US4173491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pigmented microporous silica microspheres by spray processes
Assignee: EIDP Inc
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Filing: 1978-03-03
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Granted: 1979-11-06
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Expires: 1998-03-03
Abstract
Abstract Process for preparing pigmented microporous silica microspheres by spraying an aqueous suspension of pigment in a solution of alkali metal silicate through the air into a medium consisting of from 20% to 100% by volume of a water miscible organic liquid, the balance being water. The resulting microspheres are highly effective opacifying agents.
Inventors
- 👤 Lloyd Abrams
- 👤 Lionel S. Sandell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:06
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/3009; C01; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/64; C01P2006/00; C01P2006/10; C01P2006/12; C01P2006/16; C01P2006/60; C01P2006/80
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
131 words
A process for preparing pigmented microporous silica microspheres by the steps of (i) forming an aqueous suspension consisting essentially of particulate inorganic pigment uniformly dispersed in an aqueous solution of an alkali metal silicate, (ii) spraying the aqueous suspension of step (i) into air to form fine droplets, (iii) contacting the droplets with a medium consisting essentially of from 0% to 80% by volume of water, based on the volume of the medium, and from 20% to 100% by volume of a water miscible organic liquid, based on the volume of the medium, the pH of the medium being maintained at from 2 to 9 throughout the contacting, to form a suspension of pigmented microporous silica microspheres, and (iv) isolating the pigmented microporous silica microspheres from the suspension of step (iii).
Claim 2
Dependent Claim
131 words
A process for preparing pigmented microporous silica microspheres by the steps of (i) forming an aqueous suspension consisting essentially of particulate inorganic pigment uniformly dispersed in an aqueous solution of an alkali metal silicate, (ii) spraying the aqueous suspension of step (i) into air to form fine droplets, (iii) contacting the droplets with a medium consisting essentially of from 0% to 80% by volume of water, based on the volume of the medium, and from 20% to 100% by volume of a water miscible organic liquid, based on the volume of the medium, the pH of the medium being maintained at from 2 to 9 throughout the contacting, to form a suspension of pigmented microporous silica microspheres, and (iv) isolating the pigmented microporous silica microspheres from the suspension of step (iii).
Claim 3
Dependent Claim
24 words
Process according to claim 1 wherein the aqueous suspension of step (i) contains from 10% to 70% by weight of a particulate inorganic pigment.
Claim 4
Dependent Claim
40 words
Process according to claim 2 wherein the medium of step (iii) contains from 20% to 60% by volume of a water miscible organic liquid selected from lower aliphatic alcohols, lower aliphatic acids, ketones, glycols, glycol ethers, amines and alcohol amines.
Claim 5
Dependent Claim
23 words
Process according to claim 3 wherein the pH of the medium of step (iii) is maintained from 2 to 5 throughout the contacting.
References Cited (Backward Citations)
US3418147A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |