JP2017008297A - Curable resin composition, optical element and optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable resin composition extremely high in transparency, ultraviolet resistance and heat resistance in an ultraviolet region and capable of suppressing generation of crack, peeling or coloring and capable of suppressing curing shrinkage even used for encapsulation of ultraviolet LED applying high power.SOLUTION: There is provided a curable resin composition containing an alkoxy oligomer having a specific structure of a liquid at a room temperature of 20 to 85 mass% and silicone resin which is a solid at room temperature of 15 to 80 mass% and containing phosphoric acid as a curing catalyst of 0.1 to 20 pts.mass based on 100 pts.mass of total amount of the alkoxy oligomer and the silicone resin.SELECTED DRAWING: None

Description

  The present invention relates to a curable resin composition having high light transmittance in the ultraviolet wavelength region and having high ultraviolet resistance and high heat resistance, an optical element and an optical semiconductor device comprising a cured product of the curable resin composition ( For example, it relates to an ultraviolet LED (Light Emitting Diode).

  In recent years, LEDs that emit light having a short wavelength, such as blue LEDs and ultraviolet LEDs, have been developed and put into practical use. Such LEDs can be used, for example, in general lighting applications where fluorescent lamps and incandescent lamps have been used in the past, as well as UV curable resins and UV curable inks that have conventionally used short arc lamps. The use of curing light sources is rapidly expanding.

  Generally, an LED has an LED die having an anode electrode and a cathode electrode formed on the surface thereof. The anode electrode and the cathode electrode are respectively wire bonded to the external electrode, and the LED die emits light when the external electrode is energized.

  In the LED having such a configuration, if the LED die and the ultrafine wire (for example, 30 μm in diameter) are exposed to the external space, the LED die may be damaged or the wire may be disconnected. Is generally used after being sealed with a sealing material (for example, resin).

  In addition, when the LED is sealed with a sealing material having a higher refractive index than air, the difference in refractive index is reduced at the interface between the LED die and the sealing material. This is also effective in improving the extraction efficiency.

  As such a sealing material, conventionally, in an LED emitting visible light, a highly transparent epoxy resin (Epoxy resin), a silicone resin (Silicone resin) or the like has been used (for example, Patent Document 1, Patent Document 2). However, when an epoxy resin or a silicone resin that has been conventionally used is used for an LED that emits light having a short wavelength, the resin itself deteriorates due to the light having a short wavelength, and problems such as coloring and cracks occur. . And the problem of this sealing material becomes remarkable especially in ultraviolet LED which emits a strong ultraviolet-ray and is used for the curing light source of ultraviolet curing resin or ultraviolet curing ink.

As an ultraviolet LED used as a light source for curing ultraviolet curable resin or ultraviolet curable ink, for example, an LED that supplies 3 W power to a 1 mm square LED die and emits ultraviolet light having a wavelength of 365 nm and 1 W is used. In this case, the irradiation light quantity is 1 W / mm ² , which corresponds to 30,000 to 50,000 times the ultraviolet light quantity contained in sunlight. For this reason, UV LED encapsulants for UV curable resins and UV curable ink curing light sources are required to have strong UV resistance in addition to high transparency in the emission wavelength range of UV LEDs.

  In addition, 2W of the 3W electric power supplied to the ultraviolet LED is converted into thermal energy, and the LED die itself becomes a high temperature. Therefore, an ultraviolet LED sealing for a light source for curing ultraviolet curable resin or ultraviolet curable ink is used. In addition to UV resistance, the material is required to have resistance to heat (temperature).

  As such a sealing material for LEDs and the like having ultraviolet resistance and heat resistance, for example, it has been proposed to use a composition containing an epoxy group-containing polyfunctional polysiloxane and a metal chelate compound (Patent Literature). 3).

JP 2003-176334 A JP 2003-277473 A JP 2010-059359 A

  However, the composition described in Patent Document 3 is a product that is cured by an epoxy group ring-opening polymerization reaction. However, since it contains a metal chelate compound that has strong absorption in the ultraviolet region, the composition of an ultraviolet LED that applies high power is sealed. In stopping applications, transparency in the ultraviolet region, ultraviolet resistance, and heat resistance were not sufficient.

  The ultraviolet LED also has an optical element such as a lens in addition to the ultraviolet LED that is a light emitting portion, and the optical element has sufficiently high transparency, ultraviolet resistance, and heat resistance in the ultraviolet region. Is now required.

  The present invention has been made in view of the above circumstances, and in comparison with conventional curable resin compositions, transparency in the ultraviolet region, ultraviolet resistance and heat resistance are extremely high, and high power is applied. Providing a curable resin composition capable of suppressing the occurrence of cracking, peeling, and coloring and suppressing curing shrinkage even when used for sealing an ultraviolet LED or optical element material, and this curable resin composition It is an object of the present invention to provide an optical element and an optical semiconductor device made of the cured product.

  In order to achieve the above-mentioned object, the present inventor has required transparency, ultraviolet resistance, heat resistance, moldability in the required ultraviolet region for a curable resin composition suitable for sealing an ultraviolet LED to which a large amount of power is applied. From the point of view, we have been studying raw materials. As a result, in order to impart stress relaxation capability, by using a silicone resin as a material having a non-reactive functional group and having a high solid content concentration, and further increasing the solid content concentration, It has been found that an optimal curable resin composition can be obtained. The present invention has been accomplished by these findings.

That is, the present invention
(I) 20 to 85% by mass of an alkoxy oligomer that is liquid at room temperature and 15 to 80% by mass of a silicone resin that is solid at room temperature,
The alkoxy oligomer has an organopolysiloxane structure,
The following general formula (1)
(R ¹ R ² R ³ SiO _1/2 ) (1)
(Wherein R ¹ , R ² and R ³ are each independently the same or different organic groups),
The following general formula (2)
(R ⁴ R ⁵ SiO _2/2 ) (2)
(Wherein R ⁴ and R ⁵ are independent, the same or different organic groups),
The following general formula (3)
(R ⁶ SiO _3/2 ) (3)
(Wherein R ⁶ is an organic group) and the following general formula (4)
(SiO _4/2 ) (4)
And having one or more structural units selected from structural units represented by:
The following general formula (5)
(R ⁷ _a (OR ⁸ ) _3-a SiO _1/2 ) (5)
(However, a is 0, 1 or 2, and R ⁷ and R ⁸ are independent, the same or different organic groups, and when a plurality of R ⁷ or R ⁸ are contained, each R ⁷ Or R ⁸ may be the same or different from each other.)
The following general formula (6)
(R ⁹ _b (OR ¹⁰ ) _2-b SiO _2/2 ) (6)
(However, b is 0 or 1, R ⁹ and R ¹⁰ are each independently the same or different organic groups, and when a plurality of R ¹⁰ are contained, each R ¹⁰ is the same as each other. And may be different from each other.) And the following general formula (7)
((OR ¹¹ ) SiO _3/2 ) (7)
(Wherein R ¹¹ is an organic group), having one or more structural units selected from the structural units represented by:
When all the siloxane units constituting the alkoxy oligomer are 100 mol%, 90 to 100 mol% of one or more structural units selected from the structural units represented by the general formula (1) to the general formula (7) are included. A curable resin composition characterized by
(Ii) The curable resin composition according to the above (i), comprising 0.1 to 20 parts by mass of phosphoric acid as a curing catalyst with respect to 100 parts by mass of the total amount of the alkoxy oligomer and the silicone resin,
(Iii) The curable resin composition according to the above (i) or (ii), wherein the amount of alkoxyl group contained in the alkoxy oligomer is 10 to 30% by mass,
(Iv) The curable resin composition according to any one of the above (i) to (iii), wherein the amount of cure shrinkage of the solidified product obtained by curing the curable resin composition is 10% by mass or less. ,
(V) When the solidified body obtained by curing the curable resin composition is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 500 hours, the solidified body has a transmittance of 85% with respect to the ultraviolet light. The curable resin composition according to any one of (i) to (iv) above,
(Vi) When the solidified body obtained by curing the curable resin composition is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 1000 hours, the solidified body has a transmittance of 85% with respect to the ultraviolet light. The curable resin composition according to any one of (i) to (iv) above,
(Vii) When the solidified body obtained by curing the curable resin composition is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 5000 hours, the solidified body has a transmittance of 80% for the ultraviolet light. The curable resin composition according to any one of (i) to (iv) above,
(Viii) The curable resin composition according to any one of (i) to (vii) above, wherein an emission peak wavelength of the ultraviolet light is 365 nm,
(Ix) An optical element comprising a cured product of the curable resin composition according to any one of (i) to (viii) above,
(X) an optical semiconductor device comprising an optical semiconductor element sealed with the curable resin composition according to any one of (i) to (viii) above,
(Xi) An optical semiconductor device comprising the optical element according to (ix) above,
(Xii) The optical semiconductor device according to (x), wherein the optical semiconductor element emits light in an ultraviolet region.

  According to the present invention, compared with the conventional curable resin composition, the transparency in the ultraviolet region, the ultraviolet resistance and the heat resistance are extremely high. Even if it is used, it is possible to provide a curable resin composition that can suppress the occurrence of cracks, peeling, and coloring and can suppress curing shrinkage, and an optical element comprising a cured product of the curable resin composition, and An optical semiconductor device can be provided.

1 is a schematic configuration diagram of a surface mount ultraviolet LED to which a curable resin composition according to an embodiment of the present invention is applied. It is a schematic block diagram of package type ultraviolet LED to which the curable resin composition which concerns on embodiment of this invention was applied. It is a graph which shows the transmittance | permeability measurement result of the curable resin composition which concerns on Example 1 of this invention. It is a graph which shows the measurement result of the emitted light intensity of the curable resin composition which concerns on Example 1 of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
The description of the constituent requirements described below is an example of the embodiment of the present invention, and the present invention is not limited to these contents, and various modifications can be made within the scope of the invention. it can.

  The curable resin composition of the present invention is used, for example, as a sealing material or an optical element material for an ultraviolet LED that applies high power, and includes an alkoxy oligomer and a silicone resin.

[Alkoxy oligomer]
In the curable resin composition according to the present invention, the alkoxy oligomer has an organopolysiloxane structure,
The following general formula (1)
(R ¹ R ² R ³ SiO _1/2 ) (1)
(Wherein R ¹ , R ² and R ³ are each independently the same or different organic groups),
The following general formula (2)
(R ⁴ R ⁵ SiO _2/2 ) (2)
(Wherein R ⁴ and R ⁵ are independent, the same or different organic groups),
The following general formula (3)
(R ⁶ SiO _3/2 ) (3)
(Wherein R ⁶ is an organic group) and the following general formula (4)
(SiO _4/2 ) (4)
And having one or more structural units selected from structural units represented by:
The following general formula (5)
(R ⁷ _a (OR ⁸ ) _3-a SiO _1/2 ) (5)
(However, a is 0, 1 or 2, and R ⁷ and R ⁸ are independent, the same or different organic groups, and when a plurality of R ⁷ or R ⁸ are contained, each R ⁷ Or R ⁸ may be the same or different from each other.)
The following general formula (6)
(R ⁹ _b (OR ¹⁰ ) _2-b SiO _2/2 ) (6)
(However, b is 0 or 1, R ⁹ and R ¹⁰ are each independently the same or different organic groups, and when a plurality of R ¹⁰ are contained, each R ¹⁰ is the same as each other. And may be different from each other.) And the following general formula (7)
((OR ¹¹ ) SiO _3/2 ) (7)
(Wherein R ¹¹ is an organic group), having one or more structural units selected from the structural units represented by:
When the total siloxane unit constituting the alkoxy oligomer is 100 mol%, it contains 90 to 100 mol% of one or more structural units selected from the structural units represented by the general formula (1) to the general formula (7). .

The structural unit represented by the general formula (1), that is, the structural unit represented by (R ¹ R ² R ³ SiO _1/2 ) is a monofunctional structural unit (M unit), and the general formula (2 ), That is, the structural unit represented by (R ⁴ R ⁵ SiO _2/2 ) is a bifunctional structural unit (D unit) and is represented by the general formula (3). That is, the structural unit represented by (R ⁶ SiO _3/2 ) is a trifunctional structural unit (T unit), and the structural unit represented by the general formula (4), that is, (SiO _4/2 ) The structural unit represented is a tetrafunctional structural unit.
In the structural unit represented by the general formula (5), that is, the structural unit represented by (R ⁷ _a (OR ⁸ ) _{3 -a} SiO _1/2 ), a is 0, 1 or 2. When a is 2, a bifunctional structural unit having one alkoxy group OR ⁸ represented by (R ⁷ ₂ (OR ⁸ ) SiO _1/2 ), and a is 1 , (R ⁷ (OR ⁸ ) ₂ SiO _1/2 ), a trifunctional structural unit having two alkoxy groups OR ⁸ represented by (R ⁷ (OR ⁸ ) ₂ SiO _1/2 ), and when a is 0, ((OR ⁸ ) ₃ SiO _{1 / 2)} a tetrafunctional structural unit having three alkoxy groups OR ⁸ represented by.
In the structural unit represented by the general formula (6), that is, the structural unit represented by (R ⁹ _b (OR ¹⁰ ) _{2 -b} SiO _2/2 ), b is 0 or 1, and b is 1 is a trifunctional structural unit having one alkoxy group OR ¹⁰ represented by (R ⁹ (OR ¹⁰ ) SiO _2/2 ), and when b is 0, ((OR ¹⁰ ) ₂ SiO _2/2) is a tetrafunctional structural unit alkoxy group ^{OR 10} having two represented by.
The structural unit represented by the general formula (7), that is, the structural unit represented by ((OR ¹¹ ) SiO _3/2 ) is a tetrafunctional structural unit having one alkoxy group OR ¹¹ .

In the compound represented by the general formula (1), R ¹ , R ² and R ³ are independent, the same or different organic groups, respectively. In the compound represented by the general formula (2), R 1 ⁴ and R ⁵ are independently the same or different organic groups. In the compound represented by the general formula (3), R ⁶ is an organic group.
In the general formula (5), R ⁷ and R ⁸ are independent, the same or different organic groups, and when a plurality of R ⁷ and R ⁸ are contained, each R ⁷ and R ⁸ is They may be the same or different.
In the compound represented by the general formula (6), R ⁹ and R ¹⁰ are independently the same or different organic groups, and when a plurality of R ¹⁰ are contained, each R ¹⁰ is the same as each other. May be different.
In the compound represented by the general formula (7), R ¹¹ is an organic group.
Thus, the organic groups represented by R ^{1 to} R ¹¹ are the same or different organic groups that are independent of each other.
The organic group represented by R ^{1 to} R ¹¹ is preferably a hydrocarbon group, more preferably a hydrocarbon group having 1 to 12 carbon atoms, still more preferably a hydrocarbon group having 1 to 8 carbon atoms, and 1 to 1 carbon atom. The hydrocarbon group having 4 carbon atoms is more preferable, the hydrocarbon group having 1 to 3 carbon atoms is still more preferable, and the hydrocarbon group having 1 to 2 carbon atoms is particularly preferable.
As said hydrocarbon group, 1 or more types chosen from an alkyl group can be mentioned.

  When the hydrocarbon group is an alkyl group, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. One or more selected from a group and the like can be mentioned, and a methyl group or an ethyl group is preferable, and a methyl group is more preferable.

In the curable resin composition of the present invention, as the alkoxy oligomer, at least one organic group of the organic groups contained in the structural unit constituting the alkoxy oligomer is an alkyl group having 1 to 4 carbon atoms, and other than the above alkyl group. What an organic group is a C1-C8 hydrocarbon group is preferable.
In the curable resin composition of the present invention, the alkoxy oligomer is preferably one in which at least one of organic groups contained in the constituent unit constituting the alkoxy oligomer is a methyl group, and contained in the constituent unit constituting the alkoxy oligomer. More preferably, all organic groups are methyl groups.

In general, the ionic bondability of Si—O bond, which is the main chain of silicone, is about 50%, which is larger than the CC bond of common organic resins such as polyethylene. For this reason, the chemical stability such as C—H bond and C—C bond of the side chain of silicone is increased as compared with the case where the main chain is C—C bond. The structure is not easily affected.
However, if the side chain such as C—H bond or C—C bond becomes large and the distance between the atoms constituting the side chain and the Si atom is increased, the contribution of stabilization due to the ionic bonding property of the Si—O bond decreases. Problem occurs. For this reason, it is preferable that the number of carbon atoms of the side chain organic group (that is, the organic group represented by R ^{1 to} R ¹¹ ) is smaller. Among them, the methyl group is the smallest among the alkyl groups, and all of the methyl groups are formed. And the Si atom (to which a methyl group is bonded) are close to each other, are easily stabilized by ionic bonds, and are free from C—C bonds.

Moreover, as an organic group represented by R < ¹ > -R < ¹¹ >, what does not contain an aromatic ring is preferable.
As the organic group represented by R ^{1 to} R ¹¹ , for example, when a group having an aromatic ring such as a phenyl group is used, the functional group has a double bond. Due to the π-π * transition, absorption occurs from the ultraviolet light region to the visible light region, and the transmission characteristics and ultraviolet resistance in the ultraviolet region are likely to deteriorate. Therefore, the organic group represented by R ^{1 to} R ¹¹ is preferably a group that does not contain an aromatic ring such as a benzene aromatic ring, a heteroaromatic ring, or a non-benzene aromatic ring.
In addition, the organic group represented by R ^{1 to} R ¹¹ does not include an N atom-containing group (such as an amino group) or an S atom-containing group (such as a mercapto group) in order to suppress a decrease in UV resistance. Those are preferred. For the same reason, even when the organic group represented by R ^{1 to} R ¹¹ is a hydrocarbon other than an aromatic hydrocarbon, a carbon-carbon bond (C—C bond, C═C bond or C≡) It is preferable that the C bond) -containing group is not contained as much as possible.

As described above, in the curable resin composition of the present invention, the alkoxy oligomer is a structural unit represented by the general formula (5) as a structural unit having an alkoxy group, that is, (R ⁷ _a (OR ⁸ ) _{3. -A} SiO _1/2 )), a structural unit represented by the general formula (6), that is, a structural unit represented by (R ⁹ _b (OR ¹⁰ ) _2-b SiO _2/2 ), One or more structural units selected from structural units represented by the formula (7), that is, structural units represented by ((OR ¹¹ ) SiO _3/2 ) are included.
In the curable resin composition of the present invention, the alkoxy oligomer includes a structural unit having an alkoxy group selected from the structural units represented by the general formula (5) to the general formula (7). When used as a sealing material for an optical semiconductor element constituting the above, it is considered that the alkoxy group and the die surface, substrate surface, wiring pattern surface, and the like to be sealed are chemically bonded.
That is, since a protective layer made of SiO ₂ or the like is provided on the surface of a die or the like made of an inorganic substance and usually has a hydroxyl group, it is represented by the above general formula (5) to general formula (7). The alkoxy group in the structural unit selected from the structural units is bonded to the hydroxyl group on the die surface by a hydrogen bond or intermolecular force due to van der Waals force, and further the dealcohol condensation between the alkoxy group and the hydroxyl group on the die surface. It is considered that a bond is formed by reaction and dehydration reaction, and both are considered to be chemically strongly bonded.
Thus, when the curable resin composition of the present invention is used as a sealing material, a cured product (solidified body) obtained by curing the curable resin composition of the present invention and a die are firmly bonded, For this reason, even if it is a case where it uses for the sealing application of ultraviolet LED which applies high electric power, generation | occurrence | production of the crack, peeling, etc. to the hardened | cured material (solidified body) of a curable resin composition can be suppressed effectively. it is conceivable that.

In the curable resin composition of the present invention, the alkoxy oligomer has 90 structural units represented by the general formula (1) to the general formula (7) when the total siloxane unit constituting the alkoxy oligomer is 100 mol%. To 100 mol%, and preferably contains 95 to 100 mol% of structural units represented by general formula (1) to general formula (7). In general formula (1) to general formula (7) It is more preferable that the constituent unit represented is 100 mol%.
That is, in the curable resin composition of the present invention, the alkoxy oligomer, when the total siloxane unit constituting the alkoxy oligomer is 100 mol%, the content mol% of the structural unit represented by the general formula (1), The content mol% of the structural unit represented by the general formula (2), the content mol% of the structural unit represented by the general formula (3), and the content mol% of the structural unit represented by the general formula (4) The content mol% of the structural unit represented by the general formula (5), the content mol% of the structural unit represented by the general formula (6), and the content mol% of the structural unit represented by the general formula (7) Is a compound having a total content of 90 to 100 mol%, more preferably 95 to 100 mol%, and more preferably 100 mol% (all siloxane units constituting the silicone resin are represented by the above general formula (1) to general formula). Any structure represented by Formula (7) Is composed are) those in unit is more preferable.

In the constitutional unit constituting the alkoxy oligomer, the constitutional ratio of the constitutional units represented by the general formula (1) to the general formula (7) is not particularly limited, but when a certain amount of non-reactive functional group is not contained, curing is performed. When the curable resin composition is cured, the cured product (solidified body) becomes too hard, the stress generated during heating and cooling cannot be relieved, the bonding wire in the ultraviolet LED is cut, the LED die It may damage itself.
Therefore, in the curable resin composition of the present invention, the alkoxy oligomer is an atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the alkoxy oligomer (total amount of O atoms contained in the alkoxy oligomer / alkoxy oligomer). Is preferably 2.3 to 3.5, more preferably 2.3 to 3.4, and even more preferably 2.2 to 3.2. preferable.
When the atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the alkoxy oligomer is within the above range, a certain amount of non-reactive functional groups can be included. The stress generated during cooling can be preferably alleviated.
When the atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the alkoxy oligomer is less than 2.3, the UV resistance tends to be lowered, and when it exceeds 3.5, the curable resin composition is cured. Cracks and cracks in objects (solidified bodies) are likely to occur.
The atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the alkoxy oligomer adjusts the constituent ratio of the structural units represented by the general formulas (1) to (7) that constitute the alkoxy oligomer. Can be controlled.

In the curable resin composition of the present invention, the alkoxy oligomer has a ratio of the number of moles of the bifunctional structural unit to the total number of moles of the bifunctional structural unit and the trifunctional structural unit constituting the alkoxy oligomer within a predetermined range. Some are preferred.
That is, in the curable resin composition of the present invention, the alkoxy oligomer is 2 in the structural unit (R ⁷ _a (OR ⁸ ) _{3 -a} SiO _1/2 ) represented by the general formula (5). The total number of moles of the structural unit (R ⁴ R ⁵ SiO _2/2 ) and the structural unit (R ⁴ R ⁵ SiO _2/2 ) represented by the general formula (2) and the structural unit (R ⁷ ₂ (OR ⁸ ) SiO _1/2 ) A structural unit (R ⁷ (OR ⁸ ) ₂ SiO ₁ in which a is 1 in the structural unit (R ⁷ _a (OR ⁸ ) _3-a SiO _1/2 ) represented by the general formula (5) as Dn. _{/ 2} ) and a structural unit (R ⁹ (OR ¹⁰ ) SiO ₂ in the case where b is 1 in the structural unit represented by the general formula (VI) (R ⁹ _b (OR ¹⁰ ) _2-b SiO _2/2 ). _{/ 2)} and the general formula (3) T units represented by the referred structural unit ^{(R 6} the total number of moles of iO _3/2) when the Tn, the ratio expressed by Tn / (Dn + Tn) is preferably from 0.2 to 1, more preferably from 0.25 to 1 0.3 to 1 is more preferable.

In the structural unit (R ⁷ _a (OR ⁸ ) _3-a SiO _1/2 ) represented by the general formula (5), the structural unit (R ⁷ ₂ (OR ⁸ ) SiO _1/2 ) when a is 2 ) Is usually in a state where some alkoxy groups of the raw material of the structural unit (R ⁴ R ⁵ SiO _2/2 ) represented by the general formula (2) remain unreacted during the preparation of the alkoxy oligomer. Incorporated into the oligomer.
In the structural unit (R ⁷ _a (OR ⁸ ) _{3 -a} SiO _1/2 ) represented by the general formula (5), the structural unit (R ⁷ (OR ⁸ ) ₂ SiO ₁ ) when a is _{1 / 2} ) or a structural unit (R ⁹ (OR ¹⁰ ) SiO in the case where b is 1 in the structural unit represented by the general formula (6) (R ⁹ _b (OR ¹⁰ ) _2-b SiO _2/2 ). _2/2 ) is usually a state in which some alkoxy groups of the raw material of the structural unit (R ⁶ SiO _3/2 ) represented by the general formula (8) remain unreacted during the preparation of the alkoxy oligomer. Incorporated into the oligomer.
As described above, when the curable resin composition of the present invention is used as a sealing material for an optical semiconductor element constituting an optical semiconductor device, the alkoxy oligomer is represented by the general formulas (5) to (7). It is considered that the alkoxy group in the structural unit represented by the above and the die surface, the substrate surface, the wiring pattern surface, etc. to be sealed are chemically firmly bonded. In consideration of the balance between the alkoxy group and the organic group, it is preferable that the alkoxy oligomer is composed exclusively of a bifunctional structural unit and a trifunctional structural unit. Considering the characteristics, it is advantageous that Tn is larger than Dn.
When the ratio represented by Tn / (Dn + Tn) is within the above range, the curable resin composition can be suitably bonded to the die surface or the like when used as a sealing material for an optical semiconductor element. Can be used to seal high-power ultraviolet LEDs and the like and continue to be exposed to strong ultraviolet light, but cracks and peeling at the interface between the die surface and the cured product (solidified product) of the curable resin composition Generation | occurrence | production of can be suppressed suitably.

In the curable resin composition of the present invention, the amount of alkoxyl group contained in the alkoxy oligomer is preferably 10 to 30% by mass, more preferably 11 to 27.5% by mass, and 12 to 25% by mass. % Is more preferable.
When the amount of the alkoxyl group contained in the alkoxy oligomer is within the above range, the desired stress relaxation ability can be exhibited while suppressing the three-dimensional bond while maintaining the desired solid content concentration.

In the curable resin composition of the present invention, the mass average molecular weight of the alkoxy oligomer is not particularly limited and may be appropriately selected depending on the purpose of use. When used as a sealing material for an optical semiconductor element such as an ultraviolet LED. Any selection may be made according to the purpose.
The mass average molecular weight of the alkoxy oligomer is preferably 500 to 4,500, more preferably 750 to 4,250, and still more preferably 1,000 to 4,000. The amount of hydroxyl group (OH) contained in the alkoxy oligomer is preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less.

In the curable resin composition of the present invention, the production method of the alkoxy oligomer is not particularly limited.
In the curable resin composition of the present invention, the alkoxy oligomer includes, for example, the following general formula (1) ′ to general formula (4) ′ corresponding to the siloxane units represented by the general formula (1) to the general formula (4). One or more selected from the group consisting of organoxysiloxanes can be blended in a predetermined amount, and then hydrolyzed and condensed.
R ¹² R ¹³ R ¹⁴ SiOR ¹⁵ (1) ′
(However, R ¹² , R ¹³ , R ^14, and R ¹⁵ are independent, identical or different organic groups.)
R ¹⁶ R ¹⁷ Si (OR ¹⁸ ) (OR ¹⁹ ) (2) ′
(However, R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are each independently the same or different organic group.)
R ²⁰ Si (OR ²¹ ) (OR ²² ) (OR ²³ ) (3) ′
(However, R ²⁰ , R ²¹ , R ^22, and R ²³ are independent, identical or different organic groups.)
Si (OR ²⁴ ) (OR ²⁵ ) (OR ²⁶ ) (OR ²⁷ ) (4) ′
(However, R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ are each independently the same or different organic group.)
Examples of the organic group represented by R ^{12 to} R ²⁷ include the same groups as the organic groups represented by R ^{1 to} R ¹¹ described above.
In the hydrolysis and condensation reactions, a certain amount of alkoxy groups remain in the hydrolyzate without causing the hydrolysis reaction to proceed completely. An alkoxy group (—OR ¹⁸ group, —OR ¹⁹ group, —OR ²¹ group, —OR ²² group, —OR ²³ group) constituting the organoxysiloxane represented by the general formula (2) ′ to the general formula (4) ′. , -OR ²⁴ group, -OR ²⁵ group, -OR ²⁶ group, -OR ²⁷ group), the remaining alkoxy oligomer is represented by general formula (5) to general formula (7) in the resulting alkoxy oligomer. One or more siloxane units selected from siloxane units can be formed.
The residual amount of the alkoxy group can be controlled by appropriately adjusting the hydrolysis and condensation conditions (catalyst used, reaction time, reaction temperature, etc.).
What is necessary is just to determine suitably the compounding ratio of the organoxysiloxane represented by General formula (1) '-General formula (4)' according to the alkoxy oligomer to obtain.

In the curable resin composition of the present invention, as a method for producing an alkoxy oligomer, specifically, for example, methyltrimethoxysilane (representative formula: CH ₃ Si (OCH ₃ ) ₃ , hereinafter abbreviated as MTMS). And a method of hydrolyzing MTMS and dimethyldimethoxysilane (a mixture of the following formula: (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , hereinafter abbreviated as DMDMS)) in the presence of a catalyst and water. it can.
Moreover, as an alkoxy oligomer in the curable resin composition of this invention, the silicone alkoxy oligomer manufactured by methods other than the method mentioned above may be sufficient.
Examples of the alkoxy oligomer include silicone alkoxy oligomers x-40-9225, X-40-9246, X-40-9250, KC-89S, KR-500 manufactured by Shin-Etsu Chemical Co., Ltd. and Momentive Performance Materials. -Japan GK XC-96-B0446, XR31-B1410, XR31-B2230, etc. can be mentioned.

  In the curable resin composition of the present invention, the alkoxy oligomer is prepared by hydrolyzing and condensing one or more selected from the organoxysiloxanes represented by the general formula (1) ′ to the general formula (4) ′. In the presence of a catalyst, it can be usually prepared by reacting at a temperature of about 0 ° C. to 100 ° C. for several tens of minutes to about a day.

  As a catalyst used when hydrolyzing and condensing the organoxysiloxane represented by the general formula (1) ′ to the general formula (4) ′, inorganic catalysts such as hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, and phosphoric acid are used. Organic acids such as acids, formic acid and acetic acid can be used. Moreover, in order to carry out a cohydrolysis and a condensation reaction, you may add an organic solvent as needed. In this case, as the solvent, alcohols such as methanol, ethanol, 1-propanol, and 2-propanol, aromatic compounds such as toluene and xylene, ketones such as acetone, and esters such as ethyl acetate can be used.

In the organoxysiloxane represented by the above general formula (1) ′ to general formula (4) ′, the organic group represented by R ^{12 to} R ²⁷ preferably does not contain an aromatic ring.
As described above, as the organic group represented by R ^{12 to} R ²⁷ , for example, when a group having an aromatic ring such as a phenyl group is used, the functional group has a double bond. Due to the π-π * transition derived from the π electrons, absorption occurs from the ultraviolet light region to the visible light region, and the transmission characteristics and ultraviolet resistance in the ultraviolet region are likely to deteriorate. Therefore, the organic group represented by R ^{12 to} R ²⁷ is preferably a group that does not contain an aromatic ring such as a benzene aromatic ring, a heteroaromatic ring, or a non-benzene aromatic ring.
Further, the organic group represented by R ^{12 to} R ²⁷ does not include an N atom-containing group (such as an amino group) or an S atom-containing group (such as a mercapto group) in order to suppress a decrease in UV resistance. It is preferably a group. For the same reason, even when the organic group represented by R ^{12 to} R ²⁷ is a hydrocarbon other than an aromatic hydrocarbon, a carbon-carbon bond (C—C bond, C═C bond or C≡C The bond) -containing group is preferably not contained as much as possible.

In the curable resin composition of the present invention, the alkoxy oligomer is preferably a silicone material having an organosiloxane structure in a liquid state at room temperature (25 ° C.).
In the curable resin composition of the present invention, since the alkoxy oligomer is in a liquid state at room temperature (25 ° C.), the solid silicone resin can be dissolved into a liquid state, and filling and molding can be easily performed. It can be carried out.
In the present application document, being in a liquid state at room temperature means having a viscosity at room temperature of 10 ³ Pa · s or less as measured according to JIS Z 8803.

  The curable resin composition of the present invention contains 20 to 85% by mass of an alkoxy oligomer in terms of solid content (nonvolatile content), preferably 22.5 to 80% by mass, and preferably 25 to 75% by mass. More preferred.

  In the curable resin composition of the present invention, when the content of the alkoxy oligomer is within the above range, transparency in the ultraviolet region, ultraviolet resistance and heat resistance are improved as compared with the conventional curable resin composition. Even if it is extremely high and is used for sealing an ultraviolet LED to which a large electric power is applied, the occurrence of cracks, peeling and coloring can be effectively suppressed.

Even a curable resin composition containing only the above-mentioned alkoxy oligomer as an organopolysiloxane has extremely high transparency, ultraviolet resistance and heat resistance in the ultraviolet region compared to conventional curable resin compositions. Even when used for sealing an ultraviolet LED to which electric power is applied, the occurrence of cracks, peeling, and coloring can be suppressed to a certain extent.
By the way, the curing reaction of the alkoxy oligomer is performed by hydrolysis reaction of alkoxyl group, dealcohol condensation reaction and dehydration condensation reaction that follow the hydrolysis reaction, and the alcohol and water produced by these reactions, Since the solidified body escapes during curing, the capacity may decrease and curing shrinkage (that is, deformation) may occur. In particular, when the sealing material is molded in a mold, the degree of the curing shrinkage is as follows. The larger the size, the different the shape of the obtained cured product (solidified body) from the shape to be obtained. If the shrinkage occurs uniformly, it is possible to design the mold shape in anticipation of the degree of shrinkage. However, the larger the cure shrinkage, the more difficult it is to shrink uniformly.
Therefore, the curable resin composition of the present invention contains a silicone resin, which will be described in detail below, together with the above alkoxy oligomer, reacts both at the time of curing to produce a specific organopolysiloxane, and cures to form a solid. The concentration is increased to solve this technical problem.

[Silicone resin]
The curable resin composition of the present invention contains a silicone resin together with an alkoxy oligomer.
Silicone resins include straight resins consisting only of a siloxane skeleton, and modified silicone resins modified with other organic resins (for example, epoxy resin modified, alkyd resin modified, polyester resin modified, etc.), but modified silicone resins are organic. Since the ultraviolet resistance of the resin part is inferior, in the curable resin composition of the present invention, the silicone resin is preferably a so-called straight resin.

In the curable resin composition according to the present invention, the silicone resin has an organopolysiloxane structure,
The following general formula (8)
_{^{(R 28 R 29 R 30 SiO}} 1/2) (8)
(Wherein R ²⁸ , R ²⁹ and R ³⁰ are each independently the same or different organic group),
The following general formula (9)
(R ³¹ R ³² SiO _2/2 ) (9)
(Wherein R ³¹ and R ³² are each independently the same or different organic group),
The following general formula (10)
(R ³³ SiO _3/2 ) (10)
(Wherein R ³³ is an organic group) and the following general formula (11)
(SiO _4/2 ) (11)
And having one or more structural units selected from structural units represented by:
The following general formula (12)
^{_{(R 34 d (OH) 3}} -d SiO 1/2) (12)
(However, d is 0, 1 or 2, R ³⁴ is an organic group, and when a plurality of R ³⁴ are contained, each R ³⁴ may be the same as or different from each other. )
The following general formula (13)
^{_{(R 35 e (OH) 2}} -e SiO 2/2) (13)
(However, e is 0 or 1, R ³⁵ is an organic group, and when a plurality of R ³⁵ are contained, each R ³⁵ may be the same as or different from each other.) The structural unit represented and the following general formula (14)
((OH) SiO _3/2 ) (14)
What has 1 or more types of structural units chosen from the structural unit represented by these is preferable.

The structural unit represented by the general formula (8), that is, the structural unit represented by (R ²⁸ R ²⁹ R ³⁰ SiO _1/2 ) is a monofunctional structural unit (M unit), and the general formula (9 ), That is, the structural unit represented by (R ³¹ R ³² SiO _2/2 ) is a bifunctional structural unit (D unit) and is represented by the general formula (10). That is, the structural unit represented by (R ³³ SiO _3/2 ) is a trifunctional structural unit (T unit), and the structural unit represented by the general formula (11), that is, (SiO _4/2 ) The structural unit represented is a tetrafunctional structural unit.
The structural unit represented by the general formula (12), that is, the structural unit represented by (R ³⁴ _d (OH) _{3 -d} SiO _1/2 ) is one in which d is 0, 1 or 2. And when d is 2, a bifunctional structural unit having one hydroxyl group (OH group) represented by (R ³⁴ ₂ (OH) SiO _1/2 ), and when d is 1, A trifunctional structural unit having two hydroxyl groups (OH groups) represented by (R ³⁴ (OH) ₂ SiO _1/2 ), and when d is 0, ((OH) ₃ SiO _1/2 ) The tetrafunctional structural unit which has three hydroxyl groups (OH group) represented by these.
In the structural unit represented by the general formula (13), that is, the structural unit represented by (R ³⁵ _e (OH) _{2 -e} SiO _2/2 ), e is 0 or 1, and e is 1 Is a trifunctional structural unit having one hydroxyl group (OH group) represented by (R ³⁵ (OH) SiO _2/2 ), and when e is 0, ((OH) ₂ SiO _{2 / 2} ) a tetrafunctional structural unit having two hydroxyl groups (OH groups) represented by
The structural unit represented by the general formula (14), that is, the structural unit represented by ((OH) SiO _3/2 ) is a tetrafunctional structural unit having one hydroxyl group (OH group).

In the compound represented by the general formula (8), R ²⁸ , R ²⁹ and R ³⁰ are independent, the same or different organic groups. In the compound represented by the general formula (9), R ^{28 31} and R ³² are independent, the same or different organic groups. In the compound represented by the general formula (10), R ³³ is an organic group.
In the general formula (12), R ³⁴ is an organic group, and when a plurality of R ³⁴ are contained, each R ³⁴ may be the same as or different from each other.
In the compound represented by the general formula (13), R ³⁵ is an organic group, and when a plurality of R ³⁵ are contained, each R ³⁵ may be the same as or different from each other.
Thus, the organic groups represented by R ^{28 to} R ³⁵ are the same or different organic groups that are independent of each other.
The organic group represented by R ^{28 to} R ³⁵ is preferably a hydrocarbon group, more preferably a hydrocarbon group having 1 to 12 carbon atoms, still more preferably a hydrocarbon group having 1 to 8 carbon atoms, and 1 to 1 carbon atom. The hydrocarbon group having 4 carbon atoms is more preferable, the hydrocarbon group having 1 to 3 carbon atoms is still more preferable, and the hydrocarbon group having 1 to 2 carbon atoms is particularly preferable.
As said hydrocarbon group, 1 or more types chosen from an alkyl group can be mentioned.

  When the hydrocarbon group is an alkyl group, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. A methyl group or an ethyl group is preferable, and a methyl group is more preferable.

In the curable resin composition of the present invention, as the silicone resin, at least one organic group of the organic groups contained in the structural unit constituting the silicone resin is an alkyl group having 1 to 4 carbon atoms, and other than the above alkyl groups. What an organic group is a C1-C8 hydrocarbon group is preferable.
In the curable resin composition of the present invention, the silicone resin is preferably one in which at least one of the organic groups contained in the constituent unit constituting the silicone resin is a methyl group, and contained in the constituent unit constituting the silicone resin. More preferably, all organic groups are methyl groups.

In general, the ionic bondability of Si—O bond, which is the main chain of silicone, is about 50%, which is larger than the CC bond of common organic resins such as polyethylene. For this reason, the chemical stability such as C—H bond and C—C bond of the side chain of silicone is increased as compared with the case where the main chain is C—C bond. The structure is not easily affected.
However, as described in the explanation of the alkoxy oligomer, when the side chain such as C—H bond or C—C bond becomes large and the distance between the atoms constituting the side chain and the Si atom increases, the Si—O bond There arises a problem that the contribution of stabilization due to ionic bonding properties is reduced. For this reason, it is preferable that the number of carbon atoms of the side chain organic group (that is, the organic group represented by R ^{28 to} R ³⁵ ) is smaller. Among them, the methyl group is the smallest among the alkyl groups, and all of the methyl groups are formed. And the Si atom (to which a methyl group is bonded) are close to each other, are easily stabilized by ionic bonds, and are free from C—C bonds.

In general, straight resins are roughly classified according to organic groups bonded to Si atoms. The above-described methyl groups bonded to methyl groups, phenyl groups bonded to phenyl groups, methyl groups / phenyl groups bonded to phenyl groups, and propyl groups. And a propyl / phenyl system to which a phenyl group is bonded.
In the curable resin composition of the present invention, when the silicone resin is a straight resin, the straight resin preferably does not contain an aromatic ring such as a phenyl group, and is therefore represented by R ^{28 to} R ^35. As the organic group, those not containing an aromatic ring such as a phenyl group are preferable.
As the organic group represented by R ^{28 to} R ³⁵ , for example, when a group having an aromatic ring such as a phenyl group is used, the functional group has a double bond. By the π-π * transition, absorption occurs from the ultraviolet light region to the visible light region, and the transmission property and ultraviolet resistance in the ultraviolet region are likely to be deteriorated. Therefore, the organic group represented by R ^{28 to} R ³⁵ is preferably a group that does not contain an aromatic ring such as a benzene aromatic ring, a heteroaromatic ring, or a non-benzene aromatic ring.
Further, the organic group represented by R ^{28 to} R ³⁵ does not contain an N atom-containing group (such as an amino group) or an S atom-containing group (such as a mercapto group) in order to suppress a decrease in UV resistance. Those are preferred. For the same reason, when the organic group represented by R ^{28 to} R ³⁵ is a hydrocarbon other than an aromatic hydrocarbon, a carbon-carbon bond (C—C bond, C═C bond or C≡) is used. It is preferable that the C bond) -containing group is not contained as much as possible.

As described above, in the curable resin composition of the present invention, the silicone resin is a structural unit represented by the general formula (12) as a structural unit having a hydroxyl group, that is, (R ³⁴ _d (OH) _{3 -d.} A structural unit represented by (SiO _1/2 )), a structural unit represented by the general formula (13), that is, a structural unit represented by (R ³⁵ _e (OH) _{2 -e} SiO _2/2 ), a general formula (14 ), That is, one or more structural units selected from the structural units represented by ((OH) SiO _3/2 ).
As described above, the curing reaction of the alkoxy oligomer is performed by a hydrolysis reaction of the alkoxyl group, a dealcoholization condensation reaction that follows the hydrolysis reaction, and a dehydration condensation reaction. Since alcohol and water escape from the solidified body during curing, the capacity is reduced and curing shrinkage (that is, deformation) may occur.
On the other hand, in the curable resin composition of the present invention, the silicone resin contains any one or more of the structural units having a hydroxyl group represented by the general formula (12) to the general formula (14). When used as a sealing material for an optical semiconductor element constituting an optical semiconductor device, the alkoxy group contained in the alkoxy oligomer reacts with the hydroxyl group during the curing reaction, and the alkoxy oligomer and the silicone resin become siloxane bonds (Si- O-Si bond).
Since the volume of by-products (alcohol and water) produced during the reaction between the alkoxy oligomer and the silicone resin is smaller than the volume of by-products (alcohol and water) produced when the alkoxy oligomer alone is reacted, the alkoxy oligomer Compared to the case of using only the resin, curing shrinkage (deformation) during the curing reaction can be suitably suppressed.

In the curable resin composition of the present invention, the silicone resin has 90 constituent units represented by the general formulas (1) to (7) when the total siloxane units constituting the silicone resin are 100 mol%. To 100 mol%, preferably 90 to 100 mol% of structural units represented by general formula (8) to general formula (14), and represented by general formula (8) to general formula (14) It is more preferable that the constituent unit represented is 95 to 100 mol%, and it is more preferable that the constituent unit represented by the general formula (8) to the general formula (14) is 100 mol%.
That is, in the curable resin composition of the present invention, the silicone resin, when the total siloxane unit constituting the silicone resin is 100 mol%, the content mol% of the structural unit represented by the general formula (8), The content mol% of the structural unit represented by the general formula (9), the content mol% of the structural unit represented by the general formula (10), and the content mol% of the structural unit represented by the general formula (11) The content mol% of the structural unit represented by the general formula (12), the content mol% of the structural unit represented by the general formula (13), and the content mol% of the structural unit represented by the general formula (14) Is preferably 90 to 100 mol%, more preferably 95 to 100 mol%, and 100 mol% (all siloxane units constituting the silicone resin are represented by the above general formula (8) to generality). Izu represented by formula (14) Is composed of Kano constituent units) is more preferable.

In the constitutional unit constituting the silicone resin, the constitutional ratio of the constitutional units represented by the general formula (8) to the general formula (14) is not particularly limited, but when a certain amount of non-reactive functional group is not contained, curing is performed. When the curable resin composition is cured, the cured product (solidified body) becomes too hard, the stress generated during heating and cooling cannot be relieved, the bonding wire in the ultraviolet LED is cut, the LED die It may damage itself.
Therefore, in the curable resin composition of the present invention, the silicone resin contains an atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the silicone resin (total amount of O atoms contained in the alkoxy oligomer / alkoxy oligomer). Is preferably 2.3 to 3.5, more preferably 2.3 to 3.4, and even more preferably 2.2 to 3.2. preferable.
When the atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the silicone resin is within the above range, a certain amount of non-reactive functional groups can be included. The stress generated during cooling can be preferably alleviated.
When the atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the silicone resin is less than 2.3, the UV resistance is liable to decrease, and when it exceeds 3.5, the curable resin composition is cured. Cracks and cracks in objects (solidified bodies) are likely to occur.
The atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the silicone resin adjusts the constituent ratio of the structural units represented by the general formulas (8) to (14) constituting the silicone resin. Can be controlled.

The amount of hydroxyl group contained in the silicone resin is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, and 0.3 to 2.5% by mass. Further preferred.
In the curable resin composition of the present invention, when the amount of hydroxyl group contained in the silicone resin is within the above range, curing shrinkage during the curing reaction can be easily suppressed, and the alkoxy group or alkoxy group of the alkoxy oligomer is hydrolyzed. The hydroxyl group generated by decomposition and the hydroxyl group of the silicone resin are bonded by dealcoholization condensation or dehydration condensation reaction, and the curable resin composition is cured to easily form a solidified body having a strong structure, Furthermore, bonds due to a dehydration condensation reaction occur with hydroxyl groups on the die surface, substrate surface, and wiring pattern surface to be sealed, and a strong bond can be easily formed on these surfaces.

The amount of alkoxyl group contained in the silicone resin is preferably 5% by mass or less, more preferably 2.5% by mass or less, and further preferably 1.0% by mass or less. .
In the curable resin composition of the present invention, when the amount of alkoxyl group contained in the silicone resin is within the above range, curing shrinkage during the curing reaction can be easily suppressed.

In the curable resin composition of the present invention, the method for producing the silicone resin is not particularly limited.
In the curable resin composition of the present invention, the silicone resin is, for example, the following general formula (8) ′ to general formula (11) ′ corresponding to the siloxane units represented by the general formula (8) to the general formula (11). Each of the silicon compounds represented by formula (I) can be prepared by blending a predetermined amount, hydrolyzing and condensing.
R ³⁶ R ³⁷ R ³⁸ SiOH (8) '
(However, R ³⁶ , R ³⁷ and R ³⁸ are each independently the same or different organic group.)
R ³⁹ R ⁴⁰ Si (OH) ₂ (9) ′
(However, R ³⁹ and R ⁴⁰ are the same or different organic groups which are independent of each other.)
R ⁴¹ Si (OH) ₃ (10) ′
(However, R ⁴¹ is an organic group.)
Si (OH) ₄ (11) ′
Examples of the organic group represented by R ^{36 to} R ⁴¹ include the same groups as the organic groups represented by R ^{28 to} R ³³ described above.
In the hydrolysis and condensation reaction, a certain amount of hydroxyl groups remain in the hydrolyzate without causing the hydrolysis reaction to proceed completely. A part of the hydroxyl group (—OH group) constituting the silicon compound represented by the general formula (8) ′ to the general formula (11) ′ remains, so that the general formula (12) to the general formula in the obtained silicone resin. One or more siloxane units selected from siloxane units represented by the formula (14) can be formed.
The residual amount of the hydroxyl group can be controlled by appropriately adjusting the hydrolysis and condensation conditions (catalyst used, reaction time, reaction temperature, etc.).
What is necessary is just to select suitably the compounding ratio of the silicon compound represented by General formula (8) '-General formula (11)' according to the silicone resin to obtain.
In the curable resin composition of the present invention, the silicone resin may be a silicone resin produced by a method other than the method described above.
Examples of the silicone resin include silicone resins KR-220L and KR-220LP manufactured by Shin-Etsu Chemical Co., Ltd., YR3370 manufactured by Momentive Performance Materials Japan GK, Wacker Silicones SILRES MK and SILRES 610 manufactured by Asahi Kasei Corporation. Etc.

  In the curable resin composition of the present invention, when the silicone resin is prepared by hydrolyzing and condensing the silicon compound represented by the general formula (8) ′ to the general formula (11) ′, usually in the presence of a catalyst. It can be prepared by reacting at a temperature of about 0 ° C. to 100 ° C. for several tens of minutes to about a day.

  As a catalyst used when hydrolyzing and condensing the silicon compound represented by the general formula (8) ′ to the general formula (11) ′, an inorganic acid such as hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, phosphoric acid or the like is used. Organic acids such as formic acid and acetic acid can be used. Moreover, in order to carry out a cohydrolysis and a condensation reaction, you may add an organic solvent as needed. In this case, as the solvent, alcohols such as methanol, ethanol, 1-propanol, and 2-propanol, aromatic compounds such as toluene and xylene, ketones such as acetone, and esters such as ethyl acetate can be used.

In the silicon compound represented by the general formula (8) ′ to the general formula (11) ′, the organic group represented by R ^{36 to} R ⁴¹ preferably does not include an aromatic ring.
As described above, as the organic group represented by R ^{36 to} R ⁴¹ , for example, when a group having an aromatic ring such as a phenyl group is used, the functional group has a double bond. Due to the π-π * transition derived from the π electrons, absorption occurs from the ultraviolet light region to the visible light region, and the transmission characteristics and ultraviolet resistance in the ultraviolet region are likely to deteriorate. Therefore, the organic group represented by R ^{36 to} R ⁴¹ is preferably a group that does not contain an aromatic ring such as a benzene aromatic ring, a heteroaromatic ring, or a non-benzene aromatic ring.
Further, the organic group represented by R ^{36 to} R ⁴¹ does not include an N atom-containing group (such as an amino group) or an S atom-containing group (such as a mercapto group) in order to suppress a decrease in UV resistance. It is preferably a group. For the same reason, even when the organic group represented by R ^{36 to} R ⁴¹ is a hydrocarbon other than an aromatic hydrocarbon, a carbon-carbon bond (C—C bond, C═C bond or C≡C The bond) -containing group is preferably not contained as much as possible.

In the curable resin composition of the present invention, the mass average molecular weight of the silicone resin is not particularly limited, and may be appropriately selected according to the purpose of use. When used as a sealing material for an optical semiconductor element such as an ultraviolet LED. Any selection may be made according to the purpose.
The weight average molecular weight of the silicone resin is preferably more than 4,000 and 20,000 or less, more preferably more than 4,250 and 17,500 or less, and more than 4,500 and 15,000 or less. More preferably.

In the curable resin composition of the present invention, the silicone resin is a silicone-based material having an organosiloxane structure in a solid state at room temperature (25 ° C.).
Since the silicone resin is in a solid state at room temperature (25 ° C.), the number of reactive functional groups in the silicone resin is smaller than that of the liquid silicone resin, and the curing shrinkage during the curing reaction is effectively suppressed. be able to.
A silicone resin that is solid at room temperature (25 ° C.) has a higher molecular weight than that of a liquid silicone resin at room temperature (25 ° C.). Just choose.
Even in the case of a silicone resin having a large molecular weight, a liquid resin dissolved in a solvent is excluded from the silicone resin in the curable resin composition of the present invention because the solvent shrinks as the solvent evaporates during curing.
In addition, in this application document, being in a solid state at room temperature means that the viscosity at room temperature measured according to JIS Z 8803 is in a state exceeding 10 ² Pa · s.

  The curable resin composition of the present invention contains 15 to 80% by mass of silicone resin, preferably 20 to 77.5% by mass, and preferably 25 to 75% by mass in terms of solid content (nonvolatile content). More preferred.

  In the curable resin composition of the present invention, when the silicone resin content is within the above range, transparency in the ultraviolet region, ultraviolet resistance and heat resistance are improved as compared with conventional curable resin compositions. Even if it is extremely high and used for sealing an ultraviolet LED to which a large electric power is applied, it is possible to suppress generation of cracks, peeling and coloring, and to effectively suppress curing shrinkage during curing.

  The silicone resin cures when heated at a high temperature (for example, 200 ° C. or higher), but exhibits thermoplasticity (remeltability) at a temperature lower than that. Therefore, when the amount of the silicone resin is increased, even when mixed with the alkoxy oligomer, the properties remain, and the resin does not cure at a low temperature and tends to exhibit thermoplasticity. If such thermoplastic properties remain, when used for sealing an ultraviolet LED, the resin is heated by the heat generated by the ultraviolet LED, and the shape is likely to change (remelt).

  By heating at a high temperature, the thermoplasticity (remeltability) disappears (hardens), but the heat treatment at a high temperature may damage the chip body of the ultraviolet LED. The curable resin composition of the present invention can contain a predetermined amount of an alkoxy oligomer when the content ratio of the silicone resin is within the above range in terms of solid content. It is possible to easily provide a curable resin composition that is easily cured even at a junction temperature Tj (for example, about 120 ° C. or lower) and in which the solidified body does not exhibit thermoplasticity.

[Curing catalyst]
The curable resin composition of the present invention may contain a curing catalyst.
In the curable resin composition of the present invention, the alkoxy oligomer and the silicone resin can produce a specific organopolysiloxane and allow the curing reaction to proceed even in the absence of a catalyst. In order to accelerate curing, a curing catalyst may be further contained.
As the curing catalyst, for example, there may be mentioned phosphoric acid _H 3 PO _4, phosphate _H 3 PO ₄ is preferably subjected in the form of a mixed solution of phosphoric acid _H 3 PO ₄ and alkoxysilane. Specifically, a mixed solution obtained by mixing dimethyldimethoxysilane (DMDMS) with an aqueous solution of orthophosphoric acid (representative formula: H ₃ PO ₄ ) can be given.
The orthophosphoric acid aqueous solution contains H ₂ O, but as shown in the following chemical reaction formula, it reacts with the methoxy group (CH ₃ O—) of dimethyldimethoxysilane (DMDMS), and is completely consumed.
(CH ₃ ) ₂ Si (OCH ₃ ) ₂ + 2H ₂ O
→ (CH ₃ ) ₂ Si (OH) ₂ + 2CH ₃ OH

In the above synthesis, but was used DMDMS alkoxysilane is mixed with orthophosphoric acid, the following general formula _{^{R α n Si (OR β)}} 4-n
(R ^α is an organic group represented by C _k H _{2k + 1} − (where k is 1 or 2), and R ^β is C _m H _2m−1 − (where m is 1, 2, an organic group represented by 3, 4 or 5 a is), if R ^alpha there are a plurality, each Rα can be different may be the same, if the R ^beta there are a plurality, each ^Rβ may be the same or different, and n is an integer of 0 to 3.)
You may use the alkoxysilane represented by these.

In addition, if the content of phosphoric acid H ₃ PO ₄ is too large, the viscosity increases and a problem that it becomes impossible to cast to an ultraviolet LED occurs. It is preferable that it is 1-20 mass parts, and it is more preferable that it is 0.2-15 mass parts.

  Examples of the curing catalyst include bis (lauroxydibutyltin) oxide, metal organic compounds such as alkoxides of one or more metals selected from Al, Zr, Nb, and Ta, and amines such as monoethanolamine. .

[Preparation of curable resin composition]
The method for preparing the curable resin composition of the present invention is not particularly limited, and can be appropriately prepared by a known method as long as it is a method capable of uniformly mixing an alkoxy oligomer and a silicone resin and, if desired, a curing catalyst. .
For example, the curable resin composition of the present invention is prepared by mixing the above-described alkoxy oligomer and silicone resin, and optionally a curing catalyst, for a predetermined time and further defoaming. can do.

[Curing of curable resin composition]
Since the curable resin composition of the present invention is usually in a liquid state at room temperature, when used as a sealing material for an ultraviolet LED, a predetermined amount is cast into the package of the ultraviolet LED and heated for a predetermined time. Dry and cure.
The heating condition is not particularly limited as long as the curable resin composition can be set to a desired curing condition. For example, it is desirable to heat at 100 ° C. to 200 ° C. for about 1 hour to 2 hours.

In the curable resin composition of the present invention, the amount of cure shrinkage of the solidified product obtained by curing is preferably 10% by mass or less, more preferably 9% by mass or less, and more preferably 8% by mass or less. More preferred.
The curable resin composition of the present invention contains a silicone resin together with an alkoxy oligomer as an essential component, so that even when used for sealing an ultraviolet LED to which a large amount of power is applied, the curing shrinkage during curing is effective. Can be suppressed.

In addition, in this application document, the amount of cure shrinkage means the value calculated | required by a following formula from the mass before and behind heating when a curable resin composition is heat-processed and hardened | cured.
Curing shrinkage (mass%) = {(mass of curable resin composition before curing (g) −mass of solidified body after curing (g)) / mass of curable resin composition before curing (g)} × 100

In the curable resin composition of the present invention, when the solidified product obtained by curing is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 500 hours, the transmittance of the solidified product to the ultraviolet light is 85%. It is preferable that the transmittance of the solidified body with respect to the ultraviolet light is 87.5% or more, and the transmittance of the solidified body with respect to the ultraviolet light is more preferably 90% or more. .

Further, the curable resin composition of the present invention has a transmittance of the solidified body with respect to the ultraviolet light when the solidified body obtained by curing is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 1000 hours. It is preferably 85% or more, more preferably a transmittance of the solidified body with respect to the ultraviolet light is 87.5% or higher, and a transmittance of the solidified body with respect to the ultraviolet light of 90% or higher. Further preferred.

Furthermore, when the curable resin composition of the present invention is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 5000 hours, the solidified material obtained by curing has a transmittance with respect to the ultraviolet light of the solidified material. It is preferably 80% or more, more preferably a transmittance of the solidified body with respect to the ultraviolet light is 85% or more, and further preferably a transmittance of the solidified body with respect to the ultraviolet light of 90% or more. .

Examples of the ultraviolet light having an emission intensity of 100 W / cm ² include those having an emission peak wavelength of 365 nm.

  Even when the curable resin composition of the present invention is used for sealing an ultraviolet LED to which a large electric power is applied, it can suppress the occurrence of cracks, peeling and coloring, and can suppress curing shrinkage. Therefore, the excellent transmittance as described above can be easily achieved.

  As described above, according to the present invention, compared with the conventional curable resin composition, the transparency, ultraviolet resistance and heat resistance in the ultraviolet region are extremely high, and the sealing of the ultraviolet LED that applies high power is performed. Even if it uses it for optical element material, it can provide the curable resin composition which can suppress generation | occurrence | production of a crack, peeling, and coloring, and can suppress cure shrinkage.

[Optical element]
Next, the optical element of the present invention will be described.
The optical element of the present invention comprises a cured product of the curable resin composition of the present invention.
The details of the effective resin composition of the present invention are as described above.
Examples of the optical element of the present invention include those selected from lenses (biconvex lenses, biconcave lenses, convex / concave lenses, planoconvex lenses, planoconcave lenses, cylindrical lenses, etc.), prisms, rods, diffraction gratings, and the like.
The optical element according to the present invention includes, for example, the curable resin composition of the present invention in a lower mold of a pair of molds composed of an upper mold and a lower mold having a molding surface shape corresponding to the optical element shape to be obtained. By filling and pressing the upper mold from the upper part, a preform of the optical element can be formed, and then it can be produced by curing. The details of the curing treatment conditions are the same as the method described in the above section [Curing of curable resin composition].
According to the present invention, the transparency, ultraviolet resistance and heat resistance in the ultraviolet region are extremely high compared to conventional resin optical elements, and even if used as a light source that emits ultraviolet light of high light intensity, Further, it is possible to provide an optical element that can suppress the occurrence of coloring and coloring, and can suppress curing shrinkage.

[Optical semiconductor device]
Next, the optical semiconductor device of the present invention will be described.
An optical semiconductor device of the present invention is characterized by having at least one of an optical semiconductor element sealed with the curable resin composition of the present invention and an optical element of the present invention. And those emitting light in the ultraviolet region.
Hereinafter, an apparatus configuration example of the optical semiconductor device of the present invention will be described based on embodiments of the curable resin composition of the present invention.
As described above, the curable resin composition of the present invention can be suitably used as, for example, a sealing material for an ultraviolet LED that applies high power.
FIG. 1 is a schematic configuration diagram (cross-sectional view) showing an example when the curable resin composition of the present invention is applied to a surface-mount ultraviolet LED 100. FIG. 2 is a schematic configuration diagram (cross-sectional view) showing an example when the curable resin composition of the present embodiment is applied to a package type ultraviolet LED 200.

  As shown in FIG. 1, the ultraviolet LED 100 includes a substrate 101, an LED die 103, and the like. The substrate 101 is a so-called wiring substrate made of an insulating base material (for example, ceramic (aluminum nitride, alumina, silicon nitride, silicon carbide, etc.)). As shown in FIG. 1, a positive electrode pattern 102 a and a negative electrode pattern 102 b made of a conductive metal material (for example, copper or aluminum) are formed on the surface of the substrate 101.

  The LED die 103 has a quadrangular prism shape, and includes a cathode terminal (not shown) on the upper surface (that is, the emission surface 103a) and an anode terminal (not shown) on the lower surface. The lower surface (that is, the anode terminal) of the LED die 103 and the positive electrode pattern 102a are mechanically and electrically bonded via a die bonding agent (not shown). Further, the cathode terminal on the upper surface of the LED die 103 is electrically bonded to the negative electrode pattern 102 b through the bonding wire 104. When a current is applied between the anode terminal and the cathode terminal via the positive electrode pattern 102a and the negative electrode pattern 102b, ultraviolet light (for example, light having a wavelength of 365 nm) is generated in the light emitting layer (not shown) inside the LED die 103. The light is emitted from the emission surface 103a.

  A frame member 105 is provided around the LED die 103, and the LED die 103 inside the frame member 105 is sealed with the solidified body 106 of the curable resin composition of the present embodiment.

  As a method for manufacturing the ultraviolet LED 100 shown in FIG. 1, the LED die 103 is die-bonded to the positive electrode pattern 102a, the cathode terminal of the LED die 103 and the negative electrode pattern 102b are wire-bonded by the bonding wire 104, The method of making it harden | cure by filling the curable resin composition of this invention inside and heating at 100 to 200 degreeC for about 1 to 2 hours can be illustrated.

  In the ultraviolet LED 200 shown in FIG. 2, the cathode terminal (not shown) and the anode terminal (not shown) of the LED die 203 are formed on the upper surface (that is, the emission surface 203a) of the LED die 203, and the LED die 203 is the case 210. 1 and the point that the solidified body 207 is provided on the solidified body 206 of the curable resin composition of the present invention is different from the ultraviolet LED 100 shown in FIG.

  As shown in FIG. 2, the ultraviolet LED 200 includes a case 210, an LED die 203, and the like. The case 210 is a bowl-shaped member formed from an insulating material (for example, ceramic). As shown in FIG. 2, the bottom 210a of the case 210 is provided with a positive electrode pattern 202a and a negative electrode pattern 202b that are formed so as to be drawn from the inside of the case 210 to the outside.

  The LED die 203 has a quadrangular prism shape, and includes a cathode terminal (not shown) and an anode terminal (not shown) on the upper surface (that is, the emission surface 203a). The lower surface of the LED die 203 is fixed to the bottom 210a of the case 210 via a die bond agent (not shown). The cathode terminal on the upper surface of the LED die 203 is electrically bonded to the positive electrode pattern 102a via the bonding wire 204a, and the anode terminal on the upper surface of the LED die 203 is connected to the positive electrode pattern 202b via the bonding wire 204b. Electrically joined. When a current is applied between the anode terminal and the cathode terminal via the positive electrode pattern 202a and the negative electrode pattern 202b, ultraviolet light (for example, light having a wavelength of 365 nm) is generated in the light emitting layer (not shown) inside the LED die 203. The light is emitted from the emission surface 203a.

  The LED die 203 is surrounded by the wall surface of the case 210, and the LED die 203 inside the case 210 is sealed with the solidified body 206 of the curable resin composition of the present invention. On the solidified body 206, a solidified body 207 of another curable resin composition having a refractive index and an elastic modulus different from those of the curable resin composition of the present invention is formed.

  2, the LED die 203 is die-bonded in a case 210, and the anode terminal and the cathode terminal of the LED die 203 are bonded to the positive electrode pattern 202a and the negative electrode pattern 202b by bonding wires 204a and 204b, respectively. Next, the inside of the case 210 is filled with the curable resin composition of the present embodiment, and is cured by heating at 100 ° C. to 200 ° C. for about 1 hour to 2 hours. An example is a method in which a curable resin composition is filled and cured by heating at a predetermined temperature for a predetermined time.

  As described above, according to the present invention, compared with the conventional curable resin composition, the transparency, ultraviolet resistance and heat resistance in the ultraviolet region are extremely high, and the sealing of the ultraviolet LED that applies high power is performed. Even if it uses it for optical element material, the optical semiconductor device using the curable resin composition which can suppress generation | occurrence | production of a crack, peeling, and coloring and can suppress hardening shrinkage can be provided.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further, this invention is not limited to the following Example, unless the summary is exceeded.

[Example 1]
(Cure catalyst synthesis)
Z-6329 manufactured by Toray Dow Corning Co., Ltd. (chemical name: dimethyldimethoxysilane (DMDMS), characteristic formula: (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , molecular weight: 120.2) cooled in an ice bath While stirring 100.00 g, 25.93 g of an orthophosphoric acid (formula: H ₃ PO ₄ ) aqueous solution (H ₃ PO ₄ concentration: 85%) was added dropwise over 15 minutes, and the mixture was further mixed at room temperature for 1 hour. Then, a phosphoric acid-based curing catalyst H ₃ PO ₄ was obtained.
In addition, although orthophosphoric acid contains 15 mass% of H ₂ O, the following chemical reaction formula (CH ₃ ) ₂ Si (OCH ₃ ) ₂ + 2H ₂ O → (CH ₃ ) ₂ Si (OH) ₂ + 2CH ₃ OH
As shown in FIG. ₂ , H ₂ O reacts with the methoxy group (CH ₃ O—) of DMDMS and is completely consumed. The concentration of the curing catalyst H ₃ PO ₄ contained in this liquid is 17.5% by mass.

(Preparation of curable resin composition)
Trifunctional structural unit (the structural unit represented by the general formula (3), the structural unit represented by the general formula (5), wherein a is 1, the structural unit represented by the general formula (6) Made of Shin-Etsu Chemical Co., Ltd., which is liquid at room temperature (25 ° C.), consisting only of a structural unit in which b is 1 and one or more structural units selected from structural units represented by general formula (7). Silicone alkoxy oligomer X-40-9225 (containing only methyl group as organic group, containing only methoxy group as alkoxy group, 24% by mass of alkoxy group, 67% by mass of SiO ₂ component, total amount of O atoms / Si atom 40.0 g in which the atomic ratio represented by the total amount is 3.0 and Tn / (Dn + Tn) = 100) is added to a trifunctional structural unit (the structural unit represented by the general formula (10), the general formula ( 12) among the structural units represented by 12) 1 or more than one structural unit selected from the structural unit represented by general formula (13) and the structural unit represented by general formula (14). Silicone resin KR-220LP manufactured by Shin-Etsu Chemical Co., Ltd., which is solid at room temperature (25 ° C.) (containing only methyl groups as organic groups, non-volatile content is 99.0% by mass, and the amount of hydroxyl groups is 3.0% by mass) 1) 60.0 g was added and dissolved by stirring for 30 minutes using a revolution / spinning mixer (ARE-250, manufactured by Shinky Co., Ltd.), then 0.20 g of the phosphoric acid curing catalyst was added, and 1 By stirring for a minute, a transparent viscous liquid was obtained.
Then, this viscous liquid was transferred to a glass container for a rotary evaporator, and defoamed for 3 minutes using a revolution / spinning mixer. Thereafter, a glass container containing a viscous liquid was attached to the rotary evaporator, and the pressure was reduced for 30 minutes while heating at 50 ° C., and methanol generated by the reaction between the silicone alkoxy oligomer X-40-9225 and the silicone resin KR-220LP. , H ₂ O was distilled off to obtain a transparent homogeneous viscous liquid (curable resin composition).

(Production of solidified body)
The obtained liquid is cast in a petri dish made of perfluoroalkoxy fluororesin (PFA) having an inner diameter of 50 mm and a height of 12 mm so that a solidified body having a thickness of 1 mm can be obtained, and sequentially at 110 ° C. for 2 hours and at 150 ° C. for 2 hours. A solidified body having a thickness of 1 mm was obtained by the heat treatment to be held.

[Example 2]
25.0 g of a silicone alkoxy oligomer X-40-9225 manufactured by Shin-Etsu Chemical Co., Ltd., which is liquid at room temperature (25 ° C.) used in Example 1, is represented by a trifunctional constituent unit (general formula (10)). Structural unit, structural unit in which d is 1 among structural units represented by general formula (12), structural unit in which e is 1 among structural units represented by general formula (13), and general formula (14) Silicone resin KR-220L manufactured by Shin-Etsu Chemical Co., Ltd., which is solid at room temperature (25 ° C.) consisting of only one or more structural units selected from the structural units represented by 79.0 g) was added and dissolved by stirring at 100 ° C. for 3.5 hours to obtain a transparent viscous liquid.
To the obtained viscous liquid, 1.25 g of the phosphoric acid catalyst used in Example 1 was added and mixed for 2 minutes by a revolution / spinning mixer to obtain a transparent homogeneous liquid (curable resin composition).
The obtained liquid was cast into a PFA petri dish in the same manner as in Example 1 and cured by a heat treatment of sequentially holding at 60 ° C. for 2 hours, 110 ° C. for 2 hours, and 150 ° C. for 2 hours to obtain a solidified body having a thickness of 1 mm. Got.

[Example 3]
As an alkoxy oligomer, when all the structural units constituting the alkoxy oligomer are 100 mol%, a bifunctional structural unit (a structural unit represented by the general formula (2), a structural unit represented by the general formula (5)) 46 mol% of trifunctional structural units (one or more structural units selected from structural units in which a is 2 and structural units in which b is 0 among the structural units represented by formula (6)). Among the structural units represented by the general formula (3), the structural unit represented by the general formula (5), the structural unit in which a is 1, and the structural unit represented by the general formula (6) in which b is 1. Silicone alkoxy oligomer X manufactured by Shin-Etsu Chemical Co., Ltd., which is liquid at room temperature (25 ° C.), containing 54 mol% of a certain structural unit and one or more structural units selected from structural units represented by the general formula (7) -40-9246 (as organic group Containing only methyl group, containing only a methoxy group as an alkoxy group, the amount of alkoxy group is 12 wt%, SiO ₂ minutes 72 wt%, the atomic ratio represented by the total amount of the total amount / Si atom of O atoms is 2.5 , Tn / (Dn + Tn) = 0.54), 50.0 g of a solid resin Resin KR-220L manufactured by Shin-Etsu Chemical Co., Ltd. at room temperature (25 ° C.) used in Example 2 A transparent homogeneous liquid (curable resin composition) was obtained in the same manner as in Example 2 except that 2.5 g of the phosphoric acid catalyst used in Example 1 was used, and then a solidified body having a thickness of 1 mm was obtained. It was.

[Example 4]
In Example 2, 80.0 g of silicone alkoxy oligomer X-40-9225 manufactured by Shin-Etsu Chemical Co., Ltd., which is liquid at room temperature (25 ° C.), manufactured by Shin-Etsu Chemical Co., Ltd. which is solid at room temperature (25 ° C.) A transparent homogeneous liquid (curable resin composition) was obtained in the same manner as in Example 2 except that 20.0 g of silicone resin KR-220L and 4.0 g of phosphoric acid catalyst were used, and then solidified with a thickness of 1 mm. Got the body.

[Example 5]
In Example 2, the mixing amount of the silicone alkoxy oligomer X-40-9225 manufactured by Shin-Etsu Chemical Co., Ltd. was changed from 25.0 g to 50.0 g, and instead of the silicone resin KR-220L, a trifunctional structural unit ( Among structural units represented by general formula (10), structural unit represented by general formula (12), d is 1, and among structural units represented by general formula (13), e is 1. Silicone resin manufactured by Momentive Performance Materials Japan G.K., which is solid at room temperature (25 ° C.), consisting of only one structural unit and one or more structural units selected from structural units represented by the general formula (14). Except for using 50.0 g of YR3370 (containing only a methyl group as an organic group, having a nonvolatile content of 99.5% by mass and a hydroxyl group amount of 1.5% by mass), Example 2 In the like, to obtain a transparent homogeneous liquid (curable resin composition), and then to obtain a solid material having a thickness of 1 mm.

[Example 6]
In Example 2, a mixed amount of silicone alkoxy oligomer X-40-9225 manufactured by Shin-Etsu Chemical Co., Ltd. that is liquid at room temperature (25 ° C.) was 50.0 g, and Shin-Etsu Chemical Co., Ltd. that was solid at room temperature (25 ° C.) ( Co., Ltd. The amount of silicone resin KR-220L manufactured was changed to 50.0 g, and bis (lauroxydibutyltin) oxide 0.50 g was used instead of the phosphoric acid catalyst. A transparent homogeneous liquid (curable resin composition) was obtained, and then a solidified body having a thickness of 1 mm was obtained.

[Comparative Example 1]
In Example 2, 90.0 g of silicone alkoxy oligomer X-40-9225 manufactured by Shin-Etsu Chemical Co., Ltd., which is liquid at room temperature (25 ° C.), manufactured by Shin-Etsu Chemical Co., Ltd. which is solid at room temperature (25 ° C.) A transparent homogeneous liquid (curable resin composition) was obtained in the same manner as in Example 2 except that 10.0 g of silicone resin KR-220L and 4.5 g of phosphoric acid catalyst were used, and then solidified with a thickness of 1 mm. Got the body.

[Comparative Example 2]
In Example 2, 15.0 g of silicone alkoxy oligomer X-40-9225 manufactured by Shin-Etsu Chemical Co., Ltd., which is liquid at room temperature (25 ° C.), manufactured by Shin-Etsu Chemical Co., Ltd., which is solid at room temperature (25 ° C.) A transparent homogeneous liquid (curable resin composition) was obtained in the same manner as in Example 2 except that 85.0 g of silicone resin KR-220L and 0.75 g of phosphoric acid catalyst were used, and then solidified with a thickness of 1 mm. Got the body.

[Evaluation / Measurement]
About each curable resin composition obtained in Examples 1 to 6 and Comparative Examples 1 to 2, measurement of the amount of curing shrinkage, evaluation of remeltability after curing, transmittance by the methods described below Measurement and UV resistance evaluation were performed. The results are shown in Tables 1 and 2.

(Measurement of cure shrinkage)
The amount of cure shrinkage was calculated by the following formula from the mass before and after heating when the curable resin composition was heat-treated and cured.
Curing shrinkage (mass%) = {(mass of curable resin composition before curing (g) −mass of solidified body after curing (g)) / mass of curable resin composition before curing (g)} × 100
In addition, the measurement result of hardening shrinkage amount was shown as "curing shrinkage amount" in Table 1 and Table 2, and the thing below 10 mass% was set as the pass.

(Evaluation of remeltability after curing)
The solidified body of each curable resin composition obtained in Examples 1 to 6 and Comparative Examples 1 to 2 was heated on a hot plate at 120 ° C., 150 ° C. and 180 ° C. for 5 minutes, It was evaluated by visually confirming whether the solidified body was softened or deformed.
The evaluation results are shown in Tables 1 and 2 as “presence / absence of remelting after curing”, “no” when the solidified body was not softened / deformed, and those where the solidified body was softened / deformed. “Yes”.

(Transmittance measurement / evaluation)
The transmittance of the solidified body of each sealing material (curable resin composition) is measured in the wavelength range of 250 to 550 nm using an ultraviolet-visible spectrophotometer U-4100 manufactured by Hitachi Technologies, Ltd. It was. And the transmittance | permeability which becomes the minimum in the wavelength range of 300-350 nm was evaluated.

FIG. 3 is a graph showing an example of the transmittance measurement result, and shows the transmittance measurement result of the solidified body of the curable resin composition obtained in Example 1 above.
In Example 1, the minimum transmittance in the wavelength range of 300 to 350 nm was evaluated as 90.0% from FIG. Thus, the results of obtaining the minimum transmittance in the wavelength range of 300 to 350 nm from the transmittance measurement results of the respective sealing materials (curable resin compositions) are shown in Tables 1 and 2 as “Tmin ₃₀₀ ”. _-350 ". In addition, what made "Tmin _300-350 " 85% or more was set as the pass.

(UV resistance evaluation)
Package type UV LED manufactured by Nichia Corporation with the glass window removed: NC4U133B (emission peak wavelength: 365 nm) is mounted on an aluminum star substrate, and the star substrate is made of Teflon (registered trademark). It screwed to the heat sink made from aluminum through the spacer. Then, a current of about 1.0 A is applied to the package type ultraviolet LED to emit ultraviolet light of about 100 W / cm ² , and a Teflon (registered trademark) spacer so that the junction temperature (Tj) becomes 100 ° C. The thickness of was adjusted.
The junction temperature was measured using a thermal resistance measuring device AT-205 manufactured by Yuasa Electronics Co., Ltd.
The curable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 2 were filled as the sealing materials in the recesses of the package type ultraviolet LED, respectively, and left to solidify at room temperature. Thereafter, the temperature was raised to 150 ° C., and kept at 150 ° C. for 1 hour for drying.
The sealed package type UV LED is continuously lighted by supplying a current of 1.0 A, and continuously using an integrating sphere (manufactured by Labsphere, model number: 3P-GPS-020-SL, inner diameter: 2 inches). The emission intensity was measured.
For measurement of the luminescence intensity, a UV integrated light meter UIT-150 manufactured by Ushio Electric Co., Ltd. and a UVD-S365 light receiver for UV integrated light meter were used. Since the LED has the property that the light emission intensity decreases with the passage of lighting time, the sealing material (curable resin composition) is not sealed together with the sealed package type ultraviolet LED in the ultraviolet resistance evaluation of the sealing material (curable resin composition). The package type ultraviolet LED was continuously lit under the same conditions, and the light emission intensities of both were relatively compared over 5000 hours.
As will be described later, in the UV resistance evaluation, the emission intensity after 500 hours (correction value), the emission intensity after 1000 hours (correction value), and the emission intensity after 5000 hours (correction value). It was determined that the light emission intensity (correction value) after at least 500 hours passed was 85% or more.

FIG. 4 is a graph showing an example of the change over time of the emission intensity, and shows the change over time of the emission intensity of the solidified product of the curable resin composition obtained in Example 1. In FIG. 4, a graph indicated by “◯” and a dotted line is a graph showing a change with time (actually measured value) of the emission intensity of the solidified product of the curable resin composition obtained in Example 1, immediately after the LED is turned on. The relative intensity is shown with the emission intensity as 100%.
In FIG. 4, the graph indicated by “●” and the solid line is obtained by correcting the measured value indicated by “◯” and the dotted line in consideration of the light emission intensity of the unsealed package type ultraviolet LED (correction value). Specifically, it shows the correction value for the emission intensity of the unsealed package type UV LED. That is, the graph (that is, the correction value) indicated by “●” and the solid line indicates the ultraviolet light that passes through the solidified body of the sealing material (curable resin composition) with respect to the emission intensity of the unsealed package type ultraviolet LED. The ratio of the light emission intensity of the solidified body of the sealing material (curable resin composition) with respect to the ultraviolet light is shown.

From FIG. 4, the solidified product of the curable resin composition obtained in Example 1 has an emission intensity (correction value) of 95% or more after 500 hours and an emission intensity (correction value) of 95% after 1000 hours. The emission intensity (correction value) after lapse of 5000% or more for 5000 hours was evaluated as 95% or more.
Thus, from the measurement result of the light emission intensity of the LED encapsulated with each of the encapsulants (curable resin composition), the light emission intensity (correction value) after 500 hours and the light emission after 1000 hours have elapsed. The results of calculating the intensity (correction value) and the emission intensity after 5000 hours (correction value) are shown in Tables 1 and 2 as UV resistance (1) (the emission intensity after 500 hours (correction value)). ), UV resistance (2) (light emission intensity after 1000 hours (correction value)) and UV resistance (3) (light emission intensity after 5000 hours (correction value)).
As for the acceptance criteria of the UV resistance evaluation of this example, the emission intensity (correction value) after at least 500 hours (that is, the transmittance of ultraviolet light after 500 hours) is 85% or more. However, the acceptance criteria for UV resistance evaluation can be appropriately changed according to the specifications required for the LED, more preferably 87.5% or more, and more preferably 90% or more. preferable.
In addition, as an acceptance criterion for UV resistance evaluation, it is possible to add emission intensity (correction value) after 1000 hours (that is, ultraviolet light transmittance after 1000 hours). In this case, the light emission intensity (correction value) after 1000 hours is preferably 85% or more, more preferably 87.5% or more, and further preferably 90% or more.
Furthermore, it is also possible to add the emission intensity (correction value) after 5000 hours (that is, the transmittance of ultraviolet light after 5000 hours) as an acceptance criterion for ultraviolet resistance evaluation. In this case, the light emission intensity (correction value) after lapse of 5000 hours is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.
After the evaluation of the ultraviolet resistance, no cracks, peeling, or coloring was confirmed in the solidified bodies of the curable resin compositions (sealing materials) obtained in Examples 1 to 6.

As shown in Tables 1 and 2, the curable resin compositions obtained in Examples 1 to 6 are both 20 to 85% by mass of a specific alkoxy oligomer that is liquid at room temperature and a solid that is solid at room temperature. 15 to 80% by mass of a silicone resin.
For this reason, even if each said curable resin composition is used for sealing of ultraviolet LED which applies a big electric power, since cure shrinkage amount is suppressed with 10 mass% or less, cure shrinkage can be suppressed suitably. It turns out that it is a thing. Further, “Tmin _300-350 ” is 85% or more, “luminescence intensity after 500 hours (correction value)” (that is, “ultraviolet light resistance (1)”) and “luminescence intensity after 1000 hours”. (Correction value) ”(that is,“ UV resistance (2) ”) is 90% higher, and“ luminescence intensity (correction value) after 5000 hours ”(that is,“ UV resistance 3) ”is any Since the curable resin composition obtained in Examples 1 to 6 is used as a sealing material, the transparency in the ultraviolet region, the ultraviolet resistance and the heat resistance are extremely high. It turns out that it is expensive.

  The sealing material (curable resin composition) of Comparative Example 1 has a silicone resin content of as small as 10.0% by mass, so that the cure shrinkage is as large as 11.5% by mass and it is difficult to suppress cure shrinkage. It turns out that it is.

  Moreover, since the sealing material (curable resin composition) of Comparative Example 2 has a low alkoxy oligomer content ratio of 15% by mass and a high silicone resin content ratio relative to the alkoxy oligomer, it has thermoplastic properties. It turns out that it will remain and it will remelt by the heat_generation | fever of ultraviolet LED.

  The embodiments and examples of the present invention have been described above. However, the present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. .

  For example, in the description of the embodiment of the present invention, as the use of the curable resin composition, the sealing of the ultraviolet LED was mentioned, but the use of the curable resin composition is not limited to this, for example, , Sealing of light emitting elements used in other semiconductor light emitting devices (photo semiconductor devices) such as laser diodes, photodetectors, electro-optical displays, organic semiconductors, organic light emitting diodes, electroluminescent displays, organic solar cell devices, lighting devices, etc. It can also be used as a stop material and a material for optical elements such as lenses, prisms, rods, and diffraction gratings.

  In addition, it should be understood that the embodiment disclosed this time is illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

100, 200 UV LED
101 Substrate 102a, 202a Positive electrode pattern 102b, 202b Negative electrode pattern 103, 203 LED die 103a, 203a Emission surface 104, 204a, 204b Bonding wire 105 Frame material 106 Solidified body 210 Case 210a Bottom

  According to the present invention, compared with the conventional curable resin composition, the transparency in the ultraviolet region, the ultraviolet resistance and the heat resistance are extremely high. An optical element and an optical semiconductor composed of a cured product of the curable resin composition, which can provide a curable resin composition that can suppress generation of cracks, peeling, and coloring, and can suppress curing shrinkage even when used. An apparatus can be provided.

Claims (12)

20 to 85% by mass of an alkoxy oligomer that is liquid at room temperature, and 15 to 80% by mass of a silicone resin that is solid at room temperature,
The alkoxy oligomer has an organopolysiloxane structure,
The following general formula (1)
(R ¹ R ² R ³ SiO _1/2 ) (1)
(Wherein R ¹ , R ² and R ³ are each independently the same or different organic groups),
The following general formula (2)
(R ⁴ R ⁵ SiO _2/2 ) (2)
(Wherein R ⁴ and R ⁵ are independent, the same or different organic groups),
The following general formula (3)
(R ⁶ SiO _3/2 ) (3)
(Wherein R ⁶ is an organic group) and the following general formula (4)
(SiO _4/2 ) (4)
And having one or more structural units selected from structural units represented by:
The following general formula (5)
(R ⁷ _a (OR ⁸ ) _3-a SiO _1/2 ) (5)
(However, a is 0, 1 or 2, and R ⁷ and R ⁸ are independent, the same or different organic groups, and when a plurality of R ⁷ or R ⁸ are contained, each R ⁷ Or R ⁸ may be the same or different from each other.)
The following general formula (6)
(R ⁹ _b (OR ¹⁰ ) _2-b SiO _2/2 ) (6)
(However, b is 0 or 1, R ⁹ and R ¹⁰ are each independently the same or different organic groups, and when a plurality of R ¹⁰ are contained, each R ¹⁰ is the same as each other. And may be different from each other.) And the following general formula (7)
((OR ¹¹ ) SiO _3/2 ) (7)
(Wherein R ¹¹ is an organic group), having one or more structural units selected from the structural units represented by:
When all the siloxane units constituting the alkoxy oligomer are 100 mol%, 90 to 100 mol% of one or more structural units selected from the structural units represented by the general formula (1) to the general formula (7) are included. A curable resin composition characterized by the above.   The curable resin composition according to claim 1, comprising 0.1 to 20 parts by mass of phosphoric acid as a curing catalyst with respect to 100 parts by mass of the total amount of the alkoxy oligomer and the silicone resin.   The curable resin composition according to claim 1 or 2, wherein the alkoxyl group content in the alkoxy oligomer is 10 to 30% by mass.   The curable resin composition according to any one of claims 1 to 3, wherein a curing shrinkage amount of a solidified body obtained by curing the curable resin composition is 10% by mass or less. When the solidified body obtained by curing the curable resin composition is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 500 hours, the transmittance of the solidified body to the ultraviolet light is 85% or more. The curable resin composition as described in any one of Claims 1-4. When the solidified body obtained by curing the curable resin composition is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 1000 hours, the transmittance of the solidified body to the ultraviolet light is 85% or more. The curable resin composition as described in any one of Claims 1-4. When the solidified material obtained by curing the curable resin composition is irradiated with ultraviolet light having an emission intensity of 100 W / cm ² for 5000 hours, the transmittance of the solidified material to the ultraviolet light is 80% or more. The curable resin composition as described in any one of Claims 1-4.   The curable resin composition according to any one of claims 1 to 7, wherein an emission peak wavelength of the ultraviolet light is 365 nm.   An optical element comprising a cured product of the curable resin composition according to any one of claims 1 to 8.   An optical semiconductor device comprising an optical semiconductor element sealed with the curable resin composition according to claim 1.   An optical semiconductor device comprising the optical element according to claim 9.   The optical semiconductor device according to claim 10, wherein the optical semiconductor element emits light in an ultraviolet region.