WO 2017/209104
`
`PCT/J P2017/020027
`
`Title of the Invention: Eyeglass Lens
`
`The present invention relates to an eyeglass lens.
`
`Technical Field
`
`Prior Art
`
`Patent literature 1 discloses “an ultraviolet-absorbing plastic lens containing an ultraviolet
`
`absorber having a molecular weight of 360 or less at a ratio of 0.7-5 parts by weight with
`
`respect to 100 parts by weight of raw material monomer”.
`
`Patent Literature
`
`Prior Art Literature
`
`Patent literature 1: Japanese Laid-Open Patent Application Publication JP H11-271501
`
`Summary of the Invention
`
`The present
`
`invention, according to the embodiments, provides an eyeglass lens
`
`prepared using a resin composition containing m-xylylene diisocyanate, a polythiol
`
`compound and an ultraviolet absorber, wherein the ultraviolet absorber contains at least a
`
`compound represented by formula (1) and a compound represented by formula (2) and
`
`the M value represented by formula (X) is greater than 1.40 but less than 3.20.
`
`[Structure 1]
`
`1
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`I
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`R
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`R4
`R9
`‘R3
`
`R2,
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`RS/f/
`
`R1?
`
`R15
`
`R39
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`R “
`\E
`R14
`R18
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`R”
`
`-
`
`73758191.1
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`Formula“)
`
`Formula (2)
`
`

`

`(In formula (1), R1-R9 each independently represent a hydrogen atom, an alkyl group, an
`
`alkoxy group, or a hydroxyl group. In formula (2), R11-R18 each independently represent a
`
`hydrogen atom, an alkyl group, an alkoxy group, or a hydroxyl group or a halogen atom,
`
`R19 represents a hydrogen atom, an alkyl group, an alkoxy group, or a phenylalkyl group
`
`or a group represented by the following formula (3). However,
`
`if R19 is a hydrogen atom,
`
`an alkyl group, or an alkoxy group, at least one of R11-R14 is a halogen atom.
`
`ln formula (3), L represents an alkylene group. R20 represents an optionally substituted
`
`aromatic hydrocarbon group or a heterocyclic ring group.)
`
`Formula (3) *-L-R20
`
`Formula (X) M value = |A2—)\1|><(A2/A1)><(W2NV1)
`
`(ln formula (X), A1
`
`represents the maximum absorption wavelength of a compound
`
`represented by formula (1) in the ultraviolet-visible absorption spectrum of a chloroform
`
`solution in which the concentration of a compound represented by formula (1) is 10 weight
`
`ppm. A2 represents the maximum absorption wavelength of a compound represented by
`
`formula (2) in the ultraviolet-visible absorption spectrum of a chloroform solution in which
`
`the concentration of a compound represented by formula (2)
`
`is 10 weight ppm. A1
`
`represents the absorbance at
`
`the maximum absorption wavelength of a compound
`
`represented by formula (1) in the ultraviolet-visible absorption spectrum of a chloroform
`
`solution in which the concentration of a compound represented by formula (1) is 10 weight
`
`ppm. A2
`
`represents the absorbance at
`
`the maximum absorption wavelength of a
`
`compound represented by formula (2) in the ultraviolet-visible absorption spectrum of a
`
`chloroform solution in which the concentration of a compound represented by formula (2)
`
`is 10 weight ppm. W1 represents the amount
`
`(in parts by weight) of a compound
`
`represented by formula (1) when the total of the m-xylylene diisocyanate and the polythiol
`
`compound is 100 parts by weight. W2 represents the amount (in parts by weight) of a
`
`compound represented by formula (2) when the total of the m-xylylene diisocyanate and
`
`the polythiol compound is 100 parts by weight.
`
`Brief Description of Drawings
`
`[Fig. 1] is a schematic view showing a typical ultraviolet-visible absorption spectrum of a
`
`compound represented by formula (1) and a compound represented by formula (2).
`
`73758191.1
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`The invention will be described in more detail in the following embodiments.
`
`Best Mode to Carry Out the Invention
`
`In the following description, there are cases in which constitutional requirements will be
`
`described on the basis of typical embodiments of the present invention, but the present
`
`invention is not limited to the above-described embodiments.
`
`In addition,
`
`in the present specification, a numerical range expressed by
`
`means a
`
`range including the numerical values described before and after
`
`as lower limit and
`
`10
`
`upper limit values.
`
`When the inventors of the present invention used the ultraviolet absorbing plastic lens
`
`specifically described in patent literature 1 to investigate the absorption rate (hereinafter
`
`also referred to as the “ultraviolet absorption rate”) of ultraviolet light (having a wavelength
`
`of 200-400nm) and the low degree of the yellowness index (hereinafter also referred to as
`
`"low yellowness"), it became clear that there was the problem in which the level required
`
`for current eyeglass lenses had not yet been reached.
`
`In addition, the yellowness index
`
`means the degree to which the eyeglass lens is colored yellow and is a value which can
`
`be measured by a method described later.
`
`Generally, an eyeglass lens containing an ultraviolet absorber has the problem that the
`
`yellowness index tends to be high. However,
`
`in order to impart excellent ultraviolet
`
`absorbency to the eyeglass lens,
`
`the required amount of ultraviolet absorber must be
`
`combined into the eyeglass lens. Therefore,
`
`in terms of the eyeglass lens properties,
`
`ultraviolet absorbency and low yellowness have been considered to have a trade-off
`
`relationship.
`
`The inventors of the present invention have found that if use is made of an eyeglass lens
`
`in which the above-described ultraviolet absorber, which contains a predetermined
`
`monomer and an ultraviolet absorber, contains two kinds of predetermined compound,
`
`and in which the M value calculated from the content and physical properties of the two
`
`kinds of compounds is within a predetermined range, it is possible to provide an eyeglass
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`73758191 .1
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`

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`lens having excellent ultraviolet absorbency and low yellowness and have achieved the
`
`present invention.
`
`[Eyeglass Lens]
`
`The eyeglass lens in the present embodiment is an eyeglass lens prepared using a resin
`
`composition containing m-xylylene diisocyanate, a polythiol compound and an ultraviolet
`
`absorber, wherein the ultraviolet absorber contains at least a compound represented by
`
`formula (1) and a compound represented by formula (2) wherein the M value represented
`
`by formula (X) is greater than 1.40 but less than 3.20.
`
`An eyeglass lens having such a composition has excellent ultraviolet absorbency and low
`
`yellowness. The reason will be described with reference to Fig. 1 below.
`
`Fig. 1 shows a typical ultraviolet-visible absorption spectrum of a compound represented
`
`by formula (1) and a typical ultraviolet-visible absorption spectrum of a compound
`
`represented by formula (2). The two ultraviolet-visible absorption spectra were measured
`
`using a solution prepared by dissolving a compound represented by formula (1) and a
`
`compound represented by formula (2) in chloroform each at a concentration of 10 weight
`
`ppm.
`
`In Fig 1,
`
`the X—axis represents wavelength (nm) and the Y-axis represents the
`
`absorbance. Fig.
`
`1
`
`is purely an example and the typical ultraviolet-visible absorption
`
`spectrum of an ultraviolet absorber represented by formula (1) and the typical ultraviolet-
`
`visible absorption spectrum of an ultraviolet absorber represented by formula (2) are not
`
`limited to the embodiment in Fig. 1.
`
`Further,
`
`in Fig. 1, curve A shown by the dot-dash line represents the ultraviolet-visible
`
`absorption spectrum of a compound represented by formula (1). A compound represented
`
`by formula (1) has a benzotriazole structure and usually has a maximum absorption
`
`wavelength A1 in the range of 300-380nm. A compound represented by formula (1) with
`
`such ultraviolet absorption properties exhibits excellent ultraviolet absorbency in the range
`
`less than 380nm but has almost no absorption in the visible light range (approximately
`
`400—800nm). Therefore, the absorbance at around 400nm of a compound represented by
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`formula (1) is relatively low.
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`73758191 .1
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`

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`In Fig. 1, curve B shown by the solid line represents the ultraviolet-visible absorption
`
`spectrum of a compound represented by formula (2). A compound represented by formula
`
`(2) has a benzotriazole structure and has predetermined functional groups,
`
`the 1T-
`
`conjugation system is easily extended compared to a compound represented by formula
`
`(1) and readily absorbs light
`
`in a longer wavelength region. Therefore, a compound
`
`represented by formula (2) has higher absorbance in the range of 380-400nm than a
`
`compound represented by formula (1). Thus, the absorbance of a compound represented
`
`by formula (2) at around 400nm is higher
`
`than the absorbance of a compound
`
`represented by formula (1) at around 400nm.
`
`On the other hand, since a compound represented by formula (2) readily absorbs visible
`
`light at 400nm and above, the eyeglass lens incorporating this compound readily yellows.
`
`The inventors of the present invention have found that upon using a predetermined
`
`monomer and simultaneously using two kinds of compounds having different ultraviolet
`
`absorption properties set forth above as the ultraviolet absorbing agent and with the M
`
`value calculated from the content and physical properties of the two kinds of compounds
`
`being within a predetermined range, an eyeglass having excellent ultraviolet absorbency
`
`and low yellowness can be provided.
`
`Hereinafter, the technical significance of the M value will be described in more detail.
`
`In addition,
`
`if only a compound represented by formula (1)
`
`is used as an ultraviolet
`
`absorber, the resulting eyeglass lens shows an insufficient ultraviolet absorption rate (in
`
`particular, the ultraviolet absorption rate in the range of 380-400nm). Further, from the
`
`viewpoint of compatibility with resin components in the eyeglass lens,
`
`it is impossible to
`
`incorporate a large amount of a compound represented by formula (1) in the eyeglass
`
`lens. Furthermore, when a compound represented by formula (2) alone is used as an
`
`ultraviolet absorber,
`
`the resulting eyeglass lens tends to readily yellow. As described
`
`above, when only one kind of ultraviolet absorber was used, it was impossible to achieve
`
`both an excellent ultraviolet absorption rate and low yellowing in a well-balanced manner.
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`73758191 .1
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`[M value]
`
`The M value is a value represented by the following formula (X).
`
`Formula (X) M value = |A2—)\1|><(A2/A1)><(W2NV1)
`
`(ln formula (X), A1
`
`represents the maximum absorption wavelength of a compound
`
`represented by formula (1) in the ultraviolet-visible absorption spectrum of a chloroform
`
`solution in which the concentration of a compound represented by formula (1) is 10 weight
`
`ppm (see Fig. 1). That is, the maximum absorption wavelength A1 refers to a wavelength
`
`exhibiting the maximum value in the ultraviolet-visible absorption spectrum obtained by
`
`ultraviolet-visible spectrophotometry (UV-Vis) using a solution in which a compound
`
`represented by formula (1) was dissolved in chloroform at a concentration of 10ppm by
`
`weight.
`
`In addition,
`
`if there are multiple maximum values,
`
`the maximum value on the
`
`longest wavelength side among the multiple maximum values is taken.
`
`Further, A2 represents the maximum absorption wavelength of a compound represented
`
`by formula (2) in the ultraviolet-visible absorption spectrum of a chloroform solution in
`
`which the concentration of a compound represented by formula (2) is 10 weight ppm (see
`
`Fig. 1). That is, the maximum absorption wavelength A2 refers to a wavelength exhibiting
`
`the maximum value in the ultraviolet-visible absorption spectrum obtained by ultraviolet-
`
`visible spectrophotometry (UV-Vis) using a solution in which a compound represented by
`
`formula (2) was dissolved in chloroform at a concentration of 10 weight ppm. In addition, if
`
`there are multiple maximum values, the maximum value on the longest wavelength side
`
`among the multiple maximum values is taken.
`
`In addition,
`
`in Fig. 1, two maxima are shown on curve B which is the ultraviolet-visible
`
`absorption spectrum of a compound represented by formula (2) and, among them, the
`
`wavelength showing the maximum value on the long wavelength side is set as the
`
`maximum absorption wavelength A2.
`
`As apparatus for measuring the ultraviolet-visible absorption spectrum, measurements are
`
`carried out using a spectrophotometer under the following conditions.
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`73758191 .1
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`Cell: quartz, width 1cm (corresponds to a 1cm optical path length)
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`Blank: solvent (chloroform)
`
`ln formula (X),
`
`|A2-A1|
`
`is the absolute value of the difference between A1 and A2 and
`
`indicates
`
`the difference in
`
`the maximum absorption wavelength of a compound
`
`represented by formula (1) and the maximum absorption wavelength of a compound
`
`represented by formula (2).
`
`If this value is too low, the absorption band becomes narrow
`
`and the ultraviolet absorbency of the eyeglass lens tends to be poor. However,
`
`if this
`
`value is too high, the absorption band tends to be in the visible light region and the low
`
`yellowness of the eyeglass lens tends to be poor.
`
`In addition, although the size of A1 is not particularly limited,
`
`it can be 340-350nm or 343-
`
`347nm from the viewpoint that the eyeglass lens of the present embodiment has superior
`
`ultraviolet absorbency and low yellowness.
`
`Although the size of A2 is not particularly limited, it can be 340-370nm or 341-354nm from
`
`the viewpoint that the eyeglass lens of the present embodiment has superior ultraviolet
`
`absorbency and low yellowness.
`
`Further, although the value of |A2.A1| is not particularly limited, it can be 0.1-30nm or 1-9nm
`
`from the viewpoint
`
`that
`
`the eyeglass lens of the present embodiment has superior
`
`ultraviolet absorbency and low yellowness.
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`In addition, in Fig. 1, although A2 is larger than A1,
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`it is not limited to this embodiment and
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`A1 may be larger than A2.
`
`ln formula (X), A1 represents the absorbance at the maximum absorption wavelength of a
`
`compound represented by formula (1) in the ultraviolet-visible absorption spectrum of a
`
`chloroform solution in which the concentration of a compound represented by formula (1)
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`30
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`is 10 weight ppm (see Fig.1). That is, absorbance A1 is the absorbance at the maximum
`
`absorption wavelength A1
`
`in an ultraviolet-visible absorption spectrum obtained by
`
`ultraviolet-visible spectrophotometry (UV-Vis) using a solution in which a compound
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`73758191 .1
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`

`

`represented by formula (1) was dissolved in chloroform at a concentration of 10ppm by
`
`weight.
`
`A2 represents the absorbance at the maximum absorption wavelength of a compound
`
`represented by formula (2) in the ultraviolet-visible absorption spectrum of a chloroform
`
`solution in which the concentration of a compound represented by formula (2) is 10 weight
`
`ppm (see Fig. 1). That is, absorbance A2 is the absorbance at the maximum absorption
`
`wavelength A2 in an ultraviolet-visible absorption spectrum obtained by ultraviolet-visible
`
`spectrophotometry (UV-Vis) using a solution in which a compound represented by formula
`
`(2) was dissolved in chloroform at a concentration of 10ppm by weight.
`
`The method of measuring the absorbance is the same as the method of measuring the
`
`maximum absorption wavelength described above.
`
`In formula (X), A2/A1 means the ratio of the amount of ultraviolet absorption at the
`
`maximum absorption wavelength of a compound represented by formula (2)
`
`to the
`
`amount of ultraviolet absorption at the maximum absorption wavelength of a compound
`
`represented by formula (1).
`
`If this value is too low, absorbency on the long wavelength
`
`side due to the absorption spectrum of a compound represented by formula (2) becomes
`
`insufficient, and the ultraviolet absorbency of
`
`the eyeglass lens tends to be poor.
`
`However,
`
`if this value is too high, absorbency on the long wavelength side becomes
`
`excessive, and the low yellowness of the eyeglass lens tends to be poor.
`
`Although the size of A1 is not particularly limited,
`
`it can be 0.2-2.0, further 0.3-2.0, further
`
`still 0.4-1.1 and also 0.7-1.1 from the viewpoint that the eyeglass lens of the present
`
`embodiment has superior ultraviolet absorbency and low yellowness.
`
`Although the size of A2 is not particularly limited,
`
`it can be 0.2-0.9 or 0.3-0.6 from the
`
`viewpoint
`
`that
`
`the eyeglass lens of the present embodiment has superior ultraviolet
`
`absorbency and low yellowness.
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`Further, although the value of A2/A1 is not particularly limited, it can be 0.1-4.5, further 0.2-
`
`3.4 and further still 0.3-0.6 from the viewpoint that the eyeglass lens of the present
`
`embodiment has superior ultraviolet absorbency and low yellowness.
`
`ln formula (X), W1 represents the amount (in parts by weight) of a compound represented
`
`by formula (1) when the total of the m-xylylene diisocyanate and the polythiol compound is
`
`100 parts by weight. That is, the above W1 corresponds to the amount (in parts by weight)
`
`of a compound represented by formula (1) with respect to 100wt% of monomer mixture
`
`composed of m-xylylene diisocyanate and a polythiol compound in the resin composition.
`
`W2 represents the amount (in parts by weight) of a compound represented by formula (2)
`
`when the total of the m-xylylene diisocyanate and the polythiol compound is 100 parts by
`
`weight. That
`
`is,
`
`the above W2 corresponds to the amount (in parts by weight) of a
`
`compound represented by formula (2) with respect to 100wt% of monomer mixture
`
`composed of m-xylylene diisocyanate and a polythiol compound in the resin composition.
`
`W2NV1 means the ratio of the amount of a compound represented by formula (2) to the
`
`amount of a compound represented by formula (1). If this value is too low, absorbency on
`
`the long wavelength side due to the absorption spectrum of a compound represented by
`
`formula (2) becomes insufficient, and the ultraviolet absorbency of the eyeglass lens tends
`
`to be poor. However,
`
`if this value is too high, absorbency on the long wavelength side
`
`becomes excessive, and the low yellowness of the eyeglass lens tends to be poor.
`
`The specific ranges relating to W1 and W2 will be described later in detail.
`
`As described above,
`
`if the values of the items constituting the M value are too low, the
`
`ultraviolet absorbency of the eyeglass lens tends to be poor and, if it is too high, the low
`
`yellowness of the eyeglass lens tends to be poor.
`
`Thus, the M value of the eyeglass lens of the present embodiment is greater than 1.40
`
`and less than 3.20. When the M value is below the lower limit value,
`
`the ultraviolet
`
`absorbency of the eyeglass lens is poor and, when it is above the upper limit value, the
`
`low yellowness of the eyeglass lens is poor. In particular, the M value can be greater than
`
`1.63 and less than 3.20 and can be greater than 1.63 and less than 2.75 from the
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`73758191 .1
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`viewpoint
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`that
`
`the eyeglass lens of the present embodiment has superior ultraviolet
`
`absorbency and low yellowness.
`
`Since, the eyeglass lens of the present embodiment is formed using a predetermined
`
`monomer as mentioned above and simultaneously using two kinds of compound having
`
`different ultraviolet absorption properties as ultraviolet absorbers and with the M value
`
`calculated from the content and physical properties of the ultraviolet absorber being within
`
`a predetermined range, it is assumed that both ultraviolet absorbency and low yellowness,
`
`which were considered to have a trade-off relationship, could coexist at a high level.
`
`(Resin Composition)
`
`The resin composition contains m-xylylene diisocyanate, a polythiol compound, and an
`
`ultraviolet absorber. Hereinafter, and each component present in the resin composition
`
`will be described in detail.
`
`(Ultraviolet Absorber)
`
`The ultraviolet absorber contains at
`
`least a compound represented by the following
`
`formula (1) and a compound represented by the following formula (2). These 2
`
`compounds (ultraviolet absorbers) are structurally similar and both show excellent
`
`compatibility.
`
`In addition,
`
`these 2 kinds of ultraviolet absorbers also exhibit excellent
`
`compatibility with the monomer described later and are easily dispersed uniformly in the
`
`eyeglass lens.
`
`Among the ultraviolet absorbers used in this embodiment, an ultraviolet absorber having a
`
`molecular weight of 360 or less can be used at less than 0.7 parts by weight when the
`
`total of m-xylylene diisocyanate and a polythiol compound is taken as 100 parts by weight.
`
`(Compound represented by formula (1))
`
`The ultraviolet absorber used in the present embodiment contains a compound (an
`
`ultraviolet absorber) represented by the following formula (1).
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`73758191.1
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`[Structure 2]
`
`R8
`
`R9
`
`R7
`
`Formula (1)
`
`In formula (1), R1-R9 each independently represent a hydrogen atom, an alkyl group (the
`
`number of carbon atoms can be 1-8), an alkoxy group (the number of carbon atoms can
`
`be 1-8), or a hydroxyl group. Among them, R1-R4 can be hydrogen atoms. Further, at least
`
`one of R5-R9 can be a hydroxyl group and R5 can be a hydroxyl group. Further, R7 can be
`
`an alkoxy group from the viewpoint that the eyeglass lens of the present embodiment has
`
`superior ultraviolet absorbency and low yellowness. The number of carbon atoms in the
`
`10
`
`alkoxy group can be 1-5.
`
`Although the molecular weight of a compound represented by the above formula (1) is not
`
`particularly limited,
`
`it can be 360 or less and can be 340 or less from the viewpoint of
`
`obtaining an eyeglass lens having superior low yellowness.
`
`In particular, the molecular
`
`weight of a compound represented by the above formula (1) can be 290 or less and can
`
`be 280 or less from the viewpoint of obtaining an eyeglass lens having superior ultraviolet
`
`absorbency. The lower limit value for the molecular weight of a compound represented by
`
`the above formula (1) is not particularly limited but is generally 210 or more.
`
`In addition, in the present specification, the molecular weight means the molecular weight
`
`which can be calculated from the structural formula.
`
`As an ultraviolet absorber represented by above-mentioned formula (1), 2-(2-hydroxy-5-
`
`methylpropyl)-2H-benzotriazole,
`
`2-(2-hydroxy-5-t-octylphenyl)-2H-benzotriazole,
`
`2—(4—
`
`ethoxy-2-hydroxyphenyl)-2H-benzotriazole,
`
`and
`
`2-(4-butoxy-2-hydroxyphenyl)-2H-
`
`benzotriazole and the like can be mentioned.
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`(Compound represented by formula (2))
`
`The ultraviolet absorber used in the present embodiment contains a compound (an
`
`ultraviolet absorber) represented by formula (2).
`
`[Structure 3]
`
`R15
`
`R19
`
`R13
`
`N
`
`N
`
`R14
`
`R18
`
`R17
`
`R16
`
`Formula (2)
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`ln formula (2), R11-R19 each independently represent a hydrogen atom, an alkyl group (the
`
`number of carbon atoms can be 1-8), an alkoxy group (the number of carbon atoms can
`
`be 1-8), or a hydroxyl group or a halogen atom (for example, fluorine, chlorine, bromine
`
`and the like). R11-R14 each independently represent a hydrogen atom, an alkyl, an alkoxy,
`
`or a hydroxyl group or a halogen atom, each can be a hydrogen atom, an alkyl, an alkoxy,
`
`or a hydroxyl group, each can be a hydrogen atom or an alkyl group or further each can
`
`be hydrogen atoms.
`
`In addition,
`
`if R19 is a hydrogen atom, an alkyl group, or an alkoxy
`
`group, at least one of R11-R14 is a halogen atom.
`
`R15 can be a hydroxyl group.
`
`R19 represents a hydrogen atom, an alkyl group (the number of carbon atoms can be 1-8),
`
`an alkoxy group (the number of carbon atoms can be 1-8), a phenylalkyl group (the
`
`number of carbon atoms is 1-8), or a group represented by the following formula (3), a
`
`phenylalkyl group, or a group represented by the following formula (3). In addition, in the
`
`present specification, a phenylalkyl group means a group in which at least one hydrogen
`
`atom in the phenyl group is substituted with an alkyl group.
`
`ln formula (3), L represents an alkylene group. R20 represents an optionally substituted
`
`aromatic hydrocarbon group or heterocyclic ring group. Examples of optionally substituted
`
`Formula (3) *-L-R20
`
`73758191.1
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`aromatic hydrocarbon groups include a phenyl group, a tolyl group, a xylyl group, a
`
`naphthyl group, and an anthryl group, and can be a phenyl group or a substituted phenyl
`
`group from the viewpoint that the ultraviolet absorbency on the longer wavelength side
`
`improves. The substituent is not particularly limited, for example, an alkyl group, an alkoxy
`
`group, a hydroxyl group, and a halogen atom can be mentioned and, among these, a
`
`hydroxyl group or an alkyl group can be used.
`
`As an optionally substituted heterocyclic group, aliphatic heterocyclic groups such as an
`
`oxetanyl group, a pyrrolidinyl group, a tetrahydrofuryl group, and a tetrahydrophthalamide
`
`group and the like and an aromatic heterocyclic group such as a thienyl group, a furanyl
`
`group, a pyridyl group, a pyrimidyl group, a thiazolyl group, an oxazolyl group, a triazolyl
`
`group, a benzothiophenyl group, a benzofuranyl group, a benzothiazolyl group, a
`
`benzoxazolyl group, and a benzotriazolyl group and the like can be mentioned.
`
`R17 can be an alkyl group and,
`
`in particular,
`
`it can be an alkyl group having 1-8 carbon
`
`atoms. As the kind of substituent, groups exemplified as substituents which may be
`
`substituted on the above aromatic hydrocarbon group can be mentioned.
`
`The molecular weight of a compound represented by the above formula (2)
`
`is not
`
`particularly limited and can be greater than 360, it can be greater than 380 and can even
`
`be greater than 400 from the viewpoint of obtaining an eyeglass lens having superior
`
`ultraviolet absorbency. The upper limit for the molecular weight of the 2nd compound is
`
`not particularly limited but is generally 1000 or less.
`
`A compound represented by the above formula (2) can be a compound represented by
`
`the following formula (4)
`
`from the viewpoint
`
`that
`
`the eyeglass lens of the present
`
`embodiment has superior ultraviolet absorbency and low yellowness.
`
`10
`
`15
`
`20
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`25
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`73758191.1
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`13
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`

`

`[Structure 4]
`
`R55
`
`L—R5O
`
`R58
`
`R57
`
`10
`
`15
`
`20
`
`25
`
`In formula (4), R51-R58 each independently represent a hydrogen atom, an alkyl group (the
`
`number of carbons can be 1-8), an alkoxy group (the number of carbons can be 1-8), or a
`
`hydroxyl group, L represents an a|ky|ene group (the number of carbon atoms can be 1-3),
`
`and R50 represents an optionally substituted aromatic hydrocarbon group or a heterocyclic
`
`ring group.
`
`In addition, the embodiments of R51-R54, R55-R58, and R50 are the same as
`
`those of the above-described R11-R14, R15-R18, and R20, respectively.
`
`As an ultraviolet absorber represented by the above-mentioned formula (2), 2—(3-tert-
`
`butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole,
`
`2—(2H-benzotriazol-2-yl)-4-
`
`methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 6-(2-benzotriazolyl)-4-t-octyl-6’-t-
`
`butyl-4’-methyl-2,2’-methylenebisphenol,
`
`and
`
`2—(2H-benzotriazol-2-yl)-6-(1-methyl-1-
`
`phenylethyl)-4-(1,1,3,3-tetramethylbutyl) phenol and the like can be mentioned.
`
`(Other Compounds)
`
`The ultraviolet absorber used in the present embodiment may contain at
`
`least a
`
`compound represented by formula (1) and a compound represented by formula (2) and,
`
`as long as the eyeglass lens of
`
`the present embodiment has superior ultraviolet
`
`absorbency and low yellowness, other compounds may be present as an ultraviolet
`
`absorber.
`
`(Ultraviolet absorber with a molecular weight of 360 or less)
`
`Among the ultraviolet absorbers used in this embodiment,
`
`the amount of ultraviolet
`
`absorber having a molecular weight of 360 or less can be used at less than 0.7 parts by
`
`weight when the total of m-xylylene diisocyanate and a polythiol compound is taken as
`
`100 parts by weight. If the amount of ultraviolet absorber having a molecular weight of 360
`
`or
`
`less is
`
`lower than the upper limit value, an eyeglass lens having superior low
`
`73758191.1
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`14
`
`

`

`yellowness can be obtained. The lower limit of the amount of ultraviolet absorber having a
`
`molecular weight of 360 or less is not particularly limited and can be 0.001 parts by weight
`
`or more, further 0.01 parts by weight or more and further still 0.1 parts by weight or more
`
`from the viewpoint of obtaining an eyeglass lens having superior ultraviolet absorbency.
`
`In addition,
`
`the above-mentioned "amount of ultraviolet absorber having a molecular
`
`weight of 360 or less" means the sum of the amounts when the resin composition used in
`
`the present embodiment contains multiple compounds having a molecular weight of 360
`
`or less as an ultraviolet absorber.
`
`The amount of ultraviolet absorber
`
`in the resin composition used in the present
`
`embodiment can be 0.01-7.0 parts by weight, further 0.1-6.0 parts by weight and further
`
`still 0.1-5.0 parts by weight when the total of m-xylylene diisocyanate and a polythiol
`
`compound is taken as 100 parts by weight from the viewpoint that the eyeglass lens of the
`
`present embodiment has superior ultraviolet absorbency and low yellowness.
`
`In particular, the amount W1 (in parts by weight) of a compound represented by the above
`
`formula (1) and the amount W2 (in parts by weight) of a compound represented by the
`
`above formula (2) are not particularly limited.
`
`In particular, W1 can be 0.001-0.7 parts by
`
`weight and 0.01-0.7 parts by weight when the total of m-xylylene diisocyanate and a
`
`polythiol compound is taken as 100 parts by weight from the viewpoint that the eyeglass
`
`lens of the present embodiment has superior ultraviolet absorbency and low yellowness.
`
`W2 can be 0.001-4.0 parts by weight, further 0.01-4.0 parts by weight, and further still 0.1-
`
`4.0 parts by weight.
`
`The sum (W1+W2) of the amount W1 of a compound represented by formula (1) and the
`
`amount W2 of a compound represented by formula (2) is not particularly limited and can
`
`be 0.01 parts by weight and, from the viewpoint of obtaining an eyeglass lens having
`
`superior ultraviolet absorbency, can be 0.1 parts by weight, further 1.0 parts by weight and
`
`further still 1.5 parts by weight.
`
`In addition, the upper limit value is not particularly limited
`
`and can be 7.0 parts by weight or less and 5.0 parts by weight or less from the viewpoint
`
`that an eyeglass lens having superior low yellowness can be obtained.
`
`10
`
`15
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`20
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`25
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`30
`
`73758191 .1
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`15
`
`

`

`Although the value of W1/W2 is not particularly limited,
`
`it can be 0.01-100, further 005-10
`
`and further still 0.5-3 from the viewpoint that the eyeglass lens of the present embodiment
`
`has superior ultraviolet absorbency and low yellowness.
`
`(Polythiol Compound)
`
`The polythiol compound is not particularly limited as long as it has 2 or more mercapto
`
`groups in the molecule but
`
`it may have 3 or 4 mercapto groups and,
`
`for example,
`
`pentaerythritol tetrakis thioglycolate, pentaerythritol tetrakis (3-mercaptopropionate), 1,2-
`
`bis[(2-mercaptoethyl)thio]-3-mercaptopropane,
`
`4-mercaptomethyl-3,6-dithia-1,8-
`
`octanedithiol ethanedithiol and bis(mercaptomethyl)—3,6,9-trithio-1,11-undecanedithiol can
`
`be mentioned. One kind of polythiol compound may be used alone or two or more kinds
`
`may be used in combination.
`
`Other than the above-mentioned polythiol compounds,
`
`the compounds described in
`
`paragraphs [0051-0058] in Japanese Laid-Open Patent Application Publication JP2015-
`
`34990 and in
`
`paragraphs [0027-0032]
`
`in Japanese Laid-Open Patent Application
`
`Publication JP1999—271501 and the like can be used and the contents of these are
`
`10
`
`15
`
`incorporated herein.
`
`20
`
`[Other Polyisocyanates]
`
`The resin composition may contain polyisocyanates other than m-xylylene diisocyanate as
`
`long as the eyeglass lens of this embodiment has superior ultraviolet absorbency and low
`
`yellowness.
`
`25
`
`The ratio of
`
`the amount of m-xylylene diisocyanate (the total amount when other
`
`polyisocyanates are also present) to the amount of polythiol compound in the resin
`
`composition can be adjusted so that
`
`the ratio of functional
`
`isocyanate groups and
`
`mercapto groups shows an NCO/SH (molar ratio) value of 0.5-3.0 and can be 0.5-1.5
`
`30
`
`[Other Components]
`
`The resin composition used in the present embodiment may contain components other
`
`than those described above as long as the eyeglass lens of the present embodiment has
`
`excellent ultraviolet absorbency and low yellowness. As components other than the
`
`73758191.1
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`16
`
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`

`above,
`
`for example, a preliminary reaction catalyst, a reaction adjustment agent, a
`
`polymerization catalyst, a dye and a pigment, and other additives can be mentioned.
`
`(Polymerization Catalyst)
`
`As a polymerization catalyst,
`
`tin compounds and amines, phosphines, quaternary
`
`ammonium salts, q