Composition, additive, plasticizer, curable composition, adhesive, cured product, and pressure-sensitive adhesive

Abstract

This composition contains a first compound and a second compound. The first compound is a reaction product of a thiol compound having a functional group represented by formula (1) and a carbon-carbon double bond-containing compound represented by formula (2). The second compound is represented by formula (3). (In formula (1), A represents an alkylene group having 2 to 3 carbon atoms. In formula (2), R1, R2, and R3 respectively represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an aromatic aliphatic hydrocarbon group. R1, R2 and R3 may be the same or different. In formula (3), R1, R2, R3, and Ar have the same meaning as R1, R2, R3, and Ar in formula (2).)

Description

Compositions, additives, plasticizers, curable compositions, adhesives, cured products, and pressure-sensitive adhesives

[0001] The present invention relates to a composition, an additive, a plasticizer, a curable composition, an adhesive, a cured product, and a pressure-sensitive adhesive.

[0002] In various optical fields, optical resins are used as adhesives and pressure-sensitive adhesives. Optical resins have a relatively high refractive index. Depending on the application, optical resins may be required to be flexible. Therefore, adding a plasticizer to optical resins is being considered.

[0003] Known examples of plasticizers include dioctyl phthalate (DOP, bis(2-ethylhexyl) phthalate) (see, for example, Patent Document 1).

[0004] JP 2015-105329 A

[0005] When the above-mentioned plasticizer is added to an optical resin, the crystallinity of the optical resin is reduced and the flexibility is improved. However, the reduction in the crystallinity of the optical resin may reduce the refractive index of the optical resin. Furthermore, for example, if the refractive index of the optical resin is not reduced by the plasticizer, the crystallinity of the optical resin may not be reduced sufficiently, and the flexibility may not be improved.

[0006] Therefore, a plasticizer that can improve flexibility without lowering the refractive index is required. Furthermore, depending on the application, optical resins are required to have excellent transparency (suppression of cloudiness) and weather resistance.

[0007] The present invention relates to a composition, an additive, a plasticizer, a curable composition, an adhesive, a cured product, and a pressure-sensitive adhesive for obtaining a cured product that has refractive index, flexibility, transparency, and weather resistance.

[0008] The present invention [1] includes a composition containing a first compound which is a reaction product between a thiol compound having a functional group represented by the following formula (1) and a carbon-carbon double bond-containing compound represented by the following formula (2), and a second compound represented by the following formula (3):

[0009]

[0010] (In formula (1), A represents an alkylene group having 2 to 3 carbon atoms.)

[0011]

[0012] (In formula (2), R1, R2, and R3 represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an araliphatic hydrocarbon group. R1, R2, and R3 may be the same or different.)

[0013]

[0014] (In formula (3), A has the same meaning as A in formula (1). R1, R2, R3 and Ar have the same meaning as R1, R2, R3 and Ar in formula (2).)

[0015] The present invention [2] includes the composition according to the above [1], wherein the thiol compound has a functional group represented by the following formula (4), and the second compound is a compound represented by the following formula (5):

[0016]

[0017]

[0018] (In formula (5), R1, R2, R3, and Ar have the same meanings as R1, R2, R3, and Ar in formula (2).)

[0019] The present invention [3] includes the composition according to the above [1] or [2], wherein the thiol compound is a compound represented by the following formula (6), and the carbon-carbon double bond-containing compound is styrene:

[0020]

[0021] The present invention [4] includes the composition according to any one of the above [1] to [3], wherein, in a chromatogram obtained by high performance liquid chromatography at a detection wavelength of 254 nm, the area ratio of a peak corresponding to the first compound is 45 to 95% of the area of ​​all peaks, and the area ratio of a peak corresponding to the second compound is 0.5 to 10% of the area of ​​all peaks.

[0022] The present invention [5] includes a plasticizer containing the composition according to any one of the above [1] to [4].

[0023] The present invention [6] includes a curable composition containing the plasticizer described in the above [5] and a curable compound.

[0024] The present invention [7] includes an adhesive containing the curable composition described in the above [6].

[0025] The present invention [8] includes a cured product containing the plasticizer described in the above [5] and a cured resin.

[0026] The present invention [9] includes the cured product according to the above [8], wherein the cured resin includes a reaction product of a base agent containing an acrylic polyol and a curing agent containing a polyisocyanate.

[0027] The present invention

[10] includes the cured product according to the above [8], in which the cured resin includes a cured acrylic resin.

[0028] The present invention

[11] includes a pressure-sensitive adhesive containing the cured product described in the above [8].

[0029] The composition, additive, plasticizer, curable composition, and adhesive of the present invention can provide a cured product that has a refractive index, flexibility, transparency, and weather resistance.

[0030] The cured product and adhesive of the present invention contain the above-mentioned composition, and therefore have a refractive index, flexibility, transparency, and weather resistance.

[0031] 1. Composition (1) Constitution of the Composition The composition of the present invention contains at least a first compound, which will be described in detail below, and a second compound, which will be described in detail below.

[0032] 1) First Compound The first compound is a reaction product of a thiol compound and a carbon-carbon double bond-containing compound. The thiol compound and the carbon-carbon double bond-containing compound will be described in detail below.

[0033] [Thiol Compound] The thiol compound has a functional group represented by the following formula (1).

[0034]

[0035] (In formula (1), A represents an alkylene group having 2 to 3 carbon atoms.)

[0036] In formula (1), A represents an alkylene group having 2 to 3 carbon atoms. Examples of the alkylene group having 2 to 3 carbon atoms include an ethylene group (—CH ２ CH ２ -), triethylene group (-CH ２ CH ２ CH ２ -), propylene group (1-methylethylene group, -CH ２ CH (CH ３ )-), and the 2-methylethylene group —CH(CH ３ ) CH ２ -), and preferably an ethylene group (-CH ２ CH ２ That is, in the above formula (1), A is preferably an ethylene group (—CH ２ CH ２ -) is indicated.

[0037] In other words, the thiol compound has a functional group represented by the following formula (4).

[0038]

[0039] The functional group represented by the above formula (4) is a mercaptoethylthio group (HS-CH ２ CH ２ —S—). That is, the thiol compound is a compound containing a mercaptoethylthio group (a mercaptoethylthio group-containing compound). In the above formula (4), the dashed line represents the bond of the mercaptoethylthio group.

[0040] The number of functional groups represented by the above formula (1) (preferably the above formula (4)) is, for example, 1 to 8, preferably 2 to 8, more preferably 2 to 6, and even more preferably 2 to 4, per molecule of the thiol compound.

[0041] The functional group represented by the formula (1) has a mercapto group. That is, the thiol compound has at least one mercapto group derived from the functional group represented by the formula (1). The thiol compound may also contain a mercapto group not derived from the functional group represented by the formula (1).

[0042] In the thiol compound, the number of mercapto groups per molecule of the thiol compound is, for example, 1 to 8, preferably 1 to 6, more preferably 1 to 4, even more preferably 3 to 4, and particularly preferably 3.

[0043] That is, more specifically, examples of thiol compounds include thiol compounds having one mercapto group per molecule (hereinafter referred to as monovalent thiol compounds), thiol compounds having two mercapto groups per molecule (hereinafter referred to as divalent thiol compounds), thiol compounds having three mercapto groups per molecule (hereinafter referred to as trivalent thiol compounds), thiol compounds having four mercapto groups per molecule (hereinafter referred to as tetravalent thiol compounds), thiol compounds having five mercapto groups per molecule (hereinafter referred to as pentavalent thiol compounds), thiol compounds having six mercapto groups per molecule (hereinafter referred to as hexavalent thiol compounds), thiol compounds having seven mercapto groups per molecule (hereinafter referred to as heptavalent thiol compounds), and thiol compounds having eight mercapto groups per molecule (hereinafter referred to as octavalent thiol compounds). These can be used alone or in combination of two or more. Preferably, monovalent to hexavalent thiol compounds are used, and more preferably, monovalent to tetravalent thiol compounds are used.

[0044] Examples of monovalent thiol compounds include mercaptoethylthiomethane. These can be used alone or in combination of two or more. Examples of divalent thiol compounds include bis(mercaptoethylthio)methane and 2,3-dimercapto-1-propanol. Examples of trivalent thiol compounds include tris(mercaptoethylthio)methane and 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST). Examples of tetravalent thiol compounds include tetra(mercaptoethylthio)methane and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (FSH). These can be used alone or in combination of two or more.

[0045] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the thiol compound is preferably a trivalent thiol compound or a tetravalent thiol compound, and more preferably 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST) or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (FSH).

[0046] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the compound having one functional group represented by the above formula (1) is more preferably a trivalent thiol compound, and even more preferably 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST).

[0047] That is, the thiol compound more preferably contains 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST), and more preferably consists of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST).

[0048] 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST) is, for example, represented by the following formula (6): That is, the thiol compound is more preferably a compound represented by the following formula (6). In other words, the thiol compound is more preferably a compound represented by the following formula (6):

[0049]

[0050] [Carbon-Carbon Double Bond-Containing Compound] The carbon-carbon double bond-containing compound is represented by the following formula (2).

[0051] (In formula (2), R1, R2, and R3 represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an araliphatic hydrocarbon group. R1, R2, and R3 may be the same or different. Ar represents an aromatic hydrocarbon group or an araliphatic hydrocarbon group.)

[0052] In the above formula (2), R1, R2, and R3 represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an araliphatic hydrocarbon group.

[0053] Examples of the aliphatic hydrocarbon group include aliphatic hydrocarbon groups having 1 to 20 carbon atoms. More specific examples of the aliphatic hydrocarbon group include linear aliphatic hydrocarbon groups having 1 to 20 carbon atoms and cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms.

[0054] Examples of the linear aliphatic hydrocarbon group having 1 to 20 carbon atoms include a linear saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms and a linear unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the linear saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a 2-butyl group, a 1-pentyl group, a 2-pentyl group, a 3-pentyl group, a 2-methyl-1-butyl group, an isopentyl group, a tert-pentyl group, a 3-methyl-2-butyl group, a neopentyl group, an n-hexyl group, a 4-methyl-2-butyl group, a 5-methyl-1-butyl group, a 6-methyl-2-butyl group, a 7-methyl-2-butyl group, a 8-methyl-2-butyl group, a 9-methyl-2-butyl group, a 10-methyl-2-butyl group, a 20-methyl-2-butyl group, a 21-methyl-2-butyl group, a 22-methyl-2-butyl group, a 23-methyl-2-butyl group, a 24-methyl-2-butyl group, a 25-methyl-2-butyl group, a 26-methyl-2-butyl group, a 27-methyl-2-butyl group, a 28-methyl-2-butyl group, a 29-methyl-2-butyl group, a 30-methyl-2-butyl group, a 31-methyl-2-butyl group, a 32-methyl-2-butyl group, a 33-methyl-2-butyl group, a 34-methyl-2-butyl group, a 35-methyl-2-butyl group, a 36-methyl-2-butyl group, a 37-methyl-2-butyl group, a 38-methyl-2-butyl Examples of the linear unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms include vinyl and 2-propenyl groups. These may be used alone or in combination of two or more.

[0055] Examples of cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms include saturated cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms and unsaturated cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms. Examples of saturated cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl groups. Examples of unsaturated cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms include cyclopentenyl and cyclohexenyl groups. These can be used alone or in combination of two or more types.

[0056] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 to 20 carbon atoms. Examples of aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenyl, 2-tolyl, 3-tolyl, 4-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, 2,3,4-trimethylphenyl, 3,4,5-trimethylphenyl, 2,4,6-trimethylphenyl, 2,3,4,5-tetramethylphenyl, 2,3,4,6-tetramethylphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 1-naphthyl, and 2-naphthyl groups. These groups can be used alone or in combination of two or more.

[0057] Examples of aromatic aliphatic hydrocarbon groups include aromatic aliphatic hydrocarbon groups having 7 to 20 carbon atoms. Examples of aromatic aliphatic hydrocarbon groups having 7 to 20 carbon atoms include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, o-methylbenzyl, m-methylbenzyl, p-methylbenzyl, o-ethylbenzyl, m-ethylbenzyl, p-ethylbenzyl, o-isopropylbenzyl, m-isopropylbenzyl, p-isopropylbenzyl, 2,3,4-trimethylbenzyl, 3,4,5-trimethylbenzyl, and 2,4,6-trimethylbenzyl. These can be used alone or in combination of two or more types.

[0058] The aliphatic hydrocarbon group, aromatic hydrocarbon group, and aromatic aliphatic hydrocarbon group may have a substituent. Examples of the substituent include a halogeno group, a cyano group, an amino group, a carboxy group, a sulfonyl group, and an alkoxy group (an alkoxy group not containing an aromatic ring). These may be used alone or in combination of two or more types. The number of substituents is appropriately determined depending on the purpose and application. The substitution position is appropriately determined depending on the purpose and application.

[0059] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, R1, R2, and R3 preferably all represent a hydrogen atom or an aliphatic hydrocarbon group, and more preferably all represent a hydrogen atom. R1, R2, and R3 may be the same as or different from one another. From the viewpoints of refractive index, flexibility, transparency, and weather resistance, R1, R2, and R3 are preferably the same as one another. That is, it is particularly preferable that R1, R2, and R3 all represent a hydrogen atom.

[0060] In the above formula (2), Ar represents an aromatic hydrocarbon group or an araliphatic hydrocarbon group.

[0061] Examples of the aromatic hydrocarbon group include the aromatic hydrocarbon groups described above, more specifically, the aromatic hydrocarbon groups having 6 to 20 carbon atoms described above. These groups can be used alone or in combination of two or more.

[0062] Examples of the aromatic aliphatic hydrocarbon group include the aromatic aliphatic hydrocarbon groups described above, and more specifically, the aromatic hydrocarbon groups having 7 to 20 carbon atoms described above. These groups can be used alone or in combination of two or more.

[0063] As described above, the aromatic hydrocarbon group and the aromatic aliphatic hydrocarbon group may have the above-mentioned substituents. The substitution positions are appropriately set depending on the purpose and application.

[0064] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, Ar preferably represents an aromatic hydrocarbon group, and more preferably represents a phenyl group.

[0065] More specific examples of the carbon-carbon double bond-containing compound include styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-butylstyrene, and β-methylstyrene. These can be used alone or in combination of two or more.

[0066] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the carbon-carbon double bond-containing compound represented by the above formula (2) is preferably styrene, α-methylstyrene, or α-butylstyrene, and more preferably styrene. That is, the carbon-carbon double bond-containing compound more preferably contains styrene, and even more preferably consists of styrene. In other words, the carbon-carbon double bond-containing compound is more preferably styrene.

[0067] [Production of First Compound] The first compound is produced as a main product by an ene-thiol reaction between the thiol compound and the carbon-carbon double bond-containing compound. That is, the first compound is, for example, the main product of the ene-thiol reaction between the thiol compound and the carbon-carbon double bond-containing compound.

[0068] In the ene-thiol reaction, which will be described in detail later, for example, the functional group of a thiol compound represented by the above formula (1) reacts with the carbon-carbon double bond-containing compound represented by the above formula (2), to form, for example, a functional group represented by the following formula (7).

[0069]

[0070] (In formula (7), A has the same position as A in formula (1). R1, R2, R3, and Ar have the same meanings as R1, R2, R3, and Ar in formula (2).)

[0071] Preferably, the functional group of the thiol compound represented by the above formula (4) reacts with the carbon-carbon double bond-containing compound represented by the above formula (2) to form, for example, a functional group represented by the following formula (8):

[0072]

[0073] (In formula (8), R1, R2, R3, and Ar have the same meanings as R1, R2, R3, and Ar in formula (2).)

[0074] More specifically, when the thiol compound is the thiol compound represented by the above formula (6) (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST)), the main product of the ene-thiol reaction between the thiol compound and the carbon-carbon double bond-containing compound is represented by, for example, the following formula (9):

[0075]

[0076] (In formula (9), R1, R2, R3, and Ar have the same meanings as R1, R2, R3, and Ar in formula (2).)

[0077] The first compound preferably contains a compound represented by the above formula (9), and more preferably consists of a compound represented by the above formula (9).

[0078] Furthermore, when the thiol compound is the compound represented by the above formula (6) (4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST)) and the carbon-carbon double bond-containing compound is styrene, the main product of the ene-thiol reaction is, for example, represented by the following formula (10):

[0079]

[0080] The first compound preferably contains a compound represented by the above formula (10), and particularly preferably consists of a compound represented by the above formula (10). The compound represented by the above formula (10) is 4-phenethylthiomethyl-1,8-bisphenethylthio-3,6-dithiaoctane. Hereinafter, 4-phenethylthiomethyl-1,8-bisphenethylthio-3,6-dithiaoctane may be referred to as "PE-GST."

[0081] 2) Second Compound The second compound is represented by the following formula (3).

[0082]

[0083] (In formula (3), A has the same meaning as A in formula (1). R1, R2, R3 and Ar have the same meaning as R1, R2, R3 and Ar in formula (2).)

[0084] In formula (3), A represents the above-mentioned alkylene group having 2 to 3 carbon atoms. A is preferably an ethylene group (—CH ２ CH ２ That is, the second compound is preferably a compound represented by the following formula (5):

[0085]

[0086] (In formula (5), R1, R2, R3, and Ar have the same meanings as R1, R2, R3, and Ar in formula (2).)

[0087] In formula (3) and formula (5), R1, R2, and R3 represent a hydrogen atom, the aliphatic hydrocarbon group, the aromatic hydrocarbon group, or the araliphatic hydrocarbon group. From the viewpoints of refractive index, flexibility, transparency, and weather resistance, R1, R2, and R3 preferably all represent a hydrogen atom or an aliphatic hydrocarbon group, and more preferably all represent a hydrogen atom. R1, R2, and R3 may be the same as or different from one another. From the viewpoints of refractive index, flexibility, transparency, and weather resistance, R1, R2, and R3 are preferably the same as one another. That is, it is particularly preferable that R1, R2, and R3 all represent a hydrogen atom.

[0088] In formula (3) and formula (5), Ar represents the above-mentioned aromatic hydrocarbon group or the above-mentioned araliphatic hydrocarbon group. From the viewpoints of refractive index, flexibility, transparency, and weather resistance, Ar preferably represents an aromatic hydrocarbon group, more preferably a phenyl group.

[0089] More specifically, the second compound may be, for example, S,S'-diphenethyldimercaptoethane (a compound in which R1, R2, and R3 represent hydrogen atoms and Ar represents a phenyl group). In addition to the above, other second compounds may be, for example, S,S'-bis(2-phenylpropionyl)dimercaptoethane and phenethyl(2-(2-phenylpropionyl)thio)ethyl)sulfane. These may be used alone or in combination of two or more.

[0090] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the second compound represented by the above formula (3) is preferably S,S'-diphenethyldimercaptoethane (a compound in which R1, R2, and R3 represent hydrogen atoms and Ar represents a phenyl group).

[0091] That is, the second compound preferably contains S,S'-diphenethyldimercaptoethane, and more preferably consists of S,S'-diphenethyldimercaptoethane (DPE-DME). In other words, the second compound is more preferably S,S'-diphenethyldimercaptoethane.

[0092] S,S'-diphenethyldimercaptoethane is represented, for example, by the following formula (11): In other words, the second compound is more preferably a compound represented by the following formula (11): Hereinafter, S,S'-diphenethyldimercaptoethane may be referred to as "DPE-DME."

[0093]

[0094] [Production of Second Compound] The second compound is, for example, a by-product in the ene-thiol reaction between the thiol compound and the carbon-carbon double bond-containing compound.

[0095] That is, the second compound is produced as a by-product by subjecting the thiol compound and the carbon-carbon double bond-containing compound to an ene-thiol reaction.

[0096] In the ene-thiol reaction, the thiol compound is cleaved by a side reaction, which will be described in detail later, to form, for example, a thiyl radical corresponding to the above formula (1). The thiyl radical corresponding to the above formula (1) is, for example, represented by the following formula (12).

[0097]

[0098] (In formula (12), A has the same meaning as A in formula (1)).

[0099] Preferably, the ene-thiol reaction forms a thiyl radical corresponding to the functional group represented by formula (4) above (i.e., A is an ethylene group). The thiyl radical corresponding to the functional group represented by formula (4) above is represented, for example, by formula (13) below.

[0100]

[0101] That is, preferably, in the ene-thiol reaction, HSCH ２ CH ２ An S radical is produced as a by-product. Then, in the ene-thiol reaction, the thiyl radical undergoes radical polymerization. Furthermore, the compound obtained by radical polymerization and the carbon-carbon double bond-containing compound undergo an ene-thiol reaction. As a result, the second compound represented by the above formula (2) is formed as a by-product.

[0102] 3) Other Compounds The composition may contain other compounds. The other compounds are compounds other than the first compound and the second compound.

[0103] Examples of other compounds include by-products (excluding the second compound) in the ene-thiol reaction between the thiol compound and the carbon-carbon double bond-containing compound.

[0104] More specifically, other compounds (by-products other than the second compound) include, for example, phenethyl(2-(2,4-diphenylbutyl)thio)ethyl)sulfane, 4-(2,4-diphenylbutyl)thiomethyl-1,8-bisphenethylthio-3,6-dithiaoctane, and structural isomers thereof. These may be used alone or in combination of two or more types.

[0105] The other compounds can be prepared, for example, by the same method as in the production of the second compound described above, using HSCH ２ CH ２ It is formed by radical polymerization of S radicals and ene-thiol reactions.

[0106] (2) Method for Producing the Composition [Ene-Thiol Reaction] The composition is produced by subjecting the thiol compound and the carbon-carbon double bond-containing compound to an ene-thiol reaction. That is, the first compound is synthesized as a main product by the ene-thiol reaction. In addition, along with the production of the first compound, the second compound is synthesized as a by-product. Furthermore, if necessary, the other compounds (compounds other than the first compound and the second compound) are synthesized as by-products. In this manner, a composition containing the first compound and the second compound (and other compounds, if necessary) is produced.

[0107] More specifically, in the ene-thiol reaction, for example, the thiol compound and the carbon-carbon double bond-containing compound are mixed in the presence of a radical polymerization initiator (hereinafter referred to as a radical initiator), and the mixture is heated as necessary.

[0108] [Radical Polymerization Initiator] The radical polymerization initiator is not particularly limited, and known radical polymerization initiators can be used. Examples of the radical polymerization initiator include an active energy ray radical polymerization initiator, which will be described later, and a thermal radical polymerization initiator, which will be described later. These can be used alone or in combination of two or more. As the radical polymerization initiator, a thermal radical polymerization initiator is preferably used, more preferably an azo compound, even more preferably azoisobutyronitrile (AIBN) or 2,2'-azobis(2,4-dimethylvaleronitrile), and particularly preferably 2,2'-azobis(2,4-dimethylvaleronitrile).

[0109] The mixing ratio of the radical polymerization initiator is set so that the first compound and the second compound are produced in a desired ratio.

[0110] [Combination Ratio] In the ene-thiol reaction, the combination ratio of the thiol compound and the carbon-carbon double bond-containing compound is set so that the first compound and the second compound are produced in a desired ratio. More specifically, the combination ratio of the thiol compound and the carbon-carbon double bond-containing compound is adjusted based on the equivalent ratio of the carbon-carbon double bonds in the carbon-carbon double bond-containing compound to the mercapto groups in the thiol compound (carbon-carbon double bond / mercapto group).

[0111] The equivalent ratio of the carbon-carbon double bonds in the carbon-carbon double bond-containing compound to the mercapto groups in the thiol compound (carbon-carbon double bond / mercapto group) is, for example, 0.9 to 5.0, preferably 1.0 to 3.0, and more preferably 1.01 to 1.5.

[0112] [Reaction Conditions] The reaction conditions for the ene-thiol reaction are selected so as to produce the first compound and the second compound in the desired ratio.

[0113] More specifically, from the viewpoint of producing the first compound and the second compound in a desired ratio, the lower limit of the reaction temperature is, for example, 0°C or higher, preferably 10°C or higher, more preferably 20°C or higher, even more preferably 30°C or higher, and particularly preferably 40°C or higher.

[0114] Furthermore, from the viewpoint of producing the first compound and the second compound in a desired ratio, the upper limit of the reaction temperature is, for example, 150°C or less, preferably 100°C or less, more preferably 80°C or less, even more preferably 60°C or less, and particularly preferably 50°C or less.

[0115] That is, from the viewpoint of producing the first compound and the second compound in a desired ratio, the reaction temperature is, for example, 0 to 150°C, preferably 10 to 100°C, more preferably 20 to 80°C, even more preferably 30 to 60°C, and particularly preferably 40 to 50°C.

[0116] The reaction time is, for example, 3 to 120 hours, preferably 6 to 72 hours, more preferably 12 to 60 hours, and even more preferably 24 to 48 hours.

[0117] [Reaction Mechanism] The ene-thiol reaction involves a main reaction and a side reaction.

[0118] In the main reaction, a first compound is produced. More specifically, in the main reaction, the radical polymerization initiator first abstracts a hydrogen atom from the mercapto group of the thiol compound to generate a thiyl radical.

[0119] In the main reaction, the thiyl radical undergoes radical addition to the carbon-carbon double bond of the carbon-carbon double bond-containing compound to generate a carboradical, which then abstracts a hydrogen atom from another mercapto group, thereby completing the alkylation of the mercapto group.

[0120] As a result, the first compound is obtained as the main product in the ene-thiol reaction.

[0121] In the side reaction, a second compound is produced. More specifically, in the side reaction, as in the main reaction, the radical polymerization initiator abstracts a hydrogen atom from the mercapto group of the thiol compound to generate a thiyl radical.

[0122] In a side reaction, the thiyl radical cleaves the molecular chain in the thiol compound to generate another thiyl radical. A thiyl radical (formula (12)) corresponding to the functional group represented by formula (1) is generated. More specifically, when the thiol compound has a functional group represented by formula (4), HSCH ２ CH ２ S radicals (the above formula (13)) are generated.

[0123] Thereafter, the thiyl radical (the above formula (12)) undergoes radical polymerization. Furthermore, the compound obtained by radical polymerization and the carbon-carbon double bond-containing compound undergo an ene-thiol reaction. As a result, the second compound represented by the above formula (2) is formed. More specifically, when the thiol compound has a functional group represented by the above formula (4), the second compound is represented, for example, by the above formula (5).

[0124] That is, a second compound is produced as a by-product in the ene-thiol reaction.

[0125] The by-product in the ene-thiol reaction is not limited to the second compound. For example, the other compounds (compounds other than the first and second compounds) can be produced based on a thiyl radical (formula (12)) corresponding to the functional group represented by formula (1).

[0126] [Reaction Solvent] In the ene-thiol reaction, a reaction solvent is used as needed. That is, the thiol compound and the carbon-carbon double bond-containing compound may react in the absence of a reaction solvent, or may react in the presence of a reaction solvent. Preferably, the thiol compound and the carbon-carbon double bond-containing compound react in the presence of a reaction solvent.

[0127] Examples of reaction solvents include alcohols, ketones, nitriles, alkyl esters, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ethers, glycol ether esters, halogenated aliphatic hydrocarbons, and polar aprotic solvents. Examples of alcohols include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, cyclohexanol, and benzyl alcohol. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of nitriles include acetonitrile. Examples of alkyl esters include methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, and octane. Examples of alicyclic hydrocarbons include cyclohexane and methylcyclohexane. Examples of aromatic hydrocarbons include toluene, xylene, and ethylbenzene. Examples of ethers include diethyl ether, tetrahydrofuran, and dioxane. Examples of glycol ether esters include methyl cellosolve acetate, ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, and ethyl-3-ethoxypropionate. Examples of halogenated aliphatic hydrocarbons include methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, and dichloroethane. Examples of polar aprotic solvents include N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphonylamide. These can be used alone or in combination.The organic solvent is preferably selected so that the first compound and the second compound are produced in a desired ratio. For example, from the viewpoint of increasing the production ratio of the first compound, alkyl esters (more preferably, ethyl acetate) are preferred. Furthermore, from the viewpoint of increasing the production ratio of the second compound, aromatic hydrocarbons (more preferably, toluene) are preferred.

[0128] The organic solvent is selected depending on, for example, the ratio of the first compound to the second compound. As the organic solvent, preferably, alkyl esters and aromatic hydrocarbons are used, and more preferably, alkyl esters are used.

[0129] [Purification] The reaction product of the ene-thiol reaction is purified by a known method, if necessary. The purification method is not particularly limited, and examples thereof include washing, dehydration, impurity adsorption, liquid-liquid extraction, distillation, and recrystallization. These methods may be used alone or in combination of two or more.

[0130] The content ratio of the first compound and the second compound can be adjusted by purifying the reaction product. Alternatively, the content ratio of the first compound and the second compound can be adjusted by setting the reaction conditions without purifying the reaction product.

[0131] As described above, the ene-thiol reaction (and purification) yields a composition containing the first compound and the second compound as the reaction product.

[0132] [Content Ratio] The content ratio of the first compound and the content ratio of the second compound in the composition are calculated, for example, from a chromatogram (hereinafter referred to as a high-performance liquid chromatogram) obtained when the composition is subjected to high-performance liquid chromatography (specifically, high-performance liquid chromatography at a detection wavelength of 254 nm in accordance with the Examples described below).

[0133] More specifically, since the composition contains the first compound and the second compound, when the composition is subjected to high performance liquid chromatography (specifically, high performance liquid chromatography at a detection wavelength of 254 nm in accordance with the Examples described later), the resulting high performance liquid chromatogram has a peak corresponding to the first compound and a peak corresponding to the second compound.

[0134] The peak corresponding to the first compound has a peak top at a retention time corresponding to the molecular structure and polarity of the first compound in a chromatogram (high-performance liquid chromatogram) obtained by high-performance liquid chromatographic measurement at a detection wavelength of 254 nm. Note that the retention time of the peak top depends on the measurement conditions of the high-performance liquid chromatographic measurement.

[0135] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the lower limit of the area ratio of the peak corresponding to the first compound in the above-mentioned high performance liquid chromatogram is, for example, 20% or more, preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and particularly preferably 60% or more, relative to the area of ​​all peaks.

[0136] Furthermore, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the upper limit of the area ratio of the peak corresponding to the first compound in the above-mentioned high performance liquid chromatogram is, for example, 99.5% or less, preferably 99% or less, more preferably 95% or less, even more preferably 90% or less, and particularly preferably 80% or less, relative to the area of ​​all peaks.

[0137] That is, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the area ratio of the peak corresponding to the first compound in the above-mentioned high performance liquid chromatogram is, for example, 20 to 99.5%, preferably 40 to 99%, more preferably 45 to 95%, even more preferably 50 to 90%, and particularly preferably 60 to 80%.

[0138] Furthermore, the area ratio of the peak corresponding to the first compound in the high performance liquid chromatogram of the composition corresponds to the mass ratio of the first compound in the composition.

[0139] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the lower limit of the content of the first compound is, for example, 20 mass% or more, preferably 40 mass% or more, more preferably 45 mass% or more, even more preferably 50 mass% or more, and particularly preferably 60 mass% or more, relative to the total amount of the composition.

[0140] Furthermore, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the upper limit of the content of the first compound is, for example, 99.5 mass% or less, preferably 99 mass% or less, more preferably 95 mass% or less, even more preferably 90 mass% or less, and particularly preferably 80 mass% or less, relative to the total amount of the composition.

[0141] That is, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the content of the first compound is, for example, 20 to 99.5 mass%, preferably 45 to 95 mass%, more preferably 50 to 90 mass%, and particularly preferably 60 to 80 mass%, relative to the total amount of the composition.

[0142] The peak corresponding to the second compound has a peak top at a retention time corresponding to the molecular weight of the second compound in a chromatogram (high-performance liquid chromatogram) obtained by high-performance liquid chromatography at a detection wavelength of 254 nm. Note that the retention time of the peak top depends on the measurement conditions of the high-performance liquid chromatography measurement.

[0143] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the lower limit of the area ratio of the peak corresponding to the second compound in the above-mentioned high-performance liquid chromatogram is, for example, 0.1% or more, preferably 0.3% or more, more preferably 0.5% or more, even more preferably 0.7% or more, and particularly preferably 1.0% or more, relative to the area of ​​all peaks.

[0144] Furthermore, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the upper limit of the area ratio of the peak corresponding to the second compound in the above-mentioned high-performance liquid chromatogram is, for example, 30% or less, preferably 20% or less, more preferably 10% or less, even more preferably 5.0% or less, and particularly preferably 2.0% or less, relative to the area of ​​all peaks.

[0145] That is, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the area ratio of the peak corresponding to the second compound in the above-mentioned high performance liquid chromatogram is, for example, 0.1 to 30%, preferably 0.3 to 20%, more preferably 0.5 to 10%, even more preferably 0.7 to 5.0%, and particularly preferably 1.0 to 2.0%.

[0146] Furthermore, the area ratio of the peak corresponding to the second compound in the high performance liquid chromatogram of the composition corresponds to the mass ratio of the second compound in the composition.

[0147] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the lower limit of the content of the second compound is, for example, 0.1 mass% or more, preferably 0.3 mass% or more, more preferably 0.5 mass% or more, even more preferably 0.7 mass% or more, and particularly preferably 1.0 mass% or more, relative to the total amount of the composition.

[0148] Furthermore, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the upper limit of the content of the second compound is, for example, 30 mass% or less, preferably 20 mass% or less, more preferably 10 mass% or less, even more preferably 5.0 mass% or less, and particularly preferably 2.0 mass% or less, relative to the total amount of the composition.

[0149] That is, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the content of the second compound is, for example, 0.1 to 30 mass%, preferably 0.3 to 20 mass%, more preferably 0.5 to 10 mass%, even more preferably 0.7 to 5.0 mass%, and particularly preferably 1.0 to 2.0 mass%, relative to the total amount of the composition.

[0150] When the composition contains other compounds (compounds other than the first compound and the second compound), the peaks corresponding to the other compounds have peak tops at retention times corresponding to the molecular weights of the other compounds in a chromatogram (high-performance liquid chromatogram) obtained by high-performance liquid chromatographic measurement at a detection wavelength of 254 nm.

[0151] When the composition contains a plurality of other compounds (compounds other than the first compound and the second compound), the above-mentioned high performance liquid chromatogram has a plurality of peaks corresponding to the other compounds depending on the types of the other compounds.

[0152] The area ratio of the peak corresponding to the other compound (when there are multiple peaks corresponding to the other compounds, the sum of the area ratios of the peaks (the same applies below)) is, for example, the remainder between the area ratio of the peak corresponding to the first compound and the area ratio of the peak corresponding to the second compound.

[0153] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the lower limit of the area ratio (total amount) of peaks corresponding to other compounds in the above-mentioned high performance liquid chromatogram is, for example, 0.5% or more, preferably 1.0% or more, more preferably 5.0% or more, even more preferably 10% or more, and particularly preferably 20% or more, relative to the area of ​​all peaks.

[0154] Furthermore, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the upper limit of the area ratio of peaks corresponding to other compounds in the above-mentioned high performance liquid chromatogram is, for example, 80% or less, preferably 60% or less, more preferably 55% or less, even more preferably 50% or less, and particularly preferably 40% or less, relative to the area of ​​all peaks.

[0155] That is, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the area ratio of peaks corresponding to other compounds in the above-mentioned high performance liquid chromatogram is, for example, 0.5 to 80%, preferably 1.0 to 60%, more preferably 5.0 to 55%, even more preferably 10 to 50%, and still more preferably, particularly preferably 20 to 40%.

[0156] Furthermore, the area proportion of the peaks corresponding to the other compounds in the high performance liquid chromatogram of the composition corresponds to the mass proportion of the other compounds in the composition.

[0157] From the viewpoints of refractive index, flexibility, transparency, and weather resistance, the lower limit of the content of other compounds is, for example, 0.5 mass% or more, preferably 1.0 mass% or more, more preferably 5.0 mass% or more, even more preferably 10 mass% or more, and particularly preferably 20 mass% or more, relative to the total amount of the composition.

[0158] Furthermore, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the upper limit of the content of other compounds is, for example, 80 mass % or less, preferably 60 mass % or less, more preferably 55 mass % or less, even more preferably 50 mass % or less, and particularly preferably 40 mass % or less, relative to the total amount of the composition.

[0159] That is, from the viewpoints of refractive index, flexibility, transparency, and weather resistance, the content of the other compounds is, for example, 0.5 to 80 mass%, preferably 1.0 to 60 mass%, more preferably 5.0 to 55 mass%, even more preferably 10 to 50 mass%, and particularly preferably 20 to 40 mass%, relative to the total amount of the composition.

[0160] (3) Effects and Effects The composition is a novel composition. Examples of uses of the composition include additives. That is, additives preferably contain the composition. More specifically, the composition is an additive (additive composition) to be added to a curable compound described below.

[0161] More specifically, the additives include plasticizers and refractive index adjusters, and preferably plasticizers. That is, the plasticizer preferably contains the composition. In other words, the composition is preferably used as a plasticizer.

[0162] The composition described above can provide a cured product (described below) that has excellent refractive index, flexibility, transparency, and weather resistance.

[0163] 2. Curable Composition (1) Main Component The curable composition contains a plasticizer and a curable compound as main components. The main component is a component whose content relative to the total is equal to or greater than a predetermined value. The content ratio of the main component relative to the total is, for example, 90% by mass or more. In other words, the total solid content of the plasticizer and the curable compound is 90% by mass or more relative to the total solid content of the curable composition.

[0164] The curable compound is an uncured compound that is cured by a known method to produce a cured resin (described below). The plasticizer is an additive that improves the flexibility of the cured resin (described below). The plasticizer and the curable compound are described in detail below.

[0165] (2) Plasticizer The plasticizer contains the above-mentioned composition (i.e., a composition containing the first compound and the second compound). The plasticizer is preferably composed of the above-mentioned composition (i.e., a composition containing the first compound and the second compound). If the plasticizer contains the above-mentioned composition, the flexibility, transparency, and weather resistance of the cured product (described below) can be improved. Furthermore, if the plasticizer contains the above-mentioned composition, a decrease in the refractive index of the cured product (described below) can be suppressed, or the refractive index can be improved.

[0166] (3) Curable Compound The curable compound is not particularly limited, and examples thereof include resin raw materials capable of producing a cured resin (described below).

[0167] As described below, examples of the cured resin include cured polyurethane resin, cured polyolefin resin, cured polyamine resin, cured amide resin, cured urea resin, cured phenolic resin, cured epoxy resin, cured acrylic resin, cured melamine resin, and cured alkyd resin. These may be used alone or in combination of two or more.

[0168] As the curable resin (described later), preferably, a curable polyurethane resin or a curable acrylic resin is used, and the curable compound is selected depending on the type of the curable resin (described later).

[0169] For example, when a cured polyurethane resin is used as the curable resin, the curable compound may be, for example, a polyurethane resin raw material, or when a cured acrylic resin is used as the curable resin, the curable compound may be, for example, an acrylic resin raw material.

[0170] The polyurethane resin raw material and the acrylic resin raw material will be described in detail below.

[0171] (3-1) Polyurethane Resin Raw Material The polyurethane resin raw material is an uncured (unreacted) resin composition for producing a cured polyurethane resin (described later). The polyurethane resin raw material includes, for example, a polyisocyanate and a polyol.

[0172] (3-2) Polyisocyanate Polyisocyanate has multiple isocyanate groups in one molecule. Examples of polyisocyanate include polyisocyanate monomers and polyisocyanate derivatives.

[0173] Examples of polyisocyanate monomers include aliphatic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

[0174] Examples of aliphatic polyisocyanates include ethylene diisocyanate, trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caproate. These can be used alone or in combination of two or more.

[0175] The aliphatic polyisocyanate monomer also includes an alicyclic polyisocyanate monomer. Examples of the alicyclic polyisocyanate monomer include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, methylenebis(cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, norbornane diisocyanate, and bis(isocyanatomethyl)cyclohexane. These can be used alone or in combination of two or more types.

[0176] Examples of aromatic polyisocyanates include tolylene diisocyanate, phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, and 4,4'-diphenyl ether diisocyanate. These can be used alone or in combination of two or more.

[0177] Examples of aromatic aliphatic polyisocyanates include xylylene diisocyanate, tetramethylxylylene diisocyanate, and ω,ω'-diisocyanate-1,4-diethylbenzene. These can be used alone or in combination of two or more.

[0178] The polyisocyanate derivative is derived from the polyisocyanate monomer described above. Examples of the polyisocyanate derivative include isocyanurate-modified products, iminooxadiazinedione-modified products, triol adducts, allophanate-modified products, biuret-modified products, urea-modified products, oxadiazinetrione-modified products, carbodiimide-modified products, uretdione-modified products, and uretonimine-modified products. These can be used alone or in combination of two or more types. A preferred example of the polyisocyanate derivative is an isocyanurate-modified product.

[0179] The polyisocyanate may be used alone or in combination of two or more kinds. The polyisocyanate preferably contains a polyisocyanate derivative, and more preferably consists of a polyisocyanate derivative.

[0180] As the polyisocyanate derivative, from the viewpoint of improving the refractive index, transparency, and weather resistance, a polyisocyanate derivative derived from an araliphatic polyisocyanate (araliphatic polyisocyanate derivative) is preferably used.

[0181] As the aromatic aliphatic polyisocyanate derivative, a derivative of xylylene diisocyanate is more preferred, and a triol adduct of xylylene diisocyanate is even more preferred.

[0182] The polyisocyanate has an average number of isocyanate groups of, for example, 2 or more, or preferably 2.5 or more. The polyisocyanate has an average number of isocyanate groups of, for example, 4 or less, or preferably 3.5 or less.

[0183] The polyisocyanate has an isocyanate group content (NCO%) of, for example, 5% by mass or more, or preferably 7% by mass or more, and for example, 30% by mass or less, or preferably 25% by mass or less.

[0184] (3-3) Polyols Polyols include, for example, macropolyols. Macropolyols have two or more hydroxyl groups per molecule. Macropolyols are relatively high molecular weight organic compounds. The number average molecular weight of macropolyols is, for example, 400 or more and, for example, 20,000 or less. The number average molecular weight can be calculated by a known method from the hydroxyl group equivalent weight and the average number of hydroxyl groups. The number average molecular weight can also be measured as a polystyrene-equivalent molecular weight by gel permeation chromatography (the same applies below).

[0185] Examples of macropolyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These macropolyols can be used alone or in combination of two or more.

[0186] The number average molecular weight of the macropolyol is, for example, more than 400, preferably 500 or more, more preferably 1000 or more. The number average molecular weight of the macropolyol is, for example, 20,000 or less, preferably 15,000 or less, more preferably 10,000 or less, and even more preferably 5,000 or less.

[0187] The hydroxyl value of the macropolyol is, for example, 5 mg KOH / g or more, preferably 10 mg KOH / g or more, more preferably 15 mg KOH / g or more, and even more preferably 20 mg KOH / g or more. The hydroxyl value of the macropolyol is, for example, 500 mg KOH / g or less, preferably 300 mg KOH / g or less, more preferably 200 mg KOH / g or less, even more preferably 100 mg KOH / g or less, and particularly preferably 50 mg KOH / g or less. The hydroxyl value is measured in accordance with the description of JIS K 1557-1 (2007) (hereinafter the same).

[0188] As the macropolyol, preferably, an acrylic polyol is used.

[0189] The acrylic polyol may be, for example, a copolymer of an acrylic raw material component, which may contain, for example, a hydroxyl group-containing (meth)acrylate and a copolymerizable vinyl monomer.

[0190] The term "(meth)acrylate" refers to an acrylate and / or a methacrylate, and the term "copolymerizable vinyl monomer" refers to a vinyl monomer that can be polymerized with the hydroxyl group-containing (meth)acrylate.

[0191] The hydroxyl group-containing (meth)acrylate contains a hydroxyl group and an alkyl group. Examples of the alkyl group include alkyl groups having 1 to 4 carbon atoms. Specific examples of the hydroxyalkyl (meth)acrylate include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and 2,2-dihydroxymethylbutyl (meth)acrylate. These may be used alone or in combination of two or more. Preferred examples of the hydroxyl group-containing (meth)acrylate include hydroxyalkyl (meth)acrylate, more preferably 2-hydroxyethyl (meth)acrylate, and even more preferably 2-hydroxyethyl methacrylate.

[0192] Examples of copolymerizable vinyl monomers include alkyl(meth)acrylates. Alkyl(meth)acrylates do not contain hydroxyl groups but contain an alkyl group. Examples of alkyl groups include alkyl groups having 1 to 4 carbon atoms and alkyl groups having 5 to 8 carbon atoms. Examples of alkyl(meth)acrylates having an alkyl group having 1 to 4 carbon atoms include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate, butyl(meth)acrylate, isobutyl(meth)acrylate, s-butyl(meth)acrylate, and t-butyl(meth)acrylate. Examples of alkyl(meth)acrylates having an alkyl group having 5 to 8 carbon atoms include pentyl(meth)acrylate, isopentyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and cyclohexyl(meth)acrylate. These can be used alone or in combination of two or more.

[0193] Furthermore, examples of copolymerizable vinyl monomers include aromatic ring-containing vinyl monomers. Examples of aromatic ring-containing vinyl monomers include aromatic ring-containing (meth)acrylates. Aromatic ring-containing (meth)acrylates contain an aromatic ring. Examples of aromatic rings include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. More specific examples of aromatic ring-containing (meth)acrylates include benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, and 1-naphthylmethyl (meth)acrylate. These can be used alone or in combination of two or more. Preferred examples of aromatic ring-containing (meth)acrylates include m-phenoxybenzyl (meth)acrylate and naphthylmethyl (meth)acrylate, and more preferred examples include m-phenoxybenzyl acrylate and naphthylmethyl acrylate. In addition to the above, examples of aromatic ring-containing vinyl monomers include styrene, α-methylstyrene, vinyltoluene, vinylbiphenyl, and divinylbenzene. These can be used alone or in combination of two or more. Preferred examples of aromatic ring-containing vinyl monomers include aromatic ring-containing (meth)acrylates.

[0194] Furthermore, examples of copolymerizable vinyl monomers include vinyl monomers containing functional groups (excluding hydroxyl groups). Examples of vinyl monomers containing functional groups (excluding hydroxyl groups) include carboxyl group-containing vinyl monomers, glycidyl group-containing vinyl monomers, amino group-containing vinyl monomers, cyano group-containing vinyl monomers, acetoacetoxy group-containing vinyl monomers, sulfonic acid group-containing vinyl monomers, and phosphate group-containing vinyl monomers. Examples of carboxyl group-containing vinyl monomers include acrylic acid. Examples of glycidyl group-containing vinyl monomers include glycidyl (meth)acrylate. Examples of amino group-containing vinyl monomers include 2-aminoethyl (meth)acrylate. Examples of cyano group-containing vinyl monomers include (meth)acrylonitrile. Examples of acetoacetoxy group-containing vinyl monomers include acetoacetoxyethyl (meth)acrylate. Examples of sulfonic acid group-containing vinyl monomers include allyl sulfonic acid and its salts. Examples of phosphate group-containing vinyl monomers include 2-methacryloyloxyethyl acid phosphate. These may be used alone or in combination of two or more. As the vinyl monomer containing a functional group (excluding a hydroxyl group), preferably, a vinyl monomer containing a carboxyl group is used, and more preferably, acrylic acid is used.

[0195] Examples of copolymerizable vinyl monomers include alicyclic group-containing vinyl monomers and (meth)acryloyl group-containing rubbers. Examples of alicyclic group-containing vinyl monomers include dicyclopentenyloxyethyl (meth)acrylate. Examples of (meth)acryloyl group-containing rubbers include (meth)acryloyl group-containing isoprene rubber. Furthermore, examples of copolymerizable vinyl monomers include, in addition to the above, vinyl esters, N-substituted unsaturated carboxylic acid amides, heterocyclic vinyl compounds, vinylidene halides, α-olefins, dienes, and crosslinkable vinyl monomers. Examples of crosslinkable vinyl monomers include polyfunctional (meth)acrylates, more specifically, bifunctional (meth)acrylates, trifunctional (meth)acrylates, and tetrafunctional or higher (meth)acrylates. Examples of bifunctional (meth)acrylates include ethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, and oligoethylene glycol di(meth)acrylate. Examples of trifunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate. Examples of tetrafunctional or higher functional (meth)acrylates include pentaerythritol tetra(meth)acrylate. These may be used alone or in combination of two or more.

[0196] These copolymerizable vinyl monomers may be used alone or in combination of two or more.

[0197] The copolymerizable vinyl monomer is preferably an aromatic ring-containing vinyl monomer. If the copolymerizable vinyl monomer contains an aromatic ring-containing vinyl monomer, the acrylic polyol contains an aromatic ring. In other words, the acrylic polyol is preferably an aromatic ring-containing acrylic polyol. The aromatic ring-containing acrylic polyol can provide a cured product (described later) having an excellent refractive index, excellent flexibility, excellent transparency, and excellent weather resistance.

[0198] Furthermore, as the copolymerizable vinyl monomer, a carboxy group-containing vinyl monomer is preferably used. If the acrylic polyol contains a carboxy group-containing vinyl monomer, the acrylic polyol contains a carboxy group. In other words, the acrylic polyol is preferably a carboxy group-containing acrylic polyol. The carboxy group-containing acrylic polyol can provide a cured product (described later) having an excellent refractive index, excellent flexibility, excellent transparency, and excellent weather resistance.

[0199] The blending ratio of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer is appropriately set depending on the purpose and application. For example, the hydroxyl group-containing (meth)acrylate is, for example, 1 part by mass or more, preferably 3 parts by mass or more, per 100 parts by mass of the total of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer. Furthermore, the hydroxyl group-containing (meth)acrylate is, for example, 30 parts by mass or less, preferably 10 parts by mass or less, per 100 parts by mass of the total of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer.

[0200] The total amount of the copolymerizable vinyl monomer is, for example, 70 parts by mass or more, preferably 90 parts by mass or more, relative to 100 parts by mass of the total amount of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer. The total amount of the copolymerizable vinyl monomer is, for example, 99 parts by mass or less, preferably 97 parts by mass or less, relative to 100 parts by mass of the total amount of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer.

[0201] More specifically, when an aromatic ring-containing vinyl monomer is used, the amount of the aromatic ring-containing vinyl monomer is, for example, 70 parts by mass or more, preferably 90 parts by mass or more, per 100 parts by mass of the total amount of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer, and the amount of the aromatic ring-containing vinyl monomer is, for example, 99 parts by mass or less, preferably 97 parts by mass or less, per 100 parts by mass of the total amount of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer.

[0202] When a carboxyl group-containing vinyl monomer is used, the content of the carboxyl group-containing vinyl monomer is appropriately set so that the total of the acid value and hydroxyl value of the acrylic polyol (carboxyl group-containing acrylic polyol) falls within the range described below.

[0203] For example, the amount of the carboxyl group-containing vinyl monomer is, for example, 1 part by mass or more, preferably 5 parts by mass or more, per 100 parts by mass of the total amount of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer, and the amount of the carboxyl group-containing vinyl monomer is, for example, 99 parts by mass or less, preferably 97 parts by mass or less, per 100 parts by mass of the total amount of the hydroxyl group-containing (meth)acrylate and the copolymerizable vinyl monomer.

[0204] The method for producing the acrylic polyol is not particularly limited. For example, the above-mentioned acrylic raw material components are copolymerized in the presence of a known organic solvent. Examples of the organic solvent include toluene. The blending ratio and blending timing of the organic solvent are appropriately set depending on the purpose and application.

[0205] In the production of acrylic polyol, a known polymerization initiator is used as necessary. Examples of the polymerization initiator include known radical polymerization initiators (described below), more preferably azo compounds (described below) and peroxides (described below), even more preferably peroxides (described below), and particularly preferably t-butylperoxy-2-ethylhexanoate. The blending ratio and blending timing of the polymerization initiator are appropriately set depending on the purpose and application.

[0206] The polymerization conditions for the acrylic raw material components are appropriately set depending on the purpose and application. For example, the polymerization temperature is, for example, 50°C or higher, preferably 70°C or higher. The polymerization temperature is, for example, 150°C or lower, preferably 130°C or lower. The polymerization time is, for example, 30 minutes or longer, preferably 1 hour or longer. The polymerization time is, for example, 12 hours or shorter, preferably 6 hours or shorter.

[0207] For example, when an organic solvent is used in the above polymerization method, a solution and / or dispersion of the acrylic polyol is obtained as the reaction product liquid.

[0208] The solids concentration of the acrylic polyol solution and / or dispersion can be adjusted by a known method. For example, an organic solvent can be added to the reaction product liquid as needed. Alternatively, a portion of the organic solvent can be removed from the reaction product liquid.

[0209] The solids concentration of the acrylic polyol solution and / or dispersion is, for example, 30% by mass or more, preferably 40% by mass or more, and for example, 60% by mass or less, preferably 50% by mass or less.

[0210] The number average molecular weight of the acrylic polyol is, for example, more than 400, preferably 500 or more, and more preferably 1000 or more. The number average molecular weight of the acrylic polyol is, for example, 20000 or less, preferably 15000 or less, more preferably 10000 or less, and even more preferably 5000 or less.

[0211] The hydroxyl value of the acrylic polyol is, for example, 1 mgKOH / g or more, preferably 3 mgKOH / g or more. The hydroxyl value of the acrylic polyol is, for example, 500 mgKOH / g or less, preferably 300 mgKOH / g or less. The hydroxyl value is measured in accordance with the description of JIS K 1557-1 (2007) (the same applies hereinafter).

[0212] When the acrylic polyol does not contain a carboxyl group-containing acrylic polyol, the hydroxyl value of the acrylic polyol is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and particularly preferably 20 mgKOH / g or more. The hydroxyl value of the acrylic polyol is preferably 200 mgKOH / g or less, more preferably 100 mgKOH / g or less, and particularly preferably 50 mgKOH / g or less.

[0213] Furthermore, when the acrylic polyol contains a carboxy group-containing acrylic polyol, the total acid value and hydroxyl value of the acrylic polyol (carboxy group-containing acrylic polyol) is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more. Furthermore, the total acid value and hydroxyl value of the acrylic polyol (carboxy group-containing acrylic polyol) is preferably 20 mgKOH / g or less, more preferably 10 mgKOH / g or less. The total acid value and hydroxyl value are measured in accordance with the description of JIS K 1557-5 (2007) (the same applies hereinafter).

[0214] When the acrylic polyol contains a carboxyl group-containing acrylic polyol, the acid value of the acrylic polyol (carboxyl group-containing acrylic polyol) is, for example, 1 mgKOH / g or more, preferably 3 mgKOH / g or more. The acid value of the acrylic polyol (carboxyl group-containing acrylic polyol) is, for example, 20 mgKOH / g or less, preferably 10 mgKOH / g or less. The acid value is measured in accordance with the description of JIS K 1557-5 (2007) (the same applies hereinafter).

[0215] The polyol may include a low molecular weight polyol in addition to the macropolyol. The low molecular weight polyol has two or more hydroxyl groups in one molecule. The low molecular weight polyol is a relatively low molecular weight organic compound. The molecular weight of the low molecular weight polyol is, for example, 40 or more, for example, 400 or less.

[0216] Examples of low-molecular-weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. Examples of low-molecular-weight polyols include polymers obtained by addition polymerization of alkylene (C2-C3) oxides with dihydric to tetrahydric alcohols to obtain a number-average molecular weight of less than 400. These can be used alone or in combination of two or more types. Examples of low-molecular-weight polyols include preferably dihydric alcohols and trihydric alcohols, and more preferably dihydric alcohols.

[0217] The polyols can be used alone or in combination of two or more. As the polyol, preferably, a macropolyol is used alone, and more preferably, an acrylic polyol is used alone.

[0218] (3-4) Form of polyurethane resin raw material Examples of the form of polyurethane resin raw material include one-component curing polyurethane resin and two-component curing polyurethane resin. A preferred form of polyurethane resin raw material is two-component curing polyurethane resin. A two-component curing polyurethane resin comprises an independent curing agent and a base agent.

[0219] In the two-component curing polyurethane resin, the curing agent includes, for example, the above-mentioned polyisocyanate. In the two-component curing polyurethane resin, the base agent includes, for example, the above-mentioned polyol. The curing agent and base agent are blended at the time of use to form a urethane cured product (cured resin described below). In the base agent, the polyol may be diluted with a known organic solvent. In the curing agent, the polyisocyanate may be diluted with a known organic solvent.

[0220] The two-component curing polyurethane resin preferably contains a base resin containing the above-mentioned acrylic polyol and a curing agent containing the above-mentioned polyisocyanate, thereby producing a cured product (described below) that has an excellent refractive index, flexibility, transparency, and weather resistance.

[0221] The polyisocyanate and polyol undergo a urethane reaction by a known method to produce a cured polyurethane resin. In the urethane reaction, the blending ratio of the polyisocyanate and the polyol is adjusted, for example, based on the equivalent ratio (OH / NCO) of the hydroxyl groups in the polyol to the isocyanate groups in the polyisocyanate. The equivalent ratio (OH / NCO) of the hydroxyl groups in the polyol to the isocyanate groups in the polyisocyanate is, for example, 0.5 or more, preferably 0.8 or more, and more preferably 0.95 or more. Furthermore, the equivalent ratio (OH / NCO) of the hydroxyl groups in the polyol to the isocyanate groups in the polyisocyanate is, for example, 2.0 or less, preferably 1.5 or less, and more preferably 1.1 or less.

[0222] When the polyol contains the carboxyl group-containing acrylic polyol, the blending ratio of the polyisocyanate and the polyol is adjusted, for example, based on the equivalent ratio (OH+COOH / NCO) of the total amount of hydroxyl groups and carboxyl groups in the polyol to the isocyanate groups in the polyisocyanate. The equivalent ratio (OH+COOH / NCO) of the total amount of hydroxyl groups and carboxyl groups in the polyol to the isocyanate groups in the polyisocyanate is, for example, 0.5 or more, preferably 0.8 or more, and more preferably 0.95 or more. The equivalent ratio (OH+COOH / NCO) of the total amount of hydroxyl groups and carboxyl groups in the polyol to the isocyanate groups in the polyisocyanate is, for example, 2.0 or less, preferably 1.5 or less, and more preferably 1.1 or less.

[0223] (3-5) Acrylic Resin Raw Material The acrylic resin raw material is a curable compound for producing a cured acrylic resin (described later). The acrylic resin raw material contains, for example, a monomer component and a polymerization initiator.

[0224] (3-6) Monomer Component The monomer component contains, for example, a radically polymerizable monomer. The radically polymerizable monomer is a monomer that can generate a cured acrylic resin by radical polymerization.

[0225] Examples of radical polymerizable monomers include the monomers described above as raw materials for acrylic polyols. More specifically, examples of radical polymerizable monomers include the alkyl (meth)acrylates, hydroxyl group-containing (meth)acrylates, aromatic ring-containing vinyl monomers, carboxy group-containing vinyl monomers, glycidyl group-containing vinyl monomers, amino group-containing vinyl monomers, cyano group-containing vinyl monomers, acetoacetoxy group-containing vinyl monomers, sulfonic acid group-containing vinyl monomers, phosphoric acid group-containing vinyl monomers, alicyclic group-containing vinyl monomers, (meth)acryloyl group-containing rubbers, vinyl esters, N-substituted unsaturated carboxylic acid amides, heterocyclic vinyl compounds, vinylidene halide compounds, α-olefins, dienes, and crosslinkable vinyl monomers. These can be used alone or in combination of two or more.

[0226] As the radical polymerizable monomer, preferably, an alicyclic group-containing vinyl monomer and a (meth)acryloyl group-containing rubber are used, and more preferably, dicyclopentenyloxyethyl (meth)acrylate and a (meth)acryloyl group-containing isoprene rubber are used.

[0227] (3-7) Polymerization Initiator Examples of the polymerization initiator include known radical polymerization initiators, such as active energy ray radical polymerization initiators and thermal radical polymerization initiators.

[0228] Examples of active energy ray radical polymerization initiators include photoradical polymerization initiators. Examples of photoradical polymerization initiators include alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators, carbazolephenone-based photopolymerization initiators, acridine-based photopolymerization initiators, triazine-based photopolymerization initiators, and benzoyl-based photopolymerization initiators. These can be used alone or in combination of two or more.

[0229] Examples of thermal radical polymerization initiators include azo compounds and peroxides. Examples of azo compounds include azoisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl azoisobutyrate. Examples of peroxides include benzoyl peroxide, ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxyester, t-butylperoxy-2-ethylhexanoate, and peroxydicarbonate. These can be used alone or in combination of two or more.

[0230] The active energy ray radical polymerization initiator may also function as a thermal radical polymerization initiator, and the thermal radical polymerization initiator may also function as an active energy ray radical polymerization initiator.

[0231] The radical polymerization initiator may be commercially available. Examples of commercially available radical polymerization initiators include the Azo Polymerization Initiator V series manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., the Omnirad series manufactured by IGM Resins B.V., and the Percure series manufactured by NOF Corporation. These may be used alone or in combination of two or more types.

[0232] The polymerization initiator is preferably an active energy ray radical polymerization initiator, more preferably a photopolymerization initiator. The blending ratio and blending timing of the polymerization initiator are appropriately set depending on the purpose and application.

[0233] (3-8) Formulation of Acrylic Resin Raw Material The acrylic resin raw material may be, for example, a mixture containing the radical polymerizable monomer and the polymerization initiator. The acrylic resin raw material may also contain a known organic solvent. Preferably, the acrylic resin raw material does not contain an organic solvent and is composed of the radical polymerizable monomer and the polymerization initiator.

[0234] (4) Form of Curable Composition The curable composition contains, for example, a plasticizer and a curable compound as described above. Preferably, the curable composition contains a plasticizer and a polyurethane resin raw material and / or an acrylic resin raw material as the curable compound. More preferably, the curable composition contains a plasticizer and a polyurethane resin raw material, or a plasticizer and an acrylic resin raw material.

[0235] The blending ratio of the plasticizer and the curable compound is not particularly limited and is appropriately set depending on the purpose and application. For example, the plasticizer is, for example, 1 part by mass (phr) or more, preferably 5 parts by mass (phr) or more, per 100 parts by mass of the solid content of the curable compound. Furthermore, the plasticizer is, for example, 70 parts by mass (phr) or less, preferably 50 parts by mass (phr) or less, per 100 parts by mass of the solid content of the curable compound.

[0236] The content of the plasticizer is, for example, 1% by mass or more, preferably 3% by mass or more, based on the total amount (solid content) of the plasticizer and the curable compound, and is, for example, 50% by mass or less, preferably 35% by mass or less, based on the total amount (solid content) of the plasticizer and the curable compound.

[0237] The content of the curable compound is, for example, 50% by mass or more, preferably 65% ​​by mass or more, based on the total amount (solid content) of the plasticizer and the curable compound, and is, for example, 99% by mass or less, preferably 97% by mass or less, based on the total amount (solid content) of the plasticizer and the curable compound.

[0238] The form in which the plasticizer is contained is not particularly limited. For example, when the curable compound is a two-component curing polyurethane resin, the plasticizer may be added to the curing agent (polyisocyanate) of the two-component curing polyurethane resin. Alternatively, the plasticizer may be added to the base agent (polyol) of the two-component curing polyurethane resin. Alternatively, the plasticizer may be added to both the base agent and the curing agent of the two-component curing polyurethane resin.

[0239] The plasticizer may be prepared separately from the base component and curing agent of the two-component curing polyurethane resin. When the plasticizer is prepared separately, the plasticizer may be added simultaneously with the base component and curing agent when they are mixed, or may be added to the mixture after the base component and curing agent are mixed.

[0240] Furthermore, for example, when the curable compound is an acrylic resin raw material, the plasticizer may be mixed in advance with the radical polymerizable monomer. Alternatively, the plasticizer may be mixed in advance with the polymerization initiator. Alternatively, the plasticizer may be added simultaneously with the mixing of the radical polymerizable monomer and the polymerization initiator, or may be added to the mixture after the mixing of the radical polymerizable monomer and the polymerization initiator.

[0241] (5) Subcomponent The curable composition may contain additives as subcomponents, if necessary. The subcomponent is a component whose content relative to the total content is a predetermined value or less. The content ratio of the subcomponent relative to the total content is, for example, 10% by mass or less. In other words, the proportion of the additive is 10% by mass or less relative to the total solid content of the curable composition.

[0242] Examples of additives include ultraviolet absorbers (UV absorbers), light stabilizers (light stabilizers), and antioxidants.Further examples of additives include heat stabilizers, crosslinking agents, silane coupling agents, antifoaming agents, leveling agents, mildew inhibitors, rust inhibitors, matting agents, flame retardants, thixotropic agents, tackifiers, thickeners, lubricants, antistatic agents, surfactants, reaction retarders, hydrolysis inhibitors, dyes, inorganic pigments, organic pigments, anti-tack agents, inorganic fillers, and organic fillers.These may be used alone or in combination of two or more.The amount and timing of addition of the additives are appropriately determined depending on the purpose and application.

[0243] From the viewpoint of the weather resistance of the cured product (described later), preferred additives include an ultraviolet absorber (UV absorber), a light stabilizer (light stabilizer), and an antioxidant. That is, the curable composition preferably contains at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and an antioxidant. From the viewpoint of the weather resistance of the cured product (described later), the ratio of the additive (at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and an antioxidant) is, for example, 1 × 10 with respect to 1 part by mass of the above-described curable composition (total amount). －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６ From the viewpoint of cost reduction, the proportion of the additive (at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and an antioxidant) is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the above-mentioned curable composition (total amount). －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0244] The ultraviolet absorber is not particularly limited, and examples thereof include known ultraviolet absorbers (for example, those described in the ADEKA catalog and the CLARIANT catalog). More specific examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzylidene-based ultraviolet absorbers, and triazine-based ultraviolet absorbers. These are used alone or in combination of two or more. From the viewpoint of weather resistance of the cured product (described later), a preferred ultraviolet absorber is a benzotriazole-based ultraviolet absorber. The blending ratio of the ultraviolet absorber is, for example, 1 x 10 relative to 1 part by mass of the above-mentioned curable composition. －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６From the viewpoint of cost reduction, the blending ratio of the ultraviolet absorber is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the curable composition. －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0245] The light resistance stabilizer is not particularly limited, and examples thereof include known light resistance stabilizers (for example, those described in the ADEKA catalog). More specific examples of the light resistance stabilizer include hindered amine (HALS) light resistance stabilizers and benzoate light resistance stabilizers. These are used alone or in combination of two or more. From the viewpoint of the weather resistance of the cured product (described later), the light resistance stabilizer is preferably a hindered amine (HALS) light resistance stabilizer. The blending ratio of the light resistance stabilizer relative to 1 part by mass of the above-mentioned curable composition is, for example, 1 x 10 －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６ From the viewpoint of cost reduction, the blending ratio of the light resistance stabilizer is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the curable composition. －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0246] The antioxidant is not particularly limited, and examples thereof include known antioxidants (for example, those listed in the ADEKA catalog). More specific examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, and thiophene-based antioxidants. These are used alone or in combination of two or more. From the viewpoint of weather resistance of the cured product (described later), a phenol-based antioxidant is preferably used as the antioxidant. The blending ratio of the antioxidant is, for example, 1 x 10 relative to 1 part by mass of the above-mentioned curable composition. －６ Parts by mass (ppm) or more, preferably 10 x 10－６ Parts by mass (ppm) or more, more preferably 100 x 10 －６ From the viewpoint of cost efficiency, the blending ratio of the antioxidant is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the curable composition. －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0247] (6) Uses The curable composition described above is suitably used in various industrial fields. Examples of uses of the curable composition include coating agents, paints, and adhesives. A preferred use of the curable composition is as an adhesive.

[0248] The adhesive is an uncured curable composition that, when cured, forms a cured adhesive product (described later). The cured adhesive product bonds adherends.

[0249] The curable composition can provide a cured product having an excellent refractive index, flexibility, transparency, and weather resistance. Therefore, the curable composition is suitable for use as an optical curable composition. Examples of applications of the optical curable composition include optical coating agents, optical paints, and optical adhesives.

[0250] 3. Cured Product (1) Main Component The cured product contains the above-mentioned plasticizer and cured resin as main components. The main component is a component whose content relative to the total is equal to or greater than a predetermined value. The content ratio of the main component relative to the total is, for example, 90% by mass or more. In other words, the total solid content of the plasticizer and cured resin is 90% by mass or more relative to the total solid content of the cured product.

[0251] The cured product is formed by curing the curable composition by a known method. The method for curing the curable composition is appropriately selected depending on the type of curable compound.

[0252] (2) Cured Resin The cured resin contains, for example, a cured product of the above-described curable compound, and preferably consists of a cured product of the above-described curable compound.

[0253] More specifically, examples of the cured resin include cured polyurethane resin, cured polyolefin resin, cured polyamine resin, cured amide resin, cured urea resin, cured phenolic resin, cured epoxy resin, cured acrylic resin, cured melamine resin, and cured alkyd resin. These may be used alone or in combination of two or more.

[0254] As the cured resin, preferably, a cured polyurethane resin and a cured acrylic resin are used, and more preferably, a cured acrylic resin is used.

[0255] Examples of cured polyurethane resins include cured products of the polyurethane resin raw materials described above. More specifically, cured polyurethane resins include reaction products of the base agent containing the polyol described above and the curing agent containing the polyisocyanate described above. Such cured resins can produce cured products that have a better refractive index, better flexibility, better transparency, and better weather resistance. More specifically, if the cured resin contains a cured polyurethane resin (a reaction product of the base agent containing the acrylic polyol described above and the curing agent containing the polyisocyanate described above), a cured product that satisfies the physical properties (refractive index and flexibility) described below can be more easily obtained.

[0256] Examples of cured acrylic resins include cured products of the above-mentioned acrylic resin raw materials. More specifically, examples of cured acrylic resins include reaction products obtained by radical polymerization of the above-mentioned radically polymerizable monomers. The method for obtaining the cured acrylic resin is not particularly limited. For example, when an active energy ray radical polymerization initiator is used, the acrylic resin raw material is irradiated with active energy rays having a predetermined wavelength. Furthermore, when a thermal radical polymerization initiator is used, the acrylic resin raw material is heated to a predetermined temperature. This activates the polymerization initiator, causing the radically polymerizable monomers to undergo a radical polymerization reaction, resulting in the cured acrylic resin. In particular, when the cured resin contains a cured acrylic resin (a radical polymerization product of the above-mentioned monomer components), a cured product having excellent flexibility and a particularly excellent refractive index can be obtained.

[0257] (3) Subcomponents The cured product may contain the above-mentioned additives (excluding plasticizers) as subcomponents, if necessary. Subcomponents are components whose content relative to the total content is equal to or less than a predetermined value. The content ratio of the subcomponents relative to the total content is, for example, 10% by mass or less. In other words, the proportion of the additives relative to the total solid content of the cured product is 10% by mass or less.

[0258] From the viewpoint of weather resistance of the cured product, preferred additives include an ultraviolet absorber (UV absorber), a light stabilizer (light stabilizer), and an antioxidant. That is, the cured product preferably contains at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and an antioxidant. From the viewpoint of weather resistance of the cured product, the proportion of the additive (at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and an antioxidant) is, for example, 1 × 10 per part by mass of the above-mentioned cured product (total amount). －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６ From the viewpoint of cost efficiency, the proportion of the additive (at least one additive selected from the group consisting of an ultraviolet absorber, a light stabilizer, and an antioxidant) is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the above-mentioned cured product (total amount).－６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0259] The ultraviolet absorber is not particularly limited, and examples thereof include known ultraviolet absorbers (for example, those listed in the ADEKA catalog). More specific examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzylidene-based ultraviolet absorbers, and triazine-based ultraviolet absorbers. These are used alone or in combination of two or more. From the viewpoint of weather resistance of the cured product, the ultraviolet absorber is preferably a benzotriazole-based ultraviolet absorber. The blending ratio of the ultraviolet absorber is, for example, 1 x 10 per part by mass of the above-mentioned cured product. －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６ From the viewpoint of cost reduction, the blending ratio of the ultraviolet absorber is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the cured product. －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0260] The light resistance stabilizer (light stabilizer) is not particularly limited, and examples thereof include known light resistance stabilizers (for example, those described in the ADEKA catalog). More specific examples of light resistance stabilizers include hindered amine (HALS) light resistance stabilizers and benzoate light resistance stabilizers. These are used alone or in combination of two or more. From the viewpoint of weather resistance of the cured product, the light resistance stabilizer is preferably a hindered amine (HALS) light resistance stabilizer. The blending ratio of the light resistance stabilizer relative to 1 part by mass of the above-mentioned cured product is, for example, 1 x 10 －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６From the viewpoint of cost reduction, the blending ratio of the light resistance stabilizer is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the cured product. －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0261] The antioxidant is not particularly limited, and examples thereof include known antioxidants (for example, those listed in the ADEKA catalog). More specific examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, and thiophene-based antioxidants. These are used alone or in combination of two or more. From the viewpoint of weather resistance of the cured product, a phenol-based antioxidant is preferably used as the antioxidant. The blending ratio of the antioxidant is, for example, 1 x 10 per part by mass of the above-mentioned cured product. －６ Parts by mass (ppm) or more, preferably 10 x 10 －６ Parts by mass (ppm) or more, more preferably 100 x 10 －６ From the viewpoint of cost efficiency, the blending ratio of the antioxidant is, for example, 100,000×10 parts by mass (ppm) or more relative to 1 part by mass of the cured product. －６ Parts by mass (ppm) or less, preferably 10,000 x 10 －６ parts by mass (ppm) or less, more preferably 1000 x 10 －６ It is less than parts by mass (ppm).

[0262] (4) Physical Properties The cured product contains the composition (i.e., a composition containing the first compound and the second compound) and therefore has an excellent refractive index, excellent flexibility, excellent transparency, and excellent weather resistance.

[0263] The refractive index of the cured product is relatively high. The refractive index of the cured product is, for example, 1.45 or more, preferably 1.50 or more, more preferably 1.55 or more, even more preferably 1.60 or more, and particularly preferably 1.61 or more. The refractive index of the cured product is, for example, 1.80 or less, preferably 1.70 or less. The refractive index is measured in accordance with the examples described below.

[0264] The tensile storage modulus (E') of the cured product at 25°C is relatively low. The tensile storage modulus (E') of the cured product at 25°C is, for example, 1000 MPa or less, preferably 800 MPa or less, more preferably 500 MPa or less, even more preferably 300 MPa or less, even more preferably 200 MPa or less, still more preferably 100 MPa or less, and particularly preferably 50 MPa or less. The tensile storage modulus (E') of the cured product at 25°C is, for example, 1 MPa or more. The tensile storage modulus (E') is measured in accordance with the examples described below.

[0265] (5) Uses The cured product described above is suitable for use in various industrial fields. Uses of the cured product include, for example, resin molded products, films, and pressure-sensitive adhesives. A preferred use of the cured product is pressure-sensitive adhesives.

[0266] The adhesive is a cured curable composition. For example, the adhesive is a cured product of a curable composition containing a polyurethane resin raw material and / or an acrylic resin raw material (preferably an acrylic resin raw material) as a curable compound. The adhesive has a relatively low glass transition temperature (0°C or lower) and is adhesive (tacky).

[0267] The cured product has an excellent refractive index, flexibility, transparency, and weather resistance. Therefore, the cured product is suitable for use as an optical resin. Examples of applications of the optical resin include optical lenses, optical films, and optical pressure-sensitive adhesives.

[0268] The curable composition, adhesive, and pressure-sensitive adhesive each contain the plasticizer, and therefore, such a curable composition can provide a cured product that has an excellent refractive index, flexibility, transparency, and weather resistance.

[0269] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited thereto. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be substituted with the corresponding upper limit values ​​(numerical values ​​defined as "equal to or less than") or lower limit values ​​(numerical 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."

[0270] 1. Synthesis of Plasticizers Example 1 A composition containing 4-phenethylthiomethyl-1,8-bisphenethylthio-3,6-dithiaoctane (PE-GST) and S,S'-diphenethyldimercaptoethane (DPE-DME) as plasticizers was synthesized by the following method.

[0271] First, 204.9 mg (1.25 mmol) of AIBN (azobisisobutyronitrile) as a radical polymerization initiator and 250 mL of ethyl acetate as a reaction solvent were placed in a four-neck flask equipped with a stirrer, a thermometer, a nitrogen inlet line, and a dropping funnel, and the AIBN was dissolved in the ethyl acetate.

[0272] Next, 65.0 g of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST, 249.5 mmol) as a thiol compound and 80.6 g (773.5 mmol) of styrene as a carbon-carbon double bond-containing compound were slowly placed in the flask with stirring.

[0273] The equivalent ratio of styrene to GST (styrene / GST) was 3.1. That is, the equivalent ratio of carbon-carbon double bonds of styrene to mercapto groups of GST (carbon-carbon double bond / mercapto group) was 1.03. The ratio of the radical polymerization initiator to GST was 0.5 mol%.

[0274] Nitrogen gas was then supplied to the contents of the flask at a rate of 10 mL / min and bubbled for 3 hours. After stopping the bubbling, the contents of the flask were heated to 60°C and reacted at 60°C for 48 hours under a nitrogen atmosphere to obtain a reaction product.

[0275] The flask was then allowed to cool until the temperature of the reaction product reached room temperature, and the reaction product was then dried under reduced pressure at 60°C to distill off the ethyl acetate.

[0276] The reaction products were then analyzed by high performance liquid chromatography / mass spectrometry (hereinafter referred to as LC / MS analysis). More specifically, the reaction products were separated by high performance liquid chromatography (UV detector: 254 nm, mobile phase: acetonitrile), and the molecular weights of the components contained in each separated peak were analyzed by mass spectrometry (detector: ESI).

[0277] Mass spectrometry detected a peak containing a compound with a molecular weight of 572.17 (a compound corresponding to PE-GST) and a peak containing a compound with a molecular weight of 302.12 (a compound corresponding to DPE-DME).

[0278] The components corresponding to the above peaks were separated by silica gel column chromatography (developing solvent: hexane / ethyl acetate). １ H-NMR (400MHz, CDCl ３ As a result, the components corresponding to the above peaks were identified as PE-GST and DPE-DME, respectively.

[0279] １ H-NMR (400MHz, CDCl ３ ): [PE-GST] δ7.37-7.06 (m, 15H) δ3.04-2.58 (m, 25H)

[0280] [DPE-DME] δ7.31 (t, 4H) δ7.24-7.20 (m, 6H) δ2.91-2.88 (m, 4H) δ2.82-2.79 (m, 4H) δ2.72 (s, 4H)

[0281] ​That is, it was confirmed that the reaction product was a composition containing PE-GST and DPE-DME.

[0282] The area ratio of each peak in the high performance liquid chromatogram (HPLC) was calculated. The area ratio of the peak corresponding to PE-GST to the total peak area was 61.0%, and the area ratio of the peak corresponding to DPE-DME to the total peak area was 1.2%.

[0283] The resulting composition was a colorless, transparent liquid. The viscosity of the composition (25°C) was 430 mPa·s. The refractive index (nD) of the composition was 1.617.

[0284] Example 2 The amount of AIBN used as the radical polymerization initiator was changed from 204.9 mg (1.25 mmol) to 2049 mg (12.5 mmol). The ratio of the radical polymerization initiator to GST was 5.0 mol%. The reaction temperature was changed from 60°C to 80°C. A reaction product was obtained in the same manner as in Example 1, except for the above.

[0285] Then, using the same method as in Example 1, it was confirmed that the reaction product was a composition (plasticizer) containing PE-GST and DPE-DME.

[0286] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the peak area of ​​the peak corresponding to PE-GST was 56.5% of the total peak area, and the peak area of ​​the peak corresponding to DPE-DME was 1.4% of the total peak area.

[0287] The resulting composition was a colorless, transparent liquid. The viscosity of the composition (25°C) was 430 mPa·s. The refractive index (nD) of the composition was 1.617.

[0288] Example 3 A reaction product was obtained in the same manner as in Example 2, except that the reaction solvent was changed from ethyl acetate to toluene.

[0289] Then, using the same method as in Example 1, it was confirmed that the reaction product was a composition (plasticizer) containing PE-GST and DPE-DME.

[0290] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the peak area of ​​the peak corresponding to PE-GST was 48.5% of the total peak area, and the peak area of ​​the peak corresponding to DPE-DME was 2.2% of the total peak area.

[0291] The resulting composition was a colorless, transparent liquid. The viscosity of the composition (25°C) was 380 mPa·s. The refractive index (nD) of the composition was 1.617.

[0292] Example 4 As the radical polymerization initiator, V-65 (2,2'-azobis(2,4-dimethylvaleronitrile), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used instead of AIBN. The amount of V-65 was adjusted to 3100 mg (12.5 mmol). The ratio of the radical polymerization initiator to GST was 5.0 mol%. The reaction temperature was changed from 60°C to 40°C. Aside from the above, a reaction product was obtained in the same manner as in Example 2.

[0293] Then, using the same method as in Example 1, it was confirmed that the reaction product was a composition containing PE-GST and DPE-DME.

[0294] Then, using the same method as in Example 1, it was confirmed that the reaction product was a composition (plasticizer) containing PE-GST and DPE-DME.

[0295] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the peak area of ​​the peak corresponding to PE-GST was 62.1% of the total peak area, and the peak area of ​​the peak corresponding to DPE-DME was 1.2% of the total peak area.

[0296] Example 5 The reaction temperature was changed from 60° C. to 100° C. Except for the above, a reaction product was obtained in the same manner as in Example 1.

[0297] Then, using the same method as in Example 1, it was confirmed that the reaction product was a composition (plasticizer) containing PE-GST and DPE-DME.

[0298] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the peak area of ​​the peak corresponding to PE-GST was 59.9% of the total peak area, and the peak area of ​​the peak corresponding to DPE-DME was 1.4% of the total peak area.

[0299] Example 6 (Activated Carbon Purification) A reaction product was obtained in the same manner as in Example 1. Next, 5.0 g of the reaction product was placed in a 100 mL recovery flask, and 20 mL of ethyl acetate was further placed in the recovery flask to dissolve the reaction product, thereby obtaining a solution.

[0300] Next, 0.5 g of activated carbon (Shirasagi A, Dry type, manufactured by Osaka Gas Chemicals Co., Ltd.) was added to the resulting solution. A reflux condenser was attached to the recovery flask. The solution was then heated in an oil bath and maintained at reflux for 6 hours.

[0301] The recovery flask was then removed from the oil bath, and the solution was allowed to cool at room temperature. It was then left to stand at room temperature for 18 hours. The activated carbon was then filtered out of the solution using pleated filter paper. The filtrate was then dried under reduced pressure at 60°C to remove the ethyl acetate. This yielded a composition (plasticizer) containing PE-GST and DPE-DME. The recovered amount of the composition was 4.9 g.

[0302] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the peak area ratio of the peak corresponding to PE-GST was 63.4% of the total peak area, and the peak area ratio of the peak corresponding to DPE-DME was 1.1% of the total peak area. Example 7 (Column-Based Purification) A reaction product was obtained in the same manner as in Example 1. Next, 5.0 g of the reaction product was placed in a test tube, and 20 mL of toluene was further added to the test tube to dissolve the reaction product, thereby obtaining a solution.

[0303] Next, 20 mL of a 10% aqueous potassium hydroxide solution was added to the resulting solution and mixed to obtain a mixed solution, which was then separated using a separatory funnel and the organic layer was taken out.

[0304] The organic layer was then washed with 20 mL of pure water, and then dried under reduced pressure at 60°C. As a result, a composition (plasticizer) containing PE-GST and DPE-DME was obtained. The recovered amount of the composition was 4.8 g.

[0305] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the peak area of ​​the peak corresponding to PE-GST was 72.4% of the total peak area, and the peak area of ​​the peak corresponding to DPE-DME was 1.0% of the total peak area.

[0306] Comparative Example 1 (DPE-DME Removal) A reaction product was obtained in the same manner as in Example 1. DPE-DME was removed from the reaction product by silica gel column chromatography (developing solvent: hexane / ethyl acetate). In this way, a composition (plasticizer) was obtained. The obtained composition was a white suspended liquid.

[0307] In the high performance liquid chromatogram (UV detector: 254 nm) of the above composition, the ratio of the peak area of ​​the peak corresponding to PE-GST to the total peak area was 64.4%, and no peak corresponding to DPE-DME was detected.

[0308] Comparative Example 2 (Bz-GST) As a plasticizer, 4-benzoylthiomethyl-1,8-bisbenzoylthio-3,6-dithiaoctane (Bz-GST) was synthesized by the following method.

[0309] First, 30.0 g (115.2 mmol) of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST) was placed in a four-neck flask equipped with a stirrer, a thermometer, a nitrogen inlet line, and a dropping funnel.

[0310] Next, 100 mL of dichloromethane was added to the flask, thereby obtaining a solution of GST.

[0311] Next, 38.5 g (380.0 mmol) of triethylamine was slowly added to the GST solution while stirring, thereby obtaining a reaction solution of triethylamine and GST.

[0312] The reaction solution was then cooled in an ice bath, and 53.4 g (380.0 mmol) of benzoyl chloride was added dropwise to the reaction solution while maintaining the internal temperature of the reaction solution at 10° C. or lower.

[0313] The equivalent ratio of chlorine atoms in benzoyl chloride to mercapto groups in GST (chlorine atoms / mercapto groups) was 1.10.

[0314] The ice bath was then removed from the reaction solution, allowing the temperature of the reaction solution to reach room temperature, and the reaction solution was stirred overnight.

[0315] Thereafter, 300 mL of water and 200 mL of dichloromethane were added to the reaction solution. Then, these mixtures were separated, and the organic phase was removed. Next, the organic phase was washed with dilute hydrochloric acid. Furthermore, the organic phase was washed with saturated aqueous sodium bicarbonate solution. Thereafter, the organic phase was concentrated using an evaporator. This resulted in a concentrated reaction solution.

[0316] The concentrate (crude product) was diluted with 100 mL of dichloromethane to obtain a diluted solution. The diluted solution was passed through 100 mL of silica gel. 300 mL of dichloromethane was used to drain the diluted solution. The diluted solution was then concentrated using an evaporator. As a result, 4-benzoylthiomethyl-1,8-bisbenzoylthio-3,6-dithiaoctane (Bz-GST) was obtained as the reaction product.

[0317] Bz-GST was a colorless, transparent liquid. The yield of Bz-GST was 63.2 g. The viscosity of Bz-GST (25°C) was 5000 mPa s. The refractive index (nD) of Bz-GST was 1.65.

[0318] In addition, Bz-GST is as follows: １ H-NMR (400MHz, CDCl ３ ) was identified.

[0319] １ H-NMR (400MHz, CDCl ３ ​): δ7.89-8.01 (m, 6H) δ7.51-7.61 (m, 3H) δ7.37-7.48 (m, 6H) δ2.79-3.59 (m, 13H)

[0320] Comparative Example 3 (PP-GST) As a plasticizer, 4-(3-phenylpropionyl)thiomethyl-1,8-bis(3-phenylpropionyl)thio-3,6-dithiaoctane (PP-GST) was synthesized by the following method.

[0321] First, 50.0 g (191.9 mmol) of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (GST) was placed in a four-neck flask equipped with a stirrer, a thermometer, a nitrogen inlet line, and a dropping funnel.

[0322] Next, 250 g of toluene was added to the flask, thereby obtaining a solution of GST.

[0323] Next, 61.8 g (610.3 mmol) of triethylamine was slowly added to the GST solution while stirring, thereby obtaining a reaction solution of triethylamine and GST.

[0324] The reaction solution was then cooled in an ice bath, and 100.0 g (593.1 mmol) of 3-phenylpropionyl chloride was added dropwise to the reaction solution while maintaining the internal temperature of the reaction solution at 15° C. or lower.

[0325] The equivalent ratio of chlorine atoms in 3-phenylpropionyl chloride to mercapto groups in GST (chlorine atoms / mercapto groups) was 1.03.

[0326] After the dropwise addition was completed, the reaction solution was stirred for 2 hours while maintaining the internal temperature of the reaction solution at 15°C or below.

[0327] Then, 550 g of a 10% aqueous solution of sodium chloride was added to the reaction solution. The mixture was then separated, and the organic phase was separated. The organic phase was then washed with 500 mL of 1N diluted hydrochloric acid, followed by 500 mL of saturated aqueous sodium bicarbonate solution. It was then further washed with 500 mL of pure water.

[0328] The washings were passed through activated alumina (300 mesh, basic, for chromatography), and 120 g of toluene was used to flush out the reaction product remaining in the alumina.

[0329] After the liquid was passed through the washings, anhydrous sodium sulfate was added to the washings and stirred to remove any remaining water. The sodium sulfate was filtered off using pleated filter paper to obtain a toluene diluted solution of the product. The diluted solution was then concentrated using an evaporator. This yielded the reaction product 4-(3-phenylpropionyl)thiomethyl-1,8-bis(3-phenylpropionyl)thio-3,6-dithiaoctane (PP-GST).

[0330] PP-GST was a pale yellow, transparent liquid. The yield of PP-GST was 119.0 g. The viscosity of PP-GST (25°C) was 400 mPa s. The refractive index (nD) of PP-GST was 1.60.

[0331] The PP-GST is as follows: １ H-NMR (400MHz, CDCl ３ ) was identified.

[0332] １ H-NMR (400MHz, CDCl ３ ): δ7.13-7.33 (m, 15H) δ2.66-3.29 (m, 25H)

[0333] Comparative Example 4 (DOP) Dioctyl phthalate (DOP) was prepared as a known plasticizer.

[0334] The reaction conditions and physical properties of the reaction products in Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 1.

[0335] 2. Preparation of Curable Compositions Examples 8 to 17 and Comparative Examples 5 to 8 (1) Curable Compounds The following curable compounds were prepared: FA512-AS (radical polymerizable monomer, dicyclopentenyloxyethyl acrylate, manufactured by Resonac) UC-102M (radical polymerizable monomer, methacryloyl group-containing isoprene rubber, manufactured by Kuraray)

[0336] ​The following photopolymerization initiator was also prepared: Omnirad 184 (photopolymerization initiator, chemical name: 1-hydroxycyclohexyl phenyl ketone, manufactured by IGM Resins B.V.)

[0337] (2) Curable Compositions Curable compositions were prepared using the plasticizers of each Example and Comparative Example according to the formulations shown in Table 2. More specifically, 80 parts by mass of FA512-AS (curable compound), 20 parts by mass of UC-102M (curable compound), 4 parts by mass of Omnirad 184 (photopolymerization initiator), and 10 phr of the above plasticizer were mixed together. Note that phr indicates the parts by mass of the plasticizer relative to 100 parts by mass of the total amount of the curable compound and photopolymerization initiator.

[0338] In addition, a curable composition was prepared in the same manner as in each of the Examples and Comparative Examples, except that no plasticizer was used. This curable composition was used as a control.

[0339] 3. Production of Cured Product The curable composition was cured to obtain a cured product.

[0340] More specifically, a coating of the curable composition was sandwiched between release PET films (polyethylene terephthalate film, Purex A3100, manufactured by Toyobo Co., Ltd.) in a mold frame made of a 200 μm-thick silicone sheet. At this time, the release surface of the release PET film was brought into contact with the curable composition. This resulted in a laminate 1 (release PET film / curable composition / release PET film).

[0341] Next, Laminate 1 (release PET film / curable composition / release PET film) was sandwiched between glass substrates (D263T-eco, manufactured by SCHOTT) and fixed with clips. That is, the coating film of the curable composition was sandwiched between the glass substrates and the release PET films, thereby obtaining Laminate 2 (glass substrate / release PET film / curable composition / release PET film / glass substrate).

[0342] Thereafter, using an LED light source (365 nm), the curable composition of the laminate 2 was irradiated with active energy rays (wavelength 365 nm, illuminance 400 mW / cm ２, cumulative light intensity 6000 mJ / cm ２ ) was irradiated. Furthermore, Laminate 2 was heated at 120°C for 30 minutes in a nitrogen atmosphere. As a result, the curable composition underwent radical polymerization by the active energy rays and heat, and Laminate 3 (glass substrate / release PET film / cured product / release PET film / glass substrate) containing a cured product was obtained.

[0343] The clips and glass substrate were then removed, and the cured product was peeled off from the release PET film. As a result, a cured product was obtained. The refractive index (nD), tensile storage modulus (E'), and glass transition temperature (Tg) of the cured product were measured by the methods described below. The results are shown in Table 1.

[0344] Separately from the above, the curable composition was sandwiched between glass substrates (Eagle-XG, manufactured by Corning) in a mold made of a 50 μm-thick silicone sheet, thereby obtaining a laminate 4 (glass substrate / curable composition / glass substrate).

[0345] Thereafter, using an LED light source (365 nm), the curable composition of the laminate 4 was irradiated with active energy rays (wavelength 365 nm, illuminance 400 mW / cm ２ , cumulative light intensity 6000 mJ / cm ２ ) was irradiated. Furthermore, Laminate 4 was heated at 120°C for 30 minutes in a nitrogen atmosphere. As a result, the curable composition underwent radical polymerization by the active energy rays and heat, and Laminate 5 (glass substrate / cured product / glass substrate) containing a cured product was obtained.

[0346] 4. Evaluation (1) Refractive Index (nD) The refractive index (nD) of the cured product was measured using an Abbe refractometer (DR-M4, manufactured by Atago Co., Ltd.). The temperature was room temperature (20°C). The light used was d-line (wavelength 587.6 nm). The higher the refractive index of the cured product, the better the refractive index of the cured product was judged to be.

[0347] (2) Transparency and Weather Resistance The b* (yellowing index, before weather resistance test) of Laminate 5 (glass substrate / cured product / glass substrate) was measured using a COH-7700 (spectroscopic color haze meter, manufactured by Nippon Denshoku Industries Co., Ltd.). When the b* before the weather resistance test was less than 1, the transparency was determined to be good.

[0348] Laminate 5 (glass substrate / cured product / glass substrate) was exposed to ultraviolet light under the following conditions. Thereafter, the b* (yellowing index, after weather resistance test) of Laminate 5 (glass substrate / cured product / glass substrate) was measured using a COH-7700 (Nippon Denshoku Industries Co., Ltd., spectral color haze meter). Note that if b* (yellowing index) after the weather resistance test was less than 1, it was determined that the weather resistance was good.

[0349] <Ultraviolet rays> Equipment: UVACUBE400+SOL500 (manufactured by Honle UV Technology) Light source: Metal halide lamp Irradiation conditions: 70 W / m2 (300-400 nm) Filter: H2 filter (cuts out 295 nm or less, manufactured by Honle UV Technology) Irradiation time: 120 hours

[0350] (3) Flexibility (glass transition temperature (Tg) and tensile storage modulus (E')) The solid viscoelasticity of the cured product was measured under the following conditions. The tensile storage modulus (E') at 25°C was then determined. The loss tangent (tan δ) was also determined. The temperature at the peak value of the loss tangent (tan δ) was calculated as the glass transition temperature (Tg). The lower the glass transition temperature (Tg) of the cured product, the more excellent the flexibility of the cured product. The lower the tensile storage modulus (E'), the more excellent the flexibility of the cured product.

[0351] Apparatus: RSA-G2 (manufactured by TA Instruments) Deformation mode: Tensile mode Temperature range: -50°C to 270°C Temperature rise rate: 3°C / min Frequency: 1Hz Environment: N ２ environment

[0352] The formulations of the curable compositions in Examples 8 to 14 and Comparative Examples 5 to 8, and the evaluation results of the cured products, are shown in Table 2.

[0353]

[0354]

[0355] Details of the abbreviations in the table are as follows: PE-GST: 4-phenethylthiomethyl-1,8-bisphenethylthio-3,6-dithiaoctane DPE-DME: S,S'-diphenethyldimercaptoethane GST: 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane AIBN: azobisisobutyronitrile V-65: 2,2'-azobis(2,4-dimethylvaleronitrile), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Bz-GST: 4-benzoylthiomethyl-1,8-bisbenzoylthio-3,6-dithiaoctane PP-GST: 4-(3-phenylpropionyl)thiomethyl-1,8-bis(3-phenylpropionyl)thio-3,6-dithiaoctane DOP: dioctyl phthalate HPLC area % PE-GST: Peak area ratio of the peak corresponding to PE-GST in the high performance liquid chromatogram (HPLC) HPLC area % DPE-DME: Peak area ratio of the peak corresponding to DPE-DME in the high performance liquid chromatogram (HPLC)

[0356] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are intended to be included in the scope of the following claims.

[0357] The composition, additive, plasticizer, curable composition, adhesive, cured product and pressure-sensitive adhesive of the present invention are suitably used in the optical field.

Claims

1. A composition comprising a first compound which is a reaction product of a thiol compound having a functional group represented by the following formula (1) and a carbon-carbon double bond-containing compound represented by the following formula (2), and a second compound represented by the following formula (3). (In formula (1), A represents an alkylene group having 2 to 3 carbon atoms.) (In formula (2), R1, R2 and R3 represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an araliphatic hydrocarbon group. R1, R2 and R3 may be the same or different.) (In formula (3), A has the same meaning as A in formula (1). R1, R2, R3 and Ar have the same meanings as R1, R2, R3 and Ar in formula (2).) 2. The composition according to claim 1, wherein the thiol compound has a functional group represented by the following formula (4), and the second compound is a compound represented by the following formula (5). (In formula (5), R1, R2, R3 and Ar have the same meanings as R1, R2, R3 and Ar in formula (2).) 3. The composition according to claim 1, wherein the thiol compound is a compound represented by the following formula (6), and the carbon-carbon double bond-containing compound is styrene.

4. In the chromatogram obtained by high performance liquid chromatography measurement at a detection wavelength of 254 nm, the area ratio of the peak corresponding to the first compound is 45 to 95% with respect to the total area of all peaks, and the area ratio of the peak corresponding to the second compound is 0.5 to 10% with respect to the total area of all peaks. The composition according to claim 1.

5. A plasticizer comprising the composition according to claim 1.

6. A curable composition comprising the plasticizer according to claim 5 and a curable compound.

7. An adhesive comprising the curable composition according to claim 6.

8. A cured product comprising the plasticizer according to claim 5 and a cured resin.

9. The cured product according to claim 8, wherein the cured resin comprises a reaction product of a main agent containing acrylic polyol and a curing agent containing polyisocyanate.

10. The cured product according to claim 8, wherein the cured resin comprises a cured acrylic resin.

11. An adhesive comprising the cured product according to claim 8.

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