Patent Application
20140332522
The present invention relates to a cloth-like heater that can warm selectively a plurality of sites.
As a relating technology, as exemplified in
When a plurality of warming sites is provided in which an electroconductive fiber is incorporated into the relating cloth-like heater and it is attempted to apply selectively a voltage to each of the warming sites to warm them in order to achieve an intended temperature distribution, it is necessary to incorporate an electroconductive fiber into the cloth as a conducting part and to electrically connect each of the warming sites and a device for applying a voltage. When the conducting part is made thin in order to broaden the area of the warming site and narrow the area of the conducting part, an electric resistance of the conducting part becomes high and the conducting part itself tends to generate heat. Therefore, sites other than the selected warming site are warmed and it is difficult to set the cloth-like heater to have an intended temperature distribution. Furthermore, if the conducting part is made thick, the area of warming sites in the cloth-like heater becomes small and warming capacity of the cloth-like heater as a whole lowers.
According to the present invention, it is possible to provide a cloth-like heater capable of warming only a selected warming site and achieving an intended temperature distribution, without lowering the warming capacity.
In the cloth-like heater of the present invention, the predominant characteristic is that, a voltage is selectively applied to a linking string of a third fiber layer that electrically connects a first conducting part provided in a first fiber layer and a second conducting part provided in a second fiber layer, and the linking string generates heat.
According to the cloth-like heater of the present invention, when a voltage is applied between a selected first conducting part provided in the first fiber layer and the second conducting part provided in the second fiber layer, since power is supplied from the first conducting part to the linking string constituting the third fiber layer that electrically connects the first conducting part and the second conducting part to generate heat, the warming site of the third fiber layer is warmed. On the other hand, in the first conducting part and the second conducting part that have sufficient width, heat generation is suppressed and, therefore, warming in sites other than the selected warming site is suppressed and it becomes possible to control the warming so that the cloth-like heater has an intended temperature distribution.
a) is another form 1 of a linking string, and
a) is an enlarged view of an electroconductive polymer fiber made of a homogeneous material,
Hereinafter, embodiments will be described in detail with the drawings, by using, as an example, the case where the cloth-like heater of the present invention is used as a seat heater for a car seat.
A cloth-like heater 1 of the present embodiment is, as illustrated in
The upper layer conducting part 4 includes a plurality of upper layer conducting parts 4a, 4b, 4c—having a width of 10 mm and a length of 200 mm formed of a silver-coated fiber (manufactured by Shaoxing Yujia Textile Product Co., Ltd.), and, between the adjacent upper layer conducting parts 4, an upper layer non-conducting part 5 having a width of 2 mm and a length of 200 mm formed of a fiber including a polyester fiber (Gunze Polina, manufactured by Central fiber materials Ltd.) being a non-conductive resin is provided. The lower layer 3 includes a lower layer conducting part 6a in which the silver-coated fiber (manufactured by Shaoxing Yujia Textile Product Co., Ltd.) is braided in the whole surface.
As illustrated in
Using a circular knitting machine manufactured by Precision Fukuhara Works, Ltd., gauge, number of feeds etc. were adjusted so that the thickness of the intermediate heat generation layer between the upper and lower layers became 10 mm and the total area of the cross-section of the electroconductive polymer fiber per unit area of the plane of the intermediate heat generation layer 8 horizontal to the upper layer 2 became 50%. To the upper layer conducting part 4a of the upper layer 2, an upper layer electric wire 9a is connected electrically, to the upper layer conducting part 4b, an upper layer electric wire 9b is connected electrically, and, to the upper layer conducting part 4c, an upper layer electric wire 9c is connected electrically. To the lower layer conducting part 6 of the lower layer 3, a lower layer electric wire 10a is connected electrically, and each of the upper layer electric wire 9 and the electric wire 10 is connected with a controller (corresponding to a controller described in the claim) not illustrated.
As a representative, the case where the linking string 8a connected to the upper layer conducting part 4a is caused to generate heat is explained. When a prescribed voltage is applied between the upper layer electric wire 9a and the lower layer electric wire 10a by the controller, the linking string 8a generates heat because it has a high electric resistivity. As the result of evaluating temperature caused by heat generation under conditions of temperature at 25° C. and humidity of 60% RH in a constant-temperature bath while setting the applying voltage to be 12 V, the heat generation site of the intermediate heat generation layer 8 was warmed to 40° C. On the other hand, temperatures of the upper layer conducting part 4a and the lower layer conducting part 6a were 25° C. as the power was supplied.
In the upper layer conducting part 4 and the lower layer conducting part 6 having a sufficient width, because the electric resistance does not become high, the heat generation when the voltage is applied is suppressed. Therefore, the warming of sites other than the selected warming site can be suppressed, and it becomes possible to control the warming so that the cloth-like heater 1 has an intended temperature distribution.
The upper layer 2, the upper layer conducting part 4 and the upper layer non-conducting part are the same as those in the first embodiment. The lower layer 3 is formed of a polyester fiber, the lower layer conducting part 6 includes a plurality of lower layer conducting parts 6a, 6b, 6c—having a width of 200 mm and a length of 10 mm formed while coating an electroconductive paste (DOTITE, manufactured by Fujikura Kasei Co., Ltd.) on the lower layer 3, and the lower layer non-conducting part 7 denotes a part having a width of 200 mm and a length of 2 mm in which the electroconductive paste is not coated.
The lower layer conducting part 6 is electrically connected to all the upper layer conducting parts 4 with the linking string 8a, and, when seen from the upper side of the seat, the side of the upper layer conducting part 4 along the longitudinal direction and the side of the lower layer conducting part 6 along the longitudinal direction are arranged so as to intersect each other. Typically, the upper layer conducting part 4 and the lower layer conducting part 6 are arranged so that the longitudinal directions thereof are orthogonal to each other.
To the lower layer conducting part 6a, the lower layer electric wire 10a is connected electrically, to the lower layer conducting part 6b, the lower layer electric wire 10b is connected electrically, and, to the lower layer conducting part 6c, the lower layer electric wire 10c is connected electrically. Each of the upper layer electric wire 9 and the electric wire 10 is connected with a controller (corresponding to a controller described in the claim) not illustrated.
As a representative, the case where the linking string 8a connected to the upper layer conducting part 4a and the lower layer conducting part 6a is caused to generate heat is explained. When a prescribed voltage is applied between the upper layer electric wire 9a and the lower layer electric wire 10a by the controller, the linking string 8a generates heat because it has a high electric resistivity. As the result of evaluating temperature caused by heat generation under conditions of temperature at 25° C. and humidity of 60% RH in a constant-temperature bath while setting the applying voltage to be 12 V, the heat generation site of the intermediate heat generation layer 8 was warmed to 41° C. On the other hand, temperatures of the upper layer conducting part and the lower layer conducting part, which are not heat generation sites, were 25° C.
In the upper layer conducting part 4 and the lower layer conducting part 6 that have sufficient width, because the electric resistivity does not become high, the heat generation when a voltage is applied is suppressed. Therefore, warming in sites other than the selected warming site can be controlled, and it becomes possible to control the warming so that the cloth-like heater 1 has an intended temperature distribution.
As a third embodiment of the present invention, as the electroconductive polymer fiber used for the linking string 8a in the first embodiment, an electroconductive polymer fiber, which was formed by coating a PVA solution prepared by dispersing carbon black (manufactured by Mitsubishi Chemical Corporation) in 20% by weight on a polyester fiber so as to give 50:50 in the cross-sectional area ratio, was used. The electric resistivity was 100 Ω·cm to give the same effect as that in the first embodiment, and the heat generation site of the intermediate heat generation layer 8 was warmed to 38° C. On the other hand, temperatures of the upper layer conducting part and the lower layer conducting part, which are not the heat generation sites, were 25° C.
As a fourth embodiment of the present invention, as the electroconductive. polymer fiber used for the linking string 8a in the first embodiment, a silver-coated fiber was used. The electric resistivity was 0.01 Ω·cm to give the same effect as that in the first embodiment, and the heat generation site of the intermediate heat generation layer 8 was warmed to 42° C. On the other hand, temperatures of the upper layer conducting part and the lower layer conducting part, which are not the heat generation sites, were 25° C.
As a fifth embodiment of the present invention, as the electroconductive polymer fiber used in the first embodiment, an electroconductive polymer fiber, which was formed by coating a coating solution prepared by dispersing zinc oxide (ZnO) in PVA in 20% by weight on a polyester fiber so as to give 50:50 in the cross-sectional area ratio, was used. The electric resistivity was 10 Ω·cm to give the same effect as that in the first embodiment, and the heat generation site of the intermediate heat generation layer 8 was warmed to 39° C. On the other hand, temperatures of the upper layer conducting part and the lower layer conducting part, which are not the heat generation sites, were 25° C.
As a sixth embodiment of the present invention, as the electroconductive polymer fiber used for the linking string 8a in the first embodiment, an electroconductive polymer fiber, which was formed by coating a water dispersion of PEDOT/PSS on a polyester fiber so as to give 50:50 in the cross-sectional area ratio, was used. The electric resistivity was 1 Ω·cm to give the same effect as that in the first embodiment, and the heat generation site of the intermediate heat generation layer 8 was warmed to 39° C. On the other hand, temperatures of the upper layer conducting part and the lower layer conducting part, which are not the heat generation sites, were 25° C.
As a seventh embodiment of the present invention, as the electroconductive polymer fiber used for the linking string 8a in the first embodiment, a fiber having a diameter of about 10 μm, which was formed by a wet spinning method using a 5% polypyrrole aqueous solution (manufactured by Aldrich) as an electroconductive polymer, was used. The electric resistivity was 1 Ω·cm to give the same effect as that in the first embodiment, and the heat generation site of the intermediate heat generation layer 8 was warmed to 38° C. On the other hand, temperatures of the upper layer conducting part and the lower layer conducting part, which are not the heat generation sites, were 25° C.
The evaluation results for the first to seventh embodiments are listed in Table 1.
Incidentally, the cloth-like heater 1 of the present invention was explained while taking the embodiments as examples. It is not limited, however, to these embodiments but can employ various other embodiments in the range not deviating from the purport of the present invention. For example, it can be applied not only to a seat of a car but also to a cover of a cushion, an electric carpet, etc. As electroconductive raw materials for use in the present invention, any of wires of such metal as gold, silver, copper or nichrome, particles including a carbon-based material such as carbon or graphite or a semiconductor such as a metal or metal oxide, an electroconductive polymer such as acetylene-based one, heterocyclic 5-membered ring-based one, phenylene-based one or aniline-based one may be employed.
As examples of the carbon-based materials as electroconductive materials, in addition to those generally offered commercially such as fiber bodies made of carbon (Torayca, manufactured by Toray; Donacarbo, manufactured by Osaka Gas Chemicals Co., Ltd. etc.), carbon fibers, fibers spun with carbon powder etc. blended, etc. may also be used. On the other hand, examples of the particles used as an electroconductive material include carbon-based powder such as carbon black and Ketjenblack, carbon-based fibers, and metal fine particles such as iron and aluminum, and, furthermore, tin oxide (SnO2), zinc oxide (ZnO) etc. as semi-electroconductive fine particles.
The electroconductive polymer fiber of the present invention denotes those excluding metals among the above-mentioned electroconductive raw materials. Those made of single material selected from these, those the surface of which is covered with the material by evaporation, coating or the like, those in which the material is used as the core material and the surface is covered with another material, etc. can be used. Among these, from the viewpoint of easy availability in the market, specific gravity etc., as the electroconductive raw material, the use of carbon fiber or carbon powder is desirable. Furthermore, there is no particular limitation on whether the electroconductive raw material includes only one raw material or a plurality of raw materials.
The upper layer 2 and the lower layer 3 themselves are preferably formed from fibers in order that air permeability is given, but the upper layer conducting part 4 and the lower layer conducting part 6 may be formed by coating uniformly an electroconductive paint etc. on the upper layer 2 and the lower layer 3 in a belt shape or over the whole surface. Examples of the electroconductive paints include DOTITE manufactured by Fujikura Kasei Co., Ltd., etc. From the viewpoint of avoiding an uncomfortable feeling as the cloth-like heater caused by partial variation in hardness, as the upper layer conducting part 4 and the lower layer conducting part 6, it is also possible to use a metal wire or an electroconductive fiber, for example, a twisted wire formed by twisting such metal as nickel, having approximately the same cross-sectional area as that of the fiber forming the upper layer 2, the lower layer 3 or the intermediate heat generation layer 8.
For the upper layer non-conducting part 5 and the lower layer non-conducting part 7, the use of fiber including such commodity resin as polyamide such as nylon 6 and nylon 66, polyethylene terephthalate, polyethylene terephthalate containing a copolymerization component, polybutylene terephthalate, polyacrylonitrile, etc. singly or in mixture is preferable from the viewpoint of cost and practicality. Furthermore, the shape of the upper layer 2 and the lower layer 3 brings about no particular problem, only if it forms a cloth having air permeability, but the use of a woven cloth, a nonwoven cloth, knitted goods or the like including the above-described generally used fiber is preferable from the viewpoint of fixing the intermediate heat generation layer and also from the purpose of causing to generate heat and to feel warm.
As a heat generation site controller used for causing an arbitrary site to generate heat, a switching element, a relay or the like generally used is used alone or in combination. The fiber in the present invention denotes, in addition to fiber spun by such a method as melt spinning, wet spinning or electro spinning, those having been slit, such as film cutting. As to the diameter and the width of the fiber on this occasion, one having generally around from several μm to several hundred μm per fiber is preferable from the viewpoint of easy weaving or knitting, softness as a woven cloth or knitted goods after the weaving or knitting, easy handling as texture, in forming woven goods and knitted goods.
By forming these fibers into a bundle (bundle shape) of several tens to several thousands of fibers, handling as a fiber also becomes easy. On this occasion, occurrence of twisting is also allowable. Since metal is a conductor having a particularly low electric resistivity, in order to cause the intermediate heat generation layer to generate heat effectively, it becomes necessary to use an extremely thin fiber or to set the distance between the upper layer and the lower layer to be large. When a thin fiber is used, even if it is intended to cause an arbitrary site or area to generate heat, heat is generated approximately at a point and, further, the air around the metal fiber works as a heat-insulating layer. Therefore, it becomes difficult to obtain the warming effect. When setting the distance between the upper layer 2 and the lower layer 3 to be large, the softness of the metal fiber becomes a drawback, and the metal fiber alone cannot support pressure in the compression direction of the cloth to lead to the mixing of another non-electroconductive fiber. As the result, a heat-insulating layer is formed to lower the heat generation efficiency.
Those in which these electroconductive raw materials are dispersed in or coated for aforementioned materials used for general fibers, that is, polymers, those obtained by forming these themselves into fibers, etc. are called electroconductive polymer fibers. In particular, the use of an electroconductive polymer fiber using a semiconductor, an electroconductive polymer or a carbon fiber as an electroconductive raw material is suitable. The blending amount of these electroconductive raw materials in the electroconductive polymer fiber is preferably from 0.5 to 30% by volume. When the blending amount of these electroconductive raw materials is less than 0.5% by volume, since the amount of the electroconductive raw materials mixed is small, the performance is substantially not changed from that of the case where no raw material is added and only the cost increases, which is not preferable. When the blending amount is more than 30% by volume, in the case where the raw material is mixed into a matrix resin, since the viscosity of the resin to be mixed increases when it is molten, the spinning property furthermore greatly lowers and fiber formation tends to be difficult.
For these matrix resins, the use of fiber including such commodity resin as polyamide such as nylon 6 and nylon 66, polyethylene terephthalate, polyethylene terephthalate containing a copolymerization component, polybutylene terephthalate, polyacrylonitrile, etc. singly or in mixture is preferable from the viewpoint of cost and practicality. It is also preferable that these electroconductive polymer fibers are coated with another polymer.
By giving the coating to the electroconductive polymer fiber, it becomes possible to improve the strength and durability of the electroconductive polymer fiber and to cause a stable heat generation performance. The coating amount may be determined in the range not disturbing the above-mentioned performance, and preferably the coating material occupies the cross-sectional area of around from 10 to 80% relative to the cross-sectional area of the electroconductive polymer fiber, more preferably around from 20 to 50%.
As other ways for obtaining the above-mentioned performance, it is also preferable to give a cross-sectional shape of a core-sheath type, a side-by-side type, or a sea-island type formed by combining the electroconductive polymer fiber with another polymer in the step of obtaining the electroconductive polymer fiber or in the previous step of weaving or knitting after the fiber formation. In general fiber materials, as illustrated in
The intention of the present invention is to actualize the above-mentioned function by combining the devising of a fiber structure and the devising of a material for aiming at the improvement in heat generation performance, in addition to the devising for changing these static characteristics of a fiber. Among these structures, to form into the core-sheath type is preferable. The core-sheath type referred to here denotes the case where the ratio of the core/sheath area to the cross-sectional area is nearly 50%, which can cause the function to express best when taking the balance of the strength/heat generation performances of a fiber into consideration.
As to the range of electric resistivity of an electroconductive raw material for obtaining the heat generation function mentioned above, the use of one having around from 10−3 to 102 Ω·cm is preferable. This is because the electroconductive polymer fiber works as an electric resistance body when formed into woven goods or knitted goods and, when the resistance value is too small, the conducting part generates heat, which makes it difficult to warm an arbitrary site. On the other hand, the resistivity exceeding the range makes a current for generating heat difficult to flow, which makes it impossible to give sufficient heat generation. By setting the electric resistivity to be around from 10−2 to 101 Ω·cm as a more preferable range, it is possible to express the heat generation function more effectively.
Among the electroconductive polymer fibers that show an electric resistivity, in particular, electroconductive polymer fibers containing any of electroconductive polymers of polypyrrole and/or PEDOT/PSS and/or polyaniline and/or PPV are more preferable.
Furthermore among these, examples of materials easily obtainable as a fiber include PEDOT/PSS (Clevios P (registered), manufactured by Bayer) in which poly(4-styrenesulfonate) (PSS) is doped in poly(3,4-ethylenedioxythiophene) (PEDOT) being a thiophene-based electroconductive polymer, phenylene-based polyparaphenylene vinylene (PPV), pyrrole-based polypyrrole, etc.
Among the electroconductive polymers, these materials are preferable as materials that can easily be formed into a fiber by such a method as wet spinning or electrospinning and satisfy the electro resistivity mentioned above. For example, in the case of thiophene-based, pyrrole-based and aniline-based polymers, manufacturing by wet spinning is possible. For example, by extruding a water dispersion liquid of PEDOT/PSS (Clevios PR by Bayer) from a cylinder into acetone, it is possible to easily obtain the electroconductive polymer fiber.
By adopting such a process, it is possible to easily manufacture the electroconductive polymer fiber for forming the cloth-like heater. In the present invention, the linking string 8a is not necessarily linked in one string at a linking part 11, but, as illustrated in
In connection with United States designation, the present international patent application claims the benefit of priority under 35 U.S.C. 119(a) to Japanese Patent Application No. 2011-269636 filed on Dec. 9, 2011 whose disclosed contents are cited herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-269636 | Dec 2011 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/079278 | 11/12/2012 | WO | 00 | 6/5/2014 |
