KR101560031B1 - Poly(organosiloxane) - Google Patents

Abstract

The present application relates to polyorganosiloxanes and uses thereof. The polyorganosiloxane of the present application can be used, for example, as an adhesion improver. The polyorganosiloxane of the present application exhibits excellent adhesiveness to various materials including, for example, organic materials, and can be used for forming a composition having excellent optical characteristics and reliability or a cured product thereof. The composition or the cured product thereof can be used, for example, as an encapsulating material for an optical semiconductor device.

Description

Polyorganosiloxane {POLY (ORGANOSILOXANE)}

The present application relates to polyorganosiloxanes and uses thereof.

High brightness products using GaN-based compound semiconductors such as GaN, GaAlN, InGaN and InAlGaN have been obtained as LEDs (Light Emitting Diodes), for example, blue or ultraviolet LEDs having an emission wavelength of about 250 nm to 550 nm. The combination of red and green LEDs with blue LEDs has also enabled the formation of high-quality full color images. For example, a technique of manufacturing a white LED by combining a blue LED or an ultraviolet LED with a phosphor is known. Such LEDs are in widespread use as a light source for a display device such as an LCD (Liquid Crystal Display) or an illumination device.

As an LED encapsulant, an epoxy resin having high adhesiveness and excellent durability is widely used, but an epoxy resin has a low transmittance to light in the range of blue to ultraviolet rays, and the light resistance is poor. Thus, for example, Patent Documents 1 to 3 propose a technique for improving the above.

A silicone resin is known as a material excellent in resistance to light in a low wavelength region. Silicone resins are insufficient in heat resistance and appear sticky on the surface after curing. In order for a silicone resin to be effectively applied to an encapsulant of an LED, properties such as high refractive index, crack resistance, surface hardness, adhesive strength and thermal shock resistance must be secured.

The silicone resin does not show sufficient adhesion to a substrate made of a metal or an organic material. Accordingly, there is a problem that thermal shock is applied after the encapsulation of a device using a silicone resin, or adhesion of the device, or frequent peeling or the like occurs when the device is maintained at a high temperature.

Patent Document 1: JP-A-11-274571 Patent Document 2: JP-A-2001-196151 Patent Document 3: Japanese Patent Application Laid-Open No. 2002-226551

The present application provides polyorganosiloxanes and uses thereof.

Exemplary polyorganosiloxanes may have an average composition formula of the following formula (1).

[Chemical Formula 1]

_{^{(R 1 3 SiO 1/2}} ) a (R 1 2 SiO 2/2) b (R 1 SiO 3/2) c (OR) d

Wherein R ¹ is an epoxy group or a monovalent hydrocarbon group, at least one of R ¹ is an alkenyl group, at least one of R ¹ is an epoxy group, a is 0 or a positive number, b is a positive number, c (B + c) is in the range of 0.4 to 0.97, and R is an alkyl group or a hydrogen atom, and d is 0 or a positive number, and the sum of a, b and c is 1, b /

(OH + OR) / Si) of the total number of moles (Si) of the total silicon atoms of the polyorganosiloxane and the total number of moles (OH + OR) of the total hydroxyl groups and alkoxy groups contained in the polyorganosiloxane may be 0.01 or less .

In the present specification, the polyorganosiloxane is represented by a predetermined average composition formula. It is to be understood that when the polyorganosiloxane is a single component represented by an average composition formula thereof, it is a mixture of two or more components, And the case where the average composition formula is taken may be included.

On the other hand, the term "M unit" in the present specification, a (R ₃ SiO _1/2) is so-called consistent mean-functional siloxane units, and the term "D unit" is (R ₂ SiO _2/2) in the case represented by the means a so-called di-functional siloxane units in the case represented, and the term "T unit" means a so-called trifunctional siloxane unit with the case shown by (RSiO _3/2), and the term "Q unit" is (SiO _{4 / 2} ), which may be referred to as " covalent siloxane unit ". In the above, R is a functional group bonded to a silicon atom (Si), and may be, for example, a hydrogen atom, an epoxy group or a monovalent hydrocarbon group.

As used herein, the term " epoxy group " may refer to a monovalent moiety derived from a cyclic ether or a cyclic ether containing three ring constituent atoms, unless otherwise specified . As the epoxy group, a glycidyl group, an epoxy alkyl group, a glycidoxyalkyl group or an alicyclic epoxy group can be exemplified. The alicyclic epoxy group may mean a monovalent residue derived from a compound containing an aliphatic hydrocarbon ring structure and including a structure in which two carbon atoms forming the aliphatic hydrocarbon ring also form an epoxy group. As the alicyclic epoxy group, an alicyclic epoxy group having 6 to 12 carbon atoms can be exemplified, and for example, 3,4-epoxycyclohexylethyl group and the like can be exemplified.

As used herein, the term " monovalent hydrocarbon group " may mean a monovalent residue derived from a compound consisting of carbon and hydrogen or a derivative of such a compound, unless otherwise specified. For example, the monovalent hydrocarbon group may contain from 1 to 25 carbon atoms. As the monovalent hydrocarbon group, an alkyl group, an alkenyl group, an alkynyl group or an aryl group can be exemplified.

The term "alkyl group" as used herein may mean an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms, unless otherwise specified. The alkyl group may be linear, branched or cyclic. In addition, the alkyl group may be optionally substituted with one or more substituents.

The term "alkenyl group" as used herein may mean an alkenyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms unless otherwise specified. The alkenyl group may be linear, branched or cyclic and may optionally be substituted with one or more substituents.

The term "alkynyl group" as used herein may mean an alkynyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms unless otherwise specified. The alkynyl group may be linear, branched or cyclic and may optionally be substituted with one or more substituents.

In the present specification, the term "aryl group" may mean a monovalent residue derived from a compound or a derivative thereof including a structure in which a benzene ring or two or more benzene rings are condensed or bonded, unless otherwise specified. The range of the aryl group may include a so-called aralkyl group or an arylalkyl group as well as a functional group ordinarily called an aryl group. The aryl group may be, for example, an aryl group having 6 to 25 carbon atoms, 6 to 21 carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms. Examples of the aryl group include a phenyl group, dichlorophenyl, chlorophenyl, phenylethyl, phenylpropyl, benzyl, tolyl, xylyl group or naphthyl group.

Examples of the substituent which may optionally be substituted in the epoxy group or the monovalent hydrocarbon group include halogen such as chlorine or fluorine, epoxy group such as glycidyl group, epoxy alkyl group, glycidoxyalkyl group or alicyclic epoxy group, acryloyl group, An isocyanate group, a thiol group or a monovalent hydrocarbon group, but the present invention is not limited thereto.

A, b and c each represent a molar ratio of the M, D and T units of the polyorganosiloxane, and the sum (a + b + c) is 1. Where a is 0 or a positive number, for example from 0.01 to 0.15, and b is a positive number, for example from 0.65 to 0.97, and c is a positive number, for example, 0.03 to 0.60. The ratio of D units to total D and T units in the polyorganosiloxane, i.e., b / (b + c), can be 0.4 to 0.97 or 0.4 to 0.95. The ratio of D and T units of the polyorganosiloxane can be adjusted as described above, for example, the polyorganosiloxane can be mixed with a composition used as an encapsulating material or an adhesive to exhibit appropriate physical properties.

In the general formula (1), d represents the amount of the hydroxyl group or the alkoxy group contained in the polyorganosiloxane. In formula (1), d is 0 or a positive number. For example, the molar number (Si) of the total silicon atoms of the polyorganosiloxane and the total number of moles (OH + OR) of the total hydroxyl groups and alkoxy groups contained in the polyorganosiloxane (OH + OR) / Si) is 0.01 or less. The lower limit of the ratio ((OH + OR) / Si) may be, for example, zero. When the proportion of the hydroxyl group or the alkoxy group contained in the polyorganosiloxane is adjusted as described above, for example, the polyorganosiloxane may be mixed with the sealing material or the composition for an adhesive to exhibit appropriate physical properties.

The polyorganosiloxane contains at least one aliphatic unsaturated bond or a functional group containing it, for example, an alkenyl group. Therefore, at least one of R ¹ in formula (1) is, for example, may be an alkenyl group. For example, the ratio (Ak / Si) of the mole number (Ak) of the aliphatic unsaturated bond or the functional group containing it to the mole number (Si) of the total silicon atoms contained in the polyorganosiloxane, for example, 0.005 or more, or 0.01 or more. The ratio (Ak / Si) may also be 0.4 or less or 0.3 or less. By controlling the ratio (Ak / Si) to 0.005 or more or 0.01 or more, it is possible to appropriately maintain the reactivity in the composition containing the polyorganosiloxane and prevent the unreacted component from leaking to the surface of the cured product have. Further, by adjusting the ratio (Ak / Si) to 0.4 or less or 0.3 or less, the crack resistance of the cured product containing the polyorganosiloxane can be maintained to be excellent.

The polyorganosiloxane may include at least one epoxy group bonded to a silicon atom. In this case, at least one of R ¹ in Formula 1 may be an epoxy group. For example, the ratio (Ep / Si) of the molar number (Si) of the total silicon atoms contained in the siloxane polymer to the number of moles (Ep) of the epoxy groups bonded to the total silicon atoms contained in the polyorganosiloxane , And 0.05 to 0.4. Within this range, for example, the adhesiveness of the encapsulating material or adhesive compounded with the above-mentioned polyorganosiloxane can be kept excellent.

The polyorganosiloxane may include at least one aryl group, for example, an aryl group bonded to a silicon atom. In this case, at least one of R ¹ in the formula (1) may be an aryl group. For example, the ratio (Ar / Si) of the number of moles (Si) of the total silicon atoms contained in the siloxane polymer to the number of moles (Ar) of the aryl groups bonded to the total silicon atoms contained in the polyorganosiloxane is 0.3 or more, 0.35 or more. The composition containing the polyorganosiloxane within the above range has excellent processability and workability and can be cured to exhibit excellent moisture resistance, light dispersibility, light transmittance and hardness characteristics.

In one example, the polyorganosiloxane may have a viscosity of from 100 cP to 500000 cP or from 100 cP to 100000 cP at 25 占 폚. Within this range, the processability of the composition to which the polyorganosiloxane is applied and the hardness characteristics after curing can be properly maintained.

In one example, the polyorganosiloxane may have a weight average molecular weight (Mw) of about 1,000 to about 100,000 or about 1,500 to about 30,000. The term " weight average molecular weight " means a value converted to standard polystyrene measured by GPC (Gel Permeation Chromatograph). Unless otherwise specifically stated herein, the term molecular weight may mean weight average molecular weight. Within this range, the moldability of the composition to which the polyorganosiloxane is applied and the hardness and strength characteristics after curing can be suitably maintained.

The polyorganosiloxane can be produced, for example, by ring-opening polymerization of a cyclic siloxane compound. For example, the polyorganosiloxane may be a ring opening polymerization reactant of a mixture comprising a cyclic polyorganosiloxane or a component included in the reactant. In this manner, the polyorganosiloxane is produced by a ring-opening polymerization reaction, particularly a ring-opening polymerization reaction of a predetermined raw material to be described later, to easily adjust the length of the linear structure of the polyorganosiloxane to a desired range, / Alkoxy group and the like can be controlled.

For example, the polyorganosiloxane may be a ring-opening polymerization product of a mixture comprising a cyclic compound of formula (2).

(2)

In the formula (2), R ^a and R ^b are each independently an epoxy group or a monovalent hydrocarbon group, and o is 3 to 6.

The specific types of R ^a and R ^b in formula (2) can be adjusted, for example, by considering the structure of the desired polyorganosiloxane.

The mixture to be used in the ring-opening polymerization reaction is a cage-structured polyorganosiloxane, for example, a compound having an average composition formula of the following formula (3) or a polyorganosiloxane having a T unit or a partial cage structure, Of compounds having an average composition formula of < RTI ID = 0.0 >

(3)

[R ^c SiO _3/2]

[Chemical Formula 4]

_{^{[R d R f 2 SiO 1}} /2] p [R c SiO 3/2] q

In the formulas (3) and (4), R ^c to R ^f are each independently an epoxy group or a monovalent hydrocarbon group, p is 1 to 3, and q is 1 to 10. When the polyorganosiloxane of the average composition formula of Formula 4 has a partial cage structure, p may be 1 to 2, and q may be 3 to 10.

In the general formulas (3) and (4), the specific kind of R ^c to R ^f , specific values of p and q, and the ratio of each component in the mixture can be determined by the structure of the desired polyorganosiloxane.

When a cyclic polyorganosiloxane, for example, a compound represented by the general formula (2) is reacted with a polyorganosiloxane having a cage structure and / or a partial cage structure or a T unit, a polyorganosiloxane having a desired structure Can be synthesized with a sufficient molecular weight. In addition, according to the above method, an object having excellent physical properties can be produced by minimizing a functional group such as an alkoxy group or a hydroxy group bonded to a silicon atom in a polyorganosiloxane or a polymerization reaction containing the same.

In one example, the mixture applied to the ring-opening polymerization reaction may further comprise a compound represented by the following formula (5).

[Chemical Formula 5]

(R ^d R ^f ₂ Si) ₂ O

In the general formula (5), R ^d and R ^f are an epoxy group or a monovalent hydrocarbon group.

In the formula (5), the specific kind of the epoxy group or the monovalent hydrocarbon group or the blending ratio in the mixture may be determined according to the objective polyorganosiloxane.

The reaction of each component in the mixture can be carried out in the presence of a suitable catalyst. Thus, the mixture may further comprise a catalyst.

As the catalyst, for example, a base catalyst can be used. Suitable base catalysts include metal hydroxides such as KOH, NaOH or CsOH; Metal silanolates or tetramethylammonium hydroxide, tetraethylammonium hydroxide or tetrapropylammonium hydroxide, which contain an alkali metal compound and a siloxane, and the like, Quaternary ammonium compounds, and the like, but the present invention is not limited thereto.

The proportion of the catalyst in the mixture may be appropriately selected in consideration of the desired reactivity and the like, for example, 0.01 to 30 parts by weight or 0.03 to 5 parts by weight relative to 100 parts by weight of the total weight of the reactants in the mixture Can be included. Unless specifically stated otherwise herein, unit weight refers to the ratio of weight between components.

In one example, the reaction of the mixture can be carried out in the presence of a suitable solvent. As the solvent, any kind can be used as long as the reactants in the mixture, that is, the disiloxane or the polysiloxane, etc., and the catalyst can be properly mixed and the reactivity is not adversely affected. Examples of the solvent include aliphatic hydrocarbon solvents such as n-pentane, i-pentane, n-hexane, i-hexane, 2,2,4-trimethylpentane, cyclohexane or methylcyclohexane; Aromatic solvents such as benzene, toluene, xylene, trimethylbenzene, ethylbenzene or methylethylbenzene, ketones such as methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, Ketone solvents such as methylcyclohexanone and acetylacetone; Propyl ether, isopropyl ether, diglyme, dioxine, dimethyl dioxin, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol diethyl ether, Ether type solvents such as propylene glycol monomethyl ether and propylene glycol dimethyl ether; Ester solvents such as diethyl carbonate, methyl acetate, ethyl acetate, ethyl lactate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate or ethylene glycol diacetate; Amide solvents such as N-methylpyrrolidone, formamide, N-methylformamide, N-ethylformamide, N, N-dimethylacetamide or N, N-diethylacetamide can be exemplified. But is not limited to.

The reaction of the mixture, for example, the ring opening polymerization reaction, can be carried out, for example, by adding and carrying out a catalyst, for example, at a reaction temperature in the range of 0 ° C to 150 ° C or 30 ° C to 130 ° C. In addition, the reaction time can be adjusted within a range of, for example, 1 hour to 3 days.

The present application is also directed to a curable composition comprising said polyorganosiloxane. The curable composition may be used, for example, as a sealing material for optical semiconductor or an adhesive composition containing an LED or the like.

The curable composition may include components that enable it to be cured by hydrosilylation, for example, by reaction of an aliphatic unsaturated bond with a hydrogen atom

For example, the curable composition comprises a polyorganosiloxane (hereinafter referred to as a polyorganosiloxane (A)) having an average composition formula of the following formula (6); And a compound represented by the following formula (7) (hereinafter referred to as a compound (C)) together with the polyorganosiloxane. The polyorganosiloxane may be contained in an amount of 0.01 to 50 parts by weight per 100 parts by weight of the polyorganosiloxane (A) in the curable composition.

[Chemical Formula 6]

_{^{(R 2 3 SiO 1/2}} ) a (R 2 2 SiO 2/2) b (R 2 SiO 3/2) c (SiO 4/2) d

(7)

R ³ _h H _i SiO _{(4-hi) / 2}

Formula 6 and in 7 R ² can be a monovalent hydrocarbon odd, at least one of R ² is an alkenyl group, the sum of a, b, c and d is 1, a is from 0 to 0.5, b is from 0 to 0.8 , c is 0 to 0.8, d is 0 to 0.5, (a + b) / (a + b + c + d) is 0.2 to 0.7, R ³ is a monovalent hydrocarbon group having no aliphatic unsaturated bond For example, an alkyl group or an aryl group, h is 1 to 2.2, i is 0.01 to 1, and the sum (h + i) of h and i is 1 to 3.

A, b, c and d represent molar ratios of siloxane units contained in the polyorganosiloxane (A). A is 0 to 0.5, b is 0 to 0.8, c is 0 to 0.8, d is 0 to 0.5, and (a + b + c + d) ) / (a + b + c + d) may be 0.2 to 0.7. By adjusting the ratio of the siloxane units in this way, appropriate physical properties can be secured according to the application.

The polyorganosiloxane (A) contains at least one aliphatic unsaturated bond or a functional group containing it, for example, an alkenyl group. Accordingly, at least one of R < ² > in formula (6) may be an alkenyl group. For example, the molar number (Ak) of the aliphatic unsaturated bond or the functional group containing it relative to the number of moles (Si) of the total silicon atoms contained in the polyorganosiloxane (A), for example, the ratio of the number of moles of alkenyl groups (Ak / Si) may be 0.01 or more or 0.05 or more. The ratio (Ak / Si) may also be 0.4 or less or 0.35 or less. By adjusting the ratio (Ak / Si) to 0.01 or more or 0.05 or more, it is possible to maintain the reactivity appropriately and to prevent the unreacted component from leaking to the surface of the cured product. Further, by controlling the ratio (Ak / Si) to 0.4 or less or 0.35 or less, the crack resistance of the cured product can be maintained to be excellent.

The polyorganosiloxane (A) may contain at least one aryl group, for example, an aryl group bonded to a silicon atom. In this case, at least one of R < ² > in formula (6) may be an aryl group. The number of moles (Si) of the total silicon atoms contained in the siloxane (A) and the number of moles of the aryl group bonded to the total silicon atoms contained in the polyorganosiloxane (A), for example, (Ar / Si) may be 0.3 to 1.5 or 0.3 to 1.2. As a result, the composition has excellent processability and workability and can be cured to exhibit excellent moisture resistance, light dispersibility, light transmittance and hardness characteristics.

In one example, the polyorganosiloxane (A) may have a viscosity at 25 ° C of at least 2,000 cP, at least 3,000 cP, at least 4,000 cP, at least 5,000 cP, at least 7,000 cP, at least 9,000 cP, or at least 9,500 cP. Within this range, the processability of the curable composition and the hardness characteristics after curing can be suitably maintained. The upper limit of the viscosity is not particularly limited. For example, the viscosity may be 100,000 cP or less, 90,000 cP or less, 80,000 cP or less, 70,000 cP or 65,000 cP or less.

The molecular weight of the polyorganosiloxane (A) may be, for example, about 800 to 50,000 or 800 to 30,000. Within this range, the moldability of the curable composition and the hardness and strength characteristics after curing can be appropriately maintained.

The polyorganosiloxane (A) can be prepared by applying a conventional method known in the art of producing a polyorganosiloxane or by ring-opening polymerization for producing the polyorganosiloxane.

The curable composition may further include, for example, a polyorganosiloxane having an average composition formula represented by the following formula (8). The polyorganosiloxane having an average composition formula of the formula (8) (hereinafter, the polyorganosiloxane (B)) may be, for example, a crosslinking type polyorganosiloxane. The term " cross-linked polyorganosiloxane " may mean a polyorganosiloxane that necessarily contains a T unit or Q unit as the siloxane unit.

[Chemical Formula 8]

_{^{(R 4 3 SiO 1/2}} ) e (R 4 2 SiO 2/2) f (R 4 SiO 3/2) g (SiO 4/2) h

In Formula (8), R ⁴ is each independently an epoxy group or a monovalent hydrocarbon group, at least one of R ⁴ is an alkenyl group, the sum of e, f, g and h is 1, e is 0 or a positive number, f (E + f) / (e + f + g + h) is in the range of 0.2 to 0.7, and f / f + g + h) is 0.4 or less, and g / (g + h) is 0.8 or more.

In formula (8), at least one or two or more of R ⁴ may be an alkenyl group. In one example, the ratio (Ak / Si) of the number of moles (Ak) of the alkenyl group to the number of moles (Si) of the total silicon atoms contained in the polyorganosiloxane (B) may be 0.05 or more or 0.15 or more. The ratio (Ak / Si) may also be 0.4 or less, 0.35 or less, or 0.3 or less. By controlling the molar ratio (Ak / Si) to 0.05 or more or 0.15 or more, it is possible to maintain the reactivity appropriately and prevent the unreacted components from leaking out to the surface of the cured product. Further, by controlling the molar ratio (Ak / Si) to 0.4 or less, 0.35 or less or 0.3 or less, it is possible to maintain excellent hardness characteristics, crack resistance, thermal shock resistance, and the like.

The polyorganosiloxane (B) may contain at least one aryl group, or may not contain an aryl group. For example, it is possible to control the relationship of the refractive index between the components by controlling the inclusion of the aryl group and / or the ratio thereof. In the case of including an aryl group, at least one of R < ⁴ > in formula (8) may be an aryl group. In the above case, for example, the ratio (Ar / Si) of the number of moles (Ar) of the aryl group to the number of moles (Si) of the total silicon atoms of the polyorganosiloxane (B) 1.1. The refractive index, the gas permeability, the water permeability, the thermal shock resistance, the crack resistance, and the hardness characteristics of the cured product are controlled while the molar ratio (Ar / Si) is adjusted as described above and the refractive index relationship with the polyorganosiloxane (A) And the viscosity of the composition can be appropriately maintained.

E, f, g and h represent molar ratios of respective siloxane units, and when the sum is converted into 1, e is 0 or a positive number such as 0 to 0.5 or 0.05 to 0.5 and f is 0 or a positive number such as 0 to 0.5 or 0 to 0.3 and g is 0 or a positive number such as 0 to 0.95 or 0.2 to 0.95 or 0.2 to 0.85, Or a positive number, for example from 0 to 0.3 or from 0 to 0.2. (E + f) / (e + f + g + h) in the average composition formula (Formula 8) of the polyorganosiloxane (B) is 0.2 to 0.7 and f / (f + g + h) , and g / (g + h) may be 0.8 or more. When the ratio of M, D, T, and Q units is controlled within this range, a composition that exhibits excellent workability and workability and is cured to provide a composition having excellent physical properties such as hardness, crack resistance, and thermal shock resistance.

The polyorganosiloxane (B) may have a viscosity of 5,000 cP or more, or 1,000,000 cP or more at 25 占 폚, so that the workability before curing and the hardness characteristics after curing can be appropriately maintained.

Further, the polyorganosiloxane (B) may have a molecular weight of, for example, 800 to 100,000 or 1,000 to 100,000. By controlling the molecular weight to 800 or more, the moldability before curing and the strength after curing can be effectively maintained, and the viscosity and the like can be maintained at an appropriate level by controlling the molecular weight to 100,000 or less.

The polyorganosiloxane (B) can be produced, for example, by applying a conventionally known method for producing a polyorganosiloxane, or by applying the ring-opening polymerization method described above.

The polyorganosiloxane (B) may be contained in an amount of, for example, 50 parts by weight to 700 parts by weight or 50 parts by weight to 500 parts by weight based on 100 parts by weight of the polyorganosiloxane (A).

The compound of the formula (7) is a silicon compound (compound (C)) containing a hydrogen atom bonded to a silicon atom, and in the formula (7), the silicon compound (C) may be an average composition formula. The silicon compound (C) may have at least one or at least two hydrogen atoms bonded to silicon atoms.

The silicon compound (C) can act as a crosslinking agent for crosslinking the composition by reacting with an aliphatic unsaturated bond-containing functional group of the polyorganosiloxane. For example, the hydrogen atom of the silicon compound (C) may undergo addition reaction with an aliphatic unsaturated bond such as an alkenyl group of the polyorganosiloxane (A) and / or the polyorganosiloxane (B), and crosslinking and curing may proceed.

In one example, the ratio (H / Si) of the number of moles (H) of the hydrogen atoms bonded to silicon atoms to the number of moles (Si) of the total silicon atoms of the silicon compound (C) . The ratio (H / Si) may be 0.8 or less or 0.75 or less. It is possible to control the molar ratio (H / Si) to not less than 0.2 or not less than 0.3 so as to maintain excellent curability of the composition, and to adjust the ratio to not more than 0.8 or not more than 0.75 to maintain excellent crack resistance and thermal shock resistance .

The silicon compound (C) may comprise at least one aryl group, and in this case at least one of R ³ in formula (7) may be an aryl group. The ratio (Ar / Si) of the number of moles (Ar) of the aryl group to the number of moles (Si) of the total silicon atoms contained in the silicon compound (C) is 0.3 to 1.5 or 0.3 To 1.2. It is possible to maximize the refractive index and hardness characteristics of the cured product while maintaining the molar ratio (Ar / Si) as described above, while maintaining the relationship between the refractive index and the refractive index with respect to the polyorganosiloxane (A) .

The silicon compound (C) may have a viscosity of 0.1 cP to 100,000 cP, 0.1 cP to 10,000 cP, 0.1 cP to 1,000 cP or 0.1 cP to 300 cP at 25 캜. With the above viscosity, the processability of the composition and the hardness of the cured product can be kept excellent.

Further, the silicon compound (C) may have a molecular weight of, for example, less than 2,000, less than 1,000, or less than 800. If the molecular weight of the silicon compound (C) is 1,000 or more, the strength of the cured product may be lowered. The lower limit of the molecular weight of the silicon compound (C) is not particularly limited, and may be 250, for example. The molecular weight of the silicon compound (C) may be a weight average molecular weight or may mean a conventional molecular weight of a compound.

The method for producing the silicon compound (C) is not particularly limited, and for example, it can be prepared by applying a conventionally known method to the production of a polyorganosiloxane, or by applying a method similar to that of the polyorganosiloxane (A) have.

The silicon compound (C) can be obtained, for example, from the polyorganosiloxane (A), the polyorganosiloxane (A) containing the polyorganosiloxane (A) and the polyorganosiloxane A hydrogen atom bonded to a silicon atom contained in the silicon compound (C) with respect to the total number of aliphatic unsaturated bonds contained in the organosiloxane and the polyorganosiloxane (B) or a functional group containing the same, for example, the number of moles (Ak) (H / Ak) of the number of moles (H) of the curable composition to the curable composition is 0.5 or more or 0.7 or more. The silicon compound (C) may be contained in the curable composition such that the ratio (H / Ak) is 2.0 or less or 1.5 or less. As a result, it is possible to provide a composition that exhibits excellent workability and workability before curing, exhibits excellent curing resistance, hardness characteristics, thermal shock resistance and adhesiveness, and does not cause cloudiness or surface stickiness under severe conditions have.

The curable composition may further comprise a hydrosilylation catalyst. The hydrosilylation catalyst may be used to promote the hydrogen silylation reaction. As the hydrosilylation catalyst, any of common components known in the art can be used. Examples of such catalysts include platinum, palladium or rhodium catalysts. In the present application, a platinum-based catalyst can be used in consideration of catalytic efficiency and the like. Examples of such catalysts include chloroplatinic acid, platinum tetrachloride, an olefin complex of platinum, an alkenylsiloxane complex of platinum or a carbonyl complex of platinum. But is not limited thereto.

The content of the hydrosilylation catalyst is not particularly limited as long as it is contained in the so-called catalytic amount, that is, the amount that can act as a catalyst. Typically, it can be used in an amount of 0.1 ppm to 500 ppm or 0.2 ppm to 100 ppm based on the atomic weight of platinum, palladium or rhodium.

The curable composition may further include, in addition to the polyorganosiloxane, a further adhesive property-imparting agent in view of further improvement of adhesiveness to various substrates. The adhesive property-imparting agent is a component capable of improving the self-adhesiveness, and can improve the self-adhesiveness particularly to metals and organic resins.

Examples of the adhesion-imparting agent include at least one kind selected from the group consisting of an alkenyl group such as vinyl group, a (meth) acryloyloxy group, a hydrosilyl group (SiH group), an epoxy group, an alkoxy group, an alkoxysilyl group, a carbonyl group, Or silanes having two or more functional groups; Or an organosilicon compound such as cyclic or linear siloxane having 2 to 30 or 4 to 20 silicon atoms, but the present invention is not limited thereto. In the present application, one kind or more than two types of adhesion-imparting agents as described above may be further mixed and used.

When the adhesive property-imparting agent is included in the composition, for example, the total weight of the other compounds contained in the curable composition, for example, the above-mentioned polyorganosiloxane (A), the polyorganosiloxane (B) and / May be contained in an amount of 0.1 part by weight to 20 parts by weight based on 100 parts by weight of the resin. However, the content may be appropriately changed in consideration of the desired adhesiveness improving effect and the like.

The curable composition may contain, if necessary, 2-methyl-3-butyne-2-ol, 2-phenyl-3-1- 3-hexen-1-yne, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane or ethynylcyclohexane; Inorganic fillers such as silica, alumina, zirconia or titania; A carbon functional silane having an epoxy group and / or an alkoxysilyl group, a partial hydrolysis condensation product thereof, or a siloxane compound; A thixotropy imparting agent such as pyrogenic silica which can be used in combination with polyether and the like; Silver, a metal powder such as copper or aluminum, or a conductivity imparting agent such as various carbon materials; A coloring agent such as a pigment or a dye, and the like.

The curable composition may also comprise particles, for example, inorganic particles. The particles may satisfy the following expression (1).

[Equation 1]

| P - Q | 0.1

In the formula (1), P is the refractive index of the curable composition or its cured product excluding the particles, and Q is the refractive index of the particle. The refractive index may be, for example, a refractive index for light having a wavelength of 450 nm. The absolute value of the difference between P and Q may be 0.08 or less, 0.07 or less, or 0.05 or less in another example.

The particles can prevent sedimentation of, for example, a phosphor that can be incorporated into the curable composition, and improve heat resistance, heat resistance, crack resistance, and the like, thereby improving overall reliability. In addition, the particles can maintain the transparency of the composition or the cured product while performing the above-described action, for example, to improve the brightness of the device.

As the particles, any of various kinds of particles used as a filler in the industry can be used as long as Formula (1) is satisfied. In one example, particles having a refractive index (Q) of 1.40 or more, 1.45 or more, 1.48 or more, or 1.50 or more and 1.55 or more can be used.

Particles with, for example, silica (SiO _2), organo-silica, alumina, aluminosilicate, silica, titanate, or zirconia, cerium oxide, hafnium oxide, pentoxide, niobium, tantalum pentoxide, indium oxide, tin oxide, indium tin oxide , Zinc oxide, silicon, zinc sulfide, calcium carbonate, barium sulfate, aluminosilicate, or magnesium oxide, which may be in the form of a porous or hollow particle.

The average particle size of the particles may be, for example, 1 nm to 50 占 퐉 or 2 nm to 10 占 퐉. With the average particle diameter of 1 nm or more, the particles can be uniformly dispersed in the composition or the cured product thereof, and furthermore, when the particle diameter is 50 m or less, the particles can be effectively dispersed and the sedimentation of the particles can be prevented.

The particles may be contained in the composition in an amount of 0.1 to 30 parts by weight or 0.2 to 10 parts by weight based on 100 parts by weight of the total weight of the polyorganosiloxane (A) or the polyorganosiloxane (B) and the silicon compound (C) . The content of the particles is not less than 0.1 part by weight and the effect of suppressing sedimentation of an excellent phosphor or improving the reliability of the device can be ensured and if it is 30 parts by weight or less,

The curable composition may further comprise a phosphor. The kind of the phosphor that can be used is not particularly limited, and for example, a conventional type of phosphor applicable to the LED package for the purpose of implementing white light may be used.

The present application also relates to semiconductor devices, for example, optical semiconductor devices. Exemplary semiconductor devices may be encapsulated by an encapsulant comprising a cured product of the curable composition. Examples of the semiconductor device sealed with the encapsulation material include a diode, a transistor, a thyristor, a photocoupler, a CCD, a solid-state image pickup element, a monolithic IC, a hybrid IC, an LSI, a VLSI and an LED (Light Emitting Diode). In one example, the semiconductor element may be a light emitting diode.

As the light emitting diode, for example, a light emitting diode formed by laminating a semiconductor material on a substrate can be exemplified. Examples of the semiconductor material include, but are not limited to, GaAs, GaP, GaAlAs, GaAsP, AlGaInP, GaN, InN, AlN, InGaAlN or SiC. As the substrate, sapphire, spinel, SiC, Si, ZnO, or GaN single crystal may be exemplified.

Further, at the time of manufacturing the light emitting diode, a buffer layer may be formed between the substrate and the semiconductor material, if necessary. As the buffer layer, GaN or AlN or the like can be used. The method for laminating the semiconductor material on the substrate is not particularly limited, and for example, MOCVD, HDVPE, or liquid phase growth can be used. Further, the structure of the light emitting diode may be, for example, a mono junction having a MIS junction, a PN junction, a PIN junction, a heterojunction, a double heterojunction, or the like. In addition, the light emitting diode can be formed with a single or multiple quantum well structure.

In one example, the emission wavelength of the light emitting diode may be, for example, 250 nm to 550 nm, 300 nm to 500 nm, or 330 nm to 470 nm. The emission wavelength may mean the main emission peak wavelength. By setting the emission wavelength of the light emitting diode to the above range, a white light emitting diode having a longer lifetime, high energy efficiency and high color reproducibility can be obtained.

The light emitting diode may be encapsulated using the above composition. Encapsulation of the light emitting diode can be carried out only with the above composition, and in some cases other encapsulant can be used in combination with the composition. In the case of using two types of sealing materials together, after sealing with the composition, the surroundings may be sealed with another sealing material, or the sealing material may be first sealed with another sealing material, and then the periphery thereof may be sealed with the composition. Examples of other sealing materials include epoxy resins, silicone resins, acrylic resins, urea resins, imide resins, and glass.

Examples of the method for encapsulating the light emitting diode with the curable composition include a method in which the composition is previously injected into a molded mold, the lead frame or the like having the light emitting diode fixed thereto is immersed in the mold and the composition is cured, A method in which a composition is injected into a mold and cured is used. As a method of injecting the composition, injection by a dispenser, transfer molding, injection molding, or the like can be exemplified. Examples of other sealing methods include a method in which a composition is dropped on a light emitting diode, applied by screen printing, screen printing or a mask to cure the composition, or a cup in which a light emitting diode is disposed on the bottom, And a method of curing can be used.

The curable composition may also be used as a die bond material for fixing the light emitting diode to the lead terminal or the package, a passivation film on the light emitting diode or a package substrate, if necessary.

When curing of the composition is required, the curing method is not particularly limited and may be carried out by, for example, holding the composition at a temperature of 60 to 200 DEG C for 10 minutes to 5 hours, The stepwise curing process may be performed through the above process.

The shape of the encapsulant is not particularly limited and can be, for example, a lens-like lens shape, a plate shape or a thin film shape.

Further, it is possible to further improve the performance of the light emitting diode according to a conventionally known method. As a method of improving the performance, for example, a method of providing a reflective layer or a condensed layer of light on the back surface of a light emitting diode, a method of forming a complementary coloring portion on the bottom portion, a method of providing a layer absorbing light having a shorter wavelength than the main emission peak on a light emitting diode A method in which a light emitting diode is encapsulated and then further molded with a hard material, a method in which a light emitting diode is inserted and fixed in a through hole, a method in which a light emitting diode is connected to a lead member or the like by flip chip connection or the like, And the like.

The optical semiconductor, for example, a light emitting diode can be used as a light source such as a backlight of a liquid crystal display (LCD), an illumination, various sensors, a printer, a copying machine, a vehicle instrument light source, A display device, a light source of a planar light-emitting body, a display, a decoration, or various lights.

The polyorganosiloxane of the present application can be used, for example, as an adhesion improver. The polyorganosiloxane of the present application exhibits excellent adhesiveness to various materials including, for example, organic materials, and can be used for forming a composition having excellent optical characteristics and reliability or a cured product thereof. The composition or the cured product thereof can be used, for example, as an encapsulating material for an optical semiconductor device.

Hereinafter, the polyorganosiloxane and the curable composition will be described in more detail with reference to Examples and Comparative Examples, but the scope of the polyorganosiloxane and the like is not limited by the following examples. In the present embodiment, Vi represents a vinyl group, Ph represents a phenyl group, Me represents a methyl group, and Ep represents a 3-glycidoxypropyl group.

1. Evaluation of device characteristics

The device characteristics are evaluated using a 6030 LED package made of polyphthalamide (PPA). The curable composition is dispensed in a polyphthalamide cup, held at 70 DEG C for 30 minutes, and then held at 150 DEG C for 1 hour to cure to produce a surface mount LED.

Thereafter, the thermal shock test and the long-term reliability test are performed according to the following method.

(One) Thermal shock  Test

The LED was maintained at -40 占 폚 for 30 minutes and again maintained at 100 占 폚 for 30 minutes. The LED was repeated 10 times, i.e., 10 times, and maintained at room temperature. . At the time of evaluation, the above-mentioned tests were carried out for each of 10 LEDs made from the same curable composition, and the number of LEDs that were peeled off is shown in Table 1 below.

(2) Long-term reliability test

The LED is operated for 200 hours with a current of 30 mA while maintaining the condition at 85 ° C and 85% relative humidity. Next, the rate of decrease of the latter luminance after the above operation relative to the initial luminance before the operation is measured and evaluated according to the following criteria.

<Evaluation Criteria>

○: The luminance reduction ratio to the initial luminance is 10% or less

X: The luminance reduction ratio with respect to the initial luminance exceeds 10%

2. To polyorganosiloxane  About ^One H- NMR  Measure

¹ H-NMR analysis of the polyorganosiloxane was carried out under the following conditions.

< ¹ H-NMR analysis content>

Measuring instrument: Varian Unity Inova 500 MHz NMR

Solvent used: acetone-d6

Measuring conditions:

Pulse sequence: s2pul

Sweep width: 8012.8hz

Acquisition time: 2.045 sec

Delay time: 2 sec

Pulse width: 45 degree pulse (8.10 μsec)

Number of scan: 16

Synthetic example  One.

To a mixture of 60 g of octamethylcyclotetrasiloxane, 106.96 g of octaphenylcyclotetrasiloxane and 44.96 g of Ep-POSS (octaglycidyldimethylsilyl POSS, EP0435, Hybrid Plastics) was added divinyltetramethyldisiloxane 15.7 g and 0.73 mL of tetramethylammonium hydroxide (TMAH). Thereafter, the mixture was reacted at a temperature of 115 캜 for about 20 hours. After completion of the reaction, the low-molecular substances were removed from the reaction product to obtain a transparent oil-form polysiloxane (A) having an average composition formula of the following formula (A). The viscosity of the polysiloxane (A) at 28 ° C was 28,300 cP and the molecular weight (Mw) was 4,500. Further, no peak derived from an alkoxy group or a hydroxy group (silanol) was observed in the spectrum measured by ¹ H-NMR of the polysiloxane (A).

(A)

_{[ViMe 2 SiO 1/2]} 0.05 [Me 2 SiO 2/2] 0.49 [Ph 2 SiO 2/2] 0.31 [EpSiO 3/2] 0.15

Synthetic example  2.

The amount of ep-POSS (octaglycidyldimethylsilyl POSS, EP0435, Hybrid Plastics) was changed to 22.48 g, the amount of divinyltetramethyldisiloxane was changed to 12.54 g, the amount of tetramethylammonium hydroxide (TMAH) was changed to 0.65 mL, the reaction was carried out in the same manner as in Synthesis Example 1 to obtain a polysiloxane (B) having an average composition formula of the following formula (B). The viscosity of the polysiloxane (B) at 25 캜 was 19,500 cP and the molecular weight (Mw) was about 6,100. Further, no peak derived from an alkoxy group or a hydroxy group (silanol) was observed in the spectrum measured by ¹ H-NMR of the polysiloxane (B).

[Chemical Formula B]

_{[ViMe 2 SiO 1/2]} 0.05 [Me 2 SiO 2/2] 0.50 [Ph 2 SiO 2/2] 0.34 [EpSiO 3/2] 0.11

Synthetic example  3.

Except that octamethylcyclotetrasiloxane and octaphenylcyclotetrasiloxane were not used and instead 183.71 g of tetramethyltetraphenylcyclotetrasiloxane was used and the amount of divinyltetramethyldisiloxane was changed to 12.10 g The reaction was allowed to proceed in the same manner as in Synthesis Example 1 to obtain a polysiloxane (C) having an average composition formula of the following formula (C). The viscosity of the polysiloxane (C) at 25 캜 was 17,400 cP and the molecular weight (Mw) was about 4,400. Further, no peak derived from an alkoxy group or a hydroxy group (silanol) was observed on the spectrum measured by ¹ H-NMR of the polysiloxane (C).

&Lt; RTI ID = 0.0 &

_{[ViMe 2 SiO 1/2]} 0.05 [PhMeSiO 2/2] 0.84 [EpSiO 3/2] 0.11

Synthetic example  4.

The amount of epovinyltetramethyldisiloxane was changed to 41.75 g, and the amount of tetramethylammonium hydroxide (TMAH) was changed to 1.06 (g / mol) by changing the amount of Ep-POSS (octaglycidyldimethylsilyl POSS, EP0435, Hybrid Plastics) mL, the reaction was carried out in the same manner as in Synthesis Example 1 to obtain a polysiloxane (D) having an average composition formula of the following formula (D). The polysiloxane (D) had a viscosity of 3,780 cP at 25 ° C and a molecular weight (Mw) of about 4,300. Further, no peak derived from an alkoxy group or a hydroxy group (silanol) was observed on the spectrum measured by ¹ H-NMR of the polysiloxane (D).

[Chemical Formula D]

_{[ViMe 2 SiO 1/2]} 0.14 [Me 2 SiO 2/2] 0.32 [Ph 2 SiO 2/2] 0.24 [EpSiO 3/2] 0.30

compare Synthetic example  One.

The reaction was carried out in the same manner as in Synthesis Example 1 except that Ep-POSS was not used and 63.54 g of (3-glycidoxypropyl) trimethoxysilane was used. The polyorganosiloxane produced in the obtained reaction product was similar to the low molecular weight cyclic compound contained in the reactant and thus could not be separated. As a result of ¹ H-NMR measurement, the ratio ((OR + OH) / Si) of the alkoxy group (methoxy group) to the silicon atom of the hydroxy group was 0.16.

compare Synthetic example  2.

106.0 g of water and 8.6 mL of nitric acid were added to a solution of 97.27 g of dimethoxydimethylsilane, 131.81 g of dimethoxydiphenylsilane and 12.54 g of divinyltetramethyldisiloxane in 130 g of toluene, Lt; / RTI &gt; After the reaction, the solution was cooled to room temperature, washed with water until it became neutral, and 31.77 g of (3-glycidoxypropyl) trimethoxysilane and 0.2 g of KOH were added to conduct a dehydration condensation reaction. After the reaction, the reaction product was neutralized with AcOH, washed with water until neutral, and then the solvent was removed by distillation under reduced pressure. The resulting polyorganosiloxane in the reaction product was in the form of an oil having no transparency and contained a large amount of the cyclic low molecular weight compound and the molecular weight of the obtained polyorganosiloxane was similar to that of the low molecular weight cyclic compound contained in the reactant, . As a result of ¹ H-NMR measurement, the ratio ((OR + OH) / Si) of the alkoxy group (methoxy group) to the silicon atom of the hydroxyl group was 0.015.

Example  One

100 g of the polyorganosiloxane of the following formula E, 200 g of the polyorganosiloxane of the following formula F, 50 g of the polyorganosiloxane of the formula G and 5 g of the polyorganosiloxane having the average composition formula of the formula A prepared in the above Synthesis Example 1 , And a catalyst (Platinum (0) -1,3-divinyl-1,1,3,3-tetramethyldisiloxane) was added thereto so that the content of Pt (0) was 5 ppm and uniformly mixed to prepare a curable composition .

(E)

_{(ViMe 2 SiO 1/2)} 2 (Me 2 SiO 2/2) 20 (Ph 2 SiO 2/2) 10

[Chemical Formula F]

_{(ViMe 2 SiO 1/2)} 2 (Ph 2 SiO 2/2) 8

[Formula G]

_{(HMe 2 SiO 1/2)} 2 (HMeSiO 2/2) 0.5 (Ph 2 SiO 2/2) 1.5

Example 2.

A curable composition was prepared in the same manner as in Example 1, except that 20 g of the polyorganosiloxane having the average composition formula of the formula (B) prepared in Synthesis Example 2 was used instead of the polyorganosiloxane of the average composition formula of the Formula (A).

Example 3.

A curable composition was prepared in the same manner as in Example 1, except that 20 g of a polyorganosiloxane having an average composition formula of the formula C prepared in Synthesis Example 3 was used instead of the polyorganosiloxane having an average composition formula of the Formula A.

Example 4.

A curable composition was prepared in the same manner as in Example 1, except that 20 g of a polyorganosiloxane having an average composition formula of the formula (D) prepared in Synthesis Example 4 was used instead of the polyorganosiloxane having an average composition formula of the Formula (A).

Comparative Example  One.

A curable composition was prepared in the same manner as in Example 1 except that the polyorganosiloxane having the average composition formula of the formula (A) was not used.

Comparative Example  2

A curable composition was prepared in the same manner as in Example 2, except that the polyorganosiloxane having the average composition formula of the formula (B) was not used.

Comparative Example  3

A curable composition was prepared in the same manner as in Example 1, except that the polyorganosiloxane having the average composition formula of the formula (A) was not used and the reactant obtained in Comparative Synthesis Example 1 was used instead.

Comparative Example  4

A curable composition was prepared in the same manner as in Example 1, except that the polyorganosiloxane having the average composition formula of the formula (A) was not used and the reaction product obtained in Comparative Synthesis Example 2 was used instead.

Thermal shock test Heat-resistant property Example 1 0/10 ○ Example 2 0/10 ○ Example 3 0/10 ○ Example 4 0/10 ○ Comparative Example 1 10/10 × Comparative Example 2 10/10 × Comparative Example 3 5/10 × Comparative Example 4 6/10 ×

Claims (16)

A polyorganosiloxane having an average composition formula represented by the following formula (1) and having a molar ratio (Si) of the total silicon atoms and a total molar number (OH + OR) of the total hydroxyl group and alkoxy group (OH + OR)
[Chemical Formula 1]
(R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b (R ¹ SiO _3/2 ) _c (OR) _d
In Formula 1, R ¹ is an epoxy group, a C 1 -C 20 alkyl group, having 2 to 20 carbon atoms are alkenyl groups, aryl Kii of C2 to C20 alkynyl group or a carbon number of 6 to 25 of the, at least one of R ¹ has a carbon number of 2 to and alkenyl groups of 20, at least one of R ¹ is an epoxy group, a is a positive number is 0 or a positive number, b is a, c is a positive number, and d is 0 or a positive number, a, b And c are 1, b / (b + c) is 0.4 to 0.97, and R is an alkyl group having 1 to 20 carbon atoms or a hydrogen atom. The polyorganosiloxane according to claim 1, wherein the ratio (Ak / Si) of the number of moles (Ak) of alkenyl groups having 2 to 20 carbon atoms to the number of moles (Si) of the total silicon atoms is 0.005 to 0.4. The polyorganosiloxane according to claim 1, wherein the ratio (Ep / Si) of the molar number (Si) of the total silicon atoms to the number of moles (Ep) of epoxy groups bonded to the total silicon atoms is 0.05 to 0.4. The polyorganosiloxane according to claim 1, which comprises at least one aryl group having 6 to 25 carbon atoms bonded to a silicon atom. The polyorganosiloxane according to claim 4, wherein the ratio (Ar / Si) of the number of moles (Si) of the total silicon atoms to the number of moles (Ar) of the aryl groups having 6 to 25 carbon atoms bonded to the total silicon atoms is 0.3 or more. The polyorganosiloxane according to claim 1, wherein the weight average molecular weight is 1,000 to 100,000. The polyorganosiloxane as claimed in claim 1, which is a ring-opening polymerization product of a mixture comprising a compound of the following formula:
(2)

Wherein R ^a and R ^b are each independently an epoxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 25 carbon atoms, o is 3 Lt; / RTI &gt; 8. The polyorganosiloxane according to claim 7, wherein the mixture further comprises a polyorganosiloxane having an average composition formula of the following formula 3 or 4:
(3)
[R ^c SiO _3/2 ]
[Chemical Formula 4]
[R ^d R ^f ₂ SiO _1/2 ] _p [R ^c SiO _3/2 ] _q
R ^c , R ^d and R ^f are independently an epoxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 25 carbon atoms , P is 1 to 3, and q is 1 to 10. 8. The polyorganosiloxane according to claim 7, wherein the mixture further comprises a compound represented by the following formula
[Chemical Formula 5]
(R ^d R ^f ₂ Si) ₂ O
In the formula (5), R ^d and R ^f are an epoxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 25 carbon atoms. A curable composition comprising the polyorganosiloxane of claim 1. 11. The composition of claim 10, further comprising: a polyorganosiloxane having an average composition formula of the following formula (6); And &lt; RTI ID = 0.0 &gt; (7) &lt; / RTI &gt;
[Chemical Formula 6]
(R ² ₃ SiO _1/2 ) _a (R ² ₂ SiO _2/2 ) _b (R ² SiO _3/2 ) _c (SiO _4/2 ) _d
(7)
R ³ _h H _i SiO _{(4-hi) / 2}
In Formula 6 and 7 R ² is being aryl odd having 1 to 20 carbon alkyl group, a C2 to C20 alkenyl groups, C2 to C20 alkynyl group or a carbon number of 6 to 25 of the, at least one of R ² is C 2 A, b, c and d are 1, a is 0 to 0.5, b is 0 to 0.8, c is 0 to 0.8, d is 0 to 0.5, (a + b) / (a a + b + c + d) is 0.2 to 0.7, R ³ is c 1 -C 20 alkyl group or an aryl group having 6 to 25, h is from 1 to 2.2, i is from 0.01 to 1, and the sum (h + i) of h and i is 1 to 3. The curable composition according to claim 11, wherein the polyorganosiloxane having an average composition formula of Formula (1) is contained in an amount of 0.01 to 50 parts by weight based on 100 parts by weight of the polyorganosiloxane having an average composition formula of Formula (2). 12. The curable composition of claim 11, further comprising a polyorganosiloxane of average compositional formula:
[Chemical Formula 8]
(R ⁴ ₃ SiO _1/2 ) _e (R ⁴ ₂ SiO _2/2 ) _f (R ⁴ SiO _3/2 ) _g (SiO _4/2 ) _h
In the formula 8 R ⁴ are each independently selected from an epoxy group, a C 1 -C 20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group or a C 6 -C 25 aryl group, and at least one of R ⁴ are carbon atoms E is 0 or a positive number, f is 0 or a positive number, g is 0 or a positive number, h is an integer of 0 to 2, (F + g + h) is 0.4 or less, g / (g + h) is 0 or a positive number, and (e + f) / (e + f + g + h) 0.8 or more. A cured optical semiconductor encapsulated with the curable composition of claim 10. A liquid crystal display comprising the optical semiconductor of claim 14 in a backlight unit. A lighting fixture comprising the optical semiconductor of claim 14.