JP6850271B2 - Thermosetting silicone compositions, silicone resin cured products, and semiconductor devices - Google Patents

Description

The present invention comprises a transparent thermosetting silicone composition that provides a silicone resin cured product useful as a sealing material for an optical element, particularly a white LED (light emitting diode), a cured product of the composition, and the cured product. The present invention relates to a semiconductor device in which an optical element is sealed.

The thermosetting silicone composition contains an organopolysiloxane containing an addition-reactive carbon-carbon double bond and an organosilicon compound having a hydrogen atom bonded to silicon, and is cured by a hydrosilylation reaction to give a cured product. The cured product thus obtained has excellent heat resistance, cold resistance, and electrical insulation, and is transparent, so that it is used in various optical applications such as LED encapsulants (Patent Documents 1 and 2). ).

However, since the optical element encapsulant made of such a composition generally has a low gas barrier property, there is a drawback that the silver electrode is discolored due to the intrusion of corrosive gas from the outside. As a result, the brightness of the LED may decrease.

Therefore, an optical element encapsulant using a thermosetting silicone composition containing a polycyclic hydrocarbon skeleton-containing component has been proposed. Since the encapsulant obtained from such a composition has a high gas barrier property, it is possible to prevent the invasion of corrosive gas from the outside and suppress the discoloration of the silver electrode. However, since it has a drawback of being easily discolored by heat, there is a problem that it cannot be used particularly for high-power LEDs (Patent Documents 3 and 4).

Further, an optical element encapsulant using a thermosetting silicone composition in which a phenyl group is introduced into a main skeleton has been proposed. The encapsulant obtained from such a composition is superior in heat-resistant discoloration as compared with the polycyclic hydrocarbon skeleton-containing encapsulant described in Patent Documents 3 and 4, but silver due to an external corrosive gas. It is not sufficiently satisfactory in terms of suppressing corrosion of electrodes (Patent Document 5).

Japanese Unexamined Patent Publication No. 2004-186168 Japanese Unexamined Patent Publication No. 2004-143361 Japanese Unexamined Patent Publication No. 2008-069210 Japanese Unexamined Patent Publication No. 2012-046604 Japanese Unexamined Patent Publication No. 2010-132795

The present invention has been made in view of the above circumstances, and a cured product having high fluidity at room temperature, excellent transparency, heat resistance (thermal stability), particularly heat-resistant discoloration, and further high gas barrier property. Provided is a thermosetting silicone composition to be given. That is, the present invention provides a transparent thermosetting silicone composition that provides a cured silicone resin useful as a material for encapsulating an optical element, and a semiconductor device that is sealed by the cured product of the composition. The purpose.

（式中Ａは下記一般式（２）で表される基から成る群から選ばれる２価の基であり、Ｒ^１は、独立に非置換若しくは置換の炭素原子数１〜１２の１価炭化水素基、又は炭素原子数１〜６のアルコキシ基である。）

（式中Ｐｈはフェニル基であり、Ｒ^２は独立に非置換若しくは置換の炭素原子数１〜１２の１価炭化水素基であり、Ｒ^３は付加反応性炭素−炭素二重結合含有基であり、ｎは１〜２０の整数である。） In order to achieve the above problems, the present invention
(A-1) (a) A compound having two hydrogen atoms bonded to a silicon atom represented by the following general formula (1) in one molecule, and (b) one addition-reactive carbon-carbon double bond. An addition reaction product with two polycyclic hydrocarbons in a molecule, 30 to 70 parts by mass of an addition reaction product having at least two addition-reactive carbon-carbon double bonds in one molecule.
(A-2) 30 to 70 parts by mass of the compound represented by the following general formula (3) (however, the total of the (A-1) component and the (A-2) component is 100 parts by mass).
(B) An organosilicon compound having three or more hydrogen atoms bonded to silicon atoms in one molecule (the total amount of hydrogen atoms bonded to silicon atoms in the composition is an addition-reactive carbon-carbon dicarbonate in the composition. (C) A thermocurable silicone composition containing a hydrosilylation reaction catalyst (which is an amount of 0.5 to 3.0 in terms of molar ratio with respect to the heavy bond) is provided.

(A in the formula is a divalent group selected from the group consisting of the groups represented by the following general formula (2), and R ¹ is an independently unsubstituted or substituted monovalent hydrocarbon having 1 to 12 carbon atoms. It is a hydrogen group or an alkoxy group having 1 to 6 carbon atoms.)

(Ph in the formula is a phenyl group, R ² is an independently unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ³ is an addition-reactive carbon-carbon double bond-containing group. Yes, n is an integer from 1 to 20.)

Such a thermosetting silicone composition has high fluidity at room temperature, is excellent in transparency and heat resistance (heat stability), particularly heat-resistant discoloration, and has a further high gas barrier property. It becomes a transparent thermosetting silicone composition to be given.

（式中、Ｒ^４は非置換又は置換の炭素原子数２〜１２のアルケニル基である。） Further, it is preferable that the above (b) is represented by the following general formula (4).

(Wherein, ^{R 4} is unsubstituted or substituted alkenyl group having 2 to 12 carbon atoms.)

Further, (b) is any of 5-vinylbicyclo [2.2.1] hept-2-ene, 6-vinylbicyclo [2.2.1] hept-2-ene, and combinations thereof. Is preferable.

With such a raw material (b), higher gas barrier properties can be imparted.

（式中、Ｒ^５は独立に水素原子又はアルケニル基以外の非置換若しくは置換の炭素原子数
１〜１２の一価炭化水素基であり、Ｒ^６はメチル基あるいは水素原子であり、ｐは１〜１０の整数、ｑは０〜７の整数である。ｐが付されたシロキサン単位とｑが付されたシロキサン単位とは互いにランダムに配列している。） Further, it is preferable that the component (B) is a siloxane compound represented by the following general formula (5).

(In the formula, R ⁵ is an independently unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms other than a hydrogen atom or an alkenyl group, R ⁶ is a methyl group or a hydrogen atom, and p is 1. An integer of 10 and q are integers of 0 to 7. The siloxane unit with p and the siloxane unit with q are randomly arranged with each other.)

With such a component (B), when it is made into a cured product, it is possible to impart sufficient mechanical properties as an optical element encapsulating material.

Further, the present invention provides a cured silicone resin obtained by curing the above thermosetting silicone composition.

Such a cured silicone resin can be suitably used as a material for encapsulating an optical element.

At this time, the transmittance of light having a wavelength of 400 nm immediately after curing is 80% or more, and the transmittance of light having a wavelength of 400 nm after exposure for 500 hours in an environment of 150 ° C. is maintained at 70% or more. Is preferable.

When such a cured silicone resin is used as an optical element encapsulating material for a light emitting device such as a lighting fixture, the light extraction efficiency becomes higher and sufficient brightness can be easily ensured.

At this time, it is preferable that the cured product having a gas barrier property and having a thickness of 1 mm has a water vapor transmittance of 7 g / m ² · day or less at 40 ° C.

With such a cured silicone resin, there is no possibility that the silver electrode will be discolored due to the intrusion of corrosive gas from the outside, and the cured product was used as an optical element encapsulating material for light emitting devices such as lighting equipment. In that case, there is no possibility that the light extraction efficiency will be lowered and sufficient brightness cannot be secured.

Further, the present invention provides a semiconductor device in which an optical element is sealed with the above-mentioned cured silicone resin product.

In this case, it is preferable that the optical element is an LED (light emitting diode).

Such a semiconductor device will be more reliable.

Since the thermosetting silicone composition of the present invention has high fluidity at room temperature, it is excellent in workability and handleability. Further, the cured silicone resin obtained by heat-curing the above composition is excellent in transparency and heat resistance (heat stability), particularly heat-resistant discoloration, and further has high gas barrier property. Therefore, since the cured product is useful as an optical element encapsulating material, for example, an encapsulating material for a light emitting device, particularly for a white LED, it is possible to provide a highly reliable semiconductor device.

As described above, a thermosetting silicone composition having high fluidity at room temperature, excellent in transparency, heat resistance (thermal stability), particularly heat-resistant discoloration, and giving a cured product having high gas barrier properties. Development was required.

As a result of diligent studies on the above-mentioned problems, the present inventors have made a thermosetting silicone composition containing a reaction addition product by a hydrosilylation reaction having a specific structure and an organopolysiloxane having a specific structure. For example, it has high fluidity at room temperature, is excellent in transparency, heat resistance (thermal stability), particularly heat-resistant discoloration, and gives a cured product having higher gas barrier properties, and such a cured product is an optical element. We have found that it is useful as a sealing material and completed the present invention.

That is, the present invention
(A-1) (a) A compound having two hydrogen atoms bonded to a silicon atom represented by the above general formula (1) in one molecule, and (b) one addition-reactive carbon-carbon double bond. An addition reaction product with two polycyclic hydrocarbons in a molecule, 30 to 70 parts by mass of an addition reaction product having at least two addition-reactive carbon-carbon double bonds in one molecule.
(A-2) 30 to 70 parts by mass of the compound represented by the general formula (3) (however, the total of the (A-1) component and the (A-2) component is 100 parts by mass).
(B) An organosilicon compound having three or more hydrogen atoms bonded to silicon atoms in one molecule (the total amount of hydrogen atoms bonded to silicon atoms in the composition is an addition-reactive carbon-carbon dicarbonate in the composition. The thermocurable silicone composition is characterized by containing (C) a hydrosilylation reaction catalyst (which is an amount of 0.5 to 3.0 in terms of molar ratio with respect to a heavy bond).

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto. In this specification, Me and Ph represent a methyl group and a phenyl group, respectively, and the viscosity is a value measured by a rotational viscometer.

[(A-1) component]
The component (A-1) of the thermosetting silicone composition of the present invention is a component that imparts strength to the cured product after curing to increase its hardness and also imparts gas barrier properties.

（式中、Ａは、下記一般式（２）で表される基から成る群から選ばれる２価の基であり、Ｒ^１は、独立に非置換若しくは置換の炭素原子数１〜１２の１価炭化水素基、又は炭素原子数１〜６のアルコキシ基である。）

The components (A-1) are (a) a compound having two hydrogen atoms bonded to a silicon atom represented by the following general formula (1) in one molecule, and (b) an addition-reactive carbon-carbon double. It is an addition reaction product with a polycyclic hydrocarbon having two bonds in one molecule, and is an addition reaction product having at least two addition-reactive carbon-carbon double bonds in one molecule. Hereinafter, the raw material (a) and the raw material (b), which are the raw materials of the component (A-1), will be described.

(In the formula, A is a divalent group selected from the group consisting of the groups represented by the following general formula (2), and R ¹ is 1 of 1 to 12 independently unsubstituted or substituted carbon atoms. It is a valent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms.)

（Ｒ^１は独立に非置換もしくは置換の炭素原子数１〜１２の、好ましくは１〜６の、１価炭化水素基又は炭素原子数１〜６のアルコキシ基である） <Raw material (a)>
Two hydrogen atoms (hereinafter, sometimes referred to as "SiH") bonded to a silicon atom represented by the above general formula (1), which is a reaction raw material of the component (A-1), are contained in one molecule. The compound (raw material (a)) is a compound represented by the following general formula (6) because A in the above general formula (1) is a divalent group represented by the above general formula (2). is there.

(R ¹ is an independently unsubstituted or substituted alkoxy group having 1 to 12 carbon atoms, preferably 1 to 6 monovalent hydrocarbon groups or 1 to 6 carbon atoms).

In the above general formula (6), when R ¹ is a monovalent hydrocarbon group, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a pentyl group, an isopentyl group, etc. Alkyl group such as hexyl group, sec-hexyl group; cycloalkyl group such as cyclopentyl group and cyclohexyl group; aryl group such as phenyl group, o-, m-, p-tolyl; benzyl group, 2-phenylethyl group and the like Aralkyl group; alkenyl group such as vinyl group, allyl group, 1-butenyl group, 1-hexenyl group; alkenylaryl group such as p-vinylphenyl group; and one or more hydrogen bonded to carbon atom in these groups Alkyl halide groups in which the atoms are substituted with halogen atoms, cyano groups, epoxy ring-containing groups, etc., such as chloromethyl groups, 3-chloropropyl groups, 3,3,3-trifluoropropyl groups; 2- A cyanoethyl group; a 3-glycidoxypropyl group and the like can be mentioned.

Examples of the case where R ¹ is an alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group and the like.

Among them, the R ^1, is preferably a non-alkenyl and alkenyl aryl group, in particular, those all of R ¹ in one molecule is a methyl group, it is easy to produce industrially, It is preferable because it is easily available.

Examples of the compound represented by the above general formula (6) include, for example.
Structural formula: HMe ₂ Si-p-C ₆ H ₄ -Si-SiMe ₂ H
1,4-Bis (dimethylsilyl) benzene, represented by
Structural formula: HMe ₂ Si-m-C ₆ H ₄ -Si-SiMe ₂ H
1,3-bis (dimethylsilyl) benzene represented by
Structural formula: HMe ₂ Si-o-C ₆ H _4- SiMe ₂ H
Examples thereof include silphenylene compounds such as 1,2-bis (dimethylsilyl) benzene represented by.

The compound represented by the general formula (6) (the raw material (a) which is the reaction raw material of the component (A-1)) can be used alone or in combination of two or more. ..

<Raw material (b)>
In the polycyclic hydrocarbon (raw material (b)) having two addition-reactive carbon-carbon double bonds in one molecule, which is the reaction raw material of the component (A-1), "addition-reactive" is used. Means the property of being able to undergo the addition of a hydrogen atom bonded to a silicon atom (known as a hydrosilylation reaction).

Further, in the raw material (b), an addition-reactive carbon-carbon double bond is formed between two adjacent carbon atoms among the carbon atoms forming the polycyclic skeleton of (i) polycyclic hydrocarbon. , (Ii) The hydrogen atom bonded to the carbon atom forming the polycyclic skeleton of the polycyclic hydrocarbon is replaced by an addition-reactive carbon-carbon double bond-containing group, or (Iii) Among the carbon atoms forming the polycyclic skeleton of a polycyclic hydrocarbon, an addition-reactive carbon-carbon double bond is formed between two adjacent carbon atoms, and the polycyclic type. It does not matter if the hydrogen atom bonded to the carbon atom forming the polycyclic skeleton of the hydrocarbon is substituted with an addition-reactive carbon-carbon double bond-containing group. Here, as the addition-reactive carbon-carbon double bond-containing group, for example, an alkenyl group such as a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, or a norbornyl group, particularly one having 2 to 12 carbon atoms. And so on.

（式中、Ｒ^４は非置換又は置換の炭素原子数２〜１２のアルケニル基である。）

Examples of the raw material (b) include an alkenylnorbornene compound represented by the following general formula (4). Further, specific examples of the compound represented by the following general formula (4) include 5-vinylbicyclo [2.2.1] hept-2-ene represented by the following structural formula (7) and the following structural formula ( Examples thereof include 6-vinylbicyclo [2.2.1] hept-2-ene represented by 8) and a combination thereof. (Hereinafter, when it is not necessary to distinguish between these three, they may be collectively referred to as "vinyl norbornene").

(Wherein, ^{R 4} is unsubstituted or substituted alkenyl group having 2 to 12 carbon atoms.)

The vinyl group substitution position of the vinyl norbornene may be either a cis configuration (exo type) or a trans configuration (end type), and the reaction of the raw material (b) may be caused by such a difference in the arrangement. Since there is no particular difference in sex, etc., a combination of isomers of these two configurations may be used.

<Preparation of (A-1) component>
The component (A-1) of the thermosetting silicone composition of the present invention has one addition-reactive carbon-carbon double bond with respect to 1 mol of the raw material (a) having two SiHs in one molecule. Addition reaction by adding an excess amount of more than 1 mol and 10 mol or less, preferably more than 1 mol and 5 mol or less of the raw material (b) having two in the molecule in the presence of a hydrosilylation reaction catalyst. It can be obtained as an addition reaction product having at least two sex carbon-carbon double bonds in one molecule and not having SiH.

The component (A-1) thus obtained is derived from the raw material (a) in addition to the addition-reactive carbon-carbon double bond derived from the raw material (b) (specifically, in the general formula (1). since may include carbon double bonds, addition reactive carbon - - derived) addition reactive carbon R ¹ includes at least two carbon double bonds in one molecule, this number is preferably 2 to 6, More preferably, it is two. When the number of addition-reactive carbon-carbon double bonds is such a number, the cured product obtained by curing the thermosetting silicone composition of the present invention does not become brittle.

As the hydrosilylation reaction catalyst, all conventionally known catalysts can be used. For example, carbon powder carrying platinum metal, platinum black, secondary platinum chloride, platinum chloride acid, reaction product of platinum chloride acid and monovalent alcohol, complex of platinum and vinyl siloxane such as divinyltetramethyldisiloxane; Examples include a complex of chloroplatinic acid and olefins, a platinum-based catalyst such as platinum bisacetoacetate; and a platinum group metal-based catalyst such as a palladium-based catalyst and a rhodium-based catalyst. The addition reaction conditions, the use of the solvent, and the like are not particularly limited and may be as usual.

As described above, since the raw material (b) having an excess molar amount with respect to the raw material (a) is used for the preparation of the component (A-1), the component (A-1) is the raw material (b). It has two addition-reactive carbon-carbon double bonds derived from the structure in one molecule. Further, the component (A-1) has a residue derived from the raw material (a), and the residue is derived from the structure of the raw material (b) but has an addition-reactive carbon-carbon double bond. It may contain a structure linked by a divalent residue of a polycyclic hydrocarbon that does not have.

（式中、Ｘは上記原料（ａ）の化合物の二価の残基であり、Ｙは上記原料（ｂ）の多環式炭化水素の一価の残基であり、Ｙ´は上記原料（ｂ）の二価の残基であり、ｍは０〜１０、好ましくは０〜５の整数である） That is, as the component (A-1), for example, a compound represented by the following general formula (9) can be mentioned.

(In the formula, X is a divalent residue of the compound of the raw material (a), Y is a monovalent residue of the polycyclic hydrocarbon of the raw material (b), and Y'is the raw material (Y'). b) is a divalent residue, m is an integer of 0-10, preferably 0-5)

Regarding the value of m, which is the number of repeating units represented by (Y'-X), the excess molar amount of the raw material (b) to be reacted with 1 mol of the raw material (a) should be adjusted. It is possible to set by.

Specifically, as Y in the above general formula (9), for example, a monovalent residue represented by the following structural formula (hereinafter, when it is not necessary to distinguish between these six, these are referred to as “NB”. It is generically called "group", and it may be abbreviated as "NB" without distinguishing the structures of these six parties.)

Specific examples of Y'in the general formula (9) include divalent residues represented by the following structural formula.

However, the asymmetrical divalent residue represented by the above structural formula is not limited in the left-right direction as described above, and the above structural formula substantially describes each of the above structures on paper. The structure rotated by 180 degrees is also shown.

Suitable specific examples of the component (A-1) represented by the general formula (9) are shown below, but the present invention is not limited thereto. (Note that the meaning of "NB" is as described above.)

（式中、ｒは０〜１０の整数である。）

(In the formula, r is an integer from 0 to 10.)

Further, the component (A-1) of the present invention can be used alone or in combination of two or more.

[(A-2) component]
The component (A-2) is highly compatible with the component (A-1) and imparts heat resistance (thermal stability), particularly heat discoloration, without reducing the strength of the cured product after curing. Is.

The component (A-2) is a linear organocontainer in which the main chain consists of repeating diphenylsiloxane units and both ends of the molecular chain are sealed with a triorganosyloxy group having an addition-reactive carbon-carbon double bond-containing group. It is a polysiloxane. The organopolysiloxane of the component (A-2) may be used alone or in combination of two or more having different molecular weights, types of organic groups bonded to silicon atoms, and the like.

Addition reactive carbon as R ³ in the general formula (3) - carbon double bond-containing groups, the same as described in the description of <material (b)>, the addition of hydrogen atoms bonded to silicon atoms It is a group containing a carbon-carbon double bond having the property of undergoing (well known as a hydrosilylation reaction).

The addition-reactive carbon-carbon double bond-containing group may be used alone or in combination of two or more.

Specific examples of the addition-reactive carbon-carbon double bond-containing group include alkenyl having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, such as a vinyl group, an allyl group, a 5-hexenyl group, a propenyl group, and a butenyl group. Group; Alkadienyl group having 4 to 10 carbon atoms such as 1,3-butadienyl group; Acryloyloxy group (-O (O) CCH = CH ₂ ), Methacryloyloxy group (-O (O) CC (CH ₃ ) = The combination of the alkenyl group and the carbonyloxy group such as CH ₂ ); the combination of the alkenyl group and the carbonylamino group such as the acrylamide group (-NH (O) CCH = CH ₂ ) can be mentioned.

Among them, the vinyl group is used as the addition-reactive carbon-carbon double bond-containing group from the viewpoints of productivity and cost when obtaining the raw material of the component (A-2) and the reactivity of the component (A-2). , Allyl group and 5-hexenyl group are preferable, and vinyl group is particularly preferable.

^{R 2} in the above general formula (3) is an independently unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and the like. Alkyl group such as tert-butyl group, pentyl group, isopentyl group, hexyl group, sec-hexyl group; cycloalkyl group such as cyclopentyl group and cyclohexyl group; aryl group such as phenyl group, o-, m-, p-tolyl Aralkyl groups such as benzyl group and 2-phenylethyl group; alkenyl groups such as vinyl group, allyl group, 1-butenyl group and 1-hexenyl group; alkenylaryl groups such as p-vinylphenyl group; and among these groups One or more hydrogen atoms bonded to the carbon atom of the above are substituted with a halogen atom, a cyano group, an epoxy ring-containing group, etc., for example, a chloromethyl group, a 3-chloropropyl group, 3,3,3-trifluoro. Examples thereof include an alkyl halide group such as a propyl group; a 2-cyanoethyl group; a 3-glycidoxypropyl group and the like.

Among them, the R ^2, is especially a methyl group or a phenyl group, it is easy to produce industrially preferable since it is easily available.

In the component (A-2), the degree of polymerization n of the diphenylsiloxane unit is 1 to 20, preferably 1 to 15, and more preferably 2 to 10. When n is larger than 20, the fluidity is lowered and the compatibility with the component (A-1) is lowered, which is not preferable.

The blending amount of the component (A-2) is 30 to 70 parts by mass, preferably 35 to 65 parts by mass, more preferably 35 parts by mass, based on 100 parts by mass of the total of the components (A-1) and (A-2). Is 40 to 60 parts by mass. When the blending amount of the component (A-2) is less than 30 parts by mass, the heat-resistant discoloration property is lowered, and when it exceeds 70 parts by mass, the gas barrier property is lowered.

The component (A-2) contains an addition-reactive carbon-carbon double bond after hydrolysis / condensation of a bifunctional silane such as dichlorodiphenylsilane or dialkoxydiphenylsilane, or at the same time as hydrolysis / condensation. It can be obtained by sealing the ends with a group-bearing end-capping agent.

[(B) component]
The component (B) of the thermosetting silicone composition of the present invention is an organosilicon compound having three or more SiHs in one molecule. SiH in the component (B) is added by an addition-reactive carbon-carbon double bond having at least two components (A-1) and (A-2) in one molecule and a hydrosilylation reaction. A cured product having a three-dimensional network structure is given.

（式中、Ｒ^５は独立に水素原子又はアルケニル基以外の非置換若しくは置換の炭素原子数１〜１２の一価炭化水素基であり、Ｒ^６はメチル基あるいは水素原子であり、ｐは１〜１０の整数、ｑは０〜７の整数である。ｐが付されたシロキサン単位とｑが付されたシロキサン単位とは互いにランダムに配列している。） Examples of such a component (B) include a siloxane compound represented by the following general formula (5).

(In the formula, R ⁵ is an independently unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms other than a hydrogen atom or an alkenyl group, R ⁶ is a methyl group or a hydrogen atom, and p is 1. An integer of 10 and q are integers of 0 to 7. The siloxane unit with p and the siloxane unit with q are randomly arranged with each other.)

The ^{R 5} in the general formula (5), for example, methyl, ethyl, propyl, isopropyl, butyl, tert- butyl group, a pentyl group, an isopentyl group, a hexyl group, an alkyl such as sec- hexyl Group: Cycloalkyl group such as cyclopentyl group and cyclohexyl group; aryl group such as phenyl group, o-, m-, p-tolyl; aralkyl group such as benzyl group and 2-phenylethyl group; p-vinylphenyl group and the like Alkenylaryl groups; and one or more hydrogen atoms bonded to carbon atoms in these groups are substituted with halogen atoms, cyano groups, epoxy ring-containing groups, etc., for example, chloromethyl group, 3-chloropropyl group. , 3,3,3-Trifluoropropyl group and other alkyl halide groups; 2-cyanoethyl group; 3-glycidoxypropyl group and the like.

Among them, the R ^5, is especially a methyl group or a phenyl group, it is easy to produce industrially preferable since it is easily available.

Suitable specific examples of the above component (B) are shown below, but the present invention is not limited thereto.

HMe ₂ SiO (HMeSiO) ₂ (Ph ₂ SiO) ₂ SiMe ₂ H
HMe ₂ SiO (HMeSiO) ₂ (Ph ₂ SiO) ₂ (Me ₂ SiO) ₂ SiMe ₂ H
HMe ₂ SiO (HMeSiO) ₁ (Ph ₂ SiO) ₁ (Me ₂ SiO) ₄ SiMe ₂ H
HMe ₂ SiO (HMeSiO) ₃ (Me ₂ SiO) ₅ SiMe ₂ H
Me ₃ SiO (HMeSiO) ₆ (Ph ₂ SiO) ₂ SiMe ₃

The component (B) of the thermosetting silicone composition of the present invention can be used alone or in combination of two or more.

The blending amount of the component (B) is preferably set as follows. The thermosetting silicone composition of the present invention has a component having SiH other than the component (B) (for example, the component (G) described later) and a silicon atom other than the component (A-1) or (A-2). Either one of the components having an addition-reactive carbon-carbon double bond bonded to (for example, vinylsiloxane that can be contained in the present composition in the state of forming a complex with platinum as the component (C) described later) or Both can be contained. Therefore, the amount of the hydrogen atom bonded to the silicon atom in the present composition is preferably 0.5 to 3 with respect to 1 mol of the addition-reactive carbon-carbon double bond bonded to the silicon atom in the present composition. It is 0 mol, more preferably 0.8 to 2.0 mol. When the blending amount of the component (B) is an amount satisfying such a condition, a cured product having sufficient mechanical properties when used as a material for encapsulating an optical element can be obtained from the thermosetting silicone composition of the present invention. be able to.

When only the components (A-1) and (A-2) have an addition-reactive carbon-carbon double bond bonded to a silicon atom, and only the component (B) has SiH, the present invention The amount of the component (B) to be blended in the thermosetting silicone composition is preferably SiH in the component (B) with respect to 1 mol of the addition-reactive carbon-carbon double bond in the component (A). The amount is preferably 0.5 to 3.0 mol, more preferably 0.8 to 2.0 mol.

[Component (C)]
As the hydrosilylation reaction catalyst which is the component (C) of the thermosetting silicone composition of the present invention, all conventionally known ones can be used. For example, carbon powder carrying platinum metal, platinum black, secondary platinum chloride, platinum chloride acid, reaction product of platinum chloride acid and monovalent alcohol, complex of platinum and vinyl siloxane such as divinyltetramethyldisiloxane; Examples include a complex of chloroplatinic acid and olefins, a platinum-based catalyst such as platinum bisacetoacetate; and a platinum group metal-based catalyst such as a palladium-based catalyst and a rhodium-based catalyst.

The amount of the component (C) blended in the thermosetting silicone composition of the present invention may be an effective amount as a catalyst and is not particularly limited, but the above (A-1), (A-2) and (B). It is preferable to add the component (C) in an amount of preferably 1 to 500 ppm, particularly preferably about 2 to 100 ppm, based on the weight of the platinum group metal atom with respect to the total amount of the component (). By setting the blending amount within such a range, the time required for the curing reaction becomes appropriate, and problems such as coloring of the cured product do not occur.

The component (C) can be used alone or in combination of two or more.

（式中、ｓは１〜３の整数であり、ｔは０〜３の整数であり、ｕは０〜３の整数であり、但しｓ＋ｔ＋ｕは４〜５の整数である。ｓが付されたシロキサン単位とｔが付されたシロキサン単位とｕが付されたシロキサン単位とは互いにランダムに配列している。） [(D) component]
Further, it is preferable to add an adhesiveness improver as a component (D) to the thermosetting silicone composition of the present invention. Examples of the adhesiveness improver include a silane coupling agent, an oligomer thereof, and a silicone having a reactive group similar to that of the silane coupling agent. Among these, as the component (D), a compound represented by the following general formula (11) is preferable.

(In the formula, s is an integer of 1 to 3, t is an integer of 0 to 3, u is an integer of 0 to 3, but s + t + u is an integer of 4 to 5. s is added. The siloxane unit, the siloxane unit with t, and the siloxane unit with u are randomly arranged with each other.)

The component (D) is an optional component to be added to the thermosetting silicone composition of the present invention and the cured product to improve the adhesiveness to the substrate. Here, the base material refers to a metal material such as gold, silver, copper, and nickel, a ceramic material such as aluminum oxide, aluminum nitride, and titanium oxide, and a polymer material such as a silicone resin and an epoxy resin. The component (D) can be used alone or in combination of two or more.

The blending amount of the component (D) is preferably 1 to 30 parts by mass, and more preferably 1 with respect to 100 parts by mass of the total of the components (A-1), (A-2), and (B). It is 10 parts by mass. When the blending amount is 1 to 30 parts by mass, the thermosetting silicone composition of the present invention and the cured product thereof effectively improve the adhesiveness to the substrate and are difficult to color.

Preferable specific examples of the component (D) include the following compounds, but the component (D) is not limited thereto.

[Other ingredients]
In addition to the above components, it is optional to add other components to the thermosetting silicone composition of the present invention. Examples of other components include those described below.

２−（ビシクロ［２．２．１］ヘプト−２−エン−５−イル）エチル基

２−（ビシクロ［２．２．１］ヘプト−２−エン−６−イル）エチル基 <Antioxidant>
In the cured product of the thermosetting silicone composition of the present invention, the addition-reactive carbon-carbon double bond in the component (A-1) may remain unreacted. For example, the following The 2- (bicyclo [2.2.1] hept-2-ene-5-yl) ethyl group represented by the structural formula and the 2- (bicyclo [2.2.1] hept) represented by the following structural formula. It may contain carbon-carbon double bonds that are present in either or both of the -2-ene-6-yl) ethyl groups. If such a carbon-carbon double bond is contained, it is oxidized by oxygen in the atmosphere and causes the cured product to be colored. Therefore, coloring can be prevented in advance by adding an antioxidant to the thermosetting silicone composition of the present invention, if necessary.

2- (Bicyclo [2.2.1] hept-2-ene-5-yl) ethyl group

2- (Bicyclo [2.2.1] hept-2-ene-6-yl) ethyl group

As the antioxidant, all conventionally known ones can be used, and examples thereof include hindered amine compounds and hindered phenol compounds, specifically 2,6-di-t-butyl-4-. Methylphenol, 2,5-di-t-amylhydroquinone, 2,5-di-t-butylhydroquinone, 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,2'-methylenebis ( 4-Methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 1,3,5-tris [[3,5-bis (1,1-dimethylethyl) ) -4-Hydroxyphenyl] methyl] -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, N', N', N', N'''-tetrakis [ 4,6-bis [(1,2,2,6,6-pentamethylpiperidin-4-yl) (butyl) amino] -1,3,5-triazine-2-yl] [N', N'' -Ethyl bis (propane-1,3-diamine)] and the like. These can be used alone or in combination of two or more.

When this antioxidant is used, the blending amount thereof is not particularly limited as long as it is an effective amount as the antioxidant, but the components (A-1), (A-2) and (B) described above are not particularly limited. It is preferable to add 10 to 10,000 ppm, particularly preferably about 100 to 1,000 ppm, based on the mass. By setting the blending amount within such a range, the antioxidant ability is sufficiently exhibited, and a cured product having excellent transparency without occurrence of coloring, oxidative deterioration, etc. can be obtained.

<Others>
Further, in order to secure the pot life, an addition reaction control agent such as 1-ethynylcyclohexanol and 3,5-dimethyl-1-hexyne-3-ol can be blended.
Further, it is also possible to use a light stabilizer in order to impart resistance to photodegradation due to light from a light emitting element and light energy such as sunlight. As this light stabilizer, a hindered amine-based stabilizer that captures radicals generated by photooxidation deterioration is suitable, and when used in combination with an antioxidant, the antioxidant effect is further improved. Specific examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 4-benzoyl-2,2,6,6-tetramethylpiperidine and the like.

[Thermosetting silicone composition]
The thermosetting silicone composition (transparent thermosetting silicone composition) of the present invention is liquid before curing, and its viscosity at 25 ° C. is preferably 100 to 5000 mPa · s, more preferably 200 to 1000 mPa · s. s. When the viscosity is in the range of 100 to 5000 mPa · s, the obtained composition tends to have good workability and handleability, and bubbles and air are less likely to be entrained during curing.

The viscosity of the thermosetting silicone composition of the present invention is adjusted by the blending ratios of the components (A-1), (A-2) to (C) and other blending components, the viscosity of the liquid component among these components, and the like. To.

[Silicone resin cured product]
The thermosetting silicone composition of the present invention can be molded and cured by a known method under known curing conditions to obtain a cured silicone resin.
Specifically, the composition can be cured by heating at 80 to 200 ° C., preferably 100 to 160 ° C. The heating time may be about 0.5 minutes to 5 hours, particularly about 1 minute to 3 hours, but when reliability for LED encapsulation or the like is required, it is preferable to lengthen the curing time. The form of the obtained cured product is not particularly limited, and may be, for example, any of a gel cured product, an elastomer cured product, and a resin cured product.

Generally, in order for the cured resin product to function as an optical element encapsulating material, the transmittance of light having a wavelength of 400 nm is preferably 80% or more (that is, 80 to 100%), more preferably 85% or more (that is, that is). 85-100%). When the light transmittance is 80% or more, when the cured product is used as an optical element encapsulating material for a light emitting device such as a lighting fixture, the light extraction efficiency becomes higher and sufficient brightness can be easily secured. .. The light transmittance is preferably maintained at 70% or more not only at the initial stage of production of the cured product but also after the heat resistance test (which is performed by leaving the cured product at 150 ° C. for 500 hours). It is more preferable to maintain 75% or more. The cured silicone resin obtained from the thermosetting silicone resin composition of the present invention has a light transmittance of 80% or more at a wavelength of 400 nm and a light transmittance of 70% or more after being left at 150 ° C. for 500 hours. , Sufficient light transmittance can be obtained as an optical element encapsulating material. In this specification, the light transmittance means a numerical value measured by a spectrophotometer.

Further, the cured silicone resin of the present invention has a gas barrier property, and the water vapor transmittance of the cured product having a thickness of 1 mm is preferably 7 g / m ² · day or less, more preferably 6 g / m ² · day or less at 40 ° C. Is. When the water vapor transmittance is 7 g / m ² · day or less, the gas barrier property is lowered, and the silver electrode is not discolored due to the intrusion of corrosive gas from the outside. As a result, when the cured product is used as an optical element encapsulating material for a light emitting device such as a lighting fixture, sufficient brightness can be ensured without lowering the light extraction efficiency. Therefore, the silicone resin cured product obtained from the thermosetting silicone resin composition of the present invention can obtain sufficient gas barrier properties as an optical element encapsulating material.

The cured product obtained by curing the thermosetting silicone composition of the present invention is excellent in transparency, heat-resistant discoloration, and gas barrier properties as described above, and is similar to the cured product of a normal thermosetting silicone composition. It also has excellent cold resistance and electrical insulation.

[Semiconductor device]
Examples of the optical element sealed by the cured silicone resin of the present invention include LEDs, semiconductor lasers, photodiodes, phototransistors, solar cells, CCDs and the like. Such an optical element is obtained by applying the transparent thermosetting silicone composition of the present invention to the optical element and applying the applied composition under known curing conditions by a known curing method, specifically as described above. Can be sealed by curing to. A semiconductor device coated with such a cured product can be a semiconductor device having excellent reliability.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following example, the viscosity is a value at 25 ° C. measured using a spiral viscometer (Malcom Co., Ltd., model: PC-1T) which is a rotational viscometer.

In the example below, the symbols indicating the composition of silicone oil or silicone resin are shown below. The number of moles of each silicone oil or each silicone resin indicates the number of moles of vinyl group or silicon atom-bonded hydrogen atom contained in each component.
^MH : (CH ₃ ) ₂ HSiO _1/2
M ^Vi : (CH ₂ = CH) (CH ₃ ) ₂ SiO _1/2
M ^ViΦ : (CH ₂ = CH) (C ₆ H ₅ ) (CH ₃ ) SiO _1/2
^DH : (CH ₃ ) HSiO _2/2
D ^Φ : (C ₆ H ₅ ) (CH ₃ ) SiO _2/2
D ^2Φ : (C ₆ H ₅ ) ₂ SiO _2/2
M: (CH ₃ ) ₃ SiO _1/2

[Synthesis Example 1] Preparation of component (A-1) Vinyl norbornene (trade name: V0062, manufactured by Tokyo Kasei Co., Ltd .; 5-) was placed in a 5 L 4-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer. 1785 g (14.88 mol), a mixture of approximately equimolar amounts of vinylbicyclo [2.2.1] hept-2-ene and 6-vinylbicyclo [2.2.1] hept-2-ene. Then, 455 g of toluene was added, and the mixture was heated to 85 ° C. using an oil bath. To this, 3.6 g of carbon powder carrying 5% by mass of platinum was added, and 1698 g (8.75 mol) of 1,4-bis (dimethylsilyl) benzene was added dropwise over 180 minutes with stirring. After completion of the dropping, the mixture was further heated and stirred at 110 ° C. for 24 hours, and then cooled to room temperature. Then, the platinum-supported carbon was filtered off, and toluene and excess vinyl norbornene were distilled off under reduced pressure to obtain 3362 g of a colorless and transparent oily reaction product (viscosity at 25 ° C.: 12820 mPa · s).

（２）ｐ−フェニレン基を３個有する化合物（下記に代表的な構造式の一例を示す）：約３２モル％

（３）ｐ−フェニレン基を４個以上有する化合物：約２７モル％
の混合物であることが判明した。また、混合物全体としての付加反応性炭素−炭素二重結合の含有割合は、０．３６モル／１００ｇであった。 As a result of analyzing the reaction product by FT-IR, NMR, GPC, etc.
(1) A compound having two p-phenylene groups (an example of a typical structural formula is shown below): Approximately 41 mol%,

(2) A compound having three p-phenylene groups (an example of a typical structural formula is shown below): Approximately 32 mol%

(3) Compound having 4 or more p-phenylene groups: Approximately 27 mol%
Turned out to be a mixture of. The content of the addition-reactive carbon-carbon double bond in the mixture as a whole was 0.36 mol / 100 g.

[Examples 1 to 4, Comparative Examples 1 to 3]
The following components (A-1) to (G) were blended in the blending amounts (unit: parts by mass) shown in Table 1 to obtain the respective compositions of Examples 1 to 4 and Comparative Examples 1 to 3. The viscosity of the obtained composition was measured. The results are shown in Table 1.

（Ｄ−２）下記式で表される化合物

（Ｅ）１−エチニル−１−シクロヘキサノールの５０質量％トルエン溶液（付加反応制御剤）
（Ｆ）酸化防止剤：ＢＡＳＦ社製 ＳＡＢＯＳＴＡＢ ＵＶ １１９
（Ｇ）酸化防止剤：チバ・スペシャリティ・ケミカルズ社製 ＩＲＧＡＮＯＸ ３１１４ (A-1) The reaction product obtained in Synthesis Example 1,
(A-2-1) Average molecular formula: ^{Organopolysiloxane represented by M ViΦ} ₂ D ^2Φ ₃ (A-2-2) Average molecular formula: ^{Organopolysiloxane represented by M Vi} ₂ D ^2Φ ₄ (A-3) ) average molecular ^{formula: M} _Vi organopolysiloxane represented by _{^{2 D Φ 6 (B-1}} ) the average molecular _{^{formula: M H 2 D H 2 D}} 2Φ 2, in the organopolysiloxane (B-2 represented) the average molecular formula: Organopolysiloxane (C) platinum-divinyltetramethyldisiloxane complex toluene solution represented by M ₃ ^DH ₆ D ^2Φ _{2 (containing 1% by mass of platinum atom)}
(D-1) Compound represented by the following formula

(D-2) Compound represented by the following formula

(E) 50% by mass toluene solution of 1-ethynyl-1-cyclohexanol (addition reaction control agent)
(F) Antioxidant: BASF SABOSTAB UV 119
(G) Antioxidant: IRGANOX 3114 manufactured by Ciba Specialty Chemicals Co., Ltd.

Next, for the compositions obtained in each Example and Comparative Example, cured products were prepared according to the methods (1) to (4) below (H1 to H4 and H5 to H7 in Table 2, respectively), and performance evaluation was performed. Was carried out. As a curing condition, heat curing was performed at 150 ° C. for 4 hours. The characteristics of the obtained cured product are shown in Table 2.
(1) Measurement of light transmittance A 2 mm thick spacer is attached between two glass plates, the composition is placed in a space of 15 mm × 40 mm × 2 mm, and the above heat curing is performed to obtain a 2 mm thick cured product. It was. The light transmittance of the obtained cured product was measured at 25 ° C. at a measurement wavelength of 400 nm (ultraviolet region) using a spectrophotometer.
(2) Measurement of hardness The hardness (Shore D) of each cured product was measured according to ASTM D 2240.
(3) Evaluation of gas barrier property (water vapor permeability) Prepare a cured product with an outer diameter of 100 mmΦ and a thickness of 1 mm, and measure it at 40 ° C. using a water vapor permeability measuring device (L80-5000 type) manufactured by Systec Illinois. Carried out. The lower the value, the higher the gas barrier property.
(4) Evaluation of Heat Resistant Discoloration The cured products H1 to H7 obtained in (1) above were left at 150 ° C. for 500 hours to perform a heat resistance test. The heat resistance was evaluated by taking the difference between the initial light transmittance obtained in (1) above and the light transmittance after the test. It is evaluated that the smaller the difference in light transmittance, the higher the heat resistance.

As shown in Tables 1 and 2, in Examples 1 to 4 using the thermosetting silicone composition of the present invention, all the compositions had low viscosity and therefore excellent fluidity. The initial light transmittance was high, and the transparency was also excellent. In addition, since the difference between the initial light transmittance and the light transmittance after heat deterioration is small, the heat resistance is also excellent. Furthermore, it was found that the water vapor permeability was low and the gas barrier property was excellent.

On the other hand, in Comparative Example 1, the heat resistance was poor because the light transmittance after heat deterioration was significantly reduced as compared with the initial stage. In Comparative Example 2, it was found that the water vapor transmittance was high and the gas barrier property was low. Further, also in Comparative Example 3, the water vapor transmittance showed a high value, and good gas barrier property could not be obtained.

The above results show that the thermosetting silicone composition of the present invention has high fluidity at room temperature, and the cured product is excellent in transparency and heat resistance (thermostability), especially heat discoloration, and is even higher. It is shown to have gas barrier properties. Therefore, the cured product of the thermosetting silicone composition of the present invention is useful as an optical element encapsulating material, particularly as an encapsulating material for white LEDs.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Claims (9)

(A-1) (a) A compound having two hydrogen atoms bonded to a silicon atom represented by the following general formula (1) in one molecule, and (b) one addition-reactive carbon-carbon double bond. An addition reaction product with two polycyclic hydrocarbons in a molecule, 30 to 70 parts by mass of an addition reaction product having at least two addition-reactive carbon-carbon double bonds in one molecule.
(A-2) 30 to 70 parts by mass of the compound represented by the following general formula (3) (however, the total of the (A-1) component and the (A-2) component is 100 parts by mass).
(B) An organosilicon compound having three or more hydrogen atoms bonded to silicon atoms in one molecule (the total amount of hydrogen atoms bonded to silicon atoms in the composition is the addition-reactive carbon-carbon dicarbonate in the composition. A thermocurable silicone composition comprising (C) a hydrosilylation reaction catalyst (which is an amount such that the molar ratio is 0.5 to 3.0 with respect to the heavy bond).

(A in the formula is a divalent group selected from the group consisting of the groups represented by the following general formula (2), and R ¹ is an independently unsubstituted or substituted monovalent hydrocarbon having 1 to 12 carbon atoms. It is a hydrogen group or an alkoxy group having 1 to 6 carbon atoms.)

(Ph in the formula is a phenyl group, R ² is an independently unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ³ is an addition-reactive carbon-carbon double bond-containing group. Yes, n is an integer from 1 to 20.) The thermosetting silicone composition according to claim 1, wherein the (b) is an alkenylnorbornene compound represented by the following general formula (4).

(Wherein, ^{R 4} is unsubstituted or substituted alkenyl group having 2 to 12 carbon atoms.) (B) is any of 5-vinylbicyclo [2.2.1] hept-2-ene, 6-vinylbicyclo [2.2.1] hept-2-ene, and combinations thereof. The thermosetting silicone composition according to claim 1 or 2, characterized in that there is. The thermosetting silicone composition according to any one of claims 1 to 3, wherein the component (B) is a siloxane compound represented by the following general formula (5).

(In the formula, R ⁵ is an independently unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms other than a hydrogen atom or an alkenyl group, R ⁶ is a methyl group or a hydrogen atom, and p is 1. An integer of 10 and q are integers of 0 to 7. The siloxane unit with p and the siloxane unit with q are randomly arranged with each other.) A silicone resin cured product obtained by curing the thermosetting silicone composition according to any one of claims 1 to 4. Immediately after curing, the transmittance of light having a wavelength of 400 nm is 80% or more, and the transmittance of light having a wavelength of 400 nm after exposure for 500 hours under a 150 ° C. environment is maintained at 70% or more. The cured silicone resin product according to claim 5. It has gas barrier properties, water vapor transmission rate of 1mm the cured product of the thickness of the silicone resin curing according to claim 5 or claim 6, characterized in that following 7g / m 2 · ^day at 40 ° C. Stuff. A semiconductor device in which an optical element is sealed with the cured silicone resin according to any one of claims 5 to 7. The semiconductor device according to claim 8, wherein the optical element is an LED (light emitting diode).