JP7827436B2 - A method for converting a flammable or flame-retardant substrate or part into a substrate or part that has both heat resistance capable of withstanding temperatures of 840°C and fire resistance capable of withstanding temperatures of 840°C. - Google Patents

Description

The present invention relates to a method for converting a flammable or flame-retardant substrate or part into a substrate or part that has both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding temperatures of 840°C, by covering the entire outer surface of the substrate or part that is exposed to the outside with a coating having a structure in which metal nanoparticles made of a metal having a melting point higher than 840°C are metallically bonded to each other and the metal-bonded metal nanoparticles are stacked together, and the coating provides the substrate or part with airtightness that isolates it from the outside.
Prior to the present invention, the inventor filed Japanese Patent Application No. 2019-169866 (filed September 18, 2019) relating to a method for covering a flammable or flame-retardant substrate or part with a collection of two types of fine particles consisting of aluminum oxide fine particles and maghemite fine particles to make the substrate or part non-flammable. Here, the difference between the two methods will be explained.
The prior application relates to a method for converting a flammable or flame-retardant substrate or part into a non-flammable one by covering the substrate or part with an aggregate of two types of fine particles, aluminum oxide and maghemite.In contrast, the present invention relates to a method for converting a flammable or flame-retardant substrate or part into a substrate or part that has both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding temperatures of 840°C by covering the substrate or part with a coating having a structure in which aggregates of metal nanoparticles that are metallically bonded to each other and are laminated together, the coating being made of a metal having a melting point higher than 840°C.
In other words, in the prior application, a magnetic attraction force acting between ferromagnetic maghemite particles is applied to a cluster of nonmagnetic aluminum oxide particles, forming a coating from a cluster of two types of particles. To achieve this, a cluster of two types of particles, aluminum oxide and ferrous oxide, is simultaneously precipitated, and the ferrous oxide particles are then oxidized to form maghemite particles. Furthermore, to increase the magnetic attraction force acting on the maghemite particles, a magnetization process is performed to saturate the magnetization of the maghemite particles. In contrast, in the present invention, regardless of whether the metal is ferromagnetic or nonmagnetic, metal nanoparticles made of a metal with a melting point higher than 840°C are metallically bonded to each other, and a coating consisting of a layer of clusters of these metallically bonded metal nanoparticles covers a substrate or component. Therefore, in the present invention, it is sufficient to precipitate a cluster of metal particles only once.
As will be described in detail in paragraph 7, the specifications for the insulating performance of the fire-resistant layer of a fire-resistant electric wire or fire-resistant cable are based on the idea that the most stringent heat resistance is specified, and the maximum temperature in the event of a fire is set at 840°C. Therefore, the non-flammability in this invention is defined as a property that combines heat resistance that can withstand 840°C and fire resistance that can withstand temperatures of 840°C.
Furthermore, aluminum oxide, a non-magnetic material made of metal oxide, does not allow metallic bonding between particles at contact points, nor does it magnetically attract to each other. On the other hand, maghemite begins a phase transition to weakly ferromagnetic hematite above 530°C, completing the phase transition at 640°C, with all maghemite replaced by hematite. Furthermore, above 675°C, the magnetism emitted by the hematite particles disappears, eliminating the magnetic attraction that bonds the particles together. For this reason, in the prior application, a group of aluminum oxide and ferrous oxide particles was simultaneously precipitated, followed by application of compressive stress to a substrate or component to bond the particles together by frictional heat, and the group of particles precipitated on the surface of the substrate or component was then frictionally bonded to the surface of the substrate or component, and a coating consisting of the group of particles bonded by frictional heat was then bonded to the surface of the substrate or component. Therefore, if the substrate or part is not planar, the substrate or part is placed in a mold having a groove with dimensions equivalent to the outer shape of the substrate or part. After two types of particle clusters are precipitated, compressive stress is applied to the substrate or part in the mold, causing the particles to bond together through frictional heat, and the clusters of particles precipitated on the surface of the substrate or part are bonded to the surface of the substrate or part through frictional heat. However, if the outer surface of the substrate or part exposed to the outside world is uneven, it is difficult to bond the clusters of particles precipitated on the surface of the substrate or part to the entire surface of the substrate or part through frictional heat. Furthermore, vibration acceleration is applied to the mold in three directions, and the substrate or part is peeled off from the mold and removed from the mold. In contrast, in the present invention, a coating made up of clusters of metal nanoparticles bonded together forms an airtight coating that blocks the outside world. This airtight coating covers the entire outer surface of the substrate or part exposed to the outside world, eliminating the need to apply compressive stress to the metal particles. This allows a flammable substrate or part to be converted into a non-flammable substrate or part even if the substrate or part has weak mechanical strength.
Furthermore, in the present invention, a substrate or a part is immersed in a paste, the paste is absorbed into the substrate or part, and then the substrate or part is heat-treated to thermally decompose the metal compound, and the entire outer surface of the substrate or part is covered with a coating made up of a layer of aggregates of metal nanoparticles bonded together. Therefore, even if the shape of the substrate or part is not flat, the paste is absorbed onto the entire outer surface of the substrate or part. Therefore, a process of applying compressive stress to the substrate or part is not necessary.
Furthermore, in the prior application, the sizes of the two types of fine particles, aluminum oxide and maghemite, are 40-60 nm. In contrast, in the present invention, the size of the metal fine particles is approximately 10 nm. Because the size of the fine particles is approximately 1/5 smaller, the gaps formed between adjacent fine particles follow the size of the fine particles and are nearly 1/5 narrower. Therefore, by randomly stacking more than 10 layers of metal-bonded metal fine particles, there are no gaps penetrating the group of metal fine particles, and the coating consisting of the group of stacked metal fine particles becomes an airtight coating that blocks the outside world. Therefore, the thickness of the airtight coating in the present invention is more than 1/2 thinner than that of the prior application. As a result, the airtight coating has almost no mass. As a result, there is almost no increase in weight of the substrate or part that has been converted to non-flammable.
As explained above, the present invention has various advantages over the prior art.
Next, prior to the present invention, the inventor has registered a patent, Patent No. 6792834 (filed on October 7, 2016), relating to a non-flammable paint in which an inner coating is made of a multilayer structure of stacked clusters of metal-bonded metal particles, and an outer coating is made of a coating of an organic compound whose boiling point is higher than the thermal decomposition temperature of a metal compound that precipitates metal through thermal decomposition, covering a flammable substance with this double-layered coating, thereby turning the flammable substance into a non-flammable substance.
In addition, the present invention proposes an invention relating to a method for producing a paste that converts a flammable or flame-retardant substrate or part into a non-flammable substrate or part by covering the flammable or flame-retardant substance with an airtight coating.
Here, the difference between the two will be explained.
As described above, the present invention sets the maximum temperature in the event of a fire at 840°C, and the non-combustibility in this invention is a property that combines heat resistance that can withstand 840°C and fire resistance that can withstand temperatures of 840°C. Therefore, a substrate or part is covered with a collection of metal nanoparticles that are layered with a collection of metal nanoparticles that are metal-bonded together and made of a metal with a melting point higher than 840°C, thereby converting a flammable or flame-retardant substrate or part into a non-combustible substrate or part. In contrast, the registered patent does not consider the property of combining heat resistance to 840°C and fire resistance to be non-combustible.
In other words, the organic compound forming the outer coating in the registered patent has a boiling point 50°C or more higher than the thermal decomposition temperature of the metal compound. Specifically, because the metal compound is an octylate metal compound that thermally decomposes at 290°C and precipitates metal, an organic compound belonging to aromatic carboxylic acid esters with a boiling point of 340°C or higher and an ignition point of 390°C or higher was used as the organic compound. Therefore, the vaporized organic compound ignites at temperatures higher than 390°C. Therefore, the non-flammability of the registered patent is limited to temperatures below 390°C. In contrast, the present invention covers a substrate or component only with a cluster of metal nanoparticles, which are layers of metal-bonded metal nanoparticles. Therefore, the boiling point of the organic compound in the present invention is lower than the thermal decomposition temperature of the metal compound, and it vaporizes before the metal compound thermally decomposes. In other words, the organic compound vaporizes before covering the substrate or component with the coating. As a result, the coating composed of a cluster of metal nanoparticles in the present invention is non-flammable, able to withstand temperatures up to 840°C.
Furthermore, the size of the metal microparticles in the present invention is about 1/5 of the size of the metal microparticles in the registered patent. Therefore, the voids formed between adjacent metal microparticles are also about 1/5 of the size of the registered patent. Therefore, by randomly stacking more than 10 layers of metal-bonded metal microparticles, voids penetrating the cluster of metal microparticles are eliminated, and the coating consisting of the cluster of metal microparticles becomes an airtight coating that blocks the outside world. Therefore, even if the layer of stacked metal microparticles is thinner than the layer of metal microparticles in the registered patent, an airtight coating can be formed. Therefore, in the registered patent, a coating consisting of an organic compound is not formed. On the other hand, in order to make the coating airtight, the thickness of the organic compound coating is about twice as thick as the coating consisting of the cluster of metal microparticles.
The thickness of the airtight coating that blocks the outside world in the present invention is thinner than the layer of metal particles in the registered patent. Therefore, the viscosity of the paste in the present invention is set to be lower than 2 mPa·s at 20°C, and the thickness of the paste that is adsorbed onto the substrate or part is set to be thinner than 1 μm. Therefore, the organic compound used in the present invention has a lower viscosity than the organic compound in the registered patent, and a lower boiling point than the organic compound in the registered patent.
As explained above, the present invention has various advantages over issued patents.

Article 109-2 of the Building Standards Act Enforcement Order, which regulates fire protection equipment, defines the 20-minute flame-blocking period after heat from a fire is applied as the flame-blocking period and stipulates that the fire protection equipment must not emit flames on surfaces other than the heated surface during the flame-blocking period. Examples of such fire protection equipment include fire doors, fire and smoke shutters, fire and smoke dampers, fire and smoke hanging walls, fire and smoke sheets, fire and smoke screens, fire and smoke panels, and drenchers. The requirement for this fire protection equipment is that it must be flame-retardant, preventing flames from emitting on surfaces other than the heated surface for the first 20 minutes of a fire, rather than requiring the fire protection equipment itself to be non-flammable. However, it is not guaranteed that everyone will be able to evacuate a burning building within 20 minutes of the fire's outbreak. Furthermore, if fire protection equipment burns after 20 minutes of a fire's outbreak, its fire-blocking function will be impaired, allowing the fire to spread. Therefore, regardless of the scale of the fire, if fire prevention equipment is non-flammable, it will continue to perform its fire prevention function in the event of a fire, and this has a significant effect.

On the other hand, when describing flame resistance, which indicates difficulty in burning, "non-flammable" is used as the property of not burning continuously, "flame retardant" as the property of burning slowly and for only a short time, "self-extinguishing" as the property of burning while exposed to flame but extinguishing once removed from the flame, and "slow-flame" as the property of not self-extinguishing but having a slow burning speed. However, because there are few cases where these properties are specified as performance, there are cases where "slow-flame" is confused with "non-flammable," as mentioned above.
As a provision related to flame resistance, for example, there is a certification standard for non-combustible materials among fire-resistant materials (based on Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1178), which stipulates that when exposed to fire, the material will not burn for 20 minutes after the start of the application of fire force, will not cause damage harmful to fire prevention, and will not generate smoke or gases harmful to evacuation. Similar to Article 109-2 of the Enforcement Order of the Building Standards Act mentioned above, this provision is a flame-retardant provision limited to the 20-minute period after the application of fire force, and is not a non-combustible provision.
Furthermore, JIS-K6911 defines the non-combustibility of thermosetting resins as follows: a 5 x 0.5 x 0.5 inch test piece is exposed to a flame for 30 seconds, and after the flame is removed, the burning of the test piece is extinguished within 180 seconds, and the length of the burned test piece is 1 inch or less. JIS-K6911 also defines self-extinguishing as the burning of the test piece is extinguished within 180 seconds, and the length of the burned test piece is 1 inch or more and 4 inches or less. This definition of non-combustibility of thermosetting resins refers to the property that combustion does not continue once the flame is removed, and not the non-combustibility property of thermosetting resins that prevents them from burning when exposed to flame.
Furthermore, fire-resistant electric wires and cables maintain the insulating performance of the fire-resistant layer to ensure emergency power supply in the event of a fire, allowing current to flow for a certain period of time. They are used in wiring for various emergency equipment (emergency elevators, indoor fire hydrants, smoke exhaust systems, etc.) specified by the Fire Service Act and the Building Standards Act. The fire-resistant layer's insulating properties are required to be certified by testing at the Japan Electric Wire & Cable Makers' Association (JCS) based on Fire and Disaster Management Agency regulations (Technical Standards based on Ministry of Home Affairs Fire and Disaster Management Agency Notification No. 10, December 18, 1997), and must have insulating properties that can withstand heating according to a fire temperature curve that reaches 840°C in 30 minutes. Furthermore, heat-resistant electric wires and cables are required to have insulating properties that can withstand heating according to a fire temperature curve that reaches 380°C in 15 minutes, and must be certified by testing at the Japan Electric Wire & Cable Makers' Association (JCS) based on the Fire and Disaster Management Agency regulations. Therefore, while the insulating performance of the fire-resistant layer in fire-resistant electric wires and cables is the strictest, it does not require the fire-resistant layer to be non-combustible.

Meanwhile, various flame retardants made from materials different from conventional flame retardants are being developed. Patent Document 1 proposes a flame-retardant paint primarily composed of high-purity bentonite and soap-free emulsion resin. However, bentonite's molecular structure becomes unstable above 400°C, and its gas barrier properties deteriorate in high-temperature environments above 400°C. Furthermore, the cost of purifying bentonite into a fine powder containing 85% or more by weight of montmorillonite is not inexpensive. Furthermore, emulsion resins meet the aforementioned non-combustibility requirements of the Building Standards Act, meaning that even if they do not burn for 20 minutes after heating begins, they will burn if heated for a longer period of time. Bentonite is an inorganic substance made from a type of clay mineral and has traditionally been used as a precipitation inhibitor in paints.
Patent Document 2 proposes an inorganic and organic hybrid non-flammable paint whose main components are a powder made by blending white cement with inorganic aggregate and a fire retardant, and then kneading this powder with a liquid agent made of an aqueous emulsion resin. However, to improve the fire retardancy of a paint with this composition, the blending ratio of white cement, inorganic aggregate, and fire retardant must be increased. However, the higher the inorganic fire retardant content, the higher the viscosity of the paint, which reduces the workability of coating film formation. Furthermore, adhesion to the substrate is poor, and the coating film properties deteriorate over time. Furthermore, even though aqueous emulsion resin meets the fire retardancy requirements of the Building Standards Act, i.e., it does not burn for 20 minutes after heating begins, it can still burn if heated for a longer period of time.
The acrylic resin used in emulsion resins begins to thermally decompose at temperatures around 370°C in the atmosphere, and decomposes into methyl methacrylate, which has a boiling point of 101°C and an ignition point of 421°C, methyl acrylate, which has a boiling point of 80°C and an ignition point of 468°C, and related compounds. Dibutyl phthalate, a typical plasticizer, has a boiling point of 340°C and an ignition point of 402°C. Therefore, when a flammable material is coated with a non-flammable paint containing emulsion resin and a plasticizer as ingredients, the coating film thermally decomposes at temperatures below 400°C, losing its non-flammability, and the flammable material produced by the thermal decomposition ignites.

Japanese Patent Application Laid-Open No. 20016-117810 Japanese Patent Application Laid-Open No. 20013-043891

Journal of Mineralogy, Vol. 16, No. 3, 253-264, November 1983 Industrial Chemistry Journal, Vol. 66, No. 11 (1963) 92-96 Journal of the Mining Industry of Japan, Vol. 98, No. 1133 (July 1982) 575-578

The aforementioned non-flammable paint stipulated in the Building Standards Act satisfies the three requirements for the first 20 minutes of a fire; more accurately, it is a retardant fire-proofing provision. However, it is not always possible for everyone to evacuate a burning building within 20 minutes of the fire's outbreak. Furthermore, if non-flammable paint burns after 20 minutes, flammable materials may ignite from the coating, causing the fire to spread and generating smoke or gases that are harmful to evacuation. Therefore, if non-flammable paint could be transformed into a truly non-flammable paint that does not self-ignite or catch fire, it would remain non-flammable in any fire, providing significant benefits in terms of disaster prevention.
Here, we compare properties such as fire resistance, flame resistance, flame retardancy, self-extinguishing, and flame retardancy with the property of non-combustibility. If a substrate or component does not burn in a fire of any scale or substance, i.e., a fire involving flammable or combustible gases, flammable or flammable liquids, or flammable or non-combustible solids, that is, if the substrate or component is non-combustible, then the substrate or component possesses all of the properties of fire resistance, flame resistance, flame retardancy, self-extinguishing, and flame retardancy. Therefore, properties such as fire resistance, flame resistance, flame retardancy, self-extinguishing, and flame retardancy are included in the term non-combustibility. Therefore, a non-combustible substrate or component possesses all of the properties of fire resistance, flame resistance, flame retardancy, self-extinguishing, and flame retardancy. Therefore, achieving non-combustibility involves more technical difficulties than achieving fire resistance, flame resistance, flame retardancy, self-extinguishing, and flame retardancy.
Next, we consider the maximum temperature during a fire. The standard for the maximum temperature during a fire is the insulating performance of the fire-resistant layer of a fire-resistant electric wire or cable. In other words, fire-resistant electric wires or cables maintain the insulating performance of the fire-resistant layer to ensure emergency power supply during a fire and are capable of carrying electricity for a certain period of time. These wires or cables are used in various emergency equipment (emergency elevators, indoor fire hydrants, smoke exhaust systems, etc.) specified by the Fire Service Act and the Building Standards Act. The insulating performance of the fire-resistant layer is required to be certified by testing at the Japan Electric Wire & Cable Makers' Association (JCS) based on the Fire and Disaster Management Agency's regulations (Technical Standards based on Ministry of Home Affairs Fire and Disaster Management Agency Notification No. 10, December 18, 1997), and must be able to withstand heat according to a fire temperature curve that reaches 840°C in 30 minutes. Furthermore, heat-resistant electric wires or cables are required to be certified by testing at the Japan Electric Wire & Cable Makers' Association (JCS) based on the Fire and Disaster Management Agency's regulations, and must be able to withstand heat according to a fire temperature curve that reaches 380°C in 15 minutes. Therefore, the regulations for the insulating performance of the fire-resistant layer in a fire-resistant electric wire or fire-resistant cable are the strictest, but they do not specify the incombustibility of the fire-resistant layer so that it will not burn in the event of a fire.
Based on the regulations for the insulating performance of the fire-resistant layer of this fire-resistant electric wire or fire-resistant cable, the maximum temperature during a fire is set at 840°C, and the non-flammability in this invention is defined as a property that combines heat resistance and fire resistance at 840°C. Here, we consider the technical challenges to achieve non-flammability of a substrate or component even at 840°C during a fire.
The first objective is to cover a flammable or flame-retardant substrate or part with a coating that is heat-resistant and fire-resistant up to 840°C. In other words, the flammable or flame-retardant substrate or part will decompose reliably at temperatures lower than 840°C. On the other hand, if the substrate or part is covered with a coating that is heat-resistant and fire-resistant up to 840°C, none of the substances produced by pyrolysis will be emitted to the outside. As a result, black smoke and harmful gases will not be emitted, the black smoke will not obscure visibility, and harmful gases will not cause disasters. In addition, the flammable substances produced by pyrolysis will not self-ignite or ignite. As a result, they will not create a fire start point or allow the fire to spread.
The second problem is that the coating has airtight properties that block the outside world. Therefore, oxygen gas is not supplied to the substrate or component even at 840°C. On the other hand, combustion is an oxidation reaction with oxygen gas. If the substrate or component is isolated from the outside world by a coating that is heat-resistant and fire-resistant up to 840°C, the substrate or component will not self-ignite or ignite even when heated to a temperature exceeding its ignition point or flash point. Furthermore, even if the substrate or component undergoes thermal decomposition, the flammable substances produced by the thermal decomposition will not self-ignite or ignite. Furthermore, the pyrolyzed flammable substances will not be emitted to the outside, and will not self-ignite or ignite. In other words, by covering the substrate or component with a coating that is heat-resistant and fire-resistant up to 840°C and has airtight properties that block the outside world even at 840°C, the substrate or component will become non-flammable. Therefore, the first object of the present invention is to find a method for producing a coating that has heat resistance and fire resistance up to 840°C and that is airtight enough to block out the outside world even at 840°C, and a method for covering a flammable or flame-retardant substrate or part with said coating.
Incidentally, most buildings use flammable or flame-retardant substrates or components, i.e., products whose main components are organic materials such as synthetic resins, wood, and paper, or products that are composites with organic materials. For this reason, the benefits of covering flammable or flame-retardant substrates or components with a coating that is heat-resistant and fire-resistant up to 840°C and that is airtight enough to block out the outside world even at 840°C would be extremely significant. However, no coating currently provides such benefits.
Meanwhile, flammable or flame-retardant substrates or parts are used in various products within buildings, and their surface conditions, shapes, sizes, and materials are diverse. Therefore, all flammable or flame-retardant substrates or parts must be covered with an airtight coating that has heat resistance and fire resistance at 840°C and that blocks the outside world even at 840°C. Therefore, a second object of the present invention is to cover a flammable or flame-retardant substrate or part with a coating that has heat resistance and fire resistance at 840°C and that is airtight even at 840°C, regardless of the surface condition, material, shape, and size of the substrate or part.

The method for producing a paste for converting a flammable or flame-retardant substance into a substance having both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding a temperature of 840°C in the present invention is as follows:
a metal compound having both a first property of being dispersed in methanol in a molecular state but not dissolved in methanol and a second property of precipitating a metal having a melting point higher than 840°C upon thermal decomposition, is dispersed in methanol to prepare a methanol dispersion of the metal compound, and then the methanol is evaporated from the methanol dispersion of the metal compound to precipitate a collection of crystals of the metal compound as crystals smaller than 100 nm ;
Furthermore, the collection of metal compound crystals is filled into a container, and a plate material that covers the entire surface of the collection of metal compound crystals is placed on top of the collection of metal compound crystals. Thereafter, a compressive load equivalent to 10-50 kg weight is applied to the entire surface of the plate material depending on the size of the container, thereby crushing the metal compound crystals in the container. Furthermore, impact accelerations of 0.2-0.5 G are repeatedly applied to the sides and bottom of the container in three directions, front-to-back, left-to-right, and up-to-down, depending on the size of the container , to rearrange the crushed collection of metal compound crystals within the container. Thereafter, the entire surface of the plate material is again crushed. The compressive load is applied to further crush the metal compound crystals, and the impact acceleration in the three directions is again repeatedly applied to the side and bottom of the container. This pair of processes consisting of the process of applying the compressive load and the process of applying the impact acceleration is repeated, and when the plate stops moving when the compressive load is applied to the plate, it is determined that the crushing of the metal compound crystals is complete and the pair of processes is stopped. Thereafter, the plate is removed from the container. As a result, the size of the metal compound crystals becomes approximately 20 nm, which is nearly 1/5 of the size of the metal compound crystals at the time of precipitation.
Furthermore, a second organic compound having a first property of being soluble in a first organic compound having a viscosity of less than 1 mPa·sec at 20°C, a second property of not dissolving or dispersing the metal compound, a third property of having a boiling point higher than the boiling point of the first organic compound and lower than the thermal decomposition temperature of the metal compound, and a fourth property of having a viscosity of 4-7 mPa·sec at 20°C is dissolved in the first organic compound so that the viscosity at 20°C is lower than 2 mPa·sec, and the solution is mixed with the clusters of crushed crystals of the metal compound in the container to prepare a suspension in which the clusters of crushed crystals of the metal compound are dispersed in the solution .
A method for producing a paste for converting a flammable or flame-retardant substance into a substance having both heat resistance and fire resistance capable of withstanding temperatures of 840°C, wherein the suspension produced by the above-mentioned treatment is used as a paste for converting a flammable or flame-retardant substance into a substance having both heat resistance and fire resistance capable of withstanding temperatures of 840°C.

The paste of the present invention is prepared by the following three simple processes. Each process and the effects brought about by each process will be explained below.
In the first process, a cluster of crystals of the metal compound is precipitated. To this end, the metal compound is dispersed in methanol, and then the methanol is evaporated to precipitate a cluster of crystals of the metal compound. That is, when a metal compound that precipitates a metal with a melting point higher than 840°C upon thermal decomposition is dispersed in methanol, the most commonly used organic solvent, the metal compound becomes a molecular state and disperses in the methanol. In contrast, when a metal compound dissolves in methanol, the metal constituting the metal compound becomes a metal ion and dissolves in the methanol, and the dissolved metal compound cannot return to the metal compound before dissolution. Therefore, even if methanol is evaporated from a methanol solution of the metal compound, crystals of the metal compound before dissolution do not precipitate. Therefore, a metal compound that does not dissolve in methanol but disperses in methanol is used as a metal compound that precipitates a metal upon thermal decomposition. In this way, when methanol is evaporated from a methanol dispersion of the metal compound, the metal compound precipitates as crystals of the metal compound smaller than 100 nm. These crystals are a cluster of crystals formed by the accumulation of crystals formed by single molecules of the metal compound, since the metal compound dispersed in methanol in a molecular state precipitates as crystals. Therefore, when stress is applied to the crystals, they are crushed and become finer. On the other hand, the finer the crystals, the more difficult it is to apply stress to them, and there is a limit to how fine the crystals can be made. Commonly used metals with melting points lower than 840°C include tin, lead, zinc, magnesium, and aluminum, in descending order of melting point. Therefore, the metal compound used in the present invention precipitates metals other than these five types of metals through thermal decomposition. Furthermore, the vaporized methanol is recovered in a recovery machine and reused.
In the second process, the metal compound crystals are crushed to about 1/5 of their original size. To this end, a container is filled with a collection of metal compound crystals, and a plate is placed over the collection of metal compound crystals in the container to constrain the collection of metal compound crystals within the container, compressing the collection of metal compound crystals via the plate. In this process, the larger the crystal size, the more easily it is crushed. Therefore, relatively larger crystals are crushed first, and the crushing of the crystals progresses while the compressive load is applied. Meanwhile, in the collection of crystals within the container, new voids are formed by the crushing of the crystals, and while the compressive load is applied, the crystals move to fill the voids. After this, the applied compressive load is stopped, and impact acceleration is repeatedly applied to the container in three directions: front-to-back, left-to-right, and up-to-down. At this time, the crystals do not scatter because they are constrained within the container by the plate, but instead move to fill the voids, and the crushed collection of crystals is rearranged within the container. Furthermore, after the applied impact acceleration is stopped, a compressive load is again applied to the crushed collection of crystals via the plate. At this time, the crushed crystals described above are crushed against the cluster of finer crystals. After this, three-directional impact acceleration is repeatedly applied to the container again to further promote rearrangement of the cluster of finer crystals. A pair of processes consisting of a process of applying a compressive load and a process of applying three-directional impact acceleration is repeated. On the other hand, the finer the crystals, the more difficult it becomes to apply compressive stress to the crystals even when a compressive load is applied, and there is a limit to how much the crystals can be refined. When the limit of crystal refinement is reached, applying a compressive load to the plate material does not further fracture the crystals, and no movement is observed in the plate material to which the compressive load is applied. At this point, the pair of processes is stopped. As a result, the size of the crystals becomes approximately 20 nm, nearly 1/5 of the size at the time of precipitation. The compressive load applied to the plate material is a compressive load equivalent to 10-50 kg weight, depending on the size of the container. The impact acceleration applied to the container is 0.2-0.5 G, depending on the size of the container.
In the third process, a second organic compound having a viscosity of 4-7 mPa·sec at 20°C is dissolved in a first organic compound having a viscosity of less than 1 mPa·sec at 20°C so that the viscosity of the solution at 20°C is less than 2 mPa·sec. The solution is then mixed with the aggregate of crushed crystals of the metal compound to form a suspension. The crushed crystals of the metal compound are extremely fine, measuring approximately 20 nm, and the crushed crystals have almost no mass. The viscosity of the solution is less than 2 mPa·sec at 20°C. Therefore, even if the weight of the solution is less than the weight of the aggregate of crushed crystals, the aggregate of crushed crystals is easily dispersed uniformly in the solution. The metal compound is neither dissolved nor dispersed in either the first organic compound or the second organic compound. Therefore, in the suspension, the metal compound is neither dissolved nor dispersed in the solution. In other words, the organic compound in which the metal compound disperses is limited to linear aliphatic alcohols having four or fewer carbon atoms.
The suspension prepared by the three processes described above is used as a paste to convert flammable or flame-retardant materials into non-flammable materials. Since the viscosity of the solution is less than 2 mPa·s at 20°C, the thickness of the paste applied to the substrate or part is less than 1 μm.
In addition, the metal compound, the first organic compound, and the second organic compound used in the production of the paste are all general-purpose industrial chemicals. Furthermore, all three of the above-mentioned processes are simple. Therefore, the paste can be produced at low cost.

A method for converting a substrate or part made of a combustible or flame-retardant material into a substrate or part that is heat-resistant and fire-resistant to a temperature of 840°C, using the suspension described in paragraph 8 as a paste for converting a combustible or flame-retardant material into a material that is heat-resistant and fire-resistant to a temperature of 840°C, comprises the steps of:
The paste is filled into a container, and a substrate or a part made of a flammable or flame-retardant material is entirely immersed in the paste in the container, and then the substrate or the part is removed from the container, and a coating made of the paste and having a thickness of less than 1 μm is adsorbed onto the entire outer surface of the substrate or the part exposed to the outside.
Thereafter, the substrate or the part is exposed to an atmosphere in which the fine crystals of the metal compound crushed to a size of about 20 nm as described in paragraph 8 are thermally decomposed, and further, the temperature is raised to a temperature at which the fine crystals of the metal compound are thermally decomposed, whereby the first organic compound described in paragraph 8 and the second organic compound described in paragraph 8 are vaporized in order according to their boiling points, after which the thermal decomposition of the fine crystals of the metal compound having a size of about 20 nm begins, the fine crystals of the metal compound having a size of about 20 nm are decomposed into inorganic molecules or organic molecules and metal molecules, the inorganic molecules or the organic molecules absorb the heat of vaporization and are vaporized , and the inorganic molecules or the moment the evaporation of the organic molecules is completed, the aggregation of the metal molecules forms metal nanoparticles with a size of about 10 nm, and aggregations of metal nanoparticles with a size of about 10 nm made of a metal with a melting point higher than 840°C precipitate all at once on the entire outer surface of the substrate or the part exposed to the outside world, the precipitated metal nanoparticles are metallically bonded at the sites where they come into contact with each other, and the metallically bonded aggregations of metal nanoparticles are stacked, so that the entire outer surface of the substrate or the part exposed to the outside world is covered with an airtight coating that blocks the outside world and is made of the metallic nanoparticles that are stacked together.
As a result, the entire outer surface of the substrate or part made of a flammable or flame-retardant material that is exposed to the outside world is covered with an airtight coating that blocks the outside world and is made of a collection of metal nanoparticles stacked with collections of metal-bonded metal nanoparticles, and the substrate or part made of a flammable or flame-retardant material is transformed into a substrate or part that has both heat resistance that can withstand temperatures of 840°C and fire resistance that can withstand temperatures of 840°C.This is a method for transforming a substrate or part made of a flammable or flame-retardant material into a substrate or part that has both heat resistance that can withstand temperatures of 840°C and fire resistance that can withstand temperatures of 840°C.

The following two simple treatments are used to transform a flammable or flame-retardant substrate or part into a substrate or part that is heat-resistant to 840°C and fire-resistant to 840°C. Each treatment method and the effects of each treatment are described below.
In the first treatment, the entire substrate or component is immersed in the paste, the substrate or component is removed from the container, and a paste having a thickness of less than 1 μm is adsorbed onto the entire outer surface of the substrate or component exposed to the outside. To achieve this, the viscosity of a solution obtained by dissolving a second organic compound in a first organic compound is reduced to less than 2 mPa·s at 20° C. so that the thickness of the paste adsorbed onto the substrate or component is less than 1 μm. Note that because the viscosity of the solution is low, the paste having a thickness of less than 1 μm is adsorbed onto the entire outer surface of the substrate or component exposed to the outside, regardless of the surface irregularities, size, or shape of the substrate or component.
In the second treatment, the substrate or part to which the paste is adsorbed is exposed to an atmosphere in which the fine crystals of the metal compound crushed to a size of approximately 20 nm are thermally decomposed, and the temperature is then raised to a temperature at which the fine crystals of the metal compound are thermally decomposed. During this treatment, the first organic compound and the second organic compound are vaporized in order according to their boiling points. The vaporized first organic compound and second organic compound are recovered and reused. After this, the fine crystals of the metal compound, each approximately 20 nm in size , begin to thermally decompose, and the fine crystals of the metal compound, each approximately 20 nm in size, decompose into inorganic or organic molecules and metal molecules. The inorganic or organic molecules absorb the heat of vaporization and vaporize. The vaporized inorganic or organic molecules are recovered and reused. At the moment when the vaporization of the inorganic or organic molecules is complete, the metal molecules form metal nanoparticles approximately 10 nm in size, and metal nanoparticles made of metals with melting points higher than 840°C precipitate simultaneously on the entire outer surface of the substrate or component exposed to the outside world. Therefore, a huge number of metal nanoparticles precipitate depending on the moles of the metal compound that thermally decomposes. Furthermore, when the metal compound thermally decomposes, all impurities contained in the paste, such as moisture, organic matter, and hydroxides, whose boiling points are lower than the thermal decomposition temperature of the metal compound, vaporize . When the metal nanoparticles precipitate simultaneously, the metal nanoparticles bond with each other at the contact points, and the metal-bonded metal nanoparticles stack up, covering the entire outer surface of the substrate or component exposed to the outside world with an airtight coating thicker than 100 nm that blocks the outside world.
Here, we will explain the effect of covering the entire outer surface of a substrate or part exposed to the outside world with a coating consisting of a layered structure of metal nanoparticles made of a metal with a melting point higher than 840°C, which are bonded to each other through metal bonding.
First, it is possible to cover a substrate or part with an airtight coating that blocks the outside world, regardless of the surface irregularities, size, or shape of the substrate or part, thereby converting a flammable or flame-retardant substrate or part into a substrate or part that has both heat resistance (capable of withstanding temperatures of 840°C) and fire resistance (capable of withstanding temperatures of 840°C).
Second, the coating has mechanical strength based on the metallic bonding force between the metal particles. That is, each metal particle constituting the coating comes into contact with and forms a metallic bond with a total of 16-18 metal particles, consisting of six adjacent metal particles on the same layered surface and five or six adjacent metal particles on the upper and lower layers. Therefore, the coating has enough mechanical strength to withstand being destroyed even if the substrate or part is dropped from a height of about 2 m.
Third, the coating has airtightness that blocks the outside world. In other words, the coating is made up of granular metal nanoparticles with a size of about 10 nm that are randomly stacked without any gaps, and adjacent metal nanoparticles are metallically bonded to each other. During this process, voids are formed between adjacent nanoparticles, but when metal-bonded nanoparticles are randomly stacked, the voids are filled, and when more than 10 metal-bonded nanoparticles are randomly stacked, there are no interconnected voids in the cluster of metal-bonded nanoparticles. Therefore, a coating made up of a structure in which clusters of metal-bonded metal nanoparticles are stacked has airtightness that blocks the outside world.
Fourth, the coating has metallic properties. That is, since the coating is composed of a collection of metal particles, the coating has the properties of the metal that makes up the metal particles. This gives the substrate or part covered with the coating the electrical and thermal conductivity of a metal. The coating also functions as an electromagnetic wave shielding film and an antistatic film.
Fifth, the coating repels all liquids. That is, the surface of the coating is made up of metal particles with a size of about 10 nm that are metallically bonded. Therefore, due to the surface tension of the liquid, the liquid is repelled by the surface of the coating and cannot penetrate into the interior of the coating. Therefore, the non-flammable substrate or part can be used for a long period of time, both in liquid and outdoors.
Sixth, the coating has both water repellency and antifouling properties. That is, the surface of the coating is made of metal particles of about 10 nm in size that are bonded together, resulting in an extremely high degree of flatness of the surface of the coating. As a result, the coating has both water repellency and antifouling properties, and foreign matter does not adhere to the coating. Therefore, the non-flammable substrate or part can be used outdoors for a long period of time.
Seventh, the coating has excellent sliding properties. That is, the surface of the coating is extremely flat and smooth because metal nanoparticles with a size of approximately 10 nm are metallically bonded. Therefore, when other substrates or parts slide on the coating, the other substrates or parts slide on the surface of the coating. Furthermore, the contact area of the other substrates or parts that come into contact with the metal nanoparticles is extremely small. Therefore, the coating acts as a lubricating coating with a low coefficient of friction. Meanwhile, the thickness of the coating is very thin, although it is thicker than 100 nm. However, because the coating wears slowly, the effects it provides last a long time.
Eighth, even if the temperature to which the substrate or part coated with the coating is exposed changes suddenly during a fire, the bonding strength between the fine particles does not change. In other words, the thermal expansion and contraction of fine particles, which are approximately 10 nm in size, is extremely small. Therefore, even if the temperature to which the substrate or part is exposed changes suddenly during a fire, the coating hardly experiences any thermal expansion or contraction. Therefore, the metallic bonding strength between the metal fine particles does not change, and the coating will not be destroyed even by the sudden temperature change that occurs during a fire.
Ninth, the coating has heat resistance and fire resistance close to the melting point of the metal that constitutes the metal microparticles. On the other hand, general-purpose metals with melting points lower than 840°C include tin, lead, zinc, magnesium, and aluminum, in order of decreasing melting point. If metals other than these five types of metals are used as metal compounds that precipitate by thermal decomposition, the coating will have both heat resistance that can withstand temperatures higher than 840°C and close to the melting point of the metal, and fire resistance that can withstand temperatures higher than 840°C and close to the melting point of the metal. Therefore, since the maximum temperature during a fire is 840°C, the coating will have both heat resistance and fire resistance regardless of any fire it encounters.
In a fire, the coating may be exposed to temperatures higher than the temperature at which the metal compound thermally decomposes and metal nanoparticles precipitate. In this case, the metal nanoparticles, excluding those on the surface of the substrate or component, are isolated from the outside world, and thus the impurity-free metal nanoparticles are reactivated. As the temperature rises, the metal nanoparticles gradually change shape from granular to flattened particles, resulting in particle coarsening. Therefore, the higher the temperature, the more the nanoparticles flatten. Meanwhile, as the nanoparticles flatten, the volume of the contact areas between metal nanoparticles that are in contact with each other vertically and horizontally increases, increasing the volume of the metal bonding areas. This increases the mechanical strength of the coating and improves its airtightness, which isolates it from the outside world. Furthermore, as the temperature approaches the metal's melting point, the flattened particles form a metallic bond, and the coating approaches an extremely thin metallically bonded film. Therefore, the coating's airtightness, which isolates it from the outside world, is continuously maintained, and it is not destroyed even when subjected to impact during a fire. As a result, the coating maintains its airtightness to withstand temperatures of 840°C.
Tenth, the surface of the coating has a metallic luster, which imparts flame retardancy and metallic luster to the substrate or part, thereby adding new value to the substrate or part.
Eleventh, the coating has almost no weight. In other words, since the coating is made up of more than 10 metal nanoparticles of about 10 nm stacked together, the coating has almost no weight. Therefore, by imparting non-combustibility to a substrate or part, there is almost no increase in the weight of the substrate or part.
Twelfth, the coating can be formed in two simple steps using an inexpensive paste made from inexpensive materials and simple processes. Therefore, the coating that provides various effects is inexpensive.
As a result, all of the problems described in paragraph 7 are solved.
As described above, the coating of the present invention that covers the entire outer surface of a substrate or component not only imparts to the substrate or component heat resistance capable of withstanding temperatures of 840°C and fire resistance capable of withstanding temperatures of 840°C, but also provides many other excellent effects.

A method for producing a paste for converting a flammable or flame-retardant substance described in paragraph 8 into a substance having both heat resistance and fire resistance capable of withstanding temperatures of 840°C, the paste comprising:
The metal compound described in paragraph 8 is an inorganic metal compound composed of an inorganic salt having a metal complex ion in which an inorganic molecule or an inorganic ion acts as a ligand and is coordinately bonded to a metal ion, and the inorganic metal compound is used as the metal compound described in paragraph 8 to produce a paste according to the method described in paragraph 8 , which converts a flammable or flame-retardant substance described in paragraph 8 into a substance having both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding a temperature of 840°C.

In other words, when an inorganic-metal compound consisting of an inorganic salt having a metal complex ion coordinated to a metal ion, with inorganic molecules or ions as ligands, is heat-treated in a reducing atmosphere, the coordinate bond is first broken and the compound decomposes into the inorganic substance and the metal. As the temperature is further increased, the inorganic substance absorbs the heat of vaporization and vaporizes. Vaporization of the inorganic substance is completed in the temperature range of 180-220°C, and the metal molecules gather together, resulting in the deposition of the metal.
As described in paragraph 9, repeated crushing of metal compound crystals leads to crushing down to crystals of about 20 nm in size. Therefore, when fine crystals of an inorganic metal compound of about 20 nm in size are thermally decomposed, metal nanoparticles of about 10 nm in size are precipitated after the inorganic substance is vaporized.
That is, among the ions constituting the inorganic metal compound, the metal ion located at the center of the molecule is the largest, and the distance between the metal ion and the ligand is the longest. When this inorganic metal compound is heat-treated in a reducing atmosphere, the coordinate bond between the metal ion and the ligand is first broken, resulting in decomposition into the metal and the inorganic substance. As the temperature rises further, the inorganic substance absorbs the heat of vaporization and vaporizes. Once the inorganic substance has completely vaporized, the metal precipitates, completing the thermal decomposition. The temperature at which the metal precipitates is the lowest of all temperatures at which metal precipitates during the thermal decomposition of metal compounds. Therefore, the cost of heat treatment is low. Furthermore, inorganic metal compounds composed of inorganic salts containing metal complex ions disperse in methanol at nearly 10% by weight and are insoluble in methanol. Therefore, inorganic metal compounds can be used as metal compounds that combine the two properties described in paragraph 8.
That is, metal complex ions in which inorganic molecules or inorganic ions function as ligands and are coordinated to metal ions are easier to synthesize than other metal complex ions. Examples of such metal complex ions include ammine metal complex ions in which ammonia (NH3 ₎ functions as a ligand and is coordinated to a metal ion; aqua metal complex ions in which water ( _H2O ) functions as a ligand and is coordinated to a metal ion; hydroxo metal complex ions in which hydroxyl groups (OH- ⁾ function as ligands and are coordinated to a metal ion; and chloro metal complex ions in which chloride ions (Cl- ⁾ or chloride ions (Cl- ⁾ and ammonia (NH3 ₎ function as ligands and are coordinated to a metal ion. Furthermore, inorganic metal compounds containing such metal complex ions and inorganic salts such as chlorides, sulfates, and nitrates are easy to synthesize. Because the molecular weight of the inorganic salt is low, the inorganic compounds vaporize completely and the metal precipitates in a temperature range of 180-220°C. This temperature is the lowest temperature at which metals precipitate through the thermal decomposition of metal compounds. These inorganic metal compounds are common industrial chemicals.

A method for producing a paste for converting a flammable or flame-retardant material as described in paragraph 8 into a material having both heat resistance capable of withstanding temperatures of 840°C and fire resistance capable of withstanding temperatures of 840°C, comprising the steps of:
The metal compound described in paragraph 8 is a metal octylate compound, and a paste is produced according to the method described in paragraph 8 using the metal octylate compound as the metal compound described in paragraph 8, and a method for producing a paste that converts a flammable or flame-retardant substance described in paragraph 8 into a substance that has both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding a temperature of 840°C.

In other words, when metal octylate compounds are heat-treated at 290°C in an air atmosphere, they precipitate metal. Furthermore, they disperse in methanol at nearly 10% by weight, but are insoluble in methanol. Therefore, metal octylate compounds can be used as metal compounds that combine the two properties described in paragraph 8.
As described in paragraph 9, repeated crushing of metal compound crystals leads to crushing down to crystals of about 20 nm in size. Therefore, when fine crystals of a metal octylate compound of about 20 nm in size are thermally decomposed, metal nanoparticles of about 10 nm in size are precipitated after the octylate is vaporized.
That is, among the ions constituting the metal octylate compound, the metal ion is the largest. Therefore, in a metal octylate compound in which the oxygen ion constituting the carboxyl group of octylic acid is covalently bonded to a metal ion, the distance between the oxygen ion constituting the carboxyl group and the metal ion is longer than the distance between other ions. When a metal octylate compound with such molecular structure is heat-treated in an air atmosphere, the bond between the oxygen ion constituting the carboxyl group and the metal ion is first broken when the temperature exceeds the boiling point of octylic acid, 228°C, and the compound separates into octylic acid and the metal. Furthermore, since octylic acid is a saturated fatty acid, it does not have an unsaturated structure in which carbon atoms are in excess of hydrogen atoms. Therefore, the octylic acid absorbs the heat of vaporization and vaporizes, and the metal precipitates at 290°C, when vaporization is complete. Furthermore, when a metal octylate compound is heat-treated in a nitrogen atmosphere, the metal precipitates at 340°C. On the other hand, when a synthetic resin, which has a relatively low thermal decomposition temperature, is heated in a nitrogen atmosphere, the thermal decomposition temperature of the synthetic resin shifts to a higher temperature because the thermal decomposition reaction of the synthetic resin is an endothermic reaction rather than an exothermic reaction. Therefore, when a substrate or part is made of a synthetic resin, it is preferable to thermally decompose the metal octylate compound in a nitrogen atmosphere.
In other words, metal carboxylate compounds in which the carboxylate anion (R—COO ⁻ ) of a carboxylic acid composed of saturated fatty acid is covalently bonded to a metal ion precipitate a metal upon thermal decomposition. Examples of such metal carboxylate compounds, in order of decreasing thermal decomposition temperature at which they precipitate a metal, include metal octylate compounds, metal laurate compounds, and metal stearates. Therefore, by using metal octylate compounds, which have the lowest thermal decomposition temperature, the suspension described in paragraph 7 can be produced inexpensively. Note that, like metal octylate compounds, metal laurate compounds and metal stearates compounds disperse in methanol at nearly 10% by weight and are insoluble in methanol.
That is, the boiling point of lauric acid is 296°C, and the thermal decomposition temperature of metal laurate compound is 360°C. However, the thermal decomposition temperatures of metal laurate compound and metal stearate compound are higher than that of metal octylate compound. Therefore, it is desirable to use metal octylate compound as a raw material for depositing metal.
Compared to carboxylic acid metal compounds made from saturated fatty acids, carboxylic acid metal compounds made from unsaturated fatty acids have an excess of carbon atoms relative to hydrogen atoms, and therefore, upon thermal decomposition, metal oxides, such as copper oleate, are precipitated simultaneously as copper (I) oxide (Cu ₂ O) and copper (II) oxide (CuO), resulting in the cost of reducing the copper (I) oxide and copper (II) oxide to copper. In particular, copper (I) oxide must be oxidized to copper (II) oxide in an atmosphere richer in oxygen than air, and then further reduced to copper in a reducing atmosphere, resulting in increased processing costs. For this reason, preferred metal compounds that precipitate metals upon thermal decomposition are carboxylic acid metal compounds in which the carboxylate anion (R—COO ⁻ ) of a carboxylic acid made from saturated fatty acids is covalently bonded to the metal ion.
Furthermore, metal octylate compounds are inexpensive industrial chemicals that can be easily synthesized. That is, when octylic acid is reacted with a strong alkali, an alkali metal octylate compound is produced. Then, when the alkali metal octylate compound is reacted with an inorganic metal compound, metal octylate compounds composed of various metals are produced. Furthermore, octylic acid is a commonly used organic acid. Therefore, metal octylate compounds are the least expensive organometallic compounds. Therefore, although their thermal decomposition temperature is higher than that of the complexes composed of inorganic metal compounds described in paragraph 13, they are less expensive metal compounds than the complexes.

A method for producing a paste for converting a flammable or flame-retardant material as described in paragraph 8 into a material having both heat resistance capable of withstanding temperatures of 840°C and fire resistance capable of withstanding temperatures of 840°C, comprising the steps of:
When the metal compound described in paragraph 8 is an inorganic metal compound composed of an inorganic salt having a metal complex ion in which an inorganic molecule or an inorganic ion acts as a ligand and is coordinately bonded to a metal ion, When the second organic compound having the four properties described in paragraph 8 is an organic compound belonging to the alcohols having a boiling point higher than that of the first organic compound and lower than 180°C , and when the metal compound described in paragraph 8 is a metal octylate compound, the second organic compound having the four properties described in paragraph 8 is an organic compound belonging to the alcohols having a boiling point higher than that of the first organic compound and lower than 290°C, and when the metal compound described in paragraph 8 is an inorganic metal compound, the second organic compound described in paragraph 8 is an organic compound belonging to the alcohols having a boiling point lower than 180°C, and when the metal compound described in paragraph 8 is a metal octylate compound, the second organic compound described in paragraph 8 is an organic compound belonging to the alcohols having a boiling point higher than 180°C but lower than 290°C, and when the metal compound described in paragraph 8 is a metal octylate compound, the second organic compound described in paragraph 8 is an organic compound belonging to the alcohols having a boiling point higher than 180°C but lower than 290°C, and when the first organic compound described in paragraph 8 is a method for producing a paste that converts a flammable or flame-retardant substance as described in paragraph 8 into a substance that has both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding a temperature of 840°C , the method comprising using an organic compound belonging to acetate esters as the first organic compound as described in paragraph 8, the organic compound having a first property of having a viscosity of less than 1 mPa·s at 20°C, a second property of being soluble in the second organic compound, and a third property of having a boiling point lower than the boiling point of the second organic compound, the paste being produced according to the method as described in paragraph 8.

The second organic compound having all four properties described in paragraph 8 includes an organic compound belonging to alcohols. Also, the first organic compound having a viscosity of less than 1 mPa·s at 20°C described in paragraph 8 includes an organic compound belonging to acetate esters.
First, the metal compound described in paragraph 8 is the inorganic metal compound described in paragraph 13, and an organic compound belonging to alcohols having a boiling point lower than 180° C. will be described.
3-Methyl-1-butanol (CH ₃ ) ₂ CH(CH ₂ ) ₂ OH has a viscosity of 3.7 mPa·sec at 20°C and a boiling point of 131°C.
Tertiary amyl alcohol _CH3CH2COH ( _CH3 ) ₂ has a viscosity _of 3.8 mPa·s at 20°C and a boiling point of 103°C.
2-butanol _CH3CH2CH (OH) _CH3 has a viscosity of 3.9 mPa· _s at 20°C and a boiling point of 99°C.
2-Methyl-1-butanol _CH3CH2CH ( _CH3 ) _CH2OH has a viscosity of 4.0 mPa·sec at 20°C and _a boiling point of 108°C.
2-Heptanol _CH3 ( _CH2 ) _4CH (OH) _CH3 has a viscosity of 4.0 mPa·s at 20°C and a boiling point of 159°C.
Isobutyl alcohol ( _CH3 ) _2CHCH2OH has a viscosity of 4.0 mPa·sec at 20°C and _a boiling point of 108°C.
4-Methyl-2-pentanol (CH ₃ ) ₂ CHCH ₂ CHOHCH ₃ has a viscosity of 4.1 mPa·s at 20°C and a boiling point of 132°C.
2-Octanol _CH3 ( _CH2 ) _5CH (OH) _CH3 has a viscosity of 6.2 mPa·s at 20°C and a boiling point of 178°C.
3-Pentanol _CH3CH2CH (OH) _CH2CH3 has a viscosity of 6.4 _mPa ·s at 20°C and _a boiling point of 116°C.
1-heptanol CH ₃ (CH ₂ ) ₆ OH has a viscosity of 7.4 mPa·sec at 20°C and a boiling point of 176°C.
These 10 types of alcohols have the following characteristics: a first property of being soluble in acetate esters; a second property of not dissolving or dispersing crystals of metal compounds; a third property of having a boiling point higher than that of acetate esters and lower than the thermal decomposition temperature of inorganic metal compounds; and a fourth property of having a viscosity of 4-7 mPa sec at 20°C.
Next, the metal compound described in paragraph 8 is the metal octylate compound described in paragraph 15, and is an organic compound belonging to alcohols having a boiling point higher than 180°C and lower than 290°C.
1-Octanol CH ₃ (CH ₂ ) ₇ OH has a boiling point of 194°C and a viscosity of 7.3 mPa·sec at 25°C.
1-Octanol has a first property of being soluble in acetate esters, a second property of not dissolving or dispersing crystals of the metal compound, a third property of having a boiling point higher than that of acetate esters and lower than the thermal decomposition temperature of the metal octylate compound, and a fourth property of having a viscosity of 4-7 mPa sec at 20°C.
Next, the above-mentioned alcohol-soluble acetate esters having a viscosity of less than 1 mPa·sec at 20° C., and a viscosity of 4-7 mPa·sec at 20° C. will be described.
Methyl acetate _CH3COOCH3 has a viscosity of 0.366 _mPa ·s at 21°C and a boiling point of 57°C.
Ethyl acetate _CH3COOCH2CH3 has a viscosity of 0.462 _mPa ·s at 25°C and _a boiling point of 77°C.
Isopropyl acetate _CH3COOCH ( _CH3 ) ₂ has a viscosity of 0.525 mPa·s at 20°C and a boiling point of 89°C.
Normal propyl acetate _CH3COO ( _CH2 ) _2CH3 has a viscosity of 0.6 _mPa ·s at 20°C and a boiling point of 101°C.
Isobutyl acetate is _CH3COOCH2CH ( _CH3 ) ₂ , has a viscosity of 0.68 mPa·sec at 20°C and _a boiling point of 118°C.
Normal butyl acetate _CH3COOC4H9 has a viscosity of 0.738 _mPa ·sec at 20 _° C and a boiling point of 126°C.
These six organic compounds belonging to acetate esters have a viscosity of less than 1 mPa·sec at 20°C and are soluble in the above-mentioned alcohols having a viscosity of 4-7 mPa·sec at 20°C.

FIG. 1 is a cross-sectional view illustrating a melamine decorative board covered with a cluster of copper particles.

Example 1
This example shows a melamine decorative panel covered with a cluster of copper particles. Note that the melting point of copper is 1085°C, which is higher than the maximum temperature of 840°C in the event of a fire, as described in paragraph 1.
Melamine decorative laminates are a type of surface material used in furniture, fixtures, and other applications requiring strength. They are made by impregnating printed paper and kraft paper with melamine resin and phenolic resin, respectively, and then layering the dried impregnated papers together under a pressure of 100 kg/ ^cm² at 150°C. Melamine resin decomposes into low-molecular-weight chars at 230-320°C in ambient air. The resulting charred residue undergoes slow thermal decomposition at 320-475°C and burns at 475-570°C. For novolac phenolic resins, desorption of flammable plasticizers begins around 260°C and continues until around 360°C. After this, endothermic thermal decomposition of the polymer begins at 390°C, producing flammable gases such as phenol and cresol. The decomposition process ends around 700°C, leaving behind a solid residue (ash) of 65%. Therefore, the phenolic resin also burns due to thermal decomposition in the atmosphere.
Tetraammine copper nitrate [Cu(NH ₃ ) ₄ ](NO ₃ ) ₂ (e.g., a product of Mitsuwa Chemical Co., Ltd.) was used as the copper compound. 3-methyl-1-butanol (e.g., a product of Fujifilm Wako Pure Chemical Industries, Ltd.), which has a viscosity of 3.7 mPa·s at 20°C and a boiling point of 131°C, was used as the second organic compound. Furthermore, isobutyl acetate (e.g., a product of Fujifilm Wako Pure Chemical Industries, Ltd.), which has a viscosity of 0.68 mPa·s at 20°C and a boiling point of 118°C, was used as the first organic compound.
First, 51 g (equivalent to 0.2 moles) of tetraamine copper nitrate was dispersed in methanol to a concentration of 10 wt %. The methanol dispersion of tetraamine copper nitrate was then heated to 65°C, the methanol evaporated, and a cluster of tetraamine copper nitrate crystals was precipitated. The cluster of tetraamine copper nitrate crystals was then transferred to a 6 cm x 6 cm x 2 cm container. A 6 cm x 6 cm x 1 cm plate was then placed over the cluster of tetraamine copper nitrate crystals, and five 1 kg weights were placed evenly spaced on the plate. The weights were then removed, and impact accelerations of 0.2 G were repeatedly applied to the sides and bottom of the container in three directions: front-to-back, left-to-right, and up-to-down. After three cycles of applying compressive loads and impact accelerations, the weights were placed on the plate. Since there was no movement of the plate, it was considered that the crushing of the tetraamine copper nitrate crystals was complete.
Furthermore, 35 cc of 3-methyl-1-butanol was dissolved in 65 cc of isobutyl acetate to give a viscosity of 1.7 mPa·sec at 20° C. A mass of crushed crystals of tetraammine copper nitrate was mixed with this solution to prepare a suspension, which was then filled into a container.
After this, five pieces measuring 5 cm x 5 cm were cut out from a 0.95 mm thick melamine decorative board (XJN2085KV04, a product of Aica Kogyo Co., Ltd.), the cut melamine decorative boards were immersed in the above-mentioned suspension, and the cut melamine decorative boards were removed from the suspension. The five melamine decorative boards were then passed through a heat treatment device in a hydrogen atmosphere heated to 200°C, and five samples were produced.
Next, one sample was cut in the center, and the surface and cross section of the sample were observed using an electron microscope. An ultra-low accelerating voltage SEM owned by JFE Techno Research Corporation was used as the electron microscope. This device allows surface observation at ultra-low accelerating voltages starting from 100 V, and allows direct surface observation without forming a conductive coating.
First, a secondary electron beam between 900-1000V of the reflected electron beam was extracted and image-processed to observe the surface of the sample. The surface of the sample was found to be evenly covered with granular particles approximately 10 nm in size. Next, the energy and intensity of the characteristic X-rays were image-processed to analyze the type of element that made up the particles formed on the surface. They were found to be copper particles. Therefore, the surface of the sample was covered with copper particles.
Next, the cross section of the sample was observed under an electron microscope. Clusters of around 15 particles were stacked tightly together, covering the melamine decorative laminate. Figure 1 shows a schematic diagram of the cross section of the sample. 1 is a cluster of copper particles, and 2 is the melamine decorative laminate.
When the sample was cut, the clusters of copper particles adjacent to the cut area did not dissociate from the surface of the sample. Therefore, the clusters of copper particles were bonded to the melamine decorative panel with a certain strength. Furthermore, five samples were allowed to fall naturally from a height of 2 m onto the floor, but no change was observed on the sample surface. Therefore, the clusters of copper particles were bonded with a certain strength.
Furthermore, four samples were left in a heat treatment device consisting of an air atmosphere at 840°C for two minutes. During this time, no flames, black smoke, or strange odors were generated from the samples. Furthermore, no abnormalities such as cracks were observed on the surface of the samples. After this, one sample was cut. When the sample was cut, the clusters of copper particles covering the surface of the sample did not crumble, but the ash of the melamine decorative board crumbled. From these results, it was found that the clusters of copper particles had both heat resistance and fire resistance at 840°C, and also coated the melamine decorative board with airtightness, making the melamine decorative board non-flammable.

Example 2
This example shows a natural wood veneer decorative plywood covered with clusters of copper particles. Natural wood veneer decorative boards are used as building materials such as flooring and fixtures, and as the surface decorative material for furniture. Multiple thin slices of wood, 0.2-0.6 mm thick, are glued to plywood, and the adhesive is dried at temperatures exceeding 100°C. Wood ignites at temperatures of 400-460°C in the atmosphere.
The copper compound used was copper octoate [ _CH3 ( _CH2 ) _3CH ( _C2H5 )COO] _2Cu (for example, a product of Mitsuwa Chemical Industries _, Ltd.). The second organic compound used was 1-octanol (for example, a product of Fujifilm Wako Pure Chemical Industries, Ltd.), which has a boiling point of 194°C and a viscosity of 7.3 mPa·s at 25°C. The first organic compound used was n-butyl acetate (for example, a product of Fujifilm Wako Pure Chemical Industries, Ltd.), which has a viscosity of 0.738 mPa·s at 20°C and a boiling point of 126°C.
First, 70 g (equivalent to 0.2 moles) of copper octylate was dispersed in methanol to a concentration of 10 wt %. The methanol dispersion of copper octylate was then heated to 65°C, the methanol was evaporated, and a cluster of copper octylate crystals was precipitated. The cluster of copper octylate crystals was then transferred to a 6 cm x 6 cm x 2 cm container. A 6 cm x 6 cm x 1 cm plate was then placed over the cluster of copper octylate crystals, and five 1 kg weights were placed evenly spaced on the plate. The weights were then removed, and an impact acceleration of 0.2 G was repeatedly applied to the sides and bottom of the container in three directions: front-to-back, left-to-right, and up-to-down. After repeating this process of applying a compressive load and impact acceleration three times, a weight was placed on the plate. Since there was no movement of the plate, it was considered that the crushing of the tetraammine copper nitrate crystals was complete.
Thereafter, 10 cc of 1-octanol was dissolved in 90 cc of normal butyl acetate to give a viscosity of 1.4 mPa·sec at 20° C. The resulting solution was mixed with a cluster of crushed copper octoate crystals to prepare a suspension, which was then filled into a container.
Five pieces of 5 cm x 5 cm were cut out of a 2.5 mm thick natural wood veneer decorative plywood (a straight grain ash product from Matsumoto Plywood Co., Ltd.), immersed in the suspension as in Example 1, and then passed through a heat treatment device in an air atmosphere at 290°C to create five samples.
The surface and cross section of the sample were observed under an electron microscope in the same manner as in Example 1. Clusters of copper particles were found to have precipitated on the surface of the sample. Furthermore, clusters of approximately 12 copper particles were stacked and covered the natural wood veneer decorative plywood.
When the sample was cut, the clusters of copper particles adjacent to the cut area did not dissociate from the surface of the sample. The clusters of copper particles were bonded to the natural wood veneer decorative plywood with a certain strength. Five samples were allowed to fall from a height of 2 m onto the floor, but no change was observed on the sample surface. Therefore, the clusters of copper particles were bonded with a certain strength.
Furthermore, as in Example 1, four samples were left in a heat treatment device in an air atmosphere at 840°C for two minutes. During this time, no flames, black smoke, or strange odors were generated from the samples. Furthermore, no abnormalities such as cracks were observed on the surface of the samples. After this, one sample was cut. When the sample was cut, the clusters of copper particles did not crumble, but the ash of the natural wood veneer decorative plywood crumbled. Therefore, the clusters of copper particles had both heat resistance and fire resistance at 840°C, and coated the natural wood veneer decorative plywood with airtightness, making the natural wood veneer decorative plywood non-flammable.

The two examples are only a partial list. In other words, by immersing a substrate or a component in the suspension and then thermally decomposing the copper compound adsorbed on the substrate or component, the surface of the flammable or flame-retardant substrate or component can be covered with a collection of copper fine particles. Furthermore, the metal fine particles are not limited to copper fine particles; the surface of the flammable or flame-retardant substrate or component can be covered with a collection of various metal fine particles precipitated by thermal decomposition of the metal compound.
That is, when a substrate or a part is immersed in the suspension, the suspension adheres to the surface of the substrate or part in accordance with the viscosity of the suspension, regardless of the material, shape, size, or surface condition of the substrate or part. In the two examples, a flat plate material was used, but even in the case of a part, when the part is immersed in the suspension, the suspension adheres to the surface of the part in accordance with the viscosity of the suspension, regardless of the material, shape, size, or surface condition of the part.
Furthermore, the thickness of the suspension adhered to the substrate or component is determined by the viscosity of the suspension. As a result, the number of copper microparticles stacked tightly on the substrate or component can be freely changed by adjusting the viscosity of the suspension. In the two examples, the number of copper microparticles stacked tightly on the substrate or component was approximately 12 and 15, respectively. However, all of the copper microparticles bonded to each other, and the copper microparticle clusters bonded to the substrate or component, so the copper microparticle clusters exhibited airtightness. Therefore, regardless of the material, shape, size, or surface condition of the substrate or component, the substrate or component can be covered with an airtight cluster of metal microparticles. Therefore, even at high temperatures of 840°C, the airtight cluster of metal microparticles provides non-flammability to the substrate or component. This non-flammability can be imparted to all flammable and flame-retardant substrates or components.

1. A collection of copper particles stacked together 2. Melamine decorative board

Claims (5)

A method for producing a paste that converts a flammable or flame-retardant material into a material that has both heat resistance and fire resistance to a temperature of 840°C, comprising the steps of:
a metal compound having both a first property of being dispersed in methanol in a molecular state but not dissolved in methanol and a second property of precipitating a metal having a melting point higher than 840°C upon thermal decomposition, is dispersed in methanol to prepare a methanol dispersion of the metal compound, and then the methanol is evaporated from the methanol dispersion of the metal compound to precipitate a collection of crystals of the metal compound as crystals smaller than 100 nm ;
Furthermore, the collection of metal compound crystals is filled into a container, and a plate material that covers the entire surface of the collection of metal compound crystals is placed on top of the collection of metal compound crystals. Thereafter, a compressive load equivalent to 10-50 kg weight is applied to the entire surface of the plate material depending on the size of the container, thereby crushing the metal compound crystals in the container. Furthermore, impact accelerations of 0.2-0.5 G are repeatedly applied to the sides and bottom of the container in three directions, front-to-back, left-to-right, and up-to-down, depending on the size of the container , to rearrange the crushed collection of metal compound crystals within the container. Thereafter, the entire surface of the plate material is again crushed. The compressive load is applied to further crush the metal compound crystals, and the impact acceleration in the three directions is again repeatedly applied to the side and bottom of the container. This pair of processes consisting of the process of applying the compressive load and the process of applying the impact acceleration is repeated, and when the plate stops moving when the compressive load is applied to the plate, it is determined that the crushing of the metal compound crystals is complete and the pair of processes is stopped. Thereafter, the plate is removed from the container. As a result, the size of the metal compound crystals becomes approximately 20 nm, which is nearly 1/5 of the size of the metal compound crystals at the time of precipitation.
Furthermore, a second organic compound having a first property of being soluble in a first organic compound having a viscosity of less than 1 mPa·sec at 20°C, a second property of not dissolving or dispersing the metal compound, a third property of having a boiling point higher than the boiling point of the first organic compound and lower than the thermal decomposition temperature of the metal compound, and a fourth property of having a viscosity of 4-7 mPa·sec at 20°C is dissolved in the first organic compound so that the viscosity at 20°C is lower than 2 mPa·sec, and the solution is mixed with the clusters of crushed crystals of the metal compound in the container to prepare a suspension in which the clusters of crushed crystals of the metal compound are dispersed in the solution .
A method for producing a paste for converting a flammable or flame-retardant substance into a substance having both heat resistance and fire resistance capable of withstanding temperatures of 840°C, wherein the suspension produced by the above-mentioned treatment is used as a paste for converting a flammable or flame-retardant substance into a substance having both heat resistance and fire resistance capable of withstanding temperatures of 840°C. A method for converting a substrate or part made of a combustible or flame-retardant material into a substrate or part that is heat-resistant and fire-resistant to a temperature of 840°C, by using the suspension according to claim 1 as a paste for converting a combustible or flame-retardant material into a material that is heat-resistant and fire-resistant to a temperature of 840°C, comprises the steps of:
The paste is filled into a container, and a substrate or a part made of a flammable or flame-retardant material is entirely immersed in the paste in the container, and then the substrate or the part is removed from the container, and a coating made of the paste and having a thickness of less than 1 μm is adsorbed onto the entire outer surface of the substrate or the part exposed to the outside.
Thereafter, the substrate or the part is exposed to an atmosphere in which the fine crystals of the metal compound crushed to a size of about 20 nm as described in claim 1 are thermally decomposed, and further, the temperature is raised to a temperature at which the fine crystals of the metal compound are thermally decomposed. As a result, the first organic compound as described in claim 1 and the second organic compound as described in claim 1 are vaporized in order according to their boiling points. After this, the thermal decomposition of the fine crystals of the metal compound having a size of about 20 nm begins, and the fine crystals of the metal compound having a size of about 20 nm are decomposed into inorganic molecules or organic molecules and metal molecules, and the inorganic molecules or organic molecules absorb the heat of vaporization and are vaporized , and the inorganic molecules Alternatively, at the moment when the evaporation of the organic molecules is completed, the aggregation of the metal molecules forms metal nanoparticles with a size of about 10 nm, and aggregations of metal nanoparticles with a size of about 10 nm made of a metal with a melting point higher than 840°C precipitate all at once on the entire outer surface of the substrate or the part exposed to the outside world, the precipitated metal nanoparticles are metallically bonded at the sites where they come into contact with each other, and the metallically bonded aggregations of metal nanoparticles are stacked, so that the entire outer surface of the substrate or the part exposed to the outside world is covered with an airtight coating that blocks the outside world and is made of the metallic nanoparticles that are stacked together.
As a result, the entire outer surface of the substrate or part made of a flammable or flame-retardant material that is exposed to the outside world is covered with an airtight coating that blocks the outside world and is made of a collection of metal nanoparticles stacked with collections of metal-bonded metal nanoparticles, and the substrate or part made of a flammable or flame-retardant material is transformed into a substrate or part that has both heat resistance that can withstand temperatures of 840°C and fire resistance that can withstand temperatures of 840°C.This is a method for transforming a substrate or part made of a flammable or flame-retardant material into a substrate or part that has both heat resistance that can withstand temperatures of 840°C and fire resistance that can withstand temperatures of 840°C. A method for producing a paste for converting a flammable or flame-retardant substance into a substance having both heat resistance and fire resistance capable of withstanding temperatures of 840°C according to claim 1, comprising the steps of:
A method for producing a paste that converts a flammable or flame-retardant substance as defined in claim 1 into a substance that has both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding a temperature of 840°C, wherein the metal compound defined in claim 1 is an inorganic metal compound composed of an inorganic salt having a metal complex ion in which an inorganic molecule or an inorganic ion acts as a ligand and is coordinately bonded to a metal ion, and the inorganic metal compound is used as the metal compound defined in claim 1 to produce a paste according to the method defined in claim 1. The method for producing a paste for converting a flammable or flame-retardant substance as described in claim 1 into a substance having both heat resistance capable of withstanding a temperature of 840°C and fire resistance capable of withstanding a temperature of 840°C, comprises the steps of:
A method for producing a paste that converts a flammable or flame-retardant substance described in claim 1 into a substance that has both heat resistance capable of withstanding temperatures of 840°C and fire resistance capable of withstanding temperatures of 840°C, wherein the metal compound described in claim 1 is a metal octylate compound, and the paste is produced according to the method described in claim 1 using the metal octylate compound as the metal compound described in claim 1. The method for producing a paste for converting a flammable or flame-retardant substance as described in claim 1 into a substance having both heat resistance capable of withstanding a temperature of 840°C and fire resistance capable of withstanding a temperature of 840°C, comprises the steps of:
When the metal compound described in claim 1 is an inorganic metal compound composed of an inorganic salt having a metal complex ion in which an inorganic molecule or an inorganic ion acts as a ligand and is coordinately bonded to a metal ion, the second organic compound having the four properties described in claim 1 is an organic compound belonging to alcohols having a boiling point higher than that of the first organic compound and lower than 180°C , and when the metal compound described in claim 1 is an octylic acid metal compound, the second organic compound having the four properties described in claim 1 is an organic compound having a boiling point lower than that of the first organic compound. When the metal compound described in claim 1 is an inorganic metal compound, the second organic compound described in claim 1 is an organic compound belonging to alcohols having a boiling point lower than 180°C, and when the metal compound described in claim 1 is an octylate metal compound, the second organic compound described in claim 1 is an organic compound belonging to alcohols having a boiling point higher than 180°C and lower than 290°C, and when the metal compound described in claim 1 is an octylate metal compound, the second organic compound described in claim 1 is an organic compound belonging to alcohols having a boiling point higher than 180°C and lower than 290°C, and A method for producing a paste that converts a flammable or flame-retardant substance as defined in claim 1 into a substance that has both heat resistance capable of withstanding 840°C and fire resistance capable of withstanding a temperature of 840°C, the method comprising using an organic compound that belongs to acetate esters and has a first property of having a viscosity at 20°C of less than 1 mPa·s, a second property of being soluble in the second organic compound, and a third property of having a boiling point lower than the boiling point of the second organic compound, the organic compound belonging to acetate esters being used as the first organic compound as defined in claim 1, and producing a paste according to the method as defined in claim 1.