Aliphatic Polyisocyanurate Composites


 Number/Link: WO 2017/191216  (German)

Applicant/Assignee:  Covestro

Publication date: 9 November 2017

Gist”: Partially trimerized aliphatic diisocyanates are mixed with glass fiber and reacted using a trimerization catalyst

Why it is interesting: Conventional fiber-reinforced composites based on unsaturated polyesters, epoxies, polyurethane and the like are not weather-stable and need to be coated for outdoor use. Weather stable polyisocyanurate composites are known (WO2007/096216 – Huntsman) but are based on aromatic diisocyanates and show high reactivity and short ‘pot life’. According to this invention, PIR composites with improved reaction profile and weatherability can be prepared from partially trimerized aliphatic diisocyanates with a diisocyanate monomer content of less than 20% (w/w). In the examples commercially available HDI and IPDI trimer is used together with short glass fiber and a potassium acetate/PEG 400 blend as catalyst cured at a temperature of 160 to 180°C.

Isophorone diisocyanate (IPDI)


Monodisperse Polymer Polyol


 Number/Link: WO2017/172417

Applicant/Assignee:  Dow

Publication date: 5 october 2017

Gist”: Polymer polyol with a “monodisperse” particle size distribution is prepared by using a specific seeding dispersion

Why it is interesting: It is well known that the use of polymer polyols in flexible polyurethane foam formulations can result in improved airflow and load bearing properties. For optimal results the average particle size of the dispersed polymer needs to be similar to the cell wall thickness. According to this invention a SAN polymer polyol with a controlled and narrow particle size distribution can be prepared by using a seed dispersion which consists of an unsaturated macromer which, together with SAN particles of a particle size between 50 and 500 nm, is dispersed in a base polyol. The macromer is a PO/EO polyether with a (pref.) mole weight of 11000 to 14000 Da and having 4-5 OH groups and 1-2 reactive double bonds. The polymer polyol is prepared by dispersing the seed dispersion in the base polyol together with styrene, acrylonitrile and a solvent (e.g. isopropanol). After polymerization of the monomers the solvent is removed, resulting in a polymer polyol with at least 30% solids, average particle size of 1-3 μm and a size span of 1.25. In the examples the macromer is prepared by capping 1-2 OH groups of a 6-functional 90/10 PO/EO polyol with 3,3-isoprenyl-α,α-dimethylbenzylisocyanate.




PCM Containing PU Gels

Title: Temperature Regulating Polyurethane Gels

Number/Link: US2017/0210961

Applicant/Assignee: Technogel

Publication Date: 27 july 2017

“Gist”: Fatty acid ester PCMs are incorporated into Technogel-type gels without encapsulation

Why it is interesting: Polyurethane gels have been discussed before in this blog. The current invention is about “Technogel-type”  gels, made at low NCO-index and high functionality, that contain phase change materials (PCMs). The PCMs are esters of fatty acids that can be blended in molten state with the low EO polyol to form a clear solution, which is then reacted with isocyanate to form the gel. Despite not being encapsulated or forming a separate phase, the PCMs can reversibly melt and crsytallize while in the fluid phase of the gel. In the examples blends of lauryl laurate (C12-C12) and myristyl myristate (C14-C14) are used as PCM such that the phase change temperature is about 22-38°C.  The gels are said to be useful for ‘close to body’ comfort applications especially for use in matresses to improve sleeping comfort.

Lauryl laurate


Matte, Self-Healing Polyurethane Powder Coatings


Number/Link: WO2017/074835

Applicant/Assignee: Valspar

Publication Date: 4 May 2017

“Gist”: Coating composition comprising isocyanate and two polyester polyols having a similar Tg but a widely different equivalent weight.

Why it is interesting: Conventionally low gloss or “matte” coatings are the result of a microtextured surface achieved by certain fillers or by incompatible polymers and the like. According to this invention “ultra matte” finishes can also -surprisingly- be achieved from a (powder) coating composition comprising a (blocked) isocyanate and a mixture of two polyester polyols. Both polyols have a Tg between 40 and 60ºC prefereably differing not more than 5 to 8ºC, while the OHv of the first polyol is between 150 and 325 and that of the second between 15 and 35.  The ratio between first and second polyol is from about 1:1 to 1:3 w/w. Also surprisingly, the resulting coatings are said to show self-healing properties. An interesting composition but no examples of the polyesters or isocyanates used are given.

Car with matte finish

SiC-PU Nanocomposites


 Number/Link: WO2017/027231

Applicant/Assignee: 3M

Publication date: 16-feb-2017

Gist”: Surface modified SiC particles are dispersed in and covalently bound to a polyurethane matrix

Why it is interesting: Silicon carbide (carborundum) particles with an average particle size of about 500 nm are NCO-functionalized by reacting with a surface modfifying agent, e.g 2-triethoxysilylpropylisocyanate. The modified particles are then dispersed and covalently reacted into a polyurethane/polyurea matrix in an amount of 50-55% (w/w) on the composition. The composites can be made into highly erosion resistant films, for use on the outer surface of aircraft.