CN110294936A - Addition curable silicon-ketone composition, silicone cure object and optical semiconductor device - Google Patents

Abstract

The present invention provides an addition-curable silicone composition that produces a cured product that has little change in hardness and weight loss under high-temperature conditions, and does not bleed even when exposed to near-ultraviolet to ultraviolet light in a high-temperature and high-humidity environment. Oil. The addition-curable silicone composition contains the following components, and is cured by heating: (A) a straight-chain compound having at least 2 alkenyl groups in each molecule represented by the following average composition formula (1): Shaped organopolysiloxane, (R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ R ² SiO _1/2 ) _b (R ¹ ₂ SiO) _c (R ¹ R ² SiO) _d ... (1); (B) organohydrogenpolysiloxanes having at least 2 silicon-bonded hydrogen atoms in each molecule and no addition-reactive carbon-carbon double bonds; (C) platinum group metal-containing hydridosilanes and (D) polyorganometallic siloxanes having Si-O-Ce bonds and Si-O-Ti bonds.

Description

Addition-curable silicone composition, silicone cured product, and optical semiconductor device

technical field

The present invention relates to an addition-curable silicone composition, its cured product, and an optical semiconductor device using the cured product as a sealing material.

Background technique

Epoxy resins are generally used as sealing materials for LED elements, but Patent Documents 1 to 3 propose using silicone resins as sealing materials instead of epoxy resins. Compared with epoxy resins, silicone resins are superior in heat resistance, weather resistance, and discoloration resistance, so they are mainly used for blue LEDs and white LEDs.

However, as the amount of electricity to LEDs has increased in recent years, the temperature near the LED elements has risen, and even when silicone resins are used, there have been problems of deterioration of the sealing material, cracks, and a drop in light transmittance due to discoloration.

Furthermore, the use of high-output short-wavelength LED elements has increased, and the silicone resin has deteriorated due to energization in a high-temperature, high-humidity environment, and liquid silicone has emerged on the surface of the silicone resin (bleeding). oil) etc.

From such a background, in recent years, sealing materials for LED elements have been required to have long-term reliability (that is, heat resistance) in a high-temperature environment or light resistance to short-wavelength light in a high-temperature and high-humidity environment.

As a common silicone material with improved heat resistance, it has been reported so far that a base organopolysiloxane is mixed with organopolysiloxane, cerium carboxylate, and titanium at a temperature of 150°C or higher. heat-resistant organopolysiloxane composition (Patent Document 4) or a silicone gel composition containing the same additive as an additive (Patent Document 5) . However, the compositions described in these patent documents are not addition-curable silicone compositions that form a cured product having rubber hardness, and therefore cannot be used in applications such as sealing materials for LED elements as described above.

On the other hand, Patent Document 6 reports a heat-resistant silicone rubber composition containing a mixture of rare earth salts of 2-ethylhexanoic acid, and reports the total light transmittance at a wavelength of 600 nm of a sheet having a thickness of 2 mm. For more than 90%. However, this heat-resistant silicone rubber composition has a problem in that the light transmittance of short-wavelength light around a wavelength of 400 nm is poor.

prior art literature

patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 11-001619

Patent Document 2: Japanese Patent Laid-Open No. 2002-265787

Patent Document 3: Japanese Patent Laid-Open No. 2004-186168

Patent Document 4: Japanese Patent Application Laid-Open No. 60-163966

Patent Document 5: Japanese Patent Laid-Open No. 2008-291148

Patent Document 6: International Publication No. WO2013/079885 Handbook

Contents of the invention

The technical problem to be solved in the present invention

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an addition-curable silicone composition that produces a cured product whose hardness change and weight loss are small under high temperature conditions, and which can be used even under high temperature and high humidity. Oil leakage does not occur when exposed to near ultraviolet to ultraviolet light in the environment.

Technical means to solve technical problems

In order to achieve the above technical problems, the present invention provides an addition-curable silicone composition, which is characterized in that it contains the following components and is cured by heating:

(A) a linear organopolysiloxane having at least 2 alkenyl groups per molecule represented by the following average composition formula (1),

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

In the formula, R1 is each independently ^a substituted or unsubstituted monovalent hydrocarbon group, R2 is an alkenyl group, a and b are ⁰ or positive numbers, c and d are positive numbers, and satisfy a+b>0, 0.01 ≤(b+d)/(a+b+c+d)≤0.03;

(B) organohydrogenpolysiloxanes having at least 2 silicon-bonded hydrogen atoms in each molecule and no addition-reactive carbon-carbon double bonds;

(C) a hydrosilylation catalyst containing a platinum group metal; and

(D) A polyorganometallic siloxane having Si-O-Ce bonds and Si-O-Ti bonds.

Such an addition-curable silicone composition has little change in hardness and weight loss under high-temperature conditions, and produces a cured product that does not bleed oil even when exposed to near-ultraviolet to ultraviolet light in a high-temperature and high-humidity environment.

Furthermore, the present invention provides a cured silicone product obtained by curing the aforementioned addition-curable silicone composition.

Such a cured silicone product can be suitably used as a material for sealing optical elements such as LEDs.

In addition, when the silicone cured product is formed into a sheet with a thickness of 2 mm, it is preferable that the initial total light transmittance at 400 nm is 80% or more, and the weight loss after storage at 250° C. for 500 hours is within 10%.

Such a silicone cured product is excellent in transparency and has little weight loss in a high-temperature environment, so it is particularly suitable as a material for sealing optical elements and the like.

Furthermore, the present invention provides an optical semiconductor device characterized by sealing an optical element with the above-mentioned cured silicone.

Such an optical semiconductor device is excellent in reliability under high temperature conditions because the optical element is sealed with the silicone cured product having excellent transparency and little weight loss under high temperature conditions.

Preferably, the optical element is an LED element that emits light with a wavelength of 300-440nm, and when a current of 200mA is passed to the LED element for 500 hours in an environment of 85°C and 85%Rh, no oil seepage occurs on the surface of the silicone cured product .

Such an optical semiconductor device does not cause oil leakage even in a high-temperature, high-humidity environment, and therefore is particularly excellent in reliability.

Invention effect

As described above, the addition-curable silicone composition of the present invention is an addition-curable silicone composition that produces a cured product that is excellent in transparency and heat discoloration resistance, and changes in hardness in a high-temperature environment. And the weight loss is small, and even when exposed to near-ultraviolet to ultraviolet light in a high-temperature and high-humidity environment, oil bleeding accompanying the deterioration of the silicone resin does not occur, and the cured product has good crack resistance. Therefore, the addition-curable silicone composition of the present invention is particularly useful as a material for protection and sealing of LED elements, a material for changing and adjusting wavelengths, a material for constituting lenses, or materials for other optical devices or optical parts. .

Description of drawings

FIG. 1 is a schematic cross-sectional view showing an example of the optical semiconductor device of the present invention.

Explanation of reference signs

1: optical element; 2: lead electrode; 3: die bonding material; 4: gold wire; 5: light-reflecting resin; 6: silicone cured product; 7: optical semiconductor device.

Detailed ways

As mentioned above, there is a demand for the development of an addition-curable silicone combination that produces a cured product that exhibits little change in hardness and weight loss under high-temperature conditions and does not bleed oil even when exposed to near-ultraviolet to ultraviolet light in a high-temperature, high-humidity environment. things.

The inventors of the present application conducted earnest research and found that an addition-curable silicone composition containing the following components (A) to (D) can achieve the above-mentioned technical problems and is suitable for sealing optical elements. etc., thereby completing the present invention.

That is, the present invention is an addition-curable silicone composition, which contains the following components (A) to (D), and is cured by heating:

(A) a linear organopolysiloxane having at least 2 alkenyl groups per molecule represented by the following average composition formula (1),

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

In the formula, R1 is each independently ^a substituted or unsubstituted monovalent hydrocarbon group, R2 is an alkenyl group, a and b are ⁰ or positive numbers, c and d are positive numbers, and satisfy a+b>0, 0.01 ≤(b+d)/(a+b+c+d)≤0.03;

(B) organohydrogenpolysiloxanes having at least 2 silicon-bonded hydrogen atoms in each molecule and no addition-reactive carbon-carbon double bonds;

(C) a hydrosilylation catalyst containing a platinum group metal; and

(D) A polyorganometallic siloxane having Si-O-Ce bonds and Si-O-Ti bonds.

The present invention will be described in detail below, but the present invention is not limited thereto.

＜Addition-curable silicone composition＞

The addition-curable silicone composition of this invention contains following (A)-(D) component. The addition-curable silicone composition of the present invention can be prepared by mixing the following components (A) to (D) and, if necessary, the following other components by a conventionally known method.

Each component will be described in detail below.

[(A) ingredient]

The (A) component in the addition-curable silicone composition of the present invention is a component that reacts with the (B) component described later to form a cured product, and has an effect on the cured product obtained by curing the composition. to the effect of stress relaxation. Component (A) is a straight-chain organopolysiloxane represented by the following average composition formula (1) and having at least two alkenyl groups per molecule.

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

In the formula, R1 is each independently ^a substituted or unsubstituted monovalent hydrocarbon group, R2 is an alkenyl group, a and b are ⁰ or positive numbers, c and d are positive numbers, and satisfy a+b>0, 0.01 ≤(b+d)/(a+b+c+d)≤0.03.

In the above average composition formula (1), (b+d)/(a+b+c+d) is in the range of 0.01 to 0.03, preferably in the range of 0.013 to 0.024. When (b+d)/(a+b+c+d) is less than 0.01, when the cured product of the above-mentioned silicone composition is exposed to light from near ultraviolet to ultraviolet light in a high-temperature and high-humidity environment, oil leakage will occur. If it exceeds 0.03 , the cured product becomes brittle and cracks in a high temperature environment.

In the above-mentioned average composition formula ( ¹ ), the substituted or unsubstituted monovalent hydrocarbon group represented by R1 is not particularly limited, and each independently preferably is a monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly preferably a carbon number A monovalent hydrocarbon group of 1 to 8, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octane Alkyl groups such as base, nonyl, decyl; Aryl groups such as phenyl, tolyl, xylyl, naphthyl; Aralkyl groups such as benzyl, phenylethyl, phenylpropyl, etc., particularly preferably methyl .

In the above-mentioned average composition formula ( ¹ ), the alkenyl group represented by R2 is not particularly limited, but each independently preferably is an alkenyl group having 1 to 10 carbon atoms, particularly preferably an alkenyl group having 1 to 6 carbon atoms. As a group, a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group etc. are mentioned, A vinyl group is especially preferable.

Specific examples of the component (A) are not particularly limited, and examples include trimethylsiloxy-terminated dimethylsiloxane-methylvinylsiloxane copolymers at both ends of the molecular chain, trimethylvinylsiloxane copolymers at both ends of the molecular chain, Methylsiloxy-blocked dimethylsiloxane, diphenylsiloxane, methylvinylsiloxane copolymer, dimethylvinylsiloxy-blocked dimethylsiloxane at both ends of the molecular chain Alkane·methyl vinyl siloxane copolymer, etc.

(A) Component may be used individually by 1 type, and may use 2 or more types which differ in molecular weight, the kind of the organic group bonded to a silicon atom, etc. together.

The viscosity of component (A) at 25°C is not particularly limited, but it is most preferably 50 to 100,000 mPa·s, more preferably 1,000 to 50,000 since the workability of the composition or the optical or mechanical properties of the cured product are more excellent. mPa·s is particularly preferably in the range of 1,000 to 10,000 mPa·s. When the viscosity is satisfied, the degree of polymerization is usually 50 to 1,000, preferably 200 to 800, and more preferably 200 to 600.

The molecular weight of the component (A) is not particularly limited, but it is preferably 1,000 to 100,000, more preferably 1,000 to 100,000 in terms of weight average molecular weight (Mw) measured by GPC (gel permeation chromatography) using a THF (tetrahydrofuran) solvent. 5,000 to 70,000, particularly preferably 10,000 to 50,000.

Moreover, (A) component has at least 2 alkenyl groups per molecule, Preferably it has 3-30 alkenyl groups. When (A) component has such a number of alkenyl groups, the effect of this invention can be heightened further.

[(B) ingredient]

The component (B) in the addition-curable silicone composition of the present invention has at least 2 hydrogen atoms (that is, SiH groups) bonded to silicon atoms in each molecule and does not have addition-reactive carbon. An organohydrogenpolysiloxane having a carbon double bond undergoes a hydrosilylation reaction with the above-mentioned (A) component, and functions as a crosslinking agent.

(B) The molecular structure of the organohydrogenpolysiloxane of the component is not particularly limited, and examples thereof include linear, cyclic, branched, three-dimensional network structures (resin), and the like, preferably linear or cyclic. shape.

(B) The organohydrogenpolysiloxane of the component preferably has 3 to 300 SiH groups in 1 molecule on average, and more preferably has 4 to 150 SiH groups.

In (B) component 100g, content of the hydrogen atom bonded to the said silicon atom in (B) component becomes like this. Preferably it is 0.001-5 mol, Especially preferably, it is 0.01-2 mol.

(B) The position of the SiH group in the organohydrogenpolysiloxane molecule of the component may be at the terminal or non-terminal of the molecular chain, or may be at both the terminal and the non-terminal.

In the organohydrogenpolysiloxane molecule of the component (B), the silicon atom-bonded organic group other than the silicon atom-bonded hydrogen atom is not particularly limited, for example, it is preferably unsubstituted or substituted, and the number of carbon atoms is A monovalent hydrocarbon group of 1 to 10, more preferably an unsubstituted or substituted monovalent hydrocarbon group having ¹ to 6 carbon atoms, and specific examples thereof include those exemplified as R in the component (A) above. The same monovalent hydrocarbon group as the given group.

Specific examples of organohydrogenpolysiloxane as component (B) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane alkane, methylhydrogen cyclopolysiloxane, dimethylsiloxane-methylhydrogensiloxane cyclic copolymer, tris(dimethylhydrogensiloxy)methylsilane, tris(dimethylhydrogensilane Oxy)phenylsilane, trimethylsiloxy-terminated methylhydrogen polysiloxane at both ends of the molecular chain, trimethylsiloxy-terminated dimethylsiloxane at both ends of the molecular chain Methyl hydrogen siloxane Oxane copolymer, trimethylsiloxy-terminated dimethylsiloxane, methylhydrogensiloxane, methylphenylsiloxane copolymer at both ends of the molecular chain, dimethylhydrogen silicon at both ends of the molecular chain Oxygen-terminated dimethylpolysiloxane, dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer at both ends of the molecular chain, dimethylhydrogensiloxane at both ends of the molecular chain Oxygen-terminated dimethylsiloxane·methylphenylsiloxane copolymer, dimethylhydrogensiloxy-terminated methylphenyl polysiloxane at both ends of the molecular chain, the formula: (CH ₃ ) A copolymer of a siloxane unit represented by ₂ HSiO _1/2 and a siloxane unit represented by the formula: (CH ₃ ) ₃ SiO _1/2 and a siloxane unit represented by the formula: SiO _4/2 , Copolymers of siloxane units represented by the formula: (CH ₃ ) ₂ HSiO _1/2 and siloxane units represented by the formula: SiO _4/2 , two or more of these organopolysiloxanes formed mixtures, etc.

The viscosity of component (B) at 25°C is not particularly limited, but it preferably satisfies 0.1 to 5,000 mPa·s, more preferably 0.5 to 1,000 mPa·s, since the workability of the composition or the optical or mechanical properties of the cured product are more excellent. s, particularly preferably satisfying the range of 2 to 500 mPa·s, most preferably in the range of being liquid at room temperature (25°C). When this viscosity is satisfied, the number of silicon atoms (or degree of polymerization) in one molecule of the organohydrogenpolysiloxane is usually 2 to 1,000, preferably 3 to 300, and more preferably 4 to 150.

The molecular weight of the component (B) is not particularly limited, but is preferably 100 to 10,000, more preferably 200 to 5,000, particularly preferably 500 to 3,000 in terms of standard polystyrene as measured by GPC using a THF solvent.

The blending amount of the component (B) is not particularly limited, but is preferably an amount sufficient to cure the addition-curable silicone composition in the presence of the following hydrosilylation catalyst (component (C)), more preferably In order to make the molar ratio of SiH in (B) component with respect to the alkenyl group in the said (A) component 0.4-4.0, it is more preferable that it is the quantity which makes the said molar ratio 0.6-3.0.

[(C) ingredient]

Component (C) is a hydrosilylation catalyst (platinum group metal-based hydrosilylation catalyst) containing a platinum group metal, and the (C) component is used to promote the reaction with the above-mentioned (A) component and (B) component (hydrosilane Components that function as reaction catalysts.

As (C)component, any catalyst can be used as long as it promotes the hydrosilylation addition reaction of the alkenyl group in the said (A) component, and the SiH group in the said (B) component. (C) A component may be used individually by 1 type, and may use 2 or more types together. Such catalysts include, for example, platinum group metals such as platinum, palladium, and rhodium, chloroplatinic acid, alcohol-modified chloroplatinic acid, complexes of chloroplatinic acid with olefins, vinylsiloxanes, or acetylene compounds, and tetrahydrocarbons. Platinum group metal compounds such as (triphenylphosphine)palladium and tris(triphenylphosphine)rhodium chloride are particularly preferably platinum compounds. (C) A component may be used individually by 1 type, and may use 2 or more types together.

(C) The blending amount of the component is not particularly limited, and may be an effective amount as a hydrosilylation catalyst. In terms of the mass of the platinum group metal, it is preferably 0.1 to the total mass of the above-mentioned (A) component and (B) component. It is in the range of ˜1000 ppm, more preferably in the range of 1-500 ppm.

[(D) ingredient]

The component (D) in the addition-curable silicone composition of the present invention is a polyorganometallic siloxane having Si-O-Ce bonds and Si-O-Ti bonds, and is used to improve the addition curing of the present invention. Additives for heat resistance of type silicone compositions.

The component (D) is preferably a polyorganometallic siloxane having a Ce content of 50 to 5,000 ppm, a Ti content of 50 to 5,000 ppm, and a viscosity at 25°C of 10 to 10,000 mPa·s.

As (D) component, the reaction product obtained by heat-processing the mixture which consists of following (i), (ii), and (iii) components at the temperature of 150 degreeC or more is preferable, for example.

(i) organopolysiloxane having a viscosity of 10 to 10,000 mPa·s at 25°C: 100 parts by mass;

(ii) Rare earth carboxylate containing cerium carboxylate represented by the following general formula (D-1): 0.05 to 5 parts by mass relative to 100 parts by mass of component (i) in terms of cerium ,

(R ³ COO) _y Ce···(D-1)

In the formula, R ³ is the same or different monovalent hydrocarbon groups, y is 3 or 4; and

(iii) At least one of titanium compounds represented by the following general formula (D-2) or hydrolyzed condensates thereof: 0.05 to 5 parts by mass relative to 100 parts by mass of component (i) in terms of titanium quantity,

(R ⁴ O) ₄ Ti...(D-2)

In the formula, R ⁴ is the same or different monovalent hydrocarbon groups.

As the organopolysiloxane of the (i) component, conventionally known components can be used as long as the viscosity at 25° C. is 10 to 10,000 mPa·s.

Examples of the rare earth carboxylate of the component (ii) include cerium salts such as 2-ethylhexanoic acid, naphthenic acid, oleic acid, lauric acid, and stearic acid.

As a titanium compound of (iii) component, tetraalkoxytitanium, such as n-butyl tetratitanate, or its hydrolysis condensate, etc. are illustrated.

The blending amount of the component (D) is not particularly limited, but from the viewpoint of imparting heat resistance to the obtained cured product and suppressing discoloration or reduction in hardness, relative to the total of 100 parts by mass of the above-mentioned components (A) to (C), Preferably it is 0.01-5 mass parts, More preferably, it is 0.01-3 mass parts, More preferably, it is 0.5-3 mass parts.

[other ingredients]

In addition to the above-mentioned (A)-(D) components which are essential components, the addition-curable silicone composition of this invention can mix other components illustrated below as needed.

As other components, for example, light scattering agents such as crystalline silica or reinforcing materials; phosphors; petroleum solvents; viscosity modifiers such as non-reactive silicone oils that do not have reactive functional groups; An adhesiveness improving agent composed of a component and a compound other than the above-mentioned component (B), the compound containing one or more (meth)acrylic group, epoxy group, alkoxysilyl group, amide group in one molecule and at least one or more of the functional group group consisting of carboxylic acid anhydride groups; addition reaction inhibitors such as 2-ethynyl 2-dodecanol and 1-ethynyl cyclohexanol, etc. These other components may be used alone or in combination of two or more.

＜Silicone cured product＞

The addition-curable silicone composition of the present invention can be cured by a known curing method under known curing conditions to obtain a cured silicone product. The curing conditions of the addition-curable silicone composition of the present invention are not particularly limited, but can be cured, for example, by heating at 80 to 200°C, preferably at 120 to 180°C. The heating time is, for example, about 0.5 minutes to 5 hours, preferably about 30 to 180 minutes, and when precision is required for LED sealing, etc., it is more preferable to prolong the curing time.

It is preferable that when the silicone cured product obtained by curing the addition-curable silicone composition of the present invention (for example, by heating at 150° C. for 2 hours) is formed into a sheet with a thickness of 2 mm, the initial total light transmission at 400 nm is The rate is above 80%.

In addition, for the silicone cured product obtained by curing the addition-curable silicone composition of the present invention (for example, by heating at 150°C for 2 hours), the rate of change in hardness after storage at 250°C for 300 hours is preferably within 30%. , The weight reduction rate is within 10%.

Such a cured silicone product is particularly suitable as a material for sealing optical elements and the like because it is excellent in transparency and has little weight loss in a high-temperature environment.

＜Optical Semiconductor Device＞

Moreover, this invention provides the optical semiconductor device which sealed the optical element using the hardened|cured material (silicone cured material) of the above-mentioned addition-curable silicone composition.

FIG. 1 is a schematic cross-sectional view of an example of the optical semiconductor device of the present invention. In the optical semiconductor device 7 shown in FIG. 1 , an optical element 1 is fixed on a frame body having a pair of lead electrodes 2 using a die bonding material 3 , and a light reflector is formed on the outer periphery of the optical element 1 . Resin 5. The optical element 1 and the lead electrode 2 are connected by a gold wire 4 and sealed with a cured silicone product 6 cured by pouring the addition-curable silicone composition of the present invention.

Examples of optical elements sealed with a cured product of the addition-curable silicone composition of the present invention include LEDs, semiconductor lasers, photodiodes, phototransistors, solar cells, and CCDs. Such an optical element can be sealed by coating the optical element with a sealing material formed of the addition-curable silicone composition of the present invention, and using a known curing method under known curing conditions, for example, under the above-mentioned conditions. Let the applied sealing material cure. The optical semiconductor device of the present invention obtained by sealing the optical element in this way is excellent in reliability because the semiconductor element is sealed using the addition-curable silicone composition that generates a cured product, and the cured product is excellent in transparency, and Hardness changes and weight loss are small in high temperature environments, and oil leakage does not occur even when exposed to near-ultraviolet to ultraviolet light in high-temperature and high-humidity environments.

In addition, it is preferable that the optical semiconductor device of the present invention seals an LED emitting light having a wavelength of 300 to 440 nm using a cured product obtained by curing (for example, heating and curing at 150° C. for 2 hours) the above-mentioned addition-curable silicone composition. , under the environment of 85° C. and 85% Rh, when a current of 200 mA is passed to the LED for 500 hours, no oil seepage occurs on the surface of the silicone cured product.

Such an optical semiconductor device is particularly excellent in reliability because oil leakage does not occur in a high-temperature, high-humidity environment.

As described above, the addition-curable silicone composition of the present invention is particularly useful as a material for protection and sealing of LED elements, a material for changing and adjusting wavelengths, a material for constituting lenses, and materials for other optical devices or optical parts. useful.

Example

Hereinafter, the present invention will be specifically described using synthesis examples, examples, and comparative examples, but the present invention is not limited thereto.

In the following examples, the symbols indicating the composition of silicone oil or silicone resin are as follows.

M: (CH ₃ ) ₃ SiO _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

D ^Vi : (CH ₂ =CH)(CH ₃ )SiO _2/2

[Synthesis Example 1]

(D) Preparation of ingredients

10 parts by mass (the amount of cerium is 0.55 parts) of turpentine oil solution (rare earth element content is 6 mass %) and 2.1 mass parts of n-butyl tetratitanate ( The mass of titanium is 0.3 times the mass of cerium in the 2-ethylhexanoate), and the mixture is fully stirred and added to 100 parts by mass of trimethylsiloxy-terminated trimethylsiloxy at both ends with a viscosity of 100 mPa·s. In dimethylpolysiloxane, a yellow-white dispersion liquid was obtained. A small amount of nitrogen gas was passed through it while heating to make the turpentine flow out, and then heated at 300° C. for 1 hour to obtain a thick reddish-brown transparent polyorganometallic siloxane.

[Examples 1-5, Comparative Examples 1-5]

The following components were blended in the blending amounts (unit: parts by mass) shown in Table 1 to obtain an addition-curable silicone composition.

(A-1) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₄₅ D ^Vi _4.5 (vinyl group: 0.19 mmol/g) and a viscosity of 5.0 Pa·s

(A-2) An organopolysiloxane represented by the average composition formula M ₂ D ₅₅₀ D ^Vi _5.5 (vinyl group: 0.13 mmol/g) and a viscosity of 10.0 Pa·s

(A-3) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₄₀ D ^Vi ₉ (vinyl group: 0.33 mmol/g) and a viscosity of 5.0 Pa·s

(A-4) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₅₀ (vinyl group: 0.06 mmol/g) and a viscosity of 5.0 Pa·s

(A-5) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₀₅ D ^Vi ₄₅ (vinyl group: 1.38 mmol/g) and a viscosity of 5.0 Pa·s

(A-6) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₅₅₀ D ^Vi ₁ (vinyl group: 0.07 mmol/g) and a viscosity of 10.0 Pa·s

(A-7) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₄₅ D ^Vi _2.5 (vinyl group: 0.13 mmol/g) and a viscosity of 4.8 Pa·s

(A-8) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₄₀ D ^Vi _11.5 (vinyl group: 0.40 mmol/g) and a viscosity of 5.3 Pa·s

(A-9) An organopolysiloxane represented by the average composition formula M ^Vi ₂ D ₄₃₅ D ^Vi ₁₆ (vinyl group: 0.53 mmol/g) and a viscosity of 5.5 Pa·s

(B) An organopolysiloxane represented by the average composition formula M ₂ D ^H ₄ D ₂₄ (SiH group: 1.81 mmol/g) and a viscosity of 25 mPa·s

(C) Platinum-divinyltetramethyldisiloxane complex toluene solution (platinum content: 1% by mass)

(D) The polyorganometallic siloxane obtained in Synthesis Example 1 above

Other ingredients:

(E) A compound (adhesion improving agent) represented by the following formula (2):

[chemical formula 2]

(F) 1-ethynyl cyclohexanol (addition reaction control agent)

[Table 1]

The addition-curable silicone composition obtained in said Examples 1-5 and Comparative Examples 1-5 was evaluated by the following test. The results are shown in Table 2.

[Transmittance]

The addition-curable silicone compositions obtained in Examples and Comparative Examples were heated and cured at 150° C. for 2 hours to obtain cured products with a thickness of 2 mm. The light transmittance (optical path length: 2 mm) of the wavelength of 400 nm of the obtained hardened|cured material was measured using the spectrophotometer.

[Hardness of cured product (initial stage)]

The addition-curable silicone resin composition obtained in each Example and each comparative example was heated at 150 degreeC for 2 hours. The hardness of the obtained cured product was measured at 25° C. using a Durometer A-type hardness meter.

[Hardness after heat resistance test]

After the cured product used in the hardness measurement was stored at 250° C. for 500 hours, the hardness of the cured product was measured at 25° C. using a Durometer A-type hardness meter.

[Weight change rate (weight residual rate) in heat resistance test]

The initial weight of the hardened|cured material used for the said light transmittance measurement, and the weight after storage in the environment of 250 degreeC and 300 hours were measured. The ratio of the weight after the heat resistance test when the initial weight was set to 100 was determined as the weight residual ratio.

[High temperature conduction test]

The optical semiconductor device 7 shown in FIG. 1 mounted with an LED chip having an emission peak of 405 nm was used as an optical element. The optical element 1 is fixed to a frame having a pair of lead electrodes 2 using a die-bonding material 3 . After connecting the optical element 1 and the lead electrode 2 with the gold wire 4, the addition-curable silicone composition obtained in each Example and each comparative example was poured and cured at 150° C. for 2 hours to manufacture an optical semiconductor device 7 . The fabricated optical semiconductor device was energized to emit light at 350 mA in an environment of 120°C. After 500 hours, the appearance of the sealing resin was observed under a microscope to confirm the presence or absence of cracks. In Table 2, the case where no cracks occurred and no abnormality was marked as ◯, and the case where cracks occurred was marked as ×.

[High temperature and high humidity electrification test]

In an environment of 85° C. and 85% Rh, the optical semiconductor device produced by the same method as the above-mentioned high-temperature current conduction test was energized to emit light at 200 mA. After 500 hours, the appearance of the sealing resin was observed under a microscope to confirm whether oil leakage occurred. In Table 2, the case where oil leakage did not occur and no abnormality was marked as ◯, and the case where oil leakage occurred was marked as ×.

[Table 2]

As shown in the above Table 2, in Examples 1 to 5, the transparency was excellent, the hardness change under high temperature conditions was small, and the weight loss was small (that is, the weight residual ratio was large). In addition, even when exposed to near-ultraviolet to ultraviolet light in a high-temperature, high-humidity environment, no oil leakage or cracks occurred, which was good. On the other hand, in Comparative Examples 1 to 4 using alkenyl-group-containing organopolysiloxanes that did not satisfy the conditions of component (A) of the present invention, cracks occurred in the high-temperature electric test, or cracks occurred at high temperature and high temperature. Oil leakage occurred in the wet current test. In addition, in Comparative Example 5 which did not contain the component (D) of the present invention, the change in physical properties under high-temperature conditions became remarkable, and cracks occurred in the high-temperature electrical test.

In addition, this invention is not limited to the said embodiment. The above-mentioned embodiments are examples, and technical solutions that have substantially the same configuration as the technical idea described in the claims of the present invention and exhibit the same functions and effects are included in the technical scope of the present invention.

Claims (5)

1. An addition-curable silicone composition, characterized in that it contains the following ingredients and is cured by heating: (A) a linear organopolysiloxane having at least 2 alkenyl groups per molecule represented by the following average composition formula (1), (R ¹ ₃ SiO _1/2 ) _a (R ¹ ₂ R ² SiO _1/2 ) _b (R ¹ ₂ SiO) _c (R ¹ R ² SiO) _d (1) In the formula, R1 is each independently ^a substituted or unsubstituted monovalent hydrocarbon group, R2 is an alkenyl group, a and b are ⁰ or positive numbers, c and d are positive numbers, and satisfy a+b>0, 0.01 ≤(b+d)/(a+b+c+d)≤0.03; (B) organohydrogenpolysiloxanes having at least 2 silicon-bonded hydrogen atoms in each molecule and no addition-reactive carbon-carbon double bonds; (C) a hydrosilylation catalyst containing a platinum group metal; and (D) A polyorganometallic siloxane having Si-O-Ce bonds and Si-O-Ti bonds. 2. A silicone cured product, characterized in that it is obtained by curing the addition-curable silicone composition according to claim 1. 3. The silicone cured product according to claim 2, characterized in that, when the silicone cured product is made into a sheet with a thickness of 2 mm, the total light transmittance at the initial stage of 400 nm is 80% or more. The weight loss after storage at 250°C for 500 hours was within 10%. 4. An optical semiconductor device characterized in that it is formed by sealing an optical element with the silicone cured product according to claim 2 or 3. 5. The optical semiconductor device according to claim 4, wherein the optical element is an LED element that emits light with a wavelength of 300 to 440 nm, and the LED element is fed with When a current of 200mA is used for 500 hours, no oil seepage occurs on the surface of the silicone cured product.