KR20150047298A - Novel synthesis method of silane compound for packaging optical devices - Google Patents

Abstract

The present invention relates to a novel synthesis method of a silane compound, and more specifically, to a method for manufacturing a silane compound with the amount of impurities minimized by using an Ullmann-type reaction instead of a conventional Girgnard reaction, and a silane compound synthesized thereby. The method for manufacturing a silane compound of the present invention uses the Ullmann-type reaction instead of the conventional Girgnard reaction, thus can minimize the amount of impurities. In addition, physical and optical properties such as a water vapor transmission rate (WVTR), a degree of stickiness after hardening, and the color of a sample can be maximized, and useful for an optical element such as a flexible OLED element.

Description

TECHNICAL FIELD [0001] The present invention relates to a novel method for synthesizing a silane compound,

The present invention relates to a novel method for synthesizing a silane compound, and more particularly, to a method for preparing a silane compound in which the amount of impurities is minimized by using a Ullmann-type reaction instead of the conventional Grignard reaction And to silane compounds synthesized accordingly.

Organic materials included in optical devices such as OLEDs and LCDs are very vulnerable to oxygen or water vapor in the atmosphere, so that when exposed to oxygen or water vapor, a reduction in output or premature performance may occur. Thus, a method for protecting the devices by using metal and glass to prolong the lifetime of the device has been developed, but the metal generally has a disadvantage in that the transparency is insufficient and the glass has insufficient flexibility.

Accordingly, a transparent barrier film or encapsulant composition having flexibility, which is used for encapsulating other optical elements including a flexible and flexible OLED capable of being thin, light and bendable, has been developed. In particular, a silicone polymer Compounds have been constantly preferred and developed as encapsulants for optical elements.

Thus, conventionally, a silane compound for an optical element encapsulant was synthesized using a Grignard reaction. For example, a silane compound can be synthesized by the method shown in Reaction Scheme 1 below. However, when such a method is used, a monosubstituted or trisubstituted silane compound is produced as an impurity during synthesis, Trans. Mater. Soc. Jpn , 2011 , 36 , 257)

[Reaction Scheme 1]

In order to solve the above problems, it is an object of the present invention to provide a novel synthesis method capable of minimizing the amount of impurities in the synthesis of a silane compound in place of the conventional Grignard reaction, and a silane compound thus synthesized.

In order to achieve the above object,

1) reacting a halodialkylsilane compound of the formula 1 and a dihalobenzene compound of the formula 2 to prepare a halobenzene dialkylsilane compound of the formula 3;

2) reacting a halodialkylsilane compound represented by the following formula 1 with a halophenol compound represented by the following formula 4 to prepare a dialkylsilane phenol compound represented by the following formula 5; And

3) preparing a biphenyl ether silane compound represented by the following formula (6) by the Ullmann reaction of the compounds represented by the above formulas (3) and (5)

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

In this formula,

Each R is independently an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, or an aryl having 6 to 30 carbon atoms.

The present invention also provides a silane compound of the following formula (6-1) prepared according to the above method:

[Formula 6-1]

In this formula,

R is as defined above,

n is an integer from 2 to 50,000.

The present invention also provides a sealing film produced using the silane compound.

The silane compound production method of the present invention minimizes the amount of undesired monosubstituted or trisubstituted impurities in addition to the aimed disubstituted silane compound by using the conventional Grignard reaction instead of the conventional Grignard reaction And can maximize the physical and optical properties such as moisture vapor permeability (WVTR), tackiness after curing and color of a sample, and thus can be usefully used in optical devices including flexible OLED devices .

The present invention is characterized in that a silanol compound is used as a silane compound in the synthesis of a bisphenyl ether type silane compound.

Hereinafter, the present invention will be described in detail.

As a method of synthesizing a silane compound for optical element encapsulation, a method using a Grignard reaction has been conventionally used. For example, the reaction of the following reaction formula 1 can be mentioned.

[Reaction Scheme 1]

According to Reaction Scheme 1, firstly, as a starting material, bisphenyl ether dibromo compound of formula (7), magnesium and iodine as a starting material are used as a catalyst, and after stirring in a tetrahydrofuran solvent, chlorodimethylsilane of formula And refluxed for 24 hours to synthesize the desired compound of formula (VI).

However, when the silane compound is synthesized by the above-mentioned method, it is impossible to prevent the formation of mono- or tri-substituted silane compounds (impurities A and B) produced as main impurities in addition to the desired disubstituted silane compounds, Moisture permeability (WVTR), tackiness and transparency that are evaluated as properties.

On the other hand, in the present invention,

1) reacting a halodialkylsilane compound of the formula 1 and a dihalobenzene compound of the formula 2 to prepare a halobenzene dialkylsilane compound of the formula 3;

2) reacting a halodialkylsilane compound represented by the following formula 1 with a halophenol compound represented by the following formula 4 to prepare a dialkylsilane phenol compound represented by the following formula 5; And

3) preparing a biphenyl ether silane compound represented by the following formula (6) by the Ullmann reaction of the compounds represented by the above formulas (3) and (5) to prepare a silane compound for an optical encapsulant:

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

In this formula,

Each R is independently an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, or an aryl having 6 to 30 carbon atoms.

Specifically, the preparation method of the present invention can be carried out according to the following Reaction Scheme 2:

[Reaction Scheme 2]

Wherein R is as defined above.

As shown in Reaction Scheme 2, according to the method of the present invention, when synthesizing the desired product, Compound 6, 1) the starting material is less expensive than the compound 7 of Scheme 1 according to the conventional method, and 2) And 5, and then synthesizing the final product through the Ullmann reaction, there is an advantage that generation of the monosubstituted or tri-substituted silane compound, which is an impurity, can be minimized.

The present invention also provides a silane compound for encapsulating an optical element produced according to the above method. The silane compound is a material used as a thermosetting resin composition for encapsulating an optical element, and is used for increasing the lifetime of an optical element, and may preferably be a silane compound represented by the following formula (6-1)

[Formula 6-1]

In this formula,

R is as defined above,

n is an integer from 2 to 50,000.

The silane compound according to the present invention can be used as an encapsulating material in an optical element including a flexible OLED element by solving the disadvantages of metal and glass which are transparency and flexibility and can be crosslinked, It is possible to provide a composition for encapsulating an optical element which is excellent in mechanical properties and improved in adhesion to a substrate and barrier properties to moisture or oxygen.

When the silane compound of the present invention is used in the composition for encapsulating an optical element, it may be contained in an amount of about 0.01 to 50% by weight based on the weight of the total composition. Examples of the silsesquioxane copolymer, polysiloxane , A siloxane resin, a crosslinked resin, a silane coupling agent, a catalyst, and a reaction retarder.

Examples of the siloxane resin usable in the present invention include polymethylvinylsiloxane, poly (methylphenyl) hydrosiloxane, poly (methylphenyl) siloxane, poly (phenylvinyl) -co- (methylvinyl) silsesquioxane, PDV- Examples of the crosslinking resin include silsesquioxane copolymer, phenylhydrosilsesquioxane, and dimethylsilylphenyl ether. Examples of the silane coupling agent include methacrylate-based cyclosiloxane and the like, Examples of the catalyst include a platinum catalyst, and the reaction retarder includes ethynyltrimethylsilane, ethynyltriethylsilane, and the like, but not limited thereto, and may include at least one of these compounds.

The present invention also provides an optical element encapsulating film produced using the silane compound or a composition for encapsulating an optical element comprising the silane compound.

Since the optical element encapsulating film of the present invention is transparent and has excellent light transmittance and refractive index as well as no stickiness after curing and has an improved moisture permeability, it is effective in prolonging the life of an optical element when used as a sealing film for various optical elements, It can be used as a sealing film of flexible OLED.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Comparative Examples 1 to 3 : Synthesis of bisphenyl ether disilane compound (Formula 6)

[Reaction Scheme 1]

1) Synthesis of the compound of formula (8)

4-Bromophenyl ether (50.0 g, 152 mmol) of the formula (7) was added to the flask, and a dry THF solvent (375 mL, 7.5 mL / g) was added thereto to dissolve. Magnesium (8.87 g, 365 mmol ) And iodine (3.85 g, 15.2 mmol) were dissolved in dry THF (25.0 mL) and slowly added dropwise. After completion of the dropwise addition, the reaction product was refluxed to synthesize a Grignard compound of formula (8).

2) Synthesis of compound of formula (6)

The Grignard compound of Formula 8 was placed in a flask and the chloro-dimethylsilane compound of Formula 1 (51.0 mL, 456 mmol) was added thereto while maintaining the temperature at 0 ° C, followed by stirring at room temperature for 24 hours. After completion of the reaction, the reaction mixture was quenched with a saturated aqueous solution of NH ₄ Cl, extracted with an EtOAc solvent, washed with brine, dried over anhydrous Na ₂ SO ₄ , filtered and concentrated. HPLC measurements were carried out with the reaction mixture to determine the proportion of impurities A and B in addition to the compound of formula 6, and the results are shown in Table 1 below.

The mixture was further separated and purified by ¹ H-NMR using a flash column chromatography (Pet.ether: DCM = 5: 1) method under SiO ₂ .

[Compound (6) (target compound)]

_{^{1 H-NMR (CDCl 3,}} Varian 400 MHz): δ 0.34 (12H, d, J = 4.0 Hz), 4.41-4.45 (1H, sept, J = 4.0 Hz), 7.01 (2H, d, J = 8.4 Hz ), 7.50 (2H, d, J = 8.4 Hz).

[Impurity A (monosubstituted silane compound)]

_{^{1 H-NMR (CDCl 3,}} Varian 400 MHz): δ 0.34 (6H, d, J = 4.0 Hz), 4.41-4.45 (1H, sept, J = 4.0 Hz), 6.99 (2H, d, J = 8.4 Hz ), 7.03 (2H, d, J = 7.6Hz), 7.12 (1H, t, J = 7.6Hz), 7.31-7.36 (2H, m), 7.44 (2H, d, J = 8.4Hz).

[Impurity B (trisubstituted silane compound)]

_{^{1 H-NMR (CDCl 3,}} Varian 400 MHz): δ 0.34 (18H, d, J = 4.0 Hz), 4.41-4.46 (3H, sept, J = 4.0 Hz), 6.81 (1H, d, J = 8.0 Hz ), 6.99 (2H, d, J = 8.4 Hz), 7.49 (1H, dd, J = 8.0, 1.6 Hz), 7.50 ).

To the reaction mixture (compound of formula (VI), 10 parts by weight) were added three kinds of resins, vinyl terminated poly (methylphenyl) siloxane, vinyl terminated silsesquioxane copolymer and poly (methylphenyl) hydrosiloxane (WVTR) was prepared by polymerizing 5 parts by weight of a catalyst (80 parts by weight), Pt catalyst (5 parts by weight) and inhibitor (5 parts by weight) And the degree of stickiness after curing (Tacky) were measured according to a known method. The results are shown in Table 1 below.

HPLC
data RT (min) RRT Percentage of compound Comparative Example 1 Comparative Example 2 Comparative Example 3 Impurity A 4.36 0.83 7.59 5.66 7.89 Unknown 4.75 0.91 - - - Compound 6 5.21 1.00 83.49 85.17 86.60 Unknown 5.62 1.07 0.47 0.42 0.44 Impurity B 6.13 1.17 5.63 6.82 5.04 WVTR (g / m ² ) 20 18 16 Degree of stickiness after curing has exist has exist has exist color Light yellow Light yellow Light yellow

As shown in Table 1, it was confirmed that impurities A and B were present together with Compound 6, which is a product after completion of the reaction, and it was pale yellow which was not colorless. The presence of such impurities affects the moisture permeability and the degree of stickiness after curing.

Example 1 : Synthesis of bisphenyl ether disilane compound (Formula 6)

[Reaction Scheme 2]

1) Synthesis of Compound (3)

BuLi (28.0 mL, 70 mmol, 2.5 mmol) was added at -78 째 C to a solution of dibromobenzene of Formula 2 (15.0 g, 63.5 mmol) in a flask and dissolved with a dry THF solvent (150 mL, 10 mL / M solution (in hexane) was slowly added thereto, followed by stirring at -78 ° C for 3 hours. Then, chlorodimethylsilane (8.50 mL, 92.5 mmol) of the formula (1) was added and reacted at room temperature with stirring. After the reaction was completed, the reaction mixture was quenched with a saturated aqueous NH ₄ Cl solution, extracted with EtOAc solvent, washed with brine, dried over anhydrous Na ₂ SO ₄ , filtered and concentrated. The reaction mixture was purified by vacuum distillation (70-75 캜, 10 mmbar) to give the compound of formula (3) as a colorless oily phase (10.8 g, 80% yield).

_{^{1 H-NMR (CDCl 3,}} Varian 400 MHz): δ 0.34 (6H, d, J = 4.0 Hz), 4.41-4.45 (1H, sept, J = 4.0 Hz), 7.41 (2H, d, J = 8.0 Hz ), 7.51 (2H, d, J = 8.0 Hz).

2) Synthesis of Compound (5)

4-Bromophenol (14.0 g, 80.0 mmol) of the formula 4 was dissolved in a dry THF solvent (240 mL, 17 mL / g) and added at -78 ° C with n-BuLi (72.0 mL, 180 mmol , 2.5 M solution (in hexane)) was slowly added thereto, followed by stirring at -78 ° C for 2 hours. Thereafter, chlorodimethylsilane (11.0 mL, 120 mmol) of the formula (1) was added and reacted at room temperature with stirring. After completion of the reaction, the reaction mixture was neutralized with a saturated aqueous solution of NH ₄ Cl, extracted with EtOAc solvent, washed with brine, dried over anhydrous Na ₂ SO ₄ , filtered and concentrated. The reaction mixture was purified by flash column chromatography (pentane: EtOAc = 19: 1) to give the compound of formula 5 as a colorless oily phase (10.9 g, 82% yield).

_{^{1 H-NMR (CDCl 3,}} Varian 400 MHz): δ 0.34 (6H, d, J = 4.0 Hz), 4.41-4.45 (1H, sept, J = 4.0 Hz), 5.03 (1H, brs), 6.88 (2H , d, J = 8.4Hz), 7.45 (2H, d, J = 8.4Hz).

3) Synthesis of Compound (6)

4-Bromobenzene-dimethylsilane (10.0 g, 46.5 mmol), copper iodide (44.3 mg, 0.233 mmol) and benzotriazole (55.4 mg, 0.465 mmol) were added to a flask and dimethylsulfoxide 50 mL, 5 mL / g), and the mixture was stirred at room temperature for 30 minutes. Then, 4-dimethylsilanephenol (8.50 g, 55.8 mmol) and sodium tert-butoxide (6.26 g, 65.1 mmol) And reacted at 95 to 100 DEG C for 18 hours with stirring. After completion of the reaction, the powder is extracted with water and EtOAc solvent, washed with saline, dried over anhydrous Na ₂ SO _4, filtered and concentrated to a. The reaction mixture was subjected to HPLC measurement to determine the proportion of the impurities A and B in addition to the compound of the formula 6. The results are shown in Table 2 below.

In addition, the reaction mixture was purified by flash column chromatography under the SiO ₂ were isolated, respectively, using the method and confirmed by ^{1 H-NMR (Pet.ether: 1} : DCM = 5).

_{^{1 H-NMR (CDCl 3,}} Varian 400 MHz): δ 0.34 (12H, d, J = 4.0 Hz), 4.41-4.45 (1H, sept, J = 4.0 Hz), 7.01 (2H, d, J = 8.4 Hz ), 7.50 (2H, d, J = 8.4 Hz).

In addition, the specimen was prepared in the same manner as in Comparative Example 1 with the reaction mixture, and the moisture permeability and the degree of hibernation after curing were measured according to a known method. The results are shown in Table 2 below.

HPLC
data RT (min) RRT The ratio of the compound of Example 1 Impurity A 4.36 0.83 0.44 Unknown 4.75 0.91 0.56 Compound 6 5.21 1.00 95.26 Unknown 5.62 1.07 2.74 Impurity B 6.13 1.17 0.50 Water vapor permeability (g / m ² ) 14 Degree of stickiness after curing none color Colorless

Compared to the compounds of Comparative Examples 1 to 3, which were synthesized according to the conventional synthesis method, at least 95% of the purity of the biphenyl ether disilane compound prepared according to the novel synthesis method of the present invention, as shown in Table 2 above It can be confirmed that the content of impurities is small. In addition, the water vapor transmission rate was lower than that of the compounds of Comparative Examples 1 to 3, and there was no tackiness after curing, and it was confirmed that the compound had excellent optical properties and physical properties because it was a colorless compound.

Claims (4)

1) reacting a halodialkylsilane compound of the formula 1 and a dihalobenzene compound of the formula 2 to prepare a halobenzene dialkylsilane compound of the formula 3;
2) reacting a halodialkylsilane compound represented by the following formula 1 with a halophenol compound represented by the following formula 4 to prepare a dialkylsilane phenol compound represented by the following formula 5; And
3) preparing a biphenyl ether silane compound of formula (6) by the Ullmann reaction of the compound of formula (3) and formula (5)
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

In this formula,
Each R is independently an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, or an aryl having 6 to 30 carbon atoms. A process for producing a silane compound, wherein the process is carried out according to the following Reaction Scheme 2:
[Reaction Scheme 2]

In this formula,
Each R is independently an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, or an aryl having 6 to 30 carbon atoms. A silane compound represented by the following formula (6-1), prepared according to the process of claim 1:
[Formula 6-1]

In this formula,
Each R is independently an alkyl having 1 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, or an aryl having 6 to 30 carbon atoms.
n is an integer from 2 to 50,000. An optical element encapsulating film produced by using the silane compound for encapsulating an optical element according to claim 3.