Hyperbranched polyaspartate esters and a process for their preparation
AssigneeBayer Aktiengesellschaft
InventorsPhilip E. Yeske, Lyuba K. Gindin, Douglas A. Wicks, E. Haakan Jonsson
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Abstract
The present invention relates to hyperbranched polyaspartate esters containing repeating structural units corresponding to the formula I and/or II ##STR1## The present invention also relates to a process for the preparation of these hyperbranched polyaspartate esters by self condensing, via a transesterification reaction, at least a portion of the hydroxy and ester groups of the hydroxy aspartates corresponding to the above formula at a temperature of 60.degree. to 240.degree. C. to form hyperbranched polyaspartate esters and eliminating alcohols having the formula R.sub.1 --OH and/or R.sub.2 --OH.
Claims9
A hyperbranched polyaspartate ester containing repeating structural units corresponding to the formula I ##STR5## wherein R.sub.3 and R.sub.4 may be identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100.degree. C. or less, and
- R.sub.5 represents a hydrocarbon radical containing at least two carbons,
- n has a value of 1 to 3 and
- x has a value of 1 to 3, but cannot be greater than n.
A process for the preparation of hyperbranched polyaspartate esters which comprises self condensing, via a transesterification reaction, at least a portion of the hydroxy and ester groups of a hydroxy aspartate corresponding to the formula ##STR6## wherein R.sub.1 and R.sub.2 may be identical or different and represent organic groups which are inert towards isocyanate groups at a temperature of 100.degree. C. or less,
- R.sub.3 and R.sub.4 may be identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100.degree. C. or less, and
- R.sub.5 represents a hydrocarbon radical containing at least two carbons and
- n has a value of 1 to 3,
- at a temperature of 60.degree. to 240.degree. C. to form hyperbranched polyaspartate esters and eliminating alcohols having the formula R.sub.1 --OH and/or R.sub.2 --OH.
Dependencies are inferred from the claim text.