Temperature indicator and method of manufacturing and testing same

Abstract

A temperature indicator for visibly indicating that a temperature has exceeded a threshold value comprises a base, a gas-filled hot-melt material capable of undergoing an irreversible change in transparency when heated above a threshold temperature, and a protective layer, wherein at least some of the gas-filled hot-melt material is disposed between support elements configured in the material of the base and / or of the protective layer. Support elements may also be configured inside the gas-filled hot-melt material. Methods of manufacturing and testing such temperature indicators are also disclosed. The technical result is the creation of temperature indicators containing a gas-filled hot-melt material which are able to withstand mechanical stresses while retaining their functional characteristics.

Description

[0001] THERMOINDICATOR, METHOD OF ITS MANUFACTURING AND TESTING

[0002] The field of technology to which the group of inventions belongs

[0003] The group of inventions relates to devices for visually recording the fact of exceeding at least one temperature threshold value, namely, to irreversible thermal indicators resistant to mechanical impacts, the operating principle of which is based on the melting of a heat-sensitive component, as well as to methods for their manufacture and testing.

[0004] State of the art

[0005] An increase in temperature is one of the first and most common signs of developing defects in various equipment, such as increased contact resistance, interturn short circuits in electric motor windings in the power industry, failure of chargers or batteries in household appliances, and bearing malfunctions in mechanical equipment. Early detection of such overheating allows for troubleshooting and preventing equipment failure, emergency situations, and associated fires or outages.

[0006] Technical and regulatory documents establish maximum permissible temperatures, heating above which should be considered a defect requiring immediate cessation of operation and removal of the equipment for repair (for example, 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.).

[0007] Among the known methods of temperature monitoring, temperature-indicating monitoring is currently widely used. It relies on the use of temperature indicators (TIs), which can be devices attached to the monitored surface, potentially subject to heating, or devices attached to elements of the monitored object, containing temperature-sensitive components that detect when one or more threshold temperatures are exceeded based on changes in the indicator's appearance.

[0008] Such temperature sensors can be either reversible, meaning they change their appearance only when heated and return to their original state upon cooling, or irreversible, meaning they change their appearance after exceeding a predetermined temperature and retain it after cooling. A distinctive feature of reversible temperature sensors is that they only provide information about whether the temperature exceeds threshold values ​​at the time of inspection and also provide information about current overheating.

[0009] Irreversible thermal indicators allow for the detection of overheating throughout its entire lifespan, regardless of the electrical equipment's operating condition at the time of inspection. Unlike reversible thermal indicators, irreversible thermal indicators change color upon overheating and remain essentially unchanged.

[0010] The importance of using irreversible temperature indicators for diagnosing electrical equipment is revealed, in particular, in the work of Lvov M. Yu., Lesiv A. V. Temperature indicator monitoring of contacts and contact connections of electrical equipment and power transmission lines. Moscow: NTF "Energoprogress", "Energetik", 2023. P. 62. In the article by Lvov M. Yu., Nikitina S. D., Lvov Yu. N., Lesiv A. V. On the standardization of requirements for temperature indicator monitoring of the state of contacts and contact connections during the operation of electrical installations / / Energy of the unified grid. 2023. No. 1 (68). P. 67-74. typical requirements for temperature indicators, principles of their selection and methodology for assessing the state of controlled objects using temperature indicators are presented. Among other things, it is noted that only irreversible temperature indicators should be used to monitor the state.

[0011] Irreversible fault detection systems can be implemented in single-temperature or multi-temperature versions. Single-temperature fault detection systems detect when a specified temperature has been exceeded, for example, the maximum permissible temperature specified for the monitored electrical devices and components of electrical installations. Such single-temperature fault detection systems allow personnel to be promptly informed of the occurrence of an emergency or pre-emergency situation, but do not allow the determination of the extent of the defect.

[0012] Irreversible multi-temperature testing allows us to determine not only whether a predetermined temperature has been exceeded, but also the numerical value of the maximum surface temperature of the test object, from a set of available measurable values, to which the test element has heated up during operation. This allows us to track the dynamics of defect development, enable comparison of overheating temperatures of identical equipment components, and determine the excess temperature, defect rate, and their maximum values.

[0013] The key technical characteristics of the TI, which enable their use in identifying defects in industrial and energy equipment, are: - irreversibility and non-return of operation, i.e. the absence of a return to the original color of the triggered TI during prolonged exposure after operation under a wide variety of conditions;

[0014] - long service life;

[0015] - accuracy of recording the set temperature;

[0016] - no response during prolonged exposure of the TI at a temperature slightly below the threshold;

[0017] - maintaining operability and the above-stated characteristics over a wide range of ambient temperatures and under adverse influences.

[0018] Among the wide variety of temperature-indicating compounds, the above requirements are best met by heat-sensitive materials whose operating principle is based on a phase transition. The change in appearance manifests itself as an increase in the transparency of the heat-sensitive material due to its melting upon reaching a threshold temperature.

[0019] Their advantages stem from the fact that the phase transition (in this particular case, the melting of the heat-sensitive component) is determined by temperature and, for individual substances, is within a narrow temperature range, preferably less than one degree Celsius. Furthermore, the phase transition does not occur even if the heat-sensitive component is held at a temperature lower than the phase transition temperature, such as the melting point, for any length of time. Conversely, the phase transition is guaranteed to occur when the heat-sensitive component is heated above the phase transition temperature.

[0020] Known in the art are heat-sensitive materials whose operation is based on the melting of a heat-sensitive component. The change in appearance of the device containing them is due to the absorption of the molten heat-sensitive material by the substrate material. Heat indicators typically use a paper backing to absorb the molten heat-sensitive material. Disadvantages of paper include its insufficient strength and flammability, making such heat indicators unsuitable for use in electrical installations.

[0021] The description of the invention to application US20060011124 (published July 15, 2004) discloses a temperature sensor in the form of a label, characterized in that the temperature-sensitive part has a wax layer formed on the painted surface of colored paper of arbitrary flat shape, wherein the wax layer is formed from a mixture of the required amount of viscous material and petroleum wax powder melting at a predetermined temperature, attached to a sheet base, wherein the wax layer is located close to the front surface of the temperature sensor, and the entire front surface of the temperature sensor is covered with a transparent film. The wax applied to the colored paper base becomes transparent upon reaching the melting temperature and impregnates the paper base, revealing its color.

[0022] The porous absorbent base materials used in thermal measuring devices (TM) have low thermal conductivity. This is due to the high air content in the absorbent layer. Low thermal conductivity slows down the heat transfer from the monitored surface to the temperature-sensitive material. This leads to a delay in the phase transition of the temperature-sensitive material, reduced temperature recording accuracy when the ambient temperature differs significantly from the monitored surface temperature, and the inability to detect short-term overheating. Also, due to heat dissipation, such TMs do not allow for the precise determination of the surface heating isotherm contour above the TM's response temperature when detecting localized heating over a large surface. This can lead to errors in identifying the location of a defect, such as a breach in the insulation of a motor winding or transformer.

[0023] Furthermore, to ensure coverage of the substrate, a thicker layer of temperature-sensitive material is required. This leads to a slower detection rate for exceeding threshold temperatures, as well as a decrease in the overall flexibility and elasticity of the device. This, in turn, can lead to cracks in the temperature-sensitive layer when installed on curved surfaces, especially those with a small radius of curvature.

[0024] To address these shortcomings, the authors of this application developed temperature indicators incorporating a gas-filled hot-melt material (GFHM). These materials exhibit high opacity due to the extensive solid phase surface area within the material and a large number of light refraction points at the gas-solid interface. GFHMs have low volumetric specific heat capacity and are therefore capable of irreversibly increasing their transparency with high precision and speed upon melting their heat-sensitive substance. The irreversibility of the color transition is ensured by the fact that melting the substance or group of substances included in the GFHM disrupts the structure of the material and separates the gas and liquid phases, increasing transparency. Upon subsequent cooling, recombination of these phases to return the material to its original opaque structure is impossible.The hiding power of the solidified solid phase formed after cooling the hot-melt material is reduced compared to the initial state due to the reduction of the gas-solid phase boundaries, where reflection and scattering of light occurs.

[0025] An example of such a thermal insulation material is the material used in the thermal indicator sticker disclosed in the description of the utility model to patent RU 220377 (published 11.09.2023), which includes:

[0026] - a base that is opaque to at least part of the visible light;

[0027] - a heat-sensitive material that is opaque to at least part of the visible light and applied to the front surface of the base, the microstructure of which in its initial state includes particles of the solid phase and predominantly interconnected voids filled with the gas phase;

[0028] - a transparent protective layer covering a heat-sensitive material; the heat-sensitive material is designed to irreversibly change its transparency upon reaching a threshold temperature due to the fusion of the particles that form its microstructure and the release of the gas phase from the heat-sensitive material to the surface. The known TI has a response accuracy of + / - 2°C relative to the threshold temperature, and its response time is no more than 2 seconds. Once triggered, the TI does not return to its original appearance after cooling and holding at 20°C for an extended period of time, estimated at several years.

[0029] The description of the invention to patent RU 2800396 (published 21.07.2023) proposes a device for visually recording a temperature rise above at least one threshold value, having a layered structure including:

[0030] - a base that is opaque to at least part of the visible light, on the front surface of which inscriptions are applied indicating at least one numerical threshold temperature value;

[0031] - at least one heat-sensitive material, opaque to at least part of the visible light, applied to individual sections of the base, the microstructure of which includes particles of solid organic matter and voids filled with a gas phase;

[0032] - a transparent protective layer partially or completely covering the front surface of the device; wherein in the initial state the particles of the solid organic substance are predominantly oriented parallel to the surface of the base, and the device is designed with the ability to irreversibly change its appearance upon reaching at least one threshold temperature indicated thereon due to the destruction of the microstructure of the corresponding heat-sensitive material, accompanied by the fusion of the particles of the solid organic substance, a decrease in the proportion of voids by at least 2 times relative to the initial state and an increase in its transparency with the manifestation of the color of the base.

[0033] Thus, the use of fusible substances in a heat-sensitive material ensures high response accuracy and a long service life, and the introduction of a significant amount of gas phase into the heat-sensitive material with the formation of a gas-temperature thermal material makes it possible to obtain heat-sensitive materials with a minimum thickness while maintaining high hiding power and a high brightness factor, having high speed, accuracy and irreversibility of response.

[0034] However, despite the significant advantages of the thermally sensitive material, the presence of a large amount of gas in the structure of the heat-sensitive material makes it brittle. Specifically, applying pressure to the thermally sensitive material can destroy the original structure of the thermally sensitive material, while vibration can cause abrasion, with some of the thermally sensitive material separating from the substrate surface. As a result, the thermally sensitive material ceases to provide adequate coverage, with a decrease in luminance. The observed slight increase in the thermally sensitive material's transparency can be interpreted as a false alarm from the thermally sensitive material.

[0035] A similar picture is observed when liquids enter the gas-solid composite material. As liquid penetrates the pores of the gas-solid composite material, its hiding power is significantly reduced, and the material becomes transparent due to a decrease in the refractive index when transitioning from a gas-solid to a liquid-solid system, which also appears as a false alarm.

[0036] The operating conditions of equipment and mechanisms whose components require temperature control typically include adverse external factors, such as mechanical stress (e.g., impact loads and vibration), atmospheric moisture, and aggressive vapors and / or liquids. Therefore, when using thermally sensitive materials containing thermally sensitive materials in such industrial equipment, they must be coated with a protective film to reduce the impact of these factors on the temperature-sensitive material.

[0037] As the closest analogue, the authors of the proposed invention consider a temperature indicator sticker for irreversibly recording a temperature rise above at least one threshold value, including: an adhesive layer that provides adhesion of at least 10 N / 25 mm to stainless steel, measured by the FINAT TM1 method after 24 hours; a flexible base onto which information elements are applied, including the numerical value of at least one threshold temperature, and at least one heat-sensitive material covered with a protective polymer film, which:

[0038] - in its original state it is opaque to at least part of the visible light;

[0039] - designed with the ability to irreversibly increase transparency when heated above a threshold temperature;

[0040] - includes polymeric substances; contains voids distributed throughout the volume, the proportion of which in the heat-sensitive material is at least 10% by volume, as disclosed in the description of the utility model to patent RU 221997 (published December 5, 2023). However, despite the presence of a protective layer, the GTPM of the known TI is not protected from mechanical impacts, in particular, from pressure.

[0041] Temperature-monitored equipment, as well as the temperature-monitoring devices installed on it, may be subject to strong mechanical stress. For example, applying a temperature-indicating sticker requires pressure on its surface. Such stress, even with a protective layer, can damage the integrity of the thermal-indicating device and cause false alarms.

[0042] Installing a temperature indicator with a GTPM on curved surfaces may result in cracks forming in it, its partial peeling off from the base, as well as a decrease in the speed, accuracy, and reliability of overheating detection.

[0043] Thus, there is a need to create irreversible TIs with HTPM that would be resistant to mechanical influences while maintaining functional characteristics, as well as to create methods for manufacturing such TIs and testing them for resistance to mechanical influences.

[0044] Terms, definitions and abbreviations used in the description of this group of inventions

[0045] The following terms, definitions and abbreviations used in the description of the present group of inventions are intended for a better and more precise understanding of the present group of inventions, but do not limit the present group of inventions to the specified wording.

[0046] The term "thermal indicator (TI)" refers to a device that changes its appearance (specifically, color) when heated above one or more threshold temperatures. Typically, a thermal indicator consists of a base, designed to secure the thermal indicator to the monitored surface, with one or more temperature-sensitive elements located on the front side of the base that change color when heated.

[0047] A change in the appearance of a thermosensitive element that occurs solely as a result of heating the thermosensitive element to any of the possible temperature thresholds is referred to as "triggering the thermosensitive element." In the context of the present invention, triggering the thermosensitive element is achieved by melting the active substance of the thermosensitive element.

[0048] Single-temperature temperature indicators include those that have one temperature-sensitive element or several temperature-sensitive elements that are triggered when one threshold temperature is reached.

[0049] Multi-temperature thermal indicators include TIs that have several temperature-sensitive elements that differ in response temperature.

[0050] A change in the appearance of the TI, in particular the color and / or transparency in the area of ​​the temperature-sensitive element, which occurs as a result of an external influence other than heating the TI above the corresponding temperature threshold values, is called a “false triggering of the TI”.

[0051] The term "irreversible thermal indicator" defines a thermal indicator that, after heating to the operating temperature, visually changes its appearance, in particular its color, in such a way that after cooling below the operating temperature, its appearance does not return to a form that is visually indistinguishable from the original.

[0052] The term "non-reversibility of a thermal indicator" refers to the long-term preservation of the appearance of the activated thermal indicator under all operating conditions throughout its entire service life. Preferably, the specified service life of the thermal indicator according to the present invention is 2 years, more preferably 5 years, and even more preferably 10 years.

[0053] The term "gas-filled hot-melt material" (GFTM) defines a material comprising a solid phase or phases, as well as a gas phase contained within the cavities of the solid phase. At least one of the solid phases of the GFTM, referred to as the "hot-melt phase," is capable of melting when heated to a threshold temperature. The gas phase is predominantly distributed uniformly throughout the GFTM, with most of the pores interconnected, allowing for unimpeded gas distribution and escape during heating and / or melting of the material. The gas pressure within the pores may be less than atmospheric pressure, equal to atmospheric pressure, or greater than atmospheric pressure.

[0054] The hot melt phase contains the "active (main) substance of the thermal melting point material"—a substance, specifically an organic compound, that determines the melting point of the thermal melting point material (the threshold temperature for the activation of the thermal melting point). The mass content of the active substance in the thermal melting point material structure generally exceeds the content of other components of the thermal melting point material. This term also applies to a mixture of such substances.

[0055] "The response speed of the TI" is the maximum time required for the transition of the TI from the initial to the triggered state after heating to the response temperature, taking into account the specified accuracy of recording the excess of the threshold temperature.

[0056] For the purposes of the claimed group of inventions, the term “threshold temperature” means the temperature value at which a change in the appearance of the temperature indicator occurs, determined with a given accuracy.

[0057] The term “maintenance of functional characteristics” includes the maintenance of the functional characteristics of the thermal indicator (for example, the value of the threshold temperature, the opacity of the thermal indicator, the brightness coefficient of the thermal indicator, the accuracy and speed of recording the excess of the threshold temperature, etc.) within the limits established by the manufacturer throughout the established service life in all operating modes.

[0058] The “brightness coefficient” is defined according to GOST 8784-75 as the ratio of the brightness of the coating to the brightness of the standard, measured under the same lighting conditions with a light incidence angle of 45°.

[0059] The term "loss of functional characteristics" encompasses the disruption of one or more elements of a measuring instrument, causing it to completely or partially cease to perform its functions. Specifically, loss of functional characteristics includes a change in the threshold response temperature, a significant reduction in the contrast of the color change upon activation, a change in the appearance of the measuring instrument before or after activation, and other defects that lead to incorrect operation of the measuring instrument or misinterpretation of temperature monitoring results.

[0060] The term "organic substances" restricts the class of chemical substances that contain carbon atoms bonded to atoms of other chemical elements, excluding metal carbides, metal and ammonium carbonates, and carbon oxides.

[0061] The term "gas phase" by default refers to the gas-filled pores within the gas-filled pore space of the thermal indicator. The gas phase may be air, nitrogen, inert gases, or other substances in the gas state under the operating conditions of the thermal indicator. The term "gas phase fraction in the gas-filled pore space" refers to the ratio of the pore volume within the gas-filled pore space to the total volume of the gas-filled pore space, or the ratio of the area of ​​gas-filled sections to the total area of ​​the gas-filled pore space in one section of the gas-filled pore space. For the purposes of this group of inventions, the gas phase fraction may be determined by one of the following methods.

[0062] The first method involves scanning electron microscopy of the surface of a section of the gas-filled slurry using software that calculates the total external surface area of ​​the sample's solid particles and their agglomerates in the section. The area of ​​gas-filled regions is calculated by subtracting the total surface area of ​​the solid particles and their agglomerates from the area of ​​the analyzed region. To determine the proportion of the gas phase, the resulting value for the area of ​​gas-filled regions is divided by the area of ​​the analyzed region. Measurements are performed on 5-7 sections of the gas-filled slurry, and the average value is calculated.

[0063] The second method is based on X-ray microtomography. Sample preparation is similar to the first method. A section of the gas-phase material of known volume is analyzed using a laboratory digital X-ray tomograph with software capable of calculating the percentage of gas in a given sample volume. Measurements are taken from 5-7 sections of the material, obtaining an average value for the gas phase content, expressed as a percentage.

[0064] Any method for determining the gas phase fraction can be applied to finished products containing gas-phase-contaminated materials, such as TI. During sample preparation, a homogeneous section of the product is cut out and the protective layer is removed to ensure the integrity of the gas-phase-contaminated material.

[0065] In the context of describing a gas-phase flow system, a "phase" refers to the homogeneous part of the gas-phase flow system, separated from the remaining parts by a visible interface where certain phase characteristics, such as density, composition, or optical properties, change abruptly. The collection of individual homogeneous parts of the system, each possessing identical properties, is considered a single phase.

[0066] The composition of the thermal melting point material (TMP) may additionally include particles of a solid substance with a melting point above the threshold temperature, the strength of which predominantly exceeds that of the thermal melting phase, polymers that completely or partially coat the thermal melting phase, and other inclusions. Such substances or inclusions are used to increase the mechanical strength of the TMP. In this group of inventions, the TI may include either a single TMP for recording the exceeding of a single threshold temperature, or multiple TMPs for recording the exceeding of multiple threshold temperatures.

[0067] The term "GTPM structure" defines the spatial arrangement of solid particles and gas-filled pores in a GTPM sample. The GTPM structure determines its physical, optical, and mechanical properties. Upon reaching a threshold temperature, melting of at least one of the solid phases of the GTPM occurs. During the melting process, the GTPM structure changes, that is, the spatial arrangement of particles and / or volumes of individual phases of the material, their size, and shape. The destruction of the structure may include the following stages: melting of the GTPM particle surface, their compaction, reduction of the pore size within the GTPM and the gas-solid interface area, and particle fusion up to their complete fusion and the formation of a monolithic layer (melt) or a single phase. The process of GTPM structure destruction is accompanied by an irreversible decrease in the volume fraction of the gas phase within the GTPM. The proportion of the gas phase in the material obtained after the activation of the thermal insulation device is less than in the initial state of the GTPM.

[0068] For the purposes of the claimed group of inventions, the term “threshold temperature” means the temperature value at which a change in the appearance of the temperature indicator occurs, determined with a given accuracy.

[0069] The term “accuracy of recording the excess of the threshold temperature” means the boundaries of the range of temperature values ​​that meet the following conditions

[0070] (1) - (3):

[0071] (1) until the threshold temperature is reached minus the specified accuracy value, the corresponding HTPM remains opaque to at least part of the visible light, and the TI in this region does not change its appearance;

[0072] (2) when the threshold temperature is exceeded, taking into account the specified accuracy, the corresponding GTPM visually increases its transparency, and the TI in this area acquires an appearance different from the original;

[0073] (3) The exact value of the phase transition temperature of the melting of the base material is within a specified range and is not further specified. The accuracy of recording the excess of the threshold temperature defined by this group of inventions is no more than 5°C, preferably no more than 2°C.

[0074] The term "visible light" defines a narrow region in the electromagnetic spectrum in the frequency range of 3.8 - 10 14 - 7.9 - 10 14 Hz, which corresponds to wavelengths in a vacuum from ~400 to ~760 nm, which are detectable by the human eye. The term "opaque to at least some visible light" refers to a material that does not transmit all or part of the visible light spectrum.

[0075] The term "transparent to at least part of the visible light spectrum" means a material that allows all or part of the visible light spectrum to pass through.

[0076] The term “support element” or “support element (SE)” defines an arbitrary element located in the area of ​​the GSPM, which has a melting temperature greater than the maximum operating temperature of the TI, and which can take on most of the mechanical stress acting on the GSPM in the transverse direction, thereby preventing significant destruction of the GSPM structure.

[0077] The term "distance between support elements" L(S) refers to the distance between the vertices of adjacent support elements. For support elements located on the base or on the protective layer or formed in the base or in the protective layer, L(S) on the plane A-A (Figs. 3, 4, 5) is the distance between the perpendiculars to the surface plane of the thermal indicator, emanating from the vertices of adjacent S. For support elements located in the volume of the GTPM, L(S) is calculated as the distance between the perpendiculars dropped from the vertices of these elements onto the surface plane of the thermal indicator B-B (Figs. 3, 4, 5).

[0078] The term "adjacent supporting elements" located on the base or on the protective layer or made in the base or in the protective layer defines EO, between the vertices of which there are no other supporting elements of comparable size, that is, the effective height of which differs by no more than 3 times.

[0079] "The top of the supporting element" is a point or a small area on the surface of the supporting element to which the maximum load from the external impact on this supporting element will be applied.

[0080] “Normal section of the TI” is a part of any plane intersecting the volume of the TI and perpendicular to the plane of the working surface of the TI (A-A, Fig. 4).

[0081] The term “the plane of the working surface of the TI” defines the plane of the TI, parallel to the surface (or tangent to the surface for TI intended for installation on cylindrical surfaces), on which the TI can be placed (B-B, Fig. 4).

[0082] "The main area of ​​the TI (OOTI)" is the area bounded by perpendiculars dropped onto the plane of the working surface of the TI from the vertices of the extreme EO and intersecting it at points Mo, Mi, and the inner surface of the base and the protective layer. "The average thickness of the GTPM layer Ь С p(GTPM)" in the general case is the quotient of the volume of the OOTI and the area of ​​the working surface of the TI. In any normal section of the TI h cp (GTPM) is defined as the quotient of the area of ​​the GTPM in this section and the distance between the perpendiculars dropped from the vertices of the extreme EO to the plane of the working surface of the TI.

[0083] "The effective height of the support element Ьэф(ОЭ)" for support elements located on the base or protective layer, or made in the base or protective layer, corresponds to the length of the perpendicular segment dropped from the top of the EO to the plane of the working surface of the TI to the point of intersection with the segment Co-Ci, which shows the maximum linear dimension of the EO at its base. For EO located in the volume of the GTPM, ЬЭ φ(SE) corresponds to the length of the segment lying on the perpendicular dropped from the apex of the SE to the plane of the working surface of the TI and connecting the two extreme points of the SE, one of which is its apex. The area of ​​the SE above (in the case of SE located on the base or made in the base material, as well as in the case of SE located in the volume of the GTPM) or below (in the case of SE located on the protective layer or made in the material of the protective layer) the segment Co-Ci (shaded in Fig. 4a, b) is the effective area of ​​the support element, due to which the element performs its functions disclosed within the framework of the claimed group of inventions.

[0084] The "average effective height of the supporting elements" in any normal section of the TI is equal to the arithmetic mean of the effective heights of all the supporting elements in this section.

[0085] "Base thickness Ь Сp(Osn)”, containing the EO located on the base or executed in the base, for each normal section of the TI is an average value equal to the quotient of the total area of ​​the base within the OOTI, including support elements, if present in the OOTI, and the distance between the perpendiculars dropped from the vertices of the extreme EO to the plane of the working surface of the TI and intersecting it at points Mo, Mi.

[0086] "Thickness of the protective layer h C p(3C)”, containing the protective elements located on the protective layer or made in the protective layer, for each normal section of the TI is an average value equal to the quotient of the total area of ​​the protective layer within the TI, including support elements, if any, in the TI, and the distance between the perpendiculars dropped from the vertices of the extreme protective elements to the plane of the working surface of the TI and intersecting it at points Mo, Mi.

[0087] By "hermetic protective layer" is meant a protective layer that is impermeable to air and water at atmospheric pressure in the absence of mechanical impact, made without gaps or holes and tightly connected to the base by welding or gluing in such a way that the joint is also impermeable to air and water at atmospheric pressure and in the absence of mechanical impact.

[0088] “Isolated GTPM” means a GTPM covered with a protective layer in such a way that when a fragment of the TI is immersed in water to a depth of up to 1 meter at atmospheric pressure and in the absence of mechanical impacts, there is no direct contact of the GTPM with water for at least one day.

[0089] The term "welded protective layer" refers to the bonding of the protective layer and the base materials through mutual dissolution. This bonding can be achieved through the use of a solvent, fusion, heating, compression, or other means.

[0090] The term "completely isolating from the environment" refers to the property of the protective layer to ensure the tightness of the gas-insulated protective layer, as well as to prevent communication of the gas-insulated protective layer with the environment and to ensure the maintenance of the operability of the TI under adverse external influences, including atmospheric moisture, splashes, certain industrial pollutants, mechanical impact, etc.

[0091] The "partially isolating from the environment" layer prevents the impact of unfavorable external factors on the device and, thus, provides its protection, but does not ensure the tightness of the gas-phase device, as a result of which the pressure of the gas phase inside the gas-phase device is equal to the pressure of the surrounding environment.

[0092] The term "elasticity" refers to the ability of a material or product, when bent around a cylindrical surface, to conform to its shape without losing its functional properties.

[0093] The terms "elastic base" and "elastic protective layer" characterize the base or protective layer material, which is capable of changing its shape without breaking under external influence.

[0094] The term “defect” indicates the non-compliance of the control object with the requirements established by the documentation, at least for one indicator.

[0095] The "defect ratio" is the ratio of the measured temperature rise of the contact connection to the temperature rise measured on the entire section of the busbar or wire, located at a distance of at least 1 m from the contact connection.

[0096] "Excessive temperature" is the excess of the measured temperature of the monitored object over the temperature of similar components in other phases under identical conditions. The term "fire-hazardous heating" refers to the heating of an electrical installation component to a temperature that poses a risk of ignition of one or more of the components' materials.

[0097] The term "flexible" refers to materials that have the ability to change their shape under external influence in such a way that after returning to their original shape, their functional properties remain the same.

[0098] The terms "flexible / elastic base" and "flexible / elastic backing layer" describe the base or backing layer material, which refers to materials that have the ability to change their shape without breaking under external influence.

[0099] A "binder" refers to a material or substance, typically a high-molecular organic compound, which can be one of the components (or phases) of the thermal-thermal-melting composite (TMP) in temperature indicators. The binder stabilizes the solid particles in the solid TMP so that gas-filled voids are located between them. The binder also increases the strength of the TMP, reduces its abrasion, and can also ensure the adhesion of the TMP to the absorbent phase, as well as the absorbent phase to the surface of the temperature indicator.

[0100] The essence of the group of inventions

[0101] The objective of the claimed group of inventions is to create irreversible thermal indicators (TI) resistant to mechanical stress, whose operating principle is based on the irreversible change in the transparency of a gas-filled hot-melt material (GFTM). The group of inventions also aims to develop methods for manufacturing such TI and a method for testing their resistance to mechanical stress.

[0102] The technical result of the claimed group of inventions consists in increasing the safety of equipment operation, as well as increasing the resistance of irreversible TI to mechanical impacts while maintaining the functional characteristics of the GTPM contained in them.

[0103] According to the first variant, the specified technical result is achieved by means of a temperature indicator for visually recording the temperature exceeding at least one threshold value, including:

[0104] - basis;

[0105] - at least one gas-filled hot-melt material (GFTM), located on the section / s of the front surface of the base, designed with the possibility of an irreversible change in transparency when heated above a threshold temperature due to the melting of a substance or group of substances included in the GFTM;

[0106] - a protective layer, transparent to at least part of the visible light, covering the HTPM, and at least part of the base free from the HTPM, wherein at least part of the HTPM is located between support elements (SE) made in the material of the base and / or protective layer.

[0107] The use of gas-temperature measuring devices, the operation of which is based on an irreversible change in transparency upon reaching the corresponding threshold temperature, due to the fusion and / or melting of the main substance or mixture of main substances included in the gas-temperature measuring device, and the release of at least part of the gas from the volume of the gas-temperature measuring device, makes it possible to irreversibly record the excess of at least one threshold temperature value with high accuracy, speed and reliability.

[0108] Until the corresponding threshold temperature is exceeded, the gas within the gas-solid phase control module (GPM) is distributed predominantly uniformly. This uniform gas distribution within the GPM creates multiple gas-solid interfaces, at which light is refracted and reflected. This GPM design significantly reduces the layer thickness required to cover the base material, compared to the layer thickness of a similar substance without a gas phase. Reducing the GPM layer thickness ensures high speed, precision, and irreversibility. Ultimately, the use of GPMs, including those with a predominantly uniformly distributed gas phase, improves the reliability and accuracy of overheat detection.

[0109] When the TI is heated to the appropriate threshold temperature, gas is irreversibly released from the TGPM, the TGPM "subsides," i.e., its layer thickness decreases, and its transparency increases. Initially, only the lower layer of the TGPM, which is in direct contact with the substrate adjacent to the surface of the test object, melts. Subsequent elements of the TGPM volume, which were not in contact with the substrate initially, are immersed in the resulting melt, releasing gas from their structure. Moreover, melting of the base material within the TGPM immersed in the melt at the appropriate response temperature occurs significantly faster than melting of the material surrounded by gas. This latter response ensures high TGPM response speed and enables the detection of even short-term heating to temperatures exceeding at least one threshold value.Using a large-area HTMS allows one to determine which portion of the monitored surface was heated above the threshold temperature. The color change of the HTMS as the HTMS transparency increases occurs only in the portion of the HTMS that was heated above the corresponding threshold temperature, while maintaining the original appearance of other portions of the HTMS whose temperature did not exceed the corresponding threshold temperature. This property of the HTMS allows one to record the isotherm contour of the surface heating above the HTMS response temperature and pinpoint the location of a defect in the monitored equipment with high accuracy.

[0110] Due to the thin layer thickness of the gas-thermal composite material and the low heat capacity of the gas, such thermal detectors allow for the detection of short-term overheating above the threshold temperature. The need to detect short-term overheating, such as that caused by short-circuit currents, surge voltages, inrush currents, and the like, is an important component of improving equipment operational safety.

[0111] However, as mentioned previously, the structure of the thermal indicator material is fragile and can be damaged by mechanical stress, such as pressure, friction, operation at elevated pressure, etc. This can lead to misinterpretation of temperature indicator test results, resulting in false, premature activation of the thermal indicator due to loss of coverage and a decrease in luminance due to mechanical damage to the thermal indicator material. Damage to the thermal indicator material's structure can reduce the speed and accuracy of response due to the formation of voids between the substrate and the thermal indicator material.

[0112] The use of a protective layer, at least partially transparent to visible light, covering the thermoplastic material and at least a portion of the base free of the thermoplastic material distributes the mechanical stress on the hot-melt material, but does not eliminate it completely. When the threshold temperature is exceeded and the thermoplastic material melts, the gas phase escapes from its volume into the space bounded by the protective layer. At the same time, the thermoplastic layer itself significantly decreases in thickness upon activation of the thermal insulation device.

[0113] In the course of extensive research, the authors of this group of inventions have found that the use of a base and / or protective layer comprising multiple support elements (SEs), between which at least a portion of the GSPM is located, protects the GSPM structure from mechanical impacts such as pressure, friction, increased pressure, etc., by redistributing the majority of the load from the GSPM to the base. When using SEs, at least a portion of the GSPM, preferably the majority of the GSPM, is located within the matrix formed by the SEs. In particular, when transverse pressure is applied to the GSPM, such as when installing a measuring instrument on equipment, the majority of the applied load will fall on the SEs rather than the GSPM. This will prevent damage to the GSPM structure and maintain its functional characteristics.

[0114] The presence of protective elements helps maintain the integrity of the device and its proper operation during installation, which is especially important when installing the device on curved surfaces with a small radius of curvature. This is because the protective elements also act as spacers for the PT layer, dividing it into isolated or non-isolated regions, each of which is many times smaller than the radius of curvature of the curved surface on which the device can be installed. When the device bends, the stress generated in the PT layer is exerted primarily on the base, protective layer, and multiple protective elements. This preserves the PT structure, which includes solid organic particles and the gas phase distributed between them, and, consequently, the required functional characteristics of the device.

[0115] The presence of protective elements made in the base and / or protective layer also allows for improving the appearance of the triggered TI, for example, avoiding the formation of large bubbles, due to the fact that when the TI is triggered, the protective layer is fixed on the protective element (Fig. 5 d, e).

[0116] Thus, the entire set of features of the first invention of the group ensures the stability of the irreversible TI to mechanical impacts while maintaining the functional characteristics of the GTPM, which increases the reliability of recording the excess of at least one threshold temperature value and the safety of operation of equipment equipped with such TI.

[0117] In particular cases, the protective element may comprise multiple projections on the surface of the base and / or protective layer, formed from the base and / or protective layer material, respectively, between which at least a portion of the CGPM is located, and / or recesses formed in the base and / or protective layer material, at least partially filled with the CGPM. In this case, each of these projections, as well as the surface between the recesses, will act as a protective element for the CGPM located in this region.

[0118] In addition to the support elements made of the base material and / or protective layer, additional protective elements may be located within the thermal-indicating layer (TIL) with a melting point higher than the TIL actuation temperature and a compressive strength higher than that of the TIL itself. The presence of such elements within the TIL itself will further enhance the strength and wear resistance of the thermal-indicating layer under mechanical stress by increasing the number of protective elements, thereby enhancing the technical result of the claimed group of inventions.

[0119] According to the second invention of the group, the said technical result is achieved by creating a TI for visually recording the excess of at least one temperature threshold value, including:

[0120] - basis;

[0121] - at least one gas-filled hot-melt material (GFTM), located on the section / s of the front surface of the base, designed with the possibility of an irreversible change in transparency when heated above a threshold temperature due to the melting of a substance or group of substances included in the GFTM;

[0122] - a protective layer, transparent, at least for part of the visible light, covering the TGPM and at least a part of the base free from the TGPM, wherein multiple support elements (SE) are located inside the TGPM, the melting temperature of which is higher than the operating temperature of the TGPM; the compressive strength of the SE is higher than the compressive strength of the TGPM.

[0123] In this case, the PTFE is a composite material. When applied to the substrate, the PTFE may already contain a protective element. The protective elements can also be placed on the substrate and / or protective layer prior to the PTFE application, which is applied sequentially or alternately so that the PTFE occupies the space between the protective elements. This arrangement of the supporting elements will protect the PTFE from mechanical stress and maintain the functional characteristics of the TI.

[0124] The melting point requirements for protective layers are explained by the fact that they must maintain their shape and strength upon activation of the thermal fusible material. It should be noted that above the activation temperature, protective layers are most sensitive to mechanical stress, since without a protective layer, the protective layer is effectively separated from the base by a liquid melt of the hot-melt material and air. The use of protective layers allows for the protective layer to be fixed relative to the base, even above the activation temperature, when the thermal fusible material cannot fix the protective layer relative to the base surface, as it is a liquid melt. It should be noted that in the first embodiment of the protective layer, this requirement is met by default, since in this case, the base and / or protective layer material melts significantly above the threshold temperature.The compressive strength of the OE must also be higher than the compressive strength of the GTPM, so that both before and after the operation of the TI, the majority of the mechanical impact, such as pressure, friction, increased pressure, etc., falls on the OE, between which at least part of the GTPM is located, preventing significant destruction of the GTPM structure.

[0125] The entire set of features of the second invention of the group also ensures the resistance of the TI to mechanical impacts while maintaining the functional characteristics of the GTPM, which increases the reliability of recording the excess of at least one threshold temperature value and the safety of operation of equipment equipped with such temperature indicators.

[0126] In one embodiment of the invention, at least some of the TEs touch or are attached to the base and / or protective layer. In this case, the TE may be similar in design to the TE of the first invention in the group, except that the TEs may be made of a material different from the base and / or protective layer, and that the TEs are not formed within the base and / or protective layer material itself, but are applied and / or attached thereto.

[0127] In this particular case, the supporting elements distributed within the PTFE volume should be made of an absorbent material that satisfies the above-mentioned conditions for melting point and compressive strength. This ensures that, in their initial state, the absorbent elements will perform a supporting function and prevent the PTFE structure from deteriorating under mechanical stress. As the PTFE melts, the absorbent elements will settle onto the surface of the substrate, thereby creating an absorbent layer. In addition to distributing the PTFE melt between the settled absorbent elements, it will also penetrate the pores and cavities of the absorbent elements, partially or completely filling them. This will result in the color of the substrate or the absorbent element (if an opaque absorbent material is used). The appearance of the TI will also not return to its original state upon further cooling.Distributing the activated heat-sensitive material between the particles of the OE will prevent cracking of the solidified layer of the thermally sensitive material during further operation of the monitored object and will increase the irreversibility of actuation during long-term exposure. Thus, the use of OEs capable of absorbing the melted thermally sensitive material when the threshold temperature is exceeded not only preserves the functional characteristics of the TI but also enables visual recording of exceeding the threshold temperature under mechanical, especially vibrational, influences and sudden and / or significant temperature changes. In preferred embodiments, the absorbent material is fibrous or porous, preferably microporous, most preferably with a pore diameter of no more than 2 µm. The absorbent material for the OE can be selected without limitation from, among others, fibrous material, microcellulose, polysaccharides, silica gel, zeolites, metal oxides, and aerosil.

[0128] The structure of the OEs distributed within the GFSM is preferably selected such that the OE transparency prior to GFSM activation is lower than that of the OEs wetted with the melt. In the initial state, the GFSM and OEs are distributed over the surface of the substrate in such a way as to cover the color of the substrate, achieving a high luminance factor (opacity). For this reason, it is preferable for the OEs included in the GFSM to be essentially opaque. However, after activation, the base material of the GFSM becomes transparent, while the OEs remain opaque, meaning the color of the substrate is not fully revealed (a so-called "whiteness" upon activation occurs). If the OEs initially have a branched, air-covered surface with multiple refractive boundaries at the gas-solid interface, and after activation they are wetted with the melt, the occurrence of whiteness after activation can be avoided.In other words, it is necessary that after exceeding the corresponding threshold temperature, the OE does not significantly overlap the color of the base and allows for the identification of the triggered TI with high accuracy and reliability.

[0129] In both the first and second embodiments, the TI may include either a single type of GTPM for recording the exceeding of a single threshold temperature, or multiple types of GTPM for recording the exceeding of multiple threshold temperatures. The TI may have one or more sections for each type of GTPM; in particular, GTPMs with different threshold temperatures may alternate, as shown in Fig. 8, or be arranged on the base in any arbitrary combination.

[0130] The number of thermal conductivity parameters is not upper-limited and depends on the practical task being implemented using the stated test method, the type of equipment, the required step size of the superheated temperature being determined, the surface area of ​​the test object, etc. In specific cases, three or four different thermal conductivity parameters are applied to the front surface of the base. Thermal conductivity parameters can be applied to both adjacent and non-adjacent areas of the front surface of the base.

[0131] Monitoring several threshold temperatures allows not only to determine the presence of a defect, but also to determine the degree of its development: the initial stage of defect development, an emergency defect, a fire-hazardous defect, as well as to determine the dynamics of defect development, to ensure a comparison of the heating temperatures of identical equipment components, contact connections, to determine the excess temperature and the defect coefficient.

[0132] For both embodiments, the preferred case is one in which at least part of the OE has a developed surface, i.e. not a smooth one, but a rough and / or porous structure, the specific surface area of ​​which is at least 0.2 m 2 / g. The influence of a developed surface area of ​​the OE on reducing whitishness during thermal insulation response was mentioned above. When fabricating a thermal insulation by applying the base material of the thermal insulation material as a suspension of particles in a solvent, it is preferable for the size of the irregularities and / or pores of the developed surface of the OE to be smaller than the size of these particles. This will ensure that the OE will be in contact with both the thermal insulation material particles and the gas phase, and the thermal insulation material in its initial state will not fill these irregularities in the OE. This will ensure optimal gas filling of the thermal insulation material, resulting in multiple light refraction regions at the gas-solid interfaces, both between the gas and the solid organic matter particles, and between the gas and the OE. The combination of the described thermal insulation material structure and the developed surface of at least part of the OE will ensure more effective color coverage of the base material with a thin layer of hot-melt material.

[0133] When the HTSM is activated, the molten base material will fill the irregularities and pores on the developed surface of the TE, smoothing it. This will lead to a significant reduction (preferably, to zero) in the number of gas-solid interfaces, with the base material color appearing. Gas from the HTSM structure itself, as well as from the pores and / or irregularities of the TE, will irreversibly escape to the surface of the hot-melt material. The reverse process of filling the molten hot-melt material with gas, restoring a structure close to the original HTSM structure, is impossible. Thus, the developed surface of the TE enhances the technical result due to the greater contrast of color change and the irreversibility of HTSM activation. The similar refractive indices of the TE and the base material of the HTSM further enhance the described result of using an TE with a developed surface.

[0134] As described above, the OE is in contact with both particles of at least one solid organic substance and the gas comprising the SGPM. However, it is preferable that the volume fraction of the gas phase in the regions between the OE and the SGPM be no more than 30%, and most preferably no more than 10%, of the SGPM volume. This is because the presence of a large air gap with a volume fraction of the gas phase between the OE and the SGPM exceeding the preferred values ​​will lead to stratification during heating of the TI, forming an "air bubble" near the base even before reaching the threshold temperature. Consequently, the heating of the SGPM will be slowed, which will negatively impact the speed and accuracy of overheat detection, especially if the ambient temperature and the heated surface of the test object differ significantly.The specified volumetric content of the gas phase between the GFSM and the FE, on the contrary, has a positive effect on heating detection, since the corresponding GFSM will heat up and transition to a molten state quickly and only in the area heated above the corresponding threshold temperature. Meanwhile, the remaining areas, whose temperature does not reach the corresponding threshold values, will retain their original appearance as heat propagates in a direction parallel to the base surface due to the low thermal conductivity of the air contained within the GFSM structure.

[0135] In the course of extensive research, the authors of the present group of inventions unexpectedly found that the best combination of resistance to mechanical impacts and hiding power and maximum brightness coefficient with a minimum thickness of the GTPM layer can be achieved by using OEs for which at least one of the conditions (a)-(d) is met, illustrated with reference to the positions of Fig. 4:

[0136] (a) the distance L(OE) between at least part of the OE is comparable to the average thickness h cp (GTPM), the GTPM layer is preferably L(OE) ~ (0.1-10) h cp (GTPM), most preferably L(OE) (1-5) h cp (GTPM). In absolute values, L(OE) is preferably in the range from 50 to 1250 µm;

[0137] (b) effective height h эф (OE), at least part of the OE is 20-100% of the average thickness h cp (GTPM) layer of the GTPM, preferably is not less than 0.3 h cp(GTPM), most preferably not less than 0.7 h cp (GTPM). In absolute values ​​h эф (OE) is preferably in the range of 35 to 175 µm;

[0138] (in) h cp (GTPM) does not exceed 1000 μm, preferably does not exceed 500 μm, most preferably is in the range from 50 to 250 μm;

[0139] (d) the thickness of the base h(Osn) does not exceed 200 μm, preferably does not exceed 100 μm;

[0140] (d) the thickness of the protective layer h(3C) does not exceed 100 µm, preferably does not exceed 25 µm.

[0141] The preference for choosing certain parameters of the structural elements of the TI is due to the need to ensure both high strength characteristics and resistance of the HTPM to mechanical impacts, and the preservation of operational properties: high hiding power of the base with a layer of HTPM and a high brightness coefficient, speed and accuracy of TI operation, irreversibility and ensuring a long service life.

[0142] In cases where the base and / or protective layer contain multiple FEs and / or multiple FEs are located within the thermal fusible layer, the thickness of the thermal fusible layer is non-uniform. Therefore, within the framework of the claimed group of inventions, the average thickness of the thermal fusible layer is used. ср (GTPM), the definition of which is given in the section "Terms, Definitions, and Abbreviations." The calculation of this value takes into account the difference in the thickness of the GTPM when it is located in areas with protrusions and / or depressions, as well as when the EO is located within the GTPM.

[0143] The average thickness of the thermal fusible layer should preferably not exceed 1000 µm. In preferred embodiments of the invention, the average thermal fusible layer thickness is no more than 500 µm, most preferably ranging from 50 to 250 µm. This thermal fusible layer thickness, on the one hand, ensures high hiding power of the hot-melt layer and a high brightness factor, and on the other hand, enables the rapid and uniform heating of the entire thermal fusible layer and its conversion to a melt, irreversibly changing the appearance of the thermal fusible layer with minimal heat consumption. This increases the response speed of the thermal fusible layer and enables the detection of overheating events with minimal temperature increases above the thermal fusible layer melting point. Furthermore, the use of a thermal fusible layer with this thickness enables the recording of even short-term overheating events with minimal exposure time, which may occur, in particular, under short-term peak loads or during emergency operating conditions.The use of a layer of such thickness of the GTPN also eliminates the spreading of the GTPN when it melts on the surface of the test object, which can lead to fire, loss of electrical strength, jamming and other accidents.

[0144] During the experiments, the optimal ratio of the distance L(OE) and the average thickness h was established. cp (GTPM). It has been established that ensuring optimal strength characteristics along with maintaining the required operational properties of the TI is achievable with a distance between the OE lying in the range L(OE) ~ (0.1-10)41 С p(GTPM). The location of the OE at a greater distance from each other, i.e. when L(OE) > 10 • h cp(GTPM), will lead to the loss of the functional properties of the EO as stiffeners, since a large volume of the GTPM will be located between the EO, which is less protected from mechanical impacts due to the EO's strength characteristics. Furthermore, after the EO's activation and reduction in thickness, significant sagging of the protective layer may occur, forming irregularities, which will negatively affect the visual perception of the activated TI and lead to difficulties in interpreting the temperature monitoring results. The placement of the EO at a smaller distance from each other, i.e., when L(EO) < 0.1 h cp (GTPM), will require an increase in the thickness of the GTPM to cover the color of the base and the OE, or will lead to a loss of contrast of the color change when the TI is triggered.

[0145] Thus, in the most preferred embodiments of the invention, L(OE) is from 50 to 1250 μm.

[0146] The authors also experimentally established the relationship between the optimal effective height of the support elements h эф (OE) and medium thickness y ср (GTPM). It is shown that ensuring optimal strength characteristics along with maintaining the required performance properties of TI is achievable at a value of h эф (OE), lying in the interval йэф(ОE) ~ (0.2-1) h cp (GTPM). Experiments conducted on the production and testing of TI, in which the yeff(OE) is less than 0.2 h cp(GTPM), revealed a deterioration in their functional characteristics under mechanical stress, since the height of the protective element is insufficient to impart sufficient strength to the GTPM layer. Devices in which the height of the protective element exceeded the average thickness of the GTPM had the required strength characteristics, but lost the contrast of the color change upon activation of the TI, since the protective layer did not touch the melt of the GTPM, resting on the protective element and sagging between them, forming an uneven surface (Fig. 56), on which additional light interference occurs. In preferred embodiments of the invention h эф (OE) is not less than 0.3 h cp (GTPM), in the most preferred cases - not less than 0.7 h cp (GTPM). In particular, the yeff(OE) is in the range from 35 to 175 µm.

[0147] In OOTI the values ​​of the effective height h эф(EO) and distances L(EO) can be the same or different. This is because various methods can be used to impart the desired relief to the base or protective layer or to apply individual elements to them. For example, sandblasting can be used to create a surface microrelief with non-uniform EO. Laser processing or embossing can also be used to create a precise and uniform surface relief.

[0148] The EOs can also be represented by additional structural elements located on the front surface of the base and / or protective layer, for example, individual elements with varying distances and / or heights. When using, for example, stripes, grooves, cells, mesh, etc., these parameters can be identical.

[0149] Individual EOs located within the gas turbine module may have a uniform, specified, or random size distribution. When using EOs with different values ​​of L(EO) and h эф (OE), it is preferable that at least a portion, for example more than 50% of the values ​​of L(OE) and h эф (OE) was within the corresponding ranges specified above. The average values ​​of these parameters can be used to assess the fulfillment of the conditions described above.

[0150] In preferred embodiments, the TI of the claimed group of inventions has a base thickness of no more than 200 µm, preferably no more than 100 µm. This ensures tight adhesion of the TI to surfaces with complex geometries, including conductive elements of electrical equipment. Using a base of this thickness also allows for rapid heating of the TGPM during short-term overheating, completely converting it to a molten state, and ensuring the necessary heat transfer during air cooling of operating devices. This allows for the detection of short-term emergency overheating caused by starting currents or short-circuit currents, excessive starting loads on motors, cold running of the electrolyzer, switching, or other processes.

[0151] In preferred embodiments of the claimed group of inventions, a protective layer is used, the thickness of which is no more than 100 μm, in the most preferred embodiments, no more than 25 μm, which ensures its high transparency for accurate and reliable identification of activated devices and, at the same time, sufficient strength, elasticity and flexibility.

[0152] A thermocouple that satisfies at least one of the conditions (a)-(d) described above has a small overall thickness, enabling accurate detection of short-term and localized surface overheating. Moreover, when a flexible base is used, the thermocouple's flexibility is maintained, ensuring its tight adhesion to complex surfaces and eliminating the risk of cracking or delamination of the heat-sensitive material from the base under any possible condition.

[0153] In various embodiments of the group of inventions, the pressure inside the gas-storage and heat-storage device may be lower than or equal to atmospheric pressure. Preferably, the pressure inside the gas-storage and heat-storage device is less than 53.2 kPa (400 mmHg), preferably less than 26.7 kPa (200 mmHg). In such gas-storage and heat-storage devices, when the threshold temperature is exceeded, an "air bubble" does not form due to the escape of the gas phase from the gas-storage and heat-storage device. Furthermore, the response speed of the heat-storage device is increased due to the atmospheric pressure on the protective layer, which is partially transferred to the gas-storage and heat-storage device during its melting. In this case, the protective layer function is particularly important, since the protective layer prevents the destruction of the gas-storage and heat-storage device under the influence of atmospheric pressure throughout the entire service life of the heat-storage device and allows for an extension of this service life, preferably by several years.

[0154] To maintain the pressure inside the gas-insulated layer below atmospheric pressure, the gas-insulated layer must be hermetically sealed from the environment by a protective layer. This will also protect the gas-insulated layer from adverse external factors, such as atmospheric moisture, splashes and vapors of aggressive liquids, industrial pollutants, etc. In this case, it is preferable to connect the base to the protective layer by welding.

[0155] If the pressure inside the gas-thermal medium is equal to atmospheric pressure and the gas-thermal medium layer is hermetically sealed with a transparent protective layer, the released gas, rising above the molten gas-thermal medium layer, will cause an "air bubble" to form under the protective layer. Since this occurs during heating, the volume of the resulting "air bubble" increases due to the thermal expansion of the gas. Part of the gas-thermal medium may adhere to the inner surface of the protective layer and rise with it. As a result, the portion of the gas-thermal medium adhered to the protective layer will be isolated from the heated surface by an air gap, leading to incorrect overheating detection if the thermal detector does not fully activate.

[0156] As the thermocouple cools further, the volume of the gaseous medium decreases, and the size of the "air bubble" beneath the protective layer decreases. This causes the protective layer to flex, causing cracks and folds to form, preventing reliable visual detection of overheating. These processes also explain the need to use elastic materials in thermocouple manufacturing to maintain its integrity during operation over a wide temperature range.

[0157] Using reduced pressure inside the gas-steel-and-metal (GSM) with a hermetically sealed protective coating allows for the thermal expansion of the gas to be compensated for. As a result, when the GSM threshold temperature is exceeded, an "air bubble" under the protective layer does not form, significantly reducing the likelihood of delamination and incomplete melting of the GSM and, consequently, unreliable overheating detection using thermal imaging.

[0158] At reduced gas pressure in the gas-filled thermocouple (GTPF), it will be subject to constant pressure from the protective layer caused by atmospheric air pressure. Given the fragility of the GTPF, a device without a protective element (PE) in this case may not operate correctly due to the pressure-dependent melting point of the GTPF. Without a protective element, the GTPF's base material may gradually change its transparency (degrade over time) due to recrystallization and the destruction of the original gas-filled structure at temperatures below the threshold, leading to unreliable operation of the thermocouple. Using a protective element (PE) in conjunction with the GTPF eliminates such potential for incorrect operation of the thermocouple.

[0159] At least one active GTPM is selected in such a way that upon reaching the corresponding threshold temperature in the range of no more than 5 °C, preferably no more than 2 °C, it melts with a visual transition from opaque to transparent within no more than 5 s, preferably no more than 2 s.

[0160] In preferred embodiments of the invention, at least one active substance of the HTPM has a molecular weight of less than 2 kDa (2000 amu). HTPMs with a low-molecular-weight HTPM base substance have a narrower response temperature range, which leads to increased accuracy in detecting threshold temperature exceedances. The use of low-molecular-weight substances as HTPM base substances for irreversible detection of threshold temperature exceedances is only possible with gas-filled materials. In the absence of a gas phase, multiple crystallization centers may form within the hot-melt material upon cooling of the HTPM with a low-molecular-weight hot-melt substance, leading to the formation of an opaque solid and a return to the HTPM's original form (response reversibility).

[0161] At least one solid organic substance of the GTPM contains a structural fragment C nH(2n+i), where n > 5. Preferably, at least one solid organic substance of the HTPM is selected from the group consisting of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 12; salts of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C n H(2n+i) with n > 5; amides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 5; anhydrides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 10; fatty aliphatic alcohols containing structural fragments C n H(2n+i) with n > 14; fatty aliphatic amines containing structural fragments C n H(2n+i) with n > 17; nitriles of fatty aliphatic acids containing structural fragments C nH(2n+i) with n>19. Preferably, such compounds are selected from the group consisting of palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearyl alcohol, cetyl alcohol, salts of saturated fatty carboxylic acids of rare earth metals, in particular lanthanum, yttrium, ytterbium, scandium. The use of compounds that contain one or more aliphatic hydrocarbon chains is preferable due to the fact that such organic substances have a crystalline packing in which the elongated structural fragments of linear hydrocarbons are oriented parallel to each other, which ensures the formation of mainly flat particles such as scales, plates or fibers (Kitaigorodskii A.I. Molecular Crystals: Monograph. Moscow: Nauka. 1971. 424 p. pp. 228-232).This crystalline packing results in anisotropy of the solid organic substance, resulting in material properties in a direction parallel to the surface of the base and protective coating differing from those in a direction perpendicular to the surface of the base and protective coating. The anisotropy of the properties of a hot-melt material affects its strength under bending and mechanical stress: applying stress in directions close to perpendicular to the surface of the base will not damage the material (Kitaigorodskii, A.I. Organic Crystal Chemistry: Monograph. Moscow: Publishing House of the Academy of Sciences of the USSR, 1955. 558 p. pp. 134-136).

[0162] The described shape and characteristics of the solid organic particles are preferred, but do not limit the claimed group of inventions. They can also be achieved using substituted aromatic and heteroaromatic compounds. In this case, the substituents can be either long hydrocarbon fragments, which further facilitate the formation of planar oriented particles, or heteroatomic substituents, which promote layered packing of molecules, in which bulky heteroatoms are located in the interlayer space (Bokiy, G.B. Crystal Chemistry: Monograph. 3rd revised and enlarged ed. Moscow: Nauka, 1971. 401 p. pp. 362-365).

[0163] However, it should be noted that the claimed group of inventions is not limited to the use of substances that include one or more aliphatic hydrocarbon chains with a structural fragment C nH(2n+i), where n > 5. In particular, the hot-melt material may include polyethylene, phenolic and phenol-acetylene resins, waxes, paraffins and other polymers that provide increased transparency of the material upon reaching the threshold temperature and possess the necessary properties.

[0164] In preferred embodiments of the invention, the volumetric gas content of at least one thermal conductivity material (TCM) is at least 10%, most preferably at least 50%. The gas is distributed predominantly uniformly within the TCM. Using at least one TCM with this volumetric gas content allows for a significant reduction in the thickness of the hot-melt material layer required to cover the base color, compared to the thickness of a non-gas-filled material layer required to provide the same coverage. This is achieved through multiple refraction of light at the gas-solid interface. Reducing the thickness of the hot-melt material layer positively impacts such characteristics as the response speed of the thermal conductivity material, irreversibility, and the ability to use low-molecular-weight substances, which in turn increases the reliability and accuracy of overheat detection.To prevent stratification of the gas-phase composite material during its heating due to thermal expansion of the gas phase, it is preferable that the pressure inside the gas-phase composite material be lower than atmospheric pressure, and that most of the pores filled with the gas phase be non-isolated, i.e. communicate with each other.

[0165] Using at least one gas-phase thermal imaging device with the specified volumetric gas content also extends the service life of the thermal imaging device and improves the reliability of overheating detection by preventing the aggregation of solid organic particles separated by the gas phase. Furthermore, the higher the gas volumetric gas content in the thermal imaging devices used, the higher the initial refractive index, the more pronounced the change in appearance due to a significant decrease in refractive index when the corresponding thermal imaging device threshold temperature is exceeded, and the more significant the redistribution of the solid or solid phases and the gas phase after thermal imaging device activation. This virtually eliminates the possibility of the thermal imaging device returning to its original state when the activated device is exposed to low temperatures or temperature fluctuations.In preferred embodiments, upon reaching the appropriate threshold temperature, the volume fraction of gas in the gas-fuel combustion chamber decreases, preferably by at least two times.

[0166] Due to the structure of the GTPM disclosed in the description of the invention, it is possible to record local overheating of the surface by changing the color of only that part of the GTPM that was heated above the corresponding threshold temperatures, and maintaining the original color of the sections of the GTPM that were not heated above the corresponding threshold temperature, during uneven heating.

[0167] In preferred embodiments of the invention, the base of the TI is made of a polymeric material containing halogen atoms, primarily polyvinyl chloride, most preferably cast polyvinyl chloride. The use of a halogen-containing polymer base enables the claimed TI to be used for visually recording temperature rises above at least one threshold value on the surfaces of conductive elements of electrical installations, as said base possesses dielectric properties and a dielectric strength of at least 5 kV / mm, and is also fire-resistant. Polymer materials containing halogen atoms in their structure exhibit some of the highest flexibility and elasticity among known polymers. The introduction of halogen atoms into the monomers used as the starting material for polymerization disrupts their symmetry and creates multiple chiral centers in the polymer.Polymerization or polycondensation of such monomers, both with each other and with other halogen-containing or halogen-free monomers, results in the formation of polymer chains with a large number of stereocenters. Regular polymers obtained from nonhalogenated monomers without chiral centers tend to form crystalline structures, which reduces their elasticity, while the large number of diastereomers formed during halogenation of monomers imparts stereochemical disorder to halogenated polymers, which prevents crystallization. Thus, halogenated polymeric materials exhibit high elasticity and flexibility due to the chemical structure characteristics resulting from the presence of halogen atoms in the polymer structure. Furthermore, halogenated materials exhibit good adhesion and low flammability, which further ensures the operational safety of the claimed device.

[0168] The protective layer protects the thermoelectric device from adverse external factors. Preferably, the transparent protective layer covering the thermoelectric device is made of elastic polymeric materials. This not only provides protection from environmental influences and prevents the melting of hot-melt compounds from spreading and flowing after the thermoelectric device is triggered, but also seals the device and maintains subatmospheric pressure within it until the thermoelectric device is heated. The elasticity of the protective layer also allows the thermoelectric device to be mounted on complex surfaces while maintaining its functional characteristics. The protective layer is preferably made of a polymeric material containing halogen atoms, preferably polyvinyl chloride, most preferably cast polyvinyl chloride. The protective layer can be attached to the substrate by welding, gluing, or other means.

[0169] In specific embodiments of the declared TI, an information element may be applied to the base and / or protective layer, which includes information for marking electrical equipment components or color coding of phases. Specifically, the information element applied to the front surface of the base may include an inscription containing color, alphabetic, numeric, or alphanumeric marking information. In one case, the information element on the base may contain information about the end-of-life date of the TI. The base may also be colored in accordance with established rules for marking electrical equipment components. The above features serve as TI properties for marking electrical equipment components.

[0170] To increase the visibility of both the device itself and the fact of its operation, and, as a consequence, further increase the safety of equipment operation, the base may have reflective or luminescent properties.

[0171] In special cases, the base may be colored using a substance that is capable of irreversibly changing color when heated.

[0172] The use of substances capable of irreversibly changing color when heated to a temperature below the threshold temperature of the primary or primary gas-processing equipment (GPC)—for example, by 10-30°C—in painting the base material alerts personnel to the risk of a future emergency, thereby ensuring its prevention with appropriate response from personnel responsible for the equipment. Thus, the activation of such a substance, without the primary GPC having a minimum threshold temperature, indicates overheating of the equipment, which has not reached the maximum permissible values ​​corresponding to the threshold temperatures of the primary GPC. Inspection is required to identify and correct any issues that could lead to a future emergency.Thus, the presence of a substance capable of irreversibly changing color when heated to a temperature below the threshold temperature of the main gas turbine power plant with a minimum threshold temperature, in particular by 10-30 °C, further increases the operational safety of both the declared device and the equipment as a whole.

[0173] The base, or a portion of it, can also be colored using a substance capable of reversibly changing color upon heating. For example, a layer of heat-sensitive paint with the aforementioned properties can be applied to the front surface.

[0174] The presence of a substance capable of reversibly changing color when heated allows personnel to be informed not only of past temperature threshold exceedances but also of overheating events during the inspection. Activation of such a temperature-sensitive element during an inspection indicates that the equipment is currently in emergency mode and may pose a potential hazard. Thus, the presence of a substance capable of reversibly changing color when heated further enhances the operational safety of both the device itself and the equipment as a whole.

[0175] According to the third variant of the group of inventions, the said technical result is achieved by manufacturing the TI using the first variant of the method, during the implementation of which:

[0176] - multiple OEs are formed on the surface of the entire base and / or protective layer or on individual sections of the surface of the base and / or protective layer;

[0177] - one or more layers of at least one suspension of at least one solid substance in a liquid phase, the boiling point of which is below 180 °C, are applied to the sections of the base and / or protective layer containing the OE, in such a way that at least part of the formed GTPM is located between the OE, wherein the proportion of the liquid phase is at least 50 mass %, and the solubility of the solid substance in the liquid phase does not exceed 100 g / kg;

[0178] - remove the liquid phase from the applied layers of suspension to form a gas-temperature-resistant composite;

[0179] - The base and protective layer are joined and secured by gluing or welding. This method comprises the steps necessary to produce a thermal indicator (TI) containing at least one solid (active) substance. This is achieved by using dilute suspensions of at least one active substance in the liquid phase with a liquid phase content of at least 50% by weight. Applying such suspensions results in uniform distribution of the active substance over the surface of the TI base and the formation of cavities filled with a liquid phase, such as an organic solvent, and, after its removal (e.g., by evaporation), filled with a gas phase. During the formation of the TI from the applied suspension layers, the active substance slowly settles, resulting in high hiding power due to the arrangement of the particles predominantly parallel to the surface plane of the temperature indicator.Liquid phase removal can occur spontaneously upon drying at room temperature and atmospheric pressure. Alternatively, liquid phase removal can be achieved by forced removal under reduced pressure and / or elevated temperature, or by any other means.

[0180] The use of a liquid phase with a solubility of at least one solid no greater than 100 g / kg is essential, as higher solubility will result in the formation of a transparent film of solid organic matter on the surface of the gas-phase coating material after removal of the liquid phase. High solubility can lead to smoothing of the outer surface of the solid organic matter in the gas-phase coating material and a decrease in the surface area of ​​the OE. As a result, the number of gas-solid interfaces will be reduced, and the hiding power (brightness) of the gas-phase coating material will be reduced.

[0181] The first two stages of the claimed method ensure the resistance of the TI to mechanical influences due to the fact that at least part of the GTPM is located between the OE.

[0182] In various embodiments of the method, the formation of multiple protective elements on the base and / or protective layer can be accomplished using mechanical, thermal, or combined methods. These methods include embossing, engraving, molding, and sandblasting. The choice of method, taking into account its specific features, is based on a number of parameters, including the base and / or protective layer material, its thickness, the composition and thickness of the PTFE, and the dimensions and homogeneity of the required protective elements.

[0183] In the second stage of the method, a suspension of at least one solid in a liquid phase, which additionally contains multiple thermal indicators, can be used. In this case, the thermal indicator, in addition to the supporting elements formed in the base material and / or protective layer, will contain the thermal indicators within the thermal indicator layer. The presence of the thermal indicators within the thermal indicator layer itself will further enhance the technical result of the claimed group of inventions by providing a greater number of thermal indicators and increasing the strength and wear resistance of the thermal indicator layer.

[0184] In preferred embodiments, this method for producing a TI may include additional processing of the OE to obtain a developed at least part of the OE surface, in particular by etching the OE.

[0185] In the fourth invention of the group, the said technical result is achieved through a method for manufacturing a temperature indicator (TI), during the implementation of which:

[0186] - a material containing multiple OEs is applied to some areas of the base and / or protective layer;

[0187] - one or more layers of at least one suspension of at least one solid substance in a liquid phase, the boiling point of which is below 180 °C, are applied to the areas of the base and / or protective layer containing the OE, wherein the proportion of the liquid phase is at least 50 mass %, and the solubility of the solid substance in the liquid phase does not exceed 100 g / kg;

[0188] - remove the liquid phase from the applied layers of suspension to form a GTPM; - connect the base and the protective layer and fasten them by gluing or welding.

[0189] In the fifth invention of the group, the said technical result is achieved through a method for manufacturing a temperature indicator (TI), during the implementation of which:

[0190] - a material containing multiple OEs is applied to some areas of the base and / or protective layer;

[0191] - one or more layers of at least one suspension of at least one solid substance in a liquid phase, the boiling point of which is below 180 °C, are applied to the areas of the base and / or protective layer containing the OE, wherein the proportion of the liquid phase is at least 50 mass %, and the solubility of the solid substance in the liquid phase does not exceed 100 g / kg;

[0192] - remove the liquid phase from the applied layers of suspension to form a gas-temperature-resistant composite;

[0193] - connect the base and the protective layer and fasten them by gluing or welding.

[0194] At any stage of the disclosed methods, sub-atmospheric pressure can be used, which further enhances the technical result of the claimed group of inventions for the reasons stated above in the description of the invention.

[0195] These methods also include steps necessary to obtain a structure of the HTPM containing at least one solid active ingredient. Both methods produce a HTPM containing a protective element, but in the fourth invention, the protective element is introduced into the HTPM by adding it to a suspension of at least one solid active ingredient in the liquid phase, while in the fifth invention, the protective element is pre-applied to the base and / or protective layer.

[0196] The sixth invention in this group achieves the stated technical result through a method for testing the previously described testing devices. In implementing the claimed method, in particular:

[0197] - form a representative sample of TI in a production batch of TI;

[0198] - for each TI sample, the numerical value of the brightness coefficient of the GTPM layer (TI) is determined;

[0199] - each TI of the sample is subjected to an external influence: (1) it is placed in an autoclave and maintained at a given excess pressure for a given period of time, or (2) each TI of the sample is secured to a solid surface, and a given compressive load of a given value is applied to the TI along the normal to the selected area of ​​the CGPM layer for a given period of time; - the numerical value of the luminance coefficient of the CGPM layer is determined again for each TI of the sample; the initial and re-determined numerical values ​​of the luminance coefficient are compared for each TI, and the quality of the TI is determined based on compliance with the established criteria.

[0200] The use of temperature indicators tested in this manner is advantageous for achieving the stated technical result. This method provides a clearly defined and regulated test of the temperature indicators, characterized in both the first and second inventions of the claimed group of inventions, for resistance to mechanical stress.

[0201] The results of comparisons of numerical luminance factor values ​​can be presented as either absolute or relative values, expressed as percentages or fractions. A measuring instrument is considered to have passed the test if its characteristics are within the range of values ​​specified by the manufacturer or specified for a given type of measuring instrument during its manufacture. When testing measuring instruments with different luminance factor differences, the numerical values ​​of the luminance factor differences for which the test is considered passed may differ for each luminance factor. Preferably, a luminance factor decrease of no more than 10% relative to the initial value is permitted. During additional testing for accuracy and response speed, a decrease in the accuracy of registering threshold temperature exceedances is permitted by no more than 0.5°C, and the response speed should preferably be no more than 5 s.

[0202] The numerical values ​​of excess pressure, compressive load, and exposure time are selected based on the characteristics of the temperature indicator (GTPM, base and protective layer materials, linear dimensions, etc.), as well as the intended operating conditions. In specific cases, the excess pressure is at least 1013 kPa (10 atm), and the exposure time is at least 10 minutes, and / or the compressive load is at least 20 kPa, and the exposure time is at least 1 minute.

[0203] Brief description of the drawings

[0204] Fig. 1 shows a schematic representation of a gas turbine engine with particles of solid organic matter and their conglomerates before (a) and after (b) exceeding the threshold temperature of a given gas turbine engine.

[0205] Fig. 2 shows a schematic representation of a gas-turbine-driven plant with particles of solid organic matter and their conglomerates with support elements (SE) located inside the gas-turbine-driven plant (a) and with SE made in the base material (b), between which at least part of the gas-turbine-driven plant is located.

[0206] Fig. 3 shows embodiments of the OE located on the base: (a) - the OE are made from the base material, are multiple protrusions uniformly distributed on the surface of the base and have a developed surface; (b) OE attached to the base.

[0207] Fig. 4 shows a schematic representation of the layered structure of the TI according to the first embodiment of the group of inventions in the field of one GTPM. A device embodiment in which (a) the base or (b) the protective layer includes non-uniform EOs formed in the material of the base (a) or the protective layer (b). Fig. 4c shows the layered structure of the temperature indicator according to the second embodiment of the group of inventions in the field of one TM. A device embodiment in which multiple EOs of irregular shape with a narrow size distribution are located inside the TM.

[0208] Fig. 5 schematically depicts the structure of the TI layers of the first invention of the group in the region of one GTPM before (a, c, d) actuation and after (b, d, e) actuation. Device variants in which the base includes uniform EOs made in the base material: (a, b) - h эф (OE) exceeds the average thickness of the layer of heat-sensitive material h cp (GTPM), a - before operation, b - after operation; (c, d) - h эф(OE) is less than 20% of the average thickness of the layer of heat-sensitive material h cp (GTPM), b - before operation, g - after operation; (d, e) - h эф (OE) is 20-100% of the average thickness of the layer of heat-sensitive material h cp (GTPM), d - before operation, e - after operation.

[0209] Fig. 6 shows the external appearance of the TI during local overheating: the initial (6a) appearance of the TI and the appearance of a partially activated (66) TI after spot heating of the surface of the test object above the threshold temperature of the GTPM with a change in the transparency of only that area of ​​the GTPM that was subjected to heating above the threshold temperature, while maintaining the original external appearance of the rest of the TI.

[0210] Fig. 7 shows the external appearance of the TI in the area of ​​one GTPM, the base of which in the area of ​​the GTPM is painted black and contains uniformly distributed cone-shaped EOs, and in the area free from the GTPM, it is painted for marking the phases (in this case, green) and contains information including the threshold temperature value of the given GTPM: the initial (7a) appearance of the TI, the appearance of the triggered (7b) TI after exceeding the threshold temperature of the GTPM, the appearance of the triggered (7c) TI after cooling to the ambient temperature and maintaining at this temperature for 1 year or more. Fig. 8 shows the external appearance of the TI in the area of ​​two pairwise alternating GTPM, the base of which includes EOs made in the form of longitudinally arranged strips.The base in the area of ​​the GTPM is painted black, and in areas free from the GTPM, a reversible heat-sensitive material is applied (in this case, it is green in its initial state) and information is applied, including the threshold temperature values ​​of the corresponding GTPM: the initial view (8a) of the TI, the view of a partially triggered (8b) TI after exceeding the threshold temperature of the first GTPM, the view of a completely triggered (8c) TI after exceeding the threshold temperature of the second GTPM and the threshold temperature of the reversible heat-sensitive material, the view of a completely triggered (8d) TI after cooling below the threshold temperature of the first GTPM.

[0211] Detailed description of the drawings

[0212] Fig. 1 shows a schematic representation of a section of the GTPM 2 with an average layer thickness Lgtpm, including particles 1 of solid organic matter and their conglomerates and gas phase 3, in the initial state (1a) and a schematic representation of a section of the GTPM 2 after exceeding its threshold temperature, in which melting of the particles of solid organic matter and the release of the gas phase from the volume of the GTPM to the surface occurred with a decrease in the average layer thickness to the value Lgtpm, where Lgtpm is less than Lgtpm, preferably at least two times.

[0213] Fig. 2 shows a schematic representation of a section of the gas-phase thermal power plant (GPP) 2, including particles 1 of solid organic matter and their conglomerates, and a gas phase 3, in the volume of which the EO 4 (2a) are distributed, or at least a part of the GPP is located between the support elements 4 made in the base material (26). Fig. 2a shows a special case in which the support elements 4 have a shape close to spherical, characterized by the effective height of the support element b Э f(OE), distributed within the GTPM predominantly uniformly and spaced L(OE) apart. Fig. 2b shows a special case in which the support elements 4, made in the base material 5, have a pyramidal shape and are distributed uniformly and regularly on the base. Fig. 2b also shows the distance between the support elements L(OE) and the effective height of the support element b Э f(OE).

[0214] Fig. 3 shows variants of support elements 4 made or located on base 5. Fig. 3a shows a special case in which support elements 4 are made from base material and are projections of the same size with the effective height of the support element b Э f(OE), located on the base uniformly at a distance L(OE) and having a developed surface. Fig. 3a also shows the thickness of the base. Fig. 3b shows a special case in which the supporting elements 4, characterized by the effective height of the supporting element b Э f(OE), OE are fixed on the base and are made of a material different from the base material, have an irregular shape and are located on the base unevenly at a distance L(OE), which should be understood as the average value for the volume of the GTPM or an element of the volume (see the section “Terms, definitions and abbreviations used in the description of the present group of inventions”).

[0215] In Fig. 4a the layered structure of the temperature indicator according to the first variant of the group of inventions in the field of one GTPM 2 is shown, the plane of the temperature indicator in section A-A. The temperature indicator includes a base 5, at least one GTPM 2, in the initial state opaque for at least part of the visible light, a protective layer 6 covering the GTPM 2 and at least a part of the base 5 free from the GTPM. A variant of the device in which the base 5 includes non-uniform EOs 4, made in the material of the base 5, between which at least a part of the GTPM 2 is located. In Fig. (4a) the following are shown: the plane of the surface of the temperature indicator B-B, the Main Area of ​​the Temperature Indicator (MATI) in a normal section is limited by perpendiculars dropped from the vertices of the extreme EOs onto the plane of the surface of the temperature indicator B-B, intersecting it at points Mo and Mi. The distance between support elements L(OE) is shown as the distance between the 4' vertices of adjacent OE. The effective height of the support element is Ь Эf(OE) is shown as the length of the segment lying on the perpendicular dropped from the top of OE 4' onto the plane B-B, and connecting the top of OE 4' with the point of intersection of this perpendicular with the segment Co-Ci, connecting the depressions adjacent to the top of OE. The thickness of the base 5 in this case is understood as an average value (see the section "Terms, definitions and abbreviations used in the description of the present group of inventions"). The thickness of the protective layer h is also shown 3C , at the site of its attachment to the base 5.

[0216] In Fig. 46 a normal section is presented showing the structure of the layers of the TI of the variant of the first invention of the group in the region of one GTPM 2. The TI includes a base 5, at least one GTPM 2, in the initial state opaque for at least part of the visible light, a protective layer 6 covering the GTPM 2 and at least a part of the base 1 free from the GTPM. In this variant, the protective layer 6 includes non-uniform convex-concave EOs 4, made in the material of the protective layer 6, between which at least a part of the GTPM 2 is located. The main area of ​​the temperature indicator (MATI) in the normal section is limited by perpendiculars dropped from the vertices of the extreme EOs onto the plane of the surface of the temperature indicator B-B, intersecting it at the points Mo and Mi. The distance between support elements L(SE) is shown as the distance between the 4' vertices of adjacent SE.The effective height of the support element BEf(OE) is shown as the length of the segment lying on the perpendicular dropped from the top of OE 4' onto the plane B-B, and connecting the top of OE 4' with the point of intersection of this perpendicular with the segment Co-Ci connecting the depressions adjacent to the top of OE. The thickness of the protective layer 6 in this case is understood as an average value (see the section "Terms, definitions and abbreviations used in the description of the present group of inventions").

[0217] Fig. 4c shows a normal section showing the structure of the layers of the TI of the second invention of the group in the region of one HTPM 2. The TI contains a base 5, at least one HTPM 2, in the initial state opaque for at least part of the visible light, a protective layer 6 covering the HTPM 2 and at least a part of the base 1 free from the HTPM. A variant of the device in which multiple irregularly shaped EOs 4 with a narrow size distribution are located inside the HTPM 2. The main area of ​​the temperature indicator (MATI) is limited by perpendiculars dropped from the vertices of the outer support elements onto the B-B plane and intersecting it at points Mo and Mi. The distance between the support elements L(ME) is shown as the distance between the vertices 4' of adjacent support elements facing the protective layer 6; the thickness of the BASE Ьосн ; the thickness of the protective layer h 3C ; Effective height of the support element Ь Эf(OE) is shown as the maximum length of a segment belonging to the OE section normal to the plane parallel to the B-B plane and containing the Co-Ci segment of maximum length for the given OE.

[0218] Fig. 5 shows the structure of the layers of the TI of the first invention of the group in the region of one HTSM 2 and two EOs 4 before (a) actuation and after (b) actuation of the TI. The thermal indicator includes a base 5, at least one HTSM 2, in the initial state opaque for at least part of the visible light, a protective layer 6 covering the HTSM 2 and at least a part of the base 5 free from the HTSM. A variant of the device in which the base 5 includes uniform EOs 4 made in the material of the base 5, between which at least a part of the HTSM 2 is located, wherein Leff(EO) exceeds the average thickness of the layer of heat-sensitive material L С p(GTPM). Exceeding b СCase (5a) is also considered for the case where the supporting elements essentially reach the top layer of the gas-filled medium. In this case, sufficient hiding power is not achieved, and upon activation of the TI, due to the release of the gas phase from the gas-filled medium volume, the thickness of the gas-filled medium layer decreases significantly. The protective layer, resting on the supporting elements and sagging between them, forming an uneven surface, does not touch the gas-filled medium, which leads to a loss of contrast and changes in the appearance of the TI upon activation. Figure 5a also shows the distance between the supporting elements L(OE).

[0219] Fig. 5 shows normal sections of the TI showing changes in the structure of the TI layers for the first invention of the group in the region of one HTPM 2 and several EOs 4 before (c) and after (d) the TI operation. The TI comprises a base 5, at least one HTPM 2, in the initial state opaque for at least part of the visible light, a protective layer 6 covering the HTPM 2 and at least a part of the base 5 free from the HTPM. A variant of the device in which the base 5 includes uniform EOs 4 made in the material of the base 5, between which at least a part of the HTPM 2 is located, wherein b Э f(OE) is less than 20% of the average thickness of the layer of heat-sensitive material Ь С p(GTPM). Fig. 5c shows the region of the GTPM that is subject to mechanical action (in particular, pressure in the transverse direction). The region of the GTPM, shaded in Fig. 5c, is not protected by support elements 4 from destruction under the influence of external influences due to the too small value of hэф (OE), therefore the gas-insulated layer will be less protected from mechanical impacts due to the strength characteristics of the OE. Fig. 5g shows that when the TI is triggered, the thickness of the gas-insulated layer significantly decreases due to the release of the gas phase from its volume; the protective layer in the triggered state touches the gas-insulated layer, and the supporting elements, due to the small b Э f(OE) lose their functionality as stiffeners (5g). Fig. 5c also shows the distance between the support elements L(OE).

[0220] Option when Ь Э f(OE) is 20-100% of the average thickness of the layer of heat-sensitive material Ь Сp(GTPM), is shown in Fig. 5 (d, e). The structure of the TI layers for the first invention of the group is shown in the region of one GTPM 2 and several uniform OEs 4, made in the material of the base 5, before (d) actuation and after (e) actuation of the TI. The TI contains a base 5, at least one GTPM 2, in the initial state opaque for at least part of the visible light, a protective layer 6 covering the GTPM 2 and at least a part of the base 5 free from the GTPM. When the TI is actuated, the thickness of the GTPM layer decreases significantly due to the release of the gas phase from the volume of the GTPM, the protective layer in the actuated state partially touches the GTPM and practically does not sag on the OE. Fig. 5d also shows the distance between the support elements L(OE).

[0221] Fig. 6 shows the external appearance of the TI for recording the excess of one temperature threshold value during local overheating: the initial appearance (6a) of the TI with one GTPM 2 located on the section of the base 1, and the appearance of the TI partially triggered after spot heating (66) of the surface of the test object above the threshold temperature value with a change in the transparency of only that area 7 of the GTPM that was subjected to heating above the threshold temperature of the GTPM. The remaining surface of the TI remains opaque.

[0222] Fig. 7 shows the external appearance of the TI in the region of one GTPM 2, the threshold temperature of which is 80 °C. The base 5 in the area of ​​the GTPM includes uniformly spaced support elements 4 made in the form of cones and is painted black, and in the area free from the GTPM, it is painted for marking the phases (in this case, in green): 7a - the initial appearance of the TI, 76 - a fully activated TI after exceeding the threshold temperature of GTPM 2, ensuring the development of the color of the base 5 under this GTPM and the visibility of the OE 4, 7v - a activated TI after cooling to room temperature and holding at this temperature for 1 year or more, in which GTPM 2 retained the transparency and visibility of the color of the base 5 under it and the visibility of the OE 4. On the front surface of the TI base in the area free from the GTPM, there is an inscription 8, including the numerical value of the threshold temperature of this GTPM.

[0223] Fig. 8 shows the appearance of the TI in the region of two pairwise alternating GTPM 2, the threshold temperature of which is 60 °C and 80 °C. The base 5 in the area of ​​the GTPM includes uniformly spaced support elements 4 made in the form of longitudinal stripes and is painted black, and in the areas free from the GTPM, a reversible heat-sensitive material 9 is applied (in this case, green) with a reversible color change temperature of 80 °C: 8a - the initial appearance of the TI, 8b - a partially triggered TI after exceeding the threshold temperature of the first GTPM (60 °C), 8c - a fully triggered TI after exceeding the threshold temperature of the second GTPM (80 °C) and the threshold temperature of the reversible heat-sensitive material 9, 8g - a triggered TI after cooling below the threshold temperature of the first GTPM, in which the visibility of the color of the base 1 under all GTPM 2 and the visibility of the EO 4 is preserved, and the color of the reversible heat-sensitive material 9 has returned to the original.On the front surface of the TI base in the area free from the GTPM, there are inscriptions 8, including the numerical values ​​of the threshold temperatures corresponding to the GTPM.

[0224] Implementation of a group of inventions

[0225] Selecting a base and protective layer

[0226] Both polymeric materials and inorganic substances can be used as a base for the 5 claimed TIs. When polymeric materials are used, the TIs acquire elasticity, resilience, and flexibility. When inorganic substances, such as ceramics, are used as a base, the TIs exhibit high strength and low flammability. Halogen-containing polymeric materials are predominantly used, but are not limited to, in particular chlorine-containing polymers, such as vinyl chloride copolymers, namely: copolymer C-15 (a copolymer of vinyl chloride and vinyl acetate), copolymer VHVD-40 (a copolymer of vinyl chloride and vinylidene chloride), polyvinyl chloride (PVC), cast PVC, polyvinylidene fluoride PVDF, fluoroplastic M-40, as well as polyesters with the addition of 6.5% hexabromocyclododecane or polyesters modified with 15% trichloroisopropyl phosphate.

[0227] When using a halogen-containing polymer base (5), the dielectric strength of the TI is preferably at least 5 kV / mm, which is preferred for use in the power industry. The back of the base can be coated with an adhesive, in which case the TI can be made in the form of a sticker. Suitable adhesives include acrylic or polystyrene adhesives, rubbers, and polyurethane adhesives with the required adhesion values. Preferably, the adhesion to stainless steel, measured using the FINAT TM1 method after 24 hours, is at least 10 N / 25 mm. The adhesive layer can be coated with a release agent, particularly a siliconized one, to protect the adhesive until the TI is installed.

[0228] The selection of the base material for device 5 is carried out to ensure secure attachment and tight adhesion of the TI to the equipment surface. When selecting the base material, its melting or decomposition temperature must also be taken into account, which must be higher than the operating temperature of the GTPM 2. Furthermore, the compressive strength of the base material 5 should preferably be higher than the compressive strength of the GTPM 2.

[0229] The thickness of the base 5 of the device is preferably no more than 200 µm, most preferably 100 µm. This thickness ensures the required high response speed of the GTPM 2. Using a base 5 of this thickness ensures rapid heating of the GTPM 2 layer during short-term overheating, and also ensures the necessary heat transfer from the monitored surface during air cooling of the operating devices without degrading their thermal performance. In preferred embodiments, the response speed of the TI is less than 5 s, preferably 2 s, when heated above the corresponding threshold temperature of the GTPM 2.

[0230] In the production of the declared TI, a protective layer 6 is used, which protects the GTPM 2 and the entire TI from environmental influences, humidity, UV radiation and mechanical damage, increases the service life of the TI, and prevents the heat-sensitive material from spreading over the surface of the test object or flowing off it during the phase transition.

[0231] The material of protective layer 6 is preferably selected from transparent elastic polymers, preferably from halogen-containing polymers, in particular from polyvinyl chloride, most preferably from cast polyvinyl chloride. Flexible elastic polymer films made of polyvinyl chloride, polyurethane, polyurea, and other polymers are preferably used as materials for protective layer 6.

[0232] By using an elastic material as the protective layer 6, not only the flexibility of the TI is achieved, but also its integrity is maintained during the melting of the thermally sensitive material 2, accompanied by the expansion of gas 3 and its release into the area between the heat-sensitive material and the protective layer 6. The elasticity of the latter allows layer 6 to deform without separation from the base 5. In the case of using non-elastic materials for the protective layer 6, there is a risk of its cracking when the TI is triggered, as well as a violation of the integrity of the protective layer and the insulation of the thermally sensitive material 2 when installing the TI on uneven, especially curved surfaces.

[0233] When selecting the material for protective layer 6, it is necessary to take into account its melting temperature and compressive strength, which must be higher than the corresponding parameters of GTPM 2.

[0234] The thickness of the protective layer 6 of the device is preferably no more than 100 µm, most preferably 25 µm, which will ensure the integrity of the device when the GTPM 2 is triggered and the flexibility of the device as a whole.

[0235] The base 5 and / or the protective layer 6 may have reflective or luminescent properties to increase the visibility of both the device itself and the fact of its operation to increase the visibility of the TI and improve the safety of operation of the equipment on which it is installed.

[0236] In a particular case, the base 5 and / or the protective layer 6 or a part thereof may be colored, in particular to perform the function of marking the phases of cables, installation wires, harnesses and other elements of electrical equipment, wherein the color of the base 5 is preferably selected in accordance with the current regulatory documents, for example, GOST 28763-90 (IEC 757-83), which establishes, in particular, color marking in the field of electrical engineering and is in effect on the filing date of this application. It should be taken into account that when painting the protective layer 6, at least its part located above the GTPM 2 must be transparent, at least for a part of the visible light. To increase the contrast of the color transition, the base 5 in the area of ​​at least one GTPM 2 can be painted, for example, black. In this case, in the initial state, the GTPM 2 is preferably white, thereby ensuring a visual transition from white to black upon activation of the TI.

[0237] Information 8 may also be applied to the surface of the base 5 and / or protective layer 6, including threshold temperature values, the expiration date of the TI and other data.

[0238] In order to create a TI when implementing the first invention of the group, in which the base 5 and / or the protective layer 6 includes multiple support elements 4, between which at least a portion of the GTPM 2 is located, a relief surface is formed on the front side of the base 5 and / or on the back side of the protective layer 6. The relief of the base 5 and / or the protective layer 6 can be imparted either at the time of production of the base / protective layer, for example, by molding or hot casting in a screen form, or during subsequent processing of the surface of the base / protective layer, for example, by embossing, engraving or sandblasting. Other methods that ensure the creation of a predetermined surface relief can also be used. In this case, the FE 4 are made from the material of the base 5 and / or the protective layer 6 and preferably represent multiple protrusions on the surface of the base 5 and / or the protective layer 6, between which at least a portion of the GTPM 2 will be located.Alternatively, recesses can be made in the base material and / or the protective layer, which will be at least partially filled with the GTPM 2.

[0239] In order to create a temperature indicator according to the second embodiment of the invention, in which multiple EE 4 are located inside the GTPM 2, support elements 4 are used, made of another material, the melting temperature of which is higher than the melting temperature of the GTPM 2, and the compressive strength of the EE 4 is higher than the compressive strength of the GTPM 2. In this embodiment of the invention, polymeric materials can be selected as materials for the EE 4, in particular, halogen-containing polymers, such as polyvinyl chloride and cast polyvinyl chloride, as well as glass, ceramics, metals, non-metals and products based on them, for example, meshes, fibers, microspheres, woven or non-woven materials having the above characteristics.

[0240] Absorbent materials, preferably fibrous, porous, or microporous, most preferably with a pore diameter of no more than 2 µm, can also be used to create the OE according to the second embodiment of the invention. In particular, the absorbent material for the OE can be selected without limitation from, among others, fibrous material, microcellulose, polysaccharides, silica gel, zeolites, metal oxides, and aerosil.

[0241] It is preferable that the material OE 4 has a refractive index comparable to the refractive index of at least one organic substance 1 included in the composition of the HTPM 2, to ensure the visibility of the base 5 after the actuation corresponding to the HTPM 2.

[0242] To ensure the hiding power of base 5 before the activation of the TI without a significant increase in the thickness of the GTPM 2, as well as to reveal the color of base 5 when the TI is activated, it is preferable that at least part of the OE 4 has a developed surface, the specific area of ​​which is not less than 0.2 m 2 / g. The volume content of the gas phase 3 between the OE 4 and the GTPM 2 should be no more than 30%, preferably no more than 10% of the volume of the GTPM 2. The formation of a developed surface of the OE 4 can be carried out by etching or any other method that ensures the required result.

[0243] Support elements 4 located within the GTPM 2 may, in certain cases, contact the base 5 and / or protective layer 6 or be attached to the base 5 and / or protective layer 6 by welding, gluing, or other methods that ensure secure attachment. They may be constructed in the form of a mesh, regular or arbitrary volumetric figures, a matrix, or any other design.

[0244] The shape, size and mutual arrangement of the 4 EOs in the first and second inventions of the group may be either regular and / or uniform, or uneven and / or irregular, depending on the chosen method of their manufacture and the task solved using the TI.

[0245] Regardless of the nature and method of creating the 4 EOs, their dimensions and mutual arrangement in preferred embodiments will satisfy at least one of the conditions (a)-(d):

[0246] (a) the distance L(OE) between at least part of the OE is comparable to the average thickness h cp (GTPM), the GTPM layer is preferably L(OE) ~ (0.1-10) h cp (GTPM), most preferably L(OE) (1-5) h cp (GTPM). In absolute values, L(OE) is preferably in the range from 50 to 1250 µm;

[0247] (b) effective height h эф (OE), at least part of the OE is 20-100% of the average thickness h cp(GTPM) layer of the GTPM, preferably is not less than 0.3 h cp (GTPM), most preferably not less than 0.7 h cp (GTPM). In absolute values ​​h эф (OE) is preferably in the range of 35 to 175 µm;

[0248] (in) h cp (GTPN) does not exceed 1000 μm, preferably does not exceed 500 μm, most preferably is in the range from 50 to 250 μm; (g) the thickness of the base d(Osn) does not exceed 200 μm, preferably does not exceed 100 μm;

[0249] (d) the thickness of the protective layer h(3C) does not exceed 100 µm, preferably does not exceed 25 µm.

[0250] Preparation of heat-sensitive material (HSM)

[0251] In the claimed group of inventions, at least one GTPM 2 includes a solid organic substance and is designed with the possibility of an irreversible change in transparency upon reaching the corresponding threshold temperature.

[0252] Preferably, at least one solid organic substance 1 HTPM 2 has a molecular weight of less than 2 kDa (2000 amu), contains a structural fragment C п H(2n+1), where n > 5 and preferably without limitation is selected from the group consisting of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 12; salts of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C n H(2n+i) with n > 5; amides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 5; anhydrides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 10; fatty aliphatic alcohols containing structural fragments C n H(2n+i) with n > 14; fatty aliphatic amines containing structural fragments C nH(2n+i) with n > 17; nitriles of fatty aliphatic acids containing structural fragments C n H(2n+i) with n>19; and it is preferably selected from the group consisting of palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearic alcohol, cetyl alcohol, polyethylene, wax, paraffin, salts of saturated fatty carboxylic acids of rare earth metals, in particular lanthanum, yttrium, ytterbium, scandium or mixtures thereof with a melting point differing from the threshold temperature by no more than 5 °C.

[0253] In particular embodiments of the invention, the main substance 1 of the GTPM 2 or a mixture of such substances, causing a change in the transparency of the heat-sensitive material when heated above a threshold temperature, is, without limitation, selected from at least one of the group consisting of yttrium caproate, yttrium behenate, yttrium undecanoate, yttrium laurate, yttrium tridecanelaurate, yttrium tridecanepentadecanate, yttrium tridecanoate, yttrium pentadecanoate, yttrium palmitate, ytterbium caprylate, lanthanum palmitate, lanthanum nonadecynate, lanthanum caproate, erbium undecanate, zinc nonadecanoate, zinc palmitate, zinc caproate, zinc myristate, zinc stearate, cadmium laurate, cadmium laurinmyristinate, caprate lead, lead stearate, lead laurate, lead laurin myristate, copper stearate, calcium stearate, lithium stearate, stearic acid, lauric acid, docosanoic acid, eicosanoic acid, crotonic acid, arachidic acid, myristic acid, palmitic acid,Adipic acid, octanoic acid, capric acid, tricosanic acid, tetratriacontanoic acid, 2,3-dimethylnonanoic acid, brassidic acid, 2-methyl-2-dodecenoic acid, eleostearic acid, behenolic acid, behenic acid, oleamide, stearamide, lauramide, erucylamide, capric amide, myristic amide, caprylic amide, palmitic anilide, salicylic anilide, beta-naphthylamide caproic acid, enanthic acid phenylhydrazide, hexylamide, octacosylamide, N-methylheptacosylamide, salicylamide, hexadecanol, ecucamide, 1-docosonol, trilaurin, tricose amine, dioctadecylamine, H>4-dimethyloctylamine, dioctylphosphinic acid, tritriacontane, tetracosane, stearyl alcohol, cetyl alcohol, stearic chloride, palmitic anhydride, stearic and acetic anhydride, lauric anhydride and mixtures thereof.,

[0254] In preferred embodiments of the inventions of this group, the volumetric content of gas 3 within at least one thermally sensitive material 2 is at least 10%, most preferably at least 50%, and the gas phase is uniformly distributed within the thermally sensitive material. The use of at least one thermally sensitive material 2 with the specified gas content allows for a significant reduction in the thickness of the thermally sensitive material 2 layer required to cover the base color, compared to the thickness of a layer of material containing no gas phase required to provide the same hiding power. This is achieved through multiple refraction of light at the gas-solid interface. Reducing the thickness of the heat-sensitive material layer positively impacts such characteristics as response speed, irreversibility, and the ability to use low-molecular-weight substances, which in turn increases the reliability and accuracy of overheating detection.

[0255] Preferably, upon reaching the corresponding threshold temperature, the volume fraction of gas phase 3 within the gas-phase medium 2 decreases by at least a factor of two. This will ensure that the change in transparency of the gas-phase medium 2 is irreversible when the corresponding threshold temperature is exceeded.

[0256] The use of at least one GTPM 2 with the specified volumetric content of gas 3 also allows for an increase in the service life of the TI and an increase in the reliability of overheating determination due to the impossibility of aggregation of solid organic matter 1 through the gas phase 3. Also, the greater the proportion of gas phase 3 in the GTPM 2 used, the higher the initial refractive index, the more contrasting the change in appearance due to a strong decrease in the refractive index when the corresponding threshold temperature is exceeded, and the more significant the separation of gaseous and non-gaseous media after the TI is triggered, eliminating the possibility of the material returning to its original gas-filled state when the triggered TI is kept at low temperatures and with temperature fluctuations.

[0257] The main substance 1 GTPM 2 or their mixture is selected in such a way that upon reaching the corresponding threshold temperature in the range of no more than 5 °C, preferably no more than 2 °C, it melts with a visual transition of “opaque-transparent” within no more than 5 s, preferably no more than 2 s.

[0258] In various embodiments of the inventions of the group, the main substance 1 of the GTPM 2 or a mixture thereof is selected in such a way that the threshold temperatures can be in the range from 50 to 210 °C. In this case, the numerical values ​​of the threshold temperature of the GTPM 2 can be selected, in particular, 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.

[0259] To produce at least one GTPM 2, the solid organic substance is ground in a ball mill to a particle size of 2-3 µm. A liquid phase consisting of water, an organic solvent, or a mixture thereof, with a boiling point below 180°C, is sequentially added, and the resulting suspension is mixed. Preferably, the mixture is periodically dispersed with air access until a constant mixture density is reached. The liquid phase is preferably water or an organic solvent in which the solubility of the solid organic substance of the GTPM does not exceed 100 g / kg.

[0260] In preferred embodiments of the inventions of the group, the liquid phase is added in an amount of at least 50 wt.%, most preferably from 50 wt.% to 90 wt.%.

[0261] The difference in density between the liquid phase and the solid organic matter is preferably less than 0.2 g / cm 3For this purpose, the liquid phase can be selected without limitation from the group consisting of isopropanol, water, methanol, 1-propanol, isobutanol, ethylene glycol monomethyl ether, 1-butanol, acetonitrile, acetic acid, hexane, heptane, octane, nonane, 1,1,1-trifluoroethanol, 1, 1,1, 3,3,3-hexafluoroisopropanol, N,T4-dimethylformamide, toluene, xylene, ethanol, butyl acetate, acetone and mixtures thereof. This method ensures the production of at least one GTPM 2, including a solid organic substance 1, preferably presented in the form of particles oriented predominantly parallel to the surface of the base with uniformly distributed voids filled with a gas phase 3. Depending on the nature of the solid organic substance 1, the type of the resulting particles can predominantly be grains, crystals, fibers, flakes or their conglomerates.

[0262] To produce the TI in the second invention of the group, in which multiple 4 supporting elements are located inside the 2 supporting elements, these supporting elements can be added to a suspension of solid organic matter in the liquid phase, followed by mixing until a uniform distribution of the 4 supporting elements in the suspension is achieved.

[0263] At least one HTPM 2 in its initial state is opaque to at least a portion of visible light. In preferred embodiments of the invention, upon heating above the corresponding threshold temperature, an irreversible change in the structure of the HTPM 4 occurs, accompanied by melting of the solid organic substance 1, a decrease in the volume content of the gas phase 3, preferably by a factor of 2 or more, and an increase in the transparency of the HTPM 2 with the development of the color of the base 5. Due to the release of gas 3 during melting of the base substance, the structure of the HTPM 2 is destroyed and the gas 3 and molten phases are separated, with an increase in transparency. Upon subsequent cooling of the TI below the threshold temperature of the HTPM, the recombination of these phases to obtain a material structure close to the original one is impossible.Therefore, upon subsequent cooling to 20 °C and holding at this temperature for at least one month, preferably one year or more, the transparency of GTPM 2 does not return to its original values.

[0264] In particular cases, at least one HTPM 2 additionally contains a polymer binder that is transparent to at least part of the visible light, the phase transition temperature of which is higher than the phase transition temperature of the solid organic substance 1. In this case, the crushed solid organic substance 1 is suspended in a solution of a binder that is transparent to at least part of the visible light in the liquid phase. In preferred embodiments of the invention, to ensure the glazing effect of the particles of the solid organic substance 1, the binder is present in the resulting HTPM 2 in an amount of 1-30 wt.%.

[0265] In particular cases, the transparent polymer binder can be selected without limitation 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, polyisobutylene, polyvinyl acetate, polymethacrylate, ethyl cellulose, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polycaprolactone, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resins, polyvinylidene fluoride, polyester, polyester resins, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, nitrocellulose, carboxymethyl cellulose, gelatin, agar-agar, casein, gum arabic, polyvinyl alcohol, polyethylene oxide and mixtures thereof.

[0266] General technology for manufacturing TI

[0267] To implement the method, which is the third invention of the group, a base 5 and / or protective layer 6 are used, on the surface of which multiple OEs 4 are formed. To implement the method, which is the fourth invention of the group, a smooth base 5 and / or protective layer 6, as well as a base 5 and / or protective layer 6 having a relief surface, can be used. To implement the method, which is the fifth invention of the group, a base 5 and / or protective layer 6 with a material applied containing multiple OEs 4 is used.

[0268] In some cases, information about the recorded threshold temperatures 8 is applied to the front surface of the base 5 or the front / back surface of the protective layer 6. In certain cases, in addition to the threshold temperatures, information about the end-of-life date of the measuring instrument is also applied. In one embodiment, a design or ink intended for marking the phases or components of electrical equipment, containing graphical, numerical, or textual information, may be applied to these surfaces. A ink providing reflective or luminescent properties may also be applied to these surfaces.

[0269] In the case of using a smooth protective layer 6, in general, the method for applying the GTPM 2 may include the stages of applying one or more layers of a suspension of a solid organic substance 1 in the liquid phase of each GTPM 2 to individual sections of the opaque base 5, removing the liquid phase from the applied layers of the suspension, and also coating the front surface of the workpiece with a transparent protective layer 6. In the case of using a protective layer 6 that includes multiple EOs 4, the application of a suspension of a solid organic substance 1 in the liquid phase occurs on the protective layer 6 similar to the application to the base 5, followed by fastening the base 5 to the protective layer 6 with the applied GTPM 2. Below, the variant with a smooth protective layer 6 will be considered.

[0270] The adhesion of the protective layer 6 and the base 5 can be achieved by cold or hot lamination at a temperature below the threshold temperature of the GTPM 2, by welding, gluing or other methods.

[0271] In some embodiments of the invention, a gap may be provided between the protective layer 5 and the base 6. Alternatively, micro-holes may be provided in the protective layer 6 to allow gas to escape from the device after exceeding the detectable temperature.

[0272] In those embodiments of the inventions where reduced pressure of the gas phase is used inside the GTPM 2, the transparent protective layer must ensure hermetic isolation of the GTPM 2 from the environment.

[0273] In order to obtain at least one GTPM 2, including a solid organic substance 1, which is designed with the possibility of an irreversible change in transparency upon reaching the corresponding threshold temperature, the following techniques can be used, in particular:

[0274] - at least one of the stages: applying a suspension of a solid organic substance in the liquid phase, removing the liquid phase from the applied layers of suspension, covering the front surface of the workpiece with a transparent protective layer, which are carried out at a pressure below atmospheric pressure;

[0275] - at least 3 cycles of applying layers of a suspension of a solid organic substance in a liquid phase and removing the liquid phase from the applied layers of this suspension are carried out, wherein the application of a suspension of a solid organic substance in a liquid phase is carried out by a method selected from the group consisting of screen printing, flexographic printing, pad printing, silk-screen printing, with the production of a GTPM in which the solid organic substance is preferably made in the form of particles oriented predominantly parallel to the plane of the surface of the base.

[0276] Removal of the liquid phase from the applied layers of suspension of solid organic matter in the liquid phase or from each layer separately can be carried out both at sub-atmospheric pressure and at atmospheric pressure.

[0277] Subatmospheric pressure, in specific cases of TI fabrication, can be used either immediately after applying each individual layer of solid organic matter suspension in the liquid phase or during the drying stage, i.e., removing the liquid phase from the required number of applied layers of solid organic matter suspension in the liquid phase. In this case, a sharp increase in the volume of the liquid phase within the material occurs, forming large, uninsulated cavities within the GTPM 2.

[0278] The use of reduced pressure when joining the protective layer 6 to the base 5, for example by gluing or welding, in preferred embodiments of the invention makes it possible to create a pressure inside the GTPM 2 below atmospheric pressure, preferably less than 53.2 kPa (400 mmHg), most preferably less than 26.6 kPa (200 mmHg). This makes it possible to avoid the formation of an "air bubble" under the protective layer 6 when the GTPM 2 is activated and the gas phase 3 and non-gaseous media 1 are separated.

[0279] Layer-by-layer application of a suspension of solid organic substance 1 in the liquid phase can also ensure the formation of the preferred structure of the HTPM 2. In this case, after application of one or more suspensions of solid organic substance, the device is dried by selecting a mode for removing the liquid phase from the applied layers of suspension, preferably at a temperature of (20 ± 2) °C for 10 minutes in an air atmosphere. The layer-by-layer application procedure is repeated until the required coating thickness is achieved. The formation of HTPM 2, including particles of solid organic substance 1 and gas phase 3, occurs layer by layer. A similar effect can also be achieved by using a dilute suspension of particles of solid organic substance 1 in the liquid phase with a content of substance 1 of less than 50 wt.%, since in a large volume the orientation of the scales will occur parallel to the plane of the base and their settling in an orderly form with the implementation of the principle of “closed blinds”, if observed, a thin layer of scales will be sufficient to cover the color of the base, in contrast to the use of more concentrated suspensions.

[0280] Silk-screen printing is preferred for layer-by-layer application of the suspension. This method allows for the formation of "towers" of active ingredient or OE particles, since a new layer can only form on the convex areas of the previous layer. This approach improves the efficiency of the OE 4 and the volume fraction of the gas phase 3 in the GTPSM 2.

[0281] Another factor influencing the rate and nature of sedimentation of particles of solid organic matter 1 is the relative difference in the densities of the solvent and particles of solid organic matter 1. In the presence of a large difference in densities (more than 0.2 g / cm 3) solid organic matter particles will settle out of the suspension too quickly, following the "open blinds" principle, without providing sufficient coverage. At comparable densities or at a density difference of less than 0.2 g / cm 3 A slow settling of solid organic matter particles will be observed, forming HTPM 2 and maintaining the "closed blinds" principle. Maintaining the "closed blinds" principle allows for the production of HTPM 2 with high hiding power, since the solid organic matter 1 particles in the initial state have a preferential orientation parallel to the surface of the base and protective coating.

[0282] In the case of sequential application of a suspension of a solid organic substance or a mixture of such substances in the liquid phase, the areas of the front surface of the device base that should not be exposed to the first SGPM 2 are sealed with polyethylene film. A layer of the first suspension of the solid organic substance in the liquid phase is uniformly applied to the uncovered area of ​​the base using one of the methods described above or other suitable methods that ensure the formation of the target SGPM 2. After the layer obtained using one of the methods described above has completely dried, the protective film is removed. When manufacturing a device with multiple sections of identical or different SGPM 2, the procedure for applying the second and subsequent suspensions of the solid organic substance or their mixtures in the liquid phase is sequentially repeated to produce multiple sections of SGPM 2. The suspension can also be applied using screen printing, stencil printing, pad printing, casting, or other methods.

[0283] When applying a GTPM 2 thermal insulation material with a single threshold temperature to a substrate, it can be placed on one or several unconnected sections of substrate 5. When applying different GTPM 2 thermal insulation materials with two or more threshold temperatures, the corresponding compositions can be placed on sections of substrate 5, alternating them or using any necessary combination that satisfies the required thermal insulation characteristics. The choice of temperature combinations for several GTPM 2 thermal insulation materials also depends on the specific task for which the thermal insulation material is being created. For example, for a device containing two different temperature-sensitive materials, the threshold temperatures may be 50 °C, 55 °C, or 60 °C, 80 °C, or 70 °C, 90 °C, or 90 °C, 110 °C, or 80 °C, 100 °C, or 80 °C, 90 °C, or 90 °C, 100 °C, or 100 °C, 120 °C, or 110 °C, 130 °C, or 100 °C, 110 °C, or 120 °C, 140 °C, or 120 °C, 150 °C.

[0284] For a device containing three different thermosensitive materials 2, the threshold temperatures can be 50 °C, 55 °C, 60 °C, that is, the first thermosensitive material changes transparency upon reaching 50 °C, the second thermosensitive material changes transparency upon reaching 55 °C, and the third upon reaching a temperature of 60 °C, with an accuracy of 5 °C. In other embodiments, the threshold temperatures may 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.

[0285] For a device containing four different temperature-sensitive materials, the threshold temperatures may be 50 °C, 55 °C, 60 °C, 70 °C, or 50 °C, 60 °C, 70 °C, 80 °C, or 50 °C, 70 °C, 90 °C, 110 °C, or 60 °C, 70 °C, 80 °C, 90 °C, or 60 °C, 70 °C, 80 °C, 100 °C, or 60 °C, 80 °C, 90 °C, 110 °C, or 70 °C, 80 °C, 90 °C, 100 °C, or 70 °C, 90 °C, 100 °C, 120 °C, or 70 °C, 90 °C, 110 °C, 130 °C, or 80 °C, 90 °C, 100 °C, 110 °C, or 80 °C, 100 °C, 120 °C, 140 °C, or 80 °C, 100 °C, 120 °C, 150 °C.

[0286] The surface area of ​​the base 5 covered by sections of the GTPM 2 preferably comprises from 3 to 97% of the area of ​​the front surface of the base, preferably not less than 30%, which makes it possible to detect triggered TI from a long distance, and also makes it possible to detect point heating of a large surface of the installations.

[0287] The number of GTPM 2 is not limited by an upper limit and depends on the practical task implemented using the declared TI (type of equipment, required step of the determined superheating temperature, area of ​​the surface tested for heating, etc.).

[0288] In preferred embodiments, the GTPM 2 are designed with the ability to register local overheating of the surface of the test object by changing the color of only those parts of the GTPM 2 that were heated above the corresponding threshold temperatures, and maintaining the original color of the remaining surface of the GTPM 2 that were not heated above the corresponding threshold temperature, during uneven heating.

[0289] The principle of operation of the TI

[0290] The TI, which includes a base 5, at least one HTPM 2 applied to it, and a transparent polymer protective layer 6, is installed on the surface of the test object, ensuring a tight fit of the TI due to the adhesive properties of the adhesive layer of the base, the elastic properties of the base, or other characteristics of the TI.

[0291] A test object with a single applied HTPM 2 operates as follows. The applied HTPM 2 is initially opaque to at least some visible light and, in preferred embodiments, is white. Until the entire surface of the test object, or individual sections located beneath the HTPM 2, is heated to a threshold temperature, the HTPM 2 remains opaque to at least some visible light, thereby preserving the original appearance of the test object. When the surface of the test object is heated above the threshold temperature of the HTPM 2 over the entire surface or in a specific section thereof, an irreversible change in its transparency occurs. In preferred embodiments, this process is accompanied by melting of the solid organic substance 1, a decrease in the proportion of gas 3 by at least a factor of two, and an increase in the apparent density of the material.After the TI is triggered, the GTPM 2 becomes transparent and reveals the color of the base material 5 underneath it, or the color of the paint applied to the base in the area beneath the GTPM 2. Upon subsequent cooling of the surface of the tested object, the GTPM 2 or part of it remains transparent, and the device's appearance does not return to its original state. This ensures the ability to visually record temperature exceeding the threshold, both at the moment of overheating and after an extended period of time.

[0292] If the TI has several (n) zones with different HTPM 2 having different threshold temperatures Ti . Tn, then until the surface of the equipment located under the HTPM 2 is heated to the threshold temperature Ti, all HTPM 2 remain opaque, thereby preserving the original appearance of the TI. Upon reaching the threshold temperature Ti, the solid organic matter of the first HTPM 2 having the threshold temperature Ti begins to melt with a decrease in the gas proportion and, as a consequence, with an increase in the transparency of the corresponding HTPM 2 and the appearance of the color of the base 5 underneath. At the same time, other areas of the TI with HTPM 2 having threshold temperatures Tr . Tn > Ti retain their original appearance. A further increase in the surface temperature on which the TI is located to the temperature Tr . Tn will lead to a sequential irreversible change in the transparency of the corresponding HTPM 2 with threshold temperatures Tr . Tn.In this case, if the maximum surface temperature of the equipment is lower than at least one of the threshold temperatures T. п , then the corresponding zones of GTPM 2 will retain their original opacity.

[0293] Upon subsequent cooling of the test object's surface, the areas with the activated HTPM 2 remain transparent, and the TI's appearance does not return to its original state. If the equipment surface reheats to the threshold temperature of areas with HTPM 2 that previously failed to activate with the specified accuracy, an irreversible change in the transparency of the corresponding HTPM 2 will occur, revealing the color of the underlying 5.

[0294] When the surface of the test object is heated locally, a transparent zone is formed only in that area 7 of that GTPM 2 that was subjected to heating above the corresponding threshold temperature, while maintaining the original appearance of the rest of the area of ​​that GTPM 2 that was not subjected to heating.

[0295] The numerical value of the threshold temperature 8 may be applied to the front side of the base 5 or the front or back surface of the protective layer 6. In particular cases, the threshold temperature value may be applied in an area free of, but adjacent to, the protective layer 2, or directly in the area of ​​the protective layer 2, preferably above or below the protective layer 2. In the latter case, when the temperature exceeds the corresponding threshold temperature value, after an irreversible change in the transparency of the protective layer 2, the color of the base 5 and the numerical value of the threshold temperature 8 appear.

[0296] In specific embodiments of the invention, base 5 may be black, protective layer 6 may be colorless, and GTPM 2 may be white in its initial opaque state. Upon exceeding the corresponding threshold temperature, a change in the device's appearance is observed, with maximum contrast occurring during the white-to-black transition, improving the visibility of the triggered TI and facilitating visual identification of overheating. A similar design is achieved by implementing a device in which base 5 is a color other than black, protective layer 6 is colorless, and black paint is applied to the area beneath GTPM 2, which is initially white. In this case, a white-to-black color transition is also observed upon device activation.

[0297] In the case of a device in which the gas-tight protective layer 2 is hermetically sealed with an elastic transparent protective layer 6 at atmospheric pressure, the gas phase 3 and non-gaseous media 1 separate at the moment of activation of the gas-tight protective layer 2. This separation results in the formation of an "air bubble" under the surface of the protective layer 6, which shrinks as the TI cools. When using a TI with a hermetically sealed protective layer 6 and a gas pressure of 3 inside the gas-tight protective layer 2 below atmospheric pressure, the "air bubble" under the surface of the protective layer 2 may be smaller.

[0298] In other embodiments of the invention, to prevent the formation of an "air bubble" when the threshold temperature is exceeded, a gap may be provided between the transparent protective layer 6 and the base 5. Alternatively, microholes or micropores may be provided in the protective layer to allow the gas released during operation to escape.

[0299] Variants of TI in which the HTPM 2 composition includes solid organic substance 1 and a binder operate on a similar principle. When the temperature exceeds the corresponding threshold, the solid organic substance 1, glazed with a binder, melts, releasing gas 3 and separating the gaseous and non-gaseous environments. This also results in an irreversible change in the transparency of HTPM 2, typically accompanied by a decrease in the gas content.

[0300] Thus, all embodiments of the TI operate on an operating principle based on an irreversible change in the transparency of the GTPM 2 and, consequently, the TI's appearance. Moreover, upon cooling the device to 20°C and maintaining it at this temperature for at least one month, preferably one year or more, the TI's appearance does not return to its original state. In preferred embodiments of this group of inventions, the TI has a service life of at least five years, preferably at least ten years.

[0301] The TI of the claimed group of inventions can be used both in electrical engineering for monitoring the surface temperature of electrical equipment, such as complete switchgear, BRNO boxes, electrical panels, etc., and its individual elements (wires, cables, contact connections, etc.), and on other industrial or household devices requiring surface temperature monitoring.

[0302] Thus, during a visual inspection of the device, it is possible to reliably and with high accuracy record the fact of exceeding at least one temperature threshold value both over the entire surface of the controlled object and in its section, which will ensure increased operational safety of electrical equipment or other controlled object.

[0303] Method of testing TI

[0304] To test the declared TI, a method can be implemented in which:

[0305] - form a representative sample of TI in a production batch of TI;

[0306] - for each TI sample, the numerical value of the brightness coefficient of the GTPM layer (TI) is determined;

[0307] - each TI of the sample is subjected to an external influence: (1) it is placed in an autoclave and maintained at a given excess pressure for a given period of time, or (2) each TI of the sample is secured to a solid surface, and a given compressive load of a given value is applied to the TI along the normal to the selected area of ​​the CGPM layer for a given period of time; - the numerical value of the luminance coefficient of the CGPM layer is determined again for each TI of the sample; the initial and re-determined numerical values ​​of the luminance coefficient are compared for each TI, and the quality of the TI is determined based on compliance with the established criteria.

[0308] In specific cases, testing of TIs can be carried out as follows. Taking into account the size of the production batch and its other statistically significant characteristics, a representative sample of TIs is formed.

[0309] For TI from a representative sample containing one GTPM 2 and corresponding to the disclosure of the first or second inventions of the group, manufactured by methods representing the third, fourth or fifth inventions of the group, the luminance coefficient (ki) of the layer of this GTPM 2 is measured in the initial state immediately after manufacture or within no more than one month after manufacture, provided that the appropriate storage conditions are met.

[0310] According to a first alternative embodiment of the test method, a representative sample of the TI is placed in an autoclave into which an inert gas, preferably argon, is pressurized, thereby creating an excess pressure of preferably at least 1013 kPa (10 atm), most preferably at least 5066 kPa (50 atm) at room temperature. The TI is maintained under these conditions for at least 10 min, preferably at least 1 hour, most preferably at least 24 hours, the excess pressure is relieved, and the TI is removed from the autoclave.

[0311] According to a second alternative embodiment of the test method, a representative sample of the testing instrument is placed on the support plate of a compression testing fixture similar to that described in Appendix B of GOST 25.503-97. An axial compressive load is uniformly applied to the specimen at a relative strain rate of no more than 3 MPa / s. The specimen is loaded until it reaches the nominal stress, preferably no less than 20 kPa, and most preferably no less than 10 MPa. The device is maintained under these conditions at room temperature for at least 1 min, preferably no less than 30 min, and most preferably no less than 1 h. The device is removed from the compression testing fixture.

[0312] A repeated measurement of the luminance coefficient (kg) of the GTPM 2 TI layer is carried out.

[0313] Compare the obtained values ​​of ki and kg and present the results in one of the following forms: as the difference between their values

[0314] L.k = ki - kg, or in the form of relative changes in their values, expressed as a percentage

[0315] Dk (%) = 100 (ki - kT) / ki.

[0316] The maximum permissible value of Lk can be determined by the manufacturer during the manufacturing of the measuring instrument based on the conditions under which the measuring instrument will be used. For example, the measuring instrument can be considered to have passed the test if Lk < 10% (if the Lk value is expressed as a percentage).

[0317] The test method may also include both alternatives, carried out in any order.

[0318] In the case of a TI with multiple regions of a single GTPM 2 or with multiple GTPM 2, the luminance factor must be determined for each region separately. Comparisons of luminance factor values ​​should be performed for the corresponding regions of GTPM 2 separately.

[0319] Carrying out testing of the TI from the claimed group of inventions using the specified method ensures a clear, regulated verification of their resistance to mechanical impacts while maintaining functional characteristics.

[0320] Below are presented preferred embodiments of the claimed group of inventions, which are illustrative and in no way limit the scope of the requested legal protection of the inventions.

[0321] Examples

[0322] Example 1. Manufacturing of a TI in accordance with the first invention of the group

[0323] Preparation of the HTPM. 100 g of solid organic material, n-docosylamine with a melting point of 65°C, is ground to a particle size of 2-3 µm. 300 g of liquid phase, an acrylic dispersion in water, is added, and the mixture is stirred, periodically dispersing it with air access, until a constant density is achieved. The suspension is applied immediately after preparation.

[0324] Substrate preparation. Oramask 831 black PVC film, 0.2 mm thick, is used as the substrate. The back surface of the substrate is coated with an adhesive layer protected by a siliconized release agent. The area of ​​the substrate to be coated with the GTPN is laser-cut to form uniform indentations on the substrate surface. These indentations are made as longitudinal stripes 0.1 mm deep, spaced 0.15 mm apart.

[0325] Manufacturing of the TI. A suspension of the active ingredient is applied in seven layers using silk-screen printing. After each layer is applied, it is dried in a vacuum chamber at a pressure of 13.3 kPa (100 mmHg) and a temperature of 20°C for one hour. The average thickness of the TI is 0.15 mm. The TI blank is then coated with a smooth, transparent, colorless protective layer made of 0.025 mm thick PVC, bonding the base and protective layer using cold lamination at a reduced pressure of 26.6 kPa (200 mmHg).

[0326] Activation of the TI. After removing the release, the TI is secured to the heated surface using the adhesive properties of the adhesive layer. The surface is heated in a controlled manner at a rate of 5°C / min to a temperature of 65°C with a specified accuracy. Heating is stopped, and the activation of the device is visually recorded as a change in the TI's appearance. The time required for the change in the TI's appearance is 2 seconds. After the device has cooled to room temperature, visually record that the TI's appearance has not returned to its original state.

[0327] Example 2. Manufacturing of a TI in accordance with the first invention of the group (variant)

[0328] Preparation of the HTPM. Yttrium behenate (with a phase transition temperature of 90°C), lanthanum palmitate (with a phase transition temperature of 100°C), and lanthanum nonadecynate (with a phase transition temperature of 110°C) are used as the substances for the preparation of the HTPM. A mixture of methanol and ethylene glycol monomethyl ether (50 / 50 vol%) is used as the liquid phase. Each solid organic substance (100 g) is individually ground to a particle size of 2-3 µm. 200 g of the liquid phase is added and mixed, ensuring periodic dispersion of the mixture with access to air, until a constant mixture density is reached. The resulting suspensions are used for application immediately after preparation.

[0329] Preparing the base and protective layer. A smooth film of red M-40 fluoroplastic, 0.1 mm thick, is used as the base material. The base is a hollow tube of constant diameter. Black paint is applied using solvent dyes to the area of ​​the base that will be covered by the PTFE, and the corresponding threshold temperature values ​​are applied to the area free of the PTFE. A transparent, colorless polyurethane film modified with 15% trichloroisopropyl phosphate, 0.05 mm thick, is used as the protective layer. The area of ​​the protective layer that will touch the PTFE is sandblasted to form irregular indentations on the back surface of the protective layer.

[0330] Manufacturing of the TI. The back surface of the protective layer, where the first HTPM should not be applied, is sealed with polyethylene film. The first suspension of the active ingredient of the HTPM is applied to the area free of the film using silk-screen printing in five layers. After applying each layer, dry for 24 hours at room temperature. Once the HTPM is completely dry, remove the film. The procedure is repeated for the remaining two suspensions of active ingredients of the HTPM. The average thickness of each HTPM is 0.05 mm. The protective layer with the applied HTPM is attached to the base by welding.

[0331] Activation of the heating element. The heating element is installed on a cylindrical heated surface of the appropriate diameter, ensuring a tight fit due to the elastic properties of the base and protective layer. The surface is heated in a controlled manner at a rate of 5°C / min to a temperature of 90°C with a specified accuracy. Heating is stopped, and the activation of the corresponding area of ​​the heating element is visually recorded by a change in the appearance of the first heating element while the appearance of the remaining heating elements remains unchanged. The time required for the change in appearance of the first heating element is 2 seconds. After the heating element cools to room temperature, it is visually recorded that the heating element does not return to its original state.

[0332] The heating and cooling cycles are then repeated twice (to temperatures of 100°C and 110°C with the specified accuracy). The time it takes for the appearance of each HTPM to change is recorded: for the second HTPM, it is 3 seconds, and for the third HTPM, it is 2 seconds. After each cooling of the device to room temperature, visually verify that the TI's appearance does not return to its original state.

[0333] Example 3. Manufacturing of a TI in accordance with the second invention of the group

[0334] Preparation of support elements. Glass beads with a diameter of 0.06-0.07 mm are used as supporting elements. The beads are treated with hydrofluoric acid to create a developed surface.

[0335] Preparation of the HTPM. 100 g of solid organic material, erucamide with a phase transition temperature of 80 °C, is ground to a particle size of 2-3 µm. 500 g of liquid phase, a 3% solution of polyvinyl butyral in ethanol, and 50 g of prepared EO are added successively. The mixture is stirred, ensuring periodic dispersion with access to air, until a constant density is achieved. The suspension is applied immediately after preparation.

[0336] Manufacturing of the TI. The base material is a smooth, green, reflective film made of a copolymer of vinyl chloride and vinylidene chloride, 0.2 mm thick. The back surface of the base is coated with an adhesive layer protected by a siliconized release liner. The area of ​​the base that should not be coated with the TI is sealed with polyethylene film. A suspension of the active substance of the TI is applied to the film-free area using silk-screen printing in 5 layers. After applying each layer, it is dried in a thermostat at 60°C for three hours. After the TI has completely dried, the film is removed. The average thickness of the TI is 0.1 mm. The TI blank is covered with a smooth, transparent, colorless protective layer made of 0.1 mm thick PVC, bonding the base and protective layer using cold lamination under a reduced pressure of 53.2 kPa (400 mmHg).

[0337] Activation of the TI. After removing the release agent, the TI is placed on the heated surface and adhered to it using the adhesive properties of the adhesive layer. The surface is heated in a controlled manner at a rate of 5°C / min to a temperature of 80°C with a specified accuracy. Heating is stopped, and the activation of the device is visually recorded, indicating a change in the TI's appearance. The time required for the change in the TI's appearance is 4 seconds. After the TI has cooled to room temperature, visually confirm that the TI's appearance does not return to its original state.

[0338] Example 4. Manufacturing of a TI in accordance with the second invention of the group (variant)

[0339] Preparation of the HTPM. 100 g of the solid organic substance, zinc palmitate with a phase transition temperature of 140 °C, is ground to a particle size of 2-3 µm. 300 g of the liquid phase, a 30% nitrocellulose solution in ethanol, is added. The mixture is stirred, ensuring periodic dispersion with access to air, until a constant density is achieved. The suspension is applied immediately after preparation.

[0340] Preparing the base. The base material is 0.2 mm thick, yellow, luminescent siliconized paper. A fine-mesh metal mesh, 175 µm thick, is welded to the area of ​​the base that will be covered with the HTPM. A black solvent-based dye is applied to the area of ​​the base with the mesh. The back surface of the base is coated with an adhesive layer protected by a siliconized release agent.

[0341] Manufacturing of the TI. The area of ​​the base where the HTPM should not be applied is sealed with polyethylene film. A suspension of the active substance of the HTPM is applied to the area free of the film using silk-screen printing in six layers. After applying each layer, it is dried in a vacuum chamber at a pressure of 26.6 kPa (200 mmHg) and a temperature of 20°C for one hour. After the HTPM has completely dried, the film is removed. The average thickness of the HTPM is 0.25 mm. The TI blank is covered with a smooth, transparent, colorless protective layer made of 0.1 mm thick PVC. The base and protective layer are bonded using cold lamination at a reduced pressure of 26.6 kPa (200 mmHg).

[0342] Activation of the TI. After removing the release, the TI is placed on the heated surface and adhered to it using the adhesive properties of the adhesive layer. The surface is heated in a controlled manner at a rate of 5°C / min to a temperature of 140°C with a specified accuracy. Heating is stopped, and the TI's activation is visually recorded by a change in its appearance. The time it takes for the TI to change its appearance is 2 seconds. After the device cools to room temperature, visually confirm that the TI's appearance does not return to its original state.

[0343] Below are examples of testing temperature indicators manufactured in accordance with Examples 1-4. When using a representative sample, standard methods for determining sample representativeness and statistical methods can be used.

[0344] Example 5. Method of testing the TI manufactured in Example 1

[0345] For the TI manufactured in Example 1, the manufacturer specifies that the TI is considered to have passed the test if the luminance coefficient of the thermosensitive layer decreases by no more than 3% relative to the initial values. Using a colorimeter calibrated using white and black plates, the luminance coefficient of the TI manufactured in Example 1 is measured in the area of ​​the heat-sensitive layer. The ki value is equal to 0.83. The TI is then placed in an autoclave at room temperature. Argon is supplied to the autoclave until a pressure of 1013 kPa (10 atm) is reached, and the TI is maintained under these conditions for 24 hours, the excess pressure is removed, and the TI is removed from the autoclave. The luminance coefficient of the TI is measured again. The value is equal to 0.81. Thus, the decrease in luminance coefficient Ak is 100 (0.83 - 0.81) / 0.83 = 2.4%, which means that the TI manufactured in Example 1 has passed the test.

[0346] Example 6. Method of testing the TI manufactured in Example 2.

[0347] For the TI manufactured in Example 2, the manufacturer specifies that the TI is considered to have passed the test if the luminance coefficient of the thermosensitive layer decreases by no more than A ref = 0.05 relative to the initial values. Using a colorimeter calibrated using white and black plates, the luminance coefficient of the TI manufactured in Example 2 is measured in the area of ​​the heat-sensitive layer. The ki value is equal to 0.85. Then, the TI is mounted at room temperature on the support plate of the compression testing device. An axial compressive load is uniformly applied to the sample at a relative deformation rate of 0.3 MPa / s until the nominal stress of 1 MPa is reached. The TI is maintained under these conditions for 10 min, after which it is removed from the device and the luminance coefficient of the TI is measured again in the area of ​​the heat-sensitive layer. The k2 value is equal to 0.84. Thus, the difference in the values ​​of the luminance coefficients Lk is 0.01, which satisfies the condition Lk < Dk реf and means that the TI manufactured in example 2 passed the test.

[0348] Example 7. Method of testing the TI manufactured in Example 3

[0349] For the TI manufactured in Example 3, the manufacturer specifies that the TI is considered to have passed the test if the luminance coefficient of the thermo-sensitive layer decreases by no more than 2% relative to the initial values. Using a colorimeter calibrated using white and black plates, the luminance coefficient of the TI manufactured in Example 3 is measured in the area of ​​the heat-sensitive layer. The ki value is equal to 0.85. The TI is then placed in an autoclave at room temperature. Argon is supplied to the autoclave until a pressure of 10132 kPa (100 atm) is reached and the TI is maintained under these conditions for 10 min, after which the excess pressure is removed and the TI is removed from the autoclave. The luminance coefficient of the TI is measured again in the area of ​​the heat-sensitive layer. The value equals 0.84. Thus, the decrease in the luminance coefficient Ak = 100 • (0.85 - 0.84) / 0.85 = 1.2%. This means that the TI manufactured in example 3 passed the test.

[0350] Example 8. Method of testing the TI manufactured in Example 4

[0351] For the TI manufactured in Example 4, the manufacturer specifies that the TI is considered to have passed the test if the luminance coefficient of the thermo-sensitive layer decreases by no more than 5% relative to the initial values. Using a colorimeter calibrated using white and black plates, the luminance coefficient of the TI manufactured in Example 4 is measured in the area of ​​the heat-sensitive layer. The ki value is equal to 0.82. The TI is then mounted on the support plate of the compression testing device at room temperature. An axial compressive load is uniformly applied to the sample at a relative deformation rate of 1 kPa / s until the nominal stress of 20 kPa is reached. The TI was maintained under these conditions for 24 hours, after which it was removed from the device and the luminance coefficient of the TI in the area of ​​the heat-sensitive layer was measured again. The value equals 0.79. Thus, the reduction in the luminance coefficient Dk = 100 (0.82 - 0.79) / 0.82 = 3.6%. This means that the TI manufactured in example 4 passed the test.

[0352] Example 9. Method for testing a TI manufactured by a method known from the prior art

[0353] For a TI manufactured by a method known from the prior art using yttrium behenate with a phase transition temperature of 90 °C as the substance for preparing the HTPM and methanol as the liquid phase, the manufacturer specifies that the TI is considered to have passed the test if the luminance coefficient of the heat-sensitive material decreases by no more than 5% relative to the initial values. Using a colorimeter calibrated using white and black plates, the luminance coefficient of the TI in the area of ​​the heat-sensitive layer is measured. The ki value is equal to 0.81. Then the TI is placed in an autoclave at room temperature. Argon is supplied to the autoclave until a pressure of 10132 kPa (100 atm) is reached and the TI is maintained under these conditions for 10 min, the excess pressure is removed and the TI is removed from the autoclave. The luminance coefficient of the TI in the area of ​​the heat-sensitive layer is measured again. The value equals 0.63. Thus, the reduction in the luminance coefficient Afc = 100 (0.81 - 0.63) / 0.81 = 28.6%. This means that the TI manufactured by the method known from the prior art failed the test.

Claims

CLAUSES OF THE INVENTION 1. A temperature indicator (TI) for visually recording the excess of at least one temperature threshold value, comprising: - basis; - at least one gas-filled hot-melt material (GFTM), located on the section / s of the front surface of the base, designed with the possibility of an irreversible change in transparency when heated above a threshold temperature due to the melting of a substance or group of substances included in the GFTM; - a protective layer, transparent to at least part of the visible light, covering the HTPM and at least part of the base free of the HTPM, characterized in that at least part of the HTPM is located between support elements (SE) made in the material of the base and / or the protective layer.

2. A temperature indicator according to claim 1, characterized in that the EO are made from the base material and / or protective layer and are multiple protrusions on the surface of the base and / or protective layer, between which at least part of the GTPM is located, and / or recesses made in the base material and / or protective layer, at least partially filled with the GTPM.

3. A temperature indicator according to paragraph 1 or 2, characterized in that additional elements are located inside the GTPM, the melting temperature of which is higher than the operating temperature of the GTPM, and the compressive strength of which is higher than the compressive strength of the GTPM.

4. A temperature indicator for visually recording the excess of at least one temperature threshold value, comprising: - basis; - at least one gas-filled hot-melt material (GFTM), located on the section / s of the front surface of the base, designed with the possibility of an irreversible change in transparency when heated above a threshold temperature due to the melting of a substance or group of substances included in the GFTM; - a protective layer, transparent, at least for part of the visible light, covering the HTPM and at least a part of the base free from the HTPM, characterized in that multiple support elements (SE) are located inside the HTPM, the melting temperature of which is higher than the operating temperature of the HTPM and the compressive strength of the SE is higher than the compressive strength of the HTPM.

5. A temperature indicator according to item 4, characterized in that at least some of the EOs are in contact with the base or are attached to the base and / or in contact with the protective layer or are attached to the protective layer.

6. A temperature indicator according to item 4, characterized in that at least part of the supporting elements are made of an absorbent material, in particular of fibrous material, microcellulose, polysaccharides, silica gel, zeolites, metal oxides, aerosil.

7. A temperature indicator according to item 4 or 5, characterized in that the transparency of the support elements before the activation of the thermal insulation material is less than the transparency of the support elements wetted with the thermal insulation material melt after activation.

8. A temperature indicator according to paragraph 1 or 4, characterized in that at least part of the OE has a developed surface, with a specific surface area of ​​at least 0.2 m 2 / G.

9. A temperature indicator according to paragraph 1 or 4, characterized in that, in the presence of voids between the OE and the gas-turbine material, the volumetric content of gas in the voids is no more than 30%, preferably no more than 10% of the volume of the gas-turbine material.

10. A temperature indicator according to paragraph 1 or 4, characterized in that at least one of the conditions (a)-(d) is met: (a) the distance L(OE) between at least part of the OE is comparable to the average thickness h cp (GTPM), the GTPM layer is preferably L(OE) ~ (0.1-10) h cp (GTPM), most preferably L(OE) (1-5) h cp (GTPM). In absolute values, L(OE) is preferably in the range from 50 to 1250 µm; (b) effective height h эф (OE), at least part of the OE is 20-100% of the average thickness h cp (GTPM) layer of the GTPM, preferably is not less than 0.3 h cp (GTPM), most preferably not less than 0.7 h cp (GTPM). In absolute values ​​h эф (OE) is preferably in the range of 35 to 175 µm; (in) h cp (GTPM) does not exceed 1000 μm, preferably does not exceed 500 μm, most preferably is in the range from 50 to 250 μm; (d) the thickness of the base h(Osn) does not exceed 200 μm, preferably does not exceed 100 μm; (d) the thickness of the protective layer h(3C) does not exceed 100 µm, preferably does not exceed 25 µm.

11. A temperature indicator according to paragraph 1 or 4, characterized in that the gas-fired power plant is hermetically sealed from the environment by a protective layer, and / or the gas pressure in the gas-fired power plant is below atmospheric pressure, preferably less than 53.2 kPa (400 mm Hg), most preferably less than 26.6 kPa (200 mm Hg).

12. A temperature indicator according to claim 1 or 4, characterized in that the base and / or protective layer are made of halogen-containing polymers, preferably of polyvinyl chloride, most preferably of cast polyvinyl chloride, and / or the protective layer above the thermal insulation material is painted and / or the front surface of the base under the thermal insulation material is painted.

13. A temperature indicator according to paragraph 1 or 4, characterized in that at least one substance of the HTPM has a molecular weight of less than 2 kDa, contains a structural fragment C nH(2n+i), where n > 5 and is preferably selected from the group consisting of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 12; salts of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C n H(2n+i) with n > 5; amides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 5; anhydrides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n > 10; fatty aliphatic alcohols containing structural fragments C n H(2n+i) with n > 14; fatty aliphatic amines containing structural fragments C n H(2n+i) with n > 17; nitriles of fatty aliphatic acids containing structural fragments C nH(2n+i) with n>19; and it is preferably selected from the group consisting of palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearic alcohol, cetyl alcohol, salts of saturated fatty carboxylic acids of rare earth metals, in particular lanthanum, yttrium, ytterbium, scandium.

14. A temperature indicator according to paragraph 1 or 4, characterized in that the gas is uniformly distributed inside the gas-fuel mixture, and its share in the gas-fuel mixture is not less than 10 vol.%, and upon reaching the corresponding threshold temperature, its volume share in the gas-fuel mixture is reduced, preferably by not less than two times.

15. A method for manufacturing a temperature indicator according to paragraph 1, during the implementation of which: - multiple OEs are formed on the surface of the entire base and / or protective layer or on individual sections of the surface of the base and / or protective layer; - one or more layers of at least one suspension of at least one solid substance in a liquid phase, the boiling point of which is below 180 °C, are applied to the sections of the base and / or protective layer containing the OE, in such a way that at least part of the formed GTPM is located between the OE, wherein the proportion of the liquid phase is at least 50 wt.%, and the solubility of the solid substance in the liquid phase does not exceed 100 g / kg; - remove the liquid phase from the applied layers of suspension to form a gas-temperature-resistant composite; - connect the base and the protective layer and fasten them by gluing or welding.

16. The method according to item 15, characterized in that the formation of multiple OEs on the base and / or protective layer is carried out by embossing, engraving, molding, or sandblasting, and / or the method additionally includes etching the OE to obtain a developed surface on at least part of the surface of the OE.

17. The method according to item 15, characterized in that the suspension of at least one solid organic substance in the liquid phase additionally contains multiple EOs.

18. A method for manufacturing a temperature indicator according to clause 4, during the implementation of which: - one or more layers of at least one suspension of at least one solid substance and multiple OEs in a liquid phase, the boiling point of which is below 180 °C, are applied to the base sections, wherein the proportion of the liquid phase is at least 50% by weight, and the solubility of the solid substance in the liquid phase does not exceed 100 g / kg; - remove the liquid phase from the applied layers of suspension to form a HTPM, inside which multiple EOs are located; - connect the base and the protective layer and fasten them by gluing or welding.

19. A method for manufacturing a temperature indicator according to paragraph 4, during the implementation of which: - a material containing multiple OEs is applied to some areas of the base and / or protective layer; - one or more layers of at least one suspension of at least one solid substance in a liquid phase, the boiling point of which is below 180 °C, are applied to the areas of the base and / or protective layer containing the OE, wherein the proportion of the liquid phase is at least 50% by weight, and the solubility of the solid substance in the liquid phase does not exceed 100 g / kg; - remove the liquid phase from the applied layers of suspension to form a gas-temperature-resistant composite; - connect the base and the protective layer and fasten them by gluing or welding.

20. A method for testing a temperature indicator (TI) according to paragraph 1 or 4, during which: - form a representative sample of TI in a production batch of TI; - for each TI sample, the numerical value of the brightness coefficient of the GTPM layer (TI) is determined; - each TI sample is subjected to an external influence: (1) it is placed in an autoclave and maintained at a given excess pressure for a given period of time, or (2) each TI sample is secured to a solid surface, and a given compressive load of a given value is applied to the TI normally to the selected area of ​​the GTPM layer for a given period of time; - the numerical value of the luminance coefficient of the GTPM layer is re-determined for each TI sample; the initial and re-determined numerical values ​​of the luminance coefficient for each TI are compared, and the quality of the TI is determined based on compliance with the established criteria.

21. The method according to claim 20, characterized in that the specified excess pressure is at least 1013 kPa (10 atm), and the holding time is at least 10 min and / or the specified compressive load is less than 20 kPa, and the holding time is at least 1 min.

22. The method according to paragraph 20, characterized in that for the TI from the representative sample, numerical values ​​of the accuracy and / or speed of recording at least one threshold temperature before and after external influence (1) or (2) are additionally determined.

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