Compositions – Light transmission modifying compositions – Displaying color change
Reexamination Certificate
2000-03-14
2003-12-30
Sanders, Kriellion A. (Department: 1714)
Compositions
Light transmission modifying compositions
Displaying color change
C252S183110, C528S373000, C528S376000
Reexamination Certificate
active
06669873
ABSTRACT:
DESCRIPTION OF THE INVENTION
The present invention relates to polymerizable organic compositions having reduced shrinkage and solid polymerizates prepared therefrom having a refractive index of at least 1.57, and an Abbe number of at least 33. Particularly, the present invention relates to certain polymerizable organic compositions comprising a substantially gel-free liquid prepolymer of a first polyethylenically unsaturated monomer and a polythiol monomer, and a separate second polyethylenically unsaturated monomer. More particularly, the polymerizable compositions of the present invention have a percent shrinkage less than that of a corresponding polymerizable composition containing no prepolymer.
Organic polymeric materials having refractive indices of at least 1.57 and low levels of chromatic dispersion have been developed recently as alternatives and replacements for high refractive index inorganic silica based glass for applications such as optical lenses. These polymeric materials can provide advantages relative to glass, including, shatter resistance, lighter weight for a given application, ease of molding and ease of dying. The chromatic dispersion of an optical lens is typically quantified with reference to Abbe numbers (also known as nu-values). Lower Abbe numbers are indicative of an increasing level of chromatic dispersion, which is typically manifested as an optical distortion at or near the rim of the lens. Values of Abbe numbers corresponding to desirably lower levels of chromatic dispersion are, for example, typically at least 33 and more typically at least 35.
It is known that polymeric materials having high refractive indices, e.g., of at least 1.57, and low levels of chromatic dispersion, e.g., having Abbe numbers of at least 33, can be prepared from polymerizable compositions containing monomers having at least two thiol groups and monomers having two or more radically polymerizable ethylenically unsaturated groups. Such compositions, which are referred to in the art as thiol-ene compositions, are described in, for example, U.S. Pat. No. 5,484,972, and International Patent Publication No. WO 96/38486.
Molded articles, such as lenses, are typically prepared by introducing a polymerizable composition into a mold, e.g., a glass mold, polymerizing the composition within the mold, and then removing the molded article from the mold. Many polymerizable organic compositions, e.g., polymerizable thiol-ene compositions, undergo a decrease or shrinkage in volume upon polymerization. This decrease in volume can cause the polymerizing composition to pull away from the interior surfaces of the mold resulting in the formation of defects in the molded article. Defects due to volume shrinkage include, for example, cracking, warping and surface anomalies, and typically require scrapping of the defective article, resulting in increased production costs.
Accordingly, it is desirable to develop polymerizable organic thiol-ene compositions having a reduced level of shrinkage upon polymerization, and from which can be prepared polymerizates, such as optical lenses and in particular ophthalmic lenses, having a combination of high refractive index, e.g., at least 1.57, and high Abbe values, e.g., at least 33, and preferably at least 35. It is further desirable that polymerizates prepared from such newly developed thiol-ene compositions also have physical properties, e.g., thermal properties, that are at least substantially the same as those of polymerizates prepared from corresponding thiol-ene compositions having a higher level of shrinkage.
U.S. Pat. No. 5,917,006 describes a polymerizable organic composition comprising an aromatic monomer having at least two vinyl groups, e.g., divinyl benzene, a polythiol monomer having at least two thiol groups, e.g., pentaerythritol tetrakis(2-mercaptoacetate), and an anhydride monomer having at least one ethylenically unsaturated group, e.g., methacrylic anhydride. The '006 patent does not describe compositions comprising radically polymerizable prepolymers of ethylenically unsaturated monomers and polythiols.
U.S. Pat. No. 5,976,422 describes a polymerizable organic composition comprising at least one polymerizable monomer having at least two ethylenically unsaturated groups, e.g., divinyl benzene, a novel polythiol monomer, e.g., thioglycerol bis(2-mercaptoacetate), and optionally a monoethylenically unsaturated monomer, e.g., phenoxyethyl methacrylate, and/or an anhydride monomer, e.g., methacrylic anhydride. The compositions of the '422 patent are not described as comprising radically polymerizable prepolymers of ethylenically unsaturated monomers and polythiols.
U.S. Pat. No. 5,593,795 describes a solvent-free polymerizable prepolymeric syrup comprising a multi-ene functional alkylene oxide, a multi-functional thiol, and an electrolyte salt. The '795 patent does not describe combining the prepolymeric syrup with additional radically polymerizable monomers prior to polymerizing the syrup to form an electrolyte composition in the form of a film.
U.S. Pat. No. 5,459,175 describes curable thiol-ene compositions comprising a polythiol and a compound having a plurality of norbornene groups, wherein one of either the polythiol or the compound having a plurality of norbornene groups has a poly(tetramethylene oxide) backbone, or is an oligomer thereof. The '175 patent further describes preparing the oligomer(s) by heating a mixture of the polythiol and the compound having a plurality of norbornene groups, and then formulating the curable thiol-ene composition by adding the appropriate quantity of the depleted monomer.
Japanese Kokai Patent Application No. 63-309509 describes high refractive resin compositions comprising (a) a vinyl group-terminated liquid thioether polymerizable monomer mixture and (b) a polymerizable monomer having terminal (meth)acryloyl groups. The vinyl group-terminated liquid thioether monomer (a) of JP 63-309509 is obtained by an addition reaction of divinylbenzene and a polythiol in the presence of a radical initiator, wherein the equivalent ratio of vinyl groups (of the divinylbenzene) to thiol groups (of the polythiol) is from 3:1 to 10:1.
In accordance with the present invention, there is provided a polymerizable organic composition comprising:
(a) a radically polymerizable prepolymer of,
(i) at least one first polymerizable monomer having at least two radically polymerizable ethylenically unsaturated groups, and
(ii) at least one first polythiol monomer having at least two thiol groups, the molar equivalent ratio of ethylenically unsaturated groups of (a)(i) to thiol groups of (a)(ii) is no greater than 1:1, and the percent consumption of ethylenically unsaturated groups of (a)(i) is selected such that said prepolymer is a substantially gel-free liquid at 25° C.; and
(b) at least one second polymerizable monomer having at least two radically polymerizable ethylenically unsaturated groups,
wherein a polymerizate of said polymerizable organic composition has a refractive index of at least 1.57, as determined in accordance with American Standard Test Method (ASTM) number D 542-95, an Abbe number, i.e., a nu-value, of at least 33, as determined using an appropriate instrument, e.g., a Bausch & Lomb ABBE-3L Refractometer, said polymerizable organic composition having a percent shrinkage less than that of a corresponding prepolymer-free polymerizable composition containing monomers (a)(i), (a)(ii) and (b), said first and second radically polymerizable monomers each being substantially free of norbornene groups.
Other than in the operating examples, or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, etc. used in the specification and claims are to be understood as modified in all instances by the term “about.”
DETAILED DESCRIPTION OF THE INVENTION
Polymerizable organic compositions according to the present invention have a percent shrinkage less than that of a corresponding prepolymer-free polymerizable composition containing the same mo
Herold Robert D.
Okoroafor Michael O.
Smith Robert A.
Franks James R.
Marmo Carol A.
PPC Industries Ohio, Inc.
Sanders Kriellion A.
LandOfFree
Optical resin composition comprising thiol-ene prepolymer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical resin composition comprising thiol-ene prepolymer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical resin composition comprising thiol-ene prepolymer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3143104