Visual Over-Temperature Recording Device and Method of Manufacturing the Same (Multiple Embodiments)

Abstract

The present invention relates to a device for visually registering an excess temperature, i.e., a device for registering an excess temperature exceeding at least one threshold, whose operating principle is to change the microstructure of a heat-sensitive material at a predetermined temperature threshold with an irreversible visual effect, and to a variant of the manufacturing method of this device. The device for visually registering excess temperatures exceeding at least one threshold has a layer structure including: a substrate opaque to at least a portion of visible light, the front surface of which is inscribed with an indication of at least one numerical threshold temperature; at least one heat-sensitive material opaque to at least a portion of visible light, applied to a separate portion of the substrate, the heat-sensitive material having a microstructure containing solid organic particles and voids filled with a gas phase; and a transparent protective layer partially or completely covering the front surface of the device. In this case, the device has the ability to irreversibly change its appearance upon reaching at least one threshold temperature indicated thereon, with the microstructure of the corresponding heat-sensitive material being destroyed, the solid organic particles fusing, the proportion of voids decreasing, and an increase in transparency accompanied by the appearance of the base color. Also disclosed are embodiments of a method for manufacturing a device for visually detecting temperatures exceeding at least one threshold. The inventions provide improved reliability and reliability of the visual registration of the fact of a temperature exceeding at least one threshold, improved triggering speed of the heat-sensitive material, including the impossibility of returning the heat-sensitive material to its initial state, short-term peak loads of the device's control elements or conditions for emergency operation modes, as well as improved safety of operation of both the controlled device and the device itself.

Description

[Technical Field]

[0001] The present invention relates to a device for visually recording the occurrence of a temperature exceeding at least one threshold. The operating principle of the device is based on a microstructural change in a heat-sensitive material at a predetermined temperature threshold, which is accompanied by an irreversible visual effect. The present invention also relates to several embodiments of a method for manufacturing the device. [Background technology]

[0002] Level of technology Overheating is one of the first and most frequent signs of defects in various equipment: for example, increased contact resistance in the power industry, malfunctioning bearings in mechanical engineering, inter-turn short circuits in electric motor windings, charger or battery failure in household appliances, etc. Timely detection of such overheating allows for pre-emptive elimination of faults and prevents equipment breakdowns and emergencies, as well as the resulting fires and power outages. Technical and regulatory documents specify maximum permissible temperatures, exceeding which is considered a defect and requires immediate shutdown and removal of the equipment for repair (e.g., RD ​​34.45-51.300-97, RD 153-34.0-20.363-99, GOST 8865-93, 8024-90, 10693-81, 2213-79, 10434-82, 16708-84, 2585-81, 32397-2020, 26346-84, 839-2019, GOST R 51321.1-2007, etc.). Various diagnostic methods are used to detect defects related to exceeding the maximum permissible temperatures. The most widely used thermal diagnostic method is thermal imaging. However, thermal imaging has a fundamental limitation: it can only determine the heat distribution at the time of inspection. Since overheating of equipment is almost always directly related to its load, diagnostics at peak loads (such as rated current, starting current, and maximum speed) are the most informative and reliable. According to guidelines, it is recommended to create special load modes for equipment, mechanisms, and devices in order to perform thermal imaging diagnostics. Furthermore, many modern devices do not allow inspection under load due to their construction characteristics or safety requirements. Therefore, the detection rate of defects using thermography is low.

[0003] Thermocouples, radiation thermometers, and other sensors with dedicated recording devices, or various overheat indicators, are used for automatic, continuous temperature monitoring. Electronic sensors are characterized by measuring the temperature only at the point of contact between the sensor and the device. This makes them incapable of detecting localized defects occurring in specific areas of a large surface, such as interwinding short circuits in transformers or partial discharges in cables or cable joints. In these cases, only a small area (a few square millimeters) of the cable's outer insulation heats up. Such heating cannot be detected, for example, by a thermocouple fixed just a few centimeters from the defect or installed inside the cable. Furthermore, electronic sensors are complex, require a power supply, and are unable to measure the temperature of moving parts or electrical circuits under high voltage.

[0004] Other means of continuous temperature monitoring include chemical or mechanical temperature indicators. These are divided into two types: reversible (they change appearance only when heated and return to their original state upon cooling) and irreversible (they change appearance above a certain temperature and maintain that state even after cooling). An example of a reversible device is the invention described in document US7600912B2 (published March 20, 2007). This is a single- or double-layer sticker whose heat-sensitive element contains a leuco dye and a color former in a binder. When a certain temperature is reached, the binder melts, and the color former reacts with the dye, coloring the label. When the temperature drops, the dye crystallizes and the color returns to its original state. An example of an inorganic reversible temperature indicator is an invention based on a chromium(III) complex described in document RU2561737C1 (published September 12, 2014). The proposed thermochromic material has the ability to reversibly change color when heated above 120°C. A distinctive feature of this type of invention is that it is unable to detect defects other than peak loads, so excessive temperatures must be visually confirmed. This is why these devices are not widely used.

[0005] Unlike reversible indicators, non-reversible indicators can detect and record the fact that a threshold temperature has been exceeded. Furthermore, unlike thermography and reversible indicators, inspection of these stickers can be carried out even while the equipment is under repair, without putting it into full load mode.

[0006] Irreversible overheat indicators can be classified according to their operating principle: indicators based on mechanical destruction of the heat-sensitive element, chemical reactions between components, or phase transitions of the heat-sensitive component are known.

[0007] An example of a temperature indicator based on mechanical destruction is described in the literature [US6176197B1, published November 2, 1998]. According to this, the temperature indicator consists of a closed, transparent, elongated tube in which two differently colored compositions are separated by a polymeric partition. The melting point of the partition is close to the melting point of the compositions. Upon reaching a certain threshold temperature, the partition is destroyed, the compositions melt and mix, and the color of the contents of the tube changes. This invention is characterized by its inability to monitor overheating of the entire surface and its slow activation speed. This is due not only to the complete melting of the indicator compositions and the polymeric membrane separating them, but also to the slow mixing of the liquid phases, as the diffusion process near the melting point is not fast enough. Furthermore, the structural features of this invention make it difficult to create a flexible device that can adhere to the entire surface being controlled.

[0008] A chemical reaction based on etching of a metal substrate that begins when a certain temperature is reached is described in patent EP2288879B1, published June 4, 2008. This indicator changes color from silvery white or mirror-like to colorless and can be used to monitor the temperature of food, medical products, and electrical equipment. The metal and activator layers are applied to a thin film and manufactured as a sticker, making it flexible and easy to attach to a variety of surfaces. Another example of a temperature indicator based on a chemical reaction is described in US6957623B2, published March 9, 2004. In this case, the heat-sensitive material contains a mixture of water, latex, and frost-active microorganisms and is transparent until a threshold temperature is reached. When heated to a predetermined temperature, the latex and frost-active microorganisms interact to produce an opaque material. Among commercially available indicators whose operating principle is based on the occurrence of a chemical reaction, we can highlight the RetomArk model indicator (https: / / www.yAlosindicAtor.com / product / termoindikAtory-kontrol-temperAtury) offered by YALOS Innovation Company LLC. Irreversible thermal indicators based on chemical reactions are characterized by low accuracy. This is because, according to the Arrhenius equation, the rate of progress of the chemical reaction depends not only on temperature but also on time. Therefore, the product may activate even if it is maintained at a temperature slightly below the threshold for a long period of time. On the other hand, the aforementioned standards specify specific threshold temperatures in intervals of 5°C or less, making these devices unsuitable for defect detection. Another characteristic of such devices is that their activation time is highly dependent on temperature. Even if heated to the threshold temperature for a short period of time, the chemical reaction may not be completed, and the indicator's color change may not occur or may be insufficient for detection. Furthermore, because the color change reaction is reversible, some products may return to their original appearance if maintained at low temperatures for a long period of time.

[0009] The most accurate are temperature indicators based on phase transitions, especially the melting of heat-sensitive components. Unlike chemical reactions, the temperature of a phase transition is independent of the duration of the reaction, making these indicators the most accurate and allowing them to maintain their original appearance indefinitely at temperatures just below the threshold.

[0010] Irreversible indicators based on the phase transition of a heat-sensitive component can be manufactured as stickers or paints. The use of temperature-indicating paints and varnishes based on the melting of pigments is described in documents such as CN112322134A (published September 23, 2020), CN111849346A (published July 11, 2020), CN108610694A (published December 9, 2016), SU1765145A1 (acquired October 30, 1989), and SU576334A1 (published May 25, 1976). These paints typically consist of a synthetic resin, filler, and a melting component dispersed in water or a solvent. When heated above a certain temperature, the heat-sensitive component melts, causing the composition to change color due to a change in refractive index. These compositions usually retain or slightly change color after cooling, making visual inspection of overheating easy. Heat-sensitive paints can be used to cover large areas, allowing you to pinpoint the exact location of an overheating event. Another advantage of these indicators is that they can be applied to surfaces of any shape and size.

[0011] However, indicator paint has some characteristics.

[0012] When visually inspecting equipment that does not have a temperature display on the paint, the operator can see that the temperature has been exceeded, but cannot determine the numerical value of the exceeded threshold. This requires special marking. The absence of such a record could lead to misinterpretation.

[0013] When the paint flow temperature exceeds the threshold temperature, the heat-sensitive components melt, causing the paint to lose viscosity and flow down from the surface onto conductive parts of electrical equipment or moving parts of machinery, which can cause accidents such as short circuits, reduced electrical strength, overheating, seizure, and fire.

[0014] The uneven coating of the coating on the surface makes it impossible to measure the temperature accurately, especially on parts with complex surfaces. Areas with a thicker coating take longer to heat up, and the difference between the surface temperature and the phase transition temperature (operating temperature) is greater than in thinner areas.

[0015] Wires made of non-stick materials such as silicone, polyethylene, and fluoropolymers have poor adhesion and are difficult to apply. The large amounts of heat-fusible pigments required for clear visualization of overheating usually reduce the proportion of polymer binder, which reduces the adhesion of the paint, making it easily removable by mechanical impact.

[0016] The operating temperature of paint depends on the chemical coating on the surface. Because paint comes into direct contact with the material to which it is applied (e.g., cable insulation or motor case coating), various substances such as flame retardants and plasticizers can leach into the paint. These substances can form eutectic mixtures with thermally soluble components or affect the phase transition temperature.

[0017] Another feature of the above inventions is their limited ability to operate under low pressure or vacuum conditions. This is due to the sublimation of the main material. References SU867919A1 (published September 30, 1981) and SU401214A1 (published May 8, 1976) describe the operation of the inventions at atmospheric pressure and 10 -4Heat-sensitive compositions have been described for visually and photographically measuring the surface temperature of objects under vacuum down to mmHg. These compositions are mixtures containing salts or esters of higher carboxylic acids, a binder, and ethyl alcohol. The binder is an alcoholic solution of BF-2 or BF-4 adhesive. However, these are proposed only as thermal coatings and suffer from the general drawbacks mentioned above.

[0018] These problems do not exist with special indicator devices (stickers, cable sleeves, clips, etc.), where the hot melt composition is applied in a uniformly thin layer at the factory to a substrate that provides good adhesion and is then coated with a polymer film that protects the hot melt composition from mechanical or chemical influences and prevents it from running off when melted after activation.

[0019] Irreversible heat-sensitive devices can be manufactured in both single-temperature and multi-temperature versions. The advantage of irreversible multi-temperature indicator devices is that they not only indicate the fact that a predetermined temperature has been exceeded, but also numerically identify the maximum surface temperature reached by the monitored component during operation, making it possible to track the progression of defects and compare overheating temperatures between identical components (units of equipment). Single-temperature indicator devices clearly record the exceedance of a specified limit temperature for the monitored electrical equipment or unit of electrical installation, providing timely notification to inspecting personnel of the occurrence of an accident or pre-accident situation, allowing them to quickly address any possible consequences.

[0020] Such indicators typically use higher carboxylic acids and their salts, paraffins, waxes, esters of polyhydric alcohols, transition metal complexes, metal alloys, and other compositions as the heat-sensitive component.

[0021] Currently known thermosensitive devices based on the phase transition of a thermo-fusible component can be classified by the operating principle that achieves the color change: either a change in transparency due to the melting of the thermo-fusible component or the dissolution of the molten dye. Among known inventions involving dyes, thermosensitive materials in which the dye is uniformly dispersed in a solid polymer binder are known (WO2018176266A1, published October 4, 2018). When the material reaches the melting point of the binder, the dye melts and changes color. The polymer binder can be wax, a low-melting polymer, a non-polymeric organic substance (vanillin or triphenylphosphine), or a mixture thereof. Similarly, US6602594B2 (published August 5, 2003) describes an invention in which a granular or powdered dye is mixed with a thermo-fusible substance and diffuses by dispersing or dissolving when a predetermined temperature is reached. The hot-melt components used are fatty acid derivatives, alcohols, ethers, aldehydes, ketones, amines, amides, nitriles, hydrocarbons, thiols, and sulfides. A notable feature of the proposed method is that it does not produce a sufficiently contrasting color change. This is because the dye in the solid binder imparts its color to itself, and in some products, the dye particles aggregate upon cooling, causing the original color to return upon cooling.

[0022] Some inventions are based on the principle that a heat-sensitive material penetrates a substrate, causing the device's color to change. Wax applied to a colored paper substrate becomes transparent upon reaching its melting point, penetrating the paper substrate and revealing its color (US20060011124A1, published July 15, 2004). Another example is a device consisting of an opaque porous membrane and an amorphous polymer or colored composite layer (comprising a polymer binder, a crystalline material, and a dye) applied underneath (US4428321A, published November 16, 1981; WO2019090472A1, published November 7, 2017). As the temperature increases, the heat-sensitive material melts and penetrates the porous membrane, matching the refractive index of the material and the membrane, causing the membrane to become transparent. A characteristic of this type of device is that the material may crystallize within the pores of the membrane or substrate, causing it to lose transparency and resulting in a loss of color display.

[0023] At the technical level, the invention described in WO2018176266A1 (published October 14, 2018) is known. This invention is a thermal indicator composition containing an organic solid material with a melting point above ambient temperature and a dye that dissolves when it comes into contact with the organic solid material and reaches its melting point. The organic solid material exists as a continuous phase, and dye particles are dispersed within it as clusters or crystals. When the device reaches the melting point of the organic solid material, the material melts, dissolving the dye particles and staining the entire material the color of the dye. In some embodiments, the indicator composition is applied to a substrate containing grooves or depressions. When the organic solid material melts and the dye dissolves, not only does the color of the indicator layer change, but the material also penetrates into the grooves and depressions in the substrate, revealing a corresponding pattern. In another embodiment, the device is fabricated by stacking an organic solid material (1-25 μm thick), a dye (0.1-0.5 μm thick), and additional layers that provide the required performance characteristics (adhesion to the surface, protection from external influences, including UV radiation). However, this invention has several drawbacks, including a low contrast in the color change upon reaching the melting point, a low operating accuracy of the indicator composition when the device temperature does not exceed the melting point of the organic material, and the need to select a combination of dye and organic solid material. Furthermore, this document does not describe the extent to which the color change is irreversible when the device is cooled below the melting point of the organic material.

[0024] There are also some commercially available devices that rely on the color change of the heat-melting component itself without the use of additional dyes. These are stickers coated with a layer of heat-sensitive material that melts and changes transparency when a certain temperature is reached, without the molten material penetrating the pores of the substrate. The closest analogues of the proposed inventions are temperature indicator elements manufactured and / or supplied by companies such as LLC Innovative Company YALOS, CJSC NPF Lyuminofor, etc.

[0025] The alleged prototype of the device is a temperature indicator sticker manufactured by NiGK Corporation, a Japanese company (https: / / contents.bownow.jp / files / index / sid_9c257787049cA562bbdA?client_id=d867dc3c-AB2f-4A08-bA5A-32d 9c6B2c5A1&Access_token=&referer=https%3A%2F%2Fwww.nichigi.co.jp%2Fen%2Fen_downloAdform%2Fen_dAtA.html, Catalog dedicated to temperature indicator materials). The patent discloses a number of irreversible indicator stickers (e.g., LE, 3E, 4E, 5E, 8E, F, 1K, 3K, 3R, 5S, and Mini series) with a colored base coated with a heat-sensitive material. High-precision temperature measurement is achieved by utilizing the effect of a change in transparency when a stable, refined pigment reaches its melting point. Visibility is ensured by the appearance of the substrate color. According to the catalog, these indicators are irreversible and will not revert to their original color after activation. The LE, 3E, 4E, 5E, 8E, and F series stickers have a shelf life of five years indoors and three years outdoors. The 1K, 3K, 3R, 5S, and Mini series stickers have a three-year indoor shelf life but are not suitable for outdoor use.

[0026] These indicator stickers have the following characteristics that significantly limit their widespread use:

[0027] Insufficient sticker lifespan. It is extremely important that the shelf life of the device that records overtemperature conditions is equal to or exceeds the lifespan of the equipment in which it is installed, since some units of electrical installations may not be accessible during operation and the heat-sensitive element must be installed during assembly or repair work.

[0028] The device must be mounted on a flat surface. Mounting it on a curved surface or corner may reduce the device's accuracy. This is exactly what the manufacturer warns on page 2 of the catalog. This indicates that the sticker's substrate and heat-sensitive material layer are not flexible enough, which can lead to cracking or peeling if mounted on a surface with a complex shape. Uneven heating of the heat-sensitive material also reduces the accuracy of the thermal recording.

[0029] Unreliable actuation. When used at high temperatures, especially with stickers with a threshold temperature above 130°C, the material may lose its opacity. It may also partially regain its opacity after actuation. This is as the manufacturer points out on page 2 of their catalogue.

[0030] These characteristics are due to the following:

[0031] To ensure maximum opacity of the heat-sensitive layer and initially render the substrate color invisible, the heat-sensitive material must have high light absorption and scattering properties. These properties are achieved by materials with numerous phase boundaries. When light strikes these boundaries, it is scattered in various directions. In known state-of-the-art devices, crystals of the heat-melting component are dispersed in a binder to create large phase boundaries, creating a "solid-in-solid" system. When light strikes a material with this structure, it is reflected and scattered by the crystal's many facets, preventing it from reaching the colored substrate and making it invisible. The material becomes opaque. Upon melting, the solid crystals change phase, becoming liquid and forming spherical droplets. This reduces the total area of ​​the phase boundaries, making the material transparent. Upon further cooling, the heat-melting component solidifies, remaining spherical, and the material remains transparent.

[0032] However, over time, the following processes can occur that can significantly degrade the performance of the material:

[0033] On the crystal surface, a solid solution with the polymer binder can be formed by the binder molecules penetrating the crystal lattice of the heat-sensitive component, smoothing the crystal boundaries and reducing the area of ​​the phase interface, which results in an increase in the transparency of the material and an increased risk of false overheating detection.

[0034] Recrystallization can occur due to partial dissolution of the crystals in the binder, which leads to coarsening of the crystals, a decrease in the number of phase boundaries, and a decrease in opacity.

[0035] When a solid solution forms at the phase interface, it can create a eutectic mixture with a lower melting point than either component alone, which can change the operating temperature of the device and reduce the accuracy of overtemperature detection.

[0036] The above process is significantly accelerated, especially in high-threshold temperature stickers, when they are used at temperatures slightly below the threshold. As a result, the lifetime of these devices is significantly shorter than the values ​​declared in prototypes, as the manufacturers point out.

[0037] The need for a relatively thick application of heat-sensitive ingredients can lead to the following problems:

[0038] Insufficient flexibility of the prototype device.

[0039] Excessive heat-sensitive composition running down onto the controlled surface is unacceptable in the operation of electrical installations.

[0040] Uneven heating throughout the material and large differences between the surface temperature of the controlled object and the temperature of the material's surface, which is particularly evident when recording short-term overheating.

[0041] As a result, the heat-sensitive components in the lower layer near the heated surface may melt and change color, while the surface layer remains intact, compromising the accuracy of recording over-temperatures and reducing the overall safety of the equipment's operation.

[0042] Furthermore, upon reaching a threshold temperature, the crystals of the thermosensitive component melt and form spherical droplets. If these are heated for a long period of time above the device's activation temperature, they may diffuse into the polymer binder and aggregate to form larger droplets. When the activated device cools, these large spherical droplets solidify. The total area of ​​the phase interfaces is significantly reduced compared to that of the original material. This allows the material to remain transparent after cooling. However, if the device records a short heating period, the thermosensitive component crystals melt, but due to the slow diffusion process in solids and highly viscous liquids, the diffusion is not complete, and the droplets do not aggregate or increase in size. As a result, when the device cools, numerous small spherical droplets remain in the material. The surface area of ​​these droplets, and therefore the total area of ​​the phase interfaces, is only slightly reduced compared to that of the original material before heating. This can lead to color inversion, reduced color change contrast, and false negatives, especially when cooled or held for a long period of time below the melting point of the thermosensitive component.

[0043] Therefore, there is a need for a device that visually records overheating above a threshold temperature, that is reliable, fast to operate, and safe throughout its lifespan, and how it is manufactured.

[0044] Terms and definitions used in the present invention

[0045] "Opaque to at least part of the visible light" refers to a material that does not transmit all or part of the light in the visible light range (380-760 nm).

[0046] "Microstructure" refers to the spatial arrangement of a material's particles or individual phases, ranging in size from 1 to 100 μm. It reflects the shape and orientation of the particles that make up the material. Unlike chemical structures and nanoparticles, microstructure determines only the physical, optical, and mechanical properties of a material and does not affect the chemical properties of the substances that make up the microstructure. "Irreversible change in microstructure" refers to an irreversible change in the physical, optical, or mechanical properties of a material relative to its original state, as well as a change in its microstructure (the spatial arrangement, size, and shape of the particles or individual phases). This includes the complete fusion of particles to form a single phase.

[0047] "Continuous solid phase" refers to the structure of a material containing solid particles of any shape. Each particle has at least one point, face, or edge in contact with and connected to an adjacent particle, so that each element of the solid phase can be connected to other elements by a curve that is entirely contained within that phase. In this case, the microstructure is not a continuous solid phase only if no such curve can be formed. Depending on the shape and size of the solid particles, a continuous solid phase can have a cellular, granular, fibrous, crystalline, or scale-like structure.

[0048] "Continuous gas phase" refers to the voids that exist within a solid. These voids are interconnected through pores or channels.

[0049] "Flexible substrate" refers to a material that can be deformed by external force and retains its functional properties after returning to its original shape.

[0050] "Threshold Temperature" or "Threshold" (T) refers to the temperature at which a thermosensitive material undergoes a sudden change in appearance, such as a local color change resulting in an increase in the transparency of the layer. The present invention has an accuracy of up to 5°C in recording the fact that the threshold temperature has been exceeded.

[0051] The term "accuracy of recording threshold temperature exceedance" means the following: 1. There will be no change in the transparency of the corresponding heat-sensitive material or in the appearance of the device until the device reaches a temperature equal to the threshold temperature of the corresponding heat-sensitive material minus the nominal accuracy value. 2. When the temperature reaches or exceeds the threshold temperature of the corresponding heat-sensitive material, the corresponding heat-sensitive material will become transparent, and the appearance of the device will be different from its original state. 3. The exact value of the phase transition of the heat-sensitive component is within the nominal range and is not additionally set. The recording accuracy of exceeding the threshold temperature defined in this invention group is 5°C.

[0052] The term "covering power" refers to the material's ability to obscure the color of the surface to which it is applied. When applied to the boundary between black and white, "covering power" refers to the material's ability to reduce the contrast between specified areas of the surface until the visual difference is completely eliminated. In this invention, the covering power (D) of a heat-sensitive material is measured using a method similar to GOST 8784-75 (Section 1, "Visual Measurement of Covering Power"). The heat-sensitive material is applied to a pre-weighed glass plate according to the following instructions and allowed to dry to a constant mass. The weighing is performed with the required accuracy. The number of layers of heat-sensitive material is determined individually for each experiment. The mass of the heat-sensitive material is calculated as the difference between the mass of the device and the mass of the glass plate. The glass plate coated with the heat-sensitive material is placed on a contrast plate or checkerboard and observed under diffused sunlight to see whether the white and black areas show through. Coverage is considered to be achieved when the difference in brightness between the black and white areas of the glass plate is completely eliminated and is calculated as the mass of the heat-sensitive material (in grams) divided by the area (in units) of heat-sensitive material applied to the glass plate.

[0053] "Apparent density" is the mass of a dry material divided by its total volume, including voids within the material (in accordance with GOST 2409-95). In the present invention, apparent density is determined as follows: A uniform section containing a heat-sensitive element is cut out of the device. The mass and volume are measured with the required accuracy. The volume is measured, for example, by measuring linear dimensions with the required accuracy. The device is then separated into layers, a layer of heat-sensitive material is mechanically removed, and the mass and volume of the remaining elements are measured. The mass and volume of the heat-sensitive material are calculated as the difference between before and after removal. Apparent density is obtained by dividing the mass of the heat-sensitive material by its total volume.

[0054] The term "porosity" refers to the volume of the gas phase within a heat-sensitive material divided by the total volume of the heat-sensitive material, or the area of ​​the gas phase in a cross-section of the heat-sensitive material divided by the total area. In this group of inventions, porosity is determined by one of the following methods. The first method involves analyzing the surface of the heat-sensitive material using a scanning electron microscope. For this purpose, a uniform section containing the heat-sensitive material is cut from the finished product. The protective layer is then removed to preserve the heat-sensitive material. The section of the heat-sensitive material from which the protective layer has been removed is analyzed using a scanning electron microscope, and the total surface area of ​​the solid particles in the sample is calculated. The area of ​​the gas phase is obtained by subtracting the total surface area of ​​the solid particles from the total area of ​​the analyzed area, and the porosity is calculated by dividing this by the area of ​​the analyzed area. 5 Seven locations on the material are measured, and the average porosity value is calculated. The second method involves using X-ray microtomography. Sample preparation is similar to the first method. A portion of heat-sensitive material of known volume is analyzed with a laboratory digital X-ray tomography device to calculate the proportion of gas phase within the sample. 5 Seven locations of the material are measured and the average porosity, expressed as a percentage, is calculated.

[0055] The term "blind principle" refers to a specific microstructure of the heat-sensitive material, meaning that the solid particles are mainly scale-like and oriented parallel or perpendicular to the substrate on which the heat-sensitive material is applied. "Open blind principle" means that the solid particles are mainly oriented perpendicular to the substrate layer on which the heat-sensitive material is applied and the outer layer of the protective coating. Such a microstructure does not offer the ability to mask the color of the substrate. "Closed blind principle" means that the solid particles are mainly oriented parallel to the substrate layer and the outer layer of the protective coating. Such a microstructure of the heat-sensitive material better masks the color of the substrate at the same layer thickness.

[0056] In this group, we use the term "vitrification" to refer to the process in which a uniform layer of one thermodynamic phase forms around particles of another thermodynamic phase.

[0057] "Phase transition" refers to the transition of a substance from one thermodynamic phase to another as a result of a change in external conditions. In this group of inventions, a phase transition is melting or other process in which a substance transitions from a solid to a fluid state when heated above a certain temperature.

[0058] The term "complete isolation from the ambient environment" refers to the creation of a protective layer that ensures the device's airtightness, prevents contact of the heat-sensitive material with the ambient environment, and protects the device from adverse external influences such as moisture, precipitation, splashes, industrial pollutants, mechanical influences, etc. A "partial isolation from the ambient environment" layer also protects the device from adverse external influences, but is not airtight and maintains atmospheric pressure in the gas phase within the volume of the heat-sensitive material. Summary of the Invention

[0059] The object of the present invention is to improve the operational safety of various equipment by creating a device for reliably, reliably and safely recording short-term and long-term overheating above at least one threshold temperature, and by providing several embodiments of a method for manufacturing the same.

[0060] Most specifically, the present inventions were created to solve the following problems: 1. Ensure that the temperature of a local area or entire surface exceeds at least one threshold temperature. 2. Reliably detect overheating recorded under actual operating conditions of devices and equipment, even over a long period after operation. 3. To record short-term overheating and detect defects occurring during short circuit currents and impulse overvoltages. 4. To ensure the overall safety of operation of various equipment with devices that visually record overtemperature conditions.

[0061] The technical results of the present inventions are: increased reliability and accuracy of visual recording of the fact that at least one threshold temperature has been exceeded; non-reversion of the heat-sensitive material; increased speed of operation of the heat-sensitive material (especially during short-term peak loads or abnormal operation of the controlled parts of the equipment); increased safety of the controlled equipment and the recording device itself during the entire operating period.

[0062] In the first embodiment, the desired technical result is achieved by using a layered over-temperature visual recording device and a heat-sensitive material with a special microstructure. Overall, the device can be described as having the following layered structure:

[0063] A substrate that is partially opaque to visible light and has a numerical marking on its surface that indicates at least one threshold temperature.

[0064] A heat-sensitive material that is opaque to a portion of visible light and is applied to specific areas of a substrate, whose microstructure contains particles of solid organic matter and voids filled with a gas phase.

[0065] A transparent protective layer that partially or completely covers the surface of a device.

[0066] The device is designed such that, upon reaching a specified threshold temperature, the microstructure of the heat-sensitive material is destroyed, the particles of the solid organic material fuse together, the percentage of voids decreases, and transparency increases, resulting in an irreversible appearance change that reveals the color of the substrate.

[0067] The use of void-containing heat-sensitive materials extends service life and improves the reliability of overheat detection compared to conventional technologies. This is because the agglomeration of solid particles through the gas phase is prevented, eliminating the possibility of the material returning to its original state. When void-containing heat-sensitive materials melt, the original microstructure of the material changes irreversibly, increasing its apparent density and decreasing the void content. This occurs because the particles of the solid organic material fuse, reducing the area of ​​the solid-gas phase interface, releasing the gas in the voids to the surface, and separating the gas and non-gas layers. As a result, after cooling, the solid organic material recrystallizes without voids, increasing the material's transparency to a portion of visible light compared to its original state, creating a visual effect in which the device's appearance changes with high contrast. This enables highly accurate overtemperature detection.

[0068] The device of the present invention therefore features a hybrid operating principle that combines not only the melting of the heat-sensitive material but also the irreversible microstructural changes due to phase separation, fusion of solid organic particles, and a reduction in the void ratio, which prevent the material from returning to its original state after cooling. This change remains irreversible even after prolonged low-temperature storage or temperature fluctuations.

[0069] Studies of heat-sensitive materials with different void percentages have shown that increasing the void percentage significantly reduces the thickness of the heat-sensitive material layer required to mask the color of the substrate compared to materials without voids (see Examples 11-12 on pages 50-55 of this specification). This is due to multiple refractions of light at the solid-gas interface. In the devices of the present invention, the coverage of at least one heat-sensitive material is preferably 50 g / cm² or less.

[0070] The resulting high coverage allows for devices with minimal thickness, minimizing the amount of heat required to achieve a color change. This allows for rapid and uniform heating and melting of the material, increasing the activation speed of the heat-sensitive material and enabling overheat detection with minimal overtemperature or shortest duration above the threshold temperature, especially under short-term peak loads or abnormal operating conditions. Furthermore, the device's minimal thickness does not affect operability, safety, or heat dissipation from the controlled object, while maintaining adhesion to complex surfaces and preventing cracking or delamination from the substrate.

[0071] In addition, reducing the thickness of the heat-sensitive material layer can prevent excessive flow of the material when melting, avoiding short circuits, reduced electrical strength, overheating, burning and other accidents.

[0072] In various embodiments of the present invention, the pressure of the gas phase within the voids of the heat-sensitive material is equal to or less than atmospheric pressure. When using a device with a pressure less than atmospheric pressure, the force that atmospheric pressure exerts on the material through the transparent protective layer further increases the rate of irreversible microstructural change and, therefore, the actuation speed of the heat-sensitive material.

[0073] The protective layer also provides protection from external factors such as moisture, precipitation, splashes, industrial pollutants, and mechanical influences. Preferably, the transparent protective layer covering the device is made of an elastic polymer material. This not only protects against the environment and prevents the heat-sensitive material from flowing or dripping after melting, but also maintains the device's airtightness, ensuring that the gas pressure in the cavity before heating is below atmospheric pressure. The elasticity of the protective layer also allows the device to maintain its functional properties even when placed on surfaces with complex shapes.

[0074] Due to the structural characteristics of the thermosensitive layer, its microstructure contains a large amount of gas, which can lead to the formation of bubbles beneath the protective layer when the threshold temperature is exceeded. If the pressure of the gas phase within the thermosensitive material's voids is equal to atmospheric pressure and the thermosensitive material is hermetically covered with a protective layer, the microstructure of the thermosensitive material is destroyed, resulting in the separation of the gas and non-gas phases. As this process progresses during heating, the volume of the bubbles increases due to thermal expansion. As the device cools, the volume of the gas phase decreases, causing the size of the bubbles beneath the protective layer to shrink. These processes explain the need for elastic materials to maintain the integrity of the device during use over a wide temperature range. To eliminate bubbles that form when the threshold temperature is exceeded, some embodiments of the present invention propose creating a gap between the transparent protective layer and the substrate or drilling tiny holes in the protective layer. This provides an escape route for the gas released during operation while protecting the thermosensitive material from external influences.

[0075] In existing embodiments where the gas pressure in the void is subatmospheric and the protective layer is airtight, no gas bubbles may form under the protective layer after cooling above a threshold temperature because the thermal expansion of the gas is offset by the initial subatmospheric pressure of the gas phase in the void.

[0076] Preferably, the microstructure of the at least one heat-sensitive material initially has particles of the solid organic substance oriented parallel to the surfaces of the substrate and the protective layer. In certain cases, the solid organic substance may be present in the form of flakes, fibers, aggregates, etc.

[0077] Preferably, the void fraction of the at least one heat-sensitive material is reduced by at least two times compared to its initial state after being heated above a corresponding threshold temperature, thereby further improving the contrast of the color change of the device upon exceeding the threshold temperature, and the apparent density of the at least one heat-sensitive material is increased by 2.5 to 10 times compared to its initial state after being heated above a corresponding threshold temperature.

[0078] The microstructural features of the heat-sensitive material described above result in a higher number of phase boundaries in the initial state compared to the prior art, maximizing the contrast of the color change when the specified threshold temperature is reached, thus enhancing the technical achievement of the present invention.

[0079] In some embodiments, the solid organic material undergoes a phase transition that irreversibly increases the transparency of the thermosensitive material when a threshold temperature, within 5°C of the temperature displayed on the device, is reached. In addition, the present invention preferably uses organic compounds containing one or more aliphatic hydrocarbon chains to ensure proper particle packing of the solid organic material. This is because such organic materials have a crystalline packing structure in which extended structural fragments of linear hydrocarbons are oriented parallel to each other, forming primarily flat particles such as flakes or fibers (AI KitAigorodskii, MoleculAr CrystAls, Moscow, 1971 / AI KitAigorodskii, MoleculAr CrystAls, Moscow / Moscow: NAukA1971). This crystalline packing structure causes anisotropy in the solid organic material and, therefore, anisotropy in the microstructure of the thermosensitive material, resulting in different material properties in directions parallel to and perpendicular to the surfaces of the substrate and protective layer. The anisotropy in the microstructure of the thermosensitive material affects the material's strength against bending and mechanical stress. The material remains intact even when a force is applied in a direction almost perpendicular to the substrate surface (AI KitAigorodskii, Organic Crystal Chemistry, Moscow: USSR Academy of Sciences, 1955).

[0080] In certain embodiments, the solid organic substance of the heat-sensitive material is selected from the following group: aliphatic fatty acids containing 13 or more carbon atoms, aliphatic fatty acid salts containing 12 or more carbon atoms, alkanes containing 20 or more carbon atoms, dialkylphosphinic acids containing 16 or more carbon atoms, aliphatic fatty acid amides containing 3 or more carbon atoms, aliphatic fatty acid anhydrides containing 22 or more carbon atoms, aliphatic alcohols containing 16 or more carbon atoms, aliphatic amines containing 17 or more carbon atoms, aliphatic fatty acid nitriles containing 20 or more carbon atoms, or mixtures thereof. The melting point of a particular solid organic substance determines the threshold temperature of the corresponding heat-sensitive device. Therefore, the organic substance is selected so that its melting point matches the threshold temperature of the device with a predetermined accuracy. The number of carbon atoms in each class of organic substance is determined based on the specific practical problem to be solved by the device of the present invention (e.g., the type of equipment, the required heating temperature step, the surface area to be heated, etc.).

[0081] Another factor determining the choice of solid organic substance for the heat-sensitive material is the commercial availability of the substance. Therefore, using organic substances that are difficult to obtain on an industrial or semi-industrial scale may be commercially disadvantageous, even if they meet other requirements. Preferably, the solid organic substances used are aliphatic fatty acids containing 22 or fewer carbon atoms, aliphatic fatty acid salts containing 66 or fewer carbon atoms, alkanes containing 40 or fewer carbon atoms, dialkylphosphinic acids containing 20 or fewer carbon atoms, aliphatic fatty acid amides containing 22 or fewer carbon atoms, aliphatic fatty acid anhydrides containing 26 or fewer carbon atoms, aliphatic alcohols containing 32 or fewer carbon atoms, aliphatic amines containing 22 or fewer carbon atoms, and aliphatic fatty acid nitriles containing 22 or fewer carbon atoms.

[0082] In particular cases, the solid organic substance of the heat-sensitive material is selected from the following group: palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearyl alcohol, cetyl alcohol, dispersed polyethylene, saturated fatty acid salts of rare earth metals (especially lanthanum, yttrium, ytterbium, scandium).

[0083] In certain cases, the microstructure of at least one heat-sensitive material additionally contains a polymer binder that is transparent to a portion of visible light and has a phase transition temperature higher than that of the solid organic substance. In this case, the heat-sensitive material has a "solid-solid-gas" phase interface, and the microstructure of the material irreversibly changes upon melting. This causes gas contained within the voids to escape to the material's surface, separating the gas and non-gas phases and reducing the contact area between the solid phase and the voids. In other words, the area of ​​the phase interface decreases. As the gas filling the voids escapes to the surface, diffusion processes in solids and viscous liquids are faster than in "solid-solid" systems. This not only accelerates the change in transparency of the heat-sensitive material, but also ensures that the change is irreversible after cooling. Furthermore, the irreversible change in the heat-sensitive material's microstructure may be accompanied by the formation of a new thermodynamic phase (e.g., a solid solution). Preferably, the polymer binder is present in the heat-sensitive material in an amount of 1-30% by weight. In certain cases, the polymer binder coats each structural particle of the solid organic material, "vitrifying" them. The binder is selected so that the particles of the solid organic material are wetted but not dissolved in the polymer binder. This allows the gases from which the heat-sensitive material is formed to be additionally trapped and distributed between the "vitrified" particles of the solid organic material when the particles, crystals, fibers, flakes, or aggregates are "vitrified." This feature allows for a microstructure with an increased number of phase interfaces, enhancing the technical achievement of the present invention.

[0084] In particular, the transparent polymer binder may be phenol formaldehyde resin, butyl methacrylate resin, melamine formaldehyde resin, polyvinyl butyral, polybutyl methacrylate, polyisobutyl methacrylate, polybutyl acrylate, phenoxy resin, polystyrene-acrylic emulsion, polyolefin, polystyrene, polyacrylate, polyethersulfone, polyethylene, polypropylene, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene, polyethersulfone, polyisoprene, polypropylene, polybutadiene, polyisobutyl acrylate, polyisobutyl acrylate, polyvinyl meth ... The polymer may be selected from isobutylene, polyvinyl acetate, polymethacrylate, ethyl cellulose, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polycaprolactone, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, polyvinylidene fluoride, polyester, polyester resin, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, nitrocellulose, carboxymethyl cellulose, gelatin, agar, casein, gum arabic, polyvinyl alcohol, polyethylene oxide, or a mixture thereof.

[0085] The devices can be realized as various types of products designed to be securely fastened to and adhere to the surface of the equipment they control (including industrial, domestic and energy applications).

[0086] In a preferred embodiment of the present invention, the device can be realized as a sticker including an insulating layer, an adhesive layer, an elastic substrate opaque to a portion of visible light (made of a halogen-containing polymer, less than 1 mm thick, and having a dielectric strength of 5 kV / mm or more), a heat-sensitive material having a thickness of 800 μm or less applied to a specific portion of the substrate, and a transparent protective layer. The heat-sensitive material is designed to irreversibly change its transparency in less than 5 seconds when it reaches a corresponding threshold temperature indicated on the sticker.

[0087] By using a halogen-containing polymer substrate, such as polyvinyl chloride, this device can be used to visually record excessive surface temperatures on conductive parts of electrical equipment. This is due to its insulating and flame-resistant properties. Using an elastic substrate less than 1 mm thick allows the device to be tightly attached to surfaces with complex shapes, including conductive parts of electrical equipment. Furthermore, by using a substrate less than 1 mm thick and a heat-sensitive material layer less than 800 μm thick, the heat-sensitive material can heat up quickly in the event of short-term overheating, completely changing color from opaque to transparent within 5 seconds. This also ensures sufficient heat dissipation for air cooling of the device during operation. The heat-sensitive material's activation speed of less than 5 seconds allows it to detect short-term abnormal overheating caused by starting currents, short-circuit currents, motor overload starting, cold runs, switching, and other processes when the corresponding threshold temperature is exceeded. Furthermore, the device's thinness allows for precise localized overheating on the controlled surface, even when using stickers with a large heat-sensitive layer, due to the minimal heat dissipation in the plane of the substrate and heat-sensitive material.

[0088] In another embodiment of the present invention, the device can be realized as a hollow elastic tube (Chemblack) or a tube with a longitudinal cut (clip). These are attached to the surface of an electric wire, which acts as a substrate that is opaque to a portion of visible light (made of a halogen-containing polymer, less than 1 mm thick, with a dielectric strength of 5 kV / mm or more). A heat-sensitive material with a thickness of 800 μm or less is applied to a specific portion of the substrate's surface and is covered with a transparent protective layer. The heat-sensitive material is designed to irreversibly change its transparency in less than 5 seconds when it reaches the corresponding threshold temperature marked on the tube.

[0089] Unlike stickers, clips and chemracks are convenient for attaching to thin electrical wires inside electrical panels in buildings and facilities.

[0090] The substrate can be light-reflective or fluorescent to increase the visibility of the device itself and its operating status, and therefore further improve the operational safety of the installation.

[0091] In other embodiments, the surface area of ​​the substrate covered with at least one heat-sensitive material may be 100 mm or more in order to more accurately detect localized overheating on the surface of the electrical equipment.

[0092] In the event of localized heating, only areas of the heat-sensitive material that exceed the corresponding threshold temperature will change transparency, allowing for the recording of spot-like overheating.

[0093] The technical result is also achieved by embodiments of a method for manufacturing a device for visually recording an overtemperature exceeding at least one threshold temperature. The disclosed embodiments are not limiting and other methods may be used to obtain heat-sensitive materials with the microstructures disclosed herein.

[0094] In a first embodiment, a method for manufacturing a device for visually recording temperature exceedance above at least one threshold temperature comprises the steps of: -Applying to specific areas of an opaque substrate one or more suspensions of particles of solid organic substances dispersed in a liquid phase, the boiling point of which is less than 180°C and the solubility of the particles of solid organic substances in the liquid phase does not exceed 10g / kg. The liquid phase is removed from the applied suspension layer to form a heat-sensitive material that is opaque to a portion of visible light and whose microstructure contains particles of solid organic matter and voids filled with a gas phase. -The surface of the workpiece is covered with a transparent protective layer.

[0095] At least one of the above steps is carried out at subatmospheric pressure.

[0096] In this embodiment, at least one step uses reduced pressure (subatmospheric pressure) to rapidly remove the liquid phase, causing it to boil, further foaming the material and increasing the number of voids. Also, if one step uses reduced pressure, the other step removes the liquid phase from the applied suspension layer at atmospheric pressure.

[0097] In a preferred embodiment, reduced pressure is used prior to application of a transparent protective layer or during layer-by-layer application of a suspension of solid organic particles dispersed in a liquid phase after removal of the liquid phase from each layer. The reduced pressure in the device fabrication method is preferably 1 to 650 mmHg. The selected pressure and the time the device workpiece is held under this pressure depend on the boiling point of the liquid phase, the amount of liquid phase used to prepare the suspension, and the properties of the solid organic substance.

[0098] A vacuum can also be applied immediately after applying each layer of the liquid suspension. In this case, a microstructure containing particles of solid organic matter and voids filled with gas is formed layer by layer. In another embodiment of this method, a vacuum is applied during the process of removing the liquid phase from the required number of suspension layers. In this case, the liquid phase is naturally released from the entire material, forming more unstructured voids. In a third embodiment, the surface of the workpiece is covered with a transparent protective layer under vacuum. If an airtight protective layer is used, this keeps the pressure within the voids of the heat-sensitive material in the final product below atmospheric pressure. In addition, creating a vacuum during this process removes any residual liquid phase trapped in the heat-sensitive material. The rapid evaporation of the residual liquid phase during the vacuum further foams the material and increases the number of voids.

[0099] Reduced pressure can be applied during any two or all three steps of device fabrication to create the desired microstructure of the heat-sensitive material, depending on the nature of the solid organic material, the liquid phase used, and the concentration of the solid organic material in suspension.

[0100] When fabricating devices using this method, particles of solid organic material can be formed as flakes, fibers, grains, crystals, or aggregates thereof.

[0101] In a second embodiment, a method for manufacturing a device for visually recording an overtemperature condition exceeding at least one threshold temperature includes at least three cycles. Each cycle includes applying a suspension of solid organic particles dispersed in a liquid phase to a specific portion of an opaque substrate, removing the liquid phase from the applied suspension layer, and then covering the surface of the substrate with a transparent protective layer. The boiling point of the liquid phase is less than 180°C, and the application of the suspension of solid organic particles dispersed in a liquid phase is selected from the group consisting of screen printing, flexographic printing, tampon printing, and silk screen printing. This results in a heat-sensitive material having a microstructure in which the particles of the solid organic substance are oriented approximately parallel to the surface of the substrate.

[0102] In this embodiment, after applying the first layer of suspension, the workpiece is dried at room temperature to a constant weight, and then the layer-by-layer application and removal of the liquid phase are repeated at least three times to achieve the required coating thickness. In certain cases, screen printing, flexographic printing, tampon printing, or silk screen printing is used to apply a suspension of solid organic particles dispersed in a liquid phase to specific areas of an opaque substrate. Repeated application and removal of the liquid phase results in a well-ordered arrangement of the solid organic particles on the substrate. Natural removal of the liquid phase from the suspension layer at room temperature causes the flakes to slowly settle and pack under thermodynamically favorable conditions. This results in the formation of a heat-sensitive material layer with a microstructure in which the solid organic particles are aligned approximately parallel to the substrate surface. To achieve the required coverage, the application and removal of the liquid phase are repeated at least three times to obtain a heat-sensitive material that is opaque to a portion of visible light.

[0103] When fabricating devices using this method, particles of solid organic materials are formed primarily as flakes, fibers, crystals, or aggregates thereof, whose linear dimensions exceed their thickness.

[0104] In embodiments of the device manufacturing method of the present invention, the thickness of the heat sensitive material is 800 μm or less, preferably 450 μm or less, and most preferably 150 μm or less.

[0105] Preferably, the device fabrication method uses a suspension of 2-3 μm particles of solid organic material dispersed in a liquid phase. The density difference between the liquid phase and the solid organic material is preferably less than 0.2 g / μm. For this purpose, the liquid phase is selected from, but is not limited to, isopropanol, water, methanol, 1-propanol, isobutanol, monomethyl ether ethylene glycol, 1-butanol, acetonitrile, acetic acid, hexane, heptane, 1,1,1-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropanol, dimethylformamide, ethanol, butyl acetate, acetone, toluene, or mixtures thereof.

[0106] The density difference between the solvent and solid organic particles is an important factor affecting particle settling speed and properties. When the density difference is large (0.2 g / L or more), the solid organic particles settle out of suspension rapidly, randomly oriented relative to the substrate surface, forming vertical and horizontal structures. In this case, the substrate is visible through the horizontal structures, so the vertical alignment achieves the required coverage even with the same layer thickness. When the densities are similar or the density difference is less than 0.2 g / L, the solid organic particles settle slowly, forming a well-ordered microstructure that is primarily vertically aligned relative to the substrate surface.

[0107] In order for the devices of the present invention to be used safely in the energy sector (e.g., for visually recording excessive surface temperatures of conductive parts in electrical installations), embodiments of the method for manufacturing the device use halogen-containing polymer substrates, such as polyvinyl chloride, because they are flame-retardant and insulating.

[0108] Embodiments of the device fabrication method of the present invention may use solid organic materials selected from the classes of materials described on page 33 of this specification.

[0109] The invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0110] [Figure 1] Various embodiments of a device for visually recording temperature exceedance above at least one threshold temperature: 1a is a tube (clip) designed to be attached to a wire with a longitudinal notch for attachment to an electrical wire, using one heat-sensitive material; 1b is an elastic hollow tube (chemblack) for attachment to an electrical wire, using three different heat-sensitive materials; and 1c is a sticker using four different heat-sensitive materials. [Figure 2] Layered structures of devices for visually recording temperature exceedance: 2a, structure with an airtight transparent protective layer when one threshold temperature is exceeded; 2b, structure with a transparent protective layer with a gap between the protective layer and the substrate when one to three different threshold temperatures are exceeded; and 2c, structure with a transparent protective layer with a micro-hole when one to four different threshold temperatures are exceeded. [Figure 3] A device for visually recording overtemperature exceeding at least one threshold temperature. 3a shows the initial state of a sticker using one heat-sensitive material. 3b shows a sticker using one heat-sensitive material after activation (after exceeding the threshold temperature). 3c shows the initial state of a sticker using three different heat-sensitive materials. 3d and 3e show partial activation states after the first (3d) and second (3e) heat-sensitive materials exceed the threshold temperature. 3f shows the fully activated state after the third heat-sensitive material exceeds the threshold temperature. 3g shows the initial state of a sticker using a light-reflective or fluorescent substrate and four different heat-sensitive materials. 3h shows the fully activated state after the fourth heat-sensitive material exceeds the threshold temperature, showing a visual color change from "white to black." 3i shows the layered structure of a device using four different heat-sensitive materials using a light-reflective or fluorescent substrate, with a black paint coating on the heat-sensitive material area and a transparent protective layer with micro-holes. [Figure 4]Microstructure of the heat-sensitive material: 4a: flakes and aggregates (without binder) before actuation, 4b: flakes and aggregates (without binder) after actuation, 4c: flakes and aggregates (with binder) before actuation, 4d: flakes and aggregates (with binder) after actuation, 4e: fibers and aggregates (without binder) before actuation, 4f: fibers and aggregates (without binder) after actuation. [Figure 5] A device that visually records exceeding a threshold temperature during localized overheating. 5A shows the initial state of the device. 5b shows the partially activated state after a portion of the controlled surface exceeds the threshold temperature, where only the overheated area changes transparency, while the unheated area remains opaque. DETAILED DESCRIPTION OF THE INVENTION

[0111] Figure 1 shows various embodiments of devices for visually recording temperature exceedance above at least one threshold temperature, including a tube (clip) with a longitudinal notch for attachment to an electrical wire (1a), a resilient hollow tube (Chemblack) for attachment to an electrical wire with one heat-sensitive material 1 (1b), or a sticker (1c) with four different heat-sensitive materials 1 and a display 2 showing the numerical value of the recorded temperature.

[0112] Figure 2 shows the layered structure of a device for visually recording temperature exceedance above one threshold temperature (2a). It includes a flexible substrate 3 with a thickness d, a heat-sensitive material 1 applied thereon with a thickness D, and a transparent protective layer 4 that adheres to the substrate and material to maintain the device's airtightness and subatmospheric pressure. The layered structure of a device for visually recording temperature exceedance above one to three different threshold temperatures (2b) includes a flexible substrate 3 with a heat-sensitive material 1 applied thereon, and a transparent protective layer 4 that adheres to the substrate and material and has a gap 5a between the protective layer and the substrate. The layered structure of a device for visually recording temperature exceedance above one to four different threshold temperatures (2c) includes a flexible substrate 3 with a heat-sensitive material 1 applied thereon, and a transparent protective layer 4 that adheres to the substrate and material and has micro-holes 5b on its surface.

[0113] Figure 3 shows a device for visually recording temperature exceedances above a threshold temperature as a sticker. It includes an initial state (3a) before heating and a state (3b) after heating above the threshold temperature. It includes a flexible substrate 3, a heat-sensitive material 1 applied thereto, and an indicia 2 indicating the numerical threshold temperature to be recorded. It also shows a device for visually recording temperature exceedances above one to three different threshold temperatures in its initial state (3c), after the first threshold temperature has been exceeded (3d), after the second threshold temperature has been exceeded (3e), and after the third threshold temperature has been exceeded (3f). It includes a flexible substrate 3, multiple heat-sensitive materials 1 applied thereto, and an indicia 2 indicating the numerical threshold temperature for each heat-sensitive material. It also shows a device for visually recording temperature exceedances above one to four different threshold temperatures in its initial state (3g), after the fourth threshold temperature has been exceeded (3h), and its layered structure (3i). It includes a flexible substrate 6 with light reflectivity or fluorescence, a heat-sensitive material 1 applied thereon, a display 2 showing the numerical value of the threshold temperature of each heat-sensitive material, black paint 7 applied to the area under the heat-sensitive material, and a transparent protective layer 4 that is in close contact with the substrate and material and has microscopic holes 5b on its surface.

[0114] Figure 4 shows the microstructure of binder-free heat-sensitive material 1. Before heating (4a), particles 8 formed as flakes and aggregates, and voids 9 are visible. After heating above the threshold temperature (4b), the void fraction decreases, the apparent density increases, and the particles fuse together, losing their original shape. The microstructure of binder-containing material 1 is also shown. Before heating (4c), particles 8 formed as flakes and aggregates, and voids 9 are visible. After heating above the threshold temperature (4d), the void fraction decreases, the apparent density increases, and the particles fuse together, losing their original shape. The microstructure of binder-free heat-sensitive material 1 is also shown. Before heating (4e), particles 8 formed as fibers and aggregates, and voids 9 are visible. After heating above the threshold temperature (4f), the void fraction decreases, the apparent density increases, and the particles fuse together, losing their original shape.

[0115] Figure 5 shows a device for visually recording the exceedance of a threshold temperature during localized overheating. It includes a flexible substrate 3 with a heat-sensitive material 1 applied to it. Shown is the state before heating (5a) and the state after a portion of the controlled surface has exceeded the threshold temperature (5b). As a result, only the heated area 11 changes transparency, while the rest of the heat-sensitive material 1 maintains its initial state.

[0116] Implementation of the invention

[0117] Preparation of heat-sensitive materials.

[0118] The solid organic substance of the at least one heat-sensitive material is selected from the following classes of organic substances: aliphatic fatty acids containing 13 or more carbon atoms, aliphatic fatty acid salts containing 12 or more carbon atoms, alkanes containing 20 or more carbon atoms, dialkylphosphinic acids containing 16 or more carbon atoms, aliphatic fatty acid amides containing 3 or more carbon atoms, aliphatic fatty acid anhydrides containing 22 or more carbon atoms, aliphatic alcohols containing 16 or more carbon atoms, aliphatic amines containing 17 or more carbon atoms, aliphatic fatty acid nitriles containing 20 or more carbon atoms, or mixtures thereof.

[0119] Preferably, the aliphatic fatty acids used as the solid organic substances contain 22 or less carbon atoms, the aliphatic fatty acid salts contain 66 or less carbon atoms, the alkanes contain 40 or less carbon atoms, the dialkylphosphinic acids contain 20 or less carbon atoms, the aliphatic fatty acid amides contain 22 or less carbon atoms, the aliphatic fatty acid anhydrides contain 26 or less carbon atoms, the aliphatic alcohols contain 32 or less carbon atoms, the aliphatic amines contain 22 or less carbon atoms, and the aliphatic fatty acid nitriles contain 22 or less carbon atoms.

[0120] In certain embodiments, the solid organic substance of the at least one heat-sensitive material is selected from the following substances: yttrium caproate, yttrium behenate, yttrium undecanoate, yttrium laurate, tridecane yttrium laurate, tridecane yttrium pentadecanoate, yttrium tridecanoate, yttrium pentadecanoate, yttrium palmitate, ytterbium caprylate, lanthanum palmitate, lanthanum nonadecanoate, caproic acid Lanthanum, erbium undecanoate, zinc nonadecanoate, zinc palmitate, zinc caproate, zinc myristate, zinc stearate, cadmium laurate, cadmium lauromyristate, lead caprate, lead stearate, lead laurate, lead lauromyristate, copper stearate, calcium stearate, lithium stearate, stearic acid, lauric acid, docosanoic acid, eicosanoic acid, crotonic acid, arachidic acid, myristic acid, palmitic acid, adipic acid Acid, Octanoic Acid, Capric Acid, Tricosanoic Acid, Tetratriacontanoic Acid, 2,3-Dimethylnonanoic Acid, Brassic Acid, 2-Methyl-2-dodecenoic Acid, Eleostearic Acid, Behenolic Acid, Behenic Acid, Oleamide, Stearamide, Lauramide, Erucamide, Capric Acid Amide, Myristic Acid Amide, Caprylic Acid Amide, Palmitic Acid Anilide, Salicylic Acid Anilide, Caproic Acid Beta-Naphthylamide, Enanthic Acid Phenylhydrazide, Hexylamide, Octacosyl Amide, N-methylheptacosylamide, salicylamide, hexadecanol, eucamide, 1-docosonol, trilaurin, tricosylamine, dioctadecylamine, N,N-dimethyloctylamine, dioctylphosphinic acid, tritriacontane, tetracosane, stearyl alcohol, cetyl alcohol, dispersed polyethylene, stearic acid chloride anhydride, palmitic acid anhydride, stearic acid and acetic anhydride, lauric anhydride, or mixtures thereof.

[0121] In various embodiments, the melting point of the solid organic substance of each thermally sensitive material is in the range of 50-210°C, and the threshold temperature of at least one thermally sensitive material is selected from 50°C, 55°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, and 150°C.

[0122] To produce the heat-sensitive material, the solid organic substance is ground to a size of 2-3 m using a ball mill, and then water or an organic solvent with a boiling point below 180°C is added sequentially, and the resulting suspension is stirred. During this process, it is preferable to periodically expose the mixture to air and disperse it until the density of the mixture becomes constant. The liquid phase is preferably water or an organic solvent, and the solubility of the solid organic substance does not exceed 10 g / kg.

[0123] In a preferred embodiment, the liquid phase is added in a proportion of 50-90 vol.%.

[0124] The density difference between the liquid phase and the solid organic substance is preferably less than 0.2 g / mol.To this end, the liquid phase is selected from, but is not limited to, isopropanol, water, methanol, 1-propanol, isobutanol, monomethyl ether ethylene glycol, 1-butanol, acetonitrile, acetic acid, hexane, heptane, 1,1,1-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropanol, dimethylformamide, ethanol, butyl acetate, water, acetone, toluene, or mixtures thereof.

[0125] The heat-sensitive material obtained by this manufacturing method consists of two continuous phases: a solid phase and a gas phase.

[0126] The resulting thermosensitive material is initially opaque to a portion of visible light, but when heated above a corresponding threshold temperature, it undergoes an irreversible microstructural change in which the particles of the solid organic substance fuse, the void fraction decreases, the transparency increases, and the color of the substrate is revealed. Even after cooling, the transparency of the thermosensitive material does not return to its initial value.

[0127] Depending on the nature of the solid organic material, the resulting particles of solid organic material may be formed as particles, crystals, fibers, flakes, or aggregates thereof.

[0128] In some embodiments, the pulverized solid organic material is suspended in a solution of a binder that is transparent to a portion of visible light. In a preferred embodiment, the binder is present in the resulting heat-sensitive material at 1-30% by weight, providing a "vitrifying" effect for the particles of the solid organic material.

[0129] In this case, the transparent polymer binder is phenol formaldehyde resin, butyl methacrylate resin, melamine formaldehyde resin, polyvinyl butyral, polybutyl methacrylate, polyisobutyl methacrylate, polybutyl acrylate, phenoxy resin, polystyrene-acrylic emulsion, polyolefin, polystyrene, polyacrylate, polyethersulfone, polyethylene, polypropylene, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene, polyethersulfone, polyisoprene, polypropylene, polybutadiene, polyisobutylene, poly The polymer may be selected from, but is not limited to, polyvinyl acetate, polymethacrylate, ethyl cellulose, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polycaprolactone, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, polyvinylidene fluoride, polyester, polyester resin, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, nitrocellulose, carboxymethyl cellulose, gelatin, agar, casein, gum arabic, polyvinyl alcohol, polyethylene oxide, or mixtures thereof.

[0130] In this case, the heat-sensitive material has a "solid-solid-gas" phase boundary, and the microstructure of the material changes irreversibly upon melting, causing the gas contained in the voids to be released to the material surface, separating the gas and non-gas phases and reducing the number of voids.

[0131] The suspensions, with or without binder, are used for application immediately after preparation.

[0132] Device substrate selection

[0133] The device of the present invention can be realized as a sticker, clip, chemblack, or other device that is securely fastened and adheres tightly to the surface of the equipment being controlled.

[0134] The device has the following layered structure: a substrate that is opaque to a portion of visible light, at least one heat-sensitive material applied to the surface of the substrate, and a transparent protective layer that partially or completely shields the heat-sensitive material from the environment.

[0135] In the case of clips and chemblack, the substrate that is opaque to part of the visible light is the outer surface of a tube with longitudinal cuts or the outer surface of an elastic hollow cylinder.

[0136] The thickness of the device substrate is typically less than 1 mm, ensuring activation speeds of less than 5 seconds when each heat-sensitive material is heated above its corresponding threshold temperature.

[0137] Substrates for various types of devices can be selected from the following materials: PVC films such as OraJet 3106SG or 3951, 3981RA polyurethane film, 3M polyester film 7874 E or WHITEV TC 50 / RC20 / HD70WH self-adhesive paper film, ORALITE 5500 methacrylic film, etc. When using halogen-containing polymer substrates (especially PVC), it is preferable that the device have a dielectric strength of at least 5kV / mm, which is suitable for use in the energy sector.

[0138] In some embodiments, the surface of the substrate may be printed with a design containing graphic, numerical, or textual information for marking the phases and nodes of electrical equipment, and the substrate itself may be light reflective or fluorescent, improving the visibility of the device itself and its operating status, further enhancing the operational safety of the equipment.

[0139] To enhance the contrast of the color change, the substrate in the area of ​​the at least one heat-sensitive material is painted, for example, black, where the heat-sensitive material is preferably white, and activation of the at least one heat-sensitive material results in a visual change from "white to black."

[0140] Fabrication of a device that visually records temperature exceedances above at least one threshold temperature.

[0141] Typically, the device manufacturing process involves applying one or more suspensions of solid organic particles dispersed in a liquid phase to specific areas of an opaque substrate, removing the liquid phase from the applied suspension layer, and covering the surface of the workpiece with a transparent protective layer.

[0142] To obtain a microstructure that, upon reaching a threshold temperature, undergoes an irreversible change in appearance, whereby the particles of solid organic materials fuse together, the proportion of voids decreases, the transparency increases, and the color of the substrate is revealed, the following methods can be used: - At least one of the above steps (applying a suspension in which particles of solid organic material are dispersed in a liquid phase, removing the liquid phase from the applied suspension layer, and covering the surface of the workpiece with a transparent protective layer) is carried out under subatmospheric pressure. - A process of applying a suspension in which particles of a solid organic substance are dispersed in a liquid phase and then removing the liquid phase from the applied suspension layer is repeated at least three times. In this process, the suspension is applied by a method such as screen printing, flexographic printing, tampon printing, or silk screen printing, to obtain a heat-sensitive material with a microstructure in which the particles of the solid organic substance are oriented approximately parallel to the substrate surface.

[0143] Removal of the liquid phase from the applied layer of the suspension of particulate organic particles in the liquid phase, or removal from each layer individually, can be carried out either at subatmospheric pressure or at atmospheric pressure, depending on the selected method of manufacturing the device.

[0144] In certain cases, subatmospheric pressure can be used both immediately after applying each layer of the solid organic suspension in a liquid phase and during the drying (i.e., liquid phase removal) stage of the required number of applied layers of the solid organic suspension in a liquid phase. In this case, the liquid phase is spontaneously released from the material volume (either from each layer sequentially or from the entire material volume), creating more non-structural voids. In other words, the process of using subatmospheric pressure involves a rapid removal of the liquid phase, similar to boiling, which results in further foaming of the material and an increase in the number of voids. Furthermore, subatmospheric pressure can be used in the step of coating with a sealed protective layer. This not only prevents the formation of bubbles on the surface of the protective layer during operation of the device, but also ensures the removal of the residual liquid phase blocked by the heat-sensitive material, further foaming of the material, and an increase in the number of voids. In this case, after the last layer is applied, the device is dried for at least one hour, preferably at a temperature of (20±2)°C, by selecting a mode for removing the liquid phase from the applied suspension layer, and only then is the device coated with the protective layer using subatmospheric pressure.

[0145] The application of subatmospheric pressure can be performed during any two stages of device fabrication, and during all three stages of device fabrication, and also results in a heat-sensitive material with a desired microstructure.

[0146] The claimed device can also be produced by layer-by-layer application of a suspension of solid organic matter in a liquid phase. In this case, after application of at least one heat-sensitive material, the device is dried by selecting a mode of removing the liquid phase from the applied suspension layer, preferably in an air atmosphere at a temperature of (20±2)°C for 10 minutes, and then the lamination procedure is repeated until the desired coating thickness is achieved. The formation of a microstructure containing solid organic particles and voids filled with a gas phase occurs layer-by-layer. Layer-by-layer application, preferably at room temperature with a dwell time between approaches, provides the necessary ordering of the solid fused particles when placed on the device. If the solid soluble particles are flakes, they are preferably arranged "overlapping" longitudinally on the flexible base of the device to achieve a coating with minimal layer thickness. In this case, the flakes are arranged like closed blinds, and it is sufficient for only a thin layer of flakes to overlap the base color (the "closed blinds principle"). The natural removal of the liquid phase from a layer of suspension applied at room temperature results in the flakes settling slowly and packing in a thermodynamically favorable manner. By applying this technique to the preparation of heat-sensitive materials, the preferential formation of a continuous solid phase of solid organic matter is observed, while the gas-filled voids form a continuous gas phase. When the liquid phase is forcibly removed from a layer of suspension by heating or blowing air, the kinetic process of solvent evaporation takes precedence over the thermodynamic ordering of the particles of the solid organic matter. As a result, the flakes form a horizontal structure rather than a vertical one (the "open blinds principle"), and the base becomes visible at the same layer thickness.

[0147] Such ordering can also be achieved by using dilute suspensions of solid fusible particles in a liquid phase (dilution greater than 50%), since a larger volume allows the flakes to orient in the desired way and settle in an orderly manner, as opposed to using more concentrated suspensions. In addition, a higher dilution rate prolongs the process of natural evaporation of the liquid phase, during which the scales also become arranged according to the closed louver principle. Another factor that influences the rate and nature of precipitation of solid organic particles is the relative density difference between the solvent and the solid soluble particles. At higher density differences (0.2 g / cm),3 (or more), solid organic particles settle out of suspension quickly according to the open-loop principle. 3 At a density difference of less than 0.05, the particles of solid organic matter settle slowly and the necessary ordered material microstructure forms, conforming to the principle of closed loop.

[0148] Thus, by adhering to the open louver principle in forming the microstructure of the heat-sensitive material, it is possible to obtain a material whose initial microstructure has a preferential orientation of the solid particles parallel to the surfaces of the base and protective coating.

[0149] The application of the layer of suspension of solid organic matter in a liquid phase is preferably carried out by a method selected from screen printing, flexographic printing, pad printing, silk screen printing.

[0150] In flexographic printing, the slurry is captured by an anilox roller and transferred to the raised areas of a relief printing plate, which is then covered with a thin layer of slurry and transferred to the substrate. At the same time, the formation of an ordered array of particles, primarily parallel to the surface, begins during the anilox capture stage. As the layer of suspension thins during transfer to the raised areas of the printing plate, further ordering of the particles is achieved. The ordering process is completed when the suspension is transferred to the base, providing an array of solid organic particles according to the "closed blind" principle. In pad printing, a pad or roller is used to transfer a solid organic suspension into a liquid phase, on which the solid organic particles are formed according to the "closed shutter" principle. Application to the substrate completes the ordering process, achieving the desired microstructure of the heat-sensitive material.

[0151] Silk screen and screen printing are achieved using a screen printing plate or matrix, which is a fine mesh made of polyester, polyamide, or metal monofilament. In this process, a suspension of solid organic matter in a liquid phase is forced through the mesh onto the substrate by a doctor, thereby depositing the solid organic matter particles parallel to the substrate surface. Repeated rolling of the doctor over the mesh allows for preferential orientation of all the solid organic matter particles according to the "closed louver" principle.

[0152] The above-described effects are applicable to device embodiments in which the microstructure of the heat-sensitive material is represented by organic solids in which the particles are primarily in the form of flakes, crystals, or fibers, i.e., particles having a linear dimension greater than their thickness. The formation of aggregates (conglomerates) of individual particles (flakes, crystals, fibers) of solid organic matter may be observed.

[0153] For thermal materials containing solid organic matter, binder, and voids, the thermal material is prepared using a suspension of finely dispersed solid organic matter in a liquid binder solution. When the liquid phase evaporates, the binder precipitates onto the solid organic matter particles, coating their surfaces with a thin, uniform layer. This process "glazes" both the individual particles of solid organic matter and the resulting aggregates of particles.

[0154] The front area of ​​the base of the device is sealed with a polyethylene film so that the at least one heat-sensitive material is not exposed when applying the suspension of solid organic particles in a liquid phase. A layer of the at least one suspension of solid organic particles in a liquid phase is applied uniformly to the uncovered area of ​​the substrate by one of the techniques described above.

[0155] In an advantageous embodiment, the thickness of the layer of heat-sensitive material is 800 μm or less, preferably 450 μm or less, and most preferably 150 μm or less. Using this thickness of the at least one heat-sensitive material layer ensures that each of the at least one heat-sensitive material is triggered in less than 5 seconds when heated above its corresponding threshold temperature. This is due to the fact that such a material layer thickness, together with the thickness of the device base, allows the heat-sensitive material to be heated during short-term overheating during peak load periods and completely transformed into a melt with an "opaque-to-transparent" color transition within 5 seconds, while also providing the necessary heat dissipation during air cooling of the operating device.

[0156] In a preferred embodiment, the surface area of ​​the opaque substrate coated with one or more heat-sensitive materials is at least 100 mm 2 is.

[0157] In some embodiments of the present invention, the uncovered areas of the substrate are first printed with black ink or lettering, particularly including threshold temperature values ​​or other graphic, numerical, or textual information, using a solvent dye, and then a layer of heat-sensitive material is applied. Furthermore, in advantageous embodiments of the present invention, at least 70% of the base area is covered with black paint. When at least a portion of the substrate is painted black, at least one heat-sensitive material is initially white, and when heated above its corresponding threshold temperature, a visual color transition occurs on at least a portion of the device surface from white to black.

[0158] The number of heat-sensitive materials is not limited by an upper limit and depends on the practical challenges to be met when using the claimed device (type of device, required step of determined heating temperature, area of ​​surface to be tested for heating, etc.). In a specific embodiment, three or four different heat-sensitive materials are applied to the front surface of the substrate. In this case, the heat-sensitive materials can be applied to both the border and non-border portions of the front surface of the substrate.

[0159] For example, for a device made of three different heat-sensitive materials, the threshold temperatures can be 50°C, 55°C, and 60°C. That is, the first heat-sensitive material changes transparency at 50°C, the second heat-sensitive material changes transparency at 55°C, and the third heat-sensitive material changes transparency at 60°C, all with a 5°C accuracy. In other embodiments, the threshold temperatures are 50°C, 60°C, and 70°C, or 50°C, 70°C, and 80°C. C, or 60°C, 70°C, 80°C, or 60°C, 80°C, 100°C, or 60°C, 90°C, 110°C, or 70°C, 80°C, 90°C, or 70°C, 90°C, 110°C, or 70°C, 100°C, 120°C, or 70°C, 110°C, 130°C, or 80°C, 90°C, 100°C, or 80°C, 120°C, 140°C, or 80°C, 120°C, 150°C, or 90°C, 100°C, 110°C, or 90°C, 110°C, 130°C, or 100°C, 120°C, 140°C.

[0160] For a device made of four different heat-sensitive materials, the threshold temperatures can be 50°C, 55°C, 60°C, 70°C, or 50°C, 60°C, 70°C, 80°C, or 50°C, 70°C, 90°C, 110°C, or 60°C, 70°C, 80°C, 90°C, or 60°C, 70°C, 80°C, 100°C, or 60°C, 80°C, 90°C, 110°C, or 70°C, 80°C, 90°C, 100°C, or 70°C, 90°C, 100°C, 120°C, or 70°C, 90°C, 110°C, 130°C, or 80°C, 90°C, 100°C, 110°C, or 80°C, 100°C, 120°C, 140°C, or 80°C, 100°C, 120°C, 150°C.

[0161] As a final preparation step, the device was coated with a transparent protective layer. In some embodiments of the present invention, a gap may be provided between the protective layer and the substrate, or the transparent protective layer may be provided with micro-holes to allow the gas phase to escape from the device after a detectable temperature has been exceeded. Preferably, the transparent protective layer is selected from a transparent elastomeric polymer. In another embodiment of the present invention, the device blank is held at subatmospheric pressure and then coated with a transparent protective layer to seal the device and maintain the pressure in the gas void at subatmospheric pressure. For this reason, in this embodiment of the present invention, a transparent elastomeric polymer film is also used as a protective layer.

[0162] Principle of operation of the device.

[0163] The device, comprising a flexible base 3 with one or more heat-sensitive materials 1 applied thereon and a transparent protective layer 4, is placed on the surface on which temperature control is to be provided, ensuring a tight fit of the device with the help of fastening elements provided by the design of the device. In a more preferred embodiment, the device is a sticker that is attached to the surface by means of an adhesive layer from which the insulating layer has first been removed. In the other two versions (clip and video camera), the operating principle of the device is similar to that of a sticker.

[0164] Since the devices for visually registering over-temperatures used in the power industry are mainly in the form of stickers, the working principle of the device will be further explained on the example of a sticker.

[0165] The device is in the form of a sticker with a sheet of heat-sensitive material applied to it. Initially and until heated to a threshold temperature, the applied heat-sensitive material 1 is opaque to at least a portion of visible light, and in a preferred embodiment of the present invention, is white. The heat-sensitive material 1 remains opaque to at least a portion of visible light until the entire surface of the device, or a portion thereof, beneath the heat-sensitive material 1 is heated to the threshold temperature, thereby maintaining the device's original appearance. When the surface is heated above the heat-sensitive material's threshold temperature, irreversible destruction of the heat-sensitive material's microstructure occurs across the entire surface of the heat-sensitive material 1 or primarily in the heated region 11, respectively, resulting in the fusion of solid organic particles 8, a reduction in the proportion of voids 9, and a resulting increase in transparency. This increases the apparent density of the material. The heat-sensitive material 1 with its altered microstructure is transparent and exhibits the color of the substrate 3 beneath it or the color of the ink 7 applied to the substrate in the region of the heat-sensitive material. Even if the monitor surface is subsequently cooled, the temperature-sensitive material 1 or part thereof 11 remains transparent, and the appearance of the device does not return to its original state. This allows visual recording of temperatures exceeding the temperature threshold both at the moment of overheating and after a long period of time.

[0166] The devices have different threshold temperatures T 1...n When the device has multiple (n) zones with heat-sensitive materials 1 each having a threshold temperature T1, all of the heat-sensitive materials 1 remain opaque until the surface of the device located under the heat-sensitive materials 1 is heated to a threshold temperature T1, thereby maintaining the original appearance of the device. When the threshold temperature T1 is reached, the solid organic particles of the first heat-sensitive material 1 having the threshold temperature T1 lose their original shape and begin to fuse together, and the microstructure begins to irreversibly decompose with a decrease in the proportion of voids, resulting in an increase in the transparency of each heat-sensitive material 1 and the appearance of the color of the substrate 3 underneath. At the same time, the activation temperature T 2...n The other zones with the heat-sensitive material 1 having a temperature T1 retain their microstructure and therefore their original appearance. 2...n Further increasing the temperature to a threshold temperature T 2...nIn this case, the maximum temperature of the device surface is the temperature of the heat-sensitive material T n If the temperature is lower than at least one of the threshold temperatures of the thermally sensitive material T n The corresponding zones of the heat-sensitive material 1 retain their microstructure and initial opacity. During subsequent cooling of the device surface, the areas of the heat-sensitive material 1 where the microstructure has changed remain transparent, and the appearance of the device does not revert to its original state. The threshold temperature T of the heat-sensitive material zones p When the device surface is repeatedly heated up to a temperature of 1000 K, irreversible destruction of the microstructure of the corresponding heat-sensitive material 1 with an "opaque-transparent" transition and a change in the color of the underlying base 3 occurs.

[0167] When the controlled surface is spot heated, transparent zones 11 are formed only in the areas of the temperature sensitive material that are heated above a threshold temperature, while the remaining unheated areas of the material remain opaque.

[0168] The threshold temperature 2 value can be applied to the front surface of the base 3. In special cases, the threshold temperature value can be applied to areas without the heat-sensitive material 1. However, next to them or on the base 3 beneath the heat-sensitive material 1, in the latter case, when the temperature exceeds the corresponding threshold temperature, an irreversible change occurs in the microstructure of the corresponding heat-sensitive material 1, after which the color of the base 3 and the threshold temperature 2 value are displayed. In a specific embodiment, the base is black and the heat-sensitive material is white in its initial opaque state. When the temperature exceeds the corresponding threshold temperature, the appearance of the device changes to a maximum contrast of "black-white," further ensuring the visibility of the triggered device and facilitating visual detection. A similar purpose is achieved by an embodiment of the device in which the base has a color other than black and black ink is applied to the area beneath the heat-sensitive material 1, which is initially white. In this case, too, a color transition from white to black is observed when the device is triggered.

[0169] For devices hermetically sealed with an elastic transparent protective layer 4 at atmospheric pressure, the microstructure of the heat-sensitive material 1 is destroyed, resulting in the stratification of gas and non-gaseous media, resulting in the formation of bubbles on the surface of the protective layer 4 at the moment of activation. These bubbles then decrease as the device cools. When using a device in which the protective layer 4 is sealed and the pressure in the cavity 9 of the heat-sensitive material 1 is subatmospheric, the initial subatmospheric gas pressure in the cavity 9, which occurs during the application of the protective layer 4 to obtain a device blank, compensates for the thermal expansion of the gas released when the microstructure of the heat-sensitive material 1 is destroyed. In other embodiments of the device to prevent bubble formation when the threshold temperature is exceeded, a gap 5A may be formed between the transparent protective layer and the substrate, or microholes 5b may be formed in the protective layer to allow the gas released during activation to escape.

[0170] A variant of the device in which the heat-sensitive material 1 consists of solid organic particles 8, voids 9, and a binder 10 operates in a similar manner. When the temperature exceeds a corresponding threshold, the fusion of the "glazed" particles 8 with the binder 10 occurs, accompanied by the release of the gas phase and the separation of the gaseous and non-gas phases, resulting in the irreversible destruction of the microstructure of the heat-sensitive material 1, a decrease in the proportion of voids 9, and consequently an increase in the transparency of the material.

[0171] Thus, all embodiments of the device have an operating principle based on the irreversible destruction of the microstructure of the heat-sensitive material 1, which is accompanied by the fusion of particles of the solid organic matter 8, a reduction in the proportion of voids 9, and consequently an increase in the transparency of the material and a change in the appearance of the device, which does not return to its original state even when the device cools down.

[0172] This allows visual inspection of the device to reliably and accurately record the fact that the temperature of the entire surface or a localized portion thereof has exceeded at least one temperature threshold.

[0173] Below are preferred embodiments of the claimed device, which are illustrative and in no way limit the scope of the claimed legal protection.

[0174] example

[0175] 1. Obtaining a suspension of solid organic matter in a liquid phase The solid organic matter was crushed to a particle size of 2-3 μm, and the liquid phase was added and stirred, periodically exposing the mixture to air to disperse it until the density of the mixture became constant. The resulting liquid-phase suspension of each solid organic matter was used for spraying immediately after receipt.

[0176] 2. Obtain a suspension of solid organic matter in a liquid phase using a binder. The solid organic matter was ground to a particle size of 2-3 microns, and the liquid binder solution was added. The mixture was stirred with periodic aeration until the density of the mixture became constant. The resulting liquid suspension of each solid organic matter was used for spraying immediately after receipt.

[0177] 3. A method of applying a suspension of solid organic material in a liquid phase to a substrate, applying subatmospheric pressure after the application of each layer. The front surface of the substrate, where the heat-sensitive material must not be exposed, was sealed with a polyethylene film. A layer of the suspension of solid organic matter in a liquid phase obtained according to Example 1 or 2 was applied to the uncoated area of ​​the base by a roller, and the resulting layer was held at a pressure of 10,300 mmHg for at least 1 minute, thereby partially or completely removing the liquid phase. The application and drying procedure was then repeated several times until the desired thickness and required covering power of the heat-sensitive material layer were obtained, after which the protective film was removed and the device was obtained at atmospheric pressure.

[0178] 4. A method in which a suspension of solid organic matter in a liquid phase is applied to a substrate at subatmospheric pressure after the entire layer has been applied. The front surface of the substrate was sealed with a polyethylene film where the heat-sensitive material should not be exposed. Several layers of a suspension of solid organic matter in a liquid phase, obtained according to Examples 1 or 2, were successively applied to the uncoated areas of the substrate using a roller, without allowing the layers to dry between applications, until the desired thickness and covering power of the layer of heat-sensitive material was obtained. The resulting blank was incubated at a pressure of 1 to 150 mmHg for at least 10 minutes, after which the liquid phase was partially or completely removed. The protective film was then removed, and the resulting device was coated with a transparent polymer protective layer at atmospheric pressure.

[0179] 5. A method in which a suspension of solid organic matter in a liquid phase is applied to a substrate while applying subatmospheric pressure to coat it with a protective layer. The front surface of the substrate, where the heat-sensitive material should not be exposed, was sealed with polyethylene film. Several layers of the suspension of solid organic matter in a liquid phase obtained according to Examples 1 or 2 were successively applied to the uncoated areas of the substrate with a roller until the desired thickness and covering power of the heat-sensitive material layer was obtained. Each layer was dried in an air atmosphere for at least 10 minutes before applying the next layer, thereby partially or completely removing the liquid phase. After applying the last layer, the resulting blank was held at atmospheric pressure for at least 1 hour, thereby removing the liquid phase from the top layer and any residual liquid phase from the previous layer. The protective film was then removed, and the resulting device was coated with a transparent polymer protective layer at a pressure of 200-650 mmHg, thereby completely removing the residual liquid phase and forming additional subatmospheric pressure in the void formed when the protective layer was applied.

[0180] 6. A method in which a suspension of solid organic matter in a liquid phase is applied to a substrate at a pressure below atmospheric pressure, after which the entire layer is coated and then covered with a protective layer. The front surface of the substrate, where the heat-sensitive material should not be exposed, was sealed with polyethylene film. Several layers of the suspension of solid organic matter in a liquid phase obtained according to Examples 1 or 2 were successively applied to the uncoated areas of the substrate using a roller, without allowing the layers to dry between applications, until the desired thickness and covering power of the heat-sensitive material layer was achieved. The resulting blank was incubated at a pressure of 1 to 300 mmHg for at least 10 minutes, resulting in partial or complete removal of the liquid phase. The protective film was then removed, and the resulting device was coated with a transparent polymer protective layer at a pressure of 200 to 650 mmHg, resulting in complete removal of the liquid phase and further subatmospheric pressure during the coating of the protective layer into the resulting void.

[0181] 7. A method in which a suspension of solid organic matter in a liquid phase is applied to a substrate using subatmospheric pressure in all three stages. The front surface of the substrate, where the heat-sensitive material should not be exposed, was sealed with polyethylene film. A single layer of the suspension of solid organic matter in a liquid phase obtained according to Examples 1 or 2 was applied to the uncoated area of ​​the substrate using a roller. The resulting layer was held at a pressure of 10-300 mmHg for at least 1 minute, thereby partially or completely removing the liquid phase. The application and drying procedure was then repeated several times until the desired thickness and required covering power of the heat-sensitive material layer were obtained. The resulting blank was then held at a pressure of 30-200 mmHg for at least 10 minutes, thereby completely removing the residual liquid phase. The protective film was then removed, and the resulting device was covered with a transparent polymer protective layer at a pressure of 200-650 mmHg, thereby completely removing the liquid phase and filling the resulting cavity with the protective layer, and further subatmospheric pressure was created.

[0182] 8. A method of applying a suspension of solid organic substances in a liquid phase to a substrate by pad printing The front surface of the substrate, where the thermal material should not be exposed, was sealed with polyethylene film. A cotton swab larger than the area where the thermal material was applied was dipped into the suspension for 1 second, and excess suspension was drained off. A layer of the suspension of solid organic matter in liquid phase obtained according to Examples 1 or 2 was applied to the uncoated area of ​​the substrate with a cotton swab. The resulting layer was held at atmospheric pressure for at least 10 minutes, thereby partially or completely removing the liquid phase. The application and drying procedure was repeated several times until the desired thickness and required covering power of the thermal material layer were obtained. The resulting blank was then dried at atmospheric pressure for at least 1 hour. After the remaining liquid phase was completely removed, the protective film was removed, and the resulting device was coated with a transparent polymer protective layer.

[0183] 9. A method of applying a liquid suspension of solid organic matter to a substrate by flexographic printing The front surface of the substrate, where the thermal material should not be exposed, was sealed with polyethylene film. After treating the anilox roller with the slurry, the slurry was transferred from the anilox to a relief printing plate with raised areas larger than the area where the thermal material was to be applied. A layer of a suspension of solid organic matter in a liquid phase obtained according to Examples 1 or 2 was applied to the uncoated areas of the substrate using the relief printing plate. The resulting layer was incubated at atmospheric pressure for at least 10 minutes, thereby partially or completely removing the liquid phase. The application and drying procedure was then repeated several times until the desired thickness and covering power of the thermal material layer were achieved. The resulting blank was then dried at atmospheric pressure for at least 1 hour to completely remove the remaining liquid phase, after which the protective film was removed and the resulting device was coated with a transparent polymer protective layer.

[0184] 10. A method of applying a suspension of solid organic substances in a liquid phase to a substrate by screen printing A stencil mold with a fine mesh size corresponding to the dimensions of the area where the thermal material was to be applied was fixed to the front of the substrate. A suspension of solid organic matter in a liquid phase, obtained according to Examples 1 or 2, was evenly spread onto the stencil mold using a doctor blade. The resulting layer was incubated at atmospheric pressure for at least 10 minutes, and after partial or complete removal of the liquid phase, the application and drying process was repeated several times until the desired number of layers of thermal material was obtained. The resulting blank was then dried at atmospheric pressure for at least 1 hour. After complete removal of the remaining liquid phase, the protective film was removed, and the resulting device was coated with a transparent polymer protective layer.

[0185] 11. Measurement of the covering power of the materials obtained by the methods claimed in this group of inventions The solid organic substances used were 100 g of an alkane substance (tetracosane), an aliphatic acid (eicosanoic acid), and an aliphatic acid salt (lanthanum caprate), 100 g of isopropanol as the liquid phase, and 100 g of a 3% solution of phenol-formaldehyde resin in isopropanol as the binder. The resulting liquid-phase suspensions of each solid organic substance were used for spraying immediately after receipt.

[0186] To measure the covering power, pre-weighed glass plates were used as substrates. Suspensions of tetracosane and eicosanoic acid in isopropanol obtained separately according to Example 1 were applied to the glass plates according to the methods described in Examples 3, 4, 8, and 10, except for the step of applying a protective layer. Suspensions of phenol-formaldehyde resin and lanthanum caproate in isopropanol obtained according to Example 2 were applied to the glass plates according to the methods described in Examples 3, 4, 8, and 10, except for the step of applying a protective layer. For the samples obtained according to Examples 3 and 4, the number of layers of the corresponding suspension of solid organic matter in the liquid phase was 1, 3, 5, 7, 10, 15, and 20, and for the samples obtained according to Examples 8 and 10, the number of layers was 3, 5, 7, 10, 15, and 20. For each sample, the average layer thickness of the applied thermal material was measured to the nearest 1 μm, and the mass to the nearest 0.001 g. The resulting plate with thermal material was placed on a contrast plate and observed under diffused daylight to see whether the white and black areas were translucent. The test results are summarized in Tables 1 and 2.

[0187] Testing the covering power of the materials obtained by the methods claimed in this group of inventions

[0188] [Table 1-1]

[0189] Testing the covering power of the materials obtained by the methods claimed in this group of inventions

[0190] [Table 1-2]

[0191] Testing the covering power of the materials obtained by the methods claimed in this group of inventions

[0192] [Table 2]

[0193] During testing, it has been found that the covering power of a thermally sensitive material by any of the selected classes of solid organic matter applied by any of the methods described above is achieved when the number of layers of thermally sensitive material is 3 or more and the thickness of the thermally sensitive material is 30 microns or more.

[0194] 12. Measurement of the covering power of materials according to prior art Solids (100 g) of alkane class (tetracosane), aliphatic acid (eicosanoic acid), and aliphatic acid salt (lanthanum caprate) were milled in a ball mill for 30 hours to a particle size of 2-3 μm, after which 100 g of isopropanol was added and stirred for an additional 10 hours. In contrast to Examples 1-2, the mixture did not disperse. The resulting suspensions of each heat-sensitive material were used for coating immediately upon receipt.

[0195] To measure the covering power, pre-weighed glass plates were used as substrates. The front surface of each plate, not in contact with the thermal material, was sealed with polyethylene film. The uncovered area of ​​each plate was coated with a single layer of slurry using a roller. The first plate received one layer of slurry, the second plate received five layers, the third plate received ten layers, the fourth plate received fifteen layers, and the fifth plate received twenty layers. Each layer was applied sequentially, with no intermediate drying between layers. After the final layer of thermal material suspension was applied, the plates were air-dried at room temperature to a constant weight. The average layer thickness of the applied thermal material was measured to the nearest 1 μm, and the mass to the nearest 0.001 g. The resulting thermal material-coated plates were then placed on a contrast plate and observed for translucency of the white and black areas under diffused daylight. The test results are summarized in Table 3.

[0196] Coverage testing of prior art materials

[0197] [Table 3]

[0198] Tests have shown that the covering power of the thermal material with the selected class of solids is achieved when the number of layers of thermal material is 20 and the thickness of the thermal material is 2100 μm or more.

[0199] Example 13-30. Manufacturing a specific device. 13. A suspension of tetracosane (100 g) with a phase transition temperature of 50°C and 100 g of isopropanol was prepared according to Example 1. This slurry was applied to OraJet 3951 black PVC film using a pressure of 10 mmHg and the method described in Example 3 to form an adhesive layer with fire resistance and electrical strength of at least 5 kV / mm, and sufficient flexibility and strength to firmly bond devices to complex-shaped surfaces. The thickness of the thermal material was 82 μm, with a total number of layers of 5. Micro-holes were drilled in the front of the protective layer. In its original state, the thermal material is white.

[0200] The device was placed on a heating element at room temperature and heated to 50°C at a rate of 5°C / sec with a predetermined accuracy. After heating was stopped, the device was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent, revealing the underlying base color. The time required for the phase transition and change in transparency of the heat-sensitive material was 2 seconds. After cooling the device to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0201] 14. A suspension of yttrium caproate (100 g) with a phase transition temperature of 55°C, 100 g of methanol, and 100 g of a 3% solution of phenol-formaldehyde resin in methanol was prepared according to Example 2. This slurry was applied to OraJet 3106SG black-pigmented PVC film using a pressure of 1 mmHg and the method described in Example 4 to form an adhesive layer with fire resistance and electrical strength of at least 5 kV / mm, and sufficient flexibility and strength to securely bond devices to complex-shaped surfaces. The thickness of the thermal material was 310 μm, with a total number of layers of 15. Micro-holes were drilled between the protective layer and the substrate. In its original state, the thermal material was white.

[0202] The device was placed on a heating element at room temperature and heated to 55°C at a rate of 5°C / sec with a predetermined accuracy. After heating was stopped, the device was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and revealing the base color underneath. The time required for the phase transition and change in transparency of the heat-sensitive material was 1 second. After cooling the device to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0203] 15. A suspension of palmitic anhydride (100 g), 1-propanol (100 g), and a 1% solution of butyl methacrylate resin in 1-propanol (100 g) with a phase transition temperature of 60°C was prepared according to Example 2. This slurry was applied to a black pigmented 3981RA polyurethane film with an adhesive layer (thickness without adhesive: 0.2 mm) in the manner described in Example 5 using a pressure of 200 mmHg. The thickness of the thermal material was 428 μm, and the total number of layers was 20. Initially, the thermal material was white.

[0204] The device was placed on a heating element at room temperature and heated to 60°C at a rate of 5°C / sec with precise control. The heating was then stopped and the increase in transparency of the heat-sensitive material was visually confirmed to indicate operation. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and reveal the underlying base color. The time required for the phase transition and change in transparency of the heat-sensitive material was 2 seconds. After cooling the device to room temperature, it was visually noted that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0205] 16. A suspension was prepared of 100 g of eicosanoic acid (70°C), 100 g of isobutanol, and 100 g of a 10% solution of melamine-formaldehyde resin according to Example 2 in isobutanol. This slurry was applied to a 0.4 mm thick 3M:50 / RC20 / HD70WH yellow polyester film without an adhesive layer, according to the method described in Example 6, using a pressure of 1 mmHg after coating all layers and 200 mmHg before coating with a protective layer. Black paint was applied to the uncoated areas of the substrate before applying the slurry using a solvent dye. The thickness of the thermal material was 195 μm, and the total number of layers was 10. In its original state, the thermal material was white, completely covering the black paint applied to the base.

[0206] The device was placed on a heating element at room temperature, and the heating element was precisely controlled to heat up to 70°C at a rate of 5°C / sec. After this, heating was stopped and the device's operation was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and revealing the underlying base color. The time for the phase transition and change in transparency of the heat-sensitive material was 3 seconds. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0207] 17. A suspension of oleic acid amide (100 g) with a phase transition temperature of 75°C, ethylene glycol monomethyl ether (100 g), and a 15% solution of polyvinyl butyral in ethylene glycol monomethyl ether (100 g) was prepared according to Example 2. This slurry was applied to a 0.4 mm thick 3M:WHITEV TC black polyester film without an adhesive layer according to the method described in Example 7, with a pressure of 1 mmHg after each layer application, 30 mmHg after all layers were applied, and 200 mmHg before the protective layer coating. The thickness of the thermal material was 119 μm, and the total number of layers was 7. In its original state, the thermal material was white.

[0208] The device was placed on a heating element at room temperature and heated to 75°C at a rate of 5°C / sec with a predetermined accuracy. After heating was stopped, the device's operation was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and reveal the underlying base color. The time required for the phase transition and change in transparency of the heat-sensitive material was 3 seconds. After cooling the device to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0209] 18. A suspension of 1-docosanol (100 g) with a phase transition temperature of 70°C, 100 g of 1-butanol, and 100 g of a 25% solution of polybutyl methacrylate in 1-butanol was prepared according to Example 2. This slurry was applied to an adhesive-coated 3M:7874 E black pigmented polyester film, the thickness of which was 0.4 mm without the adhesive layer, according to the method described in Example 8. The thickness of the thermally sensitive material was 52 μm, and the total number of layers was 5. In its original state, the thermally sensitive material was white.

[0210] The device was placed on a heating element at room temperature and heated to 70°C at a rate of 5°C / sec with a predetermined accuracy. After heating was stopped, the device was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and revealing the base color underneath. The time required for the phase transition and change in transparency of the heat-sensitive material was 4 seconds. After cooling the device to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0211] 19. A suspension of dioctadecylamine (100 g) with a phase transition temperature of 70°C, 100 g of acetonitrile, and 100 g of a 30% solution of polybutyl acrylate in acetonitrile was prepared according to Example 2. This slurry was applied to a yellow ORALITE 5500 methyl methacrylate adhesive-layered film with an unadhered thickness of 0.4 mm according to the method described in Example 9, except that before applying the slurry, a black paint containing the threshold temperature value was applied to the uncoated areas of the substrate using a solvent dye. The thickness of the thermally sensitive material was 39 μm, and the total number of layers was 3. Initially, the thermally sensitive material was white.

[0212] The device was placed on a heating element at room temperature and heated to 70°C at a controlled rate of 5°C / sec. The device was then stopped and the increase in transparency of the thermal material was visually recorded to record its operation. Upon reaching the set temperature, an irreversible change occurred in the thermal material's microstructure, resulting in the material becoming transparent, revealing the color of the base material and the numerical value of the thermal material's microstructure. The time required for the thermal material's phase transition and change in transparency to occur was 4 seconds. After the device was cooled to room temperature, the device retained its appearance, and the transparency of the thermal material did not return to its original state.

[0213] 20. A suspension of solid organic material (100 g), acetic acid (100 g), and a 3% binder solution in acetic acid (100 g) according to Example 2 was prepared. The solid organic materials used were dioctylphosphinic acid with a phase transition temperature of 80°C, yttrium behenate with a phase transition temperature of 90°C, and lanthanum palmitate with a phase transition temperature of 100°C. The binders used were polyethylene, polyvinyl chloride, and polycarbonate. This slurry was applied to a yellow Optibelt elastomer film with an adhesive layer, as described in Example 10, to an unadhesive thickness of 0.4 mm. Prior to application of the slurry, the uncoated areas of the backing were painted black using a solvent dye. Each suspension of solid organic material in the liquid phase was applied to a separate area of ​​the substrate. The thicknesses of the thermally sensitive materials were 328, 406, and 394 μm, respectively, with 15 layers of each material. In their original state, the thermally sensitive materials were white in color. The device was placed on a heating element at room temperature and heated to 80°C at a controlled rate of 5°C / s with a predetermined accuracy. After heating, the heating was stopped and the corresponding zone of the device was visually observed to have become transparent, revealing the underlying base color. The first phase transition and transparency change occurred within 2 seconds. After the device was cooled to room temperature, it was visually recorded that the device maintained its appearance and the transparency of the thermal material did not return to its original state. The cycle of heating to 90°C and 100°C and then cooling to room temperature was repeated. After each cycle, the change in transparency of the corresponding zone of the thermal material was recorded. The second phase transition and transparency change occurred within 2 seconds, and the third within 1 second. After the device was finally cooled to room temperature, it was visually recorded that all areas containing the thermal material remained transparent.

[0214] 21. A suspension was prepared from 100 g of solid organic material, 100 g of 1,1,1,1-trifluoroethanol, and 100 g of a 3% binder solution in 1,1,1,1-trifluoroethanol according to Example 2. The solid organic materials used were lanthanum nonadecanoate (phase transition temperature 110°C), lanthanum caproate (phase transition temperature 120°C), zinc nonadecanoate (phase transition temperature 130°C), and zinc palmitate (phase transition temperature 140°C). Polyester, polymethacrylate, gelatin, and ethyl cellulose were used as binders. The suspension was applied to a 0.4 mm thick, adhesive-backed red Aurora self-adhesive fabric using the method described in Example 10. Prior to application of the suspension, black paint was applied to the uncovered areas of the backing using a solvent dye, and a numerical threshold temperature was applied to the front of the backing in the areas without the heat-sensitive material. Each suspension of solid organic material in a liquid phase was applied to a separate area of ​​the substrate. The thicknesses of the thermally sensitive materials were 53, 39, and 43 μm, respectively, with three layers of each material. In their original state, the thermally sensitive materials were white in color.

[0215] The device was placed on a heating element at room temperature and heated to 110°C at a controlled rate of 5°C / s with a predetermined accuracy. After heating, the heating was stopped and the corresponding zone of the device was visually observed to change in transparency. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the thermal material, causing it to become transparent, revealing its underlying base color. The first phase transition and transparency change occurred in 2 seconds. After cooling to room temperature, the device retained its appearance, and the transparency of the thermal material never returned to its original state. The cycle of heating to 120°C, 130°C, and 140°C and cooling to room temperature was repeated. After each cycle, the change in transparency of the corresponding zone of the thermal material was recorded. The second phase transition and transparency change occurred in 1 second, the third in 2 seconds, and the fourth in 1 second. After final cooling of the device to room temperature, it was visually noted that all areas with heat sensitive material remained clear.

[0216] 22. A suspension was prepared of 100 g of solid organic material, 100 g of 1,1,1,3,3,3,3-hexafluoroisopropanol, and 100 g of a 3% binder solution in 1,1,1,1,3,3,3-hexafluoroisopropanol according to Example 2. The solid organic materials used were n-docosylamine with a phase transition temperature of 65°C, tetracontane with a phase transition temperature of 80°C, and didecylphosphinic acid with a phase transition temperature of 90°C. The binders used were phenoxy resin, polyethersulfone, and polypropylene. This suspension was applied to a 0.4 mm thick red siliconized silica board without an adhesive layer, according to the method described in Example 7, using a pressure of 150 mmHg after each layer, 100 mmHg after all layers, and 450 mmHg before covering with a protective layer. Prior to slurry application, a black paint was applied to the uncovered areas of the substrate using a solvent dye, and a numerical threshold temperature was applied to the front surface of the substrate in areas without thermally sensitive material. Each suspension of solid organic material in a liquid phase was applied to a separate area of ​​the substrate. The thicknesses of the thermally sensitive materials were 387, 472, and 434 μm, respectively, with 15 layers of each material. In their original state, the thermally sensitive materials were white.

[0217] The device was placed on a heating element at room temperature and heated to 65°C at a controlled rate of 5°C / s with a predetermined accuracy, and the triggering of the corresponding zone of the device was recorded by visually noting the increase in transparency of the heat-sensitive material. The heating element was then immediately heated to a temperature of 80°C at a controlled rate of 5°C / s with a predetermined accuracy, and the actuation of another corresponding zone of the device was similarly recorded. The heating element was then immediately heated to a temperature of 90°C at a controlled rate of 5°C / s with a predetermined accuracy, and the actuation of a third corresponding zone of the device was recorded. After the device had cooled to room temperature, it was visually noted that all areas with heat-sensitive material remained transparent.

[0218] 23. A suspension of zinc caproate (100 g) with a phase transition temperature of 150°C and 100 g of dimethylformamide was prepared according to Example 1. This slurry was then applied to a 3 mm diameter black PVC tube having a fire resistance and electrical strength of at least 5 kV / mm, as well as flexibility and strength, using a pressure of 300 mmHg and the method described in Example 4. The thickness of the heat-sensitive material was 522 μm, and the total number of layers was 20. Initially, the heat-sensitive material was white.

[0219] The device was placed on a heating element at room temperature and heated to 150°C at a rate of 5°C / sec with a predetermined accuracy. After heating was stopped, the device's operation was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and revealing the base color underneath. The time required for the phase transition and change in transparency of the heat-sensitive material was 2 seconds. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0220] 24. A suspension of lithium stearate (100 g) with a phase transition temperature of 210°C and 100 g of a mixture of ethanol and water (50 / 50 vol.%) was prepared according to Example 1. This slurry was applied to a 1 mm thick white PVC cable clip with a diameter of 5 mm, fire resistance and electrical strength of at least 5 kV / mm, flexibility and strength, using a pressure of 650 mmHg as described in Example 5. Prior to applying the slurry, the uncoated parts of the backing were painted black using a solvent dye. The thickness of the thermal material was 84 μm, and the total number of layers was 5. Initially, the thermal material was white.

[0221] The device was placed on a heating element at room temperature and heated to 210°C at a rate of 5°C / sec with precise control. The heating was then stopped and the increase in transparency of the heat-sensitive material was visually confirmed to record the device's operation. Upon reaching the set temperature, an irreversible change occurred in the heat-sensitive material's microstructure, causing it to become transparent and revealing the underlying base color. The time required for the heat-sensitive material's phase transition and change in transparency to occur was 2 seconds. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the heat-sensitive material's transparency did not return to its original state.

[0222] 25. A suspension of stearic acid (100 g) with a phase transition temperature of 70°C, 100 g of butyl acetate, and 100 g of a 30% solution of polybutyl acrylate in butyl acetate was prepared according to Example 2. This slurry was applied to a 0.4 mm thick yellow ORALITE 5500 methyl methacrylate film without an adhesive layer by the method described in Example 6, using a pressure of 300 mmHg after application of the entire layer and 650 mmHg after application of the protective layer. Prior to application of the slurry, a black ink containing the threshold temperature value was applied to the uncovered areas of the substrate using a solvent dye. The thickness of the thermal material was 680 μm, and the total number of layers was 26. In its original state, the thermal material was white.

[0223] The device was placed on a heating element at room temperature and heated to 70°C at a controlled rate of 5°C / sec. The device was then stopped and the increase in transparency of the thermal material was visually recorded to record its operation. Upon reaching the set temperature, an irreversible change occurred in the thermal material's microstructure, resulting in the material becoming transparent, revealing the color of the base and the numerical value of the thermal material's microstructure. The time required for the thermal material's phase transition and change in transparency to occur was 3 seconds. After the device was cooled to room temperature, the device retained its appearance, and the transparency of the thermal material did not return to its original state.

[0224] 26. A suspension of 100 g of behenic acid (with a phase transition temperature of 80°C), 100 g of acetone, and 100 g of a 30% solution of polyvinylidene fluoride in acetone was prepared according to Example 2. This slurry was applied to a 0.4 mm thick ORALITE 5500 yellow-methyl methacrylate film without an adhesive layer according to the method described in Example 7, with a pressure of 300 mmHg after application of each layer, 200 mmHg after application of all layers, and 650 mmHg before coating with a protective layer. The uncoated areas of the substrate were coated with a black ink consisting of threshold temperature values ​​using a solvent dye before application of the slurry. The thickness of the thermal material was 282 μm, and the total number of layers was 10. Initially, the thermal material was white.

[0225] The device was placed on a heating element at room temperature and heated to 80°C at a controlled rate of 5°C / sec. The device was then stopped and the increase in transparency of the thermal material was visually recorded to record its operation. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the thermal material, resulting in the material becoming transparent, revealing the color of the base material and the numerical value of the thermal material's microstructure. The time required for the phase transition and change in transparency to occur was 2 seconds. After the device was cooled to room temperature, the device retained its appearance, and visual observation confirmed that the transparency of the thermal material did not return to its original state.

[0226] 27. A suspension of erucamide (100 g) with a phase transition temperature of 75°C and hexane (100 g) was prepared according to Example 1. This slurry was applied to a yellow ORALITE 5500 methyl methacrylate adhesive-layered film with an unadhered thickness of 0.4 mm using a pressure of 150 mmHg according to the method described in Example 4, with a black ink containing the threshold temperature value applied to the uncovered areas of the substrate using a solvent dye prior to application of the slurry. The thickness of the thermally sensitive material was 429 μm, and the total number of layers was 17. In its original state, the thermally sensitive material was white.

[0227] The device was placed on a heating element at room temperature and heated to 75°C at a controlled rate of 5°C / sec. The device was then stopped and the increase in transparency of the thermal material was visually recorded to record its operation. Upon reaching the set temperature, an irreversible change occurred in the thermal material's microstructure, resulting in the material becoming transparent, revealing the color of the base material and the numerical value of the thermal material's microstructure. The time required for the thermal material's phase transition and change in transparency to occur was 4 seconds. After the device was cooled to room temperature, the device retained its appearance, and the transparency of the thermal material did not return to its original state.

[0228] 28. A suspension of stearic acid alcohol (100 g) and heptane (100 g) with a phase transition temperature of 60°C was prepared according to Example 1. This slurry was applied to a yellow ORALITE 5500 methyl methacrylate film having an unattached adhesive layer of 0.4 mm thickness using a pressure of 300 mmHg as described in Example 3. Prior to applying the slurry, a black ink containing the threshold temperature value was applied to the uncovered areas of the substrate using a solvent dye. The thickness of the thermally sensitive material was 61 μm, and the total number of layers was 4. In its original state, the thermally sensitive material was white.

[0229] The device was placed on a heating element at room temperature and heated to 60°C at a controlled rate of 5°C / sec. The heating was then stopped and the increase in transparency of the heat-sensitive material was visually recorded to record the device's operation. Upon reaching the set temperature, an irreversible change occurred in the heat-sensitive material's microstructure, causing it to become transparent, revealing the underlying base color and the numerical values ​​of the heat-sensitive material's microstructure. The time required for the heat-sensitive material's phase transition and change in transparency to occur was 4 seconds. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the heat-sensitive material's transparency did not return to its original state.

[0230] 29. A suspension of cetyl alcohol (100 g) with a phase transition temperature of 50°C, 100 g of toluene, and 100 g of a 30% solution of nitrocellulose in toluene was prepared according to Example 2. This slurry was applied to a yellow ORALITE 5500 methyl methacrylate adhesive-layered film with an undeposited thickness of 0.4 mm using a pressure of 450 mmHg as described in Example 5. Prior to applying the slurry, a black ink containing the threshold temperature value was applied to the uncovered areas of the substrate using a solvent dye. The thickness of the thermally sensitive material was 92 μm, and the total number of layers was 8. In its original state, the thermally sensitive material was white.

[0231] The device was placed on a heating element at room temperature and heated to 50°C at a rate of 5°C / sec with a predetermined accuracy. The heating was then stopped and the increase in transparency of the thermal material was visually recorded to record the device's operation. Upon reaching the set temperature, an irreversible change occurred in the thermal material's microstructure, resulting in the material becoming transparent, revealing the color of the base and the numerical value of the thermal material's microstructure. The time required for the thermal material's phase transition and change in transparency to occur was 1 second. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the thermal material's transparency did not return to its original state.

[0232] 30. A suspension was prepared of dispersed polyethylene (100 g) with a phase transition temperature of 110°C, 100 g of o-xylene, and 100 g of a 30% solution of polycaprolactone in o-xylene according to Example 2. This slurry was applied to a yellow ORALITE 5500 methyl methacrylate adhesive-layered film with an undeposited thickness of 0.4 mm using the method described in Example 3 at a pressure of 150 mmHg. Prior to applying the slurry, a black ink containing the threshold temperature value was applied to the uncovered areas of the substrate using a solvent dye. The thickness of the thermally sensitive material was 252 μm, and the total number of layers was 13. In its original state, the thermally sensitive material was white.

[0233] The device was placed on a heating element at room temperature and heated to 110°C at a rate of 5°C / sec with a predetermined accuracy. The heating was then stopped and the increase in transparency of the thermal material was visually recorded to record the device's operation. Upon reaching the set temperature, an irreversible change occurred in the thermal material's microstructure, resulting in the material becoming transparent, revealing the color of the base and the numerical value of the thermal material's microstructure. The time required for the thermal material's phase transition and change in transparency to occur was 2 seconds. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the transparency of the thermal material did not return to its original state.

[0234] 31. A suspension of 100 g of dotriacontan-1-ol (100 g) with a phase transition temperature of 90°C and 100 g of a mixture of ethanol and water (50 / 50 vol.%) was prepared according to Example 1. This slurry was applied to OraJet 3951 yellow-pigmented PVC film with an uncoated adhesive layer having a thickness of 0.3 mm, as described in Example 6, using a pressure of 150 mmHg after coating all layers and 450 mmHg before coating with a protective layer. Prior to applying the slurry, a black ink containing the threshold temperature value was applied to the uncoated areas of the backing using a solvent dye. The thickness of the thermal material was 452 μm, and the total number of layers was 18. In its original state, the thermal material was white.

[0235] The device was placed on a heating element at room temperature and heated to 90°C at a controlled rate of 5°C / sec. The heating was then stopped and the device's operation was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and revealing the base color underneath. The time required for the phase transition and change in transparency of the heat-sensitive material was 2 seconds. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0236] 32. A suspension was prepared of solid organic material (100 g), 100 g of isopropanol, and 100 g of a 3% binder solution in isopropanol according to Example 2. The solid organic materials used were tridecane anhydride with a phase transition temperature of 50°C, docosane nitrile with a phase transition temperature of 55°C, and palmitic acid with a phase transition temperature of 60°C. The binders used were polyethylene, polyvinyl chloride, and polycarbonate. This slurry was applied to a yellow Optibelt elastomer film with an adhesive layer, as described in Example 10, to an unadhesive thickness of 0.4 mm. Prior to application of the slurry, the uncoated areas of the backing were painted black using a solvent dye. Each suspension of solid organic material in the liquid phase was applied to a separate area of ​​the substrate. The thicknesses of the thermally sensitive materials were 328, 406, and 394 μm, respectively, with 15 layers of each material. In their original state, the thermally sensitive materials were white. The device was placed on a heating element at room temperature and heated to 50°C at a controlled rate of 5°C / s with a predetermined accuracy. After heating, the heating was stopped and the corresponding zone of the device was visually observed to have become transparent, recording the triggering of the corresponding zone. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the thermal material, resulting in the thermal material becoming transparent and revealing its underlying base color. The time for the first thermal material to undergo the phase transition and transparency change was 1 second. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the thermal material's transparency never returned to its original state. The cycle of heating to 55°C and 60°C and then cooling to room temperature was repeated. After each cycle, the change in transparency of the corresponding zone of the thermal material was recorded. The time for the second thermal material to undergo the phase transition and transparency change was 3 seconds, and that for the third thermal material was 1 second. After the device was finally cooled to room temperature, it was visually recorded that all areas containing the thermal material remained transparent.

[0237] 33. Exposing the device to temperatures close to the threshold temperature for extended periods. The device according to Example 22 was placed on a heating element at room temperature and then heated in a controlled manner to 140°C at a rate of 5°C / sec and held at this temperature for 10 hours. Heating was then stopped and it was noted that the original appearance of the device was maintained. The device was then cooled to room temperature, with no change in the transparency of the heat-sensitive material, and the device's appearance remained unchanged.

[0238] The device was then heated to 150°C at a rate of 5°C / sec with a predetermined accuracy, and the device's operation was recorded by visually observing the increase in transparency of the heat-sensitive material. Upon reaching the set temperature, an irreversible change occurred in the microstructure of the heat-sensitive material, causing it to become transparent and reveal the underlying base color. After the device was cooled to room temperature, it was visually recorded that the device retained its appearance and the transparency of the heat-sensitive material did not return to its original state.

[0239] Furthermore, the trigger device was placed in a refrigerator set at -20°C and kept at this temperature for 10 hours, and the retention of transparency of the heat-sensitive material was recorded after this time and after the device's temperature was returned to room temperature. Thus, it was found that the device maintains its initial state at a temperature close to the threshold temperature before activation, and after activation, it does not return to its initial state even when left at a lower temperature for a long period of time.

Claims

1. 1. A device for visually detecting a temperature above at least one threshold, the device having a layered structure comprising: A substrate that is partially opaque to visible light and has a numerical marking on its surface indicating at least one threshold temperature; at least one heat-sensitive material that is opaque to at least a portion of visible light, applied to individual portions of the substrate, the microstructure of which includes particles of solid organic matter and voids filled with a gas phase; a transparent protective layer that partially or completely covers the front of the device; Here, the device is fabricated to have the ability to irreversibly change its appearance upon reaching at least one threshold temperature indicated therein by destruction of the microstructure of the corresponding heat-sensitive material with fusion of particles of solid organic matter, reduction in the proportion of voids, and increase in transparency with appearance of a base color.

2. 2. The device of claim 1, wherein the pressure of the gas phase within the gap of the heat-sensitive material is lower than atmospheric pressure.

3. 2. The device according to claim 1, characterized in that a gap is formed between the transparent protective layer and the base, or micro-holes are formed in the protective layer, allowing gas contained in the cavities to escape from the device after exceeding a registered temperature.

4. 2. The device of claim 1, wherein in the microstructure of the at least one heat-sensitive material in its initial state, the particles of the solid organic substance are preferentially oriented parallel to the surface planes of the substrate and the protective coating.

5. 10. The device of claim 1, wherein the void fraction of at least one heat-sensitive material is reduced by at least a factor of two after heating above a respective temperature threshold.

6. The device of claim 1, wherein the solid organic substance of the temperature-sensitive material is selected from the group consisting of: fatty aliphatic acids containing at least 13 carbon atoms; salts of fatty aliphatic acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing at least 16 carbon atoms; amides of fatty aliphatic acids containing at least 3 carbon atoms; anhydrides of fatty aliphatic acids containing at least 22 carbon atoms; fatty aliphatic alcohols containing at least 16 carbon atoms; fatty aliphatic amines containing at least 17 carbon atoms; nitriles of fatty aliphatic acids containing at least 20 carbon atoms, or mixtures thereof.

7. 2. The device according to claim 1, characterized in that the solid organic substance of the heat-sensitive material is selected from the group consisting of palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearic alcohol, cetyl alcohol, dispersed polyethylene, saturated fatty carboxylates of rare earth metals, in particular lanthanum, yttrium, ytterbium, scandium.

8. 10. The device of claim 1, wherein the at least one heat-sensitive material microstructure further comprises a polymer binder transparent to at least a portion of visible light in an amount of 1-30 wt %.

9. The device according to claim 1 is made in the form of a sticker comprising an insulating layer, an adhesive layer, an elastic base made of a halogen-containing polymer, having a thickness of less than 1 mm and a dielectric strength of at least 5 kV / mm, which is opaque to at least a portion of visible light, and at least one heat-sensitive material having a thickness of 800 microns or less, applied to a separate portion of the base, the heat-sensitive material being configured to have the potential to irreversibly change its transparency when a corresponding threshold value is reached.

10. 10. The device according to claim 1, which differs in that its surface is made in the form of an elastic hollow tube intended to be attached to a wire, which serves as a base that is opaque to at least part of visible light, made of a halogen-containing polymer, has a thickness of less than 1 mm and a dielectric strength of more than 5 kV / mm, and has at least one heat-sensitive material applied to some parts of its front surface with a thickness of less than 800 microns, which heat-sensitive material is made to have the potential to be irreversibly changed on the surface of the device.

11. 10. The device of claim 1, comprising a longitudinal section and made in the shape of a tube intended for attachment to an electrical wire, the surface of which has a thickness of less than 1 mm and is made of a halogen-containing polymer having a dielectric strength of at least 5 kV / mm, and which serves as a base that is opaque to at least a portion of visible light, and in which some portions of the front surface are coated with at least one heat-sensitive material having a thickness not exceeding 800 microns, the heat-sensitive material being made to have the potential for being non-transparent to at least a portion of visible light.

12. 12. The device according to any one of claims 9 to 11, wherein the base is reflective or luminescent.

13. 12. Apparatus according to any one of claims 9 to 11, characterized in that the surface area of ​​the substrate coated with the at least one heat-sensitive material is at least 100 mm2.

14. 2. A device according to claim 1, characterized in that it has the possibility of registering controlled point heating of the surface by changing the transparency of only those areas of the heat-sensitive material which have been heated above a threshold temperature.

15. 10. A method for manufacturing a device for visually detecting temperatures exceeding at least one threshold as claimed in claim 1, comprising the steps of: applying to separate areas of the opaque base one or more layers of at least one suspension of particles of a solid organic substance in a liquid phase, the boiling point of which is less than 180°C and the solubility of the particles of the solid organic substance in the liquid phase does not exceed 10 g / kg; removing the liquid phase from the applied layer of the suspension of particles of solid organic material in the liquid phase to form a heat-sensitive material that is opaque to at least a portion of visible light, the microstructure of which includes particles of solid organic material and voids filled with a gas phase; Coating the front surface of the workpiece with a transparent protective layer; wherein at least one of the above steps is carried out at subatmospheric pressure.

16. 16. The method of claim 15, wherein the backbone comprises a halogen-containing polymer.

17. 16. The method of claim 15, wherein the solid organic substance of the heat-sensitive material(s) is selected from the group consisting of: fatty aliphatic acids containing at least 13 carbon atoms; salts of fatty aliphatic acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing at least 16 carbon atoms; amides of fatty aliphatic acids containing at least 3 carbon atoms; anhydrides of fatty aliphatic acids containing at least 22 carbon atoms; fatty aliphatic alcohols containing at least 16 carbon atoms; fatty aliphatic amines containing at least 17 carbon atoms; nitriles of fatty aliphatic acids containing at least 20 carbon atoms or mixtures thereof.

18. 10. A method for manufacturing a device for visually registering temperatures exceeding at least one threshold value according to claim 1, comprising carrying out at least three cycles, each cycle comprising applying a layer of at least one suspension of particles of solid organic material in a liquid phase to a separate area of ​​an opaque base and removing the liquid phase from the applied layer, and further comprising covering the front surface of the workpiece with a transparent protective layer, wherein the boiling point of the liquid phase is less than 180°C; wherein the suspension of particles of solid organic matter in a liquid phase is applied by a method selected from the group of screen printing, flexographic printing, pad printing, silk screen printing to obtain a microstructure of at least one heat-sensitive material, in which the particles of the solid organic matter are oriented predominantly parallel to the plane of the surface of the substrate.

19. 19. The method of claim 18, wherein the backbone comprises a halogen-containing polymer.

20. 19. The method of claim 18, wherein the solid organic substance of the heat-sensitive material(s) is selected from the group consisting of: fatty aliphatic acids containing at least 13 carbon atoms; salts of fatty aliphatic acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing at least 16 carbon atoms; amides of fatty aliphatic acids containing at least 3 carbon atoms; anhydrides of fatty aliphatic acids containing at least 22 carbon atoms; fatty aliphatic alcohols containing at least 16 carbon atoms; fatty aliphatic amines containing at least 17 carbon atoms; nitriles of fatty aliphatic acids containing at least 20 carbon atoms, or mixtures thereof.

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