KR20080103238A - Structure of decorative multi-layer coating film with trivalent chromium plating layer as outermost layer and not using nickel and plating method - Google Patents

Abstract

The present invention relates to a structure of a multi-layered coating film for decoration as the outermost layer of a trivalent chromium plating layer without using nickel and a plating method thereof, and an object thereof is a sandwich type triple layer having excellent adhesion and corrosion resistance between plating layers on copper or alloy plating layers. Forming a plating layer, and forming a trivalent chromium plating layer, the structure of a decorative multilayer plating film having no trivalent chromium plating layer having excellent corrosion resistance, abrasion resistance, and mechanical properties without a nickel plating layer as an outermost layer and not using nickel, and its plating To provide a way.

The present invention forms a base plating layer by copper, binary alloy or ternary alloy on the object, and sequentially stacks the precious metal strike plating layer, the silver plating layer and the precious metal plating layer on the alloy plating layer to form a sandwich type precious metal triple plating layer. The trivalent chromium plating layer is formed on the sandwich-type noble metal triple plating layer to form a multilayer trivalent chromium plating film structure containing no nickel.

Description

Structure of electro-plated multi-layer metal film with out-most tri-valent chromium film and without nickel film for decoration parts}

1 is an exemplary view showing a multi-layer plating film structure according to the present invention

* Explanation of symbols for main parts of the drawings

(10): Substrate (20): Underplating layer

(21): electroless copper plating layer (22): electric copper plating layer

(23): alloy plating layer

(30): sandwich type precious metal triple plating layer

(31): Precious metal strike plating layer (32): Silver plated layer

(33): Precious metal plating layer (40): Trivalent chromium plating layer

The present invention relates to a multi-layered trivalent chromium plating film structure that does not cause nickel allergy, and to a nickel-free trivalent chromium plating method for forming the same, forming a sandwich-type triple plating layer, and forming a trivalent chromium plating layer thereon to form a nickel layer. The present invention relates to a multi-layer trivalent chromium plated film structure which does not form a metal, improves adhesion between metal layers, does not cause nickel allergy having excellent corrosion resistance and abrasion resistance, and a nickel-free trivalent chromium plating method for forming the same.

In general, conductors such as metals, synthetic resins, and non-conductors such as ceramics are widely used in general household appliances or various industrial fields, and metal plating is formed on such materials to provide smoothness, gloss, and decorative texture. The way to improve the dignity is widely used.

Recently, the use of heavy metals that are harmful to the human body is restricted or prohibited to protect the global environment and improve the human living environment.In particular, lead, cadmium, Mercury and hexavalent chromium have been banned. In order to cope with this, a technique of using trivalent chromium plating instead of hexavalent chromium has been developed and put into practice, but the trivalent chromium coating tends to be considerably lowered in corrosion resistance compared to the hexavalent chromium coating, so its utilization is It has been applied in part only to nickel plated film having excellent corrosion resistance and abrasion resistance.

However, recent cases of damage to nickel allergy have been reported one after another in many parts of the world, including Northern Europe. Actually, depending on race or race, the reaction to nickel allergy is positive in almost half of the population. The prohibition of is spreading rapidly, and it is urgent to develop a plating method that can replace nickel and hexavalent chromium.

The trivalent chromium plating method has been practically used to replace the hexavalent chromium plating method for many years, but it was only partially used on nickel but was not rapidly spreading. Recently, even the application of nickel plating has been restricted. Even with the use of chromium plating, the use of chromium plating has decreased dramatically despite the excellent properties of chromium.

Correspondingly, various trivalent chromium plating methods that do not use nickel have been developed one after another, but corrosion resistance and abrasion resistance are significantly lower than conventional hexavalent chromium plating methods on nickel, and thus cannot be widely applied.

As a plating method that does not use nickel and chromium, which are conventionally used, ternary alloys using copper-tin-zinc or binary alloys using copper-tin and plating methods using noble metals have been developed. Although it is partially used for various decorative purposes, the corrosion resistance is significantly lower and the wear resistance and mechanical properties are significantly lower than those of hexavalent chromium plating with nickel as a base layer.

In addition, the conventional method as described above does not realize the same decorative effect as the color of the conventional nickel / chromium plating, it may use a plating method with a trivalent chromium as the top layer, but the chemical of the trivalent chromium plating solution Corrosion resistance of the alloy plating layer is rather worse due to the effect is not used as a base layer of trivalent chromium.

In addition, as a means for securing corrosion resistance without using nickel, after forming a base plating layer of copper plating or the copper-tin-zinc alloy plating or copper-tin alloy plating, and the like before performing trivalent chromium plating, Although some attempts have been made to first plate with a noble metal such as, and then trivalent chromium plating thereon, the thin noble metal plating layer has galvanic corrosion on lower metals such as copper, tin, and zinc formed in the underlying plating layer. In addition, it has an adverse effect of increasing, causing a significant decrease in corrosion resistance, has a problem that the appearance appears suspended, and when the thick noble metal plating layer as a base layer of trivalent chromium plating has a problem that greatly increases the manufacturing cost Therefore, it is not economical to apply expensive precious metals such as palladium to sufficient thickness. There were various problems such as can not be more than utilitarian.

The present invention is to solve the above problems, the object is to form a sandwich-type triple plating layer having excellent adhesion between the plating layer and corrosion resistance in the copper or alloy plating layer, thereby forming a trivalent chromium plating layer, excellent without the nickel plating layer A trivalent chromium plating layer having corrosion resistance, abrasion resistance, and mechanical properties is provided as an outermost layer, and a structure of a decorative multilayer plating film using no nickel and a plating method thereof are provided.

Another object of the present invention is to form a nickel plating layer to prevent the nickel allergy due to the nickel plating in advance, and by using the trivalent chromium plating layer that can protect the human body as the outermost layer and decorative multilayer plating without using nickel It is to provide a structure of the coating and a plating method thereof.

It is still another object of the present invention to form a trivalent chromium plating layer stably without a nickel plating layer, and to form a trivalent chromium plating layer having a transparent and beautiful appearance as an outermost layer, and a structure of a decorative multilayer plating film using no nickel and a plating method thereof. To provide.

The present invention is a base plated layer 20 formed of copper or binary / three-membered alloy on the object 10, and formed on the base plated layer, the precious metal strike plating layer 31, the silver plated layer 32, the precious metal The plated layer 33 includes a sandwich type precious metal triple plating layer 30 in which the plating layer 33 is sequentially stacked, and a trivalent chromium plating layer 40 formed on the sandwich type precious metal triple plating layer.

The conductor 10 includes a conductor such as a metal or the like, a polymer plastic material such as ABS or PC, or an insulator such as a ceramic or the like.

The base plating layer 20 is an electroless copper plating layer 21, the electroplated copper plating layer 22 and the alloy plating layer 23 are sequentially laminated, the plating is formed to a thickness of 3 to 20㎛ thickness to give abrasion resistance.

The alloy plating layer 23 is formed of a binary alloy such as copper-tin, copper-zinc, copper-zinc, tin-zinc, or a ternary alloy such as copper-tin-zinc.

The sandwich type precious metal triple plating layer 30 includes a precious metal strike plating layer 31 formed of a platinum group metal or gold, a silver plating layer 32 formed on the precious metal strike plating layer, and a platinum group metal or gold on the silver plating layer. It comprises a noble metal plating layer 33 formed by.

The noble metal strike plating layer 31 is to protect the underlying plating layer 20 when the silver plating layer 32 is formed and to improve adhesion between the silver plating layer and the underlying plating layer, and is strike-plated and has a thickness of about 0.01 to 2 μm. Plated with.

The platinum group metals include ruthenium, rhodium, palladium, osmu, iridium, and platinum, and preferably, palladium (Pd) is used. That is, the noble metal strike plating layer is preferably formed of a palladium or gold strike plating layer.

The silver plating layer 32 is to ensure a high coating force and corrosion resistance, and is plated to a thickness of about 0.1 ~ 10㎛.

The noble metal plating layer 33 is for imparting excellent corrosion resistance, and is plated with a platinum group metal or gold to a thickness of about 0.01 to 2 μm.

As described above, the sandwich-type noble metal triple plating layer 30 including the noble metal strike plating layer 31, the silver plating layer 32, and the noble metal plating layer 33 is a chemical resistant layer having excellent corrosion resistance, and provides adhesion between plating layers.

The trivalent chromium plating layer 40 is formed to be located at the outermost layer, and has a thickness of 0.1 μm or more so that the object is durable by plating and has a transparent and beautiful appearance.

The present invention configured as described above is provided with abrasion resistance by the base plating layer, corrosion resistance and adhesion and abrasion resistance by the sandwich-type triple plating layer, additional wear resistance and decorative properties by the trivalent chromium plating layer formed on the outermost layer.

That is, the present invention comprises the steps of forming a base plating layer on the substrate by copper plating or alloy plating;

Sequentially stacking a noble metal strike plating layer, a silver plating layer, and a noble metal plating layer on the alloy plating layer to form a sandwich type noble metal triple plating layer;

Forming a trivalent chromium plating layer on the sandwich-type noble metal triple plating layer.

That is, the present invention forms a base plating layer on the object, and after laminating the sandwich type precious metal triple plating layer consisting of the noble metal strike plating layer, the silver plating layer and the precious metal plating layer, to form a trivalent chromium plating layer on the triple plating layer. It is.

The forming of the base plating layer may include forming an electroless copper plating layer by electroless copper plating the surface of the object;

Forming an electroplating layer on the electroless plating layer to form gloss and texture by electroplating;

Forming an alloy plating layer of a ternary alloy or a binary alloy on the electroplated copper layer.

At this time, the step of forming the electroless plating layer, the step of forming the electro-copper plating layer (glossy copper plating layer) is to form a smoothness, gloss or possible decorative texture after the usual pre-treatment plating on the subject, The copper plating layer (electroless copper plating layer + electrolytic copper plating layer) formed is formed to a thickness of about 1 ~ 10㎛.

That is, by performing a series of etching, catalyzing, and electroless plating on the surface of the non-conductor such as a polymer plastic material and ceramics and the metal parts, a metal electroconductive layer is formed and ordinary electroplating is performed to impart gloss and texture.

The alloy plating layer forming step may be replaced with copper-tin, copper-zinc, tin-zinc, copper-tin-zinc plating or other possible alloys or metals to form a wear resistant layer having a thickness of about 2 to 20㎛.

That is, the alloy plating layer forming step is a copper-tin, copper-zinc, copper-zinc, tin-zinc, copper-tin-zinc plating or other possible at a current density of 0.1 ~ 6 A / dm 2 at a temperature of 40 ~ 60 ℃ Plating is performed to form about 2-20 μm of copper-tin, copper-zinc, copper-zinc, tin-zinc, copper-tin-zinc plating or other possible alloy plating layers.

Forming the sandwich-type noble metal triple plating layer is a step of forming a noble metal strike plating layer by platinum group metal or gold:

Forming a silver plating layer on the formed precious metal strike plating layer;

Forming a precious metal plating layer by platinum group metal or gold on the silver plating layer.

Forming the noble metal strike plating layer is to improve the adhesion between the metal layers, and to protect the underlying plating layer from the silver plating layer formed thereafter, 0.1 to 1 in a platinum group metal or gold plating solution at a concentration of 0.5 to 10 g / L at room temperature Strike plating is carried out at a current density of A / dm 2 to form a noble metal strike plating layer having a thickness of about 0.01 to 2 μm. At this time, the plating liquid is a liquid of neutral or weak acid, weak alkali acid having a pH of about 6-9.

Adjusting the acidity as described above facilitates washing with water, suppresses the corals of the underlying plating layer which may be generated by the formation of the silver plating layer, and prevents the deterioration of gloss and the appearance of a cloudy appearance after plating.

In addition, the noble metal strike plating layer formed as described above is preferably plated to have a thickness of about 0.01 to 1 μm, most preferably 0.05 μm.

The step of forming the silver plating layer is electroplated in a silver cyanide plating solution of 30 to 200 g / L at room temperature and plated at a current density of 0.5 to 5 A / dm 2 to a thickness of 0.1 to 10 ㎛, preferably 0.5 to 5 ㎛ Most preferably, a gloss silver plating layer having a thickness of 2-3 m is formed.

The silver plated layer formed as described above has a function of tying inherent excellent corrosion resistance, coating power, and pinhole, and serves to prevent infiltration of various corrosion-causing substances into the lower layer coating film, and has a high content of 1 micron / minute or more. It can be plated at the plating speed, so it has good corrosion resistance and good mass production.

As described above, the present invention is to form a noble metal strike plating layer before the silver plating, it is possible to prevent the reduction in adhesion between the metal of the underlying plating layer and the dissolution of the underlying plating layer due to the silver plating solution having high alkalinity and high concentration.

Forming the noble metal plating layer is plated at a current density of 0.1 to 1 A / dm 2 in a noble metal electroplating solution at a concentration of 0.5 to 10 g / L at room temperature to a thickness of 0.01 to 2 μm, preferably a thickness of 0.01 to 1 μm, Preferably, the noble metal plating layer is formed to a thickness of 0.05 μm.

At this time, the noble metal plating layer is a platinum group metal plating layer or gold plating layer, preferably formed of a palladium plating layer or gold plating layer.

In the forming of the trivalent chromium plating layer, a trivalent chromium plating layer having a thickness of 0.1 μm or more is formed by plating at a current density of 5-20 A / dm 2 in a conventional trivalent chromium plating bath. At this time, the thickness of the trivalent chromium plating layer need not be particularly limited, but in consideration of economic efficiency, a trivalent chromium plating layer having a thickness of 0.1 to 3 µm is formed.

The present invention can form a multi-layer plating film having trivalent chromium plating without nickel plating on the subject through each of the above steps.

The plated film prepared by the method of the present invention as described above does not cause corrosion such as white blue, red blue, green blue, yellowing for over 200 hours in the normal salt spraying environment defined by the KS standard, and is given a load of 500 g. The copper plating layer is not revealed even after more than 500 reciprocating abrasion resistance tests, and has the same appearance characteristics as conventional nickel-chromium plating.

Hereinafter, the present invention will be described in detail by way of examples.

Example 1

Electroless copper plating was carried out on a specimen 5 cm long, 5 cm long, and 5 mm thick formed from ABS plastic resin according to the conventional ABS resin plating method, and plated thereon at 1.5 A for 10 minutes to form a normal gloss copper plating layer. After that, ordinary copper-tin-zinc plating was plated at a current of 2 A for 20 minutes to form a 4 micron copper-tin-zinc alloy plating layer, followed by a 2 g / L concentration of palladium ammonium chloride plating solution. After plating for 30 seconds with a current of 0.3 A at to form a paradium plating layer, 85 g / L of cyanide and 190 g / L of cyanide were dissolved, and then, at a concentration of 20 ㎖ / l of silver cyanide as a main varnish for plating, Plating a silver plated layer for 2 minutes with a current of 1.5 A at a temperature of < RTI ID = 0.0 > C, < / RTI > After the usual 3 For 4 minutes in a chrome bath with chloride of 8A current plating to form a trivalent chromium plating layer.

The plating layer thus prepared was formed of a copper 7-micron, a copper-tin-zinc alloy plated layer 8 μm, a palladium 0.05 μm, a silver 1.5 μm, a palladium 0.05 μm, and a chromium 0.8 μm as the outermost multilayer plated layer. .

Through the above process, the test piece including the palladium-silver-palladium sandwich type noble metal triple plating layer and the trivalent chromium plating layer on the outermost layer was tested by several nickel substitute plating methods, and the corrosion resistance and wear resistance were tested. The results are shown in [Table 1].

Example 2

Electroless copper plating was carried out on a specimen 5 cm long, 5 cm long, and 5 mm thick formed from ABS plastic resin according to the conventional ABS resin plating method, and plated thereon at 1.5 A for 10 minutes to form a normal gloss copper plating layer. After that, the conventional copper-tin-zinc plating is plated at a current of 2A for 20 minutes to form a 4 micron copper-tin-zinc alloy plating layer, followed by 0.3A in a 3 g / L conventional strike gold plating solution of gold ions. After plating for 30 seconds with a current of 30 seconds to form a gold plated layer, 852 g / L of cyanide and 1902 g / L of cyanide were dissolved, and the solution was added at a concentration of 20 ml / l of the main polish agent for cyanide plating. After plating for 2 minutes with a current of A to form a silver plated layer, the plated with a current of 0.1 A in a 2 g / L ammonium ammonium chloride plating solution having a concentration of 2 g / L of palladium metal was formed for 2 minutes to form a palladium plated layer. 8 in gchrom chloride bath It plated for 4 minutes by the electric current of A, and formed the trivalent chromium plating layer.

The plated layer thus prepared was formed with a copper multilayer layer of 8 µm, a copper-tin-zinc alloy plating layer 8 µm, a gold 0.05 µm, a silver 1.5 µm, a paradium 0.05 µm, and a chromium 0.8 µm as the outermost layer.

Through the above process, the specimen including the gold-silver-paradium sandwich type noble metal triple plating layer and the trivalent chromium plating layer on the outermost layer was tested by several nickel substitute plating methods, and the corrosion resistance and wear resistance were tested. The results are shown in [Table 1].

Example 3

Electroless copper plating was carried out on a specimen 5 cm long, 5 cm long, and 5 mm thick formed from ABS plastic resin according to the conventional ABS resin plating method, and plated thereon at 1.5 A for 10 minutes to form a normal gloss copper plating layer. After that, the conventional copper-tin-zinc plating is plated at a current of 2A for 20 minutes to form a 4 micron copper-tin-zinc alloy plating layer, followed by 0.3A in a 3 g / L conventional strike gold plating solution of gold ions. After plating for 30 seconds with a current of 30 seconds to form a gold plated layer, 852 g / L of cyanide and 1902 g / L of cyanide were dissolved, and the solution was added at a concentration of 20 ml / l of the main polish agent for cyanide plating. After plating for 2 minutes with a current of A to form a silver plating layer, the plated gold plating layer was formed by plating with a current of 0.1 A for 2 minutes in a flash gold plating solution having a gold ion concentration of 3 g / L, and then forming a gold plating layer. 4 with a current of 8 A at Liver was plated to form a trivalent chromium plating layer.

The plated layer thus prepared was formed with a 7-μm copper, 8-μm copper-tin-zinc alloy plated layer, 0.05 μm of gold, 1.5 μm of silver, 0.05 μm of gold and 0.8 μm of chromium as the outermost layer.

Through the above process, the specimen including the gold-silver-gold sandwich type noble metal triple plating layer and the trivalent chromium plating layer on the outermost layer was tested by several nickel substitute plating methods, and the corrosion resistance and wear resistance were tested. The results are shown in [Table 1].

Table 1

Specimens prepared through the process of Examples 1 to 3, and specimens prepared by some of the conventional nickel allergic plating method (Comparative Example 1: Specimen manufactured by copper / three-membered alloy / trivalent chromium plating) , Comparative Example 2: specimen prepared by copper / three-membered alloy / palladium / chromium plating, Comparative Example 3: specimen prepared by copper / palladium / trivalent chromium plating) In the salt spraying environment sprayed with 5% NaCl solution, the duration of time until white blue, green blue, and red blue occurred was measured, and the sand eraser was loaded with 500 g of load to compare the wear resistance. The number of round trips between the copper plated layer and the copper plated layer was measured by reciprocating the coated film on the specimen, and after 72 hours in a high temperature and high humidity environment with a temperature of 85 ° C and a humidity of 90% to compare the thermal stability between the plated layers. Checkerboard And then drawn to intersect each other at an interval of 1~1.5㎜ knife for phrases in the form, such as gold plating was measured for interlaminar adhesion in a way that abruptly pulled off with transparent tape, 3M Corporation transparent for phrases determine whether the coating delamination.

As shown in Table 1 above, a sandwich-type noble metal three-layer plating layer composed of palladium-silver-palladium, gold-silver-palladium, gold-silver-gold, etc. Sandwich type noble metal triple plating layer having a platinum group plating layer or a gold plating layer on the top and bottom thereof is a plating film having excellent corrosion resistance, abrasion resistance, and thermal stability.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, the present invention is provided with a base plating layer and a sandwich type noble metal triple plating layer, and has corrosion resistance, abrasion resistance, and thermal stability even without using nickel, and after plating, decorative plating having a transparent and beautiful appearance can be performed. Not only can replace the decorative plating using the conventional nickel-chromium plating, it can also prevent the nickel allergy problem that often occurs in electrical, electronic, mechanical and the like.

In addition, the present invention by forming a precious metal straight plating layer of the platinum group or gold between the base plated layer and the silver plated layer, thereby preventing the dissolution of the base layer gold layer that may occur during formation of the silver plated layer, and the adhesion between the base plated layer and the silver plated layer There is an effect to increase.

In addition, the present invention can enable the decorative plating to a variety of parts that have been designed and manufactured to avoid plating, and can prevent a decrease in abrasion resistance, a decrease in adhesion and thermal stability, which are often a problem in painting, vacuum deposition, etc. The decorative part can be manufactured by the plating method which is easy to collect | recover and recycle a resource.

In addition, the plated layer according to the present invention has many effects such that the metal plated layer is not easily peeled off even if used for a long time, and substances that are harmful to the human body or cause environmental pollution are not discharged.

Claims (5)

An underplating layer formed on the subject and having an alloy plating layer of a binary / three-membered alloy; A sandwich type noble metal triple plating layer formed on the base plating layer and having a noble metal strike plating layer, a silver plating layer, and a noble metal plating layer sequentially stacked; A structure of a decorative multilayer plating film having a trivalent chromium plating layer formed on the sandwich type noble metal triple plating layer as an outermost layer and not using nickel. The method of claim 1; The noble metal strike plating layer and the noble metal plating layer of the sandwich-type noble metal triple plating layer is a structure of a decorative multilayer plating film having a trivalent chromium plating layer characterized in that it is formed by platinum group metal or gold and not using nickel. Forming a base plating layer on the subject by copper, binary alloy or ternary alloy; Sequentially stacking a noble metal strike plating layer, a silver plating layer, and a noble metal plating layer on the alloy plating layer to form a sandwich type noble metal triple plating layer; The method of forming a trivalent chromium plating layer on the sandwich-type noble metal triple plating layer as the outermost layer, the decorative multilayer plating film plating method using no nickel. The method of claim 3; The forming of the underlying plating layer may include forming an electroless copper plating layer by electroless copper plating the surface of the object; Forming an electroplated layer on the electroless plating layer to form gloss and texture by electroplating; 3. A method of plating a multi-layered coating film for decoration using a trivalent chromium plating layer as an outermost layer and using no nickel, wherein the alloy plating layer is formed of a ternary alloy or a binary alloy on the electrocopper plating layer. The method of claim 3; Forming the sandwich-type noble metal triple plating layer is a step of forming a noble metal strike plating layer by platinum group metal or gold: Forming a silver plating layer on the formed precious metal strike plating layer; The method of forming a noble metal plating layer by platinum group metal or gold on the silver plating layer as the outermost layer, the decorative multilayer plating film plating method using no nickel.

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