RU2469761C1 - Microcapsulated fire-extinguishing agent, method of its obtaining, fire-extinguishing composite material and fire-extinguishing coating - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: polymer coating is made of hardened spatially cross-linked polymer material, filled with nanoparticles of mineral filling agent in form of 1-5 nm thick plates, and possesses ability of explosion-like destruction in temperature range 90-270°C. In particular, coating can be formed by complex of polyvinyl alcohol with urea-resorcinol-formaldehyde resin or cross-linked gelatin, filled with exfoliated montmorillonite. Also described is method of obtaining microcapsulated fire-extinguishing agent, fire-extinguishing composite materials, for instance, made in form of pastes, plates, films, products, hard foams, fabrics, and fire-extinguishing coating, which contains in its composition said microcapsulated fire-extinguishing agent.

EFFECT: inventions ensure obtaining fire-extinguishing agent, possessing higher barrier properties in its application as efficient reactive fire-extinguishing filling agent and having high stability under storage and exploitation conditions.

31 cl, 4 dwg, 2 tbl, 18 ex

Description

The present invention relates to methods for creating microcapsules containing a core from a target liquid inside a spherical shell, which provides a predetermined opening temperature of the microcapsule to release the target liquid contained in the microcapsule in the intended medium of use, having a certain elevated temperature, for example, fire extinguishing agent microcapsules that are effective in quenching fire of different nature, and created using the specified extinguishing agent fire extinguishing composite material, fire asyaschemu coating and extinguishing tissue. The invention can also be used for any microcapsules containing low-boiling, water-immiscible liquids and the volatiles contained in them, in order to increase the barrier properties of the shell and, accordingly, the stability of the microcapsules during storage and operation.

The problem of microencapsulation of various target products with the creation of a microcapsule that is stable under certain environmental conditions and provided with a shell that does not affect the properties of the target product contained in it and ensures the release of the target product under certain environmental parameters leading to biodegradation, dissolution or rupture of the shell, is very relevant .

The most difficult problems are microencapsulation of the target products, which are volatile or gasified when heated, which is associated with the problem of creating shells having high strength and low permeability when heated and at the same time ensuring destruction or opening of the shell at a given temperature to ensure the most efficient use of microcapsule of the target product.

So, microcapsules are known with the content of essential oils in a spherical core with a shell in the form of a thin external polymer membrane polyurea or polyurethane film around droplets of the specified essential oil, which controls the release of essential oil and protects it from oxidation and evaporation, and also provides an effective dose of oils with a constant constant speed for a long period of time (RU 2347608 C2). Microcapsules can be used in the production of disinfectant and repellent compositions, indoor air fragrances.

However, to ensure the rate of decomposition of the shells of microcapsules or to ensure a given permeability of the shells, the strength issues of the shells were secondary, and the created microcapsules were not sufficiently stable under mechanical and temperature loads.

Microcapsules are known for vulcanization of natural and synthetic rubbers (RU 2376058 C2), including a core containing at least one rubber additive in the polymer wall of the capsule formed by melamine-formaldehyde resin and polyurea resin and polyelectrolyte. Microcapsules are thermally and mechanically stable up to 120-140 ° С, however, at a higher temperature, the rate of destruction of the shells of microcapsules and the temperature of their destruction are not the same for all microcapsules, which can affect the rubber vulcanization process.

The most difficult to solve are the problems of the release of the contents of the microcapsules at the same time, for example, during the explosive destruction of the shells of the microcapsules at a certain ambient temperature.

It is known that work on extinguishing fire using fire extinguishing agents in a liquid, gaseous state or in the form of an aerosol presents certain difficulties, and known fire extinguishing agents do not allow the full use of the effectiveness and capabilities of the extinguisher.

Among the commonly used extinguishing agents, gaseous or liquid halogenated (fluoro, bromo, chloro, and iodo substituted) hydrocarbons are extremely effective.

As a fire extinguishing agent using fluorine-substituted hydrocarbons, a fire-suppressing agent is known having a non-combustible partially or completely fluorine-substituted hydrocarbon with a boiling point above 0 ° C in combination with a gas creating pressure to release the agent in a sprayed form in the protected zone (GB 2265309 A ) The fire suppression effect is associated with the fact that a high-density fire-extinguishing gas creates a non-combustible atmosphere, which prevents air from entering the surface having a high temperature, and fluorine radicals generated as a result of decomposition of the fluorine-substituted hydrocarbon by a flame having a high temperature interrupt the kinetic combustion chain.

Tetrafluorodibromoethane under the trade name Freon 114B2 and a number of other bromofluorinated hydrocarbons (Halogen-containing extinguishing agents, TEZA Publishing House, St. Petersburg, 1999) are widely known as a fire extinguisher (OG) for volumetric extinguishing.

Since when extinguishing electrical equipment by the indicated agents, short circuits and damage do not occur, they can be used even in places where water, fire extinguishing foam and inorganic carbonate powder cannot extinguish the fire and cause irreparable damage to electrical and electronic equipment. Fire extinguishing agents containing halogenated hydrocarbons are suitable for extinguishing fires at structures on the seabed and offshore, on aircraft, in archives, at nuclear power plants and other structures.

However, these extinguishing agents, consisting of these halogenated hydrocarbons, have a fundamental drawback, since they destroy the ozone layer in the atmosphere. In accordance with this Montreal Protocol of 1987, the production of these halogenated hydrocarbons is prohibited, and the import of these products to most countries is prohibited. For Russia, their use is limited by available reserves and regenerated components, their reserves are depleted.

As a result of studies of possible alternatives, bromine-substituted hydrocarbons were proposed as liquid gasifying fire extinguishing agents that do not accumulate in the atmosphere (WO 98/15322; Fire Safety, No. 4, 2005, pp. 79-82). However, most bromine-substituted hydrocarbons converted to gas are not used in fire extinguishing due to extremely high volatility. For this reason, when used in concentrations close to the concentrations necessary for extinguishing fire with other extinguishing agents, the practical effectiveness of brominated hydrocarbons was lower.

The search and creation of new extinguishing gasifying liquids, characterized by high extinguishing efficiency, environmental friendliness and safety for people, continues in the world with great intensity.

There are reports of the development by the company 3M (USA) of a new fire extinguishing liquid gasifying agent, which is perfluoroethyl-perfluoroisopropyl ketone (hereinafter abbreviated as “perfluoroketone”): formula CF ₃ CF ₂ COCF (CF ₃ ) ₂ , d ²⁰ = 1 6 g / ml, T _boiling. = + 49.2 ° C, T _deputy. = (- 108) ° С, saturated steam pressure at 25 ° С - 40.4 kPa (at water 3.2 kPa), hazard class 4. This extinguishing agent is completely safe for the ozone layer of the stratosphere, does not apply to "greenhouse gases" It is safe for people even in the conditions of extinguishing a fire, its effectiveness allows you to stop the fire until a dangerous concentration of combustion products is achieved, and there is no need for urgent evacuation of people from the premises. The agent was introduced to the market of many countries under the trade name "Novec 1230" (S. Dauenhauer. "Comparison of fire extinguishing systems", the journal "Security Algorithm". No. 3, 2009). However, this agent is offered in the form of a liquid, which significantly increases the cost and complicates its transportation and makes it necessary to use it under increased pressure in special fire extinguishing equipment.

Therefore, by encapsulating such extinguishing liquids in microcapsules, microencapsulated powder extinguishing agents have been developed that automatically release the extinguishing gas at high temperatures and deliver gas to the combustion center to the maximum extent possible.

Known closest to the present invention is safe for the ozone layer dispersed in a thermosetting polymer binder microencapsulated extinguishing agent (RU 2161520 C1), in which the microcapsule is a microsphere with a diameter of 100-400 μm, having a spherical shell of cured gelatin and enclosed inside a shell of liquid fire extinguishing substance, which is used as the substance class of halogenated hydrocarbons and certain amines having the formula C ₃ F ₇ I (ftoriodidy) or C _n F _{2n + 2} where n = 5-7, for (C ₂ F _{5) 2} N (C _m F _{2m + 1)} (fluoroamines), where m = 1 or m = 2. Microcapsules are opened in the temperature ranges 130-149 ° C and 166-190 ° C. However, the achieved stability of the material, necessary for its practical application, was insufficient. In addition, these fluorine-substituted hydrocarbons and fluorinated amines were banned for use by the Kyoto Agreement in 1997 due to the fact that they cause a “greenhouse effect”.

It is known to create structural materials that counteract fire, which use fire extinguishing agents in a convenient microencapsulated form, in the form of a powdery filler.

For example, a fire extinguishing foam plastic has been proposed (JP 57-195128 A) in which very small polymer capsules containing liquid halogenated hydrocarbon are dispersed, and foaming is carried out at a temperature lower than the temperature of explosive fracture of these small polymer capsules. A fire extinguishing oil or water based paint (JP 58-132056 A) is proposed in which very small polymer capsules containing a halogen-substituted hydrocarbon are mixed. At the same time, dibromotetrafluoroethane, bromochloroethane and bromochlorodifluoromethane were used as halogenated hydrocarbons.

It is known to use microencapsulated 1,1,2,2-tetrafluorodibromoethane, 1,2-dibromotetrafluoroethane in a composition for a fire extinguishing coating (RU 1696446 C).

To increase the stability of microcapsules containing, for example, dibromoethane, a double-shell microencapsulation method was proposed — polysiloxane and gelatin (RU 2389525). Despite the obtained certain effect on the stabilization of microcapsules, it was later shown that it does not allow to obtain stable microcapsules with a number of other volatile extinguishing liquids.

Thus, the problem of creating microencapsulated extinguishing agents that are convenient and effective in applying for suppressing fire both in the form of microcapsule powder and in the composition of polymeric extinguishing materials as fillers is a very urgent problem.

The aim of the present invention is to obtain a microencapsulated extinguishing agent containing microcapsules having a core of fire extinguishing liquid gasifying low boiling substances, in shells having enhanced barrier properties when using this agent as an effective reactive fire extinguishing filler for extinguishing structural polymer materials and to increase the extinguishing efficiency of due to the safety of the liquid from evaporation and ensuring explosive destruction microcapsules at a given temperature and providing, accordingly, high stability of microcapsules in storage and operation.

The authors investigated the well-known methods of microencapsulation of liquid gasifying halogenated hydrocarbons, including simple and complex coacervation with the formation of gelatin shells of different compositions (M.S. Vilesova, M.S. Bosenko, A.D. Vilesov, etc. Development of microencapsulated and gel-like products and materials for various industries.Russian Chemical Journal, vol. XLV, No. 5-6, 2001, p.125-129; RU 2161520 C1; RU 2382595 C1) and shells of urea-formaldehyde-resorcinol resins (M.S. Vilesova, R.P. Stankevich, Bosenko M.S. and other Russians chemical journal, vol. XLV, No. 5-6, 2001, p. 131; US 3,755,190 V). However, these methods failed to obtain physically stable microcapsules containing, for example, the above perfluoroketone. The instability of microcapsules obtained by known methods with a perfluoroketone core, expressed in the loss of a liquid fire extinguisher as a result of evaporation through the shell, is due to the structure of perfluoroketone molecules with extremely high diffusion ability.

At the same time, the authors concluded that the increase in the physical stability of microcapsules should be associated with the improvement of the shell of the microcapsule, in particular, an increase in its density and modification of its structure.

When creating the invention, the task was to create a microencapsulated extinguishing agent containing microcapsules having a core of extinguishing liquid gasifying low-boiling substances in shells with enhanced barrier properties and explosive destruction at a certain temperature, due to the formation of frame structural elements associated with polymer binder and having a certain size, and forming a layered structure in a polymer base shell parallel to microcapsules of the nucleus, providing a substantial increase in the possible path of fluid through the diffusion core shell microcapsules and increase the packing density of the shell polymer chains.

Based on the above arguments, fillers in the form of mineral nanoparticles in the form of nanoscale plates of nanoscale thickness were selected for the research direction.

Analyzing various known methods of microencapsulation of volatile water-insoluble liquids, which mainly include previously known extinguishing liquids and Novec 1230 perfluoroketone, the authors came to the conclusion that only methods based on the coacervation principle can be applied to solve this problem. It was at the stage of phase separation and isolation of coacervate droplets in the initial solution of polymers containing the bulk of the polymers to form the shell, the authors proposed to introduce the indicated mineral plates into coacervate droplets. This was achieved by creating complexes "polymer - nanoscale particle". To this end, starting polymers were used that have basic functional groups in the macromolecule or in its constituent components, which ensure the formation of a complex on the surface of a mineral nanoscale plate having acidic functional groups. Only under this condition it was possible to obtain the effect of involving nanoscale plates in a coacervate drop, together with polymer macromolecules, and then ensure their location in the shell material. It was shown in experiments that up to 90 wt.% Of the mineral filler introduced into the initial reaction medium was able to be concentrated in coacervate drops and in the composition of the microcapsule shell.

Aluminosilicates were used as sources of such mineral plates: the natural mineral montmorillonite (MMT), contained in bentonite clays, and its synthetic analogues. Moreover, it was known that MMT was used in the form of nanosized plates to modify the properties of polymers, for example polyimides (V.E. Yudin, V.M. Svetlichny. The effect of the structure and shape of filler nanoparticles on the physical properties of polyimide composites. Russian Chemical Journal, 2009, Volume 53 No. 4, pp. 75-85. VEYudin, GM Divoux, JUOtaigbe, VMSvetlichnyi. Synthesis and rheological properties of oligoimide / montmorillonite nanocomposites. Polymer, v. 46, 2005, pp. 10866-10872). In all these works, MMT plates were used after special modification of their surface with organic compounds and their subsequent introduction into melts or polymer solutions to obtain block systems.

To obtain MMT nanoparticles in the form of plates, the authors subjected the powdery natural MMT to exfoliation - separation of the initial powder particle into elementary structural units - folia, which are nanosized particles in the form of plates having a thickness within 1-2 nm (during exfoliation) and up to 5 nm ( in case of partial intercalation).

Information on the use of MMT to increase the barrier properties of microcapsule shells and on the methods for introducing nanoscale plates into the microcapsule shell, as well as on the effect of such “inlay” on the permeability of the shells and, accordingly, the stability of microcapsules with a core of volatile liquids, is not known to the authors.

The problem was solved by creating a microencapsulated extinguishing agent containing microcapsules having a core of spatially crosslinked polymer material placed inside a spherical polymer shell, a core of fire-extinguishing liquid, characterized in that the polymer shell contains nanoparticles of a mineral filler in the form of plates having a thickness of 1- 5 nm, and has the ability of explosive destruction in the temperature range of 90-270 ° C.

Moreover, according to the invention, it is desirable that the polymer material of the shell is a complex of polyvinyl alcohol and urea-resorcinol-formaldehyde resin.

Moreover, according to the invention, it is possible that the polymer material of the shell is crosslinked gelatin.

Moreover, according to the invention, it is advisable that the nanoparticles of the mineral filler were made in the form of nanoscale plates of natural montmorillonite aluminosilicate or its analogues in an exfoliated state.

Moreover, according to the invention, it is desirable that the shell contains the indicated nanoparticles of the mineral filler in an amount of 1-5% by weight of the shell.

Moreover, according to the invention, it is possible for said microcapsule to have an outer diameter in the range of 50-400 microns.

Moreover, according to the invention, it is advisable that the core contains extinguishing fluid in an amount of 75-95% by weight of the microcapsule.

Moreover, according to the invention, it is possible that the core contains perfluoroethyl perfluoroisopropyl ketone.

In addition, according to the invention, it is possible that the core contains dibromomethane.

In addition, according to the invention, it is possible for the core to contain a bromine-containing or fluorine-bromine-containing fire extinguishing liquid.

In addition, according to the invention, it is possible for the core to contain a mixture of extinguishing fluids selected from the group consisting of: perfluoroethyl perfluoroisopropyl ketone, dibromomethane, brominated hydrocarbons and fluorinated brominated hydrocarbons in a liquid state.

The problem was also solved by the development of a method for producing a microencapsulated extinguishing agent containing microcapsules having a core of a spatially crosslinked polymer inside a spherical polymer shell, a core of fire extinguishing liquid, in which the polymer shell contains nanoparticles of a mineral filler in the form of plates having a thickness of 1- 5 nm, and has the ability of explosive destruction in the temperature range 90-270 ° C, in which they carry out:

a) preparing a suspension containing nanoparticles of an exfoliated mineral filler by mixing the powdered mineral filler with distilled water and treating the suspension with ultrasound until the reaction mixture becomes clear, preserving slight opalescence;

b) preparing an aqueous solution of the starting polymer shell material and mixing it with the suspension obtained in stage a);

c) emulsification of the extinguishing fluid to be placed in the core of the microcapsule in an aqueous solution of a polymeric shell material containing nanoparticles of a mineral filler obtained in stage b);

d) the phased formation of the emulsion obtained in stage c) on the drops by the coacervation method, including drop separation of phases, sorption of the coacervate drops on the surface of the drops of the extinguishing liquid emulsion and their coalescence to obtain liquid shells;

d) curing the shells with the formation of microcapsules, washing the microcapsules with water, filtering and drying them.

Moreover, according to the invention, it is possible that a complex of polyvinyl alcohol and urea-resorcinol-formaldehyde resin be used as the polymeric material of the shell.

Moreover, according to the invention, it is possible in step d) to form a shell by adding a fire-extinguishing liquid to the emulsion in a solution of polyvinyl alcohol obtained in step c), a mixture of an aqueous solution of urea with resorcinol and formaldehyde and lowering the pH to 1.2, and in step d ) curing of the shells is carried out by increasing the temperature to 45 ° C and holding at the indicated temperature for 3.5 hours.

In addition, according to the invention, it is possible that crosslinked gelatin is used as the polymer material of the shell.

Moreover, according to the invention, when using crosslinked gelatin as a polymeric material, it is possible in step g) to form the shell by adding an extinguishing liquid to the emulsion in the gelatin solution obtained in step c), an aqueous solution of sodium polyphosphate, lowering the pH to 4.0-4 5, subsequent cooling of the emulsion to 5-10 ° C, and in step d) curing of the shells is carried out by adding glutaraldehyde, holding at the indicated temperature for at least 1.0 hour, raising the temperature to 20-25 ° C, p underreporting pH of the mixture to 1.0-2.0, adding resorcinol and formaldehyde, at temperature 30-35 ° C for 30-40 min.

In addition, according to the invention, it is possible in step g) to form a shell by adding an extinguishing liquid to the emulsion in the gelatin solution obtained in step c), an aqueous solution of sodium polyphosphate, lowering the pH of the medium to 4.0-4.5, then cooling the emulsion to 5-10 ° C, and at the stage d) curing of the shells is carried out by adding glutaraldehyde and exposure at the indicated temperature for at least 5.0-6.0 hours.

Moreover, according to the invention, it is advisable to use nanoparticles made in the form of nanosized plates of natural montmorillonite aluminosilicate or its analogs in an exfoliated state as nanoparticles of a mineral filler.

Moreover, according to the invention, it is possible to obtain microcapsules having an outer diameter in the range of 50-400 microns.

In addition, according to the invention, it is possible to obtain microcapsules in which the core contains fire extinguishing liquid in an amount of 75-95% by weight of the microcapsule.

Moreover, according to the invention, it is possible to use perfluoroethyl perfluoroisopropyl ketone as a fire extinguishing liquid.

In addition, according to the invention, it is possible to use dibromomethane as an extinguishing liquid.

In addition, according to the invention, it is possible to use a bromine-containing or fluorobromine-containing fire-extinguishing liquid as an extinguishing liquid.

In addition, according to the invention, it is possible to use a mixture of fire extinguishing liquids selected from the group consisting of: perfluoroethyl-perfluoroisopropyl-ketone, dibromomethane, brominated hydrocarbons, fluorinated brominated hydrocarbons in a liquid state as an extinguishing liquid.

The problem was also solved by the creation of an extinguishing composite material containing a cured resin or cured rubber, including a microencapsulated extinguishing agent dispersed therein, made according to the invention.

Moreover, according to the invention, it is possible that the material was made in the form of foam.

In addition, according to the invention it is possible that the material was made in the form of a curable paste.

In addition, according to the invention it is possible that the material was made in the form of a structural element.

In addition, according to the invention it is possible that the material was made in the form of a film.

In addition, according to the invention, it is possible for the material to be in the form of an extinguishing fabric, impregnated or coated with a curable paste containing resin or rubber, including a microencapsulated extinguishing agent dispersed therein, made according to the invention.

The problem was also solved by creating an extinguishing coating of paint containing dispersed microencapsulated extinguishing agent dispersed in it, made according to the invention.

The invention is further illustrated by the description of the microencapsulated extinguishing agent, the implementation of the method for its production and extinguishing structural materials and paints using it, not going beyond the scope of patent claims and not limiting the possibility of carrying out the invention, and the accompanying drawings, in which:

Figure 1 - data on the loss of dibromomethane from the core of microcapsules of a microencapsulated extinguishing agent having a shell of gelatin: line 1 - with a shell without filler; line 2 - with a shell with a filler in the form of nanoparticles - plates of montmorillonite;

Figure 2 - data on the loss of perfluoroketone from the core of microcapsules of a microencapsulated extinguishing agent having a shell of a mixture of polyvinyl alcohol with urea-resorcinol-formaldehyde resin: line 3 - with a shell without a filler; line 4 - with a shell with a filler in the form of nanoparticles of montmorillonite plates;

Figure 3 - data on the loss of perfluoroketone from the core of microcapsules of a microencapsulated extinguishing agent having a shell of gelatin: line 5 - with a shell without a filler; line 6 - with a shell with a filler in the form of nanoparticles of montmorillonite plates;

Figure 4 - data of thermogravimetric analysis of microcapsules of a microencapsulated extinguishing agent with a core of Novec 1230 perfluoroketone and a shell of gelatin: line 7 - with a shell without a filler; line 8 - with a shell with nanoparticles in the form of nanoscale plates of montmorillonite with a shell without filler.

A microencapsulated extinguishing agent according to the invention, containing microcapsules having a core of a spatially crosslinked polymeric material inside a spherical polymer shell, a core of fire-extinguishing liquid and in which the shell contains nanoparticles of a mineral filler in the form of nanoscale plates having a thickness of 1-5 nm, and when the shell of the microcapsule has the ability of explosive destruction in the temperature range 90-270 ° C, can be obtained by the method according to the invention using various water-insoluble fire extinguishing liquids to form a core and various polymeric materials with a mineral filler in the form of nanoparticles in the form of plates for forming a shell.

Upon receipt of the microcapsules, the formation of the polymer – nanoscale particle complexes was ensured due to the connection of the main functional groups of the polymer with the acidic functional groups of the mineral nanoparticle at the stage of phase separation and isolation of coacervate droplets in the initial polymer solution containing the bulk of the polymers for shell formation.

Moreover, when implementing the method for producing the microencapsulated extinguishing agent according to the invention, the following operations were performed:

a) preparing a suspension containing nanoparticles of an exfoliated mineral filler by mixing the powdered mineral filler with distilled water and treating the suspension with ultrasound at a frequency of 20-35 kHz for 1.5 hours, until the reaction mass is clear, preserving slight opalescence;

b) preparing an aqueous solution of the starting polymer shell material and mixing it with the suspension obtained in stage a);

c) emulsification of the extinguishing fluid to be placed in the core of the microcapsule in an aqueous solution of a polymeric shell material containing nanoparticles of a mineral filler obtained in stage b);

d) the gradual formation on the droplets of the emulsion obtained in stage c), the shell by the coacervation method, including drop separation of phases, sorption of the coacervate droplets on the surface of the droplets of the extinguishing liquid emulsion and their coalescence to obtain liquid shells;

d) curing of the shells with the formation of microcapsules, their filtration and drying.

Moreover, the operations c), d) and e) were performed as follows:

- in the case of using a complex of polyvinyl alcohol and urea-resorcinol-formaldehyde resin as a polymer material for the shell, the formation of the shell was carried out by adding a fire-extinguishing liquid obtained in stage c) and heated to 35 ° C, a mixture of an aqueous solution of urea with resorcinol and formaldehyde, lowering the pH of the medium to 1.2. In this case, the formation of microcapsule shells was carried out by sorption of coacervate microdrops on the surface of the emulsion droplets and their coalescence (fusion) with the formation of liquid shells. When a mixture of urea, formaldehyde, and resorcinol in the form of aqueous solutions was added, the nanoparticles of the mineral filler were mainly concentrated in microdroplets of the coacervate phase. Then, to harden the shell, a temperature was raised to 45 ° C and kept at the indicated temperature for 3.5 hours, cooled to room temperature, the obtained microcapsules were washed with water, filtered and dried;

- in the case of using gelatin as the polymer material of the shell, the formation of the shell was carried out by adding to the emulsion obtained in stage c), an aqueous solution of sodium polyphosphate, lowering the pH of the medium to 4.0-4.5. The formation of microcapsule shells was carried out due to sorption of coacervate microdrops on the surface of the emulsion droplets and their coalescence (fusion) with the formation of liquid shells. Moreover, it was experimentally proved that when a sodium polyphosphate solution is added, the nanoparticles of the mineral filler are predominantly concentrated in microdroplets of the coacervate phase. Then, for curing the shell, the emulsion was cooled to 5-10 ° C, glutaraldehyde was added, kept at this temperature for at least 1.0 hour, the temperature was raised to 20-25 ° C, the pH of the mixture was lowered to 1.0-2.0, resorcinol and formaldehyde were added, kept at a temperature of 30-35 ° C for 30-40 minutes, the microcapsules were washed with water, filtered and dried.

Moreover, according to the invention, it is possible to cure the shell by adding glutaraldehyde and holding at the indicated temperature for at least 5.0-6.0 hours.

It should be noted that the proposed method for producing microcapsules of a microencapsulated extinguishing agent according to the invention does not require a special technological step for modifying the surface of the filler nanoparticles, since it is combined with the main microencapsulation process in a single processing chain. This greatly simplifies and reduces the cost of the process of obtaining the shell of a microcapsule filled with MMT nanoparticles.

It was shown below in the examples that up to 90 wt.% Of the mineral filler introduced into the initial reaction medium was able to be concentrated in coacervate drops and in the composition of the microcapsule shell.

The microcapsules obtained by the method described above consist of a shell and a liquid core of the target liquid product. The shell is made of a cured spatially crosslinked polymer material containing nanoparticles of a natural mineral filler or its natural or synthetic analogue. For example, the polymeric material of the shell may be spatially crosslinked gelatin cured with glutaraldehyde and resorcinol with formaldehyde, or polyvinyl alcohol in combination with urea-formaldehyde-resorcinol resin.

The outer diameter of the obtained microcapsules is 50-400 microns, the content of the extinguishing fluid is 75-95% by weight of the entire microcapsule. The temperature of the explosive destruction of the microcapsule is in the range of 90-270 ° C, depending on the nature (including the boiling point) of the extinguishing liquid in the core. The temperature of explosive destruction is considered, respectively, a sharp bend on the mass loss curve during gravimetric investigation (hereinafter TGA) of microcapsules.

The microencapsulated extinguishing agents according to the invention, used mainly for extinguishing a fire, contain microcapsules, the core of which contains an extinguishing liquid and is surrounded by a shell. At elevated temperatures, the extinguishing fluid inside the shell overheats to temperatures well above its boiling point under normal conditions, to the critical point of explosive destruction of the shell. When the shell of the microcapsule is explosively destroyed by heat or flame, the agent releases a gasified fire extinguishing liquid in a gaseous state into the surrounding space.

Due to the powder state, the microencapsulated extinguishing agent can be used as a filler for the manufacture of structural composite materials, coatings, films and other materials, imparting fire-extinguishing properties to these materials due to the explosive destruction of the microcapsules contained in the material when the temperature rises to a certain level of destruction temperature.

The microencapsulated extinguishing agent according to the present invention can be introduced as a filler in resins, liquid curable rubbers, latexes, curable foams, in fabrics and other materials and products.

The extinguishing composite material according to the present invention contains a cured resin, or liquid cured rubber, or latex rubber, containing the microencapsulated extinguishing agent dispersed therein according to the invention.

The extinguishing coating according to the present invention is a paste comprising a curing polymer matrix and the above microencapsulated extinguishing agent according to the invention complete with a hardener.

Extinguishing foam (solid foam) according to the present invention contains a microencapsulated extinguishing agent according to the invention.

The extinguishing fabric according to the present invention is impregnated or coated with resins or other other curable binders containing a dispersed microencapsulated extinguishing agent according to the invention.

The extinguishing paint according to the present invention contains the aforementioned extinguishing agent according to the invention.

Below are the options for obtaining microcapsules according to the invention, shown in the following examples.

Moreover, to ensure the destruction of the shell and gasification of the core under the influence of heat or flame, it is preferable to use liquids having a boiling point of 45-150 ° C as extinguishing liquid. As shown in the examples, microcapsules containing liquids with such parameters have a thermal destruction range of 90-270 ° C. The choice of the lower limit is mainly dictated by the microencapsulation conditions (at temperatures of 35-45 ° C), and the upper limit - by the thermal stability of the shell material. However, some expansion of these limits is possible when creating special conditions for microencapsulation (for example, sealing the technological process of microencapsulation) and the use of additional curing of the shell. Since freezing of the extinguishing liquid can destroy the capsule shell due to a sharp decrease in the volume of the core, the extinguishing liquid should preferably have a melting point of minus 50 ° C or lower to provide possible storage and operating conditions.

In the examples, the following extinguishing liquids were used:

- liquid perfluoroketone - perfluoroethyl-perfluoroisopropyl-ketone (Examples 1, 3),

- bromo-substituted fire extinguishing liquid dibromomethane (Examples 2, 4),

- a mixture of extinguishing liquids perfluoroketone and dibromotetrafluoroethane (Example 5),

- a mixture of extinguishing liquids tribromomethane and dibromomethane (Example 6),

- tetrafluorodibromoethane (Example 7).

Example 1. Obtaining microcapsules containing the core of the fire extinguishing liquid of Novec 1230 perfluoroketone in a shell of a complex of polyvinyl alcohol with urea-resorcinol-formaldehyde resin filled with montmorillonite nanoparticles in the form of nanoscale plates

To obtain a suspension of exfoliated mineral filler in distilled water, a sample of 0.045 g of montmorillonite (powder) was placed in an ultrasonic bath, 28 g of water was poured and subjected to ultrasound at a frequency of 35 kHz for 1.5 hours. In this case, exfoliation occurred - separation of the initial particle of the powdered mineral filler into its elementary structural units - folia, which are micro-sized plates having a thickness of 1-5 nm and a plane size of about 100 nm × 200 nm. The control of achieving exfoliation is the enlightenment (transparency) of the initial suspension, which retains slight opalescence.

To carry out coacervation and subsequent preparation and curing of the shell, two solutions were obtained that differ only in the concentrations of the components:

1st solution (for the coacervation process): 0.38 g of urea, 0.9 g of resorcinol and 2.25 ml of formalin (37% by weight aqueous formaldehyde solution) were dissolved in 5.25 ml of distilled water;

2nd solution (for the curing process of the shell): 0.38 g of urea, 1.28 g of resorcinol and 5.25 ml of formalin were dissolved in 7.5 ml of distilled water.

30 ml of a 5% by weight aqueous solution of polyvinyl alcohol was placed in an apparatus with a stirrer, 18 ml of perfluoroketone (T. boiling + 49 ° C) was added with stirring to obtain an emulsion. To the resulting emulsion was added 28 ml of a suspension of nanoparticles of exfoliated montmorillonite, the temperature was raised to 35 ° C.

Then, to carry out the coacervation process, the above-mentioned 1st solution of urea-resorcinol-formaldehyde and 2 ml of sulfuric acid (10% by weight) were added.

Then the temperature of the reaction mixture was raised to 45 ° C, a 2nd solution was added and kept for 3.5 hours to cure the shell. After cooling to room temperature, the microcapsules were filtered off, washed with distilled water and dried.

A microencapsulated extinguishing agent according to the invention was obtained containing microcapsules with a diameter of 50-200 μm with a perfluoroketone content of 87% by weight of the microcapsule, the output of the microcapsules was 90%, the temperature of explosive destruction was 92 ° C.

It is allowed to initially mix a suspension of montmorillonite with a solution of polyvinyl alcohol, and then add perfluoroketone for emulsification.

Example 2. Obtaining microcapsules containing a core of dibromomethane in a shell from a complex of polyvinyl alcohol with urea-resorcinol-formaldehyde resin filled with montmorillonite nanoparticles in the form of nanoscale plates

Microcapsules were obtained by a method similar to that described in Example 1, dibromomethane with T. boil was used as an extinguishing liquid. + 98.5 ° C.

The obtained microcapsules had a diameter of 50-200 μm, the content of dibromomethane was 92% by weight of the microcapsules, the output of the microcapsules was 93%, and the temperature of explosive destruction was 220 ° C.

Example 3. Obtaining microcapsules containing the core of Novec 1230 perfluoroketone in a gelatin shell filled with montmorillonite nanoparticles in the form of nanoscale plates

A sample of 0.06 g of natural montmorillonite powder in 32 ml of distilled water was exfoliated in an ultrasonic bath at a frequency of 20 kHz for 1.5 hours to obtain a transparent, slightly opalescent suspension.

To prepare an aqueous gelatin solution, a suspension of montmorillonite nanoparticles was added to 2.0 g of gelatin, kept at room temperature for 20 minutes to swell, then heated at 50 ° C for 30 minutes.

Separate preparation of a suspension of exfoliated montmorillonite and a solution of gelatin is allowed and their subsequent mixing.

To prepare a 5% by weight aqueous solution of sodium polyphosphate, 5.0 g of sodium polyphosphate was added to 95.0 g of distilled water and stirred at 60-70 ° C for 1-2 hours.

To prepare a 15% by weight aqueous solution of resorcinol, 15.0 g of resorcinol was added to 85.0 g of distilled water and stirred at room temperature for 30 minutes.

Then, to carry out the process of coacervation and sorption of coacervate drops on the emulsion droplets, 14 ml of perfluoroketone was added to the obtained gelatin solution with nanoparticles of exfoliated montmorillonite dispersed in it at a temperature of 25 ° C, to obtain an emulsion, then 4.8 ml of 5% by weight a solution of sodium polyphosphate and 0.5 ml of 10% by weight sulfuric acid to a pH of 4.2-4.3. With a gradual decrease in temperature to 10 ° C (within two hours), a liquid shell formed.

To cure the shell, 2 ml of an aqueous 25% by weight solution of glutaraldehyde was added to the reaction mixture and kept at room temperature for 5-6 hours. The resulting microcapsules were washed with water, isolated by filtration and dried.

The obtained microcapsules had a diameter of 120-400 μm, the content of perfluoroketone was 89% by weight of the microcapsules, the output of the microcapsules was 92%, and the temperature of explosive destruction was 90 ° C.

If necessary, to increase the strength of the shell, it was cured as follows: after adding glutaraldehyde and holding for one hour, 5.2 ml of a 15% by weight aqueous solution of resorcinol was added to the reaction mass and the mixture was stirred for 15 minutes, after which it was added 10% by weight aqueous solution of sulfuric acid to lower the pH to 1.3-1.4.

Then, 8.0 ml of a 37% by weight aqueous formaldehyde solution was added, and the mixture was kept at a temperature of about 30 ° C. for 3.0 hours in order to completely solidify the gelatin shell.

Example 4. Obtaining microcapsules containing a core of dibromomethane in a shell of gelatin, filled with montmorillonite nanoparticles in the form of nanoscale plates

Microcapsules were obtained by a method similar to that described in Example 3, by curing the shell of the microcapsule.

For this, after adding a solution of glutaraldehyde to the reaction mixture and holding for 1 hour, 5.2 ml of a 15% by weight aqueous solution of resorcinol were added and the mixture was stirred for 15 minutes, after which a 10% by weight aqueous solution of sulfuric acid was added. to lower the pH to 1.3-1.4.

Then, 8.0 ml of a 37% by weight aqueous formaldehyde solution was added, and the mixture was kept at a temperature of about 30 ° C. for 3.0 hours in order to completely solidify the gelatin shell.

The obtained microcapsules had a diameter of 200-300 μm, the content of dibromomethane was 93% by weight of the microcapsules, the output of the microcapsules was 90%, and the temperature of explosive destruction was 220 ° C.

Example 5. Obtaining microcapsules containing the core of the extinguishing fluid - a mixture of 80 wt.%. perfluoroketone and 20 wt.% dibromotetrafluoroethane in a gelatin shell filled with montmorillonite nanoparticles in the form of nanoscale plates

Microcapsules were obtained as described in Example 4.

The obtained microcapsules had a diameter of 200-300 μm, the content of dibromomethane was 93% by weight of the microcapsules, the yield of microcapsules was 90%, and the temperature of explosive destruction was 100 ° C.

Example 6. Obtaining microcapsules containing the core of the extinguishing liquid of tetrafluorodibromoethane in a shell of gelatin filled with montmorillonite nanoparticles in the form of nanoscale plates

Microcapsules were obtained as described in Example 4.

The obtained microcapsules had a diameter of 200-300 μm, the content of the extinguishing liquid was 92% by weight of the microcapsules, and the temperature of explosive destruction was 120 ° C.

Example 7. Obtaining microcapsules containing the core of the extinguishing fluid - a mixture of 20 wt.%. tribromomethane and 80 wt.% dibromomethane in a gelatin shell filled with montmorillonite nanoparticles in the form of nanoscale plates

Microcapsules were obtained as described in Example 4.

The obtained microcapsules had a diameter of 200-350 μm, the content of the extinguishing liquid was 90% by weight of the microcapsules, and the temperature of explosive destruction was 270 ° C.

Example 8. Experimental confirmation of the concentration of montmorillonite nanoparticles in the form of nanoscale plates in the shell of a microcapsule (for example, a shell with gelatin as a polymer material)

A portion of 0.06 g of montmorillonite in 32 ml of distilled water was exfoliated in an ultrasonic bath at a frequency of 35 kHz for 1.5 hours to obtain a transparent, slightly opalescent suspension.

To prepare an aqueous gelatin solution, a suspension of montmorillonite nanoparticles was added to 2.0 g of gelatin, kept at room temperature for 20 minutes to swell, then heated at 50 ° C for 30 minutes.

To prepare a 5% by weight aqueous solution of sodium polyphosphate, 5.0 g of sodium polyphosphate was added to 95.0 g of distilled water and stirred at 60-70 ° C for 1-2 hours.

To carry out the coacervation process at a temperature of 40 ° C, 4.8 ml of sodium polyphosphate solution (5% by weight) and 0.5 ml of sulfuric acid (10% by weight) were added to pH 4 to the resulting gelatin solution with exfoliated montmorillonite nanoparticles. 2-4.3. The resulting reaction mass was held for 2.0 hours to merge the coacervate drops into a continuous phase. The coacervate phase and the continuous phase were separated and dried to constant weight.

In the dry residue, the silicon content was determined (by atomic absorption analysis) and the gelatin content (by gravimetric method).

In the dry residue of the coacervate phase (shell material) was found:

Gelatin - 1.3 g, silicon content - 1.6 wt.% = 0.021 g.

In the dry residue of the continuous phase was found:

Gelatin - 0.7 g, silicon content 0.34 wt.% = 0.002 g.

Since silicon is the main chemical element in the composition of montmorillonite, it follows from the above data that 90 wt.% Of the initial montmorillonite was concentrated in the shell.

Example 9. The stability study of microcapsules with extinguishing liquids

The stability of the microcapsule samples was evaluated by the loss of extinguishing fluid (weight loss) from the microcapsules when openly stored in a layer with a thickness of 1-2 mm at a temperature of 25 ° C.

Figure 1 presents data on the loss of dibromomethane from microcapsules for two variants of microcapsules:

- microcapsules with a core of dibromomethane and a shell of gelatin (without nanoparticles) - line 1;

- microcapsules with a core of dibromomethane and a shell of gelatin with nanoparticles in the form of nanoscale plates of montmorillonite obtained as described in Example 2, line 2.

Figure 2 presents data on the loss of perfluoroketone from microcapsules for two variants of microcapsules:

- microcapsules with a core of perfluoroketone and a shell of a mixture of polyvinyl alcohol with urea-resorcinol-formaldehyde resin (without nanoparticles) - line 3;

- microcapsules with a core of perfluoroketone and a shell of a mixture of polyvinyl alcohol with urea-resorcinol-formaldehyde resin with nanoparticles in the form of nanoscale plates of montmorillonite obtained as described in Example 1, line 4.

Figure 3 presents data on the loss of perfluoroketone from microcapsules for two variants of microcapsules:

- microcapsules with a core of perfluoroketone and a shell of gelatin (without nanoparticles) - line 5;

- microcapsules with a core of perfluoroketone and a shell of gelatin with nanoparticles in the form of nanoscale plates of montmorillonite obtained as described in Example 3, line 6.

The research data indicate the production of microcapsules containing fire extinguishing liquids (perfluoroketone and dibromomethane) having stable properties necessary for their practical use, only upon receipt of them according to the present invention, with a shell containing nanoparticles of a mineral filler in the form of nanoscale plates.

Example 10. Thermogravimetric analysis (TGA) of microcapsules

Figure 4 presents the TGA data of samples of microcapsules with a core of perfluoroketone (Novec 1230) and a shell of gelatin (without nanoparticles) - line 7, and microcapsules with a core of perfluoroketone (Novec 1230) and a shell of gelatin with nanoparticles in the form of nanoscale plates of montmorillonite obtained as described in Example 3, line 8.

In the process of thermal destruction of microcapsules with a core of fire extinguishing liquids and a shell of gelatin with nanoparticles in the form of nanosized montmorillonite plates obtained according to the present invention, a significant overheating of the liquid is observed until it is released into the surrounding space. TGA data are presented in table 1.

Table 1 No. Name of extinguishing fluid Boiling point of fire extinguishing liquid, ° С The temperature of the destruction of microcapsules, ° C Difference Microcapsule destruction temperature - Exhaust gas boiling point, ° С (average) one Freon 114B2 - tetrafluorodibromoethane 47.3 120 78 2 Perfluoroketon Novec 1230 49.2 90 41 3 Dibromomethane 98 220 125

TGA data also indicate the stabilization of microcapsules, the shell of which contains nanoparticles of a mineral filler in the form of nanosized plates, under thermal exposure and their cooperative explosive destruction at a temperature significantly higher than the boiling point of the extinguishing liquid contained in the core of the microcapsule. It is this type of destruction of microcapsules that is necessary for the active release of a fire extinguisher and extinguishing a fire.

The following Examples 11-18 relate to fire tests of the resulting microcapsules and extinguishing materials.

Example 11. The use of microencapsulated extinguishing agent according to the invention for extinguishing fire

30.0 g of diesel fuel in a flat Petri dish were placed in an experimental box (200 mm × 200 mm × 200 mm) with a lid on top and openings in the lid and side walls. After igniting diesel fuel, the microencapsulated extinguishing agent powder was introduced into the box through a top hole with a hand spray gun for a period of time until the combustion ceased. The time and consumption of the agent were fixed until the cessation of combustion. Under the influence of the flame, the microcapsules were explosively destroyed, and the fire was extinguished. The results obtained are shown in table 2.

table 2 Microcapsules according to the invention Extinguishing liquid in core / shell type The amount of microencapsulated used
fire extinguishing agent, g Extinguishing time, seconds Example 1 Perfluoroketone / A mixture of polyvinyl alcohol with urea-resorcinol-formaldehyde resin and montmorillonite nanoparticles 2.0 3 Example 2 Dibromomethane / Mixture of polyvinyl alcohol with urea-resorcinol-formaldehyde resin and montmorillonite nanoparticles 3.4 6 Example 3 Perfluorketone / Gelatin with Montmorillonite Nanoparticles 2.5 four Example 4 Dibromomethane / Gelatin with montmorillonite nanoparticles 3.8 7

As can be seen from table 2, the amount of spent microencapsulated extinguishing agent with a core of perfluoroketone and the extinguishing time were less than when using microcapsules with dibromomethane.

However, both microencapsulated extinguishing agents are undoubtedly effective. Since they are explosively destroyed at different temperatures, differing by more than 100 ° C, they will find application for different fire extinguishing systems.

The following are examples of studies of various extinguishing structural composite materials according to the invention, made using microencapsulated extinguishing agents according to the invention.

Example 12. Extinguishing material

36.4 g of liquid uncured epoxy was mixed with 3.6 g of polyethylene polyamine as a hardener and 40.0 g of the microencapsulated extinguishing agent according to the invention in the form of a powder containing the microcapsules described in Example 1. The resulting paste was placed in an aluminum tray (200 mm × 200 mm × 200 mm) coated with a silicone release agent and held at 20-25 ° C. for 48 hours to cure.

The obtained extinguishing material plate was placed on the inner wall of the same experimental box used in Example 11, with diesel fuel poured into it and diesel fuel was set on fire. Under the influence of the flame, the microcapsules were destroyed, and the fire was extinguished after 1-2 seconds. The plate was preserved, “craters” the size of a microcapsule formed after their destruction in the surface layer are visible on the surface.

Example 13. Extinguishing coating

The same paste from a mixture of liquid uncured epoxy resin, hardener and a microencapsulated extinguishing agent according to the invention, as in Example 12, was applied to the inner wall of the same experimental box used in Example 11, and kept at 20-25 ° C for 48 hours for curing. The resulting coating reached a thickness of 1-2 mm. Diesel fuel was put into the box and diesel fuel was set on fire. The fire was extinguished 1-2 seconds after its occurrence.

Example 14. Extinguishing material

36 g of liquid silicone rubber was mixed with 3.6 g of a hardener with an organotin catalyst K-18 and 40 g of the microencapsulated extinguishing agent described in Example 2. The composition was cured at a temperature of 20-25 ° C and tested as in Example 13. The fire was extinguished for 1-2 seconds.

Example 15. Fire extinguishing fabric

A mixture of silicone rubber with a hardener with a K-18 organotin catalyst and a microencapsulated extinguishing agent according to the invention described in Example 3 was used to impregnate technical fabric with subsequent curing. The fabric was tested as in Example 12. The fire was extinguished after 1-2 seconds. The fabric remained intact.

Example 16. Extinguishing material

20 g of butyl acrylate latex (polybutyl acrylate content 40% by weight) was mixed with 8 g of microcapsules with perfluoroketone according to the invention, obtained as in Example 3. The mass was applied to the box wall, dried and tested as in Example 13. The fire was extinguished after 3 seconds .

Example 17. Extinguishing foam

24 g of laprol 805 polyester, 56 g of laprol 1002 polyester and 21 g of diethylene glycol were mixed, then, with vigorous stirring, the DAVCO catalyst 0.75 g dissolved in 30 ml of a 50% by weight aqueous solution of potassium acetate, 150 g of polyisocyanate and 50 g microcapsules obtained in Example 4. The expandable mass was placed in a tray, as in Example 12. Foaming and curing of the foam occurred without heating. A sample of polyurethane foam 200 × 200 × 50 mm in size was cut out and tested as in Example 12. The fire was extinguished in 2-3 seconds.

Example 18. Fire extinguishing paint

30 g of water-based paint (based on polyvinyl acetate) was mixed with 20 g of microcapsules obtained as in Example 4. The paint was applied to a sheet of cardboard 150 × 150 × 200 and dried. The tests were carried out as in Example 12. The fire was extinguished in 2-3 seconds. Cardboard is preserved, its edges are slightly burnt.

Thus, in the above examples, it was shown the creation of microencapsulated agents according to the present invention, containing a powder of microcapsules according to the invention, having a polymer shell consisting of a polymeric material with nanoparticles of a mineral filler in the form of nanoscale plates that stably hold a liquid and gasified during heating in the core and provide the mandatory release of the target liquid product from the core at a certain temperature of destruction of the shell in the range not 90-270 ° C.

Since the microencapsulated extinguishing agent according to the present invention is a microcapsule containing a polymer shell consisting of a spatially crosslinked polymer binder and inlaid (filled) with nanoparticles of a mineral filler in the form of nanoscale plates and having an explosion temperature in the range of 90-270 ° C, and the core of the extinguishing liquid, it is adapted for explosive destruction under the influence of heat and flame with the release of a gasified fire extinguisher for fire, while its production and use are not limited to the Montreal Agreement and the Kyoto Protocol.

The microencapsulated extinguishing agent according to the present invention is easily mixed with resins, liquid curable rubbers and other matrices and can be used as a filler in fire extinguishing composite materials, for example, in the form of pastes, plates, films, coatings, foams, technical fabrics, shapes and other products .

It will be understood by those skilled in the art of extinguishing that using the microcapsule manufacturing method of the invention, microencapsulated extinguishing agents capable of ejecting the target liquid product into the external environment at a certain temperature can be provided, for example, by selecting a specific fire extinguishing liquid and ensuring stability by introducing nanofillers into the composition of the shell.

Such extinguishing agents can be used in various fields of industry and in various fire extinguishing systems for effective automatic inertia-free fire prevention both in the form of microcapsule powder and as a part of fire-extinguishing composite materials - coatings, films, cambrices, fire-extinguishing protective fabrics and others.

Claims (31)

1. A microencapsulated extinguishing agent containing microcapsules having a core of a spatially crosslinked polymeric material placed inside a spherical polymer shell, a core of fire-extinguishing liquid, characterized in that the polymer shell contains nanoparticles of a mineral filler in the form of plates having a thickness of 1-5 nm, and has the ability of explosive destruction in the temperature range of 90-270 ° C. 2. The agent according to claim 1, characterized in that the polymeric material of the shell is a complex of polyvinyl alcohol and urea-resorcinol-formaldehyde resin. 3. The agent according to claim 1, characterized in that the polymer material of the shell is crosslinked gelatin. 4. The agent according to claim 1, characterized in that the nanoparticles of the mineral filler are made in the form of nanoscale plates of natural montmorillonite aluminosilicate or its analogues in an exfoliated state. 5. The agent according to claim 1, characterized in that the shell of the microcapsule contains these nanoparticles of mineral filler in an amount of 1-5% by weight of the shell. 6. The agent according to claim 1, characterized in that the microcapsule has an outer diameter in the range of 50-400 microns. 7. The agent according to claim 1, characterized in that the core of the microcapsule contains extinguishing fluid in an amount of 75-95% by weight of the microcapsule. 8. The agent according to claim 1, characterized in that the core contains perfluoroethyl perfluoroisopropyl ketone. 9. The agent according to claim 1, characterized in that the core contains dibromomethane. 10. The agent according to claim 1, characterized in that the core contains a bromine-containing or fluorobromine-containing fire extinguishing liquid. 11. The agent according to claim 1, characterized in that the core contains a mixture of extinguishing liquids selected from the group including: perfluoroethyl-perfluoroisopropyl-ketone, dibromomethane, brominated hydrocarbons, fluorinated brominated hydrocarbons in a liquid state. 12. A method of producing a microencapsulated extinguishing agent containing microcapsules having a core of a spatially crosslinked polymer inside a spherical polymer shell, a core of fire-extinguishing liquid, in which the polymer shell contains nanoparticles of a mineral filler in the form of plates having a thickness of 1-5 nm, and has the ability of explosive destruction in the temperature range of 90-270 ° C, in which they carry out:
a) the preparation of a suspension containing nanoparticles of exfoliated mineral filler by mixing the powdered mineral filler with distilled water and treating the suspension with ultrasound until the reaction mixture becomes clear, preserving slight opalescence;
b) preparing an aqueous solution of the starting polymer shell material and mixing it with the suspension obtained in stage a);
c) emulsification of the extinguishing fluid to be placed in the core of the microcapsule in an aqueous solution of a polymeric shell material containing nanoparticles of a mineral filler obtained in stage b);
d) the phased formation of the emulsion obtained in stage c) on the droplets, by the coacervation method, including drop separation of phases, sorption of the coacervate droplets enriched with montmorillonite nanoplates on the surface of the droplets of the extinguishing liquid emulsion and their coalescence to obtain liquid shells;
d) curing the shells with the formation of microcapsules, washing them with water, filtering and drying. 13. The method according to p. 12, characterized in that as the polymer material of the shell using a complex of polyvinyl alcohol and urea-resorcinol-formaldehyde resin. 14. The method according to p. 13, characterized in that at the stage d) the formation of the shell is carried out by adding to the emulsion of the extinguishing liquid in the solution of polyvinyl alcohol obtained in stage c), a mixture of an aqueous solution of urea with resorcinol and formaldehyde and lowering the pH of the medium to 1 , 2, and at stage d) the curing of the shells is carried out by increasing the temperature to 45 ° C and holding at the indicated temperature for 3.5 hours 15. The method according to p. 12, characterized in that the cross-linked gelatin is used as the polymer material of the shell. 16. The method according to p. 15, characterized in that at the stage d) the formation of the shell is carried out by adding an extinguishing liquid to the emulsion in the gelatin solution obtained in stage c), an aqueous solution of sodium polyphosphate, lowering the pH to 4.0-4, 5, subsequent cooling of the emulsion to 5-10 ° C, and at the stage d) curing of the shells is carried out by adding glutaraldehyde, holding at the indicated temperature for at least 1.0 h, raising the temperature to 20-25 ° C, lowering the pH of the mixture up to 1.0-2.0, addition of resorcinol and formaldehyde, exposure ex and a temperature of 30-35 ° C for 30-40 minutes. 17. The method according to clause 15, wherein in step g) the formation of the shell is carried out by adding an extinguishing liquid to the emulsion in the gelatin solution obtained in step c), an aqueous solution of sodium polyphosphate, lowering the pH to 4.0-4, 5, subsequent cooling of the emulsion to 5-10 ° C, and at the stage d) curing of the shells is carried out by adding glutaraldehyde and exposure at the indicated temperature for at least 5.0-6.0 hours 18. The method according to p. 12, characterized in that the use of nanoparticles of mineral filler made in the form of nanoscale plates of natural aluminosilicate montmorillonite or its analogues in an exfoliated state. 19. The method according to p. 12, characterized in that receive microcapsules having an outer diameter in the range of 50-400 microns. 20. The method according to p. 12, characterized in that microcapsules are obtained in which the core contains extinguishing liquid in an amount of 75-95% by weight of the microcapsule. 21. The method according to p. 12, characterized in that the quality of the extinguishing fluid is perfluoroethyl perfluoroisopropyl ketone. 22. The method according to p. 12, characterized in that dibromomethane is used as the extinguishing liquid. 23. The method according to p. 12, characterized in that as a fire extinguishing liquid using bromine-containing or fluorine-containing fire-extinguishing liquid. 24. The method according to p. 12, characterized in that the mixture of fire extinguishing liquids selected from the group consisting of: perfluoroethyl perfluoroisopropyl ketone, dibromomethane, brominated hydrocarbons, fluorinated brominated hydrocarbons in a liquid state is used as an extinguishing liquid. 25. An extinguishing composite material containing a cured resin or cured rubber, including a microencapsulated extinguishing agent dispersed therein, made according to any one of claims 1 to 11. 26. The material according to claim 25. characterized in that it is made in the form of foam. 27. The material according A.25, characterized in that it is made in the form of a curable paste. 28. The material according A.25, characterized in that it is made in the form of a structural element. 29. The material according A.25, characterized in that it is made in the form of a film. 30. The material according A.25, characterized in that it is made in the form of a fire extinguishing fabric, impregnated or coated with a curable paste containing resin or rubber, including a microencapsulated extinguishing agent dispersed in them, made according to any one of claims 1 to 11. 31. An extinguishing paint coating containing a microencapsulated extinguishing agent dispersed in it, made according to any one of claims 1 to 11.

Images