Novel foaming process for production of foam materials

Patent metadata

Field	Value
Publication number	US-2024190052-A1
Application number	US-202418412259-A
Country	US
Kind code	A1
Filing date	Jan 12, 2024
Priority date	Jan 16, 2019
Publication date	Jun 13, 2024
Grant date	—

Abstract

A production process can produce foam materials from a polymer composition. This production process may involve preheating a polymer composition to be foamed. The preheated composition may then be foamed by a thermal process assisted by microwaves. The foaming may occur in an apparatus that has a heating device. The polymer composition may contain a blowing agent.

First claim

1 - 10 . (canceled)

11 . A process for producing a foam, the process comprising:
preheating a polymer composition to be foamed, and foaming the polymer composition containing a blowing agent in an apparatus having a thermal heating device for heating to an internal temperature of the apparatus T s and irradiating simultaneously the polymer composition by at least one microwave source of the apparatus, wherein the polymer composition is preheated in the apparatus at a temperature between a minimum of 80° C. below and a maximum of 10° ° C. above the internal temperature of the apparatus T s , and wherein the temperature differential between a coldest point and a hottest point within the polymer composition after the preheating is not greater than 15ºC.

12 . The process according to claim 11 , wherein the polymer composition is a material that forms a rigid foam after the foaming.

13 . The process according claim 11 , wherein the polymer composition, prior to the foaming, is preheated to a preheating temperature T v above a glass transition temperature T s of the polymer composition.

14 . The process according to claim 11 , wherein a preheating temperature T v is between 110 and 190° C., and a preheating time is at least 85 min.

15 . The process according to claim 11 , wherein microwave radiation from the at least one microwave source has a frequency between 0.85 and 6.0 GHz.

16 . The process according to claim 11 , wherein the polymer composition comprises PMI (polymethacrylimide), wherein a preheating temperature T V is between 120 and 190° C., and wherein an internal temperature of the apparatus T S is between 180 and 240° C.

17 . The process according to claim 11 , wherein the polymer composition comprises PMMA or methacrylate-based copolymer, wherein a preheating temperature T V is between 110 and 140° C., and wherein an internal temperature of the apparatus T S is between 120 and 190° C.

18 . The process according to claim 12 , wherein the rigid foam is selected from the group selecting of P(M)I (poly(meth)acrylimide), PMMA, a methacrylate-based copolymer, polyvinyl chloride (PVC), polypropylene (PP), polyurethane (PU), a polysulfone, and a poly(ether)imide.

19 . The process according to claim 14 , wherein the preheating time is at least 110 min.

20 . The process according to claim 11 , wherein a preheating time is at least 70 min.

21 . The process according to claim 11 , wherein a preheating time is at least 80 min.

Assignees

• Evonik Operations Gmbh

Inventors

• Richter Thomas
• Liebe Andreas
• Trassl Christian
• Becker Florian
• Ma Junyong Vincent

Classifications

• B29K2105/04

  cellular or porous · CPC title

• B29C2035/0855

  using microwave · CPC title

• B29C35/0805

  using electromagnetic radiation · CPC title

• B29L2007/002

  Panels; Plates; Sheets · CPC title

• B29K2033/12

  Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate · CPC title