US4182723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ocular membrane and method for preparation thereof
Assignee: PBH Inc
•
Filing: 1977-11-04
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Granted: 1980-01-08
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Expires: 1997-11-04
Abstract
Abstract A composition which is hydrophobic but possesses excellent wettability comprising a copolymer of a polysiloxane and an ester of glycidyl alcohol and an organic acid. This copolymer is suitable for the manufacture of ocular membranes worn in contact with the eye which present excellent oxygen permeability and which can be worn for extremely long periods of time and then disposed of. A method of preparing the ocular membranes is disclosed, in which the composition is placed between disposable molds and cured therein. The cured, mechanically and optically finished ocular membranes are recovered by the destruction of said molds and without secondary operations. The ocular membrane is a flexible, oxygen-permeable, membrane, adapted to be inserted on the eye and worn thereon continuously for periods of more than one month.
Inventors
- 👤 William S. Covington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:41
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/04; C08K5/09; C08K5/092; B; B29; B29C; B29C33/00; B29C33/44; B29C33/52; B29D; B29D11/00; B29D11/00009; B29D11/00038; B29D11/00067; C08F; C08F283/00; C08F283/12; C08G; C08G77/00; C08G77/04; C08G77/38; C08K5/10; C08K5/101; C08K5/103; B29K; B29K2995/00; B29K2995/0037; B29K2995/0065; B29K2995/0093
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
90 words
A composition comprising a copolymer of a polysiloxane cross-linked by addition polymerization and a compound selected from the group consisting of: (a) esters of glycidyl alcohol with acrylic acid or methacrylic acid; and (b) maleic anhydride, nadic anhydride or hexahydrophthalic anhydride; the amount of each such compound in said copolymer being effective to impart wettability to the surface of articles formed from said copolymer but less than that which would destroy the hydrophobic properties of said copolymer, and said composition having sufficient light transmission for use as an ocular membrane.
Claim 2
Dependent Claim
90 words
A composition comprising a copolymer of a polysiloxane cross-linked by addition polymerization and a compound selected from the group consisting of: (a) esters of glycidyl alcohol with acrylic acid or methacrylic acid; and (b) maleic anhydride, nadic anhydride or hexahydrophthalic anhydride; the amount of each such compound in said copolymer being effective to impart wettability to the surface of articles formed from said copolymer but less than that which would destroy the hydrophobic properties of said copolymer, and said composition having sufficient light transmission for use as an ocular membrane.
Claim 3
Dependent Claim
10 words
The composition of claim 1, wherein the polysiloxane is dimethylpolysiloxane.
Claim 4
Dependent Claim
17 words
The composition of claim 1, having a refractive index in the range from about 1.390 to 1.500.
Claim 5
Dependent Claim
31 words
The composition of claim 1 wherein the amount of said compound is in the range from about 0.3 to 3 parts by weight based on the total weight of the copolymer.
Claim 6
Dependent Claim
11 words
The composition of claim 1 which further comprises a coloring agent.
Claim 7
Dependent Claim
90 words
The composition of claim 1 having the following properties: ______________________________________
ASTM
PROPERTY TEST METHOD RANGE
______________________________________
Hardness, Shore A
Durometer D7.85 about 15-95
Specific Gravity
D1505 about 0.95-1.04
Tensile Strength
PSI D882 about 100 psi-1,000 psi
Elongation %
D882 about 120-250
Tearing Strength
lb. D1004 about 10-30
Water Absorption %
D570 about 0-3
Permeability to gas
(Std cc) (cm thickness)
(seconds) (s of cm area) (cm Hg pressure drop)
O.sub.2 permeability
D1434 about (29-65) × 10.sup.-9
CO.sub.2 Permeability
D1434 about 180-315) × 10.sup.-9
Index of
Refraction D542 about 1.390-1.50
______________________________________
Claim 8
Dependent Claim
24 words
The composition of claim 1 which further comprises a reinforcing filler in an amount of from 1 to 50% by weight of the polysiloxane.
Claim 9
Dependent Claim
23 words
The composition of claim 1 which further comprises a reinforcing filler in an amount of from 2% to 9% by weight of polysiloxane.
Claim 10
Dependent Claim
95 words
An ocular membrane formed from a composition comprising a copolymer of a polysiloxane cross-linked by addition polymerization and a compound selected from the group consisting of: (a) esters of glycidyl alcohol with acrylic acid or methacrylic acid; and (b) maleic anhydride, nadic anhydride or hexahydrophthalic anhydride; the amount of each such compound in said copolymer being effective to impart wettability to the surface of articles formed from said copolymer but less tha that which would destroy the hydrophobic properties of said copolymer, and said composition having sufficient light transmission for use as an ocular membrane.
Claim 11
Dependent Claim
95 words
An ocular membrane formed from a composition comprising a copolymer of a polysiloxane cross-linked by addition polymerization and a compound selected from the group consisting of: (a) esters of glycidyl alcohol with acrylic acid or methacrylic acid; and (b) maleic anhydride, nadic anhydride or hexahydrophthalic anhydride; the amount of each such compound in said copolymer being effective to impart wettability to the surface of articles formed from said copolymer but less tha that which would destroy the hydrophobic properties of said copolymer, and said composition having sufficient light transmission for use as an ocular membrane.
Claim 12
Dependent Claim
21 words
The composition of claim 1 wherein the polysiloxane is dimethylpolysiloxane having about 1% of the methyl groups substituted with vinyl groups.
Claim 13
Dependent Claim
20 words
The composition of claim 1 wherein the compound is an ester of glycidyl alcohol with acrylic acid or methacrylic acid.
Claim 14
Dependent Claim
22 words
The ocular membrane of claim 9 wherein the polysiloxane is dimethylpolysiloxane having about 1% of the methyl groups substituted with vinyl groups.
Claim 15
Dependent Claim
21 words
The ocular membrane of claim 9 wherein the compound is an ester of glycidyl alcohol with acrylic acid or methacrylic acid.
Claim 16
Dependent Claim
21 words
The composition of claim 1 wherein a 1 mil thickness of said composition possesses a light transmission greater than about 85%.
Claim 17
Dependent Claim
21 words
The ocular membrane of 9 wherein a 1 mil thickness of the composition possesses a light transmission of greater than 85%.
Claim 18
Dependent Claim
21 words
The ocular membrane of 9 wherein a 1 mil thickness of the composition possesses a light transmission of greater than 85%.
References Cited (Backward Citations)
US3661816A
Cited
US4070526A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |