Patent US3773738A successfully refreshed from Google Patents.
← Back to Patent Explorer
US3773738A Expired / Lapsed US ⏱️ 0.0 years remaining

Polycarbonamide preparation with diffusion of volatile by-products

Assignee: Imperial Chemical Industries Ltd
•
Filing: 1971-12-10
•
Granted: 1973-11-20
•
Expires: 1991-12-10
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A PROCESS FOR THE PREPARATION OF HIGH MOLECULAR WEIGHT POLYMER BY CONDENSATION PROCESS OF A LIQUID REACTION MIXTURE WHEREIN AT LEAST ONE VOLATILE BY-PRODUCT IS ELIMINATED, CHARACTERIZED IN THAT SAID CONDENSATION PROCESS IS CARRIED OUT IN APPARATUS OF SUCH FORM AND SO OPERATED THAT SAID REACTION MIXTURE BEING SUBJECTED TO THE CONDENSATION PROCESS HAS NO FREE SURFACE AND REMOVAL OF VOLATILE PRODUCT OR PRODUCTS FROM SAID REACTION MIXTURE IS EFFECTED BY DIFFUSION THROUGH AT LEAST A PROPORTION OF THE WALL OF SAID APPARATUS WHICH IS PERMEABLE TO SAID VOLATILE PRODUCT OR PRODUCTS BUT NOT PERMEABLE TO SAID REACTION MIXTURE OR SAID POLYMER, SAID PROPORTION OF THE WALL WHICH IS PERMEABLE SERVING TO SEPARATE SAID REACTION MIXTURE FROM A CHEMICALLY INERT GASEOUS FLUID IN WHICH THE PARTIAL PRESSURE OF THE VOLATILE BY-PRODUCT, OR OF THE VOLATILE BY-PRODUCTS, IS CONTINUALLY MAINTAINED BELOW THE EQUILIBRIUM PARTIAL PRESSURE FOR THE REACTION MIXTURE UNDER THE CONDITIONS OF REACTION.

Inventors

  • 👤 K Porter
  • 👤 B Richardson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 19:04
CPC Classifications
B; B01; B01D; B01D19/00; B01D19/0031; B01J; B01J4/00; B01J4/04; C; C08; C08G; C08G63/00; C08G63/78; C08G63/785

Claims Analysis

Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-11-19 1977-05-21 1977-11-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-11-19 1981-05-21 1981-11-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-11-19 1985-05-21 1985-11-20 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag