KR20200103548A - Addition-curable silicone composition, cured silicone for optical reflective material, optical reflective material, and optical semiconductor device - Google Patents

Abstract

The present invention provides an addition-curable silicone composition having high fluidity, which provides a cured product having excellent light reflection performance even in a thin film. The addition-curable silicone composition comprises: (A) a specific linear organopolysiloxane; (B) a specific three-dimensional network organopolysiloxane resin; (C) a specific organohydrogenpolysiloxane; (D) a hydrosilylation catalyst comprising a platinum group metal; and (E) a compound represented by chemical formula (2) in a specific amount. In the chemical formula, R3 is independently an alkoxy group, R4 is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.

Description

Addition-curable silicone composition, silicone cured material for light reflecting material, light reflecting material, and light semiconductor device {ADDITION-CURABLE SILICONE COMPOSITION, CURED SILICONE FOR OPTICAL REFLECTIVE MATERIAL, OPTICAL REFLECTIVE MATERIAL, AND OPTICAL SEMICONDUCTOR DEVICE}

The present invention relates to an addition curable silicone composition, a silicone cured product for a light reflecting material, a light reflecting material, and an optical semiconductor device.

In recent years, optical semiconductor elements such as light-emitting diodes (hereinafter referred to as "LEDs") are widely used as indicators and light sources because they emit light with high efficiency and have excellent driving characteristics and lighting repetition characteristics. In particular, white LEDs are widely applied as backlights for display devices and flashes for cameras, and are also employed in lighting applications. In such a light emitting device, a material that reflects emitted light is mounted in order to increase the light extraction efficiency in the irradiation direction.

Lead frames used in LEDs are often equipped with a function of reflecting light while passing current. Specifically, silver plating having good light reflectance is preferably used.

However, silver plating has a problem that oxidation or sulfidation is caused by contact with gas from the outside, and reflectance is liable to decrease. In order to prevent corrosion by gas from the outside, gold plating or aluminum is sometimes used, but both have a problem that the reflectance of visible light is low.

Further, light-reflecting resin, ceramic, or the like is used as the insulating member, and a function of reflecting light is also required for the portion thereof, but the light reflectance is not necessarily high.

In order to solve this problem, a method of thinly coating a resin having a high light reflectance on a lead frame or an insulating member can be considered (hereinafter referred to as "white coating material").

In Patent Documents 1 and 2, a light reflecting material having an epoxy resin and a metal oxide as constituent components is proposed. However, these materials are inferior in high temperature durability and light durability compared to a cured product containing a silicone resin and a metal oxide.

In Patent Documents 3 and 4, a light reflecting material having a silicone resin and a metal oxide as constituent components has been proposed. However, these materials are unsuitable as white coating materials because, while having excellent durability, the composition itself does not have fluidity to bleed.

Japanese Patent Publication No. 2008-106226 Japanese Patent No. 4694 371 Japanese Patent Publication No. 2012-233035 Japanese Patent Publication No. 2013-221075

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an addition-curable silicone composition that provides a cured product having excellent light reflection performance even in a thin film as an addition-curable silicone composition having high fluidity.

In order to achieve the above object, in the present invention,

(A) a linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom per molecule and having a viscosity of 0.05 to 100 Pa·s at 25°C: 50 to 97 parts by mass,

(B) A three-dimensional network organopolysiloxane resin represented by the following average unit formula (1), which is waxy or solid at 23°C: 3 to 50 parts by mass (however, the sum of the component (A) and the component (B)) Is 100 parts by mass.),

(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO _3/2 ) _f (SiO ₂ ) _g (1)

(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group not containing an addition reactive carbon-carbon double bond, at least 80 mol% of all R ² is a methyl group, 1> a≥0, 1>b≥0, 1>c≥0, 1>d≥0, 1>e≥0, 1>f≥0 and 1>g≥0, and b+c+e>0, e +f+g>0, and a+b+c+d+e+f+g=1.)

(C) Organohydrogenpolysiloxane having hydrogen atoms bonded to at least two silicon atoms per molecule and not having addition reactive carbon-carbon double bonds: 1 mol of alkenyl groups in components (A) and (B) With respect to, the amount of hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 moles

(D) Hydrosilylation catalyst containing a platinum group metal: an amount of 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the component (A), the component (B) and the component (C),

(E) Titanium oxide powder subjected to siloxane treatment on the surface: 20 to 200 parts by mass, and

(F) a compound represented by the following formula (2): 0.1 to 10 parts by mass

(In the formula, R ³ is independently an alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.)

It provides an addition curable silicone composition containing.

This addition-curable silicone composition provides a cured product having high fluidity at room temperature and excellent in light reflection performance in a thin film.

In addition, the present invention provides a cured silicone cured product for a light reflecting material that is a cured product of the addition curable silicone composition.

This cured product is excellent in light reflection performance in a thin film.

This cured product preferably has a reflectance of 90% or more of light having a wavelength of 430 to 800 nm in a thickness of 0.3 mm or less.

The cured product having a reflectance of at least a predetermined value has better light reflection performance in a thin film.

The present invention provides a light reflecting material comprising the cured silicone for light reflecting material.

Even if this light reflecting material is thin, it is excellent in light reflection performance.

In addition, the present invention provides an optical semiconductor device having the light reflecting material.

This optical semiconductor device is capable of maintaining high light extraction efficiency over a long period of time.

Since the addition-curable silicone composition of the present invention has high fluidity at room temperature, it is excellent in workability and handleability, and can be spread and coated in a film form, for example, by applying it to a part on a horizontal plate. In addition, the cured silicone product obtained by thermally curing the composition is excellent in light reflection performance even in a thin film. Therefore, the cured product is useful as a light reflective material for optical semiconductors, particularly as a light reflective coating material.

1 is a cross-sectional view schematically showing an example of an optical semiconductor device in which the silicone cured product for a light reflecting material of the present invention is used.

As described above, as an addition-curable silicone composition having high fluidity, development of an addition-curable silicone composition that provides a cured product having excellent light reflection performance even in a thin film is required.

The present inventors, as a result of intensive research, found out that the above-described problem can be achieved and is suitable as a light reflecting material if it is an addition-curable silicone composition containing the following components (A) to (F), and the present invention is completed. Made it.

That is, the present invention

(A) a linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom per molecule and having a viscosity of 0.05 to 100 Pa·s at 25°C: 50 to 97 parts by mass,

(B) A three-dimensional network organopolysiloxane resin represented by the following average unit formula (1), which is waxy or solid at 23°C: 3 to 50 parts by mass (however, the sum of the component (A) and the component (B)) Is 100 parts by mass.),

(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO _3/2 ) _f (SiO ₂ ) _g (1)

(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group not containing an addition reactive carbon-carbon double bond, at least 80 mol% of all R ² is a methyl group, 1> a≥0, 1>b≥0, 1>c≥0, 1>d≥0, 1>e≥0, 1>f≥0 and 1>g≥0, and b+c+e>0, e +f+g>0, and a+b+c+d+e+f+g=1.)

(C) Organohydrogenpolysiloxane having hydrogen atoms bonded to at least two silicon atoms per molecule and not having addition reactive carbon-carbon double bonds: 1 mol of alkenyl groups in components (A) and (B) With respect to, the amount of hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 moles

(D) Hydrosilylation catalyst containing a platinum group metal: an amount of 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the component (A), the component (B) and the component (C),

(E) Titanium oxide powder subjected to siloxane treatment on the surface: 20 to 200 parts by mass, and

(F) a compound represented by the following formula (2): 0.1 to 10 parts by mass

(In the formula, R ³ is independently an alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.)

It is an addition curable silicone composition containing.

Hereinafter, although this invention is demonstrated in detail, this invention is not limited to these. In addition, in this specification, "Me" represents a methyl group, and "Vi" represents a vinyl group. The viscosity is a value at 25°C using a rotational viscometer.

<Addition curable silicone composition>

Hereinafter, each component will be described in detail.

[(A) component]

The component (A) is a component that serves as the main skeleton of the composition of the present invention, and is a linear organopolysiloxane having at least two alkenyl groups in one molecule.

The viscosity of the component (A) is 0.05 to 100 Pa·s, preferably 0.1 to 50 Pa·s, and more preferably 0.5 to 10 Pa·s. When the viscosity is less than 0.05 Pa·s, the strength of the cured product is weakened, and when the viscosity is 100 Pa·s or more, the fluidity decreases.

As the alkenyl group in the component (A), a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group are exemplified, and a vinyl group is particularly preferable. Alkenyl groups contained in one molecule are at least 2, preferably 2 to 20, more preferably 2 to 5. If it is less than two, the hardness of the hardened product becomes insufficient, and if it is less than 20, the hardened product does not become brittle.

The hydrocarbon group bonded to a silicon atom other than the alkenyl group in the component (A) is not particularly limited, and for example, an unsubstituted or substituted monovalent alkyl group having usually 1 to 12 carbon atoms, preferably 1 to 10 to be. Examples of the unsubstituted or substituted monovalent alkyl group include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, and heptyl group; Cycloalkyl groups, such as a cyclohexyl group; Aryl groups such as phenyl group, tolyl group, xylyl group, and naphthyl group; Aralkyl groups such as benzyl group and phenethyl group; A halogenated alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as a chlorine atom, a fluorine atom, and a bromine atom. Are mentioned, Preferably it is a methyl group.

Specific examples of the component (A) include organopolysiloxanes represented by the following formula.

ViMe ₂ SiO (SiMe ₂ O) _p SiMe ₂ Vi

ViMe ₂ SiO(SiMeViO) _q (SiMe ₂ O) _p SiMe ₂ Vi

Vi ₂ MeSiO (SiMe ₂ O) _p SiMeVi ₂

Vi ₃ SiO (SiMe ₂ O) _p SiVi ₃

Vi ₂ MeSiO(SiMeViO) _q (SiMe ₂ O) _p SiMeVi ₂

Vi ₃ SiO(SiMeViO) _q (SiMe ₂ O) _p SiVi ₃

Me ₃ SiO(SiMeViO) _r (SiMe ₂ O) _p SiMe ₃

(In the formula, p, q, and r are integers of p≥0, q≥0, and r≥2, and are integers that satisfy the viscosity range of the component (A).)

As a specific example of the linear organopolysiloxane of component (A), what is represented by the following formula, etc. are mentioned.

ViMe ₂ SiO (SiMe ₂ O) ₂₀₀ SiMe ₂ Vi

ViMe ₂ SiO (SiMe ₂ O) ₄₅₀ SiMe ₂ Vi

The component (A) may be used alone or in combination of two or more.

[(B) component]

The component (B) is a component for imparting strength to a cured product obtained by curing the present composition, and is a three-dimensional network organopolysiloxane resin represented by the following average unit formula (1).

(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO _3/2 ) _f (SiO ₂ ) _g (1)

(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group not containing an addition reactive carbon-carbon double bond, at least 80 mol% of all R ² is a methyl group, 1> a≥0, 1>b≥0, 1>c≥0, 1>d≥0, 1>e≥0, 1>f≥0 and 1>g≥0, and b+c+e>0, e +f+g>0, and a+b+c+d+e+f+g=1.)

In addition, the component (B) is a beeswax or solid at 23°C, and the term "beeswax" means 10,000 Pa·s or more, particularly 100,000 Pa·s or more, at 23° C. ).

In the above average composition formula (1), the alkenyl group represented by R ¹ is of the same type as that exemplified as the alkenyl group in the component (A), but a vinyl group is preferable from the viewpoint of availability and price.

The monovalent hydrocarbon group that does not contain an addition reactive carbon-carbon double bond represented by R ² may be those of the same type as exemplified as a hydrocarbon group bonded to a silicon atom other than an alkenyl group in the component (A). It is preferable that at least 80 mol% of R ² is a methyl group, and 95 to 100 mol% is a methyl group.

a is 0 to 0.65, b is 0 to 0.65, c is 0 to 0.5, d is 0 to 0.5, e is 0 to 0.8, f is 0 to 0.8, g is preferably a number of 0 to 0.6. Further, b+c+e is preferably a number of 0.01 to 0.30, particularly 0.05 to 0.20, and e+f+g is preferably a number of 0.1 to 0.8, particularly 0.2 to 0.6.

It is preferable that the organopolysiloxane resin of (B) component is represented by the following formula, for example.

(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (SiO ₂ ) _g

(R ¹ R ² ₂ SiO _1/2 ) _b (SiO ₂ ) _g

(R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f

(R ¹ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e

(R ¹ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f

(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f

(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f

(In the formula, R ¹ , R ² , a, b, c, d, e, f and g are as defined in the average unit formula (1).)

As a specific example of the component (B), what is represented by the following average unit formula, etc. are mentioned.

(Me ₃ SiO _1/2 ) _0.4 (ViMe ₂ SiO _1/2 ) _0.1 (SiO ₂ ) _0.5 ,

(ViMeSiO) _0.2 (Me ₂ SiO) _0.35 (MeSiO _3/2 ) _0.45 ,

(ViMe ₂ SiO _1/2 ) _0.2 (Me ₂ SiO) _0.25 (MeSiO _3/2 ) _0.55

The component (B) may be used alone or in combination of two or more.

The blending amount of the component (B) is 3 to 50 parts by mass, preferably 3 to 30 parts by mass, and more preferably 5 to 20 parts by mass based on 100 parts by mass of the total of the component (A) and the component (B). . When the blending amount of the component (B) is less than 3 parts by mass with respect to the total 100 parts by mass of the component (A) and the component (B), it becomes difficult to obtain fluidity. In addition, when the blending amount exceeds 50 parts by mass, the viscosity of the composition increases, thereby reducing the fluidity.

[Component (C)]

Component (C) is an organohydrogenpolysiloxane that has hydrogen atoms bonded to at least two silicon atoms per molecule (i.e., SiH group) and does not have an addition reactive carbon-carbon double bond, and component (A) And a hydrosilylation reaction with component (B) to act as a crosslinking agent.

The organohydrogenpolysiloxane of component (C) has, on average, at least 2, preferably 3 to 300, more preferably 4 to 150 SiH groups per molecule.

The bonding position of the silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane molecule of the component (C) may be a molecular chain terminal, a molecular chain non-terminal, or both.

In the component (C), the content of the silicon atom-bonded hydrogen atom is preferably 0.001 to 5 moles, and particularly preferably 0.01 to 2 moles, in 100 g of the component (C).

In the organohydrogenpolysiloxane molecule, the silicon atom-bonded hydrocarbon group other than the silicon atom-bonded hydrogen atom is not particularly limited, but, for example, unsubstituted or substituted, the number of carbon atoms is usually 1 to 10, preferably 1 to And a 6-membered monovalent alkyl group. As a specific example thereof, in the component (A), the same as those exemplified as silicon atom-bonded hydrocarbon groups other than the silicon atom-bonded alkenyl group can be mentioned.

The organohydrogenpolysiloxane molecular structure of the component (C) is not particularly limited, and examples thereof include a linear, cyclic, branched, and three-dimensional network structure (resin), and a linear or cyclic is preferable.

The viscosity at 25° C. in the component (C) is preferably 0.1 to 5,000 mPa·s, more preferably 0.5 to 1,000 mPa, in order to be more excellent in workability of the composition, optical properties, and mechanical properties of the cured product. ·S, particularly preferably a range of 2 to 500 mPa·s, which is in a liquid state at 23°C is preferable. When this viscosity is satisfied, the number of silicon atoms (or degree of polymerization) in one molecule of organohydrogenpolysiloxane is usually 2 to 1,000, preferably 3 to 300, and more preferably 4 to 150.

Specific examples of the organohydrogenpolysiloxane of component (C) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogencyclopolysiloxane, dimethylsiloxane/methyl Hydrogensiloxane cyclic copolymer, tris(dimethylhydrogensiloxy)methylsilane, tris(dimethylhydrogensiloxy)phenylsilane, blockade of trimethylsiloxy groups at both ends of the molecular chain, methylhydrogenpolysiloxane, blockade of trimethylsiloxy groups at both ends of the molecular chain Dimethylsiloxane/methylhydrogensiloxane copolymer, trimethylsiloxy group blocking at both ends of the molecular chain dimethylsiloxane/methylhydrogensiloxane/methylphenylsiloxane copolymer, blocking dimethylhydrogensiloxy groups at both ends of the molecular chain dimethylpolysiloxane, dimethylhydrogen at both ends of the molecular chain Gensiloxy group-blocked dimethylsiloxane/methylhydrogensiloxane copolymer, molecular chain both ends dimethylhydrogensiloxy group-blocked dimethylsiloxane-methylphenylsiloxane copolymer, molecular chain both ends dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane, formula: (CH ₃ ) ₂ A siloxane unit represented by HSiO _1/2 and the formula: (CH ₃ ) _{3 A} copolymer containing a siloxane unit represented by SiO _1/2 and a formula: SiO _4/2 , the formula: (CH ₃ ) A copolymer containing a siloxane unit represented by ₂ HSiO _1/2 and a siloxane unit represented by a formula: SiO _4/2 , and a mixture containing two or more of these organopolysiloxanes.

It is preferable that the organohydrogenpolysiloxane of component (C) is represented by the following formula, for example.

Me ₃ SiO (MeHSiO) _i SiMe ₃

Me ₃ SiO(MeHSiO) _i (Me ₂ SiO) _j SiMe ₃

(In the formula, i and j are integers of 2 to 100, preferably 2 to 50.)

As a specific example of the component (C), organohydrogen polysiloxane represented by the following formula is mentioned.

Me ₃ SiO (MeHSiO) ₃₈ SiMe ₃

The organohydrogenpolysiloxane of component (C) may be used singly or in combination of two or more.

The blending amount of the component (C) is 0.4 to 4.0 moles of hydrogen atoms bonded to the silicon atom per 1 mole of the alkenyl group in the component (A) and component (B) from the viewpoint of the strength, optical and mechanical properties of the cured product. It is an amount that becomes, preferably, it is an amount that becomes 0.6 to 3.0 mol.

[(D) component]

The platinum group metal hydrosilylation catalyst of the component (D) is not particularly limited as long as it promotes the hydrosilylation reaction of the alkenyl group in the component (A) and the component (B) and the SiH group in the component (C), and specific examples thereof , Platinum group metals such as platinum, palladium, and rhodium; Platinum-based compounds such as chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid and olefins, and coordination compounds of vinylsiloxane or acetylene compounds; And platinum group metal compounds such as tetrakis(triphenylphosphine)palladium, chlorotris(triphenylphosphine)rhodium, etc., but preferably a platinum-based compound, particularly preferably a coordination compound of chloroplatinic acid and vinylsiloxane. .

(D) component may be used individually by 1 type, or may use 2 or more types together.

The blending amount of the component (D) may be an effective amount as a hydrosilylation catalyst, and is in the range of 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the component (A), the component (B) and the component (C). It is preferably in the range of 1 to 500 ppm. When this range is satisfied, the reaction rate of the addition reaction becomes appropriate, and a cured product having high strength can be obtained.

[(E) component]

The component (E) is a titanium oxide powder that has been subjected to a siloxane treatment on the surface, and is a component that imparts light reflection performance to the present composition.

When the surface of the titanium oxide powder is not subjected to a siloxane treatment, bubbles are generated when the addition-curable silicone composition is cured by moisture contained in the powder, and sufficient performance as a light reflecting material cannot be exhibited. In order to prevent foaming, there is a method of performing heating and reduced pressure mixing in silicone, but passing through this step is not preferable because the fluidity is lowered.

The crystal form of titanium oxide is classified into anatase, rutile, and bruchite, but it is preferable to use a rutile type having the most stable heat transfer.

The particle diameter of the component (E) is not particularly limited, but in general, many products having an average particle diameter in the range of 0.1 to 200 µm are commercially available and are easy to handle, more preferably in the range of 0.1 to 100 µm. When the average particle diameter of the component (E) is in the range of 0.1 to 200 µm, the addition-curable silicone composition of the present invention tends to have good fluidity, and the surface of the resulting cured product is difficult to be rough, and the light reflection performance is effectively improved.

As such (E) component, a commercial item may be used, and as a specific example, Ishihara Sangyo Co., Ltd. Taipei PF-691, Taipei CR-63, etc. are mentioned.

The component (E) may be used alone or in combination of two or more.

The blending amount of the component (E) is 20 to 200 parts by mass based on 100 parts by mass in total of the component (A) and the component (B). It is preferably 30 to 150 parts by mass, more preferably 40 to 100 parts by mass. If the blending amount of the component (E) is less than 20 parts by mass relative to the total 100 parts by mass of the component (A) and the component (B), the cured product will have poor light reflection performance, and if it exceeds 200 parts by mass, fluidity becomes difficult to obtain .

[(F) component]

The component (F) is a component for imparting fluidity to the addition curing silicone composition of the present invention by coexisting with the component (B), and is a compound represented by the following formula (2).

(In the formula, R ³ is independently an alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, preferably 1. m is an integer of 1 to 10, preferably 2 to 9 And more preferably 3 to 8.)

R ³ in formula (2) is independently, for example, an alkoxy group having 1 to 6 carbon atoms. As this alkoxy group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, etc. are mentioned, Preferably it is a methoxy group and an ethoxy group. , More preferably, it is a methoxy group.

R ⁴ in formula (2) is an alkoxy group or an alkyl group, and examples of the alkoxy group include those similar to the alkoxy groups illustrated by R ³ . As the alkyl group, the same thing as exemplified in the component (A) is illustrated.

Specific examples of the component (F) include those shown below, but are not limited thereto.

The component (F) may be used alone or in combination of two or more.

The blending amount of the component (F) is an amount of 0.1 to 10 parts by mass, preferably 0.5 to 5.0 parts by mass, based on 100 parts by mass of the total of the component (A) and the component (B). If the blending amount of the component (F) is too small, the fluidity will decrease, and if the blending amount of the component (F) is too large, the durability of the resulting cured product will decrease.

<Other ingredients>

To the addition curable silicone composition of the present invention, components such as an organic peroxide, an antioxidant, an adhesion improving agent or a reaction inhibitor may be added depending on the purpose.

As the organic peroxide, for example, benzoyl peroxide, t-butyl perbenzoate, o-methylbenzoyl peroxide, p-methylbenzoyl peroxide, dicumyl peroxide, 1,1-bis(t-butylperoxy)- 3,3,3-trimethylcyclohexane, di(4-methylbenzoylperoxy)hexamethylene biscarbonate, etc. are mentioned.

The amount of the organic peroxide added is preferably 0.01 to 5 parts by mass, and particularly preferably 0.05 to 3 parts by mass, based on 100 parts by mass in total of the components (A) to (F). If it is such a range, further improvement of resin strength can be achieved. These can be used alone or in combination of two or more.

Examples of the antioxidant include hindered amines and hindered phenol compounds, and the amount of the added is preferably 500 to 3,000 ppm based on the total mass of the components (A) to (F).

As the adhesion improving agent, from the viewpoint of imparting self-adhesion to the composition of the present invention, which is an addition reaction curable type, an organosilicon compound such as a silane or siloxane containing a functional group that imparts adhesion, and a non-silicone organic compound are used.

Specific examples of the functional group imparting adhesiveness include alkenyl groups or hydrogen atoms such as vinyl groups and allyl groups bonded to silicon atoms; An epoxy group bonded to a silicon atom via a carbon atom (eg, γ-glycidoxypropyl group, β-(3,4-epoxycyclohexyl) ethyl group, etc.), acryloxy group (eg, γ-acryloxy Propyl group, etc.), or a methacryloxy group (eg, γ-methacryloxypropyl group, etc.); Alkoxysilyl group (e.g., trimethoxysilyl group, triethoxysilyl group, methyldimethoxysilyl group bonded to a silicon atom through an alkylene group that may contain 1 to 2 ester structures, urethane structures, and ether structures) Alkoxysilyl groups such as) may be mentioned.

Examples of the organosilicon compound containing a functional group imparting adhesiveness include a silane coupling agent, a siloxane having an alkoxysilyl group and an organic functional group, and a compound having an alkoxysilyl group introduced into an organic compound having a reactive organic group.

Moreover, as a non-silicone type organic compound, an organic acid allyl ester, an epoxy group ring opening catalyst, an organic titanium compound, an organic zirconium compound, an organic aluminum compound, etc. are mentioned, for example.

Examples of the reaction inhibitor include phosphorus-containing compounds such as triphenylphosphine; Nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine, and benzotriazole; Sulfur-containing compounds; Acetylene compounds; Hydroperoxy compounds; Maleic acid derivatives; 1-ethynylcyclohexanol, 3,5-dimethyl-1-hexin-3-ol, ethynylmethyldecylcarbinol, 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl Known compounds having a curing inhibiting effect on the hydrosilylation catalyst of the component (D), such as cyclotetrasiloxane, are exemplified.

Since the degree of the curing inhibitory effect of the reaction inhibitor differs depending on the chemical structure of the reaction inhibitor, the amount of the reaction inhibitor is preferably adjusted to an optimal amount for each reaction inhibitor to be used. Preferably, it is 0.001-5 mass parts with respect to the total 30 mass parts of (A) component, (B) component, and (C) component. When the blending amount is 0.001 parts by mass or more, long-term storage stability of the composition at room temperature can be sufficiently obtained. If the blending amount is 5 parts by mass or less, there is no fear of inhibiting curing of the composition.

In addition, in the addition-curable silicone composition of the present invention, in order to improve reinforcing properties, for example, fine powdered silica, crystalline silica, hollow fillers, inorganic fillers such as silsesquioxane, and these fillers are used as organoalkoxysilane compounds, Fillers subjected to surface hydrophobic treatment with organosilicon compounds such as organochlorosilane compounds, organosilazane compounds and low molecular weight siloxane compounds; Silicone rubber powder, silicone resin powder, or the like may be blended.

As the fine powder silica, the specific surface area (BET method) is preferably 50 m ² /g or more, more preferably 50 to 400 m ² /g, and particularly preferably 100 to 300 m ² /g. When the specific surface area is 50 m ² /g or more, sufficient reinforcing properties can be provided to the cured product.

As such fine-powdered silica, known ones conventionally used as reinforcing fillers for silicone rubber can be used, and examples thereof include aerosol silica (dry silica), precipitated silica (wet silica), and the like. Fine powdered silica may be used as it is, but in order to impart good fluidity to the composition, methylchlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane, and methyltrichlorosilane, dimethylpolysiloxane, hexamethyldisilazane, divinyltetramethyldi It is preferable to use one treated with an organosilicon compound such as hexaorganodisilazane such as silazane and dimethyltetravinyldisilazane. These reinforcing silicas may be used alone or in combination of two or more.

The addition-curable silicone composition of the present invention can be prepared by mixing components (A) to (F) and other components as necessary, but includes, for example, (A) component, (B) component and (D) component. After preparing the part to be described and the part containing the component (C) separately, the two parts may be mixed and used. Moreover, you may mix the part containing the component (A), the component (B), and the component (C), and the part containing the component (D).

In other words, since component (B) is waxy or solid at 23°C, in order to dissolve in other components, a solution obtained by dissolving component (B) in a solvent is mixed with component (A) and distilled under reduced pressure. By removing the solvent, after preparing a mixture of component (A) and component (B), you may mix with other components.

The addition-curable silicone composition of the present invention is liquid before curing and has high fluidity. The fluidity here means how much it flows on the slanted smooth plate, and since it does not necessarily correlate with the rotational viscosity, it is distinguished.

When 0.05 g of the addition-curable silicone composition of the present invention is placed on an aluminum plate having an inclination angle of 45° to the horizontal and allowed to stand at 25° C. for 1 hour, the length (flowability) is preferably 30 mm or more, and more preferably 40 mm or more. . When the flowability is 30 mm or more, the composition tends to spread the coated surface and the workability is good. In other words, the length here is the maximum linear distance from the end of the composition to the end.

[Silicone cured product for light reflecting material]

By curing the addition-curable silicone composition of the present invention, a white cured silicone for light reflecting materials can be obtained. Since the addition-curable silicone composition of the present invention has good fluidity, the light reflecting material can be thin-film coated by applying by dispensing and curing after self-leveling. In addition, the curing conditions of the addition-curable silicone composition of the present invention are not particularly limited, but it is usually 80 to 200°C, preferably 100 to 180°C for 1 minute to 24 hours, and 5 minutes to 5 hours. This is more preferable.

Since it is assumed that the addition curable silicone composition of the present invention is used by coating a thin film, the reflectance of the visible light (wavelength: 430 to 800 nm) of the thin film is required to be good. Specifically, it is preferable that the visible light reflectance at a thickness of 0.3 mm or less of the cured product is 90% or more (that is, 90 to 100%). More preferably, the visible light reflectance is 95% or more (that is, 95 to 100%). If the reflectance is 90% or more, when coated on a lead frame having a low light reflectance such as gold plating or aluminum, the light extraction efficiency becomes higher, and sufficient brightness for an optical semiconductor device can be easily secured. In addition, in the present specification, the reflectance of light means a numerical value measured by a spectrophotometer device equipped with an integrating sphere.

[Light reflective material]

The light reflecting material containing the silicone cured product for light reflecting materials of the present invention can be suitably used as, for example, a light reflecting coating material for optical semiconductor devices such as LEDs, and especially lead frames for white LEDs.

[Optical semiconductor device]

In addition, the present invention provides an optical semiconductor device having the light reflecting material.

As described above, the addition-curable silicone composition of the present invention provides a silicone cured product for a light reflecting material excellent in light reflection performance even in a thin film. Therefore, an optical semiconductor device such as a white LED using the light reflecting material of the present invention can maintain high light extraction efficiency over a long period of time.

An embodiment of the optical semiconductor device of the present invention will be described with reference to FIG. 1. As shown in Fig. 1, by dropping a white coating material 6 on the lead electrode 2 provided in the optical semiconductor device 7, it spreads to cover the lead electrode 2, etc., and after curing, the lead electrode (2) Instead, the light emitted from the light-emitting element 1 is reflected, and the light extraction efficiency can be improved. Further, the light emitting element 1 bonded on the lead electrode 2 with the die bonding material 3 is connected to the lead electrode 2 by a gold wire 4. Further, a reflector is formed on the periphery of the optical semiconductor device 7 by a light reflecting resin 5.

[Example]

Hereinafter, the present invention will be specifically described using Examples and Comparative Examples, but the present invention is not limited thereto. In the following, the viscosity is a value at 25°C measured using a rotational viscometer, and the weight average molecular weight is a value in terms of standard polystyrene in gel permeation chromatography (GPC). In addition, the symbol meaning of each siloxane unit is as follows.

M ^H : (CH ₃ ) ₂ HSiO _1/2

M: (CH ₃ ) ₃ HSiO _1/2

M ^Vi : (CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2

D ^H : (CH ₃ )HSiO _2/2

D: (CH ₃ ) ₂ SiO _2/2

Q: SiO _4/2

[Examples 1 to 3, Comparative Examples 1 to 6]

Each of the following components was mixed in the blending amount shown in Table 1 to prepare an addition curable silicone composition. In addition, the numerical value of each component in Table 1 represents a mass part. In addition, in Examples 1 to 3 and Comparative Examples 1 and 3 to 6, a solution obtained by dissolving component (B) in xylene is mixed with component (A), and xylene is removed by distillation under reduced pressure to remove component (A). After preparing a mixture of components (B) and (B), they were mixed with other components.

That is, first, a 5 liter gate mixer (manufactured by Inoue Seisakusho Co., Ltd., brand name: 5 liter planetary mixer) was used, and a mixture of the component (A) and the component (B) (in Comparative Example 2, (A) Component only) and (E) component are mixed at 25°C for 1 hour, then (D) component and (F) component are added and mixed at 25°C for 30 minutes, and then (G) component is added to 25°C The mixture was mixed for 30 minutes at, and finally, component (C) was added and mixed for 30 minutes in an environment of 25° C. and reduced pressure (30 mmHg) to obtain an addition-curable silicone composition.

For Comparative Example 6, a titanium oxide dehydration step was added in the same blending composition as Comparative Example 5. That is, first, using a 5-liter gate mixer, the mixture of components (A) and (B) and component (E) were mixed for 1 hour in an environment of 150°C and reduced pressure (30mmHg) to dehydrate titanium oxide, and then 25°C. After returning to, (D) component and (F) component were added and mixed for 30 minutes, and then (G) component was added and mixed for 30 minutes at 25°C, and finally (C) component was added and 25°C , By mixing for 30 minutes in a reduced pressure (30 mmHg) environment to obtain an addition-curable silicone composition.

(A) Ingredient:

(A-1) Average molecular formula: M ^Vi ₂ D ₂₀₀ (0.013 mol/100 g), a viscosity of 1.0 Pa s organopolysiloxane

(B) component:

(B-1) A solid organopolysiloxane resin at 23° C. having a weight average molecular weight of 5,300 and a vinyl group content of 1.0 mmol/g represented by the average unit formula M _0.40 M ^Vi _0.07 Q _0.53

(C) component:

(C-1) Average molecular formula: M ₂ D ^H ₃₈ (1.55 mol/100 g), a viscosity of 20 mPa s organohydrogenpolysiloxane

(D) component:

(D-1) a toluene solution of a platinum complex having 1,3-divinyltetramethyldisiloxane derived from chloroplatinic acid as a ligand (containing 1% by mass of platinum atoms),

(E) component:

(E-1) Titanium oxide powder, Ishihara Sangyo Co., Ltd. Taipei PF-691 (siloxane treatment, average particle diameter 0.21 µm)

(E-2) Titanium oxide powder, Ishihara Sangyo Co., Ltd. Taipei CR-63 (siloxane treatment, average particle diameter 0.21 µm)

Comparative ingredients:

(E-3) Titanium oxide powder, Ishihara Sangyo Co., Ltd. Taipei R-820 (Al, Si, Zr treatment, average particle diameter 0.26 µm)

(E-4) Titanium oxide powder, Ishihara Sangyo Co., Ltd. Taipei CR-60 (Al treatment, average particle diameter 0.21 µm)

(F) Ingredient:

(F-1) a compound represented by the following formula (3)

(F-2) a compound represented by the following formula (4)

Comparative ingredients:

(F-3) a compound represented by the following formula (5)

(G) component: addition reaction control agent

(G-1) 1-ethynylcyclohexanol

The following evaluation was performed on the addition-curable silicone compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 6, and the results are shown in Table 2.

[Flow of composition]

0.05 g of each composition was weighed on an aluminum plate, and the length of the composition was measured after 1 hour at an angle of 45° with respect to the horizontal in an environment of 25°C. In addition, the length here is the linear maximum distance from the end of the composition to the end. When it flows until it becomes a length of 30 mm or more, it shows that the composition has good fluidity.

Further, each composition was introduced into a mold and cured in an oven at 150° C. for 2 hours to obtain a cured product having a thickness of 0.3 mm. The following evaluation was performed on the obtained cured product, and the results are shown in Table 2.

[Exterior]

The surface of the cured product was observed using a microscope, and evaluated according to the following criteria.

Uniform appearance (GOOD), foaming (NG)

[Light reflectance]

The light reflectance of the cured product at wavelengths of 430 nm, 600 nm and 800 nm was measured at 25°C using a spectrophotometer U-3310 manufactured by Hitachi Co., Ltd. equipped with an integrating sphere.

As shown in Table 2, the addition-curable silicone compositions of Examples 1 to 3 have high fluidity at 25°C, no foaming at the time of curing, and have excellent light reflectance of the cured product. Therefore, the cured product of the addition-curable silicone composition of the present invention is useful as a light reflecting material, particularly as a coating material for reflector materials for optical semiconductor devices.

On the other hand, in Comparative Examples 1 and 3 in which the component (F) of the present invention was not used, and in Comparative Example 2 in which the component (B) of the present invention was not used, the flowability of the composition was insufficient, and the component (E) of the present invention Instead, in Comparative Examples 4 and 5 in which the titanium oxide powder was not subjected to the siloxane treatment on the surface, air bubbles were generated in the cured product. In addition, in Comparative Example 6 in which the titanium oxide dehydration step was added to the same blending composition as Comparative Example 5, the flowability of the composition was significantly impaired.

In addition, this invention is not limited to the said embodiment. The above-described embodiment is an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operation and effect is included in the technical scope of the present invention.

One… Light-emitting element, 2... Lead electrode, 3... Die Bonding Materials,
4… Geumsun, 5… Light reflective resin, 6... White coating material,
7... Optical semiconductor device.

Claims (5)

(A) a linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom per molecule and having a viscosity of 0.05 to 100 Pa·s at 25°C: 50 to 97 parts by mass,
(B) A three-dimensional network organopolysiloxane resin represented by the following average unit formula (1), which is waxy or solid at 23°C: 3 to 50 parts by mass (however, the sum of the component (A) and the component (B)) Is 100 parts by mass.),
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO _3/2 ) _f (SiO ₂ ) _g (1)
(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group not containing an addition reactive carbon-carbon double bond, at least 80 mol% of all R ² is a methyl group, 1> a≥0, 1>b≥0, 1>c≥0, 1>d≥0, 1>e≥0, 1>f≥0 and 1>g≥0, and b+c+e>0, e +f+g>0, and a+b+c+d+e+f+g=1.)
(C) Organohydrogenpolysiloxane having hydrogen atoms bonded to at least two silicon atoms per molecule and not having addition reactive carbon-carbon double bonds: 1 mole of alkenyl groups in components (A) and (B) With respect to, the amount of hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 moles
(D) Hydrosilylation catalyst containing a platinum group metal: An amount of 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the component (A), the component (B) and the component (C),
(E) Titanium oxide powder subjected to siloxane treatment on the surface: 20 to 200 parts by mass, and
(F) a compound represented by the following formula (2): 0.1 to 10 parts by mass

(In the formula, R ³ is independently an alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.)
Addition-curable silicone composition comprising a. A silicone cured product for a light reflecting material, which is a cured product of the addition curable silicone composition according to claim 1. The silicone cured product for a light reflecting material according to claim 2, wherein the reflectance of light having a wavelength of 430 to 800 nm in a thickness of 0.3 mm or less is 90% or more. A light reflective material comprising the silicone cured product for light reflecting materials according to claim 2 or 3. An optical semiconductor device comprising the light reflecting material according to claim 4.

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