Production of high temperature polymer based pellets by underwater pelletization at elevated water temperature to produce (rigid) bead foams

Patent metadata

Field	Value
Publication number	US-12496753-B2
Application number	US-202118041771-A
Country	US
Kind code	B2
Filing date	Jul 15, 2021
Priority date	Aug 18, 2020
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A process can be used for producing (rigid) particle foams from polymer compositions containing at least one polymer having a glass transition temperature according to ISO 11357-2 of at least 180° C. with an underwater pelletization system.

First claim

The invention claimed is:

1 . A process for preparing expandable pellets with an underwater pelletization system from a polymer composition comprising at least one polymer having a glass transition temperature according to ISO 11357-2 published: 2014-07 of at least 180° C., the process comprising:
a) conveying a polymer melt of the polymer composition from an extruder into a first water circuit that is pressurized, with a gauge pressure being within a range from 0.2 to 30 bar and a water temperature in the first water circuit being within a range from 105° C. to 180° C., and
b) pelletizing,
wherein the polymer composition comprises a blowing agent,
further comprising:
c) supplying a pelletized material from b) to a second water circuit that has a temperature below 100° C. and is operated
1) unpressurized, or
2) under a gauge pressure within a range from 0.2 to 30 bar.

2 . The process for preparing expandable pellets according to claim 1 , wherein the at least one polymer having a glass transition temperature according to ISO 11357-2 of at least 180° C. is selected from the group consisting of a polysulfone, a polyimide, and a mixture thereof.

3 . The process for preparing expandable pellets according to claim 2 , wherein the at least one polymer having a glass transition temperature according to ISO 11357-2 of at least 180° C. is selected from the group consisting of polyethersulfone (PESU), polyphenylsulfone (PPSU), polysulfone (PSU), polyetherimide (PEI), a thermoplastic polyimide, and a mixture thereof.

4 . The process for preparing expandable pellets according to claim 1 , wherein the temperature in a) is at least 5° C. below a Tg of the polymer melt containing the blowing agent and said at least one polymer.

5 . The process for preparing expandable pellets according to claim 1 , wherein the blowing agent is selected from the group consisting of a volatile organic compound having a boiling point at standard pressure below a glass transition temperature of said at least one polymer having a glass transition temperature according to ISO 11357-2 published: 2014-07 of at least 180° C., an inorganic blowing agent, a thermally decomposable blowing agent, and a mixture thereof.

6 . The process for preparing expandable pellets according to claim 1 , wherein the polymer composition comprises a nucleating agent.

7 . The process for preparing expandable pellets according to claim 6 , wherein the nucleating agent is selected from the group consisting of talc, graphite, carbon black, titanium dioxide, and a mixture thereof.

8 . The process for preparing expandable pellets according to claim 1 , wherein a pelletized material obtained after b) is discharged and supplied to a drying process.

9 . The process for preparing expandable pellets according to claim 1 , wherein a pelletized material obtained after c) is discharged and supplied to a drying process.

10 . A method, comprising:
installing foamed particles obtained by inputting energy into the expandable pellets produced by the process according to claim 1 , in an aircraft, ship, or vehicle.

11 . The method according to claim 10 , wherein the vehicle is an electromobility vehicle.

Assignees

• Evonik Operations Gmbh

Inventors

• Trassl Christian
• Niepert Melanie
• Hopf Florian
• Holleyn Denis
• Ganglauf Mona

Classifications

• B29B9/16

  Auxiliary treatment of granules · CPC title

• C08J9/16

  Making expandable particles · CPC title

• C08J2381/06

  Polysulfones; Polyethersulfones · CPC title

• C08J2379/08

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title

• C08J9/18

  by impregnating polymer particles with the blowing agent · CPC title