WO2015161933A1

WO2015161933A1 - Method for hydrophobizing and/or oleophobizing a material, and hydrophobized and/or oleophobized component

Info

Publication number: WO2015161933A1
Application number: PCT/EP2015/050093
Authority: WO
Inventors: Reiner Nico Behrendt
Original assignee: Volkswagen Ag
Priority date: 2013-12-17
Filing date: 2015-01-06
Publication date: 2015-10-29
Also published as: EP3083076B1; EP3083076A1; DE102013226215A1; CN105992654A

Abstract

The invention relates to methods for hydrophobizing and/or oleophobizing a material. The method involves the following steps: - charging a compressed gas (22) with a water repellent and/or oil repellent (21); - bringing the material (15) in contact with the compressed, charged gas (20); and - eliminating the gas (20) from the material (15). The invention further relates to a component of an electric machine, comprising or made of a material. According to the invention, a water repellent and/or an oil repellent can be detected down to a depth of at least 1mm in the material in a an area located near the surface of the material.

Description

description

Process for the hydrophobization and / or oleophobization of a material and

hydrophobized and / or oleophobized component

The invention relates to a method for hydrophobing and / or oleophobization of a material and a component of an electric machine comprising or consisting of an oleophobated material.

Components are often made, at least in some areas, with polymers coated materials. These polymers are used, for example, as potting compounds for electrical machines, printed circuit boards or electrical assemblies, but also for bonding and, for example in the form of protective coatings, as a coating. Many material groups of the components involved often show signs of corrosion or swelling on contact with oily and / or aqueous solutions. An example of this is the so-called copper corrosion, which often starts when electrical and / or electronic components come into contact with media necessary for the functioning. In the field of bonding, however, in particular problems occur when moisture penetrates between the contact areas of polymer and component and there leads to corrosion, decomposition and swelling, which in turn can lead to destruction of the adhesive bond and the component. Particularly relevant are such problems in the field of electrical machines.

Electrical machines (electromechanical converters), such as electrical

Drive motors for motor vehicles, starters, generators or starter generators convert electrical energy into mechanical energy (motors) or mechanical energy into electrical energy (generators). This electromechanical transformation is based on electromagnetic induction. Such electrical machines include a fixed stator (stator), the stator of a common type (laminated core) with

corresponding wire windings and arranged thereon switching rings, and a movable component, which is formed in the most common type as a rotor (rotor), which is rotatably mounted in or around the annular stator and has a plurality of permanent magnets. In this case, due to the moving magnetic field of the rotor, a current flow in the stator winding is generated (generator) or due to the through Magnetic field generated by the stator causes the mechanical movement / rotation of the rotor (motor). Reverse construction types in which the rotor comprises a winding and the stator comprises magnets are also known.

Parts of the winding and the switching ring having stator and / or rotor are embedded for the purpose of their electrical insulation and their mechanical protection and protection against chemical influences in a potting compound. The casting compound is used in particular for embedding the switching ring (also referred to as a switching ring or contact bridge), which electrically interconnects the individual windings.

Typically, potting compounds are based on a silicone rubber. To increase their thermal conductivity, these silicone elastomers often contain an addition of high filler fractions, for example in the form of quartz particles. Such materials meet most of the technical requirements for potting compounds, in particular they have a very low electrical conductivity, high temperature and thermal shock resistance, high thermal conductivity, high oxidation stability, good substrate adhesion and ease of curing and high processing tolerance. However, the problem is the high affinity of the silicones for hydrocarbons. So they show the tendency to include engine and transmission oils and swell. The swelling affects the mechanical properties. For example, the strength and hardness of the material decreases, the temperature resistance decreases, and detachment and possibly embrittlement of the potting compound can be the result. In particular, in oil-cooled electric motors, the design-related contact with gear oils in contact, is thus the reduction or

Prevention of oil absorption and swelling of the silicone material desirable.

In the area of magnet bonding to the rotor or stator, penetrating media can also cause problems. As an adhesive for the magnets in particular silicone resin systems are used, which are sometimes filled with glass beads, which has the function of

Have spacers and thus ultimately allow the adjustment of the thickness of the adhesive film. The Magnetverklebung should basically the same technical

Requirements such as the potting compound (see above) and in addition a good

Adhesive effect for the magnets or laminated cores have. In particular, the silicone resin system used should also not be impaired by the penetration of moisture or oils and the adhesive strength should be reduced.

DE 31 33 734 C2 describes an electrical insulation for a winding head of a stator or rotor of an electrical machine, which simultaneously protects against moisture. The coating contains a silicone rubber as a base material which contains rod-shaped copolymers based on styrene-butyl acrylate instead of a mineral filler.

In addition, the water-repellent effect of fluorine-containing compounds from many technical fields is known. For example, textiles are coated with PFTE or fluorocarbon chains are covalently attached to the fibers to produce hydrophobic and, at the same time, oleophobic surfaces. It is also known from the textile industry to apply hydrophobic coatings based on silicones and fluorocarbons on the textiles. In synthetic fibers of polyolefins or polyesters is also the

Gasphasenfluorierung applied, which is a complex combination of plasma treatment, air supply, grafting of fluorocarbon monomers and then another

Plasma treatment in CF ₄ atmosphere requires (US 201 1045200A1).

US 5,416,373 describes a winding of a stator or rotor of an electrical machine, in which the winding is coated with an electrically insulating film or with a Glimmmerband. In the exposed winding head area, a fluorine-containing coating is additionally applied in order to protect the winding against moisture.

The object of the invention is to provide a process for the hydrophobization and / or oleophobization of components which solves or at least alleviates the problems of the prior art. In particular, the durability and durability of the hydrophobization and / or oleophobization should be significantly increased.

This object is achieved by a method having the features of claim 1 and by a component of an electric machine, comprising a material which has been oleophobized with the method. Thus, a first aspect of the invention relates to a process for the hydrophobization and / or oleophobization of a material comprising

a. the loading of a compressed gas with a hydrophobing and / or

oil repellents,

b. Contacting the material with the compressed and laden gas and c. Removing the gas from the material

The process sequence may, if necessary, be the same or different

Hydrophobing and / or Oleophobierungsmittel be repeated. In conventional application of hydrophobing and / or oleophobizing agents by brushing, Spraying or dipping on the materials to be isolated only a protective layer in the nanometer range can be applied. If the surface is damaged or has these foreign phases, for example due to filler particles, oil can penetrate into these places, damage the material and further damage the insulation layer

ahead. The inventive method, however, achieves a depth impregnation of the treated material. This can be achieved by using a compressed gas as a carrier for a hydrophobing and / or oleophobizing agent. The loaded gas penetrates deep into the materials to be isolated together with the hydrophobing and / or Oleophobierungsmittels. In a subsequent removal of the gas, the hydrophobizing and / or Oleophobierungsmittel remains in and on the material. Accordingly, both a depth impregnation of a few nanometers and a surface impregnation of a material can be achieved by the method according to the invention. By using a compressed gas as a carrier, a wide range of soluble hydrophobing and / or Oleophobierungsmitteln can be used. It is completely irrelevant whether they are manageable even in the gaseous state. In addition, for the actual solvent, namely the compressed gas, no toxic or combustible solvent must be used, which is advantageous from an ecological as well as economic point of view compared to previous methods, especially if the solvent is reused, ie recycled.

The loading of the compressed gas generally takes place under pressure and can be carried out in a pressure chamber, for example an autoclave. Under loading in the present invention, a process is understood in which it by sorption to a

Enrichment of a substance, in particular the hydrophobing and / or

Oleophobierungsmittels, comes in a phase of the material or at a phase boundary. The substance to be loaded is a compressed gas, which is compressed due to an increased pressure compared to normal atmospheric pressure. The molar amount of 1 mol of compressed gas occupies a volume smaller than 22.4 l over the uncompressed ideal gas state under standard conditions. In the present invention, a hydrophobizing and / or oleophobizing agent is to be understood as meaning an agent which has the oleophobic, ie the oil-repellent character of a substance, in particular its content

Surface increased, so even has a higher oleophobicity than the material. The oleophobicity can be measured, for example, by (in particular static) measurement of the contact angle of a drop of oil on a flat surface of the material, with the contact angle correspondingly increasing with increasing oleophobicity. For water repellents and Hydrophobicity is analogous, whereby the water-repellent character is measured using a drop of water.

For the purposes of the invention, hydrophobizing and / or oleophobizing agents also and preferably include those which also have a hydrophobicizing effect via their oleophobic properties.

The hydrophobing and / or Oleophobieren a material according to the invention by contacting the material with the loaded gas. These materials are part of a component. Components are to be understood as materials which are processed in production processes and enter or represent the end products. This includes both semi-finished products, such as individual components, semi-finished products, such as stators and rotors in a manufacturing stage, but also finished products, such as e-machines. Furthermore, both components of metals and non-metals as well as organic and inorganic

Includes materials and their composites.

The contacting of the material with the loaded gas can also in a

Pressure chamber happen, which is conveniently adjacent to the pressure chamber in which the compressed gas was loaded with the hydrophobing and / or Oleophobierungsmittel. The opening of a lock would then cause the laden gas in the chamber in which the component is located to spread and fill. It is preferred that there is no decompression of the gas, but the gas is still compressed, so that the compressed gas saturates the surface and the near-surface region of the material. After a predetermined residence time, the gas can be separated from the material and removed from the chamber. This results in a separation between gas and hydrophobing and / or Oleophobierungsmittel. The hydrophobing and / or Oleophobierungsmittel remains on and / or in the material. The gas, on the other hand, can be returned to the process and reused. The material may be subject to subsequent treatments, e.g. a temperature step for reacting the reactive hydrophobing and / or Oleophobierungsmittels with the material to be subjected.

In a preferred embodiment of the invention, the component is one or more parts of an electric machine. Electrical machines, in particular rotors, stators, coils, their slot insulation, crimp connections, high-voltage and coil connections and shift rings are frequently exposed to engine and / or transmission oils. They persist, however often of materials such as copper, tin and other metals, which tend under the influence of such oils to corrosion and thus destruction. Thus, in particular these components are to be protected by a hydrophobing and / or oleophobization whose durability is in a meaningful relationship to the useful life, such as running time of the electric machine or the parts of an electric machine.

For the purpose of electrical insulation and / or encapsulation, components, at least in some areas, have a surface comprising a polymer. In a preferred embodiment of the invention, it is in the hydrophobic and / or oleophobierendem

Material around a polymer. Polymers are chemical compounds, in particular hydrocarbon compounds, from chains or branched molecules, which in turn consist of identical or similar units, the so-called repeating units.

Particularly preferred for the isolation of components are silicones. These may advantageously be suitable both for sealing and for bonding. The frequent use of silicone, such as potting compound in electric machines, stems in particular from the combination of high elasticity with low electrical conductivity, high thermal shock resistance, high thermal conductivity and high oxidation stability at the same time good underground adhesion ago. Such properties are found especially in silicones and epoxy resins, especially toughened epoxy resins.

Relative to the process according to the invention, polymers, in particular silicones, advantageously show a high permeability to the compressed gas. Thus, will

ensures that the loaded gas when contacting the component not only wets the surface of the polymer, but rather penetrates the polymer. Preferably, the loaded compressed gas also penetrates into the near-surface region of the polymeric material. Thus, even in the case of damage to the polymer, hydrophobization and / or oleophobization of the component in this area is ensured.

Preferably, the compressed gas is present as a supercritical fluid. A substance is then present as a supercritical fluid when pressure and temperature are above the critical point of the substance. The substance is then in a state in which the differences between liquid and gaseous cease to exist. Supercritical fluids therefore have significantly different properties than gases or liquids. For the most part, the diffusibility is similar to that of the gas, with the dissolving power closer to that of the liquid. The

Solvent properties in turn depend strongly on the density, which can be influenced in a relatively wide range. Higher density increases the solubility of most Substances. Supercritical fluids are extremely agile substances thanks to their high diffusibility.

This allows them to penetrate into other substances. If the compressed gas used in the process according to the invention is compressed in such a way that it is present as a supercritical fluid, it not only has a high degree of diffusibility, which makes it capable of producing the material

or to penetrate the polymer. Rather, the solvent power of the gas, in particular with respect to hydrophobizing and / or Oleophobierungsmittel, compared to the gaseous state is greatly increased. When the compressed gas present as a supercritical fluid is loaded with the hydrophobizing and / or oleophobizing agent, a very high concentration of hydrophobing and / or oleophobizing agent can be achieved. If the loaded fluid then comes into contact with the material, the surface of the material or the near-surface region within the material can be in a relatively short time with the hydrophobing and / or. Oleophobating be saturated. Thus, the use of a supercritical fluid as a carrier to a particularly uniform, seamless and / or deep water repellency or

Oleophobierung lead the material.

Most preferably, the gas, especially the supercritical fluid, is carbon dioxide. Carbon dioxide is a gaseous non-toxic substance at room temperature. The weak polarity, especially in the supercritical state, makes it an ideal solvent for most water repellents and oil repellents. The critical point of carbon dioxide is 31 ° C and 73.8 bar. Therefore, carbon dioxide is in

Production operations with moderate effort easy to handle and thus provides for the process according to the invention a good carrier. Also preferred as a carrier is oxygen, in particular critical oxygen. However, the location of the critical point (50.4 bar and -1 18.4 ° C) makes handling in production more difficult. In addition, the solution behavior in the case of oxygen is limited to non-polar solvents and thus does not cover the entire range of the preferred hydrophobizing and / or oleophobizing agents in materials science.

In a further embodiment of the invention, it is preferred that the hydrophobizing and / or oleophobizing agent comprises fluorocarbon compounds. Fluorocarbon compounds are partially or perfluorinated hydrocarbon compounds. Preferably, the fluorocarbon compound is a fluoroalkylsiloxane. These are trifunctional organic compounds, more specifically by fluoroalkyl groups and optionally

Aminoalkyl groups functionalized oligosiloxanes. The particular advantage over other fluorocarbon compounds is that in addition to the hydrophobic and oleophobic ones Characteristics of the compound to form Si-O bonds and subsequent cross-linking to chemical reactions with the surface of the material, in particular a polymer, may occur, whereby a particularly good connection between surface and hydrophobizing or Oleophobierungsmittel forms. The use of tridecafluorooctyltrietoxysiloxane as fluoroalkylsiloxane has proven particularly advantageous. This compound is particularly well suited for production, as it shows on the one hand very good adhesion, hydrophobing and Oleophobierungseigenschaften and also is non-toxic and therefore processable with little effort.

Alternatively, the fluorocarbon compounds have polar and / or ionic functional groups. These increase the oleophobic character of the fluorocarbon compounds. The fluorocarbon compound is then preferably a fluorosurfactant, in particular an ionic fluorosurfactant. On the one hand, fluorosurfactants comprise short to medium-length partially or perfluorinated carbon chains which have a hydrophobic character. On the other hand, fluorosurfactants have a polar, in particular an ionic, group in preferably terminal position, which gives the compound the desired oleophobic character. Preferred chain lengths of the hydrophobic partially or perfluorinated carbon chain are in the range of 2 to 40 carbon atoms, in particular from 4 to 30

Carbon atoms, preferably from 5 to 15 carbon atoms.

According to a preferred embodiment of the invention, the hydrophobing or

Oleophobieren, so the contacting of the material with the compressed gas over a period of one minute to 10 hours instead. Within this period, a balance of the concentration of the gas within the material and outside of the material is established and thus to an equilibrium concentration of the gas

Hydrophobizing or Oleophobierungsmittels inside and outside the material. This equilibrium concentration of hydrophobizing or Oleophobierungsmittel simultaneously represents the maximum concentration of the hydrophobing or

In order to almost saturate the surface of the material or the gas loaded within the material with hydrophobizing or oleophobizing agent, periods of from 1 to 7 hours, in particular from 2 to 3 hours, are particularly preferred , The saturation curve typically shows a hyperbolic pattern. In order to achieve the shortest possible production time with the greatest possible saturation, exposure times of two to three hours turned out to be advantageous. The concentration of hydrophobing and / or Oleophobierungsmittel on the surface and within the material is proportional to the concentration of the hydrophobizing or Oleophobierungsmittels within the carrier, ie the gas or the supercritical fluid. The concentration of the hydrophobizing or Oleophobierungsmittels within the carrier in turn depends on the solvent power of the carrier. The solvent properties of the carrier in turn, in particular in the supercritical state, are proportional to the density of the carrier. Since the carrier should preferably be present at least almost saturated with hydrophobizing or Oleophobierungsmittel, the hydrophobicizing or oleophobizing preferably takes place under a pressure of at least 55 bar and / or at a temperature of at least 25 ° C.

According to a preferred embodiment of the invention, the removal of the gas is triggered by pressure reduction. After saturation of the material with the loaded gas is preferably carried out first, a pressure reduction to ambient pressure, in particular, the largest possible pressure gradient is realized. Preference is thus given to a sudden

Relax. By the spontaneous relaxation of the gas, a separation of the gas from the hydrophobizing or Oleophobierungsmittel. Through the transition from

Supercritical in the gaseous state, the carrier escapes from the material. The hydrophobizing or Oleophobierungsmittel, however, remains on the material or in the material. The gaseous present, preferably of

Hydrophobizing or oleophobizing liberated carrier can by suitable apparatus in the first chamber, in the formerly the loading of the carrier with

Hydrophobizing or Oleophobierungsmittel took place, be returned and thus recycled. Compared to conventional hydrophobization or Oleophobierungsverfahren the described method can be carried out particularly ecologically and economically.

A further aspect of the present invention relates to a component of an electric machine comprising a material or consisting of a material, wherein a hydrophobing and / or oleophobizing agent in a near-surface region of the material to a depth of at least 1 mm, in particular at least 2mm, preferably at least 2, 5 mm, in which material is detectable. In this case, the hydro- and / or oleophobizing agent in the said depths preferably has a mass fraction of at least 1 wt .-% based on the total mass of material and hydro- or Oleophobierungsmittel. The component according to the invention is hydro-functional and / or oleophobic, for example by the method described above. In conventional application of hydrophobing and / or Oleophobierungsmittel, such as by brushing, spraying or dipping, Only a superficial protective layer in the nanometer range can be achieved on the component. If the surface of the material is damaged or has foreign phases, the material and thus the component may be destroyed by oil-induced corrosion. On the other hand, it finds a near-surface area of the material

Tiefenoleophobierung instead, it can be ensured despite superficial damage to the material, a hydrophobing and / or oleophobization of the material. A

Hydrophobization and / or Oleophobierung in the near-surface area within the

Material thus increases the durability of the hydrophobing and / or Oleophobierung, especially if the component is exposed as a result of use harmful external influences. In addition, the hydrophobing and / or oleophobization is not bound to the durability of any intermediate layers, such as polymers.

The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

The invention is described below in embodiments with reference to the associated

Drawings explained. It shows:

Figure 1 is a schematic representation of the method according to the invention.

Below, the invention will be explained in more detail with reference to the schematic representation shown in Figure 1 and a concrete embodiment. The procedure is in

preferably carried out in two interconnected chambers 30 and 35 and is basically articulated in four process steps. FIG. 1 shows the invention

Process for the hydrophobization and / or oleophobization of a material 15 in four steps.

At the beginning, as shown in Figure 1 a, in a first chamber 30, a compressed gas 22, here supercritical carbon dioxide with a hydrophobing and / or

Oleophobing agent 21 loaded. The chamber 30 should be a pressure chamber adapted to the necessary pressure and temperature conditions to produce a supercritical gas.

The hydrophobing and / or Oleophobierungsmittel 21 preferably comprises a

Fluorocarbon compound, which in the present example has polar and / or ionic groups. Preferably in the fluorocarbon compound is a fluoroalkyl siloxane as from Evonik under the trademarks Dynasylan ^® F8261, Dynasylan ^® F8263, Dynasylan ^® F8815, Dynasylan ^® Sivo and Dynasylan ^® Sivo CLEAR and Dynasylan ^® Sivo Clear EC is sold. Alternatively, the use of an ionic fluorine surfactant as

Hydrophobing and / or Oleophobierungsmittel preferred 21, in particular a partially fluorinated C2 to C40-Phosphorsäurealkylester. Preferably used as such a representative is a reaction product of 1H, 1H, 2H, 2H, perfluoro-1-octanol and phosphorus pentoxide or a salt of this product, especially an ammonium salt. This preferably contains an acrylate-based binder and / or wetting agent. A suitable product is available under the trade designation Capstone ^® FS-63 (Fa. DuPont). Alternatively, the products Capstone ^® FS-81, FS Capstone 22, Capstone FS 61 FS 63 Capstone, Capstone FS 81 FS Capstone 3100 or Zonyl ^® FSP can (all from DuPont) may be used.

If the compressed gas 22 saturated with hydrophobing and / or Oleophobierungsmittel 21, the now loaded gas 20 is not shown here

Line connection in a second chamber 35 introduced (Figure 1 b). Preferably, the conditions within the second chamber 35 after the inlet of the laden gas 22 are similar to those in the first chamber 30. In the second chamber 35 is on arrival of the loaded gas 20 already has a component 10, which is a too hydro- and / or

oleophobic material 15 includes. Alternatively, the component 10 may also after the

Introducing the gas via a lock, not shown, are introduced into the chamber 35. The component 10 is, for example, a stator of a

Electric machine.

Component 10 has a material 15 on its surface. The material 15 may be a layer of a polymer, here a potting compound. It is irrelevant whether the layer is applied over the entire surface or only in a certain area of the surface.

The material 15 is in particular a silicone, preferably a methylpolysiloxane rubber, for example a vinylmethylpolysiloxane rubber (VMQ) or a phenylvinylmethylpolysiloxane rubber (PVMQ). For example, under the brand RAKU-SIL ^® 10-S 9.13 (Fa. Rampf Giessharze GmbH & Co. KG) distributed silicone elastomer can be used here. It is preferred to use addition-crosslinking silicone rubbers. The polymer is dependent on the completely einzugießenden component, typically applied in a thickness of several millimeters, for example 5 mm.

The loaded gas 20 is evenly distributed in the chamber 35 due to normal physical processes and the given degrees of freedom. It also deposits on it the surface of the component 10, in particular on the material / polymer 15 from (Figure 1 c). Due to the high degree of diffusibility of compressed gases, the laden gas 20 penetrates into the region of the material 15 near the surface. Also favored is the inclusion of penetration of the laden gas 20 through the conditions prevailing in the interior of the chamber 35 conditions, such as pressure and temperature. Both parameters are increased in relation to the normal conditions (25 ° C and 1 bar). Again, since both parameters are directly related to the diffusivity of the loaded gas 20 and thus to the depth of penetration, the conditions within the chamber 35 favor laden gas 20 as high as possible in the material 15. In addition to the highest possible penetration depth, it is advantageous that the loaded gas 20 as evenly as possible on the surface of the

Material 15 is concentrated. These parameters are preferably influenced by the exposure time, ie the common residence time of loaded gas 20 and material 15 in the chamber 35 under elevated pressure. Ideal exposure times are between one minute and 10 hours, but preferably between 1 and 7 hours. Within this time, a saturation of the material 15 with loaded gas 20 occurs.

Subsequently, the compressed gas 20 is separated from the material 15 (Figure 1 d). This may preferably be done by pressure reduction, wherein the compressed gas 20 is expanded and passes into a gaseous state. It loses his

excellent support properties and the hydrophobing and / or

Oleophobicating agent 21 is no longer present dissolved in the gas 22. While the gas 22 escapes from the material 15 and is conducted out of the chamber 35 via a way, not shown, the more inert hydrophobing and / or oleophobizing agent 21 remains in and on the material 15. Excess water repellent and / or oil repellent 21, ie such which has not penetrated into the material 15 or not

condensed on the surface is also passed out of the chamber 35.

Both the gas 22, as well as excess hydrophobing and / or

Oleophobing agents 21 are not contaminated in the process according to the invention, so that they are introduced again into the first chamber 30, optionally concentrated and

can be reused. This recycling of the starting materials enables an economical and at the same time ecological hydrophobing and / or oleophobization of

Materials.

The individual steps will be explained again below in a concrete embodiment. In one possible embodiment, in a high pressure reactor (chamber 30)

Hydrophobing and / or Oleophobierungsmittel (21) in supercritical carbon dioxide (compressed gas 22) at a pressure of 75 bar and a temperature of 35 ° C brought into solution. When the carbon dioxide (compressed gas 22) now present as supercritical gas is saturated with hydrophobing and / or oleophobizing agent, the resulting loaded gas (20) is passed into a second chamber (35). In this second chamber previously a stator (component 10) of an electric machine was introduced. Here, the same conditions prevail in terms of pressure and temperature as in the first chamber. Because the loaded gas is in the supercritical state, it has particular transport and carrier properties relative to the hydrophobing and / or oleophobizing agent. It penetrates deep into the material 15, in particular in potting compound, impregnating resin and

Slot insulators of the stator and drags the hydrophobing and / or

Oleophobating agent with. After about two to three hours, the setting of the

Equilibrium and thus also reaches the equilibrium concentration of hydrophobing and / or Oleophobierungsmittel in and on the stator. Subsequently, the pressure in the second chamber is abruptly reduced by opening a valve in a third chamber, whereby the carbon dioxide passes from the supercritical state to the gaseous state. This has the consequence that the carbon dioxide abruptly its special carrier and

Transport properties loses and the carbon dioxide leaving the

Hydrophobizing and / or Oleophobierungsmittels from the hydrophobic or

escapes oleophoban components of the stator. The remaining outside of the stator hydrophobing and / or Oleophobierungsmittel and the expanded carbon dioxide are pumped back from the second and third chamber in the first chamber of the high pressure reactor and there transferred with the addition of further hydrophobing and / or Oleophobierungsmittel by pressure increase again in the supercritical state , At the same time, the hydrophobized and / or oleophobized stator is discharged from the second chamber and a new material to be hydrophobized or oleophobized is introduced into the chamber. The process can start anew.

Further experiments, which were carried out with carbon dioxide, showed that even at 50 bar compressed carbon dioxide at room temperature and a saturation period of 14 hours shows sufficient transport properties for the hydrophobing and / or Oleophobierungsmittel Dynasylan F8815, so that materials with hydrophobing and / or Oleophobierungsmittel The fracture surfaces of the treated silicon platelets were examined for fluorine with EDX in about 1 mm Depth could be a fluorine concentration of 3.98 wt .-% against 32.8 wt .-% detected on the surface. In classical diving only 0.36-0.95 wt .-% of fluorine in 1 mm depth were detectable. Even though the masses are not completely in favor of EDX due to the lack of hydrogen, the difference is clearly visible.

LIST OF REFERENCE NUMBERS

component

Material laden gas

Hydrophobizing and / or Oleophobierungsmittel compressed gas first chamber

second chamber

Claims

claims

1 . Process for the hydrophobization and / or oleophobization of a material, comprising: a. Loading a compressed gas (22) with a hydrophobing and / or

Oleophobicating agent (21),

b. Contacting the material (15) with the compressed and loaded gas (20) and

c. Removing the gas (22) from the material (15).

2. The method according to claim 1, characterized in that the material (15) is part of an electric machine.

3. The method according to claim 1 or 2, characterized in that the material (15) comprises or consists of a polymer.

4. The method according to claim 1 to 3, characterized in that the compressed gas (22) is present as a supercritical fluid.

5. The method according to any one of the preceding claims, characterized in that the gas (22) is carbon dioxide.

6. The method according to any one of the preceding claims, characterized in that the hydrophobing and / or Oleophobierungsmittel (21) comprises a fluorocarbon compound.

7. The method according to any one of the preceding claims, characterized in that the contacting of the material (15) takes place with the loaded gas over a period of 1 minute to 10 hours.

8. The method according to any one of the preceding claims, characterized in that the contacting of the material (15) takes place with the loaded gas under a pressure of at least 55 bar and / or at a temperature of at least 25 ° C.

9. The method according to any one of the preceding claims, characterized in that the removal of the gas (22) is triggered by pressure reduction.

10. A component (10) of an electric machine, comprising a material (15) or consisting of such, characterized in that a hydrophobing and / or Oleophobierungsmittel (21) in a near-surface region of the material (15) to a depth of at least 1 mm in the material (15) is detectable.