RU2301285C1 - The combined inhibitor for protection of the metals against the atmospheric corrosion - Google Patents

Abstract

FIELD: chemical industry; metallurgy industry, other industries; production of the combined inhibitors for protection of the metals against corrosion.

SUBSTANCE: the invention is pertaining to the field of protection of the metals against the atmospheric corrosion by means of the inhibitor and may be used for the long-time conservation of the metalwares and the products made out of the ferrous metals. The inhibitor contains (in mass %): the product of condensation of the boric acid with diethanolamine and the vegetable oil at their molar ratio 0f 1:3:(0.5-0.7) accordingly- 5-6, the soap stock of the vegetable oil or the oleic acid - 10-15 and the mineral oil - up to 100. The technical result of the invention is - extension of the set of the domestic inhibitors for treatment of the atmospheric corrosion, the increased corrosion resistance of the products made out of the ferrous metals, including - the alloyed steels, and salvaging of the wastes of the vegetable oils production.

EFFECT: the invention ensures the extended list of the domestic inhibitors used for treatment of the atmospheric corrosion effect, the increased corrosion resistance of the products made out of the ferrous metals including the alloyed steels, and salvaging of the wastes of the vegetable oils production.

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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 conservation of metal structures and products from ferrous metals.

Known combined metal corrosion inhibitor containing, wt.%: Oleic acid 5-7, boric acid 0.5-0.8, diethanolamine 0.3-0.7, triethanolamine 1.5-3, benzotriazole 1-3, oxidized petrolatum 2-4, industrial oil up to 100 (RU 2232794 C1, class C10M 141/06. 07.20.2004).

A disadvantage of the known combined inhibitor is its multicomponent nature and relatively low colloidal stability.

The closest analogue of the proposed technical solution is a combined metal corrosion inhibitor, including, wt.%: The condensation product of boric acid with diethanolamine and vegetable oil with a molar ratio of reactants 1: 3: (0.5-0.7) 10-16 and mineral oil up to 100 (RU 2263160 C1, class C23F 11/14, 10.27.2005).

The disadvantage of this inhibitor is that it does not protect alloy steel products from atmospheric corrosion.

The technical result of the invention is to expand the range of domestic inhibitors of atmospheric corrosion of metals, increase the corrosion resistance of ferrous metal products, including alloy steel, and utilize waste from the production of vegetable oils.

This result is achieved in that the combined metal corrosion inhibitor, including the condensation product of boric acid with diethanolamine and vegetable oil with their molar ratio of 1: 3: (0.5-0.7), respectively, and mineral oil, additionally contains co-stock of vegetable oil or oleic acid in the following ratio of components, wt.%:

Boric Acid Condensation Product with diethanolamine and vegetable oil at a molar ratio 1: 3: (0.5-0.7) respectively 5-6 Soapstock or oleic acid 10-15 Mineral oil up to 100

A distinctive feature of the proposed inhibitor is that when soap stock of vegetable oil or oleic acid is introduced into it, a synergistic effect arises of enhancing the protective properties of the composition by creating multilayer chemisorption-adsorption films on the metal surface.

With other ratios of the components of the inhibitor, in addition to the claimed, it is not possible to achieve a synergistic effect of enhancing its protective properties.

In the process of obtaining vegetable oils, their storage, some breakdown of fats occurs with the formation of glycerin and free fatty acids. The latter are undesirable in oils, therefore, in the process of refining (neutralization with an alkali solution at 70-95 ° C) they are removed from the oils in the form of the so-called soap stock.

Soapstock contains salts of fatty acids 18-20%, phosphatides 25-30%, proteins and products of their alkaline hydrolysis, dyes (collectively 1.5-2%), water 44.5-52%.

To isolate the fatty part, which is almost completely free of water, the stock is treated with sulfuric acid.

Soapstock (TU 10-04-02-80-91) is a homogeneous ointment of light brown color, with a density of 0.982-0.994 g / cm ³ at 20 ° C, insoluble in water, flash point 240 ° C, melting point 42 ° C non toxic.

Oleic acid of the formula CH ₃ (CH ₂ ) ₇ CH = CH (CH ₂ ) ₇ COOH is produced according to TU 10-04-02-82-91 and has the following characteristics:

mass fraction of fatty acids in anhydrous product,% not less than 92 mass fraction of unsaponifiable substances,% no more than 6.5 moisture content, % no more than 2.0% pour point, ° C no more than 34 acid number, mg KOH / g not less than 175 saponification number, mg KOH / g 175-210 iodine value J g _2/100 g 95-140

The technology for producing the condensation product of boric acid with diethanolamine (DEA) and vegetable oil is as follows.

Vegetable oil and DEA are charged into a reactor equipped with a Dean-Stark nozzle, stirrer, reflux condenser and 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 number 60-80 mg HCl / g. The molar ratio of boric acid: DEA: vegetable oil is 1: 3: (0.5-0.7), respectively.

The process of condensation of boric acid with DEA and vegetable oil with other molar ratios of the reagents, in addition to the stated, 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.

To prepare the proposed inhibitor, 10-15% by weight of soap stock or oleic acid is introduced into a mineral oil heated to 60-70 ° C, then 5-6% by weight of the condensation product of boric acid with DEA and vegetable oil. The resulting mixture was stirred at the indicated temperature for 1 hour.

The specific compositions of the combined atmospheric metal corrosion inhibitor are given in Tables 1 and 2.

Qualitative indicators of the obtained inhibitors in comparison with the inhibitor of the prototype are presented in table.3.

The anticorrosive effectiveness of the proposed inhibitor was determined according to GOST 9.054-78 when testing alloy steel plates of grades 60 C2G and AC 14.

Tests have shown that the proposed combined 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 the proposed combined inhibitor allows you to reliably protect structures and products made of ferrous metals, including alloy steel, against 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 5,0 4,5 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.6 5.5 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.7 6.0 6.5 Soap Stock Vegetable Oil 15.0 12.5 10.0 9.5 15,5 Mineral oil 80.0 82.0 84.0 86.0 78.0

table 2 Inhibitor components The content of components, wt.% According to examples 6 7 8 9 10 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.5 5,0 4,5 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.6 5.5 The condensation product of boric acid with DEA and vegetable oil at a molar ratio of 1: 3: 0.7 6.0 6.5 Oleic acid 15.0 12.5 10.0 9.5 15,5 Mineral oil 80.0 82.0 84.0 86.0 78.0

Table 3 Indicators Examples Prototype one 2 3 four 5 6 7 8 9 10 Penetration in the micro-gap between two steel (60 C2G) plates, mm: - after 30 minutes 92 94 93 89 92 90 92 91 87 92 87 - after 24 hours one hundred 102 103 98 99 one hundred 101 102 96 one hundred 96 Impregnation ability on an iron oxide powder after 2 hours, mm 23 22 21 19 22 24 23 21 twenty 23 eighteen Water displacement on a steel circle, mm d1 82 84 83 76 82 83 85 84 77 84 75 d2 76 79 80 71 78 77 80 81 72 80 70 d3 75 77 78 70 75 75 77 77 70 76 70 Efficiency of displacing a 3% solution of NaCl from a steel surface (st. 60 C2G) after 48 hours: - diameter of the spot composition, mm 28 26 27 thirty 27 28 26 27 thirty 27 thirty -% corrosion under the stain 0 0 0 0 0 0 0 0 0 0 10 Time to corrosion during testing in a G-4 thermal moisture chamber, hours > 400 > 400 > 400 300 400 > 400 > 400 > 400 300 400 158

Claims (1)

Combined 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, and mineral oil, characterized in that it additionally contains co-stock of vegetable oil or oleic acid in the following ratio of components, wt.%: Boric Acid Condensation Product with diethanolamine and vegetable oil with a molar ratio of 1: 3: (0.5-0.7) 5-6 Soapstock or oleic acid 10-15 Mineral oil Up to 100