KR20180097664A - Silicone resin composition and sealing material for semiconductor light emitting device - Google Patents

Abstract

There is provided a silicone resin composition useful in the production of a cured product of a silicone resin composition having high UV stability. A silicone resin composition comprising at least one silicone resin, which satisfies the following requirements (i) - (iii). (I) the silicon atom contained therein is substantially composed of A1 silicon atoms and / or A2 silicon atoms and A3 silicon atoms, and the ratio of the content of A3 silicon atoms to the total content of A1 silicon atoms to A3 silicon atoms is 50 mol % Or more and 99 mol% or less. (Ii) the side chain bonded to the silicon atom is an alkyl group, an alkoxy group or a hydroxyl group, the molar ratio of the alkoxy group is less than 5 per 100 alkyl groups, and the molar ratio of hydroxyl groups is 100 or more per 100 alkyl groups. (Iii) a curing catalyst substantially containing no metal catalyst and containing no metal, and the concentration of the curing catalyst in the composition is 600 ppm or less.

Description

Silicone resin composition and sealing material for semiconductor light emitting device

The present invention relates to a silicone resin composition and a sealing material for a semiconductor light emitting device. More particularly, the present invention relates to a silicone resin composition, a cured product of the silicone resin composition, and a sealing material for a semiconductor light emitting device comprising a cured product of the silicone resin composition.

In recent years, UV (ultraviolet) -LEDs are beginning to appear on the market. Quartz glass is commonly used for the sealing of UV-LEDs. However, since quartz glass is expensive, the price of the product is high and the market competitiveness is low. Further, when the UV-LED is sealed using quartz glass, a space (sealing space) exists between the UV-LED and the quartz glass. Since the difference in refractive index between the space and the surface of the UV-LED and the refractive index difference at the interface between the space and the surface of the quartz glass are both large, the UV light is reflected, There was a problem that it was low. Therefore, it has been proposed to use a cured product of a silicone resin composition as a sealing material for UV-LED.

For example, Patent Document 1 discloses the use of an ultraviolet transparent polysilsesquioxane glass having an absorption coefficient of 230 cm to 850 nm of 5 cm ^-1 or less as a sealing material.

Japanese Unexamined Patent Application Publication No. 2013-253223

However, the cured product of the above-mentioned silicone resin composition has insufficient transmittance to UV light. Further, the cured product of the silicone resin composition is easily deteriorated by UV light as compared with quartz glass, and the transmittance to UV light is further lowered by deterioration. Therefore, there has been a demand for a cured product of a silicone resin composition capable of transmitting UV light with high transmittance over a long period of time in using a cured product of the silicone resin composition as a sealing material for UV-LED.

In a sealing material using a cured product of a silicone resin composition, what is hardly deteriorated by UV light is sometimes referred to as " UV stability ". Further, in a sealing material using a cured product of a silicone resin composition, there is a case where it is difficult to be deteriorated by UV light, and the characteristic of transmitting UV light with high transmittance over a long period of time is referred to as " high UV stability ".

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a silicone resin composition useful for the production of a cured product of a silicone resin composition having high UV stability. The present invention also aims to provide a cured product of the silicone resin composition. It is another object of the present invention to provide a sealing material for a semiconductor light emitting device comprising a cured product of the silicone resin composition.

The present invention provides the following [1] to [5].

[One]

A silicone resin composition comprising at least one silicone resin,

Wherein the silicone resin composition satisfies the following requirements (i) - (iii).

(I) at least one silicon atom selected from the group consisting of A1 silicon atoms and A2 silicon atoms, and A3 silicon atoms, and the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms , The ratio of the content of A3 silicon atoms is 50 mol% or more and 99 mol% or less.

(Ii) the side chain bonded to the silicon atom is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a hydroxyl group, the molar ratio of the alkoxy group is less than 5 per 100 alkyl groups, 100 or more.

(Iii) a curing catalyst which contains substantially no metal catalyst and which does not contain a metal (the curing catalyst is an acid catalyst or a base catalyst), and the catalyst for curing The concentration is 600 ppm (mass per million) or less.

[here,

The A1 silicon atom is a structural unit represented by the following formula (A1) wherein one oxygen atom (the oxygen atom is bonded to a silicon atom in another structural unit), one R ¹ and two R ² Or a structural unit represented by the following formula (A1 '), one bonding hand (the bonding hand is bonded to an oxygen atom bonding with a silicon atom in another structural unit), or a structural unit represented by the following formula Is a silicon atom bonded to one R < ^{1 >} and two R < ² >

The A2 silicon atom is a structural unit represented by the following formula (A2), wherein one oxygen atom (the oxygen atom is bonded to the silicon atom in the other structural unit) and one bonding hand Is bonded to an oxygen atom bonded to a silicon atom in another structural unit), and is a silicon atom bonded to one R ¹ and one R ² .

The A3 silicon atom is a structural unit represented by the following formula (A3) wherein two oxygen atoms (the oxygen atom is bonded to a silicon atom in another structural unit) and one bonding hand Is bonded to an oxygen atom bonded to a silicon atom in the other structural unit) and a silicon atom bonded to one R < ¹ >.

R ¹ represents an alkyl group having 1 to 3 carbon atoms and R ² represents an alkoxy group or a hydroxyl group having 1 or 2 carbon atoms.

[2]

The silicone resin composition according to claim 1, comprising the following first silicone resin as the silicone resin.

First silicone resin:

Containing silicon atom is at least one silicon atom selected from the group consisting of the A1 silicon atom and the A2 silicon atom and the A3 silicon atom, and the A1 silicon atom, the A2 silicon atom and the A3 silicon atom Wherein the ratio of the content of the A3 silicon atom to the total content of the A3 silicon atom is from 60 mol% to 90 mol%, and the weight average molecular weight is from 1,500 to 8,000.

[3]

The silicone resin composition according to claim 1 or 2, wherein the silicone resin comprises the following second silicone resin.

Second silicone resin:

Wherein the mass reduction rate when the temperature is raised from room temperature to 200 占 폚 at a temperature raising rate of 5 占 폚 / min and held (held) in air at 200 占 폚 for 5 hours is less than 5%.

[4]

A cured product of the silicone resin composition according to any one of [1] to [3].

[5]

A sealing material for a semiconductor light emitting device comprising a cured product of the silicone resin composition according to any one of [1] to [3].

According to the present invention, it is possible to provide a silicone resin composition useful in the production of a cured product of a silicone resin composition having high UV stability. Further, according to the present invention, a cured product of the silicone resin composition can be provided. Further, according to the present invention, it is possible to provide a sealing material for a semiconductor light emitting device comprising a cured product of the silicone resin composition.

[Silicone resin composition]

A description will be given of a silicone resin composition which is one embodiment of the present invention.

In the silicone resin composition of the present embodiment,

A silicone resin composition comprising at least one silicone resin,

(I) to (iii) above.

The requirements of (i) above shall be referred to as "requirements (i)", the requirements of (ii) above shall be called "requirements (ii)" and the requirements of (iii) above shall be called "requirements (iii)". Each of the requirements will be described below in order.

(Requirement (i))

As described above,

The A1 silicon atom is a silicon atom in the structural unit represented by the formula (A1) or a silicon atom in the structural unit represented by the formula (A1 ').

The A2 silicon atom is a silicon atom in the structural unit represented by the formula (A2).

The A3 silicon atom is a silicon atom in the structural unit represented by the formula (A3).

R ¹ represents an alkyl group having 1 to 3 carbon atoms, and R ² represents an alkoxy group or a hydroxyl group having 1 or 2 carbon atoms.

Formula (A1) R ^1, in the structural unit shown in the formula (A1 ') R ^1, in the structural unit shown in the formula (A2) R ^1, and expression of the structural unit represented by (A3 ) R ¹ in the structural unit shown by the, respectively, may be the same different.

R ^2, formula (A1 ') R ² is, identical to each of the structural units represented by R ^2, and the formula (A2) in the structural unit shown in the in the structural unit shown in the formula (A1) The chart may be different.

The two R ² in the structural unit represented by the formula (A1) may be the same or different. The two R ² in the structural unit represented by the formula (A1 ') may be the same or different.

In the silicone resin, the structural unit represented by the formula (A1) and the structural unit represented by the formula (A1 ') constitute the terminal of the organopolysiloxane chain. Further, the structural unit represented by the formula (A3) constitutes a branched chain structure by the organopolysiloxane chain. That is, the structural unit represented by the formula (A3) forms a part of a network structure or a ring structure in the silicone resin.

The silicon atom contained in the silicone resin composition of the present embodiment is substantially composed of at least one silicon atom selected from the group consisting of A1 silicon atom and A2 silicon atom and A3 silicon atom.

Here, "substantially composed of at least one silicon atom selected from the group consisting of A1 silicon atoms and A2 silicon atoms and A3 silicon atoms" means that at least 80 mol% of the silicon atoms contained in the silicone resin composition are A1 silicon atoms , A2 is a silicon atom and A3 silicon atom, and preferably 90 mol% or more is any of A1 silicon atom, A2 silicon atom and A3 silicon atom, and 95 mol% or more is A1 silicon atom, A2 More preferably a silicon atom or an A3 silicon atom.

In the silicone resin composition of the present embodiment, the ratio of the content of A3 silicon atoms to the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms is preferably from 60 mol% to 90 mol%, more preferably from 65 mol% Or more and 85 mol% or less.

(Requirement (ii))

As described above, the silicon atom contained in the silicone resin composition of the present embodiment is substantially composed of at least one silicon atom selected from the group consisting of A1 silicon atom and A2 silicon atom, and A3 silicon atom. As represented by the structural unit represented by the formula (A1), the structural unit represented by the formula (A1 '), the structural unit represented by the formula (A2), and the structural unit represented by the formula (A3) The side chain bonded to the atom is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a hydroxyl group.

In the silicone resin composition of the present embodiment, the molar ratio of the alkoxy groups in the side chain is preferably from 0.01 to less than 5, more preferably from 0.1 to less than 5, per 100 alkyl groups in the side chain.

When the molar ratio of the alkoxy groups in the side chain is higher than the above range (less than 5 per 100 alkyl groups), when the cured product of the silicone resin composition of the present embodiment is used as a sealing material for UV-LED, So that it can not be transmitted. When the molar ratio of the alkoxy groups in the side chain is lower than the above range (less than 5 per 100 alkyl groups), the viscosity of the silicone resin composition increases and the operability decreases.

The alkoxy group and the hydroxyl group bonded to the silicon atom are functional groups that generate a siloxane bond by a condensation reaction. The alkoxy group is more likely to absorb UV light than the hydroxyl group. Therefore, the cured product of the silicone resin composition in which the alkoxy group is contained more than the hydroxyl group is liable to react because the unreacted alkoxy group easily absorbs the UV light upon irradiation with the UV light. As a result, a cured product having a low UV stability is obtained.

On the other hand, the silicone resin composition of this embodiment contains more hydroxyl groups than alkoxy groups. Specifically, the molar ratio of side chains bonded to silicon in the silicone resin composition of the present embodiment is less than 5 for the alkyl group 100 and 10 or more for the alkyl group 100. Therefore, even when a functional group unreacted in the cured product of the silicone resin composition of the present embodiment is included, since most of the unreacted functional groups are hydroxyl groups, it is difficult to absorb UV light upon irradiation with UV light, It is difficult to do. As a result, a cured product having high UV stability is obtained.

The molar ratio of the side chain bonded to the silicon atom in the silicone resin composition of the present embodiment is preferably less than 30, more preferably less than 20, per 100 alkyl groups. When the molar ratio of the hydroxyl groups in the side chain is in the above range (less than 30 per 100 alkyl groups), volume shrinkage during curing of the silicone resin composition can be suppressed and coloring due to irradiation with UV light can be suppressed.

When an alkoxy group bonded to a silicon atom generates a siloxane bond by a condensation reaction, the alkoxy group is first converted into a hydroxyl group by reacting moisture with a silicon atom bonded to the alkoxy group. Next, an oxygen atom of a hydroxyl group bonded to the silicon atom reacts with another silicon atom to generate a siloxane bond. That is, in the alkoxy group and the hydroxyl group bonded to the silicon atom, since the hydroxyl group (silanol group) shows high reactivity, siloxane bonds are easily generated.

For this reason, the silicone resin composition of the present embodiment is prepared by mixing 600 ppm (mass per million) of a curing catalyst containing no metal (the curing catalyst is an acid catalyst or a base catalyst) as in the requirement (iii) But since the siloxane bond can be generated because the molar ratio of the side chain bonded to the silicon atom is in the above range, curing becomes possible.

The molar ratio of the alkoxy group to the alkyl group bonded to the silicon atom in the silicone resin composition of the present embodiment and the molar ratio of the hydroxyl group to the alkyl group can be appropriately combined as long as the above range is satisfied.

The silicone resin contained in the silicone resin composition of the present embodiment can be synthesized using an organosilicon compound having a functional group capable of generating a siloxane bond as a starting material, corresponding to each structural unit described above. Here, examples of the " functional group capable of generating a siloxane bond " include a halogen atom, a hydroxyl group, and an alkoxy group. Examples of the organic silicon compound corresponding to the structural unit represented by the formula (A3) include an organotin halosilane and an organotrialkoxysilane.

The silicone resin can be synthesized by reacting an organosilicon compound as a starting material with a hydrolysis and condensation method at a ratio corresponding to the proportion of each structural unit. By appropriately selecting an organosilicon compound as a starting material, the ratio of the presence of A3 silicon atoms contained in the silicone resin can be adjusted. The silicone resin thus synthesized is commercially available as a silicone resin or the like.

(Requirement (iii))

As described above, the silicone resin composition of the present embodiment contains a metal catalyst-free curing catalyst (the curing catalyst is an acid catalyst or a base catalyst) substantially containing no metal catalyst, The concentration of the curing catalyst in the silicone resin composition is 600 ppm (mass per million fraction) or less.

The concentration of the curing catalyst contained in the silicone resin composition of the present embodiment is preferably 300 ppm or less.

In general, a curing catalyst such as an acidic compound (acid catalyst), a basic compound (base catalyst), or a metal compound (metal catalyst) is sometimes added to the silicone resin composition. Examples of the metal catalyst include a catalyst containing a typical metal such as an aluminum compound such as aluminum acetylacetonate and a catalyst containing a transition metal such as platinum, ruthenium, tin, zirconium, zinc, cobalt, A transition metal which is an element present in the transition metal is known. Among them, metal catalysts containing aluminum, platinum or tin are particularly known.

On the other hand, the silicone resin composition of the present embodiment contains an acid catalyst or a base catalyst as a curing catalyst which does not substantially contain a metal catalyst and does not contain a metal. The concentration of the acid catalyst or the base catalyst contained in the silicone resin composition of the present embodiment is preferably 600 ppm or less, and more preferably 300 ppm or less.

In the silicone resin composition of the present embodiment, examples of the acid catalyst and the base catalyst include a Bronsted acid and a Bronsted base, and a Lewis acid and a Lewis acid, if the acid catalyst and the base catalyst promote the condensation reaction of an alkoxy group or a hydroxyl group bonded with a silicon atom. Lewis base.

In the silicone resin composition of the present embodiment, "substantially not containing" the metal catalyst means that the content of the metal catalyst in the silicone resin composition is 50 ppm (mass per million fraction) or less. The content of the metal catalyst in the silicone resin composition is preferably in the range of "not substantially containing" (less than 50 ppm (mass per million)) or less. The content of the metal catalyst in the silicone resin composition of the present embodiment is preferably 10 ppm or less, more preferably 5 ppm or less.

The silicone resin composition may contain a solvent for easy handling. However, when the curing catalyst is contained in the silicone resin composition, the curing of the silicone resin composition is promoted, so that the curing of the silicone resin composition may be completed in a state where the solvent contained in the silicone resin composition remains, The cured product of the resin composition sometimes contains a solvent. In such a case, the solvent may be altered by the irradiation of UV light, and the UV transmittance of the cured product of the silicone resin composition may be lowered, and the UV stability of the cured product of the silicone resin composition may be lowered.

On the other hand, in the silicone resin composition of the present embodiment, since the content of the acid catalyst or the base catalyst which is a curing catalyst containing no metal is very small, the solvent can be removed before the curing of the silicone resin composition is completed, The lowering of the transmittance of the UV light of the cured product of the silicone resin composition can be suppressed.

Further, the silicone resin composition of the present embodiment contains substantially no metal catalyst. Therefore, in the cured product of the silicone resin composition, the metal constituting the metal catalyst does not absorb UV light, and the transmittance of the UV light of the cured product of the silicone resin composition is hardly lowered. Therefore, the silicone resin composition of the present embodiment is useful for the production of a cured product of a silicone resin composition having high UV stability.

Next, the structure of the silicone resin composition of the present embodiment will be described in detail.

(First silicone resin)

The silicone resin composition of the present embodiment preferably contains the first silicone resin.

In the first silicone resin, the ratio of the content of A3 silicon atoms to the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms is preferably 70 mol% or more and 85 mol% or less.

In the silicone resin, the kind and abundance ratio of the functional group bonded to the silicon atom can be measured by, for example, nuclear magnetic resonance spectroscopy (NMR). Nuclear magnetic resonance spectroscopy (NMR) is described in detail in various literatures and the like, and dedicated measuring apparatuses are widely available. Specifically, after dissolving the silicone resin to be measured in a specific solvent, a strong magnetic field and a high frequency radio wave are given to hydrogen nuclei or silicon nuclei in the silicone resin, and the nuclear magnetic moment in the nucleus is resonated, The kind of the functional group and the abundance ratio can be measured. The method of measuring hydrogen nuclei is referred to as ¹ H-NMR and the method of measuring silicon nuclei is referred to as ²⁹ Si-NMR. Examples of the solvent used for the measurement of nuclear magnetic resonance spectroscopy (NMR) include heavy chloroform, heavy dimethylsulfoxide, heavy methanol, heavy acetone, heavy water and the like depending on the type of various functional groups in the silicone resin do.

The ratio of the content of the A3 silicon atom is determined by the area of the signal attributed as the A1 silicon atom obtained in the ²⁹ Si-NMR measurement, the area of the signal attributed as the A2 silicon atom, and the area of the signal attributed as the A3 silicon atom Can be obtained by dividing the area of the signal attributed as the A3 silicon atom by the total area.

In the structural unit contained in the first silicone resin,

R ¹ is preferably a methyl group.

When R ² is an alkoxy group, it is preferably a linear alkoxy group. The carbon number of the alkoxy group is preferably 1 to 2. Specifically, it is preferably a methoxy group or an ethoxy group.

The first silicone resin preferably has an organopolysiloxane structure represented by the following formula (1). In the formula (1), R ¹ and R ² have the same meanings as described above. p ¹ , q ¹ , a ¹ and b ¹ represent arbitrary integers.

In the organopolysiloxane structure represented by the formula (1), R ¹ is an alkyl group having 1 to 3 carbon atoms, and is preferably a methyl group. R ² is an alkoxy group having 1 or 2 carbon atoms or a hydroxyl group. When R ² is an alkoxy group, the alkoxy group is preferably a methoxy group or an ethoxy group.

The existence ratio of each structural unit in the organopolysiloxane structure represented by the formula (1) is such that the number of the A2 silicon atoms: x ¹ (= p ¹ + b ¹ x q ¹ ) and the number of the A3 silicon atoms: y ¹ = y ¹ / (x ¹ + y ¹ )) of the A 3 silicon atoms with respect to the total content of the silicon atoms (= a ¹ × q ¹ ) is in the range of 0.6 to 0.9. That is, the ratio of the content of A3 silicon atoms to the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms is 60 mol% to 90 mol%. The numerical values of p ¹ , q ¹ , a ¹ and b ¹ can be appropriately adjusted in such a range.

Since the first silicone resin has a high proportion of the A3 silicon atoms, the first silicone resin is cured to obtain a silicone-based resin cured product in which the organopolysiloxane chain is in the form of a network. When the proportion of the A3 silicon atom is higher than the above range (0.6 to 0.9), cracks easily occur in the silicone resin cured product, and when it is lower than the above range (0.6 to 0.9), the UV stability of the cured product of the silicone resin composition is low .

The first silicone resin is a silicone resin having an organopolysiloxane structure in which the ratio of the presence of A3 silicon atoms in the formula (1) is within the above range (0.6 to 0.9). Therefore, The cured product of water tends to have high UV stability. First in the silicone resin, the content of the silicon atoms A3 ^{(= y 1 / (x 1} + y 1)) is preferably within a range of 0.7 to 0.85.

The number of A2 silicon atoms and A3 silicon atoms per molecule of the first silicone resin can be adjusted by controlling the molecular weight of the resin having an organopolysiloxane structure represented by the formula (1). In the present embodiment, the sum of the number of A2 silicon atoms per molecule of the first silicone resin and the number of A3 silicon atoms is preferably 5 or more.

The first silicone resin has a weight average molecular weight (Mw) of 1,500 to 8,000. When the weight average molecular weight of the first silicone resin is too small, the UV stability of the cured product of the silicone resin composition of the present embodiment tends to be lowered. When the weight average molecular weight of the first silicone resin is within the above range, a cured product having better UV stability is obtained. The weight average molecular weight of the first silicone resin is more preferably 2,000 or more and 5,000 or less.

The weight average molecular weight (Mw) of the silicone resin can generally be a value measured by gel permeation chromatography (GPC). Specifically, the silicone resin is dissolved in a soluble solvent, and the resulting solution is passed through a column containing a filler containing a large number of pores (pores) together with a mobile phase solvent to obtain a polymer having a molecular weight And the content of the separated molecular weight components is detected using a differential refractive index meter, UV meter, viscometer, light scattering detector or the like as a detector. GPC-dedicated devices are widely available, and the weight average molecular weight (Mw) is generally measured in terms of standard polystyrene. The weight average molecular weight (Mw) in the present specification means that measured by this standard polystyrene conversion.

In the measurement of the weight average molecular weight by the GPC method, the solvent used for dissolving the silicone resin is preferably the same solvent as the mobile phase solvent used for the GPC measurement. Specific examples of the solvent include tetrahydrofuran, chloroform, toluene, xylene, dichloromethane, dichloroethane, methanol, ethanol, isopropyl alcohol and the like. Columns used for GPC measurement are commercially available, and an appropriate column may be used depending on the assumed weight average molecular weight.

The first silicone resin can be synthesized using an organosilicon compound having a functional group capable of generating a siloxane bond as a starting material, corresponding to each structural unit constituting the first silicone resin. Here, the "functional group capable of generating a siloxane bond" has the same meaning as described above. Examples of the organic silicon compound corresponding to the structural unit represented by the formula (A3) include an organotin halosilane and an organotrialkoxysilane. The first silicone resin can be synthesized by reacting such an organosilicon compound as a starting material with a hydrolysis and condensation method at a ratio corresponding to the presence ratio of each structural unit. The silicone resin thus synthesized is commercially available as a silicone resin or the like.

(Second silicone resin)

The silicone resin composition of the present embodiment preferably contains a second silicone resin of steam and more preferably contains the first silicone resin and the second silicone resin. The second silicone resin is a silicone resin having a mass reduction rate of less than 5% when heated from room temperature to 200 DEG C at a temperature raising rate of 5 DEG C / min and held in air at 200 DEG C for 5 hours. Here, the step of raising the temperature from room temperature to 200 占 폚 at a heating rate of 5 占 폚 / min is usually performed in air.

The second silicone resin has less unreacted functional groups and is thermally stable. Therefore, in the cured product of the silicone resin composition containing the second silicone resin, the second silicone resin functions as a filler. Therefore, the second silicone resin contributes to the improvement of the mechanical strength of the cured product of the silicone resin composition.

In addition, the second silicone resin has a small number of unreacted functional groups and is hardly deteriorated even when irradiated with UV light. Therefore, by blending the second silicone resin, the UV stability of the cured product of the silicone resin composition can be further improved.

The second silicone resin is not particularly limited as long as it is thermally stable, and specifically, a silicone resin having a fine particle structure called a silicone rubber powder or a silicone resin powder can be used.

Of the silicone resin having a fine particle structure, a spherical silicone resin powder composed of a polysilsesquioxane resin having a three-dimensional network structure in which a siloxane bond is represented by (RSiO _3/2 ) is preferable. (RSiO _3/2 ), R is preferably a methyl group.

When the second silicone resin is a spherical silicone resin powder, the average particle diameter of the silicone resin powder is preferably from 0.1 to 50 μm, more preferably from 1 to 30 μm, more preferably from 2 to 20 μm desirable.

If the average particle diameter of the silicone resin powder is within the above range (0.1 탆 or more and 50 탆 or less), peeling of the cured product of the silicone resin composition at the interface with the substrate, clouding of the cured product of the silicone resin composition, The lowering of the light transmittance of the cured product of the cured product tends to be suppressed.

The average particle diameter of the silicone resin powder can be measured by, for example, a particle size distribution measuring apparatus using the "laser diffraction / scattering method" as a measurement principle. This method is a method of measuring the particle diameter distribution of particles by using diffraction light and scattering light generated in various directions depending on the size of the particles when a laser beam (monochromatic light) is irradiated to the particles, And the distribution state of scattered light. A device using the "laser diffraction / scattering method" as a measurement principle is commercially available from many manufacturers.

As the second silicone resin, a commercially available product can be used. For example, KMP-710, KMP-590, X-52-854 and X-52-1621 (manufactured by Shin-Etsu Chemical Co., Ltd.), Tospel 120, Tospel 130, Tospel 145, Tospearl 2000B, And MSP-N050, MSP-N080 and MSP-S110 (manufactured by Nikkorika Kogyo Co., Ltd.) can be used.

When the silicone resin composition of the present embodiment is a silicone resin composition liquid containing a first silicone resin, a second silicone resin and a solvent for dissolving or dispersing these silicone resins, the first silicone resin , The second silicone resin and the solvent is preferably 80 mass% or more, and more preferably 90 mass% or more.

(Content of resin component) of the content of the second silicone resin relative to the total content of the first silicone resin and the second silicone resin is preferably 20 mass% or more and 90 mass% or less, more preferably 40 mass% or more and 80 mass% or less More preferable. When the content ratio of the second silicone resin to the resin is within the above range, there is a tendency to obtain a cured product of the silicone resin composition having excellent balance resistance against crack resistance and UV stability.

In the present specification, "crack resistance" means that the cured product of the silicone resin composition is hardly cracked. In addition, a sealant using a cured product of a silicone resin composition that is hardly cracked may be sometimes indicated as " crack resistance is high ".

Cracks in the cured product of the silicone resin composition are caused by volumetric shrinkage at the time of curing of the silicone resin composition, heat shock generated when the cured product is suddenly exposed to a high temperature environment from a low temperature environment, And deterioration of the cured product due to heat. When the silicone resin composition of the present embodiment contains the second silicone resin, all cracks caused by the above-described causes can be suppressed.

(menstruum)

The silicone resin composition of the present embodiment may contain a solvent in order to facilitate handling.

As the solvent, an organic solvent having a boiling point of 100 ° C or higher at normal pressure is preferable. Since an organic solvent having a boiling point of less than 100 占 폚 is liable to evaporate, the concentration of the silicone resin composition is liable to fluctuate and handling of the silicone resin composition tends to be difficult. On the other hand, in a silicone resin composition containing an organic solvent having a boiling point of 100 ° C or higher, such a problem tends to be suppressed.

As the organic solvent, specifically,

Esters such as 2-ethoxyethyl acetate (boiling point: 156 占 폚); Ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoethylhexyl ether, ethylene glycol monophenyl ether, Diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monoethylhexyl ether, diethylene glycol monophenyl ether , Diethylene glycol monobenzyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, propylene glycol monohexyl ether, propylene glycol monoethylhexyl ether, Propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monohexyl ether, dipropylene glycol Glycol ether solvents such as monoethylhexyl ether, dipropylene glycol monophenyl ether and dipropylene glycol monobenzyl ether; Ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monohexyl ether acetate, ethylene glycol monoethylhexyl ether acetate, ethylene glycol monophenyl ether acetate, ethylene glycol monobenzyl ether acetate And the like (those obtained by adding an acetic acid group to the glycol ether solvent described above).

(Other additives)

The silicone resin composition of the present embodiment may contain a silane coupling agent and other additives.

&Quot; Silane coupling agent "

The silane coupling agent has the effect of improving the adhesion between the cured product of the silicone resin composition and the semiconductor light emitting element or the substrate. As the silane coupling agent, a silane coupling agent having at least one or more groups selected from the group consisting of a vinyl group, an epoxy group, a styryl group, a methacrylic group, an acrylic group, an amino group, a ureido group, a mercapto group, a sulfide group and an isocyanate group And a silane coupling agent having an epoxy group or a mercapto group is more preferable.

Specific examples of the silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- Glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like.

When the silane coupling agent is contained in the silicone resin composition of the present embodiment, the silicon atoms contained in the silane coupling agent are also detected as a ²⁹ Si-NMR signal. Therefore, in the present specification, in calculating the signal area (the signal area attributed as A1 silicon atom, the signal area attributed as A2 silicon atom, and the signal area attributed as A3 silicon atom) of the silicone resin composition, Signals shall also be included.

The content of the silane coupling agent in the silicone resin composition of the present embodiment is, for example, about 100 parts by mass of the first silicone resin or about 100 parts by mass of the total content of the first silicone resin and the second silicone resin , Preferably 0.0001 mass part or more and 1.0 mass part or less, and more preferably 0.001 mass part or more and 0.1 mass part or less. If the content of the silane coupling agent is higher than the above range, the silane coupling agent itself absorbs light, which may lower the transparency of the cured product of the silicone resin composition.

The silane coupling agent may be mixed with the silicone resin composition of the present embodiment. In addition, a silane coupling agent may be previously attached to the surface of the semiconductor light emitting element or the substrate by coating or immersion treatment, and then the silicone resin composition of the present embodiment may be formed by potting or the like and then cured.

"Other additives"

Other additives include silicone resins, silicone oligomers, silicone compounds and the like, which are different from the first silicone resin and the second silicone resin. Specific examples of other additives include general commercially available silicon compounds for modification. When the silicone resin composition of the present embodiment contains the silicone compound for modification, flexibility can be imparted to the cured product of the silicone resin composition. Examples of the modifying silicone compound include polymers and oligomers having a dialkylsiloxane structure having R ₂ SiO _2/2 (wherein R represents an alkyl group) as a main chain.

When containing the silicon compound in the silicone resin composition of the present embodiment, is detected as a signal of ²⁹ Si-NMR is also a silicon atom contained in the silicone compound. Therefore, in the present specification, when calculating the signal area (signal area attributed as A1 silicon atom, signal area attributed as A2 silicon atom, and signal area attributed as A3 silicon atom) of the silicone resin composition, .

The content of the silicone compound in the silicone resin composition of the present embodiment is preferably 0.1 to 100 parts by mass based on 100 parts by mass of the first silicone resin or 100 parts by mass of the total content of the first silicone resin and the second silicone resin. Not less than 20 parts by mass, and more preferably not less than 0.5 parts by mass and not more than 10 parts by mass. If the content of the silicone compound is higher than the above range, the transparency of the cured product of the silicone resin composition may be impaired.

Other examples of the above-mentioned additives include a defoaming agent for suppressing bubbles generated during mixing of the silicone resin composition.

The silicone resin composition of the present embodiment can be obtained by mixing the above-mentioned silicone resin, organic solvent and the like by a commonly known method.

[Cured product of silicone resin composition]

A cured product of a silicone resin composition which is one embodiment of the present invention will be described.

By curing the silicone resin composition of the present embodiment at, for example, 120 deg. C or higher and 200 deg. C or lower, a cured product of the silicone resin composition (hereinafter also referred to as " cured product of the present embodiment ") can be obtained. The curing time is preferably from 1 hour to 100 hours, more preferably from 5 hours to 70 hours, further preferably from 5 hours to 50 hours.

The cured product of the present embodiment can be obtained by, for example, curing the silicone resin composition of the present embodiment at 160 DEG C for 10 hours. The cured product thus obtained has a Shore hardness of about D70 as measured, for example, according to JIS K6253-3: 2012.

The cured product of the present embodiment is useful as a sealing material for a semiconductor light emitting device (LED), a photodiode, a CCD, and a CMOS, because it is excellent in UV stability, and is particularly useful as a sealing material for UV-LEDs emitting UV light.

As described above, the silicone resin composition of the present embodiment is useful for the production of a cured product of a silicone resin composition having high UV stability.

[Seal material for semiconductor light emitting device]

A sealing material for a semiconductor light emitting element according to an embodiment of the present invention will be described.

Since the sealing material for a semiconductor light emitting element of the present embodiment is made of a cured product of the silicone resin composition of the present embodiment, it becomes a sealing material for a semiconductor light emitting element having high UV stability.

(Example)

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

In the present embodiment, as a means for measuring the kind of the silicon atom and the ratio of the substituent in the silicone resin composition, it is preferable to use solution ¹ H-NMR, solution ²⁹ Si-NMR or solid ²⁹ Si-NMR Respectively. The molecular weight of the silicone resin was measured by the GPC method. Conditions for each measurement method are as follows.

≪ Solution ¹ H-NMR Measurement Conditions >

Device name: ECA-500 made by JEOL RESONANCE

Observation nucleus: ¹ H

Observation frequency: 500.16MHz

Measuring temperature: room temperature

Measurement solvent: DMSO-d6

Pulse width: 6.60 mu sec (45 DEG)

Pulse repetition time: 7.0 sec

Accumulated count: 16

Sample concentration (sample / measurement solvent): 300 mg / 0.6 ml

<Solution ²⁹ Si-NMR measurement conditions>

Device name: 400-MR manufactured by Agilent

Observation nucleus: ²⁹ Si

Observed frequency: 79.42MHz

Measuring temperature: room temperature

Measurement solvent: CDCl ₃

Pulse width: 8.40 mu sec (45 DEG)

Pulse repetition time: 15.0 sec

Accumulated count: 4000 times

Sample concentration (sample / measurement solvent): 300 mg / 0.6 ml

<Solid state ²⁹ Si-NMR measurement method>

Device name: AVANCE300 400-MR made by Bruker

Observation nucleus: ²⁹ Si

Observation frequency: 59.6MHz

Measuring temperature: room temperature

Measuring method: DDMAS method

Reference substance: hexamethylcyclotrisiloxane

(Set to -9.66ppm, equivalent to TSM 0ppm setting)

MAS condition: 3.5 kHz

Pulse width: π / 6 (1.4 ms)

Standby time: 20.0sec

Accumulated count: 4096

Sample volume: 180 mg

&Lt; GPC measurement condition >

Apparatus: Tosoh Corporation HLC-8220

Column: TSKgel Multipore HXL-M x 3 + Guard column-MP (XL)

Flow rate: 1.0 mL / min

Detection condition: RI (polarity +)

Concentration: 100 mg + 5 mL (THF)

Injection amount: 100 μL

Column temperature: 40 DEG C

Eluent: THF

In the present embodiment, the molar ratio of the methyl group, the methoxy group and the hydroxyl group, which is bonded to the silicon atom present in the silicone resin composition, was determined by solution ¹ H-NMR or solid ¹³ C-NMR measurement. Conditions for each measurement method are as follows.

In the present embodiment, when the object to be measured (silicone resin composition) contains a silicone resin which is not soluble in the measurement solvent, the amount of the methyl group, methoxy group and hydroxyl group present in the measurement object The molar ratio is measured.

First, the silicone resin composition is subjected to centrifugal separation or filtration to separate the silicone resin dissolved in the measurement solvent and the silicone resin not dissolved in the measurement solvent. Thereafter, solution NMR measurement is performed on the silicone resin dissolved in the measurement solvent, and solid NMR measurement is performed on the silicone resin which is not dissolved in the measurement solvent, whereby the molar ratio of the methyl group, methoxy group and hydroxyl group bonded to the silicon atom is measured do. Thereafter, the molar ratio of the methyl group, the methoxy group and the hydroxyl group present in the silicone resin composition can be obtained by summing the measured values respectively.

Further, instead of separating the silicone resin contained in the silicone resin composition, the molar ratio of the methyl group, the methoxy group and the hydroxyl group bonded to the silicon atom is measured for a silicon resin as a raw material of the silicone resin composition, The molar ratio of the methyl group, the methoxy group and the hydroxyl group present in the silicone resin composition may be determined based on the compounding ratio of the silicone resin contained in the resin composition.

At this time, in the obtained NMR spectrum, peaks derived from alkoxy groups such as methoxy groups were detected during chemical shifts of 3.0 ppm to 4.0 ppm, but peaks derived from the structure of the solvent component and peaks of the silanol groups and the like were similar chemical shifts So that a plurality of peaks may overlap each other. In this case, a process of obtaining a spectrum difference between the obtained NMR spectrum and the solvent-only NMR spectrum, and a process of separating the alkoxy group from the silanol group peak by changing the measurement environment temperature may be performed. By performing such a treatment, the molar ratio of the methoxy group alone can be obtained.

&Lt; Solution ¹ H-NMR Measurement Conditions >

Device name: 400-MR manufactured by Agilent

Observation nucleus: ¹ H

Observation frequency: 399.78MHz

Measurement temperature: Described in Examples and Comparative Examples

Measurement solvent: Described in Examples and Comparative Examples

Pulse width: 6.00 mu sec (45 DEG)

Pulse repetition time: 30.0 sec

Accumulated count: 16

Sample concentration (sample / measurement solvent): 100 mg / 0.8 ml

<Conditions for measuring solid ¹³ C-NMR>

Device name: AVANCE300 400-MR made by Bruker

Observation nucleus: ¹³ C

Observation frequency: 75.4MHz

Measuring temperature: room temperature

Measuring method: DDMAS method

Reference substance: adamantane (set at 29.47 ppm, equivalent to TMS 0 ppm setting)

MAS condition: 10 kHz

Pulse width: π / 6 (1.5 ms)

Standby time: 10.0sec

Accumulated count: 8192 times (measurement of reference)

16384 times (= 2 ¹⁴ times) (Measurement of Resin (C)) [

Sample volume: 85 mg

In this example, the UV transmittance immediately after curing of the cured product of the silicone resin composition and the UV transmittance of the cured product of the silicone resin composition after the UV irradiation test were respectively measured. The conditions of UV transmittance measurement are as follows.

The UV irradiation test of the cured product of the silicone resin composition was carried out while heating the cured product of the silicone resin composition on a hot plate. The conditions of the UV irradiation test are as follows.

Based on these measurement results, the UV stability of the cured product of the silicone resin composition was evaluated.

<Measurement of transmittance>

Device name: UV-3600 made by Shimazu Corporation

Attachment: Integral sphere ISR-3100

Measured wavelength: 220 to 800 nm

Background measurement: wait

Measuring speed: medium speed

<UV irradiation test>

Device name: Wuxi morning article SP9-250DV

UV irradiation wavelength: 254 nm to 420 nm

UV irradiation intensity: 150 mW / cm ²

Resin heating temperature: 50 캜 (according to hot plate)

UV irradiation time: 300 hours

(Example 1)

As the first silicone resin, a silicone resin 1 having an organopolysiloxane structure represented by the formula (1) (Mw = 3500, in the formula (1), R ¹ = methyl group, R ² = methoxy group or hydroxyl group) Respectively. The abundance ratio of each structural unit of the silicone resin 1 is shown in Table 1.

When the silicone resin 1 was heated from room temperature to 200 ° C at a temperature raising rate of 5 ° C / minute and held at 200 ° C for 5 hours in the air, the mass reduction rate was 10.3%.

As the second silicone resin, MSP-S110 (manufactured by Nikkorika Co., Ltd.) was used. MSP-S110 was raised from room temperature to 200 占 폚 at a temperature raising rate of 5 占 폚 / minute, and the mass reduction rate when kept at 200 占 폚 for 5 hours in air was 3.5%. The presence ratio of each structural unit of MSP-S110 is shown in Table 2.

35.04 g of silicone resin 1, 23.36 g of MSP-S110 as the second silicone resin, and 21.60 g of 2-ethoxyethyl acetate were mixed to obtain a silicone resin composition.

In the obtained silicone resin composition, the ratio of the content of A3 silicon atoms to the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms was 72%.

In the obtained silicone resin composition, the molar ratio of the hydroxyl group (silanol group) bonded to the silicon atom relative to 100 of the methyl group (alkyl group) bonded to the silicon atom was measured, and the ratio of the methyl group (alkyl group) The mole ratio of the methoxy group (alkoxy group) bonded to the atom was measured.

The measurement temperature in the ¹ H-NMR measurement at that time was room temperature and the measurement solvent was DMSO-d ₆ .

The measurement results are shown in Table 3 below.

A curing catalyst containing 15% phosphoric acid was added to 100 parts by mass of the obtained silicone resin composition, and the mixture was stirred sufficiently to obtain a silicone resin composition of Example 1. The silicone resin composition of Example 1 was cured in an aluminum cup under a curing condition of keeping at 160 캜 for 10 hours to obtain a cured product having a thickness of 1 mm. The resulting cured product had no stickiness (tackiness). No cracks were observed in the obtained cured product.

The addition amount of the curing catalyst is shown in Table 3 to be described later.

The UV transmittance of the resulting cured product was measured. Thereafter, the obtained cured product was subjected to a UV irradiation test, and the UV transmittance of the cured product after the UV irradiation test was measured.

From the measured values of the UV transmittance before and after the UV irradiation test, the retention of the UV transmittance was determined based on the following formula. The calculated retention ratio is used as an index of UV stability of the silicone resin cured product.

(Retention rate of UV transmittance) = (B / A) x 100

A: UV transmittance of the cured product of the silicone resin composition before UV irradiation test

B: UV transmittance of the cured product of the silicone resin composition after the UV irradiation test

The UV transmittance before and after the UV irradiation test and the retention rate of the UV transmittance are shown in Table 3 described later.

(Example 2)

The silicone resin composition of Example 2 and the silicone resin of Example 2 were obtained in the same manner as in Example 1 except that the amount of the curing catalyst of the silicone resin composition of Example 1 was changed to that shown in Table 3 to be described later A cured product of the composition was obtained.

The cured product of the obtained silicone resin composition was measured for UV transmittance before and after the UV irradiation test and retention of the UV transmittance in the same manner as in Example 1.

The measurement results are shown in Table 3 below.

(Comparative Example 1)

The silicone resin composition of Comparative Example 1 and the silicone resin of Comparative Example 1 were prepared in the same manner as in Example 1 except that the amount of the curing catalyst of the silicone resin composition of Example 1 was changed to that shown in Table 3 described later A cured product of the composition was obtained.

The cured product of the obtained silicone resin composition was measured for UV transmittance before and after the UV irradiation test and retention of the UV transmittance in the same manner as in Example 1.

The measurement results are shown in Table 3 below.

(Comparative Example 2)

A mixture of 0.75 mol of ethyltrimethoxysilane and dilute acid as an acid catalyst was used to make a molar ratio of trifunctional silicon alkoxide: water: nitric acid to 1: 3: 0.002. The obtained mixture was stirred in a sealed container at 20 占 폚 for 3 hours and then left at 60 占 폚 for 24 hours to carry out hydrolytic polycondensation. The obtained reaction solution was separated into a lower layer containing a large amount of the condensation polymerization reaction liquid and an upper layer containing a large amount of methanol as a by-product, so that the lower reaction solution was taken out by a separating funnel.

The obtained lower layer side reaction liquid was dried in air at 60 占 폚 for 2 hours and then dried under vacuum at 40 占 폚 for 2 hours to obtain a silicone resin composition of Comparative Example 2.

The silicone resin composition of Comparative Example 2 had a content of A3 silicon atoms of 58.7% based on the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms.

The nitric acid concentration in the silicone resin composition of Comparative Example 2 was 128 ppm.

In the silicone resin composition of Comparative Example 2, the molar ratio of the hydroxyl group (silanol group) bonded to the silicon atom to 100 of the methyl group (alkyl group) bonded to the silicon atom was measured, and the ratio of the methyl group (alkyl group) The molar ratio of the methoxy group (alkoxy group) bonded to the silicon atom was measured.

The ¹ H-NMR measurement at that time was 60 ° C, and the measurement solvent was DMSO-d ₆ .

The measurement results are shown in Table 4 below.

A cured product was obtained in the same manner as in Example 1 except that the silicone resin composition of Comparative Example 2 was cured at 160 占 폚 for 24 hours.

The UV transmittance of the obtained cured product was measured in the same manner as in Example 1. As a result, the obtained cured product had a transmittance of UV light having a wavelength of 280 nm of 72%, which was insufficient for use as a sealing material for UV-LED. Thereafter, the obtained cured product was subjected to a UV irradiation test, and the transmittance of the cured product after the UV irradiation test was measured. As a result, the retention ratio of the UV transmittance was 55%, which was greatly reduced from the transmittance of UV light before the UV irradiation test.

(Comparative Example 3)

354 g of the silicone resin 1 was added to 190 g of isopropyl alcohol and the mixture was heated and stirred until the internal temperature reached 85 캜 to dissolve the silicone resin 1. Thereafter, 35 g of an oligomer having an organopolysiloxane structure represented by the following formula (2) was added thereto.

(Wherein,

R ¹ and R ² have the same meanings as described above.

^{p 2, q 2, r 2} , a 2 and b ^{2 are, [a 2 × q 2]} / [(p 2 + b 2 × q 2) + a 2 × q 2 + (r 2 + q 2)] = 0 to 0.3).

The presence ratio of each structural unit of the above oligomer is shown in Table 3.

Thereafter, 3.8 g of a commercially available silicone compound different from the silicone resin 1 and the oligomer was added and dissolved by stirring for 1 hour or more. The commercially available silicone compound has a ratio of the content of A3 silicon atoms to the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms of 0% or more and less than 30%, and has a weight average molecular weight of more than 8,000, Lt; / RTI &gt;

Then, 123 g of 2-ethoxyethyl acetate and 0.1 g of 3-glycidoxypropyltrimethoxysilane (silane coupling agent) were added to the obtained mixture. From the obtained mixture, isopropyl alcohol was distilled off under a condition of a temperature of 70 DEG C and a pressure of 4 kPaA until the isopropyl alcohol concentration became 1 mass% or less by using an expander, A silicone resin composition was obtained in which the mixing ratio of the oligomer and the commercially available silicone compound was 90: 9: 1.

As a result of ²⁹ Si-NMR measurement of the obtained silicone resin composition, the area of the signal derived from the A3 silicon atom in the entire silicon-derived signal was 65%.

In the obtained silicone resin composition, the molar ratio of the hydroxyl group (silanol group) bonded to the silicon atom relative to 100 of the methyl group (alkyl group) bonded to the silicon atom was measured, and the ratio of the methyl group (alkyl group) The mole ratio of the methoxy group (alkoxy group) bonded to the atom was measured. As a result, the molar ratio of the hydroxyl group was 23.1 and the molar ratio of the methoxy group was 16.1.

The ¹ H-NMR measurement at that time was 60 ° C, and the measurement solvent was DMSO-d ₆ .

2 parts by mass of a curing catalyst containing 15% phosphoric acid was added to 100 parts by mass of the obtained silicone resin composition and sufficiently stirred to obtain a silicone resin composition of Comparative Example 3. The phosphoric acid concentration in the silicone resin composition of Comparative Example 3 was 2870 ppm. About 5 g of the silicone resin composition of Comparative Example 3 was put in an aluminum cup and the temperature was raised from room temperature to 160 캜 at a rate of 5 캜 / minute in an oven and left at 160 캜 for 3 hours to obtain a cured product having a thickness of 1 mm . The resulting cured product had no tackiness (tackiness). Also, cracks were not observed in the cured product.

The cured silicone resin thus obtained was measured for UV transmittance before and after the UV irradiation test and retention of the UV transmittance in the same manner as in Example 1. As a result, the UV transmittance before the UV irradiation test was 80%, and the retention rate of the UV transmittance was 45%.

In Table 4, "UV transmittance of the silicone resin cured product before UV irradiation test" is shown as "initial UV transmittance". The initial UV transmittance is determined to be at least 75%, and the determination is indicated by &quot;? &Quot;. In addition, those having an initial UV transmittance of less than 75% were rejected and indicated by "X" in the determination column.

In the following Table 4, it is accepted that the "retention ratio of the UV transmittance" is 90% or more, and the judgment column shows "○". The case where the "retention ratio of the UV transmittance" is less than 90% is rejected, and the judgment column shows "x".

From the above results, it was found that the silicone resin composition of the present invention is useful.

(Industrial availability)

According to the present invention, it is possible to provide a silicone resin composition useful in the production of a cured product of a silicone resin composition having high UV stability. Further, according to the present invention, a cured product of the silicone resin composition can be provided. Further, according to the present invention, it is possible to provide a sealing material for a semiconductor light emitting device comprising a cured product of the silicone resin composition.

Claims (5)

A silicone resin composition comprising at least one silicone resin,
Wherein the silicone resin composition satisfies the following requirements (i) - (iii).
(I) at least one silicon atom selected from the group consisting of A1 silicon atoms and A2 silicon atoms, and A3 silicon atoms, and the total content of A1 silicon atoms, A2 silicon atoms and A3 silicon atoms , The ratio of the content of A3 silicon atoms is 50 mol% or more and 99 mol% or less.
(Ii) the side chain bonded to the silicon atom is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a hydroxyl group, the molar ratio of the alkoxy group is less than 5 per 100 alkyl groups, 100 or more.
(Iii) a curing catalyst which contains substantially no metal catalyst and which does not contain a metal (the curing catalyst is an acid catalyst or a base catalyst), and the catalyst for curing The concentration is 600 ppm (mass per million) or less.
[here,
The A1 silicon atom is a structural unit represented by the following formula (A1) wherein one oxygen atom (the oxygen atom is bonded to a silicon atom in another structural unit), one R ¹ and two R ² Or a structural unit represented by the following formula (A1 '), one bonding hand (the bonding hand is bonded to an oxygen atom bonding with a silicon atom in another structural unit), or a structural unit represented by the following formula Is a silicon atom bonded to one R &lt; ^{1 &gt;} and two R &lt; ² &gt;
The A2 silicon atom is a structural unit represented by the following formula (A2), wherein one oxygen atom (the oxygen atom is bonded to the silicon atom in the other structural unit) and one bonding hand Is bonded to an oxygen atom bonded to a silicon atom in another structural unit), and is a silicon atom bonded to one R ¹ and one R ² .
The A3 silicon atom is a structural unit represented by the following formula (A3) wherein two oxygen atoms (the oxygen atom is bonded to a silicon atom in another structural unit) and one bonding hand Is bonded to an oxygen atom bonded to a silicon atom in the other structural unit) and a silicon atom bonded to one R &lt; ¹ &gt;.
R ¹ represents an alkyl group having 1 to 3 carbon atoms and R ² represents an alkoxy group or a hydroxyl group having 1 or 2 carbon atoms.

The method according to claim 1,
A silicone resin composition comprising the following first silicone resin as the silicone resin.
First silicone resin:
Containing silicon atom is at least one silicon atom selected from the group consisting of the A1 silicon atom and the A2 silicon atom and the A3 silicon atom, and the A1 silicon atom, the A2 silicon atom and the A3 silicon atom Wherein the ratio of the content of the A3 silicon atom to the total content of the A3 silicone atom is from 60 mol% to 90 mol%, and the weight average molecular weight is from 1,500 to 8,000. 3. The method according to claim 1 or 2,
Wherein the silicone resin comprises the following second silicone resin.
Second silicone resin:
Wherein the silicone resin is heated from room temperature to 200 占 폚 at a temperature raising rate of 5 占 폚 / min, and the mass reduction rate when held at 200 占 폚 in the air for 5 hours is less than 5%. A cured product of the silicone resin composition according to any one of claims 1 to 3. A sealing material for a semiconductor light emitting device comprising a cured product of the silicone resin composition according to any one of claims 1 to 3.