RU2303081C1 - Metal corrosion inhibitor and slushing oil containing this inhibitor - Google Patents

Abstract

FIELD: protection of metals against atmospheric corrosion by means of inhibitors; protracted preservation of the metalwork and ferrous and non-ferrous items.

SUBSTANCE: proposed inhibitor contains the following components, mass-%: product of condensation of boric acid with diethanol amine and vegetable oil at mole ratio of 1:3: (0.-0.7), respectively, 85-95 and benzotriazole, 5-15. Slushing oil on base of mineral oil contains 17-25 mass-% of inhibitor.

EFFECT: extended field of application; enhanced protective and water-repellent properties.

3 cl, 3 tbl

Description

The invention relates to the field of protection of metals from atmospheric corrosion with the help of inhibitors and can be used for long-term preservation of metal structures and products from ferrous and non-ferrous metals.

Known metal corrosion inhibitor, which is a condensation product of boric acid with diethanolamine and vegetable oil with a molar ratio of reactants 1: 3: (1-2), respectively. Use an inhibitor in an amount of 20-40 wt.% In nephras, arctic diesel fuel, aviation kerosene (RU 2207402 C1, cl C23F 11/14, 06/27/2003).

The inhibitor working solution protects metals from corrosion in water-oil hydrogen sulfide-containing media, but its active base is insoluble in mineral oils, therefore it is not effective in protecting metals from atmospheric corrosion.

The closest analogue of the proposed technical solution is a metal corrosion inhibitor, which is a condensation product of boric acid with diethanolamine and vegetable oil with a molar ratio of reactants 1: 3: (0.5-0.7), respectively. This inhibitor is used in an amount of 10-16 wt.% In mineral oil for the conservation of metal products (RU 2263160 C1, CL C23F 11/14, 10.27.2005).

The disadvantage of preservation oil containing the specified inhibitor is that it does not protect metal products from alloy steel, magnesium, aluminum and their alloys from atmospheric corrosion.

The objective of the invention is to develop a universal inhibitor of atmospheric corrosion, as well as preservation oil containing it with high protective and water-displacing properties.

The problem is solved in that the metal corrosion inhibitor, including the condensation product of boric acid with diethanolamine and vegetable oil at a molar ratio of 1: 3: (0.5-0.7), respectively, additionally contains benzotriazole in the following ratio of components, wt.%:

The condensation product of boric acid with diethanolamine and vegetable oil at a molar ratio of 1: 3: (0.5-0.7), respectively 85-95 Benzotriazole 5-15

The problem is also solved by the development of conservation oil based on mineral oil, which contains 17-25 wt.% An inhibitor of the specified composition.

A distinctive feature of the proposed inhibitor is that when a combination of benzotriazole and the condensation product of boric acid with diethanolamine (DEA) and vegetable oil with a molar ratio of 1: 3: (0.5-0.7), a synergistic effect of enhancing the protective properties due to the combination of inhibitors cathodic (condensation product) and anodic (benzotriazole) actions, which allows conservation oil based on it to reliably protect ferrous and non-ferrous metal products from atmospheric corrosion.

With other ratios of the components of the inhibitor, in addition to the stated ones, it is not possible to achieve a synergistic effect of enhancing the protective and water-displacing properties of conservation oil.

The introduction of a corrosion inhibitor in mineral oil in an amount of less than 17 wt.% Does not allow to obtain conservation oil with high protective and water-displacing properties, its introduction of more than 25 wt.% Is impractical, since there is no further increase in the protective properties of conservation oil.

The process of condensation of boric acid with diethanolamine and vegetable oil at other molar ratios of the reagents, in addition to the stated ones, does not allow to obtain a product soluble in mineral oil.

As vegetable oil, use sunflower, linseed or soybean oil.

As a mineral oil - industrial I-20A, I-12A or spindle oil.

A method of obtaining a condensation product of boric acid with DEA and vegetable oil is as follows:

Vegetable oil and DEA are charged into a reactor equipped with a stirrer, a Dean-Stark nozzle, a reflux condenser and a thermometer. The reaction mass is heated with stirring to 90-100 ° C, after which boric acid is introduced and the temperature of the reaction mixture is raised to 180-200 ° C, keeping it at this temperature for 2.0-2.5 hours until a homogeneous mass with amine forms 60-80 mg HCI / g. The molar ratio of boric acid: DEA: vegetable oil is 1: 3: (0.5-0.7).

Benzotriazole - 1,2,3 formulas C ₆ H ₅ N ₃ (TU 6-09-1291-87) is a white crystalline powder with a pink, cream or yellowish tint, melting point 96-99 ° C, the mass fraction of volatile substances is not more than 0.15%.

The proposed inhibitor is prepared by mixing the condensation product and benzotriazole at a temperature of 60-70 ° C for 20-30 minutes

The specific compositions of the atmospheric corrosion inhibitor of metals are given in table 1.

The technology for the preparation of preservation oil is as follows:

In a mineral oil heated to 60-70 ° C in an amount of 75-83 wt.%, 17-25 wt.% Of the obtained inhibitor are introduced. The mixture was stirred at this temperature for 1 hour.

Samples of the compositions of conservation oil are presented in table 2

The anticorrosive effectiveness of the proposed preservation oil samples was determined in accordance with GOST 9.054-78 when testing alloy steel plates of grades 60 C2G and AC 14.

The test results are presented in table.3.

Tests have shown that preservation oil containing the proposed inhibitor:

- has a high penetrating ability, fills cracks, cracks, microdefects of metal surfaces and welds;

- displaces moisture from a metal surface;

- forms a polymolecular protective film;

- impregnates rust and stops the corrosion process developed under it.

The use of preservation oil containing the proposed inhibitor, allows you to reliably protect structures and products from ferrous and non-ferrous metals from atmospheric corrosion.

Table 1. Inhibitor components The content of components, wt.% According to examples one 2 3 four 5 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.5 85 96 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.6 90 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.7 95 84 Benzotriazole fifteen 10 5 four 16

Table 2. Components The content of components in samples of conservation oil, wt.% one 2 3 four 5 The inhibitor of example 1 17 The inhibitor of example 2 21 The inhibitor of example 3 25 The inhibitor of example 4 16 The inhibitor of example 5 26 Mineral oil 83 79 75 76 74

Table 3. Indicators The composition of the samples of conservation oil Prototype one 2 3 four 5 Penetration in the micro-gap between two steel plates (steel 60 C2G), mm: - after 30 minutes 89 91 90 87 89 87 - after 24 hours 98 one hundred 99 96 97 96 Impregnation ability on an iron oxide powder after 2 hours, mm 22 23 21 19 22 eighteen Water displacement on a steel circle, mm d1 78 80 79 75 77 75 d2 73 75 74 70 73 70 d3 73 75 73 70 72 70 Efficiency of displacing a 3% solution of NACl from a steel surface (Art. 60 C2G) after 48 hours: - diameter of the spot composition, mm thirty thirty thirty 31 thirty 32 -% corrosion under the stain 0 0 0 one 0 10 several points surface darkening % of the surface affected by corrosion after 21 days in a salt fog chamber 0 0 0 0 0 10 pitting corrosion pitting corrosion

Claims (2)

1. A metal corrosion inhibitor, including the condensation product of boric acid with diethanolamine and vegetable oil with a molar ratio of 1: 3: (0.5-0.7), respectively, characterized in that it additionally contains benzotriazole in the following ratio of components, wt.% : The condensation product of boric acid with diethanolamine and vegetable oil 85-95 Benzotriazole 5-15 2. Preservation oil based on mineral oil, characterized in that it contains 17-25 wt.% The inhibitor according to claim 1.