JPS62119100A - Manufacture of hologram decorative resin molded shape - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a hologram decorative resin molded product, and more specifically, an object of the present invention is to easily and inexpensively provide a resin molded product having a hologram on the surface. do.

(Prior Art) Conventionally, various resin molded products have been widely manufactured and used, and these resin molded products are provided with various colors and patterns to enhance their cosmetic and design effects. As a means of imparting such cosmetic and design effects, it is also practiced to impart a hologram that gives a three-dimensional visual sensation to the surface of a resin molded article.

Methods for imparting a hologram to the surface of a resin molded product include (1) forming a layer made of photosensitive resin on the surface of the resin molded product and directly forming a hologram with a laser beam, etc., (2) forming a hologram with an uneven shape. (3) A method of thermally transferring the uneven shape of a hologram onto the surface of a resin molded product using a hologram transfer sheet is known. There is.

(Problems to be Solved by the Invention) In the method (1) above, it is necessary to apply a photosensitive resin and irradiate each resin molded product with a laser beam, and the laser beam irradiation equipment etc. are expensive. Method (2) above, which cannot be mass-duplicated and has low industrial practicality, cannot be applied to anything other than resin molded products with flat surfaces, and holograms cannot be applied to uneven or curved surfaces of molded products. You can also do the above (
In method 3), resin molded products generally have poor heat resistance, so during thermal transfer, the uneven shape of the hologram may be deformed by the heat during transfer, or air bubbles may be mixed into the transfer surface during transfer, or dust may adhere. This causes various problems. Furthermore, as a result of heating one side of the resin molded product, the resin molded product is likely to be deformed such as warping, and furthermore, since the molded product and the hologram are not fully integrated, the hologram is likely to peel off.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a high-quality hologram decorative resin molded product at low cost and easily.

(Means for Solving the Problems) As a result of intensive research in order to solve the problems of the prior art described above and achieve the object of the invention described above, the present inventors have found that, in order to solve the problems of the prior art described above, and to achieve the object of the present invention described above, the present inventors have developed a method for injection molding of synthetic resins that is conventionally known. The present invention was completed based on the finding that the object of the present invention can be achieved by providing a hologram master plate in advance on at least a portion of the inner wall of the mold and performing injection molding.

That is, the present invention provides a method for manufacturing a resin molded product by injection molding, in which a hologram master plate is provided on at least a portion of the inner wall of a mold and injection molding is performed, and the uneven surface of the hologram of the obtained resin molded product is This is a method for producing a hologram decorative resin molded product, which is characterized by forming a reflective metal layer on the holographic decorative resin molded product.

The invention will now be explained in more detail with reference to the accompanying drawings, which schematically illustrate the principle of the method according to the invention.

That is, in the method of the present invention, as shown in FIGS. 1 and 2, it is necessary to prepare an injection mold l and provide a hologram master plate 2 on the surface of at least a portion of its inner wall. . Master plates for such holograms include metal master plates in which the uneven shape of the hologram is created by electroforming, and master plates made of heat-resistant resins, such as electron beam-curable, ultraviolet-curable, or thermosetting resins. is preferably used.

Such a metal master plate can be obtained, for example, by plating an appropriate metal, such as nickel, to a thickness of several mm on an original plate having a holographic uneven shape, and then peeling it off from the original plate.

Further, a copy of such a nickel plate made of another metal may also be used.

The above-mentioned resin master plate can be prepared by applying a curable resin, preferably an ultraviolet curable resin or an electron beam curable resin, to a suitable film such as a polyester film, and preparing the coated surface in advance. The curable resin is obtained by superimposing original plates having the concavo-convex shape of the hologram, sufficiently curing the curable resin by irradiating with heat, ultraviolet rays, or electron beams, and then peeling off the original plates. Such a hologram master plate may be flat or curved depending on the shape of the mold.

Next, the master version 2 of the hologram formed as described above.
A mold 1 having a mold 1 is assembled, a molten resin is injected into the cavity of the mold 1 from an injection molding machine, and after cooling, the mold 1 is opened and the resin molded product 3 is taken out, so that at least a part of the surface of the mold 1 is injected. A resin molded product 3 as shown in the third figure having a holographic uneven shape 4 is obtained. Note that the flower patterns shown in Figures 1 to 3 are not actually visible to the naked eye because the reflective metal layer has not yet been formed on the uneven surface of the hologram that forms them. It is shown for convenience of explanation. In this state, the surface of the concavo-convex shape 4 of the resin molded product 3 has insufficient light reflectivity, so by forming a reflective metal layer 5 made of, for example, aluminum on the surface of the concavo-convex shape 4 of the hologram, it is possible to obtain the desired light reflection property. A holographic decorative resin molded article 3 is obtained.

The above is the basic aspect of the production method of the present invention, and the injection molding method used in the above method of the present invention is a molding method that has been very widely used in the field of molding synthetic resins. Thermoplastic resins such as thermoplastic resins, polyolefin resins such as polystyrene and polyethylene, acetyl cellulose, methacrylic resins, polycarbonate resins, polyester resins, polyamide resins, etc. are heated and melted in a cylinder, and then melted with a plunger through a nozzle. In this method, the resin is injected into a cold mold to solidify the resin to obtain a resin molded product.

Various systems of such injection molding methods are widely known, and any of these systems can be used in the present invention, and the mold to which the hologram master plate is attached can also be formed using the above-mentioned known injection molding method. Anything used can be used.

In the present invention, a hologram master plate as described above is attached to the inner wall of a mold and injection molding is performed. By applying a known mold release agent, the mold release properties of the resulting resin molded product can be improved.

The main feature of the present invention is to use a mold provided with such a hologram master plate, and using such a mold, molten resin is injected into the mold and solidified to obtain a resin molded product. All specific conditions can be based on conventionally known methods. Furthermore, the molding method for the resin molded product obtained as described above may be carried out according to a conventionally known method.

On at least a part of the surface of the released resin molded product 3, the uneven shape 4 of the master version of the hologram provided in the mold has been transferred in a reversed manner, and in this state, the uneven shape 4 of the hologram is sufficiently Therefore, it is necessary to provide a light-reflective metal layer 5 on the surface of the uneven shape 4 of these holograms.

The light reflective metal N5 is for imparting light reflectivity to the concavo-convex shape 4 of the hologram, and is made of Cr, Ti, Fe, C
o, Ni, Cu, Ag, Au, Ge, A1. Mg, Sb
, Pb, Pd, Cd, BE, Sn, Se, In, Ga
, Rh and other metals and their oxides, nitrides, etc., alone or in combination of two or more parts. Among these metals, Al, Cr, Ni, Ag, Au, etc. are particularly preferred. The light reflective metal layer 5 preferably has a thickness of io to 800 angstroms, preferably 200 to 500 angstroms. Such a light-reflective metal layer 5 can be easily formed by a conventionally known metal thin film forming technique such as a vacuum evaporation method, a sputtering method, an ion blating method, or the like.

As described above, the desired hologram decorative resin molded product is obtained by the method of the present invention, and this resin molded product has a three-dimensional hologram image formed on its surface, and can be used as is for a variety of purposes. However, depending on the application, surface durability may be required, so in order to protect the reflective metal layer, the surface of the reflective metal layer is coated with light. It is preferable to form a protective layer 6 (FIG. 3) that does not interfere with reflectivity.

Such a protective layer 6 can be easily provided by forming a film using a transparent synthetic resin paint or by laminating transparent films.

Of course, these protective layers 6 may be colored in any hue as long as they are transparent, and by forming a highly transparent colored protective layer, the three-dimensional visibility provided by the hologram can be made more favorable. I can do it. As the paint, clear lacquers such as vinyl chloride-vinyl acetate copolymer resins, nitrocellulose-based, polyurethane-based, polyester-based, and acrylic-based lacquers are suitable. The thickness of these protective layers 6 varies depending on each application and is not particularly limited.

(Function effect) According to the present invention as described above, the uneven shape of the hologram is not formed on the surface of the resin molded product once molded as in the conventional technology, but the uneven shape of the hologram is formed on the resin molding at the same time as the injection molding. Since it is formed on the surface of the product, the process is also simplified, and by using the same mold, many copies can be made, making it very economical.

In addition, when applying the uneven shape of a hologram to a resin molded product by thermal transfer as in the past, the heat during transfer may cause the resin molded product to warp if it is plate-shaped. This method could not be applied to some molded products, but according to the present invention, resin can be applied to any shape of molded product or resin molded products with low heat resistance without any problems. The uneven shape of a hologram can be easily imparted to the surface of a molded product, and furthermore, the hologram formed in this way is completely integrated with the molded product, so it cannot be peeled off under any circumstances. There is no.

Furthermore, when applying holograms using conventional embossing methods, it was difficult to apply holograms to uneven parts and curved parts of molded products, but according to the method of the present invention,
Regardless of the shape of the inner wall of the mold, you can easily create a hologram on any shaped surface of the injection molded product by using a master plate suitable for that shape or by using a flexible master plate. can be granted.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 A hologram was photographed to record an uneven relief shape, and from this relief shape a hologram master plate with a thickness of 3 mm was obtained by electroforming using a photoresist.

This metal master plate was attached to a fixed position on the inner wall of an injection mold. Using this mold, acrylic resin was injection molded under normal conditions to obtain a resin molded product having a holographic uneven shape on its surface.

Next, aluminum was deposited to a thickness of 300 angstroms on the uneven surface of the hologram formed on the surface of the resin molded product. Further, a thermosetting acrylic resin liquid was spray coated on the surface of the reflective metal layer to form a protective layer, thereby obtaining a holographic decorative resin molded article according to the present invention. The surface of this resin molded product had excellent three-dimensional visibility due to the hologram.

Example 2 An ultraviolet curable resin was applied to a thickness of 20 lm on a biaxially stretched polyester film having a thickness of 20 gm, and an original plate with a hologram uneven shape formed in advance on this surface was attached with CP: The curable resin was polymerized and cured by irradiating it with ultraviolet rays to obtain a polyester film having a holographic uneven shape. Using this master plate for hologram makeup made of resin, a resin molded article having an uneven shape of hologram makeup on its surface was obtained in the same manner as in Example 1.

Next, aluminum was vapor-deposited to a thickness of 300 angstroms on the uneven surface of the hologram, and a urethane resin liquid was spray-coated on the vapor-deposited surface to obtain a hologram decorative resin molded article according to the present invention. Similar to Example 1, this resin molded product also had excellent three-dimensional visibility due to the hologram.

[Brief explanation of drawings]

1 to 4 are diagrams schematically showing the method of the present invention. 1; Mold 2; Hologram master plate 3; Molded product 4; Hologram unevenness 5; Reflective metal layer 6; Protective layer Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (7)

[Claims] (1) In a method for manufacturing a resin molded product using an injection molding method, a hologram master plate is provided on at least a part of the inner wall of the mold, injection molding is performed, and the hologram of the obtained resin molded product is reflected on the uneven surface. A method for producing a hologram decorative resin molded product, the method comprising forming a metallic layer. (2) The manufacturing method according to claim (1), wherein the hologram master plate is made of metal. (3) The manufacturing method according to claim (1), wherein the hologram master plate is made of a curable resin. (4) The manufacturing method according to claim (1), wherein a release agent is applied to the surface of the hologram master plate. (5) The manufacturing method according to claim (1), wherein the hologram master plate is planar. (6) The manufacturing method according to claim (1), wherein the hologram master plate has a curved shape. (7) The manufacturing method according to claim (1), in which a protective layer is provided on the reflective metal layer of the resin molded product.