KR102085243B1 - Lightshielding film with excellent shading properties and method of manufacturing the same - Google Patents

Abstract

Disclosed are a light-shielding film having excellent light-shielding properties, which is designed to secure high-quality light-shielding properties by supplementing unstable light-shielding properties of a single coating layer by applying a double coating method, and a manufacturing method of the same. According to the present invention, the light-shielding film having excellent light-shielding properties comprises: a black film layer; a first light-shielding layer laminated on both sides of the black film layer; and a second light-shielding layer laminated on both sides of the first light-shielding layer.

Description

LIGHTSHIELDING FILM WITH EXCELLENT SHADING PROPERTIES AND METHOD OF MANUFACTURING THE SAME

The present invention relates to a light-shielding film having excellent light-shielding properties and a method of manufacturing the same, and more particularly, excellent light-shielding designed to secure high-quality light-shielding properties by supplementing the unstable light-shielding properties of a single coating layer by applying a double coating method. It relates to a light shielding film having characteristics and a method of manufacturing the same.

Recently, the growth of the camera module has grown along with various fields such as automobiles, smartphones, virtual reality (VR), and drones, and products with high level of technology are being produced. In particular, the need for camera modules in new fields, such as autonomous vehicles and the Internet of Things (IoT), is becoming more important and the size of the market is increasing significantly every year.

In one camera module, a plurality of lenses are used for high magnification and high pixel resolution, and spacers are positioned between the plurality of lenses to maintain the distance between the lenses and to fix the position of the lenses. The number of lenses and spacers of the camera module differs from pixel to pixel, but in general, the module consists of 5MP 4, 13MP 5, 16MP 6 lenses and spacers, and as the number of pixels and magnification increases, the number of lenses is increased. Imaging data can be obtained.

In the smartphone industry's design competition in the global camera module market, the thickness and weight of the camera module are important considerations. In particular, in order to express a high level of camera performance, a technology for mounting a plurality of camera modules such as a dual camera and a quad camera is applied to a smartphone. Camera modules become thicker as they evolve to higher pixels and higher functionality, but there are technical limitations to lightening the lens. Therefore, there is a need for the development of light and thin spacers that are inserted between the lenses to block unnecessary light while maintaining a gap between the lenses.

However, existing camera spacers produced in Korea are mainly at the surface treatment level through the black oxide process after the punching process of the phosphor bronze plate, and thus cannot meet the market demand. In addition, after simply punching the phosphor bronze plate by thickness, there is a problem in that it is difficult to enter a new technology for expressing various characteristics because the drug treatment only stops.

In addition, there is a limit due to the camera spacer using a conventional phosphor bronze according to the trend of miniaturization and light weight of the camera module.

In order to solve the problems caused by the limitation of the phosphor bronze camera spacer, there is an increasing demand to replace the film spacer for the camera. Most film spacers for cameras are produced through the punching process after giving a light shielding effect to the surface of the film through a black coating treatment method.

It is easy to express the characteristics of the desired camera spacer by controlling the black coating liquid coated on the film compared to the camera spacer made from phosphor bronze. For this reason, spacers for film cameras have the advantage of imparting physical and chemical properties required from the market.

However, a film-type camera spacer has a problem in that a burr is generated during the punching process, and thus a defective rate is high. When the burr is punched, the burr is generated while the coating layer adhered to the substrate is peeled off. Dropping of the coating layer reduces the light shielding power of the spacer for the camera has caused a quality degradation problem such as flare phenomenon.

Related prior art documents are Korean Patent Publication No. 10-1806355 (August 12, 2017.), which discloses a tape for waterproofing, impact resistance and shading.

It is an object of the present invention to provide a light shielding film having excellent light shielding properties and a method of manufacturing the same, which are designed to compensate for unstable light shielding characteristics of a single coating layer by applying a double coating method, thereby ensuring high quality light shielding characteristics.

In order to achieve the above object, a light blocking film having excellent light blocking properties according to an embodiment of the present invention includes a black film layer; A first light blocking layer laminated on both surfaces of the black film layer; And a second light blocking layer laminated on both surfaces of the first light blocking layer.

According to an embodiment of the present invention for achieving the above object, a light shielding film manufacturing method having excellent light shielding characteristics may include preparing a black film layer; Coating a first coating dispersion on both sides of the black film layer and drying the first light shielding layer; And coating a second coating dispersion on both surfaces of the first light blocking layer, and drying the second coating layer to form a second light blocking layer laminated on both surfaces of the first light blocking layer.

The light shielding film having excellent light shielding properties according to the present invention and a method of manufacturing the same by forming a first light shielding layer using a high content binder on both sides of the black film layer, while preventing burr phenomenon that may occur during the punching process, Both surfaces of the first light shielding layer may be formed of a second light shielding layer having a high black particle filling rate by using various carbon composite materials for each particle size to improve light shielding characteristics.

As a result, the light-shielding film and the manufacturing method thereof having excellent light-shielding properties according to the present invention have an adhesive force (peel strength) of 25 to 60 gf / mm, an optical density (D) of 4.0 to 7.0 and glossiness of 3GU or less, more preferably May represent a glossiness of 1 GU or less.

In addition, the light-shielding film having excellent light-shielding characteristics and the manufacturing method thereof according to the present invention can further prevent the diffuse reflection of light due to gloss by further adding an anti-reflective agent in the second light-shielding layer.

Such an antireflection agent preferably uses at least one of hollow fine particles and porous fine particles to reduce the difference in refractive index with air, and uses an average particle diameter of 50 nm or less to reduce surface roughness. Silica fine particles can be used as an anti-reflective agent. Such silica fine particles may be dry silica, wet silica, silica fine particles dispersed in a colloidal phase, or the like.

In addition, according to the present invention, a light shielding film having excellent light shielding properties and a method of manufacturing the same are prepared by directly coating and drying the first and second coating dispersions on both sides of the black film layer and the first light shielding layer, respectively, in a comma coated manner. Since the first and second light blocking layers are formed, not only the process is simple but also the initial investment cost is low, thereby reducing the manufacturing cost of the light blocking film.

1 is a perspective view showing a light blocking film having excellent light blocking properties according to an embodiment of the present invention.
2 is a cross-sectional view showing a light blocking film having excellent light blocking properties according to an embodiment of the present invention.
3 is a process flowchart showing a method for manufacturing a light shielding film having excellent light shielding properties according to an embodiment of the present invention.
Figure 4 is a photograph showing the state after the punching for the light-shielding film prepared according to Comparative Example 1.
Figure 5 is a photograph showing the state after the punching for the light-shielding film prepared according to Example 3.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, a light blocking film having excellent light blocking properties and a method of manufacturing the same according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a light blocking film having excellent light blocking properties according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing a light blocking film having excellent light blocking properties according to an embodiment of the present invention.

1 and 2, the light blocking film 100 having excellent light shielding characteristics according to an embodiment of the present invention may include a black film layer 120, a first light blocking layer 140, and a second light blocking layer 160. Include.

The black film layer 120 may have a plate shape having one surface and the other surface opposite to one surface. The black film layer 120 includes a black PET (polyethylene terephthalate) film, a black PC (polycarbonate) film, a black PEN (polyethylenenaphthalate) film, a black PSS (polyphenylene sulfide) film, and a black PES (polyether sulfone) ) Film, black PI (polyimide) film and the like can be used.

As for the thickness of the black film layer 120, 10-50 micrometers is preferable, As a more preferable range, 15-35 micrometers can be presented. When the thickness of the black film layer 120 is less than 10 μm, it is not easy to handle because of poor handling properties during comma coating, and there is a possibility that surface defects such as scratches may occur in the black film layer 120, which is not preferable. On the contrary, when the thickness of the black film layer 120 exceeds 50 μm, it is difficult to reduce the size and weight, and due to the excessive thickness design, stray light is generated due to light reflection when applied as a spacer for a phosphor bronze camera, so that a clear image is taken. Can act as a factor in

The first light blocking layer 140 may be formed by coating and drying the first coating dispersion with a uniform thickness on both surfaces of the black film layer 120 by a comma coating method. Such a comma coating method has an advantage of not only a simple process but also a low initial investment cost, thereby reducing the manufacturing cost of the light shielding film 100.

 Here, it is preferable to use the first light shielding layer 140 in which a large amount of binder is added. As such, when a binder having a high content is added to the first light blocking layer 140, the black film layer 120 may be used during the punching process of the light blocking film 100 by improving adhesion to the black film layer 120. The occurrence of burrs of the first light blocking layer 140 in contact with each other may be prevented in advance, thereby preventing unnecessary light from being incident.

To this end, the first light shielding layer 140 has a higher amount of binder and a lower amount of black fine particles than the second light shielding layer 160 described later.

More specifically, the first light shielding layer 140 is coated and thermally cured the first coating dispersion comprising 45 to 85% by weight of the binder resin, 5 to 30% by weight of the black fine particles, 5 to 10% by weight of the dispersant and the remaining solvent It is preferable to use what was formed.

As the binder resin of the first light blocking layer 140, at least one selected from a silicone resin, an epoxy resin, a polyvinyl resin, an acrylic resin, a polyester resin, a polyurethane resin, and a phenol resin may be used. When the binder resin of the first light shielding layer 140 is less than 45% by weight, adhesiveness with the black film layer 120 is not good, and optical characteristics are deteriorated due to the generation of burrs during the punching process of the light shielding film 100. Can cause problems. On the contrary, when the binder resin of the 1st light shielding layer 140 exceeds 85 weight%, the amount of black fine particles added may decrease and light-shielding property may fall.

Black fine particles of the first light shielding layer 140 are added to improve light shielding properties. When the amount of the black fine particles added to the first light shielding layer 140 is less than 5% by weight, the amount of the black fine particles is insignificant and it is difficult to properly exhibit the light-blocking effect. On the contrary, when the amount of the black fine particles added in the first light shielding layer 140 exceeds 30% by weight, the binder resin content of the first light shielding layer 140 may be reduced to decrease the adhesion to the black film layer 120. have.

In this case, the black fine particles of the first light blocking layer 140 may include two or more kinds of powders of carbon powder, carbon nanotubes, graphite, graphene, and expanded graphite. Here, as the carbon powder, Ketjen black EC-300JD, Ketjen black EC-600JD, etc. may be mentioned, and various carbon powders such as acetylene black may be used.

The dispersant of the first light shielding layer 140 is added to ensure dispersibility of the black fine particles. In this case, the dispersant of the first light blocking layer 140 may be used without limitation as long as the dispersibility of the black fine particles is good and there is no big problem in compatibility with the binder resin. For example, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), or the like may be used as the dispersant of the first light blocking layer 140.

When the dispersant of the first light blocking layer 140 is added in less than 5% by weight, it is difficult to properly exhibit the dispersibility improvement effect. On the contrary, when the dispersing agent of the first light blocking layer 140 is excessively added in excess of 10% by weight, the content of other components is reduced, thereby lowering the adhesive strength and the light blocking property.

The solvent of the first light blocking layer 140 is water, ethanol, isopropanol, acetone, toluene, xylene, n-butyl acetate, isobutyl acetate, ethyl acetate, isobutyl alcohol, cellosolve acetate, ethyl cellosolve, butyl cell One or more selected from Rosolve, etc. may be used.

The first light blocking layer 140 preferably has a thickness of 10 to 40 μm, and more preferably 15 to 30 μm. When the thickness of the first light shielding layer 140 is less than 10 μm, the thickness thereof is insignificant and it is difficult to properly exhibit the adhesive force improving effect. On the contrary, when the thickness of the first light shielding layer 140 exceeds 40 μm, the thickness of the first light blocking layer 140 may be increased without any further effect. Thus, the flexible characteristic disappears and the adhesive force decreases due to the crack on the surface.

The second light blocking layer 160 is stacked on both surfaces of the first light blocking layer 140. The second light blocking layer 160 is disposed on both surfaces of the first light blocking layer 140 to compensate for the light blocking characteristics. Here, it is preferable that the second light shielding layer 160 has a lower amount of binder and a higher amount of black fine particles than the first light shielding layer 140.

As described above, in the present invention, a double coating method in which the second light blocking layer 160 is sequentially stacked on both surfaces of the first light blocking layer 140 is applied to compensate for the unstable light blocking property of the single coating layer, thereby providing a high quality light blocking film. (100) can be manufactured.

To this end, the second light shielding layer 160 is formed by coating and curing a second coating dispersion including 10 to 30% by weight of binder resin, 40 to 70% by weight of black fine particles, 10 to 15% by weight of a dispersant and the remaining solvent. It is preferable to use.

The binder resin of the second light shielding layer 160 is the same as the binder resin of the first light shielding layer 140 among silicone resins, epoxy resins, polyvinyl resins, acrylic resins, polyester resins, polyurethane resins, and phenolic resins. One or more selected may be used. Particularly, the binder resin of the second light blocking layer 160 may be a binder resin of the same series as the binder resin of the first light blocking layer 140, which may be used as the first and second light blocking layers 140 and 160. This is because the adhesive strength of each other may be improved by using the same series of binder resins.

Here, when the binder resin of the second light blocking layer 160 is less than 10% by weight, it is difficult to uniformly disperse the black fine particles added in a high content and the adhesion to the first light blocking layer 140 may be reduced. On the contrary, when the binder resin of the second light blocking layer 160 exceeds 30% by weight, the amount of black fine particles added may decrease, which may cause difficulty in improving light blocking properties.

In this case, the black fine particles of the second light blocking layer 160 may include two or more kinds of powders of carbon powder, carbon nanotubes, graphite, graphene, and expanded graphite. In particular, it is preferable that the black fine particles of the second light shielding layer 160 use particles having different particle sizes from each other. More preferably, the black fine particles of the second light shielding layer 160 may have a particle size of 10 nm to 10 μm, but have a difference in particle size of at least two times or more between the various powders. As described above, in the present invention, the black fine particles of the second light shielding layer 160 are used as the black fine particles, and the particle size between the different powders is different from each other, thereby increasing the filling rate of the black fine particles of the second light blocking layer 160 to increase the light shielding characteristics. It will be possible to improve.

The dispersant and the solvent of the second light blocking layer 160 may be substantially the same as the dispersant and the solvent of the first light blocking layer 140.

In addition, the second coating dispersion may further comprise 1 to 3% by weight of the anti-reflective agent. These anti-reflective agents are added to improve the diffuse reflection of light due to gloss.

It is preferable to use at least one of hollow fine particles and porous fine particles to reduce the difference in refractive index with air, and to use an anti-reflective agent having an average particle diameter of 50 nm or less in order to reduce surface roughness. Silica fine particles can be used as an anti-reflective agent. Such silica fine particles may be dry silica, wet silica, silica fine particles dispersed in a colloidal phase, or the like.

The second light shielding layer 160 preferably has a thickness of 5 to 50 μm, and more preferably 10 to 30 μm. When the thickness of the second light blocking layer 160 is less than 5 μm, the thickness thereof may be too thin, thus making it difficult to properly exhibit the light blocking property. On the contrary, when the thickness of the second light shielding layer 160 exceeds 50 μm, the effect of improving the light shielding characteristics is insignificant, and it is not preferable because it may act as a factor to increase the thickness, resulting in a weight reduction and a thinning. .

Hereinafter, a light shielding film manufacturing method having excellent light shielding characteristics according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a flowchart illustrating a method of manufacturing a light shielding film having excellent light shielding characteristics according to an embodiment of the present invention, which will be described with reference to FIG. 2.

As shown in FIGS. 2 and 3, a method of manufacturing a light shielding film having excellent light shielding characteristics according to an embodiment of the present invention includes preparing a black film layer (S110), forming a first light shielding layer (S120), and a second light shielding. It includes a layer forming step (S130).

Black film layer

In the preparing of the black film layer (S110), the black film layer 120 is prepared.

The black film layer 120 may have a plate shape having one surface and the other surface opposite to one surface. The black film layer 120 includes a black PET (polyethylene terephthalate) film, a black PC (polycarbonate) film, a black PEN (polyethylenenaphthalate) film, a black PSS (polyphenylene sulfide) film, and a black PES (polyether sulfone) ) Film, black PI (polyimide) film and the like can be used.

As for the thickness of the black film layer 120, 10-50 micrometers is preferable, As a more preferable range, 15-35 micrometers can be presented. When the thickness of the black film layer 120 is less than 10 μm, it is not easy to handle because of poor handling properties during comma coating, and there is a possibility that surface defects such as scratches may occur in the black film layer 120, which is not preferable. On the contrary, when the thickness of the black film layer 120 exceeds 50 μm, it is difficult to reduce the size and weight, and due to the excessive thickness design, stray light is generated due to light reflection when applied as a spacer for a phosphor bronze camera, so that a clear image is taken. Can act as a factor in

First Shading Layer Formation

In the first light shielding layer forming step (S120), the first coating dispersion is coated on both surfaces of the black film layer 120 and dried to form the first light shielding layer 140.

This step uses a comma coater to pass through the dryer continuously after the coating process. At this time, the drying is preferably carried out for 10 minutes to 2 hours at 80 ~ 200 ℃ conditions. If the drying temperature is less than 80 ℃ or the drying time is less than 10 minutes may not be sufficient drying can be reduced durability. On the contrary, when the drying temperature exceeds 200 ° C., or when the drying time exceeds 2 hours, it may act as a factor that increases only the manufacturing cost without any further effect increase, and thus is not economical.

In this step, the first light blocking layer 140 may be formed by coating and drying the first coating dispersion with a uniform thickness on both sides of the black film layer 120 by a comma coating method. Such a comma coating method has the advantage of reducing the manufacturing cost of the light-shielding film because the process is simple and the initial investment cost is low.

Here, it is preferable to use the first coating dispersion in which a large amount of binder is added. As such, when the first light shielding layer 140 is formed by using a binder having a high content as the first coating dispersion, the punching process of the light shielding film 100 may be improved by improving adhesion to the black film layer 120. In addition, the occurrence of burrs of the first light blocking layer 140 in contact with the black film layer 120 may be prevented in advance, thereby preventing unnecessary light from being incident.

To this end, the first light shielding layer 140 is formed by coating and curing a first coating dispersion comprising 45 to 85 wt% of binder resin, 5 to 30 wt% of black fine particles, 5 to 10 wt% of a dispersant, and the remaining solvent. It is preferable to use.

As the binder resin of the first coating dispersion, at least one selected from a silicone resin, an epoxy resin, a polyvinyl resin, an acrylic resin, a polyester resin, a polyurethane resin, and a phenolic resin may be used. When the binder resin of the first coating dispersion is less than 45% by weight, the adhesiveness with the black film layer 120 is not good, and thus the optical property is deteriorated due to the generation of burrs during the punching process of the light shielding film 100. May occur. On the contrary, when the binder resin of the 1st coating dispersion exceeds 85 weight%, the addition amount of black microparticles | fine-particles may decrease comparatively and light blocking property may fall.

Black fine particles of the first coating dispersion are added to improve light shielding properties. When the addition amount of the black fine particles of the first coating dispersion is less than 5% by weight, the addition amount is insignificant and it is difficult to properly exhibit the light-shielding effect. On the contrary, when the addition amount of the black fine particles of the first coating dispersion exceeds 30% by weight, the adhesiveness with the black film layer 120 may decrease due to the decrease in the binder resin content of the first coating dispersion.

In this case, the black fine particles of the first coating dispersion may include two or more kinds of powders of carbon powder, carbon nanotubes, graphite, graphene, and expanded graphite. Here, as the carbon powder, Ketjen black EC-300JD, Ketjen black EC-600JD, etc. may be mentioned, and various carbon powders such as acetylene black may be used.

The dispersant of the first light shielding layer 140 is added to ensure dispersibility of the black fine particles. In this case, the dispersant of the first light blocking layer 140 may be used without limitation as long as the dispersibility of the black fine particles is good and there is no big problem in compatibility with the binder resin. For example, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), or the like may be used as the dispersant of the first light blocking layer 140.

When the dispersant of the first light blocking layer 140 is added in less than 5% by weight, it is difficult to properly exhibit the dispersibility improvement effect. On the contrary, when the dispersing agent of the first light blocking layer 140 is excessively added in excess of 10% by weight, the content of other components is reduced, thereby lowering the adhesive strength and the light blocking property.

The solvent of the first light blocking layer 140 is water, ethanol, isopropanol, acetone, xylene, n-butyl acetate, isobutyl acetate, ethyl acetate, isobutyl alcohol, cellosolve acetate, ethyl cellosolve, butyl cellosolve One or more selected from the like can be used.

Second Shading Layer Formation

In the second light shielding layer forming step (S130), the second light shielding layer 160 is coated on both surfaces of the first light shielding layer 140, dried, and the second light shielding layer 160 stacked on both surfaces of the first light shielding layer 140. Form.

This step uses a comma coater to pass through the dryer continuously after the coating process. At this time, the drying is preferably carried out for 10 minutes to 2 hours at 80 ~ 200 ℃ conditions. If the drying temperature is less than 80 ℃ or the drying time is less than 10 minutes may not be sufficient drying can be reduced durability. On the contrary, when the drying temperature exceeds 200 ° C., or when the drying time exceeds 2 hours, it may act as a factor that increases only the manufacturing cost without any further effect increase, and thus is not economical.

In this step, the second light blocking layer 160 may be formed by coating and drying a second coating dispersion on both sides of the first light blocking layer 140 in a uniform thickness by a comma coating method. Such a comma coating method has the advantage of reducing the manufacturing cost of the light-shielding film because the process is simple and the initial investment cost is low.

Here, it is preferable that the second light shielding layer 160 has a lower amount of binder and a higher amount of black fine particles than the first light shielding layer 140.

As described above, in the present invention, a double coating method in which the second light blocking layer 160 is sequentially stacked on both surfaces of the first light blocking layer 140 is applied to compensate for the unstable light blocking property of the single coating layer, thereby providing a high quality light blocking film. It can be prepared.

To this end, the second light shielding layer 160 is formed by coating and curing a second coating dispersion including 10 to 30% by weight of binder resin, 40 to 70% by weight of black fine particles, 10 to 15% by weight of a dispersant and the remaining solvent. It is preferable to use.

As the binder resin of the second coating dispersion, at least one selected from a silicone resin, an epoxy resin, a polyvinyl resin, an acrylic resin, a polyester resin, a polyurethane resin, and a phenolic resin is used, similarly to the binder resin of the first coating dispersion. Can be. In particular, the binder resin of the second coating dispersion is preferably a binder resin of the same series as the binder resin of the first coating dispersion, it is necessary to use the same series of binder resin as the first and second coating dispersions, Because it can be improved.

Here, when the binder resin of the second light shielding layer 160 is less than 10% by weight, it is difficult to uniformly disperse the black fine particles added in a high content and the adhesive strength with the first light shielding layer 140 may be reduced. On the contrary, when the binder resin of the second light blocking layer 160 exceeds 30% by weight, the amount of black fine particles added may decrease, which may cause difficulty in improving light blocking properties.

In this case, the black fine particles of the second light blocking layer 160 may include two or more kinds of powders of carbon powder, carbon nanotubes, graphite, graphene, and expanded graphite. In particular, it is preferable that the black fine particles of the second light shielding layer 160 use particles having different particle sizes from each other. More preferably, the black fine particles of the second light shielding layer 160 may have a particle size of 10 nm to 10 μm, but have a difference in particle size of at least two times or more between the various powders. As described above, in the present invention, the black fine particles of the second light shielding layer 160 are used as the black fine particles, and the particle size between the different powders is different from each other, thereby increasing the filling rate of the black fine particles of the second light blocking layer 160 to increase the light shielding characteristics. It will be possible to improve.

The dispersant and the solvent of the second light blocking layer 160 may be substantially the same as the dispersant and the solvent of the first light blocking layer 140.

As described above, the light blocking film manufacturing method having the excellent light blocking properties according to the embodiment of the present invention may be terminated.

As described above, the light shielding film having excellent light shielding properties and a method of manufacturing the same according to an embodiment of the present invention are formed during punching process by forming a first light shielding layer using a high content of binder on both sides of the black film layer. While preventing burrs from occurring, a second light shielding layer having a high black particle filling rate may be formed on both surfaces of the first light shielding layer by using various carbon composite materials for each particle size, thereby improving light blocking characteristics.

As a result, the light-shielding film having excellent light-shielding properties according to an embodiment of the present invention and a method of manufacturing the same, the adhesive force (peel strength) of 25 ~ 60gf / mm, optical density (D) of 4.0 ~ 7.0 and glossiness of 3GU or less, More preferably, the glossiness of 1GU or less can be shown.

In addition, the light-shielding film having excellent light-shielding properties and the method of manufacturing the same according to an embodiment of the present invention can further prevent the diffuse reflection of light due to gloss by further adding an anti-reflective agent in the second light-shielding layer. .

In addition, according to an embodiment of the present invention, a light shielding film having excellent light shielding characteristics and a method of manufacturing the first and second coating dispersions are coated and dried on the both sides of the black film layer and the first light shielding layer, respectively, by comma coating. Since the first and second light shielding layers are formed, not only the process is simple but also the initial investment cost is low, thereby reducing the manufacturing cost of the light shielding film.

Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, it is presented as a preferred example of the present invention and should not be construed as limiting the present invention by any means.

Details that are not described herein will be omitted because those skilled in the art can sufficiently infer technically.

1. Shading Film Manufacturing

Example 1

A first coating dispersion comprising 50 wt% of polyester resin, 19 wt% of carbon powder having an average diameter of 5 μm, 7 wt% of polyvinylpyrrolidone (PVP), and the remaining water on both sides of a black PET film having a thickness of 25 μm It was coated by a comma coating method and dried at 120 ° C. for 1 hour to prepare a first light shielding layer having a thickness of 15 μm.

Example 2

A first light shielding layer was manufactured in the same manner as in Example 1, except that the polyester resin content was 60 wt% and carbon black 15 wt%.

Example 3

A first light shielding layer was manufactured in the same manner as in Example 1, except that the polyester resin content was 70 wt% and 11 wt% carbon black.

Example 4

A first light shielding layer was manufactured in the same manner as in Example 1, except that the polyester resin content was 80 wt% and carbon black 7 wt%.

Example 5

On both sides of the black PET film having a thickness of 25 μm, a coating dispersion composed of 70 wt% polyester resin, 10 wt% carbon black, 7 wt% polyvinylpyrrolidone (PVP) and the remaining water was coated by a comma coating method, and 120 ° C. It dried for 1 hour at to form a first light blocking layer having a thickness of 15㎛.

Next, 70 wt% of black fine particles in which a polyester resin 10 wt%, carbon powder having an average diameter of 50 nm and graphite powder having an average diameter of 5 μm were mixed at a weight ratio of 1: 1 on both surfaces of the first light shielding layer and polyvinyl. A second coating dispersion composed of 10 wt% of pyrrolidone (PVP) and the remaining water was coated by a comma coating method, and dried at 100 ° C. for 30 minutes to form a second light blocking layer having a thickness of 5 μm. A light shielding film was produced.

Example 6

A 5-layered light-shielding film was manufactured in the same manner as in Example 5 except that the second light-shielding layer was formed at 10 μm.

Example 7

A 5-layered light-shielding film was manufactured in the same manner as in Example 5 except that the second light-shielding layer was formed at 15 μm.

Example 8

A light blocking film having a five-layer structure was manufactured in the same manner as in Example 5, except that the second light blocking layer was formed at 20 μm.

Comparative Example 1

A coating dispersion composed of 40 wt% polyester resin, 30 wt% carbon black, 7 wt% polyvinylpyrrolidone (PVP) and the remaining water was coated by a comma coating method on both sides of a black PET film having a thickness of 25 μm. After drying for 1 hour at to form a light shielding layer having a thickness of 15㎛ to prepare a light-shielding film of a three-layer structure.

Comparative Example 2

On both sides of the black PET film having a thickness of 25 μm, a coating dispersion composed of 70 wt% polyester resin, 10 wt% carbon black, 7 wt% polyvinylpyrrolidone (PVP) and the remaining water was coated by a comma coating method, and 120 ° C. After drying for 1 hour at to form a light shielding layer having a thickness of 15㎛ to prepare a light-shielding film of a three-layer structure.

2. Shading Film Observation

Figure 4 is a photograph showing the state after the punching for the light-shielding film prepared according to Comparative Example 1, Figure 5 is a photograph showing the state after the punching for the light-shielding film prepared according to Example 3.

As shown in Figure 4, the light-shielding film prepared according to Comparative Example 1 can be seen that the burr (Burr) is generated in the edge portion while the black PET film and the light-shielding layer is peeled off during the punching process, which is a black PET film and It is considered that the adhesive force between the light shielding layers is considerably weak at 10 gf / mm.

On the other hand, as shown in Figure 5, the light-shielding film prepared according to Example 3 can be seen that all the surface is smooth without the occurrence of burr, which is 27gf / adhesion between the black PET film and the first light-shielding layer It is judged to be attributable to showing excellent adhesiveness over mm.

3. Property evaluation

Table 1 shows the results of evaluation of the adhesion to the light-shielding film prepared according to Examples 1 to 4 and Comparative Example 1.

1) adhesion

After cutting the light-shielding film prepared according to Examples 1 to 4 and Comparative Example 1 to 10mm in width and 10mm in length, the black film layer and the first light shielding layer at 180 ° angle using a tensile tester (light shielding layer in Comparative Example 1 Peeling was performed to determine the peel strength.

TABLE 1

As shown in Table 1, it was confirmed that the light-shielding film prepared according to Examples 1 to 4 exhibits a tendency to increase the adhesive force as the binder content of the first coating dispersion increases. However, compared to Example 3 in which the binder content of the first coating dispersion was 70 wt%, in Example 4 in which the binder content of the first coating dispersion was 80 wt%, it could be confirmed that the adhesive force slightly decreased.

On the other hand, the light-shielding film prepared according to Comparative Example 1 can be confirmed that due to the binder content of the first coating dispersion is added in a small amount of 40% by weight, the adhesive force is only 10gf / mm below the target value.

Table 2 shows the optical property evaluation results for the light-shielding film prepared according to Examples 5 to 8 and Comparative Example 2.

2) optical density

The optical density of the light shielding ability in the visible light region of 380 ~ 780nm wavelength was measured using an optical density meter. At this time, the optical density as an index of light shielding ability was converted into a transmittance T measured by a spectrophotometer according to the following equation.

Optical Density (D) = Log (1 / T)

3) glossiness

60 ° mirror glossiness (GU) was measured using a gloss meter.

TABLE 2

As shown in Table 2, it can be confirmed that the light-shielding film prepared according to Examples 5 to 8 satisfies both the optical density 4.0 or more and the glossiness 3GU or less corresponding to the target value.

In particular, in Example 7 and Example 8, the optical density was measured as 5.8, respectively, and the glossiness was measured as 0.5GU and 0.4GU, respectively, and it was confirmed that it was the best in terms of shading properties.

On the other hand, the light-shielding film prepared according to Comparative Example 2 was measured to be less than the target value by measuring the optical density of 3.9, it was confirmed that the glossiness was also measured to 4.2GU below the target value.

Although the above has been described with reference to the embodiments of the present invention, various changes and modifications can be made at the level of those skilled in the art. Such changes and modifications can be said to belong to the present invention without departing from the scope of the technical idea provided by the present invention. Therefore, the scope of the present invention will be determined by the claims described below.

100: shading film
120: black film layer
140: first light shielding layer
160: second light shielding layer
S110: black film layer preparation step
S120: forming a first light shielding layer
S130: forming a second light shielding layer

Claims (10)

Black film layer;
A first light blocking layer laminated on both surfaces of the black film layer; And
A light blocking film comprising; a second light blocking layer laminated on both surfaces of the first light blocking layer.
The first light shielding layer has a higher amount of binder resin and a lower amount of black fine particles than a second light shielding layer,
As the black fine particles of the second light shielding layer, two or more kinds of powders of carbon powder, carbon nanotubes, graphite, graphene, and expanded graphite are used, and the black fine particles of the second light blocking layer have a particle size of 10 nm to 10 μm. Using different particle sizes of the various powders,
The light shielding film has excellent light shielding properties, characterized in that it has a peel strength of 25 ~ 60gf / mm, an optical density of 4.0 ~ 7.0 and glossiness of less than 3GU.
The method of claim 1,
The black film layer
A light shielding film having excellent light shielding characteristics, characterized in that the black PET film having a thickness of 10 ~ 50㎛.
delete The method of claim 1,
The first light blocking layer is
A light-shielding film having excellent light-shielding characteristics, characterized in that formed by coating and curing a first coating dispersion comprising 45 to 85% by weight of binder resin, 5 to 30% by weight of black fine particles, 5 to 10% by weight of a dispersant, and the remaining solvent.
The method of claim 1,
The second light blocking layer is
A light-shielding film having excellent light-shielding characteristics, characterized in that formed by coating and curing a second coating dispersion comprising 10 to 30% by weight of binder resin, 40 to 70% by weight of black fine particles, 10 to 15% by weight of a dispersant and the remaining solvent.
delete Preparing a black film layer;
Coating a first coating dispersion on both sides of the black film layer, and drying to form a first light blocking layer; And
And coating a second coating dispersion on both sides of the first light shielding layer, and drying to form a second light shielding layer laminated on both surfaces of the first light shielding layer to manufacture a light shielding film.
The first light shielding layer has a higher amount of binder resin and a lower amount of black fine particles than a second light shielding layer,
As the black fine particles of the second light shielding layer, two or more kinds of powders of carbon powder, carbon nanotubes, graphite, graphene, and expanded graphite are used, and the black fine particles of the second light blocking layer have a particle size of 10 nm to 10 μm. Using different particle sizes of the various powders,
The light shielding film has an excellent light shielding property, characterized in that it has a peel strength of 25 ~ 60gf / mm, an optical density of 4.0 ~ 7.0 and glossiness of less than 3GU.
The method of claim 7, wherein
In the first light shielding layer forming step,
The first light shielding layer is a method of manufacturing a light shielding film having excellent light shielding characteristics, characterized in that the coating by coating a first coating dispersion on both sides of the black film layer by a comma coating method, and dried.
The method of claim 7, wherein
In the forming of the second light blocking layer,
The second light shielding layer is a method of manufacturing a light shielding film having excellent light-shielding characteristics, characterized in that the coating by coating a second coating dispersion on both sides of the first light-shielding layer by a comma coating method, and dried.
The method of claim 7, wherein
The first coating dispersion comprises 45 to 85% by weight of the binder resin, 5 to 30% by weight of the black fine particles, 5 to 10% by weight of the dispersant and the remaining solvent, and the second coating dispersion is 10 to 30% by weight of the binder resin, black A method of manufacturing a light shielding film having excellent light shielding characteristics, characterized by coating and curing a second coating dispersion comprising 40 to 70 wt% of fine particles, 10 to 15 wt% of a dispersant, and the remaining solvent.

Images