Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From sulfur-containing reactant
Reexamination Certificate
2000-09-25
2002-07-09
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From sulfur-containing reactant
C528S374000, C528S377000, C528S483000, C528S487000, C523S427000, C523S428000, C359S642000
Reexamination Certificate
active
06417322
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to polymerizable compositions, polymerized resins, and in particular fast curing compositions at room temperature as well as to a polymerization process for making such resin.
The polymerized compositions and the polymerization process of the invention are particularly useful for making transparent optical articles such as lenses, prisms, optical fibers, filters or for making different types of substrates, such as information recording substrates.
The polymerizable composition and the polymerization process of the invention are also specifically suited for making various coatings and in particular coatings for optical applications.
(2) Description of the Prior Art
Transparent plastic materials are widely used in the optical field and particularly in the ophthalmic field for their lightness, high impact resistance.
Optically transparent plastic materials having a high refractive index n
D=
1.6 or even higher have been developed recently which render it possible to manufacture optical articles such as lenses of lower thickness for an equivalent corrective power (optical power).
EP 0.921.417 discloses a polymerizable composition comprising a sulfur-containing compound having at least one episulfide functionality, a compound having one ore more active hydrogen atoms in one molecule, at least one of the active hydrogen atoms being an active hydrogen atom other than hydrogen atom of SH group, and optionally a polymerization catalyst.
Among the cited polymerization catalysts are the phosphines. The disclosed phosphines include trialkylphosphines and tricycloalkylphosphines, triphenylphosphine, tribenzilphosphine, tri(alkylphenyl)phosphines, dialkyl and dicycloalkylphenylphosphines, alkyl and cycloalkyldiphenylphosphines, and chlorodiphenylphosphine.
Document EP 0.942.027 discloses a polymerizable composition comprising a (thio)epoxy compound having at least one intramolecular disulfide bond and a polymerization catalyst. Among the numerous polymerization catalysts that can be used, trialkylphosphines and triarylphosphines are cited.
Unfortunately, the polymerization of these polymerizable compositions needs a long thermal polymerization cycle, generally between 8 hours to 17 or more in order to obtain fully polymerized articles.
SUMMARY OF THE INVENTION
Thus, the aim of the present invention is to provide polymerizable compositions for making optically transparent resins which are thermally polymerizable and preferably polymerizable at room temperature in a short time cycle.
A further object of the invention is to provide polymerizable compositions as above which result in polymerizable resins having a high refractive index of 1.6 or more, and preferably of 1.7 or more.
The invention also concerns a polymerization process for making optically transparent resins which necessitates shorter time than the prior art processes.
The invention further concerns optical articles such as lenses made of the resins resulting from the polymerization of the polymerizable compositions.
It has now been discovered that, by using an effective amount of an alkoxyphenylphosphine as part of the catalyst or preferably as the sole catalyst in polymerizable compositions including at least one episulfide monomer, it was possible to use very short polymerization cycles while still obtaining a polymerized resin which is optically transparent and free of striations and having good mechanical, scratch and heat resistance properties.
According to the present invention, there is a risk provided thermally or room temperature polymerizable compositions for making optically transparent resins and comprising at least one polymerizable monomer having at least one episulfide functionality and an effective amount of a polymerization catalyst, comprising a phosphine having at least one alkoxyphenyl group. More specifically, the polymerization catalyst is selected from phosphines of formula (I):
and mixtures thereof, in which R and R′ are alkyl groups, x is an integer from 1 to 3, y is an integer from 1 to 3 and z in an integer from 0 to 2 with the proviso that x+z=3, t is 0, 1, 2 or 3.
Preferably, the catalyst consists solely in the (alkoxyphenyl)phosphine of formula (I) or a mixture of these phosphines.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
The (alkoxyphenyl)phosphine catalyst of formula (I) may comprise 1 to 3 alkoxy phenyl groups (x is 1, 2 or 3). The preferred (alkoxyphenyl)phosphine catalysts of formula (I) are tris(alkoxyphenyl)phosphines (i.e. :z=0)
The alkoxyphenyl groups of the phosphines of formula (I) may be monoalkoxy, dialkoxy or trialkoxyphenyl groups.
Preferably, the alkoxyphenyl groups are mono and dialkoxy groups, most preferably monoalkoxy groups.
The alkyl radical R in the alkoxy groups OR is generally selected from C
1
-C
6
alkyl groups, preferably C
1
-C
4
alkyl groups. Most preferably, R is CH
3
.
In mono alkoxyphenyl groups, the alkoxy group is usually in position 3 or 4 on the phenyl ring, preferably in position 4. In the dialkoxyphenyl group, the alkoxy groups are preferably in position 2 and 6 of the phenyl ring whereas in trialkoxyphenyl groups, the alkoxy groups are preferably in position 2, 4 and 6 on the phenyl ring.
The alkyl radical R′ is generally selected from C
1
-C
6
alkyl groups, preferably C
1
-C
4
alkyl groups, such as methyl, ethyl and propyl.
The most preferred phosphine catalysts are tris(monoalkoxy)phosphines.
Among the preferred alkoxyphenylphosphines of formula (I), there may be cited tris(3-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(2,6-dimethoxyphenyl)phosphine and tris(2,4,6-trimethoxyphenyl)phosphine. The most preferred phosphine is tris(4-methoxyphenyl)phosphine which gives the best compromise between a fast polymerization reaction and a non charring system.
The alkoxyphenylphosphine catalyst shall be used in the polymerizable compositions in an effective amount i.e. an amount sufficient to promote the polymerization, particularly the room temperature polymerization, of the composition.
The effective amount of phosphine catalysts will obviously depend upon the phosphine catalyst itself and the nature of the monomer or mixture of monomers of the composition in order to obtain a fast polymerization while avoiding charring of the system.
Generally, the phosphine catalyst will be present in amounts ranging, based on the total weight of the polymerizable monomers, from 5 to 1800 parts per million (ppm), preferably 100 to 800 ppm and more preferably 200 to 700 ppm.
Preferably, the phosphine catalyst is added to the monomer mixture as a solution in an appropriate solvent. Solvents that can be used are tetrahydrofuran (THF), chloroform, water, N-methyl-2-pyrrolidone (NMP) and N, N-dimethylacetamide (DMAC). Preferred solvents are THF, NMP and DMAC.
The polymerizable episulfide monomers of the invention have at least one episulfide functionality and preferably two ore more episulfide functionalities per molecule.
Preferably, the polymerizable monomers having at least one episulfide functionality are compounds having one or more episulfide structures represented by the following formula (II) in one molecule:
In which R
1
represents a hydrocarbon group having 1 to 10 carbon atoms, R
2
, R
3
and R
4
each represents an hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X represents S or O with the proviso that in the molecule the average number of S represented by X is about 50% of the total number of S and O constituting the three membered ring.
A preferred class of polymerizable episulfide monomer is represented by compound of formula (III):
in which R
5
, R
6
, R
7
, R
8
, R
9
and R
10
each represents an hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X represents S or O with the proviso that, in the molecule, the average number of S represented by X is about 50% or more of the total number of S and O constituting the three member rings, m represents an integer from 0 to 6 a
Ahmed Jallouli Aref Ben
Keita Gabriel
Turshani Yassin
Weber Steven
Essilor International Compagnie General d'Optique
Fulbright & Jaworski L.L.P.
Truong Duc
LandOfFree
Episulfide based polymerizable composition catalyzed by an... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Episulfide based polymerizable composition catalyzed by an..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Episulfide based polymerizable composition catalyzed by an... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2826894