JP2005143943A - Processing method of corrosion resistant mirror - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a corrosion resistant mirror that is provided with a corrosion resistant structure of one-layer configuration with sufficient anticorrosion property not only against water but also against corrosive gas at a low cost. <P>SOLUTION: A processing method of the corrosion resistant mirror, manufactured from a material mirror obtained by cutting a large mirror with a laminate film composed of a reflection coating layer that reflects light and a protection coating layer that covers the reflection coating layer on the back side into a prescribed size has a film removing process that makes a film removed section with a prescribed width by mechanically removing the laminate film on the peripheral edge of the back side of the material mirror with a removing tool, and a coat processing process where an anticorrosive coating of one-layer configuration is applied over the entire back side of the mirror including the film removed section. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mirror processing method, and particularly has high corrosion resistance suitable for a corrosion resistant mirror installed in a hot spring area under corrosive atmosphere such as a volcanic gas such as a bathroom using water. This invention relates to a mirror processing method.

As shown in FIG. 1, the mirror is a metal composed of a silver thin film that becomes a light reflecting film by chemical plating or the like on a back surface of a transparent plate material such as glass 1 and a copper thin film formed thereon to protect the silver thin film. A laminated film structure is formed by laminating a film 2 and a resin film (backing coating film) formed thereon with a resin coating called a back coating material as a protective coating film 3. Usually, after cutting a large size large-sized mirror having the above-mentioned laminated film into a predetermined size, the end face (small edge) is subjected to end face processing such as polishing or chamfering as a handling or assembling process. (Hereinafter, this small mirror is referred to as a “small mirror” for a large-sized mirror).

  However, since the end face of the split mirror is exposed to the end face of these end faces, the metal film 3 of the laminated film is exposed to moisture or a trace amount of harmful gas in the atmosphere. Will be corroded and the function as a reflective film will be lost. Therefore, in order to prevent this, as shown in FIG. 11, a synthetic resin such as an epoxy resin is applied to the peripheral portion including the end face of the mirror, and an edge coating film 25 (edge coating) which is a resin film having corrosion resistance. So-called edge coating was performed.

  In this case, in order to provide corrosion resistance, it is necessary to make the edge coating film 25 responsible for corrosion resistance in the vicinity of the exposed portion of the metal film 3 on the end face to be a certain thickness or more. Compared to other parts, the thickness of the coating film applied to the fore edge is compared to other parts because it is located near the edge of the edge of the small mirror that is thin compared to the plate thickness and has a substantially right cross-sectional shape. And easily thin. In order to prevent this, it may be possible to paint several times, but this leads to an increase in cost. Therefore, the edge coating used is generally prepared such that the viscosity is increased and the film thickness is increased even after coating. However, on the other hand, when such a high-viscosity paint is used, it is difficult to form a coating film with a uniform thickness over the entire circumference of the edge of the edge of the split mirror. Therefore, in order to secure the minimum film thickness necessary for exhibiting corrosion resistance while taking these points into consideration, it is necessary to form a thick film as a whole. The end face has a thick plate thickness, and when this is incorporated into a product, the degree of freedom in design is limited, making it unusable. In addition, since the mirror plate thickness is originally as thin as several millimeters, there is a problem in that the area of the glass portion with which the edge coating film 25 contacts is small and the adhesion strength is not so high.

  Therefore, as one of the countermeasures, after increasing the area of the glass portion of the end face edge by making the peripheral edge of the back surface of the material mirror a gentle inclined surface by grinding, the above-mentioned anticorrosive property is applied to the peripheral edge including the entire gently inclined surface. There has been proposed a method of forming a mirror by applying an edge coating (see, for example, FIG. 1 of Patent Document 1). In this case, since the angle of the edge line of the end face edge on the mirror back surface side where the metal film exposed part is relatively gentle, the film thickness near the edge line is formed thicker than the case where the end face edge is substantially perpendicular. In addition, the workability of the coating is improved, and the area of the glass portion that comes into contact with the edge coating is also increased, so that the adhesion of the coating film is also improved.

  On the other hand, in recent years, mirrors that have further improved corrosion resistance, mirrors with high corrosion resistance that can be installed in hot water areas such as bathrooms and in corrosive atmospheres such as volcanic gases. In other words, the use of the anticorrosion mirror referred to in the present invention is increasing. In that case, in the configuration in which the anticorrosion film is formed by edge coating only on the peripheral part as described above, and the other part of the back surface is left as the protective coating film (backing coating film), the protective coating film It was found that the required quality was not satisfied due to insufficient anticorrosive properties of the (backing coating film). Therefore, it is necessary to form a corrosion-resistant film on the entire back surface of the mirror other than the peripheral portion, and the entire surface of the back surface of the mirror including the peripheral portion is coated with the edge coating paint. (For example, refer to FIG. 2 of Patent Document 1) The edge coating material used in this case is adjusted to have a high viscosity in order to ensure the required film thickness at the edge line of the edge edge as described above. In other words, the film other than the peripheral part becomes thicker than necessary, and the mirror as a whole may have excessive quality.

  As another method, there is a method having the configuration shown in FIG. As described above, the peripheral portion including the metal film 22 exposed on the end surface which is the gently inclined surface 24 is covered with an anticorrosive edge coating film 25 (so-called edge coat) formed of a high viscosity edge coating. After that, the entire back surface is coated with another anticorrosive paint having a low viscosity, and two types of anticorrosive films are formed, which are covered with an anticorrosive film called a so-called backing film 26 (overcoat). In this case, the quality of the anti-corrosion mirror such as anti-corrosion is sufficient, but the production process of the anti-corrosion film is two steps, which increases the cost.

Japanese Utility Model Publication No. 55-157207 microtext

  The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a single-layer corrosion-resistant film that is low in cost and has sufficient corrosion resistance against not only moisture but also corrosive gas. It is to provide a method of manufacturing a corrosion-resistant mirror having a structure.

In order to achieve the above-mentioned object, the invention according to claim 1 is to cut a large-sized mirror having a laminated film composed of a reflective film layer that reflects light and a protective film layer covering the light into a predetermined size. In the processing method of the anti-corrosion mirror created from the material mirror to be obtained, a film removal processing step of creating a film removal portion having a predetermined width by mechanically removing the laminated film on the peripheral portion of the back surface of the material mirror with a removal tool And a film processing step of applying a single-layered anticorrosive film to the entire back surface of the mirror including the film removal portion.
As a result, the shape in the vicinity of the exposed cross section of the metal layer portion is only the thickness of the thin metal film portion, so that the anticorrosion film having the corrosion resistance necessary for the one-time anticorrosion coating on the entire back surface with a relatively low viscosity paint. The manufacturing cost of the anticorrosion mirror becomes low.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the film removal processing step is a step of performing grinding using a grindstone as a removal tool.
As a result, the chamfering process is the same as the chamfering process of the end face that is used when creating a final mirror by splitting from a large-sized mirror. Since film removal processing can be performed, the efficiency of processing work can be improved.

The invention according to claim 3 is the invention according to claim 1 or 2, characterized in that the anticorrosion film is a thermosetting acrylic resin paint. This paint is a one-component paint that is easy to manage in the film processing process, and is less expensive than commonly used epoxy paints, so the manufacturing cost of the anticorrosion mirror can be reduced.

The invention according to claim 4 is the invention according to claim 1 or 2, characterized in that the anticorrosion film is an epoxy-modified silicone resin paint.
Thereby, since the durability of the corrosion-resistant film is improved, the corrosion-resistant performance of the manufactured corrosion-resistant mirror is improved.

  According to the present invention, there is an effect that a high-quality anticorrosion mirror can be manufactured inexpensively and efficiently using a large-sized mirror as a material.

Preferred embodiments of the invention are described below.

  A large-sized mirror manufactured by a normal method is made into a small-sized mirror with a size close to the final finish by scribing and dividing it into a predetermined shape with a carbide tool. As shown in FIG. 1, this large format mirror has a thin film of silver on a glass 2 as a reflection film, and a metal film 3 on which a copper thin film for protecting the reflection film is stacked, and further thereon. It has a laminated film structure in which a protective coating film 3 which is a coating film of a synthetic resin paint, which is usually called a backing coating film, is stacked, and the small mirror has the same structure as a matter of course.

In this embodiment, the case where the completed shape is a rectangular mirror will be described as an example.
The subdivided split mirror performs end face (small edge) processing in preparation for carrying out the present invention. FIG. 2 schematically shows the construction of a production line that continuously performs this processing and the film removal processing described later, which is composed of a plurality of processing stages and can perform the above processing continuously. It is configured as follows. FIG. 3 schematically shows the processing contents at each processing stage.

  A workpiece conveyor belt that transports and fixes the workpiece during processing with one side of the material mirror 1 parallel to the workpiece table 7 and protruding 5 to 20 mm on a highly rigid workpiece table 7 set. In addition, as a fixing method, the method of fixing each workpiece | work to the separate jig | tool with the fixing pad by an air cylinder may be used.

  First, in process 1, the end face is polished to make the outer shape the final dimension. Next, necessary chamfering is performed on the end surface by processing 2. The small edge ridgeline on the back side (anti-user side) of the mirror performs small chamfering necessary for handling, and the mirror surface side (user side) has a gentle chamfering of a gentle slope according to the design requirements of the appearance. To do. In this case, the decorative chamfering is further subjected to finish polishing and buffing in processes 3 and 4 to adjust the appearance to obtain a mirror having a cross-sectional shape shown in FIG. The process up to this point has been performed conventionally and has no special features. In the present embodiment, the mirror shown in FIG. 6 is hereinafter referred to as a material mirror 1 for carrying out the invention.

Next, a film removal process for completely removing a predetermined range of the laminated film on the back surface of the material mirror 1 is performed at the stage of process 5. FIG. 4 schematically shows the stage of this processing 5, and FIG. 5 shows the setting state of the workpiece (material mirror 1) and the processing machine (grinding stone 7, mounting base 8). Thus, below the material mirror 1, it moves parallel to the mounting base 8 and is 60 μm above the upper surface of the mounting base 8.
There is a grindstone 7 set so that the cutting edge comes to a high state and has a rotation axis perpendicular to the mounting base 8 and parallel to the processing surface of the material mirror 1. While this grindstone 7 is rotated, the grindstone 7 is moved parallel to the coating surface of the mirror, and the coating film on the peripheral portion of the material mirror 1 is deleted. At this time, the point is to remove all of the laminated film including the silver layer with a width of about several mm from the mirror end face. Therefore, at the same time, the glass surface of the material mirror 1 may be deleted together by a slight amount. .
This operation is performed on the remaining three sides of the material mirror 1 to obtain the material mirror 1 having the cross-sectional shape of FIG.

In addition, regarding the detailed processing methods such as the grindstone shape and workpiece setting method in the end face processing and film removal processing, various modified examples can be adopted within the range of conventional techniques of grinding processing that are usually performed, and examples thereof are given. For example, the grindstone shaft position may be fixed and only the material mirror 1 may be moved in parallel.
Further, the film removal process is not a grinding process using a grindstone, and only the laminated film may be scraped off with, for example, a claw-shaped blade. Other processing methods are also included in the scope of the present invention as long as at least the laminated film can be completely removed and processed within a step substantially equal to the thickness of the laminated film.

After washing and drying this mirror, a colorless thermosetting acrylic paint with a non-volatile content of about 50% and a viscosity adjusted to 30 ± 5 seconds with a Ford cup (eg Cashew Co., Ltd.) Ltd. Akuriesu (TM) and # 300) using a curtain flow coater coating while wet as film thickness of at least 50μm is obtained at a rate of 100g ^{/ m 2} ~250g ^/ m 2 after drying, the solvent In order to prevent foaming due to rapid evaporation, the mixture is left for 5 to 10 minutes and then dried at 150 ° C. for 20 minutes. As a result, the coating film is also laminated in the vicinity of the exposed metal layer at the edge of the mirror of the material mirror, and has a thickness of 80 to 100 μm in combination with the thickness of the backing coating. A coating film that can be sufficiently protected was formed.

FIG. 8 is a schematic view of the completed mirror as a whole, and FIG. 9 is an enlarged view of the end surface A portion.
For comparison, FIG. 10 schematically shows the coating state when the paint of the same condition used in this example is applied to a conventional material mirror having a gentle end face. .

Thus, when applied to a conventional material mirror having a gently sloping surface under the same conditions as in the present embodiment where the film thickness of the back surface portion is set to be close to the necessary minimum, the back surface portion is as shown in part B of FIG. The film thickness in the vicinity of the exposed portion of the metal layer was thinner due to the relatively low viscosity of the paint, and the required film thickness could not be obtained.
On the other hand, in the present invention, since the step of the exposed portion of the metal layer is only about the thickness of a large-sized laminated film (usually about several tens of μm to about 100 μm), the above-described thermosetting prepared with a relatively low viscosity. Even with acrylic paint, the film thickness in the vicinity of the exposed portion of the small metal layer was not much different from the thickness of the coating on the back surface. Therefore, the amount of paint used can be smaller than that of the conventional method, and the manufacturing cost can be reduced.
Furthermore, there is an advantageous feature in the design that the width of the contact surface with the glass can be appropriately set regardless of the plate thickness in accordance with the paint to be used.

In addition, in order to improve the adhesiveness with the glass part exposed by grinding in a coating material, it is still better to add a silane coupling agent.
In addition, an epoxy-modified silicone resin paint may be used as the paint, and in that case, the durability as a corrosion-resistant mirror is further improved.

It is an expanded sectional view which shows the structure of the large format mirror used as the material mirror in this invention. It is a figure which shows an example of the manufacturing line which performs the grinding process of the chamfering process of this invention, and a film | membrane removal processing process. It is a figure which shows the grindstone used by the grinding process of the film | membrane removal process of this invention. It is a perspective view which shows typically the state of the grinding process of the film | membrane removal process of this invention. FIG. 5 is a side view of FIG. 4. It is an expanded sectional view which shows the structure of the raw material mirror which cut | disconnected the large size mirror to the desired magnitude | size and performed the chamfering process of the required end surface for using by this invention. It is sectional drawing of the raw material mirror which finished the film removal process of this invention. It is sectional drawing of the anti-corrosion mirror obtained by this invention which completed the film processing process of this invention. It is an expanded sectional view of the peripheral part A part of the corrosion-proof mirror of FIG. It is an expanded sectional view which shows the state of the mirror peripheral part of the anticorrosion film | membrane formed when the film processing process of this invention is applied to the raw material mirror of the shape surface-finished by the conventional method. It is an expanded sectional view which shows the structure of the peripheral part of the corrosion-resistant mirror produced by the conventional method. It is an expanded sectional view which shows the structure of the peripheral part of the corrosion-resistant mirror produced with the other conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Material mirror 2 ... Glass 3 ... Metal film 4 ... Protective coating 5 ... Chamfering 6 ... Make-up chamfering 7 ... Grinding stone 8 ... Processing stand 10 ... Film removal part 11 ... Corrosion-resistant film 21 ... Glass 22 ... Metal film 23 ... Protective coating 24 ... Slightly inclined surface 25 ... Edge coating 26 ... Backing coating

Claims (4)

In the method for processing a corrosion-resistant mirror, a large-sized mirror having a laminated film composed of a reflective film layer that reflects light and a protective film layer covering the back surface is prepared from a material mirror obtained by cutting into a predetermined size. A film removal processing step of creating a film removal portion having a predetermined width by mechanically removing the laminated film on the peripheral portion of the back surface of the material mirror with a removal tool, and one layer on the entire back surface of the mirror including the film removal portion And a coating processing step for applying a corrosion protection coating having a structure. The mirror processing method according to claim 1, wherein the film removal processing step is a step of performing grinding using a grindstone as a removal tool. The mirror processing method according to claim 1, wherein the anticorrosive film is a thermosetting acrylic resin paint. The mirror processing method according to claim 1, wherein the anticorrosive film is an epoxy-modified silicone resin paint.

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