US4340642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface modified hollow microspheres
Assignee: PQ Corp
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Filing: 1980-06-20
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Granted: 1982-07-20
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Expires: 2000-06-20
Abstract
Abstract Non-fused hollow glass microspheres that consist primarily of silicate are rendered more water-resistant by treatment with multivalent metals. The hollow microspheres are slurried with water and then a solution of a multivalent metal salt such as Al 2 (SO 4 ) 3 is added to the slurry. The rate of the addition is controlled so that the pH can be regulated. Separating, washing and drying complete the preparation.
Inventors
- 👤 David I. Netting
- 👤 Bruce D. Spivack
- 👤 James P. Cunnion, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:12
CPC Classifications
C; C03; C03C; C03C21/00; C03C21/001; C03B; C03B19/00; C03B19/10; C03B19/107; C03B19/1075; C03C11/00; C03C11/002; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/252; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2996
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
121 words
Water resistant hollow microspheres that have not been exposed to fusion or sintering temperatures, said microspheres being characterized by a weight % ratio of "polysalt" solids to sodium silicate solids of 0.02:1 to 2.0:1, said polysalt being a colloidal inorganic salt of an alkali metal and/or ammonium cations wherein the anion to cation ratio is reduced when the salt is dissolved and becomes hydrolized and said sodium silicate containing 1.5 to 4.0 moles of SiO 2 per mole of Na 2 O; a particle size of about 35 to 2000 microns; a bulk density of 2 to 20 lbs/cu ft, less than 7% moisture and 0.1 to 5.0% of a multivalent metal that decreases the solubility of the microsphere in water.
Claim 2
Dependent Claim
121 words
Water resistant hollow microspheres that have not been exposed to fusion or sintering temperatures, said microspheres being characterized by a weight % ratio of "polysalt" solids to sodium silicate solids of 0.02:1 to 2.0:1, said polysalt being a colloidal inorganic salt of an alkali metal and/or ammonium cations wherein the anion to cation ratio is reduced when the salt is dissolved and becomes hydrolized and said sodium silicate containing 1.5 to 4.0 moles of SiO 2 per mole of Na 2 O; a particle size of about 35 to 2000 microns; a bulk density of 2 to 20 lbs/cu ft, less than 7% moisture and 0.1 to 5.0% of a multivalent metal that decreases the solubility of the microsphere in water.
Claim 3
Dependent Claim
16 words
The hollow microsphere of claim 1 wherein the multivalent metal is calcium, magnesium, aluminum or zinc.
Claim 4
Dependent Claim
20 words
The microsphere of either of claims 1 or 2 wherein said polysalt is ammonium pentaborate, sodium pentaborate or sodium hexametaphosphate.
Claim 5
Dependent Claim
16 words
The hollow microsphere of claim 1 wherein the multivalent metal is calcium, magnesium, aluminum or zinc.
Claim 6
Dependent Claim
96 words
Water resistant hollow microspheres that have not been exposed to fusion or sintering temperatures, said microspheres being characterized by a weight % ratio of ammonium pentaborate, sodium pentaborate or sodium hexametaphosphate solids to sodium silicate solids of 0.02:1 to 2.0:1, said sodium silicate containing 1.5 to 4.0 moles of SiO 2 per mole of Na 2 O; a particle size of about 35 to 2000 microns; a bulk density of 2 to 20 lbs/cu ft; less than 7% moisture and 0.1 to 5.0% of a multivalent metal that decreases the solubility of the microspheres in water.
Claim 7
Dependent Claim
96 words
Water resistant hollow microspheres that have not been exposed to fusion or sintering temperatures, said microspheres being characterized by a weight % ratio of ammonium pentaborate, sodium pentaborate or sodium hexametaphosphate solids to sodium silicate solids of 0.02:1 to 2.0:1, said sodium silicate containing 1.5 to 4.0 moles of SiO 2 per mole of Na 2 O; a particle size of about 35 to 2000 microns; a bulk density of 2 to 20 lbs/cu ft; less than 7% moisture and 0.1 to 5.0% of a multivalent metal that decreases the solubility of the microspheres in water.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-19 | 1986-01-18 | 1986-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-19 | 1990-01-18 | 1990-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-19 | 1994-01-18 | 1994-07-20 | $7700.00 | Window Closed / Lapsed |