PU Flexible Foams with Reduced Acetaldehyde Emissions

Title: METHOD FOR THE REDUCTION OF ALDEHYDE EMISSION IN POLYURETHANE FOAM

Number/Link: WO2017/134296

Applicant/Assignee: Huntsman

Publication Date: 10 August 2017

“Gist”: Cyanoacetamide is used as aldehyde scavenger

Why it is interesting: Reduction of aldehyde emissions from (especially flexible) polyurethane foams remains an important issue and has already been discussed a number of times on this blog. According to this case the use of (pref) 0.05 to 0.5 pbw of cyanoacetamide in a flexible foam formulation will reduce the emission of formaldehyde, acetaldehyde, propionaldehyde, and possibly of higher aldehydes as well.
While an interesting compound, the use of cyanoacetamide in polyurethanes is not new and the effect is hardly surprising.

Cyanoacetamide

 

Non-Isocyanate Polyurethane Flexible Foams

Title: NON ISOCYANATE POLYURETHANE FOAMS

Number/LinkUS2017/0218124

Applicant/Assignee: Faurecia

Publication Date: 3 august 2017

“Gist”: Flex foams from a blend of two polyfunctional cyclocarbonates, a polyamine and HFC blowing agent.

Why it is interesting: While non-isocyanate polyurethanes are well known by now, examples of NIPU foams, especially flexible foams are rare. According to this case NIPU foams ‘having good resilience and low density’ can be prepared by reacting two polyfunctional carbonates A and B with a polyamine in the presence of a blowing agent and a catalyst. Cyclocarbonate A is (pref) trimethylolpropaneglycidylether carbonate and B is a polyetherpolyol with the OH groups replaced by glycidylcarbonate groups, for example an alkoxyalated trimethylolpropaneglycidylether carbonate. The polyamine is e.g. 1,6 diaminohexane.  The ratio A:B is preferably about 60:40.  In the examples no value for the resilience is given (but my guess based on the Tg is that it is probably not very high) and the lowest moulded density achieved is 140 kg/m³. So still a long way to go..

Glycidylether carbonate of alkoxylkated trimethylolpropane

TPU Aerosol

Title: POLYURETHANE AEROSOL COMPOSITIONS, ARTICLES, AND RELATED METHODS

Number/Link: US20170198150

Applicant/Assignee: 3M

Publication Date: 13-july-2017  (priority PCT)

“Gist”: Aqueous dispersion of a hydrazide-extended  TPU can be sprayed as aerosol to make protective films

Why it is interesting: An aqueous thermoplastic polyurethane dispersion is prepared from a non-yellowing diisocyanate, e.g. bis(4-isocyanatocyclohexyl), a diol (e.g. PPG2000), a difunctional hydrazine or hydrazide chain extender (e.g. 1,3-diaminourea) and a water solubilizing compound (e.g. dimethylolpropionic acid).  Together with a propellant the, composition is shelf-stable and can be aerosol-sprayed to form clear, non-yellowing protective films.

3M’s aerosol-sprayed protective film.

Matte, Self-Healing Polyurethane Powder Coatings

Title: POLYURETHANE COATING COMPOSITION

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

High Resiliency Polyurethane Foams

Title: HIGH RESILIENCY POLYURETHANE FOAMS MADE WITH HIGH FUNCTIONALITY, HIGH EQUIVALENT WEIGHT POLYOLS WITH MAINLY SECONDARY HYDROXYL GROUPS

Number/Link: WO2017/062150

Applicant/Assignee: Dow

Publication Date: 13 April 2017

“Gist”: Use of high functionality polyols increases the resilience of flex foams

Why it is interesting:  According to this invention the resilience of flexible PU foams can be increased by using, as part of the polyol composition, a random EO/PO polyether polyol which has an equivalent weight of at least 1500, a functionality of  at least 5, a secondary hydroxyl group content of at least 70%, an unsaturation value of at most 0.01 meq/g and an EO content between 5 and 30%.  In the examples, sorbitol initiated polyols are used in both MDI and TDI-based systems, resulting in ball rebound values of up to 60% at densities of about 30 kg/m³.  As I have shown in the past (US5521226) the same (or arguably an even stronger) effect on resilience can be obtained with other high functionality polyols, indicating that the unsaturation value, primary OH content, EO content and equivalent weight are probably not relevant to the resilience increase.

Sorbitol