In Situ Reticulated Viscoelastic Foams

Patent Title: VISCOELASTIC AND RETICULATED POLYURETHANE FOAM AND THE PREPARATION THEREOF

 Number/Link: WO2016/198433

Applicant/Assignee: Covestro

Publication date: 15-dec-2016

Gist”: Composition of 3 semi-miscible polyols and a surfactant

Why it is interesting: This case claims a polyol composition for the preparation of a viscoelastic, reticulated foam without the need for a separate reticulation step. The composition consists of (at least) three polyols and a surfactant:  a low mole-weight all-PO ‘rigid’ triol, a conventional flexible polyol, a high- or all-EO polyol and some off-the-shelf silicone surfactant.  The composition is foamed with water and polymeric MDI or a polymeric MDI/TDI mixture. This is a well-known composition and it is hard to see why this should result in a reticulated foam – unless maybe in some fine-tuned cases.  Apart from the ball rebound being less than 15% the claims do not mention any parameters related to reticulated foam (such as airflow). It is doubtful (in my opinion) that this will get granted.

Cell structure of a reticulated foam

Cell structure of a reticulated foam

Using PU Foams as a Template for Silicone Foams

Title: FOAM-LIKE MATERIALS AND METHODS FOR PRODUCING SAME

 Number/Link:US2014/154491

Applicant/Assignee: Allergan

Publication date: 5-06-2014 (priority PCT/US)

Gist”: A polyurethane foam is impregnated with a curable liquid silicone.  After curing of the silicone the PU is removed.

Why it is interesting: According to this invention open celled polyurethane (or melamine) foam structures can be ‘converted’ into other materials like silicone, polyesters, polyolefins etc. by impregnating them with the the appropriate raw materials, curing and removing the ‘base’ foam. Optionally the ‘converted’ foam structure can be impregnated and cured again until the desired porosity is obtained.  In an example a PU foam was impregnated with a HTV silicone rubber.  After curing, the PU structure was removed using hydrogen peroxide.
While undoubtedly very interesting foam materials can be made in this way, the process seems messy and not very practical.

A 'base foam structure' (left has been impregnated and cured with another polymer (right).

A ‘base’ foam (left) and an impregnated foam (right) according to the invention.

 

  • Pages

  • Categories

  • Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 1,090 other followers

  • Follow Innovation in PU on Twitter

%d bloggers like this: