JP2002205317A - Reflection preventing molding, its production method, and mold for the molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection preventing molding having an excellent reflection preventing effects and hard coat properties, a method for producing the molding, and a mold for the molding. SOLUTION: A decorative sheet 9 in which at least a hard coat layer is formed on a substrate sheet 7 is arranged so that the substrate sheet 7 contacts the cavity surface of a mold 10 in which a place corresponding to a transparent window is a curved surface at least 40 mm in radius of curvature or a plane surface, and a transparent molten resin is injected into the mold 10 to obtain an object in which the decorative sheet 9 and a transparent resin base material 1 are integrated. Next, the substrate sheet 7 is peeled off from the object, and a curved surface 2.0-150 nm in average surface roughness Ra which is protruded to the surface side and in which the radius of curvature of a transparent window part is at least 40 mm or a plane surface is formed in a place to be the transparent window. Next, a reflection preventing layer 5 is formed on the surface side of the transparent base material 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a portable telephone, a video camera, a digital camera, an automobile device, a PDA (P
personal Digital Assistan
t), monitors for personal computers, electronic paper as electronic devices for display that are light and thin and flexible like paper, various displays such as televisions, various electronic devices such as electronic devices for outdoor signage, and various types of devices other than electronic devices. Display members,
For example, an anti-reflection molded product used to allow a transparent display (a member having a function as a display screen) to be seen through an outdoor display panel, a picture frame, a picture frame, a clock, a window glass, and the like. The present invention relates to a manufacturing method and a mold for an antireflection molded product.

[0002]

2. Description of the Related Art In a mobile phone, a video camera, a digital camera, an automobile device, etc., a display portion is
It is configured by a combination with a liquid crystal panel or an organic EL panel. The display is formed with a pattern such as a transparent substrate or a border molded into a convex lens shape to prevent damage to the liquid crystal panel, enlarge the display of the liquid crystal panel, and decorate the vicinity of the liquid crystal panel Covered by a cover component made of a transparent base material.

[0003] The transparent window portion of the cover part as described above,
In order to make the displayed screen easier to see, anti-glare properties are required. Further, a hard coat property excellent in scratch resistance, chemical resistance, weather resistance, and the like is required. Therefore, there is a method of forming an anti-reflection layer using the interference between Fresnel reflection and light.

In this case, it is extremely important to control the thickness of the antireflection layer. When the thickness is 1/4 wavelength, the reflected light from the film surface and the reflected light from the film / substrate interface cancel each other. Therefore, the reflectance is reduced, and the anti-reflection effect is most exhibited.
For example, in the case of an anti-reflection layer having a refractive index of 1.36, when the center wavelength of transmitted light is 550 nm, the thickness of the anti-reflection layer is optimally about 0.1 μm.

[0005]

However, it is very difficult to form such a thin antireflection layer on a transparent substrate with a uniform thickness, and it is difficult to obtain the expected antireflection effect. There was a problem. In particular, when the entire shape of the transparent base material is a three-dimensional shape, it is very difficult to form a thin film with a uniform thickness thereon, and it is difficult to obtain the expected antireflection effect.

Further, the above-described antireflection layer has a problem in that the hard coat property is poor.

Accordingly, the present invention is to provide an anti-reflective molded product having an excellent anti-reflection effect and a hard coat property, a method of manufacturing the same, and a mold for the anti-reflective molded product, which solves the above-mentioned disadvantages. With the goal.

[0008]

Means for Solving the Problems The anti-reflective molded product, the method for manufacturing the same and the mold for the anti-reflective molded product according to the present invention are constituted as follows in order to achieve the above object.

That is, in the method for producing an antireflection molded product according to the present invention, a decorative sheet having at least a hard coat layer formed on a base sheet is formed by forming a curved or flat surface having a curvature radius of 40 mm or more at a portion corresponding to a transparent window. The base sheet is placed so that the base sheet side is in contact with the cavity surface of the mold that is the surface, and a transparent molten resin is injected into the mold to obtain an integrated product of the decorative sheet and the transparent base made of resin. Is formed from the above-mentioned integrated material to form a curved surface or a flat surface having an average surface roughness Ra of 2.0 to 150 nm and a radius of curvature of 40 mm or more in the transparent window portion. Then, an anti-reflection layer was formed on the surface side of the transparent substrate.

Further, a decorative sheet having at least a hard coat layer formed on a base sheet is provided on a cavity surface of a mold having a curved surface or a flat surface with a curvature radius of 40 mm or more at a portion corresponding to a transparent window. The transparent surface is placed so that the sides are in contact with each other, and a transparent molten resin is injected into the mold to obtain an integrated product of the decorative sheet and the transparent base material made of the resin. 0-150 nm
In this configuration, a curved surface or a flat surface having a curvature radius of 40 mm or more where the shape of the transparent window portion is convex on the front surface side is formed, and then an antireflection layer is formed on the front surface side of the transparent base material.

[0011] In the above invention, the decorative sheet may have at least a hard coat layer, a partial pattern layer except for a portion to be a transparent window, and an entire adhesive layer on the base sheet. May be formed.

Further, in the above invention, an antifouling layer may be formed on the antireflection layer.

Further, in the mold for an antireflection molded product according to the present invention, at least a hard coat layer is disposed on the surface of the transparent substrate, and the average surface roughness Ra of the transparent window is 2.0 to 4.0.
150 nm and a radius of curvature of 40 in the transparent window portion.
In a mold for molding an antireflection molded product having a curved surface or a flat surface that is convex on the surface side of at least mm, a radius of curvature at a portion corresponding to a transparent window has a cavity surface that is a curved surface or a flat surface of 40 mm or more. Configured.

Further, in the above invention, the average surface roughness Ra of the cavity surface at a position corresponding to the transparent window is 2.0 to 2.0.
It may be configured to be 170 nm.

Further, the antireflection molded article of the present invention has at least an antireflection layer formed on the surface of a transparent substrate, and has an average surface roughness Ra at the interface of the transparent window on which the antireflection layer is formed.
Is 2.0 to 150 nm, and the surface of the transparent window has a curved surface or a flat surface having a radius of curvature of 40 mm or more.

Further, in the above invention, a configuration may be made such that a partial pattern layer of a pattern excluding a portion serving as a transparent window is formed between the transparent substrate and the antireflection layer.

Further, in the above invention, a configuration may be such that a hard coat layer is formed between the transparent substrate and the antireflection layer.

Further, in the above invention, an antifouling layer may be formed on the antireflection layer.

Further, in the above invention, the average surface roughness Ra is 2.0 to 2.0 in the visible area of the transparent window.
35 nm, and the average surface roughness Ra is 35 to 85 nm in the surrounding area around the viewing area of the transparent window.
May be configured.

[0020]

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of an antireflection molded product according to the present invention. FIG. 2 is a cross-sectional view showing one embodiment of a decorative sheet used in the method for manufacturing an antireflection molded product according to the present invention. 3 to 5 are cross-sectional views showing one step of the method for manufacturing an antireflection molded product according to the present invention. FIG. 6 is a cross-sectional view showing one embodiment of a decorative sheet used in the method for manufacturing an antireflection molded product according to the present invention. 7 and 8 are sectional views showing one step of the method for manufacturing an antireflection molded product according to the present invention. FIG. 9 is a graph for obtaining the average surface roughness Ra in the present invention. FIG. 10 is a sectional view showing an embodiment of the mold for an antireflection molded product according to the present invention. FIG.
It is sectional drawing which shows one Example of the antireflection molded article of this invention. FIG. 12 is a sectional view showing an embodiment of the antireflection molded product of the present invention. FIG. 13 is a schematic cross-sectional view showing how the antireflection effect changes when the average surface roughness Ra differs. FIG. 14 is a table showing the relationship between the use of the antireflection molded product of the present invention, the reflectance, and the average surface roughness Ra. FIG. 15 is a perspective view showing an embodiment of the antireflection molded product of the present invention. FIG. 16 is a sectional view showing one embodiment of the antireflection molded product of the present invention. FIG. 17 is a sectional view showing one embodiment of a molding die used in the method for producing an antireflection molded product according to the present invention. In the figure, 1 is a transparent substrate, 2
Is an adhesive layer, 3 is a release layer, 4 is a hard coat layer, 5 is an antireflection layer, 7 is a base sheet, 8 is an antireflection molded product, 9 is a decorative sheet, 10 is a mold, 11 is a design layer, 12 is an antifouling layer,
13 is a molten resin.

The method for manufacturing an anti-reflection molded product 8 of the present invention is characterized in that a decorative sheet 9 having at least a hard coat layer 4 formed on a base sheet 7 is provided on a curved surface having a radius of curvature of 40 mm or more at a location corresponding to a transparent window. Alternatively, the base sheet 7 is placed so as to be in contact with the cavity surface of the mold 10 which is a flat surface, and a transparent molten resin is injected into the mold 10 to integrate the decorative sheet 9 with the transparent substrate 1 made of resin. And then the base sheet 7 is peeled from the above-mentioned integrated body to form a transparent window, where the average surface roughness Ra is 2.0 to 150 nm, and the radius of curvature of the transparent window portion is 40 mm or more. Is formed, and then the antireflection layer 5 is formed on the surface side of the transparent substrate 1 (see FIG. 1).

In the present invention, the average surface roughness Ra at the interface of the transparent window portion where the antireflection layer 5 is formed is 2.0 to 150 n.
It is important that the transparent window has a curved surface or a flat surface with a radius of curvature of 40 mm or more.

In order to form the anti-reflection layer 5 with a uniform thickness, it was tested how much less the average surface roughness Ra of the molded product surface should be. Molds 10 having various types of graining on the surface are produced to produce molded products having various average surface roughnesses Ra, and are manufactured according to Japanese Industrial Standard (JIS) B06.
The average surface roughness Ra was measured with a measuring instrument (F3500D, manufactured by Kosaka Laboratories, Inc.) according to 01-1994. In addition, JIS B0601 includes ISO468: 82,
3274: 75, 4287-1: 84, 4287-2:
84, 4288: 85 correspond. Thereafter, the antireflection layer 5 was formed under the same conditions, and the reflectance at 550 nm was measured with a spectrophotometer. When the antireflection effect of each molded product was measured in this way, as shown in Table 1, it was found that the antireflection effect could be obtained if the average surface roughness Ra of the molded product surface was 150 nm or less. More preferably, it is 80 nm or less.

Further, it is very difficult to produce an average surface roughness Ra of less than 2.0 nm.
It was also found that the thickness tolerance of the anti-reflection layer 5 and the reflectance of the anti-reflection molded article 8 produced by the same were hardly changed even when the thickness was 35 nm or less. Here, the reflectance is a numerical value obtained by the measuring method of ISO / DIS13406-2.

FIGS. 13A to 13C show the average surface roughness R.
It is a schematic cross section showing how antireflection effect changes when a differs. The antireflection layer 5 has a thickness of 10
It was formed to have a thickness of 0 nm. For example, when the average surface roughness Ra is 5 nm (see FIG. 13A), the thickness of the antireflection layer 5 is almost constant, and the reflected light α and α ′ and the reflected light β and β ′ are moderate. Of the antireflection layer 5
A uniform and excellent antireflection effect can be obtained as a whole. When the average surface roughness Ra is 150 nm (see FIG. 13B), the thickness of the antireflection layer 5 partially varies, and the reflected light α and α ′ and the reflected light β and β ′ The degree of interference may be different, and the anti-reflection layer 5
In some cases, the antireflection effect tends to decrease locally. When the average surface roughness Ra is 400 nm (see FIG. 13C), the thickness of the antireflection layer 5 becomes non-uniform, and both the reflected light α and α ′ and the reflected light β and β ′ No interference occurs, and no antireflection effect can be obtained in the entire antireflection layer 5.

Further, as shown in FIG. 14, the required reflectance differs depending on the use of the antireflection molded product 8, so that
Accordingly, it is necessary to appropriately select the range of the average surface roughness Ra.

In general, an antireflection molded article for an application that is frequently watched needs a more excellent antireflection effect,
It is desirable to reduce the average surface roughness Ra. That is, when the frequency of gaze is high, a heavy load is imposed on the eyes of the viewer. If the reflection is low, the eyes are easy to see and the eyes are hardly tired. Therefore, if an excellent anti-reflection effect can be obtained, it is possible to realize prevention of eyestrain of a viewer. Therefore, when the frequency of gaze is high, it is preferable that the reflectance has a high antireflection property of 0.5% or less, and the value of the average surface roughness Ra is 90 nm or less.

Further, when the environment in which the antireflection molded article is used is outdoors, a superior antireflection effect is required as compared with the case where the antireflection molded article is used indoors, and the average surface roughness R
It is desirable to make a small. The reason why such an excellent anti-reflection effect is necessary is that, in the daytime, the outdoors are brighter than the indoors, and the sunlight is reflected on the surface of the display, making it difficult to see, and the outdoors have a better anti-reflection effect. Is necessary. For outdoor use,
The reflectivity is preferably 1.7% or less, and the value of the average surface roughness Ra is preferably 145 nm or less.

When an antireflection molded article is used by arranging it on the front surface of a display, a better antireflection effect is required when the display is color than when it is monochrome. It is desirable to reduce the average surface roughness Ra. On a color screen, when there are many reflections, the saturation of the display image becomes low as if the color of the display image was lost. As described above, since saturation is more important in a color screen than in a monochrome screen, a higher antireflection effect is required. In the case of a color screen, the reflectance is preferably 1.2% or less, and the value of the average surface roughness Ra is preferably 130 nm or less.

Depending on the use of the antireflection molded article 8, the surface may be divided into a region where an excellent antireflection function is particularly required and a region where no particular problem occurs even if the antireflection function is slightly lowered. In some cases, it can be classified. FIG.
FIG. 1 is a perspective view showing an antireflection molded product 8 having a size of 25 mm in length and 33 mm in width used for a full-color liquid crystal display section of a mobile phone as an example. In the antireflection molded article 8 for such an application, the central area A is an area where the antireflection function is particularly necessary since the user of the mobile phone is most closely watched, and the average surface roughness Ra is 2 to 35 nm. It is desirable to make. On the other hand, the peripheral region B around the periphery of the central region A
Is not an area that the user of the mobile phone gazes at, so a very high antireflection function is not required, and the Ra value is 35 to
Even if the thickness is about 85 nm, no particular problem occurs, and processing in the peripheral region B can be omitted as compared with the central region A, so that the overall cost can be reduced.

Further, the smaller the radius of curvature R of the surface shape of the antireflection molded product 8, the lower the necessity of the antireflection function. In addition, it is difficult to manufacture the molding die 10 by polishing the surface to reduce the surface roughness, or it is difficult to form the antireflection layer 5 with a uniform thickness. The nature also increases. Therefore, the antireflection molded product 8
In a region where the curvature radius R of the surface shape is small, the average surface roughness Ra is preferably reduced to, for example, about 85 to 140 nm. In addition, when there is no particular problem, the antireflection function may not be provided at all. For example, when the surface shape of the anti-reflection molded product 8 shown in FIG. 15 has the cross-sectional shape shown in FIG. 16, in a very small surrounding region B where the radius of curvature R is less than 40 mm, the user of the mobile phone is required. However, there is almost no possibility of watching the camera, and it is also difficult to provide a high antireflection function.

In the present invention, the average surface roughness Ra
As shown in FIG. 9, an average line was determined from the cross-sectional curve of the molded product surface, and the Gaussian filter (roughness curve = cross-sectional curve−
The average surface roughness Ra can be determined using the average line).

It is also important that the shape of the antireflection molded article 8 itself be such that the shape of the transparent window portion, which is a surface requiring an antireflection effect, is a curved surface having a radius of curvature of 40 mm or more or a flat surface. It is.

In order to form the anti-reflection layer 5 with a uniform thickness, it was examined how much the flatness of the molded article had to be made. As shown in Table 3, at least its surface had a curvature. It has been found that it is necessary to set the radius to a curved surface of 40 mm or more. It was also found that it is preferable to set the radius of curvature to a curved surface of 60 mm or more. That is, as shown in FIG. 12, a semi-cylindrical molded product having a radius of curvature of 30 to 300 mm is formed, and then an anti-reflection layer 5 made of MgF is formed to obtain an anti-reflection molded product 8 having an average reflection at 550 nm. The average reflectance was evaluated as good when the average reflectance was 3% or less, and extremely good when the average reflectance was 1% or less.

With the above construction, when the antireflection layer 5 is formed by coating with a low-viscosity paint, the paint moves from a high place to a low place and accumulates.
The thickness of the antireflection layer 5 can be prevented from becoming uneven.
In addition, when the antireflection layer 5 is formed by a vapor deposition method, it is possible to prevent the thickness of the antireflection layer 5 from becoming nonuniform due to the difference in the amount of deposition vapor per unit area depending on the location.

The radius of curvature referred to in the present invention refers to the radius of a circle obtained by obtaining an arc closest to the average line obtained by the above-mentioned roughness measuring instrument and extending the arc (see FIG. 9). When the value of the radius of curvature greatly differs depending on the measurement location, the average value of those values is used.

It is desirable that the surface of the antireflection molded product 8 has a hard coat property. Therefore, as shown in FIG. 1A, it is desirable to provide the hard coat layer 4 before forming the antireflection layer 5. .

As a method of forming the hard coat layer 4 on the surface of the transparent substrate 1, there are a method of directly applying a hard coat agent to the surface of the transparent substrate 1, and a simultaneous decoration method. In particular, in the simultaneous decorating method, the surface of the hard coat layer 4 can be finished to the shape of the cavity surface which is a mirror surface or a similar surface having few irregularities, and the irregularities can be considerably reduced. Further, in the simultaneous molding and decorating method, if the hard coat layer 4 is left uncured or semi-cured on the decorating sheet 9 and is cured after forming into a molded product, the mold 10
It is more preferable because it can be easily formed in the shape of the cavity surface and the occurrence of cracks during molding is reduced.

In order to provide the hard coat layer 4 and the like on the transparent substrate 1, it is preferable to use a simultaneous molding and decoration method using the decoration sheet 9. The simultaneous molding and decorating method includes a simultaneous molding and transferring method using a transfer material 9A as the decorative sheet 9 and an insert method using an insert material as the decorative sheet 9.

The molding simultaneous transfer method means a transfer material 9 in which a transfer layer composed of a hard coat layer 4 and the like is formed on a base sheet 7.
A is sandwiched in the mold 10 (see FIG. 3B), the molten resin 1A is injected into the mold 10, and after cooling to obtain the resin molded product, the transfer material 9A is adhered to the surface of the molded product (see FIG. 3B). 6), the base sheet 7 is peeled off, and the transfer layer is transferred to the surface of the resin molded product to perform decoration (see FIG. 7).

The insert method means that an insert material 9 having a hard coat layer 4 or the like formed on a base sheet 7 is molded into a mold 1.
In this method, a molten resin is injected into a mold 10 and cooled to obtain a resin molded product, and at the same time, decoration is performed by bonding an insert material 9 to the surface of the molded product.

First, the molding simultaneous transfer method using the transfer material 9A will be described.

The transfer material 9A has a structure in which a transfer layer including the hard coat layer 4 is provided on the base sheet 7 (see FIG. 6). As the transfer layer, instead of incorporating all the layers formed on the transparent substrate 1 of the antireflection molded product 8,
It is preferable that only a layer suitable for forming by the simultaneous molding transfer method is used as a transfer layer, and other layers are separately formed. In particular, the hard coat layer 4 and the design layer are suitable for being formed by a molding simultaneous transfer method.

The base sheet 7 may be made of a polypropylene resin, a polyethylene resin, a polyamide resin,
What is used as the base sheet 7 of the normal transfer material 9A, such as a resin sheet of a polyester resin, an acrylic resin, a polyvinyl chloride resin, or the like, can be used.

When the transfer layer has good releasability from the base sheet 7, the hard coat layer 4 can be provided directly on the base sheet 7. In order to improve the releasability of the transfer layer from the base sheet 7, the release layer 3 may be formed entirely before the hard coat layer 4 is provided on the base sheet 7 (see FIG. 6). In particular, by mixing silica beads or the like into the release layer 3, fine irregularities can be formed on the surface of the molded product when the base sheet 7 is peeled off (see FIG. 7).

Next, a hard coat layer 4 is formed. The hard coat layer 4 is a layer that increases the surface strength of the antireflection molded product 8 when the base sheet 7 is peeled off after the simultaneous transfer of the molding.

For the hard coat layer 4, a thermosetting resin, an ionizing radiation curable resin such as an ultraviolet ray or an electron beam, or the like can be used. An ultraviolet curable resin such as an acrylic urethane resin is frequently used.

The UV-curable resin includes a UV-curable acrylic urethane resin, a UV-curable polyester acrylate resin, a UV-curable epoxy acrylate resin and the like, and is used together with a photopolymerization initiator. For example, an ultraviolet-curable acrylic urethane-based resin is obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer, and reacting the obtained product with an acrylate or methacrylate-based monomer having a hydroxyl group. As the photopolymerization initiator, a benzophenone derivative, an acetophenone derivative, an anthraquinone derivative or the like can be used alone or in combination. A thermoplastic acrylic resin or the like may be appropriately selected and blended with the ultraviolet curable resin in order to further improve the film formation.

The method of forming the hard coat layer 4 includes a coating method such as a gravure coating method, a roll coating method and a comma coating method, and a printing method such as a gravure printing method and a screen printing method.

Further, the design layer 120 may be formed as required. The design layer 120 is a layer for decorating the antireflection molded product 8. The pattern layer 120 is a hard coat layer 4
On top of. The design layer 120 is usually formed as a printing layer. As the material of the printing layer, polyvinyl resin,
A resin such as polyamide resin, polyester resin, acrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester resin, or alkyd resin is used as a binder, and a pigment or dye of an appropriate color is used as a coloring agent. It is good to use a coloring ink containing as a. As a method for forming the printing layer, a normal printing method such as an offset printing method, a gravure printing method, or a screen printing method may be used. The printing layer is usually provided in a pattern excluding a portion that becomes a transparent window, and is partially provided so as to have a frame shape or a character shape.

The design layer 120 may be made of a metal thin film layer or a combination of a printing layer and a metal thin film layer. The metal thin film layer is for expressing metallic luster as the design layer 120, and is formed by a vacuum evaporation method,
It is formed by a sputtering method, an ion plating method, a plating method, or the like. Aluminum, nickel, gold, platinum, chromium, iron, copper, tin,
Use metals such as indium, silver, titanium, lead, zinc, and alloys or compounds thereof. The metal thin film layer is usually formed partially. Further, when providing the metal thin film layer, a front anchor layer or a rear anchor layer may be provided in order to improve the adhesion to other layers.

Further, an adhesive layer 2 may be formed on the transparent substrate 1 in order to adhere the above-mentioned layers (see FIGS. 6, 7 and 8). As the adhesive layer 2, a heat-sensitive or pressure-sensitive resin suitable for the material of the transparent substrate 1 is appropriately used.

For example, when the material of the transparent substrate 1 is an acrylic resin, an acrylic resin is preferably used. When the material of the transparent substrate 1 is a polyphenylene oxide / polystyrene resin, a polycarbonate resin, or a polystyrene blend resin, an acrylic resin, a polystyrene resin, a polyamide resin, or the like having an affinity for these resins is used. do it. Further, when the material of the transparent substrate 1 is a polypropylene resin, a chlorinated polyolefin resin,
Chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber,
Coumarone indene resin can be used. The method for forming the adhesive layer 2 includes a gravure coating method, a roll coating method,
There are a coating method such as a comma coating method and a printing method such as a gravure printing method and a screen printing method.

The structure of the transfer layer is not limited to the above embodiment. For example, when a material having excellent adhesiveness to the transparent substrate 1 is used as the material of the design layer 120, the adhesive layer 2 can be omitted.

The anti-reflection molded article 8 can be easily obtained by using the anti-reflection transfer material 9A having the structure described above and utilizing the transfer method.

First, the adhesive layer 2 side of the antireflection transfer material 9A is brought into close contact with the surface of the transparent substrate 1. Next, using a transfer machine such as a roll transfer machine equipped with a heat-resistant rubber-like elastic body such as silicon rubber or an up-down transfer machine, at a temperature of 80 to 260 ° C.
Heat and pressure are applied from the side of the base sheet 7 of the antireflection transfer material 9A via a heat-resistant rubber-like elastic body set at a pressure of about 490 to 1960 Pa. By doing so, the adhesive layer 2 adheres to the surface of the transparent substrate 1.

Finally, when the base sheet 7 is peeled off after cooling, peeling occurs at the interface between the base sheet 7 and the hard coat layer 4, and the transfer is completed. In the case where the release layer 3 is provided on the base sheet 7, when the base sheet 7 is peeled off, separation occurs at the boundary surface between the release layer 3 and the hard coat layer 4, and the transfer is completed (FIGS. 7 to 7). 8).

Next, a method of performing a molding simultaneous transfer method by injection molding using the antireflection transfer material 9A will be described.

As the molding die 10, the molding die 10
As the cavity surface 10A corresponding to the transparent window
In this method, a material having a curved surface or a flat surface with a radius of curvature of 40 mm or more is used. As the material of the molding die 10,
Rolled steel for structure, carbon steel for machine structure, carbon tool steel, alloy tool steel, high speed steel, high carbon chromium steel, bearing steel, nickel chromium molybdenum steel, chromium molybdenum steel, aluminum chromium molybdenum steel, etc. can be used. . The cavity 10B of the molding die 10 is formed by a processing method such as a milling method, a cold hobbing method, a show process method, a pressure casting method, an electroforming method, an electric discharge method, a corrosion processing method, and an NC processing method. Can be. Cavity surface 10A
Can be finished to a predetermined surface roughness by polishing the surface with a file from a file, paper, emery powder, steel wool, rubber whetstone, felt buff, or the like.

When the surface roughness of the cavity surface 10A is made different depending on the region, it is preferable to appropriately select a polishing method and a polishing degree in finishing. For example, after all areas are polished with slightly coarse paper, a specific area is polished again with fine paper, so that two areas having different surface roughness can be formed on the cavity surface 10A.

Further, as shown in FIG. 17, a nest 10f having a carefully polished mold surface is assembled into a mold 10d having a rough mold surface to finish the two, so that two different surface roughnesses are obtained. Area is cavity surface 10A
Can be formed. Thus, for example, an area of the cavity surface 10A that has been polished again with fine-grained paper, or a nest 1 having a carefully polished mold surface
0f is a central area A of the antireflection molded article 8, that is, a visible area in a part to be a transparent window, and can be used to make the average surface roughness Ra 2.0 to 35 nm.
Further, the area of the cavity surface 10A, which is merely polished with slightly coarse paper, or the mold 10d having the rough mold surface is the periphery of the central area A and the periphery of the liquid crystal display unit. In other words, it can be used to set the average surface roughness Ra to about 35 to 85 nm in the area B, in other words, in the surrounding area around the viewing area in the part to be the transparent window.

In the above-mentioned molding transfer method, first, a transfer material 9A as a decorative sheet 9 is fed into a molding die 10. At this time, the sheet transfer material 9A may be fed one by one, or a necessary portion of the long transfer material 9A may be sent intermittently. When the long transfer material 9A is used, it is preferable to use a feeder having a positioning mechanism so that the register of the symbol layer 120 of the transfer material 9A and the molding die 10 coincide. Also, when the transfer material 9A is intermittently fed,
After the position of the transfer material 9A is detected by the sensor, the transfer material 9A is detected.
Is fixed by the movable mold and the fixed mold, the transfer material 9A can be always fixed at the same position, and the design layer 120 is fixed.
This is convenient because no positional deviation occurs.

After the molding die 10 is closed, the molten resin 1A is injected and filled into the die 10 from the gate, and the transfer material 9A is adhered to the surface of the transferred material at the same time as the transfer object is formed.

The resin that can be used for the transparent substrate 1 includes polystyrene resin, polyolefin resin, A
General-purpose resins such as BS resin, AS resin, and AN resin can be used. In addition, general-purpose engineering resins such as polyphenylene oxide / polystyrene resin, polycarbonate resin, polyacetal resin, acrylic resin, polycarbonate-modified polyphenylene ether resin, polybutylene terephthalate resin, ultra-high molecular weight polyethylene resin, polysulfone resin, polyphenylene sulfide resin A super engineering resin such as a resin, a polyphenylene oxide resin, a polyarylate resin, a polyetherimide resin, a polyimide resin, a liquid crystal polyester resin, and a polyallyl heat-resistant resin can also be used.

The shape of the transparent substrate 1 can be any shape as long as it is a curved surface or a flat surface that is convex to the surface side having a radius of curvature of 40 mm or more in the transparent window portion. It may have a three-dimensional or three-dimensional curved surface.

After cooling the resin molded article as the transfer object,
The molding die 10 is opened and the resin molded product is taken out. Finally, the base sheet 7 of the transfer material 9A is peeled off (see FIG. 7). In this way, only the transfer layer can be transferred to the molded article (see FIG. 8).

Next, an insert method using the insert material 9 will be described.

To obtain the insert 9, the following method may be used.

The insert material 9 is such that the hard coat layer 4 and the design layer 120 are provided on the base sheet 7 (see FIG. 2).

The base sheet 7 may be the same as the transfer sheet 9A. Further, the hard coat layer 4, the design layer 120, the adhesive layer 2, and the like can be formed in the same manner as in the case of the transfer material 9A.

In the case of the insert method, the base sheet 7
Is not removed, the hard coat layer 4 is formed on one surface of the base sheet 7 and the design layer 120 and the adhesive layer 2 are formed on the other surface, or the hard coat layer 4 and the design layer 120 are formed on one surface. And the adhesive layer 2 can be formed on the other surface.

Further, instead of forming all the layers to be formed on the transparent substrate 1 by the insert method, only the layers which are preferably formed by the insert method are formed by the simultaneous molding and decorating method. Preferably, the layer is formed separately.

Next, a method of using the insert 9 will be described.

The molding die 10 has a radius of curvature of 40 m on the cavity surface 10A at a location corresponding to the transparent window.
A material having a curved surface or a flat surface of m or more is used. In the case of the insert material 9, since fine irregularities cannot be formed by the release layer 3, fine irregularities may be formed on the cavity surface 10 </ b> A corresponding to the transparent window of the mold 10 (see FIGS. 3A and 11). ). In particular, the average surface roughness Ra of the cavity surface 10A at a location corresponding to the transparent window is 2.0 to 1
It is preferable that the average surface roughness Ra at the interface between the antireflection layer 5 and the transparent window portion to be formed later be 2.0 to 150 nm.

First, the insert material 9 as the decorative sheet 9 is fed into the molding die 10 (see FIG. 3). that time,
It is preferable to feed the single sheet transfer material 9A one by one. When the molding shape is a three-dimensional shape, the insert material 9 may be heated and softened by a heat source, and may be closely attached to the cavity surface 10A by vacuum suction. Next, the mold is clamped, and the molten resin 1A is injected from the gate (see FIG. 4). When the mold is opened, a molded product in which the insert material 9 and the molding resin 1A are integrated can be obtained (see FIG. 5).

In this way, the insert material 9 and the molding resin are integrated, and the transparent window has an average surface roughness Ra2.
It is possible to form a molded product having a curved surface or a flat surface with a radius of curvature of 40 mm or more in which the transparent window portion has a shape protruding toward the surface side and has a shape of 0 to 150 nm.

After forming the hard coat layer 4 using the decorative sheet 9 such as the transfer material 9A or the insert material 9, the antireflection layer 5 is formed at least on the transparent window portion (FIG. 1A,
(See FIG. 1B). By providing the antireflection layer 5, reflection of the transparent substrate 1 can be prevented.

The material of the antireflection layer 5 is Al
Deposition layer of a metal compound such as ₂ O ₃ , ZnO ₂ , and MgF _2, or vapor deposition in which a metal compound having a low refractive index such as SiO ₂ and MgF ₂ and a metal compound having a high refractive index such as ZnO ₂ and TiO ₂ are laminated. And a resin coating layer made of a fluorine-based polymer, silicon oxide gel, or the like. Further, a combination of these may be used.

The method for producing the antireflection layer 5 includes a vacuum deposition method, a sputtering method, an ion plating method and the like. Alternatively, an organic metal compound such as a metal alcoholate or a metal chelate is applied onto the transparent substrate 1 by an immersion method, a printing method, a coating method, or the like, and then a metal oxide film is formed by light irradiation or drying to form an anti-reflection layer. There is also a method to obtain 5.

The antireflection layer 5 may be a single low refractive index layer or a plurality of low antireflection layers described later (see FIG. 23).
It may be a composite layer of a low refractive index layer and a high refractive index layer. The use of a composite layer can further improve the antireflection property. In order to avoid an increase in the number of steps when a composite layer is used, it is very efficient to form the antireflection layer 5 by a continuous coating method using roll-to-roll. In the transfer material 9A as in the present case, continuous production by roll-to-roll is possible. Here, the low refractive index and the high refractive index refer to a result of comparison with the refractive index of a layer located below these layers. For example, when the antireflection layer 5 has a single-layer configuration, the refractive index of the hard coat layer 1 is a comparison target. When the anti-reflection layer 5 is a composite layer, the refractive indexes of the layers located immediately below the layers constituting the anti-reflection layer 5 are compared.

The film thickness of the antireflection layer 5 is represented by the general formula n × d = λ.
/ 4 or the general formula n × d = 3λ / 4 (where n is the refractive index of the low-refractive-index substance, d is the thickness of the low-refractive-index substance, and λ is the low-reflection center wavelength, respectively). Good to choose. Usually, the thickness of the antireflection layer 5 is 0.01 to 2
It is in the range of μm.

Further, if necessary, an antifouling layer 190 may be provided on the antireflection layer 5 (see dashed lines in FIGS. 1A, 1B and 1C). The antifouling layer 190 is a layer provided on the antireflection layer 5 in order to prevent the antireflection molded article 8 from being contaminated, and is a layer made of a material having water repellency and oil repellency. As the antifouling layer 190, a surfactant having fluorine in a terminal group may be used. In order to provide the antifouling layer 190, a coating method, a dipping method, a vacuum deposition method, or the like may be used. The thickness of the antifouling layer 190 is preferably as thin as possible. If the thickness of the antifouling layer 190 is large, the antireflection molded product 8
This is because the light transmittance becomes low.

[0084]

EXAMPLES (Examples 1 to 9) A 50 μm thick polycarbonate film was used as a base sheet, and a 4 μm thick hard coat layer was formed thereon using a urethane acrylate resin to obtain an insert material (see FIG. 2). ).

Next, various injection molding dies having an average surface roughness Ra of 0.002 to 0.19 μm corresponding to the transparent window portion were prepared, and an insert material was placed on each of the dies. The mold was closed, and an acrylic resin was injected to obtain a molded article having various degrees of irregularities formed on the surface of the hard coat layer.

The shape of each molded product is 60 mm × 60 mm ×
It was a 1.5 mm flat plate.

Next, on the hard coat layer of each molded product,
An anti-reflection layer made of magnesium fluoride having a thickness of about 0.1 μm was formed to obtain an anti-reflection molded product (see FIG. 11).

When the reflectance of each of the anti-reflection molded products thus obtained was measured, Examples 1 to 6 had high anti-reflection properties, and Examples 1 to 5 were particularly excellent. Although Examples 7 and 8 have an antireflection effect, Examples 1 to 6
It was considerably inferior to. Example 9 had little antireflection effect.

[0089]

[Table 1]

In the evaluation results, ◎ indicates extremely good, ○ indicates good, Δ indicates acceptable, and × indicates unacceptable.

(Examples 10 to 18) A 38 μm-thick polyester film was used as a base sheet, and a base material 10
A release layer having an average surface roughness Ra of 0.002 to 0.19 μm is formed using a melamine-based resin obtained by adding 8 parts by weight of silica beads having a particle size of 0.4 to 8 μm to 0 parts, and urethane is formed thereon. A hard coat layer having a thickness of 4 μm was formed using an acrylate resin, and an adhesive layer was formed thereon using an acrylic resin to obtain various transfer materials (see FIG. 2).

60 mm × 60 m made of acrylic resin
Each transfer material is placed on a m × 1.5 mm plate-shaped molded product, and after pressing with a heating roll from the back, the base sheet is peeled off, and a hard coat layer with various irregularities is laminated on the surface. A molded article was obtained.

Next, on the hard coat layer of each molded product,
An anti-reflection layer made of magnesium fluoride having a thickness of about 0.1 μm was formed to obtain various anti-reflection molded products.

When the reflectance of each of the antireflection molded products thus obtained was measured, Examples 10 to 15 had high antireflection properties, and Examples 10 to 14 were particularly excellent. Examples 16 to 17 have an antireflection effect,
It was considerably inferior to Examples 10 to 15.
Example 18 had almost no antireflection effect.

[0095]

[Table 2]

(Examples 19 to 27) Using the insert material used in Example 1, it was placed on an injection mold (see FIG. 10), the mold was closed, and an acrylic resin was injected.
A molded product having a flat plate shape of 60 mm × 60 mm × 1.5 mm and a semicircular shape having a radius of curvature of 30 to 300 mm was produced (see FIG. 12). The cavity surface of the injection mold was set such that the average surface roughness Ra of these molded products was all about 0.01 μm.

Then, an antireflection layer made of magnesium fluoride having a thickness of about 0.1 μm was formed on the hard coat layer of these molded products to obtain an antireflection molded product.

[0098]

[Table 3]

As a result of measuring the reflectance of each of the anti-reflection molded products obtained as described above, Examples 19 to 24 had high anti-reflection properties, and Examples 19 to 23 were particularly excellent. Although Examples 25 and 26 have an antireflection effect, they were considerably inferior to Examples 19 to 24. Example 27 had almost no antireflection effect.

[0100]

Since the present invention employs the above-described configuration, the following effects can be obtained.

The method for producing the antireflection molded article of the present invention comprises:
A decorative sheet having at least a hard coat layer formed on a base sheet is placed so that the base sheet side is in contact with a cavity surface of a mold having a curved surface with a radius of curvature of 40 mm or more or a flat surface at a portion corresponding to a transparent window. Injecting a transparent molten resin into a mold to obtain an integrated product of a decorative sheet and a transparent substrate made of a resin, and then peeling the base sheet from the integrated product to obtain a transparent window at an average surface roughness Sa Ra
Is 2.0 to 150 nm, and a curved or flat surface that is convex on the surface side having a radius of curvature of 40 mm or more in the transparent window portion, and then forms an antireflection layer on the surface side of the transparent base material. An antireflection molded product having an improved antireflection effect and hard coat properties can be easily obtained.

The antireflection molded product mold according to the present invention has a radius of curvature of 40 mm at a portion corresponding to the transparent window.
Since the surface is a curved surface or a flat surface as described above, an antireflection molded product having an excellent antireflection effect and a hard coat property can be easily obtained by using the curved surface or the flat surface.

Further, the antireflection molded article of the present invention has at least an antireflection layer formed on the surface of a transparent substrate, and has an average surface roughness Ra of an interface of a transparent window portion on which the antireflection layer is formed.
Is 2.0 to 150 nm, and the surface of the transparent window has a curved surface or a flat surface with a radius of curvature of 40 mm or more. Therefore, an antireflection molded product having an excellent antireflection effect and a hard coat property. is there.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an antireflection molded product according to the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of a decorative sheet used in the method for manufacturing an antireflection molded product according to the present invention.

FIG. 3 is a cross-sectional view showing one step of the method for manufacturing an antireflection molded product according to the present invention.

FIG. 4 is a cross-sectional view showing one step of the method for manufacturing an antireflection molded product according to the present invention.

FIG. 5 is a cross-sectional view showing one step of the method for manufacturing an antireflection molded product according to the present invention.

FIG. 6 is a cross-sectional view showing one embodiment of a decorative sheet used in the method for manufacturing an antireflection molded product according to the present invention.

FIG. 7 is a cross-sectional view showing one step of the method for manufacturing an antireflection molded product according to the present invention.

FIG. 8 is a cross-sectional view showing one step of the method for producing an antireflection molded product according to the present invention.

FIG. 9 is a graph for obtaining an average surface roughness Ra in the present invention.

FIG. 10 is a cross-sectional view showing one embodiment of a mold for an antireflection molded product according to the present invention.

FIG. 11 is a sectional view showing an embodiment of the antireflection molded product of the present invention.

FIG. 12 is a sectional view showing an embodiment of the antireflection molded product of the present invention.

FIG. 13 is a schematic cross-sectional view showing how the antireflection effect changes when the average surface roughness Ra differs.

FIG. 14 is a table showing the relationship between the use of the antireflection molded article of the present invention, the reflectance, and the average surface roughness Ra.

FIG. 15 is a perspective view showing one embodiment of the antireflection molded product of the present invention.

FIG. 16 is a sectional view showing an embodiment of the antireflection molded product of the present invention.

FIG. 17 is a cross-sectional view showing one embodiment of a molding die used in the method for producing an antireflection molded product of the present invention.

[Description of Signs] 1 Transparent substrate 2 Adhesive layer 3 Release layer 4 Hard coat layer 5 Antireflection layer 7 Base sheet 8 Antireflection molded product 9 Decorative sheet 10 Mold 11 Pattern layer 12 Antifouling layer 13 Molten resin

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2K009 AA04 AA15 BB11 BB14 BB15 BB24 CC03 CC06 CC09 CC24 CC26 CC35 CC42 DD02 DD03 DD05 DD06 EE05 4F202 AD09 AD20 AF01 AF07 AG03 AG21 AR13 CA11 CB01 CB13 CB19 CD22 CK01 AF01 AF07 AG03 AG21 AR13 JA07 JB13 JB19 JF05 JW21 JW50

Claims (11)

[Claims] 1. A decorative sheet having at least a hard coat layer formed on a base sheet is placed on a cavity surface of a mold having a curved surface with a radius of curvature of 40 mm or more or a flat surface at a position corresponding to a transparent window. Placed in contact with each other, injecting a transparent molten resin into the mold to obtain an integrated product of the decorative sheet and the transparent base made of resin, and then peeling the base sheet from the integrated product to form a transparent window The surface has an average surface roughness Ra of 2.0 to 150 nm, a curved surface or a flat surface which is convex on the surface side having a curvature radius of 40 mm or more in the transparent window portion, and then has an antireflection on the surface side of the transparent substrate. A method for producing an antireflection molded product, comprising forming a layer. 2. A decorative sheet having at least a hard coat layer formed on a base sheet is provided on a cavity surface of a mold having a curved surface with a radius of curvature of 40 mm or more or a flat surface at a portion corresponding to a transparent window. The transparent surface is placed so that the sides are in contact with each other, and a transparent molten resin is injected into the mold to obtain an integrated product of the decorative sheet and the transparent base material made of the resin. 0 to 150 nm, and the radius of curvature at which the shape of the transparent window is convex on the surface side is 4
A method for producing an antireflection molded product, comprising: forming a curved or flat surface of 0 mm or more, and then forming an antireflection layer on the surface side of a transparent substrate. 3. A decorative sheet comprising a base sheet having at least a hard coat layer on the entire surface, a pattern layer partially on a pattern excluding a portion to be a transparent window, and an adhesive layer on the entire surface. The method for producing an antireflection molded article according to claim 1, wherein 4. The method according to claim 1, wherein an antifouling layer is formed on the antireflection layer. 5. A hard coat layer is disposed at least on a surface of a transparent base material, and a surface to be a transparent window has an average surface roughness Ra.
Is from 2.0 to 150 nm, and the radius of curvature in the transparent window portion is 40 mm or more. A mold for an antireflection molded product, having a cavity surface that is a curved surface or a flat surface having a radius of 40 mm or more. 6. The average surface roughness Ra of a cavity surface at a position corresponding to a transparent window is 2.0 to 170 nm.
The anti-reflection molded product mold described in the above. 7. An anti-reflection layer is formed at least on the surface of a transparent substrate, and the average surface roughness Ra at the interface of the transparent window portion where the anti-reflection layer is formed is 2.0 to 150 nm. An anti-reflection molded product having a curved surface or a flat surface having a radius of curvature of 40 mm or more and convex on the surface side. 8. The anti-reflection molded article according to claim 7, wherein a pattern pattern is partially formed between the transparent base material and the anti-reflection layer except for a portion to be a transparent window. 9. The antireflection molded article according to claim 7, wherein a hard coat layer is formed between the transparent substrate and the antireflection layer. 10. The antireflection molded article according to claim 7, wherein an antifouling layer is formed on the antireflection layer. 11. An average surface roughness Ra is 2.0 to 35 nm in a visible region of a portion to be a transparent window, and is an average surface roughness in a peripheral region around a visible region of a portion to be a transparent window. The antireflection molded article according to any one of claims 7 to 10, wherein Ra is 35 to 85 nm.