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

Improved Cellopening System for Flexible Foams

Title: Process For Producing Flexible Polyurethane Foam Using Natural Oil Polyols

Patent Number & Link: US2013/197114

Applicant/Assignee: Air Products

Publication date: 1-08-2013

Gist”: Use of 2-cyanoacetamide as cellopener together with a dipolar aprotic liquid as “cellopening aide” in moulded flexible foams.

Why it is interesting: The use of compounds with an active (acidic) methylene group like 2-cyanoacetamide as cellopener for flexible foam is known (US6136876) but has some disadvantages like low solubility in polyol and low reproducibility when dissolved in water. The use of these cellopeners together with dipolar aprotic solvents like dimethylsulfoxide (DMSO) or glycols like PEG200 supposedly solves these problems and allows for the use of a lower amount of the cellopener.  In the examples 0.03 pphp of cyanoacetamide is used together with 0.12pphp of DMSO. Strangely claim 1 expressly states the use of at least one NOP (natural oil based polyol) while this does not seem relevant to the invention.

2-cyanoacetamide

2-cyanoacetamide

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