KR101849875B1 - Protective film for curved display screen and Method of preparing the same - Google Patents

Abstract

The present invention relates to a protective film for a display having a curved edge and a manufacturing method thereof, and can adhere to and protect a curved unit of a display. The protective film for a curved surface display of the present invention is also protected with tempered glass on the curved surface unit to enhance safety of the curved unit of a display. In addition, since the tempered glass, a first film layer, a second film layer, and an adhesive layer are formed to have the same thickness up to a front unit and the curved unit, the present invention can prevent refractive index difference depending on a position. Furthermore, the protective film of the present invention can be applied to a plurality of displays having various curvature radii because a space or a gap generated by difference between the curvature radius of the tempered glass and the curvature radius of the display is filled with liquid curable resin adhesive.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a protective film for a display having a curved edge, and a protective film for a curved display screen,

The present invention relates to a protective film for a display having a curved surface and a method for manufacturing the protective film. More particularly, the present invention relates to a protective film for a display which can be in close contact with a curved portion of a display to protect the protective film.

Recently, a smartphone in the form of a curved edge formed in the outer area of the liquid crystal is being released among smart phones. In the case of the front display unit having such a curved surface portion, if the conventional general protective film is attached, the protective film can not be completely adhered to the curved surface portion, resulting in lifting phenomenon. It is only released in a form that is cut and attached to a corresponding size, so that the entire front display unit, that is, the curved surface unit can not be completely protected.

In order to solve this problem, there is a method in which the foaming is performed by heating and pressing so that the rim portion of the plate-shaped protective film corresponds to the curved portion. However, even if the protective film of a general synthetic resin material is subjected to foaming, The edges of the protective film tend to fall off the curved surface portion. Or in the case of a film made of a synthetic resin, there is a problem that durability is low and bubbles are easily generated because the curved surface portion is stretched when forming.

In order to solve such a problem, a protective film using tempered glass has been used. For example, in Korean Patent No. 10-1483672, an air wall portion and a support portion are provided to prevent a gap between a tempered glass and a curved surface of a display from being lifted. However, it is not easy to attach the supporting part of the Korean Patent No. 10-1483672 to the outer edge of the reinforced glass, and when the radius of curvature of the display is not the same, it is difficult to adjust the thickness of the supporting part, There is still air in the air wall portion, which may cause air inflow into the gap between the PET layer and the silicon layer. In addition, in Korean Patent No. 10-1483672, layers constituting the liquid crystal protection plate for protecting the display front part and the curved surface part are different from each other in refractive index of light. As a result, the user can visually recognize You may feel uncomfortable.

The present invention provides a protective film for a display which can be brought into close contact with a curved portion when a curved portion is formed on the outer surface of a display of a smart phone.

The present invention is to provide a protective film for a display which can be protected by a tempered glass as well as a curved surface as well as a display front part.

The present invention provides a protective film for a display which can alleviate the visual difference between the front surface and the curved surface portion by constituting constituent layers for protecting the display front part and the curved surface part.

The present invention provides a protective film for a display applicable to each of a plurality of displays having various curvature radii without deforming the product structure or shape.

One aspect of the present invention is

A step of forming a lower layer (A) comprising the step of adhering a light-transmitting first film layer (20) having a pressure-sensitive adhesive layer (10) formed on a mold (P) having a curved surface (curvature radius R1)

Forming an upper layer (B), which comprises forming a light-transmitting second film layer (50) on which a layer of an adhesive (40) is formed on a lower surface of a tempered glass (30) whose curvature is a curved surface (radius of curvature R);

Applying a curable resin (60) on the first film layer (20) of the lower layer;

Bonding the upper layer (A) to the curable resin (60) layer;

A curing step of irradiating heat, ultraviolet rays or light; And

And a step of removing the mold (P).

In another aspect,

A protective film for covering a curved portion (radius of curvature R1) formed on the outer surface of a liquid crystal of a smartphone, the protective film comprising a lower layer (A) and an upper layer (B)

The lower layer (A)

A pressure-sensitive adhesive layer (10) having an outer curved surface portion (radius of curvature R1);

And a first film layer (20) attached on the pressure-sensitive adhesive layer (10) and having an outer curved surface portion (radius of curvature R1)

The upper layer (B)

A tempered glass (30) having an outer curved surface portion (radius of curvature R);

And a second film layer (50) adhered to a bottom surface of the tempered glass including an outer curved surface portion, wherein the protective film comprises a resin adhesive layer (60) cured by heat or ultraviolet rays between the upper layer and the lower layer, Relates to a curved surface display protective film which is filled with spaces or gaps generated by a difference between an outer curvature radius R1 of the lower layer and an outer curvature radius R of the upper layer.

The curved display protective film of the present invention is also protected by tempered glass on the curved surface portion to enhance the safety of the display curved portion. In addition, since the tempered glass, the first film layer, the second film layer, and the adhesive layer are formed to have the same thickness up to the front portion and the curved portion, the present invention can prevent the refractive index difference depending on the position.

In addition, the protective film of the present invention can be applied to a plurality of displays having various curvature radii because the space or gap generated by the difference between the curvature radius of the tempered glass and the curvature radius of the display is filled with the liquid curable resin adhesive.

1 shows a method of manufacturing a curved display protective film of the present invention.
2 shows a curved display protective film of the present invention.
Fig. 3 shows a case where the adhesive is bonded using an OCA adhesive without using a liquid resin adhesive.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention of the user, the operator, or the custom. Therefore, the definition should be based on the contents throughout this specification.

Fig. 1 shows a method of manufacturing a curved display protective film of the present invention. Fig. 2 shows a curved display protective film of the present invention. Fig. 3 shows a curved display protective film FIG.

Referring to FIG. 1, the present invention includes a lower layer (A) forming step, an upper layer forming step (B), a liquid resin applying step, a lapping step, a hardening step and a mold removing step.

The step of forming the lower layer (A) includes the step of attaching a light-transmissive first film layer (20) having a pressure-sensitive adhesive layer (10) formed on a mold (P) having a curved surface (curvature radius R1).

First, a mold P having the same shape as a smartphone (particularly, a front surface and a curved surface) to be used with the protective film of the present invention is manufactured. Therefore, the curved surface of the mold P has the same radius of curvature R1 as that of the smartphone in which the protective film is used. On the other hand, even with the same product (EX. Galaxy 7 edge), not all of the millions of smartphones have the same radius of curvature (R1) and the error (curvature radii R1-1, R1-2, R1-3 ....) Lt; / RTI > Here, the radius of curvature R1 can be understood as an average radius of curvature such as curvature radii R1-1, R1-2, R1-3 .... and the like.

The mold P1 (radius of curvature R1-1), P2 (radius of curvature R1-2), and the like are manufactured for each of the curvature radii R1-1, R1-2, R1-3 ...., Protective films capable of covering the molds P1 and P2 can be prepared and provided, respectively.

The pressure-sensitive adhesive layer 10 is made of a material having an adhesive property such as silicone, thereby allowing the protective film of the present invention to be detachably attached to the surface of the liquid crystal (C1) of the smartphone as desired by a user.

The pressure-sensitive adhesive layer 10 is formed on the lower surface of the first film layer 20, and the lower layer forming step attaches the first film layer 20 attached to the lower surface of the pressure-sensitive adhesive layer on the mold.

Meanwhile, in the present invention, the lower layer (A) may be formed by attaching the pressure sensitive adhesive layer (10) first on the mold and then attaching the first film layer (20) on the pressure sensitive adhesive layer.

The first film layer 20 may use a resin film of a highly transparent light transmitting material, and preferably a flexible PET (Polyethyene Terephthalate) having excellent heat resistance and corrosion resistance.

The step of forming the upper layer B includes the step of forming a light transmissive second film layer 50 on which the adhesive 40 is formed on the lower surface of the tempered glass 30 whose curvature is a curved surface (radius of curvature R).

The upper layer forming step first provides the tempered glass 30 with a curved surface (radius of curvature R). The radius of curvature R of the tempered glass may be the same as the average radius of curvature R1 of the mold or may have a predetermined error. On the other hand, even if the radius of curvature R of the tempered glass is the same as the average radius of curvature R1 of the mold, the curvature radii R1-1, R1-2, R1-3, A difference with the radius R1 may occur.

The thickness of the tempered glass may range from 0.1 to 1 mm, preferably from 0.18 to 0.4 mm.

The method of the present invention attaches a second film layer (50) having an adhesive layer (40) formed on a tempered glass (30). That is, the adhesive layer 40 may be formed on the lower surface of the second film layer 50.

On the other hand, in the method of the present invention, the adhesive layer 40 may be first attached to the tempered glass, and then the second film layer may be adhered onto the adhesive layer.

The adhesive may be a known optical transparent adhesive (OCA).

The second film layer 50 may be made of a resin film of a highly transparent light transmitting material, and preferably, PET (Polyethyene Terephthalate) having excellent heat resistance and corrosion resistance can be used.

The second film layer 50 may be made of the same material as the first film layer.

The first film layer and the second film layer may have a thickness of 30 to 150 mu m, preferably 50 to 100 mu m.

The thickness of the pressure-sensitive adhesive layer 10 may range from 20 to 50 탆, preferably from 30 to 35 탆.

The thickness of the adhesive layer 40 may range from 30 to 100 占 퐉, preferably 50 to 100 占 퐉.

The first film layer and the second film layer may be all those whose edges are formed or not formed. However, in the present invention, even if a flat film that is not formed is used, the curved shape can be maintained by the curable resin.

The applying step is a step of applying the curable resin 60 onto the first film layer 20 of the lower layer.

The curable resin 60 may be heat, ultraviolet ray or photo-curable resin. As the curable resin, a known transparent curable resin may be used. For example, a commercially available UV curable resin may be used as the curable resin. For example, the curable resin may be a mixture of a (meth) acrylate monomer or a (meth) acrylate oligomer having an epoxy group and an initiator in a dispersant (ethanol, acetone, ethylene glycol or the like). Examples of the (meth) acrylate monomer include 2 (2 ethoxyethoxy) ethyl acrylate, 2-phenoxyethyl acrylate, 1,3-butylene glycol diacrylate, 1,4 butanediol dimethacrylate , Diethylene glycol diacrylate, propoxylated glyceryl triacrylate, propoxylated trimethylol propane triacrylate, trimethylol propane triacrylate, and the like.

As the (meth) acrylate oligomer, a bisphenol-A epoxy acrylate oligomer, a novolak type epoxy acrylate oligomer, and a bisphenol-F epoxy acrylate oligomer may be used.

As the initiator, benzophenone (benzophenone, 1-hydroxy-cyclohexyl-phenyl-ketone, etc.) may be used.

The lapping step is a step of lapping the upper layer (B) on the lower layer (A) coated with the curable resin (60). The lapping step may cover the lower layer with the upper layer and press the upper layer with a roller or the like.

The lapping step is a step of filling a space or a gap between the lower layer A and the upper layer B, which is caused by the difference between the radius of curvature of the mold P and the radius of curvature of the tempered glass 30, with the liquid curing resin .

When the radius of curvature of the lower layer (which is the radius of curvature R1 of the mold) and the radius of curvature of the upper layer (which is the radius of curvature R of the tempered glass frame) are different from each other, for example, When the radius of curvature is larger than R1, a gap is formed between the upper layer and the lower layer depending on the difference in radius of curvature when a commonly used OCA adhesive (indicated by S) is used.

However, in the case of the present invention, the liquid cured resin flows to the curved portion during the lapping step to fill the gap. At this time, an auxiliary film (not shown) may be temporarily adhered so as to prevent the cured resin from falling off to the outside, and then removed after curing. The auxiliary film has fine holes, so that the air remaining in the gap can be discharged to the outside.

The lapping step may maintain a standby state for several seconds to several minutes so that the cured resin fills the gap.

The curing step is a step of applying heat or ultraviolet rays for a predetermined time. The present invention can separate and remove the mold (P) after curing is completed.

Meanwhile, as described above, the present invention can perform the above-described method using the mold P 1 having a radius of curvature exceeding the error range of the mold P 1 and a predetermined range.

2 is a curved display protective film of the present invention produced by the above method. The protective film of the present invention comprises an upper layer (B) containing tempered glass and a lower layer (A) in contact with the liquid crystal display part of the smartphone.

As described above, the protective film of the present invention can cover the curved portion (curvature radius R1) formed on the outer surface of the liquid crystal of the smartphone.

The lower layer A comprises a pressure-sensitive adhesive layer 10 having an outer curved surface portion (radius of curvature R1) and a first film layer 20 attached on the pressure-sensitive adhesive layer 10 and having an outer curved surface portion (curvature radius R1) Respectively.

The upper layer B includes a tempered glass 30 having an outer curved surface portion (radius of curvature R) and a second film layer 50 adhered to the lower surface of the tempered glass including an outer curved surface portion.

The protective film of the present invention includes a resin adhesive layer 60 cured by heat or ultraviolet rays between the first film layer 20 and the second film layer 50.

The resin adhesive layer is cured by filling spaces or gaps between the first film layer 20 and the second film layer 50 which are generated by the difference between the outer radius of curvature R1 of the lower layer and the outer radius of curvature R of the upper layer.

The resin adhesive layer 60 is formed over the entire area between the first film layer 20 and the second film layer 50.

The resin adhesive layer 60 includes a flat part a and a curved part b, and the thickness of the curved part may be different from the thickness of the flat part a.

For example, when the reinforced glass curvature radius R is larger than the outer curvature radius R1 of the lower layer, the thickness of the curved surface portion b becomes thicker as the distance from the flat portion a is increased.

For example, when the tempered glass curvature radius R is smaller than the outer curvature radius R1 of the lower layer, the thickness of the curved surface portion b may become thinner as the distance from the flat portion a is increased.

The above-mentioned contents can be referred to for the pressure-sensitive adhesive layer 10, the first film 20, the tempered glass 30, the adhesive layer 40, the second film 50 and the cured resin layer 60.

The protective film of the present invention may further include a protective layer (not shown) on the lower surface of the pressure sensitive adhesive layer (10). The user can use the protective film after attaching the protective film to the smartphone display after removing the protective layer.

As described above, the curved surface display protective film of the present invention can fill spaces or gaps caused by the difference in radius of curvature with the liquid curable resin adhesive to prevent the floating phenomenon occurring in the curved surface portion. In addition, since the tempered glass, the first film layer, the second film layer, and the adhesive layer are formed to have substantially the same thickness from the front portion to the curved portion, the protective film of the present invention can prevent a difference in refractive index depending on the position.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. Therefore, the scope of the present invention is not limited to the above-described embodiments, but should be construed to include various embodiments within the scope of the claims and equivalents thereof.

Claims (3)

A step of forming a lower layer (A) comprising the step of adhering a light-transmitting first film layer (20) having a pressure-sensitive adhesive layer (10) formed on a mold (P) having a curved surface (curvature radius R1)
Forming an upper layer (B), which comprises forming a light-transmitting second film layer (50) on which a layer of an adhesive (40) is formed on a lower surface of a tempered glass (30) whose curvature is a curved surface (radius of curvature R);
Applying a curable resin (60) on the first film layer (20) of the lower layer (A);
Bonding the upper layer (B) on the lower layer (A) coated with the curable resin (60);
A curing step of applying heat or ultraviolet rays; And
Removing the mold (P);
≪ / RTI > The method according to claim 1, wherein the lapping step is performed in a space between the first film layer (20) and the second film layer (50), which is caused by a difference between a radius of curvature of the mold (P) And filling the gap with the curable resin in the liquid phase. A protective film for covering a curved portion (radius of curvature R1) formed on the outer surface of a liquid crystal of a smartphone, the protective film comprising a lower layer (A) and an upper layer (B)
The lower layer (A)
A pressure-sensitive adhesive layer (10) having an outer curved surface portion (radius of curvature R1);
And a first film layer (20) attached on the pressure-sensitive adhesive layer (10) and having an outer curved surface portion (radius of curvature R1)
The upper layer (B)
A tempered glass (30) having an outer curved surface portion (radius of curvature R);
And a second film layer (50) adhered to the bottom surface of the tempered glass including the outer curved surface portion,
The protective film includes a resin adhesive layer 60 cured by heat or ultraviolet rays between the upper layer and the lower layer, and the resin adhesive layer is formed by a difference between the outer radius of curvature R1 of the lower layer and the outer radius of curvature R of the upper layer Wherein the first film layer (20) and the second film layer (50) are cured by filling spaces or gaps between the first film layer (20) and the second film layer (50).

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