JP5810591B2 - Laminated body, antireflection article and water repellent article - Google Patents

Description

  The present invention relates to a laminate having a nano uneven structure on the surface, and an antireflection article and a water-repellent article provided with the same.

  A layered product with a surface layer having a nano-concave structure on the surface exhibits antireflection performance by the refractive index continuously changing from the refractive index of air to the refractive index of the material of the surface layer in the nano-concave structure. It is known. The laminate can also exhibit super water-repellent performance due to the lotus effect due to the nano uneven structure.

  In order for the laminate to exhibit good antireflection performance, it is necessary that the spacing between adjacent convex portions or concave portions in the nano-concave structure is not more than the wavelength of visible light. However, the surface layer having such a nano uneven structure is inferior in scratch resistance compared to a smooth hard coat layer formed using the same active energy ray-curable resin composition, and there is a problem in durability during use. There is.

As a method for improving the scratch resistance of the hard coat layer, a method of including a silicone oil in the hard coat layer has been proposed (Patent Document 1).
In order to achieve both scratch resistance and impact resistance, a method using a (meth) acrylic resin in which rubber particles are dispersed in a base material on which a hard coat layer is formed has been proposed (Patent Document 2). .

  However, although the methods described in Patent Documents 1 and 2 can improve the scratch resistance to some extent, they are not always sufficient. For example, the antireflection performance may be impaired due to bending or bending of the fine protrusions constituting the nano uneven structure of the surface layer. Therefore, the use of the laminated body which has a nano uneven structure on the surface will be limited.

JP 2000-234073 A JP 2007-030307 A

  The present invention provides a laminate exhibiting high scratch resistance despite having a nano uneven structure on the surface, and an antireflection article and a water-repellent article provided with the laminate.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a laminate having a specific configuration exhibits a very excellent effect, and have completed the present invention.
That is, the laminate of the present invention comprises a light-transmitting base material comprising a cured product of a (meth) acrylate-based active energy ray-curable resin , and convex or concave portions laminated on the light-transmitting base material . A laminate having a surface with a nano-concave structure having an average interval of 380 nm or less on the surface, and the tan δ (loss tangent) of the light-transmitting substrate is 0.15 or more at 20 ° C. and 1 Hz It is characterized by.

Before Symbol surface layer is preferably made of (meth) acrylate resin.
The antireflection article of the present invention is characterized by comprising the laminate of the present invention.
The water-repellent article of the present invention is characterized by comprising the laminate of the present invention.

  The laminate of the present invention and the antireflection article and water-repellent article provided with the laminate exhibit high scratch resistance despite having a nano-concave structure on the surface.

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.

In this specification, the nano uneven structure means a structure in which the average interval (period) between the convex portions or the concave portions is equal to or less than the wavelength of visible light, that is, 380 nm or less.
Moreover, light transmittance means transmitting light.
Active energy rays mean visible rays, ultraviolet rays, electron beams, plasma, heat rays (infrared rays, etc.), X rays, α rays, β rays, γ rays and the like.
Visible light means light having a wavelength of 380 to 780 nm.
(Meth) acrylate means acrylate or methacrylate.

<Laminate>
The laminate of the present invention has a light-transmitting substrate and a surface layer having a nano uneven structure on the surface, which is stacked on at least one surface of the light-transmitting substrate.
1 and 2 are cross-sectional views showing an example of the laminate of the present invention. The laminate 10 includes a light transmissive substrate 11 and a surface layer 12 that is laminated on the light transmissive substrate 11 and has a nano uneven structure on the surface.

(Light transmissive substrate)
The light transmissive substrate 11 is a molded body that transmits light.
The tan δ (loss tangent) of the light-transmitting substrate 11 is 0.15 or more at 20 ° C. and 1 Hz, and preferably 0.4 or more. If tan δ is 0.15 or more, energy such as friction on the surface of the laminate 10 can be dispersed well, and scratches on the surface layer 12 can be reduced (improved scratch resistance). The tan δ is preferably 2 or less from the viewpoint of the balance between the storage elastic modulus and the loss elastic modulus capable of obtaining good scratch resistance.

  tan δ is a value obtained by dividing the storage elastic modulus by the loss elastic modulus, and is obtained by dynamic viscoelasticity measurement. Specifically, with respect to a test piece obtained by punching a light-transmitting substrate having a thickness of 200 μm into a strip shape having a width of 5 mm, a commercially available viscoelasticity measuring device was used, and a tensile mode, an interval between chucks: 2 cm, and a measurement frequency: 1 Hz Then, the temperature is measured from −50 ° C. to 100 ° C. at a rate of temperature increase of 2 ° C./min, tan δ is obtained, and the value of tan δ at 20 ° C. is used for judgment.

  The material of the light transmissive substrate 11 may be any material that allows the tan δ of the light transmissive substrate 11 to be 0.15 or more at 20 ° C. and 1 Hz. Examples of the material of the light-transmitting substrate 11 include (meth) acrylate resin, polycarbonate, styrene (co) polymer, (meth) acrylate-styrene copolymer, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, and polyester. (Polyethylene terephthalate, polylactic acid, etc.), polyamide, polyimide, polyether sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polyurethane, and composites thereof (with polymethyl methacrylate) And a compound of polylactic acid, a compound of polymethyl methacrylate and polyvinyl chloride, etc.), glass and the like.

  As a material of the light transmissive substrate 11, a (meth) acrylate-based resin is preferable from the viewpoint of transparency, and a material having a tan δ of 0.15 or more can be easily designed. A cured product of the active energy ray-curable resin composition is more preferable.

The light transmissive substrate 11 may be any of a plate shape, a sheet shape, and a film shape.
The surface of the light-transmitting substrate 11 may be subjected to coating, corona treatment, etc. for the purpose of improving properties such as adhesion, antistatic properties, scratch resistance, and weather resistance.
The thickness of the light transmissive substrate 11 is not particularly limited. In addition, from the viewpoint of productivity and handling in the step of providing the surface layer 12, the light-transmitting substrate 11 is preferably a bendable film, and more preferably has a thickness of 5 μm to 500 μm.

(Surface)
As shown in FIGS. 1 and 2, the surface of the surface layer 12 has a nano uneven structure that exhibits antireflection performance and super-water-repellent performance. Specifically, convex portions 13 and concave portions 14 are formed at equal intervals on the surface of the surface layer 12. The shape of the convex portion 13 in FIG. 1 is a conical shape or a pyramid shape, and the shape of the convex portion 13 in FIG. 2 is a bell shape. In addition, the shape of the convex part 13 of a nano uneven | corrugated structure is not limited to these, but the cross-sectional area of the convex part 13 of the direction orthogonal to a height direction seems to increase continuously or intermittently from the outermost surface to the depth direction. It is preferable to use a simple shape. A plurality of finer projections may be combined to form one convex portion 13. That is, even if the shape is other than the convex portion 13 in FIGS. 1 and 2, the refractive index increases continuously or intermittently from the refractive index of air to the refractive index of the material of the surface layer 12, and the low reflectance and low Any shape that exhibits antireflection performance that achieves both wavelength dependence and the like may be used.

  The interval between the adjacent convex portions 13 (in FIG. 1, the interval w1 between the center points (vertices 13a) of the adjacent convex portions 13) or the interval between the adjacent concave portions 14 is to exhibit good antireflection performance. Needs to be shorter than the wavelength of visible light, that is, 380 nm or less. If w1 is 380 nm or less, the scattering of visible light can be suppressed. Therefore, the laminate 10 can be suitably used for optical applications such as antireflection articles.

  The height of the convex portion 13 or the depth of the concave portion 14 (in FIG. 1, the vertical distance d1 from the central point (bottom point 14a) of the concave portion 14 to the central point (vertex 13a) of the convex portion is the lowest reflection. 60 nm or more is preferable and 90 nm or more is more preferable from the point which suppresses the raise of the rate and the reflectance of a specific wavelength. Moreover, the upper limit of the height of the convex part 13 or the depth of the recessed part 14 should just be the range which can be manufactured, and is not restrict | limited in particular. When the nano uneven structure of the surface layer 12 is formed by a method of transferring the nano uneven structure of the mold using a mold, the height of the convex portion 13 or the depth of the concave portion 14 is 2 μm for accurate transfer. It is preferable that it is less than.

In the nano concavo-convex structure, the aspect ratio (d1 / w1) represented by the height / interval of the protrusions 13 is preferably 0.5 or more, more preferably 1 or more, and most preferably 2 or more. When the aspect ratio is 0.5 or more, the effect of reducing light reflection can be obtained satisfactorily, and the incident angle dependency can be reduced. The upper limit of the aspect ratio is not particularly limited as long as it can be produced. When forming the nano uneven structure of the surface layer 12 by a method using a mold and transferring the nano uneven structure of the mold, the aspect ratio of the convex portion 13 is preferably 5 or less in order to transfer accurately. .
The shape of the nano concavo-convex structure that exhibits good antireflection performance is described in Japanese Patent Application Laid-Open No. 2009-031764, and the same shape can be adopted in the present invention.

  The material of the surface layer 12 is preferably a (meth) acrylate-based resin from the viewpoint of transparency, and an active energy ray-curable resin composition for forming a surface layer, which will be described later, from the viewpoint of easily forming the surface layer 12 with good scratch resistance. The cured product is more preferable.

  5-30 micrometers is preferable and, as for the thickness of the surface layer 12, 8-20 micrometers is more preferable. If the surface layer 12 is moderately thin, the curing of the active energy ray-curable resin composition for forming a surface layer, which will be described later, with normal ultraviolet irradiation proceeds sufficiently, and good scratch resistance is obtained. If the surface layer 12 is moderately thick, breakage of the surface layer 12 can be suppressed.

  When the surface layer 12 is made of a cured product of an active energy ray-curable resin composition for forming a surface layer, which will be described later, in order to satisfactorily form a nano uneven structure on the surface layer 12, the cured product has a high crosslinking density, high elasticity and It is preferable to do. With a cured product having a high crosslinking density, it is difficult to obtain a tensile elongation, and the tensile elongation at break is 5% or less. For this reason, if the surface layer 12 is too thin, the surface layer 12 will be tensile-ruptured when a load is applied to the laminate 10, and the crack will remain as a scratch that can be visually confirmed. On the other hand, if the surface layer 12 is too thick, the stress applied to the laminate 10 is not well dispersed by the light-transmitting substrate 11, and the surface layer 12 is damaged.

  In order for the surface layer 12 to satisfactorily follow the deformation of the light-transmitting substrate 11, it is preferable that the light-transmitting substrate 11 and the surface layer 12 are sufficiently adhered. Further, if the light-transmitting base material 11 and the surface layer 12 are sufficiently adhered, interfacial peeling due to shear deformation is unlikely to occur. It is preferable that the light-transmitting substrate 11 and the surface layer 12 are in a mixed state in which no clear interface exists. By making the surface of the light transmissive substrate 11 insufficiently cured or by allowing the active energy ray-curable resin composition for forming the surface layer 12 constituting the surface layer 12 to penetrate into the light transmissive substrate 11, a clear interface is obtained. Good adhesion can be obtained without the presence of. In addition, the thickness of the light-transmitting base material 11 and the surface layer 12 when there is no clear interface is measured using the intermediate position of the mixed portion between the light-transmitting base material 11 and the surface layer 12 as an interface. Further, the adhesion can be improved by applying heat when forming the surface layer 12.

(Function and effect)
In the laminated body 10 described above, the tan δ (loss tangent) of the light-transmitting substrate 11 is 0.15 or more at 20 ° C. and 1 Hz, so that the energy such as friction on the surface of the laminated body 10 can be improved. It can disperse | distribute and the damage of the surface layer 12 can be reduced. Therefore, although it has a nano uneven structure on the surface, it exhibits high scratch resistance.

<Method for producing laminate>
The laminated body 10 can be manufactured, for example, by a method having the following steps (I) to (II).
(I) A step of manufacturing the light transmissive substrate 11.
(II) A step of forming the surface layer 12 on the light transmissive substrate 11.

[Step (I)]
The manufacturing method of the light transmissive substrate 11 is not particularly limited. Examples of the method for producing the light transmissive substrate 11 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 dry curing method, and an ultraviolet curing method. It is done.

When the light transmissive substrate 11 is a cured product of an active energy ray curable resin composition for forming a light transmissive substrate (hereinafter also referred to as an active energy ray curable resin composition (A)), the light transmissive property is obtained. As a manufacturing method of the base material 11, the following method is mentioned, for example.
A mold corresponding to the shape of the light-transmitting substrate 11 is prepared, and the active energy ray-curable resin composition (A) is sandwiched between the molds through a gasket or the like as necessary, from one side or both sides of the mold. A method of irradiating active energy rays.

Specifically, the following methods (i) and (ii) are exemplified.
(I) A continuous film is used as a mold, the active energy ray-curable resin composition (A) is cast on the film, and another film is laminated thereon to obtain an active energy ray-curable resin composition (A ) Is irradiated with active energy rays, and the sheet is peeled off from the cured product.
(Ii) An active energy ray-curable resin composition (A), which will be described later, is cast on an endless belt, and a film that is transferred in the same direction and at the same speed as the endless belt is overlaid on the endless belt. A method of irradiating the resin composition (A) with active energy rays to continuously peel the film from the cured product and to continuously peel the cured product from the endless belt.

Examples of the film include a polyethylene terephthalate (hereinafter referred to as PET) film. Examples of commercially available PET films include Toyobo Ester Film E5001 (manufactured by Toyobo Co., Ltd.) and Cosmo Shine A4100 (manufactured by Toyobo Co., Ltd.). The thickness of the film is usually 0.01 to 3 mm.
Examples of endless belts include stainless steel plates.

The active energy ray is preferably visible light or ultraviolet light, more preferably ultraviolet light, from the viewpoint of the cost of the apparatus, productivity, and the like. What is necessary is just to determine suitably the irradiation amount of an ultraviolet-ray according to the quantity of the active energy ray polymerization initiator contained in an active energy ray curable resin composition (A). The atmosphere irradiated with ultraviolet rays may be an oxygen-containing atmosphere or a nitrogen atmosphere. The integrated light quantity is preferably 200 to 4000 mJ / cm ² .
When the light-transmitting substrate 11 is continuously manufactured, the light-transmitting substrate 11 can be collected while being wound around a roll such as a paper tube or a plastic core.

(Active energy ray-curable resin composition for forming a light-transmitting substrate)
The active energy ray-curable resin composition (A) is a resin composition that cures by irradiating an active energy ray so that a polymerization reaction proceeds.
The active energy ray-curable resin composition (A) includes a polymerization-reactive monomer component, a polymer component, an active energy ray polymerization initiator, and other components as necessary.

The viscosity of the active energy ray-curable resin composition (A) may be appropriately adjusted optimally according to the production method. For example, when the viscosity is 50 mPa · s or less, it can be uniformly applied by gravure coating. In the case of 200 mPa · s or more, it can be applied to the above-described methods (i) and (ii).
The viscosity of the active energy ray-curable resin composition (A) is a viscosity measured with a rotary B-type viscometer at 25 ° C.

(Polymerization reactive monomer component)
The polymerization reactive monomer component is not particularly limited as long as it can form the light-transmitting substrate 11 made of a cured product by a curing reaction. Examples of the polymerization reactive monomer component include monofunctional (meth) acrylate and polyfunctional (meth) acrylate.

  Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and n-propyl (meth) ) Acrylate, iso-propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate and other alkyl (meth) acrylates; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Hydroxyl group-containing (meth) acrylates such as 2-hydroxy (meth) acrylate and cyclohexanedimethanol mono (meth) acrylate, (meth) acrylamide, dimethyl (meth) acrylamide, N-isopropyl (meth) a Amyl group-containing (meth) acrylates such as rilamide and N-methylol (meth) acrylamide; Carboxyl group-containing (meth) acrylates such as (meth) acrylic acid; Aromatic compounds such as phenyl (meth) acrylate and benzyl (meth) acrylate ( (Meth) acrylate; isobornyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2adamantyl (meth) acrylate, 2-ethyl-2 -Alicyclic (meth) acrylates, such as adamantyl (meth) acrylate, etc. are mentioned. These may be used alone or in combination of two or more. Among these, methyl methacrylate is preferable in terms of transparency.

  Polyfunctional (meth) acrylates include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, nonaethylene glycol, decaethylene glycol, undecaethylene glycol , Dodecaethylene glycol, tridecaethylene glycol, tetradecaethylene glycol, pentadecaethylene glycol, hexadecaethylene glycol; propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, heptapropylene Glycol, octapropylene glycol, Propylene glycol, decapropylene glycol, undecapropylene glycol, dodecapropylene glycol, tridecapropylene glycol; butylene glycol, dibutylene glycol, tributylene glycol, tetrabutylene glycol, pentabylene glycol, hexabutylene glycol, heptabylene glycol, octabutylene Polyalkylene glycol di (meth) acrylate obtained by adding (meth) acrylic acid to a polyalkylene glycol residue such as glycol, nonabutylene glycol, decabutylene glycol, and undecabutylene glycol; polyalkylene glycol, 1,5-pentane Low molecular weight diols such as diol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and adipine Polyester diester obtained by adding (meth) acrylic acid to a polyester diol residue that is a reaction product with an acid component such as dibasic acid such as succinic acid, phthalic acid, hexahydrophthalic acid, terephthalic acid, or its anhydride. (Meth) acrylate; Polycarbonate di (meth) acrylate obtained by adding (meth) acrylic acid to a polycarbonate diol residue, which is a reaction product of polyalkylene glycol, low molecular weight diol and carbonate such as dimethyl carbonate; Pentaerythritol Monomers having a plurality of polymerizable double bonds and hydroxyl groups such as tri (meth) acrylate and dipentaerythritol penta (meth) acrylate; polyfunctional urethane (meth) acrylate, polyfunctional epoxy-modified (meth) acrylate and the like. These may be used alone or in combination of two or more. Among these, polybutylene glycol dimethacrylate is preferable, and nonabutylene glycol dimethacrylate is more preferable from the viewpoint that the tan δ (loss tangent) of the light-transmitting substrate 11 is 0.15 or more at 20 ° C. and 1 Hz.

  As a commercial product of polyfunctional (meth) acrylate, acrylate PBOM (manufactured by Mitsubishi Rayon Co., Ltd.); Blemmer PDE-600, Blemmer PDP-700, Blemmer PDT-650, Blemmer 40PDC1700B, Blemmer ADE-600 (manufactured by NOF Corporation) NK ester A-600, NK ester A-1000, NK ester APG-700, NK ester 14G, NK ester 23G (manufactured by Shin-Nakamura Chemical Co., Ltd.); Ebecryl (registered trademark) series (manufactured by Daicel Cytec); Aronix (Registered trademark) series (manufactured by Toagosei Co., Ltd.); KAYARAD (registered trademark) series (manufactured by Nippon Kayaku Co., Ltd.) and the like.

  By setting the Tg of the cured product of the active energy ray-curable resin composition (A) to around room temperature, tan δ at 20 ° C. and 1 Hz can be set to 0.15 or more. Specifically, the ratio of the polyfunctional (meth) acrylate is preferably 50% by mass or more and 100% by mass or less in the active energy ray-curable resin composition (A) (100% by mass).

(Polymer component)
The polymer component is a component that improves the thickness accuracy of the light-transmitting substrate 11, the operability of the active energy ray-curable resin composition (A), the transparency of the light-transmitting substrate 11, and the like.
The polymer component is not particularly limited as long as it is soluble in the polymerization-reactive monomer component. As the polymer component, for example, a copolymer of monofunctional (meth) acrylate and / or polyfunctional (meth) acrylate; at least one (meth) acrylate selected from monofunctional (meth) acrylate and / or copolymerizable (Co) polymers of various comonomers.

The polymer is produced by a method such as suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization. You may use a polymerization initiator and a chain transfer agent at the time of superposition | polymerization.
Examples of the polymerization initiator include beanzoyl peroxide, lauroyl peroxide, t-butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneodecanoate, t- Organic peroxide polymerization initiators such as hexylperoxypivalate, diisopropylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate; 2,2′-azobisisobutyronitrile, 2, Examples thereof include azo polymerization initiators such as 2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile).
Examples of the chain transfer agent include alkyl mercaptans such as n-butyl mercaptan, n-dodecyl mercaptan, and n-octyl mercaptan; α-methylstyrene dimer.

(Active energy ray polymerization initiator)
The active energy ray polymerization initiator is not particularly limited as long as it is a compound that is cleaved by irradiation with active energy rays and generates a radical that initiates the polymerization reaction of the polymerization reactive monomer component. What is necessary is just to determine suitably the kind and quantity of an active energy ray polymerization initiator according to the atmosphere etc. which irradiate an active energy ray curable resin composition (A), for example.

  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'okisaido, diphenylphosphine oxide, 2-methyl-benzoyl diphenyl phosphine oxide, benzoyl dimethoxy phosphine oxide, and the like. These may be used alone or in combination of two or more.

(solvent)
The active energy ray-curable resin composition (A) 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.
A solvent having an appropriate boiling point may be selected depending on the drying method and the like. Examples of the solvent include alcohols such as toluene, methyl ethyl ketone, cyclohexanone and isopropyl alcohol. These may be used alone or in combination of two or more.

(Other ingredients)
The active energy ray-curable resin composition (A) is optionally 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 aid, It may contain additives such as a polymerization inhibitor, a filler, a silane coupling agent, a colorant, a reinforcing agent, an inorganic filler, an impact modifier, and a near infrared absorber.
Various additives may be added to the surface layer 12 of the laminate 10, but there is a concern that the performance may deteriorate due to bleed-out over time. By adding to the light transmissive substrate 11, bleeding out can be suppressed and prevented.

By adding the antistatic agent, it is possible to obtain the laminate 10 to which dust or the like is difficult to adhere. Examples of the antistatic agent include polythiol-based, polythiophene-based and polyaniline-based conductive polymers, inorganic fine particles such as carbon nanotubes and carbon black, lithium salts exemplified in JP-A-2007-070449, 4 Class ammonium salt etc. are mentioned. These may be used alone or in combination of two or more. Among these, a lithium perfluoroalkyl acid salt that does not impair the transparency of the laminate 10, is relatively inexpensive, and exhibits stable performance is preferable.
The 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 monomer component in the light-transmitting base material. When the amount of the antistatic agent is 0.5 parts by mass or more, the surface resistance value of the laminate 10 is lowered, and the dust adhesion preventing performance is exhibited. If the amount of the antistatic agent is 20 parts by mass or less, the cost of the laminate 10 can be suppressed.

  The heat insulation effect can be provided to the laminated body 10 by adding a near-infrared absorber. Moreover, when used for a plasma display or the like, it is possible to prevent malfunction of the infrared remote controller of various home appliances. Examples of the near infrared absorber include organic near infrared absorbers such as diimonium dyes, phthalocyanine dyes, dithiol metal complex dyes, substituted benzenedithiol metal complex dyes, cyanine dyes, squalium dyes; Inorganic near-infrared absorbers such as conductive antimony-containing tin oxide fine particles, conductive tin-containing indium oxide fine particles, tungsten oxide fine particles, and composite tungsten oxide fine particles. These may be used alone or in combination of two or more.

[Process (II)]
Examples of the method for forming the surface layer 12 include the following methods.
(Α) An active energy ray-curable resin composition for surface layer formation (hereinafter referred to as an active energy ray-curable resin composition (B)) between the mold having an inverted structure of the nano uneven structure and the light-transmitting substrate 11 The active energy ray-curable resin composition (B) is cured by irradiating with active energy rays, and the mold is peeled off from the cured product, thereby forming a nano-concave structure made of the cured product on the surface. Forming the surface layer 12 of
(Β) The active energy ray-curable composition (B) is coated on the light-transmitting substrate 11, the nano-concave structure is transferred to the coating layer by pressing the transfer surface of the mold, and then released. A method of curing the coating layer by energy beam irradiation.

About the formation method of the surface layer 12 which has a nano uneven | corrugated structure on the surface, the manufacturing method of a mold, etc., what is necessary is just to employ | adopt the well-known techniques as described in Unexamined-Japanese-Patent No. 2009-031764 etc., for example.
For example, first, a mold having an inverted structure corresponding to the nano uneven structure of the surface layer 12 is manufactured, and the active energy ray curability in which the nano uneven structure (inverted structure) on the surface of the mold is transferred using the mold. A method of forming a cured product of the resin composition (B) is preferable.

  Examples of the method for forming the nano uneven structure in the mold include a method of forming the nano uneven structure by an electron beam lithography method or a laser beam interference method, and anodizing the surface of aluminum to form anodized porous alumina. As the mold, a mold made of anodized porous alumina is preferable from the viewpoint that the area of the mold can be increased and a roll-shaped mold can be easily produced.

Anodized porous alumina is an anodic oxide film (alumite) of aluminum, and a large number of pores are formed in the oxide film.
Anodized porous alumina can be produced, for example, through the following steps (a) to (e). Steps (a) to (b) can be omitted, but it is preferable to perform the steps in order to improve the regularity of the pores.

(A) A step of forming an oxide film by anodizing 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 aluminum again in an 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 step (c) and the step (d).

  The surface (transfer surface) of the mold made of anodized porous alumina may be treated with a release agent so as to facilitate separation from the cured product. Examples of the treatment method include a method of coating a silicone polymer or a fluorine polymer, a method of depositing a fluorine compound, a method of coating a fluorine silane coupling agent or a fluorine silicone silane coupling agent, and the like.

  Examples of the shape of the mold made of anodized porous alumina include a flat plate shape, a columnar shape, and a cylindrical shape. A columnar or cylindrical mold is obtained by performing the above-described steps using columnar or cylindrical aluminum or a material having an aluminum layer on the surface of a columnar or cylindrical support as a base material. The cylindrical shape can be used as it is, and the cylindrical shape can be used as a roll-shaped mold with a higher productivity by fitting the axis inside.

  Further, a replica can be produced using the anodized porous alumina obtained by the above-described process as a master, and the replica can be used as a mold. As a replica production method, for example, a thin film made of nickel, silver, or the like is formed on a master by electroless plating, sputtering, or the like, and then, for example, nickel is deposited by electroplating (electroforming) using the thin film as an electrode. Then, the nickel layer is peeled off from the mastering substrate to form a replica.

(Active energy ray-curable resin composition for surface layer formation)
The active energy ray-curable resin composition (B) is a resin composition that cures by irradiating an active energy ray so that a polymerization reaction proceeds.
The active energy ray-curable resin composition (B) includes a polymerization reactive monomer component, an active energy ray polymerization initiator, and other components as necessary.

  The viscosity at 25 ° C. of the active energy ray-curable resin composition (B) is preferably 10,000 mPa · s or less, more preferably 5000 mPa · s or less, and more preferably 2000 mPa · s in view of the workability when poured into a mold and cured. Particularly preferred is s or less. Even if the viscosity is 10000 mPa · s or more, if the active energy ray-curable resin composition (B) can be heated in advance when pouring into the mold and the viscosity can be lowered, workability is not impaired. Can be used. The viscosity at 70 ° C. of the active energy ray-curable resin composition (B) is preferably 5000 mPa · s or less, and more preferably 2000 mPa · s or less.

The viscosity at 25 ° C. of the active energy ray-curable resin composition (B) is preferably 100 mPa · s or more in consideration of workability when continuously produced using a belt-shaped or roll-shaped mold. The above is more preferable, and 200 mPa · s or more is particularly preferable. These ranges are meaningful in that it is difficult to leak to the side beyond the width of the mold in the process of pressing the mold, and the thickness of the cured product can be easily adjusted arbitrarily.
The viscosity of the active energy ray-curable resin composition (B) is a viscosity measured with a rotary B-type viscometer at a predetermined temperature.

  The viscosity of the active energy ray-curable resin composition (B) can be adjusted by adjusting the type and amount of the polymerization-reactive monomer component. Specifically, when a large amount of a polymerizable reactive monomer component containing a functional group having a molecular interaction such as a hydrogen bond or a chemical structure is used, the viscosity of the active energy ray-curable resin composition (B) increases. In addition, when a large amount of a low molecular weight polymerization-reactive monomer component having no intermolecular interaction is used, the viscosity of the active energy ray-curable resin composition (B) becomes low.

  Known components can be used as the polymerization reactive monomer component and the active energy ray polymerization initiator. Examples of the polymerization-reactive monomer component include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule. Monofunctional or polyfunctional monomer components having radical polymerizable bonds include various (meth) acrylates and derivatives thereof, and monomer components having cationic polymerizable bonds include epoxy groups, oxetanyl groups, oxazolyl groups, vinyloxy groups, and the like. The monomer which has is mentioned. Examples of the polymerization-reactive monomer component and active energy ray polymerization initiator suitable for forming the surface layer 12 having a nano uneven structure on the surface include various compounds described in paragraph [0018] and subsequent paragraphs of JP-A-2009-031764. Can be adopted.

  The active energy ray-curable resin composition (B) is optionally 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 aid, It may contain additives such as a polymerization inhibitor, a filler, a silane coupling agent, a colorant, a reinforcing agent, an inorganic filler, and an impact modifier.

If the cured product of the active energy ray-curable resin composition (B) is soft, the protrusions 13 of the nano uneven structure may come close to each other when or after the mold is removed from the cured product. In the nano region, even surface tension that does not cause a problem in the macro region works remarkably. That is, in order to lower the surface free energy, a force is applied to make the surface area smaller by closely approaching the protrusions 13 of the nano uneven structure. When this force exceeds the hardness of the cured product, the convex portions 13 are closely attached to each other. In such a nano uneven structure, there are cases where desired antireflection performance, super water repellency performance, and the like cannot be exhibited.
From the above points, the tensile elastic modulus of the cured product is preferably 1 GPa or more. If the active energy ray-curable resin composition (B) capable of forming such a cured product is used, it is easy to avoid the protrusions 13 from snuggling together.

<Application>
The laminate of the present invention is optimal as a functional article having a nano uneven structure on the surface layer. Examples of such functional articles include antireflection articles and water-repellent articles 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.
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.

In the functional article, when the part to which the laminate is pasted is a three-dimensional shape, a light-transmitting substrate having a shape corresponding to that is used in advance, and a surface layer is formed on the light-transmitting substrate to form the laminate. After being obtained, this laminate may be attached to a predetermined part of the functional article.
In addition, when the functional article is an image display device, the laminate of the present invention may be attached to the front plate, not limited to the surface thereof, and the front plate itself is composed of the laminate of the present invention. May be.

(Anti-reflective article)
The antireflection article of the present invention comprises the laminate of the present invention. This antireflection article exhibits high scratch resistance and good antireflection performance. As the antireflection article, for example, an image display device such as a liquid crystal display device, a plasma display panel, an electroluminescence display, and a cathode ray tube display device, a surface of an object such as a lens, a show window, a spectacle lens, etc. One with a body attached is mentioned.

(Water repellent article)
The water-repellent article of the present invention includes the laminate of the present invention. The water-repellent article has high scratch resistance and good water repellency, and exhibits excellent antireflection performance. Examples of the water-repellent article include those in which the laminate of the present invention is attached to the surfaces of window materials, roof tiles, outdoor lighting, curved mirrors, vehicle windows, and vehicle mirrors.

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

(1) Measurement of mold pores:
Platinum is deposited on a longitudinal section of a part of a mold made of anodized porous alumina for 1 minute, and observed at an acceleration voltage of 3.00 kV using a field emission scanning electron microscope (JSM-7400F, manufactured by JEOL Ltd.). The interval (period) 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 nano uneven structure:
Platinum was vapor-deposited on the longitudinal section of the laminate for 10 minutes, and the distance 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) Viscoelasticity measurement of light-transmitting substrate:
The active energy ray-curable resin composition (A) is photocured and formed into a film having a thickness of 200 μm, and this film is punched into a strip shape having a width of 5 mm, and a viscoelasticity measuring device (Seiko Instruments Inc.) is used. Tan δ was determined by using a DMS110), tensile mode, between chucks: 2 cm, measurement frequency: 1 Hz, from −50 to 100 ° C. at a rate of 2 ° C./min.

(4) Evaluation of scratch resistance:
Attach a 1cm square canvas cloth to an abrasion tester (made by Shinto Kagaku Co., Ltd., HEIDON), apply a load of 100 g, reciprocating distance: 50 mm, head speed: 60 mm / s. The surface was scratched 1000 times. Thereafter, the appearance was visually observed and evaluated according to the following criteria.
“◯”: Four or less scratches are confirmed.
“×”: 5 or more scratches are confirmed.

(5) Evaluation of adhesion According to JIS K 5400, a cross-cut peel test was performed 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.

[Production example]
An aluminum plate having a purity of 99.99% was mirror polished by feather polishing and electrolytic polishing in a perchloric acid / ethanol mixed solution (1/4 volume ratio).
Step (a):
This aluminum plate was anodized in a 0.3 M oxalic acid aqueous solution for 30 minutes under the conditions of DC: 40 V and temperature: 16 ° C.
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 anodized in a 0.3 M oxalic acid aqueous solution for 30 seconds under the conditions of DC: 40 V and temperature: 16 ° C.
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):
Step (c) and step (d) were repeated 5 times in total to obtain anodized porous alumina having pores having a substantially conical shape with an average interval of 100 nm and a depth of 180 nm.

  The obtained anodized porous alumina is washed with deionized water, and then water on the surface is removed by air blow so that the fluorine-based release material (Daikin Kogyo Co., Ltd., OPTOOL DSX) has a solid content of 0.1% by mass. Was immersed in a solution diluted with a diluent (HD-ZV, manufactured by Harves Co., Ltd.) for 10 minutes and air-dried for 20 hours to obtain a mold having pores formed on the surface.

[Preparation Example]
80 parts of ethoxylated pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester ATM-4E), 15 parts of silicone diacrylate (manufactured by Shin-Etsu Chemical Co., Ltd., x-22-1602), 2-hydroxyethyl acrylate 5 parts, 0.5 part of 2-hydroxy-2-methyl-1-phenylpropan-1-one (Nippon Ciba Geigy, DAROCURE 1173) as active energy ray polymerization initiator and 2,4,6-trimethylbenzoyl- 0.5 parts of diphenyl-phosphine oxide (manufactured by Ciba Geigy Japan, DAROCURE TPO) was mixed to obtain an active energy ray-curable resin composition (B).

[Example 1]
(Process (I))
In a reactor equipped with a condenser, a thermometer and a stirrer, 20 parts of polybutylene glycol dimethacrylate (manufactured by Mitsubishi Rayon Co., Ltd., acrylate PBOM) (hereinafter referred to as PBOM), methyl methacrylate (hereinafter referred to as MMA) ) And 1 part of n-octyl mercaptan (manufactured by Kanto Chemical Co., Inc.) (hereinafter referred to as n-OM) as a chain transfer agent, and heating was started while stirring.
When the temperature in the reactor reaches 80 ° C., 2,2′-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, V-65) as a polymerization initiator (hereinafter referred to as V- 0.018 parts of 65.) was added.
Next, the temperature in the reactor was raised to 100 ° C. and held for 120 minutes, and then rapidly cooled to room temperature with a large amount of ice water to obtain a polymer component.

  A syrup composition was prepared from 50 parts of the resulting polymer component and 50 parts of PBOM. To 100 parts of the syrup composition, 500 ppm of di (2-ethylhexyl) sodium sulfosuccinate is added as a release agent, and 0.3 part of 1-hydroxy-cyclohexyl-phenyl-ketone is added as an active energy ray polymerization initiator. This was added to obtain an active energy ray-curable resin composition (A). Table 1 shows the blending amounts.

The active energy ray-curable resin composition (A) was cast on a PET film (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) having a thickness of 188 μm, and then cast into the active energy ray-polymerizable composition (A ) Is sandwiched between another PET film and passed under a chemical lamp at 0.13 m / min, and irradiated with light at a peak illuminance of 4.0 mW / cm ² and an integrated light amount of 3700 mJ / cm ^2. Cured. The cured product was peeled from the PET film, heat-treated for 3 minutes in an air furnace at 65 ° C., and thermally polymerized to obtain a light-transmitting substrate having a thickness of 200 μm.

(Process (II))
The active energy ray-curable resin composition (B) was poured onto the surface of the mold on the pore side, and the light transmissive base material was spread and spread thereon. The active energy ray-curable resin composition (B) was cured by irradiating ultraviolet rays at an integrated light amount of 2000 mJ / cm ² using a high-pressure mercury lamp from the light-transmitting substrate side. Then, the mold was peeled from the cured product to obtain a laminate having a nano uneven structure on the surface.

  On the surface of this laminate, the nano-concave structure of the mold is transferred, and as shown in FIG. 1, a substantially cone having an interval w1 between adjacent convex portions 13 of 100 nm and a height d1 of convex portions 13 of 180 nm. A nano-concave structure having a shape was formed. The obtained laminate exhibited high scratch resistance and high adhesion. The results are shown in Table 2.

[Comparative Example 1]
A laminate was obtained in the same manner as in Example 1, except that a PET film (manufactured by Toyobo Co., Ltd., Cosmo Shine A4100) was used as the light transmissive substrate. The results are shown in Table 2.

[Comparative Example 2]
A laminate was obtained in the same manner as in Example 1 except that the blending amounts and polymerization times of PBOM, MMA, n-OM, and V-65 were changed to the blending amounts and times shown in Table 1. The results are shown in Table 2.

  The laminate of the present invention has excellent scratch resistance even when it has a nano uneven structure on the surface, and is used for building materials such as walls and roofs; window materials for houses, automobiles, trains, ships, etc. It can be used for a display that can be touched by human hands, and is extremely useful industrially.

DESCRIPTION OF SYMBOLS 10 Laminate 11 Light-transmitting base material 12 Surface layer 13 Convex part 13a Apex of convex part 14 Concave part 14a Bottom point of concave part w1 Spacing of adjacent convex part d1 Vertical distance from bottom point of concave part to apex of convex part

Claims (4)

A light-transmitting substrate comprising a cured product of a (meth) acrylate-based active energy ray-curable resin ;
A laminate having a nano-concavo-convex structure on the surface and having an average interval of convex portions or concave portions of 380 nm or less laminated on the light-transmitting substrate,
The laminated body whose tan (delta) (loss tangent) of the said light-transmissive base material is 0.15 or more in 20 degreeC and 1 Hz. Before Symbol surface layer, consisting of (meth) acrylate resin laminate of claim 1.   An antireflection article comprising the laminate according to claim 1.   A water repellent article comprising the laminate according to claim 1.

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