US4581252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for providing optical products made of glassy polymers with a variable refractive index
Assignee: Arkema France SA
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Filing: 1985-08-14
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Granted: 1986-04-08
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Expires: 2005-08-14
Abstract
Abstract Light guide articles made of glassy polymers are provided with a gradually varying refractive index by immersion in a solution of a substance having a different refractive index and which swells the glassy polymer under the immersion conditions and thereafter heating the article under conditions to remove the solvent and leave the substance of different refractive index under the surface of the article.
Inventors
- 👤 Gaetano Guerra
- 👤 Umberto Mandara
- 👤 Antonio Moschetti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:27
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/04; C08J7/06; C08J7/065; B; B05; B05D; B05D5/00; B05D5/06; B29; B29D; B29D11/00; B29D11/00663; C08J7/046; C08J2333/00; C08J2333/04; C08J2333/06; C08J2333/10; C08J2333/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
A process for providing optical articles prepared from a glassy polymer having a glass transition temperature higher than the room temperature with a gradually varying refractive index, which process consists of the following steps: (1) immersing said article in a solution of a substance having a refractive index different from the refractive index of the glassy polymer by at least 5.10 -2 units, in a solvent of said substance having a low boiling point and which swells the glassy polymer under the immersion conditions, and (2) heating the article so obtained at a temperature of 20° C. to 150° C. to remove the solvent and leave the substance having the different refractive index in the surface layer of the optical article to a depth of at least 20 microns.
Claim 2
Dependent Claim
129 words
A process for providing optical articles prepared from a glassy polymer having a glass transition temperature higher than the room temperature with a gradually varying refractive index, which process consists of the following steps: (1) immersing said article in a solution of a substance having a refractive index different from the refractive index of the glassy polymer by at least 5.10 -2 units, in a solvent of said substance having a low boiling point and which swells the glassy polymer under the immersion conditions, and (2) heating the article so obtained at a temperature of 20° C. to 150° C. to remove the solvent and leave the substance having the different refractive index in the surface layer of the optical article to a depth of at least 20 microns.
Claim 3
Dependent Claim
42 words
The process according to claim 1, in which the substance having a different refractive index has a low volatility, a boiling temperature higher than 80° C., a good compatability with the polymer of the optical article and a stability to light radiations.
Claim 4
Dependent Claim
46 words
The process according to claim 2, in which the substance having a different refractive index is selected from the group consisting of fluorinated alcohols, fluorinated acids, fluorinated amines, fluorinated acrylates, esters, anhydrides, inorganic acids and hydroxides, inorganic halides, inorganic nitrates, halogenated alkanes, aromatic hydrocarbons and alkoxy-silanes.
Claim 5
Dependent Claim
35 words
The process according to claim 1, in which the substance having a refractive index different from that of the glassy polymer is present in the immersion solution in a concentration up to 100% by weight.
Claim 6
Dependent Claim
33 words
The process according to claim 1, in which the solvent having a low boiling point is selected from the group consisting of the alcohols, esters, ketones, glycols and gasoline, having low molecular weight.
Claim 7
Dependent Claim
19 words
The process according to claim 5, in which the low boiling point solvent is used in admixture with water.
Claim 8
Dependent Claim
30 words
The process according to claim 1, in which the bath temperature ranges from the room temperature to 100° C. and the immersion time varies from 1 minute to 200 minutes.
References Cited (Backward Citations)
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Cited
US3745042A
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US3865619A
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US3999834A
Cited
US4046457A
Cited
US4049846A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |