RU2621940C2 - Protective composition for protecting hydraulic drives of braking systems from corrosion - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a protective conservation materials for anti-corrosion protection of metal products from environmental impact. The composition contains brake fluid "Tom'" and corrosion inhibitor. As a corrosion inhibitor, it contains 3.5-dinitrobenzoat piperidine from more 1.5 up to 3.0 wt %.

EFFECT: increasing the protective capacity of brake fluids with maintaining adequate levels of anti-corrosion protection.

4 tbl

Description

The invention relates to protective preservation materials for anticorrosive protection of metal products from environmental influences, in particular brake systems of vehicles with hydraulic drive.

A wide range of brake fluids is known, such as Neva, Tom, Dew, etc. (V. M. Shkolnikov. Fuels, lubricants and technical fluids. - M.: Techinform, 1999. - S. 221-223) [1]. These fluids are used both for working for brake systems of vehicles with a hydraulic drive, and for temporary anticorrosive protection of internal cavities of hydraulic drives of brake systems from environmental factors during storage (TI Bogdanova. Inhibited oil compositions for corrosion protection. - M .: Chemistry, 1984. - S. 157-159) [2].

A common disadvantage of these liquids is the lack of protective effectiveness under conditions of constant exposure to atmospheric factors and low service life during storage. The service life of the brake fluid during storage is not more than 3 years (TU 6-01-1276-82. Brake fluid "Tom". General requirements. - M .: Publishing house of standards, 1982) [3].

As a prototype selected brake fluid "Tom" (TU 6-01-1276-82. Brake fluid "Tom". General requirements. - M .: Publishing house of standards, 1982) [3]. The Tom fluid is used as brake fluid for brake systems with a hydraulic drive and is the main brake fluid for the hydraulic drive of the brake system of vehicles of the Ural family. "Tom" brake fluid is a composition based on ethyl carbitol and boron-containing polyester, containing thickening and anti-corrosion additives. It has good compatibility with rubber products.

The technical result is an increase in the protective ability of brake fluids while maintaining a sufficient level of corrosion protection.

The technical result is achieved due to the fact that the composition contains a brake fluid "Tom" and a corrosion inhibitor, while as a corrosion inhibitor it contains 3,5-dinitrobenzoate piperidine in an amount of from more than 1.5 to 3.0 wt.%.

The composition is prepared as follows. Piperidine 3,5-dinitrobenzoate inhibitor powder (3,5-dinitrobenzoic acid piperidine salt) in the specified proportions is added to the brake fluid with constant stirring. The composition is poured into the hydraulic drives of the brake systems of cars.

The introduction of a complex corrosion inhibitor into the brake fluid, which inhibits both the cathodic and anodic processes, can increase the effectiveness of corrosion protection (T.I. Bogdanova. Inhibited oil compositions for corrosion protection. - M .: Chemistry, 1984. - P. 157 -159) [2]. The composition allows to protect steel, iron and alloys, copper, aluminum and their alloys.

In the laboratory, the anticorrosion properties of a number of corrosion inhibitors listed in Table 1 were investigated.

To determine the optimal working concentrations, potentiostatic measurements were performed. Anodic potentiostatic characteristics were recorded on a PI-50-1 potentiostat. Steel working materials were used.

According to the data given in table 2, the optimal concentrations are for "P-4" - from more than 1.5 to 3.0 wt.%.

Upon receipt of the static potential, Table 2 indicates that the addition of piperidine 3,5-dinitrobenzoate (piperidine salt of 3,5-dinitrobenzoic acid) to the Tom brake fluid is 0.1; 0.2; 0.3; 0.4 wt.% Is unacceptable due to deep pitting lesions of the metal surface. The optimal ratio for the use of piperidine 3,5-dinitrobenzoate (3,5-dinitrobenzoic acid piperidine salt) in the Tom brake fluid is a concentration of more than 1.5 to 3.0 wt.%, At which the surface of the samples is clean. The composition allows to increase corrosion protection under conditions of constant exposure to atmospheric factors.

The optimal ratio of composition: wt.%

inhibitor from more than 1.5 to 3.0 brake fluid "Tom" rest

Accelerated laboratory tests (GOST-9.054-75. ESKZ. Preservation oils, greases and thin-film oil coatings. Accelerated test methods. - M: Standards Publishing House, 1975 [4] made it possible to clarify the optimal composition of the protective composition. The data are given in tables 3.1, 3.2 , 3.3.

The results of comparative tests of the protective materials listed in Tables 3.1, 3.2, and 3.3 indicate that the Tom brake fluid under storage conditions has insufficient operational properties, a significant decrease in its protective function is observed, and the plate actively begins to corrode.

The area of corrosion damage reaches 100%: for steel 3600 hours (table 3.1, experiment 10); for copper 4320 hours (table 3.2, experiment 10); for cast iron in 2880 hours (table 3.3, experiment 10).

The composition of the following material showed good protective ability: piperidine 3,5-dinitrobenzoate (3,5-dinitrobenzoic acid piperidine salt) with a concentration of more than 1.5 to 3.0 wt.%. The area of corrosion damage is: for steel 33% (table 3.1, experiment 3), for copper 27% (table 3.2, experiment 3), for cast iron 41% (table 3.3, experiment 3). At the same time, during the entire test period, a small percentage of corrosion damage to the metal surface under the protective material layer, including the damaged area, was observed.

Changes in the state of the protective material after being under the film during the test time were not detected.

The calculation carried out in accordance with the methodology showed that the protective composition allows to increase corrosion protection under conditions of constant exposure to atmospheric factors from 6 to 8 years.

The unique combination of physicochemical properties of P-4 with low toxicity, relative simplicity of its preparation, availability of raw materials and low cost confirms the possibility of using the above composition.

The P-4 inhibitor (piperidine 3,5-dinitrobenzoate) is a crystalline substance from white to light yellow in color. Melting point not lower than 192 ° C. It is soluble in water, slightly soluble in acetone. Solubility in water 3.7 g / 100 ml at 25 ° C, 52 g / 100 ml at 70 ° C.

Additional information in table 4

The temperature of the onset of intense decomposition of T _nir is 285 ° C.

The P-4 inhibitor protects all ferrous and non-ferrous metals, with the exception of magnesium, without affecting rubber and plastic. The P-4 inhibitor can be used to protect products of the machine-tool and machine-building industries, spare parts, products of the radio engineering, electronic, optical, instrument-making and other industries.

According to toxicity, according to GOST 12.1.007-76, the inhibitor "P-4" belongs to class 3 - moderately dangerous.

Literature:

1. Shkolnikov V.M. Fuels, lubricants and technical fluids. [Text]: reference book / V.M. Schoolchildren. - M.: Techinform, 1999 .-- S. 221-223.

2. Bogdanova T.I. Inhibited petroleum compositions for corrosion protection [Text] / T.I. Bogdanova. - M.: Chemistry, 1984. - S. 157-159.

3. TU 6-01-1276-82. Brake fluid "Tom". General requirements [Text]. - M .: Publishing house of standards, 1982.

4. GOST-9.054-75. ESCZ. Preservation oils, greases and thin-film oil coatings. Accelerated Test Methods [Text]. - M .: Publishing house of standards, 1975.

Claims (1)

Composition for protecting hydraulic brake actuators against corrosion, containing Tom brake fluid and a corrosion inhibitor, characterized in that it contains piperidine 3,5-dinitrobenzoate in an amount of more than 1.5 to 3.0 wt.% As a corrosion inhibitor .