Patent US4668706A successfully refreshed from Google Patents.
US4668706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Substituted aliphatic polyamide porous membranes
Assignee: Memtec Ltd
•
Filing: 1986-07-18
•
Granted: 1987-05-26
•
Expires: 2006-07-18
Abstract
Abstract Aliphatic thermoplastic polyamide porous membranes are reacted with an acid halide of basicity above one to provide acid radicals within the membrane. The acid halide may be derived from an aromatic carboxylic acid or an aromatic derivative of a chlorosilane. The substituted aliphatic polyamide porous membrane lend themselves to the preparation of chemical derivatives of the membrane which are not readily available by aqueous synthesis and to increased density of derivatives which otherwise may be prepared by water.
Inventors
- 👤 Douglas L. Ford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:59
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D15/00; B01D15/08; B01D71/00; B01D71/06; B01D71/56; C; C08; C08J; C08J9/00; C08J9/28; B01D2323/00; B01D2323/30; C08J2377/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A polymeric porous membrane comprising a membrane matrix made from an aliphatic polyamide material which has both relatively non-crystalline and relatively crystalline portions joined together by relatively non-crystalline portions wherein at least some of the relatively non-crystalline portions of the membrane have the following type of structure: ##STR4## where X is the acid radical of an acid halide of basicity above one or a derivative of said acid halide.
Claim 2
Dependent Claim
69 words
A polymeric porous membrane comprising a membrane matrix made from an aliphatic polyamide material which has both relatively non-crystalline and relatively crystalline portions joined together by relatively non-crystalline portions wherein at least some of the relatively non-crystalline portions of the membrane have the following type of structure: ##STR4## where X is the acid radical of an acid halide of basicity above one or a derivative of said acid halide.
Claim 3
Dependent Claim
56 words
A membrane according to claim 1 wherein the free end of the terminal acid halide chain has been reacted with a phenol of basicity above one so that the free end of the acid halide becomes a phenol ester as follows: ##STR5## where R is a substituent consisting of or containing at least one phenolic group.
Claim 4
Dependent Claim
11 words
A membrane according to claim 2 wherein the phenol is resorcinol.
Claim 5
Dependent Claim
16 words
A membrane according to claim 2 wherein the membrane is cross-linked by reaction with an aldehyde.
Claim 6
Dependent Claim
11 words
A membrane according to claim 4, wherein the aldehyde is glutaraldehyde.
Claim 7
Dependent Claim
17 words
A membrane according to claim 5, modified in that formaldehyde is used as an additional linking reagent.
Claim 8
Dependent Claim
17 words
A membrane as claimed in claim 2 where the acid halide is an organic or metal-organic halide.
Claim 9
Dependent Claim
24 words
A membrane according to claim 7 wherein the acid halide is derived from an aromatic carboxylic acid or an aromtic derivative of a chlorosilane.
Claim 10
Dependent Claim
15 words
A membrane according to claim 7 wherein the acid halide is either terephthaloylchloride, or isophthaloylchloride.
Claim 11
Dependent Claim
23 words
A membrane according to claim 7 wherein the acid halide is the reaction product of an excess of a dichlorosilane with a diphenol.
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) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |