Abstract:
A selif-emulsifying epoxy resin (A), prepared from proportions by mass of(A-1) from 50 to 95% of one or more epoxide compounds having at least two epoxide groups per molecule and an epoxide group content of from 300 to 11,200 mmol/kg;(A-2) from 5 to 50% of an aromatic polyol;(A-3) from 0 to 25% of modifying compounds having at least two epoxide-reactive groups;(A-4) from 5 to 25% of an emulsifying product of the condensation of(A-4-a) an aliphatic polyol having a weight-average molar mass M.sub.W of from 200 to 20,000 g/mol and(A-4-b) an epoxide compound having at least two epoxide groups per molecule and an epoxide group content of from 500 to 10,000 mmol/kg,whereby the ratio of the number of OH groups to the number of EP groups is from 1:2 to 1:10 and the epoxide group content of these condensation products (A-4) is between 100 and 6700 mmol/kg.
Abstract:
An emulsifier composition for water-dilutable epoxy resins comprise condensation products of an aliphatic polyol component having a weight-average molar mass (M.sub.w) of from 200 to 20,000 g/mol, where a mass fraction of at least 5%, has a weight-average molar mass (M.sub.w) of at least 4000 g/mol, and an epoxide component having of at least one epoxide compound having at least two epoxide groups per molecule and an epoxide group content of from 500 to 10,000 mmol/kg, the ratio of the number of hydroxyl groups to that of the epoxide groups (OH):(EP) being from 1:3.51 to 1:10. When the emulsifier is used for the preparation of aqueous epoxy resin systems, the end of the pot life is indicated by a sharp rise in viscosity.
Abstract:
The invention relates to a stable epoxy resin dispersions and also a process for the preparation thereof and the use thereof, in particular for coatings. The epoxy resin dispersions which are remarkable, in particular, for good storage stability with a low content of organic solvents at the same time and little tendency to skin formation and yield coatings with good surface properties, contain, in addition to water, optionally small quantities of organic solvents and also optionally usual additives, as an essential constituent a condensation product of(a) 50 to 80% by weight of an epoxy compound containing at least two epoxy groups per molecule and having an epoxy equivalent to of 100 to 2,000.(b) 35 to 17% by weight of an aromatic polyol and(c) 15 to 3% by weight of a condensation product of an aliphatic polyol with a molecular weight (Mw) of 200 to 20,000, an epoxy compound containing at least two epoxy groups per molecule and having an epoxy equivalent of 100 to 2,000, and of a mono- and/or polyisocyanate, the equivalent ratio of the OH groups to the epoxy groups being 1:0.85 to 1:3.5, the quantity of mono- and/or polyisocyanate being 0.05 to 5% by weight, referred to the quantity of aliphatic polyol and epoxy compound, and the epoxy equivalent of said condensation product being between 200 and at least 50,000.
Abstract:
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, withI. a reaction product of an amine (B) and an epoxide (C)orII. 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).
Abstract:
A process for the preparation of aqueous epoxy resin dispersions comprising(1) 20 to 75% by weight, based on the total dispersion, of an epoxy resin constituting a condensation product ofa) epoxy compounds having at least one epoxy group per molecule and an epoxide equivalent weight of 90 to 3000 g/mol, andb) aromatic polyols;(2) 3 to 20% by weight, based on the total dispersion, of an emulsifier comprisinga) a condensation product of an aliphatic polyol and an epoxy compound having at least two epoxy groups per molecule and an epoxide equivalent weight of 90 to 3000 g/mol, the equivalent ratio of the OH groups to the epoxy groups being 1:0.85 to 1:1.5 and the epoxide equivalent weight of this condensation product being between 5000 and 400,000 g/mol,b) an organic solvent, andc) water;(3) up to 10% by weight, based on the total dispersion, of organic solvents; and(4) water in an amount to make up to 100% by weight, which comprises stirring the epoxy resin (1) firstly with the emulsifier (2) and, if appropriate, organic solvents corresponding to (3), and then with water.
Abstract:
Aqueous epoxy resin dispersion comprising (A) an epoxy resin which is a condensation product of (A-1) from 50 to 95% by weight, preferably from 55 to 85% by weight, of one or more epoxide compounds having at least two epoxide groups per molecule and an epoxide equivalent mass of from 100 to 2000 g/mol, (A-2) from 5 to 50% by weight, preferably from 15 to 45% by weight, of an aromatic polyol; and (A-3) from 0 to 25% by weight, preferably from 0 to 10% by weight, of modifying compounds containing at least two epoxide-reactive groups; (B) a dispersant comprising (B-1) a condensation product of a polyol having a weight-average molecular mass (M.sub.w) of from 200 to 20,000 g/mol and an epoxide compound having on average at least two epoxide groups per molecule and an epoxide equivalent mass of from 100 to 10,000 g/mol, and (B-2) if desired other surfactants, preferably nonionic surfactants; (C) a polymer, prepared in this dispersion, of ethylenically unsaturated monomers which are capable of free-radical polymerization or copolymerization; (D) a curing agent for the epoxy resin (A); and (E) if desired, conventional additives and catalysts. These aqueous epoxy resin dispersions are suitable for the production of coatings, in particular for interior coatings of cans for beverages and preserves.
Abstract:
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, withI. a reaction product of an amine (B) and an epoxide (C)orII. 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).
Abstract:
Aqueous epoxy resin dispersions containing(A) an epoxy resin which is a condensation product of one or more epoxy compound(s), of an aromatic polyol and, if used, of a modifying compound having at least two groups which are reactive with epoxides,(B) a dispersing agent in the form of a condensation product of an aliphatic polyol and an epoxy compound, the equivalent ratio of the OH groups to the epoxy groups being 1:0.8 to 1:3.5,(C) a carboxyl-containing or -releasing curing agent for the epoxy resin comprising one or more carboxyl-containing compound(s), at least one of these compounds having a functionality of at least three carboxyl groups per molecule, and(D) if desired customary additives, components (A), (B) and (C) being used in such amounts by weight that the equivalent ratio of the epoxy groups of component (A) capable of reacting to the carboxyl groups of component (B) is at least 1:0.5.