JP2013100410A - Curable epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable epoxy resin composition which gives a cured product that has high light reflectivity, is excellent in heat resistance and light resistance and is tough, and has light reflectivity difficult to deteriorate over time.SOLUTION: The curable epoxy resin composition comprises a cycloaliphatic epoxy compound (A), alumina (B), an aliphatic polyglycidyl ether (C) having a viscosity of 8,000 mPas or more at 25°C, and a white pigment (D). Preferably, the curable epoxy resin composition further comprises a curing agent (E) and a curing accelerator (F), or a curing catalyst (G).

Description

  The present invention relates to a curable epoxy resin composition, a cured product obtained by curing the curable epoxy resin composition, a curable resin composition for light reflection comprising the curable epoxy resin composition, and an optical semiconductor element. The present invention relates to an optical semiconductor device including at least a reflector made of the cured product.

  In recent years, in various indoor or outdoor display boards, image reading light sources, traffic signals, large display units, etc., light emitting devices using an optical semiconductor element (LED element) as a light source have been increasingly adopted. Such a light emitting device generally has an optical semiconductor element and a transparent resin that protects the periphery of the optical semiconductor element, and further improves the efficiency of extracting light emitted from the optical semiconductor element. A light emitting device having a reflector (reflecting material) for reflecting light is widely used.

  The reflector is required to have high light reflectivity and to continuously exhibit such high light reflectivity. Conventionally, as a constituent material of the reflector, a resin composition in which an inorganic filler or the like is dispersed in a polyamide resin (polyphthalamide resin) having a terephthalic acid unit as an essential constituent unit is known (Patent Literature). 1-3).

  Moreover, as a constituent material of the reflector, in addition, a thermosetting resin composition for light reflection containing a thermosetting resin containing an epoxy resin and an inorganic oxide having a refractive index of 1.6 to 3.0 at a specific ratio. A thing is known (refer patent document 4). Furthermore, it contains a thermosetting resin component and one or more filler components, and the difference between the refractive index of the entire thermosetting resin component and the refractive index of each filler component, and the volume ratio of each filler component A light-reflective thermosetting resin composition in which the calculated parameters are controlled within a specific range is known (see Patent Document 5).

JP 2000-204244 A JP 2004-75994 A JP 2006-257314 A JP 2010-235753 A JP 2010-235756 A

  However, the reflector made of the above-described polyamide resin described in Patent Documents 1 to 3, particularly in a light-emitting device using a high-output blue light semiconductor or white light semiconductor as a light source, is caused by light or heat emitted from the optical semiconductor element over time. There was a problem that it deteriorated due to yellowing or the like and sufficient light reflectivity could not be maintained. Further, with the adoption of lead-free solder, the heating temperature in the reflow process (solder reflow process) during the manufacture of the light emitting device tends to be higher. There was also a problem that the light reflectivity was deteriorated.

  Moreover, in the reflector which consists of the hardened | cured material of the thermosetting resin composition for light reflection of patent document 4, 5, trisglycidyl isocyanurate is used as a main component of the said thermosetting resin, and heat resistance is. There is a problem that light reflectivity decreases with time due to heat generated from the optical semiconductor element and heat in the reflow process.

  Further, the reflector is less likely to crack (crack) with respect to heat, light, and various stresses (for example, stress applied by cutting or temperature change) generated from the optical semiconductor element (such characteristics are not observed). It is required to be tough, such as “may be referred to as“ crack resistance ”). This is because if the reflector is cracked, the light reflectivity is lowered (that is, the light extraction efficiency is lowered), and it is difficult to ensure the reliability of the light emitting device.

  For this reason, it is excellent in heat resistance and light resistance, capable of forming a reflector that does not cause deterioration or cracking due to higher output, shorter wavelength light or high temperature, and whose light reflectivity is less likely to deteriorate over time, and At present, a tough material is required.

Accordingly, an object of the present invention is to provide a curable epoxy resin composition that has a high light reflectivity, is excellent in heat resistance and light resistance, is strong, and gives a cured product in which the light reflectivity is less likely to deteriorate over time. There is to do.
Another object of the present invention is to cure the curable epoxy resin composition, have high light reflectivity, excellent heat resistance and light resistance, and toughness, and the light reflectivity over time. It is in providing the hardened | cured material which is hard to fall.
Another object of the present invention is to provide a light-reflective curable resin composition capable of obtaining an optical semiconductor device in which a decrease in luminance of light over time is suppressed.
Another object of the present invention is to provide a highly reliable optical semiconductor device in which the luminance of light is less likely to decrease over time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a curable epoxy resin composition containing an alicyclic epoxy compound, alumina, a specific aliphatic polyglycidyl ether, and a white pigment as essential components. The cured product was found to have high light reflectivity, excellent heat resistance and light resistance, and tough, and the light reflectivity hardly deteriorates over time, and the present invention was completed. The present invention has been completed based on these findings and further research.

  That is, the present invention includes an alicyclic epoxy compound (A), alumina (B), an aliphatic polyglycidyl ether (C) having a viscosity at 25 ° C. of 8000 mPa · s or more, and a white pigment (D). A curable epoxy resin composition is provided.

  Furthermore, the said curable epoxy resin composition containing a hardening | curing agent (E) and a hardening accelerator (F), or a hardening catalyst (G) is provided.

  Furthermore, the said hardening | curing agent (E) provides the said curable epoxy resin composition which is a liquid acid anhydride at 25 degreeC.

  Furthermore, the curable epoxy resin composition is provided wherein the curing catalyst (G) is a cationic polymerization initiator that generates a cationic species by performing ultraviolet irradiation or heat treatment.

  Furthermore, a glycidyl ether-based epoxy compound having no aromatic ring (excluding aliphatic polyglycidyl ether (C)) and / or a polyol compound exhibiting a liquid state at 25 ° C. (however, polyether polyol and aliphatic polyglycidyl ether ( A curable epoxy resin composition as described above comprising (except for C).

  Furthermore, the said curable epoxy resin composition containing a rubber particle is provided.

  Furthermore, the said curable epoxy resin composition whose aliphatic polyglycidyl ether (C) is sorbitol polyglycidyl ether is provided.

  Furthermore, the curable epoxy resin composition is provided in which the glycidyl ether epoxy compound having no aromatic ring is a hydrogenated bisphenol A type epoxy compound.

  Moreover, this invention provides the hardened | cured material formed by hardening | curing the said curable epoxy resin composition.

  Moreover, this invention provides the curable resin composition for light reflections which consists of said curable epoxy resin composition.

  The present invention also provides an optical semiconductor device comprising an optical semiconductor element and a reflector made of a cured product of the light-reflective curable resin composition.

  Since the curable epoxy resin composition of the present invention has the above-described configuration, the cured product obtained by curing the curable epoxy resin composition has high light reflectivity, and is excellent in heat resistance and light resistance. In addition, since it is tough, the light reflectivity is unlikely to deteriorate with time. Therefore, the curable epoxy resin composition of the present invention can be preferably used as a curable resin composition for light reflection for various uses related to optical semiconductor devices, particularly for LED packages. Furthermore, a reflector (reflecting material) made of a cured product of the curable epoxy resin composition (curable resin composition for light reflection) of the present invention can continue to exhibit high light reflectivity for a long period of time. An optical semiconductor device (light emitting device) including at least an element and the reflector can exhibit high reliability as a long-life optical semiconductor device.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the optical semiconductor device which has a reflector which consists of hardened | cured material of the curable epoxy resin composition (curable resin composition for light reflection) of this invention, (a) is a perspective view, (b) is It is sectional drawing.

<Curable epoxy resin composition>
The curable epoxy resin composition of the present invention comprises an alicyclic epoxy compound (A), alumina (B), an aliphatic polyglycidyl ether (C) having a viscosity at 25 ° C. of 8000 mPa · s or more, a white pigment ( D) as an essential component. The curable epoxy resin composition of the present invention preferably further contains a curing agent (E) and a curing accelerator (F) or a curing catalyst (G).

[Alicyclic epoxy compound (A)]
The alicyclic epoxy compound (A) constituting the curable epoxy resin composition of the present invention is a compound having at least an alicyclic (aliphatic ring) structure and an epoxy group in the molecule (in one molecule), ( i) a compound having an epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting the alicyclic ring (sometimes referred to as “alicyclic epoxy group”), or (ii) an epoxy group on the alicyclic ring Is a compound that is directly bonded by a single bond.

  (I) A compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and oxygen atoms constituting an alicyclic ring is arbitrarily selected from known or commonly used compounds. be able to. Among these, the above compound preferably has an epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting a cyclohexane ring, that is, a compound having a cyclohexene oxide group (alicyclic epoxy compound). .

式（Ｉ）中、Ｘは単結合又は連結基（１以上の原子を有する２価の基）を示す。上記連結基としては、例えば、２価の炭化水素基、カルボニル基、エーテル基（エーテル結合）、チオエーテル基（チオエーテル結合）、エステル基（エステル結合）、カーボネート基（カーボネート結合）、アミド基（アミド結合）、及びこれらが複数個連結した基等が挙げられる。 (I) Especially as a compound which has an epoxy group (alicyclic epoxy group) comprised by two adjacent carbon atoms and oxygen atoms which comprise an alicyclic ring, in terms of heat resistance and light resistance, the following formula ( The alicyclic epoxy compound (alicyclic epoxy resin) represented by I) is preferable.

In formula (I), X represents a single bond or a linking group (a divalent group having one or more atoms). Examples of the linking group include divalent hydrocarbon groups, carbonyl groups, ether groups (ether bonds), thioether groups (thioether bonds), ester groups (ester bonds), carbonate groups (carbonate bonds), amide groups (amides). Bond), and a group in which a plurality of these are linked.

Examples of the alicyclic epoxy compound in which X in the formula (I) is a single bond include compounds represented by the following formula. As such an alicyclic epoxy compound, for example, a commercial product such as a trade name “Celoxide 8000” (manufactured by Daicel Corporation) can be used.

  As said bivalent hydrocarbon group, a C1-C18 linear or branched alkylene group, a bivalent alicyclic hydrocarbon group, etc. are mentioned, for example. Examples of the linear or branched alkylene group having 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, 1,3-cyclohexene group. And divalent cycloalkylene groups (including cycloalkylidene groups) such as a silylene group, 1,4-cyclohexylene group, and cyclohexylidene group.

  As the linking group X, a linking group containing an oxygen atom is preferable, and specifically, for example, —CO— (carbonyl group), —O—CO—O— (carbonate group), —COO— ( Ester group), -O- (ether group), -CONH- (amide group), a group in which a plurality of these groups are linked, one or more of these groups and one or more of divalent hydrocarbon groups And a group in which and are linked. Examples of the divalent hydrocarbon group include those exemplified above.

  Typical examples of the alicyclic epoxy compound represented by the above formula (I) include compounds represented by the following formulas (I-1) to (I-10). As these compounds, for example, commercially available products such as trade names “Celoxide 2021P” and “Celoxide 2081” (manufactured by Daicel Corporation) can also be used. In addition, l in the following formula (I-5) and m in (I-7) each represent an integer of 1 to 30. R is an alkylene group having 1 to 8 carbon atoms such as methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, s-butylene group, pentylene group, hexylene group, heptylene group, octylene group, etc. A linear or branched alkylene group is mentioned. Among these, C1-C3 linear or branched alkylene groups, such as a methylene group, ethylene group, a propylene group, an isopropylene group, are preferable. Moreover, n1-n6 in following formula (I-9) and (I-10) show the integer of 1-30, respectively.

式（ＩＩ）中、Ｒ’はｐ価のアルコールからｐ個の−ＯＨを除した基であり、ｐ、ｎは、それぞれ自然数を表す。ｐ価のアルコール［Ｒ’−（ＯＨ）_p］としては、例えば、炭素数１〜１５のアルコール等が挙げられ、より具体的には、２，２−ビス（ヒドロキシメチル）−１−ブタノール等の多価アルコールなどが挙げられる。ｐは１〜６が好ましく、ｎは１〜３０が好ましい。ｐが２以上の場合、それぞれの（ ）内（丸括弧内）の基におけるｎは同一でもよいし、異なっていてもよい。上記化合物としては、具体的には、２，２−ビス（ヒドロキシメチル）−１−ブタノールの１，２−エポキシ−４−（２−オキシラニル）シクロヘキサン付加物、商品名「ＥＨＰＥ３１５０」（（株）ダイセル製）などが挙げられる。 (Ii) Examples of the compound in which the epoxy group is directly bonded to the alicyclic ring with a single bond include compounds represented by the following formula (II).

In the formula (II), R ′ is a group obtained by removing p —OH from a p-valent alcohol, and p and n each represent a natural number. Examples of the p-valent alcohol [R ′-(OH) _p ] include alcohols having 1 to 15 carbon atoms, and more specifically 2,2-bis (hydroxymethyl) -1-butanol and the like. And polyhydric alcohols. p is preferably 1 to 6, and n is preferably 1 to 30. When p is 2 or more, n in each () (in parentheses) may be the same or different. Specifically, as the above compound, 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol, trade name “EHPE3150” (Co., Ltd.) Daicel) and the like.

  An alicyclic epoxy compound (A) can be used individually or in combination of 2 or more types. Among these, as the alicyclic epoxy compound (A), 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate represented by the above formula (I-1), trade name “Celoxide 2021P” Is particularly preferred.

  Although the usage-amount (content) of the alicyclic epoxy compound (A) of this invention is not specifically limited, when the curable epoxy resin composition of this invention contains a hardening | curing agent (E) as an essential component, it is white. 10-90 weight% is preferable with respect to the whole quantity (100 weight%) of the curable epoxy resin composition except a pigment (D), More preferably, it is 20-90 weight%, More preferably, it is 30-85 weight%. . On the other hand, when the curable epoxy resin composition of the present invention contains the curing catalyst (G) as an essential component, the amount (content) of the alicyclic epoxy compound (A) excludes the white pigment (D). 20-95 weight% is preferable with respect to whole quantity of a curable epoxy resin composition (100 weight%), More preferably, it is 30-95 weight%, More preferably, it is 40-92 weight%.

[Alumina (B)]
The alumina (B) in the curable epoxy resin composition of the present invention plays a role of improving the crack resistance of the cured product. The alumina (B) is not particularly limited, and known and commonly used alumina (aluminum oxide) particles can be used. Alumina (B) can be used alone or in combination of two or more.

  The shape of the alumina (B) is not particularly limited, and examples thereof include a spherical shape, a crushed shape, a fibrous shape, a needle shape, a scale shape, and a whisker shape. Among these, from the viewpoint of dispersibility of the alumina particles, a spherical shape is preferable, and a true spherical shape is particularly preferable.

  The average particle diameter (average particle diameter) of alumina (B) is not particularly limited, but is preferably 0.1 to 20 μm, more preferably 0.1 to 10 μm from the viewpoint of crack resistance. The average particle diameter means a particle diameter at an integrated value of 50% in a particle size distribution measured by a laser diffraction / scattering method.

  As the alumina (B), those produced by a known and commonly used production method can be used. Examples of the method for producing alumina (B) include a dry method such as a vapor phase oxidation method and a wet method such as a hydrothermal synthesis method. Among these, from the viewpoint of the dispersibility of the alumina particles, the VMC method (Vaporized Metal Combustion method, for example, see JP-A-2008-174624) is preferable. That is, as the alumina (B) in the curable epoxy resin composition of the present invention, alumina produced by the VMC method is preferable.

  As alumina (B), for example, trade name “AO-802” (manufactured by Admatechs Co., Ltd., average particle size: 0.7 μm, shape: true spherical shape, production method: VMC method), trade name “AO-502” Commercial products such as “manufactured by Admatechs Co., Ltd., average particle diameter: 0.7 μm, shape: true spherical shape, production method: VMC method” can also be used.

  The content (blending amount) of alumina (B) is not particularly limited, but is preferably 0.1 to 3 parts by weight with respect to the total epoxy group-containing compound (100 parts by weight) contained in the curable epoxy resin composition. More preferably, it is 0.1 to 1 part by weight. When the content of alumina (B) is less than 0.1 parts by weight, the crack resistance of the cured product may be lowered. However, when alumina (B) is used as the white pigment (D) described later, the content (total amount) of alumina (B) in the curable epoxy resin composition is preferably in the range described below.

[Aliphatic polyglycidyl ether (C)]
In particular, the aliphatic polyglycidyl ether (C) in the curable epoxy resin composition of the present invention plays a role of improving the crack resistance of the cured product. The aliphatic polyglycidyl ether (C) in the present invention is a compound in which part or all of the hydroxyl groups of the aliphatic polyol are glycidyl etherified. The “aliphatic polyol” refers to a compound in which two or more hydrogen atoms of a chain (straight chain or branched chain) hydrocarbon are substituted with a hydroxyl group (alcoholic hydroxyl group). Although it does not specifically limit as said aliphatic polyol, For example, sorbitol, xylitol, mannitol, etc. are mentioned.

  The aliphatic polyglycidyl ether (C) is an aliphatic polyglycidyl ether having a viscosity at 25 ° C. of 8000 mPa · s or more. The viscosity at 25 ° C. of the aliphatic polyglycidyl ether (C) is preferably, for example, 8000 to 20000 mPa · s. When the aliphatic polyglycidyl ether having a viscosity at 25 ° C. of less than 8000 mPa · s is used instead of the aliphatic polyglycidyl ether (C), the crack resistance of the cured product is lowered. The viscosity of the aliphatic glycidyl ether (C) at 25 ° C. is determined using, for example, a digital viscometer (trade name “DVU-EII type”, manufactured by Tokimec Co., Ltd.), rotor: standard 1 ° 34 ′ × R24. , Temperature: 25 ° C., rotation speed: 0.5 to 10 rpm.

  The aliphatic polyglycidyl ether (C) is not particularly limited as long as it is an aliphatic polyglycidyl ether having a viscosity (25 ° C.) of 8000 mPa · s or more. For example, sorbitol polyglycidyl ether, xylitol polyglycidyl ether, mannitol And polyglycidyl ether. Among these, sorbitol polyglycidyl ether is preferable from the viewpoint of improving crack resistance of the cured product.

  The average number of epoxy groups (average number of epoxy groups) in one molecule of the aliphatic polyglycidyl ether (C) (particularly sorbitol polyglycidyl ether) is not particularly limited, but from the viewpoint of improving crack resistance of the cured product. 3 to 4 are preferable.

  The average number of hydroxyl groups (average number of hydroxyl groups) of one molecule of the aliphatic polyglycidyl ether (C) (particularly sorbitol polyglycidyl ether) is not particularly limited, but from the viewpoint of improving crack resistance, 1 to 2 is preferred.

  The aliphatic polyglycidyl ether (C) is produced by a known and common production method. For example, it can be produced by reacting epichlorohydrin with the above-mentioned aliphatic polyol (for example, sorbitol).

  As the aliphatic polyglycidyl ether (C), for example, a commercially available product such as “ERISYS GE60” (manufactured by CVC Thermoset Specialties, viscosity (25 ° C.): 13000 mPa · s, average number of epoxy groups: about 4) may be used. it can.

  The content (blending amount) of the aliphatic polyglycidyl ether (C) in the curable epoxy resin composition of the present invention is not particularly limited, but the total epoxy group-containing compound (100% by weight) contained in the curable epoxy resin composition ) To 10 to 30% by weight, and more preferably 10 to 20% by weight. If the content of the aliphatic polyglycidyl ether (C) is less than 10% by weight, the crack resistance may be lowered.

[White pigment (D)]
The white pigment (D) in the curable epoxy resin composition of the present invention plays a role of exhibiting high light reflectivity especially for a cured product obtained by curing the curable epoxy resin composition. As the white pigment (D), known or conventional white pigments can be used, and are not particularly limited. For example, glass, clay, mica, talc, kaolinite (kaolin), halloysite, zeolite, acidic clay, active Inorganic white pigments such as clay, boehmite, pseudoboehmite, inorganic oxides, metal salts such as alkaline earth metal salts; styrene resins, benzoguanamine resins, urea-formalin resins, melamine-formalin resins, amide resins, etc. Organic white pigments such as resin pigments (plastic pigments); hollow particles having a hollow structure (balloon structure), and the like. These white pigments can be used alone or in combination of two or more. In addition, the above-mentioned alumina (B) can also be used as the white pigment (D) (for example, the white pigment (D) and the alumina (B) may be the same).

  Examples of the inorganic oxide include aluminum oxide (alumina), magnesium oxide, antimony oxide, titanium oxide (rutile type titanium oxide, anatase type titanium oxide, brookite type titanium oxide), zirconium oxide, zinc oxide, silicon oxide (dioxide dioxide). Silicon). Examples of the alkaline earth metal salt include magnesium carbonate, calcium carbonate, barium carbonate, magnesium silicate, calcium silicate, magnesium hydroxide, magnesium phosphate, magnesium hydrogen phosphate, magnesium sulfate, calcium sulfate, and sulfuric acid. Examples include barium. Examples of the metal salt other than the alkaline earth metal salt include aluminum silicate, aluminum hydroxide, and zinc sulfide.

  Although it does not specifically limit as said hollow particle, For example, metal oxides, such as inorganic glass (for example, sodium silicate glass, aluminum silicate glass, sodium borosilicate glass, quartz, etc.), silica, alumina, calcium carbonate, barium carbonate, Inorganic hollow particles composed of inorganic materials such as nickel carbonate and calcium silicate (including natural products such as Shirasu Balloon); styrene resins, acrylic resins, silicone resins, acrylic-styrene resins, vinyl chloride -Based resins, vinylidene chloride-based resins, amide-based resins, urethane-based resins, phenol-based resins, styrene-conjugated diene-based resins, acrylic-conjugated diene-based resins, olefin-based polymers (including cross-linked products of these polymers), etc. Organic hollow particles composed of organic materials; hybrids of inorganic and organic materials Inorganic constituted by charges - organic hollow particles. In addition, the said hollow particle may be comprised from the single material, and may be comprised from 2 or more types of materials. In addition, the hollow portion of the hollow particles (the space inside the hollow particles) may be in a vacuum state or may be filled with a medium. However, particularly from the viewpoint of improving the reflectance, the refractive index is low. Hollow particles filled with a medium (for example, an inert gas such as nitrogen or argon or air) are preferred.

  The white pigment (D) is subjected to a known or conventional surface treatment (for example, a surface treatment with a surface treatment agent such as a metal oxide, a silane coupling agent, a titanium coupling agent, an organic acid, a polyol, or silicone). It may be what was done. By performing such a surface treatment, there are cases where compatibility and dispersibility with other components in the curable epoxy resin composition can be improved.

  Among them, the white pigment (D) is preferably an inorganic oxide or an inorganic hollow particle from the viewpoint of availability, heat resistance, and light resistance, and more preferably aluminum oxide, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, One or more white pigments selected from the group consisting of silicon oxide and inorganic hollow particles. In particular, the white pigment (D) is preferably titanium oxide because it has a higher refractive index.

  The shape of the white pigment (D) is not particularly limited, and examples thereof include a spherical shape, a crushed shape, a fiber shape, a needle shape, a scale shape, and a whisker shape. Among these, from the viewpoint of dispersibility of the white pigment (D), a spherical white pigment is preferable, and a true spherical white pigment (for example, a spherical white pigment having an aspect ratio of 1.2 or less) is preferable.

  Although the center particle diameter of a white pigment (D) is not specifically limited, 0.1-50 micrometers is preferable from a viewpoint of the light reflectivity improvement of hardened | cured material. In particular, when an inorganic oxide is used as the white pigment (D), the center particle diameter of the inorganic oxide is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.1 to 30 μm, and still more preferably. It is 0.1-20 micrometers, Most preferably, it is 0.1-10 micrometers, Most preferably, it is 0.1-5 micrometers. On the other hand, when hollow particles (particularly inorganic hollow particles) are used as the white pigment (D), the center particle size of the hollow particles is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.1 to 0.1 μm. 30 μm. In addition, the said center particle size means the particle size (median diameter) in the integrated value 50% in the particle size distribution measured by the laser diffraction / scattering method.

  The content (blending amount) of the white pigment (D) in the curable epoxy resin composition of the present invention is not particularly limited, but is 80 with respect to 100 parts by weight of the total epoxy group-containing compound contained in the curable epoxy resin composition. -500 weight part is preferable, More preferably, it is 90-400 weight part, More preferably, it is 100-380 weight part. When content of a white pigment (D) is less than 80 weight part, there exists a tendency for the light reflectivity of hardened | cured material to fall. On the other hand, when the content of the white pigment (D) exceeds 500 parts by weight, the toughness of the cured product tends to decrease. In addition, when alumina (B) is used as the white pigment (D), although not particularly limited, the total amount of alumina (B) in the curable resin composition is within the above range (preferably 80 to 500 parts by weight, more preferably 90 parts. ˜400 parts by weight, more preferably 100 to 380 parts by weight). On the other hand, when a white pigment other than alumina (B) is used as the white pigment (D), the content of the white pigment (D) in the curable resin composition is not particularly limited, but is preferably 80 to 500 parts by weight, More preferably, it is 90-400 weight part, More preferably, it is 100-380 weight part.

  The white pigment (D) can be produced by a known or conventional production method. Moreover, as a white pigment (D), a commercial item can also be used, for example, brand name "SR-1", "R-42", "R-45M", "R-650", "R-32". ”,“ R-5N ”,“ GTR-100 ”,“ R-62N ”,“ R-7E ”,“ R-44 ”,“ R-3L ”,“ R-11P ”,“ R-21 ”, "R-25", "TCR-52", "R-310", "D-918", "FTR-700" (manufactured by Sakai Chemical Industry Co., Ltd.), trade name "Taipeke CR-50", "CR-50-2", "CR-60", "CR-60-2", "CR-63", "CR-80", "CR-90", "CR-90-2", "CR -93 "," CR-95 "," CR-97 "(manufactured by Ishihara Sangyo Co., Ltd.), trade names" JR-301 "," JR-403 "," JR-405 " “JR-600A”, “JR-605”, “JR-600E”, “JR-603”, “JR-805”, “JR-806”, “JR-701”, “JRNC”, “JR-800” ", JR" (manufactured by Teika Co., Ltd.), trade names "TR-600", "TR-700", "TR-750", "TR-840", "TR-900" (above, Fuji Manufactured by Titanium Industry Co., Ltd.), trade names “KR-310”, “KR-380”, “KR-380N”, “ST-410WB”, “ST-455”, “ST-455WB”, “ST-457SA” ”,“ ST-457EC ”,“ ST-485SA15 ”,“ ST-486SA ”,“ ST-495M ”(above, manufactured by Titanium Industry Co., Ltd.), etc .; trade name“ A-110 ”, "TCA-123E", "A-1 “0”, “A-197”, “SA-1”, “SA-1L”, “SSP series”, “CSB series” (above, manufactured by Sakai Chemical Industry Co., Ltd.), trade name “JA-1”, “JA-C”, “JA-3” (manufactured by Teika Co., Ltd.), trade names “KA-10”, “KA-15”, “KA-20”, “STT-65C-S”, “ Anatase type titanium oxide such as “STT-30EHJ” (manufactured by Titanium Industry Co., Ltd.) can be used.

  The curable epoxy resin composition of the present invention contains at least the alicyclic epoxy compound (A), alumina (B), aliphatic polyglycidyl ether (C), and white pigment (D). As a preferable aspect of the curable epoxy resin composition of the present invention, an alicyclic epoxy compound (A), alumina (B), aliphatic polyglycidyl ether (C), white pigment (D), curing agent (E), And 6 components of curing accelerator (F) as essential components, or alicyclic epoxy compound (A), alumina (B), aliphatic polyglycidyl ether (C), white pigment (D), and curing The aspect etc. which use 5 components of a catalyst (G) as an essential component are mentioned.

[Curing agent (E)]
The curing agent (E) is a compound having a function of curing a compound having an epoxy group. As a hardening | curing agent (E), a well-known and usual hardening | curing agent can be used as a hardening | curing agent for epoxy resins. As the curing agent (E), an acid anhydride which is liquid at 25 ° C. is preferable, and examples thereof include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenyl succinic anhydride, and methylendomethylenetetrahydrophthalic anhydride. Can be mentioned. In addition, solid acid anhydrides (for example, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylcyclohexene dicarboxylic acid anhydride, etc.) that are solid at normal temperature (25 ° C) are liquid acids at normal temperature (25 ° C). It can also be used as a curing agent (E) by dissolving in an anhydride to form a liquid mixture. A hardening | curing agent (E) can be used individually or in combination of 2 or more types.

  In the present invention, as the curing agent (E), commercially available products such as “Rikacid MH-700” (manufactured by Shin Nippon Rika Co., Ltd.) and “HN-5500” (manufactured by Hitachi Chemical Co., Ltd.). Can also be used.

  Although content (blending amount) of a hardening | curing agent (E) is not specifically limited, 50-200 weight part is preferable with respect to all the epoxy group containing compounds (100 weight part) contained in a curable epoxy resin composition, More preferably, it is 50-145 weight part, More preferably, it is 100-145 weight part. More specifically, it is preferably used at a ratio of 0.5 to 1.5 equivalents per 1 equivalent of epoxy groups in all the compounds having epoxy groups contained in the curable epoxy resin composition. When content of a hardening | curing agent (E) is less than 50 weight part, hardening will become inadequate and there exists a tendency for the toughness of hardened | cured material to fall. On the other hand, when content of a hardening | curing agent (E) exceeds 200 weight part, hardened | cured material may color and hue may deteriorate.

[Curing accelerator (F)]
A hardening accelerator (F) is a compound which has a function which accelerates | stimulates a cure rate, when the compound which has an epoxy group hardens | cures with a hardening | curing agent (E). As the curing accelerator (F), a well-known and commonly used curing accelerator can be used, and is not particularly limited. For example, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) and its Salts (eg, phenol salts, octylates, p-toluenesulfonates, formates, tetraphenylborate salts); 1,5-diazabicyclo [4.3.0] nonene-5 (DBN), and salts thereof ( For example, phosphonium salt, sulfonium salt, quaternary ammonium salt, iodonium salt); tertiary amine such as benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, N, N-dimethylcyclohexylamine; Imidazoles such as ethyl-4-methylimidazole and 1-cyanoethyl-2-ethyl-4-methylimidazole; Le, phosphines such as triphenylphosphine; tetraphenylphosphonium tetra (p- tolyl) phosphonium compounds such as borate, tin octylate, organic metal salts such as zinc octylate; metal chelate and the like. A hardening accelerator (F) can be used individually or in mixture of 2 or more types.

  In the present invention, as the curing accelerator (F), trade names “U-CAT SA 506”, “U-CAT SA 102”, “U-CAT 5003”, “U-CAT 18X”, “12XD (developed product) ”” (San Apro Co., Ltd.), trade names “TPP-K”, “TPP-MK” (Hokuko Chemical Co., Ltd.), trade names “PX-4ET” (Nippon Chemical Industry Co., Ltd.) ))) And other commercial products can also be used.

  Although content (blending amount) of a hardening accelerator (F) is not specifically limited, 0.05-5 weight part with respect to all the epoxy-group containing compounds (100 weight part) contained in a curable epoxy resin composition. More preferably, it is 0.1-3 weight part, More preferably, it is 0.2-3 weight part, Most preferably, it is 0.25-2.5 weight part. When content of a hardening accelerator (F) is less than 0.05 weight part, the hardening promotion effect may become inadequate. On the other hand, when content of a hardening accelerator (F) exceeds 5 weight part, hardened | cured material may color and a hue may deteriorate.

[Curing catalyst (G)]
The curing catalyst (G) in the present invention has a function of initiating polymerization of a compound having an epoxy group in the curable epoxy resin composition. As the curing catalyst (G), a cationic polymerization initiator that generates cationic species by performing ultraviolet irradiation or heat treatment to initiate polymerization of the alicyclic epoxy compound (A) is preferable. A curing catalyst (G) can be used individually or in combination of 2 or more types.

  Examples of the cationic polymerization initiator that generates cationic species upon irradiation with ultraviolet rays include hexafluoroantimonate salts, pentafluorohydroxyantimonate salts, hexafluorophosphate salts, hexafluoroarsenate salts, and the like. These cationic polymerization initiators (cationic catalysts) can be used alone or in combination of two or more. Examples of such cationic polymerization initiators include trade names “UVACURE 1590” (manufactured by Daicel Cytec Co., Ltd.), trade names “CD-1010”, “CD-1011”, “CD-1012” (above, the United States). Commercial products such as Sartomer Co., Ltd., trade name “Irgacure 264” (manufactured by Ciba Japan Co., Ltd.), and trade name “CIT-1682” (manufactured by Nippon Soda Co., Ltd.) can be preferably used.

  Examples of the cationic polymerization initiator that generates a cationic species by heat treatment include aryldiazonium salts, aryliodonium salts, arylsulfonium salts, and allene-ion complexes. Examples of such cationic polymerization initiators include trade names “PP-33”, “CP-66”, “CP-77” (manufactured by ADEKA Corporation), trade names “FC-509” (3M). (Trade name) “UVE1014” (manufactured by GE Corporation), trade names “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L”, “Sun-Aid SI-110L” ”,“ Sun-Aid SI-150L ”(manufactured by Sanshin Chemical Industry Co., Ltd.), and trade name“ CG-24-61 ”(manufactured by Ciba Japan Co., Ltd.) can be preferably used. Furthermore, a chelate compound of a metal such as aluminum or titanium and a acetoacetate or diketone compound and a silanol such as triphenylsilanol, or a chelate compound of a metal such as aluminum or titanium and acetoacetate or diketone and bisphenol S Compounds with phenols such as can also be used as the cationic polymerization initiator.

  The content (blending amount) of the curing catalyst (G) is not particularly limited, but is 0.01 to 15 parts by weight with respect to the total epoxy group-containing compound (100 parts by weight) contained in the curable epoxy resin composition. More preferably, it is 0.01-12 weight part, More preferably, it is 0.05-10 weight part, Especially preferably, it is 0.1-10 weight part. By using the curing catalyst (G) within the above range, it is easy to obtain a cured product having excellent heat resistance and light resistance.

[Rubber particles]
The curable epoxy resin composition of the present invention may further contain rubber particles. Examples of the rubber particles include rubber particles such as particulate NBR (acrylonitrile-butadiene rubber), reactive terminal carboxyl group NBR (CTBN), metal-free NBR, particulate SBR (styrene-butadiene rubber). The rubber particles are preferably rubber particles having a multilayer structure (core-shell structure) composed of a core portion having rubber elasticity and at least one shell layer covering the core portion. The rubber particles are particularly composed of a polymer (polymer) having (meth) acrylic acid ester as an essential monomer component, and react with a compound having an epoxy group such as an alicyclic epoxy compound (A) on the surface. Rubber particles having a hydroxyl group and / or a carboxyl group (either one or both of a hydroxyl group and a carboxyl group) as the functional group to be obtained are preferred. If there are no hydroxyl groups and / or carboxyl groups on the surface of the rubber particles, the cured product may easily crack.

  The polymer constituting the core portion having rubber elasticity in the rubber particles is not particularly limited, but (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate are used. The essential monomer component is preferred. The polymer constituting the core portion having rubber elasticity is, for example, aromatic vinyl such as styrene and α-methylstyrene, nitrile such as acrylonitrile and methacrylonitrile, conjugated diene such as butadiene and isoprene, ethylene, propylene, Isobutene or the like may be contained as a monomer component.

  Especially, the polymer which comprises the said core part which has the rubber elasticity contains 1 type, or 2 or more types selected from the group which consists of aromatic vinyl, a nitrile, and a conjugated diene with a (meth) acrylic acid ester as a monomer component. It is preferable to include it in combination. That is, as the polymer constituting the core part, for example, (meth) acrylic acid ester / aromatic vinyl, (meth) acrylic acid ester / conjugated diene and other binary copolymers; (meth) acrylic acid ester / aromatic And terpolymers such as group vinyl / conjugated dienes. The polymer constituting the core part may contain silicone such as polydimethylsiloxane and polyphenylmethylsiloxane, polyurethane, and the like.

  The polymer constituting the core part includes divinylbenzene, allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diallyl maleate, triallyl cyanurate, diallyl phthalate, butylene glycol diacrylate as other monomer components. A reactive crosslinking monomer having two or more reactive functional groups may be contained in one corresponding monomer (one molecule).

  The core part of the rubber particles is, in particular, a core part composed of a (meth) acrylate / aromatic vinyl binary copolymer (particularly butyl acrylate / styrene) from the viewpoint of heat resistance. Is preferred.

  The core part of the rubber particles can be produced by a commonly used method. For example, it can be produced by a method of polymerizing the monomer by an emulsion polymerization method. In the emulsion polymerization method, the whole amount of the monomer may be charged at once and may be polymerized, or after polymerizing a part of the monomer, the remainder may be added continuously or intermittently to polymerize, Furthermore, a polymerization method using seed particles may be used.

  The polymer constituting the shell layer of the rubber particles is preferably a polymer different from the polymer constituting the core portion. In addition, as described above, the shell layer preferably has a hydroxyl group and / or a carboxyl group as a functional group capable of reacting with a compound having an epoxy group such as the alicyclic epoxy compound (A). Thereby, especially with respect to the hardened | cured material which can improve adhesiveness in an interface with an alicyclic epoxy compound (A), and hardened the curable epoxy resin composition containing the rubber particle which has this shell layer. , Excellent crack resistance can be exhibited. Moreover, the fall of the glass transition temperature of hardened | cured material can also be prevented.

  The polymer constituting the shell layer preferably contains (meth) acrylic acid ester such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate as an essential monomer component. For example, when butyl acrylate is used as the (meth) acrylic acid ester in the core part, (meth) acrylic acid esters other than butyl acrylate (for example, (meth) acrylic) as the monomer component of the polymer constituting the shell layer It is preferable to use methyl acid, ethyl (meth) acrylate, butyl methacrylate and the like. Examples of the monomer component that may be contained in addition to the (meth) acrylic acid ester include aromatic vinyl such as styrene and α-methylstyrene, and nitrile such as acrylonitrile and methacrylonitrile. In the rubber particles, as a monomer component constituting the shell layer, it is preferable to contain the monomer alone or in combination of two or more together with (meth) acrylic acid ester, in particular, at least from the viewpoint of heat resistance. It is preferable that aromatic vinyl is included.

  Further, the polymer constituting the shell layer forms a hydroxyl group and / or a carboxyl group as a functional group capable of reacting with a compound having an epoxy group such as an alicyclic epoxy compound (A) as a monomer component. , Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, α, β-unsaturated acids such as (meth) acrylic acid, α, β-unsaturated acid anhydrides such as maleic anhydride, etc. It is preferable to contain a monomer corresponding to.

  It is preferable that the polymer which comprises the shell layer in the said rubber particle contains 1 type, or 2 or more types selected from the said monomer in combination with (meth) acrylic acid ester as a monomer component. That is, the shell layer is formed of, for example, a ternary copolymer such as (meth) acrylic acid ester / aromatic vinyl / hydroxyalkyl (meth) acrylate, (meth) acrylic acid ester / aromatic vinyl / α, β-unsaturated acid. A shell layer composed of a polymer or the like is preferable.

  Further, the polymer constituting the shell layer includes, as the other monomer components, divinylbenzene, allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diallyl maleate, trimethyl, as well as the above-described monomer. A reactive crosslinking monomer having two or more reactive functional groups may be contained in one monomer (one molecule) corresponding to allyl cyanurate, diallyl phthalate, butylene glycol diacrylate and the like.

  The rubber particles (rubber particles having a core-shell structure) can be obtained by covering the core portion with a shell layer. Examples of the method of coating the core part with a shell layer include a method of coating the surface of the core part having rubber elasticity obtained by the above method by applying a copolymer constituting the shell layer, and the above method Examples thereof include a graft polymerization method in which the core portion having rubber elasticity obtained by the above is used as a trunk component, and each component constituting the shell layer is used as a branch component.

  The average particle diameter of the rubber particles is not particularly limited, but is preferably 10 to 500 nm, and more preferably 20 to 400 nm. The maximum particle size of the rubber particles is not particularly limited, but is preferably 50 to 1000 nm, more preferably 100 to 800 nm. If the average particle diameter exceeds 500 nm or the maximum particle diameter exceeds 1000 nm, the dispersibility of the rubber particles in the cured product may be reduced, and crack resistance may be reduced. On the other hand, if the average particle size is less than 10 nm or the maximum particle size is less than 50 nm, the effect of improving the crack resistance of the cured product may be difficult to obtain.

  The content (blending amount) of the rubber particles in the curable epoxy resin composition of the present invention is not particularly limited, but the total amount (100 parts by weight) of the compound having an epoxy group contained in the curable epoxy resin composition. On the other hand, 0.5-30 weight part is preferable, More preferably, it is 1-20 weight part. When the content of the rubber particles is less than 0.5 parts by weight, the crack resistance of the cured product tends to decrease. On the other hand, when the content of the rubber particles exceeds 30 parts by weight, the heat resistance of the cured product tends to decrease.

  Furthermore, the curable epoxy resin composition of the present invention comprises a glycidyl ether type epoxy compound having an aromatic ring such as a bisphenol A type epoxy compound or a bisphenol F type epoxy compound; a hydrogenated bisphenol A type epoxy compound, an aliphatic glycidyl type epoxy compound. Glycidyl ether epoxy compounds having no aromatic ring (excluding aliphatic polyglycidyl ether (C)); glycidyl ester epoxy compounds; glycidyl amine epoxy compounds; polyol compounds; oxetane compounds; vinyl ether compounds, etc. You may do it.

  Further, the curable epoxy resin composition of the present invention may be an epoxy compound that is solid at ordinary temperature (25 ° C.), as long as it is liquid after compounding. Examples of the epoxy compound that is solid at room temperature (25 ° C.) include solid bisphenol-type epoxy compounds, novolac-type epoxy compounds, and glycidyl esters. These epoxy compounds can be used alone or in combination of two or more.

  Among them, the curable epoxy resin composition of the present invention includes a glycidyl ether epoxy compound having no aromatic ring (in addition to the above curing agent (E), curing accelerator (F), and curing catalyst (G)). High temperature resistance is impaired if it contains a polyol compound (excluding polyether polyol and aliphatic polyglycidyl ether (C)) that is liquid at 25 ° C. and / or an aliphatic polyglycidyl ether (C)) It is preferable in that it can improve crack resistance, and particularly including a glycidyl ether epoxy compound having no aromatic ring can improve crack resistance without impairing high heat resistance and light resistance. This is preferable.

[Glycidyl ether epoxy compound having no aromatic ring]
The glycidyl ether epoxy compound having no aromatic ring in the present invention includes an aliphatic glycidyl ether epoxy compound and a compound obtained by hydrogenating an aromatic glycidyl ether epoxy compound. However, the above-mentioned aliphatic polyglycidyl ether (C) is not included in the glycidyl ether-based epoxy compound having no aromatic ring. Examples of the glycidyl ether-based epoxy compound having no aromatic ring include, for example, trade names “EPICLON 703”, “EPICLON 707”, “EPICLON 720”, “EPICLON 725” (manufactured by DIC Corporation), and trade names “YH-300”. "YH-315", "YH-324", "PG-202", "PG-207", "Santoto ST-3000" (manufactured by Nippon Steel Chemical Co., Ltd.), trade name "Rikaresin DME- "100", "Rikaresin HBE-100" (manufactured by Shin Nippon Rika Co., Ltd.), trade names "Denacol EX-212", "Denacol EX-321" (manufactured by Nagase ChemteX Corporation), trade names Commercially available products such as “YX8000” and “YX8034” (manufactured by Mitsubishi Chemical Corporation) can be preferably used. In addition, the glycidyl ether type epoxy compound which does not have an aromatic ring can be used individually or in combination of 2 or more types.

  The content (blending amount) of the glycidyl ether epoxy compound having no aromatic ring is not particularly limited, but is preferably 10 to 50 parts by weight with respect to 100 parts by weight of the alicyclic epoxy compound (A). Preferably it is 10-30 weight part.

[Polyol compound presenting liquid at 25 ° C.]
The polyol compound exhibiting a liquid state at 25 ° C. in the present invention includes polyol compounds other than polyether polyol, for example, polyester polyol and polycarbonate polyol. However, the above-mentioned aliphatic polyglycidyl ether (C) is not included in the polyol compound exhibiting a liquid state at 25 ° C. In addition, the polyol compound which exhibits liquid state at 25 degreeC can be used individually or in combination of 2 or more types.

  Examples of the polyester polyol include, for example, trade names "Placcel 205", "Placcel 205H", "Placcel 205U", "Placcel 205BA", "Placcel 208", "Placcel 210", "Placcel 210CP", "Placcel 210BA", “Plaxel 212”, “Plaxel 212CP”, “Plaxel 220”, “Plaxel 220CPB”, “Plaxel 220NP1”, “Plaxel 220BA”, “Plaxel 220ED”, “Plaxel 220EB”, “Plaxel 220EC”, “Plaxel 230”, “Plaxel 230CP”, “Plaxel 240”, “Plaxel 240CP”, “Plaxel 210N”, “Plaxel 220N”, “Plaxel L205AL”, “Plaxel L208A” ”,“ Plaxel L212AL ”,“ Plaxel L220AL ”,“ Plaxel L230AL ”,“ Plaxel 305 ”,“ Plaxel 308 ”,“ Plaxel 312 ”,“ Plaxel L312AL ”,“ Plaxel 320 ”,“ Plaxel L320AL ”,“ Plaxel L330AL ” , “Plaxel 410”, “Plaxel 410D”, “Plaxel 610”, “Plaxel P3403”, “Plaxel CDE9P” (above, manufactured by Daicel Corporation) can be used.

  Examples of the polycarbonate polyol include trade names “Placcel CD205PL”, “Plaxel CD205HL”, “Plaxel CD210PL”, “Plaxel CD210HL”, “Plaxel CD220PL”, “Plaxel CD220HL” (manufactured by Daicel Corporation) Names “UH-CARB50”, “UH-CARB100”, “UH-CARB300”, “UH-CARB90 (1/3)”, “UH-CARB90 (1/1)”, “UC-CARB100” (above, Ube) Products manufactured by Kosan Co., Ltd.), trade names such as “PCDL T4671”, “PCDL T4672”, “PCDL T5650J”, “PCDL T5651”, “PCDL T5652” (above, manufactured by Asahi Kasei Chemicals) be able to.

  The content (blending amount) of the polyol compound that is liquid at 25 ° C. is not particularly limited, but is preferably 5 to 50 parts by weight, more preferably 100 parts by weight of the alicyclic epoxy compound (A). 10 to 40 parts by weight.

  In addition to the above, the curable epoxy resin composition of the present invention can use various additives within a range that does not impair the effects of the present invention.

  For example, when a compound having a hydroxyl group such as ethylene glycol, diethylene glycol, propylene glycol, or glycerin is used as the additive, the reaction can be allowed to proceed slowly. In addition, silicone and fluorine antifoaming agents, leveling agents, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, surfactants, filling, etc. Conventional additives such as an agent, a flame retardant, a colorant, an antioxidant, an ultraviolet absorber, an ion adsorbent, a pigment, and a release agent can be used. The content (blending amount) of these additives is preferably 5% by weight or less based on the total amount (100% by weight) of the curable epoxy resin composition.

  The manufacturing method of the curable epoxy resin composition of this invention is not specifically limited, A well-known and usual method can be used. Specifically, for example, a predetermined amount of alicyclic epoxy compound (A), alumina (B), aliphatic polyglycidyl ether (C), white pigment (D), curing agent (E), curing accelerator (F Or a predetermined amount of alicyclic epoxy compound (A), alumina (B), aliphatic polyglycidyl ether (C), white pigment (D), curing catalyst (G), and optional additives. And a method of stirring and mixing with various mixers such as a dissolver and a homogenizer, a kneader, a roll, a bead mill, a self-revolving stirrer and the like. Further, after stirring and mixing, defoaming may be performed under vacuum.

  Although not particularly limited, when the curable epoxy resin composition of the present invention contains the rubber particles, the rubber particles are preliminarily dispersed in the alicyclic epoxy compound (A) (“rubber particle dispersed epoxy compound”). It is preferable to mix | blend in the state of "it may be called". That is, when the curable epoxy resin composition of the present invention contains the rubber particles, the rubber particle-dispersed epoxy compound, alumina (B), aliphatic polyglycidyl ether (C), and white pigment (D) It is preferable to prepare by mixing other components as necessary. By preparing the curable epoxy resin composition of the present invention by such a method, in particular, the dispersibility of the rubber particles in the curable resin composition can be improved. However, the blending method of the rubber particles is not limited to the above, and may be blended alone.

(Rubber particle dispersed epoxy compound)
The rubber particle-dispersed epoxy compound is obtained by dispersing the rubber particles in the alicyclic epoxy compound (A). The alicyclic epoxy compound (A) in the rubber particle-dispersed epoxy compound may be the total amount of the alicyclic epoxy compound (A) constituting the curable epoxy resin composition, or may be a partial amount. There may be. Similarly, the rubber particles in the rubber particle-dispersed epoxy compound may be the total amount of rubber particles constituting the curable epoxy resin composition, or may be a partial amount.

  The viscosity of the rubber particle-dispersed epoxy compound is not particularly limited, but the viscosity at 25 ° C. (viscosity (25 ° C.)) is preferably 400 to 50000 mPa · s, and more preferably 500 to 10000 mPa · s. When the viscosity (25 ° C.) of the rubber particle-dispersed epoxy compound exceeds 50000 mPa · s, productivity tends to decrease in both the production of the rubber particle-dispersed epoxy compound and the production of the curable epoxy resin composition.

  The viscosity of the rubber particle-dispersed epoxy compound can be adjusted by using a reactive diluent in combination. As the reactive diluent, for example, an aliphatic polyglycidyl ether having a viscosity at room temperature (25 ° C.) of 200 mPa · s or less can be preferably used. Examples of the aliphatic polyglycidyl ether having a viscosity (25 ° C.) of 200 mPa · s or less include, for example, cyclohexanedimethanol diglycidyl ether, cyclohexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. , Trimethylolpropane triglycidyl ether, polypropylene glycol diglycidyl ether, and the like.

  The amount of the reactive diluent used can be appropriately adjusted and is not particularly limited, but is preferably 30 parts by weight or less with respect to 100 parts by weight of the total amount of the alicyclic epoxy compound (A) and the rubber particles, More preferably, it is 25 parts by weight or less (for example, 5 to 25 parts by weight). If the amount used exceeds 30 parts by weight, it tends to be difficult to obtain desired performance such as crack resistance.

  It does not specifically limit as a manufacturing method of the said rubber particle dispersion | distribution epoxy compound, A well-known and usual method can be used. For example, after the rubber particles are dehydrated and dried to form powder, the rubber particles are mixed and dispersed in the alicyclic epoxy compound (A), or the emulsion of rubber particles and the alicyclic epoxy compound (A) are directly mixed. Subsequent methods such as dehydration can be used.

<Hardened product>
The curable epoxy resin composition of the present invention can be made into a cured product by heating and / or curing by irradiating light such as ultraviolet rays. The heating temperature (curing temperature) and the heating time (curing time) at the time of curing are not particularly limited. For example, conditions for forming a reflector described later can be employed.

  Although the reflectance of the hardened | cured material of the curable epoxy resin composition of this invention is not specifically limited, For example, it is preferable that the reflectance of light with a wavelength of 450 nm is 90% or more, More preferably, it is 90.5% or more. is there. In particular, the reflectance of light at 450 to 800 nm is preferably 90% or more, and more preferably 90.5% or more. In addition, the said reflectance uses the hardened | cured material (thickness: 3 mm) of the curable epoxy resin composition of this invention as a test piece, for example, a spectrophotometer (brand name "spectrophotometer UV-2450", Shimadzu Corporation) (Manufactured by Seisakusho).

  The cured product obtained by curing the curable epoxy resin composition of the present invention has high light reflectivity, is excellent in heat resistance and light resistance, and is tough. For this reason, since the said hardened | cured material does not deteriorate easily and a crack does not produce easily, a reflectance does not fall easily with time. Therefore, the curable epoxy resin composition of the present invention is used for LED packages (components for LED packages, such as reflector materials and housing materials for optical semiconductor devices), adhesive applications for electronic components, and liquid crystal display applications (for example, reflective). Plate), white substrate ink, sealer and the like. Especially, it can use especially preferably as curable resin composition for LED packages (especially curable resin composition for reflectors (reflecting material) in an optical semiconductor device).

<Curable resin composition for light reflection>
The curable epoxy resin composition for light reflection of the present invention comprises the curable epoxy resin composition of the present invention. In the present specification, the “curable resin composition for light reflection” means a curable resin composition capable of forming a cured product having high light reflectivity by curing, specifically, For example, it means a curable resin composition capable of forming a cured product having a reflectance of 80% or more with respect to light having a wavelength of 450 nm. By using the curable resin composition for light reflection of the present invention, for example, light provided with a reflector formed of a cured product having excellent physical properties such as light reflectivity, heat resistance, light resistance, and crack resistance. A semiconductor device can be obtained. Since the reflector is less likely to decrease the reflectivity over time, the optical semiconductor device provided with the reflector is particularly difficult to decrease in light intensity over time even when the optical semiconductor device includes a high-output, high-intensity optical semiconductor element. High reliability can be demonstrated.

<Optical semiconductor device>
The optical semiconductor device of the present invention is an optical semiconductor device comprising at least an optical semiconductor element as a light source and a reflector made of a cured product of the curable epoxy resin composition (curable resin composition for light reflection) of the present invention. . The reflector is a member for reflecting light emitted from the optical semiconductor element in the optical semiconductor device to improve the directivity and luminance of the light and to improve the light extraction efficiency. FIG. 1 is a schematic view showing an example of an optical semiconductor device (an optical semiconductor device of the present invention) having a reflector formed from a cured product of the curable resin composition for light reflection of the present invention, and (a) is a perspective view. FIG. 2B shows a cross-sectional view. In FIG. 1, 1 is a reflector, 2 is a metal wiring, 3 is an optical semiconductor element (LED element), 4 is a bonding wire, 5 is a sealing resin, and 6 is a package resin. The reflector 1 has a shape that surrounds the sealing resin 5 in a ring shape and is inclined so that the diameter of the ring increases upward. In the optical semiconductor device shown in FIG. 1, the light emitted from the optical semiconductor element 3 can be extracted with high efficiency by reflecting the light emitted from the optical semiconductor element 3 on the surface (reflection surface) of the reflector 1.

  As the method for forming the reflector, a known or conventional molding method can be used, and is not particularly limited. For example, transfer molding, compression molding, injection molding, LIM molding (injection molding), dam molding by dispensing, etc. The method is mentioned.

  Specifically, for example, the reflector can be formed by injecting the curable epoxy resin composition of the present invention (a curable resin composition for light reflection) into a predetermined mold and curing by heating. As the heat curing conditions in this case, for example, the heating temperature is 80 to 200 ° C. (more preferably 80 to 190 ° C., more preferably 80 to 180 ° C.), and the heating time is 30 to 600 minutes (more preferably 45 to 540). Minutes, more preferably 60 to 480 minutes), for example, when the heating temperature is increased, the heating time is shortened, and when the heating temperature is decreased, the heating time is lengthened. preferable. When either one or both of the heating temperature and the heating time is below the above range, curing tends to be insufficient. On the other hand, if either one or both of the heating temperature and the heating time exceed the above range, the resin component may be decomposed. Further, the heat curing treatment may be performed in one stage, or may be performed in stages by performing heat treatment in multiple stages.

  In the present invention, among other things, it is possible to prevent foaming due to a rapid curing reaction, relax stress strain due to curing, and improve toughness (crack resistance). It is preferable to cure it. Specifically, for example, when the curing agent (E) is used, the first stage is heated at a temperature of 80 to 150 ° C. (preferably 100 to 140 ° C.) for 30 to 300 minutes (preferably 45 to 270 minutes). In the second stage, it is preferable to cure by heating at a temperature of 100 to 200 ° C. (preferably 110 to 180 ° C.) for 30 to 600 minutes (preferably 45 to 540 minutes). For example, when using a curing catalyst (G), the first stage is heated at a temperature of 30 to 150 ° C. (preferably 40 to 140 ° C.) for 30 to 300 minutes (preferably 45 to 270 minutes). It is preferable to cure by heating at a temperature of 60 to 200 ° C. (preferably 80 to 180 ° C.) for 30 to 600 minutes as a step.

  Since the optical semiconductor device of the present invention has at least a reflector made of a cured product of the curable epoxy resin composition (curable resin composition for light reflection) of the present invention, even when high-luminance light is output. Can emit light stably for a long time. Furthermore, since the reflector made of a cured product of the curable epoxy resin composition (curable resin composition for light reflection) of the present invention has excellent adhesion to the sealing resin (especially epoxy resin) of the optical semiconductor element, it is even more so. Problems such as a decrease in light intensity over time are unlikely to occur. For this reason, the optical semiconductor device of this invention can exhibit high reliability as a long-life optical semiconductor device.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples. In Tables 1 and 2, “-” indicates that the corresponding component was not blended.

Production Example 1
(Manufacture of rubber particles)
In a 1 L polymerization vessel equipped with a reflux condenser, 500 g of ion-exchanged water and 0.68 g of sodium dioctylsulfosuccinate were charged, and the temperature was raised to 80 ° C. while stirring under a nitrogen stream. Here, a monomer mixture consisting of 9.5 g of butyl acrylate, 2.57 g of styrene, and 0.39 g of divinylbenzene corresponding to about 5% by weight of the amount required to form the core portion is collectively collected. After stirring for 20 minutes to emulsify, 9.5 mg of potassium peroxodisulfate is added, stirred for 1 hour to perform the initial seed polymerization, followed by addition of 180.5 mg of potassium peroxodisulfate, Stir for 5 minutes. Here, the remaining amount (about 95% by weight) of butyl acrylate 180.5 g, styrene 48.89 g, divinylbenzene 7.33 g and 0.95 g of sodium dioctyl sulfosuccinate were added to form the core part. The dissolved monomer mixture was continuously added over 2 hours to perform the second seed polymerization, and then aged for 1 hour to obtain a core part.
Next, 60 mg of potassium peroxodisulfate was added and stirred for 5 minutes. To this, a solution obtained by dissolving 0.3 g of sodium dioctylsulfosuccinate in 60 g of methyl methacrylate, 1.5 g of acrylic acid and 0.3 g of allyl methacrylate was added. The monomer mixture was continuously added over 30 minutes to perform seed polymerization. Then, it aged for 1 hour and formed the shell layer which coat | covers a core part.
Next, the mixture was cooled to room temperature (25 ° C.) and filtered through a plastic mesh having an opening of 120 μm to obtain a latex containing rubber particles having a core-shell structure. The obtained latex was frozen at −30 ° C., dehydrated and washed with a suction filter, and then blown and dried at 60 ° C. overnight to obtain rubber particles. The resulting rubber particles had an average particle size of 254 nm and a maximum particle size of 486 nm.

The average particle size and the maximum particle size of the rubber particles are “Nanotrac ^™ ” type nanotrack particle size distribution measuring device (trade name “UPA-EX150”, manufactured by Nikkiso Co., Ltd.) based on the dynamic light scattering method. ) Is used to measure the following sample, and in the obtained particle size distribution curve, the average particle size, which is the particle size when the cumulative curve becomes 50%, is the average particle size, and the frequency (%) of the particle size distribution measurement result is The maximum particle size at the time when it exceeded 0.00% was defined as the maximum particle size. A sample obtained by dispersing 1 part by weight of a rubber particle-dispersed epoxy compound in 20 parts by weight of tetrahydrofuran was used as a sample.

Production Example 2
(Manufacture of rubber particle-dispersed epoxy compounds)
Using 10 parts by weight of the rubber particles obtained in Production Example 1 heated to 60 ° C. under a nitrogen stream, a dissolver (1000 rpm, 60 minutes) was used to prepare Celoxide 2021P (3,4-epoxycyclohexylmethyl (3 , 4-epoxy) cyclohexanecarboxylate (manufactured by Daicel Corporation) and dispersed in 80 parts by weight, and vacuum degassed to obtain a rubber particle-dispersed epoxy compound (viscosity at 25 ° C .: 512 mPa · s).
The viscosity (viscosity at 25 ° C.) of the rubber particle-dispersed epoxy compound obtained in Production Example 2 (10 parts by weight of rubber particles dispersed in 80 parts by weight of Celoxide 2021P (manufactured by Daicel Corporation)) is a digital value. The viscosity was measured using a viscometer (trade name “DVU-EII type”, manufactured by Tokimec Co., Ltd.).

Production Example 3
(Production of curing agent composition containing at least curing agent (hereinafter referred to as “K agent”))
Curing agent (acid anhydride) (manufactured by Shin Nippon Rika Co., Ltd., trade name “Rikacid MH-700”), curing accelerator (manufactured by San Apro Co., Ltd., trade name “U-CAT 18X”), additive (Japanese) According to the compounding prescription (mixing ratio) shown in Tables 1 and 2, Kogyo Pharmaceutical Co., Ltd., ethylene glycol), a self-revolving stirrer (manufactured by Shinky Co., Ltd., trade name “Awatori Netaro AR-250” )) To obtain a K agent.

Examples 1-18, Comparative Examples 1-14
(Manufacture of curable epoxy resin composition)
Alumina (manufactured by Admatechs Co., Ltd., trade name “AO-802”), sorbitol polyglycidyl ether (manufactured by CVC Thermoset Specialties, trade name “ERISYS GE60”), hydrogenated bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation) , Trade name “YX8034”), trimethylolpropane triglycidyl ether (manufactured by Nippon Steel Chemical Co., Ltd., trade name “YH300”), polycarbonate diol (manufactured by Daicel Corporation, trade name “CD220PL (Placcel CD220PL)”) , Polycaprolactone diol (manufactured by Daicel Corporation, trade name “L220AL (Placcel L220AL)”), alicyclic epoxy compound (manufactured by Daicel Corporation, trade name “Celoxide 2021P”, trade name “EHPE3150”), production example 2 The resulting rubber particle-dispersed epoxy compound, trisglycidyl isocyanurate (manufactured by Nissan Chemical Industries, Ltd., trade name “TEPIC-PAS B26”) is shown in Tables 1 and 2 (unit: part by weight). ) Using a self-revolving stirrer (trade name “Awatori Nertaro AR-250”, manufactured by Shinky Co., Ltd.), uniformly mixed (2000 rpm, 5 minutes), defoamed, and epoxy resin ( A mixture) was obtained.
Next, the above-mentioned epoxy resin and white pigment (titanium oxide; manufactured by Sakai Chemical Industry Co., Ltd., trade name “TCR-52”) are shown in Tables 1 and 2 (formulation ratio) (unit: parts by weight). Then, the mixture was uniformly mixed using a dissolver, and kneaded by a roll mill under predetermined conditions (roll pitch: 0.2 mm, rotation speed: 25 Hz, 3 passes). Subsequently, the composition after kneading, the K agent obtained in Production Example 3, and the curing catalyst (manufactured by Sanshin Chemical Industry Co., Ltd., trade name “Sun-Aid SI-100L”) are shown in Tables 1 and 2. According to the blending formulation (blending ratio) shown (unit: parts by weight), the mixture is uniformly mixed using a self-revolving stirrer (manufactured by Shinkey Co., Ltd., trade name “Awatori Nertaro AR-250”) (2000 rpm, 5 minutes) and defoamed to obtain a curable epoxy resin composition.

(Manufacture of cured product)
The curable epoxy resin composition was poured into a mold, placed in an oven (trade name “GPHH-201”, manufactured by ESPEC Corporation), and heated at 120 ° C. for 5 hours to obtain a cured product. .

<Evaluation>
The following evaluation was implemented about the hardened | cured material obtained by the Example and the comparative example.

[Reflectance evaluation]
The cured products obtained in the examples and comparative examples were cut to prepare test pieces having a thickness of 3 mm. Next, using a spectrophotometer (trade name “Spectrophotometer UV-2450”, manufactured by Shimadzu Corporation), the reflectance of each test piece with respect to light having a wavelength of 450 nm was measured (hereinafter referred to as “initial reflectance”). ). The results are shown in the column of “initial reflectance” in Tables 1 and 2.

[Heat resistance test]
The test piece (thickness 3 mm) whose initial reflectance was measured was heated at 120 ° C. for 250 hours, and then the reflectance with respect to light having a wavelength of 450 nm was measured (referred to as “reflectance after heating aging”). And the reflectance maintenance factor (before and after heating aging) was computed by the following formula. The results are shown in the columns of “Reflectance retention rate before and after heat aging” in Tables 1 and 2.
[Reflectance retention rate (before and after heating aging) (%)] = ([Reflectance after heating aging] / [Initial reflectance]) × 100

[Light resistance test]
The test piece (thickness 3 mm) whose initial reflectance was measured was irradiated with ultraviolet light having an intensity of 10 mW / cm ² for 250 hours, and then the reflectance with respect to light having a wavelength of 450 nm was measured (referred to as “reflectance after ultraviolet light aging”). ). And the reflectance retention (before and after ultraviolet ray aging) was computed by the following formula. The results are shown in the column of “Reflectance retention rate before and after UV aging” in Tables 1 and 2.
[Reflectance retention rate (before and after UV aging) (%)] = ([Reflectance after UV aging] / [Initial reflectivity]) × 100

[Evaluation of crack occurrence during cutting (Toughness evaluation)]
Test pieces having a width of 5 mm, a length of 5 mm, and a thickness of 3 mm were prepared by cutting the cured products obtained in the examples and comparative examples. For cutting of the cured product, a micro cutting machine (trade name “BS-300CL”, manufactured by Meiwa Forsys Co., Ltd.) is used. This was observed and confirmed using a digital microscope (trade name “VHX-900”, manufactured by Keyence Corporation). In the column of “Number of cracks during cutting” in Tables 1 and 2, 10 test pieces were prepared per sample, and the number of test pieces in which cracks were confirmed [pieces] (“number of cracks”). Is referred to as an evaluation result. In Tables 1 and 2, the case where the number of test pieces in which cracks were confirmed (number of cracks) was n was shown as “n / 10”.

[Evaluation of crack occurrence during reflow (toughness evaluation)]
Using a reflow furnace (trade name “UNI-5016F”, manufactured by Nippon Antom Co., Ltd.) for the test piece (width 5 mm × length 5 mm × thickness 3 mm) obtained by the above cutting, the maximum is 260 ° C. The reflow treatment was performed at a temperature of 5 seconds and a total reflow time of 90 seconds. Thereafter, whether or not the test piece was cracked by the reflow treatment was observed and confirmed using a digital microscope (trade name “VHX-900”, manufactured by Keyence Corporation). In the column of “Number of cracks during reflow” in Tables 1 and 2, the number of test pieces [number of cracks] in which the occurrence of cracks was confirmed (number of cracks). ) Is shown as an evaluation result. In Tables 1 and 2, the case where the number of test pieces in which cracks were confirmed (number of cracks) was n was shown as “n / 10”.

[Comprehensive evaluation]
The initial reflectivity is 90% or more, the reflectivity retention rate is 90% or more in the heat resistance test, the reflectivity retention rate is 90% or more in the light resistance test, the presence or absence of cracks during cutting (toughness evaluation), In addition, the case where the number of cracks was zero in the evaluation of the presence / absence of cracks during reflow (toughness evaluation) was defined as a comprehensive judgment (good). On the other hand, the thing other than this was made into comprehensive judgment x (defective). The results are shown in the column of “Comprehensive judgment” in Tables 1 and 2.

Abbreviations in Tables 1 and 2 indicate the following.
CEL2021P (Celoxide 2021P): 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, manufactured by Daicel Corporation AO-802: Alumina (average particle size: 0.7 μm, shape: true sphere, production method) : VMC method), manufactured by Admatechs Co., Ltd. ERISYS GE60: sorbitol polyglycidyl ether (viscosity (25 ° C.): 13000 mPa · s), CVC Thermoset Specialties YX8034: hydrogenated bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation YH-300: trimethylolpropane triglycidyl ether (viscosity (25 ° C.): 140 mPa · s), Nippon Steel Chemical Co., Ltd. CD220PL (Placcel CD220PL): polycarbonate diol, Daise Co., Ltd. L220AL (Placcel L220AL): Polycaprolactone diol, manufactured by Daicel Corporation EHPE3150: 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol, Tepic-PAS B26 manufactured by Daicel Corporation, trisglycidyl isocyanurate, white pigment manufactured by Nissan Chemical Industries, Ltd., titanium oxide (trade name “TCR-52”), MH-700 manufactured by Sakai Chemical Industry Co., Ltd. (Licacid MH-) 700): 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 70/30, Shin Nippon Rika Co., Ltd. 18X (U-CAT 18X): Curing accelerator, San Apro Co., Ltd. Ethylene glycol: Wako Jun Yakuhin Industries Co., Ltd. Sun-Aid SI-100L: Arylsulfonium , Sanshin Chemical Industry Co., Ltd.

As shown in Tables 1 and 2, the cured products (Examples) of the curable epoxy resin composition of the present invention have excellent light reflectivity and are free from cracks during cutting and reflow. It was tough. Furthermore, even after heat aging and ultraviolet aging, high light reflectivity was maintained, and heat resistance and light resistance were excellent.
On the other hand, a cured product (comparative example) formed from a curable epoxy resin composition that does not satisfy the provisions of the present invention had a low light reflectivity after heat aging and was inferior in heat resistance. Moreover, the crack was produced at the time of cutting, and it was inferior to toughness.

1: Reflector (a reflector made of a cured product of the curable epoxy resin composition of the present invention)
2: Metal wiring 3: Optical semiconductor element 4: Bonding wire 5: Sealing resin 6: Package resin

Claims (11)

  A curing comprising an alicyclic epoxy compound (A), alumina (B), an aliphatic polyglycidyl ether (C) having a viscosity at 25 ° C. of 8000 mPa · s or more, and a white pigment (D). Epoxy resin composition.   The curable epoxy resin composition according to claim 1, further comprising a curing agent (E) and a curing accelerator (F), or a curing catalyst (G).   The curable epoxy resin composition according to claim 2, wherein the curing agent (E) is a liquid acid anhydride at 25 ° C.   The curable epoxy resin composition according to claim 2 or 3, wherein the curing catalyst (G) is a cationic polymerization initiator that generates cationic species by ultraviolet irradiation or heat treatment.   Furthermore, a glycidyl ether-based epoxy compound having no aromatic ring (excluding aliphatic polyglycidyl ether (C)) and / or a polyol compound exhibiting liquid at 25 ° C. (however, polyether polyol and aliphatic polyglycidyl ether ( The curable epoxy resin composition according to any one of claims 1 to 4, further comprising (except for C).   Furthermore, the curable epoxy resin composition of any one of Claims 1-5 containing a rubber particle.   Aliphatic polyglycidyl ether (C) is sorbitol polyglycidyl ether, The curable epoxy resin composition of any one of Claims 1-6.   The curable epoxy resin composition according to any one of claims 5 to 7, wherein the glycidyl ether-based epoxy compound having no aromatic ring is a hydrogenated bisphenol A type epoxy compound.   Hardened | cured material formed by hardening | curing the curable epoxy resin composition of any one of Claims 1-8.   The curable resin composition for light reflections which consists of a curable epoxy resin composition of any one of Claims 1-8.   An optical semiconductor device comprising: an optical semiconductor element; and a reflector made of a cured product of the curable resin composition for light reflection according to claim 10.

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