JPH11128041A - Corrosion resistant mirror and its producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain edge corrosion resistance performance being more excellent than a conventional mirror. SOLUTION: A reflection metallic layer 3 is formed on the back surface of a glass plate 2 by laminating a back coating film 4 on it in a mirror 1. In the mirror 4, an inclining surface 5 obtained by diagonally cutting from the back surface peripheral part of the glass plate 2 to an end surface is formed, the inclination angle of the inclining surface as against the back surface is made to be within the range of 5-15 deg., an edge coating film 6 is formed from a back coating film 4 peripheral part to the inclining surface 5 in order to cover the reflection metallic layer 3 which is exposed in the inclination surface 5, the thickness of the edge coating film Y on the exposed reflection metallic layer is made to be more than 60 μm and that of the max. film thick part X in the edge coating film 6 is made to be equal to below 170 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror in which a backing coating is applied on a reflective metal layer on one side of a glass plate, and a corrosion-resistant coating in which an edge coating is applied to an inclined surface of the peripheral portion of the back surface. About the mirror.

[0002]

2. Description of the Related Art When a mirror is not coated with an edge coating film, even in a normal environment, the exposed portion of the reflective metal layer on the end face of the mirror is exposed to water vapor, other acidic gas, etc. from the atmosphere. Harmful components cause corrosion, resulting in so-called marbling. In order to prevent this, it is essential to apply an edge coating film.

However, in particular, liquids containing chemicals such as acidic or alkaline tile detergents may adhere to mirrors mounted on the walls of bathrooms and hot spring baths. Other harmful components attack the metal layer through the rim coating.

Japanese Patent Application Laid-Open No. 49-11 / 1999 filed by the applicant of the present invention
No. 5115 discloses an anti-corrosion mirror in which a glass plate is plated with silver, and a protective layer is further provided on the mirror, the periphery of the rear surface of the mirror is obliquely cut, and a corrosion-resistant synthetic resin film (film) is thermally welded over the oblique cross section and the rear surface of the mirror. And that the inclination angle with respect to the mirror back surface is 15 ° and the thickness of the corrosion-resistant synthetic resin film is 20 μm.

Further, Japanese Patent Application Laid-Open No.
In No. 48-95849, a silane coupling agent coating layer is applied to the oblique cross section of the mirror back surface edge of which is less than 30 ° to the mirror surface so that the silver film is exposed, and a corrosion-resistant synthetic resin coating is applied over the coating layer and the mirror back surface. Disclose the formed corrosion-resistant mirror, the inclination angle with respect to the mirror back surface is 15 °, the film thickness of the corrosion-resistant synthetic resin coating is 73μ
m (Applicant's note: In this case, it indicates the maximum coating thickness including the backing coating portion, and the thickness from the exposed portion of the silver film is 50 μm or less). However, in recent years, there has been an increasing demand from users for further improving the corrosion resistance of mirrors, and conventional edge coating techniques have been unsatisfactory.

The present invention has been made in view of the above-mentioned disadvantages of the prior art, and provides an anti-corrosion mirror having improved rim resistance.

[0007]

According to the present invention, there is provided a mirror having a reflective metal layer formed on the back surface of a glass plate and a backing coating formed thereon, wherein the inclined surface is obliquely cut from the periphery of the back surface of the glass plate to the end surface. The inclination angle of the inclined surface with respect to the back surface (hereinafter referred to as a back surface chamfer angle) is in the range of 5 to 15 °, and in order to cover the reflective metal layer exposed on the inclined surface, An edge coating film is formed over the inclined surface, and the thickness of the edge coating film Y on the exposed reflective metal layer is set to 60
μm or more, except that the maximum thickness X of the edge coating film is 170
This is a corrosion-resistant mirror with a size of μm or less.

Further, it is preferable that the inclination angle of the inclined surface is 7 to 13 °, and that the thickness of the edge coating film Y is 80 μm or more.

The present invention also relates to a method of manufacturing a mirror having a reflective metal layer formed on the back surface of a glass plate and a backing coating layer formed thereon, wherein the inclined surface inclined from the peripheral portion of the back surface of the glass plate to the end surface is wet-processed. It is formed by polishing, the inclination angle of the inclined surface with respect to the back surface is in the range of 5 to 15 °, and in order to cover the reflective metal layer exposed on the inclined surface, edge coating is performed from the periphery of the backing coating film to the inclined surface. The film is formed by a coating roller and cured to form a coating in which the thickness of the rim coating Y on the exposed reflective metal layer is 60 μm or more and the thickness of the maximum thickness portion X of the rim coating is 170 μm or less. This is a method for manufacturing a corrosion-resistant mirror for forming a film.

[0010]

FIG. 1 is a partial cross-sectional view of a mirror (corrosion-resistant mirror) 1. As a glass plate 2, an alkali / magnesium lime / silicate glass including soda-lime glass Glass of various composition such as aluminosilicate glass, borosilicate glass, etc. is applied, and the thickness varies from about 1 mm to about several tens of mm, but the mirror installed in the room, bathroom (bathroom) is 5 mm There are many things before and after.

On the back side of the glass plate 2, ie, the mirror 1, a reflective metal film (silver + copper in the drawing) 3 which is usually made of a silver film and a copper film for protecting the silver film is applied, and has a thickness of 100 nm.
Before and after. The reflective metal film 3 can be made of aluminum, lead, other metals, or a composite metal thereof in addition to silver in order to bring about a reflected image. In some cases, the protective metal film is not applied to a so-called low-grade mirror. In order to suppress the corrosion of the metal film such as silver, the metal film is applied on the metal film such as silver. In addition to copper, chromium, nickel, other metals, and composite metals thereof can be used.

The back coating film 4 is a coating film provided on the reflective metal film in order to suppress corrosion of the reflective metal film 3 from the back side of the mirror, and includes an alkyd resin, an epoxy resin, a urethane resin and the like. A coating film made of a paint in which various corrosion resistant resins are mixed with iron oxide, zinc oxide, lead compounds and other corrosion resistant pigments, and various fillers is provided.

The peripheral edge of the rear surface of the mirror 1 is cut and polished from the rear surface to the end surface and cut obliquely to form an inclined surface 5. The main purpose of the oblique cutting is to reflect the reflective metal film 3a exposed on the mirror end face.
This is for facilitating the coating operation when the protective coating is performed.

An inclination angle of the inclined surface 5 with respect to the mirror back surface,
In other words, the backside angle α is different for each mirror and mirror processing company.
Taking into account the ease of chamfering, etc., we have set the angle to about 20 °. As the rim coating paint, urethane-based, polyester-urethane-based, polyether-urethane-based, epoxy-based, epoxy-urethane-based, and the like can be used. As a rim coating means, coating with a coating roller is generally used, but not limited to this. After the edge coating, a coating film is formed by drying by heating at 150 ° C or less or by natural drying.

The edge coating is performed with a width of several mm to 10 mm or less from the peripheral portion of the backing coating 4 to the inclined surface 5.
The edge coating film 6 has a maximum film thickness at a position X (hereinafter referred to as a maximum portion) on the backing coating film as shown in the figure. Conventionally, the "film thickness" refers to the film thickness of the maximum portion X, but the film thickness of the rim coating film Y (hereinafter referred to as an important part) on the reflective metal layer 3a exposed on the inclined surface described above. Is the liver and kidney. In other words, the resin cured film is not limited to the backing coating,
Although thinner, the thinner the film, the greater the air permeability, and water vapor and harmful gases affect the reflective metal film through the coating film, causing edge fringing. The thickness of Y should be at least 60 μm or more, more preferably 80 μm or more. On the other hand, when the film thickness of the maximum portion X is unnecessarily thick, when the solvent in the paint is volatilized at the time of curing after edge coating, bubbles remain or broken bubbles are generated on the surface of the paint film,
Since the water vapor and harmful gas enter from this portion, which easily affects the reflective metal film and also impairs the appearance, the thickness is set to 170 μm or less.

In order to obtain the above-mentioned film thickness range, when the back surface chamfering angle α is set to 20 °, the film thickness of the crucial part Y is less than 40% of the film thickness of the maximum part X according to the application by the coating roller. It can be seen that the essential part Y of the liver is not effectively applied. On the other hand, for example, when the back chamfering angle is set to 10 °, the thickness of the important part Y with respect to the maximum part X reaches about 90%, and a good film can be formed.

Further, in the case of the above-mentioned back chamfering angle of 20 °, for example, in order to obtain a film thickness of about 100 μm of the important part Y, the film thickness of the maximum part X needs to be 300 μm or more. When the solvent in the paint evaporates during the curing of the paint, bubbles remain, or the paint film surface breaks, causing water vapor and harmful gas to enter from this part, It tends to affect the film and hinders its appearance.

That is, the back surface angle α is 5 ° to 15 °.
When the angle exceeds 15 °, the thickness of the essential part of the liver Y with respect to the maximum part X is less than 60%, so that it is impossible to form an efficient film and a sufficient thickness of the essential part of the liver Y is obtained. In this case, the film thickness of the maximum portion X also increases, so that air bubbles remain or broken air bubbles are generated on the coating film surface.

When the rear surface chamfering angle α is less than 5 °, when a slanted cross section is formed by wet grinding or polishing, chipping easily occurs at a corner 8 between the slanted cross section and the edge surface 7. Preferably, the back surface angle α is in the range of 7 ° to 13 °.

[0020]

EXAMPLES << Example 1 >> [Preparation of Sample] A reflective metal layer (100 nm thick) composed of a silver layer and a copper layer was formed on a 5 mm-thick soda-lime glass base plate by a conventional method, and further thereon. Apply a film of a backing paint mixed with anti-corrosion pigments, fillers, etc. to alkyd resin and heat (up to 150 ° C)
It was cured to form a backing coating (50 μm thick), which was cut into a size of 20 cm × 40 cm to prepare a number of mirror samples.

The sample was wet-ground from the periphery to the end surface of the back surface and polished (by 'resin diamond' with # 500 diamond grains embedded in the resin). , 10 °, 12.5 ° ---- 20 °.

Further, an epoxy-based resin stock solution (1 part by weight of a coupling agent and 25 parts by weight of a thinner containing toluene as a main component based on 100 parts by weight of a resin component) was mixed with an ether-based resin, an ester-based resin,
A mixed solvent composed of a ketone, etc., and other additives such as a film forming agent and an anti-sagging agent are added, and a resin solution of 63 to 70 wt%,
Prepare an edge-coating paint in the range of 35-28 wt% of the mixed solvent and 2-3 wt% of other additives, and apply it to a 5 mm
It was applied in various widths and film thicknesses. The film thickness is the maximum film thickness X after curing
200μm, 175μm, 150
μm ---- It was set to 100 μm.

[Appearance Observation and Film Thickness Measurement] The film thickness of the essential part Y of the liver was measured by breaking a part of the sample and observing the cross section under a mirror. Regarding the presence or absence of cracks, the mirror 8 was chamfered, and after polishing and finishing, the corner portion 8 of the sample before edge coating was observed with a loupe, and there was a crack in the mirror (a diameter of 2 mm or more) in one place. The evaluation was evaluated as x when the diameter was less than 2 mm but the presence of chipping was observed, and the mark where no clear chipping was observed was evaluated as o.

Regarding the sample after the formation of the edge-coating film, a sample having a clear (5 mm or more) dripping on the edge surface of the coating film and causing a problem in appearance was evaluated as “×”, and a sample with a dripping of less than 5 mm and 1.8 mm or more was evaluated. Δ, sagging when the sagging was less than 1.8 mm and caused no problem were evaluated with ○.

Further, the edge coating film was observed with a loupe, and among the air bubbles (internal air bubbles), those having air bubbles having a diameter of 1.5 mm or more were evaluated as x, and those having air bubbles having a diameter of less than 1.5 mm and 0.5 mm or more were evaluated. , A bubble having a diameter of less than 0.5 mm is present therein, or a bubble having a diameter of 1.5 mm or more is present in a bubble with a diameter of 1.5 mm or more. The case where less than the armpit was present was evaluated as Δ, and the case where no armpit was observed was evaluated as ○.

[Margining resistance test (1)-hot water + hydrochloric acid immersion test] After immersing the sample in high temperature water of 60 ° C in a hot water tank for 10 days,
It was taken out from the hot water tank and further immersed in a hydrochloric acid solution at 30 ° C. and 1 vol% in a hydrochloric acid tank for 3 days. Thereafter, the sample was taken out, washed with water, and the occurrence of rimming was observed.

The edging was evaluated based on the erosion depth (length) from the mirror end face toward the center of the mirror. The erosion value was 2 mm or more. The erosion value was less than 2 mm, and no erosion was observed. Those were evaluated as ○.

[Margining resistance test (2)-Mold killer stock solution immersion test] A 20 cm × 40 cm sample, 20 cm higher than the lower side (short side), manufactured by Johnson Co., Ltd., trade name “mold killer”
It was immersed in a stock solution of (chlorine-containing alkaline solution) at 20 ° C. for 120 days, and then taken out to observe the occurrence of rimming. Edge erosion is evaluated by the erosion depth (length) from the mirror end surface toward the center of the mirror. If the erosion value is 2 mm or more, × 2 mm
, Those with no erosion were evaluated as ○.

[Comprehensive evaluation] In each of the above measurements and tests,
The evaluation of only ○ was evaluated as ○, the evaluation partially evaluated as ○ (one item) was evaluated as ○ △, the evaluation evaluated only as △ or partially evaluated as ○ was evaluated as △, and the evaluation was partially evaluated as × Were evaluated as x. In addition, ○ is judged as good, △ as not good but acceptable range, and × as unacceptable. Tables 1 and 2 show the conditions and results.

Example 2 A mirror sample was manufactured by the same manufacturing method and means as in Example 1. However, the urethane resin stock solution (100 parts by weight of the resin component, 1 part by weight of a coupling agent, 25 parts by weight of a thinner mainly composed of xylene and toluene) as an edge coating paint, and ether-based, ester-based, ketone-based, etc. Add the mixed solvent, and other additives such as a film forming agent and an anti-sagging agent, and the resin stock solution 60-65wt%, the mixed solvent 38-33wt
% And other additives in the range of 2 to 3 wt%, which were applied in the same manner as in Example 1 using a coating roller.

Further, in the same manner as in Example 1, the appearance was observed, the film thickness was measured, and a mar resistance test was performed. Table 3 shows the conditions and results.

[Results] Similar results were obtained although there were some differences depending on the components of the edge coating film. Backside cutting angle α is 5
In the mirror sample having a degree of °, the film thickness of the main part Y of the liver is close to the film thickness of the maximum part X, and the margin resistance is extremely good in the film thickness range of the present invention. However, in any case, fine chipping is likely to occur in the corner portion 8 at the time of chamfering grinding. Further, as the width of the inclined surface 5 is longer, the width of the edge coating film becomes wider, and the amount of paint used also increases.

In the mirror sample having the back surface angle α of 7.5 to 12.5 °, the thickness of the essential part Y is as good as about 80% or more of the thickness of the maximum part X, and the corner part at the time of grinding is good. No chipping, and extremely good marring resistance within the scope of the present invention.

The mirror sample having the back chamfering angle α of 15 ° satisfies the requirement that the film thickness of the essential part Y is about 60% or more of the film thickness of the maximum part X, and within the scope of the present invention. Good barge. Backing angle α of the present invention, film thickness range X of edge coating film
Those deviating from Y and Y are generally inferior in appearance or rim resistance, and it is clear that good results were obtained within the scope of the present invention.

In the case where the back surface angle is 17.5 ° or more,
In some comprehensive evaluations, some are evaluated as △ or △. However, the film thickness of the vital part Y is about 50% or less of the film thickness of the maximum part X, and the margin coating efficiency is poor. It represents.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

According to the present invention, good results can be obtained in the anti-marching property, and the effect of preventing the occurrence of barge for a long period of time even under severe environmental conditions as a corrosion-resistant mirror can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a mirror.

[Description of Signs] 1 Corrosion-resistant mirror 2 Glass plate 3 Reflective metal film 4 Backing coating film 5 Bevel cross section 6 Edge coating film 7 Edge 8 Corner

Claims (4)

[Claims] 1. A mirror having a reflective metal layer formed on the back surface of a glass plate and a backing coating layer formed thereon, wherein a slanted surface is formed from the periphery of the back surface of the glass plate to an end surface, and the mirror is inclined with respect to the back surface. The angle of inclination of the surface is in the range of 5 to 15 °,
And, in order to cover the reflective metal layer exposed on the inclined surface, an edge coating film is formed from the periphery of the backing coating film to the inclined surface, and the thickness of the edge coating film Y on the exposed reflective metal layer is reduced.
60 μm or more, provided that the maximum thickness X of the edge coating film is 1
Corrosion-resistant mirror characterized in that the thickness is 70 μm or less. 2. The corrosion-resistant mirror according to claim 1, wherein the inclination angle of the inclined surface is set to 7 ° to 13 °. 3. The corrosion-resistant mirror according to claim 1, wherein the thickness of the edge coating film Y is 80 μm or more. 4. A method of manufacturing a mirror in which a reflective metal layer is formed on the back surface of a glass plate and a backing coating is laminated thereon, wherein the inclined surface which is beveled from the peripheral portion of the back surface of the glass plate to the end surface is formed by wet polishing. Then, in order to set the inclination angle of the inclined surface with respect to the back surface in the range of 5 to 15 °, and to cover the reflective metal layer exposed on the inclined surface, apply an edge coating film from the periphery of the backing coating film to the inclined surface. The thickness of the edging coating Y on the exposed reflective metal layer is 60 μm or more, and the maximum thickness X of the edging coating is formed by curing with a roller.
A method for producing a corrosion-resistant mirror, comprising forming a coating film having a thickness of 170 μm or less.