Granted Patent B2

US 12,496,753 · App. 18/041,771 · Granted Dec 16, 2025

Inventors: Christian Traßl (Warmensteinach, DE); Melanie Niepert (Frankfurt, DE); Florian Hopf (Neu Isenburg, DE); Denis Holleyn (Hofheim am Taunus, DE); Mona Ganglauf (Hoechst, DE)

Assignee: Evonik Operations GmbH

B29C44/3461B29B9/065B29B9/16C08J9/16C08J9/18B29K2079/085B29K2081/06C08J2379/08C08J2381/06

Abstract

Claims (19)

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.

Priority Claims (1)

Continuity (1)

References Cited (76)