Polycarbonate production with motionless mixer

• US 4,847,352 A
• Filed: 08/26/1987
• Issued: 07/11/1989
• Est. Priority Date: 08/26/1987
• Status: Expired due to Term

• Current Assignee: Diamond Technology Partnership Company
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Weston, John W., Smith, Ronald R. II, Aguilar, Jose L.
• Primary Examiner(s): Anderson, Harold D.
• Application Number:
  US07/089,658
• Time in Patent Office: 685 Days
• Field of Search: 528/196, 528/198, 528/199, 525/462
• US Class Current: 528/196
• CPC Class Codes: C08G 64/24 and phenols

Abstract

Polycarbonate prepolymers are produced by adding phosgene, one or more dihydric phenols, a halogenated organic solvent, and an aqueous caustic solution together with mixing in motionless mixers to form fine dispersions of partially phosgenated phenols, allowing for interfacial reactions to occur in residence time sections and repeating the steps after the addition of caustic to form high molecular weight prepolymers. These prepolymers are then polymerized with amines to form high molecular weight polycarbonates.

Claims

1. A process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing one or more dihydric phenols, an aqueous caustic solution, a halogenated organic solvent and phosgene by means of at least one motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said phenols in said aqueous solution,

(B) allowing said dispersion to react in a residence time section with a residence time in the range from about 5 to about 75 seconds into a coarse dispersion containing said partially phosgenated derivatives of said phenols,

(C) repeating the mixing and reacting steps of A and B one or more times until said phenols are completely phosgenated,

(D) mixing additional aqueous caustic solution with said dispersion,

(E) repeating the mixing and reacting steps of A and B whereby a dispersion of a polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(F) simultaneously cooling said dispersion to a temperature in the range from about 25°

to about 45°

C. and mixing a tertiary amine catalyst with said dispersion to form said polycarbonate resin, and

(G) recovering said polycarbonate resin.

2. A process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing bisphenol A, an aqueous caustic solution, methylene chloride and phosgene by means of at least one motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said bisphenol A in said aqueous solution,

(B) allowing said dispersion to react in a residence time section with a residence time in the range from about 20 to about 40 seconds into a coarse dispersion containing said partially phosgenated derivatives of said bisphenol A,

(C) repeating the mixing and reacting steps of A and B one or more times until said bisphenol A is completely phosgenated,

(D) mixing additional aqueous caustic solution with said dispersion,

(E) repeating the mixing and reacting steps of A and B whereby a dispersion of a bisphenol A polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained, and

(F) simultaneously cooling said dispersion to a temperature in the range from about 25°

to about 45°

C. and mixing a tertiarylamine catalyst with said dispersion to form said polycarbonate resin, and

(G) recovering said polycarbonate resin.

3. A process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing one or more dihydric phenols, an aqueous caustic solution, a halogenated organic solvent and phosgene by means of a motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said phenols in said aqueous solution,

(B) reacting said dispersion in a residence time section with a residence time in the range from about 5 to about 75 seconds into a coarse dispersion containing said partially phosgenated derivatives of said phenols,

(C) mixing said coarse dispersion containing said partially phosgenated derivatives of said phenols in a second motionless mixer to form a second fine dispersion,

(D) reacting said dispersion in a second residence time section into a coarse dispersion containing said phosgenated derivatives of said phenols,

(E) mixing additional aqueous caustic solution with said dispersion,

(F) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C.,

(G) repeating the mixing and reacting steps of A-D until a dispersion of a polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(H) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C. and mixing a tertiary amine catalyst with said dispersion to form said polycarbonate resin, and

(I) recovering said polycarbonate resin.

4. A process for the production of high weight average molecular weight polycarbonate resin which consists essentially of the steps of

(A) mixing bisphenol A, an aqueous caustic solution, a chlorinated organic solvent and phosgene by means of a motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said bisphenol in said aqueous solution,

(B) reacting said dispersion in a residence time section with a residence time in the range from about 20 to about 40 seconds into a coarse dispersion containing said partially phosgenated derivatives of said bisphenol,

(C) mixing said coarse dispersion containing said partially phosgenated derivatives of said phenol in a second motionless mixer to form a second fine dispersion,

(D) reacting said dispersion in a second residence time section into a coarse dispersion containing said phosgenated derivatives of said bisphenol,

(E) mixing additional aqueous caustic solution with said dispersion,

(F) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C., and

(G) repeating the mixing and reaction steps of A-D until a dispersion of a polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(H) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C. and mixing a tertiary amine catalyst with said dispersion to form said polycarbonate resin, and

(I) recovering said polycarbonate resin.

5. An interfacial process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing one or more dihydric phenols, an aqueous caustic solution, a halogenated organic solvent and phosgene by means of at least one motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said phenols in said aqueous solution,

(B) reacting said dispersion in a residence time section with a residence time in the range from about 5 to about 75 seconds into a coarse dispersion containing said partially phosgenated derivatives of said phenols,

(C) repeating the mixing and reacting steps of A and B one or more times until said phenols are completely phosgenated,

(D) mixing additional aqueous caustic solution with said dispersion,

(E) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C.,

(F) repeating the mixing and reacting steps of A and B whereby a dispersion of a polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(G) mixing a tertiary amine catalyst with said dispersion to form said polycarbonate resin, and

(H) recovering said polycarbonate resin.

6. An interfacial process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing bisphenol A, an aqueous caustic solution, methylene chloride and phosgene by means of at least one motionless mixer to form a fine dispersion of the partially phosgenated derivatives of bisphenol A in said aqueous solution,

(B) allowing said dispersion to react in a residence time section with a residence time in the range from about 20 to about 40 seconds into a coarse dispersion containing said partially phosgenated derivatives of bisphenol A,

(C) repeating the mixing and reacting steps of A and B one or more times until said bisphenol A is completely phosgenated,

(D) mixing additional aqueous caustic solution with said dispersion,

(E) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C.,

(F) repeating the mixing and reacting steps of A and B whereby a dispersion of bisphenol A prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(G) mixing a trialkylamine with said dispersion to form said polycarbonate resin, and

(H) recovering said polycarbonate resin.

7. An interfacial process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing one or more dihydric phenols, an aqueous caustic solution, a halogenated organic solvent and phosgene by means of a motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said phenols in said aqueous solution,

(B) reacting said dispersion in a residence time section with a residence time in the range from about 5 to about 75 seconds into a coarse dispersion containing said partially phosgenated derivatives of said phenols,

(C) mixing said coarse dispersion containing said partially phosgenated derivatives of said phenols in a second motionless mixer to form a second fine dispersion,

(D) reacting said dispersion in a second residence time section into a coarse dispersion containing said phosgenated derivatives of said phenols,

(E) mixing additional aqueous caustic solution with said dispersion,

(F) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C.,

(G) repeating the mixing and reacting steps of A-D until a dispersion of a polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(H) mixing a tertiary amine catalyst with said dispersion to form said polycarbonate resin, and

(I) recovering said polycarbonate resin.

8. A interfacial process for the production of high weight average molecular weight polycarbonate resins which consists essentially of the steps of

(A) mixing bisphenol A, an aqueous caustic solution, a chlorinated organic solvent and phosgene by means of a motionless mixer to form a fine dispersion of the partially phosgenated derivatives of said bisphenol in said aqueous solution,

(B) reacting said dispersion in a residence time section with a residence time in the range from about 5 to about 75 seconds into a coarse dispersion containing said partially phosgenated derivatives of said bisphenol,

(C) mixing said coarse dispersion containing said partially phosgenated derivatives of said phenol in a second motionless mixer to form a second fine dispersion,

(D) reacting said dispersion in a second residence time section into a coarse dispersion containing said phosgenated derivatives of said bisphenol,

(E) mixing additional aqueous caustic solution with said dispersion,

(F) cooling said dispersion to a temperature in the range from about 25°

to about 45°

C.,

(G) repeating the mixing and reacting steps of A-D until a dispersion of a polycarbonate prepolymer having a weight average molecular weight range of about 4000 to about 12000 is obtained,

(H) mixing a trialkylamine with said dispersion to form said polycarbonate resin, and

(I) recovering said polycarbonate resin.