided with the laminate of the present invention exhibits high scratch resistance and good antireflection performance. Examples of the antireflection article include various display devices such as image display devices (liquid crystal display devices, plasma display panels, electroluminescence displays, cathode tube display devices, etc.), surfaces of objects such as lenses, show windows, and spectacle lenses. In addition, those having the laminate of the present invention attached thereto may be mentioned.

  The water repellent article provided with the laminate of the present invention exhibits high scratch resistance and good water repellency, and also exhibits excellent antireflection performance. Examples of the water-repellent article include those in which the laminate of the present invention is attached to the surface of an object such as a window material, roof tile, outdoor lighting, a curved mirror, a vehicle window, or a vehicle mirror.

When the part to which the laminated body in each object is attached is a three-dimensional shape, prepare a base material having a shape corresponding to the shape in advance, and form an intermediate layer and a surface layer on the base material to obtain a laminated body. After that, the laminate may be attached to a predetermined portion of the object.
In addition, when the object is an image display device, the laminate of the present invention may be attached to the front plate, not limited to the surface thereof, or the front plate itself is configured from the laminate of the present invention. You can also.
In addition to the uses described above, the laminate of the present invention can also be applied to optical uses such as optical waveguides, relief holograms, lenses, and polarization separation elements, and uses of cell culture sheets.

(Laminate manufacturing method)
The laminate of the present invention can be produced, for example, by a method having the following steps (I) to (II).
(I) The process of apply | coating the composition for intermediate | middle layer formation on the surface of a base material, and hardening the composition for intermediate | middle layer formation completely by irradiation of an active energy ray, and forming an intermediate | middle layer.
(II) A surface layer forming composition is arranged between a mold having a reverse structure of a fine concavo-convex structure on the surface and a substrate, and the surface layer forming composition is irradiated with active energy rays to cure the surface layer forming composition. Forming a surface layer having a fine concavo-convex structure on the surface to obtain a laminate comprising a base material, an intermediate layer, and a surface layer.

Step (I):
Step (I) is further divided into the following steps (I-1) to (I-3).
(I-1) The process of apply | coating the composition for intermediate | middle layer formation on the surface of a base material.
(I-2) The process of volatilizing a solvent, when the composition for intermediate | middle layer formation contains a solvent.
(I-3) A step of irradiating the composition for forming an intermediate layer with an active energy ray to cure the composition for forming an intermediate layer to form an intermediate layer.

Step (I-1):
First, the intermediate layer forming composition is applied to the surface of the substrate to form a coating film made of the intermediate layer forming composition.
The coating method may be selected from the known coating methods in consideration of the flexibility of the substrate and the viscosity of the intermediate layer forming composition. Specific examples include a method of controlling the thickness of the coating film with an air knife when applying the intermediate layer forming composition, and a method of applying the polysynthetic composition by gravure coating. Known coating methods are described in detail, for example, in JP-A-01-216837.

Step (I-2):
When the composition for forming an intermediate layer contains a solvent, it is necessary to dry the coating film formed on the surface of the substrate to volatilize and remove the solvent. At this time, volatilization of the solvent may be promoted by heating or reduced pressure. However, with rapid drying, care must be taken because only the surface of the coating film is dried and the solvent may remain inside the coating film. Specifically, an appropriate drying method may be selected depending on the type and content of the solvent. Also, care should be taken because the substrate may be deformed by heating.

Step (I-3):
The intermediate layer forming composition is irradiated with active energy rays, and the intermediate layer forming composition is cured to form the intermediate layer.
As the active energy ray, ultraviolet rays are preferable from the viewpoint of apparatus cost and productivity. Examples of the ultraviolet light source include a high-pressure mercury lamp, a metal halide lamp, and a fusion lamp.

What is necessary is just to determine suitably the irradiation amount of an ultraviolet-ray according to the absorption wavelength and quantity of the active energy ray polymerization initiator which the composition for intermediate | middle layer formation contains. Integrated light quantity is preferably from ^{100~10000mJ / cm 2, 150~6000mJ / cm} 2 is more preferable. If the integrated light quantity is 100 mJ / cm ² or more, the intermediate layer forming composition can be sufficiently cured. If the integrated light quantity is 10,000 mJ / cm ² or less, coloring of the intermediate layer and deterioration of the substrate can be prevented. The irradiation intensity is not particularly limited, but is preferably suppressed to an output that does not cause deterioration of the substrate.

  The atmosphere when irradiating with ultraviolet rays is preferably a nitrogen atmosphere from the viewpoint of promoting curing. In addition, the atmosphere when irradiating ultraviolet rays is preferably an oxygen concentration of 1% or less, particularly preferably an oxygen concentration of 0.1% or less. If the oxygen concentration is 1% or less, curing of the intermediate layer forming composition can be accelerated, and a completely cured cured resin film can be obtained.

Process (II):
Step (II) is further divided into the following steps (II-1) to (II-3).
(II-1) A step of sandwiching a surface layer forming composition between a mold having a reverse structure of a fine concavo-convex structure on a surface and a substrate.
(II-2) A surface layer-forming composition is irradiated with active energy rays, the surface layer-forming composition is cured to form a surface layer having a fine concavo-convex structure on the surface, and a laminate composed of a substrate, an intermediate layer, and a surface layer The process of obtaining a body.
(II-3) The process of isolate | separating a laminated body and a mold.

  As a method for forming the surface layer in the step (II), a method for producing the mold used in the step (II), etc., for example, a publicly known method described in JP-A-2009-031764 may be employed.

(Function and effect)
The laminate of the present invention described above includes (poly) alkylene glycol mono (meth) acrylate (A) and N, N-dimethyl (meth) acrylamide (B) as polymerization reactive compounds, ) The proportion of alkylene glycol mono (meth) acrylate (A) is 40 to 95% by mass out of 100% by mass of the polymerization reactive compound, and the proportion of N, N-dimethyl (meth) acrylamide (B) is the polymerization reactive compound. When the set time for forming the surface layer on the surface of the intermediate layer is short because the intermediate layer formed by curing the composition for forming an intermediate layer that is 5 to 60% by mass of 100% by mass (continuously the surface layer) Even in the case of forming a surface), the adhesiveness at the interface between the surface layer and the intermediate layer having the fine concavo-convex structure on the surface and at the interface between the intermediate layer and the substrate is excellent.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.
In the following description, “parts” means “parts by mass” unless otherwise specified.
Various measurements and evaluation methods are as follows.

(1) Measurement of mold pores:
Platinum is deposited on a part of the longitudinal section of the anodized porous alumina on the surface of the mold for 1 minute, and then the longitudinal section at an acceleration voltage of 3.00 kV using a field emission scanning electron microscope (JSM-7400F, manufactured by JEOL Ltd.) Was observed, and the interval between adjacent pores and the depth of the pores were measured. Specifically, 10 points were measured for each, and the average value was taken as the measured value.

(2) Measurement of unevenness of fine uneven structure:
Platinum was vapor-deposited for 10 minutes on the vertical cross section of the fine concavo-convex structure on the surface of the laminate, and the spacing between adjacent convex portions or concave portions and the height of the convex portions were measured using the same apparatus and conditions as in (1). Specifically, 10 points were measured for each, and the average value was taken as the measured value.

(3) Evaluation of adhesion:
In accordance with JIS K 5400, a cross-cut peel test was performed on the surface layer of the laminate to evaluate adhesion. An acrylic plate having a thickness of 2 mm was used as the base. The grid was made with 100 squares of 10 × 10, and the number where peeling did not occur in 100 squares was evaluated. “◎” for 100/100 squares that were not peeled, “◯” for 50-99 / 100, “△” for 1-49, 0/100 Was marked “x”.

(4) Evaluation of transparency:
When the intermediate layer was visually observed, “h” was given when there was no haze (white, poor transparency), and “x” was given.

(Mold production)
An aluminum plate having a purity of 99.99% was polished with a blanket and then electropolished in a perchloric acid / ethanol mixed solution (1/4 volume ratio) to form a mirror surface.
Step (a):
The mirror-finished aluminum plate was anodized in a 0.3 M oxalic acid aqueous solution at a direct current of 40 V and a temperature of 16 ° C. for 30 minutes to form an oxide film.
Step (b):
The aluminum plate 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.
Step (c):
The aluminum plate from which the oxide film was removed was subjected to anodic oxidation for 30 seconds in a 0.3 M oxalic acid aqueous solution at a direct current of 40 V and a temperature of 16 ° C. to form an oxide film.

Step (d):
The aluminum plate on which the oxide film was formed was immersed in 5% by mass phosphoric acid at 32 ° C. for 8 minutes to carry out pore diameter expansion treatment.
Step (e):
The aluminum plate subjected to the pore diameter expansion treatment was anodized for 30 seconds in a 0.3 M oxalic acid aqueous solution under conditions of a direct current of 40 V and a temperature of 16 ° C. to further form an oxide film.
Step (f):
Steps (d) and (e) are repeated a total of four times, and finally step (d) is performed to form anodized porous alumina having substantially conical pores with an interval of 100 nm and a depth of 180 nm on the surface. A mold was obtained.

  The resulting mold is washed with deionized water, and then water on the surface is removed by air blow, and a fluorinated release material (Optool DSX, manufactured by Daikin Industries, Ltd.) is diluted to a solid content of 0.1% by mass. It was immersed for 10 minutes in a solution diluted with (Harves, HD-ZV) and air-dried for 20 hours.

(Preparation of surface layer forming composition)
25 parts of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-DPH)
25 parts of pentaerythritol triacrylate (Daiichi Kogyo Seiyaku, PET-3),
25 parts of ethylene oxide-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPEA-12),
25 parts of polyethylene glycol diacrylate (manufactured by Shin-Nakamura Chemical, A-600)
1 part of 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Geigy, IRG.184),
0.5 part of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by Ciba-Geigy, IRG.819)
0.1 parts of polyoxyethylene alkyl (12-15) ether phosphoric acid (Nikkol TDP-2, manufactured by Nippon Chemicals Co., Ltd.) was mixed to obtain a composition for forming a surface layer having a viscosity at 25 ° C. of 410 mPa · s.

[Example 1]
(Preparation of intermediate layer forming composition)
60 parts of polypropylene glycol monoacrylate (manufactured by NOF Corporation, Blemmer AP-400 (m≈6), number average molecular weight 400),
25 parts of N, N-dimethylacrylamide (manufactured by Kojinsha, DMAA),
15 parts of 2-hydroxyethyl acrylate (manufactured by Osaka Organic Chemical Industry, HEA),
233 parts of methyl ethyl ketone (manufactured by Wako Pure Chemical Industries, MEK)
1.5 parts of 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba-Geigy, IRG.184),
Mixing 1.5 parts of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Darocur TPO, manufactured by Ciba-Geigy, Japan), a composition for forming an intermediate layer having a viscosity of 10 mPa · s at 25 ° C. Obtained.

(Formation of intermediate layer)
As a substrate, a triacetylcellulose film (Fuji Film, FTT40UZ, thickness 40 μm) was prepared.
The composition for forming an intermediate layer was uniformly applied to the surface of the substrate using a bar coater, and allowed to stand in a dryer at 70 ° C. for 5 minutes. Next, the coating layer is cured by irradiating ultraviolet rays with an integrated light amount of 5000 mJ / cm ² using a high pressure mercury lamp in an atmosphere having an oxygen concentration of 0.1% or less from the side on which the composition for forming an intermediate layer is applied. Formed. The thickness of the intermediate layer was 10 μm.

(Formation of surface layer)
The surface-forming composition was poured onto the surface of the mold on the anodized porous alumina side, and the base material was spread and spread over 15 seconds so that the intermediate layer was in contact therewith. The composition for forming the surface layer was cured by irradiating ultraviolet rays with an integrated light quantity of 1000 mJ / cm ² using a high-pressure mercury lamp from the substrate side. Thereafter, the mold was peeled off to obtain a laminate in which a surface layer having a fine uneven structure on the surface and having a thickness of 10 μm was formed on the surface of the substrate.

  The fine concavo-convex structure of the mold is transferred to the surface of the laminate, and as shown in FIG. 1, a substantially conical shape in which the interval i between the adjacent convex portions 3 is 100 nm and the height h of the convex portions 3 is 180 nm. A fine concavo-convex structure composed of the convex portions 3 was formed. The adhesion and transparency of the surface layer of the obtained laminate were evaluated. The results are shown in Table 1.

[Examples 2 to 9, Comparative Examples 1 to 6]
A laminate was obtained in the same manner as in Example 1 except that the composition of the polymerizable compound in the intermediate layer forming composition was changed as shown in Table 1. The evaluation results are shown in Table 1.

Abbreviations in the table are as follows.
AP-400: Polypropylene glycol monoacrylate (manufactured by NOF Corporation, Bremer AP-400 (m≈6), number average molecular weight 400),
AP-550: Polypropylene glycol monoacrylate (manufactured by NOF Corporation, Bremer AP-550 (m≈9), number average molecular weight 550),
AP-800: Polypropylene glycol monoacrylate (manufactured by NOF Corporation, Bremer AP-800 (m≈13), number average molecular weight 800),
AE-400: Polyethylene glycol monoacrylate (manufactured by NOF Corporation, Bremer AE-400 (m≈10), number average molecular weight 400),
DMAA: N, N-dimethylacrylamide (manufactured by Kojinsha, DMAA),
HEAA: N- (2-hydroxyethyl) acrylamide (manufactured by Kojin Co., HEAA),
HEA: 2-hydroxyethyl acrylate (manufactured by Osaka Organic Chemical Industry, HEA).

  The laminate of the present invention provides antireflection performance and water repellency performance to building materials (walls, roofs, etc.), window materials (houses, automobiles, trains, ships, etc.), mirrors, and displays that can be touched by human hands. And is extremely useful industrially.

DESCRIPTION OF SYMBOLS 1 Laminate 2 Base material 3 Convex part 4 Surface layer 5 Intermediate layer 6 Concave part 7 Vertex 8 Bottom point i Interval h Height

Claims (2)

A substrate;
A surface layer having a fine relief structure on the surface;
An intermediate layer provided between the base material and the surface layer,
The laminate, wherein the intermediate layer is a layer obtained by curing the following intermediate layer forming composition.
(Composition for intermediate layer formation)
An intermediate layer forming composition containing a polymerization reactive compound,
The polymerization reactive compound includes (poly) alkylene glycol mono (meth) acrylate (A) represented by the following formula (1) and N, N-dimethyl (meth) acrylamide (B):
The proportion of the (poly) alkylene glycol mono (meth) acrylate (A) is 40 to 95% by mass in 100% by mass of the polymerization reactive compound,
The ratio of the N, N-dimethyl (meth) acrylamide (B) is 5 to 60% by mass in 100% by mass of the polymerization reactive compound.
^{_{CH 2 = CR 1 -C (O}} ) O- (AO) m -R 2 ··· (1).
However, the average value of m is 1 or more, A is an alkylene group, R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom, an alkyl group or an aryl group, and is represented by (AO) _m At least one (C ₃ H ₆ O) is included in the structure.   The laminate according to claim 1, wherein the intermediate layer has a thickness of 1 to 40 μm.

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