KR101601887B1 - Led encapsulant containing ultra-fast curing epoxy-based polysiloxane resin and manufacturing method of epoxy-based polysiloxane resin - Google Patents

Abstract

The present invention relates to an LED encapsulant made of an ultra-high-speed curing epoxy-based polysiloxane resin and a method for producing the resin.
The present invention relates to an epoxy-based polysiloxane resin which is thermally cured by using an epoxy resin having excellent refractive index and transparency, but is resistant to yellowing at a high temperature and has a short curing time, The resin is useful as an LED encapsulant having improved physical properties by maintaining a high refractive index and high transparency even at a high temperature, particularly securing heat resistance and providing an extremely fast curing time of 60 minutes or less.

Description

TECHNICAL FIELD [0001] The present invention relates to an LED encapsulant made of an ultra-high-speed curing epoxy-based polysiloxane resin and a method for manufacturing the same. [0001] The present invention relates to an LED encapsulant,

The present invention relates to an LED encapsulant made of an ultra-high-speed curing epoxy-based polysiloxane resin and a method for producing the resin, and more particularly, to an LED encapsulant made of an epoxy resin having excellent refractive index and transparency, Fast curing type epoxy-based polysiloxane resin obtained by thermosetting an aromatic group anhydride curing agent which is resistant to development and has a short curing time, and a method for producing the resin.

BACKGROUND ART Light emitting diodes (hereinafter referred to as "LEDs") have attracted much attention not only in research fields but also in industrial fields due to their energy efficiency and durability.

Thus, the LED for emitting white light by combining the sealed inner precursor and the LED chip can be classified into a type using a yellow precursor and a blue LED chip, a type combining red, green and blue LED chips and a red, green, and blue precursor There is a type that uses UV LED chip with.

In general, encapsulant resin is used not only to protect the LED chip but also to obtain white light. Thus, the encapsulant resin should have good transparency in the visible light range and be stable to heat, moisture, solvent, and chemical resistance.

In particular, heat radiation from the LED chip increases the temperature of the LED packaging to cause yellowing and reduces the light efficiency by inhibiting the transmittance. Therefore, the encapsulant resin is excellent in high temperature It should have thermal stability.

In addition, since the refractive index of the LED chip is generally 2.0 or more, the encapsulant resin is required to have a refractive index close to or higher than that of the LED chip for effective light emission.

In recent years, hybrid materials based on oligosiloxanes made of sol-gel exhibit high transparency and relatively high thermal stability compared to conventional polymers, and thus they have been applied to optical applications [ Chem . Mater ., 1995, 7 , 2010, Lightwave . Techol . 1998, 16 , 1049].

In general, organic-inorganic nanohybrid materials (also referred to as hybrimers) prepared by a sol-gel process are prepared by precisely controlling the size and distribution of oil-and-inorganic constituents in their preparation, Characteristics can be obtained.

In this regard, nano-sized organo oligosiloxanes synthesized by simple sol-gel reactions of organosilanes as inorganic structures are suitable for hybridization. Thus, epoxy based hybrids using sol-gel reactions have been extensively studied in fields such as nano-imprinting, protective films and wave guides.

Epoxy resins have been widely used in the industry due to their excellent refractive index and transmittance, cost-effectiveness due to rapid processing time and excellent mechanical properties, and these advantages have been used for many years as LED encapsulants.

However, the use of high intensity blue light to achieve a high output white LED has resulted in an increase in discoloration (yellowing) of the epoxy encapsulant. As a high-power white LED encapsulant, silicon resin showing high heat resistance is used instead of conventional epoxy resin because of low thermal stability against yellowing.

However, the conventional phenylsilicone resin has a relatively high refractive index of 1.53, resulting in a limited light emission efficiency of the LED, and a rapid curing time is required according to the conventional epoxy-based encapsulant cured within one hour.

The present inventors have made efforts to solve the problems of the conventional LED encapsulant. As a result, they have improved the disadvantages of the epoxy resin used as the conventional LED encapsulant and the recently introduced silicone resin, The present inventors have completed the present invention by providing an ultrahigh-speed curing epoxy-based polysiloxane resin which is resistant to heat and curing with an anhydrous curing agent of an aromatic group having a short curing time and confirming that the resin satisfies the physical properties required for the LED encapsulant .

It is an object of the present invention to provide an LED encapsulant made of a high-speed curing epoxy-based polysiloxane resin which maintains high transparency at high temperatures and high transparency.

Another object of the present invention is to provide a method for producing an ultrahigh-speed curing epoxy-based polysiloxane resin satisfying physical properties required for an LED encapsulant.

In order to achieve the above object, the present invention provides an encapsulant for an LED comprising an epoxy oligosiloxane and an anhydride curing agent of an aromatic group formed by an ultra-fast curing epoxy-based polysiloxane resin obtained by thermosetting.

The aromatic group anhydride curing agent can be cured within 60 minutes while maintaining transparency under a curing condition of 120 to 180 캜. Preferred examples of the anhydride curing agent of the aromatic group include phthalic anhydride or 4,4 ' - (4,4'-isopropylidene diphenoxy) bis (phthalic anhydride).

The ultrahigh speed curable epoxy-based polysiloxane resin as the encapsulant for LED of the present invention satisfies (1) a refractive index of 1.50 or more, (2) a transmittance of 90% or more, and (3) a curing time of 60 minutes or less.

In addition, the ultra-high-speed curing epoxy-based polysiloxane resin of the present invention satisfies heat resistance of 15% or less in transmittance change for at least 48 hours at a temperature of 120 ° C.

Furthermore, the present invention is a polysiloxane resin of the high-speed curing type epoxy-based, SiO ₂ Nanoparticles, TiO ₂ nanoparticles, or Si nanoparticles can be further incorporated. In the case of the resin in which the nanoparticles are incorporated, the refractive index of the resin can be controlled according to the refractive index of the nanoparticles. However, maintain.

Specifically, the ultra-high-speed curing epoxy-based polysiloxane resin is coated with SiO _{2 having a} refractive index of 1.50 or less The nanoparticle-impregnated resin is provided as a flexible resin due to (1) high refractive index of 1.50 or higher and (2) high transparency of 90% or higher transmittance and lowered hardness.

The present invention provides a process for preparing an epoxy-based polysiloxane resin which is carried out according to the following Reaction Scheme 1.

More specifically, an epoxy-oligomer silane (2) is synthesized by sol-gel reaction between an organoalkoxysilane (3) containing an epoxy group and an organosilane diol (4) The anhydrous curing agent of the group is thermally cured at 120 to 180 DEG C to prepare an epoxy-based polysiloxane resin (1).

Scheme 1

In the above, R ₁ to R ₃ are each a linear or branched C ₁ to C ₇ alkyl group.

In the above production process, the curing agent used in the thermosetting reaction is preferably an aromatic group anhydride curing agent, more preferably a phthalic acid anhydride or 4,4 '- (4,4'-isopropylidenepiperoxy) bis (Phthalic anhydride) is used.

The present invention, in the manufacturing method described above, when thermal curing reaction SiO ₂ Nanoparticles, TiO ₂ Nanoparticles or Si nanoparticles in a dispersed solution to provide an ultra-fast curing epoxy-based polysiloxane resin in which nanoparticles are incorporated.

In the present invention, epoxy resin having excellent refractive index and transparency is used, and when an aromatic group anhydride curing agent is used, the curing time can be remarkably shortened compared with the case of using a non-aromatic group curing agent and high transparency and high transparency A high-speed curing epoxy-based polysiloxane resin can be provided.

Thus, the LED encapsulant made of the ultra-high-speed curing epoxy-based polysiloxane resin of the present invention can maintain the refractive index and transparency at a high temperature while complementing the disadvantages of each of the epoxy resin and the silicone resin used as the conventional LED encapsulant, Can be minimized.

In addition, the present invention can provide a method for producing an ultrahigh-speed curing epoxy-based polysiloxane resin which is carried out under optimal conditions to satisfy the above physical properties.

1 is a result of measuring the hardness of epoxy-based polysiloxane resin according to Example 1 of the present invention over time
Fig. 2 is a photograph of the transmittance evaluation result and the light transmittance spectrum of the epoxy-based polysiloxane resin of Fig. 1,
FIG. 3 shows the results of measuring the hardness of the epoxy-based polysiloxane resin containing nanoparticles according to Example 3 of the present invention,
FIG. 4 is a photograph of a transmittance evaluation image and a light transmittance spectrum of the epoxy-based polysiloxane resin containing the nanoparticles of FIG. 3,
5 is a comparative analysis result of the infrared spectrum of the epoxy-based polysiloxane resin prepared in Example 2 of the present invention,
6 is a graph illustrating the refractive index change of the epoxy-based polysiloxane resin prepared in Example 2 of the present invention,
Figure 7 shows the results of thermogravimetric analysis (TGA) of the epoxy-based polysiloxane resin prepared in Example 2 of the present invention,
Fig. 8 shows the heat resistance evaluation results of the epoxy-based polysiloxane resin of the present invention with or without nanoparticle impregnation.

Hereinafter, the present invention will be described in detail.

The present invention provides an encapsulant for an LED comprising an epoxy oligosiloxane and an anhydrous curing agent of an aromatic group, which is obtained by thermosetting an ultrahigh speed curing epoxy based polysiloxane resin.

Accordingly, the present invention relates to an epoxy resin composition which is excellent in yellowing resistance while maintaining a high refractive index and high transmittance, and particularly, an anhydrous curing agent of an aromatic group satisfying the requirement that the curing time is less than 60 minutes, more preferably less than 30 minutes .

In an embodiment of the present invention, as a preferable example, a phthalic anhydride of the following formula (1) or 4,4 '- (4,4'-isopropylidene diphenoxy) bis (phthalic anhydride) of the formula However, it is possible to use an anhydrous curing agent of an aromatic group which is cured at an extremely high speed within 60 minutes while transparency is maintained under a curing condition of 120 to 180 캜.

Formula 1

Formula 1

The phthalic anhydride represented by Formula 1 is an aromatic group anhydride having a melting point (131 ° C) lower than the curing temperature (150 ° C). The low melting point secures transparency in the curing step, The influence of the refractive index is enhanced. In the examples of the present invention, the curing reaction was carried out at a curing temperature of 120 ° C. and a curing time of 60 minutes. As a result, it was found that an epoxy-based resin having high transmittance and high refractive index and satisfying excellent heat resistance at 120 ° C. for at least 48 hours To provide a polysiloxane resin.

The 4,4 '- (4,4'-isopropylidene diphenoxy) bis (phthalic anhydride) represented by the above formula (2) is an anhydride having four aromatic groups in the form of a straight chain and has a melting point of 184-187 ° C. to be. In this structure, since there are two sites that can be connected to the epoxy group, it is advantageous in improving the refractive index because of good bonding properties and several aromatic groups. In the embodiment of the present invention, the curing temperature is maintained at a curing temperature of 180 캜 in consideration of the melting point, and as a result, quick curing within 30 minutes can be confirmed.

(1) a refractive index of at least 1.50, (2) a transmittance of 90% or more, and (3) a curing time of 60 minutes or less, obtained by thermosetting with an aromatic group anhydride curing agent.

The present invention, the polysiloxane resin of the high-speed curing type epoxy-based in order to determine whether or not to preserve by the incorporation of nano-particles in the cured physical properties of the epoxy polysiloxane-based resin, SiO ₂ Nanoparticles, TiO ₂ nanoparticles, or Si nanoparticles.

Thus, in the embodiment of the present invention, the ultra-high-speed curing type epoxy-based polysiloxane resin is coated with SiO _{2 having a} refractive index of 1.50 or less and 1.46 Thereby providing a resin in which nanoparticles are embedded.

As a result of evaluating the physical properties of the resin, it was found that SiO _{2 having a} refractive index of 1.46 The refractive index of the resin obtained by the incorporation of the nanoparticles shows a value lower than the refractive index of the original resin, so that the refractive index of the final resin can be controlled according to the embedded nanoparticles.

That is, the ultra-fast curing epoxy-based polysiloxane resin of the present invention can control the refractive index of the final resin according to the refractive index of the nanoparticles while maintaining the refractive index and transparency of the initial resin by further incorporating nanoparticles having different refractive indexes.

Thus, in the embodiment of the present invention, SiO _{2 having a} refractive index of 1.46 The epoxy-based polysiloxane resin in which nanoparticles are incorporated can provide a flexible resin by lowering the hardness while maintaining the refractive index and transparency.

The present invention provides a process for preparing an epoxy-based polysiloxane resin which is carried out according to the following Reaction Scheme 1.

More specifically, an epoxy-oligomer silane (2) is synthesized by sol-gel reaction between an organoalkoxysilane (3) containing an epoxy group and an organosilane diol (4) The anhydrous curing agent of the group is thermally cured at 120 to 180 DEG C to prepare an epoxy-based polysiloxane resin (1).

Scheme 1

(Wherein R ₁ to R ₃ are each a linear or branched C ₁ to C ₇ alkyl group)

In the above production process, the curing agent used in the thermosetting reaction is preferably an aromatic group anhydride curing agent, more preferably a phthalic acid anhydride or 4,4 '- (4,4'-isopropylidenepiperoxy) bis (Phthalic anhydride) is used.

The present invention is the heat curing reaction in the method for producing the SiO _2, Nanoparticles, TiO ₂ Nanoparticles or Si nanoparticles in a dispersed solution to provide an ultra-fast curing epoxy-based polysiloxane resin in which nanoparticles are incorporated.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This is for further illustrating the present invention, and the scope of the present invention is not limited to these examples.

Example 1 Synthesis of Epoxy-Based Polysiloxane Resin 1

Step 1: Synthesis of diphenylsilanediol (DPSD)

Scheme 1-1

In a 2000 ml flask, 800 ml of distilled water and 50.4 g (0.6 mol) of NaHCO ₃ were added and stirred to dissolve completely. 76 g (0.3 mol) of dichlorodiphenylsilane was then added using the syringe. Immediately after the addition, a white precipitate began to be generated and stirred for 1 hour to react sufficiently. 1000 ml of diethyl ether was then added and stirred to dissolve all of the white sediments. When all of the sediment was dissolved, stirring was stopped and the aqueous layer was removed by transferring to a separating funnel, and anhydrous MgSO ₄ was added to remove residual water. Then, only the solution was obtained by filtration, and the solvent was removed by evaporation under reduced pressure to obtain a white product. 1 L of toluene was added to the resultant and heated to dissolve the mixture. The mixture was stored in a cold freezer for 12 hours and filtered to obtain diphenylsilanediol (DPSD) as white crystals [mp 144 ° C, yield of 86%, ¹ 1 H-NMR (300 MHz, CDCl ₃ )? 7.78, 7.78, 7.76, 7.75, 7.51, 7.49, 7.49, 7.47, 7.45, 7.43, 2.86, 2.23, 2.22, 2.22, 2.22, 0.27, 0.26].

Step 2: Synthesis of epoxy-oligosiloxane (E0)

Scheme 1-2

11.82 g (0.05 mol) of (3-glycidoxypropyl) trimethoxysilane (GPTMS) and 0.04 g (0.2 mmol) of barium hydroxide were placed in a 500 ml flask and stirred while being maintained at 80 ° C in an oil bath. After confirming that the temperature was kept constant, 10.8 g (0.05 mol) of diphenylsilanediol (DPSD) prepared in Step 1 was slowly added thereto under an argon gas atmosphere for 2 hours and stirred. At the beginning of the addition of diphenylsilanediol (DPSD), the opaque solution gradually became transparent as time elapsed. After the completion of the addition, the reaction was further continued for 2 hours and then the decompression was performed to remove all of the methanol generated as a by-product to obtain a transparent and transparent product, To obtain a siloxane (E0). 7.60, 7.63, 7.62, 7.60, 7.59 ( ¹ H-NMR) (300 MHz, CDCl ₃ ) 隆 7.68, 7.67, 7.65, 7.63 , 7.57, 7.54, 7.52, 7.47, 7.45, 7.44, 7.43, 7.42, 7.41, 7.39, 7.36, 7.34, 7.32, 7.29, 7.26, 7.23, 7.19, 7.17, 7.14, 7.13, 7.10, 3.64, 3.62, 3.57, 3.54 , 3.52, 3.51, 3.50, 3.48, 3.48, 3.47, 3.44, 3.41, 3.40, 3.39, 3.38, 3.37, 3.36, 3.34, 3.31, 3.30, 3.29, 3.28, 3.27, 3.26, 3.25, 3.22, 2.54, 2.53, 1.62 , 1.25, 0.65, 0.61].

Step 3: Synthesis of epoxy-based polysiloxane resin using phthalic anhydride curing agent

As a curing agent, 1.93 g (13 mmol) of phthalic anhydride and 20 ml of THF were placed in a 250 ml flask and stirred under an argon gas atmosphere. After completely dissolved, 5 g (13 mmol) of the epoxy-oligosiloxane (E0) resin obtained in the above step 2 and 18 mg (0.013 mmol) of N, N- dimethylbenzylamine were added and stirred for 3 hours. Thereafter, the product is depressurized to blow off all of the solvent to obtain a white viscous product of the following Reaction Schemes 1-3. The obtained product was placed in a mold, and then placed in a desiccator substituted with Ar gas and cured in an oven.

The following Schemes 1-4 illustrate the curing process during the production of the epoxy-based polysiloxane resin, which is a product, and the amine catalyst decomposes anhydrous rings to form internal salts as a curing initiator. Amine catalyst, the carboxylate ion reacts with the epoxy group of the epoxy-oligosiloxane (E0) to form an alkoxide ester, and the resulting alkoxide ester reacts further with an anhydride to form an ester of a carboxylate anion function, To carry out the oligosiloxane curing reaction by a continuous reaction.

Scheme 1-3

Scheme 1-4

Example 2 Synthesis of epoxy-based polysiloxane resin 2

As the curing agent, 3.55 g of 4,4 '- (4,4'-isopropylidenediphenoxy) bis (4,4'- (4,4'-Isopropylidenediphenoxy) bis (phthalic anhydride) (6.5 mmol) of triethylamine was used as the starting material, to obtain a viscous white product.

≪ Comparative Example 1 &

A transparent product was obtained in the same manner as in Example 1 except that 1.31 g (13 mmol) of acetic anhydride was used as a curing agent.

Example 3 Synthesis of Epoxy-Based Polysiloxane Resin Containing SiO ₂ Nanoparticles

는 SiO₂ 나노입자이다.20 ml of ethylene glycol dimethyl ether and SiO ₂ were added to a 30 ml glass bottle as a dispersing agent and ultrasonically dispersed for 1 hour. At this time, SiO ₂ Was calculated by adding 1 mol% of the total synthesis. Then, the flask was transferred into a 250 ml flask, and 1.93 g (13 mmol) of phthalic anhydride was added thereto and stirred in an argon gas atmosphere. 5 g (13 mmol) of the epoxy-oligosiloxane (E0) resin obtained in the step 2 of Example 1 and 18 mg (0.013 mmol) of N, N- dimethylbenzylamine were added thereto and stirred for 3 hours. Thereafter, the product is depressurized to blow off all of the solvent to obtain a white viscous product of the following reaction formula (2). The resulting product was placed in a mold and placed in a desiccator substituted with argon gas and cured in an oven maintained at 120 ° C for 60 minutes. In the following Reaction Scheme 2

Are SiO ₂ nanoparticles.

Scheme 2

Experimental Example 1 Measurement of Physical Properties of Crosslinking Agent

The curing temperature and curing time according to the curing agent prepared in Step 3 of Examples 1 to 3 and Comparative Example 1 are shown in Table 1 below.

<Experimental Example 2> Evaluation of physical properties of resin

The hardness and refractive index of the epoxy-based polysiloxane resin prepared in Examples 1 to 3 and Comparative Example 1 were measured using a durometer (GS-702N) and a refractometer (NAR-1T SOLID).

The degree of hardening was measured by measuring the hardness with time. The hardening was carried out in a desiccator substituted with argon gas and an oven maintained at 120 ° C. was used. At this time, the measurement of each sample was performed at intervals of 5 minutes.

The refractive index was measured using a refractometer (NAR-1 TSOLID) manufactured by making each resin to have a size of 10 x 40 x 1 mm. At this time, in order to eliminate the error due to the gap between the substrate and the sample of the refractometer, monobromonaphthalene Were used.

The transmittance of the epoxy-based polysiloxane resin prepared in Examples 1 to 3 and Comparative Example 1 was 10 × 40 × 1 mm and UV-vis spectrometer (UV-2401 PC, Shimazu) was used Respectively.

FIG. 1 shows the hardness of the epoxy-based polysiloxane resin according to Example 1 of the present invention as a result of time-hardness measurement. The hardness was no longer increased after 60 minutes, and the maximum hardness was 78.

In addition, the refractive index of the LED encapsulant is an important factor for achieving high luminous efficiency in white and high output LEDs through improved light emission efficiency. Thus, the refractive index of the epoxy-based polysiloxane resin of the present invention was measured to be 1.58 or more, regardless of the components thereof, because many phenyl groups existed.

FIG. 2 is a photograph of the transmittance evaluation photograph and the light transmittance spectrum of the epoxy-based polysiloxane resin prepared in Example 1, wherein the transmittance of the epoxy-based polysiloxane resin of the present invention was confirmed to be about 94% in the region of 460 nm, As a result of photographing, the transparency was visually confirmed.

FIG. 3 shows the results of measuring the hardness of the epoxy-based polysiloxane resin impregnated with the nanoparticles according to Example 1 of the present invention over time. The hardness was no longer increased after 60 minutes, the maximum hardness was 70, and the refractive index was about 1.57 .

4 is a transmittance evaluation images and the light transmittance spectrum results for the polysiloxane resins of the nanoparticles incorporated epoxy-based, SiO ₂ The epoxy-based polysiloxane resin in which the nanoparticles were embedded had transparency visually, and showed a transmittance of 90% in the 460 nm region as a result of spectral analysis.

FIG. 5 is a graph comparing the infrared spectrum of an epoxy-based polysiloxane resin prepared in Example 2 of the present invention with that of an epoxy oligosiloxane (EO) as a starting material and an epoxy-based polysiloxane resin as a synthetic material As a result, after the reaction, the bonding between the cyclodiether (-COC-) group and the epoxy group was compared. As a result, the bonding between the cyclodiether (-COC-) group and the epoxy group disappeared before and after the reaction, I could confirm.

FIG. 6 shows the results of the refractive index change according to the wavelength of the epoxy-based polysiloxane resin prepared in Example 2 of the present invention, showing a refractive index of 1.52 or more.

7 is a graph showing the results of thermogravimetric analysis (TGA) of the epoxy-based polysiloxane resin prepared in Example 2 of the present invention by measuring the weight change taking place in the material during heating and measuring the mass change with temperature, The thermogravimetric analysis (TGA) of epoxy oligosiloxane (EO) and epoxy-based polysiloxane resin, which is a synthetic material, confirmed the thermal stability at a temperature of 200 ° C or higher.

From the above results, it can be seen that when a non-aromatic group anhydride curing agent of Comparative Example 1, which is a conventional curing agent, was used, it was not cured for more than 12 hours (720 minutes). Therefore, in the case of using an anhydride curing agent of the aromatic groups of Examples 1 and 2 , It is possible to shorten more than 12 hours, and it is confirmed that the higher transmittance and the refractive index are maintained.

Further, compared to Example 1, SiO ₂ In Example 3 in which nanoparticles were incorporated, the refractive index, hardness, and transmittance were somewhat reduced.

These results show that the refractive index of SiO ₂ is 1.46, which is close to the refractive index of the nanoparticles when the nanoparticles are incorporated. Thus, the addition of TiO ₂ or pure Si nanoparticles with a high refractive index suggests the possibility of increasing the refractive index. Further, SiO ₂ The refractive index of the epoxy-based polysiloxane resin was still high even though the refractive index of the nanoparticles was 1.5 or less because the phenyl group was included in a large amount.

From the above results, it has been suggested that the refractive index of the resin can be controlled by incorporating the nanoparticles with controlled refractive index into the epoxy-based polysiloxane resin, and the resin having a lower hardness can be developed with more flexibility.

<Experimental Example 3> Evaluation of heat resistance of resin

The heat resistance of the epoxy-based polysiloxane resin prepared in Example 1 and the epoxy-based polysiloxane resin impregnated with SiO ₂ nanoparticles prepared in Example 3 was observed immediately after the initial curing, and the heat resistance was measured for 24 hours and 48 hours (UV-vis spectrometer, UV-2401 PC, Shimazu) after thermal aging at 120 ° C for 30 minutes.

8 shows that the epoxy-based polysiloxane resin of the present invention was evaluated for heat resistance with or without nanoparticle impregnation, wherein (a) the spectrum was the epoxy-based polysiloxane resin of Example 1, and (b) ₂ Based polysiloxane resin with nanoparticles incorporated therein. In each spectrum, the initial transmittance is expressed in red, the transmittance after 24 hours is represented by blue, and the transmittance after 48 hours is represented by green.

8 and Table 3, the epoxy-based polysiloxane resin prepared in Examples 1 and 3 exhibited a maximum variation of 15% or less with respect to the initial transmittance for thermal resistance at 120 ° C for 24 hours and 48 hours , And stable heat resistance was confirmed. Thus, the LED encapsulant using the resin of the present invention supports the resistance to yellowing.

As described above, the present invention provides a high-speed curing epoxy-based polysiloxane resin which maintains high transparency at high temperature and high transparency.

Accordingly, the LED encapsulant made of the ultra-high-speed curing epoxy-based polysiloxane resin of the present invention can maintain the refractive index and transparency at a high temperature by complementing the disadvantages of the epoxy resin and the silicone resin used in the conventional LED encapsulant, Can be minimized.

In addition, the ultra-high-speed curing epoxy-based polysiloxane resin of the present invention can further control the refractive index of the final resin according to the refractive index of the nanoparticles while maintaining the refractive index and transparency of the initial resin by further incorporating nanoparticles having different refractive indexes.

Further, in the present invention, SiO _{2 having a} refractive index of 1.46 The epoxy-based polysiloxane resin containing nanoparticles provided a flexible resin by lowering the hardness while maintaining the refractive index and transparency.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

The epoxy oligosiloxane and the aromatic group anhydride curing agent are thermosetting,
(1) a refractive index of 1.50 or more,
(2) a transmittance of 90% or more and
(3) Curing time is less than 60 minutes
An encapsulant for LED comprising an ultra-fast cure epoxy based polysiloxane resin. The encapsulating material for LED according to claim 1, wherein the anhydrous curing agent of the aromatic group has transparency under a curing condition of 120 to 180 캜 and realizes ultra-fast curing within 60 minutes. The LED according to claim 1, wherein the aromatic group anhydride curing agent is phthalic anhydride or 4,4 '- (4,4'-isopropylidenediphenoxy) bis (phthalic anhydride) Sealing material. delete The encapsulating material for LED according to claim 1, wherein the ultra-high-speed curing epoxy-based polysiloxane resin has heat resistance of not more than 15% in transmittance change for at least 48 hours at a temperature of 120 캜. The epoxy resin composition according to claim 1, wherein the ultra-high-speed curing epoxy-based polysiloxane resin is SiO ₂ Nanoparticles, TiO ₂ nanoparticles, or Si nanoparticles are incorporated. The method according to claim 1, wherein SiO ₂ nanoparticles having a refractive index of 1.50 or less are embedded in the ultra-high-speed curable epoxy-
(1) high refractive index with a refractive index of 1.50 or higher and
(2) A resin encapsulant for LED, which has a high transparency of 90% or more. An epoxy-oligomer silane (2) was synthesized by sol-gel reaction between an organoalkoxysilane (3) containing an epoxy group and an organosilane diol (4)
Thermosetting the epoxy-oligomeric silane (2) with an aromatic group anhydride curing agent at 120 to 180 캜 to obtain an epoxy-based polysiloxane resin (1).
Scheme 1

In the above, R ₁ to R ₃ are each a linear or branched C ₁ to C ₇ alkyl group. The epoxy-based resin composition according to claim 8, wherein the aromatic group anhydride curing agent is phthalic anhydride or 4,4 '- (4,4'-isopropylidenepiperoxy) bis (phthalic anhydride) Of the polysiloxane resin. The method of claim 8, wherein the thermal curing reaction is SiO ₂ Nanoparticles, TiO ₂ Nanoparticles or Si nanoparticles are dispersed in a solution to allow the nanoparticles to be incorporated.

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