RU2478114C1 - Multilayer composite antifoulding coating providing repellent-chemobiocidal protection - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: multilayer composite coating contains a first bottom primer coat with anticorrosion properties which is based on an epoxy resin with target additives. The coating has a second coat composed of 1-2 layers of antifoulding enamel with an insoluble matrix based on a vinyl polymer which is modified by epoxy resin and contains copper (I) oxide as a biocide. The dried (hardened) second coat is covered with a third top coat consisting of at least one layer of sparingly soluble or rapidly dissolving self-polishing paint based on colophony, combined with polytetrafluoroethylene which contains a biocide in form of copper compounds. The third (top) coat is deposited in a continuous layer or in fragments (in form of a mesh).

EFFECT: coating provides efficient antifouling protection.

1 cl, 1 tbl, 12 ex

Description

The invention relates to protection against fouling of ships and hydraulic structures and can be used in the shipbuilding industry and hydraulic engineering.

The fouling, in particular, of the technological equipment of a flowing hydroelectric station with aquatic organisms leads to significant economic damage. The most serious consequences arise when settling on the surface of the equipment, structure and structures of the bivalve mollusk Dreissena (Dreissena polymorpha (Pall.)), Which subsequently spread throughout Europe for decades (up to 57-58 N) and penetrated into North America.

The overgrowth of facilities and technological equipment by zebra mussel also creates various difficulties in the operation of the equipment (the so-called biological interference or bio-interference, impairs the ability to control their condition. there is a need for expensive equipment repairs, as well as periodic shutdowns for cleaning surfaces.

The only effective way to combat biofouling of the flow part of a hydroelectric power station is their chemical (chemobiocidal) protection by applying anti-fouling paint and varnish coatings (LCP) to the surfaces in contact with the aqueous medium. The effect of their action is to create in the laminar (parietal) coating layer such a concentration of biocide that would be sufficient to destroy the larvae of fouling organisms that enter it.

Modern anti-fouling paints should be environmentally friendly, i.e. do not contain poisons. Of all the known biocides, the most accessible in this regard is copper (I) oxide. Typically, antifouling paint contains synthetic film-forming (PSX-LS, A-15, polyisobutylene, etc.), rosin, copper oxide (I), plasticizer, organic solvents [Gurevich ES, Rukhadze EG, Frost A.E. . and others. Protection against fouling. - M .: Nauka, 1989, p.271]. However, anti-fouling paints do not have a sufficiently high biological activity and do not provide long-term protection against fouling and corrosion in the underwater coating system, in addition, copper (I) oxide is an expensive drug.

From this monograph Gurevich ES and others “Protection of fouling” known means of protection against fouling - paint antifouling coatings containing various poisons, most often copper oxide. However, the effective period of such coatings does not exceed 1.5-2 years. One reason for the limited protection period is the uneven rate of leaching of poison from the coating. As a result of numerous studies, the initial leaching rate of copper oxide is 100-500 μg / cm ² - day. (1-1.5 g / m ² - day), and after 12-18 months, the exposure in sea water is reduced to 10-15 μg / cm ² - day.

The calculation shows that in this case, the main amount of poison is leached during the initial period of operation of the coating and after 15-18 months. 10-15% of copper oxide of the initial amount remains in the coating film. The same applies to antifouling paints containing other monomeric poisons, for example tributyltin oxide, tributyltin fluoride, arsenic compounds. For effective protection against fouling, it is necessary to reduce the rate of leaching of poison in the initial period of operation of the coating and thereby significantly increase the effective period of the coating.

In order to increase the effective period of antifouling paint, as well as to reduce friction when the vessel is moving, a thin hydrophilic or partially soluble layer in sea and fresh water is applied to the paint surface. Such a layer, preventing the leaching of poison from the underlying layer, regulates the rate of leaching of the poison and reduces the initial rate of its leaching.

In particular, from SU 579294, 11.25.1977, a multilayer anti-fouling coating of the underwater part of ships is known, consisting of a layer of antifouling paint and a surface layer based on polyorganomethacrylate containing organotin radicals. In this case, as an antifouling paint, for example, paint ХВ-5153 or ХВ-750 based on perchlorovinyl resin containing copper oxide, a mixture of rhodanized copper and an arsenic-organic compound is used as a biocide.

This coating reduces the initial leaching rate of the poison, but does not provide an increased modern level of protection against fouling.

From SU 273905, 04/15/1983 antifouling paint is known containing (in parts by mass):

rosin 12-25, salicylic acid 3-10, salicylic acid anilide 2-5, zinc white 2-10, copper oxide 25-40, dibutyl phthalate 3-8, solvent naphtha 12-18.

However, the service life of such paint does not exceed 1.5 years, and in addition, it is characterized by a long drying time of the coating in air, insufficient weather resistance and resistance of the coating to fouling with a bacterial-mucous film.

To increase the life of the antifouling coating to 4-5 years, as well as to prevent the rapid consumption of copper poisons in fresh water, during the completion of ships afloat, antifouling paint with a completely soluble film-forming base is applied over a paint layer on a partially soluble film-forming base, for example, grade XB -53, XC-79, KR-24 (1-2 layers).

In this invention, rosin derivatives are used to facilitate the release of the biocide to the coating surface. This substance (rosin salicylic ester) dissolves on contact with water. The gradual dissolution of rosin particles creates microspores in the coating and facilitates the diffusion of the biocide to the surface (in this paint it is copper oxide). Therefore, the main idea of this invention is to increase the release rate of the biocide. Additional evidence of this is an indication that this paint can be used to protect ships during fouling when building them afloat. During this period, many brands of anti-fouling paints are not effective enough, since the rate of leaching of biocide from them depends on the speed of the water flow (vessel motion).

However, as a result of the dissolution of one of its main components, the paint acquires a loose consistency and loses the necessary mechanical strength and resistance to a number of harmful environmental factors. As indicated in SU 273905, its authors themselves note these phenomena as:

- extremely short service life (no more than 1.5 years);

- insufficient weather resistance (i.e., rapid destruction during temporary drainage, which is inevitable during shutdowns and repairs of equipment operating in the aquatic environment);

- insufficient resistance to fouling with a bacterial-mucous film (i.e., the paint is destroyed as a result of the waste products of bacteria settled on its surface).

Obviously, such a coating in itself is unsuitable for use in the long-term operation of watercraft or other types of underwater equipment. Its purpose is a very effective, but short-term protection against fouling (for example, during the completion of ships afloat).

However, in order to some extent compensate for the above disadvantages (for this purpose, and not some other), it is recommended to apply it to other types of anti-fouling paints (XB-53, etc.). The role of the latter is to prevent the fouling of areas in which the destruction of paint based on rosin salicylate occurred. For example, after the completion of the ships, it is these paints (XB-53 and others) that will perform protective functions.

Similar coating systems are also described in SU 1090696, 05/07/1984. containing layers of anti-fouling paint based on a partially soluble matrix, for example, ХВ-5153, ХВ-5243, ХС-79, on top of which layers of a biocide-permeable coating based on polyvinyl acetate in combination with rosin containing a water-soluble filler (boric acid, sodium fluoride, copper sulfate), pigments, solvents. However, this known coating system does not provide effective protection against fouling.

In recent years, anti-fouling coatings with self-polishing properties have found application. Such coatings gradually dissolve, as a result of which the fresh paint surface is continuously exposed, and moving sea water smooths the coating surface. British Patent 1124297 describes a film-forming copolymer containing triorgananol as a comonomer, giving self-polishing antifouling coatings.

Known self-polishing anti-fouling paints use a binder, which is a linear polymer with side groups that are removed from the polymer by reaction with sea water, and the residual polymer is sufficiently dispersible or soluble to remove paint from the surface to release a fresh binder layer capable of a similar reaction with sea water.

Coatings from such self-polishing paints retain their original smoothness and can even become even smoother due to the relative movement of water. The gradual thinning of the paint film regulates the release of a biocide that is active against fouling and is present in the paint as a pigment and / or released as removable groups. Thus, the biocide contained in the paint tends to release from the surface at an approximately constant rate.

Many self-polishing paints use a binder containing triorganotin esters as cleavable groups. The triorgananol tin esters are easily hydrolyzed, which determines the self-polishing properties, and the released triorganotin provides a biocidal effect. Examples of such paints are described in British patents 1124297 and 1457590, as well as in European applications 51930, 151809 and 218573. Japanese applications 321061/61 and 231062/61. UK application 2159827 describes similar paints with removable diorgano groups. However, water quality requirements require the replacement of tin compounds in marine paints.

Thus, today according to the mechanism of action, antifouling coatings (paints and enamels) are divided into 2 fundamentally different types:

- coatings with an insoluble matrix (contact or, more precisely, diffusion coatings). The intake of biocide on the surface of the paintwork is due to the constant leaching (diffusion) of the biocide from the paint. The thickness of the leached layer is progressively increasing. To reach the surface in the laminar layer, the biocide must pass through the diffusion process the entire leached layer. Therefore, as such a coating is used, the rate of leaching of the biocide decreases, and according to the exponential law;

- coatings with a soluble base (self-polishing coatings) in which the dissolution of the matrix and biocide occurs simultaneously. In the case of equal rates of their dissolution, the duration of the effect of exposure to fouling (unlike diffusion coatings) is constant. However, the rate of release (dissolution) of self-polishing coatings depends on the flow rate of water washing the surface to be protected. Therefore, in conditions of a constant flow of water moving at high speed (namely, such conditions exist in most of the equipment of the flowing part of a hydroelectric power station), the duration of these paints decreases.

Contact LPK were put into practice much earlier. Self-polishing coatings were developed only in the second half of the 20th century and for a long time were used exclusively for painting the underwater part of high-speed vessels. Therefore, to protect the flow part of the hydroelectric power station, only contact-type hydroelectric power stations are currently used.

There are two ways to increase the efficiency (profitability) of a chemical:

1. Increase the duration of anti-fouling coatings (frequency of costly shutdowns of hydraulic units).

2. To reduce the consumption of anti-fouling coatings while maintaining their validity.

In accordance with this, a method has been developed that is based on the use of the positive properties of both types of wood-based complex in their combined use.

The technical task of the claimed invention is to increase the duration of the effective action of anti-fouling paint and varnish material and the ability to select the best option for a protective coating based on local conditions and operating conditions for a particular type of equipment.

The stated technical problem is achieved by a multilayer combined anti-fouling coating, which also provides repellent-chemobiocidal protection of products and structures, which is a coating system of successively applied coating layers and containing a lower first coating directly adjacent to the surface to be protected, made of a primer with epoxy-based anti-corrosive properties, second coating made of 1-2 layers of anti fouling enamel with an insoluble matrix based on a vinyl polymer modified with an epoxy resin and containing copper oxide as a biocide, and a third outer coating applied to a second cured coating made of one layer of sparingly soluble or quick-soluble in water anti-fouling self-polishing rosin-based paint in combination with polytetrafluoroethylene containing copper compounds as a biocide and applied either as a continuous coating or in the form of a lattice.

Thus, the essence of the claimed invention lies in the layer-by-layer application of anti-fouling (anti-fouling) coatings of two types.

In the simplest version: the bottom layer is contact paintwork; the top layer is a self-polishing paintwork. The coating is applied in the spring. In the warm season, when the intensity of sedimentation of the larvae of the fouling is the highest, self-polishing LCP is triggered, in the next long period, the surface is protected by an exposed layer of contact LCP. A complicated version of the coating is possible - applying two layers of different self-polishing paintwork with different toxicological characteristics.

The biocides contained in anti-fouling LCPs have not only toxic effects on the larvae of fouling organisms, but also repellent (repellent). Thus, the protection of the surface in contact with water can be achieved not only with continuous coating, but also with partial coating (for example, in the form of a grating). The percentage of the surface to be coated with LCP is determined by the repellent properties of this brand of LCP and the composition of mass species of fouling organisms.

The advantage of the proposed technology is its great environmental safety. The amount of biocides entering the environment is reduced in proportion to the decrease in paint consumption.

As the first coating of the (lower) layer directly adjacent to the surface to be protected, primers with anticorrosive properties based on epoxy resin are used, for example, EP-0199 rust primer (TU 6-10-2084-86), EP-057 primer and others .

In addition to the epoxy resin, epoxy primers also contain a hardener (for example, amide type or polyamide type, etc.), as well as fillers and other targeted additives.

As the second coating applied to the epoxy primer in the coating, anti-fouling enamels with an insoluble matrix based on a vinyl polymer (perchlorovinyl resin, a vinyl chloride copolymer modified with an epoxy resin, for example, enamels of the type ХВ-5286 (GAMMA-ХВ-5286С, anti-fouling) are used XC-5226 (anti-fouling), etc. Some data on their properties are given in table 1.

As a third (top) coating, the system contains a coating based on self-polishing rosin-based anti-fouling paints in combination with polytetrafluoroethylene containing a copper compound as a biocide (see Table 1).

The recommended technology for applying anti-fouling coatings with both a soluble and an insoluble base in most cases involves the sequential application of 2-3 layers. In the developed multilayer combined anti-fouling coating, the optimal number of layers can be:

- 1 coating layer with an insoluble base;

- 1 coating layer with a soluble base, the optimal number of layers can be:

1-2 coating layers with an insoluble base;

- 1 coating layer with a soluble base.

Thus, the proposed technology for obtaining a “multilayer combined anti-fouling coating” does not imply a fundamental increase in the cost of measures to protect against biofouling. In some cases, it can be even lower than using traditional technologies.

Depending on the specific conditions (operating mode of protected types of underwater equipment; biology features of mass species of fouling organisms), the number of coating layers with a soluble base can be increased. Moreover, this may be an increase in the layers of not only one brand of anti-fouling coating, but also the sequential application of layers of two different coatings.

The following are examples of anti-fouling enamels and paints with insoluble and soluble (sparingly soluble and instant) matrices, as well as an example of a primer anticorrosive epoxy composition.

In the experiments conducted at the Rybinsk and Uglich HPPs, for the preparation of various combinations of multilayer combined coatings, for example, the following paints were used:

1) anti-fouling coatings with an insoluble base:

- anti-fouling enamel XC 5226. Regulatory document - TU 2313-022-98605321-2007;

2) anti-fouling coatings with a soluble base:

- Trilux 33. Instructions and Certification Document - Safety Data Sheet International Paint YBA591;

- Nautical. Guidance document - Safety Data Sheet International Paint YBA883;

3) Primer EP 0199. Regulatory document-0199 TU 6-10-2084-86.

The tests were carried out on steel plates (size - A4 sheet format), fixed with cables in a stream of water passing through the flow part of the hydroelectric power station. Structures, constructions, and technological equipment, which is part of the flow part of the hydroelectric power station, in the warm season are intensively overgrown with bivalve mussel-zebra mussel (Dreissena polymorpha (Pall.)). Coatings were applied with a brush and dried in accordance with the instructions given in regulatory and instructional certification documents.

The following anti-fouling coatings used in the multilayer combination coating of the invention were tested:

Option 1

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 1 layer with a thickness of 50-60 microns;

3) moderately soluble anti-fouling paint Trilux 33 - 1 layer of a continuous coating with a thickness of 50-60 microns.

Option 2

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 1 layer of 50-60 microns;

3) moderately soluble anti-fouling paint Trilux 33 - 1 layer of a continuous coating with a thickness of 50-60 microns.

Option 3

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 2 layers of 50-60 microns each;

3) moderately soluble anti-fouling paint Trilux 33 - 1 layer of fragmented coating in the form of a lattice (50% of the total area), 50-60 microns thick.

Option 4

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 2 layers of 50-60 microns each;

3) Nautical instant anti-fouling paint - 1 layer of continuous coating with a thickness of 50-60 microns.

Option 5

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 1 layer of 50-60 microns;

3) Nautical instant anti-fouling paint - 1 layer of continuous coating with a thickness of 50-60 microns.

Option 6

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 2 layers of 50-60 microns each;

3) moderately soluble anti-fouling paint Nautical - 1 layer of fragmented coating in the form of a lattice (50% of the total area), 50-60 microns thick.

Option 7

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel GAMMA-XB-5286 C - 1 layer of 100-120 microns;

3) moderately soluble anti-fouling paint Trilux 33 - 1 layer of a continuous coating with a thickness of 50-60 microns.

Option 8

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel GAMMA-XB-5286 C - 1 layer of 100-120 microns;

3) moderately soluble anti-fouling paint Trilux 33 - 1 layer of segmented coating in the form of a lattice (50% of the total area), 50-60 microns thick.

Option 9

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel GAMMA-XB-5286 C - 1 layer of 100-120 microns;

3) Nautical instant anti-fouling paint - 1 layer of continuous coating with a thickness of 50-60 microns.

Option 10

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel GAMMA-XB-5286 C - 1 layer of 100-120 microns;

3) Nautical instant anti-fouling paint - 1 layer of fragmented coating in the form of a lattice (50% of the total area), 50-60 microns thick.

Option 11 (control experiment a)

primer EP 0199 - 2 layers 60-80 microns thick each.

Option 12 (control experiment b)

1) primer EP 0199 - 2 layers with a thickness of 60-80 microns each;

2) anti-fouling enamel XC 5226 - 1 layer of 50-60 microns.

All variants of the painted plates were made in triplicate. Thus, 72 experimental plates were exhibited at two hydropower plants.

Preparation of plates and application of paints and varnishes was carried out in accordance with GOST 8832-76. The drying process of each of the successively applied layers was controlled in accordance with GOS 19007-73.

Before the exposure of the plates in the laboratory, a series of tests were carried out characterizing the mechanical strength upon impact (GOST 4765-73), bending (GOST 6806-73) and adhesion (GOST 15140-78). The test results indicate that all plates prepared for the exposure, with the exception of option 12 (control experiment b), met the requirements of GOST.

Experiment Results

At the end of the exposure, in accordance with GOST 9.407-84, a visual examination of the appearance of the plates was carried out in order to identify defects. Peeling, cracking, peeling or swelling of the film was not noted in any of the options. On some plates, traces (scratches) from a collision with floating objects (marshmallow, etc.) are visible. But fragmentary destruction of the antifouling coating was noted only in option 12 (control experiment b). On wafers with a continuous or fragmented outer layer consisting of a rapidly dissolving anti-fouling coating of the Nautical brand (options 4-6; 9-10), its thinning is noted.

None of the options for multilayer combined anti-fouling coatings (1-10) showed the formation of biofouling. On the plate, covered only with primer EP 0199 (Option 11 “control experiment a”), a settled number of zebra mussel was found in large quantities.

Below is an additional justification for achieving the claimed coating (coating system) anti-fouling effect, which also provides repellent chemobiocidal protection of products and structures.

The term "chemobiocidal anti-fouling" is synonymous with the term "chemical anti-fouling". These concepts mean the use of toxic substances to combat fouling. The most common (but not the only) type of chemobiocidal or chemical protection is the use of anti-fouling paints and enamels).

The term “repellent protection” is already used in the specialized literature, but it means the use of special repellents that are not part of anti-fouling paints. (Railkin A.I. Colonization of solids by benthic and organisms.) St. Petersburg: Publishing House St. Petersburg. Univ., 2008.427 s.

Biological interaction (biological effect of the combined effects of the coating layers according to the invention).

In the practical application of a multilayer combined anti-fouling coating, the biological interaction of the layers consists in a sequential (in time) toxic effect on the attached larvae of fouling organisms of biocides contained in successively eroded (dissolved) layers of various paints. In this case, the temporary nature of the toxic effect is uneven, corresponding to the dynamics of biofouling processes. First, the development of biofouling is prevented by the erosion of the layer (s) of paint with a soluble matrix, in the subsequent (final) period, the toxic effect on the settling fouling occurs due to the diffusion of the biocide from the layer of anti-fouling paint with an insoluble matrix.

The advantages of using consecutively applied layers of paints with soluble and insoluble bases (matrices) are as follows:

1. The use for protection of hydraulic structures (GTS) only soluble matrix inks, which are generally more environmentally friendly and effective, cannot provide the necessary protection against biofouling. This is due to the fact that the rate of dissolution (flushing) of paints with a soluble base largely depends on the speed of the water flow. This factor, in fact, determines their validity. And since the flow rate at different parts of the protected surface of the GTS is significantly different, the erosion of the paint occurs unevenly. As a result, the disappearance of the antifouling coating (and the development of biofouling on them) will be observed in certain areas at a certain time. This will require re-painting at a time when a significant part of the anti-fouling coating has not yet developed its resource. Thus, unreasonable costs will be required (taking into account the cost of paints and the area of structures of hydraulic structures - very significant). It is the uneven erosion that is the main obstacle to the use of new effective anti-fouling paints for the protection of underwater equipment (their use is limited to small vessels). This disadvantage can be overcome if a layer of anti-fouling paint with an insoluble matrix is applied under the exposed dissolving coatings that are exposed.

2. The validity period of the “multilayer combined coating” is significantly longer than that of anti-fouling coatings with insoluble matrix used to protect hydraulic structures. The periods between necessary preventive stops can be increased by 1.5-2 times.

3. As a rule, anti-fouling paints (both with a soluble and insoluble base) used to protect the underwater surfaces of equipment are applied in two or more layers. This is done in order to increase their resistance to mechanical damage. When using the proposed method, the number of layers of each type of anti-fouling coatings can be reduced in comparison with the requirements of existing painting technologies.

4. In accordance with the nature of the seasonal dynamics of subsidence of mass species of fouling organisms, moderately and rapidly dissolving paints, as well as coatings with an insoluble base, are selected, the combination of which gives an optimal result. This is due to two factors. Firstly, almost all fouling deposits settle only at certain times of the year. Secondly, their resistance to various poisons can be significantly different. Biocides that act effectively on some organisms may not have the desired effect on others

1.1.2. When using the multilayer coating according to the invention, the “repellent-chemobiocidal effect” consists in the biological interaction of the layers when the repellent (repelling) effect and the toxic (chemobiocidal) effect on the settling larvae of fouling organisms are combined. It is known that biocides released from anti-fouling coatings are capable of exerting not only toxic but repellent effects on fouling larvae. To this end, a continuous layer of the underlying paint with an insoluble base is fragmented (for example, in the form of a grating) under the top layer of paint with a soluble base. The percentage of the surface to be coated is determined by the repellent properties of this brand of paint and the composition of mass species of fouling organisms.

The advantages of the proposed technology is its great environmental safety and profitability. The amount of biocides entering the environment decreases in proportion to the reduction in paint consumption.

1.2. Physical interaction is:

- in strong adhesion (attachment) of the outer coating layer to the inner one. This is due to one of the main requirements that are observed when compiling anti-fouling coatings — the ability of their film-forming base to have strong adhesion to other types of paints and varnishes, especially anti-corrosion;

- the outer coating layer (with a soluble matrix) for a certain period of time isolate the inner layers from contact with the aqueous medium. As a result, the biocide contained in the inner layer is preserved for the period necessary for erosion of the upper coating layer. The diffusion of the biocide from the inner coating layer to the outer one is hindered by the physicochemical properties of the soluble inks with the matrix. In other words, the anti-fouling potential of the inner coating layer remains virtually unchanged, but the timing of its effective action (beginning and end) is shifted. As a result, the total length of the period during which the antifouling properties of the multilayer coating are preserved is significantly longer.

1.3. Chemical interaction:

As already indicated in paragraph 1.1, the level of migration of the biocide from one layer to another is negligible. The interpenetration of other components of anti-fouling coatings (film-forming bases, pigments, etc.) is also practically excluded. In addition, the components contained in the coatings, as a rule, either do not enter into chemical reactions between themselves or their speed is negligible compared to the term of application of the proposed multilayer coatings.

Therefore, in the case when the paint layers are applied after the previous layer has dried (and subject to the drying period specified in the specification), the chemical interaction of the layers cannot reach a level that can lead to significant changes in their chemical composition. Therefore, in practice, painting of ships is allowed to leave a layer of old paint intact if it is devoid of signs of peeling and mechanical destruction.

When using a multilayer combination coating according to the invention is achieved:

1. Saving anti-fouling LCP by 30% or more.

2. Reducing the negative impact on the environment.

It should be noted that during the development of this type of coating numerous laboratory experiments were carried out, confirming a well-defined

repellent (scaring) effect in the tested soluble matrix paints, for example, Trilux 33 and Nautical. A laboratory culture of daphnia (Daphnia magna Straus) was used as a test object. The preparation for the experiments was carried out in accordance with the guidelines of RD 118-02-90 “Methodological Guide to Water Biotesting” and the International Standard ISO 6341: 1996 “Water Quality. Determination of the suppression of motility of Daphnia magna 'Straus (Cladocera, Crustacea). Acute toxicity test. " The laboratory experiments were as follows: a standard size glass plate — a microscope slide, coated on both sides with a single layer of anti-fouling paint, for 1 day. exhibited in 100 ml of water. Test objects (daphnia) were placed in a gutter-shaped cell 30 cm long. Containing 100 ml of water. When neatly added to one end of the cuvette 10-20 ml of water from the container in which the exposure of the stained plates was carried out, after 5 minutes, 60-100% daphnia was concentrated on its opposite site. With an increase in the amount of water added to the cuvette from the exposure tank, a partial death of test objects was noted in a number of experiments.

The repellent effect of paints was confirmed during field experiments conducted on the Skhodnya River in the vicinity of the Skhodnaya Hydroelectric Power Station (Moscow). Trilux 33 and Nautical were applied to plates in A4 sheet made of stainless steel, on top of Interprotect and EP 0199 primers, in the form of a grating (with a band width of 1.5-2.0 cm). After that, fragmentarily colored plates were exposed in the river for 2.5 months (July - September). Identical plates coated only with a primer were used as a control experiment.

The main fouling organism in this body of water is the bivalve mollusk of Dreissena (Dreissena polymorpha Pall.), Which creates bio-interference during the operation of various hydraulic structures and water supply systems. At the end of the exposure, specimens of this species were found only on control plates. On fragmented stained plates, mollusks were not observed even in areas where anti-fouling was not applied.

It should also be noted that the Trilux 33 and Nautical soluble paints tested to form the top layer of the combined coating can be re-applied without special preparation to the surface of the matrix paint forming the lower layer of the combined coating without full preparation. In each particular case, it is possible to develop a service regime for a multilayer coating, which allows only a top coat to be applied when re-staining. Thus, for a very long period, not only the lower part of the multilayer anti-fouling coating is preserved, but also the anticorrosive coating located under it. In this case, soluble paint in the combined coating can be applied in 1-2 layers, and not in 3 or more (as recommended for its separate use). Together, all this will give significant cost savings (the consumption of anti-fouling and anti-corrosion materials can be reduced several times).

The attached table 1 presents some characteristics of the used examples of paints and enamels, soil when forming a multilayer combined anti-fouling coating according to the invention.

Table 1 Specifications Data Primer for rust EP-0199 TU 6-10-2084-86 Application Method brush Drying 24 hours at 20 ° C (GOST 19007-73) Number of layers one Single layer thickness 60 microns Components Epoxies, polyamines, shale oil and special components Enamel HS-5226 ANTIFOULING TU 2313-022-98605321-2007 Application Method brush Drying 3 hours at a temperature of 20 ° C Number of layers one Single layer thickness 60 microns Components 1. The active component is copper oxide; 2 - Base: epoxy modified vinyl polymer ENAMEL "GAMMA-XB-5286 S" ANTIFOURING TU 2313-021-98605321-2007 Application Method brush Drying 8 hours at a temperature of 20 ° C Number of layers one Single layer thickness 120 microns Components 1. The active component is copper oxide (CAS 1317-39-1); 2 - Base: epoxy modified vinyl polymer. TRILUX BLACK SAFETY DATA SHEET YBA591 Application Method brush Drying 2 hours at a temperature of 20 ° C Number of layers One Single layer thickness 60 microns Components The active component is copper oxide (CAS 1317-39-1); 1,2,4-Trimethylbenzene; 1,3,5-trimethylbenzene; dichlorofluanide; rosin; xylene; copper (I) thiocyanate; solvent naphtha (from oil), light, aromatic; zinc oxide; Polytetrafluoroethylene (Teflon) NAUTICAL BLUE ANTIFOULING SAFETY REFERENCE SHEET YBA883 Application Method brush Drying 2 hours at a temperature of 20 ° C Number of layers One Single layer thickness 60 microns Components The active component is copper oxide (CAS 1317-39-1); zinc-ethylene-2-dithiocarbomad (CAS. 12122-67-7); 1,2,4-Trimethylbenzene; 1,3,5-trimethylbenzene; copper (I) oxide; ethylbenzene; rosin; solvent naphtha (from oil), light, aromatic; triphenyl phosphate; xylene; zinc oxide; cineb; Polytetrafluoroethylene (Teflon)

Claims (1)

A multilayer combined antifouling coating, which also provides repellent-chemobiocidal protection of products and structures, which is a coating system of layers of coatings successively applied to the surface of products and structures and containing a first lower coating directly adjacent to the surface to be protected, made of a primer composition with anticorrosive properties based on epoxy resin, a second coating made of 1-2 layers of anti-fouling enamel with an insoluble matrix based on a vinyl polymer modified with an epoxy resin containing copper oxide as a biocide and a third topcoat applied to a second cured coating made of at least one layer of sparingly soluble or rapidly soluble in water anti-fouling self-polishing rosin-based paint in combination with polytetrafluoroethylene containing copper compounds as a biocide and applied either as a continuous coating or as a lattice.