US4769073A
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Ceric oxide/cerous salt organic glass polishing compositions
Assignee: Rhodia Chimie SAS
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Filing: 1987-09-28
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Granted: 1988-09-06
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Expires: 2007-09-28
Abstract
Abstract Cerium-based polishing compositions, well adapted for the rapid and efficient polishing of organic glass surfaces, e.g., plastic ophthalmic lenses and plastic sheet material, are comprised of intimate admixture of particulate ceric oxide and a water soluble cerous salt.
Inventors
- 👤 Francis Tastu
- 👤 Pierre Melard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:45
CPC Classifications
C; C09; C09G; C09G1/00; C09G1/02; C03; C03C; C03C19/00; C09K; C09K3/00; C09K3/14; C09K3/1454
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
40 words
A cerium-based composition of matter adapted for the polishing of organic glass surfaces, comprising intimate admixture of particulate ceric oxide and at least 0.2% by weight of a water soluble cerous (III) salt based on the weight of ceric oxide.
Claim 2
Dependent Claim
40 words
A cerium-based composition of matter adapted for the polishing of organic glass surfaces, comprising intimate admixture of particulate ceric oxide and at least 0.2% by weight of a water soluble cerous (III) salt based on the weight of ceric oxide.
Claim 3
Dependent Claim
17 words
The cerium-based composition as defined by claim 1, comprising at least 30% by weight of ceric oxide.
Claim 4
Dependent Claim
23 words
The cerium-based composition a defined by claim 1, said particulate ceric oxide comprising a powder having particle sizes less than about 20 μm.
Claim 5
Dependent Claim
21 words
The cerium-based composition as defined by claim 3, said powder having particle sizes ranging from about 0.1 μm to 10 μm.
Claim 6
Dependent Claim
25 words
The cerium-based composition as defined by claim 3, said particulate ceric oxide having a specific surface ranging from about 1 to 35 m 2 /g.
Claim 7
Dependent Claim
25 words
The cerium-based composition as defined by claim 5, said particulate ceric oxide having a specific surface ranging from about 3 to 10 m 2 /g.
Claim 8
Dependent Claim
20 words
The cerium-based composition as defined by claim 1, further comprising at least one rare earth oxide other than ceric oxide.
Claim 9
Dependent Claim
46 words
The cerium-based composition as defined by claim 1, further comprising a pyrosilicate of the formula Ln 2-x Ce x Si 2 O 7 in which Ln is a lanthanide or yttrium and x is a number greater than or equal to 0 and less than 2.
Claim 10
Dependent Claim
23 words
The cerium-based composition as defined by claim 1, further comprising at least one colorless oxide of a trivalent rare earth other than cerium.
Claim 11
Dependent Claim
24 words
The cerium-based composition as defined by claim 9, said other trivalent rare earth comprising lanthanum, sumarium, europium, gadolinium, dysprosium, thulium, ytterbium, lutecium or yttrium.
Claim 12
Dependent Claim
11 words
The cerium-based composition as defined by claim 10, comprising lanthanum sesquioxide.
Claim 13
Dependent Claim
22 words
The cerium-based composition as defined by claim 1, comprising ceric oxide, lanthanum oxide, at least one other rare earth oxide, and silica.
Claim 14
Dependent Claim
13 words
The cerium-based composition as defined by claim 1, comprising an inorganic cerous salt.
Claim 15
Dependent Claim
13 words
The cerium-based composition as defined by claim 1, comprising an organic cerous salt.
Claim 16
Dependent Claim
15 words
The cerium-based composition as defined by claim 13, comprising cerium (III) chloride, nitrate or sulfate.
Claim 17
Dependent Claim
12 words
The cerium-based composition as defined by claim 15, comprising cerium (III) nitrate.
Claim 18
Dependent Claim
23 words
The cerium-based composition as defined by claim 1, wherein said cerous salt comprises from 0.2% to 5% by weight of said ceric oxide.
Claim 19
Dependent Claim
23 words
The cerium-based composition as defined by claim 17, wherein said cerous salt comprises from 0.5% to 1.5% by weight of said ceric oxide.
Claim 20
Dependent Claim
18 words
The cerium-based composition as defined by claim 1, wherein said ceric oxide is impregnated with said cerous salt.
Claim 21
Dependent Claim
94 words
The cerium-based composition as defined by claim 1, said ceric oxide comprising those particulates produced by simultaneously and continuously mixing a solution of a cerium salt, a basic solution and a solution of at least one acid and/or salt, the anion or anions of which are adapted to form insoluble rare earth compounds, the number of basic equivalents introduced being equal to or greater than the number of cerium equivalents and the pH of the reaction medium being higher than 6, and then filtering the precipitate which results and drying and calcining such precipitate.
Claim 22
Dependent Claim
22 words
The cerium-based composition as defined by claim 20, said reaction medium comprising an aqueous solution of at least one trivalent rare earth.
Claim 23
Dependent Claim
22 words
The cerium-based composition as defined by claim 20, said anion or anions comprising a fluoride, a sulfate, a borate or a phosphate.
Claim 24
Dependent Claim
79 words
The cerium-based composition as defined by claim 1, said ceric oxide comprising those particulates produced by simultaneously mixing a solution of a cerium salt, a basic solution, an aqueous solution of the salt of at least one trivalent rare earth or yttrium and a solution of at least one oxygenated silicon compound adapted to form insoluble rare earth compounds, and then filtering the precipitate which results and drying and calcining such precipitate at a temperature greater than 850° C.
Claim 25
Dependent Claim
95 words
The cerium-based composition as defined by claim 1, said ceric oxide comprising those particulates produced by simultaneously and continuously mixing a solution of a ceric salt, a basic solution and a solution of at least one salt of a trivalent lanthanide or yttrium, the oxide of which is colorless, and wherein the number of basic equivalents introduced is greater than or equal to the number of cerium and rare earth equivalents and the pH of the reaction medium is higher than 6, and then filtering the precipitate which results and drying and calcining such precipitate.
Claim 26
Dependent Claim
13 words
A suspension, in water, of the cerium-based composition as defined by claim 1.
Claim 27
Dependent Claim
17 words
The aqueous suspension as defined by claim 25, having a concentration ranging from 50 to 600 g/l.
Claim 28
Dependent Claim
17 words
The aqueous suspension as defined by claim 26, having a concentration ranging from 250 to 450 g/l.
Claim 29
Dependent Claim
33 words
In a method for the polishing of an organic glass surface utilizing an abrasive polishing agent, the improvement which comprises, as the polishing agent therefor, the cerium-based composition as defined by claim 1.
Claim 30
Dependent Claim
33 words
In a method for the polishing of an organic glass surface utilizing an abrasive polishing agent, the improvement which comprises, as the polishing agent therefor, the aqueous suspension as defined by claim 25.
Claim 31
Dependent Claim
17 words
The polishing method as defined by claim 29, said organic glass surface comprising a plastic ophthalmic lens.
Claim 32
Dependent Claim
17 words
The polishing method as defined by claim 29, said organic glass surface comprising a plastic sheet material.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
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