JP2009280801A - Resin composition, and optical member using cured product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition whose cured product is excellent in transparency, light resistance, heat resistance, mechanical properties, mounting reliability, reflow resistance, and handleability, and to provide an optical member using the resin composition. <P>SOLUTION: The resin composition comprises: an acrylic resin (A) which is obtained by reacting an unsaturated carboxylic acid with a copolymer obtained by copolymerizing (a) an epoxy group-containing (meth)acrylate, (b) an unsaturated compound having one polymerizable unsaturated bond in the molecule, and (c) a siloxane structure-containing (meth)acrylate, such that the ratio of the equivalent of the epoxy group to the equivalent of the carboxyl group of the unsaturated carboxylic acid is 0.3:1-0.7:1; a curable polymerizable monomer (B) having at least one thermosetting or photocurable unsaturated double bond; a radical polymerization initiator (C); and a hindered amine-based light stabilizer (D). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin composition and an optical member using a cured product thereof.

  Optical member resins are used as materials for optical semiconductor elements such as transparent substrates, lenses, adhesives, optical waveguides and light emitting diodes (LEDs), phototransistors, photodiodes, and solid-state imaging devices.

  Conventionally, acrylic resins that are excellent in transparency and light resistance, such as PMMA, have been generally used as optical member resins. However, PMMA has a problem that its curing shrinkage is large and its heat resistance is insufficient because it is a thermoplastic resin.

  On the other hand, the resin for optical members used in the field of optical / electronic equipment is required to have a mounting process on an electronic substrate and the like, heat resistance and mechanical characteristics under high temperature operation, and epoxy resin is often used. However, in recent years, the use of high-intensity laser light, blue light, and near-ultraviolet light has expanded in the field of optical and electronic equipment, and a resin that is more excellent in transparency, heat resistance, and light resistance than ever is required.

  In general, epoxy resins have high transparency in the visible range, but sufficient transparency cannot be obtained in the ultraviolet to near ultraviolet range. Among them, epoxy resins using alicyclic bisphenol A diglycidyl ether have relatively high transparency, but have problems such as being easily colored by heat and light. On the other hand, Patent Document 1 and Patent Document 2 disclose methods for reducing impurities that are one of the causes of coloring contained in alicyclic bisphenol A diglycidyl ether.

  In recent years, an example of using a silicone resin excellent in transparency and colorability for optical member applications, for example, Patent Document 3 has been disclosed.

JP 2003-171439 A JP 2004-75894 A JP 2004-2810 A

  However, the resin for optical members manufactured by using the impurity reduction method described in Patent Documents 1 and 2 and the like has room for improvement in heat resistance and UV resistance.

  Moreover, about the resin for optical members using the silicone resin of patent document 3, there are concerns that the silicone resin is generally difficult to handle, has a large linear expansion coefficient, and has low adhesiveness.

  Therefore, the present invention provides a resin composition having a high optical transparency of the cured product, excellent light resistance, heat resistance, mechanical properties, mounting reliability, reflow resistance, and handleability, and an optical member using the same. The purpose is to provide.

  The present invention includes (A) (a) an epoxy group-containing (meth) acrylate, (b) an unsaturated compound having one polymerizable unsaturated bond in one molecule, and (c) a siloxane structure-containing (meth) acrylate. Is reacted with the unsaturated carboxylic acid so that the equivalent of the epoxy group and the equivalent of the carboxyl group of the unsaturated carboxylic acid are in a ratio of 0.3: 1 to 0.7: 1. Acrylic resin obtained by heating, (B) a curable polymerization monomer having at least one unsaturated double bond capable of being thermally or photocured, (C) a radical polymerization initiator, and (D) a hindered amine light stability. A resin composition containing an agent is provided.

  According to such a resin composition, the cured product has high optical transparency and is excellent in light resistance, heat resistance, mechanical properties, mounting reliability, reflow resistance, and handleability.

  The reason why such an effect is obtained by the resin composition of the present invention is not necessarily clear, but the inventors consider as follows.

That is, PMMA is generally known as an acrylic resin having high transparency as an optical material, but there is a problem that heat resistance is insufficient because it is a thermoplastic resin having a large cure shrinkage.
On the other hand, heat resistance improves by introducing a functional group by making unsaturated carboxylic acid react with an epoxy-group-containing (meth) acrylic copolymer, and making a crosslinked structure more dense.
In addition, by introducing a siloxane structure into the epoxy group-containing (meth) acrylic copolymer, heat resistance and light resistance are further imparted in optical characteristics, and toughness is imparted in mechanical characteristics, and bending strength is improved.
Furthermore, heat resistance and light resistance are further improved by applying a hindered amine light stabilizer.
On the other hand, when the above acrylic resin is applied to the transparent sealing resin of the surface-mount type LED package, in the high temperature reflow process which is the reflow condition of lead-free solder, peeling occurs at the interface between the transparent resin and the package molded body due to thermal stress. was there.
On the other hand, when the unsaturated carboxylic acid is reacted with the epoxy group, the epoxy group equivalent ratio / the unsaturated carboxylic acid carboxyl group equivalent ratio is set to a ratio of 0.3 to 0.7, and the epoxy group remains. By increasing the adhesion to the package molded body due to chemical interaction and lowering the elasticity, the thermal stress generated during the reflow process is alleviated, and at the interface between the transparent resin and the package molded body in the reflow process. Peeling is suppressed.

  The copolymer has (a) 10 to 65 mol% of an epoxy group-containing (meth) acrylate and (b) one polymerizable unsaturated bond in one molecule, based on all monomer units in the copolymer. A copolymer obtained by copolymerization at a ratio of 20 to 75 mol% of an unsaturated compound and (c) 10 to 65 mol% of a siloxane structure-containing (meth) acrylate is preferable.

  (A) The epoxy group-containing (meth) acrylate is preferably glycidyl (meth) acrylate.

  (C) The siloxane structure-containing (meth) acrylate is preferably a compound represented by the following general formula (1) or (2).

（ｍは０〜１０の整数、Ｒ_１、Ｒ_２、Ｒ_３は各々独立して水素原子、炭素数１〜９のアルキル基、アリール基、トリメチルシロキシ基を表す。ただし、Ｒ_１、Ｒ_２、Ｒ_３のうち少なくとも一つは、トリメチルシロキシ基である。）

(M represents an integer of 0 to 10, R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an aryl group or a trimethylsiloxy group, provided that R ₁ , R ₂ , At least one of R ₃ is a trimethylsiloxy group.)

（ｍは０〜１０の整数、ｎは０〜１５０の整数，Ｒ_４は各々独立して水素原子、炭素数１〜９のアルキル基、アリール基を表す。）

(M represents an integer of 0 to 10, n represents an integer of 0 to 150, and R ₄ each independently represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, or an aryl group.)

  The present invention provides an optical member made of a cured product obtained by curing the resin composition of the present invention.

  According to such an optical member, the optical transparency is high, and the light resistance, heat resistance, and handleability are excellent.

  According to the present invention, it is possible to provide a resin composition having high optical transparency of the cured product and excellent in light resistance, heat resistance, mechanical properties, mounting reliability, reflow resistance, and handleability. Furthermore, according to the present invention, it is possible to provide an optical member that is excellent in heat resistance, light resistance, and handleability, and has improved life and reliability.

It is a schematic cross section which shows the specific example of the surface mount type LED package using the resin composition of this invention.

  Hereinafter, the present invention will be described in detail. In addition, in this specification, a (meth) acryl copolymer shows an acryl copolymer and a methacryl copolymer corresponding to it, and (meth) acrylate shows an acrylate and a methacrylate corresponding to it.

  The resin composition of the present invention comprises (A) (a) an epoxy group-containing (meth) acrylate, (b) an unsaturated compound having one polymerizable unsaturated bond in one molecule, and (c) a siloxane structure In the copolymer obtained by copolymerization with (meth) acrylate, an unsaturated carboxylic acid is added at a ratio of 0.3: 1 to 0.7: 1 with an equivalent of an epoxy group and an equivalent of a carboxyl group of an unsaturated carboxylic acid. An acrylic resin obtained by reacting, (B) a curable polymerization monomer having at least one unsaturated double bond capable of being thermally or photocured, (C) a radical polymerization initiator, and (D) It contains a hindered amine light stabilizer.

  Examples of (a) epoxy group-containing (meth) acrylates include glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and among them, glycidyl. Methacrylate is preferred.

  (B) The unsaturated compound having one polymerizable unsaturated bond in one molecule is not particularly limited as long as it does not have an epoxy group. For example, methyl (meth) acrylate, ethyl (meth) acrylate , N-propyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, ethoxyethyl ( (Meth) acrylate, butoxyethyl (meth) acrylate, 2-methoxyethoxy (meth) acrylate, 2-ethoxyethoxy (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxy Triethylene glycol (meth) acrylate, butoxytriethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, pyrenoxide adduct (meth) acrylate, octafluoropentyl (meth) acrylate, N, N-dimethylaminoethyl (meth) ) Acrylate, N, N-diethylaminoethyl (meth) acrylate, cyclohexyl mono (meth) acrylate, mono (meth) acrylate with tricyclodecane, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 2-hydroxybutyl (meth) acrylate. These may be used alone or in combination of two or more.

(C) Siloxane structure-containing (meth) acrylate is a monomer having a siloxane structure in which silicon atoms and oxygen atoms are alternately bonded and a (meth) acrylate group, and is represented by the following general formula (1) or the following general formula: It is preferable that it is a compound represented by Formula (2).
Preferable specific examples of the compound represented by the general formula (1) include 3-methacryloxypropyltris (trimethylsiloxy) silane in which m = 3 and R ₁ = R ₂ = R ₃ = trimethylsiloxy group. It is done.
Preferred specific examples of the compound represented by the general formula (2) include m = 3, n = 27, R ₄ = methyl group, one-end methacryl-modified silicone oil (functional group equivalent 2,100), m = 3, n = 61, R ₄ = Methyl-terminated methacryl-modified silicone oil (functional group equivalent 4,600), m = 3, n = 161, R ₄ = Methyl-terminated methacryl-modified silicone Oil (functional group equivalent 12,000) and the like, but from the viewpoint of compatibility with the solvent, low-molecular-weight m = 3, n = 27, R ₄ = methyl group one-end methacryl-modified silicone oil (functional The group equivalent 2,100) is preferred. These may be used alone or in combination of two or more.

（ｍは０〜１０の整数、Ｒ_１、Ｒ_２、Ｒ_３は各々独立して水素原子、炭素数１〜９のアルキル基、アリール基、トリメチルシロキシ基を表す。ただし、Ｒ_１、Ｒ_２、Ｒ_３のうち少なくとも一つは、トリメチルシロキシ基である。）

(M represents an integer of 0 to 10, R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an aryl group or a trimethylsiloxy group, provided that R ₁ , R ₂ , At least one of R ₃ is a trimethylsiloxy group.)

（ｍは０〜１０の整数、ｎは０〜１５０の整数，Ｒ_４は各々独立して水素原子、炭素数１〜９のアルキル基、アリール基を表す。）

(M represents an integer of 0 to 10, n represents an integer of 0 to 150, and R ₄ each independently represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, or an aryl group.)

The component (a), the component (b), and the component (c) can be copolymerized by a known method such as a solution polymerization method in the presence of a radical polymerization initiator, for example. . The specific example is shown below.
A solvent is put in the reaction vessel and heated to 140 ° C. with stirring under a pressure condition of 0.15 MPa (1.5 kgf / cm ² ) in a nitrogen gas atmosphere. From (a) epoxy group-containing (meth) acrylate at 140 ° C., (b) unsaturated compound having one polymerizable unsaturated bond in one molecule, (c) siloxane structure-containing (meth) acrylate and radical polymerization initiator A copolymer is obtained by uniformly dropping the resulting mixture and continuing the reaction after the completion of the dropwise addition.
As a radical polymerization initiator, what can be used for normal radical polymerization, such as an azo initiator and a peroxide initiator, can be used.
Examples of azo initiators include azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, azodibenzoyl, and the like. Initiators include benzoyl peroxide, lauroyl peroxide, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-2-ethylhexanoate, 1,1-t-butylperoxy-3,3 , 5-trimethylcyclohexane, t-butylperoxyisopropyl carbonate, di-t-hexyl peroxide and the like.

  The blending ratio of the component (a) is preferably 10 to 65 mol%, and preferably 20 to 55 mol%, based on the total number of moles of the components (a), (b), and (c). Is more preferable. If the blending ratio is less than 10 mol%, the bending strength of the resin composition tends to decrease, and if it exceeds 65 mol%, the bending strength of the resin composition tends to decrease.

The blending ratio of the component (b) is 2 with respect to the total number of moles of the components (a), (b), and (c).
It is preferably 0 to 75 mol%, more preferably 30 to 65 mol%. If the blending ratio is less than 20 mol%, the bending strength of the resin composition tends to decrease, and if it exceeds 75 mol%, the bending strength of the resin composition tends to decrease.

  The blending ratio of the component (c) is preferably 10 to 65 mol%, and preferably 20 to 55 mol% with respect to the total number of moles of the components (a), (b), and (c). Is more preferable. If the blending ratio is less than 10 mol%, the bending strength of the resin composition tends to decrease, and if it exceeds 65 mol%, the bending strength of the resin composition tends to decrease.

  The weight average molecular weight of the copolymer is preferably 1,000 to 50,000, and more preferably 2,000 to 30,000. If the weight average molecular weight is less than 1,000, the mechanical properties (bending strength) and optical properties of the resin composition tend to be reduced, and if it exceeds 50,000, it is difficult to dissolve in (B) the curable polymerization monomer. Tend to be. As a method for producing a low molecular weight copolymer having a weight average molecular weight of 1,000 to 10,000, a method using a chain transfer agent, a method of adding a large amount of a radical polymerization initiator, a method of performing a reaction under higher temperature conditions, etc. Is mentioned.

In the present specification, the weight average molecular weight indicates a value measured by a gel permeation chromatography method (GPC) using a standard polystyrene calibration curve, and can be measured, for example, under the following measurement conditions. it can.
<GPC conditions>
Equipment used: Hitachi L-6000 (Hitachi, Ltd.)
Column: Gel pack GL-R420 + Gel pack GL-R430 + Gel pack GL-R440 (3 in total) [all trade names manufactured by Hitachi Chemical Co., Ltd.]
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 1.75 ml / min.
Detector: L-3300RI [Hitachi, Ltd.]

(A) Acrylic resin can be obtained by making the above-mentioned copolymer and unsaturated carboxylic acid react. The blending ratio of the copolymer and the unsaturated carboxylic acid is such that the equivalent ratio of the epoxy group and the carbonyl group is 0.3 to 0.7 equivalent ratio of the epoxy group and the carbonyl group of the unsaturated carboxylic acid in the copolymer. Although it mix | blends so that it may become (0.3: 1-0.7: 1), it is especially preferable that it is 0.4-0.6.
If the blending ratio is less than 0.3, tack remains on the surface of the cured resin after curing, and the handleability tends to be lowered, and if it exceeds 0.7, peeling tends to occur in the reflow treatment.

As the unsaturated carboxylic acid, (meth) acrylic acid is typically used.
The above reaction is carried out by reacting at 105 ° C. for 8 to 10 hours in the presence of a basic catalyst such as N, N′-diethylcyclohexylamine, triethylamine, triethanolamine, or a phosphorus catalyst such as triphenylphosphine. It can be carried out.

(A) Acrylic resin can improve light resistance and heat-resistant coloring property by refine | purifying. Purification can be performed by a known purification method, for example, it can be purified by a reprecipitation method. The specific example is shown below.
The acrylic resin solution is added dropwise to a 10-fold amount of a poor solvent (methanol: water = 50: 50) while stirring, and after completion of the addition, the supernatant is removed to obtain a precipitate. The purified (A) acrylic resin is obtained by dissolving the precipitate in a solvent, dehydrating with magnesium sulfate, filtering, and removing the solution from the solvent.

  (B) As a curable polymerization monomer having at least one unsaturated double bond capable of being thermally or photocured, those having no ether structure from the viewpoint of heat resistance, and aromatic rings from the viewpoint of light resistance. What does not contain 2 or more is preferable. Specific examples thereof include glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl. (Meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, ethoxyethyl (meth) acrylate, Butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-methoxy Toxyl (meth) acrylate, 2-ethoxyethoxy (meth) acrylate, pyrenoxide adduct (meth) acrylate, octafluoropentyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl ( (Meth) acrylate, cyclohexyl mono (meth) acrylate, mono (meth) acrylate having tricyclodecane, ethylene glycol di (meth) acrylate, methanediol di (meth) acrylate, 1,2-ethanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,3-propanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, 1, 6- Xanthdiol di (meth) acrylate, 1,7-heptanediol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol Di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, neopentyl di (meth) acrylate, dimethylol Bifunctional (meth) acrylate such as tricyclodecane di (meth) acrylate, zinc di (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, caprolactone-modified tricyclodecane dimethanol di (meth) acrylate, piece Terminal (meth) acrylic modified series Examples thereof include corn oil and (meth) acryl-modified silicone oil at both ends. These can be used alone or in combination of two or more.

  (C) As a radical polymerization initiator, a radical thermal polymerization initiator and a photoinitiator are mentioned, for example.

As a radical thermal polymerization initiator, what can be used for normal radical polymerization, such as an azo initiator and a peroxide initiator, can be used.
For example, examples of the azo initiator include azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, azodibenzoyl, and the like. Initiators include benzoyl peroxide, lauroyl peroxide, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-2-ethylhexanoate, 1,1-t-butylperoxy-3,3 , 5-trimethylcyclohexane, t-butylperoxyisopropyl carbonate, di-t-hexyl peroxide and the like.
Furthermore, in order to advance the crosslinking reaction more efficiently, it is effective to use a plurality of radical thermal polymerization initiators having different half-life temperatures in combination. For example, after curing with lauroyl peroxide at 60 ° C. for 5 hours, the reaction can be further advanced by curing with t-butylperoxyisopropyl carbonate at 120 ° C. for 1 hour.

  The photopolymerization initiator is not particularly specified as long as it efficiently absorbs and activates the ultraviolet rays of an industrial UV irradiation apparatus and does not yellow the cured resin. For example, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-methyl-1-phenyl-propan-1-one, oligo (2-hydroxy-2- Methyl-1- (4- (1-methylvinyl) phenyl) propanone, a mixture of oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone and tripropylene glycol diacrylate , And a mixture of oxy-phenyl-acetic acid 2- (2-oxo-2-phenyl-acetoxy-ethoxy) -ethyl ester and oxy-phenyl-acetic acid 2- (2-hydroxy-ethoxy) -ethyl ester, etc. Is mentioned.

  (D) As a hindered amine light stabilizer, this is also called HALS, for example, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4 -Butanetetracarboxylate (manufactured by ADEKA, trade name ADK STAB LA-52), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-butanetetracarboxylate (Trade name ADK STAB LA-57, manufactured by ADEKA), 1,2,2,6,6-pentamethyl-4-piperidyl, and tridecyl-1,2,3,4-butanetetracarboxylate (product, manufactured by ADEKA) Name Adekastab LA-62), 2,2,6,6-tetramethyl-piperidinol, tridecyl alcohol and 1,2,3,4-butanetetraca Condensate with boric acid (manufactured by ADEKA, trade name ADK STAB LA-67), 1,2,3,4-butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and β, β , Β, β-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5,5] undecane) -diethanol (product of ADEKA, trade name ADK STAB LA-68LD), Decandioic acid bis (2,2,6,6-tetramethyl-4-piperidyl) (manufactured by ADEKA, trade name ADK STAB LA-77Y), 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate ( ADEKA, trade name ADK STAB LA-82), 2,2,6,6-tetramethyl-4-piperidyl methacrylate (ADEKA, trade name ADK STAB LA-8) ), High molecular weight hindered amine light stabilizer (Ciba Specialty Chemicals, trade name CHIMASSORB 119FL, CHIMASSORB 2020FDL), poly [{6- (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}] (trade name CHIMASSORB 944FDL, manufactured by Ciba Specialty Chemicals), polymer sterically hindered amine derivative (trade name TINUVIN 622LD, manufactured by Ciba Specialty Chemicals), (Bis (1, 2, 2, 6 , 6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethyl) Ethyl) -4-hydroxyphenyl] methyl] butyl malonate (trade name TINUVIN 144, manufactured by Ciba Specialty Chemicals), methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (Ciba Specialty Chemicals) Chemicals, trade name TINUVIN 765) and the like. Among these, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate (manufactured by ADEKA, as a material that remarkably improves heat resistance and light resistance) Trade name ADK STAB LA-52), bis (2,2,6,6-tetramethyl-4-piperidyl) decanedioate (trade name ADK STAB LA-77Y, manufactured by ADEKA), methyl 1,2,2,6 6-pentamethyl-4-piperidyl sebacate (manufactured by Ciba Specialty Chemicals, trade name TINUVIN 765) is preferred. These can be used alone or in combination of two or more.

  The amount of component (B) in the resin composition of the present invention is preferably 10 to 70 parts by weight, more preferably 20 to 60 parts by weight, based on 100 parts by weight of component (A). If the amount is less than 10 parts by weight, the viscosity of the resin composition tends to be too high and becomes difficult to handle. On the other hand, if it exceeds 70 parts by weight, the bending strength tends to decrease.

  The compounding amount of the component (C) in the resin composition of the present invention is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the total amount of the component (A) and the component (B). More preferably, it is 1 part by weight. If this amount exceeds 5 parts by weight, the cured product tends to be colored by heat or near ultraviolet rays, and if it is less than 0.01 part by weight, it tends to be difficult to cure. When a plurality of thermal radical polymerization initiators having different half-life temperatures are used, the total blending amount is preferably within the above range.

  The blending amount of the component (D) in the resin composition of the present invention is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (B). 1 part by weight is particularly preferable. If the blending amount exceeds 5 parts by weight, the cured product tends to be colored, and if it is less than 0.01 part by weight, the effect of suppressing coloring tends to be small.

  In addition to the above components, phenolic or phosphorus antioxidants, ultraviolet absorbers, inorganic fillers, organic fillers, coupling agents, polymerization inhibitors, and the like can be added to the resin composition of the present invention. . Moreover, a mold release agent, a plasticizer, an antistatic agent, a flame retardant, etc. may be added from the viewpoint of moldability.

  As described above, the resin composition of the present invention described above is a resin composition having high optical transparency of the cured product, excellent in heat resistance, light resistance, mechanical properties, mounting reliability, reflow resistance, and handleability. The cured product can be used as an optical member for optical semiconductor elements such as a transparent substrate, a lens, an adhesive, an optical waveguide, a light emitting diode (LED), a phototransistor, a photodiode, and a solid-state imaging device.

The optical member of the present invention can be produced, for example, by the method shown below.
That is, an optical member can be manufactured by pouring the solution of the above-mentioned resin composition into a desired portion, casting, potting, or molding into a mold and curing by heating.
Moreover, it is desirable to reduce the oxygen concentration in the resin composition in advance by nitrogen bubbling in order to inhibit curing and prevent coloring.
As the curing conditions in the case of thermosetting, the temperature and time at which the curing is finally completed are desirable. (B) Although desirable temperature and time vary depending on the type, combination, addition amount, and the like of the curable polymerization monomer, for example, it is desirable to set the temperature at 60 to 150 ° C. for about 1 to 5 hours. Moreover, in order to reduce the internal stress generated by the rapid curing reaction, it is desirable to raise the curing temperature stepwise.

A thermoplastic resin and a thermosetting resin can be applied as a package molded product when the resin composition of the present invention is applied to a transparent sealing resin of a surface-mounted LED package (optical semiconductor device).
As the thermoplastic resin, any conventionally known thermoplastic resin such as a liquid crystal polymer, a polyphthalamide resin, or polybutylene terephthalate can be used.
As the thermosetting resin, various resins such as an epoxy resin, a silicone resin, a urethane resin, and a cyanate resin can be used. In particular, an epoxy resin is preferable because of its excellent adhesion to the transparent sealing resin. When a thermoplastic resin is used, molding is performed by injection molding, and when a thermosetting resin is used, molding is performed by transfer molding.

FIG. 1 is a schematic cross-sectional view showing a specific example of a surface-mount LED package using the resin composition of the present invention. A surface-mount LED package 200 shown in FIG. 1 includes a semiconductor light emitting element 102, a sealing body (transparent sealing resin) 104 made of a cured product obtained by curing the resin composition of the present invention, and a resin molded body 100. .
The resin molded body 100 has a structure in which a pair of leads 105 and 106 molded from a lead frame are molded with a resin portion 103 made of a thermosetting resin.
An opening 101 is formed in the resin portion 103, and the semiconductor light emitting element 102 is placed therein. And it is sealed with the sealing body 104 so that the semiconductor light emitting element 102 may be included. The semiconductor light emitting element 102 is mounted on the lead 106.
The electrode 102 a on the semiconductor light emitting element 102 and the lead 105 are connected by a wire 107. When power is supplied to the semiconductor light emitting element 102 through the two leads 105 and 106, light emission occurs, and the light emission is extracted from the light extraction surface 108 through the sealing body 104.

EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to this.
(Production Example 1)
101 parts by weight of toluene was placed in a reaction vessel and heated to 140 ° C. with stirring under a pressure of 0.15 MPa (1.5 kgf / cm ² ) under a nitrogen gas atmosphere. At 140 ° C., 114 parts by weight of the component consisting of Formulation 1 shown in Table 1 below was uniformly added dropwise over 2 hours. After completion of dropping, the reaction was further continued for 4 hours to synthesize a copolymer. The molar ratio of the obtained copolymer was (a) / (b) / (c) = 40/10/50, and the weight average molecular weight was 2,000.
Next, 214 parts by weight of this copolymer was charged with 5.3 parts by weight of acrylic acid in an amount such that the equivalent ratio of the carbonyl group of acrylic acid was 0.5, 1 part by weight of triphenylphosphine and 0.3 part by weight of hydroquinone monomethyl ether. In addition, the mixture was heated and stirred at 100 ° C. for 10 hours while blowing air at atmospheric pressure to obtain an acrylic resin (acid value: 1.5) solution having a solid content of 50% by weight. Furthermore, this acrylic resin solution was dropped into a 10-fold amount of a poor solvent (methanol: water = 50: 50) while stirring and allowed to stand for several hours, and then the supernatant was removed to obtain a precipitate. The precipitate was dissolved in THF, dehydrated with magnesium sulfate, and filtered. The solution was desolvated with an evaporator until the toluene content became 1% by weight or less to obtain a purified (A) acrylic resin (corresponding to Formulation 1 in Table 1).

(Production Examples 2 to 10)
Acrylic resins of Production Examples 2 to 10 were obtained in the same manner as Production Example 1 except that Formulation 1 in Production Example 1 was changed to each formulation (Formulations 2 to 10) shown in Table 1 below. Formulations 2 to 10 in Table 1 correspond to Production Examples 2 to 10, respectively.

ＧＭＡ：グリシジルメタクリレート ライトエステルＧ 共栄社化学株式会社製
ＭＭＡ：メチルメタクリレート 和光純薬工業株式会社製
ＨＥＭＡ：２−ヒドロキシエチルメタクリレート ライトエステルＨＯ 共栄社化学株式会社製
ＴＭ−０７０１Ｔ：３−メタクリロキシプロピルトリス（トリメチルシロキシ）シラン チッソ株式会社製
Ｘ−２４−８２０１：片末端メタクリル変性シリコーンオイル 信越化学工業株式会社製パーヘキシルＤ：ジ−ｔ−ヘキシルパーオキシド 日本油脂株式会社製

GMA: Glycidyl methacrylate Light ester G Kyoeisha Chemical Co., Ltd. MMA: Methyl methacrylate Wako Pure Chemical Industries, Ltd. HEMA: 2-hydroxyethyl methacrylate Light ester HO Kyoeisha Chemical Co., Ltd. TM-0701T: 3-Methacryloxypropyltris (trimethyl) Siloxy) Silane Chisso Co., Ltd. X-24-8201: One-end methacryl-modified silicone oil Shin-Etsu Chemical Co., Ltd. Perhexyl D: Di-t-hexyl peroxide Nihon Yushi Co., Ltd.

Example 1
50 parts by weight of (A) acrylic resin obtained in Production Example 1, 50 parts by weight of lauryl acrylate (Light acrylate LA, manufactured by Kyoeisha Chemical Co., Ltd.), 0.5 parts by weight of lauroyl peroxide (Perroyl L, manufactured by Nippon Oil & Fats Co., Ltd.) , T-butylperoxy-2-ethylhexanoate (Perbutyl I manufactured by Nippon Oil & Fats Co., Ltd.) 0.5 parts by weight, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2, 0.15 parts by weight of 3,4-butanetetracarboxylate (manufactured by ADEKA, trade name ADK STAB LA-52) was mixed at room temperature (25 ° C.) to prepare a resin composition solution. This resin solution is poured into a mold in which 3 mm and 1 mm thick silicone spacers are sandwiched between glass plates, and heated in an oven at 60 ° C. for 3 hours and 120 ° C. for 1 hour to cure to 3 mm and 1 mm thickness. I got a thing.

(Examples 2-8 and Comparative Examples 1-3)
In place of (A) acrylic resin obtained in Production Example 1, (A) acrylic resin obtained in Production Examples 2 to 10 was used, and the formulation shown in Table 2 below was used in the same manner as in Example 1. A resin composition was prepared, and cured products having a thickness of 3 mm and 1 mm were obtained.

※表中の配合量数値単位は全て重量部
ＬＡ：ラウリルアクリレート （ＮＫエステルＬＡ 新中村化学工業株式会社製）
ＭＭＡ：メチルメタクリレート （ライトエステルＭ 共栄社化学株式会社製）
ＬＰＯ：過酸化ラウロイル （パーロイルＬ 日本油脂株式会社製）
ＰＢＩ：ｔ−ブチルパーオキシ−２−エチルヘキサノエート （パーブチルＩ 日本油脂株式会社製）
ＬＡ−５２：テトラキス（１，２，２，６，６−ペンタメチル−４−ピペリジル）１，２，３，４−ブタンテトラカルボキシレート （アデカスタブ ＬＡ−５２ ＡＤＥＫＡ株式会社製）

* All the numerical values in the table are by weight LA: Lauryl acrylate (NK ester LA, Shin-Nakamura Chemical Co., Ltd.)
MMA: Methyl methacrylate (Light Ester M manufactured by Kyoeisha Chemical Co., Ltd.)
LPO: Lauroyl peroxide (Parroyl L manufactured by Nippon Oil & Fats Co., Ltd.)
PBI: t-butyl peroxy-2-ethylhexanoate (Perbutyl I manufactured by NOF Corporation)
LA-52: Tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate (Adekastab LA-52 manufactured by ADEKA Corporation)

The mechanical properties and optical properties of the cured products obtained in the above examples and comparative examples were measured by the following methods.
The flexural modulus and flexural strength were calculated as follows. That is, a 3 × 20 × 50 mm test piece is cut out from the above cured product, a bending test is performed by a three-point support in accordance with JIS-K-6911 using a three-point bending test apparatus, and bending is performed from the following formula (1). The flexural strength was calculated from the following formula (2) for the elastic modulus. The distance between fulcrums was 24 mm, the crosshead moving speed was 0.5 mm / min, the measurement temperature was room temperature (25 ° C.), and the measurement was performed at 250 ° C., which is close to the reflow temperature when mounting a semiconductor package.

（式中、Ｅｆ：曲げ弾性率（ＭＰａ）、σｆＢ：曲げ強さ（ＭＰａ）、Ｐ’：試験片が折れた時の加重（Ｎ）であり、Ｌ：支点間距離、Ｗ：試験片の幅、ｈ：試験片の厚さである。）

(Where, Ef: flexural modulus (MPa), σfB: flexural strength (MPa), P ′: weight (N) when the test piece is broken, L: distance between fulcrums, W: test piece Width, h: thickness of the test piece.)

The surface-mounted LED package used for the evaluation has the structure shown in FIG. 1, and an epoxy-based thermosetting resin was used for the package molding.
The mounting reliability of the surface-mount LED package is determined by cracking (cracking) of each resin composition in the package under a cooling temperature cycle (one cycle is set to −40 ° C./30 min-85 ° C./30 min and evaluated at 0 and 100 cycles). ), And the presence or absence of peeling (defective) between the transparent sealing resin and the package molded body. The defective product rate (= number of defects / number of packages used in the test * 100 (%)) in a predetermined number of cycles was calculated and defined as mounting reliability.

  The reflow test of the surface mount type LED package is performed by performing a reflow test under a temperature condition of a maximum temperature of 260 ° C. for 10 seconds, cracking of each resin composition in the package, and between the transparent sealing resin and the package molded body. The presence or absence of peeling (defect) was evaluated. The defective product rate after the reflow test (= number of defects / number of packages used in the test * 100 (%)) was calculated and defined as reflow resistance.

  The transmittance was measured after curing (initial stage) and after standing at high temperature for 144 hours at 150 ° C. as an evaluation of heat discoloration. The measurement was performed using a spectrophotometer with a test piece having a thickness of 1 mm. The yellowing degree (YI) indicating yellowishness was determined from the following equation (3) by determining the tristimulus value XYZ in the case of the standard light C using the measured transmission spectrum.

  Mechanical properties of the above examples and comparative examples, ie, flexural modulus and strength at room temperature (25 ° C.), mounting reliability, reflow resistance, optical properties, ie, after curing (initial) and after standing at high temperature at 400 nm The transmittance and yellowing degree are shown in Table 3.

  In Examples 1-8, all are excellent in reflow resistance. Furthermore, it can be seen that the optical characteristics are high in initial transmittance, small in yellowing, small in transmittance after standing at high temperature, and small in change in yellowing. On the other hand, in Comparative Example 1 in which the unsaturated carboxylic acid was reacted at a ratio of carboxyl group equivalent ratio of 0.8, peeling occurred in the reflow test. In Comparative Example 2 in which the unsaturated carboxylic acid was reacted at a carboxyl group equivalent ratio of 0.2, tack remained on the resin surface after curing.

  DESCRIPTION OF SYMBOLS 100 ... Resin molding, 101 ... Opening part, 102 ... Semiconductor light emitting element, 103 ... Resin part, 104 ... Sealing body (transparent sealing resin), 105, 106 ... Lead, 107 ... Wire, 108 ... Light extraction surface, 200: Surface mount type LED package.

Claims (5)

(A) (a) an epoxy group-containing (meth) acrylate, (b) an unsaturated compound having one polymerizable unsaturated bond in one molecule, and (c) a siloxane structure-containing (meth) acrylate It is obtained by reacting the unsaturated carboxylic acid with the copolymer so that the equivalent of the epoxy group and the equivalent of the carboxyl group of the unsaturated carboxylic acid are in the ratio of 0.3: 1 to 0.7: 1. Acrylic resin,
(B) a curable polymerizable monomer having at least one unsaturated double bond capable of being thermally or photocured,
A resin composition comprising (C) a radical polymerization initiator, and (D) a hindered amine light stabilizer.   The copolymer has (a) 10 to 65 mol% of an epoxy group-containing (meth) acrylate and (b) one polymerizable unsaturated bond in one molecule, based on all monomer units in the copolymer. 2. The resin composition according to claim 1, which is a copolymer copolymerized at a ratio of 20 to 75 mol% of an unsaturated compound and (c) 10 to 65 mol% of a siloxane structure-containing (meth) acrylate.   (A) The resin composition of Claim 1 or 2 whose epoxy-group-containing (meth) acrylate is glycidyl (meth) acrylate. (C) The resin composition as described in any one of Claims 1-3 whose siloxane structure containing (meth) acrylate is a compound represented by the following general formula (1) or (2).

(M represents an integer of 0 to 10, R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an aryl group or a trimethylsiloxy group, provided that R ₁ , R ₂ , At least one of R ₃ is a trimethylsiloxy group.)

(M represents an integer of 0 to 10, n represents an integer of 0 to 150, and R ₄ each independently represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, or an aryl group.)   The optical member which consists of hardened | cured material which hardened | cured the resin composition as described in any one of Claims 1-4.

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