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Waterproofing with liquid polyurethane
Introduction
Waterproofing[1] or water-repellent are substances or chemical compounds that aim to stop water, preventing its passage,[2] and are widely used in the coating of parts and objects that must be kept dry. They work by eliminating or reducing the porosity of the material, filling leaks and isolating moisture from the environment. They can have natural or synthetic, organic or inorganic origin. Among the natural ones, castor oil stands out and, among the synthetic ones, petroleum, chapopote, asphalt or tar.[3].
Chemical waterproofing[4] as we know it today was invented in Switzerland for use in the Gotthard tunnel in 1910 by Swiss inventor and businessman Kaspar Winkler"), who founded what is now Sika AG.[5].
In civil construction, they are used in the insulation of foundations, slabs, roofs, slabs, walls, tanks, swimming pools and cisterns. In this area they are known as water-repellent. In Argentina, this material is called ceresita, due to its popularized brand name.
Composition
A waterproofing sealant can be made with alkylsilicone compounds, such as sodium or potassium methyl, ethyl or propylsiliconeates. These alkali metal alkyl siliconates are used in the form of an aqueous solution.
The amount of alkyl silicones to be used is generally below 3 parts by weight per 100 parts by weight of waterproofing sealant. It is possible to use a single siliconeate or a mixture of at least two or more of the mentioned siliconetes in the waterproofing sealant composition. The preferred amount of siliconetes to be used is 1.4 to 1.9 parts by weight per 100 parts by weight of waterproofing solution.
The most frequently used polymers for this type of compounds are polyurethane emulsions/dispersions, alkali-stabilized acrylic resins, vinyls and their copolymers. The preferred polymer emulsion/dispersion are polyurethanes. A mixture of two or more of the aforementioned polymer emulsions may be used in the formulation or it may be manufactured with a single polymeric emulsion/dispersion. The amount of parts by weight of total polymer (solids content present in the emulsions/dispersions) used in the formulation is 0.20 to 10 parts/100 parts by weight of insulating waterproofing solution.
The preferred amount of parts by weight of polymer used in the formulation is 1.0 to 3.5 parts/100 parts by weight of sealant waterproofing solution, although the latter will depend on many other conditions. Polyurethane dispersions, emulsions are made from aliphatic and aromatic isocyanates, polyisocyanates, polyols and co-solvents.
Waterproofing with liquid polyurethane
Introduction
Waterproofing[1] or water-repellent are substances or chemical compounds that aim to stop water, preventing its passage,[2] and are widely used in the coating of parts and objects that must be kept dry. They work by eliminating or reducing the porosity of the material, filling leaks and isolating moisture from the environment. They can have natural or synthetic, organic or inorganic origin. Among the natural ones, castor oil stands out and, among the synthetic ones, petroleum, chapopote, asphalt or tar.[3].
Chemical waterproofing[4] as we know it today was invented in Switzerland for use in the Gotthard tunnel in 1910 by Swiss inventor and businessman Kaspar Winkler"), who founded what is now Sika AG.[5].
In civil construction, they are used in the insulation of foundations, slabs, roofs, slabs, walls, tanks, swimming pools and cisterns. In this area they are known as water-repellent. In Argentina, this material is called ceresita, due to its popularized brand name.
Composition
A waterproofing sealant can be made with alkylsilicone compounds, such as sodium or potassium methyl, ethyl or propylsiliconeates. These alkali metal alkyl siliconates are used in the form of an aqueous solution.
The amount of alkyl silicones to be used is generally below 3 parts by weight per 100 parts by weight of waterproofing sealant. It is possible to use a single siliconeate or a mixture of at least two or more of the mentioned siliconetes in the waterproofing sealant composition. The preferred amount of siliconetes to be used is 1.4 to 1.9 parts by weight per 100 parts by weight of waterproofing solution.
The most frequently used polymers for this type of compounds are polyurethane emulsions/dispersions, alkali-stabilized acrylic resins, vinyls and their copolymers. The preferred polymer emulsion/dispersion are polyurethanes. A mixture of two or more of the aforementioned polymer emulsions may be used in the formulation or it may be manufactured with a single polymeric emulsion/dispersion. The amount of parts by weight of total polymer (solids content present in the emulsions/dispersions) used in the formulation is 0.20 to 10 parts/100 parts by weight of insulating waterproofing solution.
Toluene diisocyanate (TDI), diphenylmethane 4,4'-diisocyanate (MDI), hexamethylene diisocyanate (IDH), isophorone diisocyanate (IPDI). are used to make these dispersions/emulsions. Polyisooyanates can be based on the TDI, MDI and IPDI.
The polyols are polyethers, polyesters, acrylic-based polyols, polycarbonate-based polyols and the like. Examples of co-solvents are hydrocarbon solvents, such as toluene, N-methyl-2-pyrrolidone, dimethyl formamide (DMF) and the like. Alkaline silicates are those of sodium and potassium. The preferred one is sodium silicate represented by the formula:.
NaO x SiO where 2.0 < x < 3.2.
The preferred amount of a silicate to be used is 0.001 to 1.0 parts by weight per 100 parts by weight of the waterproofing sealant.
The most common solvents are ethylene glycol, diethylene glycol, methanol, ethanol, n-propanol, isopropanol, n-butanol and iso-butanol. One or a mixture of two or more of the diluents may be used. The preferred amount of thinners to be used is 0 to 5 parts by weight per 100 parts by weight of waterproofing sealant. The additives are surfactants, wetting agents, antifoams, biocides, etc. The preferred amount of each of these additives that can be used is 0.005 to 2 parts by weight per 100 parts by weight of the waterproofing sealant.
Other ingredients, such as pigments, plasticizers, ultraviolet inhibitors, antioxidants and the like may also be used in conventional amounts.
Waterproofing agents can be used in domestic and construction waterproofing processes, such as facades, roofs, roofs, etc.
References
[1] ↑ ASALE, RAE-. «impermeabilizante | Diccionario de la lengua española». «Diccionario de la lengua española» - Edición del Tricentenario. Consultado el 15 de enero de 2023.: https://dle.rae.es/impermeabilizante
The preferred amount of parts by weight of polymer used in the formulation is 1.0 to 3.5 parts/100 parts by weight of sealant waterproofing solution, although the latter will depend on many other conditions. Polyurethane dispersions, emulsions are made from aliphatic and aromatic isocyanates, polyisocyanates, polyols and co-solvents.
Toluene diisocyanate (TDI), diphenylmethane 4,4'-diisocyanate (MDI), hexamethylene diisocyanate (IDH), isophorone diisocyanate (IPDI). are used to make these dispersions/emulsions. Polyisooyanates can be based on the TDI, MDI and IPDI.
The polyols are polyethers, polyesters, acrylic-based polyols, polycarbonate-based polyols and the like. Examples of co-solvents are hydrocarbon solvents, such as toluene, N-methyl-2-pyrrolidone, dimethyl formamide (DMF) and the like. Alkaline silicates are those of sodium and potassium. The preferred one is sodium silicate represented by the formula:.
NaO x SiO where 2.0 < x < 3.2.
The preferred amount of a silicate to be used is 0.001 to 1.0 parts by weight per 100 parts by weight of the waterproofing sealant.
The most common solvents are ethylene glycol, diethylene glycol, methanol, ethanol, n-propanol, isopropanol, n-butanol and iso-butanol. One or a mixture of two or more of the diluents may be used. The preferred amount of thinners to be used is 0 to 5 parts by weight per 100 parts by weight of waterproofing sealant. The additives are surfactants, wetting agents, antifoams, biocides, etc. The preferred amount of each of these additives that can be used is 0.005 to 2 parts by weight per 100 parts by weight of the waterproofing sealant.
Other ingredients, such as pigments, plasticizers, ultraviolet inhibitors, antioxidants and the like may also be used in conventional amounts.
Waterproofing agents can be used in domestic and construction waterproofing processes, such as facades, roofs, roofs, etc.
References
[1] ↑ ASALE, RAE-. «impermeabilizante | Diccionario de la lengua española». «Diccionario de la lengua española» - Edición del Tricentenario. Consultado el 15 de enero de 2023.: https://dle.rae.es/impermeabilizante