KR20150126470A - Transparent conductive film and touch panel comprising the same - Google Patents

Abstract

The present invention relates to a transparent conductive film and a touch panel including the same. The present invention includes a transparent member; a high refractive layer formed in an upper part of the transparent member; a low refractive layer formed in an upper part of the high refractive layer; and a transparent conductive layer formed in an upper part of the low refractive layer. The high refractive layer is formed of a composite for coating the high refractive layer, including a siloxane compound of a chemical formula 1 and a metal alkoxide compound of a chemical formula 2: [Chemical formula 1] (R1)n-Si-(O-R2)4-n. [Chemical formula 2] R3-O-M. The R1 is carbon number 1 to 18 of an alkyl group, a vinyl group, an allyl group, an epoxy group, or acrylic group. The R2 is carbon number 1 to 6 of the alkyl group or acetyl group. The n is an integer of 0<n<4. The M is titanium, zirconium, or aluminium.

Description

TECHNICAL FIELD [0001] The present invention relates to a transparent conductive film and a touch panel including the transparent conductive film.

The present invention relates to a transparent conductive film and a touch panel including the transparent conductive film.

The touch panel includes an optical system, an ultrasonic system, an electrostatic capacity system, and a resistive film system depending on the position detection method. The resistance film type touch panel has a structure in which a transparent conductive film and a glass having a transparent conductive layer are arranged to face each other with a spacer interposed therebetween and a voltage is measured in a glass having a transparent conductive layer attached thereto by passing a current through the transparent conductive film . On the other hand, a capacitive touch panel has a basic structure having a transparent conductive layer on a substrate, and is characterized by the absence of a movable part, and has a high durability and a high transmittance.

The transparent conductive film to be applied to the touch panel usually has a high refractive index layer, a low refractive index layer and a conductive layer sequentially formed on one surface of the transparent substrate from the transparent substrate side. In recent years, the refractive index of the high refractive index layer Studies on a transparent conductive film having excellent index matching have been continued.

The present invention relates to a transparent substrate; A high refractive index layer formed on the transparent substrate; A low refractive index layer formed on the high refractive index layer; And a transparent conductive layer formed on the low refractive index layer, wherein the high refractive index layer comprises a composition for high refractive index layer coating comprising a siloxane compound of the formula (1) and a metal alkoxide compound of the formula (2)

[Chemical Formula 1]

(R1) _n- Si- (O-R2) _4-n

(2)

R3-O-M

Wherein R 1 is an alkyl group having 1 to 18 carbon atoms, a vinyl group, an allyl group, an epoxy group or an acrylic group, and R 2 and R 2 are an alkyl group having 1 to 6 carbon atoms or an acetyl group, , And M is titanium, zirconium or aluminum.

However, the technical problem to be solved by the present invention is not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

The present invention relates to a transparent substrate; A high refractive index layer formed on the transparent substrate; A low refractive index layer formed on the high refractive index layer; And a transparent conductive layer formed on the low refractive index layer, wherein the high refractive index layer comprises a composition for high refractive index layer coating comprising a siloxane compound of formula (1) and a metal alkoxide compound of formula (2)

[Chemical Formula 1]

(R1) _n- Si- (O-R2) _4-n

(2)

R3-O-M

Wherein R 1 is an alkyl group having 1 to 18 carbon atoms, a vinyl group, an allyl group, an epoxy group or an acrylic group, and R 2 and R 2 are an alkyl group having 1 to 6 carbon atoms or an acetyl group, , And M is titanium, zirconium or aluminum.

The siloxane compound may be an alkoxysilane compound; And a functional silane compound substituted with at least one selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an acryl group, a glycidyl group, and combinations thereof.

The siloxane compound may include a polymeric siloxane compound having a network structure formed by the sol-gel reaction of the siloxane compound.

The weight average molecular weight of the polymeric siloxane compound may range from 3,000 to 55,000.

The polymeric siloxane compound may be 0.1 part by weight to 100 parts by weight based on 100 parts by weight of the siloxane compound.

The metal alkoxide compound may be 50 to 1000 parts by weight based on 100 parts by weight of the siloxane compound.

The transparent substrate may be a film made of at least one selected from the group consisting of PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), PES (polyethersulfone), PC (polycarbonate), PP (polypropylene) and norbornene resins.

The refractive index of the high refractive index layer may be 1.58 to 1.74.

The thickness of the high refractive index layer may be 200 nm to 1.0 탆.

The refractive index of the low refraction layer may be 1.40 to 1.45.

The thickness of the low refraction layer may be 10 nm to 30 nm.

The transparent conductive layer may be formed of ITO (Indium Tin Oxide) or FTO (Fluorine-doped Tin Oxide).

And a hard coating layer formed under the transparent substrate.

According to an embodiment of the present invention, there is provided a touch panel including the transparent conductive film.

The siloxane compound in the high refractive index layer coating composition applied to the transparent conductive film according to the present invention may include a polymeric siloxane compound having a network structure formed by a sol-gel reaction and has excellent dispersibility of the metal alkoxide compound, The refractive index of the high refractive index layer formed directly on the transparent substrate can be controlled and uniformity of the surface can be ensured.

In addition, the transparent conductive film according to the present invention can perform stable index matching.

1 is a schematic cross-sectional view of a transparent conductive film according to an embodiment of the present invention.
2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention.

The inventors of the present invention completed the present invention by studying the transparent conductive film and confirming that the index matching of the transparent conductive film is excellent by incorporating the siloxane compound and the metal alkoxide compound into the composition for high refractive index layer coating.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. In the drawings, for the convenience of explanation, the thicknesses of some layers and regions are exaggerated.

Hereinafter, the formation of any structure in the "upper (or lower)" or the "upper (or lower)" of the substrate means that any structure is formed in contact with the upper surface (or lower surface) of the substrate However, the present invention is not limited to not including other configurations between the substrate and any structure formed on (or under) the substrate.

The present invention relates to a transparent substrate; A high refractive index layer formed on the transparent substrate; A low refractive index layer formed on the high refractive index layer; And a transparent conductive layer formed on the low refractive index layer, wherein the high refractive index layer comprises a composition for high refractive index layer coating comprising a siloxane compound of formula (1) and a metal alkoxide compound of formula (2)

[Chemical Formula 1]

(R1) _n- Si- (O-R2) _4-n

(2)

R3-O-M

Wherein R 1 is an alkyl group having 1 to 18 carbon atoms, a vinyl group, an allyl group, an epoxy group or an acrylic group, and R 2 and R 2 are an alkyl group having 1 to 6 carbon atoms or an acetyl group, , And M is titanium, zirconium or aluminum.

1 is a schematic cross-sectional view of a transparent conductive film according to an embodiment of the present invention.

1, a transparent conductive film 10 according to an embodiment of the present invention includes a transparent substrate 1; A high refractive index layer (2) formed on the transparent substrate (1); A low refractive layer (3) formed on the high refractive index layer (2); And a transparent conductive layer (4) formed on the low refractive layer (3).

2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention.

2, the transparent conductive film 10 according to another embodiment of the present invention includes a transparent substrate 1; A high-refraction layer (2); A low refractive layer 3; And the transparent conductive layer 4 are the same as those shown in FIG. 1 but are formed by further including a hard coating layer 5 formed on the lower portion of the transparent substrate 1.

The transparent substrate (1)

The transparent substrate 1 may be a film having excellent transparency and strength. The transparent substrate 1 is preferably a film made of at least one selected from the group consisting of PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), PES (polyethersulfone), PC (Polycarbonate), PP (polypropylene) and norbornene resins. It is not limited. Further, the transparent substrate 1 may be in the form of a single film or a laminated film.

High-refraction layer (2)

The high refractive index layer 2 is formed on the transparent substrate 1 and is formed directly on the transparent substrate 1 without forming a hard coating layer on the transparent substrate 1. The high refractive index layer 2 constituting the transparent conductive film 10 has a higher refractive index than that of the low refractive index layer 3. The difference in refractive index between the transparent substrate 1 and the transparent substrate 1 is small, While reducing the interference phenomenon with respect to the transmitted light of the touch panel screen display and increasing the conductivity.

The high refractive index layer (2) is formed of a high refractive index layer coating composition comprising a siloxane compound of formula (1) and a metal alkoxide compound of formula (2)

[Chemical Formula 1]

(R1) _n- Si- (O-R2) _4-n

(2)

R3-O-M

Wherein R 1 is an alkyl group having 1 to 18 carbon atoms, a vinyl group, an allyl group, an epoxy group or an acrylic group, and R 2 and R 2 are an alkyl group having 1 to 6 carbon atoms or an acetyl group, , And M is titanium, zirconium or aluminum.

The siloxane compound is represented by the following formula (1).

[Chemical Formula 1]

(R1) _n- Si- (O-R2) _4-n

Wherein R1 is an alkyl group having 1 to 18 carbon atoms, a vinyl group, an allyl group, an epoxy group or an acrylic group, R2 is an alkyl group having 1 to 6 carbon atoms or an acetyl group, and n is an integer satisfying 0 <n <4.

The siloxane compound is a compound having a low physical refractive index, and includes an alkoxysilane compound; And a functional silane compound substituted with at least one selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an acryl group, a glycidyl group, and combinations thereof.

That is, the inclusion of the siloxane compound in the composition for high refractive index layer coating has an effect of controlling the refractive index and improving the reaction stability.

The siloxane compound may include a polymeric siloxane compound having a network structure formed by the sol-gel reaction of the siloxane compound.

The sol-gel reaction is carried out by coagulation and condensation of colloidal particles in a sol which is obtained by hydrolysis or dehydration condensation of silica fine particles obtained by flame hydrolysis of a sol having dispersed therein several hundreds of tens of nanometers of colloidal particles dispersed in a liquid Refers to a reaction in which the fluidity of the sol is lost to form a gel of the porous body.

That is, it is possible to form a polymeric silonic acid compound by the sol-gel reaction of the siloxane compound, for example, by mixing the siloxane compound of the formula 1 with water and ethanol to synthesize silica sol, To convert it into a liquid phase network to prepare a polymeric siloxane compound of inorganic network structure.

The polymer siloxane compound preferably has a weight average molecular weight of 3,000 to 55,000, but is not limited thereto. By maintaining the weight average molecular weight of the polymeric siloxane compound, it is advantageous in terms of thickness control during the formation of the thin film, and the effect of uniformly maintaining the surface roughness can be easily realized.

The polymer siloxane compound is preferably 0.1 part by weight to 100 parts by weight based on 100 parts by weight of the siloxane compound, but is not limited thereto. The polymer siloxane compound affects the refractive index of the composition for forming an undercoat layer. By including the polymer siloxane compound in the above range, the refractive index can be easily controlled.

Conventionally, in the case of a high refractive index layer, refractive index is controlled by forming a coating layer mainly using high refractive index nanoparticles. However, there is a problem due to low dispersion of the nanoparticles and nonuniformity of the coating surface, The refractive index of the high refractive index layer can be controlled and the surface uniformity can be secured by including a metal alkoxide compound having excellent dispersibility in place of the nanoparticles in the high refractive index layer coating composition.

That is, by including the metal alkoxide compound in the composition for high-refractive-index layer coating, it is possible to secure a high-refractive-index composition having a uniform physical property having a low manufacturing cost.

The metal alkoxide compound is represented by the following formula (2).

(2)

R3-O-M

R3 is an alkyl or acetyl group having 1 to 6 carbon atoms, and M is titanium, zirconium or aluminum.

The metal alkoxide compound may be titanium tetraisopropoxide or zirconium (IV) butoxide.

The metal alkoxide compound is preferably 50 parts by weight to 1000 parts by weight based on 100 parts by weight of the siloxane compound, but is not limited thereto. When the amount of the metal alkoxide compound is less than 50 parts by weight, a refractive index sufficient to satisfy the high refractive index function is not secured. When the amount of the metal alkoxide compound exceeds 1000 parts by weight, the reaction stability and storage stability Is low.

The refractive index of the high refractive index layer 2 is preferably from 1.58 to 1.74, but is not limited thereto. At this time, when the refractive index of the high refractive index layer 2 is less than 1.58, the pattern concealability of the transparent conductive layer 4 is deteriorated, which is disadvantageous in index matching. When the refractive index of the high refractive index layer 2 exceeds 1.74, There is a problem that the degree of formation of the coating film of the coating film 2 is lowered.

The thickness of the high refractive index layer 2 is preferably 200 nm to 1.0 탆, but is not limited thereto. If the thickness of the high refractive index layer 2 is less than 200 nm, it is difficult to ensure the thickness uniformity of the coating layer due to the formation of the high refractive index layer 2. When the thickness of the high refractive index layer 2 exceeds 1.0 탆 , There is a problem that the curability for the formation of the coating film is lowered and the curability of the high refractive index layer 2 after the curing becomes weak.

That is, even if the high refractive index layer 2 is directly formed on the transparent substrate 1 without forming the hard coating layer separately on the transparent substrate 1 by keeping the thickness of the high refractive index layer 2 within the above range, The surface can be adjusted and the uniformity of the surface can be ensured.

Low refraction layer (3)

The low refractive index layer (3) is formed on the high refractive index layer (2).

The low refractive index layer 3 constituting the transparent conductive film 10 has a lower refractive index than that of the high refractive index layer 2 and the difference in refractive index between the transparent conductive layer 4 and the transparent conductive layer 4 is small, Thereby lowering the interference phenomenon with respect to the transmitted light of the touch panel screen display and increasing the conductivity.

The refractive index of the low refractive layer 3 is preferably 1.40 to 1.45, but is not limited thereto. When the refractive index of the low refractive layer 3 is less than 1.40, it is difficult to adjust the thickness for ensuring the index matching property. When the refractive index of the low refractive layer 3 exceeds 1.45, There is a problem in that the pattern hiding ability of the recording medium is deteriorated and the index matching is disadvantageous.

The thickness of the low refractive index layer 3 is preferably 10 nm to 30 nm, but is not limited thereto. When the thickness of the low refraction layer 3 is less than 10 nm, it is difficult to ensure uniformity of the thickness of the coating layer due to the formation of the low refraction layer 3. When the thickness of the low refraction layer 3 is 30 nm The transmittance is increased and the index matching is disadvantageously disadvantageous.

Transparency Conductive layer (4)

The transparent conductive layer 4 is formed on the low refractive index layer 3.

The transparent conductive layer 4 may be formed of ITO (Indium Tin Oxide) or FTO (Fluorine-doped Tin Oxide).

The thickness of the transparent conductive layer 4 is preferably 5 nm to 50 nm, but is not limited thereto. At this time, the thickness of the transparent conductive layer 4 is kept within the above range, which is advantageous for ensuring the visibility and electrical conductivity of the transparent conductive film 10.

The siloxane compound in the high refractive index layer coating composition applied to the transparent conductive film 10 may include a polymeric siloxane compound having a network structure formed by a sol-gel reaction and has excellent dispersibility of a metal alkoxide compound. 1, the refractive index of the high refractive index layer 2 formed directly on the transparent substrate 1 can be adjusted without forming a hard coating layer on the upper surface, and uniformity of the surface can be ensured.

In addition, the transparent conductive film 10 can perform stable index matching.

Hard coating layer (5)

A hard coating layer 5 formed on the lower surface of the transparent substrate 1 may be further included. The hard coating layer 5 may be made of an acrylic resin, a urethane acrylic resin, or the like. The thickness of the hard coat layer 5 is preferably 0.5 탆 to 2.0 탆, but is not limited thereto. At this time, by keeping the thickness of the hard coat layer 5 within the above range, the scratch of the transparent substrate 1 can be effectively prevented.

According to an embodiment of the present invention, there is provided a touch panel including the transparent conductive film (10).

The transparent conductive film 10 is useful as a top substrate and / or a bottom substrate of a touch panel, particularly a resistive touch panel. In the resistive touch panel, a pair of transparent conductive substrates are oriented and arranged with a spacer interposed therebetween. When the upper panel is pressed with a finger or a pen, the transparent conductive base material is bent and the conductive thin film So that the position is detected.

The touch panel may be used in a display device such as an LCD, a PDP, an LED, an OLED or an E-paper.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the following examples.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the following examples.

[ Example ]

Example  One

50 mol of tetra-ethoxyorthosilicate (TEOS) was mixed with water and ethanol at a molar ratio of 1: 2: 2 relative to 1 mol of trimethoxy (methyl) silane, and 0.1 mol of nitric acid was added thereto. To form a polymeric siloxane compound having a refractive index of 1.43. 1000 parts by weight of a metal alkoxide compound was added to a solution containing a polymeric siloxane compound in an amount of 100 parts by weight of the polymeric siloxane compound, and further reacted for 24 hours to form a high refractive index composition. The formed high refractive index composition was diluted with ethyl alcohol (EtOH) to prepare a high refractive index layer coating composition having a total solid content of 18%.

The composition for the high refractive index layer coating was coated on top of the PET film and then cured in an oven at 150 ° C for 1 minute to form a high refractive index layer. At this time, the refractive index of the high-refractive-index layer was measured at 1.736 (measuring device: Prism Coupler (SPA-4000, the wavelength of laser at 532 nm)) and the thickness was 493 nm.

The composition for coating a low refractive index layer was coated on top of the high refractive index layer and then cured in an oven at 150 캜 for one minute to form a low refractive index layer. At this time, the refractive index of the low refraction layer was measured to be 1.44 and the thickness was 23 to 25 nm.

An ITO layer was formed to a thickness of 20 nm on the low refraction layer by a sputtering method and the ITO layer was patterned to prepare a transparent conductive film.

Example  2 to 6

A composition for forming a high-refractive-index layer was prepared from a transparent conductive film in the same manner as in Example 1, except that the metal alkoxide compound was added as shown in Table 1 below.

metal Alkoxide  compound Polymer Siloxane  Compound 100 Weight portion  Contrast metal Alkoxide  The content of the compound Example  One Titanium tetraisopropoxide 1000 Example  2 Titanium tetraisopropoxide 800 Example  3 Titanium tetraisopropoxide 600 Example  4 Titanium tetraisopropoxide 400 Example  5 Titanium tetraisopropoxide 200 Example  6 Zirconium (IV) butoxide 1000

Table 2 below shows the results of evaluating the index matching of the ITO layer etching pattern on the transparent conductive film according to Examples 1 to 6. [

The index matching was evaluated by whether or not the etching pattern of the ITO layer was visually confirmed. The index was marked according to the degree of excellent index matching (very excellent: 3, excellent: 2, medium: 1) Is denoted by X.

Refractive index  ( at  532 nm ) thickness ( nm ) index matching  Evaluation results Example  One 1.736 493 2 Example  2 1.708 502 2 Example  3 1.682 513 3 Example  4 1.648 498 2 Example  5 1.602 506 2 Example  6 1.682 508 3

As shown in Table 2, it was confirmed that the transparent conductive films according to Examples 1 to 6 were easy to visually recognize the ITO etching pattern, and thus the index matching was excellent.

Further, by maintaining the thickness of the high refractive index layer in the transparent conductive film according to Examples 1 to 6, it is possible to control the refractive index even if the high refractive index layer is directly formed on the transparent substrate without forming a hard coating layer separately on the transparent substrate So that uniformity of the surface can be ensured.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (14)

Transparent substrate;
A high refractive index layer formed on the transparent substrate;
A low refractive index layer formed on the high refractive index layer; And
And a transparent conductive layer formed on the low refraction layer,
Wherein the high refractive index layer comprises a transparent conductive film formed from a composition for high refractive index layer coating comprising a siloxane compound of Formula 1 and a metal alkoxide compound of Formula 2:
[Chemical Formula 1]
(R1) _n- Si- (O-R2) _4-n
(2)
R3-OM
Wherein R 1 is an alkyl group having 1 to 18 carbon atoms, a vinyl group, an allyl group, an epoxy group or an acrylic group, and R 2 and R 2 are an alkyl group having 1 to 6 carbon atoms or an acetyl group, , And M is titanium, zirconium or aluminum.
The method according to claim 1,
The siloxane compound
Alkoxysilane compounds; And
A functional silane compound substituted with at least one member selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an acryl group, a glycidyl group, and combinations thereof
Transparent conductive film.
The method according to claim 1,
The siloxane compound includes a polymeric siloxane compound having a network structure formed by the sol-gel reaction of the siloxane compound
Transparent conductive film.
The method of claim 3,
Wherein the polymer siloxane compound has a weight average molecular weight of 3,000 to 55,000
Transparent conductive film.
The method of claim 3,
The polymeric siloxane compound is used in an amount of 0.1 to 100 parts by weight per 100 parts by weight of the siloxane compound
Transparent conductive film.
The method according to claim 1,
The metal alkoxide compound may be used in an amount of 50 to 1000 parts by weight per 100 parts by weight of the siloxane compound
Transparent conductive film.
The method according to claim 1,
The transparent substrate may be a film made of at least one selected from the group consisting of PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), PES (polyethersulfone), PC (Polycarbonate), PP
Transparent conductive film.
The method according to claim 1,
The refractive index of the high refractive index layer is 1.58 to 1.74
Transparent conductive film.
The method according to claim 1,
The thickness of the high refractive index layer is in the range of 200 nm to 1.0 [
Transparent conductive film.
The method according to claim 1,
The refractive index of the low refractive layer is 1.40 to 1.45
Transparent conductive film.
The method according to claim 1,
The thickness of the low refraction layer is preferably from 10 nm to 30 nm
Transparent conductive film.
The method according to claim 1,
The transparent conductive layer may be formed of ITO (Indium Tin Oxide) or FTO (Fluorine-doped Tin Oxide).
Transparent conductive film.
The method according to claim 1,
Further comprising a hard coat layer formed on a lower portion of the transparent substrate
Transparent conductive film.
A transparent conductive film comprising the transparent conductive film according to any one of claims 1 to 13
Touch panel.

Images