KR102363199B1 - Parallax barrier and stereoscopic display apparatus including the same - Google Patents

Abstract

A composite refractive index coating film composition according to an embodiment of the present invention,
a first refractive index material having a refractive index a; and a second refractive index material having a refractive index b that is different from a, wherein an average diameter of the second refractive index material is 20 nm to 1000 nm.

Description

Composite refractive index coating film composition and coating film using the same

The present invention relates to a composite refractive index coating film composition, and more particularly, to a composite refractive index coating film composition applied around a light source of a light emitting device that requires high reflectance and high scattering characteristics at the same time.

In order to efficiently radiate light emitted from the light source in the peripheral portion of the light source of the display device, various types of reflective or scattering layers are formed depending on the type of light source or display device.

In particular, in the case of a self-luminous light source, for example, micro LED, mini LED, OLED (organic LED), QLED (quantum dot led), etc., only a part of the light generated in the light emitting layer is emitted to the outside of the light emitting device. In order to increase the light extraction efficiency, a light extraction structure should be provided.

At this time, as a material of the reflective film used, it is generally considered to use a metallic material, but in the case of a metallic material, electrical conductivity is high, and there are many restrictions on coating and shape. In particular, in the case of a display using a small-sized self-luminous light source, it is necessary to cover the periphery of the light source, so a composite refractive index coating film composition that has a reflective function and a scattering characteristic and has good coating film forming performance by substituting a metal material having restrictions on the coating shape development is required.

An object of the present invention is to provide a composite refractive index coating film composition having high reflectance and high scattering properties at the same time.

At this time, it is also an object of the present invention to provide a composite refractive index coating film composition capable of adding various functions of a composite refractive index reflective lens by adjusting the properties of the first refractive index material and the second refractive index material.

The composite refractive index coating film composition according to the present invention,

a first refractive index material having a refractive index a; and

and a second refractive index material having a refractive index b that is different from a,

The difference between the refractive indices a and b is 0.3 to 1.5, and the second refractive index material has an average diameter of 20 nm to 1000 nm.

In this case, the weight ratio of the first refractive index material to the second refractive index material is 1: 4 to 1: 0.05.

Preferably, a is 1.3 to 1.6, and b is 1.0 to 3.5.

In addition, the second refractive index material may have a thermal conductivity of 1 to 6000, and includes a case in which the second refractive index material is black.

The second refractive index material is at least one material selected from the group consisting of X, or Y or XY, and X is all metals and lanthanides, carbon, Si, B, P, S, and combinations thereof. One or more substances selected from Y may be one or more substances selected from the group consisting of O, N, S, Se, Te, As, C, and combinations thereof.

The first refractive index material may include one or more resins selected from the group consisting of epoxy-based, silicone-based, acrylic-based, and melamine-based resins.

In another configuration of the present invention,

a first refractive index material having a refractive index a; and

A composite refractive index coating film composition comprising a second refractive index material having a refractive index b that is different from a, wherein the difference between the refractive indices a and b is 0.3 to 1.5, and the average diameter of the second refractive index material is 20 nm to 1000 nm There is a composite refractive index coating film having a thickness of 3 to 200 μm and a reflectance of 30% or more by curing.

In addition, the composite refractive index coating film composition according to the present invention,

Board;

an electrode provided on the substrate;

a light emitting device provided on the electrode, and

A composite refractive index coating film composition used in a light emitting device assembly comprising; a composite refractive index coating film provided on the upper surface of the substrate and a side surface of the light emitting device,

The composite refractive index coating film composition may include a first refractive index material having a refractive index a; and

and a second refractive index material having a refractive index b that is different from a,

The second refractive index material has an average diameter of 20 nm to 1000 nm.

also,

The second refractive index material may have a thermal conductivity of 1 to 6000,

The second refractive index material includes a black material.

At this time,

A weight ratio of the first refractive index material to the second refractive index material may be 1:4 to 1:0.05.

When a reflective film is formed with the light scattering coating composition according to an embodiment of the present invention, it has high reflectance and high scattering characteristics at the same time, so solar cells, OLED lighting, OLED display, LED lighting of various sizes and Applicable to LED displays, etc.

1 shows a schematic diagram of a light emitting device assembly.
2 shows a schematic diagram of a light emitting device assembly in which BM is formed.
3 is a photograph of a composition according to Example 1 of the present invention.
4 is a photograph of a composition according to Example 2 of the present invention.
5 is a graph of measuring the reflectivity of Example 1 and Comparative Examples 1 and 2 of the present invention.
6 is a graph measuring the heat dissipation function of the coating film formed of the composition according to Example 6 of the present invention.

Hereinafter, the composite refractive index coating film composition and the manufacturing method thereof according to an embodiment of the present invention will be described in detail as follows.

A composite refractive index coating film composition according to an aspect of the present invention includes a first refractive index material and a second refractive index material.

The first refractive index material is made of a polymer resin comprising a material having a refractive index a of 1.2 to 1.6. In this case, the refractive index is the refractive index after the polymer resin is cured, and the polymer resin used includes one or two or more epoxy-based, silicone-based, acrylic-based, and melamine-based resins.

Bisphenol A type epoxy, Bisphenol F type epoxy, Bisphenol E type, Bisphenol A/F type, Phenol novolac, Phenoxy, Cycloaliphatic epoxy resin, etc. may be preferably used for the epoxy resin, and Methyl Phnyl silicone, Alkyd modified silicone, Methyl Silicone, Phenyl silicone, Silicone polyester, Silicone urethan, Silicone acryl resin, etc. may be preferably used, and the acrylic type may be preferably used with Methacrylate type, Acrylate type, Polyacrylate type, Oligoacrylate type acrylic monomer and oligomer, polyol resin, and melamine type. N-butylated melamine, iso-butylated melamine, methylated melamine, urea-melamine, benzoguanamine resin, etc. can be preferably used.

The second refractive index material is a material having a refractive index b different from that of the first refractive index material, and has a refractive index of 1.4 to 3.5, preferably a refractive index of 1.4 to 3.0, and more preferably a refractive index of 1.4 to 2.8.

The second refractive index material may consist of X, or Y or XY, and X is at least one material selected from the group consisting of all metals and lanthanides, carbon, Si, B, P, S, and combinations thereof, Y is at least one material selected from the group consisting of O, N, S, Se, Te, As, C, and combinations thereof.

At this time, the average diameter of the second refractive index material is 20 nm to 1000 nm, preferably 50 to 1000, more preferably 100 to 800 nm. It has a light reflection effect due to a difference in refractive index within the above range. In this case, the diameter means the average diameter based on D50.

In this embodiment, when the composite refractive index coating film is formed on the surface of the coating film because the average diameter of the second refractive index material is very small, the density and flatness at the interface are very locally improved to scatter the light. At the same time, it is possible to increase the reflectivity.

When there are two or more second refractive indices, stronger scattering can be expected due to the difference in refractive indices.

The shape of the second refractive index material may preferably be a spherical shape, a plate shape, or a flake shape, but is not limited thereto.

The difference (b-a or a-b) between the first refractive index and the second refractive index varies depending on the conditions used, but is preferably 0.1 to 2.1, preferably 0.1 to 1.8, more preferably 0.3 to 1.5.

The weight ratio of the first refractive index material to the second refractive index material is 1:0.05 to 1:4, preferably 1:0.3 to 1:1, more preferably 1:0.3 to 1:0.8.

As described above, by using a material having two refractive indices and controlling the particle size and content of the second refractive index, it is possible to control reflection and refractive index, and to overcome restrictions on coating and shape, unlike a material having a single refractive index.

Meanwhile, when the second refractive index material has a thermal conductivity of 1 to 6000, a heat dissipation function may be additionally provided to the light scattering coating film. In addition, when black is used as the second refractive index material, it may have a reflection function as well as a black matrix function. In this case, the second refractive index material may be, for example, BN (Boron Nitride), graphene, Carbon black, Graphite, Carbon nanotube, Black Silica (Metal doped SiO2), CuO, SiC, Fe3O4, Ag2O, Si, or Diamond. have.

In particular, since the composite refractive index coating composition requires an appropriate thickness to have a necessary reflective function, it is necessary to be prepared in an ink type with low viscosity, so the particle size, type, and the interrelationship between the first and second refractive index materials are important. have meaning

In the case of particles having an average particle size of 1000 nm or more of the second refractive index material, problems such as a decrease in the fill factor of the coating film, sedimentation of particles, and clogging of the nozzle during the process may occur, and in the case of particles having a particle size of 20 nm or less Since problems such as increase in viscosity, dispersibility, and decrease in reflection function occur, the average particle size of the second refractive index material is preferably 20 nm to 1000 nm.

The properties of the composite refractive index coating film also vary depending on the crystal structure of the particle (for example, TiO2 has three phases of Anatase, Rutile, and Brookite, and ZnO has two phases of Wurtzite and Zincblende). At this time, when considering the relationship of the refractive index with the first refractive index and the coating film forming ability, in the case of TiO2, the rutile phase is preferable as the second refractive index material, and in the case of ZnO, the Wurtzite phase is preferable as the second refractive index material.

The shape of the particle is preferably a plate shape for reflection, but it is necessary to properly distribute the shape of the particle in consideration of fairness and dispersibility. For example, it is preferable that the plate-like particles be included in an amount of 5 to 50% by weight, and the spherical particles are included in an amount of 50 to 95% by weight.

On the other hand, the composite refractive index coating film composition according to the embodiment of the present invention may include a solvent and an additive material according to process conditions or needs.

Examples of the solvent include ether-based solvents such as Propylene Glycol Monomethyl Ether (PGME) and Dipropylene Glycol Monomethyl Ether (DGME); ester-based solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; Methyl Alcohol, Ethyl Alcohol, Isopropyl Alcohol, Butyl Alcohol, Methylethylketone (MEK), Methylisobutylketone (MIBK), Acetone ( alcohol-based solvents such as acetone); and cellosolve-based solvents such as Methyl Cellosolve, Ethyl Cellosolve, and Butyl Cellosolve may be selected and used according to the situation.

As the flowability improving agent, siloxane-based additives such as polydimethylsiloxane, polyether modified polydimethylsiloxane, and polymethylalkylsiloxane (alkyl=methyl, ethyl, butyl, etc.) and polyacrylate-based additives such as polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), and polyethyl methacrylate (PEMA).

As the surfactant, a silane-based coupling agent, a titanate-based coupling agent, and an aluminate-based coupling agent may be used, and silicone derivatives and fluorine derivatives may be further included.

On the other hand, the above-described solvent is preferably included in an amount of 20 parts by weight or less based on 100 parts by weight of the first refractive index material. When it exceeds the above range, there may be problems such as sedimentation of the filler and phase separation. In addition, the flowability improving agent is preferably included in an amount of 0.1 to 10 parts by weight. If it exceeds the above range, phase separation between the filler and the resin may occur, and if it is below the above range, the flowability improvement effect may not be sufficient, and thus the dispersibility may be adversely affected. The surfactant is preferably included in an amount of 0.1 to 7 parts by weight. When it exceeds the above range, there are problems such as bubble generation, deterioration of physical properties, and poor curing, and when it is less than the above range, there are problems such as increased viscosity and decreased dispersibility.

The composite refractive index coating film according to another aspect of the present invention includes a coating film including a first refractive index material and a second refractive index material.

The thickness of the coating film according to an embodiment of the present invention is formed in a range of 3 to 200 μm, preferably in a range of 3 to 100, and more preferably in a range of 3 to 80 μm. The reflectance of the composite refractive index coating film composition according to this embodiment may be 30% or more at a wavelength of 550 nm, preferably 30 to 90%, more preferably 30 to 80%, more preferably 30 to 70%.

In this case, the composite refractive index coating film may be formed by a liquid coating method such as spraying, dispensing, inkjet, screen printing, etc. taking an appropriate thickness having reflection.

Another aspect of the present invention is a light emitting device assembly having a composite refractive index coating film. In this embodiment, the light emitting device includes a substrate, a light emitting device, an electrode, and a composite refractive index coating film.

1 shows a schematic diagram of a light emitting device assembly. According to this, the light emitting device is formed on the electrode 20 formed on the substrate 10 . At this time, the composite refractive index coating film 30 is provided on the upper surface of the substrate and the side surface of the light emitting device. The composite refractive index coating film reflects or refracts light emitted from the light emitting device to efficiently extract the light from the light emitting device.

The light emitting device may be OLED, QLED, or micro-LED (micro-LED, mini-LED).

In addition, the light emitting device may optionally further include a black matrix (BM) on the composite refractive index coating film. The black matrix functions to prevent the light emitted from each light emitting device from being mixed with each other. 2 shows a schematic diagram of a light emitting device assembly in which BM is formed.

On the other hand, when the second refractive index material included in the composite refractive index coating film is made of a material such as Al2O3, BN, MgO, or ZnO having good thermal conductivity, it may have a function of dissipating heat generated from the light emitting device.

In addition, when the second refractive index material is black, such as CuO, Graphene, Carbon black, Fe2O3, Ag2O, or Black silica, it is possible to have a black matrix function without forming a separate black matrix.

<Example>

<Example 1> Preparation of composite refractive index coating film composition

A composite refractive index coating composition having a viscosity of 2,000 cPs was prepared by mixing 50 parts by weight of a second refractive index material TiO2 having an average diameter of 500 nm to 100 parts by weight of a methyl silicone resin (first refractive index material).

<Example 2> Preparation of composite refractive index coating film composition

A composite refractive index coating film composition having a viscosity of 2,000 cPs was prepared by mixing 20 parts by weight of a second refractive index material BN having an average diameter of 300 nm to 100 parts by weight of methyl silicone resin (first refractive index material).

<Example 3> Preparation of composite refractive index coating film composition

A composite refractive index coating composition having a viscosity of 2,000 cPs was prepared by mixing 50 parts by weight of a second refractive index material Al2O3 having an average diameter of 1 μm to 100 parts by weight of a methyl silicone resin (first refractive index material).

<Example 4> Preparation of composite refractive index coating film

A coating film was formed to a thickness of 20 μm using the composite refractive index coating film composition of Example 1 described above. The coating film formation method was screen printing.

<Example 5> Preparation of composite refractive index coating film

A coating film was formed to a thickness of 20 μm using the composite refractive index coating film composition of Example 1 described above. The coating film formation method was screen printing.

<Example 6>

A composite refractive index coating composition having a viscosity of 2,000 cPs was prepared by mixing 50 parts by weight of a second refractive index material Al2O3 having an average diameter of 500 nm to 100 parts by weight of methyl silicone resin (first refractive index material), and a 2mm coating film composite refractive index coating film was formed. The coating film formation method was screen printing.

<Comparative example>

<Comparative Example 1> Preparation of composite refractive index coating film composition

A composite refractive index coating film composition having a viscosity of 2,000 cPs was prepared by mixing 50 parts by weight of a second refractive index material TiO2 having an average diameter of 15 nm in 100 parts by weight of methyl silicone resin (first refractive index material).

<Comparative Example 2> Preparation of composite refractive index coating film composition

A composite refractive index coating film composition having a viscosity of 2,000 cPs was prepared by mixing 9.9 parts by weight of a second refractive index material TiO2 having an average diameter of 500 nm in 100 parts by weight of methyl silicone resin (first refractive index material).

<Comparative Example 3> Preparation of composite refractive index coating film

To 100 parts by weight of methyl silicone resin (first refractive index material), 50 parts by weight of TiO2, a second refractive index material having an average diameter of 15 nm, was mixed to form a 20 μm thick composite refractive index coating film. The coating film formation method was screen printing.

<Comparative Example 4> Preparation of composite refractive index coating film

A composite refractive index coating film was prepared by mixing 9.9 parts by weight of a second refractive index material TiO2 having an average diameter of 500 nm in 100 parts by weight of methyl silicone resin (first refractive index material). The coating film formation method was screen printing.

Table 1 is a table summarizing the compositions of the above-described compositions and other additives of the above-described Examples and Comparative Examples.

ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 silicone resin 100 100 100 100 100 Solvent (Poyleneglycol monomethylether) 10 10 5 20 - flow improver
(Polydimethylsiloxane) 5 2 5 5 One Silane coupling agent
(3-Glycidoxypropylmethyldiethoxysilane) 2.5 One 2.5 2.5 0.5 TiO2 500nm 50 9.9 BN 300nm 20 TiO2 15nm 50 Al2O3 1㎛ 50

<Experimental Example> <Experimental Example 1> Measurement of reflectance according to filler content

A coating film was formed with the composite refractive index coating film composition of Example 1 and Comparative Example 1 and Comparative Example 2 to form a thickness of 20 μm, and reflectance according to the filler content was measured by irradiating light of 200 to 800 nm. The reflectivity measurement is shown in FIG. 5 by measuring the reflectance by analyzing the reflected light after irradiating a light beam having an incident angle of 7° to the coating film using an Agilent Cary 5000.

In Comparative Example 1, the reflectance was reduced by 50% or more compared to Example 1 in the wavelength band of 400 to 800 nm, and it is determined that the increase in transmittance due to the decrease in the reflective area is the cause. In Comparative Example 2, the reflectance was decreased in the 400-800 nm wavelength band compared to Example 1.

<Experimental Example 2> Measurement of heat dissipation function

The coating film of Example 6 was shown in FIG. 6 by measuring the thermal conductivity according to the filler content using a hot wire method.

At this time, the hot wire method is a method of measuring the temperature increase curve of the hot wire in contact with the surface of the coating film, and then calculating the thermal diffusivity and thermal conductivity from the curve, and it was calculated by the method of ASTM D7984.

Specifically, since a certain amount of heat from the measurement sensor is absorbed by the surface of the coating film, a certain amount of heat stored on the surface of the surface increases the temperature of the surface of the coating film. At this time, since the rate of temperature increase is inversely proportional to the thermal conductivity of the material, the thermal conductivity was calculated by measuring the time the temperature was increased by flowing about 2-3 ˚C of heat while measuring the sample.

The features, structures, effects, etc. as described above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

Claims (12)

Board;
an electrode provided on the substrate;
a miniature LED (LED) provided on the electrode; and
It includes; a composite refractive index coating film provided on the side surface of the micro LED and the upper surface of the substrate and having a thickness of 20 to 200 μm;
The composite refractive index coating film,
A polymer resin having a refractive index a, and particles dispersed in the polymer resin, having an average particle diameter of 500 to 1000 nm, and having a refractive index b greater than the refractive index a,
Among the particles, 5 to 50% by weight of the plate shape, 50 to 95% by weight of the spherical shape,
The difference between the refractive index a and the refractive index b is 0.3 to 1.5,
The composite refractive index coating film is a light emitting device assembly having a reflectance of 30% or more at a wavelength of 550 nm. According to claim 1,
The miniature LED is a light emitting device assembly that is a micro LED or a mini LED. 3. The method of claim 2,
The refractive index a is 1.3 to 1.6,
The refractive index b is 3.0 or less light emitting device assembly. delete 4. The method of claim 3,
A weight ratio of the polymer resin and the particles is 1:0.05 to 1:4 in a light emitting device assembly. 6. The method of claim 5,
A light emitting device assembly further comprising a black matrix on the composite refractive index coating film. 7. The method of claim 6,
The particles are BN (Boron Nitride), graphene, carbon black, graphite, carbon nanotubes, black silica (Black Silica), TiO ₂ , CuO, SiC, Fe ₃ O ₄ , Ag ₂ O, Si, Al ₂ O ₃ and a light emitting device assembly made of at least one material selected from the group consisting of diamond. 8. The method of claim 7,
The light emitting device assembly wherein the particles are black particles. 8. The method of claim 7,
The particle has a thermal conductivity of 1 to 6000 W / mK light emitting device assembly. 10. The method of claim 9,
The composite refractive index coating film,
A light emitting device assembly provided by curing a composite refractive index coating film composition comprising the polymer resin and the particles. 11. The method of claim 10,
The composite refractive index coating film composition is a light emitting device assembly further comprising a solvent and an additive material. delete

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