KR102052359B1 - Encapsulation composition for light emitting diode divice - Google Patents

Abstract

The present invention relates to an encapsulant composition for a light emitting diode device, and more particularly, to an encapsulant composition comprising a silicone resin and a siloxane crosslinking agent, and an encapsulant for a light emitting diode device including the same.
The liquid encapsulation composition of the present invention has the advantage of not only shortening the process time by directly applying to the module, but also foreign matter management. In addition, since the adhesion to the module is high, the blocking of moisture and oxygen in the diode element is improved.
And by using the liquid encapsulation composition, there is a characteristic of heat resistance, cold resistance, stability, high transmittance and yellowing under harsh conditions.

Description

Encapsulation composition for light emitting diode divice

The present invention relates to an encapsulant composition for a light emitting diode device, and more particularly, to an encapsulant composition comprising a silicone resin and a siloxane crosslinking agent, and an encapsulant including the same.

OLED (Organic Light Emitting Diodes) is an element that converts electrical energy into light by applying electric current to organic materials and consists of a structure in which a functional organic material layer is inserted between an anode and a cathode. The electrical characteristics of the device are similar to LEDs (Light Emitting Diodes). After holes are injected from the anode and electrons are injected from the cathode, the holes and electrons move toward each other and then recombine. ), High energy excitons are formed. In this case, as the excitation electrons formed are moved to the ground state, the display technology generates light having a specific wavelength. The advantages of OLED display are spotlighted as the ideal display because it has all the necessary elements such as self-luminous, high-speed response, wide viewing angle, ultra-thin, high definition, durability, and wide temperature range.

  OLED is divided into passive matrix (PM) OLED and active matrix (AM) OLED according to the driving method, and in the case of PM, it is designed to emit light at the intersection point between anode and cathode, which makes it easy to manufacture and can be applied / produced for small and medium products. It is currently produced as a mobile product. In case of AM, each pixel has a TFT that is in charge of driving, so it is easy to realize low power consumption and excellent resolution by driving pixels independently, but it requires 2 ~ 4 TFTs for each pixel, so it has many processes and is complicated for mass production. Although it is difficult, AM OLED can be said to be the most suitable for large size and high resolution display in the future. AM OLED, which has been developed steadily since the mass production of PM OLED, has recently been spreading around the world to establish a solid position as a display, starting with mass production for mobile.

In general, the life of AM OLED requires more than 30,000 hours for TV and 50,000 hours for monitor, but it is announced that it is short compared to the life of PDP or LCD. To compensate for this relative weakness, researchers developing OLED devices are constantly working on extending the lifespan. While research on the life of the product has been attempted to solve the development of the material of the light emitting layer or the common layer, the technology of increasing the light extraction efficiency of AM OLED and encapsulation technology to protect the oxygen and moisture sensitive materials are It is known as a technology that determines success.

There are three ways of encapsulating OLED: encapsulation method using glass / metal can, encapsulation method of thin film, and hybrid encapsulation method using both thin film and glass simultaneously. The method of using glass / metal cans is to attach a moisture absorbent to the inside of a glass or metal can that has been processed to a certain shape, and to fix the can and the device with a photocurable resin. This method is currently being applied to mass production of PM OLED of 2 inches or less. The encapsulation method using a metal can cannot use the front light emitting structure required in AM OLED, and has a disadvantage in that the deformation is severe and the weight is rapidly heavy in proportion to the size of the panel. The encapsulation method using glass cans can be adopted for the front light emitting structure, but as the size of the panel increases, the possibility of damage due to external shock becomes very high. In addition, the existing absorbents are opaque, so in order to apply them to AM OLEDs, a technology to replace them must be developed.

Korean Patent Office Publication No. 10-2011-0014692 (Published February 11, 2011)

Accordingly, the present invention has been made to solve the above problems, the present invention is to provide a liquid sealing material composition for increasing the blocking of water, oxygen, durability, optical properties of the organic light emitting device and shorten the process time. do.

In addition, the present invention is to provide an encapsulant including the encapsulant composition.

The present invention for achieving the above technical problem, provides an encapsulant composition for a light emitting diode device comprising a silicone resin of formula (1) and a siloxane crosslinking agent of formula (2).

According to an embodiment of the present invention, the silicone resin of Chemical Formula 1 is included in the total composition of 55 to 95% by weight, and the siloxane crosslinking agent of Chemical Formula 2 is characterized in that it is included in 4 to 40% by weight of the total composition. .

According to another embodiment of the present invention, the encapsulant composition for a light emitting diode device according to the present invention may further include a hydrogen siliconization catalyst, a curing retardant, an adhesion strengthening agent, and the like.

The hydrogen silicide catalyst may be a metal of Group 8 of the periodic table, a catalyst in which these metals are supported on a carrier of alumina or silica, or a salt or a complex of these metals, and the hydrogen silicide catalyst is 0.01 to 3 weight in the total composition. May be included as a%.

The curing retardant is tris (2,4-di-tert-butylphenyl) phosphite or 1-ethynyl-1-cyclohexanol (1- ethynyl-1-cyclohexanol), and the adhesion enhancing agent may be a silane compound including an alkoxy group.

According to another embodiment of the present invention is characterized in that the encapsulant composition according to the present invention is coated on a light emitting diode device by spin coating, dip coating, inkjet printing, spray coating, screen printing, drop casting, coating or doctor blade. do.

Another aspect of the present invention relates to an encapsulant for a light emitting diode device comprising the encapsulant composition.

The liquid encapsulation composition of the present invention has the advantage of not only shortening the process time by directly applying to the module, but also foreign matter management. In addition, since the adhesion to the module is high, the blocking of moisture and oxygen in the diode element is improved.

And by using the liquid encapsulation composition, there is a characteristic of heat resistance, cold resistance, stability, high transmittance and yellowing under harsh conditions.

In addition, the encapsulant composition of the present invention has a thixotropic property suitable for screen printing.

1 is a graph showing the results of measuring the permeability of the present invention (Examples 1 and 2) and the control group (Comparative Examples 1 and 2).
2 is a scanning electron microscope photograph of the encapsulant of the present invention formed by screen printing an encapsulant composition according to Example 1;
3 is a scanning electron micrograph of the control encapsulant formed by screen printing the encapsulant composition according to Comparative Example 1;
Figure 4 is a graph of the results of measuring the shear stress and viscosity of the present invention encapsulant formed by screen printing the encapsulant composition according to Example 1.
Figure 5 is a graph of the results of measuring the shear stress and viscosity of the present invention encapsulant formed by screen printing the encapsulant composition according to Example 2.

The present invention relates to an encapsulant composition for a light emitting diode device comprising a silicone resin of formula (1) and a siloxane crosslinking agent of formula (2).

[Formula 1]

R ¹ _a SiO _{(4-a) / 2}

In Formula 1, R ¹ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and two of R ¹ The above is a vinyl group and a is 1.90-2.05.

Here, as the unsubstituted or substituted monovalent hydrocarbon group bonded to the silicon atom represented by R ¹ , for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pen Aryl groups, such as phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, phenylethyl group, phenylpropyl group Alkenyl groups such as aralkyl groups, vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, cyclohexenyl groups, octenyl groups, and the like, or some or all of the hydrogen atoms of these groups are fluorine, Substituted by halogen atoms such as bromine and chlorine, cyano groups, and the like, for example, may be chloromethyl group, chloropropyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group and the like, 90 mol% of the total R ¹ It is preferable that the above is a methyl group.

The silicone resin represented by Chemical Formula 1 serves to express coating, filling, and hygroscopic properties when forming an encapsulant, and the content thereof is preferably 55 to 95% by weight in the total composition.

In this case, when the silicone resin is less than the weight, the viscosity is very low, which is not suitable for screen printing. When the silicone resin is more than the weight, the viscosity is very high, and it is difficult to obtain a uniform pattern as well as mesh marks of the screen printing mask.

[Formula 2]

In Formula 2, R is any one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group and a cycloalkyl group, n is an integer of 2 to 1,000.

The siloxane crosslinking agent represented by the formula (2) preferably contains 4 to 40% by weight of the total composition in terms of coating and curing, and when the siloxane crosslinking agent is less than the above weight, sufficient curing does not occur, so the hardness is weak, and the weight When it is exceeded, it becomes flexible without being rigid.

The encapsulant composition for a light emitting diode device according to the present invention may further include at least one selected from the group consisting of a hydrogen silicide catalyst, a curing retardant, and an adhesive strengthening agent.

In the present invention, the hydrogen silicide catalyst acts as a catalyst in curing the silicone resin through hydrogen silicide reaction, for example, a metal of Group 8 of the periodic table, or the metal is supported on a carrier such as alumina or silica. It may be a catalyst or a salt or a complex of the metal. Platinum, rhodium, palladium, ruthenium, iridium, or a combination thereof may be used as the metal of Group 8 of the periodic table, and platinum may be preferably used. The hydrogen silicide catalyst is not particularly limited in content, but preferably may be included in 0.01 to 3% by weight of the total composition.

This hardening reaction does not occur when the hydrogen silicide catalyst is added below the weight. When the hydrogen silicide catalyst is added above the weight, it hardens during stirring and hardens.

In the present invention, the curing retardant is not particularly limited in kind, phosphite-based or acetylene-based may be used, preferably tris (2,4-di- tert-butylphenyl) phosphite (tris (2,4-di-tert-butylphenyl) phosphite) or 1-ethynyl-1-cyclohexanol can be used.

In the present invention, the adhesion strengthening agent is not particularly limited, but may be used a silane compound containing an alkoxy group, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 2 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane (3-methacryloxypropylmethyldiethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-chloropropyl tree 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane (3- isocyanatepropyltriethoxysilane) and the like can be used.

The encapsulant composition of the present invention affects inert fillers, reinforcing or non-reinforcing fillers, fungicides, paints, rheological additives, corrosion inhibitors, oxidation inhibitors, light stabilizers, flame retardants, and electrical properties within a range that does not impair the purpose of use. Additives such as agents, dispersants, solvents, binders, pigments, dyes, plasticizers, organic polymers, heat stabilizers, nanoparticles of oxides or nitrides, flame retardants, heat resistant agents, leveling agents and the like.

The encapsulant composition may be directly coated on a light emitting diode device by a solution process, and specifically, may be coated by spin coating, dip coating, inkjet printing, spray coating, screen printing, drop casting, coating, or a doctor blade.

The present invention also provides an encapsulant for a light emitting diode device comprising the encapsulant composition.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the content of the present invention is not limited to the scope of the present invention.

Example  1 to 2: Encapsulant  Preparation of the composition

The raw materials shown in Table 1 were mixed and stirred to prepare an encapsulant composition according to the present invention.

Example 1 Example 2 Silicone resin (wt%) 80 70 Siloxane crosslinker (wt%) 18 28 Hydrogen Silicate Catalyst (wt%) 0.1 0.1 Leveling agent (wt%) 0.5 0.5 Curing retardant (wt%) 0.4 0.4 Adhesion Enhancer (wt%) One One Total (wt%) 100 100

-Silicone Resin: Vinyl Silicone Polymer (viscosity 100K cps, 10K cps) / MQ Korea

-Siloxane crosslinker: Hydrogen Silicone Polymer / MQ Korea

-Hydrogen Silicate Catalyst: platinum (0) and divinyltetramethyldisiloxane / MQ Korea

-Leveling agent: acrylate resin / public company

-Curing retardant: Tris (2,4-di-butylphenyl) phosphite / Sigma Aldrich

-Adhesive Strengthening Agent: Silane Coupling Agent (Vinyl Trimethoxysilane) / Shin-Etsu

Comparative example  1 to 2: Encapsulant  Preparation of the composition

To prepare a control encapsulant composition by mixing and stirring the raw materials shown in Table 2 below.

Comparative Example 1 Comparative Example 2 Epoxy resin (wt%) 76 75 Curing agent (wt%) 3 3 Additive (wt%) One One Inorganic filler (wt%) 10 11 Thiol Compound (wt%) 10 10 Total (wt%) 100 100

-Epoxy Resin: Bis A epoxy (YDF 128) / Kukdo Chemical

-Curing agent: imidazole series curing agent (2PZCN) / Ildong Chemical

Additive: Silane coupling agent (B307) / BYK

-Inorganic filler: magnesium oxide powder (Talc) / Korea Pearl Industry Co., Ltd.

-Thiol compounds: Menta-8-thiol-3-one / Sigma Aldrich Korea

Example  3: light emitting diode element Encapsulant  Produce

The encapsulant composition prepared according to Examples 1 to 2 and Comparative Examples 1 to 2 was directly coated on the device in the OLED by the screen printing method, molded into a sheet, and then heated and cured at 100 ° C. for 2 hours, and the thickness was 10 μm. The light emitting diode element containing the sealing material layer of was obtained.

Experimental Example  1: of encapsulant Light transmittance  Measure

The transmittance of the encapsulant for the LED device manufactured in Example 3 was measured in the visible light region of 300 nm to 800 nm using a UV-Visible Spectrophotometer. (Figure 1)

As shown in FIG. 1, the encapsulant obtained by curing the encapsulant composition of the present invention has a light transmittance of 100% or more, confirming that transparency can be ensured. From these results, the encapsulant of the present invention is expected to be applicable to a double-sided light emitting display device because it does not block light and has excellent light transmittance.

Experimental Example  2: of encapsulant Yellowing  Index measurement

The yellowing index of the light emitting diode device encapsulation material prepared in Example 3 was measured using a Spectrophotometer CM-3700d manufactured by Konica Minolta. Table 3

Yellow Index (YI) Example 1 0.05 Example 2 0.04 Comparative Example 1 0.14 Comparative Example 2 0.15

As shown in Table 3, the encapsulant of the present invention was confirmed that the yellowing phenomenon is significantly improved compared to the control encapsulant.

Experimental Example  3: surface of encapsulant Morphology  Measure

For the light emitting diode device encapsulation material prepared in Example 3, the pattern shape was measured using an optical microscope to measure surface morphology, and the results are shown in FIGS. 2 and 3.

2 and 3 shows that the encapsulant of the present invention (FIG. 2) exhibits uniform surface properties as compared to the control encapsulant (FIG. 3), and the encapsulant of the present invention has good pattern straightness and is suitable for screen printing. have.

Experimental Example  4: measurement of shear stress and viscosity of encapsulant

The viscosity of the light emitting diode device encapsulation material manufactured in Example 3 was measured according to frequency using a rheometer of TA, and the thixotropy index value (shear stress, viscosity) was used. Was calculated. The results are shown in FIGS. 4-5 and Tables 4-5.

Encapsulant prepared by curing the encapsulant composition of Example 1 Shear stress (Pa) Shear rate (1 / s) Viscosity (Pas) Time (s) 191.4 2.759 69.38 2.012 429.7 6.314 68.06 4.036 614.1 9.07 67.71 6.012 831 12.45 66.74 8.032 1028 15.82 64.97 10.016 1202 19.2 62.61 12.024 1383 22.57 61.25 14.02 1641 25.94 63.27 16.02 1819 29.3 62.09 18.016 1987 32.65 60.86 20.016 2238 36.01 62.15 22.02 2330 39.36 59.2 24.02 2568 42.71 60.14 26.016 2638 46.05 57.27 28.02 2871 49.41 58.1 30.016 2969 52.75 56.28 32 3084 56.1 54.97 34.02 3252 59.44 54.71 36.016 3406 62.79 54.24 38.02 3532 66.13 53.42 40.004 3664 69.48 52.73 42.016 3709 72.82 50.94 44.02 3716 76.16 48.79 46.016 3763 79.52 47.32 48.016 3653 82.86 44.08 50.02 3599 86.19 41.76 52.02 3360 89.51 37.53 54.02 3317 92.87 35.72 56.016 3094 96.19 32.17 58.02 2882 99.19 29.05 60.016

Encapsulant prepared by curing the encapsulant composition of Example 2 Shear stress (Pa) Shear rate (1 / s) Viscosity (Pas) Time (s) 67.76 2.721 24.91 1.992 152.5 6.251 24.4 4.012 218.2 9.674 22.55 6.008 297.3 12.4 23.97 8.008 374 15.78 23.7 10.008 444.7 19.16 23.21 12.012 511.5 22.52 22.71 14.008 587.8 25.87 22.72 16.008 676.7 29.23 23.15 18.008 748.9 32.58 22.99 20.008 822.6 35.93 22.89 22.004 888.1 39.28 22.61 24.008 960.3 42.63 22.53 26.008 1024 45.98 22.28 28.008 1103 49.32 22.35 30.008 1159 52.67 22.01 32.008 1230 56.02 21.95 34.008 1295 59.36 21.82 36.008 1338 62.7 21.34 38.008 1394 66.05 21.1 40.008 1483 69.39 21.37 42.008 1504 72.74 20.68 44.008 1577 76.07 20.73 46.004 1650 79.42 20.78 48.008 1715 82.77 20.72 50.008 1740 86.1 20.21 52.004 1812 89.45 20.26 54.008 1817 92.78 19.59 56.004 1884 96.08 19.61 58.008 1949 99.11 19.66 60.008

Experimental Example  5: encapsulation material Thixotropic  Coefficient measurement

The viscosity of the light-emitting diode device encapsulation material prepared in Example 3 was measured using a Rheologymeter of TA, and the thixotropy index (TI) was calculated using the following equation. The results are shown in Table 6.

T.I = [viscosity at x RPM / viscosity at 10x RPM]

x is 1 to 5

In general, considering that T.I suitable for screen printing is 1.2 or less, it can be seen that the encapsulant of the present invention is a material suitable for screen printing.

Thixotropic coefficient (TI) Example 1 1.097 Example 2 1.076 Comparative Example 1 Not measurable Comparative Example 2 Not measurable

As shown in Table 6, the encapsulant prepared by the composition of Example 1 had a thixotropic value of 1.097, which was calculated from the viscosity of 2.759 and 25.94, and the encapsulant prepared by the composition of Example 2 had a shear rate of 2.721 and 25.87. The thixotropic value calculated by viscosity was 1.076, and it was confirmed that the encapsulant of the present invention had a thixotropic property.

Claims (12)

Silicone resin of formula 1 and siloxane crosslinking agent of formula 2,
Silicone resin of Formula 1 is included in 70 to 80% by weight of the total composition,
The siloxane crosslinking agent of Formula 2 is included in 18 to 28% by weight of the total composition,
Encapsulant composition for light emitting diode elements.
[Formula 1]
R ¹ _a SiO _{(4-a) / 2}
(In Formula 1, R ¹ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, at least two of R ¹ are vinyl groups, and a is 1.90 to 2.05.)
[Formula 2]

(In Formula 2, R is any one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group and a cycloalkyl group, n is an integer of 2 to 1,000.) delete delete The encapsulation composition of claim 1, wherein the composition further comprises at least one selected from the group consisting of a hydrogen siliconization catalyst, a curing retardant, and an adhesion strengthening agent. The encapsulant for a light emitting diode element according to claim 4, wherein the hydrogen silicide catalyst is a metal of Group 8 of the periodic table, a catalyst having these metals supported on a carrier of alumina or silica, or a salt or a complex of these metals. Composition. The encapsulant composition for a light emitting diode device according to claim 5, wherein the metal of Group 8 of the periodic table is platinum. The encapsulant composition for a light emitting diode device according to claim 4, wherein the hydrogen silicide catalyst is included in an amount of 0.01 to 3% by weight in the total composition. The method of claim 4, wherein the curing retardant is tris (2,4-di-tert-butylphenyl) phosphite or 1-ethynyl-1- Cyclohexanol (1-ethynyl-1-cyclohexanol) It is a sealing material composition for light emitting diode elements characterized by the above-mentioned. The encapsulant composition for a light emitting diode device according to claim 4, wherein the adhesion strengthening agent is a silane compound containing an alkoxy group. 10. The method of claim 9, wherein the silane compound is vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane , 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane (3- acryloxypropyltrimethoxysilane), 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mer An encapsulant composition for a light emitting diode device, characterized in that it is selected from the group consisting of 3-mercaptopropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane. The encapsulation composition of claim 1, wherein the encapsulant composition is coated on the light emitting diode device by spin coating, dip coating, inkjet printing, spray coating, screen printing, drop casting, coating, or a doctor blade. Ash composition. An encapsulant for a light emitting diode device comprising the encapsulant composition of any one of claims 1 and 4 to 11.

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