Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
1999-08-27
2001-05-01
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S281100, C522S018000
Reexamination Certificate
active
06225021
ABSTRACT:
The present invention relates generally to a photopolymerizable composition, comprising at least one polymerizable monomer with a labile proton and at least one polymerizable monomer comprising one or more iso(thio)cyanate functional groups, in particular for the manufacture of optical articles, such as organic ophthalmic glasses or coating varnishes for optical articles made of organic glass.
Organic ophthalmic glasses are lighter, less brittle and more easily colorable than inorganic glasses. Furthermore, the process of working them is often easier. For these reasons, organic ophthalmic glasses have shown great development in recent years.
Thus, a polymer obtained by polymerization of ethylene glycol bis(allyl carbonate) is commonly used for the manufacture of ophthalmic lenses made of organic glass. The polymerized resins obtained from this polymer have excellent properties of impact strength, of colorability and of lightness.
Nevertheless, the refractive index of the organic glasses obtained (n
D
=1.50) is significantly lower than that of conventional inorganic glasses, which implies an increase in thickness at the center of the lens.
In order to overcome this disadvantage, ophthalmic lenses made of organic glass have been prepared which are made from polythiourethane, which lenses make it possible to satisfy this requirement.
Thus, U.S. Pat. No. 4,775,733 discloses the manufacture of organic lenses with a high refractive index obtained by thermal polymerization of a polyisocyanate and of a polythiol.
U.S. Pat. No. 4,689,387 discloses the manufacture of a resin for lenses based on S-alkyl thiocarbamate, which consists in thermally polymerizing one or more compounds comprising one or more isocyanate functional groups with one or more aliphatic compounds comprising one or more SH groups.
Patent EP-A-0,751,161 discloses, for its part, the production of organic glasses by UV polymerization of a polythiol compound and of a polyiso(thio)cyanate compound, and a compound having two or more reactive unsaturated groups and a photopolymerization catalyst. Although this document indicates that the composition can be polymerized in a short period of time, even by photopolymerization, all the examples in this document relate to a mixed polymerization comprising a prepolymerization by UV irradiation for at least 15 minutes, followed by thermal polymerization for at least 2 hours.
It would therefore be desirable to have available compositions for the manufacture of organic glasses, in particular organic glasses with a high refractive index (>1.54), which can be rapidly photopolymerized, in particular by UV polymerization.
An object of the present invention is therefore to provide a monomer composition, in particular for the manufacture of optical articles, which is rapidly photopolymerizable.
An object of the present invention is more particularly to provide photopolymerizable compositions, in particular for the manufacture of organic glasses, comprising monomers with a labile proton and with an iso(thio)cyanate functional group, which are easily and rapidly photopolymerizable.
A further subject-matter of the present invention is compositions as defined above for the manufacture of organic glasses with a high refractive index (greater than 1.54).
Another subject-matter of the invention is optical articles and in particular ophthalmic lenses obtained by photopolymerization of the above compositions.
It has been found, surprisingly, that, by adding a specific activating agent to a photopolymerizable composition comprising at least one monomer with a labile proton and at least one monomer comprising one or more iso(thio)cyanate functional groups and a photoinitiating agent, it is possible to obtain compositions which can photopolymerize in a very short time.
More particularly, it has been found that, by adding an activating agent chosen from phosphines and phosphorus halides to the compositions based on monomers with a labile proton and with an iso(thio)cyanate functional group comprising a conventional polymerization photoinitiator, an exceptional acceleration of the photopolymerization of the composition, in particular under the action of ultraviolet radiation, is very surprisingly obtained.
According to the invention, the photopolymerizable compositions comprise at least one polymerizable monomer with labile protons and at least one polymerizable monomer comprising one or more iso(thio)cyanate functional groups and a photoinitiating agent and are characterized in that they comprise at least one agent for activating the photoinitiating agent chosen from phosphines, phosphorus halides and their mixtures.
Phosphines are trivalent phosphorus compounds and the phosphorus halides coming within the scope of the present invention are preferably phosphorus compounds in which the phosphorus atom is trivalent.
Phosphines suitable in the present invention can be represented by the formula (R)
3-x
PH
x
(I), in which the R radicals, which are identical or different, represent a linear or branched alkyl radical, an unsubstituted or substituted cycloalkyl radical, a linear or branched alkenyl radical, an unsubstituted or substituted cycloalkenyl radical, an unsubstituted or substituted aryl radical, an unsubstituted or substituted (alkyl)aryl radical or an (unsubstituted or substituted aryl)alkyl radical and x is an integer equal to 0, 1 or 2.
In the present application, the term “activating agent” is understood to mean any compound or mixture of compounds which, combined with the photoinitiating agent of the polymerizable mixture, increases the rate of photopolymerization of the mixture with respect to the rate of polymerization of this same mixture not comprising the activating agent and subjected to the same photopolymerization conditions.
A first polymerizable monomer constituent of the compositions according to the invention comprises one or more polymerizable monomers with a labile proton.
The term “polymerizable monomer with a labile proton” is understood to mean, in the present invention, any monomer comprising one or more functional groups having at least one labile hydrogen atom.
The monomers with a labile proton according to the invention are preferably devoid of an unsaturated group polymerizable by the radical route.
The compounds with a labile proton of the present invention which are recommended are the compounds comprising thiol (SH), alcohol (OH) and primary or secondary amine (NH
2
; NH) functional groups or combinations of these functional groups.
Mention may be made, among the compounds with a labile proton which are recommended in the present invention, of aliphatic polythiols, aromatic polythiols, halogenated aromatic polythiols or heterocyclic polythiols. Numerous examples of these polythiols which can be used in the present invention are given in Patent EP-A-0,751,161.
Mention may be made, among the polythiols which are recommended according to the present invention, of aliphatic polythiols, such as pentaerythritol tetrakis(3-mercaptopropionate).
A recommended class of aliphatic polythiols corresponds to the formula (II):
in which R
1
, R
2
and R
3
represent H or SH, x, y and z are integers between 0 and 8, preferably between 1 and 4, and at least two from R
1
, R
2
and R
3
represent an SH group.
Mention may be made, among the compounds of formula (II) above, or 1-(1′-mercaptoethylthio)-2,3-dimercaptopropane [sic], 1-(2′-mercaptopropylthio)-2,3-dimercaptopropane [sic], 1-(3′-mercaptopropylthio)-2,3-dimercaptopropane, 1-(4′-mercaptobutylthio)-2,3-dimercaptopropane, 1-(5′-mercaptopentylthio)-2,3-dimercaptopropane, 1-(6′-mercaptohexylthio)-2,3-mercaptopropane, 1,2-bis(1′-mercaptomethylthio)-3-mercaptopropane, 1,2-bis(2′-mercaptoethylthio)-3-mercaptopropane, 1,2-bis(3′-mercaptopropylthio)-3-mercaptopropane, 1,2-bis(4′-mercaptobutylthio)-3-mercaptopropane, 1,2-bis(5′-mercaptopentylthio)-3-mercaptopropane, 1,2-bis(6′-mercaptohexylthio)-3-mercaptopropane, 1,2,3-tris(1′-merca
Marchand Jean-Paul
Widawski Gilles
Yean Leanirith
Ashton Rosemary
Essilor International Compagnie Generale d 'Optique
Fulbright & Jaworski LLP
Le Hoa Van
LandOfFree
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