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AssigneeCiba-Geigy Corporation
InventorsFriedrich Lohse, Friedrich Stockinger, Sameer H. Eldin
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N-Substituted aspartic acid monoesters of the formula ##STR1## wherein for example R.sub.1 is an alkyl group having 1 to 12 C atoms, a cyclohexyl, phenyl, tolyl or benzyl group, R.sub.2 is an alkyl group having 3 or 4 C atoms, or a cyclohexyl, phenyl, tolyl or methoxyphenyl group, and x is 2 or 3, are obtained by adding, by means of an addition reaction, to 1 mol of a maleic acid monoester of the formula ##STR2## 1 mol of an amine of the formula H.sub.2 N--(CH.sub.2 ).sub.x NH--R.sub.2 in the presence of a tertiary amine. The novel N-substituted aspartic acid monoesters are valuable curing agents for epoxide resins, and are particularly suitable for producing storage-stable B-stage resins.
An N-substituted aspartic acid monoester of the formula I ##STR12## wherein R.sub.1 is an alkyl group which has 1 to 12 C atoms and which optionally contains ether oxygen atoms, or it is a cyclohexyl, phenyl, tolyl or benzyl group, R.sub.2 is an alkyl group having 3 or 4 C atoms, or it is a cyclohexyl, phenyl, tolyl or methoxyphenyl group, and x is the number 2 or 3.
Dependencies are inferred from the claim text.