JP2000071290A - Manufacture of antireflection article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply forming a more preferable surface shape to obtain high antireflectivity. SOLUTION: In the method for manufacturing an article having antireflectivity by continuously forming a protrusion and recess shape having a pitch of adjacent protrusions or recesses of a range of 10 to 300 nm on at least one surface in a planar direction, the antireflection article is manufactured by using a mold having the protrusion and recess shape and a shape of the relationship between a key and a keyhole on a surface. As the method for manufacturing the article, an injection molding method, a method for transfer forming a layer having the protrusion and recess shape on a base by radiation curing a precursor liquid layer in the state that the base and the mold are laminated via the liquid of the radiation curable resin and then separating the mold or the like is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The anti-reflection article manufactured by the present invention is used in various displays such as a liquid crystal display, a plasma display, a field emission type display, a CRT, a show window, an eyeglass lens, and various optical parts. It is used for the purpose of reducing the amount of light reflection generated at the interface in contact with.

[0002]

2. Description of the Related Art The above-mentioned various displays, show windows and the like have a problem that visibility is reduced due to reflection on the surface by sunlight or indoor illumination light. As a method of reducing such surface reflection, generally, a method of laminating an antireflection film formed by laminating a single layer or several layers of an optical interference film having a different refractive index and a thickness of about 10 to 200 nm is widely used. .

In these methods, in many cases, about two to five layers of light interference films must be laminated in order to obtain excellent antireflection properties, and it takes a long time to manufacture, so that antireflection properties can be more easily obtained. As a method, for example, in JP-A-7-20451, JP-A-7-168006, etc., a coating film in which fine particles having a particle size of a fraction of the wavelength of light are dispersed at a high density using an appropriate binder. On the substrate surface, the refractive index in the in-plane direction (the refractive index in a plane parallel to the plane of vibration of light; hereinafter referred to as the in-plane refractive index) gradually increases from the substrate surface toward the coating film surface side. It has been proposed that a refractive index gradient that decreases is obtained and antireflection properties are obtained.

[0004]

Generally, when two types of substances (A, B) having different refractive indexes are mixed in a size (region) smaller than the wavelength of light, the in-plane of the mixed portion is generally considered. The refractive index takes an intermediate value between the refractive indices of both substances, and the value is roughly determined by the following equation (1) depending on the volume ratio occupied by both substances in a unit volume.

[0005]

## EQU1 ## (1) (where neff is the in-plane refractive index of the mixed portion, na and nb)
Represents the refractive index of each of the substances A and B, and va and vb represent the volume ratio of the substances A and B per unit volume, respectively.)

That is, for example, in the case where an uneven shape is formed such that the pitch of a convex portion or a concave portion adjacent to the surface of an article is smaller than the wavelength of light, the in-plane refractive index of the portion where the unevenness is formed Generally, takes an intermediate value between the refractive index of the convex portion on the article surface and the refractive index of the air (n = 1.0), that is, a value of the refractive index lower than that inside the article, and the antireflection effect is exhibited.

Here, for example, when the cross-sectional shape of the unevenness is rectangular and the surface on which the unevenness is formed is transparent, the difference in height (△ d) between the convex portion and the concave portion and the in-plane of the uneven portion If the unevenness is formed so that the product of the refractive index (neff) is equal to 1/4 of the wavelength of light, a large anti-reflection effect can be obtained for light of this wavelength.

However, when the surface on which the unevenness is formed is opaque, for example, when a metal thin film of aluminum, silver, or the like is laminated on the outermost surface, the above-described phenomenon of a decrease in the refractive index of the unevenness is generally caused. Does not appear. However, in this case, if the unevenness is formed so that the height difference (△ d) between the convex portion and the concave portion is equal to １ ／ of the wavelength of the light, the light reflected by the convex portion and the concave portion will cause mutual interference. By doing so, an antireflection effect can be obtained for light of this wavelength.

In the case where a convex portion is formed such that the volume ratio occupied by the convex portion on the surface of the article becomes smaller toward the front side, the in-plane refractive index gradually increases from the inside to the front side of the article. A decreasing refractive index gradient is exhibited, and the in-plane refractive index changes according to the distance from the outermost surface to the refractive index of air (n = 1.
It has been found that the maximum antireflection effect can be obtained if a gradient of the refractive index can be realized such that a linear linear change from 0) to the refractive index inside the article can be achieved.

Generally speaking, the ideal gradient of the refractive index is such that the ratio of the area occupied by the convex portion in the cut plane obtained by cutting the concave and convex portions in a plane is determined by the linear linearity according to the distance from the outermost surface to the cut plane. It can be realized by forming irregularities that change (linearly increase).

In general, in order to realize high antireflection properties, it is necessary that the area ratio occupied by the projections takes the above-mentioned ideal value or a value slightly lower than the ideal value.

The surface shape meeting this condition is a convex shape such as a polygon, a circle, an ellipse, etc., in which the length of one side or the diameter of the cutting plane is proportional to the square of the distance from the outermost surface. The surface shape in which the shape (or the concave shape) is formed continuously is most preferable. In addition, for example, a convex shape such as a triangular pyramid, a quadrangular pyramid, other polygonal pyramids, and a cone is continuously formed. Surface shape or a surface shape in which hemispherical concave shapes are continuously formed.

In the patent exemplified above, a layer formed by dispersing fine particles having a particle diameter smaller than the wavelength of light at a high density in a binder is coated on a substrate, so that the convex portions formed by the fine particles are coated. The antireflection property is obtained by the refractive index gradient accompanying the decrease in the ratio of the unit volume to the surface side from the base (inside of the article) to the surface side. Therefore, the area ratio occupied by the protrusions in the cutting plane becomes larger than an ideal value, and there is a problem that it is difficult to obtain a high antireflection property.

From these viewpoints, the present invention has been made with the idea of a method of easily forming a more preferable surface shape for obtaining the above-mentioned high antireflection property.

[0015]

According to the method for manufacturing an antireflection article of the present invention, at least one surface has an uneven shape such that the pitch between adjacent convex portions or concave portions is in the range of 10 to 300 nm in a plane direction. A method for producing an article having anti-reflection properties formed continuously, wherein the anti-reflection article is formed by shaping using a mold having a surface having a relationship between the concavo-convex shape and a key and a keyhole on the surface. It is characterized by being manufactured.

Incidentally, the antireflection article of the present invention has a size of about 10%.
It is intended to obtain an antireflection effect for light in a wide wavelength range of about 0 to 750 nm. For this purpose, it is necessary that the pitch of the unevenness on the surface of the article is smaller than the wavelength of the light for which the antireflection effect is to be obtained. It is more preferred that: Also, if the depth of the unevenness (the difference between the height of the concave portion and the height of the convex portion) is in a range from about 1/6 of the wavelength of the light for which the antireflection effect is desired to be obtained to a wavelength equivalent to the wavelength, a high antireflection effect is obtained. . Accordingly, an appropriate value is selected for the range of the pitch of the unevenness on the article surface (10 to 300 nm) according to the wavelength or wavelength range of the target light.

The thickness of the antireflection article of the present invention is not particularly limited, but may be about 20 μm to 1 cm.
A range of degrees is most appropriate.

Here, the method of shaping the unevenness on the surface of the article includes a method of integrally forming the unevenness by injection molding using a mold, and a method of laminating the base and the mold via a precursor liquid layer of a radiation-curable resin. After that, a method of irradiating radiation to cure the precursor liquid layer and then peeling the mold to obtain an article having a radiation-curable resin layer having irregularities laminated on the surface is preferably used.

As the material of the article of the present invention, various materials such as various glasses, resin materials, and metal materials can be widely used depending on the application. Depending on the application, the material does not always need to be highly transparent. As the resin material preferably used here, for example, a thermoplastic resin such as polymethyl methacrylate, triacetyl cellulose, polyethylene terephthalate, and polycarbonate is preferably used. It is preferable to use a resin having good moldability and transferability. For example, polycarbonate, polymethyl methacrylate and the like are preferably used.

The uneven shape used as a mold in the present invention is prepared, for example, by the following method. One method is a preparation method using photolithography technology. For example, after coating a suitable photoresist film on a suitable supporting substrate (glass, metal, etc.), an ultraviolet laser, an electron beam, an X-ray, etc. A pattern having a concavo-convex pattern can be created by selectively irradiating light to form a pattern latent image and developing it. As a method of pattern formation by selective irradiation here, for example, a method of irradiating light only to a selected portion of the substrate by scanning the substrate while intermittently irradiating the light, A method of exposing a fine pattern by reducing and projecting the mask pattern thus formed onto a substrate at a rate of about 1/4 to 1/5 using a stepper (reducing exposure apparatus).

When such photolithography is used, an uneven shape having a rectangular cross section is most basically formed. However, the light sensitivity of the photoresist film used here and the focus of light used for exposure are determined. Alternatively, by appropriately adjusting the depth of focus, for example, an uneven shape having a trapezoidal cross section or a substantially semicircular cross section may be created.

When an ultraviolet laser is used as the light used for the exposure, for example, ArF (wavelength 193n) is used.
m), KrF (wavelength 248 nm), XeCl (wavelength 30
Excimer laser with a compound such as 8 nm) is preferably used. If necessary, these lights are irradiated through a reduction optical system such as a condenser lens to obtain a 300 nm light.
Fine patterning with a pitch of nm or less is possible.

The photoresist layer having the concavo-convex pattern formed as described above can be used as it is as a mold. However, in some cases, the support substrate is dry-etched through the photoresist layer to load the resist. It is also possible to form an uneven pattern on the surface of the support substrate itself by selectively etching the unsupported support substrate surface and finally completely removing the resist layer.

In addition to the above-described method using photolithography, a specific crystal is utilized by utilizing a difference in an etching rate at each crystal lattice plane when a metal or a metal oxide is etched by a chemical solution or plasma. By selectively etching the lattice plane or by treating polyethylene terephthalate with a solvent such as hexafluoroisopropyl alcohol, a large number of polygonal pyramids (quadrangular pyramids, triangular pyramids, cones, etc.) are formed on these surfaces. In some cases, a convex part can be formed.

Further, for example, a polycrystalline film is formed on a metal film such as aluminum by using a vacuum process (sputtering, CVD, etc.), and the substrate temperature during film formation is increased so that the crystal is intentionally grown large. When it is possible to continuously form a shape in which polygonal pyramid-shaped protrusions protrude on the surface of the film by using a method such as appropriately adjusting the deposition rate and the deposition rate, or laser annealing the deposited film. There is.

In some cases, it is possible to form a large number of fine recesses on the surface of aluminum oxide by an electrochemical method such as anodic oxidation.

In some cases, the concave-convex shaped article (master) formed by these methods can be used as a mold as it is, but a replica of the master can be used according to the mechanical strength or thermal strength of the mold. It can be created and used as a mold. As a method of forming a replica, for example, a thin film having a thickness of about 20 to 80 nm made of nickel, silver, or the like is formed on a master by electroless plating, sputtering, or the like, and then the thin film is used as an electrode by electroplating (electroforming). For example, after nickel is deposited to a thickness of about 0.3 mm by a method) or the like, the nickel layer is peeled off from the mastering substrate, thereby forming a replica of the master and having excellent mechanical strength and heat resistance. Can be obtained.

Further, as a method for preparing a mold having a finer concavo-convex pattern which can be prepared more easily than these methods, a coating liquid in which spherical fine particles having an average particle diameter of about 10 to 300 nm are dispersed in a solvent on a suitable supporting substrate is used. To obtain a mold in which fine hemispherical projections are continuously formed on the surface by a method of coating and thermally drying a coating liquid mixed with a material serving as a binder between fine particles and a surfactant, and the like. Can be.

Here, the spherical fine particles may be stacked in several layers in the film thickness direction to form a multi-layer arrangement or a single layer arrangement, but at least on the outermost surface of each fine particle. Are preferably arranged two-dimensionally in a state close to the closest packing. Such an arrangement state of the fine particles is often obtained only by coating a solvent dispersion of the fine particles and heat-treating as described above. However, when it is desired to further increase the filling degree, the fine particles and the solvent or the binder or the interface are required. It is necessary to appropriately set the type of activator, mixing ratio, heat treatment conditions, and the like.

As the support base of the mold, molded bodies of various metals, ceramics, and polymer resins can be preferably used. However, the heat treatment temperature for forming the fine particle dispersed layer, the molding using the mold, and the like. Is selected according to a molding method or the like at the time of performing. Here, it is more preferable to use a steel belt made of stainless steel or the like, a film made of various thermoplastic polymers or the like, a metal roll, a ceramic roll, or the like as a support base of the mold, since these molds can be used for continuous roll-to-roll molding.

As the spherical fine particles, various commercially available silica beads, plastic beads such as polystyrene and polymethyl methacrylate, and the like can be used.

As the solvent, those which can disperse these fine particles well in a liquid are preferable. For example, ethyl alcohol, isopropyl alcohol, normal propyl alcohol, isobutyl alcohol, normal butyl alcohol, tert-butyl alcohol, and 1 methoxy-2-propyl Various alcohols such as alcohols are preferably used.

As the binder, for example, an alkoxysilane such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, dimethylmethoxysilane or a mixture thereof is mixed with an acidic aqueous solution. Hydrolyzed to a partial condensate, epoxy,
Melamine, urethane, alkyd, unsaturated polyester,
A thermosetting resin such as urea is preferably used as a main component.

As the surfactant, various commercially available silicone oils, fluorine-based surfactants and the like are preferably used.

The coating liquid obtained by dispersing the fine particles in these solvents can be formed into a rigid form by a method such as microgravure coating or Meyer bar coating when the supporting base of the mold is a roll-shaped film. When it is a body, it is preferably coated by a method such as spin coating or spray coating.

In order to enhance the adhesion between the fine particle dispersion layer and the supporting substrate, an appropriate primer layer may be previously laminated on the supporting substrate, if necessary.

As such a primer layer, for example, an organic layer composed of an alkoxysilane having an amino group such as N-β (aminoethyl) γ-aminopropyltrimethoxysilane, various kinds of alkoxytitanium, alkoxyzirconium or polymethylmethacrylate, etc. Alternatively, a layer of silicon oxide, titanium oxide, titanium, or ITO formed by a vacuum process such as sputtering or vacuum deposition is preferably used, and is usually formed to a thickness of about 1 to 1000 nm.

Incidentally, the mold using the fine particle dispersed film may be inferior in heat resistance and may not be able to withstand the mold temperature in injection molding. Therefore, in this case, first, the surface shape of this mold is transferred to a radiation-curable resin layer laminated on an appropriate support substrate to obtain a replica (A) in which hemispherical concave portions are continuously formed, and this replica (A) is obtained. When a replica (B) made of metal (made of nickel) is further formed by the same electroplating method as described above, the replica (B) has the same pattern of concavo-convex shape as the above-mentioned fine particle dispersion film. It can be used as a mold having much higher heat resistance than that.

As described above, as a method of transferring and forming an uneven shape on the surface of an article by using these molds, the uneven shape is integrally formed by setting the mold in a mold of a general injection molding machine. Irregularities on the surface are obtained by obtaining the article, or by laminating the substrate and the mold through the precursor liquid of the radiation-curable resin and then irradiating the substrate side or through the mold with radiation to cure the precursor liquid and separating the mold. For example, a method of obtaining an article having a radiation-curable resin layer laminated thereon is preferably used.

The radiation-curable resin refers to a resin in which the crosslinking of the resin proceeds by irradiation with ultraviolet rays, electron beams, or the like. Among them, the use of a highly crosslinkable (meth) acrylate having many functional groups is preferable. Examples of these include (meth) acrylate monomers such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dimethylol tricyclodecane di (meth) acrylate. Or (meth) acrylate oligomers such as urethane (meth) acrylate oligomers, polyester (meth) acrylate oligomers, epoxy (meth) acrylate oligomers having two or more (meth) acryloyl groups in the unit structure, or mixtures thereof Is mentioned.

When the resin is irradiated with ultraviolet rays to promote crosslinking, an appropriate amount of a photoreaction initiator is added. Such photoreaction initiators include, for example, diethoxyacetophenone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane, 2-hydroxy-2
Acetophenone compounds such as 1-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, benzoin compounds such as benzoin and benzyldimethyl ketal, benzophenone compounds such as benzophenone and benzoylbenzoic acid, thioxanthone,
And thioxanthone compounds such as 2,4 dichlorothioxanthone.

As a method for coating these radiation-curable resins, usually, various methods such as spin coating and knife coating can be preferably used.

When coating on a flexible film, various methods such as micro gravure coat, Meyer bar coat, die coat and the like can be used.
Continuous processing by roll-to-roll becomes possible.

It is more preferable that the precursor solution of the radiation curable resin is coated without a solvent. However, when the viscosity of the precursor solution is extremely high, it may be better to dilute the solvent. In this case, before laminating the substrate and the mold via the precursor liquid layer, it is necessary to sufficiently dry the liquid surface and volatilize the contained solvent.

In addition, a transparent thin film of silicon dioxide or the like may be sputtered on the surface of the article having the unevenness produced by the method of the present invention described above in order to increase the mechanical strength of the surface. Lamination is preferably performed by a method such as vacuum deposition, and in some cases, it is preferable to perform an anti-contamination treatment to make the adhered dirt such as fingerprints on the surface less noticeable or to easily wipe off dirt. As a specific method of the anti-contamination treatment, the film thickness is several n.
It is preferable to perform a process of providing an extremely thin layer having excellent oil repellency of not more than m on the surface. Examples of such a layer include various surfactants and CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ —SiCl _3. ,
CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ —SiCH ₃ Cl ₂ , CF
_{3 (CF 2) CH 2 CH} 2 -Si- (OCH 3) 3 various fluoroalkyl silanes such as, fluoroalkoxy silane and materials these were other polymeric materials and copolymerised is preferably used. As a coating method of these layers, a method such as microgravure coating or a Meyer bar coating is preferable when the supporting substrate is a roll-shaped film, and when the supporting substrate is a rigid molded body, Methods such as spin coating and spray coating are preferred.

[0046]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In the present embodiment, light in the visible wavelength range (about 400
(Wavelength range from 700 nm to 700 nm) is an object of antireflection, but the antireflection article produced by the present invention is not necessarily limited to the visible wavelength range, and the unevenness is formed at a smaller pitch than in this embodiment. For example, it is possible to obtain an antireflection effect even for ultraviolet rays in a wavelength range of about 100 to 400 nm.

Example 1 First, a film-shaped mold (hereinafter referred to as a mold film) was prepared. 7 thickness as supporting substrate
Using a 5 μm PET film (HSL-75 manufactured by Teijin), a solvent in which tetrabutoxy titanate (B-4 manufactured by Nippon Soda) is mixed as a primer layer on one side with ligroin and normal butyl alcohol at a weight ratio of 3: 1. And then roll-coated with microgravure and dried at 130 ° C. for 1 minute to a film thickness of 30 nm.
A crosslinked layer of about a certain degree of alkoxy titanium was formed.

Next, a layer in which spherical fine particles were arranged adjacent to each other was laminated on the primer layer. Average particle size of about 1 as spherical fine particles
Using a 60 nm ethyl alcohol-dispersed organosilica sol (manufactured by Catalyst Chemicals Co., Ltd.), a mixture obtained by mixing methyltrimethoxysilane and dimethyltrimethoxysilane at a weight ratio of 4: 1 and then hydrolyzing with dilute hydrochloric acid was used. After mixing at a reduced weight ratio of about 2: 1, the mixture was diluted with normal propanol, roll-coated with microgravure, and heat-treated at 130 ° C. for 3 minutes.

When the surface of the layer thus formed was observed with a scanning electron microscope, it was observed that the silica fine particles were arranged at very high density adjacently with the hemispherical portion almost exposed to air. Was.

Next, by using the following steps,
m polycarbonate film (Pure Ace C manufactured by Teijin)
110), a cured layer of an ultraviolet curable resin having a thickness of about 5 μm obtained by transferring the mold shape of the mold film was formed on one surface.

As a UV-curable resin, trimethylolpropane triacrylate (M309, manufactured by Toa Gosei Chemical Co., Ltd.), which has a relatively low viscosity and high cross-linking performance, is used as a main agent, and 1-hydroxycyclohexylphenyl ketone (manufactured by Ciba Geigy) is used as a photoinitiator. Irgacure 184) as a leveling agent, and a polyether-modified silicone oil (Toshiba silicone SH28) as a leveling agent.
PA) was roll-coated on the polycarbonate film by microgravure without diluting a coating solution containing 0.1% by weight of the main component with a solvent. Thereafter, the coating film is continuously subjected to the following steps in the transport process until it is wound up again in a roll shape. That is, a step of laminating a mold film unwound using a transport path different from the transport path used for coating on a coating surface using a nip roll, and a step of 60 minutes in order to make the coated coating liquid and the mold surface well blend.
C. through a drying oven for 1 minute, ultraviolet rays (integrated light amount 500 mJ / cm) through a mold film by a high-pressure mercury lamp having a lamp intensity of 120 W / cm arranged on the mold film side.
2) irradiating the coating layer by irradiating it, removing the mold film via a nip roll immediately after the film has passed the ultraviolet irradiation section, and forming the polycarbonate film and the mold film into a roll using separate transport paths. This is a winding step.

When the surface of the cured layer of the ultraviolet curable resin thus formed was observed by a scanning electron microscope or the like, hemispherical concave portions having an average diameter of about 160 nm were continuously formed at a pitch of about 160 to 200 nm. The formation was observed.

Next, a thin film of silicon dioxide was formed on the surface by sputtering. That is, the polycrystalline S
After evacuation to a pressure of 1.3 mPa using a metal target of i, an Ar / O ₂ mixed gas (O ₂ concentration 12 vol%) was introduced at a gas flow rate of 100 sccm, and the pressure was 0.27 Pa
After adjusting so that the input power density becomes 1 W / cm ²
DC magnetron sputtering was performed under the conditions described above to form an SiO ₂ film having a thickness of about 20 nm by fluorescent X-ray measurement.

Next, CF ₃ (CF ₂ ) ₇ CH _{2 is used} as an anti-contamination layer.
A solution obtained by previously hydrolyzing CH ₂ —Si (OCH ₃ ) ₃ with dilute hydrochloric acid by a known method is diluted with ethanol to a solid content concentration of 0.02% by weight to carry out microgravure coating using a coating solution. By heat drying for 5 minutes, an extremely thin layer of the fluoroalkylalkoxysilane condensate was formed.

As described above, the light reflectance on the laminated surface side of the polycarbonate film on which the cured layer of the ultraviolet curable resin, the silicon dioxide layer, and the anti-contamination layer are laminated in this order is measured by the diffuse reflectance of a Hitachi spectrophotometer U-3500. When measured in the measurement mode (the back surface of the film was coated with black paint to eliminate the influence of back surface reflection), the reflectance was in the range of 0.7 to 0.9% in the visible wavelength region of 400 to 700 nm. And had very excellent antireflection properties. The haze of this film was measured using a haze meter COH- manufactured by Nippon Denshoku Industries Co., Ltd.
When measured using 300A, the haze was as small as 0.6%. Furthermore, the contact angle of fats and oils on this surface was measured. When oleic acid (manufactured by Wako Pure Chemical Industries) was used as a measuring solution and the contact angle was measured when the solution was gently dropped on the surface, the contact angle was about 107 degrees, indicating that the surface was very excellent in oil repellency.

Example 2 One side of a 1.1 mm thick glass substrate was coated with an ultraviolet curable resin having the same composition as in Example 1 using a knife coater, and the mold film prepared in Example 1 was laminated. Thereafter, the substrate was irradiated with ultraviolet light from a high-pressure mercury lamp having a substrate temperature of 60 ° C. and a lamp intensity of 120 W / cm (integrated light amount: 500 mJ / cm ² ), and the mold film was peeled off, whereby hemispherical concave portions were continuously formed on the surface. A cured layer of an ultraviolet curable resin having a thickness of about 5 μm was formed on a glass substrate.

Next, the glass substrate on which the cured layer of the ultraviolet curable resin was laminated was introduced into a DC sputtering apparatus, and an Al film having a thickness of 30 nm was formed as an electrode layer on the cured layer by sputtering. The substrate on which this electrode layer was formed was quickly introduced into a plating apparatus, and a nickel film was deposited to a thickness of 0.3 mm on the previous electrode layer by electroplating. Further, after the nickel deposition surface was polished and flattened, the glass substrate on which the cured layer of the ultraviolet curable resin was laminated was peeled off. Then, the residue of the ultraviolet curable resin was thoroughly washed and removed to obtain a nickel mold in which hemispherical concave portions were continuously formed on the surface.

Using an injection molding machine (model name: DISK-MIII) manufactured by Sumitomo Heavy Industries, Ltd., the above-mentioned nickel mold was attached to a mold, and a thickness was determined using a polycarbonate resin (Teijin Chemicals AD9000TG). A polycarbonate resin plate having a length of 0.7 mm and a length and width of 80 mm was molded.

The condition at this time is as follows.
8 ° C., and the fixed mold temperature was 115 ° C. Injection speed is 1
A molten resin at 380 ° C. at 00 mm / sec was filled into the cavity of the mold to which the mold was attached, through a sprue portion. The pressure of the compression part core is 2 for 0.5 second after the injection is completed.
The pressure was changed to 500 kPa and thereafter to 6500 kPa.
The mold opening time was set 9 seconds after the end of injection. After the mold was air-cooled, the molded resin plate was removed from the mold with bare hands. At this time, the resin filled in the sprue portion was connected to the back surface of the resin plate in a convex shape, but this portion was cut off by a cutter to flatten the back surface.

When the surface of the thus obtained polycarbonate resin plate on the side where the mold was transferred was observed by a scanning electron microscope or the like, hemispherical concave portions having an average diameter of about 160 nm were continuously formed at a pitch of about 160 to 200 nm. The formation was observed.

The light reflectance of the surface of the polycarbonate resin plate on which hemispherical concave portions are continuously formed is 400 to 700.
It was in the range of 0.6 to 0.8% in the visible wavelength region of nm, and the haze was as small as 0.8%.

[Comparative Example 1] The UV curable resin coated on the polycarbonate film in Example 1 was cured by irradiating it with UV light in the air without laminating the mold film of the Example, and the surface was smoothed to a thickness of about 5 μm. After forming a hardened layer, a silicon dioxide layer and an antifouling layer were laminated as in the example. 400 to 700 of the laminated surface of this film
The light reflectance in the visible wavelength region of nm is about 3.5 to 3.7.
% Range.

Comparative Example 2 An ultraviolet curable resin coated on a polycarbonate film in the same manner as in Example 1
The mold film of Example 1 was cured by irradiating it with ultraviolet light in the air without laminating, to form a cured layer having a thickness of about 5 μm and a smooth surface. Next, a treatment strength of 10
After applying a corona treatment of 0 W · min / m ^2, a coating liquid composed of a spherical silica fine particle and a binder of an alkoxysilane hydrolyzate is coated as in the example, and a layer in which hemispherical convex portions are arranged adjacently on the surface. Was formed. Further, a layer of silicon dioxide and an antifouling layer were laminated on this surface as in the example. The light reflectance of the laminated surface of this film in the visible wavelength region of 400 to 700 nm is in a range of about 1.7 to 2.0%,
The antireflection properties were not so good.

[Comparative Example 3] The injection molding of the polycarbonate resin plate in Example 2 was flattened by well polishing both sides instead of the nickel mold used in Example 2.
The test was performed using a nickel plate having a thickness of 3 mm. The reflectance of the surface of the injection-molded polycarbonate resin plate is 40
About 4.9 to 5.4% in a visible wavelength range of 0 to 700 nm
Was in the range.

[0065]

According to the present invention, it has become possible to obtain an article having excellent antireflection properties by a simpler method than before. In addition,
Since the mold used in the present invention can be used several times or more usually, the production process can be further simplified, and mass replication from the mold can be performed, and higher productivity can be obtained. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing the shape of a layer having a refractive index gradient used in the present invention.

FIG. 2 is a cross-sectional view schematically showing the shape of a layer having a refractive index gradient conventionally proposed.

FIG. 3 is a cross-sectional view schematically showing a structure of a mold for molding a layer having a refractive index gradient used in the present invention.

FIG. 4 is a schematic view showing an example of a method for forming a layer having a refractive index gradient using a mold in the present invention.

FIG. 5 is a schematic view of an injection molding die used to obtain an article having an uneven shape integrally formed on a surface in the present invention.

FIG. 6 is a scanning electron micrograph of a cured layer surface of an ultraviolet curable resin to which the surface shape of a mold film is transferred in an example of the present invention.

[Explanation of symbols]

 1. 1. Polymer resin layer 2. Layer having refractive index gradient Support base 4. Primer layer 5. Binder layer 6. 6. spherical fine particles Support base 8. Support base 9. UV curable resin 10. Type 11. Layer having refractive index gradient 12. Movable mold 13. Compression unit 14. Fixed mold 15. Outer ring 16. Sprue section 17. Cavity 18. Type

Continued on the front page (72) Inventor Toshiaki Yatabe 4-3-2 Asahigaoka, Hino-shi, Tokyo Teijin Co., Ltd. Tokyo Research Center F-term (reference) 2H042 BA03 BA13 BA15 BA16 BA20 2K009 AA12 AA15 BB14 BB24 DD05 DD12 DD15 EE05 4F202 AG03 AG05 CA11 CA27 CB01 CB22 CB29 CD23 CD28 CD30 CK09 5G435 AA01 AA17 DD12 HH02 HH03 KK07

Claims (3)

[Claims] 1. A method for producing an article having an antireflection property, in which a concavo-convex shape having a pitch of an adjacent convex portion or concave portion in a range of 10 to 300 nm is continuously formed in at least one surface in a planar direction. Forming a shape having a relationship of a key and a keyhole on the surface using a mold having a relationship between the concave and convex shape and the key and the keyhole. 2. A method for producing an article having an antireflection property in which a concavo-convex shape having a pitch of adjacent convex portions or concave portions in a range of 10 to 300 nm is continuously formed in at least one surface in a planar direction. A method having a shape having a relation of a key and a keyhole on the surface by the injection molding method. 3. A method for producing an article having an antireflection property in which a concavo-convex shape having a pitch of adjacent convex portions or concave portions in a range of 10 to 300 nm is continuously formed on at least one surface in a planar direction. Then, after laminating the substrate and the mold via the precursor liquid of the radiation-curable resin, the substrate is irradiated with radiation through the mold or through the mold to cure the precursor liquid, and then the mold is separated. The method for producing an anti-reflective article according to claim 1, wherein the layers are formed by lamination.