JP4872358B2 - Resin composition, optical member using the same, and method for producing the same - Google Patents

Description

  The present invention is a resin composition having a high optical transparency of the cured product and excellent in heat resistance, light resistance and mechanical properties, and a transparent substrate, lens, adhesive, optical waveguide, light-emitting diode using the cured product ( LED), a phototransistor, a photodiode, an optical member suitable for an optical semiconductor device application such as a solid-state imaging device, and a manufacturing method thereof.

  Conventionally, acrylic resins having excellent transparency and light resistance have been widely used as optical member resins. 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 or light (particularly ultraviolet rays). Patent Documents 1 and 2 disclose methods for reducing impurities that are one of the causes of coloring contained in alicyclic bisphenol A diglycidyl ether, but further improvements in heat resistance and light coloring resistance are required. .

  In addition, epoxy resins other than those described above are generally inferior in heat resistance and light coloring resistance of resins partially containing epoxy groups. It is known that the coloring resistance of the epoxy resin is greatly influenced by the type of curing accelerator in addition to the chemical structure and impurities of the epoxy monomer. For example, when a phosphorus curing accelerator is used, Coloring is less than when an amine or imidazole curing accelerator is used. However, even if a phosphorus-based curing accelerator is used, the coloration resistance of the resin is not excellent, and further improvement thereof is required.

  Silicone resin is highly transparent up to the near-ultraviolet region and has a large Si—O bond energy, and thus has excellent light resistance and is difficult to be colored by heat or light. In general, silicone resins are polymerized by dehydration condensation reaction between silanol groups, condensation reaction between silanol groups and hydrolyzable groups, reaction by organic peroxide of methylsilyl group and vinylsilyl group, addition reaction of vinylsilyl group and hydrosilyl group, etc. Is done. For example, Patent Document 3 discloses a silicone resin obtained by an addition reaction between a vinylsilyl group and a hydrosilyl group. However, the silicone resin obtained by utilizing these reactions also has problems such as the case where the curing does not proceed due to the influence of the catalyst poison due to the curing atmosphere, and the thermal expansion coefficient of the cured product is large.

  On the other hand, improvement of heat resistance, which is a drawback of acrylic resins having excellent optical properties, has been studied, and there is an example of introducing a crosslinked structure between acrylic main chains. For example, Patent Document 4 discloses a reaction product resulting from crosslinking with a (meth) acrylic polymer containing an epoxy group and a polyvalent carboxylic acid. However, as shown in the examples, since the (meth) acrylic polymer containing an epoxy group is insoluble in the polyvalent carboxylic acid of the curing agent, it can be dissolved in an organic solvent and molded and cured. Must not. Non-patent document 1 reports an example in which a low molecular weight (meth) acrylic polymer containing an epoxy group is dissolved in a liquid epoxy monomer and reacted with a curing agent. However, since this system also uses a liquid epoxy monomer that is inferior in heat resistance and light resistance as a solubilizer for the (meth) acrylic polymer, further improvement in properties is required.

Patent Documents 5 and 6 describe that a cured resin product having excellent storage stability and electrical insulation can be obtained by using an aluminum compound as a curing catalyst for an epoxy resin. However, even if an aluminum compound is used as a curing catalyst for bisphenol A type, phenol novolac type, alicyclic type, and bisphenol F type epoxy resins as described in Examples of Patent Documents 5 and 6. The cured product has insufficient heat resistance and light coloring resistance as an optical member for use in optical semiconductor elements.
JP 2003-171439 A JP 2004-75894 A JP 2004-186168 A JP 2003-160640 A Japanese Examined Patent Publication No. 61-2629 JP-A-8-134188 "Proceedings of the 53rd Network Polymer Lecture Meeting" p49-52 “Network Polymer” Vol. 24, N0.3 (2003) p148-155

  In view of the above, the present invention is solvent-free and liquid at room temperature, is easy to mold and cure, and is excellent in optical transparency, light coloring resistance, heat resistance and mechanical properties of the cured product, and suitable for optical members. An object of the present invention is to provide a resin composition, an optical member using the same, and a method for producing the same.

  As a result of intensive studies, the present inventors have a metal chelate and an alkoxy group having an acetoacetate derivative as a ligand as a curing accelerator for a resin composition containing an epoxy group-containing (meth) acrylate and an acid anhydride. In order to achieve the present invention, it has been found that when a silicon compound is used, it is possible to improve the light coloring resistance of a resin cured product, in particular, compared with the case of using an amine-based, imidazole-based, or phosphorus-based curing accelerator. It has come. In addition, when such a curing accelerator is used, compared with the case where a phosphorus-based curing accelerator is used, while maintaining the elastic modulus in the high temperature range above the glass transition temperature of the cured product, It has also been found that the elastic modulus can be reduced and a low-stress cured product can be obtained.

  That is, the present invention is characterized by the following items (1) to (9).

  (1) In a resin composition containing an epoxy group-containing (meth) acrylate, an acid anhydride, a radical polymerization initiator, and a curing accelerator, the curing accelerator is a metal chelate and an alkoxy group having an acetoacetate derivative as a ligand. A resin composition characterized by being a silicon compound having a liquefaction and being liquid at room temperature (25 ° C.) and being cured by heating or light irradiation.

  (2) The resin composition as described in (1) above, further comprising a (meth) acrylate monomer.

  (3) The resin composition as described in (1) or (2) above, further comprising an epoxy group-containing (meth) acrylic copolymer having a weight average molecular weight of 20,000 or less.

  (4) The resin composition as described in any one of (1) to (3) above, wherein the central metal of the metal chelate is Al or Zr.

  (5) The resin composition as described in any one of (1) to (4) above, wherein the silicon compound is any one of tetraalkoxysilane, trialkoxysilane, dialkoxysilane, and monoalkoxysilane. .

  (6) It is characterized in that both radical polymerization of (meth) acrylates contained in the composition and ionic polymerization of epoxy groups and acid anhydrides contained in the composition proceed and cure by heating or light irradiation. The resin composition according to any one of (1) to (5) above.

  (7) A first liquid containing the epoxy group-containing (meth) acrylate, and optionally containing a (meth) acrylate monomer and / or an epoxy group-containing (meth) acrylic copolymer, the acid anhydride, and the radical The resin composition according to any one of (1) to (6) above, wherein the resin composition is mixed with a polymerization initiator and a second liquid containing the curing accelerator and cured by heating or light irradiation. .

  (8) An optical member produced by curing the resin composition according to any one of (1) to (7).

  (9) Using the resin composition according to any one of (1) to (7) above, radical polymerization of (meth) acrylates contained in the resin composition is performed by light irradiation, and the resin composition A method for producing an optical member, characterized in that ionic polymerization of an epoxy group and an acid anhydride contained in is performed by subsequent heating.

  According to the present invention, a resin composition that is solventless and liquid at room temperature, is easy to mold and cure, and has excellent optical transparency, light coloring resistance, heat resistance, and mechanical properties, and is suitable for optical members. Things can be provided. Moreover, the optical member of the present invention obtained by curing the resin composition of the present invention having such characteristics can improve the life and reliability of an optical element using the optical member. Furthermore, since the method for producing the optical member of the present invention uses the resin composition of the present invention that is liquid at room temperature and can be easily molded and cured, the optical member of the present invention can be easily provided. .

  The resin composition of the present invention comprises an epoxy group-containing (meth) acrylate as a monomer component, an acid anhydride as a curing agent for an epoxy, a radical polymerization initiator, a metal chelate having an acetoacetate derivative as a ligand as an epoxy curing accelerator, and Contains a silicon compound having an alkoxy group. In addition to this, it is preferable to contain (meth) acrylate or an epoxy group-containing (meth) acrylic copolymer having a weight average molecular weight of 20,000 or less as a monomer component.

  The resin composition of the present invention forms an acrylic main chain by radical polymerization of (meth) acrylates (epoxy group-containing (meth) acrylate, (meth) acrylate, etc.) contained in the resin composition, By ionic polymerization of an acid anhydride with an epoxy group (epoxy group of an acrylic polymer side chain, an epoxy group-containing (meth) acrylate or an epoxy group of an epoxy group-containing (meth) acrylic copolymer) contained in the resin composition, Since crosslinks within and between the acrylic main chains are formed, it is possible to achieve both excellent optical properties of the acrylic resin and excellent heat resistance and mechanical properties of the epoxy resin.

  The radical polymerization of acrylate and the ionic polymerization of an epoxy group and an acid anhydride to modify the epoxy resin with acrylate are described in, for example, “Network Polymer” Vol. 24, N0.3 (2003) p148-155 (Non-Patent Document 3), these use an acrylate monomer and an epoxy monomer to form an interpenetrating polymer network structure that is separately crosslinked. Therefore, there exists a problem that characteristics, such as transparency of hardened | cured material, fall.

  On the other hand, in the material system of the resin composition of the present invention, an epoxy group-containing (meth) acrylate and an acid anhydride are used to form a crosslinked structure of an epoxy group and an acid anhydride within and between the acrylic main chains. Therefore, a cured resin having a uniform and high transparency can be obtained.

  The epoxy group-containing (meth) acrylate used in the present invention is not particularly limited, and examples thereof include glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and 1,4-hydroxybutyl. Examples thereof include acrylate glycidyl ether, and glycidyl methacrylate is particularly preferable. Here, “(meth) acrylate” used in the present invention means acrylate or methacrylate.

  The acid anhydride used in the present invention is not particularly limited, but is an acid anhydride that is liquid at 25 ° C., such as methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hydrogenated methylnadic. Acid anhydrides, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride and the like can be mentioned, among which alicyclic acid anhydrides are preferable, and methylhexahydrophthalic anhydride and hydrogenated methylnadic acid anhydride are particularly preferable.

  Moreover, it is preferable that the compounding quantity of the said acid anhydride shall be 0.5-1.2 by the equivalent ratio (acid anhydride group / epoxy group) of the acid anhydride group and an epoxy group. When this equivalent ratio is larger than 1.2, the cured resin is easily colored by heat or ultraviolet rays. On the other hand, if the equivalent ratio is less than 0.5, the heat resistance of the resin cured product tends to decrease.

  As the radical polymerization initiator used in the present invention, any one that can be used for normal radical polymerization, such as an azo initiator and a peroxide initiator, can be used. 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, and the like.

  When radical polymerization is performed by photoradical polymerization, a radical photopolymerization initiator may be used instead of the radical thermal polymerization initiator such as the azo initiator or peroxide initiator. it can. The radical photopolymerization initiator is not particularly limited as long as it efficiently absorbs and activates 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 oxy-phenyl-acetic acid -2- (2-Oxo-2-phenyl-acetoxy-ethoxy) -ethyl ester and oxy-phenyl Acetate tic acid 2- (2-hydroxy - ethoxy) - mixture of ethyl esters.

  The amount of the radical polymerization initiator is preferably 0.01 to 5 parts by weight, particularly 0.1 to 1 part by weight based on 100 parts by weight of the total amount of (meth) acrylates. preferable. If this amount exceeds 5 parts by weight, the cured resin is likely to be colored by heat and ultraviolet rays, and if it is less than 0.01 parts by weight, the resin composition tends to be difficult to cure.

  The epoxy curing accelerator used in the present invention is preferably a metal chelate having an acetoacetate derivative as a ligand and a silicon compound having an alkoxy group.

  The metal chelate is not particularly limited, but the central metal is preferably Al or Zr. For example, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate), alkyl acetoacetate aluminum diisopropylate, Aluminum monoacetylacetonate bis (ethyl acetoacetate), aluminum tris (acetylacetonate), zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium butoxyacetylacetonate bis (ethylacetoacetate), zirconium (acetylacetonate) ) Bis (ethyl acetoacetate) and the like are preferred.

  The silicon compound is more preferably a silicon compound having an alkoxy group, and particularly preferably a silicon compound having an alkoxy group having 2 to 6 carbon atoms. More specifically, tetraethoxysilane, triethoxymethylsilane, diethoxydimethylsilane, ethoxytrimethylsilane, triethoxypropylsilane, triethoxyhexylsilane and the like are preferable.

  Moreover, the compounding quantity of the said hardening accelerator, ie, the metal chelate which uses an acetoacetate derivative as a ligand, and the silicon compound which has an alkoxy group, respectively is 0.01-5 weight part with respect to 100 weight part of total amounts of a resin solution. The content is preferably 0.1 to 1 part by weight. If this amount exceeds 5 parts by weight, the cured resin is likely to be colored by heat and ultraviolet rays, and if it is less than 0.01 parts by weight, the resin composition tends to be difficult to cure.

  The (meth) acrylate used in the present invention is not particularly limited. For example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, Examples include bornyl methacrylate, n-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, benzyl acrylate, and isobornyl acrylate. These can be used alone or in combination of two or more. . The (meth) acrylate may be a polyfunctional (meth) acrylate. For example, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6 -Hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, dimethylol-tricyclodecane dimethacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, 1,6 -Hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, neopentyl glycol diacrylate, 3-methyl-1,5- Nthanediol diacrylate, 1,6-hexanediol diacrylate 2-butyl-2-ethyl-1,3-propanediol diacrylate, 1,9-nonanediol diacrylate, dimethylol-tricyclodecane diacrylate, ethoxylated isocyanur An acid triacrylate etc. are mentioned. Further, the (meth) acrylate may be a (meth) acrylate containing a siloxane structure. For example, (3-acryloxypropyl) tris (trimethylsiloxy) silane, (3-methacryloxypropyl) tris (trimethyl) (Siloxy) silane, (2-acryloxyethoxy) trimethylsilane, (3-acryloxypropyl) trimethylsilane, (3-acryloxypropyl) dimethylmethoxysilane, (3-acryloxypropyl) methyldimethoxysilane, (3- (Acryloxypropyl) methylbis (trimethylsiloxy) silane, (2-methacryloxyethoxy) trimethylsilane, (3-methacryloxypropyl) trimethoxysilane, (3-methacryloxypropyl) trimethylsilane, (3-methacryloxy) Propyl) dimethylmethoxysilane, (3-methacryloxypropyl) methyldimethoxysilane, (3-methacryloxypropyl) methylbis (trimethylsiloxy) silane, etc., among which (3-acryloxypropyl) tris (trimethylsiloxy) silane, (3-Methacryloxypropyl) tris (trimethylsiloxy) silane is preferred. Further, di (meth) acrylate having a siloxane main chain may be used as the polyfunctional silicone acrylate. By blending the (meth) acrylate as described above into the resin composition of the present invention, the epoxy group concentration in the acrylic main chain formed from the epoxy group-containing (meth) acrylate can be adjusted, and optimal cured product properties can be obtained. can get.

  Moreover, it is preferable to mix | blend the compounding quantity of the said epoxy group containing (meth) acrylate and the said (meth) acrylate so that each weight ratio may be 100: 0-30: 70, 70: 30-30: 70. It is particularly preferable to blend so that When the ratio of the epoxy group-containing (meth) acrylate is less than 30, the crosslinking density becomes too small, so that the heat resistance is lowered and tends to be brittle. On the other hand, when the ratio of the epoxy group-containing (meth) acrylate exceeds 70, it is difficult to obtain the effect of blending (meth) acrylate.

  Although it does not specifically limit as said epoxy group containing (meth) acrylic copolymer used by this invention, For example, the copolymer of the said epoxy group containing (meth) acrylate mentioned as a monomer component and the said (meth) acrylate is mentioned. It is done. Accordingly, the epoxy group-containing (meth) acrylic copolymer may be a copolymer comprising the same epoxy group-containing (meth) acrylate and (meth) acrylate as the monomer component, or an epoxy group-containing (meth) acrylate different from the monomer component. And a (meth) acrylate copolymer. However, since the epoxy group-containing (meth) acrylic copolymer is soluble in the monomer component and the epoxy curing agent, the molecular weight is preferably low, and the weight average molecular weight is particularly preferably 20,000 or less. (The weight average molecular weight is measured by gel permeation chromatography (GPC) and converted to standard polystyrene). In the case of solution polymerization, such a low molecular weight copolymer can be obtained by performing polymerization conditions at a high temperature or by adding a chain transfer agent. By blending the epoxy group-containing (meth) acrylic copolymer as described above with the resin composition of the present invention, a crosslinked structure of an epoxy group and an acid anhydride can be formed in the acrylic main chain and between the main chains, and cured. A cured product having small shrinkage, uniform and high transparency can be obtained.

  The compounding amount of the epoxy group-containing (meth) acrylic copolymer is 0: 100 to 50:50 by weight ratio of the epoxy group-containing (meth) acrylic copolymer: epoxy group-containing (meth) acrylate and (meth) acrylate. It is preferable to mix | blend so that it may become 50, and it is especially preferable to mix | blend so that it may become 10: 80-40: 60. Here, when the ratio of the epoxy group-containing (meth) acrylic copolymer is less than 10, it is difficult to obtain the effect of reducing curing shrinkage. On the other hand, if the ratio of the epoxy group-containing (meth) acrylic copolymer is more than 50, it may be difficult to dissolve or the crosslink density may be too low, resulting in a decrease in heat resistance.

  In addition to the above components, the resin composition of the present invention includes hindered amine light stabilizers, phenolic and phosphorus antioxidants, ultraviolet absorbers, inorganic fillers, organic fillers, coupling agents, and polymerization inhibition. An agent or the like can be added. Moreover, a mold release agent, a plasticizer, an antistatic agent, a flame retardant, etc. may be added from the viewpoint of moldability. These are preferably liquid from the viewpoint of ensuring the light transmittance of the cured resin, but in the case of a solid, it is desirable to have a particle size equal to or smaller than the wavelength used.

  As the form of the resin composition of the present invention, epoxy group-containing (meth) acrylate, acid anhydride, radical polymerization initiator, curing accelerator, and in some cases (meth) acrylate, epoxy group-containing (meth) acrylic copolymer May be a resin solution prepared by mixing an epoxy group-containing (meth) acrylate, optionally a (meth) acrylate and / or an epoxy group-containing (meth) acrylic copolymer, a first liquid, an acid anhydride, a radical The resin composition may be divided into a second liquid containing a polymerization initiator and a curing accelerator, and the first liquid and the second liquid may be mixed at the time of use to form the resin composition of the present invention. By dividing in this way, each storage stability can be improved.

  The optical member of the present invention is prepared by pouring the resin composition of the present invention, which is a liquid (including a viscous liquid state) at room temperature (25 ° C.), into a desired portion, casting, potting, or mold, Can be obtained by curing by heating or light irradiation. 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. The cross-linked structure of the cured resin (optical member) depends on the relationship between the half-life temperature of the radical polymerization initiator used and the gelation temperature of the epoxy curing accelerator, but generally the half-life temperature of the radical polymerization initiator. Is lower than the gelation temperature of the epoxy curing accelerator, first, radical polymerization of (meth) acrylates proceeds, a (meth) acryl main chain is formed, and then ionic polymerization of epoxy groups and acid anhydrides proceeds. As a result, a crosslinked structure is formed in the acrylic main chain and between the main chains. However, by selecting a combination in which the half-life temperature of the radical polymerization initiator and the gelation temperature of the epoxy curing accelerator are close, there is no steric restriction of the acrylic main chain, and a denser cross-linked structure can be obtained. Conceivable.

  The curing conditions in the case of thermosetting depend on the type, combination, and amount of each component, but are not particularly limited as long as the temperature and time are finally completed for both radical polymerization and ionic polymerization. Is about 1 to 5 hours at 60 to 150 ° C. Moreover, in order to reduce the internal stress generated by the rapid curing reaction, it is desirable to raise the curing temperature stepwise. In addition, in order to easily obtain a cured product in a shorter time, first, photoradical polymerization of (meth) acrylates is performed by light irradiation, and then this is heated to perform ionic polymerization of an epoxy group and an acid anhydride. It is possible and preferred.

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

  Hereinafter, the present invention will be specifically described by way of examples.

Example 1
35 parts by weight of glycidyl methacrylate as an epoxy group-containing (meth) acrylate, 35 parts by weight of (3-methacryloxypropyl) tris (trimethylsiloxy) silane as a (meth) acrylate, 30 parts by weight of methylhexahydrophthalic anhydride as an acid anhydride, As radical polymerization initiator, 0.3 parts by weight of azobisisobutyronitrile and 0.5 parts by weight of aluminum tris (acetylacetonate) and 0.5 parts by weight of diethoxydimethylsilane as an epoxy curing accelerator were added at room temperature (25 ° C. ) To prepare a liquid 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 80 ° C., 100 ° C., 125 ° C., and 150 ° C. for 1 hour each. A cured product having a thickness of 3 mm and 1 mm was obtained.

(Example 2)
A liquid resin composition solution was prepared in the same manner as in Example 1 except that zirconium tetra (acetylacetonate) was used instead of aluminum tris (acetylacetonate) to obtain cured products having a thickness of 3 mm and 1 mm. It was.

(Example 3)
A liquid resin composition solution was prepared in the same manner as in Example 1 except that zirconium tri (butoxy) acetylacetonate was used instead of aluminum tris (acetylacetonate), and cured products having thicknesses of 3 mm and 1 mm were obtained. Obtained.

Example 4
A liquid resin composition solution was prepared in the same manner as in Example 1 except that zirconium (acetylacetonato) bis (ethylacetoacetate) was used instead of aluminum tris (acetylacetonate), and the thickness was 3 mm and 1 mm. A cured product was obtained.

(Example 5)
The amount of glycidyl methacrylate is 28 parts by weight, and (meth) acrylate is 14 parts by weight of isobornyl acrylate instead of (3-methacryloxypropyl) tris (trimethylsiloxy) silane. A liquid resin composition solution was prepared in the same manner as in Example 1 except that 28 parts by weight of a copolymer (number average molecular weight: 4,000 and epoxy equivalent: 310) was blended. A cured product was obtained.

(Example 6)
35 parts by weight of glycidyl methacrylate as an epoxy group-containing (meth) acrylate, 35 parts by weight of (3-methacryloxypropyl) tris (trimethylsiloxy) silane as a (meth) acrylate, 30 parts by weight of methylhexahydrophthalic anhydride as an acid anhydride, 1 part by weight of 1-hydroxycyclohexyl phenyl ketone as a radical photopolymerization initiator, 0.5 part by weight of aluminum tris (acetylacetonate) and 0.5 part by weight of diethoxydimethylsilane as an epoxy curing accelerator at room temperature (25 ° C.) To prepare a liquid resin composition solution. This resin solution was poured into a mold in which a 3 mm thick and 1 mm thick silicone spacer was sandwiched between glass plates, and then an ultrahigh pressure mercury lamp was used to produce an illuminance of 11.6 mW / cm ² and an integrated exposure amount of 3000 mJ / cm. Radical polymerization was performed under the conditions of ² , and further heated in an oven at 100 ° C., 125 ° C., 150 ° C. for 1 hour each to obtain cured products having a thickness of 3 mm and 1 mm.

(Comparative Example 1)
A liquid resin composition solution was prepared in the same manner as in Example 1 except that tetrabutylphosphonium diethylphosphodithionate was used as an epoxy curing accelerator to obtain cured products having a thickness of 3 mm and 1 mm.

(Comparative Example 2)
A liquid resin composition solution was prepared in the same manner as in Example 3 except that only zirconium tri (butoxy) acetylacetonate was used as an epoxy curing accelerator to obtain cured products having a thickness of 3 mm and 1 mm.

(Comparative Example 3)
A liquid resin composition solution was prepared in the same manner as in Example 1 except that only diethoxydimethylsilane was used as an epoxy curing accelerator, and cured products having a thickness of 3 mm and 1 mm were obtained.

The compositions of Examples 1-6 and Comparative Examples 1-3 are summarized in Table 1.

  The numbers in Table 1 are parts by weight, A: glycidyl methacrylate (light ester G, manufactured by Kyoeisha Chemical Co., Ltd.), B1: (3-methacryloxypropyl) tris (trimethylsiloxy) silane (X-22-2404, Shin-Etsu Chemical Co., Ltd.) B2: Isobornyl acrylate (IBXA, manufactured by Osaka Organic Chemical Industry), C: Copolymer of methyl methacrylate and glycidyl methacrylate, D: Methyl hexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.) ), E1: Azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries), E2: 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.), F1: Aluminum tris (acetylacetonate) (ALW) , Kawaken Fine Chemical Co., Ltd.), F : Zirconium tetra (acetylacetonate) (ZC-150, manufactured by Matsumoto Pharmaceutical), F3: Zirconium tri (butoxy) acetylacetonate (ZC-540, manufactured by Matsumoto Pharmaceutical), F4: Zirconium (acetylacetonate) bis ( Ethyl acetoacetate) (ZC-570, manufactured by Matsumoto Pharmaceutical Co., Ltd.), G: Diethoxydimethylsilane (LS-1370, manufactured by Shin-Etsu Silicone), H: Tetrabutylphosphonium diethylphosphodithionate (Hishicolin PX-4ET, Nippon Chemical Industry Co., Ltd.) Company).

  Regarding the resin cured products obtained in Examples 1 to 6 and Comparative Examples 1 to 3, the glass transition temperature, the flexural modulus, the initial light transmittance and the yellowing degree after standing at high temperature, and the light resistance to coloring are as follows. It was measured by the method shown.

  The glass transition temperature (Tg) was measured using a differential thermomechanical analyzer (TAS100 model manufactured by Rigak) by cutting out a 3 × 3 × 20 mm test piece from a 3 mm thick resin cured product. The thermal expansion of the sample was measured at a temperature elevation rate of 5 ° C./min, and Tg was determined from the inflection point of the thermal expansion curve.

（式（１）中、Ｅｆ：曲げ弾性率（ＭＰａ）、ΔＰ：加重（Ｎ）、ΔＹ：変位量（ｍｍ）、Ｌｖ：支点間距離、Ｗ：試験片の幅、ｈ：試験片の厚さである。） The bending elastic modulus was cut out from a 3 × 20 × 50 mm test piece, and subjected to a bending test with a three-point support in accordance with JIS-K-6911 using a three-point bending test apparatus (Instron 5548 type). The flexural modulus was calculated from (1). 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 250 ° C., which is close to the reflow temperature when mounting the optical semiconductor package.

(In the formula (1), Ef: flexural modulus (MPa), ΔP: weight (N), ΔY: displacement (mm), Lv: distance between fulcrums, W: width of test piece, h: thickness of test piece That's it.)

The light transmittance and the yellowing degree were measured with a 1 mm-thick test piece using a spectrophotometer (Hitachi spectrophotometer V-3310). The transmittance was measured after curing (initial stage) and after leaving at a high temperature at 150 ° C. for 300 hours as an evaluation of heat resistance coloring property. The yellowing degree (YI) indicating yellowishness was determined from the following equation (2) by determining the tristimulus value XYZ in the case of the standard light C using the measured transmission spectrum.

For light-coloring resistance, a spot UV irradiator (SP-7, manufactured by USHIO INC.) Is used as a light source, and near-ultraviolet light having a wavelength of 365 nm (illuminance: 5000 mW / cm ² ) as a main component is irradiated onto a 1 mm thick test piece The time at which the transmittance at 380 nm became 70% or less of the initial transmittance was expressed.

Glass transition temperature of each test piece of Examples 1-6 and Comparative Examples 1-3, bending elastic modulus at room temperature (25 ° C.) and 250 ° C., after curing (initial) and at a wavelength of 400 nm after standing at high temperature Table 2 shows the light transmittance, yellowing degree, and light resistance. In addition, the resin hardened | cured material of the comparative examples 2 and 3 was inadequate hardening, and could not measure various physical properties.

  Each of the test pieces of Examples 1 to 6 has a glass transition temperature of 150 ° C. or higher and excellent heat resistance, and a high bending elastic modulus at a high temperature of 70 MPa or more. In addition, it can be seen that the optical characteristics are high in initial transmittance, low in yellowing, low in transmittance after leaving at high temperature at 150 ° C. for 300 hours, and small in change in yellowing. Furthermore, it turns out that it is excellent also in light resistance. On the other hand, as shown in Comparative Example 1, when a phosphorus curing accelerator is used as the epoxy curing accelerator, it can be seen that the light transmittance and yellowing degree after high-temperature treatment and the light-coloring resistance are inferior.

Claims (7)

In the resin composition containing an epoxy group-containing (meth) acrylate, an acid anhydride, a radical polymerization initiator, a curing accelerator, and an epoxy group-containing (meth) acrylic copolymer having a weight average molecular weight of 20,000 or less , the curing A resin composition characterized in that the accelerator is a metal chelate having an acetoacetate derivative as a ligand and a silicon compound having an alkoxy group, is liquid at room temperature (25 ° C.), and is cured by heating or light irradiation. . The resin composition according to claim 1 , wherein a central metal of the metal chelate is Al or Zr. Wherein the silicon compound is tetraalkoxysilane, trialkoxysilane, dialkoxysilane, resin composition according to claim 1 or 2, characterized in that either a monoalkoxysilane. The radical polymerization of (meth) acrylates contained in the composition and the ionic polymerization of epoxy groups and acid anhydrides contained in the composition both proceed and cure by heating or light irradiation. Item 4. The resin composition according to any one of Items 1 to 3 . A first liquid containing the epoxy group-containing (meth) acrylate and an epoxy group-containing (meth) acrylic copolymer, and a second liquid containing the acid anhydride, the radical polymerization initiator, and the curing accelerator. It mixes and it hardens | cures by heating or light irradiation, The resin composition in any one of Claims 1-4 characterized by the above-mentioned. An optical member, characterized in that manufactured by curing the resin composition according to any one of claims 1-5. Using the resin composition according to any one of claims 1 to 5 , radical polymerization of (meth) acrylates contained in the resin composition is performed by light irradiation, and epoxy groups contained in the resin composition A method for producing an optical member, wherein the ionic polymerization of an acid anhydride is performed by subsequent heating.