RU2246480C1 - Method for preparing copper (ii) acetate monohydrate - Google Patents

Abstract

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing copper (II) acetate monohydrate that represents organic carboxylic acid salt. Copper (II) acetate monohydrate is prepared by crystallization from solution obtained by mixing acetic acid, alkaline metal acetates or ammonium with copper-containing spent solution used in etching printing boards. Method provides reducing cost of the proposed method for preparing copper (II) acetate monohydrate, retaining purity of product with simultaneous utilization of toxic waste in electronic engineering manufacture - the spent solution in etching printing boards. Also, invention provides reducing material consumptions in preparing copper (II) acetate monohydrate, expanding assortment of materials used for its preparing and utilization of toxic waste in electronic engineering manufacture. Product obtained by the proposed method can be used as pigment, fungicide and copper microfertilizer in agriculture, as catalyst in processes of polymerization, as a stabilizing agent of artificial fibers, for preparing galvanic solutions and preparing other copper compounds.

EFFECT: improved preparing method.

14 cl, 5 ex

Description

The invention relates to the field of chemical technology of organic compounds, in particular to a method for producing copper (II) acetate monohydrate, which can be used as a pigment, fungicide and copper microfertilizer in agriculture, a catalyst for the polymerization of organic substances, a stabilizer of artificial fibers, for the preparation of galvanic solutions to obtain other copper compounds.

It is known that monoclinic crystals of copper (II) acetate monohydrate of the composition Cu (CH ₃ COO) ₂ · H ₂ O (De Meester P., Fletcher SR, Scapski AC // Joumal of Chemical Society are isolated from an aqueous solution of copper (II) acetate. Dalton Transactions, 1973, V.23, P.2575. Brown GM, Chidambaram R. // Acta Crystallographica, 1973, V.B29, No. 12, P.2393).

Known methods for producing copper (II) acetate monohydrate, including the preparation of an aqueous solution containing copper (II) and acetate, as a result of exchange reactions between calcium, barium or lead acetates and copper (II) sulfate, followed by separation of precipitation of calcium, barium or lead sulfates from solutions by filtration, concentration of the filtrate and crystallization of the product (Manual on preparative inorganic chemistry (under the editorship of Brauer G.) - M .: Izn. T.2. - M .: Mir, 1972, S.718). These methods are based on the reactions:

CuSO ₄ + Ca (CH ₃ COO) ₂ + 2H ₂ O → Cu (CH ₃ COO) ₂ + CaSO ₄ · 2H ₂ O ↓

CuSO ₄ + Ва (СН ₃ СОО) ₂ → Сu (СН ₃ СОО) ₂ + BaSO ₄ ↓

CuSO ₄ + Pb (CH ₃ COO) ₂ → Cu (CH ₃ COO) ₂ + PbSO ₄ ↓.

The disadvantage of these methods is the need for additional costs for filtering and evaporating the solution, as well as costs for the reagent - copper (II) sulfate.

Known methods for producing copper (II) acetate monohydrate, consisting in the preparation of an aqueous solution containing copper (II) and acetate by dissolving metallic copper (in the presence of atmospheric oxygen), copper (II) oxide, copper (II) hydroxide, basic copper carbonate (II), basic copper (II) acetate in acetic acid, followed by a concentrated solution by evaporation and crystallization of the product (Guide to Preparative Inorganic Chemistry (edited by Brauer G.) - M .: Izn. Foreign lit., 1956 P. 472. Ripan R., Chetyanu I. Inorganic chemistry. - M .: Mir, 1972, p. 718. Remy G. Course of inorganic chemistry. Vol. 2. - M .: Mir, 1974, p. 387). These methods are based on the following reactions:

2Cu + 4CH ₃ COOH + O ₂ → 2Cu (CH ₃ COO) ₂ · N ₂ O

CuO + 2CH ₃ COOH → Cu (CH ₃ COO) ₂ · H ₂ O

Cu (OH) ₂ + 2CH ₃ COOH → Cu (CH ₃ COO) ₂ · H ₂ O + H ₂ O

Cu (OH) ₂ · CuCO ₃ + 4CH ₃ COOH → 2Cu (CH ₃ COO) ₂ · H ₂ O + CO ₂ ↑ + H ₂ O

хСu (ОН) ₂ · уСu (СН ₃ СОО) ₂ · zН ₂ O + 2хСН ₃ СОО →

(x + y) Cu (CH ₃ COO) ₂ H ₂ O + (z + xy) H ₂ O

The disadvantage of these methods is the need for additional costs for heating the solution and costs for copper-containing reagents.

Closest to the claimed method is a method for producing copper (II) acetate monohydrate, which includes preparing a reaction solution containing copper (II) and acetate, crystallizing the product, separating crystals from the solution and drying them (Karjakin Yu.V., Angelov II Pure chemicals. - M.: Chemistry, 1974, P.239). The reaction solution in the prototype is prepared by adding basic copper (II) carbonate in an 11% aqueous solution of acetic acid when heated to 60 ° C, followed by concentration by evaporation to 1/3 of the original volume. Crystallization of the product is carried out while cooling the solution. The crystals were separated from the solution by filtration under reduced pressure and dried at room temperature. The prototype method allows to obtain pure copper (II) acetate monohydrate with a yield of 80-88%. The disadvantage of this method is the need for additional costs for heating and evaporation of the reaction solution and the cost of the reagent is the basic carbonate of copper (II).

When creating the invention, the task was to reduce material costs for producing copper (II) acetate monohydrate and to utilize toxic production waste.

This is achieved by the fact that the method of producing copper (II) acetate monohydrate involves preparing a reaction solution containing copper (II) and acetate, crystallizing the product, separating the crystals from the solution, and drying them. New in this method is that the reaction solution is prepared by mixing the reagent, which is the source of acetate, and the waste of electronic production - the spent solution etching the printed circuit boards, and in the reaction solution, the pH is set to 0.5 to 7.0 and the molar ratio of copper (II ): acetate equal to 1.0: (2.0-25.0). As a used solution for etching printed circuit boards, it is desirable to use a solution containing copper (II), ammonia, ammonium chloride, or a solution containing copper (II), ammonia, ammonium chloride, ammonium carbonate, or a solution containing copper (II), ammonia, ammonium sulfate, or a solution containing copper (II), ammonia, ammonium sulfate, ammonium peroxodisulfate, and acetic acid or acetic and hydrochloric acids as a source of acetate. It is also desirable to use a solution containing copper (II), hydrochloric acid, or a solution containing copper (II), hydrochloric acid, ammonium chloride, or a solution containing copper (II), sulfuric acid, ammonium peroxodisulfate as a used solution for etching printed circuit boards and as a reagent, which is the source of acetate, - acetic acid and sodium hydroxide, or acetic acid and potassium hydroxide, or acetic acid and ammonium hydroxide, or sodium acetate, or potassium acetate, or ammonium acetate. As a reagent, which is the source of acetate, it is desirable to use a waste product containing acetic acid or sodium acetate, or potassium acetate, or ammonium acetate. Crystallization of the product is preferably carried out at a temperature of from -5 to 60 ° C.

The method for producing copper (II) acetate monohydrate consists in preparing the reaction solution by adding acetic acid to the spent copper-ammonia etching solution of printed circuit boards or sodium, potassium, ammonium acetate to the spent acid solution of etching printed circuit boards, adjusting (if necessary) the pH of the reaction solution separation of copper (II) acetate monohydrate in the form of a crystalline precipitate, separation of the precipitate from the solution by known methods, washing (if necessary) of the precipitate with a solvent, Ivan sediment in the air.

Used solutions for etching printed circuit boards (copper-ammonia based on copper (II), ammonia, ammonium chloride, copper-base solutions based on copper (II), ammonia, ammonium chloride, ammonium carbonate, copper sulfate based on copper (II ), ammonia, ammonium sulfate, peroxodisulfate based on copper (II), ammonium sulfate, ammonium peroxodisulfate, ammonia or sulfuric acid, acid based on copper (II), hydrochloric acid or copper (II), hydrochloric acid, ammonium chloride) are toxic waste of electronic production and are subject to neutralization (Fedu ova AA., Ustinov Yu.A., Kotov EP, Shustov VP, Yavich ER Technology of multilayer printed circuit boards. - M .: Radio and communications, 1990, P.186), which requires significant material costs. Acetic acid GOST 61-75, sodium hydroxide GOST 4328-77, sodium acetate GOST 199-78, ammonium acetate GOST 3117-78 are produced by the chemical industry and have a low cost. In addition, waste from the production of food and reactive acetic acid and alkali metal or ammonium acetates can be used to produce copper (II) acetate monohydrate. When these reagents are added to the spent etching solutions of the printed circuit boards, the following chemical reactions proceed:

[Cu (NH ₃ ) ₄ ] Cl ₂ + 2CH ₃ COOH + 2CHl + H ₂ O → Cu (CH ₃ COO) ₂ · H ₂ O + 4NH ₄ Cl

[Cu (NH ₃ ) ₄ ] SO ₄ + 4CH ₃ COOH + H ₂ O → Cu (CH ₃ COO) ₂ · H ₂ O + (NH ₄ ) ₂ SO ₄ + 2CH ₃ COOH

(NH ₄ ) ₂ [CuCl ₄ ] + 2CH ₃ COOH + 2NaOH → Cu (CH ₃ COO) ₂ · H ₂ O + 2NH ₄ Cl + 2NaCl + H ₂ O

H ₂ [CuCl ₄ ] + 4CH ₃ COONa + H ₂ O → Cu (CH ₃ COO) ₂ · H ₂ O + 2CH ₃ COOH + 4NaCl.

As a result, crystalline copper (II) acetate monohydrate is isolated from the reaction solution. The proposed method allows to obtain copper (II) acetate monohydrate using available and inexpensive reagents - acetic acid, sodium hydroxide, sodium acetate, ammonium acetate without the use of copper-containing reagents and at the same time to utilize the waste from electronic and chemical industries.

To obtain copper (II) acetate monohydrate, it is desirable to use spent etching solutions of printed circuit boards containing copper (II), ammonia, ammonium chloride, ammonium sulfate, hydrochloric acid, sulfuric acid, which have the composition, for example:

Copper (II) (in the form of an ammonia complex) 50-120 g / l

Ammonia 50-100 g / l

Ammonium chloride 50-150 g / l

or

Copper (II) (in the form of an ammonia complex) 50-120 g / l

Ammonia 30-100 g / l

Ammonium chloride 5-50 g / l

Ammonium carbonate 20-400 g / l,

or

Copper (II) (in the form of an ammonia complex) 60-100 g / l

Ammonia 80-130 g / l

Ammonium sulfate 30-100 g / l,

or

Copper (II) (in the form of a chlorocomplex) 80-140 g / l

Hydrogen chloride 10-30 g / l

Ammonium chloride 50-150 g / l.

To obtain copper (II) acetate monohydrate, it is desirable to set the optimum pH value in the reaction solution. Copper (II) acetate monohydrate is soluble in water, and its solubility increases in the presence of strong acids (sulfuric, hydrochloric, nitric), therefore, at pH less than 0.5, the yield of copper (II) acetate monohydrate is significantly reduced. According to experimental data, at pH from 7.0 to 9.0, copper (II) acetate monohydrate is contaminated with basic salts of copper (II); at pH greater than 9.0, copper (II) acetate monohydrate does not drop out of solution, since copper (II) in solution is bound to the complex [Cu (NH ₃ ) ₄ ] ²⁺ . Therefore, to obtain pure copper (II) acetate monohydrate in high yield, it is desirable to prepare a reaction solution with a pH from 0.5 to 7.0.

To obtain pure copper (II) acetate monohydrate in high yield, it is desirable to prepare a reaction solution containing copper (II) and acetate in the optimal molar ratio. According to experimental data, a mixture of copper (II) acetate monohydrate with basic copper (II) salts falls out of solutions in which 1.0 mol of copper (II) accounts for less than 2.0 mol of acetate. From solutions in which 1.0 mol of copper (II) accounts for 2.0 or more mol of acetate, pure copper (II) acetate monohydrate with a high yield of copper (II) falls out, but the yield of the product with acetate with a change in the molar ratio of copper (II): acetate decreases, which leads to unproductive consumption of acetate. Therefore, to obtain pure copper (II) acetate monohydrate in high yield, it is necessary to prepare a reaction solution containing copper (II) and acetate in a molar ratio of 1.0: (2.0-25.0).

The solubility of copper (II) acetate monohydrate increases with increasing solution temperature; a solution of copper (II) acetate is stable up to 66 ° С (Manual on preparative inorganic chemistry (under the editorship of Brauer G.) - M .: Izv. foreign literat., 1956, P.472), therefore, to increase the yield and obtain copper (II) acetate monohydrate without impurities of the basic salts of copper (II) crystallization is carried out at a temperature of preferably from -5 to 60 ° C.

Copper (II) acetate monohydrate crystallizes well from aqueous solutions, the precipitate easily settles without forming colloidal particles; therefore, many known methods can be used to separate it from the mother liquor (for example, filtration under ordinary or reduced pressure, centrifugation).

During filtration, the precipitate is easily separated from the mother liquor. If necessary, more complete removal of substances present in the mother liquor, the precipitate is washed on the filter with a suitable solvent, for example, chilled water, an aqueous solution of acetic acid, ethanol, acetone.

Copper (II) acetate monohydrate is not oxidized by oxygen and is stable in air up to 100 ° С. Drying of the product can be carried out at ordinary temperature, or to accelerate the drying process - in a stream of air at ordinary temperature or when heated to a temperature of 40-80 ° C.

Example 1

To 10.0 ml of spent etching solution for printed circuit boards with a copper (II) concentration of 1.5 mol / L, ammonia 3.3 mol / L, ammonium chloride 0.2 mol / L, ammonium carbonate 3.6 mol / L are added first 10 ml of water, then with stirring 20 ml of acetic acid, GOST 61-75 brand “h”. The solution is left to crystallize for 1 day at a temperature of 18 ° C. The precipitate is filtered off on a POR 100 glass filter, washed with acetone and dried in air at room temperature to constant weight. Yield 82%.

Found,%: C - 23.9; H - 4.0; Cu - 31.7.

Calculated for Сu (СН ₃ СОО) ₂ · Н ₂ O,%: С - 24.06; H - 4.04; Cu - 31.83.

Example 2

To 10.0 ml of the spent etching solution for printed circuit boards with a copper (II) concentration of 1.7 mol / l, ammonium chloride 1.5 mol / l, hydrogen chloride 0.4 mol / l, 2.9 ml of acetic acid are first added with stirring, GOST 61-75 brand “chda”, then in portions of 0.5 ml of a 30% sodium hydroxide solution until a pH of 3.0 is reached. The solution is left to crystallize for 1 day at a temperature of 22 ° C. The precipitate is filtered off on a POR 40 glass filter under reduced pressure, washed with a 70% aqueous solution of acetic acid, and dried in air at room temperature to constant weight. Yield 72%.

Found,%: C - 24.2; H - 3.8; Cu - 31.8.

Example 3

To 10.0 ml of spent etching solution for printed circuit boards with a copper (II) concentration of 0.96 mol / l, ammonia 7.3 mol / l, ammonium sulfate 0.45 mol / l, first 6.5 ml of water is added, then 17, 5 ml of an 80% solution of acetic acid, TU 6-09-07-1716-95. The solution was left to crystallize for 20 hours at a temperature of 20 ° C. The precipitate was filtered on a POR 16 glass filter under reduced pressure, washed with a 50% aqueous solution of acetic acid, and dried in air at room temperature to constant weight. Yield 72%.

Found,%: C - 24.1; H - 3.9; Cu - 32.2.

Example 4

A solution of 6.94 g of sodium acetate trihydrate is added to 10.0 ml of the spent etching solution for printed circuit boards with a copper (II) concentration of 1.7 mol / l, ammonium chloride 1.5 mol / l, and hydrogen chloride 0.4 mol / l. , GOST 199-78 brand “h” in 5.0 ml of water heated to 40 ° C. The solution was left to crystallize for 1.5 hours at a temperature of 20 ° C. The precipitate is filtered off on a POR 40 glass filter under reduced pressure, washed with chilled water and dried in air at room temperature to constant weight. Yield 88%.

Found,%: C - 23.8; H - 3.7; Cu - 31.8.

Example 5

To 10.0 ml of spent etching solution for printed circuit boards with a copper (II) concentration of 1.1 mol / l, ammonia 4.2 mol / l, ammonium chloride 0.4 mol / l, 10 ml of acetic acid are added with stirring, GOST 61- 75 brand “hch”. The solution is left to crystallize for 2 days at a temperature of 0 ° C. The precipitate is washed with a 70% aqueous solution of acetic acid, squeezed on a paper filter and dried in air at room temperature to constant weight. Yield 86%.

Found,%: C - 23.7; H - 3.9; Cu - 31.7.

The copper (II) acetate monohydrate obtained in Examples 1-5 is a dark green crystalline substance, soluble in water, glycerin, dimethylformamide, dimethyl sulfoxide, slightly soluble in ethanol, acetone, acetic acid, poorly soluble in carbon tetrachloride, benzene.

As can be seen from the above examples, the claimed method allows to obtain copper (II) acetate monohydrate with a high yield, exactly corresponding to the formula Сu (СН ₃ СОО) ₂ · Н ₂ O. The reduction of material costs for obtaining the product is achieved due to the fact that as one of the reagents, instead of copper (II) compounds, copper-containing spent etching solutions of printed circuit boards of various compositions are used. Simultaneously with obtaining a valuable product, it is possible to utilize the toxic waste of electronic production, to reduce environmental costs.

Claims (14)

1. A method of producing copper (II) acetate monohydrate, including preparing a reaction solution containing copper (II) and acetate, crystallizing the product, separating crystals from the solution and drying them, characterized in that the reaction solution is prepared by mixing the reagent that is the source of acetate, and the spent solution etching the printed circuit boards, moreover, in the reaction solution, a pH of from 0.5 to 7.0 and a molar ratio of copper (II): acetate equal to 1.0: (2.0-25.0) are set. 2. The method according to claim 1, characterized in that the solution containing copper (II), ammonia, ammonium chloride is used as the spent solution for etching the printed circuit boards. 3. The method according to claim 1, characterized in that the solution containing copper (II), ammonia, ammonium chloride, ammonium carbonate is used as the spent solution for etching the printed circuit boards. 4. The method according to claim 1, characterized in that as the spent solution for etching the printed circuit boards use a solution containing copper (II), ammonia, ammonium sulfate. 5. The method according to claim 1, characterized in that as the spent solution for etching the printed circuit boards use a solution containing copper (II), ammonia, ammonium sulfate, ammonium peroxodisulfate. 6. The method according to claims 1-5, characterized in that acetic acid is used as the reagent, which is the source of acetate. 7. The method according to claims 1-5, characterized in that as the reagent, which is the source of acetate, use acetic acid and hydrochloric acid. 8. The method according to claim 1, characterized in that as the spent solution for etching the printed circuit boards use a solution containing copper (II), hydrochloric acid. 9. The method according to claim 1, characterized in that the solution containing copper (II), hydrochloric acid, ammonium chloride is used as the spent solution for etching the printed circuit boards. 10. The method according to claim 1, characterized in that as the spent solution for etching the printed circuit boards use a solution containing copper (II), sulfuric acid, ammonium sulfate, ammonium peroxodisulfate. 11. The method according to PP.1,8-10, characterized in that as the reagent, which is the source of acetate, use acetic acid and sodium hydroxide, or acetic acid and potassium hydroxide, or acetic acid and ammonium hydroxide. 12. The method according to PP.1,8-10, characterized in that as the reagent, which is the source of acetate, use sodium acetate, or potassium acetate, or ammonium acetate. 13. The method according to claims 1-5, 8-10, characterized in that the production reagent containing acetic acid or sodium acetate or potassium acetate or ammonium acetate is used as a reagent that is a source of acetate. 14. The method according to claim 1, characterized in that the crystallization of the product is carried out at a temperature of from -5 to 60 ° C.