JP6474719B2 - Curable composition, cured product thereof, optical member, and optical apparatus - Google Patents

Description

  The present invention relates to a curable composition, a cured product obtained by curing the curable composition, a composition for forming an optical member, and an optical member and an optical device obtained using the composition for forming an optical member. About. This application claims the priority of Japanese Patent Application No. 2013-029688 for which it applied to Japan on February 19, 2013, and uses the content here.

  In recent years, in applications where glass materials have been used in the past, such as lenses, prisms, optical filters, portable devices, display devices, etc., alternatives to resin materials have been actively studied. There is a demand for a resin material excellent in the above. In particular, in applications such as lenses, a resin material (for example, a resin material having a high refractive index and a low Abbe number) in which various optical characteristics are controlled with a specific balance is required.

  Patent Document 1 discloses an aromatic skeleton-containing alicyclic epoxy comprising a specific aromatic skeleton-containing alicyclic epoxy compound and a cationic curing catalyst as a resin composition for forming an optical member. A resin composition is disclosed. According to the said resin composition, it is supposed that high refractive index and cation hardening reactivity can be made compatible (refer patent document 1).

  Patent Document 2 discloses a resin composition containing an organic resin component, and the resin composition has a specific ratio of an organic resin component having a molecular weight of 700 or more and an organic resin component having a molecular weight of less than 700 in the molecular weight distribution. The organic resin component includes an aromatic epoxy compound, and the organic resin component having a molecular weight of 700 or more and the organic resin component having a molecular weight of less than 700 are respectively an alicyclic epoxy compound, a hydrogenated epoxy compound, and an aromatic compound. There is disclosed a resin composition for optical member molded bodies, comprising at least one selected from the group consisting of epoxy compounds, wherein the resin composition further contains a release agent. The resin composition is rich in processability, and the cured product after curing the resin composition has high strength and is excellent in handling such as not cracking at the time of release (see Patent Document 2). ).

JP 2009-179568 A JP 2010-13667 A

  However, in Patent Document 1, although there is a description about improving the cationic curing reactivity, the resin composition disclosed in the document is still insufficient in curability and poor curing when obtaining a cured product The problem was occurring. Further, the resin composition disclosed in Patent Document 2 also has a problem of poor curing due to insufficient curability. For this reason, as a curable composition for forming an optical member (a curable composition for forming an optical member), a cured product having a sufficiently high curing rate (fast curing), and further having high heat resistance and transparency. There is a need for something that can be formed. In particular, a thermocationic curable composition that has a high curing rate and can form a cured product having a low Abbe number has not yet been obtained.

  In addition to the above-mentioned various characteristics (fast curing, heat resistance, transparency, high refractive index, and low Abbe number), a curable composition for forming an optical member is formed. There is also a demand for a low shrinkage in curing and excellent shape stability.

  In particular, regarding shape stability, for example, even when the curable composition is used for wafer level lens applications, and the wafer level lens is placed in a high temperature environment by annealing or the like, there is a problem with the lens shape. It is required not to occur. Specifically, when a curable composition is molded with a mold, there is usually distortion due to residual stress inside the obtained cured product (molded product). In order to remove this distortion, annealing (heating) is often performed after the cured product is taken out of the mold. However, annealing treatment tends to cause “sag” in the shape of the cured product, especially in the case of a wafer level lens, the center position of the lens shifts, or when multiple lenses are stacked, There is a high possibility that a problem of reduced accuracy such as blurring will occur.

Therefore, the object of the present invention is excellent in quick curing and shape stability at the time of curing, and has high heat resistance, high transparency, high refractive index, and low Abbe number optical characteristics by curing. Another object of the present invention is to provide a curable composition capable of forming a cured product and a cured product thereof.
Another object of the present invention is to provide an optical member having high accuracy, excellent optical characteristics, and high productivity, and an optical device having the optical member.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that curability containing an alicyclic epoxy compound having a specific structure, a cationic polymerizable compound having a specific structure, and a thermal cationic curing agent as essential components. When the composition is cured, it is excellent in quick curing and shape stability, and is cured to provide a cured product having high heat resistance, high transparency, high refractive index, and low Abbe number optical characteristics. The present invention was completed by finding that it can be formed.

  That is, the present invention is a curable composition comprising an alicyclic epoxy compound (A) having no ester group, a cationic polymerizable compound (B) having an aromatic ring, and a thermal cationic curing agent (C), Provided is a curable composition wherein the alicyclic epoxy compound (A) having no group is a compound having at least two epoxidized cyclic olefin groups.

  Furthermore, the said curable composition whose epoxidized cyclic olefin group is a group in which the C5-C12 cyclic olefin group was epoxidized is provided.

  Further, the above curing, wherein the alicyclic epoxy compound (A) having no ester group is a compound having a structure in which at least two of the epoxidized cyclic olefin groups are bonded with a single bond or a divalent hydrocarbon group. A sex composition is provided.

  Furthermore, the content of the alicyclic epoxy compound (A) having no ester group is 10 to 60% by weight based on the total amount (100% by weight) of the curable composition. .

  Further, the curable composition wherein the cationic polymerizable compound (B) having an aromatic ring has at least one cationic curable functional group selected from the group consisting of an alicyclic epoxy group, a glycidyl group, and an oxetanyl group. I will provide a.

  Furthermore, the content of the cationically polymerizable compound (B) having an aromatic ring is 40 to 90% by weight with respect to the total amount (100% by weight) of the curable composition.

  Furthermore, the said curable composition whose hardening start temperature is 60-150 degreeC is provided.

  Furthermore, the said curable composition whose Abbe number of the hardened | cured material obtained by hardening is 35 or less is provided.

  Furthermore, the said curable composition containing the mold release agent which has a cationic curable functional group is provided.

  Furthermore, the said curable composition which is a composition for optical member formation is provided.

  Moreover, this invention provides the hardened | cured material obtained by hardening the said curable composition.

  The present invention also provides an optical member having a cured product obtained by curing the curable composition.

  Moreover, this invention provides the optical apparatus which has the said optical member.

［式（ａ１）中、Ｒは、エポキシ化環状オレフィン基を示す。Ｘは、単結合又は２価の炭化水素基を示す。］
で表される化合物である［１］〜［３］のいずれか１つに記載の硬化性組成物。
［５］エステル基を有しない脂環エポキシ化合物（Ａ）が、式（ａ１）中の２つのＲがともにシクロヘキセンオキシド基である化合物である［４］に記載の硬化性組成物。
［６］エステル基を有しない脂環エポキシ化合物（Ａ）が、２つのシクロヘキセンオキシド基の４位の炭素原子が単結合又は２価の炭化水素基によって連結された化合物である［５］に記載の硬化性組成物。
［７］エステル基を有しない脂環エポキシ化合物（Ａ）の含有量が、硬化性組成物の総量（１００重量％）に対して、１０〜６０重量％である［１］〜［６］のいずれか１つに記載の硬化性組成物。
［８］エステル基を有しない脂環エポキシ化合物（Ａ）及び芳香環を有するカチオン重合性化合物（Ｂ）の総量（１００重量％）に対するエステル基を有しない脂環エポキシ化合物（Ａ）の割合が、１０〜６０重量％である［１］〜［７］のいずれか１つに記載の硬化性組成物。
［９］芳香環を有するカチオン重合性化合物（Ｂ）が有する芳香環が、芳香族炭化水素環である［１］〜［８］のいずれか１つに記載の硬化性組成物。
［１０］芳香環を有するカチオン重合性化合物（Ｂ）が分子内に有する芳香環の数が１〜１０個である［１］〜［９］のいずれか１つに記載の硬化性組成物。
［１１］芳香環を有するカチオン重合性化合物（Ｂ）が、脂環エポキシ基、グリシジル基、及びオキセタニル基からなる群より選択された少なくとも１種のカチオン硬化性官能基を有する［１］〜［１０］のいずれか１つに記載の硬化性組成物。
［１２］芳香環を有するカチオン重合性化合物（Ｂ）が分子内に有するカチオン硬化性官能基の数が１〜１０個である［１］〜［１１］のいずれか１つに記載の硬化性組成物。
［１３］芳香環を有するカチオン重合性化合物（Ｂ）が下記式（ｂ１）で表される化合物である［１］〜［１２］のいずれか１つに記載の硬化性組成物。

［式（ｂ１）中、Ｒ¹〜Ｒ⁵、Ｒ⁷〜Ｒ¹¹は、同一又は異なって、水素原子又は炭素数１〜６のアルキル基を示す。環Ｚ¹、環Ｚ²は、同一又は異なって、芳香族炭素環（芳香族炭化水素環）を示す。Ｒ⁶、Ｒ¹²は、同一又は異なって、炭素数１〜１０のアルキレン基を示す。ｐ１、ｐ２は、同一又は異なって、０以上の整数である。］
［１４］芳香環を有するカチオン重合性化合物（Ｂ）の含有量が、硬化性組成物の総量（１００重量％）に対して、４０〜９０重量％である［１］〜［１３］のいずれか１つに記載の硬化性組成物。
［１５］硬化性組成物の総量（１００重量％）に対するエステル基を有しない脂環エポキシ化合物（Ａ）及び芳香環を有するカチオン重合性化合物（Ｂ）の総量の割合が、８０重量％以上、１００重量％未満である［１］〜［１４］のいずれか１つに記載の硬化性組成物。
［１６］熱カチオン硬化剤（Ｃ）が熱カチオン重合開始剤である［１］〜［１５］のいずれか１つに記載の硬化性組成物。
［１７］熱カチオン硬化剤（Ｃ）の含有量（配合量）が、硬化性組成物に含まれるカチオン硬化性化合物の総量１００重量部に対して、０．００１〜１０重量部である［１］〜［１６］のいずれか１つに記載の硬化性組成物。
［１８］硬化開始温度が６０〜１５０℃である［１］〜［１７］のいずれか１つに記載の硬化性組成物。
［１９］さらに、酸化防止剤を含む［１］〜［１８］のいずれか１つに記載の硬化性組成物。
［２０］酸化防止剤がフェノール系酸化防止剤である［１９］に記載の硬化性組成物。
［２１］酸化防止剤の含有量（配合量）が、硬化性組成物に含まれるカチオン硬化性化合物の総量１００重量部に対して、０．００１〜１５重量部である［１９］又は［２０］に記載の硬化性組成物。
［２２］硬化させて得られる硬化物のアッベ数が３５以下である［１］〜［２１］のいずれか１つに記載の硬化性組成物。
［２３］さらに、カチオン硬化性官能基を有する離型剤を含む［１］〜［２２］のいずれか１つに記載の硬化性組成物。
［２４］前記離型剤が有するカチオン硬化性官能基の数が、１〜４個である［２３］に記載の硬化性組成物。
［２５］前記離型剤が、エポキシ基を有するフッ素置換炭化水素である［２３］又は［２４］に記載の硬化性組成物。
［２６］前記エポキシ基を有するフッ素置換炭化水素が、下記式（ｉ）で表される化合物である［２５］に記載の硬化性組成物。

［式（ｉ）におけるｒは１〜１５の整数を示す。ｓは１〜５の整数を示す。Ｙは、水素原子、フッ素原子、又はフルオロアルキル基を示す。式（ｉ）における−（ＣＨ₂）_r−は、水素原子の一部がヒドロキシル基に置換されたものであってもよく、また、途中にエーテル結合が含まれたものであってもよい。］
［２７］前記離型剤の含有量（配合量）が、エステル基を有しない脂環エポキシ化合物（Ａ）及び芳香環を有するカチオン重合性化合物（Ｂ）の総量１００重量部に対して、０．０１〜１０重量部である［２３］〜［２６］のいずれか１つに記載の硬化性組成物。
［２８］硬化性組成物に含まれる硬化性化合物の総量（１００重量％）に対するカチオン重合性化合物の総量の割合が、８０〜１００重量％である［１］〜［２７］のいずれか１つに記載の硬化性組成物。
［２９］硬化させて得られる硬化物の４００ｎｍにおける内部透過率［厚み０．５ｍｍ換算］が、７０〜１００％である［１］〜［２８］のいずれか１つに記載の硬化性組成物。
［３０］硬化させて得られる硬化物の５８９ｎｍにおける屈折率（２５℃）が、１．５８以上である［１］〜［２９］のいずれか１つに記載の硬化性組成物。
［３１］硬化させて得られる硬化物のガラス転移温度が、１００〜２００℃である［１］〜［３０］のいずれか１つに記載の硬化性組成物。
［３２］硬化させて得られる硬化物のガラス転移温度以下における線膨張係数（α１）が、４０〜１００ｐｐｍ／Ｋである［１］〜［３１］のいずれか１つに記載の硬化性組成物。
［３３］硬化させて得られる硬化物のガラス転移温度以上における線膨張係数（α２）が、９０〜１５０ｐｐｍ／Ｋである［１］〜［３２］のいずれか１つに記載の硬化性組成物。
［３４］光学部材形成用組成物である［１］〜［３３］のいずれか１つに記載の硬化性組成物。
［３５］［１］〜［３４］のいずれか１つに記載の硬化性組成物を硬化させて得られる硬化物。
［３６］４００ｎｍにおける内部透過率［厚み０．５ｍｍ換算］が、７０〜１００％である［３５］に記載の硬化物。
［３７］５８９ｎｍにおける屈折率（２５℃）が、１．５８以上である［３５］又は［３６］に記載の硬化物。
［３８］ガラス転移温度が、１００〜２００℃である［３５］〜［３７］のいずれか１つに記載の硬化物。
［３９］ガラス転移温度以下における線膨張係数（α１）が、４０〜１００ｐｐｍ／Ｋである［３５］〜［３８］のいずれか１つに記載の硬化物。
［４０］ガラス転移温度以上における線膨張係数（α２）が、９０〜１５０ｐｐｍ／Ｋである［３５］〜［３９］のいずれか１つに記載の硬化物。
［４１］アッベ数が３５以下である［３５］〜［４０］のいずれか１つに記載の硬化物。
［４２］［３４］に記載の硬化性組成物を硬化させて得られる硬化物を有する光学部材。
［４３］［４２］に記載の光学部材を有する光学装置。That is, the present invention relates to the following.
[1] A curable composition comprising an alicyclic epoxy compound (A) having no ester group, a cationic polymerizable compound (B) having an aromatic ring, and a thermal cationic curing agent (C), having an ester group. The curable composition characterized in that the alicyclic epoxy compound (A) which is not used is a compound having at least two epoxidized cyclic olefin groups.
[2] The curable composition according to [1], wherein the epoxidized cyclic olefin group is a group in which a cyclic olefin group having 5 to 12 carbon atoms is epoxidized.
[3] The alicyclic epoxy compound (A) having no ester group is a compound having a structure in which at least two of the epoxidized cyclic olefin groups are bonded by a single bond or a divalent hydrocarbon group [1] ] Or the curable composition as described in [2].
[4] An alicyclic epoxy compound (A) having no ester group is represented by the following formula (a1)

[In the formula (a1), R represents an epoxidized cyclic olefin group. X represents a single bond or a divalent hydrocarbon group. ]
The curable composition according to any one of [1] to [3], which is a compound represented by:
[5] The curable composition according to [4], wherein the alicyclic epoxy compound (A) having no ester group is a compound in which two Rs in the formula (a1) are both cyclohexene oxide groups.
[6] The alicyclic epoxy compound (A) having no ester group is a compound in which the 4-position carbon atom of two cyclohexene oxide groups is linked by a single bond or a divalent hydrocarbon group. Curable composition.
[7] The content of the alicyclic epoxy compound (A) having no ester group is 10 to 60% by weight with respect to the total amount (100% by weight) of the curable composition. The curable composition as described in any one.
[8] The ratio of the alicyclic epoxy compound (A) having no ester group to the total amount (100% by weight) of the alicyclic epoxy compound (A) having no ester group and the cationic polymerizable compound (B) having an aromatic ring is The curable composition according to any one of [1] to [7], which is 10 to 60% by weight.
[9] The curable composition according to any one of [1] to [8], wherein the aromatic ring included in the cationically polymerizable compound (B) having an aromatic ring is an aromatic hydrocarbon ring.
[10] The curable composition according to any one of [1] to [9], wherein the cationic polymerizable compound (B) having an aromatic ring has 1 to 10 aromatic rings in the molecule.
[11] The cationically polymerizable compound (B) having an aromatic ring has at least one cationically curable functional group selected from the group consisting of an alicyclic epoxy group, a glycidyl group, and an oxetanyl group. 10] The curable composition as described in any one of [10].
[12] The curability according to any one of [1] to [11], wherein the cationically polymerizable compound (B) having an aromatic ring has 1 to 10 cationically curable functional groups in the molecule. Composition.
[13] The curable composition according to any one of [1] to [12], wherein the cationic polymerizable compound (B) having an aromatic ring is a compound represented by the following formula (b1).

[In formula (b1), R ^{1 to} R ⁵ and R ^{7 to} R ¹¹ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ring Z ¹ and ring Z ² are the same or different and represent an aromatic carbocyclic ring (aromatic hydrocarbon ring). R ⁶ and R ¹² are the same or different and each represents an alkylene group having 1 to 10 carbon atoms. p1 and p2 are the same or different and are integers of 0 or more. ]
[14] Any of [1] to [13], wherein the content of the cationic polymerizable compound (B) having an aromatic ring is 40 to 90% by weight relative to the total amount (100% by weight) of the curable composition. The curable composition as described in any one.
[15] The ratio of the total amount of the alicyclic epoxy compound (A) having no ester group and the cationic polymerizable compound (B) having an aromatic ring to the total amount (100% by weight) of the curable composition is 80% by weight or more, The curable composition according to any one of [1] to [14], which is less than 100% by weight.
[16] The curable composition according to any one of [1] to [15], wherein the thermal cationic curing agent (C) is a thermal cationic polymerization initiator.
[17] The content (blending amount) of the thermal cation curing agent (C) is 0.001 to 10 parts by weight with respect to 100 parts by weight of the total amount of cation curable compounds contained in the curable composition. ] The curable composition as described in any one of [16].
[18] The curable composition according to any one of [1] to [17], wherein a curing start temperature is 60 to 150 ° C.
[19] The curable composition according to any one of [1] to [18], further comprising an antioxidant.
[20] The curable composition according to [19], wherein the antioxidant is a phenolic antioxidant.
[21] The content (blending amount) of the antioxidant is 0.001 to 15 parts by weight with respect to 100 parts by weight of the total amount of the cationic curable compounds contained in the curable composition [19] or [20 ] The curable composition as described in above.
[22] The curable composition according to any one of [1] to [21], wherein the cured product obtained by curing has an Abbe number of 35 or less.
[23] The curable composition according to any one of [1] to [22], further including a release agent having a cationic curable functional group.
[24] The curable composition according to [23], wherein the release agent has 1 to 4 cationic curable functional groups.
[25] The curable composition according to [23] or [24], wherein the release agent is a fluorine-substituted hydrocarbon having an epoxy group.
[26] The curable composition according to [25], wherein the fluorine-substituted hydrocarbon having an epoxy group is a compound represented by the following formula (i).

[R in the formula (i) represents an integer of 1 to 15. s shows the integer of 1-5. Y represents a hydrogen atom, a fluorine atom, or a fluoroalkyl group. — (CH ₂ ) _r — in the formula (i) may be one in which a part of hydrogen atoms is substituted with a hydroxyl group, or may contain an ether bond in the middle. ]
[27] The content (blending amount) of the release agent is 0 with respect to 100 parts by weight of the total amount of the alicyclic epoxy compound (A) having no ester group and the cationic polymerizable compound (B) having an aromatic ring. The curable composition according to any one of [23] to [26], which is 0.01 to 10 parts by weight.
[28] Any one of [1] to [27], wherein the ratio of the total amount of the cationically polymerizable compound to the total amount (100% by weight) of the curable compound contained in the curable composition is 80 to 100% by weight. The curable composition according to 1.
[29] The curable composition according to any one of [1] to [28], wherein the cured product obtained by curing has an internal transmittance at 400 nm [in terms of thickness of 0.5 mm] of 70 to 100%. .
[30] The curable composition according to any one of [1] to [29], wherein a cured product obtained by curing has a refractive index (25 ° C.) at 589 nm of 1.58 or more.
[31] The curable composition according to any one of [1] to [30], in which a cured product obtained by curing has a glass transition temperature of 100 to 200 ° C.
[32] The curable composition according to any one of [1] to [31], wherein the cured product obtained by curing has a linear expansion coefficient (α1) at a glass transition temperature or lower of 40 to 100 ppm / K. .
[33] The curable composition according to any one of [1] to [32], wherein the cured product obtained by curing has a linear expansion coefficient (α2) at a glass transition temperature or higher of 90 to 150 ppm / K. .
[34] The curable composition according to any one of [1] to [33], which is a composition for forming an optical member.
[35] A cured product obtained by curing the curable composition according to any one of [1] to [34].
[36] The cured product according to [35], wherein the internal transmittance at 400 nm [in terms of thickness 0.5 mm] is 70 to 100%.
[37] The cured product according to [35] or [36], wherein a refractive index (25 ° C.) at 589 nm is 1.58 or more.
[38] The cured product according to any one of [35] to [37], which has a glass transition temperature of 100 to 200 ° C.
[39] The cured product according to any one of [35] to [38], in which a linear expansion coefficient (α1) at a glass transition temperature or lower is 40 to 100 ppm / K.
[40] The cured product according to any one of [35] to [39], which has a linear expansion coefficient (α2) at a glass transition temperature or higher of 90 to 150 ppm / K.
[41] The cured product according to any one of [35] to [40], which has an Abbe number of 35 or less.
[42] An optical member having a cured product obtained by curing the curable composition according to [34].
[43] An optical device having the optical member according to [42].

  Since the curable composition of the present invention has the above-described configuration, it is excellent in rapid curability and shape stability at the time of curing, and has high heat resistance, high transparency, high refractive index, and low Abbe by curing. A cured product having a number of optical properties can be formed. In particular, since the curable composition of the present invention has a small shrinkage in curing and is excellent in shape stability, the use of the curable composition can contribute to the design of a highly accurate optical member. Further, when the alicyclic epoxy compound (A) in the curable composition of the present invention is in a liquid state, a diluting component (such diluting component can adversely affect the refractive index and Abbe number of the cured product) is separately provided. Since it is not necessary to add, it is possible to achieve fast curability while maintaining the high refractive index and low Abbe number optical properties of the cured product. Furthermore, since the optical member and the optical device of the present invention have the above-described configuration, the optical member and the optical device have high accuracy, excellent optical characteristics, and high productivity.

<Curable composition>
The curable composition of the present invention includes an alicyclic epoxy compound (A) having no ester group, a cationic polymerizable compound (B) having an aromatic ring, and a thermal cationic curing agent (C) as essential components. It is a thing. The curable composition of the present invention may contain, in addition to the above-described essential components, other components such as an antioxidant, a release agent, and various additives described below. In addition, the curable composition of this invention can be used as a thermosetting composition which hardens | cures by heating and forms hardened | cured material (resin hardened | cured material).

[Alicyclic epoxy compound (A)]
Alicyclic epoxy compound (A) having no ester group (ester bond) in the curable composition of the present invention (hereinafter sometimes simply referred to as “alicyclic epoxy compound (A)” or “component (A)”) Is a compound having no ester group (ester bond) in the molecule and having at least two epoxidized cyclic olefin groups in the molecule. The “epoxidized cyclic olefin group” of the alicyclic epoxy compound (A) is a cyclic olefin (a cyclic aliphatic hydrocarbon in which at least one of the carbon-carbon bonds forming the ring is a carbon-carbon unsaturated bond). Is a group (monovalent group) formed by removing one hydrogen atom from an epoxidized structure in which at least one of the carbon-carbon unsaturated bonds of the compound is epoxidized. It may be referred to as “ring epoxy group”. That is, the epoxidized cyclic olefin group includes an aliphatic hydrocarbon ring structure and an epoxy group, and the epoxy group is composed of two adjacent carbon atoms and oxygen atoms constituting the aliphatic hydrocarbon ring. It is a group that is an epoxy group.

  Examples of the cyclic olefin group (form before epoxidation) in the epoxidized cyclic olefin group include a cyclopropenyl group (for example, 2-cyclopropen-1-yl group) and a cyclobutenyl group (for example, 2-cyclobutene-1). -Yl group, etc.), cyclopentenyl group (eg, 2-cyclopenten-1-yl group, 3-cyclopenten-1-yl group, etc.), cyclohexenyl group (eg, 2-cyclohexen-1-yl group, 3-cyclohexene) Cycloalkenyl groups such as -1-yl group, etc .; 2,4-cyclopentadien-1-yl group, 2,4-cyclohexadien-1-yl group, 2,5-cyclohexadien-1-yl group, etc. A cycloalkadienyl group; a polycyclic group such as a dicyclopentenyl group, a dicyclohexenyl group, and a norbornenyl group.

One or more substituents may be bonded to the aliphatic hydrocarbon ring forming the cyclic olefin group in the epoxidized cyclic olefin group. Examples of the substituent include substituents having 0 to 20 carbon atoms (more preferably, 0 to 10 carbon atoms), and more specifically, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like. A halogen atom; a hydroxy group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group and an isobutyloxy group (preferably a C _1-6 alkoxy group, more preferably a C _1-4 alkoxy group); An alkenyloxy group such as an allyloxy group (preferably a C _2-6 alkenyloxy group, more preferably a C _2-4 alkenyloxy group); a C _1-4 alkyl group on an aromatic ring such as a phenoxy group, a tolyloxy group, a naphthyloxy group, etc. group, C _2-4 alkenyl group, a halogen atom, the substituent aryloxy group which may have a (preferably such as C _1-4 alkoxy C _6-14 aryl Alkoxy group); a benzyloxy group, an aralkyloxy group (preferably a C _7-18 aralkyloxy group) such as a phenethyloxy group; an acetyl group, propionyloxy group, (meth) acryloyloxy group, an acyloxy group such as a benzoyloxy group (Preferably C _1-12 acyloxy group); mercapto group; alkylthio group such as methylthio group and ethylthio group (preferably C _1-6 alkylthio group, more preferably C _1-4 alkylthio group); alkenylthio such as allylthio group A group (preferably a C _2-6 alkenylthio group, more preferably a C _2-4 alkenylthio group); a C _1-4 alkyl group, a C _2-4 alkenyl group on an aromatic ring, such as a phenylthio group, a tolylthio group, a naphthylthio group, etc. group, halogen atom, C _1-4 optionally arylthio group which may have a substituent such as an alkoxy group (preferably C _6-14 Riruchio group); benzylthio group, aralkylthio group (preferably a C _7-18 aralkylthio group such as a phenethylthio group); carboxy; methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, an alkoxycarbonyl group such as a butoxycarbonyl group (Preferably C _1-6 alkoxy-carbonyl group); aryloxycarbonyl group such as phenoxycarbonyl group, tolyloxycarbonyl group, naphthyloxycarbonyl group (preferably C _6-14 aryloxy-carbonyl group); benzyloxycarbonyl group aralkyloxycarbonyl group (preferably a C _7-18 aralkyloxy - group) and the like; amino group; methylamino group, ethylamino group, dimethylamino group, mono- or dialkylamino group (preferably mono- diethylamino group Di -C _1-6 alkylamino group) is, acetylamino group, propionylamino group, an acylamino group (preferably a C _1-11 acylamino group such as benzoylamino group); ethyloxalic oxetanyl group-containing group such as a Seta oxy group; acetyl Group, an acyl group such as a propionyl group, a benzoyl group; an oxo group; a group in which two or more of these are bonded via a C _1-6 alkylene group, if necessary.

  Especially, as said cyclic olefin group, a C5-C12 cyclic olefin group is preferable, More preferably, it is a C5-C12 cycloalkenyl group, More preferably, it is a cyclohexenyl group. That is, the epoxidized cyclic olefin group is preferably a group in which a cyclic olefin group having 5 to 12 carbon atoms is epoxidized, more preferably a group in which a cycloalkenyl group having 5 to 12 carbon atoms is epoxidized, and further preferably. Is a group (cyclohexene oxide group) in which a cyclohexenyl group is epoxidized. In addition, an alicyclic epoxy compound (A) may have 1 type of an epoxidized cyclic olefin group, and may have 2 or more types.

  The number of epoxidized cyclic olefin groups in the molecule of the alicyclic epoxy compound (A) is not particularly limited as long as it is 2 or more, but 2 to 4 is preferable, and 2 is more preferable.

  As the alicyclic epoxy compound (A), a compound having a structure in which at least two epoxidized cyclic olefin groups are bonded by a single bond or a divalent hydrocarbon group is preferable. Examples of the divalent hydrocarbon group include a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, and a group in which a plurality of these are bonded. Examples of the divalent aliphatic hydrocarbon group include a linear or branched alkylene group such as a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group (for example, , Alkylene groups having 1 to 6 carbon atoms) and the like. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene group, 1,3-cyclopentylene group, 1,2-cyclohexylene group, 1,3-cyclohexylene group, And divalent cycloalkylene groups such as 1,4-cyclohexylene group.

Specific examples of the alicyclic epoxy compound (A) include compounds represented by the following formula (a1).

  In the above formula (a1), R represents an epoxidized cyclic olefin group. Two Rs may be the same or different. X represents a single bond or a divalent hydrocarbon group. Examples of the epoxidized cyclic olefin group as R and the divalent hydrocarbon group as X are the same as those described above. Examples of the compound represented by the formula (a1) include compounds in which two Rs are both cyclohexene oxide groups (particularly, the carbon atom at the 4-position of the two cyclohexene oxide groups (the two carbon atoms forming the epoxy group). A compound in which the positions are defined as the 1-position and 2-position) by a single bond or a divalent hydrocarbon group.

  In addition, in the curable composition of this invention, an alicyclic epoxy compound (A) can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  Although content (blending amount) of the alicyclic epoxy compound (A) in the curable composition of the present invention is not particularly limited, it is 10 to 60 with respect to the total amount (total amount) (100% by weight) of the curable composition. % By weight is preferable, more preferably 15 to 55% by weight, and still more preferably 20 to 50% by weight. When the content of the alicyclic epoxy compound (A) is less than 10% by weight, the curability of the curable composition may be insufficient. On the other hand, if the content of the alicyclic epoxy compound (A) exceeds 60% by weight, it may be difficult to impart high refractive index and low Abbe number optical characteristics to the cured product.

  The ratio of the alicyclic epoxy compound (A) to the total amount (100% by weight) of the alicyclic epoxy compound (A) and the cationically polymerizable compound (B) having an aromatic ring is not particularly limited, but is preferably 10 to 60% by weight. More preferably, it is 15-55 weight%, More preferably, it is 20-50 weight%. When the ratio is less than 10% by weight, the curability of the curable composition may be insufficient. On the other hand, if the ratio exceeds 60% by weight, it may be difficult to impart high refractive index and low Abbe number optical characteristics to the cured product.

[Cationically polymerizable compound having an aromatic ring (B)]
The cation polymerizable compound (B) having an aromatic ring in the curable composition of the present invention (hereinafter sometimes simply referred to as “cation polymerizable compound (B)” or “component (B)”) is contained in the molecule. It is a compound having at least one aromatic ring and at least one cationically curable functional group (cationically polymerizable functional group). By including the cationically polymerizable compound (B), the cured product obtained by curing the curable composition of the present invention has particularly high heat resistance, high transparency, high refractive index, and low Abbe number. There exists a tendency which can provide an optical characteristic efficiently.

  The aromatic ring possessed by the cationically polymerizable compound (B) is not particularly limited. For example, an aromatic monocyclic hydrocarbon ring such as a benzene ring; aromatic condensation such as a naphthalene ring, an anthracene ring, a fluorene ring, and a pyrene ring Examples thereof include aromatic hydrocarbon rings such as polycyclic hydrocarbon rings. Examples of the aromatic ring include aromatic heterocyclic rings such as a pyridine ring, furan ring, pyrrole ring, benzofuran ring, indole ring, carbazole ring, quinoline ring, benzimidazole ring, and quinoxaline ring. Among them, the aromatic ring is preferably an aromatic hydrocarbon ring, more preferably a benzene ring or a fluorene ring, and from the viewpoint of easily imparting high refractive index and low Abbe number optical characteristics to the cured product. A fluorene ring is particularly preferred.

  One or more substituents may be bonded to the aromatic ring of the cationic polymerizable compound (B). As said substituent, the thing similar to the substituent which may be couple | bonded with the aliphatic hydrocarbon ring which forms the above-mentioned cyclic olefin group is illustrated, for example. The cationically polymerizable compound (B) may have one type of aromatic ring or may have two or more types.

  The number of aromatic rings in the molecule of the cationically polymerizable compound (B) may be one or more, and is not particularly limited, but is preferably 1 to 10, more preferably 2 to 8.

  Examples of the cationically curable functional group possessed by the cationically polymerizable compound (B) include known or commonly used functional groups having cationic curable properties (cationic polymerizable properties), and are not particularly limited. For example, an epoxy group, an oxetanyl group, Examples thereof include cyclic ether groups such as a tetrahydrofuranyl group and an oxazolinyl group; vinyl group-containing groups such as a vinyl ether group and a styryl group; and groups containing at least these groups. Among these, the cation-curable functional group is preferably an alicyclic epoxy group (epoxidized cyclic olefin group), a glycidyl group, or an oxetanyl group from the viewpoint of reactivity with the alicyclic epoxy compound (A). The cationically polymerizable compound (B) may have one kind of cationically curable functional group, or may have two or more kinds.

  The number of cationically curable functional groups in the molecule of the cationically polymerizable compound (B) may be one or more, and is not particularly limited, but is preferably 2 to 10, more preferably 2 to 4. .

  Among the cationically polymerizable compounds (B), examples of the epoxy compound having an aromatic ring include bisphenol A type epoxy compounds (such as diglycidyl ether of bisphenol A or an alkylene oxide adduct thereof), bisphenol F type epoxy compounds (bisphenol F). Or diglycidyl ether of an alkylene oxide adduct thereof), biphenol type epoxy compound, phenol novolac type epoxy compound, cresol novolak type epoxy compound, cresol type epoxy compound, cresol novolak type epoxy compound of bisphenol A, polyphenol type epoxy compound, bromine Bisphenol A epoxy compound, brominated bisphenol F epoxy compound, hydroquinone diglycidyl ether, resorcin diglycidyl ether Terephthalic acid diglycidyl ester, phthalic acid diglycidyl ester, addition reaction product of terminal carboxylic acid polybutadiene and bisphenol A type epoxy resin, naphthalene type epoxy compound (epoxy compound having naphthalene ring), epoxy compound having fluorene ring, etc. Can be mentioned. Moreover, as an epoxy compound which has the said aromatic ring, the alicyclic epoxy compound etc. which have the aromatic skeleton disclosed by Unexamined-Japanese-Patent No. 2009-179568 can be used, for example.

The epoxy compound having an aromatic ring is particularly preferably a compound represented by the following formula (b1) from the viewpoint of the high refractive index and low Abbe number of the cured product.

In formula (b1), R ^{1 to} R ⁵ and R ^{7 to} R ¹¹ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, and hexyl group. It is done. Especially, as R < ¹ > -R < ⁵ >, R < ⁷ > -R < ¹¹ >, a hydrogen atom and a C1-C3 alkyl group are preferable, More preferably, it is a hydrogen atom.

In formula (b1), ring Z ¹ and ring Z ² are the same or different and represent an aromatic carbocyclic ring (aromatic hydrocarbon ring). 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. Among these, as the aromatic carbocycle, a benzene ring, a naphthalene ring and the like are preferable.

In the formula (b1), the fluorene ring, the ring Z ¹ and the ring Z ² represented by the formula (b1) may have a substituent. Examples of the substituent include alkyl groups such as a methyl group, an ethyl group, a propyl group, and an isopropyl group (eg, a C _1-6 alkyl group, preferably a methyl group); a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group ( For example, C _5-8 cycloalkyl group etc.); Aryl group such as phenyl group, naphthyl group (eg C _6-15 aryl group etc.); Aralkyl group such as benzyl group (eg C _7-16 aralkyl group etc.) An acyl group such as an acetyl group, a propionyl group or a benzoyl group (for example, a C _1-10 acyl group); an alkoxy group such as a methoxy group, an ethoxy group, a propyloxy group or an isopropyloxy group (for example, a C _1-6 alkoxy group) Group); alkoxycarbonyl group such as methoxycarbonyl group and ethoxycarbonyl group (eg C _1-4 alkoxy-carbonyl group etc.); cyano group A carboxyl group; a nitro group; an amino group; a substituted amino group (for example, a mono- or di-C _1-4 alkylamino group); a halogen atom such as a fluorine atom or a chlorine atom;

In formula (b1), R ⁶ and R ¹² are the same or different and represent an alkylene group having 1 to 10 carbon atoms. Examples of the alkylene group in R ⁶ and R ¹² include a linear or branched alkylene group having 1 to 10 carbon atoms such as a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, and a hexamethylene group. Is mentioned. Especially, as said alkylene group, C2-C6 alkylene groups, such as ethylene group, a propylene group, and a trimethylene group, are preferable, More preferably, it is a C2-C3 alkylene group.

  In formula (b1), p1 and p2 are the same or different and are integers of 0 or more, preferably an integer of 0 to 4, and more preferably an integer of 1 to 4 in terms of lower viscosity and excellent fluidity. .

  In addition, as a compound represented by a formula (b1), commercial items, such as brand name "PG-100" and "EG-200" (above, Osaka Gas Chemical Co., Ltd. product), can also be used, for example. .

  Among the cationic polymerizable compounds (B), examples of the oxetane compound having an aromatic ring include 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, 3-ethyl-3- [ (Phenoxy) methyl] oxetane, 4,4′-bis [3-ethyl- (3-oxetanyl) methoxymethyl] biphenyl, novolac-type oxetane resin and the like.

  A commercial item can also be used as a cationically polymerizable compound (B). Among the cationically polymerizable compounds (B), as commercial products of bisphenol A type epoxy compounds, for example, trade names “jER828”, “jER828”, “jER828EL”, “jER828XA”, “jER834” (above, Mitsubishi Chemical Corporation) Product name “Epicron 840”, “Epicron 840-S”, “Epicron 850”, “Epicron 850-S”, “Epicron 850-LC” (above, manufactured by DIC Corporation) and the like. Moreover, as a commercial item of the epoxy compound which has a naphthalene ring in a molecule | numerator among cationically polymerizable compounds (B), for example, brand name "Epicron HP4032", "HP4032D", "HP4700", "HP4710", "HP4770" “HP5000” (manufactured by DIC Corporation) and the like. Furthermore, as a commercial item of the epoxy compound which has a fluorene ring in a molecule | numerator among cationically polymerizable compounds (B), for example, brand name "PG-100", "EG-200", "EG-250" (above, Osaka Product name “ONCOAT EX-1010”, “ONCOAT EX-1011”, “ONCOAT EX-1012”, “ONCOAT EX-1020”, “ONCOAT EX-1030”, “Oncoat EX-1040”, “Oncoat EX-1050”, “Oncoat EX-1051” (manufactured by Nagase Sangyo Co., Ltd.) and the like can be mentioned. Furthermore, as a commercial item of the oxetane compound which has an aromatic ring in a molecule | numerator among cationically polymerizable compounds (B), brand name "OXT-121", "OXT-211" (above, Toagosei Co., Ltd. product), for example. Trade name “ETERRNACOLL OXBP” (manufactured by Ube Industries, Ltd.) and the like.

  In the curable composition of the present invention, the cationically polymerizable compound (B) can be used alone or in combination of two or more.

  The content (blending amount) of the cationic polymerizable compound (B) in the curable composition of the present invention is not particularly limited, but is 40 to 90% by weight with respect to the total amount (100% by weight) of the curable composition. More preferably, it is 40-80 weight%, More preferably, it is 45-75 weight%. If the content of the cationic polymerizable compound (B) is less than 40% by weight, it may be difficult to impart high refractive index and low Abbe number optical characteristics to the cured product. On the other hand, when the content of the cationic polymerizable compound (B) exceeds 90% by weight, it may be difficult to obtain the effect of improving the rapid curability and the shape stability at the time of curing.

  The ratio of the total amount of component (A) and component (B) to the total amount (100% by weight) of the curable composition of the present invention is not particularly limited, but is 80% by weight or more (for example, 80% by weight or more, 100% by weight). Less than), more preferably 90% by weight or more (for example, 90 to 98% by weight). When the ratio is less than 80% by weight, various kinds of fast curability and shape stability at the time of curing of the curable composition, heat resistance of the cured product and optical physical properties (high transparency, high refractive index, low Abbe number) It may be difficult to control the characteristics in a balanced manner.

[Thermal cationic curing agent (C)]
The thermal cationic curing agent (C) (hereinafter sometimes referred to as “component (C)”) in the curable composition of the present invention is a cationic curable compound (cationic curable functional group) contained in the curable composition by heating. A compound having a group; for example, a polymerization reaction (curing reaction) of an alicyclic epoxy compound (A), a cationic polymerizable compound (B), a release agent having one or more cationic curable functional groups in the molecule, and the like. It is a compound that has the function of starting or proceeding. As the thermal cation curing agent (C), known or commonly used compounds having the above-mentioned functions can be used, and are not particularly limited. For example, cationic species are generated by heating, whereby polymerization of a curable compound ( Examples thereof include a thermal cationic polymerization initiator for initiating curing.

  Examples of the thermal cationic curing agent (C) include thermal cationic polymerization initiators such as aryl diazonium salts, aryl iodonium salts, aryl sulfonium salts, and allene-ion complexes. Examples of the thermal cation curing agent (C) include a compound of a chelate compound of a metal such as aluminum or titanium and acetoacetic acid or a diketone and a silanol such as triphenylsilanol, or a metal such as aluminum or titanium. Examples thereof include thermal cationic polymerization initiators such as a compound of a chelate compound with acetoacetic acid or diketones and a compound of phenols such as bisphenol S. Examples of the thermal cationic curing agent (C) include trade names “PP-33”, “CP-66”, “CP-77” (above, manufactured by ADEKA Corporation); trade name “FC-509” (3M). Product name “UVE1014” (manufactured by GE); product names “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L”, “Sun-Aid SI-110L”, “Sun-Aid SI-” Commercially available products such as “150L” (manufactured by Sanshin Chemical Industry Co., Ltd.); trade name “CG-24-61” (manufactured by BASF) can also be used.

  Especially, it is preferable to use what can control the hardening start temperature of the below-mentioned curable composition of this invention as 60-150 degreeC (more preferably 80-120 degreeC) as a thermal cation hardening | curing agent (C).

  In the curable composition of the present invention, the thermal cationic curing agent (C) can be used alone or in combination of two or more.

  The content (blending amount) of the thermal cation curing agent (C) in the curable composition of the present invention is not particularly limited, but is 0 with respect to 100 parts by weight of the total amount of the cationic curable compound contained in the curable composition. 0.001 to 10 parts by weight is preferable, more preferably 0.01 to 5 parts by weight, and still more preferably 0.1 to 3 parts by weight. When the content is less than 0.001 part by weight, in some cases, such as when a relatively thick cured product is formed, defective curing may easily occur. On the other hand, when the content exceeds 10 parts by weight, physical properties such as heat resistance of the cured product may be lowered, or the cost may be disadvantageous.

[Antioxidant]
The curable composition of the present invention may further contain an antioxidant. As the antioxidant, a known or conventional compound that can be used as an antioxidant can be used, and is not particularly limited. For example, a phenolic antioxidant (phenolic compound), a phosphorus antioxidant (phosphorus) Compounds), sulfur-based antioxidants (sulfur-based compounds), and the like.

  Examples of the phenol-based antioxidant include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β- ( Monophenols such as 3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl) -6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [ 1,1-dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,10-tetraoxas B Bisphenols such as [5.5] undecane; 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6 -Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, Bis [3,3′-bis (4′-hydroxy-3′-t-butylphenyl) butyric acid] glycol ester, 1,3,5-tris (3 ′, 5′-di-t-butyl-4 '-Hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione, polymer type phenols such as tocophenol, and the like.

  Examples of the phosphorus antioxidant include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris (2,4-di-t -Butylphenyl) phosphite, cyclic neopentanetetraylbis (octadecyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis ( 2,4-di-t-butyl-4-methylphenyl) phosphite, bis [2-t-butyl-6-methyl-4- {2- (octadecyloxycarbonyl) ethyl} phenyl] hydrogen phosphite, etc. Phosphites; 9,10 Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene Examples include oxaphosphaphenanthrene oxides such as -10-oxide.

  Examples of the sulfur-based antioxidant include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate. It is done.

  Among these, as the antioxidant, a phenolic antioxidant is preferable. In addition, in the curable composition of this invention, antioxidant can also be used individually by 1 type and can also be used in combination of 2 or more type.

  The content (blending amount) of the antioxidant in the curable composition of the present invention is not particularly limited, but is 0.001 to 15 with respect to 100 parts by weight of the total amount of the cationic curable compound contained in the curable composition. A weight part is preferable, More preferably, it is 0.01-10 weight part, More preferably, it is 0.1-5 weight part. When the content is less than 0.001 part by weight, suppression of deterioration such as oxidation may be insufficient depending on applications. On the other hand, when the content exceeds 15 parts by weight, physical properties such as heat resistance of the cured product may be lowered, or the cost may be disadvantageous.

[Release agent]
The curable composition of the present invention may further contain a release agent. The release agent may be a known or conventional compound that can be used as a release agent, and is not particularly limited. Examples thereof include (poly) oxyalkylene alkyl phosphate compounds, fluorine compounds (fluorine release agents). ), A silicone compound, a compound having a long-chain alkyl group, a polyalkylene wax, an amide wax, a polytetrafluoroethylene powder, and the like. Among these, from the viewpoint of not impairing the transparency, a release agent having one or more cationic curable functional groups in the molecule is preferable, and more preferably a fluorine compound having one or more cationic curable functional groups in the molecule ( Fluorine-based mold release agent).

  The cation curable functional group possessed by the fluorine compound having one or more cation curable functional groups in the molecule includes cyclic ether groups such as epoxy group, oxetanyl group, tetrahydrofuranyl group, oxazolinyl group; vinyl ether group, styryl group. Vinyl group-containing groups such as: groups containing at least these groups, and the like. Among these, as the cationic curable functional group, a cyclic ether group is preferable, and an epoxy group is more preferable. In addition, the number of the cation curable functional group which the fluorine compound which has a 1 or more cation curable functional group in the said molecule | numerator should just be 1 or more (for example, 1-4), and is not specifically limited. Moreover, when it has a some cation curable functional group, it may have only 1 type of cation curable functional group, and may have 2 or more types of cation curable functional groups.

Specific examples of the fluorine compound having one or more cationically curable functional groups in the molecule include, for example, a fluorine-substituted hydrocarbon having an epoxy group (epoxy group-containing fluorine-substituted hydrocarbon), and the like. Specific examples include compounds represented by the following formula (i) (monofunctional epoxy compounds having fluoroalkyl).

R in the above formula (i) represents an integer of 1 to 15. Moreover, s shows the integer of 1-5. Y represents a hydrogen atom, a fluorine atom, or a fluoroalkyl group. Examples of the fluoroalkyl group include alkyl groups having 1 to 20 carbon atoms (preferably 1 to 10) in which part or all of hydrogen atoms are substituted with fluorine atoms [for example, trifluoromethyl group and perfluoroisopropyl group. Etc.]. In addition, — (CH ₂ ) _r — in the formula (i) may be one in which a part of hydrogen atoms is substituted with a hydroxyl group, or may contain an ether bond in the middle. Good. More specifically, examples of the compound represented by the formula (i) include 3-perfluorohexyl-1,2-epoxypropane.

  Examples of the release agent include trade names “E-1430”, “E-1630”, “E-1830”, “E-2030”, “E-3430”, “E-3630”, “E- 3830 "," E-4030 "," E-5244 "," E-5444 "," E-5644 "," E-5844 "(fluorine-based mold release agent, manufactured by Daikin Industries, Ltd.) Commercial products can also be used. In addition, in the curable composition of this invention, a mold release agent can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  The content (blending amount) of the release agent in the curable composition of the present invention is not particularly limited, but is 0 with respect to 100 parts by weight of the total amount of the alicyclic epoxy compound (A) and the cationic polymerizable compound (B). 0.01 to 10 parts by weight is preferable, and 0.1 to 5 parts by weight is more preferable. If the content of the release agent is less than 0.01 parts by weight, it may not be possible to release from the mold during molding. On the other hand, when content of a mold release agent exceeds 10 weight part, transparency of a curable composition may be impaired.

[Additive]
The curable composition of this invention may contain other components, such as an additive, as needed other than the above-mentioned component. The additive includes known or commonly used additives, and is not particularly limited. For example, metal oxide particles, rubber particles, silicone-based or fluorine-based antifoaming agents, silane coupling agents, fillers, plastics Agents, leveling agents, antistatic agents, flame retardants, colorants, ultraviolet absorbers, ion adsorbers, pigments and the like. The content (blending amount) of these various additives is not particularly limited, but is preferably 5% by weight or less (for example, 0 to 5% by weight) with respect to the curable composition (100% by weight). . In addition, the curable composition of the present invention may contain a solvent, but if it is too much, bubbles may be generated in the cured product, so 10% by weight or less (100% by weight) with respect to the curable composition (100% by weight) ( For example, it is preferably 0 to 10% by weight), more preferably 1% by weight or less.

  Cationic polymerizable compound (cationic curable functional group) relative to the total amount (100% by weight) of the curable compound (a compound having a radical curable functional group or a compound having a cationic curable functional group) contained in the curable composition of the present invention The ratio of the total amount of the compound having, for example, an alicyclic epoxy compound (A), a cationic polymerizable compound (B), a release agent having one or more cationic curable functional groups in the molecule, etc. is not particularly limited. However, 80 weight% or more (for example, 80 to 100 weight%) is preferable, More preferably, it is 90 weight% or more. When the ratio is less than 80% by weight, the curing shrinkage rate at the time of curing may be too large, or it may be difficult to ensure the transparency of the cured product.

  Although the curable composition of the present invention is not particularly limited, for example, a predetermined amount of an alicyclic epoxy compound (A), a cationic polymerizable compound (B), and a thermal cationic curing agent (C), and further oxidized if necessary. It can be prepared by blending an inhibitor, a release agent, various additives and the like, and stirring and mixing while removing bubbles under vacuum as necessary. The temperature at the time of stirring and mixing is preferably about 10 to 60 ° C, for example. For stirring and mixing, a known or conventional device such as a rotating / revolving mixer, a single or multi-screw extruder, a planetary mixer, a kneader, or a dissolver can be used.

Although the hardening start temperature of the curable composition of this invention is not specifically limited, 60-150 degreeC is preferable, More preferably, it is 80-120 degreeC. When the curing start temperature of the curable composition of the present invention is less than 60 ° C, the storage stability is poor and may not be suitable for use in a room temperature environment (25 ° C). The “curing start temperature of the curable composition” refers to the rising temperature (when the heat of reaction is measured using a DSC (differential scanning calorimeter) under the following conditions for the curable composition of the present invention ( It means the temperature at which the rise from the baseline starts.
(DSC measurement conditions)
・ Measurement atmosphere: Nitrogen (Flow rate: 50 mL / min)
・ Measurement temperature: 30 ~ 300 ℃
-Temperature rising condition: 20 ° C./min Note that the curing start temperature of the curable composition of the present invention is, for example, the composition of the curable composition (for example, the type of the thermal cationic curing agent (C); in particular, the alicyclic epoxy It can be controlled by a combination of the compound (A) and the cationic polymerizable compound (B) and the thermal cation curing agent (C).

  By curing the curable composition of the present invention, a cured product (sometimes referred to as “cured product of the present invention”) is obtained. Curing (curing reaction) of the curable composition of the present invention can be performed by, for example, heat treatment. In addition, when performing heat processing, as the temperature, it can adjust suitably according to the kind etc. of component (A)-(C) with which it uses for reaction, Although it does not specifically limit, 100-200 degreeC is preferable, More Preferably it is 120-160 degreeC. Furthermore, light irradiation may be used in combination in order to further advance the curing reaction. When performing light irradiation, as the light source, for example, a mercury lamp, a xenon lamp, a carbon arc lamp, a metal halide lamp, sunlight, an electron beam source, a laser light source, or the like can be used.

  The internal transmittance at 400 nm (internal transmittance of light having a wavelength of 400 nm) [converted to a thickness of 0.5 mm] of the cured product of the present invention is not particularly limited, but is preferably 70% or more (for example, 70 to 100%). Preferably it is 75% or more, More preferably, it is 80% or more, Most preferably, it is 85% or more.

  The refractive index at 589 nm (refractive index of light having a wavelength of 589 nm) (25 ° C.) of the cured product of the present invention is not particularly limited, but is preferably 1.58 or more, more preferably 1.60 or more.

  Although the Abbe number of the hardened | cured material of this invention is not specifically limited, 35 or less is preferable, More preferably, it is 30 or less, More preferably, it is 27 or less.

  Although the glass transition temperature (glass transition point) (Tg) of the hardened | cured material of this invention is not specifically limited, 100 degreeC or more (for example, 100-200 degreeC) is preferable, More preferably, it is 140 degreeC or more. If the glass transition temperature is less than 100 ° C., the heat resistance of the cured product may be insufficient depending on the use mode. The glass transition temperature of the cured product can be measured by, for example, various thermal analyzes [DSC (differential scanning calorimeter), TMA (thermomechanical analyzer), etc.], dynamic viscoelasticity measurement, and the like. It can be measured by the measurement method described in 1.

  Although the linear expansion coefficient ((alpha) 1) in below the glass transition temperature of the hardened | cured material of this invention is not specifically limited, 40-100 ppm / K is preferable, More preferably, it is 40-90 ppm / K. Moreover, although the linear expansion coefficient ((alpha) 2) above the glass transition temperature of the hardened | cured material of this invention is not specifically limited, 90-150 ppm / K is preferable, More preferably, it is 90-130 ppm / K. The linear expansion coefficients α1 and α2 of the cured product can be measured by, for example, TMA, and more specifically, can be measured by the measuring method described in the examples.

  The curable composition of the present invention is excellent in rapid curability and shape stability at the time of curing, and has high heat resistance, high transparency, high refractive index, and low Abbe number optical characteristics by curing. A cured product can be formed. For this reason, the curable composition of this invention can be preferably used especially as a material (composition for optical member formation) for forming an optical member. That is, the said optical member is an optical member containing the hardened | cured material obtained by hardening the curable composition (composition for optical member formation) of this invention. Examples of the optical member include members that exhibit various optical functions such as light diffusivity, light transmission, and light reflectivity, and devices and devices that use the optical functions (collectively, “optical” And the like. Specifically, as the optical member, for example, a color filter, a color filter protective film, a TFT flattening film, a substrate material, a light guide plate, a prism sheet, a polarizing plate (polarizing film), a retardation plate (a liquid crystal display device) Retardation film), viewing angle correction film, polarizer protective film, various coating materials (coating agent), adhesive material (adhesive agent), sealing material (sealing agent), etc .; mold of optical semiconductor element in optical semiconductor display device Materials (molding agents), sealing materials (sealing agents), front glass protective films, substitute materials for front glass, various coating agents, adhesives (adhesives), etc .; antireflection films for plasma display panels, optical correction films , Housing material, Front glass protective film, Front glass alternative material, Various coating materials (Coating agent), Adhesion (Adhesive) etc .; substrate material in plasma address liquid crystal display, light guide plate, prism sheet, polarizing plate, retardation plate, viewing angle correction film, polarizer protective film, various coating materials (coating agent), adhesive material (adhesive) ) Etc .; protective film for front glass in organic electroluminescence display, substitute material for front glass, various coating materials (coating agent), adhesive (adhesive), etc .; various film substrates in field emission display, protective film for front glass, Alternative materials for front glass, various coating materials (coating agents), adhesive materials (adhesive agents) and the like can be mentioned.

  Examples of the optical member include optical members used in the field of optical recording [eg CD / CD-ROM, CD-R / RW, DVD-R / DVD-RAM, MO / MD, PD (phase change] Disc), Blu-Ray, disc substrate materials for optical cards; pickup lenses; light receiving sensor parts; protective films; various coating materials (coating agents), adhesives (adhesives, etc.)], optics used in the field of optical equipment Materials [For example, steel camera lens materials, finder prisms, target prisms, finder covers, light receiving sensor parts, various coating materials (coating agents), adhesives (adhesives), etc .; video camera photography lenses, finder, various coatings Materials (coating agents), adhesives (adhesives), etc .; projection television projection , Protective films, various coating materials (coating agents), adhesives (adhesives), etc .; lens materials for optical sensing devices, various films, various coating materials (coating agents), adhesives (adhesives), etc .; smartphones, etc. Camera lenses, various coating materials (coating agents), adhesives (adhesives), etc.] mounted on portable terminals, optical members used in the field of optical components [for example, fibers around optical switches in optical communication systems] Materials, lenses, waveguides, elements, various coating materials (coating agents), adhesives (adhesives), etc .; optical fiber materials around the optical connectors, ferrules, various coating materials (coating agents), adhesives (adhesives), etc .; Optical passive components, lenses in optical circuit components, waveguides, various coating materials (coating agents), adhesives (adhesion) ) Etc .; Substrate materials around optoelectronic integrated circuits (OEIC), fiber materials, various coating materials (coating agents), adhesives (adhesives, etc.)], optical members used in the field of optical fibers [eg lighting for decorative displays Light guides, industrial sensors, displays / signs, etc., optical fibers for communication infrastructure and home digital devices, various coating materials (coating agents), adhesives (adhesives, etc.)], light Optical members used in the field of electronic functional organic materials [for example, organic EL element peripheral materials, organic photorefractive elements, light-to-light conversion devices, optical amplification elements, optical arithmetic elements, organic solar cell peripheral substrate materials, fibers Materials, element sealing materials (sealing agents), various coating materials (coating agents), adhesives (adhesives), etc.] The

  Furthermore, as the optical member, for example, an optical member used in the field of automobiles and transportation equipment [for example, lamp materials such as automotive headlamps, tail lamps, indoor lamps, lamp reflectors, lamp lenses, exterior plates, interior panels, etc. Various interior and exterior products, glass substitutes, various coating materials (coating agents), adhesives (adhesives), etc .; exterior parts for railway vehicles, glass substitutes, various coating materials (coating agents), adhesives (adhesives) Aircraft exterior parts, glass substitutes, various coating materials (coating agents), adhesives (adhesives, etc.)], optical members used in the construction field [for example, glass interlayers, glass substitutes, various coatings] Materials (coating agents), adhesives (adhesives, etc.)], optical members used in the agricultural field [for example, film for house covering, Seed coating material (coating agent), such as an adhesive material (adhesive) or the like can be mentioned.

  By using the above-mentioned optical member having a cured product obtained by curing the curable composition (composition for forming an optical member) of the present invention, an optical device having the optical member can be obtained. As the optical device, various optical devices including the optical member (for example, a liquid crystal display device, an optical semiconductor display device, a plasma display panel, an organic electroluminescence display, a field emission display, a mobile terminal such as a smartphone or a mobile phone). There is no particular limitation.

EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited by these Examples. Example 3 is described as a reference example.

Examples 1-3, Comparative Examples 1-3
About each component of Table 1, the curable composition was obtained by stirring and mixing at normal temperature (25 degreeC) using the autorotation revolution mixer. In addition, the unit of the compounding quantity described in Table 1 is a weight part.

Abbreviations in Table 1 will be described.
[Curable compound]
PG-100: Fluorene epoxy compound (Osaka Gas Chemical Co., Ltd., trade name “PG-100”)
EG-200: Fluorene-based epoxy compound (trade name “EG-200” manufactured by Osaka Gas Chemical Co., Ltd.)
827: Bisphenol A type epoxy compound (Mitsubishi Chemical Corporation, trade name “jER827”)
C1: 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate C2: 3,4,3 ′, 4′-diepoxybicyclohexyl EA-F5503: fluorene acrylic compound (Osaka Gas Chemical Co., Ltd.) Product name "Ogsol EA-F5503")
IRR-214K: Alicyclic acrylic compound (manufactured by Daicel-Cytec Co., Ltd., trade name “IRR-214K”)
[Thermal cationic polymerization initiator]
SI-100L: Aromatic sulfonium salt (manufactured by Sanshin Chemical Industry Co., Ltd., trade name “Sun-Aid SI-100L)
[Thermal radical polymerization initiator]
Perhexa C: 1,1-di (t-butylperoxy) cyclohexane (manufactured by NOF Corporation, trade name “Perhexa C”, 1 minute half-life temperature: 153.8 ° C.)
〔Antioxidant〕
IRG1010: Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenol) propionate] (trade name “IRGANOX1010” manufactured by BASF AG)
〔Release agent〕
E-1630: 3-perfluorohexyl-1,2-epoxypropane (manufactured by Daikin Industries, Ltd., trade name “E-1630”)

[Preparation of cured product]
A cured product was prepared by the following procedure.
For the curable compositions obtained in Examples and Comparative Examples, after applying (casting) at 25 ° C. using an imprint molding machine (“NANOIMPRINTER NM-0501” manufactured by Meisho Kiko Co., Ltd.) The press shaft position was adjusted to a thickness of 0.5 mm, the temperature was raised to 180 ° C. at a temperature rising rate of 20 ° C./min, held at 180 ° C. for 5 minutes, cooled to 80 ° C., and then released. The obtained cured product (referred to as “primary cured product”) was heated in an oven preheated to 180 ° C. for 30 minutes to obtain a cured product (referred to as “secondary cured product”).

  The following various measurements were performed about the curable composition obtained by the Example and the comparative example, and its hardened | cured material.

[viscosity]
About the curable composition obtained by the Example and the comparative example, the viscosity (Pa * s) in the temperature of 25 degreeC and the rotational speed of 20 / sec was measured using the rheometer ("PHYSICA UDS200" by Paar Physica). did.

[Curing rate]
About the curable composition obtained by the Example and the comparative example, using a differential scanning calorimeter ("Q2000" manufactured by TA Instruments Inc.), curing under the following temperature conditions in a nitrogen atmosphere The calorific value was measured, and this was defined as the calorific value of the curable composition. Subsequently, with respect to the primary cured product obtained above, the amount of heat generated under the same temperature conditions is measured at the central portion and the peripheral portion of the primary cured product (each obtained by cutting out the corresponding portion with a blade), and the average value thereof. Was defined as the heating value of the primary cured product. And the hardening rate was computed by the following formula.
Temperature condition: After holding at 50 ° C. for 3 minutes, the temperature is raised to 250 ° C. at a heating rate of 20 ° C./minute and held at 250 ° C. for 3 minutes. Calorific value) / (curing calorific value of curable composition)} × 100

[Curing start temperature]
About the curable composition obtained by the Example and the comparative example, using a differential scanning calorimeter ("Q2000" made by TA Instruments Inc.), the above-mentioned curing start temperature measurement under a nitrogen atmosphere The heating value of the curing (reaction heat amount) when heated under the conditions of the time was observed. In the chart of the amount of curing heat generated, the rising temperature of the curing heat generation (temperature at which the rising from the baseline starts) was measured as the curing start temperature.

[Internal transmittance]
The internal transmittance of the secondary cured product (thickness: 0.5 mm) obtained above was calculated by the following formula. The light transmittance at 400 nm (light transmittance of the secondary cured product) was measured using a spectrophotometer (“U-3900” manufactured by Hitachi High-Technologies Corporation). N in the following formula is a refractive index at 400 nm, and a value obtained by a refractive index measurement method described later is used.
Internal transmittance (400 nm) (%) = light transmittance at 400 nm (%) / (1-r) ²
r = {(n−1) / (n + 1)} ²

[Refractive index]
About the secondary hardened | cured material obtained above, the refractive index in 589 nm in 25 degreeC was measured by the method based on JISK7142 using the refractometer ("Model 2010" by a metricon company).

[Abbe number]
The Abbe number of the secondary cured product obtained above was calculated by the following formula.
Abbe number = (nd-1) / (nF-nC)
(In the formula, nd represents the refractive index at 589.2 nm, nF represents the refractive index at 486.1 nm, and nC represents the refractive index at 656.3 nm. In addition, as the value of the refractive index, the above-described refractive index measurement method is used. And the refractive index values obtained at each wavelength were used.)

[Volume shrinkage]
The volume shrinkage ratio (%) of the secondary cured product obtained above is the specific gravity (G1) of the curable composition at 25 ° C. and the specific gravity (G2) of the secondary cured product. After measurement using “SD-200L” manufactured by Shimadzu Corporation, calculation was performed using the following formula.
Volume shrinkage (%) = {(G2-G1) / G1 × 100}

[Glass-transition temperature]
The glass transition temperature (glass transition point) (Tg, ° C.) of the secondary cured product obtained above is compliant with JIS K7197 using a TMA measuring device (“TMA / SS100” manufactured by SII Nanotechnology). After measuring the coefficient of thermal expansion in a measurement temperature range of 30 to 250 ° C. under a nitrogen atmosphere at a rate of temperature increase of 5 ° C./minute, a tangent line is drawn on the curves before and after the glass transition point. Obtained from intersection of tangents.

[Linear expansion coefficient]
The linear expansion coefficient of the secondary cured product obtained above was measured using a TMA measuring device (“TMA / SS100” manufactured by SII Nanotechnology Co., Ltd.) under a nitrogen atmosphere by a method based on JIS K7197. After measuring the coefficient of thermal expansion in the measurement temperature range of 30 to 250 ° C. at a rate of temperature increase of 5 ° C./min, the slope of the straight line on the low temperature side from the glass transition point is α1, and the slope of the straight line on the high temperature side from the glass transition point is α2. Each was determined as a linear expansion coefficient.

[Heat resistance test (evaluation of yellowing resistance under reflow conditions)]
Using the table reflow oven (manufactured by Thin Apec), the secondary cured product obtained above was subjected to heat resistance tests under reflow conditions at a maximum temperature of 270 ° C. three times in succession based on the temperature profile described in the JEDEC standard. After the measurement, the light transmittance at 400 nm and the refractive index at 400 nm were measured by the measurement method described above to determine the internal transmittance after the heat resistance test. From the internal transmittance before and after the heat resistance test, the yellowing rate (%) was calculated by the following formula to evaluate the heat resistance. In addition, the heat resistance of hardened | cured material is so favorable that a yellowing rate is small.
Yellowing rate (%) = {(Internal transmittance before heat resistance test) − (Internal transmittance after heat resistance test)} / (Internal transmittance before heat resistance test) × 100

The obtained results are shown in Table 2.

  The curable composition and the cured product obtained in the examples were compared with the case where an alicyclic epoxy compound having an ester group was used as in Comparative Example 1, and fast curability (high curing rate) and heat resistance. It was recognized that it was excellent in performance. Further, as in Comparative Example 2, curing was not observed at all in the thermal cation curing system that does not include a compound having an alicyclic epoxy group. Further, the curable compositions obtained in the examples and the cured products thereof were found to have a small volume shrinkage ratio and excellent shape stability as compared with the thermal radical curing system as in Comparative Example 3.

  In particular, the curable composition of the present invention can be preferably used as a material for forming an optical member (an optical member-forming composition).

Claims (10)

A curable composition comprising an alicyclic epoxy compound (A) having no ester group, a cationic polymerizable compound (B) having an aromatic ring, and a thermal cationic curing agent (C),
The alicyclic epoxy compound (A) having no ester group is a compound having at least two epoxidized cyclic olefin groups,
The cationically polymerizable compound (B) having an aromatic ring is represented by the following formula (b1)

(Wherein R ^{1 to} R ⁵ and R ^{7 to} R ¹¹ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ring Z ¹ and ring Z ² are the same or different, R ⁶ and R ¹² are the same or different and each represents an alkylene group having 1 to 10 carbon atoms, and p1 and p2 are the same or different and are an integer of 0 or more. Ring Z ¹ and Ring Z ² may have a substituent)
A compound represented by
The content of the cationic polymerizable compound (B) having an aromatic ring is 40 to 90% by weight with respect to the total amount (100% by weight) of the curable composition ,
Curing start temperature is 60-115 degreeC, The curable composition characterized by the above-mentioned.   The curable composition according to claim 1, wherein the epoxidized cyclic olefin group is a group obtained by epoxidizing a cyclic olefin group having 5 to 12 carbon atoms.   The alicyclic epoxy compound (A) having no ester group is a compound having a structure in which at least two of the epoxidized cyclic olefin groups are bonded by a single bond or a divalent hydrocarbon group. The curable composition according to 1.   The content of the alicyclic epoxy compound (A) having no ester group is 10 to 60% by weight with respect to the total amount (100% by weight) of the curable composition. The curable composition as described. The curable composition according to any one of claims 1 to 4 , wherein an Abbe number of a cured product obtained by curing is 35 or less. Furthermore, the curable composition of any one of Claims 1-5 containing the mold release agent which has a cationic curable functional group. It is a composition for optical member formation, The curable composition of any one of Claims 1-6 . Cured product obtained by curing the curable composition according to any one of claims 1-7. An optical member having a cured product obtained by curing the curable composition according to claim 7 . An optical device comprising the optical member according to claim 9 .