Method for drying particulate polymers

Patent metadata

Field	Value
Publication number	US-9969849-B2
Application number	US-201515119857-A
Country	US
Kind code	B2
Filing date	Feb 16, 2015
Priority date	Feb 19, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present invention relates to a process for drying particulate polymers, comprising the steps of:
a) providing a particulate polymer comprising from 60 wt % to 90 wt % of at least one solvent based on the total weight of particulate polymer and solvent, b) mechanically predrying the particulate polymer to a content of the at least one solvent of from 20 wt % to 50 wt % based on the total weight of particulate polymer and solvent, wherein the mechanical predrying in step b) is carried out with a roller press, and c) end-drying the particulate polymer to a content of the at least one solvent of from 0 wt % to 15 wt % based on the total weight of particulate polymer and solvent, wherein the particulate polymer is a polymer comprising repeating units of formulae I, II and/or III

The present invention further relates to a process for working up particulate polymers.

First claim

The invention claimed is:

1. A process for drying particulate polymers, comprising:
a) mechanically pre-drying a particulate polymer comprising from 60 wt % to 90 wt % of a solvent (S 1 ) based on the total weight of particulate polymer and solvent (S 1 ),
to a content of the solvent (S 1 ) of from 20 wt % to 50 wt % based on the total weight of particulate polymer and solvent (S 1 ), wherein the mechanical pre-drying is carried out with a roller press, and
b) end-drying the particulate polymer to a content of the solvent (S 1 ) of from 0 wt % to 15 wt % based on the total weight of particulate polymer and solvent (S 1 ), wherein the particulate polymer is a polymer comprising repeating units of formulae I, II and/or III

2. The process according to claim 1 , wherein the end-drying is carried out with a fluidized bed dryer.

3. The process according to claim 1 , wherein the solvent (S 1 ) is water.

4. The process according to claim 1 , wherein the particulate polymer has an initial particle size of from 0.5 mm to 7 mm.

5. The process according to claim 1 , wherein the mechanically pre-dried particulate polymer is comminuted after the mechanical pre-drying and before the end-drying.

6. The process according to claim 1 , wherein the particulate polymer has a particle size of from 0.5 mm to 7 mm after the end-drying.

7. The process according to claim 1 , wherein the particulate polymer is a polyethersulfone.

8. A process for working up particulate polymers, comprising:
i) dropletizing a polymer solution comprising a polymer and a first organic solvent (S 2 ) into a precipitation bath comprising a second organic solvent (S 3 ) and water to obtain a particulate polymer by precipitation,
ii) removing the precipitated particulate polymer from the precipitation bath,
iii) extracting residues of the first and/or second organic solvent from the particulate polymer with an extractant,
iv) drying the particulate polymer with the process according to claim 1 and
v) optionally finishing the particulate polymer.

9. The process according to claim 8 , wherein the first and/or second organic solvent is N-methylpyrrolidone.

Assignees

• Basf Se

Inventors

• Erbes Joerg
• Lange Gerhard
• Kortekamp Tobias
• Linner Bernhard
• Schneider Cecile
• Ulzhoefer Angela
• Heinz Robert
• Mueller Michael Klemens

Classifications

• C08J3/12 Primary

  Powdering or granulating · CPC title

• C08J3/14 Primary

  by precipitation from solutions {(C08J3/122 takes precedence)} · CPC title

• F26B5/14

  by applying pressure, e.g. wringing; by brushing; by wiping · CPC title

• C08J2381/06

  Polysulfones; Polyethersulfones · CPC title

• F26B3/08

  so as to loosen them, e.g. to form a fluidised bed {("fluidised-bed" technique in general B01J8/24; centrifugal fluidised beds F26B7/007)} · CPC title