US4549892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing hollow, bilayered silicate microspheres
Assignee: PQ Corp
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Filing: 1982-09-22
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Granted: 1985-10-29
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Expires: 2002-09-22
Abstract
Abstract This invention relates to a process for producing a hollow microsphere wherein the inner portion of the shell of which comprises the reaction product of a silicate and a first insolubilizing agent, the outer portion of the shell of which comprises the reaction product of a silicate and a second insolubilizing agent and wherein the equivalent ratio of silicate to, respectively, the first and second insolubilizing agent is less in respect of said inner portion than said outer portion.
Inventors
- 👤 Alfred G. Baker
- 👤 Andrew J. Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:24
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/04; B01J13/043; C; C09; C09C; C09C1/00; C09C1/28; C01; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/34; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/10; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2996
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
133 words
A process for producing hollow microspheres comprising (a) mixing together an aqueous solution (i) containing a silicate and an aqueous solution (ii) containing a first insolubilizing agent to form a feedstock, (b) forming the feedstock into droplets (c) spray drying the droplets to form hollow microspheres, and (d) applying to the droplets during the spray drying, an aqueous solution (iii) of a second insolubilizing agent to produce hollow microspheres the inner portion of the shell of which comprises the reaction product of the silicate and the first insolubilizing agent, the outer portion of which comprises the reaction product of the silicate and the second insolubilizing agent and wherein the equivalent ratio of silicate to, respectively the first and second insolubilizing agent is less in respect of said inner portion than said outer portion.
Claim 2
Dependent Claim
133 words
A process for producing hollow microspheres comprising (a) mixing together an aqueous solution (i) containing a silicate and an aqueous solution (ii) containing a first insolubilizing agent to form a feedstock, (b) forming the feedstock into droplets (c) spray drying the droplets to form hollow microspheres, and (d) applying to the droplets during the spray drying, an aqueous solution (iii) of a second insolubilizing agent to produce hollow microspheres the inner portion of the shell of which comprises the reaction product of the silicate and the first insolubilizing agent, the outer portion of which comprises the reaction product of the silicate and the second insolubilizing agent and wherein the equivalent ratio of silicate to, respectively the first and second insolubilizing agent is less in respect of said inner portion than said outer portion.
Claim 3
Dependent Claim
25 words
A process for producing hollow microspheres as claimed in claim 1, wherein the silicate is selected from the group consisting of sodium or potassium silicate.
Claim 4
Dependent Claim
20 words
A process for producing hollow microspheres as claimed in claim 1, wherein the first insolubilizing agent is a weak acid.
Claim 5
Dependent Claim
27 words
A process for producing hollow microspheres as claimed in claim 1, wherein the first insolubilizing agent is selected from the group consisting of boric or phosphoric acid.
Claim 6
Dependent Claim
39 words
A process for producing hollow microspheres as claimed in claim 1 wherein the second insolubilizing agent is selected from the group consisting of weak acids and salts capable of reacting with the silicate to form an insoluble reaction product.
Claim 7
Dependent Claim
44 words
A process for producing hollow microspheres as claimed in claim 5, wherein said salts are selected from the group consisting of calcium salts, magnesium salts, aluminium salts and salts of polyvalent metals capable of reacting with the silicate to form an insoluble reaction product.
Claim 8
Dependent Claim
27 words
A process for producing hollow microspheres as claimed in, claim 5, wherein the second insolubilizing agent is selected from the group consisting of boric and phosphoric acid.
Claim 9
Dependent Claim
23 words
A process for producing hollow microspheres as claimed in claim 1 wherein the second insolubilizing agent is different to the first insolubilzing agent.
Claim 10
Dependent Claim
22 words
A process for producing hollow microspheres as claimed in claim 1, wherein the first and the second insolubilizing agents are the same.
Claim 11
Dependent Claim
23 words
A process for producing hollow microspheres as claimed in claim 9, wherein the first and the second insolubilizing agents are both boric acid.
Claim 12
Dependent Claim
25 words
A process for producing hollow microspheres as claimed in claim 10, wherein potassium or sodium silicate is present in solution (i) as 25-55% by weight.
Claim 13
Dependent Claim
23 words
A process for producing hollow microspheres as claimed in claim 10, wherein boric acid is present in solution (ii) as 3-20% by weight.
Claim 14
Dependent Claim
33 words
A process for producing hollow microspheres as claimed in claim 10, wherein a solution (iv) containing an hydroxylated and/or an oxygenated organic compound is added to solution (ii) prior to mixing step (a).
Claim 15
Dependent Claim
19 words
A process for producing hollow microspheres as claimed in claim 13, wherein the organic compound is ethylene glycol diacetate.
Claim 16
Dependent Claim
27 words
A process for producing hollow microspheres as claimed in claim 10, wherein the feedstock is held for 1-2 hours after mixing step (a) prior to step (b).
Claim 17
Dependent Claim
33 words
A process for producing hollow microspheres as claimed in claim 1, wherein solution (iii) is applied to the droplets by being sprayed in close proximity to the initiation of the spray of droplets.
Claim 18
Dependent Claim
17 words
A proces for producing hollow microspheres as claimed in claim 15, wherein solution (iii) additionally contains EGDA.
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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) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |