WO2011102288A1

WO2011102288A1 - Curable composition and cured material

Info

Publication number: WO2011102288A1
Application number: PCT/JP2011/052830
Authority: WO
Inventors: 久保隆司; 藤川武
Original assignee: ダイセル化学工業株式会社
Priority date: 2010-02-16
Filing date: 2011-02-10
Publication date: 2011-08-25
Also published as: TW201144351A

Abstract

Disclosed is a curable composition which can be used to produce a cured resin with a low Abbe number, a high light transmission index and a high refractive index with optical and physical characteristics resistant to change even under high temperature conditions. The curable composition contains an epoxy compound with aromatic rings (A), a (meth)acryl ester (B) with aromatic rings and a (meth)acryl ester (C) with an epoxy group in one molecule. As the (meth)acryl ester (C) with an epoxy group in one molecule, one compound selected from a (meth)acryl ester containing an alicyclic epoxy group and a (meth)acryl ester containing a glycidyl group can be used.

Description

Curable composition and cured product

The present invention relates to a curable composition, a cured product thereof, and an optical member. More specifically, a curable composition that can form a cured product that is excellent in optical properties and physical properties and does not deteriorate even at high temperatures, a cured resin that is obtained by curing the curable composition, and The present invention relates to an optical member such as a lens made of the cured resin.

Curable compositions are used as plastic materials in machine part materials, electrical / electronic parts materials, automotive parts materials, civil engineering and building materials, molding materials, paints, adhesives, sealing materials, etc. It is also attracting attention as a material for these optical members.

As an example of using a curable composition as a plastic lens material, a plastic lens material mainly composed of a (meth) acrylic acid ester having a fluorene skeleton is known (Patent Document 1). In this plastic lens material, since the (meth) acrylic acid ester having a fluorene skeleton has a high viscosity, the viscosity is lowered by adding a vinyl compound having an alkylene oxide group to the main chain or a monofunctional radically polymerizable monomer. To produce a molded body. However, such a composition has a problem that the refractive index fluctuates or decreases. Moreover, there also existed a problem that cure shrinkage was large and the moisture absorption rate was also high.

Patent Document 2 discloses a (meth) acrylic acid ester having an aromatic ring and a cationically polymerizable compound in order to solve the problems of the cured composition mainly composed of (meth) acrylic acid ester having an aromatic ring as described above. A curable composition using a combination thereof is proposed. According to this composition, improvement in the curing rate, improvement in workability by lowering the viscosity, suppression of curing shrinkage of the cured product, and maintenance of a high refractive index are achieved to some extent. The plastic lens obtained from this composition is used as a low Abbe number lens having an Abbe number of 40 or less. However, the plastic lens obtained by curing this composition cannot be said to have sufficient heat resistance, and the shape changes at a high temperature and the light transmittance is significantly reduced. Therefore, for example, camera-equipped mobile phones and the like are manufactured through a reflow soldering process (mounting process), but cannot withstand the process temperature (about 260 ° C.), and thus are manufactured separately after the soldering process. A process of connecting the camera module with a connector is required.

Japanese Patent No. 3130555 JP 2009-235196 A

An object of the present invention is a low Abbe number curable resin having an Abbe number of 35 or less having a high light transmittance and a refractive index, and having a characteristic that optical properties and physical properties hardly change even under high temperature conditions (hereinafter referred to as “abbe number”). The present invention provides a curable composition capable of obtaining “a low Abbe number curable resin having an Abbe number of 35 or less” (sometimes simply referred to as “low Abbe number curable resin”).

Another object of the present invention is to provide a low Abbe number cured resin having characteristics that optical characteristics and physical characteristics are hardly changed even under high temperature conditions such as soldering by a reflow method, and an optical member made of the cured resin. There is to do.

As a result of intensive studies to achieve the above object, the present inventors have found that an epoxy compound having a specific structure, a (meth) acrylic acid ester having a specific structure, and a (meth) acrylic acid ester having an alicyclic epoxy group having a specific structure. Curing a curable composition containing a low Abbe number having a high light transmittance and refractive index and a property that optical properties and physical properties are difficult to change even under high temperature conditions of about 260 ° C., for example. The inventors found that a resin can be obtained and completed the present invention.

That is, the present invention comprises an epoxy compound (A) having an aromatic ring, a (meth) acrylic acid ester (B) having an aromatic ring, and a (meth) acrylic acid ester (C) having an epoxy group in the molecule. A curable composition is provided.

As the (meth) acrylic acid ester (C) having an epoxy group in the molecule, at least one selected from a (meth) acrylic acid ester having an alicyclic epoxy group and a (meth) acrylic acid ester having a glycidyl group Can be used.

Moreover, as (meth) acrylic acid ester (C) which has an epoxy group in a molecule | numerator, following formula (1)

(Wherein R ^a represents a hydrogen atom or a methyl group, Y ^a represents a single bond, an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 or 2 or more carbon atoms and 1 or 2 or more) oxygen atom (-O-) and represents the bound group, ring Z ^a represents an alicyclic epoxy group)
The (meth) acrylic acid ester which has an alicyclic epoxy group represented by these can be used.

Alicyclic epoxy group in the ring Z ^a is represented by the following formula (a)

The group represented by these may be sufficient.

As the epoxy compound (A) having an aromatic ring, at least one aromatic ring selected from the group consisting of a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring and a carbazole ring is used. The epoxy compound which has can be used.

The (meth) acrylic acid ester (B) having an aromatic ring is at least one selected from the group consisting of a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring, and a carbazole ring. (Meth) acrylic acid ester having the following aromatic ring can be used.

The present invention also provides a curable resin obtained by curing the curable composition.

The present invention further provides an optical member made of the cured resin.

According to the curable composition of the present invention, by curing, it has high light transmittance and refractive index, and optical properties (light transmittance, refractive index, Abbe number, etc.) A cured resin having a low Abbe number having a characteristic that physical characteristics hardly change can be obtained. Such a cured resin is not easily yellowed even when subjected to a soldering process by a reflow method, and is not easily changed in shape, so that it can be used for an optical member such as a lens. For example, when the lens made of the cured resin of the present invention is used as a lens for a camera-equipped mobile phone, the camera module can be mounted at the same time in the reflow soldering process (mounting process), which is performed after the soldering process. The connecting step of the camera module with the existing connector can be omitted.

The curable composition of the present invention comprises an epoxy compound (A) having an aromatic ring, a (meth) acrylic acid ester (B) having an aromatic ring, and a (meth) acrylic acid ester (C) having an epoxy group in the molecule. ).

In the present invention, an epoxy compound having an aromatic ring which is a cationic polymerizable compound (cation curable compound) and a (meth) acrylic acid ester having an aromatic ring which is a radical polymerizable compound (radical curable compound) are combined. Therefore, by curing, a low Abbe number cured resin having high transmittance and refractive index is obtained. In addition, this cured resin has high strength and superior solvent resistance compared to a cured product obtained only from a cationic polymerizable compound, and cured compared to a cured product obtained only from a radical polymerizable compound. It has the advantage of low shrinkage and hygroscopicity. In the present invention, in addition to these polymerizable compounds, a polymerizable compound having an epoxy group as a cationic polymerizable group and a (meth) acryloyloxy group as a radical polymerizable group in the molecule is added. This polymerizable compound acts as a cross-linking agent between a cationic curable resin and a radical curable resin, and the heat resistance of the cured resin is remarkably improved. Optical properties (light transmittance, refractive index, Abbe number, etc.) and physical properties even at high temperatures It is possible to obtain a cured resin that hardly changes. In particular, an alicyclic epoxy group [particularly, 3,4-epoxytricyclo [5.2.1.0] decane 8 represented by the formula (a) is present in the molecule represented by the formula (1). When a compound having — (or 9) yl group] is used, the heat resistance of the cured resin is remarkably improved, and the moisture absorption rate, the thermal elastic modulus, and the linear expansion coefficient can be reduced. Moreover, melt viscosity and a dielectric constant can be reduced, and a softening point, mechanical strength, and adhesiveness can be improved.

[Epoxy compound having an aromatic ring (A)]
In the epoxy compound (A) having an aromatic ring, examples of the aromatic ring include a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring, and a carbazole ring. The aromatic ring is preferably one containing at least an aromatic carbocyclic ring. Moreover, as an epoxy compound (A) which has an aromatic ring, the polyfunctional epoxy compound which has 2 or more of epoxy groups in a molecule | numerator is preferable.

As a representative example of the epoxy compound (A) having an aromatic ring, for example, an epibis type glycidyl ether type epoxy obtained by a condensation reaction of bisphenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol and epihalohydrin Resin; High molecular weight epibis type glycidyl ether type epoxy resin obtained by further addition reaction of these epibis type glycidyl ether type epoxy resins with bisphenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc .; phenol , Cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, bisphenol S and other phenols and formaldehyde, aceto A novolak alkyl type glycidyl ether type epoxy resin obtained by condensation reaction of polyhydric phenols obtained by condensation reaction of aldehydes such as aldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde and the like with epihalohydrin; 9 of fluorene ring An epoxy compound in which two phenol skeletons are bonded to each other and a glycidyl group is bonded to a hydroxyl group of the two phenol skeletons directly or via an alkyleneoxy group [an epoxy compound having a bisarylfluorene skeleton] Etc.

Preferred examples of the epoxy compound (A) having an aromatic ring include compounds represented by the following formulas (A-1), (A-2), and (A-3).

In the above formulas, R ¹ and R ² are the same or different and each represents an alkylene group, the ring Z ¹ and ring Z ² are the same or different and represent an aromatic carbocycle, and k1 and k2 are the same or different. 0 or an integer of 1 or more, and m1 and m2 are the same or different and represent an integer of 0 or 1 or more. However, m1 + m2 is 1 or more. In the formula (A1-3), the fluorene ring, ring Z ¹ , and ring Z ² may have a substituent.

Examples of the alkylene group in R ¹ and R ² include linear or branched alkylene groups having 1 to 10 carbon atoms such as methylene, ethylene, propylene, trimethylene, tetramethylene and hexamethylene groups. Preferred alkylene groups include alkylene groups having 2 to 6 carbon atoms (particularly alkylene groups having 2 to 3 carbon atoms) such as ethylene, propylene and trimethylene groups.

Examples of the aromatic carbocycle in the ring Z ¹ and the ring Z ² include about 1 to 4 aromatic carbocycles such as a benzene ring, a naphthalene ring, and an anthracene ring. Preferred aromatic carbocycles include benzene rings, naphthalene rings and the like.

K1 and k2 are each 0 or an integer of 1 or more, preferably 0 or an integer of 1 to 10, more preferably 0 or an integer of 1 to 4. m1 and m2 are each 0 or an integer of 1 or more, preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

In the formula (A-3), examples of the substituent that the fluorene ring, ring Z ¹ , and ring Z ² may have include, for example, alkyl groups such as methyl, ethyl, propyl, and isopropyl groups (for example, C _{1- 6} alkyl groups, preferably methyl groups); cycloalkyl groups such as cyclopentyl and cyclohexyl groups (for example, C _5-8 cycloalkyl groups); aryl groups such as phenyl and naphthyl groups (for example, C _6-15 aryl groups); Aralkyl groups such as benzyl groups (eg C _7-16 aralkyl groups); Acyl groups such as acetyl, propionyl and benzoyl groups (eg C _1-10 acyl groups); methoxy, ethoxy, propyloxy, isopropyloxy groups, etc. an alkoxy group (e.g., C _1-6 alkoxy group); methoxycarbonyl, alkoxycarbonyl groups such as ethoxycarbonyl group (e.g., C _1-4 alkoxy Carbonyl group), cyano groups, carboxyl groups, nitro groups, amino group, substituted amino group (e.g., di-C _1-4 alkylamino group, etc.); fluorine atom, a halogen atom such as a chlorine atom.

The ratio of the epoxy compound (A) having an aromatic ring in the curable composition of the present invention varies depending on the use of the cured resin, etc., but for the entire curable composition (or the total amount of the curable compound), for example, It is about 10 to 70% by weight, preferably about 20 to 60% by weight, and more preferably about 30 to 50% by weight. If the amount of the epoxy compound (A) having an aromatic ring is too small, curing shrinkage that is a problem in terms of moldability is increased, and problems such as increased hygroscopicity and reduced moisture resistance are likely to occur. Moreover, when there is too much quantity of the epoxy compound (A) which has an aromatic ring, the variation | change_quantity of the optical characteristic under high temperature, such as the reflow conditions mentioned later, will become large, and a problem will be easy to arise in the point of heat resistance.

[(Meth) acrylic acid ester having aromatic ring (B)]
In the (meth) acrylic acid ester (B) having an aromatic ring, examples of the aromatic ring include a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring, and a carbazole ring. . The aromatic ring is preferably one containing at least an aromatic carbocyclic ring. The (meth) acrylic acid ester (B) having an aromatic ring is preferably a compound having a conjugated structure composed of 7 or more carbon atoms. According to such a compound, a cured resin having a high refractive index can be obtained by curing. Further, the (meth) acrylic acid ester (B) having an aromatic ring is preferably a polyfunctional (meth) acrylate having two or more (meth) acryloyloxy groups in the molecule.

The (meth) acrylic acid ester (B) having an aromatic ring is more preferably an acrylic acid ester having an aromatic ring. When the radical polymerization rates of the monomer having an acryloyloxy group and the monomer having a methacryloyloxy group are compared, the former is slower. On the other hand, when comparing the reaction rate of radical polymerization with the reaction rate of cationic polymerization, radical polymerization is generally faster. In a system in which radical polymerization and cationic polymerization proceed in parallel as in the present invention, it is preferable that radical polymerization and cationic polymerization proceed as evenly as possible from the viewpoint of physical properties of the cured resin. If radical polymerization proceeds first, the cure shrinkage of the resulting cured resin increases, and many unreacted cationic polymerizable groups remain even after completion of radical polymerization. Reaction and decomposition may occur, and physical properties of the cured resin may be impaired. For this reason, as the (meth) acrylic acid ester (B) having an aromatic ring, an acrylic acid ester having an aromatic ring is more preferable.

In the (meth) acrylic acid ester (B) having an aromatic ring, the aromatic ring and the (meth) acryloyloxy group may be directly bonded or may be bonded via a linking group. Examples of the linking group include a divalent hydrocarbon group, a carbonyl group (—CO—), an ether bond (—O—), an ester bond (—COO—), an amide bond (—CONH—), a carbonate bond (— OCOO-) and a group in which a plurality of these are bonded. Examples of the divalent hydrocarbon group include linear or branched alkylene groups such as methylene, ethylidene, isopropylidene, ethylene, propylene, trimethylene, and tetramethylene groups (for example, C _1-6 alkylene groups); Divalent groups such as 2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene groups And alicyclic hydrocarbon groups (particularly divalent cycloalkylene groups); groups in which a plurality of these are bonded.

Representative examples of the (meth) acrylic acid ester (B) having an aromatic ring include, for example, (meth) acrylic acid esters of bisphenols such as bisphenol A, bisphenol F, bisphenol S, and fluorene bisphenol; ethylene oxide of the bisphenols And / or (meth) acrylic acid ester of an adduct of propylene oxide; two phenol skeletons are bonded to the 9-position of the fluorene ring, and the hydroxyl groups of the two phenol skeletons are directly or via an alkyleneoxy group, respectively. (Meth) acrylic acid ester ((meth) acrylic acid ester having a bisarylfluorene skeleton) to which a (meth) acryloyloxy group is bonded; to two hydroxyl groups of biphenol, either directly or via an alkyleneoxy group The Meth) acrylate such as acryloyloxy group is bonded (meth) acrylic acid esters.

Preferred examples of the (meth) acrylic acid ester (B) having an aromatic ring include compounds represented by the following formulas (B-1) and (B-2).

In the above formula, R ⁴ and R ⁵ are the same or different and represent a hydrogen atom or a methyl group, R ⁶ and R ⁷ are the same or different and represent an alkylene group, and ring Z ³ and ring Z ⁴ are It is the same or different and represents an aromatic carbocycle, r1 and r2 are the same or different and represent 0 or an integer of 1 or more, and s1 and s2 are the same or different and represent 0 or an integer of 1 or more. However, s1 + s2 is 1 or more. In the formula (B-1), the fluorene ring, ring Z ³ , and ring Z ⁴ may have a substituent.

Examples of the alkylene group in R ⁶ and R ⁷ include linear or branched alkylene groups having 1 to 10 carbon atoms such as methylene, ethylene, propylene, trimethylene, tetramethylene and hexamethylene groups. Preferred alkylene groups include alkylene groups having 2 to 6 carbon atoms (particularly alkylene groups having 2 to 3 carbon atoms) such as ethylene, propylene and trimethylene groups.

Examples of the aromatic carbocycle in the ring Z ³ and the ring Z ⁴ include about 1 to 4 aromatic carbocycles such as a benzene ring, a naphthalene ring, and an anthracene ring. Preferred aromatic carbocycles include benzene rings, naphthalene rings and the like.

R1 and r2 are each 0 or an integer of 1 or more, preferably 0 or an integer of 1 to 10, more preferably 0 or an integer of 1 to 4. Each of s1 and s2 is 0 or an integer of 1 or more, preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

In the formula (B-1), examples of the substituent that the fluorene ring, ring Z ³ , and ring Z ⁴ may have include, for example, alkyl groups such as methyl, ethyl, propyl, and isopropyl groups (for example, C _{1- 6} alkyl groups, preferably methyl groups); cycloalkyl groups such as cyclopentyl and cyclohexyl groups (for example, C _5-8 cycloalkyl groups); aryl groups such as phenyl and naphthyl groups (for example, C _6-15 aryl groups); Aralkyl groups such as benzyl groups (eg C _7-16 aralkyl groups); Acyl groups such as acetyl, propionyl and benzoyl groups (eg C _1-10 acyl groups); methoxy, ethoxy, propyloxy, isopropyloxy groups, etc. an alkoxy group (e.g., C _1-6 alkoxy group); methoxycarbonyl, alkoxycarbonyl groups such as ethoxycarbonyl group (e.g., C _1-4 alkoxy Carbonyl group), cyano groups, carboxyl groups, nitro groups, amino group, substituted amino group (e.g., di-C _1-4 alkylamino group, etc.); fluorine atom, a halogen atom such as a chlorine atom.

The ratio of the (meth) acrylic acid ester (B) having an aromatic ring in the curable composition of the present invention varies depending on the use of the curable resin, but the entire curable composition (or the total amount of the curable compound). On the other hand, it is, for example, about 10 to 70% by weight, preferably about 20 to 60% by weight, and more preferably about 30 to 50% by weight. If the amount of the (meth) acrylic acid ester (B) having an aromatic ring is too small, the amount of change in optical properties at high temperatures such as reflow conditions described later becomes large, and problems are likely to occur in terms of heat resistance. Moreover, when there is too much quantity of the (meth) acrylic acid ester (B) which has an aromatic ring, while the shrinkage | hardening shrinkage which becomes a problem by the point of a moldability becomes large, moisture absorption becomes large and moisture resistance falls. Is likely to occur.

[(Meth) acrylic acid ester having epoxy group in molecule (C)]
The (meth) acrylic acid ester (C) having an epoxy group in the molecule is not particularly limited as long as it is a compound having an epoxy group and a (meth) acryloyloxy group in the molecule. The (meth) acrylic acid ester (C) having an epoxy group in the molecule can be used alone or in combination of two or more.

The (meth) acrylic acid ester (C) having an epoxy group in the molecule is the same as the case of the (meth) acrylic acid ester (B) having an aromatic ring (radical polymerization and cationic polymerization are made as evenly as possible. From the reason that it proceeds, an acrylic ester having an epoxy group in the molecule is more preferable.

Examples of (meth) acrylic acid ester (C) having an epoxy group in the molecule include (i) (meth) acrylic acid ester having alicyclic epoxy group, (ii) (meth) acrylic acid ester having glycidyl group, etc. Is mentioned. The alicyclic epoxy group is not particularly limited as long as it is an epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting the alicyclic ring. Examples of the alicyclic ring include monocyclic alicyclic rings such as cyclopentane ring, cyclohexane ring, cyclooctane ring and cyclododecane ring (3 to 15 member, preferably about 5 to 6 membered cycloalkane ring); decalin ring (Perhydronaphthalene ring), perhydroindene ring (bicyclo [4.3.0] nonane ring), perhydroanthracene ring, perhydrofluorene ring, perhydrophenanthrene ring, perhydroacenaphthene ring, perhydrophenalene ring , Norbornane ring (bicyclo [2.2.1] heptane ring), isobornane ring, adamantane ring, bicyclo [3.3.0] octane ring, tricyclo [5.2.1.0 ^2,6 ] decane ring, tricyclo [6.2.1.0 ^2,7 ] Polycyclic (about 2 to 4 rings) alicyclic ring (bridged carbon ring) such as undecane ring. Examples of the alicyclic epoxy group include an epoxycyclopentyl group, a 3,4-epoxycyclohexyl group, and a 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decane represented by the following formula (a). An 8- (or 9) yl group and the like can be mentioned. The alicyclic epoxy group includes a bridged carbocyclic ring such as a 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decane 8- (or 9) yl group represented by the formula (a). And an alicyclic epoxy group composed of an epoxy group composed of two adjacent carbon atoms and an oxygen atom constituting the bridged carbon ring.

Examples of the (meth) acrylic acid ester (i) having the alicyclic epoxy group include a compound represented by the following formula (1). Moreover, the compound represented by following formula (2) is illustrated as (meth) acrylic acid ester (ii) which has a glycidyl group.

In the above formula, R ^a represents a hydrogen atom or a methyl group, and Y ^a is a single bond, an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 or 2 or more carbon atoms and 1 or 2 or more. It shows the oxygen atom (-O-) and is bonded group, ring Z ^a represents an alicyclic epoxy group. Examples of the alkylene group having 1 to 10 carbon atoms for Y ^a include linear or branched alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, and hexamethylene groups.

The Y ^a, in particular, a single bond, an alkylene group having 1 to 6 carbon atoms, an alkyleneoxy group (an oxygen atom rightmost) having 1 to 6 carbon atoms, plurality alkyleneoxy group having 1 to 6 carbon atoms (e.g., It is preferably a bonded polyalkyleneoxy group (terminal oxygen atom is at the right end).

More specific examples of the compound represented by the formula (1) include the following compounds (1-1), (1-2), and (1-3).

In the above formula, R ^a and Y ^a are the same as described above.

More specific examples of the (meth) acrylic acid ester (ii) having a glycidyl group include glycidyl (meth) acrylate.

The ratio of the (meth) acrylic acid ester (C) having an epoxy group in the molecule in the curable composition of the present invention is, for example, 1 to 1 with respect to the entire curable composition (or the total amount of the curable compound). It is about 50% by weight, preferably about 5 to 40% by weight, and more preferably about 10 to 30% by weight. When the amount of the (meth) acrylic acid ester (C) having an epoxy group in the molecule is within the above range, the above (C) is maintained while maintaining the merits of the respective cured resins of the cationic cured resin and the radical cured resin. The heat resistance of the cured resin can be further improved by the action of the component as a crosslinking agent.

[Other ingredients]
The curable composition of the present invention is a curable compound (cationic polymerizable compound, radical) other than the components (A), (B), and (C) as long as the optical properties and physical properties of the cured resin are not impaired. A polymerizable compound, etc.). The curable composition of the present invention contains a cationic polymerization initiator, a curing agent, a curing accelerator, a radical polymerization initiator, a photosensitizer, and various additives depending on the type of the curable compound to be used. You may go out.

The ratio of the total amount of the components (A), (B) and (C) to the total amount of the curable compound in the curable composition of the present invention is, for example, 60% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more. The ratio of the total amount of the components (A), (B) and (C) to the total amount of the curable composition of the present invention is, for example, 60% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more. It is.

The cationic polymerization initiator is an initiator (curing catalyst; acid generator) that releases a substance that initiates cationic polymerization by heating or light. As the cationic polymerization initiator, a thermal cationic polymerization initiator is preferable. The blending amount of the cationic polymerization initiator is, for example, 0 to 15% by weight, preferably 0.01 to 10% by weight, based on the entire curable composition. By mix | blending in this range, favorable hardened | cured materials, such as heat resistance, transparency, a weather resistance, can be obtained.

Examples of the cationic polymerization initiator include aryldiazonium salts [for example, PP-33, manufactured by Asahi Denka Kogyo Co., Ltd.], aryliodonium salts, arylsulfonium salts [for example, FC-509, manufactured by 3M Corporation], UVE1014 [G. E. CP-66, CP-77 [Asahi Denka Kogyo Co., Ltd.], SI-60L, SI-80L, SI-100L, SI-110L [Sanshin Chemical Industry Co., Ltd.], Allen -Ion complexes [for example, CG-24-61 manufactured by Ciba Geigy Co., Ltd.]. Further, a system of a chelate compound of a metal such as aluminum or titanium and an acetoacetate ester or diketone and a silanol or phenol is also used. Examples of the chelate compound include aluminum trisacetylacetonate and aluminum trisacetoacetate ethyl. Examples of silanols or phenols include triphenylsilanol and bisphenol S.

An acid anhydride can be used as a curing agent. As the acid anhydride, those generally used for curing epoxy compounds can be used, but those which are liquid at room temperature are preferred, and specifically, for example, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride , Dodecenyl succinic anhydride, methylendomethylenetetrahydrophthalic anhydride, and the like. In addition, acid anhydrides that are solid at room temperature, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylcyclohexene dicarboxylic acid anhydride, as long as the impregnation property of the curable composition of the present invention is not adversely affected. Etc. can be used. When an acid anhydride that is solid at room temperature is used, it is preferably dissolved in a liquid acid anhydride at room temperature and used as a liquid mixture at room temperature. The blending amount of the curing agent varies depending on the kind and amount of the cationic curable compound in the curable composition, but is, for example, 0 to 60% by weight, preferably 5 to 40% by weight, based on the entire curable composition. Degree.

The curing accelerator is a compound having a function of accelerating the curing reaction when an acid anhydride is used as the curing agent. The curing accelerator is not particularly limited as long as it is generally used. For example, a diazabicycloundecene-based curing accelerator (1,8-diazabicyclo [5.4.0] undecene-7 (DBU) or Salt thereof), tertiary amines such as benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, etc. Examples thereof include organic phosphine compounds such as imidazoles and triphenylphosphine, tertiary amine salts, quaternary ammonium salts, phosphonium salts, metal salts such as tin octylate and zinc octylate. Among these, diazabicycloundecene curing accelerators are preferable. The blending amount of the curing accelerator is, for example, about 0 to 5% by weight, preferably about 0.05 to 3% by weight, based on the entire curable composition. If the blending amount is too small, the curing accelerating effect may be insufficient, and if it is too large, the hue in the cured product may be deteriorated.

As the radical polymerization initiator (radical generator), those known and commonly used as light or thermal radical polymerization initiators can be used. Representative photoradical polymerization initiators include, for example, benzoin / benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2, 2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino- Acetophenones such as 1- (4-morpholinophenyl) -butan-1-one; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone Any anthraquinones; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-isopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenones such as benzophenone Xanthones; 1,7-bis (9-acridinyl) heptane and the like.

Typical thermal radical polymerization initiators include, for example, diacyl peroxides, peroxydicarbonates, alkyl peroxides, dialkyl peroxides, perketals, ketone peroxides, and organic peroxides in the form of alkyl hydroperoxides. Can be mentioned. Specific examples of these thermal polymerization initiators include dibenzoyl peroxide, t-butyl perbenzoate, azobisisobutyronitrile, and the like.

Commercially available radical polymerization initiators include, for example, Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenyl ketone) and Irgacure (registered trademark) 500 (1-hydroxycyclohexyl) available from Ciba as photo radical polymerization initiators. Phenylketone, benzophenone), and other photopolymerization initiators of the Irgacure® type; Darocur® 1173, 1116, 1398, 1174, and 1020 (available from Merck).

The blending amount of the radical polymerization initiator varies depending on the kind and amount of the radical polymerizable compound in the curable composition, but is, for example, about 0.1 to 20% by weight with respect to the entire curable composition.

The photosensitizer is preferably used in combination with a photopolymerization initiator. As the photosensitizer, those known and commonly used as photosensitizers can be used. For example, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylamino is used. Tertiary amines such as benzoate, triethylamine, triethanolamine and the like can be mentioned. These photosensitizers can be used alone or in combination of two or more. The content of the photosensitizer is not particularly limited, but is, for example, about 0.1 to 5% by weight with respect to the entire curable composition.

Examples of additives that may be added to the curable composition of the present invention include, for example, organosiloxane compounds, metal oxide particles, rubber particles, silicone-based and fluorine-based antifoaming agents, silane coupling agents, fillers, Examples thereof include a plasticizer, a leveling agent, an antistatic agent, a release agent, a flame retardant, a colorant, an antioxidant, an ultraviolet absorber, an ion adsorbent, and a pigment. The compounding quantity of these various additives is 5 weight% or less with respect to the whole curable composition, for example. The curable composition of the present invention may contain a solvent, but if it is too much, bubbles may be generated in the cured resin. Therefore, it is preferably 10% by weight or less, particularly 1% by weight based on the entire curable composition. It is as follows.

The curable composition of the present invention includes, for example, the above components (A), (B) and (C), a cationic polymerization initiator, a curing agent, a curing accelerator, a radical polymerization initiator, a photosensitizer, which are added as necessary. It is prepared by blending a sensitizer and various additives, and stirring and mixing while excluding bubbles as necessary under vacuum. The temperature at the time of stirring and mixing is, for example, about 10 to 60 ° C. For stirring and mixing, a known apparatus such as a rotation / revolution mixer, a single-screw or multi-screw extruder, a planetary mixer, a kneader, or a dissolver can be used.

According to the curable composition of the present invention, it is possible to obtain a cured resin excellent in both optical characteristics and physical characteristics. The obtained cured resin has a light transmittance (400 nm) of, for example, 80% or more (preferably 85% or more), an internal transmittance (400 nm) of, for example, 85% or more (preferably 90% or more), and a refractive index (589 nm). Is 1.55 or more (preferably 1.60 or more) and the Abbe number is 35 or less (preferably 30 or less), for example, and can be a cured resin having high transparency and resolution and excellent optical characteristics. The water absorption is, for example, 2% by weight or less (preferably 1% by weight or less), the glass transition point is, for example, 80 ° C. or more (preferably 100 ° C. or more), and the linear expansion coefficient is, for example, 120 ppm / K or less (preferably , 100 ppm / K or less), and the curing shrinkage rate is, for example, 10% or less (preferably 8% or less), and can be a cured resin excellent in terms of moldability and moisture resistance. Further, even when the cured resin is subjected to high temperature conditions (for example, about 260 ° C.), the light transmittance, the refractive index, and the Abbe number hardly change and the shape does not change.

The cationic curable composition of the present invention provides a cured resin that hardly changes in optical properties and physical properties even at high temperatures due to curing. Therefore, in particular, optical applications (optical material applications), optical device applications, display device applications, electrical -It can be suitably used for electronic component material applications.

The refractive index of the lens varies depending on the wavelength of light, and a phenomenon (chromatic aberration) that causes deviation (bleeding or blurring) in the image occurs. In order to reduce the influence of this chromatic aberration, a normal lens has a structure that corrects chromatic aberration by combining a lens resin having a high Abbe number and a lens resin having a low Abbe number. The glass of a lens used in a camera is classified into two types according to the Abbe number. Generally, those having an Abbe number of 50 or less are called flint glass, and those having 50 or more are called crown glass. The cured resin obtained from the curable composition of the present invention can be suitably used as a lens resin having a low Abbe number.

The cured product of the present invention can be obtained by curing the curable composition. As a curing method, an appropriate method can be selected from known curing methods according to the type of the curable compound in the curable composition. For example, the curable composition can be placed in a mold matched to the shape of the cured product, cured by irradiation with active energy rays (for example, ultraviolet rays), and further heated to obtain the desired cured product. Moreover, the target hardened | cured material can also be obtained only by heating. When ultraviolet rays are used as the active energy ray, the irradiation amount is, for example, about 1000 to 4000 mJ / cm ² . The heating temperature varies depending on the type of the curable compound, but is, for example, about 80 to 200 ° C., preferably about 110 to 160 ° C. In addition, after taking out hardened | cured material from a metal mold | die, you may post-cure (bake).

As described above, the cured product of the present invention is preferably used as an optical member because its optical characteristics and physical characteristics are hardly changed even at a high temperature of about 260 ° C., for example. Examples of the optical member include an imaging lens, a spectacle lens, a filter, a diffraction grating, a prism, a light guide, and a light beam collection for a camera (on-vehicle camera, digital camera, PC camera, mobile phone camera, surveillance camera, etc.). Optical lens, light diffusion lens, cover glass for display device, photo sensor, photo switch, LED, light emitting element, optical waveguide, optical splitter, optical fiber adhesive, display element substrate, color filter substrate, touch panel substrate, Examples include a display protective film, a display backlight, a light guide plate, and an antireflection film.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
30 parts by weight of aromatic epoxy compound [produced by Osaka Gas Chemical Co., Ltd., trade name “Ogsol” (fluorene derivative epoxy compound); contained in compound represented by formula (A-3)], aromatic (meth) acrylate (Made by Osaka Gas Chemical Company, trade name “Ogsol” (fluorene derivative (meth) acrylate); contained in the compound represented by the formula (B-1)), 50 parts by weight, (meth) acryl having an epoxy group Acid ester [epoxidized dicyclopentenyl acrylate (= 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decan-8-yl acrylate and 3,4-epoxytricyclo [5.2.1 .0 ^2,6] decan-9-yl acrylate, the formula (1-1) contained in the compound represented by Daicel chemical Industries Ltd., trade name "E-DCPA"] 20 parts by weight, 1 part by weight of an acid generator (arylsulfonium salt-based acid generator; manufactured by Sanshin Chemical Co., Ltd., trade name “SI-60L”), radical generator (acetophenone-based radical generator; manufactured by Ciba Geigy Co., Ltd., trade name “ Irgacure 184 ") was blended at a ratio of 1 part by weight, and stirred and mixed with a rotation / revolution mixer to obtain a uniform and transparent curable composition (optical material composition liquid). The composition liquid was cast into a glass mold having a thickness of 1 mm, which was previously applied with a release agent and evaporated.
Next, the cast optical material composition is irradiated with ultraviolet rays (irradiation amount: 2,600 mJ / cm ² ) to produce a cured resin, and the produced cured product is heated at 160 ° C. for 1 hour in an air atmosphere. A plate-shaped transparent and uniform cured resin having a thickness of 1 mm was obtained. This cured resin could be easily released from the glass mold. The obtained cured resin was subjected to the evaluation described later.

Comparative Example 1
A cured resin was obtained in the same manner as in Example 1 except that the (meth) acrylic acid ester having an epoxy group was not blended.

Various characteristics and heat resistance tests (evaluation of yellowing resistance under reflow conditions) of the cured resins obtained in the examples and comparative examples were performed according to the following methods and conditions. The results are shown in Table 1.

(1) Shape of resin surface The presence or absence of pulsation on the resin surface of the cured resin was examined visually. The pulse separation means an optically inhomogeneous state, and indicates wrinkles and fluctuations observed on the surface of the cured resin.

(2) Internal transmittance The internal transmittance of the cured resin was calculated by the following equation.
Internal transmittance (400 nm) = Light transmittance at 400 nm / (1 −r) ²
r = {(n−1) / (n + 1)} ²
n is the refractive index at 400 nm. The light transmittance at 400 nm was measured using a spectrophotometer (trade name “U-3900” manufactured by Hitachi High-Technologies Corporation), and the refractive index was the value of the refractive index at 400 nm measured by the following method (3). Was used.

(3) Refractive index The refractive index of the cured resin was measured by a method based on JIS K7142, using a refractometer (trade name “Model 2010”, manufactured by Metricon Co., Ltd.) at 589 nm at 25 ° C.

(4) Glass transition temperature and coefficient of linear expansion The glass transition temperature and coefficient of linear expansion of the cured resin were measured using a TMA measuring device (trade name “TMA / SS100” manufactured by SII NanoTechnology Co., Ltd.) at a rate of temperature increase of 5 ° C. / Min, measuring the thermal expansion coefficient in the measurement temperature range of 30 ° C to 250 ° C, taking the intersection of the tangent of the low temperature side straight line and the high temperature side straight line as the glass transition temperature, and linearly expanding the gradient of the low temperature side straight line Expressed as a coefficient.

(5) Water absorption The water absorption of the cured resin was measured by a method based on JIS K7209.

(6) Abbe number The Abbe number of the cured resin was calculated by the following equation.
Abbe number = (n _d −1) / (n _F −n _C )
In the formula, n _d represents a refractive index at 589.2 nm, n _F represents a refractive index at 486.1 nm, and n _C represents a refractive index at 656.3 nm. In addition, as a refractive index, the value of the refractive index in each wavelength measured by the method of said (3) was used.

(7) Heat resistance test (evaluation of yellowing resistance under reflow conditions)
After three consecutive heat resistance tests in which the cured resin was preheated to 270 ° C. for 1 minute in an air atmosphere, the transmittance at 400 nm and the refractive index at 400 nm of the cured resin subjected to the heat resistance measurement were measured. The internal transmittance was calculated.
Yellowing resistance under reflow conditions was evaluated using the rate of decrease in internal transmittance calculated from the following formula as the yellowing rate.
Decrease rate of internal transmittance (%) = (Internal transmittance before heat test-Internal transmittance after heat test) / (Internal transmittance before heat test) · 100

In the curable composition of Example 1 using the (meth) acrylate compound having a specific structure having an alicyclic epoxy group, compared with the curable composition of Comparative Example 1 not using the compound, the light transmittance, glass A cured resin having an extremely high transition temperature could be obtained. Moreover, in the yellowing resistance evaluation under reflow conditions, the cured resin of Comparative Example 1 after the heat resistance test was fogged on the resin surface, resulting in a significant loss of transparency. Therefore, a cured resin obtained from a curable composition using a (meth) acrylate compound having a specific structure having an alicyclic epoxy group, particularly using a (meth) acrylate compound having an epoxy group in the molecule is heat resistant. Since it is high and has high transparency, it can be suitably used for various applications such as optical applications such as lens units and optical device applications.

According to the curable composition of the present invention, by curing, it has high light transmittance and refractive index, and optical properties (light transmittance, refractive index, Abbe number, etc.) and physical properties change even under high temperature conditions. Since a low Abbe number cured resin having the property of being difficult can be obtained, it is particularly suitable for various uses such as an optical member application such as a lens and an optical device application.

Claims

It contains an epoxy compound (A) having an aromatic ring, a (meth) acrylic acid ester (B) having an aromatic ring, and a (meth) acrylic acid ester (C) having an epoxy group in the molecule. Curable composition.
(Meth) acrylic acid ester (C) having an epoxy group in the molecule is at least one selected from (meth) acrylic acid ester having an alicyclic epoxy group and (meth) acrylic acid ester having a glycidyl group The curable composition according to claim 1, which is a compound.
The (meth) acrylic acid ester (C) having an epoxy group in the molecule is represented by the following formula (1)

(In the formula, R a represents a hydrogen atom or a methyl group, and Y a represents a single bond, an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 to 2 or more carbon atoms and 1 or 2 or more. oxygen atom (-O-) and represents the bound group, ring Z a represents an alicyclic epoxy group)
The curable composition according to claim 1, which is a (meth) acrylic acid ester having an alicyclic epoxy group represented by:
Alicyclic epoxy group in the ring Z a is a compound represented by the following formula (a)

The curable composition of Claim 3 which is group represented by these.
The epoxy compound (A) having an aromatic ring has at least one aromatic ring selected from the group consisting of a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring, and a carbazole ring. The curable composition according to any one of claims 1 to 4, which is an epoxy compound.
The (meth) acrylic acid ester (B) having an aromatic ring is at least one selected from the group consisting of a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring, and a carbazole ring. 6. The curable composition according to claim 1, which is a (meth) acrylic acid ester having an aromatic ring.
A cured resin obtained by curing the curable composition according to any one of claims 1 to 6.
An optical member made of the cured resin according to claim 7.