Soft Ionomeric TPU

Patent Title: SOFTENING THERMOPLASTIC POLYURETHANES USING IONOMER TECHNOLOGY

 Number/Link: US20160347900

Applicant/Assignee: Univ. Akron; Covestro

Publication date: 1-Dec-2016

Gist”: TPU is prepared with ionomeric groups having bulky counter-ions

Why it is interesting: According to this invention a novel type of plasticized thermoplastic polyurethane can be made  by incorporating as chain extender a diol containing an ionic group with a bulky counter ion. It is said that the steric hindrance of the bulky counter ions creates additional free volume that softens the polymer and lowers the melt viscosity. In the examples N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (BES) is used together with bulky alkylammonium cations. The softest TPU shown has a 37 Shore A hardness at 25% hardblock content and 7.6 mole% BES-tetrakis(decyl)ammonium. This accounts for a 35 point hardness decrease compared to an ionomer-free control sample.

N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid

N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid

Reactive Polyurethane Plasticizer

Patent Title: REACTIVE POLYURETHANE PLASTICIZERS AND ADHESIVES MADE THEREFROM

 Number/Link: W02016179131

Applicant/Assignee: Dow

Publication date: 10-11-2016

Gist”: An EO/PO monol is reacted with an excess of 4,4′-MDI

Why it is interesting: The invention is about reactive PU plasticizers which are said to be especially useful for polyurethane moisture curing adhesives used in automotive glass bonding. As opposed to conventional plasticizers they will supposedly not migrate and therefore not degrade adhesive properties over time or cause window fogging. The reactive plasticizers are prepared by reacting a slight excess of 4,4′-MDI with and EO/PO monol of MW between 500 and 2000 Da and an EO:PO ratio of about 1:1, such that the resulting in NCO content is between 0.1 and 1%.  Obviously at such low NCO values most of the MDI will have reacted twice with monol, and the resulting non-reactive plasticizer may (in my opinion) well migrate depending on the composition of both monol and adhesive.

4,4'-MDI

4,4′-MDI

 

Polyurethane-Acrylate Plastisol

Patent Title: ACRYLIC-URETHANE IPN PLASTISOL

 Number/Link: US2016/0152857

Applicant/Assignee: Polyone

Publication date: 2-06-2016

Gist”: Plastisols from blocked-iso grafted acrylate in plasticizer

Why it is interesting:
Conventional plastisols are suspensions of PVC particles in a (usuallly phthalate-) plasticizer. The suspension can be cured by heating, which results in a plasticized elastomer.  Plastisols are used for coatings of e.g. car underbodies and for ‘screen printing’ of textiles. According to this invention a non-PVC plastisol can be produced by dispersing core-shell acrylate polymer particles (Mn between 300,000 and 1,000,000) with blocked isocyanate groups grafted to the backbone into a plasticizer, preferably into dioctylphthalate, together with a latent amine crosslinker like adipic dihydrazide. No information is given about the blocking agent but the plastisol is said to cure at 130-170°C and be especially suited for textile printing.

Adipic dihydrazide

Adipic dihydrazide

Carbon-Black Reinforced Polyurethane Tires

Patent Title: TIRE WITH CARBON BLACK REINFORCED POLYURETHANE 

 Number/Link: US20160060420

Applicant/Assignee: Goodyear

Publication date: 3-03-2016

Gist”: Dried, pulverized C-black is used in cast elastomer

Why it is interesting: According to this invention cast polyurethanes with properties useful for tire production can be made by incorporating 2-4% (w/w) of carbon black, pulverized to an average particle size of 5-10 μm. The carbon black is dispersed in the polyol component together with molecular sieves to absorb the water inherently present in carbon black.  It is said that removing the water allows the carbon black to react with an excess of isocyanate present, thereby greatly improving its reinforcing characteristics. Although not mentioned in the text I assume that the tires are intended for low-speed vehicles only.

GoodYear Tire

GoodYear Tire

Polyurethane Elastomers containing Polyrotaxanes

Title: CAST-MOLDED HEAT-CURABLE POLYURETHANE ELASTOMER

 Number/Link:  WO2015/159875  (Japanese)

Applicant/Assignee: UBE

Publication date: 22-10-2015

Gist”: 1-10% of a polyrotaxane is incorporated in a hot cast PU elastomer system

Why it is interesting: Polyrotaxanes are molecular systems consisting of a linear polymer which is “threated” through a number of ring-shaped molecules. The rings are prevented from ‘sliding off’ by blocking-molecules at both ends of the “thread”. In this invention polyrotaxanes based on a polycaprolactone thread and cyclodextrin rings (pref.) are incorporated in hot cast elastomer systems in amounts of 1-10% (w/w). Because cyclodextrin rings contain hydroxyl groups they react with the isocyanate incorporating the polyrotaxane in the PU polymer. The systems are said to have processing and property advantages for specific elastomer applications, in this case printer rollers – if I understand the machine translation correctly.

Schematic presentation of a polyrotaxane

Schematic presentation of a polyrotaxane