All posts in category dispersions

Improved “Black” Insulation Foams

Title: ISOCYANATE-BASED POLYMER FOAM COMPOSITE WITH IMPROVED THERMAL INSULATION PROPERTIES

Number/Link: US20140151593

Applicant/Assignee: Dow

Publication date: 5-06-2014 (Priority PCT/US)

“Gist”: Use of fluorinated carbon black to improve insulation value of rigid polyurethane foams

Why it is interesting: It is known that carbon black can be used to improve the insulation value of rigid foams by reducing the radiation component of the thermal conductivity. The carbon black however needs to have a very small particle size and needs to be extremely well dispersed into the reacting medium. According to the invention using a fluorinated carbon black improves the dispersion into the raw materials which, in turn, improves the final insulation value of the foam.
A small but valuable innovation.

Different grades of carbon black

Using PU Foams as a Template for Silicone Foams

Title: FOAM-LIKE MATERIALS AND METHODS FOR PRODUCING SAME

Number/Link:US2014/154491

Applicant/Assignee: Allergan

Publication date: 5-06-2014 (priority PCT/US)

“Gist”: A polyurethane foam is impregnated with a curable liquid silicone. After curing of the silicone the PU is removed.

Why it is interesting: According to this invention open celled polyurethane (or melamine) foam structures can be ‘converted’ into other materials like silicone, polyesters, polyolefins etc. by impregnating them with the the appropriate raw materials, curing and removing the ‘base’ foam. Optionally the ‘converted’ foam structure can be impregnated and cured again until the desired porosity is obtained. In an example a PU foam was impregnated with a HTV silicone rubber. After curing, the PU structure was removed using hydrogen peroxide.
While undoubtedly very interesting foam materials can be made in this way, the process seems messy and not very practical.

A 'base foam structure' (left has been impregnated and cured with another polymer (right).

A ‘base’ foam (left) and an impregnated foam (right) according to the invention.

Highly Stable Isocyanate Dispersions

Title: STORAGE-STABLE HYDROPHILIC POLYISOCYANATES

Number/Link: WO2014/053269 (German)

Applicant/Assignee: Evonik

Publication date: 10-04-2014

“Gist”: A uretdion-containing isocyanate prepolymer is reacted with a neutralized aminealkylsulfonic acid to produce a novel hydrophilic (latent) isocyanate which can be used in stable aqueous dispersions.

Why it is interesting: Aqueous dispersions of isocyanates are useful in many applications as adhesives, binders, crosslinkers etc, but usually suffer from a relatively short shelf life. Dispersions prepared according to the current invention supposedly lose less than 30% of their initial NCO value after 12 weeks storage at 50°C. In an example an aceton-solution of an IPDI-uretdion prepolymer with an isocyanate content of 1.5% is reacted with the sodium salt of an aminealkylsulfonate in water to an NCO value of 0.1%. After removal of the aceton the resulting dispersion had a latent isocyanate content of 4.5%

Reversible dimerization of isocyanate to uretdion.

Innovation in Polyurethanes

All posts in category dispersions

Improved “Black” Insulation Foams

Using PU Foams as a Template for Silicone Foams

Highly Stable Isocyanate Dispersions

Pages

Categories

Search

Follow this blog via email

Follow Innovation in PU on Twitter