All posts tagged chain extender

Polyurethane/Polyurea Elastomers from 2,4′-MDI and MDA

Title: MOLDED POLYURETHANE ELASTOMER PARTS MADE OF DIPHENYLMETHANE DIISOCYANATE-BASED NCO PREPOLYMERS AND METAL SALT COMPLEXES, AND A METHOD FOR PRODUCING SAME

 Number/Link: US2013267655

Applicant/Assignee: Bayer

Publication date: 10-10-2013 (priority PCT/DE)

“Gist”: Molded PU/PUA elastomers are prepared from a 2,4′-MDI based prepolymer cured with blocked MDA

Why it is interesting: A prepolymer with an NCO content between 3 to 7% is prepared from MDI containing more than 97% of the  2,4′ isomer together with a diol with an OH value of about 100.  (e.g a PTMEG or a polycaprolacton).  The prepolymer is then cured with a salt-complexed diphenylmethanediamine (“blocked MDA”). Because of it’s relatively low viscosity and long potlife the system allows for the production of thick-walled, bubble-free molded elastomers.  Probably because there is less premature polyurea phase separation (due the 2,4′-MDI) the system cures homogeneously.

4,4'-MDA

4,4′-MDA

Leave a comment
by Gerhard Bleys on October 15, 2013  •  Permalink
Posted in Adhesives-Coatings, Elastomers, Isocyanates and Prepolymers
Tagged , , , , ,

Posted by Gerhard Bleys on October 15, 2013

https://purpatents.com/2013/10/15/polyurethanepolyurea-elastomers-from-24-mdi-and-mda/

Polyurethane Prepregs prepared with Isosorbide

Title: STORAGE-STABLE POLYURETHANE-PREPREGS AND FIBRE COMPOSITE COMPONENTS PRODUCED THEREFROM

 Number/Link: WO2013/139704

Applicant/Assignee: Bayer

Publication date: 26-09-2013

“Gist”: Polyurethane matrix materials for prepregs with very good storage stability are prepared from an NCO prepolymer together with isosorbide and delayed action catalysts.

Why it is interesting: Resins for “prepregs” (pre-impregnated fibre composites) need to have a low viscosity upon impregnation, a good storage stability and a fast ‘curing’ reaction preferably at a relatively low temperature.  According to this invention all these properties can be met by using a 8-16% NCO prepolymer made from a polyester polyol and  MDI, together with a dianhydrohexitol (preferably isosorbide) as chain extender and a delayed action catalyst (e.g. a blocked amine) which is activated between 50 and 100°C. The resulting prepregs have a storage stability at room temperature of several weeks. Final Tg is said to be 130°C, which is not very high but should suffice for many applications.

Isosorbide

Isosorbide

Leave a comment
by Gerhard Bleys on October 1, 2013  •  Permalink
Posted in composites
Tagged , , , , , , ,

Posted by Gerhard Bleys on October 1, 2013

https://purpatents.com/2013/10/01/polyurethane-prepregs-prepared-with-isosorbide/

Over-Indexed and Crosslinkable Thermoplastic Polyurethane

Title: METHOD FOR MAKING OVER-INDEXED THERMOPLASTIC POLYURETHANE ELASTOMER PRECURSOR AND THERMOPLASTIC POLYURETHANE ELASTOMER MADE FROM THE PRECURSOR

 Patent Number & Link: WO2013/103633

Applicant/Assignee: Nike

Publication date: 11-07-2013

“Gist”: A TPU is produced at an NCO index of about 110 comprising an unsaturated chain extender .  The material can be injection moulded and subsequently cured with moisture and free radical polymerization.

Why it is interesting: A thermoplastic PU ‘precursor’ is prepared by reactive extrusion of  a polyol (e.g. a 2000MW polytetramethylene ether glycol), an unsaturated chain extender (e.g. trimethylolpropane monoallyl ether – TMPME), optional additives and MDI at an NCO index of 110 to 115 (preferred). After drying, the resulting pellets can be injection- or compression moulded and then cured by moisture and by heat or UV radiation. The resulting PU-polyurea is claimed to have improved toughness, durability and ‘scuff resistance’ compared to conventional TPUs.  The material appears to have been developed for the golf ball industry.  Nike has filed at least two related ‘golf ball patents’: WO2013/103673 and WO2013/103669.

TMPME: unsaturated chain extender used in the invention

TMPME: unsaturated chain extender used in the invention

Leave a comment
by Gerhard Bleys on July 16, 2013  •  Permalink
Posted in Elastomers, Isocyanates and Prepolymers, Thermoplastics
Tagged , , , , ,

Posted by Gerhard Bleys on July 16, 2013

https://purpatents.com/2013/07/16/over-indexed-and-crosslinkable-thermoplastic-polyurethane/

« Older Posts
Newer Posts »

  • Pages

  • Categories

  • Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 259 other subscribers

  • Follow Innovation in PU on Twitter