Catalyst System for Frothed Foams

Patent Title: METHOD FOR DELAYING CURING IN POLYURETHANE AND COMPOSITIONS AND ARTICLES MADE THEREFROM

 Number/Link: WO2018/075302

Applicant/Assignee:  Rogers

Publication date: 26-April-2018

Gist”: A mixture of  a metal acetylacetonate and a catalytic inhibitor prevents premature curing

Why it is interesting:  A catalyst system that prevents premature curing of frothed (PORON® – type) foams consists of  ferric acetylacetonate catalyst and a β-diketone inhibitor e.g. acetylacetone or dibenzoyl methane. The catalyst combination allows for handling of the raw materials at 55°C for 5 minutes without reacting.  Frothed foams tend to have improved properties, like compression set, compared to conventional foams.

Tris(acetylacetonato)iron(III)

Tris(acetylacetonato)iron(III)  (Wikipedia)

Scorch-Proof Polyurethane Foams

Patent Title:  LOW EMISSIONS SCORCH INHIBITOR FOR POLYURETHANE FOAM

 Number/Link: WO2018/064521

Applicant/Assignee:  Vanderbilt Chemicals

Publication date: 5 April 2018

Gist”: A synergistic mixture of antioxidants prevents scorch

Why it is interesting: “Scorch” is a discolouration of the center of (especially low-density flexible) polyurethane slabstock foams as a consequence of excessive heat build-up during production. It is believed to be the result of free-radical reactions of foaming components and additives, like the dimerisation of BHT – a common antioxidant. According to this invention the combination of three to (optionally) 5 specific antioxidants show an unexpected synergy towards prevention of scorch. The inventive composition consists of 2,2,4-trimethyl-1,2-dihydroquinoline, a lactone (e.g. 3-alkyl- benzofurane-2-one), a phenolic compound (e.g. an alkylated monophenol) and optionally a tocopherol (a vitamine E-type phenolic compound) and a phosphite compound.  The composition is said to have the added advantage of showing low volatile chemical emissions.

quinoline

2,2,4-trimethyl-1,2-dihydroquinoline

Polyurethanes from Alpha Glucan

Patent Title: POLYURETHANE POLYMERS COMPRISING POLYSACCHARIDES

 Number/Link: WO2018/017789

Applicant/Assignee:  Du Pont

Publication date: 25 january 2018

Gist”: Polyurethanes containing poly alpha 1,3-glucan

Why it is interesting: The invention is related to the preparation of different types of polyurethanes comprising poly alpha 1,3-glucan, which is a polymeric D-glucose having alpha 1,3 glycosidic bonds (as opposed to most natural glucose polymers which show α or β 1,4 glycoside linkages). Alpha 1,3 glucan can be prepared by enzymatic polymerization using sucrose and a glycosyltransferase. The glucan can be mixed with polyols and reacted with isocyanates to prepare polyurethanes.  Many examples are given ranging from PUDs, films, flexible foams to TPUs.

glucan

Poly alpha 1,3-glucan

 

Isocyanate-Free Polyaminal-Polyurethane Foams

Patent Title: SYSTEM FOR DIMENSIONALLY STABLE ISOCYANATE-FREE POLYURETHANE FOAM

 Number/Link: WO2018/005142

Applicant/Assignee:  Dow

Publication date: 4 January 2018

Gist”: Polyaldehydes are reacted with polycarbamates in the presence of an acid catalyst, a metal oxide powder and a blowing agent.

Why it is interesting: According to this invention hydrolytically-stable foams can be prepared from a low molecular weight difunctional aldehyde and a polycarbamate with a functionality of about 3.5 to 4 and an equivalent weight of about 200 to 300, in the presence of a blowing agent and a protic acid as catalyst. Surprisingly the foams are rendered hydrolytically stable by the incorporation of a metal oxide powder with a specific particle size. In the examples polycarbamates are prepared by capping high functionality polyols with methylcarbamate and are then reacted with 1,4-cyclohexanedicarboxaldehyde together with p-toluensulfonic acid as catalyst, HFC245fa as blowing agent and MgO powder. The foams show densities of 130-170 kg/m³ and are said to be useful as sealants.

CHDA

Cyclohexanedicarbaldehyde

PCM-Containing Viscoelastic Foams

Patent Title: VISCOELASTIC POLYURETHANE FOAM WITH COATING

Number/Link: WO2017/210439

Applicant/Assignee: Dow

Publication date: 7 December 2017

“Gist”: Open-celled visco-foam is impregnated with an aqueous dispersant composition containing a phase change material

Why it is interesting: According to Dow, open-celled viscoelastic polyurethane foams can be prepared by using a acid-modified polyolefin latex cellopener, as discussed before in this blog. In the current invention these open-celled foams are impregnated with an aqueous composition comprising an ionomer (a sodium salt of a maleic anhydride copolymer) and a microencapsulated PCM. The composition is said to ‘coat’ the cell struts with PCM and increase the comfort properties of the foam.
I wonder if with this process enough PCM can be in introduced to have a noticeable effect.

bluewave

Dow’s proprietary BLUEWAVE dispersion process is used to prepare the cellopening latex