Mannich bases from isolated amine adducts
Mannich bases as curing agents for epoxy resins, characterized in that to prepare the Mannich base an isolated amine adduct is used obtainable by reacting a) an amine containing at least three active amine hydrogens with b) an epoxide compound containing on average one or more than one epoxide group in the molecule, optionally using a solvent, there being an excess of a) relative to reactive groups of components a) and b), and subsequently the adduct formed is isolated from free amines. Curable epoxy resin compositions comprising these Mannich bases are suitable owing to good obtainable surface properties in particular for coating, adhesively bonding and enhancing metallic and mineral substrates, as adhesive and sealant, and for producing mouldings and sheetlike structures.
1 - 11 . (canceled)
12 . A process for producing a Mannich Base comprising the steps of:
1. forming an isolated amine adduct;
2. reacting the isolated amine adduct with an aldehyde component and a phenol component.
13 . The process of claim 12 , wherein the isolated amine adduct is formed by reacting (a) an amine compound containing at least three active amine hydrogens with (b) an epoxide compound, there being an excess of (a) relative to reactive groups of components (a) and (b), and thereafter separating off the excess amine compound to yield an adduct isolated from free amines.
14 . The process of claim 13 , wherein the epoxide compound is a monofunctional glycidyl ether.
15 . The process of claim 13 , wherein the amine compound is a polyalkylenamine.
16 . The process of claim 15 , wherein the amine compound is a polyethylenepolyamine.
17 . The process of claim 13 , wherein the epoxide compound is added to a 1.5 to 8 molar excess of the amine component.
18 . The process of claim 17 , wherein the epoxide compound is added to a 2 to 3 molar excess of the amine component.
19 . A process for producing a Mannich base comprising the steps of:
1. forming an isolated amine adduct;
2. subject the isolated amine adduct to a transamination reaction with a Mannich base.
20 . The process of claim 19 , wherein the isolated amine adduct is formed by reacting (a) an amine compound containing at least three active amine hydrogens with (b) an epoxide compound, there being an excess of (a) relative to reactive groups of components (a) and (b), and thereafter separating off the excess amine compound to yield an adduct isolated from free amines.
21 . The process of claim 20 , wherein the epoxide compound is a monofunctional glycidyl ether.
22 . The process of claim 20 , wherein the amine compound is a polyalkylenamine.
23 . The process of claim 22 , wherein the amine compound is a polyethylenepolyamine.
24 . The process of claim 20 , wherein the epoxide compound is added to a 1.5 to 8 molar excess of the amine component.
25 . The process of claim 24 , wherein the epoxide compound is added to a 2 to 3 molar excess of the amine component.
26 . The process of claim 19 , wherein the isolated amine adduct is subjected to a transamination reaction with a Mannich base of phenol, formaldehyde and dimethylamine.
27 . The process of claim 26 , wherein the Mannich base is tris(dimethylaminomethyl)phenol.
28 . The process of claim 19 , wherein the transamination reaction has a degree of exchange from 50% to 99%.
29 . The process of claim 28 , wherein the transamination reaction has degree of exchange from 60% to 95%.
30 . The process of claim 28 or claim 29 wherein the Mannich base is trisdimethylaminomethylphenol.
31 . A curable composition comprising:
(a) a Mannich based produced by the process according to claim 1 or claim 19; and
(b) an epoxy resin.