KR20140134148A - Window film combined with complex polarization plate - Google Patents

Abstract

The present invention relates to a window film combined with a complex polarization plate. More particularly, a polarization plate boned to a surface of a phase difference layer is in contact with a surface of a window film, thereby implementing a thin film structure.

Description

Composite polarizer integrated window film {WINDOW FILM COMBINED WITH COMPLEX POLARIZATION PLATE}

The present invention relates to a polarizer-integrated window film. And more particularly to a polarizing plate integral window film applicable to a flexible display.

Demand for display devices with improved performance has been explosively increasing as miniaturization and weight reduction have been made centering on semiconductor technology which has been developing rapidly in recent years.

Electronic displays for visually conveying information according to information trends are emerging in various forms. Recently, development of displays requiring portability due to development of portable communication is strongly emerged.

Such a display device has been changed from a cathode ray tube (CRT) type to a liquid crystal display (LCD), a plasma display panel (PDP), and an organic electroluminescence display (OLED). Particularly, a liquid crystal display (LCD) has advantages such as low power consumption, miniaturization, light weight and thinness compared with the conventional CRT method, and does not emit harmful electromagnetic waves. As a result, it has been attracting attention as a next-generation advanced display, and nowadays, it is used in almost all information processing apparatuses requiring a display device.

In recent years, research on flexible displays that are thinner, lighter and bendable than conventional panels using a polymer film instead of a glass substrate is actively under way.

Flexible displays can be produced in the form of plastic film LCD, organic EL, wearable display, electronic book, electronic paper, etc. The application range is also very wide, so that the display for mobile communication terminal, In addition to being thin and light, it can be applied to products which are resistant to external impacts and which require bending or various forms of display.

However, in the currently used flexible liquid crystal display, only the substrate material is replaced with the polymer film substrate from the existing glass substrate, and peripheral materials and parts necessary for the display such as the polarizer and the backlight are still used as they are in the glass substrate have.

For example, in the conventional liquid crystal display, the thickness of the polarizing plate is 200 to 400 탆, and the single thickness of the protective layer used for protecting the polarizer is 25 to 100 탆. There is a difficulty in applying to a thin card-like structure.

In order to solve this problem, Korean Unexamined Patent Publication No. 2008-0073252 discloses a technique of achieving a thin structure by removing a protective film to be in contact with a liquid crystal cell among polarizers bonded to a liquid crystal cell.

Patent Document 1: Korean Published Patent Application No. 2008-0073252

An object of the present invention is to provide a window that forms an outermost surface of a touch screen panel or an image display device integrated with a polarizing plate.

It is another object of the present invention to provide a window in which a complex polarizing plate in which a retardation layer is directly bonded to a polarizer is integrated.

It is another object of the present invention to provide a window having flexibility.

1. A polarizing plate integrated type window film in which a polarizing plate joined to one surface of the retardation layer is bonded to one surface of a window film toward the polarizing plate side.

2. The composite polarizer-integrated window film of claim 1, wherein the polarizer is a laminate having a polarizer single layer or a transparent protective film bonded to one surface of a polarizer.

3. The composite polarizer-integrated window film of claim 2, wherein the polarizer is a coating layer.

4. The composite polarizer-integrated window film of claim 2, wherein the retardation layer is a layer coated on a transparent protective film of a polarizer or a polarizer.

5. The composite polarizer-integrated window film according to item 1, wherein the bonding of the polarizing plate to the window film is made of a separate bonding layer.

6. The composite polarizer-integrated window film as in 1 above, wherein the bonding of the polarizer to the window film is made of a coating of a polarizer.

7. The composite polarizer-integrated window film as in 1 above, wherein said retardation layer is a quarter-wave plate.

8. The composite polarizer integrated window film of claim 1, wherein the window film is flexible.

9. The composite polarizer-integrated window film of claim 1, wherein the total thickness is 100 to 200 mu m.

10. A touch screen panel comprising a window film of any one of claims 1 to 9 as an outermost window substrate.

11. An image display device comprising a window film of any one of items 1 to 9 as an outermost window substrate.

12. The image display apparatus of claim 11, wherein the image display apparatus is a flexible display.

The composite window polarizer integrated window film of the present invention can achieve a thin film structure by integrating a window film and a polarizer.

Further, the composite polarizer integrated window film of the present invention can be formed as a single coating layer of a polarizer, so that a thin film structure can be achieved.

In addition, the integrated polarizing plate integrated type window film of the present invention can achieve a thin film structure because the retardation layer can have a structure directly coated on the polarizer.

In addition, the composite polarizer integrated window film of the present invention uses a flexible window film and has a thin film structure as described above, so that it can be advantageously applied to a flexible display in addition to a general display.

1 is a schematic vertical cross-sectional view of a composite polarizer integrated window film according to an embodiment of the present invention.
2 is a schematic vertical sectional view of a composite polarizer integrated window film according to another embodiment of the present invention.
3 is a schematic vertical cross-sectional view of a composite polarizer integrated window film according to another embodiment of the present invention.
4 is a schematic vertical cross-sectional view of a composite polarizer integrated window film according to another embodiment of the present invention.

The present invention relates to a composite polarizer-integrated window film capable of realizing a thin film structure by bonding a polarizing plate having a retardation layer bonded to one side thereof to one side of a window film to the polarizing plate side.

Hereinafter, the present invention will be described in detail with reference to the drawings. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. And shall not be construed as limited to such matters.

Fig. 1 schematically shows an embodiment of the composite polarizer integrated window film of the present invention. The composite polarizer integrated window film of the present invention has a window film (100), a polarizer (200), and a retardation layer (300).

The window film 100 can be used without particular limitation as long as it is a window substrate constituting the outermost surface of a touch screen panel or an image display device, and a flexible substrate can be preferably used.

Specific examples of the window film 100 include glass, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelenene napthalate (PEN) Poly (ethylene terephthalate), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC) Cellulose acetate propionate (CAP) or the like can be used. In the case of glass, it is preferable to use reinforced glass.

The strengthening treatment of the glass can be carried out through etching strengthening, heat strengthening, chemical strengthening and the like. Etching strengthening is a method of strengthening the glass surface with a small bending. Heat strengthening increases the surface fluidity by rapidly heating the surface temperature of the glass to 720 ~ 750 ℃ by increasing the compressive strength by solidifying the glass surface. And then quenched by injecting cold coolant to reinforce it. Chemical strengthening is a method of strengthening by substituting small ions (Na ions) on the glass surface with large ions (K ions) to generate compressive stress on the surface.

The flexible window film can be applied to a polymer substrate among the above-mentioned examples, and even a glass material can be applied to a flexible glass material. When the window film of the present invention is applied to a flexible display, it is preferable to use a flexible window film.

The polarizing plate 200 is bonded on the window film 100 to have an integral structure with the window film 100.

The polarizing plate 200 may be a single layer of the polarizer 210 or a laminate in which the transparent protective film 220 is bonded to one surface of the polarizer 210.

When the polarizer 200 is formed as a single layer of the polarizer 210, a polymer solution containing a polymer resin and a dichroic material may be directly coated on the window film 100 to form a coating layer.

As the polymeric resin for forming the polarizer 210 coating layer, a polyvinyl alcohol-based resin is typically used. The polyvinyl alcohol-based resin is preferably a polyvinyl alcohol-based resin obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Other monomers copolymerizable with vinyl acetate include acrylamide monomers having an unsaturated carboxylic acid type, an unsaturated sulfonic acid type, an olefin type, a vinyl ether type, and an ammonium group.

The polyvinyl alcohol-based resin may be modified or may be polyvinyl formal or polyvinyl acetal modified with, for example, aldehydes.

The polarizer layer 210 can be formed by mixing a dichroic material with such a polyvinyl alcohol-based resin and forming a film.

In another aspect of the present invention, the polarizer 210 coating layer may be formed of a crystal film polarizer layer.

The crystalline film polarizer has a special molecular crystal structure formed as a result of the crystallization of the liquid crystal phase upon application, alignment and drying of the liquid crystal on the transparent substrate. The liquid crystal phase comprises at least one organic material capable of forming a stable concentration transfer or thermotropic liquid crystal phase. The organic material comprises at least one organic compound, the formula of which is: (i) at least one ionogenic group which ensures solubility in polar solvents to obtain a concentration transferred liquid crystal phase, and And / or (ii) at least one nonionogenic group that ensures solubility in a non-polar solvent to obtain a concentration-transferred liquid crystal phase, and / or (iii) And at least one counterion that may not be present.

The optically anisotropic dichroic crystal film comprises a plurality of supramolecular complexes of one or several organic compounds. These supramolecular composites are biased in a particular manner to provide polarization and electrical conductivity of the transmitted light.

The membrane consists of rodlike supramolecules and the supramolecules comprise at least one polycyclic organic compound having a disk-shaped conjugated pi-system. The film has an overall orderly crystalline structure with intermolecular spacing of 3.4 +/- 0.3 Angstroms along its polarization axis.

The base material of the optically anisotropic dichroic crystal film is selected based on the presence of groups such as amines, phenols, ketones, and the like, which are connected to the conjugation system and are placed in the plane of the molecule, and the existence of a developed pi pairing system in the conjugation ring group. Molecules and / or molecular fragments have a flat structure. Examples of the base material are indanthrone (Vat blue 4), 1,4,5,8-perylenetetracarboxylic acid dibenzoimidazole (Vat Red 14), 3,4,9,10-perylenetetracarboxyl Quinacridone (Pigment Violet 19), etc., and derivatives thereof (or a mixture thereof) can form a stable concentration-transferred liquid crystal phase.

In an optically anisotropic dichroic crystal film, the molecular planes are parallel to each other, and the molecules form a three-dimensional crystal structure at least in the crystalline film portion. An optically anisotropic dichroic monocrystal film can be formed by optimization of the manufacturing technique. The optical axis within this single crystal is perpendicular to the molecular plane. Such a thin crystal film has a high anisotropy and exhibits a high refractive index and / or a high absorption coefficient in at least one direction.

The retardation layer 300 is bonded to the opposite surface of the polarizing plate 200 on which the window film 100 is bonded. The retardation layer 300 is bonded to the polarizer 200 to form a complex polarizer. In order to maximize the effect of the composite and thin film structures, the retarder layer 300 is preferably bonded directly to the polarizer 210.

The retardation layer 300 functions to change the phase of transmitted light. For example, it may be an optical compensation layer for magnifying a viewing angle or a quarter-wave plate (1/4? Plate) for preventing reflection. When the composite polarizer integrated window film of the present invention is used in a flexible display, it is preferably a 4-wavelength polarizer.

The retardation layer 300 may be a single coating layer or a liquid crystal layer formed on the alignment layer, and a coating layer is preferable for realizing a thin film structure.

1, when the polarizing plate 200 is a coating layer formed on the window film 100 as a single layer of the polarizer 210 and the retardation layer 300 is a single coating layer formed on the polarizing layer 210, Structure can be realized as an integrated window film.

The structure shown in Fig. 1 can enable the most effective thin film structure to be realized when the window film of the present invention is applied to a flexible display. When a flexible window film is used as the window film 100, a polymer film or a glass film as a thin film is applied, so that it can have a thin film structure than a conventional rigid and thick glass substrate. For example, a rigid glass substrate used in conventional displays may have a thickness on the order of about 500 microns, while a flexible window film may have a thickness on the order of about 150 to 50 microns. In addition, if both the polarizing plate 200 and the retardation layer 300 are formed as a single coating layer instead of a conventional film, their thicknesses can be reduced to about 1 to 5 탆 at about 50 탆, which is a conventional film form. Furthermore, since the separate bonding layer having a thickness of about 30 mu m is not required individually when formed into a coating layer, the thickness can be further reduced.

If the thickness of the window film 100, the polarizing plate 200, and the phase difference layer 300 is minimized, the thickness of the conventional window film 100 can be reduced to about 150 μm or less, or about 110 μm or so. The radius of curvature of an object ^{(E * b * h 3)} / M there is calculated by (E: modulus, b: the length, h:: thickness, M the bending moment), to the curvature of the effect of thinning the thickness of the larger It is most effective in reducing the radius. For example, if the thickness of about 660 탆 is reduced to about 110 탆, the radius of curvature becomes about 35 times smaller. Considering this aspect, it is preferable that the composite polarizer integrated window film of the present invention has a total thickness of 100 to 200 mu m.

Fig. 2 schematically shows another embodiment of the composite polarizer integrated window film of the present invention. Referring to FIG. 2, the retardation layer 300 may be bonded to the polarizing plate 200 through a separate bonding layer 400. In this case, the polarizing plate 200 may be a single layer of the polarizer 210, and in this case, the window window film 100 also preferably uses a flexible window film to realize a thin film structure.

In the present invention, the "bonding layer" includes an "adhesive layer " that completely adheres one of the layers to another layer and an" adhesive layer "

When the retardation layer 300 is in the form of a film, it can be bonded to the polarizing plate 200 through the bonding layer 400. The retardation layer 300 may be a single film or may be a film of a liquid crystal layer structure formed on an alignment film, even when the retardation layer 300 is in a film form.

Fig. 3 schematically shows another embodiment of the composite polarizer integrated window film of the present invention. FIG. 3 shows a structure in which a polarizing plate 200 to which a retardation layer 300 is bonded is bonded to a window film 100 through a bonding layer 400.

In order to realize a thin film structure, it is preferable that the polarizer 210 and the retardation layer 300 are a coating layer, and therefore, in this embodiment, a transparent protective film 220 of a polarizer is used as a base material of a coating. A composite polarizer is used in which a polarizer 210 is provided as a coating layer on one surface of the transparent protective film 220 and a retardation layer 300 is coated on the other surface of the transparent protective film 220 In this case, it is more preferable for the window window film 100 to use a flexible window film to realize the thin film structure. However, this embodiment does not exclude the case where the retardation layer 300 is a liquid crystal layer formed on an alignment film in addition to a single coating layer.

When the polarizing plate 200 to which the retardation layer 300 is bonded is bonded to the window film 100, it is preferable that the polarizing plate 20 side and the retardation layer 300 side are bonded to each other so as to face the window film. It is preferable in terms of reducing reflected light when applied to a flexible display.

As the transparent protective film 220 that can be used in the present invention, a film excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. can be used. Specific examples include polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate and polybutylene terephthalate; Cellulose-based resins such as diacetylcellulose and triacetylcellulose; Polycarbonate resin; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymer; Polyolefin resins such as polyethylene, polypropylene, cyclo- or norbornene-structured polyolefins, ethylene-propylene copolymers; Vinyl chloride resin; Amide resins such as nylon and aromatic polyamide; Imide resin; Polyether sulfone type resin; Sulfone based resin; Polyether ether ketone resin; A sulfided polyphenylene resin; Vinyl alcohol-based resin; Vinylidene chloride resins; Vinyl butyral resin; Allylate series resin; Polyoxymethylene type resin; Epoxy resin, and the like, and a film composed of the blend of the thermoplastic resin may also be used. Further, a film made of a thermosetting resin such as (meth) acrylic, urethane, acrylic urethane, epoxy, or silicone or a film made of an ultraviolet curable resin may be used.

The content of the thermoplastic resin in the polarizer transparent protective film 220 is 50 to 100% by weight, preferably 50 to 99% by weight, more preferably 60 to 98% by weight, most preferably 70 to 97% by weight good. When the content is less than 50% by weight, the inherent high transparency of the thermoplastic resin may not be sufficiently exhibited.

The polarizer transparent protective film 220 may contain one or more suitable additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment and a colorant.

Further, if necessary, the transparent protective film may be surface-treated. Examples of the surface treatment include a dry treatment such as a corona treatment and a primer treatment, a chemical treatment such as an alkali treatment including a saponification treatment, and the like.

Fig. 4 schematically shows another embodiment of the composite polarizer integrated window film of the present invention. 4 shows a structure in which the polarizing plate 200 to which the retardation layer 300 is bonded is bonded to the window film 100 through the bonding layer 400 and the retardation layer 300 is bonded to the polarizer 210 of the polarizing plate 200 It is a directly bonded structure.

In this case, the polarizer 210 may be formed of a coating layer as in the above-described embodiment, or may be in the form of a film known in the art. When the polarizer 210 is a coating layer, it may be bonded to the transparent protective film 220 without a separate adhesive layer. In the case of a film, the polarizer 210 is bonded to the transparent protective film 220 through a separate adhesive layer (not shown).

The retardation layer 300 may be a single coating layer or a liquid crystal layer formed on the alignment layer. In order to realize a thin film structure, a single coating layer is preferable. In this case, the window film 100 uses a flexible window film. More preferable.

The combined polarizing plate integrated type window film of the present invention as described above may further have a structure in which an adhesive layer and a release film are sequentially laminated on at least one side to facilitate transportation and bonding with other components.

The composite polarizer integrated window film of the present invention may be attached to a display panel known in the art to form the outermost surface of the display panel. Such displays include, but are not limited to, liquid crystal displays, OLEDs, and flexible displays.

Further, the integrated polarizer integrated window film of the present invention may further include a touch sensing electrode between the display panel and the above-described display panel to form a touch screen panel.

100: Window film 200: Polarizing plate
210: Polarizer 220: Transparent protective film
300: retardation layer 400: bonding layer

Claims (12)

Wherein a polarizing plate joined to one surface of the retardation layer is bonded to one surface of the window film toward the polarizing plate side.
The composite polarizer-integrated window film according to claim 1, wherein the polarizer is a laminate having a polarizer single layer or a transparent protective film bonded to one surface of a polarizer.
The composite polarizer-integrated window film of claim 2, wherein the polarizer is a coating layer.
The composite polarizer integrated window film of claim 2, wherein the retardation layer is a layer coated on a transparent protective film of a polarizer or a polarizer.
The composite polarizer-integrated window film according to claim 1, wherein the bonding of the polarizing plate to the window film is made of a separate bonding layer.
The composite polarizer-integrated window film according to claim 1, wherein the bonding of the polarizer to the window film is a coating of a polarizer.
The composite polarizer-integrated window film according to claim 1, wherein the retardation layer is a quarter-wave plate.
The composite polarizer integrated window film of claim 1, wherein the window film is flexible.
The composite polarizer-integrated window film according to claim 1, wherein the total thickness is 100 to 200 mu m.
A touch screen panel comprising a window film of any one of claims 1 to 9 as a window substrate of an outermost surface.
An image display apparatus comprising the window film of any one of claims 1 to 9 as an outermost window substrate.
12. The image display apparatus according to claim 11, wherein the image display apparatus is a flexible display.

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