WO2005045144A2

WO2005045144A2 - Water-conducting body comprising a coating of a glass-like composite matrix

Info

Publication number: WO2005045144A2
Application number: PCT/EP2004/052867
Authority: WO
Inventors: Bastian Schaefer; Dietmar Lux
Original assignee: Damixa A/S
Priority date: 2003-11-06
Filing date: 2004-11-08
Publication date: 2005-05-19
Also published as: DE10351902A1; WO2005045144A3

Abstract

The invention concerns the field of water-conducting bodies, particularly of plumbing fixtures such as sanitary fixtures, kitchen fixtures, and/or bathroom fixtures. The invention additionally relates to the use of glass-like sol-gel materials for coating bodies of this type and to methods for producing such coatings. The inventive water-conducting bodies, particularly fittings, are protected against metal, particularly lead, copper and nickel from escaping into the water to be conducted.

Description

Aquatic body

The invention relates to the field of water-conducting bodies, in particular fittings such as sanitary, kitchen and / or bathroom fittings. The invention further relates to the use of glass-like sol-gel materials for coating such bodies and methods for producing such coatings.

Water-conducting bodies, for example pipes, are often produced by casting processes. A frequently used material is brass, especially in the manufacture of fittings such as sanitary and bathroom fittings. In the case of cast fittings, but also in the case of other water-conducting bodies, the problem frequently arises that undesirable components of the body or of the fitting itself can enter the piped water. The undesirable components include heavy metals such as lead, but also zinc, nickel and copper. These may only occur in very low concentrations, especially in drinking water, preferably they should not be contained in drinking water. Numerous solutions have been proposed to prevent undesired components from escaping from water-conducting bodies. A sanitary water valve is known from DE 43 13 439 A1, the outlet of which is coated on the water side with a plastic coating. However, this coating is difficult to produce.

Faucets are therefore conventionally subjected to intensive surface cleaning, in the course of which the surfaces in contact with water are cleaned of undesirable constituents and metals are washed out of the water-conducting bodies. This treatment is also complex.

The invention is therefore based on the object of specifying a water-conducting body which is to be as simple to manufacture as possible and which reduces or preferably completely prevents the entry of undesired constituents into the water to be conducted. The water-conducting body should be particularly suitable as a water-conducting agent in a fitting, in particular a sanitary, kitchen and / or bathroom fitting, and as a valve insert or element of a valve insert for such a fitting.

The object is achieved by a water-conducting body according to claim 1.

Such a body can in particular be a pipe, a sanitary device such as a shower cubicle, tile, shower tray, sink, bathtub, toilet and a fitting, in particular a bathroom and / or kitchen fitting, and / or a kitchen appliance such as a pot or a pan be, or part of such a body, for example a valve insert or an element of a valve insert of a fitting. The fitting can in particular be divided into two with separate setting means for independently setting the amount of hot and cold water that is to be dispensed from the fitting. The fitting can also be provided with an electrically, electronically or mechanically operating thermostat. A thermostatically controlled fitting allows the temperature of the water to be dispensed to be set to a preselected setpoint. The valve can be a spherical Have cartridge and / or a disk cartridge, in particular with a ceramic disk and / or ceramic seal or electromagnetically controlled valves. Preferred ceramics, which are coated with the coating according to the invention to form a water-conducting body, contain one or more aluminum oxides. Coatable surfaces of a fitting can in particular be:

Connecting pipes, in particular copper pipes and pipes with an at least partially chromium and / or nickel coated surface;

Connecting pieces, in particular those made of brass and those with an at least partially chrome and / or nickel coated surface;

Mixing bodies, in particular those made of brass and those with an at least partially chromium and / or nickel coated surface;

Valve inserts and valve bodies, in particular those made of brass and those with an at least partially chrome and / or nickel coated surface;

Regulating means, in particular as components of a valve, furthermore in particular those made of ceramic, brass, stainless steel, plastic and / or rubber;

- Aerators (spouts), especially those made of brass and those with an at least partially chrome and / or nickel coated surface;

Outlets, especially those made of brass, stainless steel, plastic and / or rubber.

The glass-like composite matrix provided according to the invention can be used in an advantageously simple manner in the form of a seal for the surfaces which come into contact with the water to be conducted, so that the entry of undesired constituents, in particular by diffusion, can be suppressed or completely prevented in the water to be conducted. In the context of this invention, metal atoms and ions are equally considered to be undesirable metals in water.

Compliance with drinking water concentration limits for undesired components is made particularly easy by the coating, which acts as a diffusion barrier. A conventional intensive surface cleaning can be omitted. In addition, such a coating is simple and inexpensive to produce. The matrix used as a coating is also good to very good resistant to coloring substances, such as coffee, red wine, ink, as well as acids and bases. The coated body can be used in a wide variety of areas, since the matrix is weather-resistant and has a high resistance to climate and UV, in particular a good resistance to temperature changes. The glass-like composite matrix can in particular be produced and constructed in accordance with the principles of chemical nanotechnology.

According to the invention, a glass-like composite matrix is understood to mean an inorganic, organic or inorganic-organic matrix which has a glass-like hardness and / or structure. The matrix therefore forms a network with which a covering and / or a coating of a body can be produced. By varying the matrix composition, the diffusion tightness of the matrix with respect to selected undesired components can be adjusted.

Composite matrices which are nanocomposite materials or contain nanocomposite material are particularly preferred. Matrices which contain hybrid coating materials (hybrid polymers) or generally organic coating materials, for example polymeric coating materials, are particularly preferred.

A particularly high wear, water and chemical resistance of the water-conducting body, in particular a fitting, can be achieved by a dense matrix serving as a coating, which is preferably highly inorganic. The diffusion of undesirable substances into the water side an appropriately coated body can be severely restricted or completely prevented. In particular, the matrix is resistant to salt water and chlorinated tap water. It also enables a very firm connection to the body to be coated.

The glass-like composite matrix is expediently firmly bound to the substrate of the water-conducting body. This supports the wear resistance of the coated body, in particular against steel wool and sand or abrasives, as are often used for cleaning fittings. The matrices according to the invention can be used to provide customary surfaces of water-conducting bodies, in particular steel such as, for example, stainless steel, copper and alloys, in particular brass and bronze, plastics, ceramics, rubber and painted and / or coated surfaces, in particular those which are provided with chromium, nickel and / or alloys of these metals are coated. It is also possible to provide surfaces made of wood or stone with the matrix, the surfaces optionally being painted and / or coated, for example with chromium, nickel and / or alloys of these metals. The composite matrix can, for example, be applied to a base coating of the water-conducting body.

For example, the matrix is preferably applied as a coating to the water-side surface of the body. In the case of water pipes, this is usually the inside. However, the matrix can also be attached to another surface of the body, for example on a surface which is on a side of the body remote from the water-side surface, e.g. a tube outside. In particular, the coating can be applied simultaneously on the water-side surface and on a further surface, preferably on all surfaces accessible from the outside. In this way, the advantageous properties of the coating according to the invention can benefit both the water to be conducted and the body as such.

The matrix can form an externally accessible coating of the water-conducting body, but it can also be wholly or partially be covered by one or more coatings. Its main effect, namely preventing undesired constituents from passing through the matrix, can as a rule also be exerted when it is covered by one or more coatings. However, the matrix particularly preferably forms at least partially or completely an outer coating of the water-conducting body, it being particularly preferred if the matrix forms a water-side outer coating or at least partially a water-side outer coating of a water-conducting body. In this way, the further advantageous properties of the matrix can be used particularly well. For example, the matrix can therefore be an outer coating, ie an uppermost coating, on the inside of a water-conducting pipe or a fitting.

The matrix can preferably be produced in a sol-gel process. This manufacturing process allows the properties of the glass-like matrix to be adjusted in a simple manner. In addition, the matrices produced in this way are insensitive to environmental influences, they are durable, hard, scratch-resistant and homogeneous. It is also particularly advantageous that the matrices are corrosion-resistant and that metals offer corrosion protection, in particular aluminum, magnesium and steel. By using the sol-gel process, a combination of organic and inorganic building blocks can be used to selectively set materials or surfaces with defined properties. In particular, the matrix can also be provided with anti-bacterial properties or with anti-graffiti properties.

The matrices or their gel-like precursors can be applied to the body to be coated without great effort and, depending on the type of matrix and the material of the body to be coated, there can be radiation-hardened and / or thermally hardened, for example fired or annealed. It is particularly preferred to thermally harden the matrix at 60 ° C. to 180 ° C. on the body to be coated. In particular in the case of radiation curing, for example using UV and / or IR emitters, curing can also take place at room temperature. The matrix can be produced in a controlled manner in a sol-gel process, a controlled growth and aggregation process of molecular units being a targeted and reproducible representation of multifunctional nanoparticulate systems allowed. The matrices can therefore be glassy-hard to polymer-soft and have adjustable surface properties that range from water-wetting to completely water-repellent. It is also possible to coat the body with a transparent or largely transparent matrix. In this way, the surface texture and / or grain remains visible even after coating.

Nanoparticles can also be introduced into the matrix. In addition to the advantages described above of a water-conducting body coated according to the invention, a nanoparticle-containing matrix also enables a very high abrasion resistance, electrical conductivity, catalytic activity and / or permanent protection against ultraviolet and / or infrared radiation to be achieved.

Inhibitors can also be incorporated into the matrix. These enable a further passivation of the matrix surface and thus the surface of the water-conducting body coated with the matrix. The

Inhibitors can in particular have a depot effect. In particular, corrosion inhibitors can be incorporated as part of the matrix.

They also improve the corrosion protection of metallic bodies, for example those that contain aluminum, magnesium and / or steel.

The matrix can be applied in a simple manner to the body to be coated, for example by spraying or roller application or by immersion in a liquid bath. Alternatively or in addition to

Inhibitors can also incorporate pigments into the matrix for easy coloring.

The glass-like composite matrix can expediently form a coating with a thickness of 1 nm or more, in particular from 10 nm to 50 nm. However, coatings with a thickness from 1 μm, preferably 10 μm to 50 μm, are particularly preferred. It has now been shown that such thin coatings are sufficient to significantly and permanently reduce the entry of undesirable components into the water to be conducted. However, a body whose coating is hydrophobic and / or oleophobic is particularly preferred. On the one hand, such coatings are easy to clean, since dirt and accompanying substances dissolved in the water hardly adhere to them. On the other hand, they cause a low surface energy of <24 mN / m ² and a contact angle of approx. 110 ° against water and approx. 60 ° against hexadecane. The coated bodies are easy to clean and have non-stick properties.

Surprisingly, it has been shown that these hydrophobic and / or oleophobic coatings, even in very small thicknesses, from 1 nm, significantly and permanently reduce the entry of undesired constituents into the water to be conducted, or completely prevent them. The advantages mentioned above, in particular durability, corrosion resistance, hardness, scratch resistance ^"" and homogeneity, and ease of handling are retained. It can therefore be sufficient if the coating has a thickness of 10 nm to 50 nm. The hydrophobic and / or oleophobic coatings now make it possible, for the first time, to seal the moving parts of a valve insert, where precise dimensions and spacing are required, with a coating.

According to the invention, a fitting for dispensing water is also specified, in particular a sanitary, kitchen and / or bathroom fitting, comprising a supply line, a discharge line and a water-conducting means for controllably connecting the supply and discharge lines, which is characterized in that the water-conducting means is a water-conducting body as described above. The inlet and / or outlet is preferably formed in one piece with the fitting. The water-conducting means can in particular be a water-conducting channel of a valve body, a shut-off means for closing such a channel, a valve insert, a valve cartridge and in particular a ceramic cartridge, a sealing element, the water outlet, the valve body itself or another which comes into contact with the water to be conducted Element of a tap or a tap. This fitting realizes the advantages described above associated with the use of the bodies coated according to the invention. The fitting is expediently designed in such a way that all water-conducting means on the water side have a surface which prevents the entry of undesired metals, in particular lead, zinc, nickel and copper ions, into the water to be conducted. On the one hand, these surfaces can be achieved in that the water-conducting means themselves do not contain any diffusible metals, so that no metals can escape from them into the water to be conducted. In particular, the water conducting means can consist of plastic, ceramic or the like. However, at least one water-conducting agent is a water-conducting body according to the invention as described above. This design of the fitting makes it possible to combine the advantages associated with the use of water-conducting bodies according to the invention with the advantages which can be achieved through the use of further materials and components in such a way that the water which can be dispensed from the fitting is permanently protected against the penetration of undesired constituents. In particular, it can be advantageous to produce seals and the like from plastic or an elastic material, while water-conducting channels and the water outlet of the fitting are water-conducting bodies according to the invention as described above.

It is particularly advantageous if the fitting is also coated with the glass-like matrix on its outer housing. Such fittings then also have the advantageous properties of the water-conducting body on their outside, in particular they are easy to clean and well protected against wear.

In order to be able to take full advantage of the advantages described above, it is also taught according to the invention to use a glass-like matrix as a water-side coating of a water-conducting body in order to prevent metals, in particular lead, nickel and copper ions, from escaping from the body. This includes the use of an inorganic glass-like matrix for producing a water-side coating of a water-conducting body. It is expedient if the water-conducting body is a water-conducting means of a fitting, in particular a sanitary, kitchen and / or bathroom fitting, connecting a supply line and a discharge line. The advantages that can be achieved with this use of the glass-like matrix are described above in the description of the water-conducting body itself.

It is particularly preferred to use a hydrophobic and / or oleophobic glass-like matrix for the purposes mentioned, in particular as a water-side coating of a water-conducting body.

According to a further aspect of the invention, the use of a silane for producing a glass-like matrix is proposed as a water-side coating of a water-conducting body, in particular a water-conducting means of a fitting that connects a supply line and a discharge line, in particular a sanitary, kitchen and / or bathroom fitting. The water-conducting bodies coated according to the invention can be produced particularly well with silanes. The silane is preferably an alkyl and aryl silane, amino functional silane, epoxy and glycol functional silane, mercapto functional silane, methacrylic functional silane, vinyl functional silane or silicic acid ester.

Particularly good glass-like matrices as a water-side coating of a water-conducting body can be produced using fluoroalkylsilane and / or polyfluoroalkylsilane. In particular, these silanes can be used to produce the hydrophobic and / or oleophobic coatings in which even a small coating thickness substantially reduces the entry of undesired constituents into the water to be conducted.

A method according to the invention for producing a water-side coating of a water-conducting body, in particular a water-conducting means of a fitting, in particular a sanitary, kitchen and / or bathroom fitting, connecting a supply line and a discharge line, comprises the steps: a) hydrolysis and condensation of one or more silanes, one or more alkoxides and one or more metal salts selected from the group consisting of Al, Ce, Ga, Ge, Sn, Ti, Zr, Hf, V, Nb and Ta metal salts with an acid , in particular an organic acid or a mineral acid,

b) applying the reaction product from step a) to the body to be coated, and

c) curing the reaction product from step a) applied in step b).

The reaction product from step a) can be applied by any method, in particular by dipping, spraying, brushing, spraying, spinning, polishing, floating and / or by electrostatic application. The hardening is expediently carried out by heating, customary brass fitting bodies preferably being heated at more than 100 ° C., preferably at 120 ° C. to 140 ° C., for 20 minutes or longer. The method enables the production and use of the coated water-conducting bodies described above and the associated advantages.

Such a method is preferred in which the silane or silanes are selected from the group consisting of alkyl and aryl silanes, amino functional silanes, epoxy and glycol functional silanes, mercapto functional silanes, methacrylic functional silanes, vinyl functional silanes and silicic acid esters.

However, a method is particularly preferred in which the silane (s) are selected from the group consisting of fluoroalkylsilanes and polyfluoroalkylsilanes. These silanes permit the production of the hydro- and / or oleophobic coatings and therefore make it possible to achieve the advantages associated with appropriately coated water-conducting bodies. The invention is described below with reference to the figures and examples. Show it:

Figure 1 shows a cross section through a coated mixer tap according to the invention.

2 shows a further cross section through a coated mixer tap according to the invention;

Fig. 3 shows a further cross section through a coated mixer tap according to the invention.

The fitting shown in cross section in FIG. 1, namely the mixer tap 1, has a valve insert 20 arranged in the mixer tap base body 10 with two water inlets 21, 22 for hot and cold water. The water inlets 21, 22 open into water-conducting channels 23, 24, which are provided in the form of recesses in the valve insert 20. The water-conducting channels 23, 24 are connected to a movable mixing cartridge 28 via spring-loaded, displaceable seals 25, 26. The mixing cartridge 28 makes it possible to set both the amount and the mixing ratio of the water supplied through the water inlets 21, 22. For this purpose, the mixing cartridge is connected to a control lever 27. Via a water outlet (not shown), the water mixed in the mixing cartridge 28 can exit from the mixing cartridge and the valve insert 20 into a water outlet 30 formed from the base body of the mixer tap 1. The water outlet 3O has an aerator 39 at its end facing away from the valve insert 20.

The base body 10 of the mixer tap 1 and the base body of the valve insert 20 are made of brass. The water inlets 21, 22, the water-conducting channels 23, 24, the mixing cartridge 28 and the water outlet 30 are each coated on their water-side surfaces with a glass-like matrix (not shown). The coating is hydrophobic and has a thickness of 20-30 nm. The other elements of the mixer tap 1 that come into contact with the water to be conducted are either made of plastic, are free of unwanted metals such as lead, nickel and copper, or have surfaces that strongly limit or prevent the entry of these metals into the water to be conducted.

In operation, water enters the valve insert 20 of the mixer tap 1 through the water inlets 21, 22 and is guided through the water-conducting channels 23, 24 to the mixer cartridge 28 and from there through the water outlet 30. On the way between the respective water inlet 21, 22 and the mixing cartridge 28 and from there through the water outlet 30 and the aerator 39, the water nowhere comes into contact with the brass material of the base body 10 of the mixer tap 1 or the valve insert 20. This prevents lead, copper and nickel from entering the respective base body into the water.

The mixer tap 1 'shown in FIG. 2, like the mixer tap 1 according to FIG. 1, has a valve insert 20' with corresponding water inlets 21 ', 22' and water-conducting channels 23 ', 24' for connection to a mixing cartridge 28 '. The water-conducting channels are also connected to the mixing cartridge 28 'via movable seals 25', 26 '. The mixing ratio and the amount of water to be mixed can be adjusted with the mixing cartridge 28 'via a control lever 27' connected to it. Water can emerge from the mixing cartridge 28 'into a water outlet 30' attached to the base body 10 of the mixer tap 1 '. The water outlet 30 'has an aerator 39' at its end facing away from the valve insert 20 '.

Also in the mixer tap 1 ', the water inlets 21', 22 ', the water-conducting channels 23', 24 ', the mixing cartridge 28' and the water outlet 30 'are each coated on the water side with a hydrophobic glass-like matrix of 20-30 nm in thickness. This prevents undesired metals, in particular lead, copper and nickel, from entering the base bodies of the mixer tap 1 ', the valve insert 20' and the water outlet 30 'into the water to be conducted. The remaining elements of the mixer 1 'coming into contact with the water to be conducted are either made of plastic and are free of undesirable metals such as lead, nickel and Copper, or have surfaces that strongly limit or exclude the entry of these metals into the water to be conducted. On the way from the water inlets 21 ', 22' through the mixer tap V and the water outlet 30 ', the water to be conducted nowhere comes into contact with materials from which lead, nickel or copper could penetrate into the water.

The mixer tap shown in Fig. 3 differs from that shown in Figs. 1 and 2 in the use of a ceramic cartridge 28 ". The ceramic cartridge has a ceramic base plate and an adjusting plate, each with passages for conducting hot and cold water The mixing ratio of hot and cold water and thus the temperature of the water discharged from the tap can be adjusted by rotating the base and adjusting disc against each other. With this mixer tap too, the elements that come into contact with the water to be conducted are either plastic and are free of unwanted metals such as lead, nickel and copper, or have surfaces which severely limit or exclude the entry of these metals into the water to be conducted, in particular they can be provided with a coating according to the invention.

Example 1: Production of an inorganic, glass-like matrix for a water-conducting body

40 g of tetraethoxysilane and 20 g of tetram ethylothosilicate are hydrolyzed with 10% by weight formic acid for 2 hours. The resulting gel-like reaction product is applied in an immersion bath to the surfaces of a mixer tap body and a valve insert that come into contact with water and cured at 130 ° C. for 40 minutes. The result is an inorganic, glass-like matrix with a thickness of 20-30 μm, which prevents metals or metal ions from passing through the coating from the respectively coated base body. Example 2: Production of a hydrophobic inorganic, glass-like matrix for a water-conducting body

20 g of dodecafluoroalkyltriethoxysilane are diluted with 20 g of water and mixed with 10 g of 10% strength by weight formic acid for 30 minutes with vigorous stirring. The resulting gel-like reaction product is applied in an immersion bath to the water-contacting surfaces of a mixer tap base and a valve insert and cured at 120 ° C. for 40 minutes. The result is an inorganic, glass-like matrix with a thickness of 20-30 nm, which prevents the passage of metals or metal ions from the coated base body through the coating and is also easy to clean.

Example 3: Production of an inorganic glass-like matrix for a water-conducting body

20 g of methyltriethyloxysilane and 10 g of tetraethylorthosilicate are diluted with a mixture of 15 g of ethanol and 6 g of isopropanol. A hydrolysis catalyst is provided consisting of 9 g demineralized water to which 0.08 g phosphoric acid (85%) is added. The hydrolysis catalyst is added dropwise to the solution of the silanes with stirring over a period of 5 minutes, the temperature increasing by about 10 ° C. After a subsequent stirring time of about 6 hours and a further standing time of 20 hours, the product is applied by dipping or flooding onto the surfaces of a mixer body and a valve insert that come into contact with water. Curing takes place at 103 ° C for 30 minutes. A coating with a thickness of 5-25 μm is created, which prevents metal ions from penetrating into the water from the base body.

Example 4: Production of an inorganic vitreous matrix for a water-conducting body 0.1 g of hydrochloric acid (37%) is added to a solution of 40 g of 3-glycidyloxytriethoxysilane, 10 g of tetraethylorthosilicate and 10 g of methyltrimethyoxysilane in 40 g of isopropanol. After a stirring time of 30 minutes, 0.6 g of N-aminoethyl-3-aminopropyltrimethoxysilane (DAMO, from Degussa-Huls) is added and the mixture is stirred for a further 30 minutes. The product is applied to the surfaces of a mixer body and a valve insert that come into contact with water by dipping or flooding. Curing takes place at 103 ° C for 30 minutes. A coating with a thickness of 5-25 μm is created, which prevents metal ions from penetrating into the water from the base body.

Claims

claims

1. Water-conducting body, characterized by a coating of a glass-like composite matrix to prevent the escape of metals, in particular lead, zinc, nickel and copper ions, from the body.

2. Body according to claim 1, characterized in that the matrix can be produced in a sol-gel process.

3. Body according to claim 2, characterized in that the coating has a thickness of 1 μm or more, preferably 10 μm to 50 μm.

4. Body according to claim 2, characterized in that the coating is hydrophobic and / or oleophobic.

5. Body according to claim 1 or 4, characterized in that the coating has a thickness of 1 nm or more, preferably 10 nm to 50 nm.

6. Faucet for dispensing water, in particular sanitary, kitchen and / or bathroom fittings, comprising a supply line integral with the fitting, a discharge line integral with the fitting and a water conduit for controllable connection of the supply and discharge lines, characterized in that the Supply line, the discharge line and / or the water-conducting agent is a water-conducting body according to one of claims 1 to 5.

7. Fitting according to claim 6, characterized in that all the water-conducting means on the water side have an entry of metals, in particular lead, zinc, nickel and copper ions, into the surface to be prevented from conducting water.

8. Fitting according to one of claims 6 to 7, characterized in that the matrix is also attached to the outer housing of the fitting.

9. Use of a glass-like composite matrix as a coating of a water-conducting body to prevent the escape of metals, in particular lead, zinc, nickel and copper ions from the body.

10. Use of a glass-like composite matrix according to Claim 9, characterized in that the water-conducting body is a water-conducting means of a fitting, in particular a sanitary, kitchen and / or bathroom fitting, connecting a supply line and a discharge line.

1 1. Use of a glass-like composite matrix according to one of claims 9 to 10, characterized in that the matrix is hydrophobic and / or oleophobic.

12. Use of a silane for the production of a glass-like composite matrix as a coating of a water-conducting body, in particular a water-conducting means of a fitting connecting a supply line and a discharge line, in particular a sanitary, kitchen and / or bathroom fitting.

13. Use of a silane according to claim 12, characterized in that the silane is an alkyl- and arylsilane, amino-functional silane, epoxy- and glycol-functional silane, mercapto-functional silane, methacrylic-functional silane, vinyl-functional silane or silicic acid ester.

14. Use of a silane according to claim 13, characterized in that the silane is a fluoroalkylsilane or polyfluoroalkylsilane.

15. A method for producing a water-side coating of a water-conducting body according to one of claims 1 to 5, in particular a water-conducting means of a fitting, in particular a sanitary, kitchen and / or bathroom fitting, connecting a supply line and a discharge line, comprising a) the hydrolysis and condensation one or more silanes, one or more alkoxides and one or more metal salts selected from the group consisting of Al, Ce, Ga, Ge, Sn, Ti, Zr, Hf, V, Nb and Ta metal salts with an acid, in particular an organic acid or a mineral acid, b) the application of the reaction product from step a) to the body to be coated, and c) the curing of the reaction product applied in step b) Step a).

16. The method according to claim 15, characterized in that the or the silanes are selected from the group consisting of alkyl and aryl silanes, amino functional silanes, epoxy and glycol functional silanes, mercapto functional silanes, methacrylic functional silanes, vinyl functional silanes and silicic acid esters.

17. The method according to claim 16, characterized in that the or the silanes are selected from the group consisting of fluoroalkylsilanes and polyfluoroalkylsilanes.