KR102524456B1 - Method of preparing window film laminate - Google Patents

Abstract

The present invention relates to a method for manufacturing a window film laminate, and more particularly, to a method comprising: forming a non-display portion pattern on one surface of a window film; Forming a phase difference compensation layer on the base film; Forming a polarizer coating layer on the phase difference compensation layer; and bonding the non-display area pattern and the polarizer coating layer to face each other with an adhesive having a thickness greater than or equal to the height of the non-display area pattern between the window film on which the non-display area light-shielding pattern is formed and the polarizer coating layer. It relates to a method for manufacturing a window film laminate capable of realizing color in a non-display area without deterioration.

Description

Manufacturing method of window film laminate {METHOD OF PREPARING WINDOW FILM LAMINATE}

The present invention relates to a method for manufacturing a window film laminate.

Demand for a display device with further improved performance while being miniaturized and lightweight is explosively increasing, centering on semiconductor technology that has been rapidly developing in recent years.

In accordance with the trend of informatization, electronic displays for visually conveying information are appearing in various forms, and with the recent development of mobile communication, the development of displays requiring portability is strongly emerging.

Such a display device has been changed from a cathode ray tube (LCD) to a liquid crystal display (LCD), a plasma display panel (PDP), an organic electro luminescence display (OLED), and the like.

In particular, a liquid crystal display (LCD) or an organic electro luminescence display (OLED) consumes less power than the existing cathode ray tube system, can be made smaller, lighter, and thinner, and does not emit harmful electromagnetic waves. There are advantages. Due to this, it has been attracting attention as a next-generation high-tech display, and is currently used in almost all information processing devices that require a display device. In addition, due to the recent spread of smartphones, the use of a touch screen panel combining such a display device with a touch sensor is rapidly increasing.

As shown in FIG. 1, taking a mobile phone as an example, a window substrate is disposed on the outermost surface, and the window substrate is divided into a display portion that displays an image on the front surface and accepts touch input as necessary, and a non-display portion surrounding the display portion. Separated.

A non-display portion shielding pattern is formed in the non-display portion to function to hide opaque conductive wiring patterns and various circuits, and a mobile phone maker's trademark or logo is printed as needed. Conventionally, since the main purpose of the non-display portion is to conceal wiring or circuitry, it is common to form a black layer.

An example of a laminate structure under a conventional window substrate is shown in FIG. 2 . Referring to FIG. 2 , a polarizer 11 and a retardation compensation layer 12 are sequentially stacked on one surface of the window substrate 10 along the direction in which the user (viewer's side) looks, and then the non-display area light blocking pattern ( 13) is formed.

In this structure, there is no problem when the non-display area light-shielding pattern 13 is black, but since the polarizer 11 is located in front of the non-display area light-shielding pattern 13 when viewed from the viewer's side, implementation of colors other than black is almost impossible. impossible. Recently, since a demand for implementing various colors in a non-display unit is increasing, it is difficult for such a structure to meet such a demand.

In order to solve the above problem, the structure shown in FIG. 3 has been proposed. Referring to FIG. 3 , a window substrate 20, a non-display area blocking pattern 23, a polarizer 21, and a retardation compensation layer 22 are sequentially disposed from the viewing side. In the structure of FIG. 3, since the polarizer 21 is located behind the non-display area light-shielding pattern 23 when viewed from the viewing side, the color of the non-display area light-shielding pattern 23 can be visually recognized without distortion, so that light-shielding patterns of various colors can be obtained. It is easy to implement.

However, in the case of the structure of FIG. 3 , the polarizing plate 21 is stacked on the non-display blocking pattern 23, and the polarizing plate 21 maintains a flat state due to the step difference between the window substrate 20 and the non-display blocking pattern 23. It is difficult to maintain, and thus may cause structural and electrical defects in structures to be laminated thereafter.

Korean Patent Publication No. 2013-0044101 has proposed a method for manufacturing a window film for a display using a double injection and in-mold labeling method, but the manufacturing process is complicated and industrialization is difficult.

Korean Patent Publication No. 2013-0044101

An object of the present invention is to provide a method for manufacturing a window film laminate in which various colors of a light-shielding pattern of a non-display unit can be recognized.

In addition, an object of the present invention is to provide a method for manufacturing a window film laminate capable of bonding a polarizing plate and other members without affecting the level difference between the window film and the light-shielding pattern of the non-display area.

In addition, an object of the present invention is to provide a method for manufacturing a window film laminate suitable for a flexible display by implementing thin film and free from breakage of a polarizer film.

1. (A) forming a non-display area light blocking pattern on one side of a window film;

(B) (B-1) forming a phase difference compensation layer on the base film;

(B-2) forming a polarizer coating layer on the phase difference compensation layer; and

(C) bonding the non-display area shading pattern and the polarizer coating layer face to face with an adhesive having a thickness greater than or equal to the height of the non-display area shading pattern between one side of the window film on which the non-display area shading pattern is formed and the polarizer coating layer; A method for manufacturing a window film laminate comprising:

2. The method of manufacturing a window film laminate according to 1 above, wherein the non-display area blocking pattern is formed of a plurality of layers.

3. In the above 1, wherein the base film is a retardation film, the method of manufacturing a laminate.

4. The method of manufacturing a window film laminate according to 1 above, wherein the retardation compensation layer is a retardation compensation coating layer in which a photocurable liquid crystal compound is cured by light irradiation.

5. The method of manufacturing a window film laminate according to 1 above, wherein in step (B-2), the polarizer coating layer is formed on the alignment layer after forming the alignment layer on the retardation compensation layer.

6. The method of manufacturing a window film laminate according to 5 above, wherein the alignment layer is cured by light irradiation.

7. The method of manufacturing a window film laminate according to 1 above, wherein the polarizer coating layer is formed by including a liquid crystal compound that aligns in the alignment direction of the alignment layer.

8. The method of manufacturing a window film laminate according to 1 above, further comprising forming a first overcoat layer on the retardation compensation layer and forming the alignment layer on the overcoat layer.

9. The method of manufacturing a window film laminate according to 1 above, further comprising forming a second overcoat layer on the polarizer coating layer.

10. The method of manufacturing a window film laminate according to 1 above, wherein any one selected from the group consisting of a barrier layer, a touch sensor layer, and a display panel is bonded to the opposite surface of the base film on which the retardation compensation layer is formed.

In the manufacturing method of the window film laminate of the present invention, since the polarizer coating layer is disposed behind the non-display area shading pattern when viewed from the viewer side, when a non-display area shading pattern realized with various colors is formed, the color is not distorted. can be admitted

In addition, in the manufacturing method of the window film laminate of the present invention, since the adhesive is interposed between the window film and the polarizer coating layer of the non-display area shading pattern to a thickness equal to or greater than the height of the window film and the non-display area shading pattern, there is a level difference due to the non-display area shading pattern. The polarizer and other members can be laminated without affecting.

In addition, since the polarizer is implemented in the form of a coating layer, the manufacturing method of the window film laminate of the present invention is free from the problem of cracking or dimensional change of the conventional film-type polarizer, and can be preferably applied to a flexible display because it can be implemented as a thin film. In addition, when the retardation compensation layer is also implemented in the form of a coating layer, it is more preferable to implement a thin film.

In addition, in the method of manufacturing a window film laminate according to the present invention, when an overcoat layer is provided between the polarizer coating layer and the adhesive agent, deterioration of the function of the polarizer coating layer can be prevented.

In addition, in the method of manufacturing a window film laminate according to the present invention, when an overcoat layer is provided between the retardation compensation layer and the alignment layer, the retardation compensation layer can be prevented from deteriorating.

1 is a perspective view schematically illustrating a display unit and a non-display unit of a mobile phone.
2 and 3 are schematic cross-sectional views of a conventional window film laminate, respectively.
Figure 4 is a view schematically showing an example of the manufacturing method of the present invention.
5 to 7 are schematic cross-sectional views of one embodiment of a window film laminate manufactured according to the manufacturing method of the present invention, respectively.

The present invention comprises the steps of forming a non-display portion pattern on one side of a window film; Forming a phase difference compensation layer on the base film; Forming a polarizer coating layer on the phase difference compensation layer; and bonding the non-display area pattern and the polarizer coating layer to face each other with an adhesive having a thickness greater than or equal to the height of the non-display area pattern between the window film on which the non-display area light-shielding pattern is formed and the polarizer coating layer. It relates to a method for manufacturing a window film laminate capable of realizing color in a non-display area without deterioration.

Referring to the following drawings, the embodiment of the present invention will be described in more detail. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the contents of the above-described invention, so the present invention is described in such drawings should not be construed as limited to

4 schematically shows an embodiment of a method for manufacturing a window film laminate according to the present invention.

First, a non-display area light blocking pattern 200 is formed on one surface of the window film 100 (A).

The window film 100 constitutes the outermost surface of the image display device, protects the device, displays an image, and accepts a user's touch input as needed.

For the window film 100 according to the present invention, materials used in the related art may be employed without particular limitation, and a flexible substrate may be preferably used.

Specific examples of the window film 100 include glass, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), and polyethyelenen napthalate (PEN). , polyethylene terephthalate (PET, polyethyelene terepthalate), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC, polycarbonate), cellulose triacetate (TAC), Cellulose acetate propionate (CAP) and the like may be used, and in the case of glass, it is preferable to use tempered glass.

Glass strengthening treatment may be performed through etching strengthening, thermal strengthening, chemical strengthening, and the like. Etching strengthening is a method of strengthening by giving small curves to the glass surface, and thermal strengthening is a method of increasing the compressive strength by solidifying the glass surface than the inside. It is a method of strengthening by spraying cold refrigerant and rapidly cooling it. Chemical strengthening is a method of strengthening glass by generating compressive stress on the surface by replacing small ions (Na ions) with large ions (K ions).

Among the above examples, the flexible window film can be applied to a polymer substrate, and can be applied to a glass material as long as it is 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 non-display portion blocking pattern 200 may be formed according to a conventional method in the art. For example, ink for forming the non-display portion light blocking pattern 200 may be applied to a predetermined area of the window film 100 by screen printing, offset printing, photolithography, or the like, and then dried or cured.

The non-display portion light blocking pattern 200 may be formed of a plurality of layers to implement various colors, three-dimensional effects, and the like, if necessary. In this case, each layer may have the same color or different colors, and may be formed of the same or different materials.

Next, the retardation compensation layer 400 and the polarizer coating layer 520 are sequentially disposed on the base film 300 (B).

Specifically, first, the retardation compensation layer 400 is formed on the base film 300 (B-1).

The base film 300 is not particularly limited as long as it is transparent and can support the retardation compensation layer 400, and preferably, a film excellent in transparency, mechanical strength, thermal stability, moisture barrier, etc. may be used. Specific examples include polyester-based resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulosic resins such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based resin; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrenic resins such as polystyrene and acrylonitrile-styrene copolymer; polyolefin-based resins such as polyethylene, polypropylene, polyolefins having a cyclo-based or norbornene structure, and ethylene-propylene copolymers; vinyl chloride-based resins; amide resins such as nylon and aromatic polyamide; imide-based resins; polyethersulfone-based resins; sulfone-based resins; polyether ether ketone-based resins; sulfurized polyphenylene-based resins; vinyl alcohol-based resin; vinylidene chloride-based resins; vinyl butyral-based resins; allylate-based resins; polyoxymethylene-based resin; A film made of a thermoplastic resin such as an epoxy resin may be used, and a film made of a blend of the thermoplastic resin may also be used. In addition, a film made of a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylurethane, epoxy, or silicone may be used.

As another embodiment of the present invention, an optical functional film may be used as the base film 300 . For example, it is a retardation film that can be used together with the retardation compensation layer 400 to adjust the overall phase difference or color of the window film laminate according to the present invention, or, as a specific example, the base film 300 is a positive C plate. can Theoretically, the positive C plate means the case where the refractive index ratio (Nz) is -∞, but in the present invention, the positive C plate is determined up to the case where the refractive index ratio (Nz) is -6 or less.

The retardation compensating layer 400 functions to adjust transmitted light to have a required retardation value, and may be, for example, a 4-minute wave plate that forms circularly polarized light together with a polarizer coating layer. The retardation compensation layer 400 may be provided in the form of a film or a coating, and a retardation compensation coating layer formed in the form of a coating is advantageous for thinning.

For example, when the retardation compensation layer 400 is formed as a coating layer, it may be formed by applying a photocurable coating composition containing a photocurable liquid crystal compound and curing it by irradiating light.

As the photocurable liquid crystal compound, specific retardation compensation performance of the retardation compensation layer 400 may be adjusted by selecting a specific photocurable liquid crystal compound according to required performance.

Next, a polarizer coating layer 520 is formed on the retardation compensation layer 400 (B-2).

Typically, the polarizer coating layer 520 requires an alignment layer. Therefore, after forming an alignment layer on a separate substrate, forming a polarizer coating layer 520 on the alignment layer, and then transferring only the polarizer coating layer 520 onto the retardation compensation layer 400, the retardation compensation layer A polarizer coating layer 520 may be bonded on 400 .

As another embodiment of the present invention, in step (B-2), an alignment layer 510 may be formed on the retardation compensation layer 400 and a polarizer coating layer 520 may be formed on the alignment layer 510. In this case, the laminated structure is as shown in FIG. 6 .

The alignment layer 510 is a layer formed for this purpose because the photocurable liquid crystal compound forming the polarizer coating layer 520 needs to be aligned in a certain direction in order to exhibit polarization performance.

A method known in the art may be applied to the alignment layer 510 without limitation. For example, it may be formed by rubbing after forming a polymer layer, or it may be formed by irradiating light after applying a photocurable composition containing a compound for forming an alignment layer, and preferably, a photocurable composition may be used. there is. Examples of the alignment layer-forming compound include polyimide-based, polyamide-based resins, cinnamate-based, and polyamic acid-based, but are not limited thereto.

After the alignment layer 510 is formed, a polarizer coating layer 520 is formed.

The polarizer coating layer 520 may be formed using a liquid crystal compound capable of forming a polarizer coating layer known in the art. For example, a photocurable liquid crystal compound may be used, but is not limited thereto. Although the present invention is not limited thereto, the liquid crystal compound generally exists in the form of a polymer in which a dichroic dye is dispersed. The liquid crystal compound may be selected from a wide range, regardless of a low molecular liquid crystal compound or a high molecular liquid crystal compound, depending on the intended use or manufacturing method. In addition, although the molecular shape of a liquid crystal compound is a rod, it may be a disc shape. For example, a discotic liquid crystal compound exhibiting discotic nematic liquid crystal may also be used. Examples of the liquid crystal phase of the liquid crystal compound layer before immobilization include a nematic phase, a twisted nematic phase, a cholesteric phase, a hybrid nematic phase, a hybrid twisted nematic phase, a discotic nematic phase, and a smectic phase.

The polarization difference coating layer 520 may be formed by applying a composition including a photocurable compound for forming a polarizer coating layer on the alignment layer 510 and curing the composition by irradiating light.

According to the present invention, since the retardation compensation layer 400, the alignment layer 510, and the polarizer coating layer 520 may be sequentially formed on the base film 300 by a coating method, the retardation compensation layer and the polarizer layer are integrated. An optical functional film can be prepared. In addition, since all of the optical functional layers are formed as coating layers, it is advantageous for thinning, and thus can be usefully used in flexible displays.

Next, between one surface of the window film 100 on which the non-display area light-shielding pattern 200 is formed and the polarizer coating layer 520, an adhesive agent 600 is interposed to a thickness equal to or greater than the height of the non-display area light-shielding pattern 200, and The non-display portion light blocking pattern 200 and the polarizer coating layer 520 are bonded to face each other (C).

In the present invention, the adhesive refers to a pressure-sensitive adhesive or adhesive. The adhesive agent 600 according to the present invention is interposed so as to have a thickness greater than or equal to the height of the non-display area light-shielding pattern 200 .

The window film laminate according to the present invention has a thin film structure in which the retardation compensation layer 400, the alignment layer 510, and the polarizer coating layer 520 are all formed as coating layers, so that there is no step difference due to the light-shielding pattern 200 in the non-display area. When this occurs, even if the formation of the polarizer coating layer 520 and the retardation compensation layer 400 itself is difficult or formed, polarization performance and retardation compensation performance may be greatly deteriorated.

However, the adhesive agent 600 according to the present invention has a thickness greater than or equal to the height of the non-display area light-shielding pattern 200, so that the base film 300 in which the optical functional layers according to the present invention including the polarizer coating layer 520 are stacked Even if they are bonded, these optical functional layers are not affected by the level difference between the window film 100 and the non-display area light-shielding pattern 200 .

Since the expected effect is exhibited when the thickness of the adhesive 600 is equal to or greater than the height of the non-display area light-shielding pattern 200, the upper limit is not particularly limited, and is appropriately determined according to the total thickness of the window film laminate required. can be regulated.

As the adhesive 600, any adhesive 600 known in the art may be used without particular limitation, and for example, a heat-curable or photo-curable adhesive may be used, and preferably a photo-curable adhesive may be used. .

In the present invention, a first overcoat layer 710 may be further provided on the retardation compensation layer 400 as needed. When the retardation compensation layer 400 according to the present invention is formed of a photocurable liquid crystal compound and the alignment layer 510 is also formed of a photocurable compound, the liquid crystal compound forming the retardation compensation layer 400 and the alignment layer 510 are formed. The optical properties of the compounds to be formed may be different. In this case, there is a concern that the optical characteristics of the retardation compensation layer 400 formed first may be changed by the light irradiated during the formation of the alignment layer 510 thereafter. Therefore, in this case, after forming the first overcoat layer 710 on the retardation compensation layer 400 as shown in FIG. 7 and then forming the alignment layer on the first overcoat layer 710, these optical characteristics are change can be prevented.

In the present invention, a second overcoat layer 720 may be further provided on the polarizer coating layer 520 if necessary. According to the foregoing, the polarizer coating layer 520 may directly contact the adhesive agent 600. In this case, the liquid crystal compound forming the polarizer coating layer 520 may change polarization characteristics under the influence of the adhesive component. Accordingly, as shown in FIG. 7 , in this case, if the second overcoat layer 720 is formed on the polarizer coating layer 520 , the change in polarization characteristics can be prevented.

In the present invention, "first" and "second" are only used to distinguish different components and have no other meaning.

In the present invention, components known in the art to which a window film laminate can be introduced may be bonded to the opposite surface of the base film 300 on which the retardation compensation layer 400 is formed. For example, a barrier layer, a touch sensor layer, a display panel, and the like may be bonded using an adhesive or adhesive.

The barrier layer may be used alone in the form of a film or may be used in the form of a coating layer on a film. The barrier coating may be a hard coating or an organic/inorganic hybrid coating, and may be formed of a single layer or a plurality of layers.

The window film laminate of the present invention can be bonded to a touch sensor layer or a display panel to be usefully used as a window film of a touch screen panel or a window film of a display device.

10, 20: window substrate
11, 21: polarizer 12, 22: retardation compensation layer
100: window film
13, 23, 200: non-display area light blocking pattern
300: base film 400: phase difference compensation layer
510: alignment layer 520: polarizer coating layer
600: sticky adhesive
710: first overcoat layer 720: second overcoat layer

Claims (10)

(A) forming a non-display area blocking pattern on one surface of the window film;
(B) (B-1) forming a phase difference compensation layer on the base film;
(B-2) forming a polarizer coating layer on the phase difference compensation layer;
(B-3) forming a second overcoat layer in direct contact on the polarizer coating layer to form a laminate including the retardation compensation layer, the polarizer coating layer, and the second overcoat layer sequentially stacked from the base film step; and
(C) between one surface of the window film on which the non-display area shading pattern is formed and the second overcoating layer of the laminate, a thickness equal to or greater than the height of the non-display area shading pattern is interposed with an adhesive agent, and the non-display area shading pattern and the second overcoating layer are interposed therebetween. A method of manufacturing a window film laminate comprising the step of bonding the overcoating layer to face and contact the adhesive agent.
The method of claim 1 , wherein the non-display area light blocking pattern is formed of a plurality of layers.
The method of claim 1, wherein the base film is a retardation film.
The method of claim 1, wherein the retardation compensation layer is a retardation compensation coating layer in which a photocurable liquid crystal compound is cured by light irradiation.
The method of claim 1 , wherein in step (B-2), the polarizer coating layer is formed on the alignment layer after forming the alignment layer on the retardation compensation layer.
The method of claim 5 , wherein the alignment layer is cured by light irradiation.
The method of claim 5 , wherein the polarizer coating layer is formed by including a liquid crystal compound aligned in an alignment direction of the alignment layer.
The method of claim 5 , further comprising forming a first overcoat layer on the retardation compensation layer and forming the alignment layer on the first overcoat layer.
delete The method according to claim 1, wherein any one selected from the group consisting of a barrier layer, a touch sensor layer, and a display panel is bonded to the opposite surface of the retardation compensation layer formation surface of the base film.

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