US4673539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for thermoformed articles
Assignee: 3M Co
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Filing: 1985-05-17
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Granted: 1987-06-16
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Expires: 2005-05-17
Abstract
Abstract A process for preparing shaped articles and shaped hydrogel articles including ophthalmic devices comprises the steps of preparing a polymer or copolymer comprising units derived from an ethylenically-unsaturated monomer bearing at least one trihaloacetoxy-substituent group, thermoforming said polymer by heating in a mold or in sheet-form at a temperature in the range of 100° to 400° C. for about 5 seconds to 15 minutes, and then cooling said polymer, to provide a shaped article, optionally, solvolyzing the resulting shaped article to provide a hydroxy-substituted polymeric shaped article, and optionally hydrating said hydroxy-substituted polymeric shaped article to provide a shaped hydrogel article.
Inventors
- 👤 W. James Hammar
- 👤 Ronald F. Ofstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:23
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08L; C08L31/00; C08L31/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
84 words
A process for preparing a hydrogel precursor ophthalmic shaped article comprising the step: a. thermoforming an uncrosslinked polymer having a softening temperature of at least 100° C. comprising the product of an ethylenically-unsaturated monomer bearing at least one trihaloacetoxy-substituent group, by heating in a mold or pressing into sheets of films at a temperature in the range of 150° to 400° C. for 5 seconds to 15 minutes, and then cooling the resulting thermoformed polymer, to provide a thermoplastic, hydrogel precursor ophthalmic shaped article.
Claim 2
Dependent Claim
84 words
A process for preparing a hydrogel precursor ophthalmic shaped article comprising the step: a. thermoforming an uncrosslinked polymer having a softening temperature of at least 100° C. comprising the product of an ethylenically-unsaturated monomer bearing at least one trihaloacetoxy-substituent group, by heating in a mold or pressing into sheets of films at a temperature in the range of 150° to 400° C. for 5 seconds to 15 minutes, and then cooling the resulting thermoformed polymer, to provide a thermoplastic, hydrogel precursor ophthalmic shaped article.
Claim 3
Dependent Claim
12 words
The process according to claim 1 wherein said monomer is vinyl trifluoroacetate.
Claim 4
Dependent Claim
23 words
The process according to claim 2 wherein said units of vinyl trifluoroacetate are present in an amount of at least 95 weight percent.
Claim 5
Dependent Claim
15 words
The process according to claim 1 wherein said monomer is trihaloacetoxyethyl acrylate or trihaloacetoxyethyl methacrylate.
Claim 6
Dependent Claim
18 words
The process according to claim 1 wherein said monomer is an isopropyl or n-propyl acrylate or methacrylate ester.
Claim 7
Dependent Claim
28 words
The process according to claim 5 wherein said units of isopropyl or n-propyl acrylate or methacrylate ester are present in an amount of at least 50 weight percent.
Claim 8
Dependent Claim
21 words
The process according to claim 1 wherein said polymer is obtained by copolymerization of said monomer with additional compatible ethylenically-unsaturated comonomers.
Claim 9
Dependent Claim
15 words
The process according to claim 7 wherein said comonomers are vinyl esters or disubstituted ethylenes.
Claim 10
Dependent Claim
20 words
The process according to claim 7 wherein said comonomers are (a) vinyl esters, (b) vinyl ethers, or (c) disubstituted ethylenes.
Claim 11
Dependent Claim
26 words
The process according to claim 9 wherein said comonomer is a disubstituted ethylene selected from the group consisting of maleic anhydride, dimethyl itaconate, and monoethyl fumarate.
Claim 12
Dependent Claim
33 words
The process according to claim 7 wherein said monomer is an acrylate or methacrylate and said comonomer is vinyl acetate, vinyl perfluoro-n-butyrate, vinyl formate, methyl methacrylate, ethyl methacrylate, ethoxyethyl methacrylate, or propyl methacrylate.
Claim 13
Dependent Claim
19 words
The process according to claim 7 wherein said monomer is vinyl trifluoroacetate and said comonomer is a vinyl ether.
Claim 14
Dependent Claim
21 words
The process according to claim 1 wherein said ethylenically-unsaturated monomer is present in an amount of 95 weight percent or greater.
Claim 15
Dependent Claim
19 words
The process according to claim 1 wherein said thermoforming process takes place at a temperature of about 200° C.
Claim 16
Dependent Claim
83 words
A process for preparing a hydrogel precursor ophthalmic shaped article comprising the step: a. thermoforming an uncrosslinked polymer having a softening temperature of at least 100° C. comprising vinyl trifluoroacetate present in an amount of at least 95 weight percent, by heating in a mold or pressing into sheets of films at a temperature in the range of 150° to 400° C. for 5 seconds to 15 minutes, and then cooling said thermoformed polymer, to provide a thermoplastic, hydrogel precursor ophthalmic shaped article.
Claim 17
Dependent Claim
83 words
A process for preparing a hydrogel precursor ophthalmic shaped article comprising the step: a. thermoforming an uncrosslinked polymer having a softening temperature of at least 100° C. comprising vinyl trifluoroacetate present in an amount of at least 95 weight percent, by heating in a mold or pressing into sheets of films at a temperature in the range of 150° to 400° C. for 5 seconds to 15 minutes, and then cooling said thermoformed polymer, to provide a thermoplastic, hydrogel precursor ophthalmic shaped article.
References Cited (Backward Citations)
US2436144A
Cited
US2464120A
Cited
US3220960A
Cited
US3361858A
Cited
US3470124A
Cited
US3391130A
Cited
US4257842A
Cited
US4081600A
Cited
JPS56116A
Cited
US4528325A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
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