Copolymer compositions are prepared from a novel class of siloxane monomers in combination with hydroxyperfluoroalkylstyrenes, preferably p-(2-hydroxy hexafluoroisopropyl)sytrene [HFIS] monomer for ophthalmic applications.

BACKGROUND OF THE INVENTION 
The present invention relates to a copolymer composition which employs a 
class of novel siloxane monomers containing both an aromatic ring and 
vinyl functionality, as a monomer for preparing copolymers in combination 
with p-(2-hydroxy hexafluoroisopropyl)styrene (HFIS). Copolymers 
comprising variable amounts of the monomers are transparent to visible 
light, have a high refractive index, and are useful, inter alia in 
fabricating lenses, especially contact lenses and intracameral devices 
such as corneal inserts and intraocular implants. Contact lenses comprise 
generally fillerless, oxygen transportable hydrolytically stable, 
biologically inert, transparent plastic bodies which are prepared from 
polymerization, or copolymerization of monomers. The novel class of 
siloxane monomers containing both an aromatic ring and vinyl functionality 
are the subject of our copending commonly assigned application, Ser. No. 
801,259, filed Nov. 25, 1985, now U.S. Pat. No. 4,633,003 Park and 
Falcetta, and entitled NEW SILOXANE MONOMERS FOR OPHTHALMIC APPLICATIONS. 
The copolymers of this invention which contain this monomer are optically 
clear and colorless. 
The polymers and copolymers described herein can be usefully employed for 
making "hard" or "soft" contact lenses, intraocular implants, intracorneal 
implants, semisoft contact lenses, as well as in other biomedical 
applications. Importantly, the copolymers of this invention, that is the 
combination of the novel class of siloxane monomers of Ser. No. 801,259 
and HFIS, are especially adapted for, and suitable in, making hard gas 
permeable contact lenses, with the HFIS contributing to wettability 
without any negative impact on oxygen permeability. In fact, oxygen 
permeability is enhanced. The copolymers may also have other uses such as 
permeable films, etc., but the primary description given will emphasize 
lens utility. 
Hard contact lenses have the advantages of excellent machinability, 
excellent stability, and excellent visual clarity. However, hard contact 
lenses have their disadvantages, as well. Generally for many, including 
the most common hard lenses, i.e. those made of polymethyl methacrylate 
(PMMA), oxygen permeability is low and the hydrophilic properties are 
poor. 
It is important and essential that the cornea have access to atmospheric 
oxygen in order that an oxygen-carbon dioxide exchange can occur. Put 
another way, without constant eye exposure to the atmosphere, a state of 
oxygen edema can occur within the eye, which is potentially capable of 
causing damage. Thus, hard contact lenses, while having many practical 
advantages, generally are not altogether satisfactory because they most 
often have poor oxygen permeability. 
A good hard contact lens would have not only excellent oxygen permeability, 
but also excellent tear-fluid wettability. Wettability is important in 
that if the lens is not wettable it cannot be comfortably worn in the eye. 
The patient will perceive the lens as uncomfortable and scratchy, absent 
good wettability. 
Generally, in the past, polymer formulation for optical lens products has 
involved an initial determination as to whether one was formulating either 
a hard lens or a soft lens, followed by formula manipulation within a 
distinctly different class of monomers useful for one type, but not 
necessarily useful for the other. As explained in our co-pending earlier 
referenced application Ser. No. 801,259, it has now been found possible to 
make contact lenses, involving as a siloxane monomer ingredient of 
variable presence, a monomer which can be adapted for making either hard 
or soft lenses. In this present invention, the novel class of siloxane 
monomers is combined with a comonomer of preferred HFIS or other 
hydroxyfluoroalkylstyrene, which contributes both wettability and oxygen 
permeability. 
Indeed, it is an object of the present invention to provide in combination 
with our earlier described class of novel siloxane monomers which have 
both an aromatic ring functionality and vinyl functionality at certain 
stereo-directing positions, a hydroxyfluoroalkylstyrene such as 
p-(2-hydroxy hexafluoroisopropyl)styrene (HFIS), resulting in copolymers 
useful as materials for making a wide variety of types of optical 
products, especially gas permeable contact lenses and ocular implants. 
A further object of the invention is to provide a copolymer combination of 
the type specifically mentioned above which is not only of good oxygen 
permeability, but which is highly compatible with other monomers, and 
which, when copolymerized with other minor monomers provides wettability, 
without sacrificing oxygen permeability. 
A still further object of the present invention is to provide hard gas 
permeable contact lenses which contain as a main ingredient of variable 
presence, the hereinafter defined combination of monomers of the present 
invention. 
A still further object of the present invention is to provide 
hydroxyfluoroalkylstyrenes such as the preferred HFIS as a monomer for use 
in biomedical lens devices to improve wettability, without any significant 
impact on oxygen permeability. 
A further object of the present invention is to provide a copolymerizable 
compound suited for preparing contact lenses which have good oxygen 
permeability, are machineable, and which can be used with or without other 
minor monomer modifiers for hard gas permeable contact lenses which can be 
comfortably worn. 
A still further object of the present invention is to prepare a copolymer 
combination which can be copolymerized with or without other minor, 
modifying monomers to provide a copolymer useful for optical products, 
particularly gas permeable hard contact lenses, wherein the copolymer has 
a DK, i.e. oxygen permeability constant value within the range of from 
about 12 to about 70, and which also has a highly wettable surface. Such 
lenses are comfortable, when worn show no evidence of substantial corneal 
edema, are of good machineability, are dimensionally stable, are tear 
wettable, and as well have sufficient lipophilicity to optimally interact 
with tear fluid. 
The method and means of accomplishing each of the above objectives, as well 
as others will become apparent from the detailed description of the 
invention which will follow hereinafter. 
SUMMARY OF THE INVENTION 
Certain siloxane monomers which contain both an aromatic ring functionality 
and vinyl functionality are combined with hydroxyfluoroalkylstyrenes, 
preferably HFIS. The siloxane monomers in combination with 
hydroxyfluoroalkylstyrenes such as HFIS provide copolymer combinations 
useful for making gas permeable hard contact lenses, and other optical 
products. The new copolymer combinations of the present invention provide 
excellent oxygen permeability without adversely impacting other desirable 
properties such as machineability, wettability, lipophilicity, and 
dimensional stability. Moreover, the copolymers are useful for making 
lenses which are substantially inert to the eye and transparent, provide 
good visual clarity and sharpness of image. The monomers may be used alone 
or in combination with other minor, modifying monomers. The invention also 
relates to the use of hydroxyfluoroalkylstyrenes such as HFIS in all types 
of polymer compositions useful for making biomedical devices, especially 
lenses of improved wettability without adverse impact of oxygen 
permeability. 
DETAILED DESCRIPTION OF THE INVENTION 
It has now been found that the above-mentioned objects, as well as others, 
can be obtained by a combination of the novel class of siloxane monomer 
compound of the incorporated by reference parent application Ser. No. 
801,259, and a hydroxyfluoralkylstyrene, preferably p-(2-hydroxy 
hexafluoroisopropyl) styrene, hereinafter referred to as HFIS. The monomer 
compound of the parent application containing both an aromatic ring and 
vinyl functionality, has the following formula (I): 
##STR1## 
where 
(1) "A" is selected from the group consisting of: 
##STR2## 
where m is a number and is from 2-4; 
(2) R is hydrogen or methyl; 
(3) X and Y are selected from the group consisting of C.sub.1 to C.sub.5 
alkyl groups, phenyl groups and W groups; 
(4) W is a group of the structure 
##STR3## 
(5) Z is selected from the group consisting of C.sub.1 to C.sub.5 alkyl 
groups and phenyl groups; and 
(6) n is an integer from zero to five. 
It is not known precisely why the monomer of the parent application has a 
wide range of other monomer compatability, allowing it to be useful in 
making either hard or soft contact lenses, but it does. As explained in 
the parent application, without being bound to any theory, it is believed 
that perhaps its wide compatability is achieved because within the 
structure there is a synergistic relationship between the unique 
combination of functional groups and their spatial relationship to each 
other, giving the desirable properties. It is believed the presence of the 
aromatic ring contributes to a desirably higher index of refraction, on 
the order of 1.4515; the presence of the siloxane moiety provides for 
oxygen permeability; and, the presence of the vinyl functionality provides 
for good overall polymerization properties, without adversely impacting 
other desirable properties, especially oxygen permeability. 
The novel siloxane monomer of the parent application, useful in the 
combination copolymer of this invention is prepared in a relatively 
straightforward, easy to perform, series of reactions, summarized by a 
synthetic scheme, starting with chloromethyl styrene, as depicted in the 
earlier referenced parent application Ser. No. 801,259. The synthesis need 
not, therefore, be repeated here. 
The hereinafter description will be given with reference to the most 
preferred hydroxyfluoroalkylstyrene, HFIS, but it is to be understood that 
others coming within the scope of this invention may also be used. In 
accordance with this invention HFIS, or chemically p-(2-hydroxy 
hexafluoroisopropyl)styrene, may be added as a comonomer to other 
conventional monomer compositions in preparing a hard gas permeable lens 
of improved wettability. Importantly, the HFIS improves wettability 
without any significant adverse impact on oxygen permeability. The amount 
of HFIS employed may vary within the range of from about 10% by weight of 
the total monomer composition to about 60% by weight of the total monomer 
composition. In one preferred hard gas permeable lens composition of the 
present invention HFIS may be employed at the levels previously specified 
in combination with the novel class of siloxane monomers of the parent 
application, with the siloxane monomer being present at from about 25% by 
weight of the composition to about 50% by weight of the composition. Thus, 
the HFIS monomer of the present invention can be successfully employed as 
a monomer for preparing copolymers useful as a transparent material for 
gas permeable hard contact lenses, with or without being combined with the 
siloxane monomer invention of the parent application. 
When the compound of the invention is copolymerized with other particular 
comonomers, there can be obtained copolymers suitable for use with contact 
lenses which have excellent oxygen permeability, affinity for the cornea, 
and can be continuously worn, long term, without giving a foreign body 
sensation. For instance as previously explained, when from about 25% by 
weight to about 50% by weight formula [I] siloxane monomer of the parent 
application invention is copolymerized with from about 10% by weight to 
about 40% by weight of a comonomer hydroxyflouroalkylstyrene compound, 
preferably HFIS, which also improves wettability, good polymeric 
compositions for hard gas permeable lenses result. 
As those of ordinary skill in the art of polymer formulation for optical 
lens materials know, it is common to use other monomers at various levels 
of addition, besides the main comonomers in a composition. Those other 
formulation ingredients are herein referred to as minor modifying 
monomers. The term minor is from the standpoint of percentage in 
comparison with the amount of the siloxane monomer of formula I and the 
hydroxyfluoroalkylstyrene monomer such as HFIS in total, and does not mean 
minor in significance. In the lens modifications of this invention, minor 
modifying monomers may include from about 0% by weight to about 40% by 
weight of a compatible mechanical property modifier such as methyl 
methacrylate, tertiary butyl styrene or cyclohexyl methacrylate, from 
about 0% by weight to about 5% by weight of a hydrophilic wetting agent 
monomer such as methacrylic acid, and from about 0.5% by weight to about 
2% by weight of a cross-linker such as ethyleneglycol dimethacrylate, an 
excellent hard gas permeable contact lens is achieved. 
As those skilled in the art know, the copolymerization reactions mentioned 
herein typically occur in the presence of a radical polymerization 
initiator such as azobisisobutyronitrile or azobisdimethylvaleronitrile by 
means of a bulk polymerization reaction. 
In one particularly preferred formulation for a hard gas permeable lens 
which has been found especially suitable, the lens formulation includes 
35% of the pentatris-siloxane monomer of the parent application, 10% of 
the tris-ureido siloxane monomer species of the parent application, 23% of 
HFIS, 30% of methylmethacrylate as a physical property modifier, and 2% of 
ethylene glycol dimethacrylate cross-linker. 
Heretofore, particular reference has been made to the most preferred 
fluorostyrene monomer of the present invention, HFIS. It should be 
understood, however, that other fluorostyrenes generally of the types 
disclosed in U.S. Pat. No. 3,179,640 can be used herein. The disclosure of 
U.S. Pat. No. 3,179,640, patented Apr. 20, 1965, to the extent of its 
general description of fluorostyrene monomers, their formulas and their 
methods of preparation is specifically incorporated herein by reference. 
The styrenes shown in that patent have the following general formulation: 
##STR4## 
wherein X and Y are, individually, the same or different monovalent 
polyfluoroalkyl, including perfluoroalkyl, .omega.-hydroperfluoroalkyl and 
.omega.-chloroperfluoroalkyl, radicals, or jointly, a divalent 
perfluoroalkylene radical. There is, however, no disclosure of any utility 
of those monomers in the incorporated-by-reference U.S. Pat. No. 3,179,640 
as useful in polymeric compositions for biomedical devices, in particular, 
as monomers or copolymers for use in preparation of ophthalmic lenses, and 
in particular contact lenses. The preferred alkyl group is C.sub.1 to 
C.sub.8, and most preferred is C.sub.1 to C.sub.3. 
The monomer, p-(2-hydroxy hexafluoroisopropyl)stryene [HFIS] has been 
described in U.S. Pat. No. 3,179,640 as a monomer which yields polymers 
having unusual swelling properties. Thus, while the monomer has been known 
for many years it has never been used in biomedical applications and 
specifically in ophthalmic applications. It has the formula: 
##STR5## 
The following properties of HFIS make it the most preferred 
hydroxyfluoroalkylstyrene compound for use in copolymers intended for 
biomedical applications and specifically for ophthalmic applications in 
accordance with this invention. The pKa of HIFS is .about.5.5 compared to 
the .about.4.8 found with acrylic acid type comonomers. The index of 
refraction (n.sub.D.sup.25) of HFIS is 1.4577 compared to 1.4290 for 
methacrylic acid. The oxygen permeability (DK) of the homopolymer is 
2.3.times.10.sup.-11. The presence of the fluorine substituents may 
significantly reduce interaction with biological fluids such as tears. The 
homopolymer has a contact angle of 18.degree. as measured by the captive 
bubble technique, which compares with contact angle of 37.degree. under 
the same conditions for a commercial gas permeable hard lens. 
Using HFIS one can obtain wettable polymers containing no methacrylic acid 
or a substantially reduced amount of methacrylic acid. These copolymers 
will have an improved oxygen permeability over copolymers containing 
methacrylic acid. A further desirable feature is that for given optical 
parameters, a thinner contact lens can be made due to the higher index of 
refraction of HFIS containing copolymers. This is advantageous since 
thinner contact lenses have improved physiological response and improved 
oxygen transport. 
Generally, characterization of a contact lens as hard or soft will depend 
upon the minor modifying monomers polymerized with the 
hydroxyfluoroalkylstyrene monomers of the present invention. Other 
hydrophilic comonomers which may be incorporated to provide increased 
wettability, such as alkoxyacrylates. Other comonomers useful for making 
hydrogel type soft lenses and hard lenses include the hydroxy alkyl 
acrylates and methacrylates; hydroxyethyl methacrylate (HEMA), 
hydroxyethyl acrylate, hydroxy-polyethoxy ethyl methacrylate and the like. 
Examples of another class of suitable hydrophilic monomers are the N-vinyl 
heterocyclic monomers, suitable examples of such monomers being N-vinyl-2 
pyrrolidone, N-vinyl pyridine and N-vinyl-.epsilon.-caprolactam. Also 
another class of hydrophilic monomers are the polymerizable olefinic acids 
and amides; suitable examples being acrylic acid, methacrylic acid, 
itaconic acid, fumaric acid, maleic acid, crotonic acid, acrylamide, 
methacrylamide and N-(1,1-dimethyl-3-oxobutyl acrylamide). Another 
suitable group of hydrophilic monomers are the lower alkyl vinyl ethers 
such as methyl and ethyl vinyl ether. 
Other compatible mechanical property modifying monomers can be utilized to 
change the softening temperature and hardness and to improve 
machineability of the copolymer. Generally, these are somewhat hydrophobic 
monomers and preferred are the olefinically unsaturated polymerizable 
monomers with one polymerizable double bond per molecule. Suitable 
examples of such monomers are the linear or branched C.sub.1 to C.sub.10 
alkyl esters of acrylic and methacrylic acid such as methyl acrylate, 
ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl 
methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl 
methacrylate, 2-ethylhexyl methacrylate, 2-ethoxyethyl methacrylate, and 
the like monomers. Examples of other suitable hydrophobic monomers useful 
as compatible mechanical property modifiers are the vinyl ethers such as 
butyl vinyl ether and vinyl acetate, vinyl chloride, vinyl propionate, 
isoprene, vinyl carbazole, and styrene monomers other than those defined 
above for the main monomer which are styrenes, including alkoxy styrenes, 
e.g., methoxy and ethoxy sytrene, halogenated styrenes, hydroxyalkyl 
styrenes, alkoxy alkyl styrenes, and polyalkoxyether sytrenes. 
As heretofore mentioned, certain ranges of cross-linking monomers may also 
be employed. These may be used to harden the resulting copolymer or to 
improve machineability or stability, or both. Examples of suitable 
cross-linking monomers are divinyl benzene, di- and higher functionality 
of methacrylates and acrylates such as ethylene glycol dimethacrylate, 
tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 
trimethylol propane trimethylacrylate, pentaerythritol tetramethacrylate, 
and allyl methacrylate, allyl itaconate, diallyl itaconate, diallyl 
adipate and methylenebisacrylamide. The foregoing examples of 
cross-linking monomers are merely illustrative, others may also be used, 
and all may be used individually, or in combination. 
While preferred polymerized compositions of this invention would include a 
siloxane formula [I] monomer of our parent application, and typically one 
other compatible comonomer, a wetting agent and a cross-linking agent, 
other minor modifying ingredients may also be added in making suitable 
buttons or bonnets. Such minors include coloring agents, light absorbers, 
certain other mechanical properties such as plasticizers and the like, so 
long as those other materials do not adversely effect the desired 
properties of main copolymerizable monomers of the invention and lenses 
made therefrom. One does not have to use the formula [I] siloxane, and 
this invention broadly contemplates the hereinbefore described 
hydroxyperfluoroaklylstyrenes as wetting agent monomers in any lens 
formulations. 
The contact lenses can be formed from the copolymer by any of the 
conventional lens lathing molding and/or polishing processes. For example, 
the polymers can be formed into rods which are cut into small cylinders or 
disks, often referred to as buttons or bonnets, from which the contact 
lens can be machined. 
The wearing comfort of the contact lenses of the gas permeable hard lens 
type can be enhanced by the use of wellknown wetting solutions, cleaners, 
disinfectant solutions, comfort drops, and the like.

The invention will be further described in connection with the following 
examples which are given for purposes of illustration and should not be 
construed as limiting on the invention. All parts and percents referred to 
herein are on a weight basis. 
EXAMPLES 
Example 1 
Synthesis of tris (trimethylsiloxy) silane-m,p-chloromethyl phenylethane 
A catalyst solution is prepared by adding, with stirring, 23.8 g. of 
concentrated sulfuric acid to a solution of 11.6 g. of ethanol in 16.5 ml 
of distilled water. 
To a 500 ml round bottom flask that is situated on an ice batch, a mixture 
of 43.6 g. (0.33 mole) of trimethylacetoxysilane and 27.4 g. (0.1 mole) of 
trimethoxysilane-m,p-chloromethyl) phenylethane is added. To this mixture 
9.1 ml of the catalyst solution is added in a dropwise manner over a time 
period of 30 minutes. 
The reaction mixture is vigorously stirred for three days at room 
temperature. After separation, the organic layer is neutralized with 
sodium bicarbonate, washed with water and dried over magnesium sulfate. 
A yield of 31 g. (69.2%) of a slightly yellow liquid having an index of 
refraction of 1.4515 is obtained at 120.degree.-135.degree. C. (0.3-0.4 
mm). 
The identity of the compound was confirmed by the infrared spectrum and nmr 
spectrum [7.1 ppm (m,4H); 0.0 ppm (s,27H)]. 
Example 2 
Synthesis of tris (trimethylsiloxy) 
silane(m,p-methacryloxymethyl)phenylethane 
A mixture of 13.4 g. (3.0 mmole) and 3.6 g. (3.3 mmole) of sodium 
methacrylate in 150 ml of dimethylformamide was stirred at 125.degree. C. 
for one hour. After cooling with an ice bath, 100 ml of distilled water 
was added. This reaction mixture was then extracted four times with 100 ml 
volumes of ethyl acetate. The combined organic layer is washed 3 times 
with 50 ml of a saturated sodium chloride solution and dried over 
anhydrous magnesium sulfate. After stripping off the low boiling 
components by vacuum distillation the final product was obtained at 
120.degree.-129.degree. C. (0.1 mm) in a yield of 53.4%. 
The identity of the compound was proven by the infrared spectrum and nmr 
spectrum [7.1 ppm (m,4H), 6.0 and 5.4 ppm (2 broad s,2H), 0.0 ppm 
(s,27H)]. 
Example 3 
Synthesis of tris (pentamethyl disiloxy) 
silane(m,p-methacryloxymethyl)phenylethane [Penta Tris Styrene] 
Using a procedure similar to that given in Examples 1 and 2, 
trimethoxysilane(m,p-chloromethyl) phenylethane was reacted with 
pentamethylacetoxy-disilane to form tris (pentamethyl 
disiloxy)-(m,p-chloromethyl) phenylethane in 44% yield. This compound was 
then reacted with sodium methacrylate in dimethylformamide solution to 
give a 83.9% yield of tris (pentamethyl disiloxy) 
silane-m,p-methacryloyloxymethyl phenylethane. 
The identity of the compound was confirmed by the infrared spectrum; 1730 
cm.sup.-1 (C.dbd.O), 1640 cm.sup.-1 (CH.sub.2 =), 1615 cm.sup.-1 
(aromatic) and 1070 cm.sup.-1 (Si--O--) and nmr spectrum; 7.1 ppm (m,4H); 
5.9 and 5.3 ppm (2 broad s,2H); 1.8 ppm (s,3H); 0.0 ppm (broad s,45H). 
Example 4 
Synthesis of 
trimethylsiloxy-dimethylsilane(m,p-methacryloxymethyl)phenylethane 
Trimethylsiloxyl-dimethylsilane(m,p-chloromethyl)phenylethane was 
synthesized by the reaction of pentamethyldisiloxane and vinyl benzyl 
chloride in the presence of chloroplatinic acid. This compound was then 
reacted with sodium methacrylate in dimethylformamide using procedures 
similar to those given in Example 2 to form trimethylsiloxy-dimethylsilane 
(m-p-methacryloxymethyl)phenylethane in a 50.7% yield. [B.P. 102.degree. 
C. (0.1 mm)]. 
The identity of the compound was confirmed by the infrared spectrum; 1730 
cm.sup.-1 (C.dbd.O), 1640 cm.sup.-1 (CH.sub.2 .dbd.), 1615 cm.sup.1 
(aromatic) 1070 cm.sup.-1 (Si--O--) and the nmr spectrum; 7.1 ppm (m,4H); 
5.9 and 5.3 ppm (broad s,2H), 5,0 ppm (s,2H), 0 ppm (2s,15H). 
Example 5 
Synthesis of bis (trimethylsiloxy) 
methylsilane(m,p-methacryloxymethyl)phenylethane 
Using the procedure set forth in Example 4, bis (trimethylsiloxy) 
methyl(m,p-methacryloxymethyl)phenylethane was prepared in a yield of 
54.7%. [B.P. 104.degree.-124.degree. C. (0.1-0.2 mm)]. 
The identity of the compound was confirmed by the infrared spectrum; 1730 
cm.sup.-1 (C.dbd.O), 1640 cm.sup.-1 (CH.sub.2 .dbd.), 1070 cm.sup.-1 
(Si--O--) and the nmr spectrum; 7.1 ppm (m,4H); 5.9 and 5.4 ppm (2 broad 
S,5H), 5.0 ppm (s,2H), 1.8 ppm (s,3H), 0 ppm (2s,21H). 
Example 6 
Synthesis of Tris (trimethylsiloxy) 
silane(m,p-3-N-methacryloxymethylureido-1-N-methyl)phenylethane [Tris 
Urea] 
Tris (trimethylsiloxy) silane(m,p-azidomethyl)phenyl ethane was prepared by 
the reaction of 17.9 g. (40 mmole) with 2.80 g. (44 mmole) of sodium azide 
in 100 ml of methanol under reflux for four hours. After evaporation and 
washing with 100 ml of distilled water the residue was extracted three 
times with 100 ml of distilled water the residue was extracted three times 
with 100 ml portions of ethyl acetate. The combined extracts were washed 
twice with 50 ml distilled water each time, dried over anhydrous magnesium 
sulfate and evaporated in vacuo. The reaction product was obtained in 
96.6% yield (17.2 g.), b.p. 120.degree.-125.degree. C. (0.4 mm). 
Tris (trimethylsiloxy) silane(m,p-aminomethyl)phenylethane was prepared by 
the catalytic hydrogenation of tris (trimethylsiloxy) 
silane(m,p-azidomethyl) phenylethane. 
To a Parr hydrogenation apparatus (500 ml capacity) were added, 16.3 g. (36 
mmole) of tris (trimethylsiloxy) silane(m,p-azidomethyl)phenylethane, 2.6 
g. acetic acid, 250 ml isopropanol and 0.87 g. of 5% palladium/charcoal. A 
cycle of hydrogenation at 5 psi for 15 min., evacuation and hydrogenation 
at 5 psi for 15 min. is repeated twice. The reaction mixture is filtered 
with the aid of Celite and the low boiling organics evaporated. The 
resulting liquid is treated with a 50:50 mixture of 5% aqueous sodium 
carbonate: ethyl acetate and the organic layer is then dried over 
anhydrous sodium sulfate. Vacuum distillation yields 10.8 g. (70.7% yield) 
of tris (trimethylsiloxy) silane(m,p-aminomethyl) phenylethane, b.p. 
145.degree.-155.degree. C. (0.1 mm). 
The identity of the compound was confirmed by the infrared spectrum; 3350 
cm.sup.-1 (NH.sub.2), 1070 cm.sup.-1 (Si-O) and nmr spectrum; 7.0 ppm 
(m,4H), 3.8 ppm (s,2H), 1.6 ppm (s,2H), 0 ppm (s,27H). 
Compound tris (trimethylsiloxy) silane(m,p-aminomethyl) phenylethane was 
then prepared from the reaction of tris (trimethylsiloxy) 
silane(m,p-aminomethyl)phenylethane with isocyanoethyl methacrylate. 
Compound tris (trimethylsiloxy) silane(m,p-aminomethyl)phenylethane (22.0 
g., 51 mmole) was reacted with 10.6 g. (68 mmole) of isocyanoethyl 
methacrylate in 110 ml methylene chloride in the presence of 
2.5-diphenyl-p-benzoquinone as an inhibitor. The isocyanoethyl 
methacrylate is added dropwise over a period of 30 minutes with stirring 
while the reaction mixture is cooled by an ice bath. At the end of this 
time the ice bath was removed and the reaction proceeded at room 
temperature for an additional 5.kappa. hours. Concentrated ammonium 
hydroxide (2 ml) is then added. The organic layer is then washed with 40 
ml distilled water three times and dried over anhydrous magnesium sulfate. 
Silica gel column separation with ethyl acetate-hexane as the eluent 
yielded 19.4 g. (65.0%) of tris (trimethylsiloxy) 
silane(m,p-3-N-methacryloxy-methylureido-1-N-methyl)phenylethane. 
The identity of the compound was confirmed by the infrared spectrum; 3380 
cm.sup.-1 (NH), 1730 cm.sup.-1 (C.dbd.O), 1580 cm.sup.-1 (NHCO), 1070 
cm.sup.-1 (--Si--O) and the nmr spectrum; 7.0 ppm (m,4H), 5.8 and 5.3 ppm 
(2s,2H), 4.8 ppm (m,2H), 4.1 ppm (m,4H), 3.3 ppm (5,2H), 1.8 ppm (s,3H), 0 
ppm (s,27H). 
Example 7 
Synthesis of tris (trimethylsiloxy) 
silane(m,p-N-methacrylaminomethyl)phenylethane 
Methacryloyl chloride (2.92 g., 28 mmole) is added dropwise over a period 
of thirty minutes to a solution of 10.0 g. (23 mmole) of compound tris 
(trimethylsiloxy) silane(m,p-aminomethyl)phenylethane and 2.83 g. (28 
mmole) triethylamine in 100 ml of chloroform on an ice bath. A trace 
amount of 2,5-diphenyl-p-benzoquinone is added as an inhibitor. After the 
addition of methacryloyl chloride is complete, the ice bath is removed and 
the reaction continued for a total of six hours. Concentrated ammonium 
hydroxide (2 ml) is then added. The organic layer is then washed with 40 
ml distilled water three times and dried over anhydrous magnesium sulfate. 
Vacuum distillation was then employed to obtain a 38% yield of tris 
(trimethylsiloxy) silane(m,p-N-methacrylaminomethyl)phenylethane [b.p. 
170.degree.-175.degree. C. (0.15 mm)]. 
The identity of the compound was confirmed by the infrared spectrum; 3350 
cm.sup.-1 (NH), 1670 and 1640 cm.sup.-1 (NHCO), 1070 cm.sup.-1 (SI--O--) 
and nmr spectrum; 7.0 ppm (m,4H), 6.0 ppm (broad, 1H), 5.5 and 5.2 ppm (2 
broad s,2H),4.3 ppm (2s,2H), 1.8 ppm (s,3H), 0 pp, (s,27H). 
Examples 8 through 10 
Using the reactions described in Examples 1 through 7, the monomers shown 
in Table I were prepared: 
TABLE I 
__________________________________________________________________________ 
Example # 
Monomer nmr data 
__________________________________________________________________________ 
8 bis (trimethylsiloxy)methylsilane- 
7.1 ppm (m,4H) 
( .sub.--m, .sub.--p-N--methacryloylaminomethyl)phenyl- 
5.6 & 5.3 ppm (2s,2H) 
ethane 
9 bis (trimethylsiloxy) methylsilane( .sub.--m, .sub.--p- 
7.0 ppm (m,4H) 
3-N--methacryloxyethylureido-1-N--methyl) 
6.0 & 5.5 ppm (2s,2H) 
phenylethane 4.8 (Broad D.sub.2 O 
exchangable) 
4.2 & 4.1 ppm (2t,4H) 
3.3 ppm (t,2H) 
0 ppm (2s,21H) 
10 tris (pentamethyldisiloxy) silane( .sub.--m, .sub.--p- 
7.0 ppm (m,4H) 
3-N--methacryloxyethylureido-1-N--methyl) 
5.9 & 5.7 ppm (2 broad 
phenylethane s,2H) 
1.8 ppm (s,3H) 
__________________________________________________________________________ 
Examples 11 through 14 
Copolymer Films 
Films of the copolymers listed in Table II were prepared between (4.times.4 
in.) glass plates. The glass plates were pretreated with 
dimethyldichlorosilane and hydrolyzed to silanize the surface. Masking 
tape is placed around the edges of a glass plate to control the film 
thickness (target thickness was usually 0.1 mm). The monomer mix was 
placed on a glass plate, the two plates secured together by means of a 
metal clip and the assembly placed in an oven at 50.degree. C. for one and 
one half hour. At the end of this time the glass plate assembly was heated 
to 90.degree. C. for an additional 90 minutes. The thin film was then 
removed from the glass plate assembly and stored in distilled water 
(phosphate buffer, pH 7.4). For all of the copolymers listed in Table II, 
1.0 weight % of USP 245 (2,5-dimethyl-2,5-diperoxy-2'-ethylhexoate hexane) 
was added. 
The composition of each copolymer in mole percent is: siloxane monomer 
16.2%, methyl methacrylate 76.9%, methacrylic acid 5.4% and ethylene 
glycol dimethacrylate 1.5%. 
Oxygen permeability (DK) was measured in a water/water cell using an 
O.sub.2 Permeometer.TM. Model 101T. The units of DK are cm.sup.2 /sec 
(mlO.sub.2 /ml mmHg).times.10.sup.11. 
TABLE II 
______________________________________ 
Example # 
Copolymer based on DK 
______________________________________ 
11 tris (pentamethyl disiloxy) silane- .sub.--m, .sub.--p- 
54 
methacryloyloxymethyl phenylethane 
12 tris (trimethylsiloxy) silane - .sub.--m, .sub.--p- 
18 
methacryloxymethyl phenylethane 
13 pentamethyldisiloxy- .sub.--m, .sub.--p-methacryloxy- 
8 
methyl phenylethane 
14 bis (trimethylsiloxy) methyl- .sub.--m, .sub.--p-meth- 
2.4 
acryloyloxymethyl phenylethane 
______________________________________ 
Example 15 
Copolymerization of tris (trimethylsiloxy) 
silane(m,p-methacryloxymethyl)phenylethane with methyl methacrylate and 
methacrylic acid 
Tris (trimethylsiloxy) silane(m,p-methacryloxymethyl) phenylethane 3.84 g. 
was added to a clean, dry 20 ml glass, screw top test tube along with 3.62 
g. methyl methacrylate, 0.39 g. methacrylic acid, 0.16 g. ethyleneglycol 
dimethacrylate and 0.09 g. USP 245. After degassing with Argon the tube 
was capped and placed in an oil bath at 50.degree. C. for one hour and 
then at 70.degree. C. for 72 hours. It was then carried through an 
annealing cycle at 120.degree. C. A hard, transparent button was obtained 
that could be machined to a contact lens using standard lathing and 
polishing techniques. The contact lens thus obtained has a DK of 18. 
The following table summarizes some of the monomers which have been or can 
be prepared in accordance with the invention. 
TABLE III 
__________________________________________________________________________ 
Compound Name A R X Y Z n 
__________________________________________________________________________ 
tris(trimethylsiloxy)- 
Ester 
Methyl 
-OSi(CH.sub.3).sub.3 
* -CH.sub.3 
1 
silane-(m,p-methacryloxy- 
methyl)-phenylethane 
tris(pentamethyl disiloxyl 
Ester 
Methyl 
-OSi(CH.sub.3).sub.2 
OSi(CH.sub.3).sub.3 * 
-OSi(CH.sub.3).sub.3 
1 
silane-(m,p-methacryloxy- 
methyl)phenylethane 
tris(trimethylsiloxy)- 
Amide 
Methyl 
-OSi(CH.sub.3).sub.3 
* -CH.sub.3 
1 
silane-(m,p-N--methacryl- 
aminomethyl)phenylethane 
bis(trimethylsiloxy)methyl- 
Amide 
Methyl 
-CH.sub.3 
OSi(CH.sub.3).sub.3 
-CH.sub.3 
1 
silane-(m,p-N--methacryl- 
aminomethyl)phenylethane 
bis(trimethylsiloxy)methyl- 
Ester 
Methyl 
-CH.sub.3 
OSi(CH.sub.3).sub.3 
-CH.sub.3 
1 
silane-(m,p-methacryloxy- 
methyl)phenylethane 
trimethylsiloxy-dimethyl- 
Ester 
Methyl 
-CH.sub.3 
* -CH.sub.3 
1 
silane-(m,p-methacryloxy- 
methyl)phenylethane 
tris(pentamethyl disiloxyl 
Urea, 
Methyl 
-OSi(CH.sub.3).sub.2 
OSi(CH.sub.3).sub.3 * 
-OSi(CH.sub.3).sub.3 
1 
silane-(m,p-3-N--methacryl- 
m = 2 
oxymethylureido-1-N--methyl)- 
phenylethane 
tris(trimethylsiloxy)- 
Urea, 
Methyl 
-OSi(CH.sub.3).sub.3 
* -CH.sub.3 
1 
silane-(m,p-3-N--methacryl- 
m-2 
oxymethylureido-1-N--methyl)- 
phenylethane 
bis(trimethylsiloxy)methyl- 
Urea, 
Methyl 
-CH.sub.3 
OSi(CH.sub.3).sub.3 
-CH.sub.3 
1 
silane-(m,p-3-N--methacryl- 
m = 2 
oxymethylureido-1-N--methyl)- 
phenylethane 
__________________________________________________________________________ 
*Y and X are the same. 
Example 16 
Films of the copolymers used in this example, which employ HFIS as the 
perfluoro styrene compound, were prepared in accordance with the details 
for preparation of films specified in earlier examples 11-14. In these 
instances, the siloxane monomer used in the copolymer combination was tris 
(trimethylsiloxy)-.gamma.-methacryloxypropylsilane. A base copolymer was 
prepared that contained 30 parts of tris 
(trimethylsiloxy)-.gamma.-methacryloxypropylsilane and 70 parts of 
methylmethacrylate. Added to this were respectively 5, 15 and 30 parts of 
HFIS and methacrylic acid (MA). The results are shown in Table III below. 
TABLE IV** 
__________________________________________________________________________ 
NO 
HFIS COMONOMER 
MA 
5 15 30 0 5 15 
30 
__________________________________________________________________________ 
DK 8.8 8.2 8.9 9.3 7.7 6.0 
5.1 
CONTACT ANGLE 
52.degree. 
62.degree. 
55.degree. 
64.degree. 
36.degree. 
36.degree. 
-- 
TENSILE STRENGTH 
5,100 
6,000 
4,000 
6,100 
4,800 
-- 
3,000 
MODULUS 178,000 
192,000 
201,000 
209,000 
163,000 
-- 
178,000 
__________________________________________________________________________ 
**Units of tensile strength and modulus are psi; DK units 10.sup.11 
M10.sub.2 cm.sup.2 /sec ml MMHg at 35.degree. C. 
From these results it can be seen that the addition of up to 30% by weight 
of HFIS had no significant impact on the oxygen permeability of the 
siloxane copolymers. Methacrylic acid has the negative impact on oxygen 
permeability and causes haziness in concentrations above 15%. The trend of 
the data indicates that both methacrylic acid and HFIS will improve 
wettability but HFIS is a better comonomer than methacrylic acid in terms 
of oxygen permeability and mechanical properties. HFIS does act as a 
wetting monomer, on a more efficient basis than the conventionally used 
methacrylic acid and it does not adversely impact oxygen permeability as 
does methacrylic acid. 
When the HFIS is substituted with other hydroxyfluoroalkylstyrenes of the 
formula previously presented herein, substantially similar results are 
obtained in that excellent wettability is noted and no significant 
undesirable impact on oxygen permeability is noted. 
Example 17 
DK of Polymers Containing HFIS and Siloxanes 
The following polymer compositions were made up in the manner previously 
described containing HFIS and the siloxanes shown by Formula I. 
Compositions 1, 2, and 3 shown below in the Table were made in the manner 
previously described in earlier examples. The DK, contact angle, and Tg 
were measured as shown in Table 5 below. 
TABLE 5 
______________________________________ 
Comp. Comp. Comp. 
#1 #2 #3 
______________________________________ 
Penta Tris Styrene (Ex. 3) 
40 40 40 
Tris Urea (Ex. 6) 
28 18 12 
HFIS 30 40 40 
MA -- -- 6 
EGDMA 2 2 2 
DK 109.sup. 67 54 
CONTACT ANGLE .sup. 26.degree. 
.sup. 20.degree. 
.sup. 17.degree. 
Tg 100.degree..sup. 
113.degree..sup. 
-- 
______________________________________ 
All of the polymers that were prepared were brittle. Methacrylic acid was 
noted to significantly lower the contact angle, but adversely impacted 
oxygen permeability, and as well, had a significant negative impact on 
mechanical properties. As seen, the replacement of some of the siloxane, 
i.e. the penta tris styrene and the tris urea with some HFIS, 
significantly increased the Tg of the polymer. It can be concluded that 
the oxygen permability and the wettability of these polymers were 
exceptional. 
Example 18 
The following composition was prepared in accordance with the method 
described in Example 15. This composition represents the best current 
formulation known of compositions which contain both HFIS and a siloxane 
monomer. The composition was prepared in the manner previously described 
herein for the polymer compositions for making contact lenses. 
______________________________________ 
Composition 
% 
______________________________________ 
Penta Tris Styrene 
35 
Tris Urea 10 
HFIS 23 
MMA 30 
EGDMA 2 
______________________________________ 
The properties of this composition were measured and found as follows: 
______________________________________ 
DK 26 
Contact Angle 35.degree. 
Tensile Strength 2,100 
Elongation % 1.8 
Modulus 116,000 
Machineability Acceptable 
______________________________________ 
The composition shown in this examples was used to make a contact lens. The 
lens made represented the best available combination of oxygen 
permeability and mechanical properties of any lens so far formulated. The 
properties were in every instance equivalent to or at least better than 
the claimed properties for materials currently under clinical 
investigation as hard gas permeable extended wear contact lenses. 
It therefore can be seen that the invention accomplishes at least all of 
the stated objectives.