All posts tagged polyether polyol

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

Classic PU Patent of the Month: ICI on “High EO – Pure MDI” Flexible Foams (1991)

Patent Title: Polyurethane Foams

Number/Link: EP0547765

Applicant/Assignee: ICI

Publication date: 23-06-1993

“Gist”: Flexible foams can be based on 4,4’MDI if the polyol contains 50 to 85% EO

Why it is interesting: The first flexible PU foams were all based on toluene diisocyanate and so-called “conventional polyols” (i.e. almost all-propylene oxide polyols). Attempts to replace TDI by the only other commercially viable diisocyanate (4,4′ MDI) failed because of premature phase separation of the highly symmetrical polyurea ‘hard block’, resulting in unstable foaming. The problem was eventually solved by using prepolymers and polymeric MDI, as mentioned before. More than 10 years later it was shown that it is possible to make flexible foams with 4,4′-MDI if the polyol is polar enough to prevent early phase separation. This was established by using polyols with high ethylene oxide content. The resulting foams have superior comfort and durability properties compared to both TDI and MDI flexible foams.

4,4′-MDI

TPU for 3D Printing

Title: METHODS OF USING THERMOPLASTIC POLYURETHANES IN FUSED DEPOSITION MODELING AND SYSTEMS AND ARTICLES THEREOF .

Number/Link: WO2015/109141

Applicant/Assignee: Lubrizol

Publication date: 23-07-2015

“Gist”: TPU with specific crystallization temperature and modulus retention can be used for fused deposition modeling

Why it is interesting: Additive manufacturing in all its forms has been a steadily growing trend over the last few years. Many different materials have been used in these processes, but the use of thermoplastic polyurethane has proven to be difficult because of its low crystallization rate, broad melting range and challenging melt-viscosity control. According to this application TPU can be used for fused deposition modeling (“3D printing” by extruding molten thermoplastics) when it has a crystallization temperature of about 115°C and retains its shear modulus well with temperature. Examples of such TPUs have a high harblock content (about 50%) and a molar ratio of chain extender to polyol of 2 to about 4, and are prepared from 4,4′-MDI, butandiol and 2000 MW PTMEG polyether or butylene-adipate polyester diols.

Fused Deposition Modeling

Innovation in Polyurethanes

All posts tagged polyether polyol

Flexible PU Foam with Very Low Resilience

Classic PU Patent of the Month: ICI on “High EO – Pure MDI” Flexible Foams (1991)

TPU for 3D Printing

Pages

Categories

Search

Follow this blog via email

Follow Innovation in PU on Twitter