Salts of pyromellitic acid, a process for their preparation, and their use
AssigneeHuels Aktiengesellschaft
InventorsRainer Gras, Elmar Wolf
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Abstract
The invention relates to salts of pyromellitic acid which comprise 1 mol of pyromellitic acid and 0.5. to 2 mol of a guanidine of the following composition: ##STR1## in which R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different radicals from the group consisting of hydrogen, alkyl, cycloalkyl and aromatic hydrocarbon residues having 1 to 8 carbon atoms, and R.sup.1 and R.sup.2 and R.sup.3 and R.sup.4 may form a joint ring which may contain an oxygen atom as heteroatom. Also claimed are the preparation of the salts and their use for matt epoxide and hybrid powder coatings.
Claims4
A salt of pyromellitic acid comprising:
- 1 mol of pyromellitic acid;
- and
- 0.5-2 mol of a guanidine of the formula (I):
- ##STR5## wherein R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are each a radical selected from the group consisting of hydrogen, C.sub.1-8 alkyl, C.sub.3-8 cycloalkyl and C.sub.6-8 aromatic hydrocarbon residues, or R.sup.1 and R.sup.2 and R.sup.3 and R.sup.4 may jointly form a ring containing 5 to 7 carbon atoms in which one of the carbon atoms may be substituted with an oxygen atom.
A process for preparing a salt of pyromellitic acid comprising 1 mol of pyromellitic acid and 0.5 to 2 mol of a guanidine of the formula (I):
- ##STR6## wherein R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are each a radical selected from the group consisting of hydrogen, C.sub.1-8 alkyl, C.sub.3-8 cycloalkyl and C.sub.6-8 aromatic hydrocarbon residues, or R.sup.1 and R.sup.2 and R.sup.3 and R.sup.4 may jointly form a ring containing 3 to 8 carbon atoms in which one of the carbon atoms may be substituted with an oxygen atom;
- comprising the steps of:
- reacting 1 mol of pyromellitic acid with 0.5-2 mol of a guanidine in H.sub.2 O, ethanol or a mixture thereof at 50-100.degree. C.;
- and
- after reaction has finished, isolating said guandine salt of pyromellitic acid from the solvent.
Dependencies are inferred from the claim text.