Polyaldimines
The invention relates to polyaldimines which may be obtained from at least one polyamine (A) with aliphatic primary amino groups and at least one aldehyde (B). Said polyaldimines are odorless as are the aldehydes (B) produced by hydrolysis thereof. The invention further relates to methods for production of said polyaldimines and aldehyde (B) and methods for hydrolysis of the polyaldimine. The use of said polyaldimine in compositions as adhesive, sealant, coating or covering agents is disclosed. Said polyaldimines are characterized in being odorless, rapidly hydrolyzed on contact with water, no detectable odors being generated after hydrolysis thereof and stable to storage with the exclusion of water in compositions which contain components reactive towards amines.
1. A polyaldimine which is obtainable from
at least one polyamine A having aliphatic primary amino groups and
at least one aldehyde B of the formula
where Y 1 and Y 2 either independently of one another are an alkyl, aryl, arylalkyl group, a substituted alkyl, a substituted aryl, an alkyl containing one or more heteroatoms, an aryl containing one or more heteratoms, a substituted alkyl containing one or more heteroatoms, or a substituted aryl containing one or more heteratoms;
or Y 1 and Y 2 are connected to one another to form a carbocyclic or heterocyclic ring which has a ring size of between 5 and 8 atoms; and
R 1 stands either
for a linear or branched alkyl chain having 11 to 30 carbon atoms, with or without at least one heteroatom, or for a singly or multiply unsaturated linear or branched hydrocarbon chain having 11 to 30 carbon atoms;
or for
or for
where R 2 is a linear or branched or cyclic alkylene chain having 2 to 16 carbon atoms, with or without at least one heteroatom, or is a singly or multiply unsaturated linear or branched or cyclic hydrocarbon chain having 2 to 16 carbon atoms, and
R 3 is a linear or branched alkyl chain having 1 to 8 carbon atoms;
wherein the polyaldimine is odorless.
2. The polyaldimine as claimed in claim 1 , wherein the polyamine A having aliphatic primary amino groups is selected from the group consisting of 1,6-hexamethylenediamine, 1,5-diamino-2-methylpentane (MPVD), 1,3-diaminopentane (DAMP), isophoronediamine (IPDA), 2,2,4- and 2,4,4-trimethyihexamethylenediamine, 4-aminomethyl- 1,8-octanediamine, 1,3- and 1,4-xylylenediamine, 1,3- and 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, 3 (4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6 ]decane, 1,2-, 1,3- and 1,4-diaminocyclohexane, polyoxyalkylene polyamines having in theory two or three amino groups, and also mixtures of two or more of the aforementioned polyamines.
3. The polyaldimine as claimed in claim 1 , wherein the aldehyde B used for preparing the polyaldimine is obtainable by means of an esterification reaction of a β-hydroxy aldehyde with a carboxylic acid, the β-hydroxy aldehyde being prepared, in situ if appropriate, from formaldehyde, and/or paraformaldehyde, and from a second aldehyde, this second aldehyde being selected from the group consisting of isobutyraldehyde, 2-methylbutyraldehyde, 2-ethylbutyraldehyde, 2-methylvaleraldehyde, 2-ethylcaproaldehyde, cyclopentanecarboxaldehyde, cyclohexanecarboxaldehyde, 1,2,3,6-tetrahydrobenzaldehyde, 2-methyl-3-phenylpropionaldehyde, 2-phenylpropionaldehyde and diphenylacetaldehyde.
4. The polyaldimine as claimed in claim 3 , wherein the carboxylic acid used for preparing the aldehyde B is selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, succinic acid, adipic acid, azelaic acid and sebacic acid.
5. The polyaldimine as claimed in claim 1 , wherein the aldehyde B is present stoichiometrically or in a stoichiometric excess in relation to the primary amino groups of the polyamine A.
6. The polyaldimine as claimed in claim 1 , wherein Y 1 =Y 2 =methyl.
7. A process for preparing a polyaldimine as claimed in claim 1 , comprising reacting an aldehyde B with a polyamine A having aliphatic primary amino groups.
8. The process for preparing a polyaldimine as claimed in claim 7 , further comprising a step of preparing an aldehyde B from a carboxylic acid and a β-hydroxy aldehyde, the β-hydroxy aldehyde being prepared from formaldehyde, and/or paraformaldehyde or oligomeric forms of formaldehyde, and from a second aldehyde.
9. The process for preparing a polyaldimine as claimed in claim 7 , further comprising a step of preparing an aldehyde B from a carboxylic acid and 3-hydroxypivalaldehyde, 3-hydroxypivalaldehyde being prepared from formaldehyde, and/or paraformaldehyde, and from isobutyraldehyde.
10. The process for preparing a polyaldimine as claimed in claim 7 , wherein no solvents are used during the preparation of the polyaldimine and/or of the aldehyde.
11. A process for hydrolysis of a polyaldimine as claimed in claim 1 comprising bringing the polyaldimine into contact with water in the gaseous aggregate state whereby aldehyde B is released.
12. A hydrolysis process characterized in that a polyaldimine as claimed in claim 1 is brought into contact with water in the form of a water-containing component or a water-releasing component, and aldehyde B is released.
13. The hydrolysis process as claimed in claim 11 , wherein the polyaldimine is present in a composition which comprises components that are reactive toward amines.
14. The polyaldimine as claimed in claim 1 , characterized in that R 1 in the aldehyde B is a linear or branched alkyl chain having 17 to 30 carbon atoms.