Curing agents for aqueous epoxy resin dispersions obtained by reaction of an adduct (A) of at least one polyepoxide (A.sub.1) and at least one polyalkylene polyether polyol (A.sub.2), it being possible for the adduct (A) to be modified with a secondary amine (A.sub.3) if appropriate, with I. a reaction product of an amine (B) and an epoxide (C) or II. an amine (B) and subsequent reaction with an epoxide (C), the amount of amine (B) being chosen such that the H atoms on the nitrogen are present in a 2- to 10-fold excess, based on the epoxide groups in (A).
Water dilutable amine curing agents for aqueous epoxy resin dispersions, comprising a combination of an epoxide-amine adduct with an emulsifier, the epoxide-amine adduct being obtainable by reacting a polyepoxide with a reaction product of an amine and an epoxide component or an amine and subsequent reaction with an epoxide component, the amount of amine being chosen such that the number of nitrogen-attached hydrogen atoms the number of epoxide groups by a factor of from 2 to 10, and the emulsifier being obtainable by reacting diepoxides or polyepoxides with compounds that are at least difunctional with respect to epoxides, optionally with compounds D that are monofunctional with respect to epoxides, and with amines G which contain at least one tertiary and at least one primary or at least two secondary amino group(s).
Water-dispersible curing agents for epoxy resins are disclosed which, as a mixture with epoxy resins, have a potlife indication by showing the end of the processing time by a clear increase in viscosity, and which comprise reaction products (ABC) of adducts of aliphatic polyols (A) with a weight-average molar mass of from 200 to 20, 000 g/mol, comprising at least one polyol (A1) having a molar mass of less than 4000 g/mol, and at least one polyol (A2) having a molar mass of more than 4000 g/mol, and at least one epoxide compound (B) having at least two epoxide groups per molecule, and a specific epoxide group content of from 500 to 10 000 mmol/kg, (A1) and (A2) being reacted separately or as a mixture with (B), and then reacting this adduct with one or more polyamines (C) having at least three amine hydrogen atoms and at least one primary amino group per molecule, the ratio of the number of hydroxyl groups of component (A) to the number of epoxide groups of component (B) being 1:3 to 1:10, and the ratio of the number of remaining epoxide groups in the epoxide-polyol adduct to the number of amine hydrogen atoms in polyamines (C) being 1:1.5 to 1:100. The water-dispersible curing agents are useful as curing agents for epoxy resins in two component coating compositions.
A curable composition is described, comprising a) 10 to 90% by weight of at least one, optionally water-dilutable, water-emulsifiable or water-dispersible, epoxy resin having more than one epoxy group in the molecule; b) 90 to 10% by weight of at least one polyamine adduct which predominantly corresponds to the idealised formula (I) and which is prepared from an adduct of formula (A) and a polyamine of formula (XII), wherein the sum of the percentages by weight of components (a) and (b) is always 100%; c) optionally, at least one further aliphatic, cycloaliphatic, aromatic/aliphatic, aromatic or heteroaromatic mono- or polyamine which may optionally be modified by adduction; and d) optionally, at least one customary additive, R.sup.1 and R.sup.2 and also m and n and B being defined in more detail in the description. The novel compositions are used for the preparation of colourants and coatings. ##STR1##
Hardeners for epoxy resins produced by reacting one or more .alpha.,.beta.-unsaturated carboxylic acid esters with one or more aminopolyalkylene oxide compounds, reacting the thus formed intermediate with one or more polyhydroxy compounds, reacting the thus formed intermediate with one or more polyepoxide compounds, and reacting the thus formed intermediate with one or more amines are described. Processes for their production, aqueous dispersions containing the same and methods for their use are also described.
Hardeners for epoxy resins produced by reacting one or more .alpha.,.beta.-unsaturated carboxylic acid esters with one or more hydroxy compounds, reacting the thus formed intermediate with one or more aminopolyalkylene oxide compounds, reacting the thus formed intermediate with one or more polyepoxide compounds, and reacting the thus formed intermediate with one or more amines are described. Processes for their production, aqueous dispersions containing the same and methods for their use are also described.
