KR101675887B1 - Flexible multilayer sheet for transparent electrode and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a multilayer sheet for flexible transparent electrodes, which is integrally provided with functions of scratch resistance, durability and high permeability, antistatic property and electromagnetic shielding function by treating various optical functional sheets with surface multilayer coating and transfer lamination, A variety of photo-functional sheets are coated on a hydrophilic primer coating layer such as a silver nanowire coating to form a selective network, thereby realizing high transparency, antistatic and electromagnetic shielding functions, and transfer laminating treatment, A multilayer sheet for a flexible transparent electrode having improved properties, environmental resistance and durability, and a method of manufacturing the multilayer sheet are provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a flexible multilayer sheet for transparent electrodes,

The present invention relates to a photo-functional sheet for a transparent electrode, and particularly relates to a multilayer coating and transfer lamination process for various photo-functional sheets to provide an integrated scratch resistance, durability, high permeability, antistatic and electromagnetic shielding functions To a multilayer sheet for a flexible transparent electrode and a manufacturing method thereof.

Currently available flexible transparent electrode sheets include various optical functional films having optical, electric and electronic, mechanical strength, heat resistance and chemical resistance functional layers, and transparent electrode materials have a wide range of applications. In addition to display fields such as LCD, PDP, OLED and FED, it is used for touch panel, transparent electromagnetic wave shielding film, transparent heat emitting body, conductive glass and gas sensor.

In addition, it is a key component material for information and electronic energy that can be applied to heat reflection coating film, solar cell, lighting, automobile, transparent antistatic film, antenna for communication equipment, optical filter and the like. In addition, there is a growing need for an input device capable of easily operating a device in a compact and thin computer and multimedia device.

The touch panel, which is a product of thin film sheet for transparent electrode, is a highly reliable touch screen panel (TSP) that combines portability that enables anyone to easily manipulate a computer by touching a button displayed on the display, ) Is often used. The touch panel is widely used in information devices because it can be used for handwriting recognition using a tool. However, it has a low durability and a low transmittance, which is inconvenient to use.

Therefore, various additional functions are added to fabricate multilayer functional films for transparent electrodes having high functionality and high durability with high transmittance.

Korean Patent Laid-Open No. 10-2011-0121783 discloses a multilayer sheet for various functions, which is formed by using a metal oxide (SiO 2, ITO) as a conductive electrode. However, since indium is a rare element and it is expected that the production of ITO thin film for display electrodes will not be possible due to depletion and price increase, it is desired to develop transparent electrode material with high transparency and low resistance to replace indium.

In addition, since the ITO electrode manufactured by sputtering is manufactured in a vacuum, the manufacturing cost is increased, and there is a problem in durability when the ITO electrode is folded repeatedly. Therefore, it is required to develop transparent electrode technology that does not involve impact or vibration beyond the technology of waving or bending with development of alternative technology of indium material.

As described above, it is expected that the wearable electronic device market will be largely formed, and it is expected that the ripple effects will be very great not only in the IT field but also in the sports related industry in the near future.

One of the ways to effectively solve the above problems is to develop a technique that can be applied to a roll-to-roll (R2R) solution process capable of mass production using the most conductive silver nano metal.

Korean Patent Laid-Open No. 10-2008-0013787 discloses a silver nanoparticle and a silver nanocolloid, and a silver ink composition comprising the silver nanoparticle, wherein a silver compound and an ammonium carbamate compound are reacted to form a silver complex compound The present invention relates to a method of manufacturing a silver nano ink for a transparent electrode for the purpose of providing an ink composition capable of forming a coating film or a fine pattern exhibiting high conductivity by preparing various types of silver nanoparticles or silver nanocolloids by a simple manufacturing process .

Also, Korean Patent Publication No. 10-2011-0071526 'Silver nanowire and its manufacturing method and transparent conductive film using the silver nanowire' is also a method of producing silver nanowires (Ag NWs), and silver nitrate Is prepared by dissolving an ionic liquid.

As described in the above-mentioned prior arts, silver nanowires and silver nanoparticle coating solution manufacturing techniques allow roll coating of silver nano solutions instead of vacuum deposition for transparent electrodes.

Meanwhile, the transparent conductive film introduced in Korean Patent Publication No. 10-2011-0071534 'Transparent conductive film and its manufacturing method' is prepared by coating hollow silver and nanowire on a substrate, and a PET film (Poly Ethylene Terephthalate Film) to improve the adhesive strength through plasma ozone treatment, and to form a conductive film with silver nano coating liquid and add anti-reflection film function on the opposite side of PET film.

Korean Patent Laid-Open Publication No. 10-2012-0087454, 'Silver Nanowire Ink Using Water-based Liquid Crystalline Polymer and Method for Manufacturing the Same', forms a transparent electrode and a metal wiring for printing using coating methods such as bar coating and roll coating The present invention relates to a silver nanowire ink using a water-based liquid crystalline polymer and a method for manufacturing the same, and more particularly, to a silver nanowire ink using a water-based liquid crystalline polymer as a dispersant to improve dispersion stability, A transparent electrode or the like is formed.

In addition, the preparation of highly concentrated stable dispersions of uniform silver nanoparticles is described in Journal of Colloid and Interface Science 260 (2003) 75-81. To a silver nitrate solution is added a stabilizer {Daxad 19 (sodium salt of a high-molecular weight naphthalene sulfonate formaldehyde condensate )} To ascorbic acid to obtain a stable water-dispersed silver nano coating solution having a narrow size distribution.

As described above, specific techniques have been proposed for manufacturing silver nano and silver nano ink and coating liquid for transparent electrode through prior patents and articles, but it is necessary to integrate various functions in order to be applied to an actual site.

In the "Evaporation-Induced Self-Alignment and Transfer of Semiconductor Nanowires by Wrinkled Elastomeric Templates", a polydimethylsiloxane (PDMS) film is stretched to form a wrinkled template evaporation-induced self-alignment in a three-phase contact line (TCL) followed by dropping the nanocoating solution after relaxation by ultraviolet-ozone (UVO) alignment technology to form a nanowire conductive pattern in a corrugated fiber groove to be transferred to a desired substrate to be used for a semiconductor or a transparent electrode.

Thus, when the nanowire is entirely coated and self-assembled to form a uniform pattern in micro-size, the transmittance is improved and the use of nanomaterials is reduced and the semiconductor and transparent electrode further processing steps are effective.

As described above, since there is a growing interest in conductive nanoparticles that can be applied to transparent conductive coatings in order to replace materials such as ITO coated by chemical vapor deposition, they have less electrical resistance than CNT solutions, Silver nanowires and silver nanowire solutions with low surface contact resistance are more effective. In addition, silver nanowires are advantageous in production cost, yield, production time, and coating process because they are in the form of a linear rod and are not individually precipitated on the substrate, .

Nevertheless, Korean Patent Registration Nos. 10-0803436 and 10-0790216, Korean Patent Laid-Open Nos. 10-2007-0106704, 10-2009-0027132, 10-2009-0035961, 10-2008 -0065899 discloses that the functional multilayer sheet for a transparent electrode does not consider the overall functions of high light transmittance, durability, antistatic, electromagnetic shielding, gas and moisture barrier. In particular, no consideration has been paid to the protective film or the surface protection function for removing scratches during the assembly line or the product transferring process required for the material parts of the display industry.

In addition, with respect to the display component materials, various kinds of optical functional sheets for a transparent electrode are made into a small thin film, the pattern of electrodes is reduced to nano size, and the electrode density is densely increased, so that a functional material is used. Further, by using a composite material that maximizes the optical functionality, the importance of the protective function of these photo-functional materials and delicate surface patterns is increasing in proportion to the advancement.

Such a sheet for a transparent electrode is required to achieve an antistatic function (a surface resistance of 10-7? / Sq or less) to prevent the particle from being adsorbed, which causes the greatest failure of the assembly line. There is a need to prevent damage to the fine pattern of the photo-functional sheet and safety (electrostatic shock) accident of the operator.

Korean Patent Publication No. 10-2011-0121783 (published on November 09, 2011) Korean Patent Laid-Open No. 10-2008-0013787 (published on Feb. 13, 2008) Korean Patent Publication No. 10-2011-0071526 (published on June 29, 2011) Korean Patent Publication No. 10-2011-0071534 (published on June 29, 2011) Korean Patent Publication No. 10-2012-0087454 (published on 08. 07., 2012) Korean Registered Patent No. 10-0803436 (2008. 02. 40. registered) Korean Registered Patent No. 10-0790216 (Registered on December 21, 2007) Korean Patent Laid-Open Publication No. 10-2007-0106704 (published on November 5, 2007) Korean Patent Publication No. 10-2009-0027132 (published on Mar. 16, 2009) Korean Patent Laid-Open Publication No. 10-2009-0035961 (published on Mar. 13, 2009) Korean Patent Publication No. 10-2008-0065899 (published on July 15, 2008)

Ivan Sondi, Dan V Goia, and Egon Matijevic` Preparation of highly concentrated stable dispersions of uniform silver nanoparticles. Journal of Colloid and Interface Science v.260. 2003; 75-81 Seung Goo Lee et al. Evaporation-Induced Self-Alignment and Transfer of Semiconductor Nanowires by Wrinkled Elastomeric Templates. Advanced Materials v.25. 2013; 2162-2166

Silver nanowires are advantageous in terms of mass production compared to ITO films requiring a vacuum process such as a sputtering method, and can be produced in a solution process, so that the process is easy and can be mass-produced. In addition, due to the low resistance, As a transparent electrode material suitable for flexible devices, especially silver nanowires are attracting attention as materials having a great potential for use as transparent conductors due to their excellent optical properties, flexibility and high conductivity, and have an invisible pattern property It can be applied to touch panels mounted on mobile phones, smart phones, tablet PCs and the like. In addition, it is possible to reduce the resistance required for a large-sized touch panel, and is applicable to a touch panel of three-dimensional shape, an electrode for a solar cell, and an AMOLED in the future.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention to solve the above-mentioned problems is to provide a transparent electrode which forms a network pattern by a simple roll-to-roll coating after self-assembly of silver nanowires, It is an object of the present invention to provide a multilayer sheet for a flexible transparent electrode capable of realizing a stable transparent electrode body which is high in conductivity when applied to a flexible display and is both transparent and warped and stretched.

Another object of the present invention to solve the above problems is to provide a transparent electrodeposition coating composition which is excellent in scratch resistance, durability, high light transmittance, antistatic property, and electromagnetic shielding function by surface multilayer coating and transfer lamination A multilayer sheet for a flexible transparent electrode and a method of manufacturing the same.

It is a further object of the present invention to solve the above-mentioned problems, and it is a further object of the present invention to provide a large-capacity roll-to-roll coating using a silver nanowire coating solution instead of ITO which is a rare metal, And a multilayer sheet for flexible transparent electrodes capable of reducing silver nano materials and a method for manufacturing the same.

The present invention relates to a photo-functional sheet for a transparent electrode, and more particularly, to a photo-functional sheet for a transparent electrode, in which a variety of photo-functional sheets are coated on a hydrophilic primer coating layer such as a silver nanowire coating to form a selective network, And a multilayer sheet for a flexible transparent electrode which has an electromagnetic shielding function and is subjected to transfer laminating treatment to improve scratch resistance, environmental resistance and durability, and a method for producing the multilayer sheet.

In order to attain the above object, in the present invention, a primer formulation having excellent adhesion to a PET film is applied to obtain excellent wettability with a silver nanowire coating liquid, and in the evaporation of a water-soluble cosolvent, The self-assembly is induced by the secondary bonding force between the nanowires to form a cell-shaped network, and a technique of controlling and controlling the cell size is performed. In addition, by applying solvent UV resin composition and antistatic agent formulation, it is possible to form self-assembly pattern of silver nanowire-disperse composite resin which shows scratch resistance, environmental resistance, durability, stain resistance and antistatic function, transfer laminating and multilayer thin film coating (Multi-coating layer) technique and a method of manufacturing the same.

The present invention has the effect of mass-producing the silver nano-wire composite resin coating solution replacing ITO, which is a rare metal, at a low cost by carrying out roll ball coating.

In addition, the present invention has an advantage of providing silver nano materials and excellent visible light transmittance by inducing selective self-assembly of silver nanoparticles to form a network.

In addition, the present invention can be used as a substitute for a protective sheet for dust absorption and static electricity prevention and a backlight unit, as well as for surface protection of functional sheets in the process of assembly of display material parts by UV curable resin and AS coating, By simultaneously working in the clean room up to the surface protective adhesive film, the stain resistance can be originally achieved, which is very economical.

In addition, since the present invention is expected to lead the next generation display technology in a thin and lightweight paper-like display in view of the development direction of the display, it is expected that a flexible display The transparent conductive film can be mass-produced.

Accordingly, the nanowire coating of the present invention is effective in reducing the production cost of high-capacity roll-to-roll coating and excellent warping property, thereby improving export competitiveness, improving trade balance, There is an advantage that it can be applied to the industry of the next generation base technology (plastic electronic device, ultra thin film information storage, high capacity thin film battery, next generation display).

In addition, the present invention is advantageous in that it is possible to completely prevent contamination and to prevent defects by completing a material part from an in-line to a surface adhesive tape for removal, in parallel with a production line of a photo-functional sheet, It has the effect of improving export competitiveness.

1 is a cross-sectional view of a multilayer sheet for a flexible transparent electrode according to the present invention,
2 and 3 are sectional views of first and second multilayer sheets applied to a multilayer sheet for a transparent electrode according to the invention,
4 is a process diagram for explaining a process of manufacturing a multilayer sheet for a transparent electrode according to the present invention,
5A and 5B are ICP analyzes of silver nanowires applied to the multilayer sheet for a transparent electrode according to the present invention,
6A to 6D are electron microscopic and optical micrographs of the conductive layer constituting the multilayer sheet for a transparent electrode according to the present invention,
7 is a cross-sectional view of a multilayer sheet for a flexible transparent electrode according to another embodiment of the present invention,
8 and 9 are cross-sectional views of a first multilayer sheet according to another embodiment of the present invention,
10 is a view showing a manufacturing process of a multilayer sheet for a flexible transparent electrode according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. It should be noted that the same configurations of the drawings denote the same reference numerals as possible whenever possible. It is to be understood that the present invention is not limited to the specific embodiments and that all changes, modifications, and alterations included within the spirit and scope of the present invention are intended to be illustrative, It is to be understood that the invention includes equivalents and alternatives. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

The terminology used in the description is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

The present invention relates to a display industry, and more particularly, to a multilayer sheet for a flexible transparent electrode applicable to a flexible display. Flexible displays can be flexibly and flexibly mounted on a display that can be folded like a piece of paper, and are considered the next generation of flat panel displays with a wearable display.

The biggest challenge in implementing such a flexible display is that it must be able to carry around like a piece of paper, but still be able to reproduce all the important characteristics of today's flat panel displays.

In the conventional pixel electrodes of flat panel displays, ITO (indium tin oxide) is mainly used as a transparent electrode coated with a thin film on a PET film or a glass substrate by sputtering. However, ITO using indium as a raw material, which is a rare metal, There is no further appeal due to the risk of depletion due to the increase in the cost of production due to the increase in the price and the vacuum deposition equipment.

As a substitute material for ITO, it is possible to apply a large-capacity roll-to-roll (R2R) coating, and silver, which has the best conductivity, is in the spotlight. In particular, flexible transparent electrodes using silver nanowires have been proposed in domestic and foreign patents and articles, and some are being commercialized. Therefore, by using this silver nanowire technology, it has been proposed to replace ITO by improving and supplementing "manufacture of multilayer sheet for transparent electrode", Korean Patent Registration No. 10-1292242 filed and registered by the present applicant.

The multilayer sheet for a flexible transparent electrode according to the present invention is characterized in that the silver nanowire is made into a large-capacity roll-to-roll coating solution, and a hydrophilic primer coating and a silver nanowire coating solution, which form a network pattern, And the self-assembly is formed by the secondary bonding force between the silver nanoparticles in the solvent drying process, thereby reducing the use of silver nanowires and improving the transmittance of visible light.

The hydrophilic primer coating solution used for the PET film is usually an aqueous solution, and a silane compound or a water-soluble resin containing a hydrophilic functional group and a solvent are used. Since it has wettability with the PET film and has the adhesive property due to the secondary bonding force between the polymer chain and the pulverization, the surface energy of gc = 43 mJ / m < 2 >Lt; / RTI >

In the present invention, various resins and cosolvents are used in consideration of the adhesion to the PET film and the interaction with the silver nanowire coating solution. The primer coating solution is prepared by mixing 10-50 wt.% Of a resin and 50-90 wt.% Of a solvent, coating the coating with 5 μm, removing the solvent in an oven, and then forming a conductive film with silver nanowire coating thereon.

 The primer resin used in the present invention is a resin having a hydrophilic functional group such as N- (2-hydroxyethyl) hexadecanamide (CAS Number 544-31-0), 2.6-bis (1.1-dimethyl) phenol (CAS Number 128-37-0), Trimethoxy (octadecyl) silane (CAS Number 3069-42-9), 2,2'-Methylenebis (6-tert- 1), 1,2-Benzenediol, 4,4 '- [1,6-hexanediylbisimino (1 -hydroxy-2,1-ethanediyl)]] bis- (CAS Number 3215-70-1), Acetic acid, p-menth-3-yl ester (CAS Number 16409-45-3), 2-methyldecane-2,5-diol (CAS Number 53731-34-3), Poly (vinyl acetate) ).

The primer composition consisted of resin and various solvents (DI water, methanol, IPA, 2-butene-1,4-diol (CAS No. 110-64-5), 1,3-Propanediol (CAS No. 115-77-5 ), 5-methyl-2- (1-methylethyl) -cyclohexanol (CAS No. 1490-04-6), and 1,2,3-trimethyldiaziridine (CAS No. 13604-56-1) Preferably, the wettability is improved on the optical PET film by mixing 3-4 solvents in consideration of the solubility parameter and the volatilization rate (different boiling point of the solvent) to 100 cps in viscosity. And dried and passed through a dry oven at 120 ° C. to remove moisture and all the solvent to form a dry film (1-2 μm).

The silver nanowires are obtained in an ascorbic acid atmosphere by the well known silver reduction method as the following reaction formula.

Since the acid (H +) continues to be generated as silver is reduced in the above reaction equation, the basicity should be used as a neutralizing agent to increase the yield in the equilibrium reverse reaction. Typically, hydrazine or formaldehyde is used. In the present invention, in order to obtain more stable silver nanowires, hydrazine, formaldehyde, 1,2,3-trimethldiaziridine (CAS No. 113604-56-1), 2,2-dimethyl-1,3-propanediamine 7328-91-8), sodium polynaphthalene sulfonate (CAS number 36290-04-7) was further used, ascorbic acid was dropped at a rate of 3 cc / min, and possible nanowire crystals Silver nanowires with constant growth and narrow size distribution are fabricated.

The silver nanowire thus prepared was washed several times with a water-soluble solvent, separated by a centrifuge, washed again with acetone and methyl ethyl ketone (MEK), dried in an oven (80 ° C) To obtain nanowire powder. The resultant silver nanowire powder was analyzed by ICP, and the silver component was confirmed, which is shown in FIGS. 5A and 5B. In addition, the shape of the silver nanowires in the conductive film dispersion coating solution is as shown in FIGS. 6A to 6D by an electron microscope (SEM) and an optical microscope observation.

Meanwhile, silver nanowires are sold in powder form in domestic and overseas companies, and they are also sold in the form of coated with a binder such as dispersing agent or PVP. Therefore, in the present invention, A coating solution may be prepared, and a highly transparent self-assembled conductive layer may be formed and a multilayer sheet for a flexible transparent electrode may be prepared using the self-assembled conductive layer.

First of all, unlike metal nano, which is usually made of copper, gold, silica, etc., nanowire coating solution is prepared by nanowire (10-150 nm) in short axis and micro (1-15 μm) ). When fast dispersion is needed, it is dispersed using ultrasonic waves.

In addition, an adhesive force is required to form a conductive film on the PET film and to maintain the durability of the conductive layer stabilized repeatedly several thousand times. Therefore, a silver nanowire coating solution is prepared by using a primer and using a binder associated with the primer to be used, taking into consideration self-assembly, interfacial adhesion, coating property, and workability.

In the preparation of the silver nanowire coating solution, silver nanowires were washed with deionized water (DI water) at pH 7, precipitated by centrifugation, and then washed once with acetone and MEK Further wash and dry in oven at 80 ° C. The reason for this treatment is to prevent deterioration of interfacial adhesion and contamination of precision parts due to the leakage of low molecular weight amine-based organic materials, to improve durability and, among other things, to increase the content of silver nanowires .

As described above, the silver nanowire coating solution used in the multilayer sheet for a flexible transparent electrode according to the present invention is prepared by adding at least the binder and dispersant necessary for redispersion of the silver nanowires and minimizing the desired physical properties Even if added enough to exert such effect, the entire amount is removed from the drying furnace after the coating, so that it does not affect the conductivity or other functions.

On the other hand, in the prior arts such as Korean Patent Laid-Open Nos. 10-2008-0013787, 10-2012-0087454, 10-2006-0108875, and 10-2011-0071526, The silver nanowire colloid solution was prepared by adding various acids / bases, catalysts, and other additives in order to synthesize silver nanowires. Thus, There is a difference in adhesion, interfacial adhesion and high boiling point low molecular weight, and there is a risk of leakage of various functional organic matters.

In fact, a so-called Product Champion is a global company that manufactures low-cost silver nanowires using a variety of acid / base additives and catalysts to make silver nanowires. ratio silver nanowires as well as resin-coated silver nanowires.

Accordingly, in the present invention, silver nanowires are separated from a silver nanowire colloid solution of various organic and inorganic additives as described above to prepare a coating solution.

Hereinafter, the process for producing the silver nanowire dispersion coating solution applied to the multilayer sheet for a flexible transparent electrode according to the present invention will be described in detail.

First, premixing the silver nanowires with water-soluble co-solvent, mixing the resin (binder and dispersant) in the other flask with a water-soluble co-solvent to form a solution, To prepare a wire coating solution. The solvent used here is DI water, methanol, isopropyl alcohol (IPA), tetrahydropyran (THF), chloroform, 2-butene-1,4-diol (CAS No (CAS No. 115-77-5), Nitrosomethane (CAS number 865-40-7), 5-methyl-2- (1-methylethyl) -cyclohexanol (CAS No. 115-77-5), 1,3-Propanediol 1,2,3-Trimethl diaziridine (CAS No.113604-56-1)) is preferably used in combination. The solubility parameter and the volatilization rate (2-hydroxyethyl) hexadecanamide (CAS Number 544-31-0), 2.6-bis (1.1-dimethyl) hexamethylenediamine, and the like. -4-methylphenol (CAS No. 128-37-0, 2,2'-Methylenebis (6-tert-butyl-4-methylphenol) (CAS No. 119-47-1), 1,2- Bis (CAS No. 3215-70-1), 6-Methyl-2-pyridinecarboxylic acid (CAS No. 934 -60-1), Monophenylurea (CAS n 2-pyrolidinone, 1-methyl (CAS number 872-50-4), Polyvinylpyrrolidone (CAS No. 9003-8-3), bis (aniline) dichlorozinc (II) (CAS number 13869-81-3) 39-8), and polyvinyl alcohol (PVA) (CAS No. 9002-89-5).

At this time, the viscosity of the final coating solution is lowered to 150 cps to improve the wettability of the film on the optical PET film, and the dried film (2-3 μm) is formed by passing moisture and all the solvent through a 120 ° C. drying furnace.

On the other hand, the biggest problem of the optical PET film widely used at home and abroad due to the ease of processing, low weight, flexibility, and suitability of the continuous process is due to lack of scratch and heat resistance. The PET film, which is the main material of the display film, has a poor surface strength, resulting in many defects due to scratches during the process.

Therefore, UV hard coating helps to improve mechanical strength and heat resistance in PET film, and plays an important role in preventing scratches in conductive coatings and other manufacturing processes by strengthening the surface of PET film in particular.

In addition, a film such as a PE film (Polyethlyene Film) is laminated to the surface of the functional sheet to protect the surface of the object to be protected at the time of post-processing, and the product is stable from adsorption of fine dust . Such a film is a kind of protective adhesive tape that is removed in post-processing and other assembly processes. It is an indispensable protective film for display, precision parts and information communication parts manufacturing processes. It is essential for continuous processes from the manufacturing process of the multilayer sheet to the assembly process do.

Therefore, it is necessary to use a protective adhesive tape for the purpose of preventing contamination or surface damage during manufacture, processing, transportation and storage of multilayer sheets, but secondary contamination by the adhesive tape must be completely eliminated.

The multilayer sheet for a flexible transparent electrode according to the present invention shown in FIG. 1 is preferably formed by first preparing the first and second multilayer sheets shown in FIG. 2 and FIG. 3, and then laminating them.

2, the first multilayer sheet includes a CNT composite resin adhesive layer 40 for preventing electrification and electromagnetic shielding on the top surface of a PET film 30 serving as a base film, 3 is laminated on the bottom surface of the PET film 30 and a UV hard coating layer 20 for strengthening the surface and a pressure sensitive adhesive layer 11, Pressure-Sensitive Adhesive (PSA) and a protective film 10 for removal. Here, the pressure-sensitive adhesive layer 11 and the protective film 10 may be provided as a pressure-sensitive adhesive protective film in which the pressure-sensitive adhesive layer 11 is formed on the protective film 10 separately from the first multilayer sheet production process.

3, the second multilayer sheet includes a PET film 50, a primer coating layer 60, a conductive (silver nanowire coating) layer 70, a pressure sensitive adhesive layer 81 and a protective film 80 for removal can be prepared by coating and transfer lamination. 3, the pressure-sensitive adhesive layer 81 and the protective film 80 are provided as an adhesive protective film having a pressure-sensitive adhesive layer 81 formed on the protective film 80 separately from the second multilayer sheet manufacturing process .

The multilayer sheet for flexible transparent electrodes according to the present invention is completed as shown in FIG. 1 by laminating the first multilayer sheet and the second multilayer sheet manufactured as described above.

7, in which the CNT composite resin adhesive layer 40 and the PET film 30 formed for preventing electrification are omitted, since the electromagnetic wave shielding function can be expected in the conductive layer 70 formed by silver nanowire coating In this case, functional layers may be coated and transferred onto the upper and lower surfaces of the PET film 50, not the laminate of the first and second multilayer sheets, respectively.

The protective film used in the present invention is usually made of polyethylene or PET film, but is not limited thereto.

The release film 41 formed on the uppermost layer of the first multilayer sheet for lamination of the first multilayer sheet and the second multilayer sheet was prepared by mixing the Dow Corning 176 catalyst or the Syl-Off 23A catalyst with 30% solids using a xylene solvent The release agent is applied on the general film in a thickness of 1-5 탆 and dried at 120 캜.

The CNT composite resin adhesive layer 40 is formed by mixing a multi-wall carbon nano tube (MWCNT), a dispersing agent (sodium dodecyl sulfate, SDS, etc.), a sticking resin (polymethacrylic, PMA, The dispersed mixed solution was divided into a centrifugal separator and rotated at 1350 rpm for about 10 minutes. The pure mixed solution and the conductive polymer were combined at a constant ratio and spread evenly on the film using the BAR coating method After drying on a dryer (80 degrees Celsius), when it is completely dried, remove it and set the range to 1K-100M (Ohm) using a multimeter resistance meter (keithley2700). Then measure resistance and electromagnetic shielding rate against film surface area Respectively.

8). In this case, a methylhydrogen dimethylsiloxane copolymer (CAS68037- 59-2) and an amino siloxane (CAS 192888-42- 9) are mixed at a weight ratio of 1: 1. The solvent is diluted with toluene or methyl ethyl ketone (MEK) and used as a solid content of 20%.

As the antistatic agent, a stable conductive polymer is used in place of the surfactant system which can induce the transition, while avoiding the inorganic system which affects the UV-visible and light-scattering / transmission. In the present invention, a standard for performing an appropriate antistatic function to prevent operator safety and particle adsorption is a surface resistance of 109? / Sq, which is a specification required in the display industry by various conventional tests.

In this embodiment to be described below, the antistatic function is implemented in two forms. One was a mixture of an antistatic agent containing a methylhydrogendimethylsiloxane copolymer (CAS68037-59-2) and an amino siloxane (CAS192888-42-9) as various conductive polymers in a UV coating solution, and the other was an antistatic agent The solution was first coated to form an antistatic agent layer, and a UV resin solution was coated thereon to form a UV hard coat layer 20, thereby completing the surface protection treatment.

The UV resin solution was prepared by mixing 20-60 wt% of an oligomer, 10-50 wt% of a diluent, and 10-50 wt% of a solvent, removing the solvent in an oven, (17) to form a UV hard coating (20) layer.

The oligomer used in the present invention is a multi-functional aliphatic urethane acrylate system, for example, BR-900 series of Bormar including BR-941, BR-970 and BR-990, MIRAMER PU-340 aliphatic trifunctional urethane acrylate, MIRAMER PU-350 aliphatic trifunctional urethane acrylate, and Sartomer's CN9010 aliphatic polyisocyanate, such as the MIRAMER PU-610 aliphatic hexafunctional urethane acrylate, MIRAMER PU-620 aliphatic hexafunctional urethane acrylate, MIRAMER PU- Urethane acrylate oligomer, CN989 aliphatic urethane acrylate CN966H90, SR306 blend urethane acrylate, and SR256 blend CN963A80 urethane acrylate.

The reason for selecting the polyfunctional aliphatic urethane acrylate in the present invention is that compatibility, durability, light resistance and scratch resistance of the antistatic agent (conductive polymer) are taken into consideration. Specifically, in order to exhibit desired physical properties with a thin film of 5 μm or less The reaction site of the oligomer or the reactive monomer should be at least 4, so that the urethane having the high elongation and the tough nature is introduced rather than the acrylic resin.

In addition, in the present invention, a solvent type UV resin composition was selected in order to prevent deformation and residual stress of the photo-functional fine pattern. The solventless UV resin has a high molecular weight due to the use of a diluent relative to the oligomer due to its high viscosity, resulting in poor thermal stability, shrinkage resistance and tensile strength.

The solvent type UV resin composition is prepared by mixing a variety of solvents (toluene, EA, MEK, IPA) with oligomers and diluents (reactive monomers), preferably with a solubility parameter and a volatilization rate ), 3-4 kinds of solvents are mixed to lower the viscosity to 150 cps, thereby improving the wettability of the film on the optical PET film and removing the solvent and residual moisture while passing through the 120 ° C drying furnace to form a thin film In the process, the stress that exists between the UV coating solution and the PET film is removed, and the oligomer and the diluent are dispersed in a certain thickness, and then they are completely cured by UV irradiation under nitrogen gas purge (reflux).

As described above, in the case of using the solvent type UV resin composition according to the present invention, it is not necessary to use the hydrolyzable silane compound disclosed in Korean Patent Laid-Open No. 10-2000-000623 for air blocking and residual water removal, As shown in FIG. 4, by removing moisture and volatile substances in the 120 ° C. drying furnace (chamber 5), the surface pattern is UV-cured at a thinner and higher boiling point and under a nitrogen gas reflux Is improved to achieve almost complete curing conditions.

The diluent (reactive monomer) used in the present invention may be at least one selected from the group consisting of trimethylolpropane triacrylate (TMPTA), tripropylene glycol diacrylate (TPGDA), acryloyl morpholine (ACMO) Di-trimethylolpropane triacrylate (DMPTA), dipentaerythritol pentaacrylate (DEPTA), pentaerythritol tetraacrylate (PETA) and ER M600 dipentaerythritol hexaacrylate (Dipentaerythritol hexaacrylate, DEHA).

The solvent used in the present invention may be selected from the group consisting of ethyl acetate, butyl acetate, toluene, xylene, and methyl ethyl ketone (MEK), and may be used in combination of two or more. Examples thereof include ethyl acetate, butyl The mixing ratio of acetate, toluene and xylene is preferably 3: 3: 2: 1, more preferably 2: 2: 3: 4 when ethyl acetate, butyl acetate, toluene and methyl ethyl ketone are mixed, But is not limited thereto.

On the other hand, in the case of forming a mixed layer in which the antistatic agent and the UV resin composition are mixed as described above, the mixing ratio of the antistatic agent and the UV resin composition is preferably from 20: 1 to 15: 1, And then dried in a drying furnace 130 at a temperature of 70-120 ° C as shown in FIG. 4, and cured by irradiating UV at 500 mJ / cm 2 in a UV chamber 140. In this case, in order to overcome the disadvantages of coating property, adhesion property, residual stress, oligomer molecular weight and content limit and limitations of various formulations according to high viscosity, the present invention uses UV curing after drying using a solvent.

The pressure sensitive adhesive (PSA) used in the present invention is an acrylic pressure sensitive adhesive which is prepared by putting various acrylic monomers into ethyl acetate as a solvent and adding an azo compound (AIBN) and peroxide of Wako, a polymerization initiator, into an acrylic copolymer use. For example, it is preferable to add 5-10 wt% of isobutyl acrylate monomer, 5-10 wt% of 2-ethylhexyl acrylate monomer, 5-10 wt% of vinyl acetate monomer, 2- 5-10 wt% of monomer, 10-20 wt% of ethyl acrylate monomer, 3-8 wt% of acrylamide, 5-10 wt% of acrylic acid, 40-50 wt% of ethyl acetate as solvent, 2,2-azo 0-5% by weight of 2,2-azobis (2,4-dimethyl valeronitrile) and 0-5% by weight of benzoyl peroxide as a peroxide And the polymerized high-functional acrylic copolymer can be used, but is not limited thereto.

The protective film used in the present invention can be produced by the method described in Korean Patent Laid-Open No. 10-2002-0072653, so that a detailed description thereof will be omitted.

Finally, the silver nanowire coating solution forming the conductive layer 70 is prepared by mixing the washed and dried silver nanowire powder (see FIG. 5A) with a dispersing agent (sodium polynaphthalene sulfonate, polyvinylpyrrolidone) and a water soluble cosolvent (DI water, IPA, etc.) (2-Hydroxyethyl) hexadecanamide, 2,2'-Methylenebis (6-tert-butyl-4-methylphenol) and the like) in a solvent (DI water, 1 , 2-butene-1,4-diol, 1,3-propanediol, etc.) were added and mixed in a high-speed mixer. 150 cps.

An electron microscope (SEM) and an optical microscope photograph of the self-assembled shape of the conductive film formed by applying the silver nanowire coating solution to the PET film formed with the primer treatment layer 60 are shown in FIGS. 6A to 6D. FIG. 6A shows a pattern (cell shape) formed by self-assembly of silver nanowires, FIG. 6B shows a self-assembled complex of silver nanowires on a cell wall, and FIG. It is a particle of silver nanowire that is not complexed in the cell. 6D is a graph showing the wall thickness and cell size of the patterned cells. The pattern size measured in Figure 6d is of sufficient size for signal transmission of the touch panel transparent electrode.

Hereinafter, a manufacturing process of a multilayer sheet for a flexible transparent electrode according to the present invention will be described in detail with reference to FIGS. 1 to 4 and FIGS. 7 to 10. FIG.

FIGS. 8 and 9 are cross-sectional views of a first multilayer sheet according to another embodiment of the present invention, and FIG. 10 illustrates a manufacturing process of a multilayer sheet for a flexible transparent electrode according to the present invention.

2, a PET film 30 having a thickness of 25 mu m is prepared (step 201), and then a solvent type UV light (not shown) is formed on the PET film 30, The UV hard coating layer 20 is formed by coating the resin with a thickness of 5 占 퐉, passing through the drying furnace 130, passing through the UV chamber 140 under nitrogen gas reflux and completely curing the UV hard coat layer 20 (step 203). At this time, as shown in FIG. 8, the UV resin may be coated after forming the antistatic agent layer 13 by coating the antistatic agent with 1-2 .mu.m before coating the UV resin.

Before or after the formation of the UV hard coating layer 20, the above-described releasing agent is coated (110) on the ordinary film such as PET film or paper, dried in the backside drying furnace 120, The release film 41 is completed by coating the resin adhesive layer 40 with a coating of 100 占 퐉 and drying 130 (at this time, UV irradiation, etc.). The finished release film 41 is wound on a winder 150 and then transferred to a joint rewinder 160. A release film 41 is formed on the back surface of the PET film 30 on which the UV hard coating layer 20 is formed, Thereby completing the first multilayer sheet having the structure shown in Fig.

Here, the base film of the release film 41 is laminated while the first multilayer sheet of FIG. 2 and the second multilayer sheet of FIG. 3 are joined together to produce the multilayer sheet of FIG.

On the other hand, as described above, an antistatic agent may be mixed with the UV resin as shown in Fig. 9, if necessary.

Hereinafter, the multilayer sheet for a flexible transparent electrode according to the present invention will be described in more detail with reference to examples. It will be apparent to those skilled in the art that these embodiments are for describing the present invention only in detail and that the scope of the present invention is not limited by these embodiments in accordance with the gist of the present invention.

≪ Example 1 >

A UV hard coating layer, a CNT composite resin adhesive layer, and a sheet performing a conductive layer function were prepared according to the silver nanowire and the UV resin composition shown in Table 1 below, and their viscosity, film strength, surface resistance, Respectively.

In order to produce the first multilayer sheet shown in FIG. 8, a release agent prepared by mixing Dow Corning 176 catalyst in a xylene solvent and having a 30% solids content was coated on one side of a PET film (not shown) The release film 41 having the releasing agent layer formed thereon is completed and the acrylic adhesive agent is coated on the releasing agent layer 10 μm and dried to form the pressure sensitive adhesive layer 40. Then, And is mounted on the joint rewinder 160.

Then, a mixture of methylhydrogendimethylsiloxane copolymer (CAS 68037-59-2) and amino siloxane (CAS 192888-42-9) was mixed on the PET film 30 at a ratio of 1: 1 and diluted with toluene to prepare an antistatic agent with a solid content of 20% Coated with UV-curable resin to form an antistatic agent layer 13, followed by coating 5 μm of solvent-type UV curable resin, passing through the drying furnace 130, And completely hardened to form the UV hard coat layer 20. [

Thereafter, the adhesive layer of the release film 41 attached to the joint rewinder 160 in the winder 150 is used to bond the PET film 30 formed with the UV hard coating layer 20 and the protective film 10, .

8, a CNT composite resin adhesive layer 40 and a release film 41 were formed on the back surface of the PET film 30 and an antistatic agent layer 13 was also formed.

Next, as shown in FIG. 3, a primer was coated 3 μm on the plasma-treated PET film 50 and completely dried in an oven to form a primer treatment layer 60, followed by coating a silver nanowire coating solution 5 μm And dried in the 30 m drying furnace (chamber 7) of FIG. 4 to form the conductive layer 70. The primer treatment layer 60 may be omitted if necessary.

As shown in FIG. 4, the multilayer sheet production line for flexible transparent electrodes according to the present invention is designed to adjust the temperature gradient for each chamber. Therefore, the line is slightly different depending on the kind of coating liquid and coating speed, A typical temperature gradient was used.

After completing the sheets of FIG. 8 and FIG. 3 in the process line of FIG. 4, the two sheets were laminated to complete the multilayer sheet for flexible transparent electrode of Example 1. When the first and second multilayer sheets are laminated, the PET film (not shown) which is the base film of the release film 41 described above is removed.

≪ Example 2 >

As shown in Fig. 9, in comparison with the above-described Example 1, except that the antistatic agent and the UV curing resin were mixed to form one layer, that is, the antistatic and UV hard coating layer 21 were formed Is the same.

Meanwhile, the CNT dispersion solution used for the CNT composite resin adhesive layer 40 may be centrifuged and purified. The first multilayer sheet having the structure shown in FIG. 9 was prepared in the same manner as in Example 1, and then laminated on the second multilayer sheet having the conductive layer sheet to complete the functional multilayer sheet for transparent electrodes of Example 2 Respectively.

As described above, the present invention is expected to greatly contribute to the development of a new flexible device market in the future by replacing existing silicon and metal electrodes. In particular, as demand for electronic devices and devices that are bent or folded increases, flexible displays It is expected to be applied to wearable materials, sports-related transparent electrodes and LEDs, which are growing rapidly in recent years.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

Claims (11)

delete delete delete delete delete delete delete delete delete delete Preparing a base film for a first multilayer sheet;
Forming a UV hard coating layer on one side of the base film for the first multilayer sheet;
Preparing a base film for a release film;
Coating a releasing agent layer on the release film base film;
Forming a CNT composite resin adhesive layer on the release agent layer to complete a release film;
Laminating the release film on the other surface of the base film for the first multilayer sheet;
Transferring the release agent layer onto the UV hard coating layer to complete the first multilayer sheet;
Preparing a base film for a second multilayer sheet;
(2-Hydroxyethyl) hexadecanamide, 2,6-bis (1,1-dimethyl) -4-methylphenol, 2,2'-Methylenebis -Benzenediol, 4,4'- [1,6-hexanediylbis [imino (1-hydroxy-2,1-ethanediyl)]] bis-, Poly (vinyl alcohol) and DI water, methanol, IPA, 2- Butene-1,4-diol, and 1,3-propanediol is mixed with 10-50 wt% of a resin and 50-90 wt% of a solvent, followed by coating with a hydrophilic primer coating solution Removing the solvent to form a hydrophilic primer treatment layer on one side of the base film for the second multilayer sheet;
The silver nano wires extracted from silver nano wire colloid solution by washing with DI water, acetone, and methyl ethyl ketone (MEK) and centrifuged were dissolved in DI water, methanol, IPA, 2-butene- 3-Propanediol, and Nitrosomethane, and the dispersant selected from sodium polynaphthalene sulfonate and polyvinylpyrrolidone is separately stirred in the water-soluble cosolvent, and then the pre-blended silver nanowire solution and the dispersed dispersant And a binder solution to prepare a silver nano wire coating solution, and coating the silver nano wire coating solution on the primer treatment layer to form a silver nano wire conductive layer;
A pressure-sensitive adhesive layer on the conductive layer; And a protective film are laminated in this order to complete a second multilayer sheet;
Removing the release film base film from the first multilayer sheet; And
And roll-to-roll the first multilayer sheet from which the base film for the release film has been removed, onto the other surface of the base film of the second multilayer sheet.

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