All posts tagged comfort

Tack-Free Polythiourethane Gels

Patent Title: SOFT ISOCYANATE-CROSSLINKED POLYMER SUBSTANCE AND ASSOCIATED PRODUCTS

Number/Link: WO2017/054797 (German)

Applicant/Assignee: Technogel

Publication date: 6-april-2017

“Gist”: Tack-free polyurethane gels are made from polythiols

Why it is interesting: Very soft polyurethane elastomers or “gels” can be made using high functionality isocyanate and monols (as co-invented by myself – e.g. EP1389222 ) or by reacting a high functionality polyol/siocyanate system at low isocyanate-index (as invented by Bayer – later spun off as Technogel). PU gels are useful as shock dampers, gaskets and cushions but are always tacky and need to be covered or wrapped, which changes their damping and hardness characteristics. According to this invention tack-free gels without the need for covering can be produced by using polythiols instead of polyols, resulting in poly(thiolurethanes) instead of polyurethanes. This is interesting and surprising and I wonder if it would work with the monol-gels as well.

Thiolurethane linkage

4 Comments

by Gerhard Bleys on April 7, 2017 • Permalink

Posted in Elastomers

Tagged bicycle saddle, comfort, cushioning, gels, mercaptane, shore OO, thiolurethane, thionurethane, thiourethane

Posted by Gerhard Bleys on April 7, 2017

https://purpatents.com/2017/04/07/tack-free-polythiourethane-gels/

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

Polyrotaxanes in Flexible Foams

Patent Title: POLYOL COMPOSITION FOR PRODUCING FLEXIBLE POLYURETHANE FOAM..

Number/Link: US20160304689

Applicant/Assignee: Toyo Tire & Rubber

Publication date: 20-10-2016

“Gist”: Polyrotaxanes in PU foam reduces ‘wobble’ when used in car seats

Why it is interesting: The use of polyrotaxanes in polyurethanes is not new and has been discussed before in this blog. According to the current invention polyrotaxanes with OH-functional rings can be incorporated in flexible foams, where they are said to reduce tensile stress while having little impact on compressive properties. When these foams are used in (e.g.) vehicle seats that are subject to low frequency sideways vibrations, they should reduce the sense of “wobble” of the occupants. The theory is that under tension the rings slide along the axis molecule equalizing stresses. In the examples polyrotaxanes with 11000 to 20000 molecular weight PEG axis molecules are used with cyclodextrin rings having an OHv of 43 to 85.

Polyrotaxane-crosllinked polyurethane under stress (schematic)

Polyrotaxane-crosslinked polyurethane under stress (schematic)

Innovation in Polyurethanes

All posts tagged comfort

Tack-Free Polythiourethane Gels

In Situ Reticulated Viscoelastic Foams

Polyrotaxanes in Flexible Foams

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