KR20200119763A - Elongated optical film, light source film including the same and method of manufacturing the same - Google Patents

Abstract

Disclosed is an optical film having an optical material layer and an optical adhesive layer capable of controlling resilience while having high elongation. The optical film includes the optical adhesive layer and the optical material layer formed on the optical adhesive layer. Here, the optical material layer is prepared by using an ultraviolet curable resin containing isoprene acrylate, butadiene acrylate, or urethane acrylate so as to have stretchability. The optical adhesive layer also has stretchability.

Description

A stretchable light guide film, a light source film including the same, and a manufacturing method thereof TECHNICAL FIELD {ELONGATED OPTICAL FILM, LIGHT SOURCE FILM INCLUDING THE SAME AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a stretchable light guide film, a light source film including the same, and a method of manufacturing the same.

With the development of LED light sources, the surface light source lighting market has grown to a level that can be made thinner and larger area, and the luminance has also been improved to a higher level compared to general incandescent and fluorescent lamps.

Initially, the surface light source was manufactured using a PC light guide plate formed by injection, but the light emission level was significantly lowered and the size was very small, so it was used for small LCD panels. However, with the development of optical technology and injection technology, a thin 6.2-inch light guide plate was developed by injection molding, resulting in an average luminance of 8,000 Nits. In addition, in the case of the PMMA light guide plate produced by extrusion, it has developed to the level applicable to the current 100-inch LCD display.

However, in the case of a light guide plate using PMMA produced by extrusion, only a flat surface light source could be produced, and in the case of a PC made by injection, various shapes can be produced according to the design of the injection mold, but the size is very small, so a large area There is a limit to using the design form.

Most of the existing surface light source products have a flat structure.

The surface light source as shown in FIG. 1 is incident on the light guide plate 12 through the light incident part 21 using a side light source 20 using an LED. The incident light source is emitted to the outside by the reflection pattern 30 to serve as a surface light source. (Refer to Korean Patent Registration No. 1007756330000 (2007.11.05))

In this case, since the light guide plate uses PC and PMMA, it exists in the form of a plane, and it is difficult to make a surface light source having a curved surface.

In order to solve this problem, a flexible light guide film that can be bent in one axis with respect to the X and Y planes using a PC film or the like as shown in Fig. 2 has been proposed. (Korean Patent Registration No. 1008110620000 (2008.02.29)) Reference)

That is, the light rays emitted from the LED light source unit 20 are emitted to the outside by the light guide film 30, and at this time, the light guide film may be bent in one axis.

However, as described above, since the light guide film is also curved only in one axis, it can be applied to a curved surface of one axis, but it is difficult to apply it to a curvature such as a hemi-spheric shape. This is because the light guide film can be bent only to one side because it has no stretchability while using a PC film or the like.

KR 10-1026957 B

The present invention is to provide a stretchable light guide film capable of bending in both the X-axis and the Y-axis, a light source film including the same, and a method of manufacturing the same.

In addition, the present invention is to provide a stretchable light guide film, a light source film including the same, and a method of manufacturing the same so that uniform light rays are emitted to the outside even in a portion where a curved surface exists.

In order to achieve the object as described above, the light guide film according to an embodiment of the present invention includes a resin layer; And patterns formed on the resin layer and preventing total reflection of light traveling into the resin layer so that the light is output to the outside. Here, the resin layer and the patterns are a single layer made of the same optical resin, and the light guide film is transparent and can be bent in both the X axis and the Y axis.

A light source film according to an embodiment of the present invention includes a light source unit; And a light guide film that outputs light emitted from the light source unit. The light guide film includes a resin layer; And patterns formed on the resin layer and outputting light incident from the light source to the outside. Here, the resin layer and the patterns are a single layer made of the same optical resin, and the optical resin is an ultraviolet curable resin containing isoprene acrylate, butadiene acrylate or urethane acrylate to have stretchability.

A method of manufacturing a light guide film according to an embodiment of the present invention includes the steps of applying a transparent optical resin on a carrier film; Passing the carrier film coated with the optical resin through a roller on which a pattern is formed and then curing to form a light guide film on the carrier film in which the resin layer and the patterns form a single layer; And separating the carrier film. Here, the light guide film is transparent and can be bent in both the X-axis and the Y-axis, and the resin layer and the patterns are made of the optical resin.

Since the light guide film and the light source film including the same according to the present invention can be bent in both the X-axis and the Y-axis, the design freedom is high, the manufacturing cost can be reduced, and can be used for various types of light sources.

1 and 2 are views showing a conventional light source film.
3 is a view showing a light guide film according to an embodiment of the present invention.
4 is a view showing a light source film according to an embodiment of the present invention.
5 is a view showing the stretchability of a light guide film according to an embodiment of the present invention.
6 is a diagram illustrating a process of manufacturing a light guide film according to an embodiment of the present invention.
7 is a diagram illustrating a process of manufacturing a light guide film according to another embodiment of the present invention.
8 is a diagram illustrating a process of manufacturing a light source film according to an embodiment of the present invention.
9 to 11 are views showing the manufactured light source film.

Singular expressions used in the present specification include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various elements or various steps described in the specification, and some of the elements or some steps It may not be included, or it should be interpreted that it may further include additional elements or steps. In addition, terms such as "... unit" and "module" described in the specification mean units that process at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software. .

The present invention relates to a transparent light guide film having stretchability and a light source film including the same, wherein the light guide film can be bent with stretchability in all directions of the X-axis and the Y-axis, and has its own pattern. Of course, bending in the Z-axis direction may be possible.

Such a light source film may be used as a light source having high design freedom in a curved LCD and a backlight unit for general lighting.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a view showing a light guide film according to an embodiment of the present invention, Figure 4 is a view showing a light source film according to an embodiment of the present invention, Figure 5 is a light guide according to an embodiment of the present invention It is a diagram showing the stretchability of the film.

3 and 4, the light source film according to the present embodiment may include a light guide film and a light source unit 122.

The light guide film is composed of a single layer made of an optical resin having UV-curing properties, and may include a light-incident portion 120 to which light is incident from the light source portion 122 and a self-formed pattern 112.

Such a light source film is a surface lighting, and can be variously used as a light source for display devices, automobiles, clothing, and the like. For example, when the light source film is installed in a vehicle, when a sensor detects that another vehicle passes by, the light source film may output a preset light.

According to an embodiment, the patterns 112 may be regularly formed on one surface, for example, a lower surface of the light guide film, and uniformly transmit light that has progressed to the outside by interfering with the total internal reflection of the resin layer 110 Can be printed. For example, when light output from the light source unit 122 is incident on the side surface of the light guide film, that is, the light incident unit 120, the incident light is transmitted to the inside of the light guide film and is uniform to the outside by the patterns 112. Can be printed. Of course, depending on the design, the patterns 112 may be irregularly formed to output light unevenly.

In addition, the pattern 112 may have various shapes such as a micro lens, a prism shape, a pyramid shape, a wave shape, or a square pyramid shape.

According to an embodiment, the resin layer 110 and the patterns 112 formed on the resin layer 110 may be formed of the same optical resin through a single process. As a result, the resin layer 110 and the patterns 112 have the same refractive index, and thus the efficiency of the patterns 112 may be improved.

According to an embodiment, the light guide film including the resin layer 110 and the patterns 112 is a UV-curable resin containing one of isoprene acrylate, butadiene acrylate and urethane acrylate containing an acrylate group as a main component. It can be manufactured using. That is, the light guide film may be made of an isoprene acrylate compound, a butadiene acrylate compound, or a urethane acrylate compound, as shown in the structures below.

The light guide film forms an amorphous linear film using one of isoprene acrylate, butadiene acrylate, and urethane acrylate as a main chain. At this time, the appropriate elongation is at the level of 100% to 500%, preferably at the level of 200% to 400%, and more preferably at the level of 250% to 350%.

If the elongation is 400% or more, the elongation is excellent, but the restoring force to be restored to the original shape is strong, making it difficult to use in a section with severe curvature, and if it is less than 200%, it is difficult to maintain thickness stability.

Structure 1. Isoprene acrylate compound

Structure 2. Butadiene acrylate compound

Structure 3. Urethane acrylate compound

Of course, as long as the light guide film has stretchability, the optical resin forming the resin layer 110 and the patterns 112 is not limited to the above optical resin, and various optical resins may be used.

According to an embodiment, the light guide film may have a refractive index of 1.45 to 1.65.

According to an embodiment, the light guide film may have a thickness in the range of 100 μm to 500 μm.

1. Examples of stretchable light guide film

Example 1

Isoprene-based acrylate 40%, nonyl acrylate 25%, 2-hydroxyl ethyl acrylate 15%, isobornyl acrylate 10%, hexanediol diacrylate 10% and photoinitiator 2% (1-hydroxycyclohexylphenyl Ketone 1% and 2,4,6-trimethylbenzoyl-diphenyl-diphenyl phosphine 1%) were added and stirred at 25°C for 1 hour. Subsequently, the substances were filtered using a filter to obtain an ultraviolet curable resin composition.

Example 2

It was carried out in the same manner as in Example 1 except for isoprene-based acrylate 30% and 2-hydroxyl ethyl acrylate 25%.

Example 3

It was carried out in the same manner as in Example 1 except for isoprene-based acrylate 20%, nonyl acrylate 30%, and 2-hydroxyl ethyl acrylate 30%.

Example 4

It was carried out in the same manner as in Example 1 except for 10% isoprene-based acrylate, 35% nonyl acrylate, and 35% 2-hydroxyl ethyl acrylate.

Example 5

Butadiene acrylate 40% and nonyl acrylate 25%, 2-hydroxyl ethyl acrylate 15%, isobornyl acrylate 10%, hexanediol diacrylate 10% and photoinitiator 2% (1-hydroxycyclohexylphenyl Ketone 1% and 2,4,6-trimethylbenzoyl-diphenyl-diphenyl phosphine 1%) were added and stirred at 25°C for 1 hour. Thereafter, the substances were filtered using a filter to obtain an ultraviolet curable resin composition.

Example 6

It was carried out in the same manner as in Example 5 except for 30% of butadiene-based acrylate and 25% of 2-hydroxyl ethyl acrylate.

Example 7

Except for butadiene-based acrylate 20%, nonyl acrylate 30%, and 2-hydroxyl ethyl acrylate 30% were carried out in the same manner as in Example 5.

Example 8

Except for butadiene-based acrylate 10%, nonyl acrylate 35%, and 2-hydroxyl ethyl acrylate 35% were carried out in the same manner as in Example 5.

Example 9

Urethane acrylate 40%, nonyl acrylate 25%, 2-hydroxyl ethyl acrylate 15%, isobornyl acrylate 10%, hexanediol diacrylate 10% and photoinitiator 2% (1-hydroxycyclohexylphenyl ketone 1% and 2,4,6-trimethylbenzoyl-diphenyl-diphenyl phosphine 1%) were added and stirred at 25°C for 1 hour. Thereafter, the substances were filtered using a filter to obtain an ultraviolet curable resin composition.

Example 10

It was carried out in the same manner as in Example 9 except for 30% of butadiene-based acrylate and 25% of 2-hydroxyl ethyl acrylate.

Example 11

* Except for butadiene-based acrylate 20%, nonyl acrylate 30%, and 2-hydroxyl ethyl acrylate 30% were carried out in the same manner as in Example 9.

Example 12

Except for butadiene-based acrylate 10%, nonyl acrylate 35%, and 2-hydroxyl ethyl acrylate 35% were carried out in the same manner as in Example 9.

Table 1 shows the results evaluated by the above evaluation method for the transparent stretched layer material layer prepared in the Example or Comparative Example.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Isoprene system 40 30 20 10 Butadiene 40 30 20 10 Urethane 40 30 20 10 Nonyl acrylate 25 25 30 35 25 25 30 35 25 25 30 35 HEA 15 25 30 35 15 25 30 35 15 25 30 35 IBOA 10 10 10 10 10 10 10 10 10 10 10 10 HDDA 10 10 10 10 10 10 10 10 10 10 10 10 Initiator 1 One One One One One One One One One One Initiator 2 One One One One One One One One One One Refractive index 1.495 1.49 1.48 1.47 1.495 1.48 1.47 1.46 1.51 1.5 1.49 1.48 Elongation (%) 250 190 140 80 300 210 160 70 500 380 250 90 Transmittance (%) 90 91 92 93 88 89 91 91 89 91 92 93 Property result OK OK X X OK OK X X Increased resilience OK OK X

Assessment Methods

1. Measurement of elongation

The stretching properties of Examples and Comparative Examples were evaluated in the following manner. The specimen was prepared by cutting a film prepared according to Examples or Comparative Examples so that the horizontal length was 15 mm and the vertical length was 90 mm. Subsequently, the tapered portion was fixed to a measuring device (XP plus, TA (manufactured)) after taping and wrapping the top and bottom 10 mm each in the vertical direction. Subsequently, while the specimen was stretched in the longitudinal direction at a tensile speed of 300 mm/min at room temperature, the stretching properties were evaluated according to the distance until the specimen was cut.

* 2. Thermal shock test

The thermal shock properties of Examples and Comparative Examples were evaluated in the following manner. The specimen is attached to a glass substrate having a four-sided curved shape, and then left for 30 cycles (times) at -40°C to 85°C for 1 cycle for evaluation.

As for the evaluation method, there should be no changes in appearance such as discoloration, discoloration, cracking, or warping before/after the test, and there should be no peeling from the glass substrate.

3. Hot water test

The thermal shock properties of Examples and Comparative Examples were evaluated in the following manner. The specimen is attached to a glass substrate having a four-sided curved shape, left for 100°C for minutes, and then left at room temperature for 4 hours for evaluation.

As for the evaluation method, there should be no changes in appearance such as discoloration, discoloration, cracking, or warping before/after the test, and there should be no peeling from the glass substrate.

4. High temperature, high humidity test

The thermal shock properties of Examples and Comparative Examples were evaluated in the following manner. After attaching the specimen to a glass substrate having a four-sided curved shape, it is evaluated after leaving it for 72 hours at 50℃ and humidity in a thermo-hygrostat.

As for the evaluation method, there should be no changes in appearance such as discoloration, discoloration, cracking, or warping before/after the test, and there should be no peeling from the glass substrate.

5. Severe high temperature, high humidity test

The thermal shock properties of Examples and Comparative Examples were evaluated in the following manner. After attaching the specimen to a glass substrate having a four-sided curved shape, it is evaluated after leaving it for 72 hours at 85° C. humidity in a thermo-hygrostat.

As for the evaluation method, there should be no changes in appearance such as discoloration, discoloration, cracking, or warping before/after the test, and there should be no peeling from the glass substrate.

6. Chemical resistance test

The thermal shock properties of Examples and Comparative Examples were evaluated in the following manner. The specimen is attached to a glass substrate having a four-sided curved shape, left to stand for 4 hours, and then left in a beaker containing alcohol for 1 hour for evaluation.

As for the evaluation method, there should be no changes in appearance such as discoloration, discoloration, cracking, or warping before/after the test, and there should be no peeling from the glass substrate.

Table 2 shows the results evaluated by the above evaluation method for the transparent stretched layer material layer prepared in the Example or Comparative Example.

division Elongation
(%) Thermal shock Heat-resistant bath High temperature and high humidity
(One) High temperature and high humidity
(2) Chemical resistance Example 1 250 OK △ ◎ ◎ NG Example 2 190 △ X △ △ NG Example 3 140 △ △ △ △ NG Example 4 80 X X X X NG Example 5 300 OK ◎ ◎ ◎ ◎ Example 6 210 OK ◎ ◎ ◎ ◎ Example 7 160 △ X △ △ X Example 8 70 X X X X X Example 9 500 OK ◎ ◎ ◎ ◎ Example 10 380 OK ◎ ◎ ◎ ◎ Example 11 250 OK ◎ ◎ ◎ ◎ Example 12 90 X X X X X

Hereinafter, a process of manufacturing the light guide film of the present invention will be described.

6 is a view showing a process of manufacturing a light guide film according to an embodiment of the present invention, FIG. 7 is a view showing a process of manufacturing a light guide film according to another embodiment of the present invention, and FIG. A diagram showing a process of manufacturing a light source film according to an embodiment of the present invention. 9 to 11 are views showing the manufactured light source film.

The light guide film of the present invention may be manufactured using a flat pattern mold as shown in FIG. 6 or may be manufactured using a pattern roller as shown in FIG. 7.

Referring to FIG. 7, first, the carrier film 100 is put in, and the carrier film 100 is transferred to the pattern roller 330 using a tension adjusting roller 210 so that wrinkles do not occur, and the carrier film 100 is transferred to the pattern roller 330. By this, the pattern 112 is formed.

At this time, in order to adjust the thickness of the desired stretchable light guide film, the optical resin released through the stretchable optical resin coating unit 310 is primarily maintained in a desired thickness using a scriber 320.

Then, the final thickness is adjusted using a press roller 220.

Subsequently, it is cured using an ultraviolet curing device 340 and then released from a roller to manufacture a product.

Subsequently, the stretchable light guide film manufactured by the above method is punched into a desired size and connected to the LED array to manufacture the stretchable light source film as shown in FIG. 8.

In summary, a light guide film including the resin layer 110 and patterns 112 made of the same optical resin is formed in a single process, and a light guide film may be manufactured by connecting the light guide film to the LED array unit.

Such a light source film may be mounted to fit the curvature of a dashboard of a vehicle as illustrated in FIGS. 9 to 10, and may have a free curvature as illustrated in FIG. 11.

Meanwhile, the constituent elements of the above-described embodiment can be easily grasped from a process point of view. That is, each component can be identified as a respective process. In addition, the process of the above-described embodiment can be easily grasped from the viewpoint of the components of the device.

In addition, the above-described technical contents may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiments, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of the program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

The above-described embodiments of the present invention have been disclosed for the purpose of illustration, and those skilled in the art who have ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes and additions It should be seen as belonging to the following claims.

100: light guide film 110: resin layer
112: pattern

Claims (5)

In the light guide film,
Resin layer; And
Patterns formed on the resin layer and interfering with total reflection of light traveling into the resin layer so that the light is output to the outside,
The resin layer and the patterns are a single layer made of the same optical resin, and the light guide film is transparent and can be bent in both the X-axis and the Y-axis. The light guide film of claim 1, wherein the optical resin has a refractive index of 1.45 to 1.65, and the light guide film has a thickness in the range of 100 μm to 500 μm. The light guide film of claim 1, wherein the resin layer and the patterns are formed through a single process, and the pattern has a microlens, a prism shape, a pyramid shape, a wave shape, or a square pyramid shape. Light source unit; And
It includes a light guide film for outputting the light emitted from the light source,
The light guide film,
Resin layer; And
Includes patterns formed on the resin layer and outputting light incident from the light source to the outside,
The resin layer and the patterns are a single layer made of the same optical resin, and the optical resin is a UV-curable resin containing isoprene acrylate, butadiene acrylate or urethane acrylate so as to have stretchability. Applying a transparent optical resin on the carrier film;
Passing the carrier film coated with the optical resin through a roller on which a pattern is formed and then curing to form a light guide film on the carrier film in which the resin layer and the patterns form a single layer; And
Including the step of separating the carrier film,
The light guide film is transparent and can be bent in both the X-axis and the Y-axis, and the resin layer and the patterns are made of the optical resin.

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