CS246685B1 - Impregnation and insulation sandwich systems - Google Patents

Abstract

The solution concerns impregnation and insulation materials intended for the construction industry. The purpose of the solution is to reduce the penetration of water and aqueous solutions through concrete surfaces by using new flexible and tough materials and thus improve the long-term waterproofing of water management structures. This is not only about reducing water leakage from tanks, but also about reducing contamination and pollution of groundwater. The stated purpose is achieved by a sandwich system combining tough epoxy acrylates with flexible epoxy rubbers. The good properties of the new materials can be used not only in agricultural construction, but also in other construction fields such as industrial buildings, water management structures, repair of concrete defects, tanks, etc.

Description

The invention relates to impregnating and insulating materials, in particular for the building industry, suitable for forming protective coatings and layers preventing water and aqueous solutions from penetrating cement surfaces of tanks, pools, reservoirs, sewers and the like.

Our country does not have large reserves of water. That is why we must manage it well, protect our drinking water resources. Especially in such areas as the South Moravian Region. Long-term watertightness is required not only for sanitary water structures, such as reservoirs, storage tanks, sewage treatment plants and the like, but also for ground tanks, silage pits, swimming pools, digesters, sludge pits and the like.

Hardened concrete can be adversely affected by various chemical influences, either by attacking water, exposure to gases and air, soil and soil minerals, or even chemicals. The attacking waters attack concrete most often. In addition to the concentration of the aggressive components contained in it, its amount is also important. The attacking waters disrupt the concrete by disrupting and leaching the components of the cement, forming new, less solid compounds, or forming insoluble compounds that increase in volume and expand the concrete by expansion. As attacking water we mean carbonic, sulphate and chloride waters, hungry and acid waters.

At first there was an effort to produce waterproof cement plasters. However, their quality depends too much on the quality of the design, since otherwise it often bursts, becomes permeable and requires expensive repairs. Progress was achieved by machine plastering and the use of colloidal mortar. However, the results were not satisfactory, and even sealants such as calcium and alkaline soaps did not provide a solution to the problem, since they only sealed the micropores in the binder, which must itself be dense and impermeable.

In most cases, sealants reduce the mechanical strength of mortars and concretes, so they cannot be used with new concretes and in some environments, concrete with additives will break down sooner than without additives.

That is why bituminous insulation systems have been used for many years. They are an integral part of the building structure and consist of various primers, asphalt sealants, hot applied, or a series of superimposed reinforcing inserts, joined by asphalt coatings and the like. However, at decreasing temperatures they become brittle and lose their adaptability to deformations of the substrate.

Rheological properties, in turn, limit their use to a certain temperature range. Exceeding it is often the cause of many failures. Asphalt bitumens are better than tar bitumen.

In cold weather there is a risk of premature solidification of the resins and thus their poor spreading. If the temperature of the base masonry is lower than +5 ° C, the masonry must be heated, otherwise the cracks in the coating would be rendered worthless. The frost coating is brittle and slightly damaged. Another disadvantage of resins is that they have a constant plastic flow.

Recently, plastics have been increasingly used in the Czech Republic and abroad. They are, for example, polyvinyl chloride films. Their disadvantage is the difficult and often imperfect connection (by gluing, hot air and high frequency heating) and then that the water extracts from the plasticizer film, hardens, bursts, loses its elasticity and leaks. Therefore, they are only suitable as intermediate insulation. Joining metal strips is even more difficult. The use of silicones encounters considerable shrinkage. Conventional epoxy resins have low ductility and cracking during concrete deformation. Polyethylene plates and foils are very chemically resistant, flexible, lightweight, but their connection is imperfect. There are also problems with bonding rubber bands, especially in bends and corners. Moreover, they are difficult to handle due to their large weight. Enamel coatings (polystyrene, epoxy) have a limited service life. Sometimes concrete is protected by fluctuation. All in all, the problem of limiting the ingress of water and aqueous solutions in the construction industry is very complicated and the state of the art does not yet know the full solution.

We have now found that a more flexible impregnation and insulation system with reduced shrinkage and increased durability will provide a combination of tough epoxyacrylates and epoxy rubbers, obtainable in the case of epoxyacrylates by reacting a blend of by weight and e up to 90 (preferably 70 to 80) weight of 370 to 600, up to 40 (preferably 20 to 30) parts of C ₄ to C ₁₀ alkyl acrylates and aliphatic polyamines or aminoamide resins in an amount of 90 to 140% of the theory based on the epoxy and acrylic group content of the mixture, and in the case of epoxy rubbers by the reaction of mixtures consisting of a liquid epoxy elastomer having an average molecular weight of 550 to 1000 and aliphatic polyamines or aminoamide resins in an amount corresponding to 90 to 120% of the theory with respect to the epoxy group content, both at 5 to 40 ° C (preferably 15 and 25 ° C), it being possible to combine both types of materials varying in number and sequence, preferably the lowermost layer of epoxy rubber and the topmost of epoxyacrylate.

The properties of the masses obtained according to the invention can be varied by influencing the polarity density and the topology of the structural network of the mass by changing the quality and quantity of the starting components. By changing the types and proportions of fillers, mechanical and electrical properties (strength, abrasion, surface resistance, etc.) and processability (viscosity, thixotropy) can be influenced. Fillability can also be influenced by the amount of hardener.

The epoxy resins used are prepared by known methods by condensation of epichlorohydrin with bisphenols in an alkaline medium.

Liquid epoxy elastomers are prepared by known procedures from epoxy resins and compounds having an average molecular weight of 170-500 by reaction with polymeric fatty acids or low molecular weight carboxylic polymers having an average molecular weight of 500-4000 and an average carboxyl group content of 1.80-2.07. Typically, a molar ratio of epoxy compound to polymer fatty acid or low molecular weight carboxylic polymer of 1.9 to 5: 1 is used. They often contain reactive diluents, such as aliphatic epoxy resins based on diols.

The amine and polyaminoamide curing agents used according to the invention have amine numbers of 150 to 1800 mg KOH / g and cause curing of the liquid compositions of the invention at temperatures of 0 to 60 ° C, at an amount corresponding to 90 to 140 and theory of reactive group content. In curing, substances that retard or accelerate the chemical reactions of the compounds in a mixture such as phenolic compounds, water, polyols, thioyl, ketones, cyclic ethers and the like can be used. Sometimes it is appropriate to use substances affecting the flow, surface tension and the like.

Common fillers such as graphite, sand, talc, chalk, gypsum, glass flour, diatomaceous earth, ground fireclay, fly ash, cement, corundum and garnet waste, amorphous silica, silica gel, alumina, metal dust, asbestos, polyvinyl chloride powder and other polymers and copolymers, pigments such as zinc oxide and the like.

The epoxy acrylates according to the invention have a resilient and tough character, characterized by a ductility of 10 to 50% at a tensile strength of 30 to 70 MPa and an impact strength of 40 to 90 kJ / m. The epoxy rubbers of the invention have a ductility of 10 to 100% 3 to 40 MPa and represent a buffer layer. Sandwich systems are characterized by excellent adhesion, wear resistance, weathering and temperature and water and oil impermeability. These good properties can be used especially in agricultural construction, repair of swimming pools, concrete tanks and so on.

The protective coatings and layers of the compositions according to the invention are prepared by coating, rolling, spreading, graveling, spraying, laminating and the like. Preferably, the surface is penetrated. Multiple layers of the same and different quality can be combined.

It is important to thoroughly mix all components and apply them so that there are as few air bubbles in the protective coatings and layers as possible. Ensure that no moisture or dirt enters the layers between workflows. This could impair the adhesion of one layer to the other. Cement surfaces must be dry, stiff, slightly rough, free of cement milk, dust and loose particles, free of oil and grease or other impurities that could impair adhesion. If desired, the surface may be sandblasted, flamed, abraded, and the like. Pressure blasting is sometimes useful.

He did

Reactive mixture consisting of 55 wt. parts of epoxy resin having an average molecular weight of 568, 23.5 wt. parts of 2-ethylhexyl acrylate and 7.8 wt. parts of 2,2-iminoethylamine, corresponding to 115% of theory, will give a tough material having a tensile strength of 47 MPa, an elongation at break of 19% and an impact strength of 69 kJ / m @ 2 after curing.

Example 2

Reactive mixture consisting of 100 wt. parts of epoxy resin having an average molecular weight of 435, 6.3 wt. parts of n-butyl acrylate, 18.7 wt. parts of 2-ethylhexyl acrylate and 16.4 wt. parts of tetraethylpentamine, corresponding to 100% of theory, will give a tough and resilient mass having a strength of 70 MPa, an elongation of 9% and an impact strength of 38 kJ / m after curing.

Example 3

Reactive mixture consisting of 69 wt. parts of epoxy resin having an average molecular weight of 570.31 wt. parts by weight of 2-ethylhexyl acrylate, 26 wt. 14 parts by weight of ethylene / vinyl acetate copolymer. parts of triethylenetetramine, after curing, gives a tough and highly adhesive mass having a tensile strength of 55 MPa, an elongation of 10% and an impact strength of 58 kJ / m.

Example 4

Reactive mixture consisting of 100 wt. parts of liquid epoxy elastomers having an epoxy group content of 0.324 mol / 100 g and 13 wt. parts of trimethylhexamethylenediamine will give a tough mass after curing having a tensile strength of 32 MPa and an elongation at break of 15%.

Example 5

Reactive mixture consisting of 100 wt. parts of liquid epoxy elastomers having an epoxy group content of 0.253 mol / 100 g and 10 wt. parts of trimethylhexamethylenediamine will provide, after curing, an elastic mass having a tensile strength of 4 MPa and an elongation at break of 77%.

Claims (1)

Impregnating and insulating sandwich systems suitable for providing protection against the penetration of water and aqueous solutions obtainable in the case of epoxyacrylates by reaction of a mixture consisting by weight of 60 to 90, preferably 70 to 80, parts of an epoxy resin having an average molecular weight of 370 to 600, 10 to 40, preferably 20 to 30, parts to alkyl acrylates and aliphatic polyamines or amiamide resins in an amount of 90 to 140% of theory based on the epoxy and acrylic group content of the mixture, and in the case of epoxy rubbers by mixtures consisting of liquid epoxy elastomers having an average molecular weight of 550 to 1000 and aliphatic polyamines or aminoamide resins in an amount corresponding to 90 to 120% of the theory of epoxide content, both at a temperature of 5 to 40 ° C, preferably 15 to 25 ° C, both of which may be combined %, preferably the lowest layer of epoxy rubber and the highest layer of epoxy acrylates.