EP1341740A1

EP1341740A1 - Method for using antimicrobial polymers for the protection of buildings and monuments

Info

Publication number: EP1341740A1
Application number: EP01270508A
Authority: EP
Inventors: Peter Ottersbach; Beate Kossmann
Original assignee: Creavis Gesellschaft fuer Technologie und Innovation mbH
Current assignee: Creavis Gesellschaft fuer Technologie und Innovation mbH
Priority date: 2000-12-13
Filing date: 2001-11-13
Publication date: 2003-09-10
Also published as: DE10062201A1; WO2002048070A1; AU2002217023A1; US20040024082A1

Abstract

The invention relates to a method for using antimicrobial polymers for the protection of buildings and monuments by impregnating the surfaces with an antimicrobial polymer.

Description

Process for the use of antimicrobial polymers in building and monument protection

The invention relates to a method for using antimicrobial polymers in building and monument protection.

As a result of the development of civilization, cultural monuments that are worth preserving have been being built successively for thousands of years, and more recently industrial monuments. The problem of preserving these monuments before decay is becoming increasingly problematic, especially in the face of increased air pollution. As a result, the surfaces of the monuments are chemically attacked, which facilitates a milσobial decomposition process of these surfaces. This form of decomposition is also called biocorrosion. In particular, molds, e.g. Aspergilus niger, a prominent role. They penetrate the pores of the materials, be it e.g. Concrete, sandstone, wood or even glasses, and cause a gradual decay of the affected surfaces through their metabolism. In Germany alone, around 30 billion euros have to be spent on preserving monuments each year.

In addition, there is naturally also the desire for prophylactic protection for new buildings in order to completely avoid the problems described.

So far, there have been two possible solutions to this problem. On the one hand, a protective layer of hydrophobic coatings is applied to the restored surfaces to keep water and microbes from the surface. However, this approach only works for a short time because the microbes find ways to attach themselves to hydrophobic surfaces. As a result, the coatings are damaged so that a microbial attack can occur through the protective layer, ultimately resulting in a partial detachment of the affected areas.

The second approach consists in the massive use of low molecular weight biocides, which are usually applied as an additive in paints to the surfaces to be protected. Since a single downpour often flushes out more than half of the active substances, this type of surface protection is generally only used for interior surfaces, such as those found on frescos, sculptures and paintings. Another serious disadvantage of this method is the toxicity of the biocidal substances, which results in the restorers being able to apply these biocidal systems only briefly and using respiratory and skin protection.

From European patent applications 0 862 858 it is known that copolymers of tert-butylaminoethyl methacrylate, a methacrylic acid ester with a secondary amino function, have inherent microbicidal properties. The antimicrobial effectiveness of these polymeric systems is closely related to their three-dimensional structure, conformation and available surface. They are particularly suitable in areas of application where long-lasting, surface-active protection against microbial attack is important.

The weather and light stability of these antimicrobial systems in long-term use is still problematic.

The present invention is therefore based on the object of providing a method for protecting buildings, monuments and cultural assets made of stones, minerals, concrete, wood, glasses, clays or ceramics against bio-corrosion.

It has now surprisingly been found that this task can be solved in an ecologically and ecologically ideal manner by using antimcrobial polymers.

The present invention therefore relates to a process for the surface impregnation of building materials against microbial attack, a solution of an antimicrobial polymer being applied to the surfaces.

As building materials are understood all materials commonly used in house construction, such as. B. natural or artificial stone, minerals, concrete, wood plaster, glass, clay, cement, mortar or ceramic.

The method according to the invention is used in particular in the case of old or strong environmental influences exposed buildings for their preservation, such as bridges, dams, bank fortifications, quay facilities, halls, castles, palaces, churches, power plant chimneys, etc.

In the process according to the invention, the antimicrobial polymer can be dissolved in an organic solvent or dispersed in an aqueous solvent and introduced into an optionally porous surface of the material to be treated. This can e.g. by brushing, spraying or inserting, d. H. Soak the substrate in an appropriate solution, if necessary also under increased pressure, so that the result is a surface impregnated with an antimicrobial polymer. The antimicrobial polymer is located in the pores of the substrate, so that a potential microbial attack can be prevented not only spatially, but also chemically and efficiently. Since the antimicrobial property is inherent in the polymer itself, washing out of the active species is excluded on principle. In addition, antimicrobial polymers generally carry hydrophilic groups, which lead to swelling of the polymer in contact with water, so that when moisture is required for microbial attacks, the polymer swells in the pores of the substrate, which ultimately results in a complete sealing of these pores leads. Since the antimicrobial polymers are significantly less toxic than low-molecular biocides due to their polymer structure, ecologically and toxicologically safe processing of these substances to impregnate the material is also possible.

In order to prevent the inherent disadvantages of the antimilαObial polymers, such as, for example, insufficient light or weather stability, the process can be combined with the use of an additional protective coating, which itself has only the task of providing the stabilities described and, if appropriate, other optically or mechanically desired properties contribute. In this embodiment of the invention, a further surface treatment for sealing is carried out after the surface impregnation. With this type of two-layer protection, a high degree of material protection can be assumed, since even if the first protective layer is damaged, a microbial attack on the substrate is effectively prevented by the antimicrobial polymer present in the pores. The additional protective layer applied by the seal preferably contains no monomers, but z. B. polymethyl methacrylate as UV protection.

The surfaces treated in this way show an antimicrobial effectiveness that is permanent and resistant to environmental influences and physical stress. These coatings do not contain any low-molecular ¹ biocides, which effectively rules out the migration of ecologically problematic substances over the entire period of use.

Nitrogen and phosphorus functionalized monomers are preferably used to prepare the microbial polymers.

Particularly preferred monomers are methacrylic acid 2-tert-butylaminoethyl ester, methacrylic acid 2-diethylaminoethyl ester, methacrylic acid 2-diethylaminomethyl ester, acrylic acid 2-tert-butylaminoethyl ester, acrylic acid 3-dimethylaminopropyl ester, acrylic acid 2-diethylaminoethyl ester, acrylic acid 2-dimethylaminoethyl ester, dimethylaminopropyl methacrylamide, diethylaminopropyl methacrylamide, acrylic acid 3-dimethylaminopropylamide, 2-methacryloyloxyethyltrimethylammonium methosulfate, methacrylic acid 2-diethylaminoethyl ester, 2-methacryloyloxyethyltrimethylammonium chloride, 3-methacryloylmethylmethylammonylammonium aminomethylammonylmethylammonylmethylamethylammonylimethylammoniumimethylammoniumimethylammoniumimethylammonylmethylammonylmethylammonylmethylammonylmethylammonylmethylammonylmethylammonylmethylammonylmethylamethylamethylmethylmethylamethylmethylamethylamethylamethylamethylamethylamethylamethylmethylmethylamethylammonylmethylmethylamethylammonium Methacryloyloxyethyl-4-benzoyldimethylammonium bromide, allyltriphenylphosphonium bromide, allyltriphenylphosphonium chloride, 2-acrylamido-2-methyl-1-propane sulfonic acid, 2-diethylaminoethyl vinyl ether, 3 - aminopropyl vinyl ether.

Use of the modified polymer substrates

Further objects of the present invention are the use of the antimicrobial surfaces according to the invention in the protection of buildings and monuments. Such surfaces are preferably based on building materials, such as concrete, cement, mortar, natural and artificial stones, minerals, clays, woods, glasses and ceramics, which have surfaces impregnated with polymers according to the invention. To further describe the present invention, the following examples are given, which further illustrate the invention but are not intended to limit its scope as set out in the claims.

Example 1:

50 ml of dimethylaminopropyl methacrylamide (Aldrich) and 250 ml of ethanol are placed in a three-necked flask and heated to 65 ° C. under a stream of argon. Then 0.6 g of azobisisobutyronitrile dissolved in 20 ml of ethyl methyl ketone are slowly added dropwise with stirring. The mixture is heated to 70 ° C. and stirred at this temperature for 72 hours. After this time, the reaction mixture is stirred into 1.5 l of deionized water, the polymeric product precipitating. After filtering off the product, the filter residue is rinsed with 100 ml of a mixture of ethanol / demineralized water in a ratio of 1: 1 in order to remove any residual monomers still present. The product is then dried in vacuo at 50 ° C for 24 hours. 2 g of the product are dissolved in 10 g of ethanol and applied to a 0.5 cm thick and 3 by 3 cm sandstone using a 100 micron doctor blade. The stone is then dried at 50 ° C for 24 hours.

Example la: The stone from example 1 is placed with its coated side up on the bottom of a beaker containing 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension is removed, and the number of microbes in the test mixture is determined. After this time, no Staphylococcus aureus germs can be detected.

Example lb:

The stone from Example 1 is placed with its coated side up on the bottom of a beaker containing 20 ml of a test microbial suspension of Pseudomonas aeruginosa and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension is removed, and the number of microbes in the test mixture is determined. After this time the number of germs has decreased from 10 ⁷ to 10 ² germs per ml. Example lc:

Each impregnated stone from Example 1 is treated with Chlorella sp., Trentepohlia sp., Gloeocapsa sp. Calothrix sp. and Aspergilus niger. These samples are then placed in an incubator for 3 weeks. In contrast to running control samples, no growth can be detected in any of the impregnated stones.

Example 2:

50 ml of tert-butylaminoethyl methacrylate (Aldrich) and 250 ml of ethanol are placed in a three-necked flask and heated to 65 ° C. under a stream of argon. Then 0.6 g of azobisisobutyronitrile dissolved in 20 ml of ethyl methyl ketone are slowly added dropwise with stirring. The mixture is heated to 70 ° C. and stirred at this temperature for 72 hours. After this time, the reaction mixture is stirred into 1.5 l of deionized water, the polymeric product precipitating. After filtering off the product, the filter residue is rinsed with 100 ml of a mixture of ethanol / demineralized water in a ratio of 1: 1 in order to remove any residual monomers still present. The product is then dried in vacuo at 50 ° C for 24 hours. 2 g of the product are dissolved in 10 g of ethanol and applied to a 0.5 cm thick and 3 by 3 cm sandstone using a 100 micron doctor blade. The stone is then dried at 50 ° C for 24 hours.

Example 2a:

The stone from Example 2 is placed with its coated side up on the bottom of a beaker containing 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension is removed, and the number of microbes in the test mixture is determined. After this time, no Staphylococcus aureus germs can be detected.

Example 2b

The stone from Example 2 is placed with its coated side up on the bottom of a beaker containing 20 ml of a test microbial suspension of Pseudomonas aeruginosa and shaken. After a contact time of 4 hours, 1 ml of the test germ suspension removed, and the number of bacteria in the test batch determined. After this time the number of germs has decreased from 10 ⁷ to 10 ² germs per ml.

Example 2c: Each impregnated stone from Example 2 is treated with Chlorella sp., Trentepohlia sp., Gloeocapsa sp. Calothrix sp. and Aspergilus niger. These samples are then placed in an incubator for 3 weeks. In contrast to running control samples, no growth can be detected in any of the impregnated stones.

Example 3:

50 ml of tert-butylaminoethyl methacrylate (Aldrich) and 250 ml of ethanol are placed in a three-necked flask and heated to 65 ° C. under a stream of argon. Then 0.6 g of azobisisobutyronitrile dissolved in 20 ml of ethyl methyl ketone are slowly added dropwise with stirring. The mixture is heated to 70 ° C. and stirred at this temperature for 72 hours. After this time, the reaction mixture is stirred into 1.5 l of demineralized water, the polymeric product precipitating. After filtering off the product, the filter residue is rinsed with 100 ml of a mixture of ethanol / demineralized water in a ratio of 1: 1 in order to remove any residual monomers still present. The product is then dried in vacuo at 50 ° C for 24 hours. 0.5 g of the product is dissolved in 10 g of ethanol. A 1 cm thick and 2 x 3 cm large beechwood plate is placed in this solution for 30 minutes. The wood is then dried at 50 ° C for 24 hours.

Example 3a: The piece of wood from Example 3 is locked on the bottom of a beaker containing 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension is removed, and the number of microbes in the test mixture is determined. After this time, no Staphylococcus aureus germs can be detected.

Example 3b The piece of wood from Example 3 is locked on the bottom of a beaker containing 20 ml of a test germ suspension of Pseudomonas aeruginosa and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension is removed, and the number of microbes in the test mixture is determined. After this time, no Staphylococcus aureus germs can be detected.

Example 3 c:

Each impregnated piece of wood from Example 3 is chlorella sp., Trentepohlia sp., Gloeocapsa sp. Calothrix sp. and Aspergilus niger. These samples are then placed in an incubator for 3 weeks. In contrast to accompanying control samples, no growth can be detected in any of the impregnated pieces of wood.

Example 4: 50 ml of tert-butylaminoethyl methacrylate (Aldrich) and 250 ml of ethanol are placed in a three-necked flask and heated to 65 ° C. under a stream of argon. Then 0.6 g of azobisisobutyronitrile dissolved in 20 ml of ethyl methyl ketone are slowly added dropwise with stirring. The mixture is heated to 70 ° C. and stirred at this temperature for 72 hours. After this time, the reaction mixture is stirred into 1.5 l of demineralized water, the polymeric product precipitating. After filtering off the product, the filter residue is rinsed with 100 ml of a mixture of ethanol / demineralized water in a ratio of 1: 1 in order to remove any residual monomers still present. The product is then dried in vacuo at 50 ° C for 24 hours. 2 g of the product are dissolved in 10 g of ethanol and applied to a 1 cm thick and 2 by 3 cm large piece of concrete with a 100 micrometer doctor blade. The concrete piece is then dried at 50 ° C for 24 hours.

Example 4a

The concrete piece from Example 4 is placed with its coated side up on the bottom of a beaker containing 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 4 hours, 1 ml of

Test microbial suspension removed, and the number of bacteria in the test batch determined. After expiration During this time, no Staphylococcus aureus germs can be detected.

Example 4b

The concrete piece from Example 4 is placed with its coated side upward on the bottom of a beaker containing 20 ml of a test microbial suspension of Pseudomonas aeruginosa and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension is removed, and the number of microbes in the test mixture is determined. After this time the number of germs has decreased from 10 ⁷ to 10 ² germs per ml.

Example 4c

Each impregnated piece of concrete from Example 4 is treated with Chlorella sp., Trentepohlia sp., Gloeocapsa sp. Calothrix sp. and Aspergilus niger. These samples are then placed in an incubator for 3 weeks. In contrast to accompanying control samples, no growth can be detected in any of the impregnated concrete pieces.

Claims

claims:

1. Process for the surface impregnation of building materials against microbial attack, characterized by the fact that a solution of an antimicrobial polymer is applied to the surfaces.

2. The method according to claim 1, characterized in that the building materials natural or artificial stone, minerals, concrete, wood, plaster, glass, clay, cement, mortar or ceramic, are each processed or unprocessed.

3. The method according to claim 1 or 2, characterized in that the building materials are coated with the solution of the microbicidal polymer, sprayed or soaked.

4. The method according to any one of claims 1 to 3, characterized in that a further surface treatment for sealing is carried out after the surface impregnation.

5. The method according to claim 4, characterized in that the sealing layer contains no antimicrobial polymers.

6. The method according to any one of claims 1 to 5, characterized in that the antimicrobial polymers are dissolved in an organic solvent or dispersed in an aqueous solvent.

7. The method according to any one of claims 1 to 6, characterized in that the microbicidal polymers from at least one nitrogen or

Phosphorus functionalized monomers are produced.

8. The method according to any one of claims 1 to 7, characterized in that the microbicidally active polymers were prepared from at least one of the following monomers: 2-tert-butylaminoethyl methacrylic acid, 2-diethylaminoethyl methacrylic acid, 2-diethylaminomethyl methacrylic acid, acrylic acid -2-tert-butylaminoethyl

3-dimethylaminopropyl acrylate, 2-diethylaminoethyl acrylate, 2-dimethylarninoethyl acrylate, dimethylaminopropyl methacrylamide,

Diethylaminopropyl methacrylamide, acrylic acid-3-dimethylaminopropylamide, 2-

Methacryloyloxyethyltrimethylammonium, methacrylic acid-2-diethylamino-ethyl ester, 2-methacryloyloxyethyltrimethylammonium chloride, 3-meth- acryloylaminopropyltrimethylammoniumchlorid, 2-methacryloyloxyethyltrimethylammonium chloride, 2-acryloyloxyethyl 4-benzoyldimethylammoniumbromid, 2-methacryloyloxyethyl 4-benzoyldimethylammoniumbromid, Allyltriphenyl- phosphonium Allyltriphenylphosphoniumchlorid, 2- Acrylamido-2-methyl-1-propanesulfonic acid, 2-diethylaminoethyl vinyl ether, 3-aminopropyl vinyl ether.

9. Use of the impregnated building materials in building or monument protection.