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

In Situ Reticulated Viscoelastic Foams

Patent Title: VISCOELASTIC AND RETICULATED POLYURETHANE FOAM AND THE PREPARATION THEREOF

 Number/Link: WO2016/198433

Applicant/Assignee: Coverstro

Publication date: 15-dec-2016

Gist”: Composition of 3 semi-miscible polyols and a surfactant

Why it is interesting: This case claims a polyol composition for the preparation of a viscoelastic, reticulated foam without the need for a separate reticulation step. The composition consists of (at least) three polyols and a surfactant:  a low mole-weight all-PO ‘rigid’ triol, a conventional flexible polyol, a high- or all-EO polyol and some off-the-shelf silicone surfactant.  The composition is foamed with water and polymeric MDI or a polymeric MDI/TDI mixture. This is a well-known composition and it is hard to see why this should result in a reticulated foam – unless maybe in some fine-tuned cases.  Apart from the ball rebound being less than 15% the claims do not mention any parameters related to reticulated foam (such as airflow). It is doubtful (in my opinion) that this will get granted.

Cell structure of a reticulated foam

Cell structure of a reticulated foam

Green Tea Memory Foam

Patent Title: Foam with Green Tea Additive for Foam Mattresses, Pillows and Cushions

 Number/Link: US2016/0270549

Applicant/Assignee: Zinus

Publication date: 22-09-2016

Gist”: Green Tea is added to memory foam formulation

Why it is interesting: Powdered leaves of the Green Tea plant (Camellia sinensis) are added to memory foam formulations in an amount of less than 2% (w/w) on the total composition.  The Green Tea is said to kill bacteria, mites and molds and reduce the smell of the foam when used in pillows and mattresses for example. Since tea leaves are also claimed to “brighten eyesight, refresh the brain and resist radiation” it’s hard to know if the claim is true. If it doesn’t work it won’t hurt I guess.

Cammelia sinensis (Wikipedia)

Camellia sinensis (Wikipedia)

 

Novel Cellopener for Flexible- and Viscoelastic PU Foams

Patent Title: POLYURETHANE FOAM WITH AQUEOUS POLYMER DISPERSION  & VISCOELASTIC POLYURETHANE FOAM WITH AQUEOUS POLYMER DISPERSION

 Number/Link: WO2016/100306 & WO2016/100263

Applicant/Assignee: Dow

Publication date: 23-06-2016

Gist”: Dispersions of acid modified olefins in water act as cellopeners

Why it is interesting: According to this invention aqueous dispersions of acid-modified olefins can be used as cellopeners for conventional, high resilience and viscoelastic foams. The examples show that a 40% ‘solids’ dispersion of an acrylic acid – ethylene copolymer in water, used in about 1 to 2% on the total isocyanate-reactive composition has a clearly positive effect on foam air-flow properties. The polymer dispersions can be made according to Dow’s proprietary BLUEWAVE™ extrusion technology.

The BLUEWAVE dispersion process

The BLUEWAVE dispersion process

 

Flexible PU Foam with Very Low Resilience

Patent Title: LOW-RESILIENCE POLYURETHANE FOAM AND PRODUCTION METHOD THEREOF

 Number/Link: US2016/0024268

Applicant/Assignee: Mitsui

Publication date: 28-01-2016

Gist”: Use of trans-BIC in viscoelastic flex foam

Why it is interesting: According to this invention low resilience flexible foams can be produced by reacting a mixture of two (optionally three) polyether polyols, water, a crosslinker and a catalyst with 1,4-bis(isocyanatomethyl)cyclohexane (BIC) where the BIC consists of (pref) 90% or more of the trans isomer. Higher trans-isomer is said to result in higher airflow and a finer cellstructure. In the examples a high MW all-PO triol and a low MW EO/PO triol with 18% EO tip is used, together with BIC at an NCO index of 70%.  The resulting foams have a high airflow and a (very) low resilience at densities between 50 and 70 kg/m³. While trans-BIC is clearly an interesting aliphatic di-iso, it is not widely available.

trans-1,4-bis(isocyanatomethyl)cyclohexane

trans-1,4-bis(isocyanatomethyl)cyclohexane