KR101932258B1 - Protective film for display pannel of portable electronic device with curved surface and manufacturing method thereof - Google Patents

Abstract

The present invention discloses a screen protective film for a curved display panel of a mobile device and a manufacturing method thereof. A curved display panel screen protective film of a mobile device according to the present invention is characterized in that a transparent synthetic resin film of a single layer structure is formed by vacuum thermoforming at least one pair of opposing edge sides to be bent downward to one side, A hard coating layer is formed on the concave surface and the convex surface of the molded article so that concave and convex surfaces corresponding to the curved display panel are formed, and a double-sided adhesive film is formed on the hard coating layer formed on the concave surface, I have. According to this constitutional feature, since the springback phenomenon can be effectively suppressed and minimized, the molding precision and the curvature of the curved protective film can be effectively improved to improve the conformability corresponding to the surface of the curved display panel, It is possible to provide a protective film that can be attached in a more stable and firmly adhered state to the surface of the protective film. Further, since the hard coating layer is formed through a separate process after the forming process of the film raw material, The quality and productivity of the film can be expected to be improved.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel screen protective film for a mobile device such as a smart phone or a tablet PC and a method for manufacturing the screen protective film. More particularly, the present invention relates to a curved display panel screen protective film And a manufacturing method thereof.

Recently, mobile devices are pursuing diversification and differentiation of products through high performance, low price, and energy saving.

For example, in a mobile device such as a smart phone or a tablet PC, the size of a display panel due to the use of multimedia contents is widened, so that a touch screen method that utilizes the display panel itself as a keypad without a separate keypad is actively adopted.

Particularly, in the case of a new product being released recently, the display panel thickness becomes thinner and the screen gradually becomes larger, and a model designed as a curved surface with a convex edge shape is emerging as a main model.

Typically, in the case of mobile devices such as smart phones and tablet PCs, a thin, transparent protective film is attached to the surface of the display panel and attached. Accordingly, it is possible to effectively prevent scratches on the surface of the display panel due to frequent contact of the touch screen during use or small scratches caused by large and small impacts from the outside.

The display panel protective film of a mobile device as described above forms an accessory product group such as a case in which a mobile device is mounted, and in recent years, various types of functional products have been actively developed and released, It is booming with the market.

On the other hand, the protective film to be attached to the display panel of the existing mobile device includes a transparent film made of a polymer compound such as a thermoplastic resin such as polyethylene terephthalate (PET), polycarbonate (PC) or polyurethane (PU) For example, in Korean Patent Registration No. 10-1221441, there is disclosed a laminated structure comprising a surface protective layer and a main resin layer, which are laminated on one surface of a transparent film, and a protective paper for protecting the adhesive surface coated with the adhesive. And a laminating structure in which an adhesive layer is laminated.

Korean Patent Publication No. 10-1329049 discloses a protective film in which an adhesive layer and a hard coating layer are formed on a polyethylene terephthalate (PET) resin. In Korean Patent Laid-Open Publication No. 10-2014-0092873, a synthetic resin base layer Discloses a protective film in which a hard coating layer and a silicone adhesive layer are formed on both sides and a release layer is formed on the upper surface of the hard coating layer and the silicone adhesive layer, respectively.

In the conventional display panel screen protective film, the preheated film fabric is molded between the upper mold and the lower mold by a press thermal compression molding method to form a flat surface corresponding to the surface shape of the display panel or a three-dimensional shape corresponding to the curvature surface shape do.

However, in the case of the conventional display panel screen protective film, the polymer compound sheet constituting the substrate layer has a problem that the so-called springback phenomenon occurs due to the restoring force after thermocompression molding, and the accuracy of dimension and curvature degree is remarkably decreased.

Particularly, the larger the curved surface of the touch screen, the greater the error in the dimensions and the curvature of the protective film. Therefore, the protective film is peeled at the periphery of the curved display panel or the defective product .

Also, in the case of a display panel protective film of a conventional mobile device, a crack or a bending phenomenon occurs in the hard coating layer during the process of thermo-compression molding of a film fabric composed of a multilayer laminating structure including a hard coating, .

SUMMARY OF THE INVENTION The present invention has been made in view of the technical background as described above and it is an object of the present invention to solve the problems of the background art described above, It can not be said to have been publicly known to the general public before.

Korean Registered Patent No. 10-1602103 Korean Patent Publication No. 10-1329049 Korean Patent Publication No. 10-1221441 Korean Patent Publication No. 10-0982555 Korean Patent Publication No. 10-2014-0000145 Korean Patent Publication No. 10-2014-0092873

DISCLOSURE Technical Problem The present invention has been made in view of the disadvantages and problems of the display panel protective film and the manufacturing method thereof of the conventional mobile device as described above, and it is an object of the present invention to minimize the occurrence of springback phenomenon The present invention provides a screen protective film for a curved display panel of a mobile device which can improve the quality and productivity of the display by increasing the precision of molding dimensions and curvature degree through an improved process.

It is another object of the present invention to provide a screen protective film for a curved display panel of a mobile device which can efficiently improve quality and productivity by a coating process designed to prevent cracking and warping of the hard coating layer.

Another object of the present invention is to provide a screen protective film for a curved display panel of a mobile device which can be attached in a more stable and firmly adhered state by improving the accuracy of conformity corresponding to the surface of a curved display panel of a mobile device .

It is still another object of the present invention to provide a method of manufacturing a screen protective film for a curved display panel of a mobile device for achieving the above object.

According to an aspect of the present invention, there is provided a curved display panel screen protective film for a mobile device, wherein at least one pair of opposing edge portions is bent to one side of the curved surface portion, A transparent synthetic resin film having a single-layer structure in which a concave surface and a convex surface corresponding to the panel are formed; A hard coating layer formed to be laminated on concave and convex surfaces of the synthetic resin film; And a pressure-sensitive adhesive layer laminated on the hard coating layer formed on the concave surface of the synthetic resin film.

According to another aspect of the present invention, there is provided a method of manufacturing a screen protective film for a curved display panel of a mobile device, comprising: preparing a transparent synthetic resin film having a single-layer structure; And a film preliminarily heated by the preheating step is vacuum-formed by vacuum thermoforming at least one pair of opposing edges to form one side of the curved portion, A hard coating step of forming a hard coating layer on the concave surface and the convex surface of the synthetic resin film formed body, and a hard coating step of adhering the hard coating layer formed on the concave surface of the synthetic resin film molded body And a pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer.

In the curved display panel screen protective film and the method of manufacturing the same according to the present invention having the above-described structure, the synthetic resin film may be made of polyethylene terephthalate (PET) having a thickness in the range of 10 to 200 m, (PMMA), polyurethane (PU), and polycarbonate (PC).

Preferably, the hard coating layer is coated with an organic coating material, an inorganic coating material, or an organic or inorganic composite coating material in which an organic material and an inorganic material are uniformly mixed.

The double-sided pressure-sensitive adhesive film has a thickness ranging from 5 to 70 and a pressure-sensitive adhesive force ranging from 100 to 1,500 gf / 25 mm on one side of a base film having a thickness ranging from 10 to 100 And a silicone adhesive layer having a thickness in the range of 5 to 70 and an adhesive strength of 1 to 100 gf / 25 mm on the opposite surface.

According to another aspect of the present invention, the adhesive layer may have a structure in which a protective sheet is further attached.

Meanwhile, in the method of manufacturing a screen protective film for a curved display panel of a mobile device according to the present invention, in the molding step, a stepped portion machined on a molding surface of a mold facing the film fabric facing the film fabric is provided, It is preferable that the air is blown out through the void space formed between the film raw material and the molding surface of the mold so that the film is guided to increase the degree of adsorption of the film to the molding surface of the mold. According to this configuration, when the film is brought into contact with the molding surface of the mold during the vacuum molding, a micro air layer is formed and the fabric can be effectively prevented from bulging upward. Therefore, It is easy to secure.

In the hard coating step, the resin film molded body is immersed in a coating solution to dip-coat the resin film, then hot-air dried, and the resin film molded body is reversed to be immersed in the coating solution to form a secondary It is preferable to include a step of dip coating, followed by hot air drying, followed by ultraviolet (UV) curing. According to this configuration, it is possible to minimize the variation in coating thickness over the entire surface of the resin film molded article.

According to the curved display panel screen protective film and the manufacturing method thereof of the mobile device according to the present invention, the following effects can be obtained.

First, transparency of the single-layer structure of the substrate layer is preferentially heated and softened by vacuum-forming the fabric, thereby effectively suppressing and minimizing the springback phenomenon occurring in the conventional press thermal compression molding method. Accordingly, the molding dimensional accuracy and the curvature of the curved protective film can be effectively improved.

Secondly, it is possible to provide a protective film that can be stably and firmly adhered to the display panel by increasing the conformity corresponding to the surface of the curved display panel by improving the dimensional accuracy of the molding and the curvature.

Thirdly, since the hard coating layer is formed through a separate process after the process of forming the material layer of the substrate layer, cracks in the hard coating layer occurring in the conventional press thermal compression molding method can be effectively prevented. As a result, the quality and productivity of the curved protective film can be greatly improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating a curved display panel screen protective film of a mobile device according to the present invention. FIG.
2 is a schematic cross-sectional view cut along the line II-II in Fig.
FIG. 3 is a schematic cross-sectional view of an enlarged view of the laminating structure by extracting the circular A portion of FIGS. 1 and 2. FIG.
4 is a schematic view illustrating a manufacturing process of a curved display panel screen protective film of a mobile device according to the present invention.
5 is a schematic view showing a main process of a screen protective film manufacturing method of a curved display panel of a mobile device according to the present invention.
FIG. 6 is a schematic cross-sectional view illustrating a mold used in a method of manufacturing a screen protective film of a curved display panel of a mobile device according to the present invention and a curved display panel screen protective film using the mold. FIG.
7 is a schematic view illustrating a hard coating process of a screen protective film manufacturing method for a curved display panel of a mobile device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a curved display panel screen protective film and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

The following description and the accompanying drawings are merely exemplary embodiments of the present invention and are not to be construed as limiting the screen protective film of the curved display panel of the mobile device according to the present invention and the manufacturing method thereof.

The mobile device of the present invention is not limited to a specific portable electronic device such as a smart phone or a tablet PC. For example, the mobile device may be a personal digital assistant (PDA), a mobile communication terminal, an MP3 player, a game machine, Can be defined as meaning a general portable electronic device provided with a multimedia display panel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating a curved display panel screen protective film of a mobile device according to the present invention; FIG. FIG. 2 is a schematic cross-sectional view cut along the line II-II of FIG. 1, and FIG. 3 is a schematic cross-sectional view showing an enlarged view of the laminating structure by extracting the circular portion A of FIGS.

1 to 3, a curved display panel screen protective film 100 of a mobile device according to the present invention is for protecting a screen by attaching to a curved display panel (not shown) of a mobile device, Transparency of Structure The hard coating layers 111 and 112 are laminated on both sides of the synthetic resin film 110 and adhered to the hard coating layer 111 provided on one surface of the curved display panel of the mobile device, Layer 120 is formed.

In the curved display panel screen protective film 100 of the mobile device according to the present invention having the above-described structure, the synthetic resin film 110, the hard coating layers 111 and 112, The manufacturing process is characterized in that it is formed as a laminated structure through separate processes which are separate steps.

According to the present invention, the synthetic resin film 110 is heated and softened through a preheating process, and at least one pair of opposing rim sides are bent downward to one side by vacuum molding to form a rounded curvature portion 101 . Accordingly, the synthetic resin film 110 forms a three-dimensional molded article having a concave surface and a convex surface corresponding to a curved display panel (not shown).

That is, the concave surface of the molded body forms an attachment surface facing the curved display panel, and the convex surface forms a contact surface of the user's finger or the touch pen when the touch screen is operated.

According to one aspect of the present invention, the synthetic resin film 110 is formed of a polymer compound such as polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), polyurethane (PU) and polycarbonate As the transparent resin film body, it is preferable to have a thickness in the range of 10 to 200. [

The hard coating layers 111 and 112 serve to prevent surface damage due to scratches by forming a hard coating on the surface of the synthetic resin film 110. For example, An organic coating agent of urethane acrylate system and an organic or inorganic hybrid coating agent containing nano silica may be effectively employed.

According to one aspect of the present invention, the hard coat layer 111 and 112 are formed by reacting an organosilane coupling agent with a nanosilica using a sol-gel method, and then subjecting the resulting coating to an ordinary spray coating, dip coating, It is preferable to have a thickness ranging from 1 to 100 through the application of the process. The thickness range of the hard coating layer 111 (112) is intended to optimize physical properties of abrasion resistance, transparency, flexibility and workability, and to prevent a warping phenomenon occurring in the curing process.

That is, the organic or inorganic hybrid coating agent as described above is formed as a composite having intermediate characteristics between an inorganic material and an organic material by adding an organic material to the inorganic precursor using a sol-gel method and reacting, thereby having advantages of abrasion resistance and transparency While maximizing the flexibility and processability of the organic material.

The adhesive layer 120 is formed by adhering a double-sided adhesive film on a hard coating layer 111 formed on a concave surface of the synthetic resin film 110. The adhesive layer 120 is formed by buffering action of the adhesive layer 120, It is possible to improve the impact resistance.

According to one aspect of the present invention, the adhesive layer 120 is formed on one side of a base film having a thickness ranging from 10 to 100, and has a thickness in the range of 5 to 70 and an adhesive strength of 100 to 1,500 gf / And a silicone adhesive layer having a thickness in the range of 5 to 70 and an adhesive strength of 1 to 100 gf / 25 mm on the opposite surface.

According to another aspect of the present invention, a protective sheet (not shown) may be further attached to the adhesive layer 120.

Hereinafter, a method of manufacturing a screen protective film for a curved display panel of a mobile device according to the present invention will be described in detail.

FIG. 4 is a schematic view illustrating a manufacturing process of a curved display panel protective film of a mobile device according to the present invention. FIG. 5 is a cross- Which is a schematic diagram showing a main process of the method.

4 and 5, in a method of manufacturing a screen protective film for a curved display panel of a mobile device according to the present invention, a film material is prepared (step S-10), the film material is heated to preheat S-20), a curved protective film formed body 110M is formed by vacuum thermal molding (S-30 step), and hard coating layers 111 and 112 are formed on both sides of the protective film formed body 110M (S-50) of forming a pressure-sensitive adhesive layer 120 on the hard coating layer 111 formed on the inner side surface of the curved display panel facing the curved display panel, And a processing step (S-60).

In the process for preparing a screen protective film for a curved display panel of a mobile device according to the present invention having the above-described process steps, in the film fabric preparation step (S-10), for example, polyethylene terephthalate (PET) A resin film 110 in the form of a transparent sheet made of a polymer compound such as polymethylmethacrylate (PMMA), polyurethane (PU), or polycarbonate (PC), and has excellent water permeability, refractive index, It is preferable to have a thickness in the range of 10 to 200 in consideration of the characteristics.

5 (a), the synthetic resin film 110 prepared as a raw material of the film is placed on the table 32 on which the mold 31 of the vacuum thermoforming system is mounted Is set in a stretched state so as to be pulled tightly by using the frame (33) and the clamp (34) provided on the upper part.

Meanwhile, it is necessary that the resin film 110 is cut to a size larger than the outer size of the mold 31 in the fabric preparation step (S-10). The reason for this is to secure a space between the frame 33 and the clamp 31 and the mold 31, which are held in the up and down direction by holding the resin film 110 for vacuum thermal molding.

Subsequently, as shown in Fig. 5 (b), in the temperature range of 100 to 200 forming the softening point of the resin film 110 stretched by the frame 33 and the clamp 34 using the movable heater H, Heat for 1 to 120 seconds.

As shown in Fig. 5 (c), when the resin film 110 softened by the preheating is stretched in the molding step S-30, the frame 33 and the clamp 34 And is set in a state of being in contact with the surface of the mold 31 by descending. The frame 33 and the clamp 34 are fixed and can be set in contact with the surface of the mold 31 by the rise of the mold 31. [ At this time, the air filled between the resin film 110 and the mold 31 is evacuated through the decompression operation in the lower part of the mold 31, The resin film 110 is brought into close contact with the surface of the mold 31 as shown in FIG.

In the molding step S-30 of the present invention, at least one pair of opposing edge portions of the resin film 110 is formed by being bent downward to one surface side so as to have a rounded curvature portion 101. Accordingly, the resin film 110 forms a three-dimensional structure of a film formed body 110M having a concave surface and a convex surface corresponding to a curved display panel (not shown).

According to one aspect of the present invention, the mold 31 has a stepped surface 31a on one side or both sides of the molding surface 31a, which is in contact with the film material 110 facing the film, as illustrated in FIG. 6 (a) It is preferable to have a configuration in which the portion 31b is processed.

The stepped portion 31b functions to form a void space s between the film material 110 and the molding surface 31a of the mold 31 during vacuum forming as illustrated in Figure 6 (b) As the air can be easily taken out through the void space s, the degree of adsorption of the film material 110 on the molding surface 31a of the mold 31 can be effectively increased.

That is, when the film material 110 is brought into contact with the molding surface 31a of the mold 31 during the normal vacuum forming process, a phenomenon occurs in which the film material 110 bulges upward convexly as the micro air layer is formed In the manufacturing method according to the present invention, since the step 31b is provided on the molding surface 31a of the metal mold 31, it is possible to effectively prevent the phenomenon that the film material 110 bulges upward convexly do. As a result, more accurate molding quality can be ensured.

According to the present invention, it is preferable that the stepped portion 31b of the mold 31 is processed to have a dimensional height of 2 to 5 times the thickness of the film material 110 for effective air blowing.

5 (e), the vacuum state is released to cool the mold 31, and then the frame 33 and the clamp 34 (Fig. 5 , The film molded body 110M is unloaded to separate the resin film molded body 110M from the metal mold 31 as shown in Fig. 5 (f).

Meanwhile, in the embodiment of the present invention illustrated in FIG. 5, the drape forming method using the male mold is illustrated as an example of the mold 31. However, as another embodiment of the present invention, A straight forming method of vacuum-adsorbing the preheated resin film may be applied.

In the hard coating layer forming step S-40, a hard coating layer 111 and a hard coating layer 111 are formed on both surfaces of the molded protective film 110M formed in the molding step S-30, that is, .

The hard coating layers 111 and 112 serve to prevent surface damage due to scratches by forming a hard coating on the surface of the synthetic resin film 110. For example, An organic coating agent of urethane acrylate system and an organic or inorganic hybrid coating agent containing nano silica may be effectively employed.

According to one aspect of the present invention, the hard coat layer 111 and 112 are formed by reacting an organosilane coupling agent with a nanosilica using a sol-gel method, and then subjecting the resulting coating to an ordinary spray coating, dip coating, It is preferable to have a thickness ranging from 1 to 100 through the application of the process. The thickness range of the hard coating layer 111 (112) is intended to optimize physical properties of abrasion resistance, transparency, flexibility and workability, and to prevent a warping phenomenon occurring in the curing process.

That is, the organic or inorganic hybrid coating agent as described above is formed as a composite having intermediate characteristics between an inorganic material and an organic material by adding an organic material to the inorganic precursor using a sol-gel method and reacting, thereby having advantages of abrasion resistance and transparency While maximizing the flexibility and processability of the organic material.

FIG. 7 is a schematic view illustrating the hard coating layer forming process. Referring to FIG. 7, in the hard coating layer forming step (S-40), the resin film molded body 110M is first dip- (Step S-41), followed by hot-air drying (S-42 step) for 1 to 2 hours at a temperature range of 100 to 200 for the resin film formed body 110M having the primary hard coating layer formed thereon. (S-43), followed by dip coating (D-Coating), and hot air drying (S-44) ) Curing step (S-45 step).

According to the hard coating layer forming step as described above, it is possible to effectively minimize the coating thickness deviation with respect to the entire surface of the resin film molded article, so that the surface hardness deviation of the coating film can be easily and efficiently solved.

In the adhesive layer forming step (S-50), the adhesive layer 120 is formed by adhering a double-sided adhesive film to the hard coat layer 111 formed on the concave surface of the resin film formed body 110M.

According to one aspect of the present invention, the adhesive layer 120 is formed on one side of a base film having a thickness ranging from 10 to 100, and has a thickness in the range of 5 to 70 and an adhesive strength of 100 to 1,500 gf / And a silicone adhesive layer having a thickness in the range of 5 to 70 and an adhesive strength of 1 to 100 gf / 25 mm on the opposite surface.

In the last step S-60, the protective film 100 formed by stacking the resin film molded product 110M, the hard coat layer 111, and the adhesive film 120, For example, trimming of edges and holes, removal of burrs by laser cutting, CNC machining, or the like. Finally, the curved surface display of the mobile device according to the present invention as described with reference to Figs. 1 to 3 The panel screen protective film 100 is completed.

According to an aspect of the present invention, a protective sheet (not shown) may be further attached to the adhesive layer 120 of the protective film 100 although not illustrated by the drawings.

The present invention is not limited to the above-described specific preferred embodiments, and various changes and modifications may be made to the present invention without departing from the scope of the present invention as defined in the claims. And such changes are within the scope of the claims set forth.

100: protective film
101: Curvature portion
110: synthetic resin film (110)
111, 112: hard coating layer
120: Adhesive layer

Claims (12)

delete delete delete delete delete A protective film for protecting a screen attached to a curved display panel includes a resin sheet constituting a substrate and a hard coating layer formed on the resin sheet,
A preheating step of heating and softening the resin sheet;
Wherein the softened resin sheet is molded by vacuum heat molding to at least one pair of opposing edges of the resin sheet is bent downward to one side to form a concave surface and a convex surface corresponding to the curved display panel by a rounded curvature portion, step; And
Performing a coating step of forming a hard coating layer on the molded resin sheet after molding the resin sheet,
Wherein the coating step of forming the hard coating layer on the molded resin sheet comprises:
The resin sheet thus formed is immersed in a coating liquid to dip-coat the resin sheet first, then hot-air dried, and the resin sheet is subjected to dip coating by immersing it in a coating solution, Followed by hot air drying and ultraviolet (UV) curing to form a hard coat layer on the resin sheet.
The method according to claim 6,
The resin sheet is characterized by being made of at least one of polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyurethane (PU) and polycarbonate (PC) having a thickness in the range of 10 to 200 μm Wherein the surface protective film is formed on the surface of the substrate.
The method according to claim 6,
Wherein the hard coating layer is made of at least one material selected from the group consisting of an organic coating material, an inorganic coating material, and an organic-inorganic hybrid coating material in which an organic material and an inorganic material are uniformly mixed with each other.
The method according to claim 6,
Further comprising an adhesive layer forming step of forming an adhesive layer on the hard coating layer,
The double-sided pressure-sensitive adhesive film has a thickness in the range of 5 to 70 mu m and a thickness in the range of 100 to 1,500 gf / 25 mm on one side of the base film having a thickness in the range of 10 to 100 mu m. And a silicone adhesive layer having a thickness in the range of 5 to 70 mu m and an adhesive strength of 1 to 100 gf / 25 mm on the opposite side.
10. The method of claim 9,
Further comprising a protective sheet adhered to the adhesive layer. ≪ RTI ID = 0.0 > 21. < / RTI >
11. The method according to any one of claims 6 to 10,
In the step of molding the resin sheet, a step portion 31b is provided on the molding surface 31a of the mold 31 in contact with the resin sheet facing the resin sheet, and the step portion 31b of the mold 31 presses the resin (S) formed between the sheet and the molding surface (31a) of the mold (31). delete

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