KR20110033382A - Face-shaped heater for high temperature use and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A high temperature face upper heating body and a manufacturing method thereof are provided to improve the durability and the heat efficiency of product by molding the insulating paper and the heat source as one body through thermosonic. CONSTITUTION: Upper and lower Muscovitum insulating papers(110, 120) into one body harden in the state where the mica papers of the semi-hardened state in which the inorganic adhesive is spread are laminated to multilayer through thermosonic. It is laminated to multilayer and in upper and lower Muscovitum heat sources(130, 140), the mica papers of the semi-hardened state in which the carbon paint is coated in the surface are composed.

Description

Face-shaped heater for high temperature and manufacturing method thereof

The present invention relates to a high-temperature planar heating element and a method for manufacturing the same by installing electrodes between carbon-coated conductive mica sheets and laminating mica insulating papers on top and bottom thereof, respectively, and thermally pressing them.

In general, the planar heating element by electricity is not only easy to control the temperature, but also sanitary because the air is not polluted, and is widely used for residential heating devices such as apartments or general houses because there is no noise. In addition, these planar heating elements can prevent the melting of snow or freezing of roads and parking lots, such as heating in commercial buildings, industrial heating in workshops, warehouses, and barracks, various industrial heating devices, agricultural facilities in vinyl houses and agricultural product drying systems. In addition to various freeze protection devices that can be used, such as leisure, cold protection, home appliances, anti-fog of mirrors and glass, health supplement, animal husbandry.

As shown in FIG. 1, the conventional planar heating element has a structure in which a conductive heating sheet 2 is positioned between the insulating plates 1, and an electrode 3 is provided on the heating sheet 2.

The heat generating paper 2 is a conductive polymer heat generating paper 2 in which carbon powder is dispersed or applied to paper, polyester film, nonwoven fabric, or the like. This is because the conductive polymer heating paper 2 not only generates heat uniformly on the entire surface of the heating element but also has excellent far-infrared radiation characteristics. Therefore, the conductive polymer heating paper 2 is well suited to not only a contact heating type planar heating element attached to an object to be heated but also a far-infrared radiation planar heating element which can be heated while maintaining a certain distance from the object. The insulating plate 1 is bonded by applying an adhesive on the upper and lower portions of the heat generating paper 2 using an epoxy resin or urethane resin for insulation and waterproofing.

However, such conventional planar heating elements are not suitable as high temperature planar heating elements capable of generating heat up to a high temperature of 300 or more. The conventional planar heating element is because the heat generating paper (2) is a pulp material and the insulating layer is also made of epoxy resin or urethane resin, which is easily broken or broken at high temperature, and thus has poor heat resistance. Therefore, the conventional planar heating element has a limit in the heat generation temperature, and thus requires a lot of maintenance costs.

In order to solve this problem, recently, a mica plate manufactured in a hard or soft sheet form through a thermal pressure by mixing mica formed in a fine powder form and heat-resistant resins such as epoxy resin, alkyd resin, and silicon at a predetermined ratio is obtained. ) To form an adhesive layer by applying an adhesive to the inner surface of the insulating plate (1), and then attached to the upper and lower surface layers of the heat generating paper (2) by heat and pressure to heat up to 500 or more Heating elements have been developed.

The conventional high temperature planar heating element has the following problems.

First, the conventional high-temperature planar heating element replaces the insulating plate 1 with a material having excellent heat resistance, and the heat generating paper 2 inside is still made of paper, a polyester film, or a nonwoven fabric, so that the heat resistance is weak. .

Second, the conventional high-temperature planar heating element has a structure in which the heat generating paper 2 and the insulating plate 1 having different thermal expansion coefficients are bonded through an adhesive, so that the heat generating paper 2 and the insulating plate 1 have different thermal expansions at high temperature. Repeated contraction and this leads to a problem that the durability is weakened and the product life is shortened. In addition, when the heat generating paper (2) and the insulating plate (1) repeats thermal expansion and contraction during high temperature heat generation, the adhesive part is lifted and air enters the excited part, causing a problem that the heat generation temperature drops.

Third, in the conventional high-temperature planar heating element, since the heat-resistant resin in which the insulating plate 1 is mixed with mica is made of an organic adhesive, harmful gases such as benzene and formaldehyde are generated as the organic adhesive is thermally decomposed during the heat generation of the planar heating element at high temperature. In addition, when the organic adhesive is continuously in a high temperature state, a crack occurs in the adhesive layer between the insulating plate 1 and the heat generating paper 2. In addition, the surface resistance is increased due to a decrease in the bonding strength between the carbon and eventually leads to a problem that the heat generation temperature is lowered.

The present invention has been made in order to solve the above problems, do not use a release material, even after long-term use, the adhesion state between the heating paper and the insulating plate is excellent and does not use the organic adhesive generates harmful gases at high heat generation The purpose of the present invention is to provide a planar heating element for high temperature and a method of manufacturing the same, which can maximize the durability of the product and maintain the exothermic temperature at all times.

In order to achieve the above object, the high-temperature planar heating element of the present invention comprises an upper mica insulating paper and a lower mica insulating paper which are cured integrally through heat pressure in a state in which semi-cured mica sheets coated with an inorganic adhesive are laminated in multiple layers; It is made of a mixture of pure carbon powder in the inorganic adhesive or semi-cured mica coated on the surface of the carbon coating made of the carbon fiber and the pure carbon powder in the inorganic adhesive. Upper and lower mica heating paper which is positioned between and hardened integrally with the upper and lower mica insulating paper through thermal pressure; And an electrode disposed between the upper mica heating paper and the lower mica heating paper.

High-temperature planar heating element of the present invention configured as described above has the following effects.

First, since the present invention uses a mica-based heating paper, the heat resistance of the heating paper is very excellent.

Second, since the thermal expansion coefficients are the same because both the insulating paper and the heat generating paper are made of mica, the interlayer adhesion failure caused in the process of repeating thermal deformation in a high temperature environment due to the different materials of the insulating paper and the heating paper as in the prior art. No defects such as

Third, in the present invention, since the insulating paper and the heat generating paper are integrally formed through thermal pressure without forming a separate adhesive layer, defects caused by the failure of the adhesive layer in the process of repeating the thermal deformation in a high temperature environment as in the prior art are prevented. . Therefore, there is an effect that can greatly improve the durability and thermal efficiency of the product.

Fourth, since the present invention uses an inorganic adhesive without using an organic adhesive, it does not generate harmful gases when heated at high temperatures, and does not thermally decompose even when continuously at a high temperature. Therefore, it is possible to maintain a constant constant heating temperature at all times, thereby greatly improving the life of the product.

The features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It must be interpreted to mean meanings and concepts.

2 is a cross-sectional view of a high-temperature planar heating element according to the present invention, Figure 3 is a flow chart for showing a high-temperature planar heating element manufacturing method according to the present invention, the high-temperature planar heating element of the present invention and the manufacturing method through the drawings. Will be described in detail.

High-temperature planar heating element 100 according to the present invention is the upper mica edge softening and lower mica insulating paper (110,120) and inorganic, which is cured integrally through heat pressure in a state in which the semi-cured mica sheets coated with an inorganic adhesive are laminated in multiple layers. Semi-molecular mica sheets coated with a carbon coating made of pure carbon powder mixed with an adhesive or carbon fiber and pure carbon powder mixed with an inorganic adhesive are coated on the surface of the upper and lower mica insulating papers (110,120). And disposed between the upper and lower mica heating papers 130 and 140 and the upper and lower mica heating papers 130 and 140 that are cured integrally with the upper and lower mica insulating papers 110 and 120 through thermal pressure. It consists of an electrode 150.

Mica is a coarse mineral of igneous rock and metamorphic rock. These micas are generally produced as hexagonal crystals and have the property of splitting into very thin and tough plates.

Mica, in particular, withstands high voltages due to its low conductivity and high dielectric strength (white mica 1500-3000, gold mica 1000-1500 volts / mill). In addition, mica is characterized by low power loss (High Q Factor), high resistance (back mica 1015-1016, gold mica 1012-1014 ohm / cm) and storage capacity safety, high dielectric constant (Dimica constant 8-8) It has the property to store electrostatic energy instantaneously because it possesses mica mica 5-6).

The characteristics of mica described above are reasons why mica is used in numerous electrical products such as condensers, transformers, rheostats, fuses, thermoelectric valve bridges, incandescent lamps, and vacuum tube insulation. In addition, more than 90% of the mica is used in electrical appliances or related fields. These mica are incompressible, and because of their chemical inertness, flexibility and transparency and high mechanical strength, they do not react with water or acids (except hydrofluoric acid and concentrated sulfuric acid), alkalis, optical solvents, It is used in windows of stoves and furnaces, retardation plates of helium-neon lasers, gauge glass of high-pressure steam boilers, and the like.

In addition, mica is an ideal insulator with natural structural stability at high temperatures and with high insulation strength. These micas have curvature, elasticity and high tensile strength, but are rather soft and can be cut by hand so that they are processed into various forms and used in various industries.

Such mica can be produced in a very thin thickness, such as paper, by grinding the mica or gold mica in fine powder form and then diluting with water to pass through a paper machine.

The upper mica insulating paper 110 and the lower mica insulating paper 120 constituting the present invention are manufactured by stacking mica papers having a thickness of 0.03 mm to 1.5 mm in the above-described manner, and the upper mica insulating paper 110. ) And the lower mica insulating paper 120 is about 0.2mm to about 10mm respectively. As such, when the upper mica insulating paper 110 and the lower mica insulating paper 120 are composed of multilayered mica papers, the amount of lamination can be freely made so that the mica insulating paper having an optimal thickness can satisfy the strength, moisture resistance, thermal conductivity, and workability. You can easily adjust the thickness of mica insulation paper as you adjust it.

Mica papers, on the other hand, are applied with an inorganic adhesive on the surface before they are laminated. The inorganic adhesive 20 to 40% by weight liquid sodium silicate, 20 to 45% by weight liquid potassium sodium, 9 to 30% by weight liquid lithium soda, 1 to 5% by weight liquid silicazol, dilution water 5 to 50% by weight It may be made of a composition.

This is because when the liquid sodium silicate is less than 20% by weight, the mechanical (bending) strength of the mica paper is lowered, and when it exceeds 40% by weight, the moisture resistance and the heat resistance deteriorate. In addition, when the liquid potassium soda is less than 20% by weight, the heat resistance of the mica paper is worsened, and if it exceeds 45% by weight, the strength is lowered. In addition, when the liquid lithium soda is less than 9% by weight, the moisture resistance of the mica paper is deteriorated. In addition, when the liquid silica sol is less than 1% by weight, the heat resistance and adhesiveness of the mica paper is worsened, and when the content exceeds 5% by weight, the problem of strength is generated.

When lamination of the mica papers in the state in which the inorganic adhesive is applied as described above to the appropriate thickness is completed, by heating to a suitable temperature and dried in a prepreg state to complete the manufacture of the upper, lower mica insulating paper (110, 120). More specifically, the laminated mica sheets are semi-cured after drying for 10 to 30 minutes in a 50 to 170 heating and drying furnace, and the laminated mica sheets are integrally bonded while the inorganic adhesive applied is melted during the semi-curing process.

Meanwhile, the upper and lower mica heating papers 130 and 140 are positioned between the upper and lower mica insulating papers 110 and 120. The upper and lower mica heating papers 130 and 140 are manufactured by stacking mica papers having a thickness of 0.03 mm to 1.5 mm in the same manner as the upper and lower mica insulating papers 110 and 120. The thickness of the upper mica heating paper 130 and the lower mica heating paper 140 is preferably 1 mm to 5 mm in consideration of ease of handling, strength, thermal conductivity, processability, and the like.

And, before the mica sheets are laminated, a carbon paint mixed with an inorganic adhesive and pure carbon powder is coated on the surface. The carbon coating may be a mixture of an inorganic adhesive, carbon fiber, and pure carbon powder.

 In the case of the carbon coating mixed with the inorganic adhesive and the pure carbon powder, the carbon coating is composed of 70 to 90% by weight of the inorganic adhesive and 10 to 30% by weight of the carbon powder. At this time, the inorganic adhesive is the same as the inorganic adhesive used in the upper and lower mica insulating paper (110,120), it is preferable to use a carbon powder consisting of fine grains of 15 to 60nm in diameter.

On the other hand, in the case of the carbon powder mixed with the inorganic adhesive, carbon fiber and pure carbon powder, the carbon coating is composed of 70 to 90% by weight of the inorganic adhesive, 5 to 20% by weight of the carbon powder and 5 to 10% by weight of the carbon fiber Is done. At this time, the inorganic adhesive is the same as the inorganic adhesive used in the upper and lower mica insulating paper (110,120), and the carbon powder made of fine grains of 15 to 60nm diameter and carbon fiber having a length of 0.5 to 3mm. It is suitable.

In addition, the amount of the carbon coating applied to the surface of the mica paper is 10 to 50 parts by weight relative to 100 parts by weight of mica paper. This is because when the carbon coating is applied at less than 10 parts by weight, the carbon content is low and the density of carbon is lowered. Therefore, the resistance is increased and the exothermic temperature is greatly reduced. When the carbon coating is applied at more than 50 parts by weight, the coating thickness becomes thicker. This is because cracking is likely to occur in the coating layer. When the carbon coating layer is cracked, the adhesion between the layers of mica is reduced, the durability is not constant, and the heat generation resistance is increased, and the heat generation temperature is greatly decreased.

When the application of the carbon coating to the mica is completed, the step of drying for 10 to 30 minutes in a 50 to 170 heat drying furnace to dry the mica coated with the carbon coating in a semi-cured state.

When the upper mica heating paper 130 and the lower mica heating paper 140 are prepared through the above process, the electrode 150 is disposed between the upper mica heating paper 130 and the lower mica heating paper 140.

In addition, the previously prepared upper mica insulating paper 110 and the lower mica insulating paper 120 are positioned below the upper and lower mica heating paper 140 of the upper mica heating paper 130, respectively. In this case, the stacking is performed in the order of the lower mica insulating paper 120-the lower mica heating paper 140-the electrode 150-the upper mica heating paper 130-the upper mica insulating paper 110 in a semi-cured state. A preplanar heating element is produced.

The preplanar heating element thus produced is cut to a suitable size and subjected to a thermocompression process for 50 to 100 minutes at a pressure of 5 to 50 kg / at a temperature of 160 to 250. In the thermocompression process, the mica insulating paper and the mica heating paper in the semi-cured state are melted together while the coated inorganic adhesive is melted, and is completely cured at a high temperature above the curing point, thereby integrating the planar heating element 100 of the present invention. Is completed.

On the other hand, the high-temperature planar heating element 100 of the present invention is the step of cooling the heat-treated preplanar heating element to room temperature, and then reheating the cooled preplanar heating element to 200 to 700 to re-cool the heat treated preplanar heating element at room temperature You can also go further. In this case, since the fine moisture remaining in the planar heating element is completely removed in the process of reheating during the heat pressure process, the finally completed planar heating element can significantly improve the quality of the product while preventing moisture absorption.

As described above, preferred embodiments of the present invention are described above with reference to the drawings, but the present invention is not limited to the above-described embodiments, and those skilled in the art may modify the present invention without departing from the spirit of the present invention. Possible, such modifications will fall within the scope of the invention.

1 is a cross-sectional view of a conventional planar heating element.

Figure 2 is a cross-sectional view of the planar heating element for high temperature according to the present invention.

Figure 3 is a flow chart for showing a planar heating element manufacturing method for high temperature according to the present invention.

<Explanation of symbols for main parts of the drawings>

100 ... Plane heating element 110 ... Upper mica insulating paper

120 .... Lower Mica Insulation Paper 130 ... Lower Mica Heating Paper

140.Lower mica heating paper 150 ... electrode

Claims (10)

Upper mica insulating paper and lower mica insulating paper which are cured integrally by thermal pressure in a state where semi-cured mica sheets coated with an inorganic adhesive are laminated in multiple layers; It is made of a mixture of pure carbon powder in the inorganic adhesive or semi-cured mica coated on the surface of the carbon coating made of the carbon fiber and the pure carbon powder in the inorganic adhesive. Upper and lower mica heating paper which is positioned between and hardened integrally with the upper and lower mica insulating paper through thermal pressure; The planar heating element for high temperature, characterized in that it comprises an electrode disposed between the upper mica heating paper and the lower mica heating paper. Preparing an upper mica insulating paper and a lower mica insulating paper by drying the mica coated with the inorganic adhesive in a semi-cured state and then laminating them in a multilayer; Mica coated with pure carbon powder made of inorganic adhesive or carbon fiber and pure carbon powder mixed with inorganic adhesive is dried in a semi-cured state and then laminated in multiple layers to heat the upper mica heat paper and the lower mica heat. Preparing paper; Disposing an electrode between the upper mica heating paper and the lower mica heating paper; Preparing a preliminary surface heating element by laminating in order from the lower mica insulating paper, the lower mica heating paper, the electrode, the upper mica heating paper, and the upper mica insulating paper dried in a semi-cured state; And Method for producing a high-temperature planar heating element, characterized in that it comprises a step of curing by heating the preliminary planar heating element. 3. The method of claim 2, Preparing an upper mica heating paper and a lower mica heating paper by drying the mica coated with a carbon coating made of a mixture of pure carbon powder or pure carbon powder mixed with carbon fibers in a semi-cured state and then laminating them in a multilayer manner. in, The carbon coating is a high-temperature planar heating element manufacturing method comprising the composition of the inorganic adhesive 70 to 90% by weight and carbon powder 10 to 30% by weight. 3. The method of claim 2, Preparing an upper mica heating paper and a lower mica heating paper by drying the mica coated with a carbon coating made of a mixture of pure carbon powder or pure carbon powder mixed with carbon fibers in a semi-cured state and then laminating them in a multilayer manner. in, The carbon coating is a high-temperature planar heating element manufacturing method comprising the composition of the inorganic adhesive 70 to 90% by weight, carbon powder 5 to 20% by weight and carbon fiber 5 to 10% by weight. 3. The method of claim 2, Preparing an upper mica heating paper and a lower mica heating paper by drying the mica coated with a carbon coating made of a mixture of pure carbon powder or pure carbon powder mixed with carbon fibers in a semi-cured state and then laminating them in a multilayer manner. in, The inorganic adhesive 20 to 40% by weight liquid sodium silicate, 20 to 45% by weight liquid potassium sodium, 9 to 30% by weight liquid lithium soda, 1 to 5% by weight liquid silicazol, dilution water 5 to 50% by weight Method for producing a planar heating element for high temperature, characterized in that consisting of. The method according to any one of claims 2 to 5, Preparing an upper mica heating paper and a lower mica heating paper by drying the mica coated with a carbon coating made of a mixture of pure carbon powder or pure carbon powder mixed with carbon fibers in a semi-cured state and then laminating them in a multilayer manner. in, The thickness of the mica paper is 0.03 to 1.5mm, The amount of the carbon coating applied to the mica paper is a planar heating element for high temperature, characterized in that 10 to 50 parts by weight based on 100 parts by weight of mica paper. 3. The method of claim 2, Preparing an upper mica heating paper and a lower mica heating paper by drying the mica coated with a carbon coating made of a mixture of pure carbon powder or pure carbon powder mixed with carbon fibers in a semi-cured state and then laminating them in a multilayer manner. in, The mica paper is a method for producing a high-temperature planar heating element, characterized in that dried in a semi-cured state through a step of drying for 10 to 30 minutes in a heat drying furnace of 50 to 170. 3. The method of claim 2, The hot pressure in the step of curing the preliminary planar heating element is a high temperature planar heating element manufacturing method characterized in that to perform for 50 to 100 minutes at a pressure of 5 to 50 at a temperature of 160 to 250. The method according to claim 2 or 8, After curing the preplanar heating element by hot pressing The step of cooling the heat-cured preplanar heating element at room temperature, the step of reheating the cooled preplanar heating element, and the step of re-cooling the heat-treated preplanar heating element at room temperature Way. The method of claim 9, Method for producing a high-temperature planar heating element, characterized in that the heating temperature in the step of reheating the cooled preplanar heating element is 200 to 700.

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