JPH06349568A - Sheet-like heat generating body - Google Patents

Abstract

PURPOSE:To provide a heat generating body having excellent corrosion resistance and stability, and of light weight by using carbon fibers of continuous filaments of which specific electric resistance is specified in a sheet-like heat generating body using the carbon fibers for an electric resistance body. CONSTITUTION:Carbon fibers of polyacrylonitrile continuous filaments having a specific electric resistance of 10<-3>OMEGA.cm are paralleled in one direction to form an ultra-thin sheet of a thickness of 10mum. Next, an epoxy resin film of 10g/mm<2> Metsuke is applied to this sheet to be impregnated, except for end part surfaces of the sheet. A copper foil of 10mm wide and 0.1mm thick is then installed on the end part surface where epoxy resin is not yet impregnated, and an epoxy resin-impregnated prepreg of glass fiber fabric of 0.1mm is laminated on each surface of its as a reinforcement member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically heated sheet heating element.

[0002]

2. Description of the Related Art In recent years, in pursuit of beautification and comfort of living spaces, chairs used outdoors and in cold places,
There is an increasing demand for the application of sheet heating elements because it is necessary to keep the desks and furniture warm, and to keep the mirror warm in bathrooms and washrooms.

[0003]

However, in the conventional sheet heating element, the electric resistor is a metal type resistor or a carbon black type resistor, and these electric resistors have durability, stability and weight. There is a limit in terms of thickness, etc. It is an object of the present invention to provide a lightweight and thin planar heating element having excellent corrosion resistance and stability.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a heating element using carbon fiber as an electric resistor, wherein a continuous filament carbon fiber having an electric resistivity of 10 ⁻⁴ to 10 ⁻² Ω · cm is an extremely thin sheet. The sheet-shaped heating element is arranged in a fixed shape and fixed with an insulating binder, and a conductor electrode is integrally bonded to an end of the sheet-shaped material.

The electric resistor of the heating element in the present invention may be a polyacrylonitrile type or a pitch type, but a continuous filament carbon fiber having an electric resistivity of 10 ⁻⁴ to 10 ⁻² Ω · cm is used. . In continuous filament carbon fiber, it is necessary to arrange filaments into an extremely thin sheet by opening or the like, and the thickness of the sheet is 10 to 2
The thickness may be set to 00 μ, and may be processed into a strip shape and joined in parallel or series if necessary. Further, the sheet-like material may be in the form of an extremely thin woven fabric or a braid, as long as the filament arrangement state is maintained.

In the present invention, the use of the continuous filament carbon fiber as an electric resistor causes bending deformation due to the continuous filament carbon fiber being a long continuous body.
Even after repeated moisture absorption and drying, there is no change in electric resistance as in the case of using carbon black or short fibers of carbon fiber, and it can withstand outdoors or high humidity environment.

In the present invention, the ultrathin sheet-like material is fixed with an insulating binder, and the insulating binder is preferably a thermosetting resin such as epoxy resin, phenol resin, unsaturated polyester resin, or silicone rubber. Can be used. As the insulating binder, it is also possible to use rubber or a thermoplastic resin in combination within a range where heat resistance can be maintained. Further, if necessary, a material such as glass fiber may be contained, and when the glass fiber ultra-thin fabric is used for compounding, the entire heating element can be provided as a hybrid compound to provide rigidity and durability.

The fixing of the ultra-thin sheet-like material with the insulating binder can be performed by impregnating the ultra-thin sheet-like material with a liquid insulating binder and heating it. The conductor electrode may be placed in contact with the end portion, that is, the end portion of the array filament, and may be integrally bonded by heating, or a film-like insulating binder or liquid may be applied to the conductor electrode in contact with the ultra-thin sheet material. Simultaneous heat molding may be carried out using the above insulating binder.

The heating capacity of the sheet heating element is proportional to the conductivity per unit width of the heating element and the square of the voltage, and is inversely proportional to the square of the length of the heating element. The thickness is changed, and the conductor electrodes are arranged and coupled so that the strips of the sheet-like material are arranged in series or in parallel.

The conductor electrode used is not preferably a material that forms a local battery by coming into contact with carbon fiber and corrodes. A foil or plate of copper, brass, stainless steel or the like having good corrosion resistance is not preferable. A thin plate of carbon fiber reinforced resin, which is preferable, can also be used.

The sheet heating element of the present invention also functions as a carbon fiber reinforced resin plate. In addition, in order to reinforce the entire structure, it is also possible to use an insulating fiber reinforcing material such as glass fiber woven fabric or aramid fiber woven fabric together to reinforce and laminate them to improve electric leakage resistance. It can be appropriately adopted depending on the application of the body.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples.

(Embodiment 1) Electric resistivity is 10 ⁻³ Ω · cm
Polyacrylonitrile-based continuous filament carbon fibers are aligned in one direction to form an ultra-thin sheet with a thickness of 10μ, and an epoxy resin film with a basis weight of 10 g / mm ² is attached to this ultra-thin sheet leaving the end surface of the sheet. And impregnated. Then, a copper foil having a width of 10 mm and a thickness of 0.1 mm is arranged on the end surface not impregnated with the epoxy resin, and a 0.1 mm-thick glass fiber fabric epoxy resin impregnated prepreg is used as a reinforcing material on both sides of the sheet containing the copper foil. The sheets were further laminated and thermoformed in an autoclave to obtain a sheet heating element. When a connection terminal was provided on the copper foil portion of this sheet heating element and set to a power source, as shown in Table 1, various heating capabilities were obtained.

[0014]

[Table 1]

(Embodiment 2) Electric resistivity is 10 ^-3 Ω · cm
Polyacrylonitrile-based continuous filament carbon fibers are aligned in one direction to form an ultra-thin sheet with a thickness of 20μ, and an epoxy resin film with a basis weight of 30 g / mm ² is attached to this ultra-thin sheet leaving the end surface of the sheet. And impregnated. Next, a stainless steel sheet having a width of 10 mm and a thickness of 0.1 mm was placed on the end surface not impregnated with the epoxy resin, and heat-molded in an autoclave to obtain a planar heating element. This sheet heating element was laminated and simultaneously molded at the time of forming a seat mold compound of a chair for exterior bleachers to obtain a chair capable of keeping heat.

[0016]

INDUSTRIAL APPLICABILITY The sheet heating element of the present invention exhibits heat retention and anti-fog effects by being attached to chairs, desks, furniture, or in the vicinity of mirrors, and resin molded articles such as chairs. If it is integrally attached at the time of molding, it will also have a reinforcing effect. Since the sheet heating element of the present invention can be made thin, it can be deformed and can follow a curved surface.
In addition, even in the outdoors, cold or high humidity environment, there is no change in electric resistance, deterioration does not occur, and stability is excellent.

Claims (4)

[Claims] 1. A heating element using carbon fibers as an electric resistor, wherein continuous filament carbon fibers having an electric specific resistance of 10 ⁻⁴ to 10 ⁻² Ω · cm are arranged in an ultrathin sheet to form an insulating binder. And a conductor heating element integrally fixed to the end of the sheet-like material. 2. The sheet heating element according to claim 1, wherein the insulating binder is a thermosetting resin. 3. The sheet heating element according to claim 1, wherein the conductor electrode is a plate or foil made of a corrosion resistant metal. 4. The sheet heating element according to claim 1, wherein the insulating fiber reinforcing material is laminated on the heating element.