JPS62168376A - Panel heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sheet heating element that utilizes electrical energy, and is suitable for use as a heat source for heat utilization equipment such as space heaters, cookers, and dryers, particularly as a radiant heating source. This is what we provide.

In particular, the planar heating element K + 3! is a sheet heating element formed in a desired circuit shape such as a meandering shape or a spiral shape, which is attached to a heat-resistant prepreg and bonded under heat. J.

BACKGROUND OF THE INVENTION Most conventional technologies use a structure in which a heating wire is wound around an insulating substrate such as mica.

Recently, there are also planar heating elements in which a conductive circuit is embedded in a desired shape in a ceramic fired block such as alumina.

Furthermore, a planar heating element has been proposed in which a metal substrate for an enamel is coated with an enamel layer and a planar heating conductor is bonded thereto. For example, Japanese Patent Application Laid-Open No. 60-25176.

In addition, this type of sheet heating element includes polyester I on one or both sides of a sheet metal heating element made of aluminum, copper, nickel, stainless steel, iron, etc., which is formed into a desired circuit shape such as a serpentine or spiral shape. Films with synthetic resin insulating films attached, such as fibers, polyimide films, and polycarbonate films, are widely used.

Problems to be Solved by the Invention However, the conventional technology has the following problems.

In the case of mica heaters, it takes time and effort to wind the heating wire around the board, and if the contact between the mica and the heating wire deteriorates, the heating wire becomes dry and becomes hot, making it easy to break. Furthermore, since the heating wire was not sealed, there was a problem with heat resistance. Furthermore, since the thermal conductivity of mica itself is low, the heater temperature becomes high and there is a problem that it is easily deteriorated.

In addition, in the case of a heater using ceramics, the mechanical strength of the ceramic firing block is low, so the thickness increases and the heat capacity increases, resulting in poor heating speed and high sintering temperature, which causes oxidation and melting of the contact material. There were problems with taking out the electrodes.

Furthermore, in the case of enamel heaters, the manufacturing method is extremely complicated and time-consuming, and from the viewpoint of the electrical insulation properties of the enamel layer, it is difficult to make the enamel layer dense, with less alkali content such as Na, and borosilicate. It is desirable to increase the thickness of the abrasion layer, but on the other hand, if the heat resistance is 1, the heat resistance tends to decrease, and when considering the balance between the two, it is difficult to use it at high temperatures of 300°C or higher. .

In addition, in the case of heaters using films made of silicone resin, polyimide resin, etc., the operating temperature depends on the heat resistance temperature of the insulating film, so for example 25
If the heat is generated above 0°C, the insulating film may be damaged.

The present invention solves these conventional problems by heat-pressing a metal heating element between two sheets.
Can be used sufficiently at surface temperatures of 0 to 500°C,
The purpose is to provide a thin and compact planar heating element.

Another object of the present invention is to provide a planar heating element that has excellent productivity, generates relatively little smoke during firing, and can be manufactured at low cost.

Means for Solving the Problems In order to solve the above problems, the present invention provides a porous heat-resistant base material with a metal heating element between two sheets impregnated with polytitanocarbosilane. It is characterized by being heat-pressed and used.

°Function The above configuration provides an excellent high-temperature surface heater. Metal heating elements that can be used in the present invention include aluminum, copper, nickel, stainless steel, iron, alloys, etc., and foils that can be formed into desired shapes such as meandering and spiral shapes.

Here, as the porous heat-resistant base material in the present invention, materials having excellent heat resistance such as glass, graphite, silica, alumina, silicon carbide, mica, and other inorganic fibers, nonwoven fabrics, tapes, and papers can be used.

It is desirable to use a bulk density of these base materials in the range of 0.2 to o, sy/-. This is because if the bulk density is less than 0.2, heating EE adhesion will be difficult, and if it exceeds 0.5, the impregnating property will be poor.

Polytitanocarbosilane is made by combining polydimethylsilane, which is synthesized by the dechlorination polycondensation reaction of dimethyldichlorosilane, with a semi-inorganic polymer called polyborodiphenylsiloxane, which is obtained by polycondensation of diphenyldichlorosilane and boric acid, and a titanium compound. Obtained by heating and polycondensing.

Polytychnocarponran is an organometallic crosslinked polymer in which a polycarbosilane moiety mainly consisting of a carbosilane skeleton is crosslinked and polymerized with a titanium compound. .

-S i -CH2- Number of functional groups in 1Ti: 1 to 4 " It consists of basic structural units such as.

Since this polytitanocarbosilane is easily dissolved in an organic solvent, it is used in a dissolved state.

In addition, in the present invention, the heat-drying temperature of such a heat-resistant base material impregnated with polytitanocarbosilane is 2.
The temperature is preferably 00 to 300°C, because if polytitanocarbosilane is insufficiently heated or dried excessively, its self-adhesiveness and adhesion to the substrate will deteriorate.

The porous heat-resistant base material impregnated with polytitanocarbosilane was dried by heating at 250°C for 1 hour, and then heated to 800°C. The weight loss rate was 30'%.

On the other hand, a porous #thermal substrate impregnated with polyborosiloxane was heated and dried at 250'C for 1 hour, and then
The weight loss rate when heated at 0°C-1 was 50°.

Further, on one or both sides of this planar heating element, an organosilicon polymer containing a polysiloxane polymer or a polytitanocarbosilane as a main component, a white compound, and a black compound are used alone or in combination with a black compound. It is more preferable to form a dispersed coating because in the former case, the material becomes a far-infrared radiator, and in the latter case, it becomes a pseudo-blackbody and has high infrared radiation ability.

As white compounds, Ti, AI! , St , Zr0
Oxides and composite oxides of one or more elements selected from the group are preferable, and black compounds include Fe, Mn,
Cu.

It is desirable to use an oxide or composite oxide of one or more elements selected from the group of Ni, Cr, and Co.

Note that this coating may contain additives such as heat-resistant fillers.

Example Embodiments of the present invention will be described below based on the accompanying drawings.

The sheet heating element 1 in the embodiment shown in FIG. 1 is made of 5US430
Alumina-based ceramic paper was impregnated with polytitanocarbosilane (xylene 40I solution) on both sides of the metal heating element 2 formed into a desired circuit shape, and heated at 250°C
3 and 3', which had been heated and dried for a period of time, were heated and pressurized at 150° C. for 2 to 3 minutes.

The planar heating element 5 in the embodiment shown in FIG. Through two aluminum plated steel plates 5.5' as materials,
An infrared coating 6.6' having the following composition was provided.

When the electrical insulation properties of the porous heat-resistant base material impregnated with polytitanocarbosilane were measured at room temperature and 500°C using the units shown in Figures 1 and 2, the insulation resistance at room temperature was 2X. 109 (Ω) or more, insulation resistance cuff 5Z2.8
KV, insulation resistance at 500℃ is 2.3X106 (Ω),
The dielectric strength was 2.5 KV.

In addition, 50% of the infrared radiation coating of the unit shown in Figure 2
The emissivity at 0°C was 0.94.

As described above, according to the present invention, the electrical insulation between the metal substrate and the metal heating element is superior to that of the conventional planar heating element of this type, and the electrical insulation between the metal heating element and the polytitanocarbosilane The contact force with the porous heat-resistant base material impregnated with SO is sufficiently high even at 400 to 500°C, so it can be used as a sheet heating element.
Can be used at 0°C. Furthermore, since the heat capacity is small, the temperature rises quickly, and it has the advantage that it is thin and can be designed in various shapes. Since the metal heating element is bonded with a porous heat-resistant base material impregnated with polytitanocarbosilane, there is no dry firing or deterioration due to water vapor, resulting in high reliability.

Further, compared to the case where a borosiloxane polymer is used as the sheet sandwiching the metal heating element, a sheet using polytitanocarbosilane generates less smoke during firing, which is advantageous in terms of the working environment.

It is also characterized by its simple construction method and excellent productivity.

Furthermore, if an infrared high radiant body is arranged, it becomes an effective planar heat source as an infrared radiant heating body.

[Brief explanation of drawings]

1... Planar heating element, 2... Metal heating element element, 3.3'... Porous heat-resistant base material impregnated with polytitanocarbosilane, 4 ...Sheet heating element, 5.5' ...Aluminium-plated steel plate, 6.6
'...Infrared radiation coating. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Fig. 2/-M-Face plate is also heated 2--One piece 4I5 Heat-stopped Heat-resistant winding material 4-1 One-sided tip soldered outside σ,,j'--Aluminum A plating p side 6, 6 '
-m-mida1'-multiple &J'1 coding

Claims (2)

[Claims] (1) A planar heating element in which a metal heating element element is heat-pressed between two sheets of a porous heat-resistant base material impregnated with polytitanocarbosilane. (2) The planar heating element according to claim 1, wherein a metal base material is provided on the surface of the sheet, and an infrared radiation coating is applied to the surface of the metal base material.