Abstract:
1,257,967. Solid state polymerisation. SNIA VISCOSA SOC: NAZIONALE INDUSTRIA APPLICAZIONI VISCOSA S.p.A. 4 Feb., 1969 [26 March, 1968], No. 5907/69. Heading B1X. [Also in Divisions C3 and F4] Crystallised polyester pellets are simultaneously dried and solid-state polymerised by passing them continuously through a vessel 47 in countercurrent to a heated inert gas. Polyester which has been either pelletised and crystallised in a fluidised bed enters at the top of vessel 47 and falls as a bed under gravity, the pellets being removed at the base of the vessel by discharge rotary valve 58. The inert gas is first heated to a temperature of from 160 to 212‹C in heater 43 and then enters vessel 47 via plenum chamber 46, leaving via chamber 51. The gas velocity is kept below fluidization rates (below 2.1 ft/sec.). A level controller 50 is provided for controlling the residence time of the polymer in the vessel. The vessel should preferably have a height of at least six times its diameter and a cross-sectional area of at least twice that of the fluidised crystalliser used in the preceding step. Specified dimensions for the vessel are given in Examples 7-10.
Abstract:
The esterification of a polycarboxylic acid with a polyol is described under conditions of direct esterification and wherein the reacting mass is a flowable, uniform dispersion of (1) a paste of the said polycarboxylic acid and the said polyol, and (2) at least 3 parts by weight per part paste of a partially esterified product of said polycarboxylic acid with said polyol.
Abstract:
A HIGH MOLEUCULAR WEIGHT LINEAR CONDENSATION POLYESTER IS PREPARED FROM A POLYCARBOXYLIC ACID AND A POLYOL BY (A) ESTERIFYING SAID POLYCARBOXYLIC ACID WITH SAID POLYOL BY SUBJECTING TO CONDITIONS OF DIRECT ESTERIFICATION A FLOWABLE, UNIFORM DISPERSION COMPRISED OF (1) A PASTE OF THE SAID POLYCARBOXYLIC ACID AND THE SAID POLYOL, AND (2) AT LEAST 3 PARTS BY WEIGHT PER PART PASTE OF A PARTIALLY ESTERIFIED PRODUCT OF SAID POLYCARBOXYLIC ACID WITH SAID POLYOL, AND THENCE (B) FURTHER ESTERIFYING AND POLYCONDENSING THE ESTERIFICATION PRODUCT OF STEP (A) UNTIL THERE IS OBTAINED AN IMPROVED POLYESTER OF THE DESIRED MOLECULAR WEIGHT.
Abstract:
APPARATUS FOR CONTINUOUS ESTERIFICATION AND POLYCONDENSATION COMPRISING A RECTIFICATION UNIT HAVING A FEED OUTLET THEREFROM TO A MULTIPLE ZONE SUBSTANTIAL VERTICAL ESTERIFICATION MEANS CONTAINING AGITATORS AND WEIRS (WHEREIN SAID AGITATORS ARE CONICAL IN SHAPE) AND INTERPOSITIONED WITH RESPECT TO SAID WEIRS, AND DEVOLATILIZATION MEANS LOCATED BETWEEN SAID MULTIPLE ZONE ESTERIFICATION MEANS AND A PLUG FLOW MEANS.
Abstract:
THE ESTERIFICATION OF POLYCARBOXYLIC ACID WITH AN ALKYLENE GLYCOL IS DESCRIBED UNDER CONDITIONS OF DIRECT ESTERIFICATION WHEREIN THE POLYCARBOXYLIC ACID IS ESTERIFIED WITH AN ALKYLENE GLYCOL IN THE PRESENCE OF AMMONIA OR AN AMMONIUM SALT OF A DIBASIC CARBOXYLIC ACID.