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

Flexible Foams containing Polyurethane Phase Change Gels

Title: Polyurethane Gel-Like Polymers, Methods and Use in Flexible Foams  

 Number/Link: US2013/0296449

Applicant/Assignee: PETERSON CHEMICAL TECHNOLOGY

Publication date: 07-11-2013

Gist”:   “Polyurethane phase change gels” prepared from polyurethane gels and conventional PCMs are incorporated into polyurethane or latex flexible foams to improve thermal comfort.

Why it is interesting: This application is closely related to the application discussed in the previous post but instead of a plasticized styrenic triblock copolymer, now a polyurethane gel is used. The PU gel is produced from conventional raw materials at low NCO-index (about 60%) together with plasticizers.

A Polyurethane Gel

A Polyurethane Gel

Incorporating “Phase Change Gels” into Flexible Foams for Improved Thermal Comfort

Title: Thermal Storage Gelatinous Triblock Copolymer Elastomer Particles in Polyurethane Flexible Foams

 Number/Link: US2013/295371

Applicant/Assignee: PETERSON CHEMICAL TECHNOLOGY

Publication date: 07-11-2013

Gist”:  Particles of  “phase change gels” prepared from plasticized styrenic TPEs and conventional PCMs are incorporated into polyurethane or latex flexible foams

Why it is interesting: A conventional phase change material (PCM) selected from alkanes, PEGs, hydrated salts ect. with a transition temperature between 20 and 35°C is melt-blended with a plasticized styrenic triblock copolymer like SBS, SIS, SEBS etc. to form a “phase change gel”. The gel is then comminuted and added to a flexible foam forming composition in an amount of about 30 pphp. The resulting foams have an increased thermal conductivity which together with the temperature buffering properties of the PCM improves thermal comfort. The flexible foams are useful in application such as matresses, pillows, automotive cushioning, shoe inserts, medical foams and the like. In my opinion especially useful for viscoleastic (“memory”) foams which are known to suffer from thermal discomfort problems.

Effect of "gel PCM" on heating rate of flexible foam according to the invention.

Effect of “gel PCM” on heating rate of flexible foam according to the invention.