AU685696B2 - A photochromic light-transmissible article - Google Patents

Description

rr_ I WO 96/18927 PCT/AU95/00845 A Photochromic Light-transmissible Article The present invention relates to light-transmissible articles including optical articles for example sunglass spectacle lenses and skylights. The present invention relates in particular to photochromic light-transmissible articles.

It is known in the prior art that photochromic articles change colour when exposed to light, primarily the ultraviolet. This feature is employed in a number of applications such as information storage, counterfeiting treatments, cosmetics and optical articles such as lenses and transparent glazings or windows. The depth of coloration by a photochromic article such as a spectacle lens or a transparent glazing diminishes as the temperature of the material that hosts the photochromic media increases. This is more evident with organic photochromic dyes rendered in a polymeric host than with inorganic silver based compositions such as are commonly incorporated within glass (Figures 1 and In addition to the reduction in depth of darkening, there is frequently a change in the colour observed when the photochromic species, in particular a mixture of photochromic species, are activated by incident UV light (Figure 3) In the case of plastic spectacle lenses, sunglass lenses or automotive skylights, the temperature reached by the lens or glazing when exposed to strong summer sunlight may be such that there is virtually no darkening effect observable. It has been found that cooling these photochromic articles by means such as wetting with water at ambient temperature restores much of the coloration, as the absorption of near infrared radiation by the optical plastic results in its being heated as much as 15 to 200C above the temperature of the surrounding air.

A range of methods are known throughout industry for controlling the temperature of objects which are exposed to infra-red radiation without directly cooling them, or conversely for preventing them from losing heat by radiating energy. A familiar example of these is the double walled vacuum vessel, or dewar, used for storage of hot or cold liquids. The surfaces opposing the vacuum cavity in these vessels are coated with a reflecting mirror which prevents visible and infra-red radiation from passing through the walls.

Double glazing of windows is used in many parts of the world to conserve

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-I I sl WO 96/18927 PL-TIAU95100845 -2energy when a significant temperature differential exists betwveen indoors and outdoors. This reduces the energy transfer to be achieved by either air conditioning in summer or heating in winter. An alternative technology is to apply specialised multiple layer optical coatings to the surfaces of the glass panes that constitute the glazing so that the surfaces are able to reflect near infrared radiation selectively, thereby being a barrier to the transfer of radiant thermal energy whilst remaining transparent to visible light.

An analogous technology is the use of specially formulated paints for painting metallic structures and armoured vehicles so that the painted surfaces reflect infrared radiation strongly, but have pleasant visual colours such as tans and browns. The temperature inside these structures or vehicles is reduced significantly. Hence the technology finds application on defence vehicles and structures located in tropical and desert areas where high solar intensities are encountered, although its effectiveness is generally limited.

A further set of applications are so-called "hot mirrors" which are coatings produced by multiple layers of dielectrics such as SiO 2 TiO 2 ZrO 2 and the like arranged in such order and thickness that radiation of visible and UV wavelengths transmit clearly while wavelengths in the near IR and longer are reflected. An example of such are the filters SP-0860-S and SP-0950-S available from Spectrogon. These coatings may be deposited on the external surface of quartz halogen light bulbs sc that heat is reflected inwards onto the filament in order to gain maximum visible radiation emission for a given level of heat energy supplied to the filament. They are also used on filters placed between intense lights and thermally sensitive objects being illuminated for purposes such as photography.

Whilst multiple layer optical coatings are known for spectacle lens applications, these are specifically to reduce the level of reflection of visible light by the lens surface. High quality multiple layer coatings tend to reflect the infrared and they also tend to reflect the UV wavelengths. There is no application of an optical coating for spectacle lenses where the IR and near IR wavelengths are selectively reflected, as this presents no major benefit to cosmetics or to the eyes of wearers.

Photochromic optical articles may contain the photoreactive material PCT/Au 9 5 0 0 8 4 RECEIVED 2 6 AUG 1996 -3throughout their bulk, in a region subjacent their surfaces, or in which a sandwich of layers that comprise the overall physical structure of the article. Being intended for the transmission of light, its focusing or its filtering, the outer surfaces of such articles are usually exposed to the full intensity of solar radiation. Hence, absorbed near infrared radiation causes the optical article to heat up, reaching temperatures substantially above the ambient air. This heating effect has a deleterious effect on the photochromic performance of the optical article, as outlined above and as demonstrated in Figures 1, 2 and 3.

It is accordingly an object of the present invention to overcome or at least 0o alleviate one or more of the difficulties and deficiencies related to the prior art.

Accordingly, in a first aspect of the present invention there is provided a photochromic light-transmissible article including a glass or polymeric article including a photochromic dye or pigment; and a coating on the glass or polymeric article which selectively reflects the red, infrared (IR) and near infrared (NIR) wavelength of light.

According to the present invention, a coating is applied to the exposed surfaces of the optical articles designed to make the surfaces highly reflective to infrared and near infrared radiation, but which preferably does not substantially interfere with transmission in the ultraviolet (UV) wavelength range. The heating of the articles above ambient temperature is thereby limited and the photochromic action is sustained in intense solar exposure.

The polymeric article, where applicable, may be of any suitable type. A polycarbonate, for example a material of the diallyl glycol carbonate type may be used. The polymeric article may be formed from cross-linkable polymeric casting compositions, for example as described in the applicant's United States Patent 4,912,155, United States Patent No. 5,373,033, Australian Patent Applications 50581/93, 50582/93, European Patent Specification 453159A2 or co-pending International Patent Applications PCT/AU95/00862 and PCT/AU95/00851, the entire disclosures of which are incorporated herein by refe'-nce.

Such cross-linkable polymeric casting compositic ;,ay include a 4' y AMENDED SHEET

IPEA/AU

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WO 96/18927 FCTIAU95/00845 -4diacrylate or dimethacrylate monomer (such as polyoxyalkylene glycol diacrylate or dimethacryla'.e or a bisphenol fluorene diacrylate or dimethacrylate) and a polymerisable comonomer, e.g. methacrylates, acrylates, vinyls, vinyl ethers, allyls, aromatic olefins, ethers, polythiols and the like.

Such polymeric formulations are UV cured or cured by a combination of UV and thermal treatment. The range of optical lenses sold under the trade designation "Spectralite" by the Applicants have been found to be suitable.

The pigment(s) or dye(s) including photochromic dye(s) may be selected from one or more of the group consisting of anthraquinones, phthalocyanines, spiro-oxazines, chromenes, pyrans including spiro-pyrans and fulgides.

Examples of preferred photochromic dyes may be selected from the group consisting of 1 ,3-dihydrospiro[2H-anthra[2,3-d]imidazole-2, 1'-cyclohexane]-5,1I0-dione 1, I3-d ihyd rospi ro[2 H-a nth ral2, 3-d] imid azolIe-2, I -cyclo hexa ne]-6, 11 -dione 1 ,3-dihyd ro-4-(phenylthio)spirojl2H-anthra'1 ,2-diimidazole-2, 1'-cyclohexane]- 6,1 1-dione 3-d ih yd rospi ro[2-H-a nth ra[1, imid azo le-2, 1 '-cycl ohepta ne]-6, 'I -dione 1,3, 3-trimethylspiro'indole-2, 3'-[3H~naphtho[2,1I-b]-1 ,4-oxazine] ethyl-3,3'-spiro-bi-[3H-naphtho[2,1-b]pyran] (2-Me) 2-phenyl-3-methyl-7-methoxy-8'-nitrospiro[4H-1 -benzopyran-4, nap htho][2, 1-bipyran a Spiro[2 H-I -benzopyran-2,9'-xanthene] 8-methoxy-1 ',3'-dimethylspiro-(2H- 1 -be nzopyra n-2, u ino line o 2,2'-Spiro-bi-[2H-1 -benzopyran] e 5'-amino-1, ,3',3'-trirriethylspiro[2H-1 -benzopyran-2,2'-indoline Ethyl- P-mnethyl-r3-(3', 3'-d imethyl-6-n itros p iro(2 H -1 -benzopyran-2,2'-indolin-1' yl)-propenoate 3-propanediyl)bis[3' ,3'-dimethyl-6-nitrospiro[2H-1 -benzopyran-2,2'indoline] a 3, 3'-d imethyl-6-nitrospiro[2H-1 -benzopyrao-2,2'-benzoxazoline] 6'-methylthio-3, 3'-d imethyl-8-methoxy-6-nitrospiro[2H-1 -benzopyran-2, 2'benzothiozoline] L- IL- -s WO 96/18927 PCT/AU95/00845 (1,2-ethanediyl)bis[8-methoxy-3-methyl-6-nitrospiro[2H-1 -benzopyran-2,2'benzothiozoline] N-N'-bis(3,3'-dimethyl-6-nitrospiro[2H-1-benzopyran-2,2'(3'H)-benzothioazol- 6'-yl)decanediamide -a-(2,5-dimethyl-3-furyl)ethylidene(Z)-ethylidenesuccinic anhydride; o 2,5-diphenyl-4-(2'-chlorophenyl)imidazole [(2',4'-dinitrophenyl)methyl]-1 H-benzimidazole N-N-diethyl-2-phenyl-2H-phenanthro[9,10-d]imidazol-2-amine 2-Nitro-3-aminofluoren o 2-amino-4-(2'-furanyl)-6H-1,3-thiazine-6-thione The infrared reflective coating may be a multiple layer optical coating designed to reflect the near infrared part of the spectrum, or it may be a transparent or semi-transparent coating that contains pigments or other constituents which exhibit reflectivity in the near infrared. Such constituents may include fragments of an optical coating with infrared reflectivity, such fragments having been obtained by first creating a coating on a substrate, next separating the coating from the substrate, grinding the coating to a fine particulate material and finally applying the particulate material in a polymeric binder to the lens surface. The coating may include pigments selected from the group consisting of, but not limited to, dielectric materials such as SiO 2 TiO 2 ZrO 2 and the like.

The infrared reflective coating may be of the Spectrogon type, for example filters SP-0869-S and SP-9050-S. Such filters exhibit a transmission cut-off at approximately 860 and 950 nm 25 nm respectively.

The surface treatment need not be fully transparent in the visible spectrum and may provide a background coloration or involve a metallic mirror which reflects part of the visible light shining on the optical article.

In addtion to photochromic dyes or molecules, there are dyes or pigments that change colour according to their temperature. These so-called "thermo chromic" materials have not been applied in optical articles such as spectacle lenses or sunglass lenses because the anticipated speed at which the temperature of the host material changes when exposed to intense solar radiation P III ~C4~

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WO 96/18927 PCT/AU95/00845 -6is judged insufficient to give a useful visual effect. It has been realised that the converse of the technology described above provides a useful means by which to achieve the required sensitivity. If the appropriate molecules are provided within a host material or, ideally in a zone just below its exposed surface, a light sensitive spectacle lens, window or filter may be achieved by treating the exposed surface so that it selectively absorbs incident near infrared radiation.

Accordingly in a further aspect of the present invention there is provided a thermochromic light-transmissible article including a glass or polymeric article including a thermochromic dye; and an infrared absorptive coating on the glass or polymeric article.

The surface temperature of the optical article is thus rendered sensitive to the intensity of infrared radiation. Since infrared and visible wavelengths occur in association with one another, the surface temperature of the article is thus responsive to the level of visible radiation. Providing a thermochromic molecular structure in the subjacent material creates the ability to change the optical density of the optical article with useful speed.

The surface treatment in this case could be an appropriate optical coating or a layer of material containii, a component which absorbs near infrared radiation strongly.

The present invention will now be more fully described with reference to the accompanying figures and examples. It should be understood, however, that the description following is illustrative only and should not be taken in any way as a restriction on the generality of the invention described above.

FIGURES:

In the Figures: Figure 1 illustrates the darkening characteristics of inorganic photochromics with time and temperature.

Figure la illustrates the Spectral characteristics of an inorganic based photochromic material in its exposed and bleached states, and is a plot of Transmittance versus Wavelength for a photochromic glass Reactolite Rapide. These curves relate to glass 2 mm thick at 250C (a) spectral transmittance, darkening and fading.

re-l r WO 96/18927 PCT/AU95/00845 -7- Figure lb illustrates transmittance versus time and temperature characteristics of an inorganic based photochromic material in its exposed state, and is a plot of Transmittance versus Time.

Figure 2 illustrates the darkening characteristics of organic photochromics with temperature.

Figure 2a illustrates the visible spectra of Transitions Comfort Lenses.

Figure 2b illustrates the photochromic performance of Transitions Comfort Lenses.

Figure 3 illustrates the coour changes of organic photochromics with temperature.

Figure 3a illustrates a plot of darkened state Integreted Visible Transmission (IVT), i.e. %T 10 minutes darkening in the prsence of a simulated AirMass 2 darkening source (10mD) vs Temperature for TS PLUS in the presence of various cut-off filters.

Figure 3b illustrates a plot of darkened states of TS PLUS at various temperatures and in the presence of various cut-off filters.

Figure 4 is a plot of Transmittance versus Wavelength for IR reflective coating #3 described below.

Figure 5 is a plot of Transmittance versus Wavelength for IR reflective coating #4 described below.

Figures 6a and 6b are plots of Transmittance versus Wavelength for IR reflective coating 39422.

Figure 7 is a plot of Transmittance versus Time for an IR reflector #3 on Transitions Comfort Lenses.

Figure 8 is a plot of Transmittance versus Time for an IR reflector #4 on Transitions Comfort Lenses.

Figure 9 is a plot of Transmittance versus Time for the IR reflector #4 on a Spectralite Raving Grey lens (Grey Figure 10 is a plot of Transmittance versus Time for the IR reflector 39422 on a Transitions Comfort Lens.

Figure 11 is a plot of Transmittance versus Time for the IR reflector 39422 on a Spectralite Raving Grey lens.

L -Y ~r Illpgsl, WO 96/18927 PCT/AU95/00845 -8- Figure 12 is a plot of Transmittance versus Time for the IR reflector 39422 under a Transitions Comfort Lens.

Figure 13 is a plot of Transmittance versus Time for the IR reflector 39422 under a Spectralite Raving Grey lens.

EXAMPLE 1 In each of the examples following, a glass lens, a commercial Transitions Optical Photochromic polymer lens (Transitions Comfort Lens) or a commercial Spectralite (Sola) polymer lens bearing a Pilkington "Raving Grey" photochromic coating (Raving Grey was used.

At least one transparent substrate bearing an infrared (IR) reflective coating was placed adjacent to the upper or lower surface of the lens. One half of the IR reflective coating had been removed from the transparent substrate. This meant that half the lens was experiencing the effect of the IR filter and the adjoining portion was exp( encing the effect of the radiation only modified by the substrate on which the filter had originally been placed.

The experiment performed in each case was to expose the photochromic lens for 45 secunds to a 1000 Watt halogen lamp (Turbo-lux 3004) located about cm from the front surface of the lens and operated without any cooling, such that the maximum amount of heat as well as activating light was impinging on the lens surface. This was used as it was not possible to perform %T measurements on the samples in the external environment, although visually the effects seen on the samples exposed under the UV filters with the lamp were very similar to those observed when we exposed the samples to natural sunlight.

The sequence of operations was: 1) Expose the covered lens for 45 seconds 2) As rapidly as possible remove the covering filter, 3) Using the Gardner Colorimeter, record a* and b* values for the region under investigation as fast as the duty cycle of the instrument will allow, which is approximately 16 seconds between measurements, starting initially with the IR refiective coating portion, then the IR reflective coating removed portion and so on sequentially for usually 6 or more cycles.

I~ se Irrsl 8888 WO 96118927 PCT/AU95/00845 -9- The above sequence was then repeated with the sample being reexposed and the readings being taken again, but this time with the IR reflective coating removed portion being read first, followed by the IR reflective coating portion of the lenses.

By this means two graphs may be combined, one starting in time initially with the IR reflective coating portion and the other starting in time initially with the portion of the lens which had been covered with the material from which the mirror material had been removed. The aim of this was to eliminate the influence of the substrate on which the particular IR reflective coating had been applied and also to eliminate the effect o; time from "light off' on the results.

The above sequence was used when only a single IR substrate was being investigated on each surface, ie. for IR reflective coatings #3 and which were supplied on glass substrates and which are multilayer thin film mirrors which had been tuned to give high reflectance in the 600 nm and above region of the spectrum and for sample 39422 (from Edmund Scientific) which is a heat reflector on a plastic film, possibly Mylar. Transmission data thereon are provided in Tables 1, 2 :nd 3 and Figures 4, 5 and 6a and 6b respectively.

Ir ~a Ig WO 96/18927 PCT/AU95/00845 TABLE I Transmission Values 300 33.2 310 I55.2 320 65.1 330 83.2 340 72.9 350 86.6 360 92.0 370 76.8 380 90.3 390 90.1 400 85.9 410 93.2 420 91.3 430 83.5 440 78.7 450 93.5 460 88.8 470 89.7 480 80.5 490 85.0 500 83.8 510 91.5 520 93/6 530 80.6 540 72.9 550 88.3 560 87.0 570 65.2 580 82.4 590 49.2 600 7.7 610 620 0.8 630 640 0.3 650 0.2 660 0.2 670 0.3 680 10.3 690 700 0.8 710 1.7 720 4.4 730 16.9 740 74.8 750 72.2 760 45.5 770 42.2 780 51.4

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WO 96/18927 PCTIAU)5/00845 Chromaticitv Co-Ordinates x 0.2180 y= 0.3061 z 0.4759 L* 84,9768 a= -43.9881 b* -16.6905 Y 65.9615 WO 96/18927 PCT/AU95/00845 -12- TABLE 2 Transmission Values 300 134.0 31014.

320 73.0 330 68.0 340 76.6 1350 74.2 360 8 5. 0 8.

380 84.4 390 f86.3 400 83.9 410 8 ~8.1 420 89.0 430 89.7 440 86.1 450 91.1 460 84.2 470 90.1 480 89.9 490 88.3 500 87.1 510 8.

520 88.9 530 90.0 540 84.4 550 91.4 560 88,2 570 76.6 580 82.4 590 83.5 600 59.4 60 52.9 620 85.1 6310 37.1 640 6.7 650 660 0.9 670 680 0.4 690 0.3 700 0.3 7100.

720 0.4 7300.

740 0.9 750 1.8 760 3.9 770 11.6 780 42.3 Optical Transmission Results Iluminant C transmittance 79.12% WO 96/18927 PCTAU95/00845 -13- Chromaticityj Co-Ordinates x =O.2732 y=O0.3138 z=O0.4130 L* =92.2864 a* -17.9533 b* -6.7992 Y =79.1152 11;11111~- -1 WO 96/18927 PCT/AU95/00845 -14- TABLE 3 Transmission Values 300 0.0 310 0.0 320 8.2 330 28.7 340 35.2 350 40.9 360 46.7 370 53.7 380 59.3 390 64.1 400 68.3 410 71.8 420 74.5 430 76.7 440 78.5 450 80.0 460 81.3 470 82.1 480 83.1 490 83.7 500 84.1 510 84.7 520 84.8 530 84.8 540 84.9 550 84.8 560 84.6 570 84.2 580 83.8 590 83.4 600 82.8 610 82.2 620 81.4 630 80.5 640 79.7 650 78.8 660 77.9 670 76.8 75.7 690 74.5 700 73.4 710 72.3 720 71.2 730 70.0 740 68.8 750 67.5 760 66.1 770 64.8 780 63.6 Optical Transmission Results Illuminant C transmittance 83.75% L las PT T

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WO 96/18927 PCT/AU95/00845 Chromaticity Co-Ordinates x 0.3108 y 0.3238 z 0.3654 L* 93.3402 a* =--3.3128 b* -2.8488 Y 83.7464 The Transitions lenses are covered with IR reflective coatings #3 and #4, which are coatings with low transmissions in the region of 610 to 710 and 650 to 750 nm respectively. The samples were multi-layer films tuned for reflecting red light greater than 610 nm. The results are presented in Tables 4 and 5 and Figures 7 and 8, respectively.

91 ge 1 WO 96/18927 PCT/AU95/00845 -16- TABLE 4 Time T %T %T (Mirror 4 first) (Non-Mirror #3 second) (Mirror #3 second) 58.46 67.21 68.35 71.94 71.74 74.07 73.51 75.13 74.71 100 75.96 110 75.36 120 76.58 130 75.98 140 76.95 150 76.41 160 77.19 61.48 67.82 70.88 72.7 100 73.89 110 120 74.73 lrl P--l I~ IEIF WO 96/18927 PCTAU95OOS45 -17- Time T %T 1%T (Mirror 4 first) (Non-Mirror #3 second) )I(Mirror #3 second) 13130 140 75.55 Note Each 10 -secs is about 16 sec~onds in real time WO 96/18927 PCT/AU95/00845 -18- TABLE Time %T (Mirror #4 %T (Non-Mirror %T (Mirror #4 %T (Non-Mirror first) #4 second) second) #4 first) 58.49 64.98 66.56 70.18 70.94 73.28 73.51 75.01 75.13 100 76.17 110 76.18 120 77.02 130 77.03 140 77.55 150 160 59.53 63.82 67.11 68.97 73.19 72.38 74.86 74.27 75.95 100 75.61 110 76.8 120 76.5

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WO 96/18927 PCT/AU95/00845 Time %T (Mirror #4 %T (Non-Mirror %T (Mirror #4 %T (Non-Mirror first) #4 second) second) #4 first) 130 77.3 140 77.28 Note Each 10 secs is about 16 seconds in real time Figures 7 and 8 show clearly in both brackets, the %T of the region which was covered by the reflecting surface are lower than the similar areas which had not been covered by the IR reflector and so the IR reflector is performing as predicted.

EXAMPLE 2 A similar experiment was performed as in Example 1, but with iR reflective boating #4 on Raving Grey in Spectralite (Grey The results are presented in Table 6 and Figure 9 Again clearly the UV reflector is performing as predicted.

Y IIIP-- r 1~1 ~11~1 WO 96/18927 PCT/AU95/00845 TABLE 6 Time %T (Mirror #4 %T (Non-Mirror %T (Mirror #4 %T (Non-Mirror first on BI) #4 second) second) #4 first) 71.02 78.49 80.1 82.08 82.27 83.21 83 83.56 83.48 100 83.95 110 83.76 120 84.14 72.89 77.75 80.75 81.28 82.24 82.37 82.99 83.04 83.52 100 83.44 110 83.73 120 83.65 Note Each 10 secs is about 16 seconds in real time ai I I IP~sC1 bPli WO 96/18927 PCT/AU95/00845 -21- EXAMPLE 3 UV reflective coating 39422 is placed on Transitions and Sr!ctralite Raving Grey lenses. The results are presented in Tables 7 and 8 and Figures and 11.

~c pk I I I WO 96/18927 PCT/AU95/00845 -22- TABLE 7 Time %T (Mirror 39422 first on Transitions) %T (Non-Mirror second) oT (Mirror 39422 second) %T (Non-Mirror first) 67.65 69.61 71.67 73.02 74.04 75.61 76.42 76.85 100 77.44 110 77.44 120 78.15 67.49 69.93 71.9 72.98 73.34 74.87 75.99 75.98 76.98 100 77.1 110 77.77 120 77.79 Note Each 10 secs is about 16 seconds in real time I i sil La -C L1- WO 96/18927 PCT/AU95/00845 -23- TABLE 8 Time %T (Mirror %T (Non-Mirror %T (Mirror %T (Non-Mirror 39422 first on second) 39422 second) first) Grey (BI)) 68.89 75.89 77.8 80.67 81.04 82.41 82.41 83.26 83.11 100 83.75 110 83.53 120 84.06 71.55 76.35 78.98 80.3 81.45 81.92 82.53 82.73 83.23 100 83.16 110 83.52 120 83.46 Note Each 10 secs is about 16 seconds in real time P& I_ ICr IC-- WO 96/18927 PCT/AU900845 -24- Whilst the differences between the coated and uncoated lenses are smaller, the results are again as predicted. The poorer results reflect the fact that 39422 is an inferior IR reflector to coatings #3 and #4.

EXAMPLE 4 Example 3 was repeated except that the IR reflector 39422 was placed under the Transitions and Spectralite Raving Grey lenses.

The results are presented in Tables 9 and 10 and Figures 12 and 13.

a 1I WO 96/18927 WO 9618927PCTIAU95/00845 TABLE 9 Time %T (Mirror 39422 first under T ransitions) %T (Non- Mirror second) %T (Mirror 39422 second) %T (Non- Mirror first) 61.22 65.34 67.71 70.01 71.15 72.38 73.2 73.92 74.61 100 75.1 110 75.6 120 75.87 61 .'09 65.58 68.4 70.53 1~.8 72.87 7.4 74.27 73574.78 -100753 110 75.62 120 76.06 Note 10 secs is about 16 seconds in real time WO 96/18927 PCTIAU95/00845 -26,- TABLE Timna %T (Mirror 39422 first %T (Non-Mirror %T (Mirror %T (Nonunder Grey (B31)) second) 39422 second) Mirror first) 67.26 72.44 77.46 78 80.07 80.19 81.22 ~81.02 81.79 100 81.73 110 82.07 120 82.08 67.13 75.89 76.99 140 79.8 79.76 81.08- 81.04 81.65 190 81,55 100 82.03 110 81.95 120 82.29 Note Each 10 -secs is about 16 seconds in real time ~I I~ I WO 96/18927 PCT/AU95/00845 -27- The poorer re3ults achieved suggest that the coatings are preferably placed on the lenses.

Finally, it is to be understood that various other modifications and/or alterations may be made without departing from the spirit of the present invention as outlined herein.

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Claims (9)

1. A photochromic light-transmissible ophthalmic article including a glass or polymeric ophthalmic article-including a photochromic dye or pigment; and a coating on the exposed surface of the article which selectively reflects the red, infrared (IR) and near infrared (NIR) wavelength of light and which does not substantially interfere with transmission in the ultraviolet (UV) wavelength range.

2. An article according to claim 1 wherein the coating selectively reflects the io red and NIR wavelength of light.

3. An article according to claim 1 wherein the coating selectively reflects the red wavelength of light.

4. An article according to claim 1 wherein the article is formed from a cross- linkable polymeric casting composition including a diacrylate or dimethacrylate monomer and a polymerisable comonomer.

An article according to claim 4 wherein the polymerisable comonomer is selected from methacrylates, acrylates, vinyls, vinyl ethers, allyls, aromatic olefins, ethers and polythiols.

6. An article according to claim 1 wherein the photochromic dye is selected from one or more of the group consisting of anthraquinones, phthalocyanines, spiro-oxazines, chromenes, pyrans and fulgides.

7. An article according to claim 1 wherein the coating includes a multiple layer optical coatingbr a transparent or semi-transparent coating containing pigments or other constituents which exhibit reflectivity in the infrared and near infrared wavelength range.

8. An article according to claim 7 wherein the coating is a transparent or semi- transparent coating including pigments selected from the group consisting of the oxides and oxygen containing species of Al, In, Nb, Si, Sn, Ta, Ti, Y and Zr and mixtures thereof.

9. An article according to claim 1 wherein the article is an ophthalmic lens. AMENDED SHEET u IPEA/AU I