US3904422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous glass support material
Assignee: Corning Glass Works
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Filing: 1973-03-30
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Granted: 1975-09-09
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Expires: 1993-03-30
Abstract
Abstract Porous glass support materials having two essentially distinct zones of porosity. An outer surface zone comprises an outer shell with relatively large pores of controlled diameter while an inner zone comprises a core portion having relatively smaller pores of controlled diameter. The materials are made by subjecting porous glass bodies of substantially uniform pore size to a carefully controlled alkali etching cycle in which only the outer zone of the bodies have their pores enlarged. The thus treated bodies are particularly useful as chromatographic support materials which, in use, demonstrate a desirably low height equivalent theoretical plate (HETP).
Inventors
- 👤 David L Eaton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:23
CPC Classifications
C; C03; C03C; C03C11/00; C03C11/005; B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/28; B01J20/28054; B01J20/28078; B01J20/28088; B01J20/28092; B01J20/281; B01J20/282; B01J20/283; C03C15/00; B01J2220/00; B01J2220/50; B01J2220/54
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
90 words
IN A POROUS GLASS BODY COMPRISING A GLASS HAVING A NETWORK OF INTERCONNECTED VOIDS AND CHANNELS OF SUBSTANTIALLY UNIFORM AVERAGE PORE DIAMETER, THE IMPROEMENT WHICH COMPRISES HAVING TWO ESSENTIALLY DISTINCT ZONES OF POROSITY, SAID TWO ZONES OF POROSITY COMPRISING AN INNER CORE PORTION HAVING PORES OF SUBSTANTIALLY UNIFORM AVERAGE PORE DIAMETER, AND AN OUTER LAYER HAVING PORES OF SUBSTANTIALLY UNIFORM AVERAGE PORE DIAMETER, THE AVERAGE PORE DIAMETER OF SAID OUTER LAYER BEING BETWEEN 100A AND 2,500A AND THE AVEAGE PORE DIAMETER OF THE CORE PORTION BEING BETWEEN 20A AND 60A.
Claim 2
Dependent Claim
90 words
IN A POROUS GLASS BODY COMPRISING A GLASS HAVING A NETWORK OF INTERCONNECTED VOIDS AND CHANNELS OF SUBSTANTIALLY UNIFORM AVERAGE PORE DIAMETER, THE IMPROEMENT WHICH COMPRISES HAVING TWO ESSENTIALLY DISTINCT ZONES OF POROSITY, SAID TWO ZONES OF POROSITY COMPRISING AN INNER CORE PORTION HAVING PORES OF SUBSTANTIALLY UNIFORM AVERAGE PORE DIAMETER, AND AN OUTER LAYER HAVING PORES OF SUBSTANTIALLY UNIFORM AVERAGE PORE DIAMETER, THE AVERAGE PORE DIAMETER OF SAID OUTER LAYER BEING BETWEEN 100A AND 2,500A AND THE AVEAGE PORE DIAMETER OF THE CORE PORTION BEING BETWEEN 20A AND 60A.
Claim 3
Dependent Claim
16 words
The glass body, as claimed in claim 1, wherein the glass is an alkali borosilicate glass.
Claim 4
Dependent Claim
18 words
The glass body, as claimed in claim 2, wherein the alkali borosilicate glass is a sodium borosilicate glass.
Claim 5
Dependent Claim
24 words
The glass body, as claimed in claim 3, wherein the glass consists of about 6.0 percent Na2O, 25.6 percent B2O3, and 68.4 percent SiO2.
Claim 6
Dependent Claim
15 words
The glass body, as claimed in claim 4, wherein the body is in bead form.
Claim 7
Dependent Claim
15 words
The glass body, as claimed iN claim 4, wherein the body is in particulate form.
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) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |