US4746691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of pigmenting water-absorbable plastics
Assignee: Color Optics Ltd (Partnership)
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Filing: 1987-01-20
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Granted: 1988-05-24
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Expires: 2007-01-20
Abstract
Abstract A colored opacified plastic material containing an organic binder, at least one pigment, a hydrophilic polymerizable plastic material and a cross linking agent is disclosed together with a method of making the same.
Inventors
- 👤 Ari Fuhrman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:56
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/021; B; B29; B29D; B29D11/00; B29D11/00865; B29D11/00894; B29D11/00903; C; C08; C08F; C08F251/00; C08F251/02; C08L; C08L1/00; C08L1/08; C08L1/10; C08L1/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
107 words
A method for producing a colored, water-absorbable soft contact lens blank, which comprises: (a) melting a cellulose acetate butyrate (CAB) binder; (b) pre-dispersing at least one pigment into the molten CAB; (c) cooling and crushing the pigmented CAB binder into a particulate product; (d) dispersing the particulate product in 2-hydroxyethylmethacrylate (HEMA) containing crosslinking agent, in proportions such that the resulting dispersion contains from about 96 to 99% by weight HEMA and from about 0.4 to 0.74% CAB by weight; (e) gelling the HEMA dispersion of the pigmented CAB; and (f) polymerizing the gelled dispersion within a mold to produce the desired colored, water-absorbable soft contact lens blank.
Claim 2
Independent Claim
107 words
A method for producing a colored, water-absorbable soft contact lens blank, which comprises: (a) melting a cellulose acetate butyrate (CAB) binder; (b) pre-dispersing at least one pigment into the molten CAB; (c) cooling and crushing the pigmented CAB binder into a particulate product; (d) dispersing the particulate product in 2-hydroxyethylmethacrylate (HEMA) containing crosslinking agent, in proportions such that the resulting dispersion contains from about 96 to 99% by weight HEMA and from about 0.4 to 0.74% CAB by weight; (e) gelling the HEMA dispersion of the pigmented CAB; and (f) polymerizing the gelled dispersion within a mold to produce the desired colored, water-absorbable soft contact lens blank.
Claim 3
Dependent Claim
16 words
The method according to claim 1, wherein said water-absorbable soft contact-lens blank is cured following polymerization.
Claim 4
Dependent Claim
17 words
The method according to claim 1, wherein the crosslinking agent for the HEMA is ethylene glycol dimethacrylate.
Claim 5
Dependent Claim
18 words
The method according to claim 1, wherein polymerization of the gelled dispersion is catalyzed by an organic peroxide.
Claim 6
Dependent Claim
28 words
The method according to claim 1, wherein the resulting dispersion formed in step (d) contains HEMA in a concentration range of from about 98 to 98.5% by weight.
Claim 7
Independent Claim
111 words
A method for producing a colored, water-absorbable soft contact lens, which comprises: (a) melting a cellulose acetate butyrate (CAB) binder; (b) pre-dispersing at least one pigment into the molten CAB; (c) cooling and crushing the pigmented CAB binder into a particulate product; (d) dispersing the particulate product in 2-hydroxyethylmethacrylate (HEMA) containing crosslinking agent, in proportions such that the resulting dispersion contains from about 96 to 99% by weight HEMA and from about 0.4 to 0.74% CAB by weight; (e) contacting the HEMA dispersion of the pigmented CAB with a polymerization catalyst to form a viscous colored material; and (f) spin casting the viscous colored material into a pigmented water-absorbable contact lens.
Claim 8
Independent Claim
111 words
A method for producing a colored, water-absorbable soft contact lens, which comprises: (a) melting a cellulose acetate butyrate (CAB) binder; (b) pre-dispersing at least one pigment into the molten CAB; (c) cooling and crushing the pigmented CAB binder into a particulate product; (d) dispersing the particulate product in 2-hydroxyethylmethacrylate (HEMA) containing crosslinking agent, in proportions such that the resulting dispersion contains from about 96 to 99% by weight HEMA and from about 0.4 to 0.74% CAB by weight; (e) contacting the HEMA dispersion of the pigmented CAB with a polymerization catalyst to form a viscous colored material; and (f) spin casting the viscous colored material into a pigmented water-absorbable contact lens.
Claim 9
Dependent Claim
28 words
The method according to claim 6, wherein the resulting dispersion formed in step (d) contains HEMA in a concentration range of from about 98 to 98.5% by weight.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |