JP2012144590A - Curing composition, cured film, and semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing composition excellent in storage stability, and a cured film having well balancedly exfoliation resistance, light resistance, cracking resistance, gas barrier property, curability, transparency and wet heat resistance.SOLUTION: The curing composition includes [A] a polyorganosiloxane containing an epoxy group and a thiol group, and [B] a curing agent for epoxy, wherein the thiol equivalent weight in [A] the polyorganosiloxane is ≥8,000 and ≤100,000. The epoxy equivalent weight in [A] the polyorganosiloxane is preferably ≥350 and ≤450.

Description

  The present invention relates to a curable composition, a cured film, and a semiconductor light emitting device.

  The light emitting element of an optical semiconductor element such as an LED deteriorates its light emission characteristics when moisture in the atmosphere or floating dust enters. Therefore, the optical semiconductor element has a structure in which the space between the phosphor and the package base material is sealed with a sealing material. As the sealing material, in addition to durability such as light resistance and heat resistance, it is necessary to satisfy adhesion with a package substrate.

  In recent years, the brightness of LEDs has been increasing, and the amount of heat generated during lighting tends to increase. For this reason, high heat resistance and light resistance are requested | required of the sealing material for optical semiconductor elements. However, an epoxy resin that has been conventionally used as a sealing material for an optical semiconductor element is inferior in durability, and therefore has a disadvantage that it cannot cope with an increase in brightness of an LED.

  In order to eliminate this inconvenience, for example, Japanese Patent Application Laid-Open Nos. 2004-289102 and 2005-171021 disclose a sealing material using an epoxy group-containing polyorganosiloxane. Japanese Patent Application Laid-Open No. 2009-263531 discloses a method of adding a phenolic antioxidant to a sealing material containing an epoxy group-containing polyorganosiloxane.

JP 2004-289102 A JP 2005-171021 A JP 2009-263531 A

  The present invention has been made in view of these disadvantages, and the object thereof is a curable composition having excellent storage stability, as well as peeling resistance, light resistance, crack resistance, gas barrier properties, curability, transparency, and moisture and heat resistance. Is to provide a cured film having a good balance.

The invention made to solve the above problems is
[A] a polyorganosiloxane having an epoxy group and a thiol group (hereinafter also referred to as “[A] polyorganosiloxane”), and [B] a curing agent for epoxy,
[A] A curable composition having a thiol equivalent in a polyorganosiloxane of 8,000 or more and 100,000 or less.

  [A] The epoxy equivalent in the polyorganosiloxane is preferably 350 or more and 450 or less.

（式（１）中、
Ｒ^１は、チオール基を有する炭素数１〜２０の直鎖状若しくは分岐状のアルキル基又は炭素数３〜２０の環状アルキル基である。
Ｒ^２は、炭素数１〜２０の直鎖状若しくは分岐状のアルキル基、アルコキシ基、炭素数３〜２０の環状アルキル基又はシラノール基である。
但し、これらの基の水素原子の一部又は全部は、置換されていてもよい。また、これらの基の炭素鎖中に酸素原子、硫黄原子又は窒素原子を有していてもよい。
ｐは、１又は２である。但し、Ｒ^１及びＲ^２がそれぞれ複数存在する場合、複数のＲ^１及びＲ^２はそれぞれ同一でも異なっていてもよい。） [A] The polyorganosiloxane preferably has a structural unit represented by the following formula (1).

(In the formula (1),
R ¹ is a linear or branched alkyl group having 1 to 20 carbon atoms having a thiol group or a cyclic alkyl group having 3 to 20 carbon atoms.
R ² is a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxy group, a cyclic alkyl group having 3 to 20 carbon atoms, or a silanol group.
However, some or all of the hydrogen atoms of these groups may be substituted. Moreover, you may have an oxygen atom, a sulfur atom, or a nitrogen atom in the carbon chain of these groups.
p is 1 or 2. However, if the R ¹ and R ² are present in plural, it may be different in each of a plurality of R ¹ and R ² are the same. )

（式（２）中、
Ｒ^３は、エポキシ基を含有する炭素数１〜２０の直鎖状若しくは分岐状のアルキル基又は炭素数３〜２０の環状アルキル基である。これらの基の水素原子の一部又は全部は、置換されていてもよい。また、これらの基の炭素鎖中に酸素原子、硫黄原子又は窒素原子を有していてもよい。
Ｒ^４は、上記式（１）のＲ^２と同義である。
ｑは、１又は２の整数である。但し、Ｒ^３及びＲ^４がそれぞれ複数存在する場合、複数のＲ^３及びＲ^４はそれぞれ同一でも異なっていてもよい。） [A] The polyorganosiloxane preferably has a structural unit represented by the following formula (2).

(In the formula (2),
R ³ is a linear or branched alkyl group having 1 to 20 carbon atoms or an cyclic alkyl group having 3 to 20 carbon atoms containing an epoxy group. Some or all of the hydrogen atoms of these groups may be substituted. Moreover, you may have an oxygen atom, a sulfur atom, or a nitrogen atom in the carbon chain of these groups.
R ⁴ has the same meaning as R ^{2 in the} above formula (1).
q is an integer of 1 or 2. However, if R ³ and R ⁴ are present in plural, may be different in each of a plurality of R ³ and R ⁴ are the same. )

  The curable composition preferably further contains a [C] antioxidant.

  [B] The epoxy curing agent is preferably an acid anhydride.

  The present invention includes a cured film obtained from the curable composition and a semiconductor light emitting device comprising the cured film.

  According to the present invention, it is possible to provide a curable composition having excellent storage stability, and a cured film having a good balance of peel resistance, light resistance, crack resistance, gas barrier properties, curability, transparency, and moist heat resistance. Therefore, the cured film can be suitably used for a semiconductor light emitting device or the like.

An example of the schematic diagram of the semiconductor light-emitting device using a cured film. An example of the schematic diagram of the semiconductor light-emitting device using a cured film.

<Curable composition>
The curable composition of the present invention contains [A] polyorganosiloxane and [B] epoxy curing agent, and the thiol equivalent (g / eq) in the [A] polyorganosiloxane is 8,000 or more and 100,000. It is as follows. The curable composition may further contain other optional components. Hereinafter, each component will be described in detail.

<[A] polyorganosiloxane>
[A] The polyorganosiloxane has an epoxy group and a thiol group and has a polyorganosiloxane structure. [A] Since the polyorganosiloxane has a thiol group, the cured film formed from the curable composition is excellent in peeling resistance to the package substrate. Moreover, when the thiol group equivalent in [A] polyorganosiloxane is from 8,000 to 100,000, the cured film formed from the curable composition balances durability such as light resistance. Can have well.

  [A] The polyorganosiloxane preferably has a structural unit represented by the above formula (1).

In the above formula (1), R ¹ is a linear or branched alkyl group or a cyclic alkyl group having 3 to 20 carbon atoms having 1 to 20 carbon atoms having a thiol group. R ² is a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxy group, a cyclic alkyl group having 3 to 20 carbon atoms, or a silanol group. However, some or all of the hydrogen atoms of these groups may be substituted. Moreover, you may have an oxygen atom, a sulfur atom, or a nitrogen atom in the carbon chain of these groups. p is 1 or 2. However, if the R ¹ and R ² are present in plural, it may be different in each of a plurality of R ¹ and R ² are the same.

  [A] The polyorganosiloxane preferably has a structural unit represented by the above formula (2).

In the above formula (2), R ³ is a linear or branched alkyl group or a cyclic alkyl group having 3 to 20 carbon atoms having 1 to 20 carbon atoms containing an epoxy group. Some or all of the hydrogen atoms of these groups may be substituted. Moreover, you may have an oxygen atom, a sulfur atom, or a nitrogen atom in the carbon chain of these groups. R ⁴ has the same meaning as R ^{2 in the} above formula (1). q is an integer of 1 or 2. However, if R ³ and R ⁴ are present in plural, may be different in each of a plurality of R ³ and R ⁴ are the same.

  Furthermore, [A] polyorganosiloxane can have a structural unit represented by the following formula (3).

In the above formula (3), R ⁵ and R ⁶ are each independently synonymous with R ² in the above formula (1).

  Examples of the linear or branched alkyl group having 1 to 20 carbon atoms in the above formulas (1) to (3) include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, linear alkyl group such as n-octadecyl group, i-propyl group, i-butyl group, t-butyl group, neopentyl group, Examples thereof include branched alkyl groups such as 2-hexyl group and 3-hexyl group.

  The cyclic alkyl group having 3 to 20 carbon atoms in the above formulas (1) to (3) may be polycyclic and may have an oxygen atom in the ring. Examples of the cyclic alkyl group include cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl, cyclooctyl, bornyl group, norbornyl group, adamantyl group and the like.

  Examples of the substituent in the above formulas (1) to (3) include a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a carbonyl group, a cycloalkyl group, an aryl group, and an alkoxy group (preferably having 1 to 20 carbon atoms). Alkoxy groups such as methoxy group, ethoxy group, propoxy group, n-butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, etc.), acyl group (preferably having 2 carbon atoms) An acyl group having ˜20, for example, an acetyl group, a propionyl group, a butyryl group, an i-butyryl group, and the like, an acyloxy group (preferably an acyloxy group having 2 to 10 carbon atoms, for example, an acetoxy group, an ethylyloxy group , Butyryloxy group, t-butyryloxy group, t-amylyloxy group and the like), Lucoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, etc.), haloalkyl group (for example, perfluoromethyl group, perfluoroethyl group) Group, perfluoropropyl group, fluorocyclopropyl group, fluorocyclobutyl group, etc.).

R ¹ in the above formula (1) is, for example, a mercaptoalkyl group such as a mercaptomethyl group, a 2-mercaptoethyl group or a 3-mercaptopropyl group; a mercaptocycloalkyl group such as a 4-mercaptocyclohexyl group or a 4-mercaptomethylcyclohexyl group. Groups, mercaptoaryl groups such as p-mercaptophenyl group and p-mercaptomethylphenyl group. Of these, a 3-mercaptopropyl group is preferred.

R ³ in the above formula (2) is, for example, a glycidoxyalkyl group such as β-glycidoxyethyl group or γ-glycidoxypropyl group; an epoxy such as 3,4-epoxycyclopentyl group or 3,4-epoxycyclohexyl group. A cycloalkyl group; an epoxycycloalkyl group such as a 2- (3,4-epoxycyclopentyl) ethyl group, a 2- (3,4-epoxycyclohexyl) ethyl group, and a 3- (3,4-epoxycyclohexyl) propyl group; And an alkyl group having. Among these organic groups, an organic group having an epoxycycloalkyl group is preferable from the viewpoint of stability in the reaction with water described later, and 2- (3,4-epoxycyclohexyl) ethyl group, 3- (3,4- An epoxycycloalkyl) propyl group is more preferred.

<[A] Synthesis method of polyorganosiloxane>
[A] Examples of the synthesis method of polyorganosiloxane include a method of condensing a thiol group-containing alkoxysilane and an epoxy group-containing alkoxysilane with another organosilane (for example, polydimethylsiloxane having a silanol group at the terminal), the terminal, etc. And a method of reacting a polyorganosiloxane having a silanol group with a thiol group-containing alkoxysilane and an epoxy group-containing alkoxysilane. Among these, a method of reacting a thiol group-containing alkoxysilane and an epoxy group-containing alkoxysilane in a polyorganosiloxane having a silanol group at the terminal is preferable.

  The polyorganosiloxane having a silanol group at the terminal is not particularly limited as long as it is a polydimethylsiloxane having at least one silanol group at the terminal of the main chain and / or side chain. Such a compound can be produced, for example, by condensation polymerization of dimethyl dialkoxysilane or dimethyldichlorosilane.

  Examples of the dimethyl dialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-i-propoxysilane, and dimethyldi-n-butoxysilane. These dimethyl dialkoxysilanes can be used alone or in admixture of two or more.

  A polyorganosiloxane having a silanol group at the terminal can also be produced by ring-opening condensation of a cyclic organosiloxane. Examples of the cyclic organosiloxane used at this time include hexaphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, pentamethylcyclotetrasiloxane, hexamethyl Examples thereof include methylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

  Examples of commercially available polyorganosiloxanes having silanol groups at the ends include YF-3057, YF-3800, YF-3802, YF-3807, YF-3897, XF-3905 (above, manufactured by GE Toshiba Silicone), XC- 96-723 (made by Momentive) etc. are mentioned.

  The polydimethylsiloxane having a terminal silanol group preferably has a polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography of 1,000 to 100,000, more preferably 1,500 to 80,000. 2,000 to 70,000 is particularly preferable. By setting Mw within the specific range, [A] polyorganosiloxane has excellent performance in viscosity and thick film formability.

  As said thiol group containing alkoxysilane, the compound represented by following formula (4) is mentioned.

In the above formula (4), ^{R 7} has the same meaning as ^{R 1} in the formula (1). R ⁸ and R ⁹ are each independently synonymous with R ^{2 in the} above formula (1). r is an integer of 1 to 3. s is an integer of 1 to 3. However, r + s satisfies the condition of 4 or less.

Examples of the thiol group-containing alkyl group represented by R ⁷ include the same thiol group-containing alkyl groups in the above formula (1).

  Examples of the thiol group-containing alkoxysilane include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyldimethoxyethoxysilane, γ-mercaptopropyldiethoxymethoxysilane, γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropyldiethoxymethylsilane and the like can be mentioned. Of these, 2-mercaptoethyl (trimethoxy) silane, γ-mercaptopropyltrimethoxysilane, and 2-mercaptoethyl (trimethoxy) silane are preferable, and γ-mercaptopropyltrimethoxysilane and 2-mercaptoethyl (trimethoxy) silane are more preferable. preferable.

  As said epoxy group containing alkoxysilane, the compound represented by following formula (5) is mentioned.

In the above formula ^{(5), R 10} has the same meaning as ^{R 3} in the formula (2). R ¹¹ and R ¹² have the same meaning as R ^{2 in the} above formula (1). t is an integer of 1 to 3. u is an integer of 1 to 3. However, t + u satisfies the condition of 4 or less.

Examples of the epoxy group-containing alkyl group represented by R ¹⁰ in the formula (5) include the same hydrocarbon groups as those in the formula (2).

  As a synthesis route, polydimethylsiloxane having a silanol group at the terminal, an epoxy group-containing alkoxysilane, and a thiol group-containing alkoxysilane are reacted, and the above formula (1), formula (2) and, if necessary, formula A polyorganosiloxane in which the structural unit represented by (3) is bonded to the terminal is generated (hereinafter also referred to as “reaction 1”). Next, a polyorganosiloxane having an epoxy group and a thiol group is obtained by hydrolytic condensation of the produced polyorganosiloxane in the presence of water (hereinafter also referred to as “reaction 2”).

  The reaction time for the above reaction 1 is preferably 1 hour to 48 hours, more preferably 1.5 hours to 24 hours, and particularly preferably 2 hours to 12 hours. The above reaction may be carried out by charging each component in a reaction vessel at once, or may be carried out while adding the other component intermittently or continuously to one component.

  The reaction 1 causes a dealcoholization reaction to produce a polyorganosiloxane having structural units represented by the above formulas (1), (2), and (3). In the above reaction 1, all of the silanol groups in the polydimethylsiloxane having a silanol group at the terminal may react or a part may remain in a silanol group state.

  By reaction 2, the polyorganosiloxane having the structural unit represented by the above formula (1), formula (2) and formula (3) is hydrolytically condensed. Thereby, [A] polyorganosiloxane which has a thiol group and an epoxy group is obtained.

  The reaction time for Reaction 2 is preferably 0.1 hour to 48 hours, more preferably 0.2 hours to 24 hours, and particularly preferably 0.5 hours to 12 hours.

  The amount of water used in Reaction 2 is preferably 10 parts by mass or more and 500 parts by mass or less, and 20 parts by mass with respect to 100 parts by mass of the total of the alkoxysilane used in Reaction 1 and the polysiloxane having a silanol group at the terminal. Part to 200 parts by mass is more preferable, and 30 parts to 100 parts by mass is particularly preferable. By setting the amount of water to be in the above range, the reaction proceeds sufficiently and the amount of water that needs to be removed after the reaction can be reduced.

  Reaction 1 and reaction 2 are preferably performed using a catalyst in an organic solvent. As the catalyst used at this time, the catalyst used in the above reaction 1 may be used continuously, or the same or different catalyst may be newly used. As temperature of the said reaction 1 and reaction 2, 5 to 100 degreeC is preferable, 10 to 80 degreeC is more preferable, 15 to 50 degreeC is especially preferable.

  Examples of the organic solvent used in the above reaction 1 and reaction 2 include alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like. Among the above organic solvents, organic solvents other than alcohols are preferable from the viewpoint of reaction acceleration, and methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene are preferable. The organic solvent is preferably used in a state where moisture has been removed by dehydration in advance. The usage-amount of the said organic solvent can be suitably set according to desired conditions.

  As a catalyst used for the said reaction 1 and reaction 2, a basic compound, an organotin compound, this partial hydrolysis compound, etc. are mentioned, for example.

  Examples of the basic compound include ammonia (including aqueous ammonia), organic amine compounds, hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide and potassium hydroxide; sodium methoxide, sodium ethoxide and the like. Examples thereof include alkali metal alkoxides. Examples of the organic amine compound include alkylamines, alkoxyamines, alkanolamines, and arylamines.

  Of these basic compounds, ammonia and organic amine compounds are preferable, and triethylamine, pyrrolidine, tetramethylammonium hydroxide, pyridine, and diazabicycloundecene are more preferable. In addition, the said basic compound can be used individually or in mixture of 2 or more types.

Examples of the organotin compounds include tetravalent tin organometallic compounds in which one or two alkyl groups having 1 to 10 carbon atoms are bonded to one tin atom. Examples of the organic tin compounds include carboxylic acid type organic tin compounds, mercaptide type organic tin compounds, sulfide type organic tin compounds, chloride type organic tin compounds, (C ₄ H ₉ ) ₂ SnO, and (C ₈ H ₁₇ ) ₂ SnO. And the like, and reaction products of these organotin oxides with silicates, ester compounds such as dimethyl maleate, diethyl maleate, and dioctyl phthalate.

  In the above reaction 1, the addition amount of the catalyst is 0.5 parts by mass or more and 15 parts by mass with respect to 100 parts by mass in total of the polyorganosiloxane having a silanol group at the terminal, the epoxy group-containing alkoxysilane and the thiol group-containing alkoxysilane. Part or less, preferably 1.0 part by weight or more and 10 parts by weight or less, more preferably 2 parts by weight or more and 8 parts by weight or less.

  In the above reaction 2, the addition amount of the catalyst is 0.5 parts by mass or more and 15 parts by mass with respect to 100 parts by mass in total of the polydimethylsiloxane having a silanol group at the terminal, the epoxy group-containing alkoxysilane, and the thiol group-containing alkoxysilane. Part or less, preferably 1.0 part by weight or more and 10 parts by weight or less, more preferably 2 parts by weight or more and 8 parts by weight or less.

  Moreover, when the said reaction 2 is performed after the said reaction 1, the catalyst used for the said reaction may be used as it is, and the same kind or different kind of catalyst may be newly added.

  [A] The polyorganosiloxane obtained by the above reaction 1 and reaction 2 is preferably washed with water as a decatalyzing step after the above reaction 2 from the viewpoint of storage stability. In particular, when a basic compound is used as a catalyst, it is preferable to perform water washing after neutralization with an acidic compound after the reaction.

  Examples of acidic compounds used for neutralization include organic acids and inorganic acids. Examples of the organic acid include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, maleic anhydride, methylmalonic acid, adipic acid, sebacin Acid, gallic acid, butyric acid, meritic acid, arachidonic acid, mikimic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid Benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, lactic acid, malic acid, succinic acid, glutaric acid, malonic acid, methanesulfonic acid, phthalic acid, fumaric acid, citric acid, tartaric acid, etc. Can be mentioned. Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, boric acid, and carbonic acid.

  The amount of the acidic compound used is preferably 0.5 N or more and 2 N or less, more preferably 0.8 N or more and 1.5 N or less, with respect to 1 N of the basic compound used in the above Reaction 1 and Reaction 2. Particularly preferred is 0.9 or more and 1.3 or less. Moreover, since it is easy to extract to a water layer at the time of washing with water, it is preferable to use a water-soluble acidic compound. When used by dissolving in water, the addition amount of the acidic compound is preferably 0.5 parts by mass or more and 100 parts by mass or less, more preferably 1 part by mass or more and 50 parts by mass or less, with respect to 100 parts by mass of water. Particularly preferred is from 10 to 10 parts by weight.

  After the decatalyzing step, washing with water (sufficient stirring and mixing is allowed to stand, and after confirming phase separation between the aqueous phase and the organic solvent phase, the lower layer moisture is removed) is performed. The amount of water used for water washing after neutralization is preferably 10 parts by mass or more and 500 parts by mass or less with respect to a total of 100 parts by mass of the polydimethylsiloxane having a silanol group at the terminal and the epoxy group-containing alkoxysilane. 20 mass parts or more and 300 mass parts or less are more preferable, and 30 mass parts or more and 200 mass parts or less are especially preferable. In addition, the frequency | count of water washing is 1 time or more, and 2 times or more are more preferable.

  The neutralization reaction time is preferably from 0.1 hours to 48 hours, more preferably from 0.2 hours to 24 hours, and particularly preferably from 0.5 hours to 12 hours.

  [A] The blending amount of the hydroxy-terminated polyorganosiloxane, the epoxy group-containing alkoxysilane and the thiol group-containing alkoxysilane in the polyorganosiloxane is not particularly limited as long as the [A] polyorganosiloxane exhibits a desired effect.

  [A] The epoxy equivalent (g / eq) of the polyorganosiloxane is preferably 350 to 450, more preferably 360 to 440, and particularly preferably 380 to 430. By setting the epoxy equivalent in the specific range, the cured film obtained from the curable composition is further excellent in adhesion to the package substrate and can also improve durability. [A] The epoxy equivalent of the polyorganosiloxane can be measured according to JIS C2105.

  The thiol equivalent (g / eq) in the [A] polyorganosiloxane is from 8,000 to 100,000, more preferably from 8,000 to 80,000, particularly preferably from 9,000 to 70,000. preferable. When the thiol equivalent is 8,000 or more and 100,000 or less, there is a characteristic that the balance of adhesion, heat resistance, and light resistance is excellent. The thiol equivalent is a value defined by the molecular weight of polyorganosiloxane per thiol group.

  [A] The thiol equivalent of polyorganosiloxane can be measured by titration of excess iodine with a standard sodium thiosulfate solution after oxidation with iodine.

<[B] Curing agent for epoxy>
[B] A curing agent for epoxy is a substance that cures [A] polyorganosiloxane and an epoxy group-containing compound described later. [B] Examples of epoxy curing agents include organic hydrazides such as acid anhydrides, amine compounds, mercapto compounds, phenols, dicyandiamides, adipic hydrazides, and phthalic hydrazides. Of these, acid anhydrides are preferred, and alicyclic carboxylic acid anhydrides are more preferred. [B] By containing these compounds as a curing agent for epoxy, the crosslinking reaction proceeds sufficiently, and the sealed body using the curable composition can further improve the durability.

  Examples of the alicyclic carboxylic acid anhydride include 4-methyltetrahydrophthalic acid anhydride, methyl nadic acid anhydride, dodecenyl succinic acid anhydride, and compounds represented by the following formulas (6-1) to (6-11). , A Diels-Alder reaction product of an alicyclic compound having a conjugated double bond such as α-terpinene and alloocimene and maleic anhydride, and a hydrogenated product thereof.

  Arbitrary structural isomers and arbitrary geometric isomers can be used as the Diels-Alder reaction products and hydrogenated products thereof. Moreover, the said alicyclic carboxylic acid anhydride can also be chemically modified | denatured and used suitably, unless the hardening reaction is prevented substantially.

  Among the alicyclic carboxylic acid anhydrides, from the viewpoint of fluidity and transparency of the composition, the above formulas (6-1), (6-2), (6-3), (6-5), ( 6-6), (6-9) and (6-11) are preferred, and the compounds represented by formulas (6-1), (6-2), (6-3), (6-6) and (6) The compound represented by 6-11) is more preferable.

  [B] The epoxy curing agent can be used alone or in admixture of two or more. Moreover, an aliphatic acid anhydride or an aromatic acid anhydride can also be used as the acid anhydride. The aliphatic acid anhydride and aromatic acid anhydride are preferably used in combination with an alicyclic acid anhydride. The aliphatic acid anhydride and the aromatic acid anhydride can be used after being appropriately chemically modified as long as the curing reaction is not substantially hindered. 50 mass% or less is preferable with respect to the total amount with the said alicyclic acid anhydride, and, as for the total usage-amount of the said aliphatic acid anhydride and aromatic acid anhydride, 30 mass% or less is more preferable.

  The amount of the curing agent other than the acid anhydride is preferably 50% by mass or less, and more preferably 30% by mass or less based on the acid anhydride.

  The amount of the curing agent for [B] epoxy used in the present invention is 0.1 mole or more and 2.Mole ratio of 1 mole of the total epoxy groups contained in the polyorganosiloxane and the epoxy group-containing compound described later. 0 mol or less is preferable, 0.3 mol or more and 1.8 mol or less is more preferable, and 0.5 mol or more and 1.5 mol or less is particularly preferable. [B] By making the usage-amount of the hardening | curing agent for epoxy into the said specific range, problems, such as a fall of the glass transition point (Tg) of the hardened | cured material obtained and coloring of hardened | cured material, can be suppressed.

<[C] Antioxidant>
The curable composition preferably further contains a [C] antioxidant. Since the [C] antioxidant captures radicals generated by light and heat, the encapsulant using the curable composition is reduced in light resistance and heat resistance caused by the action of the radicals, and is applied to a package substrate. It is possible to prevent a decrease in the adhesion.

  [C] Examples of the antioxidant include phenol-based, amine-based, phosphorus-based and sulfur-based antioxidants.

  Examples of the phenolic antioxidant include thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris. (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,3 ′, 3 ′, 5 ′, 5′-hexa-tert-butyl-a, a ′, a ′-(mesitylene-2 , 4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, 4,6-bis (dodecylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate, 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylin) Til] -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1, 3,5-triazin-2-ylamine) phenol, a compound represented by the following formula (7), and the like.

  [C] The antioxidant is preferably a phenolic antioxidant, and more preferably a compound represented by the following formula (7).

In formula (7), R ¹³ is an n-valent hydrocarbon group. The carbon chain of the n-valent hydrocarbon group may have an oxygen atom, a sulfur atom, a nitrogen atom or —COO—. X is a single bond, —O—, —COO—, —CO— or —NH—CO—. R ¹⁴ is a C 1-10 divalent linear or branched aliphatic hydrocarbon group or a C 3-10 divalent cyclic aliphatic hydrocarbon group. R ¹⁵ is a branched alkyl group having 4 to 10 carbon atoms. R ¹⁶ is a linear or branched alkyl group having 1 to 10 carbon atoms. However, some or all of the hydrogen atoms of these groups may be substituted. n is an integer of 1-10. However, when n is 2 or more, some of the hydroxyl groups in the plurality of phenol skeletons may be esterified with (meth) acrylic acid.

  Examples of the n-valent hydrocarbon group include a linear or branched hydrocarbon group obtained by removing n hydrogen atoms from a hydrocarbon group having 1 to 20 carbon atoms, or a cyclic hydrocarbon group having 3 to 20 carbon atoms. A cyclic hydrocarbon group in which n hydrogen atoms are removed. This cyclic hydrocarbon group may be polycyclic and may have an oxygen atom in the ring.

  Examples of the divalent linear or branched aliphatic hydrocarbon group having 1 to 10 carbon atoms or the divalent cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms include, for example, a methylene group, an ethylene group, and n 1 to 10 carbon atoms such as -propylene group, i-propylene group, n-butylene group, n-pentylene group, n-hexylene group, n-heptylene group, n-octylene group, n-nonylene group, n-decylene group A divalent linear or branched hydrocarbon group; a cyclobutanediyl group, a cyclopentanediyl group, a cyclohexanediyl group, a cyclooctanediyl group, a norbornanediyl group, a tricyclodecanediyl group, a tetracyclododecanediyl group, Examples thereof include a C 3-10 divalent alicyclic hydrocarbon group such as an adamantanediyl group.

  Examples of the branched alkyl group having 4 to 10 carbon atoms include i-butyl group, t-butyl group, t-amyl group, neopentyl group, 2-hexyl group, and 3-hexyl group.

  Examples of the monovalent linear or branched alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, and n. -Linear alkyl groups such as octyl group and n-decyl group, branched alkyl groups such as i-propyl group, i-butyl group, t-butyl group, neopentyl group, 2-hexyl group, 3-hexyl group, etc. Is mentioned.

In the formula (1), the bonding position of R ¹⁶ is preferably a carbon atom adjacent to the carbon atom to which the phenolic hydroxyl group is bonded, from the viewpoint of radical scavenging ability.

  Examples of the compound represented by the formula (7) include compounds represented by the following formulas (7-1) to (7-7).

  Examples of the amine-based antioxidant include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis ( 1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (N-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-benzyloxy-2, 2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-cyclohexyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6) -Pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1-acryloyl-2,2,6,6-teto Methyl-4-piperidyl) 2,2-bis (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1,2,2,6,6-pentamethyl-4- Piperidyl) decanedioate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -1- [ 2- (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy) ethyl] -2,2,6,6-tetramethylpiperidine, 2-methyl-2- (2,2, 6,6-tetramethyl-4-piperidyl) amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1) Compounds such as 2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, N, N ′, N ″, N ′ ″-tetrakis- [4,6-bis- [butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino] -triazin-2-yl ] -4,7-diazadecane-1,10-diamine, dibutylamine and 1,3,5-triazine-N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) -1, Polycondensation product of 6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, dibutylamine, 1,3,5-triazine and N, N′-bis (2 , 2,6,6-tetramethyl- Polycondensate with 4-piperidyl) butylamine, poly [{(1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6 , 6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], 1,6-hexanediamine-N, N′-bis (2 , 2,6,6-tetramethyl-4-piperidyl) and morpholine-2,4,6-trichloro-1,3,5-triazine, poly [(6-morpholino-s-triazine- 2,4-diyl) [(2,2,6,6-tetramethyl-4-piperidyl) imino] -hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] and the like Piperidine ring via the triazine skeleton Number-bound high molecular weight HALS, polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 1,2,3,4-butanetetracarboxylic acid and 1, 2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane And polymer types such as compounds in which piperidine rings such as mixed esterified compounds are bonded via an ester bond, compounds represented by the following formulas (8-1) and (8-2), and the like.

In the above formula (8-1), R ¹⁷ is represented by the following formula (9).

  In the above formula (9), * represents a bond.

  Examples of the phosphoric acid antioxidant include tris (nonylphenyl) phosphite, tris (p-tert-octylphenyl) phosphite, tris [2,4,6-tris (α-phenylethyl)] phosphite, tris (P-2-butenylphenyl) phosphite, bis (p-nonylphenyl) cyclohexyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, di (2,4-di-tert-butyl) Phenyl) pentaerythritol diphosphite, 2,2′-methylenebis (4,6-di-t-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, distearyl pentaerythritol diphosphite, 4,4 '-Isopropylide-diphenol alkyl phosphite, tetratridecyl-4,4 -Butylidene-bis (3-methyl-6-tert-butylphenol) diphosphite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene phosphite, 2,6-di-tert-butyl- 4-methylphenyl phenyl pentaerythritol diphosphite, 2,6-tert-butyl-4-methylphenyl phenyl pentaerythritol diphosphite, 2,6-di-tert-butyl-4-ethylphenyl stearyl Pentaerythritol diphosphite, di (2,6-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,6-di-tert-amyl-4-methylphenyl phenyl pentaerythritol diphosphite And compounds represented by the following formula: It is done.

  Examples of the sulfur-based antioxidant include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate). Pentaerythritol tetrakis (3-octadecyl thiopropionate), pentaerythritol tetrakis (3-myristyl thiopropionate), pentaerythritol tetrakis (3-stearyl thiopropionate), and the like.

  [C] Antioxidants can be used alone or in admixture of two or more. [C] The amount of the antioxidant used is preferably 0.01 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of [A] polyorganosiloxane. 0.2 parts by mass or more and 1.5 parts by mass or less is particularly preferable.

<Other optional components>
The curable composition can contain an epoxy group-containing compound, a curing accelerator, a metal oxide, and the like as other optional components.

[Epoxy group-containing compound]
The curable composition may include an epoxy group-containing compound containing at least two epoxy groups in the molecule. By including the epoxy group-containing compound, the sealing body using the curable composition further improves the adhesion to the package substrate.

  Examples of the epoxy group-containing compound include novolac type epoxy group-containing compounds, cresol novolac type epoxy group-containing compounds, triphenolalkane type epoxy group-containing compounds, aralkyl type epoxy group-containing compounds, biphenyl skeleton-containing aralkyl type epoxy group-containing compounds, and biphenyl. Type epoxy group-containing compound, dicyclopentadiene type epoxy group containing compound, heterocyclic type epoxy group containing compound, naphthalene ring containing epoxy group containing compound, bisphenol A type epoxy compound, bisphenol F type epoxy compound, stilbene type epoxy group containing compound, Trimethylolpropane type epoxy group-containing compound, terpene-modified epoxy group-containing compound, linear aliphatic epoxy group-containing compound obtained by oxidizing olefinic bond with peracid such as peracetic acid, alicyclic epoxy Containing compound, a sulfur atom-containing epoxy group-containing compound, compounds having alicyclic epoxy group-containing compound or a glycidoxy group or an epoxy cycloalkyl group. Among these, an alicyclic epoxy group-containing compound such as an epoxycycloalkyl group or a compound having a glycidoxyalkyl group is preferable.

  Examples of the compound having an epoxycycloalkyl group include compounds represented by the following formulas.

In the above formula, R ¹⁸ is a hydrogen atom or a methyl group. n is an integer of 1-20.

  As the epoxy group-containing compound, a compound having an epoxycycloalkyl group is more preferable, and (3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate is particularly preferable.

  The molecular weight of the epoxy group-containing compound is preferably from 100 to 1,500, and more preferably from 150 to 1,000. If the molecular weight of the epoxy group-containing compound is 100 or less, the volatility of the organic compound increases, so that the processing characteristics during use are significantly deteriorated. On the other hand, when the molecular weight of the epoxy group-containing compound exceeds 1,500, the dispersion stability is remarkably deteriorated, or the viscosity of the composition is increased, so that casting and molding processability are deteriorated.

  The content of the epoxy group-containing compound is preferably 5 parts by mass or more and 60 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, and more preferably 15 parts by mass or more and 40 parts by mass with respect to 100 parts by mass of [A] polyorganosiloxane. Part by mass or less is particularly preferable. When the content of the epoxy group-containing compound is within the above range, the sealing body using the curable composition further improves the adhesion to the package substrate.

[Curing accelerator]
The curable composition preferably contains a curing accelerator in order to accelerate the curing reaction between [A] polyorganosiloxane and [B] epoxy curing agent.

Examples of the curing accelerator include tertiary amines such as benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, cyclohexyldimethylamine, and triethanolamine;
2-methylimidazole, 2-n-heptylimidazole, 2-n-undecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenyl Imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1- (2-cyanoethyl) -2-methylimidazole, 1- (2-cyanoethyl) -2-n-undecylimidazole, 1- ( 2-cyanoethyl) -2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-di (Hydroxymethyl) imidazole, 1- (2-cyanoethyl) -2-fur Nyl-4,5-di [(2′-cyanoethoxy) methyl] imidazole, 1- (2-cyanoethyl) -2-n-undecylimidazolium trimellitate, 1- (2-cyanoethyl) -2-phenyl Imidazolium trimellitate, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')] ethyl-s -Triazine, 2,4-diamino-6- (2'-n-undecylimidazolyl) ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1 ' )] Ethyl-s-triazine, isocyanuric acid adduct of 2-methylimidazole, isocyanuric acid adduct of 2-phenylimidazole, and 2,4-diamino-6- [2'- Methylimidazolyl- (1 ′)] imidazole compounds such as isocyanuric acid adducts of ethyl-s-triazine;
Organophosphorus compounds such as diphenylphosphine, triphenylphosphine, triphenyl phosphite;
Benzyltriphenylphosphonium chloride, tetra-n-butylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide , Ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium acetate, tetra-n-butylphosphonium o, o-diethylphosphorodithionate, tetra-n-butylphosphonium benzotriazolate, tetra Phenylphosphonium tetraphenylborate, tetra-n-butylphosphonium tetrafluoroborate, tetra-n-butylphosphonium tetraphenylborate Quaternary phosphonium salts bets like;
Diazabicycloalkenes such as 1,8-diazabicyclo [5.4.0] undecene-7 and organic acid salts thereof;
Organometallic compounds such as zinc octylate, tin octylate, aluminum acetylacetone complex;
Boron compounds such as boron trifluoride and triphenyl borate;
Metal halides such as zinc chloride and stannic chloride;
High melting point dispersion type latent curing accelerators such as metal halide compounds, amine addition accelerators such as dicyandiamide and adducts of amine and epoxy resin;
A microcapsule type latent curing accelerator in which the surface of a curing accelerator such as an imidazole compound, an organic phosphorus compound or a quaternary phosphonium salt is coated with a polymer;
An amine salt type latent curing accelerator;
Latent curing accelerators such as high temperature dissociation type thermal cationic polymerization type latent curing accelerators such as Lewis acid salts and Bronsted acid salts;
Examples include tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, tetra-n-butylammonium chloride, UCAT18X (manufactured by SANAPRO), UCAT410 (manufactured by SANAPRO), and quaternary ammonium salts represented by the following formula. .

In the above formula, R ^{19 to} R ²² are each independently a monovalent linear or branched alkyl group having 1 to 20 carbon atoms or a cyclic alkyl group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms of these groups may be substituted.

  Among these curing accelerators, a cured product that is colorless and transparent and hardly discolors even when heated for a long time can be obtained. Ammonium salts are preferred.

  The said hardening accelerator can be used individually or in mixture of 2 or more types. The amount of the curing accelerator used is preferably 0.005 to 6 parts by mass, more preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of [A] polyorganosiloxane. More preferably, it is in the range of 05 parts by mass to 4 parts by mass. When the usage-amount of the said hardening accelerator is less than 0.005 mass part, there exists a tendency for the acceleration effect of hardening reaction to fall, On the other hand, when the usage-amount of the said hardening accelerator exceeds 6 mass parts, the hardened | cured material obtained May cause inconvenience such as coloring.

<Metal oxide>
The curable composition of the present invention may contain a metal oxide in addition to the above components. Examples of such metal oxides include silica particles, ZrO ₂ , Al ₂ O ₃ , AlGaAs, Al (OH) ₃ , Si ₃ N ₄ , Sn—In ₂ O ₃ , Sb—In ₂ O ₃ , MgF, CeF ₃ , CeO ₂ , 3Al ₂ O ₃ .2SiO ₂ , BeO, SiC, AlN, Fe, Co, Co—FeOx, CrO ₂ , Fe ₄ N, BaTiO ₃ , BaO—Al ₂ O ₃ —SiO ₂ , Ba ferrite , SmCo ₅ , YCo ₅ , CeCo ₅ , PrCo ₅ , Sm ₂ Co ₁₇ , Nd ₂ Fe ₁₄ B, Al ₄ O ₃ , α-Si, SiN ₄ , CoO, Sb—SnO ₂ , Sb ₂ O ₅ , MnO ₂ , MnB, Co ₃ O ₄ , Co ₃ B, LiTaO ₃ , MgO, MgAl ₂ O ₄ , BeAl ₂ O ₄ , ZrSiO ₄ , ZnSb, PbTe _{, GeSi, FeSi 2, CrSi 2} , CoSi 2, MnSi1.73, Mg 2 Si, β-B, BaC, BP, TiB 2, ZrB 2, HfB 2, Ru 2 Si 3, TiO 3, PbTiO 3, Al 2 _{TiO 5, Zn 2 SiO 4,} Zr 2 SiO 4, 2MgO 2 -Al 2 O 3 -5SiO 2, Nb 2 O 5, Li 2 O-Al 2 O 3 -4SiO 2, Mg ferrite, Ni ferrite, Ni-Zn Examples thereof include ferrite, Li ferrite, and Sr ferrite.

  The said metal oxide can be used individually or in combination of 2 or more types. Moreover, the particle | grains which consist of a composite of the said metal oxide can also be used. When silica particles are blended as the metal oxide, it can be used in the form of a powder, a solvent-based sol or colloid dispersed in a polar solvent such as isopropyl alcohol or a nonpolar solvent such as toluene. When used in a solvent-based sol or colloid form, the metal oxide may be distilled off after compounding. Moreover, in order to improve the dispersibility of a silica particle, you may use, after surface-treating with respect to the said metal oxide.

  The primary particle diameter of the silica particles as the metal oxide is preferably 0.0001 μm to 1 μm, more preferably 0.001 μm to 0.5 μm, and particularly preferably 0.002 μm to 0.2 μm.

  In the case of a silica particle solvent-based sol or colloid, the solid content concentration is preferably 0.01% by mass or more and 50% by mass or less, and more preferably 0.01% by mass or more and 40% by mass or less.

<Method for preparing curable composition>
The curable composition of the present invention is prepared by mixing [C] an antioxidant and other optional components as required in addition to [A] polyorganosiloxane and [B] epoxy curing agent. Usually, the curable composition is preferably prepared in a state dissolved or dispersed in a suitable solvent. The curable composition of this invention contains resin components, such as polysiloxane, as a main component, and is normally used in the state containing the hardening | curing agent component for hardening a resin component. The curable composition suppresses discoloration due to heat treatment for sealing semiconductor light-emitting elements and the like, and, in the case of using a phosphor, suppresses the precipitation of the phosphor due to heat treatment, so that the heat treatment is performed under the mildest conditions. For example, a contrivance is made to shorten the heat treatment time. As one of the devices, usually a highly reactive curing agent for epoxy is used, but such a composition containing a highly reactive curing agent and a resin component has poor storage stability. Is conceived. For this reason, a composition containing a resin component and a curing agent are usually prepared separately, and these are mixed and used immediately before sealing. Therefore, the curable composition may also be prepared as a resin composition containing a curing agent, but it is prepared as a resin composition that does not contain a curing agent, and the curing agent is used when the curable composition is used. It can also be mixed into the composition.

<Method for producing cured film>
A cured film is obtained by curing the curable composition by heating or the like. For example, after apply | coating the said curable composition on a board | substrate, a cured film can be manufactured by making it harden | cure by heating at 100 to 180 degreeC for 3 to 13 hours. In addition, you may perform manufacture of the said cured film in the process (step cure) which heats up in steps.

<Semiconductor light emitting device>
The cured film can be suitably used as a sealing material for semiconductor light emitting devices. 1 and 2 are examples of a semiconductor light emitting device using a cured film.

  The semiconductor light emitting device 1 of FIG. 1 mainly includes a light emitting device portion 2 and a package substrate 3. The light emitting element portion 2 and the package substrate 3 are sealed with a sealing material 4. The sealing material 4 contains a phosphor 5 in a dispersed manner. The phosphor 5 can convert the light emitted from the light emitting element portion to cause fluorescence. The electrode 6 is connected to the light emitting element portion 2 by a wire 7.

  The semiconductor light emitting device 11 of FIG. 2 mainly includes a light emitting device portion 12 and a package base material 13. The light emitting element portion 12 and the package substrate 13 are bonded by a binder 14. The binder 14 contains the phosphor 15 in a dispersed manner. The phosphor 15 can convert the light emitted from the light emitting element portion 12 and fluoresce it. A space between the binder 14 and the package substrate 13 is sealed with a sealing material 16. The electrode 17 is connected to the light emitting element unit 12 by a wire 18.

  As the light emitting element portion, for example, a visible light emitting element such as a red LED element, a blue LED element, and a white LED element, an invisible light emitting element such as an ultraviolet LED element, and an infrared LED element can be used.

  Hereinafter, although an example is given and an embodiment of the present invention is explained still more concretely, the present invention is not limited to these examples at all.

  The weight average molecular weight (Mw), thiol group content, and epoxy equivalent of the synthesized [A] polyorganosiloxane and the component corresponding to [A] polyorganosiloxane were measured under the following conditions.

[Weight average molecular weight]
Mw was measured by gel permeation chromatography (GPC) under the following conditions and indicated as a polystyrene equivalent value.
Measurement temperature: 40 ° C
Column: TSK-gelMultiporeH _XL- M (manufactured by Tosoh Corporation)
Mobile phase: Tetrahydrofuran Flow rate: 0.5 mL / min
Sample concentration: 5.0%
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

[Thiol group content]
The content of thiol groups was measured by titration with a standard sodium thiosulfate solution after excess oxidation with iodine.

[Epoxy equivalent]
Based on JIS C2105, the epoxy equivalent of the obtained polyorganosiloxane was measured.

<[A] Synthesis of polyorganosiloxane>
[Synthesis Example 1]
Mw = 700 hydroxy-terminated polydimethylsiloxane (Momentive XC96-723) 100 parts by mass, epoxy group-containing alkoxysilane as 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane 108 parts by mass, thiol group-containing alkoxysilane As a catalyst, 1 part by mass of γ-mercapto (propyl) trimethoxysilane and 14 parts by mass of triethylamine as a catalyst were mixed and reacted at 25 ° C. for 8 hours. To this reaction product, 414 parts by mass of methyl isobutyl ketone, 134 parts by mass of methanol and 134 parts by mass of water were added and subjected to a hydrolysis reaction at 25 ° C. for 1 hour, and then 233 parts by mass of a 6% by mass oxalic acid aqueous solution was added. The neutralization reaction was performed at room temperature for 1 hour. Thereafter, the aqueous layer was separated, and the organic phase was washed with 134 parts by mass of water. After performing this washing operation 3 times, the solvent was distilled off to obtain [A] polyorganosiloxane (A-1) containing a thiol group and an epoxy group. Mw of (A-1) was 2,000, thiol equivalent was 40,000, and epoxy equivalent was 400.

[Synthesis Example 2]
100 parts by mass of hydroxy-terminated polydimethylsiloxane, 108 parts by mass of 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 0.45 parts by mass of γ-mercapto (propyl) trimethoxysilane and 14 parts by mass of triethylamine are mixed, The reaction was carried out at 25 ° C. for 8 hours. To this reaction product, 414 parts by mass of methyl isobutyl ketone, 134 parts by mass of methanol and 134 parts by mass of water were added and subjected to a hydrolysis reaction at 25 ° C. for 1 hour, and then 233 parts by mass of a 6% by mass oxalic acid aqueous solution was added. The neutralization reaction was performed at room temperature for 1 hour. Thereafter, the aqueous layer was separated, and the organic phase was washed with 134 parts by mass of water. After performing this washing operation 3 times, the solvent was distilled off to obtain [A] polyorganosiloxane (A-2) containing a thiol group and an epoxy group. Mw of (A-2) was 2,000, thiol equivalent was 90,000, and epoxy equivalent was 400.

[Synthesis Example 3]
100 parts by mass of hydroxy-terminated polydimethylsiloxane, 114 parts by mass of 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 4.8 parts by mass of γ-mercapto (propyl) trimethoxysilane and 14 parts by mass of triethylamine were mixed. The reaction was carried out at 0 ° C. for 8 hours. To this reaction product, 414 parts by mass of methyl isobutyl ketone, 134 parts by mass of methanol and 134 parts by mass of water were added and subjected to a hydrolysis reaction at 25 ° C. for 1 hour, and then 233 parts by mass of a 6% by mass oxalic acid aqueous solution was added. The neutralization reaction was performed at room temperature for 1 hour. Thereafter, the aqueous layer was separated, and the organic phase was washed with 134 parts by mass of water. After performing this washing operation 3 times, the solvent was distilled off to obtain [A] polyorganosiloxane (A-3) containing a thiol group and an epoxy group. Mw of (A-3) was 2,000, the thiol equivalent was 8,900, and the epoxy equivalent was 420.

[Synthesis Example 4]
100 parts by mass of hydroxy-terminated polydimethylsiloxane having Mw = 700, 108 parts by mass of 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane and 14 parts by mass of triethylamine were mixed and reacted at 25 ° C. for 8 hours. To this reaction product, 414 parts by mass of methyl isobutyl ketone, 134 parts by mass of methanol and 134 parts by mass of water were added and subjected to a hydrolysis reaction at 25 ° C. for 1 hour, and then 233 parts by mass of a 6% by mass oxalic acid aqueous solution was added. The neutralization reaction was performed at room temperature for 1 hour. Thereafter, the aqueous layer was separated, and the organic phase was washed with 134 parts by mass of water. After performing this washing operation three times, the solvent was distilled off to obtain an epoxy group-containing polyorganosiloxane (CA-1). Mw of (CA-1) was 2,000 and epoxy equivalent was 400.

[Synthesis Example 5]
100 parts by weight of hydroxy-terminated polydimethylsiloxane, 108 parts by weight of 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 0.1 part by weight of γ-mercapto (propyl) trimethoxysilane and 14 parts by weight of triethylamine are mixed, The reaction was carried out at 25 ° C. for 8 hours. To this reaction product, 414 parts by mass of methyl isobutyl ketone, 134 parts by mass of methanol and 134 parts by mass of water were added and subjected to a hydrolysis reaction at 25 ° C. for 1 hour, and then 233 parts by mass of a 6% by mass oxalic acid aqueous solution was added. The neutralization reaction was performed at room temperature for 1 hour. Thereafter, the aqueous layer was separated, and the organic phase was washed with 134 parts by mass of water. After performing this washing operation 3 times, the solvent was distilled off to obtain [A] polyorganosiloxane (CA-2) containing a thiol group and an epoxy group. Mw of (CA-2) was 2,000, thiol equivalent was 400,000, and epoxy equivalent was 400.

<Preparation of curable composition>
[Example 1]
[A] A mixture of 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 7/3 as a curing agent for epoxy (B) Manufactured by MH700) in a molar ratio of 0.9 mol with respect to 1 mol of an epoxy group contained in A-1 and (3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) 20 parts by mass of (3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) (manufactured by Daicel Chemical, CEL2021) as an epoxy group-containing compound and an amine curing accelerator (manufactured by San Apro, UCAT410) ) Was added to 0.2 parts by mass and sufficiently stirred to obtain a curable composition (S-1).

[Example 2]
[A] 100 parts by mass of (A-2) as a polyorganosiloxane and 45 parts by mass of a mixture of 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 7/3 as a curing agent for [B] epoxy (0.9 mol in molar ratio to 1 mol of epoxy group contained in (A-2 and (3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate)) ( 3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) is added in an amount of 20 parts by mass, and 0.2 part by mass of an amine-based curing accelerator is added, followed by thorough stirring. S-2) was obtained.

[Example 3]
[A] 100 parts by mass of (A-3) as a polyorganosiloxane and 45 parts by mass of a mixture of [B] 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 7/3 as a curing agent for epoxy (0.9 mol in molar ratio to 1 mol of epoxy group contained in (A-3 and (3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate)) as an epoxy group-containing compound ( 3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) 20 parts by mass and amine-based curing accelerator 0.2 part by mass and sufficiently stirring the curable composition (S -3) was obtained.

[Example 4]
[A] 100 parts by mass of (A-1) as the polyorganosiloxane and 45 parts by mass of a mixture of [B] 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 7/3 as a curing agent for epoxy (C-1 as a molar ratio of 1 mole of epoxy group contained in (A-1 and (3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) to 1 mole), [C] antioxidant Of the phenolic antioxidant pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], (3 ′, 4′-epoxycyclohexane) methyl-3 as an epoxy group-containing compound , 4-epoxycyclohexanecarboxylate) and 20 parts by weight of amine curing accelerator and 0.2 part by weight The mixture was sufficiently stirred to obtain a curable composition (S-4).

[Comparative Example 1]
To 100 parts by mass of (CA-1), 45 parts by mass of a mixture of 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 7/3 as a curing agent for [B] epoxy (CA-1 and (3 ', 4'-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate)) in a molar ratio of 1 mol to 1 mol of epoxy group), (3', 4'-epoxy as an epoxy group-containing compound) A curable composition (CS-1) was obtained by adding 20 parts by mass of cyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) and 0.2 parts by mass of an amine-based curing accelerator and stirring sufficiently.

[Comparative Example 2]
[A] 100 parts by mass of (CA-2) as a polyorganosiloxane, 45 parts by mass of a mixture of [B] 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 7/3 as a curing agent for epoxy (0.9 mol in molar ratio to 1 mol of epoxy group contained in CA-2 and (3 ', 4'-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate)) ( 3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate) 20 parts by mass and amine-based curing accelerator 0.2 part by mass and sufficiently stirred, the curable composition (CS -2) was obtained.

<Evaluation>
The storage stability shown below was evaluated for the prepared (S-1) to (CS-2). Moreover, the cured film was manufactured on the conditions as described in evaluation methods, such as peel peeling resistance mentioned later and light resistance, and each evaluation was performed. The results are shown in Table 1.

[Storage stability]
(A-1) to (CA-2) as the components [A] contained in the prepared (S-1) to (CS-2), respectively, and sealed in a polyethylene container at room temperature for 1 month. The presence or absence of gelation was determined visually. Viscosity was measured at 25 ° C. with a BM viscometer (manufactured by Tokyo Keiki Co., Ltd.) for those that were not gelled. When the viscosity change rate before and after storage is 20% or less, the storage stability is “A” (determined that the storage stability of the curable composition is good), and the viscosity change rate before and after storage exceeds 20%. B "(determined that the storage stability of the curable composition was poor).

[Peel peeling resistance]
The prepared curable compositions (S-1) to (CS-2) were applied on a 5 cm square silver electrode plate so that the film thickness was 1 mm, dried and cured at 100 ° C. for 1 hour, and then 150 ° C. And dried and cured for 5 hours to produce a cured film. The obtained cured film was peeled off at a rate of 1 cm / min by an autograph (manufactured by Shimadzu Corp.), thereby measuring the adhesion strength between the silver electrode and the sealing body to determine peel peel resistance (N / cm ² ). When this value was 0.1 or more, peel peel resistance was judged to be good.

[Peeling resistance during moisture absorption and reflow]
The prepared curable compositions (S-1) to (CS-2) were poured into an LED package (surface mount type, top view type), dried and cured at 100 ° C. for 1 hour, and then at 150 ° C. for 5 hours. A semiconductor light emitting device having a cured film was produced by drying and curing. The obtained semiconductor light emitting device was stored in a constant temperature and humidity chamber (Espec Corp., PL-3KP) for 5 hours at 85 ° C. and 85% RH, and then used with a tabletop solder reflow device (manufactured by Senju Metal Industry, STR-2010). Then, the reflow process at MAX 260 ° C. for 10 seconds was performed twice. The presence or absence of peeling between the cured film after reflow treatment and the package resin was observed with an optical microscope. Ten semiconductor light emitting devices were manufactured and evaluated. “A” (determined as good) when no peeling occurred, “B” (determined as slightly good) when one or two semiconductor light emitting elements were peeled off, and a semiconductor light emitting element where peeling occurred. The case of 3 or more was designated as “C” (determined as defective).

[Light resistance]
The prepared curable compositions of (S-1) to (CS-2) were applied on quartz glass so that the dry film thickness was 1 mm, then dried and cured at 100 ° C. for 1 hour, and then at 150 ° C. for 5 hours. A cured film was produced by drying and curing for a period of time. The cured film was irradiated with UV light having an illuminance of 5000 mW / cm ² for 500 hours using a spot UV irradiation device (SP-VII, manufactured by USHIO INC.) In which light having a wavelength of 350 nm or less was cut. The appearance was visually observed. Regarding the light resistance of the cured film, “A” (determined as good) when there is no change in appearance, “B” (determined as slightly good) when yellowed, and “C” (determined as defective) when burned black. ).

[Heat-resistant]
The cured film produced in the same manner as the above light resistance test was stored at 150 ° C. for 1,000 hours, and the light transmittance at 460 nm of the cured film after storage was measured. Regarding the heat resistance of the cured film, the case where the transmittance after storage is 95% or more with respect to the transmittance before storage is "A" (determined as good), and the case where it is 80% to 95% is "B" (somewhat good) And “C” (determined as defective).

[Crack resistance]
Using a thermal shock tester (manufactured by ESPEC), a semiconductor light-emitting device having a cured film manufactured in the same manner as the above-described peel resistance test during moisture absorption / reflow is -40 ° C to 100 ° C at a temperature rising / falling rate of 1 ° C / min. Up to 1,000 heat cycle tests were conducted. After completion of the test, the semiconductor light-emitting device after the heat cycle test was visually confirmed by an optical microscope for the presence of peeling between the package and the cured film and cracking between the resins. The test was conducted with 10 semiconductor light emitting devices for one test. In the evaluation of crack resistance, “A” (determined as good) when no peeling or cracking occurred, B (determined as slightly good) when 1 or 5 occurrences of peeling and cracking occurred, peeling and cracking The number of occurrences of 6 to 10 was designated as “C” (determined as defective).

[Gas barrier properties]
A semiconductor light-emitting element having a cured film produced in the same manner as the above-described peeling resistance test during moisture absorption / reflow is left in a pressure-resistant container, and hydrogen sulfide is poured into the container so that the concentration in the container becomes 10% by volume. Thereafter, the container was heated to 80 ° C. and allowed to stand for 24 hours to conduct a hydrogen sulfide exposure test. The state of discoloration of the silver electrode in the LED package was visually confirmed with an optical microscope. Gas barrier property (silver electrode discoloration suppressing ability) is “A” (determined good) when no discoloration is observed on the electrode surface, “B” (determined slightly good) when the electrode surface is slightly yellowed, electrode surface Was markedly black ("C").

[Curing property]
The prepared curable compositions of (S-1) to (CS-2) were poured into a Teflon (registered trademark) petri dish so that the dry film thickness was 2 mm, dried and cured in an oven at 100 ° C. for 1 hour, and then 150 A cured film was produced by drying and curing at 5 ° C. for 5 hours. The case where there was no fluidity and tack of this cured film was designated as “A” (determined as good), and the case where there was no fluidity but slight tack was designated as “B” (determined as defective).

[transparency]
The cured film produced in the same manner as the light resistance test was measured for spectral transmittance at a wavelength of 400 to 700 nm with an ultraviolet-visible spectrophotometer. Regarding the transparency of the sealing body, “A” (determined as good) when the light transmittance is 90% or more, and “B” (determined as slightly good) when the light transmittance is 70% or more and less than 90%. The case where the light transmittance was less than 70% was defined as “C” (determined as defective).

[Moisture and heat resistance]
About 2 g of the prepared curable compositions (S-1) to (CS-2) were accurately weighed in an aluminum dish, dried and cured at 100 ° C. for 1 hour, and then cured by drying at 150 ° C. for 5 hours. A membrane was produced. This cured film was stored for 14 days under conditions of a temperature of 85 ° C. and a humidity of 85% RH, and the mass retention rate was calculated from the mass before and after storage. The moisture and heat resistance of the cured film is “A” (determined as good) when the mass retention rate is 99% or more, “B” (determined as slightly good) when the mass retention rate is 95% or more and less than 99%, The case where the mass retention rate is less than 95% is defined as “C” (determined as defective).

  As is apparent from the results in Table 1, the curable composition is excellent in storage stability, and a cured film produced from the curable composition has a peel resistance, light resistance, heat resistance, crack resistance, and gas barrier properties. It was found that the resin composition had good balance between curability, transparency and heat and humidity resistance.

  According to the present invention, it is possible to provide a curable composition having excellent storage stability, and a cured film having a good balance of peel resistance, light resistance, crack resistance, gas barrier properties, curability, transparency, and moist heat resistance. Therefore, the cured film can be suitably used for a semiconductor light emitting device or the like.

DESCRIPTION OF SYMBOLS 1 Semiconductor light emitting element 2 Light emitting element part 3 Package base material 4 Sealing material 5 Phosphor 6 Electrode 7 Wire 11 Semiconductor light emitting element 12 Light emitting element part 13 Package base material 14 Binder 15 Phosphor 16 Sealing material 17 Electrode 18 Wire

Claims (8)

[A] a polyorganosiloxane having an epoxy group and a thiol group, and [B] a curing agent for epoxy,
[A] The curable composition whose thiol equivalent in polyorganosiloxane is 8,000 or more and 100,000 or less.   [A] The curable composition according to claim 1, wherein the epoxy equivalent in the polyorganosiloxane is 350 or more and 450 or less. [A] The curable composition according to claim 1, wherein the polyorganosiloxane has a structural unit represented by the following formula (1).

(In the formula (1),
R ¹ is a linear or branched alkyl group having 1 to 20 carbon atoms having a thiol group or a cyclic alkyl group having 3 to 20 carbon atoms.
R ² is a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxy group, a cyclic alkyl group having 3 to 20 carbon atoms, or a silanol group.
However, some or all of the hydrogen atoms of these groups may be substituted. Moreover, you may have an oxygen atom, a sulfur atom, or a nitrogen atom in the carbon chain of these groups.
p is 1 or 2. However, if the R ¹ and R ² are present in plural, it may be different in each of a plurality of R ¹ and R ² are the same. ) [A] The curable composition according to claim 1, wherein the polyorganosiloxane has a structural unit represented by the following formula (2).

(In the formula (2),
R ³ is a linear or branched alkyl group having 1 to 20 carbon atoms or an cyclic alkyl group having 3 to 20 carbon atoms containing an epoxy group. Some or all of the hydrogen atoms of these groups may be substituted. Moreover, you may have an oxygen atom, a sulfur atom, or a nitrogen atom in the carbon chain of these groups.
R ⁴ has the same meaning as R ^{2 in the} above formula (1).
q is an integer of 1 or 2. However, if R ³ and R ⁴ are present in plural, may be different in each of a plurality of R ³ and R ⁴ are the same. )   [C] The curable composition according to claim 1, further comprising an antioxidant.   [B] The curable composition according to claim 1, wherein the epoxy curing agent is an acid anhydride.   The cured film obtained from the curable composition of any one of Claims 1-6.   A semiconductor light emitting device comprising the cured film according to claim 7.

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