US4442141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of cellulose acetate butyrate contact lenses
Assignee: PBH Inc
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Filing: 1982-11-01
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Granted: 1984-04-10
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Expires: 2002-11-01
Abstract
Abstract This disclosure describes the treatment of cellulose acetate butyrate contact lenses which are rendered hydrophilic by contacting said lenses with a treating agent which increases the hydrophilicity of said lenses. The treating agent is ammoniacal salt, alkali-metal hydroxide, strong mineral acid, benzene sulfonic acid, alkali metal borohydride or organometallic compound.
Inventors
- 👤 Drahoslav Lim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:48
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; C08J2301/00; C08J2301/08; C08J2301/14
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
55 words
A process for rendering cellulose acetate butyrate contact lenses hydrophilic which comprises contacting said lenses with a treating agent for a period of time sufficient to increase the hydrophilicity of said lenses; wherein the treating agent is ammoniacal salt, alkali metal hydroxide, a strong mineral acid, benzene sulfonic acid, alkali metal borohydride, or organometallic compound.
Claim 2
Dependent Claim
55 words
A process for rendering cellulose acetate butyrate contact lenses hydrophilic which comprises contacting said lenses with a treating agent for a period of time sufficient to increase the hydrophilicity of said lenses; wherein the treating agent is ammoniacal salt, alkali metal hydroxide, a strong mineral acid, benzene sulfonic acid, alkali metal borohydride, or organometallic compound.
Claim 3
Dependent Claim
34 words
The process of rendering cellulose acetate butyrate contact lenses hydrophilic which comprises contacting said lenses with an ammoniacal salt solution for a period of time sufficient to increase the surface wettability of said lenses.
Claim 4
Dependent Claim
34 words
The process of rendering cellulose acetate butyrate contact lenses hydrophilic which comprises contacting said lenses with an ammoniacal salt solution for a period of time sufficient to increase the surface wettability of said lenses.
Claim 5
Dependent Claim
14 words
The process as in claim 2 wherein the ammonia concentration is between about 10-18%.
Claim 6
Dependent Claim
12 words
The process as in claim 3 wherein the ammonia concentration is 14.0±0.5%.
Claim 7
Dependent Claim
17 words
The process as in claim 2 wherein the ammonia is present in the form of ammonium hydroxide.
Claim 8
Dependent Claim
14 words
The process as in claim 2 wherein the salt is a non-associating strong electrolyte.
Claim 9
Dependent Claim
14 words
The process as in claim 2 wherein the salt is saturated sodium chloride solution.
Claim 10
Dependent Claim
18 words
The process as in claim 1 wherein the treating agent is a solution of an alkali metal hydroxide.
Claim 11
Dependent Claim
15 words
The process as in claim 1 wherein the treating agent is sodium or lithium borohydride.
Claim 12
Dependent Claim
13 words
The process as in claim 9 wherein the organometallic compound is n-butyl lithium.
Claim 13
Dependent Claim
14 words
The process as in claim 1 wherein the treating agent is an organometallic compound.
Claim 14
Dependent Claim
35 words
The process as in claim 1 wherein additional hydrophilicity is imparted to the lens by further treatment of the said lenses with chloro- or bromoacetic acid salts in the presence of an alkali metal hydroxide.
References Cited (Backward Citations)
US4168112A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |