JPH07116625B2 - Method for forming pattern on molded body having reflective metal thin film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a pattern such as characters on a reflective molded product formed by forming a reflective thin film on one surface of a transparent or translucent molded product. Is.

[Conventional technology]

It is used as a mirror for makeup etc. by forming a reflective metal thin film on one surface of a molded body such as a plate-shaped body such as plastic, glass, etc. Simple characters and designs related to the product in the corners of this mirror etc. In many cases, it is desired to display a graphic.

Generally, in order to give an etching-like pattern to the reflective molded body, an undercoat is applied to one surface of the molded body 1 such as a plastic plate as required to form the lower coating film 2 as shown in FIG. Then, masking printing is performed on this to form a mask 3 of a pattern such as a character to be exposed, and then dry plating such as metal deposition is performed on the entire surface to form a metal thin film 4.
There is known a masking method in which after the formation, the mask 3 is peeled off to reveal a pattern, and a colored top coat or the like is applied to the entire surface to form the colored top coating film 5.

In addition, a printing method for printing patterns such as letters directly on the surface (mirror surface) on which the reflective thin film of the reflective molded product is not formed, or a chemical such as hydrogen fluoride water is used to mold the molded product such as glass. An erosion method of eroding a pattern is known.

[Problems to be solved by the invention]

However, in the case of the masking method, factors related to printing technology, such as ink stains, ink curing and drying time, and mask releasability, will greatly affect the finish of the mirror as a finished product. If a few factors such as stains, ink splashes, dust, printing mistakes, printing defects, etc., which are defective factors at the time of printing, are no longer a true mirror surface, the intrinsic value as a mirror is lost. Become. This is a problem that cannot be avoided because the process of printing is included. Further, since steps such as drying and peeling of printing are included, there is a drawback that it takes time and the manufacturing cost becomes high.

Next, in the case of the printing method, in addition to the same drawbacks caused by the printing step in the masking method, there were serious drawbacks such as ink stains even during use.

Furthermore, in the case of the erosion method, special powerful chemicals such as hydrogen fluoride water are used, so great care must be taken in safety management and the work precision is essentially poor, so a fine pattern is formed. However, this requires a lot of labor and time, and has a drawback that the manufacturing cost becomes high.

[Means and actions for solving problems]

In view of the present situation, the present invention forms a metal thin film and an organic colored top coating film on one surface of a transparent or translucent molded article, and transmits an infrared laser beam having a wavelength of 700 to 30,000 NM from other non-treated surfaces. Or, the metal thin film is focused through a semi-transparent molding and irradiated to the position where a pattern such as letters and figures is formed, the metal thin film is removed in a pattern, and the color of the organic top coating is transparent or semi-transparent. Reflective metal thin film that makes it possible to accurately and efficiently form a fine pattern such as letters and figures by making it visible through the molded article of The present invention will be described in detail below by providing a method for forming a pattern on a molded article having

The transparent or translucent molded product used in the present invention is not only a transparent or translucent plastic plate, a flat plate such as a glass plate, but also various shapes such as a convex surface and a concave surface. Examples of the molded product include methacrylic resin, polycarbonate resin, vinyl chloride resin, AS (acrylonitrile-styrene copolymer) resin, PS (polystyrene resin, polyester resin, and other various transparent or semi-transparent moldable resins. Is used.

A reflective thin film is formed on one surface of a transparent or translucent molded product. As the reflective thin film, when the molded product is a plastic molded product, vacuum deposition, ion plating,
A metal thin film formed by dry plating (vapor plating) such as sputtering is desirable.

Next, a detailed description will be given of the case of forming a metal thin film on a plastic molded body. First, one side or both sides of the plastic molded body are removed with a fluorine-based solvent to remove oils, dust, dust, etc., and an organic undercoat is applied. Apply to form a bottom coating. However, the surface of the plastic molded body is smooth, there is no adhesion of oils and fats, and in that state directly,
It is not necessary to apply an undercoat when the dry plating gives a sufficiently mirror-finished surface or when the dry plating layer adheres to the plastic molding. The undercoat is applied, for example, when the plastic molded body is not smooth or when the dry plating layer is difficult to directly adhere to the plastic molded body. This organic undercoat includes acrylic, urethane, epoxy, vinyl,
Resins selected from polyester resins, alkyd resins and the like, or coatings composed of these modified resins are suitable. The coating methods are spray coating, dip coating,
There are flow coater coating, etc. Considering the quality such as mirror surface, dip coating and flow coater coating are preferable. The coating thickness is preferably about 5 to 20 .mu.m, and the coating curing form may be an evaporation drying type, a reaction curing type, an ultraviolet curing type or the like depending on the situation. Next, dry coating such as vacuum deposition, ion plating, and sputtering is applied to the plastic molded product with the above-mentioned coating, and a top coat is applied to protect the metal thin film due to this plating etc. Form a top coating. Organic vinyl-based, urethane-based, acrylic-based, epoxy-based, polyester-based paints, etc. are used to form the top coating film. The metal thin film is destroyed by the laser irradiation described later,
When melting or evaporating, an opaque pigment or an extender pigment is added in addition to the pigment whose color is intended to appear so that the color of the top coating film can be seen clearly from the mirror surface side of the plastic molded body. It is desirable to use a different paint. As a coating method for forming the upper coating film, spray coating is desirable, and the coating thickness must be sufficient to provide opacity and corrosion resistance. By drying and curing the upper coating film, each layer of the lower coating film, the metal thin film and the upper coating film is formed on the plastic molded body, and a plastic mirror having a non-treated surface as a mirror surface is obtained.

When the transparent or translucent molded body is a glass molded body, a metal thin film utilizing a silver mirror reaction using a water-soluble silver compound such as silver nitrate and a reducing agent such as formalin or hydrazine is formed on one surface of the glass molded body. It is desirable to form and apply a top coat similar to that of the plastic molded body, but the present invention is not limited to this and an appropriate method can be used.

An infrared laser beam is irradiated from the non-treated surface (mirror surface) of the reflective molded body made of the transparent or translucent molded body thus obtained. When the molded product is transparent, an antireflection film is preliminarily laminated on the mirror surface of the reflective molded product or interposed in the optical path before the irradiation with the infrared laser beam. As the antireflection film, polyethylene, saturated polyester, polyamide, polyvinyl alcohol, ethylene-vinyl acetate copolymer,
A translucent film made of various resins such as polypropylene and polyvinyl chloride is desirable, but it is sufficient if it has an antireflection effect on an infrared laser beam used in a wavelength range of 700 to 30,000 NM, and a visible lightゝ Although the transparency is inferior, a resin film that looks almost transparent may be usable. The antireflection film prevents the laser beam from being reflected by the reflective molding and causing damage to the equipment and injury to the operator. When the molded body is translucent, the use of an antireflection film is almost unnecessary because the molded body itself has an antireflection function.

Irradiation of the infrared laser beam is performed by appropriately setting the direction of the infrared laser beam having a wavelength of 700 to 30,000 NM generated from the laser generation part using a polarizing mirror or the like, but with a lens on the metal thin film of the reflective molded body. Irradiation is performed by focusing and destroying, melting, or vaporizing the metal thin film at the position where a pattern such as a character or a figure is formed. It should be noted that the degree of removal of the metal thin film is sufficient as long as it can be discriminated from other places with the naked eye. Various laser beams can be used as the laser beam to be used, but a YAG laser (wavelength 1,060 NM), a carbon dioxide laser (wavelength 10,600 NM) and the like are preferable.

By rigorously focusing the infrared laser beam, for example, as shown in FIG. 1, the antireflection film 6, the transparent molded body 7 and the lower coating film 8 can be transmitted to evaporate the metal thin film 9. As shown in FIG. 2, the portion of the metal thin film 9 can be seen through in a pattern, and the lower coating film when viewed from above (the mirror surface side of the reflective plate-like body) in FIG.
The 10 colors will appear as fine patterns such as letters and figures.

〔Example〕

Example 1 Polymethylmethacrylate (PMMA) [methacrylic resin]
The transparent plate (thickness 1mm) molded with is coated with a UV-curable coating by an immersion method to a film thickness of about 10μ, and after curing, a semi-transparent polyethylene sheet with a thickness of 0.1mm is protected from scratches and red on one side. It was coated for the purpose of preventing reflection of an external laser beam, and an aluminum thin film was adhered to the other surface by vacuum evaporation in a vacuum of 1 × 10 ⁻⁴ Torr to about 700 to 10,000 Å. Further, an organic top coat of a paint having the following composition was applied on the aluminum vapor-deposited surface to protect the aluminum thin film, prevent corrosion, and reveal the color of an etching pattern to form a colored top coating film.

Polybutadiene-based resin 18% by weight Epoxy-based resin 2 〃 Phenol-based resin 4 〃 Extender pigment, etc. 21 〃 Hydrocarbon solvent 55 〃 The top coating is sprayed to a thickness of 20 to 30μ, and 60 to 70 ℃ 30 Minutes of drying were performed. The obtained reflective plate was irradiated with an infrared laser beam generated from a Nd: YAG rod at an output of 10 to 20 W from above with the polyethylene film side up and the aluminum thin film side down. Since the focusing of the infrared laser beam by the lens was at the position of the aluminum thin film of the reflective plate, the laser beam was transmitted through the polyethylene film and the transparent plate and the aluminum thin film was broken into fine patterns, removed by melting, evaporation, etc. did. Depending on the degree of removal of this aluminum thin film, some of the organic top coating film that was the protective film was removed and destroyed, but not all of the top coating film was removed. In this case, the color of the upper coating film seemed to float up in a fine pattern. The obtained mirror was attached to the compact of a cosmetic container, and finally the polyethylene film was peeled off to use as a compact mirror for putting a foundation which is a cosmetic container.

Example 2 The reflective plate in Example 1 was molded in the same manner except that a semi-transparent plate molded with PMMA was used, and the same infrared laser beam was irradiated without using an antireflection film to obtain fine particles. I saw a mirror with a floating pattern.

〔The invention's effect〕

As is clear from the above description, according to the present invention, by using an infrared laser beam, a reflective plate-like body obtained from a transparent or semi-transparent molding can be used to form fine characters such as characters and figures without soiling the mirror surface thereof. The pattern can be formed easily and in a short time, and the non-treated surface side (mirror surface side) of the reflective molding
As seen from the above, the removal of the fine pattern of the metal thin film makes the color of the upper coating film appear to float up in a pattern, and a pattern with rich distinctiveness can be obtained, and the state of fine removal of the metal thin film is applied in advance. It is possible to achieve excellent operational effects in practical use, such as maintaining the state immediately after processing by the upper coating film and surely maintaining it.

[Brief description of drawings]

The drawings show an example of the embodiment of the present invention, FIG. 1 is an explanatory view showing a state where a reflective molded body is irradiated with a laser beam, and FIG. 2 is an explanatory view showing a state after irradiation with a laser beam, FIG. 3 is an explanatory view showing a conventional pattern forming method by a masking method. 1: Molded body, 2, 8: Bottom coating 3: Mask, 4, 9: Metal thin film 5, 10: Top coating, 6: Antireflection coating 7: Transparent molding

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Shimada 35 Tsuda Kogyo Co., Ltd. 25, capital 25, Namerikawa-cho, Hiki-gun, Saitama Prefecture (72) Inventor Haruo Okado 25th capital, Namekawa-cho, Hiki-gun, Saitama Prefecture 35 Tsuda Industry Co., Ltd.

Claims (1)

[Claims] 1. A transparent or semi-transparent molded article having a metal thin film and an organic colored top coating formed on one surface thereof, and an infrared laser beam having a wavelength of 700 to 30,000 NM is transparent or semi-transparent from other non-treated surfaces. The metal thin film is focused through the body to irradiate the position where a pattern such as letters and figures is formed, the metal thin film is removed in a pattern, and the color of the organic colored top coating film is transparent or semi-transparent from the untreated surface. A method for forming a pattern on a molded article having a reflective metal thin film, which is visible through the molded article.