TW201443095A - Curable composition for wafer level lens, manufacturing method for wafer level lens, wafer level lens, and optical device - Google Patents

Abstract

The purpose of the present invention is to provide a curable composition exhibiting excellent rapid-curing properties and shape stability during curing, and being cured to form a high-precision wafer level lens that has optical properties such as a low Abbe number, high refractivity, high transparency and high thermal resistance. The curable composition for a wafer level lens, according to the present invention, comprises: an alicyclic epoxy compound (A) that does not have an ester group; and a cationic polymeric compound (B) having an aromatic ring, wherein the alicyclic epoxy compound (A) that does not have an ester group comprises at least two epoxidized cyclic olefin groups.

Description

Cured composition for wafer level lens, method of manufacturing wafer level lens, wafer level lens, and optical device

The present invention relates to a curable composition suitable for molding a wafer-level lens (a curable composition for a wafer-level lens), a method of manufacturing a wafer-level lens using the curable composition for a wafer-level lens, and The wafer level lens obtained by the method and the optical device. The present application claims the priority of the Japanese Patent Application No. 2013-029690, filed on Jan. 19, 2013, and the Japanese Patent Application No. 2013-029688, filed on Jan.

In recent years, electronic products such as mobile phones, portable computers, personal portable information devices (PDAs), and digital cameras (DSCs) have been rapidly reduced in size, weight, and performance. With such market trends, lenses for cameras mounted on electronic products are also strongly required to be miniaturized, thinned, and lightweight, and wafer-level lenses have been increasingly used. Further, in terms of high performance, a resolution corresponding to a photographic element of at least about 8,000,000 to 10 megapixels is required, and a cemented lens (stacked wafer level lens) in which two or more lenses are laminated is used.

As for the materials constituting the wafer level lens, a review is being conducted on the use of a resin material in place of the previously used glass material. In the resin materials for such wafer level lenses, it is generally required to have a high permeability. The brightness and heat resistance are further required to control various optical characteristics to a specific equilibrium state (for example, a high refractive index and a low Abbe number). As the resin material for forming an optical member such as a wafer level lens, for example, the following resin composition is known.

Patent Document 1 discloses an alicyclic epoxy resin composition containing an aromatic skeleton, which is characterized in that it contains a specific aromatic skeleton-containing alicyclic ring, in terms of a resin composition for forming an optical member. Oxygen compounds, and cationic hardening catalysts. When the resin composition is used, both high refractive index and cationic hardening reactivity can be achieved (see Patent Document 1).

Further, Patent Document 2 discloses a resin composition for an optical member molded body, which is a resin composition containing an organic resin component containing an organic resin component having a molecular weight of 700 or more in a molecular weight distribution thereof in a specific ratio. And an organic resin component having a molecular weight of less than 700, the organic resin component comprising an aromatic epoxy compound, 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 each containing an alicyclic epoxy compound and a hydrogenated epoxy compound. And at least one of the group consisting of an aromatic epoxy compound, and the resin composition further contains a mold release agent. The resin composition is rich in workability, and the cured product obtained by curing the resin composition has high strength, and is excellent in workability such as no crack at the time of mold release (see Patent Document 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-179568

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-13667

However, in Patent Document 1, although the cation hardening reactivity is improved, the resin composition disclosed in the literature is insufficient in curability, and a problem of curing failure occurs when a cured product is obtained. Further, in the resin composition disclosed in Patent Document 2, since the curability is insufficient, the problem of curing failure occurs in the same manner. Therefore, in order to form a curable composition for a wafer-level lens (a hardenable composition for a wafer-level lens), the hardening speed is sought to be very fast (speed hardening), and it can be formed to have higher heat resistance and transparency. Sex hardened person. In particular, in the present case, a hardenable composition which is a thermal cation hardening system has not been obtained, and the hardening rate is fast, and a cured product having a low Abbe number can be formed.

In addition to the various properties (speed hardenability, heat resistance, transparency, high refractive index, and low Abbe number) of the curable composition for wafer-level lenses, in particular, in order to obtain high-precision crystals The circular lens also requires a small hardening shrinkage ratio and an excellent shape stability when a cured product is formed. Further, in the curable composition for a wafer-level lens, after the curing and molding are required, the obtained wafer-level lens is excellent in mold release property when it is released from the mold.

In particular, regarding the shape stability, it is required that, for example, even when the wafer level lens is subjected to an annealing treatment or the like and placed in a high temperature environment, no problem occurs in the lens shape. Specifically, when the curable composition is molded by a mold, there is usually a skew caused by the residual stress in the obtained cured product (molded product). In order to remove such skew, after the hardened material is taken out of the mold, it is preferably annealed ( Heat) treatment. However, by performing the annealing treatment, "sag" is likely to occur in the shape of the cured product, especially in the case of a wafer-level lens, which causes a deviation in the center position of the lens, and in the case where a plurality of lenses are laminated, an image is caused. The possibility of problems such as unclearness and reduced accuracy is increased.

Accordingly, an object of the present invention is to provide a curable composition which is excellent in quick-curing property and shape stability during curing, and which is cured to obtain high heat resistance, high transparency, high refractive index, and High-precision wafer-level lenses with optical properties such as low Abbe numbers.

Further, another object of the present invention is to provide a method for producing a wafer-level lens using the above-described curable composition for a wafer-level lens, which has high heat resistance, high transparency, high refractive index, and A high-precision wafer-level lens with optical characteristics such as low Abbe number and an optical device having the wafer-level lens.

In order to solve the problem of the above-mentioned problems, the present inventors have found that a curable composition having an alicyclic epoxy compound having a specific structure and a cationically polymerizable compound having a specific structure as an essential component has a rapid hardenability and shape at the time of curing. It is excellent in stability and, by hardening it, it can form a high-precision cured product with high heat resistance and high optical properties such as high transparency, high refractive index, and low Abbe number. It is suitable for use as a wafer-level lens. Materials, and completed the present invention.

That is, the present invention provides a curable composition for a wafer-level lens, which comprises an alicyclic epoxy compound (A) having no ester group, and a cationically polymerizable compound having an aromatic ring ( B) The curable composition, wherein the alicyclic epoxy compound (A) having no ester group is a compound having at least 2 epoxidized cyclic olefin groups.

Further, a curable composition for a wafer level lens as described above, wherein the epoxidized cyclic olefin group is an epoxidized group of a cyclic olefin group having 5 to 12 carbon atoms.

Further, a hardenable composition for a wafer level lens as described above, wherein the alicyclic epoxy compound (A) having no ester group has at least two epoxidized cyclic olefin groups as a single bond Or a compound of a structure in which a divalent hydrocarbon group is bonded.

Further, a curable composition for a wafer-level lens as described above, wherein the alicyclic epoxy compound (A) having no ester group is a compound represented by the following formula (a2): [In the formula (a2), X represents a single bond or a divalent hydrocarbon group].

Further, there is provided a curable composition for a wafer-level lens as described above, wherein the content of the alicyclic epoxy compound (A) having no ester group is relative to the total amount of the curable composition (100% by weight) , 10 to 60% by weight.

Furthermore, the curable composition for a wafer-level lens as described above, wherein the cationically polymerizable compound (B) having an aromatic ring has an alicyclic epoxy group, a glycidyl group, and an oxetanyl group. At least one cationically curable functional group in the group formed.

Further, a curable composition for a wafer level lens as described above, wherein the cationically polymerizable compound (B) having an aromatic ring is contained The amount is 40 to 90% by weight based on the total amount (100% by weight) of the curable composition.

Further, a curable composition for a wafer level lens as described above is provided, which comprises a thermal cation hardener (C).

Further, a curable composition for a wafer level lens as described above is provided, wherein the curing start temperature is 60 to 150 °C.

Further, the curable composition for a wafer-level lens as described above is provided, wherein the cured product obtained by the hardening has an Abbe number of 35 or less.

Further, a curable composition for a wafer level lens as described above, which comprises a release agent having a cationically curable functional group, is provided.

Further, the present invention provides a method of manufacturing a wafer level lens, which is characterized in that the curable composition for a wafer level lens as described above is subjected to a casting molding method or an injection molding method.

Furthermore, a method of manufacturing a wafer level lens as described above is provided, wherein the casting molding method comprises the steps of: Step 1a: preparing a wafer-level lens forming mold having one or more lens molds; Step 2a: crystallizing a step of contacting the curable composition for a circular lens with the wafer-level lens molding die; and step 3a: a step of curing the curable composition for the wafer-level lens by heating and/or light irradiation.

Furthermore, a method of fabricating a wafer level lens as described above is provided, wherein the casting method further comprises the step of: step 4a: a step of annealing the hardened wafer level lens with a curable composition.

Furthermore, a method of manufacturing a wafer level lens as described above is provided, wherein the casting method further comprises the step of: step 5a: cutting the hardened wafer level lens with a curable composition.

Furthermore, a method of manufacturing a wafer level lens as described above is provided, wherein the injection molding method comprises the steps of: step 1b: preparing a wafer-level lens forming mold having one or more lens molds; and step 2b: a step of emitting a curable composition for a wafer level lens into the wafer-level lens molding die; and step 3b: a step of curing the wafer-level lens with a curable composition by heating and/or light irradiation.

Furthermore, a method of fabricating a wafer level lens as described above is provided, wherein the injection molding method further comprises the step of: step 4b: annealing the cured wafer level lens with a curable composition.

Further, the present invention provides a wafer level lens sheet obtained by a method of manufacturing a wafer level lens as described above.

Further, the present invention provides a wafer level lens obtained by the method of manufacturing a wafer level lens as described above.

Further, the present invention provides an optical device loaded with a wafer level lens as described above.

Moreover, the present invention provides a laminated wafer level lens which is a laminate of a plurality of wafer level lenses, and at least has a hardenability composition for the wafer level lens of the wafer level lens constituting the laminate. Object The wafer level lens obtained by hardening and molding.

Moreover, the present invention provides a method of manufacturing a stacked wafer level lens, which is a method of manufacturing a stacked wafer level lens as described above, the method comprising the steps of: Step 1c: preparing a wafer level having one or more lens molds a step of molding a lens for the lens; a step 2c: a step of bringing the curable composition for the wafer level lens into contact with the mold for forming the wafer level lens; and 3c: the wafer level lens by heating and/or light irradiation a step of obtaining a wafer-level lens sheet by hardening a hardenable composition; and step 4c: a step of forming a wafer-level lens sheet layer comprising a plurality of wafer-level lens sheets of the wafer-level lens sheet; step 5c : a step of cutting the wafer level lens sheet laminate.

Furthermore, a method of manufacturing a stacked wafer level lens as described above is provided, wherein the step of step 3c and step 4c comprises the step of: step 6c: annealing the wafer level lens sheet.

Further, the present invention provides a wafer level lens sheet laminate obtained by laminating a plurality of wafer level lens sheets including the wafer level lens sheets described above.

Further, the present invention provides an optical device loaded with a laminated wafer level lens as described above.

That is, the present invention relates to the following:

[1] A curable composition for a wafer-level lens, which comprises a sclerosing epoxy compound (A) having no ester group and a cationic polymerizable compound (B) having an aromatic ring. Composition, which is not The alicyclic epoxy compound (A) having an ester group is a compound having at least two epoxidized cyclic olefin groups.

[2] The curable composition for a wafer-level lens 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 curable composition for a wafer-level lens according to [1] or [2], wherein the alicyclic epoxy compound (A) having no ester group has at least two epoxidized rings A compound having a structure in which an olefin group is bonded by a single bond or a divalent hydrocarbon group.

[4] The curable composition for a wafer-level lens according to any one of [1] to [3] wherein the alicyclic epoxy compound (A) having no ester group is the above formula (a2) In the compound [in the formula (a2), X represents a single bond or a divalent hydrocarbon group].

[5] The curable composition for a wafer-level lens according to any one of [1] to [4] wherein the content of the alicyclic epoxy compound (A) having no ester group is relative to hardenability The total amount (100% by weight) of the composition is 10 to 60% by weight.

[6] The curable composition for a wafer-level lens according to any one of [1] to [5] wherein the alicyclic epoxy compound (A) having no ester group is relative to a fat having no ester group The ratio of the total amount (100% by weight) of the cyclic epoxy compound (A) and the cationically polymerizable compound (B) having an aromatic ring is 10 to 60% by weight.

[7] The curable composition for a wafer-level lens according to any one of [1] to [6] wherein the aromatic ring having the aromatic ring-containing cationically polymerizable compound (B) is an aromatic hydrocarbon ring .

[8] The curable composition for a wafer-level lens according to any one of [1] to [7] wherein the cationically polymerizable compound (B) having an aromatic ring has a number of aromatic rings in the molecule. It is 1~10.

[9] The curable composition for a wafer-level lens according to any one of [1] to [8] wherein the cationically polymerizable compound (B) having an aromatic ring has an alicyclic epoxy group and a shrinkage At least one cationically curable functional group in the group consisting of a glyceryl group and an oxetanyl group.

[10] The curable composition for a wafer-level lens according to any one of [1] to [9] wherein the cationically polymerizable compound (B) having an aromatic ring has a cationic hardening function in the molecule. The number of bases is 1~10.

The curable composition for a wafer-level lens according to any one of the above aspects, wherein the cationically polymerizable compound (B) having an aromatic ring is represented by the following formula (b1). Compound: [In the 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; and the ring Z ¹ and the ring Z ² are the same or different, An aromatic carbocyclic ring (aromatic hydrocarbon ring); R ⁶ and R ¹² are the same or different, and represent an alkylene group having 1 to 10 carbon atoms; p1 and p2 are the same or different and are an integer of 0 or more].

[12] The curable composition for a wafer-level lens according to any one of [1] to [11], wherein the content of the cationically polymerizable compound (B) having an aromatic ring is relative to the total of the curable composition. The amount (100% by weight) is 40 to 90% by weight.

[13] The curable composition for a wafer-level lens according to any one of [1] to [12] wherein the alicyclic epoxy compound (A) having no ester group and the cationic polymerizable property having an aromatic ring The ratio of the total amount of the compound (B) to the total amount (100% by weight) of the curable composition is 80% by weight or more and less than 100% by weight.

[14] The curable composition for a wafer-level lens according to any one of [1] to [13] further comprising a thermal cation hardener (C).

[15] The hardenable composition for a wafer-level lens according to [14], wherein the thermal cationic curing agent (C) is a thermal cationic polymerization initiator.

[16] The hardenable composition for a wafer-level lens according to [14] or [15], wherein a content (mixing amount) of the thermal cationic hardener (C) is relative to a cation contained in the curable composition The total amount of the curable compound is from 0.001 to 10 parts by weight based on 100 parts by weight.

[17] The curable composition for a wafer-level lens according to any one of [14] to [16] wherein the curing start temperature is 60 to 150 °C.

[18] The curable composition for a wafer level lens according to any one of [1] to [17] further comprising an antioxidant.

[19] The curable composition for a wafer-level lens according to [18], wherein the antioxidant is a phenol-based antioxidant.

[20] The hardenable composition for a wafer-level lens according to [18] or [19], wherein the content (mixing amount) of the antioxidant is relative to the hardenability group The total amount of the cationically curable compound contained in the product is 0.001 to 15 parts by weight based on 100 parts by weight.

[21] The curable composition for a wafer-level lens according to any one of [1] to [20] wherein the cured product obtained by curing the composition has an Abbe number of 35 or less.

[22] The curable composition for a wafer-level lens according to any one of [1] to [21] further comprising a release agent having a cationically curable functional group.

[23] The curable composition for a wafer-level lens according to [22], wherein the release agent has a number of cation-curable functional groups of from 1 to 4.

[24] The hardenable composition for a wafer-level lens according to [22] or [23] wherein the release agent is a fluorine-substituted hydrocarbon having an epoxy group.

[25] The curable composition for a wafer-level lens according to [24], wherein the fluorine-substituted hydrocarbon having an epoxy group is a compound represented by the following formula (i): [wherein r in the formula (i) represents an integer of 1 to 15; s represents an integer of 1 to 5; Y represents a hydrogen atom, a fluorine atom, or a fluoroalkyl group; -(CH ₂ ) _r - in the formula (i), It may be a part of a hydrogen atom which is substituted into a hydroxyl group, or may be an ether bond in the middle].

[26] The curable composition for a wafer-level lens according to any one of [22] to [25] wherein the content of the release agent (the amount of the release agent) is relative to an alicyclic ring having no ester group. The total amount of the epoxy compound (A) and the cationically polymerizable compound (B) having an aromatic ring is from 0.01 to 10 parts by weight per 100 parts by weight.

[27] The curable composition for a wafer-level lens according to any one of [1] to [26] wherein the total amount of the cationically polymerizable compound is relative to the total amount of the curable compound contained in the curable composition. The ratio of the amount (100% by weight) is 80 to 100% by weight.

[28] The curable composition for a wafer-level lens according to any one of [1] to [27] wherein the cured product obtained by curing the composition has an internal light transmittance at 400 nm [converted to a thickness of 0.5]. Mm] is 70~100%.

The hardenable composition for wafer-level lenses of any one of [1] to [28], wherein the cured product obtained by hardening the composition has a refractive index (25 ° C) of 5.8 nm or more of 1.58 or more. .

[30] The curable composition for a wafer-level lens according to any one of [1] to [29] wherein the cured product obtained by curing the composition has a glass transition temperature of 100 to 200 °C.

[31] The curable composition for a wafer-level lens according to any one of [1] to [30] wherein a linear expansion coefficient (α1) of the cured product obtained by curing the composition at a glass transition temperature or lower It is 40~100ppm/K.

[32] The curable composition for a wafer-level lens according to any one of [1] to [31] wherein a linear expansion coefficient (α2) of the cured product obtained by curing the composition at a glass transition temperature or higher It is 90~150ppm/K.

[33] A cured product obtained by curing the curable composition for a wafer-level lens according to any one of [1] to [32].

[34] The cured product according to [33], which has an internal light transmittance (converted to a thickness of 0.5 mm) of from 70 to 100% at 400 nm.

[35] The cured product according to [33] or [34], which has a refractive index (25 ° C) at 589 nm of 1.58 or more.

[36] The cured product according to any one of [33] to [35] wherein the glass transition temperature is from 100 to 200 °C.

[37] The cured product according to any one of [33] to [36] wherein the linear expansion coefficient (?1) below the glass transition temperature is 40 to 100 ppm/K.

[38] The cured product according to any one of [33] to [37], which has a linear expansion coefficient (?2) of 90 to 150 ppm/K or more at a glass transition temperature.

[39] The cured product according to any one of [33] to [38] wherein the Abbe number is 35 or less.

[40] A method of producing a wafer-level lens, characterized in that the curable composition for a wafer-level lens according to any one of [1] to [32] is subjected to a casting molding method or an injection molding method.

[41] The method for producing a wafer-level lens according to [40], wherein the casting molding method comprises the steps of: Step 1a: preparing a wafer-level lens molding mold having one or more lens molds; Step 2a a step of bringing the curable composition for the wafer-level lens into contact with the wafer-level lens molding die; and step 3a: a step of curing the curable composition for the wafer-level lens by heating and/or light irradiation.

[42] The method for producing a wafer-level lens according to [41], wherein the casting molding method further comprises the step of: step 4a: a step of annealing the hardened wafer-level lens with a curable composition.

[43] The method of manufacturing a wafer level lens according to [41] or [42], wherein the casting molding method further comprises the steps of: Step 5a: a step of cutting the hardened wafer level lens with a curable composition.

[44] The method for producing a wafer-level lens according to [40], wherein the injection molding method comprises the steps of: Step 1b: preparing a wafer-level lens molding die having one or more lens molds; Step 2b a step of ejecting a curable composition for a wafer-level lens into the wafer-level lens molding die; and step 3b: a step of hardening the wafer-level lens with a curable composition by heating and/or light irradiation .

[45] The method for producing a wafer-level lens according to [44], wherein the injection molding method further comprises the step of: step 4b: a step of annealing the hardened wafer-level lens with a curable composition.

[46] A wafer level lens sheet obtained by the method of manufacturing a wafer level lens as described in [41] or [42].

[47] A wafer level lens obtained by the method of manufacturing a wafer level lens according to any one of [40] to [45].

[48] The wafer level lens according to [47], wherein the internal light transmittance at 400 nm [converted to a thickness of 0.5 mm] is 70 to 100%.

[49] The wafer level lens according to [47] or [48], wherein the refractive index (25 ° C) at 589 nm is 1.58 or more.

[50] The wafer level lens according to any one of [47] to [49] wherein the glass transition temperature is 100 to 200 °C.

[51] The wafer level lens of any one of [47] to [50], wherein The coefficient of linear expansion (α1) below the glass transition temperature is 40 to 100 ppm/K.

[50] The wafer level lens according to any one of [47] to [51] wherein the linear expansion coefficient (?2) above the glass transition temperature is 90 to 150 ppm/K.

[53] The wafer level lens according to any one of [47] to [52] wherein the Abbe number is 35 or less.

[54] An optical device comprising the wafer level lens according to any one of [47] to [53].

[55] A laminate wafer level lens which is a laminate of a plurality of wafer level lenses, and which has at least one of [1] to [32] for a wafer level lens constituting the laminate. A wafer-level lens obtained by curing a cured composition of a wafer-level lens and molding it.

[56] The multilayer wafer level lens according to [55], wherein the number of wafers constituting the wafer level lens is 2 to 5.

[57] A method of manufacturing a laminated wafer level lens, comprising the method of manufacturing a multilayer wafer level lens according to [55] or [56], comprising the steps of: Step 1c: preparing one or more lenses a step of forming a mold for a wafer-level lens for a mold; and a step 2c of contacting the curable composition for a wafer-level lens according to any one of [1] to [32] with the mold for forming a wafer-level lens Step 3c: a step of curing the wafer-level lens with a hardenable composition by heating and/or light irradiation to obtain a wafer-level lens sheet; Step 4c: a step of laminating a plurality of wafer-level lens sheets including the wafer-level lens sheet to obtain a wafer-level lens sheet laminate; and step 5c: cutting the wafer-level lens sheet laminate.

[58] The method of manufacturing a multilayer wafer level lens according to [57], wherein the step of step 3c and step 4c further comprises the step of: step 6c: annealing the wafer level lens sheet.

[59] A wafer level lens sheet laminate obtained by laminating a plurality of wafer level lens sheets of the wafer level lens sheet according to [46].

[60] An optical device loaded with a laminated wafer level lens as described in [55] or [56].

Since the curable composition for a wafer-level lens of the present invention has the above-described configuration, it is excellent in quick-curing property and shape stability at the time of curing, and is cured to have high heat resistance and high transparency. A cured product (wafer level lens) with optical properties such as high refractive index and low Abbe number. In particular, the curable composition for a wafer level lens of the present invention has a small curing shrinkage ratio and is excellent in shape stability, and the use of the curable composition can contribute to designing a wafer level lens having high precision. Further, in the case where the alicyclic epoxy compound (A) is in a liquid state, the curable composition of the present invention does not require the addition of a diluted component (such a diluted component adversely affects the refractive index or Abbe number of the cured product). ), optical properties such as high refractive index and low Abbe number of the cured product can be maintained as they are, and rapid hardenability can be achieved, which contributes to improvement in productivity of the wafer-level lens. The use of such a wafer-level lens contributes to downsizing, weight reduction, and high performance of an optical device using the same.

In the present specification, the "wafer level lens" means a lens used for manufacturing a camera for use in a mobile phone or the like at a wafer level, and the scale thereof is, for example, about 1 to 10 mm in diameter, preferably about 3~5mm. Further, the thickness thereof is, for example, about 100 to 1,500 μm, preferably about 500 to 800 μm.

[Formation of the Invention]

<Curable composition for wafer level lens>

The curable composition for a wafer-level lens of the present invention (may be simply referred to as "the curable composition of the present invention") is an alicyclic epoxy compound (A) having no ester group, and a cation having an aromatic ring. The polymerizable compound (B) is a curable composition as an essential component. The curable composition of the present invention may contain, for example, a thermal cation hardener (C), a photocation hardener (D), an antioxidant, a mold release agent, various additives, and the like, which are described below, in addition to the above-mentioned essential components. . Further, the curable composition of the present invention may be a thermosetting composition which forms a cured product (resin cured product) by heat curing, for example, by selecting a type of the curing agent, or may be light ( Light-curing) A photocurable composition that hardens to form a cured product.

[Cycloaliphatic epoxy compound (A)]

The alicyclic epoxy compound (A) which does not have an ester group (ester bond) in the curable composition of the present invention (hereinafter, simply referred to as "alicyclic epoxy compound (A)" or "ingredient (A) ))) is a compound having no ester group (ester bond) in the molecule and having at least 2 epoxidized cyclic olefin groups in the molecule . The "epoxidized cyclic olefin group" of the alicyclic epoxy compound (A) means a cyclic olefin (a ring-shaped fat in which at least one carbon-carbon bond forming a ring is a carbon-carbon unsaturated bond) a group (monovalent group) formed by removing one hydrogen atom in a structure in which at least one of carbon-carbon unsaturated bonds of a hydrocarbon group is epoxidized, and hereinafter referred to as "epoxidized cyclic olefin" "" or "alicyclic epoxy". That is, the epoxidized cyclic olefin group includes an aliphatic hydrocarbon ring structure and an epoxy group, and the epoxy group is an epoxy group constituting the adjacent two carbon atoms and oxygen atoms of the aliphatic hydrocarbon ring.

The cyclic olefin group (form before epoxidation) in the above epoxidized cyclic olefin group may, for example, be a cyclopropenyl group (for example, 2-cyclopropen-1-yl group) or a cyclobutenyl group (for example). , 2-cyclobuten-1-yl, etc.), cyclopentenyl (for example, 2-cyclopenten-1-yl, 3-cyclopenten-1-yl, etc.), cyclohexenyl (for example, 2 -cyclohexen-1-yl, 3-cyclohexen-1-yl, etc., etc., cycloalkenyl; 2,4-cyclopentadien-1-yl, 2,4-cyclohexadien-1-yl a cyclodienyl group such as 2,5-cyclohexadien-1-yl; a polycyclic group such as a dicyclopentenyl, a bicyclohexenyl or a norbornene group; and the like.

Further, the aliphatic hydrocarbon ring forming the cyclic olefin group in the epoxidized cyclic olefin group may be bonded to one or more substituents. Examples of the substituent include a substituent having a carbon number of 0 to 20 (more preferably a carbon number of 0 to 10), and more specifically, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. a halogen atom; a hydroxyl group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group or an isobutoxy group (preferably a C _1-6 alkoxy group, more preferably C _1-4 alkoxy); alkenyloxy and the like alkenyloxy group (preferably C _2-6 alkenyloxy group, more preferably C _2-4 alkenyloxy group); phenoxy group, tolyloxy group, naphthalene An aryloxy group (preferably a C _6-14 aryloxy group) which may have a substituent such as a C _1-4 alkyl group, a C _2-4 alkenyl group, a halogen atom or a C _1-4 alkoxy group on the aromatic ring. An aralkyloxy group (preferably a C _7-18 aralkyloxy group); an ethoxycarbonyl group, a propyl decyloxy group, a (meth) acryloxy group, or a benzyloxy group; a decyloxy group such as a benzyloxy group (preferably a C _1-12 decyloxy group); a fluorenyl group; an alkylthio group such as a methylthio group or an ethylthio group (preferably a C _1-6 alkylthio group, more preferably C _1-4 alkylthio); allyl group and the like alkenyl group (preferably C _2-6 alkenyl group, more preferably C _2-4 alkylene group); a phenylthio group, tolyl group, naphthyl Sulfur group on the aromatic ring Having C _1-4 alkyl, C _2-4 alkenyl group, a halogen atom, C _1-4 alkoxy substituents of aryl group (preferably a C _6-14 aryl group); benzylthio, An aralkylthio group such as phenethylthio group (preferably C _7-18 aralkylthio group); a carboxyl group; an alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group or a butoxycarbonyl group (preferably C _1-6 alkoxy-carbonyl); aryloxycarbonyl group such as phenoxycarbonyl, toluyloxycarbonyl or naphthyloxycarbonyl (preferably C _6-14 aryloxy-carbonyl); aralkyloxy such as benzyloxycarbonyl carbonyl group (preferably C _7-18 aralkyloxy - carbonyl group); amino; methylamino, ethylamino, dimethylamino, diethylamino and the like mono- or di-alkylamino ( Preferably, it is a mono- or di-C _1-6 alkylamino group; a mercaptoamine group such as an acetamino group, a propylamino group or a benzhydrylamino group (preferably a C _1-11 mercapto group) a group containing an oxetanyl group such as an ethyloxetanyloxy group; a fluorenyl group such as an ethyl fluorenyl group, a propyl fluorenyl group or a benzamidine group; a pendant oxy group; these two or more are optionally required via C _1-6 alkyl group bonded to the base and the like.

Among them, the cyclic olefin group is preferably a cyclic olefin group having 5 to 12 carbon atoms, more preferably a cycloalkenyl group having 5 to 12 carbon atoms, still more preferably a cyclohexenyl group. That is, in the case of the above epoxidized cyclic olefin group, a cyclic olefin group having 5 to 12 carbon atoms is preferably epoxidized, and more preferably a cycloalkenyl group having 5 to 12 carbon atoms is epoxidized. Base, further better for the ring A epoxidized group of a hexenyl group (cyclohexene oxide group). In addition, the alicyclic epoxy compound (A) may have one type of epoxidized cyclic olefin group, or may have two or more types.

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

The alicyclic epoxy compound (A) is preferably 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. The divalent hydrocarbon group may, for example, be a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a plurality of bonded groups. The above-mentioned divalent aliphatic hydrocarbon group may, for example, be a straight chain such as a methylene group, a methylmethylene group, a dimethylmethylene group, an exoethyl group, a propyl group, a trimethylene group or a tetramethylene group. Or a branched chain alkyl group (for example, an alkyl group having 1 to 6 carbon atoms). Further, examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentenyl, 1,3-cyclopentyl, 1,2-extended cyclohexyl, 1,3-cyclohexylene, A divalent cycloalkyl group such as a 1,4-cyclohexylene group.

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

R-X-R (a1)

In the above formula (a1), R represents an epoxidized cyclic olefin group. The two Rs may be the same or different. X represents a single bond or a divalent hydrocarbon group. The epoxidized cyclic olefin group of R and the divalent hydrocarbon group of X may be the same as described above. For example, the compound represented by the formula (a1) in which both R are cyclohexene oxide groups is as shown in the following formula (a2). Compounds, etc.

[In the formula (a2), X is the same as described above].

In addition, the alicyclic epoxy compound (A) may be used singly or in combination of two or more kinds.

The content (mixing amount) of the alicyclic epoxy compound (A) in the curable composition of the present invention is not particularly limited, but is relative to the total amount (total amount) (100% by weight) of the curable composition. It is preferably 10 to 60% by weight, more preferably 15 to 55% by weight, 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, when the content of the alicyclic epoxy compound (A) exceeds 60% by weight, it is difficult to impart optical characteristics such as a high refractive index and a low Abbe number to a 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 10 to 60% by weight is more preferably 15 to 55% by weight, still more preferably 20 to 50% by weight. When the ratio is less than 10% by weight, the curability of the curable composition may be insufficient. On the other hand, when the ratio exceeds 60% by weight, it may become difficult to impart optical characteristics such as a high refractive index and a low Abbe number to the cured product.

[Cationally polymerizable compound (B) having an aromatic ring]

The cationically polymerizable compound (B) having an aromatic ring in the curable composition of the present invention (hereinafter, simply referred to as "cationic polymerizable compound (B)" or "component (B)") has at least 1 in the molecule. A compound having at least one aromatic ring and at least one cationic hardening functional group (cationically polymerizable functional group). By the cationically polymerizable compound (B), the cured product obtained by curing the curable composition of the present invention is particularly effective in imparting heat resistance, high transparency, high refractive index, low Abbe number, and the like. The tendency of optical properties.

The aromatic ring of the cationically polymerizable compound (B) is not particularly limited, and examples thereof include an aromatic monocyclic hydrocarbon ring such as a benzene ring, and an aromatic group such as a naphthalene ring, an anthracene ring, an anthracene ring or an anthracene ring. An aromatic hydrocarbon ring such as a condensed polycyclic hydrocarbon ring. Further, examples of the aromatic ring include a pyridine ring, a furan ring, a pyrrole ring, a benzofuran ring, an anthracene ring, a carbazole ring, a quinoline ring, a benzimidazole ring, and a quin An aromatic heterocyclic ring such as a porphyrin ring. In particular, the aromatic ring is preferably an aromatic hydrocarbon ring, more preferably a benzene ring or an anthracene ring, and further, from the viewpoint of easily imparting optical characteristics such as a high refractive index and a low Abbe number to the cured product. It is especially good to use the ring.

Further, one or more substituents may be bonded to the aromatic ring of the cationically polymerizable compound (B). The substituent may be, for example, the same as the substituent bonded to the aliphatic hydrocarbon ring capable of forming the above cyclic olefin group. In addition, the cationically polymerizable compound (B) may have one type of aromatic ring, or may have two or more types.

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

The cationically curable functional group of the cationically polymerizable compound (B) may be a functional group having a cationic curing property (cationic polymerizability) or a conventionally used functional group, and is not particularly limited, and examples thereof include an epoxy resin. Base, oxetanyl, tetrahydrofuranyl, A cyclic ether group such as an oxazoline group; a vinyl group-containing group such as a vinyl ether group or a styryl group; and a group containing at least these groups. In the above-mentioned cationically curable functional group, from the viewpoint of reactivity with the alicyclic epoxy compound (A), an alicyclic epoxy group (epoxidized cyclic olefin group), a glycidyl group, Oxecyclobutyl is preferred. In addition, the cationically polymerizable compound (B) may have one type of cationically curable functional group, or may have two or more types.

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

In the cationically polymerizable compound (B), examples of the epoxy compound having an aromatic ring include a bisphenol A type epoxy compound (bisphenol A or a diglycidyl ether of an alkylene oxide addition product thereof). ), bisphenol F type epoxy compound (bis-glycidyl ether of bisphenol F or its alkylene oxide addition), bisphenol type epoxy compound, phenol resin type epoxy compound, cresol novolac type epoxy Compound, cresol type epoxy compound, bisphenol A cresol novolac type epoxy compound, polyphenol type epoxy compound, brominated bisphenol A type epoxy compound, brominated bisphenol F type epoxy compound, hydrogen Glycidyl diglycidyl ether, resorcinol diglycidyl ether, diglycidyl terephthalate, diglycidyl phthalate, polybutadiene with terminal carboxylic acid and bisphenol A ring Oxygen resin addition reactant, naphthalene type epoxy compound (Epoxy compound having a naphthalene ring), an epoxy compound having an anthracene ring, and the like. In addition, as the epoxy compound having an aromatic ring, for example, an alicyclic epoxy compound having an aromatic skeleton disclosed in JP-A-2009-179568 can be used.

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

In the 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. The alkyl group having 1 to 6 carbon atoms may, for example, be a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a secondary butyl group, a tertiary butyl group or a pentyl group. Heji and so on. Among them, R ¹ to R ⁵ and R ⁷ to R ¹¹ are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom.

In the formula (b1), the ring Z ¹ and the ring Z ² are the same or different and each represents an aromatic carbocyclic ring (aromatic hydrocarbon ring). Examples of the aromatic carbocyclic ring in the ring Z ¹ and the ring Z ² include an aromatic carbocyclic ring of about 1 to 4 rings such as a benzene ring, a naphthalene ring or an anthracene ring. Among them, as the aromatic carbocyclic ring, a benzene ring, a naphthalene ring or the like is preferred.

In formula (b1), of formula (b1) shown in the fluorene ring, Z ^1, ring Z ^2, may have a substituent group. The above substituent may, for example, be an alkyl group such as a methyl group, an ethyl group, a propyl group or an isopropyl group (for example, a C _1-6 alkyl group, preferably a methyl group); a cyclopentyl group, a cyclohexyl group or the like. a cycloalkyl group (for example, a C _5-8 cycloalkyl group or the like); an aryl group such as a phenyl group or a naphthyl group (for example, a C _6-15 aryl group or the like); an aralkyl group such as a benzyl group (for example, C _7-16) An aralkyl group, etc.; an alkyl group such as an ethyl group, a propyl group or a benzhydryl group (for example, a C _1-10 fluorenyl group); a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, or the like; Alkoxy group (for example, C _1-6 alkoxy group, etc.); alkoxycarbonyl group such as methoxycarbonyl group or ethoxycarbonyl group (for example, C _1-4 alkoxy-carbonyl group, etc.); cyano group; carboxyl group; A nitro group; an amine group; a substituted amine group (for example, a mono- or di-C _1-4 alkylamino group, etc.); a halogen atom such as a fluorine atom or a chlorine atom; and the like.

In the formula (b1), R ⁶ and R ¹² are the same or different and each represents an alkylene group having 1 to 10 carbon atoms. Examples of the alkylene group in R ⁶ and R ¹² include a methylene group, an exoethyl group, a propyl group, a trimethylene group (i.e., a 1,3-propenyl group), and a tetramethylene group (i.e., A linear or branched chain alkyl group having a carbon number of 1 to 10, such as 1,4-butylene) or hexamethylene (i.e., 1,6-extended hexyl). Among them, in the case of the above alkylene group, a C 2 to 6 alkyl group such as an ethyl group, a propyl group or a trimethylene group is preferred, and a C 2 or 3 alkyl group is more preferred.

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

In addition, as the compound represented by the formula (b1), commercially available products such as the trade names "PG-100" and "EG-200" (above, Osaka Gas Chemical Co., Ltd.) can be used.

Among the cationically polymerizable compounds (B), examples of the oxetane compound having an aromatic ring include, for example, 1,4-bis{[(3-ethyl) 3-oxetanyl)methoxy]methyl}benzene, 3-ethyl-3-[(phenoxy)methyl]oxetane, 4,4'-double [3-ethyl A base-(3-oxetanyl)methoxymethyl]biphenyl, a phenol resin type oxetane resin, or the like.

A commercially available product can also be used for the cationically polymerizable compound (B). The commercial product of the bisphenol A type epoxy compound among the cationically polymerizable compound (B) includes, for example, the trade names "jER827", "jER828", "jER828EL", "jER828XA", and "jER834" ( Above, Mitsubishi Chemical Co., Ltd.; trade name "Epiclon 840", "Epiclon 840-S", "Epiclon 850", "Epiclon 850-S", "Epiclon 850-LC" (above, DIC) )Wait. In addition, as a commercial item of the epoxy compound which has a naphthalene ring in the molecule among the cationically polymerizable compound (B), the brand name "Epiclon HP4032", "HP4032D", "HP4700", "HP4710" ""HP4770", "HP5000" (above, DIC (share) system). In addition, as a commercial item of the epoxy compound which has an anthracene ring in a molecule among the cationically polymerizable compound (B), the brand name "PG-100", "EG-200", and "EG" are mentioned. -250" (above, Osaka Gas Chemical Co., Ltd.); trade name "On-Court EX-1010", "On-Court EX-1011", "On-Court EX-1012", "On-Court EX-" 1020", "On-Court EX-1030", "On-Court EX-1040", "On-Court EX-1050", "On-Court EX-1051" (above, Changchun Industry Co., Ltd.) . In addition, as a commercial item of the oxetane compound which has an aromatic ring in a molecule among the cationically polymerizable compound (B), the brand name "OXT-121" and "OXT-211" are mentioned. (The above, East Asia Synthetic Co., Ltd.); trade name "ETERNACOLL OXBP" (Ube Industries, Ltd.).

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

The content (mixing amount) of the cationically polymerizable compound (B) in the curable composition of the present invention is not particularly limited, but is 40 to 90% by weight based on the total amount (100% by weight) of the curable composition. More preferably, it is more preferably 40 to 80% by weight, still more preferably 45 to 75% by weight. When the content of the cationically polymerizable compound (B) is less than 40% by weight, it may be difficult to impart optical characteristics such as a high refractive index and a low Abbe number to the cured product. On the other hand, when the content of the cationically polymerizable compound (B) exceeds 90% by weight, it may be difficult to obtain an effect of improving the quick-curing property and the shape stability at the time of curing.

The ratio of the total amount of the component (A) and the 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, Less than 100% by weight) is more preferably 90% by weight or more (for example, 90 to 98% by weight). When the ratio is less than 80% by weight, the quick-setting property and shape stability of the curable composition at the time of curing, the heat resistance of the cured product, and the optical properties (high transparency, high refractive index, low Abbe number) are controlled in a balanced manner. ) and other characteristics sometimes become difficult.

[Thermal cationic hardener (C)]

The curable composition of the present invention may contain a thermal cation hardener (C) (hereinafter sometimes referred to as "component (C)"). The thermal cationic curing agent (C) is a cationically curable compound (a compound having a cationic hardening functional group) contained in a curable composition by heating; for example, an alicyclic ring A compound which starts or proceeds by a polymerization reaction (hardening reaction) of the oxygen compound (A), the cationically polymerizable compound (B), and a releasing agent having one or more cationically curable functional groups in the molecule. As the thermal cationic hardener (C), a known or customary compound having the above-described effects can be used, and it is not particularly limited, and for example, a cationic species is generated by heating, whereby the curable compound is polymerized (hardened). The beginning of the thermal cationic polymerization initiator and the like.

The thermal cationic curing agent (C) may, for example, be a thermal cationic polymerization initiator such as an aryldiazonium salt, an aryliodonium salt, an arylsulfonium salt or an arene-ion complex. Further, examples of the thermal cation hardener (C) include compounds of a metal such as aluminum or titanium, a chelating compound of acetylacetic acid or a diketone, and a stanol such as triphenylsulfanol; or aluminum or A thermal cationic polymerization initiator such as a metal such as titanium, a chelating compound of acetylacetic acid or a diketone, and a phenolic compound such as bisphenol S. For the thermal cation hardener (C), for example, the trade names "PP-33", "CP-66", "CP-77" (above, ADEKA) can be used; the trade name "FC- 509" (3M system); trade name "UVE1014" (made by GE); trade name "San-Aid SI-60L", "San-Aid SI-80L", "San-Aid SI-100L", "San-Aid" SI-110L", "San-Aid SI-150L" (above, Sanshin Chemical Industry Co., Ltd.); and commercial products such as "CG-24-61" (BASF).

In the thermal cationic curing agent (C), it is preferred to use a curing start temperature of the curable composition of the present invention described later at 60 to 150 ° C (more preferably 80 to 120 ° C).

Furthermore, in the curable composition of the present invention, it is hot One type of the ionic hardening agent (C) may be used alone or two or more types may be used in combination.

The content (mixing amount) of the thermal cation hardening agent (C) in the curable composition of the present invention is not particularly limited, but is 100 parts by weight based on 100 parts by weight of the total amount of the cationically curable compound contained in the curable composition. It is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, still more preferably 0.1 to 3 parts by weight. When the content is less than 0.001 part by weight, particularly in the case of forming a thick cured product, hardening failure may occur easily. On the other hand, when the content exceeds 10 parts by weight, the physical properties such as heat resistance of one cured product may be lowered, and the cost may be disadvantageous in some cases.

[Photocation hardener (D)]

Further, (for example, instead of the thermal cation curing agent (C)), the curable composition of the present invention may contain a photocationic curing agent (D) (hereinafter sometimes referred to as "component (D)"). The photo-cationic curing agent (D) is a cationically curable compound (a compound having a cationic hardening functional group) which can be contained in a curable composition by light (light irradiation); for example, an alicyclic epoxy compound (A) A compound in which a polymerization reaction (hardening reaction) of a cationically polymerizable compound (B) and a release agent having one or more cationically curable functional groups in the molecule starts or proceeds. As the photo-cationic curing agent (D), a known or customary compound having the above-described effects can be used, and is not particularly limited. For example, a cationic species is generated by light irradiation, whereby a curing compound is polymerized (hardened). The starting photocationic polymerization initiator and the like.

For the cationic catalyst which generates a cationic species by light irradiation (especially, ultraviolet irradiation), for example, hexafluoroantimonate, five Fluorohydroxy decanoate, hexafluorophosphate, hexafluoroarsenate, and the like. For the above cationic catalyst, for example, the trade name "UVACURE 1590" (made by Daicel Cytec Co., Ltd.); the trade names "CD-1010", "CD-1011", and "CD-1012" (above, American company Sartomer); trade name "Irgacure 264" (made by BASF); trade name "CIT-1682" (made by Japan Soda Co., Ltd.); trade name "CPI-101A" (San-Apro (share) system) Sale.

In the curable composition of the present invention, one type of the photocationic curing agent (D) may be used alone or two or more types may be used in combination.

The content (doping amount) of the photocationic curing agent (D) in the curable composition of the present invention is not particularly limited, but is 100 parts by weight based on 100 parts by weight of the total amount of the cationically curable compound contained in the curable composition. It is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, still more preferably 0.1 to 3 parts by weight. When the content is less than 0.001 part by weight, in particular, when a thick cured product or the like is formed, hardening failure may easily occur. On the other hand, when the content exceeds 10 parts by weight, the physical properties such as heat resistance of one cured product are lowered, and the cost may be disadvantageous in some cases.

[Antioxidants]

The curable composition of the present invention may further contain an antioxidant. For the above-mentioned antioxidant, a known or customary compound which can be used as an antioxidant can be used, and it is not particularly limited, and examples thereof include a phenolic antioxidant (phenolic compound) and a phosphorus antioxidant (phosphorus compound). A sulfur-based antioxidant (a sulfur-based compound) or the like.

Examples of the above phenolic antioxidant include 2,6-di-tertiary butyl-p-cresol, butylated hydroxyanisole, and 2,6-di-tertiary butyl-p-ethyl. Monophenols such as phenol, β-(3,5-di-tri-tert-butyl-4-hydroxyphenyl)propionic acid stearyl ester; 2,2'-methylenebis(4-methyl-6-three Butyl phenol), 2,2'-methylene bis(4-ethyl-6-tributyl phenol), 4,4'-thiobis(3-methyl-6-tertiary butyl phenol ), 4,4'-butylidene bis(3-methyl-6-tertiary butyl phenol), 3,9-bis[1,1-dimethyl-2-{β-(3-tertiary butyl) Bisphenols such as 4-hydroxy-5-methylphenyl)propoxycarbonyl}ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane; 1,1,3 - ginseng (2-methyl-4-hydroxy-5-tributylphenyl)butane, 1,3,5-trimethyl-2,4,6-paran (3,5-di-tris Butyl-4-hydroxybenzyl)benzene, fluorene-[methylene-3-(3',5'-di-tertiarybutyl-4'-hydroxyphenyl)propionate]methane, double [ 3,3'-bis(4'-hydroxy-3'-tertiary butylphenyl)butyric acid] ethylene glycol ester, 1,3,5-paran (3',5'-di-tertiary butyl -4'-hydroxybenzyl)-s-three -2,4,6-(1H,3H,5H) triketone, a polymer type phenol such as tocopherol, and the like.

Examples of the phosphorus-based antioxidant include triphenyl phosphite, isodecyl phosphite, diisononyl phosphite, decyl phenyl phosphite, and diisonon. Neopentyl pentaerythritol phosphite, bisphosphite ginseng (2,4-di-tert-butylphenyl ester), cyclopentaerythritol bis (octadecyl phosphite), cyclopentaerythritol bis (Asian) 2,4-di-tert-butylphenyl phosphate), cyclopentaerythritol bis (2,4-di-tert-butyl-4-methylphenyl phosphite), hydrogen bisphosphonate [2- Phosphites such as tertiary butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl] ester; 9,10-dihydro-9-oxa-10-phosphine Phenanthrene-10-oxide, 10-(3,5-di-tri-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Oxaphosphorus oxides such as oxides.

As the above-mentioned sulfur-based antioxidant, for example, February Citrine-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, and the like.

Among them, in the case of an antioxidant, a phenolic antioxidant is preferred. In the curable composition of the present invention, one type of the antioxidant may be used alone or two or more types may be used in combination.

The content (mixing amount) of the antioxidant in the curable composition of the present invention is not particularly limited, but is 0.001 to 15 parts by weight based on 100 parts by weight of the total amount of the cationically curable compound contained in the curable composition. More preferably, it is preferably 0.01 to 10 parts by weight, still more preferably 0.1 to 5 parts by weight. When the content is less than 0.001 part by weight, the suppression of deterioration such as oxidation may be insufficient depending on the application. On the other hand, when the content exceeds 15 parts by weight, physical properties such as heat resistance of one cured product may be lowered, and further, it may become disadvantageous in terms of cost.

[release agent]

The curable composition of the present invention may further contain a release agent. As the above-mentioned release agent, a known or customary compound which can be used as a release agent can be used, and is not particularly limited, and examples thereof include a (poly)oxyalkylalkylphosphoric acid compound and a fluorine compound (fluorine-based compound). A release agent), a polyoxymethylene compound, a compound having a long-chain alkyl group, a polyalkylene wax, a guanamine wax, a polytetrafluoroethylene powder, or the like. Among them, a release agent having one or more cationically curable functional groups in the molecule is preferred from the viewpoint of not impairing transparency, and more preferably one or more cationically curable functional groups in the molecule. Compound (fluorine-based release agent).

Examples of the cation-curable functional group of the fluorine compound having one or more cationically curable functional groups in the molecule include an epoxy group, an oxetanyl group, and a tetrahydrofuranyl group. A cyclic ether group such as an oxazoline group; a vinyl group-containing group such as a vinyl ether group or a styryl group; and a group containing at least these groups. Among them, the cation-curable functional group is preferably a cyclic ether group, more preferably an epoxy group. In addition, the number of the cationically curable functional groups of the fluorine compound having one or more cationically curable functional groups in the molecule is not particularly limited as long as it is one or more (for example, one to four). Further, in the case of having a plurality of cationically curable functional groups, it may have only one type of cationically curable functional group, and may have two or more kinds of cationically curable functional groups.

The fluorine compound having one or more cationically curable functional groups in the molecule may, for example, be a fluorine-substituted hydrocarbon (epoxy-substituted hydrocarbon containing an epoxy group) having an epoxy group, and more specifically, For example, a compound represented by the following formula (i) (a monofunctional epoxy compound having a fluoroalkyl group) or the like can be given.

r in the above formula (i) represents an integer of 1 to 15. Also, s represents an integer from 1 to 5. Y represents a hydrogen atom, a fluorine atom, or a fluoroalkyl group. The fluoroalkyl group may, for example, be an alkyl group in which one or both of hydrogen atoms are substituted with a fluorine atom and has a carbon number of 1 to 20 (preferably 1 to 10) [for example, trifluoromethyl group, perfluoro group] Isopropyl, etc.]. Further, -(CH ₂ ) _r - in the formula (i) may be one in which a part of the hydrogen atom is substituted with a hydroxyl group, or may be an ether bond in the middle. More specifically, the compound represented by the formula (i) includes 3-perfluorohexyl-1,2-epoxypropane and the like.

For the above-mentioned release agent, for example, the trade name " E-1430, E-1630, E-1830, E-2030, E-3430, E-3630, E-3830, E-4030, E- Commercial products such as 5244", "E-5444", "E-5644", and "E-5844" (fluorine-based release agent, above, manufactured by Daikin Industries Co., Ltd.). In addition, one type of the release agent may be used alone or two or more types may be used in combination in the curable composition of the present invention.

The content (mixing amount) of the releasing agent in the curable composition of the present invention is not particularly limited, but is 100 parts by weight based on the total amount of the alicyclic epoxy compound (A) and the cationically polymerizable compound (B). It is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight. When the content of the releasing agent is less than 0.01 parts by weight, the molding may not be released from the mold at the time of molding. On the other hand, when the content of the release agent exceeds 10 parts by weight, the transparency of the curable composition may be impaired.

[additive]

The curable composition of the present invention may contain other components such as additives in addition to the above components. The additive is not particularly limited as long as it is conventionally used, and examples thereof include metal oxide particles, rubber particles, polyfluorene-based or fluorine-based antifoaming agents, decane coupling agents, and fillers. , plasticizer, leveling agent, antistatic agent, flame retardant, colorant, ultraviolet absorber, ion adsorbent, pigment, etc. The content (mixing amount) of the various additives is not particularly limited, but is preferably 5% by weight or less (for example, 0 to 5% by weight) based on the curable composition (100% by weight). Further, the curable composition of the present invention may contain a solvent, but if it is too much, bubbles may be formed in the cured product, so that 10 parts by weight with respect to the curable composition (100% by weight) % or less (for example, 0 to 10% by weight) is preferable, and 1% by weight or less is more preferable.

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

The curable composition of the present invention is not particularly limited, and for example, a predetermined amount of the alicyclic epoxy compound (A), the cationically polymerizable compound (B), and the thermal cationic curing agent (C) can be blended. Further, an antioxidant, a mold release agent, various additives, and the like are further blended as needed, and bubbles are removed under vacuum as needed, and stirred and mixed to prepare. The temperature at the time of mixing and mixing is preferably, for example, about 10 to 60 °C. Further, the stirring and mixing may be carried out using a conventionally known device such as a self-rotating revolution mixer, a single-shaft or multi-axis extruder, a planetary mixer, a kneader, a dissolver, or the like.

The curing start temperature of the curable composition of the present invention (in particular, the case where the thermal cation hardener (C) is contained) is not particularly limited, but is preferably 60 to 150 ° C, more preferably 80 to 120 ° C. If the hardening start temperature of the curable composition of the present invention is less than 60 ° C, there is preservation stability Poor, sometimes not suitable for use at room temperature (25 ° C). In addition, the "hardening start temperature of the curable composition" means the climb temperature at the time of measuring the heat of reaction using a DSC (differential scanning calorimeter) under the following conditions in the curable composition of the present invention (starting from the baseline) Climbing temperature).

(Measurement conditions of DSC)

‧ Determination of gas: nitrogen (flow: 50mL / min)

‧Measurement temperature: 30~300°C

‧ Heating conditions: 20 ° C / min

Further, the curing initiation temperature of the curable composition of the present invention can be, for example, a composition of a curable composition (for example, a kind of a thermal cationic hardener (C); in particular, an alicyclic epoxy compound (A) Controlled by a combination of a cationically polymerizable compound (B) and a thermal cation hardener (C).

By curing the curable composition of the present invention, a cured product (sometimes referred to as "the cured product of the present invention") can be obtained. The internal light transmittance of the cured product of the present invention (internal light transmittance of light having a wavelength of 400 nm) [converted to a thickness of 0.5 mm] is not particularly limited, but is 70% or more (for example, 70 to 100%). Preferably, it is more preferably 75% or more, further preferably more than 80%, and particularly preferably more than 85%.

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

The Abbe number of the cured product of the present invention is not particularly limited, but is preferably 35 or less, more preferably 30 or less, still more preferably 27 or less.

The glass transition temperature (glass transition point) (Tg) of the cured product of the present invention is not particularly limited, but is 100 ° C or higher (for example, 100~). 200 ° C) is preferred, more preferably 140 ° C or higher. When the glass transition temperature is less than 100 ° C, the heat resistance of the cured product may become insufficient depending on the use. The glass transition temperature of the cured product can be measured by, for example, various thermal analysis [IDSC (differential scanning calorimeter), TMA (thermomechanical analysis device), etc.) or dynamic viscoelasticity measurement, and more specifically, can be carried out according to the implementation. The measurement method described in the example was measured.

The coefficient of linear expansion (α1) below the glass transition temperature of the cured product of the present invention is not particularly limited, but is preferably 40 to 100 ppm/K, more preferably 40 to 90 ppm/K. Further, the linear expansion coefficient (α2) of the cured product of the present invention at a glass transition temperature or higher is not particularly limited, but is preferably 90 to 150 ppm/K, more preferably 90 to 130 ppm/K. Further, the linear expansion coefficients α1 and α2 of the cured product can be measured by, for example, TMA or the like, and more specifically, can be measured according to the measurement method described in the examples.

<Method of Manufacturing Wafer Level Lens>

A wafer level lens (sometimes referred to as "wafer level lens of the present invention") can be obtained by curing and molding the curable composition of the present invention. That is, the wafer level lens of the present invention is a wafer level lens formed of a cured product of the curable composition of the present invention. Therefore, the wafer-level lens of the present invention preferably has the same characteristics (internal transmittance, refractive index, Abbe number, glass transition temperature, linear expansion coefficient (α1, α2)) as the above-mentioned cured product. Specifically, the wafer level lens of the present invention can be subjected to a casting molding method or an injection molding method by a method of applying the curable composition of the present invention (sometimes referred to as "the manufacture of the wafer level lens of the present invention" Method").

Furthermore, the mold for wafer level lens formation (wafer level) The material of the lens molding die is not particularly limited, and may be, for example, any of metal, glass, and plastic.

[casting method]

The above casting molding method includes, for example, a method including the following steps 1a to 3a.

Step 1a: a step of preparing a wafer-level lens molding die having one or more lens molds; Step 2a: a step of bringing the curable composition of the present invention into contact with the wafer-level lens molding die after the step 1a; 3a: a step of hardening the curable composition of the present invention by heating and/or light irradiation after the step 2a.

The hardening of the curable composition of the present invention can be carried out by heating and/or light irradiation (either heating or light irradiation or both) (step 3a). In the case of the heat treatment, the temperature may be appropriately adjusted depending on the type of the component to be reacted or the type of the catalyst, and is not particularly limited, and is preferably 100 to 200 ° C, more preferably about 120 to 160. °C. In the case of light irradiation, for the light source, for example, a mercury lamp, a xenon arc lamp, a carbon arc lamp, a metal halide lamp, sunlight, an electron beam source, a laser light source, or the like can be used. Further, after the light irradiation, heat treatment may be performed at, for example, a temperature of about 50 to 180 ° C to carry out a further hardening reaction.

The above casting molding method may further include the following step 4a after the step 3a: the step 4a: the step of annealing the hardened composition of the present invention to be cured.

The annealing treatment is not particularly limited, but may be For example, the temperature of 100 to 200 ° C is heated for about 30 minutes to 1 hour. Further, the annealing treatment may be performed after removing the wafer-level lens molding mold, or may be performed without removing it.

In the case of the above-described casting molding method, in particular, the simultaneous molding method described later, generally, the sheet-like cured product formed by joining one to a plurality of wafer-level lenses can be obtained by the above-described step 3a or step 4a ( Wafer-level lens sheet). In the case where the wafer level lens sheet has a plurality of wafer level lenses, the wafer level lenses may be regularly arranged neatly (integrated) or may be arranged irregularly. The wafer level lens of the present invention can be obtained by cutting the wafer level lens sheet to remove excess portions.

That is, in the above casting molding method, particularly in the case of the simultaneous molding method described later, the casting molding method may further include the following step 5a after the step 3a or the step 4a: the step 5a: the hardening The step of cutting the curable composition of the invention (usually, a wafer-level lens sheet).

The hardening of the curable composition of the present invention can be carried out by well-known or conventional processing means.

More specifically, the above-described casting molding method includes a simultaneous molding method including the following steps 1-1 to 1-3, and includes a sheet molding method of the following steps 2-1 and 2-2.

(simultaneous molding method)

Step 1-1: a step of flowing the curable composition of the present invention into a wafer-level lens forming mold having a shape in which a plurality of lens molds are arranged in a certain direction, and heating and/or light-irradiating to harden; Step 1 2: After step 1-1, the wafer level lens molding die After removing, annealing is performed to obtain a cured product (wafer-level lens sheet) having a shape in which a plurality of wafer-level lenses are combined; Step 1-3: After step 1-2, the obtained cured product is obtained The step of cutting off the wafer level lens is obtained.

(piece molding method)

Step 2-1: a step of flowing the curable composition of the present invention into a wafer-level lens forming mold having one lens mold, and heating and/or light-irradiating to harden it; Step 2-2: Step 2 After that, the wafer-level lens forming mold is removed and annealed to obtain a wafer-level lens.

[Injection molding method]

The above injection molding method includes, for example, a method including the following steps 1b to 3b.

Step 1b: a step of preparing a wafer-level lens molding die having one or more lens molds; Step 2b: a step of ejecting the curable composition of the present invention into the wafer-level lens molding die after the step 1b; Step 3b: After step 2b, the step of hardening the curable composition of the present invention by heating and/or light irradiation.

The curing of the curable composition of the present invention in the above injection molding method can be carried out by heating and/or light irradiation, and more specifically, can be carried out in the same manner as the hardening in the above-described casting molding method.

The above injection molding method may further comprise the following step 4b after the step 3b: step 4b: annealing the hardened composition of the present invention to be cured A step of.

The annealing treatment is not particularly limited, and it can be carried out, for example, by heating at a temperature of 100 to 200 ° C for about 30 minutes to 1 hour. Further, the annealing treatment may be carried out by removing the wafer-level lens molding mold, or may be carried out without removing it.

The injection molding method may further include a step of removing burrs or the like after the step 3b or the step 4b.

In the simultaneous molding method in the above casting molding method, the curable composition of the present invention has low viscosity and excellent fluidity, and is preferable from the viewpoint of excellent filling property for a wafer-level lens molding die. The viscosity of the curable composition of the present invention used in the simultaneous molding method at 25 ° C is not particularly limited, but is preferably 5,000 mPa·s or less, more preferably 2,500 mPa·s or less. When the viscosity of the curable composition of the present invention is adjusted to the above range, the fluidity is improved, and the bubbles are less likely to remain, and the filling of the wafer-level lens molding die can be performed while suppressing the increase of the injection pressure. In other words, the coating property and the filling property can be improved, and workability can be improved in the entire molding operation of the curable composition of the present invention.

The cured product of the curable composition of the present invention has excellent heat resistance and excellent shape retention even in a high temperature environment of about 100 to 200 °C. Therefore, even if the annealing process is performed after removing the wafer-level lens forming mold, the wafer-level lens having excellent lens center position accuracy can be efficiently manufactured. The error of the center position of the lens in terms of lens center positional accuracy is preferably, for example, about ± 2 μm or less, more preferably about ± 1 μm or less. The method for manufacturing the wafer level lens of the present invention is obtained In the wafer level lens, a laminated lens (stacked wafer level lens) having an extremely high number of pixels and excellent optical characteristics can be formed by laminating a plurality of layers.

Further, since the cured product of the curable composition of the present invention has excellent shape retention even in a high-temperature environment as described above, even if an annealing treatment is performed, no error occurs in the lens pitch, and the step of the simultaneous molding method is performed. In 1-3, by stacking a plurality of cured products, the position of the cutting line is determined based on the uppermost cured product, and the cutting line is cut, so that the plurality of wafer-level lenses can be separated without being damaged, and the cost can be reduced. And make the work more efficient.

The wafer level lens of the present invention can also be used as a constituent member of a laminate of a plurality of wafer level lenses (sometimes referred to as "layered wafer level lens"). That is, the laminated wafer level lens of the present invention is a laminated wafer level lens having at least the wafer level lens of the present invention in terms of the wafer level lens constituting the laminated wafer level lens. Furthermore, the wafer level lenses constituting the laminated wafer level lens of the present invention may all be wafer level lenses of the present invention, and may be wafer level lenses and other wafer level lenses of the present invention. The number of wafer-level lenses constituting the laminated wafer-level lens of the present invention is not particularly limited, but may be, for example, 2 to 5 sheets (particularly 2 to 3 sheets).

The multilayer wafer level lens of the present invention can be produced by a known method or a conventional method, and is not particularly limited. For example, it can be manufactured by laminating a plurality of wafer-level lenses including the wafer level lens of the present invention. A wafer-level lens wafer layer comprising a wafer-level lens sheet obtained by the simultaneous molding method described above can be obtained to obtain a wafer-level lens wafer. After the layer body (layered body of the wafer level lens sheet), the wafer level lens sheet is cut and manufactured. Furthermore, in the multilayer wafer level lens of the present invention (or the wafer level lens sheet laminate), each wafer level lens (or between wafer level lens sheets) can be bonded by known or conventional means. , or not.

More specifically, the multilayer wafer level lens of the present invention can be produced by, for example, a method comprising at least the following steps 1c to 5c.

Step 1c: a step of preparing a wafer-level lens molding die having one or more lens molds; Step 2c: a step of bringing the curable composition of the present invention into contact with the wafer-level lens molding die after the step 1c; 3c: after step 2c, the step of curing the curable composition of the present invention by heating and/or light irradiation to obtain a wafer-level lens sheet; and after step 4c: step 3c, the plurality of wafer-level lens sheets are included Step of obtaining a wafer-level lens sheet laminate by laminating wafer-level lens sheets; Step 5c: Step of cutting the wafer-level lens sheet laminate after step 4c.

The method for manufacturing the stacked wafer level lens may further include the following steps between step 3c and step 4c: step 6c: a step of annealing the wafer level lens sheet.

The wafer level lens or the laminated wafer level lens of the present invention has excellent heat resistance and optical characteristics, and exhibits excellent shape retention even when exposed to a high temperature environment, and can maintain excellent optical characteristics. Therefore, it can be suitably used as, for example, a camera in various optical devices (car camera, digital camera, PC camera, mobile phone camera, supervisor) A photographic lens, an eyeglass lens, a beam collecting lens, a light diffusing lens, or the like, such as a camera. The above optical device loaded with the wafer level lens or the laminated wafer level lens of the present invention has high quality.

Furthermore, the wafer level lens or the laminated wafer level lens of the present invention can be soldered by reflow soldering in the case of mounting on a circuit board. Therefore, the camera module loaded with the wafer level lens or the laminated wafer level lens of the present invention can be directly mounted on the PCB (Printed Circuit Board) such as a mobile phone by the same reflow process together with the surface mounting of other electronic parts. Very efficient mounting makes it possible to manufacture extremely efficient optical devices.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples.

Examples 1 to 3 and Comparative Examples 1 to 3

Each of the components described in Table 1 was stirred and mixed at room temperature (25 ° C) using a self-rotating revolution mixer to obtain a curable composition (curable composition for a wafer-level lens). In addition, the unit of the blending amount shown in Table 1 is a weight part.

The abbreviations in Table 1 are explained.

[sclerosing compound]

PG-100: lanthanide epoxy compound (made by Osaka Gas Chemical Co., Ltd., trade name "PG-100")

EG-200: lanthanide epoxy compound (made by Osaka Gas Chemical Co., Ltd., trade name "EG-200")

827: bisphenol A type epoxy compound (Mitsubishi Chemical Co., Ltd., trade name "jER827")

C1: 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylic acid

C2: 3,4,3',4'-dicyclooxybicyclohexane

EA-F5503: an oxime-based acrylic compound (manufactured by Osaka Gas Chemical Co., Ltd., trade 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 cerium salt (Sanshin Chemical Industry Co., Ltd., trade name "San-Aid SI-100L")

[Thermal radical polymerization initiator]

Perhexa C: 1,1-di(tertiary butylperoxy)cyclohexane (manufactured by Nippon Oil Co., Ltd., trade name "Perhexa C", 1 minute half-life temperature: 153.8 °C)

[Antioxidants]

IRG1010: neopentyl alcohol oxime [3-(3,5-di-tri-butyl-4-hydroxyphenol) propionate] (manufactured by BASF Corporation, trade name "IRGANOX1010")

[release agent]

E-1630: 3-perfluorohexyl-1,2-epoxypropane (Dajin Industry Co., Ltd.) System, trade name "E-1630")

[Modification of hardened material]

The cured product was prepared in the following order.

The curable composition obtained in the examples and the comparative examples was subjected to coating (casting) at 25 ° C using an IMPRINT molding machine ("NANOIMPRINTER NM-0501" manufactured by Myeongchang Kogyo Co., Ltd.), and then the position of the press shaft was adjusted so that the position of the press shaft was adjusted. The thickness was 0.5 mm, and the temperature was raised to 180 ° C at a temperature increase rate of 20 ° C /min. Thereafter, the temperature was maintained at 180 ° C for 5 minutes, and after cooling to 80 ° C, the mold was released. The obtained cured product (referred to as "primary hardened material") was heated in an oven previously heated to 180 ° C for 30 minutes to obtain a cured product (referred to as "secondary cured product").

Further, in the production of the sample for mold release and lens positional deviation evaluation, a mold having seven aspherical lens shapes at the center of the mold was used, and a mold having a non-lens shape was used for the other samples for evaluation.

The following various measurements were performed on the curable composition obtained in the examples and the comparative examples and the cured product thereof.

[viscosity]

For the curable composition obtained in the examples and the comparative examples, a rheometer ("PHYSICA UDS200" manufactured by Paar Physica Co., Ltd.) was used, and the viscosity (Pa s) at a temperature of 25 ° C and a rotation speed of 20 / sec was measured.

[hardening rate]

With respect to the curable composition obtained in the examples and the comparative examples, a calorimeter calorimeter ("Q2000" manufactured by TA Instruments) was used, and the heat of hardening under the following temperature conditions was measured under nitrogen atmosphere to be used as a hardening property. The hardening of the sexual composition produces heat. Then, for the above The primary hardened material is obtained at the center portion and the peripheral portion of the primary cured product (the respective portions are obtained by cutting out the tool at the same place), and the heat generated by the hardening under the same temperature condition is measured, and the average value is used as the hardening of the primary hardened material. Produce heat. Then, the hardening rate was calculated by the following formula.

Temperature condition: After holding at 50 ° C for 3 minutes, the temperature was raised to 250 ° C at a temperature increase rate of 20 ° C / min, and maintained at 250 ° C for 3 minutes.

Hardening rate (%) = {1 - (hardening heat generation of primary hardened material) / (hardening heat generation of hardening composition)} × 100

[hardening start temperature]

For the curable composition obtained in the examples and the comparative examples, a differential scanning calorimeter ("Q2000" manufactured by TA Instruments Co., Ltd.) was used, and the hardening under heating was observed under the conditions of the above-mentioned measurement of the curing start temperature under nitrogen atmosphere. Heat production (reaction heat). In the obtained graph of hardening heat generation, the creeping temperature of the hardening heat generation (the temperature at which the climb from the baseline was started) was measured as the hardening start temperature.

[Internal transmittance]

The internal light transmittance of the secondary cured product (thickness: 0.5 mm) obtained above was calculated by the following formula. Further, 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 Co., Ltd.). In the following formula, n is a refractive index at 400 nm, and a value obtained by a refractive index measuring method to be described later is used.

Internal transmittance (400 nm) (%) = light transmittance at 400 nm (%) / (1-r) ²

r={(n-1)/(n+1)} ²

[refractive index]

The secondary cured product obtained above was measured for refractive index at 25 ° C and 589 nm using a refractometer ("Model 2010" manufactured by Metricon Co., Ltd.) in accordance with JIS K7142.

[Abbe number]

The Abbe number of the secondary hardened material obtained above was calculated by the following formula.

Abbe number = (nd-1) / (nF-nC)

(wherein, nd represents a refractive index of 589.2 nm, nF represents a refractive index of 486.1 nm, and nC represents a refractive index of 656.3 nm. Further, in terms of the value of the refractive index, the aforementioned refractive index measuring method is used, And the value of the refractive index obtained for each of the aforementioned wavelengths).

[Volume shrinkage rate]

The volume shrinkage (%) of the secondary hardened material obtained above was measured by using an electronic hydrometer ("SD-200L" manufactured by Shimadzu Corporation) to measure the specific gravity (G1) of the curable composition at 25 ° C and twice. The specific gravity (G2) of the cured product was calculated by 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 a TMA measuring device ("TMA/SS100" manufactured by SII Nanotechnology Co., Ltd.), and is based on JIS K7197. Under the nitrogen atmosphere, the coefficient of thermal expansion of the temperature range of 30 to 250 ° C was measured at a heating rate of 5 ° C / min, and a tangent was drawn on the curve before and after the glass transition point, and the intersection of these tangent lines was obtained.

[Linear expansion coefficient]

The linear expansion coefficient of the secondary hardened material obtained above was measured by a TMA measuring apparatus ("TMA/SS100" manufactured by SII Nanotechnology Co., Ltd.) in accordance with JIS K7197, at a temperature rising rate of 5 ° C under nitrogen atmosphere. After measuring the coefficient of thermal expansion in the temperature range of 30 to 250 ° C, the linear slope α1 of the side lower than the glass transition point and the linear slope α2 of the side of the high temperature of the glass transition point were obtained as the linear expansion coefficients.

[Heat resistance test (evaluation of yellowing resistance under reflow conditions)]

In the above-mentioned secondary hardened material, a tabletop reflow furnace (manufactured by Shinapex Co., Ltd.) was used, and the heat resistance test of the reflow condition of the highest temperature of 270 ° C was continuously performed three times in accordance with the temperature pattern described in the JEDEC standard, and then The measurement method was carried out by measuring the light transmittance at 400 nm and the refractive index at 400 nm, and obtaining the internal light transmittance after the heat resistance test. From the internal light transmittance before and after the heat resistance test, the yellowing rate (%) was calculated by the following formula, and the heat resistance was evaluated. Further, the smaller the yellowing rate, the better the heat resistance of the cured product.

Yellowing rate (%) = {(internal transmittance before heat resistance test) - (internal transmittance after heat resistance test)} / (internal transmittance before heat resistance test) × 100

[Releasability]

In the preparation of the cured product (wafer level lens), the release property at the time of releasing the cured product (primary cured product) from the mold was evaluated by the following criteria.

○ (Extraction property is extremely good): When molding is performed five times in a row, mold release failure such as cracking of a cured product (molded product) does not occur.

△ (good mold release property) When the molding was performed five times in a row, mold release failure such as cracking of the cured product occurred once.

× (defective mold release property): When the molding was performed five times in a row, the mold release failure such as cracking of the cured product occurred twice or more.

[Lens position deviation]

The center positions of the seven lenses formed on the obtained cured product (molded product) were measured by an image size measuring device (trade name "IM-6020", manufactured by Keyence Co., Ltd.), and the lens center position was measured from the mold. Deviation of the design values and calculate the average.

The results obtained are shown in Table 2.

The curable composition obtained in the examples and the cured product thereof were compared with the case of using the alicyclic epoxy compound having an ester group as in Comparative Example 1, and the fast curing property (high curing rate) and heat resistance were observed. Preferably, it is superior as a lens material. Further, in Comparative Example 2, in the thermal cation hardening system containing no compound having an alicyclic epoxy group, no hardening was observed at all, and evaluation as a lens material could not be performed. Further, the hardenable composition obtained in the examples and the cured product thereof were compared with the thermal radical curing system of Comparative Example 3, except that the volume shrinkage ratio was small and the shape stability was excellent. In addition to the good tendency, the mold release property and the positional deviation are not problematic, and therefore, it is excellent as a lens material in terms of molding workability and performance.

[Industrial availability]

The wafer level lens of the present invention can be obtained by curing and molding the curable composition for a wafer level lens of the present invention. The wafer level lens of the present invention can be suitably used as a photographic lens, an eyeglass lens, and a beam set as, for example, a camera (a car camera, a digital camera, a PC camera, a mobile phone camera, a surveillance camera, etc.) in various optical devices. Optical lens, lens for light diffusion, and the like.

Claims (25)

A curable composition for a wafer-level lens, characterized in that it comprises a curable composition of an alicyclic epoxy compound (A) having no ester group and a cationically polymerizable compound (B) having an aromatic ring, The alicyclic epoxy compound (A) which does not have an ester group is a compound having at least two epoxidized cyclic olefin groups. The curable composition for a wafer-level lens according to claim 1, wherein the epoxidized cyclic olefin group is a group in which a cyclic olefin group having 5 to 12 carbon atoms is epoxidized. The hardenable composition for a wafer level lens according to claim 1 or 2, wherein the alicyclic epoxy compound (A) having no ester group has at least 2 epoxidized cyclic olefin groups as a single bond or 2 A compound of a structure in which a valence hydrocarbon group is bonded. The curable composition for a wafer-level lens according to any one of claims 1 to 3, wherein the alicyclic epoxy compound (A) having no ester group is a compound represented by the following formula (a2): [In the formula (a2), X represents a single bond or a divalent hydrocarbon group]. The hardenable composition for a wafer-level lens according to any one of claims 1 to 4, wherein the content of the alicyclic epoxy compound (A) having no ester group is relative to the total amount of the hardenable composition (100) The weight %) is 10 to 60% by weight. The curable composition for a wafer-level lens according to any one of claims 1 to 5, wherein the cationically polymerizable compound (B) having an aromatic ring is selected from the group consisting of At least one cationically curable functional group in the group consisting of an alicyclic epoxy group, a glycidyl group, and an oxetanyl group. The curable composition for a wafer-level lens according to any one of claims 1 to 6, wherein the content of the cationically polymerizable compound (B) having an aromatic ring is relative to the total amount of the curable composition (100% by weight) , 40 to 90% by weight. The curable composition for a wafer level lens according to any one of claims 1 to 7, which further comprises a thermal cation hardener (C). A hardenable composition for a wafer level lens according to claim 8, wherein the hardening start temperature is 60 to 150 °C. The curable composition for a wafer-level lens according to any one of claims 1 to 9, wherein the hardened material obtained by hardening has an Abbe number of 35 or less. The curable composition for a wafer-level lens according to any one of claims 1 to 10, further comprising a mold release agent having a cationic hardening functional group. A method of manufacturing a wafer level lens, characterized in that the curable composition for a wafer level lens according to any one of claims 1 to 11 is subjected to a casting molding method or an injection molding method. The method of manufacturing a wafer level lens according to claim 12, wherein the casting molding method comprises the steps of: step 1a: preparing a wafer-level lens forming mold having one or more lens molds; and step 2a: making the wafer a step of contacting the curable composition for the lens for the wafer-level lens molding die; and step 3a: a step of curing the curable composition for the wafer-level lens by heating and/or light irradiation. The method of fabricating a wafer level lens of claim 13, wherein the casting method further comprises the step of: step 4a: annealing the hardened wafer level lens with a hardenable composition. The method of manufacturing a wafer level lens according to claim 13 or 14, wherein the casting method further comprises the step of: step 5a: cutting the hardened wafer level lens with a curable composition. The method of manufacturing a wafer level lens according to claim 12, wherein the injection molding method comprises the steps of: step 1b: preparing a wafer level lens molding die having one or more lens molds; and step 2b: transferring the wafer The step of emitting the curable composition for the step lens into the mold for forming a wafer level lens; and the step of curing the curable composition for the wafer level lens by heating and/or light irradiation. The method of fabricating a wafer level lens of claim 16, wherein the injection molding method further comprises the step of: step 4b: annealing the hardened wafer level lens with a hardenable composition. A wafer level lens sheet obtained by the method of fabricating a wafer level lens of claim 13 or 14. A wafer level lens obtained by the method of fabricating a wafer level lens according to any one of claims 12 to 17. An optical device loaded with a wafer level lens as claimed in claim 19. A laminated wafer level lens which is a laminate of a plurality of wafer level lenses, and which has at least a wafer level as claimed in any one of claims 1 to 11 for forming a wafer level lens of the laminate A wafer-level lens obtained by hardening and molding a lens with a hardenable composition. A method for manufacturing a laminated wafer level lens, which is the method for manufacturing a multilayer wafer level lens of claim 21, comprising the steps of: Step 1c: preparing a wafer level lens molding mold having one or more lens molds Step 2c: a step of bringing the curable composition for a wafer level lens according to any one of claims 1 to 11 into contact with the wafer level lens molding die; and step 3c: heating and/or light a step of curing the wafer-level lens with a curable composition to obtain a wafer-level lens sheet; and step 4c: stacking a plurality of wafer-level lens sheets including the wafer-level lens sheet to obtain a wafer-level lens sheet Step of laminating the body; Step 5c: a step of cutting the wafer-level lens sheet laminate. The method for manufacturing a multilayer wafer level lens according to claim 22, further comprising the step of: step 6c: annealing the wafer level lens sheet to a step of step 3c and step 4c. A wafer level lens sheet laminate obtained by laminating a plurality of wafer level lens sheets of a wafer level lens sheet of claim 18. An optical device loaded with a stacked wafer level lens as claimed in claim 21.