RU2535087C1 - Method of producing polymer complex having antiseptic properties and antiseptic coating based thereon - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method includes forming, on a surface, a coating from a dimethylalkylbenzylammonium chloride complex containing a C₁₀-C₁₄ alkyl group or a mixture of C₈-C₁₆ alkyl groups with a copolymer of styrene and maleic anhydride, which is subjected to preliminary chemical modification to open anhydride rings to form carboxyl groups, 50-60% of which are neutralised to form carboxylate groups, or a mixture of said complex with polyvinyl butyral, in the following ratio, wt %: antiseptic polymer complex 25-40, polyvinyl butyral 60-75.

EFFECT: full prolonged protection of articles made of aluminium alloy from fouling by microorganisms, which prevents corrosive change of the surface of said alloys.

28 ex, 3 tbl

Description

The present invention relates to a technology for the production of polymer coatings, which allows to protect aluminum alloys from the development of microorganisms on their surface.

Most effectively, the invention can be used in objects that are required to meet the level of microbial load.

The relevance of the developed method is determined by the need to use products from aluminum alloys in the presence of people at objects, territories, etc., where the microbial load is regulated, as well as in sealed rooms in which the development of microorganisms on the surface of materials from aluminum alloys is not allowed even in conditions of increased humidity.

Polyelectrolyte complexes of catamine AB with polymers containing acid groups are known, in which catamine AB is linked to the macromolecule chain by an ionic bond. In particular, the complex of catamine AB with a copolymer of N-vinylpyrrolidone with crotonic acid [USSR copyright certificate No. 1607359 A1, cl. 6 C08F 226/10, 1995]. This polymer complex containing quaternary ammonium groups with a long chain alkyl substituent as a counterion has a strong antiseptic effect. A similar effect has a complex of catamine AB with carboxymethyl cellulose, proposed [RF patent No. 2146136 C1, class 7 A61K 31/14, 2000] as an antiseptic. However, both of the above complexes are water soluble and cannot be used as a film antiseptic protective coating.

The known method [patent WO 2007/024973 A1, cl. A01N 25/32], where polymethacrylates, polyurethanes, polyvinylbenzyl chloride derivatives and other polymers containing a quaternary ammonium group with a long chain substituent covalently linked to the macromolecule chain are used as antimicrobial coatings. These polymers are not soluble in water, but soluble in alcohols, from the solutions in which a coating can be formed. However, in the monograph [Afinogenov G.E., Panarin E.F. Antimicrobial polymers, St. Petersburg, Hippocrates, 1993, 264 pp.] And review [Panarin EF, Kopeikin VV High molecular weight compounds. Series C, 2002, vol. 44, No. 12, pp. 2340-2351], it has been shown by numerous examples that the antimicrobial properties of polymers containing covalently linked quaternary ammonium groups are lower than the antimicrobial properties of similar model low molecular weight quaternary ammonium compounds and polyelectrolyte complexes of ionogenic surface active substances in which quaternary ammonium groups with a long-chain alkyl substituent are bonded to the polymer backbone by an ionic bond.

The closest in technical essence and the achieved result to the proposed invention is a method [RF patent No. 2445980 C1, Cl. A61L 101/46, 2010] the manufacture of a polymer complex having antiseptic properties and an antiseptic coating based on it, where a mixture of polyvinyl butyral and a complex of dimethylalkylbenzylammonium chloride with a styrene-maleic anhydride copolymer previously chemically modified by reaction with alkali is used as an antimicrobial coating to open anhydride rings to form carboxylate groups. Coatings from a mixture of this complex completely inhibit the growth of microflora. However, a significant drawback of this coating is its interaction with the surface of the aluminum alloy, leading to corrosion of the latter and the appearance of caverns on the surface.

The technical result of the present invention is the complete prolonged protection of aluminum alloy products from fouling by microorganisms, eliminating corrosion changes in the surface of these alloys.

This technical result is achieved by the proposed method of antiseptic processing of aluminum alloys, which consists in the formation on their surfaces of coatings from complexes of dimethylalkylbenzylammonium chloride containing an alkyl group from C ₁₀ to C ₁₄ or their mixtures from C ₈ to C ₁₆ , with styrene-maleic anhydride copolymers previously subjected chemical modification with the disclosure of anhydride cycles during treatment with alkali solutions, the amount of alkali in which varies from 50 to 60% with respect to the amount required . To neutralize all the carboxyl groups are formed, and mixtures of these complexes with polyvinyl butyral composition, wt%: Complex - 25-40; polyvinyl butyral - 60-75.

Coatings were formed on samples of aluminum alloy plates, the surfaces of which were previously wiped with a flannel napkin or a cotton-gauze swab dipped in ethyl or isopropyl alcohol. Solutions for coating formation were applied with a brush and evenly distributed over the surface of the sample. The operation was repeated three times. After each application, the coating was dried in air. In the case of the formation of coatings from mixtures of polyvinyl butyral with complexes, solutions for the formation of coatings were prepared by mixing the complex solution with a solution of polyvinyl butyral in a predetermined ratio, followed by mixing the resulting solutions with a magnetic stirrer until a homogeneous mass was obtained.

Chemical modification of the styrene-maleic anhydride copolymer in order to open the anhydride rings in the units of maleic anhydride with the formation of carboxylate and carboxyl groups was carried out with aqueous alkali solutions. To do this, in a flat-bottomed flask equipped with a reflux condenser and a magnetic stirrer, the calculated quantities of the copolymer and an aqueous solution of alkali metal hydroxide were loaded. The process was conducted in a boiling water bath, as a result of which the entire copolymer passed into solution. To obtain a complex with dimethylalkylbenzylammonium halide, this solution of a chemically modified copolymer was mixed with vigorous stirring with an aqueous solution of dimethylalkylbenzylammonium halide. The latter was taken in the reaction at the rate of 1 mol per 1 g · equiv. carboxylate groups in a chemically modified copolymer. The complex was isolated from the solution in the form of a white precipitate, which was washed with water and dried in vacuum at a temperature of 40 ° C.

Coatings were formed from solutions of polymer complexes or mixtures thereof with polyvinyl butyral in an appropriate solvent. The solutions were applied with a brush in several layers, drying after applying each layer.

When checking the antimicrobial activity of coatings, their fungicidal and bactericidal properties were determined by the duration and degree of protection of the aluminum alloy under conditions of periodically created high microbial load. Evaluation of the antimicrobial activity of the samples was carried out by determining the fungus resistance in points according to GOST 9.050-75 method A and in relation to the bacterial-fungal association, which was prepared in Chapek-Doks medium diluted with distilled water in a ratio of 1: 5. The culture association consisted of Staphylococcus epidermidis, Bacillus polymyxa, Bacillus pumilus, Penicillium expansum, Aspergillus niger and Cladosporium cladosporioides, which were inoculated 5 samples per month for each experiment to obtain reliable data. The content of each type of microorganism in the mixture was (1-2) × 10 ⁵ colony forming units (CFU) per 1 cm ² area. The infected samples were placed in a thermostat and incubated at 28 ° C and relative humidity ≥90% for 3 months with sampling after 90 days to determine the number of viable units of microorganisms on the studied materials. To do this, the samples were shaken off in physiological saline and the washings were plated on the surface of nutrient media: Chapek-Doks medium for determination of CFU of fungi, TCA medium (trypto-soy agar) for determination of CFU of bacteria.

The quality of the surface with the formed coating and its corrosion changes were evaluated using a Stemi 2000 stereo microscope.

The following examples illustrate the proposed method of manufacturing a polymer complex and an antiseptic coating on aluminum alloys.

Example 1. To obtain a copolymer of styrene with maleic anhydride, the copolymerization was carried out in boiling benzene in a 3-neck round-bottom flask equipped with a mechanical stirrer, reflux condenser and thermometer. Loading: benzene - 509 ml, maleic anhydride - 49 g (0.5 mol), styrene - 52 g (57.4 ml, 0.5 mol), initiator 2,2'-azobis (isobutyronitrile) - 0.5 g Benzene was preliminarily dried by incubation over calcined alumina, styrene was purified from the inhibitor using potassium hydroxide and dried with calcium chloride. In the copolymerization process, the copolymer was isolated as a white solid precipitate. At the end of the process (20 min), the copolymer was separated from the solution on a Buchner funnel, washed three times with fresh portions of hexane and dried in a vacuum oven at a temperature of 80 ° C. The viscosity average molecular weight of the copolymer is 3.2 × 10 ⁵ . According to titration and elemental analysis, the copolymer contains 53 mol% units of maleic anhydride units.

To obtain a modified copolymer, in which 60% of maleic anhydride groups are converted to carboxylate groups, the modification was carried out with an aqueous solution of sodium hydroxide. To do this, 2.08 g (10.9 mmol of maleic anhydride unit) of the copolymer and 0.525 g (13.1 mmol) of sodium hydroxide dissolved in 50 ml of water were charged into a flat-bottomed flask equipped with a reflux condenser and a magnetic stirrer. The process was conducted in a boiling water bath for 5 hours. At the end of the process, the entire copolymer passed into the solution, the pH of this solution of the modified copolymer was 8. From the solution, the copolymer was precipitated with 1,4-dioxane, separated from the solution on the filter and dried in vacuum at room temperature. From this modified copolymer, a complex with catamine AB (dimethylalkyl (C _12-14 ) benzylammonium chloride) was obtained. For this, 10.58 ml of a 14.85% aqueous solution of catamine AB was added dropwise to 20.0 ml of a 4.18% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of catamine AB. The precipitated white precipitate of the complex was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (concentration - 4.84 g / dl).

To assess the antimicrobial activity of the resulting coating, aluminum alloy samples were 3 times infected with the bacterial-fungal association. Table 1 shows the CFU content of bacteria and fungi of these samples and prototype samples. As a control, uncoated aluminum alloy samples were used.

Table 1 The content of bacteria and fungi (CFU) according to example 1, on the prototype sample and the control sample without coating and the characteristic of these surfaces Example No. 3x infection Surface characteristics at the end of the test bacteria mushrooms one 0 ∗ 0 ∗ smooth prototype 0 ∗ 0 ∗ there are caverns the control 5.0 × 10 ⁷ 3.2 × 10 ⁵ smooth Note: 0 ∗ - CFU content - less than 50 per sample with 3-fold repetition of samples

As can be seen from the data in this table, the number of microorganisms at 3-fold infection in the samples of example 1 and the prototype sample is significantly lower than in the control samples. The mushroom resistance of the samples according to GOST 9.050-75 corresponds to: according to example 1 and the prototype is 0 points, and the control sample is 4 points. The surfaces of the samples of example 1 and the control sample without coating are smooth, on the surface of the prototype sample there are pits.

Example 2. Coatings on Amg6 aluminum alloy plates were formed from a mixture of solutions in isopropyl alcohol of the complex synthesized as described in Example 1 and polyvinyl butyral of the Mowital B60T brand containing 69-72 wt.% Acetal units, 2 wt.% Acetate units and 24-27 wt.% residual units of vinyl alcohol. This mixture of solutions was prepared by mixing 2 volumes of a complex solution (concentration - 4.84 g / dl) and 3 volumes of a Mowital B60T brand polyvinyl butyral solution (concentration - 5.09 g / dl). The content of the complex in the coating is 39%.

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Example 3. A styrene-maleic anhydride copolymer was prepared as described in Example 1. To obtain a modified copolymer in which 50% of the maleic anhydride groups were converted to carboxylate groups, 2.62 g (13 g) were charged into a flat-bottomed flask equipped with a reflux condenser and a magnetic stirrer. , 77 mmol unit of maleic anhydride) copolymer; and 0.551 g (13.77 mmol) of sodium hydroxide dissolved in 50 ml of water. The process was conducted in a boiling water bath for 12 hours. At the end of the process, the entire copolymer passed into the solution, the pH of this solution of the modified copolymer is 6. From the solution, the copolymer was precipitated with 1,4-dioxane, separated from the solution on the filter and dried in vacuum at room temperature to constant weight. A complex with catamine AB was obtained from this saponified copolymer. For this, 10.15 ml of a 14.81% aqueous solution of catamine AB was added dropwise to 20.0 ml of a 4.72% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of catamine AB. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (concentration - 4.3 g / dl).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Example 4. The synthesis of a copolymer of styrene with maleic anhydride and its modification with sodium hydroxide was carried out as described in example 1. From this saponified copolymer, a complex with dimethylalkyl (C _8-16 ) benzylammonium chloride was obtained. For this, 5.8 ml of a 15.0% aqueous solution of dimethylalkyl (C _8-16 ) benzylammonium chloride was added dropwise to a 12.0 ml of a 4.18% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of dimethylalkyl (C _8-16 ) benzylammonium chloride. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (5.1 g / dl concentration).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection. The surface of the samples at the end of the test is smooth.

Example 5. Coatings on Amg6 aluminum alloy plates were formed from a mixture of solutions in isopropyl alcohol of the complex synthesized as described in Example 4 and polyvinyl butyral of the Mowital B60T brand. This mixture of solutions was prepared by mixing 2 volumes of a solution of the complex (concentration 5.1 g / dl) and 3 volumes of a solution of polyvinyl butyral (concentration 5.09 g / dl). The content of the complex in the coating is 40%.

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Example 6. The synthesis of a copolymer of styrene with maleic anhydride and its modification with sodium hydroxide was carried out as described in example 1. From this saponified copolymer, a complex with dimethylhexadecylbenzylammonium chloride was obtained. To this end, 1.15 g of dimethylhexadecylbenzylammonium chloride dissolved in 20 ml of hot (50-60 ° C) distilled water was added to 13.0 ml of a 4.18% aqueous solution of the modified copolymer with magnetic stirring. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of dimethylhexadecylbenzylammonium chloride. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (concentration - 5.0 g / dl).

On the coatings thus formed, fungal growth was observed. According to GOST 9.050-75, after 2 months, it corresponded to 2-3 points. With a 2-fold infection of this coating, CFU of fungi corresponded to 1.6 × 10 ⁵ , and CFU of bacteria - 3.2 × 10 ³ .

The surface of the samples at the end of the test is smooth.

Example 7. Coatings on Amg6 aluminum alloy plates were formed from a mixture of solutions in isopropyl alcohol of the complex synthesized as described in Example 6 and polyvinyl butyral of the Mowital B60T brand. This mixture of solutions was prepared by mixing 2 volumes of a solution of the complex (concentration - 5.0 g / dl) and 3 volumes of a solution of polyvinyl butyral (concentration - 5.09 g / dl). The complex content in the coating is 40%.

On the coatings thus formed, fungal growth was observed. According to GOST 9.050-75, after 1 month, it corresponded to 1-2 points. With a 1-fold infection of this coating, CFU of fungi corresponded to 5.4 × 10 ² , and CFU of bacteria - 2.6 × 10 ³ .

The surface of the samples at the end of the test is smooth.

Example 8. The synthesis of a copolymer of styrene with maleic anhydride and its modification with sodium hydroxide was carried out as described in example 1. From this saponified copolymer, a complex with dimethyloctylbenzylammonium chloride was obtained. For this, 12.71 ml of a 7.75% aqueous solution of dimethyloctylbenzylammonium chloride was added dropwise to 15.0 ml of a 4.1% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of dimethyloctylbenzylammonium chloride. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on aluminum alloy plates were formed from a solution in methyl alcohol (concentration - 5.0 g / dl).

On the coatings thus formed, fungal growth was observed. According to GOST 9.050-75, after 1 month, it corresponded to 2-3 points. With a 1-fold infection of this coating, CFU of fungi corresponded to 2.4 × 10 ⁵ , and CFU of bacteria - 4.8 × 10 ⁴ .

The surface of the samples at the end of the test is smooth.

Example 9. Coatings on Amg6 aluminum alloy plates were formed from a mixture of solutions in the methyl alcohol of the complex synthesized as described in Example 8 and polyvinyl butyral of the Mowital B60T brand. This mixture of solutions was prepared by mixing 2 volumes of a solution of the complex (concentration - 5.0 g / dl) and 3 volumes of a solution of polyvinyl butyral (concentration 5.09 g / dl). The complex content in the coating is 40%.

On the coatings thus formed, fungal growth was observed. According to GOST 9.050-75, after 1 month there was no growth of mushrooms, for 2 months it corresponded to 3 points. With a 2-fold infection of this coating, CFU of fungi corresponded to 1.0 × 10 ⁶ , and CFU of bacteria - 3.2 × 10 ⁴ .

The surface of the samples at the end of the test is smooth.

Example 10. A styrene-maleic anhydride copolymer was prepared as described in Example 1. To obtain a modified copolymer, in which 80% of maleic anhydride groups were converted into carboxylate groups, a 2.15 g load was charged into a flat-bottomed flask equipped with a reflux condenser and a magnetic stirrer (11, 3 mmol unit of maleic anhydride) copolymer and 0.72 g (18.10 mmol) of sodium hydroxide dissolved in 50 ml of water. The process was conducted in a boiling water bath for 4 hours. At the end of the process, the entire copolymer passed into the solution from which it was precipitated with 1,4-dioxane, separated from the solution on the filter and dried in vacuo at room temperature to constant weight, the pH of the aqueous solution of this modified copolymer was 11. From this saponified copolymer was obtained complex with catamine AB. For this, 15.81 ml of a 14.85% aqueous solution of catamine AB was added dropwise to 20.0 ml of a 4.86% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of catamine AB. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (concentration - 5.28 g / dl).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

After testing, pitting was observed on the surface of the samples.

Example 11. Coatings on wafers made of Amg6 aluminum alloy were formed from a mixture of solutions in isopropyl alcohol of the complex synthesized as described in Example 10 and polyvinyl butyral of the Mowital B60T brand. This mixture of solutions was prepared by mixing 1 volume of the complex solution (concentration - 5.28 g / dl) and 3 volumes of polyvinyl butyral solution (concentration - 5.09 g / dl). The content of the complex in the coating is 26%.

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

After testing, pitting was observed on the surface of the samples.

Example 12. A styrene-maleic anhydride copolymer was prepared as described in Example 1. To obtain a modified copolymer, in which 40% of the maleic anhydride groups were converted to carboxylate groups, 2.07 g (10 g) were charged into a flat-bottomed flask equipped with a reflux condenser and a magnetic stirrer. , 9 mmol unit of maleic anhydride) copolymer and 0.35 g (8.72 mmol) of sodium hydroxide dissolved in 50 ml of water. The process was conducted in a boiling water bath for 24 hours. At the end of the process, the entire copolymer passed into a solution from which it was precipitated with 1,4-dioxane, separated from the solution on the filter and dried in vacuo at room temperature to constant weight, the pH of the aqueous solution of this modified copolymer was 6. From this saponified copolymer was obtained complex with catamine AB. To this end, 29.18 ml of a 2.9% aqueous solution of catamine AB were added dropwise to 20.0 ml of a 3.25% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of catamine AB. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in N, N-dimethylformamide (concentration - 5.0 g / dl). The solution was applied with a brush in 4 layers with an interval of 24 hours. After applying each layer, it was dried at a temperature of 70-80 ° C.

On thus formed coatings there is a growth of mushrooms. According to GOST 9.050-75, after 1 month, the growth of mushrooms corresponded to 5 points. With a 1-fold infection of this coating, CFU of fungi corresponded to 6.0 × 10 ⁷ , and CFU of bacteria - 2.82 × 10 ⁴ .

The surface of the samples at the end of the test is smooth.

Example 13. The copolymerization of styrene with maleic anhydride was carried out in dried methyl ethyl ketone at the boiling point in a 3-necked flask equipped with a mechanical stirrer, reflux condenser with a dropping funnel and a thermometer. Loading: methyl ethyl ketone - 40 ml, maleic anhydride - 9.8 g (0.1 mol), styrene - 10.4 g (11.4 ml, 0.1 mol), initiator 2,2'-azobis (isobutyronitrile) - 0.6 g. For this, a solution of maleic anhydride in methyl ethyl ketone was charged into a 3-necked flask and brought to a boil. To this solution, a solution of initiator in styrene was added dropwise over 40 minutes with vigorous stirring. After which the process was continued for 110 minutes. At the end of the process, the copolymer from the solution was precipitated in the form of a white powder with petroleum ether and separated from the solution on a Buchner funnel, washed three times with fresh portions of petroleum ether and dried in a vacuum oven. According to elemental analysis, the copolymer contains 61 mol% of maleic anhydride units and 39 mol% of styrene units. The viscosity average molecular weight of this copolymer is 2.4 × 10 ⁴ . To obtain a modified copolymer in which 60% of maleic anhydride groups were converted to carboxylate groups, the modification was carried out with an aqueous solution of sodium hydroxide under the same conditions as in Example 1. To do this, 4.47 g (27.15 mmol of maleic unit anhydride) and 1.305 g (32.58 mmol) of sodium hydroxide dissolved in 90 ml of water. The complex of this modified copolymer with catamine AB was also synthesized as described in Example 1. To this end, 12.5 ml of a 7.61% aqueous solution of catamine AB was added dropwise to 10.0 ml of a 5.07% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of catamine AB. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (5.1 g / dl concentration).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Examples 14-17. A copolymer of styrene with maleic anhydride, its derivative modified with sodium hydroxide and a complex with catamine AB were obtained as described in example 1.

Coatings on plates made of Amg6 aluminum alloy were formed from a mixture of solutions in isopropyl alcohol of this complex and Mowital B60T polyvinyl butyral at various ratios of components in the mixture (Table 2).

table 2 The coating compositions of examples 2, 14-17 on plates of aluminum alloy Amg6, the growth of mushrooms in points and the content of bacteria and fungi (CFU) Example No. The composition, wt.% Mushroom growth, points CFU complex according to example 1 polyvinyl butyral mushrooms bacteria 2 39 61 0 0 0 fourteen 25 75 0 0 0 fifteen 10 90 one 4 × 10 ³ 7 × 10 ⁴ 16 thirty 70 0 0 0 17 fifty fifty - - -

From the data of this table it can be seen that the coating according to example 15 does not completely suppress the growth of microorganisms, although it does not cause corrosion damage to the surface. Solutions of the mixture of the complex and polyvinyl butyral containing more than 40 wt.% Of the complex (Example 17) exfoliate, and therefore a uniform coating cannot be formed from them. The surface of the samples in examples 2, 14-16 at the end of the tests are smooth.

Examples 18-21. Coatings on Amg6 aluminum alloy wafers were formed from a mixture of solutions in isopropyl alcohol, as described in Example 2, a complex synthesized as described in Example 1, and polyvinyl butyral, differing in the content of acetal and vinyl alcohol units (Table 3). The content of the complex in the coatings is 30 wt.%.

Table 3 Chemical structure of various grades of polyvinyl butyral Example No. Polyvinyl Butyral Brand The concentration of units, mole unit% acetal acetate vinyl alcohol eighteen "Mowital B60T" 69-72 2 24-27 19 "Mowital B60HH" 81-84 2 12-16 twenty "Mowital B30H" 75-78 3 18-21 21 Mowital B30T 68-72 3 24-27

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection. The surface of the samples at the end of the test is smooth.

Example 22. The synthesis of a styrene-maleic anhydride copolymer and its modification with sodium hydroxide was carried out as described in Example 1. From this modified copolymer, a complex with dimethyldecylbenzylammonium chloride was obtained. To this end, 21.37 ml of a 5.0% aqueous solution of dimethyldecylbenzylammonium chloride was added dropwise to 15.0 ml of a 4.1% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. sodium carboxylate groups per 1 mol of dimethyldecylbenzylammonium chloride. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (concentration - 4.9 g / dl).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Example 23. The synthesis of a copolymer of styrene with maleic anhydride and its modification with sodium hydroxide was carried out as described in example 1. From this modified copolymer, a complex with dimethyl tetradecylbenzylammonium chloride was obtained. To this end, 25.26 ml of a 5.0% aqueous solution of dimethyltetradecylbenzylammonium chloride was added dropwise to 15.0 ml of a 4.1% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. groups of sodium carboxylate per 1 mol of dimethyltetradecylbenzylammonium chloride. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (5.1 g / dl concentration).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Example 24. The synthesis of a copolymer of styrene with maleic anhydride was carried out as described in example 1. To obtain a modified copolymer in which 60% of the groups of maleic anhydride are converted to carboxylate groups, the modification was carried out with an aqueous solution of potassium hydroxide. For this, 2.5 g (13.08 mmol-unit of maleic anhydride) copolymer and 0.61 g (15.72 mmol) of potassium hydroxide dissolved in 50 ml of water were charged into a flat-bottomed flask equipped with a reflux condenser and a magnetic stirrer. The process was conducted in a boiling water bath for 5 hours. At the end of the process, the entire copolymer passed into the solution, the pH of this solution of the modified copolymer was 8. From the solution, the copolymer was precipitated with 1,4-dioxane, separated from the solution on the filter and dried in vacuum at room temperature. A complex with catamine AB was obtained from this modified copolymer. For this, 10.58 ml of a 14.58% aqueous solution of catamine AB was added dropwise to 15.0 ml of a 5.71% aqueous solution of the modified copolymer. The reagents were mixed at the rate of 1 g · equiv. potassium carboxylate groups per 1 mol of catamine AB. A white precipitate of the complex stood out, which was washed with water and dried to constant weight in a vacuum oven at 40 ° C.

Coatings from this complex on Amg6 aluminum alloy plates were formed from a solution in isopropyl alcohol (concentration - 5.2 g / dl).

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Examples 25-28. Coatings on plates of aluminum alloys D16AT, AK6, D16T and AD1 were formed from a solution in isopropyl alcohol (concentration - 4.84 g / dl) of the complex synthesized as described in example 1.

On thus formed coatings, fungal growth according to GOST 9.050-75 is absent and CFU of bacteria and fungi was not detected at 3-fold infection.

The surface of the samples at the end of the test is smooth.

Thus, complete prolonged protection of aluminum alloy products from microorganisms, excluding corrosion changes in the surface of these products, is achieved by forming coatings from a complex of dimethylalkylbenzylammonium chloride containing an alkyl group from C ₁₀ to C ₁₄ or their mixtures from C ₈ to C ₁₆ , s copolymer of styrene with maleic anhydride, previously subjected to chemical modification with the disclosure of anhydride cycles when treated with alkali solutions, the amount of alkali in which varies from 50 to 60% with respect to the amount necessary to neutralize all the carboxyl groups formed (examples Nos. 1, 3, 4, 13, 22-28), and a mixture of this complex with polyvinyl butyral containing 25-50 wt.% Complex (examples Nos. 2, 5, 14, 16, 18-21). The use of complexes with individual dimethylalkylbenzylammonium chlorides in which the alkyl group is shorter than C ₁₀ (examples Nos. 8 and 9) and longer than C ₁₄ (examples Nos. 6 and 7) leads to a decrease in the antimicrobial properties of the coating and incomplete suppression of the growth of microorganisms. The use of copolymer complexes in which more than 60% of the carboxyl groups formed during the opening of the anhydride cycles of maleic anhydride units turns into carboxylate ones leads to corrosion damage to the surface of the material with the formation of pitting (examples nos. 10 and 11). The use of complexes of copolymers in which less than half of the carboxyl groups formed during the opening of the anhydride cycles of maleic anhydride units turns into carboxylate does not lead to a complete prolonged inhibition of microflora growth (example No. 12). The use of mixtures of these complexes with polyvinyl butyral containing less than 25 wt.% Of the complex does not provide complete prolonged inhibition of microflora growth (example No. 15). The formation of homogeneous coatings from mixtures containing more than 40 wt.% Of the complex is not possible, since solutions of these mixtures of this composition exfoliate (Example No. 17).

The proposed method for the manufacture of a polymer complex with antiseptic properties and an antiseptic coating based on it can be used for surface modification of materials from aluminum alloys when they are:

- long-term operation in space objects;

- in submarines;

- in ground or underground enclosed spaces;

- in workshops of clean assembly;

- in rooms to which certain requirements are imposed on the microbial load of their surface - class 100, 10000 and 100000.

Claims (1)

A method of manufacturing an antiseptic coating for products from an aluminum alloy that does not cause corrosion, characterized in that the coating is formed from a complex of dimethylalkylbenzylammonium chloride containing an alkyl group from C ₁₀ to C ₁₄ or a mixture of alkyl groups from C ₈ to C ₁₆ with a styrene-maleic copolymer anhydride previously chemically modified to open anhydride rings to form carboxyl groups, 50 to 60% of which are neutralized to form carboxylate groups, or a mixture of this complex and a polyvinyl butyral with their proportions, in weight.%:
antiseptic polymer complex 25-40 polyvinyl butyral 60-75