JPS6328887A - Formation of pattern on molded body having reflective thin metallic film - Google Patents

Abstract

PURPOSE:To simply form a fine pattern on a transparent molded body in a short time by forming a thin metallic film and an org. colored finishing coat on one side of the molded body and by projecting infrared laser light having a specified wavelength on the molded body from the other side to remove part of the metallic film. CONSTITUTION:A reflective thin metallic film 9 of Al or the like is formed on one side of a transparent or translucent molded body 7 of plastics, glass or the like by vacuum deposition or other method after an underlayer 8 is formed with an org. undercoat as required. An org. colored finishing coat 10 of vinyl resin or the like is further formed on the film 9. An antireflection film 6 such as a PE film is formed on the other side and infrared laser light having 700-30,000nm wavelength is projected on the molded body 7 through the film 6 so that the light is converged on the film 9. The film 9 is patternwise removed by destruction, melting and evaporation, so the colored finishing coat 10 is seen as a desired pattern such as letters or a figure through the molded body 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for forming patterns such as letters on a reflective molded body, which is formed by forming a reflective thin film on one side of a transparent or translucent molded body. It is.

[Conventional technology]

A reflective metal thin film is formed on one side of a molded body such as a plate-shaped body of plastic or glass, and is used as a cosmetic mirror, etc., and simple letters or designs related to the product are printed on the corners of the mirror. It is often requested to display realistic figures, etc.

-] To apply a pattern such as etching-like letters to a reflective molded body of ilQ, as shown in Fig. 3, undercoat and undercoat one side of the molded body 1, such as a plastic plate, as necessary. A film 2 is formed, masking printing is performed on this to form a mask 3 of a pattern such as letters that is desired to appear, and then dry plating such as metal vapor deposition is performed over the entire surface to form a metal thin film 4. A masking method is known in which 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 a colored top coat 5.

In addition, there are also printing methods that print patterns such as 9 letters directly on the surface (mirror surface) on which the reflective thin film is not formed on reflective molded objects, and the use of chemicals such as hydrogen fluoride water to coat molded objects such as glass. Erosion methods are known in which the material is eroded to reveal a pattern.

[Problem that the invention seeks to solve]

However, in the case of the masking method, factors related to printing technology, such as ink stains, ink curing and drying time, and removability of masks, etc., greatly affect the quality of the finished mirror. If even a small amount of factors such as dirt, ink splatter, dust, printing errors, or printing defects that cause defects during printing enter into the mirror, it will no longer be a true mirror surface and will lose its essential value as a mirror. Become. This is an unavoidable problem as long as the printing process is involved. Also, printing drying.

Since processes such as peeling are also involved, there are drawbacks such as time consuming and high manufacturing costs.

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

Furthermore, in the case of the erosion method, special powerful chemicals such as hydrogen fluoride water are used, which requires great care in safety management, and the accuracy of the work is inherently poor, resulting in the formation of fine patterns. The drawback is that it takes a lot of effort and time to do so, and the manufacturing cost is also high.

[Means 2 for solving the problem] In view of the current situation, the present invention forms a thin metal film and an organic colored top coat on one side of a transparent or translucent molded body,
,000 NM infrared laser beam is focused on the metal thin film through the transparent or semi-transparent molded body from the other untreated surface and irradiated to the position where a pattern such as the character 9 figure is formed, and the metal thin film is removed in a pattern. The color of the organic topcoat film can be seen through a transparent or semi-transparent molded body (by doing so,
Characters in which the color of the organic colored topcoat appears to be floating.

The present invention will be described in detail below to provide a method for forming a pattern on a molded object having a reflective metal thin film, which enables fine patterns such as figures to be formed accurately, efficiently, and inexpensively. shall be.

The transparent or translucent molded product used in the present invention includes flat plate-like transparent or translucent plastic plates, glass plates, etc., as well as those having various shapes such as convex and concave surfaces, and plastic molded products. Examples include methacrylic resin and polycarbonate resin.

Vinyl chloride resin, AS (acrylonitrile-styrene copolymer) resin, PS (polystyrene resin).

A molded body made of polyester resin or various other resins that can be molded into transparent or translucent shapes is used.

A reflective thin film is formed on one side of a transparent or translucent molded product. When the molded product is a plastic molded product, the reflective thin film can be formed by vacuum evaporation, ion blating,
A metal thin film formed by dry plating (vapor phase plating) such as sputtering is desirable.

Next, to explain in detail the case of forming a metal thin film on a plastic molded body, first, oil, fat, dust, dirt, etc. are removed from one or both sides of the plastic molded body using a fluorinated solvent, and an organic undercoat is applied. to form an undercoat film. However, the surface of the plastic molded body is smooth and there is no adhesion of oils and fats, and it can be directly used as it is.
There is no need to apply an undercoat if dry plating provides a sufficient mirror surface or if the dry plating layer adheres closely to the plastic molded body. An undercoat may be applied, for example, when the plastic molded body is not smooth or when the dry plating layer does not adhere directly to the plastic molded body.

This organic undercoat is acrylic.

Paints made of resins selected from urethane-based, epoxy-based, vinyl-based, polyester-based resins, alkyd resins, etc., or modified resins thereof are suitable. Coating methods include spray coating, dipping coating, flow coating, etc., and considering aspects such as mirror surface quality, dipping coating, flow coating, etc. are preferable. In addition, the coating thickness is preferably about 5 to 20 μm (the coating can be cured using evaporation drying type, triple reaction curing type, ultraviolet curing type, etc. depending on the situation).Next, the above coating is applied. The applied plastic molded body is vacuum evaporated, ion blasted,
Dry plating such as sputtering is applied, and a top coat is applied to protect the thin metal film formed by this plating to form an organic colored top coat. Organic vinyl, urethane, acrylic, and epoxy systems are used to form this top coat.

Polyester paint etc. are used. In addition to pigments of colors that are intended to make the color of the top coat clearly visible in a pattern from the mirror side of the plastic molded body when the thin metal film is destroyed, melted, or evaporated by laser irradiation as described below. It is desirable to use a paint to which opaque pigments, extender pigments, etc. are added. The preferred coating method for forming the top coat is spray coating, and the coating must be thick enough to provide opacity and corrosion resistance. By drying and curing the top coat, each layer of the base coat, metal thin film, and top coat is formed on the plastic molded body, and a plastic mirror whose untreated surface has a mirror surface is obtained.

If the transparent or translucent molded body is a glass molded body, a metal thin film using a silver mirror reaction using a water-soluble silver compound such as silver nitrate and a reducing agent such as formalin or hydrazine is applied to one side of the glass molded body. Although it is desirable to form the plastic molded body and apply a top coat similar to that of the plastic molded body, the present invention is not limited thereto, and any suitable method can be used.

An infrared laser beam is irradiated from the untreated surface (mirror surface) of the transparent or translucent reflective molded product thus obtained. When the molded body is transparent, an antireflection film is laminated on the mirror surface of the reflective molded body before irradiation with an infrared laser beam, or is interposed in the optical path. The anti-reflection film is preferably a translucent film made of various resins such as polyethylene, saturated polyester, polyamide, polyvinyl alcohol, ethylene-vinyl acetate copolymer, hollybropylene, polyvinyl chloride, etc.
Any film that has an anti-reflection effect against infrared laser beams used within the wavelength range of M is acceptable (although it may be less transparent for visible light, resin films that appear nearly transparent may also be used).

The antireflection coating prevents the laser beam from being reflected by the reflective molded body and causing damage to equipment or injury to workers. When the molded body is translucent, the molded body itself has an antireflection function, so there is almost no need to use an antireflection film.

Irradiation with an infrared laser beam is carried out by appropriately setting the direction of the infrared laser beam with a wavelength of 700 to 30,000 nm generated from a laser generating part using a polarizing mirror, etc. The metal thin film at the position where the pattern such as the character 5 figure is formed is destroyed, melted, evaporated, etc. by focusing and irradiating it. Note that it is sufficient that the metal thin film is removed to such an extent that it can be distinguished from other parts with the naked eye. Various types of laser beams can be used, but YAG laser (wavelength 1
, 06ONM) and carbon dioxide laser (wavelength 10.60O
N? I) etc. are preferred.

By strictly focusing the infrared laser beam, for example, as shown in FIG. 1, the infrared laser beam can be transmitted through the antireflection film 6, the transparent molded body 7, and the undercoat film 8, and the metal thin film 9 can be evaporated. As shown in FIG. 2, the part of the metal thin film 9 is seen through in a pattern, and when viewed from above (the mirror side of the reflective plate) in FIG. appears to stand out in a fine pattern such as the character 9 figure.

〔Example〕

Example 1 Polymethyl methacrylate (PMMA) (
A transparent plate (thickness: 1 mm) made of methacrylic resin is coated with ultraviolet curing paint to a thickness of about 10 μm using the dipping method. After curing, a translucent polyethylene sheet of 0.1 mm thickness is coated on one side with scratches etc. The other side was coated with a thin aluminum film of about 700 to 10,000 layers in a vacuum of I x 10-' Torr by vacuum evaporation. Furthermore, an organic top coat of a paint having the following composition was applied to the aluminum evaporated surface to form a colored top coat in order to protect the aluminum thin film, prevent corrosion, and display the color of the etched pattern.

Polybutadiene resin 18 weight% Epoxy resin 2 Phenol resin 4 Structure Pigment, etc. 21% by weight Hydrocarbon solvent 55 The top coat is applied by spraying to a thickness of about 20 to 30μ, and Drying was performed at 70°C for 30 minutes.

The obtained reflective plate-like body was placed with the polyethylene film side facing up and the aluminum thin film side facing down, and was irradiated with an infrared laser beam generated from an Nd:YAG rod at an output of 10 to 20 W from above. The infrared laser beam was focused by a lens on the aluminum thin film of the reflective plate, so the laser beam transmitted through the polyethylene film and the transparent plate, destroying the aluminum thin film in minute patterns.
Melting.

Removed by evaporation etc. Depending on the degree of removal of this aluminum thin film, a portion of the organic top coat, which is a protective film, may be removed.
Although some parts were destroyed, the entire top coat was not removed, and when viewed from the polyethylene film side, the color of the top coat appeared to stand out in a fine pattern. The obtained mirror was pasted inside the compact of a cosmetic container, and finally the polyethylene film was peeled off to use it as a mirror of a compact for storing foundation, which is a cosmetic container.

Example 2 A reflective plate-like body was molded in the same manner as in Example 1 except that a semitransparent plate molded with PMMA was used, and the same infrared laser beam was irradiated without using an antireflection film. As a result, we obtained a mirror with a fine pattern that appears raised.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, by using an infrared laser beam, minute shapes such as letters and figures can be applied to a reflective plate-like body obtained from a transparent or semi-transparent molded body without staining its mirror surface. Patterns can be formed easily and in a short time, and when viewed from the non-treated side (mirror side) of the reflective molded object, the color of the top coating film stands out in a pattern due to the removal of the fine pattern of the metal thin film. In addition to being able to obtain a pattern that is highly visible and distinguishable, the topcoat film, which has been subjected to fine removal of the metal thin film, maintains the state immediately after processing and is reliably retained. It is possible to achieve the above excellent effects.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, and FIG. 1 is an explanatory diagram showing a state in which a reflective molded body is irradiated with a laser beam, FIG. 2 is an explanatory diagram showing a state after irradiating a laser beam, and FIG. FIG. 3 is an explanatory diagram showing a pattern forming method using a conventional masking method. 1: Molded body 2, 8: Undercoat film 3: Mask 4, 9: Metal thin film 5.10: Top coat film 6: Antireflection film 7: Transparent molded body Patent applicant Yoshino Kogyo Co., Ltd. Tsuda Kogyo Co., Ltd. ■ Figure 1 Figure 2 ＼ 'ni

Claims (1)

[Claims] A thin metal film and a colored organic top coat are formed on one side of a transparent or translucent molded body, and an infrared laser beam with a wavelength of 700 to 30,000 nm is applied to the transparent or semitransparent molded body from the other untreated side to form the metal thin film. The metal thin film is removed in a pattern, and the color of the organic colored topcoat is applied from the untreated surface through the transparent or translucent molded body. 1. A method for forming a pattern on a molded body having a reflective metal thin film, which is characterized in that the pattern is made visible.