Device for visually recording overhigh temperature and method for manufacturing the

Abstract

The present invention relates to a device for visually recording the fact that the temperature exceeds at least one threshold, the principle of operation of which consists in changing the microstructure of a heat-sensitive material at a specified threshold temperature value while accompanying an irreversible visual effect, as well as a variant of the method for manufacturing the device. A device for visually recording a temperature rise exceeding at least one threshold, having a layered structure, comprising:-a substrate opaque to at least partially visible light, engraved on its front surface with an inscription indicative of at least one numerical threshold temperature value; -at least one heat-sensitive material opaque to at least partially visible light applied to each portion of the substrate, the microstructure of which comprises particles of a solid organic substance and voids filled with the gas phase; and a transparent protective layer partially or fully covering the front surface of the device. Wherein the device is designed with the ability to irreversibly change its appearance as a result of a disruption of the microstructure of the corresponding heat-sensitive material when at least one threshold temperature indicated thereon is reached, while accompanying fusion of the particles of the solid organic matter, a reduction in the void ratio and an increase in the transparency and the development of the substrate color. A variant of a method for manufacturing a device for visually recording a temperature rise exceeding at least one threshold is also disclosed. The set of inventions improves the reliability and accuracy of the visual recording of the fact that the temperature exceeds at least one threshold value, it is impossible to restore the heat-sensitive material to its original state, and improves the response speed of the heat-sensitive material, including under conditions of short-term peak load or emergency mode of operation of the controlled device element, the reliability and accuracy of the visual recording of the fact that the temperature exceeds at least one threshold value. And the operation safety of the controlled equipment and the recording equipment during the whole service life is improved.

Description

Technical Field

[0001] The inventive group relates to a device for visually recording temperatures exceeding at least one threshold value, the operating principle of which includes changing the microstructure of a thermosensitive material at a specified threshold temperature value, accompanied by an irreversible visual effect, and variants of a method for manufacturing such a device. Background Art

[0002] An increase in temperature is one of the primary and most common signs of defects in various devices, such as an increase in transient contact resistance in the power industry, a malfunction of bearings in machinery, an inter-turn short circuit in the windings of an electric motor, and a malfunction of a charger or battery in household appliances. Timely detection of such overheating helps to eliminate faults at an early stage and prevent equipment failures, emergencies, and related fires or outages. Technical and regulatory documents specify the maximum allowable temperature, and heating above this temperature should be regarded as a defect that requires immediate cessation of operation 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.).

[0003] To identify defects associated with exceeding the maximum allowable temperature, various diagnostic methods can be used. The most widely used method of thermal diagnostics is thermographic control. However, thermographic diagnostics has a fundamental limitation in that it can only display a thermal image during the inspection. Since equipment heating is directly related to its load in most cases, the most useful and reliable diagnostics are those carried out at peak load (nominal or starting current, maximum speed, etc.). According to the guidelines for conducting thermographic diagnostics, it is recommended to create special loading modes for equipment, institutions, and units. In addition, due to design features or safety requirements, most modern equipment does not allow inspection under load. Therefore, the rate of defect detection using a thermal imager is low.

[0004] To achieve automatic continuous temperature control, electronic devices such as thermoelectric converters (thermocouples), pyrometers, and other sensors with special recording devices, or various overheat indicators are used. A special feature of electronic sensors is that they only measure the temperature at the contact point between the sensor and the device. This does not allow the detection of local defects occurring in separate parts of a large surface, such as inter-turn short circuits in a transformer or partial discharges occurring in a cable sheath or cable joint. In this case, a small part of the outer insulation layer of the cable (with an area of a few square millimeters) is heated. For example, when a thermocouple is fixed only a few centimeters away from the defect or placed inside the cable, it is impossible to see this heating. In addition, electronic sensors are complex in design, require a power source, and do not allow the measurement of the temperature of moving parts or circuit sections under high voltage.

[0005] Other methods of continuous overheat control include chemical or mechanical temperature indicators, which can be divided into two types: reversible (changing appearance only when heated and returning to the original state when cooled) and irreversible (changing appearance after exceeding the set temperature and maintaining the appearance after cooling). An example of a reversible device is the invention described in document US7600912B2 (publication date March 20, 2007), which is a single-layer or double-layer sticker whose thermosensitive element contains a colorless dye and a developer in an adhesive. When a certain temperature is reached, the adhesive melts, and the developer reacts with the dye, coloring the label. After the temperature drops, the dye crystallizes and the color returns. Document RU2561737C1 (publication date September 12, 2014) describes an inorganic reversible temperature indicator based on chromium(III) complexes. The proposed thermochromic material can reversibly change color when heated above 120°C. The feature of such inventions is the need to visually record heating when the temperature exceeds the limit, and the inability to detect defects outside the peak load, which is why these devices have not been widely popularized.

[0006] Different from reversible indicators, irreversible indicators can not only detect but also record the fact that the threshold temperature has been exceeded. In addition, different from thermal imagers or reversible indicators, the inspection of such stickers can be carried out without creating a maximum load mode, and even on the equipment being repaired.

[0007] Irreversible heating indicators can be classified according to their working principles. Known indicators are based on mechanical damage of thermosensitive elements, chemical reactions of composition components, or phase changes of thermosensitive components.

[0008] An example of a temperature indicator based on mechanical destruction is described in the document [US6176197B1, publication date November 2, 1998]. According to this document, the temperature indicator is a closed, hollow, transparent, slender tube with two components of different colors, separated from each other by a polymer partition with a melting point close to the melting point of the components. When the set threshold temperature is reached, the partition is destroyed, the components melt and mix, resulting in a change in the color of the contents of the tube. The features of this invention include the inability to monitor overheating of the entire surface and a low response speed, because to complete the color change, not only is it necessary to completely melt the indicator composition and the polymer film separating them, but also time is required to mix the resulting liquid phase, which can be difficult due to the insufficiently fast diffusion process near the melting point. In addition, the design features of the said invention do not allow the creation of a flexible device that closely adheres to the entire controlled surface.

[0009] The patent [EP2288879B1, publication date June 4, 2008] describes a chemical reaction for etching a metal substrate with an activator when a certain temperature is reached. The color of this indicator changes from silver-white or mirror-like to colorless and can be used to monitor the temperature of food and medical products as well as electrical equipment. The metal layer and the activator layer can be applied to a film made in the form of a sticker, thus ensuring the flexibility of the product and its ability to adhere to various surfaces. Another example of a temperature indicator based on chemical interaction is the invention described in the source [US6957623B2, publication date March 9, 2004]. In this case, the temperature-sensitive material contains a mixture of water, latex, and active microorganisms that form ice and is transparent until the threshold temperature is reached. When heated to a certain temperature, the latex and the active microorganisms that form ice interact to form an opaque substance. Among commercially available indicators whose operating principle is based on a chemical reaction process, the Retomark model indicator provided by the limited liability company "Innovative Company "YALOS"" (https: / / www.yalosindicator.com / product / termoindikatory-kontrol-temperatury) can be selected.

[0010] The proposed irreversible temperature indicator, whose operating principle is based on a chemical reaction, is characterized by low accuracy because, according to the Arrhenius equation, the progress of a chemical reaction depends not only on temperature but also on time. Therefore, prolonged exposure of the composition to a temperature slightly below the threshold can also cause the product to be triggered. At the same time, the above standard stipulates a specific temperature threshold with an interval of no more than 5 °C, which makes the said invention not suitable for defect detection. Another characteristic of such devices is that the response time has a significant dependence on temperature: when heated to the threshold for a short time, the chemical reaction may not be completed, the color of the indicator does not change or is insufficient for detection. In addition, due to the reversibility of the color change reaction, the appearance of some products will return to its original state after prolonged exposure to low temperatures.

[0011] The most accurate temperature indicators are those based on phase transitions (i.e., the melting of a thermosensitive component). Since, unlike chemical reactions, the phase transition temperature does not depend on the exposure time, such indicators have the highest accuracy and are able to maintain their original appearance indefinitely at a temperature slightly below the threshold.

[0012] An irreversible indicator based on the principle of phase change of a thermosensitive component can be made in the form of a sticker or a coating. The use of temperature-indicating paints and varnishes, whose operating principle is based on the melting of pigments, has been described in many documents, such as including CN112322134A (publication date September 23, 2020), CN1 11849346A (publication date July 11, 2020), CN108610694A (publication date December 9, 2016), SU1 765145A1 (receipt date October 30, 1989), SU576334A1 (publication date May 25, 1976). Usually, such a coating consists of a synthetic resin, a filler, and a fusible component dispersed in water or a solvent. When heated above the set temperature, the thermosensitive component melts, causing the color of the composition to change due to the change in refractive index. Usually, after cooling, the color of such a composition does not change or only changes slightly, which makes it easy to record the fact of overheating during visual inspection. The exact location of the temperature increase can be determined by covering a large area with a thermosensitive coating. Another advantage of such an indicator is the ability to apply it to surfaces of any shape and size.

[0013] However, indicator paints have many characteristics, including:

[0014] - The temperature cannot be marked on the paint. During visual inspection of the device, the operator can only see the fact that the temperature has been exceeded, but cannot determine the value above the threshold. For this purpose, special instructions are required. Without such a record, it may lead to errors.

[0015] - Indicate the flow of the paint when the threshold temperature is exceeded. After the thermal element melts, under the influence of temperature, the viscosity of the paint decreases and it will flow from the surface onto the open conductive elements of the electrical equipment or the moving elements of the mechanism, resulting in accidents such as short circuits, loss of electrical strength, heating, blockage, and fire.

[0016] - Since the paint is unevenly applied on the surface, the temperature cannot be measured with high precision. This is especially true for elements with complex surface geometries. Therefore, areas with a thicker paint layer require more time to heat up, and the difference between the surface temperature and the phase change (operating) temperature will be greater than that of areas with a thinner paint layer.

[0017] - Wires made of non-sticky materials (silicone, polyethylene, fluoroplastics) have low adhesion and are difficult to paint. To clearly show overheating, a large amount of heat-melting pigment is required, which usually leads to a decrease in the proportion of polymer binder in the composition and a reduction in the adhesion of the paint. This causes the composition to easily peel off due to mechanical shock.

[0018] - The dependence of the paint response temperature on the surface chemical coating. Since the paint is in direct contact with the applied materials (such as the paint on the cable insulation or the engine housing), various substances (mainly flame retardants and plasticizers) will be extracted into the paint. These substances may cause the formation of eutectic mixtures with the heat-melting components or otherwise affect the phase change temperature.

[0019] Another feature of the above inventions is that due to the sublimation of the main substances, their operating ability under low pressure or vacuum conditions is limited. The literature SU867919A1 (publication date September 30, 1981), SU401214A1 (publication date May 8, 1976) describes thermosensitive compounds for visually and photographically measuring the surface temperature of an object under atmospheric pressure and vacuum conditions up to 10-4 mm Hg. They contain a mixture of thermosensitive components, including salts or esters of higher carboxylic acids, binders, and ethanol. An alcohol solution of BF-2 or BF-4 binder is used as the binder. However, they are only provided in the form of thermal coatings, and their general disadvantages have been listed above.

[0020] Special indicating devices (such as stickers, fine linen, clips, etc.) do not have the above problems because the heat-melting composition is evenly and thinly applied on the substrate under factory conditions to ensure good adhesion to the required surface. In addition, it is covered with a polymer film to protect the heat-melting composition from mechanical or chemical shock and will not flow out when it melts during operation.

[0021] Irreversible temperature-sensitive devices can be made in single-temperature and multi-temperature versions. The advantage of irreversible multi-temperature indicators is that they can not only determine the fact of exceeding a given temperature, but also determine the value of the maximum surface temperature to which the controlled element is heated during operation, track the dynamics of defect development, and provide the ability to compare the overheating temperatures of the same elements (equipment units). Single-temperature indicators can clearly record the exceeding of the maximum temperature allowed for controlled electrical equipment and electrical device units, thus ensuring timely notification to the inspector of the occurrence of an emergency or pre-emergency situation and enabling prompt action to eliminate possible consequences.

[0022] Compounds such as higher carboxylic acids and their salts, paraffins, waxes, esters of polyhydric alcohols, complexes of transition metals, metal alloys, etc. are usually used as substances of the thermosensitive component in such indicators.

[0023] It is known from the prior art that thermosensitive devices based on the phase change of a hot-melt component can be classified according to the working principle that ensures a color change of the device: the transparency of the hot-melt component changes during melting or a dye dissolves in the melt. In the inventions containing dyes, a thermosensitive material is known in which the dye is uniformly distributed in a solid polymer binder (WO2018176266A1, publication date October 4, 2018). When the material is heated to the melting point of the binder, the dye dissolves in it, thus changing its color. Wax, low-melting polymers, non-polymeric organic substances (vanillin or triphenylphosphine) or mixtures thereof can be used as the polymer binder. The material according to invention US6602594B2 (publication date August 5, 2003) is constructed in a similar way, where the initial state of particulate or powdered dye is mixed with the hot-melt substance and is able to diffuse into it by dispersion or dissolution when a given temperature is reached. Derivatives of fatty acids, alcohols, ethers, aldehydes, ketones, amines, amides, nitriles, hydrocarbons, thiols and sulfides can be used as the hot-melt component. The characteristics of the proposed methods include insufficient color transition contrast, since the dye in the solid binder also imparts its corresponding color, and the fact that the dye particles coagulate during the cooling process in some products, resulting in the original color being restored after cooling.

[0024] Many inventions are based on the penetration of a heat-meltable component into a substrate, resulting in a color change in the device. Wax coated on a colored paper backing becomes transparent and penetrates into the paper substrate when it reaches its melting temperature, thus revealing its color (US20060011124A1, publication date July 15, 2004). Another example is a device consisting of an opaque porous membrane and an amorphous polymer or a colored composite layer applied to the bottom layer of the membrane, which includes a polymer binder, a crystalline material, and a dye (US4428321A, publication date November 16, 1981; WO2019090472A1, publication date November 7, 2017). As the temperature rises, the thermosensitive material melts and penetrates into the porous membrane. Since the refractive index of this material is the same as that of the membrane, the membrane becomes transparent. A notable feature of this type of device is that the material in the pores of the membrane or substrate crystallizes, so it loses transparency and the color indication will be destroyed.

[0025] The prior art includes the invention described in source WO2018176266A1 (publication date October 14, 2018), which represents a thermal indicator composition containing an organic solid material with a melting point higher than the ambient temperature, and a dye that is in contact with the organic solid material and can dissolve in the organic solid material when heated to the melting point of the organic solid material. In this case, the organic solid material is presented in the form of a continuous phase, in which the dye particles are distributed in clusters or crystals. When the device reaches the melting temperature of the organic solid material, the material melts, causing the dye particles to dissolve in the molten material, thus coloring the entire material volume with the color corresponding to the dye. In some embodiments of the present invention, the indicator composition is applied to a substrate containing grooves and depressions. When the organic solid material melts and the dye dissolves in it, not only does the color of the indicator layer change, but the material also penetrates into the grooves and depressions of the substrate, and corresponding patterns appear. In another embodiment of the present invention, the device is manufactured by applying layer by layer an organic solid material with a thickness of 1 - 25 microns, a dye with a thickness of 0.1 - 0.5 microns, and additional layers providing the necessary operating characteristics: adhering the device to a surface and protecting the device from external influences, including ultraviolet radiation. However, the said invention has many characteristics, such as a low contrast in color transition when reaching the melting temperature, a low accuracy of the indicator composition if the temperature of the device does not exceed the melting temperature of the organic material, and the need to select a combination of dye and solid organic material to ensure maximum solubility and the formation of a colored solution. In addition, this document does not show the degree of irreversibility of the color change when the device is cooled to a temperature below the melting point of the organic material.

[0026] Some commercial devices are based on the principle of changing the color of the hot-melt component itself without using additional dyes. These devices are stickers coated with a thermosensitive substance that melts and changes transparency when a given temperature is reached, and the melted substance does not penetrate into the pores of the substrate. The closest analogues to the proposed group of inventions are temperature indicator elements produced and / or supplied by companies such as LLC "Innovative Company "YALOS" and Closed Joint-Stock Company Non-State Pension Fund "Luminofor".

[0027] The prototype of the declared device is a temperature-indicating sticker produced by the Japanese company NiGK Co., Ltd. (https: / / contents.bownow.jp / files / index / sid_9c257787049ca562bbda?client_id=d867dc3c-ab2f-4a08-ba5a-32d9c6b2c5a1&access_token=&referer=https%3A%2F%2Fwww.nichigi.co.jp%2Fen%2Fen_downloadform%2Fen_data.html, which is a catalog dedicated to temperature-indicating materials). It discloses a series of irreversible indicating stickers (such as LE, 3E, 4E, 5E, 8E, F, 1K, 3K, 3R, 5S, Mini series) coated with a thermosensitive material on a painted substrate. High-precision temperature measurement is achieved by utilizing the effect of the change in transparency when the purified stable pigment reaches the melting point, and visibility is achieved by revealing the color of the substrate. At the same time, as described in the catalog, the indicator is irreversible and does not return to its original color once triggered. The LE, 3E, 4E, 5E, 8E, F series stickers have a service life of 5 years indoors and 3 years outdoors, and the 1K, 3K, 3R, 5S, Mini series stickers have a service life of 3 years indoors and are not applicable outdoors.

[0028] These indicating stickers have some characteristics that significantly limit their large-scale use:

[0029] - The service life of the labels is insufficient because it is very important for the service life of the device used to record the fact of overheating to be equal to or greater than the service life of the equipment on which they are installed, since during operation it may not be possible to access certain units of electrical devices, and temperature-sensitive elements must be connected to these units at the stage of assembly or repair work;

[0030] - Just paste the sticker on a flat surface, because pasting it on a curved surface or a corner may cause inaccurate device operation. The manufacturer warns about this on page 2 of the given catalog. This indicates that the sticker substrate and the thermosensitive material layer are not flexible enough. Pasting them on a surface with a complex shape will cause cracks to appear and the thermosensitive material layer to peel off from the substrate, as well as uneven heating of the thermosensitive material, which will also reduce the accuracy of overheat registration;

[0031] - The device has low operating reliability because the opacity of the composition may be lost during use, especially when the sticker with a threshold temperature exceeding 130 °C is kept at a high temperature. The manufacturer warns about this on page 2 of the given catalog, and the opacity partially recovers after the device operates.

[0032] The above characteristics are attributed to the following points.

[0033] To ensure that the thermosensitive layer has the maximum opacity and keep the color of the coating substrate in its original invisible state, it is required that the thermosensitive material has a high light absorption coefficient and scattering coefficient. These characteristics are possessed by materials containing multiple phase boundaries, and light scatters in different directions at these phase boundaries. In the devices known in the prior art, a large-area phase boundary is created by distributing the crystals of the hot-melt component in the adhesive, that is, the "solid-in-solid" system. The light incident on the material of this structure will be reflected and scattered from the numerous surfaces of the crystals and cannot reach the colored substrate, so it cannot be seen and the material is opaque. When melted, the phase state of the solid crystals changes to a liquid state, thus obtaining the shape of spherical droplets, which reduces the total area of the phase boundaries and makes the material transparent. Further cooling solidifies the hot-melt component into spheres while maintaining the transparency of the material.

[0034] However, over time, some changes may occur in these materials, significantly reducing their performance characteristics:

[0035] - Since the adhesive molecules penetrate into the lattice of the thermosensitive component, a solid solution with a polymer adhesive can be formed on the crystal surface. This will cause the crystal boundaries to become smooth and the phase boundary area to decrease, thereby increasing the transparency of the material and the risk of overheat error detection;

[0036] - Recrystallization may occur due to partial dissolution of the crystals in the adhesive, which will cause the crystals to become larger, and this will also lead to a reduction in the number of phase boundaries and a decrease in opacity;

[0037] - When a solid eutectic mixture with a melting point lower than that of the individual components appears at the phase boundary, the response temperature of the device will be changed and the accuracy of recording the fact of over-temperature will be reduced.

[0038] When the device operates at a temperature slightly below the threshold, the above process will be significantly accelerated, especially for stickers with a relatively high threshold temperature. Therefore, the service life of such devices will even be significantly shortened compared to the values declared by the manufacturer in the prototypes.

[0039] The need to use a relatively large layer of thermosensitive components will also result in:

[0040] - Insufficient flexibility of the device demonstrated in the prototype;

[0041] - Causing an excessive amount of thermally conductive compound to flow into the area of the controlled surface, which is unacceptable when operating electrical equipment;

[0042] - Uneven heating of the entire volume of the substance, and a large value difference between the temperature of the controlled surface and the temperature of the top layer of the material, which is particularly obvious when recording short-term overheating.

[0043] Therefore, even if the bottom layer of the thermosensitive element close to the heating surface melts and changes color, the outer layer may still remain in its original state. This will affect the accuracy of recording the fact of temperature overrun and reduce the overall safety of the device operation.

[0044] It should also be noted that when the threshold temperature is reached, the crystals of the temperature-sensitive component will melt to form spherical droplets, and when the heating time is long enough and higher than the response temperature of the device, these droplets will diffuse, stick together and form larger droplets in the polymer binder. When the triggering device cools down, these enlarged spherical droplets solidify, and their total surface area, that is, the area of the phase boundary, will be significantly lower than that of the original material. This can ensure the transparency of the material after cooling. However, if the device detects short-term heating, during which the crystals of the thermosensitive component melt but do not have time to diffuse due to the slow diffusion process in the solid and viscous liquid, the adhesion and enlargement of the droplets will not occur. Therefore, when the device cools down, a large number of separate small spherical droplets will be observed in the material, and their surface area and the total area of the phase boundary will be slightly lower than the original state of the material before heating. This may lead to color reversal after activation, especially when cooling or being exposed to a temperature below the melting point of the thermosensitive component for a long time, the destruction of the color change contrast and false negative results.

[0045] Therefore, there is a need to create a device with high reliability, high response speed and high operational safety throughout its service life and manufacturing method to identify temperatures exceeding the threshold.

[0046] Terms and Definitions Used in This Group of Inventions

[0047] The term "opaque to at least part of the visible light" refers to a material that cannot transmit all or part of the visible light (380 - 760 nanometers).

[0048] "Microstructure" refers to the spatial arrangement of material particles or individual phases, with dimensions ranging from 1 to 100 micromillimeters, reflecting the shape and orientation of the constituent particles of the material. Different from chemical structure or nanoparticles, the microstructure only determines the physical, optical, and mechanical properties of the material, but does not affect the chemical properties of the substances that make up the microstructure. In the present invention, "irreversible change in microstructure" refers to an irreversible change in the physical, optical, or mechanical properties of the material relative to its initial state, accompanied by a change in the microstructure, that is, a change in the spatial arrangement, size, or shape of the material particles or individual phases, until the particles are completely fused to form a single phase.

[0049] The term "continuous solid phase" describes a material structure that contains solid material particles of any shape, where each particle is in contact with adjacent particles at least at one point, surface, or edge and is connected to each other such that every element of the solid phase can be connected to another element by a dotted line, and every point of the dotted line lies within the phase. In this case, the microstructure is not a continuous solid phase only when such a curve cannot be constructed. Depending on the shape and size of the solid particles, the continuous solid phase may have a honeycomb, granular, fibrous, crystalline, or flaky structure.

[0050] The term "continuous gas phase" refers to the voids within a solid that are interconnected through pores or channels.

[0051] "Flexible substrate" refers to a material that can change its shape under external influence and whose functional properties remain unchanged after returning to its original shape.

[0052] The term "threshold temperature" or "threshold temperature" (T) refers to the temperature value at which a sharp change occurs in the appearance of a thermosensitive material. For example, due to an increase in the transparency of one of its layers, a partial change in color occurs. In a specified set of inventions, the accuracy of recording the excess value of the threshold temperature does not exceed 5°C.

[0053] The meaning of the term "accuracy of recording the excess of the threshold temperature" is as follows:

[0054] 1. Until the device reaches a temperature equal to the threshold temperature of the corresponding thermosensitive material minus the declared accuracy value, there is no change in the transparency of the corresponding thermosensitive material or the appearance of the device.

[0055] 2. When the temperature is equal to or exceeds the threshold temperature of the corresponding temperature-sensitive material plus the declared accuracy value, the corresponding temperature-sensitive material is transparent, and the appearance of the device is different from the original.

[0056] 3. The exact value of the phase change of the temperature-sensitive element is within the declared range and has not been further determined. The accuracy of recording the excess of the threshold temperature determined in this set of inventions is 5°C.

[0057] The term "coverage" refers to the ability of a material to cover the color of the surface to which it is applied. In the case of application to the boundary between black and white areas, "coverage" is understood as the ability of the material to reduce the contrast between the specified areas of the surface until the visual difference between the areas completely disappears. In the present invention, the hiding power (D) of the thermosensitive material is measured by a method similar to the method described in GOST 8784-75 (Clause 1: Visual method for determining hiding power). The thermosensitive material is applied to a pre-weighed glass plate using the method described below and dried to a constant weight. Weighing is carried out with the required accuracy. The number of layers of the thermosensitive material is determined separately for each experiment. The mass of the thermosensitive material is calculated as the difference between the mass of the device and the mass of the glass plate. The glass plate with the thermosensitive material is placed on a contrast plate or checkerboard and observed in diffused daylight to see if the white and black areas are visible. The hiding power is reached when the brightness difference between the black and white areas of the plate completely disappears, and it is calculated as the ratio of the mass of the thermosensitive material (in grams) to the area of the layer of the thermosensitive material applied to the glass plate (in square meters).

[0058] "Apparent density" is the ratio of the mass of the dry material to its total volume, including the volume of voids formed in the material (according to GOST 2409-95). For the present group of inventions, the apparent density is determined as follows. A homogeneous sheet containing the thermosensitive element is cut out from the product. The mass and volume are determined with the required accuracy. For example, volume measurement can be carried out by measuring the linear dimensions with the required accuracy. Then the product is layered so as to remove the layer of the thermosensitive material, the layer of the thermosensitive material is removed mechanically, and the mass and volume of the remaining element are measured. The mass and volume of the thermosensitive material are calculated as the difference before and after removing the thermosensitive material. The apparent density is obtained by dividing the mass of the thermosensitive material by its total volume.

[0059] The term "porosity" in the thermosensitive material should be understood as the ratio of the volume of the gas phase to the total volume of the thermosensitive material, or the ratio of the cross-sectional area of the gas phase in a certain cross-section to the total cross-sectional area of the thermosensitive material. In the present group of inventions, the porosity can be obtained by any one of the following methods. The first method is based on observing the surface of the thermosensitive material using a scanning electron microscope. For this purpose, a uniform part containing the thermosensitive material is cut out from the finished product. Then, the protective layer is removed from this area to ensure the safety of the thermosensitive material. A part of the thermosensitive material without the protective layer is analyzed using a scanning electron microscope, which is equipped with software that can calculate the total outer surface area of the solid particles of the sample in a given material environment. The cross-sectional area of the gas phase is calculated by subtracting the total surface area of the solid particles from the area of the analyzed cross-section and then dividing by the area of the analyzed cross-section to obtain the porosity of the thermosensitive material in a certain cross-section. The measurement is carried out on 5 - 7 parts of the material, and the average value of the void ratio is calculated and expressed as a fraction. The second method is based on X-ray microtomography technology. The sample preparation is carried out in a similar manner to the first method. A known volume of the thermosensitive material part is analyzed using a laboratory digital X-ray tomograph and software that can calculate the percentage content of the gas phase in the given volume of the sample. The measurement is carried out on 5 - 7 parts of the material, and the average value of the void ratio is obtained and expressed as a percentage.

[0060] The term "shutter principle" refers to a specific microstructure of the thermosensitive material, in which the solid particles are mainly in the form of thin flakes, mainly parallel or perpendicular to the substrate to which the thermosensitive material is applied. The "open shutter principle" means that the arrangement of the solid particles is mainly perpendicular to the base layer to which the thermosensitive material is applied and the outer layer of the protective coating. However, the microstructure of this material cannot provide coverage of the base color. The "closed shutter principle" means that the direction of the solid particles is mainly parallel to the base layer and the protective coating. The microstructure of this thermosensitive material can provide a greater coverage of the base color at the same layer thickness.

[0061] In the present group of inventions, the term "glazing" is used, which represents the process of forming a uniform layer of another thermodynamic phase around the particles of one thermodynamic phase.

[0062] "Phase change" refers to the transformation of a substance from one thermodynamic phase to another when the external conditions change. In the context of the present group of inventions, the phase change can be melting, or other processes accompanied by the transformation of the substance from the solid state to the liquid state when heated above a given temperature.

[0063] "Complete isolation" means creating a protective layer to ensure the tightness of the device, prevent contact between the thermosensitive material and the environment, and protect the device from adverse external influences, including moisture, precipitation, splashes, industrial pollutants, mechanical shocks, etc. A "partial isolation" layer can also protect the device from adverse external factors, but it does not form an airtight seal for the device and maintains the atmospheric pressure in the gas phase within the volume of the thermosensitive material. Summary of the Invention

[0064] The object of the claimed group of inventions is to create a device for enhancing the safety of operation of various devices to reliably, accurately, and safely record cases where the temperature rises short-term and long-term above at least one threshold value, as well as variants of a method for manufacturing such a device.

[0065] More specifically, the claimed group of inventions was created to solve the following problems:

[0066] 1. Reliably visually record the fact that the temperature in individual local areas or the entire surface has exceeded at least one threshold temperature value;

[0067] 2. Increase the reliability of overheat detection recorded over a long time after startup under the actual operating conditions of the device and equipment;

[0068] 3. Provide the ability to record short-term overheating in order to detect defects that occur, for example, during short-term short-circuit current or pulsed overvoltage;

[0069] 4. Ensure the overall operating safety of various types of equipment equipped with a device for visually recording over-temperature.

[0070] The technical result of the claimed group of inventions is to improve the reliability and accuracy of visually recording the fact that the temperature has exceeded at least one threshold, make it impossible to restore the thermosensitive material to its original state, increase the response speed of the thermosensitive material, including under short-term peak loads or emergency operating modes of the device control elements, and improve the operating safety of the controlled device and the recording device itself throughout their entire service life.

[0071] The specific technical result in the first variant is achieved through a hierarchical structure of a device for visually recording a temperature rise above at least one threshold and the use of a thermosensitive material with a special microstructure. Generally speaking, the device can be described as having a hierarchical structure, including:

[0072] - A substrate that is opaque to at least part of the visible light, on the front surface of which an inscription indicating at least one numerical threshold temperature value is engraved;

[0073] - At least one thermosensitive material that is opaque to at least part of the visible light, applied to various parts of the substrate, the microstructure of which includes particles of solid organic substances and voids filled with a gas phase;

[0074] A transparent protective layer that partially or completely covers the front surface of the device;

[0075] Wherein, the device is designed to irreversibly change its appearance when at least one threshold temperature indicated thereon is reached due to the destruction of the microstructure of the corresponding thermosensitive material, accompanied by the fusion of solid organic matter particles, a decrease in the void ratio, an increase in transparency, and the appearance of the substrate color.

[0076] Compared with the technical solutions proposed in the prior art, the use of thermosensitive materials with voids can increase the service life and improve the reliability of overheat determination. This is because solid particles cannot aggregate through the gas phase, and the possibility of the material returning to its original state due to irreversible changes in the microstructure is eliminated. When melting the thermosensitive material containing pores, the original microstructure of the material will undergo irreversible changes, the apparent density of the material will increase, the proportion of pores will decrease, and at the same time, it is accompanied by the fusion of solid organic matter particles and the reduction of the "solid-gas" phase boundary area. This is due to the irreversible release of the gas contained in the pores to the surface and the stratification of the gas and non-gas environments. As a result, when further cooled, the solid organic matter will crystallize without voids, thereby irreversibly changing the transparency of the material to at least part of the visible light (increased relative to the initial state), producing a visual effect of changing the appearance of the device with high contrast, which ensures high reliability in recording temperature rises above the specified value.

[0077] Therefore, the device proposed by the present invention group is characterized by a complex operating principle, which not only includes melting the thermosensitive material, but also includes irreversible changes in the microstructure due to phase separation, fusion of solid organic matter particles, and a decrease in the void ratio in the material, which ensures that the material cannot return to its original state after subsequent cooling. In addition, when the material is kept at a low temperature and undergoes a long period of time with temperature changes, the specified changes are also irreversible.

[0078] In the study of thermosensitive materials with different porosities, it was found that compared with the thickness of the material layer without pores required to provide the same hiding power, an increase in porosity can significantly reduce the thickness of the thermosensitive material layer required to cover the background color (see Examples 11-12 on pages 50-55 of this specification). This is achieved through multiple refractions of light at the solid-gas interface. In the products according to the present invention group, the hiding power of at least one thermosensitive material is preferably not more than 50 g / m².

[0079] Therefore, high hiding power allows for the manufacture of devices with a minimum thickness, requiring the least amount of heat to change color, i.e., ensuring rapid and uniform heating of the material and its transfer to the melt, which increases the response speed of the thermosensitive material and provides the ability to record overheating with a minimum overheat value relative to the threshold or the shortest exposure time. In particular, even under short-term peak load conditions of the controlled unit or in emergency operation modes, it provides the ability to record overheating. Additionally, the minimum thickness of the product does not affect the performance, operational safety, and necessary heat dissipation of the controlled product, while ensuring the flexibility of the base, enabling it to closely conform to surfaces with complex shapes and avoiding cracks and material peeling in the base.

[0080] Furthermore, reducing the thickness of the thermosensitive material layer can eliminate the flow of excess material during the melting process, thus avoiding accidents such as short circuits, loss of electrical strength, heating, blockages, and fires.

[0081] In various embodiments of the present invention, the gas pressure inside the voids of the thermosensitive material can be equal to or lower than atmospheric pressure. When using a device with a pressure lower than atmospheric pressure, applying the force generated by atmospheric pressure to the material through the transparent protective layer can further increase the speed of irreversible changes in the microstructure, thereby increasing the response speed of the thermosensitive material.

[0082] The protective layer can also prevent adverse external factors: moisture, precipitation, splashes, industrial pollutants, and mechanical shocks. Preferably, the transparent protective layer covering the device is made of an elastic polymer material, which not only ensures protection from environmental influences and prevents the diffusion and flow of the thermosensitive compound after activation, but also ensures the sealing of the device and keeps the gas pressure inside the voids below atmospheric pressure before heating. The elasticity of the protective layer also provides the ability to mount the device on surfaces with complex shapes while maintaining the functional characteristics of the device.

[0083] Due to the special structure of the thermosensitive layer, its microstructure contains a large amount of gas phase. When the threshold temperature is exceeded, bubbles may form under the protective layer. If the gas pressure inside the voids of the thermosensitive material is equal to atmospheric pressure and the thermosensitive material layer is hermetically covered by a transparent protective layer, stratification of the gas and non-gaseous medium will occur when the microstructure of the thermosensitive material is damaged. Since this process occurs during heating, the volume of the generated bubbles will increase due to thermal expansion. As the device further cools, the volume of the gas environment decreases, and the size of the bubbles under the surface of the protective layer also decreases. The described process explains the necessity of using elastic materials during the manufacture of the device to maintain its integrity during operation within various temperature ranges. To eliminate the bubbles generated when the threshold temperature is exceeded, according to some variants of the present invention, a gap can be provided between the transparent protective layer and the substrate, or micropores can be provided on the protective layer, on the one hand ensuring that the gas released during operation can escape, and on the other hand ensuring the necessary protection of the thermosensitive material from external influences.

[0084] In the existing embodiments of the present invention, the air pressure inside the voids of the thermosensitive material is lower than the atmospheric pressure and has an airtight protective coating. When the threshold temperature is exceeded and subsequent cooling occurs, the formation of bubbles under the protective layer may not be observed. This is because the thermal expansion of the gas is compensated by the gas phase pressure inside the voids, which is lower than the atmospheric pressure in the initial state.

[0085] Preferably, in the microstructure of at least one thermosensitive material in the initial state, the particles of the solid organic substance are mainly oriented parallel to the plane of the surface of the substrate and the protective coating. In special cases, the solid organic matter can be in the form of scales, fibers, agglomerates thereof, etc.

[0086] Preferably, the void ratio of at least one thermosensitive material is reduced by at least 2 times relative to the initial state after being heated above the corresponding threshold temperature value, which additionally increases the contrast of the color change of the device when the threshold temperature value is exceeded. In this case, the apparent density of at least one thermosensitive material increases by 2.5 - 10 times relative to the initial state after being heated above the corresponding threshold temperature value.

[0087] The above characteristics of the microstructure of the thermosensitive material provide a large number of phase boundaries in the initial state compared to the analogues mentioned in the prior art, and when the corresponding threshold temperature value indicated on the device is reached, the color change has the maximum contrast, thereby enhancing the technical effect of the present invention.

[0088] In some embodiments, the solid organic substance is an organic substance that undergoes a phase change when the threshold temperature that differs from the temperature indicated on the device by no more than 5 °C is reached, accompanied by an irreversible increase in the transparency of the thermosensitive material. At this time, in order to achieve the filling of the solid organic matter particles required by the present invention, an organic compound containing one or more aliphatic hydrocarbon chains is preferably used. This is because such organic substances have a crystal packing structure in which the elongated structural fragments of linear hydrocarbons are oriented parallel to each other, thus ensuring the formation of mainly flat particles, such as scales or fibers (A.I. Kitaigorodsky, Molecular Crystals, Moscow: Nauka, 1971). This crystal packing results in the anisotropy of the solid organic substance and, consequently, the anisotropy of the microstructure of the thermosensitive material. As a result, the properties of the material in the direction parallel to the surface of the substrate and the protective coating are different from the properties of the material in the direction perpendicular to the surface of the substrate and the protective coating. The anisotropy of the microstructure characteristics of the thermosensitive material affects the strength of the material during bending and mechanical shock: applying an impact in a direction close to perpendicular to the surface of the substrate does not cause damage to the material (A.I. Kitaigorodsky, Organic Crystal Chemistry, Moscow, Academy of Sciences of the Soviet Union, 1955).

[0089] In a specific embodiment, the solid organic substances of the thermosensitive material are selected from the following groups: aliphatic fatty acids containing at least 13 carbon atoms; salts of fatty acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkyl phosphinic acids containing at least 16 carbon atoms; amides of aliphatic acids containing at least 3 carbon atoms; fatty acid anhydrides containing at least 22 carbon atoms; fatty alcohols containing at least 16 carbon atoms; aliphatic amines containing at least 17 carbon atoms; nitriles of fatty acids containing at least 20 carbon atoms or mixtures thereof. The melting point of a specific solid organic substance determines the threshold temperature of the corresponding temperature-sensitive material of the device. Therefore, when selecting the organic substance, it should be ensured that its melting temperature is equal to the threshold temperature of the device with a given accuracy. In this case, the number of carbon atoms in each type of organic substance is determined according to the specific practical problems to be solved by the device declared for use (device type, steps required to determine the overheating temperature, test surface area for heating, etc.).

[0090] Another factor determining the selection of solid organic substances as thermosensitive materials is the commercial availability of these substances. Therefore, using organic substances that are not easily obtainable on an industrial or semi-industrial scale may not be commercially feasible, even if these substances may meet other requirements. Preferably, the aliphatic fatty acids used as solid organic substances contain no more than 22 carbon atoms; the salts of aliphatic fatty acids have no more than 66 carbon atoms; the alkanes contain no more than 40 carbon atoms; the dialkyl phosphinic acids contain no more than 20 carbon atoms; the fatty acid amides contain no more than 22 carbon atoms; the fatty acid anhydrides contain no more than 26 carbon atoms; the fatty alcohols contain no more than 32 carbon atoms; the aliphatic amines contain no more than 22 carbon atoms; the nitriles of fatty acids contain no more than 22 carbon atoms.

[0091] In a specific case, the solid organic substances of the thermosensitive material are selected from: palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearyl alcohol, cetyl alcohol, dispersed polyethylene, saturated fatty carboxylates of rare earth metals (especially lanthanum, yttrium, ytterbium, scandium).

[0092] In special cases, the microstructure of at least one thermosensitive material further comprises a polymer binder that is transparent to at least part of visible light, and the phase transition temperature of the polymer binder is higher than that of the solid organic substance. In this case, the thermosensitive material contains a phase boundary "solid-solid-gas", and during the melting process, the microstructure of the material also undergoes irreversible changes. As a result, due to the release of the gas contained therein to the material surface and the stratification of the gas and non-gas environments, the number of voids decreases relative to the initial state. As a result, a decrease in the contact area between the solid phase and the voids, i.e., a decrease in the phase boundary area, is observed. During the process of leaving to the surface, the gas filling the voids ensures a higher diffusion process rate in the solid and viscous liquid than in the "solid-solid" system, which not only accelerates the change in the transparency of the thermosensitive material but also ensures the irreversibility of this change after cooling. In addition, the irreversible change in the microstructure of the thermosensitive material may be accompanied by the formation of a new thermodynamic phase, such as a solid solution. Preferably, the content of the polymer binder in the thermosensitive material is 1-30 wt%. In special cases, the polymer binder covers each individual structural particle of the solid organic substance, providing it with a "glaze". When selecting the binder, it should be ensured that the solid organic matter particles in the polymer binder have wettability but do not dissolve. Therefore, when "glazing" the grains, crystals, fibers, flakes or aggregates of the above particles, additional gas capture occurs, and in this environment, the thermosensitive material is formed and distributed between the "glazed" particles of the solid organic substance through the binder. The given features ensure the existence of a material microstructure with an increased number of phase boundaries, thereby enhancing the technical effect of the present invention.

[0093] In specific cases, the transparent polymer binder is selected from 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, polyisobutene, 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, polyoxyethylene or a mixture thereof.

[0094] These devices can be various types of products designed to be firmly connected and closely fitted to the surface of the controlled device, including industrial, household and energy devices.

[0095] In a preferred embodiment of the invention group, the device may be a sticker, comprising an insulating layer, an adhesive layer, an elastic substrate that is opaque to at least part of visible light, the elastic substrate being made of a halogen-containing polymer, having a thickness of less than 1 mm, a dielectric strength of at least 5 kV / mm, at least one thermosensitive material applied to various parts of the substrate, having a thickness not exceeding 800 microns, and the thermosensitive material in the transparent protective layer being designed such that when the corresponding threshold temperature indicated on the sticker is reached, the transparency may undergo an irreversible change in less than 5 seconds.

[0096] Using a halogen-containing polymer substrate, such as polyvinyl chloride, enables the use of the claimed device to visually record the overheating temperature on the surface of the conductive elements of electrical equipment, since the substrate has dielectric properties and is flame-resistant. The device is designed with an elastic substrate having a thickness of less than 1 mm, which can adhere tightly to surfaces with complex geometries, including the conductive elements of electrical equipment. Additionally, with a substrate having a thickness of less than 1 mm and a thermosensitive material layer having a thickness not exceeding 800 microns, the thermosensitive material can be quickly heated during short-term overheating and completely transformed into a melt with an "opaque - transparent" color change within no more than 5 seconds, while also ensuring necessary heat transfer during the air cooling of the operating equipment. The response speed of the thermosensitive material when heated above the corresponding threshold temperature is less than 5 seconds, which can record short-term emergency overheating caused by the passage of starting current or short-circuit current, excessive starting load of the motor, cold operation, switching, or other processes. Moreover, due to the low heat dissipation of the substrate and the thermosensitive material on the plane of the controlled surface, and the small thickness of the device, local overheating of the surface can be accurately detected when using stickers with a relatively large area of the thermosensitive layer.

[0097] In other embodiments of the invention group, the device may be in the form of an elastic hollow tube (hose) or in the form of a tube including a longitudinal part (clip) for fixing to an electric wire, the surface of which serves as the substrate, being opaque to at least part of visible light, made of a halogen-containing polymer, having a thickness of less than 1 mm, a dielectric strength of at least 5 kV / mm, and at least one thermosensitive material having a thickness not exceeding 800 microns is applied to various parts of its front surface, covered with a transparent protective layer, where the thermosensitive material may undergo an irreversible change in transparency in less than 5 seconds when the corresponding threshold temperature indicated on the tube is reached.

[0098] Different from the sticker, the clip or hose is more convenient to install on small-section electric wires in the electrical panels of buildings and structures.

[0099] To improve the visibility of the device itself and the fact of its operation, and thus further enhance the safety of device operation, the base may have reflective or luminous properties.

[0100] In other embodiments of the device, by making the surface area of the substrate at least 100 square millimeters and covering it with at least one thermosensitive material, the accuracy of determining local overheating on the surface of an electrical device can be improved.

[0101] In an embodiment, when locally heating a controlled surface, only the transparency of the area in the thermosensitive material that is heated above the threshold temperature changes, which enables recording of point overheating.

[0102] This technical result is also achieved by a variant of the method for manufacturing a device for visually recording temperatures exceeding at least one threshold. The disclosed variant is not restrictive, and other methods can be used to manufacture the device, ensuring production of a thermosensitive material having the microstructure disclosed in the material.

[0103] In a first embodiment, the method for manufacturing a device for visually recording a temperature increase exceeding at least one threshold includes the following steps:

[0104] - Applying one or more layers of at least one suspension to respective parts of an opaque substrate, the suspension consisting of solid organic matter particles with a boiling point below 180 °C, and the solubility of the solid organic matter particles in the liquid phase not exceeding 10 grams per kilogram;

[0105] - Removing the liquid phase from the applied layer of the suspension of solid organic matter particles in the liquid phase to form a thermosensitive material that is opaque to at least part of visible light, the microstructure of which includes solid organic matter particles and voids filled with a gas phase;

[0106] - Covering the front surface of the workpiece with a transparent protective layer,

[0107] where at least one of the above stages is carried out at a pressure below atmospheric pressure.

[0108] In this embodiment, by using reduced pressure (pressure below atmospheric pressure) in at least one stage, rapid removal of the liquid phase is ensured, similar to boiling, and as a result, additional foaming of the material is observed, leading to an increase in the number of voids. In this case, when using a pressure below atmospheric pressure in one of the stages, in other stages, the liquid phase is removed from the applied layer of the suspension of solid organic matter particles in the liquid phase at atmospheric pressure.

[0109] In a preferred embodiment of the method for manufacturing the device, a subatmospheric pressure is used in the stage before applying the transparent protective layer, or in the stage of applying at least one suspension of at least one solid organic matter particle layer by layer in the liquid phase after removing the liquid phase from each individual layer. When manufacturing the device using this method, the pressure below atmospheric pressure is preferably 1 - 650 mmHg. The selected pressure value and the holding time of the device blank at the given pressure depend on the boiling point of the liquid phase, the amount of the liquid phase used to prepare the suspension, and the nature of the solid organic matter.

[0110] After applying each layer of the solid organic matter suspension in the liquid phase, a pressure below atmospheric pressure can be generated immediately. In this case, the formation of the microstructure including solid organic matter particles and voids filled with the gas phase occurs layer by layer. In another embodiment of the method, a pressure below atmospheric pressure can be generated at the stage of removing the liquid phase from the required number of applied layers of the solid organic matter suspension in the liquid phase. In this case, the liquid phase will spontaneously release from the entire material volume, forming a large number of unstructured voids. In the third version of the method, the front surface of the workpiece is coated with a transparent protective layer under a pressure below atmospheric pressure. When using a sealed protective layer, this ensures that the pressure inside the voids of the thermosensitive material in the final product is below atmospheric pressure. In addition, generating a pressure below atmospheric pressure at this stage can remove the residual liquid phase enclosed by the thermosensitive material, and since the residual liquid phase will suddenly evaporate during the process of generating a pressure below atmospheric pressure, this will cause additional foaming of the material, resulting in an increase in the number of voids.

[0111] The generation of a pressure below atmospheric pressure can be carried out at any two stages of device manufacturing, or at all three stages of device manufacturing, depending on the nature of the solid organic matter, the liquid phase used, and the concentration of the solid organic matter in the suspension, to ensure the formation of the required microstructure of the thermosensitive material.

[0112] In addition, when manufacturing a device using this method, the particles of the solid organic matter can be made in the form of scales, fibers, granules, crystals, or aggregates of the said particles.

[0113] In the second variant, the method for manufacturing a device for visually recording a temperature rise exceeding at least one threshold includes performing at least 3 cycles, each cycle including applying at least one layer of a suspension of solid organic matter particles in a liquid phase to respective parts of an opaque substrate, and removing the liquid phase from the applied suspension layer, and subsequently coating the front surface of the workpiece with a transparent protective layer, wherein the boiling point of the liquid phase is below 180 °C, and wherein the suspension of solid organic matter particles in the liquid phase is applied by a method selected from: screen printing, flexographic printing, pad printing, screen printing, while generating a microstructure of at least one thermosensitive material, and wherein the particles of the solid organic matter are mainly oriented parallel to the plane of the substrate surface.

[0114] In this variant, after applying a suspension of at least one liquid-phase solid organic matter particle for the first layer, the workpiece is dried at room temperature to a constant weight, and then the process of applying layer by layer and removing the liquid phase from the applied suspension layer is repeated at least three times until the desired coating thickness is obtained. In certain cases, when applying a suspension of at least one solid organic matter particle in a liquid phase layer by layer to various parts of an opaque substrate, methods such as screen printing, flexographic printing, pad printing, or screen printing are used. By alternately cycling the application and removal of the liquid phase from the applied suspension layer, the necessary orderliness of the solid organic matter particles on the substrate can be ensured. Since the liquid phase spontaneously removes from the applied suspension layer at room temperature, the scale and its fillers are ensured to settle slowly in a thermodynamically favorable state. In this way, a layer of thermosensitive material is formed, in which the particles of the solid matter in the microstructure are mainly parallel to the substrate surface. To ensure the required hiding power, the cycle of applying and removing the liquid phase from the applied suspension layer is repeated at least three times until a thermosensitive material that is opaque to at least part of the visible light is obtained.

[0115] In this case, when manufacturing a device using this method, the particles of the solid organic matter are mainly made in the form of scales, fibers, crystals, or aggregates of said particles, or other particles having a linear dimension exceeding the thickness.

[0116] In an embodiment of the method for manufacturing a device according to the invention claimed, the thickness of the thermosensitive material preferably does not exceed 800 micromillimeters, preferably does not exceed 450 micromillimeters, and most preferably does not exceed 150 micromillimeters.

[0117] Preferably, when implementing the method for manufacturing the device, a suspension including solid organic matter particles measuring 2 - 3 micromillimeters in the liquid phase is used. The density difference between the liquid phase and the solid organic matter is preferably less than 0.2 g / cm³. For this purpose, the liquid phase can be selected from: isopropyl alcohol, water, methanol, 1-propanol, isobutanol, ethylene glycol monomethyl ether, 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 a mixture thereof, but not limited thereto.

[0118] The relative density difference between the solvent and the solid fusible substance particles is an important factor affecting the sedimentation rate and properties of solid organic matter particles. If the density difference is large (more than 0.2 g / cm³), the solid organic matter particles will settle out of the suspension too quickly, resulting in the formation of longitudinal and transverse structures of the particles, which are randomly oriented with respect to the substrate plane. In this case, the substrate will be visible through the transverse structure with the same layer thickness, while the covering power will be achieved through the longitudinal arrangement. Therefore, only the longitudinally arranged particles can provide the required covering power. When the densities are equivalent or the density difference is less than 0.2 g / cm³, slow sedimentation of the solid organic matter particles will be observed, while the necessary ordered microstructure of the material is formed, and the particles are mainly longitudinally arranged with respect to the substrate surface.

[0119] To ensure safety when using the device claimed according to the present invention in the energy field, for example, for visually recording overheating of the surface of conductive elements of electrical equipment, in a variant of the method of manufacturing the device, a halogen-containing polymer substrate, such as polyvinyl chloride, is used as the substrate because it has flame resistance and dielectric properties. The possibility of using the stated device is provided because the specified base is also flame resistant.

[0120] In an embodiment of the claims of the method of manufacturing the device, a substance selected from the substance categories listed on page 33 of this specification can be used as the solid organic substance. Description of the Drawings

[0121] The present invention can be better understood from the following description, which is not restrictive in nature and is given with reference to the accompanying drawings, in which:

[0122] Figure 1 - Various versions of the device for visually recording a temperature rise above at least one threshold temperature value: 1a - tubular, including a longitudinal part (clip) for fixing to an electric wire, with a kind of thermosensitive material; 1b - in the shape of an elastic hollow tube (linen) for placing on an electric wire, with three different thermosensitive materials; 1c - in the shape of a sticker, with four different thermosensitive materials.

[0123] Figure 2 - The layered structure of the device for visually recording overheating: 2a - when above more than one threshold temperature, with a sealed transparent protective layer; 2b - when above one to three different threshold temperatures, with a transparent protective layer, where there is a gap between the protective layer and the substrate; 2c - when above one to four different threshold temperatures, with a transparent protective layer, where there are micropores.

[0124] Figure 3- Device for visually recording a temperature rise above at least one threshold temperature value: 3a - Initial view of a device in the form of a sticker with a thermosensitive material, 3b - Trigger view of a device in the form of a sticker with a thermosensitive material (after exceeding the threshold temperature value), 3c - Initial view of a device in the form of a sticker with three different thermosensitive materials, 3e, d - Partially triggered sticker after exceeding the threshold temperature values of the first (3e) and second (3d) thermosensitive materials, 3e - Fully triggered sticker after exceeding the threshold temperature value of the third thermosensitive material, 3e - Initial view of a device in the form of a sticker with a substrate having reflective or luminescent properties and four different thermosensitive materials, 3z - Fully triggered sticker with a substrate having reflective or luminescent properties and a "white - black" visual color change after exceeding the threshold temperature value of the fourth thermosensitive material, 3i - A layered structure A device for visually recording excess temperature with four different thermosensitive materials, using a substrate with reflective or luminescent properties, applying a black coating to the thermosensitive material area, and forming a microporous transparent protective layer thereon.

[0125] Figure 4 - Microstructure of thermosensitive material without binder before (4a) and after (4b) activation, where the particles are scaly and their aggregates; scale and its aggregates with binder, before (4c) and after (4d) activation; fiber without binder and its aggregates, before (4d) and after (4e) activation.

[0126] Figure 5 - Device for visually recording the exceeding of a temperature threshold in case of local overheating: 5a - Original appearance of the device, 5b - Partially activated device after point - heating the controlled surface to exceed the temperature threshold, where only the transparency of the area of the thermosensitive material heated above the threshold temperature changes, while the opaque area of the material remains in its remaining unheated area.

[0127] Figure 1 Various embodiments of a device for visually recording a temperature increase above at least one threshold temperature value are shown, which are a tube including a longitudinal part (clip) (1a) for fixing to an electric wire, having one temperature - sensitive material 1, an elastic hollow tube (linen) (1b) for fixing to an electric wire, having three different temperature - sensitive materials 1, or a sticker (1c) having four different temperature - sensitive materials 1 and an inscription - inserted label 2, including the numerical value of the recorded temperature.

[0128] Figure 2Shows the hierarchical structure of a device for visually recording a temperature increase above more than one threshold temperature value: (2a), including a flexible substrate 3 with a thickness of d, a thermosensitive material 1 with a thickness of D applied thereon, and a transparent protective layer 4 closely attached to the substrate and the material, ensuring the tightness of the device and the ability to maintain a pressure below atmospheric pressure; the hierarchical structure of a device for visually recording a temperature increase above one to three different temperature threshold values (2b), including a flexible substrate 3 and a thermosensitive material 1 applied thereon, a transparent protective layer 4 closely attached to the substrate and the material, and having a gap 5a between the protective layer and the substrate; the hierarchical structure of a device for visually recording a temperature above one to four different temperature threshold values (2c), including a flexible substrate 3 and a thermosensitive material 1 applied thereon, a transparent protective layer 4 closely attached to the substrate and the material, and having micropores 5b on its front surface.

[0129] Figure 3 Shows a device for visually recording a temperature above more than one threshold temperature value in the form of a sticker, the device being in the initial state (3a) before heating and the state (3b) after heating above the threshold temperature value, including a flexible substrate 3, a thermosensitive material 1 applied thereon, and an inscription 2 including the numerical values of the recorded temperature thresholds; a device for visually recording above one to three different threshold temperature values when in the initial state before heating (3c), after heating above the first threshold temperature value (3e), after heating above the second threshold temperature value (3d), and after heating above the third threshold temperature value (3e), including a flexible substrate 3, a thermosensitive material 1 applied thereon, and an inscription 2 including the numerical values of the threshold temperature values recorded for each thermosensitive material; a visual recording device for the temperature after heating above the fourth temperature threshold (3z) in the initial state before heating (3e), and the layered structure (3i) of the device, including a flexible substrate 6 with reflective or luminescent properties, a thermosensitive material 1 applied thereon, and an inscription 2, the inscription including the numerical values of the temperature thresholds recorded for each thermosensitive material, a black coating 7 applied to the flexible substrate in the area below the thermosensitive material, and a transparent protective layer 4 closely attached to the substrate and the material, and having micropores 5b on its front surface.

[0130] Figure 4The microstructure of the binder-free thermosensitive material 1 is shown, where the particles 8 are in the form of scales and their aggregates, and there are voids 9. Before heating (4a), and after heating above the threshold temperature, the proportion of voids decreases, the apparent density increases, and the particles melt and lose their original shape in the microstructure of the thermosensitive material 1 (4b); before heating, the microstructure of the thermosensitive material 1 containing the binder 10, where the particles 8 are in the form of cells and their aggregates, and there are voids 9 (4c); after heating above the threshold temperature, the microstructure of the thermosensitive material 1 containing the binder 10, where the proportion of voids decreases, the apparent density increases, and the particles melt and lose their original shape (4d); before heating, the microstructure of the binder-free thermosensitive material 1 is fibrous particles 8 and voids 9 in the form of their aggregates (4d); after heating above the threshold temperature, the microstructure of the thermosensitive material 1 is such that the proportion of voids decreases, the apparent density increases, the particles melt and lose their original shape (4e).

[0131] Figure 5 A device for visually recording the exceedance of the threshold temperature value during local overheating is shown, including a flexible substrate 3 and a thermosensitive material 1 applied thereto. Before heating (5a) of the controlled surface and after point heating (5b), as a result, only the transparency of the region 11 of the thermosensitive material 1 heated above the threshold temperature changes, while maintaining the original state of the remaining regions of the thermosensitive material 1. Detailed description

[0132] Preparation of the thermosensitive substance.

[0133] The solid organic substance of at least one thermosensitive material can be selected from at least one of the following categories of organic substances: aliphatic fatty acids containing at least 13 carbon atoms; salts of fatty acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkyl phosphinic acids containing at least 16 carbon atoms; amides of aliphatic acids containing at least 3 carbon atoms; fatty acid anhydrides containing at least 22 carbon atoms; fatty alcohols containing at least 16 carbon atoms; aliphatic amines containing at least 17 carbon atoms; nitriles of fatty acids containing at least 20 carbon atoms or mixtures thereof.

[0134] Preferably, the aliphatic fatty acids used as the solid organic substance contain no more than 22 carbon atoms; the salts of aliphatic fatty acids have no more than 66 carbon atoms; the alkanes contain no more than 40 carbon atoms; the dialkyl phosphinic acids contain no more than 20 carbon atoms; the fatty acid amides contain no more than 22 carbon atoms; the fatty acid anhydrides contain no more than 26 carbon atoms; the fatty alcohols contain no more than 32 carbon atoms; the aliphatic amines contain no more than 22 carbon atoms; the nitriles of fatty acids contain no more than 22 carbon atoms.

[0135] In a particular embodiment of the present invention, the solid organic substance of at least one thermosensitive material is selected from at least one of the following substances: yttrium hexanoate, yttrium behenate, yttrium undecanoate, yttrium laurate, tridecane laurate, tridecane pentadecanoate, yttrium tridecanoate, pentadecanoic acid yttrium, yttrium palmitate, ytterbium octanoate, lanthanum palmitate, lanthanum nonadecynoate, lanthanum hexanoate, erbium undecanoate, zinc nonadecanoate, zinc palmitate, zinc hexanoate, zinc myristate, zinc stearate, cadmium laurate, cadmium laurate myristate, lead hexanoate, lead stearate, lead laurate, lead laurate, copper stearate, stearic acid ester, lithium stearate, stearic acid, lauric acid, docosanoic acid, eicosanoic acid, crotonic acid, arachidic acid, myristic acid, palmitic acid, adipic acid, octanoic acid, decanoic acid, tricosanoic acid, triacontanoic acid, 2,3-dimethylnonanoic acid, rutic acid, 2-methyl-2-dodecenoic acid, eleostearic acid, behenic acid, behenic acid, oleamide, stearamide, lauramide, erucamide, decanamide, myristamide, octanamide, palmitanilide, salicylanilide, β-naphthamide, hexanoic acid, heptanoyl hydrazide, hexanamide, octacosylamide, N-methylheptacosylamide, salicylamide, cetyl alcohol, decanamide, 1-docosanol, trilaurate, tricosylamine, dioctadecylamine, N,N-dimethyloctylamine, dioctylphosphinic acid, triacontane, tetracosane, stearyl alcohol, cetyl alcohol, dispersed polyethylene, stearyl chloride, palmitic anhydride, stearic acid and acetic anhydride, lauric anhydride or a mixture thereof.

[0136] In various embodiments, the melting temperature of the solid molten substance of each thermosensitive material can be in the range of 50 - 210 °C. Among them, the numerical value of the threshold temperature of at least one thermosensitive material is selected from the group of 50 °C, 55 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C.

[0137] To produce the thermosensitive material, the solid organic substance is ground in a ball mill to a size of 2 - 3 microns, and the liquid phase is added successively, represented by water or an organic solvent with a boiling point below 180 °C, and the resulting suspension is stirred, while mainly ensuring the periodic dispersion of the mixture by air inlet during this period until a constant density of the mixture is obtained. The liquid phase is preferably water or an organic solvent in which the solubility of the solid organic substance does not exceed 10 g / kg.

[0138] In a preferred embodiment of the present invention, the addition amount of the liquid phase is 50 vol.% to 90 vol.%.

[0139] The density difference between the liquid phase and the solid organic matter is preferably less than 0.2 g / cm³. For this purpose, the liquid phase may be selected from: isopropanol, water, methanol, 1-propanol, isobutanol, ethylene glycol monomethyl ether, 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, but is not limited thereto.

[0140] Using this production method, the obtained thermosensitive material consists of two continuous phases: solid and gas.

[0141] The thermosensitive material obtained at this time is opaque to at least a part of visible light in the initial state. When heated above the corresponding threshold temperature, the microstructure of the corresponding thermosensitive material undergoes irreversible changes, accompanied by the fusion of solid organic matter particles, a decrease in the void ratio, an increase in transparency, and the appearance of the color of the substrate. When subsequently cooled, the transparency of the thermosensitive material does not return to its original value.

[0142] Depending on the properties of the solid organic matter, the obtained solid organic matter particles may be particles, crystals, fibers, flakes or aggregates of the particles.

[0143] In some embodiments of the present invention, the ground solid organic matter is suspended in a liquid phase binder solution that is transparent to at least a part of visible light. In a preferred embodiment of the present invention, the content of the binder in the obtained thermosensitive material is 1-30% by weight to provide a glazing effect on the solid organic matter particles.

[0144] In this case, the transparent polymer binder is selected from: phenolic 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, polyisobutene, 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, poly(ethylene oxide) or mixtures thereof, but is not limited thereto.

[0145] In this case, the thermosensitive material contains a "solid-solid-gas" phase boundary; during the melting process, the microstructure of the material also undergoes irreversible changes, and the number of voids decreases relative to the initial state due to the release of the gas contained in the voids to the surface of the material and the stratification of the gas and non-gas environments.

[0146] The resulting suspension contains no binder or contains a binder and is used immediately after receipt.

[0147] Select the device base

[0148] The claimed device can be designed in the form of a sticker, a clip, or a fine linen, or other devices that can firmly adhere and closely stick to the surface of the controlled device.

[0149] The device has a layered structure, including: a substrate, a substrate that is opaque to at least part of the visible light, at least one thermosensitive material applied to the surface of the substrate, and a transparent protective layer that partially or completely isolates the thermosensitive material from the environment.

[0150] In the case of the clip and the fine linen, the outer surface of the tube including the longitudinal part or the outer surface of the elastic hollow cylinder respectively serves as the substrate that is opaque to at least part of the visible light.

[0151] The thickness of the device substrate is preferably less than 1 mm to ensure that the response speed of each temperature-sensitive material when heated above the corresponding threshold temperature is less than 5 seconds.

[0152] The bases of different types of devices can be selected from the following materials: OraJet 3106SG, 3951PVC film, 3981RA polyurethane film, 3M polyester film: 7874E or WHITEV TC 50 / RC20 / HD70WH self-adhesive paper film, ORALITE5500 methyl methacrylate film, but not limited to these. When using a halogen-containing polymer substrate, especially PVC, the dielectric strength of the device is preferably at least 5 kV / mm, which is preferred when using the device in electrical engineering.

[0153] In some embodiments, a pattern for marking the phase or unit of an electrical device can be applied to the surface of the base, including graphic, digital, or text information, and the base itself can have reflective or luminescent properties to increase the visibility of the device itself and the facts of its operation, thereby further improving the safety of device operation.

[0154] To increase the contrast of the color transition, the base of at least one thermosensitive material region is colored, such as black. In this case, the thermosensitive material is preferably white, thus ensuring a visually "white-to-black" transition when at least one thermosensitive material is triggered.

[0155] Manufacture a device for visually recording a temperature increase above at least one threshold value.

[0156] Generally, the process of manufacturing the device includes the following steps: applying a suspension of at least one solid organic material particle in a liquid phase to one or more layers on various parts of an opaque substrate, removing the liquid phase from the applied layer of the applied suspension, and covering the front surface of the workpiece with a transparent protective layer.

[0157] In order to obtain the microstructure of the applied thermosensitive material, ensure that an irreversible change in appearance occurs when the threshold temperature is reached, accompanied by the melting of solid organic matter particles, a reduction in the void ratio, an increase in transparency, and the appearance of the substrate color. In particular, the following techniques can be used in the previously disclosed stages of the method:

[0158] - At least one of the above steps of the method (applying a suspension of solid organic material particles in a liquid phase, removing the liquid phase from the applied suspension layer, covering the front surface of the workpiece with a transparent protective layer) is carried out under a pressure lower than atmospheric pressure.

[0159] - Carry out at least 3 cycles of applying at least one layer of a suspension of solid organic material particles in a liquid phase and removing the liquid phase from the applied suspension layer. Among them, the suspension of solid organic material particles in a liquid phase is applied by a method selected from: screen printing, flexographic printing, pad printing, screen printing, to produce a microstructure of at least one thermosensitive material, in which the particles of the solid organic material are mainly oriented parallel to the plane of the substrate surface.

[0160] According to the selected device manufacturing method, the liquid phase can be removed from the applied layer of the suspension of solid organic matter particles in the liquid phase or separately from each layer, and it can be carried out under a pressure lower than atmospheric pressure or at atmospheric pressure.

[0161] In the specific case of the device, the sub-atmospheric pressure can be used both immediately after applying each layer of the suspension of solid organic matter in the liquid phase and during the drying (i.e., removal of the liquid phase) stage, which requires applying the required number of layers of the suspension of solid organic matter in the liquid phase. In this case, the liquid phase is spontaneously released from the material volume (successively from each layer or from the entire material volume), while forming a large number of unstructured voids. In other words, when using sub-atmospheric pressure, the liquid phase is rapidly removed, similar to boiling, which causes further foaming of the material, resulting in an increase in the number of voids. In addition, during the stage of applying the protective sealing layer, sub-atmospheric pressure can be used. This not only prevents the formation of bubbles on the surface of the protective layer when the device is triggered, but also ensures the removal of the residual liquid phase blocked by the thermosensitive material, while increasing the foaming and the number of voids of the material. In this case, after applying the last layer, the device is dried by choosing the method of removing the liquid phase from the applied suspension layer, preferably at a temperature of (20 ± 2) °C for at least 1 hour, and only after that is the sub-atmospheric pressure used and the protective layer is applied.

[0162] The application of sub-atmospheric pressure can be carried out at any two stages of device manufacturing or at all three stages of device manufacturing, and in this way, a thermosensitive material with the required microstructure can also be obtained.

[0163] The production of the claimed device can also be ensured by applying layer by layer a suspension of solid organic substances in a liquid phase. In this case, after applying at least one thermosensitive material, the device is dried by choosing a way to remove the liquid phase from the applied suspension layer, preferably dried in an air atmosphere at a temperature of (20 ± 2)°C for 10 minutes, and then the layer-by-layer application procedure is repeated until the desired coating thickness is obtained. The formation of the microstructure occurs layer by layer, including solid organic matter particles and voids filled with a gas phase. The layer-by-layer application is preferably carried out while maintaining at room temperature between steps to ensure the necessary orderliness of the particles of the solid fusible substance when placed on the device. When the particles of the solid fusible substance are flakes, in order to achieve hiding power with a minimum layer thickness, it is preferable to arrange them "overlapping" longitudinally on the flexible substrate of the device. In this case, the scales will be arranged like closed shutters, and a thin layer of scales will be sufficient to cover the background color ("closed shutter principle"). Since the liquid phase spontaneously removes from the applied suspension layer at room temperature, it ensures the slow sedimentation of the scale and its filler in a thermodynamically favorable state. When preparing the thermosensitive material using the method shown, it is observed that a continuous solid phase of the solid organic matter is mainly formed, while the voids filled with gas form a continuous gas phase. When the liquid phase is forcibly removed from the applied suspension layer by heating or blowing, the kinetic process of solvent evaporation will take precedence over the thermodynamic ordering of the solid organic matter particles, and as a result, the flakes will form a structure that is not longitudinal but transverse ("open shutter principle"), through which the substrate of the same layer thickness can be seen, and when the closed shutter principle is observed, hiding power will be achieved.

[0164] This ordering can also be achieved by using a dilute suspension (dilution greater than 50%) of solid fusible particles in a liquid phase, because compared with using a more concentrated suspension, the phenomenon of the scales arranged in the desired way and their sedimentation in an ordered form will occur in large numbers. In addition, the high dilution ensures an extended process of spontaneous evaporation of the liquid phase, during which the laying of the scales will also proceed according to the principle of the closed shutter. Another factor affecting the sedimentation rate and properties of the solid organic matter particles is the relative density difference between the solvent and the particles of the solid fusible substance. If the density difference is large (exceeding 0.2 g / cm²), the solid organic matter particles will precipitate out of the suspension too quickly like an open shutter. When the densities are comparable or the density difference is less than 0.2 g / cm³, slow sedimentation of the solid organic matter particles will be observed, while forming the necessary ordered microstructure of the material and following the closed blind area principle.

[0165] Therefore, by following the open blind area principle when forming the microstructure of the thermosensitive material, a material can be obtained whose microstructure has a preferential orientation of solid particles parallel to the surface of the substrate and the protective coating in the initial state.

[0166] Preferably, a suspension layer of solid organic matter in a liquid phase is applied by a method selected from screen printing, flexographic printing, pad printing or screen printing.

[0167] Flexographic printing involves capturing the suspension by an anilox roll and transferring it to the raised portions of a relief printing plate, thereby coating the plate with a thin layer of the suspension, which is then transferred to a substrate. In this case, at the stage when the anilox roll captures the suspension, an ordered arrangement of particles mainly parallel to the surface begins to form; when the suspension is transferred to the raised portions of the printing plate, the suspension layer thins, facilitating further sorting of the particles, and when the suspension is transferred to the substrate, the sorting process is completed, ensuring that the solid organic matter particles are arranged according to the "closed pore" principle. When pad printing is implemented, a pad printing pad or cylinder is used to transfer the solid organic matter suspension into the liquid phase, and according to the "closed pore" principle, the solid organic matter particles also begin to form on the liquid phase. Applying to the substrate completes the sorting process to obtain the microstructure required for the thermosensitive material.

[0168] Both screen printing and screen printing are achieved using a screen printing stencil or matrix, which is a fine mesh made of monofilament polyester, polyamide or metal wire. In this case, a rubber squeegee is used to press the suspension of solid organic matter in the liquid phase through the grid onto the substrate, so that the particles of the solid organic matter are parallel to the substrate surface. According to the "closed shutter" principle, by repeatedly rolling the rubber squeegee on the grid, most of the solid organic matter particles can be oriented.

[0169] The above effects apply to embodiments of devices in which the microstructure of the thermosensitive material is represented by solid organic matter, the particles of which are mainly in the form of scales, crystals or fibers, i.e., the linear dimensions of these particles exceed their thickness. In this case, the formation of aggregates (aggregates) of individual particles (flakes, crystals or fibers) of solid organic matter can be observed.

[0170] In the case of using a thermosensitive material containing solid organic matter, a binder and voids, a suspension of finely divided solid organic matter in a binder solution in a liquid phase is used to prepare the thermosensitive material. When the liquid phase evaporates, the binder precipitates on the solid organic matter particles and covers their surface with a thin and uniform layer. In this case, "glazing" occurs both on individual solid organic matter particles and on the resulting particle aggregates.

[0171] When applying a suspension of solid organic matter particles in a liquid phase, the area of the front surface of the device base is sealed with a polyethylene film, and this area should not be exposed to at least one thermosensitive material. A suspension layer of at least one solid organic matter particle in a liquid phase is uniformly applied to the uncovered area of the substrate using one of the above methods.

[0172] In a preferred embodiment, the thickness of the thermosensitive material layer does not exceed 800 micromillimeters, preferably does not exceed 450 micromillimeters, and most preferably does not exceed 150 micrometers. The specified layer thickness of at least one thermosensitive material ensures that when heated above the threshold temperature corresponding to each material, the response speed of each material is less than 5 seconds. This is because this material layer thickness, combined with the thickness of the device base, can heat the thermosensitive material during short-term overheating during peak load and completely transform it into a melt with an "opaque-transparent" color change in less than 5 seconds, and also provide the necessary heat transfer during the air cooling of the operating device.

[0173] In a preferred embodiment, the surface area of the opaque substrate coated with one or more thermosensitive materials is at least 100 square millimeters.

[0174] In some embodiments of the present invention, first, a solvent dye is used to apply a black coating or inscription (specifically including the numerical value of the threshold temperature or other graphic, digital, or text information) to the uncovered area of the base, and then a layer of thermosensitive material is applied. In addition, in a preferred embodiment of the present invention, at least 70% of the bottom area is covered with a black coating. When at least a part of the base is painted black, at least one thermosensitive material has a white color in the initial state, and when heated above the corresponding threshold temperature, a "white-black" visual color change appears on at least a part of the device surface.

[0175] The number of thermosensitive materials is not limited by an upper limit and depends on the actual tasks performed by the device as stated in the usage statement (device type, steps required to determine the overheating temperature, surface area to be checked for heating, etc.). In special cases, the front surface of the base is coated with three to four different thermosensitive materials. In this case, the thermosensitive materials can be applied to adjacent and non-adjacent areas of the front surface of the base.

[0176] For example, for a device containing three different temperature-sensitive materials, the threshold temperatures can be 50°C, 55°C, 60°C, that is, the first temperature-sensitive material changes transparency when reaching 50°C, the second temperature-sensitive material changes transparency when reaching 55°C, and the third temperature-sensitive material changes transparency when reaching 60°C, with an accuracy of 5°C. In other embodiments, the threshold temperatures can be 50°C, 60°C, 70°C or 50°C, 70°C, 80°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.

[0177] For a device containing four different temperature-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 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.

[0178] In the final stage of preparation, the device is covered with a transparent protective layer. In some embodiments of the present invention, a gap can be provided between the protective layer and the substrate, or micropores can be provided in the transparent protective layer, so that the gas phase can escape outside the device after exceeding the recorded temperature. Preferably, the transparent protective layer is selected from transparent elastic polymers. In another embodiment of the present invention, the device blank is maintained at a pressure below atmospheric pressure, and then covered with a transparent protective layer to ensure the tightness of the device and maintain the pressure inside the gas phase void below atmospheric pressure. For this purpose, in the embodiments of the present invention, a transparent elastic polymer film is also used as the protective layer.

[0179] The operating principle of the device.

[0180] A device includes a flexible substrate 3 and one or more thermosensitive materials 1 applied thereon and a transparent protective layer 4. The device is mounted on a surface where temperature control must be ensured, and a fastening element provided by the device design is used to ensure a tight fit of the device. In a more preferred embodiment, the device is a sticker pasted to the surface using an adhesive layer, and the insulating layer is first removed from the adhesive layer. In the other two versions (clip and linen), the operating principle of the device is similar to that of the sticker.

[0181] Since the temperature overrun visual recording devices used in the power industry mainly adopt the form of stickers, the operating principle of the device will be discussed below taking the sticker as an example.

[0182] The device is in the form of a sticker and is coated with a thermosensitive material, and its working principle is as follows. The applied thermosensitive material 1 is opaque to at least part of the visible light in its initial state and before being heated to the threshold temperature, and is white in a preferred embodiment of the present invention. The thermosensitive material 1 remains opaque to at least part of the visible light until the entire surface of the device or the respective parts located below the thermosensitive material 1 are heated to the threshold temperature value, thus maintaining the original appearance of the device. When the surface is heated above the threshold temperature of the thermosensitive material 1, irreversible destruction of the microstructure of the thermosensitive material 1 occurs on the entire surface of the thermosensitive material 1 or mainly on the heated part 11 of the thermosensitive material 1, accompanied by the fusion of the solid organic matter 8 particles and the reduction of the proportion of the voids 9, resulting in an increase in transparency. This leads to an increase in the apparent density of the material. The thermosensitive material 1 with an improved microstructure is transparent and shows the color of the substrate 3 below the material or the color of the paint 7 applied to the substrate within the thermosensitive material area. When the controlled surface is subsequently cooled, the thermosensitive material 1 or its part 11 remains transparent, and the appearance of the device does not return to its original state. This ensures that the temperature exceeding the threshold temperature value can be visually recorded during overheating and after a long time.

[0183] If the device has multiple (n) areas of the thermosensitive material 1 with corresponding different threshold temperatures T1…n, then all the thermosensitive materials 1 remain opaque until the surface of the device located below the thermosensitive material 1 is heated to the threshold temperature T1, thus maintaining the original appearance of the device. When the threshold temperature T1 is reached, the solid organic matter particles of the first thermosensitive material 1 with the threshold temperature T1 lose their original shape and start to melt, and the microstructure starts to deteriorate irreversibly, and the proportion of voids decreases. As a result, the transparency of the corresponding thermosensitive material 1 increases and the color of the substrate 3 below it appears. At the same time, the other areas containing the thermosensitive material 1 (whose activation temperatures are T2…n>T1) retain their microstructures and thus their original appearances. Further increasing the temperature of the surface on which the device is placed to the temperatures T2…n will cause continuous irreversible destruction of the microstructure of the corresponding thermosensitive material 1 at the threshold temperatures T2…n. Moreover, if the maximum temperature of the device surface is lower than at least one of the thermosensitive material threshold temperatures Tn, the corresponding areas of the thermosensitive material Tn will retain their microstructures and original opacities. After the device surface is subsequently cooled, the areas of the thermosensitive material 1 with a modified microstructure remain transparent, and the appearance of the device does not return to its original state. If the device surface is repeatedly overheated to reach the threshold temperature Tn of a previously unused thermosensitive material area and reaches a given accuracy, the microstructure of the corresponding thermosensitive material 1 will be irreversibly destroyed, and an "opaque - transparent" transition will occur, and the color of the substrate 3 below it will appear.

[0184] When locally heating a controlled surface, a transparent region 11 is formed only in the area where the thermosensitive material is heated above a threshold temperature, while an opaque region of a given material is maintained in the remaining areas that are not heated.

[0185] The value of the threshold temperature 2 can be applied to the front surface of the base 3; in special cases, the value of the threshold temperature can be applied in the area without the thermosensitive material 1 but adjacent to the thermosensitive material 1, or applied to the base 3 under the thermosensitive material 1; in the latter case, when the temperature exceeds the corresponding threshold temperature, after the microstructure of the corresponding thermosensitive material 1 undergoes an irreversible change, the color of the base 3 and the value of the threshold temperature 2 appear. In a specific embodiment, the base can be black, and the thermosensitive material can be white in its original opaque state. In this case, when the temperature exceeds the corresponding threshold temperature, a change in the appearance of the device can be observed, with a maximum contrast of "white - black", which further ensures the visibility of the triggering device and facilitates its visual recognition. A device is used to achieve a similar purpose, where the base has a color other than black, and a black coating is applied in the area under the thermosensitive material 1 (which is white in its original state). In this case, when the device is triggered, a "white - black" color change is also observed.

[0186] For a device sealed with an elastic transparent protective layer 4 under atmospheric pressure, at the moment of operation, due to the destruction of the microstructure of the thermosensitive material 1 and the stratification of the gaseous and non - gaseous environments on the surface of the protective layer 4, bubbles are formed, and the bubbles will decrease as the device cools. When using a device with a sealed protective layer 4, if the pressure in the voids 9 of the thermosensitive material 1 is lower than atmospheric pressure, no bubbles will form on the surface of the protective layer 4 when the threshold temperature is exceeded, because the gas pressure in the voids 9 generated during the application of the protective layer 4 at the stage of obtaining the device blank is lower than atmospheric pressure in the initial state, compensating for the thermal expansion of the gas released during the destruction of the microstructure of the thermosensitive material 1. In other embodiments of this device, in order to prevent the formation of bubbles when the threshold temperature is exceeded, a gap 5a can be provided between the transparent protective layer and the base, or micropores 5b can be provided in the protective layer, on the one hand, to provide the possibility of releasing the gas released during operation.

[0187] An embodiment of this device has a similar operating principle, where the composition of the thermosensitive material 1 includes solid organic particles 8, voids 9, and an adhesive 10. When the temperature exceeds the corresponding threshold temperature, the particles 8 "glazed" by the adhesive 10 melt, releasing a gas phase and separating the gas and non - gaseous environments. As a result, the microstructure of the thermosensitive material 1 also undergoes an irreversible destruction, and at the same time, the proportion of the voids 9 decreases. Therefore, the transparency of the material increases.

[0188] Therefore, the operating principle of all versions of the device is based on the irreversible destruction of the microstructure of the thermosensitive material 1, accompanied by the fusion of the solid organic matter 8 particles and the reduction of the proportion of voids 9. As a result, the transparency of the material increases and the appearance of the device changes. Moreover, when the device cools down, its appearance does not return to the original state.

[0189] Therefore, when visually inspecting the device, the fact that the temperature of the entire surface or a local area thereof exceeds at least one threshold temperature value can be reliably and accurately recorded.

[0190] The preferred embodiments of the claimed device are given below. These embodiments are for illustrative purposes only and do not limit the scope of the claimed legal protection in any way.

[0191] Example

[0192] 1. Obtain a suspension of solid organic matter in a liquid phase

[0193] Grind the solid organic matter until the particle size reaches 2 - 3 microns, add it to the liquid phase and stir, ensuring that the mixture is regularly dispersed in the presence of air until a constant density of the mixture is obtained. The resulting suspension of each solid organic matter in the liquid phase is used immediately after preparation for application.

[0194] 2. Obtain a suspension of solid organic matter in a liquid phase using an adhesive

[0195] Grind the solid organic matter to a particle size of 2 - 3 microns, add it to the liquid phase adhesive solution and stir, ensuring that the mixture is regularly dispersed in the presence of air until a constant density of the mixture is obtained. The resulting suspension of each solid organic matter in the liquid phase is used immediately after preparation for application.

[0196] 3. A method of applying a suspension of solid organic matter in a liquid phase to a substrate using a sub - atmospheric pressure after applying each layer

[0197] The area on the front of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. Use a roller to apply a layer of the suspension of solid organic matter in the liquid phase obtained according to Example 1 or 2 to the uncovered area of the base, maintain the resulting layer under a pressure of 10 - 300 mmHg for at least 1 minute. As a result, part or all of the liquid phase is removed, and then the application and drying processes are repeated several times until the specified thickness of the thermosensitive material layer and the required covering power are achieved. After that, the protective film is removed, and the resulting device is covered with a transparent polymer protective layer at atmospheric pressure.

[0198] 4. A method of applying a suspension of solid organic matter in a liquid phase to a substrate using a sub - atmospheric pressure after all layers have been applied

[0199] The area on the front side of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. Using a roller, several layers of the suspension of solid organic substances in the liquid phase obtained according to Example 1 or 2 are continuously applied to the uncovered area of the substrate until the specified thickness of the thermosensitive material layer and the required covering power are obtained, and the layers are not dried between the applications. The resulting blank is held at a pressure of 1 - 150 mmHg for at least 10 minutes, causing partial or complete removal of the liquid phase, then the protective film is removed and the resulting device is covered with a transparent polymer protective layer under atmospheric pressure.

[0200] 5. A method for applying a suspension of solid organic substances in a liquid phase to a substrate using subatmospheric pressure during the stage of applying a protective layer

[0201] The area on the front side of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. Several layers of the suspension of solid organic substances in the liquid phase obtained according to Example 1 or 2 are successively applied to the uncovered area of the substrate using a roller until the specified thickness of the thermosensitive material layer and the required covering power are reached. Before applying the next layer, each layer is dried in air for at least 10 minutes, thereby partially or completely removing the liquid phase; after applying the last layer, the resulting workpiece is held at atmospheric pressure for at least 1 hour, which also causes removal of the liquid phase in the top layer and the remaining liquid phase in the previous layers. Then the protective film is removed, and the resulting device is covered with a transparent polymer protective layer at a pressure of 200 - 650 mmHg, as a result, the remaining liquid phase is completely removed, and when covered with the protective layer, a subatmospheric pressure is additionally formed in the resulting voids.

[0202] 6. A method for applying a suspension of solid organic substances in a liquid phase to a substrate using subatmospheric pressure after applying all layers and during the stage of covering with a protective layer

[0203] The area on the front side of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. Using a roller, several layers of the suspension of solid organic substances in the liquid phase obtained according to Example 1 or 2 are continuously applied to the uncovered area of the substrate until the specified thickness of the thermosensitive material layer and the required covering power are obtained, and the layers are not dried between the applications. The resulting workpiece is held at a pressure of 1 - 300 mmHg for at least 10 minutes, causing partial or complete removal of the liquid phase. Then the protective film is removed, and the resulting device is covered with a transparent polymer protective layer at a pressure of 200 - 650 mmHg, as a result, the liquid phase is completely removed, and when covered with the protective layer, a subatmospheric pressure is additionally formed in the resulting voids.

[0204] 7. A method for applying a suspension of solid organic substances in a liquid phase to a substrate using subatmospheric pressure in all three stages

[0205] The area on the front side of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. A suspension layer of solid organic substances in the liquid phase obtained according to Example 1 or 2 is applied to the uncovered area of the substrate using a roller, and the resulting layer is held under a pressure of 10 - 300 mmHg for at least 1 minute. As a result, the liquid phase is partially or completely removed. Then, the application and drying processes are repeated several times until the specified thickness of the thermosensitive material layer and the required covering power are obtained. Then, the resulting blank is held under a pressure of 30 - 200 mmHg for at least 10 minutes, and as a result, the remaining liquid phase is completely removed. After that, the protective film is removed, and a transparent polymer protective layer is applied to the resulting device under a pressure of 200 - 650 mmHg. As a result, the liquid phase is completely removed, and when the protective layer is applied, a pressure below atmospheric pressure is also formed in the resulting voids.

[0206] 8. Method for applying a suspension of solid organic substances in a liquid phase to a substrate using pad printing

[0207] The area on the front side of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. A swab larger than the area of application of the thermosensitive material is immersed in the suspension for 1 second, and then the excess suspension is allowed to flow out. A layer of a suspension of solid organic substances in the liquid phase obtained according to Example 1 or 2 is applied to the uncovered area of the substrate using a cotton plug, and the resulting layer is held at atmospheric pressure for at least 10 minutes, thereby partially or completely removing the liquid phase. Then, the application and drying processes are repeated several times until the specified thickness of the thermosensitive material layer and the required covering power are obtained. Then, the resulting blank is dried at atmospheric pressure for at least 1 hour to completely remove the remaining liquid phase. After that, the protective film is removed, and the resulting device is covered with a transparent polymer protective layer.

[0208] 9. Method for applying a suspension of solid organic substances in a liquid phase to a substrate using flexographic printing

[0209] The area on the front side of the base that should not come into contact with the thermosensitive material is sealed with a polyethylene film. The anilox roll is treated with the suspension, and then the suspension is transferred from the anilox roll to the relief printing plate, and the size of the raised part of the relief printing plate exceeds the size of the area where the thermosensitive material is applied. A suspension layer of solid organic substances in the liquid phase obtained according to Example 1 or 2 is applied to the uncovered area of the substrate using the relief printing plate, and the resulting layer is held at atmospheric pressure for at least 10 minutes. As a result, partial or complete removal of the liquid phase occurs. Then, the application and drying processes are repeated several times until the specified thickness of the thermosensitive material layer and the required covering power are obtained. Then, the resulting blank is dried at atmospheric pressure for at least 1 hour to completely remove the remaining liquid phase. After that, the protective film is removed, and the resulting device is covered with a transparent polymer protective layer.

[0210] 10. Method for applying a suspension of solid organic substances in a liquid phase to a substrate by screen printing

[0211] Fix a template with a fine grid on the front surface of the base, the size of which corresponds to the size of the area where the thermosensitive material is to be applied. Use a rubber squeegee to evenly distribute the suspension of solid organic substances in the liquid phase obtained according to Example 1 or 2 on the template. Keep the resulting layer at atmospheric pressure for at least 10 minutes, causing partial or complete removal of the liquid phase, and then repeat the application and drying process several times until the desired number of thermosensitive material layers is obtained. Then dry the resulting blank at atmospheric pressure for at least 1 hour to completely remove the residual liquid phase, after which remove the protective film and cover the resulting device with a transparent polymer protective layer.

[0212] 11. Determination of the covering power of the material obtained by the method claimed in this group of inventions

[0213] The solid organic substances used are substances such as alkanes (tetracosane), fatty acids (arachidic acid), and fatty acid salts (lanthanum hexanoate) (100 g), the liquid phase is 100 g of isopropanol, and the binder is 100 g of a 3% phenolic resin isopropanol solution. The suspension of each solid organic substance in the liquid phase obtained is used for application immediately after preparation.

[0214] To determine the covering power, use a pre-weighed glass plate as the base. According to the methods described in Examples 3, 4, 8 - 10, apply the suspensions of tetracosane and arachidic acid in isopropanol obtained according to Example 1 to the glass plate respectively, except for the step of applying the protective layer. According to the methods described in Examples 3, 4, 8 - 10, apply the suspension of lanthanum hexanoate added with phenol formaldehyde resin in isopropanol obtained according to Example 2 to the glass plate, except for the stage of applying the protective layer. The number of layers of the suspension of the corresponding solid organic substances in the liquid phase in the samples obtained according to Examples 3 and 4 are 1, 3, 5, 7, 10, 15, 20 layers respectively, and the number of layers of the suspension of the corresponding solid organic substances in the liquid phase in the samples obtained according to Examples 8 - 10 are 3, 5, 7, 10, 15, 20 layers respectively. For each sample, determine the average thickness of the applied thermosensitive material layer with an accuracy of 1 micromillimeter and its mass with an accuracy of 0.001 g, then place the resulting plate with the thermosensitive material on a contrast plate and observe under diffused daylight whether white and black areas can be seen. The test results are shown in Tables 1 - 2.

[0215] Table 1 - 2. Covering power test of the material obtained by the method claimed in this group of inventions

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222] During the testing process, it has been determined that the hiding power of the thermosensitive material of any selected category of solid organic substances applied by any given method is achieved by having the number of thermosensitive material layers equal to or greater than 3 and the thickness of the thermosensitive material equal to or greater than 30 micromillimeters.

[0223] 12. Determination of the hiding power of materials by methods known in the prior art

[0224] 100 g of solid organic substances of alkanes (tetracosane), fatty acids (arachidic acid), and fatty acid salts (lanthanum hexanoate) were placed in a ball mill and ground for 30 hours until the particle size reached 2 - 3 micromillimeters. 100 g of isopropanol was added, and then stirred for 10 hours. Different from Examples 1 - 2, the mixture was not dispersed. The resulting suspension of each thermosensitive material was used for application immediately after receipt.

[0225] To determine the hiding power, pre - weighed glass plates were used as the base. The areas on the front of each glass plate that should not come into contact with the thermosensitive material were sealed with polyethylene film. Using a roller, the following were applied to the uncovered areas of each glass plate: the first plate was applied with one layer of suspension, the second plate with five layers of suspension, the third plate with ten layers of suspension, the fourth plate with fifteen layers of suspension, and the fifth plate with twenty layers of suspension. The layers were applied in sequence without intermediate drying between each application; after applying the last layer of the thermosensitive material suspension, the plates were air - dried at room temperature to a constant weight. The average thickness of the applied thermosensitive material layer was measured with an accuracy of 1 micromillimeter, and its mass was measured with an accuracy of 0.001 g. Then, the plates with the thermosensitive material were placed on a contrast plate and observed under diffused daylight to see if white and black areas were visible. The test results are shown in Table 3.

[0226] Table 3. Hiding power test of materials obtained by methods known in the prior art

[0227]

[0228]

[0229] During the testing process, it was determined that the hiding power of the thermosensitive material of any selected category of solid organic substances can be achieved when the number of thermosensitive material layers is equal to 20 and the thickness of the thermosensitive material is greater than 2100 micromillimeters.

[0230] Examples 13 - 30. Manufacture of special equipment.

[0231] 13. Prepare a suspension of 100 g of tetracosane with a phase transition temperature of 50 °C and 100 g of isopropyl alcohol according to Example 1. Apply the suspension to a black OraJet 3951 PVC film with an adhesive layer. This film has fire resistance, an electrical strength of at least 5 kV / mm, and sufficient flexibility and strength to mount and firmly adhere the device to a surface with a complex geometry. The thickness (excluding the adhesive layer) is 0.5 mm, and a pressure of 10 mm Hg is used according to the method described in Example 3. The thickness of the thermosensitive material is 82 microns, and the total number of layers is 5. The front side of the protective layer has micropores. The thermosensitive material is white in its original state.

[0232] The device is mounted on a heating element at room temperature and then heated at a controlled rate of 5 °C / second to a temperature of 50 °C with a specified accuracy. Then, heating is stopped, and the operation of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the underlying substrate. The time for the phase change and transparency change of the thermosensitive material is 2 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0233] 14. Prepare a suspension of 100 g of yttrium hexanoate with a phase transition temperature of 55 °C, 100 g of methanol, and 100 g of a 3% phenolic resin methanol solution according to Example 2. Apply the suspension to a black OraJet 3106SG PVC film with an adhesive layer. This film has fire resistance, an electrical strength of at least 5 kV / mm, and sufficient flexibility and strength to mount and firmly adhere the device to a surface with a complex geometry. The thickness (excluding the adhesive layer) is 0.8 mm, and a pressure of 1 mm Hg is used according to the method described in Example 4. The thickness of the thermosensitive material is 310 microns, and the total number of layers is 15. There are micropores between the protective layer and the substrate. The thermosensitive material is white in its original state.

[0234] The device is mounted on a heating element at room temperature and then heated at a controlled rate of 5 °C / second to a temperature of 55 °C with a specified accuracy. Then, heating is stopped, and the operation of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the underlying substrate. The time for the phase change and transparency change of the thermosensitive material is 1 second. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0235] 15. Prepare a suspension of 100 g of palmitic anhydride with a phase transition temperature of 60 °C, 100 g of 1-propanol, and a 1-propanol solution of 100 g of 1% butyl methacrylate resin according to Example 2. Apply this suspension to a black polyurethane film 3981RA with an adhesive layer. The thickness without the adhesive layer is 0.2 mm, and a pressure of 200 mmHg is used according to the method described in Example 5. The thickness of the thermosensitive material is 428 micrometers, and the total number of layers is 20 layers. The thermosensitive material is white in its original state.

[0236] The device is mounted on a heating element at room temperature and then heated controllably at a rate of 5 °C per second to a temperature of 60 °C and reaches the specified accuracy. Then, heating is stopped, and the fact that the device is operating is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the underlying substrate. The time for the phase change and transparency change of the thermosensitive material is 2 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0237] 16. Prepare a suspension of 100 g of arachidic acid with a phase transition temperature of 70 °C, 100 g of isobutanol, and 100 g of a 10% melamine formaldehyde resin solution in isobutanol according to Example 2. Apply this suspension to a yellow polyester film 3M: 50 / RC20 / HD70WH with an adhesive layer. The thickness without the adhesive layer is 0.4 mm, and a pressure of 1 mmHg is applied after all layers are applied, and -200 mmHg before applying the protective layer. Black paint is applied to the uncovered area of the base before applying the suspension with a solvent dye. The thickness of the thermosensitive material is 195 micrometers, and the total number of layers is 10 layers. The thermosensitive material is white in its original state and completely covers the black paint applied on the base.

[0238] The device is mounted on a heating element at room temperature and then heated controllably at a rate of 5 °C per second to a temperature of 70 °C and reaches the specified accuracy. Then, heating is stopped, and the fact that the device is operating is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the underlying substrate. The time for the phase change and transparency change of the thermosensitive material is 3 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0239] 17. Prepare a suspension of oleamide (100 g) with a phase transition temperature of 75 °C, 100 g of ethylene glycol monomethyl ether, and 100 g of a 15% solution of polyvinyl butyral in ethylene glycol monomethyl ether according to Example 2. Apply this suspension onto a black polyester film 3M: WHITEV TC with an adhesive layer. The thickness without the adhesive layer is 0.4 mm. According to the method described in Example 7, apply a pressure of 1 mm Hg after applying each layer, and a pressure of 30 mm Hg after applying all layers. The pressure is 200 mm Hg before applying the protective layer. The thickness of the thermosensitive material is 119 microns, and the total number of layers is 7. The thermosensitive material is white in its original state.

[0240] The device is mounted on a heating element at room temperature and then heated at a controlled rate of 5 °C / second to a temperature of 75 °C with a specified accuracy. Then, heating is stopped, and the operation of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the underlying substrate. The time for the phase transition and transparency change of the thermosensitive material is 3 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0241] 18. Prepare 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 according to Example 2. Apply the suspension onto a black polyester film 3M: 7874E with an adhesive layer according to the method described in Example 8. The thickness without the adhesive layer is 0.4 mm. The thickness of the thermosensitive material is 52 microns, and the total number of layers is 5. The thermosensitive material is white in its original state.

[0242] The device is mounted on a heating element at room temperature and then heated at a controlled rate of 5 °C / second to a temperature of 70 °C with a specified accuracy. Then, heating is stopped, and the operation of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the underlying substrate. The time for the phase transition and transparency change of the thermosensitive material is 4 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0243] 19. Prepare a suspension of 100 g of dioctadecylamine with a phase transition temperature of 70 °C, 100 g of acetonitrile, and 100 g of an acetonitrile solution of 30% polybutyl acrylate according to Example 2. Apply the suspension to a yellow ORALITE 5500 polymethyl methacrylate film with an adhesive layer according to the method described in Example 9. The thickness without the adhesive layer is 0.4 mm. Before applying the suspension, apply a black coating marked with the threshold temperature value to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 39 μm and the total number of layers is 3. The thermosensitive material is white in its original state.

[0244] The device is mounted on a heating element at room temperature and then heated at a controlled rate of 5 °C / second to a temperature of 70 °C with a specified accuracy. Then, heating is stopped, and the operation of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, revealing the color of the substrate below and the value of the threshold temperature. The time for the phase change and transparency change of the thermosensitive material is 4 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0245] 20. A suspension of 100 g of a solid organic substance, 100 g of acetic acid, and 100 g of a 3% binder acetic acid solution was prepared according to Example 2. The solid organic substances 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. Polyethylene, polyvinyl chloride, and polycarbonate were used as binders. The suspension was applied to a yellow Optibelt elastomer film with a binder layer according to the method described in Example 10. The thickness without the binder layer was 0.4 mm. Before applying the suspension, a black coating was applied to the uncovered area of the substrate using a solvent dye. Each suspension of the solid organic substance in the liquid phase was applied to a separate area of the substrate. The thicknesses of the thermosensitive materials were 328, 406, and 394 micrometers respectively, and the number of layers of each material was 15. The thermosensitive materials were white in their original state. The device was mounted on a heating element at room temperature and then heated controllably at a rate of 5 °C / second to a temperature of 80 °C and reached the specified accuracy, then heating was stopped, and the operation of the corresponding area of the device was recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material underwent an irreversible change and became transparent, revealing the color of the underlying substrate. The time for the first thermosensitive material to undergo a phase change and a change in transparency was 2 seconds. Subsequently, after cooling the device to room temperature, it was visually recorded that the device retained its appearance and the transparency of the thermosensitive material did not return to its original state. The cycles of heating to 90 °C and 100 °C were repeated and then cooled to room temperature. After each cycle, the change in transparency of the corresponding area of the thermosensitive material was recorded. The time for the second thermosensitive material to undergo a phase change and a change in transparency was 2 seconds, and the time for the third thermosensitive material to undergo a phase change and a change in transparency was 1 second. After finally cooling the device to room temperature, the transparency retention of all thermosensitive material areas was visually recorded.

[0246] 21. A suspension of 100 g of a solid organic substance, 100 g of 1,1,1-trifluoroethanol, and 100 g of a 3% binder 1,1,1-trifluoroethanol solution was prepared according to Example 2. As the solid organic substances, lanthanum nonadecanoate with a phase transition temperature of 110 °C, lanthanum hexanoate with a phase transition temperature of 120 °C, zinc nonadecanoate with a phase transition temperature of 130 °C, and zinc palmitate with a phase transition temperature of 140 °C were used. Polyester, polymethacrylate, gelatin, and ethyl cellulose were used as binders. The suspension was applied to a red Aurora self-adhesive fabric with a binder layer according to the method described in Example 10. The thickness without the binder layer was 0.4 mm. Before applying the suspension, a black coating was applied to the uncovered area of the substrate using a solvent dye, and the value of the threshold temperature was applied to the area of the substrate where there was no thermosensitive material on the front side. Each suspension of the solid organic substance in the liquid phase was applied to a separate area of the substrate. The thicknesses of the thermosensitive materials were 53, 39, and 43 micrometers respectively, and the number of layers of each material was 3. The thermosensitive materials were white in their original state.

[0247] The device is mounted on a heating element at room temperature and then heated controllably at a rate of 5 °C per second to a temperature of 110 °C and reaches the specified accuracy. Then the heating is stopped, and the operation of the corresponding area of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent, showing the color of the substrate below it. The time for the first thermosensitive material to undergo a phase change and a change in transparency is 2 seconds. Subsequently, after cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state. The cycles of heating to 120 °C, 130 °C, and 140 °C are repeated and then cooled to room temperature. After each cycle, the change in transparency of the corresponding area of the thermosensitive material is recorded. The time for the second thermosensitive material to undergo a phase change and a change in transparency is 1 second, the time for the third thermosensitive material to undergo a phase change and a change in transparency is 2 seconds, and the time for the fourth thermosensitive material to undergo a phase change and a change in transparency is 1 second. After finally cooling the device to room temperature, the preservation of the transparency of all thermosensitive material areas is visually recorded.

[0248] 22. Prepare a solid organic suspension (100 g), 100 g of 1,1,1,3,3,3-hexafluoroisopropanol, and a 1,1,1,3,3,3-hexafluoroisopropanol solution of 100 g of 3% binder according to Example 2. The solid organic substances used are as follows: n-docosylamine with a phase transition temperature of 65 °C, tetracosane with a phase transition temperature of 80 °C, and didodecylphosphinic acid with a phase transition temperature of 90 °C. Phenoxy resin, polyethersulfone, and polypropylene are used as binders. Apply the suspension to a red Silicraft silicated cardboard with an adhesive layer according to the method described in Example 7. The thickness excluding the adhesive layer is 0.4 mm, the pressure after applying each layer is 150 mmHg, the pressure after applying all layers is 100 mmHg, and -450 mmHg before applying the protective layer, and a black coating is applied to the uncovered area of the base using a solvent dye before applying the suspension, and the numerical value of the threshold temperature is applied to the front surface of the base in the area without the thermosensitive material. Each portion of the solid organic suspension in the liquid phase is applied to a separate area of the substrate. The thicknesses of the thermosensitive materials are 387, 472, and 434 micrometers respectively, and the number of layers of each material is 15 layers. The thermosensitive material is white in its original state.

[0249] The device is mounted on the heating element at room temperature and then heated controllably at a rate of 5 °C per second to 65 °C and reaches the specified accuracy. The operation of the corresponding area of the device is recorded by visually recording the increase in the transparency of the thermosensitive material. Next, immediately heat the heating element controllably at a rate of 5 °C per second to a temperature of 80 °C with a given accuracy, and record the operating facts of another corresponding area of the device in a similar manner. Then, immediately heat the heating element controllably at a rate of 5 °C per second to a temperature of 90 °C with a given accuracy, and record the operating facts of the third corresponding area of the device. After cooling the device to room temperature, visually record the transparency of all areas of the thermosensitive material.

[0250] 23. Prepare a suspension of zinc hexanoate (100 g) with a phase transition temperature of 150 °C and 100 g of dimethylformamide according to Example 1. Using the method described in Example 4, apply the suspension to a black PVC tube with a diameter of 3 mm, refractory, an electrical strength of at least 5 kV / mm, flexibility and strength, and a thickness of 0.5 mm under a pressure of 300 mmHg. The thickness of the thermosensitive material is 522 microns and the total number of layers is 20 layers. The thermosensitive material is white in its original state.

[0251] The device is mounted on the heating element at room temperature and then heated controllably at a rate of 5 °C per second to a temperature of 150 °C and reaches the specified accuracy. Then stop heating, and record the fact of the device operation by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent as a result, revealing the color of the underlying substrate. The time for the phase change and transparency change of the thermosensitive material is 2 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0252] 24. Prepare a suspension of lithium stearate (100 g) with a phase transition temperature of 210 °C and a mixture of 100 g of ethanol and water (50 / 50 vol%) according to Example 1. Apply the suspension to a white PVC cable clamp with a diameter of 5 mm, refractory, an electrical strength of at least 5 kV / mm, flexibility and strength, and a thickness of 1 mm using the method described in Example 5 under a pressure of 650 mmHg. Before applying the suspension, apply black paint to the uncovered area of the base using a solvent dye. The thickness of the thermosensitive material is 84 microns and the total number of layers is 5 layers. The thermosensitive material is white in its original state.

[0253] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to a temperature of 210 °C with a specified accuracy. Then, the heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and as a result becomes transparent, revealing the color of the underlying substrate. The time for the phase transition and transparency change of the thermosensitive material is 2 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0254] 25. Prepare a suspension (100 g) of stearic acid 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 according to Example 2. Apply the suspension to a yellow ORALITE 5500 methyl methacrylate film with an adhesive layer, the thickness of the removed adhesive layer is 0.4 mm. According to the method described in Example 6, after applying all the layers, a pressure of 300 mm Hg is used, and after applying the protective layer, -650 mm Hg. Before applying the suspension, a black coating including the threshold temperature value is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 680 microns, and the total number of layers is 26. The thermosensitive material is white in its original state.

[0255] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to a temperature of 70 °C with a specified accuracy. Then, the heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and as a result becomes transparent, showing the color of the underlying substrate and the value of the threshold temperature. The time for the phase transition and transparency change of the thermosensitive material is 3 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0256] 26. Prepare a suspension of behenic acid (100 g) with a phase transition temperature of 80 °C, 100 g of acetone, and 100 g of a 30% polyvinylidene fluoride acetone solution according to Example 2. Apply the suspension to a yellow ORALITE 5500 methyl methacrylate film with an adhesive layer, the thickness of the film without the adhesive layer is 0.4 mm. According to the method described in Example 7, the pressure used after applying each layer is 300 mm Hg, and the pressure used after applying all the layers is 200 mm Hg. And -650 mm Hg before applying the protective layer, and before applying the suspension, a black coating containing the threshold temperature value is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 282 microns, and the total number of layers is 10. The thermosensitive material is white in its original state.

[0257] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to 80 °C under control until the given accuracy is achieved. Heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and as a result becomes transparent, showing the color of the substrate beneath it and the value of the threshold temperature. The time for the phase change and transparency change of the thermosensitive material is 2 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0258] 27. A suspension of 100 g of erucamide with a phase transition temperature of 75 °C and 100 g of hexane is prepared according to Example 1. According to the method described in Example 4, the suspension is applied to a yellow ORALITE 5500 methyl methacrylate film with an adhesive layer at a pressure of 150 mmHg. The film without the adhesive layer has a thickness of 0.4 mm, and before applying the suspension, a black coating containing the value of the threshold temperature is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 429 microns and the total number of layers is 17. The thermosensitive material is white in its original state.

[0259] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to a temperature of 75 °C under control until the specified accuracy is achieved. Then heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and as a result becomes transparent, showing the color of the substrate beneath it and the value of the threshold temperature. The time for the phase change and transparency change of the thermosensitive material is 4 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0260] 28. A suspension of 100 g of stearyl alcohol with a phase transition temperature of 60 °C and 100 g of heptane is prepared according to Example 1. According to the method described in Example 3, the suspension is applied to a yellow ORALITE 5500 methyl methacrylate film with an adhesive layer at a pressure of 300 mmHg. The film without the adhesive layer has a thickness of 0.4 mm, and before applying the suspension, a black coating containing the value of the threshold temperature is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 61 mm and the total number of layers is 4. The thermosensitive material is white in its original state.

[0261] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to a temperature of 60 °C under control and with the specified accuracy. Then, heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, an irreversible change occurs in the microstructure of the thermosensitive material, and as a result, it becomes transparent, showing the color of the substrate below it and the value of the threshold temperature. The time for the phase transition and transparency change of the thermosensitive material is 4 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0262] 29. A suspension of 100 g of cetyl alcohol with a phase transition temperature of 50 °C, 100 g of toluene, and 100 g of a 30% solution of nitrocellulose in toluene is prepared according to Example 2. According to the method described in Example 5, the suspension is applied to a yellow ORALITE 5500 methyl methacrylate film with an adhesive layer at a pressure of 450 mmHg. The thickness of the film without the adhesive layer is 0.4 mm, and before applying the suspension, a black coating containing the value of the threshold temperature is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 92 microns, and the total number of layers is 8. The thermosensitive material is white in its original state.

[0263] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to a temperature of 50 °C under control and with the specified accuracy. Then, heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, an irreversible change occurs in the microstructure of the thermosensitive material, and as a result, it becomes transparent, showing the color of the substrate below it and the value of the threshold temperature. The time for the phase transition and transparency change of the thermosensitive material is 1 second. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0264] 30. A suspension of 100 g of dispersed polyethylene 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 is prepared according to Example 2. According to the method described in Example 3, the suspension is applied to a yellow ORALITE 5500 methyl methacrylate film with an adhesive layer at a pressure of 150 mmHg. The thickness of the film without the adhesive layer is 0.4 mm, and before applying the suspension, a black coating containing the value of the threshold temperature is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 252 microns, and the total number of layers is 13. The thermosensitive material is white in its original state.

[0265] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to 110 °C under control to achieve a given accuracy. Heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, an irreversible change occurs in the microstructure of the thermosensitive material, as a result of which it becomes transparent, showing the color of the underlying substrate and the value of the threshold temperature. The time for the phase transition and the change in transparency of the thermosensitive material is 2 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0266] 31. A suspension of docosane-1-ol (100 g) with a phase transition temperature of 90 °C and a mixture of 100 g of ethanol and water (50 / 50 vol%) is prepared according to Example 1. The suspension is applied to a yellow OraJet 3951 PVC film with an adhesive layer, the thickness without the adhesive layer being 0.3 mm. According to the method described in Example 6, after applying all the layers, a pressure of 150 mm Hg is applied, and the temperature is reduced to 450 mm Hg before applying the protective layer. Before applying the suspension, a black coating marked with the value of the threshold temperature is applied to the uncovered area of the substrate using a solvent dye. The thickness of the thermosensitive material is 452 microns, and the total number of layers is 18. The thermosensitive material is white in its original state.

[0267] The device is mounted on a heating element at room temperature and then heated at a rate of 5 °C per second to a temperature of 90 °C and reaches the specified accuracy. Then heating is stopped, and the fact of the device operation is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, an irreversible change occurs in the microstructure of the thermosensitive material, as a result of which it becomes transparent, revealing the color of the underlying substrate. The time for the phase transition and the change in transparency of the thermosensitive material is 2 seconds. After subsequently cooling the device to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0268] 32. A suspension of a solid organic substance (100 g), 100 g of isopropyl alcohol, and 100 g of a 3% binder solution in isopropyl alcohol was prepared according to Example 2. The solid organic substances used were: tridecanedioic anhydride (phase transition temperature of 50 °C), docosanenitrile (phase transition temperature of 55 °C), and palmitic acid (phase transition temperature of 60 °C). Polyethylene, polyvinyl chloride, and polycarbonate were used as binders. The suspension was applied to a yellow Optibelt elastomer film with a binder layer according to the method described in Example 10. The thickness of the film without the binder layer was 0.4 mm. Before applying the suspension, a black coating was applied to the uncovered area of the substrate using a solvent dye. Each suspension of the solid organic substance in the liquid phase was applied to a separate area of the substrate. The thicknesses of the thermosensitive materials were 328, 406, and 394 micrometers respectively, and the number of layers of each material was 15. The thermosensitive materials were white in their original state. The device was mounted on a heating element at room temperature and then heated at a rate of 5 °C / second to a temperature of 50 °C in a controlled manner and reached the specified accuracy. Heating was stopped and the operation of the corresponding area of the device was recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, an irreversible change occurred in the microstructure of the thermosensitive material, and as a result, it became transparent, showing the color of the substrate below it. The time for the first thermosensitive material to undergo a phase change and a change in transparency was 1 second. Subsequently, after cooling the device to room temperature, it was visually recorded that the device retained its appearance and the transparency of the thermosensitive material did not return to its original state. The heating cycle was repeated up to 55 °C and 60 °C, and then cooled to room temperature. After each cycle, the change in transparency of the corresponding area of the thermosensitive material was recorded. The time for the second thermosensitive material to undergo a phase change and a change in transparency was 3 seconds, and the time for the third thermosensitive material to undergo a phase change and a change in transparency was 1 second. After finally cooling the device to room temperature, the preservation of the transparency of all areas of the thermosensitive material was visually recorded.

[0269] 33. The device was exposed to a temperature close to the threshold for a long time

[0270] The device according to Example 22 was mounted on a heating element at room temperature and then heated in a controlled manner to a temperature of 140 °C at a rate of 5 °C / second and maintained at this temperature for 10 hours. Then they stopped heating and recorded the preservation of the original appearance of the device: the transparency of the thermosensitive material did not change. Subsequently, when the device was cooled to room temperature, the transparency of the thermosensitive material did not change either, and the appearance of the device remained in its original state.

[0271] Then, the device is heated at a rate of 5 °C / second in a controlled manner to 150 °C with a given precision, and the operation fact of the device is recorded by visually recording the increase in the transparency of the thermosensitive material: after reaching the set temperature, the microstructure of the thermosensitive material undergoes an irreversible change and becomes transparent as a result, showing the color of the underlying substrate. Subsequently, after the device is cooled to room temperature, it is visually recorded that the device retains its appearance and the transparency of the thermosensitive material does not return to its original state.

[0272] Next, the activated device is placed in a cold storage room with a temperature set at -20 °C, maintained at this temperature for 10 hours, and the retention of the transparency of the thermosensitive material after this time and after the device returns to room temperature is recorded. It can be seen from this that the device can maintain its original state at a temperature close to the threshold before operation, and after operation, it will not return to its original state even when exposed to low temperature for a long time.

Claims

1. An apparatus for visually recording a temperature rise above at least one threshold, having a layered structure, comprising: - a substrate opaque to at least part of visible light, on the front surface of which an inscription indicating at least one numerical threshold temperature value is engraved; - at least one thermosensitive material opaque to at least part of visible light, applied to various parts of the substrate, the microstructure of which comprises particles of solid organic substances and voids filled with a gas phase; - a transparent protective layer covering part or all of the front surface of the device; wherein the device is designed to irreversibly change its appearance due to the destruction of the microstructure of the corresponding thermosensitive material when at least one threshold temperature indicated thereon is reached, accompanied by the fusion of solid organic substance particles, a decrease in the proportion of voids, an increase in transparency, and the appearance of the color of the substrate.

2. The apparatus according to claim 1, characterized in that the gas pressure in the voids of the thermosensitive material is lower than atmospheric pressure.

3. The apparatus according to claim 1, characterized in that a gap is provided between the transparent protective layer and the substrate, or micropores are provided on the protective layer, so that the gas contained in the voids escapes outside the device after the recording temperature is exceeded.

4. The apparatus according to claim 1, characterized in that in the initial state, in the microstructure of at least one thermosensitive material, the particles of solid organic substances are mainly oriented parallel to the surface of the substrate and the plane of the protective coating.

5. The apparatus according to claim 1, characterized in that the pore proportion of at least one thermosensitive material is reduced by at least 2 times after being heated above the corresponding threshold temperature.

6. The apparatus according to claim 1, characterized in that the solid organic substances of the thermosensitive material are selected from: aliphatic acids containing at least 13 carbon atoms; salts of fatty acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkyl phosphinic acids containing at least 16 carbon atoms; amides of fatty acids containing at least 3 carbon atoms; fatty acid anhydrides containing at least 22 carbon atoms; fatty alcohols containing at least 16 carbon atoms; aliphatic amines containing at least 17 carbon atoms; nitriles of fatty acids containing at least 20 carbon atoms or mixtures thereof.

7. The apparatus according to claim 1, characterized in that the solid organic substances of the thermosensitive material are selected from: palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearyl alcohol, cetyl alcohol, dispersed polyethylene, saturated fatty carboxylates of rare earth metals (especially lanthanum, yttrium, ytterbium, scandium).

8. The apparatus according to claim 1, characterized in that the microstructure of at least one thermosensitive material further contains a polymer binder transparent to at least part of visible light, and its content is 1-30% by mass.

9. The apparatus according to claim 1, characterized in that The device is made in the form of a sticker and includes an insulating layer, an adhesive layer, and an elastic substrate that is opaque to at least part of visible light. The elastic substrate is made of a halogen-containing polymer, has a thickness of less than 1 mm, and a dielectric strength of at least 5 kV / mm. At least one thermosensitive material is applied to various parts of the substrate with a thickness not exceeding 800 microns. The thermosensitive material is designed to cause an irreversible change in transparency in less than 5 seconds when the corresponding threshold temperature indicated on the device is reached.

10. The device according to claim 1, wherein, the device is made in the form of an elastic hollow tube for placement on an electric wire, and the surface of the electric wire serves as the substrate, which 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 at least 5 kV / mm. At least one thermosensitive material with a thickness not exceeding 800 microns is applied to various parts of the front surface of the device. The thermosensitive material is designed to cause an irreversible change in transparency in less than 5 seconds when the corresponding threshold temperature indicated on the device is reached.

11. The device according to claim 1, wherein, the device is made in a tubular shape and includes a longitudinal part for fixing to an electric wire. The surface of the electric wire serves as the substrate, which 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 at least 5 kV / mm. At least one thermosensitive material with a thickness not exceeding 800 microns is applied to various parts of the front surface of the device. The thermosensitive material is designed to cause an irreversible change in transparency in less than 5 seconds when the corresponding threshold temperature indicated on the device is reached.

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

13. The device according to any one of claims 9 - 11, wherein, the surface area of the base covered with at least one thermosensitive material is at least 100 mm.

14. The device according to claim 1, wherein, it is designed to be able to record the point heating of a controlled surface by only changing the transparency of the area in the thermosensitive material that is heated above the threshold temperature.

15. A method for manufacturing a device for visually recording a temperature rise exceeding at least one threshold according to claim 1, comprising the following steps: - applying one or more layers of at least one suspension to various parts of an opaque substrate, the suspension consisting of solid organic matter particles with a boiling point below 180 °C and the solubility of the solid organic matter particles in the liquid phase not exceeding 10 g / kg; - removing the liquid phase from the application layer of the suspension of solid organic matter particles in the liquid phase to form a thermosensitive material that is opaque to at least part of visible light, the microstructure of which includes solid organic matter particles and voids filled with a gas phase; - covering the front surface of the workpiece with a transparent protective layer, wherein at least one of the above steps is carried out under a pressure lower than atmospheric pressure.

16. The method according to claim 15, wherein, the substrate includes a halogen-containing polymer.

17. The method according to claim 15, wherein, the solid organic substances of the thermosensitive material are selected from: aliphatic fatty acids containing at least 13 carbon atoms; salts of fatty acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkyl phosphinic acids containing at least 16 carbon atoms; amides of aliphatic acids containing at least 3 carbon atoms; fatty acid anhydrides containing at least 22 carbon atoms; fatty alcohols containing at least 16 carbon atoms; aliphatic amines containing at least 17 carbon atoms; nitriles of fatty acids containing at least 20 carbon atoms or mixtures thereof.

18. A method for manufacturing a device for visually recording a temperature rise above at least one threshold according to claim 1, comprising performing at least 3 cycles, each cycle comprising applying a suspension layer of at least one solid organic substance particle in a liquid phase to respective parts of an opaque substrate and removing the liquid phase from the applied layer, and subsequently coating the front surface of the workpiece with a transparent protective layer, wherein the boiling point of the liquid phase is below 180 °C, wherein, the suspension of solid organic substance particles in the liquid phase is applied by a method selected from: screen printing, flexographic printing, pad printing, screen printing, to produce a microstructure of at least one thermosensitive material, wherein the particles of the solid organic substance are mainly oriented parallel to the plane of the base surface.

19. The method according to claim 18, wherein, the substrate comprises a halogen-containing polymer.

20. The method according to claim 18, wherein, the solid organic substances of the thermosensitive material are selected from: aliphatic acids containing at least 13 carbon atoms; salts of fatty acids containing at least 12 carbon atoms; alkanes containing at least 20 carbon atoms; dialkyl phosphinic acids containing at least 16 carbon atoms; amides of aliphatic acids containing at least 3 carbon atoms; fatty acid anhydrides containing at least 22 carbon atoms; fatty alcohols containing at least 16 carbon atoms; aliphatic amines containing at least 17 carbon atoms; nitriles of fatty acids containing at least 20 carbon atoms or mixtures thereof.

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