KR100910364B1 - Method for forming ceramic film on surface of silverware and silvered wares for prevention of discoloration - Google Patents

Abstract

The present invention relates to a method for forming a ceramic film for preventing surface discoloration of silver products and silver plated products mainly used as ornaments such as bags and cloths, necklaces, earrings, etc.

In order to prevent the deterioration of the quality of high-quality products that occur because silver products used for decorations, accessories, and jewelry such as high-quality bags are easily oxidized and discolored.

Forming a beryllium film to plate beryllium on the surface of silver and silver plated products by hanging a stainless plate on an anode in an electrolyte solution containing beryllium sulfate (BeSO ₄ · 4H ₂ O) and electroplating the silver or silver plated products on the cathode. Process;

Washing and drying the surface of the product having the beryllium film formed with buff polishing and a surfactant;

Washed and dried product was added to 1 liter of water and 20 to 80 cc of water glass (liquid sodium silicate), 5 to 60 g of sodium methane silicate, 5 to 30 g of tungsten sodium, and 5 to 10 g of molybdenum acid were mixed and formed into a ceramic coating solution. In the ceramic film forming step of dipping and drying,

It is to prevent the discoloration of silver and silver plated products to maintain the value of the goods for a long time.

Ceramic film, beryllium film, chemical conversion, Vickers hardness (Hv), silver surface discoloration factor

Description

Method for forming ceramic film on surface of silverware and silvered wares for prevention of discoloration}

The present invention relates to a method for forming a ceramic film for preventing surface discoloration of silver products and silver plated products, which are mainly used as decorative tools such as bags or coatings.

Metal surface treatment techniques have been developed to increase the utility value of metals.

Efforts are being made to protect metals from corrosion, to enhance the appearance and decorative value of metal products, and to extend their function as intended.

The surface treatment method of the metal developed so far is roughly as follows.

Electroplating method to form a film of other metal on metal or nonmetallic material using electric energy (electrolyte plated material is anode, anode is plated metal),

Chemical plating method to form a coating of other metal on the surface of metal or nonmetal using chemical change (substitution reaction of metal ion plated without electrode)

Hot-dip plating method to form a film by immersing in a molten metal in which the metal to be plated is melted,

Penetration plating method to diffuse and penetrate other metal into metal to form alloy coating,

Metal spraying method of forming a film by spraying another molten metal on the metal surface;

Chemical vapor deposition, which evaporates volatile metal salts and coats metal compounds with thermal decomposition of the surface of the plated object;

Cathode sputtering method in which a negative electrode material collides with a cationic particle in a vacuum to form a film on the surface of the plated body.

Vacuum deposition plating method for forming a film by depositing metal ions on a metal or nonmetal surface in vacuum;

Ion plating method that forms metal or gas into cation by glow discharge and accelerates cation to form film on negative electrode material,

As a method of thickening the surface oxide layer of a metal which is susceptible to oxidation, anodization method which promotes oxidation by immersing an oxide film-forming material in an aqueous solution such as sulfuric acid or oxalic acid (1) chromium,

Chemical conversion treatment to form a coating such as chromium salt or phosphate on the metal surface (different from anodization, in that the oxide film is different from the original metal)

Coating method to apply paint (paint) on metal surface,

Lining method that coats metal surface or nonmetal object surface with nonmetal materials such as rubber or synthetic resin,

A coating method to form a film such as a synthetic resin or enamel on a metal surface,

There is a surface hardening method that intensifies hardness by penetrating carbon, nitrogen, etc. on the metal surface.

As can be seen from the above, there are various methods of surface treatment, but it can be easily applied as a metal plating to form a film layer of metal with excellent corrosion resistance while maintaining specific color and gloss of silver on the silver surface with specific strength of 500Rv by micro Vickers hardness test. There is not much that can be done.

It is impossible to form a transparent film by various chemical treatment methods for increasing specific strength, and electroplating with a transparent, high specific strength and excellent corrosion resistance can be confirmed with any drug developed so far.

In addition, to immerse the silver product or silver plated product in the electrolyte for electroplating, it is not easy to manage either the acid bath or the alkaline bath.

Thus, the most widely used method is the electrodeposition coating method, which is immersed in an aqueous lacquer and dried or coated with an oil lacquer for thermal curing.

The most common method for surface treatment of automobile structures. However, as in the case of silver, maintaining the inherent color and luster of the painting is not so important, and the gloss is adjusted with lacquer, so it can only be used for economical reasons.

A high-end bag, a nice high-priced bag that looks very good with silver-plated decoration, a few months after the customer who bought it, the silver-plated tool has a noticeable discoloration,

The brilliant silver championship trophy was stored in a glass box and stored very preciously.

In particular, during the export of the bag, such as bags, the color of the furniture is discolored even before it arrives to the consumer due to temperature changes and the chemical composition of the leather also causes a problem of lowering the value of the product.

This silver discoloration is caused by chemical changes in the surface (corrosion oxidation).

The presence of many silver oxides such as AgCl, Ag ₂ S and Ag ₂ O is evidence that silver is a metal that is susceptible to oxidation.

It is bound to be a lower precious metal than other precious metals (platinum, rhodium, palladium, gold, etc.). It is an object of the invention to supplement this and to enhance the commercial value of silver and its products.

Target products to which the present invention is applied are silver products or silver plated products which are used as fashion jewelry, costume jewelry, accessory products or parts which are widely spread in recent years.

These products can be exposed to a wide variety of environments. High temperature and high humidity conditions such as the tropics, minus 50 degrees Celsius, extreme 60 degrees Celsius, image 60 degrees Celsius, exposure to snow and rain, sometimes coexist with leather, contact with automobile fumes, special hot spring environment, such as sulfur hot springs May also be exposed.

It can be very violent and can be hit or scratched by tens of thousands of other objects, such as coats and gloves, iron fences, railings, chairs, and desks.

This means that you have to consider all the things you talk about everyday.

To this end, weather resistance, chemical resistance, chemical resistance, abrasion resistance, and impact resistance must all be superior to the average.

It is a technical problem of the present invention to provide a method of surface treatment to withstand the original color and gloss as it is, even in this extremely adverse physical and chemical environment.

As a method of improving the corrosion resistance and abrasion resistance of silver products and silver plated products, it is usual to cope with forming a new metal layer by chemical treatment or paint as mentioned above, but in this case, the original color and luster It is almost impossible to keep it as it is.

So the challenge is to find a way to coat with glass material, but the problem is that glass material is easy to crack even under a small impact, and the crack is an opportunity to expose the discolored environment to a soft surface. It is a task.

Ceramic coatings of silver and silver plated products shall show no trace at all. This means that the product should be treated cleanly so that the report cannot determine whether it is coated.

There are many demonstrations that ceramic coated silver and silver plated products will not discolor after one year of coating, unless otherwise specified.

Particularly, there was no significant change in the constant temperature and humidity experiments with the treated products in combination with leather at a humidity of 80% and a temperature of 80 ° C.

Therefore, when such a product is released, the state of manufacture of silver and silver plated products is maintained as it is, and the quality of the product using this is intended to maintain the quality for a long time.

The present invention is to form a transparent and high hardness metal film made of beryllium metal on the surface of the silver plated product so as not to be affected by the lower layer plating, and to be well coated with the upper layer, and to pre-treat the metal film through buffing and washing. It consists of a process of forming a glass (ceramic) film on the surface of a beryllium-coated product.

However, the glass (ceramic) film forming process is the same for both silver and silver plated products, so in reality, a process of forming a valerian film on the surface of the silver plated product, a pretreatment process for applying a ceramic coating on the surface of the silver product, and a ceramic coating (film formation) It consists of three steps of the process.

1) Beryllium film formation process of silver plated product

   Pretreatment: Wash thoroughly after washing with surfactant to clean the surface to be plated

   Beryllium Plating

Liquid composition: for 1ℓ of water

Beryllium Sulfate (BeSO ₄ 4H ₂ O) 2.4 g / L

Ammonium hydroxide (NH ₄ OH) (ammonia water) 5-10 g / ℓ

The mixture is added to form, but ammonia water is added or reduced to pH 5.7 ~ 5.8.

The electrolytic solution was electroplated for 0.5 ~ 1 minute by attaching stainless steel plate to the anode and silver plated product on the cathode under the current density of 5mA / dℓ to form a beryllium film on the surface of the silver plated product.

2) Pretreatment Process of Silver Product

   Silver-plated products and silver products with a beryllium film as described above are sufficiently buffed and dried thoroughly with a surfactant so that the surface lubricity determines the success of ceramic coating.

3) Ceramic Coating Solution Composition and Coating Process

   Prior to ceramic coating, the following coating solution is prepared according to the desired coating thickness.

Foil coating (3 ~ 5㎛ thick)

In 1ℓ of water

Water glass (liquid sodium silicate) 1 type 20 ~ 30 ㏄ / ℓ

Sodium metasilicate 5 ~ 10 g / ℓ

Sodium tungsten 5 g / ℓ

Molybdenum acid 5 g / ℓ

Secondary coating (6 ~ 10㎛ thick)

In 1ℓ of water

Water glass (1 type) 40 ~ 50 ㏄ / ℓ

Sodium metasilicate 20 ~ 30 g / ℓ

10 g / l sodium tungsten

Molybdenum acid 7 g / ℓ

After coating (Thickness 10 ~ 15㎛)

In 1ℓ of water

Water glass (1 type) 60 ~ 80 ㏄ / ℓ

Sodium metasilicate 40 ~ 60 g / ℓ

Sodium tungsten 30 g / ℓ

Molybdenum acid 10 g / ℓ

Molybdenum acid is Na ₂ M ₀ O ₄ , sodium tungsten is Na ₂ WO ₄ , sodium metasilicate is Na ₂ SiO ₃ , water glass 1 species (liquid sodium silicate) is SiO ₂ 36 ~ 38wt% Na ₂ O 17 ~ 18% Fe ₂ O ₃ 0.05% by weight The residual weight is a mixture of insoluble precipitates (tacky organics).

When possible, the composition should be heated to about 50 ℃ for pure use and then put in the order of the above composition.

The ceramic coating liquid thus prepared is immersed in a liquid bath while the silver product is dried on a rack, and then hot air-dried immediately when it is considered that the product is sufficiently coated with gloss.

Hot air temperature 100 ~ 150 ℃ Please note that the coated surface may be rough or cracked if it is not sufficiently stirred or the wet liquid is not drenched on the surface of the product.

Claims (3)

Forming a beryllium film on the surface of the silver plated product by hanging a stainless plate on the anode in the electrolyte solution containing beryllium sulfate (BeSO ₄ · 4H ₂ O) and electroplating the silver or silver plated product on the cathode; Washing and drying the surface of the product having the beryllium film formed with buff polishing and a surfactant; Washed and dried product was added to 1 liter of water and 20 to 80 cc of water glass (liquid sodium silicate), 5 to 60 g of sodium methane silicate, 5 to 30 g of tungsten sodium, and 5 to 10 g of molybdenum acid were mixed and formed into a ceramic coating solution. A method of forming a ceramic film for preventing surface discoloration of silver and silver plated products, characterized in that the ceramic film is formed by dipping and drying. The method of claim 1, A beryllium electrolyte solution is formed by adding 2.4 g of beryllium sulfate and 5-10 g of ammonium hydroxide to 1 L of water, thereby preventing surface discoloration of silver and silver plated products, which is maintained at a pH of 5.7 to 5.8 by adding or decreasing ammonium hydroxide. Ceramic film forming method for the. The method of claim 1, One type of water glass (liquid sodium silicate) is 36 to 38% by weight of SiO ₂ , 17 to 18% by weight of Na ₂ O, 0.05% by weight of Fe ₂ O ₃ , and the remaining weight is formed of an insoluble precipitate (adhesive organic substance). A method of forming a ceramic film for preventing surface discoloration of silver and silver plated products, characterized in that.