WO2004033568A1

WO2004033568A1 - Antimicrobial coatings and method for production thereof

Info

Publication number: WO2004033568A1
Application number: PCT/EP2003/008341
Authority: WO
Inventors: Detlef THÖLMANN; Peter Ottersbach
Original assignee: Creavis Gesellschaft Für Technologie Und Innovation Mbh
Priority date: 2002-09-13
Filing date: 2003-07-29
Publication date: 2004-04-22
Also published as: AU2003246737A1; DE10242561A1

Abstract

The invention relates to an antimicrobial coating, comprising polymers of cyclic amines of formula (I) with at least one unsaturated group which may be polymerised, where R1, R2 = substituted or unsubstituted, branched or unbranched, aliphatic hydrocarbons with 1 to 10 carbon atoms, which may be the same or different, R3 = H, substituted or unsubstituted, branched or unbranched, aliphatic hydrocarbons with 1 to 10 carbon atoms, R4 = H, CH3 and X = -O-, -CO-O- or -CO-NH-, a method for production of said antimicrobial coatings and the use thereof for the production of objects with antimicrobial properties

Description

Antimicrobial coatings and a process for their production

The invention relates to an antimicrobial coating, the antimicrobial coating comprising polymers of cyclic amines with at least one polymerizable unsaturated group, and to a process for producing these antimicrobial coatings and their use.

Colonization and spreading of bacteria on surfaces of pipelines, containers or packaging are highly undesirable. Mucus layers often form, which cause microbial populations to rise extremely, which have a lasting impact on the quality of water, beverages and food, and can even lead to product spoilage and consumer health damage.

Bacteria must be kept away from all areas of life where hygiene is important. This affects textiles for direct body contact, especially for the genital area and for nursing and elderly care. In addition, bacteria must be kept away from furniture and device surfaces in care stations, in particular in the area of intensive care and toddler care, in hospitals, in particular in rooms for medical interventions and in isolation stations for critical infection cases and in toilets.

Devices, surfaces of furniture and textiles against bacteria are currently being treated, if necessary, or as a precaution with chemicals or their solutions as well as mixtures that act as a disinfectant, more or less broadly and massively antimicrobially. Such chemical agents have a non-specific effect, are often themselves toxic or irritating or form degradation products which are harmful to health. Often, intolerances also appear in people who are appropriately sensitized.

A further procedure against surface bacterial spreading is the incorporation of antimicrobial substances in a matrix.

In addition, the prevention of algae growth on surfaces is an increasingly important challenge, since many exterior surfaces of buildings are now equipped with plastic cladding that is particularly easy to handle. Next to the Undesired visual impression can also be reduced under certain circumstances, the function of appropriate components. In this context, consider algae growth of photovoltaic functional areas.

Another form of microbial contamination, for which there is still no technically satisfactory solution, is the infestation of surfaces with fungi. For example, The infestation of joints and walls in damp rooms with Aspergillus niger, in addition to the impaired visual appearance, is also a serious health-related aspect, since many people are allergic to the substances released by the fungi, which can lead to serious chronic respiratory diseases.

In the field of seafaring, fouling the ship's hulls is an economically relevant influencing factor, since the increased flow resistance of the ships associated with the vegetation means a significant increase in fuel consumption. To date, such problems have generally been countered by incorporating toxic heavy metals or other low molecular weight biocides in antifouling coatings in order to alleviate the problems described. For this purpose, the harmful side effects of such coatings are accepted, but this is becoming increasingly problematic given the increased ecological sensitivity of society.

One possible solution is to use polymer biocides. For example, EP 0 290 676 describes the use of various polyacrylates and polymethacrylates as a matrix for the immobilization of bactericidal quaternary ammonium compounds.

US 3,592,805 discloses the preparation of systemic fungicides, wherein perhalogenated acetone derivatives with methacrylate esters, e.g. tert-Butylaminoethyl methacrylate, are implemented.

No. 4,515,910 describes the use of polymers of hydrogen fluoride salts of aminomethacrylates in dental medicine. The hydrogen fluoride bound in the polymers slowly emerges from the polymer matrix and is said to have effects against caries. From another technical area, for example, US Pat. No. 4,532,269 discloses a terpolymer of butyl methacrylate, tributyltin methacrylate and tert-butylaminoethyl methacrylate. This copolymer is used as an antimicrobial marine paint, whereby the hydrophilic tert-butylaminoethyl methacrylate requires the slow erosion of the polymer and thus releases the highly toxic tributyltin methacrylate as an antimicrobial agent.

In these applications, the copolymer produced with aminomethacrylates is only a matrix or carrier substance for added microbicidal active substances which can diffuse or migrate from the carrier substance. Polymers of this type lose their effect more or less quickly when the necessary "minimum inhibitory concentration" (MIC) is no longer achieved. The copolymer itself shows no or only a slight inhibitory effect.

A number of patents, e.g. EP 0 862 858 and EP 0 862 859 describe the production and use of novel antimicrobial polymers. The European

Patent EP 0 862 858 describes copolymers of tert-butylaminoethyl methacrylate and a methacrylic acid ester with a secondary amine function, which are inherently microbicidal

Possess properties. These are characterized by the fact that the effect is not on the

Release of low molecular weight biocides by diffusion, migration or hydrolysis is based, but that the polymer works in itself. The effect is long-lasting and there is no danger to the environment from released ecologically problematic substances. Around

Avoid adapting the microorganisms to existing biocides or in order to

To compensate for gaps in the active ingredient of individual biocides, one is always on the lookout for further substances, especially as an alternative to conventional, low-molecular biocides.

US Pat. No. 6,200,583 describes antimicrobial additives based on the structure of 2,2,6,6-tetramethyl-4-piperidine. These low molecular weight or oligomeric, antimicrobial compounds are mixed, inter alia, in resins and in synthetic fibers in order to achieve the antimicrobial effect of these plastics. These antimicrobial additives are characterized by good weather resistance and a low degradation rate. However, since these are low molecular weight or oligomeric compounds, release of these low molecular weight biocides into the environment is also necessary here by diffusion, migration or hydrolysis.

It was therefore the object of the present invention to provide an antimicrobial coating which, on the one hand, is distinguished by its weather resistance and a low degradation rate and, on the other hand, is to be regarded as an alternative to existing polymeric biocides.

Surprisingly, it was found that antimicrobial polymers which are produced by polymerizing cyclic amines with unsaturated groups have permanent antimicrobial properties. They are characterized by the fact that there is no release of low molecular weight biocides. Furthermore, these antimicrobial coatings according to the invention, which have these antimicrobial polymers, have very good weather resistance. Although polymers with a molecular weight of 10 ³ to 10 ⁴ of 2,2,6,6-tetramethyl-4-piperidinyl (meth) acrylate and their derivatives (DE 27 48 362, JP 54 021 489, JP 07 241 463) and of 2,2,6,6-tetramethyl-4-piperidinyl vinyl ether and its derivatives (EP 0 015 237) have been known as light stabilizers for a long time, it was not recognized that polymers with a higher molecular weight of these and similar monomers for use as antimicrobial Polymers in antimicrobial coatings are essential. The solution to the problem was all the more surprising, especially since it was shown that these antimicrobial polymers in the coatings according to the invention can have light-stabilizing effects.

The invention relates to antimicrobial coatings which have polymers of cyclic amines of the formula 1 with at least one polymerizable unsaturated group,

with Ri, R ₂ = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are each the same or different, R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, _t = -H, -CH ₃ and X = -O-, -CO-O-, -CO-NH-.

The invention furthermore relates to a process for producing antimicrobial coatings, polymers being produced from monomers of the formula 1 and applied to a substrate.

This invention also relates to the use of the antimicrobial coatings according to the invention for the production of products with antimicrobial properties.

The antimicrobial coatings produced by means of the method according to the invention are distinguished in that the effect is not based on the release of low molecular weight biocides by diffusion, migration or hydrolysis, but in that the antimicrobial polymer of the antimicrobial coating according to the invention acts in itself. This means that the effect is permanent and there is no danger to the environment from released ecologically problematic substances. The antimicrobial polymers of the antimicrobial coatings according to the invention thus inherently have the microbicidal property. Furthermore, these antimicrobial coatings according to the invention have very good weather and degradation resistance, and light-stabilizing effects.

The antimicrobial coatings according to the invention are distinguished in that they have polymers of cyclic amines of the formula 1 with at least one polymerizable unsaturated group,

with R 1, R ₂ = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are each the same or different, R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, R ₄ = -H, -CH ₃ and X = -O-, -CO-O-, -CO-NH-.

The coatings according to the invention preferably have polymers of cyclic amines of the formula 2 with at least one polymerizable unsaturated group,

2 with Ri, R = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are in each case identical or different, and R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms,

however, they particularly preferably have polymers of cyclic amines of the formula 3 with at least one polymerizable unsaturated group,

with R 1, R ₂ = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are each the same or different, R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, R ₄ = -H, -CH ₃ and

Y = -O-, -NH-.

The coatings according to the invention very particularly preferably comprise polymers of cyclic amines having polymerizable unsaturated groups selected from 2,2,6,6-tetramethyl-4-piperidinyl acrylate, 2,2,6,6-tetramethyl-4-piperidinyl methacrylate, 1,2, 2,6,6-pentamethyl-4-piperidinyl acrylate, 1, 2,2,6,6-pentamethyl-4-piperidinyl methacrylate, 2,2,6,6-tetramethyl-4-piperidinyl vinyl ether or 1,2,2,6, 6-pentamethyl-4-piperidinyl vinyl ether.

Furthermore, the antimicrobial coating according to the invention can contain further additives, such as impact modifiers. Under certain circumstances, it may be advantageous for the antimicrobial coating according to the invention to have a mixture of the antimicrobial polymers from cyclic amines with polymerizable unsaturated groups.

In a particular embodiment of the antimicrobial coating according to the invention, these can have antimicrobial homopolymers of cyclic amines with polymerizable unsaturated groups, preferably these have from 10 to 100% by weight, preferably from 10 to 50% by weight, particularly preferably from 10 to 25% by weight .-% of these antimicrobial homopolymers. In a further embodiment of the antimicrobial coatings according to the invention, they can have antimicrobial copolymers of cyclic amines with polymerizable unsaturated groups, preferably they have antimicrobial copolymers of cyclic amines with polymerizable unsaturated groups and other aliphatic unsaturated monomers, such as derivatives of acrylates and methacrylates of the general formula 4 .

with R ₅ = hydrogen atom or a methyl group,

R ₆ = hydrogen atom, a metal atom or a branched or unbranched aliphatic, cycloaliphatic, heterocyclic or aromatic hydrocarbon chain with up to 20 carbon atoms or a branched or unbranched aliphatic, cycloaliphatic, heterocyclic or aromatic hydrocarbon chain with up to 20 carbon atoms through carboxyl groups, carboxylate groups, sulfonate groups , Alkylamino groups, alkoxy groups, halogens, hydroxy groups, amino groups, dialkylamino groups, phosphate groups, phosphonate groups, sulfate groups, carboxamido groups,

Sulfonamido groups, phosphonamido groups or combinations of these groups is derivatized, R ₇ = hydrogen atom or identical to R _6;

Vinyl compounds of the general formulas 5 and 6,

R _g CH - CHR _g

and / or maleic and fumaric acid derivatives of the general formula 7

R ₈ 0 ₂ C-HC = CH-C0 ₂ R ₈

with R ₈ = hydrogen atom, an aromatic radical or a methyl group or identical to R ₆ , R ₉ = hydrogen atom, a methyl group, a hydroxyl group, identical to R ₆ or an ether corresponding to the composition OR ₆ ,

on.

These further aliphatic unsaturated monomers do not necessarily have to have an additional antimicrobial effect. Aliphatic unsaturated monomers selected from acrylic or methacrylic compounds, such as e.g. Acrylic acid, tert-butyl methacrylate, methyl methacrylate, styrene or its derivatives, vinyl chloride, vinyl ether, acrylamides, acrylonitriles, olefins (such as, for example, ethylene, propylene, butylene, isobutylene), allyl compounds, vinyl ketones, vinyl acetic acid, vinyl acetate or vinyl ester, methyl methacrylate, methacrylate, butyl acrylate , Ethyl acrylate, butyl acrylate and / or tert-butyl acrylate.

These antimicrobial copolymers of the antimicrobial coating according to the invention preferably have from 1 to 49 mol%, preferably from 1 to 30 mol% and particularly preferably from 1 to 20 mol% of these further aliphatic unsaturated monomers.

The antimicrobial coating according to the invention preferably has from 5 to 100% by weight, preferably from 15 to 50% by weight and particularly preferably from 15 to 30% by weight thereof antimicrobial copolymers.

The coating thickness of the antimicrobial coatings according to the invention is preferably from 10 μm to 10 μm, preferably from 0.1 μm to 5 μm and particularly preferably from 0.1 μm to 1 μm. When coating with lacquers or polymer melts, the coating is thicker for technical reasons, preferably from 10 μm to 500 μm, preferably from 10 μm to 100 μm and particularly preferably from 20 μm to 50 μm.

The present invention also relates to a process for the production of antimicrobial coatings, polymers being produced from monomers of the formula 1, preferably of formula 2 and particularly preferably of formula 3, and applied to a substrate. Polymers of cyclic amines with polymerizable unsaturated groups selected from 2,2,6,6-tetramethyl-4-piperidinyl acrylate, 2,2,6,6-tetramethyl-4-piperidinyl methacrylate, 1, 2,2,6 are very particularly preferred , 6-pentamethyl-4-piperidinyl acrylate, 1, 2,2,6,6-pentamethyl-4-piperidinyl methacrylate, 2,2,6,6-tetramethyl-4-piperidinyl vinyl ether or 1,2,2,6,6-pentamethyl -4-piperidinyl vinyl ether, prepared and applied to a substrate.

In a preferred embodiment of the method according to the invention, the polymer is first produced and then applied to a substrate.

The polymerization of the cyclic amines with polymerizable unsaturated groups in the process according to the invention can be described in detail using a free radical initiator using a standard method, as described, for example, in “HG-Elias, Makromolekule, Vol. 1, 6th Edition, pp. 299 ff” , or anionically preferably at temperatures from -100 ° C. to -50 ° C. and preferably from -90 ° C. to -60 ° C. and particularly preferably from -80 ° C. to -70 ° C. If the reaction is carried out appropriately, the polymerization can be carried out of the process according to the invention also take place by means of a “living” anionic polymerization, as described in “S. Creutz, P. Teyssie and R. Jeröme; Living Anionic Homo- and Block Copolymerization of 2- (tert-butylamino) ethyl methacrylate; Journal of Polymer Science, Part A, 35 (1997) 2035-2040 ". In this way, antimicrobial polymers of very defined molecular weights can be produced. In addition to the polymerization of the cyclic amines with polymerizable unsaturated groups to give the corresponding antimicrobial homopolymers, cyclic amines with polymerizable unsaturated groups with other aliphatic unsaturated monomers, such as, for example, derivatives of acrylates and methacrylates of the general formula 4, vinyl compounds of the general formulas 5 and 6 and / or Maleic and fumaric acid derivatives of the general formula 7 are copolymerized. The proportion of these further aliphatic unsaturated monomers is preferably from 1 to 49 mol%, preferably from 1 to 30 mol% and particularly preferably from 1 to 20 mol%, based on the total monomer content of the monomers for the copolymerization of the process according to the invention.

The antimicrobial polymers produced in the process according to the invention preferably have a molecular weight of 5,000 to 5,000,000 g / mol, preferably 10,000 to 5,000,000 g / mol and particularly preferably 30,000 to 5,000,000 g / mol.

In a subsequent process step of the process according to the invention, these polymers can preferably be applied as a dispersion or solution to the substrate to be coated. In addition to the antimicrobial polymers, this dispersion or solution can contain further non-antimicrobial polymers. The dispersion preferably has from 1 to 60% by weight and particularly preferably from 10 to 50% by weight of the antimicrobial polymer. Almost all substances known as dispersants, such as e.g. Triton X can be used. The solution preferably has from 0.1% by weight to 50% by weight and particularly preferably from 0.1 to 10% by weight of antimicrobial polymer. Alcohols, ketones, aldehydes, acetates or ethers can preferably be used as solvents. These solutions or dispersions of the antimicrobial polymers can preferably be applied to the substrate to be coated by dipping, spraying or painting.

The antimicrobial polymers are preferably applied to the substrate in the form of a coating formulation.

The solvent or dispersing agent can advantageously be removed by evaporation or volatilization, the evaporation or volatilization by use elevated temperatures or can be accelerated by using negative pressure or vacuum.

The curing or crosslinking of the coating according to the invention can be initiated thermally or by means of UV radiation.

The application of the polymers to a substrate can be in the form of a polymer blend or in the form of a polymer melt, which may also include other polymers selected from polyurethanes, polyamides, polyesters and ethers, polyether block amides, polystyrene, polyvinyl chloride, polycarbonates, polyorganosiloxanes, polyolefins, polysulfones, Polyisoprene, polychloroprene, polytetrafluoroethylene (PTFE), polymethacrylates, polyacrylates, can be done by coextrusion, dipping, spraying or painting. In the case of a polymer blend, this polymer melt preferably has from 0.2 to 70% by weight, preferably from 0.5 to 50% by weight, particularly preferably from 1.0 to 30% by weight, of an antimicrobial polymer composed of cyclic amines with polymerizable unsaturated groups.

All polymeric plastics, such as e.g. Polyurethanes, polyamides, polyesters and ethers, polyether block amides, polystyrene, polyvinyl chloride, polycarbonates, polyorganosiloxanes, polyolefins, polysulfones, polyisoprene, polychloroprene, polytetrafluoroethylene (PTFE), corresponding copolymers and blends, and natural and synthetic rubbers, with or without radiation-sensitive groups, can be used. The method according to the invention can also be applied to surfaces of lacquered or otherwise plastic, metal, glass or wooden bodies.

In a further embodiment of the process according to the invention, the antimicrobial polymers from cyclic amines in dissolved or dispersed form are also used for the antimicrobial impregnation of porous materials. A possible method is described in German patent application DE 10 122 149.

In a preferred embodiment of the process according to the invention, the monomers are polymerized on a substrate.

In a further preferred embodiment of the process according to the invention, the cyclic amines with polymerizable unsaturated groups, particularly preferably with one or more further aliphatic unsaturated monomers, graft-polymerized on a substrate.

The surfaces of the substrates are preferably activated by a number of methods before the graft polymerization. Advantageously, they are freed of oils, fats or other contaminants beforehand in a known manner by means of a solvent.

The substrate can be activated in the process according to the invention by UV radiation with and without additional photosensitizer, plasma treatment, corona treatment, flame treatment, ozonization, electrical discharge or γ-radiation.

The activation of the substrate from standard polymers can be done by UV radiation. A suitable radiation source can e.g. B be a UV excimer device HERAEUS Noblelight, Hanau, Germany. However, mercury vapor lamps can also be used for substrate activation, provided that they emit considerable amounts of radiation in the areas mentioned. The exposure time is preferably from 0.1 seconds to 20 minutes, preferably from 1 second to 10 minutes. The activation of the substrate from standard polymers with UV radiation can also be carried out with an additional photosensitizer. For this purpose, the photosensitizer, e.g. Benzophenone, applied to the substrate surface and irradiated. This can also be done with a mercury vapor lamp with exposure times preferably from 0.1 seconds to 20 minutes, preferably from 1 second to 10 minutes.

According to the invention, the activation can also be achieved by a high-frequency or microwave plasma (Hexagon, Technics Plasma, 85551 Kirchheim, Germany) in air, nitrogen or argon atmosphere. The exposure times are preferably from 30 seconds to 30 minutes, preferably from 2 to 10 minutes. The energy input in laboratory devices is preferably from 100 to 500 W, preferably from 200 to 300 W.

Corona devices (e.g. from SOFTAL, Hamburg, Germany) can also be used for activation. In this case, the exposure times are preferably from 1 to 10 minutes, preferably from 1 to 60 seconds. Activation by electron or γ-rays (eg from a cobalt 60 source) and ozonization can allow short exposure times, which are preferably from 0.1 to 60 seconds.

Flaming surfaces can also activate them. Suitable devices, in particular those with a flame barrier front, can be built in a simple manner or can be obtained, for example, from ARCOTEC, 71297 Mönsheim, Germany. They can be operated with hydrocarbons or hydrogen as fuel gas. In any case, harmful overheating of the substrate should be avoided, which can easily be achieved by intimate contact with a cooled metal surface on the substrate surface facing away from the flame side. The activation by flame treatment can accordingly be restricted to relatively thin, flat substrates. The exposure times are preferably from 0.1 seconds to 1 minute, preferably from 0.5 to 2 seconds, all of which are non-luminous flames and the distances from the substrate surfaces to the outer flame front are preferably from 0.2 to 5 cm, preferably from 0.5 to 2 cm can.

The substrate surfaces activated in this way can be coated with the unsaturated monomers, if appropriate in solution, by known methods, such as dipping, spraying or brushing. Water and water-ethanol mixtures have proven to be preferred as solvents, but other solvents can also be used, provided that they have sufficient solvent power for the monomers and wet the substrate surfaces well. Solutions with monomer contents of preferably from 1 to 10% by weight, preferably at about 5% by weight, have proven themselves in practice and can in general in one pass coherent coatings covering the substrate surface with layer thicknesses which can be more than 0.1 μm , result.

The graft polymerization of the monomers applied to the activated surfaces can expediently be effected by radiation in the short-wave segment of the visible region or in the long-wave segment of the UV region of the electromagnetic radiation. For example, the radiation from a UV excimer of the wavelengths of preferably from 250 to 500 nm, preferably from 290 to 320 nm, is particularly suitable. Mercury vapor lamps can also be suitable here, provided they emit considerable amounts of radiation in the ranges mentioned. The exposure times are preferably from 10 seconds to 30 minutes, preferably from 2 to 15 minutes.

Further objects of the present invention are the use of the antimicrobial coating according to the invention for the production of antimicrobial products and the products thus produced as such. Such products are preferably based on polyamides, polyurethanes, polyether block amides, polyester amides or imides, PVC, polyolefins, silicones, polysiloxanes, polymethacrylate or polyterephthalates, which have a coating according to the invention.

Antimicrobial products of this type are, for example, and in particular machine parts for food processing, components of air conditioning systems, roofing, bathroom and toilet articles, kitchen articles, components of sanitary facilities, components of animal cages and dwellings, toys, components in water systems, food packaging, operating elements (touch panel ) of devices and contact lenses.

The present invention also relates to the use of the coatings according to the invention or of the antimicrobial coatings produced by the process according to the invention for the production of hygiene articles or medical articles. The above statements about preferred materials apply accordingly. Such hygiene products can for example be toothbrushes, toilet seats, combs and packaging materials. Other items that may be come into contact with many people, such as telephone receivers, handrails of stairs, door and window handles as well as holding belts and handles in public transport. Medical technology articles are e.g. B. catheters, tubes, cover sheets or surgical cutlery.

The coatings according to the invention or the antimicrobial coatings produced according to the method according to the invention can be used wherever bacteria-free, ie microbicidal surfaces or surfaces with non-stick properties are important. Examples of uses for the antimicrobial coatings according to the invention are in particular paints or protective coatings in the following areas:

• Marine: hulls, port facilities, buoys, drilling platforms, ballast water tanks

• House: roofs, cellars, walls, facades, greenhouses, sun protection, garden fences, wood protection • Sanitary: Public toilets, bathrooms, shower curtains, toiletries, swimming pool, sauna, joints, sealing compounds

• Food: machines, kitchen, kitchen items, sponges, toys, food packaging, milk processing, drinking water systems, cosmetics

• Machine parts: air conditioners, ion exchangers, process water, solar systems, heat exchangers, bioreactors, membranes

• Medical technology: contact lenses, diapers, membranes, implants

• Articles of daily use: car seats, clothing (stockings, sportswear), hospital facilities, door handles, telephone receivers, public transport, animal cages, cash registers, carpeting, wallpaper.

Furthermore, the coatings according to the invention can be used as a biofouling inhibitor, in particular in cooling circuits. To avoid damage to cooling circuits caused by algae or bacteria, they should be cleaned frequently or built accordingly oversized. The addition of microbicidal substances, such as Formalm, is often not possible with open cooling systems, as are common in power plants or chemical plants. Other microbicidal substances are often highly corrosive or foam-forming, which prevents use in such systems. In contrast, it is possible to use the coatings according to the invention in plant components in the process water sector. The bacteria are killed on the antimicrobial polymers. A deposit of bacteria or algae on plant parts can be effectively prevented.

To further describe the present invention, the following examples are given, which further illustrate the invention but are not intended to limit the scope thereof, as set out in the patent claims.

Example 1 15.0 g of 2,2,6,6-tetramethyl-4-piperidinyl methacrylate and 120 ml of cyclohexane were added Shielding gas heated to 65 ° C. After the temperature had been reached, 0.15 g of azobisisobutyronitrile dissolved in 4 ml of 2-butanone were added over the course of 10 minutes. The mixture was heated to 70 ° C and after 48 hours the reaction was stopped by stirring the mixture in 400 mL water. The reaction product was filtered off and dried in vacuo at 50 ° C. for 48 hours.

Example la:

0.5 g of the product from Example 1 was placed in 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 15 minutes, 1 ml of the test microbial suspension was removed, and the number of microbes in the test mixture was determined. After this time, no Staphylococcus aureus germs were detectable.

Example lb:

0.5 g of the product from Example 1 was placed in 20 ml of a test microbial suspension of Pseudomonas aeruginosa and shaken. After a contact time of 60 minutes, 1 ml of the test microbial suspension was removed and the number of microbes in the test mixture was determined. After this time, the number of bacteria had dropped from 10 ⁷ to 10 ² .

Example 2 14.0 g of 2,2,6,6-tetramethyl-4-piperidinyl acrylate and 120 ml of cyclohexane were heated to 65 ° C. under a protective gas. After the temperature had been reached, 0.15 g of azobisisobutyronitrile dissolved in 4 ml of 2-butanone were added over the course of 10 minutes. The mixture was heated to 70 ° C and after 48 hours the reaction was stopped by stirring the mixture in 400 mL water. The reaction product was filtered off and dried in vacuo at 50 ° C. for 48 hours.

Example 2a:

0.5 g of the product from Example 2 was placed in 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 15 minutes, 1 ml of the test microbial suspension was removed, and the number of microbes in the test mixture was determined. After this time, no Staphylococcus aureus germs were detectable.

Example 2b 0.5 g of the product from Example 2 was placed in 20 ml of a test microbial suspension of Pseudomonas aeruginosa and shaken. After a contact time of 60 minutes, 1 ml of the test microbial suspension was removed and the number of microbes in the test mixture was determined. After this time, the number of bacteria had dropped from 10 ⁷ to 10 ² .

Example 3 16.0 g of l, 2,2,6,6-pentamethyl-4-piperidinyl methacrylate and 120 ml of cyclohexane were heated to 65 ° C. under protective gas. After the temperature had been reached, 0.15 g of azobisisobutyronitrile dissolved in 4 ml of 2-butanone were added over the course of 10 minutes. The mixture was heated to 70 ° C and after 48 hours the reaction was stopped by stirring the mixture in 400 mL water. The reaction product was filtered off and dried in vacuo at 50 ° C. for 48 hours.

Example 3 a: 0.5 g of the product from Example 3 was placed in 20 ml of a test germ suspension of Staphylococcus aureus and shaken. After a contact time of 15 minutes, 1 ml of the test microbial suspension was removed and the number of microbes in the test mixture was determined. After this time, no Staphylococcus aureus germs were detectable.

Example 3b

0.5 g of the product from Example 3 was placed in 20 ml of a test microbial suspension of Pseudomonas aeruginosa and shaken. After a contact time of 60 minutes, 1 ml of the test microbial suspension was removed and the number of microbes in the test mixture was determined. After this time, the number of bacteria had dropped from 10 ⁷ to 10 ² .

Example 4 100 mg of the product from Example 1 were dissolved in one liter of cyclohexane. 5 mL of this solution were placed in the interior of a 50 mL chemical glass bottle. This was sealed and placed on a roller mixer for 1 minute, which ensured homogeneous contact between the inside of the bottle and the solution. The bottle was then opened, the solution was removed and the opened bottle was rotated under a hood for 6 hours on a roller mixer so that a uniform evaporation of solvent residues could take place. Subsequently, the pre-dried coating was then dried for a further 24 hours at 35 ° C. in a vacuum drying cabinet at approx. 1 mbar.

The bottle was leached with 45 mL of 37 ° C water for 24 hours. The coating was still transparent afterwards. The water was removed and 2 ml of it were placed in a beaker, which was then mixed with 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 was removed and the number of microbes in the test mixture was determined. After this time, the bacterial count of 10 ⁷ germs per mL had remained constant, taking into account the increased liquid volume.

Then 20 mL of a test germ suspension of Staphylococcus aureus were added to the originally coated bottle, which was then shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension was removed and the number of microbes in the test mixture was determined. After this time, no Staphylococcus aureus germs were detectable.

Example 5

100 mg of the product from Example 2 were dissolved in one liter of cyclohexane. 5 mL of this solution were placed in the interior of a 50 mL chemical glass bottle. This was sealed and placed on a roller mixer for 1 minute, which ensured homogeneous contact between the inside of the bottle and the solution. The bottle was then opened, the solution was removed and the opened bottle was rotated under a hood on a roller mixer for 6 hours, so that uniform evaporation of solvent residues could take place. Subsequently, the pre-dried coating was then dried for a further 24 hours at 35 ° C. in a vacuum drying cabinet at approx. 1 mbar.

The bottle was leached with 45 mL of 37 ° C water for 24 hours. The coating was still transparent afterwards. The water was removed and 2 ml of it were placed in a beaker, which was then washed with 20 ml of a Test germ suspension of Staphylococcus aureus was added and shaken. After a contact time of 4 hours, 1 ml of the test microbial suspension was removed and the number of microbes in the test mixture was determined. After this time, the bacterial count of 10 ⁷ germs per mL had remained constant, taking into account the increased liquid volume.

Claims

claims:

1. antimicrobial coating, characterized in that the antimicrobial coating comprises polymers of cyclic amines of the formula 1 with at least one polymerizable unsaturated group,

with Ri, R = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are each the same or different, R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms,

R ₄ = -H, -CH ₃ and X = -O-, -CO-O-, -CO-NH-.

2. Antimicrobial coating according to claim 1, characterized in that the antimicrobial coating comprises polymers of cyclic amines of the formula 2 with at least one polymerizable unsaturated group.

2 with Ri, R ₂ = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon having 1 to 10 carbon atoms, which are in each case the same or different and R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms.

3. Antimicrobial coating according to claim 1, characterized in that the antimicrobial coating comprises polymers of cyclic amines of the formula 3 with at least one polymerizable unsaturated group.

with R 1, R ₂ = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are each the same or different, R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, R ₄ = -H, -CH ₃ and Y = -O-, -NH-.

4. Antimicrobial coating according to claim 1, characterized in that the antimicrobial coating polymers of cyclic amines with at least one polymerizable unsaturated group selected from 2,2,6,6-tetramethyl-4-piperidinylacrylate, 2,2,6,6- Tetramethyl-4-piperidinyl methacrylate, 1, 2,2,6,6-pentamethyl-4-piperidinyl acrylate, l, 2,2,6,6-pentamethyl-4-piperidinyl methacrylate, 2,2,6,6-

Tetramethyl-4-piperidinyl vinyl ether or 1, 2,2,6,6-pentamethyl-4-piperidinyl vinyl ether.

5. antimicrobial coating according to at least one of claims 1 to 4, characterized in that the polymer is a copolymer.

6. Antimicrobial coating according to claim 5, characterized in that the copolymer has further aliphatic unsaturated monomers.

7. Antimicrobial coating according to claim 6, characterized in that the copolymer has from 1 to 49 mol% of further aliphatic unsaturated monomers.

8. Antimicrobial coating according to at least one of claims 5 to 7, characterized in that the antimicrobial coating comprises from 5 to 100% by weight of the copolymer.

9. Antimicrobial coating according to at least one of claims 1 to 4, characterized in that the polymer is a homopolymer.

10. Antimicrobial coating according to claim 9, characterized in that the antimicrobial coating comprises from 10 to 100% by weight of the homopolymer.

11. A process for the preparation of antimicrobial coatings, characterized in that polymers of monomers of the formula 1

1 with Ri, R ₂ = substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, which are in each case the same or different,

R ₃ = -H, substituted or unsubstituted, branched or unbranched aliphatic hydrocarbon with 1 to 10 carbon atoms, * = -H, -CH ₃ and

X = -O-, -CO-O-, -CO-NH-

manufactured and applied to a substrate.

12. The method according to claim 11, characterized in that the polymerization of the monomers takes place on a substrate.

13. The method according to claim 12, characterized in that the monomers are graft-polymerized on a substrate.

14. The method according to claim 13, characterized in that the substrate is activated before the graft polymerization.

15. The method according to claim 14, characterized in that the activation of the substrate by UV radiation with and without additional

Photosensitizer, plasma treatment, corona treatment, flame treatment, ozonization, electrical discharge or γ-radiation takes place.

16. The method according to claim 11, characterized in that the polymers are first produced and then applied to a substrate.

17. The method according to claim 16, characterized in that the polymers are applied in the form of a coating formulation to the substrate.

18. The method according to claim 16, characterized in that the polymers are applied in the form of a polymer blend on the substrate.

19. The method according to claim 16, characterized in that the polymers are applied as a solution to the substrate.

20. The method according to claim 16, characterized in that the polymers are applied as a dispersion to the substrate.

21. Use of the antimicrobial coating according to at least one of claims 1 to 10 for the production of products with antimicrobial properties.

22. Use according to claim 21 for the production of medical articles and hygiene articles.