All posts tagged fillers

A New Way to Remove Monomeric Isocyanate from Prepolymers

Title: REDUCTION OF THE FRACTION OF MONOMERS COMPRISING ISOCYANATE GROUPS IN MOISTURE-CURING POLYURETHANE COMPOSITIONS

 Number/Link: US2013/0158210

Applicant/Assignee: Sika

Publication date: 20-06-2013 (priority PCT/EP)

“Gist”: Reduction of monomeric MDI in moisture curable prepolymers by addition of amino functional silica particles.

Why it is interesting: As noted in some previous posts in this blog (*) reduction of monomeric isocyanate from moisture curable systems is an important trend in PU systems development. The current invention solves this problem by adding isocyanate-reactive SiO2 particles to the prepolymer composition.  The particles have a preferred average size of 50-60μm, are (nano-)porous with a large specific surface area and have been chemically modified with (preferably) aminosilanes to make them amino-functional. Particles of this type with different functional groups are commercially available under the QUADRASIL tradename.
(*) Note that you can use the ‘search’ or ‘category’ boxes on the right (or in case of a mobile device on the bottom) of this page to help you navigate the site.

Porous Silica Particles

Porous Silica Particles

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by Gerhard Bleys on June 27, 2013  •  Permalink
Posted in Adhesives-Coatings, Isocyanates and Prepolymers
Tagged , , , ,

Posted by Gerhard Bleys on June 27, 2013

https://purpatents.com/2013/06/27/a-new-way-to-remove-monomeric-isocyanate-from-prepolymers/

Rigid Polyurethane Foam Containing Expandable Particles

Title: Highly Insulating Polyurethane Foam and Method for Manufacturing Same

 Number/Link:US2013/0150470

Applicant/Assignee: Cheil Industries

Publication date: 13-06-2013 (priority PCT/KR)

“Gist”: Rigid foams comprising thermally expandable particles which penetrate cell walls and which are covered with an infrared absorbing filler show improved insulation properties.

Why it is interesting: The invention claims to improve insulation properties of rigid foams by including about 5% (on the total resin) of organic thermally expandable particles with a diameter of about 5 μm before expansion and of about 50 μm after expansion. A filler chosen from carbon black, graphite, carbon nanotubes and the like is added as well. After the foam is formed the expanded particles penetrate the cell walls, are supposedly covered with the filler and are believed to reduce the radiation component of the thermal conductivity. Foam properties given in the examples show a density of about 35 kg/m³ with a thermal conductivity of about 0.0160 kcal/m.h.ºC (or about 0.019 W/m.K if I converted this correctly).

fig 2 form the patent. Large circles are expanded particles, smaal circles is filler.

Fig 2 form the patent: large circles are the expanded particles, the small circles represent the filler.

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by Gerhard Bleys on June 18, 2013  •  Permalink
Posted in Rigid Foams
Tagged , , , , , , ,

Posted by Gerhard Bleys on June 18, 2013

https://purpatents.com/2013/06/18/rigid-polyurethane-foam-containing-expandable-particles/

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