JP6160186B2 - Fine concavo-convex structure, decorative sheet, decorative resin molded body, fine concavo-convex structure, and method for producing decorative resin molded body - Google Patents

Description

  The present invention relates to a fine concavo-convex structure having excellent antireflection performance and capable of three-dimensional molding such as insert molding, a decorative sheet, a decorative resin molded body, and a curable composition for forming the fine concavo-convex structure. The present invention also relates to a method for producing a fine concavo-convex structure that is excellent in antireflection performance and that can be three-dimensionally molded, and a decorative resin molded body.

In fields where higher design is required, such as lighting covers and front panels of various displays, it is required to provide antireflection performance to these final products in order to reduce “reflection”. In applications such as displays and lenses where reduction of reflection is desired, various antireflection techniques are applied, but there is a problem that it is difficult to develop curved surfaces and complex shapes.
As a conventional technology, there is known a technology to prevent reflection by applying a multi-layer coating consisting of a resin with a high refractive index and a resin with a low refractive index to the surface of the final product. It is very difficult to apply to a curved surface or a complicated shape.

On the other hand, it is known that a fine concavo-convex structure having a fine concavo-convex structure in which fine concavo-convex structures are regularly arranged on the surface exhibits antireflection performance by continuously changing the refractive index. In order for the fine concavo-convex structure to exhibit good antireflection performance, it is necessary that the distance between adjacent convex portions or concave portions be a size equal to or smaller than the wavelength of visible light. By applying such a fine concavo-convex structure to the surface of an object such as a display or a lens, good antireflection performance can be imparted to these final products. It is also known that such fine concavo-convex structure exhibits super water-repellent performance due to the Lotus effect.
As a method for producing a fine concavo-convex structure, an active energy ray-curable composition is disposed between a mold and a transparent substrate, and the active energy ray-curable composition is cured by irradiation with an active energy ray, and a mold is obtained. The method of peeling the mold after transferring the concavo-convex shape of the above, or transferring the concavo-convex shape of the mold to the active energy ray-curable composition, peeling the mold, and then irradiating the active energy ray to the active energy ray A method for curing a curable composition is known. However, it is not easy to obtain the reflection performance by providing the fine concavo-convex structure on the surface of a product having a complicated shape, and there is a problem in terms of manufacturing cost.

On the other hand, a method of laminating a decorative sheet on the surface of a molded body is known as a method for imparting designability, weather resistance, scratch resistance, etc. to the surface of a molded body having a complicated shape. As a molding method of such a decorative resin molded body, a decorative sheet is molded in a three-dimensional shape in advance by a vacuum mold, the molded sheet is inserted into an injection mold, and a resin material in a fluid state is placed in the mold. An injection molding method in which the resin material and the molded sheet are integrated by injection, or a decorative sheet inserted into the mold during the injection molding is integrated with the molten resin injected into the cavity An injection molding simultaneous decorating method for decorating the surface of the molded body is exemplified.
Therefore, when the above-mentioned performance other than the antireflection performance is imparted to the surface of the molded body, it is necessary to perform three-dimensional molding such as insert molding or press molding, and a film capable of such three-dimensional molding is desired. ing.
The above-mentioned antireflection film by multilayer coating expresses antireflection performance by precisely controlling the refractive index and thickness of each layer. Therefore, when used for three-dimensional molding such as insert molding and press molding, There is a problem that the antireflection performance cannot be sufficiently exhibited.

Patent Documents 1 and 2 disclose a method of manufacturing an antireflection article having a fine concavo-convex structure on the surface by providing a fine concavo-convex structure on a curved mold surface and performing press molding or injection molding. In the methods described in these Patent Documents 1 and 2, it is possible to impart a desired fine concavo-convex structure to a molded body by providing an inverted structure of the fine concavo-convex structure in the mold. It is difficult to form an inverted structure of the desired fine concavo-convex structure in the inside, and since it is premised that a molten resin that can be injection molded is used, it is extremely difficult to provide functions other than antireflection performance. .
In addition, when the above-described fine concavo-convex structure is used for three-dimensional molding, the scratch resistance is inferior to a molded body such as a hard coat having a smooth surface, produced using the same curable composition. The molded body in which the fine concavo-convex structure is laminated has a problem in durability during use.
Patent Document 3 discloses that it is desirable that the cured resin constituting the fine concavo-convex structure has a high elastic modulus from the viewpoint of scratch resistance.
Moreover, in the structure where the fine convex portions are forested, when the aspect ratio of the fine convex portions is large and the elastic modulus of the cured resin is low, a phenomenon in which the adjacent convex portions come close to each other may occur. The cluster of convex parts that are close together can be regarded as one large convex part, but if the aggregate of convex parts becomes as large as the visible light wavelength, light is diffusely reflected, resulting in a fine structure. It is known that the concavo-convex structure becomes cloudy and the haze value increases. That is, when the cured product of the active energy ray-curable composition used for the production of the fine concavo-convex structure is not sufficiently robust, a phenomenon in which the fine concavo-convex convex portions nestle with each other due to release from the mold or heating occurs. As a result, there arises a problem that the antireflection performance is lowered.
For these reasons, as a curable composition for forming a fine concavo-convex structure, a cured product can be used so as to avoid a phenomenon in which convex portions are close to each other and a haze value is increased while maintaining antireflection performance. Generally, a material having a high elastic modulus is used. However, in such a curable composition, since the cured product does not “elongate”, that is, does not have “extensibility”, it is impossible to perform the three-dimensional molding described above.
When a fine concavo-convex structure is formed using a curable composition having a cured product that is flexible and excellent in extensibility, the fine concavo-convex structure can be used for three-dimensional molding, but the protrusions lie close to each other. Occurs and the antireflection performance is impaired. For example, when a fine concavo-convex structure is formed using a curable composition composed of a monofunctional monomer and a bifunctional monomer as described in Patent Document 4, the convex portions of the fine concavo-convex structure are close to each other. It grows to a size that scatters light, resulting in a cloudy appearance.

JP 2000-71290 A JP-T-2001-525269 International Publication No. 2012/096322 JP2012-139914A

  The present invention has been made to solve the above-described problems. That is, an object of the present invention is to provide a fine concavo-convex structure, a curable composition, a decorative sheet, and a decorative resin molding obtained by molding the decorative sheet, which have excellent antireflection performance and can be applied to three-dimensional molding. It is providing the manufacturing method of a body, a fine concavo-convex structure, and a decorative resin molding.

The anti-reflective performance in the fine concavo-convex structure is that the refractive index is apparently continuous when the ratio of the fine concavo-convex structure and air in the cross section changes continuously when viewed from the direction perpendicular to the fine concavo-convex structure surface. It is an important requirement to behave as if there is no interface due to changes. The present inventors do not necessarily have a structure in which the fine convex portions are erected, and the antireflection performance by such a fine concave and convex structure is not an inverted structure of the fine convex portions, that is, a structure in which the fine concave portions are formed in an orderly manner. Even so, it was found that there is no significant difference in antireflection performance. If the interval between the fine recesses is a “fine concavo-convex structure” having a size equal to or smaller than the wavelength of visible light, it is a case where a fine concavo-convex structure is formed using a curable composition having a low elastic modulus of the cured product. However, the convex portions are not united.
The inventors of the present application have antireflection performance by forming a fine concavo-convex structure having a fine concavo-convex structure using a curable composition having high flexibility and extensibility in a cured resin. And it discovered that the fine concavo-convex structure body which can be three-dimensionally molded, and a decoration sheet were obtained, and came to complete this invention.

That is, the aspect of this invention has the following characteristics.
[1] A fine concavo-convex structure having a fine concavo-convex structure on the surface, comprising a cured product of the curable composition, and the cured product has a tensile elongation at break of 20% or more;
[2] The fine concavo-convex structure according to [1], wherein a toughness in a tensile test at 80 ° C. of the cured product is 1 kJ / m ² or more;
[3] At least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups, 70 parts by mass or more with respect to parts, the mass average molecular weight of the bifunctional monomer (Y) is 600 or more, and the value of the polyfunctional monomer (Z) divided by the number of polymerizable functional groups Is a curable composition for forming a fine concavo-convex structure according to [1] or [2];
[4] The bifunctional monomer (Y) is at least one bifunctional acrylate selected from the group consisting of a bifunctional urethane (meth) acrylate and a bifunctional polyether (meth) acrylate,
The polyfunctional monomer (Z) is one or more polyfunctional acrylates selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate,
The curable composition according to [3], wherein the total amount of the bifunctional acrylate and the polyfunctional acrylate is 30 parts by mass or more with respect to 100 parts by mass of the curable component;
[5] The curable composition is at least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups. 70 parts by mass or more with respect to 100 parts by mass of the curable component, the mass average molecular weight of the bifunctional monomer (Y) is 600 or more, and the mass average molecular weight of the polyfunctional monomer (Z) The fine relief structure according to [1] or [2], wherein the value divided by the number of groups is 300 or more;
[6] The bifunctional monomer (Y) is at least one bifunctional acrylate selected from the group consisting of a bifunctional urethane (meth) acrylate and a bifunctional polyether (meth) acrylate,
The polyfunctional monomer (Z) is one or more polyfunctional acrylates selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate,
The fine uneven structure according to [5], wherein the total amount of the bifunctional acrylate and the polyfunctional acrylate is 30 parts by mass or more with respect to 100 parts by mass of the curable component;
[7] A decorative sheet comprising the fine uneven structure according to [1] or [2];
[8] A decorative resin molded body including the decorative sheet according to [7];
[9] A vehicle member including the decorative resin molded body according to [8];
[10] A display member comprising the decorative resin molded product according to [8];
[11] A method for producing a fine concavo-convex structure having a fine concavo-convex structure on the surface, wherein [3] or [4] is provided between the surface of the mold having a fine bulge structure on the surface and the substrate. A method for producing a fine concavo-convex structure comprising a step of disposing the mold after disposing the curable composition and curing the curable composition;
[12] A decorative resin molded body having a fine concavo-convex structure on its surface by heating the decorative sheet according to [7], evacuating the heated decorative sheet, or pressing the compressed sheet against compressed air. A process for producing a decorative resin molded article having a fine concavo-convex structure on the surface thereof, comprising the step (A1) of obtaining
[13] A method for producing a decorative resin molded body having a fine concavo-convex structure on its surface, wherein the mold shape is transferred by pressing the mold while heating the decorative sheet according to [7], and the mold shape is transferred. The step (B1) of removing the decorated sheet after the mold from the mold and obtaining the decorated sheet to which the mold shape has been transferred, and the fine uneven structure of the decorative sheet obtained in the step (B1) are formed. The mold side is placed in contact with the mold surface for injection molding, and a molten resin material is injected into the mold for injection molding and solidified to form a molding substrate made of the resin material and a fine uneven structure. And a step (B2) of obtaining a decorative resin molded body having a decorative sheet in which the surface opposite to the formed side is in contact with the molded base material. Production method;
[14] A method for producing a decorative resin molded body having a fine concavo-convex structure on a surface thereof, wherein the decorative sheet according to [7] is arranged so that the side on which the fine concavo-convex structure is formed is in contact with an injection mold Step (C1), and while the decorative sheet is heated in the injection mold, the mold is pressed along the inner surface of the injection mold, and then the mold is closed. A resin material in a molten state is injected and solidified therein, and has a molded base material made of the resin material, and a decorative sheet in which the surface opposite to the side on which the fine concavo-convex structure is formed is in contact with the molded base material Including a step (C2) of obtaining a decorated resin molded body, a method for producing a decorated resin molded body having a fine concavo-convex structure on the surface;
[15] Fine irregularities including the step (D1) of pressing the heated mold to the decorative sheet according to [7] to transfer the shape of the mold and obtaining a decorated resin molded body having a fine irregular structure on the surface The manufacturing method of the decorative resin molding which has a structure on the surface.

  The decorative sheet according to the present invention is a fine concavo-convex structure having a fine concavo-convex structure on the surface, which is composed of a cured product of a curable composition, and the cured product has a tensile rupture elongation of 20% or more. By including the body, the antireflection performance is prevented from being impaired by the uniting of the convex portions while enabling three-dimensional molding. As a result, it has become possible to impart an antireflection structure to the surface of a three-dimensional molded body having a complicated shape, which has been difficult with the prior art.

It is a typical sectional view showing an embodiment of a fine concavo-convex structure of the present invention. It is typical sectional drawing which shows embodiment of the decorating sheet of this invention. It is typical sectional drawing which shows an example of the manufacturing process of the mold used in order to form the fine concavo-convex structure of this invention. It is sectional drawing which shows an example of the manufacturing process of the decorating resin molding of this invention.

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

<Fine uneven structure>
The fine concavo-convex structure of the present invention comprises a cured product of a curable composition, and the tensile elongation at break of the cured product is 20% or more. Examples of the curable composition include at least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups. Are preferably those containing 70 parts by mass or more with respect to 100 parts by mass of the curable component. Furthermore, the bifunctional monomer (Y) is at least one bifunctional acrylate selected from the group consisting of a bifunctional urethane (meth) acrylate and a bifunctional polyether (meth) acrylate, and the polyfunctional The monomer (Z) is one or more polyfunctional acrylates selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate, the bifunctional acrylate and the The total amount of the polyfunctional acrylate is preferably 30 parts by mass or more with respect to 100 parts by mass of the curable component.
Moreover, it is preferable that the curable composition of this invention is an active energy ray curable composition. Since the fine concavo-convex structure of the present invention is made of a cured product of a specific curable composition and has a fine concavo-convex structure on the surface, the antireflection performance is hardly impaired by the uniting of the convex portions. Therefore, by applying the fine concavo-convex structure of the present invention to the decorative sheet, an antireflection structure can be imparted to the surface of the three-dimensional molded body having a complicated shape.

(Tensile breaking elongation)
The fine concavo-convex structure of the present invention is a cured product of a curable composition, and the tensile elongation at break of the cured product is 20% or more.
The tensile elongation at break of the cured product can be measured according to JIS K 7161. As an example, a curable composition is poured between two glass plates, cured with a spacer having a thickness of about 0.2 mm, molded into a plate shape, and punched into a predetermined dumbbell shape from this plate Is a specimen for a tensile test.
The tensile test is performed using a general tensile tester at a test speed of 1 mm / min. A value obtained by dividing the elongation at the time when the test piece is broken by the distance between the marked lines of the dumbbells is the tensile breaking elongation. The tensile elongation at break of the present invention refers to a value measured under an environment of 80 ° C.
The tensile elongation at break of 20% or more means that, for example, when the punched shape is a JIS standard dumbbell-shaped No. 2, the distance between marked lines is 20 mm. If the elongation between the marked lines is considered to be extended and the elongation at break is 20% or more, the dumbbell-shaped sample is gripped by the chuck of the tensile tester, the point where stress begins to be applied is 0 point, and if the elongation is 4 mm or more The elongation at break is 20% or more.
If the tensile elongation at break is 20% or more, when the decorative sheet containing the fine concavo-convex structure of the present invention is three-dimensionally molded, the fine concavo-convex structure is not cracked, and good antireflection Performance can be imparted to the surface of the molded body.
A high tensile elongation is required when three-dimensionally forming a very complicated shape, particularly a deeply drawn shape. Therefore, it is preferable that the tensile elongation at break is larger. On the other hand, if the tensile elongation at break is too high, the fine concavo-convex structure may be broken, and the optical performance may be impaired. Accordingly, the tensile elongation at break is more preferably 30 to 100%, particularly preferably 50 to 80%.

(Toughness)
In addition, the toughness (toughness) of the fine concavo-convex structure is also important.
In the case of the above-mentioned insert molding, a pre-molding, that is, a decorative sheet molded in advance into a predetermined shape by vacuum molding or the like is placed in a mold, and then a molten resin is injected and filled in the mold. Integrate with decorative sheet. The decorative sheet is generally pre-molded slightly smaller than a mold for obtaining a final molded body. The mold for injection molding is usually temperature-controlled at about 60 to 120 ° C., but the decorative sheet is arranged in this mold, so that the temperature becomes substantially equal to that of the mold. In this state, the molten resin is injected, and the decorative sheet is stretched by the injection pressure and conforms to the mold shape. At this time, if the decorative sheet does not have sufficient toughness, the decorative sheet may crack when the injection pressure of the molten resin is applied.
The decorative sheet of the present invention preferably contains a sheet base material in addition to the fine concavo-convex structure, but when such a decorative sheet is used for insert molding, the sheet base material is usually a thermoplastic polymer. Therefore, even if the injection pressure of the molten resin is applied, the sheet base material is hardly cracked. Therefore, it is desirable that the toughness (toughness) of the fine concavo-convex structure of the present invention is high.
That is, the fine concavo-convex structure of the present invention is preferably made of a curable composition having a toughness of 1 kJ / mm ² or more in a tensile test at 80 ° C. of the cured product. Further, toughness in a tensile test at 80 ° C. of the cured product is preferably at 2 kJ / ^{m 2} or more, more preferably 5 kJ / ^{m 2} or more. If the toughness in the tensile test at 80 ° C. of the cured product is 1 kJ / m ² or more, cracks can be avoided when the decorative sheet including the fine concavo-convex structure of the present invention is three-dimensionally formed. Further, toughness at 80 ° C. of fine uneven structure of the present invention is more preferably 2~10kJ / mm ^2, particularly preferably 4~8kJ / mm ^2.

As the fine concavo-convex structure of the present invention, for example, a fine concavo-convex structure 10 having a substrate 11 and a cured product 12 having fine dents 14 on the surface as shown in FIG.
FIG. 1 is a schematic cross-sectional view showing an embodiment of a fine relief structure 10 of the present invention. The fine concavo-convex structure shown in FIG. 1A is obtained by laminating a cured product 12 of the curable composition of the present invention on a substrate 11.
The surface of the cured product 12 has a fine uneven structure. In the fine concavo-convex structure, the inverted conical concave portion 14 and the convex portion 13 are formed at equal intervals w ₁ . The shape of the recess is such that the cross-sectional area in the vertical plane continuously increases from the base material side to the apex side, so that the refractive index can be continuously increased, and the reflectance varies with wavelength ( (Wavelength dependence) is suppressed, and scattering of visible light can be suppressed to achieve a low reflectance.

As the fine concavo-convex structure, a structure in which a so-called moth-eye structure is inverted, in which a plurality of protrusions (convex parts) having a substantially conical shape or a pyramid shape are arranged, is preferable. It is known that the moth-eye structure in which the distance between the concave portions is equal to or less than the wavelength of visible light becomes an effective antireflection means by continuously increasing the refractive index from the refractive index of air to the refractive index of the material. ing.
The average interval between the recesses is not more than the wavelength of visible light, that is, not more than 400 nm. When the convex portions are formed using a mold of anodized alumina, which will be described later, the average distance between the convex portions is about 100 nm, and is preferably 200 nm or less, and particularly preferably 150 nm or less. Moreover, it is preferable that it is 20 nm or more from the point of the ease of formation of a recessed part. That is, the average interval between the recesses is preferably 20 to 400 nm, more preferably 60 to 300 nm, and particularly preferably 100 to 250 nm.
The average interval between the recesses means a value obtained by measuring 50 intervals between adjacent recesses (distance from the center of the recess to the center of the adjacent recess) by electron microscope observation and averaging these values.

When the average interval of the recesses is 100 nm, the depth of the recesses is preferably 80 to 500 nm, more preferably 120 to 400 nm, still more preferably 150 to 300 nm, and particularly preferably 180 to 300 nm. If the depth of the recess is 80 nm or more, the reflectance is sufficiently low and the wavelength dependence of the reflectance is small.
The depth of the concave portion is a value obtained by measuring the distance between the bottom of the concave portion and the top of the convex portion existing between the concave portions when observed with an electron microscope at a magnification of 30000 times.
The aspect ratio of the recess (depth of recess / average interval between recesses) is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and particularly preferably 1.5 to 3.0. If the aspect ratio of the recess is 1.0 or more, the reflectance is sufficiently low.

  In addition, the shape of the recess is a shape in which the cross-sectional area of the recess in the direction perpendicular to the height direction continuously increases from the outermost surface in the depth direction, that is, the cross-sectional shape in the height direction of the recess is a triangle, U-shape, A shape such as a trapezoid is preferred. It is preferable that the inclination angle is large in the shape of the recess, particularly in the portion close to the top of the protrusion existing between the recesses. When the inclination angle is large, the antireflection performance when viewed from an oblique direction is improved when the viewing angle deviates from the front. Moreover, it is preferable that the lowest part of a recessed part is a curved surface. Even when the cross section is trapezoidal, it is preferable that the bottom is a surface that fits in a circle having a diameter of 200 nm. In addition to reflection between the recesses, it can also be reflected at the bottom of the recess, so that it is preferably sufficiently smaller than the wavelength of light.

As shown in FIG. 1B, the concave portion may have a bell shape in which the bottom portion 14b of the concave portion is a curved surface, and the cross-sectional area in the vertical plane continuously increases from the base material side to the bottom side. Shape can be adopted.
The fine concavo-convex structure of the present invention is not limited to the embodiment shown in FIG. 1, and can be formed on one side or the entire surface of the substrate, or on the whole or a part. Further, in order to effectively exhibit the water repellency, the tip of the bottom of the recess is preferably thin, and the area occupied by the cured product on the contact surface between the fine concavo-convex structure and the water droplet is preferably as small as possible.

In the fine concavo-convex structure of the present invention, when the concave portion is viewed from above as a perfect circle, and the concave portion is in a hexagonal lattice arrangement and is closely packed without overlapping, the area of the smooth portion is 9.3%. Become. If it arrange | positions so that a recessed part may overlap, the area of a smooth part will reduce. Even when the area of the smooth portion is 0%, the partition walls can be observed when SEM observation is performed. However, the partition wall that can be observed in this way does not necessarily have a smooth upper part. When the inclination angle of the concave portion in the portion close to the top of the convex portion existing between the concave portions is small, it can be observed from above so that the partition wall is thick. In the case of such a shape, the antireflection characteristic when observed from an oblique direction may be impaired.
In the case of a porous structure having a large number of concave portions, even if the cured product constituting the fine concave-convex structure has a low elastic modulus and is flexible, the phenomenon that adjacent convex portions are united does not occur. preferable.

(Base material)
The shape of the base material 11 may be any of a sheet shape, a film shape, and the like, and the manufacturing method thereof may be, for example, one manufactured by any manufacturing method such as injection molding, extrusion molding, or cast molding. Furthermore, the surface of the substrate 11 may be subjected to coating or corona treatment for the purpose of improving properties such as adhesion, antistatic properties, scratch resistance, and weather resistance.
Such a fine concavo-convex structure can be applied as an antireflection film, and provides a high scratch resistance and a contaminant removal effect such as excellent fingerprint removability.
Moreover, you may provide the intermediate | middle layer 15 for improving various physical properties, such as abrasion resistance and adhesiveness, between the base material 11 and the hardened | cured material 12. FIG. Examples of the material for forming the intermediate layer 15 include an active energy ray-curable resin composition, a thermoplastic resin, an inorganic material, and the like. However, since the fine uneven structure is easily formed, the intermediate layer 15 is active energy ray-curable. A layer made of a cured product of the resin composition is preferred.

  The substrate 11 may be any material as long as it can support the cured product 12 having a fine concavo-convex structure, but the decorative sheet containing the fine concavo-convex structure of the present invention is formed for a display member. When it does, it is preferable that it is a transparent base material, ie, the material which permeate | transmits light. Examples of the material constituting the transparent substrate include synthetic polymers such as methyl methacrylate (co) polymer, polycarbonate, styrene (co) polymer, methyl methacrylate-styrene copolymer, cellulose diacetate, cellulose triacetate, and cellulose. Semi-synthetic polymers such as acetate butyrate, polyesters such as polyethylene terephthalate and polylactic acid, polyamide, polyimide, polyether sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polyurethane And composites of these polymers (composites of polymethyl methacrylate and polylactic acid, composites of polymethyl methacrylate and polyvinyl chloride, etc.) and glass. When three-dimensional processing such as insert molding is performed, a thermoplastic polymer is preferable, and for example, an acrylic resin and a polycarbonate resin are preferable.

(Curable composition)
In the fine uneven structure 10 of the present invention, the cured product 12 is selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups. 70 parts by mass or more with respect to 100 parts by mass of the curable component, the mass average molecular weight of the bifunctional monomer (Y) is 600 or more, and the mass average of the polyfunctional monomer (Z) A cured product of the curable composition having a value obtained by dividing the molecular weight by the number of polymerizable functional groups is 300 or more.
Furthermore, the bifunctional monomer is one or more bifunctional acrylates selected from the group consisting of bifunctional urethane (meth) acrylates and bifunctional polyether (meth) acrylates. The polyfunctional monomer (Z) is one or more polyfunctional acrylates selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate, 2 The total amount of the functional acrylate and the polyfunctional acrylate is more preferably 30 parts by mass or more with respect to 100 parts by mass of the curable component.
Moreover, it is preferable that the hardened | cured material 12 is a hardened | cured material of an active energy ray curable composition. By forming the fine concavo-convex structure using the curable composition, the tensile rupture elongation of the fine concavo-convex structure of the present invention can be 20% or more.
Moreover, the curable composition of this invention may contain the polymeric compound other than the said monomer.
Examples of the polymerizable compound include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule.
Moreover, a non-reactive polymer and an active energy ray sol-gel reactive composition may be included.

  As monofunctional monomer (X), methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, lauryl (meth) acrylate , Alkyl (meth) acrylates such as myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; benzyl (meth) acrylate; tetrahydrofurfuryl ( (Meth) acrylate; (meth) acrylate having an amino group such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, hydroxypropyl (Meth) acrylates having a hydroxyl group such as (meth) acrylate; (meth) acrylamide derivatives such as (meth) acryloylmorpholine and N, N-dimethyl (meth) acrylamide; 2-vinylpyridine; 4-vinylpyridine; N-vinylpyrrolidone N-vinylformamide; vinyl acetate. These may be used alone or in combination of two or more. Among them, (meth) acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, N-vinylpyrrolidone, N-vinylformamide, methyl (meth) acrylate, ethyl (meth) acrylate, It is preferable because it is not bulky and can promote polymerization reactivity of the curable composition. Moreover, when an acrylic film is used as the base material described later, methyl (meth) acrylate and ethyl (meth) acrylate are particularly preferable. Moreover, when using a polycarbonate as a base material, what has benzene ring structures, such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, and phenyl (meth) acrylate, is especially preferable.

As the bifunctional monomer (Y), a monomer having a mass average molecular weight of 600 or more is preferable. Here, “mass average molecular weight” means a value calculated by polystyrene conversion using gel permeation chromatography.
It is more preferable to use one or more bifunctional acrylates selected from the group consisting of bifunctional urethane (meth) acrylates and bifunctional polyether (meth) acrylates. Specifically, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol-propylene glycol di (meth) acrylate, polybutylene glycol di (meth) acrylate, polyethylene glycol-polybutylene glycol di (meth) ) Acrylate, urethane diacrylate and the like. Among these, it is particularly preferable to use urethane diacrylate as one capable of maintaining a high elongation without significantly lowering the glass transition temperature of the cured product and making the cured product brittle.
Here, the urethane (meth) acrylate includes a polyurethane obtained by reacting an isocyanate compound and a polyol compound as a skeleton, and a (meth) acrylate having a hydroxyl group at a terminal is used as a (meth) acrylate having an isocyanate group. (Meth) acrylate sealed with Examples of the (meth) acrylate having a hydroxyl group at the terminal include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and a caprolactone-modified monomer manufactured by Daicel Corporation, “Placcel” 』Etc. can also be raised. Examples of the (meth) acrylate having an isocyanate group at the terminal include “Karenz” series of Showa Denko KK.
Polyether (meth) acrylate is (meth) acrylate containing a polyol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol as a skeleton.

The polyfunctional monomer (Z) having three or more functional groups has three or more radical polymerizable functional groups in the molecule. Thereby, the molecular weight between the crosslinking points of hardened | cured material becomes small, a crosslinking density can be made high, the elasticity modulus and hardness of hardened | cured material can be made high, and it can be made excellent in abrasion resistance. This radically polymerizable functional group is typically a (meth) acryloyl group. The polyfunctional monomer (Z) preferably has a value obtained by dividing the mass average molecular weight by the number of polymerizable functional groups is 300 or more. Moreover, it is more preferable that it is 400 or more, and it is still more preferable that it is 500 or more.
As such a polyfunctional monomer (Z), for example, a tri- or higher functional (meth) acrylate such as epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, or the like is used. be able to. Among these, the polyfunctional monomer (Z) is at least one polyfunctional acrylate selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate. Is more preferable.

Further, as the other monomer (H), a bifunctional monomer having a mass average molecular weight of 600 or less and a polyfunctional monomer having a value obtained by dividing the mass average molecular weight by the number of polymerizable functional groups may be 300 or less. Specific examples of the bifunctional monomer having a mass average molecular weight of 600 or less include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di (meth) acrylate. 1,10-decanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di ( (Meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, bisphenol A di (meth) acrylate, ethoxylated vinyl Phenol A di (meth) acrylate may include propoxylated bisphenol A di (meth) acrylate, and pentaerythritol di (meth) acrylate epoxy diacrylate. These may be used alone or in combination of two or more.
Specific examples of the polyfunctional monomer having a value obtained by dividing the mass average molecular weight by the number of polymerizable functional groups is 300 or less include trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tri (meth). Examples include acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and ethoxy modified or propoxy modified products thereof. It is done. These may be used alone or in combination of two or more. Commercially available products include, for example, “NK Ester” series ATM-4E manufactured by Shin-Nakamura Chemical Co., Ltd., “KAYARAD” series DPEA-12 manufactured by Nippon Kayaku, and “Aronix” series M manufactured by Toagosei. -305, M-450, M-400, M-405, “EBECRYL40” manufactured by Daicel-Cytec, Inc. (all are trade names).
Among these, from the viewpoint of adhesion to the substrate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) ) Acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate and the like having a low molecular weight are desirable. As one guideline, it is preferable from the viewpoint of adhesion to the substrate to use a material having a mass average molecular weight of 300 or less, more preferably 250 or less.

The content of the monofunctional monomer (X) in 100 parts by mass of the curable component is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 40 parts by mass or less, and particularly preferably 20 parts by mass or less. Moreover, 10-50 mass parts is preferable, 15-40 mass parts is more preferable, and 20-30 mass parts is especially preferable. If content of monofunctional monomer (X) is in the said range, since an unreacted monomer does not remain in hardened | cured material and an odor can be suppressed, it is preferable.
The total content of the bifunctional monomer (Y) and the polyfunctional monomer (Z), that is, (Y) + (Z) is preferably 10 to 90 parts by mass in 100 parts by mass of the curable component. 80 mass parts is more preferable, and 40-60 mass parts is especially preferable. If the total content of the bifunctional monomer (Y) and the polyfunctional monomer (Z) is within the above range, it is preferable in that the cured product 12 is small in shrinkage and hardly warps.
From the viewpoint of adhesion, it is also preferable to use the above-mentioned other monomer (H) having a low mass average molecular weight. On the other hand, a low mass average molecular weight is equivalent to an increase in crosslinking density. . Therefore, when the other monomer (H) having a mass average molecular weight of 300 or less is contained, the content of the other monomer (H) is curable from the viewpoint of keeping the tensile elongation at break of the fine concavo-convex structure at 20% or more. 30 parts by mass or less is preferable with respect to 100 parts by mass of the component, and 20 parts by mass or less is more preferable. However, it is preferable to use 10 parts by mass or more, more preferably 20 parts by mass or more from the viewpoint of adhesion.
70 parts by mass or more of at least one monomer selected from the group consisting of the monofunctional monomer (X), the bifunctional monomer (Y), and the polyfunctional monomer (Z) described above is included with respect to 100 parts by mass of the curable component. It is preferable to use the curable composition because the fine concavo-convex structure of the present application can have a sufficient tensile elongation at break. Further, at least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups is used as 100 parts by mass of a curable component. More preferably, it is contained in an amount of 80 parts by mass or more.
On the other hand, when the above-mentioned monomer is contained in an amount of 70 parts by mass or more with respect to 100 parts by mass of the curable component, the crosslinking density is extremely high, that is, the value obtained by dividing the mass average molecular weight by the number of polymerizable functional groups is extremely small. Specifically, the content of the polyfunctional monomer that is 150 or less, particularly 120 or less, is preferably 0 to 20 parts by mass, more preferably 0 to 10 parts by mass with respect to 100 parts by mass of the curable component. ˜5 parts by mass is particularly preferred. If the content of the polyfunctional monomer having an extremely high crosslinking density is within the above range, it is preferable because the tensile elongation at break of the cured product can be maintained at 20% or more.

  Moreover, the curable composition of the present invention is one or more selected from the group consisting of the bifunctional monomer (Y) consisting of a bifunctional urethane (meth) acrylate and a bifunctional polyether (meth) acrylate. One or more polyfunctional acrylates which are bifunctional acrylates and the polyfunctional monomer (Z) is selected from the group consisting of trifunctional or higher urethane (meth) acrylates and trifunctional or higher functional polyether (meth) acrylates It is preferable that the total amount of the bifunctional acrylate and the polyfunctional acrylate is 30 parts by mass or more with respect to 100 parts by mass of the curable component. If the total amount of the above-mentioned bifunctional acrylate and polyfunctional acrylate is 30 parts by mass or more with respect to 100 parts by mass of the curable component, it is preferable in that cracks do not easily occur during three-dimensional molding. In addition, it is preferable that the bifunctional monomer (Y) and the polyfunctional monomer (Z) are urethane (meth) acrylate or polyether (meth) acrylate because the toughness of the cured resin is also improved.

(Other contents)
The curable composition of the present invention preferably contains an active energy ray polymerization initiator. This active energy ray polymerization initiator is a compound that generates a radical that is cleaved by irradiation with active energy rays to initiate a polymerization reaction. The active energy ray means, for example, an electron beam, ultraviolet rays, visible rays, plasma, infrared rays or other heat rays. In particular, it is preferable to use ultraviolet rays from the viewpoint of apparatus cost and productivity.
Specific examples of the active energy ray polymerization initiator include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, t-butylanthraquinone, 2- Ethylanthraquinone; thioxanthones such as 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1 -Hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) Acetophenones such as butanone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2 Acylphosphine oxides such as 1,4,4-trimethylpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoylformate, 1,7-bisacridinylheptane, 9-phenyl Acridine is mentioned. These may be used alone or in combination of two or more. In particular, it is preferable to use two or more types having different absorption wavelengths. If necessary, persulfates such as potassium persulfate and ammonium persulfate, peroxides such as benzoyl peroxide, and thermal polymerization initiators such as azo initiators may be used in combination.
The content of the active energy ray polymerization initiator is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 100 parts by weight in total of the contents of all monomers contained in the curable composition. 5 parts by mass, particularly preferably 0.2 to 3 parts by mass. The content of 0.01 parts by mass or more is preferable because the curable composition is excellent in curability and the cured product has good mechanical properties, particularly scratch resistance. Moreover, by setting it as 10 mass parts or less, the elastic modulus and abrasion-resistant fall and coloring by the polymerization initiator which remain | survive in hardened | cured material can be suppressed.

The curable composition of the present invention may contain an active energy ray absorber and / or an antioxidant. The active energy ray absorbent is preferably one that absorbs active energy rays irradiated during curing of the curable composition and can suppress deterioration of the cured product.
Examples of the active energy ray absorber include benzophenone-based UV absorbers, benzotriazole-based UV absorbers, and benzoate-based UV absorbers. Examples of the commercially available products include 400 and 479 of “Tinubin (registered trademark)” series manufactured by Ciba Specialty Chemicals, and 110 of “Viosorb (registered trademark)” series manufactured by Kyodo Pharmaceutical. Examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and hindered amine-based antioxidants. Examples of the commercially available products include “IRGANOX (registered trademark)” series manufactured by Ciba Specialty Chemicals. These active energy ray absorbents and antioxidants may be used alone or in combination of two or more.
The content of the active energy ray absorbent and / or the antioxidant is preferably 0.01 to 5 parts by mass, more preferably 100 parts by mass of the total content of all monomers contained in the curable composition. Is 0.01 to 1 part by mass, particularly preferably 0.01 to 0.5 part by mass. By setting it as 0.01 or more, yellowing and haze increase of the cured product can be suppressed and weather resistance can be improved. By setting it as 5 mass parts or less, sclerosis | hardenability of a curable composition, abrasion resistance of hardened | cured material, and adhesiveness with the base material of hardened | cured material can be made favorable.

The curable composition contains a release agent, a lubricant, a plasticizer, if necessary, as long as the functions of the monofunctional monomer (X), the bifunctional monomer (Y), and the polyfunctional monomer (Z) are not impaired. Contains additives such as antistatic agents, light stabilizers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, silane coupling agents, colorants, reinforcing agents, inorganic fillers, impact modifiers, etc. May be.
Lubricants and slip agents are compounds that exist on the surface of a cured resin, reduce friction on the surface, and improve scratch resistance. Examples of commercially available slip agents include “SH3746 FLUID” and “FZ-77” manufactured by Toray Dow Corning, “KF-355A” and “KF-6011” manufactured by Shin-Etsu Chemical (all are trade names). These may be used alone or in combination of two or more.
The content of the slip agent is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass with respect to a total of 100 parts by mass of all monomers contained in the curable composition. is there. By setting it as 0.01 mass part or more, a curable composition is excellent in sclerosis | hardenability, and the mechanical characteristics of hardened | cured material, especially scratch resistance become favorable. By setting it as 5 mass parts or less, the elasticity modulus and abrasion-resistant fall and coloring by the slip agent which remain | survives in hardened | cured material can be suppressed.

  Moreover, although the curable composition of this invention may contain the solvent, the direction which does not contain is preferable. When the solvent is not included, for example, there is no concern that the solvent remains in the cured product in the process of polymerizing and curing by irradiation with active energy rays in a state where the curable composition is poured into a mold, and then releasing the mold. Moreover, when a manufacturing process is considered, the capital investment for solvent removal is unnecessary and it is preferable also at the point of cost.

(Physical properties of curable composition)
With respect to the viscosity of the curable composition, when a fine concavo-convex structure is formed by a mold and cured, the viscosity of the curable composition measured with a rotary B-type viscometer at 25 ° C. is preferably 10,000 mPa · s or less, More preferably, it is 5000 mPa * s or less, Most preferably, it is 2000 mPa * s or less. Even if this viscosity exceeds 10,000 mPa · s, workability is not impaired if a curable composition having a viscosity within the above range is used by heating. The viscosity of the curable composition measured with a rotary B-type viscometer at 70 ° C. is preferably 5000 mPa · s or less, more preferably 2000 mPa · s or less.
The viscosity of the curable composition can be adjusted by adjusting the type and content of the monomer. Specifically, when a large amount of a monomer containing a functional group having a molecular interaction such as a hydrogen bond or a chemical structure is used, the viscosity of the curable composition increases. Further, when a large amount of a low molecular weight monomer having no intermolecular interaction is used, the viscosity of the curable composition is lowered.

<Method for producing fine concavo-convex structure>
As a method for producing a fine concavo-convex structure of the present invention, for example, (1) a mold in which an inverted structure of a fine concavo-convex structure is formed on the surface, that is, the surface of a mold having a fine convex structure, a substrate, A method in which the curable composition is disposed between the layers, the curable composition is cured by irradiation with active energy rays, the uneven shape of the mold is transferred, and then the mold is peeled off, (2) the curable composition Examples include a method in which the convex shape of the mold is transferred to the mold, the mold is peeled off, and then the active energy ray is irradiated to cure the curable composition. Among these, the method (1) is particularly preferable from the viewpoint of the transferability of the fine concavo-convex structure and the degree of freedom of the surface composition. This method is particularly suitable when a belt-shaped or roll-shaped mold capable of continuous production is used, and is a method with excellent productivity.

The method for forming the inverted structure of the fine concavo-convex structure on the mold is not particularly limited, and specific examples thereof include an electron beam lithography method and a laser beam interference method. For example, an appropriate photoresist film is applied on an appropriate support substrate, exposed to light such as an ultraviolet laser, an electron beam, or X-ray, and developed to obtain a mold having a fine concavo-convex structure. It can also be used as it is as a mold. It is also possible to form a fine convex structure directly on the support substrate itself by selectively etching the support substrate by dry etching through the photoresist layer and removing the resist layer.
Anodized porous alumina can also be used as a mold. For example, a pore structure of 20 to 200 nm formed by anodizing aluminum with oxalic acid, sulfuric acid, phosphoric acid or the like as an electrolyte at a predetermined voltage may be used as a mold. According to this method, after anodizing high-purity aluminum for a long time at a constant voltage, the oxide film is once removed and then anodized again, whereby extremely highly regular pores can be formed in a self-organized manner. Further, in the second anodic oxidation step, by combining the anodic oxidation treatment and the hole diameter enlargement treatment, it is possible to form a fine concavo-convex structure whose cross section is not a rectangle but a triangle or a bell shape. Further, the angle of the innermost portion of the pore can be sharpened by appropriately adjusting the time and conditions of the anodizing treatment and the pore diameter expanding treatment.
Furthermore, a replica mold may be produced from an original mold having a fine concavo-convex structure by electroforming or the like and used as a mold.

The shape of the mold itself is not particularly limited, and may be, for example, a flat plate shape, a belt shape, or a roll shape. In particular, if a belt shape or a roll shape is used, the fine concavo-convex structure can be transferred continuously, and the productivity can be further increased.
The said curable composition is distribute | arranged between such a mold and a base material. As a method of disposing the curable composition between the mold and the substrate, the curable composition is pressed into the molding cavity by pressing the mold and the substrate with the curable composition disposed between the mold and the substrate. It can depend on the method of injecting an object.

As a method for polymerizing and curing the curable composition between the substrate and the mold by irradiating active energy rays, polymerization curing by ultraviolet irradiation is preferable. For example, a high-pressure mercury lamp, a metal halide lamp, or a fusion lamp can be used as the lamp that irradiates ultraviolet rays.
What is necessary is just to determine the irradiation amount of an ultraviolet-ray according to the absorption wavelength and content of a polymerization initiator. Normally, the integrated light quantity is preferably from ^{400~4000mJ / cm 2, 400~2000mJ / cm} 2 is more preferable. When the integrated light quantity is 400 mJ / cm ² or more, the curable composition can be sufficiently cured to suppress the scratch resistance from being deteriorated due to insufficient curing. Also. If the integrated light quantity is 4000 mJ / cm ² or less, it is significant in terms of preventing coloration of the cured product and deterioration of the substrate. The irradiation intensity is not particularly limited, but it is preferable to suppress the output to a level that does not cause deterioration of the substrate.
After polymerization and curing, the mold is peeled off to obtain a cured product having a fine concavo-convex structure to obtain a fine concavo-convex structure.
Moreover, when the said base material is a three-dimensional molded object etc., the formed fine uneven structure body can also be affixed on the three-dimensional molded object separately shape | molded.
The fine concavo-convex structure obtained in this way is transferred with the fine convex structure of the mold on the surface in a relationship between the key and the keyhole, has high scratch resistance, has water repellency, and has continuous refraction. Excellent antireflection performance can be achieved by changing the rate, and it is suitable as an antireflection film for films and three-dimensional shaped articles.

<Decoration sheet>
The decorative sheet according to the present invention is a fine concavo-convex structure having a fine concavo-convex structure on the surface, which is composed of a cured product of a curable composition, and the cured product has a tensile rupture elongation of 20% or more. Includes the body. By performing three-dimensional molding using the decorative sheet, it is possible to impart antireflection performance to the surface of a molded body having a complicated shape, which has been difficult with the prior art.
FIG. 2 is a cross-sectional view showing an example of the decorative sheet of the present invention. The decorative sheet 20 includes a sheet base material 22 and the above-described fine concavo-convex structure 10 formed on the surface of the sheet base material 22. A fine uneven portion (not shown) is formed on the surface of the fine uneven structure 10. The fine concavo-convex structure 10 plays a role as a cured resin film, and the thickness is preferably 1 to 50 μm, more preferably 1 to 10 μm, and still more preferably 2 to 8 μm. Further, the difference between the refractive index of the fine concavo-convex structure 10 and the refractive index of the sheet substrate 22 is preferably 0.2 or less, more preferably 0.1 or less, and particularly preferably 0.05 or less. If the refractive index difference between the fine concavo-convex structure 10 and the sheet base material 22 is 0.2 or less, reflection at the interface between the fine concavo-convex structure 10 and the sheet base material 22 is preferably suppressed.

(Sheet base material)
In the case where the decorative sheet of the present invention is formed for a display member, the sheet substrate 22 is preferably a transparent substrate, that is, a material that transmits light. Examples of the material of the sheet base material 22 include acrylic resins, polycarbonates, styrene resins, polyesters, cellulose resins (such as triacetyl cellulose), polyolefins, and alicyclic polyolefins. Among these, acrylic resins, polycarbonates, styrene resins, and polyesters are preferable, and acrylic resins are particularly preferable in terms of excellent transparency and weather resistance.

As the acrylic resin, JP-A-8-323934, JP-A-11-147237, and JP-A-2002-806 have scratch resistance, pencil hardness, heat resistance, and chemical resistance.
The acrylic resins described in JP-A-78, JP-A-2002-80679, and JP-A-2005-97351 are preferable. Further, in terms of resistance to molding whitening when insert molding (in-mold molding) is performed, JP-A-2005-163003 and JP-A-2005-139416.
The ones described in the Japanese Patent Publication No.
The sheet base material 22 includes known additives (stabilizers, antioxidants, lubricants, processing aids, plasticizers, impact agents, fillers, antibacterial agents, antifungal agents, mold release agents, antistatic agents, ultraviolet rays. Absorbers, light stabilizers, heat stabilizers, flame retardants, etc.).

10-500 micrometers is preferable, as for the thickness of the sheet | seat base material 22, 30-400 micrometers is more preferable, and 50-300 micrometers is especially preferable. If the thickness of the sheet base material 22 is 500 μm or less, rigidity suitable for insert molding (in-mold molding) can be obtained, and a film can be manufactured stably. If the thickness of the sheet base material 22 is 10 μm or more, the insert molded body can provide a sufficiently deep feeling together with the protection of the base material.
The sheet substrate 22 may be a laminated film or a laminated sheet.

  As a manufacturing method of the sheet | seat base material 22, well-known methods, such as a melt-extrusion method (melt-casting method, T-die method, inflation method), a calendar method, are mentioned, The T-die method is preferable from the point of economical efficiency. Further, when the sheet base material 22 is manufactured by the T-die method, the material of the sheet base material 22 is sandwiched between a plurality of rolls (metal rolls, etc.) or belts (metal belts, etc.) in order to improve surface smoothness. It is preferable to use a film forming method.

(Other layers)
The decorative sheet of the present invention may have other layers such as a thermoplastic resin layer, a decorative layer, an adhesive layer, and a primer layer.
A thermoplastic resin layer is a layer used as the base material at the time of forming a decoration layer, for example.
Examples of the material for the thermoplastic resin layer include acrylic resins, polycarbonates, styrene resins, polyesters, cellulose resins (such as triacetyl cellulose), polyolefins, and alicyclic polyolefins.

  The decorative layer is preferably present on the surface of the sheet base material 22 on the side opposite to the fine concavo-convex structure 10, and in the case of having a thermoplastic resin layer, between the sheet base material 22 and the thermoplastic resin layer. Preferably it is present. As a decoration layer, the printing layer formed by the printing method and the vapor deposition layer formed by the vapor deposition method are mentioned.

The printed layer is a pattern, pattern, character, or the like in the insert molded body. Examples of the printed pattern include wood grain, stone grain, cloth grain, sand grain, geometric pattern, character, and solid surface.
Examples of the method for forming the printing layer include an offset printing method, a gravure rotary printing method, a screen printing method, a roll coating method, a spray coating method, and a flexographic printing method. The thickness of the printing layer is usually about 0.5 to 30 μm.
Moreover, a printing layer can also be used as a concealing layer. The concealing layer is formed by a normal printing method such as gravure printing or a normal coating method such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating. Preferably, it is formed by applying by gravure coating and drying or curing.

  The vapor deposition layer is formed of a metal (aluminum, nickel, gold, platinum, chromium, iron, copper, indium, tin, silver, titanium, lead, zinc, or the like), an alloy thereof, or a compound thereof. Examples of the method for forming the vapor deposition layer include vacuum vapor deposition, sputtering, ion plating, and plating.

The primer layer or the adhesive layer is preferably formed in the outermost layer of the decorative sheet on the side opposite to the fine concavo-convex structure 10. Adhesive layers are gravure coat, gravure reverse coat, gravure offset coat, spinner coat, roll coat, reverse roll coat, kiss coat, wheeler coat, dip coat, solid coat with silk screen, wire bar coat, flow coat, comma coat, pouring It is formed by a usual coating method such as coating, brush coating, spray coating, or transfer coating method.
It is preferable to use a thermoplastic resin or a curable resin for the adhesive layer. Examples of thermoplastic resins include acrylic resins, acrylic-modified polyolefin resins, chlorinated polyolefin resins, vinyl chloride-vinyl acetate copolymers, thermoplastic urethane resins, thermoplastic polyester resins, polyamide resins, rubber resins, and the like. Can be used alone or in combination of two or more. Moreover, it is preferable to use a urethane resin, an epoxy resin, etc. as a thermosetting resin.
The difference between the refractive index of the adhesive layer and the adjacent layer, that is, the refractive index of the decorative layer or the sheet base material 22 is preferably 0.2 or less, more preferably 0.1 or less, and particularly preferably 0.05 or less. If the refractive index difference between the adhesive layer and the adjacent layer is 0.2 or less, reflection at the interface between the adhesive layer and the adjacent layer can be suppressed.
The thickness of the adhesive layer is usually about 1 to 5 μm.

<Method for producing decorative sheet>
The formation of the fine concavo-convex structure is as described above. On the other hand, as a method for producing a decorative sheet of the present invention, the above-described curable composition is prepared, applied onto a sheet base material, and crosslinked and cured in a state of covering a mold having a fine convex structure. Can be obtained. When the curable composition is cured with ultraviolet rays, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a fusion lamp, a carbon arc lamp, or the like is used.
The fine concavo-convex structure may be formed after the pattern layer and the adhesive layer on the back surface of the sheet substrate are provided, or the fine concavo-convex structure may be formed first, and then the functional layer on the back surface may be provided.
The decorative sheet of the present invention can be used for various injection molding methods such as insert molding method, injection molding simultaneous decoration method, blow molding method, gas injection molding method, etc. Preferably used. In the injection molding simultaneous decorating method, the decorative sheet receives the heat pressure from the resin material. Therefore, if the decorative sheet is close to a flat plate and the aperture of the decorative sheet is small, the decorative sheet may or may not be preheated. . In addition, as a resin material used here, the thing similar to the insert molding method can be used.

<Decorative resin molding>
The decorative resin molded body of the present invention has a molded base material made of a resin material and the decorative sheet of the present invention in which the surface opposite to the side on which the fine concavo-convex structure is formed contacts the molded base material. It is.
The molding substrate made of a resin material may be colored with a colorant (pigment, dye, etc.), and may be printed or painted on the surface.

(Resin material)
Examples of the resin material of the present invention include olefin resins (polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, olefin thermoplastic elastomer, etc.), styrene resins, ABS resin (acrylonitrile-butadiene-styrene copolymer), AS resin (acrylonitrile-styrene copolymer), acrylic resin, urethane resin, unsaturated polyester resin, epoxy resin, polyphenylene oxide / polystyrene resin, polycarbonate, polyacetal Polycarbonate modified polyphenylene ether, polyethylene terephthalate, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyether imide, polyimide, liquid crystal polyester Ether, polyallyl heat-resistant resin, various composite resin, various modified resins.

  The resin material may contain a colorant (pigment, dye, etc.). In addition, resin materials are known additives (stabilizers, antioxidants, lubricants, processing aids, plasticizers, impact agents, foaming agents, fillers, antibacterial agents, antifungal agents, mold release agents, antistatic agents. Agents, ultraviolet absorbers, light stabilizers, heat stabilizers, flame retardants, etc.).

The decorative resin molded body of the present invention can be suitably used for a vehicle member, a display member, and the like. Specifically, it is useful as an interior / exterior member, an optical product inner member, an optical lens, an electrical product member, a packaging container, a miscellaneous goods, and the like.
Interior / exterior components include automotive interior components (instrument panels, console boxes, meter covers, door lock pezels, steering wheels, power window switch bases, center clusters, dashboards, etc.), automotive exterior components (weather strips, bumpers, bumpers, etc.) Guards, side mud guards, body panels, spoilers, front grills, strut mounts, wheel caps, center pillars, door mirrors, center ornaments, side moldings, door moldings, wind moldings, windows, headlamp covers, tail lamp covers, windshield parts, etc.), automobiles Other examples include members for interior and exterior of various vehicles (trains, aircraft, ships, etc.).
Optical product internal members include optical product (camera, etc.) barrels, projection display devices such as front projectors and rear projectors, multivision systems equipped with a plurality of these projection display devices, digital still cameras, video cameras, etc. Examples include all optical devices that require removal of unnecessary light, such as imaging devices, optical pickup devices, and optical fiber communication systems.
Examples of the optical lens include resin lenses such as a pickup lens, a camera lens, and a spectacle lens.
Examples of the electrical product member include a housing, a button, and a switch.
Examples of the packaging container include a bottle, a cosmetic container, and an accessory case.
The miscellaneous goods include prizes and accessories.

<Method for producing decorative resin molding>
The decorative resin molded body of the present invention (hereinafter sometimes simply referred to as “molded body”) can be produced, for example, by the following production methods (I) to (IV). The molding temperature of the decorative resin molding varies depending on its shape and the resin material used, but usually 80 to 160 ° C. is one standard. In the case of producing a decorative resin molded body using a resin material that extends sufficiently at room temperature, it is generally easier to extend at higher temperatures.
(I) The decorative sheet of the present invention is heated, and the heated decorative sheet is evacuated or pressed against the mold by sending compressed air to obtain a decorative resin molded body having a fine uneven structure on the surface. The manufacturing method (what is called vacuum molding) of a decorative resin molding including a process (A1).
(II) The mold is pressed while the decorative sheet of the present invention is heated to transfer the mold shape, and the decorative sheet after the mold shape is transferred is taken out of the mold, and the mold shape is transferred to the decorative sheet. Obtaining a sheet (B1);
The decorative sheet obtained in the step (B1) is arranged so that the side on which the fine concavo-convex structure is formed is in contact with the injection mold surface, and the molten resin material is placed in the injection mold. By injection and solidification, a decorative resin molded body having a molded base material made of a resin material and a decorative sheet whose surface opposite to the side on which the fine concavo-convex structure is formed is in contact with the molded base material is obtained. A method for producing a decorative resin molded body having a fine concavo-convex structure on the surface, including the step (B2) (so-called insert molding, in-mold forming).
(III) The step (C1) of arranging the decorative sheet of the present invention so that the side on which the fine concavo-convex structure is formed is in contact with the injection mold,
While heating the decorative sheet in the injection mold, after pressing the mold along the inner surface of the injection mold, the mold is closed, and the resin material in a molten state in the mold A decorative resin molded body having a molded base material made of a resin material and a decorative sheet whose surface opposite to the side on which the fine concavo-convex structure is formed is in contact with the molded base material A process for producing a decorative resin molded article having a fine concavo-convex structure on the surface thereof (so-called in-mold lamination).
(IV) A fine concavo-convex structure including a step (D1) of pressing a heated mold on the decorative sheet of the present invention to transfer the shape of the mold and obtaining a decorative resin molded body having a fine concavo-convex structure on the surface. The manufacturing method of the decorative resin molding which has on the surface.
The manufacturing method of the decorative resin molded body is appropriately selected in consideration of the desired shape of the molded body, productivity, and the like. In general, it is preferable to use a molding method such as the production method (I) or (II) when the unevenness of the molded body and the drawing are deep, and when the drawing is shallow, the preforming step is unnecessary (III). The method is preferably taken. The method (IV) is preferably used for purposes other than mass production because a heating mechanism must be provided in the mold itself.

The step (B1) of the production method (I) and the production method (II), so-called vacuum forming (hereinafter sometimes referred to as “preliminary forming”) will be described.
First, the decorative sheet is heated to the softening temperature. As a method for heating the decorative sheet, a heater heated to about 300 ° C. is provided near the decorative sheet, and the decorative sheet is heated by radiant heat, or both sides of the decorative sheet are heated with a heated metal plate. There are a method of sandwiching and heating, a method of heating by heating a metal plate only on one side of the decorative sheet, and the like.
Next, the mold is pressed against the heated and softened decorative sheet. A vacuum suction mechanism is provided in the mold, and air is sucked in with a vacuum pump or the like so that the decorative sheet is firmly attached to the mold (vacuum suction), or compressed air is sent from the side opposite to the side where the mold is placed, A method of pressing the decorative sheet against the mold and bringing it into close contact (pressured air pressing), or a method of using both vacuum suction and pressured air pressing may be used.
After the decorative sheet is in close contact with the mold, the decorative sheet to which the mold shape has been transferred is removed from the mold.
In performing the above operation, the decorative sheet may be appropriately fixed with a fixed frame or the like. The temperature at which the vacuum forming is performed can be appropriately selected depending on the resin forming the sheet base material, but the temperature is about 10 to 50 ° C. higher than the glass transition temperature of the resin forming the sheet base material. It is common.
The decorative sheet obtained by the above-described vacuum forming (process (B1)) needs to have a thickness that can retain the shape for the convenience of disposing in the mold in the subsequent process. Therefore, the thickness of the decorative sheet to which the mold shape has been transferred depends on the resin forming the sheet substrate, but is preferably 100 to 500 μm.

Next, step (B2) of the production method (II) will be described with reference to FIG.
(I) The decorative sheet 20 is placed in the mold 42.
(Ii) The mold 42 is closed with the mold 52 provided with the resin gate 50 on the injection machine 48 side, and the resin material 54 heated and melted from the resin gate 50 is injected into the mold.
(Iii) The mold 42 and the mold 52 are opened to obtain a decorative resin molded body 56.
The method of disposing the decorative sheet (i) in the mold is different depending on the shape of the molded body. However, when the molten resin material is injected, the decorative sheet that is preformed, that is, the above-described method is used. It is necessary to fix the decorative sheet (hereinafter sometimes referred to as “preliminary molded body”) to which the mold shape of the mold is transferred so as not to swing. In addition, the preform is generally molded slightly smaller for convenience of placement in the mold. Since the decorative sheet is stretched at the time of injection molding, and the pattern and the like may be distorted, the shape and arrangement method of the preform and the mold belong to the know-how of each molding manufacturer.
The method of (ii) closing the mold and performing injection molding is not significantly different from general injection molding conditions. However, when the preform is thin, or when the preform has unevenness in the thickness of the preform, the preform may be broken by the injection pressure of the resin material. Moreover, the fine concavo-convex structure may be cracked by the injection pressure of the resin. Although pre-molding is performed in a sufficiently heated state, when a decorative resin molded body is manufactured by integrally molding a pre-molded body and a resin material, it can be heated only to the temperature of the mold and sufficiently This is because the resin material is stretched without being softened. In this respect, it is desirable that the toughness of the fine concavo-convex structure is high. The size of the gap between the molds, that is, the thickness of the molded body and the way of providing the resin gate should be appropriately designed in consideration of the desired shape of the molded body, the thickness of the decorative sheet, and the like. Resin supply amount, holding pressure after injection, and the like are not significantly different from general injection molding conditions, and are appropriately adjusted.
The opening of the mold (iii) and the removal of the molded body are preferably performed after appropriately setting the cooling time of the molded body as in general injection molding. The molding temperature, mold temperature, and cooling time are appropriately set depending on the resin material to be injected.

Production method (III) is not greatly different from step (B2) of production method (II). In general, the following steps are performed.
The manufacturing method (III) includes the step (C1) of placing the side on which the fine concavo-convex structure is formed in contact with the injection mold, and heating the decorative sheet in the injection mold, After pressing the mold along the inner surface of the injection mold, the mold is closed, and a molten resin material is injected into the mold and solidified to form a molding substrate made of the resin material, and fine irregularities And a step (C2) of obtaining a decorative resin molded product having a decorative sheet in which the surface opposite to the side on which the structure is formed is in contact with the molding substrate.
Specifically, a step (C1-1) for feeding the roll-shaped decorative sheet between the opened molds, a step (C2-1) in which the heater is lowered, and the decorative sheet is sufficiently heated and softened. The heater is raised, and the process of forming the decorative sheet in close contact with the mold by vacuum suction from the mold side (C2-2), and the process of closing the mold and injecting the molten resin material ( C2-3) and a manufacturing method including a step (C2-4) of opening a mold, cutting (trimming) the decorated resin molded body, and taking out the decorated resin molded body. Trimming may be performed before mold closing or may be performed before mold opening.
The production method (III) is superior in productivity to the production method (II) because the preforming step and the placement step (i) in the mold are unnecessary. On the other hand, it is difficult to obtain a molded body having a deeply drawn shape. Further, in the production method (III), a method of supplying a decorative sheet from a roll provided on the upper part of an injection mold is generally used. Therefore, the thickness of the decorative sheet is thin for convenience of winding around the roll. Is preferred.

  Although the manufacturing method (IV) is similar to the manufacturing method (I), the decorative sheet is not heated, but a mold having a shape is heated, and the heated mold is pressed against the decorative sheet. The manufacturing method (IV) is the same method as the marking. In the production method (IV), a decorative sheet is fixed with a frame or the like, and a heated mold is pressed against it. Then, in order to remove from a type | mold, a molded object can be obtained by cooling suitably and peeling from a type | mold.

  In the manufacturing method of the decorative resin molded body of the present invention described above, since the decorative sheet including the fine concavo-convex structure of the present invention is used, even if the three-dimensional molding as described above is performed, the reflection is performed. It is possible to obtain a decorated resin molded article that is excellent in design properties, scratch resistance, and the like without deteriorating the prevention performance.

  Examples of the present invention will be shown and described in detail below. In the following description, “parts” means “parts by mass” unless otherwise specified. Various measurements and evaluation methods are as follows.

(1) Measurement of mold protrusion:
A vertical section of a part of the mold provided with a fine convex structure obtained by transferring from a mother mold made of anodized porous alumina was subjected to Pt deposition for 1 minute, and a field emission scanning electron microscope (trade name JSM, manufactured by JEOL Ltd.). -7400F) was observed at an accelerating voltage of 3.00 kV, and the interval (cycle) between adjacent convex portions and the height of the convex portions were measured. Specifically, 10 points were measured for each, and the average value was taken as the measured value.
(2) Measurement of concave portion of fine concavo-convex structure:
A vertical cross section of the fine concavo-convex structure was deposited by Pt for 10 minutes, and the distance between adjacent dents and the depth of the dents were measured using the same apparatus and conditions as in (1) above. Specifically, 10 points were measured for each, and the average value was taken as the measured value.
(3) Tensile test of cured product of curable composition forming fine concavo-convex structure A dumbbell specimen having a distance between marked lines of 10 mm is punched out from a cured product having a thickness of about 200 μm at 80 ° C. A tensile test was performed. Breaking elongation and toughness were calculated.
(4) Visual observation of the decorative sheet (after stretching)
The decorative sheet obtained by transferring the mold was visually observed in a state stretched by 20% at 180 ° C.
Good: There are no fine cracks in the fine concavo-convex structure and no lifting from the sheet base material. Crack: There are wrinkles and cracks that can be visually observed. (5) Evaluation of the reflectance of the decorative sheet A mold having a fine convex structure. The reflectance of the sheet surface in the state which heated the decorative sheet obtained by transcription | transfer at 180 degreeC, and the state extended | stretched 10% and 20% at 180 degreeC was measured. A surface of the fine concavo-convex structure opposite to the fine concavo-convex structure side was roughened with sandpaper (GRIT No. 500), and then a black sample was applied to a spectrophotometer (U-4100, manufactured by Hitachi, Ltd.). ) Was used to measure the relative reflectance between wavelengths of 380 and 780 nm under the condition of an incident angle of 5 °.

(Mother mold production)
In accordance with the process shown in FIG. 3, a mother mold 40 (depth 180 nm) was produced as follows.
Lump aluminum having a purity of 99.97% by mass was cut into a roll having a diameter of 200 mm and a width of 320 mm, and the surface was cut into a mirror surface, which was used as the aluminum substrate 30.
Step (a):
The temperature of 0.05 M oxalic acid aqueous solution was adjusted to 15.7 ° C., and the aluminum base material 30 was immersed in this, and anodized under the following conditions.
Anodization was started at a voltage of 40 V while limiting the current so that the current density immediately after the start of voltage application was 19.9 mA / cm ² . Anodization was performed while maintaining a voltage of 40 V for 30 minutes, and then the voltage was increased to 80 V and anodization was performed at 80 V for 4.5 minutes to form an oxide film 32 having pores 31.

Step (b):
The aluminum substrate 30 on which the oxide film 32 is formed is immersed in a 70 ° C. aqueous solution in which 6% by mass of phosphoric acid and 1.8% by mass of chromic acid are mixed for 3 hours to dissolve and remove the oxide film 32. The depression 33 that becomes the pore generation point of the anodic oxidation was exposed.

Step (c):
The aluminum base material 30 with the pore generation points exposed is immersed in a 0.05M oxalic acid aqueous solution adjusted to 15.7 ° C. and anodized at 80 V for 11 seconds to form an oxide film 34 having pores 35. Was formed again on the surface of the aluminum substrate 30.

Step (d):
The aluminum base material 30 on which the oxide film 34 is formed is immersed in a 5% by mass phosphoric acid aqueous solution whose temperature is adjusted to 31.7 ° C. for 17 minutes, and subjected to a pore diameter expansion process for expanding the pores 35 of the oxide film 34. did.

Step (e):
The step (c) and the step (d) were further alternately repeated 4 times. Finally, step (d) was performed. That is, the process (c) was performed 5 times in total, and the process (d) was performed 5 times in total.

Thereafter, the mold 40 is cleaned with deionized water, and further, moisture on the surface is removed by air blow to obtain a mold 40 on which an oxide film 34 having substantially conical pores 35 having an average interval of 180 nm and an average depth of about 180 nm is formed. It was.
The mold thus obtained was subjected to mold release treatment by immersing it in an aqueous solution obtained by diluting TDP-8 (manufactured by Nikko Chemicals Co., Ltd.) to 0.1 mass% for 10 minutes and air drying overnight.

(Production of replica mold)
A replica mold (height 180 nm) was produced as follows.
85 parts of ethoxylated pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK ester ATM-4E), 8 parts of lauryl acrylate (trade name Blemmer LA, manufactured by NOF Corporation), 7 parts of methyl acrylate, active energy ray polymerization As an initiator, 0.5 part of 1-hydroxycyclohexyl phenyl ketone (trade name IRGACURE 184, manufactured by BASF Japan Ltd.), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (trade name DAROCURE TPO, manufactured by Ciba Geigy Japan) 1.0 part and 0.5 part of an internal mold release agent (manufactured by Nikko Chemicals, trade name NIKKOL TDP-2) were mixed to prepare an active energy ray-curable composition.
This active energy ray-curable composition was adjusted to 50 ° C. and poured onto the surface of the mother mold having the pores formed at 50 ° C., and a 38 μm thick polyethylene terephthalate film (manufactured by Mitsubishi Plastics) The product name WE97A) was coated while being spread. Thereafter, the curable composition was cured by irradiating ultraviolet rays from the film side using a fusion lamp so as to obtain an integrated light quantity of 1000 mJ / cm ² . Subsequently, the film and the mother mold were peeled off to obtain a replica mold having a fine convex structure on the surface.
The uneven structure of the mother mold is transferred to the surface of the replica mold. As shown in FIG. 1A, the interval w ₁ between the adjacent protrusions 13 is 180 nm, and the height d ₁ of the protrusions 13 is as follows. A fine concavity and convexity structure having a substantially conical shape of 180 nm was formed.

<Example 1>
(Preparation of curable composition)
60 parts of urethane acrylate (trade name EBECRYL8402 manufactured by Daicel-Cytec), 40 parts of benzyl acrylate, and 1.0 part of 1-hydroxycyclohexyl phenyl ketone (trade name IRGACURE 184, manufactured by BASF Japan Ltd.) as an active energy ray polymerization initiator 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (product name DAROCURE TPO, manufactured by Nippon Ciba-Geigy Co., Ltd.) (0.1 part) was mixed to prepare an active energy ray-curable composition.

(Manufacture of decorative sheets)
The active energy ray-curable composition was poured onto the surface of the replica mold where the convex portions were formed, and a 500 μm-thick polycarbonate sheet (manufactured by Teijin, Panlite PC1151) was applied on the surface of the replica mold. Then, the ultraviolet-ray was irradiated using the fusion lamp from the polycarbonate sheet side so that the integrated light quantity might be 1000 mJ / cm < ² >, and the curable composition was hardened. Subsequently, the sheet | seat and the replica mold were peeled and the decorating sheet containing the fine concavo-convex structure body which has a fine concavo-convex structure on the surface was obtained.
On the surface of the fine concavo-convex structure, the fine concavo-convex structure of the replica mold is transferred. As shown in FIG. 1A, the interval w ₁ between the adjacent concave portions 14 is 180 nm, and the depth d _{1 of the} concave portions 14 is. A fine concavity and convexity structure having a substantially conical shape of 180 nm was formed. Moreover, evaluation was implemented about the decorating sheet containing this fine concavo-convex structure. The results are shown in Table 1.

<Examples 2 to 11 and Comparative Examples 1 to 5>
A decorative sheet of the same size was produced and evaluated in the same manner as in Example 1 except that the monomer and initiator were changed to those shown in Table 1. The results are shown in Tables 1 and 2. The unit of the blending amount in each table is “part”.

Abbreviations in the table are as follows.
(Monofunctional monomer (X))
X-1: benzyl acrylate X-2: methyl acrylate X-3: terminal methoxylated polyethylene glycol monoacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK ester AM130G)
X-4: 2-hydroxyethyl acrylate (bifunctional monomer (Y))
Y-1: Bifunctional urethane (meth) acrylate (manufactured by Daicel-Cytec, trade name: EBECRYL8402, Mw = 1000)
Y-2: Polyethylene glycol diacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M260, Mw = 698)
Y-3: Bifunctional urethane (meth) acrylate (Daiichi Kogyo Seiyaku Co., Ltd., trade name: New Frontier R-1214, Mw = 600 or more)
(Polyfunctional monomer (Z) having three or more functional groups)
・ Z-1: Trifunctional urethane (meth) acrylate (manufactured by Daicel-Cytec, trade name: EBECRYL 8465, Mw = 1400, Mw / number of polymerizable functional groups = 467)
Z-2: Ethoxylated pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK ester ATM-35E, Mw = 1892, Mw / number of polymerizable functional groups = 473)
(Other monomer (H))
H-1: 1,6-hexanediol diacrylate (bifunctional monomer, Mw = 226)
H-2: Ethoxylated pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK ester ATM-4E, Mw = 528, Mw / number of polymerizable functional groups = 132)
H-3: Dipentaerythritol hexaacrylate (polyfunctional monomer, Mw = 578, Mw / number of polymerizable functional groups = 96)
(Polymerization initiator)
"IRG 184": 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Japan, trade name IRGACURE 184)
"DAR TPO": 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by Ciba Geigy Japan, trade name: DAROCURE TPO)

As is clear from the results shown in Tables 1 and 2, the decorative sheet including the fine concavo-convex structure of the present invention in each example uses a curable composition having good elongation, and therefore stretched by 20%. However, Comparative Examples 1 to 4 in which cracks did not occur are one or more selected from the group consisting of the monofunctional monomer (X), the bifunctional monomer (Y), and the polyfunctional monomer (Z) of the present application. The monomer is not contained in an amount of 70 parts by mass or more with respect to 100 parts by mass of the curable component, and more than 30 parts by mass of a monomer having a value obtained by dividing the mass average molecular weight by the number of polymerizable functional groups is 300 or less. As a result, the cross-linked density of the cured product increased and could not withstand elongation. In Comparative Example 5, 20 parts by mass of a monomer having an extremely high crosslink density having a value obtained by dividing Mw by the number of polymerizable functional groups is 100 or less, so that the tensile elongation at break of the cured product is low and cracks are caused by stretching. I have.
When the samples of the decorative sheets of Comparative Examples 1 to 5 that were visually cracked were magnified and observed, the base material was not damaged by stretching, but the cured resin film was not able to withstand elongation, and was ruptured. It was lifted from the substrate.

<Example 12>
A decorative sheet of the same size was produced and evaluated in the same manner as in Example 11 except that the polycarbonate sheet having a thickness of 500 μm was changed to an acrylic film having a thickness of 200 μm (manufactured by Mitsubishi Rayon, acrylprene HBK003).
The curable composition of Example 11 adhered well to the acrylic film and could be stretched together with the acrylic film.

<Example 13>
The decorative sheet obtained in Example 3 was heated at 180 ° C. Then, 10% and 20% stretching was performed at 180 ° C. using a stretching machine. The surface reflectance of the unstretched, 10% stretched, and 20% stretched sheets was measured.
With 10% and 20% stretching, the reflectance spectral curve did not change significantly compared to unstretched ones. The reflectance at 550 nm, which is considered to have the highest visual sensitivity, was 0.059, 0.068, and 0.083 for unstretched, 10% stretched, and 20% stretched, respectively.
It was found that as the film was further stretched, the reflectance on the long wavelength side increased, and the color of the reflected light became reddish.

(Manufacture of decorative resin moldings)
Moreover, integral molding with an acrylic resin was performed using the obtained decorative sheet.
An injection mold for preparing a molded body having a curvature radius of 200 mm and curved in one axis direction was prepared. A side gate is provided at the center of the curved shape and has a cavity that warps the movable side of the mold. (Male side (convex surface) of mold is movable side, female side (concave surface) is fixed side)
The decorative sheet containing the fine concavo-convex structure was loosely fixed in the mold with a double-sided tape so that the fine concavo-convex structure side of the decorative sheet was in contact with the mold on the male side of the mold. The mold was temperature-controlled at 60 ° C. As the resin material, Mitsubishi Rayon Acrypet VH001 was used. The injection temperature was 250 ° C.
After injection molding, the mold was opened and the molded product that had been attached to the mold with double-sided tape was taken out. The acrylic substrate and the resin material were in close contact with each other, and the fine uneven structure was integrated on the surface of the molded product. Thus, a decorative resin molded body having a curved surface with antireflection performance was obtained.

  The decorative sheet including the fine concavo-convex structure of the present invention having a fine concavo-convex structure on the surface has high moldability while maintaining excellent optical performance, and thus is not limited to displays and the like that require antireflection performance. It can also be applied to uses such as window materials and front plates of automobiles, trains, ships, etc. having complicated shapes.

DESCRIPTION OF SYMBOLS 10 Fine uneven structure 11 Base material 12 Hardened | cured material 13 Convex part 13a Top part of convex part 14 Concave part 14a, 14b Bottom part of concave part 15 Intermediate | middle layer 20 Decorating sheet 22 Sheet base material 40 Mold 30 Aluminum plate 31 Crack 32 Oxide film 33 Dimple 34 Oxide film 35 Pore 42, 52 Mold 48 Injection machine 50 Resin gate 54 Resin material 56 Decorated resin molding

Claims (12)

A fine uneven structure having a fine uneven structure on the surface,
It consists of a cured product of a curable composition,
Ri der tensile elongation at break at least 20% of said cured product,
The curable composition cures at least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups. 70 parts by mass or more with respect to 100 parts by mass of the sexual component,
The bifunctional monomer (Y) has a mass average molecular weight of 600 or more,
The fine concavo-convex structure body whose value which remove | divided the mass mean molecular weight of the said polyfunctional monomer (Z) by the number of polymerizable functional groups is 300 or more . The fine concavo-convex structure according to claim 1, wherein a toughness of the cured product in a tensile test at 80 ° C is 1 kJ / m ² or more. The bifunctional monomer (Y) is at least one bifunctional acrylate selected from the group consisting of a bifunctional urethane (meth) acrylate and a bifunctional polyether (meth) acrylate,
The polyfunctional monomer (Z) is one or more polyfunctional acrylates selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate,
The fine concavo-convex structure according to claim 1 or 2, wherein a total amount of the bifunctional acrylate and the polyfunctional acrylate is 30 parts by mass or more with respect to 100 parts by mass of the curable component. The decorating sheet containing the fine concavo-convex structure as described in any one of Claims 1-3. A decorative resin molding comprising the decorative sheet according to claim 4 . The member for vehicles containing the decorating resin molding of Claim 5 . A display member comprising the decorative resin molded body according to claim 5 . It is a manufacturing method of the fine concavo-convex structure according to claim 1 ,
Between the surface of the mold having a fine convex structure on the surface and the substrate, the following curable composition (i) or curable composition (ii) is disposed, and after curing the curable composition, The manufacturing method of a fine concavo-convex structure including the process of peeling the said mold.
Curable composition (i): at least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups, Including 70 parts by mass or more with respect to 100 parts by mass of the curable component,
The bifunctional monomer (Y) has a mass average molecular weight of 600 or more,
The value obtained by dividing the mass average molecular weight of the polyfunctional monomer (Z) by the number of polymerizable functional groups is 300 or more.
Curable composition (ii): at least one monomer selected from the group consisting of a monofunctional monomer (X), a bifunctional monomer (Y), and a polyfunctional monomer (Z) having three or more functional groups, Including 70 parts by mass or more with respect to 100 parts by mass of the curable component,
The bifunctional monomer (Y) has a mass average molecular weight of 600 or more,
The value obtained by dividing the weight average molecular weight of the polyfunctional monomer (Z) by the number of polymerizable functional groups is 300 or more,
The bifunctional monomer (Y) is at least one bifunctional acrylate selected from the group consisting of a bifunctional urethane (meth) acrylate and a bifunctional polyether (meth) acrylate,
The polyfunctional monomer (Z) is one or more polyfunctional acrylates selected from the group consisting of a trifunctional or higher functional urethane (meth) acrylate and a trifunctional or higher functional polyether (meth) acrylate,
The total amount of the bifunctional acrylate and the polyfunctional acrylate is 30 parts by mass or more with respect to 100 parts by mass of the curable component. The process of obtaining the decorating resin molding which presses against the type | mold by heating the decorating sheet of Claim 4, and vacuuming the heated decorating sheet, or sending compressed air, and having a fine uneven structure on the surface The manufacturing method of the decorative resin molding which has the fine concavo-convex structure on the surface containing (A1). A method for producing a decorative resin molded body having a fine concavo-convex structure on the surface,
5. The decorative sheet on which the mold shape is transferred by pressing the mold while heating the decorative sheet according to claim 4 , transferring the mold shape, taking out the decorative sheet after transferring the mold shape, and transferring the mold shape. (B1) to obtain
The decorative sheet obtained in the step (B1) is arranged so that the side on which the fine concavo-convex structure is formed is in contact with the injection mold surface, and the molten resin material is placed in the injection mold. A step of obtaining a decorated resin molded body having a molded base material made of a resin material and a decorative sheet in which the surface opposite to the side where the fine concavo-convex structure is formed is in contact with the molded base material by injection and solidification The manufacturing method of the decorative resin molding which has the fine concavo-convex structure on the surface containing (B2). A method for producing a decorative resin molded body having a fine concavo-convex structure on the surface,
A step (C1) of disposing the decorative sheet according to claim 4 so that the side on which the fine concavo-convex structure is formed is in contact with the injection mold,
While heating the decorative sheet in the injection mold, after pressing the mold along the inner surface of the injection mold, the mold is closed, and the resin material in a molten state in the mold Are injected and solidified to obtain a decorative resin molded body having a molded base material made of a resin material and a decorative sheet whose surface opposite to the side on which the fine concavo-convex structure is formed is in contact with the molded base material The manufacturing method of the decorative resin molding which has a fine uneven structure on the surface including a process (C2). The surface of the fine concavo-convex structure including the step (D1) of pressing a heated mold onto the decorative sheet according to claim 4 to transfer the shape of the mold and obtaining a decorative resin molded body having a fine concavo-convex structure on the surface. The manufacturing method of the decorative resin molding which it has in.

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