RU2786728C1 - Thermochromic nanocapsulated material, the method for its preparation and the product containing such material - Google Patents

Abstract

FIELD: fire protection.

SUBSTANCE: group of inventions relates to the field of fire safety, namely to modern means of control and prevention of fires at an early stage by constant local, point monitoring of temperatures or overheating of electrical wiring, contact groups, terminals, equipment and various objects through the use of chemical indicators of a combined principle of action that change their color and emit odor when exposed to temperature. Thermochromic nanocapsule material used to generate a signal about local overheating of electrical equipment by simultaneously releasing an odorant and changing the color of the material with increasing temperature includes nanocapsules containing a core located inside a shell of polymer material with an odorant. The material consists of nanocapsules distributed in a polymer binder with a thermochromic substance core located in a multilayer modified polymer shell containing a layer with an odorant and a protective flame retardant layer, with the following component ratio, wt. %: a thermochromic substance core 84-88, a polymer shell 5-7, a plasticizer 3-5, an odorant layer 2-3, a protective fire retardant layer 2-3. Nanocapsules have an activation temperature range of 50-250°C. The outer diameter of the nanocapsules is 40-60 microns. The average thickness of the odorant layer is 2-3 microns. The average thickness of the protective fire retardant layer is 2-3 mcm. To obtain a thermochromic nanocapsule material, the thermochromic substance is crushed, sieved and separated to a homogeneous fine fraction of 30-50 mcm. A mixture of polymer and plasticizer is prepared, divided into parts, a mixture with odorant and a mixture with nanocomposites are prepared, which are then fed into separate tanks of the dosing unit. A polymer hardener is loaded into a separate tank of the dosing unit. The resulting thermochromic substance is electrified with static electricity and loaded into the layer deposition chamber. They are sprayed with dry compressed air and a mixture of polymer and odorant is supplied. At the end of the spraying cycle, the raw material coated with the formed layer of the uncured shell is deposited in the reaction chamber and the hardener is sprayed and the polymer is cured. The resulting raw materials are reversed from the reaction chamber to the layer deposition chamber and a mixture of the said polymer and nanocomposite is sprayed. At the end of the spraying cycle, the raw material coated with the next layer of the uncured shell is deposited from the spray chamber of the layer into the reaction chamber. Spraying of the hardener and curing of the polymer are carried out. At the end of the cycles of spraying the layers and curing the shells, the finished material is obtained, which is unloaded into a technological container, sorted and packed into transport containers. The thermochromic nanocapsule product is made in the form of a structural product and contains the thermochromic nanocapsule material described above.

EFFECT: increase in the flowability of the material, an increase in the long-term storage time while maintaining the original properties, an increase in uniformity, chemical resistance and uniformity of mixing in polymer compositions, resistance to aggressive media/solvents and stabilization of the activation temperature is provided.

10 cl, 8 dwg, 5 tbl

Description

Technical field

SUBSTANCE: group of inventions relates to the field of fire safety, namely, to modern means of controlling and preventing the occurrence of fires at an early stage by constant local (point) monitoring of temperatures or overheating of electrical wiring, contact groups, terminals, equipment and various objects through the use of chemical indicators of the combined principle actions that change their color and emit odor (odorants) when exposed to temperature, and is a thermochromic nanoencapsulated material (TNCM) in the form of nanocapsules in a multilayer modified polymer shell, a method for producing such a material and products from it, for example, thermal indicators, stackers, stickers, plates, installations, threads, cords, ribbons, fabrics, capes, etc.

Prior Art

Composite fire-extinguishing materials are known from patent-information sources, designed to eliminate a fire that has arisen.

Known patent RU 2403934, A62D 1/00, publ. 11/20/2010. The fire-extinguishing composition contains microcapsules with a core of fire-extinguishing agent, which is halocarbons, surrounded by a shell of polymeric material, distributed in a polymeric binder. The sheath material is polyurea and/or polyurethane based on polyisocyanate prepolymer. The microcapsules have sizes in the range of 2.0-100.0 µm.

Known patent RU 2469761, A62D 1/00, B82B 3/00, publ. 12/20/2012. The microencapsulated fire extinguishing agent contains microcapsules having a core of fire extinguishing liquid placed inside a spherical polymer shell made of a cured spatially crosslinked polymer material and containing mineral filler nanoparticles in the form of plates having a thickness of 1-5 nm. The specified agent has the ability of explosive destruction in the temperature range of 90-230°C. Microcapsules can have an outer diameter in the range of 50-400 μm and a core of fire-extinguishing liquid, by weight comprising 75-95% of the mass of the microcapsule, which is used as a bromine-containing or fluorine-bromine-containing fire extinguishing liquid, perfluoroethyl-perfluoroisopropyl-ketone and/or dibromomethane, or a mixture extinguishing liquids selected from the group including: perfluoroethyl-perfluoroisopropyl-ketone, dibromomethane, bromine-substituted hydrocarbons, fluorobromine-substituted hydrocarbons in liquid state. A spherical polymer shell can be made, for example, from a complex of polyvinyl alcohol and urea-resorcinol-formaldehyde resin or cross-linked gelatin and may contain a mineral filler in an amount of 1-5% by weight of the shell in the form of nano-sized plates of natural montmorillonite aluminosilicate or its analogues in exfoliated condition. The mentioned microcapsules can be used for fire extinguishing as part of a fire-extinguishing composite material (RU 2469761, A62D 1/00, V82V 3/00, publ. 20.12.2012).

A composite material is known, (patent RU 2686714, A62D 1/00, publ. 04/30/2019), "Microgranular fire extinguishing agent of combined action, method for its preparation, fire extinguishing product containing such an agent." The invention describes a method in which microcapsules are mixed with oxidizing agents (barium nitrate or ammonium nitrate), a cementing agent (starch, dextrin), a plasticizer, and microgranules are formed. The release of active oxygen during the thermal decomposition of nitrates provokes the combustion of the cementing agent, as a result of which the opening of microcapsules and the pulsed release of fire extinguishing agents into the protected volume occur, and the process occurs according to the chain principle.

The composite materials described above belong to fire-extinguishing substances and are intended only for the elimination of a fire that has arisen, and not for its prevention, while the most effective way to fight a fire is its early recognition and detection.

Today, in the field of fire safety, one of the important tasks is the creation of means of control and prevention of a fire situation. The most effective method of fighting fires is to recognize pre-fire situations at an early stage by detecting places of overheating of electrical wiring, contact groups and equipment at objects with varying degrees of tightness and accessibility, such as sockets, switches, circuit breakers, junction boxes, lamps, switchboards, electrical cabinets, control panels, server racks, battery compartments, fuel tanks, engine compartments, cable channels, complete switchgears (KRU) and other objects with a possible fire hazard (hereinafter referred to as objects).

The development of a specialized signaling material and products based on it, designed to prevent the possibility of a fire, is an urgent and promising task.

It is known that thermochromic materials are one of the easiest to use and promising means of not only recording, but also measuring the duration of exposure to maximum allowable temperatures. Thermochromic materials are materials that have the ability to dramatically change their color or become transparent at a certain temperature, called the transition temperature. According to the principle of operation, thermochromic materials are divided into four types: thermochemical, melting, liquid crystal and luminescent. According to their physical and chemical properties, thermal indicators are divided into reversible (reversible), irreversible (non-reversible) and quasi-reversible (reversible under chemical or temperature exposure).

It became known from the scientific and technical literature that, based on the analysis of fire statistics, a conclusion was made about the possibility of using thermochromic paints as indicators of the development of fire hazardous operating modes. The introduction of thermochromic dyes into electrical wiring insulation makes it possible to visualize the development of emergency operation modes. With the help of thermochromic stickers pasted on the cases of transformers and electric motors, the possibilities of this signaling material, designed to warn about the possibility of a fire, were revealed. Thermochromic inks can be applied using offset printing, such as lithography, concentrate conversion (masterbatch), flexography, such as block printing, etc.

To protect thermochromic paints, a kind of protective film is used, which is very sensitive to the environment. A well-known technology is the protection of thermochromic paints using microcapsules ranging in size from a few to hundreds of microns in order to seal or close the paint material (RU 2537610 C09K 19/54, publ. 01/10/2015 under the name "Liquid crystal microcapsule").

The closest analogue of the invention is a polymer composite material used to generate a signal about local overheating of electrical equipment, patent RU 2622947, C09K 21/14, A62D 1/00, publ. 06/21/2017. Described is a polymer composite material filled with an odorant, which is sulfur dioxide, lower mercaptans, dialkyl sulfides, dialkyl disulfides or mixtures thereof, having an explosive destruction temperature in the range of 80-200°C, moreover, the polymer composite material filled with an odorant is: a material containing microcapsules with a core of an odorant surrounded by a shell of a polymeric material, distributed in a polymeric binder; or a material containing particles of a cross-linked polymer swollen in an odorant solution, enclosed in a polymer matrix; or a material containing sorbent particles with an odorant adsorbed on them, enclosed in a polymer matrix; or a material containing particles of a porous polymer with closed pores or channels filled with an odorant or an odorant solution, enclosed in a polymer matrix.

The mentioned polymer composite material can be used for early detection of pre-fire situations, when the heating of wires or electrical contacts exceeds the permissible operating parameters (more than 100°C), but does not yet reach the level at which thermal destruction of materials capable of ignition occurs (more than 250°C). С) (RU 2596954, G08B 17/00, published on 09/10/2016).

The main disadvantages of industrially used thermochromic materials are:

- caking and the need for fine grinding and sifting from large inclusions before direct use, which complicates and complicates the technological application in the manufacture of final products;

- chemical interaction with most polymeric materials, which leads to marriage in the production of finished products.

- combustibility, which is a significant limitation before use as part of fire-fighting products.

Disclosure of invention

The aim of the invention is to create a new type of thermochromic nanoencapsulated material with a combined principle of operation that can increase the likelihood of visual and remote detection of a pre-fire situation at an early stage of an emergency.

TMCM is used to generate a signal about local overheating of electrical equipment, by simultaneously releasing an odorant and changing the color of the material with increasing temperature.

The technical result of the invention is to increase the flowability of the material, increase the time of long-term storage while maintaining the original properties, increase the uniformity, chemical resistance and uniformity of mixing in the composition of polymer compositions, resistance to aggressive media/solvents and stabilization of the activation temperature.

The set tasks are solved in the following way.

Thermochromic nanoencapsulated material is nanocapsules distributed in a polymeric binder, with a core of a thermochromic substance, located in a multilayer modified polymer shell containing a layer with an odorant and a protective antipyretic layer, in the following ratio of components, wt. %: thermochromic substance core 80-90, polymer shell 5-7, plasticizer 2-5, odorant layer 1-3, protective flame retardant layer 1-3, while nanocapsules are activated in the temperature range of 50-250°C, outer diameter nanocapsules is 40-60 microns, the average thickness of the layer with the odorant is 1-3 microns, the average thickness of the protective flame retardant layer is 1-3 microns.

It is allowed to use as a thermochromic substance substances that have a color transition in the temperature range from 50 ° C to 250 ° C, such as complex compounds: [Fe (MoO ₄ ) ₆ ] (NH ₄ ) ₃ * 7H ₂ O with a color transition at 80 °С, CoSO ₄ *2[(CH ₂ ) ₆ N ₄ ]*9H ₂ O with a color transition at 110°С, PO ₄ [Co(NH ₃ ) ₆ ] with a color transition at 230°С.

In addition, polymers are used as a polymer shell: cyanoacrylate, sodium alginate, epoxy resins, polyurethane, synthetic rubbers, or mixtures thereof.

In addition, glycerol, dioctyl phthalate (DOP), dibutyl phthalate (DBP) or mixtures thereof are used as a plasticizer for the polymer shell.

In addition, ethyl mercaptan, tetrahydrothiophene, dimethyl sulfide are used as an odorant.

In addition, polymer-layered silicates (nanocomposites) are used as a flame retardant shell: pyrophyllite - Al2[Si4O10] (OH) 2 and / or montmorillonite (MMT) - Nax (Al4.x, Mgx) 2 Si802o (OH) 4 and / or orthosilicate - Na2SigOi79(OH)2.

The method for obtaining a thermochromic nanoencapsulated material by diffusion spraying of an uncured modified polymer shell in an electrostatic field with subsequent curing includes the following stages: - preparing a mixture of a polymer with a plasticizer, and dividing it into parts, preparing a mixture with an odorant, and a mixture with nanocomposites, which are then fed into separate tanks of the dosing unit, - the polymer hardener is loaded into a separate tank of the dosing unit, - the thermochromic substance is loaded into the layer spraying chamber, sprayed with dry compressed air and the mixture of polymer and odorant is fed, - at the end of the spraying cycle, the raw material coated with the formed layer of uncured shell is deposited in the reaction chamber and the hardener is sprayed and the polymer is cured, - the obtained raw material is transferred by reverse from the reaction chamber to the layer deposition chamber and the mixture of the mentioned polymer and the nanocomposite is sprayed, - the raw material coated with the next layer of uncured shell is from the chamber layer spraying is deposited into the reaction chamber, and the hardener is sprayed and the polymer is cured, - at the end of the layers spraying and shell curing cycles, the finished material is obtained, which is unloaded into a technological container, sorted and packed in a shipping container.

The thermochromic nanoencapsulated product is made in the form of a structural product and contains a thermochromic nanoencapsulated material placed in a polymer shell. Structurally, the product can be made in the form of a thermal indication stacker or a plate, or a thread.

The distinctive features of the invention showed in the claimed set of essential features new properties that do not explicitly follow from the prior art in this field and are not obvious to a specialist.

An identical set of features was not found in the patent and scientific and technical literature. It should be noted that when creating the present invention, the possibilities of improving the performance characteristics of thermochromic nanocapsules of the combined principle of action have not been exhausted.

Implementation of the invention

The present invention is illustrated by the drawings shown in Fig. 1-8. In FIG. 1 shows a section of a nanocapsule in a polymer shell, in Fig. 2 shows the design of the device for mass production of nanocapsules of FIG. 1, Fig. 3 is a section of the thermal indication stacker, Fig. 4 is a device for the production of stackers of Fig. 3, in Fig. 5 is a section of the design of thermal indication fire extinguishing plates, in Fig. 6 shows the device for producing the plates of FIG. 5 in FIG. 7 is a section of the design of heat-indicating threads, in Fig. 8 shows a device for the production of threads of FIG. 7.

In FIG. 1 shows the design of a nanocapsule in a polymer shell, the core of which consists of a thermochromic material 1, placed in a polymer shell containing a layer with an odorant 2 and a protective flame retardant layer 3. The nanocapsule contains a core of thermochromic material - 80-90%, polymer - 5-7%, plasticizer - 2-5%, odorant - 1-3% and flame retardant - 1-3%. Thermochromic substances having a color transition in the temperature range from 50°С to 250°С (complex compounds: [Fe(MoO4)6](NH4)3*7H2O, CoSO4*2[ (CH2)6N4]*9H2O, PO4[Co(NH3)6] and other substances), which corresponds to:

- the maximum operating temperature, according to the operational documentation, for most types of electrical equipment and devices (from 50 ° C to 90 ° C);

- activation temperature of autonomous fire extinguishing devices using thermally activated microencapsulated gas-emitting fire extinguishing agents ("Thermo OTV") according to GOST P 56459-2015 (from 110°C to 130°C);

- the starting point of decomposition, smoke emission and the likelihood of ignition of most components and materials used in the manufacture of wires and electrical equipment (from 150 ° C to 250 ° C). The list of thermochromic substances used can be extended.

As a polymer for the shell, cyanoacrylate, sodium alginate, epoxy resins, polyurethane, synthetic rubbers, etc. are used. Combined types of shells or dissimilar coatings can be used (to achieve the specified performance characteristics). The list of polymers in the present invention is not exhausted.

Glycerin, dioctyl phthalate (DOP), dibutyl phthalate (DBP), etc. are used as a plasticizer for the polymer shell. It is possible to use combined types of plasticizers to give the polymer shell the desired properties in terms of adhesion, mechanical and thermal stability, resistance to temperature extremes, as well as the speed and quantity release of an odorant. The list of plasticizers in the present invention is not exhausted.

Ethyl mercaptan, tetrahydrothiophene, dimethyl sulfide, etc. can be used as an odorant for influencing the human senses in order to signal the activation of products. It is allowed to add additional substances that release gases when heated and liquefied gases for use in electronic gas analyzers and detectors. The list of odorants in the present invention is not exhausted. The thickness of the layer with the odorant is 1-3 microns.

As a protective flame retardant layer, polymer-layered silicates (nanocomposites) can be used: pyrophyllite - Al2[Si4O10] (OH) 2 and / or montmorillonite (MMT) - Nax (Al4.x, Mgx) 2 Si802o (OH) 4 and / or orthosilicate - Na2SigOi79(OH)2. The list of flame retardants in the present invention is not exhausted. The average thickness of the protective flame retardant layer is 1-3 microns.

The average value of the outer diameter of the nanocapsules is 40-60 microns. The activation temperature of the material is in the range from 50°C to 250°C.

The use of TMCM will simultaneously solve the problems of improving flowability, long-term storage without changing chemical properties, homogeneity and uniformity of mixing in the composition of polymer compositions, imparting properties to the finished product, coating or polymer, low flammability or not maintaining combustion, resistance to aggressive media and solvents for expansion spheres and technologies of application.

Nanocapsules can be used as:

- filler in the manufacture of paints and varnishes;

- additives in various polymeric compositions to give finished products the properties of color indication and odor release during thermal exposure;

- filler in the manufacture of braided wires and plastic products (boxes, junction boxes, socket boxes, connectors, etc.) using cold casting or casting technology, which have the properties of indication on the outer surface and odor release in the presence of thermal overheating or fires in the internal volume.

In FIG. Figure 2 shows a device for the serial production of nanocapsules, consisting of a layer spraying chamber 4, a reaction chamber 5 and a dosing unit 6. Nanoencapsulation of a thermochromic material into a multilayer modified polymer shell is carried out in a two-chamber vacuum reactor by diffusion spraying of an uncured modified polymer shell in an electrostatic field, followed by curing in the reaction chamber. The rotary-reversing mechanism of the reactor makes it possible to change the positions of the chambers relative to each other in order to quickly move the nanoencapsulated material from one chamber to another by the method of deposition by a flow of dry compressed air.

A feature of the reactor design is the symmetry with respect to the rotary mechanism of automatically sealing flange connectors, which make it possible to disconnect and connect the chambers to the dosing unit when changing positions. As well as the design of the dosing unit, consisting of several tanks, which allows, in a given algorithm, to sequentially and independently inject up to 10 types of bulk, liquid and gaseous materials into the reactor to create layers for various purposes, physical and chemical activity.

To maintain a stable electrostatic field, the vessel and the main structural components of the reactor are made of plastic by injection molding. To maintain the set temperature in the chambers and the dosing unit, the reactor is equipped with a bulk temperature stabilization loop that allows you to flexibly adjust the temperature level, as well as work with materials heated or cooled to negative temperatures.

The advantage of the production technology is the possibility of continuous layer-by-layer deposition of a given number of polymer layers of different composition to create a multilayer shell with the required performance characteristics.

The production of nanocapsules includes:

- grinding with a ball mill raw thermochromic material,

- screening and separation of the crushed thermochromic material to a homogeneous fine fraction of 30-50 microns,

- mixing polymer with plasticizer,

- mixing a given amount of the prepared polymer with odorants (Mix 1) and filling it into the first tank of the dosing unit 6,

- mixing a given amount of the prepared polymer with nanocomposites (Mix 2) and filling it into the second tank of the dosing unit 6,

- filling the third tank of the dosing unit 6 with a given amount of polymer hardener,

- loading and spraying with dry compressed air of electrostatically charged particles of crushed thermochromic material in chamber 4,

- spraying in automatic mode mixture 1 using a rotating vane volumetric diffusion nozzle in chamber 4,

- at the end of the spray cycle in the reactor, the longitudinal bulkhead between the chambers is depressurized; the material covered with the first layer of uncured shell is deposited from the chamber 4 with the help of dry compressed air into the reaction chamber 5, where the hardener is sprayed by means of a rotating vane volumetric diffusion nozzle and the polymer is cured,

- the thermochromic material coated with the first layer is transferred from chamber 5 back to chamber 4 by reversing the reactor, depressurization of the longitudinal bulkhead and a stream of dry compressed air, where mixtures 2 are sprayed in automatic mode using a rotating vane volumetric diffusion nozzle,

- at the end of the spraying cycle in the reactor, the longitudinal bulkhead between the chambers is depressurized and the material covered with the next layer of uncured shell from the chamber 4 is deposited with dry compressed air into the reaction chamber 5, where the hardener is sprayed using a rotating vane volumetric diffusion nozzle and the polymer is cured,

- at the end of the required number of cycles of spraying the layers and curing the shells, the finished nanocapsules from the chamber 5 are unloaded by a stream of dry compressed air through the transport socket into a technological container, sorted and packed into a transport container.

Examples of specific implementation of the invention

Example #1.

The production cycle of nanocapsules in a 2-layer shell with a filler of [Fe(MoO4)6](NH4)3*7H2O, a polymer shell of cyanoacrylate, a plasticizer of dioctyl phthalate (DOP), an odorant of ethyl mercaptan, and an antipyretic additive of pyrophyllite:

1. [Fe(MoO4)6](NH4)3*7H2O in the amount of 40.0-60.0 kg at 100-120 rpm. within 24 hours, crushed in a ball mill to a homogeneous dusty state.

2. 25.0-30.0 kg of filler material with a diameter of 30-50 microns is screened out from the crushed filler on a sealed fractional vibrating screen.

3. Cyanoacrylate in the amount of 2.0-4.0 kg in a vacuum planetary mixer at 80-100 rpm is mixed with 5-20% dioctyl phthalate (DOP).

4. The first part of the plasticized polymer in the amount of 1.0-2.0 kg in a vacuum glider mixer at a mode of 50-60 rpm is mixed with 3-5% ethyl mercaptan (Mix 1) and poured into sealed tank No. 01 of the dosing unit 6.

5. The second part of the plasticized polymer in the amount of 1.0-2.0 kg in a vacuum glider mixer at a mode of 50-60 rpm is mixed with 8-10% pyrophyllite (Mix 2) and poured into a sealed tank No. 02 of the dosing unit 6.

6. 1.5-3.0 kg of hardener: distilled water is poured into the sealed tank No. 03 of the dosing unit 6.

7. The prepared filler is electrified with a positively charged potential in an electrocyclone installation and is fed through the socket of the dosing installation 6 into the layer 4 deposition chamber.

8. Mix 1 in automatic mode with a frequency of 0.03-0.05 kg per minute using a rotating vane volumetric diffusion nozzle pulsed with a frequency of 20-30 microdoses / min. sprayed in chamber 4.

9. At the end of the spraying cycle of Mixture 1, the internal longitudinal bulkhead of the reactor opens and the filler covered with the first layer of the shell is deposited with a stream of dry compressed air into chamber 5, where compressed air saturated with a hardener is sprayed automatically at a frequency of 0.02-0.04 kg per minute .

10. At the end of the curing cycle, the filler reinforced with the first layer is moved by turning the reactor by 90 ° and a stream of dry compressed air into chamber 4, where Mixture 2 is sprayed automatically at a frequency of 0.03-0.05 kg per minute.

11. At the end of the spraying cycle of Mixture 2, the longitudinal bulkhead of the reactor opens and the filler coated with the second layer of the shell is deposited in chamber 5, where compressed air saturated with hardener is sprayed automatically at a frequency of 0.02-0.04 kg per minute.

12. At the end of a predetermined number of cycles of layer spraying and shell curing, finished TNCM are unloaded into a technological container by a stream of dry compressed air through a socket, sorted and packed into a shipping container.

Example #2.

The production cycle of TNCM in a 3-layer shell with a filler of CoSO4*2[(CH2)6N4]*9H2O, a polymer shell of sodium alginate, a plasticizer of glycerin, an odorant of tetrahydrothiophene and an antipyretic additive of montmorillonite:

1. CoSO ₄ *2[(CH ₂ ) ₆ N ₄ ]*9H ₂ O in the amount of 40.0-60.0 kg at 100-120 rpm for 24 hours is crushed in a ball mill to a homogeneous dusty state.

2. 25.0-30.0 kg of filler material with a diameter of 50-70 microns is screened out from the crushed filler on a sealed fractional vibrating screen.

3. Sodium alginate in an amount of 0.2-0.4 kg in a vacuum planetary mixer is dissolved in 2.0-4.0 kg of distilled water and at a mode of 80-100 rpm. mixed with 5-20% glycerin.

4. The first part of the plasticized polymer in the amount of 1.0-2.0 kg in a vacuum glider mixer at a mode of 50-60 rpm is mixed with 3-5% tetrahydrothiophene (Mixture 1) and poured into a sealed tank of the dosing unit 6.

5. The second part of the plasticized polymer in the amount of 1.0-2.0 kg in a vacuum glider mixer at a mode of 50-60 rpm is mixed with 15-20% of montmorillonite (Mix 2) and poured into a sealed tank of the dosing unit 6.

6. A hardener is poured into the sealed tank of the dosing unit 6 - a solution of 0.3-0.5 kg of calcium lactate in 3.0-5.0 kg in distilled water.

7. The prepared filler is electrified with a positively charged potential in an electrocyclone installation and is fed through the socket of the dosing installation 6 into the layer deposition chamber.

8. Mix 1 in automatic mode with a frequency of 0.03-0.05 kg per minute using a rotating volumetric diffusion nozzle pulsed at a frequency of 20-30 microdoses / min. sprayed in chamber 4.

9. At the end of the spraying cycle of Mixture 1, the longitudinal bulkhead of the reactor opens and the filler coated with the first layer of the shell is deposited in chamber 5, where compressed air saturated with hardener is sprayed automatically at a frequency of 0.02-0.04 kg per minute.

10. At the end of the curing cycle, the filler reinforced with the first layer is moved by turning the reactor by 90 ° to chamber 4, where Mixture 2 is sprayed automatically at a frequency of 0.03-0.05 kg per minute.

11. At the end of the spray cycle of Mixture 2, the longitudinal bulkhead of the reactor opens and the filler coated with the first layer of the shell is deposited in chamber 5, where compressed air saturated with hardener is sprayed automatically at a frequency of 0.02-0.04 kg per minute.

12. At the end of a predetermined number of cycles of layer spraying and shell curing, finished TNCM are unloaded into a technological container by a stream of dry compressed air through a socket, sorted and packed into a shipping container.

Example #3.

Production cycle of TNKM in a 4-layer casing with a filler of PO4[Co(NH3)6], a polymer casing of a modified low-viscosity epoxy resin, a dibutyl phthalate (DBP) plasticizer, a dimethyl sulfide odorant, and an orthosilicate antipyretic additive:

1. PO ₄ [Co(NH ₃ ) ₆ ] in the amount of 40.0-60.0 kg at 100-120 rpm. within 24 hours, crushed in a ball mill to a homogeneous dusty state.

2. 25.0-30.0 kg of filler material with a diameter of 50-70 microns is screened out from the crushed filler on a sealed fractional vibrating screen.

3. Modified low-viscosity epoxy resin in the amount of 2.0-4.0 kg in a vacuum planetary mixer at 80-100 rpm is mixed with 5-20% dibutyl phthalate (DBP).

4. The first part of the plasticized polymer in the amount of 1.0-2.0 kg in a vacuum glider mixer at a mode of 50-60 rpm is mixed with 3-5% dimethyl sulfide (Mixture 1) and poured into a sealed tank of the dosing unit 6.

5. The second part of the plasticized polymer in the amount of 1.0-2.0 kg in a vacuum glider mixer at a mode of 50-60 rpm is mixed with 8-10% orthosilicate (Mixture 2) and poured into a sealed tank of the dosing unit 6.

6. 1.5-3.0 kg of hardener: triethylenetetramine (TETA) is poured into the sealed tank of the dosing unit 6.

7. The prepared filler is electrified with a positively charged potential in an electrocyclone installation and is fed through the socket of the dosing installation 6 into the layer 4 deposition chamber.

8. Mix 1 in automatic mode with a frequency of 0.03-0.05 kg per minute using a rotating volumetric diffusion nozzle pulsed at a frequency of 20-30 microdoses / min. sprayed in chamber 4.

9. At the end of the spraying cycle of Mixture 1, the longitudinal bulkhead of the reactor opens and the filler coated with the first layer of the shell is deposited in chamber 5, where compressed air saturated with hardener is sprayed automatically at a frequency of 0.02-0.04 kg per minute.

10. At the end of the curing cycle, the filler reinforced with the first layer is moved by turning the reactor by 90 ° to chamber 4, where Mixture 2 is sprayed automatically at a frequency of 0.03-0.05 kg per minute.

11. At the end of the spray cycle of Mixture 2, the longitudinal bulkhead of the reactor opens and the filler coated with the first layer of the shell is deposited in chamber 5, where compressed air saturated with hardener is sprayed automatically at a frequency of 0.02-0.04 kg per minute.

12. At the end of a predetermined number of cycles of layer spraying and shell curing, finished TNCM are unloaded into a technological container by a stream of dry compressed air through a socket, sorted and packed into a shipping container.

Methodology for conducting laboratory tests

For quality control and testing, samples with a color transition temperature (activation) of 80°C, 120°C and 250°C (hereinafter Type 1, Type 2 and Type 3) are taken from a batch of finished nanocapsules by random sampling, 100 g of each type. Samples are weighed, visually evaluated using an electron microscope for quality and uniformity of appearance, sieved into fractions using a laboratory sieve, thermo-gravimetric analysis is carried out on a derivatorgraph, and the color transition temperature and mass change after testing are also recorded.

Temperature test procedure

To conduct temperature tests of TNKM to register the temperature of the color transition from metal, mock-ups of electric boxes with a volume of 5, 10 and 15 liters are prepared. During the tests, an electric heating element with a heating controller, an electronic thermometer, a pyrometer, a gas analyzer and a video camera are installed inside the boxes. In order to ensure the inflow of air at room temperature, two holes with a diameter of at least 3 cm are made in the bottom of the box. To ensure natural / convection outflow of heated air, in order to maintain a stable internal temperature, a hole with a diameter of at least 5 cm is made in the upper part of the box. further Activation 1) is fixed using a gas analyzer, and the color transition (hereinafter Activation 2) is fixed using specialized software for analyzing the video stream.

Findings and Conclusions

A batch of nanocapsules is considered to have successfully passed laboratory and temperature tests if the test results match the results indicated in tables No. 1 and 2.

Examples of using

Based on the developed TNKM, it is possible to produce a wide range of modern (innovative) means of monitoring, automatic detection and prevention of a fire: thermal indicators, stackers, stickers, plates, installations, threads, cords, tapes, fabrics, capes, etc.

Sample No. 1 - Thermal indication stickers

Monitoring of overheating of current-carrying wires and equipment using permanently installed means and devices is the most promising preventive measure for detecting defects in contact groups, as well as registering hidden defects in equipment, short circuits and overloading of electrical wiring. Thermal indication stickers belong to a new promising generation of pre-fire detectors that provide the detection of the prerequisites for a fire at the earliest stages of development. In FIG. Figure 3 shows the design of a thermal indication stacker, which consists of a TNCM in a polymer matrix 7, a base (substrate) 8 and an adhesive layer 9. Existing methods and procedures for indicating using visual inspection, hand-held pyrometers or thermal imagers make it possible to detect the temperature state only at the time of direct verification, when the defect may be absent and does not allow to reliably determine the temperature in hard-to-reach places or places outside the line of sight of the detectors.

Serial production of stackers is carried out by the method of coordinate layout of a mixture of polymer and TNCM on a modified substrate with an adhesive layer.

Depending on the operating conditions, silicone, polyurethane, PVA, epoxy resin, paraffin, etc. can be used as a polymer matrix.

In FIG. Figure 4 shows a coordinate printing machine, consisting of a vacuum table 10, a roller nozzle 11 and a dispenser hopper 12. The advantage of the printing technology is the fast and accurate application of polymer with TNCM according to a pattern specified by the program, a fixed / uniform layer thickness and a layout width that is controlled by setting the feed rate polymer, the dimensions of the roller and the degree of pressure of the nozzle. It is possible to use rollers with texture patterns or ribbed edges for a double pass with a coordinate shift in order to better lay out the polymer.

Pressed paper, PET, BOPP or polypropylene is used as a substrate, including those with textured perforations made by running the material through needle rollers or made on a laser engraving machine. As a substrate, other types of self-adhesive materials are used, including metallized, reflective and having textured patterns applied by embossing, screen printing or other. rubber:

1) Polyurethane, hardener and no more than 20-30% TNCM are mixed in a planetary mixer to a homogeneous technological mixture.

2) The prepared technological mixture is filled into the dispenser hopper 12.

3) On the vacuum table 10, a polypropylene substrate with an adhesive layer is fixed according to the marked risks or a stencil.

4) At the command of the operator, the machine, according to the trajectory / pattern specified by the program, lays out the polymer by rolling the roller with a precisely specified force and pressing time.

5) Finished blanks are placed on drying racks, where the complete curing of the polymer takes place within at least 24 hours.

6) Products that have passed drying are cut to the required size using a printing or manual guillotine, sorted and packed in a shipping container.

Temperature Tests

For quality control and testing, a 3rd sample is randomly selected from a batch of finished thermal indication stickers with an activation temperature of 80 ° C, 120 ° C and 250 ° C (hereinafter Sample 1/1, Sample 1/2 and Sample 1/3) . Samples are weighed, visually assessed for quality and uniformity of appearance, and measured for length, width, thickness and weight before and after testing.

Temperature test procedure

To carry out temperature tests of thermal indication stickers, the 3rd type of iron boxes with a volume of 100, 500 and 1000 liters are prepared. During the tests, an electric heating element with a heating controller, an electronic thermometer, a pyrometer, a gas analyzer and a video camera are installed inside the boxes. To ensure the inflow of fresh air, several holes with a diameter of at least 4 cm are made in the bottom of the boxes. To ensure the outflow of heated air in order to maintain a stable internal temperature, a hole with a diameter of at least 5 cm is made in the upper part of the boxes. software for video stream analysis.

Findings and Conclusions

A batch of thermal indication stickers is considered to have successfully passed the temperature tests if the test results match those indicated in Table No. 3.

Sample No. 2 Thermal indication fire extinguishing plates

The main disadvantage of self-contained fire extinguishing installations manufactured using the "Thermo OTV" technology in the form of fire extinguishing plates in accordance with GOST P 56459-2015 is the inability to visually or electronically determine the complete or partial operation of the product (release of the fire extinguishing agent), as well as the performance and amount of the remaining active fire extinguishing agent after temperature exposure or fire extinguishing (work).

In FIG. 5 shows the design of a thermal indication fire extinguishing plate, which consists of a mixture of TNCM and a microencapsulated fire extinguishing agent in a polymer matrix 13, a base (substrate) 14 and an adhesive layer 15.

Depending on the operating conditions, silicone, polyurethane, epoxy resin, etc. can be used as a polymer matrix. Combined materials or specialized coatings can be used to make the finished product resistant to aggressive media and long-term thermal effects.

Depending on the operating conditions, ABS, PET, acrylic, polystyrene, polypropylene, etc. sheet plastic can be used as a substrate. Multilayer compositions can be used, including those with light and IR reflective coatings. Plates glued in the upper part of the protected volume can be partially or completely subjected to temperature effects close to or higher than the activation temperature (120±5°C) and lose part of the contained active fire extinguishing agent. Without dismantling the product and control weighing on a specialized laboratory scale in order to identify the total mass loss of the contained fire extinguishing agent or the built-in temperature sensor, the performance of the product cannot be determined.

In order to improve the technical characteristics of fire extinguishing plates and facilitate the visual identification of the product's performance, it is proposed to add TNCM to the polymer matrix. It is known that the fire-extinguishing agent, due to the non-uniformity of heating, does not come out uniformly over the entire area of the fire-extinguishing plates. Activated TNCM will change the color of the plate in the places of thermal heating and release of the extinguishing agent, visually showing the degree of temperature effect on the plates (work).

In FIG. 6 shows a machine for cassette printing of thermal indication fire extinguishing plates, consisting of forming cassettes 16, a deposit head 17 and a cassette conveyor 18.

The production cycle of plates consisting of a silicone polymer matrix 13, a substrate of polystyrene sheet 14 and an adhesive layer 15 of acrylic adhesive with residual tack:

1) Silicone, hardener, microencapsulated extinguishing agent and no more than 10-20% TNCM are mixed in a planetary mixer to a homogeneous process mixture.

2) The prepared technological mixture is filled into the hopper of the jigging head 17.

3) A3, A4 or A5 base blank substrates are loaded into forming cassettes 16.

4) Prepared cassettes are loaded into the conveyor feeder 18.

5) At the command of the operator, the machine automatically captures the cassette from the feeder, transports it along the conveyor, lays out the polymer by depositing a given volume of the technological mixture into the stencil window of the cassette and unloads the workpieces into the receiver.

6) Finished blanks are removed from their cassettes and placed on drying racks, where the complete curing of the polymer takes place within at least 24 hours.

7) Products that have been dried are cut to the required size using a printing or manual guillotine, sorted and packed in a shipping container.

Temperature Tests

For quality control and testing, a 3rd sample with an activation temperature of 110 ± 1 ° C - 120 ± 1 ° C is selected from a batch of finished thermal indication fire extinguishing plates by random sampling (hereinafter Sample 2/1, Sample 2/2 and Sample 2/3 ). Samples are weighed, visually assessed for quality and uniformity of appearance, and measured for length, width, thickness and weight before and after testing.

Temperature test procedure

To carry out temperature tests of thermal indication fire extinguishing plates, the 3rd type of iron boxes with a volume of 20, 30 and 65 liters are being prepared. During the tests, an electric heating element with a heating controller, an electronic thermometer, a pyrometer, a gas analyzer and a video camera are installed inside the boxes.

To ensure the inflow of fresh air, several holes with a diameter of at least 4 cm are made in the bottom of the boxes. To ensure the outflow of heated air in order to maintain a stable internal temperature, a hole with a diameter of at least 5 cm is made in the upper part of the boxes. software for video stream analysis.

Findings and Conclusions

A batch of thermal indication fire extinguishing plates is considered to have successfully passed the temperature tests if the test results match the results indicated in Table 4.

Sample No. 3 Thermal indication threads

The use of heat-indicating threads woven into the structure of textile products: fabrics, ribbons, stockings, braids and sheathing is at the same time one of the methods for controlling the process of braiding or sewing production, as well as registering places of local heating of the product used above the allowable temperature value. Thermal indication threads integrated into the structure of the braid of fire-extinguishing cords filled with gas-emitting or aerosol-generating compounds will make it possible to visually detect points of thermal effects, as well as the drawdown (release of the extinguishing agent) of the product itself. The fire extinguishing cord distributed by a snake from top to bottom will allow using it as a volumetric indicator of overheating of the protected volume, as well as detecting the place of a possible fire or activation with an accuracy of several centimeters.

In FIG. Figure 7 shows the design of a thermal indication thread, which consists of TNCM in a polymer matrix 19, a twisted carrier thread 20 and a protective layer (sizing) 21.

As a polymer matrix, depending on the operating conditions of the finished product, silicone, polyurethane, PVA, epoxy resin, paraffin, etc. are used.

As a carrier thread, depending on the operating conditions of the finished product, lavsan, polypropylene, fiberglass, arselon, synthetic and other threads can be used.

Depending on the operating conditions of the finished product, starch, cellulose ethers, synthetic resins and other materials can be used as a coupling agent. It is allowed to use finishing in several layers to impart the required properties: non-shrinkage, crease resistance, incombustibility, resistance to moisture, etc.

In FIG. 8 shows a machine for the production of thermal indication threads of the broaching principle of operation, consisting of a broaching mechanism 22, a chamber for applying a polymer mixture 23 and a chamber for applying a sizing 24.

The production cycle of heat-indicating threads consisting of lavsan threads 19 twisted into the 3rd turn, a polymer matrix of sodium alginate 20 and a sizing 21 of plasticized nitrolac:

1) Several lavsan threads are twisted on a rewinding machine and 5000-10000 meters long are wound on a technological reel.

2) Sodium alginate, distilled water and not more than 30-40% TNCM are mixed in a planetary mixer to a homogeneous process polymer mixture.

3) Calcium lactate and distilled water are mixed in a planetary mixer to a homogeneous technological mixture of hardener.

4) Technological mixtures of polymer and hardener are poured into separate tanks of the polymer mixture application chamber 23.

5) The plasticized nitro-varnish is poured into the tank of the chamber for applying the sizing 24.

6) The prepared thread on the technological spool is loaded into the broaching mechanism and passed through the guide rolls, drying fans and nozzles of chambers 23 and 24.

7) At the command of the operator, a tensioned thread from the process spool at a speed of 5-20 cm / min. is sequentially pulled through the tank of the polymer mixture and the hardener tank of chamber 23, as well as the tank with the dressing of chamber 24, drying fans, nozzles and a length of 1000-2500 meters are wound on a reel.

8) Products wound on a bobbin that have passed the final drying are labeled, sorted and packed in a shipping container.

Temperature tests For quality control and testing, a 3rd sample is randomly selected from a batch of finished thermo-indicating threads with an activation temperature of 80 ° C, 120 ° C and 250 ° C (hereinafter Sample 3/1, Sample 3/2 and Sample 3/ 3). Samples are weighed, visually assessed for quality and uniformity of appearance, and measured for length, width, thickness and weight before and after testing.

Temperature test procedure

To carry out temperature tests of the threads, the 3rd type of iron boxes with a volume of 100, 200 and 300 liters are prepared. During the tests, several electric heating elements with a heating controller, an electronic thermometer, a pyrometer, a gas analyzer and a video camera are installed inside the boxes in different places. To ensure the inflow of fresh air, several holes with a diameter of at least 4 cm are made in the bottom of the boxes. To ensure the outflow of heated air, in order to maintain a stable internal temperature, a hole with a diameter of at least 5 cm is made in the upper part of the boxes. The thread is fixed with a snake from above using self-adhesive fasteners down with a step of 20-25 cm. The activation time of the TNCM is fixed using a gas analyzer and specialized software for analyzing the video stream.

Findings and Conclusions

A batch of heat-indicating threads is considered to have successfully passed the temperature tests if the test results coincide with the results indicated in Table No. 5.

The tests carried out on nanocapsules have demonstrated a decrease in the flammability and non-sustaining of combustion of finished products based on them, in particular, due to a decrease in peak heat release, in contrast to conventional fire retardants such as magnesium hydroxide or aluminum trihydrate.

Industrial Applicability

The inventions can be used to detect electrical faults at an early stage and prevent fires in various volumes, such as sockets, switches, junction boxes, switchboards, electrical cabinets, cabinets and control panels, safes, server racks, complete switchgear (KRU) and other objects with a degree of protection IP20 and higher. TNCM can be used as:

- pigment additive in the manufacture of paints and varnishes;

- filler in various polymer compositions to give finished products thermo-indicative and odorizing properties;

- filler in the manufacture of wire braid and plastic products (boxes, junction boxes, etc.) using cold casting or casting technology.

Claims (12)

1. Thermochromic nanoencapsulated material, including nanocapsules with an odorant, containing a core located inside a shell of a polymeric material used to generate a signal about local overheating of electrical equipment by simultaneously releasing an odorant and changing the color of the material with increasing temperature, characterized in that the material is distributed in polymer binder nanocapsules with a core of thermochromic substance, located in a multilayer modified polymer shell containing a layer with an odorant and a protective antipyretic layer, in the following ratio of components, wt.%: thermochromic core 84-88 polymer shell 5-7 plasticizer 3-5 odorant layer 2-3 protective flame retardant layer 2-3, while the nanocapsules are activated in the temperature range of 50-250°C, the outer diameter of the nanocapsules is 40-60 microns, the average thickness of the layer with the odorant is 2-3 microns, the average thickness of the protective flame retardant layer is 2-3 microns. 2. The material according to claim 1, characterized in that as a thermochromic substance, substances are used that have a color transition in the temperature range from 50 to 250 ° C, such as complex compounds: [Fe(MoO ₄ ) ₆ ](NH ₄ ) ₃ *7H ₂ O with a color transition at 80°C, CoSO ₄ *2[(CH ₂ ) ₆ N ₄ ]*9H ₂ O with a color transition at 110°C, PO ₄ [Co(NH ₃ ) ₆ ] with a color transition at 230°C. 3. The material according to claim 1, characterized in that polymers are used as a polymer shell: cyanoacrylate, sodium alginate, epoxy resins, polyurethane, synthetic rubbers, or mixtures thereof. 4. The material according to claim 1, characterized in that glycerol, dioctyl phthalate (DOP), dibutyl phthalate (DBP) or mixtures thereof are used as a plasticizer for the polymer shell. 5. The material according to claim 1, characterized in that ethyl mercaptan, tetrahydrothiophene, dimethyl sulfide are used as the odorant. 6. The material according to claim 1, characterized in that polymer-layered silicates (nanocomposites) are used as a protective flame retardant layer: pyrophyllite - Al ₂ [Si ₄ O ₁₀ ]⋅ (OH) ₂ and / or montmorillonite (MMT) - Na _x (Al _4⋅x , Mg _x ) ₂ ⋅Si ₈ O ₂₀ ⋅ (OH) ₄ and / or orthosilicate - Na ₂ Si ₈ O ₇₉ (OH) ₂ . 7. A method for obtaining a thermochromic nanoencapsulated material according to claim 1, including the following stages: crushing, sieving and separating the thermochromic substance to a homogeneous fine fraction of 30-50 μm, preparing a mixture of a polymer with a plasticizer, dividing it into parts, preparing a mixture with an odorant and a mixture with nanocomposites , which are then fed into separate tanks of the dosing unit, the polymer hardener is loaded into a separate tank of the dosing unit, the resulting thermochromic substance is electrified with static electricity and loaded into the layer spraying chamber, sprayed with dry compressed air and the mixture of polymer with odorant is fed, at the end of the spraying cycle it is covered with a formed layer of the uncured shell, the raw material is deposited in the reaction chamber and the hardener is sprayed and the polymer is cured, the obtained raw material is transferred by reverse from the reaction chamber to the layer deposition chamber and the mixture of the mentioned polymer and nanocomposite is sprayed, after the end of the spray cycle With a blowing layer of an uncured shell, the raw material from the layer spraying chamber is deposited into the reaction chamber and the hardener is sprayed and the polymer is cured, after the end of the layers spraying and shell curing cycles, the finished material is obtained, which is unloaded into a technological container, sorted and packed in a shipping container. 8. Thermochromic nanoencapsulated product, made in the form of a structural product, characterized in that it contains thermochromic nanoencapsulated material, made according to any one of paragraphs. 1-6. 9. The product according to claim 8, characterized in that it is made in the form of a thermal indication sticker or a plate consisting of a thermochromic nanoencapsulated material and a substrate with an adhesive layer. 10. The product according to claim 8, characterized in that it is made in the form of a thermochromic thread, the sheath of which contains a carrier thread and a thermochromic nanoencapsulated material.

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