KR20110020133A - Composition for encapsulant, cured products and organic electroluminescent device - Google Patents

Abstract

PURPOSE: An encapsulant composition and a cured product are provided to improve the lifetime of an organic light-emitting device by suppressing the inflow of oxygen and moisture into an organic light-emitting layer. CONSTITUTION: An encapsulant composition comprises a compound represented by chemical formula 1: (R^1)_mSi(OR^)_n and a compound represented by chemical formula 2. In chemical formula 1, R^1 is C1-8 alkyl group having at least one thiol group; R^2 is hydrogen atom, C1-8 alkyl group or aryl group; m+n=4; m is an integer of 1-3; and n is an integer of 1-3. In chemical formula 2, R is one selected from the group consisting of an alkyl group, aryl group, and cycloalkyl group; and k is an integer of 5-1000.

Description

COMPOSITION FOR ENCAPSULANT, CURED PRODUCTS AND ORGANIC ELECTROLUMINESCENT DEVICE}

The present invention relates to a composition for encapsulating material and a cured product used in an organic light emitting device.

Following the liquid crystal display (LCD) and plasma display panel (PDP), the organic light emitting diode (OLED) is a display device attracting attention of the next generation.

The organic light emitting device is a method of forming a positive electrode, an organic material layer, a negative electrode in order on the substrate, by applying a voltage between the positive electrode and the negative electrode to move the electrons and holes to the organic material layer and then recombine to generate light.

On the other hand, the organic material is very vulnerable to moisture and oxygen, the moisture and oxygen infiltrates into the organic light emitting device may act as a factor for reducing the life. Therefore, the encapsulation technology for protecting the organic light emitting layer from the external environment is very important.

Currently, the most commonly used encapsulation technology is a method of covering an encapsulation portion such as an encapsulating glass or a metal can on the top surface of the manufactured organic light emitting device. At this time, the sealant is applied to any one of the substrate region and the encapsulation portion where the organic light emitting layer is not formed, and the encapsulation portion is disposed on the upper surface of the organic light emitting layer to cure the sealant, thereby bonding the substrate and the encapsulation portion.

However, this sealing method is a perfect passivation of the sealant (passivation), when the device is left for a long time, the problem of damaging the device by the inflow of external moisture and oxygen.

In addition, when the organic light emitting layer is encapsulated with a metal can or glass, an external physical shock is transmitted to the lower layer as it is, so that the organic light emitting device is easily damaged.

The present invention improves the life of the organic light emitting device, to provide a composition and a cured material for the encapsulation material that can minimize the physical impact applied from the outside to the organic light emitting layer.

One embodiment of the present invention is a composition for an encapsulant comprising a compound represented by the following formula (1) and a compound represented by the formula (2).

<Formula 1>

(R¹) _m Si (OR²) _n

Wherein R 1 is an alkyl group having 1 to 8 carbon atoms having at least one thiol group, R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, m + n = 4, and m is 1 to 3 Integer, and n is an integer of 1 to 3.)

<Formula 2>

(Wherein, R is any one selected from the group consisting of alkyl group, aryl group, and cycloalkyl group, k is an integer of 5 to 1000.)

Another embodiment of the present invention is that the compound represented by the formula (2) is any one selected from the group consisting of poly dimethyl acrylate (poly dimetyl siloxane acrylate), silicon acrylate (silicon acrylate), and combinations thereof .

Another embodiment of the present invention is 10 to 50% by weight of the compound represented by Formula 1 based on 100% by weight of the composition for encapsulation material; 40 to 85% by weight of the compound represented by Formula 2; 0.1-5% by weight of thermal initiator; And it is a composition for encapsulant comprising a photoinitiator 0.1 to 5% by weight.

Another embodiment of the present invention is a cured product obtained from the composition.

Another embodiment of the present invention is characterized in that the cured product is manufactured by photocuring under the condition that the curing energy is 500 to 3000Mj at 300 to 400nm.

Another embodiment of the present invention is characterized in that the cured product is prepared by thermal curing under the conditions of 50 to 100 ℃.

Another embodiment of the present invention is an organic light emitting device including the cured product.

The composition for the encapsulant and the cured product according to the present invention improve the lifespan of the organic light emitting device by inhibiting moisture and oxygen from flowing into the organic light emitting layer in the organic light emitting device, and absorb and mitigate physical shocks applied from the outside, thereby preventing the impact. The transfer to the organic light emitting layer can be minimized.

According to one embodiment of the present invention, to provide a composition for an encapsulant comprising a compound represented by the formula (1) and a compound represented by the formula (2).

<Formula 1>

(R¹) _m Si (OR²) _n

Wherein R 1 is an alkyl group having 1 to 8 carbon atoms having at least one thiol group, R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, m + n = 4, and m is an integer of 1 to 3 And n is an integer of 1 to 3.

Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group and octyl group.

The aryl group is a phenyl group, tolyl group, 4-cyanophenyl group, biphenyl group, o, m, p-terphenyl group, naphthyl group, anthranyl group, phenanthrenyl group, fluorenyl group, 9-phenylanthranyl group, 9,10- It is a diphenyl anthranyl group and a pyrenyl group.

<Formula 2>

Wherein R is any one selected from the group consisting of an alkyl group, an aryl group, and a cycloalkyl group, and k is an integer of 5 to 1,000.

Specific examples of the alkyl group include methyl, ethyl, propyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, And tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, isicosyl group, hencosyl group and docosyl group.

Specific examples of the aryl group include a phenyl group, tolyl group, 4-cyanophenyl group, biphenyl group, o, m, p-terphenyl group, naphthyl group, anthranyl group, phenanthrenyl group, fluorenyl group, 9-phenylanthranyl group, 9,10- diphenyl anthranyl group, a pyrenyl group, etc. are mentioned.

Specific examples of the cycloalkyl group include cyclopentyl group, cyclohexyl group, norbornane group, adamantane group, 4-methylcyclohexyl group, 4-cyanocyclohexyl group, and the like.

The compound represented by Chemical Formula 2 may be any one selected from the group consisting of polydimethylsiloxane acrylate, polyacrylate, and combinations thereof.

According to another embodiment of the present invention, 10 to 50% by weight of the compound represented by Formula 1 based on 100% by weight of the composition for encapsulation material; 40 to 85% by weight of the compound represented by Formula 2; 0.1-5% by weight of thermal initiator; And it provides a composition for an encapsulant comprising 0.1 to 5% by weight photoinitiator.

The compound represented by Formula 1 includes 10 to 50% by weight based on 100% by weight of the composition for encapsulant, and when the compound represented by Formula 1 is included within the range, speeds up photocuring and improves the degree of curing. The height can be obtained.

The compound represented by Formula 2 includes 40 to 85% by weight based on 100% by weight of the composition for encapsulant, and when the compound represented by Formula 2 is included within the above range, the acrylate of the terminal group is a radical ( radicals) to harden.

The thermal initiator comprises from 0.1 to 5% by weight, preferably from 0.1 to 3% by weight, based on 100% by weight of the composition for encapsulant, the radicals generated by generating radicals when the content of the thermal initiator is within the range The effect of curing by reacting with the compound represented by the formula (2) can be obtained.

The thermal initiator serves as a curing agent for curing the encapsulant composition to form a silicone rubber or resin, and may be used alone or in combination of two or more compounds.

Specific examples of the organic peroxide compound include benzoyl peroxide, t-butyl perbenzoate, o-methylbenzoyl peroxide, p-methylbenzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 1, 1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne, 1,6-bis (p-toluoylperoxycarbonyloxy) hexane and di (4-methylbenzoyl Peroxy) hexamethylene biscarbonate etc. are mentioned.

In addition, specific examples of the azo compound include 2'-azobis (4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis (2,4-dimethyl) valeronitrile, azobis Isobutyronitrile, 2,2'- azobis (2-methylbutyronitrile), etc. are mentioned.

The photoinitiator comprises 0.1 to 5% by weight, preferably 0.1 to 3% by weight based on 100% by weight of the composition for the encapsulant, when the content of the photoinitiator is in the range generated by the radicals generated by light The radical may react with the compound represented by the formula (2) to obtain an effect of curing.

The photoinitiator may be a benzophenone compound, an oxime compound, a phosphine oxide compound, or the like, but is limited thereto. Specifically, as the benzophenone compound, 2-hydroxy-2-methyl-1-phenyl-1-propanone (2-hydroxy-2-methyl-1-phenyl-1-propanone), 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propanone (2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propanone), alpha -Dimethoxy-alpha-phenylacetophenone, 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone ( 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone), 2-methyl-1- [4- (methylthio) phenyl] -2- (4-mol Polyyl) -1-propanone (2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone) and the like.

Examples of the oxime compound include (hydroxyimino) cyclohexane, 1- [4- (phenylthio) phenyl] -octane-1,2-dione-2- (O-benzoyloxime (1- [4- (phenylthio) phenyl] -octane-1,2-dione-2- (O-benzoyloxime)), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -Ethanone-1- (O-acetylroxime) (1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -ethanone-1- (O-acetyloxime)), Triclo Trichloromethyl-triazine derivatives, 4- (4-methoxystyryl) -2,6-trichloromethyl-1,3,5-triazine (4- (4-methoxystyryl) -2 , 6-trichloromethyl-1,3,5-triazine), 4- (4-methoxyphenyl) -2,6-trichloromethyl-1,3,5-triazine (4- (4-methoxyphenyl) -2 , 6-trichloromethyl-1,3,5-triazine), ∝-aminoketone (1- (4-morpholinophenyl) -2-dimethylamino-2-benzyl-butane-1-one (∝-aminoketone (1 -(4-morpholinophenyl) -2-dimethylamino-2-benzyl-butan-1-one) etc. are mentioned.

The phosphine oxide compound may be diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide (diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide), phenyl bis (2,4,6-trimethyl Benzoyl (phenyl bis (2,4,6-trimethyl benzoyl)) and the like.

Meanwhile, the present invention may include a diluent, a plasticizer, an adhesion promoter, an inorganic filler, and an antioxidant.

The diluent serves to lower the viscosity may be 30 parts by weight or less, preferably 0.01 to 30 parts by weight, most preferably 0.05 to 10 parts by weight based on 100 parts by weight of the composition for the sealing material. When the content of the diluent is within the above range, the effect of lowering the viscosity and increasing the degree of curing may be obtained.

Examples of the diluent include (meth) acrylate-based compounds, and specific examples thereof include polyethylene glycol di (meth) acrylate and bisphenol-A di (meth) acrylate, such as ethoxylated bisphenol-A (meth) acrylate. , Tetrahydrofuran (meth) acrylate and di (meth) acrylate, citronellol acrylate and citronellol methacrylate, hydroxypropyl (meth) acrylate, hexanediol di (meth) acrylate, trimethylol Propane tri (meth) acrylate, tetrahydrodicyclopentadienyl (meth) acrylate, ethoxylated trimethylolpropane triacrylate, triethylene glycol diacrylate and triethylene glycol dimethacrylate, isobornyl acrylate And isobornyl methacrylate.

In addition, the non- (meth) acrylic silicone diluent or plasticizer may include 30 parts by weight or less, preferably 1 to 10 parts by weight, based on 100 parts by weight of the composition for encapsulant.

Examples of such non- (meth) acrylic silicones include trimethylsilyl-terminated oils having a viscosity in the range of 100 to 500 mPa · s at 25 ° C., and silicone rubber. The non- (meth) acryl silicone may also include copolymerizable groups such as vinyl groups.

The adhesion promoter serves to modify the curing properties or non-curing properties, based on 100 parts by weight of the composition for the sealing material may be included 20 parts by weight or less, preferably 1 to 10 parts by weight.

Specific examples of the adhesion promoter include (meth) acryloxypropyltrimethoxysilane, trialkyl or triallyl isocyanurate, glycidoxypropyltrimethoxysilane, and the like.

The inorganic filler may be optionally contained within a range that does not reduce the desired level of transparency as it serves to prevent shrinkage of the sheet coated with the composition and to improve scratchability and hardness during the process of preparing the composition for encapsulant into a sheet. Can be added to the composition.

The inorganic filler may be a reinforced silica product, such as smoked silica, and these silica products may be in an untreated hydrophilic form or a treated hydrophobic form.

Examples of the inorganic filler include silica-fume (fume silca), talc (talc), silicon beads (silicon bid), calcium oxide (CaO), barium oxide (BaO), alumina (Al ₂ O ₃ ) and the like. have.

The antioxidant serves to maintain transparency, and may be added to the composition in any amount.

Examples of the antioxidant include butylhydroxytoluene, p-methoxyphenol and the like.

According to another embodiment of the present invention to provide a cured product obtained from the composition for encapsulation material described above.

The cured product may be a photocured product prepared by photocuring under a condition that the curing energy is 500 to 3000Mj at a wavelength of 300 to 400nm, preferably 380nm to 400nm. When manufactured under the above conditions, it is possible to prevent damage to dark spots or light emitting areas.

In addition, the cured product may be a thermoset prepared by thermal curing under the conditions of 50 to 100 ℃, preferably 80 to 100 ℃.

In the case of an organic light emitting device, if the temperature in the manufacturing process is 100 ° C. or more due to heat-vulnerable properties, the organic light emitting device is easily damaged. However, if the temperature is lowered to prevent such damage, the curing time takes too long. Therefore, it is important to cure under an appropriate level of temperature because there is a problem that the productivity and work efficiency are deteriorated.

In the present invention, the cured product may be manufactured within the above temperature range to prevent damage to the optical element due to heat, thereby preventing the problem of lowering productivity and work efficiency.

When using the above-mentioned photocured and thermoset together, the degree of curing can be further improved compared to the case of using the photocured or the thermoset alone.

The cured product according to the present invention prepared under the above-described conditions can be easily cured by heating or ultraviolet rays, can be cured with a thick film due to low shrinkage, and can satisfy the properties required as heat resistance and solvent-free.

According to another embodiment of the present invention, an organic light emitting device including the above-mentioned cured product may be provided. The method of manufacturing the organic light emitting device is a manufacturing method well known in the art to which the present invention will be omitted.

Hereinafter, preferred examples and comparative examples of the present invention will be described. However, the following examples are only preferred embodiments of the present invention and the present invention is not limited to the following examples.

Production Example  1: Preparation of a compound represented by formula (2) according to the present invention

148.5 g of octamethylcyclotetrasiloxane (Samho CNE), 1.5 g of tetramethyltetravinylcyclotetrasiloxane (Samho CNE), 5 g of divinyltetramethyldisiloxane (Samho CNE), (meth) acryloxypropyl 5.4 g of trimethoxysilane ((meth) acryloxypropyltrimethoxysilane (Shin-Etsu) was added to 0.7 ml of sulfuric acid and synthesized at 90 ° C. for 2 hours, followed by removal of moisture using a hygroscopic agent and removal of water generated by condensation reaction using toluene A composite of an average molecular weight of 10,000 could be obtained.

Example  1 to 3

Compound represented by Formula 1 according to the present invention (hereinafter referred to as "Compound (A)"), Compound represented by Formula 2 prepared according to Preparation Example 1 (hereinafter referred to as "Compound (B)"), heat An initiator and a photoinitiator component were prepared as the compounding quantity shown in Table 1 below, and the composition for sealing materials was manufactured. At this time, the content unit of Table 1 is weight%.

The composition for encapsulant prepared according to Examples 1 to 3 was coated on a 0.7 mm glass substrate by spin coating to form a sheet, and then cured by heating at 90 ° C. for 30 minutes to prepare a cured sheet having a thickness of 20 μm. It was.

Example 1 Example 2 Example 3 Compound A ^① 20 30 50 Compound B 74 64 44 Ten initiators ^② 3 3 3 Photoinitiator ^③ 3 3 3

※ ①: In the formula (1) according to the invention R¹ is a propyl group, R² is a phenyl group, m is 2, and n is a compound of 2

②: WACO, v-65

③: Ciba, Irgacure 819

Comparative example  One

(C ₆ H ₅ ) SiO _3/2 units, (CH ₂ = CH) (CH ₃ ) SiO _2/2 units, and (CH ₃ ) ₂ SiO _2/2 units, and (CH ₃ ) _0.65 (C ₆ H ₅ ) 100 parts by mass of an organopolysiloxane resin copolymer (Dow Corning) having an average composition of _0.55 (CH ₂ = CH) _0.25 SiO _1.28 , for all silicon atom-bonded methyl groups, phenyl groups and hydrogen atoms (SiH groups) A mixture containing 20 parts by mass of phenyl groups, 20 parts by mass of phenylmethylhydrogensiloxane having a hydrogen gas yield of 150 ml / g and a viscosity of 10 mPa · s at 25 ° C., and 0.2 parts by mass of ethynylcyclohexanol ( Dow Corning) was added an amount of platinum catalyst sufficient to provide 20 ppm of platinum atoms (Dow Corning) to complete the preparation of the composition. 20 μm was coated and cured by heating at 90 ° C. for 30 minutes.

The adhesive strength, light transmittance, heat resistance, and compression recovery rate of the cured product prepared according to Examples 1 to 3 and Comparative Example 1 were measured by the following method, and the results are shown in Table 2.

(1) Adhesive strength: Tensile strength was measured based on ASTM D1002 using the universal testing machine of INSTRON.

(2) Light transmittance: The transmittance was measured in the visible light region from 400nm to 800nm using a UV-Visible Spectrophotometer.

(3) Heat resistance: Using a thermogravimetric analyzer (TGA, Perkin Elmer, pyris-1) was measured the temperature when the weight of 1g is reduced while increasing the temperature from 50 ℃ to 400 ℃ at a rate of 10 ℃ / min .

(4) Compression recovery rate: The degree of elasticity was evaluated by the recovery rate according to compression using an ultra-compression hardness tester (SHIMADZU Co .: Model [DUH-W201S]). At this time, the force applied during compression is 80mN.

* Recovery ratio B (recovery ratio) = (T-D) / T × 100%

(In the above formula, T is the pattern thickness before compression, and D is the thickness of the pattern recovered after compression.)

Adhesive strength (MPa) Light transmittance (%) (550nm) Heat resistance (℃) Compression Recovery Rate (%) Example 1 3.2 97 324 92 Example 2 4.7 96 361 91.7 Example 3 5.1 95 386 91.4 Comparative Example 1 2.6 94 314 90.8

As shown in Table 2, Examples 1 to 3 was found to be excellent in all of the adhesive strength, permeability, heat resistance and compressive strength compared to Comparative Example 1.

It is understood that the composition for encapsulant of the present invention and the cured product prepared therefrom can be advantageously used as a lens material for protecting, bonding, or changing or adjusting wavelengths of organic light emitting diodes or for light emitting diode elements. Can be.

All simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (7)

A composition for an encapsulant comprising a compound represented by Formula 1 below, and a compound represented by Formula 2. <Formula 1> (R¹) _m Si (OR²) _n Wherein R 1 is an alkyl group having 1 to 8 carbon atoms having at least one thiol group, R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, m + n = 4, and m is 1 to 3 Integer, and n is an integer of 1 to 3.) <Formula 2>

(Wherein, R is any one selected from the group consisting of alkyl group, aryl group, and cycloalkyl group, k is an integer of 5 to 1000.) The method of claim 1, wherein the compound represented by Formula 2 is any one selected from the group consisting of poly dimethyl acrylate (poly dimetyl siloxane acrylate), silicon acrylate (silicon acrylate), and combinations thereof Composition for encapsulant. According to claim 1, 10 to 50% by weight of the compound represented by Formula 1 based on 100% by weight of the composition for encapsulation material; 40 to 85% by weight of the compound represented by Formula 2; 0.1-5% by weight of thermal initiator; And 0.1 to 5% by weight of photoinitiator. Hardened | cured material obtained from the composition of Claim 1. The cured product of claim 4, wherein the cured product is manufactured by photocuring at 300 to 400 nm under conditions of a curing energy of 500 to 3000 Mj. The cured product of claim 4, wherein the cured product is prepared by thermal curing under conditions of 50 to 100 ° C. An organic light emitting device comprising the cured product of claim 4.