RU2427601C1 - Protective coating - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: protective coating has a base consisting of two layers of intertwined rows of threads attached by radiotransparent material, with a film of hydrogenated carbon ingrained with particles of ferromagnetic material is deposited on each layer through vacuum sputtering. On the surface of the film which is deposited on the outer layer of the intertwined rows of threads, there is a lacquer coating obtained from a suspension which contains a fluorinated polymer, zinc sulphide with a hexagonal crystal structure, selenium, sulphur, a catalyst, a wetting agent and a curing agent.

EFFECT: high efficiency of radio absorption and concealment in optical-location infrared band and on laser points of the optical band.

9 cl, 1 dwg, 2 tbl, 14 ex

Description

The invention relates to radio engineering, and more particularly to multifunctional coatings providing radio absorption and secrecy in the optical radar, infrared and laser points of the optical range. The invention may find application to increase stealth and reduce the likelihood of detection of objects and equipment of marine, land, aviation and space technology.

A protective coating is known (see patent RU No. 2215764, IPC C09D 123/34, publ. 10.11.2003) based on a composition comprising a polymer binder and a filler. As a polymer binder, it contains (19-21)% solution of chlorosulfonated polyethylene in a hydrocarbon solvent, and as a filler a mixture of soot and graphite in the following ratio of components, wt.%:

(19-21)% solution of chlorosulfonated polyethylene in hydrocarbon solvent 63.0-69.2 soot 10.0-12.0 graphite 20.8-25.0

Known coating shields electromagnetic radiation in the radar, optical and laser wavelength ranges. However, the known protective coating does not provide acceptable values of radio absorption, and also does not provide stealth for objects in the visible region (black color) and IR spectral regions, since it contains all known components of black paint materials (a mixture of soot and graphite); and, thus, has a high emissivity (ε) in the infrared region of the spectrum (ε ~ 0.94-0.96).

Known paint coating absorbing electromagnetic waves (see application CN No. 101255292, IPC C09D 5/32, publ. 10.11.2001) containing a homogeneous mixture of a polymer, carbon micropowder, carbon fibers and micropowder from TiO ₂ .

The known coating does not provide acceptable values of radio absorption, and also does not provide stealth for objects in the visible region (black color) and IR spectral regions, since it contains all known components of black paint materials (a mixture of a polymer of carbon micropowder and carbon fibers) and, therefore, Thus, it has a high emissivity in the infrared region of the spectrum (ε ~ 0.94-0.96).

At present, radar absorbing materials are being intensively developed, which absorb incident electromagnetic radiation with finely dispersed conductive particles included in their composition.

Known protective material (see patent RU No. 2167840, IPC C04B 35/00, publ. 05/27/2001), consisting of a mixture of 0.30-0.45 or 0.55-0.75 mole fractions of strontium titanate and 0.70 -0.55 or 0.45-0.25 molar fractions, respectively, of compounds with the general formula BiMO ₃ , where M is selected from the group of elements including chromium, manganese, iron.

The disadvantage of the known material should be attributed to its significant thickness, necessary for the effective absorption of radio waves. In addition, the coating does not provide stealth in the optical and laser wavelength ranges.

Known protective material (see patent RU No. 2107705, IPC C09D 5/32, publ. 03/27/1998), containing as a polymer binder synthetic adhesive "Elaton" based on latex, and as a magnetic filler - powdered ferrite or carbonyl iron at the following ratio of components, wt.%: synthetic adhesive "Elaton" based on latex 80-20; powdered ferrite or carbonyl iron 20-80.

Known protective material is used for applying on the surface of various geometries products of research, medical and domestic purposes for the absorption of radio emission. However, the known radar absorbing material has insufficient absorption of radio waves and does not provide stealth in the optical and laser wavelength ranges.

Known protective material (see US patent No. 6231794, IPC H01Q 17/00, publ. 05/01/2001), comprising a first layer of porous elastic material, such as polyurethane, coated with a second layer of porous elastic material with conductive particles distributed therein, for example graphite particles powders, or particles of carbon material mixed with metal particles.

A disadvantage of the known protective material is insufficient mechanical strength. The material does not provide stealth in the optical and laser wavelength ranges.

A known absorber of electromagnetic radiation (see TW No. 285528, IPC H01Q 17/00, published 11.08.2007), the basis of which is a cross-linked silicone gel, in which the combustion retardant and the absorber of electromagnetic radiation are introduced in an amount of 200-800 wt. .h. per 100 parts by weight silicone gel.

For the effective absorption of electromagnetic radiation requires a large mass of known absorber, which limits its scope. The material does not provide stealth in the optical and laser wavelength ranges.

Known protective coating (see patent EP No. 1912487, IPC H01Q 17/00, publ. 16.04.2008), comprising a matrix in the form of a thin sheet of organic polymer or inorganic material in which ultrafine carbon particles are dispersed in an amount of 0.01-20 , 0 wt.% Of the total weight of the coating, and also contains a filler selected from the group consisting of metal particles, magnesium carbonate, carbon black, carbon fibers, glass fibers or mixtures thereof.

Known radar absorbing material has heterogeneous properties due to the difficulty of uniformly introducing the ingredients into the base.

A protective coating is known (see patent RU No. 2228565, IPC H01Q 17/00, publ. 05/10/2004), including a base in the form of a woven fabric of at least one layer of interwoven aramid high-modulus filaments coated with a film of hydrogenated carbon on vacuum filaments with ferromagnetic clusters embedded in it in the following ratio of components, wt.%:

Ferromagnetic clusters 50-80 Hydrogenated carbon rest.

A disadvantage of the known protective coating is the fact that the fabric base of each coating layer inevitably leads to anisotropy of the absorbing properties. In addition, the proposed manufacturing technology of the known radar absorbing coating suggests the presence of gaps between the layers, which leads to the manifestation of instability of the properties.

Known protective coating (see patent RU No. 2370866, IPC H01Q 17/00, publ. 20.10.2009), coinciding with the claimed technical solution for the largest number of essential features and taken as a prototype. The prototype coating includes a base of at least two layers of interwoven rows of threads fastened with a radiolucent material, with a hydrogenated carbon film deposited on each layer with particles of ferromagnetic material embedded in it, while the direction of the interwoven rows of threads of one layer of woven material is the direction of the interlaced rows of filaments of an adjacent layer is an angle of 60 ° -120 °, and the content of particles of ferromagnetic material is from 5 wt.% in the film deposited on the outer a layer of interwoven rows of threads, up to 85% by weight in a film deposited on a layer of interwoven rows of threads adjacent to the surface to be protected.

The known coating has an extended frequency range and increased radio absorption efficiency while reducing the thickness and weight of the entire material. However, the coating does not provide secrecy in the optical location, infrared and laser points of the optical range.

The objective of the invention is the creation of a protective coating that provides stealth in the optical radar, infrared and laser points of the optical range while maintaining an extended frequency range and increased radio absorption efficiency.

The task is achieved in that the protective coating includes a base of two or more layers of interwoven rows of threads bonded with a radiolucent material, with a hydrogenated carbon film deposited on each layer with particles of ferromagnetic material embedded in it. The direction of the interwoven rows of threads of one layer makes an angle of 60 ° -120 ° with the direction of the interwoven rows of threads of an adjacent layer. The content of particles of ferromagnetic material ranges from 5 wt.% In the film deposited on the outer layer of the interwoven rows of threads, up to 85 wt.% In the film deposited on the layer of interwoven rows of threads adjacent to the surface to be protected. On the surface of the film deposited on the outer layer of interwoven rows of threads, a paint coating is applied, obtained by applying and drying the composition in the form of a suspension of pigment fillers of zinc sulfide ZnS, selenium Se, sulfur S, in fluorinated polymer solutions. The composition includes a hydroxyl-containing copolymer of fluoroethylene with vinyl ether, hexamethylene diisocyanate, zinc sulfide with a hexagonal crystal structure, selenium, sulfur, tin dibutyl dilaurate (catalyst), a wetting additive in the form of an electrically neutral salt of a polycarboxylic acid with a 50% amino derivative in the form of an amine-derivative compound organic solvent in the following ingredients (wt.%):

hydroxyl-containing fluoroethylene copolymer with vinyl ether 9.5-11.0 hexagonal zinc sulfide crystal structure 47.5-71.9 hexamethylene diisocyanate 3.2-3.6 selenium 0.8-1.1 sulfur 0.3-0.4 tin dibutyl dilaurate 0.1-0.2 wetting agent 0.3-0.4 solvent rest.

Xylene or toluene may be used as a solvent in the composition.

As a fluorinated polymer, the composition includes a hydroxyl-containing copolymer of fluoroethylene with vinyl ether having the following structure:

The pigment part of the paint coating consists of zinc sulfide with a hexagonal crystal structure (wurtzite), specially treated to remove defects in the structure, amorphous selenium and sulfur, and is a filler distributed in a fluorinated polymer.

An electrically neutral salt of polycarboxylic acid with amino derivatives in the form of a 50% solution in high molecular weight aromatic compounds was introduced as a wetting agent (surfactant).

Hexamethylene diisocyanate, which is used for hydroxyl-containing fluorinated polymers, was used as a hardener.

The use of a solvent is necessary to achieve the desired viscosity of the paintwork. In addition, when applied to the underlying layers, the solvent provides increased hydrophobicity and, accordingly, low wettability with water, as well as reduced dirt retention. Since the presence of water on the surface impairs optical performance in the visible and infrared regions, poor wettability (hydrophobicity) is a positive operational factor. In addition, the paint layer based on fluorinated polymers has a reduced combustibility.

The choice of boundaries for the content of components of the paint coating is due to the following circumstances:

When the content of the fluorinated polymer is less than 9.5 wt.%, The protective properties of the coating are not provided, when the content of the fluorinated polymer is more than 11.0 wt.%, The coating performance in the infrared region deteriorates.

When the content of selenium and sulfur outside the formulation, i.e. when the content of selenium is less than 0.8 wt.% and more than 1.1 wt.%; sulfur less than 0.3 wt.% and more than 0.4 wt.%, indicators in the visible region of the spectrum ρ, x, y, z change for the worse.

When the content of the wetting agent is less than 0.3 wt.%, The dispersion efficiency in the polymer-filler system is not ensured; when the content of the wetting agent is more than 0.4 wt.%, its residues impair the optical and protective properties of the coating.

When the catalyst content is less than 0.1 wt.%, The drying time of the coating worsens; when the content of the catalyst is more than 0.2 wt.%, its residues (not entering into the curing reaction) degrade the optical and protective properties of the coating.

When the hardener content is less than 3.2 wt.%, The coating does not dry out, is tacky, and the practical use of the coating is impossible; when the hardener content is more than 3.6 wt.%, its unreacted residues plasticize the coating, reducing its hardness and thereby deteriorating the optical and protective properties of the coating.

The rotation of adjacent layers of interwoven rows of threads relative to each other at an angle from 60 ° to 120 ° allows to reduce the anisotropy of the absorbing properties.

The change in the content of the ferromagnetic absorber in the said film from 5 wt.% In the film deposited on the outer layer of the interwoven rows of threads, up to 85 wt.% In the film, deposited on the layer of interwoven rows of threads adjacent to the surface to be protected, provides smooth coordination of the wave impedances the thickness of the coating, starting from the top layer (consistent with free space), to the last, absorbing layer.

Layers of interwoven threads can be made in the form of a woven fabric.

The filaments of the radar absorbing coating may be made of fiberglass or aramid fibers.

A film of hydrogenated carbon with particles of ferromagnetic material embedded in it can be deposited on one side or on both sides of each layer of interwoven rows of threads.

As a ferromagnetic material, a metal selected from the group of 3d elements can be introduced: cobalt, nickel, iron, samarium and their alloys, as well as barium ferrite doped with rare-earth elements during the deposition process, nickel-zinc and manganese-zinc ferrites with titanium additives .

As a radiolucent material, an adhesive composition based on a rubber or epoxy mixture can be used.

The protective coating is illustrated by drawings, where:

figure 1 shows a cross section of the claimed protective coating;

figure 2 in table 1 shows the compositions of the claimed protective coating;

figure 3 in table 2 gives the technical characteristics of the protective coating;

figure 4 shows the continuation of table 2.

The protective coating 1 (see FIG. 1) contains at least two layers, for example, four layers 2a, 2b, 2c and 2d of interwoven rows of threads 3a and 3b. Layers 2a, 2b, 2c and 2d of rows of interwoven yarns 3a and 3b are made, for example, in the form of a woven fabric. Filaments 3a and 3b may be made of fiberglass or aramid fibers. The direction of the rows of threads 3a and 3b, for example, of one layer 2a, makes the angle φ = 60 ° -120 ° with the direction of the rows of the corresponding threads 3a and 3b of adjacent layer 2b. A film 4 of hydrogenated carbon with particles 5 of ferromagnetic material embedded in it is deposited on each layer 2a, 2b, 2c, and 2d by vacuum spraying. Film 4 can be applied on one side of layers 2a, 2b, 2c and 2d or on both sides. The film 4 contains particles 5 of ferromagnetic material in an amount that varies from 5 wt.% In the upper layer 2a to 85 wt.% In the film deposited on the lowest layer 2b adjacent to the surface to be protected. The remaining mass of film 4 is hydrogenated carbon. The film 4 is usually performed with a thickness of 500-1500 nm. Particles 5 of ferromagnetic material, as a rule, have a size of up to 0.05 microns and close to spherical geometric shape. The layers 2a, 2b, 2c and 2d of the rows of interwoven yarns 3a and 3b are fastened with an adhesive radiolucent material 6. A coating 7 is applied to the outer layer 2a. Coating 7 is applied by pneumatic spraying or using roll machines from a composition in the form of a suspension of ingredients of the following composition (wt. .%):

hydroxyl-containing fluoroethylene copolymer with vinyl ether 9.5-11.0 hexagonal zinc sulfide crystal structure (wurtzite) 47.5-71.9 selenium 0.8-1.1 sulfur 0.3-0.4 tin dibutyl dilaurate 0.1-0.2 wetting agent 0.3-0.4 hexamethylene diisocyanate 3.2-3.6 solvent (xylene, toluene) rest.

The study of the microstructure of the inventive protective coating was carried out using a JSM-35 electron microscope. Particles 5 can be made of any known ferromagnetic material having significant absorption of microwave radiation. As such materials can be used, for example, cobalt, nickel, iron, alloys of these metals, ferrites. Table 1 shows the compositions of the claimed protective coating, and table 2 shows the experimental data on the absorption of microwave radiation by the claimed protective coating and its optical characteristics (ε _3-5 , ε _8-14 , R _1.06 , R _10.6 , ρ , x, y; z).

Microwave absorption was studied in the frequency range 5–80 GHz on waveguide measuring lines for the case of normally incident electromagnetic (EM) radiation. The real and imaginary parts of the dielectric (ε ', ε ”) and magnetic (µ', µ”) permeabilities and EM loss factors at reflection (R) were determined: R = -10 · log (W _R / W) dB, where W, W _B - power of the incident and reflected waves, respectively

The optical characteristics of the claimed coating was determined on a spectrophotometric setup described in the book by Gurevich MM, Itsko EF, Serdenko MM "Optical properties of coatings." - M.: Chemistry, 1984.

For efficient absorption of EM radiation by a granular structure, it is necessary to have large values of ε ”and µ”, and the wave impedance Z = [(µ '+ iµ ”) / (ε' + iε”)] ^1/2 should be close to unity. As it was established by the authors, the claimed protective coating has large values of µ ', µ ”, ε', ε”.

For the manufacture of the inventive protective coating, any known method of vacuum sputtering can be used, for example, laser sputtering, ion sputtering from self-contained ion sources, ion-plasma sputtering, in particular magnetron sputtering of graphite and ferromagnetic targets. Compared to other methods of film deposition, magnetron sputtering has several advantages, the main of which are the high film growth rate, their good adhesion and low pollution by foreign gas inclusions, the low temperature of substrate heating, the possibility of sputtering both conductors and dielectrics and producing ultrathin films with small radiation defects, as well as low inertia of the process.

Further, the outer layer of the vacuum-sprayed coating is additionally sprayed by pneumatic spraying or using roller machines to paint the coating composition in the form of a suspension containing fluorinated polymer, zinc sulfide, selenium, sulfur, a catalyst, a wetting agent and a hardener in a ratio.

Example 1. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 4 wt.% And hydrogenated carbon 96 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 60 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing fluoroethylene copolymer with vinyl ether 8.0 hexagonal zinc sulfide crystal structure 45.0 selenium 0.7 sulfur 0.25 tin dibutyl dilaurate 0.05 wetting agent 0.2 hexamethylene diisocyanate 3.0 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 2. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 5 wt.% And hydrogenated carbon of 95 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 60 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 9.5 hexagonal zinc sulfide crystal structure 47.5 selenium 0.8 sulfur 0.3 tin dibutyl dilaurate 0.1 wetting agent 0.3 hexamethylene diisocyanate 3.2 toluene solvent rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 3. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 5 wt% and 95 wt% hydrogenated carbon. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.%. in the bottom layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 90 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 9.8 hexagonal zinc sulfide crystal structure 55.0 selenium 0.9 sulfur 0.35 tin dibutyl dilaurate 0.15 wetting agent 0.35 hexamethylene diisocyanate 3.4 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 4. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 5 wt.% And hydrogenated carbon of 95 wt. % in the upper layer and with a cobalt content of 85 wt.% and hydrogenated carbon of 15 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 90 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing fluoroethylene copolymer with vinyl ether 10.5 hexagonal zinc sulfide crystal structure 60.0 selenium 1,08 sulfur 0.35 tin dibutyl dilaurate 0.15 wetting agent 0.35 hexamethylene diisocyanate 3,5 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 5. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 20 wt.% And hydrogenated carbon of 80 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 55 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 12.5 hexagonal zinc sulfide crystal structure 75.0 selenium 1,2 sulfur 0.5 tin dibutyl dilaurate 0.25 wetting agent 0.45 hexamethylene diisocyanate 4.0 toluene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 6. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 20 wt.% And hydrogenated carbon of 80 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows of 1: 1. The rows of threads in the upper layer made an angle of φ = 125 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 7.5 hexagonal zinc sulfide crystal structure 40,0 selenium 1,2 sulfur 0.2 tin dibutyl dilaurate 0.25 wetting agent 0.45 hexamethylene diisocyanate 4.0 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 7. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 20 wt.% And hydrogenated carbon of 80 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 60 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 10.0 hexagonal zinc sulfide crystal structure 50,0 selenium 1,0 sulfur 0.35 tin dibutyl dilaurate 0.15 wetting agent 0.35 hexamethylene diisocyanate 3.4 toluene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 8. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 20 wt.% And hydrogenated carbon of 80 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 90 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 10,2 hexagonal zinc sulfide crystal structure 59.0 selenium 0.85 sulfur 0.35 tin dibutyl dilaurate 0.11 wetting agent 0.36 hexamethylene diisocyanate 3.3 toluene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 9. A protective coating was obtained in the form of two layers of interwoven rows of aramid yarns coated with a 500 nm thick film of hydrogenated carbon with cobalt particles embedded in it up to 0.05 μm in size with a cobalt content of 20 wt.% And hydrogenated carbon of 80 wt. % in the upper layer and with a cobalt content of 60 wt.% and hydrogenated carbon of 40 wt.% in the lower layer. Films were obtained by magnetron sputtering of graphite and cobalt targets in an argon-hydrogen working medium at a pressure of 5 mTorr, with an argon content of 80 wt.% And hydrogen of 20 wt.%, With an ion current density of 10 ^-2 A / cm ² , a film growth rate of 5 nm / min and with a ratio of carbon and cobalt flows 1: 1. The rows of threads in the upper layer made an angle of φ = 120 ° with the rows of threads in the lower layer. The layers were bonded with a rubber compound adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 10.3 hexagonal zinc sulfide crystal structure 64.0 selenium 0.9 sulfur 0.34 tin dibutyl dilaurate 0.11 wetting agent 0.35 hexamethylene diisocyanate 3.4 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 10. Under the same conditions as in example 1, a protective coating was obtained in the form of four layers of interwoven rows of glass fiber strands coated with a 700 nm thick film of hydrogenated carbon with nickel particles embedded in it up to 0.05 μm in size. The upper layer contained particles of nickel 20 wt.% And hydrogenated carbon 80 wt.%, In the second top layer contained particles of nickel 35 wt.% And hydrogenated carbon 65 wt.%. The third layer contained particles of nickel 45 wt.% And hydrogenated carbon 55 wt.%, And the fourth (lower) layer contained particles of nickel 60 wt.% And hydrogenated carbon 40 wt.%. The rows of threads in each layer made an angle of φ = 60 ° with the rows of threads of the adjacent layer. The layers were bonded with an epoxy-based adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 10,4 hexagonal zinc sulfide crystal structure 64.0 selenium 0.9 sulfur 0.34 tin dibutyl dilaurate 0.12 wetting agent 0.36 hexamethylene diisocyanate 3.45 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 11. Under the same conditions as in example 1, a protective coating was obtained in the form of four layers of interwoven rows of glass fiber filaments with a 700 nm thick film of hydrogenated carbon coated with nickel particles up to 0.05 μm embedded in it. The upper layer contained particles of nickel 20 wt.% And hydrogenated carbon 80 wt.%, In the second top layer contained particles of nickel 35 wt.% And hydrogenated carbon 65 wt.%. The third layer contained 45 wt.% Nickel particles. % and hydrogenated carbon 55 wt.%, and in the fourth (lower) layer contained particles of nickel 60 wt.% and hydrogenated carbon 40 wt.%. The rows of threads in each layer made an angle of φ = 90 ° with the rows of threads of the adjacent layer. The layers were bonded with an epoxy-based adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 10.8 hexagonal zinc sulfide crystal structure 68.0 selenium 0.95 sulfur 0.37 tin dibutyl dilaurate 0.15 wetting agent 0.36 hexamethylene diisocyanate 3.6 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 12. Under the same conditions as in Example 1, a protective coating was obtained in the form of four layers of interwoven rows of glass fiber filaments with a 700 nm thick film of hydrogenated carbon coated with nickel particles embedded in it up to 0.05 μm in size. The upper layer contained particles of nickel 20 wt.% And hydrogenated carbon 80 wt.%, In the second top layer contained particles of nickel 35 wt.% And hydrogenated carbon 65 wt.%. The third layer contained particles of nickel 45 wt.% And hydrogenated carbon 55 wt.% And the fourth (lower) layer contained particles of nickel 60 wt.% And hydrogenated carbon 40 wt.%. The rows of threads in each layer made an angle of φ = 120 ° with the rows of threads of the adjacent layer. The layers were bonded with an epoxy-based adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 11.0 hexagonal zinc sulfide crystal structure 71.9 selenium 1,1 sulfur 0.4 tin dibutyl dilaurate 0.2 wetting agent 0.4 hexamethylene diisocyanate 3.6 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 13. Under the same conditions as in example 1, a protective coating was obtained in the form of four layers of interwoven rows of glass fiber filaments with a 1500 nm thick film of hydrogenated carbon coated with nickel particles up to 0.05 μm embedded in it. The upper layer contained particles of nickel 20 wt.% And hydrogenated carbon 80 wt.%, In the second top layer contained particles of nickel 35 wt.% And hydrogenated carbon 65 wt.%. The third layer contained particles of nickel 45 wt.% And hydrogenated carbon 55 wt.%, And the fourth (lower) layer contained particles of nickel 86 wt.% And hydrogenated carbon 14 wt.%. The rows of threads in each layer made an angle of φ = 55 ° with the rows of threads of the adjacent layer. The layers were bonded with an epoxy-based adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 11.2 hexagonal zinc sulfide crystal structure 73.0 selenium 1,2 sulfur 0.5 tin dibutyl dilaurate 0.25 wetting agent 0.5 hexamethylene diisocyanate 3.8 xylene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

Example 14. Under the same conditions as in example 1, a protective coating was obtained in the form of four layers of interwoven rows of glass fiber filaments with a 1500 nm thick film of hydrogenated carbon coated with nickel particles embedded in it with nickel particles up to 0.05 μm in size. The upper layer contained particles of nickel 20 wt.% And hydrogenated carbon 80 wt.%, In the second top layer contained particles of nickel 35 wt.% And hydrogenated carbon 65 wt.%. The third layer contained particles of nickel 45 wt.% And hydrogenated carbon 55 wt.% And in the fourth (lower) layer contained particles of nickel 60 wt.% And hydrogenated carbon 40 wt.%. The rows of threads in each layer made an angle of φ = 125 ° with the rows of threads of the adjacent layer. The layers were bonded with an epoxy-based adhesive. The outer layer is coated with paint from the composition in the form of a suspension of the following composition (wt.%):

hydroxyl-containing copolymer fluoroethylene with vinyl ether 7.5 hexagonal zinc sulfide crystal structure 40,0 selenium 0.7 sulfur 0.2 tin dibutyl dilaurate 0.08 wetting agent 0.2 hexamethylene diisocyanate 2,8 toluene rest.

The measurement results of the reflection coefficient R, the range of absorption frequencies, thickness, weight of the resulting protective coating, the coefficients ε _3-5 , ε _8-14 , R _1,06 , R _10,6 , ρ and color coordinates x; y; z are given in table 2.

From the above examples it follows that in the manufacture of protective coatings with a content of particles of ferromagnetic material of less than 5 wt.% In a film of hydrogenated carbon on the outer layer of rows of interwoven threads and more than 85 wt.% In a film deposited on a layer of rows of interwoven threads adjacent to the protected surface, there is a deterioration in the properties of the coating, in particular, a decrease in the absolute value of the reflection coefficient | (R) | below the minimum acceptable value (10 dB) and narrowing the frequency range of radio absorption.

In the manufacture of protective coatings with the direction of the rows of strands of an adjacent layer at an angle of less than 60 ° and more than 120 °, the properties of the coating deteriorate, in particular, a decrease in the absolute value of the reflection coefficient | (R) | below the minimum acceptable value (10 dB) and narrowing the frequency range of radio absorption.

When the content of the fluorinated polymer is less than 9.5 wt.% And more than 11.0 wt.%, The coverage in the infrared region of the spectrum deteriorates (R _1.06 ; R _10.6 ).

When the content of selenium and sulfur outside the formulation, i.e. when the content of selenium is less than 0.8 wt.% and more than 1.1 wt.%; sulfur less than 0.3 wt.% and more than 0.4 wt.%, optical indicators in the visible and infrared spectral ranges change for the worse (R _1.06 , R _10.6 , ρ, x, y, z).

When the content of the wetting agent is less than 0.3 wt.% And more than 0.4 wt.%, The optical properties of the coating deteriorate (R _1.06 , R _10.6 , ρ, x, y, z), since dispersion efficiency in the system is not ensured polymer - filler (with a wetting agent content of less than 0.3 wt.%), as well as the presence of its residues (with a wetting agent content of more than 0.4 wt.%).

When the catalyst content is less than 0.1 wt.% And more than 0.2 wt.%, The optical properties of the coating deteriorate (R _1.06 , R _10.6 , ρ, x, y, z), which is explained by insufficient (for entering into the reaction curing) the amount of catalyst when its content is less than 0.1 wt.%; and the presence of its residues that did not enter the rejection reaction (with a catalyst content of more than 0.2 wt.%).

When the hardener content is less than 3.2 wt.% And more than 3.6 wt.%, The optical properties of the coating deteriorate (R _1.06 , R _10.6 , ρ, x, y, z), since with an insufficient hardener content (less than 3 , 2 wt.%) The coating does not dry out, has stickiness, the practical use of the coating is impossible; and with a hardener content of more than 3.6 wt.%, its unreacted residues plasticize the coating, reducing its hardness, and worsen the properties of the coating.

Thus, the claimed protective coating is effectively absorbing microwave radiation material at frequencies greater than 5 GHz, providing a reduction in thermal radiation in the transparency windows of the atmosphere (3-5) microns and (8-14) microns, respectively, with values of the coefficients of directed radiation at 300 K _3-5 = 0.58-0.75 and ε _8-14 = 0.7-0.8; specular reflection at wavelengths of 1.06 μm and 10.6 μm with reflection coefficients R _1.06 = 0.03-0.04; R _10.6 = 0.01-0.03, respectively; reflection coefficient in the range of 0.4-0.8 microns ρ - 0.25-0.31; color coordinates x = 24.5-28.8; y = 25.4-30.6; z = 33.1-36.6.

Claims (9)

1. A protective coating comprising a base of two or more layers of interwoven rows of threads bonded with a translucent material, with a hydrogenated carbon film deposited on each layer with particles of ferromagnetic material embedded in it, with the direction of the interwoven rows of threads of one layer being in the direction of interwoven the rows of strands of an adjacent layer an angle of 60-120 °, and the content of particles of ferromagnetic material is from 5 wt.% in the film deposited on the outer layer of interwoven rows ite, up to 85 wt.% in the film, deposited on a layer of interwoven rows of threads adjacent to the surface to be protected, while on the surface of the film applied to the outer layer of interwoven rows of threads, a paint coating is obtained by applying and drying a composition comprising a hydroxyl-containing copolymer fluoroethylene with vinyl ether, hexamethylene diisocyanate, hexagonal crystal zinc sulfide, selenium, sulfur, tin dibutyl dilaurate catalyst, wetting agent in the form of an electrically neutral salt poly . Arbonovoy acid with amine derivatives in the form of a 50% solution in aromatic high-molecular compounds and the organic solvent with the following contents of ingredients, wt%:
hydroxyl-containing fluoroethylene copolymer with vinyl ether 9.5-11.0 hexagonal zinc sulfide crystal structure 47.5-71.9 hexamethylene diisocyanate 3.2-3.6 selenium 0.8-1.1 sulfur 0.3-0.4 catalyst 0.1-0.2 wetting agent 0.3-0.4 solvent rest 2. The protective coating according to claim 1, characterized in that xylene or toluene is used as a solvent in the composition. 3. The protective coating according to claim 1, characterized in that the layers of interwoven rows of threads are made in the form of a woven fabric. 4. The protective coating according to claim 1, characterized in that the threads are made of aramid fibers. 5. The protective coating according to claim 1, characterized in that the threads are made of fiberglass. 6. The protective coating according to claim 1, characterized in that the said film is deposited on one side of each layer of interwoven rows of threads. 7. The protective coating according to claim 1, characterized in that the said film is applied on two sides of each layer of interwoven yarns. 8. The protective coating according to claim 1, characterized in that a metal selected from the group: cobalt, nickel, iron, samarium, their alloys, barium ferrite doped with rare earth elements, nickel-zinc ferrite with a titanium additive is introduced as a ferromagnetic material; manganese-zinc ferrite with a titanium additive. 9. The protective coating according to claim 1, characterized in that an adhesive composition based on a rubber or epoxy mixture is introduced as a radiolucent material.

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