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US4018853A
Expired / Lapsed
US
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Crosslinked, hydrophilic rods of pyrrolidone-methacrylate graft copolymers
Assignee: AO Inc 14 MECHANIC STREET A CORP OF
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Filing: 1976-03-08
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Granted: 1977-04-19
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Expires: 1996-03-08
Abstract
Abstract A contact lens composition, having improved dimensional stability, suitable for use in the preparation of a corrective hydrated lens or an eye bandage, comprises polymerized random graft copolymers containing (in the dry state) from 67.2% to 79.3% HEMA; from 14.25% to 35% PVP; from 0.1% to 4.04% EDMA; from 0.1% to 2.5% MA; from 0.1% to 5.0% water; from 0 to 4 ppm HQ inhibitor; and from 50 to 250 ppm MEHQ inhibitor. The contact lens composition contains from 45% to 65% water after hydration. An improved method for shaping, polymerizing, and cutting and hydrating the contact lens composition is provided. The polymerization is conducted using only a low temperature initiator, by de-gassing prior to polymerization to remove substantially all oxygen, and by conducting the initial polymerization reaction at from 23 DEG to 30 DEG C for 16 to 30 hours, during which the heat of the reaction is continuously absorbed to control the reaction exotherm. A closed, rod-shaped casting mold, lined with a polyester film material, is used and the polymeric rod obtained may be cut, machined and polished to obtain the contact lens composition. Thereafter, hydration is conducted in a buffered, 0.85% to 0.9% saline solution, at a pH of 7.0 to 7.1.
Inventors
- 👤 Albert R. Le Boeuf
- 👤 William R. Grovesteen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:57
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/07; A61L15/12; A61L15/125; B; B29; B29D; B29D11/00; B29D11/00009; B29D11/00038; B29D11/00067; B29D11/00125; B29D11/00134; C; C08; C08F; C08F271/00; C08F271/02; G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
31 words
A cast, substantially strain-free, dimensionally stable, sparingly crosslinked, hydrophilic, substantially cylindrical polymeric rod consisting essentially of polymerized random graft copolymers containing: 1. from about 67.2% to about 79.3% hydroxyethyl methacrylate; 2.
Claim 2
Dependent Claim
31 words
A cast, substantially strain-free, dimensionally stable, sparingly crosslinked, hydrophilic, substantially cylindrical polymeric rod consisting essentially of polymerized random graft copolymers containing: 1. from about 67.2% to about 79.3% hydroxyethyl methacrylate; 2.
Claim 3
Dependent Claim
239 words
from about 14.25% to about 35% poly-N-vinyl pyrrolidone; 3. from about 0.1% to about 4.04% ethylene glycol dimethacrylate; 4. from about 0.1% to about 2.5% methacrylic acid; 5. from about 0.1% to about 5.0% water; 6. from about 0 to about 4.0 ppm, based on the weight of hydroxyethyl methacrylate monomer, of hydroquinone inhibitor; and 7. from about 50 to 250 ppm, based on the weight of hydroxyethyl methacrylate monomer, of the methyl ether of hydroquinone, as an inhibitor; said polymeric rod having been polymerized in a three stage polymerization process comprising: a. a first stage, using only a low temperature polymerization inhibitor, with substantially all the oxygen having been removed from the polymerization mix prior to and during the polymerization reaction; the initial polymerization reaction being conducted at from about 23° to about 30° C for from about 16 to about 36 hours, with the heat of the reaction continuously absorbed to control the reaction exotherm; followed by b. a second stage wherein the product of (a) is heated to a temperature of from about 40° to about 80° C in the absence of any additional polymerization initiator, without control of the reaction exotherm, for from two to six hours; followed by c. a third stage polymerization, wherein the product of (b) is heated to a temperature of from about 105° to about 125° C, in the absence of any additional polymerization initiator, for from 24 to 36
Claim 4
Dependent Claim
239 words
from about 14.25% to about 35% poly-N-vinyl pyrrolidone; 3. from about 0.1% to about 4.04% ethylene glycol dimethacrylate; 4. from about 0.1% to about 2.5% methacrylic acid; 5. from about 0.1% to about 5.0% water; 6. from about 0 to about 4.0 ppm, based on the weight of hydroxyethyl methacrylate monomer, of hydroquinone inhibitor; and 7. from about 50 to 250 ppm, based on the weight of hydroxyethyl methacrylate monomer, of the methyl ether of hydroquinone, as an inhibitor; said polymeric rod having been polymerized in a three stage polymerization process comprising: a. a first stage, using only a low temperature polymerization inhibitor, with substantially all the oxygen having been removed from the polymerization mix prior to and during the polymerization reaction; the initial polymerization reaction being conducted at from about 23° to about 30° C for from about 16 to about 36 hours, with the heat of the reaction continuously absorbed to control the reaction exotherm; followed by b. a second stage wherein the product of (a) is heated to a temperature of from about 40° to about 80° C in the absence of any additional polymerization initiator, without control of the reaction exotherm, for from two to six hours; followed by c. a third stage polymerization, wherein the product of (b) is heated to a temperature of from about 105° to about 125° C, in the absence of any additional polymerization initiator, for from 24 to 36
Claim 5
Dependent Claim
74 words
hours. 2. A cast, substantially strain-free, dimensionally stable, sparingly crosslinked, hydrophilic, substantially cylindrical polymeric rod according to claim 1 wherein: 1. about 75.7% hydroxyethyl methacrylate, 2. about 19.4% poly-N-vinyl pyrrolidone, 3. about 0.54% ethylene glycol dimethacrylate, 4. about 1.2% methacrylic acid, 5. about 3.0% water, and 6. from about 100 to 200 ppm, based on the weight of hydroxyethyl methacrylate monomer, of the methyl ether of hydroquinone inhibitor are present in the polymeric rod.
Claim 6
Dependent Claim
36 words
A cast, substantially strain-free, dimensionally stable, sparingly crosslinked, hydrophilic, substantially cylindrical polymeric rod according to claim 2 wherein the second stage polymerization reaction is conducted at a temperature of about 70° C for about 2 hours.
Claim 7
Dependent Claim
36 words
A cast, substantially strain-free, dimensionally stable, sparingly crosslinked, hydrophilic, substantially cylindrical polymeric rod according to claim 2 wherein the third stage polymerization reaction is conducted at a temperature of about 110° C for about 24 hours.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |