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EC number: 931-288-4 | CAS number: -
Phototransformation in air
Administrative data
Link to relevant study record(s)
Description of key information
The calculated atmospheric oxidation rate constant of 1,3-Diazetidine-2,4-dione, 1,3-bis(6-isocyanatohexyl), the main constituent of HDI Uretdion (n = 2) is 25.0 * E-12cm3/(molecule *sec) and its atmospheric half-life is 15.4 hrs at 25 °C. The value is a result of a QSAR estimation (Currenta, 2014 c).
The atmospheric oxidation rate constant of the corresponding diamine of the main constituent of HDI Uretdion (n=2) is 86.1 * E-12cm3/(molecule *s) and its atmospheric half-life is 4.5 hrs at 25 °C (Currenta, 2014 d).
Key value for chemical safety assessment
- Half-life in air:
- 15.4 h
Additional information
The substance hydrolyses rapidly with a half-life of far less than 24 hours, approx. 6.1 hours. Therefore, an experimental study with HDI Uretdion is scientifically unjustified. The hydrolysis product is a complex mixture of water-insoluble oligomeric and polymeric ureas and of 1,3-Diazetidine-2,4-dione, 1,3-bis(6-isocyanatohexyl), the main constituent of HDI Uretdion, where the isocyanate groups have been transformed to amino groups.
Although being a more theoretical approach, an ideal structure the "corresponding diamine of HDI Uretdion (n=2) was considered in order to get an estimation on the behaviour of the hydrolysed product in air. For both, the unreacted HDI Uretdion (n=2) as well as for the corresponding diamine of HDI Uretdion (n=2), calculated values with two estimation methods are presented.Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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