JP2805692B2 - Method for producing tetraammine palladium dihydroxide - Google Patents

Description

The present invention relates to a method for producing tetraammine palladium dihydroxide (hereinafter referred to as “TAPDH”).

(Prior art and its problems) Conventionally, as a method for producing TAPDH, silver oxide was added to a tetraamminepalladium dichloride solution to precipitate chloride ions into silver chloride, which was separated by filtration to obtain a TAPDH solution. Since the reaction with chlorine ions does not easily react in an equivalent amount, it is difficult to determine the amount of added silver oxide, and there is a disadvantage that the added silver remains and is mixed.

(Object of the Invention) The present invention has been made in order to solve the above-mentioned drawbacks of the conventional method, and by exchanging chloride ions and hydroxide ions by contacting an anion exchange resin with a tetraammine palladium dichloride solution, Low in impurities
It is an object to provide a method for producing a TAPDH solution.

(Means for Solving the Problems) The present invention relates to a method for producing tetraammine palladium dihydroxide, which comprises contacting a tetraammine palladium dichloride solution with an anion exchange resin. In which the amount of the anion exchange resin to be contacted is twice or more the theoretical exchange amount.

 Hereinafter, details of the present invention will be described.

The preparation method of the tetraammine palladium dichloride solution is a dichlorodiammine palladium crystal (Pd (NH ₃ ) ₂ Cl
₂ ) Add ammonia water to the mixture and heat it with stirring. Alternatively, add excess ammonia water to the palladium chloride solution to obtain [Pd (NH ₃ ) ₄ ] [PdCl ₄ ], and further heat the mixture to obtain tetraammine palladium dichloride. A solution can be prepared.

The anion exchange resin is preferably a strong base anion exchange resin, for example, Mitsubishi Chemical Industries Diaion SA10
A or Diaion SA12A.

Before contacting the prepared tetraammine palladium dichloride solution with the anion exchange resin, the method of keeping the anion exchange resin in the OH ion type is, for example, to fill the column with one anion exchange resin and to prepare a column containing about 5% of the anion exchange resin. It is necessary to pass sodium hydroxide solution 3 overnight at a space velocity SV = 2, and then pass pure water also at SV = 2 until the pH of the effluent becomes 7.

In particular, passing pure water to pH = 7 includes removal of sodium ions.

Next, the method of contacting the prepared tetraammine palladium dichloride solution with the OH ion type anion exchange resin may be, for example, mixing in a beaker and stirring and contacting, but such as the operation of converting to the OH ion type. The method of passing a prepared tetraamminepalladium dichloride solution through an anion exchange resin layer packed in a column is simple and can save labor such as separation, and is more preferable for performing a continuous operation.

Further, the liquid passing speed SV may be 0.1 to 0.5, and more preferably, SV is 0.2.

The reason why the amount of the anion exchange resin is twice or more the theoretical amount of the anion exchange is due to the relationship with the anion exchange equilibrium, and the exchange of chloride ions and OH ions of the palladium compound is completely performed. It is an indispensable point to make.

Therefore, the concentration of the prepared tetraammine palladium dichloride solution to be passed through the anion exchange resin is not particularly limited, but a concentration operation is required for a thin solution, and a crystal is generated at the time of passage for a concentrated solution. There is a possibility, and it is preferable to adjust the amount to 40 g / -100 g /.

By the above method, TAPD with extremely low impurity contamination
An H solution can be produced.

Hereinafter, examples according to the present invention will be described, but the examples do not limit the present invention.

(Example 1) 100 g of dichlorodiamine palladium was placed in a 2 beaker, 500 ml of pure water was added, 500 ml of 28% ammonia water was added, and the mixture was heated and dissolved at 80 ° C in a hot water bath with stirring to obtain a tetraamine palladium dichloride solution. Prepared.

Next, the solution was cooled to room temperature, and a layer filled with a 50 mm diameter glass column filled with a strong base anion exchange resin (manufactured by Mitsubishi Kasei Kogyo Co., Ltd., Diaion SA10A) 3 previously converted into an OH ion form was filled with space. The solution was passed at a speed SV = 0.2.

After passing the solution, pure water SV = 0.2 for the anion exchange resin layer
And washed by extrusion to obtain a TAPDH solution 10.5.

A 2 ml aliquot of the TAPDH solution was subjected to potentiometric titration with 1 / 10N hydrochloric acid. From the amount of hydrochloric acid required for the titration, it was confirmed that OH ions were almost 2 mol per 1 mol of palladium, and it was TAPDH.

Note that the chloride ion concentration in the solution was 21 mg /.

Example 2 28% aqueous ammonia was added to 100 ml of a palladium chloride solution (Pd 100 g /), and the solution was heated to 80 ° C. while stirring and maintained for 30 minutes to prepare a transparent tetraammine palladium dichloride solution.

Then, the solution was cooled to room temperature, and a layer filled with 100 ml of a glass column having a diameter of 10 mm was filled with 100 ml of a strong base anion exchange resin (manufactured by Mitsubishi Chemical Corporation: Diaion SA10A) previously converted to OH ion form. The solution was passed at a speed SV = 0.2.

After passing the solution, pure water SV = 0.2 for the anion exchange resin layer
And extruded and washed to obtain a TAPDH solution 0.4.

A 2 ml aliquot of the TAPDH solution was subjected to potentiometric titration with 1 / 10N hydrochloric acid. From the amount of hydrochloric acid required for the titration, it was confirmed that OH ions were almost 2 mol per 1 mol of palladium, and it was TAPDH.

Note that the chloride ion concentration in the solution was 10 mg /.

(Conventional example) Silver oxide powder was added to the same solution as the tetraammine palladium dichloride solution used in Example 1 under stirring, and when it was confirmed that white precipitation of silver chloride did not occur, the addition of silver oxide was stopped, and the mixture was separated by filtration. And washed with pure water.

Most of the separated filtrate was a TAPDH solution, but the silver in the solution was 100 mg / content.

(Effect of the Invention) As is clear from the above description, in the conventional method, silver oxide was added, and the precipitate of silver chloride was separated by filtration to produce a TAPDH solution. Although the solution contained many impurities, according to the method of the present invention, the amount of chloride ions in the solution can be extremely reduced, and silver oxide is not used. It can be manufactured.

Claims (3)

(57) [Claims] 1. A process for producing tetraamminepalladium dihydrooxide, comprising contacting a tetraamminepalladium dichloride solution with an anion exchange resin. 2. The method according to claim 1, wherein the anion exchange resin is treated in advance as an OH ion type. 3. The method according to claim 1, wherein the amount of the anion exchange resin to be contacted is at least twice the theoretical exchange amount.