Classic PU Patent of the Month: Otto Bayer’s Invention of Polyurethane and Polyurea (1937)

Title: Verfahren zur Herstellung von Polyurethanen bzw. Polyharnstoffen

Number/Link: DE728981  (German)

Applicant/Assignee: I.G.Farbenindustrie

Publication date: 12-11-1942

Gist”: Production of polyurethanes by reacting diisocyanates and compounds containing at least two hydroxyl and/or amine groups.

Why it is interesting: This is the patent that marked the start of the polyurethane industry.   It covers both aromatic and aliphatic diisocyanates, notably NDI, MDI, TDI, HDI etc. The examples cover polyurethane and polyurea fibers and films. It is said that Bayer was trying to copy Nylon 6,6, the structure of which is very similar to a PU based on 1,6 hexanediol and 1,6 hexanediisocyanate.  The patent has only one claim:

“PATENTANSPRUCH:
Verfahren zur Herstellung von Polyurethanen bzw. Polyharnstoffen, dadurch gekennzeichnet, daβ man organische Diisocyanate mit solchen organischen Verbindungen
zur Reaktion bringt, die mindestens 2 Hydroxyl- oder Aminogruppen mit austauschbaren Wasserstoffatomen oder mindestens eine Hydroxylgruppe und mindestens eine Aminogruppe ,der genannten Art enthalten.”

Dr. Otto Bayer (1902-1982)

Dr. Otto Bayer (1902-1982)

Polyurea ‘Nano’-Particles to Improve Properties of Polyurethane Flexible Foams and Elastomers

Title: USE OF POLYUREA NANOPARTICLES AS PERFORMANCE MODIFIERS IN POLYURETHANE MATERIALS

 Number/Link: WO2014/012769

Applicant/Assignee: Huntsman

Publication date: 23-01-2014

Gist”: A dispersion of polyurea particles prepared from 4,4′ MDI, diamine chain extender and a high mole weight monoamine is used to improve mechanical properties of flex foam.

Why it is interesting: Dispersions of polyurea particles with an average diameter of a few hundred nanometer and a Tg>150°C (pref.) can be produced by first reacting a relatively high MW polyether monoamine and a di-isocyanate (optionally dispersed in e.g. polyol) and subsequently adding a diamine chain extender. The dispersion is then used in a flexible foam or elastomer formulation, such that the amount of particles in the material is about 1-5% (w/w). In an example a 2000MW EO/PO monoamine was used together with 4,4′-MDI and a diamine chain extender to produce a particle dispersion in polyol, which was then used in polyurethane formulations. The particles do seem to have a positive effect on mechanical properties, however, the results for flex foam are clouded because of a sharp increase in material density compared to the reference. This density increase may well be due to a cellopening effect as described in WO2007/104623  in which a similar particle dispersion is used.

Polyethermonoamine as used in the invention.

Polyethermonoamine as used in the invention.

Polyurethane Foam Containing Iron Particles for Improved Oil Absorption

Title: ABSORBENT MATERIAL

 Number/Link: WO2014/008554

Applicant/Assignee: Advanced Simplicity Technologies

Publication date: 16-01-2014

Gist”: Incorporation of iron particles improves the oil-absorbing capacity of PU foams.

Why it is interesting: The mineral-oil absorbing capacity of PU foam is well known and documented (see e.g. WO/1995/031402  and WO/1999/005066 ).  Current invention claims that the oil absorbing capacity of the foam can be greatly improved by incorporating inorganic particles, esp. metallic iron or silica. The particle size of the particles is chosen such as to protrude the foam cell walls so that they are exposed inside the foam pores (pref. 50 to 200μm). In an example an MDI-based  foam containing 70% (w/w) of iron powder was shown to absorb about 10g of oil per gram of foam.

Oils Spill at Sea

Oils Spill at Sea

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