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

Dispersions of Comb-Structured Polyurethanes

Patent Title: POLYURETHANE-BASED BINDER DISPERSION

 Number/Link: WO2016122569

Applicant/Assignee: Hewlett-Packard

Publication date: 4-08-2016

Gist”:  Aqueous dispersions of “1,2”-dihydroxypolyacrylate -based polyurethanes

Why it is interesting: According to this invention aqueous dispersions can be made of “comb -structured” polyurethanes which are based on polyols having two hydroxyl groups at one end of the chain.  The “1,2”-diols are made by copolymerizing (e.g.) methylmethacrylate and n-butylmethacrylate together with thioglycerol up to a Mw of about 2000. The polyols can then be reacted with isocyanate and dimethylolpropionic acid for dispersion in water. The dispersions are said to have a small average particle size (10-100 nm) and be especially useful as binders for inkjet-ink.

Thioglycerol

Thioglycerol

Melt-Dispersed Polymer Polyols

Title: PROCESS FOR MAKING A POLYMER POLYOL

 Number/Link: WO2015/165761  (German)

Applicant/Assignee: BASF

Publication date: 5-11-2015

Gist”: Polymer polyols are prepared by melt-dispersing SAN into a carrier polyol using a specific stabilizer

Why it is interesting: Polymer polyols, or ‘graft polyols’, contain finely dispersed polymeric particles and are especially useful for the production of flexible polyurethane foams.  Usually polymer polyols are produced by in-situ polymerization of styrene-acrylonitrile (SAN)- or polyurea particles in a carrier polyol. In this invention, polymer polyols are prepared by dispersing molten SAN into a carrier polyol using shear mixing and a specific stabilizer.  The stabilizer is a (preferably) comb-shaped polyol-SAN copolymer, and is described in another BASF application: WO2015/165878. The polymer polyols are said to have a fine and uniform particle size distribution, a low viscosity and a high stability against segregation.

SAN

SAN

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