Conductive transparent film

Abstract

The present application relates to a conductive transparent film. The conductive transparent film comprises an undercoating layer, an anti-crack buffer layer, and a conductive layer. The conductive transparent film may have not only excellent mechanical strength, but also have a fast response speed when applied to a touch panel.

Claims

1. A conductive transparent film comprising a conductive layer; an undercoating layer; and an anti-crack buffer layer, wherein after bending said conductive transparent film having a size of 1 mm1 mm with vernier calipers, a value of crack density is 80 cracks/mm.sup.2 or less, which is measured by dividing the combined length value of the entire crack generated in the conductive layer by 100 m.

2. The conductive transparent film according to claim 1, wherein said anti-crack buffer layer is positioned between the conductive layer and the undercoating layer.

3. The conductive transparent film according to claim 2, wherein said anti-crack buffer layer comprises a metal oxide.

4. The conductive transparent film according to claim 3, wherein said metal oxide is NbO.sub.x (1X2.5).

5. The conductive transparent film according to claim 3, wherein said anti-crack buffer layer has a thickness of 0.1 nm to 20 nm.

6. The conductive transparent film according to claim 1, wherein said conductive layer comprises a transparent conductive oxide.

7. The conductive transparent film according to claim 6, wherein said conductive layer has a thickness of 100 nm or less.

8. The conductive transparent film according to claim 7, wherein said conductive layer has a surface resistance value in a range of 20 /sq to 95 /sq.

9. The conductive transparent film according to claim 6, wherein said conductive layer has a surface resistance value in a range of 20 /sq to 300 /sq.

10. The conductive transparent film according to claim 1, wherein said undercoating layer comprises an organic substance, and said organic substance comprises at least one selected from an acrylic resin, a urethane resin, a thiourethane resin, a melamine resin, an alkyd resin, a siloxane polymer and an organosilane compound represented by Formula 2 below:
(R.sup.1).sub.mSiX.sub.(4-m)[Formula 2] in Formula 2 above, R.sup.1 may be the same or different from each other and is alkyl having 1 to 12 carbon atoms, alkenyl, alkynyl, aryl, arylalkyl, alkylaryl, arylalkenyl, alkenylaryl, arylalkynyl, alkynylaryl, halogen, substituted amino, amide, aldehyde, keto, alkylcarbonyl, carboxy, mercapto, cyano, hydroxy, alkoxy having 1 to 12 carbon atoms, alkoxycarbonyl having 1 to 12 carbon atoms, sulfonic acid, phosphoric acid, acryloxy, methacryloxy, epoxy or a vinyl group, X may be the same or different from each other and is hydrogen, halogen, alkoxy having 1 to 12 carbon atoms, acyloxy, alkylcarbonyl, alkoxycarbonyl, or N(R.sup.2).sub.2 (where R.sup.2 is H, or alkyl having 1 to 12 carbon atoms), where oxygen or NR.sup.2 (where R.sup.2 is H, or alkyl having 1 to 12 carbon atoms) may also be inserted between a radical R.sup.1 and Si to form (R.sup.1).sub.mOSiX.sub.(4-m) or (R.sup.1).sub.mNR.sup.2SiX.sub.(4-m), and m is an integer of 1 to 3.

11. The conductive transparent film according to claim 10, wherein said undercoating layer has a thickness of 150 nm or less.

12. The conductive transparent film according to claim 1, having a light transmittance of 75% or more.

13. A method for manufacturing the conductive transparent film according to claim 1, comprising a step of sequentially providing an anti-crack buffer layer and a conductive layer on an undercoating layer.

14. A touch panel comprising the conductive transparent film according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a cross-section of a conductive transparent film according to one example of the present application.

(2) FIG. 2 is images photographed cracks generated on the surface of an experimental specimen. Specifically, FIG. 2a is an image photographed the surface of Example 1; FIG. 2b is an image photographed the surface of Example 2; and FIG. 2c is an image photographed the surface of Comparative Example 1.

DETAILED DESCRIPTION OF THE INVENTION

(3) Hereinafter, the present application will be described in detail through Examples. However, the scope of protection of the present application is not limited by Examples described below.

(4) The physical properties of Examples and Comparative Examples below were each evaluated in the following manner.

(5) Physical Property Evaluation Method

(6) <Surface Resistance>

(7) After heat treating the conductive transparent film prepared in Examples and Comparative Examples at a temperature condition of 130 C. for 1 hour, the surface resistance (/) of the ITO conductive layer was measured through 4-probe measurement (Loresta EP MCP-T360).

(8) <Transmittance>

(9) After heat treating the conductive transparent film prepared in Examples and Comparative Examples at a temperature condition of 130 C. for 1 hour, the transmittance was measured using Hazemeter (HM-150, Murakami Color Research Loboratory) and UV-VIS-NIRSPECTROPHOTOMETER (UV-3600, SHIMADZU).

(10) <Mechanical Properties>

(11) Bend Length at the Time of Crack Occurrence

(12) A protective film was attached to the conductive transparent film in the film form prepared in Examples and Comparative Examples, and the ITO layer was crystallized by heat treatment. Then, the film was cut into a size of 1 mm1 mm to prepare a specimen. When the specimen was placed in a bending state with vernier calipers so that the crystallized ITO layer was located on the inner side and maintained for 30 seconds, the bend length at the time when cracks were generated in the ITO layer was measured.

(13) Crack Density

(14) In the ITO layer that cracks were generated, the length of 100 m was regarded as one crack, and the lengths of the entire crack generated in the specimen were combined, and then the combined value was divided by 100 m. As a result, cracks having different lengths and numbers were quantified.

Example 1

(15) A solution containing a condensable organosilane compound (methyltrimethoxysilane) was coated on a transparent PET base material having a thickness of 50 m and thermally cured to form an undercoating layer having a thickness of 40 nm. An anti-crack buffer layer comprising niobium oxide (NbO.sub.x) was deposited on the undercoating layer to a thickness of 1 nm by using a sputtering technique, while targeting niobium (Nb) and supplying a mixed gas of argon and oxygen to the deposition equipment. Similarly, an indium oxide layer comprising SnO.sub.2 was formed to a thickness of 21.3 nm on the anti-crack buffer layer using the sputtering technique to prepare a conductive transparent film. The constitution and physical properties of the prepared film are as shown in Tables 1 and 2, respectively.

Examples 2 to 5

(16) As shown in the following Table 1, a film was prepared in the same manner as in Example 1, except for the thickness of the anti-crack buffer layer and the surface resistance value. The physical properties of the prepared film are as shown in Table 2.

Comparative Example 1

(17) As shown in Table 1 below, a film was prepared in the same manner as in Example 1, except that the ITO layer was directly formed on the undercoating layer, without preparing the anti-crack buffer layer. The physical properties of the prepared film are as shown in Table 2.

(18) TABLE-US-00001 TABLE 1 Thickness of ITO Composition of Anti-crack Thickness Anti-crack Buffer Layer (nm) Buffer Layer (nm) Example 1 21.3 NbO.sub.1.5 1 Example 2 21.3 NbO.sub.1.5 1.5 Example 3 21.3 NbO.sub.1.5 2 Example 4 21.3 NbO.sub.1.5 3 Example 5 21.3 NbO.sub.1.5 5 Comparative 21.3 Example 1

(19) TABLE-US-00002 TABLE 2 Mechanical Property Surface Optical Bend Length at Crack Resistance Property the Time of Density Value Transmittance Crack Occurrence (number/ (/) (%) (nm) mm.sup.2) Example 1 92 91.6 16 31.8 Example 2 94 91.2 16 48.6 Example 3 93 90.8 16 46.9 Example 4 94 90.5 16 77.2 Example 5 93 89.8 17 12.4 Comparative 98 91.6 16 84.3 Example 1