Curable composition for Anti-glare lenses with high refractive index

Abstract

The present invention relates to a curable composition suitable for producing an anti-glare spectacle lens having a high refractive index, an anti-glare spectacle lens having a high refractive index, and a method for producing thereof.

Description

CURABLE COMPOSITION FOR ANTI-GLARE LENSES WITH HIGH REFRACTIVE INDEXSPECIFICATION

[0001] The present invention relates to a curable composition suitable for producing an anti-glare spectacle lens with a high refractive index, an anti-glare spectacle lens with a high refractive index, and a method for producing thereof.

[0002] There has been a rising concern that LED based light sources may cause more glare to drivers and pedestrians. Glare is considered as a severe issue for traffic safety because it increases the detection threshold of objects’ motion nearby and decreases the luminance contrast between objects and their background. The method of glare control is becoming a hot topic as the widespread applications of the LEDs.

[0003] It has been repeatedly reported by the spectacle lens consumers that glare from LED headlights in road traffic, which has the wavelength between 420 nm and 460 nm distorts the sight. Coating spectacle lenses with anti-reflective coatings or optical filter can be one solution, however, currently available anti-reflective coatings turned out to be problematic because of distracting reflex. Adding an optical filter containing dyes developed to provide selective light filtering can be cumbersome and less economical as additional and separate process steps are required. In addition, both of these alternative methods were less economical as significantly large amount of dye, which is extremely expensive, is required for a separate coating layer or an optical filter.

[0004] Under the circumstances, casting spectacle lens materials together with the dyes which can selectively block light with a wavelength between 420 nm and 460 nm was considered as the most economical way of production by the present inventors. However, the development process did not turn out to be smooth. Especially for high refractive index spectacle lenses, it was not possible to obtain spectacle lenses which block light at a target wavelength after being cured together with the conventional dyes used in the coatings or filters. This attributes to monomers or polymerization initiators contained in high refractive index spectacle lenses. When the dyes are cured with the monomers and / or polymerization initiators, the monomers shift the original absorptionpeak of the dyes to a range which is not targeted or a range of no interest or even get rid of the peak. Therefore, it was concluded the conventional dyes developed for a separate coating or an optical filter to provide selective light filtering is not predictable for use as an anti-glare purpose or even cannot be used as they stand when producing lenses by casting and curing. Moreover, said dyes tend to increase the yellowness index in general, and even extensively increase yellowness index when cured. Cured spectacle lens with a high yellowness index is not suitable for an ophthalmic use, and thus significantly limits the usage thereof. As such, it was difficult to provide cured spectacle lenses with a transmission notch peak at a desired peak between 420 nm and 460 nm, without exhibiting too much yellowness at the same time.

[0005] Therefore, there was a need to find a specific dye for blue light absorption which can transmit light at an effective wavelength range for reducing glare even after being cured with high reflective index spectacle lenses, while not significantly increasing yellowness index.

[0006] US 10,605,970 B2 controls light exposure to a visible spectrum range of 400 nm and 700 nm using an optical filter comprising FL-41 tint for the purpose of easing migraines, photophobia light sensitivity by providing a notch peak from 454 nm to 506 nm. However, as noted in the specification of this patent document, said filter does not aim to prevent the LED glare and thus light transmission takes place in a different wavelength range. Further, as admitted in the specification of this patent document, this optical layer has a yellow hue, which is a yellowness that is not acceptable for ophthalmic lenses.

[0007] US 8,360,574 B2 is directed to an ophthalmic lens which comprises a filter that transmits at least 80% of light having a wavelength in the range of 460-700 nm. As evident from the wavelength range, this lens does not aim to reduce glare from LED light. Further, like other prior art documents, a wide range of dyes are disclosed and only the system of polycarbonate glasses which has different polymerization process from polythiourethane and polyepisulfide has been verified. No results of a specific combination of high refractive index lenses and a specific dye have been provided.

[0008] US 7,556,376 B2 relates to a polycarbonate ophthalmic system comprising a film containing a dye that has an 85% or greater scotopic luminous transmission of visible light. Just like US 8,360,574 B2, this patent document is directed to polycarbonate lenses, and thus cannot be applied to high refractive index lenses either.

[0009] EP 3 296 799 A1 discloses a transparent optical article, comprising a selective filter at least partially blocking light in a wavelength range between 400 and 460 nm and a high-pass filter partially blocking blue light in the 400 to 500 nm range. In this patent document, only the polycarbonate lenses were verified to work with this system, meaning that it is unpredictable whether the system will also work in high refractive index lenses such as polythiourethane or polyepisulfide lenses or in cured spectacle lenses.

[0010] US 9,683,102 B2 discloses a selective light wavelength filter comprising a Cu- porphyrin compound as a dye which blocks 5 to 50% of light having a wavelength in the range between 400 and 500nm and transmits at least 80% of light across the visible spectrum. That is, this document is not directed to reducing glare from LED light at the specific wavelength. Further, the ophthalmic system uses spectacle lens materials which are not high refractive index materials, such as polycarbonate or poly allyl diglycol carbonate (CR39). Furthermore, although this document defines the yellowness index to be under a certain value, the working examples do not mention the yellowness of the filter prepared for ophthalmic lenses.

[0011] Starting from US 9,683,102 B2, it is an objective of the present invention to provide a high refractive index spectacle lens which provides a reduced glare from LED light and an acceptable yellowness index for a spectacle lens and blocks harmful UV light.

[0012] The first aspect of the present invention is directed to a curable composition suitable for manufacturing high refractive index spectacle lenses for anti-glare by curing. Through intensive tests and experiments, the present inventors discovered that the specific combination of high refractive index lens materials and a Cu-complex of heterocyclic dye compound as a blue light absorbent can provide a compromise where the glare from LED light is improved by a transmission notch peak at a specificwavelength, and an yellowness index in an acceptable range. The core technical idea of the present invention resides in providing reduced glare from LED light together with a proper balance with yellowness index.

[0013] The curable composition of the present invention comprises a Cu-complex of heterocyclic dye compound a polymeric spectacle lens material which is a polythiourethane spectacle lens material or a polyepisulfide spectacle lens material.

[0014] The terms "polymer" and "polymeric" refer to natural or synthetic substances composed of macromolecules composed of many repeating subunits. They comprise homopolymers and copolymers. The term “polymeric material” as used herein encompasses different polymers of a particular class of material, e.g., the material polythiourethane may consist of a number of chemically distinct polythiourethanes.

[0015] The term “polythiourethane” refers to a class of polymers composed of organic units joined by thiourethane links -S-(C=O)-(NH)-. Polythiourethane is typically produced by reacting a polyisocyanate and a polythiol. In one embodiment, the polythiouretane spectacle lens material of the present invention comprises at least one thiol compound and at least one isocyanate compound.

[0016] The term “polyepisulfide” refers to a group of polymers manufactured by polymerization of monomers that contain at least one episulfide group. In one embodiment, the polyepisulfide spectacle lens material of the present invention comprises at least one thiol compound and at least one episulfide compound.

[0017] The term “thiol compound” refers to a compound that contain at least one thiol group (-SH) in the structure, including monothiol and polythiol. If there are two or more groups in the compound, they can be the same or different.

[0018] The term “isocyanate compound” refers to a compound that contain at least one isocyanate group (-NCO) in the structure, including monoisocyanate and polyisocyanate. If there are two or more groups in the compound, they can be the same or different.

[0019] The term “episulfide compound” refers to a compound that contain at least one episulfide group in the structure, including monoepisulfide and polyepisulfide. If there are two or more groups in the compound, they can be the same or different.

[0020] In one embodiment, the spectacle lens material comprises (i) at least one polythiol compound and at least one polyisocyanate compound or (ii) at least one thiol compound and at least one polyepisulfide compound. The “at least one” compound can be the same or different compounds.

[0021] The term “curable” means that the composition can be cured by UV radiation and / or heat. The curable spectacle lens composition according to the present invention is put into a casting mould and then is cured, typically with the application of heat or radiation, preferably with a thermal cure and a suitable catalysts or initiator known in the art. For the subsequent curing process, the composition may further comprise at least one catalyst or initiator, preferably, a catalyst or an initiator activated by heat and / or light (UV, visible light, infrared, etc.). The curable composition according to the present invention may further comprise free radically polymerizable diluents, for example but not limited thereto, vinyl, allylic monomers or oligomers, etc.

[0022] The term “spectacle lens” refers to an ophthalmic lens worn in front of, but not in contact with, the eyeball (ISO 13666:2019(E), section 3.5.2), where ophthalmic lens is a lens intended to be used for purposes of measurement, correction and / or protection of the eye, or for changing its appearance (ISO 13666:2019(E), section 3.5.1 ). Here, a spectacle lens includes, but not limited thereto, a corrective lens, protective lens, absorptive lens, clear lens, tinted lens, uniformly tinted lens, gradient tinted lens, double gradient-tinted lens, photochromic lens, polarizing lens, balancing lens, matching lens, etc. as defined in Section 3.5.3 to 3.5.13 of DIN ISO 13666:2019. Further, according to Section 3.6 of DIN ISO 13666:2019, a spectacle lens can have various lens shapes including, but not limited thereto, curved-form lens, piano lens, spherical lens, cylindrical lens, spherocylindrical lens, toric lens, aspheric lens, atoric lens, etc. The term “spectacle lens material” refers to any material suitable for manufacturing the spectacle lens, including monomers / oligomers / compounds used for manufacturing the spectacle lens.

[0023] The spectacle lens material is the optical material defined according to section 3.3.1 of DIN EN ISO 13666:2019-12 as transparent material capable of being manufactured into optical components. The spectacle lens material may be made of a thermosetting hard resin according to section 3.3.3 of DIN EN ISO 13666:2019-12. High refractive index spectacle lens material may comprise thiol compound, isocyanate compound and / or episulfide compound, and in a preferred embodiment can be polythiourethane or polyepisulfide. The term “high refractive index” according to the present invention refers to a refractive index 1.59 or higher, preferably between 1.59 and 1.76, more preferably between 1.59 and 1.80.

[0024] Various blue light absorbers having an absorption peak at a range of 400 nm to 460 nm have been widely used for blocking blue light. The examples are azo dye, aryl dye (e.g., auramine O), hydrocarbon dye (e.g., lutein, zeaxanthin), aromatic dye (e.g., coumarin 343, coumarin 314), and heterocyclic dye, etc.

[0025] The present inventors discovered through intensive testing and experiments that among the broad spectrum of blue light absorbers, heterocyclic dye compounds; among the heterocyclic dye compounds, the metal complexes thereof; and among the metal complexes of heterocyclic dye compounds, copper complexes can provide sufficient blocking of the light in an effective range to reduce glare in high refractive index spectacle lenses produced by curing with a yellow index suitable for spectacle lenses.

[0026] Finding a balance between the wavelength range and the blue light amount effective to be blocked to enable reduction of LED glare has been difficult. This is even more unpredictable as the monomers and / or initiators and / or catalysts of high refractive index spectacle lens materials significantly shift and distort or even get rid of the original absorption peak of blue light absorbents after curing. Further, blocking and / or inhibiting blue light affects color balance and color vision, i.e. , yellowness index of spectacle lenses.

[0027] Specifically, one common technique for blue light blocking involves tinting or dyeing lenses with blue light absorbers. These absorbers have a yellow or even a red color and thus impart a yellow or amber tint to the lenses. The tint thus may interferewith the normal color perception of a spectacle lens user, making it difficult, for example, to correctly perceive the color of a traffic light or sign, thereby making the spectacle lenses produced therefrom useless. Further, improper combination of a blue light absorber and a spectacle lens material may lead to unwanted and undesirable reduction of the overall transmission of light wavelengths other than blue light wavelengths. This unwanted reduction may in turn result in reduced visual acuity for a lens user. The present invention overcame the above difficulties and discovered that Cu-complex of heterocyclic dye compounds can block a wavelength range from 420 nm to 440 nm, preferably 422 nm to 438 nm, which is effective for reducing glare from LED light, even after curing, without significantly harming the yellowness. It was found that a wavelength lower than said range will not be effective for anti-glare from LED light, while a wavelength higher than said range will result in too high yellowness index. Therefore, a wavelength range from 420 nm to 440 nm, preferably 422 nm to 438 nm, needs to be blocked to provide anti-glare from LED light.

[0028] Heterocyclic dye compound according to the present invention is a dye compound with one or more heterocycle. A heterocycle is a compound that has atoms of at least two different elements as members of its ring(s). In general, the first element is carbon, and the other elements can be selected from the group consisting of oxygen, nitrogen, sulfur, phosphor, etc. Other than this, a chemical nature of heterocyclic dye compounds that may act as a means for at least partially inhibiting light having a wavelength ranging from 420 nm to 440 nm, preferably 422 nm to 438 nm, is not particularly limited, provided that it shows a maximum absorption peak, within the 420 nm to 440 nm, preferably the 422 nm to 438 nm range after being cured together with a high refractive index spectacle lens material.

[0029] Heterocyclic compound may be a coordination complex or may be a noncoordination complex. When a central atom or ion is metallic, it is a metal complex. A metal complex is a coordination complex which is a chemical compound consisting of a central atom or ion which is metallic and is bonded to one or more ligands, which are ions or molecules that contain one or more pair of electrons that can be shared with the metal. Generally, the metal can be selected from the group consisting of Cu, Ni, V, Or, Ag, In, Mn, Sn, Fe, Co, Mg, Pt, Pd, Ru, and Zn, etc. Among the unduly broad scope of metal complexes, the present inventors found that Cu-complex of heterocyclic dyecompound is suitable for curable anti-glare spectacle lens composition, while other metal complexes cannot achieve the anti-glare function along with the proper yellowness.

[0030] Comparable to an antireflective coating or an optical filter comprising a Cu- complex of heterocyclic dye compound, the present composition enables sufficient blocking of light in a wavelength range effective for reducing glare from LED light even with a minimal amount of a Cu-complex of heterocyclic dye compound. This is cost effective and also advantageous in terms of yellowness index of spectacle lenses. This was possible by selecting a casting and curing method for preparing an anti-glare spectacle lens, and casting and curing a spectacle lens material together with a Cu- complex of heterocyclic dye compound being dissolved in the spectacle lens material. For instance, the optical filter of US 9,683,102 B2 comprises a Cu-complex of heterocyclic dye compound at a concentration of 1 % by weight dye / primer of the optical filter to obtain the desired effect. On the contrary, the present curable composition contains only a minimal concentration of a Cu-complex of heterocyclic dye compound. In one embodiment, the amount of the Cu-complex of heterocyclic dye compound in the present composition is 0.1 to 10 ppm, i.e., 0.00001 to 0.001 % by weight of the entire composition. In another embodiment, the amount of the Cu-complex of heterocyclic dye compound in the present composition is 0.5 to 3 ppm, i.e., 0.00005 to 0.0003% by weight of the entire composition.

[0031] In addition, it is necessary to block ultraviolet light to remove the harmful influence on the eye of a wearer of the lens. For the ultraviolet bands, UVB wavelengths are from 290 nm to 320 nm, and UVA wavelengths are from 320 nm to 400 nm. In light of this, the present composition aims to prepare an anti-glare spectacle lens which substantially blocks light having a wavelength shorter than 400 nm, preferably from 290 nm to 400 nm, as well as has an absorption notch peak between 420 nm and 440 nm, preferably between 422 nm and 438 nm.

[0032] For this purpose, the composition further comprises a UV absorber that has the ability to at least partially block light having a wavelength shorter than 400 nm. Any known UV absorbers having said ability can be used, including benzotriazole derivatives. It was found that benzotriazole and / or benzophenone UV absorbers exhibitthe most desirable properties as a spectacle lens when cured in combination with a high index refractive spectacle lens material and a Cu-complex heterocyclic dye compound. In one embodiment, the UV absorber comprises a benzotriazole and / or benzophenone compound.

[0033] In one embodiment, an amount of a UV absorber may be 3% by weight or less, preferably 2% by weight or less of the entire composition.

[0034] In an optional embodiment, a bluing agent can be used to further lower the yellowness of the spectacle lens for cosmetic reasons. For this purpose, the present composition may comprise a bluing agent. A bluing agent is a compound having an absorption band in the visible light spectrum in the orange to yellow wavelength region with a color from blue to violet. Any conventional bluing agent known to be suitable for optical use can be used.

[0035] The second aspect of the present invention is a spectacle lens prepared by curing the curable composition of the present invention described with respect to the first aspect. All features explained with regard to the first aspect apply to the second aspect unless specifically described otherwise. The present spectacle lens is an antiglare spectacle lens which is a polythiourethane spectacle lens or a polyepisulfide spectacle lens and comprises a Cu-complex of heterocyclic dye compound.

[0036] The present spectacle lens prepared by casting and curing the present curable composition has a light absorption notch peak at 430 ± 10 nm, preferably at 430 ± 8 nm. In a further embodiment, the spectacle lens has a light transmittance at the light absorption notch peak from 80% to 20%, from 70% to 30%, or 70% to 40%, or 70% to 50%.

[0037] The spectacle lens further comprises a UV absorber, thereby blocks the harmful ultra-violet light of 400nm or below, or preferably from 290 nm to 400 nm. The spectacle lens according to the present invention blocks the light of 400 nm or below, preferably from 290 nm to 400 nm. In one embodiment, the spectacle lens blocks at least 90%, or at least 95%, or at least 98% of light with a wavelength of 400 nm or below, preferably from 290 nm to 400 nm.

[0038] This is also a unique feature of the present spectacle lens. On the contrary, for example, the optical article of EP 3 296 799 A1 blocks at least 66% of light with a wavelength less than or equal to about 410 nm, at each wavelength in the wavelength range between 350 and 410 nm. As the light blockage at 400nm of the present spectacle lens is nearly 100% and there is an absorption notch peak at between 420 nm and 440 nm which is from 20% to 80%, a light blockage at around 410 nm of the present spectacle lens is estimated to be lower than 60%.

[0039] In a further embodiment, at a wavelength of 450 nm, the present spectacle lens shows a light transmission of 80% or greater. This reflects low yellowness and high transparency of the spectacle lens, which are suitable for ophthalmic use.

[0040] The anti-glare spectacle lens of the present invention can be further defined as an anti-glare spectacle lens having a yellowness index (Yl) of 9 or less, preferably 8 or less, more preferably 7 or less. The yellowness index in the present invention is measured according to ASTM D1925.

[0041] Besides yellowness index, the anti-glare spectacle lens of the present invention can be characterized by the subjective perception of the color shown by CIE LAB color space, also referred to as L*a*b*, is a color space defined by CIE and expresses color as three values, L* for perceptual lightness and a* and b* for the four unique colors of human vision: red, green, blue and yellow. The lightness value, L* defines black at 0 and white at 100. The a* axis is relative to the green-red opponent colors, with negative values toward green and positive values toward red. The b* axis represents the blueyellow opponents, with negative numbers toward blue and positive toward yellow. The present invention calculated CIELAB using CIE Standard illuminant D65.

[0042] In one embodiment, the present spectacle lens has a color defined in CIE L*a*b* space by the parameters -4 < a* < -1 , 3 < b* < 5 and 90 < L*< 100.

[0043] In a further embodiment, the present spectacle lens comprises a hard coating and / or an antireflective coating. Light transmittance can be further influenced by the subsequent application of such coatings. The spectacle lens which comprises a hardcoating and / or an antireflective coating has a yellowness index of 12 or less, or 11 or less, or 10 or less. Further, the spectacle lens which comprises a hard coating and / or an antireflective coating has a light transmittance of 90% or greater at a wavelength 450 nm. This shows that the present spectacle lens has a proper yellowness index suitable for an optical use.

[0044] A third aspect of the present invention relates to a method configured to produce an anti-glare spectacle lens according to the second aspect of the present invention by curing a curable composition according to the first aspect of the present invention. All features explained with regard to the first and second aspects apply to the third aspect unless specifically described otherwise.

[0045] The present method comprises preparing a curable composition by mixing a polythiourethane spectacle lens material and / or polyepisulfide spectacle lens material and a Cu-complex of heterocyclic dye compound; and curing the curable composition.

[0046] In one embodiment, the spectacle lens material comprises (i) at least one thiol compound and at least one isocyanate compound or (ii) at least one thiol compound and at least one episulfide compound.

[0047] In one embodiment, the present method comprises mixing the spectacle lens material, the Cu-complex of heterocyclic dye compound, and a UV absorber.

[0048] In an optional embodiment, the present method comprises mixing the spectacle lens material, the Cu-complex of heterocyclic dye compound, a UV absorber, and a bluing agent.

[0049] In one embodiment, the present method further comprises applying a hard coating and / or an antireflective coating to a surface of the cured spectacle lens.BRIEF DESCRIPTION OF DRAWINGS

[0050] Embodiments of the present invention will be described based on FIGS. 1 to 14.

[0051] FIG. 1 shows a transmittance graph of the uncoated spectacle lens prepared according to Example 1 .

[0052] FIG. 2 shows a transmittance graph of the coated spectacle lens prepared according to Example 1 .

[0053] FIG. 3 shows a transmittance graph of the uncoated spectacle lens prepared according to Example 2.

[0054] FIG. 4 shows a transmittance graph of the coated spectacle lens prepared according to Example 2.

[0055] FIG. 5 shows a transmittance graph of the uncoated spectacle lens prepared according to Example 3.

[0056] FIG. 6 shows transmittance graph comparison of the uncoated spectacle lens prepared according to Example 4 and Example 5, respectively.

[0057] FIG. 7 shows transmittance graph comparison of the uncoated spectacle lens prepared according to Example 6 and Example 7, respectively.

[0058] FIG. 8 shows transmittance graph comparison of the uncoated spectacle lens prepared according to Example 8 and Example 9, respectively.

[0059] FIG. 9 shows the transmittance graph of the uncoated spectacle lens prepared according to Example 10.

[0060] FIG. 10 shows a transmittance graph of the coated spectacle lens prepared according to Example 10.

[0061] FIG. 11 shows the transmittance graph of the uncoated spectacle lens prepared according to Comparison Example 1.

[0062] FIG. 12 shows the transmittance of the Cu-complex of heterocyclic dye compound depending on its concentration.

[0063] FIG. 13 shows the transmittance graph of the uncoated spectacle lens prepared according to Comparison Example 5.

[0064] FIG. 14 shows the transmittance graph of the uncoated spectacle lens prepared according to Comparison Example 6.EXAMPLES

[0065] Hereinafter, the embodiments of the present invention will be described in further detail. It should be understood, however, that the following examples are only for illustrative purposes and do not in any way restrict the present invention.EXAMPLE 1

[0066] The monomers / oligomers of the polythiourethane spectacle lens material (MR8, Mitsui Chemicals) were mixed with 2 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). FDB-001 has been reported to be red and have the absorption peak (Amax) at 420 nm. A conventional benzotriazole UV absorber of 0.77 % by weight was added. The mixture was filled into the spectacle lens moulds and then cured by heat in a curing oven. A spectacle lens with a 2.0 mm thickness and a refractive index of 1 .60 was obtained.

[0067] As shown in FIG. 1 , transmittance at 400 nm or lower was lower than 2%, indicating that harmful UV light is almost completely blocked by the UV absorber. An absorption notch peak at about 426 nm, showing 53% of transmittance was observed due to FDB-001. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 6 nm, to an extent which is still within the effective range for anti-glare effect, and thus despite the shift, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 85.78% for an uncoated sample showing that low yellowness and high transparency have been achieved.

[0068] The produced spectacle lens has a yellowness index of 5.52 and a haze of 0.23%, which are within a suitable range to be used as a spectacle lens.

[0069] Subsequently, the cured spectacle lens was coated with a hard coating (CrystalCoat ® IM-9060) and an antireflective coating (DuraVision Platinum (DVP), Zeiss). As shown in FIG. 2, the coated lens was still able to reduce glare from LED light, showing an absorption notch peak at 426 nm, showing 58% of transmittance. Meanwhile the yellowness index increased to 7.41 , presumably due to the AR coating and the haze decreased to 0.11 %, presumably due to the cleaning process before the coating process. The transmittance at a wavelength of 450 nm increased to 94 %.Example 2

[0070] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 2 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was casted into the spectacle lens moulds and then cured thermally in a curing oven. A spectacle lens with a 2 mm thickness and a refractive index of 1 .67 was obtained.

[0071] As shown in FIG. 3, transmittance at 400 nm or lower was 2% or less, indicating that harmful UV light is nearly all blocked. An absorption notch peak at about 428 nm, showing 52% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 8 nm, to an extent which is still within the effective range for anti-glare effect, and thus despite the shift, glare from LED light can be successfully reduced. The transmittance at a wavelength of 450 nm was 84%.

[0072] The produced spectacle lens has a yellowness index of 6.14 and a haze of 0.16%, which are within a suitable range to be used as a spectacle lens.

[0073] Subsequently, the cured spectacle lens was coated with a hard coating (CrystalCoat ® IM-9060) and an antireflective coating (DuraVision Platinum (DVP), Zeiss). As shown in FIG. 4, the coated lens was still able to reduce glare from LED light, showing a notch peak at 428 nm, showing 57% of transmittance. Meanwhile, the yellowness index increased to 8.79 and the haze decreased to 0.04%. The transmittance at a wavelength of 450 nm increased to 92%.Example 3

[0074] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 1 .5 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was casted into the spectacle lens moulds and then cured thermally in a curing oven. A spectacle lens with a 2 mm thickness and a refractive index of 1 .67 was obtained.

[0075] As shown in FIG. 5, transmittance at 400 nm or lower was 2% or lower, indicating that harmful UV light is nearly completely blocked. An absorption notch peak at about 428 nm, showing 65% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 8 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite the shift, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 85%.

[0076] The produced spectacle lens has a yellowness index of 6.08 and a haze of 0.55%, which are within a suitable range to be used as a spectacle lens.Example 4

[0077] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 1 .5 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was casted into the spectacle lens mouldsand then thermally cured in a curing oven and went through polymerization. A spectacle lens with a 2.03 mm thickness and a refractive index of 1 .67 was prepared.

[0078] The transmittance at 400 nm or lower was 2% or lower, indicating that harmful UV light is nearly completely blocked. An absorption notch peak at about 428 nm, showing 59% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 8 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 85%.

[0079] The produced spectacle lens has a yellowness index of 6.36 and a haze of 0.18%, which are within a suitable range to be used as a spectacle lens.Example 5

[0080] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 1 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was casted into spectacle lens moulds and then cured in a curing oven and went through polymerization. A spectacle lens with a 2 mm thickness and a refractive index of 1 .67 was obtained.

[0081] The transmittance at 400 nm or lower was 2%, indicating that harmful UV light is nearly completely blocked. An absorption notch peak at about 428 nm, showing 66% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 8 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 85%.

[0082] The produced spectacle lens has a yellowness index of 5.27 and a haze of 0.23%, which are within a suitable range to be used as a spectacle lens.

[0083] The transmittance curve of Example 4 and Example 5 are compared in FIG. 6. It is noted that increased amount of the Cu-complex of heterocyclic dye compound in Example 4 allows to block more light at the target wavelength, thereby leading to improved anti-glare effect. On the other hand, the yellowness index was higher in Example 4 compared to Example 5, where more dye was used. This clearly shows the difficulties in finding appropriate amount of the Cu-complex of heterocyclic dye compound which can achieve the balance between the anti-glare effect and yellowness index suitable for spectacle lenses.Example 6

[0084] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 1 .5 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was casted into the spectacle lens moulds and then thermally cured in a curing oven and went through polymerization. A spectacle lens with a 2 mm thickness and a refractive index of 1 .67 was obtained.

[0085] The transmittance at 400 nm or lower was 2% or lower, indicating that harmful UV light is completely blocked. An absorption notch peak at about 428 nm, showing 59% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 8 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 85%.

[0086] The produced spectacle lens has a yellowness index of 6.68 and a haze of 0.23%, which are within a suitable range to be used as a spectacle lens.Example 7

[0087] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 1 .0 ppm Cu-complex of heterocyclic dye compound(FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The monomer mixture was filled into the spectacle lens moulds and then thermally cured in a curing oven and went through polymerization. A spectacle lens with a 2.01 mm thickness and a refractive index of 1 .67 was prepared.

[0088] The transmittance at 400 nm or lower was 2% or less, indicating that harmful UV light is nearly completely blocked. An absorption notch peak at about 428 nm, showing 65% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 8 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 85%.

[0089] The produced spectacle lens has a yellowness index of 5.73 and a haze of 0.63%, which are within a suitable range to be used as a spectacle lens.

[0090] The transmittance curve of Example 6 and Example 7 are compared in FIG. 7. It is noted that increased amount of Cu-complex of heterocyclic dye compound in Example 6 allows to block more light at the target wavelength, thereby leading to improved anti-glare effect. On the other hand, the yellowness index was higher in Example 6 compared to Example 7, in which more dye was used. This clearly shows that it is difficult to find the amount of the Cu-complex of heterocyclic dye compound which can achieve the balance between the anti-glare effect and yellowness index suitable for spectacle lenses.Example 8

[0091] The monomers / oligomers of the polythiourethane spectacle lens material (MR8, Mitsui Chemicals) were mixed with 1 .5 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.77 % by weight was added. The mixture was filled into the spectacle lens moulds and then thermally cured in a curing oven and went through polymerization. A spectacle lens with a 2.01 mm thickness and a refractive index of 1 .60 was prepared.

[0092] The transmittance at 400 nm or lower was 2% or lower, indicating that harmful UV light is completely blocked. An absorption notch peak at about 426 nm, showing 58% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 6 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 87%.

[0093] The produced spectacle lens has a yellowness index of 5.76 and a haze of 0.17%, which are within a suitable range to be used as a spectacle lens.Example 9

[0094] The monomers / oligomers of the polythiourethane spectacle lens material (MR8, Mitsui Chemicals) were mixed with 1 .0 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.77 % by weight was added. The mixture was filled into the spectacle lens moulds and then thermally cured in a curing oven and went through polymerization. A spectacle lens with a 2.01 mm thickness and a refractive index of 1 .60 was obtained.

[0095] The transmittance at 400 nm or lower was 2%, indicating that harmful UV light is almost completely blocked. An absorption notch peak at about 426 nm, showing 66.5% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polythiourethane shifted the peak of the Cu-complex of heterocyclic dye compound about 6 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 88%.

[0096] The produced spectacle lens has a yellowness index of 4.38 and a haze of 0.28%, which are within a suitable range to be used as a spectacle lens.

[0097] The transmission curve of Example 8 and Example 9 are compared in FIG. 8. It is noted that increased amount of Cu-complex of heterocyclic dye compound inExample 8 allows to block more light at the target wavelength, thereby leading to improved anti-glare effect. On the other hand, the yellowness index was higher in Example 8 compared to Example 9, in which more dye (FDB-001 ) was used. This clearly shows difficulties in finding the amount of the Cu-complex of heterocyclic dye compound which can achieve the balance between the anti-glare effect and yellowness index suitable for spectacle lenses.Example 10

[0098] The monomers / oligomers of the polyepisulfide spectacle lens material (MR174, Mitsui Chemicals) were mixed with 1 .5 ppm Cu-complex of heterocyclic dye compound (FDB-001 , Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 1.35 % by weight was added. The mixture was filled into the spectacle lens moulds after degassing and then thermally cured in a curing oven. A spectacle lens with a 2.02 mm thickness and a refractive index of 1 .74 was obtained.

[0099] As shown in FIG. 9, the transmittance at 400 nm or lower was 2% or lower, indicating that harmful UV light is almost blocked. An absorption notch peak at about 432 nm, showing 56% of transmittance was observed. This shows that the monomers / oligomers and / or polymerization process of polyepisulfide shifted the peak of the Cu-complex of heterocyclic dye compound about 12 nm, to an extent which is still within the effective range for anti-glare effect. Therefore, despite this, glare from LED light has been successfully reduced. The transmittance at a wavelength of 450 nm was 82.48%.

[0100] The produced spectacle lens has a yellowness index of 7.23 and a haze of 0.15%, which are within a suitable range to be used as a spectacle lens.

[0101] Subsequently, the cured spectacle lens was coated with a hard coating (CrystalCoat ® IM-9060) and an antireflective coating (DuraVision Platinum (DVP), Zeiss). As shown in FIG. 10, the coated lens was still able to reduce glare from LED light, showing an absorption notch peak at 432 nm, showing 64% of transmittance. Meanwhile the yellowness index increased to 7.41 , presumably due to the AR coatingand the haze decreased to 0.11 %, presumably due to the cleaning process before the coating process. The transmittance at a wavelength of 450 nm increased to 94 %.

[0102] The experimental results are summarized in Table 1 below.Table 1 . Experimental resultsComparative Example 1

[0103] The monomers / oligomers of the poly allyl diglycol carbonate spectacle lens material (CR39) were mixed with 1 ppm Cu-complex of heterocyclic dye compound(FDB-001 , Yamada Chemical Co., Ltd.). The monomers / oligomers were mixed with a peroxide free radical initiator for polymerization. A conventional benzophenone type UV absorber of 0.085 % by weight was added. Despite the presence of the Cu-complex of heterocyclic dye compound, FDB-001 , no absorption notch peak was observed in the transmission curve shown in FIG. 11 for the liquid monomer in a liquid cell. No absorption notch peak was observed in the transmittance curve as shown in FIG. 11 for the liquid monomer in a liquid cell.

[0104] After degassing, the mixture was then casted into the spectacle lens moulds and subsequently cured by thermal polymerization initiated by the peroxide free radical initiator. A spectacle lens with a 2.21 mm thickness and a refractive index of 1.498, which is a relatively lower refractive index compared to Examples 1 to 10, was obtained.

[0105] After the curing, despite the presence of the Cu-complex of heterocyclic dye compound, FDB-001 , again, no absorption notch peak was observed in the transmission curve as shown in FIG. 11. This spectacle lens was not able to reduce the glare from the LED light. It is presumed that the dye compound failed to stay intact while being mixed with the poly ally diglycol carbonate spectacle lens material.Comparative Example 2

[0106] Instead of the Cu-complex of heterocyclic dye compound used in the examples, a dye which is not a heterocyclic dye compound was used for various combinations of curable composition to verify the significant role of Cu-complex of heterocyclic dye compound.

[0107] FDB-004, a solvent dye from Yamada Chemical Co., Ltd. was selected. FDB- 004 is reported to be yellow and have the absorption peak (Amax) at 445 nm. The effective amount of FDB-004 was tested. As shown in FIG. 12, it was found that FDB- 004 provides effective light blocking when used in an amount of 6 ppm or greater. Therefore, 6 ppm was selected for the standard amount in the relevant comparative examples.

[0108] The monomers / oligomers of the poly allyl diglycol carbonate spectacle lens material (RAV7AX) was mixed with 6 ppm FDB-004. A conventional benzophenone type UV absorber of 0.085 % by weight was added. The mixture was casted into spectacle lens moulds and then thermally cured in a curing oven and went through polymerization initiated by a peroxide initiator. A relatively lower refractive index spectacle lens with a refractive index of 1 .51 was obtained.

[0109] Although the absorption notch peak in the monomer liquid mix was observed, after curing, this absorption notch peak disappeared. It suggests that that the dye compound has been destroyed during the polymerization of poly ally diglycol carbonate spectacle lens material.Comparative Example 3

[0110] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 6 ppm FDB-004. A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was filled into the spectacle lens moulds after degassing and then cured thermally in a curing oven and went through polymerization. A high refractive index spectacle lens with a refractive index of 1 .67 was obtained.

[0111] An absorption notch peak at about 460 nm, showing 57% of transmittance was observed. This shows that the monomers / oligomers of polythiourethane shifted the peak of the non-heterocyclic dye compound about 15 nm, resulting in the notch peak outside the effective range for anti-glare effect. As it transmits light at 460 nm, the thus- prepared spectacle lens looked very yellow. It was not acceptable as a clear spectacle lens with a good quality.Comparative Example 4

[0112] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 6 ppm FDB-004. A conventional benzotriazole UV absorber of 0.51 % by weight was added. After degassing, the mixture was filled into the spectacle lens moulds and then thermally cured in a curing oven and went throughpolymerization. A high refractive index spectacle lens with a refractive index of 1 .67 was obtained.

[0113] An absorption notch peak at about 460 nm, showing 57% of transmittance was observed. This shows that the monomers / oligomers of polythiourethane shifted the peak of the non-heterocyclic dye compound about 15 nm, resulting in the notch peak outside the effective range for anti-glare effect. Since 460 nm is a very long wavelength, the lens appears very yellow.Comparative Example 5

[0114] Instead of the Cu-complex of heterocyclic dye compound dye used in the above examples and comparative examples, heterocyclic dye compound complex with a different metal was used to verify the significant role of Cu-complex dye.

[0115] FDB-002, Vanadium-complex dye from Yamada Chemical Co., Ltd. was selected. FDB-002 is reported to be red just like FDB-001 and have the absorption peak (A max ) at 431 nm.

[0116] The monomers / oligomers of the polythiourethane spectacle lens material (MR7, Mitsui Chemicals) were mixed with 2 ppm V-porphyrin dye (FDB-002, Yamada Chemical Co., Ltd.). A conventional benzotriazole UV absorber of 0.51 % by weight was added. The mixture was filled into the spectacle lens moulds and then thermally cured in a curing oven and went through polymerization. A spectacle lens with a refractive index of 1 .67 was obtained.

[0117] As shown in FIG. 13, transmittance at 400 nm or lower was 2% or lower, indicating that harmful UV light is almost blocked. An absorption notch peak at about 440 nm, showing 57% of transmittance was observed. This shows that the monomers of polythiourethane shifted the peak of V-complex dye compound about 9 nm, resulting in the notch peak outside the effective range for anti-glare effect. Due to this shift, the absorption notch dye peak causes the spectacle lens to be too yellow.

[0118] As such, the produced spectacle lens has a yellowness index of 12.5, which is not suitable for a use as a spectacle lens.

[0119] Given this, it is clear that the combination of a high refractive spectacle lens material and a heterocyclic dye compound of which the coordinating metal is not Cu results in unacceptable yellowness index for spectacle lenses.Comparative Example 6

[0120] The monomers / oligomers of the poly allyl diglycol carbonate spectacle lens material (CR39) were mixed with 1.25 ppm V-porphyrin dye (FDB-004) and peroxide as a catalyst for polymerization. A conventional benzophenone type UV absorber of 0.085% by weight was added. As shown in FIG. 14, an absorption notch peak was observed at 430 nm showing 70% of transmittance in liquid form before curing, using 2 mm thick liquid cell.

[0121] The mixture was then filled into spectacle lens the moulds and then cured by thermal curing in a curing oven and went through polymerization. A low refractive index spectacle lens with a refractive index of 1 .498 was obtained. However, after curing, the absorption notch peak at 430 nm disappeared as can be confirmed from FIG. 14. It is clear that the combination of a low refractive spectacle lens material with a peroxide and V-complex of dye compound cannot reduce the glare from LED light.

Claims

CLAIMS1. A curable composition suitable for producing an anti-glare spectacle lens characterized by comprising: a Cu-complex of a heterocyclic dye compound, and a polythiourethane spectacle lens material and / or a polyepisulfide spectacle lens material.

2. The curable composition according to claim 1 , characterized in that the polythiourethane spectacle lens comprises at least one thiol compound and at least one isocyanate compound.

3. The curable composition according to claim 1 , characterized in that the polyepisulfide spectacle lens material comprises at least one thiol compound and at least one episulfide compound.

4. The composition according to any one of the preceding claims, characterized in that the anti-glare spectacle lens has a refractive index of 1.59 or higher.

5. The composition according to any one of the preceding claims, characterized in that an amount of the Cu-complex of the heterocyclic dye compound is 0.1 to 10 ppm or 0.5 to 3 ppm.

6. The composition according to any one of the preceding claims, characterized in that the composition has a light absorption notch peak at 430 ± 10 nm or at 430 ± 8 nm.

7. An anti-glare spectacle lens prepared by curing the curable casting composition according to any one of the preceding claims, characterized in that a light transmittance at the light absorption notch peak is from 80% to 20%, from 70% to 30%, or 70% to 40%, or 70% to 50%.

8. The anti-glare spectacle lens according to claim 7,characterized in that the anti-glare spectacle lens is a polythiourethane spectacle lens or a polyepisulfide spectacle lens.

9. The anti-glare spectacle lens according to claim 7 or 8, characterized in that the anti-glare spectacle lens has a high refractive index of 1 .59 or higher.

10. The anti-glare spectacle lens according to any one of claims 7 to 9, characterized by blocking at least 90%, or at least 95%, or at least 98% of light with a wavelength of 400 nm or below, or with a wavelength from 290 nm to 400 nm.11 . The anti-glare spectacle lens according to any one of claims 7 or 10, characterized by having a yellowness index (Yl) of 9 or less, or 8 or less, or 7 or less.

12. The anti-glare spectacle lens according to any one of claims 7 to 11 , characterized by having a light transmittance rate (%) greater than 80% at a wavelength of 450 nm.

13. The anti-glare spectacle lens according to any one of claims 7 to 12, characterized by blocking lower than 60% of light at a wavelength of 410 nm.

14. A method suitable for producing the anti-glare spectacle lens according to any one of claims 7 to 13 comprising, casting molding or injection molding the curable composition according to any one of claims 1 to 6, and curing the composition.

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