RU223350U1 - Halogen-containing temperature indicator clip - Google Patents

Abstract

The utility model relates to devices for recording exceeding a threshold temperature, namely to devices that are a clip that allows you to register the fact that wires and other elements of electrical equipment exceed a given temperature. A device for recording the excess of a threshold temperature, designed to be installed on wires, which is an elastic material base, opaque to at least part of visible light, including halogen-containing polymers, made in the form of a clip, partially coated on the front side with a heat-sensitive material that irreversibly changes transparency relative to the initial state when heated to a threshold temperature. The utility model improves the safety of operation of contact connections of electrical equipment due to the irreversible registration of heating using a self-extinguishing thermal indicator clip, which makes it possible to install and replace it without negatively affecting the electrical equipment. 20 salary f-ly, 21 ave., 8 ill.

Description

Field of technology to which the claimed utility model relates

The utility model relates to devices for recording exceeding a threshold temperature, namely to devices that are a clip that allows you to irreversibly register the fact that wires and other elements of electrical equipment exceed a given temperature.

State of the art

An increase in temperature is one of the first and most common signs of the development of defects in various equipment, such as an increase in transient contact resistance in the electric power industry, malfunctions of bearings in mechanics, interturn short circuits in the windings of electric motors, failure of chargers or batteries in household appliances. Timely detection of such overheating allows the malfunction to be eliminated in advance, to prevent equipment damage, emergency situations and associated fires or shutdowns. Technical and regulatory documents establish maximum permissible temperatures, heating above which should be considered a defect requiring immediate cessation of operation and removal of 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.).

It is especially important to identify at an early stage overheating of wires in electrical panels 220-380 V of buildings and structures for residential, social or industrial purposes, since such panels, as a rule, have a large fire load, and fires that occur in electrical panels can lead to a major fire, material damage and loss of life.

To identify defects associated with exceeding the maximum permissible temperatures of electrical equipment and wires, various diagnostic methods are used. Means of continuous monitoring of overheating include chemical or mechanical temperature indicators, which can be of two types: reversible (changing appearance only when heated and returning it when cooled) and irreversible (changing appearance after exceeding a given temperature and maintaining it after cooling).

Structurally, most temperature indicators are stickers with a heat-sensitive layer applied to the front surface. An example of such devices for controlling overheating is the invention described in document US 7600912 B2 (publication date March 20, 2007) and which is a single-layer or two-layer sticker, the heat-sensitive element of which contains leuco dyes and a developer in a binder. When a certain temperature is reached, the binder melts and the developer reacts with the dye, coloring the label. After lowering the temperature, the dye crystallizes and the color is restored. The peculiarity of this kind of inventions is that they make it possible to inform only about the current heating temperature, and not about the maximum temperature to which the controlled element of electrical equipment was heated at the moment of maximum load.

Unlike reversible indicators, irreversible indicators allow not only to identify, but also to record the fact that a threshold temperature has been exceeded. The use of irreversible thermal indicators makes it possible to assess the condition without creating a maximum load mode, both on operating equipment and on equipment taken out for repair.

Irreversible heating indicators can be classified according to their operating principle. Indicators are known that are based on the mechanical destruction of a temperature-sensitive element, on the chemical reaction of components of a thermal composition, or on the phase transition of a temperature-sensitive component.

An example of a temperature indicator based on mechanical destruction is described in the source [US 6176197 B1, publication date 02.11.1998], according to which the temperature indicator is a closed hollow transparent elongated tube with two compositions different in color, isolated from each other by a polymer partition having melting temperature close to the melting temperatures of the compositions. When a given threshold temperature is reached, the partition is destroyed, the compositions melt and mix. As a result, the color of the tube's contents changes. Features of the invention include the impossibility of controlling overheating of the entire surface. Such products are not suitable for detecting short-term overheating, as they are characterized by a long response time: to complete the color transition, it is necessary not only to completely melt the indicator compositions and the polymer membrane separating them, but also to spend time mixing the resulting liquid phases, which can be difficult due to slow diffusion processes near the melting point. The design features of the described invention do not allow the creation of a flexible device that fits tightly to the entire controlled surface, and also does not imply any fastening elements that allow the device to be securely fixed.

The chemical reaction of etching a metal substrate with an activator, which begins when a certain temperature is reached, is described in the patent [EP 2288879 B1, publication date 06/04/2008]. The indicator changes color from silver-white or mirror-like to colorless and can be used for temperature monitoring in food, medical, and electrical equipment. The metal layer and the activator layer can be applied to a thin film made in the form of a sticker, which ensures the flexibility of the product and the ability to be attached to various surfaces. Among the commercially available indicators, the operating principle of which is based on a chemical reaction, we can highlight indicator stickers of the Retomark model, supplied by YALOS Innovation Company LLC (hnps://www.yalosindicator.com/product/termoindikatory).

The presented irreversible thermal indicators, the operating principle of which is based on chemical reactions, are characterized by low accuracy, since, in accordance with the Arrhenius equation, the rate of a chemical reaction is determined not only by temperature, but also by time. At the same time, the above standards regulate specific threshold temperature values with an accuracy of at least 5°C, regardless of the time of exposure to temperature, which makes the described inventions unsuitable for recording defects in electrical equipment. Another feature of such devices is the presence of a pronounced dependence of the response time on temperature: with short-term heating to a threshold value, the chemical reaction may not be completed and a change in the color of the indicator either will not occur or will be insufficient for detection. In addition, due to the reversibility of color transition reactions, it is possible for the triggered indicator to return to its original color after a long exposure at low temperature.

A separate disadvantage of indicators based on mechanical or chemical principles is also that when the layer of the thermosensitive element is deformed, premature operation of the indicator may occur, and their initial design in the form of devices with a shape other than flat is not always possible.

The most accurate temperature indicators are those based on a phase transition, namely the melting of a heat-sensitive component. Since, unlike a chemical reaction, the phase transition temperature does not depend on the exposure time, such indicators have the greatest accuracy and are capable of maintaining the original state for a long time at a temperature slightly lower than the threshold.

Irreversible indicators based on the principle of phase transition of a temperature-sensitive component can be made in the form of thermal indicator paint. A thermochromic indicator containing a substrate and a coating with particles of solid crystalline material, air voids and a small amount, for example 5-40% by weight of the coating, of a binder, is described in the source US 2010247900 A1, publication date 09/30/2010. In this case, the particle size of the material must be such that the coating has high opacity at a temperature below the melting onset temperature due to scattering of visible light, which decreases when the melting onset temperature is reached with the formation of a transparent coating when the melting onset temperature is reached. A feature of this invention is the large temperature range at which a change in transparency occurs, as well as the long response time of the device.

Thermal indicator paints or varnishes can be applied to any surface shape. The use of temperature indicator paints and varnishes, the principle of operation of which is based on the melting of pigment, is described in a number of documents, including, for example, CN 112322134 A (publication date 09/23/2020), CN 111849346 A (publication date 07/11/2020), CN 108610694 A (date of publication 09.12.2016), SU 1765145 A1 (date of receipt 30.10.1989), SU 576334 A1 (date of publication 25.05.1976). Typically, such paints consist of synthetic resins, fillers and heat-sensitive components dispersed in water or a solvent. When heated above a given temperature, the heat-sensitive component melts, which leads to a change in the color of the composition due to a change in the refractive index. As a rule, after cooling, the color of such compositions does not change or changes slightly, which makes it easy to record the fact of overheating during visual inspection. Indicator paints have a number of features, which include:

It is impossible to indicate the temperature on the paint. During a visual inspection of the equipment, the operator can only see the fact that the temperature has been exceeded, but cannot determine the numerical value of the exceeded threshold. To do this, you need to make special notes;

dripping of indicator paint when the threshold temperature is exceeded. When exposed to temperature and melting of a heat-sensitive component, paint can drain from the surface and get onto open elements of the electrical installation or moving parts of mechanisms, which can lead to a short circuit or the creation of an insulating environment between the contacts, a decrease in the electrical strength of the insulation, heating, jamming, failures, fires, etc. accidents;

impossibility of applying a uniform layer to complex surfaces. The consequence of this is the impossibility of determining the exact temperature, since the thicker the layer, the higher the difference between the temperature of the surface and the phase transition (triggering);

low adhesion and difficulty in applying paint to wires made of non-adhesive materials (silicone, polyethylene, fluoroplastic). A large amount of hot-melt pigment required for clear visualization of overheating, as a rule, leads to a decrease in the proportion of polymer binder in the composition and reduces paint adhesion. This leads to the fact that the composition is easily separated from the controlled surface under mechanical stress;

the dependence of the paint response temperature on the chemical composition of the surface on which it is applied. Because the paint comes into direct contact with the material to which it is applied, such as cable insulation or engine housing paint, various substances, primarily flame retardants and plasticizers, can be extracted into the temperature indicator paint. Such substances may result in the formation of eutectic mixtures with the hot melt component or otherwise affect the response temperature.

Another option for thermal indicators based on the phase transition of a temperature-sensitive component is thermal indicator stickers. Thermal indicator stickers do not have a number of disadvantages inherent in indicator paints. So, the response temperature may be indicated on the sticker. The heat-sensitive composition and adhesive layer are applied at the factory in a uniform thin layer onto the polymer base. This approach ensures specified response and adhesion characteristics regardless of operating conditions. The polymer base prevents contact of the heat-sensitive composition with the surface of the controlled element. In addition, most thermal indicator stickers are additionally covered with a polymer film, which protects the hot-melt composition from mechanical or chemical influence and does not allow it to drain when melted after activation. Among the main manufacturers of thermal indicator stickers are: TermoElectrika LLC (https://www.lesiv.pro/%D0%BA%D0%BE%D0%BF%D0%B8%D1%8F-l-mark-pro) , LLC “Innovative Company “YALOS” (https://www.yalosindicator.com/product/termoindikatory-kontrol-temperatury), CJSC “NPF “Luminofor” (https://luminophor.ru/catalog/termoindikatomye-materialy/termoindi plavleniya-marki-tin/).

As noted earlier, temperature indicators are used in a wide variety of areas. The highest technical requirements are placed on temperature indicators used in the electrical power industry.

Thus, for the safe use of temperature indicators in the electric power industry, the device must have a number of necessary characteristics:

have low flammability and flammability;

have high electrical strength and dielectric properties;

irreversibly register exceeding threshold temperatures;

ensure the required response accuracy; have flexibility and strength;

have good fixation on the controlled element for a tight fit to various surfaces.

Moreover, a device with such characteristics can be used in any other field.

For the most rapid and reliable detection of defects accompanied by overheating of electrical equipment elements, it is necessary to have close contact of the thermal indicator with the controlled surface, without air gaps that reduce the speed and efficiency of heating of the thermal indicator due to the low thermal conductivity of the air. In addition, temperature indicators must be conveniently and securely attached to the controlled elements, without peeling off from them during operation.

To use temperature indicators to record the excess temperature of the surface of electrical equipment elements or various mechanisms, it is necessary to take into account that often the surface of such elements has a complex geometry with a radius of curvature of 2 mm (for example, small-section electrical wire strands with or without insulation, steel-aluminum wires of overhead power lines, hardware clamps, surface of coils, blades of bolted contact connections, contact lamellas, jaws of contact connections of fuses, etc.). The surfaces of metal conductive elements can constantly expand/contract due to multiple heating/cooling cycles caused by changes in load current.

Installation of thermal indicator stickers on contact connections of wires and other elements of electrical equipment with a small radius of curvature leads to large deformation of both the material of the sticker itself and its adhesive layer, as well as the heat-sensitive layer. This can lead to the fact that after removing the pressure with which this sticker was glued to a curved surface, the elastic force will exceed adhesion (the force of adhesion of the sticker to the surface), as a result of which the sticker will tend to take its original shape and partially (completely) peel off from the surface . The same thing can happen when the linear dimensions of the controlled surface change, including due to thermal expansion of the surface material when it is heated.

Manufacturers of thermal indicator stickers in their documentation often indicate the need to install their products on flat surfaces, which is associated not only with their insufficient flexibility and elasticity, but also with the fact that deformation may cause loss of the functional properties of heat-sensitive materials. Such stickers cannot be used for temperature control of surfaces that have a small radius of curvature, surfaces of complex shape, as well as surfaces that can change their linear parameters, since the reliability of recording temperature increases will be significantly reduced.

The reasons for this are:

in the case of using heat-sensitive materials based on the destruction of the membrane, premature operation may occur due to additional load on the membrane or physical damage to the integrity of the device elements during installation;

When the sticker is deformed, the heat-sensitive material may peel off from the base, as well as cracks may form on its surface. As a result, false alarms will occur or a decrease in the visibility of the triggered device will be observed, caused by insufficient heating of the heat-sensitive material when the threshold temperature is exceeded;

In the area where the sticker peels off from the controlled surface, an air bubble may form, which will act as thermal insulation. The latter can lead to “non-operation” of the thermal indicator due to the difference in the temperatures of the controlled surface and the heat-sensitive material or a decrease in the response speed;

uneven heating of the surface of the heat-sensitive material in the area of sticker peeling, in which part of the layer of heat-sensitive material changes appearance (becomes transparent with the appearance of the color of the base), and part retains its original (opaque) state, which can lead to an unreliable conclusion about the localization of the registered overheating. The base of the thermal indicator device and the thermosensitive layer itself must have a minimum thickness to ensure rapid heating of the indicator layer and change its appearance. This is necessary to register short-term emergency heating caused, for example, by starting currents or the passage of short circuit currents, excessive starting load of motors, cold running, switching or other processes. In addition, a minimum thickness of the thermal indicator sticker is necessary to ensure the necessary heat removal from the controlled surface. Otherwise, installing a temperature indicator will lead to an additional increase in the temperature of the controlled element and an increase in the rate of development of the defect.

Among the solutions known from the prior art, one can highlight devices for visually recording the fact of local overheating of the surface of equipment elements, made in the form of a sticker with a flexible base with a thickness of no more than 1 mm and a response speed of a heat-sensitive composition of less than 5 seconds when heated above a threshold temperature [RU 2022113312, publication date 05/18/2022]. At the same time, the time for registering overheating when the devices quickly heat up to a temperature 5°C higher than the recorded one is less than 5 seconds, which ensures the indication of defective components even during short-term overheating under conditions of peak loads of the controlled components.

However, despite the advantages of thermal indicator stickers described above, their main disadvantage is the difficulty of installation on the wires of electrical panels. Existing regulatory requirements allow for compact (close) arrangement of wires inside electrical panels, especially near contact connections. It is not always possible to wrap an adhesive thermal indicator sticker around the mounted wire. Mechanical impact on the wires when installing the sticker can lead to deterioration in the quality of the contact due to loosening of the contact connection or partial removal of the wire from the terminal under the influence of the applied force. The consequence of this will be a decrease in reliability and an increase in the risk of fire. Separately, it should be noted that winding thermal indicator stickers onto a live wire (without disconnecting from the network) can pose a danger to the installer. When winding a thermal indicator sticker onto a wire, it is not always possible to predict in advance the final location of the thermally sensitive elements. Displacement of indicator points can lead to reduced visibility of the response during inspections, missed defects and reduced reliability. If the thermal indicator sticker is not properly attached to the surface of the wire, peeling or a decrease in the tightness of the sticker may occur. Peeling and loss of functional properties of thermal indicator stickers can also occur when the linear dimensions of the controlled surface change, including due to thermal expansion of the surface material when it is heated by electric current. This is especially true in distribution networks, the load of which varies significantly throughout the day.

Reliability of fastening and safety of operation of thermal indicator stickers is directly related to the strength of adhesion of the sticker to the surface on which they are installed. Adhesion is ensured by the quality of the adhesive layer, the material from which the surface is made, as well as the presence of contaminants or special coatings on it. In some cases, the materials from which wires or other elements are made have special anti-adhesive coatings on which it is impossible to reliably attach thermal indicator stickers. Some difficulties may be associated with the adhesive layer. It may lose its properties over time, and adhesion may deteriorate significantly with increasing temperature. Moreover, the glue itself can melt, leak, get inside the terminal and create an insulating layer between the contact and the terminal, and thereby accelerate the development of the defect. Finally, the use of an indicator with an adhesive layer significantly complicates the process of dismantling a triggered thermal indicator, or a thermal indicator beyond its service life, as well as if repair work is necessary.

These disadvantages can be eliminated by using a device for monitoring overheating of electrical equipment elements, which is a clip made of thermochromic material that irreversibly changes its color when heated above a threshold temperature, which is installed, in particular, on electrical wires [https://iriss.com/ safe-connect-thermochromic-solution/therm series/]. The clip material contains 5-10% thermochromic composition, which provides an irreversible color change, and 90-95% non-halogenated polypropylene. The clip is designed to be installed on the outer insulation of an electrical cable by snapping into place with little force applied and can be safely mounted on controlled electrical components that are live. However, due to the fact that the thermochromic compound is mixed into the material from which the clip is made, in order to complete the color transition upon actuation, the entire clip must be heated to a temperature above the threshold. This will not allow us to detect short-term overheating that occurs during peak load periods and lasts 1-3 seconds, since the time during which the color transition of this clip occurs is up to 20 seconds. Also, due to the fact that the entire clip contains a thermochromic composition evenly distributed throughout its volume, the response range of the clip is 18°C, which does not allow determining the maximum temperature to which the controlled surface was heated with high reliability and distinguishing normal operation from emergency or pre-emergency situations.

The device selected as a prototype [US 2020284665 A1, publication date 09.10.2020], which is an electrical polymer component capable of being mounted on an electrical connection, attached to an electrical cable or wire, or installed on an electrical device, wherein the entire polymer component or part thereof includes a reversible thermochromic composition that changes color when heated above a threshold temperature. The thermochromic composition is a microcapsule pigment that can be added to the polymer particles before forming the desired electrical component or dispersed in the polymer starting material, i.e. the electrical component is made entirely of a material containing a thermochromic composition and is completely painted in a color corresponding to this composition. Accordingly, when the threshold temperature at which the thermochromic composition is triggered is exceeded, the entire electrical component changes color, and when cooled to a temperature below the threshold, the color of the entire component returns to its original color. As stated above, uniform distribution of the thermochromic composition throughout the entire volume of the clip material leads to an increase in the time of full response due to the need to completely warm up the entire device above the threshold temperature to ensure a color transition. For the same reason, the temperature range also increases (in other words, the accuracy of determining the maximum temperature to which the controlled surface was heated) decreases, in which a complete change in the color of the device occurs, which does not allow the use of the described clip for recording short-term overheating to a temperature equal to or slightly exceeding threshold value.

The polymer body of the prototype device is made of polyamides, due to which it is an insulator, has low thermal conductivity and high elasticity. Low thermal conductivity, on the one hand, leads to a partial change in the color of the thermochromic composition only in those places that are in direct contact with the heated surface, while maintaining the original appearance of some parts of the device (for example, fasteners that are removed from the controlled surface). On the other hand, low thermal conductivity leads to an increase in color transition time, since the front surface of the device will warm up significantly longer than the internal surface in contact with the controlled element. As a result, short-term heating will only lead to a change in the color of only the inner surface of the device, and the front side, the appearance of which is recorded by the observer, will remain unchanged, which will not allow recording equipment defects accompanied by such short-term overheating.

Despite the fact that polyamides have low flammability and do not contribute to maintaining an open flame, nevertheless, during a fire they smolder and melt with the formation of drops that can fall on the elements of the controlled equipment, leading to its failure. In addition, polyamide materials are characterized by low stability under the influence of ultraviolet radiation, which significantly reduces the service life of the devices in question, especially in outdoor conditions.

The reversibility of the thermochromic composition used also limits the scope of application of the device described in the prototype, since it detects exceeding the threshold temperature only at the moment of overheating of the controlled components, while during inspections of disconnected equipment or outside peak loads, the temperature of the controlled elements will be within normal limits and overheating will not be registered . For this reason, it is necessary that the device for recording exceeding threshold temperatures not only detects the fact of overheating at the moment the permissible temperatures are exceeded, but also stores information about such overheating until the time of inspection. In addition, the prototype device does not indicate the color transition temperature, which makes it impossible to determine the maximum temperature to which the controlled elements were heated at the time of inspection without the use of additional reference books or technical documentation.

Based on the level of technology we have studied in detail, it follows that, despite the large selection of temperature indicators, different both in the mechanism of action and in design, there is a need for devices that are convenient and safe for installation and operation for recording the excess of the threshold temperature of electrical wires, having:

high accuracy and response speed,

irreversibility of operation,

low flammability and flammability,

high electrical strength and dielectric properties,

having flexibility, strength and the ability to securely attach for a tight fit to various surfaces.

In this case, the principle of operation of such indicators should be based on the melting of a heat-sensitive component, providing:

preservation of the original state at a temperature slightly lower than the threshold,

independence of response temperature from exposure time,

no premature triggering.

The utility model is aimed at creating a safe, convenient and easy-to-install and operate device for irreversibly registering the fact that a threshold temperature has been exceeded in electrical installations, made in the form of a clip, making it possible to install and replace it without negatively affecting electrical equipment.

Terms and definitions used in this utility model

By “clip” we mean an element made in the form of a three-dimensional figure with a through internal cavity, preferably round in cross-section, in which a cut is made that allows the clip to be installed on cylindrical or other objects with a round cross-section, without the use of additional fasteners. In relation to the present utility model, a clip is understood as a product with a cut intended for placement on electrical wires, the fixation of which occurs due to elastic properties, and installation or removal from the wire can occur by snapping the clip onto the wire, without the stage of threading the wire through the clip.

“Thermal indicator clip” is a device made in the form of a clip and with the ability to register the excess of the element on which it is installed, a given threshold temperature due to heat-sensitive elements located on the clip, built into it or included in the material from which it is made.

The term “temperature-sensitive material” means a material that becomes more transparent to at least a portion of visible light relative to its original state when heated above a threshold temperature, and does not return to its original state upon subsequent cooling. The temperature-sensitive material may consist, for example, of an individual organic compound or a salt of an organic acid, which undergoes a phase transition when a threshold temperature is reached, or of a mixture of substances. In addition, the heat-sensitive material may additionally include a binder, such as organic resins, for better adhesion of the heat-sensitive material on a flexible base, and other additives.

In this utility model, the term “glazing” is used to denote the process of formation of a uniform layer of one thermodynamic phase around a particle of another thermodynamic phase.

The term “threshold temperature” or “threshold temperature” refers to the numerical value of temperature at which an irreversible change in the properties of a heat-sensitive material occurs. In the claimed utility model, the accuracy of recording exceeding the threshold temperature is 5°C.

The term “accuracy of recording exceeding the threshold temperature” means the following:

1. Until the device reaches a temperature equal to the threshold temperature of the corresponding heat-sensitive material minus the value of the declared accuracy, there is no change in the transparency of the corresponding heat-sensitive material and the appearance of the device.

2. At a temperature equal to or greater than the threshold temperature of the corresponding temperature sensitive material plus the stated accuracy value, the corresponding temperature sensitive material is transparent and the device takes on a different appearance from the original one.

3. The exact value of the phase transition temperature of the thermosensitive component is within the declared range and is not further established. The accuracy of recording exceeding the threshold temperature determined by this utility model is 5°C.

“Phase transition” is the transition of a substance from one thermodynamic phase to another when external conditions change.

In this utility model, the term “actuation” is applied to a heat-sensitive material that has undergone a phase transition with an increase in transparency. A device in which the temperature-sensitive material has changed transparency is designated as “triggered.”

“Defect” is the non-compliance of an object with the requirements established by the documentation for at least one indicator.

“Fire resistance” refers to the ability of a material to resist combustion under the influence of an ignition source.

The term “electric strength” defines the ability of a given device to withstand electrical voltage applied to it. In other words, electrical strength is the minimum electric field strength at which breakdown of the device occurs.

The term “dielectric” means the property of a given device to withstand an electrical voltage applied to it, while the minimum electric field strength at which breakdown of the device occurs exceeds the electrical strength of air.

The term “elasticity” reveals the ability of a solid material to return to its original shape during elastic deformation, i.e. an elastic material is deformed after an external force is applied to it, but restores its original shape and size after the influence of this force ceases.

The term “fast heating” corresponds to heating the surface with the device installed on it at a rate of at least 1°C/s. The absolute value was selected expertly based on the heating rate of electrical conductors when emergency conditions, short circuit currents or inrush currents occur.

The term “transparent” refers to the property of a material to transmit more than 90% of the light incident on it. The term “opaque” characterizes a material that transmits no more than 50% of the light incident on it.

The term “elasticity” reveals the ability of a material, when bent around a cylindrical surface, to repeat its shape without loss of functional properties. The term “elasticity in tension/compression” refers to the preservation of the functional properties of a material when a force is applied in any direction in a plane parallel to the plane of location of the material, as well as after the removal of this force.

The term “flexible base” refers to materials that have the ability to return to their original shape when bent.

The term elastic base and elastic protective film characterize the base or protective film material, which refers to materials that have the ability to change their shape without breaking under external influence.

The term “surface of complex geometry” means any curved surface containing bends, kinks and other nonlinear elements with a minimum radius of curvature of 2 mm. In this utility model, a cylindrical surface with longitudinal waves with a radius of curvature of an individual bending element R=2 mm is considered as a model surface of complex geometry.

The term “radius of curvature” of curved and cylindrical surfaces refers to the maximum radius of the circular arc that best fits with these surfaces. In relation to this utility model, “small radius of curvature” means a radius of curvature of 2 mm or more.

The term “cylindrical surface” refers to a developable closed or open ruled surface formed by the parallel movement of a straight line along some curved guide.

By “elongation to break” is meant the numerical value of the elongation of a product or its parts during stretching, above which its physical integrity is violated and rupture occurs. The value is expressed as a percentage, indicating how much the linear dimensions of the material increase when it is stretched relative to the corresponding original dimensions.

“Microstructure” is the spatial arrangement of particles or individual phases of a material, reflecting the shapes and orientation of the particles that make up the material. Unlike chemical structure or nanoparticles, microstructure determines only the physical, optical and mechanical properties of the material, but does not affect the chemical properties of the substances that make up the microstructure. In relation to this utility model, an “irreversible change in microstructure” is understood as an irreversible change in the physical, optical or mechanical properties of a material relative to the initial state, accompanied by a change in its microstructure, that is, the spatial arrangement of particles or individual phases of the material, their size or shape, up to the complete fusion of particles and formation of a single phase.

The “surface profile of maximum temperatures” is understood as an image showing the distribution of maximum values of temperature fields on a controlled surface and allowing one to determine areas of the surface that were heated above threshold temperatures over a given time.

The term “solid phase” reveals the structure of a material containing particles of a solid substance of arbitrary shape, each of which has at least one point, face or edge in contact with an adjacent particle and interconnected in such a way that each element of the solid phase can be connected to another its element is a single broken line, each point of which is located inside this phase. Depending on the shape and particle size of the solid, the continuous solid phase may have a cellular, granular, fibrous, crystalline or scaly structure.

The term “continuous gas phase” characterizes the relative arrangement of voids and means that the voids are predominantly “non-isolated” (“connected”) and communicate with each other through holes, pores or channels. In relation to the present application, a predominantly continuous gas phase is understood to mean an arrangement of voids within a temperature-sensitive material in which the volume of voids interconnected and forming a continuous gas phase exceeds the volume of isolated voids.

The term “substance that causes a change in the transparency of a thermosensitive material when heated above a threshold temperature” means an individual substance included in the composition of a thermosensitive material, having a phase transition temperature near the threshold temperature, the presence of which causes a change in the appearance of the thermal indicator when the threshold temperature is reached, and the removal of which from the thermosensitive material material leads to the loss of properties of an irreversible change in transparency when a threshold temperature is reached.

Essence of a utility model

This utility model was created to improve the safety of operation of electrical equipment, using a simple, safe and easy-to-install device, made in the form of a clip, designed for mounting on wires or other elements of electrical equipment, which allows you to quickly, reliably and reliably identify defects associated with excessive heating, by irreversibly registering the fact that a controlled element of electrical equipment exceeds a specified threshold temperature.

The objective of this utility model is to create such a device in the form of a clip.

The technical result of the claimed utility model is to increase the reliability and safety of operation of contact connections of electrical equipment, due to the irreversible registration of heating using a self-extinguishing thermal indicator clip, which makes it possible to install and replace it without negatively affecting the electrical equipment.

The specified technical result is achieved due to the irreversible registration of the fact that an element of electrical equipment exceeds a given threshold temperature, a device made of a material with self-extinguishing properties, which is convenient, reliable and safe to install, replace and operate, including on contact connections.

The technical result is achieved due to a device for recording the excess of a threshold temperature, configured to be installed on wires, including a base made of an elastic material, opaque to at least part of visible light, including halogen-containing polymers, made in the form of a clip, partially coated on the front side with a heat-sensitive material, irreversibly changing transparency relative to the initial state when heated above a threshold temperature.

Making the base of a temperature-sensitive indicator in the form of a clip has a number of advantages:

allows you to simply, reliably and safely install a temperature indicator without the use of adhesives, as well as replace it with electrical panel wires, including in hard-to-reach places of the electrical installation, with close proximity of controlled elements of electrical equipment;

the thermal indicator layer adheres tightly and evenly to the controlled surface of the electrical equipment;

reliable fastening under the influence of the following factors: fluctuations in ambient temperature, mechanical stress, thermal expansion of the material of the controlled element of electrical equipment, etc.

The proposed device is made in the form of a clip to ensure its convenient, reliable and safe installation, replacement or dismantling of wires and other elements of electrical equipment, as well as tight fit of the temperature-sensitive layer to the controlled elements for reliable registration of the fact of exceeding the threshold temperature throughout the entire service life

The factors listed above ensure reliable, safe and reliable operation of the device and registration of exceeding the specified threshold temperature by controlled elements of electrical equipment throughout its entire service life.

The base material is selected in such a way as to ensure the simultaneous fulfillment of the following criteria:

elasticity, flexibility and elasticity necessary for a tight fit of the device to the surfaces of controlled elements of electrical equipment, which often have complex geometry, while maintaining the ability to register overheating with the stated accuracy;

ensuring the necessary pressing and fixation of the clip for reliable fixation of the device while maintaining a tight fit, including during vibration, under the influence of various environmental factors, mechanical stress, thermal expansion and other deformations of the material of the controlled element of electrical equipment;

ensuring the necessary adhesion to the protective film and heat-sensitive material;

resistance to ignition and ability to self-extinguish when exposed to an open flame. Ignition of the device, in turn, can lead to a fire in the electrical installation or an electric arc;

thermal conductivity sufficient to ensure rapid heating of the device and the heat-sensitive layer to a threshold temperature for reliable and reliable recording of short-term overheating, as well as heat removal from heating wires and contact connections;

low electrical conductivity, allowing the device to be installed not only on electrical equipment elements coated with insulating materials, but also on contact connections without insulation. High electrical strength and dielectric properties of the device as a whole are necessary to ensure safe use in electrical installations, motors or various electrical mechanisms. The lack of conductivity and the high value of the breakdown voltage makes it possible to prevent the failure of electrical circuits, the occurrence of a short circuit or the ignition of an electric arc when the clip comes into contact with open conductive elements;

preservation of the original shape when heated, i.e. the materials of the base and protective film should not melt to their current state when heated to high temperatures, in order to avoid the clip separating from the wire, the softened material flowing down and getting on the elements of electrical equipment.

ensuring stable attachment to the controlled element over a wide temperature range (decomposition temperature, preferably above 150°C).

The most suitable materials for this purpose are halogen-containing polymers. In particular cases, polymers containing the structural unit -CH ₂ CHCI-, preferably polyvinyl chloride, preferably cast polyvinyl chloride, can be used. Polymer materials containing halogen atoms in their structure have some of the highest flexibility and elasticity among known polymers. The introduction of halogen atoms into monomers used as feedstock for polymerization breaks their symmetry and creates many chiral centers in the polymer. Polymerization or polycondensation of such monomers, both with each other and with other halogen-containing or non-halogen-containing monomers, leads to the formation of polymer chains with a large number of stereocenters. Regular polymers derived from non-halogenated monomers without chiral centers tend to form crystalline structures, which reduces their elasticity, while the large number of diastereomers resulting from halogenation of monomers imparts stereochemical disorder to halogenated polymers, which prevents crystallization. Thus, halogen-containing polymer materials have high elasticity and flexibility due to the peculiarities of their chemical structure due to the presence of halogen atoms in the structure of polymers. In addition, halogen-containing materials have good adhesion and low flammability, which ensures the safe operation of the claimed device and the electrical equipment on which it is placed.

By making the device in the form of a clip made of halogen-containing polymers, its elasticity is ensured, which is necessary to ensure easy installation of the thermal indicator without applying excessive force to the controlled elements of electrical equipment, as disclosed in the prior art. For example, in the case of contact connections, the occurrence of defects in most cases is associated with the loosening of these connections. To prevent such defects, the installation of thermal indicator devices on contact connections should not involve disassembling this connection (for example, to install a tip on operating equipment), since the procedure for disassembling and subsequent assembly of the connection may lead to the occurrence or development of a defect. Also, excessive force should not be applied to the contact connection, contributing to its loosening, which can be exerted, for example, when placing a sticker with a uniform and tight fit to the controlled surface, it is necessary to apply pressure to adhere it. Thus, the choice of both the shape and material of the base of the claimed device is based on the need to ensure reliable fastening of the thermal indicator to the wires and contact connections of electrical equipment to increase the fire safety of the operation of this electrical equipment.

The claimed device also has the properties of irreversible heat-sensitive indicators, the principle of which is the melting of a heat-sensitive material, accompanied by a change in transparency relative to the initial state when heated above a threshold temperature. Using this overheating detection principle ensures fast, reliable and reliable detection of defects associated with excessive heating.

Electrical equipment elements, in particular, polymer-insulated electrical wires located inside electrical panels, were selected as the object of control for this utility model. This is due to several reasons. Firstly, the reliability and reliability of the functioning of electrical installations is an important and integral factor in ensuring the safety and reliability of the operation of almost all types of production, social facilities, transport, urban infrastructure, etc. Secondly, electrical installations are a source of increased fire danger. Fires due to violations of the operating rules of electrical equipment or poor-quality installation take first place after careless handling of fire. Thirdly, in most cases, traditional methods of thermal monitoring, for example, thermal imaging inspection in electrical panels, are ineffective due to the difficulty of creating a maximum load mode or measuring the load current in each individual wire. However, to reduce the fire hazard of electrical installations, especially in places with a high constant fire load, it is necessary to detect overheating of individual elements of electrical equipment, in particular electrical wires, at the initial stage of defect development, preventing the occurrence of emergency situations. Thus, the purpose of creating the claimed device was to provide reliable and reliable recording of overheating of electrical equipment elements, including in facilities with a high fire load.

The use of a heat-sensitive material based on the melting of a heat-sensitive material, accompanied by a change in transparency relative to the initial state when heated to a threshold temperature, provides:

irreversibility of the visual trigger effect;

high speed of operation of the device;

preservation of the original state at a temperature slightly lower than the threshold;

the required accuracy of the response temperature, regardless of the time of exposure to temperature.

An information element can be applied to the base, including information about the recorded temperature, for prompt determination during inspections of the numerical value of the threshold temperature that the claimed device registers.

The front surface of the device and the heat-sensitive material can be covered with an elastic protective film that is transparent to at least part of visible light, which additionally protects the heat-sensitive material and the clip itself from external environmental influences, humidity, UV irradiation and mechanical damage, increases the service life of the device and prevents heat-sensitive material from draining during phase transition.

Also, to prevent the flow of molten heat-sensitive material during a phase transition, which can cause emergency situations, a recess can be made in the material from which the base of the device is made to fill it with heat-sensitive material.

Preferably, the device has dielectric properties, preferably having a dielectric strength of at least 5 kV/mm.

The protective film material also preferably includes halogen-containing polymers, advantageously containing a -CH2CHCI- structural unit, advantageously polyvinyl chloride, advantageously cast polyvinyl chloride.

The elastic protective film, transparent to at least a portion of visible light, which may cover the front surface of the device, in particular the heat-sensitive material, is also preferably made of polyvinyl chloride, most preferably cast polyvinyl chloride.

The elastic protective film can be attached to the substrate by fusion (welding), adhesive or other methods.

In particular embodiments of the utility model, to ensure self-extinguishing properties of the base of the device when exposed to an open flame, the base material or coating of the clip may also include a plurality of hermetically sealed pores filled with a fire extinguishing agent or fire retardant, capable of being released from these pores to suppress the resulting fire.

Preferably, the base of the device can be made in the form of a single structure with the ability to be fixed to electrical wires, preferably with a diameter of 1 to 10 mm, without additional elements, and special elements for snapping the device onto electrical wires, preferably with a diameter of 1 to 10 mm, can also be made on the base. 10 mm, which ensures ease of installation and further increases the reliability of mounting the device on electrical equipment.

In preferred embodiments, the heat-sensitive material irreversibly changes transparency when heated within a range of no more than 5°C, preferably no more than 2°C, relative to the threshold temperature indicated on the device.

In some embodiments, the base in the area of the heat-sensitive material is painted black, and when the threshold temperature is reached with the stated accuracy, a visual color transition of the corresponding part of the surface of the device occurs from white to black, that is, the heat-sensitive material in an opaque state is white.

In particular cases, the heat-sensitive material in the initial state has a microstructure that includes a solid phase and voids, forming a continuous gas phase, the share of which is at least 50 vol.%, and is designed to irreversibly change its appearance upon reaching the specified threshold temperature due to destruction microstructure of a thermosensitive material, accompanied by the fusion of particles of solid organic matter, a decrease in the proportion of voids and an increase in its transparency with the appearance of the color of the base (see Fig. 4).

The use of a heat-sensitive material with voids allows you to increase the service life, further increase the reliability of determining overheating due to the impossibility of aggregation of solid particles through the gas phase and eliminate the possibility of the material returning to its original state after operation due to an irreversible change in the microstructure, which also has a positive effect on the safety of operation as a clip , and the equipment itself. When a thermosensitive material containing voids is melted, an irreversible change in the initial microstructure of the material occurs with a decrease in the proportion of voids in it, associated with the fusion of particles of solid organic matter and with a decrease in the area of the solid-gas phase boundaries due to the irreversible release of the gas contained in the voids to the surface and separation of gas and non-gas media. As a result, upon further cooling, the solid organic substance crystallizes without voids, thereby irreversibly changing the transparency (increases relative to the initial state) of the material for at least part of the visible light, creating a visual effect of changing the appearance of the device with high contrast, which ensures high reliability of exceedance registration temperature is higher than the set value. Preferably, the proportion of voids of the thermosensitive material after heating above the corresponding threshold temperature value decreases by at least 2 times relative to the initial state, which further increases the contrast of the color transition of the device when the threshold temperature value is exceeded.

The organic matter of the solid phase of the thermosensitive material can be selected from the group: aliphatic fatty acids containing structural fragments C _n H _(2n+1) with n≥12; salts of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C _n H _(2n+1) cn≥5; amides of fatty aliphatic acids containing structural fragments C _n H _(2n+1 with n≥12; anhydrides of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥10; fatty aliphatic alcohols containing structural fragments C _n H _(2n+1) with n≥14; fatty aliphatic amines containing structural fragments C _n H _(2n+1) with n≥17; nitriles of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥ 19.

The use of organic compounds, which include one or more aliphatic hydrocarbon chains C _n H _(2n+1) with n≥5, as an organic substance of the solid phase of a thermosensitive material; promotes the formation of crystalline packaging, in which elongated structural fragments of linear hydrocarbons are oriented parallel to each other (A.I. Kitaigorodsky, Molecular Crystals, M.: Nauka, 1971). Due to the fact that particles of solid organic matter are formed in the form of fibers, flakes or flat or elongated crystals, that is, they have a two-dimensional structure, the thermosensitive material forms a special microstructure capable of bending and stretching without deformation and loss of functional properties.

Also, the use of solid organic compounds, which include non-polar aliphatic fragments, further increases the electrical strength of the device as a whole, since such fatty aliphatic derivatives have good dielectric properties.

In particular cases, the organic substance of the solid phase of the thermosensitive material is selected from the group: 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.

In particular cases, the microstructure of a thermosensitive material additionally contains a polymer binder that is transparent to at least part of visible light, the phase transition temperature of which is higher than the phase transition temperature of solid organic matter. In this case, the thermosensitive material contains phase boundaries “solid-transparent solid-gas”; during melting, an irreversible change in the microstructure of the material also occurs, as a result of which the number of voids decreases relative to the initial state due to the release of the gas contained in them to the surface of the material and gas delamination occurs and non-gas environments, as a result of which there is a decrease in the contact area of the solid phase and voids, i.e. reducing the area of phase boundaries.

Preferably, the polymeric binder is present in the temperature-sensitive material in an amount of 1-30 wt.%. In particular cases, a polymer binder coats each individual structural particle of solid organic matter, providing it with “glazing.” The binder is selected to ensure wettability, but not dissolution, of the solid organic matter particles in the polymer binder. Due to this, during the “glazing” of grains, crystals, fibers, flakes or conglomerates of these particles, additional capture of gas occurs, in the environment of which a thermosensitive material is formed, and its distribution between the “glazed” binder particles of solid organic matter.

In preferred embodiments, the heat-sensitive material is configured to change transparency when heated above a threshold temperature in no more than 5 seconds, preferably no more than 2 seconds. This is due to the fact that the thickness of the layer of heat-sensitive material and its structure, together with the thickness of the base of the device, is selected in such a way as to allow heating of the heat-sensitive material when short-term overheating occurs during peak load periods and completely transforming it into a melt with an “opaque-transparent” color transition in for no more than 5 seconds, preferably no more than 2 seconds, and also provides the necessary heat transfer during air cooling of operating devices. In particular, the thickness of the base in the area of the heat-sensitive material is not more than 3 mm, preferably not more than 1 mm.

The threshold temperature can be selected from the range of 50-210°C, preferably 50°C, 55°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C. Based on the threshold temperature value selected for registration, the applied heat-sensitive material is selected in such a way that the solid organic substance included in its composition has a melting point that differs from the threshold temperature by no more than 5°C.

To facilitate visual detection of exceeding the threshold temperature, the surface area of the base coated with the heat-sensitive material is preferably at least 3 mm ² , preferably at least 10 mm ² .

In private embodiments of the device, an information element can be applied to the base, which includes information for marking elements of electrical equipment or color marking of phases. In particular, the information element applied to the front surface of its base may contain an inscription containing color, letter, numeric or alphanumeric marking information. In one case, the information element on the base contains information about the end of life date of the device. Also, the base may have a color that corresponds to the established rules for marking elements of electrical equipment. The features listed above serve to give the device for recording the excess of a threshold temperature the properties of electrical equipment marking elements, which also additionally ensures the safety of operation of the equipment on which such devices are placed, due to the following. In the case of contact connections, wires or electrical components, we are talking about small surfaces that, on the one hand, require marking, and on the other hand, temperature control. However, the use of marking devices and devices for recording temperature rises separately is often not possible due to insufficient space on the controlled surface. Using only a temperature indication device without markings can lead to incorrect identification of the defective unit, as well as to an increase in detection time. Thus, a device that combines the properties of a marking device, as well as the properties of temperature indicators, will have a positive impact on the safety of operation of electrical equipment.

To increase the visibility of both the device itself and the fact of its operation, on equipment elements, including those difficult to inspect due to the large size of the installations, the location of the installations in the open air or due to inspection in bad weather conditions and in conditions of insufficient visibility, in the dark time of day using a flashlight, as well as for inspecting equipment without artificial lighting and windows, and, as a result, further increasing the safety of equipment operation, the base may have reflective properties or can be painted using a substance with luminescent properties. Ensuring visibility, as well as reliability of detection of local heating of elements of electrical equipment, is achieved using a variant of the device with a surface area of the base coated with a heat-sensitive material, from 3 to 97% of the area of the front surface of the base, preferably, at least 30% of the area of the front surface of the base.

In particular cases, the base can be colored using a substance designed to irreversibly change color when heated.

The use of substances when painting the base that are capable of irreversibly changing color when heated to a temperature below the threshold temperature of the base heat-sensitive material, for example, by 10-30°C, makes it possible to inform personnel about the risk of an emergency defect occurring in the future, and thereby provides the opportunity its prevention, with proper response from the personnel responsible for this equipment. Thus, the activation of such a substance, in the absence of activation of the main heat-sensitive material, indicates the presence of overheating of the equipment, which has not reached the maximum permissible values corresponding to the threshold temperature of the main heat-sensitive material, and the need to inspect it in order to identify and eliminate problems that could subsequently lead to development of an already emergency defect. Thus, the presence of a substance capable of irreversibly changing color when heated to a temperature below the threshold temperature of the main heat-sensitive material, in particular by 10-30°C, further increases the operational safety of both the claimed device and the equipment as a whole.

Also, the base or some part thereof may be colored using a substance capable of reversibly changing color when heated. For example, a layer of heat-sensitive paint having the above properties can be applied to the front surface.

The presence of a substance capable of reversibly changing color when heated makes it possible to inform personnel not only about exceeding a threshold temperature in the past, but also about overheating at the time of inspection. The activation of such a substance at the time of inspection indicates that the equipment is in emergency mode at the current moment and can be a source of increased danger. Thus, the presence of a substance capable of reversibly changing color when heated further increases the safety of operation of both the claimed device and the equipment as a whole.

Brief description of drawings

The utility model will be more understandable from the description, which is not restrictive and is given with reference to the accompanying drawings, which show:

Fig. 1 - A device for recording the excess of a threshold temperature, made in the form of a clip with additional fastening elements, with a recess in the base material filled with heat-sensitive material, and with additional coloring in the area of the heat-sensitive material (sectional top view).

Fig. 2 - Frontal view of a device for recording exceeding a threshold temperature, made in the form of a clip, the base of which has luminescent properties, with additional coloring in the area of the heat-sensitive material and an information element, including the numerical value of the threshold temperature and located under the heat-sensitive material: 2a - initial view of the device, 26 - activated device after exceeding the threshold temperature, 2c - type of device after further cooling to room temperature.

Fig. 3 - Three-dimensional model of a device for recording exceeding a threshold temperature, made in the form of a clip with additional fastening elements and an information element, including the numerical value of the threshold temperature and a temperature-sensitive material located nearby.

Fig. 4 - A device for recording exceeding a threshold temperature, made in the form of a clip with additional fastening elements, additional coloring in the area of the heat-sensitive material and a protective film covering the heat-sensitive material (sectional top view).

Fig. 5 - Three-dimensional model of a device for recording exceeding a threshold temperature, made in the form of a clip with additional fastening elements, the base of which is painted in the colors of the phase markings.

Fig. 6 - Microstructure of a thermosensitive material with particles of organic matter in the form of flakes and their conglomerates, binder and voids before actuation (a) and after actuation (b).

Fig. 7 - Frontal view of a device for recording exceeding a threshold temperature, made in the form of a clip: (a) - initial view of the device, (b) - partially activated device after spot heating of the controlled surface above the threshold temperature value with a change in transparency of only that area of the thermosensitive material that was subjected to heating above a threshold temperature, while maintaining an opaque region of the material in its remaining zone, which was not subject to heating.

Fig. 8 - Layered structure of a device for recording the excess of a threshold temperature, made in the form of a clip, in the area of a heat-sensitive material: (a) - with a sealed transparent protective layer, (b) - with a transparent protective layer, in which a gap is made between the protective layer and the base, (c) - with a transparent protective layer in which micro-holes are made.

In fig. Figure 1 shows a cross-section of a device for recording the excess of a threshold temperature, which is an opaque base 1, made in the form of a clip, containing additional fastening elements 6.

On the front side of the base material there is a recess filled with heat-sensitive material 2. In FIG. 1 shows a particular version of the device, in which the base 1 is yellow for marking the phases of electrical equipment and is painted black 3 in the area of the heat-sensitive material.

In fig. Figure 2 shows the front side of the device for recording the excess of a threshold temperature, which is an opaque base 1, made in the form of a clip and having luminescent properties, and a thermosensitive material 2 applied to its front side: in the initial state before heating (a), after heating to the threshold temperature heat-sensitive material (b) and after further cooling to room temperature (c). In fig. 2 shows a particular version of the device with an information element 4, including a numerical value of the threshold temperature and located under the heat-sensitive material, the base 1 is painted black in the area of the heat-sensitive material.

In fig. Figure 3 shows a three-dimensional model of a device for recording exceeding a threshold temperature, which is an opaque base 1, made in the form of a clip, containing additional fastening elements 6, and a thermosensitive material 2 applied to its front side. FIG. 3 shows a particular version of the device with an inscription indicating the recorded threshold temperature 4, located on the base next to the heat-sensitive material, and the base 1 is yellow.

In fig. Figure 4 shows a cross-section of a device for recording exceeding a threshold temperature, which is an opaque base 1, made in the form of a clip, containing additional fastening elements 6, on the front surface of which a heat-sensitive material 2 is applied, covered with a transparent elastic protective layer 5. FIG. 4 shows a particular version of the device, in which the base 1 is yellow and painted black 3 in the area of the heat-sensitive material.

In fig. Figure 5 shows a three-dimensional model of a device for recording exceeding a threshold temperature, which is an opaque base 1, made in the form of a clip, containing additional fastening elements 6, and a thermosensitive material 2 applied to its front side. FIG. Figure 5 shows a particular version of the device with base 1 painted red, corresponding to the phase markings.

In fig. Figure 6 shows the microstructure of a heat-sensitive material 2 with particles of organic matter 7, made in the form of flakes and their conglomerates, a binder 10 and voids 8 before heating (a) and the microstructure of a heat-sensitive material 2 with a reduced proportion of voids 8 and with an increased apparent density and with particles 7, have undergone fusion and lost their original shape after heating above the threshold temperature (b).

In fig. Figure 7 shows the front side of the device for recording the excess of a threshold temperature, which is an opaque base 1, made in the form of a clip, and a thermosensitive material 2 applied to its front side: before heating (a) and after spot heating (b) of the controlled surface, as a result of which the change in transparency occurred only in that area 12 of the heat-sensitive material 2, which was subject to heating above the threshold temperature, while maintaining the original appearance of the rest of the area of the heat-sensitive material 2.

Figure 8 shows the layered structure of a device for recording exceeding a threshold temperature, the base 1 of which is made in the form of a clip, onto which a heat-sensitive material 2 is applied, covered with a transparent protective layer 4, which: (a) fits tightly to the base and material and ensures the tightness of the device and the ability to maintain subatmospheric pressure; (b) fits tightly to the base and material and has a gap 11a between the protective layer and the base; (c) fits tightly to the base and material and has micro-holes 116 on its front surface.

Implementation of a utility model

Wasp technology for manufacturing the device.

As the basis 1 of the claimed device, halogen-containing polymer materials were used, containing, in particular, polyvinyl chloride (PVC), cast PVC. These materials have the necessary strength and flexibility, give the device fire resistance and have an electrical strength of at least 5 kV/mm. The base 1 is made in the form of a clip, providing simple, safe and convenient installation of the device on electrical wires, preferably with a diameter of 1 to 10 mm, or other elements of electrical equipment, made in the form of a single structure with the possibility of fixing on controlled objects without additional elements or including elements 6 for snapping the device onto controlled objects. Next, options for manufacturing and using the claimed device will be considered using the example of a clip without additional elements, the base of which is made of PVC.

The thickness of the base may be uneven and depends on the design of the clip, however, in the area of the heat-sensitive material, the thickness of the base is preferably no more than 3 mm, most preferably no more than 1 mm, which allows the transparency of the heat-sensitive material to change when heated to a temperature above the threshold for no more than 5 seconds, preferably no more than 2 seconds, which also increases the safety of operation of the controlled equipment, since it allows the heat-sensitive material to be heated in the event of short-term overheating during peak load periods and completely transform it into a melt with an “opaque-transparent” color transition and the development of the base color under it for no more than 5 seconds, preferably no more than 2 seconds, and also provides the necessary heat transfer.

In some embodiments, the substrate may have reflective properties or may be colored using a substance that has luminescent properties to increase the visibility of both the device itself and the fact of its operation, which further increases the safety of operation of the equipment. Also, in special cases, the base can be painted to allow the claimed clip to be used for color marking of phases of electrical equipment.

In particular cases, the base can be colored using a substance designed to irreversibly change color when heated. The presence of an additional substance capable of irreversibly changing color when heated to a temperature below the threshold temperature of the main heat-sensitive material, in particular by 10-30°C, makes it possible to detect overheating of equipment that has not reached the maximum permissible values, and, as a result, to ensure the prevention occurrence of an emergency defect.

Also, the base can be colored using a substance capable of reversibly changing color when heated. For example, a layer of heat-sensitive paint having the above properties can be applied to the front surface. The presence of a substance capable of reversibly changing color when heated makes it possible to inform personnel not only about exceeding a threshold temperature in the past, but also about overheating at the time of inspection.

Halogen-containing polymers, in particular PVC films, or polyurethane films modified with 15% trichloroisopropyl phosphate, can also be used as an elastic protective film. However, it must be taken into account that if they are used for protective films, they must be transparent to at least part of visible light.

Preparation of heat-sensitive material.

Preferably, the solid phase of the thermosensitive material includes an organic substance containing a structural fragment C _n H _(2n+1), where n≥5; aliphatic fatty acids containing a structural fragment C _n H _(2n+1) with n≥12; salts of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥12; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C _n H _(2n+1) with n≥12; amides of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥12; aliphatic fatty acid anhydrides containing structural fragments C _n H _(2n+1) with n≥10; fatty aliphatic alcohols containing structural fragments C _n H _(2n+1) with n≥14; fatty aliphatic amines containing structural fragments C _n H _(2n+1) with n≥17; nitriles of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥19, for example, palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearic alcohol, cetyl alcohol, polyethylene, wax, paraffin, saturated salts fatty carboxylic acids of rare earth metals, in particular lanthanum, yttrium, ytterbium, scandium, or a mixture thereof with a melting point differing from the corresponding threshold temperatures indicated on the device by no more than 5°C, were crushed to a size of 2-3 microns in a ball mill, successively added a diluent or a solution of a binder in a diluent and stirred until smooth. As a diluent, for example, water, methanol, ethanol, isopropanol, ethylene glycol, ethylene glycol monomethyl ether, acetonitrile, etc., or mixtures thereof can be used. The suspension was used for application immediately after receipt.

In preferred embodiments, the content of the thermosensitive material in the solid phase, including organic matter, is at least 50 wt.%, most preferably, at least 70 wt.%.

The organic substance is selected in such a way that when a threshold temperature is reached 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.

In various embodiments, a substance that causes a change in the transparency of the heat-sensitive material when heated above the threshold temperature and is part of the heat-sensitive material is selected in such a way that the threshold temperature can be selected from the range from 50°C to 210°C, in particular cases, the temperature threshold selected from the group: 50°С, 55°С, 60°С, 70°С, 80°С, 90°С, 100°С, 110°С, 120°С, 130°С, 140°С, 150° WITH.

To produce a heat-sensitive material, the solid phase, including a substance that causes a change in the transparency of the heat-sensitive material when heated above a threshold temperature, is ground in a ball mill to a size of 2-3 microns, the liquid phase, represented by water or an organic solvent with a boiling point of less than 180°C, is sequentially added, and the resulting suspension is stirred, while preferably, during this period, periodic dispersion of the mixture with air access is ensured until a constant density of the mixture is obtained. The liquid phase is preferably water or an organic solvent in which the solubility of the solid phase of the thermosensitive material does not exceed 10 g/kg.

In preferred embodiments of the invention, the liquid phase is added in an amount of from 50 vol.% to 90 vol.%.

The difference in density between the liquid phase and the solid phase is preferably less than 0.2 g/cm ³ . For this purpose, the liquid phase can be selected from the group: isopropanol, water, methanol, 1-propanol, isobutanol, ethylene glycol monomethyl ether, 1-butanol, acetonitrile, acetic acid, hexane, heptane, 1,1,1-trifluoroethanol, 1, 1,1,3,3,3-hexafluoroisopropanol, dimethylformamide, ethanol, butyl acetate, water, acetone, toluene, or mixtures thereof, but are not limited to.

With this production method, the resulting thermosensitive material is preferably present in two continuous phases: solid and gas. In this case, the solid phase is represented by particles predominantly oriented parallel to the surface of the base.

In this case, the resulting thermosensitive material in the initial state is opaque to at least part of visible light and in the initial state includes a solid phase and voids filled with a gas phase, the proportion of which in the initial state is at least 50 vol.%, and when heated above the corresponding threshold temperature value, an irreversible change in the microstructure of the corresponding heat-sensitive material occurs, accompanied by the fusion of particles of solid organic matter, a decrease in the proportion of voids, preferably 2 or more times, and an increase in its transparency with the appearance of the color of the base, and with subsequent cooling to 20 ° C and holding at this temperature for at least one month, preferably one year or more, the transparency of the heat-sensitive material does not return to its original values.

Depending on the nature of the solid phase and the substance causing the change in the transparency of the thermosensitive material when heated above a threshold temperature, the type of the resulting solid phase particles can be grains, crystals, fibers, flakes or conglomerates of these particles.

In particular cases, the heat-sensitive material additionally contains a polymer binder that is transparent to at least part of visible light, the phase transition temperature of which is higher than the phase transition temperature of the organic substance of the solid phase. In this case, the ground solid phase 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 utility model, the binder is present in the resulting heat-sensitive material in an amount of 1-30 wt.%, to ensure the effect of glazing particles of solid organic matter.

In particular cases, the transparent polymer binder is selected from phenol-formaldehyde resin, butyl methacrylic resin, melamine formaldehyde resin, polyvinyl butyral, polybutyl methacrylate, polyisobutyl methacrylate, polybutyl acrylate, phenoxy resin, polystyrene-acrylic emulsion, polyolefin, polystyrene, polyacrylate, polyethersulfone, polyethyl ene, polypropylene, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene , polyethersulfone, polyisoprene, polypropylene, polybutadiene, polyisobutylene, polyvinyl acetate, polymethacrylate, ethylcellulose, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polycaprolactone, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, polyvinylidene fluoride, polyester, polyester hydroxyethylcellulose, methylcellulose, ethylcellulose, nitrocellulose, carboxymethylcellulose, gelatin, agar-agar, casein, gum arabic, polyvinyl alcohol, polyethylene oxide or mixtures thereof.

In some cases, an inscription with information about the threshold temperature was placed on the front side of the device. In special cases, in addition to the threshold temperature, information about the expiration date was also included. In one embodiment, a drawing can be applied to the surface of the base, intended for marking phases or components of electrical equipment, containing graphic, numerical or text information.

In general, the process of manufacturing a device includes the stages of applying one or more layers of a suspension of solid phase particles in a liquid phase to individual areas of an opaque base, removing the liquid phase from the applied layers of the suspension, and also covering the front surface of the workpiece with a transparent protective layer.

To obtain a microstructure of a deposited heat-sensitive material, including a solid phase and voids filled with a gas phase, the share of which in the initial state is at least 50 vol.%, and providing an irreversible change in appearance when a threshold temperature is reached, which is accompanied by the melting of particles of the solid phase, a decrease in the proportion voids and increasing its transparency with the appearance of the color of the base, you can use, in particular, the following techniques at the previously disclosed stages of the method:

at least one of the above stages of the method (applying a suspension of particles of solid organic matter in the liquid phase, removing the liquid phase from the applied layers of the suspension, covering the front surface of the workpiece with a transparent protective layer) is carried out at a pressure below atmospheric.

at least 3 cycles of applying layers of a suspension of solid phase particles in the liquid phase and removing the liquid phase from the applied layers of this suspension are carried out, while applying a suspension of solid phase particles in the liquid phase is carried out by a method selected from the group: screen printing, flexographic printing, tampon printing , silk-screen printing, with obtaining a microstructure of a heat-sensitive material, the particles of the solid phase in which are oriented predominantly parallel to the plane of the base surface.

Removal of the liquid phase from deposited layers of a suspension of solid phase particles in the liquid phase or from each layer separately can be carried out both at subatmospheric pressure and at atmospheric pressure, depending on the chosen method of manufacturing the device.

Pressure below atmospheric, in particular cases of obtaining a device, can be used both immediately after applying each individual layer of a suspension of solid organic matter in the liquid phase, and at the drying stage (i.e., removing the liquid phase) of the required number of applied layers of a suspension of solid organic matter in the liquid phase. In this case, spontaneous release of the liquid phase occurs from the volume of the material (sequentially from each layer or from the entire volume of the material) with the formation of a larger number of unstructured voids.

Layer-by-layer application of a suspension of a solid phase in a liquid phase can also provide the claimed device. In this case, after applying the heat-sensitive material, the device is dried by selecting the mode for removing the liquid phase from the applied suspension layers, preferably at a temperature of (20±2)°C for 10 minutes in an air atmosphere, then the layer-by-layer application procedure is repeated until the required coating thickness is obtained . The formation of a microstructure, including particles of the solid phase and a large proportion of voids filled with the gas phase, occurs layer by layer. Layer-by-layer deposition with exposure, preferably at room temperature, between approaches ensures the ordering of the solid phase particles as they are located on the device and the formation of a large proportion of voids, which predominantly form a continuous gas phase. If the particles of the solid phase are flakes, in order to achieve coverage with a minimum layer thickness, it is preferable to arrange them longitudinally “overlapping” based on a thermal indicator. In this case, the scales will be arranged like closed blinds, and a thin layer of scales will be enough to cover the base color (“closed blinds principle”). Due to the spontaneous removal of the liquid phase from the deposited layers of suspension at room temperature, slow sedimentation of the flakes and their packing in a thermodynamically favorable state is ensured. When this technique is used in the preparation of a thermosensitive material, a predominant formation of a continuous solid phase is observed, and the voids filled with gas form a continuous gas phase. When carrying out forced removal of the liquid phase from the applied layers of suspension during heating or when blowing with air, the kinetic processes of solvent evaporation will prevail over the thermodynamic ordering of particles of the solid phase, as a result of which the flakes will form not longitudinal, but transverse structures (“the principle of open blinds”), through which the base will be visible at the same layer thickness, for which, subject to the principle of closed blinds, coverage will be achieved.

Such ordering can also be achieved through the use of a dilute suspension of solid phase particles in the liquid phase (dilution of more than 50%), since in a large volume the flakes will be oriented in the desired manner and settle in an ordered form, in contrast to the use of more concentrated suspensions. In addition, large dilution guarantees a longer process of spontaneous evaporation of the liquid phase, during which the flakes will also be laid according to the principle of closed blinds. Another factor influencing the rate and nature of sedimentation of solid phase particles is the relative difference in the densities of the solvent and solid phase particles. If there is a large difference in density (more than 0.2 g/cm ³ ), solid phase particles will settle out of the suspension too quickly according to the principle of open shutters. At comparable densities or with a difference in densities of less than 0.2 g/cm ^3, a slow settling of solid phase particles will be observed with the formation of the necessary ordered microstructure of the material and compliance with the principle of closed shutters.

Thus, adherence to the principle of closed blinds when forming the microstructure of a heat-sensitive material makes it possible to obtain a material whose microstructure in the initial state has a predominant orientation of solid phase particles parallel to the surface of the base and protective coating.

The application of layers of solid phase suspension in liquid phase is preferably carried out by a method selected from screen printing, flexographic printing, pad printing, silk-screen printing.

The effects described above are applicable to embodiments of the device in which the microstructure of the thermosensitive material is represented by an organic substance, the particles of which are predominantly in the form of flakes, crystals or fibers, i.e. such particles whose linear dimensions exceed their thickness. In this case, the formation of intergrowths (conglomerates) of individual particles (scales, crystals or fibers) of solid organic matter may be observed.

In the case of using a heat-sensitive material containing a solid phase, a binder and voids, a suspension of a fine solid phase in a solution of a binder in a liquid phase is used to prepare the heat-sensitive material. When the liquid phase evaporates, the binder settles on the particles of the solid phase, covering their surface with a thin, uniform layer. In this case, “glazing” occurs both of an individual particle of the solid phase and of the resulting conglomerate of particles.

When applying a suspension of solid phase particles in the liquid phase, the area of the front surface of the device base, which should not be exposed to heat-sensitive material, is sealed with plastic film. A layer of a suspension of solid phase particles in the liquid phase is uniformly applied to the unclosed area of the base using one of the techniques described above or other methods that ensure the formation of the described microstructure.

In preferred embodiments, the thickness of the layer of heat-sensitive material is no more than 800 microns, preferably no more than 450 microns, most preferably no more than 150 microns. The use of the specified thickness of the layer of heat-sensitive material ensures that it operates at a speed of less than 5 seconds, preferably less than 2 seconds, when heated above the threshold temperature. This is due to the fact that such a thickness of the material layer, in combination with the thickness of the thermal indicator base, allows the heat-sensitive material to be heated when short-term overheating occurs during peak load periods and completely transforms it into a melt with an “opaque-transparent” color transition in less than 5 seconds, and also provides necessary heat transfer during air cooling of operating devices.

The front surface area of the base is from 3 mm ² , preferably not less than 10 mm ² , and the surface area of the base coated with the heat-sensitive material is from 3 to 97% of the front surface area of the base, preferably not less than 30% of the front surface area of the base, which allows you to identify triggered devices from a long distance, and also allows you to identify spot heating of a large surface of installations.

In some variants of the utility model, black paint or an inscription is first applied to the unclosed area of the base using solvent dyes, including, in particular, a numerical value of the threshold temperature or other graphic, numerical or text information, and only then a layer of heat-sensitive material is applied. In this case, in advantageous embodiments of the invention, at least 70% of the base area is covered with black paint. In the case of painting at least part of the base black, the heat-sensitive material in the initial state has a white color, and when heated above a threshold temperature, a visual color transition of at least part of the surface of the device “white-black” occurs.

It should be noted that the claimed utility model is not limited to the use of only one heat-sensitive material, and if necessary, the temperature indicator can be supplemented with various heat-sensitive materials to determine whether several threshold temperatures are exceeded.

At the final stage of preparation, the temperature indicator was covered with a transparent protective layer. In some variants of the utility model, a gap can be made between the protective layer and the base, or micro-holes can be made in the transparent protective layer, allowing the gas phase to leave the device after exceeding the recorded temperature. Preferably, the transparent protective layer is selected from transparent elastic polymers. In another variant of the utility model, the device blank is kept at a pressure below atmospheric pressure and then covered with a transparent protective layer, ensuring the tightness of the device and maintaining the pressure inside the voids with a gas phase below atmospheric pressure. For this purpose, in this embodiment of the utility model, transparent elastic polymer films are also used as a protective layer.

In particular embodiments, a recess can be made in the base material of the clip, which is filled with a heat-sensitive material according to the above methods.

In preferred embodiments, the heat-sensitive material is configured to register local overheating of the surface by changing the color of only that part of the heat-sensitive material that was heated above the threshold temperature and maintaining the original color of the heat-sensitive material, which was not heated above the threshold temperature, during uneven heating.

After applying the heat-sensitive material, the device is covered with an elastic protective film, transparent to at least part of visible light, which protects the device from external environmental influences, humidity, UV irradiation and mechanical damage, increases the service life of the device and prevents the heat-sensitive material from draining during a phase transition . Thus, the device is configured to register the excess of a threshold temperature of conductive elements in the open air.

In a particular case, the elastic base 1 can be colored for additional marking of cable phases, mounting wires, harnesses and other elements of electrical equipment, and the color of the base is selected in accordance with GOST 28763-90, which establishes, in particular, color marking in the field of electrical engineering. The color of the elastic base 1 does not affect the visual registration of exceeding threshold temperatures of the surface of the equipment, but provides marking of the device necessary to increase the overall safety of operation of the equipment.

Also, in a particular case, a dye, including black, can be applied to the flexible base, in the area of the heat-sensitive material, before applying the heat-sensitive material. In one embodiment, at least 70% of the area of the base coated with the heat-sensitive material is painted black.

The principle of operation of the device.

A clip, including a base 1 and a heat-sensitive material 2 applied to it and a transparent protective layer 5, is installed on the surface of an electrical wire, behind which temperature control must be ensured, ensuring a tight fit of the device, using fasteners 6 provided by the design of the clip. In another embodiment, the clip is attached to the surface of the electrical wire without additional fastening elements due to the elastic properties of the base material. Regardless of how the clip is attached, the operating principle does not change.

A clip for recording exceeding a threshold temperature with applied heat-sensitive material works as follows. The applied heat-sensitive material 2 in the initial state and until it is heated to a threshold temperature is opaque to at least part of visible light and, in advantageous embodiments of the utility model, has a white color. Until the entire surface of the clip or its individual sections located under the heat-sensitive material 2 is heated to a threshold temperature value, the heat-sensitive material 2 remains opaque to at least part of visible light, thereby preserving the original appearance of the clip. When the surface is heated above the threshold temperature of the thermosensitive material 2 on the entire surface of the thermosensitive material 2 or mainly on the heated section 12 of the thermosensitive material 2, accordingly, irreversible destruction of the microstructure of the thermosensitive material 1 occurs, accompanied by the fusion of particles of the solid phase 7, a decrease in the proportion of voids 8 and, as a consequence , increasing transparency. In this case, the apparent density of the material increases. The heat-sensitive material 2 with a modified microstructure is transparent and exhibits the color of the base 1 underneath the material or the color of the paint 3 applied to the base in the area of the heat-sensitive material. Upon subsequent cooling of the controlled surface, the heat-sensitive material 2 or its part 12 remains transparent and the appearance of the temperature indicator does not return to its original state. This ensures the possibility of visual registration of temperature exceeding the threshold temperature value, both at the moment of overheating and after a long period of time.

With spot heating of the controlled surface, a transparent zone 12 is formed only in that area of the heat-sensitive material that was exposed to heating above the threshold temperature, while maintaining an opaque area of the material in the rest of the area that was not subject to heating.

The numerical value of the threshold temperature 4 can be applied to the front side of the base 1; in particular cases, the threshold temperature value can be applied in an area free from the heat-sensitive material 2, but next to it, or on the base 1 under the heat-sensitive material 2, in the latter case, when the temperature exceeds a threshold value, after an irreversible change in the microstructure of the heat-sensitive material 2, the color of the base 1 and the numerical value of the threshold temperature 4 appear. In particular embodiments, the base can be black, and the heat-sensitive material in the initial opaque state can be white. In this case, after the temperature exceeds the threshold value, a change in the appearance of the thermal indicator is observed with a maximum “white-black” contrast, which additionally ensures the visibility of the triggered thermal indicator and facilitates its visual identification. The implementation of a thermal indicator serves a similar purpose, in which the base has a color other than black, and in the area under the heat-sensitive material 2, which is white in the initial state, black paint is applied. In this case, also when the thermal indicator is triggered, a “white-black” color transition is observed.

In the case of a thermal indicator hermetically coated with an elastic transparent protective layer 5 at atmospheric pressure, at the moment of operation, as a result of the destruction of the microstructure of the thermosensitive material 2 and the delamination of gas and non-gas environments, a bubble will form on the surface of the protective layer 5, which decreases as the device cools. When using a thermal indicator with a sealed protective layer 5 and a pressure inside the voids 8 of a temperature-sensitive material 2 below atmospheric, there will be no formation of a bubble on the surface of the protective layer 5 when the threshold temperature is exceeded, due to the fact that the pressure of the gas phase inside the voids 8 is lower than atmospheric in the initial state, created at the stage of obtaining a thermal indicator blank when applying a protective layer 5, it compensates for the thermal expansion of the gas released when the microstructure of the thermosensitive material 2 is destroyed. In other embodiments of the thermal indicator, to prevent the occurrence of a bubble when the threshold temperature is exceeded, a gap 11a or b can be made between the transparent protective layer and the base Micro-holes 116 can be made in the protective layer, allowing the gas released during activation to escape.

Versions of the clip, in which the thermosensitive material 2 includes particles of the solid phase 7, voids 8 and a binder 10, have a similar operating principle. When the temperature exceeds a threshold value, fusion of particles 7, “glazed” with binder 10, occurs with the release of the gas phase and separation of gas and non-gas environments, as a result of which irreversible destruction of the microstructure of the thermosensitive material 2 also occurs, accompanied by a decrease in the proportion of voids 8 and, as a consequence, increasing the transparency of the material.

Thus, all versions of the thermal indicator have an operating principle based on the irreversible destruction of the microstructure of the thermosensitive material 2, accompanied by the fusion of solid phase particles 7, a decrease in the proportion of voids 8 and, as a consequence, an increase in the transparency of the material and an irreversible change in the appearance of the thermal indicator. Moreover, when the thermal indicator is cooled, the appearance does not return to its original state; preferably, the transparency of the heat-sensitive material does not decrease to its original values when cooled to 20°C and held at this temperature for at least one month, preferably one year or more.

Thus, during a visual inspection of the temperature indicator, it can reliably and with high accuracy (in the range of +/-5°C, mainly +/-2°C, relative to the threshold temperature indicated on the temperature indicator) and speed (no more than 5 seconds, mainly no more than 2 seconds) to register the fact that the temperature of the entire surface or its local area exceeds the threshold value.

Below are preferred embodiments of the claimed thermal indicator, which are illustrative and do not in any way limit the scope of the requested legal protection.

Examples

Example 1. General technology for manufacturing the device

Preparation of thermosensitive material: 100 g of an organic substance with a phase transition temperature corresponding to the threshold registration temperature in the range of 5°C was crushed to a size of 2-3 microns, 300 g of a 3-33% binder solution in water, methanol, ethanol, isopropanol were successively added, ethylene glycol, ethylene glycol monomethyl ether, acetonitrile or mixtures thereof and stirred until smooth. The suspension was immediately used to apply the composition.

For examples, as one of the possible embodiments of the device, halogen-containing polymer bases of various colors were selected, with fire resistance and an electrical strength of at least 5 kV/mm, as well as elasticity that allows them to be placed on electrical wires, preferably with a diameter of 1 to 10 mm without additional fastening elements.

An information element containing the value of the threshold response temperature in degrees Celsius was applied to the base, made in the form of a clip, using solvent dyes. The heat-sensitive material was applied using silk-screen printing in 5-7 layers. Between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for at least one hour, or in a thermostat at a temperature not higher than the operating temperature of the composition for at least three hours, or for 24 hours at room temperature. In its initial state, the heat-sensitive material is white. The device was covered with a transparent elastic protective film.

Example 2.

Tetracosane with a phase transition temperature of 50°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polycaprolactone was used as a binder, and methanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.5 mm, according to the method described in example 1, and the numerical value of the threshold temperature was applied in the zone free of heat sensitive material. The number of layers of heat-sensitive material was 7; between applications, the composition was dried in a vacuum chamber at 100 mm Hg. Art. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.6 mm, and its area was 30% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.05 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 50°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 3.

Ytterbium caprylate with a phase transition temperature of 60°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polyvinyl butyral was used as a binder, and a mixture of methanol with ethylene glycol methyl ether (50/50 vol.%) was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip with additional fastening elements made of red M-40 fluoroplastic, having a thickness in the area of the heat-sensitive material of 0.7 mm, according to the method described in example 1, and the numerical value of the threshold temperature was applied in the area heat-sensitive material before its application, and in the area free of heat-sensitive material information about the service life is printed. The number of layers of heat-sensitive material was 7; between applications, the composition was dried in a thermostat at a temperature of 40°C for three hours. The thickness of the layer of heat-sensitive material was 0.8 mm, and its area was 97% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 5 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 60°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 4 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 4.

Eicosanoic acid with a phase transition temperature of 70°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, melamine-formaldehyde resin was used as a binder, and a mixture of methanol and isobutanol (90/10 vol.%) was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of a copolymer of vinyl chloride and vinyl acetate of red color, having a thickness in the area of the heat-sensitive material of 0.2 mm, according to the method described in example 1, and in the area of the heat-sensitive material before its application The numerical value of the threshold temperature was applied, as well as black paint. The number of layers of heat-sensitive material was 5; between applications, the composition was dried for 24 hours at room temperature. The thickness of the layer of heat-sensitive material was 0.2 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of polyurethane modified with 15% trichloroisopropyl phosphate, 0.15 mm thick.

The device was glued at room temperature onto a cylindrical heating element with a diameter of 10 mm, which was then heated in a controlled manner at a rate of 5°C/min to a temperature of 70°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 5.

Dioctylphosphinic acid with a phase transition temperature of 80°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polyvinyl butyral was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of a copolymer of vinyl chloride and vinylidene chloride, green in color with reflective properties, having a thickness in the area of the heat-sensitive material of 0.35 mm, according to the method described in example 1, and in the area of the heat-sensitive material Before applying the material, a numerical value of the threshold temperature was applied, as well as black paint. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.4 mm, and its area was 3% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 12 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 80°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the thermosensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 6.

Yttrium behenate with a phase transition temperature of 90°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, polybutyl methacrylate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of polyvinylidene fluoride, painted with orange paint with luminescent properties, having a thickness in the area of the heat-sensitive material of 0.15 mm, according to the method described in example 1, and in the area of the heat-sensitive material Before applying it, a numerical value of the threshold temperature was applied, as well as black paint. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a thermostat at a temperature of 70°C for three hours. The thickness of the layer of heat-sensitive material was 0.2 mm, and its area was 30% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.05 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 90°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 4 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 7.

Lanthanum palmitate with a phase transition temperature of 100°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, gelatin was used as a binder, and isopropanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of polyester modified with 6.5% hexabromocyclododecane, yellow in color, having a thickness in the area of the heat-sensitive material of 0.3 mm, according to the method described in example 1, and in the zone Before applying the heat-sensitive material, a numerical value of the threshold temperature was applied, as well as black paint. The number of layers of heat-sensitive material was 6; between applications, the composition was dried for 24 hours at room temperature. The thickness of the layer of heat-sensitive material was 0.5 mm, and its area was 30% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.05 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 100°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 8.

Lanthanum nonadecynate with a phase transition temperature of 110°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, phenoxy resin was used as a binder, and ethylene glycol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.5 mm, according to the method described in example 1, and in an area free of heat-sensitive material, The numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 6; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.5 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.1 mm thick.

The device was glued at room temperature onto a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 110°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 9.

Lanthanum capronate with a phase transition temperature of 120°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polyethylene was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.5 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a thermostat at a temperature of 60°C for three hours. The thickness of the layer of heat-sensitive material was 0.35 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 7 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 120°C with a given accuracy and the fact of operation of the device was recorded by visually recording the increase in transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 3 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 10.

Zinc nonadecanoate with a phase transition temperature of 130°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polycarbonate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.45 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried for 24 hours at room temperature. The thickness of the layer of heat-sensitive material was 0.4 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.02 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 130°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 11.

Zinc palmitate with a phase transition temperature of 140°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, nitrocellulose was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.4 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 6; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.45 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.03 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 140°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 12.

Zinc capronate with a phase transition temperature of 150°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, polyvinylidene fluoride was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.2 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a thermostat at a temperature of 60°C for three hours. The thickness of the layer of heat-sensitive material was 0.3 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 150°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 13.

Lithium stearate with a phase transition temperature of 210°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, polybutyl acrylate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.15 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried for 24 hours at room temperature. The thickness of the layer of heat-sensitive material was 0.4 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.1 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 210°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time it took for the phase transition to occur and the transparency of the thermosensitive material to change was 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 14.

Yttrium capronate with a phase transition temperature of 55°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polyethersulfone was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.25 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.25 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 55°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 3 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 15.

N-hexadecyl-n-pentylhydrogen phosphate with a phase transition temperature of 40°C was used as an organic substance for the preparation of a heat-sensitive material according to Example 1, ethylcellulose was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.15 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.3 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 40°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was less than 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 16.

Palmitic acid anhydride with a phase transition temperature of 60°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polymethacrylate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.35 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 6; between applications, the composition was dried in a thermostat at a temperature of 40°C for three hours. The thickness of the layer of heat-sensitive material was 0.55 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.02 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 60°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 17.

Erucamide with a phase transition temperature of 80°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, polycarbonate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.65 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 7; between applications, the composition was dried for 24 hours at room temperature. The thickness of the layer of heat-sensitive material was 0.75 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.03 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 80°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 4 seconds. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 17.

1-tetradecanol with a phase transition temperature of 40°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, polybutyl acrylate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of chloroprene rubber on a black siliconized base, with a thickness in the area of the heat-sensitive material of 0.1 mm, according to the method described in example 1, and in an area free from heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried in a vacuum chamber at 100 mmHg and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.15 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.05 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 40°C with a given accuracy, and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was less than 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 18.

Docosanitrile with a phase transition temperature of 55°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, polybutyl methacrylate was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black Oramask 831 PVC, with a thickness in the area of the heat-sensitive material of 0.15 mm, according to the method described in example 1, and in an area free of heat-sensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 5; between applications, the composition was dried for 24 hours at room temperature. The thickness of the layer of heat-sensitive material was 0.25 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent protective film made of PVC, 0.15 mm thick.

The clip was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 55°C with a given accuracy and the fact of operation of the device was recorded by visually recording an increase in the transparency of the heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 1 second. After cooling the device to room temperature, the preservation of the transparency of the temperature-sensitive material was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 19.

n-docosylamine with a phase transition temperature of 65°C was used as an organic substance for the preparation of a thermosensitive material according to example 1, polyvinyl butyral was used as a binder, and ethanol was used as a solvent. The suspension was applied by silk-screen printing onto a base made in the form of a clip without additional fastening elements made of black OraJet 3106SG PVC with a recess in the area of the heat-sensitive material, having a thickness in the area of the heat-sensitive material of 0.55 mm, according to the method described in example 1, and in the area , free from thermosensitive material, the numerical value of the threshold temperature was plotted. The number of layers of heat-sensitive material was 7; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.75 mm. The size of the front surface of the device is 12×12 mm (area - 144 mm2 ⁾ , the size of the layer of heat-sensitive material is 10×10 mm (area - 100 ^mm2 ). The device was covered with a transparent protective film made of PVC, 0.05 mm thick.

The device was installed at room temperature on a cylindrical cable heating element with a diameter of 15 mm. Part of the heating element was heated in a controlled manner at a rate of 5°C/min to a temperature of 65°C with a specified accuracy, while the rest of the heating element was not heated. The fact of activation of the part of the device that was subjected to heating was recorded by visually recording an increase in the transparency of the corresponding area of the heat-sensitive material with the appearance of the color of the base. After cooling the device to room temperature, the preservation of the transparency of the corresponding area of the thermosensitive material was visually recorded. Then the heating element was fully heated at a rate of 5°C/min to a temperature of 65°C with a specified accuracy. The fact of complete operation of the device was recorded by visually recording an increase in the transparency of the entire layer of heat-sensitive material with the appearance of the color of the base. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. During heating and cooling cycles, it was observed that the device remained firmly attached to the surface of the heating element.

Example 20.

The area of the base, made in the form of a clip without additional fastening elements made of black OraJet 3951 PVC, on which the heat-sensitive material will be applied, was sealed with a protective polyethylene film, the free area was covered with pigmented yellow Tempilaq thermal paint with a reversible color change temperature of 113°C. After the paint had dried, the protective polyethylene film was removed and a numerical value of the threshold temperature was applied to the surface of the base containing thermal paint using solvent dyes. The thickness of the base containing thermal paint was 0.45 mm. Then a protective polyethylene film was glued to the area where the heat-sensitive material should not fall, and the thermal composition was applied using silk-screen printing in 7 layers. After the layer had completely dried, the protective film was removed. Lanthanum nonadecynate with a phase transition temperature of 110°C was used as an organic substance for the preparation of a thermosensitive material in Example 1, butyl methacrylic resin was used as a binder, and ethanol was used as a solvent. The number of layers of heat-sensitive material was 6; between applications, the composition was dried in a thermostat at a temperature of 60°C for three hours. The thickness of the layer of heat-sensitive material was 0.6 mm, and its area was 70% of the area of the front surface of the device. The device was covered with a transparent elastic protective film made of PVC, 0.05 mm thick.

The device was installed at room temperature on a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a speed of 5°C/min to a temperature of 115°C with a given accuracy and the fact of activation of the zone of the heat-sensitive material of the device with the appearance of the color of the base was recorded, as well as the fact of activation of the thermal paint with color change. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 1 second. After cooling the device to room temperature, the preservation of the transparency of the zone of the heat-sensitive material and the return of the color of the thermal paint to the original color were visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

Example 21.

The area of the base, made in the form of a clip without additional fastening elements made of red Oramask 831 PVC, on which the heat-sensitive material will be applied, was sealed with a protective polyethylene film, the free area was covered with pigmented yellow thermal paint Hallcrest SC with a temperature of irreversible color change of 80°C. After the paint had dried, the protective polyethylene film was removed and a numerical value of the threshold temperature was applied to the surface of the base containing thermal paint using solvent dyes. The thickness of the base containing thermal paint was 0.55 mm. Then protective polyethylene film was glued to the area where the heat-sensitive material should not come into contact, the area was covered with solvent black dye and the thermal compound was applied using silk-screen printing in 6 layers. After the layer had completely dried, the protective film was removed. Zinc capronate with a phase transition temperature of 150°C was used as an organic substance for the preparation of a thermosensitive material according to Example 1, phenol-formaldehyde resin was used as a binder, and ethanol was used as a solvent. The number of layers of heat-sensitive material was 6; between applications, the composition was dried in a vacuum chamber at 100 mmHg. and 20°C for one hour. The thickness of the layer of heat-sensitive material was 0.45 mm, and its area was 30% of the area of the front surface of the device. The device was covered with a transparent elastic protective film made of PVC, 0.15 mm thick.

The device was glued at room temperature onto a cylindrical heating element with a diameter of 1 mm, which was then heated in a controlled manner at a rate of 5°C/min to a temperature of 80°C with a given accuracy, and the fact that the thermal paint was activated with a color change was recorded. Then heating was continued to a temperature of 150°C and the fact of activation of the zone of the heat-sensitive material of the device with the appearance of the color of the base was recorded. The time during which the phase transition occurred and the transparency of the thermosensitive material changed was 2 seconds. After cooling the device to room temperature, the preservation of the transparency of the zone of the heat-sensitive material, as well as the preservation of the changed color of the thermal paint, was visually recorded. During heating and after cooling, it was revealed that the device remained tightly fixed to the surface of the heating element.

These examples do not limit the claimed utility model, however, they clearly reveal special cases of the implementation of the claimed utility model, and also confirm the achievement of a technical result associated with ensuring increased safety of operation of electrical equipment due to the rapid, reliable and reliable detection of defects associated with excessive heating through irreversible registration of the fact that an element of electrical equipment exceeds a given threshold temperature, a device that is conveniently and reliably mounted on wires and other elements of electrical equipment.

The utility model has been disclosed above with reference to a specific embodiment thereof. For specialists, other embodiments of the utility model may be obvious, without changing its essence, as it is disclosed in the present description. Accordingly, the utility model should be considered not limited in scope by the given description and examples.

Claims (21)

1. A device for recording the excess of a threshold temperature, configured to be installed on wires, including a base made of an elastic material, including halogen-containing polymers, opaque to at least part of visible light, made in the form of a clip, partially coated on the front side with a heat-sensitive material that irreversibly changes transparency relative to the initial state when heated above the threshold temperature. 2. The device according to claim 1, in which the halogen-containing polymers mainly contain a structural unit -CH ₂ CHCl-, preferably polyvinyl chloride, preferably cast polyvinyl chloride. 3. The device according to claim 1, characterized in that the base is made in the form of a single structure with the ability to be fixed to electrical wires, preferably with a diameter of 1 to 10 mm, without additional elements. 4. The device according to claim 1, characterized in that the base contains elements for snapping the device onto electrical wires, preferably with a diameter of 1 to 10 mm. 5. The device according to claim 1, characterized in that the area of the front surface of the base is from 3 mm ² , preferably at least 10 mm ² . 6. The device according to claim 1, characterized in that the heat-sensitive material is located in a recess made in the material from which the base of the clip is made. 7. The device of claim 1, wherein the heat-sensitive material is covered with an elastic protective film, transparent to at least part of visible light, preferably made of polyvinyl chloride, most preferably cast polyvinyl chloride. 8. The device according to claim 1, in which the heat-sensitive material in the initial state is painted white, and when the transparency of the heat-sensitive material changes, a visual color transition from white to black occurs. 9. The device according to claim 1, characterized in that the heat-sensitive material irreversibly changes transparency when heated in a range not exceeding 5°C, preferably not exceeding 2°C relative to the threshold temperature. 10. The device according to claim 1, in which the heat-sensitive material in the initial state has a microstructure, including a solid phase and voids, forming a continuous gas phase, the share of which is at least 50 vol.%, and is designed to irreversibly change its appearance upon reaching threshold temperature due to the destruction of the microstructure of the thermosensitive material, accompanied by the fusion of solid phase particles, a decrease in the proportion of voids and an increase in its transparency with the appearance of the color of the base. 11. The device according to claim 10, in which the solid phase of the thermosensitive material includes an organic substance containing a structural fragment C _n H _(2n+1) , where n≥5. 12. The device according to claim 10, in which the solid phase of the thermosensitive material includes an organic substance that is selected from the group: aliphatic fatty acids containing structural fragments C _n H _(2n+1) with n≥12; salts of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C _n H _(2n+1) with n≥5; amides of aliphatic fatty acids containing structural fragments C _n H _(2n+1) with n≥5; aliphatic fatty acid anhydrides containing structural fragments C _n H _(2n+1) with n≥10; fatty aliphatic alcohols containing structural fragments C _n H _(2n+1) with n≥14; fatty aliphatic amines containing structural fragments C _n H _(2n+1) with n≥17; nitriles of fatty aliphatic acids containing structural fragments C _n H _(2n+1) with n≥19, preferably selected from the group: 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. 13. The device according to claim 11, in which the mass content of the solid phase in the heat-sensitive material is at least 50 wt.%, and the heat-sensitive material contains a polymer binder that is transparent to at least part of the visible light in an amount of 1-30 wt.%. 14. The device according to claim 1, characterized in that it has dielectric properties, preferably has an electrical strength of at least 5 kV/mm. 15. The device according to claim 1, in which the heat-sensitive material is configured to change transparency when heated to a temperature exceeding the threshold within no more than 5 seconds, preferably no more than 2 seconds. 16. The device according to claim 1, characterized in that it can be used for color marking of phases of electrical equipment due to the color of the base. 17. The device according to claim 1, in which the surface area of the base coated with the heat-sensitive material is from 3 to 97% of the front surface area of the base, preferably at least 30% of the front surface area of the base. 18. The device according to claim 1, in which the base has reflective properties or is colored using a substance having luminescent properties. 19. The device of claim 1, wherein the substrate is at least partially colored using a substance capable of reversibly or irreversibly changing color when heated. 20. The device according to claim 1, in which the thickness of the base in the area of the heat-sensitive material is no more than 3 mm, preferably no more than 1 mm. 21. The device according to claim 1, characterized in that with uneven heating, a change in transparency occurs only in that area of the heat-sensitive material of the clip that was heated above the threshold temperature.