US3782075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Completely porous microspheres for chromatographic uses
Assignee: EIDP Inc
•
Filing: 1972-04-07
•
Granted: 1974-01-01
•
Expires: 1992-04-07
Abstract
Abstract This invention relates to an improved packing material for chromatographic columns, prepared from a powder of uniform-sized porous microspheres composed of a plurality of interconnected colloidal oxide particles.
Inventors
- 👤 J Kirkland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:56
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/281; B01J20/282; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J2/00; B01J2/02; B01J2/06; B01J2/08; B01J20/02; B01J20/06; B01J20/283; B01J20/284; G; G01; G01N; G01N30/00; G01N30/02; G01N30/50; G01N30/52; B01J2220/00; B01J2220/50; B01J2220/54
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
20 words
The apparatus of claim 1 in which said microspheres have an average diameter of about 1.0 to about 10 microns.
Claim 2
Dependent Claim
32 words
The apparatus of claim 2 in which substantially all of said microspheres have a diameter ranging from about 0.8 to about 1.2 times the average diameter of the microspheres in said powder.
Claim 3
Dependent Claim
33 words
The apparatus of claim 2 in which said colloidal particles are composed of materials selected from the group consisting of silica, alumina, zirconia, titania, ferric oxide, antimony oxide, tin oxide and combinations thereof.
Claim 4
Dependent Claim
14 words
The apparatus of claim 2 in which said colloidal particles are composed of silica.
Claim 5
Dependent Claim
20 words
The apparatus of claim 2 in which said colloidal particles occupy less than 50% of the volume of said microspheres.
Claim 6
Dependent Claim
31 words
The apparatus of claim 6 in which said microspheres have a specific surface area greater than about 75% of the surface area of the colloidal particles from which they are made.
Claim 7
Dependent Claim
16 words
The apparatus of claim 2 in which said micRospheres are modified with a sorptively active material.
Claim 8
Dependent Claim
122 words
In a process for performing chromatographic separation comprising contacting the materials to be separated in a carrier phase with a resolving zone, the improvement wherein said resolving zone comprises a plurality of uniform-sized porous microspheres having an average diameter of about 0.5 to about 20 microns, substantially all of said microspheres having a diameter ranging from about 0.5 to about 1.5 times the average diameter of the microspheres in said powder; said microspheres consisting essentially of a plurality of uniform-sized colloidal particles, having a refractory metal oxide surface, arranged in a interconnected three-dimensional lattice, said colloidal particles occupying less than 50% of the volume of said microspheres with the remaining volume being occupied by interconnected pores having a uniform pore size distribution.
Claim 9
Dependent Claim
20 words
The process of claim 9 in which said microspheres have an average diameter of about 1.0 to about 10 microns.
Claim 10
Dependent Claim
32 words
The process of claim 10 in which substantially all of said microspheres have a diameter ranging from about 0.8 to about 1.2 times the average diameter of the microspheres in said powder.
Claim 11
Dependent Claim
32 words
The process of claim 10 wherein said colloidal particles are composed of materials selected from the group consisting of silica, alumina, zirconia, titania, ferric oxide, antimony oxide, tin oxide and combinations thereof.
Claim 12
Dependent Claim
13 words
The process of claim 10 wherein said colloidal particles are composed of silica.
Claim 13
Dependent Claim
19 words
The process of claim 10 wherein said colloidal particles occupy less than 50% of the volume of said microspheres.
Claim 14
Dependent Claim
30 words
The process of claim 14 wherein said microspheres have a specific surface area greater than about 75% of the surface area of the colloidal particles from which they are made.
Claim 15
Dependent Claim
15 words
The process of claim 10 wherein said microspheres are modified with a sorptively active material.
References Cited (Backward Citations)
US3535265A
Cited
US3505785A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |