KR100485762B1 - Palladium plating solution - Google Patents

Abstract

Provided is a palladium plating solution in which high purity stable palladium precipitates are obtained without crack crack generation of 5 µm or more, which is excellent in mirror gloss.

Metal soluble at least one selected from 0.1-40.0 g / l, pyridinecarboxylic acid 0.01-10 g / l and / or soluble iron salts, zinc salts, thallium salts, selenium salts and tellurium salts based on the amount of palladium Palladium plating solution containing 0.002-1.0 g / l, pyridinecarboxylic acid amide derivative 0.005-10 g / l, aldehyde benzoic acid derivative and anionic surfactant or amphoteric surfactant 0.001-1.2 g / l Related to.

Description

Palladium Plating Solution {PALLADIUM PLATING SOLUTION}

The present invention relates to a palladium plating solution and in particular to a palladium plating solution for providing a palladium plated coating material without the nickel allergy-occurrence problem of the coating material.

Palladium plating solution has been studied extensively for a long time, and the property of plating precipitation is excellent in light resistance, corrosion resistance, discoloration resistance and abrasion resistance, so it is used in various fields such as coating materials, electrical contacts of electronic parts, connectors, and circuit boards. . In addition, examples using conventional surface treatment techniques include palladium plating, palladium-nickel alloy plating, palladium-cobalt alloy plating, rhodium plating, by coating white rings on annular ornaments such as watch cases, watch bands, eyeglass frames, and necklaces. Platinum plating and silver plating are generally performed.

The rhodium plating is not practical because the unit price is too high, silver plating is susceptible to discoloration by sulfides, and palladium-nickel alloy plating may cause nickel allergy, which is prohibited in Europe. In addition, palladium plating and platinum plating have disadvantages such as cracking easily in the exterior coating because the plating coating has high stress.

In consideration of these defects, sulfuric acid, nitrous acid and its sodium salt and potassium salt are added to reduce the internal stress of the palladium precipitate or to improve the glossiness of the coating (Spec. One (Japanese Patent Application Laid-Open No. 2-43393) has been proposed. However, despite such conventional surface treatment technology, it was not possible to sufficiently solve the problem of crack generation due to the internal stress of the palladium precipitate of the exterior paint or the practical problem of maintaining practically apparent.

In recent years, various palladium-plated coating materials are considerably complicated in shape so that the palladium precipitates involved in processing should be excellent in malleability and ductility, and there should be no cracks when processing appropriate curved portions. Ring-shaped jewelry such as eyeglass frames, necklaces, and earrings require a palladium plating solution capable of plating a high purity and stable exterior coating as platinum plating to prevent the occurrence of nickel allergy.

Accordingly, it is an object of the present invention to provide a palladium plating solution in which a palladium precipitate showing high purity and stable physical properties is obtained.

The inventors of the present invention have made extensive studies to find the above phenomena and obtain a palladium plating solution obtained by forming palladium precipitates which are practical and of high purity on an industrial scale, and as a result, soluble palladium salts, pyridinecarboxylic acid and / or traces of solubles. The palladium plating solution composed of a metal salt, an amide derivative of pyridine carboxylic acid, an anionic surfactant or an amphoteric surfactant has an appropriate deposition rate, excellent stability, and the plating film obtained has a film thickness of 5 µm or more, and an interface gloss. The present invention has been found to be excellent in properties and to obtain a high purity palladium precipitate without crack debris or the like.

Therefore, the present invention provides (1) a soluble palladium salt of 0.1-40.0 g / l based on the amount of palladium, 0.01-10 g / l pyridinecarboxylic acid and / or soluble iron salt, zinc salt, thallium salt, selenium salt and tellurium salt 0.02-1.0 g / l at least one selected from metals, etc., 0.005-10 g / l of amide derivatives of pyridinecarboxylic acid, aldehyde benzoic acid derivatives and anionic surfactants and amphoteric surfactants 0.001-1.2 g / l A palladium plating solution characterized by containing (2) a palladium plating solution as described in (1) above, wherein the soluble palladium salt is at least one selected from palladium chloride, dichlorodiaminepalladium and dichlorotetraaminepalladium, ( 3) In the above (1), the pyridine carbonic acid is at least one selected from nicotinic acid, picolinic acid, isochotinic acid, 2,3-quinoline acid, 2,4-rutidine acid and 2,6-dipicolinic acid. As described (4) soluble iron salts, zinc salts, thallium salts, selenium salts and tellurium salts such as palladium plating solutions, ferric sulfate, ferric ammonium sulfate, zinc sulfate, thallium sulfate, selenic acid, selenic acid, sodium selenite and Palladium plating solution as described in (1) above, wherein the amide derivative of pyridinecarboxylic acid is selected from nicotinamide, picolinamide, isicotinic acid amide and nicotinic acid amide, characterized in that it is at least one selected from potassium selenite. Palladium plating solution, (6) aldehyde benzoic acid derivatives as described in (1) above, characterized in that at least one is p-phthalaldehyde, o-phthalaldehyde, p-phthalaldehyde acid, m-phthalaldehyde, iso- Palladium plating solution as described in (1), (7) anionic surfactant or amphoteric, characterized in that it is at least one selected from phthalaldehyde acid and aldehyde ammonium. The surfactants are dodecylamine acetate, cetylpyridinium promide, sulfosuccinic di-2-ethylhexyl sodium, sorbitan monopalmitate, polyoxyethylene stearate, sorbitan monostearate, dimethyl alkyl betaine, dodecyl trimethyl Palladium plating solution as described in (1) above, characterized in that at least one selected from ammonium chloride and polyoxyethylene sorbitan monopalmitate, (8) conductive salt of palladium plating solution as ammonium nitrate, ammonium sulfate, ammonium chloride, Provided is a palladium plating solution as described in (1) above, which is at least one selected from ammonium sulfamate, boric acid, ammonium borate, potassium nitrate, potassium sulfate, potassium chloride, and potassium sulfamate.

Hereinafter, the present invention will be described in detail again. Examples of the soluble palladium salt used in the present invention include palladium chloride, dichlorodiamine palladium and dichlorodiamine palladium, dichlorotetraamine palladium and the like. Here, a salt can also be used 1 type and in combination or 2 or more types. The concentration of the soluble palladium salt 읫 in the palladium plating solution is preferably in the range of 1.0-40.0 g / l based on the amount of palladium. At a concentration of 1.0 g / l or less, it is not preferable because the deposition rate of the plating film is lowered. On the other hand, even if it is 40.0 g / l or more, the deposition rate does not increase further.

In addition, examples of the pyridinecarboxylic acid used in the present invention include nicotinic acid, picolinic acid, isnicotinic acid, 2,3-quinoline acid, 2,4-rutidine acid, 2,6-dipicolinic acid, and the like. The said pyridine carboxylic acid can also use together 1 type (s) or 2 or more types. The concentration of pyridine carboxylic acid in the palladium plating solution is preferably 0.01-20.0 g / l, preferably 1.0 g / l-10.0 g / l. Or, since the glossiness is not further improved at 20.0 g / l, it is not practical.

In the present invention, in order to lower the internal stress of the palladium precipitates, soluble metal salts are used in combination with the pyridine carboxylic acid or soluble metal salts are added instead of pyridine carboxylic acid. Examples of the soluble metal salts include soluble iron salts, zinc salts, thallium salts, selenium salts and tellurium salts. Etc. Specifically, there are iron sulfate, ferric ammonium sulfate, zinc sulfate, thallium sulfate, thallium acetate, selenic acid, selenic acid, sodium selenite and potassium selenite. The said soluble metal salt can be used 1 type or in combination or 2 or more types. The amount of such soluble metal salt used is 0.002-1.0 g / l, preferably 0.005-0.7 g / l in terms of metal. If it is 0.001 g / l or less, there is no effect of lowering the internal stress of the palladium precipitate, and if it is more than 1.0 g / l, the internal stress of the palladium precipitate does not increase further, so it is not practical.

Next, as an amide derivative of pyridine carboxylic acid using this invention, nicotinamide, picolinamide, isonicotinic acid amide, nicotinic acid amide, etc. are mentioned, for example. The amide derivative of pyridinecarboxylic acid can be used 1 type or in combination or 2 or more types. The concentration of the amide derivative of pyridinecarboxylic acid in the palladium plating solution is preferably 0.002-20.0 g / l, preferably 0.005-10.0 g / l. If it is 0.002 g / l or less, it is not practical to shape glossiness, and even if it exceeds 20.0 g / l, glossiness will not improve further, and it is not practical. In addition, as the aldehyde benzoic acid used in the present invention, for example, p-phthaloaldehyde, o-phthaloaldehyde, o-phthaloaldehyde acid, p-phthaloaldehyde acid, m-phthaloaldehyde, iso-aldehyde and aldehyde Ammonium and the like. The aldehyde benzoic acid derivatives described above can be used alone or in combination of two or more thereof. The use concentration of the aldehyde benzoic acid derivative in the palladium plating solution is 0.002-20.0 g / l, preferably 0.005-10.0 g / l. If it is 0.002 g / l or less, there is no effect which improves glossiness, and even if it exceeds 20.0 g / l, glossiness will not become more large and it is not practical.

In addition, the anionic surfactant or the amphoteric surfactant used in the present invention is for preventing the occurrence of fitting (dentation phenomenon), and especially has the greatest effect on the complex shape. Specifically, dodecylamine acetate, cetylpyridinium bromide, sulfoxide hexanedi-2-ethylhexyl sodium, sorbitan monopalumitate, polyoxyethylene stearate, sorbitan monostearate, dimethyl alkyl betaine, dodecyl Trimethylammonium chloride, polyoxyethyl sorbitan monopalumitate, and the like. The anionic surfactant or amphoteric surfactant can be used alone or in combination of two or more thereof. The use concentration of the anionic surfactant or the amphoteric surfactant in the palladium plating solution is 0.001-1.2 g / l. If it is 0.001 g / l or less, it is not enough to prevent a fitting generation, and even if it uses 1.2 g / l or more, the prevention effect of fitting generation does not improve, and it is not practical.

Alternatively, in the present invention, in order to provide conductivity and buffering effect to the plating solution, potassium dihydrogen phosphate, ammonium hydrogen phosphate, ammonium chloride, ammonium sulfate, boric acid, ammonium borate, ammonium sulfate, ammonium sulfamate, potassium nitrate, potassium sulfate , Potassium chloride and potassium sulfamate are added. These additives can be used 1 type or in combination or 2 or more types. In the plating solution of the present invention, the concentration of the conductive salt is 15.0-30.0 g / l. If it is 15.0 g / l or less, the electroconductivity of plating will worsen, and if it is 300.0 g / l or more, the specific gravity of a plating liquid will become large and cloudy, fog, burning, etc. generate | occur | produce in a palladium precipitate, and are unpreferable.

The plating liquid of the present invention is used in the range of pH7-12, preferably pH7.5-9.5. A good plating film can be formed in this pH range. The pH adjustment of the plating liquid is performed with acids such as hydrochloric acid and sulfuric acid or alkaline substances such as sodium hydroxide, potassium hydroxide and aqueous ammonia. The plating liquid of the present invention can be plated at a temperature of 30-55 ° C., and a good film having a smooth luster is obtained especially at a liquid temperature of 40-55 ° C. In addition, as the liquid temperature is higher, the deposition rate of the plated film tends to be faster, and an arbitrary deposition rate can be achieved by setting an appropriate temperature within the above temperature range. Furthermore, in the plating solution of the present invention, the deposition rate of the plating film depends on the temperature of the plating solution or the palladium concentration, so that the deposition rate of the plating film can be easily adjusted by appropriately setting the palladium concentration, so that the thickness of the plating film can be easily controlled. .

The current density in the case of plating is 0.3-1.2 A / dm ² .

Example

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

The composition of plating solution

Dichlorodiaminepalladium ........................ 10 g / l

(Based on Pd metal amount)

Atelluric Acid (Based on Te Metal Amount) ........... 0.05g / l

Ammonium Chloride ............... 80 g / l

Ammonium Hydrogen Phosphate ......................... 20 g / l

Nicotinic Acid Amide .................................... 0.8g / l

Sulfoxide hexanedi-2-ethylhexyl sodium ......... 0.01 g / l

The plating solution was adjusted to pH8.3 with ammonia water, the bath temperature was 45 ° C., and the current density was 1.0 A / dm ² . A glossy palladium plating material having a thickness of 7 μm was obtained. The crack crack was not confirmed as a result of performing an ammonia aeration test (12 hours at room temperature) on the obtained palladium plating material.

Example 2

The composition of plating solution

Dichlorodiaminepalladium ........................ 10 g / l

(Based on Pd metal amount)

Ammonium Chloride ......................................... 90 g / l

Boric acid ......................................... 10 g / l

Nicotinic Acid Amide ..................... 1.0g / l

2,6-dipicolinic acid ..................... 0.5 g / l

Dodecyltrimethylammonium chloride ................. 0.1g / l

The plating solution was adjusted to pH8.3 with ammonia water, and the average film was obtained by immersing a 25 x 35 mm brass copper plate subjected to nickel plating for 30 minutes at a bath temperature of 42 ° C. and a current density of 1.0 A / dm ² . A glossy palladium plating material having a thickness of 7 μm was obtained. The crack crack was not confirmed as a result of performing an ammonia aeration test (12 hours at room temperature) on the obtained palladium plating material.

Example 3

The composition of plating solution

Dichlorodiaminepalladium ........................ 10 g / l

(Based on Pd metal amount)

Ferric Ammonium Sulfate ................................. 0.1g / l

(Based on the amount of Fe metal)

Ammonium Chloride ......................................... 90 g / l

Boric acid ......................................... 10 g / l

Nicotinic Acid Amide ..................... 1.0g / l

2,6-dipicolinic acid ..................... 0.5 g / l

Dodecyltrimethylammonium chloride ................. 0.1g / l

The plating solution was adjusted to pH8.3 with ammonia water, and the average film was obtained by immersing a 25 x 35 mm brass copper plate subjected to nickel plating for 30 minutes at a bath temperature of 42 ° C. and a current density of 1.0 A / dm ² . A glossy palladium plating material having a thickness of 7 μm was obtained. The crack crack was not confirmed as a result of performing an ammonia aeration test (12 hours at room temperature) on the obtained palladium plating material.

Example 4

The composition of plating solution

Dichlorodiaminepalladium ........................ 10 g / l

(Based on Pd metal amount)

Ammonium Sulfate ......................... 60g / l

Boric acid ......................................... 20 g / l

Ammonium Hydrogen Phosphate ......................... 30 g / l

Nicotinic Acid ..................... 1.0g / l

Picolinamide ................................... 0.5 g / l

Sulfoxide hexane di-2-ethylhexyl sodium ..................... 0.1 g / l

The plating solution was adjusted to pH 8.2 with ammonia water, the bath temperature was 50 ° C., the current density was 1.0 A / dm ² , and the average membrane was obtained by first depositing a 25 × 35 mm brass copper plate subjected to nickel plating for 30 minutes. A glossy palladium plating material having a thickness of 7 μm was obtained. The crack crack was not confirmed as a result of performing an ammonia aeration test (12 hours at room temperature) on the obtained palladium plating material. In addition, there was no discoloration as a result of performing an artificial perspiration deposition test (48 hours at room temperature) on the palladium plated material.

Example 5

The composition of plating solution

Dichlorodiaminepalladium ........................ 10 g / l

(Based on Pd metal amount)

Thallium Sulfate ......................................... 0.035 g / l

(Based on the amount of Tl metal)

Ammonium Sulfate ......................... 60g / l

Boric acid ......................................... 20 g / l

Ammonium Hydrogen Phosphate ......................... 30 g / l

Nicotinic Acid ..................... 1.0g / l

Picolinamide ................................... 0.5 g / l

Sulfoxide hexane di-2-ethylhexyl sodium ..................... 0.1 g / l

The plating solution was adjusted to pH 8.2 with ammonia water, the bath temperature was 50 ° C., the current density was 1.0 A / dm ² , and the average membrane was obtained by first depositing a 25 × 35 mm brass copper plate subjected to nickel plating for 30 minutes. A glossy palladium plating material having a thickness of 7 μm was obtained. The crack crack was not confirmed as a result of performing an ammonia aeration test (12 hours at room temperature) on the obtained palladium plating material. In addition, there was no discoloration as a result of performing an artificial perspiration deposition test (48 hours at room temperature) on the palladium plated material.

Example 6

The composition of plating solution

Dichlorodiaminepalladium ........................ 10 g / l

(Based on Pd metal amount)

Ammonium Chloride ......................................... 40 g / l

Ammonium Sulfate ......................... 20g / l

Nicotinic acid ......................................... 0.5 g / l

Isonicotinic acid amide ........................ 0.2g / l

Sulfoxide hexane di-2-ethylhexyl sodium ..................... 0.1 g / l

The plating solution was adjusted to pH 8.5 with ammonia water, a bath temperature of 50 ° C., and a current density of 1.0 A / dm ^{2. The} average film was obtained by depositing a 25 × 35 mm brass copper plate subjected to nickel plating for 30 minutes. A glossy palladium plating material having a thickness of 7 μm was obtained. The crack crack was not confirmed as a result of performing an ammonia aeration test (12 hours at room temperature) on the obtained palladium plating material.

Comparative Example 1

In the palladium plating solution of Example 1, plating was carried out according to the same plating conditions as in Example 1, except that atelium acid and nicotinic acid amide were used, but instead, a palladium plating solution having a composition in which EDTA was added in an amount of 1.0 g / l. It was. As a result of performing an ammonia aeration test on the obtained palladium plating material, crack cracking occurred in 6 hours at room temperature.

Comparative Example 2

Plating was carried out in accordance with the same plating conditions as those in Example 2, using a palladium plating solution of a composition excluding nicotinamide from the palladium plating solution of Example 2. The palladium plating obtained was stained and not glossy.

Comparative Example 3

Except for ferric ammonium sulfate and nicotinamide in the palladium plating solution of Example 3, plating was carried out according to the same plating conditions as in Example 3 using a palladium plating solution of which composition was added with EDTA in an amount of 1.0 g / l. It was done. An ammonia aeration test was carried out on the obtained palladium plating material, and crack cracking occurred in 6 hours at room temperature.

Comparative Example 4

Plating was carried out in accordance with the same plating conditions as those in Example 6, using a palladium plating solution of a composition excluding nicotinic acid from the palladium plating solution of Example 6. The palladium plating obtained was stained and not glossy.

As described above, the palladium plating solution of the present invention has extremely good storage stability, excellent workability and good working environment. In addition, the deposition rate depends on the palladium concentration and the ambient temperature, it is easy to control the thickness of the plating film. The plating film obtained by the plating liquid of the present invention has a thickness of 5 µm or more and has glossiness, low stress, no crack cracking, excellent malleability and ductility, and beautiful white mirror surface gloss. In addition, this plating film does not generate a crack crack even by ammonia aeration test for 12 hours at room temperature. In addition, an excellent palladium coating which does not cause discoloration can be obtained by a test in which all or half of the deposition treatment is performed under a state of artificial sweating for 48 hours.

Claims (8)

Soluble palladium salt is 0.1-40.0 g / l based on the amount of palladium, 0.01-10 g / l pyridinecarboxylic acid, 0.005-10 g / l amide derivative of pyridinecarboxylic acid and 0.001-1.2 g / anionic or amphoteric surfactant Palladium plating solution containing l, Palladium is further contained by at least one selected from the group consisting of soluble iron salts, zinc salts, thallium salts, selenium salts and tellurium salts in an amount of metal in terms of 0.002-1.0 g / l and an aldehyde benzoic acid derivative 0.002-20.0 g / l. A palladium plating solution characterized by reducing the internal stress of the precipitate and improving gloss. The method of claim 1, The soluble palladium salt is a palladium plating solution, characterized in that at least one selected from palladium chloride, dichlorodiamine palladium and dichlorotetraamine palladium. The method of claim 1, The pyridine carbonic acid is a palladium plating solution, characterized in that at least one selected from nicotinic acid, picolinic acid, isnicotinic acid, 2,3-quinolinic acid, 2,4-rutidinic acid and 2,6-dipicolinic acid. The method of claim 1, The soluble iron salts, zinc salts, thallium salts, selenium salts and tellurium salts include iron sulfate, ferric ammonium sulfate, zinc sulfate, thallium sulfate, thallium acetate, selenic acid, selenic acid, sodium selenite and potassium selenite. Palladium plating solution, characterized in that at least one selected from. The method of claim 1, The amide derivative of the pyridine carboxylic acid is at least one selected from nicotinamide, picolinamide, isnicotinic acid amide and nicotinic acid amide. The method of claim 1, The aldehyde benzoic acid derivatives are at least one selected from p-phthalaldehyde, o-phthalaldehyde, o-phthalaldehyde acid, p-phthalaldehyde acid, m-phthalaldehyde, iso-phthalaldehyde acid and aldehyde ammonium. Palladium plating solution. The method of claim 1, The anionic surfactant or amphoteric surfactant is dodecylamine acetate, cetylpyridinium bromide, sulfosuccinicdi-2-ethylhexyl sodium, sorbitan monopalmitate, polyoxyethylene stearate, sorbitan monostearate, dimethylalkyl A palladium plating solution, characterized in that at least one selected from betaine, dodecyltrimethylammonium chloride and polyoxyethylene sorbitan monopalmitate. The method of claim 1, The palladium plating solution is at least one selected from ammonium nitrate, ammonium sulfate, ammonium chloride, ammonium sulfamate, boric acid, ammonium borate, potassium nitrate, potassium sulfate, potassium chloride and potassium sulfamate as conductive salts.