US2657154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of acidproofing the surface of porous calcareous articles
Assignee: Individual
•
Filing: 1951-05-15
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Granted: 1953-10-27
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Expires: 1971-05-15
Abstract
No abstract record available.
Inventors
- 👤 Brouwer Cornelis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:49
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5018; C04B41/5019; C04B41/60; C04B41/61; C04B41/65; C04B41/66
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
A PROCESS OF ACID PROFING THE SURFACE OF POROUS CALCAREOUS ARTICLES OF CONCRETE AND THE LIKE SUBJECT TO ATTACK BY ACIDS AND CONTAINING CALCIUM COMPOUNDS CAPABLE OF REACTING WITH SILICON TETRAFLUORIDE WHICH COMPRISES CONTACTING THE DRY SURFACE OF SUCH AN ARTICLE WITH GASEOUS SILICON TETRAFLUORIDE FOR A TIME SUFFICIENT TO CAUSE THE SILICON TETRAFLUORIDE TO PENETRATE AND REACT WITHIN THE PORES THEREOF, THE SAID DRY SURFACE BEING PREVIOUSLY DRIED AT LEAST TO THE AIR-DRY STATE.
Claim 2
Dependent Claim
75 words
A PROCESS OF ACID PROFING THE SURFACE OF POROUS CALCAREOUS ARTICLES OF CONCRETE AND THE LIKE SUBJECT TO ATTACK BY ACIDS AND CONTAINING CALCIUM COMPOUNDS CAPABLE OF REACTING WITH SILICON TETRAFLUORIDE WHICH COMPRISES CONTACTING THE DRY SURFACE OF SUCH AN ARTICLE WITH GASEOUS SILICON TETRAFLUORIDE FOR A TIME SUFFICIENT TO CAUSE THE SILICON TETRAFLUORIDE TO PENETRATE AND REACT WITHIN THE PORES THEREOF, THE SAID DRY SURFACE BEING PREVIOUSLY DRIED AT LEAST TO THE AIR-DRY STATE.
References Cited (Backward Citations)
GB260031A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-10-26 | 1957-04-27 | 1957-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-26 | 1961-04-27 | 1961-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-26 | 1965-04-27 | 1965-10-27 | $7700.00 | Window Closed / Lapsed |