US 2003/0111186 A1 · Method for isolating polyphenylene ether polymer resins from solution

Abstract

A method of removing substantially all solvent from a solution containing a polyphenylene ether polymer resin with little by-product formation (less than 250 ppm) is provided. The method employs a wiped thin film evaporator with a cylindrical heating chamber operating under conditions that satisfy the relationships defined by Equations I and II. 5.3*1024RLδ exp(−24123/T)/m<C I 100−(4960AP/Tm)<C II; Yields are maximized wherein values for feed rate (m) and percent solids (C) are selected to provide a maximum value for the output, Q, determined from the equation m * C=Q and the melt viscosity of the polyphenylene ether product is less than 50,000 centipoise at the operating temperature of the cylindrical heating chamber.

Claims16

Dependent claims

A method for removing solvent from a solution of a polyphenylene ether polymer resin in a thin film evaporator said method comprising:

a) feeding a solution comprising at least one organic solvent and a polyphenylene ether polymer resin into a thin film evaporator having a heating chamber,
b) forming a film of said solution on the wall of said heating chamber and
c) heating said film in the heating chamber of said thin film evaporator operating under conditions for pressure, temperature, feed rate and solution solids concentration which satisfy two rate models, one model defines a rate of by-product formation of less than 250 ppm, the other model defines the vapor velocity of the material exiting the thin film evaporator of less than 1.5 ft/s.

A method for removing solvent from a solution of a polyphenylene ether polymer resin in a wiped thin film evaporator said method comprising:

a) feeding a solution comprising at least one organic solvent and a polyphenylene ether polymer resin into a wiped thin film evaporator having a cylindrical heating chamber,
b) forming a film of said solution on the wall of said cylindrical heating chamber and
c) heating said film on the wall of said cylindrical heating chamber of said wiped thin film evaporator operating under conditions for pressure, temperature, feed rate and solution solids concentration which satisfy the relationships defined by Equations I and II:
5.3*1024RLδ exp(−24123/T)/m<C I 100−(4960AP/Tm)<C II;
wherein
T is the operating temperature of the cylindrical heating chamber within the wiped thin film evaporator in absolute temperature (K);
R is the radius of the cylindrical heating chamber within the wiped thin film evaporator in ft;
L is the length of the cylindrical heating chamber within the wiped thin film evaporator in ft;
P is the operating pressure of the cylindrical heating chamber within the wiped thin film evaporator in absolute pressure (mmHg);
A is the cross-sectional area of the cylindrical heating chamber within the wiped thin film evaporator in ft2;
δ is the thickness of the film of said solution on the wall of said cylindrical heating chamber in ft;
m is the feed rate of said solution of polyphenylene ether polymer resin into the cylindrical heating chamber within the wiped thin film evaporator in lb of solution/hr;
and
C is the solids concentration of said solution of polyphenylene ether polymer resin in wt % solids.

11 more elements

Dependencies are inferred from the claim text.

Method for isolating polyphenylene ether polymer resins from solution

Life of this patent

Method for isolating polyphenylene ether polymer resins from solution

Life of this patent

Abstract

Claims16