JPS6341737A - Flexible resistance exothermic element - Google Patents

Abstract

PURPOSE:To lengthen the life of an exothermic element and reduce the life difference between the element and an external fiber material, and improve greatly the flexibility, foiding resistance, and light resistance of the element by a method wherein the element is composed of a flame sprayed molding made of a metal, or an alloy, or a semi-conductor having a specific value of volume resistivity and a fibrous structure of which main component is an organic fiber having a lower melting point than a metal, or an alloy, or semi-conductor. CONSTITUTION:A flame sprayed molding as one component of a flexible resistance exothermic element is composed of a flame-sprayable metal, or alloy, or semi-conductor having higher melting point than an organic fiber as another component of the element or higher melting point than a thermal decomposing temp. The metal, or alloy, or semi-conductor has the value of 8X10<-7>-8X10<2>OMEGAm as a volume resistivity. A flame spraying method introducing a flame spraying material in a state of fine powder into a plasma jet, a method introducing a rod-shaped flame spraying material into fire flames or arc electric discharge to be powdered and melted, and a method introducing a flame spraying material in a state of fine powder into fire flames are desirable for manufacturing the flexible resistance exothermic element.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resistance heating element that is combustible and useful as a surface heating element with a relatively small calorific value per unit area.

Surface heating elements with a relatively small calorific value per unit area are used in blankets with heaters, carpets with heaters, heaters embedded in the floor, and heaters for melting snow and ice on roads and airports. Conventionally, such resistance heating elements have been made by embedding thin resistance wires in a rubber or plastic sheet, and have had the disadvantage of having little flexibility and being thermally insulated when subjected to slightly large deformations. Another drawback was that the burnability changed over time, and the older it got, the harder it became.

For this reason, especially in the case of heater-equipped blankets and heater-equipped carpets, the lifespan of the heating element is significantly shorter than that of the surface fiber material, which is a drawback.

In the case of the resistance heating element of the present invention, fiber material, which has a long life among organic polymers, is used as the heating element material, so the heating element has a long life, and there is little difference in life from the surface fiber material, and it is flexible. , folding durability etc. are greatly improved. In addition, the light resistance can be greatly improved, so it can be embedded in concrete or asphalt and used for melting snow and ice on roads, airports, etc. The present invention has a volume resistivity of 8 x 10" to 8 x 10.
A visible resistance characterized by comprising a thermally sprayed molded product made of a metal, alloy, or semiconductor with a resistance of 2 Ω·m, and a fibrous structure whose main component is an organic fiber having a lower melting point than the gold, alloy, or semiconductor. It is a heating element. If the volume resistivity of the raw material for the spray molding is small, the spray molding cannot be used as a heating element unless the thickness of the spray mold is made thinner and the voltage is lowered.
A volume resistivity of 8×100·m or less is not preferable because it reaches the limit for reducing the thickness of the thermally sprayed molded product. In addition, when the volume resistivity increases, it is necessary to thicken the thermal spray molding and increase the voltage, but the volume resistivity is 8 x 10.
If it exceeds 2 Ω·m, the thermally sprayed molded product becomes thick and cannot be considered to be substantially flammable, which is not preferable.

Raw materials for the thermal spray molding used in the present invention include alloys with relatively high volume resistivity such as nickel-chromium alloy, iron-nickel-chromium alloy, iron-nickel alloy, iron-chromium-aluminum alloy, boron carbide, silicon carbide, germanium, and silicone carbon. Semiconductors such as graphite and mixtures thereof. Since the shape of the spray molded product is irregular, the resistance of the molded product is usually much larger than the value calculated from the volume resistivity of the raw material.

Vapor deposition and plating methods have traditionally been known as methods for coating organic fibers with conductive layers such as metals. However, it is difficult to make a thick uniform film of the mixture, and the cost is generally high.

As a highly efficient technique for coating inorganic materials, thermal spraying is known as a high-temperature coating material that can be coated with 11M fine particles and is sprayed onto the workpiece together with a high-temperature fluid to form molded products. It is widely used as a surface processing technology.

IE is also being used for surface processing of ceramics, etc., but it is difficult for heat transfer to occur during processing for materials with low thermal conductivity and low thermal properties such as organic fiber materials. It has been said that the heat brought in by the thermal spray material raises the temperature of the object to be sprayed, causing deterioration of the fibers and resulting in poor bonding. Furthermore, it has been said that if the temperature of the thermal spray fluid is lowered or the thermal spray is performed from a distance in an attempt to avoid this, the thermal spray particles will not become integrated and will not bond with the fiber material.

Therefore, it is a well-established theory that thermal spray materials cannot be processed unless they have a melting point lower than the softening point or thermal decomposition temperature of the fiber material.

As an example of thermal spraying processing for organic fibers, it is known that lead is thermally sprayed onto cotton cloth to produce radiation shielding work clothes. Furthermore, JP-A No. 52-66798 discloses an example of spraying epoxy resin prepolymer, polyethylene, polypropylene, and nylon 1 as powder for thermal spraying onto vinylon cloth and cotton cloth by thermal spraying using a plasma jet. There is. In all of these examples, the melting point of the organic fiber is higher than the melting point of the thermal spray material, and the maximum temperature of the plasma is around +oooo'(1'), but the actual thermal spraying temperature is It has been thought that the temperature is slightly lower than the melting point or thermal decomposition temperature.The present inventor accidentally discovered this established theory to be incorrect while researching thermal spray technology and arrived at the present invention. JP-A-48-52644 discloses that when steel is sprayed directly onto a hard vinyl chloride plate, a sprayed coating with weak bonding strength is obtained, but when a thermosetting resin is coated on a hard vinyl chloride plate and semi-cured. It is said that if copper is thermally sprayed when copper is present, a thermally sprayed coating with strong bonding strength can be obtained.This method is considered to be advantageous for joining plastic plates and metals, but it is not suitable for joining cloth foils and metals. Compared to laminating fabric sheets and metal films, laminating is generally considered to be more advantageous due to its greater process flexibility. If a layer is provided, the presence of the intermediate layer will have a strong protective effect on the organic fibers in the cloth, so it is thought that a new product can be obtained.For example, the intermediate layer may be made of a metal (alloy) whose melting point is slightly lower than that of the organic fibers. When a metal with a high melting point is thermally sprayed, the latent heat of melting absorbs the heat brought in by the sprayed material and exhibits a protective effect. We sprayed a metal with a higher melting point than the organic fibers on the part without the intermediate layer, and found that that part had greater peel strength than the part with the intermediate layer.
From this, I learned that the conventional theory is wrong.

As a result of various studies, the inventor of the present invention found that it is necessary to shorten the contact time per contact with the high-temperature fluid used for thermal spraying, and to cool it as quickly as possible after contact. It was found that by thermal spraying inorganic materials such as metals and ceramics that have a much higher melting point than the point of the organic fiber, composite materials in the form of threads, ropes, cloths, membranes, or thin plates can be obtained. . If the thickness of the molded product produced by thermal spraying is insufficient, this operation may be repeated.

When thermal spraying is applied to a fibrous structure, the structure is formed into a sheet shape. Sheet-like materials include woven materials, knitted materials, non-woven materials, paper-like materials, fibers, threads, nets, ropes, etc., arranged in parallel in nature, and those compressed in a υ plane by pressure. It is. (Hereinafter, such a structure will be referred to as a sheet-like object.) The sheet-like object that has been thermally sprayed is that! It is used after passing through a commonly used fiber processing process, but it is also possible to untwist the sheet-like material and use it one by one using a thread rope or the like.

It is also possible to spirally wind a single thread or rope around a roller or the like in parallel, spray it, and then unwind it. In the case of netting, it can be processed into a flat shape by stretching it in the direction of the grain. It is also possible to thermally spray a sheet material, slit it into a tape shape, heat it or string it to make it into a rope shape.Sheet materials can be produced in various ways that can be applied to ordinary fibrous materials before, during or after thermal spraying T. It is possible to perform the following processing.

The contact time between the high-temperature fluid used for thermal spraying and the sheet-like material mainly composed of organic fibers is 1 second or less, preferably 1 second per time.
/10 to 1/+oooo seconds.

Specifically, the thermal spray gun, the sheet material, or both are moved, and the relative velocity thereof, that is, the relative speed of the feeding speed of the sheet material and the central axis of the high temperature fluid for thermal spraying, is adjusted to 0.1 m/sec or more.
om/sec or less. The specific device is to slowly feed the fabric while moving the thermal spray gun in a direction K that is almost perpendicular to the sheet.
This is a device that sprays by reciprocating at a fairly high speed, and the sheets are connected like an endless belt and run in a ring at high speed.
A device that performs thermal spraying by slowly moving a thermal spray gun, or a device that performs thermal spraying using a thermal spray gun that moves the sheet slowly between a reversible take-up device and an unwinding device, and a device that performs thermal spraying by slowly moving the sheet between a reversible winding device and an unwinding device. A device that sprays by rotating a parallel button spirally wound at high speed and slowly moving the spray gun in a direction almost perpendicular to the thread or rope.
It is possible to use a device that sprays by hanging a string or rope around a nelson roller, rotating the roller at high speed, and spraying one or more thermal spray guns either in a fixed state or while moving.

In carrying out the present invention, after the sheet material to be thermally sprayed and the high-temperature fluid used for thermal spraying are separated from each other, they are rapidly cooled down in the shortest possible time. Cooling is preferably carried out by spraying a gas or a gas in which various liquids and solids are dispersed onto the thermally sprayed molding. Preferably, air or an inert gas is blown. The flow velocity is 1 m/sec or more, preferably 10 m/sec.
More than a second and less than the speed of sound. It is preferable that cooling is also performed from the back side of the sheet-like material.

For cooling from the back side, it is preferable to use a solid cooling device provided with an internal heat removal mechanism, such as a rotating roller or a plate-like cooling device of various shapes. This is because by bringing the sheet material into close contact with a solid cooling device, it is possible to prevent the sheet-like material from being undulated by the fluid flow for thermal spraying and cooling, resulting in non-uniform thermal spraying.

Since the sheet material to be thermally sprayed in the present invention is porous, a portion of the thermal spray material may pass through the sheet material and come out to the back side. The equipment that cools the sheet material to be thermally sprayed from the back side must be maintained under conditions that will not allow the thermal spraying material to adhere.To do this, the surface must be smoothed to a certain level of gloss, and the surface temperature must be kept below 200'C''. Preferably F
It is preferable that the cooling device is attached with an auxiliary device for bringing the sheet material to be thermally sprayed into close contact with the cooling device, and also a device for scraping off the thermally sprayed material when it adheres. is preferred.

The characteristic of the uninvented resistance heating element is that a fibrous structure mainly made of organic fibers and a spray molded product mainly made of metal or semiconductor are integrated in a multilayered manner, and the bonding force between the image components is This appears to be due to the bonding force on the surface of the organic fibers and the entangled structure at the interface of the same components.

Thermal spray processing of metal materials or semiconductor materials when manufacturing the resistance heating element of the present invention involves forming fine particles of raw materials at a temperature that allows them to be melted or sintered in plasma generated by flames, electric discharge, etc. Alternatively, it is carried by a high-temperature air current and made to collide with the sheet-like material. Then, the relative velocity between the central axis of the sheet-like material and the high-temperature fluid used for thermal spraying is set to 0.1 m/sec or more and 100 mA9 or less, and the sheet-like material is rapidly cooled immediately after it is separated from the high-temperature fluid. As a result, the sheet-like material can be taken out of the high-temperature fluid used for thermal spraying before deterioration due to heat progresses.

Cooling of the sheet-like material can also be added at a stage before it comes into contact with the hot fluid. This cooling increases the heat capacity of the sheet-like material and suppresses deterioration. This operation is repeated until the amount of spraying reaches a desired value, and the metal material or semiconductor material is formed into a film, sponge, or scale shape on the sheet material. Here, the metal fine particles carried by the plasma flow or the high-temperature air flow are melted in their entirety, the surface layer of the particles, or their binder component, and are accelerated to near-sonic or supersonic speeds and collide with the sheet-like object. The particles are compressed to the fiber surface by their own movement and form a film, and some of them pierce the fiber surface and become fixed. In addition, a part of the particles penetrates into the sheet-like material through the gaps between the fibers and fuses with subsequent particles to form a network structure. Particles pressed onto the surface of organic fibers soften and melt the surface area of the organic fibers due to their heat, but by cooling them at a sufficient rate, the thermal spray coating can be formed without softening the core of the fibers. It has been found that it is possible to mold layers. The particles can be formed into a continuous film, an intermittent film, or a layered film by selecting thermal spraying conditions.

Furthermore, by incorporating particles that do not melt during thermal spraying, a sintered body-like molded product or a sponge-like molded product can be obtained. This structure can be used to adjust electrical resistance.

Thermal spraying may be carried out on one side or both sides of a sheet material mainly made of organic fibers. Although it is advantageous in terms of cost since it is possible to use only one type of thermal spraying material since it is possible to use one type of material, there are cases where sufficient functionality cannot be obtained with one type of material, and it is sometimes preferable to use two or more types.

For thermal spraying of two or more types of materials, it is possible to thermally spray them sequentially in a multilayered form, or by thermally spraying a mixture near the boundary between two types of materials, the composition can be formed so that the composition gradually changes from one to the other. It is possible.

Any conventionally known thermal spraying method can be applied, but there is a method in which the thermal spraying material is introduced in powder form into a flame or plasma jet, and a method in which the thermal spraying material is sprayed in a flame or arc discharge. A method of introducing a rod-shaped thermal spray material, crushing it, melting it, and thermal spraying is preferred for manufacturing the resistance heating element of the present invention.

In manufacturing the resistance heating element of the present invention, the relative speed between the sheet material and the spray gun is 0.1 to 100 in any case.
It is necessary to keep it in good condition. If the speed is less than 0.1 m/sec, cooling will be insufficient no matter how you change the spraying conditions, and the organic Ra
deterioration is unavoidable. On the other hand, at a speed close to 100 m/s, it is difficult to move the spray gun, and the only method that can be implemented is to rotate a cooling roller with a sheet-like material on it at high speed. However, if the relative speed exceeds 100 m/s, centrifugal force This makes it difficult for thermal spray particles to stick. The relative speed between the sheet material and the thermal spray gun is preferably 0.5 to 20 m/sec. If the relative velocity is less than 0.5 m, the material to be thermally sprayed and the thermal spraying conditions are severely limited, which is disadvantageous in terms of cost. 20m
/ seconds or more, the length that the sheet-like object travels becomes extremely short due to the overspeed increase during equipment startup, and in order to maintain the uniformity of the sprayed molded product in this area, the amount of spraying is extremely complicated. The disadvantage is that it becomes necessary to carry out control, and the cost of the device increases significantly.

The relative speed between the sheet material and the thermal spray gun is more preferably 1 to 5 ms. When the speed exceeds 1 m/sec, many types of thermal spray materials can be sprayed under conditions where the spray gun reaches its maximum performance, and even if the relative speed is increased further, the production rate based on the weight of the thermal spray material will not increase. . The spray gun can be moved up to 5 m/sec, and below this speed many types of spray processing equipment can be used, making production extremely easy. Particularly in the case of thermal spraying on fabrics and papers, processing can be performed without stopping except when changing the supply of sheet materials, resulting in extremely low costs.

In the case of thermal spraying in multiple layers, thermal spraying materials with extremely high melting points can be thermally sprayed with high efficiency by sequentially spraying materials with high melting points. In particular, when metal is thermally sprayed, as the thermal spray coating becomes thicker, it becomes easier to rapidly cool the coating, and as a result, subsequent thermal spraying tends to become more efficient. Furthermore, when thermal spraying is performed in multiple layers, it is possible to suppress the phenomenon of cracking in the thermal sprayed coating by sequentially spraying layers with higher hardness.

The sheet material mainly made of organic fibers, which is a component of the combustible resistance heating element of the present invention, is a two-dimensional material such as a woven fabric, knitted fabric, nonwoven fabric, braided fabric, or paper made of natural or artificial organic fibers. This includes those that have been brushed, flocked, flocked, resin coated, etc. This includes some inorganic fibers, adhesive resins, fillers, glue,
It is possible to contain various finishing agents.

The thermally sprayed metal, alloy, or semiconductor that is one component of the combustible resistance heating element of the present invention is a thermally sprayable metal or alloy having a melting point higher than the melting point or thermal decomposition temperature of the other component, the organic fiber. It is a thermal spray molded product of alloy or semiconductor. Here, the metal, alloy, or semiconductor has a volume resistivity of 8 x 10'' to 8 x 102 Ω·m.

As the thermal spraying method in the present invention, any conventionally known method can be applied, but there is a method in which the thermal spraying material is introduced in powder form into a plasma jet, and a method in which the thermal spraying material is introduced in the form of a rod into a flame or arc discharge. A method in which a thermal spray material is introduced and then crushed and melted for thermal spraying and a method in which a thermal spray material is introduced in powder form into a flame and then thermal sprayed are preferred for manufacturing the visible resistance heating element of the present invention.

The surface of the spray molded product, which is one of the components of the present invention, has a highly uneven surface, does not have strong luster, and exhibits a so-called satin-like appearance. When the spray molded product has malleability, the surface can be easily smoothed. Smoothening of the surface can be achieved by applying strong pressure to a smooth surface.

Pressure treatment is preferably carried out between rollers made of a hard material having a smooth surface. As long as the material of each layer has ductility, it is possible to smoothen a molded product formed by thermal spraying in multiple layers.

Even in the case of a material that does not have malleability, smoothness can be improved by first thermally spraying a malleable material, performing a smoothing treatment, and then thermally spraying on top of it. However, care must be taken that the smoothing treatment does not narrow the temperature conditions that allow thermal spraying, making thermal spraying difficult.

Due to the undesirable irregularities on the surface of the spray molded product, the wear resistance, lft and lff1 curvature of the resistance heating element of the present invention cannot necessarily be said to be sufficient. To improve this, it is effective to apply a thin layer of organic polymer to the surface. Various organic polymers can be used, but polyurethane, acrylamide, silicone, and epoxy resins are most commonly used. When these resins are used in large quantities, they can improve the gloss of the surface, but they have the disadvantage of decreasing air permeability and fire resistance. In the present invention, it is not necessary to provide the thermal spray molding layer over the entire surface of the sheet material, but it may be provided at regular intervals in the form of stripes, grids, or other patterns. In contrast to providing a conductive layer over the entire surface, it is possible to adjust the resistance of the heating element by providing a conductive layer locally in a specific pattern.

The present invention will be explained below with reference to Examples.

Example 1 A nickel-chromium alloy thermal spray powder was applied to vinyl-on-spun yarn (width weight: 220 g/m2, plain weave, 42 threads/inch x 42 threads/inch) using a plasma spray system 7M device manufactured by Metco, USA. A body (Meteco 43C1 melt casting, volume resistivity 9.8×10 Ω·m) was spray molded to a thickness of about 25 μm. The spraying conditions were: voltage 50 volts, current 160 amperes, argon flow rate 2 normal cubic meters/hour, fabric feed rate 2.2 m/P (one contact time with the spray fluid flame 0.014 seconds), and movement of the spray gun. Speed (perpendicular to cloth feeding direction) o, osm/sec, distance between spray gun and cloth 1
The spraying rate was 20 to 140 r/an, and the number of thermal sprays was 16 times. Cooling air was sent at a flow rate of 12 m/sec toward the point where the cloth escaped from the spray fluid flame to rapidly cool the cloth.

The thus obtained cloth has a good surface condition of 0, and is harder to the touch than the vinylon cloth used as the raw material, but does not exhibit any roughness.

If we express the hardness of the cloth by the distance that a horizontally protruding cloth hangs down from the tip of the support base to a line drawn diagonally downward at 45 degrees, we get a value of +6 (m) compared to 70 for the vinylon cloth used as the raw material. It was found that the fabric was a little stiffer. However, this value was not large enough to be a problem as a characteristic of the fabric.

The abrasion resistance of this fabric was examined using a taper set abrasion tester. The end point of wear is set at 1. on the surface of the cloth. An abrasion test was conducted with a wear wheel C8-17 and a load of 5009 at the point where /2 becomes vinylon fiber, and the abrasion life was 450 times.

The peelability of the alloy layer was investigated. Although the cellophane tape was applied and peeled off 20 times, no substantial peeling was observed.

In order to investigate the wash resistance of this cloth, synthetic detergent 0.5
% solution for 10 minutes, but! j! There were no qualitative changes.

The electrical resistance of this cloth was 18 Ω/m when measured by making it into a tape with a width of 1 m. Take 2 m2 of this cloth, make a cut, paste an insulating film on the cut, and attach a conductive plate to both ends. It was fixed using adhesive.

The resistance between the two electrode plates was 113Ω. When we conducted commercial exchange between the two poles and sandwiched it between a 20ffllll+ thick tufted carpet (base fabric: vinylon, tufts: acrylic), we investigated the changes over time, and found that no particular changes occurred after 3 months of continuous use.

Example 2 The same vinylon cloth as in Example 1 was coated with iron with a diameter of 3.0 mm using a frame spray gun model 12E made by Metco, USA.
Nickel-chromium alloy wire volume resistivity 8.8 x 10
Thermal spraying was performed by supplying -'Ω·m. Thermal spraying conditions were: oxygen flow rate of 2.2 normal cubic meth Iv/hour, acetylene flow rate of 1.0 normal to cubic meth/L/hour, wire feed rate 4. The fabric was fed at a speed of 2.2 m/sec, the moving speed of the thermal spray gun was o, tm, the distance between the thermal spray gun and the fabric was 200 m, and the number of thermal sprays was 12 times. Cooling air was sent at a flow rate of 10 msa toward the point where the cloth escaped from the spray flame to cool the cloth.

The average thickness of the alloy film on the fabric thus obtained was approximately 35 μm.
1 The surface had an appearance like a metal material with a satin finish.

The texture is harder and a little rougher than the raw vinylon cloth, but it's not uncomfortable. If we express the stiffness of the cloth by the distance that the horizontally protruding cloth hangs down 45 degrees from the tip of the support base to the round line - H, we get a value of 18 Cm compared to 7 C++1 of the vinylon cloth used as the raw material, which is quite resistant to thermal spraying. I found it to be hard.

However, this value is not large enough to cause a practical problem when used in resistance heating elements for blankets, etc.

The abrasion resistance of this fabric was examined using a taper set abrasion tester. An abrasion test was carried out using a C8-17 abrasion wheel and a load of 500 Da, with the end point of abrasion being the point at which 1/2 of the surface of the cloth became vinylon fibers, and the abrasion life was 600 times.

In order to examine the peeling resistance of the alloy layer, the cellophane tape was applied and peeled 20 times, but no substantial peeling was observed.

In order to examine the washing resistance of this fabric, a commercially available electric washing machine (Hitachi PF 2500W empty) was used to wash the fabric with 0.5% synthetic detergent.
% solution for 10 minutes, but there was no substantial change.

Is the electrical resistance of this cloth IC? 11Ω/m measured at +1 width
Met. Apply electricity to this cloth to raise the surface temperature to 1000C±3
Changes in properties were investigated by controlling with 6C, but no substantial changes were observed over 30 days.

Example 3 Instead of the vinylon cloth in Example 1, cotton of approximately the same weight,
Fabrics made of wool, polyester, nylon, and acrylic yarn were treated under the same conditions as in Example 1, and the distance between the thermal spray gun and the fabric was adjusted, and there was a suitable distance for each material. However, all the thermal spray coatings obtained at that distance showed excellent abrasion resistance and peeling resistance. In addition, the resulting fabric exhibited flexibility and breathability within a range that allowed it to be used as clothing. The resulting fabric had heat resistance, flammability, and durability within a range that could be used as a hook-resistance heating element.

Comparative Example 1 In Example 1, the cloth feed was stopped and the distance between the thermal spray gun and the cloth was adjusted to perform the treatment, but the thermal spray coating was not formed at a distance where the vinylon fibers did not melt, and the conditions under which the thermal spray coating was formed Melting of the vinylon fiber occurred.

When the speed of the spray gun is increased to 0.1 m/#, conditions are created in which the vinylon fibers do not melt and a spray coating is formed. At this time, the rate of scattering of the sprayed material was large and the growth of the film was slow.

Example 4 Instead of the vinylon cloth in Example 2, fabrics made of cotton, wool, polyester, nylon, and acrylic spun yarns of approximately the same date were used in place of the vinylon cloth in Example 2, and treated under the same conditions as in Example 2. A thermal sprayed coating with excellent properties and peel resistance was obtained. In addition, the resulting fabric has a flexibility that allows it to be used as clothing.
It exhibited air permeability, and had heat resistance and durability within a range that could be used as a resistance heating element.

Example 5 The fabric weight of the vinylon cloth of Example 2 is 80 to 100 g/m
When the long fiber cloths of polyester, nylon, vinylon, and acrylic from No. 2 were treated under the same conditions as in Example 2, thermal sprayed coatings with excellent abrasion resistance and peeling resistance were obtained and used as resistance heating elements. Demonstrated heat resistance and durability within the possible range.

Example 6 Instead of the nickel chromium alloy powder of Example 1, a mixture powder of 75% graphite, 25% mesoface pitch, a mixture powder of 75% carbon black, 25% mesoface pitch, 85% iron sulfide, and 15% alumina were used. When we thermally sprayed a mixture powder and a powder mixture of 60% black ferrite and 40% alumina, a uniform and good sprayed film was formed in both cases, and the heat resistance and durability were within the range that could be used as a resistance heating element. showed his sexuality.

Example 7 Instead of the iron-nickel-chromium alloy wire of Example 2, an iron-nickel alloy iron-chromium-aluminum alloy stainless steel was thermally sprayed, and a good thermal sprayed coating was formed in each case, making it suitable for use as a resistance heating element. Demonstrated heat resistance and durability within the possible range.

Patent applicant RiRashi Co., Ltd. Representative Patent Attorney Ken Honda

Claims (2)

[Claims] (1) Volume resistivity is 8 x 10^-^7 ~ 8 x 10^2
A flexible resistance heating device characterized by comprising a thermally sprayed molded product made of a metal, alloy, or semiconductor of Ω·m, and a fibrous structure whose main component is an organic fiber having a lower melting point than the metal, alloy, or semiconductor. body (2) In the preceding paragraph, the combustible resistance heating element is characterized in that the organic fiber at the time of forming the thermally sprayed product is in the form of a sheet.