Title: Polyurethane Elastomers Based on TDI Prepolymers Enriched in the 2,6-TDI Isomer Cured with Trimethylene Glycol Di-(para Amino Benzoate)

 Number/Link: US2014/0309397

Applicant/Assignee: Anderson Development

Publication date: 16-10-2014

“Gist”: Elastomers are prepared from TDI containing a high amount of the 2,6 isomer.

Why it is interesting: Commercially available toluene diisocyanate (TDI) usually comes in the 80/20 or the 65/35  2,4/2,6 isomer blend. It is known that higher 2,6 levels result in stiffer hardblocks and a different reaction profile because of the (initially) equal reactivity of the isocyanate groups. According to this invention elastomers prepared from TDI with a 2,6 content of (most preferred) at least 60% results in superior green strength and dimensional stability. High 2,6 TDI-PTMEG prepolymers cured with trimethylene glycol di(p-aminobenzoate) (TGDBA) should even have a superior tear strength and upper hardness limit compared to MDI based elastomers.

TGDBA