US3926865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for polymerizing lactams in the presence of azodicarboxylate and isocyanate
Assignee: Imperial Chemical Industries Ltd
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Filing: 1974-08-27
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Granted: 1975-12-16
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Expires: 1994-08-27
Abstract
Abstract This invention relates to a process for the manufacture of polyamides and polyamide foams, particularly the production of foams in a polymerizing lactam mixture comprising forming a mixture of (1) a lactam having at least seven ring members which is associated with 0.01 to 0.5% by weight of water, (2) an alkali metal salt of azodicarboxylic acid, wherein the metal salt of azodicarboxylic acid is present in an amount at least equimolar with the amount of water present, and polymerizing said lactam under anionic polymerization conditions, whereby said metal salt of azodicarboxylic acid enables polymerization to take place even though said lactam is initially associated with a considerable amount of water.
Inventors
- 👤 Norman Stewart Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:44
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/16; C08G69/18; C08G69/20; C08J2377/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
120 words
A PROCESS FOR THE MANUFACTURE OF A POLYAMIDE COMPRISING FORMING A MIXTURE OF (1) A LACTAM HAVING AT LEAST SEVEN RING MEMBERS WHICH IS ASSOCIATED WITH 0.01 TO 0.5 PERCENT BY WEIGHT OF WATER, (2) AND ALKALI METAL SALT OF AZOIDICARBOXYLIC ACID, WHEREIN THE METAL SALT OF AZODICABROXYLIC ACID IS PRESENT IN AN AMOUNT AT LEAST EQUIMOLAR WITH THE AMOUNT OF WATER PRESENT, AND (3) AN ISOCYANATE OR BLOCKED ISOCYANATE WHICH, TOGETHER WITH A PORTION OF SAID ALKALI METAL SALT OF AZODICARBOXYLIC ACID, CONSTITUTES A CATALYST SPECIES, AND POLYMERIZING SAID LACTAM UNDER ANONIC POLYMERIZATION CONDITIONS, WHEREBY SAID METAL SALT OF AZODICARBOXYLIC ACID ENABLES POLYMERIZATION TO TAKE PLACE EVEN THOUGH SAID LACTAM IS INITIALLY ASSOCIATED WITH A CONSIDERABLE AMOUNT OF WATER.
Claim 2
Dependent Claim
120 words
A PROCESS FOR THE MANUFACTURE OF A POLYAMIDE COMPRISING FORMING A MIXTURE OF (1) A LACTAM HAVING AT LEAST SEVEN RING MEMBERS WHICH IS ASSOCIATED WITH 0.01 TO 0.5 PERCENT BY WEIGHT OF WATER, (2) AND ALKALI METAL SALT OF AZOIDICARBOXYLIC ACID, WHEREIN THE METAL SALT OF AZODICABROXYLIC ACID IS PRESENT IN AN AMOUNT AT LEAST EQUIMOLAR WITH THE AMOUNT OF WATER PRESENT, AND (3) AN ISOCYANATE OR BLOCKED ISOCYANATE WHICH, TOGETHER WITH A PORTION OF SAID ALKALI METAL SALT OF AZODICARBOXYLIC ACID, CONSTITUTES A CATALYST SPECIES, AND POLYMERIZING SAID LACTAM UNDER ANONIC POLYMERIZATION CONDITIONS, WHEREBY SAID METAL SALT OF AZODICARBOXYLIC ACID ENABLES POLYMERIZATION TO TAKE PLACE EVEN THOUGH SAID LACTAM IS INITIALLY ASSOCIATED WITH A CONSIDERABLE AMOUNT OF WATER.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the salt is sodium or potassium azodicarboxylate.
Claim 4
Dependent Claim
26 words
A process according to claim 1 wherein the isocyanate is selected from the group comprising dodecyl isocyanate, phenyl isocyanate, hexamethylene diisocyanate, tolylene diisocyanate and dipenhylmethane diisocyanate.
Claim 5
Dependent Claim
12 words
A process according to claim 1 wherein the blocked isocyanate is hexamethylene-bis-carbamidocaprolactam.
Claim 6
Dependent Claim
23 words
A process according to claim 1 wherein the molar ratio of isocyanate or blocked isocyanate to azodicarboxylic acid salt is 0.1:1 to 10:1.
Claim 7
Dependent Claim
13 words
A process according to claim 5 wherein the ratio is 0.2:1 to 5:1.
Claim 8
Dependent Claim
12 words
A process according to claim 1 wherein the lactam is epsilon -caprolactam.
Claim 9
Dependent Claim
40 words
A process as set forth in claim 1 in which the amount of said salt of azodicarboxylic acid exceeds the amount of water on a molar basis and including thermally decomposing a portion of said salt to foam said polyamide.
Claim 10
Dependent Claim
16 words
A process according to claim 8 wherein the polymerization and foaming are effected in a mold.
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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |