CS260720B1 - Polyaminoacrylate hardeners for epoxy water systems - Google Patents

Abstract

The present invention relates to polyaminacrylate hardeners particularly useful for epoxy dispersion mastics, plastics and paints. The hardeners can be prepared at 0 ° C to 60 ° C by mixing 20 to 40% aqueous dispersion copolymers based on acrylic acid and / or methacrylic, alkyl esters of these acids with the number of carbon atoms in the alkyl group 2 to 8 and vinyl monomers, reaction product prepared from condensate aldehydes having carbon numbers of 1 to 7 with aliphatic and / or cycloaliphatic amines having carbon numbers of 2 to 19 and nitrogen atoms 2 to 9 in molar ratio 1: 0.8 to 1.2 with optional contents up to 20% by weight of water and phenols and its alkyl derivatives added per mole of amine at a molar ratio of 0.6 to 1.5, optionally polyamines the number of nitrogen atoms mentioned above and carbon and with the optional addition of water.

Description

The present invention relates to novel polyaminacrylate hardeners suitable for epoxy aqueous systems, in particular epoxy dispersion sealants, pastes and coatings having surfactant and stabilizer properties.

Recently, epoxy aqueous dispersions have been increasingly used in the field of surface treatment. These include: • preparation of sealants, plastics and paints. The reason for the increasing demand for these dispersion systems is primarily to solve the environmental problems associated with the use of similar solvent systems. The hardeners used to cure aqueous dispersions of epoxy resins are usually water soluble or at least readily dispersible. More preferred are types having simultaneous action of surfactants and dispersion stabilizers and allowing the preparation of aqueous dispersions just prior to application simply by mixing the mixture. Hardeners based on modified aliphatic polyamides with the addition of surfactants are used to cure the aqueous epoxy dispersions, but the dispersions formed do not have sufficient stability and the films have increased. water absorption (U.S. Pat. No. 2,739,219, 2,934,485, Japanese Pat. 5 2019 729, 5 4008 635 j. Amino amides based on organic acid amides optionally modified with acrylate or acrylate maleate copolymers (Belg. Pat. 840 427, British Pat. No. 2,002,529, Japanese Pat. No. 5,205,673}, in addition to hardeners, have surfactant effects, but often cause haze formation and hardness reduction.Aminoamide compositions can only be prepared by vigorous dispersion, with some amino amides being miscible with water.

The foregoing drawbacks are substantially eliminated by the present invention, which are based on aqueous polyaminacrylate hardeners for epoxy systems, in particular for the preparation of dispersion sealants, plastics and paints.

These hardeners are obtainable by mixing at 0 to 60 ° C with 100 wt. % of a 20 to 40% aqueous dispersion of copolymers based on 10 to 30 wt. % acrylic and / or methacrylic acid, 20 to 60 wt. % alkyl esters of these acids having 2 to 8 and 20 to 55 wt. 5 to 40 wt. parts of the reaction product prepared from a condensate of aldehydes having a carbon number of 1 to 7 with aliphatic and / or cycloaliphatic, amines with a number of carbon atoms of 2 to 19 and nitrogen atoms of 2 to 9 in a molar ratio of 1: 0.8 to 1.2 with up to 20 wt. water and phenol or its alkyl derivatives added per 1 mol. amine in a molar ratio of 0.6 to 1.5, optionally up to 10 wt. parts of polyamines having the above number of nitrogen and carbon atoms and up to 30 wt. parts of water.

The hardeners according to the invention have some advantages over the known types of hardeners for aqueous epoxy resin systems. The hardeners themselves have film-forming properties, so that they promote the ability to form a film of cured compositions. Another advantage is increased reactivity. They also have the properties of surfactants and thickeners, and their effectiveness is such that it provides stable dispersions by briefly mixing the starting components. By the type of monomers used for the preparation of aqueous dispersions of acrylic copolymers, the properties of these copolymers can be varied in a wide range and thus the final properties of not only hardeners prepared therefrom but also of cured epoxy compositions can be influenced. Compared to the aminoacrylate hardeners disclosed in AO No. 232 169, they have a lower viscosity, which has a favorable effect on processability and further exhibit higher viscosity stability over time.

Among the polyamines, aliphatic, cycloaliphatic and aromatic types are suitable for the preparation of hardeners according to the invention. The most preferred aliphatic polyamines are polyalkylene polyamines, in particular diethylenetriamine, dipropylenetriamine, triethylenetetramine and tetraethylenepentamine. Of the cycloaliphatic amines, for example, methylene-bis (cyclohexylamine), roethylenebis (methylcyclohexylamine and 3,3‘-dimethyl-4,4‘-diaminodicyclohexylmethane, etc.) can be used.

The condensation products used are those based on aliphatic cycloaliphatic and aromatic amines with aldehydes, in particular formaldehyde, acetaldehyde and benzaldehyde, and phenols such as phenol, cresol, xylenol and nonylphenol. The curing rate of the hardeners is controlled by the type of polyamine used, by the amount of condensation product present and by the water content of the hardener.

The invention is further illustrated by the following examples.

He did

100 wt. % of a 25% by weight aqueous dispersion of a copolymer based on 25 wt. % acrylic acid, 25 wt. % ethyl acrylate and Ξ0 wt. Styrene is mixed with 35 wt. parts of the condensate prepared by the reaction of 1 mole of diethylenetriamine and 1 mole of formaldehyde for 1 hour at 50 ° C, after standing, separate water is removed from the condensate and 1 mole of cresol is added at 60 ° C. parts of water. 2 wt. parts of the hardener thus obtained are mixed with 1 part of a diane-based epoxy resin of mol. After homogenization, 2 wt. parts of Portland cement 320. A strong thixotropic mass is obtained, which is suitable for rapid repair of water leaks. After curing, the sealant also has a very good adhesion to the glass. Compared to the previously known types of aqueous epoxy resins, the composition has better adhesion to damp substrates and hardens faster.

Example 2

100 wt. % of a 40% aqueous copolymer dispersion based on 30 wt. styrene, 48 wt. % ethyl acrylate, 2 wt. % butyl acrylate and 20 wt. Acrylic acid is mixed with 10 wt. parts of the condensate prepared by the reaction of 1 mole of dipropylene trihydrin and 0.7 mole of an aqueous solution of formaldehyde and 0.3 mole of benzaldehyde, where, after distilling off the reaction water and water of formoldehyde, 1 mole of xylene are added over 30 minutes. parts of diethylenetriamine. Ke 2 wt. 2 parts by weight of the hardener thus obtained are added. parts of red-brown paste prepared from ferric oxide and mixed well. Ke 4 wt. 1 part by weight of the hardener thus prepared is added. part of epian resin nia dianu base by mol. 380. After thorough mixing, 0.3 wt. water. This gives a paint on concrete or asbestos-cement boards with excellent adhesion and weather resistance.

Example 3

100 wt. % of a 27% aqueous copolymer dispersion based on 15 wt. % methacrylic acid, 50 wt. % ethyl acrylate, 5 wt. % methyl methacrylate, 29 wt. % styrene and 1 wt. vinyl acetate was mixed with 15 wt. parts of condensate prepared by dropping a mixture of 0.8 mol of aqueous formaldehyde solution and 0.2 mol of acetaldehyde to 0.9 mol of triethylenetetramine and 0.1 mol of diaminodiphenylmethane, after cooling, the mixture is dehydrated by distillation and reacted with 1 mol of phenol, thus prepared 6 wt. parts of cyclohexylaminopropylamine. 2 wt. parts of the hardener thus prepared are mixed with 1 wt. Diane based epoxy resin of mol. After thorough homogenization, 3 wt. parts of sand having a particle size of 0.1 to 0.3 mm and 2 wt. parts of power fly ash. The concrete prepared in this way has a pot life of more than 4 hours and can be applied to a damp substrate, for example when treating the bottom of tanks. The advantage of the prepared concrete is very good waterproof and frost resistance.

Claims (1)

Polyiaminacrylate hardeners for epoxy aqueous systems, especially for epoxy dispersion sealants, plastics and paints, prepared by mixing at 0 to 60 ° C 100 parts by weight of a 20 to 40% aqueous dispersion of copolymers based on 10 to 30% by weight of acrylic and / or methacrylic acid, 20 to 60% by weight of an alkyl ester of these acids having 2 to 8 carbon atoms and 20 to 55% by weight of vinyl monomers , V Y M A L E 2 U 5 to 40 parts by weight of a reaction product prepared from a condensate of aldehydes having from 1 to 7 carbon atoms with aliphatic and / or cycloaliphatic amines having from 2 to 19 carbon atoms and from 2 to 9 nitrogen atoms in a molar ratio of 1: 0.8 to 1 2, with an optional content of up to 20 wt. water and phenols and its alkyl derivatives added per mole of amine in a molar ratio of 0.6 to 1.5, optionally up to 10 parts by weight of polyamines having the above-mentioned number of nitrogen and carbon atoms, and up to 30 parts by weight of water.