RU2629023C1 - Detergent composition for purifying metal surfaces - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: detergent composition is described containing trisodium phosphate, disodium ethylenediaminetetraacetate, monoalkyl- or dialkyl polyglycol ether, trilon B-dilylthiopentaborate complex, and water.

EFFECT: increasing the detergent and passivating properties of the detergent composition.

3 tbl

Description

The invention relates to detergent compositions for cleaning metal surfaces from industrial pollution.

Known detergent composition for cleaning metal surfaces, including polyglycol ether of synthetic fatty alcohols (syntanol); soda ash; sodium tetraborate, sodium phosphate disubstituted (phosphoric acid salt), sodium pyrophosphate; aqueous 3.5-5.0% solution of salts of alkylphosphoric acids (syntaph) (RU 2054034, IPC C11D 1/72, publ. 02/10/1996).

The disadvantages of the known compositions are low detergent and anticorrosive properties when cleaning the surface of the metal.

Closest to the claimed technical solution is a detergent for cleaning a metal surface, including ammonium pentaborate dimonoethanolamine, disodium ethylene diamine tetraacetate, trisodium phosphate, monoalkyl or dialkyl polyglycol ether. SU 1004463, IPC 5 C11D 3/06, publ. 03/15/83.

The disadvantages of the known washing composition are its insufficient washing ability and anticorrosion properties when cleaning the surface of the metal, because ammonium pentaboratedimonoethanolamine complex salts out on the surface of the purified metal and is poorly removed by washing, which leads to secondary corrosion of the metal.

The objective of the invention is to provide a detergent composition for cleaning metal surfaces with improved detergent and anticorrosion properties (passivation).

Effect: increase the washing and anticorrosive properties of the composition.

The technical result is achieved in that the detergent composition for cleaning a metal surface containing trisodium phosphate, disodium ethylene diamine tetraacetate, monoalkyl or dialkyl polyglycol ether, according to the invention additionally contains a dilithium pentaborate complex of trilon B, in the following ratio of components, wt. %:

Trisodium phosphate 1.5-2.5 Disodium ethylene diamine tetraacetate 1.0-1.5 Monoalkyl or Dialkyl Polyglycol Ether 0.2-0.4 Dilithium pentaborate complex trilon B 0.5-1.0 Water rest

The difference between the proposed solution and the known one consists in the use of a new compound, the dilithium pentaborate complex of trilon B, of the general formula 2LiB ₅ O ₈ ⋅C ₁₀ H ₁₄ O ₈ N ₂ Na ₂ ⋅ 2H ₂ O, which increases the washing and anticorrosive properties of the solution .

The trilon B dilithium pentaborate complex was prepared as follows: 1 liter of distilled water was placed in a reaction vessel and 378.0 g (2 mol) of lithium pentaborate and 336.0 g (1 mol) of trilon B were dissolved in it. The mixture was continuously stirred for 3-4 hours at room temperature. Then the solution was transferred to a crystallization crystallizer. The product yield was 686.9 g (or 96.2%) based on the anhydrous salt. Chemical analysis found, mass. %: 50.32 - lithium pentaborate, and 44.86 - trilon B. The refractive index of the obtained compound, measured by the immersion method, is 1.372, and its density found in benzene and toluene is 1.482 g / cm ³ .

A detergent composition was prepared by sequentially dissolving trisodium phosphate, disodium ethylene diamine tetraacetate, monoalkyl or dialkyl polyglycol ether, and trilon B dilithium pentaborate complex in water with stirring.

The compositions are given in table. one

The washing ability of the claimed composition was determined by a known method by the gravimetric method, which is based on determining the percentage of washability of contaminants from the surface of the part (Fadeev IV, Sadetdinov Sh.V. “Synergistic effect of pentoborates of lithium, sodium and potassium in the presence of amino alcohols in synthetic detergents” Bulletin of the Moscow Automobile and Highway State Technical University (MADI) ”⎪ Issue 3 (46), September 2016).

For testing, parts with a surface roughness of 0.32-0.61 with a size of 100 × 50 × 1.5 mm were used. They were degreased with ether and held for 5-10 minutes until the ether was completely evaporated and they assumed a constant temperature. Details were weighed on an analytical balance to the nearest 0.0001 g. Then, a uniform layer of contamination was applied with a glass rod. The amount of contamination applied should be approximately the same on all parts and be 0.08-0.085 g. Then, the contaminated parts were placed in a laboratory washer and washed for 2 minutes.

After washing, the parts were washed with distilled water and dried by blowing air from a fan at room temperature. After drying, they were weighed. The percentage of removed contamination from the surface was determined by the formula:

,

,

where P ₀ is the initial weight of the sample (pure), g;

P ₁ is the weight of the contaminated sample, g;

P ₂ - weight of sample after washing, g

When determining the wetting ability, samples (metal plates measuring 150 × 70 mm) were first immersed in the prepared detergent solution, and then in demineralized water for 10 seconds. Next, the samples were removed from the water and a violation of the continuity of the water film was recorded visually. In this case, the surface removed from the edges and sharp edges by less than 10 mm was not taken into account. Wetting ability is characterized by the time, in seconds, from the start of testing to rupture of the water film. The data obtained are presented in table. 2.

From table 2 it follows that when the content of the number of components in the washing composition is lower than the declared boundary values (composition No. 1), the degree of purification and wettability are low and contaminants are not removed from the metal surface.

According to the washing action and wettability, the compositions No. 2, No. 3, No. 4, No. 5 are approximately the same. They allow you to almost completely clean the surface of the samples from contamination. The known composition (prototype) cleans the surface by only 82.7%. However, composition No. 5 has a rather high quantitative content of components, which is associated with a large consumption of material, without a significant improvement in the washing properties of the composition.

Thus, in comparison with the known detergent composition (prototype), the proposed composition improves the quality of the surface being cleaned due to improved detergent properties.

The anticorrosive properties of the detergent composition were determined by potentiodynamic measurement of the density of the anode current at several potential values. Potentiodynamic polarization (sweep speed 1 mV / s) was carried out using a P-5848 potentiostat. The reference electrode is silver chloride (h.s.e.). GOST 17792-72

The research results are given in table. 3.

Electrochemical measurements indicate that with anodic polarization steel Art. 10 in the studied solutions immediately goes into a passive state. The dissolution rate of steel in the proposed detergent composition (compositions No. 2, No. 3, No. 4) is 0.9-1.3 μA / cm ² lower than in the prototype. Without polarization, the potential of the steel is shifted in the positive direction and causes the passivation of the metal.

Electrochemical studies show that the inventive detergent composition exhibits higher anticorrosive properties than the prototype.

The test results of various compositions of detergent compositions for cleaning a metal surface confirmed that the detergent composition prepared according to compositions 2-4 has optimal properties (high purity of 99% and good passivation quality) compared to the prototype.

The proposed washing solution is industrially applicable for cleaning the metal surfaces of parts that are restored during the repair of cars and assemblies from pollution and can be used in preparing the metal surface before applying paint or varnish or metal coatings in mechanical engineering and other industries.

Claims (2)

Detergent composition for cleaning metal surfaces containing trisodium phosphate, disodium ethylene diamine tetraacetate, monoalkyl or dialkyl polyglycol ether and water, characterized in that the solution additionally contains a dilithium pentaborate complex of trilon B of the general formula 2LiB ₅ O ₈ ⋅C ₁₀ H ₁₄ O ₈ N ₂ Na ₂ ⋅ 2Н ₂ Oh, in the following ratio of components, wt. %:  Trisodium phosphate 1.5-2.5  Disodium ethylene diamine tetraacetate 1.0-1.5  Monoalkyl or Dialkyl Polyglycol Ether 0.2-04  Dilithium pentaborate complex trilon B 0.5-1.0  Water rest