KR101843400B1 - Electrode composition for film heater, wiring board for film heater, film heater using the same and method thereof - Google Patents

Abstract

The present invention relates to an electrode composition for a film heater, which is resistant to stress and can reduce a sense of rejection upon contact with a human body; a wiring board for a film heater; a film heater using the same; and a method for manufacturing the film heater. The electrode composition for a film heater according to the present invention comprises a first mixed binder, conductive particles including silver powder and carbon nanotube particles, an organic solvent, and a dispersing agent; and has a density of 2 g/cm^3 or less.

Description

TECHNICAL FIELD The present invention relates to an electrode composition for a film heater, a wiring substrate for a film heater, a film heater using the same, and a method for manufacturing the same,

The present invention relates to a film heater, more particularly, to an electrode composition for a film heater which is robust against stress and can reduce a sense of rejection upon contact with a human body, a wiring substrate for a film heater, a film heater using the same, and a method for manufacturing the same.

BACKGROUND ART [0002] Recently, a variety of electric driving devices driven by electricity due to concerns of depletion of fossil fuels, such as electric vehicles, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (HEVs) PHEV) are being developed. An electric vehicle is an automobile whose main power source is electric energy through a battery without an engine, and no exhaust gas is generated at all. A hybrid electric vehicle is an automobile that uses both an engine and an electric motor, and can reduce the load on the engine to improve energy efficiency. And a plug-in hybrid electric vehicle is a hybrid electric vehicle in that an engine and an electric motor are used together, and a battery is different from a hybrid electric vehicle in that it charges through an external power source through a plug-in.

Despite the growth of the electric drive market, one of the technical challenges is to maximize the heating efficiency in a low temperature environment. The reason is that a battery is used to supply electric power to the electric driving device, because when a hot-wire film heater with a high energy consumption is used, the driving distance is reduced.

In addition, the hot-wire film heater is fixed to a fibrous substrate such as a nonwoven fabric through knitting, which has a high production cost and causes a large number of defects due to disconnection.

Various surface heating techniques have been developed to overcome the problems of heat ray film heaters using such a fiber substrate.

Korean Patent No. 10-1595484 discloses an " area heating element and a manufacturing method thereof " to which the area heating technique is applied.

The surface heat generating element has a film member made of a synthetic resin material, a heat generating sheet formed on one side of the upper surface of the film member, an upper surface of the film member, an electrode member formed on one side of the upper surface of the heat generating sheet, And an insulator formed on an outer surface of the electrode member.

Here, the heat generating sheet is formed by applying a conductive paste prepared by mixing an organic solvent, a binder, a conductive carbon black, a conductive graphite, a dispersant, and a plasticizer to an upper surface of a film member, followed by drying.

However, since the electrode member is formed by adhering a metal such as copper in thin film form, it is susceptible to stress due to the brittleness of the thin film, so that defects may occur due to disconnection of the electrode.

Accordingly, it is an object of the present invention to provide an electrode composition for a film heater, a wiring substrate for a film heater, a film heater using the electrode composition, and a method for manufacturing the electrode composition.

The electrode composition for a film heater according to the present invention comprises a first mixed binder, silver powder and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant, and has a density of 2 g / cm 3 or less.

In the electrode composition for a film heater according to the present invention, the silver powder has a tap density of 2.5 g / cm 3 or less.

In the electrode composition for a film heater according to the present invention, the silver powder includes 50 to 80 parts by weight based on 100 parts by weight of the electrode composition.

In the electrode composition for a film heater according to the present invention, the carbon nanotube particles include 0.2 to 5 parts by weight based on 100 parts by weight of the electrode composition.

In the electrode composition for a film heater according to the present invention, the conductive particles further include graphite particles, and the graphite particles are 0.1 to 5 parts by weight based on 100 parts by weight of the electrode composition.

In the electrode composition for a film heater according to the present invention, the carbon nanotube particles are distributed among the silver powder or the graphite particles to form an electric network.

In the electrode composition for a film heater according to the present invention, the first mixed binder is a mixture of 10 to 150 parts by weight of a polyvinyl acetal resin, 10 to 500 parts by weight of a phenol resin per 100 parts by weight of epoxy acrylate or hexamethylene diisocyanate As shown in Fig.

The wiring board for a film heater according to the present invention comprises a film substrate and a pair of electrode wiring patterns formed by printing an electrode composition on the upper surface of the film substrate so as to be spaced apart from each other, Powder and carbon nanotube particles, an organic solvent and a dispersing agent, and has a density of 2 g / cm 3 or less.

In the wiring board for a film heater according to the present invention, the electrode wiring pattern has a specific resistance of 30 to 150 x 10 < ^-6 >

The film heater according to the present invention comprises a film substrate, a pair of electrode wiring patterns formed by printing an electrode composition on the upper surface of the film substrate so as to be spaced apart from each other, and a heating composition to be bonded to the pair of electrode wiring patterns Wherein the electrode composition comprises a first mixed binder, silver powder and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant, and has a density of 2 g / cm 3 or less.

In the film heater according to the present invention, the silver powder may include 50 to 80 parts by weight based on 100 parts by weight of the electrode composition.

In the film heater according to the present invention, the exothermic composition may include a second mixed binder, conductive particles, an organic solvent, and a dispersant, and the second mixed binder may have the same composition as the first mixed binder.

The film heater according to the present invention comprises a film substrate, a pair of electrode wiring patterns formed by printing an electrode composition on the upper surface of the film substrate so as to be spaced apart from each other, and a heating composition is printed so as to be bonded to the pair of electrode wiring patterns And a protective film attached to the film substrate so as to cover the electrode wiring pattern and the heating element pattern, wherein the electrode composition comprises a first mixed binder, a silver powder, and a conductive particle including carbon nanotube particles , An organic solvent and a dispersant, and has a density of 2 g / cm 3 or less.

In the film heater according to the present invention, the protective film is formed of at least one material selected from the group consisting of urethane, silicone and imide, and an adhesive layer containing urethane or epoxy is formed on one side of the film and bonded to the film substrate .

The method for producing a film heater according to the present invention includes the steps of: preparing an electrode composition by stirring a first mixed binder, silver powder, and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersing agent; And forming a plurality of heating element patterns by printing a heating composition to be bonded to the pair of electrode wiring patterns, wherein the electrode composition has a density of 2 g / Cm < 3 >.

The film heater according to the present invention is characterized in that an electrode composition comprising a first mixed binder, silver powder and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant is printed on a film substrate to form an electrode wiring pattern, It is robust and can reduce the feeling of rejection when touching human body.

In the film heater according to the present invention, the same mixed binder is applied to produce a heating composition and an electrode composition, thereby forming an electrode wiring pattern and a heating element pattern to optimize the resistance difference between the electrode wiring pattern and the heating element pattern, It is possible to maximize the compatibility between the pattern and the heating element pattern.

Accordingly, the film heater according to the present invention may not cause a change in resistance and exothermic behavior of the two materials even under a repeated stress environment.

Further, since the density of the electrode composition of the film heater according to the present invention is 2 g / cm 3 or less, it is possible to manufacture a large number of electrode wiring patterns in a small amount, and the manufacturing cost can be reduced.

1 is a perspective view showing a film heater according to a first embodiment of the present invention.
2 is a sectional view taken along the line a-a 'in Fig.
3 is a flowchart illustrating a method of manufacturing a film heater according to a first embodiment of the present invention.
4 is a perspective view illustrating a film heater according to a second embodiment of the present invention.
5 is a SEM photograph of a surface of an electrode composition according to Experimental Example of the present invention.
6 is a cross-sectional SEM photograph of an electrode composition according to Experimental Example of the present invention.
7 is an enlarged cross-sectional SEM image of an electrode composition according to Experimental Example of the present invention.
8 to 12 are schematic views showing a method of manufacturing a film heater according to an experimental example of the present invention.
13 is a photograph of a saddle seat heater for an electric vehicle undergoing a heating behavior test using a film heater according to an experimental example of the present invention.
14 is a thermal image of the saddle seat heater according to Fig.

In the following description, only parts necessary for understanding embodiments of the present invention will be described, and descriptions of other parts will be omitted to the extent that they do not disturb the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a film heater according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line a-a 'of FIG.

1 and 2, a film heater 100 according to a first embodiment of the present invention includes a film substrate 20, an electrode wiring pattern 30 and a heating element pattern 40, and a protective film 60 ). ≪ / RTI >

The film substrate 20 is a support on which the electrode wiring pattern 30 and the heating element pattern 40 are formed and has insulation property for suppressing the power applied to the electrode wiring pattern 30 and the heating element pattern 40 from being externally applied, For example, the film substrate 20 may be a film formed of at least one of a urethane-based material and a silicon-based material. The urethane and silicone films are flexible and have a lower heat capacity than the fibers and thus have excellent durability against stress and have a rapid heating time, that is, a time to reach a target temperature in a low temperature environment. Here, the thickness of the film substrate 20 may be 100 탆 or less. By setting the thickness of the film substrate to be equal to or less than 100 mu m, flexibility can be ensured and there is a merit of being light.

The electrode wiring pattern 30 is formed by printing the electrode composition on the upper surface of the film substrate 20. That is, the electrode wiring pattern 30 is formed by printing an electrode composition on the upper surface of the film substrate 20, followed by thermosetting and aging. The electrode wiring patterns 30 may be spaced apart from each other on the film substrate 20 and connected to the electrode terminals 50. Here, the electrode terminal 50 is connected to the (+) pole and the (-) pole power source, respectively, so that the power can be supplied. As the printing method of the electrode composition, screen printing, gravure printing (to roll to roll gravure printing), comma coating (to roll to roll comma coating), flexo, imprinting, offset printing and the like can be used. Curing may be performed at 100 ° C to 180 ° C, and aging may be performed at 250 ° C to 350 ° C.

The electrode composition comprises a first mixed binder, silver powder and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant. Here, the electrode composition may have a density of 2 g / cm 3 or less, and preferably 1.7 to 2 g / cm 3.

The first mixed binder functions to allow the electrode composition to have heat resistance even in a temperature range of about 300 DEG C, and is preferably an epoxy acrylate, hexamethylene diisocyanate, polyvinyl acetal, And a phenol resin (Phenol resin). For example, the first mixed binder may be a mixture of an epoxy acrylate, a polyvinyl acetal, and a phenolic resin, or a mixture of hexamethylene diisocyanate, a polyvinyl acetal and a phenolic resin. For example, the mixing ratio of the first mixed binder may be 10 to 150 parts by weight of the polyvinyl acetal resin and 10 to 500 parts by weight of the phenolic resin based on 100 parts by weight of the epoxy acrylate or hexamethylene diisocyanate. When the content of the phenolic resin is less than 10 parts by weight, the heat resistance of the electrode composition is deteriorated. When the content of the phenolic resin exceeds 500 parts by weight, the flexibility is decreased and the brittleness is increased.

Here, the phenolic resin means a phenolic compound including phenol and phenol derivatives. For example, phenol derivatives include p-cresol, o-Guaiacol, Creosol, Catechol, 3-methoxy-1,2-benzenediol (3- methoxy-1,2-benzenediol, Homocatechol, Vinylguaiacol, Syringol, Iso-eugenol, Methoxyeugenol, o- Cresol, 3-methyl-1,2-benzenediol and (z) -2-methoxy-4- (1-propenyl) -phenol 2-methoxy-4- (1-propenyl) -phenol, 2,6-dimethoxy-4- (2-propenyl) Phenol, 3,4-dimethoxy-Phenol, 4-ethyl-1,3-benzenediol, Resole phenol, 4-methyl-1,2-benzenediol, 1,2,4-benzene triol, 2-methoxy-6-methylphenol 2-Methoxy-6-methylphenol, 2-Methoxy-4-vinylphenol or 4-ethyl-2-methoxy- , Etc. It is not.

The conductive particles may include silver powder and carbon nanotube particles, and may further include graphite particles.

The silver powder may have the form of a flake, a sphere, a polygonal plate, a rod, or the like.

The silver powder may be added in an amount of 50 to 80 parts by weight based on 100 parts by weight of the electrode composition. When the amount is less than 50 parts by weight, the electrical network of the silver powder is not formed and the resistance is high. When the amount is more than 80 parts by weight, the durability against stress is lowered and the cost may increase. Also, by adding 50 to 80 parts by weight of the silver powder, an electrode composition having a density of 2 g / cm 3 or less can be realized, and the electrical conductivity of the electrode wiring pattern to be manufactured can be increased. Here, the tap density of the silver powder may be 2.5 g / cm 3 or less.

The carbon nanotube particles can be selected from single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, or mixtures thereof. For example, the carbon nanotube particles may be multi wall carbon nanotubes. When the carbon nanotube particles are multi-walled carbon nanotubes, the diameter may be 1 nm to 20 nm, and the length may be 1 to 100 mu m.

The graphite particles may have a diameter of 1 탆 to 25 탆 and a thickness of 1 nm to 25 탆.

Here, the carbon nanotube particles are distributed between the silver powder or the graphite particle, thereby bridging the carbon nanotube particles when constructing the electric network, and thereby, a high electric conductivity can be obtained even if a small amount of the silver powder is used. The carbon nanotube particles may be added in an amount of 0.2 to 5 parts by weight based on 100 parts by weight of the electrode composition. The graphite particles may be included in an amount of 0 to 5 parts by weight based on 100 parts by weight of the electrode composition.

The organic solvent is for dispersing the carbon particles, the metal powder and the binder. The organic solvent is selected from the group consisting of Carbitol acetate, Butyl carbotol acetate (BCA), DBE (dibasic ester), Ethyl Carbitol, Ethyl Carbitol (Dipropylene Glycol Methyl Ether (DPM), Cellosolve Acetate, Butyl Cellosolve Acetate, Butanol, and Octanol.

Meanwhile, various methods commonly used may be applied to the dispersion process. For example, ultrasonic treatment (roll-milling), bead milling or ball milling Lt; / RTI >

The dispersing agent is used to make the dispersion more smooth. Examples thereof include conventional dispersants used in the art such as BYK, amphoteric surfactants such as Triton X-100, ionic surfactants such as sodium dodecyl sulfate (SDS) Surfactants can be used.

The heating element pattern 40 may be formed by printing a heating composition so as to be bonded to the pair of electrode wiring patterns 30, respectively. As shown in the drawing, the heating element pattern 40 may be formed in a plurality of rods or in the form of a surface. That is, the heating element pattern 40 may be connected in parallel with the electrode wiring patterns 30 spaced apart by a predetermined distance between the (+) and (-) poles.

The exothermic composition comprises a second mixed binder, carbon particles, a metal powder, an organic solvent and a dispersant. The carbon particles include carbon nanotube particles and graphite particles.

The exothermic composition can be realized in the form of a paint, an ink or a paste by controlling the amount of the organic solvent used.

The exothermic composition preferably contains 8 to 10 parts by weight of the second mixed binder, 0.1 to 5 parts by weight of the carbon nanotube particles, 0.1 to 20 parts by weight of the graphite particles, 10 to 60 parts by weight of the metal powder, 20 to 80 parts by weight of the solvent, and 0.5 to 5 parts by weight of the dispersing agent.

Wherein the exothermic composition comprises 8 to 10 parts by weight of a second mixed binder, 0.1 to 5 parts by weight of carbon nanotube particles, 0.1 to 20 parts by weight of graphite particles, 10 to 60 parts by weight of metal powder, 0.0001 to 1 part by weight of particles, 20 to 80 parts by weight of an organic solvent and 0.5 to 5 parts by weight of a dispersing agent.

In this case, when the metal powder is included in the conductive particles, the heating element pattern formed by the heating composition according to the present invention is characterized in that the metal powder forms the main electrical network and the carbon nanotube particles or the graphite particles are filled in the space between the metal powders. Dimensional random network structure.

The second mixed binder functions to allow the exothermic composition to have heat resistance even in a temperature range of about 300 DEG C, and may include epoxy acrylate, hexamethylene diisocyanate, polyvinyl acetal, And a phenol resin (Phenol resin). That is, the second mixed binder may be a mixture of epoxy acrylate, polyvinyl acetal and phenolic resin, or may be a mixture of hexamethylene diisocyanate, polyvinyl acetal and phenolic resin. In the present invention, by increasing the heat resistance of the second mixed binder, it is possible to suppress the resistance change of the heating element and the breakage of the heating element even when the heating is performed at a high temperature of about 300 캜.

For example, the mixing ratio of the second mixed binder may be 10 to 150 parts by weight of the polyvinyl acetal resin and 10 to 500 parts by weight of the phenolic resin based on 100 parts by weight of the epoxy acrylate or hexamethylene diisocyanate. When the content of the phenolic resin is 10 parts by weight or less, the heat-resistant property of the exothermic composition is deteriorated. When the content of the phenolic resin exceeds 500 parts by weight, the flexibility is lowered and the brittleness is increased.

Carbon nanotube particles and graphite particles impart black body radiation and electrical conductivity.

The carbon nanotube particles can be selected from single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, or mixtures thereof. For example, the carbon nanotube particles may be multi wall carbon nanotubes. When the carbon nanotube particles are multi-walled carbon nanotubes, the diameter may be 1 nm to 20 nm, and the length may be 1 to 100 mu m.

The graphite particles may have a diameter of 1 탆 to 25 탆 and a thickness of 1 nm to 25 탆.

The metal powder is a predominantly electrically conductive material and includes powders of silver or copper. In the case of silver powder, it may have the form of a flake, a circle, a polygonal plate, a rod, or the like. Examples of the copper powder include silver coated Cu, nickel coated Cu powder, and the like.

As described above, the exothermic composition according to the present invention includes carbon particles and a metal powder, thereby enhancing energy efficiency and heat generation rate of the exothermic composition. That is, the metal powder does not have a blackbody radiation function, but a black body radiation function can be realized by including carbon particles in the exothermic composition. The carbon particles can increase the heat resistance of the exothermic composition. And carbon particles can increase the heating rate and energy efficiency.

Graphene oxide particles have insulating properties within 1 to 20 layers and are partially graphitized particles. The graphene oxide particles may be included in an amount of 0.0001 to 1 part by weight based on 100 parts by weight of the exothermic composition.

Graphene oxide particles have various functional groups. Using these various functional groups, the graphene oxide particles can induce chemical covalent bonds directly with the second binder, the organic binder. Accordingly, the exothermic composition according to the present invention has stable heat resistance even at a temperature of around 300 ° C.

The graphene oxide particles have functional groups with excellent chemical reactivity such as carboxyl, amine, imine, hydroxyl, carbonyl, and lactone on the surface and edge. The functional groups contained in graphene oxide particles can be chemically covalently bonded to functional groups contained in diisocyanate, phenol, and epoxy. Thus, graphene oxide particles form chemical covalent bonds with the epoxy acrylate, hexamethylene diisocyanate and phenolic resin contained in the second mixed binder. The chemical covalent bond between the graphene oxide particles and the second mixed binder forms a three-dimensional three-dimensional network and inhibits the movement of the polymer chains, thereby causing an increase in the glass transition temperature and the decomposition initiation temperature.

The organic solvent is for dispersing the carbon particles, the metal powder and the second mixed binder. The organic solvent is selected from the group consisting of Carbitol acetate, Butyl carbotol acetate (BCA), DBE (dibasic ester), ethyl carbitol, ethyl (Dipropylene Glycol Methyl Ether (DPM), Cellosolve Acetate, Butyl Cellosolve Acetate, Butanol, and Octanol.

Meanwhile, various methods commonly used may be applied to the dispersion process. For example, ultrasonic treatment (roll-milling), bead milling or ball milling Lt; / RTI >

The dispersing agent is used to make the dispersion more smooth. Examples thereof include conventional dispersants used in the art such as BYK, amphoteric surfactants such as Triton X-100, ionic surfactants such as sodium dodecyl sulfate (SDS) Surfactants can be used.

The protective film 60 is attached to the film substrate 20 so as to cover the electrode wiring pattern 30 and the heating element pattern 40 to protect the electrode wiring pattern 30 and the heating element pattern 40. [ The protective film 60 may be formed of one of urethane, silicone, and imide materials, and an adhesive layer including a urethane or epoxy material may be formed on the adhesion surface of the protective film 60 with the film substrate 20.

As described above, the film heater 100 according to the present invention includes an electrode composition including a first mixed binder, silver powder, and conductive particles including carbon nanotube particles, an organic solvent, and a dispersant on a film substrate 20 By forming the electrode wiring pattern 30 by printing, it is resistant to stress, and the feeling of rejection upon human contact can be reduced.

The film heater 100 according to the present invention can be manufactured by applying the same mixed binder to the electrode composition and the electrode composition to optimize the resistance difference between the electrode wiring pattern 30 and the heating element pattern 40, And the heating element pattern 40 can be maximized.

Accordingly, the film heater 100 according to the present invention may not cause a change in resistance and exothermic behavior of the two materials even under a repeated stress environment.

In addition, since the density of the electrode composition of the film heater 100 according to the present invention is 2 g / cm 3 or less, it is possible to manufacture a large number of electrode wiring patterns in a small amount, thereby reducing manufacturing cost.

Hereinafter, a method of manufacturing a film heater according to a first embodiment of the present invention will be described.

3 is a flowchart illustrating a method of manufacturing a film heater according to a first embodiment of the present invention.

Referring to FIG. 3, a method of manufacturing a film heater according to the present invention includes the steps of mixing a first mixed binder, a silver powder, and conductive particles including carbon nanotube particles, an organic solvent, and a dispersing agent . The silver powder may be added in an amount of 50 to 80 parts by weight based on 100 parts by weight of the electrode composition. When the amount is less than 50 parts by weight, the electrical network of the silver powder is not formed and the resistance is high. When the amount is more than 80 parts by weight, the durability against stress is lowered and the cost may increase. Also, by adding 50 to 80 parts by weight of the silver powder, an electrode composition having a density of 2 g / cm 3 or less can be realized, and the electrical conductivity of the electrode wiring pattern to be manufactured can be increased. Here, the tap density of the silver powder may be 2.5 g / cm 3 or less. The carbon nanotube particles can be selected from single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, or mixtures thereof. For example, the carbon nanotube particles may be multi wall carbon nanotubes. When the carbon nanotube particles are multi-walled carbon nanotubes, the diameter may be 1 nm to 20 nm, and the length may be 1 to 100 mu m. The graphite particles may have a diameter of 1 탆 to 25 탆 and a thickness of 1 nm to 25 탆. Here, the carbon nanotube particles are distributed between the silver powder or the graphite, thereby bridging the carbon nanotube particles when constructing the electrical network, thereby using a small amount of silver and obtaining high electrical conductivity. Here, the carbon nanotube particles may be included in an amount of 0.2 to 5 parts by weight based on 100 parts by weight of the electrode composition and 0 to 5 parts by weight of the graphite particles.

The electrode composition may have a density of 2 g / cm 3 or less, and preferably 1.7 to 2 g / cm 3. In the step S10, the second mixed binder, carbon particles, metal powder, organic solvent and dispersant are included. The carbon particles may be produced together with a exothermic composition comprising carbon nanotube particles and graphite particles. Wherein the exothermic composition comprises 8 to 10 parts by weight of the second mixed binder, 0.1 to 5 parts by weight of the carbon nanotube particles, 0.1 to 20 parts by weight of the graphite particles, 10 to 60 parts by weight of the metal powder, 20 to 80 parts by weight of an organic solvent, and 0.5 to 5 parts by weight of a dispersant. The exothermic composition preferably contains 8 to 10 parts by weight of the second mixed binder, 0.1 to 5 parts by weight of the carbon nanotube particles, 0.1 to 20 parts by weight of the graphite particles, 10 to 60 parts by weight of the metal powder, 0.0001 to 1 part by weight of the pin oxide particles, 20 to 80 parts by weight of the organic solvent, and 0.5 to 5 parts by weight of the dispersing agent.

Next, in step S20, the electrode composition may be printed on a film substrate to form a pair of electrode wiring patterns. As the printing method of the electrode composition, screen printing, gravure printing (to roll to roll gravure printing), comma coating (to roll to roll comma coating), flexo, imprinting, offset printing and the like can be used. Curing may be performed at 100 ° C to 180 ° C, and aging may be performed at 250 ° C to 350 ° C.

Next, in step S30, a plurality of heating element patterns may be formed by printing the heating composition to be bonded to the pair of electrode wiring patterns.

In step S40, the protective film may be attached to the film substrate so as to cover the heating element pattern and the electrode ending pattern. Here, the protective film may be attached to the protective film through an adhesive layer formed on the contact surface with the film substrate.

Hereinafter, the film heater 200 according to the second embodiment of the present invention will be described. The film heater 200 according to the second embodiment of the present invention has substantially the same structure as the film heater 100 according to the first embodiment of the present invention, except for the structure of the heating element pattern 240. Therefore, the same description will be omitted, and the same constitution will be described with the same reference numerals.

4 is a perspective view illustrating a film heater according to a second embodiment of the present invention.

Referring to FIG. 4, the film heater 200 according to the second embodiment of the present invention may include a heating element pattern 240 having a surface shape in which a pair of electrode patterns 30 are bonded to each other.

That is, the heating element pattern 240 may be formed by applying a heating composition in a planar form such that a pair of electrode patterns 30 are bonded to each other.

Hereinafter, a film heater according to the present invention will be described in detail with reference to experimental examples. The following experimental examples are only illustrative of the present invention, and the present invention is not limited to the following experimental examples.

Experimental Example

The electrode composition was weighed in an amount of 20 wt% of the mixed binder, 8 wt% of the organic solvent and 2 wt% of the dispersant, 70 wt% of the silver powder as the conductive particles and 3 wt% of the carbon nanotube particles, Stirring, and agitated composition was stirred using a 3 roll mill until homogeneous.

6 is a cross-sectional SEM photograph of an electrode wiring pattern according to an experimental example of the present invention. FIG. 7 is a cross-sectional SEM image of an electrode wiring pattern according to an experimental example of the present invention. An enlarged cross-sectional SEM of the wiring pattern.

5 to 7, an electrode composition according to an experimental example of the present invention was manufactured using a silver powder having a tap density of 2.5 g / cm 3 or less and a wide cross-section, and in order to minimize resistance change due to elongation It can be seen that carbon nanotubes are present between silver powders. As a result of measuring the density of the electrode composition according to the experimental example of the present invention using the Archimedes method, it was confirmed that the density was about 1.8 g / cm 3.

The exothermic composition was prepared by adding CNT and Graphite particles to a solvent of carbitol acetates and adding a dispersant to prepare a CNT / Graphite dispersion (Solution A) by ultrasonication for 60 minutes. Epoxy acrylate, phenol resin and polyvinyl acetal resin And a master batch (M / B) was prepared by mechanical stirring or mechanical kneading capable of rotating motion by adding a carbitol acetate solvent, followed by kneading Solution A and M / B through mechanical stirring And then completely kneaded using a 3-roll mill.

8 to 12 are schematic views showing a method of manufacturing a film heater according to an experimental example of the present invention.

8 to 12, an electrode composition prepared on a film substrate 20 using a urethane material was screen printed using a 250 mesh screen mask in accordance with the electrode wiring pattern 30, and then heat-treated at 150 ° C for 30 minutes . Thereafter, the exothermic composition was screen-printed in the same manner as the exothermic pattern 40, and then heat-treated at 150 DEG C for 30 minutes. Then, the protective film 60 with an adhesive layer was hot-pressed, and after the hot-pressing, the film heater 100 according to the experimental example of the present invention was manufactured by wiring to the connection terminal 50.

The film heater manufactured here was analyzed for thermal image, exothermic behavior and electrical characteristics by using a thermal camera.

FIG. 13 is a photograph of a saddle seat heater for an electric vehicle undergoing a heat generation behavior test using a film heater according to an experimental example of the present invention, and FIG. 14 is a thermal image of the saddle seat heater according to FIG.

13 and 14, a heat generating composition is printed and cured in a specific size to form a heating element pattern, an electrode composition is printed on both sides and cured, a sample for heating test is prepared, The temperature uniformity of each heating element pattern was measured by using an IR thermometer and the temperature stability and the resistance change of the heating element were measured according to the operating time. As a result, it was confirmed that the temperature was uniformly distributed in the heating element pattern.

On the other hand, Table 1 shows the characteristics of the electrode composition according to the experimental example of the present invention and the characteristic change according to the silver powder content.

For the bending test, a separate specimen was manufactured and tested. The bending angle was 90 degrees and the radius of curvature was 1 mm. The resistance change and fracture before and after the repeated test were evaluated.

The resistivity evaluation was performed by measuring the resistivity of the composition by screen printing at a size of 10 x 10 cm and curing, specifying the line resistance at both ends, and measuring the thickness of the printed electrode through SEM measurement (R = rx (L / S)) .

Morphology was also analyzed by SEM photograph of the electrode wiring pattern printed using the composition.

Furtherance (% By weight) of the powder Density (g / cm3) Bending radius 1mm / resistance change rate after 100,000 bending test (%) Resistivity
(x10 ^{- 6} Ω㎝) Adhesive Strength (ASTM D3359) Composition A (Example) 70 1.8 ± 1.2% 60 5B Composition B 65 1.76 ± 1% 88 5B Composition C 60 1.72 ± 1% 150 5B Composition D 75 1.85 ± 2% 40 5B Composition E 80 1.91 ± 3% 32 5B Composition F 85 1.96 ± 5% 10 5B

Referring to Table 1, the electrode wiring pattern made of the electrode composition according to the experimental example of the present invention has a bending radius of 90 degrees, a radius of curvature of 1 mm or less, a rate of change of the resistance of both ends of the electrode after about 100,000 cycling bending tests, 1%. It can be seen that the content of silver powder directly affects the density of the electrode composition and greatly affects the rate of change in resistance.

Thus, the film heater according to the experimental example of the present invention can be manufactured by printing an electrode composition including a first mixed binder, silver powder, and conductive particles including carbon nanotube particles, an organic solvent and a dispersant on a film substrate, So that it is resistant to stress and can reduce the feeling of rejection in human body contact.

In addition, the film heater according to the experimental example of the present invention is manufactured by applying the same mixed binder to the electrode assembly and the electrode composition, thereby forming the electrode wiring pattern and the heating element pattern to optimize the resistance difference between the electrode wiring pattern and the heating element pattern , It is possible to maximize the compatibility between the electrode wiring pattern and the heating element pattern.

Accordingly, the film heater according to the experimental example of the present invention may not cause a change in resistance and exothermic behavior of the two materials even under a repeated stress environment.

Further, since the density of the electrode composition of the film heater according to the present invention is 2 g / cm 3 or less, it is possible to manufacture a large number of electrode wiring patterns in a small amount, and the manufacturing cost can be reduced.

20: film substrate 30: electrode wiring pattern
40, 240: heating element pattern 50: electrode terminal
60: protective film 100, 200: film heater

Claims (15)

A first mixed binder;
Conductive particles comprising silver powder and carbon nanotube particles having a tap density of 2.5 g / cm 3 or less;
Organic solvent; And
Dispersing agent; Lt; / RTI >
Wherein the silver powder comprises 51 to 80 parts by weight based on 100 parts by weight of the electrode composition,
And the density is 2 g / cm < 3 > or less. delete delete The method according to claim 1,
Wherein the carbon nanotube particles comprise 0.2 to 5 parts by weight based on 100 parts by weight of the electrode composition. 5. The method of claim 4,
Wherein the conductive particles further comprise graphite particles,
Wherein the graphite particles are 0.1 to 5 parts by weight based on 100 parts by weight of the electrode composition. 6. The method of claim 5,
Wherein the carbon nanotube particles are distributed among the silver powder or the graphite particles to form an electrical network. The method according to claim 1,
Wherein the first mixed binder comprises 10 to 150 parts by weight of a polyvinyl acetal resin and 10 to 500 parts by weight of a phenolic resin based on 100 parts by weight of epoxy acrylate or hexamethylene diisocyanate. Film substrate;
A pair of electrode wiring patterns formed by printing an electrode composition on the upper surface of the film substrate so as to be spaced apart from each other; / RTI >
The electrode composition comprises a first mixed binder, a silver powder having a tap density of 2.5 g / cm 3 or less, and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant, wherein the density is 2 g /
Wherein the silver powder comprises 51 to 80 parts by weight based on 100 parts by weight of the electrode composition. 9. The method of claim 8,
Wherein the electrode wiring pattern has a specific resistance of 30 to 150 占^10-6 ? Cm. Film substrate;
A pair of electrode wiring patterns formed by printing an electrode composition on the upper surface of the film substrate so as to be spaced apart from each other; And
A plurality of heating element patterns formed by printing a heating composition to be bonded to the pair of electrode wiring patterns; / RTI >
The electrode composition comprises a first mixed binder, a silver powder having a tap density of 2.5 g / cm 3 or less, and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant, wherein the density is 2 g /
Wherein the silver powder comprises 51 to 80 parts by weight based on 100 parts by weight of the electrode composition. delete 11. The method of claim 10,
Wherein the exothermic composition comprises a second mixed binder, conductive particles, an organic solvent and a dispersant,
Wherein the second mixed binder has the same composition as the first mixed binder. Film substrate;
A pair of electrode wiring patterns formed by printing an electrode composition on the upper surface of the film substrate so as to be spaced apart from each other;
A plurality of heating element patterns formed by printing a heating composition to be bonded to the pair of electrode wiring patterns; And
A protective film attached to the film substrate so as to cover the electrode wiring pattern and the heating element pattern; / RTI >
The electrode composition comprises a first mixed binder, a silver powder having a tap density of 2.5 g / cm 3 or less, and conductive particles comprising carbon nanotube particles, an organic solvent and a dispersant, wherein the density is 2 g /
Wherein the silver powder comprises 51 to 80 parts by weight based on 100 parts by weight of the electrode composition. 14. The method of claim 13,
Wherein the protective film is formed of at least one material selected from the group consisting of urethane, silicone and imide, and an adhesive layer including a urethane or epoxy adhesive is formed on one surface of the protective film and adhered to the film substrate. Mixing a first mixed binder, a silver powder having a tap density of 2.5 g / cm 3 or less, and conductive particles comprising carbon nanotube particles, an organic solvent, and a dispersant to prepare an electrode composition;
Printing the electrode composition on a film substrate to form a pair of electrode wiring patterns; And
Forming a plurality of heating element patterns by printing a heating composition to be bonded to the pair of electrode wiring patterns; Lt; / RTI >
The electrode composition has a density of 2 g / cm 3 or less,
Wherein the silver powder comprises 51 to 80 parts by weight based on 100 parts by weight of the electrode composition.

Images