HEATING YARN AND WOVEN OR KNITTED FABRIC USING THIS HEATING YARN

Abstract

A heating yarn includes an insulating yarn and a conductive yarn that is wound around the insulating yarn. The conductive yarn has an insulating core yarn and a plated layer (such as a copper plated layer) formed on a peripheral surface of the core yarn, and the core yarn is a high elasticity yarn (such as an aramid fiber) with an initial tensile resistance of 4.9 GPa or higher. Moreover, the heating yarn is woven in or knitted into the woven or knitted fabric as part of the constituent yarn.

Description

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2010-235846 filed on Oct. 20, 2010 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a heating yarn and a woven or knitted fabric that uses this heating yarn. More specifically, the invention relates to a heating yarn that uses a high elasticity yarn having a specified initial tensile resistance as a core yarn of a conductive yarn, such that when the heating yarn in which this conductive yarn is wound around the peripheral surface of an insulating yarn is flexed or when tensile stress is applied to the heating yarn or the like, the core yarn will not easily stretch or otherwise deform, so the plated layer formed on the peripheral surface of the core yarn, will not crack and the conductive yarn will not break. The invention also relates to a woven or knitted fabric that can be used in a variety of applications as a heater member, in which this heating yarn is woven or knitted in as part of the constituent yarn.

2. Description of Related Art

A variety of flat heating bodies have been used as heater members and the like for vehicle seats. One such known heating body is a heating seat in which heating wires and insulating wires are alternately arranged, and the insulating wires that are warp yarns are woven in with electrode wires (see Japanese Patent Application Publication No. 7-161456 (JP-A-7-161456), for example). In this heating seat, heating wires in which stainless steel resistance heating wires as the heating body are wound around insulating wires formed by synthetic fiber twisted yarns are used. Also, for a seat of a vehicle, particularly a seat of a passenger vehicle or the like, a seat that can warm an occupant during wintertime or the like by a heater member being adhered to the back surface of cover material is known. One example of a heater member used in this kind of a seat is a seat heater woven from a plurality of conductive warp yarns that generate heat when current passes through them, and a plurality of non-conductive weft yarns that are electrically insulated from the conductive warp yarns, in which the conductive warp yarns are arranged closer together on the side opposite a seat back than they are on the seat back side (see Japanese Patent Application Publication No. 2008-67850 (JP-A-2008-67850), for example).

However, in the heating seat described in JP-A-7-161456, stainless steel resistance heating wires are used as the heating body. Therefore, even if stress is distributed by the stainless steel resistance heating wires being wound around the insulating wires, when the heating seat is flexed or when tensile stress is applied to the heating seat or the like, the heating body will also flex and stretch, and as a result, the stainless steel resistance heating wires, i.e., the heating body, may break. Furthermore, when a heating body that is more flexible than the stainless steel resistance heating wires is used, e.g., when a heating body in which a plated layer is formed on the peripheral surface of a polyester fiber or the like is used, the heating body may stretch and the plated layer may crack and peel away when tensile stress or the like is applied. Also, when the heating seat is used in a vehicle seat, as is the case with the seat heater described in JP-A-2008-67850, a fairly large amount of stress is applied to the heater member when an occupant ingresses and egresses. Therefore, a heater member that is more resistant to breaking or the like must be used.

SUMMARY OF THE INVENTION

The invention thus provides a heating yarn that uses a high elasticity yarn having a specified initial tensile resistance as a core yarn of a conductive yarn, such that when a heating yarn is flexed or when tensile stress is applied to the heating yarn or the like, the core yarn will not easily stretch, so a plated layer formed on the peripheral surface of the core yarn will not crack and the conductive yarn will not break. The invention also provides a woven or knitted fabric that is useful as a heater member, in which this heating yarn is woven or knitted in as part of the constituent yarn.

A first aspect of the invention relates to a heating yarn that includes an insulating yarn and a conductive yarn that is wound around the insulating yarn. The conductive yarn has an insulating core yarn and a plated layer formed on a peripheral surface of the core yarn, and the core yarn is a high elasticity yarn with an initial tensile resistance of 4.9 GPa or higher. In this aspect, a resin coating layer may be formed on a surface of the plated layer. Also, the plated layer may be a copper plated layer, and a tin plated layer or a nickel plated layer may be formed on a surface of the copper plated layer. A second aspect of the invention relates to a woven or knitted fabric into which the heating yarn according to the first aspect is woven or knitted.

With the heating yarn according to the first aspect of the invention, a high elasticity yarn that has a specific initial tensile resistance is used as the core yarn of the conductive yarn. The conductive yarn has a high flex resistance and is strong in the length direction. Therefore, when the heating yarn in which this conductive yarn is wound around the insulating yarn is flexed, the core yarn of the conductive yarn will not stretch, so the plated layer formed on the peripheral surface thereof will not crack, and when tensile stress is applied to the heating yarn, the conductive yarn will not break. Also, when the resin coating layer is formed on the surface of the plated layer, the plated layer is protected by the resin coating layer, so oxidation degradation of the plated layer, and a change in the resistance value due to that oxidation degradation, are suppressed, and wear of the plated layer is also suppressed. Moreover, when the plated layer is a copper plated layer, and a tin plated layer or a nickel plated layer is formed on the surface of the copper plated layer, the copper plated layer will be covered, and thus protected, by the plated layer formed of tin or nickel that does not oxidize as easily as copper and has good wear resistance. Therefore, oxidation degradation of the copper plated layer, and a change in the resistance value due to that oxidation degradation, can be suppressed, and wear of the copper plated layer can also be suppressed. With the woven or knitted fabric of the second example embodiment of the invention, the heating yarn of the first aspect is woven or knitted in as part of the constituent yarn, so when the woven or knitted fabric deforms due to stress being applied or the like, the plated layer of the conductive yarn will not crack and the conductive yarn will not break or the like. Accordingly, the woven or knitted fabric is able to maintain good heat generating performance when used as a heater member of a passenger vehicle or the like, for example.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 is a view showing a frame format of a cross-section of a conductive yarn that has a core yarn and a plated layer formed on the peripheral surface of the core yarn, and that is used wound around an insulating yarn;

FIG. 2 is a view showing a frame format of a cross-section of a conductive yarn that has a core yarn, a plated layer formed on the peripheral surface of the core yarn, and a resin coating layer or a plated layer formed on the surface of that plated layer, and that is used wound around an insulating yarn;

FIG. 3A is a side view of a heating yarn in which a conductive yarn is wound in an S direction around an insulating yarn;

FIG. 3B is a side view of a heating yarn in which the conductive yarn is wound in a Z direction around the insulating yarn;

FIG. 4 is a side view of a heating yarn in which a conductive yarn is wound in both the S and Z directions around an insulating yarn;

FIG. 5 is a front view showing a frame format of a knitted fabric into which a heating yarn of an example embodiment of the invention is knitted as part of a constituent yarn;

FIG. 6 is a perspective view showing a frame format of a vehicle seat in which a woven or knitted fabric of an example embodiment of the invention in arranged as a heater member on a back surface of cover material.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, the invention will be described in detail with reference to FIGS. 1 to 6. The description here is illustrative in purpose and is simply intended to describe example embodiments of the invention. The purpose is to provide description of the principle and conceptual characteristics of the invention in the most effective and comprehensible manner possible. Regarding this, there is no intent to give any structural detail of the invention beyond what is necessary to gain a fundamental understanding of the invention. The way in which various modes of the invention are actually embodied is made evident to one skilled in the art by the description together with the drawings.

A heating yarn 10 of one example embodiment of the invention includes an insulating yarn 101 and a conductive yarn 1 that is wound around this insulating yarn 101. The conductive yarn 1 has an insulating core yarn 11 and a plated layer 12 formed on the peripheral surface of the insulating core yarn 11. A high elasticity yarn with an initial tensile resistance of 4.9 GPa or higher is used as the insulating core yarn 11 (see FIGS. 1, 3, and 4).

Examples of the insulating yarn 101 include a yarn made of a synthetic fiber made using a synthetic resin such as polyester or polyamide, a natural fiber of a plant system or an animal system, a regenerated fiber such as rayon, or a semi-synthetic fiber such as acetate, and the like. The insulating yarn is preferably yarn that is made using a synthetic fiber, and more preferably, yarn that is made using a polyester fiber.

Only one of these types of insulating yarn may be used, or two or more types may be used together. Also, filament yarn is preferably used as the insulating yarn. Either multifilament or monofilament may be used, though multifilament is more preferable. Furthermore, the fineness of the insulating yarn is preferably 10 to 2000 dtex, and more particularly 84 to 550 dtex. Also, the insulating yarn may be a textured yarn that has been false twisted, for example. These insulating yarns normally have an insulation property with a specific resistance exceeding 108Ω×cm.

The conductive yarn 1 has the insulating core yarn 11 and the plated layer 12 that is formed on the peripheral surface of the insulating core yarn 11. The heating yarn 10 is formed by this conductive yarn 1 being wound around the insulating yarn 101 (see FIGS. 3 and 4). The heating yarn 10 may be a single covering yarn in which the conductive yarn 1 covers the outer periphery of the insulating yarn 101 in the S direction or the Z direction, or a double covering yarn in which the conductive yarn 1 covers the outer periphery of the insulating yarn 101 in both the S and the Z directions. Also, the actual number of twists is not particularly limited, but with a single covering yarn, as well as with a double covering yarn, the actual number of twists is preferably 50 to 1000 T/m, and more preferably, 100 to 500 T/m. If the actual number of twists is within this range, the heating yarn 10 will be able to heat sufficiently for practical use.

A high elasticity yarn with an initial tensile resistance of 4.9 GPa or higher may be used as the insulating core yarn 11. The high elasticity yarn is strong and does not stretch much, so the core yarn 11 will not easily stretch or otherwise deform when the heating yarn 10 is flexed or tensile stress is applied to the heating yarn 10. As a result, the plated layer 12 will not crack and the conductive yarn 1 will not break.

Yarn such as an industrial polyester yarn or a high-strength polyethylene yarn may also be used as the high elasticity yarn. More preferably, however, a yarn that uses a variety of types of fiber that is very strong, has a high melting point, and is flame retardant, such as a para-type aramid fiber, a meta-type aramid fiber, a polyarylate fiber, a poly-para-phenylene benzobis oxazole fiber, a polyphenylene sulfide fiber, a polyether ether ketone fiber, a polyimide fiber, or a PAN-based carbon fiber, is used. The initial tensile resistance of the high elasticity yarn is 4.9 GPa or higher, and preferably 4.9 to 600 GPa, and more preferably 54 to 280 GPa. The initial tensile resistance of the high elasticity yarn is a value measured based on JIS L10138.10.

Specific examples of a more preferable high elasticity yarn is a high elasticity yarn made using a para-type aramid fiber with an initial tensile resistance of 54 to 199 GPa, such as Kevlar (Trademark) by DuPont or Technola (Trademark) by Teijin, a high elasticity yarn made using a polyarylate fiber with an initial tensile resistance of 74 to 104 GPa, such as Vectran (Trademark) by Kuraray, and a high elasticity yarn made using a poly-para-phenylene benzobis oxazole fiber with an initial tensile resistance of 180 to 280 GPa, such as Zylon (Trademark) by Toyobo.

The high elasticity yarn is a filament yarn, which may be multifilament or monofilament, but multifilament is preferable. Also, the single yarn fineness is not particularly limited, but is preferably 0.1 to 30 dtex, and more preferably 1 to 20 dtex. A single yarn fineness of 0.1 to 30 dtex enables the conductive yarn 1 to be easily wound around the insulating yarn 101.

The plated layer 12 is formed on the peripheral surface of the high elasticity yarn that is the insulating core yarn 11, thereby forming the conductive yarn 1 (see FIG. 1). This plated layer 12 is formed by a non-electrolytic plating method, and preferably uses a metal with good conductivity, such as copper, silver, or nickel. A plated layer that uses copper, which is inexpensive, and a plated layer that uses nickel, which has good corrosion resistance, are even more preferable. The thickness of this plated layer 12 may be set according to the type of metal, and the use of the woven or knitted fabric or the like. For example, the thickness may be 0.1 to 10 μm, and more preferably 0.3 to 5 μm. Also, when the plated layer 12 is a copper plated layer, in particular, there may be oxidation degradation, and copper is a metal with low hardness, so it is not necessarily sufficiently wear resistant. Therefore, when a copper plated layer in particular is used, a covering layer 13 that is both oxidation resistant and wear resistant is preferably formed on the surface of the copper plated layer to protect it (see FIG. 2).

As described above, the covering layer 13 for inhibiting oxidation degradation and wear of the plated layer 12 is not particularly limited. For example, a resin coating layer 13 may be formed on the surface of the plated layer 12. Accordingly, the plated layer 12 is protected by the resin coating layer 13, so the conductive yarn 1 is able to maintain good conductivity. Moreover, when a connecting member for applying current is connected near both end portions of a heater member made from a woven or knitted fabric using the heating yarn 10 of the invention, the resin coating layer can be peeled away to expose the plated layer, so a reliable electrical connection can be made. Also, the resin used to form the resin coating layer is not particularly limited, and may be a polyurethane resin, a silicon resin, or a polyester resin. A polyurethane resin is preferable from the perspective of durability.

The thickness of the resin coating layer 13 may be set according to the type of resin and the durability, and the use of the woven or knitted fabric. For example, the thickness of the resin coating layer 13 may be 0.1 to 50 μm, or more preferably, 0.5 to 10 μm. Furthermore, the method of forming the resin coating layer 13 is not particularly limited. For example, a method whereby the conductive yarn 1 in which the plated layer 12 has been formed on the peripheral surface of the core yarn 11 is immersed in a resin-dispersed liquid or passed through the liquid such that resin adheres to it, and then heated and then cooled such that the resin becomes fixed may be used. Also, resin powder or melted resin may be applied or fused to the conductive yarn, and then if necessary, heated and then cooled such that the resin becomes fixed.

Furthermore, when the plated layer 12 formed on the peripheral surface of the insulating core yarn 11 is a copper plated layer, a plated layer (i.e., the coating layer 13) made using a metal that is more oxidation resistant and wear resistant than copper may be formed as the protective coating layer 13 on the surface of the copper plated layer by a non-electrolytic plating method or an electrolytic plating method. Examples of this kind of plated layer are a tin plated layer and a nickel plated layer. Tin and nickel are preferable because they do not oxidize as easily as copper does. The thickness of this plated layer (i.e., the coating layer 13) may be set according to the type of metal, and the use of the woven or knitted fabric. For example, the thickness of the plated layer may be 0.1 to 10 μm, and more particularly 0.3 to 5 μm.

The woven or knitted fabric of the second example embodiment of the invention is a woven or knitted fabric into which the heating yarn of the example embodiment of the invention is woven or knitted as part, of the constituent yarn, and may be a woven fabric or a knitted fabric. The woven or knitted fabric of the second example embodiment is useful as a flat heater member because part of the constituent yarn is the heating yarn of the example embodiment of the invention. The woven or knitted fabric of the second example embodiment may be used as a heating member in a variety of applications, such as a seat heater, an electric blanket, an electric carpet, and a snow melting heater. The woven or knitted fabric of the invention may also be used as a sensor, an electrode, or an antenna.

Hereinafter, a case in which the woven or knitted fabric according to the second example embodiment of the invention is a knitted fabric 2 that is used as a heater member of a vehicle seat 3 will be described in detail (see FIGS. 5 and 6). This knitted fabric 2 (see FIG. 5) is not limited to a weft knit or a warp knit, though a knitted fabric having a weft knit structure is preferable. A knitted fabric having a weft knit structure can be obtained by forming loops in a yarn supplied in a course direction and sequentially interlocking them in a wale direction. This type of weft knitting is not particularly limited, and ‘may either be circular knitting or flat knitting. Also, the type of’ weft knitting machine is also not particularly limited. That is, a circular knitting machine or a flat knitting machine may be used. In either case, a single bed knitting machine or a double bed knitting machine may be used. Moreover, examples of the knitting machine are a plain knitting machine or a Jacquard knitting machine, and either may be used.

The interval between a plurality of heating yarns 10 that are knitted in as part of the constituent yarn is not particularly limited (see FIG. 5). This interval is preferably approximately 1 to 100 mm, and more preferably approximately 5 to 60 mm. Also, the arrangement of the heating yarns in the wale direction of the knitted fabric [the longitudinal direction in a seat cushion of a vehicle seat (see the seat cushion 31 in FIG. 6) and the vertical direction in a seat back (see the seat back 32 in FIG. 6)] is not particularly limited. That is, the heating yarns may be knitted in at substantially equidistant intervals or the intervals may not be equidistant. If the heating yarns are knitted in at substantially equidistant intervals, the entire seat cushion and seat back can be warmed more evenly. On the other hand, if there is a desire to warm a specific area of a seated person, such as the thighs, shoulders, or back, for example, more thoroughly, the heating yarns may be arranged relatively close together at the area corresponding to the heating member (i.e., see heating members 331 and 332 in FIG. 6), and relatively farther apart at other areas.

Moreover, the heating yarns may be such that only one heating yarn is knit in between non-heating yarns, or a plurality of heating yarns may be knit in between non-heating yarns, e.g., 2 to 10, and more particularly 2 to 5 heating yarns may be knit in consecutively between non-heating yarns. In this case as well, the arrangement of the plurality of heating yarns knitted in consecutively in the wale direction of the knitted fabric may be a substantially equidistant arrangement or not an equidistant arrangement. In this way, whether the seat cushion and the seat back of the vehicle seat are warmed evenly, or whether a specific area is warmed more thoroughly, can be adjusted according to the interval at which the heating yarns are arranged, and the number of heating yarns that are consecutively knitted in, and the like.

With this heater member, the connecting member for connecting the heating yarns to an ECU are connected near both end portions of each heating yarn. Power is supplied from a power supply by a signal from the ECU, such that the heating yarns are heated, causing the heater member to rise in temperature. At this time, the non-heating yarns, and the insulating yarns and the conductive yarns (i.e., the core yarns, the plated layer, and the resin coating layer and the like) of the heating yarns, that are knitted in are mixed near both end portions of the heater member. Therefore, when the non-heating yarn and the resin coating layer are provided, at least the resin coating layer must be removed before attaching the connecting member.

The method for removing the non-heating yarn is not particularly limited. For example, the non-heating yarn and the like may be efficiently removed by heating the areas near both end portions of the heater member such that the non-heating yarn melt or burn off. Therefore, of the insulating yarn and the core yarn of the conductive yarn that form the heating yarn, it is preferable that at least the core yarn be more heat resistant than the non-heating yarn. In other words, it is preferable that the temperature at which the core yarn will melt from being heated, or the decomposition temperature in a case in which the core yarn does not melt, be higher than that of the non-heating yarn. That is, it is preferable that the core yarn (or the heating yarn) have a higher melting point than the non-heating yarn, or that the core yarn (or the heating yarn) not burn as easily as the non-heating yarn. Even if the core yarn is a yarn that will melt, the non-heating yarn can easily be removed by being burned off. Also, even when both the non-heating yarn and the core yarn and the like are yarns that will melt, at least the core yarn, from among the insulating yarn and the core yarn of the conductive yarn that form the heating yarn, is preferably a yarn that does not burn as easily as the non-heating yarn.

As described above, when removing both end portions of the heating yarn, the core yarn is a flame retardant, high elasticity yarn, so the melting point and the decomposition temperature can be raised higher than they are with a polyester fiber or the like that is often normally used as non-heating yarn. Therefore, the non-heating yarn can easily be removed by heating it at a temperature at which it will melt and the core yarn will not melt. Meanwhile, a polyester fiber or the like is also often used as insulating yarn around which the conductive yarn is wound. In this case, this insulating yarn can be removed just like the non-heating yarn, according to the difference in the melting points.

The limiting oxygen index (LOI) measured in compliance with JIS K7201 and JIS L1091 (1999) 8.5 E-2 may be used as the combustibility index. The LOI of the flame retardant, high elasticity yarn used as the core yarn is normally 25 or higher, and more preferably 28 to 68. On the other hand, the LOI of the polyester fiber that forms the non-heating yarn is normally 18 to 20, and the LOI of an aliphatic polyamide fiber such as Nylon 6 is normally 20 to 22. Both are considerably lower than that of the flame retardant, high elasticity yarn, so the non-heating yarn burns more easily than the high elasticity yarn does, making them easily able to be removed by being burned off.

The heating method is not particularly limited. Some examples include a method according to exothermal heating that involves contacting the yarn or the like with a heating member, and a method that involves emitting a laser such as a carbon dioxide laser, a YAG laser, or an excimer laser. The method of emitting a laser is preferable.

If the method of emitting a laser is used, the strength and output of the laser can be easily adjusted to the level needed to melt or burn off the non-heating yarn by the material and the like of the non-heating yarn, thus making it possible to efficiently remove the non-heating yarn and the like. Moreover, the laser may be emitted from either surface of the heater member. Emitting the laser with the focal point offset with respect to the surface of the heater member temporarily enables a wider area to be worked. Also, the non-heating yarn and the like is able to be removed in strips after emitting the laser back and forth in the wale direction. Further, spraying an inert gas, such as nitrogen gas or helium gas, while emitting the laser makes it possible to prevent, or at least reduce, oxidation degradation of the plated layer that occurs due to overheating.

Hereinafter, a first example of the invention will be described in detail. A 330 dtex, 72 filament polyethylene terephthalate (hereinafter referred to as “PET”) multifilament false twist textured yarn was used as the insulating yarn. Also, a 28 dtex, 5 filament polyarylate fiber (high elasticity yarn, initial tensile resistance of 74 GPa, trade name Vectran by Kuraray) was used as the core yarn. A copper plated layer 0.30 μm thick was formed on the peripheral surface of this core yarn, and then a nickel plated layer 0.20 μm thick was formed on the surface of the copper plated layer. This core yarn with a copper plated layer and a nickel plated layer was used as the conductive yarn. The heating yarn was manufactured by covering the surface of the insulating yarn with 500 T/m of the conductive yarn in the S and Z directions. Next, the conductive yarn was thermoset to prevent it from coming out of its predetermined position. In this way, a double covering yarn with a resistance value of 1.0Ω per unit length (1 cm) was manufactured.

Then, a double jersey knitted fabric was knitted using a both-side needle selection machine (Precision Fukuhara Works, Ltd., model V-LEC4DS, 30 inch diameter unit pattern, 18 gauge, 48 feeders) as the weft knitting machine. Twenty-four strands of yarn were used, some of which were heating yarn (the double covering yarn). Also, three types of other wire [first wire: spun-dyed PET textured yarn (color: beige, 334 dtex, 48 filaments), second wire: PET textured yarn, (normal texture, 167 dtex, 48 filaments), and third wire: PET textured yarn (strong textured yarn, 334 dtex, 48 filaments)] were used.

Also, for knitting, 24 of the 48 feeders were used as feeders, and the first wire was supplied from feeders with feeder numbers of (1 and multiples of 4+1). Also, the second wire was supplied from feeders with supply path numbers of (even numbers excluding 4 and multiples of 4+3). Further, the heating yarn was supplied from the feeder of feeder number (3), and the third wire was supplied from the feeder of feeder number (4). The knit structure organization chart of 9 to 12 was repeatedly used for feeder numbers 13 to 24. The interval between heating yarns was 10 mm. Also, visual monitoring was performed to check whether or not there were any breaks in the heating yarn when knitting the knitted fabric, and no breaks were observed.

Then, the knitted fabric knitted in this way was first refined (i.e., desized at 80° C.), then subjected to an intermediate thermoset (at 150° C. for 1 minute), and then resin processed (immersed in an aqueous dispersion in which wax and polyurethane resin have been dispersed, and then dried). Then one side of the knitted fabric was coated with a flame retardant coating, after which it was subjected to a finishing set. Also, a pad material (i.e., a polyurethane resin sheet 5 mm thick) and a back base cloth (half tricot of 15 dtex Nylon 6) were arranged in that order on the back side of the cloth. Then the other surface of the knitted fabric processed as described above was laid over the back base cloth, and a laminated member for a seat was manufactured by integrating the two together by a frame lamination method.

Then, a cover piece of predetermined dimensions was cut out as a main member of the seat sitting surface by emitting a laser on the laminated member for a seat. To emit the laser, a carbon dioxide laser processing machine (by Mitsubishi; Type: 2512H2; Transmitter type: 25SRP; Laser rated output: 1,000 W) was used. The emitting conditions were: Speed: 500 mm/minute; Output: 30 W; Duty: 7.7%; and Frequency: 200 Hz. Furthermore, at a position 15 mm from the end portion of both ends of the cover piece, the laser was emitted from the back side (i.e., the side where the knitted fabric was overlaid), swept in the length direction, and melted, thus cutting, the pad material, the back base cloth, the insulating yarn, and the first to third wires. The emitting conditions were: Speed 1,500 mm/minute; Output: 20 W; Duty: 7.7%; and Frequency: 200 Hz. The conductive yarn was not melted by the laser emission, but instead remained. The plated layer was also not affected by the laser emission.

Next, the end portions of the conductive yarn was exposed by peeling away both end portions of the cover piece and removing the pad material, the back base cloth, the insulating yarn, and the first to third wires. Further, a strip of connecting member was sewn onto the surface of the cover piece, and then the conductive yarn and the connecting member were sewn together.

A second example of the invention will be described. For the heating yarn, heating yarn just like that in the first example was used, and this was used as a first weft yarn. Also, for another wire, a dyed-in PET memory-twisted textured yarn (color: light gray; 167 dtex/2; 144 filaments) was used as a warp yarn and a second weft yarn. Also, using a Jacquard knitting machine, the warp yarn was prepared (124 strands/2.5 cm), and then a cloth raw fabric with a weft yarn density of 50 strands/2.54 cm was woven by punching in the first weft yarn and the second weft yarn.

Then, the cloth raw fabric was refined (i.e., desized at 80° C.) and subjected to an intermediate thermoset (at 150° C. for 1 minute), and then a backing agent was adhered to the side that would be the back side of the finished product and dried, thus creating cloth. The main components of the backing agent used were an acrylic-type polymer, made by copolymerizing butyl acrylate and acrylonitrile, and a flame retardant. As, the amount of backing agent applied was 45 g/m2, and the drying conditions were 1 minute at 150° C.

The finished density of the cloth was a warp of 135 strands/2.54 cm, a weft of 55 strands/2.54 cm, and 5% modulus of the cloth was 98 N for the warp and 33 N for the weft. Then, a pad material (i.e., a polyurethane resin sheet 5 mm thick) and a back base cloth (half tricot of 15 dtex Nylon 6) were arranged in that order on the back side of the cloth. Then a laminated member for a seat was manufactured by integrating the two together by a frame lamination method. Next, just as in the first example, the end portions of the conductive yarn were exposed, a strip of connecting member was attached by sewing to the surface of the cloth, and then the conductive yarn and the connecting member were sewn together.

A third example of the invention will be described. 330 dtex, 72 filament PET multifilament memory-twisted textured yarn was used as the insulating yarn, Also, 14 dtex, single filament polyacrylate fiber (high elasticity yarn; initial tensile resistance of 74 GPa; trade name Vecry by Kuraray) was used as the core yarn. A copper plated layer 0.38 μm thick was formed on the peripheral surface of this core yarn. Then, a dispersion liquid in which a polyurethane-based resin had been dispersed in a water-based medium and adjusted was applied to the surface of the copper plated layer formed on the peripheral surface of the core yarn and dried, thereby forming a resin coating 1.0 μm thick. This core yarn with a copper plated layer and resin coating was used as the conductive yarn. The heating yarn was manufactured by covering the surface of the insulating yarn with 500 T/m of the conductive yarn in the S and Z directions. Next, the conductive yarn was thermoset to prevent it from coming out of its predetermined position. In this way, a double covering yarn with a resistance value of 2.8Ω per unit length (1 cm) was manufactured. Then, cloth raw fabric was manufactured just as in the second example using this double covering yarn (i.e., the heating yarn) as the first weft yarn. Next, just as in the second example, the cloth and the laminated member for a seat were manufactured, and the end portions of the conductive yarn were exposed and the conductive yarn and the connecting member were sewn together in the same way.

Then, a seat cover was manufactured by sewing side material to an outer side of one of the woven or knitted fabrics obtained by the first to the third examples, and this seat cover was fit onto a seat cushion. Also, for comparison, a seat cover of the same structure, other than that the heated yarn was not woven or knitted into the woven or knitted fabric and the end portions of the conductive yarn were not connected to the connecting member, was manufactured and fit on a seat cushion. In this case, a seat heater in which a conductive wire made of a resin-covered 1.5 mm diameter nichrome wire was adhered to a nonwoven cloth surface was placed under an expanded polyurethane sheet 5 mm thick and over a pad made using a polyurethane resin sheet.

There was no difference in the cut of the vehicle seat (see the vehicle seat 3 in FIG. 3) that used the woven or knitted fabric (i.e., a woven fabric having a weft weave structure; see the knitted fabric 2 in FIG. 5) of the second example embodiment of the invention manufactured in this way as the heater member, and the comparative seat. However, regarding the sitting comfort of the seat cushion (see the seat cushion 31 of the vehicle seat 3 in FIG. 6), discomfort from the hardness of the conductive wire was felt with the comparative seat, while no discomfort at all was felt with the seat using the woven or knitted fabric of the second example embodiment of the invention as the heater member. In fact, the seat using the woven or knitted fabric of the second example embodiment as the heater member had a good feel to it.

The description given above is merely for descriptive purposes and should in no be way construed as limiting the invention. While the invention is described giving classic examples and example embodiments, the language used in the descriptions and the drawings of the invention is understood to be in no way limiting, but rather descriptive and exemplary. As described in detail here, the example embodiments may be modified within the scope of the accompanying claims for patent, without departing from the spirit and scope of the invention. Here, references are made to the specific structure, material, and examples described in detail of the invention, but the invention is not intended to be limited to the descriptions here. Rather, the invention covers all functionally equivalent structures, methods, and uses within the scope of the accompanying claims for patent.

The invention may be used in the technical field of heating seats that can generate heat and rise in temperature. In particular, the invention is useful in the commercial product field of heater members that can be used out of doors, such as in a seat of a vehicle such as a passenger vehicle.

Claims

1. A heating yarn comprising:

an insulating yarn; and

a conductive yarn that is wound around the insulating yarn,

wherein the conductive yarn has an insulating core yarn and a plated layer formed on a peripheral surface of the core yarn, and the core yarn is a high elasticity yarn with an initial tensile resistance of 4.9 GPa or higher.

2. The heating yarn according to claim 1, wherein the core yarn is a high elasticity yarn with an initial tensile resistance of 4.9 to 600 GPa, inclusive.

3. The heating yarn according to claim 1, wherein the core yarn is a high elasticity yarn with an initial tensile resistance of 54 to 280 GPa, inclusive.

4. The heating yarn according to claim 1, wherein a resin coating layer is formed on a surface of the plated layer.

5. The heating yarn according to claim 1, wherein the plated layer is a copper plated layer, and a tin plated layer or a nickel plated layer is formed on a surface of the copper plated layer.

6. A woven or knitted fabric into which the heating yarn according to claim 1 is woven or knitted.