Optical article with blue cut, high UV cut and high clarity

Abstract

The combination of selective and high pass filters to cut harmful blue light allowed to achieve the best compromise between high blue cut performance, high UV cut and low yellow index, not achievable when using the filters alone.

Claims

1. A transparent optical article with enhanced ultraviolet and blue light blocking ability comprising: a selective filter at least partially blocking blue light in a wavelength range chosen within the 400-460 nm range; and a high-pass filter having its maximum cut in the UV light wavelength range and partially blocking blue light in the 400-500 nm range; wherein the optical article blocks at least 66% of light with a wavelength less than or equal to about 410 nm, at each wavelength in the wavelength range 350-410 nm; wherein the selective filter is an absorbing dye that has an absorption peak centered at a wavelength chosen within the 410-440 nm wavelength range and exhibits a full width at half maximum lower than or equal to 40 nm.

2. The transparent optical article of claim 1, wherein the absorbing dye is a porphine, a porphyrin, a porphyrin complex or derivative.

3. The transparent optical article of claim 1, wherein the optical article comprises a polymer substrate comprising said absorbing dye dispersed or dissolved within said polymer substrate, at a concentration ranging from 1 to 10 ppm.

4. The transparent optical article of claim 1, wherein the high pass filter is a UV absorber.

5. The transparent optical article of claim 4, wherein the UV absorber is a benzotriazole compound.

6. The transparent optical article of claim 5, wherein the benzotriazole compound is 2-(5-chloro-2H-benzotriazole-2-yl)-6-(1, 1-dimethylethyl)-4-methyl phenol.

7. The transparent optical article of claim 4, wherein the optical article comprises a polymer substrate and, dispersed or dissolved therein, said UV absorber at a concentration ranging from 0.1 to 2.0 weight %.

8. The transparent optical article of claim 1, wherein the optical article has a BVC(B′) value of ≥15%.

9. The transparent optical article of claim 1, wherein the optical article has a colorimetric coefficient b* as defined in the CIE (1976) L*a*b* international colorimetric system that is less than or equal to 5.

10. The transparent optical article of claim 1, wherein the selective filter and high-pass filter reduce the through transmittance of light with a wavelength less than or equal to about 410 nm in a synergistic fashion.

11. A wafer for reducing through-transmittance of light with a wavelength less than or equal to about 410 nm to a substrate, comprising: a blend of a transparent polymer resin; a selective filter at least partially blocking blue light in a wavelength range chosen within the 400-460 nm range; and a high-pass filter having its maximum cut in the UV light wavelength range and partially blocking blue light in the 400-500 nm range; wherein the selective filter is an absorbing dye that has an absorption peak centered at a wavelength chosen within the 410-440 nm wavelength range and exhibits a full width at half maximum lower than or equal to 40 nm.

12. The wafer of claim 11, wherein the wafer reduces through-transmittance of light with a wavelength less than or equal to about 408 nm to a substrate.

13. A process for protecting at least part of an eye of a user from phototoxic blue light, comprising the user obtaining and using an optical article of claim 1.

14. A process of enhancing the blue-cut performance of an optical element resin comprising: blending a transparent polymer resin with a selective filter at least partially blocking blue light in a wavelength range chosen within the 400-460 nm range and a high-pass filter having its maximum cut in the UV light wavelength range; and partially blocking blue light in the 400-500 nm range by a process selected from the group consisting of dry blending, melt mixing, and solvent mixing; wherein the selective filter is an absorbing dye that has an absorption peak centered at a wavelength chosen within the 410-440 nm wavelength range and exhibits a full width at half maximum lower than or equal to 40 nm.

15. The transparent optical article of claim 1, wherein the absorbing dye exhibits a full width at half maximum lower than or equal to 30 nm.

16. The transparent optical article of claim 1, wherein the absorbing dye exhibits a full width at half maximum lower than 25 nm.

17. The transparent optical article of claim 1, wherein the absorbing dye exhibits a full width at half maximum lower than 20 nm.

18. The transparent optical article of claim 1, wherein the absorbing dye exhibits a full width at half maximum higher than or equal to 5 nm.

19. The transparent optical article of claim 1, wherein the absorbing dye exhibits a full width at half maximum higher than or equal to 10 nm.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a graph depicting light transmission through a notch filter and a high pass filter.

(2) FIG. 2 is graph of lens RCAR plotted against YI of two lenses to compare filter efficiency of Tinuvin™326 and ABS420™.

(3) FIG. 3 is graph of lens RCAR plotted against YI of lenses containing Tinuvin™ 326, ABS420™, or a combination of the two.

(4) FIG. 4 is a graph of showing the blue light hazard function B′(λ) (relative spectral efficiency)

DETAILED DESCRIPTION

(5) Various features and advantageous details are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments, are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and/or rearrangements will be apparent to those of ordinary skill in the art from this disclosure.

(6) In the following description, numerous specific details are provided to provide a thorough understanding of the disclosed embodiments. One of ordinary skill in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

(7) In the present disclosure, selective filters and high pass filters are combined to achieve the benefits of both filters, in particular high blue-cut and high UV protection without a significant increase in YI and decrease in % T of the resulting lenses. The selective filter and high pass filter may be incorporated into a lens through filters in wafers or in bulk to provide lenses with both high blue-cut and high UV-cut.

(8) One advantage of the presently disclosed method is that no extra process steps are needed. Both filters may be mixed together and be incorporated into the same wafer or lens.

(9) Blue-cut of a lens is typically defined by:

(10) $\mathrm{Blue}\mathrm{light}\mathrm{cut}\left(\%\right)=100-T_{\mathrm{sb}}$$T_{\mathrm{sb}}=\frac{{\int }_{380\mathrm{nm}}^{500\mathrm{nm}}T\left(\lambda \right).Math.E_{s\lambda }\left(\lambda \right).Math.B\left(\lambda \right).Math.d\lambda }{{\int }_{380\mathrm{nm}}^{500\mathrm{nm}}{E}_{s\lambda }\left(\lambda \right).Math.B\left(\lambda \right).Math.d\lambda }$ where T(λ): Transmittance (%) with 5 nm pitch E.sub.sλ(λ): Solar spectral irradiation (ISO 8980-3: Annex B)

(11) B(λ): Blue light hazard function (ISO 8980-3: Annex B)

(12) The blue-cut performance can be measured according to the following formula

(13) $\mathrm{BVC}\left(B^{\prime }\right)=100\%-\frac{{\int }_{400\mathrm{nm}}^{455\mathrm{nm}}{B}^{\prime }\left(\lambda \right).Math.T\left(\lambda \right).Math.d\lambda }{{\int }_{400\mathrm{nm}}^{455\mathrm{nm}}{B}^{\prime }\left(\lambda \right).Math.d\lambda }$$\mathrm{or}$$\mathrm{BVC}\left(B\right)=100\%-\frac{{\int }_{400\mathrm{nm}}^{455\mathrm{nm}}B\left(\lambda \right).Math.T\left(\lambda \right).Math.d\lambda }{{\int }_{400\mathrm{nm}}^{455\mathrm{nm}}B\left(\lambda \right).Math.d\lambda }$ where T(λ): Transmittance (%) with 5 nm pitch at a given wavelength measured at 0° incidence B(λ): Blue light hazard function (Annex B of ISO 8980-3) B′(λ): Blue light hazard function (Arnault et al., PlosOne, 2013) shown on FIG. 4 (relative spectral function efficiency).

(14) Said light hazard function results from work between Paris Vision Institute and Essilor International.

(15) Table hereafter mentions B′(λ) used in the calculations of BVC(B′):

(16) TABLE-US-00001 Wavelength (nm) Ponderation coefficient B(λ) 400 0.1618 410 0.3263 420 0.8496 430 1.00 440 0.6469 450 0.4237

(17) The blue-cut performance of a lens is a function of the transmittance T(λ), which is directly linked to its color appearance corresponding to a specific transmission spectrum.

(18) Hence, it is important for a lens to have consistent and stable color to achieve constant blue-cut performance. RCAR mainly and BVC(B′) are used herein as a measure of lens blue-cut performance.

(19) The photoprotective potency PP or RCAR (Retinal Cell Apoptosis Reduction) of a lens is determined as the difference between the light-induced apoptosis rate without the filtering of the lens A.sub.NF and the light-induced apoptosis rate with the lens A.sub.F divided by the light-induced apoptosis rate without any lens A.sub.NF:
RCAR(%)=(A.sub.NF−A.sub.F)/A.sub.NF.

(20) RCAR can be measured by in vitro measurements by measuring the effect of the lens equipped with blue filter on the retinal apoptosis A2E-loaded retinal pigment epithelium cells.

(21) This in vitro model that comprises A2E-loaded retinal pigment epithelium cells, is described in details in the paper titled “Phototoxic Action Spectrum on a retinal Pigment Epithelium model of Age-Related macular Degeneration Exposed to Sunlight Normalized Conditions”, by author Arnault, Barrau et al. published on Aug. 23, 2013 in the peer-reviewed scientific Journal PlosOne (availableon plosone.org website).

(22) The in vitro measurements using narrow band light sources or a broadband visible light source are described in European patent application EP16158842.1 filed Mar. 4, 2016 in the name of applicant.

(23) The measurement of RCAR can also be calculated directly from the transmission spectrum of the lens of the invention by using a calculation model correlated with the experimental in vitro results as described in European patent application EP16158842.1

(24) YI The degree of yellowness of the inventive optical article may be quantified by means of colorimetric measurements, based on the CIE tristimulus values X, Y, Z such as described in the standard ASTM E313 with illuminant C observer 2°. The optical article according to the invention preferably has a low yellowness index YI, lower than 5, as measured according to the above standard. The yellowness index Yi is calculated per ASTM method E313 through the relation YI=(127.69 X−105.92 Z))/Y, where X, Y, and Z are the CIE tristimulus values.

EXAMPLES

(25) PC Blue-Cut Lens Preparation

(26) The lens preparation methods described below employed Lexan PC resin supplied by SABIC in combination with one or both of ABS420™ selective filter supplied by Exciton and a Tinuvin™ 326 high-pass filter supplied by BASF. The resin was mixed with different filter concentrations then injection molded into lenses using a BOY injection molding machine. The lens specifications were 1.1 mm plano flat lens with 60 mm diameter.

Example 1 Plano Lenses with ABS420™ Only

(27) Table 1 includes results for lenses that included ABS420™ only. The lens blue-cut performance, determined by the parameter RCAR, correlated with ABS420™ concentration. Lens UV-cut remained constant at 383 nm for the four lens samples, while lens YI increased and T % slightly decreased.

(28) TABLE-US-00002 TABLE 1 Plano Lenses with ABS420 ™ only ABS420 ™ conc. (ppm) BVC (B′) RCAR UV-cut T % YI 0.00 3.9% 6.9% 383 97.3 0.8 1.00 10.8% 18.0% 383 96.9 2.8 1.56 14.2% 22.3% 383 96.7 3.9 1.96 20.6% 25.9% 383 96.6 5.5

Example 2 Plano Lenses with Tinuvin™ 326 Only

(29) Table 2 includes results for lenses that included Tinuvin™ 326 only. Lens blue-cut performance and UV-cut increased with increasing Tinuvin™326 concentration. Lens YI also increased, while T % almost unchanged.

(30) TABLE-US-00003 TABLE 2 Plano Lenses with Tinuvin ™326 only Tinuvin326 conc. (%) BVC (B′) RCAR UV-cut T % YI 0.0 3.9% 6.9% 383 97.3 0.8 0.1 10.9% 11.0% 391 97.3 1.9 0.3 18.3% 15.6% 400 97.1 3.3 0.5 22.8% 18.6% 403 97.1 4.5 1.0 32.5% 25.8% 408 97.0 6.9

(31) FIG. 2 is a graph of RCAR plotted against YI to compare filters' blue-cut efficiencies. A steeper slope corresponds to higher blue-cut efficiency.

(32) Tinuvin™ 326 lenses appear more yellow at the same level of RCAR.

(33) ABS420™ is thus concluded to be more efficient than Tinuvin™ 326 based on RCAR.

Example 3 Plano Lenses with Tinuvin™326 and ABS420™

(34) Table 3 includes results for lenses that included Tinuvin™326 and ABS420™. By mixing ABS420™ with Tinuvin™326, higher blue-cut, i.e., higher RCAR and higher UV-cut were achieved, with negligible impact on T % and YI. The best results were observed for an ABS420™ concentration 1 ppm, and a Tinuvin™326 concentration of 0.3%. Similar results were observed in the examples included in Table 4.

(35) TABLE-US-00004 TABLE 3 Plano Lenses with ABS420 ™ and Tinuvin ™326 ABS420 ™ Tinuvin ™326 conc. (ppm) conc. (%) BVC (B′) RCAR UV-cut T % YI 1.00 0.1 17.4% 20.9% 390 97.0 4.1 1.56 0.1 21.7% 25.7% 390 96.7 5.4 1.00 0.3 24.5% 23.9% 400 96.8 5.4 1.56 0.3 28.0% 27.4% 400 96.6 6.5

(36) In FIG. 3, lens RCAR was plotted against YI for mixed Tinuvin™326 and ABS420™, and compared to those with Tinuvin™326 only and ABS420™ only. Lenses with both Tinuvin™326 and ABS420™ exhibited RCAR values intermediate to single-component lenses but closer to ABS420™

(37) TABLE-US-00005 TABLE 4 Plano Lenses with ABS420 ™ and Tinuvin ™ 326 ABS420 ™ conc. Tinuvin ™326 BVC UV- (ppm) conc.(%) (B′) RCAR cut T % YI 1.00 0 10.8% 18.0% 383 96.9 2.8 1.96 0 20.6% 25.9% 383 96.6 5.5 1.00 0.3 24.5% 23.9% 400 96.8 5.4 0.00 0.3 18.3% 15.6% 400 97.1 3.3 0.00 0.5 22.8% 18.6% 403 97.1 4.5 0.00 1.0 32.5% 25.8% 408 97.0 6.9

Example 4 Powered Lenses with Tinuvin™ 326 and ABS420™

(38) FSV (Finished single vision) −6.00 lenses (72 mm diameter, 1.3 mm CT) were molded either ABS420™, Tinuvin™ 326, or a combination of the two. Lens properties at center were measured and listed in Table 5, for both HMC treated (having a hard coat such as described in example 3 of EP614 and an antireflective coating Crizal Forte) and uncoated lenses. Table 5 shows that lenses made with mixed ABS420™ and Tinuvin™326 exhibit low yellowness at the same RCAR while still maintaining the UV-cut at ˜400 nm (highest UV wavelength).

(39) TABLE-US-00006 TABLE 5 PC Blue-Cut Lens Properties BVC (B′) RCAR UV-cut T % L a* b* FSV-6.00, ABS420 ™ only 16.9% 25.2% 383 96.5 98.6 −0.7 2.8 HMC Tinuvin ™326 only 30.2% 23.7% 408 97.0 98.8 −2.3 5.2 ABS420 ™ + Tinuvin ™326 26.4% 26.2% 399 96.5 98.6 −1.7 4.4 FSV-6.00, ABS420 ™ only 23.1% 31.3% 383 88.5 95.3 −1.2 3.0 UNC Tinuvin ™326 only 37.5% 31.6% 408 88.9 95.5 −2.8 5.7 ABS420 ™ + Tinuvin ™326 33.5% 32.8% 399 88.6 95.4 −2.2 5.0

(40) The lenses of Example 4 were also measured at their edge, and ΔE was calculated using CIE76 equation as shown below to determine color heterogeneity between center and edge. Generally, lower ΔE means less color heterogeneity. Results are shown in Table 6.
ΔE=√{square root over ((ΔL).sup.2+(Δa*).sup.2+(Δb*).sup.2)}

(41) TABLE-US-00007 TABLE 6 ΔE Between Lens Center and Edge ABS420 ™ Tinuvin ™326 ABS420 ™ + only only Tinuvin ™326 FSV-6.00, HMC 13.4 12.4 12.9 FSV-6.00, UNC 13.3 11.9 12.5

(42) Lenses made with mixed ABS420™ and Tinuvin™326 exhibit ΔE values intermediate to lenses with ABS420™ only and Tinuvin™ 326 only.

(43) By mixing ABS420™ together with Tinuvin™ 326 into a PC resin, comparable blue-cut level can be achieved at a loading that is much lower than with either of the two components alone. The resulting lenses exhibit improved UV-cut over using ABS420™ only. At the same blue-cut level, the ABS420™+Tinuvin™ 326 displayed low yellowness without compromising color uniformity, a feature that is important to lens aesthetics.

(44) The claims are not to be interpreted as including means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.