UV Resistant Viscoelastic Foams


 Number/Link: WO2018/111806

Applicant/Assignee:  Dow

Publication date: 21 June 2018

Gist”: VE foams using S-containing polyether polyols

Why it is interesting: According to this invention sulfur containing polyols improve the UV resistance of polyurethane materials.  It is believed that sulfur acts as a UV absorber incorporated into the polymer, thereby reducing the need for additives such as antioxidants.  In the examples an S-containing polyether diol is prepared by reacting 2,2′-thiodiethanol with propyleneoxide up to an OH value of  188 mg KOH/g. The diol is then used in an amount of 5 to 15% on the total polyol blend to prepare low resilience flexible foams showing an improved UV resistance.





Polyamide Polymer Polyols


 Number/Link: WO2017/216209

Applicant/Assignee:  BASF

Publication date: 21 December 2017

Gist”: Polyamide particles from polyether diamine and adipic acid are dispersed in polyol

Why it is interesting: Conventional polymer polyols contain either SAN-, polyurethane- or polyurea particles (see e.g. here).  According to this invention, polymer polyol dispersions can also be prepared by reacting a diamine, containing at least 50 wt% of a linear polyether having two terminal primary amine groups with a dicarboxylic acid (e.g. adipic acid) in a polyether polyol.  The reaction results in a dispersion of polyamide particles in the polyether polyol, stabilized by the polyether diamine. The polymer polyols are useful for flexible foam production and are said to show an improved hydrolysis resistance.


Adipic acid

Flexible Foams Containing PPE Polyols


 Number/Link: WO2015/041905

Applicant/Assignee: SABIC

Publication date: 26-03-2015

Gist”: Use of poly(phenylene ether) polyols in flexbile foams

Why it is interesting: As expected Sabic continue their series on the use of poly(phenylene ether) in polyurethane materials. This application is about the use of (some) PPE polyol in flexible foams. The resulting foams are said to have improved hardness, tear- and tensile strength. In the examples 10 to 40% of a PPE diol (on total polyol) is used together with other polyols, MDI or TDI and water as blowing agent, resulting in flexible foams with densities ranging from about 25 to 50 kg/m³. The PPE diol is a copolymer of 2,6-dimethylphenol and 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane with an equivalent weight of about 1000.

PPE diol used in the invention. Q5 and Q6 pare methyl.

PPE diol used in the invention. Q5 and Q6 are methyl groups.

Classic PU Patent of the Month: The First Polyether Foams (1951)

Title: Verfahren zur Herstellung von Kunststoffen

 Number/Link: DE974371 (German)

Applicant/Assignee: Bayer AG

Publication date: 12-08-1960

Gist”: A prepolymer from a polyether polyol and an excess of isocyanate is reacted with water to produce an elastomeric  foam.

Why it is interesting: This patent specifies the first polyether prepolymers and polyether  foams as invented by Otto Bayer and co-workers.  In the examples an all-EO, 4000 MW triol, prepared from trimethylolpropane and  ethylene oxide is reacted with a surplus of TDI resulting in a 3.2% NCO prepolymer.  This prepolymer is reacted with water to form either elastomeric films or elastomeric (flexible) foams. There are only two claims, the first covering  polyether prepolymers, the second covering both “one-shot” and “full prepolymer” water-blown polyether foams:


1. Verfahren zur Herstellung von Kunststoffen,
dadurch gekennzeichnet, daβ Polyglykolather mit
einem Molekulargewicht von mindestens 500 und
mindestens zwei endstandigen Hydroxylgruppen
mit einem Übersehuβ über die berechnete Menge
an polyfunktionellen aliphatischen oder aromatischen
Isocyanaten und die erhaltenen Polyglykolätherisocyanate
mit Verbindungen mit reaktionsfahigem Wasserstoff
umgesetzt werden.

2. Ausführungsform des Verfahrens nach Anspruch
1, insbesondere zur Herstellung von Schaumstoffen,
dadurch gekennzeichnet, daβ als Verbindung
mit reaktionsfahigem Wasserstoff Wasser verwendet
wird und die Umsetzung mit Wasser gleichzeitig
mit der oder anschlieβend an die Umsetzung
der Polyglykolather und polyfunktionellen
Isocyanate erfolgt.

Dr. Otto Bayer

Dr. Otto Bayer