JP2010125669A - Production method for dual molding decorative article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method for a dual molding decorative article with a concavo-convex shaped nano structure on its surface using a molding die with the concavo-convex shaped nano structure formed on its surface. <P>SOLUTION: Production process of the dual molding decorative article 20 with a micro concavo-convex formed on its surface sets a decorative article 10 to a molding die 5 countering a molding die 3 (see (1) of Fig.1) using the molding die 3 having a nest member 9 with the concavo-convex shaped nano structure formed on its surface and fills a cavity 6 formed between the molding die 3 and the molding die 5 with a molding resin 2 by injection compression molding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a double-shaped decorative article in which minute irregularities are formed on the surface of a decorative article using a molding die having a nano-structure irregular shape formed on the surface.

  Recently, for example, a thermal nanoimprint method as disclosed in Patent Document 1 has attracted attention as a method for forming a concavo-convex shape of a nanostructure on the surface.

In the thermal nanoimprint method, a stamper made of nickel electroforming is produced from a base mold drawn with an electron beam, etc., placed on a base sheet, pressed under high temperature and high pressure, cooled, and then the stamper is This is a method in which a minute recess is formed on the substrate sheet or the like by removing it from the substrate sheet 1 or the like. The temperature at the time of pressing is set to be higher than the softening point of the base sheet or the like and lower than the thermal decomposition temperature, and the pressure is generally set to several MPa to several tens of MPa. After pressing for several seconds to several minutes, the substrate sheet is left to stand until the surface of the base sheet or the like is below the softening point by rapid cooling or natural cooling.
JP 2008-49544 A

  However, in thermal nanoimprinting, it is necessary to apply uniform and appropriate heat and pressure with high accuracy using a very high-precision mold having nano-structured irregularities formed on the surface. Therefore, it can be applied only to a smooth resin sheet of a small size, and cannot be applied to a material that is difficult to apply pressure and heat uniformly, such as a three-dimensional injection molded product. In addition, using an injection mold with a nano-structured rugged shape formed on the surface used for thermal nanoimprinting, even when trying to obtain a three-dimensional injection molded product by the usual insert molding painting method, There was a problem that a desired nanostructure surface such as thermal nanoimprint could not be obtained without following.

  Therefore, the present invention eliminates the above-described problems, and a method for producing a double-molded decorative article that forms a nanostructure uneven shape on the surface using a molding die having a nanostructure uneven shape formed on the surface. The purpose is to provide.

  In order to achieve the above object, the method for producing a double-shaped decorative article of the present invention is configured as follows.

  That is, the method for producing a double-molded decorative article of the present invention uses a molding die having a nano-structured concavo-convex shape formed on the surface thereof, on the molding die side facing the molding die having the nano-structure concavo-convex shape. A method for producing a double-molded decorative product in which a decorative product is set, both molds are clamped, the cavity is filled with a molding resin, the mold is opened, and fine irregularities are formed on the surface of the decorative product. The ornament was set on the side of the molding die facing the molding die having the concavo-convex shape of the nanostructure, and after mold clamping, the molding resin was filled by injection compression molding.

  Further, in the method for producing a double molded decorative article according to the second aspect of the present invention, the uneven structure portion of the nanostructure is nested in the mold having the uneven structure of the nanostructure. The child was provided with a compression mechanism, and after filling with molding resin, the nest part was compressed.

  Further, in the method for producing a double molded decorative article according to the third aspect of the present invention, the uneven structure portion of the nanostructure is nested in the mold having the uneven structure of the nanostructure. The mold temperature of the child portion was set to be higher than the mold temperature of the surrounding portion.

  Moreover, the double-shaped decorative article of the fourth aspect of the present invention was configured such that the fine irregularities of the nanostructure formed on the surface had a moth-eye shape.

  Moreover, the double-shaped decorative article of the fifth aspect of the present invention was configured such that the fine irregularities of the nanostructure formed on the surface had a microlens array shape.

  The method for producing a double-molded decorative product of the present invention uses a molding die having a nano-structured concavo-convex shape on the surface, and is a decorative product on the molding die side facing the molding die having the nano-structured concavo-convex shape. Is a method of manufacturing a double-molded decorative product in which both molds are clamped, a mold resin is filled in the cavity, the mold is opened, and minute irregularities are formed on the surface of the decorative product. Since the mold resin is filled by injection compression molding after being set on the side of the mold opposite to the mold having the nanostructure irregularities, the nanostructure is easily formed on the mold resin surface. it can.

  Therefore, a desired nanostructured surface such as thermal nanoimprint can be obtained on the surface of the molded product, and it has surface properties with superior performance such as antireflection, lens effect, tactile sensation, super water repellency, security hologram, etc. There is an effect that a molded product can be obtained.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an end view showing an example of a method for producing a double-shaped decorative article in which nano-structured micro unevenness is formed on the surface of the present invention, and FIG. 2 shows nanostructure micro-unevenness on the surface of the present invention. It is an end elevation which shows another example of the manufacturing method of the double molded decorative article formed. FIG. 3 is a schematic cross-sectional view of a double-molded decorative article manufactured by the manufacturing method (1) shown in FIG. 1, and (2) is an enlarged schematic view of the micro unevenness shown in (1). (3) is an enlarged schematic diagram showing a modified example of the micro unevenness shown in (1).

  The manufacturing method of the double-shaped decorative article 20 (see (1) in FIG. 3) in which minute irregularities are formed on the surface of the present invention is a molding metal having a nesting portion 9 having a nanostructure irregular shape formed on the surface. Using the mold 3, the decorative product 10 is set on the molding mold 5 facing the molding mold 3 (see (1) in FIG. 1 and (1) in FIG. 2), and the molding mold 3 and the molding mold are set. 5 is filled with the molding resin 2 by injection compression molding. As a method of injection compression molding, the molding die 3 and the molding die 5 are held in a slightly opened state, and after the molding resin 2 is injected, before the molding resin 2 cools and hardens, the molding die 3 and In addition to the method of closing the molding die 5 and compressing the molding resin 2 (see FIG. 1), a part of the molding die 3 is nested, and the molding die 3 and the molding die 5 are closed. There is a method in which, after the molding resin 2 is injected, before the molding resin 2 cools and hardens, the nest advances by hydraulic pressure or the like to compress the molding resin 2 (see FIG. 2).

  Next, the molding die 3 having an uneven surface with a nano structure formed on the surface will be described. In principle, the molding die 3 on which the decorative article 10 is set is combined with the molding die 5 to form the cavity 6. As the material of the molding die 3, a steel material such as a copper alloy or an aluminum alloy used in a normal injection molding die is used. The molding die must be rigid enough not to be deformed by the pressure of hot water. In addition, the material of the metal mold | die of the shaping die 3 and the shaping die 5 may be the same, and may differ. Examples of a method for forming a nanostructure uneven shape on the molding die 3 include electron beam drawing and machining.

  Note that the nano-structured minute uneven portion 4 in the molding die 3 is a nested portion 9, which is connected to a mold temperature control mechanism different from the mold temperature control mechanism in the surrounding portion, and the nested portion It is preferable to set the mold temperature of 9 to be higher than the mold temperature of the surrounding portion. Depending on the shape of the minute irregularities, it may be insufficient to form the minute irregularities 4 of the molding die 3 accurately on the surface of the molding resin 2 even by injection compression molding. This is because by increasing the mold temperature, the nano-structured micro unevenness 8 is more accurately formed on the surface of the molding resin 2.

  Examples of the uneven structure of the nanostructure formed on the surface of the molding die 3 include: (1) A pyramid with a draft angle θ of 20 to 50 degrees or a conical pyramid-shaped pillar with a pitch L of 100 to 500 nm. A shape (see (2) in FIG. 3) having an orderly arranged structure (hereinafter referred to as a moth-eye structure) (see (2) of FIG. A shape (see (3) of FIG. 3) that exhibits a lens effect with a structure (hereinafter, referred to as a microlens array structure) arranged in an orderly manner with a pitch L of 5 μm to 100 μm, and a reverse pattern thereof. In addition, the shape which exhibits a rainbow-colored hologram design, the mat | matte shape which exhibits a matte effect, etc. may be sufficient. These may be formed partially or entirely. Further, only one of these shapes may be formed, or a combination of a plurality of shapes may be used.

  In addition, it is preferable to provide the formation position of these uneven | corrugated shapes of nanostructure in the position which can synchronize with the design pattern of the decorative article 10. For example, an uneven shape with a moth-eye structure is formed in a colorless and transparent display window, and an uneven shape with a microlens array structure is provided in the colored design portion, thereby making the display screen clearer due to the antireflection effect and the colored design. A deep design is formed in the portion by the lens effect.

  Next, the decorative product 10 will be described. The decorative product 10 of the present invention has at least a design layer formed on the surface of a molded product, and an adhesive layer for improving the adhesion with the molding resin 2 as necessary, or between these layers. An anchor layer or the like for improving adhesion is installed. In addition to the case where a desired colored ink is formed in a single layer or a plurality of layers in a desired pattern, the design layer may be formed with a metal vapor deposition layer or the like to express a design with metallic luster. The material of the pattern layer is not particularly limited as long as it has printability and various resistances, and examples thereof include resins such as acrylic, urethane, polyvinyl chloride, polyamide, polyester, and polypropylene.

  In the injection molding method of the double molded decorative article 20 of the present invention, in particular, among the molds having the nanostructured uneven shape, the nanostructured uneven portion is nested and the nested portion is compressed. Such a configuration is preferable because pressure is concentrated on the interface of the uneven structure portion of the nanostructure, and the nanostructure minute unevenness 8 is more accurately formed on the surface of the decorative article 10.

  The molding resin 2 is not particularly limited, such as a normal thermoplastic injection molding resin or engineering plastic, or a thermosetting molding resin material, but a resin that is easy to mold and has good adhesion to the thermosetting paint 8 is preferable. Specific examples include acrylonitrile butadiene styrene resin (ABS resin), polyamide resin, polyethylene resin, polyester resin, polypropylene resin, polybutylene terephthalate resin, and polycarbonate resin.

  A nested mold C having a micro uneven shape (a moth-eye structure in which pyramid-shaped pyramids having a 30-degree gradient pyramid are regularly arranged at a pitch of 300 nm) with a mold temperature set to 70 ° C. has a mold temperature of 50 ° C. The base sheet is formed of a colorless and transparent acrylic film with a thickness of 200 μm, which is inserted into the set mold A and the mold temperature is set to 50 ° C. as in the mold A. A decorative product made of an acrylic molding resin with a decorative sheet coated on the surface was set. After that, the mold A and the mold B are clamped, and a colorless and transparent ABS resin is injected into the formed cavity, and after 0.3 seconds, the telescopic mold C is melted by a hydraulic mechanism. After applying a pressure of 10 atm to the ABS resin, the mold is cooled while being held for 40 seconds in that state, and the molding die B is opened. A decorative product was obtained. When the surface of the obtained double molded decorative article is observed with an electron microscope, a pattern almost the same as the inverted pattern of the moth-eye structure formed on the surface of the mold C is one of the surfaces of the double molded decorative article. Was formed in the part. When the reflectance of the surface on which this pattern was formed was measured, the reflectance was 0.83%, which was a significant anti-reflection effect compared to the reflectance of 4% at the portion where the pattern was not formed.

  Nesting mold C having a micro uneven shape (microlens array structure in which hemispherical convex portions having a curvature radius of 150 μm are regularly arranged at a pitch of 50 μm) with a mold temperature set to 60 ° C. has a mold temperature of 40 ° C. A colorless and transparent vinyl chloride with a base sheet thickness of 100 μm between the molding die A and the molding die B whose mold temperature is set to 40 ° C. as in the molding die A. A decorative product made of an ABS molding resin having a surface coated with a wood grain decorative sheet made of a film was set. Thereafter, the molding die A and the molding die B are clamped, the molten brown heat-resistant ABS resin is injected into the formed cavity, and the molding die B is cooled while being held in that state for 40 seconds. By opening, a double molded decorative article having a micro uneven shape formed on the surface was obtained. When the surface of the obtained double molded decorative article was observed with an electron microscope, a pattern almost the same as the inverted pattern of the microlens array structure formed on the surface of the molding die C was the double molded decorative article. It was formed on a part of the surface. The surface on which this pattern was formed was a wood grain molded product exhibiting an excellent design in which the wood grain pattern can be viewed three-dimensionally due to the surface nanostructure exhibiting the lens effect.

  Example 2 except that the concavo-convex shape of the nested mold C was formed into a continuous straight V-shaped groove arranged in an orderly manner at a gradient of 45 ° and a pitch of 2 μm, the decorative sheet was made of a silver metallic pattern, and the molding resin was a black ABS resin. In the same manner as above, a double molded decorative article was obtained. When the surface of the obtained double molded decorative article is observed with an electron microscope, a pattern almost the same as the inverted pattern of the continuous straight V-shaped groove structure formed on the surface of the molding die C is applied to the double molded decorative article. It was formed on a part of the surface of the ornament. The surface on which this pattern was formed was a glittering molded product exhibiting an excellent design that looked rainbow-colored due to the nanostructure of the surface exhibiting the light interference effect.

  Without using the insert mold C, with the molding mold A and the molding mold B being slightly opened, the black ABS resin was injected and melted with a clamping pressure of 220 tons 0.1 seconds later. A double-molded decorative article was obtained in the same manner as in Example 3 except that the pressure was applied to the ABS resin and the mold B was opened by cooling while maintaining the pressure for 40 seconds. When the surface of the obtained double molded decorative article is observed with an electron microscope, a pattern almost the same as the inverted pattern of the continuous straight V-shaped groove structure formed on the surface of the molding die C is applied to the double molded decorative article. It was formed on a part of the surface of the ornament. The surface on which this pattern was formed was a glittering molded product exhibiting an excellent design that looked rainbow-colored due to the nanostructure of the surface exhibiting the light interference effect.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used in various molded products such as communication devices such as mobile phones, electronic information devices, liquid crystal displays, automobile interior and exterior parts, and is industrially useful.

It is an end elevation which shows an example of the manufacturing method of the double shaping | molding decorating article in which the micro unevenness | corrugation of nanostructure is formed in the surface of this invention. It is an end elevation which shows another example of the manufacturing method of the double shaping | molding decorating article by which the micro unevenness | corrugation of nanostructure is formed in the surface of this invention. (1) is a schematic cross-sectional view of a double molded decorative article manufactured by the manufacturing method shown in FIG. 1, and (2) is an enlarged schematic view of the micro unevenness shown in (1). (3) is the enlarged schematic diagram which showed the modification of the micro unevenness | corrugation shown by the (1).

Explanation of symbols

2 Molding Resin 3 Molding Mold with Nanostructured Micro-Roughness Shape on Surface 4 Nanostructured Micro-Roughness Shaped Part in Molding Mold 5 Molding Die Opposing Molding Mold 6 Molding Mold 3 and Molding Mold Cavity formed by mold 5 Nano-structured micro unevenness on double-molded decorative product surface 9 Nested part of molding die 3 10 Decorated product 20 Double-molded decorative product formed with nano-structured micro unevenness

Claims (5)

Using a molding die with a nano-structured concavo-convex shape on the surface, set a decorative product on the molding die side facing the molding die with the nano-structured concavo-convex shape, after clamping both dies, Filling the cavity with a molding resin, opening the mold, and forming a micro unevenness on the decorative product surface,
A method for producing a double-molded decorative article, wherein the decorative article is set on the side of a molding die facing the molding die having a concavo-convex shape of the nanostructure, and after clamping, the molding resin is filled by injection compression molding.   Of the molds with the nano-structured concavo-convex shape, the nano-structure concavo-convex shape portion is nested, and a compression mechanism is given to the nesting portion, and after filling the molding resin, the nesting portion is compressed. The method for producing a double-molded decorative article according to claim 1.   Among the molds having the nano-structured concavo-convex shape, the nano-structure concavo-convex shape portion is nested, and the mold temperature of the nesting portion is higher than the mold temperature of the surrounding portion. The method for producing a double-molded decorative article according to claim 1 or 2, which is set.   A double-molded decorative article having fine irregularities formed on the surface thereof, the minute irregularities being a moth-eye shape.   A double-molded decorative article having a micro unevenness formed on the surface thereof, wherein the micro unevenness is a microlens array shape.

Images