KR101763464B1 - Polyorganosiloxane and coating agent composition comprising the same and coating layer comprising the coating agent - Google Patents

Abstract

Polyorganosiloxanes and coating compositions comprising them are provided. Specifically, the polyorganosiloxane is prepared using silane having bifunctional and trifunctional properties, and may include a structure represented by the following formula (1). Accordingly, the polyorganosiloxane of the present invention can have an appropriate molecular weight and an excellent refractive index by controlling the degree of crosslinking and the phenyl group according to degree of substitution. In addition, the coating layer formed using the coating composition containing the polyorganosiloxane may have optimized hardness and heat resistance characteristics.
[Chemical Formula 1]

Description

FIELD OF THE INVENTION [0001] The present invention relates to a polyorganosiloxane, a coating composition containing the same, and a coating layer containing the polyorganosiloxane,

The present invention relates to siloxanes, and more particularly to polyorganosiloxanes and coating compositions comprising them.

Siloxane, which is a main component of silicone resin, was produced in various kinds of products in 1940 's with mass production in the US due to its excellent properties. Recently, the siloxane has been applied to a wider field depending on the development of the electronic industry. Generally, the structure of the siloxane refers to a bond (Si-O-Si) between a silicon (Si) atom and an oxygen (O) atom and the structure is determined by the kind of a substituent bonded to the silicon atom and the number of siloxane bonds .

Siloxane compounds can generally be represented in the form of structures made up of monofunctional, difunctional, trifunctional, and quadrifunctional monomers. have. At present, polydimethylcyclosiloxane (PDMS), which is used as silicone oil or silicone rubber, is composed of bifunctional subunits and has a linear structure, which is excellent in flexibility and hydrophobicity, but has a relatively low hardness have. On the other hand, the silicone resin has a crosslinking structure as it contains a large number of trifunctional subunits and tetra-functional subunits, and thus has a higher hardness than the compound prepared from the bifunctional mixture.

Here, it is known that the refractive index is increased when the alkyl group of the main chain is substituted with a phenyl group, but the method of quantitatively introducing it and its characteristics are not well known.

It is an object of the present invention to provide a polyorganosiloxane having a proper refractive index and hardness by controlling the crosslinking density and the phenyl content, a coating composition comprising the same, and a coating layer.

In order to solve the above problems, an aspect of the present invention provides a polyorganosiloxane comprising a structure represented by the following formula (1), which is prepared using silane having bifunctionality and trifunctionality .

[Chemical Formula 1]

Wherein R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms, R ₄ is a phenyl group, X ₁ and X ₂ are each independently OH, halogen or an alkoxy group having 1 to 3 carbon atoms M + p is an integer of 1 to 500, and n is an integer of 0 to 500.

The degree of substitution of the polyorganosiloxane may be 1.0 to 1.3.

The molar ratio of the phenyl group (R ₄ ) to the alkyl group (R ₁ , R ₂ , R ₃ ) may be 0.2 to 0.7.

Specifically, the polyorganosiloxane of the present invention comprises 0 to 30 mol% of a bifunctional alkylsilane represented by the following formula (A), 26 to 80 mol% of a trifunctional alkylsilane represented by the following formula (B) And 20 to 50 mol% of a styrene phenyl silane.

(A)

[Chemical Formula B]

≪ RTI ID = 0.0 &

In the formula A-C, R _1, R ₂ and R ₃ are each independently an alkyl group having 1 to 6, R ₄ is a phenyl _{group, X a1, X a2, X} b1, X b2, X c1, X c2 , X ₁ and X ₂ are each independently OH, halogen or an alkoxy group having 1 to 3 carbon atoms.

The weight average molecular weight of the polyorganosiloxane may be 1500 to 4000.

Another aspect of the present invention can provide a coating composition comprising the above-described polyorganosiloxane and an organic solvent.

The refractive index of the coating composition may be 1.430 to 1.439.

Another aspect of the present invention can provide a coating layer characterized by being formed by applying the coating composition on a substrate.

The pencil hardness of the coating layer may be from 1 H to 4H.

The polyorganosiloxane of the present invention can have an appropriate molecular weight and an excellent refractive index by controlling the degree of crosslinking and the phenyl group according to degree of substitution.

In addition, the coating layer formed using the coating composition containing the polyorganosiloxane may have optimized hardness and heat resistance characteristics.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a schematic view showing a coating layer formed on a substrate using a coating composition according to an embodiment of the present invention.
2 shows a process for producing the polyorganosiloxane of Example 1 of the present invention.
3 is a graph showing the results of measuring the weight average molecular weight (Mw) according to the substitution degree of the polyorganosiloxane prepared in Example 1 of the present invention and the molar ratio of the phenyl group and the methyl group.
4 is a graph showing the change in refractive index (RI) according to the substitution degree of the coating composition comprising the polyorganosiloxane prepared in Example 2 and the molar ratio of the phenyl group and the methyl group.
5 is a chart showing the results of pencil hardness measurement of the coating layer prepared in Example 3 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

In the drawings, the thicknesses of the layers and regions may be exaggerated or reduced for clarity. Like reference numerals throughout the specification denote like elements.

Method for producing polyorganosiloxane

The polyorganosiloxane of the present invention may be one prepared using silanes having bifunctional and trifunctional properties. Specifically, the bifunctional silane may be a bifunctional alkylsilane represented by the following formula (A), and the trifunctional silane may be a trifunctional alkylsilane represented by the following formula (B) and a trifunctional alkylsilane represented by the following formula Functional phenyl silane.

(A)

[Chemical Formula B]

≪ RTI ID = 0.0 &

In the above formulas A to C,

R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms,

R ₄ is a phenyl group,

X _a1 , X _a2 , X _b1 , X _b2 , X _c1 , X _c2 , X ₁ and X ₂ are each independently OH, halogen or an alkoxy group having 1 to 3 carbon atoms.

The alkyl group having 1 to 6 carbon atoms may be methyl, ethyl or propyl, isopropyl, butyl, pentyl or hexyl, May be substituted with a halogen group. The alkoxy group having 1 to 3 carbon atoms may be a methoxy group, an ethoxy group, or a propoxy group, and may be substituted with a halogen group. The halogen group may be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

Specifically, the bifunctional alkylsilane having the structure of Formula (A) used in the production of the polyorganosiloxane is, for example, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, Diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dibutyldimethoxysilane, dibutyldimethoxysilane, dibutyldimethoxysilane, But are not limited to, dipentyldimethoxysilane, dipentyldiethoxysilane, dihexyldimethoxysilane, dihexyldiethoxysilane, and the like.

The trifunctional alkylsilane having the structure of Formula (B) used in the production of the polyorganosiloxane may be, for example, methyltrimethoxysilane, methyltriethoxysilane, methyltriethoxysilane, But may be, for example, methyltripropoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, chloropropyltrimethoxysilane or chloropropyltriethoxysilane and the like, It does not.

In addition, the trifunctional phenylsilane having the structure of Formula C used in the production of the polyorganosiloxane may be, for example, phenyltrimethoxysilane (PTMS), but is not limited thereto.

Specifically, the polyorganosiloxane of the present invention comprises 0 to 30 mol% of the bifunctional alkylsilane having the structure of the formula (A), 26 to 80 mol% of the trifunctional alkylsilane having the structure of the formula (B) And 20 to 50 mol% of trifunctional phenylsilane having the structure of C in the formula (1). This is shown in Reaction Scheme 1 below.

[Reaction Scheme 1]

In the above Reaction Scheme 1,

R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms,

R ₄ is a phenyl group,

_{X a1, X a2, X b1} , X b2, X c1, X c2, X 1 and X ₂ are each independently an alkoxy group of OH, halogen or 1 to 3 carbon atoms,

M + p is an integer of 1 to 500,

And n is an integer of 0 to 500.

When the silanes are mixed at the above-mentioned mixing ratio (mol%), a condensation reaction may occur between the silanes to produce a polyorganosiloxane. That is, the polyorganosiloxane may be prepared by polycondensation or hydrolysis reaction of the bifunctional alkylsilane, the trifunctional alkylsilane and the trifunctional phenylsilane. The hydrolysis and polycondensation of the silanes can be carried out by reacting a bifunctional alkylsilane having the structure of Formula A, a trifunctional alkylsilane having the structure of Formula B, or an alkoxy of the trifunctional phenylsilane having the structure of Formula C The group may form a hydroxyl group by hydrolysis by water, and the formed hydroxyl group may form a siloxane bond while forming a condensation reaction with the hydroxyl group or the alkoxy group of the other silane. The hydrolysis and polycondensation reaction of the silanes may be affected by the reaction temperature, the amount of the catalyst, or the solvent, so that the production process can be carried out in an appropriate range and atmosphere. For example, in the reaction, the reaction temperature may be, but is not limited to, being performed within a temperature range of 60 ° C to 80 ° C for 12 hours to 36 hours.

Further, in the production of the polyorganosiloxane of the present invention, a catalyst and water may be further added for the hydrolysis and polycondensation reaction described above.

The catalyst is added for the hydrolysis and polycondensation reaction without any side reaction, and any of the materials used in the production of the known siloxane resin can be used. Specifically, the catalyst may be an acid catalyst such as acetic acid, nitric acid, hydrochloric acid, phosphoric acid, oxalic acid or benzoic acid, or a base catalyst such as potassium hydroxide, sodium hydroxide, ammonia or barium hydroxide. The amount of the catalyst is not particularly limited, but it may be 0.0001 to 10 parts by weight based on 100 parts by weight of the silane participating in the reaction.

The water may be added in the form of an aqueous solution or a vapor depending on the process conditions. By controlling the amount and method of adding water, the hydrolysis and polycondensation reaction can be prevented from proceeding too early to precipitate the product.

Polyorganosiloxane

One aspect of the present invention can provide a polyorganosiloxane. The polyorganosiloxane may be one prepared by a process for producing the above-described polyorganosiloxane. Specifically, the polyorganosiloxane comprises 0 to 30 mol% of a bifunctional alkylsilane represented by the following formula (A), 26 to 80 mol% of a trifunctional alkylsilane represented by the following formula (B), and a trifunctional And 20 to 50 mol% of phenyl silane.

(A)

[Chemical Formula B]

≪ RTI ID = 0.0 &

In the above formulas A to C,

R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms,

R ₄ is a phenyl group,

X _a1 , X _a2 , X _b1 , X _b2 , X _c1 , X _c2 , X ₁ and X ₂ are each independently OH, halogen or an alkoxy group having 1 to 3 carbon atoms.

That is, the polyorganosiloxane may be prepared using a silane having bifunctional and trifunctional properties, and may include a structure represented by the formula (1).

[Chemical Formula 1]

In Formula 1,

R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 3 carbon atoms,

R ₄ is a phenyl group,

X ₁ and X ₂ are OH, a halogen or an alkoxy group having 1 to 3 carbon atoms,

M + p is an integer of 1 to 500,

And n is an integer of 0 to 500.

In one embodiment of the present invention, the degree of substitution of the polyorganosiloxane may be 1.0 to 1.3. This may be so as to allow the coating composition containing the polyorganosiloxane to have appropriate refractive index and hardness properties by constituting the polyorganosiloxane to have a degree of substitution within the above range.

Generally, the degree of crosslinking of the siloxane resin is represented by the subunit ratio, T / Q. Is calculated as the ratio of M / Q to M / T or the degree of substitution (ds) which is the ratio of R / Si, which is the ratio of the organic group (R) per silicon atom (Si) .

... ... Equation (1)

Herein, OMe means methoxysilane, ds means the number of organic groups (R) bonded to the silicon atom (Si), n is 1 when the monomer is a trifunctional (T) monomer, , N may be 2. That is, as the degree of substitution (ds) is closer to 2, D means a siloxane having many subunits in which two alkyl groups are bonded to one silicon atom (Si), and the closer to 1, the more the trifunctional (T) Can mean high crosslinked siloxane.

In one embodiment of the present invention, the mole ratio of the phenyl group to the alkyl group may be 0.2 to 0.7. This may be so that the coating composition comprising the polyorganosiloxane can have appropriate refractive index and hardness characteristics by constituting the polyorganosiloxane so that it can contain a phenyl group within the above range.

Generally, the content of the phenyl group bonded to the silicon (Si) atom can be represented by the molar ratio of the phenyl group and the alkyl group, and can be expressed by the following formula (2).

... ... Equation (2)

In one embodiment of the present invention, the weight average molecular weight (Mw) of the polyorganosiloxane may be from 1,500 to 100,000. Preferably, the weight average molecular weight of the polyorganosiloxane may range from 1,500 to 4,000. The weight average molecular weight of the polyorganosiloxane may be increased as the degree of substitution of the polyorganosiloxane is lowered and the content of the phenyl group is lowered. If the weight average molecular weight of the polyorganosiloxane is less than 1,500, it may be difficult for the coating composition containing the polyorganosiloxane to have desired hardness and refractive index characteristics. If the weight average molecular weight of the polyorganosiloxane exceeds 4,000, The light transmittance of the film made of the coating composition containing the same may be lowered or the viscosity may be increased, so that the application of the coating composition may be limited.

A coating composition comprising a polyorganosiloxane

Another aspect of the present invention can provide a coating composition comprising the above-described polyorganosiloxane and an organic solvent. The organic solvent may be added for stability and viscosity control, and may be a substance which does not affect the properties of the polyorganosiloxane. Specifically, the organic solvent may be any organic solvent added to the known siloxane resin. The organic solvent may be, for example, an acetate solvent such as propylene glycol monomethyl ether acetate (PGMEA), an alcohol solvent such as isopropyl alcohol or butyl alcohol, An ether type solvent such as tetrahydrofuran (THF) or propylene glycol propyl ether; an amide type solvent such as dimethylformamide (DMF); a ketone type solvent such as acetone; And a solvent, but the present invention is not limited thereto.

In addition, the refractive index of the coating composition may be 1.430 to 1.439. Specifically, this can be explained in detail in the following examples and drawings.

Another aspect of the present invention can provide a coating layer characterized by being formed by applying the coating composition on a substrate.

1 is a schematic view showing a coating layer formed on a substrate using a coating composition according to an embodiment of the present invention.

Referring to FIG. 1, the coating composition may be applied on a substrate 10 to form a coating layer 20. After the application, the drying step and the baking step can be performed in order. The firing process may be a thermal curing process or a UV curing process, and the silane bonds that are not formed in the coating composition by the firing process may further hydrolyze and polycondensate to form a siloxane bond have.

The substrate 10 may be any substrate that can be coated and may be formed of a plastic substrate such as polyethylene terephthalate (PET), polyether naphthalate (PEN), polyimide (PI), or polycarbonate (PC) , A substrate of resin such as acrylic, urethane or silicone epoxy, a rubber substrate, a ceramic substrate, a metal substrate, various types of paper, and a composite material obtained by mixing these materials.

The method of applying the coating composition on the substrate 10 can be performed by any suitable method such as spin coating, roll coating, spray coating, dip coating, flow coating, Such as a doctor blade, ink-jet printing, screen printing, gravure printing, imprinting, chemical vapor deposition or physical vapor deposition, Method, and the like may be used, but the present invention is not limited thereto.

The pencil hardness of the coating layer may be from 1 H to 4H. The pencil hardness is one of the general hardness measurement methods and may be measured using a conventional pencil hardness meter. Specifically, this can be explained in detail in the following examples and drawings.

The coating layer formed using the coating composition exhibits optimized hardness characteristics and excellent coating properties and can be applied to various materials such as a surface of various semiconductor devices such as a display liquid crystal screen, a monitor, or a transparent substrate surface.

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.

[Example]

≪ Example 1: Preparation of polyorganosiloxane >

148 g of propylene glycol monomethyl ether acetate (PGMEA), 2 g of acetic acid and 79.39 g of distilled water were added to a 500 mL four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel. After stirring, 200 g of methyltrimethoxysilane (MTMS) was added dropwise over 60 minutes. After the dropwise addition, the mixture was refluxed at 98 ° C to 103 ° C for 2 hours, and the temperature of the oil bath was raised to 120 ° C to 125 ° C. Then, a dean-stark trap was added until the temperature of the reaction reached 100 ° C. And kept for 30 minutes while removing water and alcohol. Thereafter, the reaction product was cooled to obtain a transparent viscous resin. The obtained resin material was distilled at 150 DEG C for 30 minutes to remove unreacted materials and condensation products to prepare a siloxane resin (sample 1) composed of only three functional (T) subunits.

Using the method described above to the methyltrimethoxysilane and phenyltrimethoxysilane (phenyltrimethoxysilane, PTMS) methyl group, using, as shown in Table 1 (T ^me) and a phenyl group (T ^Ph) samples having a small unit with 2 to Sample 5 Were synthesized. In addition, siloxane resins (Sample 6 to Sample 10) composed of bifunctional / trifunctional (DT) subunits were prepared using dimethyldimethoxysilane (DMDMS). The reaction formula according to the above-described manufacturing process is shown in FIG.

sample Factor Output value (%) The monomer reactant (g) Degree of substitution Ph / Me D T T ^pH DMDMS MTMS PTMS PGMEA water ethanol Sample 1 1.0 0.00 100.0 200 148 79.37 2 Sample 2 1.0 0.25 80.0 20.0 150 54.59 164.25 74.41 2.05 Sample 3 1.0 0.50 66.7 33.3 110 79.94 159.5 65.45 1.9 Sample 4 1.0 0.75 57.1 42.9 95 103.9 171.95 66.03 1.99 Sample 5 1.0 1.00 50.0 50.0 80 116.45 172.8 63.5 1.96 Sample 6 1.3 0.00 30.0 70.0 52.95 140 152.6 71.43 1.93 Sample 7 1.3 0.25 30.0 44.0 26.0 48.14 80 68.81 171.2 64.94 1.97 Sample 8 1.3 0.50 30.0 26.7 43.3 44.62 45 106.23 178.2 60.2 1.96 Sample 9 1.3 0.75 30.0 14.3 55.7 42.58 23 130.41 184 57.45 1.6 Sample 10 1.3 1.00 30.0 5.0 65.0 39.71 7.5 141.93 180.75 53.58 1.89

≪ Example 2: Preparation of coating composition comprising polyorganosiloxane >

PGMEA was added to the polyorganosiloxane resin samples prepared in Example 1 to prepare a 35 wt% solution coating composition.

≪ Example 3: Preparation of coating layer using coating composition >

The coating composition prepared in Example 2 was divided into samples and coated on a glass plate having a width of 100 mm, a length of 100 mm and a thickness of 2 mm using a bar coater (Bar Coater # 5) at a temperature of 0 to 4.2 탆 at room temperature, For 30 minutes to partially evaporate the diluted solvent and then thermally cured in an electric oven at 150 ° C for 30 minutes to form a coating layer.

3 is a graph showing the results of measuring the weight average molecular weight (Mw) according to the substitution degree of the polyorganosiloxane prepared in Example 1 of the present invention and the molar ratio of the phenyl group and the methyl group. Molecular weight measurement was performed using Aglient's model No. 1260 GPC.

Referring to FIG. 3, it can be seen that the lower the degree of substitution of the polyorganosilonic acid, that is, the higher the degree of crosslinking, and the lower the phenyl content, the higher the molecular weight. This may be due to the high degree of crosslinking and the lower the phenyl content, the higher the siloxane bond. Also, in the case of Samples 1 to 5 (see Table 1) composed of the trifunctional alkylsilane and the trifunctional phenylsilane except for the bifunctional alkylsilane (see Table 1), it can be seen that the lower the phenyl group, the more the molecular weight increases sharply. This can be attributed, in part, to the gelation of the reactants during synthesis. The present invention can provide a polyorganosiloxane having desired physical properties by adding a bifunctional alkylsilane in an appropriate amount and reacting in order to minimize such phenomenon, and its application range can be expanded.

4 is a graph showing the change in refractive index according to the substitution degree of the coating composition containing the polyorganosiloxane prepared in Example 2 of the present invention and the molar ratio of the phenyl group and the methyl group. The refractive index of the coating composition of Example 2 was measured with an Abbe refractometer.

Referring to FIG. 4, the refractive index of the coating composition was 1.446 in the sample having the highest phenyl content, and the refractive index was increased as the phenyl content was increased. In addition, the refractive index changes according to the degree of substitution (d.s.) reveal that the refractive index is the highest at the degree of substitution of 1.3, in which the crosslinking density is low and the phenyl content is high. Generally, since the phenyl group has a macroscopic structure more than the methyl group (alkyl group), the refractive index tends to increase as the phenyl content increases. This tendency can be conspicuously exhibited in a low crosslinking density, that is, in a relatively low molecular weight siloxane resin. Thus, the polyorganosiloxane of the present invention can control the phenyl content so that the refractive index of the polyorganosiloxane can be about 1.43. Thus, the mole ratio of the phenyl group to the methyl group of the present invention can be optimized from 0.2 to 0.7.

As described above, the coating composition containing the polyorganosiloxane of the present invention can maintain the coating property by lowering the crosslinking density by using the DMDMS together, and at the same time, exhibit the effect of high refractive index. In addition, this may be an improvement in that the conventional polysiloxane incorporating only the phenyl group has a high refractive index, but has a limitation in the use of the polysiloxane as a coating agent since the physical property exists as a solid at room temperature.

5 is a chart showing the results of pencil hardness measurement of the coating layer prepared in Example 3 of the present invention.

Referring to FIG. 5, the pencil hardness of the polyorganosiloxane having only the methyl T subunit was 4H at the maximum, and the pencil hardness was increased as the degree of crosslinking was high and the phenyl content was low. This is because Si-OR or Si-OH remains when relatively high steric hindrance effect occurs when a polycondensation reaction by hydrolysis is performed using alkoxysilane having a high phenyl content as a raw material. can do.

3 to 5 and Table 2, the weight average molecular weight of the polyorganosiloxane of Sample 2 to Sample 5 and Sample 7 to Sample 8 is 1500 to 4000, and the coating composition comprising the same A refractive index of 1.43 (1.430 to 1.439), and a pencil hardness measurement value of a coating layer formed using the coating composition shows a hardness of 1 H or more.

As described above, in order to control the crosslinking density and the phenyl content in an appropriate amount, the present invention is characterized in that it comprises 0 to 30 mol% of a bifunctional alkylsilane, 26 to 80 mol% of the trifunctional alkylsilane, At a mixing ratio (molar%) of 20 to 50 mol% to prepare a polyorganosiloxane, a coating composition containing the polyorganosiloxane realizes an appropriate refractive index, and the coating layer formed of the coating composition has an effect of having an optimized hardness have.

sample Factor Output value (%) Molecular Weight
(Mw) Refractive index
(RI) Hardness
(hardness) Degree of substitution Ph / Me D T T ^pH Sample 1 1.0 0.00 100.0 9800 1.412 4H Sample 2 1.0 0.25 80.0 20.0 3200 1.428 3H Sample 3 1.0 0.50 66.7 33.3 1800 1.436 3H Sample 4 1.0 0.75 57.1 42.9 1700 1.438 2.5H Sample 5 1.0 1.00 50.0 50.0 1600 1.442 2H Sample 6 1.3 0.00 30.0 70.0 2400 1.413 3H Sample 7 1.3 0.25 30.0 44.0 26.0 1800 1.429 H Sample 8 1.3 0.50 30.0 26.7 43.3 1500 1.437 H Sample 9 1.3 0.75 30.0 14.3 55.7 1100 1.444 2B Sample 10 1.3 1.00 30.0 5.0 65.0 1000 1.446 2B

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

Claims (9)

A polyorganosiloxane having a structure represented by the following formula (1) and having a degree of substitution of from 1.0 to 1.3, which is prepared by using a silane having bifunctionality and trifunctionality:
[Chemical Formula 1]

In Formula 1,
R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms,
R ₄ is a phenyl group,
X ₁ and X ₂ are each independently OH, a halogen or an alkoxy group having 1 to 3 carbon atoms,
M + p is an integer of 1 to 500,
And n is an integer of 0 to 500. delete The method according to claim 1,
Wherein the molar ratio of the phenyl group (R ₄ ) to the alkyl group (R ₁ , R ₂ , R ₃ ) is 0.2 to 0.7. 0 to 30 mol% of a bifunctional alkylsilane represented by the following formula (A);
26 to 80 mol% of a trifunctional alkylsilane represented by the following formula (B); And
And 20 to 50 mol% of a trifunctional phenylsilane represented by the following formula (C), wherein the polyorganosiloxane having a degree of substitution of 1.0 to 1.3:
(A)

[Chemical Formula B]

≪ RTI ID = 0.0 &

In the above formulas A to C,
R ₁ , R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms,
R ₄ is a phenyl group,
X _a1 , X _a2 , X _b1 , X _b2 , X _c1 , X _c2 , X ₁ and X ₂ are each independently OH, halogen or an alkoxy group having 1 to 3 carbon atoms. 5. The method of claim 4,
Wherein the polyorganosiloxane has a weight average molecular weight of from 1,500 to 4,000. A coating composition comprising the polyorganosiloxane of any one of claims 1 to 5 and an organic solvent. The method according to claim 6,
Wherein the coating composition has a refractive index of 1.430 to 1.439. A coating layer formed by applying the coating composition of claim 6 on a substrate. 9. The method of claim 8,
Wherein the coating layer has a pencil hardness of from 1H to 4H.

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