All posts in category dispersions

Improved Nanoporous Insulation Materials

Title: AEROGEL-CONTAINING POLYURETHANE COMPOSITE MATERIAL

Number/Link: WO2013182506 (German)

Applicant/Assignee: BASF

Publication date: 12-12-2013

“Gist”: An aqueous dispersion based on an isocyanate and an isocyanate-reactive vinyl polymer is used to bind aerogel particles into an insulation material.

Why it is interesting: Binding (silica) aerogel (or xerogel or cryogel) particles into insulation panels using aqueous polyurethane binders is known. See e.g. my previous posts on the subject here, here and here. According to this invention both the insulation and processing properties of existing systems can be improved by using an aqueous dispersion of a vinyl polymer containing isocyanate-reactive side groups, together with an emulsifiable isocyanate. The polyvinyl is preferably water-soluble, the side groups being -OH, -SH, -NH2 or -COOH, a (preferred) example being poyvinylamine with a molecular weight from 10,000 to 500,000. The isocyanate used is preferably a modified HDI or IPDI. In the examples materials are shown with densities of about 120 kg/m³ and a thermal conductivity of about 16 mW/m.K.

SLENTITE (TM) aerogel-PU insulation panel by BASF

Polyurethane Particles for Oil Absorption

Title: METHOD FOR PRODUCING POLYURETHANE PARTICLES

Number/Link: US2013/0224376

Applicant/Assignee: Konishi Co.

Publication date: 29-08-2013

“Gist”: A PU latex is prepared from an emulsion of an NCO-prepolymer in water which is crosslinked with a triamine in the presence of hydrophilic silica particles. The latex is then spray dried to form oil absorbing particles.

Why it is interesting: An NCO-ended IPDI-PTMEG prepolymer is dispersed in water an then crosslinked with a triamine. To the resulting latex, hydrophilic silica particles are added and the composition is then sprayed into a high temperature atmosphere to evaporate the water and form the particles. The size of the silica particles is about 20 nm and a factor 30 smaller then the PU particles. The silica supposedly covers the PU particles so that they do not cohere and show good flow properties. The particles can be used to absorb natural fats and oils (triglycerids) Useful (I assume) in the pharmaceutical, cosmetic and agricultural industries (controlled release, perfumes, repellents..)

lab spraydryer schematic (Wikipedia)

Aqueous Polyurethane Dispersion with Integrated Nanoparticles

Title: AQUEOUS DISPERSIONS OF POLYURETHANE AND NANOPARTICLES

Number/Link: WO2013/059106

Applicant/Assignee: Bayer

Publication date: 25-04-2013

“Gist”: Amino-functional inorganic nanoparticles are reacted with residual isocyanate groups of a PUD-forming polyurethane prepolymer and subsequently dispersed in water.

Why it is interesting: A water-dispersible polyurethane prepolymer is made from isocyanate, polyol and chain extender in which polyol and/or chain extender comprise ionic or potentially ionic groups. The prepolymer is produced with a surplus of isocyanate which is subsequently reacted with amino-functional inorganic nanoparticles. The nanoparticles consist of e.g. metal oxides which were reacted with a “bridging compound” comprising an isocyanate-reactive group (NH2 or OH) and a particle-reactive group e.g. a halogen or silane group. The polyurethane with covalently integrated nanoparticles can then be dispersed in water using a known process. The resulting PUD has a high shelf-life and can be used in coatings, adhesives, films etc. with improved properties.

Polyurethane dispersion and film made from it. (Wikimedia)

Innovation in Polyurethanes

All posts in category dispersions

Improved Nanoporous Insulation Materials

Polyurethane Particles for Oil Absorption

Aqueous Polyurethane Dispersion with Integrated Nanoparticles

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