Patent US3975308A successfully refreshed from Google Patents.
US3975308A
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Preparation of pyrophosphates
Assignee: Unifrax I LLC
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Filing: 1975-02-07
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Granted: 1976-08-17
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Expires: 1995-02-07
Abstract
Abstract A method for the preparation of pyrophosphates such as SiP2O7 is disclosed, whereby the undesired formation of by-products such as Si2P2O9 is minimized. Such pyrophosphates are particularly suitable for the formation of solid semi-conductor diffusion sources, wherein the presence of by-product is seriously detrimental.
Inventors
- 👤 Thomas A. Myles
- 👤 Curtis E. Zimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:05
CPC Classifications
C; C30; C30B; C30B31/00; C30B31/06; C30B31/16; C30B31/165; Y; Y10; Y10S; Y10S252/00; Y10S252/95; Y10S252/951
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A process for preparation of pyrophosphates selected from the group consisting of SiP 2 O 7 , ZrP 2 O 7 , Ba 2 P 2 O 7 , Pb 2 P 2 O 7 , Mg 2 P 2 O 7 , and Mn 2 P 2 O 7 which comprises: a. preparing a blend of an oxide selected from the group consisting of oxides of silicon, zirconium, barium, lead, magnesium and manganese with a stoichiometric excess of at least 40 percent of a source of P 2 O 5 ; b. placing said blend in a reaction vessel which is non-reactive with the materials in the blend; c. raising the temperature of said blend and reaction vessel to a reaction temperature at a rate of at least 200°C per hour; d. maintaining said blend and reaction vessel at said reaction temperature for at least 4 hours; and e. cooling to room temperature.
Claim 2
Dependent Claim
154 words
A process for preparation of pyrophosphates selected from the group consisting of SiP 2 O 7 , ZrP 2 O 7 , Ba 2 P 2 O 7 , Pb 2 P 2 O 7 , Mg 2 P 2 O 7 , and Mn 2 P 2 O 7 which comprises: a. preparing a blend of an oxide selected from the group consisting of oxides of silicon, zirconium, barium, lead, magnesium and manganese with a stoichiometric excess of at least 40 percent of a source of P 2 O 5 ; b. placing said blend in a reaction vessel which is non-reactive with the materials in the blend; c. raising the temperature of said blend and reaction vessel to a reaction temperature at a rate of at least 200°C per hour; d. maintaining said blend and reaction vessel at said reaction temperature for at least 4 hours; and e. cooling to room temperature.
Claim 3
Dependent Claim
60 words
A process as set forth by claim 1, wherein said pyrophosphate to be prepared is selected from the group consisting of SiP 2 O 7 , ZrP 2 O 7 , Ba 2 P 2 O 7 , Mg 2 P 2 O 7 , Mn 2 P 2 O 7 , and Pb 2 P 2 O 7 .
Claim 4
Dependent Claim
14 words
A process as set forth by claim 2, wherein said oxide is silicic acid.
Claim 5
Dependent Claim
13 words
A process as set forth by claim 2, wherein said oxide is zirconia.
Claim 6
Dependent Claim
19 words
A process as set forth by claim 2 wherein said oxide comprises a blend of silicic acid and zirconia.
Claim 7
Dependent Claim
124 words
In the process for the synthesis of a pyrophosphate material selected from the group consisting of SiP 2 O 7 , ZrP 2 O 7 , Ba 2 P 2 O 7 , Pb 2 P 2 O 7 , Mg 2 P 2 O 7 and Mn 2 P 2 O 7 by the reaction of dihydrogen ammonium phosphate with a metallic oxide selected from the group consisting of oxides of silicon, zirconium, barium, lead, magnesium and manganese, the improvement which comprises providing a stoichiometric excess of at least 40 percent of the dihydrogen ammonium phosphate, and heating the reaction mass from room temperature to a temperature of from about 700°C to about 750°C at a rate of at least 200°C per hour.
Claim 8
Dependent Claim
124 words
In the process for the synthesis of a pyrophosphate material selected from the group consisting of SiP 2 O 7 , ZrP 2 O 7 , Ba 2 P 2 O 7 , Pb 2 P 2 O 7 , Mg 2 P 2 O 7 and Mn 2 P 2 O 7 by the reaction of dihydrogen ammonium phosphate with a metallic oxide selected from the group consisting of oxides of silicon, zirconium, barium, lead, magnesium and manganese, the improvement which comprises providing a stoichiometric excess of at least 40 percent of the dihydrogen ammonium phosphate, and heating the reaction mass from room temperature to a temperature of from about 700°C to about 750°C at a rate of at least 200°C per hour.
Claim 9
Dependent Claim
25 words
The improvement set forth by claim 6, wherein said pyrophosphate is SiP 2 O 7 and said oxide is SiO 2 .1/2 H 2 O.
Claim 10
Dependent Claim
22 words
The improvement set forth by claim 6, wherein said pyrophosphate is ZrP 2 O 7 and said oxide is ZrO 2 .
Claim 11
Dependent Claim
45 words
The improvement set forth by claim 6, wherein said pyrophosphate is a mixture of SiP 2 O 7 and ZrP 2 O 7 and said reaction mass comprises NH 4 H 2 PO 4 , SiO 2 .1/2 H 2 O, and ZrO 2 .
References Cited (Backward Citations)
US3849344A
Cited
US3852086A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |