Compositions – Light transmission modifying compositions – Displaying color change
Reexamination Certificate
1998-10-16
2001-01-16
Tucker, Philip (Department: 1721)
Compositions
Light transmission modifying compositions
Displaying color change
C523S106000, C351S163000
Reexamination Certificate
active
06174464
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to photochromic organic contact lenses.
BACKGROUND OF THE INVENTION
Even though plastic contact lenses have been available for many years, plastic photochromic contact lenses remain relatively rare. A photochromic hard contact lens is disclosed in Japanese patent publication no. JP 4-208919 (1992), and JP 63-306418 (1988).
It is desirable to have a photochromic material which can be used in the production of a contact lens whose transmittance varies as a function of light. Outside of their photochromic properties (i.e., colorability, rapid darkening and lightening kinetics, acceptable durability, etc.), such lenses are generally made by the use of appropriate mixtures of photochromic compounds. Even though the polymer matrix used for such lenses are thermally crosslinked, they tend to have a low glass transition point, generally lower than that of CR39®, a reference ophthalmic resin consisting of diethylene glycol bis(allyl carbonate) available from PPG Industries, in order to exhibit rapid photochromic kinetics. Moreover, these polymers generally have a relatively low refractive index (below 1.54).
The majority of these thermally crosslinked matrixes are obtained by radical polymerization (i.e., polymerization which most often can only be carried out provided that one uses initiators of the organic peroxide type.) The use of organic peroxides makes it practically impossible to incorporate photochromic molecules in the mixture of monomers before polymerization, the peroxides having the effect either of destroying any photochromic effect or of giving the product an unacceptable permanent intense coloration.
Therefore, there continues to be a need for photochromic organic contact lenses having improved photochromic properties and which are relatively easy to manufacture.
SUMMARY OF THE INVENTION
Briefly, the invention is directed at organic photochromic contact lenses, in particular, a plastic contact lens. The lens is composed of (1) a polymer matrix of high optical quality, and (2) at least one dye capable of imparting photochromic properties on the lens.
In one aspect, it relates to a photochromic contact lens comprising organic photochromic materials consisting of a transparent polymer having a refractive index equal to at least 1.54, and at least one photochromic dye selected from the group consisting of spirooxazines, spiropyrans, chromenes and a mixture of these, wherein the polymer is a copolymer of at least two monomers selected from the group consisting of:
(i) homopolymers of ethoxylated bisphenol A dimethylacrylate with formula I:
where R is H or CH
3
, and m and n independently represent 1 or 2;
(ii) ethoxylated bisphenol A dimethylacrylate containing at most 30 weight percent of an aromatic monomer with vinyl, acrylic or methacrylic functionality;
(iii) an aromatic monovinyl monomer represented by the general formula (II):
in which R
1
=H or CH
3
(iv) an aromatic divinyl monomer represented by general formula (III):
in wnich R
1
=H or CH
3
;
(v) a polyurethane oligomer with terminal di- or triacrylic or di- or trimethacrylic functionality,
(vi) a (meth)acrylic monomer corresponding to the general formula:
CH
2
═C(R)—COOR′
in which R=H or CH
3
,
R′ is a straight-chain or branched C
4
to C
16
alkyl radical, an alkylaryl radical, or a polyethoxylated group with formula —(CH
2
—CH
2
O)
n
R″ in which n=1 to 10 and R″=CH
3
or C
2
H
5
;
(vii) styrene; and
(viii) divinylbenzene;
(ix) diallyl phthalate;
(x) benzyl methacrylate;
(xi) benzyl acrylate;
(xii) naphthyl methacrylate; and
(xiii) naphthyl acrylate.
In another aspect, the invention relates to a photochromic contact lens in which the polymer is a copolymer selected from the group consisting of divinylbenzene, diallyl phthalate, benzyl methacrylate, benzyl acrylate, naphthyl methacrylate and naphthyl acrylate, and their derivatives substituted on the aromatic nuclei by chlorine or bromine atoms.
REFERENCES:
patent: 4306780 (1981-12-01), Tarumi et al.
patent: 5395566 (1995-03-01), Kobayakawa et al.
patent: 5808063 (1998-09-01), Kumar
patent: 5981634 (1999-11-01), Smith et al.
patent: 6034193 (2000-03-01), Henry et al.
patent: 95/10790 (1995-04-01), None
Corning Incorporated
Nwaneri Angela N.
Rogalskyj Peter
Tucker Philip
LandOfFree
Organic photochromic contact lens compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Organic photochromic contact lens compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Organic photochromic contact lens compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2513507