JP2011002762A - Molding having light antireflection effect - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and simply provide a molding having a superior light antireflection effect, to find a surface shape and physical properties required for the molding having the superior light antireflection effect or an excellent light transmission performance and to provide the molding having specific surface shape and specific physical properties and consequently having the light antireflection effect.SOLUTION: The molding is molded by using a die having a minute shape on its surface and the minute shape on its surface is thermally transferred onto a thermoplastic resin. The molding surface has projections with average height of 100 nm to 1,000 nm or recesses with average depth of 100 nm to 1,000 nm and there are projections or recesses at an average cycle 50 to 400 nm in at least one direction.

Description

  The present invention relates to a molded article made of a specific material, having a specific surface shape, and having an excellent antireflection effect on light and an excellent light transmission performance.

  There are many objects for which reflection is desired to be prevented. For example, Patent Document 1 describes an example of a meter front cover that is provided on the front face of various meters and prevents reflection. In addition, it is extremely important to lower the reflectance for a molded body that wants to increase the transmittance as much as possible, such as a molded body such as a lens. Furthermore, in flat panel displays (hereinafter abbreviated as “FPD”) such as liquid crystal display (LCD) and plasma display (PDP), molding is performed to prevent light reflection on the surface of the display in order to ensure visibility Providing a body is extremely important.

  As means for preventing such reflection, the following antireflection means have been mainly used. (1) What is generally referred to as a dry method, that is, a dielectric multilayer film produced by a vapor phase process to achieve a low reflectivity by optical interference effect, (2) Generally referred to as a wet method In other words, a low refractive index material coated on a substrate film has been used. Further, it is known that (3) a low reflectance can be expressed by imparting a fine structure to the surface as a technology completely different from these (Patent Documents 1 to 12).

  Among them, the above (3) is mentioned because of its high antireflection performance, but as a method for further improving the performance of the antireflection effect of light while taking the means for imparting the fine structure of (3) to the surface. Various studies have been made. For example, a method is known in which an anodized film formed by anodic oxidation of an aluminum surface is combined with etching of the anodized film, and the shape is transferred to an antireflection film. (Patent Documents 12 to 15).

  In addition, there is also research on a material of a molded body having a fine structure on its surface. For example, Patent Document 9 and Patent Document 15 disclose a technique using a photocurable composition or a thermosetting composition as such a material. Has been.

  However, none of these still have sufficient performance, and in particular, not only the light antireflection performance but also the light transmission performance is not sufficient, and further improvement has been demanded.

JP 2007-264594 A Japanese Patent Laid-Open No. 50-070040 JP-A-9-193332 Japanese Patent Laid-Open No. 2003-162205 JP 2003-215314 A JP 2003-240903 A JP 2004-004515 A JP 2004-059820 A JP 2004-059822 A Japanese Patent Laying-Open No. 2005-010231 Japanese Patent Laid-Open No. 2005-092099 JP 2003-043203 A JP 2005-156695 A JP 2007-086283 A JP 2006-091859 A

  The present invention has been made in view of the above-described background art, and a problem thereof is to efficiently and easily provide a molded product excellent in light reflection prevention effect, light transmission performance, and the like. Furthermore, the surface shape and physical properties required for a molded product having an antireflection effect of light and an antireflection effect of light having excellent light transmission performance are found, and reflection of light having such a specific surface shape and physical properties is found. It is in providing the molded article which has a prevention effect.

  As a result of intensive studies to solve the above problems, the present inventor has processed and molded the surface microstructure at the same time in a processing step using a thermoplastic resin, thereby preventing light reflection and light transmission performance. The present inventors have found that a molded product that is extremely excellent in the above can be obtained efficiently and simply, and have reached the present invention.

  Furthermore, with regard to the mold used at that time, when an anodic oxide coating of aluminum is used as the mold, the surface is not uniform due to the processing stress generated when rolling the aluminum material, the processing itself, and the environment in the manufacturing process. It has been found that, for example, surface non-uniformity caused by dust and contaminants mixed during processing adversely affects the light reflection preventing effect and light transmission performance of the obtained molded product. That is, it has been found that a molded product obtained by transferring a mold obtained from such an aluminum material brings about a light antireflection effect and a decrease in transmission performance. In order to solve this problem, it is possible to obtain a molded product with the desired performance, in particular, the antireflection effect of light, the light transmission performance, etc. by finishing the surface of the aluminum material in advance. And reached the present invention.

  That is, the present invention is a molded product obtained by using a mold having a fine shape on the surface and thermally transferring and molding the fine shape of the mold on the surface of the thermoplastic resin, and has an average height of 100 nm to 1000 nm on the surface. A molded product having the following convex portions or concave portions having an average depth of 100 nm to 1000 nm, and the convex portions or concave portions are present at an average period of 50 nm to 400 nm in at least one direction. Is to provide.

  The present invention is not necessarily limited to a membrane. Because it has a fine shape directly on the surface of the molded product, it does not require a manufacturing process such as sticking to the base material, and provides a molded product that is extremely excellent in light reflection prevention effect, light transmission performance, etc. efficiently and simply can do.

It is a scanning electron micrograph (30,000 times) which shows an example of the type | mold for manufacturing the molded article of this invention. It is a scanning electron micrograph (40,000 times) which shows the cross section of an example of the molded article of this invention. It is the spectrum of the reflectance after the visibility correction | amendment of the molded article of this invention.

[About type]
<1. Mold Making Method>
The molded product excellent in the light reflection preventing effect, light transmission performance, etc. of the present invention is obtained by using a mold having a fine shape on the surface and thermally transferring the fine shape on the surface to the thermoplastic resin and molding the mold. Obtained by. There are no particular limitations on the type of mold having a fine shape on the surface or the method of producing the mold, but a die using an anodized film on the surface of an aluminum material; a fine shape mechanically with a diamond cutting tool using a fine cutting machine, etc. A mold formed by electroforming using a metal plating suitable for plating such as nickel, chromium, copper, and gold; and the like.

  Among these, the method of anodizing the surface of an aluminum material and transferring it using a fine tapered hole on the surface of the anodized film is preferable because it is easy to form a fine shape as a mold. .

<2. Type using anodized film on the surface of aluminum material>
Here, the “aluminum material” may be a material whose main component is aluminum, and may be pure aluminum (1000 series) or an aluminum alloy. The pure aluminum in the present invention is aluminum having a purity of 99.00% or more, preferably a purity of 99.50% or more, and more preferably a purity of 99.85% or more. The aluminum alloy is not particularly limited, and examples thereof include an Al—Mn alloy (3000 series), an Al—Mg alloy (5000 series), and an Al—Mg—Si alloy (6000 series). Among these, pure aluminum (1000 series); aluminum alloy 5005; in terms of excellent workability and corrosion resistance due to a relatively small amount of Mg added, and good “tapered pores”. An improved alloy of aluminum alloy 5005 (for example, 58D5 made by Nippon Light Metal) or the like is preferable.

  The type of aluminum material is not particularly limited, but using an aluminum plate, an extruded tube, a drawn tube, or the like that has been industrially rolled is used in the present invention to polish the aluminum material, which will be described later. This is preferable for simplifying the process.

  Further, the mold having a fine shape on the surface in the present invention is a mold in which a fine shape is formed on the surface of an aluminum material by a combination of the formation of an anodized film by anodization and the etching of the anodized film. It is preferable that a molded product having excellent light reflection preventing effect and light transmission performance can be obtained. Particularly preferably, a mold having a fine shape on the surface is a combination of the formation of an anodized film by anodization on the surface of the aluminum material after the surface of the aluminum material is polished and the etching of the anodized film And, more preferably, after processing by mechanical polishing, chemical polishing and / or electrolytic polishing, forming an anodized film on the surface of the aluminum material by anodic oxidation, and It is a mold in which a fine shape is formed in combination with etching of an anodized film.

<2-1. Anodization>
"Anodic oxidation" is a method in which an electric current is passed in an acid solution using an aluminum material as an anode, and oxygen and aluminum generated by electrolysis of water react to form an aluminum oxide film having pores on the surface. It is.

  The electrolytic solution is not particularly limited as long as it is an acid solution. For example, any of sulfuric acid-based, oxalic acid-based, phosphoric acid-based, or chromic acid-based electrolyte solution may be used. An oxalic acid-based electrolyte is preferable in that the pore size can be obtained.

  The conditions for anodizing are not particularly limited as long as the above-described target shape can be obtained, but the conditions for using oxalic acid as the electrolytic solution are as follows. That is, the concentration is preferably 0.01 to 0.5M, more preferably 0.02 to 0.3M, and particularly preferably 0.03 to 0.1M. The applied voltage is preferably 20 to 120V, more preferably 40 to 110V, particularly preferably 60 to 105V, and still more preferably 80 to 100V. The liquid temperature is preferably 0 to 50 ° C, more preferably 1 to 30 ° C, and particularly preferably 2 to 10 ° C. The treatment time for one time is preferably 5 to 500 seconds, more preferably 10 to 250 seconds, particularly preferably 15 to 200 seconds, and further preferably 20 to 100 seconds. Anodizing under such conditions is preferable in that a “mold having a fine shape” can be produced by combining with the etching conditions described below. For other acids, the same anodic oxidation conditions as described above are preferable.

  When the voltage is too large, the average interval between the formed pores becomes too large, and the mold is thermally transferred to the thermoplastic resin, thereby forming the projections or depressions formed on the surface of the obtained molded product. The average period of may become too large. On the other hand, when the voltage is too small, the average interval between the pores becomes too small, and by transferring the mold to the thermoplastic resin, the convex or concave portions formed on the surface of the obtained molded product The average period may become too small. In the molded product of the present invention, it is essential that convex portions or concave portions existing on the surface thereof exist at an average period of 50 nm or more and 400 nm or less in at least one direction, so that the voltage is adjusted to fall within this range. Preferably it is done.

  If the treatment time is too long, the height of the concavo-convex part of the molded product may be too high, and if it is too short, the height of the concavo-convex part of the molded product becomes too low, and the expected antireflection effect decreases. There is a case. Moreover, it is preferable to repeat anodization and the etching mentioned later alternately.

<2-2. Etching>
Etching is mainly performed in order to obtain a mold having a desired shape and an enlarged pore diameter of the anodic oxide coating. By combining the anodization and etching described above, the pore diameter of the pores forming the tapered shape formed on the anodized film on the surface of the aluminum material, the height and depth of the irregularities of the taper shape Etc. can be adjusted.

  The etching method can be used without particular limitation as long as it is a generally known method. For example, as the etching solution, an acid solution such as phosphoric acid, nitric acid, acetic acid, sulfuric acid, chromic acid, or a mixture thereof can be used. Phosphoric acid or nitric acid is preferable, and phosphoric acid is particularly preferable in that a necessary dissolution rate can be obtained and a more uniform surface can be obtained.

  The concentration, immersion time, temperature, and the like of the etching solution may be appropriately adjusted so that a desired fine shape can be obtained. The conditions for phosphoric acid are as follows. That is, the concentration of the etching solution is preferably 1 to 20% by mass, more preferably 1.2 to 10% by mass, and particularly preferably 1.5 to 2.5% by mass. The liquid temperature is preferably 30 to 90 ° C, more preferably 35 to 80 ° C, and particularly preferably 40 to 60 ° C. 1 treatment time (immersion time) is preferably 1 to 60 minutes, more preferably 2 to 40 minutes, particularly preferably 3 to 20 minutes, and further preferably 5 to 10 minutes. Etching under such conditions is preferable in that a “mold having a fine shape” can be produced in combination with the above-described anodizing conditions. Note that the same conditions as described above are preferable for other acids.

  The above-mentioned anodization and etching can be combined to obtain a “mold formed with a fine shape”. “Combination” refers to repeating anodization by anodizing first. It is also preferable to wash with water between each treatment. The number of anodic oxidation and etching may be appropriately adjusted so as to obtain a desired shape, but the number of combinations is preferably 1 to 10 times, more preferably 2 to 8 times, and particularly preferably 3 to 6 times.

  In the molded product of the present invention, when obtaining a “mold formed with a fine shape” to be thermally transferred, a particularly preferred combination is anodization with an aqueous oxalic acid solution and etching with an aqueous phosphoric acid solution. The overall preferred conditions are a combination of each of the preferred conditions described above.

<2-3. Polishing>
A mold in which the surface of an aluminum material is processed by polishing and then a fine shape is formed on the surface of the aluminum material by the above-described method, and the fine shape is thermally transferred to a thermoplastic resin. This is preferable because an excellent antireflection film can be provided. As polishing, mechanical polishing, chemical polishing and / or electrolytic polishing are preferable. That is, after processing by mechanical polishing, chemical polishing and / or electrolytic polishing, a fine shape is formed on the surface of the aluminum material by a combination of formation of an anodized film by anodization and etching of the anodized film. Is particularly preferable as the mold.

  When the surface of the aluminum material is processed by mechanical polishing, chemical polishing and / or electrolytic polishing, any one of mechanical polishing, chemical polishing and electrolytic polishing may be used, or any combination thereof may be used. By polishing the surface of the aluminum material, the surface of the aluminum material becomes uniform, and the molded product of the present invention obtained by using the surface obtained by processing it as a mold significantly improves the light transmission performance. To do.

  The surface Ra and Ry of the aluminum material obtained by polishing are not particularly limited, but the surface Ra of the aluminum material obtained by polishing is preferably 0.1 μm or less, more preferably 0.03 μm or less, particularly Preferably it is 0.02 micrometer or less. Ry is preferably 1 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.35 μm or less. Here, Ra and Ry are values obtained according to JIS B0601 (1994), Ra is “arithmetic mean roughness”, and Ry is “maximum height”.

  The effect of the present invention is easily achieved when Ra and / or Ry is used. In particular, when the molded article of the present invention is a film, an antireflection film having a haze of 15% or less can be obtained only by this polishing. Further, this polishing makes it possible to reduce the reflectance after the visibility correction to 0.5% or less in all wavelength regions of 380 nm to 780 nm.

  From the point of further improving the light transmission performance of the obtained molded product, electrolytic polishing alone, mechanical polishing alone, a combination of electrolytic polishing and chemical polishing, a combination of mechanical polishing and chemical polishing, a combination of electrolytic polishing and mechanical polishing, A combination of electrolytic polishing, mechanical polishing, and chemical polishing is preferable, and among them, electrolytic polishing alone or a combination including electrolytic polishing is more preferable. Among them, the method of performing electropolishing after mechanical polishing is particularly preferable because of its large effect and easy processing. Hereinafter, each polishing method will be described in detail.

<2-3-1. Mechanical polishing>
The mechanical polishing is not particularly limited and may be performed according to a conventional method. Specifically, for example, a buff polishing method, a grinder buff polishing method, a leuter polishing method, a belt sander polishing method, a brush polishing method, a steel wool polishing method, Examples thereof include a sand blast polishing method, a liquid honing polishing method, a molding polishing method, a lathe polishing method, a barrel polishing method, and a lapping polishing method, and these may be used alone or in any combination. Among these, the buff polishing method, lathe polishing method, wrapping are effective in that the surface of the aluminum material for the application can be efficiently processed, the polished surface is excellent, and the light transmission performance of the resulting molded product is improved. A polishing method and a buff polishing method are preferable, and a buff polishing method such as a single-sided flat buff, a ball buff, and a bias buff; a precision lathe polishing method is particularly preferable.

  There is no restriction | limiting in particular in the abrasive used, What is necessary is just to use the abrasive normally used. Specifically, for example, diamond, cubic boron nitride, silicon carbide, corundum, cerium oxide, and the like may be appropriately selected according to the polishing method used and the target shape. By these optimizations, it is possible to improve the light transmission performance of the obtained molded product. Buffing method using corundum (alumina), which has good compatibility with aluminum materials, as a polishing material, ball buff using colloidal silica as polishing material, silicic anhydride A precision lathe polishing method using a bias buff used as an abrasive or a diamond tool is preferred.

  In lapping, a grinding fluid is used as necessary, but a commonly known water-soluble or oil-soluble grinding fluid may be used. A water-soluble grinding liquid is preferable in that scratches such as scratches are difficult to enter, permeability as a coolant liquid is good, processing resistance is low, influence on the aluminum surface can be reduced, and cleaning is simple.

  After the mechanical polishing, scrub cleaning is preferably performed to remove the polishing material adhering to the surface of the aluminum material. There is no particular limitation as long as the method does not damage the surface of the aluminum material. Specific examples of the apparatus used in the cleaning process include an ultrasonic cleaner, a brush scrub cleaner, a pure water spin cleaning dryer, an RCA cleaner, and a functional water cleaner.

<2-3-2. Chemical polishing>
The chemical polishing in the present invention is a method of polishing the surface of an aluminum material by causing a chemical reaction by causing a polishing liquid to act, and is not particularly limited, and may be performed according to a conventional method. Specifically, for example, phosphoric acid-nitric acid method, Kaiser method, Alupol I, IV, V method, General Motor method, phosphoric acid-acetic acid-copper salt method, phosphoric acid-nitric acid-acetic acid method, Alcoa R5 method, etc. Can be mentioned. By appropriately selecting the polishing liquid, temperature, time, and the like according to the chemical polishing method to be used, it is possible to improve the light transmission performance of the obtained molded product. Among these, the phosphoric acid-nitric acid method and the phosphoric acid-acetic acid-copper salt method are preferable in terms of bath management, results, and polished surface finish.

  A preferable treatment temperature in the phosphoric acid-nitric acid method is 70 ° C. to 120 ° C., more preferably 80 ° C. to 100 ° C., and a preferable polishing time is 30 seconds to 20 minutes, and further preferably 1 minute to 15 minutes. The composition of the polishing liquid used is a mixture of 40 to 80% by volume phosphoric acid, 2 to 10% by volume nitric acid, and remaining water.

<2-3-3. Electrolytic polishing>
The electrolytic polishing in the present invention is for polishing the surface of aluminum by electrolysis in an electrolytic solution, and is not particularly limited and can be performed according to a conventional method. The surface is polished by passing a direct current with aluminum as an anode in a solution in which the aluminum material is difficult to dissolve due to low water content such as an acidic solution. Specific examples include a Kaiser method, a phosphoric acid method, an Erftwerk method, and an Aluflex method. The polished surface differs depending on the electrolytic solution used, current value, treatment temperature, time, and the like, and the light transmission performance of the obtained molded product can be improved by appropriately selecting these.

Among these, the phosphoric acid method and the phosphoric acid-sulfuric acid method are general, and are preferable in terms of bath management, finishing, and obtained surface characteristics. The electrolysis conditions preferred phosphoric acid method, the temperature is usually 40 ° C. to 90 ° C., preferably from 50 ° C. to 80 ° C., the current density is preferably ^{20~80A / dm 2, 30~60A / dm} 2 Gayori preferable. Moreover, as an electrolyte solution to be used, 85-100 volume% phosphoric acid is preferable. Moreover, in order to remove an oxide film after an electrolytic polishing process, you may immerse in a nitric acid bath.

<2-4. Degreasing treatment>
It is also preferable to perform a degreasing treatment as necessary before the mechanical polishing, chemical polishing and / or electrolytic polishing described above. Examples of the degreasing method include an organic solvent method, a surfactant method, a sulfuric acid method, an electrolytic degreasing method, an alkaline degreasing method, an emulsifying degreasing method, and a phosphate method. It is preferable to perform non-erodible degreasing treatment from the viewpoint of not roughening the surface of the aluminum material more than necessary.

<3. Die with mechanically formed fine shape using a fine cutting machine>
As a method for mechanically forming a fine shape, for example, a mold is formed in a controlled temperature-controlled room using a high-precision fine cutting machine and a diamond bit with extremely small surface arithmetic average roughness (Ra). A method of processing a concavo-convex shape, a concave shape, or a convex shape is preferable for the mold substrate.

  By using a high-precision fine cutting machine, three-dimensional processing on the mold substrate surface can be performed with high accuracy. The precision of the X, Y, and Z movement axes of the fine cutting machine is preferably 10 nm or less, and particularly preferably 1 nm or less. The diamond tool used for processing the concavo-convex shape, the concave shape or the convex shape on the mold substrate may be a single crystal diamond tool or a sintered diamond tool, but a single crystal diamond tool is preferable.

[About molded products]
“Membrane” is also included in the molded product of the present invention, but in order to take advantage of the advantage that the molded product of the present invention is produced by thermal transfer and molding to a thermoplastic resin, it is thicker than a film. Is preferred. Here, the “film” means a film having a thickness of 0.1 mm or less. Rather than sticking an antireflection film, it is preferable to transfer the fine shape directly to the surface of the molded product from the viewpoint that the number of steps is reduced and the antireflection effect is surely obtained.

<1. Surface fine shape of molded product>
In addition, the molded product of the present invention has, on its surface, a convex portion having an average height of 100 nm to 1000 nm or a concave portion having an average depth of 100 nm to 1000 nm, and the convex portion or the concave portion is at least in one direction. On the other hand, it must be present with an average period of 50 nm to 400 nm. Here, the convex portion refers to a portion protruding from the reference surface, and the concave portion refers to a portion recessed from the reference surface. The molded product of the present invention may have a convex portion or a concave portion on the surface thereof. Moreover, you may have both a convex part and a recessed part, Furthermore, you may have the structure where they connected and waved.

  When the molded product of the present invention has both sides, such a convex part or concave part may be provided on both sides, but it is essential that it is provided on at least one surface. Especially, it is preferable to have on the outermost surface in contact with air. Air has a refractive index significantly different from that of the molded product of the present invention, and the interface of substances having different refractive indexes has the specific structure of the present invention, so that antireflection performance and transmission improvement performance are exhibited well. This is because that.

  It is preferable that the convex portions or the concave portions are present uniformly over the entire surface of the molded product in order to achieve the above effects. In the case of the convex portion, it is essential that the average height from the reference surface is 100 nm or more and 1000 nm or less. Also in the case of the concave portion, it is essential that the average depth from the reference surface is 100 nm or more and 1000 nm or less. The height or depth may not be constant, and the average value may be within the above range, but it is preferable that the height or depth has a substantially constant height or a constant depth.

  Whether it is a convex portion or a concave portion, the average height or average depth is preferably 150 nm or more, and particularly preferably 200 nm or more. Moreover, it is preferable that it is 600 nm or less, and it is especially preferable that it is 500 nm or less. If the average height or the average depth is too small, good optical characteristics may not be exhibited, and if it is too large, production may be difficult. In the case where the convex part and the concave part are connected and have a wavy structure, the average length of the highest part (above the convex part) and the deepest part (below the concave part) may be 100 nm or more and 1000 nm or less. It is preferable for the same reason.

  In the molded product of the present invention, it is essential that the convex portion or the concave portion is arranged on the surface so that the average period in at least one direction is not less than 100 nm and not more than 400 nm. The convex part or the concave part may be arranged at random or may be arranged with regularity. In any case, it is preferable in terms of antireflection properties and transmission improvement properties that the convex portions or the concave portions are disposed substantially uniformly over the entire surface of the molded product. Further, it is only necessary that the average period be at least 50 nm to 400 nm in one direction, and the average period does not have to be 50 nm to 400 nm in all directions.

  When the convex part or the concave part is arranged with regularity, it is sufficient that the average period in at least one direction is 50 nm or more and 400 nm or less as described above. Are preferably arranged such that the period in the short direction (hereinafter referred to as “x-axis direction”) is 50 nm or more and 400 nm or less. That is, it is preferable that the period is in the above range when the direction having the shortest period is taken as one direction. Further, at that time, it is particularly preferable that the period of the y-axis direction perpendicular to the x-axis direction is also set to be 50 nm or more and 400 nm or less.

  The average period (“period” when there is regularity in the location of the convex part or the concave part) is preferably 80 nm or more, and particularly preferably 150 nm or more. Moreover, 250 nm or less is preferable and 200 nm or less is especially preferable. If the average period is too short or too long, the molded product of the present invention may not be sufficiently obtained.

  The molded product of the present invention must have the above-mentioned structure on the surface, but further, it has a structure generally called “moth eye structure” to provide good antireflection performance. It is preferable at having it.

  The aspect ratio, which is a value obtained by dividing the height or depth by the average period, is not particularly limited, but is preferably 1 or more in terms of optical properties, particularly preferably 1.5 or more, and more preferably 2 or more. Moreover, 5 or less is preferable on a manufacturing process, and 3 or less is especially preferable at the point of the mechanical strength of a surface.

  The molded product of the present invention reduces the light reflectivity or improves the light transmittance by imparting the above structure to the surface, but before forming a fine shape on the mold, By performing the above-described polishing on the material to be obtained, it is possible to further improve the light reflection preventing effect and the light transmission performance. The “light” in this case is light including at least light having a wavelength in the visible light region.

<2. Physical properties of molded products>
ADVANTAGE OF THE INVENTION According to this invention, the molded article which was extremely excellent in the antireflection effect of light, the light transmission performance, etc. can be provided.

<2-1. Reflectance of molded products>
The molded product of the present invention has the shape of the uneven portion on the surface, thereby reducing the light reflectivity or improving the light transmittance. The “light” in this case is light including at least light having a wavelength in the visible light region. The molded product of the present invention must have the shape of the uneven portion, and the reflectance after the visibility correction is preferably 0.5% or less in all wavelength regions of 380 nm to 780 nm. More preferably, it is 0.4% or less, Especially preferably, it is 0.3% or less, More preferably, it is 0.1% or less. In the molded product of the present invention, the above values can be achieved.

  Here, “reflectance” refers to regular reflectance and refers to the ratio of the intensity of reflected light to the intensity of incident light. Specifically, a 5 ° regular reflectance measured using a general-purpose spectrophotometer is used. "Surface reflectance" refers to both the reflectance at the surface when light enters the molded product from the outside and the reflectance at the surface when light enters from the inside of the molded product to the outside. . That is, in any of these, those having the above reflectance are preferable.

  “Reflectance after visibility correction” refers to the reflectance after weight correction for the wavelength at which the human eye feels bright, and a normal visibility correction filter is attached to the light meter to adjust the light intensity to the human eye. It is obtained by correcting in accordance with the sensitivity (standard relative luminous sensitivity curve). Specifically, the measured spectral reflectance is obtained by numerical calculation using a color matching function and a standard illuminant by the method shown in CIE1931. In the case of a smooth surface of normal glass or transparent synthetic resin, the reflectance after the visibility correction is about 4% in the wavelength region of 380 nm to 780 nm. In the present invention, the “reflectance after visibility correction” may be simply referred to as “reflectance”.

<2-2. Molded haze>
More preferably, the molded product of the present invention has a haze of 15% or less. The haze is a percentage of the diffuse transmittance relative to the total light transmittance, and the haze in the present invention was measured using a haze meter “HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.)” according to JIS K7361. Defined as a thing. If the haze is too large, the FPD visibility may be insufficient. By polishing the surface of the aluminum material to be a mold, a molded product obtained by using it can have a haze of 15% or less, and the light transmission performance is remarkably improved. In particular, a molded product having a haze of 15% or less can be obtained only by applying the above-described polishing prior to anodic oxidation. The haze is preferably 15% or less, more preferably 12% or less, particularly preferably 8% or less, and further preferably 5% or less. In the molded product of the present invention, the above values can be achieved. In the haze measurement, the thickness of the molded product is not affected, but the above value is a value measured by forming the fine shape described above on the surface of the molded product having a thickness of 1 mm.

<3. Molded Material / Production Method>
The molded product of the present invention is produced using the mold and the molded product material. The molded product of the present invention has a very fine surface structure in which the surface has convex portions or concave portions having an average height of 100 nm or more and 1000 nm or less, and exists at an average period of 50 nm or more and 400 nm or less in at least one direction. have. Such a fine structure can accurately transfer a thermoplastic resin from a mold by thermal transfer.

<3-1. Molding material>
In general, the material to which the fine shape of the mold is transferred includes a thermosetting resin, a photocurable resin, an electron beam curable resin, a thermoplastic resin, and the like. It is essential that the material to be transferred is a thermoplastic resin. By being a thermoplastic resin, the physical properties and types of the resin can be widened, and the physical properties according to the use of the molded product can be obtained. For example, the hygroscopicity can be lowered, the dimensional stability is excellent, the molded product is not warped, the specific gravity can be adjusted, and the molded product can be reduced in weight. In addition, since the curing step is unnecessary, there is an effect that the step can be simplified and advantageous in terms of cost.

  In curable resins, the viscosity before curing is generally low, so it seems that it easily penetrates into the fine shape existing on the surface of the mold, but the molded product of the present invention is thermoplastic in that respect. Resin can be used without problems. In particular, if a preferable molding method described below or a particularly preferable molding method is used, it can be used without any problem.

<3-1-1. Thermoplastic resin>
The thermoplastic resin is not particularly limited as long as it becomes soft by heating to a glass transition temperature or higher or a melting point or higher. For example, polystyrene, acrylonitrile-styrene resin, acrylonitrile-chlorinated polyethylene-styrene resin, Styrene resins such as styrene- (meth) acrylate resins and butadiene-styrene resins; vinyl chloride resins, ethylene-vinyl chloride resins, ethylene-vinyl acetate resins, propylene resins, propylene-vinyl chloride resins, Polyolefin resins such as propylene-vinyl acetate resin, chlorinated polyethylene resin, chlorinated polypropylene resin, fluorinated polyethylene resin, and fluorinated polypropylene resin; ketone resins; polyacetal resins; polyester resins; Over preparative resin; polyamide resin; acrylate resins.

  In addition, thermoplastic resins include other polymers, organic / inorganic fine particles, colored dyes, colored pigments, extender pigments, antioxidants, ultraviolet absorbers, light stabilizers, antifoaming agents, release agents, lubricants. Further, a lubricant, a leveling agent, a flame retardant, a conductive agent, a surfactant and the like can be blended. These can be appropriately selected from conventionally known ones.

<3-2. Molded product manufacturing method>
The molded product of the present invention is formed by thermally transferring the fine shape of the mold on the surface to a thermoplastic resin. The method of thermally transferring the fine shape to the thermoplastic resin and molding is not particularly limited as long as the molded product has the surface structure described above, but the fine shape is heated on the surface of the mold by heating to a temperature at which the thermoplastic resin is softened. A method of transferring and molding the shape is preferred. In view of obtaining the excellent effect of the present invention, injection molding, vacuum molding, pressure molding or hot press molding is preferable. Among these, injection molding is more preferable because mass production is possible.

<3-2-1. Injection molding>
Injection molding is a method in which an injection molding machine is used to mold the above-mentioned mold, which is heated and softened until it becomes a certain low viscosity, filled with injection pressure and filled into the mold, A thermoplastic resin heated and melted is placed in a mold and solidified.

  The injection molding apparatus used in the present invention is not particularly limited, and a general injection molding apparatus can be used. A cavity is formed between a pair of molds having a movable side mold plate and a fixed side mold plate, and the movable side mold plate side in the cavity and An injection molding apparatus in which a mold having a fine shape on the surface is provided on the inner surface of the fixed-side template is preferable. Further, it is preferable that a nozzle is installed so as to communicate with the cavity, and a melted thermoplastic resin is supplied into the cavity, and further, a deaeration hole is formed.

  The inside of the cavity of the injection molding apparatus thus configured is degassed from the deaeration holes, injected and filled with the molten thermoplastic resin from the nozzle, spread over the thermoplastic resin, then cooled, after cooling, The molded product of the present invention can be obtained by opening the mold and taking out the molded product. In the series of steps described above, it is preferable to deaerate the inside of the cavity to make it vacuum, and it is preferable to perform the deaeration before filling the cavity with the thermoplastic resin. Deaeration is performed using a vacuum pump through a deaeration hole. Since filling the thermoplastic resin may generate gas due to decomposition or reaction of the thermoplastic resin, it is preferable to continue degassing during the filling step. This vacuum state is released immediately before the mold is opened.

  One or two or more nozzles may be used to supply the molten thermoplastic resin. Moreover, even if it fills with 1 type of thermoplastic resins, you may fill with 2 or more types of thermoplastic resins. Two-color molding that uses one resin, molds the part to be formed with that resin, and makes it as a semi-finished product, sets the semi-finished product in a mold, and then molds by supplying other resin The method can also be used.

<3-2-2. Vacuum forming>
In the vacuum molding in the present invention, the above-mentioned mold is pressed against a sheet-like thermoplastic resin heated until it is softened to a certain extent, and air is drawn out from the gap between the thermoplastic resin and the mold to bring it into a vacuum state to be adhered. This is a molding method. The molding conditions for vacuum molding may be appropriately adjusted depending on the thermoplastic resin used. A general-purpose apparatus can also be used for vacuum forming.

  Before removing the gas such as air sufficiently from the inside of the fine shape existing on the surface of the mold, by sufficiently extracting the air from the gap between the sheet-shaped thermoplastic resin and the mold, and then leaving it in a high vacuum state. In order to spread the thermoplastic resin to the inside of the fine shape, it is preferable that the thermoplastic resin is closely attached to the mold. Thereafter, the molded product of the present invention can be obtained by cooling and, after cooling, opening the mold and taking out the molded product.

<3-2-3. Compressed air molding>
In the pressure molding, the above-mentioned mold is pressed against a thermoplastic resin heated to a softening temperature, preferably a sheet-shaped thermoplastic resin, and compressed air is put on the thermoplastic resin side to bring the thermoplastic resin into close contact with the mold. This is a molding method. Even in this case, it is preferable to sufficiently evacuate the air from the gap between the sheet-like thermoplastic resin and the mold and leave it in a high vacuum state so that the thermoplastic resin reaches the inside of the microstructure. That is, it is preferable to combine the vacuum forming in the present invention with vacuum forming.

  The pressure forming combined with the vacuum forming is preferable in terms of good moldability of portions other than the fine structure because a high pressure is obtained in addition to the negative vacuum pressure in the vacuum forming. The molding conditions for the pressure molding may be adjusted as appropriate depending on the thermoplastic resin used.

<3-2-4. Hot press molding>
The hot press molding in the present invention is a method in which the above-described mold is pressed against a thermoplastic resin using a press machine with a built-in heating device, and heat compression molding is performed. The above-described vacuum forming, pressure forming, and the like are not forming methods having a parallel relationship but a forming method according to the above definition. Even in this case, it is preferable to sufficiently evacuate the air from the gap between the thermoplastic resin and the mold and leave it in a vacuum state so that the thermoplastic resin reaches the inside of the fine structure. That is, it is preferable to combine the hot press molding in the present invention with vacuum molding.

  The molding conditions for hot press molding may be appropriately adjusted depending on the thermoplastic resin used, and are not particularly limited. The molding temperature is preferably 5 to 20 ° C. higher than the melting point or softening point of the thermoplastic resin, and 5 MPa. A pressure of ˜20 MPa is preferred.

[Action / Principle]
It is not clear about the action / principle that can efficiently and simply provide a molded product excellent in light reflection prevention effect, light transmission performance, etc., and the present invention is not limited by the following action / principle, It is considered as follows. The shape on the surface of the anodized film is fine enough to obtain a very special shape on the surface of the molded product of the present invention. The thermoplastic resin is also applied to the inside of the fine shape by a thermal transfer molding method. It is thought that the reason why it can be spread is that the gas intervening there can be sufficiently removed.

  In addition, when an anodized film on the surface of an aluminum material is used as a mold, the molded body of the present invention has an excellent antireflection effect and light transmission performance, because it is because the surface of the aluminum material that becomes the mold is polished. Conceivable. Conventionally, since the surface of the aluminum material used as a mold is anodized, it has been thought that it is not necessary to polish the surface prior to that. In addition, reflection can be prevented by a specific surface structure, and it was considered that it was sufficient for haze, so it is considered that no further light transmission performance was required. In the past, emphasis was placed only on creating a microstructure with anti-reflection effect for the time being, and the haze was extremely low, specifically to a technical level that only attempted to reduce it to 15% or less. Therefore, it is thought that it was impossible to think of polishing the mold surface.

  The action / principle that can reduce the haze to 15% or less by polishing the aluminum surface prior to anodization is not clear, and the present invention is not limited by the following action / principle, but is considered as follows. That is, since irregularities or non-uniformity of a size that is larger in order or longer than the fine shape of a specific surface that is effective in preventing reflection of the molded article of the present invention affects the haze, such irregularities or It is considered that the haze was lowered because the non-uniformity was removed by polishing. Although anodization can produce a fine shape on the aluminum surface, such orderly large unevenness or nonuniformity is not completely eliminated, and a microstructure is formed on aluminum having orderly large unevenness or nonuniformity. Even so, the haze improvement seems to have been limited.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these, unless the summary is exceeded.

Example 1
<Production of mold>
As an aluminum material, a 99.85% rolled aluminum plate (thickness 2 mm) is polished for 10 minutes using a single-sided flat buffing machine (manufactured by Speedfam) using an alumina-based abrasive (manufactured by Fujimi Abrasives). A mirror surface was obtained. The polished surface was scrubbed and then subjected to non-erodible degreasing treatment. When Ra and Ry of the obtained surface were measured according to JIS B0601 (1994), they were Ra = 0.035 (μm) and Ry = 0.45 (μm).

Furthermore, a mold having tapered pores was produced by a combination of the following anodic oxidation conditions and the following etching (pore diameter expansion) treatment conditions for the formed anodic oxide coating.
<Conditions for anodization>
Working solution: 0.05M oxalic acid voltage: DC voltage temperature of 80V: 5 ° C
Time: 50 seconds

<Etching conditions>
Working solution: 2% by mass Phosphoric acid temperature: 50 ° C
Time: 5 minutes

  By repeating the anodization and etching (pore size expansion) five times alternately, the surface of the anodized film has tapered pores with a period of 200 nm, a pore diameter opening portion of 160 nm, a bottom portion of 50 nm, and an average pore depth of 500 nm. Got the mold. An electron micrograph of the obtained mold is shown in FIG.

<Manufacture of molded products>
After heating the above-mentioned mold to 150 ° C., it is pressed for 1 hour at a pressure of 10 MPa on both sides of a polymethyl methacrylate base material (manufactured by Mitsubishi Rayon Co., Ltd., trade name Acrylite L) which is a thermoplastic resin. Then, by cooling to 70 ° C. or lower, a molded product having convex portions with an average height of 500 nm on the surface with an average period of 200 nm was obtained. In FIG. 2, the electron micrograph of the cross section of the surface of the obtained molded article is shown.

  The arithmetic average roughness (Ra) of the fine uneven slope of this molded product is 30 nm, and the reflectance after the visibility correction is performed by the following measurement method, in all wavelength regions of 380 nm to 780 nm. It was 0.5% or less. The haze was 10.5%. “Reflectance spectrum after correcting visibility” measured in a wavelength region of 380 nm to 780 nm is shown in FIG.

<Measurement of arithmetic average roughness (Ra) of fine shape>
The arithmetic average roughness (Ra) of the fine shape of the obtained molded product was measured according to JIS B0601 (1994).

<Measurement of reflectance after correction of visibility>
Using a self-recording spectrophotometer "UV-3150" manufactured by Shimadzu Corporation, attaching a black tape on the back surface, and changing the amount of transmitted light to human eye sensitivity (standard relative luminous sensitivity curve) in the wavelength range of 380 nm to 780 nm. A normal visibility correction filter corrected together was attached, and the 5 ° regular reflectance was measured to obtain “the reflectance after visibility correction”.

<Measurement of haze>
Using a haze meter “HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.)”, the haze of visible light was measured according to JIS K7361.

Example 2
<Production of mold>
It is controlled at a room temperature of 25.0 ± 0.1 ° C at the central part of the core on the movable side of the mold for injection molding of a flat plate with a length of 100 mm and a thickness of 1.0 mm. In a constant temperature room, using a micro cutting machine (Nagase Integrex Co., Ltd., ultra-precision 5-axis CNC control micro processing machine NIC200) and a single crystal diamond tool with a surface arithmetic average roughness (Ra) of 3 nm, pore diameter opening A conical pore having a portion of 160 nm and a pore depth of 500 nm was processed to a period of 200 nm to obtain a mold having a fine concave shape on the entire surface of 30 mm × 30 mm.

<Manufacture of molded products>
Using an injection molding machine (Nippon Steel Works, JSW-ELIII, mold clamping force 1MN) equipped with the mold obtained above, polymethylmethacrylate (PMMA) (manufactured by Sumitomo Chemical Co., Ltd., The product name MG5) was injection molded under the conditions of a resin temperature of 290 ° C. and a mold temperature of 80 ° C., a square with a side length of 100 mm, a thickness of 1.0 mm, and a convexity with an average height of 500 nm on the surface. A molded product having parts with an average period of 200 nm was obtained. The arithmetic average roughness (Ra) of the fine uneven slope of this molded product was 45 nm, and the reflectance after the visibility correction was 0.5% or less in all wavelength regions from 380 nm to 780 nm. . The haze was 8.5%.

Example 3
<Manufacture of molded products>
In Example 2, the thermoplastic resin used to produce the molded product was changed to polycarbonate instead of polymethyl methacrylate (PMMA), and the resin temperature during injection molding was changed to 300 ° C. and the mold temperature was changed to 90 ° C. In the same manner as in Example 2, a molded product having a square with a side length of 100 mm, a thickness of 1.0 mm, and convex portions with an average height of 500 nm on the surface was obtained with an average period of 200 nm. The arithmetic average roughness (Ra) of the fine uneven slope of this molded product was 40 nm, and the reflectance after the visibility correction was 0.4% or less in all wavelength regions of 380 nm to 780 nm. . The haze was 9.0%.

Example 4
<Manufacture of molded products>
Under the same conditions as in Example 1, a mold for vacuum forming having an anodized film surface having tapered pores with a period of 200 nm, a pore diameter opening portion of 160 nm, a bottom portion of 50 nm and an average pore depth of 500 nm was obtained. . Using this mold, a polymethylmethacrylate (PMMA) sheet (product name: Acrylite L, manufactured by Mitsubishi Rayon Co., Ltd.) is used as a thermoplastic resin with a vacuum molding machine (FE38PH manufactured by Hermis Co., Ltd.). When vacuum molding was performed at 80 ° C., a molded product having a square with a side length of 100 mm, a thickness of 1.0 mm, and convex portions having an average height of 450 nm on the surface was obtained with an average period of 200 nm. . The arithmetic average roughness (Ra) of the fine uneven slope of this molded product is 35 nm, and the reflectance after the visibility correction is 0.5% or less in all wavelength regions of 380 nm to 780 nm. It was. The haze was 11.0%.

Example 5
<Manufacture of molded products>
Using the mold obtained in Example 1, using a vacuum / pneumatic molding machine (manufactured by Asano Laboratories, FK-0431-10), a polymethyl methacrylate (PMMA) sheet (manufactured by Mitsubishi Rayon Co., Ltd.) as a thermoplastic resin. The product name Acrylite L) was vacuum-pressure molded under conditions of 0.4 MPa at a resin temperature of 180 ° C. and a mold temperature of 80 ° C., and it was a square with a side of 100 mm and a thickness of 1.0 mm. A molded product having convex portions with an average height of 450 nm on the surface with an average period of 200 nm was obtained. The arithmetic average roughness (Ra) of the fine uneven slope of this molded product is 40 nm, and the reflectance after the visibility correction is 0.5% or less in all wavelength regions of 380 nm to 780 nm. It was. The haze was 10.0%.

Example 6
Instead of mechanical polishing using an alumina-based polishing material in Example 1, except for chemical polishing while shaking for 3 minutes in a polishing solution obtained by mixing at 95 ° C. and 60% by volume phosphoric acid and 5% by volume nitric acid. Obtained a mold in the same manner as in Example 1. The Ra and Ry on the surface of the above-mentioned “aluminum material processed by chemical polishing” were measured according to JIS B0601 (1994), and Ra = 0.035 (μm) and Ry = 0.45 (μm). there were.

  When this mold was used and molded in the same manner as in Example 1, a molded product having convex portions with an average height of 500 nm on the surface with an average period of 200 nm was obtained. The arithmetic average roughness (Ra) of the fine uneven slope of this molded product is 30 nm, and the reflectance after the visibility correction is 0.4% or less in all wavelength regions of 380 nm to 780 nm. It was. The haze was 10.0%.

Example 7
Instead of polishing with an alumina-based polishing material in Example 1, electrolytic polishing was performed in a 90 ° C., 90% by volume phosphoric acid bath while vibrating at a current density of 40 A / dm ² for 5 minutes using an aluminum material as a positive electrode. Thereafter, a mold was obtained in the same manner as in Example 1 except that the surface oxide film was dissolved and removed by immersion in a 20 ° C. nitric acid bath (commercially about 68% nitric acid diluted twice) for 10 minutes. It was. The Ra and Ry on the surface of the above “aluminum material processed by electrolytic polishing” were measured in accordance with JIS B0601 (1994). Ra = 0.035 (μm), Ry = 0.45 (μm) there were.

  When the mold was used and molded in the same manner as in Example 1, a molded product having convex portions with an average height of 500 nm on the surface with an average period of 200 nm was obtained. The arithmetic average roughness (Ra) of the fine uneven slope of this molded product is 30 nm, and the reflectance after the visibility correction is 0.4% or less in all wavelength regions of 380 nm to 780 nm. It was. The haze was 9.0%.

Example 8
In Example 2, instead of using the thermoplastic resin polymethyl methacrylate, polyethylene terephthalate (manufactured by Nippon Unipet Co., Ltd., trade name: UNIPET, grade: RT553C) was used, and the resin temperature was 290 ° C. and the mold temperature was 25 ° C. Except for the above, a molded product was produced in the same manner as in Example 2 to obtain a molded product having convex portions with an average height of 500 nm on the surface with an average period of 200 nm. The arithmetic average roughness (Ra) of the fine irregular slope of this molded product is 45 nm, and the reflectance after the visibility correction is 0.5% or less in all wavelength regions of 380 nm to 780 nm. It was. The haze was 9.5%.

Comparative Example 1
A photocurable composition containing a polyfunctional acrylate compound and a photopolymerization initiator was collected on a PET film and coated with a bar coater NO28 so as to have a uniform film thickness. Thereafter, the mold obtained in Example 1 was bonded, and it was confirmed that the photocurable composition was filled in the pores. After curing, the film was peeled off from the mold to obtain a film having an antireflection effect in which convex portions having an average height of 500 nm existed on the surface with an average period of 200 nm. It was necessary to use it as having an antireflection effect.

Example 9
In Example 1, a mold was obtained in the same manner as in Example 1 except that the aluminum material was not polished. The Ra and Ry on the surface of the unpolished aluminum material were measured according to JIS B0601 (1994), and were Ra = 0.50 (μm) and Ry = 2.00 (μm).

  When this mold was used and molded in the same manner as in Example 1, a molded product having convex portions with an average height of 500 nm on the surface with an average period of 200 nm was obtained. The arithmetic average roughness (Ra) of the fine uneven slope of this molded product is 450 nm, and the reflectance after the visibility correction is 0.5% or less in all wavelength regions of 380 nm to 780 nm. It was. The haze was 39.5%.

  Each of the molded products obtained in Examples 1 to 8 has a convex portion having an average height of 100 nm or more and 1000 nm or less or a concave portion having an average depth of 100 nm or more and 1000 nm or less on the surface thereof. The haze was 12% or less in any one direction with an average period of 50 nm to 400 nm. The reflectivity after the visibility correction was 0.5% or less in all wavelength regions of 380 nm to 780 nm in all of Examples 1 to 3 to 9. Moreover, when the transparency of the molded product was judged by visual observation, all were very good. That is, the molded product of the present invention had an excellent antireflection effect of light and an excellent light transmission performance.

  On the other hand, although what was obtained in Comparative Example 1 had an antireflection effect for light, it was not possible to easily obtain an antireflection effect.

  Further, the molded product obtained in Example 9 had a very good reflectivity after the visibility correction, but the haze was 39.5%, which was very large compared to the molded products of Examples 1-8.

  Since the molded product of the present invention is excellent in the antireflection effect of light, excellent light transmission performance, etc., a lens, a meter front cover, a window plate, a headlight cover, a show window, etc .; (LCD), plasma display (PDP), organic EL (OEL), CRT, field emission display (FED) and other flat panel displays (FPD), etc.

Claims (9)

  A molded product obtained by using a mold having a fine shape on the surface and thermally transferring and molding the fine shape on the surface of the mold onto a thermoplastic resin, and having an average height of 100 nm or more and 1000 nm or less on the surface. A molded product having a recess having a depth of 100 nm or more and 1000 nm or less, and the protrusion or recess having an average period of 50 nm or more and 400 nm or less with respect to at least one direction.   The molded article according to claim 1, wherein the method of thermally transferring and molding the fine shape onto a thermoplastic resin is a method by injection molding, vacuum molding, pressure molding or hot press molding.   The mold having a fine shape on the surface is a mold in which a fine shape is formed on the surface of an aluminum material by a combination of formation of an anodized film by anodization and etching of the anodized film. The molded product according to claim 2.   A mold having a fine shape on the surface, after the surface of the aluminum material is processed by mechanical polishing, chemical polishing and / or electrolytic polishing, an anodized film is formed on the surface of the aluminum material by anodization, and the anodized The molded article according to claim 3, which is a mold formed by forming a fine shape by combination with etching of a film.   The molded article according to claim 4, wherein the surface of the aluminum material after being processed by mechanical polishing, chemical polishing and / or electrolytic polishing has an arithmetic average roughness Ra of 0.1 μm or less.   6. The anodic oxidation is performed at an oxalic acid concentration of 0.01 M to 0.5 M, an applied voltage of 20 V to 120 V, and a liquid temperature of 0 ° C. to 50 ° C. 6. The molded product according to claim.   The etching is performed at a phosphoric acid concentration of 1% by mass to 20% by mass, a liquid temperature of 30 ° C to 90 ° C, and a single treatment time of 1 minute to 60 minutes. The molded product according to any one of claims.   The molded article according to any one of claims 1 to 7, wherein the thermoplastic resin is a vinyl resin, a polycarbonate resin, or a polyester resin.   The molded article according to any one of claims 1 to 8, wherein the reflectance after the visibility correction is 0.5% or less in all wavelength regions of 380 nm or more and 780 nm or less.