SU1518412A1 - Method of electrolytical or chemical coating - Google Patents

Abstract

The invention relates to electroplating, in particular, to electrochemical or chemical methods of applying coatings on complexly shaped parts, and can be used in engineering and other industries to create closed, waste-free coating technologies. The purpose of the invention is to increase the degree of washing of complexly shaped parts from the electrolyte, simplifying the method and reducing the consumption of surfactants. The electrolyte required for the application of metal, phosphate or chromate coatings is required to inject a surfactant or a mixture of surfactants in a concentration equal to the solubility limit of this surfactant or their mixture in this electrolyte at 18–20 ° C. . As a surfactant, unsaturated ethoxylated fatty acids (OFA) of the general formula R COO (C ₂ H ₄ O) _{N are used} , where RC ₁₆ -C _{25 is a} hydrocarbon radical of unsaturated fatty acids

N = 5-16

or their mixture. OFA is injected both into the electrolyte for coating and into the washing liquid (freon-113) at a concentration of 0.1-2.0 wt.%.

Description

The invention relates to electroplating, engineering, and in particular to electrochemical or chemical methods of applying coatings on complexly shaped parts, and can be used in engineering and other industries to create closed-waste coating technology.

The purpose of the invention is to increase the degree of removal of complexly shaped parts from the electrolyte, simplifying the method and reducing the consumption of surfactants.

The method is carried out as follows.

A surfactant or surfactant mixture in a concentration equal to the solubility limit of the surfactant or a mixture of these in the electrolyte at 12 is injected into the electrolyte required by the technological procedure intended for applying a metallic, phosphate or chromate coating. The surfactants in the electrolyte are dissolved with stirring, after which the electrolyte is filtered out of the insoluble excess of suspended particles.

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PiicTDOpeHi-ie and filtration is carried out on prm 12-18 C. Excess surfactant into electrolyte; or at any convenient temperature, the input to the electrolyte is the calculated amount of surfactant corresponding to the limit of their solubility at the required temperature. At the same time, prepare a wash based on freon-113 by introducing the same surfactant into it at a concentration of 0.1-2%. To do this, add the calculated amount of surfactant to the freon, mix the mixture until a homogeneous solution is formed and pour it into cover washing device

After preparing the electrolyte and washing liquid, the part to be treated with a clean, degreased surface is placed in an electrolyte bath saturated with a surfactant where the coating process is carried out under the parameters and conditions (temperature, current density, electrolysis time, etc.) which are provided by the technological regulations when using the Research Institute of electrolyte without surfactants,

After coating, the part is immediately placed in a washing device, in a cat-tor using a washing liquid (freon-13 and surfactant) by rinsing, dipping, or dosing (various types of vibrators, agitators, etc. can also be used to intensify the mixture). .) remove electrolyte from parts. The droplets of the washed electrolyte resurface onto the surface of the freon, since it has a large specific gravity, and form on it a continuous layer, which is allowed to stand and poured into a galvanic bath. Purified parts, not above the washing device, are lifted from the freon into the vapor phase and allow them to dry. The freon evaporating from the surface of the parts is condensed on the heat exchanger of the refrigerator located in the washing device, the condensate is drained into the washing liquid. After the drying process is completed, the washing device is opened, the part is removed and sent to the next electroplating company. operation or to the warehouse of finished products.

As a surfactant, unsaturated ethoxylated fatty acids (OFA) are used. Of the general formula RC00 (C2H, 0) H where R С -0 5 is a hydrocarbon radical of unsaturated fatty acids; or MX mix. In this case, the LLL is introduced as

-

Iq

20 25

Jq d

35

40

50

in freon-13 in a concentration of 0.1-2%, and in g alvanic electrolyte in a concentration equal to the limit of their solubility in the electrolyte at 12-18 C.

Oleox (;), naphthenox (R Cxfe-C s5 n 10-16) or other unsaturated coolant can be used as OFA.

In the case of using the invented method when carrying out a process involving hydrophobization of the surface of a part after chemical treatment (for example, during phosphating of ferrous metals), the operation of hydrophobization of parts in solutions of hydrophobicizing organosilicon liquid (GKZH-94) in gasoline (kerosene) is combined with removal of electrolyte, entering directly into the washing liquid on the basis of freon in a concentration of 10-20%.

When parts are removed from the electrolyte in a washing device equipped with a cooler for condensing freon vapors, the temperature of the liquid detergent composition and the washed electrolyte must be maintained within 12-18 s. Conducting electrolyte biting from the parts and saturating the original electrolyte electrolyte OHA at lower temperatures is impractical because of the possibility of salts from the washed out and source electrolyte, at high temperatures - due to a decrease in the complete washing of the electrolyte from the parts due to a decrease in surfactant concentration in the electrolyte the solubility of hydroxyethylated surfactants in aqueous media decreases). In addition, with increasing temperature, evaporation of freon-113 (tt (nrj.7 ° C)) significantly increases, which can lead to unnecessary energy costs for its return from the vapor phase.

Example 1 of a B electrolyte nickel plating (electrolyte 1) composition (g / l): 200; . 100; NaCl 10; thirty; RP 5 "4, at 15 ° C, oleox 5-.1 O (C, .H3, COO (C,) H5 gdn) is added in an amount of 3 g / l and dissolved with stirring, after which it is undissolved, excess oleox is filtered. A clean degreased complex-shaped part is immersed in the electrolyte ((M8 Id3 steel threaded bolt (pin 5.0 mm)) as the cathode, Nickel HI serves as the anode. The electrolysis is carried out in a 0.5 liter bath with stirring, at a cathode current density of 00 A / m, temperature, electrolysis time of 1 hour. The matte nickel precipitate obtained on the part meets all requirements in terms of adhesion quality, thickness and appearance and does not differ in these indicators from the sediment crawled under the same conditions. x deposition from electrolyte 1 without oleox.

Immediately after nickel plating, the wet part is placed in a washing device, which is a container sealed with a lid, about 3 cm in size, at the bottom of which is a drink of freon 113 containing 1% oleox 5-10 (0.4 l). Above the liquid fluid along the walls of the tank is a heat exchanger, executed in the form of a coil. The coil is connected by hoses to a refrigerator located outside the tank, which provides cooling and recirculation of the coolant (Tasol) through the heat exchanger. The surface temperature of the coil is maintained equal to -5 to. The nickel-plated wet part is suspended on the bar of the washing device, the cover is closed and the part is immersed in an organic liquid with the aid of a manipulator, intensively

Example 8: Electrolyte 1 for nickel plating;

kacha. After 1 min, cess is stopped, collected on the surface of the fre-, catfish-5 and filtered. Subsequent

operations and results as in example 1 ..

it is the layer of washed electrolyte is drained into the electroplating bath, and the part is lifted above the freon with the help of a rod and a manipulator without withdrawing it from the washing device. In such a state, the research institute keeps the part for 10 minutes, allowing the freon to evaporate from the part, condense on the heat exchanger and drain.

, at the bottom of the tank. The cover of the washing device is lifted, the washed dry dedd

t-hoist taken out.

PRI me R 9. Electrolyte 1 for nickelization at 12 s is saturated with fenoxom (CmH2k-4COO () H, where 25;) and filtered. In freon-113, the same surfactant is introduced at a concentration of 1%. All subsequent operations are carried out as in Example 1. The results are identical to those obtained in Example 1,

I'll try it on. Electrolyte 1 for nickel plating with oleoxom 5-10 and filtered. All the details, when examining its dod microscope at a 20-fold magnification of the traces of electroplating electro-CQ, the following operations are carried out in the same way, lit (droplets, spots, dots) half as in example 1. After washing the details

PRI mme R 2. All operations provoto ;. d t, as in example 1, except that oleox 5-10 is introduced into freon in an amount of 0,%. The results are obtained as in example 1.

PRI me R 3. All operations are carried out as in Example 1, except

the fact that oleox 5- -10 was introduced into freon in an amount of 2%. Results like

in example 1.

EXAMPLE 4. All operations were carried out as in Example 1, except that no oleoxide was introduced in the freon 13. After washing the parts, isolated electrolyte droplets are visible on the surface of the grooves.

EXAMPLE 5 All operations are carried out as in the example.

with the exception of

the fact that oleox is not introduced into the electroplating electrolyte. The result, in example 4.

Example 6. The operations are carried out as in 1, except that the galvanic electrolyte and Freon-113 do not contain oleox additives. The result is as in Example 4 ..

Example. All operations are carried out as in Example 1, except that oleox 5- -10 is introduced into freon in an amount of 0.08%. The results, as in example 4,

EXAMPLE 8 Electrolyte 1 for nickel plating with oleox-5 is pressed and filtered. Subsequent

PRI me R 9. Electrolyte 1 for nickel plating at 12 s is saturated with fenoxom (CmH2k-4COO () H, where 25;) and filtered. In Freon-113, the same surfactant is introduced at a concentration of 1%. All subsequent operations are carried out as in Example 1. The results are identical to those obtained in Example 1,

I'll try it on. Electrolyte 1 for nickel plating with oleoxom 5-10 and filtered. All subsequent operations are carried out as in Example 1. After washing the parts

no. Repeating the coating operation — washing the part — returning the washed electrolyte to the electroplating bath (up to 40 times) does not lead to a change in the quality of the coatings, nor to a decrease in detergency and full washing with the Freon-OHA composition.

55

residues of an unwashed electrolyte are detected in their threads (1-2 drops per part).

Example P The electrolyte 1 for nickel plating at 20 ° C is saturated with oleoxide. All subsequent operations are performed in the same manner as in Example 1. While defending the washed

electrolyte

electrolyte, irakyl; e razdhga electrolyte-freon precipitates oleox G1rep tc7 zuyu1; -}. And a complete separation to: the hell of each other. When you reuse the rinsed electrolyte on the usability of the nickel coating on the backing, point defects are removed after additional filtering of the electrolyte,

PRI me R 12, In galvanic. (2) for cadmium plating 5 co / l: 2H, 20 60 | (mi4) .SO 150-H.jBOj 30; additives DHTI Z03A and 203B by 30; lzodkt 3 g / l ole--. OKca - 5 10s is dissolved and from filthy-feaioT excess. Dissolution and F1-Shtra-1ZI10 are carried out at 18 ° C, cadmium | complex-shaped parts (steel-bolt 50 mm long with MB thread) IB prng electrified lead 1 at a cathode current density of 200 A / m and temperature of 20 ° C. for 30 minutes All subsequent operatives are provo /. t so} ke.5 as in example 1 "The resupply results are obtained in example 1 ,.

Example 13, Copper electroplating electrolyte (3) containing | g / l; Si50d 5H 35; t 130; 12Lor 90 (pH S) 9 are treated with oleox 5 0 at, a solution from Ailtrovyvag Copper deposition, polish. and lead to the part of the steel STS. 3; having a threaded hole M iO 40 mm depth with cathodic density of current 40 temperature; electrolysis time 20 min. All carrying out operations are carried out as in 1, the results are obtained in example 1

Example 14, B electroplating phosphate (4) containing; g / ll salt Mazhef 30; Zn (ms) o 60j NaF 3, enter 3 g / l oleo 5-105 dissolved with an excess of acid and heat. The electrolyte obtained is heated to 95 ° C and bathed in 30 min steel complex , - Threaded threaded through otnosti MB 30 mm deep and n-through diameter 2 mm in diameter and 0 mm deep. The resulting phosphate coating on the part is fine crystalline homogeneous, dense honey does not differ in appearance and weight (752 g / m) from the coating obtained in electrolyte 4 without oleox at the same gemps and treatment time.

0

0

five

0

0

five

After phosphating, the wet part is placed in a washing device described in example 1j in which freon-PZ containing 10% NGL-94 and% oleox 5- Oj is contained. Washing the part, drying it and returning the electrolyte to the phosphatizing bath are carried out as well 5 in Example 3, Traces of electrolyte to the washed part are missing. Repeated - repetition of the operative phosphatizing - washing - returning the electrolyte to the galvanic bath (up to 30 times) does not lead to any changes in the quality of the coatings; nor to a decrease in the detergency of comosidy freon-GKZh-oleox,

After removing the freon from the part, it is placed in a drying cabinet heated to where it is removed for 1 hour.

Accelerated corrosion tests of phosphorus-coated phosphate parts are carried out by keeping them in an aqueous solution of sodium chloride, salt for 3 days with a single corrosion resistance to change the appearance of the parts and weight gain, Comparison of phosphatized parts; hydrophobized (after washing with water and drying) by treating in a solution of 10% HA) K-94 in gasoline for 5 minutes followed by heat treatment at 130 ° C for 1 h. The corrosion resistance of the parts being compared is identical.

Example 15 (prototype). A freshly-grained, wet, complexly shaped part (Sbolt steel with MSxl thread 50 mm in length), covered with nigkel in electrolyte 1, is placed in a washing device. 20% 7nol oxanol so Freon-PZ is used as a detergent composition. - from freon, separation of electrolyte from freon is carried out in the same way as in example 1. On the surface of the washed part in the grooves of the thread there are separate (1-3 per part) droplets of the remaining eactrolite. When a direct return of the electrolyte from freon to the electroplating bath, the quality of the coatings deteriorates (spots, stripes). After repeated repetitions (.0 times) of the operations, the application of the coating — the washing capacity of the composition of freon-oxanol is reduced (and the washed parts have numerous components left in the electrolyte thread).

PRI me R 16 (prototype). 10% ethylene glycol distearate in freon-113 is used as a detergent composition. The rest, as in the example, is 15. The results are identical to those obtained in example 15.

Example 17 (prototype). As a detergent composition using 3% OP-7 in freon. The rest, as in example 15. When removing the parts, the formation of a concentrated, hard-to-separate emulsion is observed, which makes the separation of the washing liquid from the electrolyte almost impossible.

The advantages of the proposed method are to provide complete electrolyte discharge from complex shaped parts | eliminating the need for purification of surfactants and adjusting the washed electrolyte for organic additives when it is reused, eliminating the need for frequent adjustments of freon for surfactants to maintain its detergency and reducing surfactant consumption for the washing operation, eliminating the need for all major and related operations with the sorption purification of electrolyte from surfactants (preparation of the sorbent, its periodic regeneration, utilization of eluates, etc.), simplification of the processes involving g drofo- Byzacena parts after treatment for

Combining operations hydrophobic 0

five

p 5 about

five

tion and otmyuki detailed from electrolyte - and the exclusion of fire hazard.

Claims (1)

Invention Formula The method of electrolytic or chemical coating, including electrolytic or chemical treatment of the surface of complexly shaped parts, removing them from electrolyte residues with a washing liquid containing freon-113 and surfactants, and returning the freon-PZ from the surface of the washed parts to the washing liquid by recondensing it on the refrigerator, characterized in that, in order to increase the degree of removal of complexly shaped parts from the electrolyte, simplify the method and reduce the consumption of surface-active substances, active substances are introduced into the washing liquid in an amount of 0.1-2.0 wt.%, and into the electrolyte for electrolytic or chemical treatment - at a concentration equal to the limit of their solubility in the electrolyte at 18–20 ° C, unsaturated oxyethylated fatty acids of general formula are used as surfactants. RCOO () nH, where R - C; (bc 25 hydrocarbon radical of unsaturated fatty acids; p 5-16, or their mixture.