KR101139803B1 - Transparent Both Faces Adhesive Tape For Touch Panel Or PDP Filter - Google Patents

Abstract

The present invention relates to a transparent double-sided adhesive tape, and more particularly, in a transparent double-sided adhesive tape having a transparent pressure-sensitive adhesive layer formed on both sides of the transparent substrate, the transparent pressure-sensitive adhesive layer is methacrylate-based functional properties containing hydroxy The present invention relates to a transparent double-sided adhesive tape for a touch panel or a PDP filter comprising an acrylic polymer including a monomer.

According to the present invention, there is no change in the intrinsic properties of the transparent conductive film even after a period of time after adhesion to the transparent conductive film (ITO film) made of a transparent metal layer, the total light transmittance and haze value in the interlaminar adhesion and visible wavelength range There is an effect of providing a transparent double-sided adhesive tape for a touch panel or a PDP filter which is excellent in overcoming foaming and warping problems after fixing.

Touch screen, touch panel, adhesive tape, support, high transparency, ITO film, mobile phone, PDA, navigation, PDP

Description

Transparent Both Faces Adhesive Tape For Touch Panel Or PDP Filter}

The present invention relates to a transparent double-sided adhesive tape, and more particularly, there is no change in intrinsic properties of the transparent conductive film even after elapse of time after being attached to a transparent conductive film (ITO film) that is a transparent metal layer, The present invention relates to a transparent double-sided adhesive tape for a touch panel or a PDP filter which is excellent in total light transmittance and haze value in the visible wavelength range and overcomes the foaming and warping problems after fixing.

With the rapid increase of mobile touch phones with touch screens, the touch screen market is expanding to a wide range of applications, riding on a huge growth rate. Touch screens have been mainly applied to industrial applications such as ATMs and kiosks, but the market size is rapidly growing due to personal mobiles such as mobile phones, PDAs and navigation.

The touch screen panel basically consists of a touch panel, a controller, a driver, and software. The touch panel is composed of a top plate (film) and a bottom plate (film or glass) on which a transparent conductive film (ITO: Indium Tin Oxide) is deposited, determines the presence or absence of a contact input, detects input coordinates, and transmits a signal to a controller. In charge of the function. The touch screen panel may include a resistive method, a capacitive method, an ultrasonic surface wave method, and an infrared method according to an implementation method of the touch panel. Currently, various structures such as film-OCA-film, film-OCA-PC, and film-OCA-glass are used for resistive film (4-wire resistance) and capacitive method as mobile touch phones. The resistive film is a double layer structure of film and glass coated with a conductive transparent electrode capable of flowing current, and a pattern of transparent electrode is printed on both the film and glass. When touched, an electric signal is generated to recognize the position.The capacitive type is a single glass coated with a conductive transparent electrode rather than a double layer structure like a resistive touch panel. The driving method is strong in durability, short in reaction time, and excellent in permeability, and the application of these is increasing in recent years.

In the capacitive touch panel, an ITO coating layer of ITO-PET is positioned outside to recognize external static electricity. ITO-PET is coated with ITO (Indium Tin Oxide) on PET film, which is a base film. When ITO is in contact with acidic products, the surface is oxidized and loses its unique function. Unlike resistive touch panels, ITO-PET Since it is not used, a higher durability is required, and there is a need to develop a high performance transparent double-sided adhesive tape containing a component that corrodes the conductive transparent electrode.

Therefore, in order to apply the pressure-sensitive adhesive to the capacitive touch panel, the pressure-sensitive adhesive should be transparent, have low thermal deformation, and increase stress relaxation.In particular, when attached to a plastic plate, excellent interlayer adhesion is required and foaming after fixing should not occur. This warping problem and the problem of discoloration should be solved.

In order to solve the problems of the prior art as described above, the present invention has no change in the inherent properties of the transparent conductive film film even after a period of time after being attached to the transparent conductive film (ITO film) is a transparent metal layer, interlayer adhesion and visibility An object of the present invention is to provide a transparent double-sided adhesive tape for a touch panel or a PDP filter that has excellent total light transmittance and haze value in the light wavelength range and overcomes the foaming and warping problems after fixing.

These and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides a transparent double-sided pressure-sensitive adhesive tape in which a transparent pressure-sensitive adhesive layer is formed on both sides of the transparent substrate, wherein the transparent pressure-sensitive adhesive layer includes a methacrylate-based functional monomer containing hydroxy. Provided is a transparent double-sided adhesive tape for a touch panel or a PDP filter, which is made of a polymerized acrylic polymer.

As described above, according to the present invention, there is no change in the inherent properties of the transparent conductive film film even after a period of time after being attached to the transparent conductive film (ITO film) of the transparent metal layer, interlayer adhesion and visible wavelength range In the excellent light transmittance and haze value, there is an effect of providing a transparent double-sided adhesive tape for a touch panel or PDP filter that overcomes the foaming and warping problems after fixing.

Hereinafter, the present invention will be described in detail.

The transparent double-sided pressure-sensitive adhesive tape for a touch panel or a PDP filter of the present invention is a transparent double-sided pressure-sensitive adhesive tape in which a transparent pressure-sensitive adhesive layer is formed on both sides of a transparent base material, wherein the transparent pressure-sensitive adhesive layer has a methacrylate-based functional property containing hydroxy. It is characterized by consisting of a polymerized acrylic polymer including a monomer.

Acrylic polymer

First, the acrylic polymer according to the present invention will be described in detail.

The acrylic polymer forms a transparent double-sided adhesive tape, wherein the acrylic polymer is copolymerizable with at least one acrylic monomer selected from alkyl (meth) acrylates having 4 to 17 carbon atoms, the acrylic monomer, and methyl methacrylate or vinyl. It is composed of a monomer selected from acrylates, methacrylate-based functional monomers containing hydroxy and a crosslinking agent.

The acrylic monomer of the present invention is an acrylic ester having a sticky property with a low glass transition temperature in terms of durability, and preferably at least one selected from 2-ethylhexyl acrylate, n-butyl acrylate, iso-oxyl acrylate, and the like. Use

The monomer copolymerizable with the acrylic monomer of the present invention uses one or more selected from methyl methacrylate, vinyl acrylate, etc., and uses 10 to 15 parts by weight based on 100 parts by weight of the acrylic monomer, within this range copolymerization. This is excellent.

The hydroxy methacrylate functional monomer containing the hydroxy of the present invention is an important component to be applied to the capacitive touch panel, specifically, it is preferable to use 2-hydroxyethyl methacrylate, and 100 weight of the acrylic monomer 3 to 10 parts by weight per part is used, and within this range, the pressure-sensitive adhesive has excellent curability, and in particular, when applied to a capacitive touch panel, effects such as adhesion, transmittance, haze, and foam resistance are excellent.

The crosslinking agent of the present invention uses one or more selected from melamine compounds, epoxy compounds, isocyanate compounds and the like, 0.03 to 0.5 parts by weight based on 100 parts by weight of the acrylic monomer, and more preferably 0.15 to 0.35 parts by weight. . Within this range, substrate adhesion and cohesion are excellent, yellowing does not occur, and various physical properties are possible.

The method for producing the acrylic polymer of the present invention is by a method of solution polymerization, emulsion polymerization, suspension polymerization, dispersion polymerization, and the like, and more preferably by a solution polymerization method in which the monomer and the solvent undergo a one-component radical reaction.

Clear Double Sided Adhesive Tape & Touch Panel

The transparent double-coated adhesive tape is coated with the acrylic polymer using a release-treated film, more specifically, a film on which the silicone release agent is surface-treated, more specifically, the silicone release force may be based on the light peeling side as 1. When using a film that is treated with a silicone release liquid that is 3 to 5 times heavier peeling. As a coating method, the slot die, gravure roll, comma roll, kiss roll, di-roll, bar, etc. can be coated by the coating method, but the thick film coating of 50 ㎛ is possible and the slot die with precise thickness control ( Slot Die) coating method is effective.

Applying the transparent double-sided adhesive tape to produce a capacitive touch panel, the method is by a conventional method used in the art.

In addition, the transparent double-sided adhesive tape may be applied to manufacture a resistive touch panel and a PDP filter.

1 schematically shows a transparent double-sided adhesive tape of the present invention.

2 schematically shows a capacitive touch panel including a transparent double-sided adhesive tape of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the physical properties of the present invention are not limited to the following Examples.

Manufacturing example  1 to 3

Acrylic polymers were prepared in the content ratios shown in Table 1 below.

Classification (unit: parts by weight) Preparation Example 1 Production Example 2 Production Example 3 Acrylic monomer BA 75 75 75 2-EHA 25 25 25 Co-monomer MMA 2.5 2.5 2.5 VA 10 10 10 Functional monomer 2-HEMA 7.5 - - BMA - 7.5 - AA - - 7.5 Initiator BPO 0.25 0.25 0.25 solvent EAc 100 100 100 Weight average molecular weight of the polymer 650,000 630,000 700,000 BA: n-butyl acrylate
2-EHA: 2-ethylhexyl acrylate
MMA: Methyl Methacrylate
VA: Vinyl Acrylate
2-HEMA: 2-hydroxyethyl methacrylate
BMA: Butyl methacrylate
AA: acrylic acid
ICN: Isocyanate
BP0: Benzoyl Peroxide
EAc: Ethyl Acetate

Example  1 to 3 and Comparative example  1 to 2

In the preparation examples 1 to 3 of Table 1, an acrylic pressure-sensitive adhesive was prepared including a crosslinking agent (based on 100 parts by weight of acrylic monomer) of the content shown in Table 2 below.

division
(Unit: weight part) Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Polymer class Preparation Example 1 Preparation Example 1 Preparation Example 1 Production Example 2 Production Example 3 Crosslinking agent
(Isocyanate) 0.03 0.25 0.05 0.25 0.25

Test Example

1. Number average molecular weight was measured by the following specimen, column, equipment and the results are shown in Table 3 below.

Specimen: 0.2% / 10 μl (dissolved in THF solution)

Column: Micro styragel

Equipment: Agilent 1100S

2. Adhesion was measured by the following specimens, conditions, equipment and the results are shown in Table 3 below.

Specimen: PET film (25 um) / Adhesive tape

Condition: 180 ℃ peel strength (KSA D1107)

-Equipment: Universal Testing Machine (Shimadzu, AG-IS)

-Deposition surface: ITO film

Evaluation: Peel Strength

3. Transparency (transmittance and haze) were measured by the following specimens and equipment, and the results are shown in Table 3 below.

Specimen: Slide glass / Adhesive tape

Equipment: Minolta, CM-3600D

Evaluation: Measured as transmittance = total light transmittance / / haze = diffusion transmittance (%) / total light transmittance (%).

4. The reliability of product warpage was measured under the following conditions and the results are shown in Table 3 below.

-Test Specimen Fabrication (Size: 10 cm × 5 cm)

-Specimen type: PET film (125 um) / adhesive tape / PC (0.1T)

Condition: 80 ℃ × 500 hours (oven) / 60 ℃ × 90%: 500 hours (constant temperature and humidity)

-Items: foaming (bubble formation after lamination), lifting (film lifting), curl (film bending)

Observation: Visual observation

-Evaluation: Good-bubble / lifting: None / Curl: 0.5 mm or less from the ground

Poor-bubble / lifting: Occurrence / Curl: 0.5 mm or more from the ground

5. The oxidation test was measured by the following measurement method and the results are shown in Table 3 below.

Purpose: A test is carried out to see how the adhesive affects the oxidation of the ITO film.

-How to measure

-Laminating inorganic adhesive tape on ITO PET

-Condition: 60 ℃ × 90%: 10 days (constant temperature and humidity)

-Equipment: Surface Resistance Meter (HIOKI 3540 mΩ HITESTER)

-Evaluation: Change less than 10% from good to early / Bad more than 10% from early

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Adhesion (N / 10 mm) 5.5 4.7 3.0 4.0 5.0 Transmittance (%) 97 96 94 97 96 Haze (%) 0.3 0.4 0.6 0.3 0.4 Anti-foaming / lifting Good Good Good Good Bad warp Good Good Good Bad Good Oxidation test Good Good Good Bad Bad Number average molecular weight (Mv) 660,000 750,000 800,000 700,000 900,000

The high-transparent non-support double-sided adhesive tape using the acrylic polymer of the present invention (Examples 1 to 3) was excellent in adhesive force, transmittance, and haze, and it was confirmed that the bending problem was improved, and the oxidation test was good.

1 shows a transparent double-sided adhesive tape of the present invention.

Figure 2 shows a capacitive touch panel including a transparent double-sided adhesive tape of the present invention.

* Description of Major Symbols in Drawings *

10: plastic layer or glass layer 20: transparent double-sided adhesive tape layer

30: ITO PET layer 40: protective film layer

100: capacitive touch panel

Claims (6)

delete delete delete delete The transparent double-sided adhesive tape formed with a transparent pressure-sensitive adhesive layer made of an acrylic polymer on both sides of the transparent substrate, wherein the acrylic polymer a) 100 parts by weight of at least one acrylic monomer selected from alkyl (meth) acrylates having 4 to 17 carbon atoms; b) 10 to 15 parts by weight of a monomer copolymerizable with the acrylic monomer and selected from methyl methacrylate or vinyl acrylate; c) 3 to 10 parts by weight of 2-hydroxyethyl methacrylate as a hydroxy methacrylate functional monomer containing hydroxy; And d) 0.03 to 0.5 parts by weight of a crosslinking agent; Capacitive touch panel, the number average molecular weight of the produced double-sided adhesive tape is 660,000 ~ 800,000. The method of claim 5, The capacitive touch panel has a structure in which a plastic layer or a glass layer, a transparent double-sided adhesive tape layer, an ITO PET layer, a transparent double-sided adhesive tape layer, an ITO PET layer, a transparent double-sided adhesive tape layer, and a protective film layer are sequentially stacked. Capacitive touch panel, characterized in that.

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