JP2003293173A - Solution for peeling silver mirror film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare a solution for peeling silver mirror films which removes the silver mirror films formed on the surfaces of products consisting of various materials without damaging the materials and without dissolving the materials into the solution. <P>SOLUTION: This solution for peeling silver mirror films comprises an aqueous solution containing ferrocyanate, ferricyanate and a chlorine compound. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to glass, ceramics,
The present invention relates to a silver mirror surface remover for removing a silver mirror film formed on the surface of a product made of a material such as plastic, wood, metal, and bamboo.

[0002]

2. Description of the Related Art Since silver mirrors have excellent gloss and reflectivity, they are used in ornaments, mirrors, home appliances, automobile parts, building materials, communication equipment and the like. The silver mirror coating itself has abrasion resistance,
Because of poor adhesion, corrosion resistance, etc., a clear coating is generally formed on the film, and a mirror is copper-plated to prevent the silver mirror film from peeling off.

However, as a problem before such coating, the yield of treatment for forming a silver mirror film is
Always 100 for all products that should have a silver mirror coating
It is difficult to maintain at%. This is because, as described above, the product on which the silver mirror film is formed is made of a wide variety of materials and the shapes thereof are different. In particular, in the case of products having a complicated shape or a large surface area, a slight change in the treatment conditions for obtaining the silver mirror coating may cause a failure such as uneven glossiness or partial deposition of the silver mirror.

In such a case, it is necessary to peel off the silver mirror film that has been formed once and then perform plating again. In peeling the already formed silver mirror coating, a strong acid such as nitric acid or an aqueous solution of highly toxic sodium cyanide has been conventionally used as a peeling liquid.

[0005]

The nitric acid, which constitutes the conventionally used stripping solution, attacks plastics, metals, rubbers and organic substances, and sodium cyanide attacks some metals and organic substances. Furthermore, there is a problem regarding the disposal of nitric acid and sodium cyanide. Further, since such a stripping solution is one in which the silver mirror film is dissolved in the solution, another complicated processing operation is required to recover the silver itself from the stripping solution, which is not always economical. .

Therefore, a wide variety of materials such as glass, ceramics and other silicates, plastics, metals, woods, rubbers, bamboos, etc. constituting the products are peeled off with a silver mirror film so as not to erode these materials as much as possible. Liquid is desired.

Further, if the silver mirror film peeling liquid does not dissolve the silver mirror film in the liquid but simply peels it into the liquid and drops it off, the peeled film is scooped out, or
It can be separated by filtration, and silver can be easily recycled. Furthermore, the life of the stripper becomes longer,
Suitable as an environmental measure.

[0008]

In order to solve the above-mentioned problems of the conventional silver mirror coating stripper, the inventor has conducted diligent research and made an aqueous solution containing ferrocyanate, ferricyanate and a chlorine compound. It was found that the silver mirror coating is peeled off from the material without being dissolved in the liquid by coating the silver mirror coating on the silver mirror coating or by immersing the silver mirror coating in the aqueous solution.

Therefore, an object of the present invention is to provide a silver mirror coating stripping solution for stripping a silver mirror coating formed on the surface of a product made of a material such as glass, ceramics, plastic, metal, wood, rubber, bamboo, etc. A silver mirror film stripping solution comprising an aqueous solution containing 0.01-0.2 mol of ferrocyanate, 0.01-0.2 mol of ferricyanate, and 10 g or more (as chlorine) of a chlorine compound per liter. To do.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The stripping solution according to the present invention contains 0.01 to 0.2 mol of ferrocyanate, preferably 1 to 1 liter of water.
0.02-0.06 mol, ferricyanate 0.01-0.2 mol,
It is preferably an aqueous solution containing 0.02 to 0.06 mol, 10 g or more (as chlorine) of a chlorine compound, preferably 25 to 100 g.

Potassium ferrocyanide or sodium ferrocyanide can be used as the ferrocyanate, and potassium ferricyanide or sodium ferricyanide can be used as the ferricyanate.

Examples of chlorine compounds include alkali metal chlorides such as sodium chloride, potassium chloride and lithium chloride; alkaline earth metal chlorides such as magnesium chloride, calcium chloride and barium chloride; sodium hypochlorite and hypochlorous acid. Chlorine oxyacids such as potassium, calcium hypochlorite, sodium chlorite, barium chlorite, sodium chlorate, potassium chlorate, barium chlorate, sodium perchlorate, potassium perchlorate or barium perchlorate salt;
In addition, aluminum chloride, iron chloride, manganese chloride, etc. can be used.

The water used may be tap water.

Next, specific examples using the stripping solution according to the present invention will be described with reference to the following examples.

The silver mirror coating used in the examples is formed as follows. That is, first, the surfaces of various materials are cleaned. For plastic, rubber, wood, bamboo, etc., clean the surface with ethyl alcohol,
Degrease with a treatment agent that will not damage materials such as commercially available neutral detergent, wash with water, and dry thoroughly. Further, if necessary, a commercially available special coating material is applied and dried sufficiently. For glass and ceramics, decontaminate the surface with ethyl alcohol, wash with water, and dry. Metals are often contaminated with oil, rust, oxides, etc. Therefore, they should be thoroughly degreased and rusted before being washed with water.

Next, a conventionally known activation treatment agent is sprayed onto the thus cleaned surface by a spray gun to deposit stannous ions. By this process,
The hydrophilicity of the surface is increased. Generally, the activation treatment agent is an aqueous solution in which 5 g of stannous chloride and 10 ml of 35% hydrochloric acid are dissolved in 1 l of tap water.

After the activation treatment, it is washed with deionized water such as ion exchanged water or purified distilled water.

Next, a silver mirror plating solution is sprayed with a double spray gun to form a silver mirror film, washed with deionized water, and dried.

The method for preparing the used silver mirror reaction treating agent is as follows.

First, 0.12 mol of silver nitrate was dissolved in 1 liter of deionized water to prepare solution A, and 0.44 mol of ammonia was separately dissolved in 1 liter of deionized water to prepare solution B. Immediately before use, mix A and B in the same volume of 1: 1 and
Use the metal salt solution.

Separately, 0.21 formalin in 1 liter of deionized water
Dissolve the moles to obtain a reducing agent solution. At the time of use, both solutions of the metal salt solution and the reducing agent solution are sprayed with a double spray gun to form a silver mirror film.

[0022]

[Example 1] Tap water in an amount equivalent to 70% of the total amount of the prepared aqueous solution was placed in a container, and 0.06 mol of sodium ferrocyanide, 0.02 mol of sodium ferricyanide, and calcium chloride dihydrate were added to 1 l of water. 105 g (50 g as chlorine) were sequentially added and dissolved, and the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

The prepared stripping solution was soaked in absorbent cotton and the silver mirror coating formed as described above was lightly wiped on the rough surface of the commercially available frosted glass, and the silver mirror coating instantly adhered to the absorbent cotton and was completely peeled from the substrate. . There was no evidence of erosion on the glass surface.

[0024]

Example 2 Tap water in an amount corresponding to 70% of the production amount was put in a container, and 0.02 mol of sodium ferrocyanide, 0.04 mol of sodium ferricyanide and 120 g of lithium chloride (100 g as chlorine) were added to 1 l of water. Then, the solution was sequentially added and dissolved, and the remaining tap water was further added to prepare an aqueous solution to obtain a stripping solution.

[0025] This absorbent is soaked in absorbent cotton, and the surface of the silver mirror coating formed as described above is lightly wiped on a commercially available transparent acrylic resin plate. Instantly, the silver mirror coating adheres to the absorbent cotton and is completely removed from the substrate. did. There was no evidence of discoloration or erosion on the acrylic resin surface.

[0026]

Example 3 Tap water in an amount corresponding to 70% of the production amount was placed in a container, and 0.02 mol of potassium ferrocyanide, 0.06 mol of potassium ferricyanide, and 60 g of potassium chloride (28 g as chlorine) were sequentially added to 1 l of water. , And then the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

As a test sample, an ABS (acrylonitrile-butadiene-styrene) resin plate coated with a commercially available special paint and having a silver mirror film formed thereon as described above was used. When this test sample was immersed in the prepared stripping solution while shaking at a solution temperature of 20 ° C., the silver mirror coating was completely stripped from the substrate after about 10 seconds.

The peeled silver mirror coating is subdivided into a peeling liquid and floated, and all can be scooped with a net of 1 mm mesh. Further, no trace of dissolution in the coating is seen, and the surface of the coating after peeling However, there was no evidence of erosion.

Further, soak this absorbent with absorbent cotton,
Even when the surface of the silver mirror film was lightly wiped, the silver mirror film immediately adhered to the absorbent cotton and completely peeled off from the substrate. No evidence of erosion was found on the surface of the coating after peeling.

[0030]

Example 4 Tap water in an amount corresponding to 70% of the production amount was placed in a container, and 0.03 mol of potassium ferrocyanide, 0.03 mol of sodium ferricyanide and 120 g of sodium chloride (72 g as chlorine) were sequentially added to 1 l of water. Was added and dissolved, and the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

As a test sample, a brass plate (JIS H 31
00: Alloy No. C2801) on which a silver mirror film was formed as described above was used, and this test sample was immersed in the prepared stripping solution at a liquid temperature of 20 ° C. while rocking.
After 0 minutes, the silver mirror coating was completely peeled off from the brass surface. The peeled silver mirror coating was fragmented and floated in the peeling solution, and no trace of dissolution was observed. Further, on the surface of the brass plate, discoloration was recognized as compared with that before the formation of the silver mirror film, but traces of corrosion were very slight.

[0032]

Example 5 The stripping solution prepared in Example 4 was tested on test samples made of other materials.

A polished steel plate (JIS G 3141) was plated with bright nickel, and a silver mirror coating was formed thereon as described above, which was used as a test sample.

Such a test sample was added to a stripping solution,
When immersed while rocking at a liquid temperature of 20 ° C, after about 5 minutes,
The silver mirror coating was completely peeled off from the nickel-plated surface. The peeled silver mirror coating was fragmented and floated in the peeling solution, and no trace of dissolution was observed. The surface of nickel plating is
A slight discoloration was observed as compared with that before the formation of the silver mirror film, but no trace of corrosion was observed.

[0035]

Example 6 Tap water in an amount equivalent to 70% of the production amount was put in a container, and 0.02 mol of sodium ferrocyanide, 0.02 mol of potassium ferricyanide and 120 g of magnesium chloride hexahydrate (120 g as chlorine) were added to 1 l of water. 42g)
Were sequentially added and dissolved, and the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

The lauan plate was ground with a planer to make the surface smooth, and the one having the silver mirror film formed thereon as described above was used as a test sample.
When it was dipped while being rocked at, the silver mirror coating was completely peeled off from the surface of the rawan after about 1 minute. The peeled silver mirror coating was fragmented and floated in the peeling solution, and no trace of dissolution was observed.

Further, the surface of the Lauan after peeling did not show any signs of discoloration or corrosion as compared with before the formation of the silver mirror film.

[0038]

Example 7 The stripping solution prepared in Example 6 was tested on test samples made of other materials.

A commercially available natural rubber sheet on which a silver mirror film was formed as described above was used as a test sample.

Such a test sample was added to a stripping solution,
When immersed while rocking at a liquid temperature of 20 ° C., the silver mirror coating completely peeled off from the rubber surface after about 40 seconds. The peeled silver mirror coating was fragmented and floated in the peeling solution, and no trace of dissolution was observed.

No evidence of dissolution or corrosion was found on the surface of the rubber after peeling.

[0042]

Example 8 Tap water in an amount corresponding to 70% of the production amount was placed in a container, and 0.1 mol of potassium ferrocyanide, 0.1 mol of potassium ferricyanide and 55 g of manganese chloride tetrahydrate (chlorine per liter of water) were added. 20 g) was sequentially added and dissolved, and the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

The absorbent is soaked with the prepared stripping solution, and the surface (outer periphery) of the bamboo is wiped with the silver mirror coating formed as described above. The silver mirror coating adheres to the absorbent cotton after being wiped 3 to 5 times. Almost peeled off. The peeled silver mirror film subdivided into the peeling liquid and floated, and no trace of dissolution was observed. Also, when immersed in this peeling liquid while shaking at a liquid temperature of 20 ° C., the silver mirror film was about 5 minutes later. The film peeled off completely.

In all cases, the surface of the bamboo after peeling was the same as before the silver mirror film was formed, and no trace of corrosion was observed.

[0045]

Example 9 Tap water in an amount corresponding to 70% of the production amount was put in a container, and 0.1 mol of potassium ferrocyanide, 0.05 mol of potassium ferricyanide and 49 g of sodium chlorite (converted to chlorine) were added to 1 l of water. Were sequentially added and dissolved, and the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

As a test sample, a commercially available ABS resin plate on which a silver mirror film was formed as described above was used.
This test sample was added to the prepared stripping solution at a liquid temperature of 20 ° C.
When immersed while rocking, the silver mirror coating was completely peeled from the substrate after about 5 minutes.

The peeled silver mirror film was subdivided and floated in the peeling liquid, and no trace of dissolution was observed.
On the surface of the BS resin, neither discoloration nor evidence of erosion was observed.

[0048]

Example 10 Tap water in an amount corresponding to 70% of the production amount was placed in a container, and 0.1 mol of potassium ferrocyanide, 0.05 mol of potassium ferricyanide and 34 g of sodium hypochlorite (converted to chlorine) per liter of water. ) Was sequentially added and dissolved, and the remaining tap water was added to prepare an aqueous solution, which was used as a stripping solution.

As a test sample, a commercially available ABS resin plate on which a silver mirror film was formed as described above was used.
This test sample was added to the prepared stripping solution at a liquid temperature of 20 ° C.
When immersed while rocking at, the silver mirror coating completely peeled from the substrate after about 10 seconds.

The peeled silver mirror film was subdivided and floated in the peeling liquid, and no trace of dissolution was observed.
On the surface of the BS resin, neither discoloration nor evidence of erosion was observed.

[0051]

According to the present invention, in a stripping solution comprising an aqueous solution containing a ferrocyanate, a ferricyanate and a chlorine compound, this solution is applied to the surface of a silver mirror coating and rubbed, or this aqueous solution is used. By immersing in and shaking, the material can be peeled off in a short time without damaging the material and without dissolving the silver mirror coating in the aqueous solution.

Claims (4)

[Claims] 1. A silver mirror coating stripping solution for stripping a silver mirror coating formed on the surface of a product made of a material such as glass, ceramics, plastic, metal, wood, rubber, bamboo, etc., and ferrocyanic acid per liter of water. A silver mirror film stripping solution comprising an aqueous solution containing 0.01-0.2 mol of a salt, 0.01-0.2 mol of a ferricyanate and 10 g or more (as chlorine) of a chlorine compound. 2. The silver mirror film stripping solution according to claim 1, wherein the ferrocyanate is potassium ferrocyanide or sodium ferrocyanide, and the ferricyanate is potassium ferricyanide or sodium ferricyanide. 3. The chlorine compound is a metal chloride selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides, chlorine oxyacid salts, aluminum chloride, iron chloride and manganese chloride. The silver mirror film peeling solution according to 2. 4. The alkali metal chloride is sodium chloride,
Potassium chloride or lithium chloride, alkaline earth metal chloride is magnesium chloride, calcium chloride or barium chloride, chlorine oxyacid salt is sodium hypochlorite, potassium hypochlorite, calcium hypochlorite , Sodium chlorite, barium chlorite, sodium chlorate, potassium chlorate, barium chlorate, sodium perchlorate, potassium perchlorate or barium perchlorate,
The silver mirror film peeling liquid according to claim 3.