Curable resin composition and cured product

Abstract

To provide: a curable resin composition for forming a cured material having a high refractive index and excellent flexibility; and a cured material.SOLUTION: A curable resin composition comprises a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, where a mixing ratio of the monofunctional aromatic ring-containing (meth)acrylate relative to the total amount of these is 20 mass% or less, or a curable resin composition comprises a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, where a mixing ratio of the monofunctional aromatic ring-containing (meth)acrylate relative to the total amount of these is 15 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition and a cured product. [Background technology]

[0002] 2. Description of the Related Art Resin materials have traditionally been used for various optical components because they are lightweight and have excellent toughness and moldability.

[0003] As such a resin material, for example, an inkjet ink composition containing an active energy ray-curable compound and a photopolymerization initiator has been proposed (see, for example, Patent Document 1). Furthermore, the refractive index of the cured product of such an inkjet ink composition is 1.624, and the storage modulus is 450 MPa (see, for example, Example 1 of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 088461 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, the cured product of such a resin material is required to have both a high refractive index and flexibility depending on the purpose and application. However, if the density of the resin is increased to increase the refractive index, the flexibility tends to decrease. Therefore, it is not possible to achieve both a high refractive index and flexibility.

[0006] The present invention provides a curable resin composition for forming a cured product having a high refractive index and excellent flexibility, and the cured product. [Means for solving the problem]

[0007] The present invention [1] is a curable resin composition comprising a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, wherein the blending ratio of the polyfunctional thio(meth)acrylate is 20 mass% or less relative to the total amount of the polyfunctional thio(meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate.

[0008] The present invention [2] is a curable resin composition comprising a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, wherein the blending ratio of the polyfunctional fluorene skeleton-containing (meth)acrylate is 15 mass% or less relative to the total amount of the polyfunctional fluorene skeleton-containing (meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate.

[0009] The present invention [3] includes a cured product obtained by curing the curable resin composition described in [1] or [2] above. [Effects of the Invention]

[0010] The curable resin composition of the present invention contains a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, and the polyfunctional thio(meth)acrylate is blended in a predetermined ratio relative to the total amount of these, or contains a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, and the polyfunctional fluorene skeleton-containing (meth)acrylate is blended in a predetermined ratio relative to the total amount of these, thereby enabling the formation of a cured product having a high refractive index and excellent flexibility.

[0011] The cured product of the present invention is obtained by curing the curable resin composition of the present invention, and therefore has a high refractive index and excellent flexibility. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention is a curable resin composition containing a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate (first invention), or a curable resin composition containing a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate (second invention).

[0013] The first and second inventions will be described in detail below.

[0014] <First Invention> The curable resin composition contains a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate. As will be described in detail later, the polyfunctional thio(meth)acrylate is blended in a predetermined proportion relative to the total amount of the polyfunctional thio(meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate.

[0015] [Multifunctional thio(meth)acrylate] The multifunctional thio(meth)acrylate is a multifunctional thiomethacrylate and / or a multifunctional thioacrylate. The multifunctional thio(meth)acrylate has two or more (meth)acryloylthio groups.

[0016] The (meth)acryloylthio group is represented by the following general formula (1). [ka] In the above general formula (1), R 1 represents a hydrogen atom or a methyl group.

[0017] Since the (meth)acryloylthio group contains a sulfur atom, it has a higher refractive index than a (meth)acryloyl group that does not contain a sulfur atom. Therefore, the polyfunctional thio(meth)acrylate can increase the refractive index even without having a molecular structure for increasing the refractive index, such as an aromatic ring. In other words, the polyfunctional thio(meth)acrylate preferably does not have an aromatic ring.

[0018] The polyfunctional thio(meth)acrylate is represented, for example, by the following general formula (2). [ka] In the above general formula (2), R 1 has the same meaning as in the general formula (1). 1 preferably represents a hydrogen atom.

[0019] R 2 represents a divalent hydrocarbon group, preferably a divalent aliphatic hydrocarbon group. Examples of divalent aliphatic hydrocarbon groups include linear alkylene groups (e.g., methylene, ethylene, propylene, butylene, and hexylene) and branched alkylene groups (e.g., isopropylene and isobutylene), preferably linear alkylene groups, more preferably methylene and ethylene groups, and even more preferably ethylene groups. Furthermore, any hydrogen groups may be substituted with acryloylthiomethyl groups or methacryloylthiomethyl groups. Such polyfunctional thio(meth)acrylates are represented, for example, by the following general formula (3) and the following general formula (4). [ka] [ka]

[0020] n represents an integer of 1 or more and 4 or less, and preferably represents 2.

[0021] Among such polyfunctional thio(meth)acrylates, preferred are bifunctional thio(meth)acrylates, and more preferred are compounds represented by the following general formula (5) (in the above general formula (2), R 1 indicates a hydrogen atom, and R 2 represents an ethylene group, and n represents 2. [ka]

[0022] The polyfunctional thio(meth)acrylate can be produced, for example, in accordance with the production method described in Japanese Patent Publication No. 07-091262.

[0023] The polyfunctional thio(meth)acrylates can be used alone or in combination of two or more kinds.

[0024] Furthermore, the polyfunctional thio(meth)acrylate may contain a compound (oligomer) in which the above general formula (2) is polymerized, as long as it does not affect the practice of the present invention.

[0025] [Monofunctional aromatic ring-containing (meth)acrylate] The monofunctional aromatic ring-containing (meth)acrylate is a monofunctional aromatic ring-containing methacrylate and / or a monofunctional aromatic ring-containing acrylate. The monofunctional aromatic ring-containing (meth)acrylate has one (meth)acryloyl group (methacryloyl group and / or acryloyl group) and one or more aromatic rings.

[0026] Examples of monofunctional aromatic ring-containing (meth)acrylates include monofunctional aromatic ring-containing (meth)acrylates having one (meth)acryloyl group and one aromatic ring (hereinafter referred to as first monofunctional aromatic ring-containing (meth)acrylates), monofunctional aromatic ring-containing (meth)acrylates having one (meth)acryloyl group and two aromatic rings (hereinafter referred to as second monofunctional aromatic ring-containing (meth)acrylates), and monofunctional aromatic ring-containing (meth)acrylates having one (meth)acryloyl group and three or more aromatic rings (hereinafter referred to as third monofunctional aromatic ring-containing (meth)acrylates).

[0027] In a monofunctional aromatic ring-containing (meth)acrylate, the inclusion of an aromatic ring can increase the refractive index, but tends to decrease flexibility. From the viewpoint of achieving both refractive index and flexibility, the number of aromatic rings in the monofunctional aromatic ring-containing (meth)acrylate is preferably 1 or 2. In other words, as the monofunctional aromatic ring-containing (meth)acrylate, a first monofunctional aromatic ring-containing (meth)acrylate and a second monofunctional aromatic ring-containing (meth)acrylate are preferably selected.

[0028] The first monofunctional aromatic ring-containing (meth)acrylate is represented, for example, by the following general formula (6). [ka] In the above general formula (6), R 1 has the same meaning as in the general formula (1). 1 preferably represents a hydrogen atom.

[0029] R 4 is the above R 2 Similar to R 4 is preferably a methylene group or an ethylene group. Furthermore, l is 0 or 1, and is preferably 1 from the viewpoint of improving flexibility. Specifically, as described above, the inclusion of an aromatic ring can increase the refractive index, but tends to decrease flexibility. Therefore, in order to ensure flexibility, a monofunctional aromatic ring-containing (meth)acrylate with reduced rigidity is preferably selected. In particular, when l is 1, the internal rotation of the aromatic ring relative to the (meth)acryloyl group is not restricted, and the rigidity can be reduced.

[0030] R 5 represents an oxygen atom or a sulfur atom, and preferably represents an oxygen atom. Also, m represents 0 or 1. Specifically, when l is 1, m represents 0 or 1, and when l is 0, m represents 0.

[0031] R 6represents a halogen atom or an alkyl group (for example, a methyl group or an ethyl group), and n represents an integer of 0 or more and 5 or less.

[0032] Among such first monofunctional aromatic ring-containing (meth)acrylates, benzyl acrylate (represented by the general formula (6) above, R 1 indicates a hydrogen atom, and R 4 represents a methylene group, l represents 1, m represents 0, and n represents 0), and 2-phenoxyethyl acrylate (in the above general formula (6), R 1 indicates a hydrogen atom, and R 4 represents an ethylene group, and R 5 represents an oxygen atom, l represents 1, m represents 1, and n represents 0.

[0033] The second monofunctional aromatic ring-containing (meth)acrylate is represented, for example, by the following general formula (7). [ka] In the above general formula (7), R 1 has the same meaning as in the general formula (1). 1 preferably represents a hydrogen atom.

[0034] R 4 R has the same meaning as in the general formula (6). 4 preferably represents a methylene group or an ethylene group, and more preferably represents a methylene group. Furthermore, l has the same meaning as in the above general formula (6). From the viewpoint of improving flexibility, l is preferably 1.

[0035] R 5 has the same meaning as in the above general formula (6). Also, m has the same meaning as in the above general formula (6). m is preferably 0.

[0036] R 7 represents an oxygen atom, a sulfur atom, the above-mentioned linear alkylene group, or the above-mentioned branched alkylene group. 7preferably represents an oxygen atom. Furthermore, o represents 0 or 1, and is preferably 1 from the viewpoint of improving flexibility. Specifically, similar to the above-mentioned l, when o is 1, rigidity can be reduced and flexibility can be improved.

[0037] R 8 is the above R 6 Further, p represents an integer of 0 or more and 4 or less, and preferably represents 0.

[0038] R 9 is the above R 8 Similar to R 8 and R 9 may be the same or different. q represents an integer of 0 or more and 5 or less, and preferably represents 0.

[0039] Among such second monofunctional aromatic ring-containing (meth)acrylates, preferred are compounds represented by the following general formula (8) (m-phenoxybenzyl acrylate, R 1 indicates a hydrogen atom, and R 4 represents a methylene group, and R 7 represents an oxygen atom, l represents 1, m represents 0, o represents 1, p represents 0, and q represents 0. [ka]

[0040] The second monofunctional aromatic ring-containing (meth)acrylate is represented by, for example, the following general formula (9). [ka]

[0041] In the above general formula (9), R 1 has the same meaning as in the general formula (1). 1 preferably represents a hydrogen atom.

[0042] R 4R has the same meaning as in the general formula (6). 4 preferably represents a methylene group or an ethylene group. Furthermore, l has the same meaning as in the above general formula (6). From the viewpoint of improving flexibility, l is preferably 1.

[0043] R 5 R has the same meaning as in the general formula (6). 5 represents an oxygen atom, and m has the same meaning as in the above general formula (6).

[0044] Among such second monofunctional aromatic ring-containing (meth)acrylates, 1-naphthylmethyl acrylate (represented by the general formula (9) above, R 1 indicates a hydrogen atom, and R 4 represents a methylene group, l represents 1, and m represents 0.) and 2-(1-naphthoxy)ethyl acrylate (in the above general formula (9), R 1 indicates a hydrogen atom, and R 4 represents an ethylene group, and R 5 represents an oxygen atom, l represents 1, and m represents 1.

[0045] The second monofunctional aromatic ring-containing (meth)acrylate is preferably represented by the above general formula (6), and more preferably represented by the above formula (8).

[0046] As the monofunctional aromatic ring-containing (meth)acrylate, a second monofunctional aromatic ring-containing (meth)acrylate is preferably used, from the viewpoint of further increasing the refractive index.

[0047] The monofunctional aromatic ring-containing (meth)acrylates can be used alone or in combination of two or more kinds.

[0048] [Ratio of each compound to the total amount of polyfunctional thio(meth)acrylate and monofunctional aromatic ring-containing (meth)acrylate] The blending ratio of the polyfunctional thio(meth)acrylate relative to the total amount of the polyfunctional thio(meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate is 20 mass% or less, preferably 15 mass% or less, more preferably 10 mass% or less, and for example, 1 mass% or more, preferably 5 mass% or more.

[0049] When the blending ratio of the polyfunctional thio(meth)acrylate is equal to or less than the above upper limit, a cured product having a high refractive index and excellent flexibility can be formed.

[0050] On the other hand, if the blending ratio of the polyfunctional thio(meth)acrylate exceeds the upper limit, the flexibility is significantly reduced, and as a result, it is not possible to achieve both a high refractive index and flexibility.

[0051] Furthermore, when the blending ratio of the polyfunctional thio(meth)acrylate is equal to or greater than the above lower limit, a cured product having a high refractive index and excellent flexibility can be formed.

[0052] Furthermore, the blending ratio of the monofunctional aromatic ring-containing (meth)acrylate relative to the total amount of the polyfunctional thio(meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate is 80 mass% or more, preferably 85 mass% or more, more preferably 90 mass% or more, and for example, 99 mass% or less, preferably 95 mass% or less.

[0053] When the blending ratio of the monofunctional aromatic ring-containing (meth)acrylate is equal to or greater than the above lower limit or equal to or less than the above upper limit, a cured product having a high refractive index and excellent flexibility can be formed.

[0054] [Preparation of Curable Resin Composition] The curable resin composition can be prepared by blending a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate.

[0055] In the above preparation, a monofunctional thio(meth)acrylate may also be added. The monofunctional thio(meth)acrylate has one (meth)acryloylthio group.

[0056] In the above preparation, a polymerization initiator may also be added.

[0057] As the polymerization initiator, a photopolymerization initiator is selected when the curable resin composition is cured by ultraviolet light, and a thermal polymerization initiator is selected when the curable resin composition is cured by heat. Preferably, a photopolymerization initiator is selected as the polymerization initiator.

[0058] Examples of the photopolymerization initiator include acylphosphine oxide initiators, oxyphenylacetic acid ester initiators, benzoylformic acid initiators, and hydroxyphenyl ketone initiators (e.g., 1-hydroxycyclohexyl phenyl ketone), and preferably, hydroxyphenyl ketone initiators.

[0059] The polymerization initiators can be used alone or in combination of two or more kinds.

[0060] The mixing ratio of the polymerization initiator with respect to the curable resin composition is, for example, 0.1 mass % or more, preferably 0.5 mass % or more, and for example, 5 mass % or less, preferably 3 mass % or less.

[0061] In the above preparation, various additives such as tackifiers, fillers, curing accelerators, plasticizers, surfactants, heat stabilizers, antioxidants, flame retardants, antistatic agents, antifoaming agents, leveling agents, and ultraviolet absorbers may be added in appropriate proportions as needed depending on the purpose and application.

[0062] In this way, a curable resin composition is prepared.

[0063] <Second Invention> The curable resin composition contains a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate. As will be described in detail later, the polyfunctional fluorene skeleton-containing (meth)acrylate is blended at a predetermined ratio relative to the total amount of the polyfunctional fluorene skeleton-containing (meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate.

[0064] [Multifunctional fluorene skeleton-containing (meth)acrylate] The polyfunctional fluorene skeleton-containing (meth)acrylate contains two or more (meth)acryloyl groups and a fluorene skeleton. The polyfunctional fluorene skeleton-containing (meth)acrylate can have a high refractive index because it contains a fluorene skeleton.

[0065] The polyfunctional fluorene skeleton-containing (meth)acrylate is represented by, for example, the following general formula (10). [ka]

[0066] In the above general formula (10), R 1 has the same meaning as in the general formula (1). 1 preferably represents a methyl group.

[0067] R 10 is the above R 2 Similar to R 10 preferably represents a methylene group or an ethylene group, and more preferably represents an ethylene group. Furthermore, r represents 0 or 1, and more preferably represents 1. Specifically, similar to the above-mentioned l, when r is 1, rigidity can be reduced and flexibility can be improved.

[0068] R 11represents an oxygen atom or a sulfur atom, and preferably represents an oxygen atom. Also, s represents 0 or 1. Specifically, when r is 1, s represents 0 or 1, and when r is 0, s represents 0. Preferably, s represents 1. Specifically, similar to the above-mentioned l, when s is 1, rigidity can be reduced and flexibility can be improved.

[0069] R 12 is the above R 10 Similar to R 12 R preferably represents a methylene group or an ethylene group, and more preferably represents an ethylene group. 10 and R 12 may be the same or different. 10 and R 12 are preferably the same. Furthermore, t represents 0 or 1, and preferably represents 1. Specifically, similar to the above-mentioned l, when t is 1, the rigidity can be reduced and the flexibility can be improved.

[0070] R 13 is the above R 11 Similar to R 13 R preferably represents an oxygen atom. 11 and R 13 may be the same or different. 11 and R 13 are preferably the same. Also, u represents 0 or 1. Specifically, when t is 1, u represents 0 or 1, and when t is 0, u represents 0. u preferably represents 1. Specifically, similarly to the above-mentioned l, when u is 1, rigidity can be reduced and flexibility can be improved.

[0071] Among such polyfunctional fluorene skeleton-containing (meth)acrylates, preferred are compounds represented by the following general formula (11) (in the above general formula (10), R 1 indicates a methyl group, and R 10 represents an ethylene group, and R 11 indicates an oxygen atom, and R 12 represents an ethylene group, and R 13represents an oxygen atom, r represents 1, s represents 1, t represents 1, and u represents 1. [ka]

[0072] The polyfunctional fluorene skeleton-containing (meth)acrylates can be used alone or in combination of two or more kinds.

[0073] [Monofunctional aromatic ring-containing (meth)acrylate] Examples of the monofunctional aromatic ring-containing (meth)acrylate include the same monofunctional aromatic ring-containing (meth)acrylate as in the first invention described above, preferably a second monofunctional aromatic ring-containing (meth)acrylate, more preferably a second monofunctional aromatic ring-containing (meth)acrylate represented by the general formula (8) above.

[0074] [Ratio of each compound to the total amount of polyfunctional fluorene skeleton-containing (meth)acrylate and monofunctional aromatic ring-containing (meth)acrylate] The blending ratio of the polyfunctional fluorene skeleton-containing (meth)acrylate relative to the total amount of the polyfunctional fluorene skeleton-containing (meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate is 15 mass% or less, preferably 13 mass% or less, more preferably 10 mass% or less, and for example, 1 mass% or more, preferably 5 mass% or more.

[0075] When the blending ratio of the polyfunctional fluorene skeleton-containing (meth)acrylate is equal to or less than the above upper limit, a cured product having a high refractive index and excellent flexibility can be formed.

[0076] On the other hand, if the blending ratio of the polyfunctional fluorene skeleton-containing (meth)acrylate exceeds the upper limit, flexibility is significantly reduced, and as a result, it is not possible to achieve both a high refractive index and flexibility.

[0077] Furthermore, when the blending ratio of the polyfunctional fluorene skeleton-containing (meth)acrylate is equal to or greater than the above lower limit, a cured product having a high refractive index and excellent flexibility can be formed.

[0078] Furthermore, the blending ratio of the monofunctional aromatic ring-containing (meth)acrylate relative to the total amount of the polyfunctional fluorene skeleton-containing (meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate is 85 mass% or more, preferably 87 mass% or more, more preferably 90 mass% or more, and for example, 99 mass% or less, preferably 95 mass% or less.

[0079] When the blending ratio of the monofunctional aromatic ring-containing (meth)acrylate is equal to or greater than the above lower limit or equal to or less than the above upper limit, a cured product having a high refractive index and excellent flexibility can be formed.

[0080] [Preparation of Curable Resin Composition] The curable resin composition can be prepared by blending a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate.

[0081] In the above preparation, a monofunctional fluorene skeleton-containing (meth)acrylate can also be blended in. The monofunctional fluorene skeleton-containing (meth)acrylate contains one (meth)acryloyl group and a fluorene skeleton.

[0082] In the above preparation, the same polymerization initiator as in the first invention and the same additives as in the first invention can also be blended.

[0083] In this way, a curable resin composition is prepared.

[0084] <Action and effect> The curable resin composition contains a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, and the polyfunctional thio(meth)acrylate is blended in a predetermined ratio relative to the total amount of these, or contains a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, and the polyfunctional fluorene skeleton-containing (meth)acrylate is blended in a predetermined ratio relative to the total amount of these, thereby enabling the formation of a cured product having a high refractive index and excellent flexibility.

[0085] The cured product is obtained by curing the curable resin composition. That is, the cured product is obtained by curing the curable resin composition.

[0086] To cure the curable resin composition to form a cured product, if the curable resin composition contains a photopolymerization initiator, the curable resin composition is irradiated with ultraviolet light and then heated as necessary, or if the curable resin composition contains a thermal polymerization initiator, the curable resin composition is heated.

[0087] This gives a cured product.

[0088] The cured product is obtained by curing the curable resin composition, and therefore has a high refractive index and excellent flexibility.

[0089] The refractive index is, for example, 1.600 or more, preferably 1.602, and for example, 2.000 or less.

[0090] The method for measuring the refractive index will be described in detail in the examples below.

[0091] The storage modulus (25°C) of the cured product is, for example, 300 MPa or less, preferably 150 MPa or less, more preferably 100 MPa or less, and even more preferably 60 MPa or less, and for example, 1 MPa or more.

[0092] The method for measuring the storage modulus will be described in detail in the examples below.

[0093] The glass transition temperature of the cured product is, for example, 40°C or less, preferably 30°C or less, and for example, 10°C or more.

[0094] The method for measuring the glass transition temperature will be described in detail in the Examples below.

[0095] The cured product has an Abbe number of, for example, 20 or more, or preferably 25 or more, and for example, 40 or less.

[0096] The method for measuring the Abbe number will be described in detail in the examples below.

[0097] The above-described curable resin composition can form a cured product having a high refractive index and excellent flexibility, and is therefore suitable for use in various optical components (e.g., optical lenses, optical films, optical hard coating agents, optical adhesives, and organic EL encapsulants).

[0098] In particular, optical adhesives used in foldable displays are required to have a high refractive index to suppress light reflection that occurs at the interface with the adhesive substrate, and also to have high flexibility to follow the deformation of the adhesive substrate.

[0099] On the other hand, the above-mentioned curable resin composition and the above-mentioned cured product have a high refractive index and excellent flexibility, and therefore can be suitably used in optical adhesives used in the above-mentioned foldable displays.

[0100] <Modification> In the modified example, the same components and steps as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. Furthermore, the modified example can achieve the same effects as those in the first embodiment unless otherwise specified. Furthermore, the first embodiment and the modified example can be combined as appropriate.

[0101] In the above description, the first invention is a curable resin composition containing a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, and the second invention is a curable resin composition containing a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate. Meanwhile, the first invention may further contain a polyfunctional fluorene skeleton-containing (meth)acrylate, and the second invention may further contain a polyfunctional thio(meth)acrylate. In other words, the curable resin composition may contain a polyfunctional thio(meth)acrylate, a polyfunctional fluorene skeleton-containing (meth)acrylate, and a monofunctional aromatic ring-containing (meth)acrylate. Preferably, in the first invention, the curable resin composition does not contain a polyfunctional fluorene skeleton-containing (meth)acrylate, but contains a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate. Also, in the second invention, the curable resin composition does not contain a polyfunctional thio(meth)acrylate, but contains a polyfunctional fluorene skeleton-containing (meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate. [Example]

[0102] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Modes for Carrying Out the Invention."

[0103] <Ingredient details> The trade names and abbreviations of the components used in each of the examples and comparative examples are detailed below. MESA: a polyfunctional thio(meth)acrylate represented by the above formula (5) OGSOL EA-0200: Bifunctional fluorene skeleton-containing (meth)acrylate, manufactured by Osaka Gas Chemicals Co., Ltd. POB-A: monofunctional aromatic ring-containing (meth)acrylate (m-phenoxybenzyl acrylate) represented by the above formula (8), manufactured by Kyoeisha Chemical Co., Ltd. Omnirad184: 1-hydroxycyclohexyl phenyl ketone, manufactured by IGM Resins

[0104] <Preparation of polyfunctional thio(meth)acrylate> MESA was prepared in accordance with Example 2 of Japanese Patent Publication No. 7-91262.

[0105] <Preparation of Curable Resin Composition> Example 1, Example 2, and Comparative Examples 1 to 3 The components were blended according to the formulation shown in Table 1 to prepare a liquid curable resin composition.

[0106] In Table 1, the blending composition of the polymerization initiator is shown as the blending ratio relative to the curable resin composition.

[0107] <Preparation of cured product> The curable resin composition of each example and comparative example was sandwiched between a 250 μm thick silicone sheet and a glass substrate (Eagle-XG, Corning) that had been surface-treated with a release agent (Novec1720, 3M) and exposed to an illuminance of 100 mW / cm at 365 nm using an electrodeless light source (H bulb). 2 , cumulative light intensity 1000mJ / cm 2 The curable resin composition was cured under the conditions shown below. Thereafter, the composition was peeled off from the release-treated glass substrate and heated at 80°C for 30 minutes in a nitrogen atmosphere. This gave a cured product.

[0108] <Evaluation> [Refractive index, Abbe number] The refractive index (nd) of the cured products of each Example and Comparative Example at room temperature (25°C) at d-line (wavelength 587.6 nm) was measured using an Abbe refractometer (DR-M4, manufactured by Atago Co., Ltd.). Similarly, nC (wavelength 656.3 nm) and nF (wavelength 486.1 nm) were also measured, and the Abbe number ((nD-1) / (nF-nD)) was calculated from the obtained values. The results are shown in Table 1.

[0109] (glass transition temperature (Tg), storage modulus) For the cured products of each Example and Comparative Example, Tg and storage modulus at 25°C were determined from the solid viscoelasticity measurements. The solid viscoelasticity measurements were carried out under the following conditions, and the temperature at which tan Δ showed a maximum value was taken as Tg. The results are shown in Table 1. (conditions) Device: RSA-G2 (TA Instruments) Deformation mode: tension Temperature range: 0℃~270℃ Temperature rise: 3°C / min Frequency: 1Hz Environment: Nitrogen (N2) atmosphere

[0110] [Table 1]

Claims

1. It contains a polyfunctional thio(meth)acrylate and a monofunctional aromatic ring-containing (meth)acrylate, a blending ratio of the polyfunctional thio(meth)acrylate to the total amount of the polyfunctional thio(meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate is 20 mass% or less; the monofunctional aromatic ring-containing (meth)acrylate has two aromatic rings, The curable resin composition, wherein the polyfunctional thio(meth)acrylate does not have an aromatic ring.

2. The composition contains only a polyfunctional fluorene skeleton-containing (meth)acrylate, a monofunctional aromatic ring-containing (meth)acrylate, and a polymerization initiator; a blending ratio of the polyfunctional fluorene skeleton-containing (meth)acrylate to the total amount of the polyfunctional fluorene skeleton-containing (meth)acrylate and the monofunctional aromatic ring-containing (meth)acrylate is 15 mass% or less; The curable resin composition, wherein the monofunctional aromatic ring-containing (meth)acrylate is m-phenoxybenzyl (meth)acrylate.

3. A cured product obtained by curing the curable resin composition according to claim 1 or 2.

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