Compositions – Light transmission modifying compositions – Displaying color change
Patent
1998-10-23
2000-08-01
Dentz, Bernard
Compositions
Light transmission modifying compositions
Displaying color change
524110, 526268, 549331, 549389, 549 58, 549 60, 5462827, 548440, C08K 515, C07D31192
Patent
active
060962461
DESCRIPTION:
BRIEF SUMMARY
The present invention concerns novel compounds of the naphthopyran type, presenting, in particular, photochromic properties. It also concerns the photochromic compositions and ophthalmic articles (for examples, lenses) which contain naphthopyrans.
Photochromic compounds are capable of changing colors due to the influence of poly- or monochromatic light (for example, UV radiation) and to recover their initial color again when the luminous irradiation stops, or under the influence of poly- or monochromatic light different from the first one, or under the influence of temperature and/or poly- or monochromatic light different from the first one.
These photochromic compounds find applications in different fields, for example, in the manufacture of ophthalmic lenses, contact lenses, sun protection glasses, filters, optical systems of cameras or photographic apparatuses or other optical and observation devices, paneling, decorative objects, display elements or for the storage of information by optical inscription (coding).
In the field of ophthalmic optics, and in particular in eyeglass wear, a photochromic lens, comprising one or more photochromic compounds, must present: brown) with, preferably, maintenance of the selected tint during the coloration or discoloration of the lens, 0-40.degree. C., hence corrective lenses are expensive.
These lens characteristics are in fact determined by the active photochromic compounds which must in addition be compatible with the organic material or mineral constituting the lens.
It should also be noted that the obtention of a gray or chestnut brown tint should require the use of at least two photochromes of different colors, that is, having different maximum absorption wavelengths in the visible range. This association also places other requirements on photochromic compounds. In particular the coloration and discoloration kinetics of the two or more associated active photochromic compounds must be essentially identical. The same applies to their stability over time and also, to their compatibility with a plastic or mineral support.
Among the numerous photochromic compounds described in the prior art, one can cite the naphthopyrans described in U.S. Pat. Nos. 3,567,605, 3,627,690, 4,826,977, 5,200,116, 5,458,814 and Research Disclosure No. 36144: ##STR2##
The claim is made that these compounds satisfy the above defined specifications. In fact, whereas these compounds have in fact one or more of the desired basic properties, such as high transmission in darkness and high colorability under solar irradiation, all the compounds described to this day do not have the complete combination of desired properties required for the production of satisfactory articles that can be manufactured industrially Although the prior art teaches how to modify the discoloration kinetics by the presence of a methyl group in R1 and R2, it does not teach how to modify the profile of the visible spectrum of the activated form (exposure to UV). The compounds of the prior art are generally orange or red with a principal absorption band in the visible range.
It is the merit of the applicant to have found, surprisingly, that the presence of at least two alkoxy groups, at R3 and R5, allowed the obtention of photochromes having two intense absorption bands in the visible range and at high values of .lambda..sub.max. The compounds of the invention thus cover a part of the visible spectrum (400-700 nm).
Thus, the present invention concerns compounds, particularly photochromic compounds, having the following general formula (I): ##STR3## in which: R1, R2, R4 and R6 are identical or different and they represent, independently atoms, preferably a fluoroalkyl group, preferably a vinyl or allyl group, formula//insert a, p.4// in which n=1, 2 or 3 a heteroaryl or heteroaryloxy group whose heteroaryl group comprises 4-24 carbon atoms and at least one heteroatom selected from the group consisting of sulfur, oxygen and nitrogen, the aryl or heteroaryl group optionally substituted by at least one substituent selected fro
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Bryson Nathan
Chan You-Ping
Corning Incorporated
Dentz Bernard
Nwaneri Angela N.
Rogalskyj Peter
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