KR20110138939A - Conducting solution and conducting laminates - Google Patents

Abstract

PURPOSE: A conductive dispersion and a conductive laminate are provided to form a coating layer with conductivity and transparency, and to offer the excellent dispersion stability of the dispersion to the laminate. CONSTITUTION: A conductive dispersion contains the following: carbon nanotubes; a compound selected from paraffin-based hydrocarbon marked with chemical formula 1: C_nH_(2n+2) or chemical formula 2: RCOOR`, its isomer, or an ester compound; and a solvent. In the chemical formula 1, n is an integer greater than 20. In the chemical formula 2, R is C_lH_(2l+1) and R` is C_mH_(2m+1).

Description

Conducting solution and conducting laminates

The present invention relates to a conductive dispersion and a conductive laminate, and to a conductive dispersion that can be used to form a conductive film, such as a transparent electrode, an EMI shielding film, and an ESD filter, and a use thereof.

Carbon nanotubes have an electrical resistivity of 10 ^-4 Ωcm, comparable to that of metals, and are more than 1000 times higher in surface area than bulk materials. Recently, carbon nanotubes have been actively researched in their manufacturing, applications, and applications. . In particular, carbon nanotubes have properties of electrical conductors, such as metals, that are difficult to conduct electricity, depending on their shape and size, and are very stable not only in various electronic circuit fields but also chemically and mechanically. The fields of application are very diverse.

Such carbon nanotubes are commercially available and supplied by numerous manufacturers. Corresponding manufacturing processes are familiar to those skilled in the art. Thus, for example, carbon nanotubes can be produced by arc ablation between carbon electrodes, for example by laser ablation starting from graphite, or by catalytic decomposition of hydrocarbons (chemical vapor deposition).

To expand the scope of use of carbon nanotubes, there is a need for carbon nanotubes that are provided in an easily manageable form, preferably in the form of dispersions.

Since carbon nanotubes have a very high aspect ratio and are present in a very agglomerated form and / or in the form of a coil, it is very difficult to convert them into stable dispersions.

Accordingly, there have been enough attempts to stably disperse carbon nanotubes in the related art. However, conventionally known methods were not suitable for preparing stable and concentrated dispersions of carbon nanotubes, and most of them were unable to obtain dispersions having storage stability, and the concentration of carbon nanotubes is extremely low.

As an example of the prior art for producing a dispersion of carbon nanotubes, there is a method of modifying the surface of the carbon nanotubes for the purpose of making surface polarity in order to promote subsequent dispersion. Suitable methods of modifying carbon nanotubes include, for example, oxidation processes, in particular chemical pretreatment, halogenation or other polarization processes to modify the surface of the carbon nanotubes.

This method is expensive and inconvenient for pretreatment, especially when implemented on an industrial scale.

Another conventional technique involves the conversion of carbon nanotubes into an aqueous dispersion in the presence of a water soluble polymer material. However, these methods have the inconvenience that they are not universally available on the one hand but are limited to aqueous dispersions on the other hand, on the other hand they can only obtain dispersions with relatively low carbon nanotube content.

Conventional techniques usually come with low concentrations or contents of carbon nanotubes. Often results in heterogeneous dispersions of carbon nanotubes that lack long term storage stability.

Meanwhile, as computers, various home appliances, and communication devices are digitized and rapidly becoming high-performance, there is an urgent demand for the implementation of large screens and portable displays. To realize a large, portable display that is portable, a display material made of a material that can be folded or rolled like a newspaper is required.

To this end, the display electrode material should not only exhibit a transparent and low resistance value, but also have a high strength to be mechanically stable even when the device is bent or folded, and has a coefficient of thermal expansion similar to that of a plastic substrate, resulting in overheating or Even at high temperatures, there should be no short-circuit or large change in sheet resistance.

Flexible displays enable the manufacture of displays of any shape, so they can be used not only for portable display devices, but also for clothing, which can change colors and patterns, clothing labels, billboards, price signs on product shelves, large electric lighting devices, etc. Can be.

In this regard, transparent conductive thin films have been widely used in devices that require both the transmission and conductivity of light, such as image sensors, solar cells, and various displays (PDP, LCD, flexible). Material.

Generally, indium tin oxide (ITO) has been studied as a transparent electrode for flexible displays, but in order to manufacture a thin film of ITO, a vacuum process is required, which requires expensive processing costs and a flexible display device. When bent or folded, the service life is shortened due to breakage of the thin film.

In order to solve the above problems, the carbon nanotubes are chemically bonded to the polymer and then molded into a film, or the carbon nanotubes are coated on the conductive polymer layer by coating the purified carbon nanotubes or the carbon nanotubes chemically bonded to the polymer. Nanoscale is dispersed inside or on the coating layer, and metal nanoparticles such as gold and silver are mixed to minimize scattering of light in the visible region and improve conductivity, so that the transmittance in the visible region is 80% or more, and sheet resistance The transparent electrode of less than 100 Ω / sq has been developed (Korean Patent Publication No. 10-2005-001589). In this case, specifically, a solution of carbon nanotubes dispersed with polyethylene terephthalate was prepared to prepare a carbon nanotube polymer copolymer solution having a high concentration, and then coated on a polyester film substrate and dried to prepare a transparent electrode.

However, when the transparent electrode is used at a high temperature, polymer deformation may occur and it is difficult to form a pattern of the electrode.

In addition, research into using a conductive polymer which is an organic material as a transparent electrode material is underway. In the case of an electrode manufactured using a conductive polymer, various existing polymer coating methods can be used, which greatly reduces the process cost and operation. That is, in manufacturing flexible displays and electric lighting devices, transparent electrodes made of conductive polymers such as polyacetylene, polypyrrole, polyaniline, polythiophene, etc. are much more flexible and brittle as well as process advantages over transparent indium tin oxide electrodes. This has the advantage that the life of the device can be extended in cases where less flexible electrodes are needed, especially in the manufacture of touch screens and the like. However, in general, the conductive properties of organic electrodes made of a conductive polymer increase in proportion to the thickness of the electrode. Since the conductive polymer absorbs light in the visible region, a thin coating can be used to increase the transmittance for display purposes. In this case, when the transmittance of the visible light region is increased, it is difficult to satisfy the sheet resistance required in the application field of the transparent electrode. In particular, in the case of using polythiophene (byteron P, Bayer Co., Ltd.) in which conductive polymer nanoparticles are dispersed in order to improve processability, even when using a mixed solvent to improve conductivity and coating property, the substrate is 50 nm thick. In the case of spin coating on the substrate, it is difficult to obtain a sheet resistance of 1 kΩ / sq or less.

In addition, most conventional organic electrode materials using carbon nanotubes are prepared by simply mixing carbon nanotubes and conductive polymers, and carbon nanotubes are formed in the conductive polymer matrix by a strong van der Waals force. Agglomerates heavily at Due to the agglomeration of the carbon nanotubes, it is difficult to form a uniformly dispersed electrode in spite of the excellent conductive properties of the carbon nanotubes.

In one embodiment of the present invention to form a coating layer having conductivity and transparency, to provide a conductive dispersion composition excellent in dispersion stability.

In one embodiment of the present invention also to provide a laminate comprising a carbon nanotube conductive film excellent in electrical conductivity and adhesion to the object.

In one embodiment of the present invention; At least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof represented by the following Chemical Formulas 1 to 2; And it provides a conductive dispersion containing a solvent.

Formula 1

C _n H _{2n + 2}

Wherein n is an integer of 20 or more.

Formula 2

RCOOR '

_Wherein R is C _l H _{2l + 1 ,} R 'is C _m H _{2m + 1} , l and m are each an integer and the sum thereof (l + m) is an integer of 20 or greater.

In addition, in the conductive dispersion of the present invention, the paraffinic hydrocarbon or its isomer or ester compound is not limited to a specific number of carbon atoms in Chemical Formulas 1 to 2, but n is 20 or more, or the number of l + m is 20 or more. It may be desirable in terms of satisfactory heat resistance and surface properties.

In the application of the conductive dispersion of the present invention to a heat resistant film, preferably, at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof has a boiling point of at least 300 ° C.

In terms of dispersibility of the carbon nanotubes in the conductive dispersion of the present invention, the carbon nanotubes may have a content of 0.01 to 2% by weight.

In the conductive dispersion of the present invention, preferably in terms of dispersibility and expression of adhesion to the object, paraffinic hydrocarbons, isomers and ester compounds thereof may be included in an amount of 10 to 5,000 parts by weight based on 100 parts by weight of carbon nanotubes. .

These conductive dispersions are Naphtha, Solvent Naphtha, Carbon Tetrachloride, Benzene, Chloroform, Dichloromethane, Dichloromethane as solvents in terms of solubility and dispersibility. (Dichloroethane), Ligroin, Petroleum Ether, Ether, Pentane, Hexane, Heptane, Octane, Isodecane, Purity 95 At least one of at least one selected from alcohols, acetone and ethyl acetate is preferred.

Another embodiment of the present invention provides a conductive laminate including a carbon nanotube and a conductive film comprising at least one compound selected from paraffinic hydrocarbons represented by the following Chemical Formulas 1 to 2, isomers and ester compounds thereof. .

Formula 1

C _n H _{2n + 2}

Wherein n is an integer of 20 or more.

Formula 2

RCOOR '

_Wherein R is C _l H _{2l + 1 ,} R 'is C _m H _{2m + 1} , l and m are each an integer and the sum thereof (l + m) is an integer of 20 or greater.

In consideration of heat resistance in the conductive laminate according to one embodiment of the present invention, at least one compound selected from paraffinic paraffinic hydrocarbons, isomers and ester compounds thereof may have a boiling point of at least 300 ° C.

When considering the electrical conductivity and dispersibility in the conductive laminate according to an embodiment of the present invention, the carbon nanotubes may be included in 10 to 95% by weight of the conductive film.

In the conductive laminate according to one embodiment of the present invention, at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds in consideration of adhesion to a substrate and dispersibility of carbon nanotubes is 100 wt% of carbon nanotubes. It may be included in 10 to 5,000 parts by weight relative to the part.

In the conductive laminate according to one embodiment of the present invention, the conductive film may have a thickness of 10nm to 25 μm.

The conductive laminate according to one embodiment of the present invention may include a substrate selected from a plastic film and a glass substrate, wherein the plastic film is selected from a polyester film, a polyimide film, and a polycarbonate film. Can be.

The conductive laminate according to the embodiment of the present invention may be a transparent electrode.

The conductive laminate according to one embodiment of the present invention may be for electromagnetic shielding.

The conductive laminate according to one embodiment of the present invention may be electrostatic discharge (ESD).

According to one embodiment of the present invention, it is possible to provide a dispersion which may include carbon nanotubes with excellent storage stability and high content, and also by forming a conductive film which further improves electrical conductivity and adhesion to an object. By improving the electrical conductivity and surface adhesion, it is possible to provide a conductive laminate that can increase product efficiency and improve surface properties.

Hereinafter, the present invention will be described in detail.

The conductive dispersion according to one embodiment of the present invention includes at least one compound selected from carbon nanotubes, paraffinic hydrocarbons represented by the following Chemical Formulas 1 to 2, isomers and ester compounds thereof.

Formula 1

C _n H _{2n + 2}

Wherein n is an integer of 20 or more.

For example, it may be a component as shown in Table 1 below, but is not limited to normal paraffin.

CARBON NAME FORMULA Melting point Boiling point CAS RN C (20) n-Eicosane C20H42 (282.55) 37 C 343 C 112-95-8 C (21) n-Henicosane C21H44 (296.58) 40.5 C 356.5 C 629-94-7 C (22) n-Docosane C22H46 (310.61) 44.5 C 368.5 C 629-97-0 C (23) n-Tricosane C23H48 (324.63) 47.5 C 380 C 638-67-5 C (24) n-Tetracosane C24H50 (338.66) 52 C 391 C 646-31-1 C (25) n-Pentacosane C25H52 (352.69) 54 C 402 C 629-99-2 C (26) n-Hexacosane C26H54 (366.71) 56.5 C 412 C 630-01-3 C (27) n-Heptacosane C27H56 (380.74) 59 C 593-49-7 C (28) n-Octacosane C28H58 (394.77) 64.5 C 431.5 C 630-02-4 C (29) n-Nonacosane C29H60 (408.79) 65 C 630-03-5 C (30) n-Triacontane C30H62 (422.82) 66 C 450 C 638-68-6 C (31) n-Hentriacontane C31H64 (436.85) 67 C 630-04-6 C (32) n-Dotriacontane C32H66 (450.87) 69 C 467 C 544-85-4 C (33) n-Triatriacontane C33H68 (464.90) 71 C 630-05-7 C (34) n-Tetratriacontane C34H70 (478.93) 72 C 14167-59-0 C (35) n-Pentatriacontane C35H72 (492.95) 73 C 630-07-9 C (36) n-Hexatriacontane C36H74 (506.98) 74 C 630-06-8 C (37) n-Heptatriacontane C37H76 (521.01) 76 C 7194-84-5 C (38) n-Octatriacontane C38H78 (535.03) 78 C 7194-85-6 C (39) n-Nonatriacontane C39H80 (549.05) 80 C 7194-86-7 C (40) n-Tetracontane C40H82 (563.09) 82 C 4181-95-7 C (42) n-Dotetracontane C42H86 (591.13) 84 C 7098-20-6 C (44) n-Tetratetracontane C44H90 (619.20) 85 C 7098-22-8 C (46) n-Hexatetracontane C46H94 (647.24) 86 C 7098-24-0 C (48) n-Octatetracontane C48H98 (675.30) 90 C 7098-26-2 C (50) n-Pentacontane C50H102 (703.36) 91 C 6596-40-3 C (52) n-Dopentacontane C52H106 (731.40) 92 C 7719-79-1 C (54) n-Tetrapentacontane C54H110 (759.45) 93 C 5856-66-6 C (56) n-Hexapentacontane C56H114 (787.50) 94 C 7719-82-6 C (58) n-Octapentacontane C58H118 (815.56) 95 C 7667-78-9 C (60) n-Hexacontane C60H122 (843.62) 96 C 7667-80-3 C (70) n-Heptacontane C70H142 105.5 C

Formula 2

RCOOR '

_Wherein R is C _l H _{2l + 1 ,} R 'is C _m H _{2m + 1} , l and m are each an integer and the sum thereof (l + m) is an integer of 20 or greater.

For example, l may be Hexadecyl Palmitate, wherein l is 15 and m is 16, as shown in the following structural formula.

용융점 53℃, 비점 534℃

Melting Point 53 ℃, Boiling Point 534 ℃

In addition, l may be 21, and m may be methyl behenate (Methyl Behenate) as shown in the following structural formula.

용융점 55℃, 비점 393℃

Melting Point 55 ℃, Boiling Point 393 ℃

Although the above two compounds have been exemplified, the compound of Formula 2 presented in the present invention is not limited thereto.

A carbon nanotube is an allotrope of carbon, which means that a plurality of carbon atoms combine to form a tube. Carbon nanotubes in the present invention include carbon nanotubes of the kind which can be prepared by a process known or available as a commercial product. Examples thereof include single-walled carbon nanotubes (SWCNT or SWNT), multi-walled carbon nanotubes (MWCNT or MWNT), carbon nanofibers, and the like. Single-layer carbon nanotubes are one layer of graphite carbon atoms, and multilayer carbon nanotubes are two or more layers of graphite carbon atoms concentrically stacked.

The carbon nanotubes may also have any diameter (ie, outer diameter). The carbon nanotubes have a diameter of at least 1 nm to 35 nm, preferably 1 to 5 nm, in terms of achieving excellent conductivity and high light transmittance.

In general, the electrical resistance of carbon nanotubes itself is 10 ^-4 Ωcm and has a high electrical conductivity comparable to that of metals, but when used as a carbon nanotube electrode, it is known to have a lower electrical conductivity. This is due to poor dispersion characteristics.

In this regard, the conductive dispersion of the present invention includes a paraffinic hydrocarbon represented by Chemical Formulas 1 to 2 or an isomer or ester compound thereof that can function as a dispersant and also function as a binder at the time of film formation.

The paraffinic hydrocarbon represented by Formula 1 or an isomer or ester compound thereof has been generally applied as a lubricant or a releasing agent, and when it is included in the conductive dispersion of the present invention, it functions to disperse the carbon nanotubes while the film is formed. While expressing adhesion to the surface, the surface has a releasability to be able to perform a function of improving friction characteristics without sticking when contacted with the outside.

The paraffinic hydrocarbon or the isomer thereof represented by Chemical Formula 1 may have n at least 20 to maintain a stable solid state.

In the ester compound of the paraffinic hydrocarbon represented by Formula 2, l + m should be at least 20 to maintain a stable solid state.

In this case, the boiling point may be maintained at 300 ° C. or higher, thereby forming a heat resistant conductive film.

In the conductive dispersion according to an embodiment of the present invention, the carbon nanotubes may have a content of 0.01 to 2% by weight, preferably 0.1 to 1% by weight, more preferably 0.1 to 0.5% by weight. The carbon nanotubes may be included in the content because the dispersibility is improved due to at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds. If the content of the carbon nanotubes is more than 2% by weight, the carbon nanotubes may not be sufficiently dispersed and the dispersibility may be reduced, and if the carbon nanotubes are less than 0.01% by weight, the manufacturing process is unnecessary to obtain the desired electric conductivity. Can increase.

On the other hand, the paraffinic hydrocarbon or its isomer or ester compound may be contained in an amount of 10 to 5000 parts by weight based on 100 parts by weight of carbon nanotubes to sufficiently disperse the carbon nanotubes, and a conductive film containing carbon nanotubes may sufficiently adhere and be fixed to the substrate. It is advantageous in terms of being able. Preferably, the paraffinic hydrocarbon or its isomer or ester compound may be included in an amount of 20 to 1000 parts by weight, most preferably 50 to 500 parts by weight, based on 100 parts by weight of carbon nanotubes.

The conductive dispersion of the present invention includes a solvent capable of dispersing carbon nanotubes while dissolving such a paraffinic hydrocarbon or an isomer or ester compound thereof. Examples of the solvent include naphtha, solvent naphtha, and solvent naphtha. Carbon Tetrachloride, Benzene, Chloroform, Dichloromethane, Dichloroethane, Ligroin, Petroleum Ether, Ether, Pentane (Ether) Pentane, Hexane, Heptane, Octane, Isodecane, at least one selected from alcohols with a purity of 95% or higher, acetone and ethyl acetate It may be preferable in view of excellent solubility in at least one compound selected from hydrocarbons, isomers and ester compounds thereof. All.

In the present invention, the term "solvent" is to be understood as a liquid component which disperses or dissolves another substance (for example, at least one compound selected from carbon nanotubes and happaraffinic hydrocarbons, isomers and ester compounds thereof). will be.

The conductive dispersion of the present invention may further include a sunscreen, an antioxidant, and the like as necessary, as long as the conductivity is not impaired without inhibiting dispersion stability.

In consideration of the dispersibility, the carbon nanotubes are dispersed with at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds on an organic solvent, and then dispersed by sonication. Can be obtained. The method of dispersing the carbon nanotubes is not particularly limited, and examples thereof include ultrasonic dispersion, tri-roll dispersion, homogenizer or physical dispersion of Kneader, Mill-Blender, Ball Mill, etc. For example, the method of using additives, such as a dispersing agent and an emulsifier, etc. are mentioned.

The resulting conductive dispersion has a homogeneous dispersion which is stable for a long time.

This homogeneous dispersion can be determined by measuring the degree of aggregation and the amount of dispersion, for example, by checking the particle size measurement of carbon nanotubes or observing precipitation by reaggregation.

Long-term stability can be seen, for example, by being stable for about three months when the dispersion is left at room temperature and showing no precipitation of carbon nanotubes.

Such a conductive dispersion of the present invention can be applied onto a substrate and dried to form a conductive film. The conductive film is preferably transparent.

The carbon nanotube-dispersed conductive film may be formed by spray coating, spin coating, casting of a doctor blade, or the like, but is not limited thereto.

The conductive film formed satisfies the appropriate conductivity. The conductivity of the conductive film can be generally expressed by surface resistivity (Ω / □ or Ω / sq.). When the conductive dispersion is formed to have a thickness of 300 nm on the polyethylene terephthalate film, the surface resistivity may be at least about 10 ² to 10 ⁶ Ω / □, preferably about 10 ² to 10 ⁴ Ω / □.

In addition, the formed conductive film is excellent in adhesion to the substrate.

Adhesiveness can be evaluated by the surface resistance value change rate of the conductive film after the adhesion and peel test through the 3M Scotch tape, and the surface resistance change rate based on 10 times the adhesion and peeling test may be about 10% or less.

In addition, the formed conductive film has a property of not adhering upon contact with the outside, and this property is called releasability. This prevents damage to the membrane when in contact with the hand when positioned on the outermost surface.

In addition, the formed conductive film is capable of satisfying the heat resistance characteristics, and the heat resistance characteristics can be confirmed by a method of evaluating a change in surface resistance after heat treatment at 300 ° C. for 1 hour.

Another embodiment of the present invention provides a conductive laminate including such a conductive film.

The carbon nanotube content in the conductive film is 10 to 95% by weight, preferably 50 to 95% by weight, and more preferably 70 to 95% by weight, in consideration of the point for achieving sufficient conductivity.

In addition, at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof in consideration of adhesion to the substrate and dispersibility of carbon nanotubes is 10 to 5,000 parts by weight, preferably 100 parts by weight of carbon nanotubes. 20 to 1,000 parts by weight, most preferably 50 to 500 parts by weight.

In the conductive laminate according to one embodiment of the present invention, the conductive film has a thickness of 10nm to 5㎛ forms a good electrode pattern and the side to suppress the deterioration of optical properties such as good conductivity of the conductive film and transmittance of the display It may be advantageous in that respect. If the thickness of the conductive film is thinner than 10 nm, the surface resistance of the conductive film is increased, the conductivity is lowered, and the conductive film is vulnerable to an alkaline solution, which may make it difficult to form a circuit. On the other hand, when the thickness is larger than 5 μm, light transmittance may be reduced, which may be inappropriate for use in a display device.

Such a conductive film may be formed on a substrate, wherein the substrate may be selected from a plastic film and a glass substrate. In this case, the plastic film may be selected from a polyester film, a polyimide film, and a polycarbonate film.

For example, the substrate forming the film-shaped transparent electrode is not particularly limited as long as the film satisfies heat resistance and transparency, and is measured in a range of 50 to 250 ° C. by thermomechanical analysis based on a film thickness of 50 to 100 μm. The polyimide film may have an average linear expansion coefficient (CTE) of 35.0 ppm / ° C or less and a yellowness of 15 or less.

If the average coefficient of linear expansion (CTE) is greater than 35.0 ppm / ° C based on a film thickness of 50 to 100 μm, the difference in thermal expansion coefficient with the plastic substrate is increased, and a short circuit may occur when the device is overheated or at a high temperature. In addition, a yellowness of greater than 15 is not preferred as a transparent electrode because of the lack of transparency. In this case, the average linear expansion coefficient is obtained by measuring a strain according to a temperature rise within a predetermined temperature range, which may be measured using a thermomechanical analyzer.

In addition, in terms of permeability, a colorless and transparent plastic film, specifically, a polyimide film having a yellowness of 15 or less based on a film thickness of 50 to 100 μm may be preferable. In addition, a polyimide film having an average transmittance of 85% or more at 380 to 780 nm may be used as a plastic film when the transmittance is measured with a UV spectrophotometer based on a film thickness of 50 to 100 μm. When such a transparency is satisfied, it can be used as a plastic substrate for a transmissive electronic paper and a liquid crystal display device. Furthermore, the plastic film may be a polyimide film having a transmittance of 88% or more at 550 nm and a transmittance of 70% or more at 420 nm when the transmittance is measured by a UV spectrophotometer based on a film thickness of 50 to 100 μm.

In addition, in terms of improving transparency by increasing transparency, the polyimide film has an L value of 90 or more, a value of 5 or less, and b value of 5 when color coordinates are measured with a UV spectrophotometer based on a film thickness of 50 to 100 μm. It may be the following polyimide film.

Such a polyimide film may be obtained by polymerizing an aromatic dianhydride and a diamine to obtain a polyamic acid, and then imidating it. Examples of the aromatic dianhydride include 2,2-bis (3,4-dicarboxy). Phenyl) hexafluoropropane dianhydride (6-FDA), 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dica At least one selected from carboxyl anhydride (TDA) and 4,4 ′-(4,4′-isopropylidenediphenoxy) bis (phthalic anhydride) (HBDA) and pyromellitic dian One or more selected from hydride (PMDA), biphenyltetracarboxylic dianhydride (BPDA) and oxydiphthalic dianhydride (ODPA), but is not limited thereto.

Examples of aromatic diamines include 2,2-bis [4- (4-aminophenoxy) -phenyl] propane (6HMDA), 2,2'-bis (trifluoromethyl) -4,4'-diamino Biphenyl (2,2'-TFDB), 3,3'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (3,3'-TFDB), 4,4'-bis ( 3-aminophenoxy) diphenylsulfone (DBSDA), bis (3-aminophenyl) sulfone (3DDS), bis (4-aminophenyl) sulfone (4DDS), 1,3-bis (3-aminophenoxy) benzene (APB-133), 1,4-bis (4-aminophenoxy) benzene (APB-134), 2,2'-bis [3 (3-aminophenoxy) phenyl] hexafluoropropane (3-BDAF ), 2,2'-bis [4 (4-aminophenoxy) phenyl] hexafluoropropane (4-BDAF), 2,2'-bis (3-aminophenyl) hexafluoropropane (3,3 ' -6F), 2,2'-bis (4-aminophenyl) hexafluoropropane (4,4'-6F) and oxydianiline (ODA) may be, but are not limited thereto. .

There is no particular limitation in the method for producing a polyimide film using such a monomer, and as one example thereof, the aromatic diamine and the aromatic dianhydride are polymerized under a first solvent to obtain a polyamic acid solution. After imidizing the mixed acid solution, the imidized solution was added to the second solvent, filtered and dried to obtain a solid content of the polyimide resin, and a polyimide solution obtained by dissolving the obtained polyimide resin solid content in the first solvent was formed into a film. It can form into a film through a process. In this case, the second solvent may be lower in polarity than the first solvent, and specifically, the first solvent may be m-crosol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), or dimethylacetate. At least one selected from amide (DMAc), dimethyl sulfoxide (DMSO), acetone, and diethyl acetate, and the second solvent may be at least one selected from water, alcohols, ethers, and ketones.

Meanwhile, in order to form a conductive resin film having a uniform thickness in forming a metal film on the plastic film, the surface smoothness Ra of the plastic film may be 2 μm or less, preferably 0.001 to 0.04 μm.

Such a conductive film of the present invention is excellent in adhesion and adhesion to the substrate, excellent mechanical strength of the electrode, and good pattern implementation when forming the electrode pattern. Moreover, even thin films can exhibit excellent high conductivity, and as a result, light transmittance can also provide excellent conductive films.

Such a conductive laminate can also be used as a transparent electrode.

In addition, the conductive laminate may be used as an electromagnetic shield, and may also be used as an electrostatic discharge (ESD) filter.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

<Production of Polyimide Substrate Film>

Preparation Example 1

First, the precursor solution for forming the polyimide film which is an example of an organic insulating film is manufactured. This process consists of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (2,2'-TFDB), biphenyltetracarboxylic dianhydride (BPDA) and 2, By condensing 2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6-FDA) in dimethylacetamide by a well-known method, the polyimide precursor solution which is an example of the precursor solution of an organic insulating film (solid content 20%) was obtained. This reaction process is shown in Scheme 1 below.

(Scheme 1)

Subsequently, 300 g of this polyimide precursor solution was added with 2 to 4 equivalents of acetic anhydride (Acet oxide) and pyridine (Pyridine) as a chemical curing agent according to the above-mentioned procedure. After heating the polyamic acid solution at a temperature in the range of 20 to 180 ° C. at a rate of 1 to 10 ° C./min for 2 to 10 hours, the polyamic acid solution was partially imidized and cured by partially imidizing (partially curing). Korean) A solution containing an intermediate was prepared.

The following Reaction Scheme 2 shows a process of heating a precursor of polyimide to obtain a polyimide film. In the embodiment of the present invention, the precursor solution is not completely imidized to form a polyimide, but imidates only a predetermined proportion of the precursor. It was to use one.

(Scheme 2)

More specifically, the polyimide precursor solution is heated and stirred under predetermined conditions to dehydrate and close the ring between the hydrogen atom and the carboxyl group of the amide group of the polyimide precursor, as shown in the following formula (1). Similarly, the form B of the intermediate portion and the form C of the imide portion are generated by the reaction. Further, in the molecular chain, form A (polyimide precursor portion) in which dehydration does not occur completely also exists.

That is, in the molecular chain in which the polyimide precursor is partially imidized, as shown in the following formula (3), structures of the shape A (polyimide precursor portion), the shape B (intermediate portion), and the shape C (imide portion) are mixed. Will be.

Formula 3

Therefore, 30 g of the imidized solution mixed with the above structure was added to 300 g of water to precipitate, and the precipitated solid was finely powdered through filtration and grinding, followed by drying in a vacuum drying oven at 80 to 100 ° C. for 2 to 6 hours. To about 8 g of a resin solid powder. Through the above process, the polyimide precursor portion of [Form A] is converted into [Form B] or [Form C], and the resin solid content is dissolved in 32 g of DMAc or DMF, which is a polymerization solvent, to prepare a 20 wt% polyimide solution. Got it. This was heated for 2 to 8 hours while the temperature was raised at a rate of 1 to 10 ° C./min in a temperature range of 40 to 400 ° C. to obtain a polyimide film having a thickness of 50 μm and a thickness of 100 μm.

When the polyimide precursor partially imidated, the reaction scheme is shown in Scheme 3.

(Scheme 3)

For example, under the above conditions, about 45 to 50% of the precursor is imidized and cured. The imidation ratio which a part of a precursor imidates can be easily adjusted by changing heating temperature, time, etc., and it is preferable to set it as about 30 to 90%.

In the step of imidizing a part of the polyimide precursor, water is generated when the polyimide precursor is dehydrated and closed and imidized, and this water causes hydrolysis of the amide of the polyimide precursor, cleavage of molecular chains, or the like. Since there is a risk of lowering the stability, the Azeotropic reaction using toluene, xylene, or the like is added during heating of the polyimide precursor solution or removed through volatilization of the above-mentioned dehydrating agent.

Next, an example of the process of manufacturing a coating liquid is demonstrated. First, a uniform coating liquid is prepared in the ratio of 100 weight part of solutions and 20-30 weight part of polyimide precursors to the solvent which used the partially hardened intermediate at the time of manufacture of a polyimide precursor.

Subsequently, the resin solution was cast on a film-coated plate for film or film formation such as Sus using spin coating or a doctor blade, and then a film having a thickness of 50 μm was formed through the above-mentioned high temperature drying process. In this case, the film formed was formed with the same refractive index on the entire surface of the film because the film is not subjected to a process in which only one surface is stretched based on the vertical / horizontal axis of one side of the film.

Production Example 2

The reactor was filled with 34.1904 g of N, N-dimethylacetaamide (DMAc) while passing nitrogen through a 100 ml 3-Neck round bottom flask equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a cooler. After lowering the temperature to 0 ° C., 4.1051 g (0.01 mol) of 6-HMDA was dissolved to maintain this solution at 0 ° C. 4.4425 g (0.01 mol) of 6-FDA was added thereto and stirred for 1 hour to completely dissolve 6-FDA. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours. At this time, the solution viscosity at 23 degreeC was obtained the polyamic-acid solution of 2400 cps.

After completion of the reaction, the polyamic acid solution obtained was cast to a thickness of 500㎛ ~ 1000㎛ by using a doctor blade on a glass plate and dried in a vacuum oven for 1 hour at 40 ℃, 2 hours at 60 ℃ to obtain a self standing film A polyimide film having a thickness of 50 μm was obtained by heating at 80 ° C. for 3 hours at 100 ° C., 1 hour at 100 ° C., 1 hour at 200 ° C., and 30 minutes at 300 ° C. in a high temperature furnace oven.

Production Example 3

In Preparation Example 2, 2.9233 g (0.01 mol) of APB-133 was dissolved in 29.4632 g of N, N-dimethylacetamide (DMAc), and 4.4425 g (0.01 mol) of 6-FDA was added thereto, followed by stirring for 1 hour. 6-FDA was completely dissolved. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours. At this time, the polyamic-acid solution whose solution viscosity in 23 degreeC is 1200 cps was obtained.

Thereafter, a polyimide film was prepared in the same manner as in Preparation Example 2.

Physical properties of the polyimide films obtained from Preparation Examples 1 to 3 were measured as follows, and are shown in Table 1 below.

(1) transmittance and color coordinate

The prepared film was measured for visible light transmittance using a UV spectrometer (Varian, Cary 100).

In addition, the color coordinate film was measured according to the ASTM E 1347-06 standard using a UV spectrometer (Varian, Cary100), the light source (Illuminant) was based on the measured value by CIE D65.

(2) yellowness

Yellowness was measured according to ASTM E313.

(3) coefficient of linear expansion (CTE)

TMA (TA Instrument, Inc., Q400) was used to measure the average coefficient of linear expansion at 50-250 ° C. according to TMA-Method.

division thickness
(Μm) Coefficient of linear expansion
(ppm / ℃) Yellow road Permeability Color coordinates 380 nm
780 nm 551 nm
780 nm 550 nm 500 nm 420 nm L a b Manufacturing example One 50 21.6 2.46 86.9 90.5 89.8 89.3 84.6 96.22 -0.27 1.03 2 50 46 1.59 87.6 90.0 89.7 89.2 85.4 95.85 -0.12 0.99 3 50 46.0 6.46 83.8 88.8 87.2 84.8 73.2 94.6 0.59 5.09

Example  One

Hexacosane, a paraffinic hydrocarbon (Hexacosane, n = 26 in Chemical Formula 1, Tokyo Chemical Industry., Co. Ltd) is dissolved in 3% by weight of normal hexane, and a single-walled carbon nanotube (ASP-100F, Hanwha Nanotech) Product) 0.1% by weight was added and dispersed by ultrasonic wave of 200W, 40kHz to obtain a carbon nanotube dispersion.

The obtained carbon nanotube dispersions were visually evaluated for dissolution stability and dispersibility according to the following criteria, and the results are shown in Table 1 below.

(Circle): No aggregation was observed.

(Triangle | delta): Although aggregation was observed slightly, it did not become a problem practically.

X: Aggregation was observed and became a problem practically.

Example 2

Paraffin wax mixture (microcrystalline wax, melting point 65.5 ~ 76.6 ℃, carbon number n = 29 to 37 in the formula (1), Daemyung Chemical, Korea) 0.08% by weight in isobutyl ether dissolved, single-wall carbon nanotube ( ASP-100F, manufactured by Hanwha Nanotech Co., Ltd.) was added 0.1% by weight and dispersed by ultrasonic wave of 200W, 40kHz to obtain a carbon nanotube dispersion.

The dissolution stability and dispersibility of the obtained carbon nanotube dispersions were visually evaluated according to the same criteria as in Example 1, and the results are shown in Table 1 below.

Example 3

A paraffin wax mixture (microcrystalline wax, melting point 101 ° C., n = 60 to 70 carbon atoms in formula (1), Nippon Seiro, Japan) was dissolved 0.08% by weight in Solvent Naphtha and Naphtha, and single-walled carbon nanotubes (ASP-100F , Hanwha Nanotech Co., Ltd.) 0.1% by weight was added and dispersed by ultrasonic wave of 200W, 40kHz to obtain a carbon nanotube dispersion.

The dissolution stability and dispersibility of the obtained carbon nanotube dispersions were visually evaluated according to the same criteria as in Example 1, and the results are shown in Table 1 below.

Example 4

Methyl behenate (melting point 55 ° C., boiling point 393 ° C., Tokyo Chemical Industry., Co. Ltd), an ester compound of the paraffinic hydrocarbon represented by the formula (2), was dissolved in isobutyl ether to 0.08% by weight, and single-wall carbon nano 0.1 wt% of a tube (ASP-100F, manufactured by Hanwha Nanotech Co., Ltd.) was added, and dispersed by ultrasonic wave at 200 W and 40 kHz to obtain a carbon nanotube dispersion.

The dissolution stability and dispersibility of the obtained carbon nanotube dispersions were visually evaluated according to the same criteria as in Example 1, and the results are shown in Table 1 below.

Examples 5-10

A carbon nanotube dispersion was prepared in the same manner as in Example 3, but the carbon nanotube dispersion was obtained by varying the content of the carbon nanotube, the type of paraffinic hydrocarbon, and the like, as shown in Table 2 below.

In Table 3, the content unit is weight%, and the content of the solvent will be understood as 100% by weight, minus the total amount of carbon nanotubes and paraffinic hydrocarbons.

Examples 11-20

On each of the polyimide films obtained from Preparation Examples 1 to 3, the dispersions obtained from Examples 1 to 10 were coated and applied by a spray method or a spin coating method, and then dried in a hot air oven at 250 ° C. to form a conductive film. .

At this time, the thickness of the conductive film was measured by observing the cross section of the prepared transparent electrode film with an electron scanning microscope (SEM).

The conductive laminates obtained from Examples 11 to 20 were evaluated as follows, and the results are shown in Table 5 below.

(1) optical properties

 Visible light transmittance was measured using a UV spectrophotometer (Konika Minolta, CM-3700d) for the prepared laminate.

(2) surface resistance

The surface resistance on the conductive film was measured for the prepared laminate. Surface resistance is measured using an ohmmeter (CMT-SR 2000N (Advanced Instrument Teshnology; AIT, 4-Point Probe System, Measuring range: 10 x 10 ^-3 to 10 x 10 ⁵ )) The range of was evaluated.

(3) the adhesion of the conductive film to the substrate

The rate of change in surface resistance was evaluated after 10 times of peeling and then peeling the 3M Scotch Tape on the conductive film 10 times for the prepared laminate. For the reliability of the evaluation, the same test was repeated 10 times to evaluate the range of the maximum change rate.

Surface resistance
(Ω / □) Transmittance
(550 nm,%) Change rate of adhesion of the conductive film to the substrate
(%) Example 11 10 ^ 6 75 <1.0 Example 12 10 ^ 3 80 <5.0 Example 13 950 82 <5.0 Example 14 950 84 <5.0 Example 15 900 85 <5.0 Example 16 850 84 <5.0 Example 17 750 82 <5.0 Example 18 700 80 <5.0 Example 19 700 78 <5.0 Example 20 700 70 <10.0

From the results of Table 5, the conductive film including the carbon nanotubes according to the embodiment of the present invention satisfies the proper electrical conductivity and has excellent adhesion to the substrate and does not stick to the surface upon contact, and has excellent heat resistance. It can be seen.

From these results, it can be expected that the conductive laminate of the present invention can be used as a transparent electrode, an EMI shield, and an ESD filter.

Examples 21-30

On the polyethylene terephthalate film (thickness 100 μm, Astroll H, manufactured by Kolon Industries, Inc.), the dispersions obtained in Examples 1 to 10 were coated and applied by a spray method or a spin coating method, followed by 5 minutes in a hot air oven at 120 ° C. It dried and the conductive film was formed.

At this time, the thickness of the conductive film was measured by observing the cross section of the prepared transparent electrode film with an electron scanning microscope (SEM).

Conductive film thickness
(nm) Kinds Example 21 350 Example 1 Example 22 150 Example 2 Example 23 250 Example 3 Example 24 200 Example 4 Example 25 150 Example 5 Example 26 150 Example 6 Example 27 250 Example 7 Example 28 300 Example 8 Example 29 350 Example 9 Example 30 300 Example 10

The conductive laminates obtained from Examples 21 to 30 were evaluated as described above, and the results are shown in Table 7 below.

Surface resistance
(Ω / □) Transmittance
(550 nm,%) Adhesion of the conductive film to the substrate Example 21 10 ^ 6 78 <1.0 Example 22 10 ^ 3 83 <5.0 Example 23 950 82 <5.0 Example 24 950 84 <5.0 Example 25 900 88 <5.0 Example 26 850 87 <5.0 Example 27 750 87 <5.0 Example 28 700 83 <5.0 Example 29 700 80 <5.0 Example 30 700 75 <10.0

From the results of Table 7, the conductive film including the carbon nanotubes according to the embodiment of the present invention satisfies the proper electrical conductivity and has excellent adhesion to the PET substrate, and does not stick to the surface upon contact, and has heat resistance. It can be seen that excellent.

Claims (15)

Carbon nanotubes;
At least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof represented by the following Chemical Formulas 1 to 2;
And a conductive dispersion comprising a solvent.
Formula 1
C _n H _{2n + 2}
Wherein n is an integer of 20 or more.

(2)
RCOOR '
_Wherein R is C _l H _{2l + 1 ,} R 'is C _m H _{2m + 1} , l and m are each an integer and the sum thereof (l + m) is an integer of 20 or greater. The conductive dispersion according to claim 1, wherein at least one compound selected from among paraffinic hydrocarbons, isomers and ester compounds thereof has a boiling point of at least 300 ° C. The method of claim 1, wherein the solvent is Naphtha, Solvent Naphtha, Carbon Tetrachloride, Benzene, Chloroform, Dichloromethane, Dichloroethane, Ligroin, Petroleum Ether, Ether, Pentane, Hexane, Heptane, Octane, Isodecane, Alcohol with 95% or more purity At least one selected from acetone and ethyl acetate. The conductive dispersion of claim 1, wherein the carbon nanotubes are present in an amount of 0.01 to 2.0 wt%. The conductive dispersion according to claim 1, wherein at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof is included in an amount of 10 to 5,000 parts by weight based on 100 parts by weight of carbon nanotubes. A conductive laminate comprising a carbon nanotube and a conductive film comprising at least one compound selected from paraffinic hydrocarbons represented by the following Chemical Formulas 1 to 2, isomers and ester compounds thereof.
Formula 1
C _n H _{2n + 2}
Wherein n is an integer of 20 or more.

(2)
RCOOR '
_Wherein R is C _l H _{2l + 1 ,} R 'is C _m H _{2m + 1} , l and m are each an integer and the sum thereof (l + m) is an integer of 20 or greater. The conductive laminate according to claim 6, wherein at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof has a boiling point of at least 300 ° C. The conductive laminate of claim 6, wherein the carbon nanotubes are included in 10 to 95 wt% of the conductive film. The conductive laminate according to claim 6, wherein at least one compound selected from paraffinic hydrocarbons, isomers and ester compounds thereof is included in an amount of 10 to 5,000 parts by weight based on 100 parts by weight of carbon nanotubes. The conductive laminate of claim 6, wherein the conductive film has a thickness of 10 nm to 5 μm. The conductive laminate of claim 6, comprising a substrate selected from a plastic film and a glass substrate. The conductive laminate of claim 11, wherein the plastic film is selected from polyester film, polyimide film, and polycarbonate film. The conductive laminate according to claim 6, which is for a transparent electrode. The conductive laminate according to claim 6, which is for electromagnetic wave shielding. The conductive laminate of claim 6, which is electrostatic discharge (ESD).