RU2304157C1 - Lacquered composition and method for preparing protective lacquered cover on aluminum alloy-base devices - Google Patents

Abstract

FIELD: protective compositions.

SUBSTANCE: invention relates to a lacquered protective composition and a method for preparing the lacquered cover on devices made of aluminum alloys. Lacquered composition comprises lacquer KCH-0125 (STP6-1-48-95) representing 68 ± 2% maleinized polybutadiene in diacetone and isopropyl alcohol wherein this polybutadiene is modified with phenolic resin with addition of 25% aqueous ammonia solution and mixture of isopropyl alcohol and water taken in the ratio = 1:1 and wherein these components are taken in the following ratio: lacquer KCH-0125, 120-150 g/l; 25% aqueous ammonia solution, 4-7 ml/l; mixture of isopropyl alcohol and water in the ratio 1:1, the balance, up to 1, pH of the composition is 6.5-7.5. Method for preparing is based on etching, washing out in hot running water, washing out in cold running water, clearing, washing in cold running water, chemical oxidizing, washing out in cold running water, removing drop moisture, chemical defatting, washing out in cold running water, applying indicated lacquered composition by simple immersion for 2-4 min at temperature 15-35°C, washing out in cold running water, fixation of lacquered cover in solution of the following composition: linoleic acid, 3 ml/l; oxalic acid, 3 g/l; mixture of isopropyl alcohol and water in the ratio 1:1, the balance, up to 1 l, washing out in cold running water, removing moisture and thermal hardening at temperature 120-130°C for 30 min, not less. Invention provides creature of lacquered protective composition able to form the corrosion-resistant lacquered protective cover on surface of devices made of aluminum alloys in prolonged temporary intervals between procedures for oxidizing and applying the lacquered composition. Invention can be used in radio engineering, aircraft industry, instrument making and other fields for articles exploited under different climatic conditions.

EFFECT: improved preparing method, valuable technical properties of composition.

3 cl, 3 ex

Description

The invention relates to a lacquer protective composition and a method for producing a protective lacquer coating on devices made of aluminum alloys and can be used in the radio engineering industry, instrumentation, aircraft industry and in other areas of the national economy for products operated in various climatic conditions.

A protective lacquer composition for aluminum alloy products is known in modern technology [RF Patent No. 2196156, published January 10, 2003], based on KCH-0125, which is a 68 ± 2% solution of maleated polybutadiene modified with isopropyl and diacetone alcohol phenolic resin with the addition of aqueous ammonia 25%, and a mixture of isopropyl alcohol and water in a ratio of 1: 1 and fatty acid desiccant ZhK-10 in the following ratio of components, g / l:

Varnish KCh-0125 270-300 Ammonia water 25%, ml / l 14-16 Fatty acid drier LCD-10 12-18 A mixture of isopropyl alcohol and water (1: 1) up to 1 l pH of the composition 6.5-7.0

Obtaining a protective lacquer coating on complex waveguides made of aluminum alloys includes etching, washing in hot running water, washing in cold running water, clarification, washing in cold running water, chemical oxidation of conductive, washing in cold running water, applying the varnish composition is carried out at a temperature 15-35 ° C by simple immersion for 4-6 minutes, washing in cold running water, removing droplet moisture, drying at a temperature of 125-180 ° C for at least 1 hour.

The disadvantage of such a protective lacquer composition and a method for producing a protective lacquer coating is the inability to obtain it with a long time interval between the operations of chemical oxidation and applying the varnish composition.

The closest in technical essence to the proposed protective lacquer composition is the composition [Patent No. 2230762, published June 20, 2004] based on KCH-0125 varnish, which is a 68 ± 2% solution of maleated polybutadiene modified with phenol in isopropyl and diacetone alcohol resin with the addition of aqueous ammonia 25%, and a mixture of isopropyl alcohol and water in a ratio of 1: 1 in the following ratio of components:

Varnish KCh-0125 50-100 g / l Ammonia water 25% solution 3-6 ml / l A mixture of isopropyl alcohol and water (1: 1) up to 1 l pH of the composition 6.5-7.2

and a method of obtaining a varnish coating on complex waveguide devices made of aluminum alloys, comprising the following operations: etching, washing in hot running water, washing in cold running water, clarification, washing in cold running water, chemical oxidation, washing in cold running water, removing droplet moisture, chemical degreasing, washing in cold running water, applying the varnish composition by simple immersion for 2-4 minutes, removing from the composition, immersion in a solution of activators Composition:

phosphoric acid, ml / l one auxiliary substance OP-7 or OP-10, g / l 0.1

for 1-3 minutes at a temperature of 15-35 ° C, removing from the composition, washing in cold running water, removing moisture and curing at a temperature of 125-180 ° C for at least 1 hour.

However, the varnish composition and the method of obtaining a protective varnish coating with a long time interval between the operations of chemical oxidation and applying the varnish composition does not allow to obtain a corrosion-resistant coating due to the small thickness of the protective film formed.

An object of the invention is to provide a protective lacquer composition capable of forming a corrosion-resistant protective lacquer coating on the surface of devices made of aluminum alloys with a long time interval between the operations of oxidation and applying the lacquer composition.

The solution to the problem is achieved by the proposed lacquer composition for devices made of aluminum alloys based on lacquer KCH-0125 (STP6-1-48-95), which is a 68 ± 2% solution of maleated polybutadiene in diacetone and isopropyl alcohol modified with phenolic resin with the addition of aqueous ammonia 25 % and a mixture of isopropyl alcohol and water in a ratio of 1: 1, and the ratio of components is, g / l:

Varnish KCh-0125 120-150 Ammonia water 25%, ml / l 4-7 A mixture of isopropyl alcohol and water 1: 1 up to 1 l pH of the composition 6.5-7.5

A method of obtaining a protective varnish coating on devices made of aluminum alloys based on etching, washing in hot running water, washing in cold running water, clarification, washing in cold running water, chemical oxidation, washing in cold running water, removing droplet moisture, chemical degreasing washing in cold running water, applying a lacquer composition, g / l:

Varnish KCh-0125 120-150 Ammonia water 25%, ml / l 4-7 A mixture of isopropyl alcohol and water 1: 1 up to 1 l pH of the composition 6.5-7.5

by simple immersion for 2-4 minutes at a temperature of 15 ÷ 35 ° C, washing in cold running water and thermosetting. New in the proposed method is that after applying the varnish composition fix the varnish in a solution of the composition:

Linoleic acid (GOST 6552-80) - 3 ml / l Oxalic acid (GOST 8433-81) - 3 g / l A mixture of isopropyl alcohol and water in a ratio of 1: 1 up to 1 l

and thermosetting is carried out at a temperature of 120-130 ° C for at least 30 minutes.

Example 1

Corrosion protection of devices made of aluminum alloys was carried out, with a gap between the operation of oxidation and applying the varnish composition for 30 days, with the following method of obtaining a protective varnish coating:

- etching, for example, in a NaOH solution of 50 g per 1 liter at a temperature of 60 ° C for 30 seconds,

- flushing in hot running water,

- flushing in cold running water,

- clarification in a solution of HNO ₃ and water in a ratio of 1: 1 at a temperature of 20 ° C for 15 seconds;

- flushing in cold running water,

- chemical oxidation in a solution of the composition, g / l:

Phosphoric acid 40 Chromic anhydride 5 Sodium Fluoride 3

at a temperature of 20 ° C for 8 minutes;

- flushing in cold running water,

- removal of drip moisture,

- chemical degreasing, for example, in a solution of composition OP-10 at a temperature of 30 ° C for 20 minutes;

- flushing in cold running water,

- applying a varnish composition composition:

Varnish KCh-0125 120 g / l Ammonia water 25% 4 ml / l Isopropyl alcohol mixture and water in a ratio of 1: 1 up to 1 liter pH of the composition 6.5-7.5

simple immersion for 3 minutes at a temperature of 15 ° C;

- flushing in cold running water,

- fixing the varnish coating in a solution of the composition:

linoleic acid 3 ml / l oxalic acid 3 ml / l Isopropyl alcohol mixture and water in a ratio of 1: 1 up to 1 liter

for 2 minutes at a temperature of 20 ° C;

- flushing in cold running water,

- removal of moisture by blowing,

- thermosetting at a temperature of 120 ° C for 1 hour.

These parts were tested for cyclic exposure to temperatures from -60 to 85 ° C (3 cycles), exposure to tropical humidity for 12 days (relative humidity 98 ± 2% at 40 ° C) and sea fog for 7 days.

After testing, the appearance of the varnish film remained unchanged, no corrosion was found on aluminum alloy parts.

Example 2

Corrosion protection was carried out by the proposed protective varnish composition of waveguide structures made of aluminum alloys with a channel cross section of 13 × 3 with a length of 500 mm with a gap between the operation of oxidation and applying the varnish composition for 28 days, according to the following method of obtaining a protective varnish coating:

- etching, for example, in a NaOH solution of 50 g per 1 liter at a temperature of 60 ° C for 30 seconds,

- flushing in hot running water,

- flushing in cold running water,

- clarification in a solution of HNO ₃ and water in a ratio of 1: 1 at a temperature of 20 ° C for 15 seconds;

- flushing in cold running water,

- chemical oxidation, as in example 1,

- flushing in cold running water,

- removal of drip moisture,

- chemical degreasing, for example, in a solution of composition OP-10 at a temperature of 30 ° C for 20 minutes,

- flushing in cold running water,

- applying a varnish film by immersion in a varnish composition of the following composition:

Varnish KCh-0125 130 g / l Ammonia water 25% 6 ml / l A mixture of isopropyl alcohol and water 1: 1 up to 1 l pH of the composition 7.0

for 3 minutes at a temperature of 20 ° C;

- flushing in cold running water,

- fixing the varnish coating in a solution of the composition:

Linoleic acid 3 ml / l Oxalic acid 3 g / l A mixture of isopropyl alcohol and water in the ratio 1: 1 up to 1 l

within 2 minutes at a temperature of 25 ° C;

- flushing in cold running water,

- removal of moisture by blowing,

- curing at a temperature of 125 ° C for 1.0 hour.

Received benign in appearance coatings, firmly adhered to the aluminum base. After testing for exposure to high humidity and sea fog (example 1), the appearance of the varnish film remained unchanged. Corrosion on parts made of aluminum alloys was not observed.

Example 3

The corrosion protection of the device made of aluminum alloys was carried out with a gap between the operation of oxidation and applying the varnish composition of 25 days, as follows:

- etching, for example, in a NaOH solution of 50 g per 1 liter at a temperature of 60 ° C for 30 seconds,

- flushing in hot running water,

- flushing in cold running water,

- clarification in a solution of HNO ₃ and water in a ratio of 1: 1 at a temperature of 20 ° C for 15 seconds;

- flushing in cold running water,

- chemical oxidation, as in example 1,

- flushing in cold running water,

- removal of drip moisture,

- chemical degreasing, for example, in a solution of composition OP-10 at a temperature of 30 ° C for 20 minutes,

- flushing in cold running water,

- applying a varnish film by immersion in a varnish composition composition:

Varnish KCh-0125 150 g / l Ammonia water 25% 7.0 ml / l A mixture of isopropyl alcohol and water 1: 1 up to 1 l pH of the composition 6.5

for 3 minutes at a temperature of 20 ° C;

- flushing in cold running water,

- fixing the varnish coating in a solution of the composition:

Linoleic acid 3 ml / l Oxalic acid 3 g / l A mixture of isopropyl alcohol and water in the ratio 1: 1 up to 1 l

within 2 minutes at a temperature of 25 ° C;

- flushing in cold running water;

- removal of moisture by blowing,

- curing at a temperature of 125 ° C for 1.0 hour.

After testing for exposure to high humidity and sea fog (example 1), the appearance of the varnish film remained unchanged. Corrosion on parts made of aluminum alloys was not observed.

Claims (2)

1. The lacquer composition for devices made of aluminum alloys based on varnish KCH-0125, which is a 68 ± 2% solution of maleated polybutadiene modified with phenolic resin in diacetone and isopropyl alcohol, with 25% aqueous ammonia and a mixture of isopropyl alcohol and water in 1: 1 ratio, characterized in that the ratio of components is, g / l: Varnish KCh-0125 120-150 Ammonia water 25%, ml / l 4-7 A mixture of isopropyl alcohol and water 1: 1 up to 1 l pH of the composition 6.5-7.5 2. A method of obtaining a protective varnish coating on devices made of aluminum alloys, based on etching, washing in hot running water, washing in cold running water, clarification, washing in cold running water, chemical oxidation, washing in cold running water, removing droplet moisture, chemical degreasing, washing in cold running water, applying the varnish composition according to claim 1 by simple immersion for 2-4 minutes at a temperature of 15-35 ° C, washing in cold running water, fixing the varnish in solution re composition: Linoleic acid 3 ml / l Oxalic acid 3 g / l Isopropyl alcohol mixture and water in a ratio of 1: 1 up to 1 l washing in cold running water, removing moisture and curing at a temperature of 120-130 ° C for at least 30 minutes