RU2818565C1 - Bitumen anticorrosion composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to bitumen compositions and can be used to protect agricultural machinery and equipment from atmospheric corrosion. Bitumen composition contains bitumen, an organic solvent and a modifying additive, which is represented by still residues of synthetic fatty acids production, taken in the following ratio of initial components, wt.%: bitumen – 30.0–40.0; stillage residues of production of synthetic fatty acids 3–5, organic solvent – the rest.

EFFECT: development of low-component bitumen anticorrosion composition, using production wastes as one of components, wider field of use of the bitumen composition while maintaining high protective efficiency of the proposed composition.

1 cl, 5 tbl, 5 ex

Description

The invention relates to bitumen compositions for producing coatings and can be used to protect agricultural machinery and equipment from atmospheric corrosion.

Bitumen compounds protect the outer surfaces of the working parts of agricultural machines (mouldboards, plowshares, cultivator shares, discs of seeders, ploughshares, etc.) from corrosion. The protective period of common gasoline-bitumen coatings when storing units and parts of agricultural machinery in open areas is up to a year. Protective effectiveness largely depends on the condition of the surface. The remaining rust, as well as moisture and atmospheric oxygen penetrating through the bitumen coating, cause an increase in corrosion damage to the steel, the greatest in the first two months. One of the most effective ways to increase the protective properties and service life of bitumen-based coatings is to introduce corrosion inhibitors into their composition. The optimal content of most inhibitors (petroleum sulfonates, nitrated oils, oxidized petroleum products, amines and their salts with synthetic fatty acids) in bitumen mastics is 3-5%. (Mironov E.B., Kosolapov V.V., Tarukin E.M., Maslov M.M. Evaluation of conservation materials for protection against corrosion of working parts of agricultural machinery / Bulletin of NGIEI. 2015 - P. 45-57)

To improve the physicochemical properties of bitumen coatings, various modifying additives are used: rubbers, oils, rubbers, polyolefins, inhibitors, etc. (The use of bitumen-based materials as a corrosion-resistant coating in the chemical industry. NIITEKHIM, Moscow, 1985 / [Compiled by A.A. Kozlov et al.]. - Moscow: NIITEKHIM, 1985. - 55 p.).

A known bitumen composition contains the corrosion inhibitor additive AKOR-1, which is a calcium salt of nitrated oil and stearic acid in the oil (Zashchita Metallov, 1981, vol. XVII, No. 4, pp. 452-454). The disadvantages of this composition are low hydrophobic and protective properties.

The author's certificate of the USSR SU No. 1746697 A1, published on June 27, 1997, IPC C09D 195/00 (2006.01), C09D 191/00 (2006.01), “Anti-corrosion protective composition” describes an anti-corrosion composition, including, by weight. %: bitumen 25-50, modifier - rope lubricant 40-50, which is an alloy, wt. % 40 nigrol, 25% tar, 20% petroleum ceresin and 15% the product of the interaction of synthetic fatty acids above _C20 with triethanolamine, asbestos filler - the rest. The RF patent No. 2044020 C1, published on September 20, 1995 “Composition for coating”, MPK S09D 195/00, proposes a composition that contains bitumen, asbestos, maleic or phthalic anhydride, monohydric primary alcohol, waste resin from the production of toluene hydromethylation in the presence of hydrogen. In the RF patent No. 2044021, published on September 20, 1995, “Method of obtaining an anti-corrosion composition”, MPK S09D 195/00 for the protection of metal surfaces, in particular the underbody of a car, the composition consists of bitumen, catalyst dust - waste of a catalyst for catalytic cracking of petroleum fractions, petroleum solvent - straight-run petroleum fraction with a boiling point of 85-120°C, a mixture of rubber crumb and high-boiling solvent (flavored catalytic cracking fraction or dewaxed straight-run petroleum fraction). In RF patent No. 2439422 C1, published on January 10, 2012 “Mastic bitumen-polymer composition for anti-corrosion coatings and a method for its production”, IPC F16L 58/12; C08L 195/00, a well-known corrosion protection composition consists of a mixture of bitumen, elastomer, thermoplastic elastomer, corrosion inhibitor (polyethylene polyamine) and plasticizer (sulfonated tall oil). The disadvantages of all these compositions are the multicomponent nature, difficulty in obtaining and scarcity of components. Although all of these compositions are claimed to be anti-corrosion, quantitative values of the protective effectiveness of the coatings are not given in the examples.

There are known preliminary patents of Kazakhstan No. 13031, No. 13032, No. 13033 (“Bitumen mastic”, MPK C09D 195/00, C09D 197/00), published on May 15, 2003, for bitumen mastics for protection against underground and atmospheric corrosion of oil and gas -, product pipelines, where ash, lignin and heavy pyrolysis resin (No. 13031), lignin, limestone and diesel fuel (No. 13032), crumb rubber, lignin, industrial oil (No. 13033) are used as fillers. The fillers used increase the thickness of coatings, softening point, thermal stability, and improve elongation. The disadvantages of all these compositions are their complex composition and insufficiently high protective effectiveness.

The closest in technical essence and achieved result is the bitumen composition (RF Patent No. 2140951 C1, published on November 10, 1999 “Bitumen composition” MPK S09D 195/00), containing bitumen wt.% 35.0-65.0, modifying additive - nonionic surfactant 3.6-7.0, solvent - the rest. The disadvantage of the composition is the multi-stage and duration of the process of preparing the composition, the complexity of preparing the modifying additive (obtaining it in laboratory conditions when heated to 80-90 ° C in an oil bath with reflux in small quantities). One of the starting components for the synthesis of the additive is a mixture of alkylpyridines obtained by vacuum distillation of a fraction of light dialkylpyridines from higher synthetic pyridine bases (inhibitor I-1-A, TU 38.103246-87).

The objective of the proposed invention is to develop a low-component bitumen anti-corrosion composition, using production waste as one of the components, to expand the scope of use of the bitumen composition while maintaining the high protective effectiveness of the proposed composition.

This task is achieved by the fact that the bitumen anti-corrosion composition containing bitumen, an organic solvent and a modifying additive, according to the invention, uses the bottoms of the production of synthetic fatty acids as a modifying additive in the following ratio of the initial components, mass. %: bitumen - 30.0-40.0; VAT residues from the production of synthetic fatty acids 3-5, organic solvent - the rest.

Example 1. To prepare a bitumen composition, take the required amount of crushed bitumen, add the bottoms of the production of synthetic fatty acids (CO-SFA), an organic solvent and mix thoroughly while heating in a water bath to 30-40°C.

Bottom residues from the production of synthetic fatty acids (CO-SFA) are a mixture of higher fatty acids of fraction C ₂₀ and above, mainly saturated monocarboxylic acids, as well as unsaponifiable substances and resinous condensation and polymerization products. White spirit was used as an organic solvent (the use of another organic solvent is allowed).

The compositions were prepared, mass. %:

I - bitumen - 30, KO-SZhK - 3, white spirit - 67;

II - bitumen - 30, KO-SZhK - 5, white spirit - 65;

III - bitumen - 40, KO-SZhK - 3, white spirit - 57;

IV - bitumen - 40, KO-SZhK - 5, white spirit - 55;

Preservation of agricultural machinery is carried out in late autumn at low temperatures, so the compositions were tested for frost resistance. The compositions were frozen in a freezer (temperature up to minus 20 ± 2) ° C in polyethylene containers with a volume of 200 ml and applied as a coating in 2 layers on steel plates (after drying at room temperature) for 8 hours, then for 16 hours defrosted, number of cycles - 5. No changes (formation of lumps, delamination) after testing in the volume of the composition were observed, as well as cracking of coatings on steel.

Example 2. Table 1 presents the physicochemical properties of films obtained from prepared compositions I-IV and the prototype on St3 steel. All coatings applied with our proposed composition and the prototype composition dry to degree 3 within 24 hours (the degree of drying was determined according to GOST 31740-2012). The introduction of KO-SZhK improves the adhesion of the bitumen composition we propose, increases the hydrophobic properties (the contact angle increases).

Example 3. Table 2 shows the results of corrosion tests in a thermal and moisture chamber G-4 according to GOST 9.054-75. Coated samples were installed in a thermal and moisture chamber above a layer of water at 40°C. The tests were carried out over the course of a day, with 10 hours at 40°C and 14 hours at room temperature 17-21°C and for 40-56 days. Control was carried out both visually, based on the appearance of the film, and gravimetrically.

Example 4. Table 3 shows the results of corrosion tests in a 0.5 M NaCl solution in accordance with GOST 8.042-75. The essence of corrosion tests is to keep the coated samples in an electrolyte solution at room temperature. As in the prototype, there were no visible changes in the coating. A quantitative comparison of the protective effectiveness of our proposed composition and the prototype is not possible due to the lack of data in the prototype.

Full-scale bench tests in atmospheric conditions in accordance with GOST 9.909-86 showed the high protective effectiveness of the proposed bitumen anti-corrosion composition.

Example 5.

The proposed bitumen anti-corrosion composition protects steel surfaces in saturated solutions of mineral fertilizers: thiourea, ammonium nitrate, urea, borophosphate, superphosphate. During 14 days of exposure at room temperature in all solutions, no changes in the coating films were visually observed.

From the test results it follows:

1. The physico-chemical properties of films obtained on the basis of the proposed composition are higher than the physico-chemical properties of films obtained on the basis of the prototype (Table 1). Compositions with KO-SZhK are frost-resistant. Adhesion is respectively 1 point for compositions with KO-SZhK and 1 point for the prototype. Hydrophobic properties increase (contact angles increase).

2. The protective effectiveness of coatings of the proposed composition when tested in a G4 thermal and moisture chamber (Table 2) and in an electrolyte solution of 0.5 M NaCl solution (Table 3) is significantly higher than that of the prototype. After testing in an electrolyte solution, the surface contact angle decreases, which indicates an increase in hydrophilic properties.

3. The developed compositions show high weather resistance.

4. Compositions with KO-SZhK well protect steel surfaces in saturated solutions of mineral fertilizers: thiourea, ammonium nitrate, urea, borophosphate, superphosphate for 14 days of exposure at room temperature without changes in the structure of coating films.

Thus, the preparation of a bitumen anti-corrosion composition is simplified while maintaining its high protective efficiency, and the possibilities for using the proposed composition not only in atmospheric conditions, but also in aggressive environments of mineral fertilizers, are expanded.

Claims (1)

A bitumen anti-corrosion composition containing bitumen, an organic solvent and a modifying additive, characterized in that vat residues from the production of synthetic fatty acids are used as a modifying additive in the following ratio of initial components, wt.%: bitumen - 30.0-40.0; VAT residues from the production of synthetic fatty acids 3-5, organic solvent - the rest.