Patent US2065416A successfully refreshed from Google Patents.
Patent US4929406A successfully refreshed from Google Patents.
US4929406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing an inorganic porous membrane
Assignee: NGK Insulators Ltd
•
Filing: 1989-05-26
•
Granted: 1990-05-29
•
Expires: 2009-05-26
Abstract
Abstract A multilayer inorganic porous membrane consisting of a monolayer or multilayer porous support having at least one surface integrally formed thereon with a porous thin layer having an average pore size less than that of the porous support, wherein a maximum pore size in the support surface is defined to be from 1 to 250 times an average pore size of the thin layer. The multilayer porous membrane is superior in preventing the occurrence of pin holes and cracks therein thereby to enhancing precision of the filtration and separation.
Inventors
- 👤 Fumio Abe
- 👤 Hiroshi Mori
- 👤 Shigekazu Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:45
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0083; B01D67/0039; B01D67/0048; B01D67/0088; B01D71/00; B01D71/02; B01D71/024; C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5025; C04B41/5041; C04B41/80; C04B41/81; C04B41/85; C04B41/87; B01D2323/00; B01D2323/08; B01D2323/12; B01D2323/219; B01D2323/225; B01D2325/00; B01D2325/02; B01D2325/0283; C04B2111/00; C04B2111/00474; C04B2111/00793; C04B2111/00801
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
118 words
A process for the production of an inorganic porous membrane, comprising the steps of: providing a porous support; providing a hydrosol containing titanium hydroxide or titanium oxide, wherein a precursor forming the hydrosol is hydrolyzed under the presence of acid at a molar ratio of the precursor to water of more than 1/200 and a molar ratio of titanium compound contained in the hydrosol to water is diluted to less than 1/500; coating at least one surface of said porous support by immersion thereof in said hydrosol, so as to form a porous thin layer on said support; drying the hydrosol coated porous support; and firing the hydrosol coated porous support at a temperature of about 300°-700° C.
Claim 2
Dependent Claim
118 words
A process for the production of an inorganic porous membrane, comprising the steps of: providing a porous support; providing a hydrosol containing titanium hydroxide or titanium oxide, wherein a precursor forming the hydrosol is hydrolyzed under the presence of acid at a molar ratio of the precursor to water of more than 1/200 and a molar ratio of titanium compound contained in the hydrosol to water is diluted to less than 1/500; coating at least one surface of said porous support by immersion thereof in said hydrosol, so as to form a porous thin layer on said support; drying the hydrosol coated porous support; and firing the hydrosol coated porous support at a temperature of about 300°-700° C.
Claim 3
Dependent Claim
20 words
The process of claim 1, wherein said hydrosol coated porous support is fired at a temperature of about 400°-700° C.
Claim 4
Dependent Claim
35 words
The process of claim 1, wherein the molar ratio of the precursor to water is about 1/200-1/40 and the molar ratio of titanium compound contained in the hydrosol to water is diluted to about 1/800-1/2000.
References Cited (Backward Citations)
JPS5294572A
Cited
FR2473313A1
Cited
FR2502508A1
Cited
FR2549736A1
Cited
JPS60156510A
Cited
JPS61500221A
Cited
JPS6127091A
Cited
EP0188950A1
Cited
FR2580517A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |