RU2444580C1 - Copper etching composition - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: copper etching composition includes complexons of 3,5-di-tert-butylbenzoquinone-1,2 and acetylacetone in molar ratio of 1:2 in solution of tetrahydrofuran.

EFFECT: composition improves copper etching in organic media and allows obtaining maximum output of commercial product without formation of by-products.

Description

The invention relates to a composition for pickling metals and can be used in the engineering and electronic industries for pickling copper surfaces and printed circuit boards.

Copper etching uses compositions containing complexones of various structures, such as acetophenoxy, tetrachlorobenzoquinone-1,2,3,5-di-tert-butylbenzoquinone-1,2 [1, 2].

Of the known compositions for copper etching in an organic solvent, the composition containing acetophenoxy and acetylacetone is closest to the proposed composition, where copper etching proceeds with the formation of products in the form of copper (II) acetylacetonate, benzonitrile and benzoic acid [1].

The disadvantage of the prototype is the complex occurrence of processes during etching of copper and, as a consequence, the formation of a mixture of by-products and a low yield (3-28%) of the main commercial product - copper (II) acetylacetonate.

The difference between the present invention and the prototype is that acetophenoxy is replaced by the complexone 3,5-di-tert-butylbenzoquinone-1,2, which with acetylacetone in a molar ratio of 1: 2 in a solution of tetrahydrofuran gives a composition for etching copper.

EFFECT: proposed composition improves copper etching in organic media that proceeds without formation of by-products and with a maximum yield (up to 96%) of a commercial product — copper (II) acetylacetonate.

The composition for copper etching, containing complex acetylacetone in an organic solvent, additionally contains complex 3,5-di-tert-butylbenzoquinone-1,2 in a molar ratio of 1: 2 with respect to acetylacetone, while the composition contains tetrahydrofuran as an organic solvent.

The specified technical result is achieved by the fact that the copper surface is treated with a composition containing 3,5-di-tert-butylbenzoquinone-1,2 complexones and acetylacetone in a 1: 2 molar ratio in tetrahydrofuran solution.

The essence of the invention lies in the fact that the composition for etching copper, which contains complexones - 3,5-di-tert-butylbenzoquinone-1,2 and acetylacetone in a molar ratio of 1: 2 in a solution of tetrahydrofuran, treats the surface of metallic copper. Copper etching proceeds without the formation of by-products, with a high yield (96%) of a commercial product — copper (II) acetylacetonate.

For this, a defatted copper plate (2.0 g) is placed in a solution of 3,5-di-tert-butylbenzoquinone-1,2 (5.5 g) and acetylacetone (5.2 g) in 50 ml of tetrahydrofuran. The reaction mixture was refluxed for 7 hours. The precipitated blue crystals of copper (II) acetylacetonate are filtered off, washed with tetrahydrofuran, and dried. The resulting product 3,5-di-tert-butylpyrocatechol remains in solution. The amount of dissolved copper 1.5 g.

The output of the complex of copper (II) acetylacetonate is 6.3 g (96%). The resulting product corresponds to CAS-Nr. 13395-16-91, T _pl = 245 ° C.

The proposed component composition for etching copper can be characterized as follows. Tetrahydrofuran is a solvent (CAS-Nr. 109-99-9). Acetylacetone is a complexone manufactured by the industry (ChDA, GOST 10259-78). 3,5-di-tert-butylbenzoquinone-1,2 is a chelate complexone and is synthesized as follows.

1. To a solution of 22 g (0.2 mol) of catechol suspended in 44 g (7 mol) of tert-butyl alcohol, 30 ml of concentrated sulfuric acid was added dropwise with stirring. The temperature of the reaction mixture should not exceed 25 ° C. Upon completion of the addition of sulfuric acid (4 hours), the reaction mixture was washed with water until neutral; 3,5-di-tert-butylpyrocatechol was dissolved in hexane. The solution was dried from water with anhydrous sodium sulfate, the solvent was removed. The resulting 3,5-di-tert-butylpyrocatechol was recrystallized from hexane. The yield of 3,5-di-tert-butylpyrocatechol was 80% (35 g); colorless needles; _Mp = 109-110 ° C.

2. 22.2 g (0.1 mol) of 3,5-di-tert-butylpyrocatechol was dissolved in 40 ml of sulfuric ether. The ether solution was added to the oxidation mixture with stirring (an aqueous solution of 150 g of red blood salt and 15 g of sodium hydroxide). After 2 hours, ether was removed from the reaction mixture by bubbling air. The secreted o-quinone was filtered; washed with water until neutral; dissolved in hexane; hexane was removed. The obtained crystals of o-quinone were recrystallized from hexane. The yield of 3,5-di-tert-butylbenzoquinone-1,2 was 70% (15 g); _Mp = 113 ° C.

Literature

[1] Kalambetova L.S., Starkova N.N. // Bulletin of the Astrakhan Technical University. 2007. No. 6. S.28-30.

[2] Abakumov G.A., Cherkasov V.K., Lobanov A.V., Razuvaev G.A. // Izv. USSR Academy of Sciences. Ser. Chem. 1984. No. 7. S.1610-1618.

Claims (1)

Composition for copper etching containing complexone acetylacetone in an organic solvent, characterized in that it further comprises complexon 3,5-di-tert-butylbenzoquinone-1,2 in a molar ratio of 1: 2 with respect to acetylacetone, while as an organic solvent the composition contains tetrahydrofuran.