CH659813A5 - Process for protecting the surfaces of articles made of stone, masonry or concrete - Google Patents

Abstract

The stone, masonry or concrete surfaces are treated in four successive operations by impregnation with a two-component curable resin, laying of a layer of glass fibres, impregnation of the glass fibres with the curable resin and, after drying of the layers, application of a protective resin layer.

Description

** ATTENTION ** start of the DESC field may contain end of CLMS **.

CLAIMS 1. A method for protecting the surfaces of stone, masonry or concrete objects, characterized in that the surfaces are treated in four successive operations comprising a) impregnating the surfaces to be protected with a mixture of resin with two components comprising a hardenable resin and a hard curler; b) immediately or after a drying time of the impregnated surface gnate, cover with a layer of glass fiber mat; c) immediate impregnation of the glass fiber layer with a resin mixture identical to that of operation a), and d) after a drying time between 5 hours and a week, the coating wise with a protective resin layer.

2. Method according to claim 1, characterized in that the curable resin is an epoxy resin.

3. Method according to claim 1, characterized in that the curable resin is an unsaturated polyester resin and the hardener is a peroxide compound.

4. Method according to claim 3, characterized in that the two-component resin mixture contains, as an additional component, an accelerating siccative.

5. Method according to one of claims 1 to 4, characterized in that the protective resin is an isophthalic resin flexibilized internally, to which is added a hardener.

6. Method according to claim 5, characterized in that the protective resin contains, as an additional component, an accelerating siccative.

The surfaces of buildings made of stone, masonry and concrete, which are exposed to the free atmosphere are subject to corrosion, which, after a more or less long period of time, damages the surface and can be followed by total destruction of the building. It is above all the pollution caused by industry, automobile exhaust gases and heaters that are responsible for the presence in the atmosphere of acidic substances such as sulfur dioxide or nitric oxides. These substances, which corrode surfaces, are especially harmful in the presence of water, that is to say in the form of rain, snow or acid fog. Other damage, especially on road constructions, is caused by the products used for thawing, such as common salt or calcium chloride.

As the concentration of pollutants has increased significantly in recent years, damage to buildings has become a problem of primary importance. A particularly feared problem is the destruction of reinforced concrete. Under the influence of corrosive substances, the iron incorporated in the concrete begins to rust. The formation of rust is accompanied by swelling which forces the concrete and causes the formation of cracks. These slots facilitate access to the glowing fittings. The consequence is a chain reaction, which in a short time can lead to total destruction.

Countermeasures which aim to prevent or mitigate these effects are known. On the one hand, attempts have been made to impregnate the surfaces with hydrophobic substances such as, for example, silicones. Such protection is only temporary and difficult to monitor. Other measures include painting, for example with products based on chlorinated rubber. The durability of these layers of paint is also limited and requires regular renewal. Especially if surfaces are subject to abrasion, like those of road constructions, protection with layers of paint poses problems.

The object of the present invention is a method for protecting the surfaces of buildings made of stone, masonry and concrete, which, in comparison with known methods, has much safer and lasting effects. The protective layers according to the invention are absolute waterproof and have a high degree of resistance against attack than chemical and mechanical abrasion. Since they can equal be applied to wood, it has the advantage of being able to protect continuously manage masonry or concrete surfaces, which include take wooden elements.

The method according to the invention consists in a treatment of the surface by a series of four successive operations including impregnating the surfaces to be protected with a mixture of resin two components comprising a hardenable resin and a harden followed immediately or after a drying time of the impregnated surface, of a covering with a layer of fibers of glass mat, then an immediate impregnation of the layer of glass fibers by a mixture of resin identical to that of the pre first operation and finally, after a drying time between 5 hours and a week, coating with a layer of professional resin cover, which may also consist of a hardenable resin two components, specially adapted to the requirements of such a layer, that is to say with a high degree of chemical resistance and mé canic.

As suitable two-component curable resins for the first and third operation, for example, epoxy resins or, preferably, unsaturated polyester resins.

As hardeners for the latter, gold peroxides are used ganiques such as for example ketone peroxides. By adding additionally accelerators such as siccatives based on cobalt, you can vary the pot life and the speed of hardening. The viscosity of the resin must agree with the mode of application: room temperature, good penetration into the pores of the support and complete impregnation of the glass fibers must be insured. In the first operation, we apply between 400 and 600 grams of resin for a square meter of surface. The amount necessary is determined by the character of the surface, its roughness and its porosity. The amount of accelerators used is determined by the pot life appropriate for the kind of work in question and also by room temperature.

Glass fibers are usually used in the form of a mat woven or, preferably, nonwoven. Depending on the desired thickness, which can vary between 400 and 1200 grams per square meter, we apply one or more layers. The amount of resin for the third operation varies according to the thickness of the fiber layer. In any case, complete impregnation and covering of glass fibers must be insured.

As protective layers (operation 4), use is preferably made of two-component resins which are internally flexible, such as, for example, phthalic acid resins or isophthalic containing styrene.

Example A concrete surface comprising 5 square meters is well cleaned and dried and then, according to the invention, subjected to the following treatment: 1. Apply the mixture of 1000 g of POLYLITE 8526 "polyester resin 20 g MEKP 502 HARDENER) 2 g C3 ACCELERATOR The pot life of this mixture is limited to approximately 10 minutes; it is therefore necessary to terminate the application in this space of time.

2. A layer of glass fiber in non-woven mats with a thickness of 600 grams per square meter is laid on the surface.

The layer is applied immediately after the impregnation of the support or a few hours later.

3. The layer of glass fibers is impregnated with the same resin mixture as that used for operation 1 above. Naturally, this mixture must be freshly prepared. About 1400 grams of the mixture per square meter is applied by brush or roller.

4. A protective layer comprising a mixture of

1000 g of TOPCOAT H 10004 'resin 20 g of MEKP 502 'HARDENER and 2 g of ACCELERATOR C3, is applied to the surface with a thickness of 500 to 600 g per square meter. Before applying this final layer, it will be necessary to harden and dry the previous layer for at least 5 hours. Drying times up to a full week are permissible.

All these products are produced and sold by Reichhold Chemie AG, Hausen a.A .. Switzerland.

"Polyester resin based on tetrahydrophthalic acid containing 33 to 35% of styrene. Viscosity at 20 C: 1200 to 1400 mPas.

50% methyl ethyl ketone peroxide solution.

 "Solution of cobalt octoate in styrene.

 4> Resin based on isophthalic acid, flexibilized internally.

Claims (3)

1. A method for protecting the surfaces of stone, masonry or concrete objects, characterized in that the surfaces are treated in four successive operations comprising a) impregnating the surfaces to be protected with a mixture of resin with two components comprising a hardenable resin and a hard curler; b) immediately or after a drying time of the impregnated surface gnate, cover with a layer of glass fiber mat; c) immediate impregnation of the glass fiber layer with a resin mixture identical to that of operation a), and d) after a drying time between 5 hours and a week, the coating wise with a protective resin layer. 2. Method according to claim 1, characterized in that the curable resin is an epoxy resin. 3. The layer of glass fibers is impregnated with the same resin mixture as that used for operation 1 above. Naturally, this mixture must be freshly prepared. About 1400 grams of the mixture per square meter is applied by brush or roller. ** ATTENTION ** end of the CLMS field may contain start of DESC **. 3. Method according to claim 1, characterized in that the curable resin is an unsaturated polyester resin and the hardener is a peroxide compound. 4. Method according to claim 3, characterized in that the two-component resin mixture contains, as an additional component, an accelerating siccative. 5. Method according to one of claims 1 to 4, characterized in that the protective resin is an isophthalic resin flexibilized internally, to which is added a hardener. 6. Method according to claim 5, characterized in that the protective resin contains, as an additional component, an accelerating siccative. The surfaces of buildings made of stone, masonry and concrete, which are exposed to the free atmosphere are subject to corrosion, which, after a more or less long period of time, damages the surface and can be followed by total destruction of the building. It is above all the pollution caused by industry, automobile exhaust gases and heaters that are responsible for the presence in the atmosphere of acidic substances such as sulfur dioxide or nitric oxides. These substances, which corrode surfaces, are especially harmful in the presence of water, that is to say in the form of rain, snow or acid fog. Other damage, especially on road constructions, is caused by the products used for thawing, such as common salt or calcium chloride. As the concentration of pollutants has increased significantly in recent years, damage to buildings has become a problem of primary importance. A particularly feared problem is the destruction of reinforced concrete. Under the influence of corrosive substances, the iron incorporated in the concrete begins to rust. The formation of rust is accompanied by swelling which forces the concrete and causes the formation of cracks. These slots facilitate access to the glowing fittings. The consequence is a chain reaction, which in a short time can lead to total destruction. Countermeasures which aim to prevent or mitigate these effects are known. On the one hand, attempts have been made to impregnate the surfaces with hydrophobic substances such as, for example, silicones. Such protection is only temporary and difficult to monitor. Other measures include painting, for example with products based on chlorinated rubber. The durability of these layers of paint is also limited and requires regular renewal. Especially if surfaces are subject to abrasion, like those of road constructions, protection with layers of paint poses problems. The object of the present invention is a method for protecting the surfaces of buildings made of stone, masonry and concrete, which, in comparison with known methods, has much safer and lasting effects. The protective layers according to the invention are absolute waterproof and have a high degree of resistance against attack than chemical and mechanical abrasion. Since they can equal be applied to wood, it has the advantage of being able to protect continuously manage masonry or concrete surfaces, which include take wooden elements. The method according to the invention consists in a treatment of the surface by a series of four successive operations including impregnating the surfaces to be protected with a mixture of resin two components comprising a hardenable resin and a harden followed immediately or after a drying time of the impregnated surface, of a covering with a layer of fibers of glass mat, then an immediate impregnation of the layer of glass fibers by a mixture of resin identical to that of the pre first operation and finally, after a drying time between 5 hours and a week, coating with a layer of professional resin cover, which may also consist of a hardenable resin two components, specially adapted to the requirements of such a layer, that is to say with a high degree of chemical resistance and mé canic. As suitable two-component curable resins for the first and third operation, for example, epoxy resins or, preferably, unsaturated polyester resins. As hardeners for the latter, gold peroxides are used ganiques such as for example ketone peroxides. By adding additionally accelerators such as siccatives based on cobalt, you can vary the pot life and the speed of hardening. The viscosity of the resin must agree with the mode of application: room temperature, good penetration into the pores of the support and complete impregnation of the glass fibers must be insured. In the first operation, we apply between 400 and 600 grams of resin for a square meter of surface. The amount necessary is determined by the character of the surface, its roughness and its porosity. The amount of accelerators used is determined by the pot life appropriate for the kind of work in question and also by room temperature. Glass fibers are usually used in the form of a mat woven or, preferably, nonwoven. Depending on the desired thickness, which can vary between 400 and 1200 grams per square meter, we apply one or more layers. The amount of resin for the third operation varies according to the thickness of the fiber layer. In any case, complete impregnation and covering of glass fibers must be insured. As protective layers (operation 4), use is preferably made of two-component resins which are internally flexible, such as, for example, phthalic acid resins or isophthalic containing styrene. Example A concrete surface comprising 5 square meters is well cleaned and dried and then, according to the invention, subjected to the following treatment: 1. Apply the mixture of 1000 g of POLYLITE 8526 "polyester resin 20 g MEKP 502 HARDENER) 2 g C3 ACCELERATOR The pot life of this mixture is limited to approximately 10 minutes; it is therefore necessary to terminate the application in this space of time. 2. A layer of glass fiber in non-woven mats with a thickness of 600 grams per square meter is laid on the surface. The layer is applied immediately after the impregnation of the support or a few hours later.