Polyfunctional thiirane compounds

Details Polyfunctional thiirane compounds Polyfunctional thiirane compounds

2001-02-28

2003-10-07

Berman, Susan W. (Department: 1711)

Optical: systems and elements

Optical modulator

Light wave temporal modulation

C359S242000, C359S243000, C359S244000, C522S031000, C522S074000, C522S168000, C522S170000, C528S377000, C528S378000, C528S380000, C549S001000, C549S090000, C549S518000, C549S523000

Reexamination Certificate

active

06631021

ABSTRACT:

DESCRIPTION OF THE INVENTION
The present invention relates to novel polyfunctional thiiranes. The present invention also relates to polymerizable compositions comprising one or more novel polyfunctional thiiranes, and polymerizates, e.g., optical lenses, prepared therefrom.
A number of polymeric materials, e.g., plastics, have been developed as alternatives and replacements for glass in applications such as, optical lenses, fiber optics, windows and automotive, nautical and aviation transparencies. As used herein, the term ‘glass’ is meant to refer to silica-based inorganic glass. 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. Representative examples of such polymeric materials include, poly(methyl methacrylate), thermoplastic polycarbonate and poly[diethylene glycol bis(allylcarbonate)].
The refractive indices of many polymeric materials can be lower than that of glass. For example, the refractive index of poly[diethylene glycol bis(allylcarbonate)] is about 1.50, whereas the refractive index of high index glass can range, for example, from 1.60 to 1.80. When fabricating lenses to correct a given visual defect, e.g., a correction for myopia, the use of a polymeric material having a lower refractive index will require a thicker lens relative to a material having a higher refractive index, e.g., high index glass. If the degree of correction required is substantial, e.g., in the case of severe myopia, a lens fabricated from a low index polymeric material can be so thick as to negate the benefit of reduction in weight obtained by use of a polymeric material. In addition, thick optical lenses are not aesthetically desirable.
It is known that polymeric materials having refractive indices greater than 1.50 can be prepared from monomers containing halogens and/or aromatic rings. However, many such higher index polymeric materials also have undesirably lower Abbe numbers (also known as nu-values). Lower Abbe numbers are indicative of an increasing level of chromatic dispersion, which is typically manifested as optical distortion at or near the rim of the lens.
More recently, polymeric materials, such as optical lenses, having a desirable combination of high refractive indices, e.g., 1.55 or higher, and high Abbe numbers, e.g., at least 27, have been prepared from the thermal polymerization of monomers having episulfide groups (also commonly referred to as thiirane groups). Polymeric materials prepared from the thermal curing of episulfide containing monomers are described in, for example, U.S. Pat. Nos. 5,945,504 and 5,807,975, and European Patent Application Nos. EP 874,016 A2, EP 928,802 A2 and EP 950,905 A2.
It would be desirable to develop new polyfunctional thiirane compounds. It would also be desirable that such newly developed polyfunctional thiiranes be useful as monomers in the preparation of polymerizates, e.g., optical lenses, having a combination of high refractive indices, e.g., refractive inidices of at least 1.6, and adequately high Abbe numbers, e.g., Abbe numbers of at least 27.
In accordance with the present invention, there is provided a polyfunctional thiirane selected from polyfunctional thiiranes represented by the following general formulas:
and mixtures of at least two of (i), (ii), (iii), (iv), (v), (vi), (vii), (viii), (ix), (x) and (xi);
wherein X is selected from S and O the number of functional groups (i.e., functional groups represented by the following general formula I,
wherein X is S constituting at least 50 percent of the total number of such functional groups present in said polyfunctional thiirane; and R
1
, R
2
and R
3
are each selected independently for each general formula from the group consisting of straight or branched chain alkylene (usually containing from 1 to 20 carbon atoms, e.g., 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms and more preferably 1 to 2 carbon atoms), cyclic alkylene (usually containing from 5 to 8 carbon atoms), phenylene and C
1
-C
9
alkyl substituted phenylene.
In accordance with the present invention, there is further provided a polymerizable composition comprising the polyfunctional thiirane as described above. In accordance with an embodiment of the present invention, a polymerizate of the polymerizable composition of the present invention has a refractive index of at least 1.6 (as determined in accordance with American Standard Test Method (ASTM) number D 542-95), and an Abbe number of at least 27 (as determined using an instrument, such as a Bausch & Lomb ABBE-3L Refractometer).
Unless otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, etc. used herein are to be understood as modified in all instances by the term “about.”
DETAILED DESCRIPTION OF THE INVENTION
While the functional groups of the polyfunctional thiirane of the present invention are preferably all thiirane groups, the polyfunctional thiirane may also contain epoxide groups. With reference to general formulas (i) through (xi), the polyfunctional thiirane of the present invention typically contains at least 50 percent of groups represented by general formula I wherein X is S, more typically at least 70 percent, preferably at least 90 percent, and more preferably 100 percent, based on the total number of functional groups of general formula I present in the polyfunctional thiirane or mixture of polyfunctional thiiranes. For example, the polyfunctional thiirane represented by general formula (i) may contain either two thiirane groups and one epoxide group, or preferably three thiirane groups.
The polyfunctional thiirane of the present invention may be prepared by art-recognized methods in which, for example, a polyfunctional epoxide intermediate is first formed from the reaction of a polythiol starting material and an epihalohydrin, e.g., epichlorohydrin. The epoxide groups of the polyfunctional epoxide intermediate are then converted to thiirane groups by reaction with a sulfurizing agent, e.g., thiocyanate, thiourea, triphenylphosphine sulfide or 3-methylbenzothiazole-2-thione, thereby forming the polyfunctional thiirane of the present invention. Typically, the sulfurizing agent used is either thiocycanate or thiourea. As the sulfurization reaction is not always 100 percent complete, some epoxide groups may not be converted to thiirane groups, and accordingly the resulting polyfunctional thiirane of the present invention may contain some epoxide groups, as described previously herein with reference to X of general formulas (i) through (xi).
Alternatively, the polyfunctional thiirane of the present invention may be prepared more directly in an art-recognized single step process that does not require a sulfurization step. In the single step process, the polyfunctional thiirane is formed from the reaction of a polythiol starting material with a 1-halo-2,3-ethylene sulfide, e.g., 1-chloro-2,3-ethyelene sulfide.
Each of the polyfunctional thiiranes represented by general formulas (i) through (xi) may be prepared as described previously herein from a corresponding polythiol starting material. For example, the polythiol starting materials that are reacted with either an epihalohydrin or 1-halo-2,3-ethylene sulfide in the preparation of the polyfunctional thiiranes represented by general formulas (i) and (viii), may be represented by the following general formulas II and III respectively,
wherein R
1
, R
2
and R
3
are as described previously herein.
The polythiol starting materials represented by general formulas II and III may be prepared by methods known in the art, for example, from an esterification or transesterification reaction between 3-mercapto-1,2-propanediol or 1,3-dimercapto-2-propanol respectively, and a thiol functional carboxylic acid or carboxylic acid ester in the presence of a strong acid catalyst, e.g., methane sulfonic acid, with the concurrent removal of water or alcohol from the reaction mixture. The preparation of polythio

Affiliated with

Also associated with

Rating

Polyfunctional thiirane compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Polyfunctional thiirane compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyfunctional thiirane compounds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3170314