WO2019039718A1

WO2019039718A1 - Woven flexible planar heating element comprising protective film, and method for producing same

Info

Publication number: WO2019039718A1
Application number: PCT/KR2018/007092
Authority: WO
Inventors: 이동윤; 차승일
Original assignee: 한국전기연구원
Priority date: 2017-08-23
Filing date: 2018-06-22
Publication date: 2019-02-28
Also published as: CN111034353A; KR102434600B1; KR20190021680A

Abstract

The present invention relates to a woven flexible planar heating element comprising a protective film, and a method for producing the heating element, and the technical gist of the present invention is to include: a heating layer formed by weaving a metallic heating fiber; and a protective film, made of a polymeric material, which surrounds the surface of the heating layer so as to protect the heating layer from the external environment, and is impregnated in the spaces between woven threads of the metallic heating fiber such that no void is present therein. Accordingly, a woven flexible planar heating element comprising a protective film can be obtained which has a protective film employing molding and thus has excellent flexibility and is free from peeling during use, enables a high production speed, and has stable quality. Also, heat emitted from the heating layer is reflected and thus heat direction control is possible, which enables a high thermal efficiency and a reduction in heating time.

Description

WOVEN FABRIC PLASTICS HEATING ELEMENT AND PROCESS FOR PRODUCING THE SAME

The present invention relates to a woven soft-surface heating element including a protective film and a method for manufacturing the same, and more particularly, to a protective film formed by forming a protective film using molding to provide a protective film having excellent flexibility, And a method of manufacturing the same.

Generally, a heating element that converts energy from electricity or gas into heat energy is divided into a linear heating element made of metal or ceramic wire, a bulk heating element such as graphite, and a plane heating element coated with a heating element on a flat electrode. The double-sided heating element has a metal, ceramic or carbon-based heating layer coated on a planar metal electrode, and the upper and lower portions of the heating layer are sealed with an insulator.

In recent years, there has been a need to manufacture a flexible surface heating element having the shape of a curved surface rather than a flat surface, or capable of flexing flexibly during use. A conventional flexible surface heating element is manufactured by coating a material such as carbon on a flexible substrate or by arranging a linear heating element such as nichrome on a flexible material such as a plastic film or cloth and fixing the same. However, such a planar heating element has a problem of durability, a problem that the heating is not uniformly generated over the whole area, and a problem of the linear heating element that the entire heating element becomes inoperable if the line is broken. For example, a carbon-based electrode, which is expected to be a planar heating element, is oxidized at a high temperature and is brittle, easily cracking due to impact, and the planar heating element can not be used for a long time due to such a problem. In addition, when the far-infrared ceramic heat-generating body is coated on the metal substrate, there is a disadvantage that it can not be used when the bending of the surface heat-generating body is large due to the warp limit of the ceramic heat-generating body.

In order to overcome this problem, there is known a technique for manufacturing a surface heating element by weaving a conductive material into a line. There is known a method of weaving an area heating element by using a weaving yarn made by twisting together ordinary fibers and metal fibers, such as 'Korean Patent Application No. 10-2008-0090068', a surface heating element and its physical structure and manufacturing method . In addition, there is known a surface heating element technique in which conductivity is imparted by coating conductive carbon on the surface of a non-conductive polymer seal, such as "Korean Utility Model Registration Utility Model No. 20-2005-0011304".

As described above, the metal-fiber surface heating element is produced by thermally bonding a layer made of a polymer-based insulating material to both surfaces of the heating electrode after woven thereon, or by attaching insulating ceramic fibers in layers. However, there is a problem in that the efficiency is poor due to the thick thickness of the polymer layer bonded to the heating element electrode during the production of the flat type surface heating element in this manner, and there is a material problem that delamination occurs due to mechanical repeated stress during use. Also, the production process is complicated in terms of the manufacturing process, the production speed is low, and expensive manufacturing equipments such as the thermocompression equipment are required. Therefore, it is difficult to make the heating elements of various shapes because the mold must be used.

Accordingly, it is an object of the present invention to provide a woven flexible heat generating element comprising a protective film formed by molding and having excellent flexibility, no peeling during use, high production speed and stable quality, and a method of manufacturing the same.

Also, it is an object of the present invention to provide a woven flexible surface heating element including a protective film which can be heated in a heating direction and can be controlled in a thermal direction, thereby achieving a high thermal efficiency and shortening a heating time.

The above-mentioned object is achieved by a heat-shrinkable laminate comprising: a heat generating layer formed by weaving metal heating fibers; And a protection film of a polymer material which is impregnated while the metal heating fibers are woven so as to surround the surface of the heating layer so as to protect the heating layer from the external environment so that pores do not exist. Is achieved by a flexible planar heating element.

Here, the protective film may be formed by molding the heat generating layer by dipping the heat generating layer in a roll-to-roll manner into the liquid polymer, or the protective film may be formed by any one of a spraying method, a screen printing method and a doctor blade method .

And a reflective layer formed by woven ceramic fibers laminated on one surface of the heating layer and reflecting heat generated from one surface so that heat generated from the heating layer is emitted to the other surface, The ceramic fibers are preferably impregnated during the weaving process so as to surround the surface of the heating layer and the reflective layer.

The heating layer is formed by weaving the metal heating fibers with warp and weft, and the reflecting layer is formed by weaving the ceramic fibers with warp and weft, and the heating layer and the reflecting layer are preferably bonded or stitched together It is preferable that the metal heating fibers are woven in warp and weft, and the ceramic fiber is woven together with warp and weft, thereby integrally weaving the heating layer and the reflection layer.

It is preferable that the heat generating layer has an arrangement area of the metal heating fibers larger than that of the ceramic fibers as compared with the reflective layer and the arrangement area of the ceramic fibers in the reflective layer is wider than the metal heating fibers as compared with the heating layer.

The ceramic fiber is preferably selected from the group consisting of glass fiber, heat-resistant polymer fiber, titanium oxide fiber, aluminum oxide fiber, zirconium oxide fiber, silicon carbide fiber, potassium titanate fiber, barzat fiber and a mixture thereof.

It is preferable that a heat insulating layer made of a polymer and ceramic particles is laminated on the protective film and a radiation layer made of a polymer and a carbon material is laminated on a surface facing the heat insulating layer laminated on the protective film.

The material of the heat generating fiber is selected from the group consisting of platinum (Pt), iron (Fe), nickel (Ni), aluminum (Al), copper (Cu), titanium (Ti), molybdenum (Mo) (Ag), palladium (Pd), ruthenium (Ru), magnesium (Mg), chromium (Cr), zinc (Zn), tungsten (W), cobalt , And the polymer material is preferably selected from the group consisting of an epoxy resin, an acrylic resin, a polyamide resin, a polyimide resin, and a mixture thereof.

The above-mentioned object is also achieved by a method of manufacturing a metal foil, comprising: weaving a metal heating fiber to form a heat generating layer; Applying a polymer so as to surround the surface of the heating layer and impregnating the polymer while the metal heating fibers are woven to prevent pores from forming a protective layer, And is also achieved by a method for producing an area heating element.

Here, the protective film may be formed by molding the heat generating layer by a roll-to-roll method in a liquid polymer, or the protective film may be formed by any one of a spraying method, a screen printing method and a doctor blade method .

According to the structure of the present invention described above, a protective film using molding is formed to obtain a woven flexible heat generating element including a protective film having excellent flexibility, no peeling during use, high production speed and stable quality.

In addition, heat emitted from the heat generating layer is reflected and the thermal direction can be controlled, thereby achieving high heat efficiency and shortening the heating time.

1 is a cross-sectional view of a woven soft-surface heating element according to an embodiment of the present invention,

2 is a cross-sectional view illustrating a protective film forming process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1A is a woven soft-surface heating element 10 according to the first embodiment, and includes a heating layer 11 and a protective film 13. Fig. The heat generating layer (11) is formed by woven metal heating fibers, which are made of metal that generates heat, in a thin line. As the weaving method, general weaving methods such as resigning, twilling and water-repellent can be used. Available. The material of the heat generating fiber is selected from platinum (Pt), iron (Fe), nickel (Ni), aluminum (Al), copper (Cu), titanium (Ti), molybdenum (Mo) ) Selected from the group consisting of palladium (Pd), ruthenium (Ru), magnesium (Mg), chromium (Cr), zinc (Zn), tungsten (W), cobalt It is preferable that the heat-generating fibers are made of different metals or alloy materials and are woven. In particular, stainless steel or nichrome can be used most preferably for metal heating fibers made of alloy, and stainless steel and nichrome can be prepared singly or in combination.

In the case of stainless steel fibers, SUS304, SUS304L, SUS316, SUS316L and the like can be used, and they are excellent materials in the present invention because of their excellent flexibility, strength, straightness and heat generation. Nichrome fiber has high heat-generating efficiency and is less flexible than stainless steel fibers or superior materials that are easy to weave. In the case of fibers made of single or alloy, the heat generation efficiency is lower than that of stainless steel fiber or nichrome fiber, but it can be easily used when special equipment such as semiconductor equipment or characteristics inherent to metal are required.

When the diameter of the metal heating fibers is less than 10 mu m, the metal heating fibers are very close to each other and the protective layer 13 is difficult to be molded between the intervals, If the thickness exceeds 200 m, the thick heating layer 11 may be formed and the flexibility may be deteriorated.

The protective film 13 is formed of a polymer material and has a structure in which the heating layer 11 is surrounded to protect the heating layer 11 from external environment and to be insulated. At this time, the protective film 13 is formed of a polymer material that surrounds the surface of the heat generating layer 11 to protect the heat generating layer 11 from the external environment and is impregnated while the metal heating fibers are woven to prevent pores. That is, the protective film 13 is formed so as to surround the outer surface of the heat generating layer 11 in order to prevent the heat generating layer 11 from being leaked or short-circuited due to contact with the outside, .

When pores are present between the heating layer 11 and the protective film 13, if the surface heating body 10 is continuously bent or washed, cracks are generated in the pores due to external stimulation, (13) may be separated from each other. In particular, when the insulating layer is laminated on the surface of the heat generating layer, and the heat insulating layer is pressed through the heat treatment as in the prior art, pores are always present between the heat generating layer and the insulating layer, There may be a problem that the pores are cracked. However, in the case of the present invention, the polymer is impregnated between the metal heating fibers constituting the heating layer 11 so that pores do not exist, and the polymer impregnated on the surface of the heating layer 11 and the polymer The protective film 13 can be formed.

The method for producing the planar heating element 10 includes the steps of forming the heating layer 11 by weaving the metal heating fibers; Applying a polymer so as to surround the surface of the heat generating layer 11 and impregnating the polymer while the metal heating fibers are woven so that pores do not exist to form the protective layer 13. [

The protective layer 13 may be formed by molding the liquid polymer 1 as shown in Fig. 2 and immersing the exothermic layer 11 in the liquid polymer 1 . When the protective film 13 is formed through the molding, the liquid polymer 1 is disposed between the woven heat generating layers 11 and cured, so that the heat generating layers 11 are filled uniformly and tightly, 13) can be formed. At this time, the exothermic layer 11 is fed into the liquid polymer 1 in a roll-to-roll manner.

Generally, as a method of coating a polymer, a thermoplastic insulating polymer film is attached to the upper and lower portions of the heat generating layer, and the polymer protective film is laminated on the heat generating layer by thermocompression bonding. When the protective film is formed in this manner, the polymer is not properly filled between the heating layers, and separation may occur during use depending on the state of the polymer film, resulting in product failure. In contrast, when the protective layer 13 is manufactured through the molding method of the present invention, since the heating layer 11 is stably inserted into the polymer, it is mechanically very stable, . In addition, since the roll-to-roll method is used in the present invention, it is easy to mass-produce, and it is easy to attach using chemical bonding or mechanical bar method, so it is easy to produce products for clothes, outdoor, heating and the like. Also, the spraying method, the doctor blade method, or the screen printing method, which is a method of coating a polymer, does not form an excellent protective film as compared with the molding method of the present invention, but can be used as a process.

Different materials can be used for the polymer material forming the protective film 13 according to the flexibility, usable temperature, and flame retardancy standard. For example, when the woven flexible non-heat generating body 10 is used at a temperature of 150 ° C or less, an epoxy or acrylic resin is preferable. When the resin is used at a temperature of 250 ° C or less, Based resin is preferable. In addition, a polyimide resin is suitable when the woven flexible heat generating element 10 is used at a temperature of 400 ° C or less and high flexibility. All of these resins are coated on the heat generating layer 11 by using a thermosetting resin or an ultraviolet curable resin It should be prepared in the form of high viscosity liquid phase and solid phase after curing. When the heating element 11 of the present invention is applied to a place where flame resistance is required, it is preferable that the heating element 11 is made to have a thermoplasticity of 10 cm, generally 1 to 30 cm, on the basis of a serial in automobiles.

The woven flexible non-heating body 20 according to the second embodiment includes a heating layer 21, a protective film 23 and a reflective layer 25 as shown in Fig. 1B. Here, the heat generating layer 21 and the protective film 23 are formed in the same shape and material as those of the heat generating layer 11 and the protective film 13 according to the first embodiment.

The reflective layer 25 is laminated on one surface of the heat generating layer 21 and reflects heat generated from one surface so that heat generated from the heat generating layer 21 is emitted to the other surface. As shown in FIG. This reflective layer 25 is formed by weaving ceramic fibers. In detail, the protective film 23 exists so as to surround the surfaces of the heat generating layer 21 and the reflective layer 25 while being impregnated with the ceramic fibers so as not to have pores. That is, the protective layer 23 is impregnated so that there is no pore between the reflective layer 25 like the protective layer 23 formed on the heat generating layer 21 as in the first embodiment, (23) are not separated from each other.

Here, the ceramic fiber is a thin line-shaped ceramic material that reflects heat without absorbing heat. Such a ceramic fiber is woven using a weaving method such as resign, twine, and water like the metal heating fiber. The heat-reflecting ceramic fiber material is selected from the group consisting of glass fiber, heat-resistant polymer fiber, titanium oxide fiber, aluminum oxide fiber, zirconium oxide fiber, silicon carbide fiber, potassium titanate fiber, But is not limited thereto. Basalt, which is produced by spinning basalt, is an excellent insulating material and is a material suitable for the present invention.

The structure of the heat generating layer 21 and the reflective layer 25 of the present invention may be formed as follows. First, the heating layer 21 is formed by weaving the metal heating fibers in warp and weft, and the reflecting layer 25 is also formed by weaving ceramic fibers in warp and weft. The heat generating layer 21 and the reflective layer 25 may be adhered using an adhesive or may be bonded by sewing to form the heat generating body 20. [ When the heating element 20 is formed with such a structure, the metal heating fibers and the ceramic fibers are clearly separated from each other so that the heat generated from the metal heating fibers can easily be discharged to the other surface of the heating layer 21. [

In addition, the woven flexible heat-generating body 20, which can be formed in different shapes, is obtained by weaving the metal heating fibers in warp and weft, weaving the ceramic fibers in the warp and weft together with the metal heating fibers to form the heating layer 21 and the reflection layer 25, Is integrally woven. At this time, the area of the woven heat generating layer 21 is larger than that of the reflection layer 25, and the area of the reflection layer 25 is larger than that of the heat generating layer 21, do. Although the heat generating layer 21 includes a part of the ceramic fibers, the heat generating layer 21 has a large area for arranging the heat generating fibers to discharge heat. On the other hand, the reflecting layer 25 includes a part of the heat generating fibers, And serves to reflect the heat emitted from the heat generating layer 21 to the other surface of the heat generating layer 21. [ Here, the heat generating layer (21) has the arrangement area of the metal heating fibers within the range of 70 to 100%, and the reflection layer (25) forms the heating element (20) so that the arrangement area of the ceramic fibers is within the range of 70 to 100% . This is because the arrangement area is less than 70%, and it is difficult to control the direction of heat emitted from the metal heating fiber through the ceramic fiber.

The woven flexible surface heating element 30 according to the third embodiment includes a heating layer 31, a protective film 33, and a heat insulating layer 35. Since the heating layer 31 and the protecting layer 33 are formed of the same shape and material as those of the heating layer 11 and the protecting layer 13 according to the first embodiment, (25) are not separately included.

The insulating layer 35 is formed on the outside of the protective film 33, not on the inside thereof, but on a material made of polymer and ceramic particles. The heat insulating layer 35 allows heat to be emitted to the opposite side without releasing the heat toward the heat insulating layer 35 like the reflective layer 25. [ After the curing of the protective film 33 is completed, the insulating layer 35 is laminated on the lower side by a painting method, a spraying method, a dipping method, a doctor blade method, or a screen printing method. The heat insulating layer 35 having a high heat insulating characteristic is a composite material of a specially produced high heat insulating ceramic and polymer, and has a low thermal conductivity of 0.05 W / mK or less. Since a low thermal conductivity of 0.05 W / mK or less can not be realized in a general single-material polymer, and a special filler is filled in a polymer such as acrylic resin, for example, A heat insulating layer is formed by using a heat insulating material made of a ceramic ball containing a silica ball or a titania ball as a filler.

The woven flexible surface heating element 40 according to the fourth embodiment includes a heating layer 41, a protective film 43, a reflective layer 45, a heat insulating layer 47, and a radiating layer 49. The heating layer 41, the reflective layer 43, the protective film 45 and the heat insulating layer 47 are formed on the heat generating layers 21 and 31, the

protective films

23 and 33, 25 and the heat insulating layer 35, the detailed description thereof will be omitted.

The radiation layer 49 is laminated on the surface facing the heat insulating layer 47 stacked on the protective film 43 and is made of a mixture of a polymer and a carbon material. The radiation layer 49 having a high infrared ray emissivity is formed in consideration of the fact that heat generated in the heating element 40 is dissipated not only by conduction or convection but also by infrared radiation. As a high emissivity material, graphite, nano-carbon, carbon nanotubes or graphene, which are carbon materials, are mixed with the polymer to form a high emissivity material.

In the case of a conventional planar heating element, if it is made of a metal material, electricity may be leaked or short-circuited due to contact with the outside, and mechanical abrasion or breakage may occur. In order to prevent this, a polymer-based insulating material layer is thermally bonded to the both surfaces of the heating electrode after the heating electrode is woven, or the insulating ceramic fiber is laminated to form a layer. However, there is a problem in that the efficiency is poor due to the thick thickness of the polymer layer bonded to the heating element electrode during the production of the flat type surface heating element in this manner, and there is a material problem that delamination occurs due to mechanical repeated stress during use. Also, the production process is complicated in terms of the manufacturing process, the production speed is low, and expensive manufacturing equipments such as the thermocompression equipment are required. Therefore, it is difficult to make the heating elements of various shapes because the mold must be used.

In contrast to this, in the present invention, since the heating layers 11, 21, 31 and 41 are immersed in the liquid polymer 1 to form the

protective films

13, 23, 33 and 43 through molding, The

protective films

13, 23, 33, and 43 can be formed without being separated by the external impact due to uniform and tight filling between the

protective films

13, 23, 33, and 43. Heat generated from the heat generating layers 11, 21, 31 and 41 through the formation of the

heat insulating layers

35 and 47 and the reflecting

layers

25 and 45 is reflected by the

heat insulating layers

35 and 47 and the reflecting

layers

25 and 45 And the heat radiation performance through infrared radiation can be increased through the radiation layers 25 and 45. Thus, it is possible to obtain a high thermal efficiency and shorten the heating time. In addition, the woven

soft surface heaters

10, 20, 30, and 40 of the present invention are formed by weaving the metal heating fibers and the ceramic fibers to form the heat generating layers 11, 21, 31, and 41 and the reflecting

layers

25 and 45 Therefore, it has high flexibility, excellent impact resistance, mechanical durability and electrical properties.

Claims

In the woven flexible heat generating element including the protective film,

A heating layer formed by woven metal heating fibers;

And a protection film of a polymer material which is impregnated while the metal heating fibers are woven so as to surround the surface of the heating layer so as to protect the heating layer from the external environment so that pores do not exist. Flexible flat heating element.
The method according to claim 1,

Wherein the protective film is formed by molding the heat generating layer by immersing the heat generating layer in a roll-to-roll manner in the liquid polymer.
The method according to claim 1,

Wherein the protective film is formed by any one of a spraying method, a screen printing method, and a doctor blade method.
The method according to claim 1,

And a reflective layer formed by woven ceramic fibers that are laminated on one surface of the heating layer and reflect heat generated from one surface so that heat generated from the heating layer is emitted to the other surface,

Wherein the protective film is present so as to surround the surfaces of the heating layer and the reflective layer while being impregnated while the ceramic fibers are woven so that pores do not exist.
5. The method of claim 4,

Wherein the heat generating layer is formed by weaving the metal heating fibers in warp and weft,

Wherein the reflective layer is formed by weaving the ceramic fibers in warp and weft,

Wherein the heat generating layer and the reflective layer are bonded by stitching.
5. The method of claim 4,

Wherein the metal heating fibers are woven in warp and weft, and the ceramic fibers are woven together with warp and weft to weave the heating layer and the reflecting layer integrally.
5. The method of claim 4,

Wherein the heat generating layer has an arrangement area of the metal heating fibers larger than that of the ceramic fibers as compared with the reflective layer and an arrangement area of the ceramic fibers in the reflective layer is wider than the metal heating fibers as compared with the heating layer. Including woven flexible surface heating elements.
5. The method of claim 4,

Wherein the ceramic fiber is selected from the group consisting of glass fiber, heat-resistant polymer fiber, titanium oxide fiber, aluminum oxide fiber, zirconium oxide fiber, silicon carbide fiber, potassium titanate fiber, And a woven flexible non-woven fabric.
The method according to claim 1,

Wherein the protective film is laminated with a heat insulating layer comprising a polymer and ceramic particles.
10. The method of claim 9,

And a radiation layer made of a polymer and a carbon material is laminated on a surface facing the heat insulating layer laminated on the protective film.
The method according to claim 1,

The material of the heat generating fiber is selected from the group consisting of platinum (Pt), iron (Fe), nickel (Ni), aluminum (Al), copper (Cu), titanium (Ti), molybdenum (Mo) (Ag), palladium (Pd), ruthenium (Ru), magnesium (Mg), chromium (Cr), zinc (Zn), tungsten (W), cobalt Wherein the protective film is made of a thermoplastic resin.
The method according to claim 1,

Wherein the polymer material is selected from the group consisting of an epoxy resin, an acrylic resin, a polyamide resin, a polyimide resin, and a mixture thereof.
A method for manufacturing a woven flexible flat surface heating element including a protective film,

Forming a heat generating layer by weaving metal heating fibers;

Applying a polymer so as to surround the surface of the heating layer and impregnating the polymer while the metal heating fibers are woven to form a protective layer so that pores do not exist; A method of manufacturing a heating element.
14. The method of claim 13,

Wherein the protective film is formed by molding the heat generating layer by immersing the heat generating layer in a roll-to-roll system in a liquid polymer.
14. The method of claim 13,

Wherein the protective film is formed by any one of spraying, screen printing, and doctor blade methods.