JP5109873B2 - Thermosetting resin composition - Google Patents

Description

  The present invention relates to a thermosetting resin composition used by thermosetting. More specifically, thermosetting is suitably used as an optical electronic member such as an optical semiconductor sealant, an electronic circuit sealant, an optical waveguide, an optical communication lens, an organic EL element sealant, and an optical film. The present invention relates to a resin composition.

  In recent years, for higher output and shorter wavelength of light sources using light-emitting diodes (LEDs) and other optical semiconductors, flat panel displays using liquid crystal, organic EL, etc. have higher definition, higher image quality, and higher viewing angle. Furthermore, the performance of optical and electronic parts has been remarkably advanced, such as higher frequency of electronic circuits and circuits / communications using light. Conventionally, thermosetting resin compositions using polysiloxane compounds (hereinafter abbreviated as polysiloxane compositions) have been used in applications in these fields (see, for example, Patent Documents 1 and 2). However, polysiloxane compositions generally have a surface tack due to their low hardness, and there is a problem that foreign matter adheres to the surface or a portion receiving a strong light amount such as a light emitting surface is damaged. .

  In order to solve this problem, it is conceivable to introduce an epoxy resin curing system by introducing a rigid component into the polysiloxane composition. In order to apply an acid / epoxy resin curing system to a thermosetting resin composition having a polysiloxane skeleton, a technique for introducing an acid-modified site or an epoxy-modified site into polysiloxane is known. For example, Patent Document 3 discloses a resin composition in which a commercially available epoxy resin and an acid anhydride curing agent are each introduced into a molecular chain and an epoxy-modified polysiloxane and an acid anhydride-modified polysiloxane are blended. When the resin composition according to this disclosed technique is used, the problem of surface tack is solved, but the proportion of polysiloxane is relatively reduced, causing problems in light resistance, and high output in a short wavelength region. It is difficult to meet strict light resistance requirements recently required such as sealing of light emitting elements.

  On the other hand, a cage-type silsesquioxane has been studied as a substance having a hard structure while having a siloxane skeleton having high light resistance and heat yellowing resistance, and has been attempted to be applied to fields such as electronics and photonics. For example, Patent Document 4 discloses a resin composition comprising an epoxy ring-containing silsesquioxane, an epoxy resin, an acid anhydride curing agent, and a curing catalyst. According to this disclosed technology, the problem of surface tack is solved and the resin composition is excellent in light resistance. However, since an acid anhydride is used as a curing agent, whitening of the cured product and reduction in heat yellowing are reduced. May occur.

Thus, there is a need for a thermosetting resin composition that improves surface non-tackiness while taking advantage of the excellent light resistance of polysiloxane and is excellent in light resistance and heat yellowing resistance.
JP 2001-2922 A (pages 2 and 6) JP 2004-186168 A (page 2, page 3 and page 7) Japanese Patent Laid-Open No. 06-306084 (pages 2 and 13) Japanese Patent Laying-Open No. 2005-263869 (page 2, page 3 and page 13)

  Therefore, the object of the present invention is that the cured product has good surface non-tackiness, is transparent, excellent in light resistance and heat-resistant yellowing, and is used for demanding applications such as sealing of light-emitting elements with high output in a short wavelength region. It is in providing the thermosetting resin composition which can also be used.

  In order to achieve the above object, the thermosetting resin composition of the first invention in the present invention contains the following components (A) and (B), and the ratio of the contents of both components is based on mass. And component (A): component (B) = 20: 80 to 80:20.

  Component (A): A carboxyl group-containing polysiloxane having a plurality of carboxyl groups and having a structure represented by the following formula (1).

〔式（１）中、ａは０〜５０の整数、ｂは３〜３００の整数であり、Ｒ^１は炭素数が１〜６のアルキル基、Ｘ^１は下記式（２）又は−（ＣＨ_２）_ｎ−ＣＯＯＨ（但し、ｎは１〜２０の整数）で表される置換基であり、Ｘ^２はＲ^１又は下記式（２）で表される置換基であり（但し、ａ＝０のときＸ^２≠Ｒ^１）、Ｒ^１とＸ^１はそれぞれ同一でも異なっていてもよい。〕

Wherein (1), a is an integer of 0 to 50, b is an integer of 3 to 300, ^{R 1} is an alkyl group having 1 to 6 carbon atoms, ^{X 1} is the following formula (2) or - (CH _{2) n} -COOH (where, n is a substituent represented by an integer) of 1 to 20, ^{X 2} is a substituent represented by ^{R 1} or the following formula (2) (where, a = 0 X ² ≠ R ¹ ), R ¹ and X ¹ may be the same or different. ]

〔式（２）中、Ｒ^２は炭素数が１〜１０のアルキレン基又はアルキレンオキシアルキレン基、ｋは０又は１である。〕
成分（Ｂ）：脂環式エポキシ基を複数個有し、下記式（３）で示される構造を有する脂環式エポキシ基含有かご型シルセスキオキサン。

Wherein (2), ^{R 2} is an alkylene group or alkylene oxyalkylene group having 1 to 10 carbon atoms, k is 0 or 1. ]
Component (B): An alicyclic epoxy group-containing cage silsesquioxane having a plurality of alicyclic epoxy groups and having a structure represented by the following formula (3).

〔式（３）中、Ｒ^６は炭素数が１〜１０のアルキレン基又はアルキレンオキシアルキレン基、Ｒ^７は炭素数が１〜１０のアルキレン基又はアルキレンオキシアルキレン基、Ｒ^８は炭素数が１〜４のアルキル基、Ｒ^９は炭素数が１〜４のアルキル基、ｍは１〜３の整数、Ｒ^５は置換又非置換のアルキル基、ｒは６、８、１０及び１２から選ばれた数、ｐは２〜ｒの整数及びｑは０〜（ｒ−ｐ）の整数を表す。〕

[In Formula (3), R ⁶ is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, R ⁷ is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, and R ⁸ is 1 carbon atom. ˜4 alkyl group, R ⁹ is an alkyl group having 1 to 4 carbon atoms, m is an integer of 1 to 3, R ⁵ is a substituted or unsubstituted alkyl group, r is selected from 6, 8, 10 and 12. P, an integer of 2 to r, and q represents an integer of 0 to (rp). ]

According to the present invention, the following effects can be exhibited.
The thermosetting resin composition of the first invention contains a carboxyl group-containing polysiloxane having a specific structure as the component (A) and an alicyclic epoxy group-containing cage silsesquioxane having a specific structure as the component (B). The ratio of the contents of both components is set to (A) :( B) = 20: 80 to 80:20 on a mass basis. For this reason, when the thermosetting resin composition is cured by heat or light, a plurality of carboxyl groups of the component (A) having a specific structure and a plurality of alicyclic epoxy groups of the component (B) having a specific structure are obtained. A cured product is obtained by reaction. In this cured product, a siloxane bond having a high binding energy is the main component, and it is assumed that light resistance and heat yellowing resistance are improved. Furthermore, since the carboxyl group exhibits a rigid structure by cross-linking reaction with an alicyclic epoxy group, and the silsesquioxane skeleton also exhibits a rigid structure, the hardness of the cured product is increased and the tackiness on the surface is suppressed. It is done.

  Therefore, the thermosetting resin composition should be suitably used for sealing a light-emitting element having a high surface non-tack property of the cured product, being transparent, excellent in light resistance and heat yellowing resistance, and having a high output in a short wavelength region. it can.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
The thermosetting resin composition of this embodiment contains a carboxyl group-containing polysiloxane of the component (A) and an alicyclic epoxy group-containing cage silsesquioxane of the component (B) shown below. The content ratio is (A) :( B) = 20: 80 to 80:20 on a mass basis. The cured product obtained by curing this thermosetting resin composition has good surface non-tackiness, is transparent, excellent in light resistance and heat yellowing resistance, and suitable for sealing a light-emitting element having a high output in a short wavelength region. Can be used.
<Carboxyl group-containing polysiloxane of component (A)>
The carboxyl group-containing polysiloxane is a carboxyl group-containing polysiloxane having a plurality of (two or more) carboxyl groups and has a structure represented by the following formula (1).

〔式（１）中、ａは０〜５０の整数、ｂは３〜３００の整数であり、Ｒ^１は炭素数が１〜６のアルキル基、Ｘ^１は下記式（２）又は−（ＣＨ_２）_ｎ−ＣＯＯＨ（但し、ｎは１〜２０の整数）で表される置換基であり、Ｘ^２はＲ^１又は下記式（２）で表される置換基であり（但し、ａ＝０のときＸ^２≠Ｒ^１）、Ｒ^１とＸ^１はそれぞれ同一でも異なっていてもよい。〕
式（１）における、Ｒ^１は炭素数が１〜６のアルキル基、好ましくは１〜３のアルキル基であり、Ｒ^１は全て同一でも異なっていても良い。Ｒ^１がアルキル基ではなく芳香族炭化水素基や脂環族炭化水素基であると、耐光性が低下する。Ｒ^１の炭化水素数が６を上回る場合には、有機成分として炭化水素が増大するため耐熱黄変性が低下する。

Wherein (1), a is an integer of 0 to 50, b is an integer of 3 to 300, ^{R 1} is an alkyl group having 1 to 6 carbon atoms, ^{X 1} is the following formula (2) or - (CH _{2) n} -COOH (where, n is a substituent represented by an integer) of 1 to 20, ^{X 2} is a substituent represented by ^{R 1} or the following formula (2) (where, a = 0 X ² ≠ R ¹ ), R ¹ and X ¹ may be the same or different. ]
In the formula (1), R ¹ is an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having ¹ to 3 carbon atoms, and R ¹ may be all the same or different. When R ¹ is not an alkyl group but an aromatic hydrocarbon group or an alicyclic hydrocarbon group, light resistance decreases. When the number of hydrocarbons in R ¹ exceeds 6, hydrocarbons increase as an organic component, and heat yellowing decreases.

Specific examples of R ¹ include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups; isopropyl, isobutyl, sec-butyl, t-butyl, Examples thereof include branched alkyl groups such as isopentyl group, 3-methylbutyl group, sec-pentyl group, neopentyl group, t-pentyl group, isohexyl group, sec-hexyl group, and t-hexyl group. Of these, a methyl group is particularly preferred from the viewpoint of heat resistance.

X ¹ in the formula (1) is a substituent represented by the following formula (2) or — (CH ₂ ) _n —COOH (where n is an integer of 1 to 20). However, it is preferable that at least two of the X ¹ are substituents represented by the following formula (2).

式（２）中、Ｒ^２は炭素数が１〜１０のアルキレン基又はアルキレンオキシアルキレン基、ｋは０又は１である。Ｒ^２の炭素数が１０を上回る場合には、有機成分が増大するため硬化物の耐熱黄変性が低下する。Ｒ^２として具体的には例えば、メチレン基、エチレン基、プロピレン基、ブチレン基などのアルキレン基（−Ｒ−）；メチレンオキシメチレン基、メチレンオキシエチレン基、メチレンテトラオキシメチレン基等のアルキレンオキシアルキレン基（−ＲＯＲ−）が挙げられる。これらのＲ^２のうち、炭素数２〜５のアルキレン基が好ましい。

In formula (2), R ² is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, and k is 0 or 1. If the number of carbon atoms of R ² exceeds 10, the thermal yellowing resistance of the cured product for the organic component is increased is reduced. Specific examples of R ² include alkylene groups (—R—) such as methylene group, ethylene group, propylene group, and butylene group; alkyleneoxyalkylene groups such as methyleneoxymethylene group, methyleneoxyethylene group, and methylenetetraoxymethylene group. A group (-ROR-). Among these R ² , an alkylene group having 2 to 5 carbon atoms is preferable.

Formula (2) is a structure in which a carboxylic acid is substituted on the cyclohexane ring. By having a cyclohexane ring structure, rigidity can be imparted to highly flexible polysiloxane, and surface non-tackiness is improved. Wherein ^{X 1} is _- in the case of _(CH 2) n -COOH, that n is preferably an integer of 5 to 15, as an example _{- (CH 2) 8 -COOH,} - (CH 2) 10 _{-COOH, - (CH 2) 12} -COOH , and the like.

The number of repeating units of the carboxyl group-containing segment in the carboxyl group-containing polysiloxane, that is, a in the formula (1) is 0 to 50, preferably 0 to 10. When a is 0, it means that X ² ≠ R ¹ and has carboxyl groups only at both ends. When a is 1 to 50, it has a carboxyl group in the side chain, and a denser cross-linked structure can be taken, which is preferable from the viewpoint of surface non-tackiness and hardness of the cured product.

  When a exceeds 50, although the surface non-tack property of hardened | cured material is favorable, heat-resistant yellowing falls. This is because the acid equivalent in the carboxyl group-containing polysiloxane is reduced and the organic component is increased. This is because the bond (carbon-carbon bond or carbon-oxygen bond) in the organic component has a lower bond energy than the siloxane bond and is easily decomposed. In addition, an acid equivalent means mass required in order to obtain the carboxyl group production amount per mol of the carboxyl group-containing polysiloxane of the formula (1).

  The number of repeating units of the carboxyl group-free segment in the carboxyl group-containing polysiloxane, that is, b in the formula (1) is 3 to 300, preferably 9 to 150. When b is less than 3, the siloxane content in the carboxyl group-containing polysiloxane is reduced and the organic component is increased, so that the heat-resistant yellowing is reduced. When b exceeds 300, the molecular weight of the carboxyl group-containing polysiloxane is increased and the viscosity of the thermosetting resin composition is increased, which may cause problems in compatibility with the component (B) and workability. .

  Further, in the formulation of the thermosetting resin composition, the ratio (a) / ([carboxyl group-containing segment (a)] / [carboxyl group-free segment (b)] in the carboxyl group-containing polysiloxane of component (A). b) is usually from 0.01 to 5, preferably from 0.03 to 3. When the ratio (a) / (b) is within this range, the acid equivalent of the carboxyl group-containing polysiloxane becomes a sufficient value, and good curability is obtained. When (a) / (b) is smaller than 0.01, the acid equivalent is large and the curability of the thermosetting resin composition may be insufficient. On the other hand, when (a) / (b) is larger than 5, the acid equivalent is small, and the transparency of the cured product may be insufficient.

The carboxyl group-containing polysiloxane is obtained by reacting a carbinol group-containing precursor in which the substituent X ¹ corresponding to the formula (2) is —R ² —OH with the cyclohexane polycarboxylic acid anhydride in the same mole in the formula (1). It is obtained quantitatively by the ring-opening half esterification reaction. Specific examples of the cyclohexane polycarboxylic acid anhydride used when synthesizing the carboxyl group-containing polysiloxane include cyclohexane dicarboxylic acid anhydride and cyclohexane tricarboxylic acid anhydride. One of these cyclohexane polycarboxylic acid anhydrides may be used alone, or two or more thereof may be used in combination.

  The carbinol group-containing polysiloxane is preferably a functional compound at both terminals and having a number average molecular weight Mn of 1000 to 20000. When the number average molecular weight is lower than 1000, the siloxane content is decreased, and the organic component is increased correspondingly. On the other hand, when the number average molecular weight is higher than 20000, the viscosity of the thermosetting resin composition increases, which may impair the coatability.

In the method for producing a carboxyl group-containing polysiloxane, blending is performed so that 1 mol of the acid anhydride group of cyclohexane polycarboxylic acid anhydride reacts with respect to 1 mol of hydroxyl group of the carbinol group-containing polysiloxane. The reaction conditions are usually set in the temperature range of room temperature to 200 ° C. and 1 to 100 hours.
<Component (B) alicyclic epoxy group-containing cage silsesquioxane>
The alicyclic epoxy group-containing cage silsesquioxane is a siloxane having a polyhedral structure and has a structure represented by the following formula (3).

〔式（３）中、Ｒ^６は炭素数が１〜１０のアルキレン基又はアルキレンオキシアルキレン基、Ｒ^７は炭素数が１〜１０のアルキレン基又はアルキレンオキシアルキレン基、Ｒ^８は炭素数が１〜４のアルキル基、Ｒ^９は炭素数が１〜４のアルキル基、ｍは１〜３の整数、Ｒ^５は置換又非置換のアルキル基、ｒは６、８、１０及び１２から選ばれた数、ｐは２〜ｒの整数及びｑは０〜（ｒ−ｐ）の整数を表す。〕
すなわち、脂環式エポキシ基含有かご型シルセスキオキサンは、下記の式（４）で示されるシルセスキオキサン骨格に、下記の式（５）で示される脂環式エポキシ基を有する置換基、下記の式（６）で示されるアルコキシシリル基を有する置換基、及び下記の式（７）で示されるアルキル基を有する置換基をそれぞれｐ、ｑ、及びｒ−ｐ−ｑ個有するかご型シルセスキオキサンである。

[In Formula (3), R ⁶ is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, R ⁷ is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, and R ⁸ is 1 carbon atom. ˜4 alkyl group, R ⁹ is an alkyl group having 1 to 4 carbon atoms, m is an integer of 1 to 3, R ⁵ is a substituted or unsubstituted alkyl group, r is selected from 6, 8, 10 and 12. P, an integer of 2 to r, and q represents an integer of 0 to (rp). ]
That is, the alicyclic epoxy group-containing cage silsesquioxane is a substituent having an alicyclic epoxy group represented by the following formula (5) on the silsesquioxane skeleton represented by the following formula (4). A cage type having p, q, and rpq substituents each having an alkoxysilyl group represented by the following formula (6) and an alkyl group represented by the following formula (7): Silsesquioxane.

式（５）におけるＲ^６としては、炭素数が１〜３のアルキレン基であることが好ましい。アルキレン基として具体的にはエチレン基〔−（ＣＨ_２）_２−〕が好ましい。

R ⁶ in Formula (5) is preferably an alkylene group having 1 to 3 carbon atoms. Specifically, an ethylene group [— (CH ₂ ) ₂ —] is preferable as the alkylene group.

式（６）におけるＲ^７としては、炭素数が１〜３のアルキレン基であることが好ましい。係るアルキレン基としては、エチレン基が好ましい。Ｒ^８及びＲ^９は炭素数が１〜３のアルキル基であることが好ましく、具体的にはメチル基（−ＣＨ_３）が好ましい。

R ⁷ in Formula (6) is preferably an alkylene group having 1 to 3 carbon atoms. Such an alkylene group is preferably an ethylene group. R ⁸ and R ⁹ are preferably an alkyl group having 1 to 3 carbon atoms, and specifically, a methyl group (—CH ₃ ) is preferred.

式（７）におけるＲ^５の置換又は非置換のアルキル基とは、炭素数１〜２０のアルキル基、炭素数５〜１２のシクロアルキル基、フェニル基等の炭素数６〜１２のアリール基、エーテル結合を含有する炭素数１〜２０の炭化水素基、エステル結合を含有する炭素数１〜２０の炭化水素基及びトリオルガノシロキシ基を含有する炭素数１〜１２の炭化水素基からなる群から選択された少なくとも１種である。

The substituted or unsubstituted alkyl group represented by R ⁵ in Formula (7) is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms such as a phenyl group, From the group consisting of a hydrocarbon group having 1 to 20 carbon atoms containing an ether bond, a hydrocarbon group having 1 to 20 carbon atoms containing an ester bond, and a hydrocarbon group having 1 to 12 carbon atoms containing a triorganosiloxy group At least one selected.

  Specifically, examples of the alkyl group having 1 to 20 carbon atoms 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, and a decyl group. . Examples of the cycloalkyl group having 5 to 12 carbon atoms include a cyclopentyl group, a cyclohexyl group, and a norbornyl group. Examples of the alkyl group having 1 to 12 carbon atoms containing a triorganosiloxy group are usually straight chain having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms such as methylene group, ethylene group, propylene group and butylene group. Examples thereof include a triorganosiloxy-substituted alkyl group in which a triorganosiloxy group is bonded to a chain, cyclic or branched alkylene group. Among these, it is preferable that it is a C1-C10 alkyl group.

  R in the formula (3) is a number selected from 6, 8, 10 and 12, and is preferably 8. p is an integer of 2 to r, preferably an integer of 4 to r. When r is smaller than 2, a crosslinked structure is not formed in the cured product, and the cured product does not have the desired physical properties. q is an integer of 0 to (rp), and when it is an integer of 1 or more, in addition to the reaction of a carboxyl group and an epoxy group, a crosslinked structure is formed even by a bond between hydrolysis and polycondensation of alkoxy groups. This is preferable from the viewpoint of surface non-tackiness.

As a method for synthesizing the above cage silsesquioxane, a method of introducing a substituent into a synthesized cage structure of a cage silsesquioxane, or a hydrolysis of a trifunctional organosilicon monomer having a substituent. Although methods are known, any of them may be used. The skeleton structure of cage silsesquioxanes can be synthesized by various methods, for example, see Chem. Rev. 1995, 95, 1431 and J.H. Am. Che. Soc. 1989, 111, 1741 or Organometallics. 1991, 10, 2526 and the like. Further, for example, an alkyl group can be introduced onto the silicon at the apex by using a hydrosilylation reaction to octakis (hydridosilsesquioxane) in which each apex of the hexahedron is made of silicon and each side is made of oxygen (for example, (See Japanese Patent No. 3020164).
<Ratio of content of component (A) and component (B)>
In the thermosetting resin composition, the ratio of the content of component (A) to component (B) is component (A): component (B) = 20: 80 to 80:20 on a mass basis, preferably 30: 70-75: 25. If component (A): component (B) = 20: 80 is removed and the content of the carboxyl group-containing polysiloxane of component (A) is too small, the curability of the thermosetting resin composition will be insufficient and curing will occur. The heat resistance of the object decreases. On the other hand, when component (A): component (B) = 80: 20 is removed and the content ratio of the carboxyl group-containing polysiloxane of component (A) becomes too large, the alicyclic epoxy group-containing cage of component (B) Since the ratio of the silsesquioxane type is reduced, the rigid properties of the cage silsesquioxane skeleton are hardly expressed, and the surface non-tackiness of the cured product cannot be obtained.

  Further, the compounding amount of the carboxyl group-containing polysiloxane of component (A) and the alicyclic epoxy group-containing cage silsesquioxane of component (B) is (equivalent of carboxyl group derived from carboxyl group-containing polysiloxane) / The ratio (equivalent ratio) of (equivalent ratio of epoxy group derived from alicyclic epoxy group-containing cage silsesquioxane) is usually 0.2 to 2.0, preferably 0.7 to 1.2, more preferably It is adjusted to be 0.8 to 1.1. If the ratio is less than 0.2, the adhesiveness of the cured product obtained by curing the thermosetting resin composition may be reduced. On the other hand, if the ratio is more than 2.0, the curing is poor due to excess carboxylic acid. Occurs, or the transparency of the cured product decreases.

  By using the carboxyl group-containing polysiloxane of component (A) and the alicyclic epoxy group-containing cage silsesquioxane of component (B) in the above proportions, surface non-tackiness, light resistance and heat-resistant yellowing can be simultaneously achieved. A thermosetting resin composition capable of exhibiting excellent performance to be satisfied is obtained. About the mechanism which can express these outstanding performances, it estimates as follows.

  That is, in general, polysiloxane and silsesquioxane are composed of siloxane bonds (silicon-oxygen bonds), and these siloxane bonds have higher atomic bond energy than carbon-carbon bonds. It is considered that yellowing can be enhanced. The thermosetting resin composition contains a carboxyl group-containing polysiloxane and an alicyclic epoxy group-containing cage-type silsesquioxane, and the siloxane content is high. Denaturation can be improved.

The tackiness is largely due to the hardness of the cured product. Since the carboxyl group at the terminal of the carboxyl group-containing polysiloxane and the alicyclic epoxy group of the alicyclic epoxy group-containing cage-type silsesquioxane are bonded to cyclohexane, the structure is rigid. In addition, the cage silsesquioxane skeleton also has a rigid structure, and it is thought that the synergistic effect of these increases the hardness and improves the surface non-tackiness.
<Curing of thermosetting resin composition>
By thermosetting or photocuring the thermosetting resin composition, a cured product used as an optical semiconductor sealing agent or the like is obtained. In this case, the thermosetting resin composition adds an acid catalyst for the purpose of accelerating the curing reaction when cured at a low temperature in a short time and imparting good chemical performance and physical performance to the cured product. May be. Examples of the acid catalyst include proton acids such as phosphoric acid, sulfonic acid, and boric acid; boron fluoride (BF ₃ ), ferric chloride (FeC1 ₃ ), stannic chloride (SnC1 ₄ ), aluminum chloride (A1C1 ₃ ), Zinc chloride (ZnCl ₂ ), and Lewis acids such as organometallic complexes. Of these, organometallic complexes are particularly preferred from the viewpoints of curability and transparency. As the acid catalyst, any one or two or more of the above compounds can be used in appropriate combination.

  The addition amount of this acid catalyst is normally set in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the total solid content of the thermosetting resin composition. When the addition amount of the acid catalyst is less than 0.01 parts by mass, the catalytic effect is not sufficiently exhibited, and when it exceeds 10 parts by mass, the obtained cured product may be colored or the water resistance may be lowered. Is not preferable.

  The thermosetting resin composition can be used after diluted with an organic solvent. Examples of the organic solvent include aromatic hydrocarbons, alicyclic hydrocarbons, esters, halogen-containing aliphatic hydrocarbons, ketones, ethers, and the like. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more types as appropriate. The usage-amount of an organic solvent is 30 mass parts or less normally with respect to 100 mass parts of thermosetting resin compositions, Preferably it is 7 mass parts or less.

  In addition, for the thermosetting resin composition, a coupling agent, an antioxidant, an ultraviolet absorber, a visible light absorber, an infrared absorber, a modifier, a filler, a flame retardant, a thixotropic agent, etc., as necessary. These other additives can be blended according to conventional methods. Other additives may be used alone or in combination of two or more. Moreover, the addition amount is 0.01-10 mass parts normally with respect to 100 mass parts of total solid content of a thermosetting resin composition.

When using a thermosetting resin composition as a sealing agent, it can implement by thermosetting or photocuring this thermosetting resin composition. In that case, the thermosetting resin composition is applied and cured by an overcoat method, a dip coat method, or the like, or the composition is placed in a container and the optical semiconductor element is dipped therein and cured as it is. For example, the optical semiconductor element can be sealed.
<Summary of effects exhibited by the embodiment>
In the thermosetting resin composition of the present embodiment, the carboxyl group-containing polysiloxane having a specific structure having a cyclohexane ring as the component (A) and the alicyclic epoxy group-containing basket having a specific structure having a cyclohexane ring as the component (B) Contains type silsesquioxane. And the ratio of content of both components is set to the range of (A) :( B) = 20: 80 to 80:20 on a mass basis. For this reason, when the thermosetting resin composition is thermoset or photocured, a plurality of carboxyl groups of the component (A) react with a plurality of alicyclic epoxy groups of the component (B) to obtain a cured product. . This cured product is mainly composed of siloxane bonds having high binding energy, and is considered to improve light resistance and heat yellowing resistance. In addition, since the carboxyl group and alicyclic epoxy group are bonded to the cyclohexane ring and exhibit a rigid structure, and the silsesquioxane skeleton also exhibits a rigid structure, the hardness of the cured product is increased and the tack on the surface is increased. Sex is suppressed.

  Therefore, the thermosetting resin composition has good surface non-tackiness of the cured product, is transparent, and is excellent in light resistance and heat yellowing resistance. Therefore, it can be suitably used for demanding applications such as sealing of light emitting elements with high output in the short wavelength region, particularly LED elements.

Hereinafter, the embodiment will be described more specifically with reference to synthesis examples, examples, and comparative examples.
[Synthesis Example 1, Synthesis of carboxyl group-containing polysiloxane (A-1)]
In a 300 mL four-round flask equipped with a thermometer, a reflux condenser and a stirrer, 164.1 g of a carbinol group-containing polysiloxane (molecular weight 1810) represented by the following formula (8) and 35.9 g of cyclohexanetricarboxylic anhydride And an addition reaction was carried out at a reaction temperature of 140 ° C. After reacting at the same temperature for 6 hours, the reaction was terminated, and the mixture was allowed to cool and then collected. As a result, a colorless and transparent carboxyl group-containing polysiloxane (A-1, acid equivalent = 533 g / mol) represented by the following formula (9) was obtained in a yield of 91%.

〔合成例２、カルボキシル基含有ポリシロキサン（Ａ−２）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、下記式（１０）で表されるカルビノール基含有ポリシロキサン（分子量１１２２０）１８０．８ｇ及びシクロヘキサントリカルボン酸無水物１９．２ｇを投入し、反応温度１４０℃で付加反応を行った。同温度で６時間反応させた後、反応終了とし、放冷させた後に回収した。その結果、下記式（１１）で表される無色透明のカルボキシル基含有ポリシロキサン（Ａ−２、酸当量＝１０３４ｇ／ｍｏｌ）を９２％の収率で得た。

[Synthesis Example 2, synthesis of carboxyl group-containing polysiloxane (A-2)]
In a 300 mL four-round flask equipped with a thermometer, a reflux condenser and a stirrer, 180.8 g of a carbinol group-containing polysiloxane (molecular weight 11220) represented by the following formula (10) and 19.2 g of cyclohexanetricarboxylic acid anhydride And an addition reaction was carried out at a reaction temperature of 140 ° C. After reacting at the same temperature for 6 hours, the reaction was terminated, and the mixture was allowed to cool and then collected. As a result, a colorless and transparent carboxyl group-containing polysiloxane (A-2, acid equivalent = 1034 g / mol) represented by the following formula (11) was obtained in a yield of 92%.

〔合成例３、カルボキシル基含有ポリシロキサン（Ａ−３）の合成〕
温度計、還流冷却器及び撹拌機を備えた１Ｌの４つロフラスコに、下記式（１２）で表されるカルビノール基含有ポリシロキサン（分子量９１８）１４９．８ｇ及びシクロヘキサンジカルボン酸無水物５０．２ｇを投入し、反応温度１４０℃で付加反応を行った。同温度で６時間反応させた後、反応終了とし、放冷させた後に回収した。その結果、下記式（１３）で表される無色透明のカルボキシル基含有ポリシロキサン（Ａ−３、酸当量＝６１３ｇ／ｍｏｌ）を９３％の収率で得た。

[Synthesis Example 3, Synthesis of carboxyl group-containing polysiloxane (A-3)]
In a 1 L 4-round flask equipped with a thermometer, a reflux condenser, and a stirrer, 149.8 g of a carbinol group-containing polysiloxane (molecular weight 918) represented by the following formula (12) and 50.2 g of cyclohexanedicarboxylic anhydride And an addition reaction was carried out at a reaction temperature of 140 ° C. After reacting at the same temperature for 6 hours, the reaction was terminated, and the mixture was allowed to cool and then collected. As a result, a colorless and transparent carboxyl group-containing polysiloxane (A-3, acid equivalent = 613 g / mol) represented by the following formula (13) was obtained in a yield of 93%.

〔合成例４、カルボキシル基含有ポリシロキサン（Ａ−４）の合成〕
温度計、還流冷却器、撹拌機を備えた１リットルの４つ口フラスコに、式（１４）で表されるハイドロジェンメチルポリシロキサン８４ｇ、トルエン５００ｇ、下記式（１５）で表されるトリメチルシリル末端基のオルガノアシロキシシラン２５６ｇを加え、１１０℃で６時間反応させた後、赤外分光光度計によりＳｉ−Ｈ結合の消滅を確認した。その後、水を加え１１０℃で５時間加熱した後、赤外分光光度計によりカルボキシル基の生成を確認し、下記式（１６）で表される無色透明のカルボキシル基含有ポリシロキサン（Ａ−４）を６９％の収率で得た。

[Synthesis Example 4, synthesis of carboxyl group-containing polysiloxane (A-4)]
In a 1 liter four-necked flask equipped with a thermometer, a reflux condenser, and a stirrer, 84 g of hydrogen methylpolysiloxane represented by the formula (14), 500 g of toluene, and a trimethylsilyl terminal represented by the following formula (15) After adding 256 g of the group organoacyloxysilane and reacting at 110 ° C. for 6 hours, the disappearance of the Si—H bond was confirmed by an infrared spectrophotometer. Then, after adding water and heating at 110 degreeC for 5 hours, the production | generation of a carboxyl group was confirmed with the infrared spectrophotometer, and the colorless and transparent carboxyl group containing polysiloxane (A-4) represented by following formula (16) Was obtained in 69% yield.

〔合成例５、カルボキシル基含有ポリシロキサン（Ａ−５）の合成〕
温度計、還流冷却器、撹拌機を備えた１リットルの４つ口フラスコに、下記式（１７）で表されるハイドロジェンメチルポリシロキサン８７ｇ、トルエン５００ｇ、前記式（１５）で表されるトリメチルシリル末端基のオルガノアシロキシシラン２５６ｇを加え、１１０℃で４時間反応させた後、赤外分光光度計によりＳｉ−Ｈ結合の消滅を確認した。その後、水を加え１１０℃で５時間加熱した後、赤外分光光度計によりカルボキシル基の生成を確認し、下記式（１８）で表される無色透明のカルボキシル基含有オルガノポリシロキサン（Ａ−５）を７７％の収率で得た。

[Synthesis Example 5, Synthesis of carboxyl group-containing polysiloxane (A-5)]
In a 1 liter four-necked flask equipped with a thermometer, a reflux condenser, and a stirrer, 87 g of hydrogenmethylpolysiloxane represented by the following formula (17), 500 g of toluene, and trimethylsilyl represented by the above formula (15) After adding 256 g of end-group organoacyloxysilane and reacting at 110 ° C. for 4 hours, the disappearance of the Si—H bond was confirmed by an infrared spectrophotometer. Then, after adding water and heating at 110 degreeC for 5 hours, the production | generation of a carboxyl group was confirmed with the infrared spectrophotometer, and the colorless and transparent carboxyl group containing organopolysiloxane (A-5) represented by following formula (18) is shown. ) Was obtained in 77% yield.

〔合成例６、脂環式エポキシ基含有かご型シルセスキオキサン（ＳＱ−１）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、窒素雰囲気下、オクタキス［ヒドリドジメチルシロキシ］シルセスキオキサン（ＯＨＳＳ）を１０．１８ｇ（１０ｍｍｏｌ）、４−ビニルシクロヘキセン−１，２−エポキシドを４．９７ｇ（４０ｍｍｏｌ）、１−オクテンを４．４９ｇ（４０ｍｍｏｌ）及び脱水トルエンを３０ｇ投入した。ＯＨＳＳを溶解させた後、触媒として１，３−ジビニル−１，１，３，３−テトラメチルジシロキサン白金０．１Ｍキシレン溶液を０．０３ｍＬ加えて、７０℃で３時間反応させた。その後、活性炭によって触媒を取り除き、溶媒を留去することにより、無色透明粘性液体１８．７ｇ（９．５ｍｍｏｌ）を得た。

[Synthesis Example 6, synthesis of caged silsesquioxane (SQ-1) containing alicyclic epoxy group]
10.18 g (10 mmol) of octakis [hydridodimethylsiloxy] silsesquioxane (OHSS), 4-vinylcyclohexene-1 in a 300 mL four-neck flask equipped with a thermometer, reflux condenser and stirrer under a nitrogen atmosphere , 2-epoxide 4.97 g (40 mmol), 1-octene 4.49 g (40 mmol) and dehydrated toluene 30 g. After OHSS was dissolved, 0.03 mL of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum 0.1M xylene solution was added as a catalyst and reacted at 70 ° C. for 3 hours. Thereafter, the catalyst was removed with activated carbon, and the solvent was distilled off to obtain 18.7 g (9.5 mmol) of a colorless transparent viscous liquid.

  As a result of measuring the obtained reaction product by 1H-NMR spectrum, it was confirmed that it was a cage-type silsesquioxane (SQ-1) represented by the following formula (19). The yield of SQ-1 obtained was 95%, and the epoxy equivalent was 491 g / mol.

〔合成例７、脂環式エポキシ基含有かご型シルセスキオキサン（ＳＱ−２）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、窒素雰囲気下、ＯＨＳＳを１０．１８ｇ（１０ｍｍｏｌ）、４−ビニルシクロヘキセン−１，２−エポキシドを４．９７ｇ（４０ｍｍｏｌ）、ジメトキシメチルビニルシランを５．２９ｇ（４０ｍｍｏｌ）及び脱水トルエンを３０ｇ投入した。ＯＨＳＳを溶解させた後、触媒として１，３−ジビニル−１，１，３，３−テトラメチルジシロキサン白金０．１Ｍキシレン溶液を０．０３ｍＬ加えて、７０℃で３時間反応させた。その後、活性炭により触媒を取り除き、溶媒を留去することにより、無色透明粘性液体１９．２ｇ（９．４ｍｍｏｌ）を得た。

[Synthesis Example 7, Synthesis of cage-type silsesquioxane (SQ-2) containing alicyclic epoxy group]
To a 300 mL four-neck flask equipped with a thermometer, a reflux condenser and a stirrer, under a nitrogen atmosphere, 10.18 g (10 mmol) of OHSS, 4.97 g (40 mmol) of 4-vinylcyclohexene-1,2-epoxide, 5.29 g (40 mmol) of dimethoxymethylvinylsilane and 30 g of dehydrated toluene were added. After OHSS was dissolved, 0.03 mL of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum 0.1M xylene solution was added as a catalyst and reacted at 70 ° C. for 3 hours. Thereafter, the catalyst was removed with activated carbon, and the solvent was distilled off to obtain 19.2 g (9.4 mmol) of a colorless transparent viscous liquid.

  As a result of measuring the obtained reaction product by 1H-NMR spectrum, it was confirmed that it was a cage-type silsesquioxane (SQ-2) represented by the following formula (20). The yield of SQ-2 obtained was 94%, and the epoxy equivalent was 511 g / mol.

〔合成例８、脂環式エポキシ基含有かご型シルセスキオキサン（ＳＱ−３）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、窒素雰囲気下、ＯＨＳＳを１０．１８ｇ（１０ｍｍｏｌ）、４−ビニルシクロヘキセン−１，２−エポキシドを４．９７ｇ（４０ｍｍｏｌ）、トリメトキシビニルシランを１．４８ｇ（１０ｍｍｏｌ）、１−オクテンを３．３７ｇ（３０ｍｍｏｌ）及び脱水トルエンを３０ｇ投入した。ＯＨＳＳを溶解させた後、触媒として１，３−ジビニル−１，１，３，３−テトラメチルジシロキサン白金０．１Ｍキシレン溶液を０．０３ｍＬ加えて、７０℃で３時間反応させた。その後、活性炭によって触媒を取り除き、溶媒を留去することにより、無色透明粘性液体１９．０ｇ（９．５ｍｍｏｌ）を得た。

[Synthesis Example 8, Synthesis of alicyclic epoxy group-containing cage silsesquioxane (SQ-3)]
To a 300 mL four-neck flask equipped with a thermometer, a reflux condenser and a stirrer, under a nitrogen atmosphere, 10.18 g (10 mmol) of OHSS, 4.97 g (40 mmol) of 4-vinylcyclohexene-1,2-epoxide, 1.48 g (10 mmol) of trimethoxyvinylsilane, 3.37 g (30 mmol) of 1-octene and 30 g of dehydrated toluene were added. After OHSS was dissolved, 0.03 mL of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum 0.1M xylene solution was added as a catalyst and reacted at 70 ° C. for 3 hours. Thereafter, the catalyst was removed with activated carbon, and the solvent was distilled off to obtain 19.0 g (9.5 mmol) of a colorless transparent viscous liquid.

  As a result of measuring the obtained reaction product by 1H-NMR spectrum, it was confirmed that it was a cage-type silsesquioxane (SQ-3) represented by the following formula (21). The yield of SQ-3 obtained was 95%, and the epoxy equivalent was 500 g / mol.

〔合成例９、脂環式エポキシ基含有かご型シルセスキオキサン（ＳＱ−４）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、窒素雰囲気下、オクタキス［ヒドリドジメチルシロキシ］シルセスキオキサン（ＯＨＳＳ）を１０．１８ｇ（１０ｍｍｏｌ）、４−ビニルシクロヘキセン−１，２−エポキシドを６．２１ｇ（５０ｍｍｏｌ）、１−オクテンを３．３７（３０ｍｍｏｌ）及び脱水トルエンを３０ｇ投入した。ＯＨＳＳを溶解させた後、触媒として１，３−ジビニル−１，１，３，３−テトラメチルジシロキサン白金０．１Ｍキシレン溶液を０．０３ｍＬ加えて、７０℃で３時間反応させた。その後、活性炭によって触媒を取り除き、溶媒を留去することにより、無色透明粘性液体１８．８ｇ（９．５ｍｍｏｌ）を得た。

[Synthesis Example 9, Synthesis of cage-type silsesquioxane (SQ-4) containing alicyclic epoxy group]
10.18 g (10 mmol) of octakis [hydridodimethylsiloxy] silsesquioxane (OHSS), 4-vinylcyclohexene-1 in a 300 mL four-neck flask equipped with a thermometer, a reflux condenser and a stirrer under a nitrogen atmosphere Then, 6.21 g (50 mmol) of 2-epoxide, 3.37 (30 mmol) of 1-octene and 30 g of dehydrated toluene were added. After OHSS was dissolved, 0.03 mL of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum 0.1M xylene solution was added as a catalyst and reacted at 70 ° C. for 3 hours. Thereafter, the catalyst was removed with activated carbon, and the solvent was distilled off to obtain 18.8 g (9.5 mmol) of a colorless transparent viscous liquid.

  As a result of measuring the obtained reaction product by a 1H-NMR spectrum, it was confirmed that it was a cage silsesquioxane (SQ-4) represented by the following formula (22). The yield of SQ-4 obtained was 95%, and the epoxy equivalent was 395 g / mol.

〔比較合成例１、カルボキシル基含有ポリシロキサン（Ａ−６）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、下記式（２３）で表されるカルビノール基含有ポリシロキサン（分子量２４１５８）を１９５．２ｇ及びシクロヘキサントリカルボン酸無水物４．８ｇを投入し、反応温度１４０℃で付加反応を行った。同温度で６時間反応させた後、反応終了とし、放冷させた後に回収した。その結果、下記式（２４）で表される無色透明のカルボキシル基含有ポリシロキサン（Ａ−６、酸当量＝４１２５ｇ／ｍｏｌ）を９１％の収率で得た。

[Comparative Synthesis Example 1, synthesis of carboxyl group-containing polysiloxane (A-6)]
195.2 g of a carbinol group-containing polysiloxane (molecular weight 24158) represented by the following formula (23) and cyclohexanetricarboxylic acid anhydride are added to a 300 mL four-round flask equipped with a thermometer, a reflux condenser and a stirrer. 8 g was added and an addition reaction was performed at a reaction temperature of 140 ° C. After reacting at the same temperature for 6 hours, the reaction was terminated, and the mixture was allowed to cool and then collected. As a result, a colorless and transparent carboxyl group-containing polysiloxane (A-6, acid equivalent = 4125 g / mol) represented by the following formula (24) was obtained in a yield of 91%.

〔比較合成例２、エポキシ基含有かご型シルセスキオキサン（ＳＱ−５）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、窒素雰囲気下、オクタキス［ヒドリドジメチルシロキシ］シルセスキオキサン（ＯＨＳＳ）を１０．１８ｇ（１０ｍｍｏｌ）、アリルグリシジルエーテルを４．５７ｇ（４０ｍｍｏｌ）、１−オクテンを４．４９ｇ（４０ｍｍｏｌ）及び脱水トルエンを３０ｇ投入した。ＯＨＳＳを溶解させた後、触媒として１，３−ジビニル−１，１，３，３−テトラメチルジシロキサン白金０．１Ｍキシレン溶液を０．０３ｍＬ加えて、７０℃で３時間反応させた。その後、活性炭で触媒を取り除き、溶媒を留去することにより、無色透明粘性液体１８．１ｇ（９．５ｍｍｏｌ）を得た。

[Comparative Synthesis Example 2, Synthesis of Epoxy Group-Containing Cage Silsesquioxane (SQ-5)]
In a 300 mL four-round flask equipped with a thermometer, a reflux condenser, and a stirrer, 10.18 g (10 mmol) of octakis [hydridodimethylsiloxy] silsesquioxane (OHSS) and allyl glycidyl ether were added under a nitrogen atmosphere. 57 g (40 mmol), 4.49 g (40 mmol) of 1-octene and 30 g of dehydrated toluene were added. After OHSS was dissolved, 0.03 mL of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum 0.1M xylene solution was added as a catalyst and reacted at 70 ° C. for 3 hours. Thereafter, the catalyst was removed with activated carbon, and the solvent was distilled off to obtain 18.1 g (9.5 mmol) of a colorless transparent viscous liquid.

  As a result of measuring the obtained reaction product by a 1H-NMR spectrum, it was confirmed that it was a cage silsesquioxane (SQ-5) represented by the following formula (25). The yield of SQ-5 was 94%, and the epoxy equivalent was 481 g / mol.

〔比較合成例３、エポキシ基含有かご型シルセスキオキサン（ＳＱ−６）の合成〕
温度計、還流冷却器及び撹拌機を備えた３００ｍＬの４つロフラスコに、窒素雰囲気下、オクタキス［ヒドリドジメチルシロキシ］シルセスキオキサン（ＯＨＳＳ）を１０．１８ｇ（１０ｍｍｏｌ）、アリルグリシジルエーテルを９．１３（８０ｍｍｏｌ）及び脱水トルエンを３０ｇ投入した。ＯＨＳＳを溶解させた後、触媒として１，３−ジビニル−１，１，３，３−テトラメチルジシロキサン白金０．１Ｍキシレン溶液を０．０３ｍＬ加えて、７０℃で３時間反応させた。その後、活性炭で触媒を取り除き、溶媒を留去することにより、無色透明粘性液体１８．２ｇ（９．４ｍｍｏｌ）を得た。

[Comparative Synthesis Example 3, Synthesis of epoxy group-containing cage silsesquioxane (SQ-6)]
In a 300 mL four-necked flask equipped with a thermometer, a reflux condenser and a stirrer, 10.18 g (10 mmol) of octakis [hydridodimethylsiloxy] silsesquioxane (OHSS) and allylic glycidyl ether were added under a nitrogen atmosphere. 13 (80 mmol) and 30 g of dehydrated toluene were added. After OHSS was dissolved, 0.03 mL of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum 0.1M xylene solution was added as a catalyst and reacted at 70 ° C. for 3 hours. Thereafter, the catalyst was removed with activated carbon, and the solvent was distilled off to obtain 18.2 g (9.4 mmol) of a colorless transparent viscous liquid.

  As a result of measuring the obtained reaction product by 1H-NMR spectrum, it was confirmed that it was a cage-type silsesquioxane (SQ-6) represented by the following formula (26). The yield of SQ-6 was 94% and the epoxy equivalent was 241 g / mol.

〔試験方法〕
実施例及び比較例における硬化物外観、表面非タック性、耐光性及び耐熱黄変性の試験方法を下記に示す。
（１）硬化物外観
熱硬化性樹脂組成物を硬化させて、厚さ３ｍｍの硬化物を作製した。作製した硬化物の外観を目視にて観察し、下記の基準で評価した。

〔Test method〕
Test methods for cured product appearance, surface non-tackiness, light resistance, and heat yellowing resistance in Examples and Comparative Examples are shown below.
(1) Appearance of cured product The thermosetting resin composition was cured to produce a cured product having a thickness of 3 mm. The appearance of the produced cured product was visually observed and evaluated according to the following criteria.

○: Transparent. X: It was whitening.
(2) Surface non-tackiness The thermosetting resin composition was cured to produce a cured product having a thickness of 3 mm. The prepared cured product was observed for the tackiness of the surface of the test piece by finger observation, and the surface non-tackiness was evaluated according to the following criteria.

○: Tack was not recognized. X: Tack was recognized.
(3) Light resistance The thermosetting resin composition was cured to produce a cured product having a thickness of 3 mm. The produced cured product was irradiated with ultraviolet rays (UV) for 2 hours with a spot UV irradiation apparatus [EXECRE 4000, manufactured by HOYA Co., Ltd.], and then the color change was visually observed. From the observation results, evaluation was performed according to the following criteria, and it was determined that the sample was suitable for practical use with a mark of ◯ or higher.

A: No change. ○: Light yellow Δ: Colored yellow. X: Colored brown.
(4) Heat-resistant yellowing The thermosetting resin composition was cured to produce a cured product having a thickness of 3 mm. The produced cured product was stored at 150 ° C. for 24 hours, and then the color difference of the cured product was measured with a color difference meter [manufactured by Minolta, Inc., CM-3500d]. From the measured b value of the color difference, evaluation was performed according to the following criteria, and it was determined that it was suitable for practical use with a value of ◯ or more.

A: Less than 1 ○: 1 or more and less than 2. Δ: 2 or more and less than 4. X: 4 or more.
[Examples 1-8 and Comparative Examples 1-7]
The thermosetting resin compositions of Examples 1 to 8 and Comparative Examples 1 to 7, the carboxyl group-containing polysiloxane of component (A), the alicyclic epoxy group-containing cage silsesquioxane of component (B) and addition It was prepared by blending so that the composition of the agent would be the composition shown in Table 1 and Table 2, and stirring uniformly. In this case, each component was blended so that the equivalent ratio of carboxyl group / epoxy group was approximately 1. Next, the thermosetting resin compositions of each Example and Comparative Example were molded into a shape according to the test method shown above, subjected to vacuum degassing for 1 minute, and then prebaked at 100 ° C. for 1 hour, then 150 ° C. Was cured for 1 hour to obtain a cured product.

  About the obtained hardened | cured material, hardened | cured material external appearance, surface non-tack property, light resistance, and heat yellowing were measured by the said method, and those results were shown in Table 1 and Table 2. In addition, the meaning of the symbol in Table 1 and Table 2 is as follows.

AO-50: Stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, antioxidant (“ADEKA STAB AO-50”, trade name, manufactured by ADEKA Corporation)
X-22-3710: One-terminal carboxylic acid-modified silicone oil [trade name, manufactured by Shin-Etsu Chemical Co., Ltd.], carboxyl equivalent 1,470 g / mol
MH-700: 4-methylhexahydrophthalic acid [“Rikacid MH-700” manufactured by Shin Nippon Rika Co., Ltd., trade name]
X-22-169AS: Alicyclic epoxy-modified silicone oil [trade name, manufactured by Shin-Etsu Chemical Co., Ltd.], epoxy equivalent 500 g / mol
Cel2021P: (3,4-epoxycyclohexyl) methyl 3 ′, 4′-epoxycyclohexanecarboxylate, alicyclic epoxy resin [“Celoxide 2021P”, trade name, manufactured by Daicel Chemical Industries, Ltd.], epoxy equivalent 126 g / mol.

表１に示したように、実施例１〜８の熱硬化性樹脂組成物では、透明性、耐光性、耐熱黄変性及び表面非タック性のいずれの特性についても優れることが明らかになった。従って、実施例１〜８の熱硬化性樹脂組成物を光半導体封止用として好適に使用することができ、電子部品材料や光半導体素子の封止材料として非常に有用である。

As shown in Table 1, it was clarified that the thermosetting resin compositions of Examples 1 to 8 were excellent in all of the characteristics of transparency, light resistance, heat yellowing and surface non-tackiness. Therefore, the thermosetting resin compositions of Examples 1 to 8 can be suitably used for optical semiconductor sealing, and are very useful as electronic component materials and optical semiconductor element sealing materials.

  On the other hand, as shown in Table 2, in Comparative Example 1, when a one-terminal carboxylic acid-modified silicone oil was used instead of the carboxyl group-containing polysiloxane (A) of the present invention, the appearance of the cured product, the surface It can be seen that tackiness and heat yellowing performance do not reach practical levels. Similarly, in Comparative Example 2, when a single-terminal carboxylic acid-modified silicone oil having only one carboxyl group is used as a curing agent, the compatibility between the components is not sufficient, and the appearance of the cured product deteriorates and is practically used. It will no longer be available. When the ratio of the carboxyl group-containing polysiloxane (A) and the alicyclic epoxy group-containing cage silsesquioxane (B) is not within the range of the ratio of the thermosetting resin composition of the present invention, Comparative Example 3 As shown, surface non-tackiness cannot be obtained. Furthermore, in Comparative Examples 4 to 6, an epoxy compound having a structure different from that of the alicyclic epoxy group-containing cage silsesquioxane (B) used in the present invention is used. Therefore, it was confirmed that at least one of transparency, light resistance, heat yellowing resistance, and surface non-tackiness has a problem.

  As described above, the present invention provides a thermosetting resin composition having excellent transparency, light resistance, heat yellowing resistance, and surface non-tackiness. Therefore, the thermosetting resin composition of the present invention is useful for optical electronic member applications such as an optical semiconductor encapsulant.

Claims (1)

It contains the following component (A) and component (B), and the ratio of the content of both components is component (A): component (B) = 20: 80 to 80:20 on a mass basis. Thermosetting resin composition.
Component (A): A carboxyl group-containing polysiloxane having a plurality of carboxyl groups and having a structure represented by the following formula (1).

Wherein (1), a is an integer of 0 to 50, b is an integer of 3 to 300, ^{R 1} is an alkyl group having 1 to 6 carbon atoms, ^{X 1} is the following formula (2) or - (CH _{2) n} -COOH (where, n is a substituent represented by an integer) of 1 to 20, ^{X 2} is a substituent represented by ^{R 1} or the following formula (2) (where, a = 0 X ² ≠ R ¹ ), R ¹ and X ¹ may be the same or different. ]

Wherein (2), ^{R 2} is an alkylene group or alkylene oxyalkylene group having 1 to 10 carbon atoms, k is 0 or 1. ]
Component (B): An alicyclic epoxy group-containing cage silsesquioxane having a plurality of alicyclic epoxy groups and having a structure represented by the following formula (3).

[In Formula (3), R ⁶ is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, R ⁷ is an alkylene group or alkyleneoxyalkylene group having 1 to 10 carbon atoms, and R ⁸ is 1 carbon atom. ˜4 alkyl group, R ⁹ is an alkyl group having 1 to 4 carbon atoms, m is an integer of 1 to 3, R ⁵ is a substituted or unsubstituted alkyl group, r is selected from 6, 8, 10 and 12. P, an integer of 2 to r, and q represents an integer of 0 to (rp). ]