JP2003013240A - Activation agent for silver mirror - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain stability of an activation agent over a long period which is used for activating the surface of a product on which a silver mirror film is to be formed, when forming a silver mirror coating on the surface of the product consisting of various materials, and to improve hydrophilicity of the activation agent in order to allow it to be applied with a spray process and a dipping process. SOLUTION: The method for preparing this activation agent comprises blowing oxygen into an aqueous solution including a stannous compound and hydrogen chloride, and further adding ferric chloride to the aqueous solution.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the formation of a silver mirror coating on the surface of a product made of a material such as plastic, metal, glass, rubber, ceramics, wood, bamboo, leather and Styrofoam. The present invention relates to an activation treatment agent used for activating a surface to be formed (hereinafter, referred to as "silver mirror film formation surface").

[0002]

2. Description of the Related Art Materials such as automobile parts, interior decorations, fishing tackle products, home appliances, communication equipment products, Buddhist fittings, construction materials such as plastics, metals, glass, rubber, ceramics, wood, bamboo, leather and Styrofoam. In various products, the silver mirror film is formed on the surface of the product mainly for the purpose of decoration. Further, the silver mirror film is also formed on an electromagnetic wave shield product for the purpose of blocking electromagnetic waves.

The formation of a silver mirror film in a product made of such a material is usually carried out by a method consisting of the following steps.

That is, first, the surface of the material of various materials on which the silver mirror film is formed is subjected to a treatment for forming a surface suitable for forming the silver mirror film. For example, when the material is glass or porcelain, degreasing with a detergent is performed as necessary depending on the state of alcohol, acetone, or surface dirt. When the material is plastic, rubber, wood, etc., a special lacquer is applied to seal the surface scratches and fine holes to obtain the luster of the silver mirror, and then degreased with a detergent if necessary. When the material is a metal, the pretreatment is carried out by any of the above methods depending on the material and the surface condition. The silver mirror film-forming film is activated by spraying an activation treatment agent on the clean surface thus obtained or by immersing it in the activation treatment agent, and stannous ions (Sn ²⁺ ) Is attached. This stannous ion is a silver ion (A
g ⁺ ) acts as a necessary displacing agent for precipitating metallic silver (Ag).

[0005]

[Chemical 1]

Once this substitution has occurred, the reducing agent used in the electroless plating bath promotes the precipitation of silver. That is, the activated surface is immersed in a conventionally known electroless plating bath generally composed of a mixture of a silver solution containing silver nitrate and ammonia water and a reducing solution containing a reducing agent, or the electroless plating. A silver mirror film is formed by spraying the bath.

[0007]

The activation treatment agent used in the activation step in the method for forming a silver mirror film is generally an aqueous solution containing hydrochloric acid and stannous chloride (SnCl ₂ ) as main components.

Stannous chloride is a hydroxyl group (O
It tends to react with H ⁻ ) to form a white precipitate of a basic salt (SnClOH). Although the reaction of forming a basic salt is suppressed by acidifying the aqueous solution by adding hydrochloric acid, the reaction proceeds and the basic salt begins to precipitate in about 2-10 days after production depending on the ambient temperature. It becomes unusable within a short period of time and its life is short. Further, such a precipitate causes the nozzle of the spray gun to be clogged, hindering the progress of the activation step, and as a result, it is difficult to perform the activation step by a spray method. Further, the adhesion of the precipitate to the surface on which the silver mirror film is to be formed may cause inconvenience that the formed silver mirror film becomes uneven.

In addition, the concentration of tin dissolved in the aqueous solution decreases with the formation of the basic salt precipitate, and the hydrophilicity of the activation treatment agent on the surface on which the silver mirror film is to be formed decreases. Therefore, it is necessary to use a large amount of the activation treatment agent or to repeatedly apply the activation treatment agent in order to obtain a certain amount of the activation treatment agent to wet the surface on which the silver mirror film is to be formed.

[0010]

[Means for Solving the Problems] The inventors of the present invention have conducted diligent research to solve the above problems of conventional activation treatment agents, and blow oxygen into an aqueous solution containing a stannous compound and hydrogen chloride. As a result, it is possible to obtain an activation treatment agent in a yellow transparent state having a long life, and by further adding ferric chloride, the obtained activation treatment agent only has a long life. However, they have found that they have improved hydrophilicity, and have reached the present invention.

Therefore, the object of the present invention is to form a silver mirror coating on the surface of a product made of a material such as plastic, metal, glass, rubber, ceramics, wood, bamboo, leather, and styrofoam, in order to form a silver mirror coating on the product. In the activation treatment agent used to activate the forming surface, 1 liter of water is used.
Stannous compound 0.01-0.22 mol and hydrogen chloride 0.02
It is an object of the present invention to provide an activation treatment agent which comprises blowing at least 25 liters of oxygen per liter of an aqueous solution containing -0.48 mol.

Another object of the present invention is to provide an aqueous solution containing 0.01-0.22 mol of stannous compound, 0.02-0.48 mol of hydrogen chloride and 0.001-0.04 mol of ferric chloride per liter of water, and oxygen per liter of the aqueous solution. It is to provide an activation treatment agent which is blown with at least 25 liters.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In preparing the activation treatment agent according to the present invention, first, for example, from among stannous chloride, stannous oxide, stannous sulfate, stannous borofluoride, etc. At least one stannous compound selected.
01-0.22 mol, preferably 0.02-0.07 mol and hydrogen chloride
An aqueous solution containing 0.02-0.48 mol, preferably 0.11-0.17 mol, is prepared. In order to dissolve the stannous compound during preparation of the aqueous solution, an acid such as sulfuric acid or borofluoric acid can be used if necessary. Water is tap water, ion-exchanged water,
Any of purified distilled water may be used. After the preparation of the aqueous solution, oxygen is blown into the aqueous solution in an amount of at least 25 l, preferably at least 30 l per 1 l of the aqueous solution to perform aeration treatment. It is also possible to use air instead of oxygen.

The activation treatment agent thus obtained is a yellow transparent solution, and this state is maintained for 4 to 6 months or longer, and the activity is not reduced.

According to another embodiment of the invention, in addition to the stannous compound and hydrogen chloride, ferric chloride is added in an amount of 0.001 to 0.04 mol, preferably 0.0015 to 0.006 mol, per liter of water, and an aqueous solution is prepared. After the preparation, the aeration treatment with oxygen (air can also be used) is performed as described above.

This activation treatment agent is also a yellow and transparent solution, and such a state persists for 4 to 6 months or more, and not only the activity is not deteriorated, but also the hydrophilicity to the surface on which the silver mirror film is formed is extremely good. Is.

Next, a specific example of the silver mirror film forming method using the activation treating agent of the present invention will be described.

Among various materials, for plastics such as ABS (acrylonitrile-butadiene-styrene) resin, rubber, wood, leather, etc., surface oil and other stains may damage materials such as ethyl alcohol and detergent. Degrease with no treatment and dry thoroughly. Then, a special commercial lacquer paint is applied and dried sufficiently. If glass, degrease with ethyl alcohol. Ceramics may be treated in the same manner as glass, but if it is porous, it is treated in accordance with plastics. In the case of metal, it is often contaminated with oil and rust, and after being thoroughly degreased and rusted,
If necessary, treat according to plastic.

The silver mirror film-formed surface thus prepared is sprayed with the activation treatment agent of the present invention using a spray gun,
Alternatively, the activation process is performed by a dipping method. The liquid temperature at this time is 5-35 ° C, preferably 15-25 ° C.

After the activation treatment, it is washed with ion-exchanged water or purified distilled water, and the process proceeds to the subsequent silver mirror reaction treatment step.

A conventionally known silver electroless plating bath is generally sprayed with a spray gun to carry out a silver mirror reaction treatment. After the treatment, it is washed with ion-exchanged water or purified distilled water and dried well.

When a silver mirror coating is formed on the lacquer coating after drying, 60-85 ° C. in a constant temperature drying oven,
Heat treatment is preferably performed at 70-75 ° C. for 1-10 minutes, preferably 5 minutes. By this heat treatment, it is possible to obtain a silver mirror coating having very good adhesion to the material in the cellophane tape pressure-sensitive peeling test.

Furthermore, by applying a clear coating of a top coat on this silver mirror coating, the adhesion resistance, corrosion resistance, abrasion resistance, discoloration resistance, etc. are further improved.

Next, a method for forming a silver mirror film according to the present invention,
Activation treatment agent, silver mirror reaction treatment agent (silver solution, reducing agent solution)
Etc. are demonstrated based on an Example.

[0025]

Example 1 Tap water in an amount corresponding to 70% of the production amount was placed in a container, and 35% hydrochloric acid and stannous chloride were sequentially added in an amount corresponding to 0.23 mol (as hydrogen chloride) and 0.09 mol per liter of water, respectively. It was added and dissolved, and then tap water was added to make the total amount 100%. After the preparation, aeration treatment was carried out for 4 hours at an oxygen blowing rate of 80 l / l · hour to prepare an activation treatment agent composed of hydrochloric acid acidic solution. The activation treatment agent thus obtained was transparent without turbidity even when stored at room temperature for 6 months. Using this activation treatment agent, activation treatment was performed on the surface of the material on which the silver mirror film was formed by spraying with a spray gun and dipping. A sufficient activation effect was observed in the activation treatment by any method.

For comparison, in the same manner as the above preparation method,
However, the activation treatment agent was prepared without performing aeration treatment. The activation treatment agent obtained by this method became unusable after 3 days from the start of turbidity, and after 7 days, a precipitate was formed.

[0027]

Example 2 A container was charged with tap water in an amount equivalent to 70% of the production amount, and 35% hydrochloric acid, ferric chloride and stannous chloride were added.
0.17 moles per liter of water (as hydrogen chloride),
An amount corresponding to 0.009 mol and 0.11 mol was sequentially added and dissolved, and tap water was further added to make the total amount 100%. After the preparation, aeration treatment was carried out for 1 hour at an oxygen blowing rate of 30 l / l · hour to prepare an activation treatment agent for hydrochloric acid acidic solution. The obtained activation treatment agent was transparent without turbidity even after 5 months. Using this activation treatment agent, activation treatment was performed on the surface of the material on which the silver mirror film was formed by spraying with a spray gun and dipping. A sufficient activation effect was observed in the activation treatment by any method.

For comparison, in the same manner as in the above preparation method,
However, the activation treatment agent was prepared without performing aeration treatment with oxygen. The activation treatment agent obtained by this method began to become turbid 4 days after preparation, and a precipitate was formed 8 days later.
It was unusable.

[0029]

Example 3 A container was charged with tap water in an amount equivalent to 70% of the production amount, and 35% hydrochloric acid, ferric chloride and stannous chloride were added,
0.11 mol (as hydrogen chloride), 0.004 mol and 0.044 mol per 1 liter of water were sequentially added and dissolved, and tap water was added to make the total amount 100%. After preparation, 80l / l
Aeration treatment was carried out at an oxygen blowing rate of time to prepare an activation treatment agent for hydrochloric acid acidic solution. The resulting activation treatment agent is 4
It was transparent without turbidity even after months passed. Using this activation treatment agent, activation treatment was performed on the surface of the material on which the silver mirror film was formed by spraying with a spray gun and dipping. A sufficient activation effect was observed in the activation treatment by any method.

For comparison, in the same manner as in the above preparation method,
However, the activation treatment agent was prepared without adding ferric chloride. In order to obtain the same wetting as that obtained by the activation treatment agent of the present invention, the activation treatment agent obtained by this method needs to be sprayed with a spray gun 1-4 times more.

[0031]

Example 4 Similar to the preparation method described in Example 3, except that the amounts of 35% hydrochloric acid, ferric chloride and stannous chloride are 3%.
The activation treatment agent was produced as a double. This was diluted three times with tap water (concentration is the same as in Example 3). This liquid was transparent without turbidity even after 4 months.

[0032]

Example 5 Tap water in an amount equivalent to 10% of the production amount was put in a container, and 35% hydrochloric acid and stannous oxide were added per 1 liter of water.
0.11 mol (as hydrogen chloride) and 0.03 mol in an amount corresponding to 0.03 mol were sequentially added, and after dissolution, ferric chloride was added to 0.002 per liter of water.
It was added and dissolved in an amount corresponding to mol, and tap water was further added to make the total amount 100%. After the preparation, aeration treatment was carried out at an oxygen blowing rate of 80 l / l · hour to prepare an activation treatment agent for a hydrochloric acid acidic solution. The obtained activation treatment agent was transparent without turbidity even after 5 months. Using this activation treatment agent, activation treatment was performed on the surface of the material on which the silver mirror film was formed by spraying with a spray gun and dipping. A sufficient activation effect was observed in the activation treatment by any method.

[0033]

[Example 6] A commercially available undercoat paint (Ohashi Chemical Industry Co., Ltd .; Under Black No. 0128) was applied to a degreased, water-washed and dried surface of an ABS resin product with a curing agent and a thinner at 10: 2: 4-5. Was mixed and applied at a ratio of 1, then the solvent was scattered, and then dried at 80 ° C. for 30 minutes.
The activation treatment agent prepared in Example 1 was sprayed on this with a spray gun to perform activation treatment. After the activation treatment, it was washed with pure water.

Then, the silver mirror reaction treating agent was sprayed with a spray gun. After spraying, wash with pure water and dry.
Heat treatment was performed at 0-75 ° C for 5 minutes. As a result, a mirror-finished silver mirror film having good adhesion was formed.

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 water to prepare a solution A, and 0.44 mol of ammonia was dissolved in 1 liter of water to prepare a solution B. The solutions A and B were prepared before use. Mix at the same volume of 1: 1 to make a metal salt solution. Next, 0.21 mol of formalin is dissolved in 1 liter of water to prepare a reducing agent solution. At the time of use, both solutions are sprayed with a double spray gun to give a silver mirror reaction treatment agent.

[0037]

[Example 7] A commercially available base coat paint for enhancing the adhesion between a metal and a coating film on the surface obtained by slightly etching an aluminum material (alloy name JIS5052) product with caustic alkali, thoroughly washing with water and drying. (Ohashi Chemical Industry Co., Ltd .; base coat black) with thinner 10: 5-
The mixture was mixed at a ratio of 6 and applied, and then the solvent was scattered and dried at 140 ° C. for 40 minutes. On top of this, a commercially available undercoat paint (Ohashi Chemical Co., Ltd .; Under Black No. 0128) was added together with a curing agent and thinner at 8: 2: 4-5.
Was mixed and applied at a ratio of 1, then the solvent was scattered, and then dried at 80 ° C. for 30 minutes. The activation treatment agent prepared in Example 2 was sprayed on this with a spray gun to perform activation treatment. After the activation treatment, it was washed with pure water.

Then, the same silver mirror reaction treating agent as in Example 6 was sprayed with a spray gun, washed with pure water, dried and then 80
When heat-treated at -85 ° C for 3 minutes, a mirror-finished silver mirror film with good adhesion was formed.

[0039]

[Example 8] Magnesium material (ASTM AZ by die casting
91) After washing the product with methyl ethyl ketone, degreasing it with alkali, thoroughly washing it with water, and drying it on the surface, a commercially available base coat paint (Ohashi Chemical Industry Co., Ltd.) to enhance the adhesion between metal and coating film. ; Base coat black)
Is mixed with thinner at a ratio of 10: 5-6 and applied,
Then, after the solvent was scattered, it was dried at 140 ° C. for 40 minutes. A commercially available undercoat paint (Ohashi Chemical Co., Ltd .; Under Black No. 0128) was mixed and applied with a curing agent and a thinner at a ratio of 8: 2: 4-5, and then the solvent was scattered. After that, it was dried at 80 ° C. for 30 minutes. The activation treatment was performed by immersing this in the activation treatment agent obtained in Example 3. After activation, it was washed with pure water.

Then, the same silver mirror reaction treating agent as in Example 6 was sprayed with a spray gun, washed with pure water, dried and then 60-
When heat treatment was performed at 65 ° C. for 10 minutes, a silver mirror film having a mirror surface with good adhesion was formed.

[0041]

Example 9 A brass plate was washed with acetone, degreased with alkali, washed with water, neutralized with dilute sulfuric acid, and washed with water. The activation treatment agent prepared in Example 2 was sprayed on this with a spray gun to perform activation treatment. After the activation treatment, it was washed with pure water.

Then, the same silver mirror reaction treating agent as in Example 6 was sprayed with a spray gun, washed with pure water, and dried. As a result, a mirror-finished silver mirror film was formed.

[0043]

Example 10 The transparent plate glass was thoroughly washed with a neutral detergent and then washed with water. The activation treatment agent prepared in Example 3 was sprayed on this with a spray gun to perform activation treatment. After the activation treatment, it was washed with pure water.

Then, the same silver mirror reaction treating agent as in Example 6 was sprayed with a spray gun, washed with pure water, and dried. This formed a silver mirror coating on the silver surface.

[0045]

[Example 11] To 0.58 mol of concentrated sulfuric acid, 0.12 mol of stannous sulfate was added, and the liquid which was stirred to form a mud was gradually added to 700 ml of tap water contained in another container while stirring. Then
Dissolved. Then, 0.06 mol of 35% hydrochloric acid was added and stirred, and tap water was further added to adjust the total amount to 1 liter. After preparation,
Aerated at a rate of 80 l / l · h for blowing oxygen into sulfuric acid
An activation treatment agent for a hydrochloric acid-mixed acidic solution was prepared. The obtained activation treatment agent was transparent without turbidity even after 4 months. Using this activation treatment agent, activation treatment was performed on the surface of the material on which the silver mirror film was formed by spraying with a spray gun and dipping. A sufficient activation effect was observed in the activation treatment by any method.

After the activation treatment, it is washed with pure water, and then
The silver mirror reaction treating agent was sprayed with a spray gun. After spraying, it was washed with pure water, dried, and heat-treated at 70 ° C. for 5 minutes. As a result, a mirror-finished silver mirror film having good adhesion was formed.

The method for preparing the used silver mirror reaction treating agent is as in Example 6.

[0048]

INDUSTRIAL APPLICABILITY According to the present invention, by blowing oxygen (or air) into an aqueous solution containing a stannous compound and hydrogen chloride, it is possible to prevent the formation of a basic salt and the shortening of the life due to precipitation, which leads to a long-term use. An activated treating agent having an improved longevity in which a clear solution state is maintained without precipitation over a period of time is obtained.

Furthermore, the oxygen aeration aqueous solution containing ferric chloride in addition to the stannous compound and hydrogen chloride not only has an improved life, but also has a hydrophilic property with respect to the undercoat layer coated with a special lacquer. Is improved, and a very useful activation treatment agent can be obtained.

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Claims (3)

[Claims] 1. When forming a silver mirror film on the surface of a product made of a material such as plastic, metal, glass, rubber, ceramics, wood, bamboo, leather, or styrofoam, the surface on which the silver mirror film is formed is activated. In the activation treatment agent used for the stannous compound 0.01-0.
An activation treating agent comprising blowing an aqueous solution containing 22 mol and 0.02-0.48 mol of hydrogen chloride with at least 25 l of oxygen per 1 l of the aqueous solution. 2. Ferric chloride 0.001 per liter of aqueous solution
The activation treatment agent according to claim 1, which is compounded with -0.04 mol. 3. The stannous compound is selected from stannous chloride, stannous oxide, stannous sulfate, stannous borofluoride, or a mixture thereof. Activation treatment agent.