RU2403686C1 - Sheet heating coil - Google Patents

Abstract

FIELD: electricity. ^ SUBSTANCE: sheet heating coil contains a substrate sheet made of an electric insulating material, and wires made of a conductive material and distanced from each other on the substrate sheet. The sheet heating coil contains at least one resistor sheet with the positive temperature coefficient being in an electric contact with the wires and self-heated up in response to electric power supplied by wires. This at least one resistor sheet with positive temperature coefficient can contain a flame retardant and/or a moisture protection film. When the sheet heating coil according to the present invention is used for heating automobile seats or a steering wheel, a passenger sitting thereon feels comfortable, and a driver feels comfortable while holding a steering wheel. ^ EFFECT: sheet heating coil according to the present invention exhibits excellent flexibility, strength and reliability, and has low manufacturing price. ^ 60 cl, 44 dwg

Description

Technical field

The present invention relates to a heating element, and in particular, the present invention relates to a sheet heating element with an excellent positive temperature coefficient (PTC) characteristic. The sheet heating element is so flexible that it can be attached to the surface of household appliances of any shape.

State of the art

A positive temperature coefficient characteristic is a characteristic consisting in an increase in resistance along with an increase in temperature. A sheet heating element having such a characteristic of a positive temperature coefficient has the property of self-regulation of radiated heat. Until now, a resistor has been used in fuel elements such as a sheet heating element. Such a resistor was formed from resistor ink with a polymer base and electrically conductive material dispersed in a solvent.

These resistive inks carry out printing on the base material, forming a heating element. The ink is dried and then sintered to form a sheet resistor (see Patent Reference 1, Patent Reference 2 and Patent Reference 3). Such a resistor radiates heat when an electric current is passed through it. The electrically conductive material used in this type of resistor is typically carbon black, metal powder, graphite, and the like. A crystalline polymer is usually used as the polymer base. A sheet heating element formed from such materials has a positive temperature coefficient.

In FIG. 1A is a transparent top view of the prior art sheet heating element described in Patent Reference 1. For simplicity of description, the drawing shows a view of the internal structure of the heating element. In FIG. 1B is a sectional view taken along line 1B-1B of FIG. 1A. As shown in FIG. 1A and 1B, the sheet heating element 10 comprises a substrate 11, a pair of electrodes 12, 13, a polymer resistor 15, and a coating material 15. The electrodes 12, 13 form a comb shape. The substrate 11 is a material having electrical insulating properties, which is made of a polymer, for example, in the form of a polyester film.

The electrodes 12, 13 are made by applying a conductive paste, such as silver paste, to the substrate 11, after which the paste is dried. The polymer resistor 14 is in electrical contact with the comb-shaped electrodes 12, 13, and these electrodes supply power to the polymer resistor. The polymer resistor 14 has a positive temperature coefficient. The polymer resistor 14 is made of polymer resistive inks and these inks are deposited and dried in a position in which there is electrical contact with the electrodes 12, 13 on the substrate. The coating material 15 is made of the same type of material as the substrate material 11, and protects the electrodes 12, 13 and the polymer resistor 14 by closing them.

If a polymer film is used as the substrate material 11 and the coating material 15, thermoplastic resin 16, such as modified polyethylene, is pre-glued to the coating material 15. Then, the substrate 11 and the coating material 15 are pressed by heating. Accordingly, the substrate 11 and the coating material 15 are connected. The coating material 15 and the thermoplastic resin 16 isolate the electrodes 12, 13 and the polymer resistor 14 from the external environment. Therefore, the performance of the sheet heating element 10 is maintained for a long time.

In FIG. 2 shows a simplified sectional view of the structure of the device that applies the coating material 15. As shown in the drawing, the laminator 22 has two heated rolls 20, 21 that perform thermal compression. In this process, the substrate 11, on which the electrodes 12, 13 and the polymer resistor 14 are preformed, and the coating material 15, on which the thermoplastic resin 16 is previously applied, are placed one on top of the other and fed to the laminator 22. They are subjected to thermal compression by hot rolls 21, 22 , form a single sheet heating element.

A polymer resistor formed in this way has a positive temperature coefficient when the resistance value increases with temperature, and when a certain temperature is reached, the resistance value increases sharply. Since the polymer resistor 14 has a positive temperature coefficient, the sheet heating element 10 has the property of self-regulation of temperature.

Patent Reference 2 discloses a positive temperature coefficient composition made of an amorphous polymer, crystalline polymer particles, electrically conductive carbon black, graphite, and an inorganic filler. Such a composition having a positive temperature coefficient is dispersed in an organic solvent to obtain ink. Then, ink is applied to a polymer film equipped with electrodes to obtain a polymer resistor. Additionally, heat treatment is performed to crosslink the polymer. A polymer film is applied to the polymer resistor as a protective layer, thereby obtaining a finished sheet heating element. This sheet heating element according to patent reference 2 has the same properties of a positive temperature coefficient when radiating heat as the device according to patent reference 1.

In FIG. 3 shows a cross section of another sheet heating element according to the prior art described in Patent Reference 3. As shown in FIG. 3, the sheet heating element 30 has a flexible substrate 31. The electrodes 32, 33 and the polymer resistor 34 are sequentially printed onto this flexible substrate. Then, a flexible coating layer 35 is formed on top of them. The substrate 31 has the properties of a gas barrier and water tightness. Substrate 31 contains a polyester non-woven material having long fibers, and a thermoplastic film, for example, a type of polyurethane, is adhered to the surface of this polyester non-woven material. The substrate 31 may be impregnated with a liquid, for example, polymer resistive ink.

The covering layer 35 contains a polyester non-woven material, and a thermoplastic film, for example of the type of polyesters, is adhered to the surface of this polyester non-woven material. The covering layer 35 also has the properties of a gas barrier and water resistance. The cover layer 35 is adhered to the substrate 31, completely covering the electrodes 32, 33, and the polymer resistor 34. The sheet heating element 30 according to Patent Reference 3 consists of a total of six layers. Such a sheet heating element according to patent reference 3 also has a positive temperature coefficient, as does the device according to patent reference 1.

In the known sheet heating element 10 according to Patent Reference 1 and Patent Reference 2, a rigid material, for example a polyester film, is used as the substrate 11. In addition, the known heating element 10 has a five-layer structure made of a substrate 11, comb electrodes 12, 13 printed on it, a polymer resistor 14, and a coating material 15 on which an adhesive layer is applied. As the thickness increases, the sheet heating element 10 becomes less and less flexible. When such a sheet heating element 10, not having sufficient flexibility, is used as a heater for car seats, the passenger is uncomfortable to sit. When such a non-flexible sheet heating element is used to heat the steering wheel, it is inconvenient to hold such a wheel in your hands.

Since the heating element 10 has the shape of a sheet, for example, when used as a heater for car seats and when a passenger sits on it, the force is applied to the heating element as a whole and the heating element 10 changes shape. Typically, the closer to the edge of the heating element 10, the greater the amount of deformation. Therefore, wrinkles on the heating element are formed unevenly. These wrinkles can cause cracks in the comb electrodes 12, 13 and in the polymer resistor 14. Accordingly, such a heating element is considered to be short-lived.

The polyester sheets used in the substrate 11 and in the coating material 15 do not have ventilation properties. Therefore, when the heating element 10 is used as a heater of the car seat or as a heater of the steering wheel, the moisture generated by the passenger or driver is easily collected on them. Driving or riding for a long time becomes very uncomfortable.

On the other hand, in the case of the sheet heating element 30 according to patent reference 3, the electrodes 32, 33, the polymer resistor 34, the substrate 31 and the cover layer 35 are flexible, therefore, when using the car seat as a heater or the steering wheel heater, sit or hold the steering wheel conveniently. However, since the heating element 30 is formed of six layers, the disadvantage is the low productivity in manufacturing and the high cost of such devices.

Patent Reference 1: Unexamined Japanese Patent Application No. S56-13689.

Patent Reference 2: Unexamined Japanese Patent Application No. H8-120182.

Patent Reference 3: US Patent No. 7,049,559.

SUMMARY OF THE INVENTION

The present invention solves these problems of the prior art and its aim is to create a sheet heating element having high rates of flexibility, durability and reliability, as well as having a low cost. When the sheet heating element of the present invention is used as a car seat heater or a steering wheel heater, it is convenient for the passenger to sit and it is convenient for the driver to hold the steering wheel.

The sheet heating element of the present invention comprises a substrate sheet made of an electrically insulating material, a conductor made of electrically conductive material and spaced apart therebetween, and a sheet substrate. The sheet heating element further comprises at least one sheet of a resistor with a positive temperature coefficient in electrical contact with the wires, and configured to heat up with self-regulation when applying electric current through the wires.

This at least one positive temperature coefficient resistor sheet may have a thickness of 20-200 μm or, preferably, 30-100 μm.

This at least one positive temperature coefficient resistor sheet may comprise a polymer composition and an electrically conductive material. The polymer composition may contain a reactant resin and a reactive resin crosslinked with a reactant resin. The electrically conductive material may comprise at least one component from a series including carbon black and graphite. This at least one sheet of resistor with a positive temperature coefficient can be made with the possibility of melting under the influence of heat to provide electrical contact with the conductors.

This at least one positive temperature coefficient resistor sheet may have an electrical resistance in the range of from 0.0007 MΩ to 0.016 MΩ or, preferably, from 0.0011 MΩ to 0.0078 MΩ.

This at least one positive temperature coefficient resistor sheet may have a flame retardant. The flame retardant may contain at least one flame retardant from a series including a phosphorus-containing flame retardant, a nitrogen-based flame retardant, a silicon-based flame retardant, an inorganic flame retardant, and a halogen-based flame retardant. The flame retardant composition is contained in at least one resistor sheet with a positive temperature coefficient of 5% by weight or more, preferably 10-30% by weight, or optimally 5-25% by weight. Due to the inclusion of a flame retardant, this at least one sheet of resistor with a positive temperature coefficient satisfies at least one of the following conditions:

(a) when the end of this at least one positive temperature coefficient resistor sheet is fired by a gas burner flame, and the gas burner flame goes out after 60 seconds, this at least one positive temperature coefficient resistor sheet does not burn even if it is carbonized.

(b) when the end of this at least one sheet of resistor with a positive temperature coefficient is fired by a gas burner flame, this at least one sheet of resistor with a positive temperature coefficient burns for no more than 60 seconds, but the flame goes out within 2 inches (50.8 mm ), or

(c) when the end of this at least one sheet of resistor with a positive temperature coefficient is fired by the flame of a gas burner, even if this at least one sheet of resistor with a positive temperature coefficient is ignited, the flame does not propagate faster than 4 inches (101.6 mm) per minute, on an area 1/2 inch (12.7 mm) thick from the surface.

This at least one positive temperature coefficient resistor sheet may comprise a moisture barrier polymer. The moisture proof polymer may comprise a copolymer of ethylene vinyl alcohol, a thermoplastic polyester resin, a polypropylene resin, or a combination thereof. The moisture-proof polymer is contained in at least one resistor sheet with a positive temperature coefficient in an amount of 10% by weight or more, preferably 10-70% by weight, or, optimally, 30-50% by weight.

Wires can be sewn onto a backing sheet. The wires may have a diameter of 1 mm or less, preferably 0.5 mm, and a resistance of less than 1 Ohm / m. The electrically conductive material from which the wires are made may be copper, tinned copper, or an alloy of copper and silver. Wires can be spaced approx. 70-150 mm.

This at least one positive temperature coefficient resistor sheet may have an elasticity higher than that of the substrate sheet and stretch more than 5% under a load of less than 7 kgf.

The substrate sheet can be made either of non-woven material or of needle-punched fabric formed from polyester fibers. The sheet heating element may further comprise a coating sheet made of an electrically insulating material and interacting with the substrate sheet to cover the wires and this at least one sheet of resistor with a positive temperature coefficient. The coating sheet may be made of either non-woven material or fabric formed from polyester fibers. At least one of the sheets of the substrate or coating may contain a flame retardant.

In the sheet heating element of the present invention, wires may extend between this at least one positive temperature coefficient resistor sheet and the substrate sheet. Alternatively, at least one positive temperature coefficient resistor sheet is disposed between the wires and the substrate sheet.

The sheet heating element of the present invention may further comprise a moisture barrier film. The moisture barrier film may comprise a copolymer of ethylene vinyl alcohol, a thermoplastic polyester resin, a polyamide resin, a polypropylene resin, or an ionomer, or combinations thereof. The moisture barrier film may have a thickness of 5-100 microns or, preferably, 10-50 microns. A moisture barrier film is disposed between this at least one positive temperature coefficient resistor sheet and the substrate sheet. The moisture barrier film may contain a flame retardant.

At least one of the wires may extend in a zigzag fashion. The wires may be laid so that more than two wires are supplied with power to each of the at least one sheet of resistor with a positive temperature coefficient.

The sheet heating element of the present invention may further comprise conductive films located between the conductors and this at least one sheet of resistor with a positive temperature coefficient. The electrical conductive films may be made of graphite paste or resin containing graphite.

This at least one positive temperature coefficient resistor sheet comprises a nonwoven fabric or fabric impregnated with a positive temperature coefficient resistive material.

The sheet heating element of the present invention may further comprise a coating film made of a thermoplastic elastomer. The coating film may be made of a thermoplastic elastomer based on a polyolefin, a thermoplastic elastomer based on styrene, or a thermoplastic elastomer based on urethane, or a combination thereof.

A plurality of slots or a plurality of slots can be made in the substrate sheet and in at least one positive temperature coefficient resistor sheet.

Brief Description of Attached Drawings

FIG. 1A is a transparent top view of a sheet heating element of the prior art.

FIG. 1B is a sectional view of the sheet heating element of FIG. 1A.

FIG. 2 is a simplified cross-sectional view of an example construction of a prior art sheet metal heating element production apparatus.

FIG. 3 is a cross-sectional view of another sheet heating element of the prior art.

FIG. 4A is a plan view of a sheet heating element according to 1 embodiment of the present invention.

FIG. 4B is a sectional view of the sheet heating element of FIG. 4A.

FIG. 4C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 4A.

FIG. 4D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 4A.

FIG. 5A is a transparent side view of a car seat to which a sheet heating element according to an embodiment of the present invention is attached.

FIG. 5B is a transparent front view of the seat of FIG. 5A.

FIG. 6A and 6B are views of 1 embodiment of a polymer resistor used in the present invention.

FIG. 6C and 6D are views of a 2 embodiment of a polymer resistor used in the present invention.

FIG. 7A is a plan view of a sheet heating element according to Embodiment 2 of the present invention.

FIG. 7B is a sectional view of the sheet heating element shown in FIG. 12A.

FIG. 7C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 7A.

FIG. 7D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 7A.

FIG. 8A is a plan view of a sheet heating element according to embodiment 3 of the present invention.

FIG. 8B is a sectional view of the sheet heating element of FIG. 8A.

FIG. 8C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 8A.

FIG. 8D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 8A.

FIG. 9A is a plan view of a sheet heating element according to embodiment 4 of the present invention.

FIG. 9B is a sectional view of the sheet heating element of FIG. 9A.

FIG. 9C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 9A.

FIG. 9D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 9A.

FIG. 10A is a plan view of a sheet heating element according to Embodiment 5 of the present invention.

FIG. 10B is a sectional view of the sheet heating element of FIG. 10A.

FIG. 10C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 10A.

FIG. 10D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 10A.

FIG. 11A is a plan view of a sheet heating element according to embodiment 6 of the present invention.

FIG. 11B is a sectional view of the sheet heating element of FIG. 11A.

FIG. 11C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 11A.

FIG. 11D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 11A.

FIG. 12A is a plan view of a sheet heating element according to embodiment 7 of the present invention.

FIG. 12B is a sectional view of the sheet heating element of FIG. 12A.

FIG. 12C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 12A.

FIG. 13A is a plan view of a sheet heating element according to Embodiment 8 of the present invention.

FIG. 13B is a sectional view of the sheet heating element of FIG. 13A.

FIG. 13C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 13A.

FIG. 13D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 13A.

FIG. 14A is a plan view of a sheet heating element according to embodiment 9 of the present invention.

FIG. 14B is a sectional view of the sheet heating element of FIG. 14A.

FIG. 14C is a sectional view of a first modified embodiment of the sheet heating element of FIG. 14A.

FIG. 14D is a sectional view of a second modified embodiment of the sheet heating element of FIG. 14A.

Detailed Description of Preferred Options

The following is a description of embodiments of the present invention with reference to the attached drawings. It should be noted that the present invention is not limited to these options. In addition, the structures related to the different options can be appropriately combined.

1 option sheet heating element

The following is a description of an embodiment of a sheet heating element in which the above-described polymer resistor is used. In FIG. 4A is a plan view of 1 embodiment of a sheet heating element of the present invention, and FIG. 4B is a sectional view of the sheet heating element of FIG. 4A on line 4B-4B.

The sheet heating element 40 comprises an insulating substrate 41, a first wire electrode 42A, a second wire electrode 42B, and a polymer resistor 44. The wire electrodes 42A, 42B are sometimes collectively referred to as wire electrodes 42. The wire electrodes 42 are sewn to the insulating substrate 41 by a thread 43. The polymer resistor in film form is applied over them by thermal adhesion.

Sheet heating element 40 is made as follows. First, the wire electrodes 42A, 42B are symmetrically placed on the insulating substrate 41. Next, the wire electrodes 42A, 42B are partially sewn to the insulating substrate 41 by thread 43. Then, using, for example, an extruder with a T-shaped head, the polymer resistor 44 is extruded in the form of a film onto an insulating the substrate 41. After that, the polymer resistor is deposited using a laminator and attached to the insulating substrate 41.

The thickness of the polymer resistor 44 is not particularly limited, but taking into account the flexibility, cost of materials, the corresponding value of resistance and strength under load, its thickness can be 20-200 microns, preferably 300-100 microns.

After the polymer resistor 44 is fused to the wire electrodes 42 and to the insulating substrate 41, a hole is punched in the central part of the sheet heating element. The position in which the hole is punched in the central portion is not limited to the position shown in the drawing. There are cases when a hole is punched in the central portion in other positions, depending on the application. To avoid piercing the electrodes, the layout of the wire electrodes 42 should be changed.

The above-described sheet heating element 40 is used, for example, as a car seat heater. In this case, as shown in FIG. 5A and 5B, the sheet heating element 40 is attached to the inside of the seat 50 and to the back 51 rising from the seat 50. The seat 50 and the back 51 are made of seat base material 52 and seat cover 53 covering the base material 52 of the seat. The base material 52 of the seat is made of a flexible material, for example, in the form of an urethane cushion, and changes shape under the load of a sitting man, and after removing the load restores shape. The sheet heating element 40 is mounted so that the side of the household polymer resistor 44 is facing the seat base material 52 and the substrate side 41 is facing the seat cover 53.

Since the sheet heating element 40 has a positive temperature coefficient, it does not consume much energy since the temperature rises rapidly. A positive temperature coefficient heating element must have an additional temperature controller. This optional temperature controller controls the temperature of the heater by turning the power on and off. In particular, when a heating element emits linear thermal rays, several places with a reduced temperature occur between these rays. In order to minimize such places with a reduced temperature, in the case of a heating element without a positive temperature coefficient, when the power is supplied, the temperature rises to approx. 80 ° C. Therefore, the heating element without a positive temperature coefficient must be placed in the seat at a certain depth under the seat cover 53.

Conversely, in the case of sheet heating element 40 having a positive temperature coefficient, the temperature to which it is heated, automatically maintained at 40-45 ° ^C. As the temperature to which heats a heating element 40 is low, it can be positioned closer to trim 53. In addition, since the heating element is located adjacent to the upholstery 53, it can quickly transfer heat to the seated passenger. Moreover, since the temperature to which it is heated is low, energy consumption can be reduced.

The following is a detailed description of the structure of the sheet heating element 43 of the present invention. In FIG. 6A-6D show examples of a polymer resistor 44 used in a sheet heating element of the present invention. In FIG. 6A-6B show a polymer resistor 44 that uses a fine conductor, such as carbon black. In FIG. 6C and 6D show a polymer resistor that uses a conductive fiber. In FIG. 6A and 6C show the internal state of the polymer resistor at room temperature, and FIGS. 6C and 6D show the internal state of the polymer resistor when the temperature rises relative to the state shown in FIG. 6A and 6B.

In the polymer resistor shown in FIG. 6A and 6B, fine conductors 60 are used, for example carbon black. The finely dispersed conductors 60 enter into point contact in the polymer composition 62, forming conductive channels. When a current is applied to the electrodes 42A, 24B, it flows through the fine conductors 60, heating the polymer resistor 44. When the polymer resistor 44 is heated, the polymer composition 62 expands. Therefore, as shown in FIG. 6B, the conductive channels created by the fine conductors 60 are broken. As a result, the resistance of the polymer resistor 44 increases sharply.

In the polymer resistor 44 shown in FIG. 6C and 6D, fibers are used as conductors 61. These fibers 61 are longitudinally placed on top of each other in the polymer composition 62, forming conductive channels. When a current is applied to the electrodes 42A, 42B, the polymer resistor 44 heats up and as it heats up, the resistance of the polymer resistor 44 increases sharply.

Examples of fiber conductors 61 include ceramic fibers made of tin oxide coated with antimony additives, conductive ceramic hairs based on potassium titanate, copper or aluminum metal fibers, metallized glass fiber with conductive layers formed on their surface, carbon fiber, carbon nanotubes or conductive polymer fibers made of polyaniline, etc. In addition, scaly conductors can be used instead of fiber conductors 61. Examples of flake conductors include ceramic flakes, such as mica flakes with conductive layers formed on their surface, metallic flakes made of copper and aluminum, etc., or flake graphite.

The above conductors can be used individually or in a mixture of two or more types, selected so as to create the required positive temperature coefficient.

The polymer composition 62 of the polymer resistor 44 is formed by mixing a reactant resin, which shows the characteristics of a positive temperature coefficient, and a reactive resin, which reacts with the reactant resin. The reactant resin is preferably a modified polyethylene having a carboxyl group. The reactive resin is preferably a modified polyethylene having an epoxy group. When mixing them with each other, the carboxyl groups in the reactant resin create a chemical bond with the oxygen of the epoxy groups in the reactive resin, so the polymer resistor contains a crosslinked structure.

Thanks to such a crosslinked structure, the temperature characteristics of the coefficient of thermal expansion and the melting characteristics of the polymer resistor 44 become more stable than if the polymer composition 62 was formed only from a reactant resin. Since the reactant resin and reactive resin are firmly connected due to the crosslinked structure, even with repeated heating and cooling, leading to multiple thermal expansion and thermal compression, the temperature characteristics of the coefficient of thermal expansion and melting of this polymer resistor are preserved, therefore, their change in time does not occur. In other words, even with time, the polymer resistor 44 maintains constant temperature characteristics of the coefficient of thermal expansion and a constant melting temperature.

The crosslinking reaction can occur not only through oxygen, but also through nitrogen. A crosslinking reaction occurs if a reactive resin containing a functional group comprising at least one element from a series containing oxygen and nitrogen and a reactant resin having a functional group capable of reacting with this functional group are mixed by stirring. Examples of the functional groups of the reactant resin and the functional groups of the reactive resin, in addition to the above epoxy and carboxyl groups, are given below.

Examples of functional groups of the reactant resin, in addition to carbonyl groups, include epoxy groups, carboxyl groups, ester groups, hydroxyl groups, amine groups, vinyl groups, maleic anhydride groups, and oxazoline groups in the additional polymerization. Examples of functional groups of the reactive resin, in addition to epoxy groups, include maleic anhydride groups and oxazoline groups.

Since the car seat heater should be heated to a relatively low temperature of 40-50 ° C, a positive temperature coefficient reactant resin can preferably be a low melting point olefin resin, for example, an ethylene vinyl acetate copolymer, an ethylene vinyl acrylate copolymer, an ethylene methylene acrylate copolymer an ethylene butyl acrylate copolymer, or another ether type ethylene copolymer.

Resin composition 52 is optionally prepared by mixing a reactant resin and a reactive resin. A positive temperature coefficient can be obtained even if only reactant resin is used. Therefore, if a slight change in the positive temperature coefficient is allowed over time, only reactant resin can be used. When only reactant resin is used, its type is suitably selected in accordance with the required value of the positive temperature coefficient.

In the above example, the reactant resin and the reactive resin are reacted so as to impart a crosslinked structure to the reactant resin in the polymer composition 62. However, a non-reactive crosslinking agent can be used. In addition, it is also possible to form a crosslinked structure in the reactant resin without using a reactive resin, instead irradiating the reactant resin with an electron beam. In this case, you can use a reactant resin that does not have the above functional groups.

Since the polymer resistor 44 is in the form of a flexible film, when an external force is applied to the sheet heating element 40, it stretches and changes its shape in the same way as the insulating substrate 41. The polymer resistor 44 must have the same or greater flexibility as the insulating substrate 41. If the polymer resistor 44 has the same or greater flexibility as the insulating substrate 41, then the durability and reliability of the polymer resistor 44 increases because the insulating substrate has a greater mechanical strength than the polymer a resistor 44, and when an external force is applied, it limits the stretching or changing shape of the polymer resistor 44.

If the polymer resistor 44 is used in the car seat heater, the presence of flame retardant in the polymer resistor 44 is an additional advantage. The car seat heater must comply with the U.S. Flammability Standard. FMVSS 302. More specifically, it must satisfy any one of the following requirements:

(1) when the end of the polymer resistor 44 is fired by the flame of a gas burner, and the flame of the gas burner goes out after 60 seconds, the polymer resistor 44 does not burn, even if it is charred.

(2) when the end of the polymer resistor 44 is fired by a gas burner flame, the polymer resistor 44 burns for no more than 60 seconds, but the flame goes out within 2 inches (50.8 mm).

(3) when the end of the polymer resistor 44 is burned with the flame of a gas burner, even if this polymer resistor 44 is ignited, the flame does not propagate faster than 4 inches (101.6 mm) per minute over an area 1/2 inch (12.7 mm thick) ) from the surface.

Fire resistance is determined as follows. The end of the sample is fired by the flame of a gas burner. When the flame is extinguished after 60 seconds, the sample does not burn, and even the charred remains of the sample do not burn. Self-extinguishing refers to the case when the sample burns for no more than 60 seconds and the charred area does not exceed 2 inches (50.8 mm).

The flame retardant may be a phosphorus-based composition, for example, ammonium phosphate or tricresyl phosphate; a nitrogen-based composition such as melamine, guanidine or guanyl urea; or a silicon-based composition or a combination thereof. Inorganic flame retardants, such as magnesium oxide, antimony trioxide, or halogen-based flame retardants, such as bromine or chlorine based compounds, can be used.

A fire retardant composition having a liquid state at room temperature or having a melting point such as to melt at a mixing temperature provides a particular advantage. The flexibility of the polymer resistor can be enhanced by using at least one of the phosphorus, ammonium, or silicon based compositions, thereby increasing the durability and reliability of the sheet heating element.

The amount of flame retardant added is determined as follows. If the flame retardant is insufficient, the resistance to fire is weakened and none of the above conditions are met. In view of this, the amount of flame retardant added to the polymer resistor 44 should be 5% by weight or more. However, as the amount of flame retardant composition increases, the compositional balance between the polymer composition 62 and the conductor 60 or the conductor 61 contained in this composition is violated, the resistance of the polymer resistor 44 increases, and the positive temperature coefficient decreases. In view of this, the amount of the flame retardant added is preferably 10-30% by weight, and optimally 15-25% by weight relative to the polymer resistor 44.

It is useful to add a moisture-proof resin to the polymer resistor 44 in order to make the resistor resistant to moisture. This resistance prevents damage to the polymer resistor by contact with liquid chemicals, such as inorganic oils, including engine oil, non-freezing fluids, such as brake fluid, etc., or with low molecular weight solvents such as diluents and other organic solvents.

When the polymer resistor 44 comes into contact with such liquid chemicals, the polymer composition 62, which contains large amounts of amorphous resin, easily expands and changes in volume, so the conductive channels of the conductors break and the resistance increases. This phenomenon is identical to a change in volume (or a positive temperature coefficient) caused by heat. When the polymer resistor 44 comes into contact with the liquid chemical described above, the initial resistance value is not restored even if the liquid dries. Even if this value is restored, such recovery takes time.

In order to impart a moisture resistance property to the polymer resistor 44, a highly crystallized moisture resistant resin is added to the polymer resistor 44 such that the polymer composition 62 and the conductors 60, 61 partially chemically bond with this moisture resistant resin. As a result, even if the polymer resistor 44 comes into contact with the liquid chemical described above, the expansion of the polymer composition 62 does not occur.

The moisture resistant resin contains one of the components selected from the range including ethylene vinyl alcohol copolymer, thermoplastic polyester resin, polyamide resin, polypropylene resin, or ionomer, or combinations thereof can be used. These moisture resistant resins not only provide moisture resistance to the polymer resistor 44, but also help maintain the flexibility of the polymer composition 62. In other words, these moisture resistant resins support the flexibility of the polymer resistor 44.

The moisture resistant resin is added in an amount of preferably 10% by weight or more relative to the polymer composition 62 in the polymer resistor 44. Thereby, the moisture resistance of the polymer resistor 44 is increased. However, when a large amount of moisture resistant resin is present in the composition, the polymer resistor 44 hardens and its flexibility decreases. In addition, the conductors are trapped in a moisture-resistant resin, and the conductive channels break with difficulty, even with increasing temperature, and, as a result, the positive temperature coefficient decreases. Therefore, to maintain the flexibility of the polymer resistor and to create the desired positive temperature coefficient, the amount of the moisture-resistant resin is preferably 10-70% by weight, and optimally 30-50% by weight.

To test the effect of the above moisture resistant resins, the following test was conducted. First, a polymer resistor 44 was made that did not contain a moisture resistant resin, and a plurality of polymer resistors 44 containing, respectively, various moisture resistant resins (50% by weight). Drops of the above-described liquid chemicals were applied to these polymer resistors 44, which remained on the resistors for 24 hours. After applying 44 currents to these polymer resistors for 24 hours, they were left at room temperature for 24 hours. Before and after the test, the resistance values of these resistors were measured. It was found that polymer resistors 44 that did not contain a moisture-resistant resin showed a 200-300-fold increase in resistance compared to the value before the test.

On the contrary, in all polymer resistors 44 containing moisture-resistant resins, the increase in resistance was not more than 1.5-3-fold compared with the value before the test. This test showed that the addition of a moisture-resistant resin to the polymer resistor 44 prevents the expansion of the polymer composition 62 forming the polymer resistor 44, which may be caused by contact with a liquid chemical such as organic solvents or drinks. In other words, by adding a moisture-resistant resin to the polymer resistor 44, the resistance of the polymer resistor 44 can be stabilized, and the sheet heating element 40 can have high durability.

A pair of wire electrodes 42A 42B facing each other is arranged in two rows in the longitudinal direction of the sheet heating element 40. The polymer resistor 44 is located so as to overlap a pair of wire electrodes 42A, 42B, respectively. When electrodes 42A, 42B supply electricity to the polymer resistor 44, current flows through the polymer resistor 44 and the polymer resistor 44 heats up.

Wire electrodes 42 are sewn to the insulating substrate 42 with polyester thread 43 using a sewing machine. Therefore, the wire electrodes 42 are firmly attached to the insulating substrate 41, which allows you to change their shape along with a change in the shape of the insulating substrate 41, which increases the mechanical reliability of the sheet heating element.

The wire electrodes 42 are made of at least a metal conductive wire and / or twisted metal conductive wire, in which the metal conductors are twisted with each other. The material of the metal conductive wire may be copper, tinned copper, or an alloy of copper with silver. From the point of view of mechanical strength, it is preferable to use an alloy of copper with silver, since it has high tensile strength. In more detail, wire electrodes 42 are formed by twisting 19 copper-silver alloy wires having a diameter of 0.05 mm.

The resistance of the wire electrodes 42 should be as low as possible, and the voltage drop across the wire electrodes 42 should be small. The resistance of the wire electrodes 42 is selected so that the voltage drop applied to the sheet heating element is 1 V or less. In other words, preferably, the resistance of the wire electrodes 42 is 1 ohm / m or less. If the diameter of the wire electrodes 42 is large, these electrodes form bulges in the sheet heating element 40, and it becomes uncomfortable to sit on it. Therefore, their diameter should be 1 mm or less, and preferably 0.5 mm or less, so that it is even more convenient to sit on the heating element.

The distance between the wire electrodes 42A, 42B should be in the range of approx. 70-150 mm. For practical reasons, the distance between the wire electrodes 42A, 42B should be approx. 100 mm If the distance between the electrodes is less than 70 mm, then when a person sits on a sheet heating element 40 and his buttocks are pressed on the wire electrodes 42, it is likely that such a load and bending forces will lead to fracture or damage to the electrodes. On the other hand, if the distance between the electrodes is greater than 150 mm, the resistance of the polymer resistor 44 needs to be reduced to a very small value, which makes it difficult to produce a useful polymer resistor 44 with a positive temperature coefficient.

If the distance between the wire electrodes 42A, 42B is 70 mm, then since the film thickness of the polymer resistor 44 is 20-200 μm, and preferably 30-100 μm, the resistance of the polymer resistor 44 should be approx. 0.0016-0.016 ohm / m, preferably 0.0023-0.0078 ohm / m. In addition, if the distance between the wire electrodes 42A, 42B is 100 mm, the resistance of the polymer electrode 44 should be in the range of approx. 0.0011-0.011 ohm / m, preferably 0.0016-0.0055 ohm / m. In addition, if the distance between the wire electrodes 42A, 42B is 150 mm, the resistance of the polymer electrode 44 should be in the range of approx. 0.0007-0.007 ohm / m, preferably 0.0011-0.0036 ohm / m.

It should be noted that in this embodiment, a wire electrode is used as the electrode, but the present invention is not limited to this option, and a metal foil electrode or a membrane electrode obtained by screen printing with silver paste and the like can be used.

For the insulating substrate 41, needle-punched nonwoven fabric made from polyester fibers can be used. You can also use a fabric made of polyester fibers. The insulating substrate 41 provides the flexibility of the sheet heating element 40. The sheet heating element 40 can easily change its shape when exposed to an external force. Therefore, if it is used as a car seat heater, comfort is enhanced by its use. The sheet heating element has the same elongation properties as the seat upholstery material. More specifically, at a load of 7 kgfs or less, it stretches to a maximum of 5%.

As indicated above, the wire electrodes 42 are sewn to the insulating substrate 41. Due to sewing in the insulating substrate, holes remain pierced by the needle, but the above-described non-woven material or fabric prevents cracks in the holes from the needle.

The non-woven fabric or fabric made of polyester fibers has good ventilation properties and does not accumulate moisture when used as a car seat heater or a steering wheel heater. Therefore, even if you sit on it, or hold on to it for a long time, the initial feeling of comfort is preserved and remains very pleasant. And since when boarding the passenger there are no sounds like when landing on paper, the seat does not lose convenience, even if a sheet heating element 40 is installed inside it.

In addition, the insulating substrate 41, it is desirable to give the property of fire resistance, impregnating it with the above flame retardant composition. The flame retardant composition should be added in an amount of 5% by weight or more relative to the insulating substrate 41. However, with an increase in the amount of flame retardant added, the cost of manufacturing a sheet heating element 40 increases. In addition, the physical properties of the insulating substrate 41 are deteriorated. In view of this, the amount of the flame retardant added is preferably 10-30% by weight and optimally 15-25% by weight relative to the insulating substrate 41.

The sheet heating element may also have a moisture barrier film 45 of the type shown in FIG. 4C. The moisture barrier film 45 is adhered to the insulating substrate 41. The sheet heating element 40 shown in FIG. 4C are made as follows. First, using a T-shaped extruder, the moisture-proof resin is extruded in the form of a film onto an insulating substrate 41, forming a moisture-proof film 45. Then, wire electrodes 42A, 42B are placed on the moisture-proof film 45 and sewn onto the insulating substrate 41 and onto the moisture-proof film 45 thread 43. Then, an extruder with a T-shaped head is used to extrude the polymer resistor 44 in the form of a film applied to the moisture protective film 45. The polymer resistor 44 by thermal adhesion attaches the wire electrodes 42 to the moisture protective film 45 e.

The sheet heating element 40 is fixed so that the insulating substrate 41 is in contact with a place into which liquid chemicals can penetrate. Therefore, even if liquid chemicals penetrate the insulating substrate 41, it is protected by a moisture barrier 45 and the chemicals do not enter the polymer resistor 44. In other words, the moisture barrier 45 prevents contact between the chemicals and the polymer resistor 44. If the sheet heating element is provided with a moisture barrier 45, then the polymer resistor 44 may not have the property of moisture resistance.

The material of the moisture barrier film 45 may be an ethylene vinyl alcohol copolymer, a thermoplastic polyester resin, a polyamide resin, a polypropylene resin, or an ionomer, used alone or in combination.

From the point of view of flexibility of the sheet heating element 40, the moisture barrier 45 should be thin, but in order to maintain the moisture barrier, the thickness should be in the range of 50-100 μm. Taking into account productivity and prime cost, the thickness of 10-50 microns is optimal.

In addition, the above flame retardants can be added to the moisture barrier 45. The flame retardant is added in an amount of preferably 10-30% by weight and optimally 15-25% by weight relative to the moisture barrier 45.

In addition, the sheet heating element may be provided with a second insulating substrate 46 of the type shown in FIG. 4D. The sheet heating element according to FIG. 4D is made as follows. First, the wire electrodes 42A, 42B are laid symmetrically on the first insulating substrate 41 and, accordingly, partially sewn to it with a thread. 43. Then, using a T-shaped extruder, a polymer resistor 44 is formed on the second insulating substrate 46. Then, the first insulating substrate 41 and the second insulating substrate 46 are connected to each other by thermal adhesion using a device such as a laminator so that the wire electrodes 42 and polymer resistor 44 come into contact.

The second insulating substrate 46 is made of the same materials and according to the same specifications as the first substrate 41. The second insulating substrate 46 can also be impregnated with the above flame retardant. The amount of flame retardant should be 5% by weight or more relative to the insulating substrate 46, preferably 10-30% by weight, and optimally, 15-24% by weight.

Due to the fact that both sides of the sheet heating element 40 are coated with the first insulating substrate 41 and the second insulating substrate 46, respectively, the cushioning effect of the sheet heating element 40 itself is enhanced. Therefore, if the sheet heating element is used to heat the car seat, this element increases comfort. In addition, the second insulating substrate 46 protects the polymer resistor 44 from bumps and scratches.

Additionally, when the heating element is used as a car heater or under conditions in which the heating element is constantly exposed to external sliding force, the second insulating substrate 46 prevents abrasion and damage to the polymer resistor 44. Since the polymer resistor 44 is completely covered by two insulating substrates, the electrical insulating properties of the sheet heating element improve.

In addition, the sheet heating element 40 shown in FIG. 4C may have a second insulating substrate 46.

2 option sheet heating element

In FIG. 7A is a plan view of a heating element 70 according to a second embodiment of the present invention, and FIG. 7B is a sectional view taken along line 7B-7B of FIG. 7A. The design differs from the first embodiment (see FIG. 4A) in that the wire electrodes 71 are arranged on the insulating substrate 41 by wavy lines.

As shown in FIG. 7A, the wire electrodes 71 are arranged on the insulating substrate 41 by wavy lines and attached by a thread 43. According to this design, when external force is applied to the sheet heating element 70, since the wire electrodes 71 are arranged in wavy lines, having a margin in length, they easily change shape in response to stretching, stretching and bending. Therefore, the corrugated wire electrodes 71 have a mechanical strength with respect to an external force exceeding that of the wire electrodes 42 arranged in a straight line, as shown in FIG. 4A.

In addition, in those areas through which the wire electrodes 71 pass, the voltage supplied to the polymer resistor 44 becomes uniform, and the distribution of the heating temperature of the polymer resistor 44 also becomes uniform.

In addition, the sheet heating element 70 may have a moisture barrier 45 described for option 1 (see FIG. 7C). Wavy wire electrodes 71 are sewn onto a moisture barrier film 45 on an insulating substrate 41 by a thread 43.

Additionally, the sheet heating element may have a second insulating substrate 46 described for option 1 (see FIG. 7D). A sheet heating element 70 coated with a second insulating substrate 76, as shown in FIG. 7D may also have the moisture barrier film shown in FIG. 7C.

3 option sheet heating element

FIG. 8A is a plan view of a sheet heating element according to a third embodiment of the present invention, and FIG. 8B is a section along line 8B-8B in FIG. 8A. The design differs from the first embodiment (Fig. 4A) in that auxiliary wire electrodes 81 are located between the pair of wire electrodes 42. In other words, auxiliary wire electrodes 81 are located between the pair of wire electrodes and sewn to the insulating substrate 41 by a sewing machine using thread 82 made made of polyester fibers and the like, as is the case with wire electrodes 42.

In the structure shown in FIG. 4A, the polymer resistor 44 tends to heat unevenly between the electrodes 42, and the resistance of this portion grows, concentrating the electric potential on it. If this condition continues, the temperature of this part of the polymer resistor 44 rises more than on other parts, which leads to the appearance of the so-called hot line phenomenon. Using auxiliary wire electrodes 81, as shown in FIG. 8A, the electric potential is evenly distributed throughout the polymer resistor 44, so that the heating temperature becomes uniform. Therefore, the occurrence of a hot line phenomenon in the portion of the polymer resistor 44 can be prevented.

It should be noted that, like the wire electrodes 42, the auxiliary wire electrodes 81 are made of metal wire or twisted metal wire.

In FIG. 8A and 8B show two auxiliary wire electrodes 81 located between a pair of wire electrodes 42. However, the number of auxiliary wire electrodes 81 is not limited to this, and this number can be determined in accordance with the size of the polymer resistor 44, the distance between the electrodes 42 and the desired heat distribution.

In FIG. 8A, the auxiliary wire electrodes are located almost parallel to the pair of wire electrodes 42. However, the arrangement is not limited to this, and the auxiliary wire electrodes 81 can also extend in a zigzag configuration between the pair of wire electrodes 42.

In addition, the auxiliary wire electrodes can be laid in a wavy configuration as wire electrodes 71 in the second embodiment shown in FIG. 72A and 72B. Of course, the corrugated wire electrodes 71 and the corrugated auxiliary electrodes 81 can be combined with each other.

The sheet heating element 80 may have a moisture barrier 45 described for the first embodiment (see FIG. 8C). The wire electrodes 42 and the auxiliary wire electrodes 81 are sewn to the moisture barrier film 45 and to the insulating substrate 41 by threads 43 and 82.

Additionally, the sheet heating element 80 may have a second insulating substrate 46 described for the first embodiment (see FIG. 8D). Such a configuration may also have a moisture barrier film 45 shown in FIG. 8C, as well as the second insulating substrate shown in FIG. 8D.

4 option sheet heating element

In FIG. 9A is a plan view of a sheet heating element 90 according to a fourth embodiment of the present invention. In FIG. 9B is a sectional view taken along line 9B-9B of FIG. 9A. This design differs from the first embodiment (see FIG. 4A) in that the polymer resistor 44 is installed by introducing it between the insulating substrate and the wire electrodes 42.

The sheet heating element 90 according to the fourth embodiment of the present invention is made as follows. First, a film-shaped polymer resistor 44 is applied by hot lamination to an insulating substrate 41. Then, wire electrodes 42 are laid onto the polymer resistor 44 and sewn onto the substrate 41 using a sewing machine. The wire electrodes 42 and the polymer resistor 44 are compressed while heating so that the wire electrodes 42 glued to the polymer resistor 44. Since the wire electrodes 42 are located on the polymer resistor 44, their location can easily be checked. When the central portion of the insulating substrate 41 is perforated to increase flexibility, the penetration of wire electrodes 42 can be reliably prevented.

In addition, since the wire electrodes 42 are sewn to the insulating substrate 41 to which the polymer resistor 44 is already attached, there is greater freedom of arrangement of the wire electrodes 42. It is possible to easily produce a variety of sheet heating elements 90, making the process of attaching the polymer resistor 44 to the insulating substrate 41 a common process whereupon the electrodes 42 can be sewn in various configurations to obtain different patterns of heating.

In addition, in this embodiment, auxiliary wire electrodes 81 shown in FIG. 8A.

In this embodiment, the wire electrodes 42 and the polymer resistor 44 undergo thermal adhesion. But the present invention is not limited to this. Wire electrodes 42 and polymer resistor 44 can also be bonded using electrically conductive glue. The wire electrodes 42 and the polymer resistor 44 can also be electrically connected by mechanical contact, simply pressing them against each other.

The sheet heating element 90 may also have a moisture barrier 45 described for option 1 (see FIG. 9C). A film-shaped polymer resistor 44 is laminated to a moisture-proof film 45, and then wire electrodes 42 are sewn onto an insulating substrate 41 through a polymer resistor 44 and a moisture-proof film 45.

The sheet heating element 90 may also have a second insulating substrate 46 described for option 1 (see FIG. 9D). Additionally, the sheet heating element 90 shown in FIG. 9D may have the moisture barrier film shown in FIG. 9C located between the polymer resistor 44 and the first insulating substrate 41.

5 option sheet heating element

In FIG. 10A is a plan view of a sheet heating element 100 according to a fifth embodiment of the present invention. In FIG. 10B is a sectional view taken along line 10B-10B of FIG. 10A. This design differs from the fourth embodiment (see Fig. 9A) in that there are electrically conductive strips 101 between the polymer resistor 22 and the wire electrodes 42, along which the wire electrodes 42 slide.

The sheet heating element 100 according to the fifth embodiment is made as follows. The film-shaped polymer resistor 44 is laminated to an insulating substrate 41. Then, the conductive strips 101 are attached to this polymer resistor 44. Then, the wire electrodes 42 are laid on the conductive strips 101 and sewn onto the insulation substrate 41 through the conductive strips 101 and the polymer resistor 44. The wire electrodes 42 and the polymer resistor 44 are compressed when heated so that the polymer resistor 44 adheres firmly to the wire electrodes 42.

The electrical conductive strips 101 are formed, for example, from a film obtained from dried graphite paste or from a film obtained from a resin containing graphite. When the conductive strips 101 are mounted on the polymer resistor 44, they are hot-laminated to the polymer resistor 44, or applied in the form of a paint.

Since the wire electrodes 42 can slide along the conductive strips 101, the flexibility of the sheet heating element is further enhanced. Since the conductive strips 101 have excellent conductivity, the wire electrodes 42 and the polymer resistor 44 are more reliably electrically connected through the conductive strips 101.

It should be noted that in this embodiment, auxiliary electrodes 81 according to the third embodiment can also be additionally used (see Fig. 8A). In addition, conductive strips 101 can be performed for auxiliary electrodes 81.

In this embodiment, the conductive strips are attached to the polymer resistor 44 after gluing the polymer resistor 44 to the insulating substrate 41. But the conductive strips 101 can be attached to the polymer resistor 44 in advance.

Wire electrodes 42 and polymer resistor 44 are connected by thermal adhesion. However, the present invention is not limited to this. The wire electrodes 42 and the polymer resistor 44 can be electrically connected to each other by mechanical contact by simply squeezing them together.

The sheet heating element 100 may also have a moisture barrier 45 described above for the first embodiment (see FIG. 10C). A polymer film resistor 44 is applied by hot lamination to a moisture barrier film 45. Then, conductive strips 101 are applied to the polymer resistor 44. Wire electrodes 42 are sewn to the insulating substrate 41 through the conductive strips 101, the polymer resistor 444, and the moisture barrier film 45.

The sheet heating element 100 may be provided with a second insulating substrate 46, as shown in FIG. 10D. A hot film-coated polymer resistor 44 is applied to the second insulating substrate 46 by hot lamination. Then, conductive strips 101 are attached to the polymer resistor 44. On the other hand, wire electrodes are sewn to the first insulating substrate 41. Then, the second insulating substrate 46 is connected to the first insulating substrate 41 by thermal compression so that the wire electrodes 42 come into contact with the conductive strips 101, forming a node.

6 option sheet heating element

In FIG. 11A is a plan view of a sheet heating element according to a sixth embodiment of the present invention. In FIG. 11B is a sectional view taken along line 11B-11B of FIG. 11A. This design differs from the fourth embodiment (see FIG. 9A) in that instead of the polymer resistor 44, a polymer resistor 111 is used. The polymer resistor 111 is obtained by impregnating a mesh non-woven material or fabric with a polymer resistor.

The sheet heating element 110 according to the sixth embodiment of the present invention is made as follows. Get ink by dispersing and mixing the polymer resistor described for 1-5 options, in a liquid, for example, in a solvent. The mesh non-woven fabric or fabric is impregnated with these inks in such ways as, for example, by printing, dyeing, dipping, etc., and dried to obtain a polymer resistor 111. The mesh non-woven fabric or fabric has many small pores between the fibers, and into these pores Resin penetrates the resin.

Next, wire electrodes 42 are placed on the polymer resistor 111 and sewn with a sewing machine to the insulating substrate 41. Then, the polymer resistor 111 is glued to the insulating substrate 41 by hot lamination. The wire electrodes 42 and the polymer resistor 111 are thermally compressed so that the polymer resistor 111 adheres firmly to the wire electrodes 42.

In this design, since the polymer resistor 111 is made of a mesh non-woven material or fabric having many pores, it has great flexibility since it can easily change shape under the influence of an external force.

Since the polymer resistor is held in the pores of the nonwoven material or fabric, the polymer resistor 111 adheres tightly to the insulating substrate 41, thereby increasing the mechanical strength of the polymer resistor 111.

It should be noted that in this embodiment, the mesh non-woven material or fabric is impregnated with an ink type polymer resistor. The net nonwoven fabric or fabric may also be thermally compressed to impregnate it with a film or sheet type polymer resistor.

Additionally, in this embodiment, the wire electrodes 42 and the polymer resistor 111 are connected by thermal adhesion. However, the present invention is not limited to this. The wire electrodes 42 and the polymer resistor 111 may be bonded with an electrically conductive adhesive. The wire electrodes 42 and the polymer resistor 111 can also be electrically connected by mechanical contact while compressing them with each other.

In addition, in this embodiment, auxiliary electrodes 81 described for the third embodiment can be used (see FIG. 8A).

The sheet heating element 110 may also have a moisture barrier 45 described for the first embodiment of the present invention (see FIG. 11C). The polymer resistor 111 and the moisture barrier film 45 are glued together by lamination.

The sheet heating element 110 may be provided with a second insulating substrate 46, as shown in FIG. 11D. The nonwoven fabric or mesh fabric is impregnated with the polymer resistor material to form the polymer resistor 111. The polymer resistor 111 and the second insulating substrate 46 are bonded by hot lamination. The wire electrodes 42 are sewn with a sewing machine to the first insulating substrate 41. The first and second insulating pads 41, 46 are connected to each other by thermal compression so that the wire electrodes 42 come into contact with the polymer resistor 111.

The sheet heating element 110 may be provided with a second insulating substrate, as shown in FIG. 11C.

7 option sheet heating element

In FIG. 12A is a plan view of a sheet heating element 120 according to a seventh embodiment of the present invention. In FIG. 12B is a sectional view taken along line 12AB-12B of FIG. 12A. This design differs from the first embodiment (see Fig. 4A) in that the polymer resistor 44 additionally has a coating layer 121.

The covering layer 121 is formed of a material having electrical insulating properties. After hot lamination of the polymer resistor 44 on the insulating substrate 41, to which the wire electrodes 42 are pre-attached, a coating layer 121 is also fastened to the polymer resistor 44 by hot lamination to close this polymer resistor 44.

The main component of the cover layer 121 is either a polyolefin-based thermoplastic elastomer, or a styrene-based thermoplastic elastomer, or a urethane-based thermoplastic elastomer. The thermoplastic elastomer gives flexibility to the sheet heating element 120.

The cover layer 121 protects the sheet heating element 120 from bumps and scratches that can damage the sheet heating element 120.

Furthermore, when the heating element is used as a car seat heater, or in such conditions when it is constantly exposed to an external force causing it to slide, the coating layer 121 prevents the polymer resistor 44 from being abraded so that the sheet heating element does not lose its heat emission function.

In addition, since the heating element 120 is electrically isolated, it is safe even if a high voltage is applied to it.

The covering layer 121 should cover the polymer resistor 44 completely. However, given the flexibility, it is preferable to use a thin coating layer 121.

The sheet heating element 120 may also have a moisture barrier film 45 described for the first embodiment (see FIG. 12C). The moisture-protective film 45 is applied by hot lamination to the insulating substrate 41. The wire electrodes 42 are sewn onto the insulating substrate 41 through the moisture-proof film 45. After lamination of the polymer resistor 44, the coating layer 121 is laminated to the moisture-proof film 45.

8 option sheet heating element

In FIG. 13A is a plan view of a sheet heating element 130 according to an eighth embodiment of the present invention, and FIG. 13B is a sectional view taken along line 13B-13B of FIG. 13A. This design differs from the first embodiment (see FIG. 4A) in that at least either the insulating substrate 41 and / or the polymer resistor 44 is provided with a plurality of slots 131.

The sheet heating element 130 of the eighth embodiment is made as follows. First, as in the first embodiment, the wire electrodes 42 are placed on an insulating substrate 41 and sewn to it. Using a T-shaped extruder, a polymer resistor 44 in the form of a film or sheet is extruded onto an insulating substrate 41 and attached to it by thermal adhesion. After perforating the central part of the insulating substrate 41 to form elongated holes, a Thomson punch stamp is used to form a plurality of slots 131 in the polymer resistor 44 and in the insulating substrate.

The areas punched by the Thomson punch stamp are not limited to those shown in the drawing. Depending on the shape of the upholstery 53 of the car seat, punching can be performed in other places than those shown in the drawing. In this case, it may be necessary to change the route of the wire electrodes 42.

In addition, the wire electrodes 42 and the polymer resistor 44 can be attached to an insulating substrate 41, on which slots 131 have already been formed, punched with a Thomson piercing stamp. Alternatively, the polymer resistor 44 may be attached to a separator, such as polypropylene or in the form of mold release paper (not shown). Then, before attaching the polymer resistor to the insulating substrate 41, the slots 131 are made in the polymer resistor 44. In the first case, the slots 131 are made only in the insulating substrate 41, and in the latter case, the slots 131 are made only in the polymer resistor 44.

Since a plurality of slots 131 are made in the sheet heating element 130 of this embodiment of the present invention, this sheet heating element 130 can easily change shape in response to an external force such that when it is seated, the feeling of comfort is enhanced. The elongated hole formed in the central part of the insulating substrate 41 can also be considered to give flexibility to the sheet heating element 130. However, the elongated hole is designed to attach the sheet heating element 130 to the seat and is not intended to give flexibility to this heating element 130. Therefore, it should be functionally distinguished with slots 131.

It should be noted that the slots 131 in this embodiment can also be formed in sheet heating elements in 1-7 variants.

The sheet heating element 130 may also have a moisture barrier 45 described for the first embodiment (see FIG. 13C). First, the wire electrodes 42 are sewn onto the insulating substrate 41 through a moisture barrier film 45, as in the first embodiment. Using a T-shaped extruder, a film-shaped polymer resistor 44 is extruded onto an insulating substrate 41 and attached thereto by thermal adhesion. After punching the central part of the insulating substrate 41 to form a plurality of slots 131 between the wire electrodes 42 passing from the polymer resistor 44 through the insulating substrate 41, a Thomson punch stamp is used.

The sheet heating element 130 may be provided with a second insulating substrate 46, as shown in FIG. 13D. First, wire electrodes 42 are sewn onto the first insulating substrate 41. Then, using a T-shaped extruder, the polymer resistor 44 in the form of a film or sheet is extruded onto the second insulating substrate 46 and attached to it by thermal adhesion. The first and second insulating substrates 41, 46 are connected to each other by thermal compression so that the wire electrodes 42 and the polymer resistor 44 come into contact with each other. After punching the center portion of the first insulating substrate 41 and the second insulating substrate 46, a Thomson punch stamp is used to form slots 131 passing through the first insulating substrate, the polymer resistor 44, and the second insulating substrate 46.

Slots 131 can be formed in advance by punching the first and second insulating substrates 41, 46 with a Thomson punch stamp. Alternatively, the polymer resistor 44 can be attached to a separator, for example of polypropylene, or in the form of release paper for molds (not shown), and slots 131 can only be formed in insulating substrates 41, 46 by punching. In the first case, the slots 131 are formed only in the insulating substrates 41, 46, and in the latter case, the slots 131 are formed only in the polymer resistor 44.

9 option sheet heating element

In FIG. 14A is a plan view of a sheet heating element 140 according to a ninth embodiment of the present invention. In FIG. 9B is a sectional view taken along line 14B-14B of FIG. 14A. This design differs from the eighth embodiment (see FIG. 13A) in that instead of the slots 131, a plurality of cuts 141 are made therein.

The sheet heating element 140 according to the ninth embodiment of the present invention is made as follows. First, the polymer resistor 44 is attached to a separator made of polypropylene or mold release paper (not shown), and punched to form notches 141. Next, the polymer resistor 44 is hot-laminated to an insulating substrate 41 to which corrugated wire is already sewn electrodes 71, and then the separator is removed from the polymer resistor 44.

Since the polymer resistor 44, due to the notches 141, easily changes shape in response to an external force applied, the feeling of comfort for the seated person is enhanced.

In addition, similar incisions 141 can be made in the insulating substrate 41. In this case, these incisions 141 make a significant contribution to the above function, allowing you to further increase the comfort for the sitting.

The incisions 141 of this embodiment can also be made in sheet heating elements according to 1-7 variants.

The sheet heating element may also have a moisture barrier 45 described for option 1 (see FIG. 14C). First, the wire electrodes 71 are sewn to the insulating substrate 41 through a moisture-proof film 45. The polymer resistor 44 is attached to a separator of polypropylene or mold release paper (not shown) and punched to form cuts 141 in the polymer resistor 44. Using a hot laminator, the polymer resistor 44 attached to a moisture barrier film 45, and then the separator is removed.

The sheet heating element 140 may be provided with a second insulating substrate 46, as shown in FIG. 14D. First, the polymer resistor 44 is attached to a separator of polypropylene or mold release paper (not shown) and punched to form cuts 141 in the polymer resistor 44. After hot lamination of the polymer resistor onto the second insulating substrate 46, the separator is removed. On the other hand, the corrugated wire electrodes 42 are sewn to the first insulating substrate 41. Then, the first and second insulating substrates are joined by thermal compression using a hot laminator, so that the wire electrodes and the polymer resistor 44 come into contact with each other, forming a node.

The sheet heating element 140, as shown in FIG. 14C may have a second insulating substrate 46.

Industrial applicability

The sheet heating element of the present invention has a simple structure, excellent positive temperature coefficient characteristics, and flexibility allowing it to easily change shape in response to external force. Since such a sheet heating element can be attached to the surface of household appliances having a complex topography of the surface, it can be used as a heater for car seats and steering wheels, as well as in household appliances such as electric floor heaters. In addition, high production productivity and low cost give a wide range of applications.

Items in the drawings

10, 30, 40, 70, 80, 90, 100, 120, 130 and 140 - sheet heating element

11, 31, 41 - substrate

12, 13, 32, 33, 42, 71, 81 - wire electrodes

14, 34, 44, 111 - polymer resistor

15, 35, 121 - covering layer

20, 21 - hot roll

22 - laminator

43, 82 - thread

45 - moisture protective film

46 - second insulating substrate

50 - seat

51 - backrest

52 - seat base material

53 - seat upholstery

60 - fine conductor

61 - fiber conductor

62 - resin composition

101 - conductive strip

131 - slot

141 - notch.

Claims (60)

1. A sheet heating element comprising:
a backing sheet made of an insulating material;
wires made of electrically conductive material and located at a distance from each other on a substrate sheet; and
at least one sheet of a resistor with a positive temperature coefficient in electrical contact with the wires, and configured to heat with self-regulation in response to the electric current supplied through the wires,
wherein at least one positive temperature coefficient resistor sheet comprises a resin composition and an electrically conductive material, the resin composition comprising a reactant resin and a reactive resin crosslinked with the reactant resin. 2. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient has a thickness of 20-200 microns. 3. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient has a thickness of 30-100 μm. 4. The element according to claim 1, in which the electrically conductive material is at least one of a series comprising at least soot and graphite. 5. The element according to claim 1, in which at least one sheet of a resistor with a positive, temperature coefficient is thermally fusible to create electrical contact with the wires. 6. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient has an electrical resistance in the range from 0.0007 to 0.016 Ohm · m 7. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient has an electrical resistance in the range from 0.0011 to 0.0078 Ohm · m. 8. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient contains a flame retardant. 9. The element of claim 8, in which the flame retardant composition contains at least one of a series including a phosphorus-based flame retardant, a nitrogen-based flame retardant, a silicon-based flame retardant, an inorganic flame retardant, and a halogen-based flame retardant. 10. The element of claim 8, in which at least one sheet of a resistor with a positive temperature coefficient satisfies at least one of the following conditions:
(a) when the end of this at least one positive temperature coefficient resistor sheet is fired by a gas burner flame, and the gas burner flame goes out after 60 seconds, this at least one positive temperature coefficient resistor sheet does not burn even if it is carbonized.
(b) when the end of this at least one sheet of resistor with a positive temperature coefficient is fired by a gas burner flame, this at least one sheet of resistor with a positive temperature coefficient burns for no more than 60 s, but the flame goes out within 2 inches (50.8 mm ), or
(c) when the end of this at least one sheet of resistor with a positive temperature coefficient is fired by a flame of a gas burner, even if this at least one sheet of resistor with a positive temperature coefficient is ignited, the flame does not propagate faster than 4 inches (101.6 mm) per minute, on an area 1/2 inch (12.7 mm) thick from the surface. 11. The element of claim 8, in which the flame retardant is contained in at least one sheet of a resistor with a positive temperature coefficient in the amount of 5 wt.% Or more. 12. The element of claim 8, in which the flame retardant is contained in at least one sheet of a resistor with a positive temperature coefficient in the amount of 10-30 wt.% Or more. 13. The element of claim 8, in which the flame retardant is contained in at least one sheet of a resistor with a positive temperature coefficient in the amount of 15-25 wt.% Or more. 14. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient contains a moisture resistant resin. 15. The element according to 14, in which the moisture-resistant resin is contained in at least one sheet of a resistor with a positive temperature coefficient in the amount of 10 wt.% Or more. 16. The element according to 14, in which the moisture-resistant resin is contained in at least one sheet of a resistor with a positive temperature coefficient in the amount of 10-70 wt.%. 17. The element according to 14, in which the moisture-resistant resin is contained in at least one sheet of a resistor with a positive temperature coefficient in the amount of 30-50 wt.%. 18. The item 14, in which the waterproof resin contains at least one of a series including a copolymer of ethylene vinyl alcohol, a thermoplastic polyester resin, a polyamide resin, a polypropylene resin and an ionomer. 19. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient is heated with self-regulation to a temperature of from about 40 to about 45 ° C. 20. The element according to claim 1, in which the wires are sewn to the substrate sheet. 21. The element according to claim 1, in which the wires have a diameter equal to 1 mm or less. 22. The element according to claim 1, in which the wires have a diameter equal to 0.5 mm or less. 23. The element according to claim 1, in which the wires have a resistance of 1 Ohm / m or less. 24. The element according to claim 1, in which the electrically conductive material from which the wires are formed is one of a series including copper, tinned copper and an alloy of copper and silver. 25. The element according to claim 1, in which the wires are formed by twisting each other 19 wires of an alloy of copper with silver with a diameter of 0.05 mm 26. The element according to claim 1, in which the wires are spaced 70-150 mm apart. 27. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient has an elasticity equal to or greater than the elasticity of the substrate sheet. 28. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient is stretched by more than 5% at a load of less than 7 kgf. 29. The element according to claim 1, in which the substrate sheet is made of non-woven material or fabric made of polyester fibers. 30. The element of claim 28, wherein the substrate sheet is needle punched. 31. The element according to claim 1, further comprising a coating sheet made of electrical insulating material and interacting with the substrate sheet to cover the wires and at least one sheet of resistor with a positive temperature coefficient. 32. The item according to p, in which the coating sheet is made of non-woven material or from a fabric formed from polyester fibers. 33. The element according to p, in which at least one of the substrate sheet and the coating sheet contains a flame retardant. 34. The element according to p. 33, in which the flame retardant composition contains at least one of a series including a phosphorus-based flame retardant, a nitrogen-based flame retardant, a silicon-based flame retardant, an inorganic flame retardant and a halogen-based flame retardant. 35. The element according to p, in which at least one of the substrate sheet and the coating sheet meets at least one of the following conditions:
(a) when the end of this at least one of the substrate sheet or the coating sheet is fired by a gas burner flame, and the gas burner flame goes out after 60 seconds, this at least one sheet does not burn, even if it is charred.
(b) when the end of this at least one of the substrate sheet or the coating sheet is burned with a gas burner flame, this sheet burns for no more than 60 s, but the flame goes out within 2 inches (50.8 mm), or
(c) when the end of this at least one of the substrate sheet or the coating sheet is fired by a gas burner flame, even if this sheet is ignited, the flame does not propagate faster than 4 inches (101.6 mm) per minute over an area 1/2 inches (12.7 mm) from the surface. 36. The element according to p, in which the flame retardant is contained in one of at least a substrate sheet and a coating sheet in an amount of 5 wt.% Or more. 37. The element according to p. 33, in which the flame retardant is contained in one of at least a substrate sheet and a coating sheet in an amount of 10-30 wt.% Or more. 38. The element according to p. 33, in which the flame retardant is contained in one of at least a substrate sheet and a coating sheet in an amount of 15-25 wt.% Or more. 39. The element according to claim 1, in which the wires are located between at least one film resistor with a positive temperature coefficient and the substrate sheet. 40. The element according to claim 1, further containing a waterproof film. 41. The element of claim 40, wherein the moisture barrier film comprises at least one member of a series comprising a copolymer of ethylene vinyl alcohol, a thermoplastic polyester resin, a polyamide resin, a polypropylene resin, and an ionomer. 42. The element of claim 40, wherein the moisture barrier film has a thickness of 5-100 microns. 43. The element of claim 40, wherein the moisture barrier film has a thickness of 10-50 microns. 44. The element of claim 40, wherein the moisture barrier film is positioned between at least one positive temperature coefficient resistor sheet and a substrate sheet. 45. The element of claim 40, wherein the moisture barrier film comprises a flame retardant composition. 46. The element according to item 45, in which the flame retardant composition contains at least one of a series comprising a phosphorus-based flame retardant, a nitrogen-based flame retardant, a silicon-based flame retardant, an inorganic flame retardant and a halogen-based flame retardant . 47. The element according to item 45, in which the moisture-proof film meets at least one of the following conditions:
(a) when the end of the moisture barrier film is burned with the flame of a gas burner and the flame of the gas burner goes out after 60 seconds, this moisture barrier film does not burn, even if it is charred.
(b) when the end of the moisture barrier film is burned with the flame of a gas burner, the moisture barrier film burns for no more than 60 s, but the flame goes out within 2 inches (50.8 mm), or
(c) when the end of the moisture barrier film is burned with a flame of a gas burner, even if this moisture barrier film is ignited, the flame does not propagate faster than 4 inches (101.6 mm) per minute over an area 1/2 inch (12.7 mm) thick from surface. 48. The element according to item 45, in which the flame retardant is contained in a moisture-proof film in an amount of 5 wt.% Or more. 49. The element according to item 45, in which the flame retardant is contained in a moisture barrier film in an amount of 10-30 wt.% Or more. 50. The element according to item 45, in which the flame retardant is contained in a moisture barrier film in an amount of 15-25 wt.% Or more. 51. The element according to claim 1, in which at least one wire passes along a wavy path. 52. The element according to claim 1, in which the wires are arranged so that on each of at least one sheet of a resistor with a positive temperature coefficient, more than two wires are supplied with electricity. 53. The element according to claim 1, in which at least one sheet of a resistor with a positive temperature coefficient is located between the wires and the substrate sheet. 54. The element according to claim 1, further containing conductive films located between the wires and at least one sheet of resistor with a positive temperature coefficient, which allows the wires to slide on these films. 55. The element according to item 54, in which the conductive film is made of graphite paste or resin containing graphite. 56. The element according to claim 1, in which at least one sheet of the resistor with a positive temperature coefficient contains non-woven material or fabric impregnated with the material of the resistor with a positive temperature coefficient. 57. The element according to claim 1, further comprising a coating film made of a thermoplastic elastomer. 58. The element according to clause 57, in which the coating film is made of at least one element from the series, including a thermoplastic elastomer based on a polyolefin, a thermoplastic elastomer based on styrene, and a thermoplastic elastomer based on urethane. 59. The element according to claim 1, in which a lot of slots are made in the substrate sheet and in the resistor sheet with a positive temperature coefficient. 60. The element according to claim 1, in which a lot of cuts are made in the substrate sheet and in the resistor sheet with a positive temperature coefficient.

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