Note: Descriptions are shown in the official language in which they were submitted.
~S J UML)--1 b~ ~'
3~3
ALKYLSILANE CON~ACT LENS AND POLYMER
Field of the Invention
This invention relates to optical contact
lenses and materials therefor and, in particular, to
alkylsilane polymers and alkylsilane polyrner contact
lenses.
Back~round of the Invention
Many polymeric materials have been evaluated
for potential utility as contact lens material, but a
very limited number of materials have been found to form
contact lenses which are satisfactory. Advances in
contact lens materials and techniques have come in smal~
steps, which have been excruciatingly slow and
difficult. Polymers and methods which appeared
attractive have fallen by the wayside. The problems are
myriad and predictability is low. It is difficult and
frequently impossible to predict optical quality,
strength and flexibility, resistance to protein
build-up, machining and fabrication characteristics,
dimensional stability, oxygen permeability, and general
biological compatability. It ic impossible to predict,
or even to speculate as to possible optical, oxygen
permeability, and biological characteristics of
structural and industrial silanes such as disclosed by
Campbell, U.S. Patent No. 2,958,681 for example.
Reference is made to the ]iterature, in
texts, treatises and technical literature which describe
silicon compounds, commonly referred to as si]anes,
~583~3
particularly alkylsilanes. While the present invention
departs from this chemistry in important and substantial
ways, this body of chemi~try is fundamental to the present
invention.
Silane chemistry i6 qulte well known and reported
in the literature. ~n excellent treatment of the
chemistry of silanes is given by Sommers, L.H.; Mitcht F.A;
andGoldberg, G.M., "Synthesi~ and propertie~ of Compound~
with a Fra~ework of Alternate Silicon and Carbon Atoms,
J.A.C.S., 71, 2746, (1949). Surveys of this body of
chemistry are found in ~IRR-OT~ER~ ~CYCLOPEDIA O~
C~E~ICAL TEC~OLOGY, 3rd Ed. at Vol. 20, pp 887-911. The
chemistry of organosilicon compounds is described in
OR~ANOSILICON COMPO~NDS, Bazant~ Chvalovsky and
Rathovsky, Academic Press, Inc., New York, 1965.
The literature on contact lenses and contact
lenses and contact lenses containing silicone compounds is
massive, including hundreds ofpatents. Tbismassive body
of literature is not considered analogous to the present
invention except as to the general techniques for forming
optical con~act lenses, e.g. cutting and polishing.
Silanes have been utilized in preparative organic
chemistry and for a number of specialty applications,
including waterproofing compounds for morter and fabrics
and the like, as accellerators in some polymer operations,
and as intermediates in the preparation of
organosiloxanes.
While the chemistry, vis-a-vis reaction
conditions, of alkyl silanes is known and reasonably well
understood, it has not, to the inventor's knowledge, been
proposedtouse suchmaterials asthe principal constituent
polymer in contact lenses. In particular, the unique
characteristics of such contact lenses has not been
reported, insofar as is known to the inventor. Given the
uncertainty as to lens characteristic~ of given polymer
~2~33~3
systems, there was no reason to expec-t -that such
materials would be useful as ]ens polyrners.
Summary of the Invention
The present invention relates to a novel
class of contact lenses comprising polymers result:i.ng
from the polyrnerization or copoly-nerization alkyl
silanes, having the general structure:
Ib
R R -C-R R.
Ig a ~ c ll
X -C Si IC-X2
Rh Rd-C-Rf Rj
e
wherein Ra through Rj are hydrogen or alkyl, aryl,
aralkyl, or silyl moieties, which may inc].ude vinyl,
allyl, acrylyl, acrylic, methacrylic, ethacrylic, or
pyrrolidinonyl substituents and may also contain up to
about 35 weight percent siloxyl, and wherein ei.ther X1
or X2, or both Xl and X2 are vinyl polymerizable group
containing moieties. The term "vinyl polymerizable
group" is used here i.n a particular sense -to mean a
po].ymerizable group containing the carbon-carbon double
bond which is polymerized in the formation of polyvinyl
polymers, i.e. the following structures:
-C=C- and -C-C=C-;
exemplary of which vinyl polymerizable groups are:
vinyl, allyl, acrylyl, acrylyl, methacrylyl, or styryl.
Exemplary of the monomers sui-table for
forming the polymers and copolymers of -th:is invention
are the following:
CH2=CH- ~ ~ li-CH3;
CH3
~583~
CH3
CH2=CH ~ ~$i-(CH2)n~CH3
H3
wherein n is a positive integer from 1 to 5,
S preferrably 1 to 3;
~CH~
CH2=CH- -Si- -CnH]2n~1)
~CH3, n
CH CH ~i3
1H3
CH2=CH-bi-
CH2=CH-31-(CH2)n~ ~
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
CH3 10 CH3
CH3 $i~ ( CH2)n~~~=CH2
CH3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
CIH3 CH3 1l ICH3
CH3-Si-( CH 2)n~~i-(CH2)n-0-C-C=CH2,
~H3 CH3
5
~'~5~33~3
wherein n i8 a positive inteyer from 1 to 5,
preferrably 1 to 3;
IH3
CH2
CH3~iCH3
~H3 CH2 ol ~H3
CH3OCH2~iCH2~i(CH2)n-O-C-C=CH3;
CH3 ~H2
CH3$iCH3
CH2
CH3
CH2 C~ CH3 CH3 l~ ~CH3
¦ / N-(CH2)n-~i-CH2~ CH2-O-C-~=CH2,
CH2~ C=O CH3 CH3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
Rl CH3
R2-~i-(CH2)n-O-c-c=cH2/
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3 and Rl, R2 and R3 are selected from
the group consisting of methyl,
CH3 CH3 CH=CH2
phenyl, CH3bi-, CH3~iCH2 ~ CH3$iCH2-,
CH3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
~8343
C~13
CH3$iCH3 ~ CH3
CH -O-C-C=CH2;
CH3~iCH3
CH3
CH3
CH3~iCH3
CH3~i CH ~Si-(CH2)n-O-~-C-CH2,
CH3 ¦ CH3
CH3SiCH3
CH3
wherein n is a positive integer from 1 to 5,
15preferrably 1 to 3;
CH3
&H2 ~ ~H3 O CH3
20CH3SiCH3 CH-O-C-C=CH2;
CH2- ~ H3
CH3
R~
25\Si - ~H2
CH2 C ~ i-(CH2)]n ~ C=CH2
\ /CH3
Si-----CH2
Rs
wherein nis a positive integerfrom 1 to 5, preferably
1 to 3, and R4 and Rs are selected from the group
consisting of methyl,
~Z~3~3
CH3 ~H3 CH=CH2
phenyl, CH3~i-, CH3SiCH2-~ CH3biCH2-t
H3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
R~
~H~ - Si ~ H2
/ CH3 \~ 1l IH3
CH3~iCH3 CH3SitCH2)n-O-c-c=cH2
\ CH3
CH2 i i--CH2
R7
wherein n isa positive integerfrom 1 to 5, preferably
1 to 3, and R6 and R7 are selected from the group
consisting of methyl,
ICH3 CIH3 1CH=CH2
phenyl, CH3Si-, CH3~SiCH2-~ CH3SIicH2-~
CH3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
R8 Rg
CH~ CH2 S\CH3 I CH3
CH ~H-O-~-C-CH2
CH3Si ~CH2- ~CH3
Rlo ~11
wherein n isa positive integer from lto 5, preferably
1 to 3, and R8 - Rll are selected from the group
consisting of methyl,
CIH3 CIH3 CIH=CH2
phenyl, CH3Si-, CH3SiCH2-~ CH3S
CH3 ~H3 CH3
alkylmethoxy, phenylmethy~, and N-alkyl-pyrrol-
idinonyl and
~Z~33~3
Rl2
CH3 -,~; iH----CH 2
H ~ - CH2 -~ iCH2-O-C-~=CH3
CH3-~i - CH2
13
wherein nisa positive integerfrom 1 to 5, preferably
1 to 3, and R12 and R13 are selected from the group
consisting of methyl,
CH3 ICH3 CH=CH2
phenyl, CH3bi-, CH3SiCH2-~ CH3~iCH2
CH3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkylpyrrol-
idinonyl.
Silanes with two polymerizable groups and polymers
thereof and lenses of such polymers are also contemplated
within the scope of the invention. Exemplary of such
monomers are:
H3~ 14 ~1 CIH3
CH2=C C-O-CH2-(Si-CH2) n-0-C-C-CH3
~15
wherein n is a positive integerfrom 1 to 5, preferably
1 to 3, and R14 and Rls are selected from the group
consisting of methyl,
CIH3 CH3 CH=CH2
phenyl, CH3Si-, CH3~iCH2-~ CH3~iCH2
~H3 C~3 ~H3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
513~3~3
H31C 1l lRl6 ~lfl 1l ¦Cll3
CH2=C-C-O-CH2-Si-(CH2)nSi-CH2-0-C-C=C~13
R17 Rlg
wherein n is a posltive integer from 1 to 5, preferably
1 to 3, and R16 to R19 are selected from the group
consis-ting of me-thyl,
ICH3 CIH3 CH=CH2
phenyl, CH3Si-, CH3SiCH2-, CH3SiCH2-,
CH3 C~13 CH3
alkylmethoxy, phenylmethyl, and N-alkylpyrrol-idinonyl.
A monomer which is predominantly silane is:
H3C1 11 R120 R122 11 CIH3
H2C=C-C-O-(CH2)n-Si -O- Si-(CH2)n-0-C-C=CH2
R21 R23
wherein n is a positive integer from 1 -to 5, preferably
2.0 1 to 3, and R20 to R23 are se]ec-ted from the group
consisting of
1 3 CIH3 CH=CH2
C113Si-,CH31iCH2-, ancl C~13SiCH2-
CH3 CH3 CH3
Other monomers which include two
polymerizable yroups include:
2 ~ CH3 ~ -Cl-l=C~12;
CH2=CH-~ _51 - ( CH2 ) -C~l=CH2 '
:~Z5~3~
wherein n is a positive integer from 1 to 5, preferably
1 to 3,;
S CH2=CH-li- ~-Si-CH=CH2;
CH3 CH3
CH 2=CH--5 i--e3--I i -CH=CH 2;
EE H
Cl H3 ,~ Cl H3
CH2=CH~~i~(CH2)n~~ (CH2) nCH-CH2
CH3 \=/ CH3
wherein n is a positive integer from 1 to 5, preferably
1 to 3,,
CIH3
ICH2
CH3SiCH3
H3CI ~ ~H3 CH2 R CH3
CH2=C- ~o-cH2ticH2$i(cH2)n~o-c- =CH2; and
CH3 CH2
CH3~iCH3
kH2
CH3
1~24
H3~ O CH3~iCH3 IOI CIH3
CH2=C-~ ~H -- O-C- =CH2,
CH3~iCH3
R2s
4~
wherein R24 and R2s are selected from the group
consisting of methyl,
~H3 CH3 CH=CH2
phenyl, CH3~i-, CH3~iCH2-~ CH3~iCH2
~H3 ~H3 CH3
alkylmethoxy, phenylmethyl, and N-alkylpyrrol-
idinonyl.
In general, vinyl, allyl, acrylallyl, acrylic,
methacrylic or ethacrylic derivatives of ~he compounds
referred to which include one or more polymerizable groups
such as vinyl, allyl, acrylic, methacrylic or ethacrylic
may be considered equivalent to the specific, exemplary
monomers, and polymers and copolymers of the same may be
used as contact lens materials and lenses.
lS The alkylsilane polymer lenses of this invention have
been discovered to have extremely beneficial, and most
unexpectedand unpredictable properties as contactlenses.
For example, the most comparable lenses, of siloxyl based
polymers, have an oxygen permeability, Dk value (see, e.g.
Fatt, I. and St. Helen, R., QX~ ~n~iQn ~n~ ~n
O~yq~n~s~m~bli 5Qn~ L~ns, American Journal of
Optrometry, July 1971, pp.545-555, for a discussion of Dk
values) in the 20'sv the highest being about 30 to32. The
alkylsilane polymer lenses of this invention have a
calculated Dk value of as high as 40 or morel The exremely
high Dk value, as shown by wearer comfort, has been
demonstrated for the contact lenses of this invention. In
addition, these alkylsilane polymer lenses have an even
greater resistance to protein contamination than the
silicone polymer lenses. These alkylsilane polymer
lenses are also harder and, very surprisingly, can be made
wettable by inclusion of appropriate hydrophylic
substituents much easier than comparable silicone polymer
contact lensesl These very surprising advantages,
coupled with good optical quality could not have been
33~
predicted, or even guessed at in advance. These lens
polymers can be formulated with a relatively high phenyl
substituent content, giving lenses having a high index of
refraction which can be made thinner and lighter than
conventional contact lenses, and more easily fabricated
into bifocal lenses than is possible with conventional and
know lens polymers. Surface characteristics can be
modified by inclusion of specific moieties in the polymer;
for example, methoxy alkyl, ethoxy alkylr or n-
alkylpyrrolidinonemay be included to improvewettability.Monomers having two polymerizable groups may be used, thus
resulting in a fully crosslinked lens polymer. It is even
possible to prepare highly hydrated lenses from the
polymers of this inventionl
De~cri~iQn Qf ~h~ Preferred EmkLLim~n~
Nonew silanechemistry, per se, is involved in the
present invention; rather, it has been discovered that
alkylsilane polymer contact lenses have most ~nexpected
and unpredicted advantages over other lenses and, more
particularly, over the most comparable lenses, those
formed of silicone polymers.
The alkylsilanes used in forming the polymers from
which the lenses of the present invention are manufactured
are most conveniently prepared by the action of a
polymerizable vinyl group containing moietyt e.g.
methacrylic acid, on a chloroalkyl or bromoalkyl
substituted silane, such as chloromethyl trimethylsilane
or di-chloromethyl dimethylsilane, in the presence of a
base such as pyridine or triethyl amine. The higher
homologues of the series are conveniently prepared by the
action of the Grignard Reagent of a silane, such as
trimethylsilylmethyl magnesium chloride on a chlorosilyl-
alkyl methacrylate, e.g. trichlorosilyl propyl
methacrylate, to give tris(trimethylsilylmethyl) silyl-
propyl methacrylate.
~25~ 3
13
~ample A
Trimethylsilyl Methyl ~ethacrylate
Trimethylsilylmethyl methacrylate was prepared as
follows: Methacrylic acid (29.6 g) was dissolved in dry
ether t600 ml), sodium carbonate (18~6 g) was added slowly
to form the sodium salt. Chloromethyl trimethyl silane
(42.2 g) was added to the gelatenous solid formed from the
preceeding salt forming reaction, followed by the addition
of hydroquinone (1.00 g). The mixture was refluxed for 72
hours, washed with water, dryed over magnesium sulfate,
filtered and distilled giving a 21.7 g of product which
boiled at 29.5C. at 0.3 mm Hg, 37~ of theoretical yield.
The product was washed with basic carbonate solution until
the wash was free of color and then washed with distilled
water to remove any hydroquinone which may have been
carried over during distillation, and dried over magnesium
sulfate and stored under refrigeration.
E~ample B
Phenyldimethylsilyl ~ethyl ~ethacrylate
Phenyldimethylsilyl Methyl Methacrylate wasprepared
by reacting phenyl dimethyul chloromethyl silan~ (161 g)
with methacrylic acid (132 g) and triethylamine (132 g) in
benzene (300 ml), with hydroquinone (1.0 g) added to
inhibit polymerization during the reaction. The mixture
was refluxed for 64 hours. The resulting product was
washed, dried and distilled, and the boiling point of the
product was found to be 86C. at 0.1 mm Hg. The yield,
105.2g, was51.5~ of theoretical. The product was further
washed and stored as in example I.
These procedures are, of course, well known
reactions. Similar reactions and techniques are suitable
for the preparation of the monomers of interest.
Len~ ~anufacture
The following general technique was followed in the
~Z58343
14
preparation of lens blanks and lenses:
Monomers in the specified ratio and initiator werethoroughly mixed and dry~d over magnesium sulfate and
filtered. The dryed, filtered monomer mixture was placed
in molds under nitrogen atmosphere and cured be slowly
raising the temperature to about 100C. for about 2 hours
followed by a reduction to a post-cure temperature of about
80C. forapost cure of about 15 hours. The resulting lens
blank was examined and is then machined to form contact
lenses according to conventional procedures for the
manufacture of contact lenses.
The following examples of lenses formed by the
technique described exemplify the invention.
~en~ Material No. 1
Trimethylsilyl methyl methacrylate 45~*
Methyl methacrylate 41~
N-vinyl pyrrolidinone 3%
Methacrylic acid 6%
Ethylene glycol dimethacrylate5%
Initiator** (Trace)
* Percentages in all examples by weight.
** 2,2'azobis-2,4-dimethyl-4-methoxy-
valeronitrile 0.001-0.5~ in all Lens examples
Initial Cure Temperature 102C.
Initial Cure Time 2 hours.
Post Cure Temperature 82-85C.
Post Cure Time 16 hours.
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ ~aterial No. 2
Trimethylsil~l methyl methacrylate 30%*
~Z51~343
Methyl methacrylate 56%
N-vinyl pyrrolidinone 3~
Methacrylic acid 5%
Ethylene glycol dimethacrylate 6%
Initiator** (Trace)
Initial Cure Temperature 76C.
Initial Cure Time 3/4 hours
Post Cure Temperature 52-58C.
Post Cure Time 18 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Lens ~aterial No. 3
Trimethylsilyl methyl methacrylate 60
Methyl methacrylate 26%
N-vinyl pyrrolidinone 3%
Methacrylic acid 5
Ethylene glycol dimethacrylate 6%
Initiator** (Trace)
Initial Cure Temperature 69C.
Initial Cure Time 3/4 hours
Post Cure Temperature 52-58C.
Post Cure Time 18 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ ~aterial No. 4
Trimethylsilyl methyl methacrylate 45
Methyl methacrylate 41~
~f~ S~ 3 ~ 3
N-vinyl pyrrolidinone 3%
Methacrylic acid 6
Ethylene glycol dimethacrylate 5
Initiator** (Trace)
Initial Cure Temperature 102C.
Initial Cure Time 2 hours
Post Cure Temperature 82-85C.
Post Cure Time 16 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ ~aterial No, 5
Trimethylsilyl methyl methacrylate 30
Methyl methacrylate 56
N-vinyl pyrrolidinone 3
Methacrylic acid 5
Ethylene glycol dimethacrylate 6
Initiator** (Trace)
Initial Cure Temperature 76C.
Initial Cure Time 3/4 hours
Post Cure Temperature 52-58C.
Post Cure Time 18 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ ~aterial ~o. 6
Trimethylsilyl methyl methacrylate 60
Methyl methacrylat~ 26%
N-vinyl pyrrolidinone 3%
8~9~3
Methacryli~ acid 5%
Ethylene glycol dimethacrylate 6
Initiator** (Trace)
Initial Cure Temperature69C.
Initial Cure Time 3/4 hours
Post Cure Temperature 52-58C.
Post Cure Time 18 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ ~aterial ~o. 7
Trimethylsilyl methyl methacrylate 86
N-vinyl pyrrolidinone 3~
Methacrylic acid 5%
Ethylene glycol dimethacrylate 5%
Initiator** (Trace)
Initial Cure Temperature57C.
Initial Cure Time 3/4 hours
Post Cure Temperature 57C.
Post Cure Time 21 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExceptional
Lens ~aterial No~ 8
Trimethylsilyl methyl methacrylate 40
Methyl methacrylate 31~
N-vinyl pyrrolidinone 3%
1,3,Bis(methyacryloxy propyl~l,l';3,3'-
tetrakis(trimethylsiloxy)disiloxane 20%
~'~5~33~3
18
Methacrylic acid 6%
Initiator** (Trace)
Initial Cure Temperature 80C.
Initial Cure Time 3/4 hours.
Post Cure Temperature 55-58C.
Post Cure Time 21 hours.
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ Material No. 9
Trimethylsilyl methyl methacrylate 25%*
Methyl methacrylate 47%
N-vinyl pyrrolidinone 3%
Trimethoxysilyl propyl methacrylate 25~
Initiator** Trace
Initial Cure Temperature 58C.
~ Initial Cure Time1 1/4 hours.
Post Cure Temperature 58C.
Post Cure Time 20 hours~
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Lens ~aterial No. 10
Phenylmethylsilyl methylmethacrylate 50%*
Methyl methacrylate 36~
N-vinyl pyrrolidinone 3%
Methacrylic acid 6%
~thylene glycol dimethacrylate 5%
Initiator** Trace
343
lg
Initial Cure Temperature 58C.
Initial Cure Time 1 1/4 hours
Post Cure Temperature 58C.
Post Cure Time 20 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Goocl
Dimensional stabilityExcellent
This lens material has an exceptionally high refractive
index, making it ideally suited to the manufacture of
bifocal and thin lenses.
Phenyldimethylsilyl methylmethacrylate 60
Methyl methacrylate 26%
N-vinyl pyrrolidinone 3%
Methacrylic acid 6
Ethylene glycol dimethacrylate 5~
Initiator** Trace
Initial cure temperature 104
Initial cure time 2 hours
Post Cure Temperature 83-85C.
Post Cure Time 16 hours
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stability Excellent
30 This lens material has an exceptionally high refractive
index, making it ideally suited to the manufacture of
bifocal and thin lenses.
Len~ ~aterial ~o. 12
Phenylmethylsilyl methylmethacrylate 86%*
N-vinyl pyrrolidinone 3
~2~133~3
Methacrylic acid 6%
Ethylene glycol dimethacrylate 5%
Initiator** Trace
Initial Cure Temperature 104C.
Initial Cure Time 2 hours.
Post Cure Temperature 84-86C.
Post Cure Time 18 hours.
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
This lens material has an exceptionally high refractive
15 index, making it ideally suited to the manufacture of
bifocal and thin lenses.
Len~ ~aterial ~o. 13
Trimethoxylsilyl propylmethacrylate 45%*
Methyl methacrylate 41%
N-vinyl pyrrolidinone 3%
Methacrylic acid 5%
Ethylene glycol dimethacrylate 5%
Initiator** Trace
Initial Cure Temperature 102C.
Initial Cure Time 2 hours.
Post Cure Temperature 82-85C.
Post Cure Time 16 hours.
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
Len~ Material ~o~ 14
Trimethylsilyl methyl methacrylate 45%*
~5~33~3
21
Hydroxyethyl methacrylate 10%
N-vinyl pyrrolidinone 50%
Methacrylic acid 4%
Ethylene glycol dimethacrylate1%
Initiator** Trace
Initial Cure Temperature 57C.
Initial Cure Time 2 hours.
Post Cure Temperature 57C.
Post Cure Time 20 hours.
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
On hydrating in 0.9% saline solution, this lens material
reached an equilibrium hydration level of 42.7, providing
a clear, rigid hydrating lens material.
Len~ Material ~o~ 15
Phenyldimethylsilyl methylmethacrylate 20%*
Hydroxyethyl methacrylate 74
Methacrylic acid 5~
Triethylene glycol dimethacrylate 5%
Initiator** Trace
Initial Cure Temperature 102C.
Initial Cure Time 2 hours.
Post Cure Temperature 84-86C.
Post Cure Time 18 hours.
Lens Qualitie~:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
35 This lens material has an exceptionally high refractive
83~3
index, making it ideally suited to the manufacture of
bifocal and thin lenses, and, additionally, reached an
equalibrium of 18.5% hydration in 0.9% saline, thus
providing a clear, rigid hydrating lens material.
S Len~ ~aterial ~o. 16
Phenyltetramethyldisilylmethylene-
methylmethacrylate 50%*
Methyl methacrylate 38.5%
Methacrylic acid 6%
Ethylene glycol dimethacrylate 5~
N-vinylpyrrolidinone 3%
Initiator** Trace
Initial Cure Temperature 100C.
Initial Cure Time 2 hoursO
Post ~ure Temperature 82-83C.
Post Cure Time 17 hours.
Lens Qualities:
Clarity Excellent
Hardness Good
Machinability Good
Wettability Good
Dimensional stabilityExcellent
This lens material has an exceptionally high refractive
index, making it ideally suited to the manufacture of
bifocal and thin lenses.
Di~cu~sion and ~quivalents
These lens materials had excellent optical
properties and ~ome had outstanding refractive index
characteristics. All were ideal for the manufacture of
high quality excèptionally comfortable lenses. Some had
moderate to high hydration capacity, in addition to being
excellent, clear comfortable lens characteristics.
Oneof the important discoveries of this invention
is that these len~ materials are far more comfortable for
thewearerthanthe most nearly comparable lense~ formed of
~58~43
siloxanyl polymers, the silicone polymers of the prior art
and o~ my earlier filed copending patent applications.
Wearer comfort is somewhat subjective but reflects real
differences. Two objective observations are believed to
explain the unexpectedly high comfort factor of the lenses
of this invention. First, oxygen permeability is very
high, thuscontributing to healthier eyetiss~e andgreater
comfort. Second, these lens materials are exceptionally
resistant to the buildup of proteins on the lens surfaces.
A third, highly unexpected, factor believed to
contribute to wearer com~ort is the wettability ofthelens
materials of this invention. Silanes have typically been
used in ~aterproofing applications and one would predict a
highly hydrophobic lens material. Quite surprisingly,
however, thelenses ofthis invention arequite hydrophylic
and, indeed, in some formulations, hydrate to a moderate to
high level.
Another surprising characteristic of lens
materialsofthepresent invention isthat it ispossibleto
form excellent lens materials with excellent optical,
refractive, mechanical and comfort properties ~ithout the
presence of methyl methacrylate, or with only very minor
amounts of methyl methacrylate
It will be readily understood by those skilled in
the art that the foregoing lens material formulations are
only exemplary ~ avast numberoElensmaterials ancllenses
which can be manufactured within the scope of this
invention. Many analogous and homologous monomers ofthe
silane family may be substitued for those shown in the
examples. Initiators may be selected from among the many
which are suitable for intiating the polymerization of
vinyl group containing monomers.
In general, the alkyl silanes of this invention
comprise greater than 5~ and preferrably greater than 20%
of the polymeric lenses and lens materials and my comprise
83~L~
2~
up to about 95%, preferrably up to about 90~, of such
materials and lenses. In the preferred embodiment, the
lens material is formed from the polymerization of alkyl
silaneswith a cross-linking monomer and a monomer, s~ch as
n-vinylpyrrolidinone or hydroxyethyl methacrylate~ or
both, which contributes to the wettability or hydration of
the lensl or to both wettability and hydration of lenses.
Thishydrophylic constituent may compriser preferrably, at
least 2 to 3% and may comprise up to about 75~ or more of the
polymeric lens material.
Exemplary percentages of ~elected formulations
are shown in the following tables:
I
Trimethylsilyl methyl methacrylate 5 to 95 weight %
Methyl methacrylate1 to 50 wieght %
N-vinyl pyrrolidinone1 to 50 wieght %
Methacrylic acid1 to 10 weight ~
Ethylene glycol dimethacrylate1 to 10 weight %
II
Trimethylsilyl methyl methacrylate 20 to 90 weight ~
Methyl methacrylate20 to 60 weight %
N-vinyl pyrrolidinone1 to 10 weight %
III
Trimethylsilyl methyl methacrylate 20 to 90 ~eight ~
N-vinyl pyrrolidinone3 to 60 weight %
Methacrylic acid1 to 10 weight %
IV
Trimethylsilyl methyl methacrylate 20 to 95 weight
N-vinyl pyrrolidinone5 to 80 weight
V
Trimethylsilyl mekhyl methacrylate 25 to 95 weight %
Hydroxyethyl methacrylate5 to 75 weitht
VI
Trimethylsilyl methyl methacrylate 5 to 95 weight %
Methyl methacrylate5 to 90 weight %
~Z5~33~3
1,3,Bistmethyacryloxy propyl~l,l';3,3'-
tetrakis(trimethylsiloxy)disiloxane 5 to 35 ~eight
VII
Phenylmethylsilyl methylmethacrylate 5 to 95 weight %
Methyl methacrylate 5 to 50 weight %
VIII
Phenylmethylsilyl methylmethacrylate 5 to 95 weight %
Methacrylic acid 5 to 50 weight %
IX
Trimetho~ylsilyl propylmethacrylate 5 to 95 weight ~
Methyl methacrylate 5 to 60 weight %
X
Trimethyoxysylyl propylmethacrylate 5 to 95 weight~
Hydroxyethyl methacrylate 5 to 50 weight~
XI
Phenyldimethylsilyl methylmethacrylate 10 to 95 weight %
Hydroxyethyl methylmethacrylate 5 to 90 weight %
XI~
Phenyltetramethyldisilylmethylene-
20methylmethacrylate 5 to 95weight ~
Methacrylic acid 5 to 60weight %
Typically, in the preferred embodiments, a
hydrophylicmonome~would also comprise the polymerization
mix.
25It has also been found advantageous to include
methacrylic acidand/ormethyl methacrylate asa monomer in
the formation of the polymerized lense material; however~
one ofthe surprising discoveries of this invention is that
high ~uality lenses can be formed without either of these
30constituents.
Polymeric materials resulting from the
polymerization or copolymerization alkyl silanes, having
the following general structures and lenses formed
therefrom are within the contemplation and concept of this
35invention:
~5i33~3
26
Ib
R R -C-R R.
Ig a I c
X -C --S i----C - X
Rh Rd-C-Rf R
Re
wherein Ra through R; are hydrogen or alkyl, aryl,
aralkyl, or silyl moi.eties, which may inc].ude vinyl,
allyl, acrylyl, acrylic, methacryli.c, ethacrylic, or
pyrrolidinonyl substituents and may also contain up to
about 35 weight percent siloxyl, and wherein either X]
or X2, or both Xl and X2 are vinyl polymeri.zable group
containing moie-ties. The term "vinyl polymerizable
group" is used here in a particular sense to mean a
1~; polymerizable group conta:ining the carborl-carborl doub]e
bond which is polymerized in the formation of polyvinyl
polymers, i.e. the following structures:
-C=C- and -C-C=C-;
exemplary o.f which vinyl polyrnerizable groups are:
vinyl, allyl, acrylyl, acrylyl, me-thacrylyl, or styryl.
Exemplary of the monomers suitable for
forming the polymers and copolymers of this invention
are the following:
.
CM~=CH- ~ -Si-CH3;
CH2=CH- ~ -Si-(CH2)n~CH3
CH3
wherein n is a positive integer from I to 5, preferably
1 to 3;
:~25~3~3
r CH3~
CH2=CH- -Si- -CnH]2n~1)
CH3 n
CH2-C~i-~i-~3 ;
CH3
CH2=CH~
CH2=CH~Si~(CH2)n~
CH3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
CH3 I Cl H3
CH3_~i_(CH2) n_O_C_C=CH2
1H3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
2 5 CIH3 CH3 ~ CIH3
CH3-li-(CH2)n-Si-(CH2)n-0-C-C=CH2,
CH3 C~3
wherein n i~ a positive integer from 1 to 5,
preferrably 1 to 3;
~ZS~39L~
28
oH3
ll H 2
CH35iCH3
CH3 CH2 1l CIH3
CH30CH2SiCH2~i(CH2)n-0-C-C=CH3;
CH3 ~H2
CH3~iCH3
CH2
CH3
CH2 - C ~ CH3 CH3 'CH3
~ H2)n~li-cH2 -bi~cH2-o-c-c=cH
CH2 C= CH3 CH3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
R2-Xi-(cH2)n-o-c-c-cH2
R3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3 and Rl~ R2 and R3 are selected from
the group consisting of methyl,
~H3 C,H3 ~H-CH2
phenyl, CH3Si-, CH3~iCH2-~ CH3SiCH2-~
CH3 1H3 ~H3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
IH3
CH3SiCH3 R C, H3
CH O-C-C-CH2;
CH3SiCH3
CH3
3~
29
ICH3
CH3SiCH3
CH3 ¦ CH3 1l CIH3
CH3Si -CH -Si-(CH2)n-0-C~C=CH2,
5CH3 ¦ CH3
CH3SiCH3
CH3
wherein n is a positive integer from 1 to 5,
preferrably 1 to 3;
CH3
5H~ -S~ H3 0 CH3
CH3S\iCH3 ~ H-O-C-C=CH2;
CH2 -SlCH3
CH3
R~
CH2)Jn~O~c~c=cH2
H3
~Si--CH2
R5
25wherein n is a positive integerfrom l to 5, preferably
1 to 3, and R~ and Rs are ~elected from the group
consisti.nc~ of methyl,
CIH3 ~H3 CH-CH2
phenyl, CH3Si-, CH3SiCH2-~ CH3$iCH2
CH3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
33~
~6
CH 2 ~ H 2
CH3 \ R 7H3
CH3SiCH3CH3Si(CH2)n-O-c-c=cH2
5 \ CH3
CH 2 ~ CH 2
wherein n is a positive integer frc>m 1 to 5, preferably
to 3, and R6 and R7 are selected from the group
consisting of methyl,
CIH3 ClH3 CH=CH2
phenyl, CH37i ~ CH3SiCH2-~ CH3~!,iCH2-'
CH3 H3 H3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
R~ 8 1~9
CH~,Si~~-CH2----~\CH3 j~ ~H3
~H ,CH-O--C-C=CH2
CH~Si---CH2-~-SiCH3
~ 10 ~11
wherein n is a positive integer from 1 to 5, preferably
to 3, and R~ - Rll are selected from the group
consisting of methyl,
~H3 CH3 CH=CH2
phenyl, ClH3Si-, CH31iCH2-~ CH3SiCH2
~H3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl and
~ 'h~83~3
Rl2
CH3~ C,H2
/ CH3 \ 1l C~H3
HC - Si CH2 - ~iCH2`o-C-C-CH3
\ CH3
CH3~ CH2
R13
wherein n is a positive integer from l to 5, preferably
l to 3, and Rl2 and Rl3 are selected from the group
consisting of methyl,
C~H3 ~CH3 CH=CH2
phenyl, CH3Si-, CH3SiCH2-, CH3~iCH2-~
CH3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkylpyrrol-
idinonyl
Silanes with two polymerizable groups and polymers
thereof and lenses of such polymers are also contemplated
within the scope of the invention. Exemplary of such
monomers are:
H3C~ 1l lR14 g CIH3
CH2= -C-O-CH2- ( ~ i-CH2) n-0-C-C=CH3
~ 15
wherein n is a positive integer from 1 to 5, preferably
l to 3, and Rl4 and Rls are selected from the group
consisting of methyl,
CH3 CH3 CH=CH2
phenyl, CH3Si-, CH3SiCH2-~ CH3SiCH2-~
C~3 CH3 CH3
alkylmethoxy, phenylmethyl, and N-alkyl-pyrrol-
idinonyl
H3~ R ~16 Rl8 1~ ~CH3
CH2=(~:-C-O-CH2-~ i- ( CH2) nli-CH2-0-C-C=CH3
R17 ~l9
,83~3
wherein n is a positive integer :from I to 5, preferab~y
1 to 3, and R16 to Rlg are selected from the group
consisting of methyl,
CH3 CIH3 CH--CH
phenyl, C CH3SiCH2-, CH3SiCH2-,
H3 CH3 CH3
alkylmethoxy, pheny]methyl, and N--alkylpyrrol-idinonyl.
A monomor which is predominantly silane is:
H3C1 11 Rl2o R122 11 C1~13
H2C=C-C-O-(CH2)n-Si -O- Si-(CH2) -0-C-C=CH2
R21 R23
wherein n is a positive integer from 1 to 5, preferab~y
1 to 3, and R20 to R23 are se]ected from the group
consisting of:
CIH3 CIH3 CH=CH2
CH3Si-, CH3SiCH2-, and CH3SiCH2-
CH3 CH3 CH3
Other monomers which include two
polymerizable groups include:
CH2=CH- ~ 5~ ~ -Cl-l=CH2;
CH2=CH~ Si-(CH2)n-CH=CH2
c~,3
wherein n is a positive in-teger from 1 to 5, preferably
1 to 3;
~5~3~3
CH2=CH-,3 - ~ _5i_CH=CM2;
CH2=CH-si- ~ ff~3
CH2=CH~Si~(CH2)n~ ~ ~~i-(CH2)nCH=CH2
~ H3 H3
wherein n is a positive integer from 1 to 5, preferably
1 to 3,;
CH3
CH2
CH3~i~H3
H3~ ~ CH3 CH2 R CH3
CH2=~-C-o-cH2sicH2$i(cH2)n-o-c-c=cH2; and
CH3 ~fl2
CH3SiCH3
~H2
0
CH3
~2~
H3~, R CH3~1CH3 R CH3
30 CH2=C-C - CH -O-~-~=CH2,
Cf]3,3iCH3
wherein R24 and R2s are selected from the group
consisting of methyl,
~251~3~3
34
~H3 IH3 ~-CH2
phenyl, CH3~i-,CH31iCH2-~ CH3~iCH2-'
H3 C~3 ~H3
alkylmethoxy, phenylmethyl, and N-alkylpyrrol-
idinonyl.
In general, vinyl, allyl, acrylallyl, acrylic~
methacrylic or ethacrylic derivatives of the compounds
referred to which include one or more polymerizable groups
such as vinyl, allyl, acrylic, methacrylic or ethacrylic
may be considered equivalen~ to the specific, exemplary
monomers, and polymers and copolymers of the same may be
used as contact lens materials and lenses7
Indu~trial Application
This invention is useful in the optical industry
lS and, particularly, in the manufacture of optical contact
lenses for the correction of certain human visual defects
