JP2006131868A - Resin composition, optical member using the same composition and method for producing the same optical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition having high optical transparency of a cured product and excellent in light resistance, heat resistance and mechanical properties, having small curing shrinkage and further excellent in storage stability, and an optical member using the resin composition, having high optical transparency, excellent in light resistance, heat resistance and mechanical properties and having small curing shrinkage and to provide a production method capable of simply preparing the optical member in a short time. <P>SOLUTION: The resin composition comprises an epoxy group-containing (meth)acrylate as a monomer component (A), a (meth)acrylate as a monomer component (B), an acrylic oligomer having a polymerization reaction property as a component (C) and an acid anhydride as an epoxy curing agent (D). The resin composition is liquid at 25°C and the resin composition is cured by heating or light irradiation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 optical semiconductor element applications 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 and light. For example, Patent Documents 1 and 2 disclose a method for reducing impurities that are one of the causes of coloring contained in alicyclic bisphenol A diglycidyl ether, but further improvement in heat resistance and ultraviolet coloring resistance is required. It has been.

  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 3 discloses a reaction product obtained by 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.

  In addition, acrylic resins have a drawback that the amount of cure shrinkage is large. This is because, unlike the ring-opening polymerization reaction of epoxy, in the case of acrylate, the Van de Waals distance of the monomer is reduced to the covalent bond distance by radical polymerization. Due to the curing shrinkage, a stress is generated in the cured product of the acrylic resin, and there is a problem that the adhesion to the adherend is inferior.

Therefore, a resin composition suitable for an optical member, which is a solvent-free system, is liquid at room temperature, is easy to mold and cure, has excellent transparency, light resistance, heat resistance, mechanical properties, and has a small curing shrinkage. Is desired.

JP 2003-171439 A JP 2004-75894 A JP 2003-160640 A Proceedings of the 53rd Network Polymer Lecture Meeting "p49-52 “Network Polymer” Vol. 24, N0.3 (2003) p148-155

  The present invention provides a resin composition in which the cured product has high optical transparency, excellent light resistance, heat resistance and mechanical properties, small curing shrinkage, and excellent storage stability. In addition, the present invention provides an optical member having high optical transparency, excellent light resistance, heat resistance, mechanical properties, small curing shrinkage using the resin composition, and further simplifying the optical member in a short time. The manufacturing method to produce is provided.

  The present invention provides [1] an epoxy group-containing (meth) acrylate as the monomer component (A), (meth) acrylate as the monomer component (B), a polymerizable reactive acrylic oligomer as the component (C), and an epoxy curing agent (D). It is a resin composition that contains an acid anhydride, is liquid at 25 ° C., and is cured by heating or light irradiation.

  Moreover, the present invention is [2] the resin composition as described in [1] above, further comprising a radical polymerization initiator (E) and an epoxy curing accelerator (F).

  [3] The above-mentioned [1] or [2], wherein the polymerization-reactive acrylic oligomer of [3] component (C) is an acrylic oligomer (macromonomer) having a (meth) acryloyl group terminal. It is a resin composition as described in above.

  In the present invention, [4] radical polymerization of monomer component (A), monomer component (B) and component (C) and ion polymerization of monomer component (A) and epoxy curing agent (D) are heated or The resin composition according to any one of [1] to [3], which proceeds by light irradiation.

  The present invention also provides [5] a first liquid containing a monomer component (A), a monomer component (B) and a component (C), an epoxy curing agent (D), a radical polymerization initiator (E) and an epoxy. The resin composition according to any one of [2] to [4] above, wherein the resin composition is mixed with a second liquid containing a curing accelerator (F) and cured by heating or light irradiation. .

  The present invention also provides [6] an optical member produced by curing the resin composition according to any one of [1] to [5].

  The present invention also provides [7] radical polymerization of the monomer component (A), the monomer component (B) and the component (C) using the resin composition according to any one of [1] to [5]. It is a method for producing an optical member, characterized in that it is carried out by light irradiation and ion polymerization of the monomer component (A) and the epoxy curing agent (D) is carried out by subsequent heating.

  The resin composition of the present invention has high optical transparency of the cured product, little decrease in transmittance after storage at high temperature, high bending strength at high temperature, excellent heat resistance and mechanical properties, and shrinkage on curing. Since it is small, it is suitable as a resin composition for electronic materials such as a sealing resin for optical semiconductors. Moreover, the resin composition of this invention is excellent also in storage stability. And the lifetime and reliability of an optical element improve by applying the resin composition of this invention which is excellent in heat resistance and light resistance, and has small cure shrinkage to an optical member. Moreover, the manufacturing method of the optical member of this invention can obtain hardened | cured material easily in a short time.

  The resin composition of the present invention comprises an epoxy group-containing (meth) acrylate as the monomer component (A), a (meth) acrylate as the monomer component (B), a polymerization-reactive acrylic oligomer as the component (C), and an epoxy curing agent (D ) As an acid anhydride. Furthermore, it is preferable to contain a radical polymerization initiator (E) and an epoxy curing accelerator (F).

  The resin composition of the present invention is a radical polymerization of epoxy group-containing (meth) acrylate (monomer (A) component), (meth) acrylate (monomer (B) component), and polymerization-reactive acrylic oligomer (component (C)). Acrylic main chain is formed by ionic polymerization of the acrylic side chain epoxy group and acid anhydride (epoxy curing agent (D)) to form crosslinks within the acrylic main chain and between the main chains, and further polymerization reaction When the acrylic oligomer is graft-polymerized to the acrylic main chain by radical polymerization of the functional acrylic oligomer, the crosslinking density can be appropriately reduced due to the steric hindrance to balance heat resistance and mechanical properties. At the same time, curing shrinkage can be reduced by containing an acrylic oligomer.

  Performing radical polymerization of acrylate and ionic polymerization of an epoxy group and an acid anhydride and modifying an epoxy resin with acrylate is described in, for example, “Network Polymer” Vol. 24, N0.3 (2003) p148-155. However, these use an acrylate monomer and an epoxy monomer, and have a problem that the properties such as transparency are deteriorated in order to form an interpenetrating polymer network structure that is separately crosslinked.

  On the other hand, in the material system of the resin composition of the present invention, by using an epoxy group-containing (meth) acrylate, (meth) acrylate, a polymerization reactive acrylic oligomer and an acid anhydride, the acrylic main chain and between the main chains are used. Since a cross-linked structure of an epoxy group and an acid anhydride is formed and an acrylic side chain is formed, uniform and high transparency can be obtained.

  Although it does not specifically limit as an epoxy-group containing (meth) acrylate which is a monomer component (A) used by this invention, For example, glycidyl methacrylate, 3,4-epoxy cyclohexyl methyl acrylate, 3,4-epoxy cyclohexyl methyl methacrylate, Examples include 1,4-hydroxybutyl acrylate glycidyl ether, and glycidyl methacrylate is particularly preferable. Here, “(meth) acrylate” used in the present invention means acrylate and methacrylate (hereinafter the same).

  Although it does not specifically limit as (meth) acrylate which is a monomer component (B) used by this invention, For example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, Examples include isobornyl methacrylate, n-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate, benzyl acrylate, and isobornyl acrylate, and these can be used alone or in combination of two or more. Moreover, the monomer component (B) may contain polyfunctional (meth) acrylate. Examples of the polyfunctional (meth) acrylate include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, and 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-pentanediol diacrylate, 1,6- Hexanediol diacrylate 2-butyl-2-ethyl-1,3-propanediol diacrylate, 1,9-nonanediol diacrylate, dimethylol - diacrylate, and the like ethoxylated isocyanuric acid triacrylate.

  Although it does not specifically limit as a polymerization reactive acrylic oligomer of the component (C) in this invention, It is preferable that it is an acrylic oligomer containing 1 or more of (meth) acryloyl groups, and the (meth) acryloyl group terminal acrylic oligomer ( More preferably, it is a macromonomer). Examples of the acrylic oligomer segment include methyl methacrylate, butyl acrylate, and isobutyl acrylate. From the viewpoint of solubility, the number average molecular weight is preferably 10,000 or less (the number average molecular weight is measured by GPC and converted to standard polystyrene).

  The epoxy curing agent (D) used in the present invention is not particularly limited, but is an acid anhydride which is liquid at 25 ° C., for example, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hydrogen Methyl nadic acid anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, and the like. Among them, alicyclic acid anhydride is preferable, and methylhexahydrophthalic anhydride and hydrogenated methyl nadic acid anhydride are particularly preferable. .

  As the radical polymerization initiator (E) 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 carried out by radical photopolymerization, a radical photopolymerization initiator (E) is used instead of radical thermal polymerization initiators such as the above-mentioned azo initiators and peroxide initiators. Can be used. 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.

  Although it does not specifically limit as an epoxy hardening accelerator (F) used by this invention, For example, quaternary phosphonium salt type | system | group, quaternary ammonium salt type | system | group, imidazole type | system | group, DBU (1,8-diaza-bicyclo- (5,4) , 0) -undecene-7) fatty acid salt system, metal salt system, triphenylphosphine system and the like. Examples of the quaternary phosphonium salt system include tetrabutylphosphonium diethylphosphodithionate, tetraphenylphosphonium bromide, and tetrabutylphosphonium bromide. Examples of the quaternary ammonium salt system include tetraethylammonium bromide and tetrabutylammonium bromide are imidazole. Examples of the system include 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, 2,4-diamino-6- [2-methylimidazolyl- ( 1)] Ethyl-s-triazine, 2-phenylimidazoline, etc., DBU fatty acid salt system is DBU 2-ethylhexanoate, and metal salt system is zinc octylate, tin octylate, etc. .

  The crosslinked structure of the cured product depends on the relationship between the half-life temperature of the radical polymerization initiator (E) used and the gelation temperature of the epoxy curing accelerator (F). Generally, since 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) acrylate proceeds and (meth) acryl main chain and (meth) acryl side chain Then, ionic polymerization of epoxy group and acid anhydride proceeds, and 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, it is considered that a denser cross-linked structure can be obtained without steric constraints on the acrylic main chain. It is done.

  It is preferable to mix | blend the compounding quantity of (A) component and (B) component in this invention so that it may become (A) :( B) = 30: 70-95: 5 by weight ratio, 50: 50-90 : It is particularly preferable to blend so as to be 10. Here, if the ratio of the component (A) is less than 30, the crosslink density becomes too small, and the heat resistance is lowered. On the other hand, when the ratio of the component (A) exceeds 95 and the crosslinking density becomes too high, the elastic modulus is large and the brittleness tends to be brittle.

  The compounding quantity of (C) component in this invention is the weight ratio of the said (C) component, (A) component, and (B) component (C) :( A) + (B) = 10: 90-50 : It is preferable to mix | blend so that it may be set to 50, and it is especially preferable to mix | blend so that it may become 20: 80-40: 60. Here, if the ratio of the component (C) is less than 10, the effect of reducing curing shrinkage is small. On the other hand, when the ratio of the component (C) is greater than 50, dissolution in the component (A), the component (B), and the component (D) tends to be difficult.

  The compounding amount of the epoxy curing agent (D) component in the present invention is 0.5 to 1.2 in terms of an equivalent ratio (acid anhydride group / epoxy group) between the acid anhydride group and the epoxy group of the component (A). It is preferable that When this equivalent ratio is larger than 1.2, the cured product is easily colored by heat or ultraviolet rays. On the other hand, if the equivalent ratio is less than 0.5, the heat resistance tends to decrease.

  The blending amount of the radical polymerization initiator (E) component in the present invention is 0.01 to 5 weights with respect to 100 parts by weight of the total amount of the components (A), (B), components (C) and (D). Parts, preferably 0.1 to 1 part by weight. If this amount exceeds 5 parts by weight, the cured product tends to be colored by heat or ultraviolet rays, and if it is less than 0.01 part by weight, it tends to be difficult to cure.

  The compounding amount of the epoxy curing accelerator (F) component in the present invention is 0.01 to 5 weights with respect to 100 parts by weight of the total amount of component (A), component (B), component (C) and component (D). Parts, preferably 0.1 to 1 part by weight. If this amount exceeds 5 parts by weight, the cured product tends to be colored by heat or ultraviolet rays, and if it is less than 0.01 part by weight, it tends to be difficult to cure.

  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.

The method for producing an optical member using the resin composition of the present invention comprises an epoxy group-containing (meth) acrylate as the monomer component (A), (meth) acrylate as the monomer component (B), and a polymerization-reactive acrylic as the component (C). Resin composition that is liquid at 25 ° C. (room temperature), which contains an acid anhydride as an oligomer and an epoxy curing agent (D), and may further optionally include a radical polymerization initiator (E) and an epoxy curing accelerator (F) The product is cured by heating or light irradiation to cause both radical polymerization of (A), (B) and (C) and ionic polymerization of the components (A) and (D) to proceed. As the form of the resin composition, (A) component, (B) component, (C) component and (D) component, resin solution prepared by mixing (E) component and (F) component added as necessary However, it is divided into the first liquid containing the component (A), the component (B) and the component (C), and the second liquid containing the component (D), the component (E) and the component (F). Thus, the storage stability of each can be improved, and the resin composition of the present invention can be obtained by mixing the first liquid and the second liquid at the time of use.

  In the method for producing an optical member using the resin composition of the present invention, the resin solution is poured into a desired portion, cast, potted, or poured into a mold and cured by heating or light. 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 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 60 to 150 ° C. and about 1 to 5 hours. Further, in order to reduce internal stress generated by a rapid curing reaction, it is desirable to raise the curing temperature stepwise. Further, in order to easily obtain a cured product in a shorter time, first, photoradical polymerization of the component (A), the component (B) and the component (C) is performed by light irradiation, and then heated (A) It is also possible to perform ion polymerization of the component and the component (D).

The resin composition of the present invention described above is a resin composition having high optical transparency of the cured product, excellent heat resistance, light resistance, mechanical properties, and small curing shrinkage, and the cured product is transparent. It is suitable as an optical member for use in optical semiconductor elements such as substrates, lenses, adhesives, optical waveguides, light emitting diodes (LEDs), phototransistors, photodiodes, and solid-state imaging devices.

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

Example 1
32 parts by weight of glycidyl methacrylate (light ester G, manufactured by Kyoeisha Chemical Co., Ltd.) as an epoxy group-containing (meth) acrylate of the monomer component (A), methyl methacrylate (Wako Pure Chemical Industries, Ltd.) as the (meth) acrylate of the monomer component (B) Acrylic reactive oligomer (AA6, Toa Gosei Co., Ltd.) having a number average molecular weight of 6,000, having 16 parts by weight, a component (C), a polymerization reactive acrylic oligomer having a methacryloyl group at one end and methyl methacrylate as the main chain segment 16 parts by weight), 36 parts by weight of methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.) as the acid anhydride of the epoxy curing agent (D), as the radical polymerization initiator (E) 0.2 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) Epoxy curing accelerator (F) as tetrabutylphosphonium diethyl phosphonate dithionate the (Hishicolin PX-4ET, manufactured by Nippon Chemical Industrial Co., Ltd.) 1 part by weight were mixed at room temperature (25 ° C.), to prepare a resin composition solution. This resin solution is poured into a mold in which a 3 mm thick and 1 mm thick silicone spacer is sandwiched between glass plates, and heated in an oven at 80 ° C., 100 ° C., 125 ° C. and 150 ° C. for 1 hour each. Then, cured products having thicknesses of 3 mm and 1 mm were obtained.

(Example 2)
To 32 parts by weight of glycidyl methacrylate (Light Ester G, manufactured by Kyoeisha Chemical Co., Ltd.), 16 parts by weight of 1,9-nonanediol acrylate (Light acrylate 1,9-ND-A manufactured by Kyoeisha Chemical Co., Ltd.), one end is a methacryloyl group 16 parts by weight of an acrylic reactive oligomer (AA6, manufactured by Toa Gosei Co., Ltd.) having a number average molecular weight of 6,000 whose main chain segment is methyl methacrylate, methylhexahydrophthalic anhydride (HN-5500, Hitachi Chemical Co., Ltd.) 36 parts by weight, Azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) 0.2 parts by weight, Tetrabutylphosphonium diethylphosphodithionate (Hishicolin PX-4ET, Nippon Chemical Industry Co., Ltd.) 1 part by weight Were mixed at room temperature (25 ° C.) to prepare a resin composition solution. Using this resin solution, cured products having thicknesses of 3 mm and 1 mm were obtained in the same manner as in Example 1.

(Example 3)
Glycidyl methacrylate (light ester G, manufactured by Kyoeisha Chemical Co., Ltd.) 32 parts by weight, ethoxylated isocyanuric acid triacrylate (NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.) 16 parts by weight, one end is mainly methacryloyl group Acrylic-reactive oligomer (AA6, manufactured by Toa Gosei Co., Ltd.) having a number average molecular weight of 6,000 whose chain segment is methyl methacrylate, 16 parts by weight, methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.) 36 parts by weight, 0.2 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.), 1 part by weight of tetrabutylphosphonium diethylphosphodithionate (Hishicolin PX-4ET, manufactured by Nippon Chemical Industry Co., Ltd.) at room temperature (25 ° C.) to prepare a resin composition solution. Using this resin solution, cured products having a thickness of 3 mm and 1 mm were obtained in the same manner as in Example 1.

Example 4
35 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate (Cyclomer M100, manufactured by Daicel Chemical Industries), 25 parts by weight of methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), one end is a methacryloyl group and the main chain segment is methyl 11 parts by weight of an acrylic reactive oligomer having a number average molecular weight of 6,000 (AA6, manufactured by Toa Gosei Co., Ltd.), 29 parts by weight of methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.), 0.2 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) and 1 part by weight of tetrabutylphosphonium diethylphosphodithionate (Hishicolin PX-4ET, manufactured by Nippon Chemical Industry Co., Ltd.) at room temperature (25 ° C.) To prepare a resin composition solution. Using this resin solution, cured products having a thickness of 3 mm and 1 mm were obtained in the same manner as in Example 1.

(Example 5)
The number average molecular weight of glycidyl methacrylate (light ester G, manufactured by Kyoeisha Chemical Co., Ltd.) 32 parts by weight and methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 22 parts by weight, one end having a methacryloyl group and the main chain segment being methyl methacrylate 9 parts by weight of 6,000 acrylic reactive oligomer (AA6, manufactured by Toa Gosei Co., Ltd.), 36 parts by weight of methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.), 1 as a radical photopolymerization initiator -1 part by weight of hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals), 1 part by weight of tetrabutylphosphonium diethylphosphodithionate (Hishicolin PX-4ET, manufactured by Nippon Chemical Industry Co., Ltd.) at room temperature (25 ° C) ) Things solution was adjusted. The resin solution, poured a 3mm Atsuoyobi 1mm thick silicone spacer in a mold sandwiched by glass plates, radicals integrated exposure amount 3000 mJ / cm ² illuminance 11.6 mW / cm ² using an extra-high pressure mercury lamp Polymerized. Furthermore, it heated on 100 degreeC, 125 degreeC, and 150 degreeC on the conditions for 1 hour each, and the hardened | cured material of 3 mm thickness and 1 mm thickness was obtained.

(Comparative Example 1)
100 parts by weight of methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.2 part by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) are mixed at room temperature (25 ° C.) to obtain a resin composition solution. Adjusted. 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 6 hours and 110 ° C. for 1 hour to cure to 3 mm and 1 mm thickness. I got a thing.

(Comparative Example 2)
42 parts by weight of glycidyl methacrylate (light ester G, manufactured by Kyoeisha Chemical Co., Ltd.), 10 parts by weight of methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), methyl hexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.) ) 48 parts by weight, 0.2 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.), 1 part by weight of tetrabutylphosphonium diethylphosphodithionate (Hishicolin PX-4ET, manufactured by Nippon Chemical Industry Co., Ltd.) The mixture was mixed at room temperature (25 ° C.) to prepare a resin composition solution. Using this resin solution, cured products having a thickness of 3 mm and 1 mm were obtained in the same manner as in Example 1.

  The formulations of Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 1.

  Here, the numbers in Table 1 are parts by weight, A1: glycidyl methacrylate, A2: 3,4-epoxycyclohexylmethyl methacrylate, B1: methyl methacrylate, B2: 1,9-nonanediol diacrylate, B3: ethoxylated isocyanur. Acid triacrylate, C1: Acrylic reactive oligomer having a number average molecular weight of 6,000 having a methacryloyl group at one end and a main chain segment of methyl methacrylate, D1: methylhexahydrophthalic anhydride, E1: azobisisobutyronitrile , F1: tetrabutylphosphonium diethylphosphodithionate, G1: 1-hydroxycyclohexyl phenyl ketone.

  About the hardened | cured material obtained in the said Examples 1-5 and the comparative examples 1 and 2, hardening shrinkage rate, glass transition temperature, bending strength, light transmittance, and yellowing degree were measured by the method shown below.

  The cure shrinkage (ΔV) was calculated from the specific gravity (ρm) of the resin composition and the specific gravity (ρp) of the cured product using the following formula (1).

  The glass transition temperature (Tg) was measured using a differential thermomechanical analyzer (TAS100 model manufactured by Rigak) by cutting a 3 × 3 × 20 mm test piece from a cured product having a thickness of 3 mm. 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.

  The bending strength was determined by cutting a 3 × 20 × 50 mm test piece and performing a bending test with a three-point support according to JIS-K-6911 using a three-point bending test apparatus (Instron 5548 type). The bending strength was calculated from 2). The distance between fulcrums was 24 mm, the crosshead moving speed was 0.5 mm / min, the measurement temperature was 25 ° C. (room temperature), and 250 ° C., which is close to the reflow temperature when mounting a semiconductor package.

（式（２）中、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。）

(In formula (2), σfB: bending strength (MPa), P ′: weight (N) when the test piece is bent, L: distance between fulcrums, W: width of test piece, h: test piece Is the thickness of.)

  The light transmittance and the yellowing degree were measured with a 1 mm-thick test piece using a spectrophotometer (Hitachi spectrophotometer V-3310). The light transmittance was measured after curing (initial stage) and after standing at high temperature for 72 hours at 150 ° C. as an evaluation of heat discoloration. 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 Examples 1 to 5 and Comparative Examples 1 and 2, that is, curing shrinkage, glass transition temperature, room temperature (25 ° C.) and bending strength at 250 ° C., optical properties, that is, after curing (initial) and left at high temperature The light transmittance and yellowing degree at 400 nm later are shown in Table 2.

In each of Examples 1 to 5, the curing shrinkage rate is 10% or less, which is smaller than those of Comparative Examples 1 and 2, and the bending strength at high temperature is as large as 3 MPa or more. Furthermore, it can be seen that the optical characteristics have high initial transmittance, small yellowing, little decrease in transmittance after standing at high temperature, and small change in yellowing. On the other hand, when the acrylate monomer content is large as in Comparative Examples 1 and 2, the curing shrinkage is large.

Claims (7)

  Contains epoxy group-containing (meth) acrylate as monomer component (A), (meth) acrylate as monomer component (B), polymerization-reactive acrylic oligomer as component (C), and acid anhydride as epoxy curing agent (D) A resin composition that is liquid at 25 ° C. and is cured by heating or light irradiation.   The resin composition according to claim 1, further comprising a radical polymerization initiator (E) and an epoxy curing accelerator (F).   The resin composition according to claim 1 or 2, wherein the polymerization reactive acrylic oligomer of the component (C) is an acrylic oligomer (macromonomer) having a (meth) acryloyl group terminal.   Radical polymerization of the monomer component (A), the monomer component (B) and the component (C) and ionic polymerization of the monomer component (A) and the epoxy curing agent (D) proceed by heating or light irradiation. The resin composition according to any one of claims 1 to 3.   The monomer component (A), the first component containing the monomer component (B) and the component (C), the epoxy curing agent (D), the radical polymerization initiator (E) and the epoxy curing accelerator. The resin composition according to any one of claims 2 to 4, which is obtained by mixing a second liquid containing (F) and cured by heating or light irradiation.   The optical member produced by hardening | curing the resin composition in any one of Claims 1-5. Using the resin composition according to any one of claims 1 to 5, radical polymerization of the monomer component (A), the monomer component (B) and the component (C) is performed by light irradiation, and the monomer component (A) and the epoxy The manufacturing method of the optical member which performs ion polymerization of a hardening | curing agent (D) by subsequent heating.