US4008173A
Expired / Lapsed
US
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Defoamer composition
Assignee: PQ Corp
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Filing: 1975-04-21
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Granted: 1977-02-15
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Expires: 1995-04-21
Abstract
Abstract A composition containing finely divided synthetic, precipitated amorphous metal-silicate and an acid; said composition having a pH of 2 to 5 being suitable for use as a base for defoamers for aqueous systems.
Inventors
- 👤 Stephen A. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:02
CPC Classifications
B; B01; B01D; B01D19/00; B01D19/02; B01D19/04; B01D19/0404; B01D19/0409
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
117 words
A hydrophobic defoamer base suitable for preparing defoamers for aqueous systems, having a pH of 2 to 5.5 consisting of an amorphous, precipitated hydrophilic metal silicate having a particle size of 10 to 200 mu, the pH of said silicate being adjusted to a value of 1.8 to 5.0 by acid addition and being selected from the group consisting of aluminum silicate (alumino silicate), magnesium silicate, calcium silicate and sodium aluminum silicate (sodium alumino silicate) said hydrophilic metal silicate being rendered hydrophobic by coating with 2 to 30% of an organosiloxane having a viscosity of 10 to 3000 centistokes and heating said coated silicate at a temperature between 230° and 320° C for 4 to 20 hours.
Claim 2
Dependent Claim
117 words
A hydrophobic defoamer base suitable for preparing defoamers for aqueous systems, having a pH of 2 to 5.5 consisting of an amorphous, precipitated hydrophilic metal silicate having a particle size of 10 to 200 mu, the pH of said silicate being adjusted to a value of 1.8 to 5.0 by acid addition and being selected from the group consisting of aluminum silicate (alumino silicate), magnesium silicate, calcium silicate and sodium aluminum silicate (sodium alumino silicate) said hydrophilic metal silicate being rendered hydrophobic by coating with 2 to 30% of an organosiloxane having a viscosity of 10 to 3000 centistokes and heating said coated silicate at a temperature between 230° and 320° C for 4 to 20 hours.
Claim 3
Dependent Claim
20 words
The defoamer base of claim 1 wherein the pH of the hydrophobic metal silicate is adjusted to 1.8 to 4.0.
Claim 4
Dependent Claim
27 words
The defoamer base of claim 1 with a pH of 2.5 to 4.0 wherein the pH of the hydrophilic metal silicate is adjusted to 3 to 3.5.
Claim 5
Dependent Claim
24 words
The defoamer of claim 1 wherein the siloxane is selected from the group consisting of alkyl polysiloxanes, aryl polysiloxanes, arylalkyl polysiloxanes and alicyclic polysiloxanes.
Claim 6
Dependent Claim
22 words
The defoamer base of claim 1 wherein the siloxane is selected from the group consisting of dimethyl polysiloxane and methyl hydrogen polysiloxanes.
Claim 7
Dependent Claim
20 words
The defoamer base of claim 1 wherein the heating is carried out at a temperature between 238° and 316° C.
Claim 8
Dependent Claim
30 words
The defoamer base of claim 1 wherein the pH of the hydrophilic metal silicate is adjusted using an acid selected from the group consisting of sulfuric, hydrochloric, acetic and sulfurous.
Claim 9
Dependent Claim
53 words
The defoamer base of claim 1 wherein the acid is sulfuric and the equivalent of 3 to 40% of 100% H 2 SO 4 based on the weight of said metal silicate is used as a 20 to 65% solution of H 2 SO 4 to adjust the pH of the hydrophilic silicate.
Claim 10
Dependent Claim
17 words
The defoamer base of claim 8 wherein the sulfuric acid has a concentration of 50 to 60%.
References Cited (Backward Citations)
US3235509A
Cited
US3573222A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |