Process for production of expanded thermoplastic elastomer

Patent metadata

Field	Value
Publication number	US-2016244587-A1
Application number	US-201415029686-A
Country	US
Kind code	A1
Filing date	Oct 17, 2014
Priority date	Oct 18, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

The invention relates to a process for production of expanded thermoplastic elastomer, said process comprising the steps of:
(e) adding monomers and/or oligomers used for producing the thermoplastic elastomer with or without further starting materials into a first stage of a polymer-processing machine, (f) mixing the monomers and/or oligomers and also the optionally added further starting materials and reacting the monomers and/or oligomers to give a polymer melt in the first stage of the polymer-processing machine, (g) passing the polymer melt into a second stage of a polymer-processing machine and adding a physical blowing agent with or without further starting materials to obtain a polymer melt comprising a blowing agent, (h) molding the polymer melt comprising a blowing agent into an expanded thermoplastic elastomer.

First claim

1 .- 15 . (canceled)

16 . A process for production of expanded thermoplastic elastomer, said process comprising the steps of:
(a) adding monomers and/or oligomers used for producing the thermoplastic elastomer with or without further starting materials into a first stage of a polymer-processing machine, (b) mixing the monomers and/or oligomers and also the optionally added further starting materials and reacting the monomers and/or oligomers to give a polymer melt in the first stage of the polymer-processing machine, (c) passing the polymer melt into a second stage of the polymer-processing machine and adding a physical blowing agent with or without further starting materials to obtain a polymer melt comprising a blowing agent, (d) molding the polymer melt comprising a blowing agent into an expanded thermoplastic elastomer.

17 . The process according to claim 16 , wherein the polymer-processing machine is a screw-plunger machine.

18 . The process according to claim 17 , wherein the first stage of the screw-plunger machine and the second stage of the screw-plunger machine are sectors of an extruder.

19 . The process according to claim 17 , wherein the first stage of the screw-plunger machine is a first extruder of a tandem extruder and the second stage of the screw-plunger machine is a second extruder of the tandem extruder.

20 . The process according to claim 17 , wherein the second stage of the polymer-processing machine comprises a melt pump, optionally with a melt sieve or a static mixer.

21 . The process according to claim 16 , wherein the expanded thermoplastic elastomer is an expanded pellet material.

22 . The process according to claim 21 , wherein the pellet material is obtained by forcing the polymer melt in step (d) through a pelletizing die regulated to a temperature in the range from 150 to 280° C., using a cutting device to cut the polymer melt forced through the temperature-regulated pelletizing die into individual expanding pellets and using a stream of liquid to export the pellets from the pelletizing chamber.

23 . The process according to claim 22 , wherein a temperature-regulated liquid flowing through the pelletizing chamber as a stream has a temperature in the range from 10 to 60° C. and a pressure in the range from 0.7 to 20 bar above ambient pressure.

24 . The process according to claim 21 , wherein the expanded pellet material has a bead weight in the range from 1 to 40 mg.

25 . The process according to claim 16 , wherein the blowing agent comprises carbon dioxide, nitrogen or a mixture of carbon dioxide and nitrogen.

26 . The process according to claim 25 , wherein the blowing agent comprises 50 wt % to 100 wt % carbon dioxide and 0 wt % to 50 wt % nitrogen and no further blowing agent.

27 . The process according to claim 16 , wherein the blowing agent comprises an organic blowing agent selected from alkanes, halogenated hydrocarbons or a mixture thereof.

28 . The process according to claim 16 , wherein the thermoplastic elastomer is a thermoplastic polyurethane.

29 . The process according to claim 16 , wherein the expanded thermoplastic elastomer has a density in the range from 30 to 350 g/l.

30 . The process according to claim 16 , wherein the expanded thermoplastic elastomer has an uninterrupted skin.

Assignees

• Basf Se

Inventors

• Gutmann Peter
• Däschlein Christian
• Ahlers Jürgen
• Marten Elke
• Kaminsky Torben
• Kempfert Dirk

Classifications

• B29B11/10

  Extrusion moulding · CPC title

• C08J9/34 Primary

  Chemical features in the manufacture of articles consisting of a foamed macromolecular core and a macromolecular surface layer having a higher density than the core · CPC title

• C08J9/141

  Hydrocarbons · CPC title

• C08J9/0066

  Use of inorganic compounding ingredients · CPC title

• C08J2375/08

  from polyethers · CPC title