Diamine curing agents for the preparation of polyurethane-urea elastomers
AssigneeCrompton Corporation
InventorsVincent J. Gajewski, Franklin H. Barrows
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Abstract
Alkanediol ortho- and meta-diamino benzoates are prepared by reacting either ortho- or meta-amino benzoic acid esters with an alkanediol in the presence of a transesterification catalyst. The ortho-diamine may alternatively be prepared by reacting isatoic anhydride with the alkanediol. These alkanediol ortho- and meta-diamino benzoates are useful in the curing of urethane prepolymers to produce novel polyurethane urea elastomers.
Claims18
A process for the direct preparation of alkanediol ortho- or meta-diaminobenzoates comprising transesterifying an alkyl ortho- or meta-aminobenzoate with an alkanediol in the presence of a transesterification catalyst.
A process for the preparation of alkanediol ortho- or meta-diaminobenzoates comprising reacting an ortho- or para-aminobenzoic acid ester with an alkanediol in the presence of a transesterification catalyst, according to one of the following equations:
- 4
- wherein:
- R1 is an alkyl group from 1 to 12 carbon atoms and R2 is an alkylene moiety from 1 to 12 carbon atoms.
A process for the direct preparation of alkanediol ortho-diaminobenzoates comprising esterifying isatoic anhydride with an alkanediol in the presence of an esterification catalyst, wherein the molar ratio of anhydride to alkanediol is at least 2:1.
A polyurethane urea elastomer prepared by curing a urethane prepolymer with an alkanediol ortho- or meta-diaminobenzoate prepared by a process comprising transesterifying an alkyl ortho- or meta-aminobenzoate with an alkanediol in the presence of a transesterification catalyst.
A polyurethane urea elastomer prepared by curing a urethane prepolymer with an alkanediol ortho-diaminobenzoate prepared by a process comprising comprising esterifying isatoic anhydride with an alkanediol in the presence of an esterification catalyst, wherein the molar ratio of anhydride to alkanediol is at least 2:1.
Dependencies are inferred from the claim text.