Patent US3894129A successfully refreshed from Google Patents.
US3894129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacture of strain free contact lenses
Assignee: American Optical Corp
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Filing: 1973-03-15
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Granted: 1975-07-08
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Expires: 1993-03-15
Abstract
Abstract A dispersion of a hydroxy methacrylate ester and a poly vinyl pyrrolidone (with low and medium temperature initiators) is cast in a shaping mold and is polymerized in the absence of oxygen by a low temperature thermal polymerization followed by a higher thermal post polymerization. The resultant material may be shaped into a contact lens form, and these lenses may then be equilibrated by hydrating in normal saline solution.
Inventors
- 👤 Donald O Hoffman
- 👤 Edward Z Zdrok
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:44
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; B; B29; B29C; B29C33/00; B29C33/0038; B29D; B29D11/00; B29D11/00009; B29D11/00038; C; C08; C08F; C08F271/00; C08F271/02; B29L; B29L2031/00; B29L2031/76; B29L2031/7602
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
108 words
THE METHOD OF MANUFACTURING A STRAIN FREE, HYDROSCOPIC SOLID POLYMERIZED PRODUCT SUITABLE FOR CONTRACT LENSES AND THE LIKE WHICH IMBIBES 40-80 PER CENT BY WEIGHT WATER, COMPRISING. PREPARING A MIXTURE OF 20-45 PERCENT BY WEIGHT OF A SOLID HIGH MOLECULAR WEIGHT POLYVINYL PYRROLIDONE AND 80-55 PERCENT BY WEIGHT OF A MONOMETHACRYLATE ESTER OF A GLYCOL SELECTED FROM THE GROUP CONSISTING OF ETHYLENE GLYCOL AND PROPYLENE GLYCOL, IN THE PRESENCE OF A LOW TEMPERATURE INITIATOR AND A MEDIUM TEMPERATURE INITIATOR, AND SAID MIXTURE CONTAINING NOT MORE THAN ABOUT 1.6 PERCENT B WEIGHT OF METHACRYLIC ACID AND NOT MORE THAN ABOUT 1.0 PERCENT BY WEIGHT OF AN ALKYL GLYCOL DIMETHACRYLATE,
Claim 2
Independent Claim
108 words
THE METHOD OF MANUFACTURING A STRAIN FREE, HYDROSCOPIC SOLID POLYMERIZED PRODUCT SUITABLE FOR CONTRACT LENSES AND THE LIKE WHICH IMBIBES 40-80 PER CENT BY WEIGHT WATER, COMPRISING. PREPARING A MIXTURE OF 20-45 PERCENT BY WEIGHT OF A SOLID HIGH MOLECULAR WEIGHT POLYVINYL PYRROLIDONE AND 80-55 PERCENT BY WEIGHT OF A MONOMETHACRYLATE ESTER OF A GLYCOL SELECTED FROM THE GROUP CONSISTING OF ETHYLENE GLYCOL AND PROPYLENE GLYCOL, IN THE PRESENCE OF A LOW TEMPERATURE INITIATOR AND A MEDIUM TEMPERATURE INITIATOR, AND SAID MIXTURE CONTAINING NOT MORE THAN ABOUT 1.6 PERCENT B WEIGHT OF METHACRYLIC ACID AND NOT MORE THAN ABOUT 1.0 PERCENT BY WEIGHT OF AN ALKYL GLYCOL DIMETHACRYLATE,
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said low temperature initiator is di-(secondary-butyl) peroxy dicarbonate and said medium temperature initiator is benzoyl peroxide.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said mold is enclosed by a covering of paraffin.
Claim 5
Dependent Claim
20 words
The method of claim 3 wherein said paraffin has a melting point which is lower than said first polymerizing temperature.
Claim 6
Dependent Claim
15 words
The method of claim 3 wherein paraffin is applied to said mold as liquid paraffin.
Claim 7
Dependent Claim
28 words
The method of claim 1 wherein said mold is completely filled, and a cover is placed in contact with said mixture to thereby exclude oxygen from said mixture.
Claim 8
Dependent Claim
11 words
The method of claim 5 wherein said cover is a film.
Claim 9
Dependent Claim
12 words
The method of claim 5 wherein said cover is a neoprene disc.
Claim 10
Independent Claim
127 words
The method of manufacturing a strain free, hydroscopic solid polymerized product suitable for contact lenses and the like which imbibes 40-80 percent water by weight, comprising: mixing 80-55 weight percent of 2-hydroxy ethyl methacrylate and 20-45 weight percent of polyvinyl pyrrolidone, not more than about 1.5 weight percent of methacrylic acid and not more than about 0.7 weight percent of ethylene glycol dimethacrylate, and in the presence of a low temperature and a medium temperature initiator, pouring said mixture in a cup-shaped mold to less than completely full, completely filling said mold with liquid paraffin to exclude oxygen from said mixture, polymerizing said mixture for 2-24 hours at a temperature of 40*-60*C, and curing said polymerized mixture for 1/2 to 2 hours at a temperature of 90*-120*C.
Claim 11
Independent Claim
127 words
The method of manufacturing a strain free, hydroscopic solid polymerized product suitable for contact lenses and the like which imbibes 40-80 percent water by weight, comprising: mixing 80-55 weight percent of 2-hydroxy ethyl methacrylate and 20-45 weight percent of polyvinyl pyrrolidone, not more than about 1.5 weight percent of methacrylic acid and not more than about 0.7 weight percent of ethylene glycol dimethacrylate, and in the presence of a low temperature and a medium temperature initiator, pouring said mixture in a cup-shaped mold to less than completely full, completely filling said mold with liquid paraffin to exclude oxygen from said mixture, polymerizing said mixture for 2-24 hours at a temperature of 40*-60*C, and curing said polymerized mixture for 1/2 to 2 hours at a temperature of 90*-120*C.
Claim 12
Dependent Claim
22 words
The method of claim 9 wherein 78.24 weight percent of 2-hydroxy ethyl methacrylate is polymerized with 20 weight percent of polyvinyl pyrrolidone.
Claim 13
Dependent Claim
36 words
The method of claim 9 wherein said low temperature initiator is di-(secondary-butyl) peroxy dicarbonate in an amount of 0.1 weight percent and said medium temperature initiator is benzoyl peroxide in an amount of 0.1 weight percent.
References Cited (Backward Citations)
US2511436A
Cited
US3361858A
Cited
US3496254A
Cited
US3265763A
Cited
US3413391A
Cited
US3621079A
Cited
US3639524A
Cited
US3792028A
Cited
US3700761A
Cited
US3761208A
Cited
US3807398A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |