KR102351229B1 - resin composition for optical sheet, optical sheet comprising the same and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a resin composition for an optical sheet, an optical sheet comprising the same, and a method for manufacturing the same, and more particularly, a resin composition for an optical sheet that has excellent color reproducibility and reliability as well as reduced thickness and high brightness , to an optical sheet comprising the same, and to a method for manufacturing the same.

Description

A resin composition for an optical sheet, an optical sheet including the same, and a manufacturing method thereof

The present invention relates to a resin composition for an optical sheet, an optical sheet comprising the same, and a manufacturing method thereof, and more particularly, to a resin composition for an optical sheet that has excellent color reproducibility and reliability as well as high luminance, comprising the same It relates to an optical sheet and a method for manufacturing the same.

In an LCD (Liguid Crystal Display) TV that uses a light emitting diode (LED) as a backlight unit (BLU), the LED BLU is one of the most important parts of the LCD TV as it actually emits light.

As a method of forming a white LED BLU, a red color showing a small full width at half maximum (FWHM, the difference between a pair of wavelength values at a position having a value of 1/2 of the maximum value in the relative spectral distribution, in nm) There is a method of forming a white LED BLU by combining (Red, R), green (Green, G), and blue (Blue, B) LED chips.

The method of forming a white LED BLU by combining the red (Red, R), green (Green, G), and blue (Blue, B) LED chips has a large number of LED chips and an additional feedback system is required when realizing white. There is a problem that the manufacturing cost is high.

In addition, there is a method of realizing white color using a combination of a blue LED chip and a yellow (Y) phosphor having a wide emission wavelength at half maximum, which reduces the number of LED chips by 1/3 and makes the feed pack system unnecessary. Accordingly, the cost of BLU production can be significantly reduced. However, due to the use of a phosphor with a large half maximum width, a color filter (CF) that makes the spectrum into red, green, and blue with good color purity was essential. There are problems in that the light extraction efficiency of the device is lowered, and color reproducibility is limited due to poor color purity.

Therefore, recently, research to improve the problem of lowering of light extraction efficiency due to light blocking in a wide area by CF and improve color reproducibility at the same time by replacing conventional phosphors with large half widths with quantum dots with small half widths is being actively pursued.

A quantum dot is a particle in which nano-sized II-IV semiconductor particles form the core. The fluorescence of these quantum dots is light generated when excited electrons descend from a conduction band to a valence band.

In the development of lighting using quantum dot phosphors, quantum dots can emit light of various wavelengths depending on the synthetic material and quantum dot size, and the full width at half maximum of the emission beam can also be adjusted. Due to physical characteristics such as narrow half width and luminous beam of various wavelengths, it is possible to develop not only sunlight-like lighting but also BLU with high color reproducibility.

Among the prior art, Korean Patent Application Laid-Open No. 2012-0088273 discloses a backlight unit and a method for manufacturing the same, which have a clearer color and superior color reproducibility than the case of using a conventional phosphor because quantum dots are used.

On the other hand, when applying the quantum dot phosphor to such an application field, the phosphor generally has a problem in that stability due to oxygen and moisture is inferior. In order to supplement the stability due to such oxygen and moisture, various optical functional films are essential.

Specifically, as described in FIG. 1, the optical sheet usable in the backlight unit is used by laminating the optical functional film 2 on both sides of the quantum dot phosphor 1, and the optical functional film 2 is not only expensive, but also Since there is a problem of loss of luminance, it is urgent to develop an optical sheet usable in a backlight unit that can improve the problems of the optical functional film while improving the stability of the phosphor to oxygen and moisture.

The present invention has been devised to solve the above problems, and the problem to be solved by the present invention is a resin composition for an optical sheet that has excellent color reproducibility and reliability as well as high luminance and thickness reduction, including the same An optical sheet and a manufacturing method thereof are provided.

In addition, the present invention provides a resin composition for an optical sheet capable of improving productivity in manufacturing an optical sheet by simplifying the manufacturing process, an optical sheet including the same, and a manufacturing method thereof.

In order to solve the above problems, the present invention provides a resin composition for an optical sheet comprising a thiol compound represented by the following formula (1) and a compound represented by the following formula (2).

[Formula 1]

In Formula 1, a, b, c, and d are each independently an integer of 1 to 10,

[Formula 2]

In Chemical Formula 2, R ₁ , R ₂ , and R ₃ are each independently a C ₁ to C ₁₀ alkyl group or an alkenyl group.

According to a preferred embodiment of the present invention, the compound represented by Formula 2 and the thiol compound in the resin composition for an optical sheet of the present invention may be included in a weight ratio of 1:1 to 2 by weight.

According to another preferred embodiment of the present invention, the resin composition for an optical sheet of the present invention further includes a photoinitiator, and the photoinitiator may be included in an amount of 1 to 5% by weight based on 100% by weight of the total composition.

According to another preferred embodiment of the present invention, the photopolymerization initiator of the resin composition for an optical sheet of the present invention is benzoin ether, dialkyl acetophenone, or hydroxyl alkylketone. , phenyl glyoxylate, benzyl dimethyl ketal (Benzyl Dimethyl Ketal), acyl phosphine (acyl phosphine) and alpha-aminoketone (α-aminoketone) may include at least one.

Meanwhile, the present invention provides an optical sheet in which a barrier sheet layer, a phosphor layer and an optical layer are sequentially stacked, and the optical layer includes the aforementioned resin composition for an optical sheet.

According to a preferred embodiment of the present invention, the optical layer of the optical sheet of the present invention may have a step pattern formed continuously or discontinuously.

According to another preferred embodiment of the present invention, the step pattern of the optical sheet of the present invention may include one or more selected from a prism pattern, a pyramid pattern, a polygonal pyramid pattern, a micro lens pattern, a cone pattern, and a pattern in which they are mixed. have.

According to another preferred embodiment of the present invention, in the prism pattern of the optical sheet of the present invention, the distance between the upper sides of the neighboring prism patterns may be 48 ~ 72㎛, and the height of the pattern may be 24 ~ 36㎛.

According to another preferred embodiment of the present invention, in the micro lens pattern of the optical sheet of the present invention, the distance between the upper sides of the neighboring micro lens patterns may be 24 to 36 μm, and the height of the pattern may be 12 to 18 μm.

According to another preferred embodiment of the present invention, the lower side of the cone pattern of the optical sheet of the present invention has a hexagonal shape, the distance between the upper sides of the adjacent cone patterns is 40 to 60 μm, and the height of the pattern is 16 to 24 μm.

According to another preferred embodiment of the present invention, the phosphor layer of the optical sheet of the present invention includes a quantum dot phosphor, and the quantum dot phosphor is CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgSe, HgTe. , GaN, GaP, HaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, may include at least one of Si and Ge.

According to another preferred embodiment of the present invention, the barrier sheet layer of the optical sheet of the present invention is at least one of polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polypropylene (PP) and glass. may contain one.

According to another preferred embodiment of the present invention, the barrier sheet layer of the optical sheet of the present invention has an average thickness of 90 to 150 μm, the phosphor layer has an average thickness of 60 to 120 μm, and the optical layer has an average thickness of 3 to It may be 70 μm.

According to another preferred embodiment of the present invention, the optical sheet of the present invention may have a water vapor transmission rate of the optical layer of 1.0 g/m ² ·day or less.

According to another preferred embodiment of the present invention, the optical sheet of the present invention may have a luminance of 19,000 cd/cm ^{2 or} more.

On the other hand, the present invention includes a barrier sheet layer, an optical layer formed on the barrier sheet layer, a phosphor layer including a quantum dot phosphor, and an optical layer formed on the phosphor layer and having a step pattern formed continuously or discontinuously. An optical sheet is provided.

Furthermore, the present invention provides a backlight unit including the above-mentioned optical sheet.

In addition, the present invention provides a liquid crystal display including the backlight unit.

On the other hand, the present invention comprises the steps of (1) applying a metal-organic precursor solution containing quantum dots on top of the barrier sheet layer, (2) UV curing the applied metal-organic precursor solution to form a phosphor layer, ( 3) applying the resin composition for an optical sheet according to any one of claims 1 to 4 on the upper portion of the phosphor layer, and (4) a step pattern continuously or discontinuously formed on the applied resin composition for an optical sheet. It provides an optical sheet manufacturing method comprising the step of forming an optical layer having.

According to a preferred embodiment of the present invention, step (2) of the method for manufacturing an optical sheet of the present invention may be performed in a nitrogen atmosphere of 100 ppm or less oxygen.

The term optical sheet used in the present invention is a sheet through which light passes, and includes all of a light guide sheet, a diffusion sheet, a prism sheet, and a compensating sheet. It is used in a broad sense that includes all.

In addition, the term "sheet" used in the present invention is meant to include all of a plate form, a sheet form, and a film form.

The resin composition for an optical sheet of the present invention, an optical sheet including the same, and a method for manufacturing the same have a thinner thickness than a conventional optical sheet, and have excellent color reproducibility, reliability, and luminance.

In addition, productivity can be improved in manufacturing the optical sheet by simplifying the manufacturing process.

1 is a schematic diagram illustrating a conventional optical sheet.
2 is a schematic diagram illustrating an optical sheet according to a preferred embodiment of the present invention.
3 is a schematic diagram illustrating a prism pattern of the present invention.
4 is a schematic diagram illustrating a micro lens pattern of the present invention.
5 is a schematic diagram illustrating a cone pattern of the present invention.
6 is a schematic diagram illustrating an optical sheet according to another preferred embodiment of the present invention.
7 is a schematic diagram illustrating an optical sheet according to Example 4.

Hereinafter, the present invention will be described in more detail.

As described above, in the development of lighting using quantum dot phosphors, quantum dots can emit light of various wavelengths depending on the synthetic material and quantum dot size, and the full width at half maximum of the emission beam can also be adjusted. Due to physical characteristics such as narrow half width and luminous beam of various wavelengths, it is possible to develop not only sunlight-like lighting but also BLU with high color reproducibility.

However, in applying the quantum dot phosphor to such application fields, the phosphor generally has a problem in that stability due to oxygen and moisture is poor. In order to supplement the stability due to such oxygen and moisture, various optical functional films are essential.

However, since various optical functional films are expensive and have a problem of loss of luminance, it is possible to use in a backlight unit that can improve the problems of the optical functional film while improving the stability of the phosphor to oxygen and moisture. It is an urgent time to develop an optical sheet.

Accordingly, the present invention provides a resin composition for an optical sheet comprising a thiol compound represented by the following formula (1) and a compound represented by the following formula (2) and/or a barrier sheet layer, a phosphor layer and an optical layer are sequentially stacked, The optical layer seeks to solve the above-mentioned problems by providing an optical sheet, characterized in that it includes the resin composition for the optical sheet, and through this, not only has excellent color reproducibility and reliability, but also has high luminance and thickness reduction. It is possible to provide a resin composition for an optical sheet, an optical sheet comprising the same, and a method for manufacturing the same.

In addition, the present invention provides a resin composition for an optical sheet capable of improving productivity in manufacturing an optical sheet by simplifying the manufacturing process, an optical sheet including the same, and a manufacturing method thereof.

The resin composition for an optical sheet of the present invention includes a thiol compound having at least one thiol group and at least one compound represented by Formula 2 below.

First, the thiol compound may include all compounds having at least one thiol group, but preferably may include a thiol compound represented by Formula 1 below.

[Formula 1]

In Formula 1, a, b, c, and d may each independently be an integer of 1 to 10, preferably, a, b, c, and d may each independently be an integer of 1 to 5, and more Preferably, a, b, c, and d may each independently be an integer of 1 to 2.

Next, it may include a compound represented by the following formula (2).

[Formula 2]

In Formula 2, the R ₁ , R ₂ , R ₃ may each independently be a C ₁ to C ₁₀ alkyl group or an alkenyl group, preferably C ₁ to C ₅ It may be an alkyl group or an alkenyl group, and more preferably a C ₁ to C ₃ alkenyl group.

On the other hand, the compound represented by Formula 2 and the thiol compound may be included in a weight ratio of 1: 1 to 2, preferably 1: 1.25 to 1.75 by weight.

The resin composition for an optical sheet of the present invention may be included in the optical layer constituting the optical sheet to be described later. If the thiol compound is included in less than 1 weight ratio with respect to 1 weight ratio of the compound represented by Formula 2, the optical layer has a water vapor transmission rate is increased, the stability of the phosphor layer by oxygen and moisture is deteriorated, and if it is included in an amount exceeding 2 weight ratio, a problem in which the luminance of the optical sheet is deteriorated may occur.

On the other hand, the resin composition for an optical sheet of the present invention may further include a photoinitiator, and the photopolymerization initiator may contain 1 to 5% by weight, preferably 2 to 4% by weight, based on 100% by weight of the total composition,

The photopolymerization initiator serves to sufficiently advance the internal and surface curing of the resin composition for an optical sheet, and various materials that can be used in the art may be used, preferably benzoin ether, dialkylaceto. Dialkyl acetophenone, hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal, acyl phosphine and α-aminoketone may include at least one of

In addition, commercially available photoinitiators may include trade names "Darocur 1173", "Igacure 184", and "Igacure 907" (manufactured by Ciba).

Furthermore, there is provided an optical sheet comprising the above-mentioned resin composition for an optical sheet of the present invention, which will be described in detail with reference to FIG. 2 as follows.

In the optical sheet 100 of the present invention, a barrier sheet layer 10, a phosphor layer 20 and an optical layer 30 are sequentially stacked, and the optical layer 30 includes the aforementioned resin composition for an optical sheet. do.

First, the barrier sheet layer 10 may be formed of a barrier film, preferably the barrier sheet layer 10 is polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), It may be a barrier film comprising at least one of polypropylene (PP) and glass, more preferably at least one of polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polypropylene (PP), and glass. It may be a barrier film formed by coating and depositing a silica-based material on a base including one.

The average thickness of the barrier sheet layer 10 may be 90 to 150 μm, preferably 100 to 130 μm, and if the average thickness is less than 90 μm, manufacturing processes such as meandering and sheet sagging during the optical sheet manufacturing process are impossible. Problems may occur, and when it exceeds 150 μm, the thickness of the optical sheet of the present invention becomes thick, and assembly problems may occur.

Next, the phosphor layer 20 is laminated on the barrier sheet layer 10, and may include a phosphor as a portion that emits light in the optical sheet of the present invention, and preferably has a half width greater than that of the conventional phosphor. It may include a small quantum dot phosphor, so that better color reproducibility may be exhibited.

Specifically, the phosphor layer 20 may have a structure in which a quantum dot phosphor is included in a resin, and the resin may be formed by curing a metal-organic precursor.

The quantum dot phosphor is CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgSe, HgTe, GaN, GaP, HaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, Si and It may include at least one of Ge, but is not limited thereto, and may include nanocrystals of group II-VI or group III-V compound semiconductor group, mixtures thereof, and composites. In addition to this, the quantum dot phosphor may also include non-cadmium quantum dots.

The metal element constituting the metal-organic precursor is lithium (Li), beryllium (Be), boron (B), sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P) , sulfur (S), potassium (K), calcium (Ca), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co) , Nickel (Ni), Copper (Cu), Zinc (Zn), Gallium (Ga), Germanium (Ge), Arsenic (As), Selenium (Se), Rubidium (Rb), Strontium (Sr), Yttrium ( Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), indium (In), tin (Sn), tellurium (Te), antimony (Sb), Barium (Ba), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Gadolinium (Gd), Hafnium (Hf), Tantalum (Ta), Tungsten (W), It may include at least one of iridium (Ir), lead (Pb), bismuth (Bi), polonium (Po), and uranium (U), and these metals are common when the metal-organic precursor is exposed to ultraviolet light or heat is applied. can form a metal oxide thin film.

The average thickness of the phosphor layer 20 may be 60 to 120 μm, preferably 75 to 110 μm, and if the average thickness is less than 60 μm, the luminance decreases and the color coordinates of green and red colors decrease. A problem of lowering may occur, and when it exceeds 120 μm, problems of color coordinate abnormality and cost increase may occur.

Next, the optical layer 30 is a protective layer for protecting the phosphor layer 20 , and may be laminated on the phosphor layer 20 .

Since the optical layer 30 includes the above-mentioned resin composition for an optical sheet, the water vapor transmission rate is low and the stability of the phosphor layer 20 by oxygen and moisture is excellent, and the reliability of the optical sheet 100 of the present invention is excellent. can

Specifically, in order for the optical layer 30 to be used as a protective layer for protecting the phosphor layer 20 like the barrier film layer 10, the water vapor transmission rate is 2.0 g/m ² ·day or less when measured with a water vapor transmission meter. , Preferably it should be 1.0 g/m ² ·day or less, the optical layer 30 of the present invention has a water vapor transmission rate of 1.0 g/m ² ·day or less, preferably 0.8 g/m ² ·day or less, more preferably may be 0.2 g/m ² ·day or less, so that the stability of the phosphor layer 20 by oxygen and moisture is excellent, and thus the reliability of the optical sheet 100 of the present invention may be excellent.

The moisture permeability meter may be used under the brand name "AQUATRAN MODEL 2" manufactured by MOCON.

The optical layer 30 may be formed in a flat plane, or a structured step pattern may be formed.

Specifically, the step pattern may be formed on all or part of the optical layer 30 , and preferably, a structured step pattern may be formed on the upper surface of the optical layer 30 , and the structured step pattern is continuous Or it may be formed discontinuously.

The optical layer may have an average thickness of 3 to 70 μm. If the optical layer is formed in a flat plane, the optical layer may have a thickness of 3 to 30 μm in consideration of moisture permeability, preferably It can be formed in 5 ~ 15㎛. At this time, if the average thickness of the optical layer is less than 3 μm, the moisture permeability increases and it may be difficult to protect the phosphor layer 20, the luminance may decrease, and if it exceeds 30 μm, the thickness increases and the cost increases A problem in which luminance is lowered may occur.

In addition, when the upper surface of the optical layer is formed in a structured step pattern, the optical layer has a structured step pattern formed on the base layer, and the base layer may be formed in a thickness of 3 to 30 μm, and the step pattern is a pattern. It can be formed in different heights depending on the shape of each. The height according to the shape of the step pattern will be described later.

On the other hand, since the step pattern is formed in the optical layer, the luminance and optical function of the optical sheet 100 of the present invention can be further improved, and the luminance when measured with a spectroluminance meter may be ^{19,000 cd/cm 2 or more.}

As the spectroluminance meter, a trade name "CS-2000" manufactured by Minolta may be used.

The step pattern may include at least one selected from a prism pattern, a pyramid pattern, a polygonal pyramid pattern, a micro lens pattern, a cone pattern, and a mixed pattern thereof, preferably a pattern selected from a prism pattern, a micro lens pattern, and a cone pattern can be

The method of forming the step pattern may form the pattern through a roll-to-roll process, an imprinting process, etc. which are general methods used in the art, preferably a roll-to-roll process can be formed through

The average thickness of the optical layer 30 having the step pattern on the upper surface may be 15 to 70 μm, preferably 35 to 45 μm, and if the average thickness is less than 15 μm, it is difficult to protect the phosphor layer 20 In addition, luminance and optical function may decrease, and if it exceeds 70 μm, luminance and optical function may decrease, and a problem of cost increase may occur.

Specifically, when having a prism pattern as the step pattern, as shown in FIG. 3 , the distance between the upper sides of the neighboring prism patterns is 48 to 72 μm, preferably 54 to 66 μm, and the height of the pattern is 24 to 36 μm , preferably 27 to 33 μm.

At this time, if the distance between the upper sides of the neighboring prism patterns is less than 48㎛, there may be a luminance decrease problem, if it exceeds 72㎛, moire may occur, and if the height of the pattern is less than 24㎛, there may be a luminance decrease problem There may be, and if it exceeds 36㎛, there may be a problem of cost increase due to the occurrence of moire and increase in thickness.

In addition, when the micro lens pattern is provided as the step pattern, as shown in FIG. 4 , the distance between the upper sides of the neighboring micro lens patterns is 24 to 36 μm, preferably 27 to 33 μm, and the height of the pattern is 12 to 15 μm, preferably 13 to 14 μm.

At this time, if the distance between the upper sides of the neighboring micro-patterns is less than 24 μm, there may be a problem of luminance degradation, if it exceeds 36 μm, moire may occur, and if the height of the pattern is less than 27 μm, there may be a problem of luminance degradation. There may be, and if it exceeds 33㎛, there may be a problem of moire generation and cost increase due to thickness increase.

In addition, when having a cone pattern as the step pattern, the lower side may have a hexagonal shape as shown in FIG. 5, and the distance between the upper sides of the adjacent cone patterns is 40 to 60 µm, preferably 45 to 55 µm, and the pattern of The height may be 16 to 24 μm, preferably 18 to 22 μm.

At this time, if the distance between the upper sides of the neighboring cone patterns is less than 40㎛, there may be a problem of luminance degradation, if it exceeds 60㎛, moire may occur, and if the height of the pattern is less than 16㎛, there may be a problem of luminance decrease If it exceeds 24㎛, there may be a problem of cost increase due to the occurrence of moire and thickness increase.

On the other hand, according to another preferred embodiment of the present invention, the optical sheet of the present invention is described with reference to FIG. 6, the barrier sheet layer 10', the phosphor layer 20', and the optical layer 30' are sequentially laminated, and the optical layer 30 ′ may include the aforementioned resin composition for an optical sheet, and a structured step pattern may be selectively formed on the lower surface of the optical layer 30 ′.

Specifically, as mentioned above, when the upper surface of the optical layer 30' is flat or has a step pattern, a structured step pattern is selectively formed on the lower surface of the optical layer 30' in contact with the phosphor layer 20'. can have As such, by selectively forming a structured step pattern on the lower surface of the optical layer 30', it is possible to have the effect of preventing moiré, increasing the bonding force between the phosphor layer 20' and the optical layer 30', and improving the luminance. have.

The step pattern formed on the lower surface of the optical layer 30' may be a pattern in which the embossing (a) and the intaglio (b) are repeated, preferably, the pattern may be a rectangular pattern or a trapezoidal pattern, more preferably For example, it may be a trapezoidal pattern. However, the step pattern formed on the lower surface of the optical layer 30' is not limited thereto.

In addition, the upper side or the lower side of the step pattern formed on the lower surface of the optical layer 30 ′ may be formed as a flat surface.

Furthermore, when the step pattern formed on the lower surface of the optical layer 30' is a rectangular pattern, the pitch may be 200 ~ 400㎛, preferably 250 ~ 350㎛, the height is 55 ~ 115㎛, embossed (a) The width of the pattern may be 15 ~ 70㎛, the intaglio (b) the width of the pattern may be 130 ~ 385㎛.

In addition, when the step pattern formed on the lower surface of the optical layer 30' is a trapezoidal pattern, the pitch may be 200 ~ 400㎛, preferably 250 ~ 350㎛, the height is 55 ~ 115㎛, embossed (a) The upper side of the pattern is 15 ~ 35㎛, the lower side of the embossed (a) pattern is 40 ~ 70㎛, the upper side of the intaglio (b) pattern is 175 ~ 385㎛, the lower side of the engraved (b) pattern is 130 ~ It may be 360 μm.

Meanwhile, the present invention provides a backlight unit including the aforementioned optical sheet, and may provide a liquid crystal display including the backlight unit.

On the other hand, the present invention comprises the steps of (1) applying a metal-organic precursor solution containing quantum dots on top of the barrier sheet layer; (2) UV curing the applied metal-organic precursor solution to form a phosphor layer; (3) applying the above-mentioned resin composition for an optical sheet on the upper portion of the phosphor layer; and (4) forming an optical layer having a step pattern formed continuously or discontinuously on the applied resin composition for an optical sheet.

In this case, in the step of forming the phosphor layer in step (2), the phosphor layer may be formed by thermal curing instead of UV curing.

Through such a manufacturing method, the manufacturing method of the present invention can improve productivity by simplifying the manufacturing process compared to the conventional optical sheet manufacturing method.

In addition, the optical layer may have a refractive index of 1.5 or more.

On the other hand, the step (2) may be performed under a nitrogen atmosphere of 100 ppm or less of oxygen, preferably 50 ppm of oxygen or less, and as such is performed under a nitrogen atmosphere, the quantum dot phosphor included in the phosphor layer is activated. Existing moisture and oxygen can be removed, thereby increasing the color gamut and luminance of the manufactured optical sheet.

In addition, in forming the phosphor layer, a general method used in the art may be used, and preferably, it may be formed through a slot die process.

In addition, in forming the phosphor layer on which the pattern is formed or the optical layer having a step pattern on the upper surface, through a roll-to-roll process, an imprinting process, etc., which are general methods used in the art, It can be formed, preferably through an imprinting (imprinting) process.

The present invention will be described in more detail through the following examples, but the following examples are not intended to limit the scope of the present invention, which should be construed to aid understanding of the present invention.

Example

preparation example One

A resin composition for an optical sheet was prepared by mixing a thiol compound represented by the following Chemical Formula 1-1, a compound represented by the following Chemical Formula 2-1, and a photopolymerization initiator (Ciba, Igacrue184).

The compound represented by Formula 2-1 and the thiol compound represented by Formula 1-1 were mixed in a weight ratio of 1:1.5,

3% by weight of the photopolymerization initiator was mixed with respect to 100% by weight of the total composition.

[Formula 1-1]

[Formula 2-1]

preparation example 2

It was prepared in the same manner as in Preparation Example 1, except that the compound represented by Formula 2-1 and the thiol compound represented by Formula 1-1 were mixed in a weight ratio of 1:0.67 to prepare a resin composition for an optical sheet.

preparation example 3

It was prepared in the same manner as in Preparation Example 1, except that the compound represented by Formula 2-1 and the thiol compound represented by Formula 1-1 were mixed in a weight ratio of 1:4.0 to prepare a resin composition for an optical sheet.

preparation example 4

Based on 100% by weight of the total, 45% by weight of epoxy acrylate, 12.5% by weight of urethane acrylate, 40% by weight of acrylate monomer, and 2.5% by weight of photopolymerization initiator (Ciba, Igacrue184) was mixed to prepare a resin composition for an optical sheet.

Example One

As shown in FIG. 2 , in manufacturing the optical sheet, a metal-organic precursor solution containing quantum dots was applied on the barrier sheet layer 10 . The applied metal-organic precursor solution was UV-cured at a UV-A wavelength of 500 mJ under a nitrogen atmosphere of 100 ppm or less of oxygen to form the phosphor layer 20 . At this time, the phosphor layer 20 was coated and cured on the barrier sheet layer 10 in a slot die method.

Next, the resin composition for an optical sheet prepared in Preparation Example 1 is applied on the cured phosphor layer 20 . The optical layer 30 having a prism pattern (see FIG. 3) having a distance between the upper sides of 60 μm and a height of 30 μm through an imprinting process on the resin composition for an optical sheet prepared in Preparation Example 1 applied ) was formed, and UV-cured with a UV-A wavelength of 1000 mJ to prepare an optical sheet.

In this case, the barrier sheet layer 10 was formed by coating and depositing a silica-based material on a base film, and the metal-organic precursor solution was formed by using LA (lauryl acrylate: an acrylic monomer with very little hydrophilicity) as a main monomer ( main monomer), and the quantum dots include either InP or group II to VI semiconductor quantum dots.

In addition, the barrier sheet layer 10 of the manufactured optical sheet had a thickness of 125 μm, the phosphor layer 20 had a thickness of 100 μm, and the optical layer 30 had a thickness of 40 μm. .

Example 2

An optical sheet was prepared in the same manner as in Example 1, except that the resin composition for an optical sheet prepared in Preparation Example 2 was used instead of the resin composition for an optical sheet prepared in Preparation Example 1.

Example 3

An optical sheet was prepared in the same manner as in Example 1, except that the resin composition for an optical sheet prepared in Preparation Example 3 was used instead of the resin composition for an optical sheet prepared in Preparation Example 1.

Example 4

As shown in FIG. 7 , in manufacturing the optical sheet, a metal-organic precursor solution containing quantum dots was applied on the barrier sheet layer 11 . The applied metal-organic precursor solution was UV-cured at a UV-A wavelength of 500 mJ under a nitrogen atmosphere of 100 ppm or less of oxygen to form the phosphor layer 22 . At this time, the phosphor layer 22 was coated and cured on the barrier sheet layer 11 in a slot die method.

Next, the resin composition for an optical sheet prepared in Preparation Example 1 is applied on the cured phosphor layer 20 . The optical sheet was prepared by UV-curing the resin composition for an optical sheet prepared in Preparation Example 1 with a UV-A wavelength of 1000 mJ to form the optical layer 33 .

In this case, the barrier sheet layer 11 was formed by coating and depositing a silica-based material on a base film, and the metal-organic precursor solution was formed by using LA (lauryl acrylate: an acrylic monomer with very little hydrophilicity) as a main monomer ( main monomer), and the quantum dots include either InP or group II to VI semiconductor quantum dots.

In addition, the barrier sheet layer 11 of the manufactured optical sheet had a thickness of 125 μm, the phosphor layer 22 had a thickness of 100 μm, and the optical layer 33 had a thickness of 40 μm. .

Example 5

Manufactured in the same manner as in Example 1, except that when the phosphor layer 20 is formed by thermally curing the applied metal-organic precursor solution, it is carried out under an air atmosphere instead of under a nitrogen atmosphere of 100 ppm or less of oxygen to manufacture an optical sheet did

Example 6

A micro lens having a distance between the upper sides of 30 µm and a pattern height of 15 µm through an imprinting process on the resin composition for an optical sheet prepared in Preparation Example 1 applied, except that it was prepared in the same manner as in Example 1 An optical layer having a pattern (see FIG. 4 ) was formed, and UV-cured at a UV-A wavelength of 1000 mJ to prepare an optical sheet.

Example 7

It was prepared in the same manner as in Example 1, but the lower side was hexagonal through the imprinting process on the resin composition for optical sheets prepared in Preparation Example 1 applied, the distance between the upper sides was 50 μm, and the height of the pattern was An optical layer having a cone pattern (refer to FIG. 5) of 20 μm was formed, and UV-cured with a UV-A wavelength of 1000 mJ to prepare an optical sheet.

comparative example One

An optical sheet was prepared in the same manner as in Example 1, except that the resin composition for an optical sheet prepared in Preparation Example 4 was used instead of the resin composition for an optical sheet prepared in Preparation Example 1.

comparative example 2

As shown in FIG. 7 , in manufacturing the optical sheet, a metal-organic precursor solution containing quantum dots was applied on the barrier sheet layer 11 . The applied metal-organic precursor solution was UV-cured at a UV-A wavelength of 500 mJ under a nitrogen atmosphere of 100 ppm or less of oxygen to form the phosphor layer 22 . At this time, the phosphor layer 22 was coated and cured on the barrier sheet layer 11 in a slot die method.

After applying an adhesive on the phosphor layer 22, a barrier sheet layer 11' was attached to prepare an optical sheet.

At this time, as the barrier sheet layers 11 and 11', a silica-based material coated and deposited on a base film was used, and the metal-organic precursor solution was LA (lauryl acrylate: acrylic monomer with very little hydrophilicity). is used as a main monomer, and the quantum dots include either InP or group II to VI semiconductor quantum dots.

In addition, the barrier sheet layers 11 and 11' of the manufactured optical sheet had a thickness of 125 μm, and the phosphor layer 22 had a thickness of 100 μm.

Experimental example One

The following physical properties were measured for the optical sheets prepared in Examples and Comparative Examples, and are shown in Tables 1 and 2.

(1) Luminance measurement

The luminance of the optical sheet was measured using a spectroluminance meter (Minolta, CS-2000).

(2) moisture permeability measurement

The water vapor transmission rate of the optical layer of the optical sheet was measured using a water vapor transmission meter (MOCON, AQUATRAN MODEL 2).

division Example
One Example
2 Example
3 Example
4 Example
5 luminance
(cd/cm ² ) 20,341 18,998 17,800 19,970 19,582 moisture permeability
(g/m ² day) 0.8
Below 1.5 3.2 0.8
Below 0.8
Below division Example
6 Example
7 comparative example
One comparative example
2 luminance
(cd/cm ² ) 19,300 19,700 20,135 19,001 moisture permeability
(g/m ² day) 0.8
Below 0.8
Below 10.0
More than 0.2

As can be seen in Table 1, it was confirmed that the optical sheet prepared in Example 1 had significantly lower water vapor transmission rate than the optical sheet prepared in Comparative Example 1, and it was confirmed that the luminance was significantly superior to that of the optical sheet prepared in Comparative Example 2 could

In addition, it was confirmed that the optical sheet prepared in Example 1 had superior luminance and lower moisture permeability than the optical sheets prepared in Examples 2 and 3 .

In addition, it was confirmed that the optical sheet manufactured in Example 1 had superior luminance than the optical sheets prepared in Examples 4 and 5, and it was confirmed that the luminance was superior to the optical sheet manufactured in Examples 6 and 7 could

Claims (20)

A barrier sheet layer, a phosphor layer and an optical layer are sequentially stacked,
The optical layer is formed by curing a resin composition for an optical sheet,
The resin composition for an optical sheet comprises an optical sheet comprising a thiol compound represented by the following Chemical Formula 1 and a compound represented by the following Chemical Formula 2-1;
[Formula 1]

[Formula 2-1]

In Formula 1, a, b, c, and d are each independently an integer of 1 to 10.
According to claim 1,
The compound represented by Formula 2-1 and the thiol compound represented by Formula 1 are 1: 1 to 2 weight ratio of the optical sheet.
delete delete delete According to claim 1,
The optical layer has a step pattern formed continuously or discontinuously,
The step pattern is an optical sheet, characterized in that it includes at least one selected from a prism pattern, a pyramid pattern, a polygonal pyramid pattern, a micro lens pattern, a cone pattern, and a pattern in which they are mixed.
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